High sensitivity, contemporary and point-of-care cardiac troponin assays: educational aids developed by the IFCC Committee on Clinical Application of Cardiac Bio-Markers.

The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) formed a Task Force on the Application of Cardiac Bio-markers (TF-CB) in 2008, re-designated in 2018 as a committee (C-CB), to produce educational materials on cardiac biomarkers. Established in June 2017, definitive tables covering the majority of high-sensitivity, contemporary and point-of-care (POC) cTn assays have been developed by the C-CB and are available on the IFCC website. These tables provide extensive information about assays' analytical characteristics and encompass information on diagnostic discriminants, particularly the 99th percentiles, as provided by the manufacturers

Cardiac troponin and natriuretic peptide analytical interferences from hemolysis and biotin: educational aids from the IFCC Committee on Cardiac Biomarkers (IFCC C-CB).

Two interferences recently brought to the forefront as patient safety issues include hemolysis (hemoglobin) and biotin (vitamin B7). The International Federation for Clinical Chemistry Committee on Cardiac Biomarkers (IFCC-CB) obtained input from a majority of cTn and NP assay manufacturers to collate information related to high-sensitivity (hs)-cTnI, hs-cTnT, contemporary, and POC cTn assays, and NP assays interferences due to hemolysis and biotin. The information contained in these tables was designed as educational tools to aid laboratory professionals and clinicians in troubleshooting cardiac biomarker analytical results that are discordant with the clinical situation

Association between vitamin D insufficiency and tuberculosis in a vietnamese population

<p>Abstract</p> <p>Background</p> <p>Recent <it>in vitro </it>evidence suggests a link between vitamin D status and the risk of tuberculosis (TB). This study sought to examine the association between vitamin D status, parathyroid hormone (PTH) and the risk of TB in a Vietnamese population.</p> <p>Methods</p> <p>The study was designed as a matched case-control study, which involved 166 TB patients (113 men and 53 women), who were age-and-sex matched with 219 controls (113 men and 106 women). The average age of men and women was 49 and 50, respectively. TB was diagnosed by the presence of acid-fast bacilli on smears from sputum, and the isolation of <it>M. tuberculosis</it>. All patients were hospitalized for treatment in a TB specialist hospital. Controls were randomly drawn from the general community within the Ho Chi Minh, Vietnam. 25-hydroxyvitamin D [25(OH)D] and PTH was measured prior to treatment by an electrochemiluminescence immunoassay (ECLIA) on a Roche Elecsys. A serum level of 25(OH)D below 30 ng/mL was deemed to be vitamin D insufficient.</p> <p>Results</p> <p>The prevalence of vitamin D insufficiency was 35.4% in men with TB and 19.5% in controls (<it>P </it>= 0.01). In women, there were no significant differences in serum 25(OH)D and serum PTH levels between TB patients and controls. The prevalence of vitamin D insufficiency in women with TB (45.3%) was not significantly different from those without TB (47.6%; <it>P </it>= 0.91). However, in both genders, serum calcium levels in TB patients were significantly lower than in non-TB individuals. Smoking (odds ratio [OR] 1.25; 95% confidence interval [CI] 1.10 - 14.7), reduced 25(OH)D (OR per standard deviation [SD]: 1.14; 95% CI 1.07 - 10.7) and increased PTH (OR per SD 1.13; 95% CI 1.05 - 10.4) were independently associated with increased risk of TB in men.</p> <p>Conclusion</p> <p>These results suggest that vitamin D insufficiency was a risk factor for tuberculosis in men, but not in women. However, it remains to be established whether the association is a causal relationship.</p

The intertropical convergence zone modulates intense hurricane strikes on the western North Atlantic margin

© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Scientific Reports 6 (2016): 21728, doi:10.1038/srep21728Most Atlantic hurricanes form in the Main Development Region between 9°N to 20°N along the northern edge of the Intertropical Convergence Zone (ITCZ). Previous research has suggested that meridional shifts in the ITCZ position on geologic timescales can modulate hurricane activity, but continuous and long-term storm records are needed from multiple sites to assess this hypothesis. Here we present a 3000 year record of intense hurricane strikes in the northern Bahamas (Abaco Island) based on overwash deposits in a coastal sinkhole, which indicates that the ITCZ has likely helped modulate intense hurricane strikes on the western North Atlantic margin on millennial to centennial-scales. The new reconstruction closely matches a previous reconstruction from Puerto Rico, and documents a period of elevated intense hurricane activity on the western North Atlantic margin from 2500 to 1000 years ago when paleo precipitation proxies suggest that the ITCZ occupied a more northern position. Considering that anthropogenic warming is predicted to be focused in the northern hemisphere in the coming century, these results provide a prehistoric analog that an attendant northern ITCZ shift in the future may again return the western North Atlantic margin to an active hurricane interval.This research was supported by NSF Awards: OCE-1519578, OCE-1356708, BCS-1118340

