Репозиторий Университета

© 2018 Osipov, Machneva, Buravlev and Vladimirov. The biological roles of heme and nonheme nitrosyl complexes in physiological and pathophysiological conditions as metabolic key players are considered in this study. Two main physiological functions of protein nitrosyl complexes are discussed-(1) a depot and potential source of free nitric oxide (NO) and (2) a controller of crucial metabolic processes. The first function is realized through the photolysis of nitrosyl complexes (of hemoglobin, cytochrome c, or mitochondrial iron-sulfur proteins). This reaction produces free NO and subsequent events are due to the NO physiological functions. The second function is implemented by the possibility of NO to bind heme and nonheme proteins and produce corresponding nitrosyl complexes. Enzyme nitrosyl complex formation usually results in the inhibition (or enhancement in the case of guanylate cyclase) of its enzymatic activity. Photolysis of protein nitrosyl complexes, in this case, will restore the original enzymatic activity. Thus, cytochrome c acquires peroxidase activity in the presence of anionic phospholipids, and this phenomenon can be assumed as a key step in the programmed cell death. Addition of NO induces the formation of cytochrome c nitrosyl complexes, inhibits its peroxidase activity, and hinders apoptotic reactions. In this case, photolysis of cytochrome c nitrosyl complexes will reactivate cytochrome c peroxidase activity and speed up apoptosis. Control of mitochondrial respiration by NO by formation or photolytic decay of iron-sulfur protein nitrosyl complexes is an effective instrument to modulate mitochondrial metabolism. These questions are under discussion in this study.

©2018 Osipov, Machneva, Buravlev and Vladimirov. The biological roles of heme and nonheme nitrosyl complexes in physiological and pathophysiological conditions as metabolic key players are considered in this study. Two main physiological functions of protein nitrosyl complexes are discussed-(1) a depot and potential source of free nitric oxide (NO) and (2) a controller of crucial metabolic processes. The first function is realized through the photolysis of nitrosyl complexes (of hemoglobin, cytochrome c, or mitochondrial iron-sulfur proteins). This reaction produces free NO and subsequent events are due to the NO physiological functions. The second function is implemented by the possibility of NO to bind heme and nonheme proteins and produce corresponding nitrosyl complexes. Enzyme nitrosyl complex formation usually results in the inhibition (or enhancement in the case of guanylate cyclase) of its enzymatic activity. Photolysis of protein nitrosyl complexes, in this case, will restore the original enzymatic activity. Thus, cytochrome c acquires peroxidase activity in the presence of anionic phospholipids, and this phenomenon can be assumed as a key step in the programmed cell death. Addition of NO induces the formation of cytochrome c nitrosyl complexes, inhibits its peroxidase activity, and hinders apoptotic reactions. In this case, photolysis of cytochrome c nitrosyl complexes will reactivate cytochrome c peroxidase activity and speed up apoptosis. Control of mitochondrial respiration by NO by formation or photolytic decay of iron-sulfur protein nitrosyl complexes is an effective instrument to modulate mitochondrial metabolism. These questions are under discussion in this study.

© 2018 Dynasty Publishing House. All rights reserved. The objective. To determine age-related specificities of microcirculation-tissue systems in children from varied age groups. Patients and methods. We analysed the results of examining healthy children aged 3 to 17 years and also young people under 25 years of age with the use of nail-fold capillaroscopy (n = 65) and laser Doppler flowmetry(n = 50). Results. According to capillaroscopy, no significant differences in microcirculation parameters in children of varied age have been obtained, but as has been found, diameters of all parts of capillaries and the width of perivascular spaces increased to some extent with children's age. Also, the density of first-line capillaries increased with age in the examined patients. The average microcirculation values obtained by LDF did not show any statistically significant difference between children from the age group 7 to 13 years and children aged 13 to 18 years. Microcirculation parameters are not dependent on a patient's age. The average values of PI may be used as reference parameters for diagnosing microcirculation impairments in children with varied pathologies. Conclusion. The capillaroscopy values and basal microcirculation values that we have obtained may be used in practically healthy children for comparison with such values in children with varied pathologies, which might be helpful in diagnosing various diseases and disorders at early stages and exercising control over treatment with selection of individual pharmacotherapy.

