4,640 research outputs found

    Perfluorooctanoic acid exposure triggers oxidative stress in the mouse pancreas

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    • PFOA triggers focal ductal hyperplasia following 7 day exposure. • PFOA exposure increases 8-iso-PGF2α levels in the pancreas. • Antioxidant gene expression is upregulated in the pancreas following PFOA exposure. , Perfluorooctanoic acid (PFOA) is used in the manufacture of many industrial and commercial products. PFOA does not readily decompose in the environment, and is biologically persistent. Human epidemiologic and animal studies suggest that PFOA exposure elicits adverse effects on the pancreas. While multiple animal studies have examined PFOA-mediated toxicity in the liver, little is known about the potential adverse effects of PFOA on the pancreas. To address this, we treated C57Bl/6 mice with vehicle, or PFOA at doses of 0.5, 2.5 or 5.0 mg/kg BW/day for 7 days. Significant accumulation of PFOA was found in the serum, liver and pancreas of PFOA-treated animals. Histopathologic examination of the pancreas revealed focal ductal hyperplasia in mice treated with 2.5 and 5.0 mg/kg BW/day PFOA, while inflammation was observed only in the high dose group. Elevated serum levels of amylase and lipase were observed in the 2.5 mg/kg BW/day PFOA treatment group. In addition, PFOA exposure resulted in a dose-dependent increase in the level of the lipid peroxidation product 8-iso-PGF2α and induction of the antioxidant response genes Sod1, Sod2, Gpx2 and Nqo1. Our findings provide additional evidence that the pancreas is a target organ for PFOA-mediated toxicity and suggest that oxidative stress may be a mechanism through which PFOA induces histopathological changes in the pancreas

    I Keep my Problems to Myself: Negative Social Network Orientation, Social Resources, and Health-Related Quality of Life in Cancer Survivors

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    Cancer survivors treated with hematopoietic stem cell transplant rely on their social network for successful recovery. However, some survivors have negative attitudes about using social resources (negative social network orientation) that are critical for their recovery

    Graduating with a Science Major: The Roles of First-Year Science Interests and Educational Aspirations

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    The purpose of this longitudinal study was to determine whether the degree of science interests and educational aspirations in students’ first year of university would significantly differentiate those students who graduated with a science major from those students who did not graduate with a science major. Moreover, the authors expected that educational aspirations would moderate the relation between science interests and graduating with/without a science major. First-year college students in introductory science courses were surveyed in their first semester and then again upon graduation. These 166 students’ science interests and educational aspirations were assessed at Time 1; their educational major was assessed upon graduation. The findings supported both hypotheses. Science interests and educational aspirations significantly differentiated whether or not students graduated with science majors. Moreover, the interaction of science interests and educational aspirations also significantly differentiated whether or not students graduated with a science major. In short, students who graduated with science majors, compared to their counterparts who graduated with nonscience majors, had significantly higher interests only when they also had higher educational aspirations

    An Exploratory Study of Lecturers' Views of Out-of-class Academic Collaboration Among Students

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    This article reports an exploratory study of lecturers' perceptions of out-of-class academic collaboration (OCAC) among students at a large Singapore university. Two types of OCAC were investigated: collaboration initiated by students, e.g., groups decide on their own to meet to prepare for exams, and collaboration required by teachers, e.g., teachers assign students to do projects in groups. Data were collected via one-on-one interviews with 18 faculty members from four faculties at the university. Findings suggest that OCAC, especially of a teacher-required kind, is fairly common at the university. Faculty members' views on factors affecting the success of OCAC are discussed for the light they might shed on practices to enhance the effectiveness of OCAC

    Meningococcal Disease in Patients With Human Immunodeficiency Virus Infection: A Review of Cases Reported Through Active Surveillance in the United States, 2000-2008.

