[Laser therapy effect on endothelial dysfunction in patients after the surgery for orthognathic disorders]. / Vliyanie lazernoi terapii na endotelial'nuyu disfunktsiyu u bol'nykh, operirovannykh po povodu ortognaticheskoi patologii.

OBJECTIVE: To optimize postoperative rehabilitation by applying low-intensity laser irradiation (LILI) with different wavelengths in the early postoperative period to prevent inflammatory complications. MATERIAL AND METHODS: After radiological examination and ultrasound diagnostics of the periodontal tissue vessels, surgical methods of orthognathic treatment were performed, after completion of which a course of LILI was carried out. The VEGF its receptors (sVEGF-R1; sVEGF-R2) content was measured by enzyme immunoassay using standard reagent kits. The laser therapy using 635 nm laser light was applied directly to the vestibular and oral surfaces of the gingival tissues and in the operation area, changeable by the scanning method, for 1.5 minutes (5 W power); the pulsed infrared laser therapy (PILT) with the 904 nm wavelength (light pulse duration 100 s, power 15 W, 1500 Hz) applied epicutaneously to the operation projective zones (four control points of the upper and lower jaw) through the skin of the cheek, in stable method (1.5 minutes) with a time range between red and infrared wavelength LILI not exceeding 100 s (1.5 minutes). RESULTS: Vascular and endothelial dysfunction after laser irradiation with different wavelengths is better controlled by increasing the microcapillary blood flow (66.7% gain; p<0.05) in arteriolar and 70.3% in venular sections of capillaries (p<0.01), which is associated by vasodilatation: diameter increased by 26.9% compared to that under the influence of red laser radiation (by 13.0%) and infrared laser radiation (by 7.2%); p<0.01). CONCLUSIONS: Early laser therapy using the low-intensity laser irradiation with different wavelengths improves vasoactive processes of hemoregulation in dental tissues associated with the elimination of vasospasm caused by operative stress, activation of arteriolodilatory effects, contributes to the prevention of development of inflammatory complications.

Photobiomodulation Therapy to Promote Angiogenesis in Diabetic Mice with Hindlimb Ischemia.

Objective: To assess whether photobiomodulation therapy (PBMT) induces angiogenesis in diabetic mice with hindlimb ischemia (HLI). Background: Patients with diabetes mellitus (DM) are at high risk of developing peripheral arterial disease (PAD) in the lower extremities. PBMT has been shown to promote angiogenesis both in vitro and in vivo and could be a treatment for DM patients with PAD. Methods: Femoral artery ligation/excision in mice was performed to induce HLI as an animal model of PAD. PBMT at a dose of 660 nm and 1.91 J/cm2 was delivered for 10 min on 5 consecutive days after the HLI surgery. Control mice received HLI only. Mice in the DM group were injected with streptozocin to induce diabetes before HLI surgery. Mice in the laser and DM+ laser groups received both HLI and PBMT, and the latter group had induced DM. After the laser treatment, lower limb blood flow was evaluated by laser Doppler. The capillary density and CD31 were analyzed by immunofluorescence staining, and protein levels of vascular endothelial growth factor (VEGF)-A, hypoxia-inducible factor-1α (HIF-1α), inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), and extracellular signal-regulated kinases (ERK) were measured by Western blotting of tissue samples. Results: Compared with the control and DM mice, the laser and DM+ laser groups had more than double the capillary density and blood perfusion rate. Levels of CD31 and VEGF-A proteins in groups that received laser were increased by 1.9- to 3.2-fold compared with groups that did not undergo laser treatment. Animals treated with PBMT exhibited significantly increased HIF-1α expression and ERK phosphorylation compared with animals that did not receive this treatment, and the amount of phospho-eNOS and iNOS increased and decreased, respectively. Conclusions: PBMT can induce therapeutic angiogenesis, indicating that low intensity laser could be a novel treatment for PAD patients.

Effect of Infrared Low-Intensity Laser Irradiation on Lipid Peroxidation under Conditions of Experimental Circulatory Hypoxia of Visual Analyzer.

