2,999 research outputs found

    Structures of minor ether lipids isolated from the aceticlastic methanogen, Methanothrix concilii GP6.

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    Structures were determined for two phospholipids and three glycolipids purified from chloroform-methanol extracts of Methanothrix concilii GP6. Together they accounted for 14% of the total lipid and were based on a C20,20-diether core structure consisting of either 2,3-di-O-phytanyl-sn-glycerol or its 3'-hydroxy analog, namely, 2-O-[3,7,11,15-tetramethylhexadecyl]-3-O-[3'- hydroxy-3',7',11',15'-tetramethylhexadecyl]-sn-glycerol. These two core lipids formed phosphodiester bonds to ethanolamine and glycosidic bonds to beta-D-galactopyranose. A third glycolipid consisted of the triglycosyl head group beta-D-galactopyranosyl-(1----6)-[beta-D-glucopyranosyl-(1----3)]-beta-D - galactopyranose in glycosidic linkage to the 3'-hydroxydiether core lipid

    Agreement and Discrepancy on Emotional and Behavioral Problems Between Caregivers and HIV-Infected Children and Adolescents From Uganda.

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    Background: HIV-infected children and adolescents (CA-HIV) face significant mental health challenges related to a broad range of biological and psychosocial factors. Data are scarce on the agreement and discrepancy between caregivers and CA-HIV regarding emotional and behavioral problems (EBPs) in CA-HIV. Objectives: We determined agreement between self- versus caregiver- reported EBPs and describe factors associated with informant discrepancy among caregiver-youth dyads who participated in the "Mental health among HIV-infected CHildren and Adolescents in KAmpala and Masaka, Uganda" (CHAKA) study. Methods: In a cross-sectional sample, caregiver-reported EBPs were assessed with the Child and Adolescent Symptom Inventory-5 (CASI-5), and self-reported problems were evaluated with the Youth Inventory-4 (YI-4) in 469 adolescents aged 12-17 years and the Child Inventory-4 (CI-4) in 493 children aged 8-11 years. Adolescents were questioned about experiences of HIV stigma. Caregiver psychological distress was assessed with the Self-Reporting Questionnaire (SRQ-20). Linear regression models were applied to identify variables associated with discrepancy scores. Results: Self-reported emotional problems (EPs) were present in 28.8% of adolescents and 36.9% of children, and 14.5% of adolescents self-reported behavioral problems (BPs). There was only a modest correlation (r ≤ 0.29) between caregiver- and CA-HIV-reported EBPs, with caregivers reporting more EPs whereas adolescents reported more BPs. Informant discrepancy between adolescents and caregivers for BPs was associated with adolescent age and caregiver's employment and HIV status. Among adolescents, EP discrepancy scores were associated with adolescent's WHO HIV clinical stage, caregiver level of education, and caregivers caring for other children. Among children, EP discrepancy scores were associated with child and caregiver age, caregiver level of education, and caregiver self-rated health status. HIV stigma and caregiver psychological distress were also associated with discrepancy, such that adolescents who experienced HIV stigma rated their EPs as more severe than their caregivers did and caregivers with increased psychological distress rated EBPs as more severe than CA-HIV self-rated. Conclusions: EBPs are frequently endorsed by CA-HIV, and agreement between informants is modest. Informant discrepancy is related to unique psychosocial and HIV-related factors. Multi-informant reports enhance the evaluation of CA-HIV and informant discrepancies can provide additional insights into the mental health of CA-HIV

    Mechanisms of Cognitive Impairment in Cerebral Small Vessel Disease: Multimodal MRI Results from the St George's Cognition and Neuroimaging in Stroke (SCANS) Study.

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    Cerebral small vessel disease (SVD) is a common cause of vascular cognitive impairment. A number of disease features can be assessed on MRI including lacunar infarcts, T2 lesion volume, brain atrophy, and cerebral microbleeds. In addition, diffusion tensor imaging (DTI) is sensitive to disruption of white matter ultrastructure, and recently it has been suggested that additional information on the pattern of damage may be obtained from axial diffusivity, a proposed marker of axonal damage, and radial diffusivity, an indicator of demyelination. We determined the contribution of these whole brain MRI markers to cognitive impairment in SVD. Consecutive patients with lacunar stroke and confluent leukoaraiosis were recruited into the ongoing SCANS study of cognitive impairment in SVD (n = 115), and underwent neuropsychological assessment and multimodal MRI. SVD subjects displayed poor performance on tests of executive function and processing speed. In the SVD group brain volume was lower, white matter hyperintensity volume higher and all diffusion characteristics differed significantly from control subjects (n = 50). On multi-predictor analysis independent predictors of executive function in SVD were lacunar infarct count and diffusivity of normal appearing white matter on DTI. Independent predictors of processing speed were lacunar infarct count and brain atrophy. Radial diffusivity was a stronger DTI predictor than axial diffusivity, suggesting ischaemic demyelination, seen neuropathologically in SVD, may be an important predictor of cognitive impairment in SVD. Our study provides information on the mechanism of cognitive impairment in SVD

