This PDF file contains the front matter associated with SPIE Proceedings Volume 7887, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.

In a series of experiments we investigated the extent to which coherence is preserved in tissue. We investigated whether the decrease in coherence length is dependent upon the coherence length of the illuminating light and possibly also if the light is polarized. We compared highly coherent light from a HeNe laser, and less coherent light from a semiconductor laser, in scattering media such as raw ground beef. We studied the laser speckle contrast after passing through 1 - 2 cm of meat. The conclusion is that the laser light is still coherent enough to form laser speckles after passing through a 2 cm thickness of meat.

In the past four decades numerous studies have reported the efficacy of low level light (laser) therapy (LLLT) as a treatment for diverse diseases and injuries. Recent studies have shown that LLLT can biomodulate processes in the central nervous system and has been extensively studied as a stroke treatment. However there is still a lack of knowledge on the effects of LLLT at the cellular level in neurons. The present study aimed to study the effect of 810 nm laser on several cellular processes in primary cortical neurons cultured from mouse embryonic brains. Neurons were irradiated with light dose of 0.03, 0.3, 3, 10 and 30 J/cm² and intracellular levels of reactive oxygen species, nitric oxide and calcium were measured. The changes in mitochondrial function in response to light were studied in terms of adenosine triphosphate (ATP) and mitochondrial membrane potential (MMP). Light induced a significant increase in calcium, ATP and MMP at lower fluences and a decrease at higher fluence. ROS was induced significantly by light at all light doses. Nitric oxide levels also showed an increase on treatment with light. The results of the present study suggest that LLLT at lower fluences is capable of inducing mediators of cell signaling process which in turn may be responsible for the biomodulatory effects of the low level laser. At higher fluences beneficial mediators are reduced but potentially harmful mediators are increased thus offering an explanation for the biphasic dose response.

Glycogen synthase kinase-3β (GSK-3β) is a critical activator of cell apoptosis induced by a diverse array of insults. However, the effects of GSK-3β on the human lung adenocarcinoma cell (ASTC-a-1) apoptosis induced by high fluence low-power laser irradiation (HF-LPLI) are not clear. Here, we showed that GSK-3β was constantly translocated from cytoplasm to nucleus and activated during HF-LPLI-induced cell apoptosis. In addition, we found that co-overexpression of YFP-GSK-3β and CFP-Bax in ASTC-a-1 cells accelerated both Bax translocations to mitochondria and cell apoptosis, compared to the cells expressed CFP-Bax only under HF-LPLI treatment, indicating that GSK-3β facilitated ASTC-a-1 cells apoptosis through acceleration mitochondrial translocation of Bax. Our results demonstrate that GSK-3β exerts some of its pro-apoptotic effects in ASTC-a-1 cells by regulating the mitochondrial localization of Bax, a key component of the intrinsic apoptotic cascade.

Antimicrobial photodynamic inactivation (APDI) is based on the utilization of substances that can photosensitize biological tissues and are capable of being activated in the presence of light. Cryptococcus neoformans is an yeast surrounded by a capsule composed primarily of glucoronoxylomannan that plays an important role in its virulence. This yeast causes infection on skin, lungs and brain that can be associated with neurological sequelae and neurosurgical interventions, and its conventional treatment requires prolonged antifungal therapy, which presents important adverse effects. The aim of this study was to evaluate the protective effect of Cryptococcus neoformans capsule against reactive oxygen species generated by APDI. Cryptococcus neoformans KN99α, which is a strain able to produce capsule, and CAP59 that does not present capsule production were submitted to APDI using methylene blue (MB), rose bengal (RB), and pL-ce6 as photosensitizers (PS). Then microbial inactivation was evaluated by counting colony form units following APDI and confocal laser scanning microscopy (CLSM) illustrated localization as well as the preferential accumulation of PS into the fungal cells. C. neoformans KN99α was more resistant to APDI than CAP59 for all PSs tested. CLSM showed incorporation of MB and RB into the cytoplasm and a preferential uptake in mitochondria. A nuclear accumulation of MB was also observed. Contrarily, pL-ce6 appears accumulated in cell wall and cell membrane and minimal florescence was observed inside the fungal cells. In conclusion, the ability of C. neoformans to form capsule enhances survival following APDI.

We assume that the effectiveness of phototherapy against microorganisms may be increased if together with the photosensitizer a photocatalyst will be used. It was found that the combination of TiO₂-nanoparticles and Brilliant Green at two-wavelength irradiation with blue (405 nm) and red (625 nm) light provides a strong antimicrobial effect on standard and clinical strains of Staphylococci.

