Nathaniel J Hart

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The long-term effects of captopril therapy were assessed by sequential hemodynamic studies over a 6 month period in 19 patients with resistant congestive heart failure. Initial improvement during the first week of therapy was noted only in 11 and was marked by significant (p less than 0.005) increases in cardiac output and stroke volume, slowing of heart(More)
Children from diabetic pregnancies have a greater incidence of type 2 diabetes. Our objective was to determine if exposure to mild-moderate hyperglycemia, by modeling managed diabetic pregnancies, affects fetal β-cell function. In sheep fetuses, β-cell responsiveness was examined after 2 weeks of sustained hyperglycemia with 3 pulses/day, mimicking(More)
Treatment with captopril in resistant normotensive congestive heart failure is associated with a pronounced reduction in blood pressure, particularly after the first dose. The effects of this reduction on renal function were assessed in 10 patients at the beginning of and during chronic treatment (at one week and three months). Renal plasma flow and(More)
G protein-coupled receptor (GPCR) cell signalling cascades are initiated upon binding of a specific agonist ligand to its cell surface receptor. Linking multiple heterologous ligands that simultaneously bind and potentially link different receptors on the cell surface is a unique approach to modulate cell responses. Moreover, if the target receptors are(More)
The scarcity of human cadaveric pancreata limits large-scale application of islet transplantation for patients with diabetes. Islets isolated from pathogen-free pigs provide an economical and abundant alternative source assuming immunologic barriers are appropriate. Membrane receptors involved in insulin secretion that also have potential as imaging targets(More)
In an attempt to study the possible mechanism(s) by which captopril controls resistant heart failure, sequential haemodynamic studies (radioisotope technique) and humoral measurements (plasma renin activity, plasma aldosterone and plasma catecholamines) were obtained in 11 such patients. The studies were made at the time patients became unresponsive to(More)
Inadequate pancreatic β cell function underlies type 1 and type 2 diabetes mellitus. Strategies to expand functional cells have focused on discovering and controlling mechanisms that limit the proliferation of human β cells. Here, we developed an engraftment strategy to examine age-associated human islet cell replication competence and reveal mechanisms(More)