[Features of pathological anatomy of COVID-19 according to autopsy results in the Volgograd Region]. / Osobennosti patologicheskoi anatomii COVID-19 po rezul'tatam autopsii v Volgogradskoi oblasti.

In connection with the ongoing pandemic of the novel coronavirus infection, the study of its morphopathology and the analysis of autopsy data are relevant. At the same time, attention should be paid to thromboses that play a significant role in the development of fatal outcomes in COVID-19, even taking into account the prescription of anticoagulant therapy to most patients. OBJECTIVE: To make an assessment of morphological changes and a statistical analysis of the structure of mortality in COVID-19 on the basis of autopsy results in the Volgograd Region in 2020. MATERIAL AND METHODS: The study was based on data from «The system for information on the work of the Volgograd Regional Autopsy Bureau¼ with a search for cases according to U07.1 code (the COVID-19 virus was identified) in January 1, 2020, to December 31, 2020, as well as on the autopsy materials of the Volgograd Regional Autopsy Bureau, and microscopic examination with photo fixation. Statistical processing was performed using the R programming language. RESULTS: During the above period, 1119 deaths were identified with a confirmed diagnosis of COVID-19. Anatomopathological examination of the autopsy material showed that 77.54% of cases had blood clots mainly in the vessels of the pulmonary microvasculature, often only in the single veins during the applied anticoagulant therapy.Analysis of variance indicated that the obtained result statistically significantly differed from the random distribution, and the probability of the presence of blood clots of specified localization was 3.17 times higher (CI 2.3-4.4; p<0.05) than their absence, as evidenced by logistic regression. In addition, perivascular and intra-alveolar diapedesis hemorrhages were noted in most fatal cases. CONCLUSION: Thus, this investigation has revealed that the high frequency of thrombosis detected in the presence of perivascular and intra-alveolar diapedesis hemorrhages in COVID-19 confirms the tendency of patients with a severe course of the disease to manifest hemostatic disorders, significant blood vascular endothelial injury, and obvious vascular impermeability.

[Morphological changes in the murine medulla during experimental West Nile virus (strain 986) infection].

The trends in antigen expression and structural changes in the medulla of albino mice infected by West Nile virus (WNV) were studied in different periods of an infectious process, by using monoclonal antibodies to WNV. The maximum amount of immunoreactive material was found in the damaged neurons of dead animals, although WNV antigen expression in the perikaryonic cytoplasm of individual neurons was observed in all the experimental groups. Small amount of neuronal immunoreactive material and its significant levels in the glial cells of symptomatic animals are regarded as a manifestation of individual differences in the neuronal microelement.