Background: The concentration of 25-hydroxyvitamin D [25(OH)D] in serum has been designated the functional indicator of vitamin D (VitD) nutritional status. Unfortunately, variability among 25(OH)D assays limits clinician ability to monitor VitD status, supplementation, and toxicity.
Methods: We developed an HPLC method that selectively measures 25-hydroxyvitamin D2 [25(OH)D2] and D3 [25(OH)D3] and compared this assay with a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, a competitive protein-binding assay (CPBA) on the Nichols Advantage platform, and an RIA from Diasorin.
Results: For the new HPLC assay, between-run CVs were 2.6%-4.9% for 25(OH)D3 and 3.2%-13% for 25(OH)D2; recoveries were 95%-102%; and the assay was linear from 5 microg/L to at least 200 microg/L. Comparison data were as follows: for HPLC vs LC-MS/MS, y = 1.01x - 4.82 microg/L (Sy/x = 4.93 microg/L; r = 0.996) for 25(OH)D3, and y = 0.902x - 0.566 microg/L (Sy/x = 2.56 microg/L; r = 0.9965 for 25(OH)D2; for HPLC vs Diasorin RIA, y = 0.709x - 5.86 microg/L (Sy/x = 7.35 microg/L; r = 0.7509); and for HPLC vs Nichols Advantage CPBA, y = 1.00x - 3.60 microg/L (Sy/x = 32.7 microg/L; r = 0.6823).
Conclusions: The new HPLC method is reliable, robust, and has advantages compared with the Nichols Advantage CPBA and the Diasorin RIA. The Nichols Advantage CPBA overestimated or underestimated 25(OH)D concentrations predicated on the prevailing metabolite present in patients' sera.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1373/clinchem.2005.064956 | DOI Listing |
mBio
November 2024
Department of Medicine, University of Connecticut Health, Farmington, Connecticut, USA.
Hum Brain Mapp
December 2024
Department of Psychiatry and Behavioral Sciences, University of Texas, Health Science Center Houston, Houston, Texas, USA.
National and international biobanking efforts led to the collection of large and inclusive imaging genetics datasets that enable examination of the contribution of genetic and environmental factors to human brains in illness and health. High-resolution neuroimaging (~10 voxels) and genetic (10 single nucleotide polymorphic [SNP] variants) data are available in statistically powerful (N = 10) epidemiological and disorder-focused samples. Performing imaging genetics analyses at full resolution afforded in these datasets is a formidable computational task even under the assumption of unrelatedness among the subjects.
View Article and Find Full Text PDFbioRxiv
October 2024
Department of Medicine, University of Connecticut Health, Farmington, CT, USA.
Syphilis is a sexually transmitted infection caused by the highly invasive and immunoevasive spirochetal pathogen subsp. (). Untreated syphilis can lead to infection of multiple organ systems, including the central nervous system.
View Article and Find Full Text PDFCancer Screen Prev
June 2024
Department of Primary Dental Care, School of Dentistry, University of Minnesota, Minneapolis, MN, USA.
Human papillomavirus (HPV)-related oropharyngeal cancers associated with sexual contact are increasing, with high rates in men who have sex with men. HPV-related cancers have the advantage of being frequently detectable through oropharyngeal visual examination and having much higher survival rates than classic oropharyngeal cancers. It has been demonstrated that gay and bisexual men can take smartphone oropharyngeal "selfies" of sufficient quality for screening.
View Article and Find Full Text PDFAlzheimers Dement
October 2024
Center for Economic and Social Research, University of Southern California, Los Angeles, California, USA.
Introduction: The Health and Retirement Study International Partner Surveys (HRS IPS) have rich longitudinal data, but the brevity of cognitive batteries is a limitation.
Methods: We used data from a substudy of the English Longitudinal Study of Ageing (ELSA) administering detailed cognitive assessments with the Harmonized Cognitive Assessment Protocol (ELSA-HCAP) (N = 1273) to inform approaches for estimating cognition in ELSA (N = 11,213). We compared two novel approaches: confirmatory factor analysis (CFA)- and regression-based prediction.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!