Anterior Cruciate Ligament

Lasers Med Sci.  2014 Apr 11. [Epub ahead of print]

Low-level laser therapy prevents degenerative morphological changes in an experimental model of anterior cruciate ligament transection in rats.

Bublitz C1, Medalha C, Oliveira P, Assis L, Milares LP, Fernandes KR, Tim CR, Vasilceac FA, Mattiello SM, Renno AC.
  • 1Department of Bioscience, Federal University of São Paulo, Av. Ana Costa, 95, Vila Mathias, Santos, SP, 11050-240, Brazil, carolinebublitz@yahoo.com.br.

Abstract

The aim of this study was to analyze the effects of low-level laser therapy (LLLT) on the prevention of cartilage damage after the anterior cruciate ligament transection (ACLT) in knees of rats. Thirty male rats (Wistar) were distributed into three groups (n?=?10 each): injured control group (CG); injured laser-treated group at 10 J/cm2 (L10), and injured laser-treated group at 50 J/cm2 (L50). Laser treatment started immediately after the surgery and it was performed for 15 sessions. An 808 nm laser, at 10 and 50 J/cm2, was used. To evaluate the effects of LLLT, the qualitative and semi-quantitative histological, morphometric, and immunohistochemistry analysis were performed. Initial signs of tissue degradation were observed in CG. Interestingly, laser-treated animals presented a better tissue organization, especially at the fluence of 10 J/cm2. Furthermore, laser phototherapy was able of modulating some of the aspects related to the degenerative process, such as the prevention of proteoglycans loss and the increase in cartilage area. However, LLLT was not able of modulating chondrocytes proliferation and the immunoexpression of markers related to inflammatory process (IL-1 and MMP-13). This study showed that 808 nm laser, at both fluences, prevented features related to the articular degenerative process in the knees of rats after ACLT.

Closed Bone Fracture

Photomed Laser Surg.  2014 Mar 20. [Epub ahead of print]

Therapeutic Outcomes of Low-Level Laser Therapy for Closed Bone Fracture in the Human Wrist and Hand.

Chang WD1, Wu JH, Wang HJ, Jiang JA.

11 Department of Sports Medicine, China Medical University , Taichung City, Taiwan (R.O.C) Abstract

Abstract Objective: The therapeutic outcomes of low-level laser therapy (LLLT) on closed bone fractures (CBFs) in the wrist and hand were investigated in this controlled study.

Background data: Animal research has confirmed that LLLT increases osteocyte quantity; however, little research has been conducted to determine the effect of LLLT on the treatment of human bone fractures.

Methods: In this study, the therapeutic outcomes of administering 830 nm LLLT to treat CBFs in the wrist or hand were examined. Fifty patients with CBFs in the wrist and hand, who had not received surgical treatment, were recruited and randomly assigned to two groups. The laser group underwent a treatment program in which 830 nm LLLT (average power 60 mW, peak power 8 W, 10 Hz, 600 sec, and 9.7 J/cm2 per fracture site) was administered five times per week for 2 weeks. Participants in a placebo group received sham laser treatment. The pain, functional disability, grip strength, and radiographic parameters of the participants were evaluated before and after treatment and at a 2 week follow-up.

Results: After treatment and at the follow-up, the laser group exhibited significant changes in all of the parameters compared with the baseline (p<0.05). The results of comparing the two groups after treatment and at the follow-up indicated significant between-group differences among all of the parameters (p<0.05).

Conclusions: LLLT can relieve pain and improve the healing process of CBFs in the human wrist and hand.

Amblyopia

Photomed Laser Surg.  2012 Mar;30(3):167-71. doi: 10.1089/pho.2011.3089. Epub 2012 Jan 11.

Lowlevel laser therapy improves visual acuity in adolescent and adult patients with amblyopia.

Ivandic BT1, Ivandic T.

Abstract

OBJECTIVE:

The purpose of this study was to examine the effects of lowlevel laser therapy (LLLT) on visual acuity in adolescent and adult patients with amblyopia.

BACKGROUND DATA:

Currently, amblyopia can be treated successfully only in children.

METHODS:

In this single-blinded, placebo-controlled study, 178 patients (mean age 46.8 years) with amblyopia caused by ametropia (110 eyes) or strabismus (121 eyes) were included. For LLLT, the area of the macula was irradiated through the conjunctiva from 1 cm distance for 30 sec with laser light (780 nm, 292 Hz, 1:1 duty cycle; average power 7.5 mW; spot area 3 mm(2)). The treatment was repeated on average 3.5 times, resulting in a mean total dose of 0.77 J/cm(2). No occlusion was applied, and no additional medication was administered. Best corrected distant visual acuity was determined using Snellen projection optotypes. In 12 patients (12 eyes), the multifocal visual evoked potential (M-VEP) was recorded. A control group of 20 patients (20 eyes) received mock treatment.

RESULTS:

Visual acuity improved in 90% of the eyes treated with LLLT (p<0.001), increasing by three or more lines in 56.2% and 53.6% of the eyes with amblyopia caused by ametropia and strabismus, respectively. The treatment effect was maintained for at least 6 months. The mean M-VEP amplitude increased by 1207 nV (p<0.001) and mean latency was reduced by 7 msec (p=0.14). No changes were noted in the control group.

CONCLUSIONS:

LLLT led to a significant improvement in visual acuity in adolescent and adult patients with amblyopia caused by ametropia or strabismus.

Low Level Laser + Stem Cells in Stroke in Rats

Evid Based Complement Alternat Med. 2013; 2013: 594906.
Published online 2013 December 2. doi:  10.1155/2013/594906
PMCID: PMC3865741

Low-Level Laser Stimulation on Adipose-Tissue-Derived Stem Cell Treatments for Focal Cerebral Ischemia in Rats

Chiung-Chyi Shen, 1 , 2 , 3 , 4 Yi-Chin Yang, 1 Ming-Tsang Chiao, 1 Shiuh-Chuan Chan, 5 and Bai-Shuan Liu 6 ,*
Author information  Article notes  Copyright and License information
Copyright © 2013 Chiung-Chyi Shen et al.
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This study investigated the effects of large-area irradiation from a low-level laser on the proliferation and differentiation of i-ADSCs in neuronal cells. MTT assays indicated no significant difference between the amount of cells with (LS+) and without (LS) laser treatment (P > 0.05). However, immunofluorescent staining and western blot analysis results indicated a significant increase in the neural stem-cell marker, nestin, following exposure to low-level laser irradiation (P < 0.05). Furthermore, stem cell implantation was applied to treat rats suffering from stroke. At 28 days posttreatment, the motor functions of the rats treated using i-ADSCs (LS+) did not differ greatly from those in the sham group and HE-stained brain tissue samples exhibited near-complete recovery with nearly no brain tissue damage. However, the motor functions of the rats treated using i-ADSCs (LS?) remained somewhat dysfunctional and tissue displayed necrotic scarring and voids. The western blot analysis also revealed significant expression of oligo-2 in the rats treated using i-ADSCs (LS+) as well as in the sham group (P < 0.05). The results demonstrated that low-level laser irradiation exerts a positive effect on the differentiation of i-ADSCs and can be employed to treat rats suffering from ischemic stroke to regain motor functions.

1. Introduction

Stroke has become a common disease and has been shown to be associated with the consumption of high amounts of oil and salt. These dietary habits cause blood vessels to narrow and become prone to occlusion, which can lead to stroke. Strokes can be broadly classified into 2 categories: ischemic and hemorrhagic strokes. Differing treatment methods are used according to stroke type and lesion location. Therefore, at stroke onset, computed tomography or magnetic resonance imaging is often used for diagnosis to provide physicians with a basis of treatment [1]. The treatment methods used for the 2 types of stroke are different. (1) Ischemic stroke is caused by thrombosis or blood clots in the brain vessels, which prevent blood flow into the brain tissues. Anticoagulants or antiplatelet medications must be administered to patients as soon as possible. (2) Hemorrhagic stroke is caused by the rupture or hemorrhaging of brain vessels caused by peripheral brain trauma (subarachnoid hemorrhage). The majority of cases of hemorrhagic stroke are caused by brain trauma (e.g., car and workplace accidents). Treating these patients often requires neurosurgical interventions [2]. Ischemic strokes constitute the majority of stroke cases. When patients suffer from ischemic stroke, the brain tissues necrotize gradually because of the lack of nutrients if anticoagulants or antiplatelet medications are not administered within 3 h of the stroke. After necrosis occurs, necrotic brain tissue cannot regenerate or recover its functions even if blood-vessel reperfusion occurs [3]. In recent years, stem cell treatment has become an innovative therapy for brain tissues that cannot regenerate.

Body fat extraction (e.g., abdomen, thigh, or buttock fat) has been used for body shaping procedures in the past, and the extracted fat was discarded as medical waste. Presently, medical experts have confirmed that adipose tissues contain large amounts of mesenchymal stem cells that exhibit in vitro proliferation and multiple differentiation ability, characteristics that facilitate the repair and regeneration of damaged tissues or organs [4]. In addition, adipose-derived stem cells (ADSCs) possess several characteristics: (1) they can be easily harvested in abundant quantities without invasiveness, (2) they can proliferate in in vitro cultures, and (3) they can be applied to a wide range of body tissue types because these cells migrate to lesion sites automatically to repair damage. Studies have shown that ADSCs can differentiate into many different cell types, such as adipose, bone, cartilage, smooth muscle, cardiac muscle, endothelial, blood, liver, and even neuronal cells [5]. Because of these characteristics, ADSCs will likely be one of the major sources of autologous stem cells in the future.

The effectiveness of laser therapy on biological bodies has been confirmed, and laser therapy has been successfully applied in new technological applications such as microsurgery. Lasers can be classified as high or low power, depending on the energy levels used. High-power lasers involve using high energy levels to provoke blood coagulation, stop bleeding, cut tissues, and even damage cells, whereas low-level lasers involve using electromagnetic or photochemical processes to achieve therapeutic effects [6]. A low-level laser is defined as a laser with extremely low power and energy too low to destroy the molecular bonding capacity (e.g., hydrogen bonds and van der Waals forces) of tissues. Therefore, low-level lasers do not cause molecular structural change, protein denaturation, or cell death. Irradiation from low-level lasers on tissue does not cause an obvious temperature increase at the treatment site (less than 0.1 to 0.5°C); thus, any physiological responses of the tissues are produced by the stimulation of the laser itself, and this mechanism is described by the theory of laser biostimulation [7]. In addition, by using an appropriate energy level, low-level lasers are primarily used to stimulate biological cells to induce or strengthen physiological responses for facilitating local blood circulation, regulating cell functions, promoting immunological functions, and facilitating cell metabolism and proliferation. Using lasers to generate these physiological changes enables treatment goals such as anti-inflammation and wound-healing promotion to be met [89]. Many studies have shown that low-level laser irradiation exerts beneficial biological effects on bone, neuronal, and skin healing [1012]. However, the type, wavelength, power, and energy level of lasers used in previous studies have varied, and various effects have been observed in different cells when differing levels of laser energy were applied. Previous studies have shown that using a low-level laser with an 820–830 nm wavelength can reduce neural damage, facilitate neuronal healing, and accelerate neural recovery after an osteotomy [1314]. Using a low-level laser with a 660 nm wavelength has been demonstrated to exert healing effects on musculoskeletal injuries and inflammation [15]. In addition, many studies have indicated that a low-level laser with a 660 nm wavelength can effectively promote neural regeneration and accelerate the reinnervation of muscle fibers to promote the recovery of motor functions [1618]. Recent evidence has suggested that protein aggregates such as ?-amyloid- (A?) associated neurotoxicity and dendrite atrophy might be a consequence of brain-derived neurotrophic-factor (BDNF) deficiency. Meng et al. observed that the upregulation of BDNF caused by using low-level laser therapy (LLLT) to activate the extracellular signal-regulated kinase (ERK)/cAMP response element-binding protein (CREB) pathway can ameliorate A?-induced neuron loss and dendritic atrophy, thus identifying a novel pathway through which LLLT protects against A?-induced neurotoxicity [19].

Currently, most low-level laser therapies in practical clinical applications emphasize treatment courses covering an extensive tissue area in a relatively short period. Multichannel-laser hair treatment, which is currently available for the physical treatment of alopecia, is one such example. Therefore, we used a large-area LLLT that differs from the irradiation methods previously reported in the literature (such as single-spot low-energy laser exposure or the scanning method) to increase the local area of exposure [18]. In this study, stem cells were extracted from adipose tissues, and neural-stem-cell- (NSC-) differentiating agents were used to culture these ADSCs to transform them into induced adipose-derived stem cells (i-ADSCs), which were used as experimental cells. First, we investigated the effects of large-area irradiation from a low-level laser on the proliferation and differentiation of i-ADSCs into neuronal cells. We then investigated whether i-ADSCs treated with laser irradiation and injected via an intravenous route could integrate and survive in various locations in rat brains. We investigated if this treatment could improve the neurological dysfunctions caused by ischemic brain damage in rats and if rats could produce BDNF, using this treatment. Studies using intravenous injection to transplant i-ADSC for the treatment of ischemic stroke with protocols similar to that used in the current study are rare. In this study, we further combined the biostimulation theory from large-area LLLT with transplantation of i-ADSCs to induce neural differentiation to investigate the effectiveness of ischemic stroke treatment. In a previous study [20], we established a transient ischemia-reperfusion stroke rodent model by using right-sided middle cerebral artery occlusion (MCAO) to simulate acute clinical insults. The effectiveness of the treatment was assessed by comparing HE-staining and western blot analysis, as well as the evaluation of motor skill indices by using the rotarod and grip-strength tests. Our protocol has the potential to be developed for application in the clinical treatment of patients with ischemic stroke.

2. Materials and Methods

2.1. Isolation and Culture of ADSCs

A flowchart illustrating the experimental design of the study is shown in Figure 1. Eight-week-old male Sprague-Dawley (SD) rats were used for isolating rat ADSCs. The ADSCs were harvested from the rats’ subcutaneous anterior abdominal wall. Inguinal fat pads were excised, washed sequentially in serial dilutions of betadine, and finely minced as tissues in phosphate-buffered saline (PBS). The tissues were digested with 0.3% of Type I collagenase (Sigma) at 37°C for 60 min. The digested tissue/cell suspension was filtered through a 100-mesh filter to remove the debris, and the filtrate was centrifuged at 1000 rpm for 10 min. The cellular pellet was resuspended using DMEM/F12 (10% FBS, 1% P/S) and then cultured for 24 h at 37°C in 5% CO2. Unattached cells and debris were then removed and the adherent cells were cultured using fresh medium. The cells were cultured to 80% confluency before being released with 0.05% trypsin and then subcultured.

Figure 1

A flowchart illustrating the experimental design. Detailed procedures are described in Section 2.

2.2. ADSC Neuronal Predifferentiation

In this study, i-ADSCs obtained from culturing ADSCs by adding NSC-differentiating agents were used as experimental cells. ADSCs within 3–5 passages were detached and induced using NSC media supplementation. ADSCs were resuspended in a serum-free DMEM/F12 medium supplemented with an N2 supplement (Sigma), 20 ng/mL of epidermal growth factor (Gibco, NY, USA), and fibroblast growth factor (Gibco, NY, USA).

2.3. Setup of a Low-Level Laser Application Method

The probe of the laser irradiation device was fixed vertically on a clean, open experimental bench. The distance between the probe and the cell culture dish was 30 cm. Laser irradiation was applied in a 25°C environment by using an AlGaInP-diode laser (Konftec Co., Taipei, Taiwan) with a wavelength of 660 nm at an output power of 50 mW and frequency of 50 Hz. In the control group, the cells that did not receive laser irradiation treatment, i-ADSCs (LS?) (n = 10), were compared with the experimental cells, i-ADSCs (LS+) (n = 10), which were subjected to a laser irradiation treatment of 10 min. The cells in the i-ADSCs (LS?) group were cultured for 7 days, whereas the cells in the i-ADSCs (LS+) group were treated using low-level lasers on the following day for 10 min and then cultured for 6 days. The cells receiving laser irradiation were collected at various times for analysis according to the purposes of the experimental protocols. After the completion of the cultures, an optical microscope was used for observing cell morphology.

2.4. MTT Assay

The principle of the MTT (3-[4,5-dimethylthiazol-2-y1]-2,4-diphenyltetrazolium bromide) assay is that the mitochondria of living cells can transform the yellow chemical substance MTT tetrazolium into the purple non-water-soluble substance MTT formazan through the effect of succinate dehydrogenase. DMSO can be used to dissolve the purple-colored products. No such response occurs in dead cells. An optical absorbance of 570 nm was measured using an enzyme immunoassay analyzer. A higher absorbance value indicates a larger amount of cells. In this study, ADSCs neuronal predifferentiation was first distributed in a 96-well plate with approximately 10000 cells per well. The cells in the i-ADSCs (LS?) group were then cultured in a 37°C environment and a 5% CO2 environment for 5 days and 7 days, respectively. The cells in the i-ADSCs (LS+) group were cultured in a 37°C environment and a 5% CO2 environment for 4 days and 6 days, respectively. After the completion of the cultures, the medium was removed by several rinses with PBS. An MTT solution of 100 ?L was added to each well of a 96-well plate in the dark (1 mL of MTT reagent was added to 9 mL of phenol-red-free, serum-free medium) and incubated in a 37°C, 5% CO2 environment for 2 h. The MTT solution was then removed and the cells were dissolved using DMSO. An optical absorbance of 570 nm was measured using an enzyme immunoassay analyzer to compare the values between the different groups.

2.5. Immunocytochemistry of i-ADSCs

After 7 days in culture, the subcultured neurospheres were washed using 0.1 M PBS 3 times and fixed with 4% paraformaldehyde for 1 h. Following the fixation, the cells were permeated with 0.1% of Triton X-100 for 10 min and then blocked with 5% nonfat milk for 30 min. The phenotypic expression of these neurospheres was examined by implementing immunocytochemical staining accompanied by antibodies against glial fibrillary acidic proteins (GFAPs) for astrocytes, mouse monoclonal antinestins for NSCs, and doublecortin (DCX), which has recently been used as a marker for neurogenesis. Briefly, the fixed cells were washed 3 times in cold PBS. After washing with PBS, the aforementioned primary antibodies were added and the slides were maintained at room temperature overnight. In the following day, the primary antibodies were removed by washing 3 times with PBS and the secondary antibodies were added before incubating the cells for 1 h. After washing off the secondary antibodies, the cells were incubated with tertiary antibodies tagged with peroxidase-antiperoxidase for 1 h. The tertiary antibodies were washed off using PBS. The cells were incubated with DAPI (Sigma, St. Louis, MO, USA) diluted with the cell culture medium for 10 min. Finally, the cells were mounted with 90% glycerol and examined using fluorescent microscopy (Olympus IX-71, Inc., Trenton, NJ, USA).

2.6. Animals and Induction of the MCAO Model

In a previous study [20], we established a transient ischemia-reperfusion stroke rodent model, using right-sided middle cerebral artery occlusion (MCAO) to simulate acute clinical insults. All of the experimental procedures were approved by the Institutional Animal Care and Use Committee of Taichung Veteran General Hospital, Taiwan. Thirty-two adult male SD rats were randomly allocated to 3 groups: the i-ADSCs (LS?) therapy group (n = 12), the i-ADSCs (LS+) therapy group (n = 12), and a sham group (n = 8). The rats in all 3 groups were euthanized on the 28th day after MCAO was performed. For MCAO procedures, anesthesia was induced using 4% isoflurane (Baxter, USA) and maintained using 2% isoflurane. A midline cervical incision was made to isolate the right bilateral common carotid artery. A 25 mm-long 3-0 nylon surgical thread was then inserted into the right carotid bifurcation. In this study, 2 rounds were used to provide a more complete blockage of blood flow in the artery. When the blunted distal end met resistance, the proximal end of the thread was tightened at the carotid bifurcation. The right common, internal, and external carotid arteries were carefully separated from the adjacent vagal nerve, and the distal portions of the external and common carotid arteries were ligated. A small incision was subsequently made at the proximal portion of the external carotid artery, and a 3-0 nylon monofilament suture was gently inserted (approximately 18 mm) into the internal carotid artery. After 60 min of MCAO, the nylon surgical thread was removed to allow complete reperfusion of the ischemic area. During ischemia, rectal temperature was monitored and maintained at approximately 37°C by using a heating pad and an overhead lamp. The anesthetized rats intravenously received i-ADSCs at a concentration of 2 × 107 mL?1 via their femoral veins. The rats in the sham group underwent the same surgical procedures except that the right-sided middle cerebral artery was not occluded.

2.7. Rotarod Test

An accelerating rotarod test was performed for each rat before and on the 7th, 14th, 21st, and 28th day after cerebral ischemia-reperfusion was induced. Before the ischemia-reperfusion experiment was conducted, the animals were subjected to 3 training sessions per day for 3 days on the accelerating rotarod to obtain stable duration on the rotarod spindle. The diameter of the rotarod spindle was 7 cm. The surface of the rotarod spindle was made of knurled Perspex to provide an adequate grip, which prevented animals from slipping off the spindle. The speed of the spindle was increased from 4 to 40 rpm over a period of 5 min and the duration that the animal stayed on the device was recorded. The rats that were capable of staying on the rotarod longer than 150 s after 3 training sessions were selected for the experiments. On the testing days, the animals were tested twice, and the longest durations on the rotarod were recorded.

2.8. Grip Strength Test

Each rat was supported in a horizontal position approximately parallel to a grip bar (Model DPS-5R: range 0–5 kgf, Japan). The researcher set the rat’s forepaws on the grip bar and pulled the animal horizontally away from the bar by the base of its tail until the rat released its grip. The pulling motion was smooth and continuous. The researcher supported the rat by the abdomen when the grip was released. The reading on the strain gauge remained constant at the point of maximal value, which was recorded as the measure of forepaw grip strength. The researcher supported the rat body by both the chest and the base of the tail at an angle of ?45° down the tail. The rat was facing away from the grip bar. The rat was encouraged to grasp the bar by moving its hind paw to the bar. When the rat grasped the bar with both hind paws, establishing a “full” grip, the upper body of the rat was lowered so that the rat was in a nearly horizontal position. The rat was pulled horizontally by the base of the tail until it released its grip and was supported as previously described. The reading on the strain gauge remained constant at the point of maximal value (force was measured in grams), which was recorded as the measurement of forepaw grip strength. Three values were obtained in succession, and the median value was used as the daily score. The data were expressed as the percentage of the baseline (preischemic) value.

2.9. Hematoxylin-Eosin Staining of the Cerebellum

The SD rats were anesthetized using 10% chloral hydrate (4 ?L/kg), administered intraperitoneally, and were euthanized on the 28th day after the MCAO operation and sham treatment. For each rat, the left cerebellum was rapidly removed and postfixed in formalin for 24 h. The postfixed tissues were embedded in paraffin wax and 6-?m-thick serial coronal sections were obtained and mounted on poly-L-lysine-coated glass slices. To assess the histological changes in the MCAO and sham groups, the paraffin-embedded left cerebellum sections were stained using hematoxylin-eosin (HE), according to standard protocol before the assay was performed.

2.10. Western Blot Analysis

Proteins were extracted from the rat brains by using a cold lysis buffer (10 mM of tetra sodium pyrophosphate, 20 mM of Hepes, 1% Triton X-100, 100 mM NaCl, 2 ?g/mL of aprotinin, 2 ?g/mL of leupeptin, and 100 ?g/mL of phenylmethylsulfonyl fluoride). The protein concentrations from tissue extracts or ADSC-conditioned medium were determined using the Bradford protein assay. Equal amounts of protein were placed in a 2× sample buffer (0.125 M Tris-HCl, pH 6.8, 2% glycerol, 0.2 mg/mL of bromophenol blue dye, 2% SDS, and 10% ?-mercaptoethanol) and electrophoresed through 10% SDS-polyacrylamide gel. The proteins were then transferred onto a nitrocellulose membrane by using electroblotting. The membranes were blocked for 1 h at room temperature in a Tris-buffered saline with Tween-20 (TBST) and 5% nonfat milk. The primary antibodies (1 : 1000) with appropriate dilutions were incubated for 1 h at room temperature in TBST and 5% nonfat milk. The blots were then washed and incubated with a peroxidase-conjugated secondary antibody (1 : 2000) for 1 h in TBST. The chemiluminescent substrate for the secondary antibody was developed using the ECL detection system (Amersham, UK). The blots were exposed to film for 3–5 min and then developed.

2.11. Statistical Analysis

The data were expressed as the mean value ± standard error of the mean. The statistical significance of the differences between the groups was determined using a one-way analysis of variance followed by Tukey’s test. An alpha level of less than 0.05 (P < 0.05) was considered statistically significant.

3. Results

3.1. Effects of the Low-Level Laser on Cell Morphology

The ADSCs were passaged 3–5 times after the initial plating of the primary culture. Rat ADSCs appeared to be a monolayer of large and flat cells (Figure 2(a)). Many cells in the i-ADSCs (LS?) and i-ADSCs (LS+) groups induced a neuronal phenotype and exhibited, among one another, bipolar and multipolar elongations of neuronally induced cell-forming networks. The results show that the stem cells in both i-ADSCs (LS?) and i-ADSCs (LS+) groups developed tentacles, indicating that ADSCs were facilitating the induction of differentiation into neuronal cells. Comparative optical micrographs revealed that some attached cells exhibited a spread-out shape with a spindle-like and fibroblastic phenotype in the i-ADSCs (LS?) group (Figure 2(b)). However, most of i-ADSCs-expressing neurites extended radially, connecting like bridges with those from adjacent cells in the i-ADSCs (LS+) group (Figure 2(c)).

Figure 2

The morphology of inductions of adipose-derived stem cell (i-ADSC) differentiation into neuronal cells after low-level laser irradiation. (a) Undifferentiated ADSCs; (b) i-ADSCs (LS?); (c) i-ADSCs (LS+). The arrow denotes the neuronal-like cells. 

3.2. Effects of the Low-Level Laser on Cell Proliferation and Differentiation

In this study, MTT assays were performed on Day 5 and Day 7 to evaluate the effects of large-area low-level laser irradiation on the facilitation of cell proliferation. After analyzing the optical absorbance values, the results showed that, on Day 5, cell activity was slightly higher in the i-ADSCs (LS+) group compared with that in the i-ADSCs (LS?) group. However, the difference was not statistically significant (P > 0.05). On Day 7, the cell amounts in both the i-ADSCs (LS+) and i-ADSCs (LS?) groups were larger than the amounts on Day 5. However, the cell proliferation rates were similar on Day 5 without major differences (P > 0.05) (Figure 3).

Figure 3

The cell activity of inductions of adipose-derived stem cell (i-ADSC) differentiation into neuronal cells in both the i-ADSCs (LS?) and i-ADSCs (LS+) groups on Days 5 and 7 after culture.

In this study, immunofluorescent staining and western blots were used to evaluate the effects of large-area low-level laser irradiation on the facilitation of cell differentiation. Immunofluorescent staining was performed for the NSC marker, nestin, glial cell marker, GFAP antibody, and neuronal precursor-cell-marker protein, DCX. After the staining was completed, fluorescent microscopy was used to observe the amount of fluorescence expression of each antibody. The results showed that the fluorescence expression of the nestin was higher in the cells in the i-ADSCs (LS+) group than that in the cells in the i-ADSCs (LS?) group. These results indicated that ADSC differentiation into neuronal cells was facilitated after large-area low-level laser irradiation (Figure 4(a)). For GFAP, no difference was observed in the amount of fluorescence expression of GFAP between the i-ADSCs (LS?) and i-ADSCs (LS+) groups (Figure 4(b)). Furthermore, for DCX, no difference was observed between the 2 groups because the cells in both groups still exhibited stem cell morphology (Figure 4(c)).

Figure 4

The immunofluorescent staining for (a) nestin; (b) GFAP; and (c) DCX of inductions of adipose-derived stem cell (i-ADSC) differentiation into neuronal cells in both the i-ADSCs (LS?) (left) and i-ADSCs (LS+) (right) groups. The scale bar represents 

Western blot is used to quantify the expression of marker proteins. Therefore, western blot analysis was used to compare the amount of nestin expression between the i-ADSCs (LS?) and i-ADSCs (LS+) groups in this study. The results showed that cells in the i-ADSCs (LS+) group exhibited a substantially higher nestin expression compared with the cells in the i-ADSCs (LS?) group (P < 0.05) (Figure 5). Regarding the results of GFAP and DCX, no difference was observed in the fluorescence expressions of the i-ADSCs (LS?) and i-ADSCs (LS+) groups. Therefore, western blot analyses were not shown for GFAP and DCX. This result is consistent with the findings obtained using immunofluorescent staining.

