[Express-diagnosis of the diseases of the eye and its appendages by scanning electron microscopy with supravital staining]. / Skaniruyushchaya elektronnaya mikroskopiya s supravital'nym kontrastirovaniem v ekspress-diagnostike zabolevanii glaza i pridatochnogo apparata.

This review describes the history of development of a new line of chemical reagents that prompts to significantly reevaluate the application of scanning electron microscopy (SEM) in medical and biological studies, particularly in ophthalmology; considers the establishing of SEM as an analytical method; covers the problems in its application associated with the needs of clinical medicine and the complexities of biological sample preparation for electron microscopy. The article also presents in chronological order the technical solutions associated with creating a unique line of reagents for supravital staining. The multitude of technical solutions allows considering SEM as a method of express diagnostics. The review discusses examples of practical application of these methods for solving certain cases in clinical ophthalmology. The niche of SEM is considered among other methods of clinical diagnostics, as well as its future development involving the use of artificial intelligence.

Influence of surface viscosities on the electrodeformation of a prolate viscous drop.

Contaminants and other agents are often present at the interface between two fluids, giving rise to rheological properties such as surface shear and dilatational viscosities. The dynamics of viscous drops with interfacial viscosities has attracted greater interest in recent years, due to the influence of surface rheology on deformation and the surrounding flows. We investigate the effects of shear and dilatational viscosities on the electro-deformation of a viscous drop using the Taylor-Melcher leaky dielectric model. We use a large deformation analysis to derive an ordinary differential equation for the drop shape. Our model elucidates the contributions of each force to the overall deformation of the drop and reveals a rich range of dynamic behaviors that show the effects of surface viscosities and their dependence on rheological and electrical properties of the system. We also examine the physical mechanisms underlying the observed behaviors by analyzing the surface dilatation and surface deformation.

Realization of a push-me-pull-you swimmer at low Reynolds numbers.

Locomotion at low Reynolds numbers encounters stringent physical constraints due to the dominance of viscous over inertial forces. A variety of swimming microorganisms have demonstrated diverse strategies to generate self-propulsion in the absence of inertia. In particular, ameboid and euglenoid movements exploit shape deformations of the cell body for locomotion. Inspired by these biological organisms, the 'push-me-pull-you' (PMPY) swimmer (Avron J Eet al2005New J. Phys.7234) represents an elegant artificial swimmer that can escape from the constraints of the scallop theorem and generate self-propulsion in highly viscous fluid environments. In this work, we present the first experimental realization of the PMPY swimmer, which consists of a pair of expandable spheres connected by an extensible link. We designed and constructed robotic PMPY swimmers and characterized their propulsion performance in highly viscous silicone oil in dynamically similar, macroscopic experiments. The proof-of-concept demonstrates the feasibility and robustness of the PMPY mechanism as a viable locomotion strategy at low Reynolds numbers.

[A case report of a high bifurcation of the median nerve].

We present a clinical case of injury to the flexor tendons of the fingers and wrist and to the median and ulnar nerves at the forearm level. An atypical high bifurcation of the median nerve at the forearm level was revealed during surgery.

[The simulator for mastering of tendon suture technique].

The article describes the tendon and simulator model for mastering of tendon suture technique. As a tendon model, the authors suggest to use segments of silicone rods, which remain unclaimed after a two-stage tendon reconstruction. Diameter, shape, elasticity of silicone prostheses satisfies to similar parameters of the fingers hand man tendons. The plastic board with holes is using as a support for fixation of the tendon model. The proposed device is simpler and more available in comparison with the known analogues. The effectiveness of the original model and simulator tested in practice at training young surgeons.

[Apparatus for external fixation of the hand].

The authors offered the apparatus for external fixation of the hand. A medical plastic is used for making the support of an improvised apparatus. The pins "sealed" in plastic and fixed bone fragments. The proposed apparatus has a number of advantages in comparison with analogous devices and could be useful for surgeons who provide emergency care for the patients with hand injuries.

Mitochondrial cytochrome redox states and respiration in acute pulmonary oxygen sensing.

