228 research outputs found

    Harriet Beecher Stowe’s Letters, 1868: A Study

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    This project examines two letters written by Harriet Beecher Stowe, one dated 1868; the other undated. The 1868 letter is personal correspondence sent from Charleston, South Carolina and reveals a surprising connection between Stowe and the Tyler family of Philadelphia (for whom Temple University’s Tyler School of Art is named). The undated letter is addressed to Stowe’s editor and publisher, James T. Fields. In it she includes detailed input on the cover art for the forthcoming Little Pussy Willow (1870), and updates on various shorter writing projects under contract. While the contents of both letters contain rather quotidian details and information, they nevertheless offer a glimpse of Stowe and the business of writing professionally in the nineteenth century—including the packaging, marketing, and promotion of her books, as well as brief insights on her financial compensation for contributions to various periodicals

    A Pathobiont of the Microbiota Balances Host Colonization and Intestinal Inflammation

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    The gastrointestinal tract harbors a diverse microbiota that has coevolved with mammalian hosts. Though most associations are symbiotic or commensal, some resident bacteria (termed pathobionts) have the potential to cause disease. Bacterial type VI secretion systems (T6SSs) are one mechanism for forging host-microbial interactions. Here we reveal a protective role for the T6SS of Helicobacter hepaticus, a Gram-negative bacterium of the intestinal microbiota. H. hepaticus mutants with a defective T6SS display increased numbers within intestinal epithelial cells (IECs) and during intestinal colonization. Remarkably, the T6SS directs an anti-inflammatory gene expression profile in IECs, and CD4+ T cells from mice colonized with T6SS mutants produce increased interleukin-17 in response to IECs presenting H. hepaticus antigens. Thus, the H. hepaticus T6SS limits colonization and intestinal inflammation, promoting a balanced relationship with the host. We propose that disruption of such balances contributes to human disorders such as inflammatory bowel disease and colon cancer

    Pathobionts of the gastrointestinal microbiota and inflammatory disease

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    Our immune system is charged with the vital mission of identifying invading pathogens and mounting proper inflammatory responses. During the process of clearing infections, the immune system often causes considerable tissue damage. Conversely, if the target of immunity is a member of the resident microbiota, uncontrolled inflammation may lead to host pathology in the absence of infectious agents. Recent evidence suggests that several inflammatory disorders may be caused by specific bacterial species found in most healthy hosts. Although the mechanisms that mediate pathology remain largely unclear, it appears that genetic defects and/or environmental factors may predispose mammals to immune-mediated diseases triggered by potentially pathogenic symbionts of the microbiota. We have termed this class of microbes ‘pathobionts’, to distinguish them from acquired infectious agents. Herein, we explore burgeoning hypotheses that the combination of an immunocompromised state with colonization by pathobionts together comprise a risk factor for certain inflammatory disorders and gastrointestinal (GI) cancer

    High basal expression of interferon-stimulated genes in human bronchial epithelial (BEAS-2B) cells contributes to influenza A virus resistance

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    Respiratory epithelial cells play a key role in influenza A virus (IAV) pathogenesis and host innate response. Transformed human respiratory cell lines are widely used in the study of IAV−host interactions due to their relative convenience, and inherent difficulties in working with primary cells. Transformed cells, however, may have altered susceptibility to virus infection. Proper characterization of different respiratory cell types in their responses to IAV infection is therefore needed to ensure that the cell line chosen will provide results that are of relevance in vivo. We compared replication kinetics of human H1N1 (A/USSR/77) IAVs in normal primary human bronchial epithelial (NHBE) and two commonly used respiratory epithelial cell lines namely BEAS-2B and A549 cells. We found that IAV replication was distinctly poor in BEAS-2B cells in comparison with NHBE, A549 and Madin-Darby canine kidney (MDCK) cells. IAV resistance in BEAS-2B cells was accompanied by an activated antiviral state with high basal expression of interferon (IFN) regulatory factor-7 (IRF-7), stimulator of IFN genes (STING) and IFN stimulated genes (ISGs). Treatment of BEAS-2B cells with a pan-Janus-activated-kinase (JAK) inhibitor decreased IRF-7 and ISG expression and resulted in increased IAV replication. Therefore, the use of highly resistant BEAS-2B cells in IAV infection may not reflect the cytopathogenicity of IAV in human epithelial cells in vivo

    mab-31 and the TGF-β pathway act in the ray lineage to pattern C. elegans male sensory rays

