Helium-neon Laser Irradiation Research Articles

Влияние излучения гелий-неонового лазера на состояние клеток лимбальной зоны глаза человека

Currently, a helium-neon laser is widely used in the treatment of degenerative, inflammatory and vascular diseases of the eye. It was found that the interaction of this radiation with different tissues, as a result of complex photochemical processes, is manifested by anti-inflammatory, desensitizing, resolving effects. Also, there is a stimulating effect on the processes of reparation and trophism. However, these observations relate to the use of laser for external irradiation, when the light goes through the air and the sclera or through the cornea. Research of the effect of endo-laser direct exposure of the fiber in the cavity of the eye, where light acts directly on epithelial or limbal cells, wasn’t carry out due to objective reasons (difficulty of conducting such research directly to patients). There is currently no data on the effect of helium-neon laser on the limbal area of the eye-ball, enriched endogenous stem and progenitor cells. They help repair damaged tissues in the eye (anterior and posterior segment) at various injuries. Cell culture, grown in vitro, are free from the influences of body systems, attract researchers as a unique model to study the behavior of cells in normal but also in response to external or internal factors. Currently, scientists have learned how to obtain and difficult to cultivate a culture of cells, in-cluding tissues of the human eye. They are genetically homogeneous population of cells growing in constant conditions. The viability and morphology of cells and their ultra-structure and various molecular biological cha-racteristics can be studied in cell culture, and to find the optimal conditions of laser irradiation, does not damage the cells. In the present work the authors studied the effect of low-energy helium-neon laser irradiation (632 nm) on limbal stem cells. Conducted in vitro studies have shown that the use of low-energy helium-neon laser irrad-iation (632 nm) has a positive effect on the monolayer culture of limbal stem cells. Absence of changes in cell phenotype and high proliferative activity indicate a stimulating effect of the investigated radiation on stem and progenitor cells, leading to the result of the activation of recovery and reduction of pathological changes at the cellular and organ and tissue levels.

Low-energy laser irradiation of the head after acute cerebral infarction: Effect on self-care and related factors

Objective To observe the effect on prognostic factors of low-energy helium-neon laser irradiation of functional areas of the head in patients with acute cerebral infarction.Methods Three-hundred fifty-eight acute cerebral infarction patients were randomly divided into a regular group (120 cases),a treatment group (118 cases) and a control group (120 cases).The patients in the regular group were given the conventional neurological treatment,while those in the treatment group and control group were treated using helium-neon laser and normal red light.The functional areas of the head were irradiated at 72 h after the incidence of disease on the basis of the conventional regimen.The hemorheology,blood lipid and homocysteine (HCY) levels of patients in all 3 groups were measured before treatment,1 month afterward(M1) and 3 months afterward (M3).Their ability in activities of daily living (ADL) was also evaluated using Barthel Index (BI) at 3 months after the treatment.Results At M1 and M3 the average whole blood viscosity at high shear rate,plasma viscosity,fibrinogen triglyceride (TG),high-density lipoprotein cholesterol (HDL-C) and HCY in the treatment group were significantly lower than in the regular and control group (P ＜ 0.05).At M1,the average whole blood viscosity at low shear rate (6.41 ± 0.58 mpa * s) in the treatment group was also significantly lower than that in the other 2 groups (P ＜ 0.05).At M3,the average total cholesterol (TC) in the treatment group (4.20 ± 0.18 mmol/L) was significantly lower compared with that in the regular and control group (P ＜ 0.05).According to the average BI scores,ADL in the treatment group (27 cases of independence/48 cases of mild dependence) were significantly better than that in the regular group (18/35 cases) and the control group (20/32 cases).Conclusions Low-energy helium-neon laser irradiation of the head's functional regions may promote the recovery of neurological function for cerebral infarction patients,and can be an adjuvant therapy in clinical practice. Key words: He-Ne laser; Acute cerebral infarction; Head functional areas; Activity of daily living

Influence low-intensity laser irradiation on the ultrastructural organization of loach embryo cells

The ultrastructural organization of loach embryo cells (Misgurnus fossilis L.) at the stage of the first and the tenth embryo divisions was investigated under the influence of low intensity helium-neon laser irradiation of 5 min exposure. It was determined that the effect of laser irradiation led to ultrastructural changes: the shape of mitochondria and multivesicular bodies changes. The obtained results explain the possible mechanism of influence of low-intensity laser irradiation at the cellular level.

