218 research outputs found
The Guanine Nucleotide Exchange Factor ARNO mediates the activation of ARF and phospholipase D by insulin
BACKGROUND: Phospholipase D (PLD) is involved in many signaling pathways. In most systems, the activity of PLD is primarily regulated by the members of the ADP-Ribosylation Factor (ARF) family of GTPases, but the mechanism of activation of PLD and ARF by extracellular signals has not been fully established. Here we tested the hypothesis that ARF-guanine nucleotide exchange factors (ARF-GEFs) of the cytohesin/ARNO family mediate the activation of ARF and PLD by insulin. RESULTS: Wild type ARNO transiently transfected in HIRcB cells was translocated to the plasma membrane in an insulin-dependent manner and promoted the translocation of ARF to the membranes. ARNO mutants: ΔCC-ARNO and CC-ARNO were partially translocated to the membranes while ΔPH-ARNO and PH-ARNO could not be translocated to the membranes. Sec7 domain mutants of ARNO did not facilitate the ARF translocation. Overexpression of wild type ARNO significantly increased insulin-stimulated PLD activity, and mutations in the Sec7 and PH domains, or deletion of the PH or CC domains inhibited the effects of insulin. CONCLUSIONS: Small ARF-GEFs of the cytohesin/ARNO family mediate the activation of ARF and PLD by the insulin receptor
The risk of recurrent venous thromboembolism after discontinuation of anticoagulant therapy in patients with cancer-associated thrombosis:a systematic review and meta-analysis
Background: The optimal duration of anticoagulation in patients with active cancer and venous thromboembolism (VTE) is unknown. Current clinical guidelines advocate anticoagulant therapy for 3–6 months and to continue anticoagulant therapy for as long as the cancer is active. However, an adequate systematic review on the rate of recurrent VTE after discontinuation of anticoagulant therapy has not been performed. Methods: For this systemic review and meta-analysis, we searched Embase.com, Medline (Ovid), Web of Science, Cochrane Library, and Google Scholar, from database inception to February 16, 2023, for studies on anticoagulant therapy in patients with cancer and the recurrence of venous thromboembolism after discontinuation of this therapy. We included randomised controlled trials and cohort studies published in English that reported on patients who met the following: cancer and a first VTE, completed at least 3 months of anticoagulant therapy, were followed after discontinuation of anticoagulant therapy, and with symptomatic recurrent VTE as an outcome during follow-up. Study-level data were requested from study authors. The primary outcome was the rate of recurrent VTE after discontinuation of anticoagulant therapy. A Bayesian random-effects meta-analysis was used to estimate the rate of recurrent VTE per 100 person-years for the pooled studies at different time intervals after discontinuation of anticoagulation therapy. We also calculated the cumulative VTE recurrence rate at different time intervals. Forest plots were mapped and the results were summarized by the median and 95% credible interval (CIs). This study was registered with PROSPERO, CRD42021249060. Findings: Of 3856 studies identified in our search, 33 studies were identified for inclusion. After requesting study-level data, 14 studies involving 1922 patients with cancer-associated thrombosis were included. The pooled rate of recurrent VTE per 100 person-years after discontinuation of anticoagulant therapy was 14.6 events (95% credible interval 6.5–22.8) in the first three months, decreasing to 1.1 events (95% CI 0.3–2.1) in year 2–3, and 2.2 events (95% CI 0.0–4.4) in year 3–5 after discontinuation of anticoagulant therapy. The cumulative VTE recurrence rate was 28.3% (95% CI 15.6–39.6%) at 1 year; 31.1% (95% CI 16.5–43.8%) at 2 years; 31.9% (95% CI 16.8–45.0%) at 3 years; and 35.0% (95% CI 16.8–47.4%) at 5 years after discontinuation of anticoagulant therapy. Interpretation: This meta-analysis demonstrates a high rate of recurrent VTE over time after discontinuation of anticoagulant therapy in patients with cancer-associated thrombosis. Our results support the current clinical guidelines to continue anticoagulant therapy in patients with active cancer. Funding: Erasmus MC.</p
The risk of recurrent venous thromboembolism after discontinuation of anticoagulant therapy in patients with cancer-associated thrombosis:a systematic review and meta-analysis
