1,740 research outputs found

    Which comorbid conditions should we be analyzing as risk factors for healthcare-associated infections?

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    OBJECTIVETo determine which comorbid conditions are considered causally related to central-line associated bloodstream infection (CLABSI) and surgical-site infection (SSI) based on expert consensus.DESIGNUsing the Delphi method, we administered an iterative, 2-round survey to 9 infectious disease and infection control experts from the United States.METHODSBased on our selection of components from the Charlson and Elixhauser comorbidity indices, 35 different comorbid conditions were rated from 1 (not at all related) to 5 (strongly related) by each expert separately for CLABSI and SSI, based on perceived relatedness to the outcome. To assign expert consensus on causal relatedness for each comorbid condition, all 3 of the following criteria had to be met at the end of the second round: (1) a majority (&gt;50%) of experts rating the condition at 3 (somewhat related) or higher, (2) interquartile range (IQR)≀1, and (3) standard deviation (SD)≀1.RESULTSFrom round 1 to round 2, the IQR and SD, respectively, decreased for ratings of 21 of 35 (60%) and 33 of 35 (94%) comorbid conditions for CLABSI, and for 17 of 35 (49%) and 32 of 35 (91%) comorbid conditions for SSI, suggesting improvement in consensus among this group of experts. At the end of round 2, 13 of 35 (37%) and 17 of 35 (49%) comorbid conditions were perceived as causally related to CLABSI and SSI, respectively.CONCLUSIONSOur results have produced a list of comorbid conditions that should be analyzed as risk factors for and further explored for risk adjustment of CLABSI and SSI.Infect Control Hosp Epidemiol 2017;38:449–454</jats:sec

    Scanning Electron Microscopy Studies of Staphylococcal Adherence to Heart Valve Endothelial Cells in Organ Culture: An In Vitro Model of Acute Endocarditis

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    Organ cultures of human heart valves were used as a model to study the initial pathobiology of acute infective bacterial endocarditis. We used Staphylococcus aureus isolated from a case of infective endocarditis to infect the in vitro culture of the heart valves. Using scanning electron microscopy, we assessed the initial damage, attachment to and invasion of the endothelial cell layer by staphylococci. Our results indicate there is initial damage to the endothelium prior to observation of staphylococci attaching to the endothelial cell. By 12 h post infection, there is significant attachment and damage. At 24 h after infection, destruction of the heart valve endothelium is complete. The attachment and destruction arc progressive events and can be correlated quantitatively with bacterial numbers from the culture medium and those attached to the valves. This is correlated with increasing adherence ratios of the attaching staphylococci

    Annual Variation in Habitat Use by White-footed Mice, Peromyscus leucopus: The Effects of Forest Patch Size, Edge and Surrounding Vegetation Type

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    White-footed Mice (Peromyscus leucopus) were trapped for two years in the exterior matrix, edge, and interior forest habitat sections of six forests patches in a fragmented agricultural landscape. We used data on the capture locations of P. leucopus individuals from the two years, which differed in rainfall (i.e., summer of 2000 with 50% more rain than summer of 1999), to assess how patch size, edge habitat, and surrounding habitat type influence habitat use and movements in populations of this forest habitat generalist. We found that the proportion of individuals subsequently captured in the forest edge from the exterior was 16 times greater in the wet year than in the dry year and approximately twice as many P. leucopus were not subsequently recaptured from the exterior matrix in the dry year compared to the wet year. For each year, captures between habitats did not differ in relation to patch size, edge forest habitat, or exterior matrix type. These results illustrate the generalist habitat preferences of P. leucopus, but emphasize annual variation in their behavior and distribution

    The prevalence of hepatitis C virus among people of South Asian origin in Glasgow: results from a community based survey and laboratory surveillance

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    Background South Asians often present late with HCV or HBV related liver disease which could have been avoided with early diagnosis and subsequent treatment; however the prevalence of HCV/HBV among South Asians in Glasgow is not known. Accordingly, to inform the need for case finding among this group we aimed to examine the prevalence of Hepatitis C virus (HCV) among South Asians living in Glasgow. Methods A community-based survey recruited individuals at six mosques and four community centres serving the South Asian community during 2009-2010; participants had predominantly never been HCV tested. Laboratory surveillance data involving all individuals tested for HCV during 1993-2009 were examined and South Asians were identified using Nam Pehchan software. Results In the community-based survey, 2.6% of 1288 participants tested HCV-antibody positive; the prevalence ranged from 0.6% among those born in the UK to 3.1% among those born in Pakistan. The odds of testing HCV-antibody positive were significantly raised among those who had surgery in South Asia (aOR: 5.0, 95% CI: 2.0-12.3) and had either medical/dental treatment or an injection in South Asia (aOR: 2.2, 95% CI: 1.0-5.0). Of 6404 South Asians identified from laboratory surveillance data, 9.3% tested HCV positive. An estimated 38% (330/870) of HCV-infected South Asians living in Glasgow remain undiagnosed. Conclusions South Asians living in Glasgow, particularly those born outside the UK are at greater risk of HCV infection than the general population. Efforts to increase awareness and testing in this population are warranted.</p

    Increased Expression of Cytotoxic T-Lymphocyte-Associated Protein 4 by T Cells, Induced by B7 in Sera, Reduces Adaptive Immunity in Patients With Acute Liver Failure.

