5,649 research outputs found

    Hybrid Amperometric and Potentiometric Sensing Based on a CMOS ISFET Array

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    Potentiometry and amperometry are some of the most important techniques for electroanalytical applications. Integrating these two techniques on a single chip using CMOS technology paves the way for more analysis and measurement of chemical solutions. In this paper, we describe the integration of electrode transducers (amperometry) on an ion imager based on an ISFET array (potentiometry). In particular, this integration enables the spatial representation of the potential distribution of active electrodes in a chemical solution under investigation

    The diagnosis of severe combined immunodeficiency: Implementation of the PIDTC 2022 Definitions

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    BACKGROUND: Shearer et al in 2014 articulated well-defined criteria for the diagnosis and classification of severe combined immunodeficiency (SCID) as part of the Primary Immune Deficiency Treatment Consortium\u27s (PIDTC\u27s) prospective and retrospective studies of SCID. OBJECTIVE: Because of the advent of newborn screening for SCID and expanded availability of genetic sequencing, revision of the PIDTC 2014 Criteria was needed. METHODS: We developed and tested updated PIDTC 2022 SCID Definitions by analyzing 379 patients proposed for prospective enrollment into Protocol 6901, focusing on the ability to distinguish patients with various SCID subtypes. RESULTS: According to PIDTC 2022 Definitions, 18 of 353 patients eligible per 2014 Criteria were considered not to have SCID, whereas 11 of 26 patients ineligible per 2014 Criteria were determined to have SCID. Of note, very low numbers of autologous T cells (\u3c0.05 × 10 CONCLUSIONS: The PIDTC 2022 Definitions describe SCID and its subtypes more precisely than before, facilitating analyses of SCID characteristics and outcomes

    The Worldwide Alzheimer\u27s Disease Neuroimaging Initiative: ADNI-3 updates and global perspectives

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    The Worldwide Alzheimer\u27s Disease Neuroimaging Initiative (WW-ADNI) is a collaborative effort to investigate imaging and biofluid markers that can inform Alzheimer\u27s disease treatment trials. It is a public-private partnership that spans North America, Argentina, Australia, Canada, China, Japan, Korea, Mexico, and Taiwan. In 2004, ADNI researchers began a naturalistic, longitudinal study that continues today around the globe. Through several successive phases (ADNI-1, ADNI-GO, ADNI-2, and ADNI-3), the study has fueled amyloid and tau phenotyping and refined neuroimaging methodologies. WW-ADNI researchers have successfully standardized analyses and openly share data without embargo, providing a rich data set for other investigators. On August 26, 2020, the Alzheimer\u27s Association convened WW-ADNI researchers who shared updates from ADNI-3 and their vision for ADNI-4

    Trial of erythropoietin for hypoxic-ischemic encephalopathy in newborns

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    BACKGROUND: Neonatal hypoxic-ischemic encephalopathy is an important cause of death as well as long-term disability in survivors. Erythropoietin has been hypothesized to have neuroprotective effects in infants with hypoxic-ischemic encephalopathy, but its effects on neurodevelopmental outcomes when given in conjunction with therapeutic hypothermia are unknown. METHODS: In a multicenter, double-blind, randomized, placebo-controlled trial, we assigned 501 infants born at 36 weeks or more of gestation with moderate or severe hypoxic-ischemic encephalopathy to receive erythropoietin or placebo, in conjunction with standard therapeutic hypothermia. Erythropoietin (1000 U per kilogram of body weight) or saline placebo was administered intravenously within 26 hours after birth, as well as at 2, 3, 4, and 7 days of age. The primary outcome was death or neurodevelopmental impairment at 22 to 36 months of age. Neurodevelopmental impairment was defined as cerebral palsy, a Gross Motor Function Classification System level of at least 1 (on a scale of 0 [normal] to 5 [most impaired]), or a cognitive score of less than 90 (which corresponds to 0.67 SD below the mean, with higher scores indicating better performance) on the Bayley Scales of Infant and Toddler Development, third edition. RESULTS: Of 500 infants in the modified intention-to-treat analysis, 257 received erythropoietin and 243 received placebo. The incidence of death or neurodevelopmental impairment was 52.5% in the erythropoietin group and 49.5% in the placebo group (relative risk, 1.03; 95% confidence interval [CI], 0.86 to 1.24; P = 0.74). The mean number of serious adverse events per child was higher in the erythropoietin group than in the placebo group (0.86 vs. 0.67; relative risk, 1.26; 95% CI, 1.01 to 1.57). CONCLUSIONS: The administration of erythropoietin to newborns undergoing therapeutic hypothermia for hypoxic-ischemic encephalopathy did not result in a lower risk of death or neurodevelopmental impairment than placebo and was associated with a higher rate of serious adverse events. (Funded by the National Institute of Neurological Disorders and Stroke; ClinicalTrials.gov number, NCT02811263.)

