Blue laser light increases perfusion of a skin flap via release of nitric oxide from hemoglobin

Positron Emission Tomography of Nitric Oxide by a Specific Radical-Generating Dihydropyridine Tracer

Nitric oxide (NO) plays a pivotal role as a biological signaling molecule, presenting challenges in its specific detection and differentiation from other reactive nitrogen and oxygen species within living organisms. Herein, a 18F-labeled (fluorine-18, t1/2 = 109.7 min) small-molecule tracer dimethyl 4-(4-(4-[18F]fluorobutoxy)benzyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate ([18F]BDHP) is developed based on the dihydropyridine scaffold for positron emission tomography (PET) imaging of NO in vivo. [18F]BDHP exhibits a highly sensitive and efficient C-C cleavage reaction specifically triggered by NO under physiological conditions, leading to the production of a 18F-labeled radical that is readily retained within the cells. High uptakes of [18F]BDHP are found within and around NO-generating cells, such as macrophages treated with lipopolysaccharide or benzo(a)pyrene. MicroPET/CT imaging of arthritic animal model mice reveals distinct tracer accumulation in the arthritic legs, showcasing a higher distribution of NO compared with the control legs. In summary, a specific radical-generating dihydropyridine tracer with a unique radical retention strategy has been established for the marking of NO in real-time in vivo.

Nonionizing Electromagnetic Irradiations; Biological Interactions, Human Safety

Human is usually exposed to environmental radiation from natural and man-made sources. Therefore, it is important to investigate the effects of exposure to environmental radiation, partly related to understanding and protecting against the risk of exposure to environmental radiation with beneficial and adverse impacts on human life. The rapid development of technologies causes a dramatic enhancement of radiation in the human environment. In this study, we address the biological effects caused by different fractions of non-ionizing electromagnetic irradiation to humans and describe possible approaches for minimizing adverse health effects initiated by radiation. The main focus was on biological mechanisms initiated by irradiation and represented protection, and safety approaches to prevent health disorders.

Wavelength-Dependent Effects of Photobiomodulation for Wound Care in Diabetic Wounds

Photobiomodulation, showing positive effects on wound healing processes, has been performed mainly with lasers in the red/infrared spectrum. Light of shorter wavelengths can significantly influence biological systems. This study aimed to evaluate and compare the therapeutic effects of pulsed LED light of different wavelengths on wound healing in a diabetic (db/db) mouse excision wound model. LED therapy by Repuls was applied at either 470 nm (blue), 540 nm (green) or 635 nm (red), at 40 mW/cm² each. Wound size and wound perfusion were assessed and correlated to wound temperature and light absorption in the tissue. Red and trend-wise green light positively stimulated wound healing, while blue light was ineffective. Light absorption was wavelength-dependent and was associated with significantly increased wound perfusion as measured by laser Doppler imaging. Shorter wavelengths ranging from green to blue significantly increased wound surface temperature, while red light, which penetrates deeper into tissue, led to a significant increase in core body temperature. In summary, wound treatment with pulsed red or green light resulted in improved wound healing in diabetic mice. Since impeded wound healing in diabetic patients poses an ever-increasing socio-economic problem, LED therapy may be an effective, easily applied and cost-efficient supportive treatment for diabetic wound therapy.

Changes in Cell Biology under the Influence of Low-Level Laser Therapy

Low-level laser therapy (LLLT) has become an important part of the therapeutic process in various diseases. However, despite the broad use of LLLT in everyday clinical practice, the full impact of LLLT on cell life processes has not been fully understood. This paper presents the current state of knowledge concerning the mechanisms of action of LLLT on cells. A better understanding of the molecular processes occurring within the cell after laser irradiation may result in introducing numerous novel clinical applications of LLLT and potentially increases the safety profile of this therapy.

Phototoxicity-free blue light for enhancing therapeutic angiogenic efficacy of stem cells

Low-level light therapy (LLLT) is a safe and noninvasive technique that has drawn attention as a new therapeutic method to treat various diseases. However, little is known so far about the effect of blue light for LLLT due to the generation of reactive oxygen species (ROS) that can cause cell damage. We introduced a blue organic light-emitting diode (bOLED) as a safe and effective light source that could generate a low amount of heat and luminance compared to conventional light sources (e.g., light-emitting diodes). We compared phototoxicity of bOLED light with different light fluences to human adipose-derived stem cells (hADSC). We further explored molecular mechanisms involved in the therapeutic efficacy of bOLED for enhancing angiogenic properties of hADSC, including intracellular ROS control in hADSCs. Using optimum conditions of bOLED light proposed in this study, photobiomodulation and angiogenic properties of hADSCs were enhanced. These findings might open new methods for using blue light in LLLT. Such methods can be implemented in future treatments for ischemic disease.

Blue Light in Dermatology

Phototherapy is an important method of dermatological treatments. Ultraviolet (280-400 nm) therapy is of great importance; however, there are concerns of its long-term use, as it can lead to skin aging and carcinogenesis. This review aims to evaluate the role and the mechanism of action of blue light (400-500 nm), a UV-free method. The main mediators of cellular responses to blue light are nitric oxide (NO) and reactive oxygen species (ROS). However, the detailed mechanism is still not fully understood. It was demonstrated that blue light induces an anti-inflammatory and antiproliferative effect; thus, it may be beneficial for hyperproliferative and chronic inflammatory skin diseases such as atopic dermatitis, eczema, and psoriasis. It was also found that blue light might cause the reduction of itching. It may be beneficial on hair growth and may be used in the treatment of acne vulgaris by reducing follicular colonization of Propionibacterium acnes. Further studies are needed to develop accurate protocols, as the clinical effects depend on the light parameters as well as the treatment length. There are no major adverse effects observed yet, but long-term safety should be monitored as there are no studies considering the long-term effects of blue light on the skin.

