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T J Murphy

Publications and source records attributed to T J Murphy.

78 records · Page 5Linked to original sources
PubMedDate not supplied

Molecular characterization of angiotensin II type II receptors in rat pheochromocytoma cells.

The binding sites and biochemical effects of angiotensin (A) II were investigated in rat pheochromocytoma (PC12W) cells. Sarcosine1, [125I]-tyrosine4, isoleucine8-AII ([125I]-SI-AII) bound to a saturable population of sites on membranes with an equilibrium dissociation constant (Kd) of 0.4 nM and a binding site maximum of 254 fmol/mg protein. Competitive displacement of [125I]-SI-AII by agonists and antagonists elucidated a rank order of potency of AIII greater than or equal to AII greater than PD 123177 greater than AI greater than [des-Phe]AII [AII(1-7)] much greater than DuP 753. The stable guanine nucleotide analog 5'-guanylyl imidodiphosphate did not alter the binding affinity or slope of the inhibition curves for AI, AII, AIII, or AII(1-7). Treatment of PC12W cells with AII or AIII did not affect the free intracellular calcium concentration, phosphoinositide metabolism, arachidonate release, cyclic GMP, or cyclic AMP concentrations. [125I]-AII binding sites remained on the cell surface and were not internalized after 2 h at 37 degrees C. Angiotensin II did not stimulate tyrosine, serine, or threonine phosphorylation. Northern analysis of PC12W mRNA with an AT1 receptor gene probe failed to produce an RNA:DNA hybrid at low stringency. These data indicate that PC12W cells express a homogeneous population of AT2 binding sites which differ significantly from AT1 receptors in signal transduction and molecular structure. AT2 sites may act via potentially novel, biochemical pathways or, alternatively, be vestigial receptors.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

Pulsus alternans with alternation of mitral flow and motion patterns.

A 41-year-old man with dilated cardiomyopathy had persistent pulsus alternans on physical examination and on cardiac catheterization. On M-mode echocardiography patterns of mitral valve diastolic motion showed alternation such that the E phase was longer and the A phase shorter after stronger ventricular contractions. At faster rates the A peak was apparently absent in alternate diastoles. Doppler recordings of mitral flow exhibited alternation such that the peak velocity and duration of early diastolic flow were larger after stronger ventricular contractions; diastolic mitral regurgitation was noted only in such (alternate) diastoles.

Adult↗
PubMedDate not supplied

Future time perspective in alcoholics, process and reactive schizophrenics, and normals.

Future time perspective was investigated in alcoholics, process and reactive schizophrenics, and hospitalized medical patients. The four groups, of 24 subjects each, were compared on measures of future extension, coherence, density, and directionality based on Kastenbaum's model of future time perspective. Process and reactive schizophrenics differed only in future coherence, with reactives significantly more coherent. Both alcoholics and normals showed significantly greater future extension (on one of two extension measures) than both groups of schizophrenics. Future coherence for alcoholics and normals was significantly greater than for process schizophrenics but not greater than for reactives. Alcoholics had significantly greater future density than schizophrenics and normals. Alcoholics showed significantly greater future coherence than normals. The greater future density and coherence for alcoholics than normals appeared to be due to sampling and situational differences. These results suggested that future time perspective deficits are temporary for alcoholics and that long-range treatment goals can be appropriate for them.

Alcoholism↗