Helium-Neon Laser Irradiation Promotes the Proliferation and Migration of Human Epidermal Stem Cells In Vitro: Proposed Mechanism for Enhanced Wound Re-epithelialization

The present study was conducted to investigate the effects of helium-neon (He-Ne) laser irradiation on the proliferation, migration, and differentiation of cultured human epidermal stem cells (ESCs). A He-Ne laser with a wavelength of 632.8 nm is known to have photobiological effects, and is widely used for accelerating wound healing; however, the cellular mechanisms involved have not been completely understood. The ESCs were prepared from human foreskin, and irradiated by using He-Ne laser at 632.8 nm with 2 J/cm(2). The ESC proliferation, migration, and differentiation were examined by using XTT assay, scratch assay, and flow cytometry technology, respectively. The phosphorylation of extracellular signal-regulated kinases (ERK) was analyzed by using Western blotting. He-Ne laser irradiation markedly promoted cell proliferation and migration accompanied by an increase in the phosphorylation of ERK, but did not significantly influence cell differentiation. Our data indicated that photostimulation with a He-Ne laser resulted in a significant increase in human ESC proliferation and migration in vitro, which might contribute, at least partially, to accelerated wound re-epithelialization by low-level laser therapy.

HeNe laser increases the pro-inflammatory cytokines production and the in vitro phagocytosis of P. brasiliensis by macrophages.

