[Computer morphometry of peripheral blood lymphocytes in elderly patients with chronic pyelonephritis.]

The aim of the study was to investigate the peculiarities of morphometric parameters of peripheral blood lymphocytes in chronic pyelonephritis in elderly patients in comparison with young and middle-aged patients. A total of 81 patients with chronic pyelonephritis in the exacerbation phase were examined. All patients were divided into three age groups according to WHO recommendations: the 1st - 42patients of young age (18-44 years); the 2nd - 17 patients of middle age (45-59 years); the 3rd - 22 elderly patients (60-74 years). Computer morphometry of lymphocytes was performed in all examined patients. In elderly patients with chronic pyelonephritis the size and сytoplasmic-nuclear ratio of lymphocytes increase. This indicates the preservation of lymphocyte defense responses at this age. In male patients with chronic pyelonephritis in the 1st and 2nd age groups the size of lymphocytes increases, and in female patients - decreases. The сytoplasmic-nuclear ratio increases in males of these age groups, while it remains unchanged or decreases in females. Indirect indications of reduced immunity in young and middle-aged women with chronic inflammation in the kidneys have been obtained.

Antibiotic prescribing practices and perceptions on antimicrobial resistance among healthcare practitioners in Russia.

OBJECTIVES: Antimicrobial resistance (AMR) is a growing global health threat. The misuse of antibiotics is the main factor contributing to the development of AMR. Healthcare practitioners (HCPs) play a crucial role in the use of antibiotics. There are limited data available on antibiotic prescribing patterns among physicians in Russia. The aim of this study was to explore antibiotic prescribing practices and perceptions of AMR among HCPs in the Russian Federation. STUDY DESIGN: A cross-sectional, multi-centre study was used. METHODS: A survey using an online questionnaire was conducted among HCPs. A qualitative study was conducted before the questionnaire was developed. The online questionnaire was distributed via email addresses obtained from the Consilium Medicum database, a specialised educational resource for healthcare professionals in Russia. RESULTS: In total, 746 HCPs from 74 regions of the Russian Federation were included in the study. Physicians who participated in this study did not frequently prescribe antibiotic drugs: 40.6% of participants recommended antibiotics less than five times per week. Gynaecologists, paediatricians, family doctors, and surgeons were the least likely study participants to prescribe antibiotics, whereas clinical pharmacologists, otolaryngologists, urologists, and infectious disease specialists prescribed antibiotics more often. Amoxicillin and amoxicillin/clavulanic acid were the most frequently prescribed antimicrobials. The majority of HCPs in Russia who took part in this survey reported relying on national guidelines for information on antibiotic prescribing. Only 67.8% of study participants perceived AMR as a challenge for their practice. CONCLUSIONS: Health authorities should regularly provide up-to-date reliable information on AMR in the region. Antimicrobial stewardship programmes are important for specialised medical professionals, such as urologists, gynaecologists, and otolaryngologists, since they are responsible for prescribing second-line antibiotics, which carries with it a greater responsibility.

[Modern Approaches to Protein Engineering to Create Enzymes with New Catalytic Properties].

Adenine-DNA-glycosylase MutY is a monofunctional enzyme and catalyzes hydrolysis of N-glycosidic bonds with adenine residues located opposite 8-oxonuanine residues in DNA. Rational design was carried out to construct mutant enzyme forms with altered catalytic activity. Structures of the MutY mutants were calculated by molecular dynamics (MD). Their analysis showed that some of the MutY mutants may have AP lyase activity in addition to hydrolyzing the N-glycosidic bond, as is the case with bifunctional DNA glycosylases. MutY mutants with the A120K or S124K substitution were obtained by site-directed mutagenesis, and their catalytic activities were determined. The S120K substitution was shown to confer additional AP lyase activity, while the A124K substitution completely inactivated the enzyme.

[DNA Probes for Analysis of the Activity of Key Enzymes of the Base Excision DNA Repair Pathway in Human Cells].

