The influence of emission parameters in Low Level Light Therapy (LLLT) on cellular responses is not yet fully understood. This study assessed the impact of various light delivery modes on collagen production in human primary fibroblast cultured in monolayers after three treatments with red light emitting diode illumination (630 nm, 8 J/cm²). Human type I collagen was measured in cell culture supernatants with procollagen Type I C-Peptide enzyme immunoassay. Results from this study demonstrated that specific μsec pulsing patterns had a more favorable impact on the ability of fibroblasts to produce collagen de novo than comparator conditions of continuous wave, pulsed 50% duty cycle, and millisecond pulsing domain (72 hours post baseline). The cascade of events leading to collagen production by red illumination may be explained by the photodissociation of nitric oxide from cytochrome c oxidase. Short and intermittent light delivery might enhance this cellular strategy.

Both local and systemic photon-induced changes in the circulation may be involved in the bioeffects of low-light therapy (LLT) including low level laser therapy (LLLT). Amplification of the direct effects of photon absorption may be due in part to changes induced by photons in immune cells while in transit through the dermal capillaries. The peripheral location of these capillaries makes their contents readily accessible to photons. The longer the duration of treatment, the greater will be the number of cells in transit that can be affected by photons. These cells and their secretions circulate around the body, increasing the range and duration of phototherapy. This amplification may be caused in part by indirect effects initiated in cells that have not absorbed photons by regulatory proteins such as cytokines secreted by cells that have absorbed photons. Direct and indirect photon-induced increases in both the microcirculation and the macrocirculation have been reported; examples of these are described. A circulation-based mechanism by which exposure of the scalp to photons can produce intracranial and extracranial changes is proposed.

Low level laser (or light) therapy (LLLT) has been clinically applied for many indications in medicine that require the following processes: protection from cell and tissue death, stimulation of healing and repair of injuries, and reduction of pain, swelling and inflammation. One area that is attracting growing interest is the use of transcranial LLLT to treat stroke and traumatic brain injury (TBI). The fact that near-infrared light can penetrate into the brain would allow non-invasive treatment to be carried out with a low likelihood of treatment-related adverse events. LLLT may have beneficial effects in the acute treatment of brain damage injury by increasing respiration in the mitochondria, causing activation of transcription factors, reducing key inflammatory mediators, and inhibiting apoptosis. We tested LLLT in a mouse model of TBI produced by a controlled weight drop onto the skull. Mice received a single treatment with 660-nm, 810-nm or 980-nm laser (36 J/cm2) four hours post-injury and were followed up by neurological performance testing for 4 weeks. Mice with moderate to severe TBI treated with 660- nm and 810-nm laser had a significant improvement in neurological score over the course of the follow-up and histological examination of the brains at sacrifice revealed less lesion area compared to untreated controls. Further studies are underway.

The role of pulsed - low repetition frequency electric potential was investigated in suppressing the metabolic activities of aggressive human brain cancer cells. Twenty four hours post exposure the glioblastomas were found to be significantly inhibited in their metabolic activity. The findings herein reveal a near complete inhibition of glioblastoma's metabolic activity through selective applications of low frequency pulsed electric potentials.

Discoveries are rapidly being made in multiple laboratories that shed "light" on the fundamental molecular and cellular mechanisms underlying the use of low level light therapy (LLLT) in vitro, in animal models and in clinical practice. Increases in cellular levels of respiration, in cytochrome c oxidase activity, in ATP levels and in cyclic AMP have been found. Increased expression of reactive oxygen species and release of nitric oxide have also been shown. In order for these molecular changes to have a major effect on cell behavior, it is likely that various transcription factors will be activated, possibly via different signal transduction pathways. In this report we compare and contrast the effects of LLLT in vitro on murine embryonic fibroblasts, primary cortical neurons, cardiomyocytes and bone-marrow derived dendritic cells. We also examined two human cell lines, HeLa cancer cells and HaCaT keratinocytes. The effects of 810-nm near-infra-red light delivered at low and high fluences were addressed. Reactive oxygen species generation, transcription factor activation and ATP increases are reported. The data has led to the hypothesis that cells with a high level of mitochondrial activity (mitochondrial membrane potential) have a higher response to light than cells with low mitochondrial activity.

