Publications by authors named "V Ramana Chepuri"

A number of small molecule and protein therapeutic candidates have been developed in the last four years against SARS-CoV-2 spike. However, there are hardly a few molecules that have advanced through the subsequent discovery steps to eventually work as a therapeutic agent. This is majorly because of the hurdles in determining the affinity of potential therapeutics with live SARS-CoV-2 virus.

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Importance: The coronavirus disease 2019 (COVID-19) pandemic has changed health care delivery worldwide. Although decreases in hospitalization for acute myocardial infarction (AMI) have been reported during the pandemic, the implication for in-hospital outcomes is not well understood.

Objective: To define changes in AMI case rates, patient demographics, cardiovascular comorbidities, treatment approaches, and in-hospital outcomes during the pandemic.

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To determine the effects of dobutamine stimulation on myocardium distal to a coronary stenosis, transmural spatially localized phosphorus 31 nuclear magnetic resonance measurements of myocardial high-energy phosphate compounds (adenosine triphosphate and phosphocreatine), inorganic phosphate, and blood flow and systolic wall thickening were made in 8 open-chested dogs. Data were collected under (1) control conditions, (2) after the application of a moderate coronary stenosis, (3) during infusion of dobutamine with continuing stenosis, and (4) after the release of the stenosis with continuing dobutamine. Stenosis was associated with concordant reductions of subendocardial blood flow, wall thickening, and high-energy phosphate, and mild elevation of inorganic phosphate; subepicardial measurements were essentially unchanged.

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The response of the myocardium to prolonged or chronic ischemia may differ from the well documented changes that occur acutely subsequent to the onset of hypoperfusion. Therefore, we have examined in an instrumented canine model and using spatially localized spectroscopy to achieve transmural differentiation, the myocardial HEP and Pi levels as well as wall thickening in situ during prolonged ischemia induced by sustained coronary artery stenosis. The results demonstrate that subtotal coronary artery occlusion causes immediate and transmurally inhomogeneous decreases in the myocardial HEP content and increase in the Pi/CP ratio; however, during prolonged mild hypoperfusion, metabolic changes occur which lead to statistically significant recovery of CP (but not ATP) and disappearance of Pi despite the persistence of reduced blood flow and oxygen supply.

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The aerobic respiratory chain of Escherichia coli contains two terminal oxidases that catalyze the oxidation of ubiquinol-8 and the reduction of oxygen to water. They are the cytochrome o oxidase complex encoded by cyoABCDE and the cytochrome d oxidase complex encoded by cydAB. To determine how these genes are regulated in response to a variety of environmental stimuli, including oxygen, we examined their expression by using lacZ protein fusions in wild-type and fnr mutant strains of E.

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