496 research outputs found

    No germline mutations in the histone acetyltransferase gene EP300 in BRCA1 and BRCA2 negative families with breast cancer and gastric, pancreatic, or colorectal cancer

    Get PDF
    INTRODUCTION: Mutations in BRCA1, BRCA2, ATM, TP53, CHK2 and PTEN account for many, but not all, multiple-case breast and ovarian cancer families. The histone acetyltransferase gene EP300 may function as a tumour suppressor gene because it is sometimes somatically mutated in breast, colorectal, gastric and pancreatic cancers, and is located on a region of chromosome 22 that frequently undergoes loss of heterozygosity in many cancer types. We hypothesized that germline mutations in EP300 may account for some breast cancer families that include cases of gastric, pancreatic and/or colorectal cancer. METHODS: We screened the entire coding region of EP300 for mutations in the youngest affected members of 23 non-BRCA1/BRCA2 breast cancer families with at least one confirmed case of gastric, pancreatic and/or colorectal cancer. These families were ascertained in Australia through the Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer. RESULTS: Denaturing HPLC analysis identified a heterozygous alteration at codon 211, specifically a GGC to AGC (glycine to serine) alteration, in two individuals. This conservative amino acid change was not within any known functional domains of EP300. The frequency of the Ser211 variant did not differ significanlty between a series of 352 breast cancer patients (4.0%) and 254 control individuals (2.8%; P = 0.5). CONCLUSION: The present study does not support a major role for EP300 mutations in breast and ovarian cancer families with a history of gastric, pancreatic and/or colorectal cancer

    The birth of airplane stability theory

    Full text link
    Airplane stability theory was born at the end of the XIX century and matured around 100 years ago, when airplanes were hardly controllable yet. The success and safety of flights in the pioneer years depended upon largely unknown stability and control characteristics. Understanding the modes of airplane motion has been of paramount importance for the development of aviation. The contributions made by a few scientists in the decades preceding and following the first flight by the Wright brothers set the concepts and equations that, with minor notation aspects, have remained almost unchanged till present day.Magraner Rullan, JP.; Martinez-Val, R. (2014). The birth of airplane stability theory. Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering. 228(9):1498-1506. doi:10.1177/0954410013494139S149815062289PERKINS, C. D. (1970). Development of airplane stability and control technology /1970 Von Karman Lecture/. Journal of Aircraft, 7(4), 290-301. doi:10.2514/3.44167Abzug, M. J., & Larrabee, E. E. (2002). Airplane Stability and Control, Second Edition. doi:10.1017/cbo9780511607141Graham, W. R. (1999). Asymptotic analysis of the classical aircraft stability equations. The Aeronautical Journal, 103(1020), 95-103. doi:10.1017/s0001924000027792Bryan, G. H., & Williams, W. E. (1904). The Longitudinal Stability of Aerial Gliders. Proceedings of the Royal Society of London, 73(488-496), 100-116. doi:10.1098/rspl.1904.0017Wegener, P. P. (1997). What Makes Airplanes Fly? doi:10.1007/978-1-4612-2254-5Pradeep, S., & Kamesh, S. (1999). Does the Phugoid Frequency Depend on Speed? Journal of Guidance, Control, and Dynamics, 22(2), 372-373. doi:10.2514/2.4391Phillips, W. F. (2000). Phugoid Approximation for Conventional Airplanes. Journal of Aircraft, 37(1), 30-36. doi:10.2514/2.2586Pamadi, B. N. (2004). Performance, Stability, Dynamics, and Control of Airplanes, Second Edition. doi:10.2514/4.862274Ananthkrishnan, N., & Ramadevi, P. (2002). Consistent Approximations to Aircraft Longitudinal Modes. Journal of Guidance, Control, and Dynamics, 25(4), 820-824. doi:10.2514/2.4952McRuer, D. T., Graham, D., & Ashkenas, I. (1990). Aircraft Dynamics and Automatic Control. doi:10.1515/978140085598

    The Epstein-Barr Virus G-Protein-Coupled Receptor Contributes to Immune Evasion by Targeting MHC Class I Molecules for Degradation

