2,299 research outputs found

    The effect of exogenous corticosterone on West Nile virus infection in Northern Cardinals (Cardinalis cardinalis)

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    The relationship between stress and disease is thought to be unambiguous: chronic stress induces immunosuppression, which likely increases the risk of infection. However, this link has not been firmly established in wild animals, particularly whether stress hormones affect host responses to zoonotic pathogens, which can be transmitted to domesticated animal, wildlife and human populations. Due to the dynamic effects of stress hormones on immune functions, stress hormones may make hosts better or poorer amplifying hosts for a pathogen contingent on context and the host species evaluated. Using an important zoonotic pathogen, West Nile virus (WNV) and a competent host, the Northern Cardinal (Cardinalis cardinalis), we tested the effects of exogenous corticosterone on response to WNV infection. Corticosterone was administered at levels that individuals enduring chronic stressors (i.e., long-term inclement weather, food shortage, anthropogenic pollution) might experience in the wild. Corticosterone greatly impacted mortality: half of the corticosterone-implanted cardinals died between five - 11 days post-inoculation whereas only one of nine empty-implanted (control) birds died. No differences were found in viral titer between corticosterone- and empty-implanted birds. However, cardinals that survived infections had significantly higher average body temperatures during peak infection than individuals that died. In sum, this study indicates that elevated corticosterone could affect the survival of WNV-infected wild birds, suggesting that populations may be disproportionately at-risk to disease in stressful environments

    Peripherally acting mu-opioid antagonist for the treatment of opioid-induced constipation: Systematic review and meta-analysis

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    Background and Aim Opioid-induced constipation (OIC) is a frequent adverse event (AE) that impairs patients' quality of life (QOL). Peripherally acting mu-opioid receptor antagonists (PAMORAs) have been recognized as a treatment option for OIC, but the effect consistent across the studies has not been evaluated. Methods We conducted a quantitative meta-analysis to explore the efficacy of PAMORA for OIC (registered with PROSPERO: CRD42018085298). We systematically searched randomized controlled trials (RCTs) in Medline, Embase, and Central databases. Change from baseline in spontaneous bowel movements, pooled proportion of responders, QOL, and AEs were calculated and compared with results in placebo cases. Results We included 31 RCTs with 7849 patients. A meta-analysis revealed that patients under PAMORA therapy had considerably improved spontaneous bowel movement from baseline compared with those given placebo (20 RCTs; mean difference, 1.43; 95% confidence interval [CI], 1.18-1.68; n = 5622) and more responded (21 RCTs; risk ratio [RR], 1.81; 95% CI, 1.55-2.12; n = 4821). Moreover, QOL of patients receiving PAMORA was significantly better (8 RCTs; mean difference, -0.22; 95% CI, -0.28 to -0.17; n = 2884). AEs were increased significantly in the PAMORA group (26 RCTs; RR, 1.10; 95% CI, 1.06-1.15; n = 7715), especially in gastrointestinal disorders, whereas serious AEs were not significant (17 RCTs; RR, 1.04; 95% CI, 0.85-1.28; n = 5890). Conclusion Peripherally acting mu-opioid receptor antagonist has been shown to be effective and durable for patients with OIC and is the only drug with confirmed evidence in meta-analysis. The possibility of publication bias was the limitation of this study.ArticleJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY.34(5):818-829(2019)journal articl

    Neutron Scattering and Its Application to Strongly Correlated Systems

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    Neutron scattering is a powerful probe of strongly correlated systems. It can directly detect common phenomena such as magnetic order, and can be used to determine the coupling between magnetic moments through measurements of the spin-wave dispersions. In the absence of magnetic order, one can detect diffuse scattering and dynamic correlations. Neutrons are also sensitive to the arrangement of atoms in a solid (crystal structure) and lattice dynamics (phonons). In this chapter, we provide an introduction to neutrons and neutron sources. The neutron scattering cross section is described and formulas are given for nuclear diffraction, phonon scattering, magnetic diffraction, and magnon scattering. As an experimental example, we describe measurements of antiferromagnetic order, spin dynamics, and their evolution in the La(2-x)Ba(x)CuO(4) family of high-temperature superconductors.Comment: 31 pages, chapter for "Strongly Correlated Systems: Experimental Techniques", edited by A. Avella and F. Mancin

    Reference Ranges for Bone Mineral Density and Prevalence of Osteoporosis in Vietnamese Men and Women

