Mutant Frigid A (fgdA) of Dictyostelium discoideum is defective in a functional Ga2 subunit of a G protein and is characterized by a complete blockade of the cyclic AMP-mediated sensory transduction steps, including cyclic AMP relay, chemotaxis and the cyclic GMP response. Folic acid-mediated transmembrane signal transduction was investigated in this mutant; the results show that: (1) cell surf...

The influence of folic acid upon various enzyme systems both in vivo and in vitro has recently been investigated by workers in several laboratories. In this laboratory it has been demonstrated that folic acid depresses xanthine oxidase activity when added to the enzyme systems in vitro (1) or when fed to chicks (2). It has also been shown that n-amino acid oxidase activity is decreased by dieta...

BACKGROUND The prevalence of neural tube defects (NTDs) in northern China remains high after 10 years since periconceptional supplementation with folic acid has been known to be effective in reducing the risk of NTDs. OBJECTIVE The objectives of this study were to characterize folic acid awareness and use and to examine the association between folic acid supplementation with blood folate conc...

BRANDENBURG, M.D.,* AND TOMAS ARAMBURU, M.D. I T HAS been established that pteroylglutamic acid (folic acid) stimulates the development of white blood cells, red blood cells and platelets in a variety of animal species and in persons who have certain types of macrocytic anemia. Our studies of folic acid have been concerned chiefly with the striking hematologic response which follows its adminis...

Evidence from controlled trials suggests that ingestion of 0.4 mg of folic acid per day in the periconceptional period is effective in preventing neural tube defects (NTD). For this reason, most countries recommend that women planning pregnancy take folic acid supplements in the periconceptional period, and some countries even fortify stable foods with folic acid. Denmark exemplifies a country ...

Intrauterine and early life exposure to folic acid has significantly increased in North America owing to folic acid fortification, widespread supplemental use, and periconceptional supplementation. We investigated the effects of maternal and postweaning folic acid supplementation on mammary tumor risk in the offspring. Female rats were placed on a control or folic acid-supplemented diet prior t...

In the investigation of malabsorption syndromes and folic acid deficiency, the folic acid absorption test may be used to determine the degree of absorption of folic acid from the intestine and also to measure the rate of clearance from the serum . The test is based on loading the patient with subcutaneous folic acid followed by an oral dose of this vitamin. Samples of blood are withdrawn at sui...

OBJECTIVE Periconceptional use of folic acid may effectively reduce the risk of fetal neural tube defects. The objective of the present study was to evaluate the awareness and use of folic acid during periconceptional period in Taiwan. MATERIALS AND METHODS A cross-sectional study was performed at Taiwan Adventist Hospital between March 2008 and December 2008. Data were obtained using a quest...

Oral folic acid above certain threshold doses results in unmetabolised folic acid in serum. This raises a number of public health safety issues, principally the potential to mask pernicious anaemia; more recently the theoretical potential for high-dose folic acid to promote cancer has been highlighted. In this paper we set out to examine the appearance of unmetabolised folic acid both in cord b...