Study of Sex Hormone-binding Globulin Gene Polymorphism and Risk of Type 2 Diabetes Mellitus in Egyptian Men.

OBJECTIVES: Conditions of hypoandrogenism in men have been linked to insulin resistance, suggesting that alterations in normal sex steroid physiology could play a role in the pathogenesis of Type 2 diabetes mellitus (T2DM). Sex hormone-binding globulin (SHBG) gene polymorphisms may be the cause of sex steroid alteration. The aim of this work is to study the effect of SHBG gene polymorphisms on the risk of T2DM through its impact on testosterone and oestradiol level in Egyptian men. SUBJECTS AND METHODS: A case control study was performed in the diabetes clinic at Zagazig University Hospital on 185 males with Type 2 diabetes and their matched healthy controls. Two polymorphisms (rs6257 and rs6259) of the gene encoding SHBG were genotyped and serum levels of SHBG, testosterone and oestradiol were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Carriers of rs6257 variant allele (CC or CT) and carriers of rs6259 wild allele (GG) appear to have a high risk of diabetes than carriers of other alleles (OR 2.241, 1.585 and 2.391, respectively). They also showed a significant decrease in plasma level of both SHBG and testosterone and a significant increase in oestradiol blood level compared with carriers of other alleles. CONCLUSIONS: Sex hormone-binding globulin gene polymorphisms at position rs6257 and rs6259 are associated with higher risk of T2DM in Egyptian men, through lowering circulating levels of SHBG and consequently, lowering testosterone and elevating oestradiol level.

Protective effects of alpha-lipoic acid against benzene induced toxicity in experimental rats.

OBJECTIVE: The aim of the present study was to examine the potential protective effects of Alpha-Lipoic Acid (ALA) against benzene induced alteration in CYP2E1 gene function, DNA damage as well as the oxidant-antioxidant status. MATERIALS AND METHODS: Fifty adult male Wister rats were used for this study. Rats were randomized and divided into four groups: Group I was designated as control group and received a vehicle of olive oil; Group II was received alpha lipoic acid in a dose of (20 mg/kg, i.p.); Group III received only I.M. injection of benzene in a dose of 2 ml/kg. Group IV received both alpha lipoic acid in a dose of (20 mg/kg, i.p.) and I.M. injection of benzene in a dose of 2 ml/kg. The animals were treated on each alternate day for 30 days then all rats were sacrificed and both blood and liver tissue samples were taken to measure serum malondialdehyde (MDA) Level; serum level of reduced glutathione (GSH); level of serum 8-hydroxy-2'-deoxyguanosine; hepatic microsomal cytochrome P450 2E1 activity and gene expression. RESULTS: Benzene significantly increased serum malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG) and both CYP2E1 activity and gene expression but significantly decreased level of reduced glutathione (GSH). These changes are reversed upon administration of ALA. CONCLUSIONS: The current study provided evidence that the linkage between CYP2E1-dependent oxidative stress, DNA damage, and GSH homeostasis could contribute to the toxic actions of benzene which can be counteracted by ALA by its suppression action on CYP2E1, inhibition of lipid peroxidation and oxidative DNA damage as well as maintenance of intracellular antioxidants status.

Phylogenetic relationships of Malayan gaur with other species of the genus Bos based on cytochrome b gene DNA sequences.

The Malayan gaur (Bos gaurus hubbacki) is one of the three subspecies of gaurs that can be found in Malaysia. We examined the phylogenetic relationships of this subspecies with other species of the genus Bos (B. javanicus, B. indicus, B. taurus, and B. grunniens). The sequence of a key gene, cytochrome b, was compared among 20 Bos species and the bongo antelope, used as an outgroup. Phylogenetic reconstruction was employed using neighbor joining and maximum parsimony in PAUP and Bayesian inference in MrBayes 3.1. All tree topologies indicated that the Malayan gaur is in its own monophyletic clade, distinct from other species of the genus Bos. We also found significant branching differences in the tree topologies between wild and domestic cattle.