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to examine the effect of different reference ranges in bone mineral density on the diagnosis of osteoporosis.</p> <p>Methods</p> <p>This cross-sectional study involved 357 men and 870 women aged between 18 and 89 years, who were randomly sampled from various districts within Ho Chi Minh City, Vietnam. BMD at the femoral neck, lumbar spine and whole body was measured by DXA (Hologic QDR4500). Polynomial regression models and bootstraps method were used to determine peak BMD and standard deviation (<it>SD</it>). Based on the two parameters, we computed T-scores (denoted by <it>T</it><sub>VN</sub>) for each individual in the study. A similar diagnosis was also done based on T-scores provided by the densitometer (<it>T</it><sub>DXA</sub>), which is based on the US White population (NHANES III). We then compared the concordance between <it>T</it><sub>VN </sub>and <it>T</it><sub>DXA </sub>in the classification of osteoporosis. Osteoporosis was defined according to the World Health Organization criteria.</p> <p>Results</p> <p>In post-menopausal women, the prevalence of osteoporosis based on femoral neck <it>T</it><sub>VN </sub>was 29%, but when the diagnosis was based on <it>T</it><sub>DXA</sub>, the prevalence was 44%. In men aged 50+ years, the <it>T</it><sub>VN</sub>-based prevalence of osteoporosis was 10%, which was lower than <it>T</it><sub>DXA</sub>-based prevalence (30%). Among 177 women who were diagnosed with osteoporosis by <it>T</it><sub>DXA</sub>, 35% were actually osteopenia by <it>T</it><sub>VN</sub>. The kappa-statistic was 0.54 for women and 0.41 for men.</p> <p>Conclusion</p> <p>These data suggest that the <it>T-</it>scores provided by the Hologic QDR4500 over-diagnosed osteoporosis in Vietnamese men and women. This over-diagnosis could lead to over-treatment and influence the decision of recruitment of participants in clinical trials.</p

    Improved Resolution Haplogroup G Phylogeny in the Y Chromosome, Revealed by a Set of Newly Characterized SNPs

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    Background: Y-SNP haplogroup G (hgG), defined by Y-SNP marker M201, is relatively uncommon in the United States general population, with only 8 additional sub-markers characterized. Many of the previously described eight sub-markers are either very rare (2–4%) or do not distinguish between major populations within this hg. In fact, prior to the current study, only 2 % of our reference Caucasian population belonged to hgG and all of these individuals were in sub-haplogroup G2a, defined by P15. Additional Y-SNPs are needed in order to differentiate between individuals within this haplogroup. Principal Findings: In this work we have investigated whether we could differentiate between a population of 63 hgG individuals using previously uncharacterized Y-SNPs. We have designed assays to test these individuals using all known hgG SNPs (n = 9) and an additional 16 unreported/undefined Y-SNPS. Using a combination of DNA sequence and genetic genealogy databases, we have uncovered a total of 15 new hgG SNPs that had been previously reported but not phylogenetically characterized. Ten of the new Y-SNPs are phylogenetically equivalent to M201, one is equivalent to P15 and, interestingly, four create new, separate haplogroups. Three of the latter are more common than many of the previously defined Y-SNPs. Y-STR data from these individuals show that DYS385*12 is present in (70%) of G2a3b1-U13 individuals while only 4 % of non-G2a3b1-U13 individuals posses the DYS385*12 allele. Conclusions: This study uncovered several previously undefined Y-SNPs by using data from several database sources. Th

    Redundant and Specific Roles of the ARGONAUTE Proteins AGO1 and ZLL in Development and Small RNA-Directed Gene Silencing

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    The Arabidopsis ARGONAUTE1 (AGO1) and ZWILLE/PINHEAD/AGO10 (ZLL) proteins act in the miRNA and siRNA pathways and are essential for multiple processes in development. Here, we analyze what determines common and specific function of both proteins. Analysis of ago1 mutants with partially compromised AGO1 activity revealed that loss of ZLL function re-establishes both siRNA and miRNA pathways for a subset of AGO1 target genes. Loss of ZLL function in ago1 mutants led to increased AGO1 protein levels, whereas AGO1 mRNA levels were unchanged, implicating ZLL as a negative regulator of AGO1 at the protein level. Since ZLL, unlike AGO1, is not subjected to small RNA-mediated repression itself, this cross regulation has the potential to adjust RNA silencing activity independent of feedback dynamics. Although AGO1 is expressed in a broader pattern than ZLL, expression of AGO1 from the ZLL promoter restored transgene PTGS and most developmental defects of ago1, whereas ZLL rescued only a few AGO1 functions when expressed from the AGO1 promoter, suggesting that the specific functions of AGO1 and ZLL are mainly determined by their protein sequence. Protein domain swapping experiments revealed that the PAZ domain, which in AGO1 is involved in binding small RNAs, is interchangeable between both proteins, suggesting that this common small RNA-binding domain contributes to redundant functions. By contrast, the conserved MID and PIWI domains, which are involved in 5′-end small RNA selectivity and mRNA cleavage, and the non-conserved N-terminal domain, to which no function has been assigned, provide specificity to AGO1 and ZLL protein function

