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Biomedical subjects

P Marin

Publications and source records attributed to P Marin.

At least 73 records · Page 4Linked to original sources
PubMed1991

Comparison of binding characteristics of endothelin receptors on subpopulations of astrocytes.

Astrocytes in primary culture originating from different brain areas of the mouse embryo (striatum, cerebral cortex and mesencephalon) were compared for their [125I]-Endothelin-1 (ET-1) binding characteristics, in terms of affinity, binding capacity and specificity. Our results indicate that astrocytes from mesencephalon express about twice as many receptors as astrocytes from striatum or cortex (149,000 +/- 9700 vs 63,700 +/- 5600 and 81,900 +/- 5300, respectively), with similar affinities. Specificity patterns for the various peptides of the endothelins/sarafotoxins family (ET-1, -2, -3; SRTXa, b, c) are comparable in the three subpopulations of astrocytes: ET-1, -2 and SRTXb exhibit higher affinities than SRTXa and SRTXc. In addition, ET-3 and SRTXc seem to discriminate between different subsets of [125I]-ET-1 binding sites in the three subpopulations.

Animals↗
PubMed1991

Are several G proteins involved in the different effects of endothelin-1 in mouse striatal astrocytes?

High-affinity specific receptors of endothelin (ET-1) were identified on primary cultures of mouse embryo striatal astrocytes by binding experiments performed with 125I-ET-1. Stimulation of production of inositol phosphates, a biphasic increase of the intracellular calcium concentration, and inhibition of cyclic AMP accumulation were observed in the same cells under ET-1 stimulation. Pretreatment of these cells with Bordetella pertussis toxin affected these effects to different extends, an observation suggesting that they are mediated by multiple transduction pathways, possibly involving several guanine nucleotide-binding proteins.

Animals↗
PubMed1991

Hypernatraemia in an adult in-patient population.

We report a retrospective study of hypernatraemia (serum sodium concentration greater than 150 mmol/l) in an adult in-patient population of a health district during one year. The incidence was 0.3% with at least 60% of cases developing after hospital admission, mainly in elderly patients. Dehydration appeared to be the major cause, with the use of diuretics, depressed conscious level or febrile illness implicated in a majority. Most patients had more than one contributory factor and iatrogenic causes were common. Associated illnesses were often severe and the in-hospital mortality was high (54%) regardless of age. Hypernatraemia in hospitalized patients should be largely avoidable and there is a need for greater awareness of the importance of active maintenance of hydration in susceptible patients.

Adult↗
PubMed1990

Establishment of permanent astroglial cell lines, able to differentiate in vitro, from transgenic mice carrying the polyoma virus large T gene: an alternative approach to brain cell immortalization.

Permanent untransformed cell lines have been established from the cerebral cortex of transgenic mice that carry the polyoma virus large T gene. The immortalized cells described here synthesize laminin and neural cell adhesion molecules and induce primary neurons to develop neuritic processes. As shown by immunofluorescence and immunoblotting assays, they begin to synthesize the glial fibrillary acidic protein (GFAP) after confluence. Double labelling experiments indicated that GFAP expression is reversibly correlated with the arrest of cell division. The present cells also display adrenergic, serotoninergic, and high levels of muscarinic receptors coupled to the phosphatidylinositol signalling pathway. Taken together, our data show that these cell lines constitute homogeneous cell material that has retained the main differentiative, functional, and growth properties of normal astrocytes. Therefore, such clonal untransformed cell lines should be useful for further molecular studies, addressing terminal differentiation of glial cells, glioneuronal interactions, and astroglial expression of receptors for neurotransmitters. Furthermore, we suggest that this approach of cell immortalization by the use of transgenic mice carrying a non-transforming oncogene might be extended to a variety of cell types.

Animals↗
PubMed1990

Immortalization of bipotential and plastic glio-neuronal precursor cells.