The impact of photobiomodulation on the chondrogenic potential of adipose-derived stromal/stem cells

Due to their capacity to differentiate into the chondrogenic lineage, adipose-derived stromal/stem cells (ASC) are a promising source of therapeutically relevant cells for cartilage tissue regeneration. Their differentiation potential, however, varies between patients. In our study, we aim to stimulate ASC towards a more reliable chondrogenic phenotype using photobiomodulation (PBM). LED devices of either blue (475 nm), green (516 nm) or red (635 nm) light were used to treat human ASC from donors of varying chondrogenic potential. The treatment was applied either once during the 2D expansion phase or repeatedly during the 3D differentiation phase. Chondrogenic differentiation was assessed via pellet size, GAG/DNA content, histology and gene expression analysis. Reactions to PBM were found to be wavelength-dependent and more pronounced when the treatment was applied during expansion. Donors were assigned to responder categories according to their response to the treatment during expansion, whereby good responders were mainly donors with low intrinsic chondrogenic potential. Exposed to light, they revealed a particularly high relative increase in pellet size (more than twice the size of untreated controls after red light PBM), intense collagen type II immunostaining (low/absent in untreated controls) and activation of otherwise absent COL2A1 expression. Conversely, on a donor with high intrinsic chondrogenic potential, light had adverse effects. When applied with shorter wavelengths (blue, green), it led to reduced pellet size, GAG/DNA content and collagen type II immunostaining. However, when PBM was applied in 3D, the same donor was the only one to react with increased differentiation to all three wavelengths. We were able to demonstrate that PBM can be used to enhance or hamper chondrogenesis of ASC, and that success depends on treatment parameters and intrinsic cellular potential. The improvement of chondrogenesis in donors with low intrinsic potential highlights PBM as potent tool for cell-based cartilage regeneration. Its cost-effectiveness and ease of use make for an attractive treatment option to enhance the performance of ASC in cartilage tissue engineering.

Postconditioning With Red-Blue Light Therapy Improves Survival of Random Skin Flaps in a Rat Model

BACKGROUND

Random skin flap ischemic necrosis is a serious challenge in reconstructive surgery. Photobiomodulation is a noninvasive effective technique to improve microcirculation and neovascularization. Photobiomodulation with red or blue light has been separately proven to partially prevent skin flap necrosis, but the synergistic effect of red and blue light not been elucidated. Our experiment evaluated the impact of postconditioning with red-blue light therapy on the viability of random flaps.

METHODS

Thirty Sprague-Dawley male rats (male, 12 weeks) with a cranially based random pattern skin flap (3 × 8 cm) were divided into 3 groups: control group, red light group, and red-blue light group. On postoperative day 7, flap survival was observed and recorded using transparent graph paper, flaps were obtained and stained with hematoxylin and eosin, and microvessel density was measured. Micro-computed tomography was used to measure vascular volume and vascular length. On days 0, 3, and 7 after surgery, blood flow was measured by laser Doppler. To investigate the underlying mechanisms, the amount of nitric oxide (NO) metabolites in the flap tissue was assessed on days 3, 5, and 7 after surgery.

RESULTS

The mean percentage of skin flap survival was 59 ± 10% for the control group, 69 ± 7% for the red light group, and 79 ± 9% for the red-blue light group (P < 0.01). The microvessel density was 12.3 ± 1.2/mm2 for the control group, 31.3 ± 1.3/mm2 for the red light group, and 36.5 ± 1.4/mm2 for the red-blue light group (P < 0.01). Both vascular volume and total length in the red-blue light group showed significantly increased compared with the red light and control group (P < 0.01). Blood flow in the red-blue light treated flap showed significantly increased at postsurgery days 3 and 7 compared with the red light and control group (P < 0.01). The level of the NO metabolites was significantly increased in flap tissues belonging to the red-blue light group compared with the other 2 groups (P < 0.01).

CONCLUSIONS

This study showed that postconditioning with red-blue light therapy can enhance the survival of random skin flap by improving angiogenesis and NO releasing.

Overview of Artificial Intelligence Applications in Chinese Medicine Therapy

To evaluate the importance of AI technologies in modernizing traditional Chinese medicine (TCM) therapy, this article presents the systematic review of the relevant literature and explains the beneficial effects of AI technology on the TCM treatment outcomes from the experience of famous and veteran Chinese medicines, including acupuncture, Tui Na massage, and Qigong practitioners. This study also focuses on the urgent necessity to apply AI technologies to develop therapeutic models on the theme “treating the disease before it happens.” Furthermore, the study also discusses the major bottlenecks and future prospects for the development of intelligent TCM treatment strategies.

Antivirale Photodynamische Therapie bei Covid-19: Ein neuer Ansatz zur Behandlung in frühen Krankheitsstadien

Aufgrund der weiterhin akuten Covid-19-Pandemie wurde in der hier präsentierten Studie untersucht, ob die Photodynamische Therapie (PDT) mit Riboflavin (Vitamin B2) und einem speziell entwickelten Laser/LED-Behandlungsset eingesetzt werden kann, um an Covid-19 erkrankte Patienten in frühen Krankheitsstadien therapieren zu können.

Alle 20 Patienten in der Versuchsgruppe zeigten innerhalb der 5 Tage der PDT-Behandlung eine signifikante Verbesserung der klinischen Symptome sowie eine Reduktion der Viruslast. 14 von 20 Patienten hatten bereits nach 5 Tagen der Behandlung mit PDT einen negativen QPCR-Test, während die anderen 6 Patienten ebenfalls eine signifikant reduzierte Viruslast aufwiesen. 20 Patienten in der Kontrollgruppe mit konventioneller Versorgung wurden innerhalb von 5 Tagen 3-mal getestet und es konnte keine signifikante Verbesserung festgestellt werden, weder klinisch noch bei der Beurteilung der Viruslast.

Die angewandte Behandlung ist einfach zu Hause durchführbar und kosteneffektiv. Sie kann zur Vorbeugung nach Kontakt mit infizierten Personen oder bei positivem Test, aber auch in frühen Fällen mit leichten bis mittelschweren klinischen Symptomen eingesetzt werden.

