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Biomedical subjects

L Beretta

Publications and source records attributed to L Beretta.

At least 109 records · Page 6Linked to original sources
PubMed1983

Erythrocyte antioxidant enzymes and selenium serum levels in an Andean population.

A preliminary study indicated that erythrocyte antioxidant enzyme activities were enhanced in chronic hypoxaemic patients, in whom an increased oxidant stress could be present as a consequence of augmented haemoglobin autoxidation. We have now evaluated the behaviour of erythrocyte antioxidant enzymes and of their related trace metal serum levels in conditions of chronic hypobaric hypoxia in an Andean population living at high altitude (3800 m above sea level), and in a similar ethnic group living at sea level. The results indicate a significant reduction in erythrocyte glutathione peroxidase activity and a low serum level of selenium in the Andean population. Thus, in contrast to what happens in chronic hypoxaemic patients, this group of Andean subjects seems to be poorly protected against oxidant stress, probably as a consequence of selenium deficiency in the diet.

Adult↗
PubMed1983

Antioxidant system in sickle red cells.

Erythrocytes containing abnormal haemoglobins with high affinity for red cell membrane are subjected to enhanced oxidant stress. Since HbS is known to have high affinity for red cell membrane and sickle cells are particularly susceptible to membrane lipid peroxidation, the behaviour of erythrocyte antioxidant system has been evaluated in 20 subjects, heterozygous for sickle cell anaemia. These subjects have shown normal levels of reduced glutathione, increased superoxide dismutase and glutathione peroxidase activities and low catalase activity. These data suggest that such an unbalanced antioxidant system can not prevent damage by the enhanced production of oxygen free radicals by membrane-bound HbS molecules.

Anemia, Sickle Cell↗
PubMed1982

Erythrocyte superoxide dismutase, catalase and glutathione peroxidase in glucose-6-phosphate dehydrogenase deficiency.

Glucose-6-phosphate dehydrogenase (G-6-PD) deficient erythrocytes are particularly sensitive to oxidant stress. In order to evaluate if these cells are protected against oxidant damage, we assayed the antioxidant enzymes superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px) in erythrocytes of G-6-PD deficient (hemizygous and heterozygous) subjects. Normal levels of antioxidant enzymes were found in all subjects examined both with positive and negative histories of haemolytic crisis after fava bean or drug ingestion. In contrast, high levels of catalase and GSH-Px were found in a small group of G-6-PD deficient subjects (hemizygous and heterozygous) with beta-thalassaemia trait, probably by reason of the chronically enhanced oxidant stress which is present in beta-thalassaemia.

Adolescent↗
PubMed1981

[Methemoglobinemia; a description of a case of NADH methemoglobulin reductase deficiency].

A case of NADH-methaemoglobin-reductase deficiency in a 64 year old man with marked cyanosis and without evidence of cardiac or pulmonary diseases is reported. The level of methaemoglobin was 36% and reached 25% after treatment with ascorbic acid. Erythrocyte NADH-methaemoglobin-reductase activity was only 5% of normal value. Some erythrocyte biochemical and enzymatic characteristics have been evaluated. A family study has also been carried out. Our patient has been considered homozygous for NADH-methaemoglobin-reductase deficiency.

Cytochrome-B(5) Reductase↗
PubMed1980

Erythrocyte superoxide dismutase, catalase and glutathione peroxidase activities in beta-thalassaemia (major and minor).

The 'antioxidant' enzymes superoxide dismutase (SD), catalase and glutathione peroxidase (GSH-Px) were found greatly elevated in red blood cells of subjects with beta-thalassaemia minor and similar to normal values in red blood cells of subjects with beta-thalassaemia major. These findings allows us to speculate that red cells in beta-thalassaemia minor react to the increased oxidant threat with augmented antioxidant enzyme activities. The normal levels of antioxidant enzymes in beta-thalassaemia major seem to be due to the presence of normal red cells owing to multiple transfusions.

Catalase↗
PubMed1980

Superoxide dismutase, catalase and glutathione peroxidase activities in maternal and cord blood erythrocytes.

The "antioxidant" enzymes superoxide dismutase, catalase and glutathione peroxidase were assayed in a biological model with low oxygen tension (red cells from cord blood of newborn infants). Catalase and glutathione peroxidase activities in red cells of newborns were significantly lower when compared with their mothers and with normal controls. In contrast, superoxide dismutase activity was unchanged. Thus, normal activities of superoxide dismutase seem to be necessary in order to protect red blood cells from superoxide radicals during foetal life, while even low activities of catalase and glutathione peroxidase are sufficient to protect red blood cells from hydrogen peroxide. No correlation was found between the "antioxidant" enzyme activities present in cord blood erythrocytes and the bilirubin concentrations during the first days of life.

Adult↗
PubMed1980

Serum myoglobin, total CK and MB CK isoenzyme after D.C. cardioversion and during the early phase of acute myocardial infarction.

Myoglobin, total CK and MB CK isoenzyme were determined in the sera of 6 patients admitted with arrhythmias and treated with D.C. countershock and also in 37 patients with acute myocardial infarction or anginal syndrome. All the three tests were increased in patients with myocardial infarction. Serum myoglobin seems sufficiently sensitive and specific but the time required for the assay is a limiting factor for practical use in emergencies. After electrical cardioversion, myoglobin and CPK remain normal, although MB isoenzyme was increased in two of six patients. These results suggest that electrical cardioversion in itself does not influence serum levels of myoglobin. The occasional increase of MB CK observed after cardioversion seems to be the consequence of an easier release of the enzyme due to a myocardial injury.

Adult↗
PubMedDate not supplied

Left ventricular volume reduction for end-stage heart disease.

Partial left ventriculectomy (PLV) was recently introduced for end-stage dilated cardiomyopathy to improve ventricular function. Since November 1996 we have performed PLV in 14 patients; preoperatively 4 patients had idiopathic dilated cardiomyopathy and 10 had ischemic dilated cardiomyopathy. 57.1% of patients were in New York Heart Association functional Class IV. The mitral valve was replaced in 11 patients. Postoperative echocardiography showed a reduction of left end-diastolic diameter (55.4 +/- 5.4 mm) and an increase in forward ejection (cardiac index from 2.19 +/- 0.571 min/m2 to 2.67 +/- 0.931/min/m2). The 30-day mortality was 28.6% and 20-month survival was 57.2%. Only one patient was not in NYHA functional class due to postoperative progressive mitral incompetence. Prognostic factors should be identified to avoid early failure. However, even if the mortality rate for PLV high, this operation is a valid choice for the treatment of end-stage dilated cardiomyopathy.

Actuarial Analysis↗