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Biomedical subjects

M G Bryant

Publications and source records attributed to M G Bryant.

At least 55 records · Page 3Linked to original sources
PubMed1977

Specific immunostaining of CCK cells by use of synthetic fragment antisera.

Antibodies to the central fragments 9-20 dodecapeptide sequence of CCK were used for specific immunostaining of the CCK cells of the mammalian gut. The use of high specific antibodies to synthetic fragment, essential when there is a possibility of immunochemical cross reactions between antisera and hormones of similar molecular structure provides the key to increased understanding of the nature and relationships of peptide hormones.

Antibody Specificity↗
PubMed1976

Possible dual role for vasoactive intestinal peptide as gastrointestinal hormone and neurotransmitter substance.

Vasoactive intestinal peptide (V.I.P.) has been found in high concentrations both in the gastrointestinal tract and, unexpectedly, in the central nervous system. Immunocytochemical studies have demonstrated V.I.P. in nerve-fibers. These findings challenge the concept of V.I.P. as a simple gastrointestinal hormone and suggest a possible neurotransmitter function.

Adrenal Glands↗
PubMed1976

Pancreatic polypeptide in insulinomas, gastrinomas, vipomas, and glucagonomas.

In 33 patients studied with endocrine neoplasms of the pancreas more than half the tumours contained pancreatic polypeptide (P.P.) producing cells, and a high radioimmunoassayable concentration of P.P. was found in the tumour extracts. Plasma was available from 28 patients, and very high circulating P.P. concentrations were found in 18. The presence of P.P. in hepatic and lymphnode metastases indicates that its production by the primary neoplasm cannot be ascribed to incidental adherence of normal P.P. cells. Measurements of plasma P.P. levels should be a new aid to diagnosis of pancreatic tumours.

Adenoma, Islet Cell↗
PubMed1976

Distribution and release of human pancreatic polypeptide.

A simple and reliable radioimmunoassay has been developed for a new gut hormone, HPP. In the primate 93% of the total PP was found in the pancreas with a small amount throughout the remaining gastrointestinal tract. HPP has been shown to be produced by a number of pancreatic apudomas and their metastases. The immunoreactive PP from these tumours and from normal pancreas was chromatographically indistinguishable from the pure peptide. The plasma PP concentration rose rapidly after a meal in normal subjects and was still raised six hours later. Fasting plasma PP levels in patients with PP cell containing pancreatic endocrine tumours were higher than even the postprandial level in normal subjects. PP measurements is thus useful in diagnosis of pancreatic endocrine tumours.

Animals↗
PubMed1976

Current problems in the measurement of gastrin release. A reproducible measure of physiological gastrin release.

The interpretation of gastrin release is confused because of variation in the technique of the radioimmuoassay of gastrin, the lack of a standard stimulus for the release of gastrin and diversity in the method used to express the results. These problems have been analysed (a) by examining the cross-reactivity of three gastrin antisera and using each of the antisera to measure basal gastrin levels in fasting normal subjects, duodenal ulcer and post-vagotomy patients; (b) by determining a satisfactory stimulus for gastrin release in normal subjects; (c) by examining the results to determine the best method of presenting the data. The different a ntisera used were found to give different levels of plasma gastrin in the same sample of plasma. This was not related to the cross reactivity of the antisera. An English breakfast was found to be the most satisfactory stimulus for the release of gastrin. The expression of the results of such a stimulus of gastrin release was affected least by assay variation when the incremental integrated gastrin response was used. It is concluded that the incremental integrated gastrin response to an English breakfast is a satisfactory method for exploring variations in gastrin release.

Adult↗
PubMed1976

Measurement of human plasma motilin.

A specific radioimmunoassay has been developed for human plasma motilin. No cross reaction was seen with other gut hormones and only a single major peak of motilin immunoreactivity was found in plasma and gut extracts after gel chromatography. The motilin content of the human duodenum was 165.7+/-15.9 pmol/g wet weight and jejunum 37.5+/-2.8 pmol/g with negligible amounts in the rest of the gut. Fasting plasma motilin concentrations in 100 healthy subjects ranged from less than 5 to 300 pmol/l (mean 72 pmol/l).

Adult↗