[Hereditary optic neuropathy associated with demyelinating diseases of the central nervous system]. / Nasledstvennaya opticheskaya neiropatiya v sochetanii s demieliniziruyushchimi zabolevaniyami tsentral'noi nervnoi sistemy.

Demyelinating optic neuritis and hereditary optic neuropathy (HON) take a leading place among the diseases, the leading clinical syndrome of which is bilateral optic neuropathy with a simultaneous or sequential significant decrease in visual acuity. Optic neuritis can occur at the onset or be one of the syndromes within multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), and myelin oligodendrocyte glycoprotein (MOG) antibody disease (MOGAD). HON are a group of neurodegenerative diseases, among which the most common variants are Leber's hereditary optic neuropathy (LHON), associated with mitochondrial DNA (mtDNA) mutations, and autosomal recessive optic neuropathy (ARON), caused by nuclear DNA (nDNA) mutations in DNAJC30. There are phenotypes of LHON «plus¼, one of which is the association of HON and CNS demyelination in the same patient. In such cases, the diagnosis of each of these diseases causes significant difficulties, due to the fact that in some cases there are clinical and radiological coincidences between demyelinating and hereditary mitochondrial diseases.

[Long-term changes in morphological and functional parameters of the optic nerve in patients with various genetic variants of hereditary optic neuropathies]. / Dolgosrochnaya dinamika morfofunktsional'nykh pokazatelei zritel'nogo nerva u patsientov s razlichnymi geneticheskimi variantami nasledstvennykh opticheskikh neiropatii.

Leber's hereditary optic neuropathy (LHON) and autosomal recessive optic neuropathy (ARON) are degenerative diseases of the optic nerve caused by mutations in nuclear or mitochondrial DNA (nDNA, mtDNA). The clinical picture of these diseases is similar, but there are some differences in how the visual functions change in patients with different molecular genetic variants of hereditary optic neuropathies (HON). PURPOSE: This study evaluates the long-term changes in morphological and functional parameters in patients with different genetic variants of HON. MATERIAL AND METHODS: The study included 84 patients (165 eyes) with a genetically confirmed LHON or ARON diagnosis. The patients underwent best-corrected visual acuity (VA) test, color vision (CV) examination, computerized perimetry using the program for low vision assessment, optical coherence tomography (OCT). RESULTS: Over the course of the follow-up (60 months or longer) HON patients were revealed to have higher VA in c.152A>G and m.14484T>C mutations compared to mutations m.11778G>A and m.3460G>A. The final VA 0.5 or higher in patients with c.152A>G and m.14484T>C mutations in 54 and 71% of cases, and only in 6 and 13% of cases - with m.11778G>A and m.3460G>A mutations. Direct correlation was determined between minimal VA in the first year after disease onset and the final VA (K=0.67; p<0.001). In all patients with the investigated mutations CV recovered slightly quicker than VA. CONCLUSION: HON associated with c.152A>G and m.14484T>C mutations have better prognosis compared to LHON caused by m.11778G>A and m.3460G>A mutations. Vision recovery prognosis is worse in patients who had significant decrease of visual acuity at the disease onset. OCT findings reveal preservation of visual functions in all mutations.

[Rare pathogenic nucleotide variants of mitochondrial DNA associated with Leber's hereditary optic neuropathy]. / Redkie patogennye nukleotidnye varianty mitokhondrial'noi DNK, assotsiirovannye s nasledstvennoi opticheskoi neiropatiei Lebera.

Patients with Leber Hereditary Optic Neuropathy (LHON) in most cases have one of the three most common mutations: m.11778G>A in the ND4 gene, m.3460G>A in the ND1 gene, or m.14484T>C in the ND6 gene. According to the international Mitomap database, in addition to these three most common mutations, there are 16 other primary mutations that are even more rare. There are nucleotide substitutions that are classified as candidate or conditionally pathogenic mutations. Their involvement in the disease development is not proven due to insufficient research. Moreover, in many publications, the authors describe new primary and potential mitochondrial DNA mutations associated with LHON, which are not yet included in the genetic data bases. This makes it possible to expand the diagnostic spectrum during genetic testing in the future. The advancements in genetic diagnostic technologies allow confirmation of the clinical diagnosis of LHON. The importance of genetic verification of the disease is determined by the existing problem of differential diagnosis of hereditary optic neuropathies with optic neuropathies of a different origin.