Aim: To investigate effects of low level laser therapy (LLLT) on hair cell regeneration following gentamicin ototoxicity in organotypic culture of rat cochlea. Methods: Organotypic cultures of cochlea in culture medium were allowed to grow for 17 days (C group). The organotypic cultures were irradiated daily with 808 nm LD laser, at 28.8 J/ cm²(L group). The organotypic culture were exposed to 1 mM of gentamicin for 48 hr and allowed to recover (G group) or allowed to recover in the culture medium with daily LLLT at 28.8 J/ cm² (GL group) for 17 days. The cochleae were stained with FM1-43. The number of hair cells was counted in each group serially for 17 days. Results: While the C group kept on losing hair cells in vitro culture, the hair cells remained rather stationary in the L group. The number of hair cells revealed significantly larger number of hair cells in the L group compared to the C group (p=0.05). And the group × time interaction was also significant (p=0.04). That is, the number of hair cells in the C group showed decreasing tendency which was significantly different from the L group. In G group, the initial number of hair cells decreased to 37.2% of that of the gentamicin non-exposed groups. While the G group kept on losing hair cells, the number of hair cells increased in the GL group. The number of hair cells revealed significantly larger in the GL group (p=0.01) compared to G group. And the group × time interaction was also significant (p=0.01). Also, the number of hair cells in the GL group showed increasing tendency which was significantly different from the G group. Conclusion: These results suggest that LLLT promotes hair cell regeneration following gentamicin damage in cochlear explants.

Total ischemia of myocardium has been simulated on isolated hearts of rats. Effects of a low-power HeNe laser (λ=632.8 nm) and a fiber optic photo-luminescent radiation source of red light ( λ of the spectral peak is equal to 630 nm) on isolated heart contractile function characteristics and on lipid peroxidation (LPO) level in myocardium tissues have been investigated. Two groups of the specimens have been irradiated with red light during the postischemia (reperfusion) period of time. The first group has been treated with laser light and the second one with the luminescent radiation. More rapid restoration of the speed of contraction, of the force of contraction, of the relaxation speed and of the heart rate with respect to the data of the control group has been observed in both experimental groups. The similar tendency was observed in the laser treated specimens. The effects of fibrillation of myocardium of isolated hearts irradiated by lowpower He-Ne laser light were observed. These effects could be caused by the local light fluence rate excess in the interference pattern of laser light diffracted on the heart muscle structures.

This research evaluated the effect of the GaAlAs lasertherapy at the healing of surgical wounds produced in Wistar rats femurs few days before the beginning of the radiotherapy. For this, an orifice was artificially produced in the femur bone of the rats and they had been submitted to an external radiotherapy with a radioactive source of cobalt in the dosage of 3000 cGys. The experimental group received additionally seven sessions of 780 nm, 40 mW, 100 J/cm² or 5 J/cm² in four points around the surgical wound, at each 48 h, initiated at the day of the surgery. These animals had been sacrificed in three and five weeks. The results show that the number of osteocites (p< 0,0001) and Harvers channels (p< 0,0001) were significantly larger in the groups that had been radiated with laser during the experiment.

