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Frontiers in Medicine 2021Programs to prevent mother-to-child HIV transmission do not reduce the number of infants exposed during pregnancy and breastfeeding. HIV-exposed but uninfected children...
Programs to prevent mother-to-child HIV transmission do not reduce the number of infants exposed during pregnancy and breastfeeding. HIV-exposed but uninfected children (HEU) present higher risk of morbidity and mortality than HIV-unexposed and uninfected children (UU). In this line, the study of immune biomarkers in HIV could improve prediction of disease progression, allowing to diminish comorbidity risk. Dried blood specimens (DBS) are an alternative to serum for collecting and transporting samples in countries with limited infrastructure and especially interesting for groups such as pediatrics, where obtaining a high sample volume is challenging. This study explores the usefulness of DBS for immune profile monitoring in samples from 30 children under clinical follow-up in Kinshasa: 10 HIV-infected (HIV+), 10 HEU, and 10 UU. We have measured the gene expression levels of 12 immune and inflammatory markers (CD14, IL-6, TNFα, HVEM, B7.1, HIF-1α, Siglec-10, IRAK-M, CD163, B7H5, PD-L1, and Galectin-9) in DBS samples by reverse transcription of total RNA and RT-qPCR. Principal component analysis, Kruskal-Wallis test, and Mann-Whitney test were performed in order to study group differences. HIV+ children presented significantly higher levels of seven biomarkers (CD14, IL-6 HVEM, B7.1, Siglec-10, HIF-1α, and CD163) than the UU group. In HEU, we found seven biomarkers significantly elevated (CD14, IL-6, HVEM, B7.1, Siglec-10, HIF-1α, and IRAK-M) vs. UU. Six biomarkers (CD14, IL-6, HVEM, B7.1, Siglec-10, and HIF-1α) showed a significantly higher expression in both HIV+ and HEU vs. UU, with HVEM and CD14 being significantly overexpressed among HIV+ vs. HEU. Our data reveal the utility of DBS for immune response monitoring. Moreover, significant differences in specific biomarker expression across groups strongly suggest the effect of HIV infection and/or HIV exposure on these immune biomarkers' expressions.
PubMed: 34211989
DOI: 10.3389/fmed.2021.678850 -
Journal of Viral Hepatitis Apr 2015The entry of new all-oral direct acting antiviral therapy for hepatitis C provides an opportunity to scale up HCV care in low- and middle-income countries. In HIV, use... (Review)
Review
The entry of new all-oral direct acting antiviral therapy for hepatitis C provides an opportunity to scale up HCV care in low- and middle-income countries. In HIV, use of dried blood spots (DBS) has facilitated the diagnosis and management of HIV in resource-poor settings. DBS may be used in a similar way to facilitate diagnosis and management of HCV. Here, we present a systematic review of the literature of DBS for HCV RNA detection and genotyping. Using an a priori review protocol, three databases were searched for studies published up to August 2013 that reported the use of dried blood and serum spots in genotyping, detection and measurement of HCV RNA, as well as the rate of degradation of HCV RNA when stored in DBS at room temperature. Nine papers were eligible for inclusion; eight studied DBS and one dried serum. Two studies measured concordance between genotype and subtype determined by DBS and whole plasma and both found 100% concordance. Four studies measured endpoint detection limits of HCV RNA-positive samples by DBS and found positive predictive values of 100% down to 250, 334, 2500 and 24160 IU/mL. Two studies found deterioration of HCV RNA in DBS samples stored at room temperature, while two others failed to detect such deterioration. These results support the potential use of DBS for genotyping and HCV RNA detection. Studies of the use of DBS for HCV RNA viral load measurement and of the rate of degradation of HCV RNA when stored in DBS at ambient temperatures remain inconclusive.