Photodynamic antimicrobial chemotherapy (PACT) is based on the principal that microorganisms will be inactivated using a light source combined to a photosensitizing agent in the presence of oxygen. Oxidative damage of cell components occurs by the action of reactive oxygen species leading to cell death for microbial species. It has been demonstrated that PACT is highly efficient in vitro against a wide range of pathogens, however, there is limited information for its in vivo potential. In addition, it has been demonstrated that sublethal photodynamic inactivation may alter the virulence determinants of microorganisms. In this study, we explored the effect of sublethal photodynamic inactivation to the virulence factors of Candida albicans. Methylene Blue (MB) was used as photosensitizer for sublethal photodynamic challenge on C. albicans associated with a diode laser irradiation (λ=660nm). The parameters of irradiation were selected in causing no reduction of viable cells. The potential effects of PACT on virulence determinants of C. albicans cells were investigated by analysis of germ tube formation and in vivo pathogenicity assays. Systemic infection was induced in mice by the injection of fungal suspension in the lateral caudal vein. C. albicans exposed to sublethal photodynamic inactivation formed significantly less germ tube than untreated cells. In addition, mice infected with C. albicans submitted to sublethal PACT survived for a longer period of time than mice infected with untreated cells. The oxidative damage promoted by sublethal photodynamic inactivation inhibited virulence determinants and reduced in vivo pathogenicity of C. albicans.

High fluence low-power laser irradiation (HF-LPLI) is a new stimulus to trigger cell apoptosis. Recently, great efforts have been made to investigate the mechanism involved in it. Our results show that HF-LPLI induces cell apoptosis through a large amount of intracellular reactive oxygen species (ROS), especially a higher generation in mitochondria. These triggered ROS causes mitochondrial injury manifested by mitochondrial depolarization and cytochrome c release. Caspase-3 activation is a downstream event which executed cell apoptosis finally. In addition, we exclude caspase-8/Bid signaling pathway in HF-LPLI-induced cell apoptosis. However, another important Bcl-2 pro-apoptotic member Bax participates in the apoptotic process. Our result show that Bax is activated after the diffusion of mitochondrial transmembrane potential and cytochrome c release, suggesting that Bax does not affect outer mitochondrial membrane permeabilization (OMMP). We postulate that the activation of Bax is mediated by oxidative stress caused by laser irradiation through ROS/GSK-3β/Bax pathway. Further studies need to be performed to clarify the exactly mechanism involved in HF-LPLI induced cell apoptosis.

We carried out a histological analysis on surgical bone defects grafted or not with MTA, treated or not with LED, BMPs and GBR. We have used several models to assess the effects of laser on bone. Benefits of the isolated or combined use them on bone healing has been suggested. There is no previous report on their association with LED light. 90 rats were divided into 10 groups. On Groups II and I the defect were filled with the clot. On Group II, were further irradiated. On groups III-VI, defect was filled with MTA + Collagen gel (III); animals of group IV were further irradiated. On groups V and VI, the defects filled with the MTA were covered with a membrane. Animals of Group VI were further irradiated. On Groups VII and VIII a pool of BMPs was added to the MTA and was further irradiated. On groups IX and X, the MTA + BMP graft was covered with a membrane. On group X, the defect was further irradiated. LED (λ850 ± 10nm, 150mW, A= 0.5cm², 54s, 0.3W/cm², 16 J/cm²) was applied at 48 h intervals during 15 days. Specimens were taken, processed, cut and stained with H&E and Sirius red and underwent histological analysis. The results showed that MTA seemed not being affected by LED light. However, its use positively affected healing around the graft. It is concluded that MTA is not affected by the LED light due to it characteristics, but beneficial results with LED usage was found.