Event Abstract Back to Event HeNe laser increases the pro-inflammatory cytokines production and the in vitro phagocytosis of P. brasiliensis by macrophages. Thiago Alves Da Costa1, Rodolfo Thomé1, Rosaria Di Gangi1, Carolina Francelin1 and Liana Verinaud1* 1 State University of Campinas, Department of Structural and Functional Biology; Institute of Biology., Brazil Cutaneous lesions caused by the fungus Paracoccidioides brasiliensis (Pb) lead to painful ulcerative wounds, which are difficult to be cured by conventional treatment with anti-fungal drugs due to their adverse effects and the multidrug resistance that some fungal isolates present (Andriole, 1998, Trent & Kirsner, 2003). We have previously showed that Helium-Neon (HeNe) laser irradiation of paracoccidioidomycotic lesions in mice accelerates the wound healing as well as the fungal clearance, which is very probably linked to the death of the fungus by macrophages (Nagib et al., 2010, Alves da Costa et al., 2013). In this study we evaluated, in vitro, whether HeNe laser irradiation was capable of modulating the phenotypic and functional profile of human and murine macrophages. Peritoneal macrophages from BALB/c mice were irradiated with different dosages of HeNe laser (0.836; 1.5 and 3J/cm2) and cultivated with Pb yeast cells (1:4, macrophage:fungi) for 6 hours. Flow cytometry analysis of macrophages showed that laser irradiation promoted an increase in the expression of TLR-4, which are molecules involved in yeast recognition and internalization, but did not alter other markers, like CD11b, F4/80, MHC-II, for example. Also, co-cultures of irradiated macrophages and Pb showed a higher phagocytic index and a higher pro-inflammatory (IFN-γ, IL-6, TNF-α) cytokines production. Similar results were obtained with a human macrophage cell line (THP1) even under the lowest incidence energy of the laser. Collectively, our results indicate that the accelerated wound healing process, observed after the treatment of paracoccidioidomycotic lesions with the HeNe laser, must be associated with a direct action of irradiation on macrophages. Acknowledgements Supported by FAPESP (#2010/08485-5, #2012/22131-7) and CAPES. References Alves da Costa, T., Di Gangi, R., Costa, M. R. S. N., Thomé, R., Paulino, L. C., Verinaud, L. (2013) . Effect of Helium-Neon (HeNe) laser irradiation on lesions in experimental paracoccidioidomycosis. Trends In Photochemistry And Photobiology, Accepted manuscript. Andriole, V. T. (1999). The 1998 Garrod lecture. Current and future antifungal therapy: new targets for antifungal agents. J. Antimicrobial Chemotherapy 44, 151-162. Nagib, P. R. N., Gameiro, J., Alves da Costa, T., Di Gangi, R., Ribeiro, J. S., Paulino, L. C., Verinaud, L. (2010). Effect of HeNe laser irradiation on extracellular matrix deposition and expression of cytokines and chemokines in paracoccidioidomycotic lesions. Photochem. Photobiol. 86, 920-924. Trent, J. T., Kirsner, R. S. (2003). Identifying and treating mycotic skin infections. Adv Skin Wound Care 16, 122-9. Keywords: Paracoccidioides brasiliensis, paracoccidioidomycotic lesions, Phagocytosis, Pro-inflammatory cytokines, HeNe Laser Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Host-pathogen interactions Citation: Alves Da Costa T, Thomé R, Di Gangi R, Francelin C and Verinaud L (2013). HeNe laser increases the pro-inflammatory cytokines production and the in vitro phagocytosis of P. brasiliensis by macrophages.. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.01003 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 29 Jun 2013; Published Online: 22 Aug 2013. * Correspondence: Prof. Liana Verinaud, State University of Campinas, Department of Structural and Functional Biology; Institute of Biology., Campinas, SP, Brazil, verinaud@unicamp.br Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Thiago Alves Da Costa Rodolfo Thomé Rosaria Di Gangi Carolina Francelin Liana Verinaud Google Thiago Alves Da Costa Rodolfo Thomé Rosaria Di Gangi Carolina Francelin Liana Verinaud Google Scholar Thiago Alves Da Costa Rodolfo Thomé Rosaria Di Gangi Carolina Francelin Liana Verinaud PubMed Thiago Alves Da Costa Rodolfo Thomé Rosaria Di Gangi Carolina Francelin Liana Verinaud Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Мембранозалежні процеси в еритроцитах крові хворих на туберкульоз легень за впливу гелій-неонового лазерного випромінювання

The effect of frequency modulated and unmodulated He-Ne laser irradiation of blood of patients with destructive pulmonary tuberculosis in the intensive phase of chemotherapy on the level of endogenous intoxication, the processes of lipid peroxidation and activity of antioxidant enzymes was investigated. Analysis of the results of study conducted after the application of intravenous laser irradiation of blood by helium-neon laser with different frequency modulations on the background of standardized chemotherapy demonstrated that the application of frequency modulation has a pronounced positive effect on the balance of prooxidant-antioxidant processes in patients with the first diagnosed pulmonary tuberculosis, compared to single chemotherapy and influence of modulated helium-neon laser irradiation of blood. The frequency-dependent stimulation of antioxidant system and the level of inhibition of lipid peroxidation in erythrocyte membranes under the influence of laser frequency modulation on a background of chemotherapy was detected. Marked intensification of compensatory processes, especially when using a helium-neon laser with frequency modulation 5 kHz and 100 kHz, was found. Keywords: erythrocytes, laser radiation, lipid peroxidation, antioxidant protection.