The physiological stress modeled by circulatory hypoxia activates LPO processes in various tissues. In posthypoxic period, the infrared low-intensity laser irradiation significantly decreased the chemiluminescence parameters in blood plasma, normalized the retinal levels of diene and triene conjugates, and decreased MDA in the rat brain attesting to the correcting effect of this irradiation during various types of physiological stresses.

Effect of 405 nm low intensity irradiation on the absorption spectrum of in-vitro hyperlipidemia blood.

BACKGROUND: Laser therapy is reported to be clinically effective for improving microcirculation, rheological properties and blood lipid profiles despite the lack of certainty on the mechanism. OBJECTIVE: This study intends to provide methods to drop blood lipid level of hyperlipidemia samples by low-intensity laser irradiation therapy and provide reasoning of mechanism. METHODS: Twenty whole blood samples of high level of lipids profile are irradiated by 405 nm low-intensity laser at 12 J/cm2 twice a day for 3 days and compared with normal lipids profile group. Then whole blood sample are centrifuged to obtain result of erythrocyte for further interpretation. Multi-scan spectrum microplate reader is used to measure absorption spectrum and data is analyzed by software SPSS 14.0. RESULTS: Results show that after 405 nm low-intensity laser irradiation, whole blood samples of high lipid level statistically have higher absorbance peak value than normal samples while erythrocyte samples have lower absorbance peak value. CONCLUSIONS: From the divergence of absorption peak value change after low-intensity laser irradiation for whole blood sample and erythrocyte, we suspect that low level laser irradiation affects the enzymes activity of lipid metabolism, improves the cholesterol balance of plasma and cytoplasm in erythrocyte, and decreases aggregation of the erythrocyte.

Beneficial Role of Low-Intensity Laser Irradiation on Neural ß-tubulin III Protein Expression in Human Bone Marrow Multipotent Mesenchymal Stromal Cells.

The purpose of the present study was to evaluate the neural protein expression pattern of human multipotent mesenchymal stromal cells (hMSCs) treated with forskolin (free-form/FF). The study investigated forskolin's capacity to enhance intracellular levels of cyclic adenosine monophosphate (cAMP) by activating adenylate cyclase and probably by inducing neuron-like cells in vitro. In addition, because nanotechnology is a growing field of tissue engineering, we also assessed the action of a new system called the nanostructured-forskolin (NF) to examine the improvement of drug delivery. Afterwards, the cells were submitted to low-level laser irradiation to evaluate possible photobiostimulatory effects. Investigations using the immunofluorescence by confocal microscopy and Western blot methods revealed the expression of the neuronal marker ß-tubulin III. Fluorescence intensity quantification analysis using INCell Analyzer System for ß-tubulin III was used to examine significant differences. The results showed that after low-level laser irradiation exposure, there was a tendency to increase the ß-tubulin III expression in all groups, as expected in the photobiostimulation process. Notably, this process induced for irradiation was more pronounced in irradiated nanoforskolin cells (INF) compared to non-irradiated free-forskolin control cells (NFFC). However, there was also an increase in ß-tubulin III protein expression in the groups: irradiated nanocontrol cells (INC) compared to non-irradiated free-forskolin control cells (NFF) and after treatment with non-irradiated free-forskolin (NFF) and non-irradiated nanoforskolin (NNFC). We concluded that the methods using low-level laser irradiation and/or nanoparticles showed an up-regulation of neural-protein expression in hMSCs that could be used to facilitate cellular therapy protocols in the near future.

Effect of Laser Irradiation on Cell Cycle and Mitosis.