[Leber's hereditary optic neuropathy clinical features in patients with mitochondrial DNA m.13513G>A candidate mutation]. / Klinicheskie osobennosti nasledstvennoi opticheskoi neiropatii Lebera u patsientov s kandidatnoi mutatsiei m.13513G>A v mitokhondrial'noi DNK.

Leber's hereditary optic neuropathy (LHON) is caused by primary mtDNA by both primary mtDNA mutations and new mtDNA mutations. The last ones, when detected in several independent LHON families, receive candidate status. The description of new LHON-associated mtDNA mutation is relevant. PURPOSE: To determine the LHON clinical features in patients with the m.13513G>A mutation and to estimate the patients' proportion with this pathogenic variant in the LHON patients' sample. MATERIAL AND METHODS: The study included 5 LHON patients, associated with m.13513G>A mutation in the ND5 gene in the heteroplasmic state. A standard examination was performed, including color blindness test, visual fields test, spectral optical coherence tomography. RESULTS: LHON, associated with m.13513G>A in the heteroplasmic state in the range of 25-60%, is characterized by visual impairment without additional neurological or other extraocular symptoms. Visual recovery to 0.3-1.0 presents in all patients; the visual recovery onset occurs between 12 and 20 months from the disease manifestation. The decrease of the central scotoma size and its density and the color vision improvement are also observed as well as the average retinal nerve fibers layer and ganglion cell complex thickness decrease. The m.13513G>A mutation frequency is 5% in 100 LHON patients' sample and 22.5% in 22 LHON patients with rare and candidate mtDNA mutations. CONCLUSION: The m.13513G>A mutation can be considered as primary LHON mutation. The list of pathogenic variants recommended for testing LHON can include this mutation. The m.13513 G>A mutation determines the mild LHON course and good visual functions prognosis in these patients.

[Bilateral vision loss on programmed hemodialysis (clinical observation)]. / Dvustoronnyaya poterya zreniya na fone programmnogo gemodializa (klinicheskoe nablyudenie).

The most common complication of hemodialysis is blood pressure decrease, which is an ischemic optic neuropathy risk factor. The article presents a case study of sequential bilateral ischemic optic neuropathy with the development of amaurosis as a result of arterial hypotension against the background of programmed hemodialysis. Differential diagnosis in bilateral visual impairment is discussed.

[Modern prerequisites for creating a collagen-based artificial analogue of the corneal stroma]. / Sovremennye predposylki sozdaniya iskusstvennogo analoga stromy rogovitsy na osnove kollagenovogo materiala.

Despite the fact that various collagen biomaterials have been actively used in ophthalmology for more than 30 years, the problem of creating a material that could replace the donor cornea have not been solved. Recent advances in the field of tissue engineering and regenerative medicine have shifted the focus of approaches to solving the problem of creating an artificial cornea towards laying conditions for the restoration of its specific layers through mechanisms of its own cellular regeneration. In this regard, extracellular matrices based on collagen are gaining popularity. This review discusses general limitations and advantages of collagen for creating an artificial cornea.

[Metabolic disorders in hereditary optic neuropathies]. / Metabolicheskie narusheniya pri nasledstvennykh opticheskikh neiropatiyakh.

Folate metabolism disorders are known to have a potential involvement in the pathophysiology of mitochondrial diseases. Many researchers suggest that profound systemic folate deficiency may contribute to mitochondrial folate deficiency. Folic acid metabolism is closely related to vitamin B12 and homocysteine. Considering that hereditary optic neuropathies (HON) are mitochondrial diseases, it is important to study the folate status, the content of vitamin B12 and homocysteine in patients with this pathology. OBJECTIVE: To compare the content of folic acid, vitamin B12 and homocysteine in the blood serum of patients with Leber's hereditary optic neuropathy (LHON) and autosomal recessive optic neuropathy (ARON), optic neuropathy of other genesis, and the comparison group. MATERIAL AND METHODS: The study involved 58 patients with LHON and ARON, the control group of 49 patients with ischemic, inflammatory, traumatic and compressive optic neuropathies, and the comparison group of 20 healthy volunteers. RESULTS: A decrease in blood folic acid levels was revealed (4.0±1.6 ng/mL) in patients with HON compared to the control group (p=1.3·10-8) and the comparison group (p=1·10-17). The content of vitamin B12 in patients with HON was 380.8±168.1 pg/mL, which was significantly lower than in the comparison group (p=0.0001). The homocysteine content was 14.1±5.6 µmol/L in patients with HON, which was significantly higher than in the control group (p=0.0007) and the comparison group (p=0.000003). At the same time, an increase in homocysteine level of more than 10 µmol/L was revealed in 75% of patients with HON. Similar metabolic disorders were found in groups with various mutations in mitochondrial and nuclear DNA. CONCLUSION: Patients with HON showed marked decrease in the levels of folic acid and vitamin B12, as well as hyperhomocysteinemia. It is very important to identify the causes of metabolic disorders in order to determine the role of folate deficiency in the development of HON, as well as the possibility of its pharmacological treatment.