Background: The optimal duration of anticoagulation in patients with active cancer and venous thromboembolism (VTE) is unknown. Current clinical guidelines advocate anticoagulant therapy for 3–6 months and to continue anticoagulant therapy for as long as the cancer is active. However, an adequate systematic review on the rate of recurrent VTE after discontinuation of anticoagulant therapy has not been performed. Methods: For this systemic review and meta-analysis, we searched Embase.com, Medline (Ovid), Web of Science, Cochrane Library, and Google Scholar, from database inception to February 16, 2023, for studies on anticoagulant therapy in patients with cancer and the recurrence of venous thromboembolism after discontinuation of this therapy. We included randomised controlled trials and cohort studies published in English that reported on patients who met the following: cancer and a first VTE, completed at least 3 months of anticoagulant therapy, were followed after discontinuation of anticoagulant therapy, and with symptomatic recurrent VTE as an outcome during follow-up. Study-level data were requested from study authors. The primary outcome was the rate of recurrent VTE after discontinuation of anticoagulant therapy. A Bayesian random-effects meta-analysis was used to estimate the rate of recurrent VTE per 100 person-years for the pooled studies at different time intervals after discontinuation of anticoagulation therapy. We also calculated the cumulative VTE recurrence rate at different time intervals. Forest plots were mapped and the results were summarized by the median and 95% credible interval (CIs). This study was registered with PROSPERO, CRD42021249060. Findings: Of 3856 studies identified in our search, 33 studies were identified for inclusion. After requesting study-level data, 14 studies involving 1922 patients with cancer-associated thrombosis were included. The pooled rate of recurrent VTE per 100 person-years after discontinuation of anticoagulant therapy was 14.6 events (95% credible interval 6.5–22.8) in the first three months, decreasing to 1.1 events (95% CI 0.3–2.1) in year 2–3, and 2.2 events (95% CI 0.0–4.4) in year 3–5 after discontinuation of anticoagulant therapy. The cumulative VTE recurrence rate was 28.3% (95% CI 15.6–39.6%) at 1 year; 31.1% (95% CI 16.5–43.8%) at 2 years; 31.9% (95% CI 16.8–45.0%) at 3 years; and 35.0% (95% CI 16.8–47.4%) at 5 years after discontinuation of anticoagulant therapy. Interpretation: This meta-analysis demonstrates a high rate of recurrent VTE over time after discontinuation of anticoagulant therapy in patients with cancer-associated thrombosis. Our results support the current clinical guidelines to continue anticoagulant therapy in patients with active cancer. Funding: Erasmus MC.</p
Novel Patient Cell-Based HTS Assay for Identification of Small Molecules for a Lysosomal Storage Disease
Small molecules have been identified as potential therapeutic agents for lysosomal storage diseases (LSDs), inherited metabolic disorders caused by defects in proteins that result in lysosome dysfunctional. Some small molecules function assisting the folding of mutant misfolded lysosomal enzymes that are otherwise degraded in ER-associated degradation. The ultimate result is the enhancement of the residual enzymatic activity of the deficient enzyme. Most of the high throughput screening (HTS) assays developed to identify these molecules are single-target biochemical assays. Here we describe a cell-based assay using patient cell lines to identify small molecules that enhance the residual arylsulfatase A (ASA) activity found in patients with metachromatic leukodystrophy (MLD), a progressive neurodegenerative LSD. In order to generate sufficient cell lines for a large scale HTS, primary cultured fibroblasts from MLD patients were transformed using SV40 large T antigen. These SV40 transformed (SV40t) cells showed to conserve biochemical characteristics of the primary cells. Using a specific colorimetric substrate para-nitrocatechol sulfate (pNCS), detectable ASA residual activity were observed in primary and SV40t fibroblasts from a MLD patient (ASA-I179S) cultured in multi-well plates. A robust fluorescence ASA assay was developed in high-density 1,536-well plates using the traditional colorimetric pNCS substrate, whose product (pNC) acts as “plate fluorescence quencher” in white solid-bottom plates. The quantitative cell-based HTS assay for ASA generated strong statistical parameters when tested against a diverse small molecule collection. This cell-based assay approach can be used for several other LSDs and genetic disorders, especially those that rely on colorimetric substrates which traditionally present low sensitivity for assay-miniaturization. In addition, the quantitative cell-based HTS assay here developed using patient cells creates an opportunity to identify therapeutic small molecules in a disease-cellular environment where potentially disrupted pathways are exposed and available as targets
