Sister-chromatid exchanges in β-thalassaemic patients under conditions of in vivo and in vitro depletion of folic acid

In order to investigate the effect of folate depletion, lymphocyte sister-chromatid exchange (SCE) rates were compared among homozygous β-thalassaemic patients with low folic acid levels, heterozygous β-thalassaemic patients with normal folate levels and healthy persons with normal haemoglobin, in cultures with both normal and depleted folate conditions. Significantly higher SCE rates were found in homozygous patients in all assays, but the in vitro folate depletion did not induce an increase in SCE frequency in any group.

High dosage folic acid supplementation, oral cleft recurrence and fetal growth

Objectives: To evaluate the effects of folic acid supplementation on isolated oral cleft recurrence and fetal growth. Patients and Methods: The study included 2,508 women who were at-risk for oral cleft recurrence and randomized into two folic acid supplementation groups: 0.4 and 4 mg per day before pregnancy and throughout the first trimester. The infant outcome data were based on 234 live births. In addition to oral cleft recurrence, several secondary outcomes were compared between the two folic acid groups. Cleft recurrence rates were also compared to historic recurrence rates. Results: The oral cleft recurrence rates were 2.9% and 2.5% in the 0.4 and 4 mg groups, respectively. The recurrence rates in the two folic acid groups both separately and combined were significantly different from the 6.3% historic recurrence rate post the folic acid fortification program for this population (p = 0.0009 when combining the two folic acid groups). The rate of cleft lip with palate recurrence was 2.9% in the 0.4 mg group and 0.8% in the 4 mg group. There were no elevated fetal growth complications in the 4 mg group compared to the 0.4 mg group. Conclusions: The study is the first double-blinded randomized clinical trial (RCT) to study the effect of high dosage folic acid supplementation on isolated oral cleft recurrence. The recurrence rates were similar between the two folic acid groups. However, the results are suggestive of a decrease in oral cleft recurrence compared to the historic recurrence rate. A RCT is still needed to identify the effect of folic acid on oral cleft recurrence given these suggestive results and the supportive results from previous interventional and observational studies, and the study offers suggestions for such future studies. The results also suggest that high dosage folic acid does not compromise fetal growth. © 2013 by the authors; licensee MDPI, Basel, Switzerland.

A Solid Film Electrode of Intermetallic Ag 2 Hg 3.02 for the Direct Determination of Folic Acid in Fresh and Processed Fruit Juices

AgSIE was used for the direct analysis of folic acid (FA), with a detection limit and lower level of quantitation of 6.8 x10-10 mol L-1 and 2.3 x 10 8 mol L-1. The analysis in fresh and processed fruits was done without any sample pretreatment. In strawberry and acerola juices, FA concentration level values were below the method detection limit. FA was detectable in peach (77.7 0.4 mg L-1 and 64.4 0.5 mgL-1), Persian lime (45.4 0.7 mg L-1), pineapple Hawaii (66.2 0.4 mgL-1), pear pineapple (35.3 0.6 mgL-1), cashew (54.4 0.5 mgL-1) , passion fruit (73.2 0.3 mgL-1), and apple (84.4 0.5 mg L-1 ).

Elevated serum folic acid concentrations were associated with higher mRNA expression of DHFR gene in patients with hereditary spherocytosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

High dosage folic acid supplementation, oral cleft recurrence and fetal growth

Objectives: To evaluate the effects of folic acid supplementation on isolated oral cleft recurrence and fetal growth. Patients and Methods: The study included 2,508 women who were at-risk for oral cleft recurrence and randomized into two folic acid supplementation groups: 0.4 and 4 mg per day before pregnancy and throughout the first trimester. The infant outcome data were based on 234 live births. In addition to oral cleft recurrence, several secondary outcomes were compared between the two folic acid groups. Cleft recurrence rates were also compared to historic recurrence rates. Results: The oral cleft recurrence rates were 2.9% and 2.5% in the 0.4 and 4 mg groups, respectively. The recurrence rates in the two folic acid groups both separately and combined were significantly different from the 6.3% historic recurrence rate post the folic acid fortification program for this population (p = 0.0009 when combining the two folic acid groups). The rate of cleft lip with palate recurrence was 2.9% in the 0.4 mg group and 0.8% in the 4 mg group. There were no elevated fetal growth complications in the 4 mg group compared to the 0.4 mg group. Conclusions: The study is the first double-blinded randomized clinical trial (RCT) to study the effect of high dosage folic acid supplementation on isolated oral cleft recurrence. The recurrence rates were similar between the two folic acid groups. However, the results are suggestive of a decrease in oral cleft recurrence compared to the historic recurrence rate. A RCT is still needed to identify the effect of folic acid on oral cleft recurrence given these suggestive results and the supportive results from previous interventional and observational studies, and the study offers suggestions for such future studies. The results also suggest that high dosage folic acid does not compromise fetal growth