© 2018, University of Kragujevac, Faculty of Science. All rights reserved. The aim of this study is to conduct several non-invasive methods for assessing the level of circulatory disturbance, elasticity and aging of skin in patients of different age groups in order to expand the diagnostic capabilities and evaluate the effectiveness of current research in aesthetic medicine. Clinical and instrumental exploration of 160 women aged 17 to 75 years with varying degrees of involutional skin changes was carried out. To objectify the assessment of skin condition, in all group of patients modern instrumental methods were used, such as: elastometry, ultrasound examination of the skin, laser Doppler flowmetry, transcutaneous oxygen tension. Concurrent implementation of several non-invasive methods for assessing the level of circulatory disturbance, elasticity and aging of the skin, allowed us to find new possibilities for studying the functional state of the skin. These methods extend the possibilities of ultrasonic research methods used today in aesthetic cosmetology. The obtained comparative data of elastometry, ultrasonography, laser Doppler flowmetry and transcutaneous oximetry in patients of different age groups showed the presence of elasticity and structure defect, skin thickness and subcutaneous fat, as well as microcirculation changes since 25 years and marked changes after 40 years.

© 2018, Media Sfera. All rights reserved. Condition of the ocular surface greatly depends on functional integrity of corneal nerve fibers. Improving the methods used to study corneal nerve fibers allows their condition to be timely evaluated and adequately interpreted. The article reviews the structure, function, chemical composition of corneal nerve fibers, specifics of their innervation, as well as application of modern methods of their evaluation in diagnostics of various pathological conditions.

The article reviews the literature on methods of evaluating the morphological and functional state of the eyelids in chronic blepharitis. Development of methods continues together with further research on the etiology and pathogenesis of the disease.

© ABC-press Publishing House. All rights reserved. Objectives to enhance the morphological diagnostic complex in order to predict postoperative outcomes in a more accurate way and to optimize patients with non-muscular invasive bladder cancer treatment. Materials and methods. The study included 34 patients from 25 to 71 years old underwent laser en-block resection, the most of them were males - 28. In 9 cases multiple carcinomas (2 or more) were found. Huge tumors (2 cm or more in one dimension) were resected in 6 patients. Results. The major part of tumors removed (n = 22) histologically appeared to be papillary urothelial carcinomas with low grade of malignancy and PUNLMP; in 6 cases G2 was verified, one tumor with high malignancy potention - G3. In 3 patients intramuscular invasion was found (invasive carcinoma T2) excluding them from the study. Discussion. Laser en-block resection of non-muscle-invasive bladder cancer appears to be the most optimal approach in operative treatment that provides representative histological material. For correct morphological estimate we recommend either to expand the resection zone to 1 cm which allows to remove circular resection margin or to take extra pinch biopsy from tumor crater (vertical margin). In 3 patients from our study positive circular margin was revealed histologically whereas foci of perineural and perivascular invasion were found in one case. A new subgrading of stage T1 depending on intramuscular invasion depth was suggested whereas the main criteria is the muscularis mucosae involvement. Conclusion. Morphological estimate of circular resection margin provides an ability to predict postoperative outcomes and correct the treatment in one or another way. Subgrading for T1-stage tumors is recommended for following correct postoperative prognosis and possibility of tumor recurrence.

© 2018 SPIE. A reliable connection of dissected biological tissues is a popular problem in modern surgery. In the last decade, two methods of biological tissues connection using laser radiation have been actively developed: laser-assisted vascular repair (LAVR) and anastomosis (LAVA). These methods make it possible to obtain a weld impenetrable for blood and other biological fluids immediately after the welding. A solder is applied to a welding area. The main characteristic of the weld at LAVA is the tensile strength. A weld should be flexible enough to withstand repeated cycles of alternation of diastolic and systolic pressures. Single-walled and multi-walled carbon nanotubes (SWCNTs and MWCNTs respectively) are used to increase the weld tensile strength. They form a spatial bovine serum albumin (BSA)- nanocarbon scaffold under an action of laser radiation. It in real time varies the power of laser radiation (in the range 0.2- 5 W), which is necessary to stabilize the welding temperature (∼57C). In the present work new compositions of laser solder are proposed and the scheme of the installation for LAVR are offered. The proposed solder is based on an aqueous dispersion of BSA, MWCNTs and SWCNTs, ICG and collagen. The using of the chromophore ICG is due to its absorption maximum corresponding to the wavelength of the diode laser used (∼ 810 nm). The tensile strength was 0.8±0.3 MPa.

