Role of antiplatelet therapy in cardiovascular disease II: Ischemic stroke.

The etiology of cerebrovascular disease is heterogeneous, with the majority of strokes being of ischemic origin. Transient ischemic attack is now considered to be an important precursor and long-term risk factor for ischemic stroke. Given the lack of acute therapies for ischemic stroke, current treatments focus on secondary prevention through risk-factor management, pharmacotherapy and interventional approaches. As illustrated in this paper, antiplatelet agents (e.g. clopidogrel, aspirin, dipyridamole) are the cornerstone of therapy for prevention of recurrent ischemic stroke

Multiple sulphur and lead sources recorded in hydrothermal exhalites associated with the Lemarchant volcanogenic massive sulphide deposit, central Newfoundland, Canada

This research is funded by the Canadian Mining Research Organization (CAMIRO) and an NSERC CRD grant. Research is also funded by the NSERC-Altius Industrial Research Chair in Mineral Deposits, funded by NSERC, Altius Resources Inc. and the Development Corporation of Newfoundland and Labrador.Metalliferous sedimentary rocks (mudstones, exhalites) associated with the Cambrian precious metal-bearing Lemarchant Zn-Pb-Cu-Au-Ag-Ba volcanogenic massive sulphide (VMS) deposit, Tally Pond volcanic belt, precipitated both before and after VMS mineralization. Sulphur and Pb isotopic studies of sulphides within the Lemarchant exhalites provide insight into the sources of S and Pb in the exhalites as a function of paragenesis and evolution of the deposit and subsequent post-depositional modification. In situ S isotope microanalyses of polymetallic sulphides (euhedral and framboidal pyrite, anhedral chalcopyrite, pyrrhotite, galena and euhedral arsenopyrite) by secondary ion mass spectrometry (SIMS) yielded δ34S values ranging from −38.8 to +14.4 ‰, with an average of ∼ −12.8 ‰. The δ34S systematics indicate sulphur was predominantly biogenically derived via microbial/biogenic sulphate reduction of seawater sulphate, microbial sulphide oxidation and microbial disproportionation of intermediate S compounds. These biogenic processes are coupled and occur within layers of microbial mats consisting of different bacterial/archaeal species, i.e., sulphate reducers, sulphide oxidizers and those that disproportionate sulphur compounds. Inorganic processes or sources (i.e., thermochemical sulphate reduction of seawater sulphate, leached or direct igneous sulphur) also contributed to the S budget in the hydrothermal exhalites and are more pronounced in exhalites that are immediately associated with massive sulphides. Galena Pb isotopic compositions by SIMS microanalysis suggest derivation of Pb from underlying crustal basement (felsic volcanic rocks of Sandy Brook Group), whereas less radiogenic Pb derived from juvenile sources leached from mafic volcanic rocks of the Sandy Brook Group and/or Tally Pond group. This requires that the hydrothermal fluids interacted with juvenile and evolved crust during hydrothermal circulation, which is consistent with the existing tectonic model that suggests a formation of the Tally Pond belt volcanic rocks and associated VMS deposits in a rifted arc environment upon crustal basement of the Ediacaran age Sandy Brook Group and Crippleback Intrusive Suite. Combined S and Pb isotope data illustrate that sulphides within the deposit that are proximal to the vent contain a higher proportion of sulphur derived from thermochemical sulphate reduction (TSR), because hydrothermal fluids are enriched in H2S derived from TSR. They also have lower radiogenic Pb contributions, than sulphides occurring distal from mineralization. Hence, the TSR S and non-radiogenic Pb composition may provide an exploration vector in exhalites associated with similar VMS environments.PostprintPeer reviewe

Law Enforcement Preferences for PTSD Treatment and Crisis Management Alternatives

Evidence-based treatments (EBT) for posttraumatic stress disorder (PTSD) remain underutilized. Analog research, however, indicates that patients may be more amenable to receiving EBT for PTSD than utilization rates suggest. This study sought to extend previous studies by investigating PTSD treatment preferences among law enforcement individuals (i.e., active duty officers, cadets, criminal justice students). We asked 379 participants, with varying trauma histories, to read a police traumatic event and imagine they had developed PTSD. Participants rated the credibility of six treatment options which they might encounter in a treatment setting, and chose their most and least preferred treatments. Next, they evaluated a widely used debriefing intervention aimed at preventing PTSD. Almost 90% of participants chose exposure or cognitive processing therapy as their first or second most preferred treatment, and they rated these interventions as significantly more credible than the other 4 treatment options. The sample showed ambivalence regarding the perceived efficacy of debriefing but found the rationale credible. This study supports previous analog research indicating that patients may be more interested EBT than indicated by utilization rates, and suggests that law enforcement departments should consider offering EBT to officers who develop PTSD

