720 research outputs found

    Musculoskeletal impairment survey in Rwanda: Design of survey tool, survey methodology, and results of the pilot study (a cross sectional survey)

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    BACKGROUND: Musculoskeletal impairment (MSI) is an important cause of morbidity and mortality worldwide, especially in developing countries. Prevalence studies for MSI in the developing world have used varying methodologies and are seldom directly comparable. This study aimed to develop a new tool to screen for and diagnose MSI and to pilot test the methodology for a national survey in Rwanda. METHODS: A 7 question screening tool to identify cases of MSI was developed through literature review and discussions with healthcare professionals. To validate the tool, trained rehabilitation technicians screened 93 previously identified gold standard 'cases' and 86 'non cases'. Sensitivity, specificity and positive predictive value were calculated. A standardised examination protocol was developed to determine the aetiology and diagnosis of MSI for those who fail the screening test. For the national survey in Rwanda, multistage cluster random sampling, with probability proportional to size procedures will be used for selection of a cross-sectional, nationally representative sample of the population. Households to be surveyed will be chosen through compact segment sampling and all individuals within chosen households will be screened. A pilot survey of 680 individuals was conducted using the protocol. RESULTS: The screening tool demonstrated 99% sensitivity and 97% specificity for MSI, and a positive predictive value of 98%. During the pilot study 468 out of 680 eligible subjects (69%) were screened. 45 diagnoses were identified in 38 persons who were cases of MSI. The subjects were grouped into categories based on diagnostic subgroups of congenital (1), traumatic (17), infective (2) neurological (6) and other acquired(19). They were also separated into mild (42.1%), moderate (42.1%) and severe (15.8%) cases, using an operational definition derived from the World Health Organisation's International Classification of Functioning, Disability and Health. CONCLUSION: The screening tool had good sensitivity and specificity and was appropriate for use in a national survey. The pilot study showed that the survey protocol was appropriate for measuring the prevalence of MSI in Rwanda. This survey is an important step to building a sound epidemiological understanding of MSI, to enable appropriate health service planning

    ANGLOR: A Composite Machine-Learning Algorithm for Protein Backbone Torsion Angle Prediction

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    We developed a composite machine-learning based algorithm, called ANGLOR, to predict real-value protein backbone torsion angles from amino acid sequences. The input features of ANGLOR include sequence profiles, predicted secondary structure and solvent accessibility. In a large-scale benchmarking test, the mean absolute error (MAE) of the phi/psi prediction is 28°/46°, which is ∼10% lower than that generated by software in literature. The prediction is statistically different from a random predictor (or a purely secondary-structure-based predictor) with p-value <1.0×10−300 (or <1.0×10−148) by Wilcoxon signed rank test. For some residues (ILE, LEU, PRO and VAL) and especially the residues in helix and buried regions, the MAE of phi angles is much smaller (10–20°) than that in other environments. Thus, although the average accuracy of the ANGLOR prediction is still low, the portion of the accurately predicted dihedral angles may be useful in assisting protein fold recognition and ab initio 3D structure modeling

    Matrix Rigidity Induces Osteolytic Gene Expression of Metastatic Breast Cancer Cells

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    Nearly 70% of breast cancer patients with advanced disease will develop bone metastases. Once established in bone, tumor cells produce factors that cause changes in normal bone remodeling, such as parathyroid hormone-related protein (PTHrP). While enhanced expression of PTHrP is known to stimulate osteoclasts to resorb bone, the environmental factors driving tumor cells to express PTHrP in the early stages of development of metastatic bone disease are unknown. In this study, we have shown that tumor cells known to metastasize to bone respond to 2D substrates with rigidities comparable to that of the bone microenvironment by increasing expression and production of PTHrP. The cellular response is regulated by Rho-dependent actomyosin contractility mediated by TGF-ß signaling. Inhibition of Rho-associated kinase (ROCK) using both pharmacological and genetic approaches decreased PTHrP expression. Furthermore, cells expressing a dominant negative form of the TGF-ß receptor did not respond to substrate rigidity, and inhibition of ROCK decreased PTHrP expression induced by exogenous TGF-ß. These observations suggest a role for the differential rigidity of the mineralized bone microenvironment in early stages of tumor-induced osteolysis, which is especially important in metastatic cancer since many cancers (such as those of the breast and lung) preferentially metastasize to bone

    Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at √s = 7 TeV with the ATLAS detector

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    This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of √s = 7 TeV;{\rm Te}{\rm V}andcorrespondtoanintegratedluminosityof and correspond to an integrated luminosity of 4.6\;{\rm f}{{{\rm b}}^{-1}}.ThemeasurementisperformedbyreconstructingtheboostedWorZbosonsinsinglejets.ThereconstructedjetmassisusedtoidentifytheWandZbosons,andajetsubstructuremethodbasedonenergyclusterinformationinthejetcentreofmassframeisusedtosuppressthelargemultijetbackground.ThecrosssectionforeventswithahadronicallydecayingWorZboson,withtransversemomentum. The measurement is performed by reconstructing the boosted W or Z bosons in single jets. The reconstructed jet mass is used to identify the W and Z bosons, and a jet substructure method based on energy cluster information in the jet centre-of-mass frame is used to suppress the large multi-jet background. The cross-section for events with a hadronically decaying W or Z boson, with transverse momentum {{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}andpseudorapidity and pseudorapidity |\eta |\lt 1.9,ismeasuredtobe, is measured to be {{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques

    Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

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    The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

    Search for pair-produced long-lived neutral particles decaying to jets in the ATLAS hadronic calorimeter in ppcollisions at √s=8TeV

