Ultrastructural Reorganization of Endotheliocytes of Pulmonary Blood Capillaries in COVID-19.

The ultrastructural organization endotheliocytes of pulmonary blood capillaries in COVID-19 was studied on autopsy material using electron microscopy. Swelling of the cytoplasm and mitochondria with destruction of the cristae, dilation of the Golgi complex cisternae, a decrease in the volume density of the luminal and basal caveolae and free transport vesicles, an increase of the rough endoplasmic reticulum, as well as the presence of elements of coronavirus replication (reticulovesicular structures, zippered endoplasmic reticulum, electron-dense particles in the Golgi cisternae, and vacuoles with viral particles) were revealed. Further studies of the intracellular mechanisms used by the virus to replicate could help to develop antiviral drugs for the treatment of the new coronavirus infection.

[Clinical and anatomical analysis of mortality from COVID-19 in sudden death and in those who died in health care facilities]. / Kliniko-anatomicheskii analiz letal'nosti ot COVID-19 pri skoropostizhnoi smerti i u umershikh v lechebno-profilakticheskikh uchrezhdeniyakh.

OBJECTIVE: Assessment of pathological and morphological changes in those who died from COVID-19 including persons received therapy in medical and preventive institutions (LPI) and who died suddenly from this pathology at home. The analysis data of the pathological and anatomical changes in 57 deaths from COVID-19 in hospitals and 74 forensic medical examinations where infectious pathology was established as the main cause of death are presented. For microscopy the sections were stained with hemotoxylin and eosin, OCG, immunohistochemical study with markers for CD3, CD 4, CD 20, SK-7. The mixed viral and bacterial lesions of the lungs were detected more often than pure viral infection in those who died suddenly from COVID-19 compared with people whose death occurred in medical facilities. This allows speaking about the lack of adequate antibiotic therapy out-patiently. Features of mononuclear lung infiltration in COVID-19 with a predominance of a moderately pronounced reaction of T-lymphocytes and a mild B-lymphocytic reaction indicate a decrease in immunological reactivity. Conducting clinical and anatomical analysis allows determining the features of pathogenesis and morphogenesis in each specific fatal case and informing the clinicians of health facilities (clinics and hospitals) allows the autopsy doctor (pathologist, forensic physician) to provide significant assistance in improving the quality of diagnosis and treatment of patients with this highly contagious severe viral disease.