Previous studies have shown positive effects of Low level laser therapy (LLLT) on the repair of bone defects, but there are only a few that associates bone healing in the presence of a metabolic disorder as Diabetes Melitus and LLLT. The aim of this study was to assess histologically the effect of LLLT (AsGaAl), 780nm, 70mW, CW, Ø~0.4mm, 16J/cm² per session) on the repair of surgical defects created in the femur of diabetic and non-diabetic Wistar Albinus rats. Surgical bone defects were created in 60 animals divided into four groups of 15 animals each: Group C (non-diabetic - control); Group CL (non-diabetic + LLLT); Group CD (diabetic); Group CDL (diabetic + LLLT). The animals on the irradiated group received 16 J/cm² per session divided into four points around the defect, being the first irradiation immediately after surgery and repeated every 48h for 14 days. The animals were killed 15, 21 and 30 days after surgery. The results of the present investigation showed histological evidence of improved amount of collagen fibers at early stages of the bone healing (15 days) and increased amount of well organized bone trabeculae at the end of the experimental period (30 days) on irradiated animals, (diabetic and non-diabetic) compared to non irradiated ones. It is concluded that LLLT has a positive biomodulative effect on the healing process of bone defects, even when diabetes mellitus was present.

Presently, great importance has been given to Low Level Laser Therapy (LLLT) with the intent of promoting wound healing process. The present study was aimed to investigate the promotive effect of LLLT on full thickness excision wounds in Swiss albino mice using optical fiber probe based light device. Circular wounds of diameter 15 mm were illuminated with single exposure of various laser doses 1, 2, 3, 4, 6, 8 and 10 J/cm² along with appropriate controls. Further, an optimal dose of 2 J/cm² was applied to excision wounds at different post-wounding treatment schedules (0, 24 h and 48 h) to explicate the relations between treatment schedule and its tissue regeneration potential. Wound area, mean wound healing time along with hydroxyproline and glucosamine levels from wound ground tissue was assessed to evaluate the resultant photobiostimulatory outcome. Histological analysis was performed on day 10 of post-wounding. A significant increase in hydroxyproline (P< 0.001) and glucosamine levels (P< 0.01) were observed in 2 J/cm² irradiation group, which was also substantiated by histological findings. In conclusion, the present study demonstrated that the immediate irradiation of 2 J/cm² dose following wounding hasten the healing process compared to the unilluminated control.

Transcranial laser therapy (TLT) using a near-infrared energy laser system was tested in the 2x Tg amyloid precursor protein (APP) mouse model of Alzheimer's Disease (AD). TLT was administered 3 times/week at escalating doses, starting at 3 months of age, and was compared to a control group which received no laser treatment. Treatment sessions were continued for a total of six months. The brains were examined for amyloid plaque burden, Aβ peptides (Aβ_1-40 and Aβ_1-42 ), APP cleavage products (sAPPα, CTFβ) and mitochondrial activity. Administration of TLT was associated with a significant, dose-dependent reduction in amyloid load as indicated by the numbers of Aβ plaques. Levels of Aβ_1-40 and Aβ_1-42 levels were likewise reduced in a dose-dependent fashion. All TLT doses produced an increase in brain sAPPα and a decrease in CTFβ levels consistent with an increase in α-secretase activity and a decrease in β-secretase activity. In addition, TLT increased ATP levels and oxygen utilization in treated animals suggesting improved mitochondrial function. These studies suggest that TLT is a potential candidate for treatment of AD.

Aim: The aim of this study was to evaluate the effectiveness of the laser in the treatment of hyperemia (edema) as assessed by a TMJ Doppler on 22 consecutive joints showing TMJ Hyperemia. Materials and Methods: The hyperemia of the joint was first evaluated using a TMJ Doppler device (Great Lakes Orthodontic Products - Buffalo NY) and it was recorded as severe, moderate or mild. The DioBeam 830 low level laser (830nm, 150mw continuous wave laser with a 1 cm beam, manufactured by CMS Dental Copenhagen, Denmark); 16 J/cm² (8 J/cm² with mouth open and 8 J/cm² with the mouth closed). The treatment time was 2 minutes per joint. The hyperemia was assessed immediately following the treatment. Results: 22 joints have been evaluated on 16 patients. 12 had severe hyperemia, 9 had moderate hyperemia and 1 had mild hyperemia. All 22 joints showed complete resolution of the hyperemia immediately after laser therapy. There were no negative clinical results associated with the treatments.Conclusion: Low Level Laser Therapy (LLLT) was an effective tool in the treatment of hyperemia of the TMJ.

For the last decade we have been applying the principles of Low level laser therapy and have broadened the concept for practical use before and after treatment with surgical lasers. The purpose of this clinical presentation is to demonstrate how this concept has improved treatment outcomes. Cases treated in our dental practice will be demonstrated with the protocols used. A look at the science behind this concept will be examined in an effort to explain the results and to open discussion.

