146 research outputs found

    High-throughput screening in larval zebrafish identifies novel potent sedative-hypnotics

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    BACKGROUND: Many general anesthetics were discovered empirically, but primary screens to find new sedative-hypnotics in drug libraries have not used animals, limiting the types of drugs discovered. The authors hypothesized that a sedative-hypnotic screening approach using zebrafish larvae responses to sensory stimuli would perform comparably to standard assays, and efficiently identify new active compounds. METHODS: The authors developed a binary outcome photomotor response assay for zebrafish larvae using a computerized system that tracked individual motions of up to 96 animals simultaneously. The assay was validated against tadpole loss of righting reflexes, using sedative-hypnotics of widely varying potencies that affect various molecular targets. A total of 374 representative compounds from a larger library were screened in zebrafish larvae for hypnotic activity at 10 µM. Molecular mechanisms of hits were explored in anesthetic-sensitive ion channels using electrophysiology, or in zebrafish using a specific reversal agent. RESULTS: Zebrafish larvae assays required far less drug, time, and effort than tadpoles. In validation experiments, zebrafish and tadpole screening for hypnotic activity agreed 100% (n = 11; P = 0.002), and potencies were very similar (Pearson correlation, r > 0.999). Two reversible and potent sedative-hypnotics were discovered in the library subset. CMLD003237 (EC50, ~11 µM) weakly modulated γ-aminobutyric acid type A receptors and inhibited neuronal nicotinic receptors. CMLD006025 (EC50, ~13 µM) inhibited both N-methyl-D-aspartate and neuronal nicotinic receptors. CONCLUSIONS: Photomotor response assays in zebrafish larvae are a mechanism-independent platform for high-throughput screening to identify novel sedative-hypnotics. The variety of chemotypes producing hypnosis is likely much larger than currently known.This work was supported by grants from Shanghai Jiaotong University School of Medicine, Shanghai, China, and the Chinese Medical Association, Beijing, China (both to Dr. Yang). The Department of Anesthesia, Critical Care and Pain Medicine of Massachusetts General Hospital, Boston, Massachusetts, supported this work through a Research Scholars Award and an Innovation Grant (both to Dr. Forman). Contributions to this research from the Boston University Center for Molecular Discovery, Boston, Massachusetts (to Drs. Porco, Brown, Schaus, and Xu, and to Mr. Trilles), were supported by a grant from the National Institutes of Health, Bethesda, Maryland (grant No. R24 GM111625). (Shanghai Jiaotong University School of Medicine, Shanghai, China; Chinese Medical Association, Beijing, China; Department of Anesthesia, Critical Care and Pain Medicine of Massachusetts General Hospital, Boston, Massachusetts; R24 GM111625 - National Institutes of Health, Bethesda, Maryland)Accepted manuscript2019-09-0

    Heterogeneity of ubiquitin pathology in frontotemporal lobar degeneration: classification and relation to clinical phenotype

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    We have investigated the extent and pattern of immunostaining for ubiquitin protein (UBQ) in 60 patients with frontotemporal lobar degeneration (FTLD) with ubiquitin-positive, tau-negative inclusions (FTLD-U), 37 of whom were ascertained in Manchester UK and 23 in Newcastle-Upon-Tyne, UK. There were three distinct histological patterns according to the form and distribution of the UBQ pathology. Histological type 1 was present in 19 patients (32%) and characterised by the presence of a moderate number, or numerous, UBQ immunoreactive neurites and intraneuronal cytoplasmic inclusions within layer II of the frontal and temporal cerebral cortex, and cytoplasmic inclusions within granule cells of the dentate gyrus; neuronal intranuclear inclusions (NII) of a “cat’s eye” or “lentiform” appearance were present in 17 of these patients. In histological type 2 (16 patients, 27%), UBQ neurites were predominantly, or exclusively, present with few intraneuronal cytoplasmic inclusions within layer II of the cerebral cortex, while in histological type 3 (25 patients, 42%), UBQ intraneuronal cytoplasmic inclusions either within the cortical layer II or in the granule cells of the dentate gyrus, with few or no UBQ neurites, were seen. In neither of these latter two groups were NII present. The influence of histological type on clinical phenotype was highly significant with type 1 histology being associated clinically with cases of frontotemporal dementia (FTD) or progressive non-fluent aphasia (PNFA), type 2 histology with semantic dementia (SD), and type 3 histology with FTD, or FTD and motor neurone disease (MND)

    Technology Requirements for a Square Meter, Arcsecond Resolution Telescope for X-Rays: The SMART-X Mission

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    Addressing the astrophysical problems of the 2020's requires sub-arcsecond x-ray imaging with square meter effective area. Such requirements can be derived, for example, by considering deep x-ray surveys to find the young black holes in the early universe (large redshifts) which will grow into the first super-massive black holes. We have envisioned a mission, the Square Meter Arcsecond Resolution Telescope for X-rays (SMART-X), based on adjustable x-ray optics technology, incorporating mirrors with the required small ratio of mass to collecting area. We are pursuing technology which achieves sub-arcsecond resolution by on-orbit adjustment via thin film piezoelectric "cells" deposited directly on the non-reflecting sides of thin, slumped glass. While SMART-X will also incorporate state-of-the-art x-ray cameras, the remaining spacecraft systems have no requirements more stringent than those which are well understood and proven on the current Chandra X-ray Observatory

