318 research outputs found

    An observational study of patient characteristics associated with the mode of admission to acute stroke services in North East, England

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    Objective Effective provision of urgent stroke care relies upon admission to hospital by emergency ambulance and may involve pre-hospital redirection. The proportion and characteristics of patients who do not arrive by emergency ambulance and their impact on service efficiency is unclear. To assist in the planning of regional stroke services we examined the volume, characteristics and prognosis of patients according to the mode of presentation to local services. Study design and setting A prospective regional database of consecutive acute stroke admissions was conducted in North East, England between 01/09/10-30/09/11. Case ascertainment and transport mode were checked against hospital coding and ambulance dispatch databases. Results Twelve acute stroke units contributed data for a mean of 10.7 months. 2792/3131 (89%) patients received a diagnosis of stroke within 24 hours of admission: 2002 arrivals by emergency ambulance; 538 by private transport or non-emergency ambulance; 252 unknown mode. Emergency ambulance patients were older (76 vs 69 years), more likely to be from institutional care (10% vs 1%) and experiencing total anterior circulation symptoms (27% vs 6%). Thrombolysis treatment was commoner following emergency admission (11% vs 4%). However patients attending without emergency ambulance had lower inpatient mortality (2% vs 18%), a lower rate of institutionalisation (1% vs 6%) and less need for daily carers (7% vs 16%). 149/155 (96%) of highly dependent patients were admitted by emergency ambulance, but none received thrombolysis. Conclusion Presentations of new stroke without emergency ambulance involvement were not unusual but were associated with a better outcome due to younger age, milder neurological impairment and lower levels of pre-stroke dependency. Most patients with a high level of pre-stroke dependency arrived by emergency ambulance but did not receive thrombolysis. It is important to be aware of easily identifiable demographic groups that differ in their potential to gain from different service configurations

    Theory of Multidimensional Solitons

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    We review a number of topics germane to higher-dimensional solitons in Bose-Einstein condensates. For dark solitons, we discuss dark band and planar solitons; ring dark solitons and spherical shell solitons; solitary waves in restricted geometries; vortex rings and rarefaction pulses; and multi-component Bose-Einstein condensates. For bright solitons, we discuss instability, stability, and metastability; bright soliton engineering, including pulsed atom lasers; solitons in a thermal bath; soliton-soliton interactions; and bright ring solitons and quantum vortices. A thorough reference list is included.Comment: review paper, to appear as Chapter 5a in "Emergent Nonlinear Phenomena in Bose-Einstein Condensates: Theory and Experiment," edited by P. G. Kevrekidis, D. J. Frantzeskakis, and R. Carretero-Gonzalez (Springer-Verlag

    Management of Massive Arterial Hemorrhage After Pancreatobiliary Surgery: Does Embolotherapy Contribute to Successful Outcome?

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    Massive arterial hemorrhage is, although unusual, a life-threatening complication of major pancreatobiliary surgery. Records of 351 patients who underwent major surgery for malignant pancreatobiliary disease were reviewed in this series. Thirteen patients (3.7%) experienced massive hemorrhage after surgery. Complete hemostasis by transcatheter arterial embolization (TAE) or re-laparotomy was achieved in five patients and one patient, respectively. However, 7 of 13 cases ended in fatality, which is a 54% mortality rate. Among six survivors, one underwent selective TAE for a pseudoaneurysm of the right hepatic artery (RHA). Three patients underwent TAE proximal to the proper hepatic artery (PHA): hepatic inflow was maintained by successful TAE of the gastroduodenal artery in two and via a well-developed subphrenic artery in one. One patient had TAE of the celiac axis for a pseudoaneurysm of the splenic artery (SPA), and hepatic inflow was maintained by the arcades around the pancreatic head. One patient who experienced a pseudoaneurysm of the RHA after left hemihepatectomy successfully underwent re-laparotomy, ligation of RHA, and creation of an ileocolic arterioportal shunt. In contrast, four of seven patients with fatal outcomes experienced hepatic infarction following TAE proximal to the PHA or injury of the common hepatic artery during angiography. One patient who underwent a major hepatectomy for hilar bile duct cancer had a recurrent hemorrhage after TAE of the gastroduodenal artery and experienced hepatic failure. In the two patients with a pseudoaneurysm of the SPA or the superior mesenteric artery, an emergency re-laparotomy was required to obtain hemostasis because of worsening clinical status. Selective TAE distal to PHA or in the SPA is usually successful. TAE proximal to PHA must be restricted to cases where collateral hepatic blood flow exists. Otherwise or for a pseudoaneurysm of the superior mesenteric artery, endovascular stenting, temporary creation of an ileocolic arterioportal shunt, or vascular reconstruction by re-laparotomy is an alternative