    Genetic determination of the effect of post-translational modification on the innate immune response to the 19 kDa lipoprotein of Mycobacterium tuberculosis

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    <p>Abstract</p> <p>Background</p> <p>The 19 kDa lipoprotein of <it>Mycobacterium tuberculosis </it>(MTB) is an important target of the innate immune response. To investigate the effect of post-translation modification of this protein on innate recognition in the context of the whole bacillus, we derived a recombinant <it>M. tuberculosis </it>H37Rv that lacked the 19 kDa gene (Δ19) and complemented this strain by reintroduction of the 19 kDa gene into the chromosome as a single copy to produce Δ19::19. We also reintroduced the 19 kDa gene in two modified forms that lacked motifs for acylation (Δ19::19NA) and <it>O</it>-glycosylation (Δ19::19NOG).</p> <p>Results</p> <p>Both acylation and <it>O</it>-glycosylation were necessary for the protein to remain within the cell. IL-1 Beta secretion from human monocytes was significantly reduced by deletion of the 19 kDa gene (p < 0.02). Complementation by the wild type, but not the mutagenised gene reversed this phenotype. The effect of deletion and complementation on IL-12p40 and TNF secretion was less marked with no statistically significant differences between strains. Although deletion of the 19 kDa reduced apoptosis, an effect that could also only be reversed by complementation with the wild type gene, the results were variable between donors and did not achieve statistical significance.</p> <p>Conclusion</p> <p>These results confirm in the context of the whole bacillus an important role for post-translational modification of the 19 kDa on both the cellular location and immune response to this protein.</p

    Rhinovirus Outbreaks in Long-term Care Facilities, Ontario, Canada

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    Diagnostic difficulties may have led to underestimation of rhinovirus infections in long-term care facilities. Using surveillance data, we found that rhinovirus caused 59% (174/297) of respiratory outbreaks in these facilities during 6 months in 2009. Disease was sometimes severe. Molecular diagnostic testing can differentiate these outbreaks from other infections such as influenza

    Open source challenges for hospital information system (HIS) in developing countries: a pilot project in Mali

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    <p>Abstract</p> <p>Background</p> <p>We are currently witnessing a significant increase in use of Open Source tools in the field of health. Our study aims to research the potential of these software packages for developing countries. Our experiment was conducted at the Centre Hospitalier Mere Enfant in Mali.</p> <p>Methods</p> <p>After reviewing several Open Source tools in the field of hospital information systems, Mediboard software was chosen for our study. To ensure the completeness of Mediboard in relation to the functionality required for a hospital information system, its features were compared to those of a well-defined comprehensive record management tool set up at the University Hospital "La Timone" of Marseilles in France. It was then installed on two Linux servers: a first server for testing and validation of different modules, and a second one for the deployed full implementation. After several months of use, we have evaluated the usability aspects of the system including feedback from end-users through a questionnaire.</p> <p>Results</p> <p>Initial results showed the potential of Open Source in the field of health IT for developing countries like Mali.</p> <p>Five main modules have been fully implemented: patient administrative and medical records management of hospital activities, tracking of practitioners' activities, infrastructure management and the billing system. This last component of the system has been fully developed by the local Mali team.</p> <p>The evaluation showed that the system is broadly accepted by all the users who participated in the study. 77% of the participants found the system useful; 85% found it easy; 100% of them believe the system increases the reliability of data. The same proportion encourages the continuation of the experiment and its expansion throughout the hospital.</p> <p>Conclusions</p> <p>In light of the results, we can conclude that the objective of our study was reached. However, it is important to take into account the recommendations and the challenges discussed here to avoid several potential pitfalls specific to the context of Africa.</p> <p>Our future work will target the full integration of the billing module in Mediboard and an expanded implementation throughout the hospital.</p

    Long Term Spectral and Timing Behavior of the Black Hole Candidate XTE J1908+094

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    We present the long term X-ray light curves, detailed spectral and timing analyses of XTE J1908+094 using the Rossi X-ray Timing Explorer Proportional Counter Array observations covering two outbursts in 2002 and early 2003. At the onset of the first outburst, the source was found in a spectrally low/hard state lasting for ~40 days, followed by a three day long transition to the high/soft state. The source flux (in 2-10 keV) reached \sim100 mCrab on 2002 April 6, then decayed rapidly. In power spectra, we detect strong band-limited noise and varying low-frequency quasi periodic oscillations that evolved from ~0.5 Hz to ~5 Hz during the initial low/hard state of the source. We find that the second outburst closely resembled the spectral evolution of the first. The X-ray transient's overall outburst characteristics lead us to classify XTE J1908+094 as a black-hole candidate. Here we also derive precise X-ray position of the source using Chandra observations which were performed during the decay phase of the first outburst and following the second outburst.Comment: 26 pages, 17 figures, ApJ, in pres
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