    Get PDF
    Epstein-Barr virus (EBV) is a human herpesvirus that persists as a largely subclinical infection in the vast majority of adults worldwide. Recent evidence indicates that an important component of the persistence strategy involves active interference with the MHC class I antigen processing pathway during the lytic replication cycle. We have now identified a novel role for the lytic cycle gene, BILF1, which encodes a glycoprotein with the properties of a constitutive signaling G-protein-coupled receptor (GPCR). BILF1 reduced the levels of MHC class I at the cell surface and inhibited CD8+ T cell recognition of endogenous target antigens. The underlying mechanism involves physical association of BILF1 with MHC class I molecules, an increased turnover from the cell surface, and enhanced degradation via lysosomal proteases. The BILF1 protein of the closely related CeHV15 c1-herpesvirus of the Rhesus Old World primate (80% amino acid sequence identity) downregulated surface MHC class I similarly to EBV BILF1. Amongst the human herpesviruses, the GPCR encoded by the ORF74 of the KSHV c2-herpesvirus is most closely related to EBV BILF1 (15% amino acid sequence identity) but did not affect levels of surface MHC class I. An engineered mutant of BILF1 that was unable to activate G protein signaling pathways retained the ability to downregulate MHC class I, indicating that the immune-modulating and GPCR-signaling properties are two distinct functions of BILF1. These findings extend our understanding of the normal biology of an important human pathogen. The discovery of a third EBV lytic cycle gene that cooperates to interfere with MHC class I antigen processing underscores the importance of the need for EBV to be able to evade CD8+ T cell responses during the lytic replication cycle, at a time when such a large number of potential viral targets are expressed

    Comparing United States and Canadian population exposures from National Biomonitoring Surveys: Bisphenol A intake as a case study

    Get PDF
    The Centers for Disease Control and Prevention provides biomonitoring data in the United States as part of the National Health and Nutrition Examination Survey (NHANES). Recently, Statistics Canada initiated a similar survey — the Canadian Health Measures Survey (CHMS). Comparison of US and Canadian biomonitoring data can generate hypotheses regarding human exposures from environmental media and consumer products. To ensure that such comparisons are scientifically meaningful, it is essential to first evaluate aspects of the surveys' methods that can impact comparability of data. We examined CHMS and NHANES methodologies, using bisphenol A (BPA) as a case study, to evaluate whether survey differences exist that would hinder our ability to compare chemical concentrations between countries. We explored methods associated with participant selection, urine sampling, and analytical methods. BPA intakes were also estimated to address body weight differences between countries. Differences in survey methods were identified but are unlikely to have substantial impacts on inter-survey comparisons of BPA intakes. BPA intakes for both countries are below health-based guidance values set by the US, Canada and the European Food Safety Authority. We recommend that before comparing biomonitoring data between surveys, a thorough review of methodologic aspects that might impact biomonitoring results be conducted

    Tumor collagenase stimulatory factor (TCSF) expression and localization in human lung and breast cancers.

    Full text link
    Tumor cell-derived collagenase stimulatory factor (TCSF) stimulates in vitro the biosynthesis of various matrix metalloproteinases involved in tumor invasion, such as interstitial collagenase, gelatinase A, and stromelysin 1. The expression of TCSF mRNAs was studied in vivo, using in situ hybridization and Northern blotting analysis, in seven normal tissues and in 22 squamous cell carcinomas of the lung, and in seven benign proliferations and in 22 ductal carcinomas of the mammary gland. By in situ hybridization, TCSF mRNAs were detected in 40 of 44 carcinomas, in pre-invasive and invasive cancer cells of both lung and breast cancers. TCSF mRNAs and gelatinase A mRNAs were both visualized in the same areas in serial sections in breast cancers, and were expressed by different cells, tumor cells, and fibroblasts. The histological results were confirmed by Northern blot analysis, which showed a higher expression of TCSF mRNAs in cancers than in benign and normal tissues. These observations support the hypothesis that TCSF is an important factor in lung and breast tumor progression

    Observing response processes with eye tracking in international large-scale assessments: evidence from the OECD PIAAC assessment