[Electrophysiological and psychophysical studies in assessment of visual functions in patients with hereditary optic neuropathy]. / Elektrofiziologicheskie i psikhofizicheskie issledovaniya v otsenke zritel'nykh funktsii pri nasledstvennoi opticheskoi neiropatii.

PURPOSE: To study the capabilities of electrophysiological and psychophysical examination methods for assessment of the functional state of ganglion cells, retina and optic nerve in patients with hereditary optic neuropathy (HON). MATERIAL AND METHODS: The study included 60 patients (118 eyes) with a genetically confirmed diagnosis of HON. All study patients underwent visual field test (VFT), spectral optical coherence tomography (OCT), flash and pattern visual evoked potentials (VEP) (Flash-VEP, FVEP; Pattern-VEP, PVEP), photopic electroretinography with photonegative response (PhNR) registration and the color vision test. In 24 patients (46 eyes), these parameters were assessed before the start of treatment and one year later. The treatment involved the mitochondria-targeted antioxidant SkQ1 - plastoquinonyl-decyl-triphenylphosphonium bromide (PDTP) in the form of eye drops. RESULTS: The main PVEP components for 1.0° and 0.3° were registered in 20% and in 14% of patient eyes with HON and high visual functions, respectively. After one year of PDTP use, a significant decrease in P100 peak latency was found only in the group with disease duration of ≤1.5 years as of the time of treatment start (p<0.05). Significant differences were observed in the PhNR amplitude (p<0.004) between patients of the main and the control groups, as well as in the PhNR amplitude between patients with visual acuity of ≤0.1 and ≥0.13 (p<0.01). Patients with high visual functions were found to have a correlation between the PhNR amplitude, GCC thickness and the global loss index (GLV). CONCLUSION: Along with VFT, OCT and color vision tests, electrophysiological studies are one of the main methods of examining patients with HON. After one year of PDTP use, there was a significant decrease in the FVEP P2 peak latency in the group with a disease duration of ≤1.5 years as of the time of treatment start. The PhNR amplitude in patients with high visual functions was found to correlate with structural changes in the ganglion cell layer and the retinal nerve fiber layer.

[Possibilities of an experimental damaging effect on the retinal pigment epithelium]. / Vozmozhnosti eksperimental'nogo modelirovaniya povrezhdayushchego vozdeistviya na pigmentnyi epitelii setchatki.

PURPOSE: To simulate the damaging effect on retinal pigment epithelium (RPE) in an experiment studying the effect of human neuronal precursors (NPs). MATERIAL AND METHODS: The study was carried out on 31 rabbits (31 eyes) of the Chinchilla breed, which were divided into 3 groups: the 1st group received a subretinal injection of balanced saline solution (BSS); the 2nd group - subretinal injection of BSS with vitrectomy, displacement of the injection bladder away from the injection site using a perfluororganic compound (PFOC) and laser coagulation; the 3rd group - subretinal injection of a culture of NPs using the same method as in the group 2. All rabbits were observed for 21 days using ophthalmoscopy, optical coherence tomography (OCT) and autofluorescence (AF). RESULTS: In the 1st group, 4 out of 5 rabbits were observed to have total retinal detachment and vitreoretinal proliferative processes in the early postoperative period after subretinal injection of the BSS. In the 2nd group, OCT and AF revealed atrophy of the outer and inner layers of the retina as well as disorganization of the photoreceptors-RPE-Bruch's membrane complex in the area of injection on the 21 day after the operation. In the 3rd group, the OCT data obtained during the 21 days of observation showed that a hyperreflective zone at the level of the RPE-Bruch's membrane complex corresponding to the NPs injection site was preserved, while there was a partial loss of the outer retinal layers - but of a smaller volume compared to the BSS injection. The suggested method of subretinal injection led to a reduced number of complications: in the 1st group, postoperative complications amounted to 80%, while in the 2nd and 3rd groups - 45%. CONCLUSION: The study proposes a new method for retinal injection of BSS, which can help reduce RPE degeneration patterns and possible postoperative complications, thus increasing research efficiency. Subretinal injection of a culture of neuronal precursors derived from human induced pluripotent stem cells (iPSCs) in an experiment can serve as a universal model for studying the survival and integration of stem cells.