Figure 5

The cell growth of inductions of adipose-derived stem cell (i-ADSC) differentiation into neuronal cells with or without laser irradiation. (a) The amount of nestin expression. (b) The figure showing the quantification. GAPDH served as the internal reference. 

3.3. Evaluation of Behavior Recovery after Stroke in the Animals

In this study, treadmill and forepaw-grip tests were used to evaluate motor function recovery after stem-cell transplantation treatment in rats with ischemic stroke. The treadmill test was performed on Day 7 after stem-cell transplantation was performed on the rats with stroke. The rats from either the i-ADSCs (LS+) group or the i-ADSCs (LS?) group were unable to run as quickly as the rats in the sham group. From Day 14, the rats in the i-ADSCs (LS+) group gradually recovered the ability to run. By contrast, it was observed that the rats in the i-ADSCs (LS?) group recovered slightly; however, the degree of recovery was lower than that in the i-ADSCs (LS+) group. On Day 21 after stem-cell transplantation, the recovery of running function was still more satisfactory in the i-ADSCs (LS+) group than in the i-ADSCs (LS?) group. On Day 28, the motor function of the rats in the i-ADSCs (LS+) group was approaching the level of the rats in the sham group, whereas the performance of the rats in the i-ADSCs (LS?) group was still considerably weaker than that of the sham group (Figure 6).

Figure 6

The treadmill test for evaluating the recovery of the motor function of running in rats with ischemic stroke with i-ADSCs (LS?) and i-ADSCs (LS+) transplantation.

Grip-strength tests were performed on Day 7 after stem-cell transplantation. The findings were similar to the treadmill test results; the grip behavior of the rats in both the i-ADSCs (LS+) group and the i-ADSCs (LS?) group was worse than that of the rats in the sham group. On Day 14, the grip strength of the rats in the i-ADSCs (LS+) group was considerably recovered. By contrast, although the rats in the i-ADSCs (LS?) group showed some progress, the improvement was minimal. On Day 21, the rats in the i-ADSCs (LS+) group continued to recover, whereas it was observed that the animals in the i-ADSCs (LS?) group were not recovering as quickly. On Day 28, grip strength recovery in the i-ADSCs (LS+) group approached that of the sham group, whereas grip strength in the i-ADSCs (LS?) group was still lower (Figure 7).

Figure 7

The grip test for evaluating the recovery of grip strength in rats with ischemic stroke treated with i-ADSCs (LS?) and i-ADSCs (LS+) transplantation.

3.4. Repair of Brain Tissues after Treatment in Animals

After euthanizing the rats, the brain specimens were treated with paraffin and then sliced. The HE-immunostaining method was used to observe the repair of brain tissues after stem-cell transplantation was performed. An upright microscope (10x) was used to macroscopically observe the brain tissue, and the results showed that brain tissue was completely repaired in the rats in the i-ADSCs (LS+) group with nearly no necrotic brain tissue. By contrast, obvious necrotic scars were observed at the ischemic sites of the brain tissue from the rats in the i-ADSCs (LS?) group (Figure 8(a)). Observed under a microscope and magnified 200 times, the results showed that the brain tissue from the rats in the i-ADSCs (LS+) group was as dense as normal brain tissues, whereas numerous cavities were observed in the brain tissue from rats in the i-ADSCs (LS?) group (Figure 8(b)).

Figure 8

The observation of brain tissue necrosis in rats with ischemic stroke treated with i-ADSCs (LS?) (left) and i-ADSCs (LS+) (right) transplantation: (a) 10x; (b) 200x.

Oligodendrocytes, which are glial cells found in normal brains, form myelin in the central nervous system. Oligodendrocytes substantially decrease after brain cells are damaged, leading to myelin collapse and the loss of neural-signal conduction. Therefore, a western blot was used to analyze the amount of expression of the oligodendrocyte cell protein, oligo-2, to confirm the repair of brain tissues after stem-cell transplantation was performed in rats with stroke. The results showed that the amount of oligo-2 protein response in the brain tissues of the i-ADSCs (LS+) group was as high as that in the sham group. By contrast, the oligo-2 protein response in the i-ADSCs (LS?) group was substantially lower (P < 0.05). These results indicated that stem-cell transplantation treatments can repair brain tissues damaged by ischemia (Figure 9).

Figure 9

The observation of brain tissue repair in rats with ischemic stroke treated with i-ADSCs (LS?) and i-ADSCs (LS+) transplantation. (a) The amount oligo-2 expression. (b) Quantification. GAPDH served as the internal reference. *Significance (P < 

4. Discussion

Stem cells possess the ability to proliferate, regenerate, differentiate, and secrete cytokines. Previous studies have proven that stem-cell therapy substantially improves the damage caused by stroke. Stem cells are derived from various sites. Most previous studies have used bone marrow mesenchymal stem cells; however, we used adipose stem cells in the present study, which are easily accessible, and abundant and exhibit high differentiation and proliferation activity. Moreover, adipose stem cells do not trigger strong immune reactions (resulting in low exclusion) and rarely form teratomas. In the literature, it has been demonstrated that adipose stem cells are essential adult stem cells that differentiate into various mesoderm tissues similarly to bone marrow mesenchymal stem cells [2123]. Furthermore, adipose stem cells are more easily accessible than mesenchymal stem cells; therefore, adipose stem cells can be used as a substitute for bone marrow mesenchymal stem cells for repairing damaged tissues in the future. Adipose stem cells are generally more practical than bone marrow mesenchymal stem cells for use in research [2326].

In this study, we used large-area low-level laser irradiation to induce ADSCs to differentiate into neuronal cells. The MTT assay analysis showed that the cell activity of the i-ADSCs increased on Days 5 and 7 of culture after large-area low-level laser irradiation [2728]. However, although cell activity increased on both Days 5 and 7, the activity was also increased for the group that did not receive laser irradiation treatment. No significant difference was observed between the groups with or without laser treatment (P > 0.05). Previous studies have shown that, depending on irradiation parameters, various types of cell respond differently to laser irradiation [29]. Although the mechanism underlying this phenomenon remains obscure, several hypotheses have been proposed to explain the mechanism of laser action [30]. We speculate that the lack of significant effects might be attributable to the short duration of low-level laser irradiation, which might not provide sufficient energy to the ADSCs for them to facilitate proliferation. Alternatively, using low-level lasers on the ADSCs might not sufficiently enhance cell proliferation. Therefore, future studies should investigate the appropriate duration of low-level laser irradiation and determine how much energy is required to accelerate cell proliferation [31,32].

To understand if using large-area low-level lasers exerted a positive effect on cell differentiation, we used immunofluorescent staining and western blot analysis to evaluate whether these lasers were capable of accelerating the induction of cell differentiation [33]. The immunofluorescent staining results showed that the nestin level in the group with i-ADSCs treated using large-area low-level laser irradiation increased substantially compared with that of the group that did not receive laser treatment. This result indicated that large-area low-level laser can accelerate the differentiation of ADSCs into neuronal cells [3435]. LLLT has been demonstrated to regulate neuronal function both in vitro and in vivo. Previous studies have reported that laser treatments accelerated nerve cell sprouting and cell migration, which begin within 24 h of seeding. During the first week of cultivation, irradiated cultures contain a high number of neurons exhibiting large perikaria and branched neuronal fibers, which interconnect to form networks [36]. The possible mechanism of LLLT at the cellular level has been attributed to the acceleration of electron transfer reactions, resulting in the increase of reactive oxygen species and Ca2+as versatile second messengers [37]. Previous studies have shown that applying LLLT could influence cellular processes by altering DNA synthesis and protein expression [38], biomodulating cytoskeletal organization [39], and stimulating cellular proliferation [38]. Such properties suggest that LLLT, or interventions with similar neurobiological effects, can be used to treat neurodegeneration, a phenomenon that underlies debilitating clinical conditions.

However, no obvious differences were observed for GFAP and DCX in the test results. This can be explained by the differentiation agent used in this study, which exerts its effects primarily by inducing ADSCs to differentiate into NSCs. Therefore, although the ADSCs were treated using a low-level laser, they still did not differentiate into neural glia cells. The DCX protein can only be discovered after neurons have been formed from NSCs, which demonstrates that DCX is a late-stage protein that cannot be expressed when cells still exhibit the morphology of NSCs. Therefore, the amount of DCX expression is not affected by low-level laser exposure. Western blot analysis was used to determine the amount of nestin expression after i-ADSCs were exposed to large-area low-level laser irradiation and culture for 7 days. The results showed that the amount of nestin was higher with laser treatment. This is similar to the findings from the immunofluorescent-staining method, indicating that laser irradiation can accelerate the differentiation of ADSCs into neuronal cells. These results indicated that ADSCs can be induced to differentiate into neuronal cells after treatment by large-area laser irradiation for 10 min. Future studies should establish the precise duration of large-area LLLT required to achieve improved results.

In this study, treadmill and forepaws grip tests were used to evaluate motor function recovery after stem cell transplantation treatments in rats with stroke. The treadmill test results showed that the running function was weaker for the rats in the sham group on Day 7 after treatment. We speculate that this might have been because the brain-tissue lesion area from ischemia was too large; therefore, the transplanted stem cells did not have sufficient time to noticeably repair brain tissue. Therefore, the motor functions of the rats remained impaired on Day 7. When tested on Day 14, recoveries in motor functions were observed in both the i-ADSCs (LS?) and i-ADSCs (LS+) groups, with superior recovery in the i-ADSCs (LS+) group, indicating that the damaged brain tissue was repaired. On Day 21, the recovery of the rats’ running function was more satisfactory in the i-ADSCs (LS+) group than in the i-ADSCs (LS?) group, indicating that the brain tissue repair capability was superior to that in the i-ADSCs (LS+) group. When tested on Day 28, the running function of the rats in the i-ADSCs (LS+) group was close to that of the rats in the sham group. However, the motor function of the i-ADSCs (LS?) group remained impaired, indicating that hind-paw motor function recovery was accelerated after i-ADSCs (LS+) treatment.

The grip test results were similar to the treadmill test results. On Day 7 after stem-cell transplantation treatment of the rats with stroke, grip strength was low for both the i-ADSCs (LS+) group and i-ADSCs (LS?) groups because the damaged brain tissues were just about to be repaired; therefore, the forepaws of the rats remained weak. When tested on Day 14, no major improvement was observed in the grip strength of the rats in the i-ADSCs (LS?) group. By contrast, the grip strength improved considerably in the i-ADSCs (LS+) group, indicating that the brain tissue repair capability was more satisfactory in the i-ADSCs (LS+) group than in the i-ADSCs (LS?) group. On Days 21 and 28, the tests showed that grip strength recovery was more satisfactory in the i-ADSCs (LS+) group than in the i-ADSCs (LS?) group. On Day 28, the grip strength in the i-ADSCs (LS+) group recovered to a level close to that of the sham group, indicating that, after i-ADSCs (LS+) treatment, the damaged brain tissues of the rats with stroke were repaired quickly, enabling the recovery of forepaw-grip strength. Based on these results, we concluded that damaged brain tissues can be repaired faster and motor function can be recovered efficiently in rats with stroke after i-ADSCs (LS+) treatment.

The i-ADSCs could differentiate into neuronal cells after transplantation into the brain. As a result, they moved and repaired damaged cerebral tissue selectively and improved cerebral functions by enhancing angiogenesis, renewal of neurons, and proliferation of nerve cells [4041]. In this study, we used the HE-immunostaining method and western blot analysis to evaluate brain tissue repair on Day 28 after stem cell transplantation treatment was performed in rats with stroke. The results of immunostaining were observed using a microscope. The structures were magnified 200 times, which showed that the brain tissue in the stroke lesion was dense and similar to that of normal brain tissue in the i-ADSCs (LS+) group. By contrast, numerous cavities were observed in the ischemic lesions of the brain tissues of the rats in the i-ADSCs (LS?) group. These results indicated that necrotizing brain tissue after ischemia was quickly repaired when i-ADSCs (LS+) was used to treat the rats with stroke. We speculate that using i-ADSCs (LS+) treatment can accelerate the induction of ADSCs to differentiate into neuronal cells. Therefore, although the same number of stem cells was transplanted for treatment, a greater number of NSCs were observed in the i-ADSCs (LS+) group than in the i-ADSCs (LS?) group. Furthermore, because NSCs can protect damaged brain tissues from continuous deterioration, they can also help brain tissues to repair. Therefore, transplanting a greater amount of NSCs would likely assist in repairing brain tissues more effectively.

Regarding the results of the western blot analysis, the oligo-2 amounts after stem-cell transplantation treatment were analyzed. Because oligodendrocytes form myelin in the central nervous system, myelin levels collapse when oligodendrocytes die. Nerve conduction is delayed or interrupted after the death of oligodendrocytes, leading to limb disabilities. Therefore, the evaluation of oligo-2 could be a crucial reference in assessing the degree of brain tissue recovery after stem-cell transplantation treatments in rats with stroke. In this study, using western blot analysis showed that the amount of expression of oligo-2 in brain tissues treated with i-ADSCs (LS+) was similar to that in normal brain tissues. By contrast, brain tissues treated with i-ADSCs (LS?) exhibited a lower oligo-2 expression, indicating that using i-ADSCs (LS+) treatment in rats with stroke can repair myelin in the central nervous system, leading to the recovery of neural-signal conduction and motor function. Based on these experimental results, we concluded that using i-ADSCs (LS+) treatment in rats with stroke cannot only accelerate the repair of damaged brain tissues for the partial recovery of motor functions, but also enable the central nervous system to recover the velocity of neural-signal conduction. These results confirm that the transplantation of i-ADSCs (LS+) can accelerate repairs in rats with ischemic stroke because i-ADSCs (LS+) can more efficiently differentiate into NSCs.

5. Conclusion

In this study, we used i-ADSCs treated with large-area low-level laser irradiation to evaluate the effects of a low-level laser on cell proliferation and differentiation. The results showed that although a low-level laser cannot facilitate cell proliferation, it can accelerate the induction of ADSCs differentiating into NSCs. In this study, we successfully created large-area cell and tissue damage in rat brains by using an embolic stroke animal model. Stem-cell transplantation with either i-ADSCs (LS+) or i-ADSCs (LS?) was performed to evaluate the degree of repair after stroke in the animals. Because large-area low-level laser irradiation can accelerate the differentiation of ADSCs into NSCs, and NSCs can protect damaged brain tissues to prevent continuous deterioration from damage and to help with repair, the motor function recovery was thus superior in the rats treated using i-ADSCs (LS+) compared with that in the rats treated using i-ADSCs (LS?). From the brain tissue slices from each group of rats, we discovered that i-ADSCs (LS+) treatment more effectively repaired necrotizing brain tissues after ischemia in rat brains. Furthermore, the western blot analysis also showed that the amount of oligo-2 increased in i-ADSCs (LS+)-treated rats with stroke, confirming the repair of myelin in cerebral neurons to further assist in the recovery of neural-signal conduction in the central nervous system.

Therefore, in the present study we demonstrated that using large-area low-level lasers exerts positive effects on inducing ADSCs differentiation, and it effectively treated ischemic stroke in rats, regarding motor function recovery. In future studies, the effects of large-area low-level laser irradiation time and the appropriate dosage for the proliferation and differentiation of ADSCs should be evaluated. If the optimal irradiation time and dosage for ADSC proliferation and differentiation can be discovered in animal experiments similar to those in this study, we believe that superior experimental results can be obtained. Furthermore, if primate or canine experimental animals can be used to conduct the experimental protocols described herein, the concerns associated with individual animal differences and errors associated with motor function assessments can be minimized to obtain more reliable experimental data. Therefore, the findings of this study contribute to the development of cell therapy, which can benefit patients with stroke.

Conflict of Interests

There is no conflict of interests.

Acknowledgments

This work was supported by grants from the Taichung Veterans General Hospital and Central Taiwan University of Science and Technology (Grant. TCVGH-CTUST 1027701) and the National Science Council (Grant. NSC 102-2314-B-075A-019-MY2), Taiwan.

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Violet Light & MRSA (Methicillin-resistant Staphylococcus Aureus)

Photomed Laser Surg.  2013 Nov;31(11):547-53. doi: 10.1089/pho.2012.3461. Epub 2013 Apr 27.

Wavelength and Bacterial Density Influence the Bactericidal Effect of Blue Light on Methicillin-Resistant Staphylococcus aureus (MRSA).

Bumah VV, Masson-Meyers DS, Cashin SE, Enwemeka CS.

Author information

  • 1 College of Health Sciences, University of Wisconsin-Milwaukee , Milwaukee, Wisconsin.

Abstract

Abstract Objective: The purpose of this study was to investigate the effect of wavelength and methicillin-resistant Staphylococcus aureus (MRSA) density on the bactericidal effect of 405 and 470?nm light. Background data: It is recognized that 405 and 470 nm light-emitting diode (LED) light kill MRSA in standard 5×10(6) colony-forming units (CFU)/mL cultures; however, the effect of bacterial density on the bactericidal effect of each wavelength is not known.

Methods: In three experiments, we cultured and plated US300 MRSA at four densities. Then, we irradiated each plate once with either wavelength at 0, 1, 3, 45, 50, 55, 60, and 220 J/cm(2).

Results: Irradiation with either wavelength reduced bacterial colonies at each density (p<0.05). More bacteria were cleared as density increased; however, the proportion of colonies cleared, inversely decreased as density increased-the maximum being 100%, 96%, and 78% for 3×10(6), 5×10(6), and 7×10(6) CFU/mL cultures, respectively. Both wavelengths had similar effects on the sparser 3×10(6) and 5×10(6) CFU/mL cultures, but in the denser 7×10(6) CFU/mL culture, 405?nm light cleared more bacteria at each fluence (p<0.001). To determine the effect of beam penetration, denser 8×10(6) and 12×10(6) CFU/mL culture plates were irradiated either from the top, the bottom, or both directions. More colonies were eradicated from plates irradiated from top and bottom, than from plates irradiated from top or bottom at the same sum total fluences (p<0.001).

Conclusions: The bactericidal effect of LED blue light is limited more by light penetration of bacterial layers than by bacterial density per se.

Photomed Laser Surg. 2009 Apr;27(2):221-6.

Blue 470-nm light kills methicillin-resistant Staphylococcus aureus (MRSA) in vitro.

Enwemeka CS, Williams D, Enwemeka SK, Hollosi S, Yens D.

School of Health Professions, Behavioral, and Life Sciences, New York Institute of Technology, Old Westbury, New York 11568-8000, USA.Enwemeka@nyit.edu

BACKGROUND DATA: In a previous study, we showed that 405-nm light photo-destroys methicillin-resistant Staphylococcus aureus (MRSA). The 390-420 nm spectral width of the 405-nm superluminous diode (SLD) source may raise safety concerns in clinical practice, because of the trace of ultraviolet (UV) light within the spectrum.

OBJECTIVE: Here we report the effect of a different wavelength of blue light, one that has no trace of UV, on two strains of MRSA–the US-300 strain of CA-MRSA and the IS-853 strain of HA-MRSA–in vitro.

MATERIALS AND METHODS: We cultured and plated each strain, and then irradiated each plate with 0, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 25, 30, 35, 40, 45, 50, 55, or 60 J/cm2 of energy a single time, using a 470-nm SLD phototherapy device. The irradiated specimens were then incubated at 35 degrees C for 24 h. Subsequently, digital images were made and quantified to obtain colony counts and the aggregate area occupied by bacteria.

RESULTS: Photo-irradiation produced a statistically significant dose-dependent reduction in both the number and the aggregate area of colonies formed by each strain (p < 0.001). The higher the dose the more bacteria were killed, but the effect was not linear, and was more impressive at lower doses than at higher doses. Nearly 30% of both strains was killed with as little as 3 J/cm2 of energy. As much as 90.4% of the US-300 and the IS-853 colonies, respectively, were killed with an energy density of 55 J/cm2. This same dose eradicated 91.7% and 94.8% of the aggregate area of the US-300 and the IS-853 strains, respectively.

CONCLUSION: At practical dose ranges, 470-nm blue light kills HA-MRSA and CA-MRSA in vitro, suggesting that a similar bactericidal effect may be attained in human cases of cutaneous and subcutaneous MRSA infections.

Appl Environ Microbiol. 2009 Apr;75(7):1932-7. Epub 2009 Feb 6.

Inactivation of bacterial pathogens following exposure to light from a 405 nanometer light-emitting diode array.

Maclean M, MacGregor SJ, Anderson JG, Woolsey G.

The Robertson Trust Laboratory for Electronic Sterilisation Technologies, University of Strathclyde, 204 George Street, Glasgow, Scotland. michellemaclean@eee.strath.ac.uk

This study demonstrates the susceptibility of a variety of medically important bacteria to inactivation by 405-nm light from an array of light-emitting diodes (LEDs), without the application of exogenous photosensitizer molecules. Selected bacterial pathogens, all commonly associated with hospital-acquired infections, were exposed to the 405-nm LED array, and the results show that both gram-positive and gram-negative species were successfully inactivated, with the general trend showing gram-positive species to be more susceptible than gram-negative bacteria. Detailed investigation of the bactericidal effect of the blue-light treatment on Staphylococcus aureus suspensions, for a range of different population densities, demonstrated that 405-nm LED array illumination can cause complete inactivation at high population densities: inactivation levels corresponding to a 9-log(10) reduction were achieved. The results, which show the inactivation of a wide range of medically important bacteria including methicillin-resistant Staphylococcus aureus, demonstrate that, with further development, narrow-spectrum 405-nm visible-light illumination from an LED source has the potential to provide a novel decontamination method with a wide range of potential applications.

Photomed Laser Surg. 2006 Dec;24(6):684-8

In vitro bactericidal effects of 405-nm and 470-nm blue light.

Guffey JS, Wilborn J.

Physical Therapy Plus, Bauxite, Arkansas 72011, USA. drguffey@earthlink.net

OBJECTIVE: The aim of this study was to determine the bactericidal effect of 405- and 470-nm light on two bacteria, Staphylococcus aureus and Pseudomonas aeruginosa, in vitro.

BACKGROUND DATA: It is well-known that UV light kills bacteria, but the bactericidal effects of UV may not be unique since recent studies indicate that blue light produces a somewhat similar effect. The effects of blue light seem varied depending on wavelength, dose and the nature of the bacteria, hence this study.

METHODS: Two common aerobes, Staphylococcus aureus and Pseudomonas aeruginosa, and anaerobic Propionibacterium acnes were tested. Each organism was treated with Super Luminous Diode probes with peak emission at 405 and 470 nm. Treatment was timed to yield 1, 3, 5, 10, and 15 Jcm2 doses. Colony counts were performed and compared to untreated controls.

RESULTS: The 405-nm light produced a dose dependent bactericidal effect on Pseudomonas aeruginosa and Staphylococcus aureus (p < .05), achieving as much as 95.1% and nearly 90% kill rate for each, respectively. The 470-nm light effectively killed Pseudomonas aeruginosa at all dose levels, but only killed Staphylococcus aureus at 10 and 15 J cm2. With this wavelength, as much as 96.5% and 62% reduction of Pseudomonas aeruginosa and Staphylococcus aureus was achieved, respectively. Neither of the two wavelengths proved bactericidal with anaerobic Propionibacterium acnes.

CONCLUSION: The results indicate that, in vitro, 405- and 470-nm blue light produce dose dependent bactericidal effects on Pseudomonas aeruginosa and Staphylococcus aureus but not Propionibacterium acnes.

Photomed Laser Surg. 2006 Dec;24(6):680-3.

Effects of combined 405-nm and 880-nm light on Staphylococcus aureus and Pseudomonas aeruginosa in vitro.

Guffey JS, Wilborn J.

Physical Therapy Plus, Bauxite, Arkansas 72011, USA. drguffey@earthlink.net

OBJECTIVE: The aim of this study was to determine the effect of a combination of 405-nm blue light and 880-nm infrared light on Staphylococcus aureus and Pseudomonas aeruginosa in vitro.

BACKGROUND DATA: Reports indicate that certain wavelengths and treatment parameters of light promote the growth of bacteria, but our earlier study indicates that light at specific wavelengths and intensities are bactericidal for specific organisms (1).

METHODS: Two common aerobes, Staphylococcus aureus and Pseudomonas aeruginosa were tested because of their frequent isolation from skin infections and wounds. Each organism was treated simultaneously with a combination of 405-nm and 880-nm light emitted by a cluster of Super Luminous Diodes (SLDs). Doses of 1, 3, 5, 10, and 20 Jcm2 were used. Colony counts were performed and compared to untreated controls using Student t tests and one-way ANOVA with Tukey and Scheffe post hoc analyses.

RESULTS: The results revealed significant dose-dependent bactericidal effects of the combined blue and infrared light on Staphylococcus aureus (F 4,94 = 5.38, p = 0.001) and Pseudomonas aeruginosa (F 4,95 = 21.35, p < 0.001). With P. aeruginosa, the treatment reduced the number of bacteria colonies at all doses, achieving statistical significance at 1, 3, and 20 J cm2 doses and reducing bacterial colony by as much as 93.8%; the most effective dose being 20 J cm2. Irradiation of S. aureus resulted in statistically significant decreases in bacterial colonies at all dose levels; the most decrease, 72%, was also achieved with 20 Jcm2.

CONCLUSION: Appropriate doses of combined 405-nm and 880-nm phototherapy can kill Staphylococcus aureus and Pseudomonas aeruginosa in vitro, suggesting that a similar effect may be produced in clinical cases of bacterial infection.

Med Microbiol. 1995 Jan;42(1):62-6

Killing of methicillin-resistant Staphylococcus aureus by low-power laser light.

Wilson M, Yianni C.

Department of Microbiology, Eastman Dental Institute for Oral Health Sciences, University of London.

The purpose of this study was to determine whether a methicillin-resistant strain of Staphylococcus aureus (MRSA) could be sensitised by toluidine blue O (TBO) to killing by light from a low-power helium/neon (HeNe) laser. Suspensions containing c. 10(10) cfu of MRSA were irradiated with light from a 35 mW HeNe laser (energy dose: 0.5-2.1 J) in the presence of TBO (1.6-12.5 micrograms/ml) and the survivors were enumerated. The kills attained depended on both the light energy dose and concentration of TBO employed. A 4.47 log10 reduction in the viable count was achieved with a TBO concentration of 12.5 micrograms/ml and a light dose of 2.1 J (energy density 43 J/cm2). MRSA were susceptible to killing by the laser light within 30 s of exposure to the TBO. The results of this study have demonstrated that MRSA can be rapidly sensitised by TBO to killing by HeNe laser light and that killing depends on the light energy dose and sensitiser concentration.

Super-Pulsed Lasers

Lasers Med Sci. 2013 Jun 30. [Epub ahead of print]

What is the best treatment to decrease pro-inflammatory cytokine release in acute skeletal muscle injury induced by trauma in rats: low-level laser therapy, diclofenac, or cryotherapy?

de Almeida P, Tomazoni SS, Frigo L, de Carvalho PD, Vanin AA, Santos LA, Albuquerque-Pontes GM, De Marchi T, Tairova O, Marcos RL, Lopes-Martins RA, Leal-Junior EC.

Source

Postgraduate Program in Rehabilitation Sciences, Universidade Nove de Julho (UNINOVE), São Paulo, SP, Brazil.

Abstract

Currently, treatment of muscle injuries represents a challenge in clinical practice. In acute phase, the most employed therapies are cryotherapy and nonsteroidal anti-inflammatory drugs. In the last years, low-level laser therapy (LLLT) has becoming a promising therapeutic agent; however, its effects are not fully known. The aim of this study was to analyze the effects of sodium diclofenac (topical application), cryotherapy, and LLLT on pro-inflammatory cytokine levels after a controlled model of muscle injury. For such, we performed a single trauma in tibialis anterior muscle of rats. After 1 h, animals were treated with sodium diclofenac (11.6 mg/g of solution), cryotherapy (20 min), or LLLT (904 nm; superpulsed; 700 Hz; 60 mW mean output power; 1.67 W/cm2; 1, 3, 6 or 9 J; 17, 50, 100 or 150 s). Assessment of interleukin-1 and interleukin-6 (IL-1 and IL-6) and tumor necrosis factor-alpha (TNF-a)levels was performed at 6 h after trauma employing enzyme-linked immunosorbent assay method. LLLT with 1 J dose significantly decreased (p<0.05) IL-1, IL-6, and TNF-1 levels compared to non-treated injured group as well as diclofenac and cryotherapy groups. On the other hand, treatment with diclofenac and cryotherapy does not decrease pro-inflammatory cytokine levels compared to the non-treated injured group. Therefore, we can conclude that 904 nm LLLT with 1 J dose has better effects than topical application of diclofenac or cryotherapy in acute inflammatory phase after muscle trauma.

