The aim of these experiments was a direct measurement of changes in absorption of cellular monolayers under diode laser irradiation. First, a sensitive method for multichannel registration of absorption of a cell monolayer in range 500-8060 nm was developed. Second, absorption spectra of intact HeLa cells and those after irradiation the monolayer with light at 670 and 820 nm were recorded. Third, the comparison of the absorption spectra and action spectra was performed.

The biostimulative effects exerted by various low power lasers in the visible and near IR might be a consequence of reactive oxygen species (ROS) production. Although high concentration of ROS leads to cell death, low and controlled concentrations may play an important role in cell activation. It is assumed that the light which is absorbed by endogenous photosensitizers induces the formation of minute amounts of ROS which are beneficial for the cell. In the present review we summarize recent experimental data providing evidence for ROS involvement in photobiostimulation of skin and sperm cells.

Low energy laser irradiation has an effect on Nerve Growth Factor and anti mitotic factors release from rat and mouse skeletal muscle cultures. It was found that there is a transient elevation of intracellular calcium in the myotubes immediately after irradiation. Calcium changes were detected by dynamic video imaging systems and with a photometric system. Pre incubation of the myotubes with photosensitizers enhance the elevation of both cytosolic calcium and cytokines release from the cells after Helium/Neon irradiation with energy of 3-10 J/cm². These findings can lead to an hypothesis that transient changes in calcium can accelerate cytokines release from the myotubes.

The low power He-Ne laser radiation has been extensively used in past decades as medical device to relieve pain, accelerate wound healing as well as aiming beam in invisible laser beam in invisible laser beam applications. It is not known however if there are any secondary, undesirable effects of He-Ne laser radiation on the irradiated tissue. In this paper we investigate the changes induced in membrane fluidity of human erythrocyte during/upon the interaction with the He-Ne laser beam having the parameters currently used for target aiming in laser surgery.

The electrophysiological characteristics rat spinal cord neurons, rat hippocampus pyramidal neurons, guinea pig cardiomyocytes, rat brain glial cells, and bovine pulmonary artery endothelial cells were measured by the common patch- clamp technique. No light effects on the voltage-activated whole-cell ionic currents were found in any type of the cells. The only ionic current type influenced by the radiation in all the cells under study was the background single-channel currents recorded inn the cell-attached configuration. The opening frequency of the background single channels was suppressed by the light and the open state probability was decreased under the irradiation. The same channels in the inside-out patches were found to be light insensitive.

In view of the versatility and usage of the CO₂ laser as a too. in surgery and dermatology, we have studied its effect on enhancing proliferation of cultured skin cells using an attenuated CO₂ laser. Exposure of cultured keratinocytes or fibroblasts to continuous wave or pulse mode irradiation enhanced thymidine incorporation by 1.4 to 1.7 folds, and cell number by 1.25 to 1.4 folds, measured 24 and 48 hours later, depending on the fluency applied. As expected, these effects were not suppressed by added antioxidants, indicating that the mechanism involved in this newly observed effect, differ from photosensitization by low energy visible and near IR lasers.

Attempts to date to increase the rate of embryo implantation, for example by assisting embryo hatching from the zona pellucida, have failed. Recently, several studies have suggested the biostimulating effect of low power laser irradiation. The objective of this study was therefore to examine the potential of low power laser irradiation of the uterus to enhance embryo implantation rate in the rat. Rat potential of low power laser irradiation of the uterus to enhance embryo implantation rate in the rat. Rat blastocysts were flushed from the uterus on day 5 of gestation. They were transferred to the uteri of pseudopregnant recipients on day 4 or 5 of pseudopregnancy. One cornu of the recipient uterus was irradiated; the other was used as control. On day 5 of pregnancy, irradiation did not change implantation rate after 10 or 30 sec of irradiation while 120 sec. of irradiation significantly decreased embryonic implantation. On the other hand, on day 4 of pregnancy, 120 sec. of radiation allowed embryonic implantation to a level similar to that seen after synchronized transfer. Conclusion: He-Ne laser irradiation of the exposed rat uterus can attenuate embryo implantation rate.

This study was undertaken to investigate the influence of low level s- and p-polarized visible He-Ne laser irradiation on healing of skin wounds. Three lesions about 6 mm in diameter were induced on back of rates with liquid nitrogen: one was irradiated by He-Ne s-polarized radiation, other by He-Ne p-polarized and the third lesion was not irradiated. Two rats were killed after each irradiation to get sections of tissue for morphological analysis. The wound illuminated by p-polarized He-Ne was completely healed after 17 days when compared to other lesions which showed a poor degree of healing.

Nowadays low-power therapy is one of the leading trends in a combined treatment of the oral cavity and lips diseases. The present paper sums up the results of the investigation into the biological effects caused by low-power laser light (LPLL) during its interaction with hard and soft tissues of the oral cavity and lips. A research on the effect of LPLL upon the remineralization processes in the hard dental tissues in the stage in the stage of an initial caries was carried out in 150 patients. The biological effects caused by an interaction of LPLL with the parodontium tissues in the process of treatment of medium degree disease of the parodontium were studied in 140 patients; the effects of the above mentioned character which generated in lips tissues during treatment of a post-radiation chilitis were analyzed in 32 patients. Immunological, biochemical histochemical, morphological, stomatoscopic, bacteriological and other methods were employed while studying the bioeffects caused by LPLL in the parodontium, lips tissues and hard tissues of the tooth.