    Development and Validation of a LC-MS/MS Assay for Quantification of Parathyroid Hormone (PTH 1-34) in human Plasma

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    Background: Teriparatide [recombinant human PTH (1-34)] is an osteoanabolic agent for treatment of osteoporosis. The effect on bone decreases the risk of vertebral and non-vertebral fractures and increases bone mineral density (BMD) in post-menopausal women with osteoporosis. Measurement of PTH (1-34) is valuable in assessing treatment response and concordance with therapy.Aim: To develop and validate a method for quantification of PTH (1-34) using Liquid chromatography tandem mass spectrometry (LC-MS/MS) and to perform comparison with a commercial immunoassay.  Method: Sample extraction was developed using a Waters (Milford, MA, USA) Oasis® HLB µElution solid phase extraction. Quantification m/z transition 589>656 was used on Waters/Micromass® Quattro Ultima™ Pt mass spectrometer to measure PTH (1-34) in human plasma using rat PTH (1-34) as internal standard. Validation criteria were carried out against industry standards. PTH (1-34) results obtained from human subjects given Teriparatide (Fortsteo, Eli Lilly, IN, USA) (n=390) were compared against results obtained from an immunoassay (IDS; Boldon Tyne and Wear. UK).  Results and Discussion: LC-MS/MS produced a linear calibration curve from 10 to 2000 pg/mL (r2 >0.990). The LLoQ and LLoD for PTH (1-34) were 10 pg/mL and 2.1 pg/mL respectively. The inter- /intra-assay precision (CV%) of the method were 98.3% for four QCs (20, 100, 200, and 800 pg/mL). The mean recovery of PTH (1-34) was 107.2%. Method comparison between the LC-MS/MS and immunoassay using human EDTA plasma samples showed a high correlation (r2 = 0.950). A concentration-dependent, negative bias of 35.5% was observed across the range of 0 – 800 pg/mL. The immunoassay showed a 7% cross reactivity to human PTH (1-84) and 44% to rat PTH (1-34), no interference was observed in the LC-MS/MS method. Matrix effect and cross reactivity to human PTH (1-84) in the immunoassay were the likely contributing factors to the bias between the methods. The oxidised form of PTH (1-34) does not interfere with our LC-MS/MS method.  Conclusion: Our LC-MS/MS method demonstrated linearity over the calibration range, good precision and accuracy, excellent analyte recovery, and negligible matrix effects. The method was successfully used for measurements of PTH (1-34) in rat and human plasma

    The fatal trajectory of pulmonary COVID-19 is driven by lobular ischemia and fibrotic remodelling