Electromedical devices in wound healing management: a narrative review

Wound healing is the sum of physiological sequential steps, leading to skin restoration. However, in some conditions, such as diabetes, pressure ulcers (PU) and venous legs ulcers (VLU), healing is a major challenge and requires multiple strategies. In this context, some electromedical devices may accelerate and/or support wound healing, modulating the inflammatory, proliferation (granulation) and tissue-remodelling phases. This review describes some helpful electromedical devices including: ultrasonic-assisted wound debridement; electrotherapy; combined ultrasound and electric field stimulation; low-frequency pulsed electromagnetic fields; phototherapy (for example, laser therapy and light-emitting diode (LED) therapy); biophotonic therapies, and pressure therapies (for example, negative pressure wound therapy, and high pressure and intermittent pneumatic compression) The review focuses on the evidence-based medicine and adequate clinical trial design in relation to these devices.

Effect of the topical Klox fluorescence biomodulation system on the healing of canine surgical wounds

OBJECTIVE

To determine the effect of the Klox fluorescence biomodulation system (Phovia) on the healing of surgical wounds.

STUDY DESIGN

Prospective, blinded, controlled clinical trial.

SAMPLE POPULATION

Healthy dogs undergoing orthopedic surgery (n = 10).

METHODS

Half of the length of each surgical wound was treated with Phovia, and the remaining 50% was treated with saline solution on the first day after surgery and every 3 days until day 13. Wound healing of treated and control areas within each wound was evaluated via macroscopic assessment and histological and immunohistochemical analysis of treated and control wounds.

RESULTS

The areas treated with Phovia achieved lower histology scores (P = .001), consistent with complete re-epithelialization, less inflammation of the dermal layer, and greater and more regular deposition of collagen. According to immunohistochemistry, expression of factor VIII, epidural growth factor, decorin, collagen III, and Ki67 was increased in treated compared with untreated tissues.

CONCLUSION

Phovia therapy improved re-epithelialization, decreased dermal inflammation, and improved matrix formation in uncomplicated cutaneous incisional wounds by regulating the expression of key biological mediators.

CLINICAL SIGNIFICANCE

Phovia may be a beneficial adjunct to promote the healing of incisional wounds.

Effect of Modified Laser Transcutaneous Irradiation on Pain and Quality of Life in Patients with Diabetic Neuropathy

Background: Diabetic neuropathy (DN) is one of the major complications developed by individuals with diabetes mellitus. DN is responsible for a high morbidity and mortality rate and impacts the public health and medical assistance resources. Intradermic laser irradiation on blood (ILIB) consists of the application of light beams on the radial arterial, providing anti-inflammatory and vasodilator effects, antiarrhythmic action, reduction of glucose, and stabilization of the hormonal and immunological systems. These effects help to maintain the physiological dynamics of the body. Objective: The goal of this research was to evaluate the effects of ILIB to relieve pain and improve the quality of life in DN patients. The sample comprised 30 diabetic volunteers with DN, randomly distributed into 3 groups: Control-conventional treatment; ILIB-100 mW, 660 ± 10 nm, 30 applications in total, divided into 3 stages of 10 applications, 30 min each, daily, with a 20-day interval between each stage; SILIB-same protocol described for ILIB, with the equipment switched off. Before and after the application of the therapeutic protocols, all volunteers were evaluated by the following instruments: Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), visual analog scale, Leeds Assessment of Neuropathic Symptoms and Signs (LANSS), and PAIN DETECT scale. Collected data were statistically analyzed with a 95% confidence interval, p < 0.05. Results: The ILIB group presented significantly lower pain levels and a better quality of life compared with the control and SILIB groups. Conclusions: This study demonstrated that ILIB therapy was effective in reducing pain and improving quality of life in patients with DN.

Photobiomodulation (PBM) promotes angiogenesis in-vitro and in chick embryo chorioallantoic membrane model

The application of light in various therapeutic settings known as Photobiomodulation (PBM) is well established. Indications are the improvement of wound healing and tissue regeneration, scarring, and perfusion as well as pain therapy. Tissue perfusion is mandatory for successful wound healing. Nevertheless, there is a lack of mechanistic studies. We investigate the potential effect of PBM from light emitting diodes (LED) at 635 nm, 80 mW/cm², 24 J/cm² on angiogenesis in a two-part study: 1.) Investigation of the effect of PBM on the proliferation of endothelial cells and on vasculogenesis in a co-culture model of endothelial cells and stem cells. 2.) Investigation of the influence of PBM at chick egg chorioallantoic membrane (CAM) assays with fresh human skin xenografts. In both study phases, we observed a stimulating effect of PBM at 635 nm; in part 1: for proliferation of HUVEC (human umbilical vein endothelial cells) (25833 ± 12859 versus 63002 ± 35760 cells/well, p < 0.05, for cellular network formation (2.1 ± 2.1 versus 4.6 ± 3.5, p < 0.05) and for less cell compactness p = 0.01; in part 2: for the increase of number of vessel junctions per ROI (region of interest) (15.9 ± 2.6 versus 20.8 ± 5.4, p < 0.05). Our results suggest significant promotion of angiogenesis by PBM at 635 nm in vitro and in vivo.

Blue light exposure decreases systolic blood pressure, arterial stiffness, and improves endothelial function in humans

AIMS

Previous studies have shown that ultraviolet light can lead to the release of nitric oxide from the skin and decrease blood pressure. In contrast to visible light the local application of ultraviolet light bears a cancerogenic risk. Here, we investigated whether whole body exposure to visible blue light can also decrease blood pressure and increase endothelial function in healthy subjects.

METHODS

In a randomised crossover study, 14 healthy male subjects were exposed on 2 days to monochromatic blue light or blue light with a filter foil (control light) over 30 minutes. We measured blood pressure (primary endpoint), heart rate, forearm vascular resistance, forearm blood flow, endothelial function (flow-mediated dilation), pulse wave velocity and plasma nitric oxide species, nitrite and nitroso compounds (secondary endpoints) during and up to 2 hours after exposure.