Introduction: In this research, low-level helium-neon (He-Ne) laser irradiation effects on monkey kidney cells (Vero cell line) mitosis were studied. Methods: The experiment was carried out on a monkey kidney cell line "Vero (CCL-81)". This is a lineage of cells used in cell cultures and can be used for efficacy and media testing. The monolayer cells were formed on coating glass in a spectral cuvette (20×20×30 mm). The samples divided into two groups. The first groups as irradiated monolayer cells were exposed by a He-Ne laser (PolyaronNPO, L'vov, Ukraine) with λ=632.8 nm, max power density (P) = 10 mW/cm2 , generating linearly polarized and the second groups as the control monolayer cells were located in a cuvette protected by a lightproof screen from the first cuvette and also from the laser exposure. Then, changing functional activity of the monolayer cells, due to the radiation influence on some physical factors were measured. Results: The results showed that low-intensity laser irradiation in the range of visible red could make meaningful changes in the cell division process (the mitosis activity). These changes depend on the power density, exposure time, the presence of a magnetic field, and the duration of time after exposure termination. The stimulatory effects on the cell division within the power density of 1-6 mW/(cm2 ) and exposure time in the range of 1-10 minutes was studied. It is demonstrated that the increase in these parameters (power density and exposure time) leads to destructing the cell division process. Conclusion: The results are useful to identify the molecular mechanisms caused by low-intensity laser effects on the biological activities of the cells. Thus, this study helps to optimize medical laser technology as well as achieving information on the therapeutic effects of low-intensity lasers.

[Cytotoxic Effect of Low-Intensity Infrared Laser Irradiation on Human Melanoma Cells].

Continuous low-intensity laser irradiation (LILI) affects the state of cells in culture, including their proliferation rate. Data collected with various cell models vary significantly, but most studies have reported positive effects of LILI on cell proliferation. The effects of continuous infrared LILI (835 nm) was studied using three independent different melanoma cell lines. The LILI effect was shown to strongly depend on the irradiation dose. Higher doses (230 kJ/m^(2)) significantly suppressed the cell growth. A further increase in LILI dose led to a significant cytotoxic effect, which increased disproportionately quickly with the increasing light intensity. Human mesenchymal stem cells (MSCs) were found to be significantly more resistant to the cytotoxic effect of higher-dose LILI. Importantly, the effects were not due to the difference in culture conditions. Control experiments showed that 15 non-melanoma tumor cell lines were more resistant to LILI than melanoma cells. Selective sensitivity of melanoma cells to LILI in vitro was assumed to provide a basis for LILI-based approaches to melanoma treatment.

Photobiomodulation of breast and cervical cancer stem cells using low-intensity laser irradiation.

Breast and cervical cancers are dangerous threats with regard to the health of women. The two malignancies have reached the highest record in terms of cancer-related deaths among women worldwide. Despite the use of novel strategies with the aim to treat and cure advanced stages of cancer, post-therapeutic relapse believed to be caused by cancer stem cells is one of the challenges encountered during tumor therapy. Therefore, further attention should be paid to cancer stem cells when developing novel anti-tumor therapeutic approaches. Low-intensity laser irradiation is a form of phototherapy making use of visible light in the wavelength range of 630-905 nm. Low-intensity laser irradiation has shown remarkable results in a wide range of medical applications due to its biphasic dose and wavelength effect at a cellular level. Overall, this article focuses on the cellular responses of healthy and cancer cells after treatment with low-intensity laser irradiation alone or in combination with a photosensitizer as photodynamic therapy and the influence that various wavelengths and fluencies could have on the therapeutic outcome. Attention will be paid to the biomodulative effect of low-intensity laser irradiation on cancer stem cells.

Radiodensitometric Assessment of the Effect of Pulsed Electromagnetic Field Stimulation Versus Low Intensity Laser Irradiation on Mandibular Fracture Repair: A Preliminary Clinical Trial.

