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Biomedical subjects

J F Vargas

Publications and source records attributed to J F Vargas.

6 recordsLinked to original sources
PubMed1998

Oxidative stress in diabetic rats induced by streptozotocin: protective effects of melatonin.

We have studied the effect of the administration of two doses of melatonin (melatonin 100 and melatonin 200 microg/kg bw) on diabetes and oxidative stress experimentally induced by the injection of streptozotocin (STZ) in female Wistar rats. STZ was injected as a single dose (60 mg/kg i.p. in buffered citrate solution, pH 4.0) and melatonin (melatonin 100, 100 microg/kg/day i.p.; melatonin 200, 200 microg/kg/day i.p.) beginning 3 days before diabetes induction and continuing until the end of the study (8 weeks). The parameters analysed to evaluate oxidative stress and the diabetic state were a) for oxidative stress, changes of lipoperoxides (i.e., malondialdehyde, MDA) in plasma and erythrocytes and the changes in reduced glutathione (GSH) in erythrocytes and b) for diabetes, changes in glycemia, lipids (triglycerides: TG; total cholesterol: TC; HDL-cholesterol, HDL-c), percentage of glycosylated hemoglobin (Hb%), and plasma fructosamine. The injection of STZ caused significant increases in the levels of glycemia, percentage of glycosylated hemoglobin, fructosamine, cholesterol, triglycerides, and lipoperoxides in plasma and erythrocytes, whereas it decreased the levels of HDL-c and the GSH content in erythrocytes. The melatonin 100 dose reduced significantly all these increases, except the percentage of glycosylated hemoglobin. With regard to the decreases of plasma HDL-c and GSH content in erythrocytes, this melatonin dose returned them to normal levels. The melatonin 200 dose produced similar changes, though the effects were especially noticeable in the decrease of glycemia (55% vs. diabetes), percentage of hemoglobin (P < 0.001 vs diabetes), and fructosamine (31% vs. diabetes). This dose also reversed the decreases of HDL-c and GSH in erythrocytes. Both doses of melatonin caused significant reduction of the percentage of glycosylated hemoglobin in those groups that were non-diabetic. These illustrate the protective effect of melatonin against oxidative stress and the severity of diabetes induced by STZ. In particular, this study confirms two facts: 1) the powerful antioxidant action of this pineal indole and 2) the importance of the severity of oxidative stress to maintain hyperglycemia and protein glycosylation, two pathogenetic cornerstones indicative of diabetic complications. Melatonin reduces remarkably the degree of lipoperoxidation, hyperglycemia, and protein glycosylation, which gives hope to a promising perspective of this product, together with other biological antioxidants, in the treatment of diabetic complications where oxidative stress, either in a high or in a low degree, is present.

Animals↗
PubMed1991

[Postoperative hyperuricemia of cyanotic and acyanotic congenital cardiopathies].

In a prospective study, 10 children with congenital heart disease were studied before and after surgery (24-48 h). Mean age and weight, type of disease and surgery performed are described in Table 1. Six patients had acyanotic disease and 4 were cyanotic. Before surgery, the acyanotic group (AG) showed hyperuricemia compared to normal children of the same chronological age (mean +/- SE: 5.53 +/- 0.42 vs 4.27 +/- 0.22, p less than 0.02). Initial seric creatinine (sCr), increased in 3 patients of the AC and in the 4 patients of the cyanotic group (CG) compared to normal values of sCr for height (AG: 0.47 +/- 0.05 vs 0.34 +/- 0.03, p less than 0.05; CG: 0.63 +/- 0.05 vs 0.38 +/- 0.05, p less than 0.01). Post-surgery, sCr and serum uric acid (sUA) increased significantly at 24 and 48 h in both groups (Fig 1); at 24 h the increment in sUA in the AG was higher than that in the CG (p less than 0.05). There was a direct and significant correlation between the increment in sUA and sCr in the AG (Fig. 2). The urine excretion of uric acid paralleled the increment of sUA in the CG (Table 2). Fractional excretion of, sodium (FENa) was less than 1% and greater than 1% in the AG and the CG, respectively, being the basal FENa of the AG significantly lower (Table 3).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiopulmonary Bypass↗
PubMedDate not supplied

Anapsos, an antipsoriatic drug, in atopic dermatitis.

An open, controlled study was carried out in young patients with atopic dermatitis, who during one month received oral anti-psoriatic drug, anapsos (n = 46), or antihistamines (n = 30), simultaneously with topic applications. The activity and extension of the cutaneous lesions improved under both treatments, but more markedly with anapsos in spite of the fact that topical applications did not contain steroids in the group treated with anapsos, and the effect was still appreciable several months after interruption of medication. Anapsos, which was well tolerated, considerably relieved the respiratory symptoms of all patients with asthma. Studies performed on patients with atopic dermatitis have shown high IgE levels, eosinophils and T4 counts, and a marked decrease in T8 suppressor cells in peripheral blood. Our data also show a slight decrease in T8 cells (%), a significant increase in T4 sub-sets (%) and a high T4/T8 ratio as a previously reported by several authors. Such an imbalance between helper and suppresor cells may cause alterations in the response to extrinsic and intrinsic antigens, as shown in particular by the abnormally high IgE levels observed in atopic dermatitis. Anapsos was associated with a correction in T lymphocytes imbalances, specifically through the increase of the initially low T8 cells levels and subsequent normalization of the mean T4/T8 index. The tolerance and promising therapeutic activity of this antipsoriatic drug deserve further research in other conditions characterized by a deficit of suppressor cells.

Administration, Oral↗