RESULTS

Blue light exposure significantly decreased systolic blood pressure and increased heart rate as compared to control. In parallel, blue light significantly increased forearm blood flow, flow-mediated dilation, circulating nitric oxide species and nitroso compounds while it decreased forearm vascular resistance and pulse wave velocity.

CONCLUSION

Whole body irradiation with visible blue light at real world doses improves blood pressure, endothelial function and arterial stiffness by nitric oxide released from photolabile intracutanous nitric oxide metabolites into circulating blood.

Computational Structural Biology of S-nitrosylation of Cancer Targets

Nitric oxide (NO) plays an essential role in redox signaling in normal and pathological cellular conditions. In particular, it is well known to react in vivo with cysteines by the so-called S-nitrosylation reaction. S-nitrosylation is a selective and reversible post-translational modification that exerts a myriad of different effects, such as the modulation of protein conformation, activity, stability, and biological interaction networks. We have appreciated, over the last years, the role of S-nitrosylation in normal and disease conditions. In this context, structural and computational studies can help to dissect the complex and multifaceted role of this redox post-translational modification. In this review article, we summarized the current state-of-the-art on the mechanism of S-nitrosylation, along with the structural and computational studies that have helped to unveil its effects and biological roles. We also discussed the need to move new steps forward especially in the direction of employing computational structural biology to address the molecular and atomistic details of S-nitrosylation. Indeed, this redox modification has been so far an underappreciated redox post-translational modification by the computational biochemistry community. In our review, we primarily focus on S-nitrosylated proteins that are attractive cancer targets due to the emerging relevance of this redox modification in a cancer setting.

A feasibility study of a novel low-level light therapy for digital ulcers in systemic sclerosis

Background: Locally acting, well-tolerated treatments for systemic sclerosis (SSc) digital ulcers (DUs) are needed.

Objectives: Our primary aim was to investigate the safety, feasibility, and tolerability of a novel low-level light therapy (LTTT). A secondary aim was to tentatively assess efficacy.

Methods: A custom-built device comprising infrared (850 nm), red (660 nm), and violet (405 nm) LEDs was utilized. DUs were irradiated with 10 J/cm² twice weekly for 3 weeks, with follow-up at weeks 4 and 8. Any safety concerns were documented. Patient opinion on time to deliver, feasibility, and pain visual analogue score (VAS; 0–100, 100 most severe) was collected. Patient and clinician DU global assessment VAS were documented. DUs were evaluated by laser Doppler perfusion imaging pre- and post-irradiation.

Results: In all, 14 DUs in eight patients received a total of 46 light exposures, with no safety concerns. All patients considered LTTT ‘took just the right amount of time’ and was ‘feasible’, with a low associated mean pain VAS of 1.6 (SD: 5.2). Patient and clinician global DC VAS improved during the study (mean change: –7.1 and –5.2, respectively, both p < .001). DU perfusion significantly increased post-irradiation.

Conclusions: LTTT for DUs is safe, feasible, and well tolerated. There was an early tentative suggestion of treatment efficacy.

Effects of Laser Radiation on Mitochondria and Mitochondrial Proteins Subjected to Nitric Oxide

The biological roles of heme and nonheme nitrosyl complexes in physiological and pathophysiological conditions as metabolic key players are considered in this study. Two main physiological functions of protein nitrosyl complexes are discussed—(1) a depot and potential source of free nitric oxide (NO) and (2) a controller of crucial metabolic processes. The first function is realized through the photolysis of nitrosyl complexes (of hemoglobin, cytochrome c, or mitochondrial iron–sulfur proteins). This reaction produces free NO and subsequent events are due to the NO physiological functions. The second function is implemented by the possibility of NO to bind heme and nonheme proteins and produce corresponding nitrosyl complexes. Enzyme nitrosyl complex formation usually results in the inhibition (or enhancement in the case of guanylate cyclase) of its enzymatic activity. Photolysis of protein nitrosyl complexes, in this case, will restore the original enzymatic activity. Thus, cytochrome c acquires peroxidase activity in the presence of anionic phospholipids, and this phenomenon can be assumed as a key step in the programmed cell death. Addition of NO induces the formation of cytochrome c nitrosyl complexes, inhibits its peroxidase activity, and hinders apoptotic reactions. In this case, photolysis of cytochrome c nitrosyl complexes will reactivate cytochrome c peroxidase activity and speed up apoptosis. Control of mitochondrial respiration by NO by formation or photolytic decay of iron–sulfur protein nitrosyl complexes is an effective instrument to modulate mitochondrial metabolism. These questions are under discussion in this study.

Effects of Photobiomodulation Therapy on Oxidative Stress in Muscle Injury Animal Models: A Systematic Review

This systematic review was performed to identify the role of photobiomodulation therapy on experimental muscle injury models linked to induce oxidative stress. EMBASE, PubMed, and CINAHL were searched for studies published from January 2006 to January 2016 in the areas of laser and oxidative stress. Any animal model using photobiomodulation therapy to modulate oxidative stress was included in analysis. Eight studies were selected from 68 original articles targeted on laser irradiation and oxidative stress. Articles were critically assessed by two independent raters with a structured tool for rating the research quality. Although the small number of studies limits conclusions, the current literature indicates that photobiomodulation therapy can be an effective short-term approach to reduce oxidative stress markers (e.g., thiobarbituric acid-reactive) and to increase antioxidant substances (e.g., catalase, glutathione peroxidase, and superoxide dismutase). However, there is a nonuniformity in the terminology used to describe the parameters and dose for low-level laser treatment.

