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Biomedical subjects

M Arias

Publications and source records attributed to M Arias.

At least 199 records · Page 11Linked to original sources
PubMed1986

Immunoglobulin-producing cells in IgA nephropathy.

The number of peripheral blood mononuclear cells (PBMC) producing IgA, IgG and IgM spontaneously, after in vitro polyclonal stimulation with pokeweek mitogen (PWM) and in response to autologous mixed lymphocyte reaction (AMLR), were determined by a protein A hemolytic plaque assay in 23 patients with IgA nephropathy confirmed by renal biopsies and in 24 normal controls. The geometric mean of circulating IgA-producing cells in Berger's disease (689 +/- 1.73 cells/10(6) PBMC) was increased when compared with the normal controls (332 X divided by 1.52 cells/10(6) PBMC; p less than 0.001). To a lesser degree, there was also an increase in the number of IgG-secreting cells (98 +/- 3.97 cells/10(6) PBMC vs. 38 +/- 2.90 cells/10(6) PBMC; p less than 0.05). After PWM stimulation, although the number of IgA-producing cells was increased in patients with IgA nephropathy, no significant differences were observed between the 2 groups. In response to AMLR, the number of IgA-secreting cells was significantly higher in the cases with Berger's disease (1,979 +/- 1.76 cells/10(6) non-T cells vs. 783 +/- 1.95 cells/10(6) non-T cells; p less than 0.001). Although it did not reach statistical significance, the patient group had also an increase in the number of IgG-producing cells (884 +/- 2.64 cells/10(6) non-T cells vs. 317 +/- 5.05 cells/10(6) non-T cells). These data support the existence of some abnormalities in the mechanisms regulating the synthesis of IgA in Berger's disease which might contribute to its pathogenesis.

Adolescent↗
PubMed1986

Differentiation of chick embryo cardiomyocytes in cellular cultures: influence of the neurogenic ectoderm.

The behaviour and differentiation of cultured precardiac cells in the presence of neurogenic cells were studied by means of light and electron microscopy. Inhibition of the process of cardiac differentiation may be due to cellular contact or some specific factor elaborated in the process of differentiation by the neurogenic cells. Differentiation of cardiomyocytes in vitro may be compatible with the presence and contact of neurogenic cells, since both cell populations appear in the same reaggregate. Diffused substances in the medium of the culture through neurogenic cells do not appear to produce any modifications in cardiac differentiation. These processes were examined and are discussed.

Animals↗
PubMed1986

Influence of dialysis membranes on the convective transport of middle molecules.

Ultrafiltrates from 10 patients in chronic maintenance hemodialysis (7 males and 3 females) were obtained simultaneously using three different membranes: cuprophan, polyacrilonitrile and polysulfone. Middle molecules (MM) chromatographic profiles and total MM amount were determined by gel chromatography and high performance liquid chromatography. The convective transport of MM was similar and not membrane related. Hemofiltration, a predominantly convective solute transfer procedure using high flux membranes such as polyacrilonitrile and polysulfone, in which large amounts of fluids have to be ultrafiltered, is an effective form of MM removal.

Acrylic Resins↗
PubMed1984

Thromboxane mediates the increase in alveolar surfactant pool induced by free fatty acid infusion in the rabbit.

Intravenous infusion of free fatty acid (FFA) produces pulmonary edema and an increase in the alveolar surfactant content of the rabbit. In order to identify a likely mediator of this lung response to FFA, we used inhibitors of cyclo-oxygenase (indomethacin, 15 mg X kg-1 i.v., or meclofenamate, 5 mg X kg-1 i.v.) and thromboxane synthetase inhibitors (imidazole, 50 mg X kg-1 i.v. or dazoxiben, 2 mg X kg-1 i.v.) which were administered before FFA, 20 mg X kg-1 X min-1 i.v., in four different experimental series (n = 54). Lung surfactant was measured in bronchial-alveolar lavage fluid by determining disaturated phosphatidylcholine (DSPC). Both kinds of inhibitors blocked the increase in FFA-induced DSPC. They increased the survival rate but they only slightly changed the post-FFA morphofunctional pulmonary alterations. We conclude that the increase in alveolar surfactant induced by FFA is likely mediated by thromboxane. This mediator would seem to play a minor role in the FFA-induced pulmonary edema observed.

Animals↗
PubMed1983

Increased IgA-producing cells in the blood of patients with active Henoch-Schönlein purpura.

Peripheral blood lymphocytes (PBL) producing IgA, IgM, and IgG, both spontaneously and after pokeweed mitogen stimulation in cell culture, were determined by a protein A hemolytic plaque assay in 20 children with active Henoch-Schönlein purpura (HSP), 42 with inactive disease, 22 normal controls of the same ages, and 18 children with upper respiratory tract infections (URTI). The geometric mean of circulating IgA-producing cells in active HSP (1,016 X divided by 1.55 cells/10(6) PBL) was increased when compared with the group with inactive disease (P less than 0.001), normal controls (P less than 0.001), and children with URTI (542 X divided by 2.03 cells/10(6) PBL, P less than 0.05). The number of circulating IgM-producing cells was slightly increased in active HSP (260 X divided by 2.65 cells/10(6) PBL) and URTI (256 X divided by 3.16 cells/10(6) PBL). Both values were higher than those found in the group with inactive disease (113 X divided by 2.26 cells/10(6) PBL, P less than 0.01). There were no significant differences among the 4 groups in the number of circulating IgG-producing cells. The number of cells producing each type of immunoglobulin after in vitro stimulation with pokeweed mitogen was similar in patients with active HSP, normal controls, and the group with inactive disease. These data demonstrate a selective increase in the number of circulating IgA-producing cells only during disease activity, and add further support to a possible pathogenic role of this immunoglobulin in HSP.

Adolescent↗