Publications (4)8.15 Total impact
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Article: Resveratrol prevents global cerebral ischemia-induced decrease in lipid content.
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ABSTRACT: The present study was undertaken to evaluate whether resveratrol (RSV) modulates membrane lipid composition, as well as on ganglioside profile in ischemia/reperfusion injury. Global cerebral ischemia was induced by four-vessel occlusion for 10 minutes. RSV (30 mg/kg) or vehicle was intraperitoneally administered to rats 7 days prior to ischemia. Brain structures were homogenized with chloroform/methanol for ganglioside, phospholipids, and cholesterol levels. RSV significantly prevented the reduction in the total content of gangliosides, phospholipids, and cholesterol in hippocampi and cerebral cortex induced by global cerebral ischemia. Although ischemia/reperfusion decreased ganglioside content, the ganglioside profiles were apparently not modified. Our experiments suggest that lipid metabolism is important for development of ischemic damage and indicate that RSV treatment 7 days prior to ischemia may prevent membrane lipid loss.Neurological Research 01/2013; 35(1):59-64. · 1.52 Impact Factor -
Article: Immunohistochemical localization of an N-acetyl amino-carbohydrate specific lectin (ACL-I) of the marine sponge Axinella corrugata.
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ABSTRACT: The N-acetyl amino-carbohydrate specific lectin (ACL-I) was previously identified and purified by us from the marine sponge Axinella corrugata (phylum Porifera, class Demospongiae). The distribution of the specific lectin within the tissue of the sponge was studied by bright-field optical microscopy immunohistochemistry in order to better understand its physiological role in the sponge. Polyclonal antibodies were raised against purified ACL-I in mice and tested by Western blot technique. The immunohistochemical analysis of ACL-I in cross sections of A. corrugata showed that this lectin is found inside the denominated spherulous cells, which contain vesicles that store the lectin. Some evidence is shown that ACL-I might also be present in the extracellular matrix. It was not possible to demonstrate by the immunohistochemical technique if ACL-I is colocalized in both the plasma membrane and in the cytoplasm of the spherulous cells.Acta histochemica 10/2011; 113(6):671-4. · 1.23 Impact Factor -
Article: Amyloid-β induced toxicity involves ganglioside expression and is sensitive to GM1 neuroprotective action.
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ABSTRACT: The effect of Aβ25-35 peptide, in its fibrillar and non-fibrillar forms, on ganglioside expression in organotypic hippocampal slice cultures was investigated. Gangliosides were endogenously labeled with D-[1-C(14)] galactose and results showed that Aβ25-35 affected ganglioside expression, depending on the peptide aggregation state, that is, fibrillar Aβ25-35 caused an increase in GM3 labeling and a reduction in GD1b labeling, whereas the non-fibrillar form was able to enhance GM1 expression. Interestingly, GM1 exhibited a neuroprotective effect in this organotypic model, since pre-treatment of the hippocampal slices with GM1 10 μM was able to prevent the toxicity triggered by the fibrillar Aβ25-35, when measured by propidium iodide uptake protocol. With the purpose of further investigating a possible mechanism of action, we analyzed the effect of GM1 treatment (1, 6, 12 and 24h) upon the Aβ-induced alterations on GSK3β dephosphorylation/activation state. Results demonstrated an important effect after 24-h incubation, with GM1 preventing the Aβ-induced dephosphorylation (activation) of GSK3β, a signaling pathway involved in apoptosis triggering and neuronal death in models of Alzheimer's disease. Taken together, present results provide a new and important support for ganglioside participation in development of Alzheimer's disease experimental models and suggest a protective role for GM1 in Aβ-induced toxicity. This may be useful for designing new therapeutic strategies for Alzheimer's treatment.Neurochemistry International 06/2011; 59(5):648-55. · 2.86 Impact Factor -
Article: Steroid 5-alpha reductase type 2 activity in biopsies from malignant and normal prostatic tissues.
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ABSTRACT: The conversion of testosterone (T) to the more potent metabolite dihydrotestosterone (DHT) by prostate-specific steroid 5 alpha-reductase isoenzymes is a key mechanism in the action of androgens in the prostate and it is important in the promotion and progression of prostate diseases. We described an adaptation of a sensitive method for evaluation of the 5 alpha-reductase type 2 (5 alpha-R2) activity using a small quantity of protein. We used 29 human prostate transrectal ultrasound-guided core biopsies obtained from patients (median age 70, range 55-86 y) undergoing this procedure for diagnostic purposes. 4-[(14)C]testosterone and NADPH were incubated with biopsy homogenate. Reaction products were extracted, separated by thin layer chromatography and revealed by autoradiography. Areas correspondent to T and DHT were scraped into vials and their radioactivity determined. The 5 alpha-R2 activity was expressed as ln (natural logarithm). The assay was validated according to the protein concentration and incubation time linearities. The 5 alpha-R2 activity showed a significant difference between normal and neoplastic tissues with significance level set at P<0.05, mainly in the left prostate lobe. This was independent from the PSA levels. Determination of 5 alpha-R2 activity, using the conditions reported herein, could be utilized as an efficient biochemical parameter of prostate neoplastic processes.Clinica Chimica Acta 06/2008; 391(1-2):36-40. · 2.54 Impact Factor
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2008
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Hospital De Clínicas De Porto Alegre
Porto Alegre, Estado do Rio Grande do Sul, Brazil
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