Topics: Blood; Desiccation; Genotyping Techniques; Hepacivirus; Hepatitis C; Humans; RNA, Viral; Specimen Handling
PubMed: 25367722
DOI: 10.1111/jvh.12345 -
Cells Oct 2020Inborn errors of metabolism and diabetes share common derangements in analytes of metabolic networks that are tested for in newborn screening, usually performed 48-72 h... (Review)
Review
Inborn errors of metabolism and diabetes share common derangements in analytes of metabolic networks that are tested for in newborn screening, usually performed 48-72 h after birth. There is limited research examining the metabolic imprint of diabetes on newborn screening results. This paper aims to demonstrate the links between diabetes, biochemical genetics and newborn screening in investigating disease pathophysiology in diabetes, provide possible reasons for the lack of research in diabetes in newborn screening and offer recommendations on potential research areas. We performed a systematic search of the available literature from 1 April 1998 to 31 December 2018 involving newborn screening and diabetes using OVID, MEDLINE, Cochrane and the PROSPERO register, utilizing a modified extraction tool adapted from Cochrane. Eight studies were included after screening 1312 records. Five studies reanalyzed dried blood spots (DBS) on filter paper cards, and three studies utilized pre-existing results. The results of these studies and how they relate to cord blood studies, the use of cord blood versus newborn screening dried blood spots as a sample and considerations on newborn screening and diabetes research is further discussed. The timing of sampling of newborn screening allows insight into neonatal physiology in a catabolic state with minimal maternal and placental influence. This, combined with the wide coverage of newborn screening worldwide, may aid in our understanding of the origins of diabetes.
Topics: Blood Specimen Collection; Diabetes Mellitus; Dried Blood Spot Testing; Female; Fetal Blood; Humans; Infant, Newborn; Neonatal Screening; Pregnancy; Specimen Handling; Technology Assessment, Biomedical
PubMed: 33076340
DOI: 10.3390/cells9102299 -
Clinical Chemistry and Laboratory... Oct 2013The analysis of blood spotted and dried on a matrix (i.e., "dried blood spot" or DBS) has been used since the 1960s in clinical chemistry; mostly for neonatal screening.... (Review)
Review
The analysis of blood spotted and dried on a matrix (i.e., "dried blood spot" or DBS) has been used since the 1960s in clinical chemistry; mostly for neonatal screening. Since then, many clinical analytes, including nucleic acids, small molecules and lipids, have been successfully measured using DBS. Although this pre-analytical approach represents an interesting alternative to classical venous blood sampling, its routine use is limited. Here, we review the application of DBS technology in clinical chemistry, and evaluate its future role supported by new analytical methods such as mass spectrometry.
Topics: Adult; Blood Specimen Collection; Chromatography, Liquid; Clinical Enzyme Tests; Communicable Diseases; Dried Blood Spot Testing; Genetic Testing; Humans; Infant, Newborn; Mass Spectrometry; Metabolic Diseases; Polymerase Chain Reaction; Preservation, Biological
PubMed: 23740687
DOI: 10.1515/cclm-2013-0228 -
BioMed Research International 2016Objective. This study measured light transmission through enamel and dentin and the effect of exposed dentinal tubules to light propagation. Methods. Light attenuation... (Comparative Study)
Comparative Study
Objective. This study measured light transmission through enamel and dentin and the effect of exposed dentinal tubules to light propagation. Methods. Light attenuation through enamel and dentin layers of various thicknesses (1 mm, 2 mm, 3 mm, and 4 mm) was measured using specimens that were (1) moist and (2) air-dried (n = 5). Measurements were repeated after the specimens were treated with EDTA. Specimens were transilluminated with a light curing unit (maximum power output 1869 mW/cm(2)), and the mean irradiance power of transmitting light was measured. The transmission of light through teeth was studied using 10 extracted intact human incisors and premolars. Results. Transmitted light irradiance through 1 mm thick moist discs was 500 mW/cm(2) for enamel and 398 mW/cm(2) for dentin (p < 0.05). The increase of the specimen thickness decreased light transmission in all groups (p < 0.005), and moist specimens attenuated light less than air-dried specimens in all thicknesses (p < 0.05). EDTA treatment increased light transmission from 398 mW/cm(2) to 439 mW/cm(2) (1 mm dentin specimen thickness) (p < 0.05). Light transmission through intact premolar was 6.2 mW/cm(2) (average thickness 8.2 mm) and through incisor was 37.6 mW/cm(2) (average thickness 5.6 mm). Conclusion. Light transmission through enamel is greater than that through dentin, probably reflecting differences in refractive indices and extinction coefficients. Light transmission through enamel, dentin, and extracted teeth seemed to follow Beer-Lambert's law.