Stimulatory effect of helium–neon laser irradiation on human umbilical vein endothelial cells

Stimulatory effect of helium–neon laser irradiation on human umbilical vein endothelial cells

Change of light reflection from the surface of 6H-SiC single crystals under ultraviolet radiation (photonic transistor)

The excitation spectra of specular photoreflection of a helium-neon laser radiation from the surface of 6H-SiC single crystals at the Brewster angle with the polarization parallel to the plane of incidence have been investigated. The obtained results on the change in the intensity of the reflected light indicate a decrease in the optical refractive index of silicon carbide under ultraviolet radiation. It has been found that there is a correlation of the photoreflection excitation spectra with the photoconductivity spectra of the material at low intensities of the reflected light and ultraviolet radiation. It has been revealed that an increase in the intensity of ultraviolet optical pumping leads to a linear increase in the photomodulation of the reflected red light with a maximum at 632.8 nm.

HELIUM-NEON LASER PROVIDE A CHANGE TO THE RADIATION RESISTANCE OF BIOLOGICAL CELLS

Розглянуто публікації, присвячені підвищенню радіаційної стійкості клітинних культур шляхом їх опромінення лазером. Показано, що реалізуються протилежні результати в залежності від того, чи використовуються інтенсивност, менші ніж “дотеплова” величина, або навпаки.

Mutation breeding of Bacillus subtilis YTB4 with high yield of multienzyme complex

Helium-neon (He-Ne) laser irradiation is a highly efficient mutation breeding technology and is widely applied to various fields of biological science. Using Bacillus subtilis YTB4 with high yield of multienzyme complex as original strain, mutation breeding was carried out by He-Ne laser irradiation in this study. Based on the study of the strains’ survival rate and positive mutation frequency, the appropriate irradiation dose was determined. The mutant YTB4A was selected through see-through circle way and enzyme activity determination. Compared with the original strain the activities of cellulase, protease and amylase increased by 265.14, 35.42 and 172.78%, respectively. In addition, the hereditary stability test showed that the activities of multienzyme complex were stable and that there was no reverse mutation after 25 generations. Key words: Bacillus subtilis, multienzyme complex, He-Ne laser, mutation, hereditary stability.

High-power helium–neon laser irradiation inhibits the growth of traumatic scars in vitro and in vivo

This study explored the inhibitory effect of the high-power helium-neon (He-Ne) laser on the growth of scars post trauma. For the in vitro study, human wound fibroblasts were exposed to the high-power He-Ne laser for 30 min, once per day with different power densities (10, 50, 100, and 150 mW/cm(2)). After 3 days of repeated irradiation with the He-Ne laser, fibroblast proliferation and collagen synthesis were evaluated. For in vivo evaluation, a wounded animal model of hypertrophic scar formation was established. At postoperative day 21, the high-power He-Ne laser irradiation (output power 120 mW, 6 mm in diameter, 30 min each session, every other day) was performed on 20 scars. At postoperative day 35, the hydroxyproline content, apoptosis rate, PCNA protein expression and FADD mRNA level were assessed. The in vitro study showed that the irradiation group that received the power densities of 100 and 150 mW/cm(2) showed decreases in the cell proliferation index, increases in the percentage of cells in the G0/G1 phase, and decreases in collagen synthesis and type I procollagen gene expression. In the in vivo animal studies, regions exposed to He-Ne irradiation showed a significant decrease in scar thickness as well as decreases in hydroxyproline levels and PCNA protein expression. Results from the in vitro and in vivo studies suggest that repeated irradiation with a He-Ne laser at certain power densities inhibits fibroblast proliferation and collagen synthesis, thereby inhibits the growth of hypertrophic scars.