    Evaluating the use of multilocus variable number tandem repeat analysis of Shiga toxin-producing Escherichia coli O157 as a routine public health tool in England

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    Multilocus variable number tandem repeat analysis (MLVA) provides microbiological support for investigations of clusters of cases of infection with Shiga toxin-producing E. coli (STEC) O157. All confirmed STEC O157 isolated in England and submitted to the Gastrointestinal Bacteria Reference Unit (GBRU) during a six month period were typed using MLVA, with the aim of assessing the impact of this approach on epidemiological investigations. Of 539 cases investigated, 341 (76%) had unique (>2 single locus variants) MLVA profiles, 12% of profiles occurred more than once due to known household transmission and 12% of profiles occurred as part of 41 clusters, 21 of which were previously identified through routine public health investigation of cases. The remaining 20 clusters were not previously detected and STEC enhanced surveillance data for associated cases were retrospectively reviewed for epidemiological links including shared exposures, geography and/or time. Additional evidence of a link between cases was found in twelve clusters. Compared to phage typing, the number of sporadic cases was reduced from 69% to 41% and the diversity index for MLVA was 0.996 versus 0.782 for phage typing. Using MLVA generates more data on the spatial and temporal dispersion of cases, better defining the epidemiology of STEC infection than phage typing. The increased detection of clusters through MLVA typing highlights the challenges to health protection practices, providing a forerunner to the advent of whole genome sequencing as a diagnostic tool

    Sialoadhesin Expressed on IFN-Induced Monocytes Binds HIV-1 and Enhances Infectivity

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    Background: HIV-1 infection dysregulates the immune system and alters gene expression in circulating monocytes. Differential gene expression analysis of CD14 + monocytes from subjects infected with HIV-1 revealed increased expression of sialoadhesin (Sn, CD169, Siglec 1), a cell adhesion molecule first described in a subset of macrophages activated in chronic inflammatory diseases. Methodology/Principal Findings: We analyzed sialoadhesin expression on CD14 + monocytes by flow cytometry and found significantly higher expression in subjects with elevated viral loads compared to subjects with undetectable viral loads. In cultured CD14 + monocytes isolated from healthy individuals, sialoadhesin expression was induced by interferon-a and interferon-c but not tumor necrosis factor-a. Using a stringent binding assay, sialoadhesin-expressing monocytes adsorbed HIV-1 through interaction with the sialic acid residues on the viral envelope glycoprotein gp120. Furthermore, monocytes expressing sialoadhesin facilitated HIV-1 trans infection of permissive cells, which occurred in the absence of monocyte selfinfection. Conclusions/Significance: Increased sialoadhesin expression on CD14 + monocytes occurred in response to HIV-1 infection with maximum expression associated with high viral load. We show that interferons induce sialoadhesin in primary CD14 + monocytes, which is consistent with an antiviral response during viremia. Our findings suggest that circulating sialoadhesinexpressing monocytes are capable of binding HIV-1 and effectively delivering virus to target cells thereby enhancing th

    Does osteoporosis predispose falls? a study on obstacle avoidance and balance confidence

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    Contains fulltext : 96832.pdf (publisher's version ) (Open Access)BACKGROUND: Osteoporosis is associated with changes in balance and physical performance and has psychosocial consequences which increase the risk of falling. Most falls occur during walking; therefore an efficient obstacle avoidance performance might contribute to a reduction in fall risk. Since it was shown that persons with osteoporosis are unstable during obstacle crossing it was hypothesized that they more frequently hit obstacles, specifically under challenging conditions. METHODS: Obstacle avoidance performance was measured on a treadmill and compared between persons with osteoporosis (n = 85) and the comparison group (n = 99). The obstacle was released at different available response times (ART) to create different levels of difficulty by increasing time pressure. Furthermore, balance confidence, measured with the short ABC-questionnaire, was compared between the groups. RESULTS: No differences were found between the groups in success rates on the obstacle avoidance task (p = 0.173). Furthermore, the persons with osteoporosis had similar levels of balance confidence as the comparison group (p = 0.091). The level of balance confidence was not associated with the performance on the obstacle avoidance task (p = 0.145). CONCLUSION: Obstacle avoidance abilities were not impaired in persons with osteoporosis and they did not experience less balance confidence than the comparison group. These findings imply that persons with osteoporosis do not have an additional risk of falling because of poorer obstacle avoidance abilities
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