    Fertility, gonadal and sexual function in survivors of testicular cancer

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    Modern treatments cure most testicular cancer patients, so an important goal is to minimise toxicity. Fertility and sexual functioning are key issues for patients. We have evaluated these outcomes in a cross-sectional study of long-term survivors of testicular cancer. In total, 680 patients treated between 1982 and 1992 completed the EORTC Qly-C-30(qc30) questionnaire, the associated testicular cancer specific module and a general health and fertility questionnaire. Patients have been subdivided according to treatment received: orchidectomy either alone (surveillance, S n=169), with chemotherapy (C, n=272), radiotherapy (R, n=158), or both chemotherapy and radiotherapy (C/RT n=81). In the surveillance group, 6% of patients had an elevated LH, 41% an elevated FSH and 11% a low (<10 nmol l−1) testosterone. Hormonal function deteriorated with additional treatment, but the effect in general was small. Low testosterone was more common in the C/RT group (37% P=0.006), FSH abnormalities were more common after chemotherapy (C 49%, C/RT 71% both P<0.005) and LH abnormalities after radiotherapy (11% P<0.01) and chemotherapy (10%, P<0.001). Baseline hormone data were available for 367 patients. After treatment, compared to baseline, patients receiving chemotherapy had significantly greater elevations of FSH (median rise of 6 (IQR 3–9.25) iu l−1 compared to 3 (IQR 1–5) iu l−1 for S; P<0.001) and a fall (compared to a rise in the surveillance group) in median testosterone levels (−2 (IQR −8.0 to −1.5) vs 1.0. (IQR −4.0–4.0) P<0.001). Patients with low testosterone (but not elevated FSH) had lower quality of life scores related to sexual functioning on the testicular cancer specific module and lower physical, social and role functioning on the EORTC Qly C-30. Patients with a low testosterone also had higher body mass index and blood pressure. Treatment was associated with reduction in sexual activity and patients receiving chemotherapy had more concerns about fathering children. In total, 207 (30%) patients reported attempting conception of whom 159 (77%) were successful and a further 10 patients were successful after infertility treatment with an overall success rate of 82%. There was a lower overall success rate after chemotherapy (C 71%; CRT 67% compared to S 85% (P=0.028)). Elevated FSH levels were associated with reduced fertility (normal FSH 91% vs elevated 68% P<0.001). In summary, gonadal dysfunction is common in patients with a history of testicular cancer even when managed by orchidectomy alone. Treatment with chemotherapy in particular can result in additional impairment. Gonadal dysfunction reduces quality of life and has an adverse effect on patient health. Most patients retain their fertility, but the risk of infertility is likely to be increased by chemotherapy. Screening for gonadal dysfunction should be considered in the follow-up of testicular cancer survivors

    Seladelpar efficacy and safety at 3 months in patients with primary biliary cholangitis: ENHANCE, a phase 3, randomized, placebo-controlled study

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    Background and Aims: ENHANCE was a phase 3 study that evaluated efficacy and safety of seladelpar, a selective peroxisome proliferator-activated receptor-δ (PPAR) agonist, versus placebo in patients with primary biliary cholangitis with inadequate response or intolerance to ursodeoxycholic acid (UDCA). Approach and Results: Patients were randomized 1:1:1 to oral seladelpar 5 mg (n=89), 10 mg (n=89), placebo (n=87) daily (with UDCA, as appropriate). Primary end point was a composite biochemical response [alkaline phosphatase (ALP) &lt; 1.67×upper limit of normal (ULN), ≥15% ALP decrease from baseline, and total bilirubin ≤ ULN] at month 12. Key secondary end points were ALP normalization at month 12 and change in pruritus numerical rating scale (NRS) at month 6 in patients with baseline score ≥4. Aminotransferases were assessed. ENHANCE was terminated early following an erroneous safety signal in a concurrent, NASH trial. While blinded, primary and secondary efficacy end points were amended to month 3. Significantly more patients receiving seladelpar met the primary end point (seladelpar 5 mg: 57.1%, 10 mg: 78.2%) versus placebo (12.5%) (p &lt; 0.0001). ALP normalization occurred in 5.4% (p=0.08) and 27.3% (p &lt; 0.0001) of patients receiving 5 and 10 mg seladelpar, respectively, versus 0% receiving placebo. Seladelpar 10 mg significantly reduced mean pruritus NRS versus placebo [10 mg: −3.14 (p=0.02); placebo: −1.55]. Alanine aminotransferase decreased significantly with seladelpar versus placebo [5 mg: 23.4% (p=0.0008); 10 mg: 16.7% (p=0.03); placebo: 4%]. There were no serious treatment-related adverse events. Conclusions: Patients with primary biliary cholangitis (PBC) with inadequate response or intolerance to UDCA who were treated with seladelpar 10 mg had significant improvements in liver biochemistry and pruritus. Seladelpar appeared safe and well tolerated

    Numerical modelling of a two-phase twin-screw expander for Trilateral Flash Cycle applications

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    This paper presents numerical investigations of a twin-screw expander for low grade (≤100°C) heat to power conversion applications based on the bottoming Trilateral Flash Cycle. After a thorough description of the modeling procedure, a first set of simulations shows the effect of different inlet qualities of the R245fa working fluid and of the revolution speed on the expander performance. In particular, at 3750 RPM and an inlet absolute pressure of 5 bar, the volumetric and adiabatic efficiencies will increase from 24.8% and 37.6% to 61.2% and 83.1% if the inlet quality in the intake duct of the expander increased from 0 to 0.1. To further assess the effects of inlet quality, inlet pressure and revolution speed on the expander performance, parametric analyses were carried out in the ranges 0-1 inlet quality, 5-10 bar pressure and 1500-6000RPM speed respectively. © 2018 The Author(s).European Union’s Horizon 2020 Research and Innovation Programme under grant agreement no. 680599, (ii) Innovate UK (project no. 61995-431253, (iii) Engineering and Physical Sciences Research Council UK (EPSRC), grant no. EP/P510294/1 and (iv) Research Councils UK (RCUK), grant no. EP/K011820/1
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