This review article analyzes and summarizes the history of the replenishment of the family Flaviviridae with new members over the last several decades on the example of the youngest genera of this family - Hepacivirus and Pegivirus .

It all started in 1966 when surgeon George Barker, who had hepatitis, had blood serum taken in containing an unknown virus. This virus was named GBV , by patient initials. Samples of the serum were frozen. A nucleic acid recognized as corresponding to the genomes of 2 separate virus species was isolated from the tested material in 1995. These viruses were named GBV-A and GBV-B . By this time, the hepatitis C virus had already been discovered, which was assigned to the Flaviviridae family, where a separate, third genus of Hepacivirus was allocated for it.

In 2010, a more distantly related virus (named GBV-D ) was found in bats (Indian flying fox - lat. Pteropus giganteus ). GBV-B , which causes acute hepatitis in experimentally infected tamarines, became the second species in the genus Hepacivirus to company with hepatitis C virus. The remaining GB viruses based on phylogenetic relation-ships, genome organization, and pathogenetic properties were proposed in 2011 to be classified as members of the fourth genus in the Flaviviridae family. This genus was named Pegivirus (pe - persistence, g - GB).

11 species of viruses have now been identified in the genus Pegivirus . They are indicated by letters in the order of the Latin alphabet - from Pegivirus A to Pegivirus K. And 14 species of viruses have now been identified in the genus Hepacivirus . So the story of the investigation, which began in 1966 with the discovery of the previously unknown GBV virus, has so far concluded with the discovery of two new genera of the family Flaviviridae. Numerous members of these two genera infect and also persist among a wide range of species belonging to different orders of the mammalian class, including Homo Sapiens .

Objective : to determine the features of the infection caused by Сhlamydia trachomatis, Chlamydia pneumoniae, Mycoplasma hominis, Mycoplasma pneumoniae in children with bronchitis and pneumonia and to improve the methodology of molecular genetic diagnostics of the respiratory infections caused by chlamydia and mycoplasma.

Material and methods. 272 children aged 0-17 diagnosed with bronchitis, pneumonia, were examined for the presence of chlamydia-mycoplasma respiratory tract infection by Realtime PCR.

Results. The study has revealed a high proportion of chlamydia and mycoplasma associations (23 %) with the predominance of Mycoplasma pneumoniae - 73 %. The identification of the associations Сhlamydia trachomatis , Сhlamydia pneumoniae , Mycoplasma hominis , Mycoplasma pneumoniae in bronchitis and pneumonia in the children was optimized by the use of Realtime PCR with Chlamydiaceae- and Mycoplasma-specific primers.

Conclusion . To confirm the etiological role of chlamydia and mycoplasma in the development of respiratory pathology in children, it is promising to apply the specific and highly sensitive method of molecular genetic diagnostics - Real-time PCR.

Objective: to present the features of the course and outcomes of HIV infection diagnosed at the stage of pronounced immunosuppression.

Material and methods. Based on the primary CD4 + T-lymphocytes count, 492 patients living with HIV were divided into 2 groups: group 1 - 220 patients (CD4 + TL less than or equal to 350 cells/μl), group 2 - 272 patients (CD4 + TL more than 350 cells/µl). The statistical analysis was performed using the package «Statisticа» v.10.

Results. Among the patients of the first group there were more men than in the second group: 136 (61.8 %) and 125 (46 %), p < 0.001, respectively; more patients in HIV clinical stages 3 and 4 - 52.7 % and 27.6 %, p < 0.05; more ART patients: 208 (94.5 %) and 148 (54.4 %) p < 0.001, respectively. The levels of T-helpers and IRI (immunoregulatory index) in the patients of group 2 in the follow-up dynamics remained significantly higher compared with those of the patients of group 1. The incidence of tuberculosis was higher in group 1: 33 (15 %) and 15 (5.5 %), respectively, p < 0.05. In the first group, 23 (10.5 %) patients died, in the second - 9 (3.3 %), p < 0.003.

Conclusion. HIV-infection at the stage of pronounced immunosuppression was diagnosed in 220 patients - 44.7 % (95 % CI: 40.4-49.1) of the cases. Severe immunosuppression in the primarily diagnosed patients was associated with the presence of HIV clinical stages 3 and 4 (OR - 2.9; 95 % CI: 2.0-4.3), higher incidence rates of tuberculosis (OR - 3.02; 95 % CI: 1.6-5.7) and fatal outcomes (OR - 3.4; 95 % CI: 1.5-7.5), a slower increase in T-helpers and IRI counts.

Objective: to analyze the mortality structure of patients with liver cirrhosis over 2015-2018 in Gomel.