Permanent clonal cell lines from newborn mouse striatum have been established after transfer of the simian virus 40 large tumor oncogene by means of a retroviral vector. Some of the lines obtained displayed properties of bipotential and plastic glio-neuronal precursors. Depending on the culture conditions, these cells express either the glial fibrillary acidic protein or neurofilaments. In addition, the cells can display adrenergic, D1 and D2 dopaminergic, muscarinic, and 5-hydroxytryptamine type 2 serotoninergic receptors, which are coupled either to the adenylate cyclase or to the phosphatidylinositol signaling pathways. The panel of receptors for neurotransmitters exhibited by these lines closely resembles that of primary striatal neurons. Results suggest that plastic common precursors of astrocytes and neurons persist in the striatum at a late developmental stage. As these permanent cell lines constitute an unlimited source of homogenous cell material, we suggest that they should be useful for molecular and pharmacological studies on the mechanisms and regulation of signal transduction as well as the commitment, plasticity, and differentiation of neural cells.

Animals↗
PubMed1990

Alternaria infection in a patient receiving chemotherapy for lymphoma.

A 60-year-old man receiving chemotherapy for an intermediate-grade non-Hodgkin's lymphoma developed multiple papuloerythematous cutaneous lesions. Alternaria alternata was cultured from the lesions, and hyphae were seen in biopsy specimens. This is an unusual infection, without a well-established treatment, in patients with lymphoma. The use of amphotericin B resulted in cure.

Alternaria↗
PubMed1987

Heterogeneity of DNA ploidy in patients with undifferentiated carcinomas of the stomach.

DNA ploidy was determined by cytophotometric DNA analysis in 20 patients with undifferentiated carcinomas of the stomach with serosal invasion. Measurements of DNA content were performed in 100 cells each in intramucosal, submucosal, muscular, and subserosal parts of a tumor. According to dispersion on the DNA histogram, DNA ploidy patterns were divided into low and high ploidy groups. Fourteen tumors (70%) showed the same ploidy in every layer (homogeneous DNA ploidy), 13 (65%) were low ploidy and, 1 (5%) was high ploidy. Heterogeneity of DNA ploidy was observed in the remaining six tumors (30%), which showed low ploidy in the mucosa, but high ploidy was observed in one or two deeper layers. In the six with heterogeneous DNA ploidy, there was more frequent metastasis to the lymph nodes (100%) and to the peritoneum (67%) than those with homogeneous DNA ploidy (50% and 21%, respectively). Cytophotometric DNA analysis of cells of undifferentiated gastric tumors suggested that there may be behavioral changes, depending on the degree of penetration into the gastric wall.

Carcinoma↗
PubMed1987

Effects of irradiation on human platelets stored at 20 degrees C.

The morphologic and functional properties of platelets after irradiation with 2500 rads and storage, in first-generation containers, for 48 h in a liquid phase at 20 degrees C with continuous horizontal agitation have been analyzed and compared with a control group of the same platelets which were not irradiated. The preservation technique induced changes in the morphology and aggregation stimulated by ADP and collagen. However, no significant differences were found between the irradiated and non-irradiated groups. Irradiation is not a conditioning factor to add to the hazards of preserving platelets in a liquid phase.

Adenosine Diphosphate↗
PubMed1987

Adenocarcinoma in the upper third part of the stomach.

Two hundred and twenty-three patients who underwent gastrectomy for adenocarcinoma arising from the cardia and upper third part of the stomach were studied with regard to esophageal invasion. One hundred and twenty-seven (57 per cent) had a malignant invasion into the esophagus and 96 (43 per cent) did not. In the curative instances, 52 of 74 patients (70.3 per cent) without esophageal invasion survived for five years, while 14 of 52 patients (26.9 per cent) with esophageal invasion survived: The prognosis of patients with esophageal invasion was poor regardless of the presence or absence of metastases to the lymph nodes. No patient who underwent noncurative resection survived for five years. To elucidate the high risk factors of esophageal invasion, a proportion of patients with esophageal invasion was statistically compared with patients without esophageal invasion, according to clinicopathologic factors. High risk factors included anatomic location, advanced disease and Borrmann IV type in gross appearance, more than 5 centimeters in diameter, positive serosal in filtration and positive metastases to the lymph nodes. Histologic type and mode of invasion did not relate to the esophageal invasion. The patients with high risk factors had a significantly poorer prognosis than did those without high risk factors. The results of the present study clearly show that high risk factors for esophageal invasion have an untoward effect on the rate of curative resection and the prognosis after removal of a lesion from the upper third part of the stomach.

