1,499 research outputs found

    Expression in Escherichia coli of a cloned DNA sequence encoding the pre-S2 region of hepatitis B virus

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    A DNA sequence encoding the entire pre-S2 region (amino acids 120-174; serotype ayw) of human hepatitis B virus envelope protein has been inserted into the lacZ gene of the plasmid pSKS105 yielding a recombinant, pWS3. Lac+ colonies of the Escherichia coli M182 (lacIOPZYA), isolated after transformation with pWS3, produced a pre-S2 peptide-ß-galactosidase fusion protein. This fusion protein, which comprised as much as 3% of the total bacterial protein, was purified to >90% homogeneity by affinity chromatography on p-aminophenyl-ß-D-thiogalactoside-Sepharose. It is immunoprecipitable with rabbit antibodies to a synthetic peptide corresponding to amino acids 120-145 of the pre-S2 region of serotype adw [pre-S(120-145)] or with antibodies to hepatitis B virus. pre-S(120-145) completely blocked the binding of either antibody to the pre-S2 peptide-ß-galactosidase fusion protein. These results indicate that there are antigenic determinants on the fusion protein that are closely related to, if not identical to, determinants on synthetic pre-S(120-145) and on pre-S2 sequences of native hepatitis B virus particles. Thus, bacteria transformed with pWS3 can provide an abundant source of pre-S2-ß-galactosidase fusion protein, which may prove useful either as a diagnostic reagent possessing marker enzyme activity suitable for ELISA tests or as an immunogen with potential to contribute to active prophylaxis of hepatitis B

    Adequacy of Cancer Screening in Adult Women with Congenital Heart Disease

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    Adults with congenital heart disease (ACHD) face noncardiac healthcare challenges as the population ages. We assessed whether women with ACHD have comparable cancer screening rates to non-ACHD women in a cardiac practice and to the general population. We performed a retrospective review of 175 adult women seen in a cardiac care center in 2009–2011. Data on Pap tests, mammography, and colonoscopies, were collected through electronic medical records and primary care provider records. Adequate documentation was available for 100 individuals with ACHD and 40 comparator cardiac patients. The adequacy of screening was determined using guidelines set forth by the American Cancer Society in 2010. Compared with the national average, ACHD patients had significantly lower rates of Pap tests (60% versus 83%, P < 0.001) and mammography (48% versus 72%, P < 0.001). Compared with non-ACHD women in the same practice, ACHD patients had consistently lower rates of mammography (48% versus 81%, P = 0.02) and colonoscopies (54% versus 82%, P = 0.23). As the population of ACHD individuals ages, attention to cancer screening becomes increasingly important but may be overlooked in this population. Primary care physicians and cardiologists should collaborate to ensure appropriate cancer screening for this growing population

    Sepsis in cirrhosis: report on the 7th meeting of the International Ascites Club.

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    Sepsis is a systemic inflammatory response to the presence of infection, mediated via the production of many cytokines, including tumour necrosis factor ¿ (TNF-¿), interleukin (IL)-6, and IL-1, which cause changes in the circulation and in the coagulation cascade. There is stagnation of blood flow and poor oxygenation, subclinical coagulopathy with elevated D-dimers, and increased production of superoxide from nitric oxide synthase. All of these changes favour endothelial apoptosis and necrosis as well as increased oxidant stress. Reduced levels of activated protein C, which is normally anti-inflammatory and antiapoptotic, can lead to further tissue injury. Cirrhotic patients are particularly susceptible to bacterial infections because of increased bacterial translocation, possibly related to liver dysfunction and reduced reticuloendothelial function. Sepsis ensues when there is overactivation of pathways involved in the development of the sepsis syndrome, associated with complications such as renal failure, encephalopathy, gastrointestinal bleed, and shock with decreased survival. Thus the treating physician needs to be vigilant in diagnosing and treating bacterial infections in cirrhosis early, in order to prevent the development and downward spiral of the sepsis syndrome. Recent advances in management strategies of infections in cirrhosis have helped to improve the prognosis of these patients. These include the use of prophylactic antibiotics in patients with gastrointestinal bleed to prevent infection and the use of albumin in patients with spontaneous bacterial peritonitis to reduce the incidence of renal impairment. The use of antibiotics has to be judicious, as their indiscriminate use can lead to antibiotic resistance with potentially disastrous consequences

    The Limits and Contradictions of Systemic Reform: The Philadelphia Story

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    In Philadelphia, the Annenberg Challenge was known as Children Achieving and was a districtwide systemic reform initiative designed and led by a small core group of District officials and external partners. This report examines the Children Achieving Challenge and the strategies the designers employed to improve teaching and learning in the public schools. Among the conditions associated with the Annenberg Challenge were requirements that two matching dollars be raised for each one received from the Annenberg Foundation and that an independent management structure be created to provide program, fiscal, and evaluation oversight of the grant. In Philadelphia, a business organization, Greater Philadelphia First, assumed these responsibilities, and with them, the challenge of working with the School District to build and sustain civic support for the improvement of the public schools

