2,709 research outputs found

    Involvement of intact inositol-1,4,5-trisphosphate-sensitive Ca2+ stores in cell cycle progression at the G1/S boundary in serum-stimulated human fibroblasts

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    AbstractThapsigargin, a selective inhibitor of the endoplasmic reticulum Ca2+ pump, has been shown to deplete inositol-1,4,5-trisphosphate-sensitive Ca2+ stores. Here we report that when thapsigargin was introduced to serum-stimulated human fibroblasts at a time point just before the G1/S boundary, it completely inhibited expression of cyclin A, activation of p33CDK2 cyclindependent kinase and initiation of DNA synthesis. In contrast, the Ca2+ mobilizing ionophore ionomycin was without effect. These findings indicate that Ca2+ inside the inositol-1,4,5-trisphosphatesensitive Ca2+ stores plays a pivotal role for traverse across the G1/S transition point

    Dental caries in Mexican schoolchildren : a comparison of 1988?1989 and 1998?2001 surveys

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    Objectives: To compare two surveys across seven states for the prevalence of dental caries among Mexican schoolchildren. Study D esign: Analysis of two cross-sectional surveys: Schoolchildren from 6 to 10 years of age were examined in the 1988?1989 survey and 6- to 10-year-old and 12-year-old students were included in the 1998?2001 survey. The baseline data of seven states were available for analysis. Representative probability samples were conducted statewide in both surveys. The World Health Organization (WHO) method was used to obtain the dental caries index (dmft, DMFT). At present, additional and more recent epidemiological data representative statewide in Mexico are unavailable. Results: The participants were 9798 schoolchildren in the 1988?1989 survey and 16882 schoolchildren in the 1998?2001 survey. The prevalence of caries in children ages 6 to 10 years was 86,6% in the first survey and 65,5% in the second survey, showing a 24,4% reduction. The primary teeth index in the first survey was dmft = 3,86 (IC95% 3,68 4,04) and in permanent teeth, it was DMFT = 1,03 (IC95% 0,95 1,11). In the second survey, the comparable values were dmft = 2,36 (IC95% 2,20 2,52) and DMFT = 0,35 (IC95% 0,29 0,40), corresponding to a reduction of 38,89% and 66,02% in the primary and permanent dentition, respectively. Treatment needs remain high: In the second survey, as 92,75% of the index DMFT was conformed as decayed teeth. Conclusion: Overall, we detected a downward trend in the dental caries indices, particularly in the permanent dentition. The increase in the availability of fluoride likely contributed to the observed decline in dental carie

    Beta-cell mass adaptation to ileum nutrient flow. An experimental model

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    The population with obesity has increased at an alarming rate during this century. Bariatric surgery has been demonstrated to be a good method to control weight and, most importantly, associated comorbidities, such as type 2 diabetes mellitus or high blood pressure. The reason why this happens even before losing significant weight remains unclear. Many authors believe that incretins play a main role, triggering special functions of the digestive tract. In reports, these hypotheses are known as foregut and hindgut theories. Initially, the theories were mutually exclusive; additionally, many other propositions have been analysed, according to different surgical techniques (e.g., bile acids and specific enterohormonal components). To elucidate the participation of the ileum, we developed a surgical technique to study the rapid response to nutrients in the ileum. Our goal was to study the stress functional test and histological changes in the pancreas that may explain the variations in glycaemic homeostasis in our rat model. After the oral glucose tolerance test, the experimental group presented an increased insulin release response with conserved glycaemia. We report an increasing beta-cell mass in the experimental group (+11.87 mg vs. +9.65 mg, respectively), while alpha-cell mass was not different. Based on transcription factors, the pathways that were increased were the proliferation process (as the number of PCNA-positive cells in the experimental group versus sham (+12.06 vs. +6.2 PCNA+ cells/mm2)) and transdifferentiation (ARX; +2.67 ARX+ cells/mm2 in the experimental group vs. +2.04 ARX+ cells/mm2 in the controls). We report the consequences of the rapid arrival of nonprocessed nutrients to the ileum on the endocrine cellular pancreas. The ileum could be a principal effector in the enterohormonal axis, which conditions endocrine pancreas cellularit