J Neurotrauma. 2013 Mar 15;30(6):480-6. doi: 10.1089/neu.2012.2603. Epub 2013 Mar 20.

Laser therapy and pain-related behavior after injury of the inferior alveolar nerve: possible involvement of neurotrophins.

de Oliveira Martins D, Martinez dos Santos F, Evany de Oliveira M, de Britto LR, Benedito Dias Lemos J, Chacur M.

Source

Laboratory of Functional Neuroanatomy of Pain, Department of Anatomy, University of São Paulo, São Paulo, Brazil.

 

Abstract

Nerve-related complications have been frequently reported in dental procedures, and a very frequent type of occurrence involves the inferior alveolar nerve (IAN). The nerve injury in humans often results in persistent pain accompanied by allodynia and hyperalgesia. In this investigation, we used an experimental IAN injury in rats, which was induced by a Crile hemostatic clamp, to evaluate the effects of laser therapy on nerve repair. We also studied the nociceptive behavior (von Frey hair test) before and after the injury and the behavioral effects of treatment with laser therapy (emitting a wavelength of 904nm, output power of 70 Wpk, a spot area of  0.1 cm², frequency of 9500 Hz, pulse time 60 ns and an energy density of 6 J/cm²). As neurotrophins are essential for the process of nerve regeneration, we used immunoblotting techniques to preliminarily examine the effects of laser therapy on the expression of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF). The injured animals treated with laser exhibited an improved nociceptive behavior. In irradiated animals, there was an enhanced expression of NGF (53%) and a decreased BDNF expression (40%) after laser therapy. These results indicate that BDNF plays a locally crucial role in pain-related behavior development after IAN injury, increasing after lesions (in parallel to the installation of pain behavior) and decreasing with laser therapy (in parallel to the improvement of pain behavior). On the other hand, NGF probably contributes to the repair of nerve tissue, in addition to improving the pain-related behavior.

Photomed Laser Surg. 2012 Dec;30(12):688-94. doi: 10.1089/pho.2012.3306. Epub 2012 Oct 1.

Skin penetration time-profiles for continuous 810 nm and Superpulsed 904 nm lasers in a rat model.

Joensen J, Ovsthus K, Reed RK, Hummelsund S, Iversen VV, Lopes-Martins RÁ, Bjordal JM.

Source

Department of Occupational Therapy, Physiotherapy, and Radiography, Bergen University College, Bergen, Norway. jon.joensen@hib.no

 

Abstract

OBJECTIVE:

The purpose of this study was to investigate the rat skin penetration abilities of two commercially available low-level laser therapy (LLLT) devices during 150 sec of irradiation.

BACKGROUND DATA:

Effective LLLT irradiation typically lasts from 20?sec up to a few minutes, but the LLLT time-profiles for skin penetration of light energy have not yet been investigated.

MATERIALS AND METHODS:

Sixty-two skin flaps overlaying rat's gastrocnemius muscles were harvested and immediately irradiated with LLLT devices. Irradiation was performed either with a 810 nm, 200 mW continuous wave laser, or with a 904 nm, 60 mW superpulsed laser, and the amount of penetrating light energy was measured by an optical power meter and registered at seven time points (range, 1-150 sec).

RESULTS:

With the continuous wave 810 nm laser probe in skin contact, the amount of penetrating light energy was stable at  20% (SEM±0.6) of the initial optical output during 150 sec irradiation. However, irradiation with the superpulsed 904 nm, 60 mW laser showed a linear increase in penetrating energy from 38% (SEM±1.4) to 58% (SEM±3.5) during 150 sec of exposure. The skin penetration abilities were significantly different (p<0.01) between the two lasers at all measured time points.

CONCLUSIONS:

LLLT irradiation through rat skin leaves sufficient subdermal light energy to influence pathological processes and tissue repair. The finding that superpulsed 904 nm LLLT light energy penetrates 2-3 easier through the rat skin barrier than 810 nm continuous wave LLLT, corresponds well with results of LLLT dose analyses in systematic reviews of LLLT in musculoskeletal disorders. This may explain why the differentiation between these laser types has been needed in the clinical dosage recommendations of World Association for Laser Therapy.

Vojnosanit Pregl. 2012 Aug;69(8):656-62.

Clinical and functional evaluation of patients with acute low back pain and radiculopathy treated with different energy doses of low level laser therapy.

Jovici M, Konstantinovi L, Lazovi M, Jovici V.

Source

Institute for Rehabilitation, Belgrade, Serbia. medi@eunet.rs

 

Abstract

BACKGROUND/AIM:

The main clinical phenomena in acute low back pain (LBP) with radiculopathy are pain and neurological disorders. Although some studies show that low level laser therapy (LLLT) has the ability to modulate inflammatory processes and relieve acute pain condition, the laser therapy dose protocol has not been yet completely established. The aim of this study was to investigate the effects of three different energy doses of LLLT in patients with acute LBP and radiculopathy.

METHODS:

The study included 66 patients with acute LBP and radiculopathy who had been randomly divided into three groups (22 patients each) received three different doses of LLLT. The patients were treated 5 times weekly, for a total of 10 treatments, with the following parameters: wave length 904 nm, frequency 3,000 Hz, average diode power 25 mW; energy dose of 0.1 J per point in the first group, 1 J per point in the second and 4 J per point in the third group; daily treatment time and accumulated energy were 16 s and 0.4 J in the first group, 160 s and 4J in the second group and 640 s and 16 J in the third group, respectively. The parameters of assessment before and after the therapy were: lumbar and leg pain measured by visual analogue scale (VAS), local and general functional changes (Schober test, manual muscle test, straight leg raise test and the modified North American Spine Society-Low Back Pain Outcome Instrument-NASS LBP).

RESULTS:

Highly significant improvements (p < 0.01) were noted in all the groups after LLLT with respect to all the investigated parameters. The VAS scores were significantly lower in all the groups without a difference between the groups (p > 0,05). Functional improvements were better in the third group treated with the dose of 4 J per point than in other two groups (p < 0.05).

CONCLUSIONS:

Three different energy doses of LLLT were equally effective in alleviating lumbar and leg pain without side effects, but the dose of 4 J per point seemed to be more effective in improving the activities of daily living and lumbar mobility.

Photomed Laser Surg. 2012 May;30(5):281-5. doi: 10.1089/pho.2011.3160. Epub 2012 Apr 17.

In vitro analysis of bacterial morphology by atomic force microscopy of low level laser therapy 660, 830 and 904 nm.

de Sousa NT, Guirro RR, Santana HF, Silva CC.

Source

Department of Physical Therapy, FAMINAS-School of Minas, Minas Gerais, Brazil.

 

Abstract

OBJECTIVE:

The objective of this study was to analyze the bacterial morphology by atomic force microscopy (AFM) after the application of low-level laser therapy (LLLT) in in vitro culture of Staphylococcus aureus ATCC 29213.

BACKGROUND DATA:

Infections caused by S. aureus are among the highest occurring in hospitals and can often colonize pressure ulcers. LLLT is among the methods used to accelerate the healing of ulcers. However, there is no consensus on its effect on bacteria.

MATERIALS AND METHODS:

After being cultivated and seeded, the cultures were irradiated using wavelengths of 660, 830, and 904 nm at fluences of 0, 1, 2, 3, 4, 5, and 16 J/cm(2). Viable cells of S. aureus strain were counted after 24 h incubation. To analyze the occurrence of morphological changes, the topographical measurement of bacterial cells was analyzed using the AFM.

RESULTS:

The overall assessment revealed that the laser irradiation reduced the S. aureus growth using 830 and 904 nm wavelengths; the latter with the greatest inhibition of the colony-forming units (CFU/mL) (331.1±38.19 and 137.38±21.72). Specifically with 660 nm, the statistical difference occurred only at a fluence of 3 J/cm(2). Topographical analysis showed small changes in morphological conformity of the samples tested.

CONCLUSIONS:

LLLT reduced the growth of S. aureus with 830 and 904 nm wavelengths, particularly with 904 nm at a fluence of 3 J/cm(2), where the greatest topographical changes of the cell structure occurred.

Lasers Med Sci. 2013 Feb;28(2):431-6. doi: 10.1007/s10103-012-1075-6. Epub 2012 Mar 8.

Effects of low-level laser therapy (GaAs) in an animal model of muscular damage induced by trauma.

Silveira PC, da Silva LA, Pinho CA, De Souza PS, Ronsani MM, Scheffer Dda L, Pinho RA.

Source

Laboratório de Fisiologia e Bioquímica do Exercício, Universidade do Extremo Sul Catarinense, Av. Universitária, 1105-Bairro Universitário, 88806-000, Criciúma, SC, Brazil, silveira_paulo2004@yahoo.com.br.

 

Abstract

It has been demonstrated that reactive oxygen species (ROS) formation and oxidative damage markers are increased after muscle damage. Recent studies have demonstrated that low-level laser therapy (LLLT) modulates many biochemical processes mainly those related to reduction of muscular injures, increment of mitochondrial respiration and ATP synthesis, as well as acceleration of the healing process. The objective of the present investigation was to verify the influence of LLLT in some parameters of muscular injury, oxidative damage, antioxidant activity, and synthesis of collagen after traumatic muscular injury. Adult male Wistar rats were divided randomly into three groups (n=6), namely, sham (uninjured muscle), muscle injury without treatment, and muscle injury with LLLT (GaAs, 904 nm). Each treated point received 5 J/cm(2) or 0.5 J of energy density (12.5 s) and 2.5 J per treatment (five regions). LLLT was administered 2, 12, 24, 48, 72, 96, and 120 h after muscle trauma. The serum creatine kinase activity was used as an index of skeletal muscle injury. Superoxide anion, thiobarbituric acid reactive substance (TBARS) measurement, and superoxide dismutase (SOD) activity were used as indicators of oxidative stress. In order to assess the synthesis of collagen, levels of hydroxyproline were measured. Our results have shown that the model of traumatic injury induces a significant increase in serum creatine kinase activity, hydroxyproline content, superoxide anion production, TBARS level, and activity of SOD compared to control. LLLT accelerated the muscular healing by significantly decreasing superoxide anion production, TBARS levels, the activity of SOD, and hydroxyproline content. The data strongly indicate that increased ROS production and augmented collagen synthesis are elicited by traumatic muscular injury, effects that were significantly decreased by LLLT.

Lasers Med Sci. 2012 Sep;27(5):993-1000. doi: 10.1007/s10103-011-1031-x. Epub 2011 Dec 6.

GaAs 904-nm laser irradiation improves myofiber mass recovery during regeneration of skeletal muscle previously damaged by crotoxin.

Silva LH, Silva MT, Gutierrez RM, Conte TC, Toledo CA, Aoki MS, Liebano RE, Miyabara EH.

Source

Department of Anatomy, Biomedical Sciences Institute, University of São Paulo, Lineu Prestes Av., 2415, 05508-000, São Paulo, SP, Brazil.

 

Abstract

This work investigated the effect of gallium arsenide (GaAs) irradiation (power: 5 mW; intensity: 77.14 mW/cm(2), spot: 0.07 cm(2)) on regenerating skeletal muscles damaged by crotoxin (CTX). Male C57Bl6 mice were divided into six groups (n?=?5 each): control, treated only with laser at doses of 1.5 J or 3 J, CTX-injured and, CTX-injured and treated with laser at doses of 1.5 J or 3 J. The injured groups received a CTX injection into the tibialis anterior (TA) muscle. After 3 days, TA muscles were submitted to GaAs irradiation at doses of 1.5 or 3 J (once a day, during 5 days) and were killed on the eighth day. Muscle histological sections were stained with hematoxylin and eosin (H&E) in order to determine the myofiber cross-sectional area (CSA), the previously injured muscle area (PIMA) and the area density of connective tissue. The gene expression of MyoD and myogenin was detected by real-time PCR. GaAs laser at a dose of 3 J, but not 1.5 J, significantly increased the CSA of regenerating myofibers and reduced the PIMA and the area density of intramuscular connective tissue of CTX-injured muscles. MyoD gene expression increased in the injured group treated with GaAs laser at a dose of 1.5 J. The CTX-injured, 3-J GaAs laser-treated, and the CTX-injured and treated with 3-J laser groups showed an increase in myogenin gene expression when compared to the control group. Our results suggest that GaAs laser treatment at a dose of 3 J improves skeletal muscle regeneration by accelerating the recovery of myofiber mass.

Photomed Laser Surg. 2011 Aug;29(8):565-71. doi: 10.1089/pho.2010.2921. Epub 2011 Jun 1.

Influence of superpulsed laser therapy on healing processes following tooth extraction.

Mozzati M, Martinasso G, Cocero N, Pol R, Maggiora M, Muzio G, Canuto RA.

Source

Oral Surgery Unit, Dentistry Section, Department of Biomedical Sciences and Human Oncology, School of Dentistry, University of Turin, Turin, Italy.

 

Abstract

OBJECTIVE:

This research studied the effects of laser therapy on healing processes following tooth extraction in healthy human subjects, evaluating some inflammation, osteogenesis, and clinical parameters.

BACKGROUND DATA:

Alveolar healing following tooth extraction is a complex repair process involving different types of tissues, including epithelium and bone. Therefore, it can be advantageous to use techniques able to influence the healing of all tissues.

PATIENTS AND METHODS:

Ten healthy human subjects with indications for bilateral tooth extraction entered the split-mouth study. The subject/patient becomes his/her own control, thereby eliminating all individual differences in response to laser treatment. This consisted of: 904-nm laser, 33? W peak power, 30? KHz, 200? ns, average power 200? mW, illuminated area 1?cm(2), 200? mW/cm(2), 15? min, 180? J, 180 ?J/cm(2). In each patient, one post-extraction site was treated with laser radiation, whereas the other was left untreated as a control. Soft-tissue specimens were removed from the extraction site before tooth extraction (T0) and 7 days after from extraction (T7); expression of inflammatory and osteogenesis parameters was evaluated on these specimens. The clinical parameter "pain" was evaluated for each subject.

RESULTS:

Superpulsed laser irradiation prevented the increase of interleukin (IL)-1B, IL-6, IL-10, and cyclooxygenase-2 (COX-2), and induced an insignificant increase in collagen at 7 days after extraction, versus levels on day of extraction; no changes were found in the other parameters examined. Patients reported less pain at the site treated with superpulsed laser irradiation than at the control site.

CONCLUSIONS:

This study suggests that superpulsed laser irradiation may be a treatment of choice for patients scheduled for tooth extraction, as it provides clinical efficacy, is safe and well tolerated, and is able to prevent inflammation.

Lasers Med Sci. 2012 Jan;27(1):103-11. doi: 10.1007/s10103-011-0925-y. Epub 2011 May 6.

An experimental study of low-level laser therapy in rat Achilles tendon injury.

Joensen J, Gjerdet NR, Hummelsund S, Iversen V, Lopes-Martins RA, Bjordal JM.

Source

Department of Physiotherapy, Faculty of Health and Social Science, Bergen University College, Bergen, Norway. jon.joensen@hib.no

 

Abstract

The aim of this controlled animal study was to investigate the effect of low-level laser therapy (LLLT) administered 30 min after injury to the Achilles tendon. The study animals comprised 16 Sprague Dawley male rats divided in two groups. The right Achilles tendons were injured by blunt trauma using a mini guillotine, and were treated with LLLT or placebo LLLT 30 min later. The injury and LLLT procedures were then repeated 15 hours later on the same tendon. One group received active LLLT (904 nm, 60 mW mean output power, 0.158 W/cm(2) for 50 s, energy 3 J) and the other group received placebo LLLT 23 hours after LLLT. Ultrasonographic images were taken to measure the thickness of the right and left Achilles tendons. Animals were then killed, and all Achilles tendons were tested for ultimate tensile strength (UTS). All analyses were performed by blinded observers. There was a significant increase in tendon thickness in the active LLLT group when compared with the placebo group (p < 0.05) and there were no significant differences between the placebo and uninjured left tendons. There were no significant differences in UTS between laser-treated, placebo-treated and uninjured tendons. Laser irradiation of the Achilles tendon at 0.158 W/cm(2) for 50 s (3 J) administered within the first 30 min after blunt trauma, and repeated after 15 h, appears to lead to edema of the tendon measured 23 hours after LLLT. The guillotine blunt trauma model seems suitable for inflicting tendon injury and measuring the effects of treatment on edema by ultrasonography and UTS. More studies are needed to further refine this model.

Photomed Laser Surg. 2011 Jul;29(7):447-52. doi: 10.1089/pho.2010.2835. Epub 2011 Jan 16.

Observation of pain control in patients with bisphosphonate-induced osteonecrosis using low level laser therapy: preliminary results.

Romeo U, Galanakis A, Marias C, Vecchio AD, Tenore G, Palaia G, Vescovi P, Polimeni A.

Source

Department of Oral Sciences, "Sapienza" University of Rome, Italy. umberto.romeo@uniroma1.it

 

Abstract

BACKGROUND:

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is an adverse side effect associated with bisphosphonate (BP) therapy, especially when parenteral BP administration is used. Patients affected by BRONJ present wide areas of exposed necrotic bone, particularly after surgical oral procedures. The main symptom is pain that is poorly controlled by common analgesic drugs. Recently, many studies have pointed to the beneficial effect of low-level laser therapy (LLLT) in pain reduction for many pathological conditions. The purpose of this study is to investigate whether LLLT could be helpful in managing BRONJ by reducing the problems associated with this condition and the use of analgesic drugs.

METHODS:

Twelve patients affected by BRONJ were monitored at the Complex Operative Unit of Oral Pathology. Among these patients, only seven referred to pain in necrotic areas and were recruited for LLLT. Laser applications were performed with a double diode laser simultaneously emitting at two different wavelengths (650 nm and 904-910 nm, spot size = 8 mm). All of the patients were irradiated with a fluence of 0.053 J/cm(2) for 15 min five times over a period of 2 weeks, in a non-contact mode,  1 mm from the pathologic area. The patient's maximum and minimum pain was recorded using a numeric rating scale (NRS) evaluation before and after the treatment. Statistical analysis was performed using the Kruskal-Wallis test.

RESULTS:

Six patients showed significant pain reduction, and only one patient indicated a worsening of the symptoms, which was probably related to a reinfection of the BRONJ site, which occurred during the study. A statistically significant difference (p < 0.05) was found between the NRS rates before and after the protocol.

CONCLUSIONS:

This pilot study suggests that LLLT may be a valid technique to support the treatment of BRONJ-related pain, even though the low number of cases in this study does not permit any conclusive consideration.

Photomed Laser Surg. 2011 Mar;29(3):145-53. doi: 10.1089/pho.2010.2793. Epub 2011 Jan 10.

The thermal effects of therapeutic lasers with 810 and 904 nm wavelengths on human skin.

Joensen J, Demmink JH, Johnson MI, Iversen VV, Lopes-Martins RÁ, Bjordal JM.

Source

Department of Physiotherapy, Faculty of Health and Social Science, Bergen University College, Bergen, Norway. jon.joensen@hib.no

 

Abstract

OBJECTIVE:

To investigate the effect of therapeutic infrared class 3B laser irradiation on skin temperature in healthy participants of differing skin color, age, and gender.

BACKGROUND:

Little is known about the potential thermal effects of Low Level Laser Therapy (LLLT) irradiation on human skin.

METHODS:

Skin temperature was measured in 40 healthy volunteers with a thermographic camera at laser irradiated and control (non-irradiated) areas on the skin. Six irradiation doses (2-12 J) were delivered from a 200 mW, 810 nm laser and a 60 mW, 904 nm laser, respectively.

RESULTS:

Thermal effects of therapeutic LLLT using doses recommended in the World Association for Laser Therapy (WALT) guidelines were insignificant; below 1.5°C in light, medium, and dark skin. When higher irradiation doses were used, the 60 mW, 904 nm laser produced significantly (p<0.01) higher temperatures in dark skin (5.7, SD± 1.8°C at 12 J) than in light skin, although no participants requested termination of LLLT. However, irradiation with a 200 mW, 810 nm laser induced three to six times more heat in dark skin than in the other skin color groups. Eight of 13 participants with dark skin asked for LLLT to be stopped because of uncomfortable heating. The maximal increase in skin temperature was 22.3°C.

CONCLUSIONS:

The thermal effects of LLLT at doses recommended by WALT-guidelines for musculoskeletal and inflammatory conditions are negligible (<1.5°C) in light, medium, and dark skin. However, higher LLLT doses delivered with a strong 3B laser (200 mW) are capable of increasing skin temperature significantly and these photothermal effects may exceed the thermal pain threshold for humans with dark skin color.

Photomed Laser Surg. 2011 Mar;29(3):171-5. doi: 10.1089/pho.2010.2792. Epub 2010 Nov 6.

The effect of low-level laser therapy on salivary glands in patients with xerostomia.

Loncar B, Stipetic MM, Baricevic M, Risovic D.

Source

Department of Oral Medicine, School of Dental Medicine, University of Zagreb, Zagreb, Croatia. loncar@sfzg.hr

 

Abstract

OBJECTIVE:

The aim of this study was to investigate the effect of low-level laser irradiation on the secretory function of salivary glands in 34 patients with xerostomia (dry mouth).

BACKGROUND DATA:

Xerostomia, a common complaint of oral dryness within the elderly population, is caused by a reduction in normal salivary secretion due to different causes. Treatment is aimed at increasing salivary flow, although in most cases it remains palliative.

MATERIALS AND METHODS:

In this study, laser light from a pulsed Ga-As laser operating at 904 nm was applied bilaterally on each salivary gland area: extraorally on the parotid and submandibular gland areas and intraorally on the sublingual gland area. The operational probe distance from the irradiated area was 0.5 cm resulting in an irradiance of 246 mW/cm(2). The exposure time was 120 sec per daily treatment during 10 consecutive days. The average energy density per exposure was 29.5 J/cm(2). The control group consisted of 16 patients who were treated with 15 mL of a 2% citric acid solution applied as a mouth rinse for 30 sec.

RESULTS:

The average difference in the amount of salivation (dQ-sal, mL/min) before and after laser therapy increased linearly from dQ-sal=0.05 mL/min on the first day, up to dQ-sal = 0.13 mL/min on the last (10th) day of therapy. In the control group, the average dQ-sal initially demonstrated a gradual increase, with a reversal of the trend toward the end of the therapy period and eventually yielding no correlation between the duration of therapy and dQ-sal.

CONCLUSION:

The results of our study indicate that the effects of low-level laser therapy on salivary glands are not only stimulating, but also regenerative to a degree since the glandular response to the same amount of applied laser energy increased linearly over time.

Photomed Laser Surg. 2010 Oct;28 Suppl 2:S99-103. doi: 10.1089/pho.2009.2655. Epub 2010 Aug 25.

Effect of low-level laser irradiation on unresponsive oral lichen planus: early preliminary results in 13 patients.

Cafaro A, Albanese G, Arduino PG, Mario C, Massolini G, Mozzati M, Broccoletti R.

Source

Oral Medicine Unit, Dentistry Section, Department of Biological Sciences and Human Oncology, University of Turin, Turin, Italy.

 

Abstract

OBJECTIVE:

To detail the efficacy of low-level laser therapy (LLLT) for the management of oral lichen planus (OLP) unresponsive to standard therapy.

BACKGROUND:

OLP is an inflammatory disease that can be painful, mainly in the atrophic and erosive forms. Numerous drugs have been used with dissimilar results, but most treatments are empiric. However, to date, the most commonly used and useful agents for the treatment of OLP are topical corticosteroids.

MATERIALS AND METHODS:

The investigators studied a prospective cohort of 13 patients affected by OLP, who received biostimulation with a pulsed diode laser (GaAs). Patients were exposed to a 904-nm pulsed infrared laser (4 J/cm(2) energy density per minute; spot size, 0.8 cm). Outcome variables, statistically evaluated, were as follows: the size of lesions, visual analogue score of pain, and stability of the obtained result in the follow-up period.

RESULTS:

We detailed significant reduction in lesion size and in reported pain. No reported complications or therapy side effects were observed in any of the patients treated.

CONCLUSION:

This study suggests that LLLT could be a possible treatment for patients with unresponsive OLP. These results, although not conclusive, are a step forward for enhanced management of this quite common condition; however, it would be interesting to the results would be the same with a greater number of patients or in a different clinical setting.

Photomed Laser Surg. 2010 Apr;28(2):167-71. doi: 10.1089/pho.2008.2269.

Laser biomodulation on L 929 cell culture.

Pires-Oliveira DA, Oliveira RF, Machado AH, Zângaro RA, Pacheco-Soares C.

Source

Universidade Camilo Castelo Branca, Unicastelo, São Paulo, Brazil.

 

Abstract

OBJECTIVE:

The aim of the present study was to analyze the effects of photobiomodulation using a 904-nm diode laser at two energy densities (6 J/cm(2) and 50 mJ/cm(2)) on L929 fibroblast cells.

BACKGROUND:

Low-power laser irradiation (LPLI) is a non-pharmacological resource that induces important in vitro photobiomodulation on cell cultures and tissues.

METHODS:

Irradiation was performed for three days at 24-h intervals. After each interval, the cells were stained with MitoTracker Orange and DioC6 dyes to assess the photobiomodulatory effects of irradiation on mitochondrial activity and changes in the endoplasmic reticulum. The MTT assay [3-(4.5-dimethylthiazol-2-yl)-2.5 diphenyltetrazolium bromide] was used to evaluate cell proliferation.

RESULTS AND CONCLUSIONS:

The fluorescence microscopy assessment of mitochondria and endoplasmic reticulum in cells irradiated with 6 J/cm(2) and 50 mJ/cm(2) demonstrated intense mitochondrial activity, which was confirmed by DioC6 staining. Reticular activity was observed stemming from increased protein synthesis. Photobiomodulation with 50 mJ/cm(2) was slightly higher than with 6 J/cm(2), as demonstrated by fluorescence microscopy results. Photobiomodulation was also time-dependent, with better results 72-h after irradiation.

Osteoporos Int. 2010 Dec;21(12):2109-14. doi: 10.1007/s00198-010-1183-8. Epub 2010 Mar 4.

Laser 904 nm action on bone repair in rats with osteoporosis.

Pires-Oliveira DA, Oliveira RF, Amadei SU, Pacheco-Soares C, Rocha RF.

Source

Programa de Pós Graduação-Unicastelo, Departamento Curso de Odontologia, Universidade Camilo Castelo Branco-Unicastelo São Paulo, Rua Carolina Fonseca 584, Itaquera, São Paulo, São Paulo, CEP-08.230-030, Brazil. deisepyres@yahoo.com.br

 

Abstract

SUMMARY:

The aim of the present study was to determine the action of AsGA laser irradiation on bone repair in the tibia of osteopenic rats. The animals were randomly divided into eight experimental groups according to the presence of ovarian hormone (sham group) or the absence of the hormone (OVX group), as well as being irradiated or non-irradiated. Low-level 904-nm laser (50 mJ/cm(2)) accelerated the repair process of osteopenic fractures, especially in the initial phase of bone regeneration.

INTRODUCTION:

The development of new techniques to speed the process of bone repair has provided significant advances in the treatment of fractures. Some attention recently focused on the effects of biostimulation on bone.

METHODS:

Forty-eight adult rats were randomly divided into eight experimental groups (six animals in each group) according to the presence of ovarian hormone (sham group) or absence of the hormone (ovariectomized (OVX) group) as well as being irradiated or non-irradiated. For the application of low-level laser therapy, the animals were anesthetized with one third of the dose sufficient to immobilize the animal and irradiated with AsGa laser (904 nm, 50 mJ/cm(2) for 2 s, point form and in contact). The control animals received the same type of manipulation as the irradiated animals, but with the laser turned off. Half of the animals were killed 7 days following the confection of the bone defect, and the other half were killed 21 days after the surgery. After complete demineralization, the tibias were cut cross-sectionally in the central region of the bone defect and embedded in paraffin blocks. The blocks were then cut in semi-seriated slices and stained with hematoxylin and eosin.

RESULTS:

There was new bone formation in the animals in the OVX group with laser treatment killed after 7 days (p < 0.001). The lowest percentage of bone formation was observed in the OVX without laser killed after 7 days (p > 0.05). All animals killed after 21 days exhibited linear closure of the lesion.

CONCLUSION:

Low-level 904-nm laser (50 mJ/cm(2)) accelerated the repair process of osteopenic fractures, especially in the initial phase of bone regeneration.

Eur J Appl Physiol. 2010 Apr;108(6):1083-8. doi: 10.1007/s00421-009-1321-1. Epub 2009 Dec 19.

Effect of low-level laser therapy (GaAs 904 nm) in skeletal muscle fatigue and biochemical markers of muscle damage in rats.

Leal Junior EC, Lopes-Martins RA, de Almeida P, Ramos L, Iversen VV, Bjordal JM.