The important role of DNA damage in the occurrence of various diseases, including cancer, has led to study of the mechanisms of genetic information stability, that have been carried out since the discovery of DNA repair systems. The question of the relationship between the accumulation of DNA damage, disorders in DNA repair pathways, and increased risk of disease development is still relevant. Over the past few years, significant efforts have been made to develop methods for analyzing the activity of DNA repair enzymes in human cells. In this work, we developed fluorescent DNA probes that allow us to determine the activity of key enzymes of base excision DNA repair in cell extracts, namely the DNA glycosylases UNG2, SMUG1, MBD4, TDG, AAG, NEIL1, NTHL1, and OGG1 and the AP endonuclease APE1. The sensitivity of DNA probes was determined on pure enzyme preparations. Determination of the activity of repair enzymes in cell extracts of the human ovarian tumor lines TOV112, 79, OVCAR3, MESOV, SCOV3, and TOV21 revealed significant variability in the level of enzyme activity in these cell lines. These results may become a test system platform for analyzing the activity of the base excision DNA repair system in the human body.

[Medical and social assessment of the quality of life of a family with a child suffering from food allergy].

Food allergy (FA) is a health problem that adversely affect the quality of life of children and their family members. The purpose of the study was to assess the quality of life in families with children affected FA. Material and methods. A cross-sectional study was conducted in a group of 75 children with a confirmed FA (at the age of Me 4.9 years [1.3; 7.1]). One of the caregivers of the child was asked to complete the Russian version of a specialized questionnaire «The Food hypersensitivity famiLy ImPact, FLIP¼ for assessing the life quality of families with children affected FA. Results. Diet organization is the main concern affecting quality of life, while the daily life of the family and the emotional sphere are less impacted. Age, type of food allergens and clinical manifestations do not significantly contribute the life quality indicators. Hypersensitivity to several food is statistically associated with changes in everyday life and emotions. Non-compliance with the diet is associated with a lower impact of FA on quality of life. 56% of respondents worried about the nutritional value of child's diet and 49.3% of caregivers reported that a child's FA significantly impacted grocery shopping behaviors (reading labels, etc.). At the same time, 73.3% noted that child's FA does not affect the diet of other family members. Also, 33.3% of the parents experienced anxiety due to child's FA and 38.7% are worried that FA might stay persistent. 30.7% of respondents are afraid of accidental consuming of allergenic products. Conclusion. The acquired results indicate the importance of quality of life assessment for understanding the social aspects of FA. Strategies to improve the quality of life include the development of informational and educational programs both for parents and patients. In order to estimate impact of FA to life quality from the patient's perspective further development of questionnaires adapted for children and adolescents is necessary.

[The present-day epidemiology: challenges of public health and possibilities to settle them: the publications review].

Actually, the epidemiology is a dynamically developing medical science located at the intersection of social and biological branches of knowledge and bio-informatics. The new sources of data, the new methods create unique opportunities for epidemiologist. The number of epidemiological studies carrying out at the junction of several adjacent disciplines is increasing that requires harmonious interaction of specialists of different branches of medical knowledge. The change of the structure of global mortality towards chronic non-communicable diseases significantly affected the vector of epidemiological studies. Many interventional epidemiological projects are targeted to evaluation of effectiveness of new methods of prevention of cardiovascular, metabolic and oncological diseases. However, in recent years, the fight against unremembered infections affecting about 1 billion of people and taking away lives of 0.5 million people annually gained new importance. The current COVID-19 pandemic also affected epidemiology of communicable and chronic non-communicable diseases. Great attention is also currently attended to studying influence of social, economic and environmental factors on human health. The increase of average life expectancy of population contributes to development of epidemiology of the elderly. The new projects are initiated in the field of pharmacoepidemiology targeted to studying effectiveness of medications. The review of national and foreign publications considering current trends and achievements in the field of epidemiology. The reference retrieval engines such as PubMed, Google Scholar, CyberLeninka were used. The current directions of epidemiological research are analyzed. The challenges and development prospects of development of modern epidemiology are highlighted.