Cell-selective proteomics for biological discovery

Cells alter the proteome to respond to environmental and developmental cues. Global analysis of proteomic responses is of limited value in heterogeneous environments, where there is no ‘average’ cell. Advances in sequencing, protein labeling, mass spectrometry, and data analysis have fueled recent progress in the investigation of specific subpopulations of cells in complex systems. Here we highlight recently developed chemical tools that enable cell-selective proteomic analysis of complex biological systems, from bacterial pathogens to whole animals

The Case of AB Aurigae's Disk in Polarized Light: Is There Truly a Gap?

Using the NICMOS coronagraph, we have obtained high-contrast 2.0 micron imaging polarimetry and 1.1 micron imaging of the circumstellar disk around AB Aurigae on angular scales of 0.3-3 arcsec (40-550 AU). Unlike previous observations, these data resolve the disk in both total and polarized intensity, allowing accurate measurement of the spatial variation of polarization fraction across the disk. Using these observations we investigate the apparent "gap" in the disk reported by Oppenheimer et al. 2008. In polarized intensity, the NICMOS data closely reproduces the morphology seen by Oppenheimer et al., yet in total intensity we find no evidence for a gap in either our 1.1 or 2.0 micron images. We find instead that region has lower polarization fraction, without a significant decrease in total scattered light, consistent with expectations for back-scattered light on the far side of an inclined disk. Radiative transfer models demonstrate this explanation fits the observations. Geometrical scattering effects are entirely sufficient to explain the observed morphology without any need to invoke a gap or protoplanet at that location.Comment: Accepted to ApJ Letter

Building Cohesion in Distributed Telemedicine Teams Findings from the Department of Veterans Affairs National Telestroke Program

Background: As telemedicine adoption increases, so does the importance of building cohesion among physicians in telemedicine teams. For example, in acute telestroke services, stroke specialists provide rapid virtual stroke assessment and treatment to patients at hospitals without stroke specialty care. In the National Telestroke Program (NTSP) of the U.S. Department of Veterans Affairs, a virtual (distributed) hub of stroke specialists throughout the country provides 24/7 consultations nationwide. We examined how these specialists adapted to distributed teamwork, and we identied cohesion-related factors inprogram development and support. Methods: We conducted a case study of the stroke specialists employed by the NTSP. Semi-structured, condential interviews with stroke specialists in the virtual hub were recorded and transcribed. We explored the extent to which these specialists had developed a sense of shared identity and teamcohesion, and we identied factors in this development. Using a qualitative approach with constant comparison methods, two researchers coded each interview transcript independently using a shared codebook. We used matrix displays to identify themes, with special attention to team cohesion, communication, trust, and satisfaction. Results: Of 13 specialists with at least 8 months of NTSP practice, 12 completed interviews; 7 had previously practiced in telestroke programs in other healthcare systems. Interviewees reported high levels of trust and team cohesion, sometimes even more with their virtual colleagues than with local colleagues. Factors facilitating perceived team cohesion included a weekly case conference call, a sense of transparency in discussing challenges, engagement in NTSP development tasks, and support from the NTSP leadership. Although lack of in-person contact was associated with lower cohesion, annual in-person NTSP meetings helped mitigate this issue. Despite technical challenges in establishing a new telehealth system within existing national infrastructure, providers reported high levels of satisfaction with the NTSP.Conclusion: A virtual telestroke hub can provide a sense of team cohesion among stroke specialists at a level comparable with a standard co-located practice. Engaging in transparent discussion of challenging cases, reviewing new clinical evidence, and contributing to program improvements may promotecohesion in distributed telemedicine teamsThis work was funded by the Veterans Health Administration (VHA) Office of Rural Health (016ORH), VHA Office of Specialty Care, VA Health Services Research and Development (HSR&D) Precision Monitoring Quality Enhancement Research Initiative (QUE 15-280). Funding sources had no role in study design, data collection, data analysis, data interpretation, or manuscript writing. The views expressed herein are those of the authors and do not necessarily reflect the views of the U.S. Department of Veterans Affairs

Utilization of Upper Endoscopy for Surveillance of Gastric Ulcers in the United States

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73657/1/j.1572-0241.2008.01945.x.pd