The impact of wavelengths of LED light-therapy on endothelial cells

Low level light therapy receives increasing interest in the fields of tissue regeneration and wound healing. Several in vivo studies demonstrated the positive effects of LLLT on angiogenesis. This study aimed to investigate the underlying properties in vitro by comparing the effects of light therapy by light emitting diodes of different wavelengths on endothelial cells in vitro. Human umbilical vein endothelial cells were treated with either 475 nm, 516 nm or 635 nm light. Control cells were not illuminated. 2D proliferation was quantified by manual counting. HUVEC migration was analyzed by performing a 2D wound scratch assay and a 3D bead assay. The influence of LLLT on early vasculogenic events was determined in a 3D fibrin co-culture model with adipose-derived stem cells. Stimulation with both red and green pulsed LED light significantly increased HUVEC proliferation and 3D migration. Moreover, HUVEC showed increased 2D migration potential with green light stimulation. The treatment with blue light was ineffective. Several parameters showed that green light was even more potent to stimulate proliferation and migration of endothelial cells than clinically well-established red light therapy. Further studies have to focus on intracellular mechanisms induced by different wavelengths in order to optimize this promising therapy in tissue regeneration.

The Effect of Combination of Red, Infrared and Blue Wavelengths of Low-Level Laser on Reduction of Abdominal Girth: A Before-After Case Series

Introduction: The objective of this study was to assess the efficacy of a combination of 3 wavelengths (including red, infra-red, and blue) of low-level laser (LLL) as a non-invasive therapeutic method to reduce abdominal girth. To achieve biochemical activity on adipocytes, a red laser was used in our selective laser combination. Near-infrared laser was used to increase depth of penetration. Nitrosyl complexes of hemoglobin (NO-Hb) are sensitive to blue light, thereby leading to increase in release of biologically active nitric oxide (NO), which can affect tissue perfusion. Thus, a blue LED was added to the laser combination. Methods: Eighteen females participated in the study. Twelve sessions of laser therapy were performed, 2 sessions per week for each subject. Continuous wave diode lasers, including red (630 nm), infra-red (808 nm), and a blue LED (450 nm) were applied and were all designed by the Canadian Optic and Laser Center. Results: Statistical analyses revealed that upper abdomen size significantly decreased from pre- (91.86 ± 11.16) to post- (87.41 ± 10.52) low-level laser therapy (LLLT) (P<0.001). Middle abdomen size showed significant reduction from pre- (97.02 ± 8.82) to post- (91.97 ± 8.49) LLLT (P<0.001). Lower abdomen size significantly decreased from pre- (100.36 ± 9.45) to post- (95.80 ± 8.52) LLLT (P<0.001). Conclusion: Based on this case series pilot investigation, the combination of 3 different wavelengths of LLL was effective for abdominal girth reduction in 100% of our subjects (P<0.001), without any side effects. Future studies will assess the long-term benefits of this laser combination for reduction of subcutaneous fat deposits.

Alterations in nitric oxide homeostasis during traumatic brain injury

Changes in nitric oxide (NO) levels have been often associated with various forms of trauma, including secondary damage after traumatic brain injury (TBI). Several studies demonstrate the upregulation of NO synthase (NOS) enzymes, and concomitant increases in brain NO levels, which contribute to the TBI-associated glutamate cytotoxicity, including the pathogenesis of mitochondrial dysfunction. TBI is also associated with elevated NO levels in remote organs, indicating that TBI can induce systemic changes in NO regulation, which can be either beneficial or detrimental. Here we review the possible mechanisms responsible for changes in NO metabolism during TBI. Better understanding of the changes in NO homeostasis in TBI will be necessary to design rational therapeutic approaches for TBI. This article is part of a Special Issue entitled: Immune and Metabolic Alterations in Trauma and Sepsis edited by Dr. Raghavan Raju.

Phototherapy with LED light modulates healing processes in an in vitro scratch-wound model using 3 different cell types

BACKGROUND

An effective way of modulating wound healing processes, including proliferation and apoptosis, is low-level light therapy. Because of several disadvantages of lasers, light-emitting diodes (LEDs) could be more feasible light sources.

OBJECTIVE

To evaluate and compare the effects of blue and red light from LEDs on different cell types in an in vitro scratch-wound model.

METHODS

Monolayers of C2C12 myoblasts, NIH/3T3 fibroblasts, and BICR10 keratinocytes were injured by mechanical scraping. Cells were illuminated on 5 consecutive days for 10 minutes by LED at 470 or 630 nm. Effects of light on in vitro wound healing were evaluated by analyzing time to closure, proliferation, apoptosis, and necrosis rates.

RESULTS

Illumination substantially affected cell viability and cell growth. Blue light strongly decreased proliferation and augmented apoptosis in all 3 cell types and increased necrosis rates in C2C12 and NIH/3T3 cells. In contrast, red light did not alter apoptosis in either cell type but promoted proliferation in all 3 cell types with significant effects in C2C12 and NIH/3T3 cells and shortened time to closure in all 3 cell types.

CONCLUSION

Light-emitting diode light illumination could be a therapeutic option and positively affect wound healing processes. By choosing appropriate wavelengths, variable effects can be achieved.

Blue-violet light irradiation dose dependently decreases carotenoids in human skin, which indicates the generation of free radicals

In contrast to ultraviolet and infrared irradiation, which are known to facilitate cutaneous photoaging, immunosuppression, or tumour emergence due to formation of free radicals and reactive oxygen species, potentially similar effects of visible light on the human skin are still poorly characterized. Using a blue-violet light irradiation source and aiming to characterize its potential influence on the antioxidant status of the human skin, the cutaneous carotenoid concentration was measured noninvasively in nine healthy volunteers using resonance Raman spectroscopy following irradiation. The dose-dependent significant degradation of carotenoids was measured to be 13.5% and 21.2% directly after irradiation at 50 J/cm² and 100 J/cm² (P < 0.05). The irradiation intensity was 100 mW/cm². This is above natural conditions; the achieved doses, though, are acquirable under natural conditions. The corresponding restoration lasted 2 and 24 hours, respectively. The degradation of cutaneous carotenoids indirectly shows the amount of generated free radicals and especially reactive oxygen species in human skin. In all volunteers the cutaneous carotenoid concentration dropped down in a manner similar to that caused by the infrared or ultraviolet irradiations, leading to the conclusion that also blue-violet light at high doses could represent a comparably adverse factor for human skin.