Department of Animal Sciences research and reviews: beef and sheep
Relationship of a PCR-SSCP at the Bovine calpastatin locus with calpastatin activity and meat tenderness / H. Y. Chung, M. E. Davis, H. C. Hines, and D. M. Wulf -- Effects of calpain proteolysis and calpain genotypes on meat tenderness of angus bulls / H. Y. Chung, M. E. Davis, H. C. Hines, and D. M. Wulf -- Identification of genetic markers for growth and carcass traits in beef cattle / W. Ge, M. E. Davis, H. C. Hines, and K. M. Irvin -- Relationships of polymorphisms in the bovine leptin gene with differences in beef carcass traits / K. Tessanne, H. C. Hines, and M. E. Davis -- Effects of rate of gain during periods of restricted intake on performance and carcass characteristics in steers fed to achieve step-wise increases in rate of gain / J. E. Rossi and S. C. Loerch -- Effects of feeding regimen and days fed on performance and carcass characteristics of feedlot steers / J. E. Rossi, S. C. Loerch, S. J. Moeller, and J. P. Schoonmaker -- Effect of an accelerated finishing program on performance and carcass characteristics of early weaned bulls and steers / J. P. Schoonmaker, S. C. Loerch, F. L. Fluharty, T. B. Turner, S. J. Moeller and J. E. Rossi -- Yeast-mineral mixes and beef-cattle performance in fescue-based grazing systems: preliminary report / S. Boyles, W. Shriver, and D. Kobs -- Forage and animal evaluation of heifers at Indian Lake Hydrologic Unit CRP stocker grazing demonstration / S. L. Boyles, B. W. Stoll, and T. L. Dobbels -- Beef quality is every cattleman's business: education program / J. Yates and S. Boyles -- Effects of pelleted alfalfa and whole-shelled corn combinations on lamb growth and carcass characteristics / F. L. Fluharty -- Effects of feeding pelleted, ensiled, or a combination of pelleted and ensiled alfalfa on lamb growth and carcass characteristics / F. L. Fluharty, G. D. Lowe, and D. D. Clevenger -- Effects of corn silage vs. alfalfa haylage on lamb growth and carcass characteristics in forage-based finishing systems / F. L. Fluharty, G. D. Lowe, and D. D. Clevenger -- Effects of feed-delivery system and corn processing on lamb growth and carcass characteristics / F. L. Fluharty, G. D. Lowe, and D. D. Clevenger -- Effects of pen floor type and bedding on lamb growth and carcass characteristics / F. L. Fluharty, G. D. Lowe, and D. D. Clevenger -- A PCR-SSCP polymorphism detected in the 5' flanking region of the ovine IGF-I gene / A. Yilmaz, M. E. Davis, and H. C. Hine
Nicotine preloading for smoking cessation: the Preloading RCT
Background: Nicotine preloading means using nicotine replacement therapy prior to a quit date while
smoking normally. The aim is to reduce the drive to smoke, thereby reducing cravings for smoking after
quit day, which are the main cause of early relapse. A prior systematic review showed inconclusive and
heterogeneous evidence that preloading was effective and little evidence of the mechanism of action, with
no cost-effectiveness data.
Objectives: To assess (1) the effectiveness, safety and tolerability of nicotine preloading in a routine NHS
setting relative to usual care, (2) the mechanisms of the action of preloading and (3) the cost-effectiveness
of preloading.
Design: Open-label randomised controlled trial with examination of mediation and a cost-effectiveness
analysis.
Setting: NHS smoking cessation clinics.
Participants: People seeking help to stop smoking. Interventions: Nicotine preloading comprised wearing a 21 mg/24 hour nicotine patch for 4 weeks prior to quit date. In addition, minimal behavioural support was provided to explain the intervention rationale and to support adherence. In the comparator group, participants received equivalent behavioural support.