[Spontaneous otoliquorrhea, complicated by recurrent secondary meningitis, in a 6-year-old child with an abnormality of the inner ear]. / Spontannaya otolikvoreya, oslozhnennaya retsidiviruyushchim vtorichnym meningitom, u rebenka 6 let s anomaliei razvitiya vnutrennego ukha.

Congenital anomalies in the inner ear structures development are one of the reasons for unilateral hearing loss in children. Unilateral hearing loss is predominantly congenital, thus children with this pathology are initially deprived of the ability to hear with both ears, which leads to the formation of a specific «individual hearing norm¼. Due to this, children do not complain of hearing loss, and unsuspecting parents can only guess why their child is poorly studying and lagging behind his peers. Unfortunately, in some situations the detection of malformations of inner ear structures occurs only after the development of complications, namely spontaneous otoliquorrea, leading to bacterial meningitis, and exactly episodes of meningitis (sometimes recurrent) become the cause for examination of patient and diagnosis of this pathology. We present one of this clinical observations.

[Clinical and radiological classification of otosclerosis]. / Kliniko-rentgenologicheskaya klassifikatsiya otoskleroza.

The article presents various classifications of forms of otosclerosis (OS), which change with the development of diagnostic methods. At the same time, according to the literature, a unified OS classification has not yet been adopted. All existing classifications are imperfect to some extent. The classification of clinical forms of OS according to TPA data makes it possible to determine the indications for surgical treatment and to suggest its possible effect, but not the localization of OS foci. X-ray classifications of localization of OS foci indicate their diversity, distribution, and do not always correlate with the type of hearing loss. At the same time, modern diagnostics of OS should be based on audiological data, localization of foci and their density according to the results of X-ray methods of examination. Based on the examination and treatment of 1532 patients with various forms of OS, a modern clinical and radiological classification of the disease is proposed, based precisely on these provisions. This classification, in our opinion, will improve the quality of diagnosis of various forms of OS, will allow to differentiate the tactics of treating patients with this disease to stabilize hearing loss, indications for surgical treatment, suggest its effectiveness with a reduction in the risk of surgical failures and possible further rehabilitation of the patient.

[Methods of gut microbiota correction for treatment and prevention of food allergy: a review of current research].

Food allergy (FA) is an actual problem in pediatric practice. The gut microbiota plays a crucial role in food sensitization development, since the maturation of immune system occurs under the influence of intestinal microorganisms. Immunoregulatory activity of gut microbiota is associated with the increase of IgA production and promotion of the barrier function of intestinal epithelium. Gut microbiota influence the activity of T-regulatory cells, as well. Violation of gut biocenosis, which occurs under the influence of various factors (artificial feeding, past diseases, the use of antibiotics, etc.), can lead to a shift in the balance of the immune system towards the increase of Th2-profile cytokines and the subsequent formation of hypersensitivity to food allergens. In this regard, the correction of the gut microbiome is a promising method of FA control, due to the ability of intestinal bacteria influence the production of T-regulatory cells and thus suppress allergy immune response. The aim of the review is to analyze experimental and clinical studies exploring effectiveness of methods modifying intestinal microbiota in order to treat and prevent FA. Material and methods. The analysis of the literature in eLIBRARY, MedLine and PubMed databases was carried out. Results. The analysis revealed the lack of rigorous evidence that pre-, pro- and synbiotics significantly increase the effectiveness of standard therapy of FA. However, the use of bifidobacteria, lactobacilli, lactic acid bacteria, in combination with the basic therapy of FA has general positive effect on the clinical outcome, especially in case of gastrointestinal symptoms. Also, the results of some studies indicate the effectiveness of synbiotics (Bifidobacterium breve M-16V, Lactobacillus rhamnosus GG in combination with oligosaccharides) for the prevention of FA in patients at risk of developing allergic diseases in the long-term period. Conclusion. At present, fecal microbiota transplantation is promising method for FA treatment. Polysaccharides fermented by the microflora, are also actively studied. Experimental studies and clinical trials are required to obtain substantiated conclusions about feasibility of these methods for treatment and prevention of FA.

[Initial stages of DNA Base Excision Repair in Nucleosomes].