Effect of helium neon laser irradiation combined with boric acid wet packing on elder patients with pressure ulcers

Objective To investigate the clinical effect of helium neon laser irradiation combined with boric acid wet packing on elder patients with pressure ulcers.Methods 52 cases of elderly patients with pressure ulcer were randomly divided into treatment group and control group.The control group was treated with boric acid wet packing after the wound debridement.The treatment group was treated with the helium neon laser irradiation on the pressure ulcer surface 20 minutes after the wound debridement and then boric acid wet packing once a day.Both groups received comprehensive treatment and nursing measures of pressure ulcers.Pressure ulcer healing was observed for 30 days.Results The effective rate of the treatment group was 96.2％ and that of the control group was 69.2％.Clinical effect of the treatment group was better than that of the control group,and the difference was statistically significant( x2 =4.837,P ＜0.05 ).The effect initiating time of the treatment group was lower than the control group [ ( 12.19 ± 6.40) d vs ( 19.36 ± 9.30) d],and the difference was statistically significant ( t =- 2.425,P ＜ 0.05 ).Conclusions Helium neon laser irradiation combined with boric acid wet packing can promote wound healing of pressure ulcers in elder patients,shorten course of disease. Key words: Helium neon laser irradiation,small dose; Boric acid; Elder patients; Pressure ulcers

Induction of primitive pigment cell differentiation by visible light (helium–neon laser): a photoacceptor-specific response not replicable by UVB irradiation

Solar lights encompass ultraviolet (UV), visible, and infrared spectrum. Most previous studies focused on the harmful UV effects, and the biologic effects of lights at other spectrums remained unclear. Recently, lights at visible region have been used for regenerative purposes. Using the process of vitiligo repigmentation as a research model, we focused on elucidating the pro-differentiation effects induced by visible light. We first showed that helium-neon (He-Ne) laser (632.8 nm) irradiation stimulated differentiation of primitive pigment cells, an effect not replicable by UVB treatment even at high and damaging doses. In addition, significant increases of mitochondrial DNA copy number and the regulatory genes for mitochondrial biogenesis were induced by He-Ne laser irradiation. Mechanistically, we demonstrated that He-Ne laser initiated mitochondrial retrograde signaling via a Ca(2+)-dependent cascade. The impact on cytochrome c oxidase within the mitochondria is responsible for the efficacy of He-Ne laser in promoting melanoblast differentiation. Taken together, we propose that visible lights from the sun provide important environmental cues for the relatively quiescent stem or primitive cells to differentiate. In addition, our results also indicate that visible light may be used for regenerative medical purposes involving stem cells.

Potential for Transcranial Laser or LED Therapy to Treat Stroke, Traumatic Brain Injury, and Neurodegenerative Disease

Near-infrared (NIR) light passes readily through the scalp and skull and a small percentage of incident power density can arrive at the cortical surface in humans.1 The primary photoreceptors for red and NIR light are mitochondria, and cortical neurons are exceptionally rich in mitochondria. It is likely that brain cells are ideally set up to respond to light therapy. The basic biochemical pathways activated by NIR light, e.g., increased adenosine-5′-triphosphate (ATP) production, and signaling pathways activated by reactive oxygen species, nitric oxide release, and increased cyclic adenosine monophosphate (AMP) all work together to produce beneficial effects in brains whose function has been compromised by ischemia, traumatic injury, or neurodegeneration. One of the main mechanisms of action of transcranial light therapy (TLT) is to prevent neurons from dying, when they have been subjected to some sort of hypoxic, traumatic, or toxic insult. This is probably because of light-mediated upregulation of cytoprotective gene products such as anti-oxidant enzymes, heat shock proteins, and anti-apoptotic proteins. Light therapy in vitro has been shown to protect neurons from death caused by methanol,2 cyanide or tetrodotoxin,3 and amyloid beta peptide.4 There is also probably a second mechanism operating in TLT; increased neurogenesis. Neurogenesis is the generation of neuronal precursors and birth of new neural cells.5 Two key sites for adult neurogenesis include the subventricular zone (SVZ) of the lateral ventricles, and the subgranular layer (SGL) of the dentate gyrus in the hippocampus.6 Neurogenesis can be stimulated by physiological factors, such as growth factors and environmental enrichment, and by pathological processes, including ischemia and neurodegeneration.7 Adult neurogenesis (in the hippocampus particularly) is now recognized as a major determinant of brain function both in experimental animals and in humans. Neural progenitor cells in their niche in the SGL of the dentate gyrus give birth to newly formed neurons that are thought to play a role in brain function, particularly in olfaction and in hippocampal-dependent learning and memory.8 In small animal models neurogenesis can be readily detected by incorporation of bromodeoxyuridine (BrdU), injected before euthanasia, into proliferating brain cells. Increased neurogenesis after TLT, has been demonstrated in a rat model of stroke,9 and in the Hamblin laboratory after TLT for acute traumatic brain injury (TBI) in mice (W. Xuan, T. Ando, et al., unpublished data). These two mechanisms of action of TLT in ameliorating brain damage (prevention of neuronal death and increased neurogenesis) have motivated studies in both animals and humans for diverse brain disorders and diseases. TLT for acute stroke is the most developed,10 but acute TBI has also been shown to benefit from TLT.11 These areas are reviewed further.