Material and methods. A retrospective cohort analysis of 130 findings of postmortem autopsy of patients with liver cirrhosis has been performed (data of the departments of Gomel Regional Pathology Bureau at Gomel Regional Infectious Clinical Hospital, Gomel City Clinical Hospital No. 3 and Gomel City Clinical Hospital No. 2, 2015-2018). The age and gender structure of the patients, etiology and cause of death were analyzed. The data were entered and analyzed in MS Excel, 2010.

Results. Most frequently, the patients with cirrhosis die at 50-59 and usually of hepatorenal syndrome (HRS), gastrointestinal bleeding, and acute posthemorrhagic anemia. Non-viral hepatitis as a cause of cirrhosis is more prevalent (61.5 %) than viral hepatitis, while the etiology for more than a third of the cirrhosis cases (38.5 %) is not determined. Most of the patients who died were of the working age (67.7 %) and mainly males (56.2 %). More than a third of the patients (38.5 %) had been dependent on alcohol, while only 11.5 % patients had been dia nosed with alcohol related cirrhosis.

Conclusion. Thus, liver cirrhosis is still a socially topical issue for young ablebodied people. There remains a tendency to underestimate the alcoholic etiology of cirrhosis, as well as the uncertainty of the etiology of a significant part of detected cirrhosis cases.

Objective: to study the clinical and morphological parallels in women with ischemic-cervical insufficiency (ICI) and to analyze the relationship between the development of intrauterine infection (IUI) of the fetus and the outcome of pregnancy.

Material and methods. Pregnant women (n = 88) with corrected pessaries of ICI (main group) were examined, in 32 of which pregnancy ended in premature birth and in term birth in 56 women. The control group consisted of 30 women with the physiological course of pregnancy. The course of pregnancy has been analyzed, the morphological features of the fetoplacental complex and the health status of the newborns have been studied.

Results. Regardless of the term of labor, the patients with ICI have an increased risk for IUI in the newborn by 36 times compared with the control group (p = 0.012), and inflammatory changes in the placenta are observed in 96.6 % of the cases (2р(F) < 0.0001). In spontaneous preterm birth associated with ICI, chorioamnionitis is observed 7.3 times more often (p = 0.0005) than in urgent birth and is related to premature rupture of the fetal membranes (r = 0.34; p = 0.023) and is 3 times more often accompanied by the development of IUI of the newborn (p = 0.017).

Conclusion: ICI is an important risk factor for intrauterine infection and the development of intrauterine infection of the newborn, which must be taken into account in the management of pregnancy in patients with ICI.

Objective: to determine the topography variants of the intrapelvic branches and anastomoses of the superior gluteal artery (SGA).

Material and methods. 29 cadavers of males (the intravital age ranged 27-75) and 11 cadavers of females (the in-travital age ranged 32-82) who had died of accidental causes not related to pelvic pathology were used as the research material. The preparation method, vascular injection method, and statistical method were applied to achieve the objective.

Results. It has been established that most often the formation of the intrapelvic branches and anastomoses of the SGA in the males and females is found in the proximal and middle thirds of the intrapelvic part of the artery, rarely - in its distal third. Stable hemostasis with a high probability can be achieved by excluding the proximal and middle thirds of the intrapelvic part of the SGA from the bloodstream by means of selective emboli or ligation.

Conclusion. The performed research has demonstrated the presence of a certain pattern of origination of the in-trapelvic branches and anastomoses of the SGA in the males and in females.

Objective: to identify the threshold values of FoxP3, CD56, PGRMC1, and Galectin-1 expression, to analyze the survival rate of female patients based on the obtained threshold values, to determine the statistical differences in groups depending on the presence/absence of radiotherapy.

Mаteriаl аnd methods. The group with radiotherapy (LT+) included 42 female patients, the group without radiotherapy (LT-) included 38. The ROC-analysis was performed to determine the threshold values. The analysis of the survival rate was performed using the logrank test. The groups were compared using the tables 2×2 (Fisher's twosided test), as well as the odds ratio (OR) was calculated. The differences were considered statistically significant at p < 0.05.

Results. The study of the Galectin-1 parenchymatous expression showed that statistically significant differences (p<0.0001) were revealed in the study of the relapsefree survival rate based on the obtained threshold value. Gamma ray therapy reduced the parenchymatous expression of Galectin-1 below the threshold value (OR = 0.490 95% CI 0.288-0.800). The analysis of the relapsefree survival rate on the basis of the obtained threshold value of the stromal expression of Galectin-1 revealed statistically significant differences (p = 0.0002). Gamma ray therapy reduced the stromal expression of Galectin-1 below the threshold value (OR = 0.289 95 % CI 0.112-0.742).

