TASK DEFINITION: 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.
PROBLEM: 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?

SOLUTION: 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.

PROBLEM: Context: The CARD14 gene encodes a protein that enhances nuclear factor (NF)-B activation and the upregulation of proinflammatory pathway genes. CARD14 is upregulated in psoriatic vs. normal skin, and rare and common CARD14 variants have been associated with the risk of developing psoriasis. Our hypothesis was that CARD14 variants could also influence the response to antitumour necrosis factor (anti-TNF) therapies among patients with psoriasis.', 'To determine whether CARD14 gene variants were linked to a significant positive anti-TNF response in patients with psoriasis.', 'DNA from 116 patients with psoriasis was subjected to next-generation sequencing of the CARD14 gene. All of the patients were nonresponders or had contraindications to conventional systemic treatments.', 'A reduction of at least 75% in Psoriasis Area and Severity Index (PASI 75) at week 24 was considered a positive response to treatment. In total 116 patients (79 responders and 37 nonresponders) were next-generation sequenced, and we identified five nucleotide variants that would result in missense amino acid changes. These variants were determined in all of the patients, and allele and genotype frequencies were compared between the two groups. We found a significantly higher frequency of rs11652075 CC (p.Arg820Trp) among the group with a positive response (P = 0.01, odds ratio 3.71, 95% confidence interval 1.30-10.51). Furthermore, among responders, six patients were heterozygous carriers of the rare p.Glu422Lys variant, and two patients were heterozygous for p.Arg682Trp (P = 0.04).\Question: Do common and rare CARD14 gene variants affect the antitumour necrosis factor response among patients with psoriasis?

SOLUTION: The common CARD14 p.Arg820Trp variant might have a significant effect on the response to anti-TNF therapies among patients with psoriasis. In addition, rare CARD14 missense variants could also predispose to a better response.

PROBLEM: Context: The consumption of an agrarian diet is associated with a reduced risk for many diseases associated with a 'Westernised' lifestyle. Studies suggest that diet affects the gut microbiota, which subsequently influences the metabolome, thereby connecting diet, microbiota and health. However, the degree to which diet influences the composition of the gut microbiota is controversial. Murine models and studies comparing the gut microbiota in humans residing in agrarian versus Western societies suggest that the influence is large. To separate global environmental influences from dietary influences, we characterised the gut microbiota and the host metabolome of individuals consuming an agrarian diet in Western society.", 'Using 16S rRNA-tagged sequencing as well as plasma and urinary metabolomic platforms, we compared measures of dietary intake, gut microbiota composition and the plasma metabolome between healthy human vegans and omnivores, sampled in an urban USA environment. Plasma metabolome of vegans differed markedly from omnivores but the gut microbiota was surprisingly similar. Unlike prior studies of individuals living in agrarian societies, higher consumption of fermentable substrate in vegans was not associated with higher levels of faecal short chain fatty acids, a finding confirmed in a 10-day controlled feeding experiment. Similarly, the proportion of vegans capable of producing equol, a soy-based gut microbiota metabolite, was less than that was reported in Asian societies despite the high consumption of soy-based products.\Question: Do comparative metabolomics in vegans and omnivores reveal constraints on diet-dependent gut microbiota metabolite production?

SOLUTION:
Evidently, residence in globally distinct societies helps determine the composition of the gut microbiota that, in turn, influences the production of diet-dependent gut microbial metabolites.