© 2018, Peter the Great St. Petersburg Polytechnic University. The interaction of laser radiation with aqueous dispersion of only bovine serum albumin (BSA) 25 wt. %, only bovine collagen (BC) 2 wt. %, and 25 wt. % BSA with single-walled carbon nanotubes (SWCNTs) 0.3 wt. % and 2 wt. % BC with 0.3 wt.% SWCNT was studied. The beam was absorbed mainly by nanotubes, that confirmed by the small value of the nonlinear absorption coefficients for aqueous dispersed media with BSA 6 cm GW-1, as well as dispersion with BK 4 cm GW-1 and the large values of coefficients for these media with addition of SWCNTs, respectively 350 cm GW-1 and 70 cm GW-1. Determination of nonlinear optical parameters was obtained by the method of fixed sample location. Knowledge of the values of these parameters allowed calculating theoretical curve of Z-scan with open aperture what made possible to compare with the experimental data.

© 2018 ABC-press Publishing House. All rights reserved. Background. The high recurrence rate after conventional transurethral resection (cTUR) for bladder cancer (BC) requires search for more effective methods of surgical treatment. Objective: to evaluate the feasibility, safety, and efficacy of cTUR versus thulium laser en bloc resection of bladder tumors using new fiber laser "Urolaz". Materials and methods. 129 patients, who underwent surgical treatment for BC between 2015-2017 in urological department of I.M. Sechenov First Moscow State Medical University were included in the study. The cTUR were performed for 58 patients, 71 patients underwent thulium laser en bloc resection of bladder tumors. Results. The presence of detrusor muscle in specimen was 58.62 % in cTUR group and 91.55 % in thulium laser en bloc resection group respectively. Obturator nerve reflex, bladder perforation, and bleeding in thulium laser en bloc resection group were absent, therefore immediate instillation of chemotherapy was made in all these cases. Recurrence rate after 12 and 18 months after surgery in the group of en bloc resection was statistically lower compared to the cTUR group. Conclusion. The results, obtained in our study shows that thulium en bloc resection using thulium fiber laser "Urolaz" is feasible, effective and safe procedure for patients with BC. Thulium en bloc resection has a number of advantages over the cTUR: Absence of obturator nerve reflex, high quality of specimen for pathological examination (presence of detrusor muscle in specimen was 91.55 %) and low recurrence rate.

© 2018 Authors. The present work presents a description of various cutting devices with an emphasis on skin surgery for the optimal choice of instruments in plastic surgery. Physical principles of work with a description of the biological role of an ultrasonic scalpel, various laser cutting devices, electrosurgical instruments, including radiofrequency electrosurgery, are described. Studies of recent years, including systematic reviews and meta-analyzes, are devoted to comparative analysis of various cutting and coagulating devices among themselves and in comparison with the mechanical metal scalpel.

© 2018, Media Sfera. All rights reserved. The article describes a newly developed and tested diffractive optical element (DOE) that converts non-uniform radiation of the laser output into a homogeneous ring. The Gerchberg-Saxton algorithm is shown to be well suited for achieving annular intensity distribution. Testing this ring transducer on threshold-plasticity cornea demonstrated the reversibility of axisymmetric changes in the cornea. Atomic-Force microscopy of the area of maximum stresses in the corneal periphery showed no significant changes in the structure of the cornea when irradiated in the selected mode. Measurement of Young’s modulus of the corneal surface areas after their irradiation also revealed no changes in the elastic properties, while examination of the corneal structure demonstrated the absence of significant structural changes in irradiated samples compared with intact ones.

© 2018 SPIE. The conductivity of layers (thickness ∼ 0.5-20 μm) of composite nanomaterials consisting of bovine serum albumin (BSA) with single-walled carbon nanotubes (SWCNTs) has been studied. The BSA/SWCNT composite nanomaterial was prepared according to a route map, some steps of which are: the preparation of an aqueous dispersion based on BSA and SWCNT; preparation of substrates; deposition of BSA/SWCNT dispersion on substrates; application of water paste from SWCNT on substrates; irradiation of layers by lasers when they were in a liquid state; drying of samples; carrying out electrical and temperature measurements. Half of the layer was covered with a light-tight hollow box and the other half of the layer was laser irradiated. The laser irradiation of the layer was carried out for about 20 sec, at which time the layers completely became dry, while the other half of the layer remained in liquid. Conductivity was increased (70 ÷ 650) % by laser irradiation of the layers when they were in the liquid state. Maximum values of specific conductivity for BSA/SWCNT-1 S/m layers, and for layers SWCNT - 70 kS/m. The investigated electrically conductive layers of 99 wt.% BSA/0.3 wt.% SWCNT are promising for medical practice.