    Improved guidance is needed to optimise diagnostics and treatment of patients with thyroid cancer in Europe

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    Although thyroid cancer (TC) is generally associated with a favourable prognosis, there are certain high-risk groups with a clear unmet therapeutic need. Unravelling the genomic landscape of TC has recently led to the development of novel effective targeted treatments. To date, these treatments have mostly been evaluated in non-randomised single-arm phase II clinical trials and are consequently non-reimbursed in several countries. Furthermore, most of these agents must be tailored to individual patient molecular characteristics, a context known as personalised cancer medicine, necessitating a requirement for predictive molecular biomarker testing. Existing guidelines, both in Europe and internationally, entail mostly therapeutic rather than molecular testing recommendations. This may reflect ambiguity among experts due to lack of evidence and also practical barriers in availability of the preferred molecular somatic screening and/or targeted treatments. This article reviews existing European recommendations regarding advanced/metastatic TC management with a special focus on molecular testing, and compares findings with real-world practice based on a recent survey involving TC experts from 18 European countries. Significant disparities are highlighted between theory and practice related to variable access to infrastructure, therapies and expertise, together with the insufficient availability of multidisciplinary tumour boards. In particular, practitioners’ choice of what, how and when to test is shown to be influenced by the expertise of the available laboratory, the financing source and the existence of potential facilitators, such as clinical trial access. Overall, the need of a collaborative initiative among European stakeholders to develop standardised, accessible molecular genotyping approaches in TC is underscored.</p

    Improved guidance is needed to optimise diagnostics and treatment of patients with thyroid cancer in Europe

    Get PDF
    Although thyroid cancer (TC) is generally associated with a favourable prognosis, there are certain high-risk groups with a clear unmet therapeutic need. Unravelling the genomic landscape of TC has recently led to the development of novel effective targeted treatments. To date, these treatments have mostly been evaluated in non-randomised single-arm phase II clinical trials and are consequently non-reimbursed in several countries. Furthermore, most of these agents must be tailored to individual patient molecular characteristics, a context known as personalised cancer medicine, necessitating a requirement for predictive molecular biomarker testing. Existing guidelines, both in Europe and internationally, entail mostly therapeutic rather than molecular testing recommendations. This may reflect ambiguity among experts due to lack of evidence and also practical barriers in availability of the preferred molecular somatic screening and/or targeted treatments. This article reviews existing European recommendations regarding advanced/metastatic TC management with a special focus on molecular testing, and compares findings with real-world practice based on a recent survey involving TC experts from 18 European countries. Significant disparities are highlighted between theory and practice related to variable access to infrastructure, therapies and expertise, together with the insufficient availability of multidisciplinary tumour boards. In particular, practitioners’ choice of what, how and when to test is shown to be influenced by the expertise of the available laboratory, the financing source and the existence of potential facilitators, such as clinical trial access. Overall, the need of a collaborative initiative among European stakeholders to develop standardised, accessible molecular genotyping approaches in TC is underscored.</p

    Long range absorption in the scattering of 6He on 208Pb and 197Au at 27 MeV

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    Quasi-elastic scattering of 6He at E_lab=27 MeV from 197Au has been measured in the angular range of 6-72 degrees in the laboratory system employing LEDA and LAMP detection systems. These data, along with previously analysed data of 6He + 208Pb at the same energy, are analyzed using Optical Model calculations. The role of Coulomb dipole polarizability has been investigated. Large imaginary diffuseness parameters are required to fit the data. This result is an evidence for long range absorption mechanisms in 6He induced reactions.Comment: 10 pages, 10 figures, minor corrections. To appear in Nucl. Phys.