Development and evaluation of an optical fibre-based helium-neon laser irradiation system for tissue regeneration: A pilot study

Low level laser therapy is being extensively used to treat various medical ailments including wound healing. In the present study, an optical fibre-based helium-neon (He-Ne) laser irradiation system was designed, developed and evaluated for optimum tissue repair on mice excision wounds. Circular wounds of 15 mm diameter were created on the dorsum of animals and single exposure of uniformly distributed laser beam was administered at 1, 2 and 3 J/cm2 to the respective test groups with suitable controls. Progression of healing was monitored by measuring wound contraction and mean healing time. Significant reduction in wound size and mean healing time (p <0.001) were observed in the test groups for the laser dose of 2 J/cm2 compared to the unilluminated controls, suggesting the suitability of this dose.

Kinetic Analysis and Modeling of Daptomycin Batch Fermentation by Streptomyces roseosporus

In this study, Streptomyces roseosporus was subjected to helium-neon (He-Ne) laser (632.8nm) irradiation to improve the production ability of extracellular antibiotic daptomycin. Under the optimum irradiation dosage of 18mW for 22min, a stable positive mutant strain S. roseosporus LC-54 was obtained. The maximum A21978C (daptomycin is a semisynthetic antimicrobial substance derived from the A21978C complex) yield of this mutant strain was 296mg/l, which was 146% higher than that of the wild strain. The mutant strain grew more quickly and utilized carbohydrate sources more efficiently than the wild strain. The batch culture kinetics was investigated in a 7l bioreactor. The logistic equation for growth, the Luedeking-Piret equation for daptomycin production, and Luedeking-Piret-like equations for carbon substrate consumption were established. This model appeared to provide a reasonable description for each parameter during the growth phase and fitted fairly well with the experiment data.

The long road to commercialization of Bt brinjal (eggplant) in India

Exposure to laser irradiation on seeds brings about the changes in agronomical characteristics of the plants. Solanum melongena L. var. Mattu Gulla, a variety of brinjal is of high economic value due to its unique colour and flavour. The aim of the study was to understand the influence of Helium-Neon (He-Ne) laser irradiation on agronomical characters of Solanum melongena L. var. Mattu Gulla in the field conditions. Various growth characteristics including seed germination percentage, survival rate, plant height, number of branches, and flowers and fruits were estimated during different developmental stages of the brinjal. In addition, the chlorogenic acid content of fruits obtained from the laser irradiated seeds were quantified using reversed-phase high-performance liquid chromatography (RP- HPLC). The plants from the seeds irradiated with different doses (20, 25 and 30 J/cm2) of He-Ne laser showed significant enhancement on the growth characteristics when compared to the non-irradiated control groups. He-Ne laser irradiation also improved the yield characteristics of the plants significantly in in vivo conditions in comparison with control group. 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed using methanolic extract of matured fruit of Mattu Gulla on HepG2 and fibroblast cell lines. The IC50 values of fruit extract from laser irradiated groups were found to be similar to non-irradiated control groups. Chlorogenic acid content was found to be higher in 20 J/cm2 and lower in 30 J/cm2 treated fruit tissue. The current study thus elucidates the role of He-Ne laser as a biostimulator on brinjal var. Mattu Gulla not only in the in vitro conditions but also in the in vivo field conditions.

