2,214 research outputs found

    Mesenteric Vascular Dysregulation and Intestinal Inflammation Accompanies Experimental Spinal Cord Injury

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    Cervical and high thoracic spinal cord injury (SCI) drastically impairs autonomic nervous system function. Individuals with SCI at thoracic spinal-level 5 (T5) or higher often present cardiovascular disorders that include resting systemic arterial hypotension. Gastrointestinal (GI) tissues are critically dependent upon adequate blood flow and even brief periods of visceral hypoxia triggers GI dysmotility. The aim of this study was to test the hypothesis that T3-SCI induces visceral hypoperfusion, diminished postprandial vascular reflexes and concomitant visceral inflammation. We measured in vivo systemic arterial blood pressure and superior mesenteric artery (SMA) and duodenal blood flow in anesthetized T3-SCI rats at 3 days and 3 weeks post-injury either fasted or following enteral feeding of a liquid mixed-nutrient meal (Ensure™). In separate cohorts of fasted T3-SCI rats, markers of intestinal inflammation were assayed by qRT-PCR. Our results show that T3-SCI rats displayed significantly reduced SMA blood flow under all experimental conditions (p\u3c0.05). Specifically, the anticipated elevation of SMA blood flow in response to duodenal nutrient infusion (postprandial hyperemia) was either delayed or absent after T3-SCI. The dysregulated SMA blood flow in acutely-injured T3-SCI rats coincides with abnormal intestinal morphology and elevation of inflammatory markers, all of which resolve after 3 weeks. Specifically, Icam1, Ccl2 (MCP-1) and Ccl3 (MIP-1α) were acutely elevated following T3-SCI. Our data suggest that arterial hypotension diminishes mesenteric blood flow necessary to meet mucosal demands at rest and during digestion. The resulting GI ischemia and low-grade inflammation may be an underlying pathology leading to GI dysfunction seen following acute T3-SCI

    How Insurers Competed in the Affordable Care Act's First Year

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    Prior to the Affordable Care Act (ACA), most states' individual health insurance markets were dominated by one or two insurance carriers that had little incentive to compete by providing efficient services. Instead, they competed mainly by screening and selecting people based on their risk of incurring high medical costs. One of the ACA's goals is to encourage carriers to participate in the health insurance marketplaces and to shift the focus from competing based on risk selection to processes that increase consumer value, like improving efficiency of services and quality of care. Focusing on six states—Arkansas, California, Connecticut, Maryland, Montana, and Texas—this brief looks at how carriers are competing in the new marketplaces, namely through cost-sharing and composition of provider networks

    Health Insurance Exchanges: Legal Issues

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    Health insurance exchanges (HIE) are entities that organize the market for health insurance by connecting small businesses and individuals into larger pools that spread the risk for insurance companies, while facilitating the availability, choice and purchase of private health insurance for the uninsured. While there are legal issues that warrant consideration under a federal, state, or private exchange framework, those issues are not insurmountable barriers to implementation

    Models for Metal Hydride Particle Shape, Packing, and Heat Transfer

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    A multiphysics modeling approach for heat conduction in metal hydride powders is presented, including particle shape distribution, size distribution, granular packing structure, and effective thermal conductivity. A statistical geometric model is presented that replicates features of particle size and shape distributions observed experimentally that result from cyclic hydride decreptitation. The quasi-static dense packing of a sample set of these particles is simulated via energy-based structural optimization methods. These particles jam (i.e., solidify) at a density (solid volume fraction) of 0.665+/-0.015 - higher than prior experimental estimates. Effective thermal conductivity of the jammed system is simulated and found to follow the behavior predicted by granular effective medium theory. Finally, a theory is presented that links the properties of bi-porous cohesive powders to the present systems based on recent experimental observations of jammed packings of fine powder. This theory produces quantitative experimental agreement with metal hydride powders of various compositions.Comment: 12 pages, 12 figures, 2 table

    The accuracy of anal Self- and Companion Exams among Sexual Minority Men and Transgender Women: a Prospective analysis

