270 research outputs found
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Longitudinal Monitoring of SARS-CoV-2 IgM and IgG Seropositivity to Detect COVID-19.
BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a novel beta-coronavirus that has recently emerged as the cause of the 2019 coronavirus pandemic (COVID-19). Polymerase chain reaction (PCR) based tests are optimal and recommended for the diagnosis of an acute SARS-CoV-2 infection. Serology tests for viral antibodies provide an important tool to diagnose previous exposure to the virus. Here we evaluate the analytical performance parameters of the Diazyme SARS-CoV-2 IgM/IgG serology assays and describe the kinetics of IgM and IgG seroconversion observed in patients with PCR-confirmed COVID-19 who were admitted to our hospital.MethodsWe validated the performance of the Diazyme assay in 235 presumed SARS-CoV-2 negative subjects to determine specificity. Subsequently, we evaluated the SARS-CoV-2 IgM and IgG seroconversion of 54 PCR-confirmed COVID-19 patients and determined sensitivity of the assay at three different timeframes.ResultSensitivity and specificity for detecting seropositivity at ≥15 days following a positive SARS-CoV-2 PCR result, was 100.0% and 98.7% when assaying for the panel of IgM and IgG. The median time to seropositivity observed for a reactive IgM and IgG result from the date of a positive PCR was 5 days (IQR: 2.75-9 days) and 4 days (IQR: 2.75-6.75 days), respectively.ConclusionsOur data demonstrate that the Diazyme IgM/IgG assays are suited for the purpose of detecting SARS-CoV-2 IgG and IgM in patients with suspected SARS-CoV-2 infections. For the first time, we report longitudinal data showing the evolution of seroconversion for both IgG and IgM in a cohort of acutely ill patients in the United States. We also demonstrate a low false positive rate in patients who were presumed to be disease free
Efforts to capture high amylose in rice
Screening of wild and cultivated rice in IRRI germplasm collection revealed that majority have intermediate apparent amylose content. It appears that ancient farmers selected rice based on texture of the lower amylose varieties, considering that the majority of rice consumers today prefer intermediate to soft-textured rice. Furthermore, 30% seems to be the natural upper natural limit of amylose levels in wild-type rice. If this is the case, the rich biodiversity of rice has been subjected to the bottleneck of domestication to select for grains that have superior cooking and eating but not nutritional or satiating qualities considering that the majority of rice consumers today eat rice three times a day. On the other hand, the amylose content of available rice mutants with deficient SBEIIb or an over-expressed GBSSI also revealed amylose levels of around 35% which is significantly lower by comparison with other high amylose cereals, whose amylose content ranges from 70–90%. Hence, to produce the high amylose phenotype in rice, one might need to target different sets of enzymes or regulatory pathways. Since increasing the amylose levels in rice might mean a concomitant increase in its resistant starch content and in its levels of satiety, and a decrease in its glycemic response, developing high amylose rice by biotechnology is imperative. This type of rice will be important not only in addressing the growing obesity epidemic which now also affects the developing countries but also as a basis of novel degradable biopolymers and for further elucidating the mechanisms of starch synthesis in the cereal endosperm. In this paper, we also present the status of our research project which aims to silence the expression of SBEIIa, SBEIIb and SSIIa singly or in combination using microRNA and RNAi silencing technologies with the aim of increasing the amylose levels in rice beyond its natural limits
An Examination of the Characteristics and Perceptions of School Resource Officers in Rural and Urban Oklahoma Schools
Fueled by concerns about school violence, the number of School Resource Officers (SROs) in the United States has soared. SROs are law enforcement officers who work in elementary and secondary schools and who are tasked to increase school safety. As of 2016, 48 percent of US public schools had SROs, compared to less than one percent in the 1970s, yet there are few studies that measure their effects. In particular, the literature largely ignores rural/urban differences. This study uses survey data from SROs working in public schools in Oklahoma to understand their roles and to determine if there are differences between rural and urban SROs. We look at jurisdiction and school characteristics as well as SRO perceptions of disciplinary practices, school climate, referrals, and community involvement. Identifying variability in these areas is a requisite first step in understanding the effect of the SRO on school safety
Human Chondrosarcoma Cells Acquire an Epithelial-Like Gene Expression Pattern via an Epigenetic Switch: Evidence for Mesenchymal-Epithelial Transition during Sarcomagenesis
Chondrocytes are mesenchymally derived cells that reportedly acquire some epithelial characteristics; however, whether this is a progression through a mesenchymal to epithelial transition (MET) during chondrosarcoma development is still a matter of investigation. We observed that chondrosarcoma cells acquired the expression of four epithelial markers, E-cadherin,desmocollin 3, maspin, and 14-3-3σ, all of which are governed epigenetically through cytosine methylation. Indeed, loss of cytosine methylation was tightly associated with acquired expression of both maspin and 14-3-3σ in chondrosarcomas. In contrast, chondrocyte cells were negative for maspin and 14-3-3σ and displayed nearly complete DNA methylation. Robust activation of these genes was also observed in chondrocyte cells following 5-aza-dC treatment. We also examined the transcription factor snail which has been reported to be an important mediator of epithelial to mesenchymal transitions (EMTs). In chondrosarcoma cells snail is downregulated suggesting a role for loss of snail expression in lineage maintenance. Taken together, these results document an epigenetic switch associated with an MET-like phenomenon that accompanies chondrosarcoma progression
The Ursinus Weekly, October 10, 1974
Gov. candidate Drew Lewis fields questions at U.C. • Achatz discusses news media role at Ursinus forum • Parents\u27 Day events slated • USGA continues action policy • Editorial: Ursinus was a people place • Pages from Ursinus past: Radical changes in store for Ursinus by year 1970! • Pumpkin eater\u27s greenery • Personals • A letter to the Weekly • Institute helps pre-meds abroad • Ursinus student publishes histories • Story leaks out • X-country defeated by King\u27s College • Bears will win Saturday! • Hockey team plans tour of Englandhttps://digitalcommons.ursinus.edu/weekly/1021/thumbnail.jp
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Calibrating from Within: Multipoint Internal Calibration of a Quantitative Mass Spectrometric Assay of Serum Methotrexate.