In mammalian cells, base excision repair (BER) is the main pathway responsible for the correction of a variety of chemically modified DNA bases. DNA packaging in chromatin affects the accessibility of damaged sites to the enzymes involved in repair processes. This review presents data concerning the enzymes involved in BER. Within the nucleosome core particle (NCP), the accessibility of damaged DNA to enzymes is hindered by the presence of a histone octamer. This means that the removal of DNA lesions largely depends on their rotational and translational positioning in the NCP, as well as on the specific features of each enzyme.

[Mutational and Kinetic Analysis of APE1 Endoribonuclease Activity].

Human apurinic/apyrimidinic endonuclease 1 (APE1) participates in the DNA repair system. It is believed that the main biological function of APE1 is Mg^(2+)-dependent hydrolysis of AP-sites in DNA. On the base of structural data, kinetic studies, and mutation analysis, the key stages of APE1 interaction with damaged DNA were established. It has been shown recently that APE1 can act as an endoribonuclease that catalyzes mRNA hydrolysis at certain pyrimidine-purine sites and thus controls the level of certain transcripts. In addition, the presence of Mg^(2+) ions was shown to be not required for the endoribonuclease activity of APE1, in contrast to the AP-endonuclease activity. This indicates differences in mechanisms of APE1 catalysis on RNA and DNA substrates, but the reasons for these differences remain unclear. Here, the analysis of endoribonuclease hydrolysis of model RNA substrates with wild type APE1 enzyme and its mutant forms Y171F, R177F, R181A, D210N, N212A, T268D, M270A, and D308A, was performed. It was shown that mutation of Asn212, Asp210, and Tyr171 residues leads to the decrease of AP-endonuclease activity while endoribonuclease activity is retained. Also, T268D and M270A APE1 mutants lose specificity to pyrimidine-purine sequences. R177F and R181A did not show a significant decrease in enzyme activity, whereas D308A demonstrated a decrease of endoribonuclease activity.

[Comparative Analysis of the Activity of the Polymorphic Variants of Human Uracil-DNA-Glycosylases SMUG1 and MBD4].

The human N-glycosylases SMUG1 and MBD4 catalyze the removal of uracil residues from DNA resulting from cytosine deamination or replication errors. For polymorphic variants of SMUG1 (G90C, P240H, N244S, N248Y) and the MBD4^(cat) catalytic domain (S470L, G507S, R512W, H557D), the structures of enzyme-substrate complexes were obtained by molecular dynamic simulation. It was experimentally found that the SNP variants of SMUG1, N244S and N248Y, had increased catalytic activity compared to the wild-type enzyme, probably due to the acceleration of the dissociation of the enzyme-product complex and an increase in the enzyme turnover rate. All other SNP variants of SMUG1 (G90C, P240H) and MBD4^(cat), in which amino acid substitutions disrupted the substrate binding region and/or active site, had significantly lower catalytic activity than the wild-type enzymes.

[Tendoplasty and its effectiveness in the rehabilitation of hearing loss in patients with otosclerosis]. / Tendoplastika i ee effektivnost' pri khirurgicheskoi reabilitatsii patsientov s tugoukhost'yu, obuslovlennoi otosklerozom.

The article briefly presents the physiology of the stapes muscle tendon (SMT), and features in its defeat. Its length was studied using high-resolution multispiral computed tomography of the temporal bones. We also studied the possibility of its restoration using the author's method of tendoplasty using metallized stapes prostheses. Tendoplasty with stapedoplasty was performed in 74 patients with otosclerosis (OS), and 48 patients had stapedoplasty without tendoplasty. As a result of research, the average length of the SMT was 2.38±0.02 mm, which explains the need to use a 3 mm long venous autograft for tendoplasty. The author's method of tendoplasty for stapedoplasty allows restoring the acoustic reflex in 54.1% of OS patients using artificial stapes prostheses. The preservation of the vascular bed in the thickness of the restored tendon can improve the trophy of the long incus process and reduce the risk of its dystrophic changes in the postoperative period. In addition, this fact confirms the importance of the stapes muscle in the acoustic reflex.