Low level light therapy by LED of different wavelength induces angiogenesis and improves ischemic wound healing

BACKGROUND AND OBJECTIVE

Low-level light therapy (LLLT) has been revealed as a potential means to improve wound healing. So far, most studies are being performed with irradiation in the red to near-infrared spectra. Recently, we showed that blue light (470 nm) can significantly influence biological systems such as nitric oxide (NO) metabolism and is able to release NO from nitrosyl-hemoglobin or mitochondrial protein complexes. Therefore, the aim of this study was to evaluate and compare the therapeutic value of blue or red light emitting diodes (LEDs) on wound healing in an ischemia disturbed rodent flap model.

STUDY DESIGN/MATERIALS AND METHODS

An abdominal flap was rendered ischemic by ligation of one epigastric bundle and subjected to LED illumination with a wavelength of 470 nm (blue, n = 8) or 629 nm (red, n = 8) each at 50 mW/cm(2) and compared to a non-treated control group (n = 8). Illumination was performed for 10 minutes on five consecutive days.

RESULTS

LED therapy with both wavelengths significantly increased angiogenesis in the sub-epidermal layer and intramuscularly (panniculus carnosus muscle) which was associated with significantly improved tissue perfusion 7 days after the ischemic insult. Accordingly, tissue necrosis was significantly reduced and shrinkage significantly less pronounced in the LED-treated groups of both wavelengths.

CONCLUSIONS

LED treatment of ischemia challenged tissue improved early wound healing by enhancing angiogenesis irrespective of the wavelength thus delineating this noninvasive means as a potential, cost effective tool in complicated wounds.

Are the mitochondrial respiratory complexes blocked by NO the targets for the laser and LED therapy?

Effects of laser (442 and 532 nm) and light-emitting diode (LED) (650 nm) radiation on mitochondrial respiration and mitochondrial electron transport rate (complexes II-III and IV) in the presence of nitric oxide (NO) were investigated. It was found that nitric oxide (300 nM-10 μM) suppresses mitochondrial respiration. Laser irradiation of mitochondria (442 nm, 3 J cm(-2)) partly restored mitochondrial respiration (approximately by 70 %). Irradiation with green laser (532 nm) or red LED (650 nm) in the same dose had no reliable effect. Evaluation of mitochondrial electron transport rate in complexes II-III and IV and effects of nitric oxide demonstrated almost similar sensitivity of complex II-III and IV to NO, with approximately 50 % inhibition at NO concentration of 3 μM. Subsequent laser or LED irradiation (3 J cm(-2)) showed partial recovery of electron transport only in complex IV and only under irradiation with blue light (442 nm). Our results support the hypothesis of the crucial role of cytochrome c oxidase (complex IV) in photoreactivation of mitochondrial respiration suppressed by NO.

Effects of low-level laser therapy on mitochondrial respiration and nitrosyl complex content

Among the photochemical reactions responsible for therapeutic effects of low-power laser radiation, the photolysis of nitrosyl iron complexes of iron-containing proteins is of primary importance. The purpose of the present study was to compare the effects of blue laser radiation on the respiration rate and photolysis of nitrosyl complexes of iron-sulfur clusters (NO-FeS) in mitochondria, subjected to NO as well as the possibility of NO transfer from NO-FeS to hemoglobin. It was shown that mitochondrial respiration in State 3 (V3) and State 4 (V4), according to Chance, dramatically decreased in the presence of 3 mM NO, but laser radiation (λ = 442 nm, 30 J/cm(2)) restored the respiration rates virtually to the initial level. At the same time, electron paramagnetic resonance (EPR) spectra showed that laser irradiation decomposed nitrosyl complexes produced by the addition of NO to mitochondria. EPR signal of nitrosyl complexes of FeS-clusters, formed in the presence of 3 mM NO, was maximal in hypoxic mitochondria, and disappeared in a dose-dependent manner, almost completely at the irradiation dose 120 J/cm(2). EPR measurements showed that the addition of lysed erythrocytes to mitochondria decreased the amount of nitrosyl complexes in iron-sulfur clusters and produced the accumulation of NO-hemoglobin. On the other hand, the addition of lysed erythrocytes to mitochondria, preincubated with nitric oxide, restored mitochondrial respiration rates V3 and V4 to initial levels. We may conclude that there are two possible ways to destroy FeS nitrosyl complexes in mitochondria and recover mitochondrial respiration inhibited by NO: laser irradiation and ample supply of the compounds with high affinity to nitric oxide, including hemoglobin.

Yes, there is deqi sensation in laser acupuncture

Deqi, a composite of unique sensations, is essential for clinical efficacy according to Traditional Chinese Medicine. It is described as a sensory perception of varying character and is mostly ascribed to metal needle acupuncture. However, it can also be elicited by different kinds of laser acupuncture stimulation. This short paper summarizes the current scientific status of deqi in laser stimulation. Different kinds of laser acupuncture are described in a comprehensive form, and the most interesting studies concerning deqi and laser acupuncture are presented.

Intravenous laser blood irradiation, interstitial laser acupuncture, and electroacupuncture in an animal experimental setting: preliminary results from heart rate variability and electrocorticographic recordings

This is the first study to investigate intravenous (i.v.) laser blood irradiation, interstitial (i.st.) laser acupuncture, and electroacupuncture (EA) in combination with heart rate variability (HRV) and electrocorticogram. We investigated 10 male anesthetized Sprague-Dawley rats under the three conditions mentioned previously in Beijing, China, and data analysis was performed in Graz, Europe. For i.v. laser stimulation in the femoral vein and i.st. laser acupuncture at Neiguan (PC6), we used a European system (Modulas needle, Schwa-Medico, Germany; 658 nm, 50 mW, continuous wave mode), and for EA at Neiguan, a Chinese system (Hanshi-100A; Nanjing Jisheng Medical Technology Company, China; 15 Hz, 1 mA). HR, HRV, and electrocorticogram were recorded using a biophysical amplifier AVB-10 (Nihon-Kohden, Japan). HR changed significantly during i.st. laser acupuncture stimulation of Neiguan in anesthetized rats. Total HRV increased insignificantly during i.v. and i.st. laser stimulation. The LF/HF ratio showed significant changes only during i.v. laser blood irradiation. Integrated cortical EEG (electrocorticogram) decreased insignificantly during EA and i.v. laser blood irradiation. Further studies concerning dosage-dependent alterations are in progress.