Topics: Absorption, Radiation; Air; Bicuspid; Dental Cements; Dental Enamel; Dentin; Desiccation; Edetic Acid; Humans; In Vitro Techniques; Light; Light-Curing of Dental Adhesives; Materials Testing; Refractometry; Scattering, Radiation; Water
PubMed: 27446954
DOI: 10.1155/2016/5713962 -
Journal of Virological Methods Nov 2018Commercially-available kits for HIV-1 detection include instructions for detecting HIV-1 in plasma and DBS, but don't support other specimen types. (Comparative Study)
Comparative Study
BACKGROUND
Commercially-available kits for HIV-1 detection include instructions for detecting HIV-1 in plasma and DBS, but don't support other specimen types.
OBJECTIVES
Show quantitative stability of HIV-1 total nucleic acid (TNA) in blood and improved HIV-1 detection in alternative specimen types.
STUDY DESIGN
Whole blood and DBS specimens, tested as part of an external quality assurance program for qualitative HIV-1 detection, were used to evaluated error rates (false negative [FN], false positive [FP] and indeterminant [IND] results) across assays (internally developed [IH], Roche Amplicor [RA], and Roche TaqMan Qual [TQ]) and specimen types (frozen whole blood [BLD], DBS and cell pellets [PEL]). A modified Roche TaqMan HIV-1 assay was used to quantify HIV-1 TNA.
RESULTS
Significantly higher error rates were noted in DBS across all of the assays (4% vs. 0% for DBS and PEL, IH, p = 0.005; 4% vs. 0.1% for DBS and PEL, RA, p < 0.001; 10% vs. 1% for DBS and PEL or BLD, TQ, p < 0.001). HIV TNA concentration is stable in BLD (day 1 vs. day 10, p = 0.39) and higher than DBS (p < 0.001).
CONCLUSIONS
Transporting refrigerated whole blood for centralized processing into alternative specimen types will improve the sensitivitiy of HIV-1 detection in samples with low virus loads.
Topics: Diagnostic Errors; HIV Infections; HIV-1; RNA, Viral; Sensitivity and Specificity; Specimen Handling
PubMed: 30125614
DOI: 10.1016/j.jviromet.2018.08.009 -
Journal of Pharmacological and... 2023Pharmacokinetic/pharmacodynamic modelling has emerged as a valuable technique for understanding drug exposure and response relationships in drug development....
INTRODUCTION
Pharmacokinetic/pharmacodynamic modelling has emerged as a valuable technique for understanding drug exposure and response relationships in drug development. Pharmacokinetic data are often obtained by taking multiple blood samples, which may disturb physiological parameters and complicate study designs. Wearable automatic blood sampling systems can improve this limitation by collecting dried blood samples at programmable time points without disrupting cardiovascular parameters. It is the objective of this study to evaluate the bioanalysis of DBS in comparison to conventional blood sampling techniques and to optimize the recovery of various compounds spiked into canine blood dried on filter paper tape.
METHODS
Incubated blood samples from Beagle dogs were spiked with 16 different compounds and half of the whole blood sample was centrifuged to obtain plasma. After the dried blood sample drops were dried, liquid chromatography-mass spectrometry methods were used to analyze the samples. The study explored different anticoagulants, sample preparation methods and technical approaches to best determine the compound concentrations in dried blood samples.
RESULTS
With the two anticoagulants tested and using the optimized sample preparation methods and technical approaches we employed, the bioanalysis of dried blood samples can provide equivalent results to conventional blood sampling techniques.
DISCUSSION
Automated blood sampling systems have the potential to provide increased numbers of blood samples, providing substantially more Pharmacokinetic data within safety pharmacology studies without disrupting physiological parameters. They can provide a viable alternative to traditional methods of obtaining blood for various other types of studies or analyses.
Topics: Animals; Dogs; Tandem Mass Spectrometry; Chromatography, Liquid; Blood Specimen Collection; Plasma; Anticoagulants
PubMed: 37482323
DOI: 10.1016/j.vascn.2023.107296 -
Scientific Reports Dec 2023Future lunar exploration will be based on in-situ resource utilization (ISRU) techniques. The most abundant raw material on the Moon is lunar regolith, which, however,...