Bloodstream infections are potentially life-threatening diseases. They can cause serious secondary infections, and may result in endocarditis, severe sepsis or toxic-shock syndrome. Pseudomonas aeruginosa is an opportunistic pathogen and one of the most important etiological factors responsible for nosocomial infections, mainly in immuno-compromissed hosts, characteristic of patients with severe burns. Its multiresistance to antibiotics produces many therapeutic problems, and for this reason, the development of an alternative method to antibiotic therapy is needed. Photodynamic inactivation (PDI) may be an effective and alternative therapeutic option to prevent bloodstream infections in patients with severe burns. In this study we report the use of PDI to prevent bloodstream infections in mice with third-degree burns. Burns were produced on the back of the animals and they were infected with 10⁹ cfu/mL of multi-resistant (MR) P. aeruginosa. Fifteen animals were divided into 3 groups: control, PDT blue and PDT red. PDT was performed thirty minutes after bacterial inoculation using 10μM HB:La⁺³ and a light-emitting diode (LED) emitting at λ=460nm±20nm and a LED emitting at λ=645 nm±10nm for 120s. Blood of mice were colected at 7h, 10h, 15h, 18h and 22h pos-infection (p.i.) for bacterial counting. Control group presented 1×10⁴ cfu/mL in bloodstream at 7h p.i. increasing to 1×10⁶ at 22h, while mice PDT-treated did not present any bacteria at 7h; only at 22h p.i. they presented 1×10⁴cfu/mL. These results suggest that HB:La⁺³ associated to blue LED or red LED is effective to delay and diminish MR P.aeruginosa bloodstream invasion in third-degree-burned mice.

Stroke is the one of the leading causes of mortality in the United States, claiming 600,000 lives each year. Evidence suggests that near infrared (NIR) illumination has a beneficial effect on a variety of cells when these cells are exposed to adverse conditions. Among these conditions is the hypoxic state produced by acute ischemic stroke (AIS). To demonstrate the impact NIR Transcranial Laser Therapy (TLT) has on AIS in humans, a series of double blind, placebo controlled clinical trials were designed using the NeuroThera^(R) System (NTS). The NTS was designed and developed to treat subjects non-invasively using 808 nm NIR illumination. TLT, as it applies to stroke therapy, and the NTS will be described. The results of the two clinical trials: NeuroThera^(R) Safety and Efficacy Trial 1 (NEST-1) and NeuroThera^(R) Safety and Efficacy Trial 2 (NEST-2) will be reviewed and discussed.

In a follow-up clinical study to our previously published 2006 SPIE conference proceeding, we analyzed a cross-section of patients treated for a variety of knee problems that present at our Meditech Laser Rehabilitation Clinics on a daily basis. Of the 98 patients with knee pathologies included in this study, 63% presented with degenerative osteoarthritis. On average 11 treatments, each 30-45 minutes in duration, were administered for the individual patient resulting in a significant improvement rate in excess of 92%. Laser Therapy is active at both the cellular and systemic levels activating a variety of mechanisms including cartilage regeneration, DNA synthesis, improved microcirculation and an analgesic and anti-inflammatory effect.

Two chronic, traumatic brain injury (TBI) cases are presented, where cognitive function improved following treatment with transcranial light emitting diodes (LEDs). At age 59, P1 had closed-head injury from a motor vehicle accident (MVA) without loss of consciousness and normal MRI, but unable to return to work as development specialist in internet marketing, due to cognitive dysfunction. At 7 years post-MVA, she began transcranial LED treatments with cluster heads (2.1" diameter with 61 diodes each - 9x633nm, 52x870nm; 12-15mW per diode; total power, 500mW; 22.2 mW/cm2) on bilateral frontal, temporal, parietal, occipital and midline sagittal areas (13.3 J/cm2 at scalp, estimated 0.4 J/cm2 to brain cortex per area). Prior to transcranial LED, focused time on computer was 20 minutes. After 2 months of weekly, transcranial LED treatments, increased to 3 hours on computer. Performs nightly home treatments (now, 5 years, age 72); if stops treating >2 weeks, regresses. P2 (age 52F) had history of closed-head injuries related to sports/military training and recent fall. MRI shows fronto-parietal cortical atrophy. Pre-LED, was not able to work for 6 months and scored below average on attention, memory and executive function. Performed nightly transcranial LED treatments at home (9 months) with similar LED device, on frontal and parietal areas. After 4 months of LED treatments, returned to work as executive consultant, international technology consulting firm. Neuropsychological testing (post- 9 months of transcranial LED) showed significant improvement in memory and executive functioning (range, +1 to +2 SD improvement). Case 2 reported reduction in PTSD symptoms.

