953 resultados para Human mesenchymal stem cells
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The incidence of apoptosis and nuclear instability, including the incidence of catastrophic death, were investigated in benzo[a]pyrene (BP)-transformed human breast epithelial cells (BP1-E cell line) after microcell-mediated transfer of chromosomes 11 and 17. Since the introduction of normal chromosomes 11 and 17 into tumorigenic human breast BP1-E cells reverts some of these cells' characteristics (especially those affected by microsatellite instabilities and loss of heterozygosity) those of parental non-transformed MCF-10F cells, it was expected that the cell death rates would also be affected by this treatment. The transfer of the mentioned chromosomes, especially chromosome 17, to tumorigenic BP1-E cells increased the apoptotic ratios and decreased the nuclear instability ratios, thus showing that the microsatellite instability and loss of heterozygosity induced by BP in these chromosomes of MCF-10F cells affect the control of cell death mechanisms. (C) 2003 Elsevier B.V. All rights reserved.
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Pristimerin has been shown to be cytotoxic to several cancer cell lines. In the present work, the cytotoxicity of pristimerin was evaluated in human tumor cell lines and in human peripheral blood mononuclear cells (PBMC). This work also examined the effects of pristimerin (0.4; 0.8 and 1.7 mu M) in HL-60 cells, after 6, 12 and 24 h of exposure. Pristimerin reduced the number of viable cells and increased number of non-viable cells in a concentration-dependent manner by tripan blue test showing morphological changes consistent with apoptosis. Nevertheless, pristimerin was not selective to cancer cells, since it inhibited PBMC proliferation with an IC50 of 0.88 PM. DNA synthesis inhibition assessed by 5-bromo-2'-deoxyuridine (BrdU) incorporation in HL-60 cells was 70% and 83% for the concentrations of 0.4 and 0.8 mu M, respectively. Pristimerin (10 and 20 mu M) was not able to inhibit topoisomerase 1. In AO/EB (acridine orange/ethidium bromide) staining, all tested concentrations reduced the number of HL-60 viable cells, with the occurrence of necrosis and apoptosis in a concentration-dependent manner, results in agreement with trypan blue exclusion findings. The analysis of membrane integrity and internucleosomal DNA fragmentation by flow cytometry in the presence of pristimerin indicated that treated cells underwent apoptosis. The present data point to the importance of pristimerin as representative of an emerging class of potential anticancer chemicals, exhibiting an antiproliferative effect by inhibiting DNA synthesis and triggering apoptosis. (c) 2008 Elsevier Ltd. All rights reserved.
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Several components of the erythrocyte-dependent glutathione redox system (reduced glutathione, GSH; oxidized glutathione, GSSG; glutathione peroxidase, GSH-Px; glutathione reductase, GSH-Red) were determined in patients with types I and II diabetes mellitus (DM). All groups studied were male subjects: G1, 20 young healthy individuals (aged 23.7 +/- 4.2 years); G2, 15 young insulin-treated type I DM patients; G3, 20 older insulin-treated type II DM patients; 04, 21 older oral hypoglycemic agent-treated type II DM patients; G5, 28 aged healthy individuals (aged 68.9 +/- 11.5 years). There were no differences between G1 and G2, G3 or G4 regarding erythrocyte GSH, GSSG, and GSH-Red (without FAD) levels. GSH-Px activity was significantly lower in G2 when compared to G1 (15.2 +/- 4.9 vs 20.6 +/- 6.6 IU/g Hb). The GSH-Red and GSH-Px activities and GSH levels were significantly higher in 03 (4.6 +/- 1.7 IU/g Hb, 20.2 +/- 8.7 IU/g Hb and 3.5 +/- 1.3-mu-M/g Hb) and G4 (5.0 +/- 2.2 IU/g Hb, 16.9 +/- 6.1 IU/g Hb and 5.0 +/- 2.3-mu-M/g Hb) when compared to G5 (3.4 +/- 0.9 IU/g Hb, 12.0 +/- 3.6 IU/g Hb and 2.3 +/- 0.9-mu-M/g Hb). The findings suggest that treatment of DM can stimulate the redox activity of red blood cells in aged subjects.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Prostatic lesions in Brazilian patients with benign prostatic hyperplasia (BPH, 26 cases) or adenocarcinoma (AC, 25 cases) were compared by qualitative microscopy and morphometric analysis. In 12 cases of BPH, prostate regions with no histological alterations were considered as controls (Ct). Archival material consisted of formalin-fixed, paraffin-embedded specimens obtained from prostatic transurethral resection and radical prostatectomy. Haematoxylin/eosin (HE)-stained sections were used to estimate the nuclear areas, perimeters and form factor values. HE-stained sections from AC specimens were also used for Gleason grading. BPH, AC and Ct could be discriminated by their nuclear areas and nuclear perimeters, but not by the nuclear form factor parameter. No significant differences were found when the AC data were compared using the combined version or the predominant grade version of the Gleason score (p = 0.8380 for nuclear area; p = 0.6076 for nuclear perimeter; p = 0.9202 for nuclear form factor; n = 200 nuclei per patient). This finding indicates that there is extensive heterogeneity in the size and shape of the nucleus in AC cells. These results also show that although the nuclear morphometry served to discriminate BPH and AC from each other and from Ct, it was not sufficient to correlate AC lesions with their respective Gleason scores in the human population analyzed.