Structure-resistive property relationships in thin ferroelectric BaTiO[Formula: see text] films.

A combined study of local structural, electric and ferroelectric properties of SrTiO[Formula: see text]/La[Formula: see text]Sr[Formula: see text]MnO[Formula: see text]/BaTiO[Formula: see text] heterostructures was performed by Piezoresponse Force Microscopy, tunneling Atomic Force Microscopy and Scanning Tunneling Microscopy in the temperature range 30-295 K. The direct correlation of film structure (epitaxial, nanocrystalline or polycrystalline) with local electric and ferroelectric properties was observed. For polycrystalline ferroelectric films the predominant polarization state is defined by the peculiarity of screening the built-in field by positively charged point defects. Based on Scanning Tunneling Spectroscopy results, it was found that a sequent voltage application provokes the modification of local resistive properties related to the redistribution of point defects in thin ferroelectric films. A qualitative analysis of acquired Piezoresponse Force Microscopy, tunneling Atomic Force Microscopy and Scanning Tunneling Microscopy images together with Scanning Tunneling Spectroscopy measurements enabled us to conclude that in the presence of structural defects the competing processes of electron injection, trap filling and the drift of positively charged point defects drives the change of resistive properties of thin films under applied electric field. In this paper, we propose a new approach based on Scanning Tunneling Microscopy/Spectroscopy under ultrahigh vacuum conditions to clarify the influence of point defects on local resistive properties of nanometer-thick ferroelectric films.

[Characteristics of changes in retinal and optic nerve microvascularisature in Leber hereditary optic neuropathy patients seen with optical coherence tomography angiography]. / Osobennosti mikrososudistykh izmenenii setchatki i zritel'nogo nerva u patsientov s nasledstvennoi opticheskoi neiropatiei po dannym opticheskoi kogerentnoi tomografii-angiografii.

PURPOSE: To investigate the features of various parameters of the density of retinal blood vessels, optic nerve head (ONH) and peripapillary region in hereditary optic neuropathy (HON) patients revealed with optical coherence tomography angiography (OCTA). MATERIAL AND METHODS: The study included 29 HON patients divided into three groups based on symptoms duration (less than 1 year; 1-5 years, more than 5 years) and visual acuity (0.5-1.0; 0.04-0.4; 0.03 and lower). Relative macular, optic disc and peripapillary vessel density (VD, %) was assessed by OCTA (xR Avanti, Optovue Inc., USA). RESULTS: Significant progressive VD reduction in superficial capillary plexus (SCP) was detected in all parafovea sectors and in the temporal sector of perifovea over the course of disease progression. No significant differences of these parameters were found in correlation with visual acuity. Patients with VA of 0.5-1.0 turned out to have greater VD in deep capillary plexus (DCP), whereas no differences were found in relation to the duration of HON. A strong significant correlation between the SCP and DCP VD only in central foveal area was revealed in all groups depending on the VA and symptoms duration. Over the course of HON progression, VD in the temporal sector and in temporal segments of superior and inferior sectors has gradually reduced. In patients with VA of 0.5-1.0, the retinal nerve fibers layer (RNFL) thickness in the temporal sector and optic nerve VD was notably greater compared to patients with lower VA. The most significant correlation was established between VA and structural changes (K=0.75, p<0.001) and VD in the temporal sector (K=0.57-0.61, p<0.001). CONCLUSION: The obtained data suggest that derivative microvascular changes play an active role in the clinical progression of the disease.

[Dysthyroid optic neuropathy: surgical treatment potential]. / Opticheskaya neiropatiya pri endokrinnoi oftal'mopatii: vozmozhnosti khirurgicheskogo lecheniya.