Introduction: The therapeutic modalities available for the conservative management of chronic lumbar pain included infrared laser therapy and underwater traction, which usefulness is not universally acknowledged. This study was intended to ascertain any beneficial impact of infrared laser therapy and weightbath treatment on the clinical parameters and quality of life of patients with lumbar discopathy. Material and methods: The study population comprised 54 randomised subjects. I. group of 18 patents received only infrared laser therapy to lumbar region and painful Valley points. II. group of 18 subjects each received underwater traction therapy of lumbar spine with add-on McKenzie exercise and iontophoresis. The remaining III. group treated with exercise and iontophoresis, served as control. VAS, Oswestry index, SF36 scores, range of motion, neurological findings and thermography were monitored to appraise therapeutic afficacy in lumbar discopathy. A CT or MRI scan was done at baseline and after 3 months follow-up. Result:Infrared laser therapy and underwater traction for discopathy achieved significant improvement of all study parameters, which was evident 3 months later. Among the controls, significant improvement of only a single parameter was seen in patients with lumbar discopathy. Conclusions: Infrared laser therapy and underwater traction treatment effectively mitigate pain, muscle spasms, enhance joint flexibility, and improve the quality of life of patients with lumbar discopathy.

Syntonic phototherapy is an application of clinical phototherapy that is not well known by most LLLT photobiomodulation researchers and clinicians in spite of its long history. This is because of three main reasons: this approach was beyond the limits of the "reasonable" scientific paradigm, it has not been well researched and it is used mainly by optometrists. Clinical and basic researcher in the last decades about light's impact on cells, tissues, blood, circadian rhythms and mood disorders has broadened the paradigm and increased the acceptance of light as a healing agent. Perhaps now is an appropriate time to describe Syntonic optometric phototherapy with the purpose of exciting research to validate and expand its use. Syntonics uses non-coherent, non-polarized, broad-band light delivered into the eyes to treat brain injury, headache, strabismus, eye pathology, learning disability, mood and developmental syndromes. The eyes permit direct, non-invasive application of light to the retinal blood supply and to non-visual, retinal photoreceptor systems that signal circadian and other brain centers. Patients look at prescribed colors for 20-minutes/day for twenty treatments. Visual field, pupil, and binocular testing, medical history and current symptoms determine the syntonic filter prescription. Presentation describes syntonic theory, phototherapy device, visual field and pupil tests and cases reports with pre- and post-data and case resolution.

The aim of this study was to evaluate the healing of 3^rd degree burn on diabetic rats submitted or not to treatment with Polarized Light. Diabetes mellitus (Streptozotocin, 60mg/kg) was induced on 45 male Wistar albinus rats and a third degree burn (1.5× 1.5cm) was created in the dorsum of each animal under general anesthesia. After a regular quarantine period, the animals were randomly distributed into three groups as follows: G1: control (no treatment, n =15); G2: Polarized Light (λ=400-2000nm, 20J/cm²) and G3: Polarized Light (λ=400-2000nm, 40J/cm²). The phototherapy performed on group G2 was Polarized Light dose 20J/cm² and G3 was Polarized Light dose 40J/cm² (Bioptron®, λ400-2000 nm, 40mW; 2.4J/cm² per minute; Φ ± 5.5 cm; Bioptron AG, Monchaltorf, Switzerland). The phototherapy started immediately post-burning and was repeated daily until the day before the animal death. The energy was applied transcutaneously respecting the focal distance of 10cm as recommended by the manufacturer. The dose was 20 or 40J/cm² (4min 15s or 8min.and 30s). At each time point chosen (7, 14, and 21 days post-burning) and following macroscopic examination, each animal was killed by an overdose of general anesthesia. Slides were stained with HE, Sirius Red, and CK AE1/AE3 antibody. Qualitative and semi-quantitative analyses were performed under light microscopy. The animals submitted to phototherapy (20J/cm²) showed significant differences on regards revascularization and epithelialization. The use of 20J/cm² was effective on improving the healing of third degree buns on diabetic animals at both early and late stages of the repair.