Muscle tissue is one of the most frequently affected by injury, whether during sports activities, or work activities. In this context, biochemical and biophysical resources have been studied to minimize the time of muscle regeneration. Among these, low intensity pulsed ultrasound (US) and low level laser therapy (LLLT) may be highlighted. Despite a series of evidences about the positive effects of these resources in the process of tissue regeneration, the cellular and morphological changes triggered by LLLT and U.S. are still largely unknown. Thus, the aim of this study was to investigate the effects of US and LLLT on muscle repair after cryolesion by means of histopathological analysis and immunohistochemistry for COX-2. A total of thirty five male Wistar rats were randomly distributed into 4 groups: intact control group; injured control group: muscle injured animals without any treatment; laser treated group: muscle injured animals treated with 830 nm laser and ultra-sound treated group: muscle injured animals treated with US. The treatments started 24 hours post-surgery and were performed during 6 sessions. The animals exposed to lasertherapy pointed out minor degenerative changes of muscle tissue. In the same way, exposure to ultrasound was able to reduce tissue injuries induced by cryolesion, but less intense than laser therapy. Strong COX-2 positive cells were found in rats submitted to cryolesion only, whereas COX-2 immunoexpression was lower in laser treated or ultrasound treated groups. In summary, this study reveals that both lasertherapy and ultrasound have positive effects on muscle repair in rats.

Low-power laser (He-Ne) irradiation (LPLI) has been found to modulate various biological effects, especially those involved in promoting cell proliferation and metabolic regulation. However, the underlying mechanisms that LPLI prevents human cell senescence remain undefined. Herein, we devised a model enabling cell senescence using D-galactose for two days then treat with or without LPLI(< 15J/cm²), and investigated whether LPLI delays cell senescent in human dermal fibroblasts cells (HDF-a). First in this study, using SA-β-gal staining, compared with control cell we detected a lower frequency of SA-β-gal staining under the treatment of LPLI. Moreover, we found the growth rates of cell with LPLI was higher using CCK-8 analysis. Additionally, we also found LPLI induced HDF-a entered the irreversible G1 arrest measured by flow cytometry system. Therefore, LPLI may promote cell proliferation by stimulating cell-cycle progression and delay human cell senescence. Taken together, Low-power laser irradiation delay HDF-a cells senescence provides new information for the mechanisms of biological effects of LPLI.

The deposition and accumulation of amyloid-β-peptide (Aβ) in the brain are considered a pathological hallmark of Alzheimer's disease(AD). Apoptosis is a contributing pathophysiological mechanism of AD. Low-power laser irradiation (LPLI), a non-damage physical therapy, which has been used clinically for decades of years, is shown to promote cell proliferation and prevent apoptosis. Recently, low-power laser irradiation (LPLI) has been applied to moderate AD. In this study, Rat pheochromocytoma (PC12) cells were treated with amyloid beta 25-35 (Aβ_25-35) for induction of apoptosis before LPLI treatment. We measured cell viability with CCK-8 according to the manufacture's protocol, the cell viability assays show that low fluence of LPLI (2 J/cm² ) could inhibit the cells apoptosis. Then using statistical analysis of proportion of apoptotic cells by flow cytometry based on Annexin V-FITC/PI, the assays also reveal that low fluence of LPLI (2 J/cm² ) could inhibit the Aβ-induced cell apoptosis. Taken together, we demonstrated that low fluence of LPLI (2 J/cm² ) could inhibit the Aβ-induced cell apoptosis, these results directly point to a therapeutic strategy for the treatment of AD through LPLI.

The aim of this study was to assess the effect of low- level laser therapy (LLLT) on fibroblast proliferation on wound repair of rats with Iron deficiency anemia since there is no reports on literature about this subject. Iron deficiency anemia was induced on 36 newborn rats then an excisional wound was created on the dorsum of the animals which were divided into four groups: (I) - non-anemic, (II) - Anemic, (III) - non-anemic + LLLT, (IV) Anemic+ LLLT. The animals in each group were sacrificed at 7, 14 and 21 days. Laser irradiation was performed on each group (λ660nm,40Mw,CW) by contact mode with a dose of 2,5J/ cm² in four points on the area of the wound and total of 10J/cm² per session. Data were evaluated by analysis of variance (ANOVA) followed by Paired t-test. The results showed LLLT was able to stimulate fibroblastic proliferation in rats with iron deficiency anemia at the 21st day while at control group (III) no statistically significant differences was found.

