Intracellular organelles remodeling in myocardial endotheliocytes in COVID-19: an autopsy-based study.

It is known that the unfavorable outcome in patients infected with SARS-CoV-2 may be associated with the development of complications caused by heart damage due to the direct virus action. The mechanism of these cardiovascular injuries caused by SARS-CoV-2 infection has not been fully understood; however, the study of COVID-19-associated myocardial microcirculatory dysfunction can represent the useful strategy to solving this challenge. Thus, here we aimed to study the ultrastructural organization of endothelial cells of myocardial capillaries in patients with COVID-19.

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].

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.