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Biomedical subjects

G Ortega

Publications and source records attributed to G Ortega.

At least 19 recordsLinked to original sources
PubMed1992

Inhibition of ferrous-induced lipid peroxidation by pyrimido-pyrimidine derivatives in human liver membranes.

The effects of pyrimido-pyrimidine derivatives (dipyridamole, RA-642, and RA-233) on lipid peroxidation, using d-alpha-tocopherol as standard, were studied in enriched membrane fractions from human and rat hepatocytes. Equimolar concentrations of ferrous sulfate and ascorbic acid were used to induce lipid peroxidation. The amount of peroxidized lipids observed in membrane fractions from human liver was smaller than in those from rat liver. In both species, however, pyrimido-pyrimidine derivatives, except for RA-233 in rat liver, inhibited lipid peroxidation dose-dependently in the following sequence: RA-642 greater than dipyridamole greater than d-alpha-tocopherol RA-233.

Animals↗
PubMed1992

Effect of zeitgeber intensity reduction on a simulated dual-oscillator human circadian system: classical and dynamic analysis.

The two-oscillator model of human circadian rhythmicity was analyzed when a zeitgeber relative intensity of 1, 0.5, or 0.1 was introduced into the equations. Fourier analysis was compared with dynamic analysis such as attractor reconstruction or Liapunov exponent calculation. After a 50 or 90% reduction in zeitgeber intensity, the dynamics of the system became equivalent and differed significantly from those of a system with maximal zeitgeber intensity. When 10% aleatory noise was added to the data, the analysis was still applicable, and the results obtained were essentially the same as in the absence of noise. Dynamic analysis could thus provide a distinct classification for periodic data, based on the type of analysis.

Biometry↗
PubMed1992

[Characterization of Paracoccidioides brasiliensis antigens. Serological immunodiagnosis using western blotting].

The electrophoretic characterization on SDS-PAGE gels of Paracoccidioides brasiliensis antigens, strains 2511 and 6688; and the additional use of immunoblotting has permitted in this study to identify the immunogenic, sensitive and specific antigen fractions for the diagnosis of Paracoccidioidomycosis. The antigenic preparations showed differences depending on the morphologic form of the fungus and the method utilized. The procedure revealed heterogeneity in the humoral immune response of the patients studied and permitted us to establish indices of activity of Paracoccidioidomycosis by the sequential analysis of sera obtained during different stages of the disease. The high sensitivity of this method makes it useful as an additional technique for the serologic immunodiagnosis of Paracoccidioidomycosis.

Antibodies, Fungal↗
PubMed1992

[Carotenodermia].

Explore the source record for details and available documents.

Adolescent↗
PubMed1992

[Non-specific digestive ulcers and Behçet's disease].

We present a 56-year-old patient with episodes of recurrent abdominal pain and constitutional syndrome, whose evolution was complicated by mucous ulcers in mouth, esophagus, anus and ileocecal valve, as well as occasional aphthae in scrotum. All these clinical signs are compatible with a Behçet's disease with relevant digestive manifestations.

Abdominal Pain↗
PubMed1992

[Treatment of arterial hypertension with captopril in lupus nephropathy].

We present a non-controlled prospective study of 10 hypertensive patients with systemic erythematous lupus and nephropathy, treated with captopril exclusively or combined with other drugs, in order to assess its effectivity and potential side effects. Four of these 10 patients had mild hypertension; 3, moderate hypertension and 3, severe hypertension. In 5 of them, arterial pressures was controlled with just captopril; in other 3, we added furosemide and in one patient, we added furosemide and nifedipine. In one case, hypertension was not controlled. Renal function remained stable and proteinuria improved in six patients. Three patients presented reversible agranulocytosis, during or immediately after treatment. One of them was treated two years after with enalapril, without observing hematologic recurrence. We conclude that captopril is useful in treating arterial hypertension associated to lupous nephropathy, but frequent leukocyte counting controls must be done during the first months.

Adolescent↗
PubMed1991

[Production of monoclonal antibodies against Leishmania mexicana mexicana antigens].

In the present work we obtained three mAbs specific against gp65 of the strain L. mexicana mexicana (NR). These three mAbs were able of recognizing promastigotes of L.m.m. not only for immunofluorescence but also by immunostain. In the immunohistochemistry of biopsies of patients with leishmaniasis, using the three mAbs, it was possible to observe the presence of amastigotes in the infected tissues.

Animals↗