We describe an improved method for the measurement of retinol in dried blood spots (DBS) on filter paper. Retinol in human DBS on filter paper was analyzed by normal phase HPLC after a simple extraction method. Retinol associated with its binding protein was eluted from the paper into aqueous solution facilitated by ultrasonic agitation. Retinol associated with retinol binding protein was denatured with acetonitrile, and then retinol was isolated in a single hexane extract and analyzed directly by HPLC. When analyzing DBS, the individual plasma volume of the spots was calculated by measuring the sodium content or by weighing the blood spots. The described method yielded low intra- and interassay variability (<6%), with sufficient sensitivity (detection limit, 0.1 micromol/L) and good recovery (97% spike). Compared with matching plasma samples, DBS retinol consistently decreased 18-23% during the 1st wk of storage. After 1 wk, retinol remained stable in the blood spots at 23 degrees C for >3 mo. In conclusion, the analysis of retinol in DBS by HPLC is comparable to retinol analysis in serum. The variability of the method was reduced by using sodium concentration to estimate sample volume. Collection of DBS for retinol analysis is appropriate under field conditions, where it is difficult to centrifuge or freeze blood samples.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1093/jn/132.2.318 | DOI Listing |
Am J Forensic Med Pathol
January 2025
From the Section of Legal Medicine, Department of Social Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.
Wischnewsky spots are disseminated, dark lesions in gastric mucosa reflecting hemorrhage associated with fatal hypothermia, and are a phenomenon well known to forensic pathologists. We applied luminol and leucomalachite green tests to formalin-fixed gastric mucosa with Wischnewsky spots in autopsy cases of hypothermia. Both luminol and leucomalachite green tests showed positive reactions.
View Article and Find Full Text PDFInt J Neonatal Screen
January 2025
Key Proteo, Inc., Seattle, WA 98122, USA.
For many genetic disorders, there are no specific metabolic biomarkers nor analytical methods suitable for newborn population screening, even where highly effective preemptive treatments are available. The direct measurement of signature peptides as a surrogate marker for the protein in dried blood spots (DBSs) has been shown to successfully identify patients with Wilson Disease (WD) and three life-threatening inborn errors of immunity, X-linked agammaglobulinemia (XLA), Wiskott-Aldrich syndrome (WAS), and adenosine deaminase deficiency (ADAD). A novel proteomic-based multiplex assay to detect these four conditions from DBS using high-throughput LC-MS/MS was developed and validated.
View Article and Find Full Text PDFInt J Neonatal Screen
December 2024
Division of Metabolic Diseases, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, 9718 GZ Groningen, The Netherlands.
The biomarker-based Dutch Newborn Screening (NBS) panel (as of 2024) comprises 19 inherited metabolic disorders (IMDs). With the use of next-generation sequencing (NGS) as a first-tier screen, NBS could expand to include IMDs that lack a reliable biochemical footprint in dried blood spots, while also reducing secondary findings. To be eligible for inclusion in NBS, an IMD needs to fulfill the Wilson and Jungner criteria, with treatability being one of the most important criteria.
View Article and Find Full Text PDFGenet Med
January 2025
Newborn Screening Ontario, Children's Hospital of Eastern Ontario, Ottawa, ON, Canada; Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa. Electronic address:
Purpose: Universal newborn hearing screening (UNHS) programs using audiometric techniques alone are limited in ability to detect non-congenital childhood permanent hearing loss (PHL). In 2019, Ontario launched universal newborn screening (NBS) for PHL risk factors: congenital cytomegalovirus (cCMV) and 22 common variants in GJB2 and SLC26A4. Here we describe our experience with genetic risk factor screening.
View Article and Find Full Text PDFMalar J
January 2025
West African Centre for Cell Biology of Infectious Pathogens, Accra University of Ghana, Volta Rd, Accra, Ghana.
Background: Malaria remains a leading cause of death worldwide, claiming over 600,000 lives each year. Over 90% of these deaths, mostly among children under 5 years, occur in sub-Saharan Africa and are caused by Plasmodium falciparum. The merozoites stage of the parasite, crucial for asexual development invade erythrocytes through ligand-receptor interactions.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!