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Biomedical subjects

D Olive

Publications and source records attributed to D Olive.

At least 217 records · Page 12Linked to original sources
PubMed1986

Modulation of surface T11 molecules induced by monoclonal antibodies: analysis of the functional relationship between antigen-dependent and antigen-independent pathways of human T cell activation.

Previous data indicated that T lymphocyte activation can be achieved by using a combination of anti-T11 monoclonal antibodies (mAb) directed to the "T11(2)" and the "T11(3)" epitopes, respectively. Unlike the T cell activation induced by antibodies directed to the T3-T cell receptor (Ti) complex or to T44 molecules, the anti-T11 mAb-induced cell activation was not accompanied by surface modulation of the T11 antigen. In the present study we show that appropriate stimulatory combinations of anti-T11 mAb are able to induce T11 antigen modulation in a variety of T cells including polyclonal peripheral blood populations, normal as well as leukemic (JA3) T cell clones. The first anti-T11 mAb combination leading to both cell activation and T11 antigen modulation was given by a mAb directed to the T11(2) epitope and by another mAb recognizing an epitope belonging to the T11(1) group. The second combination was given by two mAb directed against two different determinants of the T11(1) group. The ability to induce T11 antigen modulation allowed a more precise analysis of the pathway of T cell activation initiated by T11 molecules and its physical and functional relationship with the other known pathways of T cell activation. T cells following T11 antigen modulation failed to respond to subsequent stimulation with anti-T11 mAb. The refractory period lasted for 48-72 h and the restoration of the responsiveness to anti-T11 mAb coincided with the re-expression of T11 molecules at the cell surface. Modulation of T11 antigen did not affect the surface expression of T3, Ti or T44 molecules, in addition, "modulated" cells maintained their ability to respond to mAb directed against T3, Ti or T44 molecules. On the contrary, antibody-induced modulation of the T3-Ti receptor complex abrogated both T11- and T44-dependent T cell activation. Finally, antibody-induced modulation of T44 antigen did not inhibit either the T11- or the T3-Ti-dependent pathway of T cell activation. These data indicate that down-regulation of the pathway of T cell activation initiated by T11 molecules can be induced not only by modulation of the antigen receptor complex but also by appropriate mAb to T11 molecules and, presumably, by the natural ligand binding to T11 molecules.

Antibodies, Monoclonal↗
PubMed1986

Different human B cell subsets respond to interleukin 2 and to a high molecular weight B cell growth factor (BCGF).

After activation by anti-mu antibody human B cells acquire the ability to proliferate in the presence of recombinant interleukin 2 (IL 2), a 20-kDa mol. mass B cell growth factor (BCGF) and a high mol. mass BCGF (50-kDa BCGF). An anti-IL 2 receptor (IL 2R) monoclonal antibody inhibits the IL 2-dependent proliferation without affecting that induced by BCGF. B cells expressing the IL 2R after anti-mu antibody activation (IL 2R+ cells) were separated from those not expressing IL 2R (IL 2R- cells). IL 2 stimulated the proliferation of only IL 2R+ cells whereas the 20-kDa BCGF acted on both IL 2R+ and IL 2R- cells. Importantly, the 50-kDa BCGF supported the proliferation of IL 2R- cells whereas it was inactive on IL 2R+ cells. Thus, the B cell subset responding to the 50-kDa BCGF after anti-mu antibody activation is distinct from that responding to IL 2.

Antibodies, Monoclonal↗
PubMed1986

Signal transducing mechanisms involved in human T cell activation via surface T44 molecules. Comparison with signals transduced via the T cell receptor complex.

Antibodies against the T44 surface molecule have been shown to activate human T cells to produce interleukin 2. The role of Ca2+ in the triggering of the interleukin 2-producing Jurkat T cell line by anti-T44 monoclonal antibody has been investigated. We show that activation is initiated by an increase in the concentration of free cytoplasmic calcium ions [Ca2+]i. Subsequently, we have investigated the mechanism by which perturbation of T44 molecules induces increases of [Ca2+]i in Jurkat cells. We show that the anti-T44-mediated increase in [Ca2+]i can occur only in presence of extracellular Ca2+, since no increment is detectable when extracellular Ca2+ is depleted by EGTA. Thus, it appears that perturbation of T44 molecules, unlike that of T3-Ti antigen receptor complex, fails to mobilize Ca2+ from intracellular stores. As inositol triphosphate is considered the putative mobilizer of Ca2+ from internal stores, we measured the levels of inositol triphosphate and of the other inositol phosphate compounds in Jurkat cells after stimulation with anti-T44 antibodies. In contrast to the stimulation via the T3-Ti antigen receptor complex, stimulation via T44 molecule does not induce increments of all three inositol phosphates. Taken together, these data indicate that stimulation mediated by the T44 molecule proceeds via a mechanism independent from the typical inositol lipid metabolism which does not involve mobilization of Ca2+ from internal stores.

