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Biomedical subjects

W Born

Publications and source records attributed to W Born.

148 records · Page 9Linked to original sources

Distinct hemodynamic and gastric effects of human CGRP I and II in man.

The human calcitonin gene-related peptides I and II (or alpha and beta) (CGRP I and II) are encoded by two different genes, but they have 34 of the 37 amino acid residues in common. Human CGRP I more potently stimulated blood flow through the skin and carotid artery (p less than 0.01), and the heart rate (p less than 0.05), and plasma renin activity and aldosterone secretion than human CGRP II (p less than 0.02). Inhibition of pentagastrin-stimulated gastric acid output, on the other hand, was only obtained with CGRP II. The separate effects of human CGRP I and II on the cardiovascular and gastric systems are presumably mediated by different receptors or receptor pathways recognized by the two closely related neuropeptides.

Adult↗

Peptide sequences of T-cell receptor delta and gamma chains are identical to predicted X and gamma proteins.

Although most mature peripheral T lymphocytes express a major histocompatibility complex restricted, CD3-associated, antigen receptor (TCR) which has been well characterized, some T cells carry a different CD3-associated heterodimer on their surface. One of the two disulphide-linked chains of this putative second receptor, which in mice has relative molecular mass (Mr) 35,000 (35K), has been identified as a product of the group of gamma genes. The other chain, termed delta (Mr 45K in mice), is not as well characterized. Although gamma/delta-bearing cells are a minor subset among peripheral T lymphocytes, they are the only CD3+ cells in the thymus early in ontogeny. Taking advantage of these kinetics, we have generated gamma/delta-bearing hybridomas, using a new TCR alpha chain-negative variant of the AKR thymoma BW5147 as tumour parent, fetal thymocytes as normal cell partners, and an anti-CD3 monoclonal antibody (mAb) as screening reagent. Gamma and delta chains from one of these hybrids have been purified and partially sequenced. The sequences obtained indicate that delta is indeed identical to the polypeptide encoded by the recently described gene X, as suggested by Chien et al.

Amino Acid Sequence↗

T-cell receptor delta gene rearrangements in early thymocytes.

The T-cell receptor delta-chain variable region can be assembled from as many as four distinct gene segments, V, D1, D2 and J, more than any other antigen-receptor gene. In fetal thymocytes V----D joinings are as common as D----J or VDJ rearrangements and one V gene segment predominates. Analysis of rearrangements at TCR gamma and delta loci during fetal ontogeny suggests abrupt changes and possible coordinate control in the rearrangement and expression of these loci.

Age Factors↗

[Calcitonin gene products and the skeleton].

Calcitonin is the most important hypocalcaemic peptide. Its action is brought about through inhibition of bone resorption. CGRP exerts the same effect on the skeleton albeit in much higher concentrations probably through interaction with calcitonin receptors on osteoclasts. PAS-57 stimulates the incorporation of thymidine into osteoblasts. A possible stimulation of bone formation needs to be verified in vivo.

Bone Resorption↗