Effect of low power laser irradiation on disconnecting the membrane-attached hemoglobin from erythrocyte membrane

Healing of self-inflicted thermal injury of palatal mucosa by low-level laser therapy

Self-inflicted injury to oral mucosa is a rare entity. These injuries can be premeditated, accidental, or can result from an abnormal habit. These uncommon gingival injuries can sometimes test the clinician's diagnostic abilities as well as treatment planning skills. In conventional treatment, removal of etiology and application of topical drugs is usually sufficient for healing. However, some cases require alternative or adjunctive wound healing methods. Low-level laser therapy (LLLT) has been reported to be effective in pain management and improvement in wound healing through promotion, fortification, and commissioning of cellular cycle to generate productive and substitute cells. This report presents a case of 25-year-old female with complaints of a painful, nonhealing wound on the palate for last 6 months. She had an unusual habit of keeping burning matchsticks in her mouth. Although she had quit the habit 2 months ago after psychiatric counseling, the wound on her palate did not show any improvement in symptoms. Based on the history and clinical findings, diagnosis of chronic wound by self-inflicted thermal injury was made. LLLT was administered on the wound every 48 hours for next 10 days. The burn wound healed completely after five applications of LLLT.

Laser-induced changes of in vitro erythrocyte sedimentation rate

The study of the effects of low-level laser (LLL) radiation on blood is important for elucidating the mechanisms behind the interaction of LLL radiation and biologic tissues. Different therapy methods that involve blood irradiation have been developed and used for clinical purposes with beneficial effects. The aim of this study was to compare the effects of different irradiation protocols using a diode-pumped solid-state LLL (λ = 405 nm) on samples of human blood by measuring the erythrocyte sedimentation rate (ESR). Human blood samples were obtained through venipuncture into tubes containing EDTA as an anticoagulant. Every sample was divided into two equal aliquots to be used as an irradiated sample and a non-irradiated control sample. The irradiated aliquot was subjected to a laser beam with a wavelength of 405 nm and an energy density of 72 J/cm². The radiation source had a fixed irradiance of 30 mW/cm². The ESR change was observed for three different experimental protocols: irradiated whole blood, irradiated red blood cells (RBCs) samples re-suspended in non-irradiated blood plasma, and non-irradiated RBCs re-suspended in irradiated blood plasma. The ESR values were measured after laser irradiation and compared with the non-irradiated control samples. Irradiated blood plasma in which non-radiated RBCs were re-suspended was found to result in the largest ESR decrease for healthy human RBCs, 51%, when compared with RBCs re-suspended in non-irradiated blood plasma. The decrease in ESR induced by LLL irradiation of the plasma alone was likely related to changes in the plasma composition and an increase in the erythrocyte zeta potential upon re-suspension of the RBCs in the irradiated blood plasma.

Effect of visible laser light on ATP level of anaemic red blood cell

In this work we present influence of visible laser light on ATP level and viability of anaemic red blood cell (RBC). The visible laser lights used in this work are 460nm and 532nm. The responses of ATP level in anaemic and normal RBC before and after laser irradiation at different exposure time (30, 40, 50 and 60s) were observed. Three aliquots were prepared from the ethylenediaminetetraacetic acid (EDTA) blood sample. One served as a control (untreated) and another two were irradiated with 460nm and 560nm lasers. Packed RBC was prepared to study ATP level in the RBC using CellTiter-GloLuminescent cell Viability Assay kit. The assay generates a glow type signal produced by luciferase reaction, which is proportional to the amount of ATP present in RBCs. Paired t-test were done to analyse ATP level before and after laser irradiation. The results revealed laser irradiation improve level of ATP in anaemic RBC. Effect of laser light on anaemic RBCs were significant over different exposure time for both 460nm (p=0.000) and 532nm (p=0.003). The result of ATP level is further used as marker for RBC viability. The influence of ATP level and viability were studied. Optical densities obtained from the data were used to determine cell viability of the samples. Results showed that laser irradiation increased viability of anaemic RBC compared to normal RBC.

Effects of a low-level semiconductor gallium arsenide laser on local pathological alterations induced by Bothrops moojeni snake venom

Antivenom therapy has been ineffective in neutralizing the tissue damage caused by snakebites. Among therapeutic strategies to minimize effects after envenoming, it was hypothesized that a low level laser would reduce complications and reduce the severity of local snake venom effects. In the current study, the effect of a low-level semiconductor gallium arsenide (GaAs) laser on the local pathological alterations induced by B. moojeni snake venom was investigated. The experimental groups consisted of five male mice, each administered either B. moojeni venom (VB), B. moojeni venom + antivenom (VAV), B. moojeni venom + laser (VL), B. moojeni venom + antivenom + laser (VAVL), or sterile saline solution (SSS) alone. Paw oedema was induced by intradermal administration of 0.05 mg kg(-1) of B. moojeni venom and was expressed in mm of directly induced oedema. Mice received by subcutaneous route 0.20 mg kg(-1) of venom for evaluating nociceptive activity and the time (in seconds) spent in licking and biting the injected paw was taken as an indicator of pain response. Inflammatory infiltration was determined by counting the number of leukocytes present in the gastrocnemius muscle after venom injection (0.10 mg kg(-1)). For histological examination of myonecrosis, venom (0.10 mg kg(-1)) was administered intramuscularly. The site of venom injection was irradiated by the GaAs laser and some animals received antivenom intraperitoneally. The results indicated that GaAs laser irradiation can help in reducing some local effects produced by the B. moojeni venom in mice, stimulating phagocytosis, proliferation of myoblasts and the regeneration of muscle fibers.