Source

Section for Physiotherapy Science, Department of Public Health and Primary Health Care, University of Bergen (UiB), Kalfarveien 31, 5020 Bergen, Norway. ernesto.leal.junior@gmail.com

 

Abstract

We wanted to test if pre-exercise muscle irradiation with 904 nm laser affects the development of fatigue, blood lactate levels and creatine kinase (CK) activity in a rat model with tetanic contractions. Thirty male Wistar rats were divided into five groups receiving either one of four different laser doses (0.1, 0.3, 1.0 and 3.0 J) or a no-treatment control group. Laser irradiation was performed immediately before the first contraction for treated groups. Electrical stimulation was used to induce six tetanic tibial anterior muscle contractions with 10 min intervals between them. Contractions were stopped when the muscle force fell to 50% of the peak value for each contraction; blood samples were taken before the first and immediately after the sixth contraction. The relative peak forces for the sixth contraction were significantly better (P < 0.05) in the two laser groups irradiated with highest doses [151.27% (SD +/- 18.82) for 1.0 J, 144.84% (SD +/- 34.47) for 3.0 J and 82.25% (SD +/- 11.69) for the control group]. Similar significant (P < 0.05) increases in mean performed work during the sixth contraction for the 1.0 and 3.0 J groups were also observed. Blood lactate levels were significantly lower (P < 0.05) than the control group in all irradiated groups. All irradiated groups except the 3.0 J group had significantly lower post-exercise CK activity than the control group. We conclude that pre-exercise irradiation with a laser dose of 1.0 J and 904 nm wavelength significantly delays muscle fatigue and decreases post-exercise blood lactate and CK in this rat model.

Photomed Laser Surg. 2010 Aug;28(4):553-60. doi: 10.1089/pho.2009.2576.

Acute low back pain with radiculopathy: a double-blind, randomized, placebo-controlled study.

Konstantinovic LM, Kanjuh ZM, Milovanovic AN, Cutovic MR, Djurovic AG, Savic VG, Dragin AS, Milovanovic ND.

Source

Clinic for Rehabilitation, Medical School, Belgrade, Serbia. ljkonstantinovic@yahoo.com

 

Abstract

OBJECTIVE:

The aim of this study was to investigate the clinical effects of low-level laser therapy (LLLT) in patients with acute low back pain (LBP) with radiculopathy.

BACKGROUND DATA:

Acute LBP with radiculopathy is associated with pain and disability and the important pathogenic role of inflammation. LLLT has shown significant anti-inflammatory effects in many studies.

MATERIALS AND METHODS:

A randomized, double-blind, placebo-controlled trial was performed on 546 patients. Group A (182 patients) was treated with nimesulide 200 mg/day and additionally with active LLLT; group B (182 patients) was treated only with nimesulide; and group C (182 patients) was treated with nimesulide and placebo LLLT. LLLT was applied behind the involved spine segment using a stationary skin-contact method. Patients were treated 5 times weekly, for a total of 15 treatments, with the following parameters: wavelength 904 nm; frequency 5000 Hz; 100-mW average diode power; power density of 20 mW/cm(2) and dose of 3 J/cm(2); treatment time 150 sec at whole doses of 12 J/cm(2). The outcomes were pain intensity measured with a visual analog scale (VAS); lumbar movement, with a modified Schober test; pain disability, with Oswestry disability score; and quality of life, with a 12-item short-form health survey questionnaire (SF-12). Subjects were evaluated before and after treatment. Statistical analyses were done with SPSS 11.5.

RESULTS:

Statistically significant differences were found in all outcomes measured (p < 0.001), but were larger in group A than in B (p < 0.0005) and C (p < 0.0005). The results in group C were better than in group B (p < 0.0005).

CONCLUSIONS:

The results of this study show better improvement in acute LBP treated with LLLT used as additional therapy.

Photomed Laser Surg. 2010 Jun;28(3):431-4. doi: 10.1089/pho.2008.2410.

Effect of GaAlAs laser irradiation on enzyme activity.

Da Silva NS, Potrich JW.

Source

Laboratório de Biologia Celular & Tecidual, Instituto de Pesquisa & Desenvolvimento, UNIVAP, São José dos Campos, Brazil. nsoares@univap.br

 

Abstract

OBJECTIVE:

The aim of this study was to determine the influence of laser irradiation on enzyme activity.

BACKGROUND DATA:

Enzymes are catalysts of extraordinary efficiency, able to accelerate reactions by manifold. Enzyme laser light activation is currently a fast-growing field and a large number of studies have been produced.

MATERIALS AND METHODS:

Liquid CNPG amylase and control serum (Qualitrol 1H) were used in the experiments. Laboratory analysis of alpha-amylase was performed on two sample groups: (i) E + S and (ii) E + S + L, in six repetitions per irradiation dose. Group 2 was irradiated with gallium-aluminum-arsenide (GaAlAs) 904 nm at doses of 0.01, 0.1, 0.5, and 1 J/cm(2). Enzyme activity was read using a spectrophotometer equipped with a thermostatic chamber capable of precise absorbance measurement at 405 nm.

RESULTS:

The results were analyzed with the Student's t-test, and the percentage of enzyme activity was determined. Photomodulation of alpha-amylase activity by GaAlAs laser was analyzed following irradiation with different doses. Irradiation doses from 0.01 to 1 J/cm(2) led to differences in enzyme activity: 0.01 J/cm(2) (0.10%), 0.1 J/cm(2) (13.44%), 0.5 J/cm(2) (12.57%), and 1 J/cm(2) (-6.10%).

CONCLUSION:

Irradiation doses of 0.1 J/cm(2) and 0.5 J/cm(2) led to statistically significant increases in enzyme activity in comparison to the control. The similar curves of the effects of temperature and pH on enzymatic activity observed in this study suggest that laser irradiation also possess an optimum dose to modulate the enzymatic activity. That is, enzymes have an optimum laser dose (or range) at which their activity is maximal, whereas at higher or lower doses activity decreases.

Lasers Med Sci. 2010 Mar;25(2):275-81. doi: 10.1007/s10103-009-0737-5.

Ultrasonographic evaluation of plantar fasciitis after low-level laser therapy: results of a double-blind, randomized, placebo-controlled trial.

Kiritsi O, Tsitas K, Malliaropoulos N, Mikroulis G.

Source

Prognosis, Diagnostic Center, Larnaca, Zaka 56, 56727 Thessaloniki, Greece. kirolga@hotmail.com

 

Abstract

The aim of this study was to investigate the effect of low-level laser therapy (LLLT) on plantar fasciitis documented by the ultrasonographic appearance of the aponeurosis and by patients' pain scores. Thirty individuals with diagnosis of unilateral plantar fasciitis were enrolled in a randomized, double-blind, placebo-controlled trial, but 25 participants completed the therapeutic protocol. The contralateral asymptomatic fascia was used as control. After enrolment, symptomatic individuals were randomly assigned to receive LLLT, or identical placebo, for 6 weeks. Ultrasonography was performed at baseline and after completion of therapy. The subjective subcalcaneal pain was recorded at baseline and after treatment on a visual analogue scale (VAS). After LLLT, plantar fascia thickness in both groups showed significant change over the experimental period and there was a difference (before treatment and after treatment) in plantar fascia thickness between the two groups. However, plantar fascia thickness was insignificant (mean 3.627 +/- 0.977 mm) when compared with that in the placebo group (mean 4.380 +/- 1.0042 mm). Pain estimation on the visual analogue scale had improved significantly in all test situations (after night rest, daily activities) after LLLT when compared with that of the placebo group. (P=0.006 and P=0.01, respectively). Additionally, when the difference in pain scores was compared between the two groups, the change was statistically significant (after night rest P=0.000; daily activities P=0.001). In summary, while ultrasound imaging is able to depict the morphologic changes related to plantar fasciitis, 904 nm gallium-arsenide (GaAs) infrared laser may contribute to healing and pain reduction in plantar fasciitis.

Photomed Laser Surg. 2010 Aug;28(4):459-63. doi: 10.1089/pho.2009.2524.

Analysis of low-level laser radiation transmission in occlusive dressings.

de Jesus Guirro RR, de Oliveira Guirro EC, Martins CC, Nunes FR.

Source

Department of Biomechanics, Medicine and Rehabilitation of the Locomotor System, School of Medicine of Ribeirão Preto, University São Paulo, Brazil. rguirro@fmrp.usp.br

 

Abstract

OBJECTIVE:

The purpose of this study is to analyze the power transmitted by low-level laser therapy (LLLT) into occlusive dressings using different wavelengths for the treatment of cutaneous lesions.

BACKGROUND DATA:

LLLT has been largely used to treat several cutaneous lesions commonly associated with occlusive dressings to accelerate the healing process.

MATERIALS AND METHODS:

Radiation transmission was measured by a digital power analyzer connected to a laser emitter with wavelengths of 660, 830, and 904 nm and mean levels of 30, 30, 6.5 mW, respectively, previously calculated. Thirteen different occlusive dressings were analyzed and interposed between the laser emitter and the power analyzer sensor, with 15 measurements made for each dressing. Statistics were provided by the analysis of variance (ANOVA), followed by Student's t-test (p < 0.05).

RESULTS:

The power transmitted ranged between 98.6% and 0%, depending on the material and wavelength. The dressings tested were BioFill, Hydrofilm, Confeel Plus 3533, Confeel 3218, DuoDERM Extra Thin, Hydrocoll, Micropore Nexcare, CIEX tape, Emplasto Sábia, CombiDERM, Band-aid, Actisorb Plus, in addition to polyvinylchloride (PVC) film, and transmitted power higher than 40% of the incident power, independently from the wavelength indicated for the association with LLLT.

CONCLUSION:

The results showed that LLLT transmission depends on the occlusive dressing material and the wavelength irradiated.

Photomed Laser Surg. 2010 Feb;28(1):115-23. doi: 10.1089/pho.2008.2445.

The effect of laser irradiation on proliferation of human breast carcinoma, melanoma, and immortalized mammary epithelial cells.

Powell K, Low P, McDonnell PA, Laakso EL, Ralph SJ.

Source

School of Medical Science, Griffith University, Gold Coast, Queensland, Australia.

 

Abstract

OBJECTIVE:

This study compared the effects of different doses (J/cm(2)) of laser phototherapy at wavelengths of either 780, 830, or 904 nm on human breast carcinoma, melanoma, and immortalized human mammary epithelial cell lines in vitro. In addition, we examined whether laser irradiation would malignantly transform the murine fibroblast NIH3T3 cell line.

BACKGROUND:

Laser phototherapy is used in the clinical treatment of breast cancer-related lymphoedema, despite limited safety information. This study contributes to systematically developing guidelines for the safe use of laser in breast cancer-related lymphoedema.

METHODS:

Human breast adenocarcinoma (MCF-7), human breast ductal carcinoma with melanomic genotypic traits (MDA-MB-435S), and immortalized human mammary epithelial (SVCT and Bre80hTERT) cell lines were irradiated with a single exposure of laser. MCF-7 cells were further irradiated with two and three exposures of each laser wavelength. Cell proliferation was assessed 24 h after irradiation.

RESULTS:

Although certain doses of laser increased MCF-7 cell proliferation, multiple exposures had either no effect or showed negative dose response relationships. No sign of malignant transformation of cells by laser phototherapy was detected under the conditions applied here.

CONCLUSION:

Before a definitive conclusion can be made regarding the safety of laser for breast cancer-related lymphoedema, further in vivo research is required.

Photomed Laser Surg. 2010 Apr;28(2):179-84. doi: 10.1089/pho.2009.2501.

Effect of low-level laser irradiation on bisphosphonate-induced osteonecrosis of the jaws: preliminary results of a prospective study.

Scoletta M, Arduino PG, Reggio L, Dalmasso P, Mozzati M.

Source

Oral Surgery Unit, Dentistry Section, Department of Clinical Physiopathology, University of Turin, Turin, Italy.

 

Abstract

OBJECTIVE:

The aim of this study was to detail the clinical efficacy of low-level laser therapy (LLLT) for the management of bisphosphonate-induced osteonecrosis of the jaws (ONJ-BP).

BACKGROUND:

ONJ-BP is the correct term, recently emerged, to describe a significant complication in a subset of patients receiving drugs such as zoledronic acid, pamidronate, and alendronate. No definitive standard of care has been set for ONJ-BP and no definitively agreed guidelines have been provided. There is currently no consensus on the correct approach to the issue.

MATERIALS AND METHODS:

The investigators studied a prospective cohort of 20 patients affected by ONJ-BP, who received biostimulation with a pulsed diode laser (GaAs). Patients were exposed to a 904-nm infrared laser (50 kHz, 28.4 J/cm(2) energy density, 40% duty cycle, spot size 0.8 cm). Outcome variables were the size of lesions, edema, visual analogue score of pain, presence of pus, fistulas, and halitosis. Preoperative results were compared with the postoperative outcome and statistically evaluated.

RESULTS:

Four weeks after LLLT, a statistically significant difference was observed for reported pain (p = 0.0001), clinical size (p = 0.0034), edema (p = 0.0005), and presence of pus and fistulas (p = 0.0078 and p = 0.03, respectively).

CONCLUSION:

This study suggests that LLLT would appear to be a promising modality of treatment for patients with ONJ-BP, providing that clinical efficacy is safe and well tolerated, especially by those patients who require conservative treatment. Of course, this needs to be addressed further in larger and randomly controlled studies in different clinical settings.

Photomed Laser Surg. 2009 Jun;27(3):461-6. doi: 10.1089/pho.2008.2290.

Assessment of cytoskeleton and endoplasmic reticulum of fibroblast cells subjected to low-level laser therapy and low-intensity pulsed ultrasound.

Oliveira DA, De Oliveira RF, Magini M, Zangaro RA, Soares CP.

Source

Laboratório de Dinâmica de Compartimento Celular, Instituto de Pesquisa e Desenvolvimento (IP&D), UNIVAP, São José dos Campos, São Paulo, Brazil.

 

Abstract

OBJECTIVE:

The aim of the present study was to compare the effect of low-level laser therapy (LLLT) and low-intensity pulsed ultrasound (LIPUS) on the cytoskeleton and endoplasmic reticulum of L929 cells. Thermal and non-thermal physical mechanisms such as LLLT and LIPUS induce clinically significant responses in cells, tissues, and organs.

MATERIALS AND METHODS:

L929 fibroblast cell cultures were irradiated with LLLT and subjected to LIPUS. Cultures irradiated with the laser (904 nm) were divided into three groups: group I, control (no irradiation); group II, irradiated at 6 J/cm(2); and group III, irradiated at 50 mJ/cm(2). Cultures subjected to ultrasound were divided into five groups: group I, control (no LIPUS); group II, LIPUS at 0.2 W/cm(2) in pulsed mode at 10% (1:9 duty cycle); group III, LIPUS at 0.6 W/cm(2) in pulsed mode at 10% (1:9 duty cycle); group IV, LIPUS at 0.2 W/cm(2) in pulsed mode at 20% (2:8 duty cycle); and group V, LIPUS at 0.6 W/cm(2) in pulsed mode at 20% (2:8 duty cycle). Each group was irradiated at 24-h intervals, with the following post-treatment incubation times: 24, 48, and 72 h. The effects of LLLT and LIPUS on the cytoskeleton and endoplasmic reticulum was evaluated by the use of fluorescent probes and with fluorescence microscopy analysis.

RESULTS:

The results following LLLT and LIPUS demonstrate that ultrasound was more effective than laser on fibroblast cell cultures when the endoplasmic reticulum was assessed, whereas there was a better distribution of the filaments of the cytoskeleton in the cells subjected to laser irradiation.

CONCLUSION:

The study demonstrated that both LLLT and LIPUS promote changes on the cellular level. However, LIPUS was more effective than LLLT at the doses used here, as assessed by fluorescence microscopy, which revealed increased reticulum activity and increased protein synthesis. However, when the organization of actin filaments was assessed, LLLT achieved a better result.

Photomed Laser Surg. 2009 Jun;27(3):513-20. doi: 10.1089/pho.2008.2281.

Comparing the effects of exercise program and low-level laser therapy with exercise program and polarized polychromatic non-coherent light (bioptron light) on the treatment of lateral elbow tendinopathy.

Stasinopoulos D, Stasinopoulos I, Pantelis M, Stasinopoulou K.

Source

Rheumatology and Rehabilitation Centre, Athens, Greece. d_stasinopoulos@yahoo.gr

 

Abstract

BACKGROUND DATA:

The use of low-level laser therapy (LLLT) and polarized polychromatic non-coherent light as supplements to an exercise program has been recommended for the management of lateral elbow tendinopathy (LET).

OBJECTIVE:

To investigate whether an exercise program supplemented with LLLT is more successful than an exercise program supplemented with polarized polychromatic non-coherent light in treating LET.

MATERIALS AND METHODS:

Patients with unilateral LET for at least 4 wk were sequentially allocated to receive either an exercise program with LLLT or an exercise program with polarized polychromatic non-coherent light. The exercise program consisted of eccentric and static stretching exercises of wrist extensors. In the LLLT group a 904-nm Ga-As laser was used in continuous mode, and the power density was 130 mW/cm(2), and the dose was 0.585 J/point. In the group receiving polarized polychromatic non-coherent light the Bioptron 2 was used to administer the dose perpendicularly to the lateral epicondyle at three points at an operating distance of 5-10 cm for 6 min at each position. The outcome measures were pain and function and were evaluated at baseline, at the end of the treatment (week 4), and 3 mo after the end of treatment (week 16).

RESULTS:

Fifty patients met the inclusion criteria. At the end of treatment there was a decline in pain and a rise in function in both groups compared with baseline (p < 0.0005 on the paired t-test). There were no significant differences in the reduction of pain and the improvement of function between the groups at the end of treatment and at the 3-mo follow-up (p > 0.0005 on the independent t-test).

CONCLUSIONS:

The results suggest that the combination of an exercise program with LLLT or polarized polychromatic non-coherent light is an adequate treatment for patients with LET. Further research to establish the relative and absolute effectiveness of such a treatment approach is needed.

Lasers Med Sci. 2010 Jan;25(1):61-5. doi: 10.1007/s10103-009-0651-x. Epub 2009 Feb 24.

The effect of 904 nm low level laser on condylar growth in rats.

Seifi M, Maghzi A, Gutknecht N, Mir M, Asna-Ashari M.

Source

Department of Orthodontics, Center for Dental Research, Shahid Beheshti University of Medical Sciences, Tehran, Iran. seifimassoud@gmail.com

 

Abstract

A growth center of the mandible that contributes to its length and height is the mandibular condyle. Proliferation of prechondroblasts, followed by synthesis of the extracellular matrix and hypertrophy of the cartilage cells, governs the major part of condylar growth. The sample consisted of 54 male rats, weighing between 60 g and 80 g, divided randomly into three groups. Group I was the control group, group II was irradiated bilaterally, and group III was irradiated on the right side. Laser irradiation (lambda = 904 nm, 2000 Hz, pulse length 200 ns and output power 4 mW) was performed, and the procedure was repeated after a 50-day interval. Two months later, the rats were killed. In a single blind manner the lengths of denuded mandibles and the lengths of mandibles on soft tissue were measured. The growth of the mandibles in the unilaterally irradiated group (P < 0.001) and the bilaterally irradiated group (P < 0.05) was significantly more than that in the control group. There was no significant difference between right and left condylar growth in the bilaterally irradiated group (P = 0.3). Soft tissue analysis also verified these results (P < 0.001). Histomorphometric results also revealed a significant difference between laser-irradiated groups and the control group (P < 0.01). We concluded that particular laser irradiation with the chosen parameters can stimulate condylar growth and subsequently cause mandibular advancement. These findings might be clinically relevant, indicating that low level laser irradiation can be used for further improvement of mandibular retrognathism.

Photomed Laser Surg. 2008 Oct;26(5):451-3. doi: 10.1089/pho.2007.2218.

Intracellular ATP level increases in lymphocytes irradiated with infrared laser light of wavelength 904 nm.

Benedicenti S, Pepe IM, Angiero F, Benedicenti A.

Source

Department of Medical Science, Dentistry, and Biophysics, University of Genoa, Milan, Italy. stefano.benediceneti@tiscali.it

 

Abstract

OBJECTIVE:

Red and near-infrared laser irradiation is reported to have a range of biological effects on cultured cells and different tissues, leading to the hypothesis that laser light can affect energy metabolism. Increased adenosine triphosphate (ATP) synthesis has been reported in cultured cells and rat brain tissue after irradiation at 632.8 nm and 830 nm, respectively. This study investigated whether diode pulsed laser irradiation enhances ATP production in lymphocytes.

MATERIALS AND METHODS:

Aliquots (500 microL) of an extract of cultured lymphocytes of the Molt-4 cell line were irradiated with diode laser light (lambda = 904 nm, pulsed mode, 6 kHz frequency) with an average emission power of 10 mW for 60 min. A Spectra Physics M404 power meter was used to measure light intensity. Controls were treated similarly but not irradiated. The amount of ATP was measured by the luciferin-luciferase bioluminescent assay.

RESULTS:

The amount of ATP in irradiated cell cultures was 10.79 +/- 0.15 microg/L (SD; n = 10), and in non-irradiated cell cultures it was 8.81 +/- 0.13 microg/L (SD; n = 10). The average percentage increase of irradiated versus control cell cultures was about 22.4% +/- 0.56% SD (p < 0.001).

CONCLUSION:

This significant increase is probably due to laser irradiation; it cannot be attributed to any thermal effect, as the temperature during irradiation was maintained at 37.0 degrees +/- 0.5 degrees C. Thus the therapeutic effects of the biostimulating power of this type of laser are identified and its indications may be expanded.

 

 

 

BMC Musculoskelet Disord. 2008 May 29;9:75. doi: 10.1186/1471-2474-9-75.

A systematic review with procedural assessments and meta-analysis of low level laser therapy in lateral elbow tendinopathy (tennis elbow).

Bjordal JM, Lopes-Martins RA, Joensen J, Couppe C, Ljunggren AE, Stergioulas A, Johnson MI.

Source

Institute of Physiotherapy, Faculty of Health and Social Sciences, Bergen University College, Moellendalsvn, 6, 5009 Bergen, Norway. jmb@hib.no

 

Abstract

BACKGROUND:

Recent reviews have indicated that low level level laser therapy (LLLT) is ineffective in lateral elbow tendinopathy (LET) without assessing validity of treatment procedures and doses or the influence of prior steroid injections.

METHODS:

Systematic review with meta-analysis, with primary outcome measures of pain relief and/or global improvement and subgroup analyses of methodological quality, wavelengths and treatment procedures.

RESULTS:

18 randomised placebo-controlled trials (RCTs) were identified with 13 RCTs (730 patients) meeting the criteria for meta-analysis. 12 RCTs satisfied half or more of the methodological criteria. Publication bias was detected by Egger's graphical test, which showed a negative direction of bias. Ten of the trials included patients with poor prognosis caused by failed steroid injections or other treatment failures, or long symptom duration or severe baseline pain. The weighted mean difference (WMD) for pain relief was 10.2 mm [95% CI: 3.0 to 17.5] and the RR for global improvement was 1.36 [1.16 to 1.60]. Trials which targeted acupuncture points reported negative results, as did trials with wavelengths 820, 830 and 1064 nm. In a subgroup of five trials with 904 nm lasers and one trial with 632 nm wavelength where the lateral elbow tendon insertions were directly irradiated, WMD for pain relief was 17.2 mm [95% CI: 8.5 to 25.9] and 14.0 mm [95% CI: 7.4 to 20.6] respectively, while RR for global pain improvement was only reported for 904 nm at 1.53 [95% CI: 1.28 to 1.83]. LLLT doses in this subgroup ranged between 0.5 and 7.2 Joules. Secondary outcome measures of painfree grip strength, pain pressure threshold, sick leave and follow-up data from 3 to 8 weeks after the end of treatment, showed consistently significant results in favour of the same LLLT subgroup (p < 0.02). No serious side-effects were reported.

CONCLUSION:

LLLT administered with optimal doses of 904 nm and possibly 632 nm wavelengths directly to the lateral elbow tendon insertions, seem to offer short-term pain relief and less disability in LET, both alone and in conjunction with an exercise regimen. This finding contradicts the conclusions of previous reviews which failed to assess treatment procedures, wavelengths and optimal doses.

Photomed Laser Surg. 2007 Aug;25(4):245-9.

Low-level laser therapy (GaAs lambda = 904 nm) reduces inflammatory cell migration in mice with lipopolysaccharide-induced peritonitis.

Correa F, Lopes Martins RA, Correa JC, Iversen VV, Joenson J, Bjordal JM.

Source

University Nove Julho, São Paulo, Brazil.

 

Abstract

OBJECTIVE:

This study was designed to study the effect of an infrared low-level laser (GaAs lambda = 904 nm, 4 mW) on inflammatory cell migration in lipopolysaccharide (LPS)-induced peritonitis in mice.

BACKGROUND DATA:

It has been suggested that red wavelengths of low-level laser therapy (LLLT) can exert anti-inflammatory effects, but little is known about the anti-inflammatory effects of infrared lasers. Peritonitis is a potentially life-threatening inflammatory condition that may be suitable for studying anti-inflammatory effects of infrared lasers.

METHODS:

Sixty male mice were randomly divided into five groups, and one group was given an intraperitoneal sterile saline injection. In the remaining four groups, peritonitis was induced by an intraperitoneal LPS injection. Animals in three of the LPS groups were irradiated at a single point over the peritoneum with doses of 3 J/cm(2), 7.5 J/cm(2), and 15 J/cm(2), respectively. The fourth group injected with LPS was an LPS-control group.

RESULTS:

At 6 hours after injection the groups irradiated with doses of 3 J/cm(2) and 7.5 J/cm(2) had a reduced number of neutrophil cells in the peritoneal cavity compared with the LPS-control group, and there were significant differences between the number of neutrophils in the peritoneal cavity between the LPS-control group and groups irradiated with doses of 3 J/cm(2) (-42%) and 7.5 J/cm(2) (-70%). In the group irradiated with 15 J/cm(2), neutrophil cell counts were lower than, but not significantly different from, LPS controls (-38%; p = 0.07). At 24 hours after injection, both neutrophil and total leukocyte cell counts were lower in all the irradiated groups than in the LPS controls. The 3-J/cm(2) exposure group showed the best results at 24 hours, with reductions of 77% in neutrophil and 49% in leukocyte counts.

CONCLUSION:

Low-level laser therapy (904 nm) can reduce inflammatory cell migration in mice with LPS-induced peritonitis in a dose-dependent manner.

Photomed Laser Surg. 2007 Apr;25(2):65-71.

Effects of 904-nm low-level laser therapy in the management of lateral epicondylitis: a randomized controlled trial.

Lam LK, Cheing GL.

Source

Physiotherapy Department, Queen Elizabeth Hospital, Hong Kong.

 

Abstract

OBJECTIVE:

The aim of this study was to evaluate the effectiveness of 904-nm low-level laser therapy (LLLT) in the management of lateral epicondylitis.

BACKGROUND DATA:

Lateral epicondylitis is characterized by pain and tenderness over the lateral elbow, which may also result in reduction in grip strength and impairment in physical function. LLLT has been shown effective in its therapeutic effects in tissue healing and pain control.

METHODS:

Thirty-nine patients with lateral epicondylitis were randomly assigned to receive either active laser with an energy dose of 0.275 J per tender point (laser group) or sham irradiation (placebo group) for a total of nine sessions. The outcome measures were mechanical pain threshold, maximum grip strength, level of pain at maximum grip strength as measured by the Visual Analogue Scale (VAS) and the subjective rating of physical function with Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire.

RESULTS:

Significantly greater improvements were shown in all outcome measures with the laser group than with the placebo group (p < 0.0125), except in the two subsections of DASH.

CONCLUSION:

This study revealed that LLLT in addition to exercise is effective in relieving pain, and in improving the grip strength and subjective rating of physical function of patients with lateral epicondylitis.

J Photochem Photobiol B. 2007 Mar 1;86(3):279-82. Epub 2006 Nov 20.

Evaluation of mitochondrial respiratory chain activity in wound healing by low-level laser therapy.

Silveira PC, Streck EL, Pinho RA.

Source

Laboratório de Fisiologia e Bioquímica do Exercício, Universidade do Extremo Sul Catarinense, 88806-000 Criciúma, SC, Brazil.

