Background: The risk of neural tube defects (NTDs) is significantly reduced by supplemental folic acid. NTD risk may be associated with impaired absorption of polyglutamyl folate, the primary form of naturally occurring food folate, and of folic acid in supplements or fortified food. Stable-isotope methods provide the specificity needed to test this hypothesis.
Objective: We determined whether women who had an NTD-affected pregnancy had a reduced ability compared with control women to absorb polyglutamyl folate relative to folic acid.
Design: Healthy, nonpregnant women with a history of an NTD-affected pregnancy (cases; n = 11) and control women (n = 11) were administered an oral dose containing a mixture of [(2)H]pteroylpentaglutamate ([(2)H(2)]PteGlu(5); 233 nmol) and [(13)C]pteroylmonoglutamate ([(13)C(5)]PteGlu(1); 567 nmol) after a 30-d saturation protocol (2 mg unlabeled folic acid/d). Relative extents of absorption were evaluated by urinary excretion of (2)H(2)- and (13)C(5)-labeled folates 48 h postdose.
Results: During the first 24 h postdose, cases excreted less (f1.gif" BORDER="0"> +/- SD) [(2)H(2)]PteGlu(5) (21 +/- 12% compared with 37 +/- 19%; P = 0.01) and [(13)C(5)]PteGlu(1) (17 +/- 8% compared with 31 +/- 14%; P = 0.007) than did controls. No significant differences between cases and controls were detected in the percentage of [(2)H(2)]PteGlu(5) or [(13)C(5)]PteGlu(1) excreted during the second 24 h postdose or when the data were averaged over 48 h. However, excretion of the [(2)H(2)]folates tended to be lower in cases than in controls over the 48-h period (33 +/- 13% compared with 45 +/- 26%; P = 0.21). A similar trend (P = 0.29) for lower excretion of [(13)C(5)]folates in cases was also observed (31 +/- 16% compared with 39 +/- 17%). The ratio of urinary [(2)H(2)]folates to [(13)C(5)]folates did not differ significantly between cases and controls.
Conclusion: These data suggest the need for a larger-scale study using stable-isotope methods to further investigate this hypothesis.
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http://dx.doi.org/10.1093/ajcn/72.1.154 | DOI Listing |
Ecotoxicol Environ Saf
January 2025
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China. Electronic address:
Honeybees, essential pollinators for maintaining biodiversity, are experiencing a sharp population decline, which has become a pressing environmental concern. Among the factors implicated in this decline, neonicotinoid pesticides, particularly those belonging to the fourth generation, have been the focus of extensive scrutiny due to their potential risks to honeybees. This study investigates the molecular basis of these risks by examining the binding interactions between Apis mellifera L.
View Article and Find Full Text PDFEcotoxicol Environ Saf
January 2025
Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, China. Electronic address:
Habitat fragmentation represents a multifaceted global conservation threat, exerting both direct and indirect effects on individual animals and communities. Reptiles, particularly smaller species with limited migratory abilities, are especially vulnerable to these changes. This study examines how small reptiles adapt their life history strategies in fragmented habitats and determines whether their responses are primarily due to phenotypic plasticity or genetic adaptation.
View Article and Find Full Text PDFAnimal
December 2024
School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland.
Exploitation of compensatory growth (CG) is a widely practised management strategy in beef production, especially under pastoral conditions due to its potential to reduce feed costs. The aim of this experiment was to evaluate the effect of nutritional restriction during backgrounding in Angus steers slaughtered at either similar age and/or similar BW on feed efficiency, body composition, carcass characteristics and meat quality attributes under either a forage or feedlot-based finishing diet. Eighty steers (BW: 444 ± 39 kg, age: 18 ± 1 months) were blocked and randomly assigned within block to either an optimal (0.
View Article and Find Full Text PDFEur J Radiol
January 2025
Department of Diagnostic and Interventional Radiology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, USA. Electronic address:
Purpose: To evaluate the feasibility of aortoiliac CT-Angiography (CTA) using dual-source photon-counting detector (PCD)-CT with minimal iodine dose.
Methods: This IRB-approved, single-center prospective study enrolled patients with indications for aortoiliac CTA from December 2022 to March 2023. All scans were performed using a first-generation dual-source PCD-CT.
Eur J Radiol
January 2025
Department of Medicine 3, Friedrich-Alexander-University Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany; Institute of Medical Physics, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany. Electronic address:
Objectives: Contrast agents are frequently administered in computed tomography (CT) scans used for opportunistic screening of osteoporosis. The objective of this study is to compare the impact of contrast-related bone mineral density (BMD) increase between phantom-based and internal CT calibration techniques.
Materials And Methods: Phantom-based and internal CT calibration techniques were used to determine trabecular BMD in 93 existing clinical CT scans of the lumbar spine of 34 subjects, scanned before and after administration of contrast agents.
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