Visualization study of motion and deformation of red blood cells in a microchannel with straight, divergent and convergent sections

The size of red blood cells (RBC) is on the same order as the diameter of microvascular vessels. Therefore, blood should be regarded as a two-phase flow system of RBCs suspended in plasma rather than a continuous medium of microcirculation. It is of great physiological and pathological significance to investigate the effects of deformation and aggregation of RBCs on microcirculation. In this study, a visualization experiment was conducted to study the microcirculatory behavior of RBCs in suspension. Motion and deformation of RBCs in a microfluidic chip with straight, divergent, and convergent microchannel sections have been captured by microscope and high-speed camera. Meanwhile, deformation and movement of RBCs were investigated under different viscosity, hematocrit, and flow rate in this system. For low velocity and viscosity, RBCs behaved in their normal biconcave disc shape and their motion was found as a flipping motion: they not only deformed their shapes along the flow direction, but also rolled and rotated themselves. RBCs were also found to aggregate, forming rouleaux at very low flow rate and viscosity. However, for high velocity and viscosity, RBCs deformed obviously under the shear stress. They elongated along the flow direction and performed a tank-treading motion.

Low-level laser irradiation inhibits abdominal aortic aneurysm progression in apolipoprotein E-deficient mice

AIMS

Increased early detection of abdominal aortic aneurysm (AAA) and the severe complications of its current treatment have emphasized the need for alternative therapeutic strategies that target pathogenetic mechanisms of progression and rupture. Recent in vitro studies from our laboratory have shown that low-level laser irradiation (LLLI) (780 nm) modifies cellular processes fundamental to aneurysm progression. The present study was designed to determine whether LLLI retards the progression of suprarenal AAA in vivo.

METHODS AND RESULTS

High-frequency ultrasonography (0.01 mm resolution) was used to quantify the effect of LLLI on aneurysmatic aortic dilatation from baseline to 4 weeks after subcutaneous infusion of angiotensin II by osmotic minipumps in the apolipoprotein E-deficient mouse. At 4 weeks, seven of 15 non-irradiated, but none of the 13 LLLI, mice had aneurysmal dilatation in the suprarenal aneurysm-prone segments that had progressed to >or=50% increase in maximal cross-sectional diameter (CSD) over baseline (P = 0.005 by Fisher's exact test). The mean CSD of the suprarenal segments (normalized individually to inter-renal control segments) was also significantly lower in irradiated animals (LLLI vs. non-irradiated: 1.32 +/- 0.14 vs. 1.82 +/- 0.39, P = 0.0002 by unpaired, two-tailed t-test) with a 94% reduction in CSD at 4 weeks compared with baseline. M-mode ultrasound data showed that reduced radial wall velocity seen in non-treated was significantly attenuated in the LLLI mice, suggesting a substantial effect on arterial wall elasticity.

CONCLUSION

These in vivo studies, together with previous in vitro studies from this laboratory, appear to provide strong evidence in support of a role for LLLI in the attenuation of aneurysm progression. Further studies in large animals would appear to be the next step towards testing the applicability of this technology to the human interventional setting.

Light distribution in the erythrocyte under laser irradiation: a finite-difference time-domain calculation

In medical applications of low power laser irradiations, safety is one of the most concerning problems since the light focused by the biological object itself may cause damage of living organisms. The light distributions in an erythrocyte with the shape of native biconcave, oblate spheroid, or disk sphere under the irradiation of a plane light of 632.8 nm were studied with a numerical calculation method of finite-difference time domain. The focusing effect by either the biconcave erythrocyte, oblate spheroid, or disk sphere erythrocyte was found to be so remarkable that the light intensities at the focused areas close to the erythrocyte membrane were about 10 times higher than that of the incident light when the light irradiated along the erythrocyte plane. This focusing effect became weak and even disappeared when the irradiation direction deviated from the erythrocyte plane for more than an angle of 15 degrees. Because the highest light intensity in the erythrocyte can be about one order of magnitude higher than that of the incident light, this factor should be taken into account for laser safety in medical applications.

Measuring the simultaneous effects of hypoxia and deformation on ATP release from erythrocytes

It is known that adenosine triphosphate (ATP) is released from red blood cells (RBCs) due to various forms of stimulation such as deformation, pharmacological stimuli, and hypoxia. To date, these various stimuli have been investigated individually. Here, we have combined a microflow system capable of initiating deformation-induced release of ATP from the RBCs at various levels of hypoxia as measured by percent oxygen saturation in the RBC sample. When values of ATP released from deformation and hypoxia are compared to values of ATP release due to hypoxia alone, the relationship between the two stimuli can be deduced. Measurement of RBC-derived ATP with the well-known chemiluminescence assay employing luciferin/luciferase indicates that RBCs deoxygenated for 4 min released 1.84 +/- 0.075 microM ATP. The largest decrease in oxygen saturation was found to be between 0 s (66.3% O(2) saturation) and 15 s (22.3% O(2) saturation). RBCs deoxygenated to a 22.3% O(2) saturation released 0.374 +/- 0.011 microM ATP when pumped through the microflow system. This value is an increase from 0.281 +/- 0.007 microM ATP in the presence of flow alone. The ATP release after exposure to hypoxia at 22.3% O(2) saturation was 0.381 +/- 0.014 microM ATP, a value statistically equivalent to that of hypoxia and flow combined. These data suggest that, at an oxygen saturation point of around 25.0% or above, deformation contributes to ATP release from the RBC; however, beyond this saturation point, the ATP release is largely due to hypoxia.