    (Un)Structuring for the Next Generation: New Possibilities for Library Data with NoSQL

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    For many years, libraries have relied upon relational databases (RDBMS) to store, manipulate, and query various types of data, and this database model works extremely well when data are highly structured. As the data become more complex, however, the relational database model strains under the burden of maintaining complex joins, which can decrease a database\u27s performance and limit its functionality. Furthermore, data are not always best represented in the RDBMS\u27s flat, tabular format. Library data often require flexibility and extensibility to accommodate the increasing volume and variety of library resources and metadata. To address these issues, transforming the underlying structure of data will be as important as transforming the data itself. NoSQL offers an alternative model for efficiently managing dynamic data

    Low plasma citrulline levels are associated with acute respiratory distress syndrome in patients with severe sepsis

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    INTRODUCTION: The role of nitric oxide synthase (NOS) in the pathophysiology of acute respiratory distress syndrome (ARDS) is not well understood. Inducible NOS is upregulated during physiologic stress; however, if NOS substrate is insufficient then NOS can uncouple and switch from NO generation to production of damaging peroxynitrites. We hypothesized that NOS substrate levels are low in patients with severe sepsis and that low levels of the NOS substrate citrulline would be associated with end organ damage including ARDS in severe sepsis. METHODS: Plasma citrulline, arginine and ornithine levels and nitrate/nitrite were measured at baseline in 135 patients with severe sepsis. ARDS was diagnosed by consensus definitions. RESULTS: Plasma citrulline levels were below normal in all patients (median 9.2 uM, IQR 5.2 - 14.4) and were significantly lower in ARDS compared to the no ARDS group (6.0 (3.3 - 10.4) vs. 10.1 (6.2 - 16.6), P = 0.002). The rate of ARDS was 50% in the lowest citrulline quartile compared to 15% in the highest citrulline quartile (P = 0.002). In multivariable analyses, citrulline levels were associated with ARDS even after adjustment for covariates including severity of illness. CONCLUSIONS: In severe sepsis, levels of the NOS substrate citrulline are low and are associated with ARDS. Low NOS substrate levels have been shown in other disease states to lead to NOS uncoupling and oxidative injury suggesting a potential mechanism for the association between low citrulline and ARDS. Further studies are needed to determine whether citrulline supplementation could prevent the development of ARDS in patients with severe sepsis and to determine its role in NOS coupling and function

    Diversification and Adaptive Capacity across Scales in an Emerging Post-Frontier Landscape of the Usumacinta Valley, Chiapas, Mexico

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    This study investigates impacts and implications of recent landscape change in rural Mexico, through a case study in the Usumacinta Valley of eastern Chiapas. It addresses types of livelihood diversification strategies associated with changing land cover from 1984–2013, and the processes and roles that vary by actors and their scales of influence. After widespread forest loss and the expansion of extensive cattle ranching during the twentieth century, the region has exhibited several new economic and livelihood strategies in recent decades. Results from a combination of satellite imagery analysis and individual interviews from a wide range of land use decision makers demonstrate the dynamism of this landscape. The introduction of new crops, including teak, rubber and oil palm, as well as off-farm work, continue to shape the social and physical landscape and differentially impact the adaptive capacities of residents. Results indicate that small landholders often need to incorporate more crops into their agricultural portfolio and increase off-farm activities, leading to an atomization of livelihood strategies. By contrast, large landholders are able to pursue more specialized and lucrative agricultural opportunities

    Distinguishing Land Change from Natural Variability and Uncertainty in Central Mexico with MODIS EVI, TRMM Precipitation, and MODIS LST Data

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    Precipitation and temperature enact variable influences on vegetation, impacting the type and condition of land cover, as well as the assessment of change over broad landscapes. Separating the influence of vegetative variability independent and discrete land cover change remains a major challenge to landscape change assessments. The heterogeneous Lerma-Chapala-Santiago watershed of central Mexico exemplifies both natural and anthropogenic forces enacting variability and change on the landscape. This study employed a time series of Enhanced Vegetation Index (EVI) composites from the Moderate Resolution Imaging Spectoradiometer (MODIS) for 2001–2007 and per-pixel multiple linear regressions in order to model changes in EVI as a function of precipitation, temperature, and elevation. Over the seven-year period, 59.1% of the variability in EVI was explained by variability in the independent variables, with highest model performance among changing and heterogeneous land cover types, while intact forest cover demonstrated the greatest resistance to changes in temperature and precipitation. Model results were compared to an independent change uncertainty assessment, and selected regional samples of change confusion and natural variability give insight to common problems afflicting land change analyses
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