A metabolomic study on the effect of intravascular laser blood irradiation on type 2 diabetic patients

Intravenous laser blood irradiation (ILBI) is widely applied in the treatment of different pathologies including diabetes mellitus. The aim of this study is to evaluate the effects of ILBI on the metabolites of blood in diabetic type 2 patients using metabolomics. We compared blood samples of nine diabetic type 2 patients, using metabolomics, before and after ILBI with blue light laser. The results showed significant decrease in glucose, glucose 6 phosphate, dehydroascorbic acid, R-3-hydroxybutyric acid, L-histidine, and L-alanine and significant increase in L-arginine level in blood and blood sugar in the patients have reduced significantly (p < 0.05). This study clearly demonstrated a significant positive effect of ILBI on metabolites of blood in diabetic type 2 patients. These findings support the therapeutic potential of ILBI in diabetic patients.

Blue 405 nm laser light mediates heart rate - investigations at the acupoint Neiguan (Pe.6) in Chinese adults

BACKGROUND

In previous studies, we showed that laser needle acupuncture with red and infrared light has specific effects on bio-signals of the brain and heart.

AIMS

In this publication we report the effect of blue laser light on heart rate and heart rate variability (HRV) before, during and after acupuncture at the acupoint Neiguan (Pe.6) in Chinese adults. These are the first data published concerning heart rate and HRV, obtained with blue laser acupuncture equipment.

PATIENTS AND METHODS

The investigations were carried out in 13 healthy Chinese volunteers with a mean age of 31.2 ± 7.5 years within a randomized, controlled study. Stimulation was performed with painless blue laser light (wavelength: 405 nm; activation: 10 minutes) bilaterally at Pe.6. In a second session, for control reasons the laser was not activated.

RESULTS

Heart rate showed a significant (p=0.008) decrease during blue laser light stimulation. In contrast, no significant changes were found when the laser was deactivated. The evaluation parameter LF/HF ratio (low frequency/high frequency ratio) from the HRV spectral analysis showed a very slight increase during stimulation, however it was not significant.

CONCLUSIONS

Our main conclusion is that continuous blue laser light stimulation on Neiguan significantly reduces heart rate of Chinese adults.

Integrative laser medicine and high-tech acupuncture at the medical university of graz, austria, europe

At the moment, modernization of acupuncture has a high priority. On the traditional side, acupuncture has only recently been awarded the status of Intangible Cultural Heritage by the UNESCO. On the innovative side, high-tech acupuncture is a registered trademark in Austria. Acupuncture has been used for medical treatment for thousands of years. A large number of empirical data are available but the technical quantification of effects was not possible up to now. Using electroacupuncture, needle, or laser stimulation and modern biomedical techniques, it was possible for the first time to quantify changes in biological activities caused by acupuncture. This paper which serves as introduction for the special issue "High-Tech Acupuncture and Integrative Laser Medicine" of the present journal, focuses on the latest innovative aspects that underline the further enhancement and development of acupuncture. Special emphasis is given to new methodological and technical investigations, for example, results obtained from all kinds of acupuncture innovations (e.g., teleacupuncture) and integrative laser medicine.

Mitochondrial dysfunction and biogenesis: do ICU patients die from mitochondrial failure?

Mitochondrial functions include production of energy, activation of programmed cell death, and a number of cell specific tasks, e.g., cell signaling, control of Ca²⁺ metabolism, and synthesis of a number of important biomolecules. As proper mitochondrial function is critical for normal performance and survival of cells, mitochondrial dysfunction often leads to pathological conditions resulting in various human diseases. Recently mitochondrial dysfunction has been linked to multiple organ failure (MOF) often leading to the death of critical care patients. However, there are two main reasons why this insight did not generate an adequate resonance in clinical settings. First, most data regarding mitochondrial dysfunction in organs susceptible to failure in critical care diseases (liver, kidney, heart, lung, intestine, brain) were collected using animal models. Second, there is no clear therapeutic strategy how acquired mitochondrial dysfunction can be improved. Only the benefit of such therapies will confirm the critical role of mitochondrial dysfunction in clinical settings. Here we summarized data on mitochondrial dysfunction obtained in diverse experimental systems, which are related to conditions seen in intensive care unit (ICU) patients. Particular attention is given to mechanisms that cause cell death and organ dysfunction and to prospective therapeutic strategies, directed to recover mitochondrial function. Collectively the data discussed in this review suggest that appropriate diagnosis and specific treatment of mitochondrial dysfunction in ICU patients may significantly improve the clinical outcome.

Light therapy by blue LED improves wound healing in an excision model in rats

BACKGROUND

Low level light therapy (LLLT) is an attractive alternative to enhance wound healing. So far most studies are performed with red or infrared irradiation. However, we recently showed that blue light (470 nm) can significantly influence biological systems, improving perfusion by release of nitric oxide from nitrosyl complexes with haemoglobin in a skin flap model in rats. Here, we compared the effects of blue and red low level light by light-emitting diodes (LEDs) on in vivo wound healing in an excision wound model in rats.

METHODS

Circular excision wounds were surgically created on the dorsum of each rat. Excisions on either the left or right side were illuminated post-OP and on five consecutive days for 10 min by LED at 470 nm or 630 nm with an intensity of 50 mW/cm(2),while protecting the contralateral side from exposure. In the control group, neither side was illuminated. On day 7 post-OP, we analysed planimetric and histological parameters, as well as expression of keratin-1, keratin-10 and keratin-17 on mRNA level.