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    <p>Abstract</p> <p>Background</p> <p><it>C. elegans </it>TGF-β-like Sma/Mab signaling pathway regulates both body size and sensory ray patterning. Most of the components in this pathway were initially identified by genetic screens based on the small body phenotype, and many of these mutants display sensory ray patterning defect. At the cellular level, little is known about how and where these components work although ray structural cell has been implicated as one of the targets. Based on the specific ray patterning abnormality, we aim to identify by RNAi approach additional components that function specifically in the ray lineage to elucidate the regulatory role of TGF-β signaling in ray differentiation.</p> <p>Result</p> <p>We report here the characterization of a new member of the Sma/Mab pathway, <it>mab-31</it>, recovered from a genome-wide RNAi screen. <it>mab-31 </it>mutants showed ray cell cluster patterning defect and mis-specification of the ray identity. <it>mab-31 </it>encodes a nuclear protein expressed in descendants of ray precursor cells impacting on the ray cell's clustering properties, orientation of cell division plane, and fusion of structural cells. Genetic experiments also establish its relationship with other Sma/Mab pathway components and transcription factors acting upstream and downstream of the signaling event.</p> <p>Conclusion</p> <p><it>mab-31 </it>function is indispensable in Sma/Mab signal recipient cells during sensory rays specification. Both <it>mab-31 </it>and <it>sma-6 </it>are required in ray lineage at the late larval stages. They act upstream of <it>C. elegans Pax-6 </it>homolog and repress its function. These findings suggested <it>mab-31 </it>is a key factor that can integrate TFG-β signals in male sensory ray lineage to define organ identity.</p

    Ultrastructure and complex polar architecture of the human pathogen Campylobacter jejuni

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    Campylobacter jejuni is one of the most successful food-borne human pathogens. Here we use electron cryotomography to explore the ultrastructure of C. jejuni cells in logarithmically growing cultures. This provides the first look at this pathogen in a near-native state at macromolecular resolution (~5 nm). We find a surprisingly complex polar architecture that includes ribosome exclusion zones, polyphosphate storage granules, extensive collar-shaped chemoreceptor arrays, and elaborate flagellar motors

    Smoking Status Effect on Inflammatory Markers in a Randomized Trial of Current and Former Heavy Smokers

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    Background. The level of systemic inflammation as measured by circulating levels of C-reactive protein (CRP) and interleukin-6 (IL-6) is linked to an increased risk for cardiovascular diseases (CVD) and cancer. Methods. We recruited 154 current and former smokers between 40 and 80 years of age with 25 or more pack-years of smoking history to study the relationship between inflammatory markers (CRP and IL-6) and smoking status. Results. Our results show that male smokers had significantly higher levels of serum IL-6 compared to male former smokers. We did not find any gender specific differences for smoking and CRP levels but the IL-6 levels were slightly lower in females compared to males. Additionally, our results show that CRP is significantly associated with IL-6 regardless of smoking status. Modelling indicates that the significant predictors of CRP levels were biomarkers of the metabolic syndrome while the significant predictors of IL-6 levels were age and plasma triglycerides among former smokers and the numbers of smoked packs of cigarettes per year among smokers. Conclusions. In conclusion, our study showed that CRP levels were not associated with markers of smoking intensity. However, IL-6 levels were significantly associated with smoking especially among current smokers

    Principal component analysis of dietary and lifestyle patterns in relation to risk of subtypes of esophageal and gastric cancer

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    Purpose To carry out pattern analyses of dietary and lifestyle factors in relation to risk of esophageal and gastric cancers. Methods We evaluated risk factors for esophageal adenocarcinoma (EA), esophageal squamous cell carcinoma (ESCC), gastric cardia adenocarcinoma (GCA), and other gastric cancers (OGA) using data from a population-based case-control study conducted in Connecticut, New Jersey, and western Washington state. Dietary/lifestyle patterns were created using principal component analysis (PCA). The impact of the resultant scores on cancer risk was estimated through logistic regression. Results PCA identified six patterns: meat/nitrite, fruit/vegetable, smoking/alcohol, legume/meat alternate, GERD/BMI, and fish/vitamin C. Risk of each cancer under study increased with rising meat/nitrite score. The risk of EA increased with increasing GERD/BMI score, and the risk of ESCC rose with increasing smoking/alcohol score and decreasing gastroesophageal reflux disease (GERD)/body mass index (BMI) score. Fruit/vegetable scores were inversely associated with EA, ESCC, and GCA. Conclusions PCA may provide a useful approach for summarizing extensive dietary/lifestyle data into fewer interpretable combinations that discriminate between cancer cases and controls. The analyses suggest that meat/nitrite intake is associated with an elevated risk of each cancer under study, whereas fruit/vegetable intake reduces the risk of EA, ESCC, and GCA. GERD/obesity was confirmed as risk factors for EA and smoking/alcohol as risk factors for ESCC
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