PURPOSE: To evaluate the effectiveness of bony orbital decompression in patients with dysthyroid optic neuropathy (DON). MATERIAL AND METHODS: The study analyzed 255 patients with thyroid eye disease (TED) and bony orbital decompression. Those among them who had DON as an indication for surgery were investigated further. Patients underwent standard ophthalmological examination, computer perimetry, color vision assessment using Ishihara tables, relative afferent pupillary defect (RAPD), computed tomography (CT) of the orbit, and in some cases optical coherence tomography (OCT) of the optic nerve. RESULTS: Final analysis included 31 patients (52 eyes). On 13 orbits, only lateral wall decompression was performed, and medial wall decompression was the only intervention in 7 orbits. In other cases, these techniques were performed either simultaneously - in 14 orbits, or alternately - in 18 orbits. In the postoperative period, all patients showed significant positive dynamics in terms of visual acuity, visual field, and proptosis. In all cases, decrease of the amount of orbital inflammation was observed. Exophthalmos significantly decreased after surgery and averaged 20.5±3.1 mm, which is 4.7 mm less than the initial one. All changes were statistically significant (p<0.01). CONCLUSION: Bony orbital decompression is an effective and safe treatment option for DON resistant to high doses of glucocorticoids. In the vast majority of cases, this intervention is the only way to improve and stabilize visual function in this severe category of patients.

[Structural and functional changes in the retina and optic nerve in patients with toxic optic neuropathy caused by acute methanol poisoning]. / Osobennosti strukturnykh i funktsional'nykh izmenenii setchatki i zritel'nogo nerva u patsientov s toksicheskoi opticheskoi neiropatiei na fone otravleniya metanolom.

PURPOSE: To identify the specifics of structural and functional changes in patients with toxic optical neuropathy caused by acute methanol poisoning. MATERIAL AND METHODS: One female patient with toxic optic neuropathy (TON), 2 male patients with partial optic atrophy caused by methanol poisoning, and 1 male patient with methanol intoxication after ethanol containing alcohol use were examined with kinetic perimetry and optical coherence tomography. RESULTS: Patients with TON caused by acute methanol poisoning were observed to have decreasing visual acuity to the extent of complete blindness. OCT follow-up studies revealed thinning of the retinal nerve fiber layer (RNFL) as well as formation of microcysts in the inner retinal layers, destruction of ellipsoid zone and outer segments of photoreceptors. The patient with methanol intoxication after use of ethanol containing alcohol had retained his visual functions; he was found to have microcysts and RNFL thinning during the first few months after the intoxication, but they were within normal range of OCT parameters. CONCLUSION: Patients with TON caused by acute methanol poisoning are common to have optic atrophy with either residual visual functions or complete blindness as well as microcysts formation, structural changes and destruction of the ellipsoid zone and outer segments of photoreceptors. In patient with methanol intoxication after use of ethanol, which is known to be an antidote, complete visual recovery was observed, although some microcystic changes and ganglion cells layer thinning were noted.

Inorganic Polyphosphate and Physiological Properties of Saccharomyces cerevisiae Yeast Overexpressing Ppn2.

The effect of the yeast endopolyphosphatase Ppn2 overproduction on the metabolism of inorganic polyphosphates in Saccharomyces cerevisiae yeast was studied. Expression of the PPN2 gene under control of the strong constitutive promoter of glyceraldehyde 3-phosphate dehydrogenase gene (PKG1) led to a significant increase in the endopolyphosphatase activity stimulated by cobalt/zinc ions. This activity was present in both soluble and membrane subcellular fractions; it was higher toward long-chain polyphosphates and could be stimulated by ADP. The content of short-chain polyphosphates in the cells of the overexpressing strain was ~2.5 times higher compared to the parent strain. The cells overexpressing Ppn2 were more resistant to peroxide and alkali. The role of short-chain polyphosphates in the adaptation to these stress factors is discussed.

[Mitochondrial biogenesis in hereditary optic neuropathies]. / Mitokhondrial'nyi biogenez pri nasledstvennykh opticheskikh neiropatiiakh.

The article offers a review of mitochondrial biogenesis in hereditary optic neuropathies. It covers the mechanisms of mitochondrial biogenesis, factors affecting it and tools for mitochondrial turnover assessment.

[Hydrogen Sulfide Donor NaHS Protects Mesenchymal Stem and Melanoma Cells from the Negative Effects of Infrared Laser Irradiation].

We have established earlier that 835-nm infrared laser irradiation results in a dose-dependent growth inhibition of human mesenchymal stem and melanoma cells and is able to induce cell death. In this work we have demonstrated that hydrogen sulfide donor NaHS is able to protect both cell types from the negative action of laser irradiation and the magnitude of protection depends on NaHS concentration. The mechanism of cell protection by NaHS is primarily attributable to its effects on intracellular processes occurring after irradiation, since the protective effect does not depend on whether NaHS is added before or after irradiation. Moreover, NaHS is able to exert its protective effect even when added 6 hours post irradiation.