This work aimed to study histologically the effect of Laser or LED phototherapy on mast cells on cutaneous wounds of rats with iron deficiency. 18 rats were used and fed with special peleted iron-free diet. An excisional wound was created on the dorsum of each animal which were divided into: Group I - Control with anemia + no treatment; Group II - Anemia + Laser; Group III - Anemia + LED; Group IV - Healthy + no treatment; Group V - Healthy + Laser; Group VI - Healthy + LED. Irradiation was performed using a diode Laser (λ660nm, 40mW, CW, total dose of 10J/cm², 4X2.5J/cm²) or a RED-LED ( λ700nm, 15mW, CW, total dose of 10J/cm²). Histological specimens were routinely processed, cut and stained with toluidine blue and mast cell counts performed. No significant statistic difference was found between groups as to the number of degranulated, non-degradulated or total mast cells. Greater mean values were found for degranulated mast cells in the Anemia + LED. LED irradiation on healthy specimens resulted in a smaller number of degranulated mast cells. Our results leads to conclude that there are no significant differences in the number of mast cells seven days after irradiation following Laser or LED phototherapy.

The aim of this study was to evaluate, through Raman spectroscopy, the repair of complete tibial fracture in rabbits fixed with wire osteosynthesis - WO, treated or not with infrared laser light (λ 780nm, 50mW, CW) associated or not to the use of HATCP and GBR. Surgical fractures were created under general anesthesia (Ketamine 0.4ml/Kg IP and Xilazine 0.2ml/Kg IP), on the tibia of 15 rabbits that were divided into 5 groups and maintained on individual cages, at day/night cycle, fed with solid laboratory pelted diet and had water ad libidum. On groups II, III, IV and V the fracture was fixed with WO. Animals of groups III and V were grafted with hydroxyapatite + GBR technique. Animals of groups IV and V were irradiated at every other day during two weeks (16J/cm², 4 x 4J/cm²). Observation time was that of 30 days. After animal death the specimens were kept in liquid nitrogen for further analysis by Raman spectroscopy. Raman spectroscopy showed significant differences between groups (p<0.001). It is concluded that IR laser light was able to accelerate fracture healing and the association with HATCP and GBR resulted on increased deposition of calcium hydroxyapatite.

We aimed assess the effects of different energy densities of the association of red/IR laser light on the healing of cutaneous wounds infected Staphylococcus aureus. Background: Wound infection is the most common complication on healing wounds and cause both vascular and cellular responses on the tissue. Several therapeutics is used for improving wound healing including the use of different light sources, such as the Laser. Some energy densities present positive photobiological effects on the healing process. Material and Methods: 24 young adult male Wistar rats, under general anesthesia, had their dorsum shaven, cleaned and a 1 x 1cm cutaneous wound created with a scalpel and left without no suturing or dressings. The wounds were infected with Staphylococcus aureus and were randomly divided in 8 subgroups of 3 animals in each: Control, Group 10J/cm², Group 20J/cm², and Group 30J/cm², 7 and 14 days each group. Laser phototherapy was carried out with a diode (λ680nm/790nm, P= 30mW/40mW, CW, Laser, Ø = 3mm, PD=424mW/cm² and 566mW/cm², t=11.8/ 8.8 sec, E=0.35J) and started immediately after surgery and repeated at every other day during 7 days. Laser light was applied on 4 points around wounded area. The animals were killed at either 8th or 15th day after contamination. Specimens were taken, routinely cut and processed to wax, stained and underwent histological analysis. The results were statistically analyzed. Results: Both 20 and 30J/cm² caused intense collagen deposition at the end of the experimental time. But, when 20 J/cm² was used the fibers were also well organized. Conclusion: Our results indicate that irradiated subjects showed improved wound healing being the 20 J/cm² the energy the caused better histological response.

Photodynamic therapy with temperature control is a new approach for treatment of obesity and cellulite. Cell death can occur under the action of various physical, chemical and biological factors. Depending on the inductor, this is apoptosis or necrosis. These two forms of cell death differ on the biochemical and morphological levels. Biochemical changes occur quickly enough and it raises difficulties of their detection. One of the morphological characteristics of apoptosis is a decrease (contraction) of cells, and necrosis - an increase in the size of the cell (swelling). This attribute simply determined visually using a digital microscope. The program was designed using LabVEIW media, which allowed us to develop the software for providing interaction with the measuring and control equipment, data collection, processing and displaying the information and results of calculations and simulations for the individual cells and ensembles of cells, and, in general, to automate process.