PURPOSE: Closed reduction of mandibular fractures usually entails a relatively long period of immobilization, with the subsequent delay of rehabilitation. Therefore, shorter immobilization period with various approaches to protect or enhance bone healing have been investigated. The aim of this study was to analyze the effects of pulsed electromagnetic field (PEMF) and low intensity laser irradiation (LILI) on the fracture healing process, through radiodensitometric assessment of the bone callus. PATIENTS AND METHODS: Eighteen patients with mandibular fractures at the tooth bearing area participated in this prospective study. They were treated by closed reduction using maxillo-mandibular fixation (MMF) and were consecutively assigned into 1 of 3 groups. In group A, the fracture sites were exposed to PEMF for 2 h daily for 12 days. In group B, the fracture sites were exposed to LILI on the tenth and twelfth postoperative days (2 sessions of 6 min per day 2 h apart). The fracture sites in group C acted as controls. MMF was maintained for 2 weeks in group A and 4 weeks in groups B and C. The bone fracture healing was evaluated clinically by investigating the union of the fractured segments and radiographically using computerized densitometry. The union of the fractured segments was tested by manual manipulation and the occlusion was assessed upon removal of MMF. Standardized digital panoramic radiographs were performed for each patient, immediately postoperatively as well as at 2 and 4 weeks. The digital images were manipulated using the IDRISI software. A rectangular area of 10 × 15 mm was drawn along the center of the fracture line. The obtained densitometry values were expressed in gray levels from 0 to 256. The collected data were then tabulated and statistically analyzed. RESULTS: After releasing the MMF, the bimanual mobility test of the fractured segments in all patients showed stability of the segments. The preinjury occlusion was maintained in all patients. The postoperative radiographs of all patients revealed good bony alignment of the bony segments. In all groups, comparison between the study intervals with respect to both means and changes percentages of the bone density values showed insignificant differences. At 2nd postoperative week, the mean bone density at the fracture sites decreased by 4.74, 6.6 and 27.89 % in groups A, B and C respectively. The period from the 2nd to the 4th postoperative weeks showed increase in the bone density by 1.49, 1.95 and 14.12 % in groups A, B and C respectively. Insignificant difference was found between the means of bone densities of group A and B throughout the study intervals. On the other hand, both groups showed insignificant difference with group C immediately postoperative and significant increase in bone density at the 2nd and 4th postoperative weeks. CONCLUSIONS: Short period immobilization of mandibular fractures for 2 weeks supplemented with PEMF is recommended. Further studies are needed to evaluate the efficacy of LILI as a supplement to reduce the mandibular fracture immobilization period.

Healing cutaneous wounds through laser irradiation / 中华物理医学与康复杂志

Objective To quantify the effect of 650 nm semiconductor laser irradiation on cutaneous wound healing in rabbits. Methods Model wounds were induced in 21 adult male rabbits. They were then divided randomly into a control group, a 5 mW irradiation group and a 10 mW irradiation group. Biometry and light microscopy were used to investigate the effect of low intensity laser therapy (LILT) on cutaneous wound healing. Results Statistically significant differences were observed among the groups in terms of wound shrinkage. The differences between the irradiated and control groups were significant at the 5th, 9th and 13th day. However, any differences between the S mW and 10 mW groups were not significant. Conclusions LILT at 650 nm at either 5 mW or 10 mW and 1 J/cm2 accelerates cutaneous wound healing in rabbits. But irradiation at 10 mW is no more effective than at 5 mW.

Effect of Tangnaoluotong Combined with Intravenous Low Intensity Laser Irradiation on Blood Rheology and Endothelin of Diabetes Mellitus and Cerebral Infarction Patients / 中国中医药信息杂志

Objective To observe the effect on the patients of diabetes mellitus and cerebral infarction in terms of level of blood rheology and endothelin after using both intravenous low intensity laser irradiation (ILILI) and traditional Chinese medicine Tangnaoluotong in the treatment. Method Ninety patients of diabetes mellitus and cerebral infarction, having the symptom of deficiency in both vital energy and yin with blood stasis, were divided into three treatment groups at random:ILILI group (A), TCM treatment group (B), and a group with compound treatment of ILILI and TCM (C). The level of blood rheology and endothelin were observed after 1 month’s treatment. Result Compared with group A and group B, group C could significantly reduce the level of fibrinogen and endothelin, improve the deformed ability of RBC. Conclusion ILILI with Tangnaoluotong can significantly alter the blood rheology and endothelin on the patients of diabetes mellitus and cerebral infarction, which result in a better curative effect.