We describe a radioassay for cobalamin (vitamin B12) in human serum or plasma that requires no boiling or other pretreatment of the sample. Normal chicken serum covalently coupled to magnetizable particles is used as the binding agent. The assay is performed at pH 12.9, at which pH all cobalamin in human serum is released from its binding proteins, whereas the binding agent maintains a high affinity for cobalamin (Ka 1.7 x 10(10) L/mol). Under these assay conditions the binding protein shows a specificity for cobalamin similar to that of purified intrinsic factor. The assay is simple, rapid, and precise, and results correlate well with those of the Euglena gracilis microbiological assay and an intrinsic-factor binding assay.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Associations between Plasma Folate and Vitamin B, Blood Lead, and Bone Mineral Density among Adults and Elderly Who Received a Health Examination.
Nutrients
February 2022
Department of Public Health, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
This study hypothesized that plasma folate and vitamin B levels modified the association between blood lead and cadmium and total urinary arsenic levels and bone loss. A total of 447 study subjects who received a physical examination at the Wanfang Hospital Medical Center were recruited. Bone loss was defined as a calcaneus bone mineral density T-score less than -1.
View Article and Find Full Text PDFPlasma Vitamin B and Folate Alter the Association of Blood Lead and Cadmium and Total Urinary Arsenic Levels with Chronic Kidney Disease in a Taiwanese Population.
Nutrients
October 2021
Division of Nephrology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
Heavy metals causing chronic nephrotoxicity may play a key role in the pathogenesis of chronic kidney disease (CKD). This study hypothesized that plasma folate and vitamin B would modify the association of CKD with total urinary arsenic and blood lead and cadmium levels. We recruited 220 patients with CKD who had an estimated glomerular filtration rate of <60 mL/min/1.
View Article and Find Full Text PDFRefining Knowledge of Factors Affecting Vitamin B Concentration in Bovine Milk.
Animals (Basel)
February 2021
Regroupement FRQ-NT Op+Lait, 3200 rue Sicotte, Saint-Hyacinthe, QC J2S 2M2, Canada.
Article Synopsis
- Milk is a valuable source of vitamin B12, and ensuring a high concentration could improve its reputation as a health food.
- The study aimed to understand factors affecting B12 levels in cow milk, focusing on ruminal conditions and bedding types through two observational studies.
- Results showed that maintaining optimal ruminal conditions positively influenced milk B12 levels, while the type of bedding used for cows did not affect B12 concentrations in bulk tank milk.
Short communication: Potential prediction of vitamin B concentration based on mid-infrared spectral data using Holstein Dairy Herd Improvement milk samples.
J Dairy Sci
August 2020
Agriculture, Bio-Engineering, and Chemistry Department, Gembloux Agro-Bio Tech, University of Liège, 5030 Gembloux, Belgium.
The purpose of this study was (1) to predict the quantitative concentration of vitamin B in milk using mid-infrared (MIR) spectrometry, and (2) to evaluate the potential of MIR spectra to discriminate different clusters of records based on their B concentration. Milk samples were collected from 4,340 Holstein cows between 3 and 592 d in milk and located in 100 herds. Samples were taken using in-line milk meters and divided into 2 aliquots: one for MIR spectrometry and the other for B concentration reference analyses by radioassay.
View Article and Find Full Text PDFCombined effect of polymorphisms of MTHFR and MTR and arsenic methylation capacity on developmental delay in preschool children in Taiwan.
Arch Toxicol
June 2020
Department of Family Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
Polymorphisms of methylenetetrahydrofolate reductase (MTHFR) and methionine synthase (MTR) are related to cognitive dysfunction and mental disability. These genes, along with folate and vitamin B levels, are regulators of one-carbon metabolism, which synthesizes S-adenosylmethionine (SAM) as a methyl donor for arsenic methylation. The aim of this study was to explore whether polymorphisms of MTHFR and MTR influence arsenic methylation capacity and plasma folate and vitamin B levels and if these influences cause developmental delay in preschool children.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!