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    BACKGROUND & AIMS: Patients with acute liver failure (ALF) have defects in innate immune responses to microbes (immune paresis) and are susceptible to sepsis. Cytotoxic T-lymphocyte-associated protein 4 (CTLA4), which interacts with the membrane receptor B7 (also called CD80 and CD86), is a negative regulator of T-cell activation. We collected T cells from patients with ALF and investigated whether inhibitory signals down-regulate adaptive immune responses in patients with ALF. METHODS: We collected peripheral blood mononuclear cells from patients with ALF and controls from September 2013 through September 2015 (45 patients with ALF, 20 patients with acute-on-chronic liver failure, 15 patients with cirrhosis with no evidence of acute decompensation, 20 patients with septic shock but no cirrhosis or liver disease, and 20 healthy individuals). Circulating CD4+ T cells were isolated and analyzed by flow cytometry. CD4+ T cells were incubated with antigen, or agonist to CD3 and dendritic cells, with or without antibody against CTLA4; T-cell proliferation and protein expression were quantified. We measured levels of soluble B7 molecules in supernatants of isolated primary hepatocytes, hepatic sinusoidal endothelial cells, and biliary epithelial cells from healthy or diseased liver tissues. We also measured levels of soluble B7 serum samples from patients and controls, and mice with acetaminophen-induced liver injury using enzyme-linked immunosorbent assays. RESULTS: Peripheral blood samples from patients with ALF had a higher proportion of CD4+ CTLA4+ T cells than controls; patients with infections had the highest proportions. CD4+ T cells from patients with ALF had a reduced proliferative response to antigen or CD3 stimulation compared to cells from controls; incubation of CD4+ T cells from patients with ALF with an antibody against CTLA4 increased their proliferative response to antigen and to CD3 stimulation, to the same levels as cells from controls. CD4+ T cells from controls up-regulated expression of CTLA4 after 24-48 hours culture with sera from patients with ALF; these sera were found to have increased concentrations of soluble B7 compared to sera from controls. Necrotic human primary hepatocytes exposed to acetaminophen, but not hepatic sinusoidal endothelial cells and biliary epithelial cells from patients with ALF, secreted high levels of soluble B7. Sera from mice with acetaminophen-induced liver injury contained high levels of soluble B7 compared to sera from mice without liver injury. Plasma exchange reduced circulating levels of soluble B7 in patients with ALF and expression of CTLA4 on T cells. CONCLUSIONS: Peripheral CD4+ T cells from patients with ALF have increased expression of CTLA4 compared to individuals without ALF; these cells have a reduced response to antigen and CD3 stimulation. We found sera of patients with ALF and from mice with liver injury to have high concentrations of soluble B7, which up-regulates CTLA4 expression by T cells and reduces their response to antigen. Plasma exchange reduces levels of B7 in sera from patients with ALF and might be used to restore antimicrobial responses to patients

    Prospects of Transition Interface Sampling simulations for the theoretical study of zeolite synthesis

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    The transition interface sampling (TIS) technique allows to overcome large free energy barriers within reasonable simulation time, which is impossible for straightforward molecular dynamics. Still, the method does not impose an artificial driving force, but it surmounts the timescale problem by an importance sampling of true dynamical pathways. Recently, it was shown that the efficiency of TIS to calculate reaction rates is less sensitive to the choice of reaction coordinate than those of the standard free energy based techniques. This could be an important advantage in complex systems for which a good reaction coordinate is usually very difficult to find. We explain the principles of this method and discuss some of the promising applications related to zeolite formation.Comment: 9 pages, accepted for publication in Phys. Chem. Chem. Phys. for the special issue of the CECAM workshop: Computational aspects of building blocks, nucleation, and synthesis of porous materials Aug. 29 2006 to Aug. 31 200

    Psychometric properties of the Ndetei–Othieno–Kathuku (NOK) Scale: A mental health assessment tool for an African setting

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    Background: Research suggests that psychiatric conditions in children and adolescents are highly debilitating, with sparse resources for assessment and treatment in low- and middle-income countries (LMICs). Objectives: The primary aim of this study was to evaluate the reliability, validity, and latent factor structure of an ethnographically-grounded assessment instrument for detecting common mental health complaints among rural Kenyan children and adolescents. Methods: The Ndetei–Othieno–Kathuku Scale (NOK) was delivered to 2 282 children aged 10 to 18 years old. Exploratory factor analysis identified four latent factors. This structure was confirmed in subsequent confirmatory factor analyses. External validity was explored by investigating associations among NOK factors and Youth Self-Report DSM-oriented scales. Results: Findings suggest the NOK possesses good internal reliability and a four-factor latent structure corresponding to depression, anxiety, somatic complaints, and a mixed factor. Significant associations ranging from small to medium effect sizes were noted between NOK factors and YSR DSM-oriented scales. Conclusions: Exploratory findings suggest that the NOK possesses adequate psychometric properties among this population. This ethnographically-grounded instrument may be uniquely suited to screening for mental health complaints among Kenyan children and adolescents

    Kinomic exploration of temozolomide and radiation resistance in Glioblastoma multiforme xenolines

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    Glioblastoma multiforme (GBM) represents the most common and deadly primary brain malignancy, particularly due to temozolomide (TMZ) and radiation (RT) resistance. To better understand resistance mechanisms, we examined global kinase activity (kinomic profiling) in both treatment sensitive and resistant human GBM patient-derived xenografts (PDX or “xenolines”)
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