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    BACKGROUND: Squamous cell carcinoma of the anus (SCCA) annual incidence among sexual minority men with and without HIV is 85/100,000 and 19/100,000 persons, respectively, which is significantly higher than the overall incidence (2/100,000). Incidence may also be higher in transgender women. Since SCCA tumours average ≥30 mm at diagnosis, we assessed the accuracy of individuals to self-detect smaller anal abnormalities. METHODS: Using convenience sampling, the study enrolled sexual minority men and transgender women, aged 25-81 years, in Chicago, Illinois and Houston, Texas, USA, during 2020-2022. Individuals were taught the anal self-examination and anal companion examination (ASE/ACE). Then, a clinician performed a digital anal rectal examination (DARE) before participants conducted the ASE or ACE. The sensitivity, specificity and concordance of the ASE/ACE to detect an abnormality were measured along with factors associated with ASE/ACE and DARE concordance. FINDINGS: Among 714 enrolled individuals, the median age was 40 years (interquartile range, 32-54), 36.8% (259/703) were living with HIV, and 47.0% (334/710), 23.4% (166/710), and 23.0% (163/710) were non-Hispanic white, non-Hispanic Black, and Hispanic, respectively. A total of 94.1% (671/713) identified as cisgendered men, and 5.9% (42/713) as gender minorities. A total of 658 participants completed an ASE and 28 couples (56 partners) completed an ACE. Clinicians detected abnormalities in 34.3% (245/714) of individuals. The abnormalities were a median of 3 mm in diameter. Sensitivity and specificity of the ASE/ACE was 59.6% (95% CI 53.5-65.7%) and 80.2% (95% CI 76.6-83.8%), respectively. Overall concordance was 0.73 (95% CI 0.70-0.76) between ASE/ACE and DARE and increased with increasing anal canal lesion size (p = 0.02). Concordance was lower when participants were older and received ASE/ACE training from a lay person rather than a clinician. INTERPRETATION: Sexual minority men/transgender women may self-detect SCCA when malignant lesions are much smaller than the current mean dimension at presentation of ≥30 mm. FUNDING: National Cancer Institute

    Increased Oral Detection, but Decreased Intestinal Signaling for Fats in Mice Lacking Gut Microbiota

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    Germ-free (GF) mice lacking intestinal microbiota are significantly leaner than normal (NORM) control mice despite consuming more calories. The contribution of microbiota on the recognition and intake of fats is not known. Thus, we investigated the preference for, and acceptance of, fat emulsions in GF and NORM mice, and associated changes in lingual and intestinal fatty acid receptors, intestinal peptide content, and plasma levels of gut peptides. GF and NORM C57Bl/6J mice were given 48-h two-bottle access to water and increasing concentrations of intralipid emulsions. Gene expression of the lingual fatty acid translocase CD36 and protein expression of intestinal satiety peptides and fatty-acid receptors from isolated intestinal epithelial cells were determined. Differences in intestinal enteroendocrine cells along the length of the GI tract were quantified. Circulating plasma satiety peptides reflecting adiposity and biochemical parameters of fat metabolism were also examined. GF mice had an increased preference and intake of intralipid relative to NORM mice. This was associated with increased lingual CD36 (P<0.05) and decreased intestinal expression of fatty acid receptors GPR40 (P<0.0001), GPR41 (P<0.0001), GPR43 (P<0.05), and GPR120 (P<0.0001) and satiety peptides CCK (P<0.0001), PYY (P<0.001), and GLP-1 (P<0.001). GF mice had fewer enteroendocrine cells in the ileum (P<0.05), and more in the colon (P<0.05), relative to NORM controls. Finally, GF mice had lower levels of circulating leptin and ghrelin (P<0.001), and altered plasma lipid metabolic markers indicative of energy deficits. Increased preference and caloric intake from fats in GF mice are associated with increased oral receptors for fats coupled with broad and marked decreases in expression of intestinal satiety peptides and fatty-acid receptors

    Ecosystem Interactions Underlie the Spread of Avian Influenza A Viruses with Pandemic Potential

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    Despite evidence for avian influenza A virus (AIV) transmission between wild and domestic ecosystems, the roles of bird migration and poultry trade in the spread of viruses remain enigmatic. In this study, we integrate ecosystem interactions into a phylogeographic model to assess the contribution of wild and domestic hosts to AIV distribution and persistence. Analysis of globally sampled AIV datasets shows frequent two-way transmission between wild and domestic ecosystems. In general, viral flow from domestic to wild bird populations was restricted to within a geographic region. In contrast, spillover from wild to domestic populations occurred both within and between regions. Wild birds mediated long-distance dispersal at intercontinental scales whereas viral spread among poultry populations was a major driver of regional spread. Viral spread between poultry flocks frequently originated from persistent lineages circulating in regions of intensive poultry production. Our analysis of long-term surveillance data demonstrates that meaningful insights can be inferred from integrating ecosystem into phylogeographic reconstructions that may be consequential for pandemic preparedness and livestock protection.National Institutes of Health (U.S.) (NIH Centers for Excellence in Influenza Research and Surveillance (CEIRS, contract # HHSN266200700010C))National Institutes of Health (U.S.) (NIH Centers for Excellence in Influenza Research and Surveillance (CEIRS, contract # HHSN272201400008C))National Institutes of Health (U.S.) (NIH Centers for Excellence in Influenza Research and Surveillance (CEIRS, contract # HHSN272201400006C)

