792 research outputs found

    Certain triple q-integral equations involving third Jackson qq-Bessel functions as kernel

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    In this paper, we employ the fractional qq-calculus in solving a triple system of qq-Integral equations, where the kernel is the third Jackson qq-Bessel functions. The solution is reduced to two simultaneous Fredholm qq-integral equation of the second kind. Examples are included. We also apply a result in~[Pacific J. Math. \textbf{275}(1) (2015)63--102] for solutions of dual q2q^2-integral equations to solve certain triple integral equations

    Diagnostic value of nuclear cardiology in coronary artery disease

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    This thesis investigates the diagnostic value of cardiac positron emission tomography when compared to single photon emission computed tomography for detection of coronary artery disease. This prospective study involves comparison of myocardial perfusion single photon emission computed tomography with coronary calcium scores; optimization of nuclear cardiac protocols in cardiac phantom experiments; and determination of diagnostic performance of cardiac positron emission tomography in the evaluation of myocardial viability in patients with significant coronary disease

    Hospital Admissions Due to Ischemic Heart Diseases and Prescriptions of Cardiovascular Diseases Medications in England and Wales in the Past Two Decades

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    Objectives: The aim of this study was to explore the trend of ischemic heart disease (IHD) admission and the prescriptions of IHD medications in England and Wales. Methods: A secular trends study was conducted during the period of 1999 to 2019. We extracted hospital admission data for patients from all age groups from the Hospital Episode Statistics database in England and the Patient Episode Database for Wales. Prescriptions of IHD medications were extracted from the Prescription Cost Analysis database from 2004 to 2019. The chi-squared test was used to assess the difference between the admission rates and the difference between IHD medication prescription rates. The trends in IHD-related hospital admission and IHD-related medication prescription were assessed using a Poisson model. The correlation between hospital admissions for IHD and its IHD medication-related prescriptions was assessed using the Pearson correlation coefficient. Results: Our study detected a significant increase in the rate of cardiovascular disease (CVD) medication prescriptions in England and Wales, representing a rise in the CVD medications prescription rate of 41.8% (from 539,334.95 (95% CI = 539,286.30–539,383.59) in 2004 to 764,584.55 (95% CI = 764,545.55–764,623.56) in 2019 prescriptions per 100,000 persons), with a mean increase of 2.8% per year during the past 15 years. This increase was connected with a reduction in the IHD hospital admission rate by 15.4% (from 838.50 (95% CI = 836.05–840.94) in 2004 to 709.78 (95% CI = 707.65–711.92) in 2019 per 100,000 persons, trend test, p < 0.01), with a mean decrease of 1.02% per year during the past 15 years and by 5% (from 747.43 (95% CI = 745.09–749.77) in 1999 to 709.78 (95% CI = 707.65–711.92) in 2019 per 100,000 persons, trend test, p < 0.01) with a mean decrease of 0.25% per year during the past two decades in England and Wales. Conclusion: The rate of hospitalisation due to IHD has decreased in England and Wales during the past two decades. Hospitalisation due to IHD was strongly and negatively correlated with the increase in the rates of dispensing of IHD-related medications. Other factors contributing to this decline could be the increase in controlling IHD risk factors during the past few years. Future studies exploring other risk factors that are associated with IHD hospitalisation are warranted

    The need for national medical licensing examination in Saudi Arabia

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    <p>Abstract</p> <p>Background</p> <p>Medical education in Saudi Arabia is facing multiple challenges, including the rapid increase in the number of medical schools over a short period of time, the influx of foreign medical graduates to work in Saudi Arabia, the award of scholarships to hundreds of students to study medicine in various countries, and the absence of published national guidelines for minimal acceptable competencies of a medical graduate.</p> <p>Discussion</p> <p>We are arguing for the need for a Saudi national medical licensing examination that consists of two parts: Part I (Written) which tests the basic science and clinical knowledge and Part II (Objective Structured Clinical Examination) which tests the clinical skills and attitudes. We propose this examination to be mandated as a licensure requirement for practicing medicine in Saudi Arabia.</p> <p>Conclusion</p> <p>The driving and hindering forces as well as the strengths and weaknesses of implementing the licensing examination are discussed in details in this debate.</p

    The E3 ligase HUWE1 inhibition as a therapeutic strategy to target MYC in multiple myeloma

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    Proteasome inhibitors have provided a significant advance in the treatment of multiple myeloma (MM). Consequently, there is increasing interest in developing strategies to target E3 ligases, de-ubiquitinases, and/or ubiquitin receptors within the ubiquitin proteasome pathway, with an aim to achieve more specificity and reduced side-effects. Previous studies have shown a role for the E3 ligase HUWE1 in modulating c-MYC, an oncogene frequently dysregulated in MM. Here we investigated HUWE1 in MM. We identified elevated expression of HUWE1 in MM compared with normal cells. Small molecule-mediated inhibition of HUWE1 resulted in growth arrest of MM cell lines without significantly effecting the growth of normal bone marrow cells, suggesting a favorable therapeutic index. Studies using a HUWE1 knockdown model showed similar growth inhibition. HUWE1 expression positively correlated with MYC expression in MM bone marrow cells and correspondingly, genetic knockdown and biochemical inhibition of HUWE1 reduced MYC expression in MM cell lines. Proteomic identification of HUWE1 substrates revealed a strong association of HUWE1 with metabolic processes in MM cells. Intracellular glutamine levels are decreased in the absence of HUWE1 and may contribute to MYC degradation. Finally, HUWE1 depletion in combination with lenalidomide resulted in synergistic anti-MM activity in both in vitro and in vivo models. Taken together, our data demonstrate an important role of HUWE1 in MM cell growth and provides preclinical rationale for therapeutic strategies targeting HUWE1 in MM

    Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

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    Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

    A case of autism with an interstitial deletion on 4q leading to hemizygosity for genes encoding for glutamine and glycine neurotransmitter receptor sub-units (AMPA 2, GLRA3, GLRB) and neuropeptide receptors NPY1R, NPY5R

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    BACKGROUND: Autism is a pervasive developmental disorder characterized by a triad of deficits: qualitative impairments in social interactions, communication deficits, and repetitive and stereotyped patterns of behavior. Although autism is etiologically heterogeneous, family and twin studies have established a definite genetic basis. The inheritance of idiopathic autism is presumed to be complex, with many genes involved; environmental factors are also possibly contributory. The analysis of chromosome abnormalities associated with autism contributes greatly to the identification of autism candidate genes. CASE PRESENTATION: We describe a child with autistic disorder and an interstitial deletion on chromosome 4q. This child first presented at 12 months of age with developmental delay and minor dysmorphic features. At 4 years of age a diagnosis of Pervasive Developmental Disorder was made. At 11 years of age he met diagnostic criteria for autism. Cytogenetic studies revealed a chromosome 4q deletion. The karyotype was 46, XY del 4 (q31.3-q33). Here we report the clinical phenotype of the child and the molecular characterization of the deletion using molecular cytogenetic techniques and analysis of polymorphic markers. These studies revealed a 19 megabase deletion spanning 4q32 to 4q34. Analysis of existing polymorphic markers and new markers developed in this study revealed that the deletion arose on a paternally derived chromosome. To date 33 genes of known or inferred function are deleted as a consequence of the deletion. Among these are the AMPA 2 gene that encodes the glutamate receptor GluR2 sub-unit, GLRA3 and GLRB genes that encode glycine receptor subunits and neuropeptide Y receptor genes NPY1R and NPY5R. CONCLUSIONS: The deletion in this autistic subject serves to highlight specific autism candidate genes. He is hemizygous for AMPA 2, GLRA3, GLRB, NPY1R and NPY5R. GluR2 is the major determinant of AMPA receptor structure. Glutamate receptors maintain structural and functional plasticity of synapses. Neuropeptide Y and its receptors NPY1R and NPY5R play a role in hippocampal learning and memory. Glycine receptors are expressed in very early cortical development. Molecular cytogenetic studies and DNA sequence analysis in other patients with autism will be necessary to confirm that these genes are involved in autism

    Mosaic RAS/MAPK variants cause sporadic vascular malformations which respond to targeted therapy.

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    BACKGROUND: Sporadic vascular malformations (VMs) are complex congenital anomalies of blood vessels that lead to stroke, life-threatening bleeds, disfigurement, overgrowth, and/or pain. Therapeutic options are severely limited, and multidisciplinary management remains challenging, particularly for high-flow arteriovenous malformations (AVM). METHODS: To investigate the pathogenesis of sporadic intracranial and extracranial VMs in 160 children in which known genetic causes had been excluded, we sequenced DNA from affected tissue and optimized analysis for detection of low mutant allele frequency. RESULTS: We discovered multiple mosaic-activating variants in 4 genes of the RAS/MAPK pathway, KRAS, NRAS, BRAF, and MAP2K1, a pathway commonly activated in cancer and responsible for the germline RAS-opathies. These variants were more frequent in high-flow than low-flow VMs. In vitro characterization and 2 transgenic zebrafish AVM models that recapitulated the human phenotype validated the pathogenesis of the mutant alleles. Importantly, treatment of AVM-BRAF mutant zebrafish with the BRAF inhibitor vemurafinib restored blood flow in AVM. CONCLUSION: Our findings uncover a major cause of sporadic VMs of different clinical types and thereby offer the potential of personalized medical treatment by repurposing existing licensed cancer therapies. FUNDING: This work was funded or supported by grants from the AVM Butterfly Charity, the Wellcome Trust (UK), the Medical Research Council (UK), the UK National Institute for Health Research, the L'Oreal-Melanoma Research Alliance, the European Research Council, and the National Human Genome Research Institute (US)

    Measurement of the top quark mass using the matrix element technique in dilepton final states

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    We present a measurement of the top quark mass in pp¯ collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7  fb−1. The matrix element technique is applied to tt¯ events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton+jets final state of tt¯ decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain a top quark mass of mt=173.93±1.84  GeV
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