The aim of this study was to assess the influence of low-level laser therapy (LLLT) or polarized light (PL) in cutaneous wound healing of hypothyroid rats at dosages of 20 or 40J/cm². Bioestimulatory effects of Laser radiation and Polarized light are recognized alternative therapies to improve healing on systemic disease patients, but their usefulness in the improvement of hypothyroidism healing impairment is uncertain till date. Forty Wistar rats were used in this study. Hypothyroidism was propylthiouracil- induced. Standard excisional cutaneous wounds were created without suturing and LLLT (λ660nm, 30mW, φ 3mm) or PL (λ 400-2000nm, 40mW, φ 10mm) was applied every 48 hours up to seven days on experimental groups. The rats were killed on the eighth day when wound contraction was assessed. The healing features were evaluated by light microscopy (H/E and Sirius Red). The cutaneous wounds of hypothyroid rats showed delayed healing process characterized by reduced thickness of epithelial layers, incipient formation of disorganized collagen fibers and wound contraction to a lesser extent (FISHER, p=0.0276), when compared to the euthyroid group. The use of both the Laser and Polarized Light on hypothyroid rats increased the amount of fibroblasts and the thickness of collagen fibers, especially on the L 20J/cm² group. Euthyroid rats have still demonstrated more regular collagen fibers pattern than hypothyroid rats. It was therefore concluded that hypothyroidism delays wound healing and both Laser photobiomodulation and Polarized Light at 20j/cm² dosages had improved the healing process in hypothyroid rats.

The research work was carried out to study the effect of Oral and Intrathecal Monechma Ciliatum on antinociception and EEG readings in Wistar Rats. Traditionally the extract is given to women in labour believed to reduce pain and ease parturition, though past works show that it has oesteogenic and oxytotic effects. The rats were divided into 5 major groups. Group 1 served as oral control group while groups 2 and 3 served as oral experimental groups and were treated with 500mg/kg and 1000mg/kg monechma ciliatum respectively. Group 4 served as intrathecal control group treated with intrathecal dextrose and group 5 received 1000mg/kg Monechma Ciliatrum intrathecally. The antinociceptive effect was analysed using a Von Frey's aesthesiometer. Monechma Ciliatum showed significant antinociceptive effect both orally and intrathecally, although it had a greater effect orally and during the first 15 minutes of intrathecal administration. EEG readings were also taken for all the groups and there was a decrease in amplitude and an increase in frequency for high dose (1000mg/ml) experimental groups and the mid brain electrodes produced a change from theta waves (3.5 - 7 waves per second) to alpha waves (7.5 - 13 waves per second) as seen in relaxed persons and caused decreased amplitudes and change in distribution seen in beta waves. Properties similarly accentuated by sedativehypnotic drugs.

Studies using the rabbit small clot or rabbit large clot embolic stroke models (RSCEM and RLCEM respectively) allowed us to alter a single NILT variable while keeping all other variables constant to investigate the variable's effect on the rabbit's behavioral performance following embolization. In this paper we review results from multiple studies. Using the RSCEM, we found that Continuous Wave (CW) NILT significantly improves behavioral function when NILT is administered up to 6 hour post-embolization at 808nm; a durable effect that can last up to 21 days following a single treatment. Using the RLCEM we found that NILT did not significantly alter intracerebral hemorrhage (ICH) incidence following embolization, and since intravenous (IV) tissue plasminogen activator (tPA) is currently the primary treatment of acute ischemic stroke (AIS), we used the RLCEM to determine the safety profile of NILT in combination with tPA. IV tPA increased ICH incidence by 160%. NILT did not affect the tPA-induced increase in ICH. Lastly, since the cellular mechanism(s) involved in NILT-mediated neuroprotection have not been elucidated, we measured the effect of CW and Pulse Wave (PW) NILT on cortical adenosine triphosphate (ATP) content as an indicator of improved cellular energetics using the RSCEM. Embolization decreased cortical ATP content by 45% compared to naive rabbits, a decrease that was attenuated by CW NILT (p>0.05). Following PW NILT, delivering 5-35 times higher peak cortical irradiances than CW NILT, we measured larger increases in cortical ATP content. This is the first demonstration that NILT significantly increased cortical ATP content in embolized animals.