The impact of polymorphisms in P-gp, DNA repair and folic acid metabolism genes in newly diagnosed multiple myeloma patients treated with thalidomide plus dexamethasone, with or without bortezomib

The principle aim of this study was to investigate biological predictors of response and resistance to multiple myeloma treatment. Two hypothesis had been proposed as responsible of responsiveness: SNPs in DNA repair and Folate pathway, and P-gp dependent efflux. As a first objective, panel of SNPs in DNA repair and Folate pathway genes, were analyzed. It was a retrospective study in a group of 454, previously untreated, MM patients enrolled in a randomized phase III open-label study. Results show that some SNPs in Folate pathway are correlated with response to MM treatment. MTR genotype was associated with favorable response in the overall population of MM patients. However, this relation, disappear after adjustment for treatment response. When poor responder includes very good partial response, partial response and stable/progressive disease MTFHR rs1801131 genotype was associated with poor response to therapy. This relation - unlike in MTR – was still significant after adjustment for treatment response. Identification of this genetic variant in MM patients could be used as an independent prognostic factor for therapeutic outcome in the clinical practice. In the second objective, basic disposition characteristics of bortezomib was investigated. We demonstrated that bortezomib is a P-gp substrate in a bi-directional transport study. We obtain apparent permeability rate values that together with solubility values can have a crucial implication in better understanding of bortezomib pharmacokinetics with respect to the importance of membrane transporters. Subsequently, in view of the importance of P-gp for bortezomib responsiveness a panel of SNPs in ABCB1 gene - coding for P-gp - were analyzed. In particular we analyzed five SNPs, none of them however correlated with treatment responsiveness. However, we found a significant association between ABCB1 variants and cytogenetic abnormalities. In particular, deletion of chromosome 17 and t(4;14) translocation were present in patients harboring rs60023214 and rs2038502 variants respectively.

Folic acid derivatives for PET imaging and therapy addressing folate receptor positive tumors

