Glucose-6-phosphate dehydrogenase activity, structure, molecular characteristics and role in neonatal hyperbilirubinemia in cord blood in Cukurova region.

The most common causes of neonatal indirect hyperbilirubinemia are blood incompatibility and erythrocyte enzyme defects. Glucose-6-phosphate dehydrogenase (G6PD) is a guarantee of erythrocyte stability and capability of existence of red cells. We present here the results of a study on the effect of enzyme kinetics and different mutations on neonatal hyperbilirubinemia in the Cukurova region. Two hundred healthy term male neonates born in Cukurova University Balcall Hospital, Adana Maternity Hospital and Cukurova Maternal and Children's Hospital between 1 November 2004 and 30 November 2007 were consecutively studied. Nanogen DNA microarray was used to determine Gd Union, Gd San, Gd Mediterranean, and Gd San Antonio mutations. Quantitative G6PD enzyme assays were performed. Glucose-6-phosphate dehydrogenase deficiency was detected in six out of 200 male neonates (3%). The other 194 neonates had normal G6PD activity, with a mean of 8.3 +/- 2.1 IU/g hemoglobin (Hb) (5.2-12.7 IU/g Hb). Clinical follow-up, enzyme kinetics and genetic studies were performed in the G6PD-deficient neonates. Differences were observed in clinical outcomes, rates of bilirubin decline and maximum total bilirubin levels in the neonates having the same mutation. These differences might be caused by the effects of kinetic variant on the hyperbilirubinemia without the direct effect of the mutation. In future studies, mutation analyses of further G6PD-deficient cases may address the genotype differences and their clinical effects in G6PD-deficient patients.

Oxidative stress and apoptosis in relation to exposure to magnetic field.

We investigated the effect of extremely low-frequency electromagnetic field (ELF-EMF) with pulse trains exposure on lipid peroxidation, and, hence, oxidative stress in the rat liver tissue. The parameters that we measured were the levels of plasma alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase as well as plasma albumin, bilirubin, and total protein levels in 30 adult male Wistar rats exposed to ELF. We also determined the percentage of apoptotic and necrotic cells of the kidney extracts from the animals by flow cytometry method. Apoptotic cell death was further characterized by monitoring DNA degradation using gel electrophoresis. The results showed an increase in the levels of oxidative stress indicators, and the flow cytometric data suggested a possible relationship between the exposure to magnetic field and the cell death. We showed significantly lower necrotic cell percentages in experimental animals compared to either unexposed or sham control groups. However, DNA ladder analyses did not differentiate between the groups. Our results were discussed in relation to the response of biological systems to EMF.