Daria V. Eliseeva

Obesity is a global health problem whose incidence is steadily increasing. Modern lifestyles, characterized by changing dietary preferences and low levels of physical activity, are key factors in the development of obesity and overweight. Obesity increases the risk of numerous gastrointestinal (GI) diseases, such as gastroesophageal reflux disease, inflammatory bowel disease, functional digestive disorders, and others. The pathogenesis of these conditions includes chronic low-grade inflammation, increased intestinal barrier permeability, and changes in the intestinal microflora. The purpose of this article is to describe and systematize high-calorie diets and to study the morphological and pathophysiological mechanisms by which these diets influence the gastrointestinal tract. This review examines the main types of diets used to model obesity in laboratory animals: high-fat, high-carbohydrate, with a choice of fats or carbohydrates, combined (“cafeteria diet”, “Western diet”), and models of psychogenic overeating. Histological features of the gastrointestinal tract wall of obese rats are represented by changes in the mucosa (a decrease in the number of PAS-positive goblet cells) and the lamina propria (an increase in the number of neutrophils, lymphocytes, macrophages, and collagen fibers). In addition, increased concentrations of IL-1β, IL-6, IL-8, TNF and monocyte chemotactic protein (MCP-1), and malondialdehyde (MDA) were detected in the colon wall. Obesity and excess body weight have been shown to impact structural components of the nervous system (hyperactivation of enteric ganglia, disruption of the autonomic nervous system, etc.), leading to impaired gastrointestinal motility. Experimental studies demonstrate that high-calorie diets alter the histological characteristics and motility of the gastrointestinal tract in laboratory animals, causing structural damage and disruption of innervation of the digestive organs. This indicates the need for further research to identify the mechanisms underlying the development of obesity complications and develop effective preventive measures.

The impact of the new coronavirus COVID-19 infection on the course of pregnancy, maternal and child health is largely unclear and controversial. The presented literature review analyzes changes in the immune, cardiovascular, and endocrine systems in women in physiological pregnancy. The peculiarities of the course of infection caused by SARS-CoV-2 virus in pregnancy, depending on the virus variant, are presented, the issues of infection pathways into immune and non-immune cells, including placental cells, as well as the issues of transplacental transfer of the virus – the key moment of infection of the embryo or fetus, on which the outcome of pregnancy also largely depends, are considered. Promising approaches to COVID-19 therapy are presented: use of inhibitors of transmembrane serine protease 2 (TMPRSS2), furin, angiotensin-converting enzyme (ACE2) and RNA-dependent RNA polymerase, amnion epithelial cells and their exosomes. At the same time, the potential use of mesenchymal stem cells in patients with severe COVID-19 pneumonia is reviewed. Difficulties and questions regarding the use of the above therapeutic methods in pregnant women are highlighted. Aspects of the use of surfactant preparations in newborns at risk of new coronavirus infection are considered.

Obesity and diseases of the gastrointestinal tract are widespread among the children and have common developmental mechanisms. The article provides a literature review on the relationships between certain pathological conditions of the digestive system (gastroesophageal reflux disease, gastritis, functional intestinal disorders, Crohn’s disease, diverticular disease) in children with overweight and obesity. Excess body weight and obesity can become risk factors for the development of gastrointestinal pathology. The data available in modern literature on changes in the composition of the intestinal and stomach microbiocenosis with increasing body weight are summarized (changes in enterotype, increase in the Firmicutеs/Bacteroides ratio, increase in the number of bacteria Methanobrevibacter, Escherichia coli, Lactobacillus rhamnosus, Lactobacillus delbrueckii and Lactobacillus reuteri). The strains of bacteria that contribute to the anorexigenic effect are considered: Lactobacillus gasseri, some strains of Bifidobacterium, Saccharomyces, Streptococcus and Enterococcus. The pathogenetic aspects of obesity and overweight caused by microbiota are presented: activation of lipid synthesis, breakdown of polysaccharides, absorption of mono- and disaccharides, development of metabolic endotoxemia, etc. Features of the functioning of the autonomic nervous system in obesity in children are presented, indicating the predominance of the hypersympathicotonic variant of autonomic reactivity.

ОЦЕНКА ЭФФЕКТИВНОСТИ И БЕЗОПАСНОСТИ ПЕРОРАЛЬНЫХ АНТИКОАГУЛЯНТОВ У ПАЦИЕНТОВ С ФИБРИЛЛЯЦИЕЙ ПРЕДСЕРДИЙ В ПРОСПЕКТИВНОМ НАБЛЮДЕНИИ