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    Background: COVID-19 is characterized by a heterogeneous clinical presentation, ranging from mild symptoms to severe courses of disease. 9-20% of hospitalized patients with severe lung disease die from COVID-19 and a substantial number of survivors develop long-COVID. Our objective was to provide comprehensive insights into the pathophysiology of severe COVID-19 and to identify liquid biomarkers for disease severity and therapy response. Methods: We studied a total of 85 lungs (n = 31 COVID autopsy samples; n = 7 influenza A autopsy samples; n = 18 interstitial lung disease explants; n = 24 healthy controls) using the highest resolution Synchrotron radiation-based hierarchical phase-contrast tomography, scanning electron microscopy of microvascular corrosion casts, immunohistochemistry, matrix-assisted laser desorption ionization mass spectrometry imaging, and analysis of mRNA expression and biological pathways. Plasma samples from all disease groups were used for liquid biomarker determination using ELISA. The anatomic/molecular data were analyzed as a function of patients' hospitalization time. Findings: The observed patchy/mosaic appearance of COVID-19 in conventional lung imaging resulted from microvascular occlusion and secondary lobular ischemia. The length of hospitalization was associated with increased intussusceptive angiogenesis. This was associated with enhanced angiogenic, and fibrotic gene expression demonstrated by molecular profiling and metabolomic analysis. Increased plasma fibrosis markers correlated with their pulmonary tissue transcript levels and predicted disease severity. Plasma analysis confirmed distinct fibrosis biomarkers (TSP2, GDF15, IGFBP7, Pro-C3) that predicted the fatal trajectory in COVID-19. Interpretation: Pulmonary severe COVID-19 is a consequence of secondary lobular microischemia and fibrotic remodelling, resulting in a distinctive form of fibrotic interstitial lung disease that contributes to long-COVID. Funding: This project was made possible by a number of funders. The full list can be found within the Declaration of interests / Acknowledgements section at the end of the manuscript

    Synthesis, Characterisation and Application of Polymeric Scale Inhibitors

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    Desalination of seawater by both the evaporation (e.g. multi stage flash, MSF) and membrane (e.g. reverse osmosis, RO) processes encounters difficulties with precipitation of sparingly soluble inorganic salts such as calcium carbonate (CaCO), magnesium hydroxide (Mg(OH)) and calcium sulfate (CaSO). These precipitate during the desalination process when their solubility product Ksp is exceeded. To control this scaling problem, several methods for scale prevention and control are used, such as acid and additive treatments. Scale inhibitors are chemical additives that have gained importance in controlling scale formation and/or deposition in recent decades. These are low molecular weight organic compounds, typically phosphonates, or polymers of molecular weight 1000-4000, typically containing carboxylate, sulfonate or phosphonate groups

    Inhibition of the hERG potassium channel by phenanthrene:a polycyclic aromatic hydrocarbon pollutant

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    The lipophilic polycyclic aromatic hydrocarbon (PAH) phenanthrene is relatively abundant in polluted air and water and can access and accumulate in human tissue. Phenanthrene has been reported to interact with cardiac ion channels in several fish species. This study was undertaken to investigate the ability of phenanthrene to interact with hERG (human Ether-à-go-go-Related Gene) encoded Kv11.1 K(+) channels, which play a central role in human ventricular repolarization. Pharmacological inhibition of hERG can be proarrhythmic. Whole-cell patch clamp recordings of hERG current (I(hERG)) were made from HEK293 cells expressing wild-type (WT) and mutant hERG channels. WT I(hERG1a) was inhibited by phenanthrene with an IC(50) of 17.6 ± 1.7 µM, whilst I(hERG1a/1b) exhibited an IC(50) of 1.8 ± 0.3 µM. WT I(hERG) block showed marked voltage and time dependence, indicative of dependence of inhibition on channel gating. The inhibitory effect of phenanthrene was markedly impaired by the attenuated inactivation N588K mutation. Remarkably, mutations of S6 domain aromatic amino acids (Y652, F656) in the canonical drug binding site did not impair the inhibitory action of phenanthrene; the Y652A mutation augmented I(hERG) block. In contrast, the F557L (S5) and M651A (S6) mutations impaired the ability of phenanthrene to inhibit I(hERG), as did the S624A mutation below the selectivity filter region. Computational docking using a cryo-EM derived hERG structure supported the mutagenesis data. Thus, phenanthrene acts as an inhibitor of the hERG K(+) channel by directly interacting with the channel, binding to a distinct site in the channel pore domain. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00018-021-03967-8
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