Folic acid, also known as vitamin B9, is the oxidized form of 5,6,7,8-tetrahydrofolate, which serves as methyl- or methylene donor (C1-building blocks) during DNA synthesis. Under physiological conditions the required amount of 5,6,7,8-tetrahydrofolate for survival of the cell is accomplished through the reduced folate carrier (RFC). In contrast, the supply of 5,6,7,8-tetrahydrofolate is insufficient under pathophysiological conditions of tumors due to an increased proliferation rate. Consequently, many tumor cells exhibit an (over)expression of the folate receptor. This phenomenon has been applied to diagnostics (PET, SPECT, MR) to image FR-positive tumors and on the other hand to treat malignancies related to a FR (over)expression. Based on this concept, a new 18F-labeled folate for PET imaging has been developed and was evaluated in vivo using tumor-bearing mice. The incorporation of oligoethylene spacers into the molecular structure led to a significant enhancement of the pharmacokinetics in comparison to previously developed 18F-folates. The liver uptake could be reduced by one sixth by remaining a tumor uptake of 3%ID/g leading to better contrast ratios. Encouraged by these results, a clickable 18F-labeled serine-based prosthetic group has been synthesized, again with the idea to improve the metabolic and pharmacokinetic profile of hydrophilic radiotracers. Therefore, an alkyne-carrying azido-functionalized serine derivative for coupling to biomolecules was synthesized and a chlorine leaving group for 18F-labeling, which could be accomplished using a microwave-assisted synthesis, a [K⊂2.2.2]+/carbonate system in DMSO. Radiochemical yields of 77±6% could be achieved.rnThe promising results obtained from the FR-targeting concept in the diagnostic field have been transferred to the boron neutron capture therapy. Therefore, a folate derivative was coupled to different boron clusters and cell uptake studies were conducted. The synthesis of the folate-boron clusters was straightforward. At first, a linker molecule based on maleic acid was synthesized, which was coupled to the boron cluster via Michael Addition of a thiol and alkene and subsequently coupled to the targeting moiety using CuAAC. The new conjugates of folate and boron clusters led to a significant increase of boron concentration in the cell of about 5-times compared to currently used and approved boron pharmaceuticals. rnMoreover, azido-folate derivatives were coupled to macromolecular carrier systems (pHPMA), which showed an enhanced and specific accumulation at target sites (up to 2.5-times) during in vivo experiments. A specific blockade could be observed up to 30% indicating an efficient targeting effect. A new kind of nanoparticles consisting of a PDLLA core and p((HPMA)-b-LMA)) as surfactants were developed and successfully radiolabeled via 18F-click chemistry in good RCYs of 8±3%rnThe nanoparticles were obtained via the miniemulsion technique in combination with solvent evaporation. The 18F-labeled nanoparticles were applied to in vivo testing using a mouse model. PET imaging showed a “mixed” biodistribution of low molecular weight as well as high molecular weight systems, indicating a partial loss of the 18F-labeled surfactant.rnIn conclusion, the presented work successfully utilized the FR-targeting concept in both, the diagnostic field (PET imaging) and for therapeutic approaches (BNCT, drug delivery systems). As a result, the high potential of FR-targeting in oncological applications has been shown and was confirmed by small animal PET imaging.rn

Neural tube defects in Mexican-Americans living on the US-Mexico border: The effects of folic acid and dietary folate

Neural tube defects (NTDs) are malformations of the developing brain and spinal cord; the most common are anencephaly and spina bifida. Evidence from many populations suggests that 50% of NTDs can be prevented through daily consumption of folic acid. A recent study has reported that folic acid may not protect populations of Mexican descent. This finding has serious implications for women living along the US-Mexico border. Not only is risk high in these Mexican American women compared with other US women; they also differ markedly in supplemental folic acid and dietary folate consumption, and in NTD-related risks (e.g., obesity, diabetes). This case-control study investigated whether folic acid supplements and dietary folate reduces NTDs in Mexican Americans. Cases included liveborn, stillborn, electively and spontaneously aborted NTD-affected fetuses and infants occurring in the 14-county Texas-Mexico border. Controls were randomly selected from unaffected live births, frequency matched to cases by hospital and year. An in-person interview of 110 case and 113 control mothers solicited data on folic acid supplements, dietary folate, and other covariates. Consumption of folic acid-containing vitamins before conception was only 5% for both case and control women. Taking vitamins the trimester before conception had no apparent effect, after adjusting for covariates [odds ratio (OR) = 1.0, 95% confidence interval (CI) = 0.3–3.4]. Combining folate from vitamins and diet showed a 20% risk reduction for women consuming at least 400 μg of folate daily [OR = 0.8, 95% CI = 0.5–1.5]; however, this estimate is statistically indistinguishable from the null. Although consistent with an inherent ineffectiveness of supplemental folic acid, that so few women consumed multivitamins during the critical time severely limited the assessment of folic acid in this population. A reduced folate response in Mexican descent women may be due to a genetic heterogeneity for metabolizing folate. Alternatively, folate intakes may be insufficient to overcome other underlying risk factors. In conclusion, determining whether folic acid reduces NTD risk in Mexican American women requires further study in populations with higher folic acid exposures. Meanwhile, we should pursue all recommended prevention strategies to reduce risk, including motivating Mexican American women of childbearing age to take folic acid routinely. ^

Preconceptional use of folic acid in the region of the Kantonsspital Münsterlingen/Thurgau: has it changed over the past 10 years?