Conclusion. At a low relapsefree survival rate, a statistically significant increase above the threshold values of the parenchymatous (p < 0.0001) and stromal (p = 0.0002) Galectin-1 expression was observed most frequently.

Objective: to develop a model for prediction of spontaneous preterm birth (SPB) in women with ischemic-cervical insufficiency (ICI), identified and corrected with the pessary at the term 19-23/6 weeks of gestation.

Material and methods: 90 female patients with ischemic-cervical insufficiency, identified at 19-23/6 weeks of gestation (group 1 (n = 34) included women who gave preterm birth, group 2 (n = 56) were women who gave term birth), have been examined.

Results. The risk factors for SPB in the patients with ICI vary depending on the gestational age. The significant risk factors before the detection of ICI are: miscarriage; absence of term birth in the past history of multiparous women; violation of the vaginal microflora; transmitted urogenital infections. The risk factors for SPB at the time of the ICI verification: «sludge» in the lower pole of the fetal bladder; symptomatic variant of the course of ICI; low values of fluorescence protein in the cervical mucus. The risk factors for SPB after the performed correction of the ICI with the pessary are: high UCA values at 24 and 28 weeks of gestation; «sludge» in the amniotic fluid; tone of the lower segment of the uterus; reduced length of the closed part of the cervical cervix; pessary displacement. A dynamic prognosis will make it possible to identify the risk group for SPB at each stage of the management of preg-nant women, which will improve perinatal outcomes.

Conclusion. The proposed prognostic model (AUC = 0.935; Se = 76.5%; Sp = 96.4 %; 95% CI 0.86-0.98; p = 0.0001) has a high diagnostic efficiency of 90.3 %.

Objective: to study the nature of changes in the content of stable metabolites of nitric oxide (NOx) - nitrites and nitrates - in the blood of patients after coronary artery bypass graft (CABG) under the conditions of artificial circulation.

Material and methods. Depending on the level of [Hb] in the blood plasma, the patients with CABG surgery were divided into three groups: 1 - without IOH (Hb ≤ 0.1 g/l), n = 43, 2 - with low IOH (l IOH, Hb > 0.1 g/l and < 0.5 g/l, n = 42), 3 - with high IOH (hIOH, Hb ≥ 0.5 g/l, n = 38). The level of NOx was determined in the blood plasma of the patients.

Results. At the end of CABG, compared with the baseline, the patients revealed a decrease of NOx in the blood plasma and its increase - within 5-7 days after the surgery, to the utmost in the group with high IOH.

Conclusion. The change of NOx in the blood plasma depended on the severity of intraoperative hemolysis, which indicates the influence of the hemolysis products on the formation and utilization of nitric oxide.

Objective: to determine the relevance of ultrasound examination in diagnostics and assessment of the efficiency of cell therapy of experimental liver cirrhosis in rabbits.

Material and methods. The experiment was performed on white Californian rabbits (n = 45). Liver cirrhosis was modelled by means of subcutaneous injections of 50 % solution of carbon tetrachloride according to the scheme. Cell therapy was performed by means of a single intraportal injection of autologous mesenchymal stem cells (MSCs) at an amount of 5 × 106 cells per kg. During the experiment all the animals were performed the ultrasound examination of the abdominal cavity, as well as the morphological analysis of liver tissue samples.

Results. After 5 months of the liver cirrhosis modeling, the anteroposterior liver size and diameter of the portal vein in group 2 and group 3 were statistically larger than in group 1 (р < 0.001, Mann-Whitney test). There was no statistical difference in the anteroposterior liver size (р = 0.38) and diameter of the portal vein (р = 0.36) between group 2 and group 3. 1 month after the injection of autologous MSCs, the rabbits of group 3 detected some improvement of the echimage of the damaged liver, which was also reflected in a statistically significant decrease of the liver size by 8.2 % (р < 0.01, Wilcoxon test) and diameter of the portal vein by 23 % (р < 0.001) in comparison with the indicators before the injection of MSCs.

Conclusion. The ultrasound examination in the present study has proved itself to be a reliable method of intravital diagnostics of pathological changes in the conditions of a chronic experiment, and also has revealed a positive impact of cell therapy on liver cirrhosis in the rabbits. The obtained data were confirmed by the morphological methods of the analysis of the liver tissue samples of the animals during the experiment.

Objective: to study the morphological and morphometric features of bone tissue regeneration in the application of the native transplantation automixture during bone defects replacement in an experiment.

