[COVID-19 and features of cardiovascular involvement].

The article provides an overview of current information on the pathogenesis of COVID-19 and organ-specific lesions developing in this disease. The data on inflammation and its biochemical markers, on the features of coagulopathy, endothelial damage and microthrombosis are presented in detail. Particular attention is paid to the role of receptors for angiotensin converting enzyme type 2 and transmembrane serine protease type 2 in the development of organ-specific lesions in COVID-19. The pathogenesis of damage to the cardiovascular system is considered in detail with the presentation of data from foreign literature on changes in the myocardium and the author's results of transthoracic echocardiographic examination in patients who have undergone COVID-19.

[Neurological manifestations of HIV-infection (review)].

Current data on the etiology, pathogenesis, diagnosis and treatment principles of HIV are reviewed. The special attention is focused on affections of the nervous system (neuro-AIDS). Primary and secondary manifestations of these affections are described.

[HCV genome variability in acute and chronic viral hepatitis C].

AIM: To evaluate HCV genome variability in acute and chronic phases of viral hepatitis C. MATERIAL AND METHODS: The study of heterogeneity of HCV in acute hepatitis C has detected genetic heterogeneity and variability of individual HCV population circulating in the blood. Significant genetic heterogeneity of HCV was observed in 1b, 2a and 3a genotypes. Variability of HCV did not depend on virus load. Genetic HCV structure changed significantly both in patients with manifest ALT deviations and in normal ALT, mean number of HCV genetic variants in these groups being the same. No significant correlations were found between virus concentration in the patient's blood, its variability and ALT values. Genetic heterogeneity of interferon-sensitive region of gene NS5A subtype 1b HCV was studied in blood of 16 patients with chronic hepatitis C resistant to interferon therapy. RESULTS: It is shown that genetic heterogeneity and variability of an individual HCV population circulating in blood serum can not be a prognostic criterion in assessment of variants of acute hepatitis C course. No mutations in ISDR region were found in 25% of 16 patients studied. 75% cases had 1-3 replacements of amino acid sequences, most frequent mutation was replacements in position 2218 (histidin/arginin). The above results are close to those obtained in Japanese and European populations. Results of ISDR sequence-analysis conducted before treatment may predict efficacy of interferon-alpha2 treatment in an individual patient in future. Large-scale trials are necessary for detection of mutations responsible for resistance to interferon-alpha2 in patients living in Russia.

[Acute hepatitis of unspecified etiology: etiological structure and clinical-laboratory characteristics].

The straight line nucleic acids detection method of viruses and wide spectrum of virus antigens immunodiagnostics in acute hepatitis of unknown etiology patients has allowed verifying the diagnosis at 19% cases (a viral hepatitis A, C or E). Results of research do not allow to consider hepatotropic viruses HGV, TTV, PV B19, EBV, CMV, HHV 1, 2, 6 and 8 type, NV-F as etiological agents at the majority of patients of investigated group, and the data of the anamnesis and a clinical and laboratory picture of a current of disease does not allow to exclude at 29.4% of patients a drug-induced hepatitis. Despite detailed molecular-biological and immunological inspection of patients, at 37.9% of acute hepatitis of unknown etiology patients it was not possible to establish a connection with hepatitis and defined etiological factor (the infectious agent).

[Role of host in spontaneous recovery from viral hepatitis C: the body's condition at the moment of infection].

The condition of the host at the moment of infection is that its immune competence largely determines the efficiency, kinetics, and profile (Thl/Th2) of a further specific immunity response and, accordingly, the outcome of penetration of hepatitis C virus (HCV) into the body and subsequent acute infection (if it occurs). The parameters determining immune competence may include age, traumatizing exposures (operations, burns, wounds, and fractures), immunosuppressive therapy, stresses, con-infections, and alcohol use. The highest rates of spontaneous convalescence from HCV infection are observed in children and adolescents. Other human conditions are much shorter, transient; their impact is difficult to determine in the retrospective review and therefore it has not been adequately studied. Previous operations, posttransplantation immune suppression, immune modulation after blood transfusion, alcohol-induced immune imbalance, drug and narcotic intoxication are poor predictors. Immunosuppression and immune imbalance caused by viral and parasitic infections are observed among the host's temporary conditions affecting the outcome of HCV infection. The authors have analyzed the sequels of superinfections in patients with chronic hepatitis C, other hepatotropic viruses and the common liver fluke Schistosoma mansoni. The interesting therapeutic activities against HCV and parasitic infection (contamination with Echinococcus granulosus in particular), which are shown in the treatment of co-infection patients with alpha-interferon preparations that ensure normalization of immune deficiency caused by each of the infections and their increased combination. A deeper insight into the correlation between the condition of the host and its ability to eliminate the virus may be one more step on the road to the prevention of the infection and to the designing an effective vaccine against HCV.