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PubMed1998

Antioxidant enzymes and fatty acid status in erythrocytes of Down's syndrome patients.

The excess of genetic information in patients with Down's syndrome (DS) produces an increase in the catalytic activity of superoxide dismutase (SOD1), an antioxidant enzyme coded on chromosome 21. It has been suggested that an increase in oxidative stress in DS patients may cause adverse effects in the cell membranes through the oxidation of polyunsaturated fatty acids (PUFAs). The aim of this study was to evaluate the cellular antioxidant system by determining the catalytic activity of the SOD1, glutathione peroxidase (GPx), catalase (CAT), and glutathione reductase (GR) enzymes and the concentrations of alpha-tocopherol in red blood cells (RBCs) in a group of 72 DS patients. The profile of fatty acids in the phospholipids of RBC membranes was also evaluated. The activity of the erythrocyte antioxidant enzymes is significantly higher in the DS group than in the control group (SOD1, 635 +/- 70 U/g Hb vs 476 +/- 67 U/g Hb; CAT, 1843 +/- 250 U/g Hb vs 1482 +/- 250 U/g Hb; GPx, 23.2 +/- 5.3 U/g Hb vs 21.5 +/- 3.6 U/g Hb; and GR, 9.32 +/- 1.4 U/g Hb vs 6.9 +/- 1.3 U/g Hb, respectively). No differences were observed in RBC alpha-tocopherol concentrations between the two groups studied. Long-chain n6 PUFA (C20:3n6, C20:4n6) concentrations were increased in DS patients, suggesting enhanced delta-6-desaturase activity. The long-chain n3 PUFA (docosahexenoic acid) does not appear to be affected by increased oxidative stress, probably because of the existence of compensatory antioxidant mechanisms.

Adolescent↗

PubMed1989

Partial nephrectomy for tumour.

Thirty-three cases of malignant renal tumour removed by partial nephrectomy are discussed. The indications of this conservative therapy as well as the surgical technique, the results obtained, especially survivals beyond 10 years, as well as the period of time after which the neoplastic disease can be considered as cured are presented.

Adolescent↗

PubMedDate not supplied

Limited effectiveness of femur and humerus shortening as markers of Down syndrome in early midtrimester fetuses.

This is a prospective screening study addressed to assess the value of femur and humerus shortening in the prenatal detection of Down syndrome. Prior to amniocentesis, 1,543 consecutive pregnancies between 13 and 18 weeks were studied. Femur and humerus shortening were assessed with the use of 6 different ratios, and then correlated with the karyotype obtained in amniotic fluid. Sensitivities achieved for Down syndrome with femur ratios were lower than those using humerus (17-22 vs. 43%) for similar false-positive rates (7-8 vs. 6-8%). The most effective ratio was the observed-to-expected humerus length with 43% sensitivity for a 6% false-positive rate. Combining femur and humerus measurements did not substantially improve the prediction obtained using the best humeral ratio. In conclusion, femur and humerus shortening appears to be of limited value in the detection of Down syndrome.

Adult↗