Material and methods. Male Wistar rats weighing 180-200 g. and aged 6-7 months were used. The bone defect was modeled using a 1.2 mm diameter cutter (experimental group). A similar defect of the middle third of the right tibia without filling the defect with bone tissue was formed in the animals of the control group. The animals were taken out of the experiment on the 3rd, 7th, 14th, and 30th days of the experiment (6 animals per each observation period). Histological sections 4-5 µm thick were stained with hematoxylin and eosin. The areas of necrosis, granulation tissue, bone trabecules (mm2) were determined.

Results. The laboratory animals in which the bone mixture had been transplanted revealed the growth of the area occupied by granulation tissue from the 3rd to 7th day of the experiment, and later its area had decreased by the 30th day compared to the control group, which was associated with faster transformation of granulation tissue into bone trabecules and formation of the foci of cerebrospinal hematopoiesis. On the 7th day of the experiment, the area of necrosis in the control group significantly exceeded the indicators of the experimental group (р ˂ 0.001). On the 14th day of the experiment necrosis in the animals of the experimental group was absent, while in the control one there were still some necrosis foci (0.541 ± 0.014 mm2). Starting from the 7th of the experiment, immature bone tissue began to form within the area of the bone tissue defect. At the same time, its area in the animals of the experimental group was statistically significantly larger on the 7th, 14th and 30th days in comparison with the control group during all observation terms (р ˂ 0.001).

Conclusion. The study has showed a higher rate of bone tissue formation in the bone defects in the experimental animals after autotransplantation of the bone mixture. The obtained results of bone autoplasty can be a theoretical basis for the development of the methods of the treatment of bone defects of any origin.

Objective: to assess the effect of chronic nonspecific stress on changes of the biochemical parameters of the blood serum in male Wistar rats.

Material and methods. The experimental study was performed on sexually mature male Wistar rats. The experimental group (n = 71) was exposed to chronic nonspecific stress according to the Ortiz method. The control group of the animals included intact animals (n = 31).

Results. The study has revealed changes in the biochemical composition of the blood serum of the rats: increased activity of ALT, LDH, ALP, urea, uric acid, and cholesterol, a decreased level of triglycerides.

Conclusion. These changes may indicate the alteration of the level of the intensity of the physiological processes of energy supply in the conditions of chronic stress.

Objective: to analyze the incidence of circulatory system diseases in the ablebodied population of Gomel over 2002-2017.

Material and methods. The information materials of the Gomel Regional Department of National Statistics, Ministry of Health of the Republic of Belarus, were used for the work. The statistical analysis of the study results was performed on a personal computer with the use of the program «Microsoft Excel», 2016.

Results. We have studied the features of deviations in the rates and structure of the incidence of circulatory system diseases recorded in the public health institutions. It has been established that over the past decade there has been an increase in the incidence rate of circulatory system diseases in the ablebodied population of Gomel.

Conclusion. The increased prevalence of circulatory system diseases calls forth the necessity to develop new organizational approaches to its prophylaxis.

Objective: to study the parameters of heart rate variability (HRV) and autonomic reactivity in response to an orthostatic test in young athletes of a school of Olympic Reserve.

Material and methods. The mathematical and spectral methods of the HRV analysis with the application of the 12-channel electrocardiograph «Poly-Spectrum-8» were used for the evaluation of vegetative tone, autonomic support, and autonomic reactivity.

Results. Statistically significant differences in the activity of the ANS were revealed in the examined athletes with aerobic and anaerobic types of physical exercise during their one-year training. In response to the orthostatic exposure in the athletes doing aerobic exercise, the sympathetic department of regulation is activated and centralization of the control over the heart rhythm is strengthened. In the young athletes involved in high-speed power sports, the vegetative reactivity is characterized by a higher degree of activation of humoral-metabolic regulation mechanisms than in the athletes specializing in endurance sports.

Conclusion. The study of the HRV parameters and analysis of autonomic reactivity in response to the orthostatic test in the young athletes of the school of Olympic Reserve during the preparatory and competitive periods make it possible to apply an individual approach to the training process taking into account the prevailing type of autonomic regulation and autonomic reactivity, which contributes to an elevated level of the functional readiness of the athletes for training activities.

The article presents a case of the successful management of pregnancy in a woman with large uterine fibroids and describes the main stages of the medical examination of the pregnant woman, planned hospitalizations, performed treatment, and features of the delivery.

