Glutathione S-transferase M1 and T1 polymorphisms and the risk of recurrent pregnancy loss.

The aetiology of recurrent pregnancy loss (RPL) remains unclear, but it may be related to a possible genetic predisposition together with involvement of environmental factors. We examined the relation between RPL and polymorphisms in two genes, glutathione S-transferases (GST) M1 and T1, which are involved in the metabolism of a wide range of environmental toxins and carcinogens. A case-control study of 115 cases with RPL and 160 controls was conducted. All cases and controls were women resident in Sapporo, Japan and the surrounding area. They were genotyped for polymorphisms of GSTM1 and GSTT1 using PCR-based methods. We found that 65.2% of the cases with RPL and 45.6% of the controls had the GSTM1 null genotype [odds ratio (OR) = 2.23, 95% confidence interval (CI) = 1.36-3.66]. On the other hand, 47.0% of the cases and 49.4% of the controls had the GSTT1 null genotype (OR = 0.95; 95% CI = 0.58-1.55). The results suggest that women with GSTM1 null polymorphism may therefore have an increased risk of RPL.

Impairment of neurobehavioral function and color vision loss among workers exposed to low concentration of styrene--a review of literatures.

Recently many studies on the health effects of workers who exposed to low-concentration styrene have been published. In this paper firstly we mentioned the reasons why nervous system was critical organ for evaluating the toxicity of organic solvents both in the acute and chronic exposure phases. Then we indicated how neurobehavioral test batteries were useful to detect subclinical adverse health effects of workers exposed to organic solvents. Secondly we reviewed many epidemiological studies on the impairment of neurobehavioral function, i.e., perceptual speed, memory, cognition, personality and mood, and the loss of color vision among styrene workers. Finally, we showed our recent data on the relationship between color vision loss and the concentration of urine metabolites among styrene workers. It can conclude that styrene may cause damage on nervous system, even at the low exposure level such as 50 ppm which used to be the Threshold Limit Value (TLV) recommended by Japan Society for Occupational Health (until 1999) and American Conference of Industrial Hygienists (until 1997).

Effects of Cyclosporin A on skin graft rejection in Xenopus.

In Xenopus, it has been shown that semi-xenogeneic adult skin grafts usually render donor-specific tolerance to perimetamorphic larvae, while these skin grafts are never accepted in adults. The mechanisms operating in this tolerance induction are largely unclear. The present investigation was planned to test whether lower responsiveness of larvae to non-self antigens could be ascribable to perimetamorphic tolerance induction. We tried to induce tolerance in adults by treating them with Cyclosporin A (CsA), which is known to decline the immune system in mammals. The results showed that CsA-treated adults could never be rendered tolerant to semi-xenogeneic skin grafts, although the grafts were not rejected as long as the treatment was continued. We have also proposed a possibly different mechanisms for the rejection of semi-xenogeneic skin grafts and of full-xenogeneic skin grafts.