 

Abstract

Laser therapy is used in many biomedical sciences to promote tissue regeneration. Many studies involving low-level laser therapy have shown that the healing process is enhanced by such therapy. In this work, we evaluated mitochondrial respiratory chain complexes II and IV and succinate dehydrogenase activities in wounds after irradiation with low-level laser. The animals were divided into two groups: group 1, the animals had no local nor systemic treatment and were considered as control wounds; group 2, the wounds were treated immediately after they were made and every day after with a low-level laser (AsGa, wavelength of 904 nm) for 10 days. The results showed that low-level laser therapy improved wound healing. Besides, our results showed that low-level laser therapy significantly increased the activities of complexes II and IV but did not affect succinate dehydrogenase activity. These findings are in accordance to other works, where cytochrome c oxidase (complex IV) seems to be activated by low-level laser therapy. Besides, we showed, for the first time, that complex II activity was also activated. More studies are being carried out in order to evaluate other mitochondrial enzymes activities after different doses and irradiation time of low-level laser.

J Cosmet Laser Ther. 2006 Apr;8(1):27-30.

Use of the pulsed infrared diode laser (904 nm) in the treatment of alopecia areata.

Waiz M, Saleh AZ, Hayani R, Jubory SO.

Source

Department of Dermatology and Venereology, Baghdad Teaching Hospital, Baghdad, Iraq. raafahayani@yahoo.com

 

Abstract

BACKGROUND:

Alopecia areata is a rapid and complete loss of hair in one or several patches, usually on the scalp, affecting both males and females equally. It is thought to be an autoimmune disease which is treated with different modalities with variable success. Laser treatment of different wavelengths has been used in the management of this problem.

OBJECTIVE:

To study the effect of the pulsed infrared diode laser (904 nm) in the treatment of alopecia areata.Methods. Sixteen patients with 34 resistant patches that had not responded to different treatment modalities for alopecia areata were enrolled in this study. In patients with multiple patches, one patch was left as a control for comparison. Patients were treated on a four-session basis, once a week, with a pulsed diode laser (904 nm) at a pulse rate of 40/s. A photograph was taken of each patient before and after treatment.

RESULTS:

The treated patients were 11 males (68.75%) and five females (31.25%). Their ages ranged between 4 and 50 years with a mean of 26.6+/-SD of +/-13.8, and the durations of their disease were between 12 months and 6 years with a mean of 13.43+/-SD of +/-18.34. Regrowth of hair was observed in 32 patches (94%), while only two patches (6%) failed to show any response. No regrowth of hair was observed in the control patches. The regrowth of hair appeared as terminal hair with its original color in 29 patches (90.6%), while three patches (9.4%) appeared as a white villous hair. In patients who showed response, the response was detected as early as 1 week after the first session in 24 patches (75%), while eight patients (25%) started to show response from the second session.

CONCLUSION:

The pulsed infrared diode laser is an effective mode of therapy with a high success rate for resistant patches of alopecia areata.

Br J Sports Med. 2006 Jan;40(1):76-80; discussion 76-80.

A randomised, placebo controlled trial of low level laser therapy for activated Achilles tendinitis with microdialysis measurement of peritendinous prostaglandin E2 concentrations.

Bjordal JM, Lopes-Martins RA, Iversen VV.

Source

Physiotherapy Science, University of Bergen, Bergen, Norway. jmbjor@broadpark.no

 

Abstract

BACKGROUND:

Low level laser therapy (LLLT) has gained increasing popularity in the management of tendinopathy and arthritis. Results from in vitro and in vivo studies have suggested that inflammatory modulation is one of several possible biological mechanisms of LLLT action.

OBJECTIVE:

To investigate in situ if LLLT has an anti-inflammatory effect on activated tendinitis of the human Achilles tendon.

SUBJECTS:

Seven patients with bilateral Achilles tendinitis (14 tendons) who had aggravated symptoms produced by pain inducing activity immediately before the study.

METHOD:

Infrared (904 nm wavelength) LLLT (5.4 J per point, power density 20 mW/cm2) and placebo LLLT (0 J) were administered to both Achilles tendons in random blinded order.

RESULTS:

Ultrasonography Doppler measurements at baseline showed minor inflammation through increased intratendinous blood flow in all 14 tendons and measurable resistive index in eight tendons of 0.91 (95% confidence interval 0.87 to 0.95). Prostaglandin E2 concentrations were significantly reduced 75, 90, and 105 minutes after active LLLT compared with concentrations before treatment (p = 0.026) and after placebo LLLT (p = 0.009). Pressure pain threshold had increased significantly (p = 0.012) after active LLLT compared with placebo LLLT: the mean difference in the change between the groups was 0.40 kg/cm2 (95% confidence interval 0.10 to 0.70).

CONCLUSION:

LLLT at a dose of 5.4 J per point can reduce inflammation and pain in activated Achilles tendinitis. LLLT may therefore have potential in the management of diseases with an inflammatory component.

Lasers Surg Med. 2005 Oct;37(4):293-300.

Low-level laser therapy (LLLT) prevents oxidative stress and reduces fibrosis in rat traumatized Achilles tendon.

Fillipin LI, Mauriz JL, Vedovelli K, Moreira AJ, Zettler CG, Lech O, Marroni NP, González-Gallego J.

Source

Department of Physiology, Universidade Federal de Rio Grande do Sul, Brazil.

 

Abstract

BACKGROUND AND OBJECTIVES:

The present study investigated the effects of low-level laser therapy (LLLT) on oxidative stress and fibrosis in an experimental model of Achilles tendon injury induced by a single impact trauma.

STUDY DESIGN/MATERIALS AND METHODS:

Male Wistar rats were randomly divided into four groups (n = 8): control, trauma, trauma+LLLT for 14 days, and trauma+LLLT for 21 days. Achilles tendon traumatism was produced by dropping down a load with an impact kinetic energy of 0.544 J. A low level Ga-As laser was applied with a 904 nm wavelength, 45 mW average power, 5 J/cm(2) dosage, for 35 seconds duration, continuously. Studies were carried out at day 21.

RESULTS:

Histology showed a loss of normal architecture, with inflammatory reaction, angiogenesis, vasodilatation, and extracellular matrix formation after trauma. This was accompanied by a significant increase in collagen concentration when compared the control group. Oxidative stress, measured by the concentration of thiobarbituric acid reactive substances and hydroperoxyde-initiated chemiluminiscence, was also significantly increased in the trauma group. Administration of LLLT for 14 or 21 days markedly alleviated histological abnormalities reduced collagen concentration and prevented oxidative stress. Superoxide dismutase activity was significantly increased by LLLT treatment over control values.

CONCLUSION:

LLLT by Ga-As laser reduces histological abnormalities, collagen concentration, and oxidative stress in an experimental model of Achilles tendon injury. Reduction of fibrosis could be mediated by the beneficial effects on the oxidant/antioxidant balance.

 

 

Photomed Laser Surg. 2005 Jun;23(3):289-94.

Low-level laser therapy accelerates collateral circulation and enhances microcirculation.

Ihsan FR.

Source

Department of Anatomy, AL-Kindy College of Medicine, University of Baghdad, Iraq.

 

Abstract

OBJECTIVE:

To evaluate the efficacy of low-level laser therapy (LLLT) on collateral circulation and microcirculation if a blood vessel is occluded.

BACKGROUND DATA:

Investigators have attempted prostaglandin and ultrasound therapy to promote improvements in the vascular bed of deprived tissue after an injury, which may lead to occlusion of the blood vessels.

MATERIALS AND METHODS:

Thirty-four adult rabbits were used in this study, two of them considered 0-h reading group, while the rest were divided into two equal groups, with 16 rabbits each: control and those treated with LLLT. Each rabbit underwent two surgical operations; the medial aspect of each thigh was slit, the skin incised and the femoral artery exposed and ligated. The site of the operation in the treated group was irradiated directly following the operation and for 3 d after, one session daily for 10 min/session. The laser system used was a gallium-aluminum-arsenide (Ga-Al-As) diode laser with a wavelength of 904 nm and power of 10 mW. Blood samples collected from the femoral artery above the site of the ligation were sent for examination with high-performance liquid chromatography (HPLC) to determine the levels of adenosine, growth hormone (GH) and fibroblast growth factor (FGF). Tissue specimens collected from the site of the operation, consisting of the artery and its surrounding muscle fibers, were sent for histopathological examination to determine the fiber/capillary (F/C) ratio and capillary diameter. Blood samples and tissue specimens were collected at 4, 8, 12, 16, 20, 24, 48 and 72 h postoperatively from the animals of both groups, control and treated.

RESULTS:

Rapid increases in the level of adenosine, GH, and FGF occurred. The F/C ratio and capillary diameter peaked at 12-16 h; their levels declined gradually, reaching normal values 72 h after irradiation in the treated group. Numerous collateral blood vessels proliferated the area, with marked increases in the diameters of the original blood vessels.

CONCLUSIONS:

The results indicated that LLLT accelerated collateral circulation and enhanced microcirculation and seemed to be unique in the normalization of the functional features of the injured area, which could lead to occlusion of the regional blood vessels.

 

 

Photomed Laser Surg. 2005 Feb;23(1):70-3.

Low-level laser therapy (LLLT) efficacy in post-operative wounds.

Herascu N, Velciu B, Calin M, Savastru D, Talianu C.

Source

National Institute of Research and Development for Optoelectronics INOE 2000, 1 Atomistilor St., PO Box MG5, 077125, Magurele-Bucharest, Romania. herescu@inoe.inoe.ro

 

Abstract

OBJECTIVE:

The aim of this paper was to investigate the efficacy of low-level laser radiation (LLLR) with wavelength of 904 nm on the stimulation of the healing process of postoperative aseptic wounds (early scar).

BACKGROUND DATA:

Low-level laser therapy (LLLT) has been increasingly used to treat many disorders, including wounds. However, despite such increased clinical usage, there is still controversy regarding the efficacy of this wound treatment in curent clinical practice.

METHODS:

LLLT has been used to treat cutting plague in the right instep and on the left foot. Both resulted from sutured wounds. The clinical evaluation by semiquantitative methods is presented.

RESULTS:

Clinical evaluation showed that the healing process of these postoperatively treated wounds has occurred and that the functional recovery of the patients (i.e., return to their ordinary life) was faster than without treatment.

CONCLUSION:

LLLR with wavelength of 904 nm to stimulate postoperative aseptic wounds (early scar) is efficient in both cases of cutting plague.

Photomed Laser Surg. 2004 Jun;22(3):199-204.

A histologic assessment of the influence of low-intensity laser therapy on wound healing in steroid-treated animals.

Pessoa ES, Melhado RM, Theodoro LH, Garcia VG.

Source

Dental School of Marilia, University of Marilia, Marilia, SP, Brazil.

 

Abstract

OBJECTIVE:

The aim of the present study was to evaluate the effect of low-intensity laser therapy on the wound healing process treated with steroid.

BACKGROUND DATA:

Various biological effects have been associated with low-level laser therapy (LLLT).

MATERIALS AND METHODS:

Forty-eight rats were used, and after execution of a wound on the dorsal region of each animal, they were divided into 4 groups (n = 12), receiving the following treatments: G1 (control), wounds and animals received no treatment; G2, wounds were treated with LLLT; G3, animals received an intraperitoneal injection of steroid dosage (2 mg/kg of body weight); G4, animals received steroid and wounds were treated with LLLT. The laser emission device used was a GaAIAs (904 nm), in a contact mode, with 2.75 mW gated with 2.900 Hz during 120 sec (33 J/cm(2)). After the period of 3, 7, and 14 days, the animals were sacrificed and the parts sent to histological processing and dyed using hematoxylin and eosin (HE) and Masson trichromium (MT) techniques.

RESULTS:

The results have shown that the wounds treated with steroid had a delay in healing, while LLLT accelerated the wound healing process. Also, wounds treated with laser in the animals treated with steroid presented a differentiated healing process with a larger collagen deposition and also a decrease in both the inflammatory infiltrated and the delay on the wound healing process.

CONCLUSION:

LLLT accelerated healing, caused by the steroid, acting as a biostimulative coadjutant agent, balancing the undesirable effects of cortisone on the tissue healing process.

Lasers Surg Med. 2004;35(1):84-9.

Comparison of the effects of laser, ultrasound, and combined laser + ultrasound treatments in experimental tendon healing.

Demir H, Menku P, Kirnap M, Calis M, Ikizceli I.

Source

Erciyes University Medical Faculty, Department of Physical Medicine & Rehabilitation, Kayseri, Turkey. demirh@erciyes.edu.tr

 

Abstract

BACKGROUND AND OBJECTIVE:

Therapeutic ultrasound (US) and laser (L) treatments accelerate and facilitate wound healing, and also have beneficial effects on tendon healing. This randomized control study was designed to evaluate the effects of low-intensity US and low-level laser therapy (LLLT) on tendon healing in rats.

STUDY DESIGN/MATERIALS AND METHODS:

Eighty-four healthy male Swiss-Albino rats were divided into three groups consisting of 28 rats, the left Achilles tendons were used as treatment and the right Achilles tendons as controls. The right and left Achilles tendons of rats were traumatized longitudinally. The treatment was started on postinjury day one. We applied the treatment protocols including low-intensity US treatment in Group I (US Group), Sham US in Group II (SUS Group), LLLT in Group III (L Group), Sham L in Group IV (SL Group), US and LLLT in Group V (US + L Group), and Sham US and Sham L in Group VI (SUS + SL Group). The US treatment was applied with a power of 0.5 W/cm2, a frequency of 1 MHz, continuously, 5 minutes daily. A low-level Ga-As laser was applied with a 904 nm wavelength, 6 mW average power, 1 J/ cm2 dosage, 16 Hz frequency, for 1 minute duration, continuously. In the control groups, the similar procedures as in the corresponding treatment groups were applied with no current (Sham method). The treatment duration was planned for 9 days (sessions) in all groups, except the rats used for biochemical evaluation on the 4th day of treatment, which were treated for 4 days. We measured the levels of the tissue hydroxyproline for biochemical evaluation on the 4th, 10th, and 21st days following the beginning of treatment and the tendon breaking strength on the 21st day following the beginning of treatment for biomechanical evaluation. Seven rats in each group were killed on the 4th, 10th, and 21st days for biochemical evaluation and on the 21st day for biomechanical evaluation.

RESULTS:

The hydroxyproline levels were found to be significantly increased in the treatment groups on the 10th and 21st days compared to their control groups (P < 0.05). In comparison of the treatment groups on the 4th, 10th, and 21st days of the treatment, the levels of tissue hydroxyproline were found to be more increased in combined US+L Group compared with US Group and L Group, but the difference was not significant (P > 0.05). In comparison of the tendon breaking strengths, it was found as significantly increased in the treatment groups compared with their control groups (P < 0.05), although there was no significant difference between the treatment groups.

CONCLUSIONS:

Although US, L, and combined US + L treatments increased tendon healing biochemically and biomechanically more than the control groups, no statistically significant difference was found between them. Also we did not find significantly more cumulative positive effects of combined treatment. As a result, both of these physical modalities can be used successfully in the treatment of tendon healing.

Photodermatol Photoimmunol Photomed. 2003 Aug;19(4):203-12.

Immunomodulatory effects of low-intensity near-infrared laser irradiation on contact hypersensitivity reaction.

Kandolf-Sekulovic L, Kataranovski M, Pavlovic MD.

Source

Department of Dermatology and Institute for Medical Research, Military Medical Academy, Belgrade, Serbia and Montenegro.

 

Abstract

BACKGROUND/PURPOSE:

Contact hypersensitivity (CHS) reaction is a useful model for studying the skin immune system and inflammatory reactions in the skin. In this study, an experimental model of CHS reaction was employed to assess immunomodulatory effects of near-infrared (near-IR) low-intensity laser (LIL) irradiation, which is used as adjuvant therapy in dermatology, physical medicine, rheumatology, etc., because of its declared anti-inflammatory, biostimulative and analgesic effects.

METHODS:

The effects of near-IR LIL irradiation (lambda=904 nm, irradiance 60 mW/cm2, fluence 3.6 J/cm2) on CHS reaction to 1-chloro-2,4-dinitrochlorobenzene (DNCB) in Albino Oxford rats were examined by irradiating experimental groups of animals before the induction phase of CHS reaction, while nonirradiated animals and animals that received vehicle instead of hapten served as controls. Ear-swelling assay, histopathological examination of H&E preparations of ear skin, computer-assisted image analysis of dermal infiltrate, ear skin organ culture with the determination of cutaneous production of tumour necrosis factor-alpha (by ELISA assay) and nitric oxide (by Griess' assay) were used for measuring the effects of LIL in the elicitation phase of CHS reaction. Cellularity, dendritic cell content, flow cytometry and proliferation assays (spontaneous and in the presence of IL-2 and concanavalin A) of the draining lymph node cells (DLNC) were performed for the assessment of LIL irradiation effects in the induction phase.

RESULTS:

In the irradiated group of animals, ear swelling was significantly diminished compared to control animals (101+/-11.5% vs. 58+/-11.6%, P<0.01). This was accompanied by a highly significant decrease in the density of dermal infiltrate (22+/-0.81 vs. 14.2+/-1.75 cells per unit area, P<0.01) and a significant decrease in nitrite levels in the medium conditioned by organ-cultured ear skin (17.63+/-1.91 vs. 3.16+/-1.69 microM NaNO2; P<0.01), while TNF-alpha concentration was not changed. Cellularity and dendritic cell content in DLNC population, as well as the expression of TCR-alpha, CD4, CD8 and CD25, were not changed between irradiated and nonirradiated animals. Proliferation rates of DLNC cultured for 72 h were significantly lower in irradiated animals (17.3+/-4.1 vs. 13.9+/-0.9 x 103 c.p.m.; P<0.01). In cultures of DLNC with added rIL-2 or 0.5 microg/ml of concanavalin A, proliferation rates were also significantly decreased in irradiated animals (34.7+/-3.5 vs. 31.2+/-2. c.p.m. in IL-2-supplemented culture, P<0.01; 70.9+/-6.4 vs. 58.3+/-9.1 x 103 c.p.m. in concanavalin A-supplemented culture, P<0.01). However, this effect was overcome in the presence of the higher concentration of concanavalin A (2.5 microg/ml) (nonirradiated 38.7+/-3.1, irradiated 123.1+/-7.3 x 103 c.p.m., P<0.01).

CONCLUSION:

LIL irradiation showed a systemic immunomodulatory effect on CHS reaction to DNCB in rats. Decreased ear swelling observed in the elicitation phase was associated with diminished proliferative responses of the DLNC in the induction phase of CHS reaction. Further experimental work is needed to examine the possible mechanisms of these effects.

Clin Cancer Res. 2002 Oct;8(10):3082-91.

Phase I trial of an infrared pulsed laser device in patients with advanced neoplasias.

Santana-Blank LA, Rodríguez-Santana E, Vargas F, Reyes H, Fernández-Andrade P, Rukos S, Santana-Rodríguez KE.

Source

Fundalas, Foundation for Interdisciplinary Research and Development, Caracas, 1020, Venezuela.

 

Abstract

PURPOSE:

The objective of this study was to evaluate the toxicity/radiant exposure/time relationship of an infrared pulsed laser device (IPLD) treatment in patients with advanced neoplasias. Karnofsky performance status (KPS), Spitzer quality of life index (QLI), and potential antitumor activity, if any, were also assessed. Experimental Design: Seventeen patients (n = 17) received a daily IPLD radiant exposure of 4.5 x 10(5) J/m(2) (904 nm pulsed at 3 MHz) under a one-dose schedule and procedure design. Toxicity was evaluated under the parameters of the WHO; indirect toxic ocular effects were also monitored. KPS and QLI measurements were conducted before treatment and at six 3-months intervals. Scores for the seventh interval are the last available (range, 19-39 months). For statistical purposes, patients were classified into group 1, those alive at the end of the study, and group 2, those who had died.

RESULTS:

Dose-limiting toxicity was not observed. Five patients (n = 5) reported occasional headaches (grade 2), and four (n = 4) referred local pain (grade 2). In group 1 (n = 7), statistically significant increases in KPS and QLI were observed in all of the follow-up intervals compared with pretreatment values. One patient had a complete response, 1 a partial response, 4 stable diseases > or =12 months, and 1 progressive disease. In group 2 (n = 10), statistically significant increases in QLI were observed during the first two intervals. Eight patients had stable disease > or =6 months and 2 had uninterrupted progressive diseases.

CONCLUSIONS:

The IPLD treatment studied is safe for clinical use and may have potential effects on KPS, QLI, and antitumor activity in patients with advanced neoplasias.

Lasers Med Sci. 2002;17(3):187-97.

Ultrastructural changes in thyroid perifollicular capillaries during normal postnatal development and after infrared laser radiation.

Vidal L, Ortíz M, Pérez de Vargas I.

Source

Department of Normal and Pathological Morphology, Faculty of Medicine, University of Málaga, Málaga, Spain. lvidal@uma.es

 

Abstract

This study was carried out on the perifollicular capillaries of the thyroid gland during postnatal (PN) development in normal conditions and after irradiation (46.8 J/cm(2)) with an infrared (IR) laser (904 nm). This was done using 11-, 21-, and 35-day-old Wistar rats. The changes in the capillaries were determined using quantitative methods as well as electron microscopy. During normal PN development the most relevant changes were an increase in the size of the capillaries, especially the lumen, thinning of the endothelium and an increase in the size of pinocytotic vesicles. Our results suggest that during PN development, the capillaries undergo some growth and maturation processes until they reach the optimal morphological conditions for their exchange functions. IR laser irradiation seems to stimulate the growth and maturation of endothelial cells in the youngest rats, while in older ones it causes irregular thickening of the endothelium and a reduction of the capillary lumen. These changes could be a sign of functional alterations in follicular cells caused by exposure to IR laser.

J Clin Laser Med Surg. 2000 Apr;18(2):67-73.

Wound healing of animal and human body sport and traffic accident injuries using low-level laser therapy treatment: a randomized clinical study of seventy-four patients with control group.

Simunovic Z, Ivankovich AD, Depolo A.

Source

Department of Anesthesiology, La Caritá Medical Center, Laser Center, Locarno, Switzerland. info@lasermedico.ch

 

Abstract

BACKGROUND AND OBJECTIVE:

The main objective of current animal and clinical studies was to assess the efficacy of low level laser therapy (LLLT) on wound healing in rabbits and humans.

STUDY DESIGN/MATERIALS AND METHODS:

In the initial part of our research we conducted a randomized controlled animal study, where we evaluated the effects of laser irradiation on the healing of surgical wounds on rabbits. The manner of the application of LLLT on the human body are analogous to those of similar physiologic structure in animal tissue, therefore, this study was continued on humans. Clinical study was performed on 74 patients with injuries to the following anatomic locations: ankle and knee, bilaterally, Achilles tendon; epicondylus; shoulder; wrist; interphalangeal joints of hands, unilaterally. All patients had had surgical procedure prior to LLLT. Two types of laser devices were used: infrared diode laser (GaAlAs) 830 nm continuous wave for treatment of trigger points (TPs) and HeNe 632.8 nm combined with diode laser 904-nm pulsed wave for scanning procedure. Both were applied as monotherapy during current clinical study. The results were observed and measured according to the following clinical parameters: redness, heat, pain, swelling and loss of function, and finally postponed to statistical analysis via chi2 test.

RESULTS:

After comparing the healing process between two groups of patients, we obtained the following results: wound healing was significantly accelerated (25%-35%) in the group of patients treated with LLLT. Pain relief and functional recovery of patients treated with LLLT were significantly improved comparing to untreated patients.

CONCLUSION:

In addition to accelerated wound healing, the main advantages of LLLT for postoperative sport- and traffic-related injuries include prevention of side effects of drugs, significantly accelerated functional recovery, earlier return to work, training and sport competition compared to the control group of patients, and cost benefit.

Lasers Surg Med. 2000;27(5):411-9.

Short-term bioeffects of an infrared pulsed laser device on burned rat skin monitored by transverse relaxation times (NMR).

Santana-Blank LA, Rodríguez-Santana E, Scott-Algara D, Hunger M, Santana-Rodríguez KE, Orellana R.

Source

Foundation for Interdisciplinary Research and Development Fundalas, Caracas, Venezuela. fundalas@hotmail.com

 

Abstract

BACKGROUND AND OBJECTIVE:

The aim of this study was to determine whether the application of an infrared pulsed laser device (IPLD) on the burned skin of rats induced significant changes in the water dynamics of the burned tissues as measured by nuclear magnetic resonance (NMR) at a proton frequency of 90 MHz by using transverse relaxation times (T2, I/T2).

STUDY DESIGN/MATERIALS AND METHODS:

Seven groups (GI-GVII), each consisting of four albino rats (Sprague-Dawley), of 12-14 weeks of age were used in the experiment. Rats in GI-GVI were anesthetized and burned with a hot tip. GI, GIII, GV were not irradiated. GII, GIV, GVI were irradiated at 0 hours; 0 and 24 hours; and 0, 24, and 48 hours, respectively. Rats in GVII served as controls and were neither burned nor irradiated. Samples from all groups were obtained and monitored by NMR by using transverse relaxation times (T2 and 1/T2). An unpaired Student's t-test and a one-way analysis of variance (ANOVA I) were preformed on the mean values obtained (T2, 1/T2). The statistical design was chosen to give a 95% power of contrast 1-beta (1/T2). The modulated beam of the IPLD used is composed of two superposed waves; a carrier wave (3 MHz), and a drive force wave in the near infrared (904 nm, f = 1014 Hz). A dose of 1.5 x 10(3) J/M2 per session was applied by placing the IPLD directly over the burned tissue by using a top-hat distribution.

RESULTS:

The results of a t-test on the T2 and 1/T2 values did not show statistically significant differences at 0 and 24 hours between the irradiated groups, the nonirradiated groups, and the nonburned nonirradiated (control) group. Nonetheless, at 48 hours after the burn, we found a statistically significant difference in the 1/T2 values for the irradiated specimens compared with the nonirradiated specimens and the control group. Furthermore, the variance of the 1/T2 values as a function of time showed a tendency to decrease significantly only for the irradiated specimens.

CONCLUSION:

These findings show possible effects on the water dynamics of burned rat tissue in a short term as a result of the IPLD's application.0

Lasers Surg Med. 1999;24(4):285-95.

Effect of laser irradiation on the growth and development of fetal mouse limbs in an in vitro model.

Thawer HA, Houghton PE.

Source

School of Physical Therapy, Faculty of Health Sciences, University of Western Ontario, London, Canada.

 

Abstract

BACKGROUND AND OBJECTIVE:

The purpose of the present study was to examine the effects of laser irradiation on the growth and development of fetal limb tissue.

STUDY DESIGN/MATERIALS AND METHODS:

Day 14 fetal mouse limbs (n=168) were irradiated with gallium arsenide laser (904 nm, spot size=0.002 cm2, pulse duration=200 nanoseconds, peak power=30 mW) for 1 minute each day while being maintained in an organ culture system for 3 or 5 days at the following energy densities [O (control), 0.23, 1.37, 2.75, 3.66, and 4.58 J/cm2].

RESULTS:

Computer image analysis of photographic images showed that there was a significant inhibition (P < 0.05) of new tissue growth after administration of lower energy densities of laser (0.23 and 1.37 J/cm2). These low-energy densities of laser irradiation also produced increased dermal cell number and collagen fiber thickness as assessed with qualitative histologic analysis of limb development by a blinded observer. Quantitative analysis of collagen distribution by color densitometric analysis of tissue sections stained with sirus red and fast green confirmed that there was a significantly greater (P < 0.05) amount of collagen present in the dermis of limbs treated with low-energy densities of laser (0.23 and 1.37 J/cm2).

CONCLUSIONS:

Laser irradiation directly affected the growth and development of day 14 fetal mouse limbs in an organ culture system.

J Clin Laser Med Surg. 1999 Feb;17(1):29-33.

Low power laser therapy and analgesic action.

Tam G.

Source

tam.g@agemont.it

 

Abstract

OBJECTIVE:

The semiconductor or laser diode (GaAs, 904 nm) is the most appropriate choice in pain reduction therapy.

SUMMARY BACKGROUND DATA:

Low-power density laser acts on the prostaglandin (PG) synthesis, increasing the change of PGG2 and PGH2 into PG12 (also called prostacyclin, or epoprostenol). The last is the main product of the arachidonic acid into the endothelial cells and into the smooth muscular cells of vessel walls, that have a vasodilating and anti-inflammatory action.

METHODS:

Treatment was performed on 372 patients (206 women and 166 men) during the period between May 1987 and January 1997. The patients, whose ages ranged from 25 to 70 years, with a mean age of 45 years, suffered from rheumatic, degenerative, and traumatic pathologies as well as cutaneous ulcers. The majority of patients had been seen by orthopedists and rheumatologists and had undergone x-ray examination. All patients had received drug-based treatment and/or physiotherapy with poor results; 5 patients had also been irradiated with He:Ne and CO2 lasers. Two-thirds were experiencing acute symptomatic pain, while the others suffered long-term pathology with recurrent crises. We used a pulsed diode laser, GaAs 904 nm wavelength once per day for 5 consecutive days, followed by a 2-day interval. The average number of applications was 12. We irradiated the trigger points, access points to the joint, and striated muscles adjacent to relevant nerve roots.