    Get PDF
    This paper reports on a pilot study that used eye tracking techniques to make detailed observations of item response processes in the OECD Programme for the International Assessment of Adult Competencies (PIAAC). The lab-based study also recorded physiological responses using measures of pupil diameter and electrodermal activity. The study tested 14 adult respondents as they individually completed the PIAAC computer-based assessment. The eye tracking observations help to fill an ‘explanatory gap’ by providing data on variation in item response processes that are not captured by other sources of process data such as think aloud protocols or computer-generated log files. The data on fixations and saccades provided detailed information on test item response strategies, enabling profiling of respondent engagement and response processes associated with successful performance. Much of that activity does not include the use of the keyboard and mouse, and involves ‘off-screen’ use of pen and paper (and calculator) that are not captured by assessment log-files. In conclusion, this paper points toward an important application of eye tracking in large-scale assessments. This includes insights into response processes in new domains such as adaptive problem-solving that aim to identify individuals’ ability to select and combine resources from the digital and physical environment

    Localization of telomeres and telomere-associated proteins in telomerase-negative Saccharomyces cerevisiae

    Get PDF
    Cells lacking telomerase cannot maintain their telomeres and undergo a telomere erosion phase leading to senescence and crisis in which most cells become nonviable. On rare occasions survivors emerge from these cultures that maintain their telomeres in alternative ways. The movement of five marked telomeres in Saccharomyces cerevisiae was followed in wild-type cells and through erosion, senescence/crisis and eventual survival in telomerase-negative (est2::HYG) yeast cells. It was found that during erosion, movements of telomeres in est2::HYG cells were indistinguishable from wild-type telomere movements. At senescence/crisis, however, most cells were in G2 arrest and the nucleus and telomeres traversed back and forth across the bud neck, presumably until cell death. Type I survivors, using subtelomeric Y′ amplification for telomere maintenance, continued to show this aberrant telomere movement. However, Type II survivors, maintaining telomeres by a sudden elongation of the telomere repeats, became indistinguishable from wild-type cells, consistent with growth properties of the two types of survivors. When telomere-associated proteins Sir2p, Sir3p and Rap1p were tagged, the same general trend was seen—Type I survivors retained the senescence/crisis state of protein localization, while Type II survivors were restored to wild type

    Outcome measurement in clinical trials for Ulcerative Colitis: towards standardisation

    Get PDF
    Clinical trials on novel drug therapies require clear criteria for patient selection and agreed definitions of disease remission. This principle has been successfully applied in the field of rheumatology where agreed disease scoring systems have allowed multi-centre collaborations and facilitated audit across treatment centres. Unfortunately in ulcerative colitis this consensus is lacking. Thirteen scoring systems have been developed but none have been properly validated. Most trials choose different endpoints and activity indices, making comparison of results from different trials extremely difficult. International consensus on endoscopic, clinical and histological scoring systems is essential as these are the key components used to determine entry criteria and outcome measurements in clinical trials on ulcerative colitis. With multiple new therapies under development, there is a pressing need for consensus to be reached

    Characterization of a FGF19 Variant with Altered Receptor Specificity Revealed a Central Role for FGFR1c in the Regulation of Glucose Metabolism

    Get PDF
    Diabetes and associated metabolic conditions have reached pandemic proportions worldwide, and there is a clear unmet medical need for new therapies that are both effective and safe. FGF19 and FGF21 are distinctive members of the FGF family that function as endocrine hormones. Both have potent effects on normalizing glucose, lipid, and energy homeostasis, and therefore, represent attractive potential next generation therapies for combating the growing epidemics of type 2 diabetes and obesity. The mechanism responsible for these impressive metabolic effects remains unknown. While both FGF19 and FGF21 can activate FGFRs 1c, 2c, and 3c in the presence of co-receptor βKlotho in vitro, which receptor is responsible for the metabolic activities observed in vivo remains unknown. Here we have generated a variant of FGF19, FGF19-7, that has altered receptor specificity with a strong bias toward FGFR1c. We show that FGF19-7 is equally efficacious as wild type FGF19 in regulating glucose, lipid, and energy metabolism in both diet-induced obesity and leptin-deficient mouse models. These results are the first direct demonstration of the central role of the βKlotho/FGFR1c receptor complex in glucose and lipid regulation, and also strongly suggest that activation of this receptor complex alone might be sufficient to achieve all the metabolic functions of endocrine FGF molecules
    corecore