    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 (Ξ£ETPb) summed over 3.1<Ξ·<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) β€œnear-side” (Ξ”Ο•βˆΌ0) correlation that grows rapidly with increasing Ξ£ETPb. A long-range β€œaway-side” (Ξ”Ο•βˆΌΟ€) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small Ξ£ETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and Ξ£ETPb dependence. The resultant Δϕ correlation is approximately symmetric about Ο€/2, and is consistent with a dominant cos⁑2Δϕ modulation for all Ξ£ETPb ranges and particle pT

    Endoplasmic Reticulum Stress-Induced JNK Activation Is a Critical Event Leading to Mitochondria-Mediated Cell Death Caused by Ξ²-Lapachone Treatment

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    Ξ²-lapachone (Ξ²-lap) is a bioreductive agent that is activated by the two-electron reductase NAD(P)H quinone oxidoreductase 1 (NQO1). Although Ξ²-lap has been reported to induce apoptosis in various cancer types in an NQO1-dependent manner, the signaling pathways by which Ξ²-lap causes apoptosis are poorly understood.Ξ²-lap-induced apoptosis and related molecular signaling pathways in NQO1-negative and NQO1-overexpressing MDA-MB-231 cells were investigated. Pharmacological inhibitors or siRNAs against factors involved in Ξ²-lap-induced apoptosis were used to clarify the roles played by such factors in Ξ²-lap-activated apoptotic signaling pathways. Ξ²-lap leads to clonogenic cell death and apoptosis in an NQO1- dependent manner. Treatment of NQO1-overexpressing MDA-MB-231 cells with Ξ²-lap causes rapid disruption of mitochondrial membrane potential, nuclear translocation of AIF and Endo G from mitochondria, and subsequent caspase-independent apoptotic cell death. siRNAs targeting AIF and Endo G effectively attenuate Ξ²-lap-induced clonogenic and apoptotic cell death. Moreover, Ξ²-lap induces cleavage of Bax, which accumulates in mitochondria, coinciding with the observed changes in mitochondria membrane potential. Pretreatment with Salubrinal (Sal), an endoplasmic reticulum (ER) stress inhibitor, efficiently attenuates JNK activation caused by Ξ²-lap, and subsequent mitochondria-mediated cell death. In addition, Ξ²-lap-induced generation and mitochondrial translocation of cleaved Bax are efficiently blocked by JNK inhibition.Our results indicate that Ξ²-lap triggers induction of endoplasmic reticulum (ER) stress, thereby leading to JNK activation and mitochondria-mediated apoptosis. The signaling pathways that we revealed in this study may significantly contribute to an improvement of NQO1-directed tumor therapies

    Prolonged Application of High Fluid Shear to Chondrocytes Recapitulates Gene Expression Profiles Associated with Osteoarthritis

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    BACKGROUND: Excessive mechanical loading of articular cartilage producing hydrostatic stress, tensile strain and fluid flow leads to irreversible cartilage erosion and osteoarthritic (OA) disease. Since application of high fluid shear to chondrocytes recapitulates some of the earmarks of OA, we aimed to screen the gene expression profiles of shear-activated chondrocytes and assess potential similarities with OA chondrocytes. METHODOLOGY/PRINCIPAL FINDINGS: Using a cDNA microarray technology, we screened the differentially-regulated genes in human T/C-28a2 chondrocytes subjected to high fluid shear (20 dyn/cm(2)) for 48 h and 72 h relative to static controls. Confirmation of the expression patterns of select genes was obtained by qRT-PCR. Using significance analysis of microarrays with a 5% false discovery rate, 71 and 60 non-redundant transcripts were identified to be β‰₯2-fold up-regulated and ≀0.6-fold down-regulated, respectively, in sheared chondrocytes. Published data sets indicate that 42 of these genes, which are related to extracellular matrix/degradation, cell proliferation/differentiation, inflammation and cell survival/death, are differentially-regulated in OA chondrocytes. In view of the pivotal role of cyclooxygenase-2 (COX-2) in the pathogenesis and/or progression of OA in vivo and regulation of shear-induced inflammation and apoptosis in vitro, we identified a collection of genes that are either up- or down-regulated by shear-induced COX-2. COX-2 and L-prostaglandin D synthase (L-PGDS) induce reactive oxygen species production, and negatively regulate genes of the histone and cell cycle families, which may play a critical role in chondrocyte death. CONCLUSIONS/SIGNIFICANCE: Prolonged application of high fluid shear stress to chondrocytes recapitulates gene expression profiles associated with osteoarthritis. Our data suggest a potential link between exposure of chondrocytes/cartilage to abnormal mechanical loading and the pathogenesis/progression of OA
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