RESULTS:

We achieved very good results, especially in cases of symptomatic osteoarthritis of the cervical vertebrae, sport-related injuries, epicondylitis, and cutaneous ulcers, and with cases of osteoarthritis of the coxa.

CONCLUSIONS:

Treatment with 904-nm diode laser has substantially reduced the symptoms as well as improved the quality of life of these patient, ultimately postponing the need for surgery.

J Altern Complement Med. 1999 Feb;5(1):5-26.

Carpal tunnel syndrome: clinical outcome after low-level laser acupuncture, microamps transcutaneous electrical nerve stimulation, and other alternative therapies–an open protocol study.

Branco K, Naeser MA.

Source

Acupuncture Healthcare Services, Westport, Massachusetts, USA.

 

Abstract

OBJECTIVE:

Outcome for carpal tunnel syndrome (CTS) patients (who previously failed standard medical/surgical treatments) treated primarily with a painless, noninvasive technique utilizing red-beam, low-level laser acupuncture and microamps transcutaneous electrical nerve stimulation (TENS) on the affected hand; secondarily, with other alternative therapies.

DESIGN:

Open treatment protocol, patients diagnosed with CTS by their physicians.

SETTING:

Treatments performed by licensed acupuncturist in a private practice office.

SUBJECTS:

Total of 36 hands (from 22 women, 9 men), ages 24-84 years, median pain duration, 24 months. Fourteen hands failed 1-2 surgical release procedures. INTERVENTION/TREATMENT: Primary treatment: red-beam, 670 nm, continuous wave, 5 mW, diode laser pointer (1-7 J per point), and microamps TENS (< 900 microA) on affected hands. Secondary treatment: infrared low-level laser (904 nm, pulsed, 10 W) and/or needle acupuncture on deeper acupuncture points; Chinese herbal medicine formulas and supplements, on case-by-case basis. Three treatments per week, 4-5 weeks.

OUTCOME MEASURES:

Pre- and posttreatment Melzack pain scores; profession and employment status recorded.

RESULTS:

Posttreatment, pain significantly reduced (p < .0001), and 33 of 36 hands (91.6%) no pain, or pain reduced by more than 50%. The 14 hands that failed surgical release, successfully treated. Patients remained employed, if not retired. Follow-up after 1-2 years with cases less than age 60, only 2 of 23 hands (8.3%) pain returned, but successfully re-treated within a few weeks.

CONCLUSIONS:

Possible mechanisms for effectiveness include increased adenosine triphosphate (ATP) on cellular level, decreased inflammation, temporary increase in serotonin. There are potential cost-savings with this treatment (current estimated cost per case, $12,000; this treatment, $1,000). Safe when applied by licensed acupuncturist trained in laser acupuncture; supplemental home treatments may be performed by patient under supervision of acupuncturist.

J Clin Laser Med Surg. 1998 Jun;16(3):145-51.

Treatment of medial and lateral epicondylitis–tennis and golfer's elbow–with low level laser therapy: a multicenter double blind, placebo-controlled clinical study on 324 patients.

Simunovic Z, Trobonjaca T, Trobonjaca Z.

Source

Laser Center, Locarno, Switzerland. tzlatko@mamed.medri.hr

 

Abstract

BACKGROUND AND OBJECTIVE:

Among the other treatment modalities of medial and lateral epicondylitis, low level laser therapy (LLLT) has been promoted as a highly successful method. The aim of this clinical study was to assess the efficacy of LLLT using trigger points (TPs) and scanner application techniques under placebo-controlled conditions.

STUDY DESIGN/MATERIAL AND METHODS:

The current clinical study was completed at two Laser Centers (Locarno, Switzerland and Opatija, Croatia) as a double-blind, placebo controlled, crossover clinical study. The patient population (n = 324), with either medial epicondylitis (Golfer's elbow; n = 50) or lateral epicondylitis (Tennis elbow; n = 274), was recruited. Unilateral cases of either type of epicondylitis (n = 283) were randomly allocated to one of three treatment groups according to the LLLT technique applied: (1) Trigger points; (2) Scanner; (3) Combination Treatment (i.e., TPs and scanner technique). Bilateral cases of either type of epicondylitis (n = 41) were subject to crossover, placebo-controlled conditions. Laser devices used to perform these treatments were infrared (IR) diode laser (GaAlAs) 830 nm continuous wave for treatment of TPs and HeNe 632.8 nm combined with IR diode laser 904 nm, pulsed wave for scanner technique. Energy doses were equally controlled and measured in Joules/cm2 either during TPs or scanner technique sessions in all groups of patients. The treatment outcome (pain relief and functional ability) was observed and measured according to the following methods: (1) short form of McGill's Pain Questionnaire (SF-MPQ); (2) visual analogue scales (VAS); (3) verbal rating scales (VRS); (4) patient's pain diary; and (5) hand dynamometer.

RESULTS:

Total relief of the pain with consequently improved functional ability was achieved in 82% of acute and 66% of chronic cases, all of which were treated by combination of TPs and scanner technique.

CONCLUSIONS:

This clinical study has demonstrated that the best results are obtained using combination treatment (i.e., TPs and scanner technique). Good results are obtained from adequate treatment technique correctly applied, individual energy doses, adequate medical education, clinical experience, and correct approach of laser therapists. We observed that under- and overirradiation dosage can result in the absence of positive therapy effects or even opposite, negative (e.g., inhibitory) effects. The current clinical study provides further evidence of the efficacy of LLLT in the management of lateral and medial epicondylitis.

Radiol Med. 1998 Apr;95(4):303-9.

[Low-level laser therapy in osteoarticular diseases in geriatric patients].

[Article in Italian]
Giavelli S, Fava G, Castronuovo G, Spinoglio L, Galanti A.

Source

Dipartimento di Radiologia e Laserterapia, Istituto Gerontologico Pio Albergo Trivulzio, Milano.

 

Abstract

INTRODUCTION:

Laser light absorption through the skin causes tissue changes, targeting the nervous, the lymphatic, the circulatory and the immune systems with an antalgic, anti-inflammatory, anti-edemic effect and stimulating tissue repair. Therefore low level laser therapy is now commonly used in numerous rehabilitation centers, including the "Istituto Gerontologico Pio Albergo Trivulzio", Milan, Italy. However, to activate the treatment program, the basic medical research results must always be considered to choose the best optical wavelength spectrum, technique and dose, for rehabilitative laser therapy. We analyzed the therapeutic effects of different wavelengths and powers in various treatment schedules. In particular, a protocol was designed to test such physical parameters as laser type, doses and individual schedule in different pathologic conditions. We report the results obtained with low level laser therapy in the rehabilitation of geriatric patients, considering the various physical and technical parameters used in our protocol.

MATERIAL AND METHODS:

We used the following laser equipment: an HeNe laser with 632.8 nm wavelength (Mectronic), a GaAs Laser with 904 nm wavelength (Mectronic) and a CO2 Laser with 10,600 nm wavelength (Etoile). To evaluate the patient clinical status, we use a different form for each involved joint; the laser beam is targeted on the region of interest and irradiation is carried out with the sweeping method or the points technique. Irradiation technique, doses and physical parameters (laser type, wavelength, session dose and number) are indicated on the form. The complete treatment cycle consists of 5 sessions per week–20 sessions in all. At the end of the treatment cycle, the results were scored on a 5-grade semiquantitative scale–excellent, good, fair, poor and no results. We examined 3 groups of patients affected with gonarthrosis (149 patients), lumbar arthrosis (117 patients), and algodystrophy (140 patients) respectively.

RESULTS:

In gonarthrosis patients, the statistical analysis of the results showed no significant differences between CO2 laser and GaAs laser treatments (p = .975), but significant differences between CO2 laser and HeNe laser treatments (p = .02) and between GaAs laser and HeNe laser treatments (p = .003). In lumbar arthrosis patients treated with GaAs or HeNe laser, significant differences were found between the two laser treatments and the combined sweeping-points techniques appeared to have a positive trend relative to the sweeping method alone, especially in sciatic suffering. In the algodystrophy syndrome, in hemiplegic patients, significant differences were found between CO2 and HeNe laser treatments (p = .026), between high and low CO2 laser doses (p = .024), and between low CO2 laser dose and high HeNe laser dose (p = .006).

CONCLUSIONS:

Low level laser therapy can be used to treat osteoarticular pain in geriatric patients. To optimize the results, the diagnostic picture must be correct and a treatment program defining the physical parameters used (wavelength, dose and irradiation technique) must also be designed.

Vojnosanit Pregl. 1997 Nov-Dec;54(6):533-40.

Influence of low level laser irradiation on biochemical processes in brainstem and cortex of intact rabbits.

[Article in English, Serbian]
Konstantinovi? L, Cernak I, Proki? V.

Source

Military Medical Academy, Clinic of Physical Medicine and Rehabilitation, Belgrade.

 

Abstract

The influence of low level laser (LLL) irradiation at wavelength at 660 and 904 nm on oxidative stress (lipid peroxidation activity-LP, production of superoxide anion radicals-NBT reduction), activity of enzymes of antioxidative defense (superoxide dismutase-SOD, glutathione reductase-GR) and functional activity of sodium pump (Na+K+ ATPase) in relation with applied wavelength of LLL was investigated. The investigation was performed at the adult rabbits (n = 21) classificated in three groups: control group (C), the group of rabbits irradiated with LLL wavelength 904 nm (CL1) and the group of rabbits irradiated with LLL wavelength 660 nm (CL2). The irradiation was performed in the upper cervical region in the anatomical projection of the brainstem. It was established that LLL induced oxidative stress in the brainstem and the cortex of treated rabbits, independently of applied wavelength of laser beams. The registrated changes in functional activity of sodium pump were dependent on the applied wavelength. The irradiation at 904 nm caused the significant increase of the substrate uptake rate of sodium pump in the brainstem tissue. The irradiation at 660 nm caused the "competitive inhibition" of the sodium pump. Decrease of norepinefrine content in the brainstem of treated rabbits pointed on the indirect mechanism of functional activity of sodium pump as well as the oxidative stress.

Vojnosanit Pregl. 1997 Sep-Oct;54(5):459-63.

[Combined low-power laser therapy and local infiltration of corticosteroids in the treatment of radial-humeral epicondylitis].

[Article in Serbian]
Konstantinovi? L, Antoni? M, Brdareski Z.

Source

Vojnomedicinska akademija, Klinika za fizikalnu medicinu i rehabilitaciju, Beograd.

 

Abstract

The prospective study included 32 patients with radiohumeral epicondylitis. They are by single-blind method divided into three groups: Group I (n = 11) was treated with low power laser therapy (904 nm, 5 kHz, in the dose of 1 J/cm2); Group II (n = 11) was treated with corticosteroid infiltration and group III (n = 10) was treated with combination of initial infiltration and subsequent laser therapy. The estimation of therapy effect was done by pain intensity follow-up with modified McGuill's questionnaire. The results of the first control examination, 7 days after the therapy onset, demonstrated significantly higher analgesic effect to be achieved in the group of patients treated with combination of corticosteroid infiltration and laser therapy. Similar results were noticed in the other two groups after the repeated same treatment.

Mol Cell Biochem. 1997 Apr;169(1-2):51-9.

Infra-red laser irradiation enhances interleukin-1 receptor antagonist, increases 3H-thymidine incorporation and the release of [3H]arachidonic acid in human monocytes.

Reale M, Orso C, Castellani ML, Barbacane RC, Placido FC, Porreca E, Di Febbo C, Cataldo I, Vacalis D, Anogianakis G, Trakatellis A, Conti P.

Source

Immunology Division, S.S. Annunziata Hospital, University G. D'Annunzio, School of Medicine, Chieti, Italy.

 

Abstract

The effect of infra-red laser irradiation has been experimented on various biological systems and particularly in human tissues, in vitro as well as in vivo. In order to examine the influence of laser irradiation on cells of the monocytic lineage we have irradiated human peripheral blood mononuclear cells with an infra-red laser at a wavelength of 904 nm, at 2000 Hz frequency and 15 mW for 2 min. Here, we report that laser irradiation for 2 min. at different preincubation times (T = 0 and T = 30 min) enhances LPS (10 micrograms/ml or PHA (10 micrograms/ml, suboptimal concentration)-stimulated monocytes by modifying cell proliferation, as judged by [3H] thymidine incorporation. IL-1 receptor antagonist (IL-1ra) along with an increased release of [3H] Arachidonic acid production, is also influenced by laser irradiated monocytes when treated for 2 min after 1 h incubation. IL-1RA production increased 4-5 fold after laser irradiation, while 3H-arachidonic acid incorporated from PMA-stimulated cells increased and the effect was significant at T = 0 and T = 30 min; while at T = 1 h the effect was negligible. These results may provide new information regarding the effect of laser irradiation on the immune system.

J Clin Laser Med Surg. 1996 Aug;14(4):163-7.

Low level laser therapy with trigger points technique: a clinical study on 243 patients.

Simunovic Z.

Source

Laser Center, Locarno, Switzerland.

 

Abstract

Among the various methods of application techniques in low level laser therapy (LLLT) (HeNe 632.8 nm visible red or infrared 820-830 nm continuous wave and 904 nm pulsed emission) there are very promising "trigger points" (TPs), i.e., myofascial zones of particular sensibility and of highest projection of focal pain points, due to ischemic conditions. The effect of LLLT and the results obtained after clinical treatment of more than 200 patients (headaches and facial pain, skeletomuscular ailments, myogenic neck pain, shoulder and arm pain, epicondylitis humery, tenosynovitis, low back and radicular pain, Achilles tendinitis) to whom the "trigger points" were applied were better than we had ever expected. According to clinical parameters, it has been observed that the rigidity decreases, the mobility is restored (functional recovery), and the spontaneous or induced pain decreases or even disappears, by movement, too. LLLT improves local microcirculation and it can also improve oxygen supply to hypoxic cells in the TP areas and at the same time it can remove the collected waste products. The normalization of the microcirculation, obtained due to laser applications, interrupts the "circulus vitiosus" of the origin of the pain and its development (Melzak: muscular tension > pain > increased tension > increased pain, etc.). Results measured according to VAS/VRS/PTM: in acute pain, diminished more than 70%; in chronic pain more than 60%. Clinical effectiveness (success or failure) depends on the correctly applied energy dose–over/underdosage produces opposite, negative effects on cellular metabolism. We did not observe any negative effects on the human body and the use of analgesic drugs could be reduced or completely excluded. LLLT suggests that the laser beam can be used as monotherapy or as a supplementary treatment to other therapeutic procedures for pain treatment.

Przegl Lek. 1995;52(1):13-5.

[Personal experience in clinical use of low power laser therapy].

[Article in Polish]
Sieron A, Adamek M, Cie?lar G, Zmudzi?ski J.

Source

III Katedry i Kliniki Chorób Wewnetrznych Slaskiej AM w Bytomiu.

 

Abstract

The results of our own clinical trials regarding therapeutical effects of low power lasers in the treatment of some diseases of motional system, skin and lesions of peripheral circulation were presented in the paper. The laser therapy was used in over 320 patients in period of last 3 years. The infra-red laser (wave-length 904 nm, mean power 4 mW) was used. The procedures were performed daily, for 5 days a week in 2 stages: the scan of sore region (3-min.) and the irradiation of trigger points (2-3 min. each). As a result of 10-25 procedures a significant clinical improvement in 65-90% patients was obtained. On the base of obtained results one can conclude that low-power laser therapy could make a useful supplementary method of treatment of overloading syndrome of motional system, postthrombotic syndrome, lymphatic edema and trophic lesions of skin.

Folia Med (Plovdiv). 1992;34(3-4):29-31.

Therapeutic effect of the laser system Prometeus in the treatment of vertebrogenic lumboradiculalgia.

Toshev I, Gozmanov G, Kitov B, Madzhurov P.

Source

Department of Neurosurgery, University of Medicine, Plovdiv, Bulgaria.

 

Abstract

The authors report their experience in the application of laser therapy using 904 nm laser irradiation and impulse power of 10 W on patients with vertebrogenic lumboradiculalgia (osteochondrosis and herniation of the intervertebral disk). The therapeutic effect of the PROMETEUS type laser system is compared to that of similar equipment reported in literature. Pain was usually relieved between days five and 10 of laser therapy, or, in cases of slower convalescence, by day 15. Clinical symptoms of the disorders also disappeared simultaneously with the alleviation of pain. Our results are similar to those obtained by A.S. Krjuk (1986) and S. Gatev (1985), better than those of Van Lyancin (1988) and worse than those of D. Milani (1987). Laser therapy produces no side effects. It is an important contribution to the armamentarium of modern physiotherapeutic methods. When it is administered properly, it is painless, aseptic and does not cause trauma or allergic reactions. Moreover, it reduces the usage of drugs and consumable materials.

J Pain Symptom Manage. 1991 May;6(4):241-6.

Is low-energy laser treatment effective in lateral epicondylalgia?

Haker E, Lundeberg T.

Abstract

The aim of this double-blind study was to explore the pain-alleviating effect of low energy laser in lateral epicondylalgia. Forty-nine patients were consecutively assigned at random to two groups, laser or placebo. The Mid 1500 Irradia laser was used with the following parameters: wavelength 904 nm; average power output 12 mW; peak value 8.3 W; frequency 70 Hz (pulse train 8000 Hz). The laser (Ga-As) was locally applied to 6 sites on and around the epicondyle. Each point was treated for 30 sec, resulting in a dose of 0.36 J/point and an area of treatment of 0.2 mm2. Patients were treated 2-3 times weekly, for a total of 10 treatments. Follow-ups were done after three and 12 mo. The statistical analysis showed that the laser treated group had a significant improvement in some objective outcomes after the treatment period and at the 3 mo follow-up, but there were no significant differences in the subjective outcomes between the groups. Irradia laser treatment may be a valuable therapy in lateral epicondylalgia, if carried out as described in this study. However, further studies are necessary before low energy laser can be employed as a pain-relieving method.

rch Stomatol (Napoli). 1990 Apr-Jun;31(2):277-89.

[Laser in periodontology: theoretical-experimental approach. 3. Experimental study of the effects of He-Ne (638 nm) and infrared diodic (904 nm) lasers on the gingival mucosa of rats].

[Article in Italian]
Caruso F, Gaeta GM, Chieffi Baccari G, Guida L, Iuorio G.

SourcUniversità degli Studi di Napoli.

 

Abstract

Medical and surgical laser-therapy is becoming more and more important in various branches of Medicine, however independently from clinical results still very little is known about physical-biological interaction between laser beam and living matter. The aim of this study is of finding tissutal and cellular effects of stimulation with soft and mid laser. The study started from an original work carried out at the Institute of Biology of the 1st Faculty of Medicine and Surgery of Naples University from which appears the possibility of visualizing the stage of nuclear active synthesis of the cell, simply by Maloory tricromic colouring. By this method the cellular nucleuses take, usually, a red colour, however in presence of an increase of the RNA nuclear synthesis the nucleuses take a typical blue colour. The importance of the study induced us to research the presence in the oral mucose of the rat after radiation as an effect of biostimulation. The results of this study showed and increase of the epithelial cheratine and a variation of the disposition and of the number of the precheratine grains in treated site. The blue nucleuses have been found at the basal level without any difference between treated and control site. On the other hand their presence is the normal consequence of the epithelial evolution which starts from the basal level which is the most active in the stage of nuclear synthesis.

 

Acta Stomatol Croat. 1990;24(4):281-8.

[Use of soft laser in the treatment of oral symptoms].

[Article in Croatian]
Ceki?-Arambasin A, Durdevi?-Mati? A, Mravak-Stipeti? M, Bili? A.

Abstract

Due to insufficient casual therapy of oral symptoms of dyniae and pyrosis, we applied infrared soft laser in treatment of patients with those oral symptoms. The laser had a wavelength of 904 nm and a radiation strength of 20 W. The tests were performed on 40 persons with stomatopyrosis and stomatodiniae symptoms, under application of laser through 5 days consecutively with radiation of mucosa lasting 3 minutes on 1 cm2. The testing group was represented by persons exclusively under the laser therapy and the control group was represented by 30 persons, who were under a medicamentose therapy with vasodilatator applied with iontophoresis. By persons with stomatopyrosis and stomatodiniae symptoms analgetic effect was attained through the therapy with the laser already after the first application, and the pain and aches intensity was relieved every day during the therapy, by stomatodinae to complete healing. The obtained differences in the intensity of symptoms before and after the therapy were statistically important. The thermoestesiometric determination of laser efficiency by vasodilatation showed differences which were not important, although the temperature during the therapy has slightly increased for 0.1 degrees C. The soft laser can be used as an effective remedy in the treatment of oral symptoms of stomatopyrosis and stomatodinae.

 

 

Lasers Surg Med. 1989;9(1):50-8.

Effect of helium-neon and infrared laser irradiation on wound healing in rabbits.

Braverman B, McCarthy RJ, Ivankovich AD, Forde DE, Overfield M, Bapna MS.

Source

Department of Anesthesiology, Rush-Presbyterian-St. Luke's Medical Center, Chicago, IL 60612.

 

Abstract

We examined the biostimulating effects of helium-neon laser radiation (HeNe; 632.8 nm), pulsed infrared laser radiation (IR; 904 nm), and the two combined on skin wound healing in New Zealand white rabbits. Seventy-two rabbits received either 1) no exposure, 2) 1.65 J/cm2 HeNe, 3) 8.25 J/cm2 pulsed IR, or 4) both HeNe and IR together to one of two dorsal full-thickness skin wounds, daily, for 21 days. Wound areas were measured photographically at periodic intervals. Tissue samples were analyzed for tensile strength, and histology was done to measure epidermal thickness and cross-sectional collagen area. Significant differences were found in the tensile strength of all laser-treated groups (both the irradiated and nonirradiated lesion) compared to group 1. No differences were found in the rate of wound healing or collagen area. Epidermal growth was greater in the HeNe-lased area compared to unexposed tissue, but the difference was not significant. Thus, laser irradiation at 632.8 nm and 904 nm alone or in combination increased tensile strength during wound healing and may have released tissue factors into the systemic circulation that increased tensilestrength on the opposite side as well.

Scand J Rheumatol. 1989;18(6):427-31.

Low power laser therapy of shoulder tendonitis.

England S, Farrell AJ, Coppock JS, Struthers G, Bacon PA.

Source

Department of Rheumatology, Coventry & Warwickshire Hospital, UK.

 

Abstract

30 patients with supraspinatus or bicipital tendonitis were randomly allocated to active infrared laser therapy at 904 nm three times weekly for 2 weeks, dummy laser or drug treatment for 2 weeks. Objectively maximum active extension, flexion and abduction of the shoulder, and subjectively pain stiffness movement and function were measured at 0 and 2 weeks. Significant improvement of active over dummy laser was noted for all seven assessments. Active laser therapy produced significant improvement over drug therapy for all three objective measures and pain. Naproxen sodium significantly improved only movement and function compared to dummy laser. These results demonstrate the effectiveness of laser therapy in tendonitis of the shoulder.

Acupunct Electrother Res. 1989;14(1):9-14.

Effects of the infrared laser therapy at treated and non-treated trigger points.

Olavi A, Pekka R, Pertti K, Pekka P.

Source

Department of Physical Medicine and Rehabilitation, University Central Hospital, Kuopio, Finland.

 

Abstract

For reliability of the pain threshold measurement there were measured first 390 trigger points of 22 healthy students twice at each point. The reliability of two different measurements was found to be perfect. Infrared (904 nm) laser therapy was compared to placebo laser at the trigger points. Our study tested eighteen patients (11 men and 7 women), with 31 active trigger points in the muscles of the infraspinatus, extensor carpi radialis, levator scapulae, trapezius and tibialis anterior. Trigger points were randomly managed by infrared laser (dose 1.5J/point and place laser. The study was carried out by double-blind and cross-over principle. The responses of the management were documented by the pain threshold meter measurements of these trigger points before and after the treatments, and then fifteen minutes later. The trigger points of the other side of the body were also measured from the same muscles. In the results there were observed highly significant changes between the laser and placebo groups immediately after the treatment, 0.97 (SE 0.16) kg/cm2 (p less than 0.001). The differences between these two treatments were greater after fifteen minutes of the therapy–1.87 (SE 0.30) kg/cm2 (p less than 0.001). At the non-treated trigger points, the significant increase of the values was seen after fifteen minutes (p less than 0.05). Our research study results suggest that infrared laser had an effect at the trigger points and that the treatment significantly increased the pain threshold.

Lasers Surg Med. 1987;7(5):444-7.

Effect of diodes-laser silver arsenide-aluminium (Ga-Al-As) 904 nm on healing of experimental wounds.

Longo L, Evangelista S, Tinacci G, Sesti AG.

Source

Laser Therapy Unit, Villa Donatello, Firenze, Italy.

 

Abstract

Diodes-laser silver arsenide-aluminium (Ga-Al-As) 904 nm, which was used because of its properties of good tissue penetration and manageability, applied 5 min daily for 5 days at 3,000 Hz of frequency (energy density = 3 J), promoted healing of experimental wounds in rats from both a microscopic and histologic point of view. The same laser applied in these experimental conditions (number of rats was eight for each group) at the same energy density (3 J) for 10 min daily during 5 days at 1,500 Hz of frequency did not affect the experimental wounds.

Arch Orthop Trauma Surg. 1987;106(6):358-63.

What is the efficacy of "soft" and "mid" lasers in therapy of tendinopathies? A double-blind study.

Siebert W, Seichert N, Siebert B, Wirth CJ.

Source

Department of Orthopedics, Grosshadern Hospital, Munich University Medical School, Federal Republic of Germany.

 

Abstract

The efficacy of "athermic" lasers (HeNe lambda = 632.8 nm and IR diode lambda = 904 nm) in the treatment of tendinopathies was investigated in a randomized double-blind study. On 10 consecutive days, 64 patients (32 therapy, 32 placebo) were treated for 15 minutes each with a switched-on or switched-off laser under otherwise identical conditions. The extent of movement in involved joints (neutral 0 method) and rating on a pain scale for resting pain, movement pain, and pressure pain before treatment, after treatment, and 2 weeks after conclusion of therapy, as well as infrared thermography, served to check therapy. After the end of therapy, a significant reduction (P = less than 0.001) of 50% was shown for resting pain as well as reductions of 30% for movement and 30% for pressure pain. This result was identical in the therapy group and in the placebo group. There was also no indication of a different result of therapy between the therapy and placebo groups with regard to the thermographic control and the extent of movement. The breakdown of the data in terms of age, sex, and duration of disease did not provide any indications of different results for placebo or therapy. It was striking that the patients who reported sensations during or after the treatment (irrespective of whether pleasant or unpleasant) had a greater reduction of pain than the patients without sensations. This laser therapy thus did not show any effect above and beyond that in the untreated group in our double-blind clinical study.

 

 

 

 

 

 

Vet Surg. 1987 Jan-Feb;16(1):106-10.

Treatment of chronic back pain in horses. Stimulation of acupuncture points with a low powered infrared laser.

Martin BB Jr, Klide AM.

Source

University of Pennsylvania, School of Veterinary Medicine, Department of Clinical Studies-New Bolton Center, Philadelphia 19348.

 

Abstract

Fourteen horses that could not perform at their expected standards due to chronic back pain of 4 to 48 months duration, and had not obtained lasting improvement from other forms of therapy, were treated by stimulating nine acupuncture points using a low powered infrared laser (300 microW, 904 nm). The treatments were performed weekly, and consisted of stimulating each point for 2 minutes with a pulse frequency of 360 pulses per second. After completion of a mean of 11 treatments, clinical signs of back pain were alleviated in 10 of the 14 horses, there was no change in three, and one was lost to follow-up. Of the 10 horses who were training and competing, four won. One year after treatment was discontinued, 9 of these 10 horses continued to perform at a standard acceptable to the owner.

Mod Vet Pract. 1984 Mar;65(3):210-3.

Use of laser light to treat certain lesions in standardbreds.

McKibbin LS, Paraschak D.

Abstract

The final and last-quarter race times and racing classes for a group of Standardbreds were analyzed before and after infrared laser light treatment. These horses had either check ligament injuries, plantar desmitis or pharyngeal lymphoid hyperplasia. A 904-nm infrared laser was used to treat check ligaments at 146 Hz for 26 sec/cm2 of affected area, acute plantar desmitis at 73 Hz and chronic plantar desmitis at 292 Hz for 26 sec/cm2 of affected area, and pharyngeal lymphoid hyperplasia at 146 Hz for 5 minutes. Of 35 horses treated for check ligament injuries, 80% had similar or faster final race times, 68.6% had similar or faster last-quarter times, and 68.6% raced in similar or higher classes after treatment. Of 8 horses treated for plantar desmitis, 87.5% had similar or faster final and last-quarter times, and raced in similar or higher classes after treatment. Of 30 horses treated for pharyngeal lymphoid hyperplasia, 80% had similar or faster final race times, 90% had similar or faster last-quarter times, and 70% raced in similar or higher classes after treatment.