    Q/R site interactions with the M3 helix in GluK2 kainate receptor channels revealed by thermodynamic mutant cycles

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    RNA editing at the Q/R site near the apex of the pore loop of AMPA and kainate receptors controls a diverse array of channel properties, including ion selectivity and unitary conductance and susceptibility to inhibition by polyamines and cis-unsaturated fatty acids, as well as subunit assembly into tetramers and regulation by auxiliary subunits. How these different aspects of channel function are all determined by a single amino acid substitution remains poorly understood; however, several lines of evidence suggest that interaction between the pore helix (M2) and adjacent segments of the transmembrane inner (M3) and outer (M1) helices may be involved. In the present study, we have used double mutant cycle analysis to test for energetic coupling between the Q/R site residue and amino acid side chains along the M3 helix. Our results demonstrate interaction with several M3 locations and particularly strong coupling to substitution for L614 at the level of the central cavity. In this location, replacement with smaller side chains completely and selectively reverses the effect of fatty acids on gating of edited channels, converting strong inhibition of wild-type GluK2(R) to nearly 10-fold potentiation of GluK2(R) L614A

    Access to housing subsidies, housing status, drug use and HIV risk among low-income U.S. urban residents

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    <p>Abstract</p> <p>Background</p> <p>Much research has shown an association between homelessness and unstable housing and HIV risk but most has relied on relatively narrow definitions of housing status that preclude a deeper understanding of this relationship. Fewer studies have examined access to housing subsidies and supportive housing programs among low-income populations with different personal characteristics. This paper explores personal characteristics associated with access to housing subsidies and supportive housing, the relationship between personal characteristics and housing status, and the relationship between housing status and sexual risk behaviors among low-income urban residents.</p> <p>Methods</p> <p>Surveys were conducted with 392 low-income residents from Hartford and East Harford, Connecticut through a targeted sampling plan. We measured personal characteristics (income, education, use of crack, heroin, or cocaine in the last 6 months, receipt of welfare benefits, mental illness diagnosis, arrest, criminal conviction, longest prison term served, and self-reported HIV diagnosis); access to housing subsidies or supportive housing programs; current housing status; and sexual risk behaviors. To answer the aims above, we performed univariate analyses using Chi-square or 2-sided ANOVA's. Those with significance levels above (0.10) were included in multivariate analyses. We performed 2 separate multiple regressions to determine the effects of personal characteristics on access to housing subsidies and access to supportive housing respectively. We used multinomial main effects logistic regression to determine the effects of housing status on sexual risk behavior.</p> <p>Results</p> <p>Being HIV positive or having a mental illness predicted access to housing subsidies and supportive housing, while having a criminal conviction was not related to access to either housing subsidies or supportive housing. Drug use was associated with poorer housing statuses such as living on the street or in a shelter, or temporarily doubling up with friends, acquaintances or sex partners. Living with friends, acquaintances or sex partners was associated with greater sexual risk than those living on the street or in other stable housing situations.</p> <p>Conclusions</p> <p>Results suggest that providing low-income and supportive housing may be an effective structural HIV prevention intervention, but that the availability and accessibility of these programs must be increased.</p

    Global Outcome Assessment Life-long after stroke in young adults initiative-the GOAL initiative : study protocol and rationale of a multicentre retrospective individual patient data meta-analysis

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    Introduction Worldwide, 2 million patients aged 18-50 years suffer a stroke each year, and this number is increasing. Knowledge about global distribution of risk factors and aetiologies, and information about prognosis and optimal secondary prevention in young stroke patients are limited. This limits evidence-based treatment and hampers the provision of appropriate information regarding the causes of stroke, risk factors and prognosis of young stroke patients. Methods and analysis The Global Outcome Assessment Life-long after stroke in young adults (GOAL) initiative aims to perform a global individual patient data meta-analysis with existing data from young stroke cohorts worldwide. All patients aged 18-50 years with ischaemic stroke or intracerebral haemorrhage will be included. Outcomes will be the distribution of stroke aetiology and (vascular) risk factors, functional outcome after stroke, risk of recurrent vascular events and death and finally the use of secondary prevention. Subgroup analyses will be made based on age, gender, aetiology, ethnicity and climate of residence.Peer reviewe
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