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Biomedical subjects

M Waterman

Publications and source records attributed to M Waterman.

26 records · Page 2Linked to original sources
PubMed1985

Molecular mechanisms of phorbol ester, thyrotropin-releasing hormone, and growth factor stimulation of prolactin gene transcription.

The polypeptide thyrotropin-releasing hormone (TRH) and epidermal growth factor (EGF) stimulate, within seconds to minutes, the transcription of the prolactin gene in a rat pituitary cell line (GH4). Because a series of agents that act to stimulate prolactin secretion fail to alter prolactin gene transcription, it is suggested that secretory events are neither obligatory for nor causal of hormone-induced transcriptional stimulation. Elevation of cytosolic-free calcium does not stimulate prolactin gene transcription; however, several agents that act to antagonize calcium-dependent processes inhibit or abolish both TRH and EGF stimulation of prolactin gene transcription and a specific hormone-dependent nuclear phosphorylation. In contrast, inhibitors of the slow calcium channel exert minimal effects on TRH-stimulated prolactin gene expression, suggesting that calcium influx through membrane channels is not crucial for the observed nuclear actions of TRH. Activation of protein kinase C by phorbol esters mimics the nuclear actions of TRH. In the presence of increased intracellular calcium levels, the effects of 12-O-tetradecanoyl phorbol 13-acetate on prolactin gene transcription are quantitatively identical to those observed in response to TRH or EGF.

Animals↗
PubMed1985

Cyclic AMP regulation of eukaryotic gene transcription by two discrete molecular mechanisms.

In experiments designed to study the mechanism by which peptide hormones binding to their plasma membrane receptors stimulate the expression of specific genes, the transcription of two neuroendocrine genes, prolactin and growth hormone, was analyzed in a rat pituitary cell line. The results showed that cyclic adenosine monophosphate (cyclic AMP) stimulates the transcription of discrete subsets of eukaryotic genes by at least two independent molecular mechanisms. Cyclic AMP stimulated growth hormone gene transcription and phosphorylation of a 19,000-dalton nuclear protein; this appears to reflect direct nuclear actions of the cyclic AMP-dependent protein kinase. In contrast, the stimulation by cyclic AMP of prolactin gene transcription appears to reflect activation of a discrete calcium-dependent event.

Animals↗
PubMed1978

Detection of myoglobin by radioimmmunoassay in human sera: its usefulness and limitations as an emergency room screening test for acute myocardial infarction.

The results indicate that serum myoglobin determinations may be obtained by radioimmunoassay utilizing time periods for the testing which allow more useful clinical evaluation of patients. The data also demonstrate, however, that there are important temporal considerations in using serum myoglobin levels for the detection of acute myocardial infarcts and, if this test is used to determine in the Emergency Room whether patients have had acute myocardial infarcts, these limitations will have to be kept in mind. In addition, three other patient subgroups that might be expected to have elevated serum myoglobin levels by radioimmunoassay have been determined. These include patients with shock (irrespective of etiology), patients with severe renal insufficiency, i.e., those with serum creatinine levels equal to or greater than 8 mg. per cent, and possibly patients who have been on alcohol binges immediately prior to being seen in the Emergency Room.

Acute Disease↗
PubMed1977

E.s.r. radiation studies of erythrocyte membrane haemoglobin interaction.

The dependence of the yield of free radicals in gamma-irradiated, freeze-dried erythrocyte membranes on their haemoglobin content was studied. A non-monotonous relationship was found--different from that observed in mixtures of freeze-dried membranes and haemoglobin, which suggests the existence of radiation-energy transfer between the membranes and bound haemoglobin.

Electron Spin Resonance Spectroscopy↗
PubMedDate not supplied

Emotion in language and speech: methodological issues in naturalistic approaches.

Researchers currently seek to improve validity in speech and language studies by adopting naturalistic procedures In emotion-display research, validity is threatened by standard experimental controls which diminish the naturalism of stimuli and response ranges. We report two experiments comparing the adequacy of naturalistic with standard procedures. Experiment 1 had 158 judges code 89 samples of naturally-occurring emotional speech with free-choice emotion labels, and later with labels from a standard set. When free-choice labels were similar across judges, they were consistent with standard labels, but showed a range of intensity and contextual relevance. We recommend that future studies include wider options for judges when coding emotions. Experiment 2 compared valency ratings of words when presented in, or out of, context. Standard procedures score lexical valencies using affective dictionaries, disregarding natural contexts. Experiment 2 compared 23 judges' valency ratings of words presented individually, and later in their original context. Between 30% and 44% of words were rated differently in context (depending on the statistical significance level adopted). We concluded from Experiment 2 that, where small corpora adequately model a domain, the improved accuracy of valency rating achieved by presenting words in their natural context justifies the extra procedures required.

Adult↗