[Effect of Myocardial Reperfusion on Ischemic Mitral Regurgitation in Patients with Acute Myocardial Infarction].

BACKGROUND: During the restoration of blood flow in the ischemic area of the myocardium, viable cardiomyocytes are damaged over a few minutes of tissue reperfusion (reperfusion myocardial damage). It is known that ischemic mitral regurgitation (IMR) develops in 11-19 % of patients who have undergoing percutaneous coronary intervention (PCI) in symptomatic coronary heart disease (CHD). To present day, the influence of myocardial reperfusion on IMR in patients with acute myocardial infarction (AMI) is not fully understood. OBJECTIVE: To study dynamics of quantitative indicators of IMR in patients with AMI after myocardial reperfusion. MATERIALS AND METHODS: We included in this study 68 patients with AMI and IMR aged 36-79 years, who were hospitalized in cardiac intensive care unit of the Moscow S. S. Yudin hospital in 2016. All patients before and on the 7th day after PCI underwent doppler echocardiography study with calculation of quantitative parameters of IMR and index of local contractility (ILC) of the left ventricle (LV). RESULTS: Three groups of patients were identified based on the analysis of the dynamics of quantitative parameters of IMR after myocardial reperfusion: group 1 - patients who had a decrease in IMR (n=23, 33.8 %), group 2 - patients with increase of IMR (n=28, 41.1 %), group 3 - patients with unchanged IMR (n=17, 25.1 %). The study of systolicLV function in all patients before PCI revealed moderately decreased ejection fraction (EF) (mean 49.05±1.19 %). On day 7 after myocardial reperfusion in group 2 we detected significant increases of end-diastolic volume (EDV), end-systolic volume (ESV), and the volume of the left atrium (LA), while in groups 1 and 3 these indexes remained unchanged. LV ILC did not differ between three groups, both at admission and on day 7 after reperfusion (p>0.05). There was no correlation between severity of IMR and ILC (correlation coefficient 0.24). CONCLUSION: Dynamics of quantitative parameters of IMR in 7 days after myocardial reperfusion in patients with AMI without endogenous and drug protection of the myocardium from reperfusion injury was multidirectional. IMR decreased in 33.8, increased in 41.1 and did not change in 25.1 % of patients. Systolic function and LV ILC underwent no significant dynamics.

Reversible and irreversible alterations of the optical thickness of PQ/PMMA volume recording media samples. Part 2: mathematical modeling.

A theoretical study of phenanthrenequinone-doped polymethyl methacrylate (PQ/PMMA) samples parameter changes during irradiation is presented. The research has been carried out on the basis of the experimental study (Part 1, [Appl. Opt.56, 7351 (2017)APOPAI0003-693510.1364/AO.56.007351]) and a mathematical model that describes space-time reversible and irreversible light-induced changes of the PQ/PMMA sample parameters during exposition. Based on the numerical modeling results and the use of analytical dependencies, a number of practically important characteristics of the PQ/PMMA sample-exposure process are considered: conversion-induction period of phenanthrenequinone into a photoproduct, Δtind; bleaching time of a sample, tbl; and thermal nonlocality of photoresponse, δlT. It is shown that the values Δtind and tbl are on the order of tens and hundreds of seconds, respectively, and can be comparable to the exposure time. It is established that temperature increase leads to δlT value change by hundreds of nanometers and can cause considerable deformation of the interference structure under recording. The sample heating during exposition is considered in detail, and an algorithm for estimation of the maximum temperature increase to be used in experiments is proposed. Recommendations are made for the reduction of negative influence of sample heating on the parameters of recorded holograms.

[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.

Reversible and irreversible alterations of the optical thickness of PQ/PMMA volume recording media samples. Part I: Experiment.

Experimental research into changes of the optical thickness of phenanthrenequinone-doped polymethyl methacrylate samples in the process of irradiation by a 473 nm laser is presented. It was demonstrated that heating-induced reversible changes lead to a decrease in the optical thickness. The temperature coefficient of the relative changes of the optical thickness was measured to be -1.40×10-5 К-1, which matches the data published by other authors. It is also established that the irreversible changes induced by the photochemical transformation lead to an increase in the optical thickness outside of the absorption band of the samples (λ>530 nm), where the relative change of which at λ=532 nm is +3.7×10-5. It was demonstrated that the reversible and irreversible changes do not compensate for each other in the process of sample exposure.