Role of Arg243 and His239 Residues in the Recognition of Damaged Nucleotides by Human Uracil-DNA Glycosylase SMUG1.

Human uracil-DNA glycosylase SMUG1 removes uracil residues and some other noncanonical or damaged bases from DNA. Despite the functional importance of this enzyme, its X-ray structure is still unavailable. Previously, we performed homology modeling of human SMUG1 structure and suggested the roles of some amino acid residues in the recognition of damaged nucleotides and their removal from DNA. In this study, we investigated the kinetics of conformational transitions in the protein and in various DNA substrates during enzymatic catalysis using the stopped-flow method based on changes in the fluorescence intensity of enzyme's tryptophan residues and 2-aminopurine in DNA or fluorescence resonance energy transfer (FRET) between fluorophores in DNA. The kinetic mechanism of interactions between reaction intermediates was identified, and kinetic parameters of the intermediate formation and dissociation were calculated. The obtained data help in elucidating the functions of His239 and Arg243 residues in the recognition and removal of damaged nucleotides by SMUG1.

The Role of ERBB2/HER2 Tyrosine Kinase Receptor in the Regulation of Cell Death.

HER2 (Human Epidermal Growth Factor Receptor 2), also known as ERBB2, CD340, and Neu protooncogene, is a member of the epidermal growth factor receptor (EGRF) family. Members of the ERBB family, including HER2, activate molecular cascades that stimulate proliferation and migration of cancer cells, as well as their resistance to the anticancer therapy. These proteins are often overexpressed and/or mutated in various cancer types and represent promising targets for the anti-cancer therapy. Currently, anti-HER2 drugs have been approved for the treatment of several types of solid tumors. HER2-specific therapy includes monoclonal antibodies and low-molecular weight inhibitors of tyrosine kinase receptors, such as lapatinib, neratinib, and pyrotinib. In addition to the activation of molecular pathways responsible for cell proliferation and survival under stress conditions, HER2 directly regulates programmed cell death. Here, we review the studies focused on the involvement of HER2 in various signaling pathways and its role in the regulation of apoptosis.

An Assay for the Activity of Base Excision Repair Enzymes in Cellular Extracts Using Fluorescent DNA Probes.

Damaged DNA bases are removed by the base excision repair (BER) mechanism. This enzymatic process begins with the action of one of DNA glycosylases, which recognize damaged DNA bases and remove them by hydrolyzing N-glycosidic bonds with the formation of apurinic/apyrimidinic (AP) sites. Apurinic/apyrimidinic endonuclease 1 (APE1) hydrolyzes the phosphodiester bond on the 5'-side of the AP site with generation of the single-strand DNA break. A decrease in the functional activity of BER enzymes is associated with the increased risk of cardiovascular, neurodegenerative, and oncological diseases. In this work, we developed a fluorescence method for measuring the activity of key human DNA glycosylases and AP endonuclease in cell extracts. The efficacy of fluorescent DNA probes was tested using purified enzymes; the most efficient probes were tested in the enzymatic activity assays in the extracts of A549, MCF7, HeLa, WT-7, HEK293T, and HKC8 cells. The activity of enzymes responsible for the repair of AP sites and removal of uracil and 5,6-dihydrouracil residues was higher in cancer cell lines as compared to the normal HKC8 human kidney cell line.

[Efficiency of RNA Hydrolysis by Binase from Bacillus pumilus: The Impact of Substrate Structure, Metal Ions, and Low Molecular Weight Nucleotide Compounds].

Binase is an extracellular guanyl-preferring ribonuclease from Bacillus pumilus. The main biological function of binase is RNA degradation with the formation of guanosine-2',3'-cyclic phosphate and its subsequent hydrolysis to 3'-phosphate. Extracellular RNases are believed to be key agents that affect the functional activity of the body, as they directly interact with epithelial and immune cells. The biological effects of the enzyme may consist of both direct RNA degradation, and the accumulation of 2',3'-cGMP in the human body. In this work, we have performed a comparative analysis of the cleavage efficiency of model RNA substrates, i.e., short hairpin structures that contain guanosine at various positions. It has been shown that the hydrolysis efficiency of the model RNA substrates depends on the position of guanosine. We have also demonstrated the influence of various divalent metal ions and low molecular weight nucleotide compounds on the binase-catalyzed endoribonucleolytic reaction.

