COVID-19 severity in relation to sociodemographics and vitamin D use.

Most COVID-19 cases are treated as outpatients, while the majority of studies on COVID-19 focus on inpatients. Little is known about the self-reporting and self-rating of the disease's symptoms, and the associations of prophylactic use of dietary supplements with COVID-19 severity have not been addressed. The aims of this study are to evaluate COVID-19 severity and to relate them to sociodemographic characteristics and prophylactic dietary supplements.

Fluorescence Approaches to Image and Quantify the Demarcation Membrane System in Living Megakaryocytes.

The demarcation membrane system (DMS) develops to provide additional surface membrane for the process of platelet production. The DMS is an invagination of the plasma membrane that can extend throughout the extranuclear volume of mature megakaryocytes and its lumen is continuous with the extracellular solution. DMS ultrastructure in fixed samples has been extensively studied using transmission electron microscopy (TEM) and more recently with focused ion beam scanning EM.

Detachment of surface membrane invagination systems by cationic amphiphilic drugs.

Several cell types develop extensive plasma membrane invaginations to serve a specific physiological function. For example, the megakaryocyte demarcation membrane system (DMS) provides a membrane reserve for platelet production and muscle transverse (T) tubules facilitate excitation:contraction coupling. Using impermeant fluorescent indicators, capacitance measurements and electron microscopy, we show that multiple cationic amphiphilic drugs (CADs) cause complete separation of the DMS from the surface membrane in rat megakaryocytes.