Biofactors - Volume 10, issue 2-3

Authors: Molloy, Anne M. | Mills, James L. | Kirke, Peadar N. | Weir, Donald G. | Scott, John M.

Article Type: Research Article

Abstract: Periconceptional folic acid supplementation prevents approximately 70% of neural tube defects (NTDs). While most women carrying affected fetuses do not have deficient blood folate levels, the risk of having an NTD affected child is inversely correlated with pregnancy red cell folate levels. Current research is focused on the discovery of genetic abnormalities in folate related enzymes which might explain the role of folate in NTD prevention. The first candidate gene to emerge was the C677T variant of 5,10‐methylenetetrahydrofolate reductase. Normal subjects who are homozygous for the mutation (TT) have red cell folate status some 20% lower than expected. It is …now established that the prevalence of the TT genotype is significantly higher among spina bifida cases and their parents. Nevertheless, our studies show that the variant does not account for the reduced blood folate levels in many NTD affected mothers. We conclude that low maternal folate status may in itself be the most important risk factor for NTDs and that food fortification may be the only population strategy of benefit in the effort to eliminate NTDs. Show more

Keywords: Folate status, methylenetetrahydrofolate reductase, neural tube defects, thermolabile MTHFR, red cell folates, pregnancy

Citation: Biofactors, vol. 10, no. 2-3, pp. 291-294, 1999

Authors: Itokawa, Y. | Hashizume, N. | Asano, M. | Igarashi, O. | Mino, M. | Ihara, H. | Ishiwata, Y. | Kadowaki, H. | Kubota, N. | Okazaki, M. | Sueki, K. | Ishida, Y. | Gorin, M. | Sato, T. | Sayama, Y. | Shimomura, K. | Takano, H. | Nakamura, T. | Hanawa, M. | Niimura, H. | Morio, T. | Chibata, I. | Okuda, K.

Article Type: Research Article

Abstract: Standard reference ranges for all laboratory test values are mandatory. This study was designed to establish a reference range for blood vitamin B_{1} levels, since the normal range has not been determined in the Japanese population. We founded the Japan Committee for Vitamin Laboratory Standards, which was incorporated with the Vitamin Society of Japan and the Japanese Society of Nutrition and Food Science. We standardized whole blood vitamin B_{1} levels using three HPLC techniques (post‐column reverse‐phase HPLC, pre‐column reverse‐phase HPLC, and precolumn GP‐HPLC). The reference range was obtained in 54 volunteers administered a 1,800 kcal diet …with 2 mg of vitamin B_{1} (1.74 mg measured) daily to avoid marginal vitamin B_{1} deficiency in the population. The range for each assay was 26–47, 28–51, and 28–56 ng/ml, respectively. Our data suggest that 26–28 ng/ml is the lower limit of normal for whole blood vitamin B_{1} , but further studies in a larger population are needed in order to obtain more definitive results. Show more

Citation: Biofactors, vol. 10, no. 2-3, pp. 295-299, 1999

Authors: Horiuchi, Masahisa | Kobayashi, Keiko | Masuda, Mina | Terazono, Hiroki | Saheki, Takeyori

Article Type: Research Article

Abstract: We isolated a mouse homologue cDNA of pyruvate dehydrogenase (PDH) kinase 4 (PDK4) with differential mRNA display as an up‐regulated gene in the hypertrophied ventricles of juvenile visceral steatosis (JVS) mice with systemic carnitine deficiency. The PDK4 mRNA level was 5 times higher in JVS mice than in control mice under fed conditions. After 24 h starvation, this level increased to 20 times in JVS and 7 times in control, compared with the control fed level. On the other hand, carnitine administration reduced the high level of PDK4 mRNA in JVS mice to the control fed level. In control mice, …the change in PDK4 mRNA was inversely correlated with the change in PDH activity. In JVS mice, however, the PDK4 mRNA level was not always correlated with the active‐form PDH level. Show more

Keywords: Carnitine deficiency, cardiac hypertrophy, differential display, juvenile visceral steatosis mouse, pyruvate dehydrogenase kinase

Citation: Biofactors, vol. 10, no. 2-3, pp. 301-309, 1999