Intrahepatic cholestasis of pregnanсу is the most common liver pathology in pregnant women. This disease has complex multifactorial pathogenesis, which is based on a genetic predisposition, insufficient amount of selenium in food and an incorrect reaction of a pregnant woman's body to a normal or elevated level of sex hormones and their metabolites. The main clinical manifestation is skin itching without skin rash. Intrahepatic cholestasis of pregnanсy leads to the development of pregnancy complications, such as preterm labour, often accompanied by meconium staining of amniotic fluid. In newborns, regardless of the gestational age, it contributes to the development of severe respiratory distress syndrome. These complications during pregnancy and the perinatal period are accompanied by high perinatal morbidity and mortality. This article describes three cases of pregnancy complicated by intrahepatic cholestasis, with early neonatal death of newborns. An indepth study and identification of the possible predictors of perinatal death of newborns from mothers with intrahepatic cholestasis of pregnancy will prevent negative outcomes in the future.

The article presents a clinical case of autoimmune polyglandular syndrome type II and analyzes the literary sources, clinical data, and results of laboratory tests.

Objective: to study the level of the hepatic tissue remodeling regulators MMP-9 and TIMP-1 in the blood of patients with the progression of chronic diffuse liver diseases.

Material and methods. The object of the study was 80 patients with chronic diffuse liver diseases (chronic hepatitis and cirrhosis). The concentration of MMP-9 and TIMP-1 in the blood of the patients was determined by enzymelinked immunosorbent assay (ELISA).

Results: As chronic diffuse liver diseases progressed, a statistically significant decrease in the level of MMP-9 in the blood of the patients was revealed, which was reflected in the decreased intensity of the extracellular matrix resorption processes and transformation of chronic hepatitis into liver cirrhosis. The activity of TIMP-1 which suppressed the fibrolytic effects of MMP-9, was statistically significantly higher in the viral etiology of liver cirrhosis, which probably led to more rapid progression of liver fibrosis associated with the presence of hepatitis C and В viruses.

The problems in teaching the methods of statistical data analysis in evidencebased medicine place high demands on their application. The rigor of the approach requires extensive knowledge in both the direct professional sphere and in areas of knowledge that go far beyond the limits of medicine. It is not enough to simply type groups for the study or calculate average values and draw some conclusions based on this. It is important to recruit groups and evaluate the statistical parameters of the obtained results correctly. Moreover, it is requisite to know the purpose of the research, formulate the appropriate hypotheses even before the beginning of the experiment [1] or data collection, and not to invent them during the analysis of an array of heterogeneous numbers and names when writing articles. The material of data processing presented at the level of schemes and algorithms in combination with the use of the appropriate programs is greatly simplified and, most importantly, streamlined. In this case, the subject of statistics is perceived not as something abstract, but as a complex component of the principles of evidencebased medicine, without detaching it from specialized training.

The involvement of specialists of the core subjects of the university sharing the examples of studies using the statistical processing and planning methods into the training will make it possible to improve orientation in a variety of the existing statistical methods of data processing, as well as to understand the importance and relevance of the use of statistics in medical research.

Objective: to develop a model of simulation training for students of medical colleges.

Material and methods. The normative documents and training programs of medical colleges, literature on the research problem have been analyzed, the methods of questioning, modeling have been applied.

Results. A model of simulation training includes the following stages: preclinical, clinical, and on thejob. Simulation training modeling at each stage allows to identify the following blocks: specialpurpose, problemspecific, contentspecific, and evaluative, having their own structure and content.

Conclusion . The proposed model of simulation training for the students streamlines the activities of all the subjects of the educational process at medical colleges, makes it possible to carry them out stepwise and to achieve a high level of professional knowledge and skills during the medical training, thereby ensuring successful adaptation of young professionals in health care institutions

The aim of the study was to determine the best options for the ultrasound (US) evaluation of the amount of visceral adipose tissue (VAT), taking into account the time spent on these investigations, availability of visualization of anatomical landmarks, reproducibility of methods and correlation of the measurement results with data obtained by computed tomography (CT), as well as the operational characteristics of the ROC analysis of the boundary values of the VAT amount in metabolic syndrome, arterial hypertension, coronary heart disease (CHD), and erectile dysfunction (ED).

The ultrasound measurement of VAT of various localization was performed in 337 patients aged 18-65. The selection of the optimal options for the ultrasound measurement of VAT was based on the qualimetric analysis.

For the ultrasound diagnosis of VAT, taking into account the integrative assessment of ranks, it seems optimal to measure the area of the lower part of perinephric adipose tissue, as well as the distance between the inner surface of the rectus abdominis muscle and the anterior or posterior wall of the aorta. Increased thickness of epicardial and pericardial VAT is typical for patients with CHD and ED.