 

 

Lasers Surg Med. 1983;3(1):55-9.

A study of the effects of lasering on chronic bowed tendons at Wheatley Hall Farm Limited, Canada, January, 1983.

McKibbin LS, Paraschak DM.

Abstract

Chronic bowed tendons of horses have been lasered with an infrared 904-nm laser at Wheatley Hall Farm Limited since 1980. A sample of 42 single injury/single treatment standardbreds which were racing within 120 days of laser treatment and met certain criteria, were evaluated for final race times, last quarter race times, and class changes. Results indicate that a significant percent of the standardbreds raced with similar or improved times and classes. Lasering bowed tendons presents a safe and less expensive alternative to traditional treatment methods which often requires a year layoff for the horse.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Retinitis Pigmentosa

Adv Exp Med Biol. 2016;854:437-41. doi: 10.1007/978-3-319-17121-0_58.

Near-Infrared Photobiomodulation in Retinal Injury and Disease.

Eells JT1, Gopalakrishnan S2, Valter K3.
Author information
1Department of Biomedical Sciences, University of Wisconsin-Milwaukee, 2400 E. Hartford Ave., 53201, Milwaukee, WI, USA. jeells@uwm.edu.
2College of Nursing, University of Wisconsin-Milwaukee, 53201, Milwaukee, WI, USA. sandeep@uwm.edu.
3Divsion of Biomedical Sciences, Research School of Biology, Australian National University, 0200, Acton, Australia. krisztina.valter-kocsi@anu.edu.au.
Abstract
Evidence is growing that exposure of tissue to low energy photon irradiation in the far-red (FR) to near-infrared (NIR) range of the spectrum, collectively termed “photobiomodulation” (PBM) can restore the function of damaged mitochondria, upregulate the production of cytoprotective factors and prevent apoptotic cell death. PBM has been applied clinically in the treatment of soft tissue injuries and acceleration of wound healing for more than 40 years. Recent studies have demonstrated that FR/NIR photons penetrate diseased tissues including the retina. The therapeutic effects of PBM have been hypothesized to result from intracellular signaling pathways triggered when FR/NIR photons are absorbed by the mitochondrial photoacceptor molecule, cytochrome c oxidase, culminating in improved mitochondrial energy metabolism, increased cytoprotective factor production and cell survival. Investigations in rodent models of methanol-induced ocular toxicity, light damage, retinitis pigmentosa and age-related macular degeneration have demonstrated the PBM attenuates photoreceptor cell death, protects retinal function and exerts anti-inflammatory actions.
 .
Lasers Med Sci. 2015 Sep 24. [Epub ahead of print]

Effects of low-level laser irradiation on proliferation and functional protein expression in human RPE cells.

Dang Y1,2, Wu W2, Xu Y2,3, Mu Y4, Xu K4, Wu H2,5, Zhu Y6, Zhang C7.
Author information
1Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, 1 East Jianshe Road, Erqi District, Zhengzhou, China.
2Clinical Stem Cell Research Center, Peking University Third Hospital, 49 Huayuan North Road, Haidian District, Beijing, China.
3Clinical Lab of Tissue & Cell Research Center, Department of Biotech Treatment, Logistics College of Chinese People’s Armed Police Force, Tianjin, China.
4Department of Ophthalmology, Yellow-River Hospital, Henan University of Science and Technology, Sanmenxia, China.
5Beijing No.4 High School, Beijing, China.
6Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, 1 East Jianshe Road, Erqi District, Zhengzhou, China. asiadragon@163.com.
7Clinical Stem Cell Research Center, Peking University Third Hospital, 49 Huayuan North Road, Haidian District, Beijing, China. zhangc1@yahoo.com.
Abstract
Low-level laser irradiation (LLLI) modulates a set of biological effects in many cell types such as fibroblasts, keratinocytes, and stem cells. However, no study to date has reported the effects of LLLI on retinal pigment epithelia (RPE) cells. The aim of this study was to investigate whether LLLI could enhance the proliferation of RPE cells and increase the expression of RPE functional genes/proteins. Human ARPE-19 cells were seeded overnight and treated with 8 J/cm2 of LLLI. Cell proliferation was measured by CCK8 assay and cell cycle distribution was evaluated by FACS. The transcription of cell cycle-specific genes and RPE functional genes was quantified by RT-PCR. Moreover, the expression of ZO-1 and CRALBP were evaluated by immunostaining. A dose of 8 J/cm2 of LLLI significantly increased proliferation and promoted cell cycle progression while upregulating the transcription of CDK4 and CCND1 and decreasing the transcription of CDKN2A, CDKN2C, and CDKN1B in human ARPE-19 cells. Additionally, LLLI enhanced the expression of ZO-1 and CRALBP in human ARPE-19 cells. In conclusion, LLLI could enhance the proliferative ability of human ARPE-19 cells by modulating cyclin D1, CDK4, and a group of cyclin-dependent kinase inhibitors. It also could increase the expression of RPE-specific proteins. Thus, LLLI may be a potential approach for the treatment of RPE degenerative diseases.
.
Mol Vis. 2015; 21: 883–892.
Published online 2015 Aug 21.
PMCID: PMC4544713

Photobiomodulation with 670 nm light increased phagocytosis in human retinal pigment epithelial cells

Shinichiro Fuma, Hiromi Murase, Yoshiki Kuse, Kazuhiro Tsuruma, Masamitsu Shimazawa, and Hideaki Haracorresponding author
Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
corresponding authorCorresponding author.
Correspondence to: H. Hara, Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan; Phone: +81-58-230-8126; FAX: +81-58-230-8126; email: pj.ca.up-ufig@arahedih
Received 2015 Jan 29; Accepted 2015 Aug 19.

Abstract

Purpose

Photobiomodulation is the treatment with light in the far-red to near-infrared region of the spectrum and has been reported to have beneficial effects in various animal models of disease, including an age-related macular degeneration (AMD) mouse model. Previous reports have suggested that phagocytosis is reduced by age-related increased oxidative stress in AMD. Therefore, we investigated whether photobiomodulation improves phagocytosis caused by oxidative stress in the human retinal pigment epithelial (ARPE-19) cell line.

Methods

ARPE-19 cells and human primary retinal pigment epithelium (hRPE) cells were incubated and irradiated with near-infrared light (670 nm LED light, 2,500 lx, twice a day, 250 s/per time) for 4 d. Next, hydrogen peroxide (H2O2) and photoreceptor outer segments (POS) labeled using a pH-sensitive fluorescent dye were added to the cell culture, and phagocytosis was evaluated by measuring the fluorescence intensity. Furthermore, cell death was observed by double staining with Hoechst33342 and propidium iodide after photobiomodulation. CM-H2DCFDA, JC-1 dye, and CCK-8 were added to the cell culture to investigate the reactive oxygen species (ROS) production, mitochondrial membrane potential, and cell viability, respectively. We also investigated the expression of phagocytosis-related proteins, such as focal adhesion kinase (FAK) and Mer tyrosine kinase (MerTK).

Results

Oxidative stress inhibited phagocytosis, and photobiomodulation increased the oxidative stress-induced hypoactivity of phagocytosis in ARPE-19 cells and hRPE cells. Furthermore, H2O2 and photobiomodulation did not affect cell death in this experimental condition. Photobiomodulation reduced ROS production but did not affect cell viability or mitochondrial membrane potential. The expression of phosphorylated MerTK increased, but phosphorylated FAK was not affected by photobiomodulation.

Conclusions

These findings indicate that near-infrared light photobiomodulation (670 nm) may be a noninvasive, inexpensive, and easy adjunctive therapy to help inhibit the development of ocular diseases induced by the activation of phagocytosis.

Introduction

Age-related macular degeneration (AMD) is a progressive and degenerative eye disease that is a common cause of vision loss in developed countries [1]. AMD is classified into dry and wet types, and the main clinical feature common to both is the accumulation of lipofuscin in retinal pigment epithelium (RPE) cells. Wet AMD is characterized by abnormal angiogenesis, and dry AMD is characterized by atrophy of the outer retinal layers and RPE cells [2,3]. Risk factors for AMD, such as aging, light damage, smoking, genetic factors, and oxidative stress, have been reported to cause the accumulation of lipofuscin [4].

RPE cells help maintain the normal functions of photoreceptor cells by playing a role in phagocytosis, a part of the visual cycle, by forming a blood–retinal barrier that permits the exchange of waste products and nutrients between the blood and the retina [5,6]. Phagocytosis by RPE cells is an essential function of homeostasis in the retina. Photoreceptor cells are damaged by exposure to light. RPE cells can remove deteriorated photoreceptor outer segments (POS) via phagocytosis to preserve the function of photoreceptor cells [7]. It is important that the phagocytosis of RPE cells is not inhibited because the dysfunction of phagocytosis can trigger RPE damage and lysosomal disorder that prevents the breakdown of waste products, ultimately resulting in the accumulation of lipofuscin [8,9]. Thus, we believe the inhibition of lipofuscin accumulation is likely to improve AMD [10]. Phagocytosis of POS by RPE cells involves several steps, such as binding, uptake, and degradation, and each step is regulated by some proteins. Phagocytosis of POS by RPE cells requires ?v?5 integrin for binding [11]. Focal adhesion kinase (FAK) is a cytoplasmic protein tyrosine kinase and is phosphorylated by integrin engagement. Finnemann et al. have shown that POS binding by RPE cells increases FAK complex formation with ?v?5 integrin and activates FAK [11,12]. FAK is related to the binding of POS, whereas Mer tyrosine kinase (MerTK) is not required for binding but for internalization [12,13]. Rat RPE cells expressing MerTK can bind to the surface of RPE cells but have no effect on the internalization of POS [14].

The AMD models were appeared to mitochondrial dysfunction. The accumulation of lipofuscin decreased the mitochondrial membrane potential, impaired oxidative phosphorylation in the mitochondrial respiratory chain, and decreased the activity of phagocytosis [15].

Previous reports have shown that photobiomodulation, treatment with light in the far-red to near-infrared region of the spectrum, is beneficial in treating strokes, wounds, infection, diabetic retinopathy, and AMD [1619]. Its beneficial effects include regulating cell viability by absorbing near infrared light in photosensitive molecules such as water, melanin, hemoglobin, and cytochrome c oxidase molecules. Some of the most important photosensitive molecules that respond to photobiomodulation are cytochrome c oxidase molecules, which accept electrons and are involved in producing adenosine triphosphate (ATP) in mitochondrial oxidative phosphorylation [20]. It is known that photobiomodulation activates cytochrome coxidase and increases cellular ATP, resulting in the protection of neurons [21]. It has been reported that photobiomodulation suppresses the inflammation caused by decreased mitochondrial activity [16]. Other reports have suggested that photobiomodulation increases the expression of the antioxidant enzyme MnSOD without affecting cytochrome c oxidase activity (which is related to mitochondrial activity); thus, the mechanism of photobiomodulation effects is not clear [17]. However, it is well known that photobiomodulation has effects such as the upregulation of ATP, the increase of antioxidant materials, and the prevention of inflammation in retinal neurons [17,22,23]. However, the effect of photobiomodulation on phagocytosis in RPE cells remains unclear. In the present study, we therefore investigated the effect of photobiomodulation on the oxidative stress-induced hypoactivity of phagocytes in ARPE-19 cells and primary human RPE (hRPE) cells.

Methods

Cell culture

The human retinal pigment epithelial cell line (ARPE-19) was obtained from American Type Culture Collection (Manassas, VA). The cells were maintained in Dulbecco’s Modified Eagle’s medium (DMEM)/F-12 (Wako, Osaka, Japan) containing 10% fetal bovine serum (FBS), 100 U/ml penicillin, and 100 ?g/ml streptomycin. Cultures were maintained at 37 °C in a humidified atmosphere of 95% air and 5% CO2. The ARPE-19 cells were passaged by trypsinization every 3–4 d.

The primary hRPE cells were obtained from Lonza (Walkersville, MD). The cells were maintained in Retinal Pigment Epithelial Basal Medium (Lonza) containing 2% FBS, 4 mL L-glutamine (Lonza), 0.2 ml GA-1000 (Lonza), and 1 mL growth factor (FGF-B; Lonza) according to the manufacturer’s protocol. Cultures were maintained at 37 °C in a humidified atmosphere of 95% air and 5% CO2. The cells were passaged by Trypsin/EDTA (Lonza), Trypsin Neutralizing Solution (Lonza), and HEPES Buffered Saline Solution (Lonza) every 3–4 d.

Isolation from porcine eyes and labeling of photoreceptor outer segments

Retinas from freshly obtained porcine eyes were homogenized with POS buffer (115 mM NaCl, 2.5 mM KCl, 1 mM MgCl2, 10 mM HEPES/KOH ph 7.5, and 1 mM dithiothreitol) containing 1.5 mM sucrose on ice. The suspension was centrifuged for 7 min at 7,510 ×g to sediment chunk pieces of retinas. A filter (BD Falcon, Franklin Lakes, NJ) was used to remove the deposits, and the filtrate was diluted with POS buffer and centrifuged again. The pellet was diluted with POS buffer containing 0.6 mM sucrose. The suspension was then added to the tube containing the continuous sucrose gradient and the whole was centrifuged for 90 min at 103,700 ×g in RP55T rotor (Hitachi Co., Ltd. Tokyo, Japan). After centrifugation, POS bands were collected and diluted with 1:3 balanced salt solution (BSS; 10 mM HEDES, 137 mM NaCl, 5.36 mM KCl, 0.81 mM MgSO4, 1.27 mM CaCl2, 0.34 mM Na2HPO4, and 0.44 mM KH2PO4). This was suspended for 7 min at 7,510 ×g to obtain a pure POS pellet, which was then stored in darkness at ?80 °C. The supernatant was removed and the POS was taken up in several milliliters of POS buffer. The media were concentrated by centrifugation at 4,000 ×g using an Amicon Ultra-15 centrifugal filter device (Millipore, Billerica, MA; molecular weight cutoff: 3,000) to combine POS with pHrodo. Unlabeled POS (5 × 107) were added to 5 mL of the BSS. POS were labeled at a final concentration of 1 mg pHrodo/10 mg protein. POS with the dye were concentrated by centrifugation at 4,000 ×g using the Amicon Ultra-15 centrifugal filter device (Millipore; molecular weight cutoff: 3,000) for 6 h at 4 °C [24].

Near-infrared photobiomodulation

For all experiments, we followed this protocol before each assay: ARPE-19 cells were plated at a density of 1.5 × 104 cells per well with DMEM/F-12 containing 10% FBS in 96-well plates. This was incubated for 4 d with or without 670 nm light emitting diode (LED; Sawa Denshi Kougyou, Saitama, Japan) treatment (250 s at 3.89 mW/cm2 twice/day). The medium was changed to DMEM/F12 containing 1% FBS, and the cells were treated with an antioxidant, N-acetylcysteine (NAC; Sigma-Aldrich, St. Louis, MO) for 1 h.

Phagocytosis assays

H2O2 at a final concentration of 0.1 mM and 1 × 105 POS/well were added to each well and incubated for 6 h. The cells were then washed five times with 1% FBS DMEM/F-12 to allow removal of non-specific POS binding to quantify specific attachement of POS by RPE cells. Images were collected using a fluorescence microscope (BZ-9000; Keyence, Osaka, Japan) and then quantified using image processing software (Image-J, ver. 1.43 h; National Institutes of Health, Bethesda, MD). The area was then calculated.

Nuclear staining assay

Nuclear staining assays were conducted 6 h after H2O2 treatment.

Cell viability assay

Water-soluble tetrazolium salt 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5- (2,4-disulfophenyl)-2H-tetrazolium monosodium salt (WST-8) assay kits were used to investigate the inhibitory effect of photobiomodulation on oxidative stress-induced cytotoxicity. Briefly, 10 ?l of CCK-8 (Dojindo Laboratories, Kumamoto, Japan) was added to each well, and the cells were incubated at 37 °C for 2 h. The absorbance was measured at 492 nm (reference wavelength, 660 nm) using SkanIt Re for Varioskan Flash 2.4 (ThermoFisher Scientific Inc., Waltham, MA).

Measurement of intracellular reactive oxygen species production

The measurement of intracellular reactive oxygen species (ROS) production was estimated by CM-H2DCFDA (Invitrogen). Briefly, CM-H2DCFDA was added to the medium at a final concentration of 10 ?M, followed by incubation at 37 °C for 1 h. Fluorescence was then measured using a fluorescence spectrophotometer at 488 nm excitation and 525 nm emission.

Mitochondrial membrane potential assay

The measurement of mitochondrial membrane potential was estimated using JC-1 dye (Mitochondrial Membrane Potential Probe; Invitrogen). The ARPE-19 cells (1.5 × 104 cells/well) were cultured and exposed to H2O2 for 6 h. The cells were washed and incubated with 10 ?g/ml JC-1 at 37 °C for 15 min in the dark. Images were collected using a fluorescence microscope (BZ-9000; Keyence), which detects healthy cells with JC-1 J-aggregates (excitation/emission=540/605 nm) and unhealthy cells with mostly JC-1 monomers (excitation/emission=480/510 nm).

Western blot analysis

The ARPE-19 or hRPE cells (1.5 × 104 cells/well) were seeded onto a 24-well plate and cultured at 37 °C for 4 d. After H2O2 exposure, the cells were supplemented with a 1% protease inhibitor cocktail (Sigma), 1% phosphate inhibitor cocktails 2 and 3 (Sigma), and sample buffer (Wako). The lysate was centrifuged at 12,000 ×g for 10 min, and the supernatant was collected for analysis. Protein concentration was determined using a BCA protein assay kit (Pierce Biotechnology, Rockford, IL) with BSA as standard. An equal volume of protein sample and sample buffer with 10% 2-mercaptoethanol was electrophoresed with a 10% sodium dodecyl sulfate-polyacrylamide gel, and the separated proteins were then transferred onto a polyvinylidene difluoride membrane (Immobilon-P; Millipore). The following primary antibodies were used for immunoblotting: anti-MerTK (phospho Y749 + Y 753 + Y754; ab14921) rabbit polyclonal antibody (1: 500; abcam); anti-MerTK (ab137673) rabbit polyclonal antibody; anti-phospho-FAK (Tyr397) rabbit polyclonal antibody (1: 1000; Cell Signaling Technology, Danvers, MA); anti-FAK (C-903; sc-932) rabbit polyclonal antibody (1:1000; Santa Cruz Biotechnology, Inc. CA), and anti-?-actin mouse monoclonal antibody (1:5000; Sigma). An HRP-conjugated goat anti-rabbit antibody and an HRP-conjugated goat anti-mouse antibody (1:2000) were used as secondary antibodies. Band densities were measured using an imaging analyzer (LAS-4000 mini, Fujifilm, Tokyo, Japan), gel analysis software (Image Reader LAS-4000; Fujifilm), and detected band analysis software (Multi Gauge; Fujifilm).

Statistical analysis

Data are presented as the mean ± standard error of the mean (SEM). Statistical comparisons were made using a two-tailed paired Student t test only, where p<0.05 indicated statistical significance.

Results

Photobiomodulation enhanced the phagocytic activity in oxidative stress

To clarify the effect on phagocytic activity in near-infrared light-exposed ARPE-19 cells, the phagocytic activity in the cells was investigated after 6 h of H2O2 exposure by measuring the fluorescence intensity of intracellular POS. The quantification of fluorescence intensity was calculated as described in the Methods section. The fluorescence intensity was significantly reduced after H2O2 exposure, and NAC, an antioxidant, increased the fluorescence intensity. Moreover, photobiomodulation enhanced the fluorescence intensity of intracellular POS in comparison to the group that was only exposed to H2O2 (Figure 1 B,C). The group exposed to H2O2 and NAC group maybe also invreased the fluorescence intensity but we did not use statistical analysis between H2O2 only group and H2O2/NAC group. H2O2 or photobiomodulation did not affect cell death in this experimental condition (Figure 1D).

Figure 1

Photobiomodulation enhanced the phagocytic activity in oxidative stress. A: ARPE-19 cells were seeded at a density of 15,000 cells/well and incubated for 4 day. During this period, they were irradiated with near-infrared light. After 4 day, the medium

Photobiomodulation did not affect cell viability or mitochondrial membrane potential but reduced reactive oxygen species production

Cell viability was determined by WST-8 assay in order to clarify the other effects of photobiomodulation in ARPE-19 cells. In the group exposed only to H2O2, cell viability was reduced for 6 h compared to the control group with a reduction of 21%. Photobiomodulation did not affect cell viability (Figure 2A). CM-H2DCFH is converted to a fluorescent product (CM-H2DCF) when intracellular ROS are produced, was increased by H2O2 exposure, and 1 mM NAC significantly reduced the oxidative stress-induced ROS production in ARPE-19 cells. Daily exposure to 250 s of 670 nm photobiomodulation significantly inhibited the H2O2-induced ROS production (Figure 2B). To investigate the effect of photobiomodulation on mitochondrial activity, JC-1 dye was used. Neither H2O2 nor photobiomodulation significantly changed the red or green fluorescence (Figure 2C)

Figure 2

Photobiomodulation reduced ROS production but did not change the cell viability or mitochondrial membrane potential. A: Cell viability was measured using a WST-8 assay kit. Cell viability was reduced by oxidative stress, and photobiomodulation did not

Photobiomodulation increased the expression of phosphorylated MerTk but did not change the expression of phosphorylated FAK

We investigated the mechanism of the promotion of phagocytosis by photobiomodulation. We tested changes in the levels of phagocytosis-associated proteins, FAK and MerTK, by western blot analysis after 3 h or 6 h of H2O2 exposure to clarify the mechanism of phagocytosis. The maximum reduction of p-FAK and p-MerTK expression was observed 3 h and 6 h after H2O2 exposure, respectively (data not shown). Phosphorylated FAK was significantly reduced by H2O2 treatment, but photobiomodulation did not change the expression of FAK in comparison to the H2O2-exposed group (Figure 3A). In this point, we performed the statistical analysis between H2O2 only treated group and photobimodulation group. Although photobiomodulation did not change the expression of phosphorylated FAK, photobiomodulation improved the reduction of phosphorylated MerTK induced by the oxidative stress (Figure 3B). NAC at 1 nM increased the expression of phosphorylated FAK and MerTK.

Figure 3

Photobiomodulation increased the expression level of phosphorylated MerTK but not phosphorylated FAK. FAK and MerTK expression was measured by western blot. The quantification of the expression of phosphorylated FAK and phosphorylated MerTK was corrected

Photobiomodulation enhanced the phagocytic activity and increased the expression of phosphorylated MerTK

We investigated the phagocytosis activity and the expression of phosphorylated MerTK to validate our results concerning ARPE-19. The fluorescence intensity was significantly reduced after H2O2 exposure, and photobiomodulation enhanced the fluorescence intensity of intracellular POS in hRPE cells in comparison to the H2O2 only group (Figure 4A). In this point, we performed the statistical analysis between H2O2 only treated group and photobimodulation group. Furthermore, we investigated the expression of phosphorylated MerTK in hRPE cells. The expression of phosphorylated MerTK was increased in primary RPE cultures by photobiomodulation (Figure 4B).

Figure 4

Photobiomodulation enhanced the phagocytic activity in human retinal pigment epithelium cell cultures. A: Oxidative stress reduced the phagocytic activity, and photobiomodulation improved phagocytic activity induced by oxidative stress in hRPE cells.

Discussion

In the present study, as expected, phagocytic activity was reduced by exposure to H2O2 (Figure 1). The activity of RPE cells is reduced by oxidative stress and the auto-oxidative lipofuscin is accumulated in the lysosomes. In addition, drusen is formed in between the RPE and Bruch’s membrane. Ultimately, these things result in AMD [25,26]. The increase of oxidative stress also impairs the function of phagocytosis, and the dysfunction of phagocytosis induces the accumulation of lipofuscin [27,28].

Next, we investigated whether photobiomodulation using low-intensity and near-infrared light affects ARPE-19. Blue LED is routinely used in video display terminals and is known as an inducer of several kinds of photoreceptor cell damage in our laboratory [29]. In contrast, red LED has longer wavelengths than blue LED and has a protective effect on photoreceptors [22].

Near-infrared light photobiomodulation has a protective effect against light-induced retinal degeneration and reduced inflammation via the upregulation of mitochondrial cytochrome c oxidase expression in AMD mouse models [16,22]. Although photobiomodulation reduced the ROS production, it did not alter the cell viability or mitochondrial membrane potential (Figure 2). A previous report suggested that photobiomodulation has protective effects against high glucose-induced cell death of 661W cells (mouse photoreceptor cells) and retinal ganglion cells but not against high glucose-induced cell death of ARPE-19 cells [17]. This report also indicated that all cell lines, including ARPE-19, reduced the superoxide generation but did not change cytochrome c oxidase activity, which is related to mitochondrial activity. Furthermore, this phagocytosis assay model was set in a concentration of 0.1 mM H2O2, which did not change the cell death rate. Thus, low-intensity far-red light have no effects on cell viability or mitochondrial membrane potential.

Phagocytosis is related to FAK and MerTK expression. MerTK is an important protein in the ingestion of POS, and it has been shown that mutation of MerTK found in retinitis pigmentosa—one of the most common retinal diseases responsible for blindness—results in phagocytic dysfunction in RPE cells [30,31]. In the present study, we investigated the expression and phosphorylation of FAK and MerTK in POS exposed ARPE-19 cells to clarify the mechanism of phagocytosis enhancement with near-infrared photobiomodulation. Photobiomodulation increased phosphorylated MerTK but not phosphorylated FAK. Although photobiomodulation increased only the phosphorylated MerTK, the antioxidant NAC increased both phosphorylated FAK and MerTK. There are some difference pathway to increase the phagocytosis activity between photobiomodulation and antioxidant. A previous report suggested that mitochondrial dysfunction impairs the function of phagocytosis in retinal pigment epithelial cells [15]. Photobiomodulation may have a specific effect, which is the upregulation of phagocytosis activity through some mitochondrial pathways.

In conclusion, these findings indicate that photobiomodulation enhances phagocytosis via the MerTK-mediated upregulation of POS ingestion into RPE cells (Figure 5). Near-infrared light photobiomodulation may be a noninvasive, inexpensive, and easy adjunctive therapy to help inhibit the development of ocular diseases, such as AMD and retinitis pigmentosa. However, further experimentation and clinical studies are needed to clarify the therapeutic effects.

Figure 5

Photobiomodulation enhances phagocytosis via the upregulation of MerTK and has an anti-oxidative effect. Phagocytosis has several steps: binding to integrin, ingestion, and degradation of POS. FAK is thought to be involved in binding to integrin, and

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Articles from Molecular Vision are provided here courtesy of Emory University and the Zhongshan Ophthalmic Center, Sun Yat-sen University, P.R. China
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Photomed Laser Surg.  2014 Feb 14. [Epub ahead of print]

LowLevel Laser Therapy Improves Vision in a Patient with Retinitis Pigmentosa.

Ivandic BT1, Ivandic T.

Abstract

Abstract Objective: This case report describes the effects of lowlevel laser therapy (LLLT) in a single patient with retinitis pigmentosa (RP).

Background data: RP is a heritable disorder of the retina, which eventually leads to blindness. No therapy is currently available.

Methods: LLLT was applied using a continuous wave laser diode (780 nm, 10 mW average output at 292 Hz, 50% pulse modulation). The complete retina of eyes was irradiated through the conjunctiva for 40 sec (0.4 J, 0.333 W/cm2) two times per week for 2 weeks (1.6 J). A 55-year-old male patient with advanced RP was treated and followed for 7 years.

Results: The patient had complained of nyctalopia and decreasing vision. At first presentation, best visual acuity was 20/50 in each eye. Visual fields were reduced to a central residual of 5 degrees. Tritan-dyschromatopsy was found. Retinal potential was absent in electroretinography. Biomicroscopy showed optic nerve atrophy, and narrow retinal vessels with a typical pattern of retinal pigmentation. After four initial treatments of LLLT, visual acuity increased to 20/20 in each eye. Visual fields normalized except for a mid-peripheral absolute concentric scotoma. Five years after discontinuation of LLLT, a relapse was observed. LLLT was repeated (another four treatments) and restored the initial success. During the next 2 years, 17 additional treatments were performed on an “as needed” basis, to maintain the result.

