1,851 research outputs found

    Latex allergy: ‘Plight, rights and fights’

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    No Abstract

    Year-round housedust mite levels on the highveld

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    Objective. To determine the levels of the allergen DerPl, attnbutable to the house-dust mite (HDM) Dermatophagoides pteronyssinus.Design. A four-season study conducted during 1994/95, sampling mattresses and carpets in the main bedrooms of suburban homes.Setting. Thirty randomly selected homes in the Edenvale area, occupied by both black and white families living under similar socio-economic conditions in comparable environments.Results, All homes tested positive for the allergen, and in 20% HDM levels exceeded levels recognised as 'safe' in terms of respiratory allergy, i.e. 2 ug/g of dust. Once mites were established in a home, they remained for months thereafter. The considerable seasonal variation recorded in HDM levels could not readily be explained.Conclusion. The HDM is extremely sensitive to minimal variations in microclimate. Its year-round presence is of concern on the Highveld. Infestation levels below 2 JIg/g of dust, until recently considered the critical point for sensitisation, may be significant triggers of symptoms

    The allergy clinic: 50 years

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    No Abstract. South African Medical Journal Vol. 96(9) (Part 2) 2006: 902-90

    Latex allergy at Groote Schuur hospital prevalence, clinical features and outcome

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    Background. The incidence of latex allergy is increasing worldwide but there is very little information available on the clinical outcome for affected individuals.Objective. To determine the prevalence of latex allergy at Groote Schuur Hospital, a large teaching hospital in Cape Town, and to study the outcome for affected individuals.Method. Using a questionnaire, we screened 2 316 hospital workers for the presence of work-related symptoms. Workers who were symptomatic had Immunocap RAST (CAP RAST) or skin-prick tests to confirm latex sensitivity. Latexavoidance measures were implemented in positive subjects. One hundred symptomatic, sensitised individuals were followed up 3 months after intervention to assess their clinical status. A further cohort of 25 individuals with ongoing nasal symptoms were studied in detail.Results. Latex sensitisation was confirmed in 182 of 717 symptomatic workers (25.3%). SenSitised symptomatic workers were significantly more likely to have had a previous history of urticaria (P = < 0.001), oral allergy syndrome (P = < 0.001), or allergic conjunctivitis (P = 0.001), but not hay fever, perennial rhinitis, eczema or insect allergies. Latex sensitisation occurred among all classes of health care workers. Ocular and cutaneous symptoms were significantly associated with positive latex sensitisation (P = < 0.001). After latex intervention, ocular symptoms (P = < 0.001), skin rashes (P = < 0.001) and wheezing (P = 0.001) reduced significantly. Nasal symptoms did not improve. Undiagnosed and untreated underlying allergies to common aero-allergens were present in the majority of latexsensitised patients with ongoing nasal symptomatology.Conclusion. The prevalence of symptomatic sensitisation to latex allergy at Groote Schuur Hospital is between 9.2 and 11.2%. Ocular and cutaneous symptoms are the most prevalent in sensitised workers, and unlike nasal symptoms are significantly reduced when latex-avoidance measures are introduced. Ongoing nasal symptoms after intervention is instituted are probably due to other allergic sensitivities in latex-sensitised health care workers

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    PIP5KIβ Selectively Modulates Apical Endocytosis in Polarized Renal Epithelial Cells

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    Localized synthesis of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] at clathrin coated pits (CCPs) is crucial for the recruitment of adaptors and other components of the internalization machinery, as well as for regulating actin dynamics during endocytosis. PtdIns(4,5)P2 is synthesized from phosphatidylinositol 4-phosphate by any of three phosphatidylinositol 5-kinase type I (PIP5KI) isoforms (α, β or γ). PIP5KIβ localizes almost exclusively to the apical surface in polarized mouse cortical collecting duct cells, whereas the other isoforms have a less polarized membrane distribution. We therefore investigated the role of PIP5KI isoforms in endocytosis at the apical and basolateral domains. Endocytosis at the apical surface is known to occur more slowly than at the basolateral surface. Apical endocytosis was selectively stimulated by overexpression of PIP5KIβ whereas the other isoforms had no effect on either apical or basolateral internalization. We found no difference in the affinity for PtdIns(4,5)P2-containing liposomes of the PtdIns(4,5)P2 binding domains of epsin and Dab2, consistent with a generic effect of elevated PtdIns(4,5)P2 on apical endocytosis. Additionally, using apical total internal reflection fluorescence imaging and electron microscopy we found that cells overexpressing PIP5KIβ have fewer apical CCPs but more internalized coated structures than control cells, consistent with enhanced maturation of apical CCPs. Together, our results suggest that synthesis of PtdIns(4,5)P2 mediated by PIP5KIβ is rate limiting for apical but not basolateral endocytosis in polarized kidney cells. PtdIns(4,5)P2 may be required to overcome specific structural constraints that limit the efficiency of apical endocytosis. © 2013 Szalinski et al

    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 new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT
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