583 research outputs found

    Validation of the physical working capacity at the fatigue threshold treadmill test

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    The purposes of the present study were twofold: 1) to determine the physical working capacity at the fatigue threshold (PWCFT) during an incremental treadmill test, and 2) to examine the validity of this fatigue threshold through constant-velocity runs to exhaustion at 90, 100, and 110% of the estimated PWCFT. Twelve aerobically-trained males (mean age±SD=24.6±5.4 years, running volume=69.9±46.0 km·wk-1, n=9) and females (22.3±2.3 years, 45.6±4.6 km·wk-1, n=3) volunteered to perform a treadmill test to exhaustion with electromyographic (EMG) signals recorded from the m. vastus lateralis on four separate visits. The First visit required each subject to complete an incremental treadmill test to exhaustion for determination of their PWCFT. During the second, third, and fourth visit, the subjects completed a treadmill run to exhaustion at a constant velocity that corresponded to 90, 100, or 110% of their PWCFT in random order. The linear regression analyses indicated there were no significant (p>.05) changes in muscle activation (i.e. EMG amplitude) across time to exhaustion during the constant velocity runs at 90% (60.00±0.00 min) and 100% (48.86±14.59 min) PWCFT, but significant (p<.05) increases occurred at 110% PWCFT (19.44±10.26 min). Thus, the findings of the present study indicated that the PWCFT treadmill test was able to accurately estimate the fastest running velocity that could be maintained for an extended period of time without evidence of neuromuscular fatigue

    Pharmaceutical integrated stress response enhancement protects oligodendrocytes and provides a potential multiple sclerosis therapeutic.

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    Oligodendrocyte death contributes to the pathogenesis of the inflammatory demyelinating disease multiple sclerosis (MS). Nevertheless, current MS therapies are mainly immunomodulatory and have demonstrated limited ability to inhibit MS progression. Protection of oligodendrocytes is therefore a desirable strategy for alleviating disease. Here we demonstrate that enhancement of the integrated stress response using the FDA-approved drug guanabenz increases oligodendrocyte survival in culture and prevents hypomyelination in cerebellar explants in the presence of interferon-γ, a pro-inflammatory cytokine implicated in MS pathogenesis. In vivo, guanabenz treatment protects against oligodendrocyte loss caused by CNS-specific expression of interferon-γ. In a mouse model of MS, experimental autoimmune encephalomyelitis, guanabenz alleviates clinical symptoms, which correlates with increased oligodendrocyte survival and diminished CNS CD4+ T cell accumulation. Moreover, guanabenz ameliorates relapse in relapsing-remitting experimental autoimmune encephalomyelitis. Our results provide support for a MS therapy that enhances the integrated stress response to protect oligodendrocytes against the inflammatory CNS environment

    TIGIT Marks Exhausted T Cells, Correlates with Disease Progression, and Serves as a Target for Immune Restoration in HIV and SIV Infection.

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    HIV infection induces phenotypic and functional changes to CD8+ T cells defined by the coordinated upregulation of a series of negative checkpoint receptors that eventually result in T cell exhaustion and failure to control viral replication. We report that effector CD8+ T cells during HIV infection in blood and SIV infection in lymphoid tissue exhibit higher levels of the negative checkpoint receptor TIGIT. Increased frequencies of TIGIT+ and TIGIT+ PD-1+ CD8+ T cells correlated with parameters of HIV and SIV disease progression. TIGIT remained elevated despite viral suppression in those with either pharmacological antiretroviral control or immunologically in elite controllers. HIV and SIV-specific CD8+ T cells were dysfunctional and expressed high levels of TIGIT and PD-1. Ex-vivo single or combinational antibody blockade of TIGIT and/or PD-L1 restored viral-specific CD8+ T cell effector responses. The frequency of TIGIT+ CD4+ T cells correlated with the CD4+ T cell total HIV DNA. These findings identify TIGIT as a novel marker of dysfunctional HIV-specific T cells and suggest TIGIT along with other checkpoint receptors may be novel curative HIV targets to reverse T cell exhaustion

    The regulation of miRNAs by reconstituted high-density lipoproteins in diabetes-impaired angiogenesis

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    Diabetic vascular complications are associated with impaired ischaemia-driven angiogenesis. We recently found that reconstituted high-density lipoproteins (rHDL) rescue diabetes-impaired angiogenesis. microRNAs (miRNAs) regulate angiogenesis and are transported within HDL to sites of injury/repair. The role of miRNAs in the rescue of diabetes-impaired angiogenesis by rHDL is unknown. Using a miRNA array, we found that rHDL inhibits hsa-miR-181c-5p expression in vitro and using a hsa-miR-181c-5p mimic and antimiR identify a novel anti-angiogenic role for miR-181c-5p. miRNA expression was tracked over time post-hindlimb ischaemic induction in diabetic mice. Early post-ischaemia when angiogenesis is important, rHDL suppressed hindlimb mmu-miR-181c-5p. mmu-miR-181c-5p was not detected in the plasma or within HDL, suggesting rHDL specifically targets mmu-miR-181c-5p at the ischaemic site. Three known angiogenic miRNAs (mmu-miR-223-3p, mmu-miR-27b-3p, mmu-miR-92a-3p) were elevated in the HDL fraction of diabetic rHDL-infused mice early post-ischaemia. This was accompanied by a decrease in plasma levels. Only mmu-miR-223-3p levels were elevated in the hindlimb 3 days post-ischaemia, indicating that rHDL regulates mmu-miR-223-3p in a time-dependent and site-specific manner. The early regulation of miRNAs, particularly miR-181c-5p, may underpin the rescue of diabetes-impaired angiogenesis by rHDL and has implications for the treatment of diabetes-related vascular complications