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    BackgroundAlthough human immunodeficiency virus (HIV) infection is an established risk factor for several bacterial infections, the association between HIV infection and meningococcal disease remains unclear.MethodsExpanded chart reviews were completed on persons with meningococcal disease and HIV infection reported from 2000 through 2008 from 9 US sites participating in an active population-based surveillance system for meningococcal disease. The incidence of meningococcal disease among patients meeting Centers for Disease Control and Prevention acquired immune deficiency syndrome (AIDS) surveillance criteria was estimated using data from the National HIV Surveillance System for the participating sites.ResultsThirty-three cases of meningococcal disease in individuals with HIV infection were reported from participating sites, representing 2.0% of all reported meningococcal disease cases. Most (75.8%) persons with HIV infection were adult males aged 25 to 64 years old. Among all meningococcal disease cases aged 25 to 64 years old, case fatality ratios were similar among HIV-infected and HIV-uninfected persons (13.3% vs 10.6%; P = .6). The cumulative, mean incidence of meningococcal disease among patients aged 25 to 64 years old with HIV infection ever classified as AIDS was 3.5 cases per 100000 person years (95% confidence interval [CI], 2.1-5.6), compared with 0.3 cases per 100000 person years (95% CI, 0.3-0.3) for persons of the same age group not reported to have AIDS (relative risk = 12.9; 95% CI, 7.9-20.9).ConclusionsIndividuals with HIV infection meeting the AIDS surveillance case definition have a higher incidence of meningococcal disease compared with the general adult population

    A common and unstable copy number variant is associated with differences in Glo1 expression and anxiety-like behavior

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    Glyoxalase 1 (Glo1) has been implicated in anxiety-like behavior in mice and in multiple psychiatric diseases in humans. We used mouse Affymetrix exon arrays to detect copy number variants (CNV) among inbred mouse strains and thereby identified a approximately 475 kb tandem duplication on chromosome 17 that includes Glo1 (30,174,390-30,651,226 Mb; mouse genome build 36). We developed a PCR-based strategy and used it to detect this duplication in 23 of 71 inbred strains tested, and in various outbred and wild-caught mice. Presence of the duplication is associated with a cis-acting expression QTL for Glo1 (LOD>30) in BXD recombinant inbred strains. However, evidence for an eQTL for Glo1 was not obtained when we analyzed single SNPs or 3-SNP haplotypes in a panel of 27 inbred strains. We conclude that association analysis in the inbred strain panel failed to detect an eQTL because the duplication was present on multiple highly divergent haplotypes. Furthermore, we suggest that non-allelic homologous recombination has led to multiple reversions to the non-duplicated state among inbred strains. We show associations between multiple duplication-containing haplotypes, Glo1 expression and anxiety-like behavior in both inbred strain panels and outbred CD-1 mice. Our findings provide a molecular basis for differential expression of Glo1 and further implicate Glo1 in anxiety-like behavior. More broadly, these results identify problems with commonly employed tests for association in inbred strains when CNVs are present. Finally, these data provide an example of biologically significant phenotypic variability in model organisms that can be attributed to CNVs.These studies were funded by MH070933, MH79103 and MH020065

    Differential control of Zap1-regulated genes in response to zinc deficiency in Saccharomyces cerevisiae

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    <p>Abstract</p> <p>Background</p> <p>The Zap1 transcription factor is a central player in the response of yeast to changes in zinc status. We previously used transcriptome profiling with DNA microarrays to identify 46 potential Zap1 target genes in the yeast genome. In this new study, we used complementary methods to identify additional Zap1 target genes.</p> <p>Results</p> <p>With alternative growth conditions for the microarray experiments and a more sensitive motif identification algorithm, we identified 31 new potential targets of Zap1 activation. Moreover, an analysis of the response of Zap1 target genes to a range of zinc concentrations and to zinc withdrawal over time demonstrated that these genes respond differently to zinc deficiency. Some genes are induced under mild zinc deficiency and act as a first line of defense against this stress. First-line defense genes serve to maintain zinc homeostasis by increasing zinc uptake, and by mobilizing and conserving intracellular zinc pools. Other genes respond only to severe zinc limitation and act as a second line of defense. These second-line defense genes allow cells to adapt to conditions of zinc deficiency and include genes involved in maintaining secretory pathway and cell wall function, and stress responses.</p> <p>Conclusion</p> <p>We have identified several new targets of Zap1-mediated regulation. Furthermore, our results indicate that through the differential regulation of its target genes, Zap1 prioritizes mechanisms of zinc homeostasis and adaptive responses to zinc deficiency.</p
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