Effect of Helium-Neon Laser Irradiation on Hair Follicle Growth Cycle of Swiss Albino Mice

We report the results of a study carried out to investigate the effect of helium-neon (He-Ne) laser (632.8 nm) irradiation on the hair follicle growth cycle of testosterone-treated and untreated mice. Both histology and optical coherence tomography (OCT) were used for the measurement of hair follicle length and the relative percentage of hair follicles in different growth phases. A positive correlation (R = 0.96) was observed for the lengths of hair follicles measured by both methods. Further, the ratios of the lengths of hair follicles in the anagen and catagen phases obtained by both methods were nearly the same. However, the length of the hair follicles measured by both methods differed by a factor of 1.6, with histology showing smaller lengths. He-Ne laser irradiation (at ∼1 J/cm²) of the skin of both the control and the testosterone-treated mice was observed to lead to a significant increase (p < 0.05) in % anagen, indicating stimulation of hair growth. The study also demonstrates that OCT can be used to monitor the hair follicle growth cycle, and thus hair follicle disorders or treatment efficacy during alopecia.

Experimental Determination of the Raman Sampling Depth in Zirconia Ceramics

This study provides experimentally determined values for the actual micro-Raman spectroscopy sampling depth in zirconia ceramics (ZrO2) via line scans on a wedge-shaped sample. Common instrumental settings with metallurgical objective lenses in dry air, argon-ion, and helium-neon laser radiation of approximately 10 mW were chosen. Under those conditions effective sampling depths, defined as the depth at which 99% of the information is recorded, range from 20 to more than 50 microm, depending on the numerical aperture of the lens and the laser wavelength. These results elucidate the pitfalls of the investigation of surface phenomena in zirconia ceramics such as low-temperature degradation or mechanically induced phase transformations by Raman spectroscopy.

The effect of low-level helium-neon (HeNe) laser radiation on the secretion of cytokines that promote chronic graft rejection – An in vitro study