    Experimental infection of conventional nursing pigs and their dams with \u3ci\u3ePorcine deltacoronavirus\u3c/i\u3e

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    Porcine deltacoronavirus (PDCoV) is a newly identified virus that has been detected in swine herds of North America associated with enteric disease. The aim of this study was to demonstrate the pathogenicity, course of infection, virus kinetics, and aerosol transmission of PDCoV using 87 conventional piglets and their 9 dams, including aerosol and contact controls to emulate field conditions. Piglets 2–4 days of age and their dams were administered an oronasal PDCoV inoculum with a quantitative real-time reverse transcription (qRT)-PCR quantification cycle (Cq) value of 22 that was generated from a field sample having 100% nucleotide identity to USA/Illinois121/2014 determined by metagenomic sequencing and testing negative for other enteric disease agents using standard assays. Serial samples of blood, serum, oral fluids, nasal and fecal swabs, and tissues from sequential autopsy, conducted daily on days 1–8 and regular intervals thereafter, were collected throughout the 42-day study for qRT-PCR, histopathology, and immunohistochemistry. Diarrhea developed in all inoculated and contact control pigs, including dams, by 2 days post-inoculation (dpi) and in aerosol control pigs and dams by 3–4 dpi, with resolution occurring by 12 dpi. Mild to severe atrophic enteritis with PDCoV antigen staining was observed in the small intestine of affected piglets from 2 to 8 dpi. Mesenteric lymph node and small intestine were the primary sites of antigen detection by immunohistochemistry, and virus RNA was detected in these tissues to the end of the study. Virus RNA was detectable in piglet fecal swabs to 21 dpi, and dams to 14–35 dpi

    Predominant expression of Alzheimer’s disease-associated BIN1 in mature oligodendrocytes and localization to white matter tracts

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    BIN1 is not expressed in human brain microglial cells. (A) Immunohistochemical staining of adjacent sections of normal human brain cortex with antibodies against BIN1 or Iba1 reveals that BIN1 immunoreactive cells that are morphologically distinct from microglia. The boxed region is shown at a higher magnification on the right. (B) Single and two-color immunostaining of the human brain using antibodies against BIN1 and CD45 reveals that perivenular CD45-positive cells of the hematopoietic lineage do not express BIN1. (TIFF 4392 kb

    The INVEST project: investigating the use of evidence synthesis in the design and analysis of clinical trials.

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    BACKGROUND: When designing and analysing clinical trials, using previous relevant information, perhaps in the form of evidence syntheses, can reduce research waste. We conducted the INVEST (INVestigating the use of Evidence Synthesis in the design and analysis of clinical Trials) survey to summarise the current use of evidence synthesis in trial design and analysis, to capture opinions of trialists and methodologists on such use, and to understand any barriers. METHODS: Our sampling frame was all delegates attending the International Clinical Trials Methodology Conference in November 2015. Respondents were asked to indicate (1) their views on the use of evidence synthesis in trial design and analysis, (2) their own use during the past 10 years and (3) the three greatest barriers to use in practice. RESULTS: Of approximately 638 attendees of the conference, 106 (17%) completed the survey, half of whom were statisticians. Support was generally high for using a description of previous evidence, a systematic review or a meta-analysis in trial design. Generally, respondents did not seem to be using evidence syntheses as often as they felt they should. For example, only 50% (42/84 relevant respondents) had used a meta-analysis to inform whether a trial is needed compared with 74% (62/84) indicating that this is desirable. Only 6% (5/81 relevant respondents) had used a value of information analysis to inform sample size calculations versus 22% (18/81) indicating support for this. Surprisingly large numbers of participants indicated support for, and previous use of, evidence syntheses in trial analysis. For example, 79% (79/100) of respondents indicated that external information about the treatment effect should be used to inform aspects of the analysis. The greatest perceived barrier to using evidence synthesis methods in trial design or analysis was time constraints, followed by a belief that the new trial was the first in the area. CONCLUSIONS: Evidence syntheses can be resource-intensive, but their use in informing the design, conduct and analysis of clinical trials is widely considered desirable. We advocate additional research, training and investment in resources dedicated to ways in which evidence syntheses can be undertaken more efficiently, offering the potential for cost savings in the long term
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