Randomisation was stratified by centre and concealed from investigators.
Main outcome measures: The primary outcome was 6-month prolonged abstinence assessed using the
Russell Standard. The secondary outcomes were 4-week and 12-month abstinence. Adverse events (AEs)
were assessed from baseline to 1 week after quit day. In a planned analysis, we adjusted for the use of
varenicline (Champix®; Pfizer Inc., New York, NY, USA) as post-cessation medication. Cost-effectiveness
analysis took a health-service perspective. The within-trial analysis assessed health-service costs during
the 13 months of trial enrolment relative to the previous 6 months comparing trial arms. The base case
was based on multiple imputation for missing cost data. We modelled long-term health outcomes of
smoking-related diseases using the European-study on Quantifying Utility of Investment in Protection
from Tobacco (EQUIPT) model.
Results: In total, 1792 people were eligible and were enrolled in the study, with 893 randomised to the
control group and 899 randomised to the intervention group. In the intervention group, 49 (5.5%) people
discontinued preloading prematurely and most others used it daily. The primary outcome, biochemically
validated 6-month abstinence, was achieved by 157 (17.5%) people in the intervention group and 129
(14.4%) people in the control group, a difference of 3.02 percentage points [95% confidence interval (CI)
–0.37 to 6.41 percentage points; odds ratio (OR) 1.25, 95% CI 0.97 to 1.62; p = 0.081]. Adjusted for use
of post-quit day varenicline, the OR was 1.34 (95% CI 1.03 to 1.73; p = 0.028). Secondary abstinence
outcomes were similar. The OR for the occurrence of serious AEs was 1.12 (95% CI 0.42 to 3.03).
Moderate-severity nausea occurred in an additional 4% of the preloading group compared with the
control group. There was evidence that reduced urges to smoke and reduced smoke inhalation mediated
the effect of preloading on abstinence. The incremental cost-effectiveness ratio at the 6-month follow-up
for preloading relative to control was £710 (95% CI –£13,674 to £23,205), but preloading was dominant
at 12 months and in the long term, with an 80% probability that it is cost saving.
Limitations: The open-label design could partially account for the mediation results. Outcome assessment
could not be blinded but was biochemically verified.
Conclusions: Use of nicotine-patch preloading for 4 weeks prior to attempting to stop smoking can
increase the proportion of people who stop successfully, but its benefit is undermined because it reduces
the use of varenicline after preloading. If this latter effect could be overcome, then nicotine preloading
appears to improve health and reduce health-service costs in the long term. Future work should determine
how to ensure that people using nicotine preloading opt to use varenicline as cessation medication.
Trial registration: Current Controlled Trials ISRCTN33031001.NIHR Health Technology Assessment programm
HIV-1 matrix protein p17 misfolding forms toxic amyloidogenic assemblies that induce neurocognitive disorders
© 2017 The Author(s). Human immunodeficiency virus type-1 (HIV-1)-Associated neurocognitive disorder (HAND) remains an important neurological manifestation that adversely affects a patient's quality of life. HIV-1 matrix protein p17 (p17) has been detected in autoptic brain tissue of HAND individuals who presented early with severe AIDS encephalopathy. We hypothesised that the ability of p17 to misfold may result in the generation of toxic assemblies in the brain and may be relevant for HAND pathogenesis. A multidisciplinary integrated approach has been applied to determine the ability of p17 to form soluble amyloidogenic assemblies in vitro. To provide new information into the potential pathogenic role of soluble p17 species in HAND, their toxicological capability was evaluated in vivo. In C. elegans, capable of recognising toxic assemblies of amyloidogenic proteins, p17 induces a specific toxic effect which can be counteracted by tetracyclines, drugs able to hinder the formation of large oligomers and consequently amyloid fibrils. The intrahippocampal injection of p17 in mice reduces their cognitive function and induces behavioral deficiencies. These findings offer a new way of thinking about the possible cause of neurodegeneration in HIV-1-seropositive patients, which engages the ability of p17 to form soluble toxic assemblies
Non-Standard Errors
In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants
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