Biomedical subjects

E Diez

Publications and source records attributed to E Diez.

At least 73 records · Page 4Linked to original sources

PubMed1987

Ethanol induces release of arachidonic acid but not synthesis of eicosanoids in mouse peritoneal macrophages.

Exposure of mouse peritoneal macrophages to ethanol induces a rapid release of arachidonic acid to the extracellular medium. All major classes of phospholipids, phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol contribute to this release. Ethanol-induced mobilization of arachidonic acid occurs by deacylation, but it is not accompanied by eicosanoid synthesis. These data suggest that at least two signals are necessary for the release and metabolism of arachidonic acid. Ethanol also activates a phospholipase C which hydrolyzes only phosphatidylinositol, and not its phosphorylated derivatives.

Animals↗

PubMed1987

Effect of ethanol on the arachidonic acid metabolism in mouse peritoneal macrophages.

Macrophages play an important role in the development of chronic inflammatory states. Ethanol has been shown to impair a number of membrane-linked phenomena. The synthesis and secretion of oxygenated metabolites of arachidonic acid is triggered at the cytoplasma membrane level. The present study was carried out in order to investigate the effect of ethanol on the arachidonic acid metabolism in mouse peritoneal macrophages. Two types of experiments were performed: with endogenous radiolabeled arachidonic acid and with exogenously added radiolabeled arachidonic acid. Our data show that ethanol in vitro activates the release of arachidonic acid from intracellular pools, while the proportion of endogenous substrate metabolized in the presence of ethanol is similar to that in controls. From the exogenous it seems clear that ethanol induces different effects depending whether the arachidonic acid is endogenous or added exogenously.

Animals↗

PubMed1987

Cytogenetics of Abelson virus-induced malignant lymphoma cell lines in the mouse.

Cytogenetic studies were performed on 11 established murine thymoma or peripheral lymphoma cell lines induced by a thymotropic Abelson virus. In eight cell lines a trisomy 5 was present, whereas, two cell lines had a normal karyotype like fresh tumor cells. In the last cell line a trisomy 11 resulting from a t(5;11) was observed. The origin of this nonrandom chromosome abnormality is briefly discussed.

Abelson murine leukemia virus↗

PubMed1987

Ontogeny and tissue distribution of the chicken Bu-1a antigen.

By using a sensitive technique of immunofluorescence on polyethylene glycol-embedded tissue sections, we could better determine the distribution of L22+ cells in embryonic and adult chickens. L22 mAb was originally described as reacting with bursa and bursa-derived lymphocytes. We now present evidence to suggest that this mAb also reacts with a subset of macrophages found in bursa, thymus, spleen, liver, intestine and peritoneum. The L22+ cells appear early during embryonic life, simultaneously in yolk sac, bursa, thymus, spleen and bone marrow. At all steps of their ontogeny, thymocytes were L22-, while most, if not all, bursal lymphoid cells were L22+. Moreover, L22 antigen can be detected on haemopoietic cells probably precursors, before and during their entry into the bursal rudiment on Day 9 or 10 of embryonic life. We conclude from these data that L22 is not restricted to the B-cell lineage as it is shared with a subset of macrophages. Furthermore, our observations of L22+ cells during embryonic life favour the hypothesis of separate lineages for B-cell and T-cell precursors in chick embryo, which was previously put forward on the basis of different sets of experiments.

Animals↗

PubMed1986

Intracellular Ca2+ requirements for zymosan-stimulated phosphoinositide hydrolysis in mouse peritoneal macrophages.

The phosphatidylinositol cycle has been demonstrated to be involved in the control of Ca2+ cytosolic levels in several cellular types. The Ca2+ requirements of phospholipase C activity and the described stimulation of phosphoinositide hydrolysis by Ca2+ ionophores make unclear the relationship between phosphatidylinositol cycle and Ca2+ mobilization. The results reported here suggest that intracellular Ca2+ is necessary for zymosan-stimulated phospholipase C activation in macrophages.

Animals↗

PubMed1986

The bursal microenvironment: phenotypic characterization of the epithelial component of the bursa of Fabricius with the use of monoclonal antibodies.