Hypoxic pulmonary vasoconstriction (HPV) is an essential mechanism to optimise lung gas exchange. We aimed to decipher the proposed oxygen sensing mechanism of mitochondria in HPV. Cytochrome redox state was assessed by remission spectrophotometry in intact lungs and isolated pulmonary artery smooth muscle cells (PASMC). Mitochondrial respiration was quantified by high-resolution respirometry. Alterations were compared with HPV and hypoxia-induced functional and molecular readouts on the cellular level. Aortic and renal arterial smooth muscle cells (ASMC and RASMC, respectively) served as controls. The hypoxia-induced decrease of mitochondrial respiration paralleled HPV in isolated lungs. In PASMC, reduction of respiration and mitochondrial cytochrome c and aa3 (complex IV), but not of cytochrome b (complex III) matched an increase in matrix superoxide levels as well as mitochondrial membrane hyperpolarisation with subsequent cytosolic calcium increase. In contrast to PASMC, RASMC displayed a lower decrease in respiration and no rise in superoxide, membrane potential or intracellular calcium. Pharmacological inhibition of mitochondria revealed analogous kinetics of cytochrome redox state and strength of HPV. Our data suggest inhibition of complex IV as an essential step in mitochondrial oxygen sensing of HPV. Concomitantly, increased superoxide release from complex III and mitochondrial membrane hyperpolarisation may initiate the cytosolic calcium increase underlying HPV.

The effects of hypoxia on the cells of the pulmonary vasculature.

Pulmonary hypertension is associated with remodelling of pulmonary vessels. Chronic hypoxia is a common cause of pulmonary hypertension and pulmonary vascular remodelling. Vascular remodelling is characterised largely by fibroblast, smooth muscle and endothelial cell proliferation, which results in lumen obliteration. Chronic hypoxia elicits expression of mitogens, growth factors and cytokines by fibroblasts and endothelial cells, and also the suppression of endothelial nitric oxide synthase. Although hypoxic pulmonary vascular remodelling is associated with medial hypertrophy, many in vitro studies have found that hypoxia does not lead to a direct increase in smooth muscle cell proliferation. This paradox is not well understood and this review aims to examine the various reasons why this might be so. The present authors reviewed data from in vitro studies and also considered whether hypoxia could act on adjacent cells such as fibroblasts and endothelial cells to trigger smooth muscle cell proliferation. It is possible that hypoxia is sensed by fibroblasts, endothelial cells, or both, and relayed to adjacent pulmonary artery smooth muscle cells by intercellular signalling, causing proliferation. The present article reviews the data from in vitro studies of hypoxia on the three cellular components of the pulmonary vascular wall, namely endothelial cells, smooth muscle cells and fibroblasts.

[Statistically mapping modeling of the spread of rifampicin-resistant M. tuberculosis strains in different regions of the Kyrghyz Republic].

Mapping modeling of the distribution of rifampicin-resistant tuberculosis was made in different regions of the Kyrghyz Republic. The results of determination of rifampicin resistance in Mycobacterium tuberculosis (MBT) by the biochip test were used to examine 904 MBT DNA samples taken when examining the patients living in different regions of the Kyrghyz Republic: Bishkek (n = 323), the Chui (n = 185), Issyk-Kul (n = 68), Naryn (n = 75), Talas (n = 47), Osh (n = 65), Dzhalal-Abad (n = 90), and Batken (n = 51) Regions. Comparison of the distribution of drug-resistant forms of tuberculosis by different regions revealed that rifampicin-resistant MBT strains were more frequently encountered in the densely populated regions of the republic - Bishkek and the Chui Region. Rifampicin resistance in MBT was caused by mutations in codons 531, 526, 522, 516, 511, 513, 512, and 513 of the rpoB gene. At the same time, there was a predominant selection of MBT with mutations in codons 531, 526, 516, and 511 in the republic. The spectrum of mutant MBT strains occurring in some regions varied. The broadest spectrum of genetic variability was observed in Bishkek and the Chui Region. Thus, Bishkek and the Chui Region are the hot points of concentration of mutant rifampicin-resistant MBT strains.

[Use of biological microchips in the determination of drug-resistance of Mycobacterium tuberculosis to rifampicin].

The present-day problems in tuberculosis control are associated with a difficulty in detecting Mycobacterium tuberculosis (MBT) in due time and in determining its drug sensitivity by conventional microbiological assays. The determination of the drug sensitivity of MBT takes much time from 2 weeks to 3 months, which fails to initiate and perform specific therapy timely. Molecular genetic techniques, including biochip analysis, yield results in 24-48 hours, which solves the problem of choosing and initiating adequate antibacterial therapy in the shortest possible time after tuberculosis is diagnosed. To assess the situation associated with the prevalence of rifampicin-resistant tuberculosis, by using the biochip analysis, the authors have examined 501 patients with tuberculosis who live in the Kyrghyz Republic. Drug resistance has been found in 40.3% of the examinees. At the same time, their primary and secondary drug resistance is 25.7 and 61.8%, respectively. In tuberculosis patients living in Kyrghyzstan, rifampicin resistance of MBT is more frequently due to mutations in 531 (59.2%), 526 (20.8%), and 516 (8.0%) codons in the rpoB gene.