162 research outputs found

    Plasma vitamin A and zinc levels in HIV-infected adults in Cape Town, South Africa

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    A cross-sectional study of 132 adults attending an HIV clinic in Cape Town, South Africa, was conducted to determine predictors of low plasma vitamin A and Zn levels. No patients were on antiretroviral therapy. The possible confounding effect of the acute-phase response was controlled by including C-reactive protein levels in multivariate analysis and by excluding active opportunistic infections. Retinol levels were low (< 1.05 ÎĽmol/l) in 39% of patients with early disease (WHO clinical stages I and II) compared with 48 and 79 % of patients with WHO stage III and IV respectively (P<0.01). Plasma Zn levels were low (< 10.7 ÎĽmol/l) in 20% of patients with early disease v. 36 and 45 % with stage III and IV disease respectively (P< 0.05). C-reactive protein levels were normal in 63 % of subjects. Weak, positive associations were found between CD4+lymphocyte count and plasma levels of retinol (r 0.27; 95 % CI 0.1, 0.43) and Zn (r 0.31; 95% CI 0.25, 0.46). Multivariate analysis showed the following independent predictors of low retinol levels: WHO stage IV (odds ratio 3.4; 95 % CI 2.1, 5.7) and body weight (odds ratio per 5 kg decrease 1.15; 95% CI, 1-08, 1.25), while only body weight was significantly associated with low Zn levels (OR per 5 kg decrease 1.19; 95% CI 1.09, 1.30). CD4+lymphocyte count <200/ÎĽl was not significantly associated with either low retinol or Zn levels. In resource-poor settings, simple clinical features (advanced disease and/or weight loss) are associated with lowered blood concentrations of vitamin A and/or Zn. The clinical significance of low plasma retinol and/or Zn levels is unclear and more research is required to establish the role of multiple micronutrient intervention strategies in HIV disease

    Soil zinc content, groundwater usage, and prostate cancer incidence in South Carolina

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    Background Prostate cancer (PrCA) incidence in South Carolina (SC) exceeds the national average, particularly among African Americans (AAs). Though data are limited, low environmental zinc exposures and down-regulation of prostatic zinc transporter proteins among AAs may explain, in part, the racial PrCA disparity. Methods Age-adjusted PrCA rates were calculated by census tract. Demographic data were obtained from the 1990 census. Hazardous waste site locations and soil zinc concentrations were obtained from existing federal and state databases. A geographic information system and Poisson regression were used to test the hypothesis that census tracts with reduced soil zinc concentrations, elevated groundwater use, or more agricultural or hazardous waste sites had elevated PrCA risks. Results Census tracts with high groundwater use and low zinc concentrations had higher PrCA rate ratios (RR: 1.270; 95% confidence interval: 1.079, 1.505). This effect was not more apparent in areas populated primarily by AAs. Conclusion Increased PrCA rates were associated with reduced soil zinc concentrations and elevated groundwater use, although this observation is not likely to contribute to SC’s racial PrCA disparity. Statewide mapping and statistical modeling of relationships between environmental factors, demographics, and cancer incidence can be used to screen hypotheses focusing on novel PrCA risk factors

    Coherent c-axis transport in the underdoped cuprate superconductor YBCO

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    The electrical resistivity rho_c of the underdoped cuprate superconductor YBCO was measured perpendicular to the CuO_2 planes on ultra-high quality single crystals in magnetic fields large enough to suppress superconductivity. The incoherent insulating-like behavior of rho_c at high temperature, characteristic of all underdoped cuprates, is found to cross over to a coherent regime of metallic behavior at low temperature. This crossover coincides with the emergence of the small electron pocket detected in the Fermi surface of YBCO via quantum oscillations, the Hall and Seebeck coefficients and with the detection of a unidirectional modulation of the charge density as seen by high-field NMR measurements. The low coherence temperature is quantitatively consistent with the small hopping integral t_perp inferred from the splitting of the quantum oscillation frequencies. We conclude that the Fermi-surface reconstruction in YBCO at dopings from p = 0.08 to at least p = 0.15, attributed to stripe order, produces a metallic state with 3D coherence deep in the underdoped regime.Comment: 7 pages, 7 figure

    Circulating Serum Exosomal miRNAs As Potential Biomarkers for Esophageal Adenocarcinoma

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    Author version made available in accordance with publisher policy.Abstract Background The poor prognosis and rising incidence of esophageal adenocarcinoma highlight the need for improved detection methods. The potential for circulating microRNAs (miRNAs) as biomarkers in other cancers has been shown, but circulating miRNAs have not been well characterized in esophageal adenocarcinoma. We investigated whether circulating exosomal miRNAs have potential to discriminate individuals with esophageal adenocarcinoma from healthy controls and non-dysplastic Barrett’s esophagus. Methods Seven hundred fifty-eight miRNAs were profiled in serum circulating exosomes from a cohort of 19 healthy controls, 10 individuals with Barrett’s esophagus, and 18 individuals with locally advanced esophageal adenocarcinoma. MiRNA expression was assessed using all possible permutations of miRNA ratios per individual. Four hundred eight miRNA ratios were differentially expressed in individuals with cancer compared to controls and Barrett’s esophagus (Mann-Whitney U test, P<0.05). The 179/408 ratios discriminated esophageal adenocarcinoma from healthy controls and Barrett’s esophagus (linear regression, P0.7, P<0.05). A multi-biomarker panel (RNU6-1/miR- 16-5p, miR-25-3p/miR-320a, let-7e-5p/miR-15b-5p, miR- 30a-5p/miR-324-5p, miR-17-5p/miR-194-5p) demonstrated enhanced specificity and sensitivity (area under ROC=0.99, 95 % CI 0.96–1.0) over single miRNA ratios to distinguish esophageal adenocarcinoma from controls and Barrett’s esophagus. Conclusions This study highlights the potential for serum exosomal miRNAs as biomarkers for the detection of esophageal adenocarcinoma

    Phonon dispersion in 1-layer cuprate HgBa2CuO4+d

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    We investigate the low energy acoustical and optical modes in HgBa2CuO4+δ\mathrm{HgBa_2CuO_{4+\delta}} using inelastic x-ray scattering (IXS). The experimental phonon dispersion and the dynamical structure factor are compared with an atomic shell model, and the set of the atomic potentials obtained are discussed. Our results are also compared with those obtained by Raman spectroscopy and with density-of-state data measured by inelastic neutron scattering

    Global Spatial Risk Assessment of Sharks Under the Footprint of Fisheries

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    Effective ocean management and conservation of highly migratory species depends on resolving overlap between animal movements and distributions and fishing effort. Yet, this information is lacking at a global scale. Here we show, using a big-data approach combining satellite-tracked movements of pelagic sharks and global fishing fleets, that 24% of the mean monthly space used by sharks falls under the footprint of pelagic longline fisheries. Space use hotspots of commercially valuable sharks and of internationally protected species had the highest overlap with longlines (up to 76% and 64%, respectively) and were also associated with significant increases in fishing effort. We conclude that pelagic sharks have limited spatial refuge from current levels of high-seas fishing effort. Results demonstrate an urgent need for conservation and management measures at high-seas shark hotspots and highlight the potential of simultaneous satellite surveillance of megafauna and fishers as a tool for near-real time, dynamic management
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