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Biomedical subjects

M Barton

Publications and source records attributed to M Barton.

137 records · Page 8Linked to original sources
PubMedDate not supplied

Endothelin in heart failure.

Congestive heart failure is a complex disease that results from pumping failure of the cardiac muscle and adaptational processes of the cardiovascular system to correct for the reduced blood supply to the organism. It is associated with increased vasoconstriction and impaired vasodilation in response to physical activity. The elevated vasoconstrictor tone is caused by the activation of compensatory mechanisms including the sympathetic nervous system and stimulation of the release of neurohormones like angiotensin II, catecholamines, and vasopressin. Furthermore, the vascular endothelium is importantly involved in the regulation of vascular tone as it releases a variety of vasoactive substances that act locally and systemically. In congestive heart failure, there is a marked imbalance between the diminished release or the increased inactivation of vasodilators on the one hand, ie, nitric oxide, and the elevated production, release, or reduced inactivation of vasoconstrictors such as endothelin-1 on the other hand. In addition to its very potent vasoconstrictor effects, endothelin-1 possesses antinatriuretic and mitogenic properties that are a common feature of substances that are involved in development of the deleterious consequences that render congestive heart failure a lethal disease. The spectrum of action of the endothelin system and the advent of specific antagonists for its receptors have made this system a very interesting target for clinical research and possibly for future therapeutic approaches.

Animals↗
PubMedDate not supplied

Identification of koala T lymphocytes using an anti-human CD3 antibody.

Previous attempts to identify T lymphocytes in the koala using cross reacting monoclonal antibodies (mAbs) against other species T cell antigens (Ags) and classical T cell lectins have proved unsuccessful. Recently a polyclonal rabbit Ab preparation directed at the epsilon chain of the human CD3 complex (anti-CD3) has become commercially available and has been shown to have broad cross-species reactivity. We have demonstrated that this anti-CD3 is suitable for labelling T cells from peripheral blood of koalas if the purified peripheral mononuclear cells (PMC) are first made permeable with mild fixation in buffered formal acetone. We have also been able to identify koala T cells in both formalin-fixed and frozen lymphoid tissues. Immunoprecipitation and Western blotting studies demonstrated that this anti-CD3 bound to a single 23 kDa polypeptide, probably representing the koala homologue of the human epsilon chain. This is the first report of successful identification of koala T cells and the first reported use of this anti-CD3 for the identification of peripheral circulating T lymphocytes in any species.

Amino Acid Sequence↗