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    The ATLAS detector at the Large Hadron Collider at CERN is used to search for the decay of a scalar boson to a pair of long-lived particles, neutral under the Standard Model gauge group, in 20.3fb−1of data collected in proton–proton collisions at √s=8TeV. This search is sensitive to long-lived particles that decay to Standard Model particles producing jets at the outer edge of the ATLAS electromagnetic calorimeter or inside the hadronic calorimeter. No significant excess of events is observed. Limits are reported on the product of the scalar boson production cross section times branching ratio into long-lived neutral particles as a function of the proper lifetime of the particles. Limits are reported for boson masses from 100 GeVto 900 GeV, and a long-lived neutral particle mass from 10 GeVto 150 GeV

    Beckman Access versus the Bayer ACS:180 and the Abbott AxSYM cardiac Troponin-I real-time immunoassays: an observational prospective study

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    BACKGROUND: Reliability of cardiac troponin-I assays under real-time conditions has not been previously well studied. Most large published cTnI trials have utilized protocols which required the freezing of serum (or plasma) for delayed batch cTnI analysis. We sought to correlate the presence of the acute ischemic coronary syndrome (AICS) to troponin-I values obtained in real-time by three random-mode analyzer immunoassay systems: the Beckman ACCESS (BA), the Bayer ACS:180 (CC) and the Abbott AxSYM (AX). METHODS: This was an observational prospective study at a university tertiary referral center. Serum from a convenience sampling of telemetry patients was analyzed in real-time for troponin-I by either the BA-CC (Arm-1) or BA-AX (Arm-2) assay pairs. Presence of the AICS was determined retrospectively and then correlated with troponin-I results. RESULTS: 100 patients were enrolled in Arm-1 (38 with AICS) and 94 in Arm-2 (48 with AICS). The BA system produced 51% false positives in Arm-1, 44% in Arm-2, with negative predictive values of 92% and 100% respectively. In Arm-1, the BA and the CC assays had sensitivities of 97% and 63% and specificities of 18% and 87%. In Arm-2, the BA and the AX assays had sensitivities of 100% and 83% and specificities of 11% and 78%. CONCLUSIONS: In real-time analysis, the performance of the AxSYM and ACS:180 assay systems produced more accurate troponin-I results than the ACCESS system

    Hamartomas, teratomas and teratocarcinosarcomas of the head and neck: Report of 3 new cases with clinico-pathologic correlation, cytogenetic analysis, and review of the literature

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    <p>Abstract</p> <p>Background</p> <p>Germ-cell tumors (GCT) are a histologically and biologically diverse group of neoplasms which primarily occur in the gonads but also develop at different extragonadal sites in the midline of the body. The head and neck region including the upper respiratory tract is a very rare location for such tumors in both children and adults, which can cause diagnostic and therapeutic difficulties.</p> <p>Methods</p> <p>We describe here two new cases of multilineage tumors including sinonasal teratocarcinosarcoma [SNTCS], and congenital oronasopharyngeal teratoma (epignathus) and compare their features with those of a new case of a rare salivary gland anlage tumor [SGAT], an entity for which the pathogenesis is unclear (i.e. hamartoma versus neoplasm). We correlate their presenting clinico-pathological features and compare histologic and cytogenetic features in an attempt to elucidate their pathogenesis and biologic potentials.</p> <p>Results and discussion</p> <p>Cytogenetic analysis revealed chromosomal abnormalities only in the case of SNTCS that showed trisomy 12 and 1p deletion. Both cytogenetic abnormalities are characteristically present in malignant germ cell tumors providing for the first time evidence that this rare tumor type indeed might represent a variant of a germ cell neoplasm. The SGAT and epignathus carried no such cytogenetic abnormalities, in keeping with their limited and benign biologic potential.</p> <p>Conclusion</p> <p>The comparison of these three cases should serve to emphasize the diversity of multilineage tumors (hamartomas and GCT) of the upper respiratory tract in regards to their biology, age of presentation and clinical outcomes. Malignant tumors of germ cell origins are more likely to affect adults with insidious symptom development, while benign tumors can nevertheless cause dramatic clinical symptoms which, under certain circumstances, can be fatal.</p

    Expression of different survivin variants in gastric carcinomas: first clues to a role of survivin-2B in tumour progression

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    Survivin is a novel member of the inhibitor of apoptosis family and determines the susceptibility of tumour cells to pro-apoptotic stimuli. Recently, we identified two novel alternative splice variants of survivin, differing in their anti-apoptotic properties: whereas the anti-apoptotic potential of survivin-ΔEx3 is preserved, survivin-2B has lost its anti-apoptotic potential and may act as a naturally occurring antagonist of survivin. Because the in vivo expression of these alternative splice variants has not been explored so far, we analysed gastric carcinomas of different histological subtypes, grades and stages. Since no antibodies are currently available to determine the novel splice variants, quantitative reverse transcriptase polymerase chain reaction was performed, using RNA samples obtained from 30 different gastric carcinomas. Polymerase chain reactions products were quantified by densitometric evaluation. We found that all gastric carcinomas, irrespective of their histological types, grades or stages, express survivin-ΔEx3, survivin-2B and survivin, the latter being the dominant transcript. Comparing the disease stages I+II with III+IV, expression of survivin and survivin-ΔEx3 remained unchanged. In contrast, a significant (P=0.033) stage-dependent decrease in the expression of survivin-2B became evident. Our study demonstrates for the first time the expression of alternative splice variants in gastric carcinomas and provides a first clue to a role of survivin-2B in tumour progression
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