instruction:
In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
question:
Context: Mechanical support leads to an increased risk of both bleeding and thrombotic events, but little is known about the risk of device support in patients with a baseline predisposition to these events. The aim of this study was to examine outcomes among patients with baseline hematologic conditions who underwent continuous-flow LVAD implantation (CF-LVAD).', 'We retrospectively reviewed records of 286 patients who underwent CF-LVAD implantation at the Columbia University Medical Center between April 2008 and December 2013. Patients diagnosed with the following hematologic conditions were enrolled: idiopathic thrombocytopenic purpura (ITP); Factor V Leiden; elevated Factor VIII; heparin-induced thrombocytopenia (HIT); or undefined hypercoagulable state.', 'Of the 286 CF-LVAD patients implanted during the study period, 12 were considered to have a significant hematologic condition predisposing them to either bleeding or thrombotic events. The study included 5 patients with ITP, 1 with Factor V Leiden, 1 with elevated Factor VIII, 2 with HIT and 3 patients with undefined hypercoagulable state. Patients were supported for a total of 168.46 months, with a median of 10.76 months (IQR 4.78 to 21.36 months). There was a high frequency of thrombotic (0.57 event per patient-year), neurologic (0.36 event per patient-year) and bleeding (0.64 event per patient-year). Actuarial survival rates at 6 and 12 months were 81.8%, but fell to 49% at 2 years.\Question: Do prior hematologic conditions carry a high morbidity and mortality in patients supported with continuous-flow left ventricular assist devices?
answer:
Patients with a history of prior hematologic conditions are at high risk for bleeding, thrombotic and neurologic events during device support, leading to early mortality. This case series questions the benefit of CF-LVAD in these patients and the appropriate management with regard to anti-coagulation. Further studies on the outcomes of these patients are warranted.


question:
Context: Transport across the blood-brain barrier (BBB) is an important mediator of beta-amyloid (Aβ) accumulation in the brain and a contributing factor in the pathogenesis of Alzheimer's disease (AD). One of the receptors responsible for the transport of Aβ in the BBB is the low density lipoprotein receptor-related protein 1 (LRP1). LRP1 is susceptible to proteolytic shedding at the cell surface, which prevents endocytic transport of ligands. Previously, we reported a strong inverse correlation between LRP1 shedding in the brain and Aβ transit across the BBB. Several proteases contribute to the ectodomain shedding of LRP1 including the α-secretase, a desintegrin and metalloproteinase domain containing protein 10 (ADAM10).", 'The role of ADAM10 in the shedding of LRP1 and Aβ BBB clearance was assessed through pharmacological inhibition of ADAM10 in an in vitro model of the BBB and through the use of ADAM10 endothelial specific knock-out mice. In addition, an acute treatment paradigm with an ADAM10 inhibitor was also tested in an AD mouse model to assess the effect of ADAM10 inhibition on LRP1 shedding and Aβbrain accumulation.', 'In the current studies, inhibition of ADAM10 reduced LRP1 shedding in brain endothelial cultures and increased Aβ42 transit across an in vitro model of the BBB. Similarly, transgenic ADAM10 endothelial knockout mice displayed lower LRP1 shedding in the brain and significantly enhanced Aβ clearance across the BBB compared to wild-type animals. Acute treatment with the ADAM10-selective inhibitor GI254023X in an AD mouse model substantially reduced brain LRP1 shedding and increased Aβ40 levels in the plasma, indicating enhanced Aβ transit from the brain to the periphery. Furthermore, both soluble and insoluble Aβ40 and Aβ42 brain levels were decreased following GI254023X treatment, but these effects lacked statistical significance.\Question: Does inhibition of ADAM10 promote the clearance of Aβ across the BBB by reducing LRP1 ectodomain shedding?
answer:
These studies demonstrate a role for ADAM10 in the ectodomain shedding of LRP1 in the brain and the clearance of Aβ across the BBB, which may provide a novel strategy for attenuating Aβ accumulation in the AD brain.


question:
Context: The majority of studies assessing executive function in attention deficit disorder (ADD) have shown deficits in attentional set shifting using either the Wisconsin card sorting task or the intra-dimensional/extra-dimensional set-shifting task (ID/ED). Damage to the prefrontal cortex in humans, primates, and rodents impairs extra-dimensional (ED) shifts. Noradrenergic depletion of the medial prefrontal cortex in rats is sufficient to impair attentional set shifting. Atomoxetine, a selective norepinephrine (NE) re-uptake inhibitor, is hypothesized to produce beneficial effects in patient with ADD by augmenting NE release in prefrontal cortex.', 'We assessed the effects of systemic administration of atomoxetine (0.0, 0.1, 0.3, and 0.9 mg/kg/ml) in normal and noradrenergically lesioned (NE-LX) rats on attentional-set shifts. We replicated findings showing NE-LX rats are selectively impaired on the ED shifts but not reversals or other discriminations.', 'Atomoxetine remediated the attentional set-shifting impairments in NE-LX rats but impaired ED performance of non-lesioned rats.\Question: Does atomoxetine reverse attentional deficits produced by noradrenergic deafferentation of medial prefrontal cortex?
answer:

Though atomoxetine is neurochemically selective, it is not wholly specific at doses >0.3 mg/kg. All doses of the drug were similar in their efficacy in reversing the ED deficit, but the effectiveness of the 0.1 mg/kg dose supports the hypothesis that increases in prefrontal NE alone are sufficient to improve attention in NE-LX rats. Moreover, the detrimental effects of the drug in non-lesioned rats support the hypothesis that optimal levels of NE in prefrontal cortex are critical to attentional set shifting with both supra- and sub-optimal levels producing attentional impairments.