BACKGROUND:Clinical LC-MS/MS assays traditionally require that samples be run in batches with calibration curves in each batch. This approach is inefficient and presents a barrier to random access analysis. We developed an alternative approach called multipoint internal calibration (MPIC) that eliminated the need for batch-mode analysis. METHODS:The new approach used 4 variants of 13C-labeled methotrexate (0.026-10.3 µM) as an internal calibration curve within each sample. One site carried out a comprehensive validation, which included an evaluation of interferences and matrix effects, lower limit of quantification (LLOQ), and 20-day precision. Three sites evaluated assay precision and linearity. MPIC was also compared with traditional LC-MS/MS and an immunoassay. RESULTS:Recovery of spiked analyte was 93%-102%. The LLOQ was validated to be 0.017 µM. Total variability, determined in a 20-day experiment, was 11.5%CV. In a 5-day variability study performed at each site, total imprecision was 3.4 to 16.8%CV. Linearity was validated throughout the calibrator range (r2 > 0.995, slopes = 0.996-1.01). In comparing 40 samples run in each laboratory, the median interlaboratory imprecision was 6.55%CV. MPIC quantification was comparable to both traditional LC-MS/MS and immunoassay (r2 = 0.96-0.98, slopes = 1.04-1.06). Bland-Altman analysis of all comparisons showed biases rarely exceeding 20% when MTX concentrations were >0.4 µM. CONCLUSION:The MPIC method for serum methotrexate quantification was validated in a multisite proof-of-concept study and represents a big step toward random-access LC-MS/MS analysis, which could change the paradigm of mass spectrometry in the clinical laboratory
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Validation of a liquid chromatography tandem mass spectrometry (LC-MS/MS) method to detect cannabinoids in whole blood and breath.
Background The widespread availability of cannabis raises concerns regarding its effect on driving performance and operation of complex equipment. Currently, there are no established safe driving limits regarding ∆9-tetrahydrocannabinol (THC) concentrations in blood or breath. Daily cannabis users build up a large body burden of THC with residual excretion for days or weeks after the start of abstinence. Therefore, it is critical to have a sensitive and specific analytical assay that quantifies THC, the main psychoactive component of cannabis, and multiple metabolites to improve interpretation of cannabinoids in blood; some analytes may indicate recent use. Methods A liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed to quantify THC, cannabinol (CBN), cannabidiol (CBD), 11-hydroxy-THC (11-OH-THC), (±)-11-nor-9-carboxy-Δ9-THC (THCCOOH), (+)-11-nor-Δ9-THC-9-carboxylic acid glucuronide (THCCOOH-gluc), cannabigerol (CBG), and tetrahydrocannabivarin (THCV) in whole blood (WB). WB samples were prepared by solid-phase extraction (SPE) and quantified by LC-MS/MS. A rapid and simple method involving methanol elution of THC in breath collected in SensAbues® devices was optimized. Results Lower limits of quantification ranged from 0.5 to 2 μg/L in WB. An LLOQ of 80 pg/pad was achieved for THC concentrations in breath. Calibration curves were linear (R2>0.995) with calibrator concentrations within ±15% of their target and quality control (QC) bias and imprecision ≤15%. No major matrix effects or drug interferences were observed. Conclusions The methods were robust and adequately quantified cannabinoids in biological blood and breath samples. These methods will be used to identify cannabinoid concentrations in an upcoming study of the effects of cannabis on driving
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