The influence of incoherent low-power luminescent red light (Lumir) on recovery of cardiac contractile function during post-ischemic period was investigate. The method of isolated heart was used. Considerable reduce of heart rate was observe.d It is proved, that Lumir contributes to accelerated recovery of contractile function of myocardium. The physiotherapeutic procedure led also to improvement of heart rate and to stabilization of relaxation speed in post- ischemic period.

Influence of low-power luminescent red radiation (Lumir) on lipid peroxidation level in myocard tissues during post- ischemic period was studied. The model of isolated heart was used. The possibility to reduce the lipid peroxidation level in myocard tissues during the period of reperfusion by phototherapeutic procedures was discovered.

In this paper the authors present their own experience in lasertherapy of motional system overloading syndromes in 522 patients, in which laser radiation was used as monotherapy. IR semiconductor lasers and He-Ne laser were used. Each irradiation procedure was performed in 2 stages: 1) the scan of painful region; 2) irradiation of trigger points. As a result of 10-25 irradiations the improvement was obtained in 61-87 percent of patients and it was significantly better as compared to the control group in which sham-irradiation was made. On the basis of obtained results one may conclude that lasertherapy is a very useful, assisting method in treatment of motional system overloading syndromes. The therapeutical effects of the method are related to analgesic and antiphlogistic action of laser radiation.

The aim of the study was to confirm the analgesic effect of low-power laser radiation with a tail-immersion test and check if nitric oxide is involved in laser radiation-induced analgesia in rats. The experiment was performed on male Wistar rats. On the day of experiment the scull of rats was exposed to IR laser radiation for 10 min and antinociceptive effect was determined by means of tail immersion test. The experiments were also performed on 1-NAME and methylene blue pretreated rates, in which both chemicals were administered into right lateral brain ventricle. The results were compared to the ones obtained in the control group in which sham irradiation was made. It was observed that 10 min. exposure to low-power IR laser radiation induced only transient distinct antinociceptive effect in rats. This effect was prevented by ICV. injection of 1-NAME, an inhibitor of nitric oxide synthase and methylene blue, an inhibitor of soluble guanylate cyclase. It seems that nitric oxide is involved in mechanism of low-power laser radiation- induced analgesia.

The action spectra on hemoglobin and oxyhemoglobin of cutaneous blood vessels in dependence of the depth of penetration of laser radiation on tissue is investigated. The obtained results allows to choose the proper wave-length of laser radiation for a selective and efficient action on blood chromophors. There is a narrow action spectrum in a visible spectral range in activation of photochemical processes or biostimulation mechanisms through the impact on the oxyhemoglobin on deep layer of cutaneous blood vessels. The primary mechanism of biostimulation and therapeutic effect of low energy laser radiation based on local increasing of efficiency of oxygen transportation by oxyhemoglobin of cutaneous blood vessels is discussed.

The subject of this work follows changes of the sIgA and albumin levels in the saliva of the patients treated after the extraction of their lower molars with either diode or He-Ne biostimulatory laser, using different modulatory frequencies. The results were compared with the sIgA and albumin levels in the saliva of the control, i.e. not- treated group. Appropriately chosen laser beam modulatory frequency should influence the increase in the sIgA and albumin levels against the base level. In our study, this hypothesis was confirmed in the group treated with the frequency of 9000Hz. The changes of the levels of the watched markers versus the control group were however statistically insignificant. The aim of this study was to contribute to the evaluation of specific modulatory frequencies for therapeutical use in a given pathological cause of the oral cavity.

The methods and technical facilities of testing the biomedical effects caused by the influence of low-power laser radiation in the process of laser therapy are presented. Described studies have been conducted by means of the complex of fireware facilities consisting of the system of electroacupuncture diagnostics (EA) and a system of laser therapy on the basis of multichannel laser and magneto-laser devices. The task of laser therapy was concluded in undertaking acupuncture anaesthetization, achievement of antioedemic and dispersional actions, raising tone of musculus and nervous system, normalization of immunity factors under the control of system EA. The 82 percent to 95 percent agreement of the result of an electroacupuncture diagnostics with clinical diagnoses were achieved.

The interaction between the low power light and the tissues is not clear. We chose the blood and the erythrocytes because, the first one is the plenty and most necessary for life and the erythrocyte is the simplest cell. Light from different sources, HeNe laser, 675 nm laser, 785 nm laser, 904 nm GaAs laser and 940 nm light emitting diode were used for irradiation of blood. We found a threshold time form which these lights induce changes in the normal blood cell. Results may be explained by considering the differences between the moment of inertia of the lipid configuration on the membrane of the cell.

The authors tried to verify the efficacy of low energy laser (LEL) in scalp alopecia. Sixty patients were divided in two groups: A) laser group, 33 patients treated with both LEL and classical therapy; B) control group, 27 patients treated only with classical therapy, Before, during and after treatment, historical samples were done. For the group A the results were rather superior but in a twice shorter time shorter time than group B. The maintenance of the good results needed classical therapy for a long period. We conclude that LEL therapy could have a useful complementary method for the treatment of scalp alopecia.