    Scattering of the Halo Nucleus Be 11 on Au 197 at Energies around the Coulomb Barrier

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    Angular distributions of the elastic, inelastic, and breakup cross sections of the halo nucleus Be11 on Au197 were measured at energies below (Elab=31.9 MeV) and around (39.6 MeV) the Coulomb barrier. These three channels were unambiguously separated for the first time for reactions of Be11 on a high-Z target at low energies. The experiment was performed at TRIUMF (Vancouver, Canada). The differential cross sections were compared with three different calculations: semiclassical, inert-core continuum-coupled-channels and continuum-coupled-channels ones with including core deformation. These results show conclusively that the elastic and inelastic differential cross sections can only be accounted for if core-excited admixtures are taken into account. The cross sections for these channels strongly depend on the B(E1) distribution in Be11, and the reaction mechanism is sensitive to the entanglement of core and halo degrees of freedom in Be11

    Measurement of the Crab Nebula Spectrum Past 100 TeV with HAWC

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    We present TeV gamma-ray observations of the Crab Nebula, the standard reference source in ground-based gamma-ray astronomy, using data from the High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory. In this analysis we use two independent energy-estimation methods that utilize extensive air shower variables such as the core position, shower angle, and shower lateral energy distribution. In contrast, the previously published HAWC energy spectrum roughly estimated the shower energy with only the number of photomultipliers triggered. This new methodology yields a much improved energy resolution over the previous analysis and extends HAWC's ability to accurately measure gamma-ray energies well beyond 100 TeV. The energy spectrum of the Crab Nebula is well fit to a log parabola shape (dNdE=ϕ0(E/7 TeV)αβln(E/7 TeV))\left(\frac{dN}{dE} = \phi_0 \left(E/\textrm{7 TeV}\right)^{-\alpha-\beta\ln\left(E/\textrm{7 TeV}\right)}\right) with emission up to at least 100 TeV. For the first estimator, a ground parameter that utilizes fits to the lateral distribution function to measure the charge density 40 meters from the shower axis, the best-fit values are ϕo\phi_o=(2.35±\pm0.040.21+0.20^{+0.20}_{-0.21})×\times1013^{-13} (TeV cm2^2 s)1^{-1}, α\alpha=2.79±\pm0.020.03+0.01^{+0.01}_{-0.03}, and β\beta=0.10±\pm0.010.03+0.01^{+0.01}_{-0.03}. For the second estimator, a neural network which uses the charge distribution in annuli around the core and other variables, these values are ϕo\phi_o=(2.31±\pm0.020.17+0.32^{+0.32}_{-0.17})×\times1013^{-13} (TeV cm2^2 s)1^{-1}, α\alpha=2.73±\pm0.020.02+0.03^{+0.03}_{-0.02}, and β\beta=0.06±\pm0.01±\pm0.02. The first set of uncertainties are statistical; the second set are systematic. Both methods yield compatible results. These measurements are the highest-energy observation of a gamma-ray source to date.Comment: published in Ap

    Search for Neutral Higgs Bosons in Events with Multiple Bottom Quarks at the Tevatron

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    The combination of searches performed by the CDF and D0 collaborations at the Fermilab Tevatron Collider for neutral Higgs bosons produced in association with b quarks is reported. The data, corresponding to 2.6 fb-1 of integrated luminosity at CDF and 5.2 fb-1 at D0, have been collected in final states containing three or more b jets. Upper limits are set on the cross section multiplied by the branching ratio varying between 44 pb and 0.7 pb in the Higgs boson mass range 90 to 300 GeV, assuming production of a narrow scalar boson. Significant enhancements to the production of Higgs bosons can be found in theories beyond the standard model, for example in supersymmetry. The results are interpreted as upper limits in the parameter space of the minimal supersymmetric standard model in a benchmark scenario favoring this decay mode.Comment: 10 pages, 2 figure
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