[Exudative otitis media as a manifestation of spontaneous otoliquorrhea]. / Ekssudativnyi srednii otit kak proyavlenie spontannoi otolikvorei.

Spontaneous otoliquorrhea (SOL) often mimics the picture of exudative otitis media (EOM), which leads to delayed diagnosis of the underlying disease. PURPOSE OF STUDY: Is to evaluate causes, clinical features and diagnostic algorithm for patients with SOL. PATIENTS AND RESEARCH METHODS: From 2007 to 2018, 33 patients with SOL underwent examination and treatment in the Department of Ear Microsurgery of the Institute. At the preoperative stage, all patients underwent a complete examination, including examination of ENT organs, anthropometric, biochemical, audiological, ultrasound and radiological tests, which made it possible to make the correct diagnosis. RESULTS: SOL was more likely to occur in women over 50 who are obese (69.7%, stage II-III). The disease onset in 51.6% of patients was preceded by conditions accompanied by a short-term or prolonged increase in intracranial pressure. SOL was manifested by the clinical picture of EOM in 72.7% of cases, only in 45.5% of cases was accompanied by release from the ear and nose, was often intermittent and complicated by meningitis in 12.1% of patients. Difficulties in diagnosing the disease are caused by clinical manifestations of exudative or acute otitis media in the absence of a causative factor, which led to the verification of SOL from 1 to 4 years in 81.9% of patients who received long-term treatment for other ENT diseases. CONCLUSION: The master factors in the diagnosis of SOL are otomicroscopy and endoscopy of the nasopharynx, Halo test and screening determination of glucose level in the obtained discharge, as well as high-resolution CT of the temporal bone, which allows to localize the cerebrospinal fluid fistula and to determine the size of the defect.

Opisthorchis felineus negatively associates with skin test reactivity in Russia-EuroPrevall-International Cooperation study.

BACKGROUND: Most studies on the relationship between helminth infections and atopic disorders have been conducted in (sub)tropical developing countries where exposure to multiple parasites and lifestyle can confound the relationship. We aimed to study the relationship between infection with the fish-borne helminth Opishorchis felineus and specific IgE, skin prick testing, and atopic symptoms in Western Siberia, with lifestyle and hygiene standards of a developed country. METHODS: Schoolchildren aged 7-11 years were sampled from one urban and two rural regions. Skin prick tests (SPT) and specific IgE (sIgE) against food and aeroallergens were measured, and data on allergic symptoms and on demographic and socioeconomic factors were collected by questionnaire. Diagnosis of opisthorchiasis was based on PCR performed on stool samples. RESULTS: Of the 732 children included, 34.9% had opisthorchiasis. The sensitization to any allergen when estimated by positive SPT was 12.8%, while much higher, 24.0%, when measured by sIgE. Atopic symptoms in the past year (flexural eczema and/or rhinoconjunctivitis) were reported in 12.4% of the children. SPT was positively related to flexural eczema and rhinoconjunctivitis, but not to wheezing. Opisthorchiasis showed association with lower SPT response, as well as borderline association with low IgE reactivity to any allergen. However, the effect of opisthorchiasis on SPT response was not mediated by IgE, suggesting that opisthorchiasis influences SPT response through another mechanism. Opisthorchiasis also showed borderline association with lower atopic symptoms. CONCLUSIONS: There is a negative association between a chronic helminth infection and skin prick test reactivity even in a developed country.

[The fistula of the round window of the cochlea]. / Fistula okna ulitki.

This article presents the data on the frequency, diagnostics, and variants of the surgical treatment of the fistula of the round window of the cochlea. A case of this pathology is reported with the special emphasis placed on the approaches to the diagnostics and surgical management of this condition.