An autopsy case of COVID-19 with a sudden death: Clinico-pathological comparison.

Autopsy was performed on a COVID-19 patient, who suddenly died despite the extensive anti-viral and anti-inflammatory therapies. Although moderate subpleural fibrosis was seen, pathology of DAD, a well-known cause for pulmonary failure, was minimum. Instead, severe hemorrhage was observed.

Ouabain increases sarcoplasmic reticulum calcium release in cardiac myocytes.

The inotropic and toxic effects of cardiac glycosides are thought to be related to their ability to inhibit the Na,K-ATPase. We examined the effects of ouabain and its analogs on sarcoplasmic reticulum (SR) Ca(2+) release in intact cat ventricular myocytes under Na(+)-free conditions and in myocytes in which the sarcolemma was permeabilized using saponin so that cytoplasmic ionic composition was fixed by the bath solutions. We also compared ouabain actions in cat myocytes to those in rat myocytes because the latter is considered to be a glycoside-insensitive species.

Effect of cardiac glycosides on action potential characteristics and contractility in cat ventricular myocytes: role of calcium overload.

There is increasing evidence that cardiac glycosides act through mechanisms distinct from inhibition of the sodium pump but which may contribute to their cardiac actions. To more fully define differences between agents indicative of multiple sites of action, we studied changes in contractility and action potential (AP) configuration in cat ventricular myocytes produced by six cardiac glycosides (ouabain, ouabagenin, dihydroouabain, actodigin, digoxin, and resibufogenin). AP shortening was observed only with ouabain and actodigin.

Positive inotropic effects of ouabain in isolated cat ventricular myocytes in sodium-free conditions.

The inotropic and toxic effects of cardiac steroids are thought to result from Na(+)-K(+)-ATPase inhibition, with elevated intracellular Na(+)(Na)causing increased intracellular Ca(2+)(Ca) via Na-Ca exchange. We studied the effects of ouabain on cat ventricular myocytes in Na(+)-free conditions where the exchanger is inhibited. Cell shortening and Ca transients (with fluo 4-AM fluorescence) were measured under voltage clamp during exposure to Na(+)-free solutions [LiCl or N-methyl-D-glucamine (NMDG) replacement].