Antibodies, Monoclonal↗
PubMed1986

Pulmonary sequestrations of the upper lobe in children: three presentations.

Pulmonary sequestrations are congenital abnormalities where nonfunctioning lung tissue receives its vascular supply from the systemic circulation (thoracic or abdominal aorta). It is necessary to establish the diagnosis in childhood when the lesions are uncomplicated. The authors present three cases of sequestration of the apex (2 extralobar and 1 atypical) with the main clinical and radiological features. Sequestrations in the upper lobe are rare, and the usual site is the left lower lobe. Plain x-rays show a dense opacity, sometimes air-filled and sometimes with an air-fluid level: angiography is currently the best mean for definitive diagnosis; however, computed tomography will probably be very useful in the future. Differential diagnosis includes tumours of the superior mediastinum (neurogenic tumours, digestive duplication, bronchogenic cysts, pheochromocytoma and hydatid cysts).

Angiography↗
PubMed1986

Identification of an early expressed marker of the luminal membrane of rabbit small intestinal columnar cells. Presence of a homologous antigen in kidney proximal tubules and glomeruli.

Four monoclonal antibodies have been produced that specifically react with a rabbit intestinal brush-border glycoprotein which migrates in SDS-polyacrylamide gel electrophoresis as a protein of molecular weight 140,000. Contrarily to brush-border hydrolases, it is expressed in poorly differentiated crypt cells of the small intestine. Absent from colon columnar cells, it can be considered to be an early marker of differentiation of absorbing cells of the small intestine. Immunofluorescence technique showed the presence of a homologous antigen in kidney proximal tubule brush-border and podocytes of kidney glomeruli.

Animals↗
PubMed1986

Expression of Tac antigen in B cell lymphomas.

In a series of 55 cases of B cell derived non-Hodgkin's lymphoma the reactivity of two distinct anti-Tac monoclonal antibodies was examined using a sensitive immunoperoxidase technique on cryostat sections. Eighteen out of the thirty-five cases of B cell lymphomas of low or intermediate grade of malignancy were found to be reactive while six out of 20 cases of high-grade malignancy lymphomas showed a positive immunostaining. No correlation was found between anti-Tac reactivity and surface immunoglobulin phenotype, T65 antigen, or calla expression. These findings showed that IL2 receptor expression is not restricted to activated T cells, and raise the question of the possible role of IL2 in the regulation of malignant B cell clone expansion.

Antigens, Neoplasm↗
PubMed1986

[Pleural involvement caused by contiguity or metastases in primary malignant bone tumors in children].

Pleural location of primary osseous malignant tumors of children are infrequent. They may be secondary from a distant primary osteosarcoma. It is necessary to investigate them via conventional chest X-ray followed by a CT of the thorax. This examination shows the pleural lesion, its limits and calcifications. It must be remembered that this examination doesn't always confirm the pleural location of the lesions, the angle that they subtend is not an accurate guide. Comparison with clinical data is essential in difficult cases.

Adolescent↗
PubMed1986

[Arterial hypertension caused by extrinsic compression of the renal artery of tumor origin in a child].

Stenosis of the renal artery secondary to an extrinsic acquired compression of the renal artery because of a tumor is rare. We report two cases. The first case is a boy of 14 months with a large neurogenic tumor from the right renal plexus with compression of the right renal artery. The second case is a girl of 2 years which had a neuroblastoma displacing the right kidney. The right renal vessels were invaded by very calcified solid masses and the removal was very difficult. Arterial hypertension secondary to an acquired unilateral renal stenosis may be healed definitely thanks to surgery.

Adrenal Gland Neoplasms↗
PubMed1985

T-lymphocyte subpopulations identified by monoclonal antibodies after human bone-marrow transplantation.

Peripheral T-lymphocyte reconstitution after bone-marrow transplantation, 12 allogeneic and 13 autologous, was studied by indirect immunofluorescence assay using mouse monoclonal antibodies. Abnormal counts were detected in the two major sub-populations of T-cells i.e. helper and T cytotoxic-suppressor lymphocytes, defined by monoclonal antibodies (alpha Leu 3a and B 9.2), and in DR antigen-positive T-cells. The pattern of T-lymphocytes replenishment was identical for both types of transplant, and was not affected by Graft Versus Host disease (GVHD).

Antibodies, Monoclonal↗
PubMed1985

[Partial trisomy of chromosome 3 resulting from paternal translocation].

The authors report a case of a 3 year-old patient presenting with partial trisomy of the short arm of chromosome 3. According to 21 previously published cases, the main features characterizing this chromosomal abnormality which is mainly observed in males are: cranio-facial dysmorphy, cardiac and genito-urinary malformations, psychomotor retardation. Cytogenetic studies always show an inherited balanced translocation allowing a possible prenatal diagnosis.

Chromosome Aberrations↗