23 research outputs found

    Protein Kinase C Activation Has Distinct Effects on the Localization, Phosphorylation and Detergent Solubility of the Claudin Protein Family in Tight and Leaky Epithelial Cells

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    We have previously shown that protein kinase C (PKC) activation has distinct effects on the structure and barrier properties of cultured epithelial cells (HT29 and MDCK I). Since the claudin family of tight junction (TJ)-associated proteins is considered to be crucial for the function of mature TJ, we assessed their expression patterns and cellular destination, detergent solubility and phosphorylation upon PKC stimulation for 2 or 18 h with phorbol myristate acetate (PMA). In HT29 cells, claudins 1, 3, 4 and 5 and possibly claudin 2 were redistributed to apical cell–cell contacts after PKC activation and the amounts of claudins 1, 3 and 5, but not of claudin 2, were increased in cell lysates. By contrast, in MDCK I cells, PMA treatment resulted in redistribution of claudins 1, 3, 4 and 5 from the TJ and in reorganization of the proteins into more insoluble complexes. Claudins 1 and 4 were phosphorylated in both MDCK I and HT29 cells, but PKC-induced changes in claudin phosphorylation state were detected only in MDCK I cells. A major difference between HT29 and MDCK I cells, which have low and high basal transepithelial electrical resistance, respectively, was the absence of claudin 2 in the latter. Our findings show that PKC activation targets in characteristic ways the expression patterns, destination, detergent solubility and phosphorylation state of claudins in epithelial cells with different capacities to form an epithelial barrier

    International physical activity questionnaire: 12-country reliability and validity,”

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    Background: Physical inactivity is a global concern, but diverse physical activity measures in use prevent international comparisons. The International Physical Activity Questionnaire (IPAQ) was developed as an instrument for cross-national monitoring of physical activity and inactivity. Methods: Between 1997 and 1998, an International Consensus Group developed four long and four short forms of the IPAQ instruments (administered by telephone interview or self-administration, with two alternate reference periods, either the "last 7 d" or a "usual week" of recalled physical activity). During 2000, 14 centers from 12 countries collected reliability and/or validity data on at least two of the eight IPAQ instruments. Test-retest repeatability was assessed within the same week. Concurrent (inter-method) validity was assessed at the same administration, and criterion IPAQ validity was assessed against the CSA (now MTI) accelerometer. Spearman's correlation coefficients are reported, based on the total reported physical activity. Results: Overall, the IPAQ questionnaires produced repeatable data (Spearman's clustered around 0.8), with comparable data from short and long forms. Criterion validity had a median of about 0.30, which was comparable to most other self-report validation studies. The "usual week" and "last 7 d" reference periods performed similarly, and the reliability of telephone administration was similar to the self-administered mode. Conclusions: The IPAQ instruments have acceptable measurement properties, at least as good as other established self-reports. Considering the diverse samples in this study, IPAQ has reasonable measurement properties for monitoring population levels of physical activity among 18-to 65-yr-old adults in diverse settings. The short IPAQ form "last 7 d recall" is recommended for national monitoring and the long form for research requiring more detailed assessment

    Lymphoma of the lacrimal gland - An International Multicenter Retrospective Study.

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    PURPOSE:To characterize the clinical features of subtype-specific lacrimal gland lymphoma and their effect on patient survival. DESIGN:Multi-center retrospective interventional case series. METHODS:Patient data were collected from 6 international eye cancer centers from January 1, 1980 through December 31, 2017. All patients with histologically verified primary or secondary lymphoma of the lacrimal gland were included. Primary endpoints were overall survival (OS) and disease-specific survival (DSS). RESULTS:260 patients with lacrimal gland lymphoma were identified. The median age was 58 years and 52% of patients were men. Non-Hodgkin B-cell lymphomas constituted 99% (n=258) and T-cell lymphomas constituted 1% (n=2). The most frequent lymphoma subtypes were extranodal marginal zone B-cell lymphoma (EMZL) (n=177, 68%), follicular lymphoma (FL) (n=26, 10%), diffuse large B-cell lymphoma (DLBCL) (n=25, 10%), and mantle cell lymphoma (MCL) (n=17, 7%). Low-grade lymphomas (EMZL and FL) were most commonly treated with external beam radiotherapy (EBRT), whereas high-grade lymphomas (DLBCL and MCL) were treated with chemotherapy in combination with Rituximab and/or EBRT. The prognosis was relatively good with a 5-year OS and DSS of 73.8% and 87.5%, respectively. Lymphoma subtype was a statistically significant predictor for DSS with EMZL (5-year DSS: 93.4%) having the best prognosis, and DLBCL (5-year DSS: 52.6%) having the poorest. CONCLUSIONS:This is the largest reported collection of data of subtype-specific lacrimal gland lymphoma. The subtype distribution of lacrimal gland lymphoma resembles that of the ocular adnexa. Prognosis is good and the histologic subtype is a significant predictor for disease-specific survival
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