Adenocarcinoma↗
PubMed1986

[Effect of T-cell depletion of the graft on graft survival and graft vs host disease].

A limiting dilution culture method has been developed which allows the detection of small numbers of residual marrow T cells following their depletion with the monoclonal antibody Campath-I and autologous complement. In seven consecutive patients the degree of T cell depletion obtained was 1.82 (1.27-2.82) log. The number of nucleated cells per kg decreased by 50% and the number of CFU-GM per kg decreased by 60%. In all except one case marrow cellularity was found to be satisfactory 3 weeks after the transplant. Peripheral engraftment of granulocytes (greater than 500/mm3 on day 20, greater than 1000/mm3 on day 27), lymphocytes (greater than 500 on day 39, greater than 1000 on day 66), platelets (greater than 20,000 and self-sustained after day 24) and red blood cells (day to last infusion = 19) indicated a delay in recovery of lymphocytes and possibly granulocytes, but not platelets or red blood cells, compared to the engraftment seen in non-T depleted patients. No correlation between nucleated cells infused, GFU-GM and engraftment was found. However, the extent of T cell depletion apparently affects lymphocyte, and possibly granulocyte, recovery. The delay in lymphoid engraftment is also reflected by nonresponsiveness to alloantigens during the first 6-9 months following marrow grafting in the absence of graft vs. host disease.

Graft Survival↗
PubMed1984

[Intestinal absorption of iron. Mechanism and interactions].

The mechanism and the regulation of intestinal iron absorption are described. Iron absorption is enhanced from animal foods, whereas it is reduced from vegetable foods. These data can be useful in the treatment of iron deficiency and iron overload.

Dietary Proteins↗
PubMed1981

Prognosis in acquired aplastic anaemia. A multivariate statistical analysis of 80 cases.

Prognostic factors were studied in a series of 80 patients with aplastic anaemia. The most important and easily obtainable individual variables, isolated in a previous univariate statistical analysis, were placed in a linear logistic regression model. A prognostic formula was derived containing the following 4 variables, in decreasing order of significance: (1) reticulocytes, (2) interval from onset of symptoms to first visit, (3) mean red cell volume, and (4) platelets. The prognostic formula permits an estimate of the probability of death within 3 months from the first visit. Its usefulness in several clinical situations, especially those related to bone marrow transplantation, is illustrated.

Adolescent↗
PubMed1980

Effect of mannitol on acute amphotericin B nephrotoxicity.

This study was undertaken to examine the value of mannitol as protection against the acute nephrotoxicity of amphotericin B under controlled conditions in a reproducible model of toxicity in the dog. Eleven dogs received amphotericin B, 2.5 mg x kg-1 b. wt. by i.v. infusion over a 4-h period. Six dogs were treated with mannitol, 6.25 g, i.v. every hour and five served as controls. Urinary volume (V), inulin clearance (CIn), p-aminohippurate clearance (CPAH), and Na excretion (UNaV) were measured every hour throughout the experiment. Although a higher urinary output was maintained in mannitol-treated dogs, a progressive decline in renal function was observed in treated and in control dogs. During the 4th h, mannitol-treated dogs showed higher CIn (37.4 vs. 19.7 ml x min-1 and CPAH (95 vs. 54 ml x min-1 than controls. However, statistically the differences were barely significant. The results fail to show that mannitol offers a definite protection against amphotericin B nephrotoxicity.

Amphotericin B↗