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Biomedical subjects

G Nguyen

Publications and source records attributed to G Nguyen.

63 records · Page 4Linked to original sources

Effect of the nifedipine-atenolol association on arterial myocyte migration and proliferation.

The in vitro effect of nifedipine and atenolol, either alone or in combination, on the proliferation and migration of rat aortic smooth muscle cells was investigated. Nifedipine inhibited the replication of arterial myocytes in concentrations ranging between 10 and 100 microM. The inhibition, evaluated as cell number, was dose- and time-dependent with an IC50 of 39 and 34 microM after 48 and 72 h, respectively; the cell doubling time increased with drug concentrations up to 118 h versus 28 h for controls. Atenolol alone failed to reduce arterial myocyte proliferation, and did not influence the effect of nifedipine on cell proliferation. Nifedipine and atenolol alone inhibited in a dose-dependent manner rat aortic myocytes migration induced by fibrinogen as chemotactic agent. When the combination nifedipine-atenolol was investigated, an additive inhibitory effect on cell migration was observed. These results provide in vitro support for a potential effect of this drug association on early steps of atherogenesis.

Animals↗

Four cases of acute chagasic myocarditis in French Guiana.

The authors report four cases of acute chagasic myocarditis which had been diagnosed and treated in Cayenne, French Guiana, in the past 6 years. This French territory, which has the highest standard of living in South America, should be considered an area of risk for sporadic Chagas disease with epidemiologic features similar to those of the disease found in dense Amazon forest areas. Appropriate measures must be taken to screen and promptly manage Chagas disease in the French Guiana population.

Adult↗

[Beta-blockers and migraine. Efficacy of time-release propranolol versus placebo].

The efficacy and safety of long-acting propranolol (LA.P) 160 mg once-daily in the prophylactic treatment of migraine were tested against placebo in a multicentric, double-blind, randomized study comparing the two groups in a parallel manner over a treatment period of 12 weeks, and following a 4 week-placebo run-in period. Fifty-five out of the 74 patients who entered the trial included at the end of the run-in period. Forty-one patients completed the study. Out of the 14 patients who withdrew from the study, none discontinued because of side-effects. The statistical analysis was done according to the "intention to treat" principle. LA.P was significantly more efficient than placebo in reducing the frequency of migraine attacks (p = 0.01 by variance analysis). LA.P reduced the average number of monthly crises by 48% on day 84. There was a slight but significant reduction of the systolic blood pressure and heart rate in the erect position. There was no significant difference between LA.P and placebo regarding either the number of complaints or the number of side-effects elicited out of an 17 item questionnaire. None of the observed side effects led to a withdrawal of treatment.

Adult↗

[Amiodarone and hyperthyroidism. Several guidemarks for the practitioner].

The prevention and diagnosis of amiodarone-induced hyperthyroidism are largely based on clinical signs: a personal or family history of thyroid disorders, or an abnormality detected on palpation of the thyroid gland, are contraindications for amiodarone treatment. At that stage it is useless to determine hormone levels, since they do not permit screening of any cell metabolism abnormality. Weight loss accompanied by tachycardia is suggestive of amiodarone-induced hyperthyroidism. Amiodarone-induced hyperthyroidism will regress in 2 to 6 months after treatment discontinuation.

Amiodarone↗

Induction of MHC class II molecules HLA-DR, -DP and -DQ and ICAM 1 in human podocytes by gamma-interferon.

MHC class II-encoded molecules HLA-DR, -DP and -DQ play a pivotal role in the human immune response. Their constitutive expression is restricted to a number of immunocompetent cells referred to as antigen-presenting cells. However, gamma-interferon (gamma-IFN) has been shown to induce MHC class II molecule expression in several epithelia. Using flow cytometric analysis, we show here that normal and SV40-transformed human podocytes in culture constitutively expressed gamma-IFN receptors. We also show that MHC class I molecules are constitutively expressed in these cells and that HLA-DR, -DP and -DQ expression, which is not found in unstimulated cells, can be induced by gamma-IFN stimulation. This induction was a time-dependent event, a lag phase of 24-48 h being necessary for MHC class II molecules to become detectable at the cell surface by flow cytometric analysis. Induction of MHC class II molecules in human podocytes also showed a concentration dependence, a plateau being reached at a concentration of 500 IU of gamma-IFN/ml of culture medium. This effect was blunted by coincubation of the cells with an antihuman gamma-IFN receptor monoclonal antibody. HLA-DR expression was associated with specific mRNA accumulation, as detected by Northern blot analysis. By indirect immunofluorescence, the intercellular adhesion molecule 1 was also induced by gamma-IFN stimulation. Induction of DR, DP and DQ in human podocytes may be involved in the pathogenesis of immune glomerulonephritis in man.

Blotting, Northern↗