RESULTS

Illumination substantially influenced wound healing. Blue light significantly decreased wound size on day 7, which correlated with enhanced epithelialisation. Light also affected mRNA expression. Both wavelengths decreased keratin-1 mRNA on day 7 post-OP, while keratin-10 mRNA level was elevated in both light treated group compared to control. Keratin-17 mRNA was also elevated in the red light group, but was unchanged in the blue light group.

CONCLUSION

In contrast to previous studies, we showed that also blue light significantly influences wound healing. Furthermore, our data suggest that light therapy can play an important role in normotrophic wound healing by affecting keratin expression. Illumination would provide an easily applicable, safe and cost-effective treatment of surface wounds.

Parallel evolution of nitric oxide signaling: diversity of synthesis and memory pathways

The origin of NO signaling can be traceable back to the origin of life with the large scale of parallel evolution of NO synthases (NOSs). Inducible-like NOSs may be the most basal prototype of all NOSs and that neuronal-like NOS might have evolved several times from this prototype. Other enzymatic and non-enzymatic pathways for NO synthesis have been discovered using reduction of nitrites, an alternative source of NO. Diverse synthetic mechanisms can co-exist within the same cell providing a complex NO-oxygen microenvironment tightly coupled with cellular energetics. The dissection of multiple sources of NO formation is crucial in analysis of complex biological processes such as neuronal integration and learning mechanisms when NO can act as a volume transmitter within memory-forming circuits. In particular, the molecular analysis of learning mechanisms (most notably in insects and gastropod molluscs) opens conceptually different perspectives to understand the logic of recruiting evolutionarily conserved pathways for novel functions. Giant uniquely identified cells from Aplysia and related species precent unuque opportunities for integrative analysis of NO signaling at the single cell level.

Modernization of traditional acupuncture using multimodal computer-based high-tech methods-recent results of blue laser and teleacupuncture from the Medical University of Graz

Basic and clinical research in traditional Chinese and Korean acupuncture has been performed at the Research Unit of Biomedical Engineering in Anesthesia and Intensive Care Medicine and the Traditional Chinese Medicine Research Center at the Medical University of Graz since 1997. This publication focuses on the latest innovative aspects that underline the further enhancement and development of acupuncture. In this context, novel biomedical and neuroscientific methods are of paramount importance for the fast and efficient modernization of the ancient Asian healing method. Traditional and future oriented acupuncture stimulation methods can be divided into manual needle, laser needle (blue, red and infrared laser light) and electrical punctual stimulation at the body, hand and ear. Special emphasis in this research article is given to totally new technical and methodological investigations, e.g. the first data published worldwide in medicine obtained with new blue laser acupuncture equipment. In this regard, critical summary and recent results from peripheral and central measurements during acupuncture stimulation using high-tech bioengineering assessment are given. In addition, we describe the first teleacupuncture performed between Asia and Europe.

Blue-light irradiation regulates proliferation and differentiation in human skin cells

Sunlight influences the physiology of the human skin in beneficial as well as harmful ways, as has been shown for UV light. However, little is known about the effects of other wavelengths of solar irradiation. In this study we irradiated human keratinocytes and skin-derived endothelial cells with light-emitting-diode devices of distinct wavelengths to study the effects on cell physiology. We found that light at wavelengths of 632-940 nm has no effect, but irradiation with blue light at 412-426 nm exerts toxic effects at high fluences. Light at 453 nm is nontoxic up to a fluence of 500 J/cm(2). At nontoxic fluences, blue light reduces proliferation dose dependently by up to 50%, which is attributable to differentiation induction as shown by an increase of differentiation markers. Experiments with BSA demonstrate that blue-light irradiation up to 453 nm photolytically generates nitric oxide (NO) from nitrosated proteins, which is known to initiate differentiation in skin cells. Our data provide evidence for a molecular mechanism by which blue light may be effective in treating hyperproliferative skin conditions by reducing proliferation due to the induction of differentiation. We observed a photolytic release of NO from nitrosated proteins, indicating that they are light acceptors and signal transducers up to a wavelength of 453 nm.

Multimodality imaging of nitric oxide and nitric oxide synthases

Nitric oxide (NO) and NO synthases (NOSs) are crucial factors in many pathophysiological processes such as inflammation, vascular/neurological function, and many types of cancer. Noninvasive imaging of NO or NOS can provide new insights in understanding these diseases and facilitate the development of novel therapeutic strategies. In this review, we will summarize the current state-of-the-art multimodality imaging in detecting NO and NOSs, including optical (fluorescence, chemiluminescence, and bioluminescence), electron paramagnetic resonance (EPR), magnetic resonance (MR), and positron emission tomography (PET). With continued effort over the last several years, these noninvasive imaging techniques can now reveal the biodistribution of NO or NOS in living subjects with high fidelity which will greatly facilitate scientists/clinicians in the development of new drugs and/or patient management. Lastly, we will also discuss future directions/applications of NO/NOS imaging. Successful development of novel NO/NOS imaging agents with optimal in vivo stability and desirable pharmacokinetics for clinical translation will enable the maximum benefit in patient management.

Biological activity of hemoprotein nitrosyl complexes

Chemical and biological functions of hemoprotein nitrosyl complexes as well as their photolysis products are discussed in this review. Chemical properties of nitric oxide are discussed, and major chemical reactions such as interaction with thiols, free radicals, and transition metals are considered. Specific attention is paid to the generation of hemoprotein nitrosyl complexes. The mechanisms of nitric oxide reactions with hemoglobin and cytochrome c and physicochemical properties of their nitrosyl complexes are discussed. A review of photochemical reactions of nitrosyl complexes with various ligands is given. Finally, we observe physiological effects of visible radiation on hemoprotein nitrosyl complexes: smooth muscle relaxation and reactivation of mitochondrial respiration.