Future lunar exploration will be based on in-situ resource utilization (ISRU) techniques. The most abundant raw material on the Moon is lunar regolith, which, however, is very scarce on Earth, making the study of simulants a necessity. The objective of this study is to characterize and investigate the sintering behavior of EAC-1A lunar regolith simulant. The characterization of the simulant included the determination of the phase assemblage, characteristic temperatures determination and water content analysis. The results are discussed in the context of sintering experiments of EAC-1A simulant, which showed that the material can be sintered to a relative density close to 90%, but only within a very narrow range of temperatures (20-30 °C). Sintering experiments were performed for sieved and unsieved, as well as for dried and non-dried specimens of EAC-1A. In addition, an analysis of the densification and mechanical properties of the sintered specimens was done. The sintering experiments at different temperatures showed that the finest fraction of sieved simulant can reach a higher maximum sintering temperature, and consequently a higher densification and biaxial strength. The non-dried powder exhibited higher densification and biaxial strength after sintering compared to the dried specimen. This difference was explained with a higher green density of the non-dried powder during pressing, rather than due to an actual influence on the sintering mechanism. Nevertheless, drying the powder prior to sintering is important to avoid the overestimation of the strength of specimens to be fabricated on the Moon.
PubMed: 38155314
DOI: 10.1038/s41598-023-50391-y -
BMC Infectious Diseases May 2022HIV-1 drug resistance genotyping is critical to the monitoring of antiretroviral treatment. Data on HIV-1 genotyping success rates of different laboratory specimen types...
BACKGROUND
HIV-1 drug resistance genotyping is critical to the monitoring of antiretroviral treatment. Data on HIV-1 genotyping success rates of different laboratory specimen types from multiple sources is still scarce.
METHODS
In this cross-sectional study, we determined the laboratory genotyping success rates (GSR) and assessed the correlates of genotyping failure of 6837 unpaired dried blood spot (DBS) and plasma specimens. Specimens from multiple studies in a resource-constrained setting were analysed in our laboratory between 2016 and 2019.
RESULTS
We noted an overall GSR of 65.7% and specific overall GSR for DBS and plasma of 49.8% and 85.9% respectively. The correlates of genotyping failure were viral load (VL) < 10,000 copies/mL (aOR 0.3 95% CI: 0.24-0.38; p < 0.0001), lack of viral load testing prior to genotyping (OR 0.85 95% CI: 0.77-0.94; p = 0.002), use of DBS specimens (aOR 0.10 95% CI: 0.08-0.14; p < 0.0001) and specimens from routine clinical diagnosis (aOR 1.4 95% CI: 1.10-1.75; p = 0.005).
CONCLUSIONS
We report rapidly decreasing HIV-1 genotyping success rates between 2016 and 2019 with increased use of DBS specimens for genotyping and note decreasing median viral loads over the years. We recommend improvement in DBS handling, pre-genotyping viral load testing to screen samples to enhance genotyping success and the development of more sensitive assays with well-designed primers to genotype specimens with low or undetectable viral load, especially in this era where virological suppression rates are rising due to increased antiretroviral therapy roll-out.
Topics: Cross-Sectional Studies; Drug Resistance; Drug Resistance, Viral; Genotype; HIV Infections; HIV Seropositivity; HIV-1; Humans; Specimen Handling; Viral Load
PubMed: 35581555
DOI: 10.1186/s12879-022-07453-9 -
PloS One 2016Plants kept as dried herbarium specimens share many characteristics with their living counterparts, but there are some substantial differences between them. Due to...
Plants kept as dried herbarium specimens share many characteristics with their living counterparts, but there are some substantial differences between them. Due to dehydration, leaves of herbarium specimens change not only their mass and colour, but in many cases change their dimensions, too. The present study aimed to determine whether leaf shape changes during the drying process. A total of 794 pairs of fresh and dried leaves or leaflets of 22 plant taxa were studied. The shape of the blades was quantified using elliptic Fourier analysis combined with principal component analysis. In addition, area and mass of the leaves were measured. Statistical tests were applied for comparing fresh and dried leaves. The results indicate that the preservation process of pressing and drying plants for herbarium purposes causes changes in leaf shape. In general, the shape changes were directional. As the shape of fresh and dried plants is different, it is strongly recommended that shape analyses should be performed on datasets containing either of the leaf types.
Topics: Plant Leaves; Plants; Principal Component Analysis
PubMed: 27045956
DOI: 10.1371/journal.pone.0153071