Neural tube

L-Fohc acid is available as a crystalline dihydrate containing 8% water. Approximately 80% of the commercial production is consumed for feed enrichment in animal nutrition. FoHc acid is being offered by the pharmaceutical industry for therapeutic and prophylactic use (see Pharmaceuticals). Pharmacological doses of fohc acid are commonly used as a rescue dose during cancer chemotherapy, in women using oral contraceptives, and alcohoHcs. Several studies have provided evidence that multivitamins or foHc acid (0.8—4 mg/day) supplementation prevent the majority of neural tube defects (101). 

It is recommended that women of childbearing age take 400 pg/d synthetic folic acid as a supplement in order to reduce the risk of neural tube defects of the embryo when they later become pregnant (periconcep-tional folic acid supplementation) [2]. When supplementing folic acid, it should be considered that this vitamin can mask the simultaneous presence of vitamin B12 deficiency. The typical symptom of vitamin B12 deficiency, megaloblastic (= macrocytic) anemia, will be reduced by high doses of folic acid, yet the nervous system will - in the long run - be irreversibly damaged (= funicular myelitis) when vitamin B12 is not provided as well. 

Folic Acid Supplements Reduce the Risk of Neural Tube Defects Hyperhomocysteinemia... 

The monitoring of pregnancies for neural tube defects Is the most recent of the Indications for prenatal diagnosis In families In which one child has been affected, the risk of recurrence Is approximately 4% Of the 16 pregnancies In which amniocentesis was done to determine the level of a-fetoprotein, no affected fetuses were found ... 

Mclssac and Joshl, M. S. "Prenatal Detection of Neural Tube Defects. Comparison Between Alpha Fetoprotein and Beta-Trace Protein Assays". Amer. J. Obstet. Gynecol,... 

SCOTT J M, KiRKEP N and WEIR D G (1990) The role of nutrition in neural tube defects ,... 

Screens for Down s syndrome and neural tube defects (at 15-20 weeks)... 

Folic acid 400 meg orally daily High risk = personal or family history of neural tube defects... 

Neural tube defects Birth defect resulting from improper development of the central nervous system. 

Epstein, D. J., Vekemans, M., and Gros, P. (1991). Splotch, a mutation affecting development of the mouse neural tube, shows a deletion within the paired homeodomain of Pax-3. Cell 67 767-774. 

Chia We are neophytes with mice. We have looked, using elecroporation and GFP fusions, but we are not convinced enough to say whether there is asymmetric localization. There is certainly expression in the neural tube. 

The best examples of pleiotropy have been provided by developmental biologists. Two examples illustrate the pleiotropic action of developmental genes. Sonic hedgehog participates in the formation of the different cell types that form the neural tube, in limb development and in somitogenesis, a process by which mesodermic cells aggregate to form bones and muscles. 

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