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Biomedical subjects

P Wijermans

Publications and source records attributed to P Wijermans.

26 records · Page 2Linked to original sources
PubMed1980

Influence of adult thymectomy on immunocompetence in patients with myasthenia gravis.

The influence of adult thymectomy on several parameters of immunocompetence in patients with myasthenia gravis (MG) was investigated. Since incomplete thymectomy may lead to the presence of thymic remnants, we determined the activity of a thymus-dependent factor in the sera of the MG patients. As measured by several parameters, MG patients showed a normal immunocompetence compared with healthy controls, except in the response to DNCB sensitization in vivo. When tested at least 5 years after thymectomy, MG patients were found to have decreased response to mitogens, and a decreased cytotoxic T cell response in cell-mediated lympholysis. The response to challenge with DNCB in vivo was decreased both in thymectomized and nonthymectomized MG patients. No difference was found in a) the percentage of circulating T, B, non-B/non-T cells; b) the response to allogeneic cells (MLR); c) the antibody-dependent lymphocytotoxicity; d) the production of immunoglobulins in vitro by pokeweed mitogen-stimulated cells; and e) the anamnestic response to antigens in vitro. We conclude that adult thymectomy results in a decrease in the function of some subpopulations of lymphocytes.

Adult↗
PubMed1978

Experiences with thymosin in primary immunodeficiency disease.

Thymosin has no effect in vitro on cyclic AMP levels in thymocytes. However, when thymosin was injected into patients lacking "serum factor" (SF) activity, it induced the appearance of SF or SF-like activity and the disappearance of target cells for SF among the peripheral blood lymphocytes of the treated patients. On the other hand, when thymosin was injected into one patient with normal SF activity, it induced a marked decrease of SF activity and the appearance of target cells for SF among the peripheral blood lymphocytes of this particular patient.

Animals↗
PubMed1977

Effect of a human serum thymic factor on hydrocortisone-treated thymocytes.

A human serum thymic factors (SF) stimulated cyclic adenosine-3' ,5'-monophosphate (cAMP) synthesis in normal mouse thymocytes. Such stimulation was no longer observed when thymocytes were depleted of hydrocortisone (HC)-sensitive cells. It was concluded that SF selectively stimulate cAMP in HC-sensitive cells. Furthermore, incubation of thymocytes with SF enlarged the population of HC-resistant thymocytes. These results suggest that SF might act on HC-sensitive thymocytes increasing their cellular cAMP level and inducing their transformation in HC-resistant cells.

Animals↗
PubMed1977

Thymosin-induced human serum factor increasing cyclic AMP.

Thymosin has virtually no in vitro effect on cyclic AMP levels in thymocytes and seems not to react with either the beta-adrenergic receptor or with the putative human serum thymic factor (SF) receptor. However, when thymosin is injected into patients lacking SF activity, it induces the appearance of a serum factor which increases cellular cyclic AMP levels in thymocytes in vitro. This factor appears to act on a membrane site distinct from the beta-adrenergic receptors.

Animals↗