Monoclonal antibodies were raised against newborn chick bursa of Fabricius, and here we describe two antibodies, BEP-1 and BEP-2, which react selectively with the epithelial component of the bursa of Fabricius. In previous studies, using quail chick chimeric bursas, we have demonstrated that the epithelium of the bursal rudiment, presumably of endodermal origin, gives rise to the epithelium lining the bursal lumen, the basement membrane-associated epithelium and the network of reticular cells of the medulla, while the interfollicular connective cells are derived from the mesoderm. When tested in indirect immunofluorescence assay on bursa tissue sections or cell suspensions, BEP-1 reacts with a surface antigen present on all the epithelial cells of the bursa and could be used as a marker for this cell lineage. BEP-2 binds to an intracytoplasmic antigen that is present in about 5% of cells, representing the epithelial cells, and which is excreted in the medulla. BEP-2 also reacts with the epithelial cells of the thymic medulla and with the mucin-secreting goblet cells of the intestinal villi. A rabbit antiserum raised against human cytokeratin gives a different pattern of reactivity on bursal tissue compared to BEP-1 and BEP-2, tentatively suggesting that these two antibodies do not bind to keratin-like molecules. During ontogeny, BEP-1 reactivity appears in bursal epithelium from the early stages of bursal ontogeny (8 days). BEP-2 reactivity is detected around hatching time. BEP-1 and BEP-2 do not show any antigenic heterogeneity among the epithelial cells of the bursa.

Aging↗

PubMed1985

Tissue distribution and ontogenic appearance of a chicken T lymphocyte differentiation marker.

A monoclonal antibody, designated T10A6, was produced by immunizing mice with H.B14 chicken thymocytes. T10A6, when tested by immunofluorescence, labeled 80% of thymocytes, and a subset of peripheral T cells: 20% of spleen leukocytes, 10% of blood leukocytes, 8% of bone marrow cells but less than 1% of bursal lymphocytes. Tissue distribution on polyethylene glycol sections showed that in the thymus T10A6 stained most cortical thymocytes and a portion of medullary cells. In the spleen, the positive cells appeared scattered mainly in the T-dependent areas. Ontogenic studies revealed that the antigen recognized was found in the chick embryo thymus from day 11 onward and the expression of this antigen on thymocytes reached the adult level from day 13. The first positive cells were detected in the spleen on day 13 of embryonic life. T10A6 (IgG1) precipitated a 65-kDa material from thymocytes. This is the first description of a monoclonal antibody recognizing a peripheral T cell subpopulation in chicken.

Animals↗

PubMed1985

Evaluation of the efficacy of oral methotrexate in the prevention of recurrence of superficial bladder tumours.

Twenty-four patients with previously untreated T1 transitional cell carcinoma of the bladder were treated with oral methotrexate 50 mg weekly for 18 months. Thirteen developed tumour recurrences (recurrence index 11 per 100 patient months at risk) and in one-third of the patients treatment was stopped because of unwanted side effects. These results are no better than our previous experience with intravesical Adriamycin, thiotepa or cisplatin.

Administration, Oral↗

PubMed1984

The fluidity of plasma membranes from ethanol-treated rat liver.

Male Wistar rats were maintained for 35-40 days on a liquid diet containing 36% of calories as ethanol. Ethanol was replaced by carbohydrates in the isocaloric diet fed to control animals. The effect of ethanol consumption has been studied on the fluorescence polarization of rat liver plasma membranes and artificial lipid vesicles and on the lipid composition of the membranes. Fluorescence polarization in both membranes and vesicles was determined using DPH and TMA-DPH as fluorescence markers; from these data, the polarization term (ro/r-l)-1 and flow activation energy (delta E) were calculated. The ethanol consumption induces a more fluid environment within the membrane core of liver plasma membranes; the ethanol-fed rat membranes are more resistant to the in vitro effect of ethanol disordering the membrane structure. Vesicles obtained with lipids from either control membranes or ethanol-fed rat membranes were treated with ethanol and the changes in polarization paralleled to those exhibited by the membranes. The absence of phase transitions and of delta E changes was also shown in temperature-dependence studies. The lower cholesterol content found in ethanol-fed rat plasma membranes might be responsible for observed variations in the microviscosity.

Animals↗

PubMed1981