Conclusions: LLLT was shown to improve and maintain vision in a patient with RP, and may thereby have contributed to slowing down blindness.

.

Eur J Ophthalmol 2011; 00(00)
Article Type:
DOI:10.5301/EJO.2011.8175

T. Ivandic

Abstract

Purpose: Retinitis pigmentosa (RP) is an inherited disorder of the retina, which ultimately leads to blindness. No therapy is available. This case report examined whether low-level laser therapy (LLLT) can help treat RP.
.
Methods: A 55-year-old patient presented at the ambulatory with difficulties in reading. Diagnosis revealed RP with typical symptomatology including hemeralopy and tritan-dyschromatopsy. Best visual acuity was 20/50 in both eyes. Visual fields were concentric and reduced to 5°. Electroretinography: b-wave abolished. Biomicroscopic examination showed an optic atrophy, attenuated retinal vessels with typical retinal pigmentation. After the patient had given his informed consent, LLLT was applied in compliance with the Declaration of Helsinki using a continuous-wave laser diode (780 nm, 10 mW, 292 Hz modulation, 3 mm2 spot size). The retina was irradiated from the exterior through the conjunctiva-sclera by guiding the beam exit at 1 cm distance above the eye ball with perpendicular anterior-posterior movements. The treatment lasted 40 sec (0.4 W/cm2) and was repeated 2 times per week for a total of 4 treatments (1.6 W/cm2). After 5 years without any therapy, the same treatment was repeated. Thereafter, during the subsequent 2 years, 17 additional treatments were performed at irregular time points.
.
Results: Visual acuity in both eyes increased from 20/50 at baseline to 20/20 after LLLT (4 initial treatments). Visual fields showed normalized outer limits with a mid-peripheral circular scotoma. After 5 years without any therapy, a relapse to the original condition was observed. After repeating LLLT (4 additional treatments), the condition improved again. By further sporadic individual treatments, the improved condition could be maintained for 2 years.
.
Conclusions: LLLT was shown to improve and maintain vision in a case with RP, and may thereby contribute to slowing down blindness.
.
.
Clin Immunol Immunopathol.  1992 Jul;64(1):78-83.

Systemic immunostimulation after retinal laser treatment in retinitis pigmentosa.

Williams LL, Shannon BT, Chambers RB, Leguire LE, Davidorf FH.

Source

Department of Ophthalmology, Ohio State University College of Medicine, Columbus.

Abstract

Systemic immunostimulation followed an experimental treatment trial of scatter argon laser photocoagulation directed to the retina of one eye of 10 patients with heredo-degenerative retinitis pigmentosa (RP). Significantly increased RP lymphocyte CD25, CD26, and CD4/CD26 activation epitope expressions over prelaser values and controls were found with a normalization of soluble interleukin-2 receptor secretion after laser treatment. Serum interferon-gamma was low both pre- and postlaser. Interestingly, when a panel of viral antibodies was tested, only those to rubella virus were elevated in the early postlaser period. The character of RP immunostimulation after laser-induced inflammation could be consistent with an antigenic stimulus from laser-released retinal proteins which might be of autoimmune or latent infectious origin. Enhanced immune responses may be a common but unrecognized sequellae of retinal laser.

 

 

Reflux Laryngitis

Lasers  Med Sci.  2013 Apr 24. [Epub ahead of print]

Potential anti-inflammatory effect of low-level laser therapy on the experimental reflux laryngitis: a preliminary study.

Marinho RR, Matos RM, Santos JS, Ribeiro MA, Ribeiro RA, Lima RC Jr, Albuquerque RL Jr, Thomazzi SM.

Source

Departamento de Fisiologia, Universidade Federal de Sergipe (UFS), 49100-000, São Cristóvão, Sergipe, Brazil.

Abstract

The most common cause of laryngitis is the laryngopharyngeal reflux disease. The symptoms of laryngitis can be hoarseness, globus, chronic cough, voice fatigue, throat pain, and dysphagia. Low-level laser therapy (LLLT) is beneficial to reduce the pain and inflammatory response without side effects. Therefore, LLLT may be a useful tool for the treatment of laryngitis. This study proposes to analyze the effect of laser therapy in a model of reflux-induced laryngitis. The animals were randomly put into three groups: control-non-intubated; nasogastric intubation-intubated; and nasogastric intubation with laser therapy-intubated treated with 105-J/cm2 laser irradiation. For the induction of laryngitis, the animals were anesthetized and a nasogastric tube was inserted through the nasopharynx until it reached the stomach, for 1 week. Thereafter, measurement of myeloperoxidase activity and the histopathological procedures were performed. In conclusion, we observed in this study that 105-J/cm2 infrared laser reduced the influx of neutrophils in rats, and it improved the reparative collagenization of the laryngeal tissues.

Laryngitis

Lasers  Med Sci.  2013 Apr 24. [Epub ahead of print]

Potential anti-inflammatory effect of low-level laser therapy on the experimental reflux laryngitis: a preliminary study.

Marinho RR, Matos RM, Santos JS, Ribeiro MA, Ribeiro RA, Lima RC Jr, Albuquerque RL Jr, Thomazzi SM.

Source

Departamento de Fisiologia, Universidade Federal de Sergipe (UFS), 49100-000, São Cristóvão, Sergipe, Brazil.

Abstract

The most common cause of laryngitis is the laryngopharyngeal reflux disease. The symptoms of laryngitis can be hoarseness, globus, chronic cough, voice fatigue, throat pain, and dysphagia. Low-level laser therapy (LLLT) is beneficial to reduce the pain and inflammatory response without side effects. Therefore, LLLT may be a useful tool for the treatment of laryngitis. This study proposes to analyze the effect of laser therapy in a model of reflux-induced laryngitis. The animals were randomly put into three groups: control-non-intubated; nasogastric intubation-intubated; and nasogastric intubation with laser therapy-intubated treated with 105-J/cm2 laser irradiation. For the induction of laryngitis, the animals were anesthetized and a nasogastric tube was inserted through the nasopharynx until it reached the stomach, for 1 week. Thereafter, measurement of myeloperoxidase activity and the histopathological procedures were performed. In conclusion, we observed in this study that 105-J/cm2 infrared laser reduced the influx of neutrophils in rats, and it improved the reparative collagenization of the laryngeal tissues.

Light Emitting Diodes – Abstracts linked to manuscripts

Facial Rejuvenation in the Triangle of ROS (2009)
Abstract: Recently, we introduced into the conventional catalogue of biological aging a new determinant: ordered interfacial water layers. The discovery of their tunability with skin-tolerated levels of 670 nm light inspired a model, which suggested that the light, by interaction with ordered interfacial water layers in the extracellular matrix, would reverse elastin degeneration. We validated the model in a 10 month self-experiment and arrived at an effective facial rejuvenation program. Importantly, during the experimental phase we avoided extreme oxidative stressors, in particular exposure to extensive ultraviolet and infrared radiation as well as air pollution. Here we report on the adaptation of our model to the extreme oxidative stress levels prevalent in numerous polluted megacities. The results of the extension comprise a new understanding of the protective function of the skin acid mantle, new predictive insight into effects of reactive oxygen species (ROS) on interfacial water layers, and their implication in processes of biological aging, including depletion of follicular stem cell reservoirs and telomere shortening, and led to the design of an accelerated skin rejuvenation method.

Effects of Low-Level Light Therapy on Hepatic Antioxidant Defense in Acute and Chronic Diabetic Rats (2009)
Abstract: Diabetes causes oxidative stress in the liver and other tissues prone to complications. Photobiomodulation by near infrared light (670 nm) has been shown to accelerate diabetic wound healing, improve recovery from oxidative injury in the kidney, and attenuate degeneration in retina and optic nerve. The present study tested the hypothesis that 670 nm photobiomodulation, a low-level light therapy, would attenuate oxidative stress and enhance the antioxidant protection system in the liver of a model of type I diabetes. MaleWistar rats were made diabetic with streptozotocin (50 mg/kg, ip) then exposed to 670 nm light (9 J/cm2) once per day for 18 days (acute) or 14 weeks (chronic). Livers were harvested, flash frozen, and then assayed for markers of oxidative stress. Light treatment was ineffective as an antioxidant therapy in chronic diabetes, but light treatment for 18 days in acutely diabetic rats resulted in the normalization of hepatic glutathione reductase and superoxide dismutase activities and a significant increase in glutathione peroxidase and glutathione-S transferase activities. The results of this study suggest that 670 nm photobiomodulationmay reduce, at least in part, acute hepatic oxidative stress by enhancing the antioxidant defense system in the diabetic ratmodel.

Near infrared light protects cardiomyocytes from hypoxia and reoxygenation injury by a nitric oxide dependent mechanism (2009)
Abstract: Photobiomodulation with near infrared light (NIR) provides cellular protection in various disease models. Previously, infrared light emitted by a low-energy laser has been shown to significantly improve recovery from ischemic injury of the canine heart. The goal of this investigation was to test the hypothesis that NIR (670 nm) from light emitting diodes produces cellular protection against hypoxia and reoxygenation-induced cardiomyocyte injury. Additionally, nitric oxide (NO) was investigated as a potential cellular mediator of NIR. Our results demonstrate that exposure to NIR at the time of reoxygenation protects neonatal rat cardiomyocytes and HL-1 cells from injury, as assessed by lactate dehydrogenase release and MTT assay. Similarly, indices of apoptosis, including caspase 3 activity, annexin binding and the release of cytochrome c from mitochondria into the cytosol, were decreased after NIR treatment. NIR increased NO in cardiomyocytes, and the protective effect of NIR was completely reversed by the NO scavengers carboxy- PTIO and oxyhemoglobin, but only partially blocked by the NO synthase (NOS) inhibitor L-NMMA. Mitochondrial metabolism, measured by ATP synthase activity, was increased by NIR, and NO-induced inhibition of oxygen consumption with substrates for complex I or complex IV was reversed by exposure to NIR. Taken together these data provide evidence for protection against hypoxia and reoxygenation injury in cardiomyocytes by NIR in a manner that is dependent upon NO derived from NOS and non-NOS sources.

Pretreatment with near-infrared light via light-emitting diode provides added benefit against rotenone- and MPP+-induced neurotoxicity (2008)
Abstract: Parkinson’s disease (PD) is a movement disorder caused by the loss of dopaminergic neurons in the substantia nigra pars compacta, leading to nigrostriatal degeneration. The inhibition of mitochondrial respiratory chain complex I and oxidative stress-induced damage have been implicated in the pathogenesis of PD. The present study used these specific mitochondrial complex I inhibitors (rotenone and 1-methyl-4-phenylpyridinium or MPP+) on striatal and cortical neurons in culture. The goal was to test our hypothesis that pretreatment with near-infrared light (NIR) via light-emitting diode (LED) had a greater beneficial effect on primary neurons grown in media with rotenone or MPP+ than those with or without LED treatment during exposure to poisons. Striatal and visual cortical neurons from newborn rats were cultured in a media with or without 200 nM of rotenone or 250 ?Mof MPP+ for 48 h. They were treated with NIR-LED twice a day before, during, and both before and during the exposure to the poison. Results indicate that pretreatment with NIR-LED significantly suppressed rotenone- or MPP+-induced apoptosis in both striatal and cortical neurons (P<0.001), and that pretreatment plus LED treatment during neurotoxin exposure was significantly better than LED treatment alone during exposure to neurotoxins. In addition, MPP+ induced a decrease in neuronal ATP levels (to 48% of control level) that was reversed significantly to 70% of control by NIR-LED pretreatment. These data suggest that LED pretreatment is an effective adjunct preventative therapy in rescuing neurons from neurotoxins linked to PD.

Modulation of rat pituitary growth hormone by 670 nm light (2008)
Abstract: In rat pituitary somatotrophs, cytochrome oxidase is co-packaged with growth hormone (GH) in some 20 storage granules. Because this enzyme is thought to be the molecular photoacceptor of red-near infrared 21 light, and because exposure of diverse tissue systems to 670 nm visible light affects their biological 22 responses (e.g., wound healing), we tested the idea that exposure of rat pituitary cells, rat hemi-pituitary 23 glands and rat pituitary homogenates to 670 nm light in vitro might alter GH storage and/or release. In 24 this report we offer evidence to show that light treatment (670 nm, 80 s, intensity 50 mW/cm2, energy 25 density 4 J/cm2) up-regulates GH release, in part by breakdown of intracellular, oligomeric GH as deter- 26 mined by gel filtration chromatography.

NEAR-INFRARED LIGHT VIA LIGHT-EMITTING DIODE TREATMENT IS THERAPEUTIC AGAINST ROTENONE- AND 1-METHYL-4- PHENYLPYRIDINIUM ION-INDUCED NEUROTOXICITY (2008)
Abstract: Parkinson’s disease is a common progressive neurodegenerative disorder characterized by the degeneration of dopaminergic neurons in the substantia nigra pars compacta. Mitochondrial dysfunction has been strongly implicated in the pathogenesis of Parkinson’s disease. Thus, therapeutic approaches that improve mitochondrial function may prove to be beneficial. Previously, we have documented that near-infrared light via light-emitting diode (LED) treatment was therapeutic to neurons functionally inactivated by tetrodotoxin, potassium cyanide (KCN), or methanol intoxication, and LED pretreatment rescued neurons from KCNinduced apoptotic cell death. The current study tested our hypothesis that LED treatment can protect neurons from both rotenone- and MPP+-induced neurotoxicity. Primary cultures of postnatal rat striatal and cortical neurons served as models, and the optimal frequency of LED treatment per day was also determined. Results indicated that LED treatments twice a day significantly increased cellular adenosine triphosphate content, decreased the number of neurons undergoing cell death, and significantly reduced the expressions of reactive oxygen species and reactive nitrogen species in rotenone- or MPP+-exposed neurons as compared with untreated ones. These results strongly suggest that LED treatment may be therapeutic to neurons damaged by neurotoxins linked to Parkinson’s disease by energizing the cells and increasing their viability.

Photobiomodulation for the Treatment of Retinal Injury and Retinal Degenerative Diseases (2008)
Abstract: Retinal injury and retinal degenerative diseases are a leading causes of visual impairment in the developed world. Mitochondrial dysfunction and oxidative stress play key roles in the pathogenesis of retinal injury and disease. The development and testing of strategies designed to improve mitochondrial function and attenuate oxidative stress are essential for combating retinal disease. One strategy involves the use of photobiomodulation. Photobiomodulation, low-energy photon irradiation by light in the far-red to nearinfrared (NIR) range using low energy lasers or light-emitting diode (LED) arrays, has been applied clinically in the treatment soft tissue injuries and acceleration of wound healing for more than 30 years. The therapeutic effects of photobiomodulation have been hypothesized to be mediated by intracellular signaling mechanisms triggered by the interaction of far-red to NIR photons with the mitochondrial photoacceptor molecule cytochrome oxidase which culminate in improved mitochondrial energy metabolism, increased synthesis of cytoprotective factors and cell survival.

PHOTOMODULATION OF CYTOCHROME OXIDASE (2006)
Objectives: Photobiomodulation by red to near infrared light is believed to activate mitochondrial respiratory chain components promoting cytoprotecton. Recent studies in our laboratory demonstrate that the action spectrum for stimulation of cytochrome oxidase activity and cellular ATP parallels the nearinfrared absorption spectrum of cytochome oxidase and that 660–680 nm irradiation upregulates cytochrome oxidase activity in cultured neurons. Methanol intoxication injures the retina and optic nerve. Via formic acid, a mitochondrial toxin of cytochrome oxidase. KCN (potassium cyanide) also poisons cytochrome oxidase, and has been used to assess the efficacy of 660– 680 nm irradiation for mitochondrial neuroprotection.

Embryonic Growth and Hatching Implications of Developmental 670-nm Phototherapy and Dioxin Co-exposure (2006)
Objective: We assessed the effect of 670-nm light therapy on growth and hatching kinetics in chickens (Gallus gallus) exposed to dioxin. Background Data: Photobiomodulation has been shown to stimulate signaling pathways resulting in improved energy metabolism, antioxidant production, and cell survival. In ovo treatment with 670-nm light-emitting diode (LED) arrays improves hatching success and increases hatchling size in control chickens. Under conditions where developmental dioxin exposure is above the lethality threshold (100 ppt), phototherapy attenuates dioxin-induced early embryonic death. We hypothesized that 670-nm LED therapy would attenuate dioxin-induced developmental anomalies and increase hatching success.

Stressed Cells Survive Better with Light (2002)
Abstract: Biostimulatory effects achieved in various biosystems irradiated with light lead us to recommend photobiostimulation for the compensation of external stress stimuli in tissue engineering, as well as in cellular imaging. Bioengineered cell assemblies and tissues are exposed to extreme environmental stress states during their transfer from artificial milieus into the body and in the first phase of their implantation. Similarly, cellular imaging via optical methods could represent a major stress impact to the biosystems examined, in particular, in temporally extended investigations. In both cases, an elevated and gradually proceeding environmental stress would inhibit cellular functions and enhance cell death.

Nature Inspired Hay Fever Therapy
Abstract: The survival oriented adaptation of evolved biosystems to variations in their environment is a selective optimization process. Recognizing the optimised end product and its functionality is the classical arena of bionic engineering. In a primordial world, however, the molecular organization and functions of prebiotic systems were solely defined by formative processes in their physical and chemical environment, for instance, the interplay between interfacial water layers on surfaces and solar light. The formative potential of the interplay between light (laser light) and interfacial water layers on surfaces was recently exploited in the formation of supercubane carbon nanocrystals. In evolved biosystems the formative potential of interfacial water layers can still be activated by light. Here we report a case of hay fever, which was successfully treated in the course of a facial rejuvenation program starting in November 2007. Targeting primarily interfacial water layers on elastin fibres in the wrinkled areas, we presumably also activated mast cells in the nasal mucosa, reported to progressively decrease in the nasal mucosa of the rabbit, when frequently irradiated. Hay fever is induced by the release of mediators, especially histamine, a process associated with the degranulation of mast cells. Decrease in mast cells numbers implies a decrease in the release of histamine. To the best of our knowledge this is the first report on the treatment of hay fever with visible light. This approach was inspired by bionic thinking, and could help ameliorating the condition of millions of people suffering from hay fever world wide.

From Microtornadoes to Facial Rejuvenation: Implication of Interfacial Water Layers
Abstract: Crystalline interfacial water layers have been observed at room temperature on both hydrophobic and hydrophilic surfaces – in air and subaquatically. Their implication in biology (and evolution) was postulated in a visionary paper in 1971 by Szent Gyo¨ rgyi. Today, they are believed to play a fundamental role in protein folding. A recent X-ray diffraction study reports on their presence on crystals in contact with their growth solution. Their subaquatic persistence on hydrophobic solids was reported in 2007. Their relevance in nanoscale phenomena is re?ected by the multidisciplinary focus in their study. In the course of a systematic exploration of interfacial water layers on solids we discovered microtornadoes, found a complementary explanation to the surface conductivity on hydrogenated diamond, and arrived at a practical method to repair elastin degeneration using light. The result was rejuvenated skin, reduced wrinkle levels, juvenile complexion, and lasting resilience.

Effects of Continuous-Wave (670-nm) Red Light on Wound Healing
Abstract: Recent work suggests that injuries can heal faster if treated by lasers emitting 670-nm red light. LED lights emitting 670-nm light are now available. This suggests that inexpensive and easyto- use 670-nm LED lights might help accelerate cutaneous wound healing. The objective was to evaluate the effect of 670-nm LED light on wound healing in SKH-1 hairless mice.

Biostimulatory Windows in Low-Intensity Laser Activation: Lasers, Scanners, and NASA’s Light-Emitting Diode Array System
Abstract: The purpose of this study was to assess and to formulate physically an irreducible set of irradiation parameters that could be relevant in the achieving reproducible light-induced effects in biological systems, both in vitro and in vivo.

Biostimulatory Windows in Low-Intensity Laser Activation: Lasers, Scanners, and NASA’s Light-Emitting Diode Array System
Abstract: This review presents current research on the use of far-red to near-infrared (NIR) light treatment in various in vitroand in vivomodels. Low-intensity light therapy, commonly referred to as “photobiomodulation,” uses light in the far-red to near-infrared region of the spectrum (630–1000 nm) and modulates numerous cellular functions. Positive effects of NIR–light-emitting diode (LED) light treatment include acceleration of wound healing, improved recovery from ischemic injury of the heart, and attenuated degeneration of injured optic nerves by improving mitochondrial energy metabolism and production.

DARPA Soldier Self Care: Rapid Healing of Laser Eye Injuries with Light Emitting Diode Technology
Abstract: Photobiomodulation by light in the red to near infrared range (630-1000 nm) using low energy lasers or light- emitting diode (LED) arrays has been shown to accelerate wound healing, improve recovery from ischemic injury and attenuate degeneration in the injured optic nerve. At the cellular level, photoirradiation at low fluences can generate significant biological effects including cellular proliferation and the release of growth factors from cells.

Effect of NASA Light-Emitting Diode Irradiation on Molecular Changes for Wound Healing in Diabetic Mice
Abstract: The purpose of this study was to assess the changes in gene expression of near-infrared light ther- apy in a modcl of impaired wound healing. Background Data: Light-Emitting Diodes (LED), originally devel- nped fnr NASA plant grrrwth experiments in space, show promise for delivering light deep into tissues of the body to promote wound healing and human tissue growth. In this paper we present the effects of LED treat- ment on wounds in a genetically diabetic mouse model.

Effect of NASA Light-Emitting Diode Irradiation on Wound Healing
Abstract: The purpose of this study was to assess the effects of hyperbaric oxygen (HBO) and near-infrared light therapy on wound healing. Background Data: Light-emitting diodes (LED), originally developed for NASA plant growth experiments in space show promise for delivering light deep into tissues of the body to pro- mote wound healing and human tissue growth. In this paper, we review and present our new data of LED treatment on cells grown in culture, on ischemic and diabetic wounds in rat models, and on acute and chronic wounds in humans.

Effects of 670-nm Phototherapy on Development
Abstract: The objective of the present study was to assess the survival and hatching success of chickens (Gallus gallus) exposed in ovoto far-red (670-nm) LED therapy. Background Data:Photobiomodulation by light in the red to near-infrared range (630–1000 nm) using low-energy lasers orlight-emitting diode (LED) arrays has been shown to accelerate wound healing and improve recovery from ischemic injury.

Evaluation of photodynamic therapy near functional brain tissue in patients with recurrent brain tumors
Abstract: Photodynamic therapy (PDT) involves the selective retention of a photosensitizer that upon activation with light mediates tumor cell destruction via the production of singlet oxygen. This study evaluates the toxicity of PDT and a new light-delivery device based on light-emitting diode (LED) technology in selected patients with brain tumors.

Innate immunity for biodefense: A strategy whose time has come
Abstract: Defense against biothreat agents requires a broad-spectrum approach. Modulation of the innate immune system might ful?ll this requirement. Hackett’s previous review of innate immune activation as a broad-spectrum biodefense strategy identi?ed several unresolved questions. The current article is a systematic approach to answering those questions with the focused participation of research groups developing this technology.

Light-emitting diode treatment reverses the effect of TTX on cytochrome oxidase in neurons
Abstract: Light close to and in the near-infrared range has documented benefits for promoting wound healing in human and animals. However, mechanisms of its action on cells are poorly undersottd. We hypothesied that light treatment with a light emitting diode array at 670nm (LED) is theraputic in stimulating cellular events involving increases in ctochrome oxidase activity.

Light-emitting Diodes as a Light Source for Intraoperative Photodynamic Therapy
Abstract: The development of more cost-effective light sources for photodynamic therapy of brain tumors would be of benefit for both research and clinical applications. In this study, the u se of light-emitting diode arrays for photodynamic therapy of brain tumors with Photofrin porfimer sodium was investigated.

Medical Applications of Space Light-Emitting Diode Technology – Space Station and Beyond
Abstract: Space light-emitting diode (LED) technology has provided medicine with a new tool capable of delivering light deep of the body, at wavelengths which are biologically optimal for cancer treatment and wound healing. This LED technology has already flown on Space Shuttle missions. and shows promise for wound healing applications of benefit to Space Station astronauts.

Mitochondrial signal transduction in accelerated wound and retinal healing by near-infrared light therapy
Abstract: Photobiomodulation by light in the red to near infrared range (630–1000 nm) using low energy lasers or light-emitting diode (LED) arrays has been shown to accelerate wound healing, improve recovery from ischemic injury in the heart and attenuate degeneration in the injured optic nerve. Recent evidence indicates that the therapeutic effects of red to near infrared light result, in part, from intracellular signaling mechanisms triggered by the interaction of NIR light with the mitochondrial photoacceptor molecule cytochrome c oxidase.

Second International Conference on Near-Field Optical Analysis:
Photodynamic Therapy & Photobiology Effects

Proceedings of the Second International Conference on NOA
Houston, Texas, USA
May 31 – June 1, 2001

NASA Light Emitting Diode Medical Applications From Deep Space to Deep Sea
Abstract: LED-technology developed for NASA plant growth experiments in space shows promise for delivering light deep into tissues of the body to promote wound healing and human tissue growth. We present the results of LED-treatment of cells grown in culture and the effects of LEDs on patients’ chronic and acute wounds. LED-technology is also biologically optimal for photodynamic therapy of cancer and we discuss our successes using LEDs in conjunction with light-activated chemotherapeutic drugs.

NASA Light-Emitting Diode Medical Program – Progress in Space Flight and Terrestrial Applications
Abstract: Studies on cells exposed to microgravity and hypergravity indicate that human cells need gravity to stimulate cell growth. As the gravitational force increases or decreases, the cell function responds in a linear fashion. This poses significant health risks for astronauts in long termspace flight. LED-technology developed for NASA plant growth experiments in space shows promise for delivering light deep into tissues of the body to promote wound healing and human tissue growth. This LED-technology is also biologically optomal for photodynamic therapy of cancer.

NASA Light-Emitting Diodes for the Prevention of Oral Mucositis in Pediatric Bone Marrow Transplant Patients
Abstract: The purpose of this study was to determine the effects of prophylactic near-infrared light therapy from light-emitting diodes (LEDs) in pediatric bone marrow transplant (BMT) recipients. Background Data: Oral mucositis (OM) is a frequent side effect of chemotherapy that leads to increased morbidity. Near- infrared light has been shown to produce biostimulatory effects in tissues, and previous results using near- infrared lasers have shown improvement in OM indices. However, LEDs may hold greater potential for clinical applications.

Photobiomodulation Directly Benefits Primary Neurons Functionally Inactivated by Toxins
Abstract: Far red and near infrared (NIR) light promotes wound healing, but the mechanism is poorly understood. Our previous studies using 670 nm light-emitting diode (LED) arrays suggest that cytochrome c oxidase, a pho- toacceptor in the NIR range, plays an important role in therapeutic photobiomodulation. If this is true, then an irreversible inhibitor of cytochrome c oxidase, potas- sium cyanide (KCN), should compete with LED and re- duce its beneficial effects. This hypothesis was tested on primary cultured neurons.

Photobiomodulation Partially Rescues Visual Cortical Neurons from Cyanide-induced Apoptosis
Abstract: Near-infrared light via light-emitting diode treatment has documented therapeutic effects on neurons functionally inactivated by tetrodotoxin or methanol intoxication. Light-emitting diode pretreatment also reduced potassium cyanide-induced cell death, but the mode of death via the apoptotic or necrotic pathway was unclear. The current study tested our hypothesis that light-emitting diode rescues neurons from apoptotic cell death.Possible mechanisms involve an acceleration of electron transfer in the respiratory chain and activation of photoacceptors, such as cytochrome oxidase, thus pointing to a particular role for mitochondria.

Preliminary Investigation into Light-Modulated Replication of Nanobacteria and Heart Disease
Abstract: The purpose of this preliminary study is to evaluate the effect of various wavelengths of light on nanobacteria (NB). Background Data: NB and mitochondria use light for biological processes. NB have been described as multifunctional primordial nanovesicles with the potential to utilize solar energy for replication. NB produce slime, a pro cess common to living bacteria. Slime release is an evolutionary important stress- dependent phenomenon increasing the survival chance of individual bacteria in a colony. In the cardiovascu- lar system, stress-induced bacterial colony formation may lead to a deposition of plaque.

Therapeutic photobiomodulation for methanol-induced retinal toxicity
Abstract: Methanol intoxication produces toxic injury to the retina and optic nerve, resulting in blindness. The toxic metabolite in methanol intoxication is formic acid, a mitochondrial toxin known to inhibit the essential mitochondrial enzyme, cytochrome oxidase. Photobiomodulation by red to near-IR radiation has been demonstrated to enhance mitochondrial activity and promote cell survival in vitro by stimulation of cytochrome oxidase activity.