Quantitative determination of vitamin D metabolites in plasma using UHPLC-MS/MS

Vitamin D is an important determinant of bone health at all ages. The plasma concentrations of 25-hydroxy vitamin D (25-OH D) and other metabolites are used as biomarkers for vitamin sufficiency and function. To allow for the simultaneous determination of five vitamin D metabolites, 25-OH D3, 25-OH D2, 24,25-(OH)2 D3, 1,25-(OH)2 D3, and 1,25-(OH)2 D2, in low volumes of human plasma, an assay using ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) was established. Plasma samples were spiked with isotope-labeled internal standards and pretreated using protein precipitation, solid-phase extraction (SPE) and a Diels–Alder derivatization step with 4-phenyl-1,2,4-triazoline-3,5-dione. The SPE recovery rates ranged from 55% to 85%, depending on the vitamin D metabolite; the total sample run time was <5 min. Mass spectrometry was conducted using positive ion electrospray ionization in the multiple reaction monitoring mode on a quadrupole–quadrupole-linear ion trap instrument after pre-column addition of methylamine to increase the ionization efficiency. The intra- and inter-day relative standard deviations were 1.6–4.1% and 3.7–6.8%, respectively. The limit of quantitation for these compounds was determined to be between 10 and 20 pg/mL. The 25-OH D results were compared with values obtained for reference materials (DEQAS). In addition, plasma samples were analyzed with two additional Diasorin antibody assays. All comparisons with conventional methods showed excellent correlations (r2 = 0.9738) for DEQAS samples, demonstrating the high degree of comparability of the new UHPLC-MS/MS technique to existing methods

Diurnally Entrained Anticipatory Behavior in Archaea

By sensing changes in one or few environmental factors biological systems can anticipate future changes in multiple factors over a wide range of time scales (daily to seasonal). This anticipatory behavior is important to the fitness of diverse species, and in context of the diurnal cycle it is overall typical of eukaryotes and some photoautotrophic bacteria but is yet to be observed in archaea. Here, we report the first observation of light-dark (LD)-entrained diurnal oscillatory transcription in up to 12% of all genes of a halophilic archaeon Halobacterium salinarum NRC-1. Significantly, the diurnally entrained transcription was observed under constant darkness after removal of the LD stimulus (free-running rhythms). The memory of diurnal entrainment was also associated with the synchronization of oxic and anoxic physiologies to the LD cycle. Our results suggest that under nutrient limited conditions halophilic archaea take advantage of the causal influence of sunlight (via temperature) on O2 diffusivity in a closed hypersaline environment to streamline their physiology and operate oxically during nighttime and anoxically during daytime

Dual clumped isotope thermometry resolves kinetic biases in carbonate formation temperatures

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Bajnai, D., Guo, W., Spötl, C., Coplen, T. B., Methner, K., Löffler, N., Krsnik, E., Gischler, E., Hansen, M., Henkel, D., Price, G. D., Raddatz, J., Scholz, D., & Fiebig, J. Dual clumped isotope thermometry resolves kinetic biases in carbonate formation temperatures. Nature Communications, 11(1), (2020): 4005, doi:10.1038/s41467-020-17501-0.Surface temperature is a fundamental parameter of Earth’s climate. Its evolution through time is commonly reconstructed using the oxygen isotope and the clumped isotope compositions of carbonate archives. However, reaction kinetics involved in the precipitation of carbonates can introduce inaccuracies in the derived temperatures. Here, we show that dual clumped isotope analyses, i.e., simultaneous ∆47 and ∆48 measurements on the single carbonate phase, can identify the origin and quantify the extent of these kinetic biases. Our results verify theoretical predictions and evidence that the isotopic disequilibrium commonly observed in speleothems and scleractinian coral skeletons is inherited from the dissolved inorganic carbon pool of their parent solutions. Further, we show that dual clumped isotope thermometry can achieve reliable palaeotemperature reconstructions, devoid of kinetic bias. Analysis of a belemnite rostrum implies that it precipitated near isotopic equilibrium and confirms the warmer-than-present temperatures during the Early Cretaceous at southern high latitudes.This work became possible through DFG grant “INST 161/871-1” and the Investment in Science Fund at Woods Hole Oceanographic Institution. The authors would like to thank Sven Hofmann and Manuel Schumann for their assistance in the joint Goethe University – Senckenberg BiK-F Stable Isotope Facility at the Institute of Geosciences, Goethe University Frankfurt. K.M. acknowledges funding through “DFG ME 4955/1-1”, E.K. through “DFG MU 2845/6-1”, D.S. through “DFG SCHO 1274/8-1” and “DFG SCHO 1274/11-1”, and M.H. through “DFG HA 8694/1-1”. C.S. acknowledges funding from the University of Innsbruck. A review of the manuscript by David Evans on behalf of the USGS is acknowledged

Cardiac Biomarkers and the Diagnosis of Myocardial Infarction in Women

PURPOSE OF REVIEW: Women with suspected acute coronary syndrome are less likely to undergo investigation or receive treatment than men, and women consistently have poorer outcomes. This review summarises how the latest development in cardiac biomarkers could improve both diagnosis and outcomes in women. RECENT FINDINGS: Novel high-sensitivity cardiac troponin assays have identified differences in the reference range and therefore diagnostic threshold for myocardial infarction in men and women. These differences are present across multiple populations with different ethnic backgrounds and for a range of assays. The use of a uniform threshold for cardiac troponin does not provide equivalent prediction in men and women, with lower thresholds needed for women to provide comparable risk stratification. SUMMARY: Sex differences in cardiac troponin concentrations are not widely recognised in clinical practice and may be contributing to the under-diagnosis of myocardial infarction in women and discrepancies in patient care and outcomes