BACKGROUND  Numerous studies have shown that the preconceptional use of folic acid prevents neural tube defects. We created a study to find out whether the preconceptional use of folic acid has improved in the past 10 years, in the area of Münsterlingen, Switzerland. MATERIAL AND METHODS  We interviewed 2 groups of patients who delivered at our Institution, namely between 2000 and 2002 (period A) involving 287 women and from 2009 to 2010 (period B) involving 305 pregnant women. We asked them whether they used folic acid by means of a standardised questionnaire. RESULTS  In period B significantly more women have taken folic acid preconceptionally (period A: 27.5% vs. period B: 40.7%; p=0.001). A significant increase in folic acid intake was seen in the German speaking group from period A to B (30.3% vs. 52.7%; p=0.0005), while this was not the case in the non-German speaking group (21.4% in both periods). More multiparaé women were taking folic acid compared to nulliparae. A significant increase from period A to B was noted only in the German speaking group. Unexpectedly, in nulliparae non-German speaking women, folic acid supplementation decreased from 14% to 6.1%. DISCUSSION  We have found a significant increase in preconceptional folic acid supplementation from 2001 to 2010. The percentage of women taking folic acid is disappointingly low in all groups, particularly in nulliparae women of non-German ethnicity.

Folic acid fortification, maternal obesity and neural tube defects: Policy implications

In 1996, the Food and Drug Administration (FDA) mandated that beginning in January 1998, flour and other enriched grain products be fortified with 140 μg of folic acid per 100 g of grain to prevent neural tube defects (NTDs) that occur in approximately 1 in 1,000 pregnancies in the United States (U.S.). Although this program has demonstrated important public health effects, it is argued that current fortification levels may not be enough to prevent all folic acid-preventable NTD cases. This study reviews published literature, on folic acid fortification in the U.S. and countries with mandatory folic acid fortification programs reported after 1992 and through January 2008. Published studies are evaluated to determine if the current level of folic acid fortification in the U.S. is adequate to prevent the most common forms of NTDs (spina bifida and anencephaly), particularly among overweight and obese women. ^ Although consistent improvement in blood folate levels of child bearing age women is reported in almost all studies, the RBC folate concentration has not reached the level associated with the most significant reduction of risk for NTDs (906 nmol/L); approximately half of the potentially preventable NTDs are prevented by fortification at the current U.S. level. Furthermore, the blood folate status of women in higher BMI categories (obese or overweight) has not improved as much as among women in lower BMI categories. Therefore, women classified as overweight or obese have not benefited from the preventive effects of folic acid fortification as much as normal or underweight women. ^ To reduce risk of folate preventable NTDs, especially in overweight and obese women, it may be necessary to increase the current level of folic acid fortification. However, further research is required to determine the optimal levels of fortification to achieve this goal without causing adverse health effects in the general population. ^

Homocysteine induces congenital defects of the heart and neural tube: Effect of folic acid

The biological basis or mechanism whereby folate supplementation protects against heart and neural tube defects is unknown. It has been hypothesized that the amino acid homocysteine may be the teratogenic agent, since serum homocysteine increases in folate depletion; however, this hypothesis has not been tested. In this study, avian embryos were treated directly with d,l-homocysteine or with l-homocysteine thiolactone, and a dose response was established. Of embryos treated with 50 μl of the teratogenic dose (200 mM d,l-homocysteine or 100 mM l-homocysteine thiolactone) on incubation days 0, 1, and 2 and harvested at 53 h (stage 14), 27% showed neural tube defects. To determine the effect of the teratogenic dose on the process of heart septation, embryos were treated during incubation days 2, 3, and 4; then they were harvested at day 9 following the completion of septation. Of surviving embryos, 23% showed ventricular septal defects, and 11% showed neural tube defects. A high percentage of the day 9 embryos also showed a ventral closure defect. The teratogenic dose was shown to raise serum homocysteine to over 150 nmol/ml, compared with a normal level of about 10 nmol/ml. Folate supplementation kept the rise in serum homocysteine to ≈45 nmol/ml, and prevented the teratogenic effect. These results support the hypothesis that homocysteine per se causes dysmorphogenesis of the heart and neural tube, as well as of the ventral wall.