Basically chronic graft rejection is a type-IV hypersensitivity process, also known as delayed-type hypersensitivity (DTH). The role of cytokines secreted from T-cell lymphocytes is known in this process. Among these cytokines, the biggest role belongs to the transforming growth factor beta (TGF-β) and interleukin-2 (IL-2). Many studies have been published on the effect of low level lasers (LLL) on DTH, but not many have focused on the mechanism of LLL effects on DTH, which is also the mechanism of chronic graft rejection. If LLL are able to decrease the level of cytokines effectively in this process, then it would be possible to use it to prevent chronic graft rejection, either alone or combined with routine treatments, to give fewer treatment side effects. This study was designed to evaluate the effect of LLL on the amount of cytokines secreted by T-cells after stimulation in vitro by foreign antigens. Human peripheral blood mononuclear cells were cultured and the cells were divided into 4 groups (control #1, control #2, case #1, and case #2). Control group #1 was the base group and the cells received neither stimulation nor irradiation. Control group #2 was only stimulated by phytohaemagglutinin (PHA); no laser irradiation was carried out. Case group #1 received daily laser irradiation for a total of 9 days, starting one day prior to stimulation with PHA. Case group #2 was given daily laser irradiation for a total of 7 days, starting one day after the stimulation with PHA. Both case groups were irradiated with the same helium-neon (HeNe) laser device (parameters: 632.8 nm, 4 J/cm2). On days 3, 5 and 8 of the experiment, the level of the cytokines interleukins IL-2 and IL-12, TGF-β and interferon gamma (INT-γ) were checked by the ELISA method in all the groups and the data were analyzed using SPSS 11.5. Our results showed that low-level irradiation can decrease the level of cytokines that are known to be stimulators for chronic graft rejection (IL-2, IL-12, TGF-β and INF-γ). However, we did not find any significant differences between our two case groups. Although this study suggests the successful role of LLL in preventing chronic graft rejection by affecting the cytokines known to have significant role in this process, further experimental studies and dosage determination experiments are required before using LLL in clinical treatment procedures. Bei der chronischen Abstoßung von Transplantaten handelt es sich im wesentlichen um eine Typ-4-Überempfindlichkeitsreaktion, auch bekannt als verzögerte Überempfindlichkeit (DTH=delayed-type hypersensitivity). Es ist bekannt, dass dabei die Zytokinproduktion der T-Zellen eine wichtige Rolle spielt. Zu den wichtigsten Zytokinen gehören der transformierende Wachstumsfaktor (TGF-β=transforming growth factor beta) und Interleukin 2 (IL-2). Viele bereits publizierte Studien haben zwar den Effekt von Low-Level-Laserstrahlung auf die DTH untersucht, jedoch sind die dabei wirkenden Mechanismen, die auch der chronischen Abstoßung zugrunde liegen, nur selten betrachtet worden. Wenn es gelingen könnte, mit einer Low-Level-Lasertherapie die Zytokinproduktion effektiv zu verringern, so könnte diese Therapie entweder allein oder in Kombination mit anderen herkömmlichen Therapien eingesetzt werden, um chronische Transplantat-Abstoßungen zu vermeiden. Ziel der vorliegenden In-vitro-Studie war es daher, zu untersuchen, in welchem Maße die Bestrahlung mit einem Low-Level-Laser die Zytokinproduktion der T-Zellen nach Stimulation mit einem Fremdantigen beeinflusst. Humane mononukleäre Zellen des peripheren Blutes (PBMC) wurden mit den üblichen Standardmethoden kultiviert und in vier Gruppen (2 Kontrollgruppen, 2 Versuchsgruppen) untersucht. Die Zellen der Kontrollgruppe 1 wurden weder stimuliert noch bestrahlt. Die Zellen der Kontrollgruppe 2 wurden täglich mit Phytohämagglutinin (PHA) stimuliert, jedoch nicht laserbestrahlt. Proben der Versuchsgruppen 1 und 2 wurden täglich mit einem HeNe-Laser (konstante Laserparameter: 632.8 nm, 4 J/cm2) bestrahlt und mit PHA stimuliert, wobei mit der Bestrahlung entweder einen Tag vor Beginn der PHA-Stimulation (Versuchsgruppe 1) oder einen Tag nach Beginn der PHA-Stimulation (Versuchsgruppe 2) gestartet wurde. Am 3., 5. und 8. Tag des Experimentes wurde in allen Untersuchungsgruppen der Zytokingehalt von Interleukin 2 und 12 (IL-2, IL-12), TGF-β und Gamma-Interferon (INT-γ) mittels ELISA-Methode bestimmt. Die statistische Auswertung erfolgte mit Hilfe von SPSS 11.5. Mit der durchgeführten Low-Level-Laserbestrahlung konnte in vitro die Produktion der Zytokine IL-2, IL-12, TGF-β und INF-γ, von denen bekannt ist, dass sie chronische Abstoßungsreaktionen fördern, verringert werden. Jedoch wurden keine signifikanten Unterschiede zwischen den beiden Versuchsgruppen gefunden. Die vorgestellte Studie unterstützt die Annahme, dass mit einer Low-Level-Lasertherapie möglicherweise eine chronische Transplantat-Abstoßung vermieden werden kann. Es sind allerdings weitere Studien, insbesondere zur Laserdosimetrie nötig, bevor diese Therapieform in die klinische Praxis überführt werden kann.