159 research outputs found

    Further observations on mechanisms of bone destruction by squamous carcinomas of the head and neck: the role of host stroma.

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    Mechanisms of bone invasion by squamous carcinomas of the head and neck have been investigated using fresh tumours and established tumour cell lines in an in vitro bone resorption assay with 45Ca-labelled mouse calvaria. Fresh tumours regularly resorb bone in vitro. Activity is consistently reduced by indomethacin. The tumours release E2 prostaglandins (PGE2) in amounts sufficient to account for approximately 50% of the bone resorption observed. Small amounts of non-prostaglandin (indomethacin-resistant) osteolytic factors are also produced. Control non-neoplastic tissues show a variable capacity to resorb bone in vitro; PGE2 levels in these tissues may be related to their content of inflammatory cells. Tumour cell lines also resorb bone in vitro but, for most lines, activity is not significantly blocked by indomethacin and PGE2 levels are generally insufficient to account for the osteolysis observed. Non-prostaglandin bone resorbing factors thus predominate. It is concluded that most squamous cancers of the head and neck are osteolytic in vitro and release a mixture of prostaglandin and non-prostaglandin factors which stimulate osteoclastic bone resorption. These factors are derived from both neoplastic and stromal elements, and are "tumour-associated" rather than "tumour-specific". In vitro bone resorption and prostaglandin release does not correlate with pathological features of the tumour or with post-operative survival

    Using the Voice to Design Ceramics

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    The role of student expectations in TESOL: Opening a research agenda

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    Childhood, adolescent, and adulthood adiposity are associated with risk of PCOS: a Mendelian randomization study with meta-analysis.

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    Study questionWhat is the influence of body composition during childhood, adolescence, and adulthood, as well as metabolic parameters, on incident polycystic ovary syndrome (PCOS)?Summary answerExcess body fat, even during childhood/adolescence, and metabolic parameters, suggestive of hyperinsulinaemia/insulin resistance, significantly impact the risk of PCOS in a linear fashion.What is known alreadyObservational and Mendelian randomization (MR) data have demonstrated an association between adulthood overweight/obesity and development of PCOS. However, the contribution of body composition in childhood/adolescence to incident PCOS is unclear, as is the influence of childhood overweight/obesity.Study design, size, durationWe conducted a systematic review and meta-analysis and integrated our results with a previously published systematic review. Two blinded investigators screened abstracts published between November 2010 and May 2021. Furthermore, we incorporated summary statistics from genome-wide association study (GWAS) data in subjects of European ancestry. Adult overweight was defined as BMI ≥ 25 kg/m2 and obesity as BMI ≥ 30 kg/m2; in Asian subjects, overweight was defined as BMI ≥ 23 kg/m2 and obesity as BMI ≥ 25 kg/m2.Participants/materials, setting, methodsWe utilized meta-analysis and MR together to allow synthesis of genetic and observational data. For the systematic review, the search revealed 71 studies, of which 63 were included in meta-analysis by calculating odds ratios (ORs) using the random-effects model. Furthermore, we conducted a two-sample MR study of GWAS data to determine the impact of childhood and adult body size (defined categorically by BMI and childhood body size proportions), abnormal body composition and metabolic parameters (higher fasting serum insulin or lower sex hormone-binding globulin (SHBG) concentration) on the odds of incident PCOS via the inverse-variance weighted method.Main results and the role of chanceSignificant associations were shown between body composition and PCOS incidence. From the systematic review/meta-analysis, women with overweight (OR 3.80, 2.87-5.03), obesity (OR 4.99, 3.74-6.67), and central obesity (OR 2.93, 2.08-4.12) had increased odds of PCOS. For adolescents with overweight and/or obesity, the PCOS odds were greater than for adults. From MR, for every standard deviation increase in BMI (4.8 kg/m2), the odds of PCOS increased by 2.76 (2.27-3.35). Childhood body size had an independent effect on PCOS odds after adjusting for adult body size (OR: 2.56, 1.57-4.20). Genetically determined body fat percentage (OR 3.05, 2.24-4.15), whole body fat mass (OR 2.53, 2.04-3.14), fasting serum insulin (OR 6.98, 2.02-24.13), and SHBG concentration (OR 0.74, 0.64-0.87) were all significantly associated with PCOS in a linear relation.Limitations, reasons for cautionThe meta-analysis included studies which were cross-sectional and retrospective, limiting our ability to determine causality. MR was limited by interrogating subjects only of European ancestry and including cases classified by either self-diagnosis or diagnostic criteria.Wider implications of the findingsOur study demonstrates for the first time a critical role of the impact of excess childhood/adolescent adiposity on the pathophysiology of adult PCOS. Our results, driven by genetically determined childhood/adolescent body composition, higher BMI, hyperinsulinaemia, and lower SHBG, clearly favour obesity driving the metabolic, but not reproductive, PCOS phenotype. Overall, effective weight maintenance, even from the early years, is likely to reduce the risk of this reproductive endocrine disorder.Study funding/competing interest(s)S.S.Z. was funded by a National Institute for Health and Care Research (NIHR) Academic Clinical Lectureship. U.A. is chair of the NIHR Steering Committee Trial-CASSANDRA-DN. No other authors declare any sources of funding or relevant conflicts of interest. The authors declare that the research was conducted in the absence of any commercial or financial relations that could be construed as a potential conflict of interest.Trial registration numberN/A

    Neutrino and Antineutrino Inclusive Charged-current Cross Section Measurements with the MINOS Near Detector

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    The energy dependence of the neutrino-iron and antineutrino-iron inclusive charged-current cross sections and their ratio have been measured using a high-statistics sample with the MINOS Near Detector exposed to the NuMI beam from the Main Injector at Fermilab. Neutrino and antineutrino fluxes were determined using a low hadronic energy subsample of charged-current events. We report measurements of neutrino-Fe (antineutrinoFe) cross section in the energy range 3-50 GeV (5-50 GeV) with precision of 2-8% (3-9%) and their ratio which is measured with precision 2-8%. The data set spans the region from low energy, where accurate measurements are sparse, up to the high-energy scaling region where the cross section is well understood.Comment: accepted by PR

    Testing Lorentz Invariance and CPT Conservation with NuMI Neutrinos in the MINOS Near Detector

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    A search for a sidereal modulation in the MINOS near detector neutrino data was performed. If present, this signature could be a consequence of Lorentz and CPT violation as predicted by a class of extensions to the Standard Model. No evidence for a sidereal signal in the data set was found, implying that there is no significant change in neutrino propagation that depends on the direction of the neutrino beam in a sun-centered inertial frame. Upper limits on the magnitudes of the Lorentz and CPT violating terms in these extensions to the Standard Model lie between 0.01-1% of the maximum expected, assuming a suppression of these signatures by factor of 10−1710^{-17}.
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