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Biomedical subjects

D Brohée

Publications and source records attributed to D Brohée.

At least 37 records · Page 2Linked to original sources
PubMed1988

E-rosettes in aging: meta-analysis of the literature.

In this meta-analysis of the literature, it is affirmed that aging is associated with a small but significant decline in peripheral E-rosette-forming cells while high affinity E-rosettes (active or early rosettes) increase. The author speculates that this differential age effect may reflect the abnormal capping behaviour of E-rosettes or a change in the cell surface charge properties. A type II error is a common trait of the reviewed studies and could well explain the great number of reports concluding that E-rosette-forming cells are unaltered in the elderly.

Adult↗
PubMed1988

Ultrastructure of human E-rosettes: a re-examination.

In contrast with previous published studies, it has been found that T-lymphocytes interact through broad-base contacts with sheep erythrocytes (SRBC) in E-rosettes. An electron dense material was spontaneously observed between the lymphocyte and erythrocyte plasma membranes. These findings fit more closely with the known metabolic effects of SRBC upon lymphocytes and the SRBC-capping phenomenon.

Animals↗
PubMed1987

Nifedipine-induced hyporeactivity in delayed hypersensitivity skin tests.

Four patients and three healthy volunteers were submitted to delayed hypersensitivity skin tests to candidin, tuberculin, streptokinase/streptodornase (SK/SD) and mumps antigen before and after a 1 week treatment with nifedipine 10 mg q. 8h. A decrease in the scores of induration and erythema was observed, especially in response to SK/SD antigen challenge. We conclude that nifedipine may induce an anergy status in delayed hypersensitivity skin tests.

Humans↗
PubMed1986

Effect of dipyridamole upon thymidine incorporation and capping in human lymphocytes.

Dipyridamole is a potent inhibitor of tritiated thymidine incorporation by PHA-stimulated human lymphocytes. This effect is unrelated to the length of culture, to the level of response in untreated cultures, or to the proliferative index. This suggests that dipyridamole principally effects the membrane transport of thymidine. Dipyridamole inhibits sheep-erythrocyte-capping by E-rosettes. This effect cannot be mimicked by theophylline or cyclic nucleotides and cannot be reverted by adenosine. Pharmacological studies with colchicine and cytochalasin B suggest interference with cytoskeletal functions, probably of microtubules. This could be another site of action of dipyridamole beyond phosphodiesterase inhibition and adenosine metabolism.

Dipyridamole↗
PubMed1986

Specific effect of age on lectin-induced mitogenesis of lymphocytes from diseased patients.

Using several models of multivariate analysis, it is found that age per se is a specific determinant on the in vitro lymphocyte response to phytohemagglutinin A in a random sample of 30 diseased patients. Depending upon the used model, sex and lymphocyte subsets appear as other significant variables. The multiple regression coefficients reach 0.85. A 2% fall per decade is expected for phytohemagglutinin A responsiveness expressed in 1n cpm.

Adolescent↗
PubMed1986

In vitro effects of flunarizine on human lymphocytes.

Flunarizine, a slow-channel calcium entry blocker used as a vasodilator, interferes in vitro with human lymphocyte functions. It prevents lymphocytes from capping sheep erythrocytes, an effect which is probably due to the disconnection of the membrane from its cytoskeletal control. Flunarizine antagonizes both colchicine and cytochalasin B effects upon capping. Although the mitogen-induced lymphocyte stimulation has been shown to be sensitive to calcium depletion or calcium entry blocking by Verapamil, an enhanced response to phytohaemagglutinin A was observed with flunarizine. This suggests a differential sensitivity of the lymphocytes to calcium-entry blockers.

Animals↗
PubMed1985

Sheep-erythrocyte-capping by human T-lymphocytes. Pharmacological inhibition by phenothiazine drugs.

In our previous studies it was found that E-rosette dissociation and sheep-erythrocyte capping were active processes involving the cytoskeleton. These cellular functions are now shown to be very sensitive to phenothiazine-drugs whose activities can be differentiated as follows: trifluoperazine greater than chlorpromazine greater than sulfoxide derivatives, suggesting a role for calmodulin-mediated events. These findings are in contradiction to prior reports pointing to the inefficacy of chlorpromazine to inhibit slow kinetic capping. However, no co-capping of trifluoperazine fluorescence (as a probe of calmodulin) and sheep erythrocytes could be observed. No requirement in extracellular calcium was evident for E-rosette formation and dissociation.

Adult↗
PubMed1984

High-output right ventricular failure secondary to hepatic arteriovenous microfistulae. Selective arterial embolization treatment.

A patient with diffuse hepatic arteriovenous microfistulae suffered from secondary high-output right ventricular failure, pulmonary hypertension, and ascites, all of which could be managed by selective embolization of the hepatic artery. The vascular lesion of the liver seems to be essential, although hemorrhagic hereditary telangiectasia , perhaps aggravated by administration of oral contraceptives, may be considered contributory factors in this case.

Arteriovenous Fistula↗
PubMed1983

Lymphocyte activation in human ageing: V. Acquisition of response to T cell growth factor and production of growth factors by mitogen-stimulated lymphocytes.

In order to ascertain why the T cell proliferative response declines with ageing, the age-related quality of the interleukin II (Il-2)-mediated signal during lymphocyte activation was investigated in mitogen-stimulated peripheral blood mononuclear cells (PBMC) from old (over 70 years) and adult (20-40 years) subjects. Both the Il-2 properties of supernatants produced by phytohaemagglutinin (PHA)-stimulated PBMC on Il-2 sensitive cells and the PHA-induced transformation in Il-2 sensitive T cells were decreased in the old subjects. Supplements with human Il-2 enhanced the DNA synthesis by PHA-, concanavalin-A-, or pokeweed-mitogen-activated lymphocytes in the two groups of subjects. The addition of Il-2 to old cultures restored a response similar to that observed in adults cells cultured without exogenous Il-2. The similarity of the dose-response curves to interleukin II indicated the unaltered affinity of the specific membrane receptors to the humoral factors. These findings strongly suggest that the immune deficiency commonly found in the elderly results principally from a selective alteration of the hormonal step of lymphocyte activation.

Adult↗