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Biomedical subjects

E Adams

Publications and source records attributed to E Adams.

At least 109 records · Page 6Linked to original sources
PubMed1984

Human antigen-specific IgA responses in blood and secondary lymphoid tissue: an analysis of help and suppression.

Antigen-specific IgA responses to influenza virus were obtained from lymphocytes derived from human secondary lymphoid tissue but not from the circulating pool (blood). T helper cells for IgA were present in both the circulating pool and secondary lymphoid tissue, were of the Leu-3A+ subset, and were relatively radioresistant. In addition, T alpha cells were shown to be important, but not crucial, for IgA helper responses. T cell-dependent suppression of IgA responses was demonstrated with T cells from both mucosal and systemic lymphoid tissue and was mediated by a radiosensitive Leu-2a+ cell. In contrast to T cells, functional B cell precursors for antigen-specific IgA responses were found only in secondary lymphoid tissue and not in the circulating pool.

Antibodies, Viral↗
PubMed1982

Inappropriately low serum GH in an acromegalic: lysosomal involvement in intracellular hormone degradation.

A patient with galactorrhea, amenorrhae and severe acromegaly was found to have a large pituitary adenoma. In view of the severity of the disease the serum growth hormone (GH) level (22.5 mlU/liter) was considered inappropriately low. Tissue from the adenoma was obtained during successful treatment with interstitial irradiation. (90Yttrium). Trypsin-dispersed biopsy cells in culture for 12 days secreted low amounts of GH compared to the same number of adenoma cells from 5 other unselected acromegalics or a normal pituitary. No other hormones were secreted in culture. Immunocytochemical staining was positive only with GH antisera but showed low intracellular content. This was confirmed by direct analysis of the tumor tissue which showed the GH content to be only 20% of that found in 5 normal pituitaries and 4% of that found in 8 other adenomas from acromegalics. Electron microscopy showed a striking appearance, with GH secretory granules that were sparse in number, smaller than usual, and in the main arranged around numerous intracellular profiles with double membranes and low electron density that were tentatively identified as autophagic vacuoles (secondary lysosomes). Subcellular fractionation showed the distribution of the radioimmunoassayable GH in the gradient to be coincident with the peak of the lysosomes whereas in 2 other acromegalics the GH peak was clearly separated from the lysosomes. We conclude that the simultaneous appearance in our patient of the relatively low serum GH together with a large tumor and severe acromegaly can be explained biochemically by the striking finding of crinophagy - disposal of hormone secretory granules within the somatotroph cells themselves.

Acromegaly↗
PubMed1981

Secretion of LH, FSH, and PRL shown by cell culture and immunocytochemistry of human functionless pituitary adenomas.

Hormone secretion by ten functionless human pituitary adenomas in cell culture has been measured, and compared with tissue immunocytochemistry and electron microscopy, as well as results with a normal pituitary. Patients presented following routine x-ray and had no clinical or biochemical endocrine abnormality apart form one male with raised serum FSH and PRL, normal LH, and low testosterone. Of the ten adenomas, nine secreted both LH and FSH in cell culture and five of these also secreted PRL, one did not secrete any anterior pituitary hormones (ACTH was not measured). No GH or TSH was detectable in the cultures of the nine LH/FSH secretors excluding the possibility of contamination by normal anterior pituitary. The normal pituitary cells secreted all anterior pituitary hormones: the amounts of FSH/LH being comparable with those of the adenomas. Immunostaining confirmed the cell culture results and showed the adenoma FSH/LH cells to be scattered singly or in small groups of two to five cells with both hormones usually being in the same cell. PRL where found was in separate cells. Hormone granules were small (50-160nm), round or irregular and scattered in the cytoplasm of rounded cell of low secretory activity. The negatively staining cells were not different ultrastructurally to those staining positively. It is concluded that a significant proportion of functionless pituitary adenomas have detectable low levels of LH/FSH secretion often accompanied by PRL when examined by cell culture or immunocytochemistry. Although these adenomas were endocrinologically quiescent activity could have been masked because of post-menopausal secretion and one male probably had and FSH-secreting adenoma.

Adenoma, Chromophobe↗
PubMed1981

Alterations in T gamma cells in patients with chronic idiopathic thrombocytopenic purpura.

The number and percentage of T cells bearing Fc gamma receptors (T gamma) was quantitated in peripheral blood of patients with the autoimmune disease chronic ITP. In over half the patients, low initial percentages were obtained, the great majority of which returned to within the normal range after incubation under capping conditions. The phenomenon could be reproduced by pretreating normal T cells with immune complex containing sera or aggregated HGG. Furthermore, a reversible reduction in T gamma cells was observed in control patients with nonimmune thrombocytopenia and in pregnancy. In each case an association was observed between the reduced T gamma cell levels and the presence of circulating immune complexes, which suggested that the results could be explained by masking of Fc gamma receptors with preformed IgG-containing complexes. By contrast, patients with other autoimmune diseases such as scleroderma and rheumatoid arthritis had high or normal numbers of T gamma cells, respectively. Taken together, the findings do not support the existence of a gross deficiency of suppressor cells in patients with autoimmune disease and emphasize the need for caution in selection of markers for identification of T cell subsets.

Animals↗
PubMed1980

Thymoma and late onset mucocutaneous candidiasis associated with a plasma inhibitor of cell-mediated immune function.

A case is described of chronic mucocutaneous candidiasis in association with thymoma. A plasma inhibitor of certain in vitro tests of cell mediated immune function, both of autologous and of normal cells was isolated from the patient's blood and shown to be stable on heating to 56 degrees C for 1 hour and to freezing and thawing. Isolation of the active fraction of Sephadex G-200 suggested a m.w. of 50,000-65,000 daltons. Despite disappearance of the inhibitor after apparently curative radiotherapy, suggesting the tumour was the origin, the chronic mucocutaneous candidiasis persists. The association of plasma inhibitors of immune function, with and without thymoma and chronic mucocutaneous candidiasis is reviewed and the possible nature of the substance discussed.

Aged↗
PubMed1978

Invertebrate collagens.

The collagens of all major invertebrate phyla have been studied, but characterization has been thorough in only a few classes and in no case in the detail (such as sequence analysis) known for vertebrate collagen. Biochemical data on insect collagen are particularly sparse. Invertebrate and vertebrate collagens are strikingly similar, with some notably unique features in annelids and nematodes. Present data do not support the suggestion that invertebrate collagens resemble vertebrate basement membrane collagen. In invertebrates, as in vertebrates, collagens of specific tissues show differenes that probably reflect individual tissue requirements.

Amino Acid Sequence↗
PubMed1978

Bacterial utilization of cyclo(glycl-L-prolyl).

3 strains of soil bacteria (2 Achromobacter, 1 Flavobacterium) were isolated by growth on cyclo(Gly-L-Pro) as carbon/nitrogen source. Good growth required yeast extract supplements. Utilization of cyclo(Gly-L-Pro) was inducible. Many efforts failed to obtain active cell-free preparations. Injected radioactive cyclo(Gly-L-Pro) was excreted intact by the albino rat; in contrast, injected radioactive H-Gly-L-Pro-OH was extensively metabolized.

Dipeptides↗