© 2019, Privolzhsky Research Medical University. All rights reserved. The aim of the study was to assess the efficiency of the method for registration of video fluorescence of 5-ALA-induced protoporphyrin IX in stomach and esophagus diseases, to adapt it for clinical conditions, i.e. for conducting differential diagnosis and detecting precancer conditions, and to formulate recommendations on the best photosensitizer doses and time of application in order to make the diagnostic procedure for these diseases more accurate. Materials and Methods. Registration of fluorescence for diagnostic purposes was performed on 57 patients with gastropathology (mainly with stomach cancer) with the help of single-channel (n=50) and dual-channel (n=7) laser video fluorescence registration systems. The study was performed using 5-aminolevulinic acid (5-ALA) (Alasens). 39 endoscopic, 18 intraoperative/laparoscopic investigations, and 7 studies on the macropreparation have been performed. Results. When both systems were used, no fluorescence was registered in cases of stomach ulcer, chronic gastritis, massive tumor necrosis and blood admixture in the stomach as well as in the patient with subcompensated stenosis and a stented output section of the stomach without serous membrane invasion and low 5-ALA concentration. In all other cases, a distinct fluorescence was recorded, the data of which may be used for establishing exact diagnosis and choosing further treatment tactics. Conclusion. Laser video fluorescence technique is a promising method for differential diagnosing and definition of the tumor extension process in the stomach and esophagus which can be used as an express method in diagnostically complex cases.

© 2018 Carta, Mariani, Sambiagio, Chuchueva, Lecis, Gerosa and Puxeddu. The present study analyzed the results of the endoscopic approach to T1, T2 and selected T3 supraglottic carcinoma with the aim of reviewing functional and oncologic outcomes after different types of endoscopic supraglottic laryngectomies. This is a retrospective clinical study of 42 consecutive patients (mean age of 61.8 years, 33 males, 9 females) treated by the senior author for supraglottic squamous cell carcinoma with a transoral CO2 laser approach and reviewed from November 2010 to September 2017. Surgical procedures were classified according to the European Laryngological Society. In addition to the standardized transoral supraglottic laryngectomies, we introduced a modified type IVb by sparing the inferior third of the arytenoid if not directly involved in the tumor. Swallowing was evaluated with the Swallowing Performance Status Scale reported by the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology. Survival probabilities were estimated using Kaplan-Meier curves. Two type I, 2 type IIa, 2 type IIb, 3 type IIIa, 12 type IIIb, 13 type IVa, 3 type modified IVb, and 5 type IVb supraglottic laryngectomies were performed. Twenty-one patients (50%) underwent primary neck dissection. The pathologic TNM classification according to the 8th edition of the American Joint Committee on Cancer system was as follows: 9 pT1cN0, 2 pT1N0, 1 pT1N1, 7 pT2cN0, 1 rypT2cN0, 9 pT2N0, 4 pT2N1, 2 ypT2N1, 2 pT3cN0, 2 rypT3cN0, 1 pT3N1, and 2 pT3N2b. Mean follow-up was 3.4 years (range of 9 months to 6 years). According to the Kaplan-Meier analysis, 5-year disease-specific survival, local-relapse-free survival, nodal-relapse-free survival, overall laryngeal preservation and overall survival of patients without previous head and neck radiotherapy/open surgery were 100%, 95.2%, 87.8%, 100%, and 64.6%, respectively. Patients who underwent type I, IIa, and IIb resections (n = 6) started oral feeding the day after surgery, patients who underwent type III-IVb modified resections (n = 31) started oral feeding 3-4 days after surgery, and patients who underwent standard type 4b resections (n = 5) started oral feeding 7 days after surgery. Threemonths after surgery, patients without a clinical history of previous head and neck radiotherapy/open surgery who underwent type III, IVa, and modified IVb resections showed significantly better swallowing compared to patients who underwent standard type IVb resection: grade 4-6 impairment of swallowing in 8 and 66.7% of cases, respectively (p = 0.006072); patients with a clinical history of previous head and neck radiotherapy/open surgery who underwent type III, IVa, and modified IVb resections showed not statistically significant better swallowing compared to patients who underwent standard type IVb resection: grade 4-6 impairment of swallowing at 3 months in 16.7% and 50% of cases, respectively (p = 0.23568). Transoral CO2 laser supraglottic laryngectomy is an oncologic sound alternative to traditional open neck surgery and chemo-radiotherapy. Recovery of swallowing is significantly worsened after total resection of the arytenoid. Modified type IVb procedure leaving intact, when possible, the inferior third of the arytenoid and consequently the glottic competence, improves functional outcome.

