An analysis of methylenetetrahydrofolate reductase and glutathione S-transferase omega-1 genes as modifiers of the cerebral response to ischemia.

BACKGROUND: Cerebral ischemia involves a series of reactions which ultimately influence the final volume of a brain infarction. We hypothesize that polymorphisms in genes encoding proteins involved in these reactions could act as modifiers of the cerebral response to ischemia and impact the resultant stroke volume. The final volume of a cerebral infarct is important as it correlates with the morbidity and mortality associated with non-lacunar ischemic strokes. METHODS: The proteins encoded by the methylenetetrahydrofolate reductase (MTHFR) and glutathione S-transferase omega-1 (GSTO-1) genes are, through oxidative mechanisms, key participants in the cerebral response to ischemia. On the basis of these biological activities, they were selected as candidate genes for further investigation. We analyzed the C677T polymorphism in the MTHFR gene and the C419A polymorphism in the GSTO-1 gene in 128 patients with non-lacunar ischemic strokes. RESULTS: We found no significant association of either the MTHFR (p = 0.72) or GSTO-1 (p = 0.58) polymorphisms with cerebral infarct volume. CONCLUSION: Our study shows no major gene effect of either the MTHFR or GSTO-1 genes as a modifier of ischemic stroke volume. However, given the relatively small sample size, a minor gene effect is not excluded by this investigation.

Analysis of the endothelial nitric oxide synthase gene as a modifier of the cerebral response to ischemia.

We studied the endothelial nitric oxide synthase (eNOS or NOS-3) gene as a potential modifier of the cerebral response to ischemia by investigating the association of two common polymorphisms with ischemic stroke volume. We genotyped an intronic variable number tandem repeat and a single nucleotide polymorphism, G894T, in 132 patients with nonlacunar ischemic strokes in whom clinical data and stroke lesion volume were recorded. Our results show that all genotypes are in Hardy-Weinberg equilibrium. After adjustment of covariates, neither of the NOS-3 polymorphisms showed significant differences comparing the genotypes and mean stroke volume (analysis of variance). Our results do not suggest a major gene effect of the NOS-3 gene as a modifier of the cerebral response to ischemia.

Utilizaciòn del concentrado de alga calcàrea (Lithothamnium S P) en la raciòn de helix aspersa, muller,1774 (gastropoda, helicidae) / Use of concentrate of calcareous alga (Lithothamnium S P) in the ration of helix aspersa, muller, 1774 (gastropoda, helicidae)

Se estudiò el uso del alga calcàrea (Lithothamnium sp) en su estado vivo i fòsil, en la raciòn de 60 caracoles con 64 dias de edad, provenientes de una ùnica postura. Los caracoles fueron distribuidos en 5 grupos de 12 ejemplares y sometidos a 4 tratamientos y 1 control: se analizò el peso y el diàmetro mayor de la concha al inicio y final del experimento (70 dias). Se calculò el consumo de la dieta, el incremento de peso/consumo y la tasa de crecimiento ponderal/dia. Con la aplicaciòn del concentrado de alga fòsil al 30,77 por cento como fuente completa de calcio de la raciòn y el concentrado de alga viva al 0,20 por cento, se obtuvieron valores òptimos de incremento de peso y crecimiento de la concha. La ingestiòn, el peso y el crecimiento de los caracoles alimentados con el concentrado de alga viva y el de alga viva calentada a 65 C en la composiciòn de 30,77 por cento, fueron màs bajos que el control. Estos resultados sugieren que el concentrado de alga fòsil puede ser utilizado como fuente de calcio con efectos significativos en el crecimiento de helix aspersa, cuando se comparan con los obtenidos con otras fuentes de calcio usualmente utilizadas. Por otro lado, la ausencia de carbonato en el alga viva puede ser responsable por el reducido efecto en el aprovechamiento de calcio en esta especie