© 2018 SPIE. The technology of cell 3D scaffolds laser fabrication is developed. 3D scaffolds are designed to repair osteochondral defects, which are poorly restored during the organism's life. The technology involves the use of an installation, the laser beam of which moves along a liquid nanomaterial and evaporates it layer by layer. Liquid nanomaterial consists of the water-protein (collagen, albumin) suspension with carbon nanoparticles (single-walled carbon nanotubes). During laser irradiation, the temperature in the region of nanotubes defects increases and nanotubes are combined into the scaffold. The main component of installation is a continuous laser operating at wavelengh of 810 nm. The laser beam moves along 3 coordinates, which makes it possible to obtain samples of the required geometric shape. The internal and surface structure of the samples at the micro- A nd nanoscale levels were studied using the X-ray microtomography and scanning electron microscopy. In vitro studies of cell growth during 48 and 72 hours demonstrated the ability of cell 3D scaffolds to support the proliferation of osteoblasts and chondroblasts. Using fluorescence and atomic force microscopy, it was found that the growth and development of cells on a sample with a larger concentration of nanotubes occurred faster compared to samples with a smaller concentration of nanotubes.

© COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only. In this paper, we demonstrate instruments for laser radiation delivery based on sapphire capillary needles. Such sapphire irradiators (introducers) can be used for various medical applications, such as photodynamic therapy, laser hyperthermia, laser interstitial thermal therapy, and ablation of tumors of various organs. Unique properties of sapphire allow for effective redistribution of the heat, generated in biological tissues during their exposure to laser radiation. This leads to homogeneous distribution of the laser irradiation around the needle, and lower possibility of formation of the overheating focuses, as well as the following non-transparent thrombi.

© COPYRIGHT SPIE. The paper considers physical processes and mechanisms of laser reparation of spine cartilage, presents results of investigations aimed to optimize laser settings and to develop feedback control system for laser reconstruction of spine discs. Possible mechanisms of laser-induced regeneration include: (1) Space and temporary modulated laser beam induces non-homogeneous and pulse repetitive thermal expansion and stress in the irradiated zone of cartilage. Mechanical effect due to controllable thermal expansion of the tissue and micro and nano gas bubbles formation in the course of the moderate (up to 50 °C) heating of the NP activate biological cells (chondrocytes) and promote cartilage regeneration. (2) Non-destructive laser radiation leads to the formation of nano and micro-pores in cartilage matrix in the in the immediate vicinity of chondrocytes. That promotes water permeability and increases the feeding of biological cells. Results provide the scientific and engineering basis for the novel low-invasive laser procedures to be used in neurosurgery and orthopedics for the treatment cartilages of spine. The technology and equipment for laser reconstruction of spine discs have been tested first on animals, and then in a clinical trial. Since 2001 the laser reconstruction of intervertebral discs have been performed (i) for more than 3,200 patients with chronic symptoms of low back or neck pain who failed to improve with non-operative care; and (ii) for 1100 patients underwent hernia removal surgery. Substantial relief of back pain was obtained in 92.5% of patients treated who returned to their daily activities. LRD allowed also to decrease secondary surgeries more than three times. Optical fiber technique based on light scattering measurements have been used to promote safety and efficacy of the laser procedures.

© COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only. We have developed cryo-applicators based on the sapphire shaped crystals fabricated using the edge-defined film-fed growth (EFG) and noncapillary shaping (NCS) techniques. Due to the unique physical properties of sapphire: i.e. high thermal, mechanical, and chemical strength, impressive thermal conductivity and optical transparency, these cryo-applicators yield combination of the tissue cryo-destruction with its exposure to laser radiation for controlling the thermal regimes of cryosurgery, and with the optical diagnosis of tissue freezing. We have applied the proposed sapphire cryo-applicators for the destruction of tissues in vitro. The observed results highlight the prospectives of the sapphire cryo-applicators in cryosurgery.

© 2017 Astro Ltd. A two-photon laser femtosecond crosslinking process at the wavelength of 525 nm was studied in a human donor cornea in the presence of riboflavin using two-photon optical microscopy and nanoindentation. It was shown that such an approach results in efficient crosslinking of the corneal collagen and a significant (three-fold) increase in the Young's modulus of the corneal structure. Application of a femtosecond laser with the wavelength of 525 nm allows a drastic enhancement of efficiency in the presence of riboflavin on human corneas and a 50-fold reduction of the laser treatment duration in comparison with the use of a femtosecond laser with the wavelength of 760 nm. We relate this effect to a significant growth in the coefficient of two-photon absorption due to the laser wavelength falling within the edge of the photoinitiator (riboflavin) absorption band. Our studies on a donor human cornea demonstrate the good potential for the clinical application of a femtosecond laser with the wavelength of 525 nm for increasing the cornea rigidity using the two-photon laser femtosecond crosslinking technique.