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: Ischemic postconditioning protects the reperfused heart from infarction, and this protection is dependent on the occupancy of adenosine receptors. We further explored the role of adenosine receptors in this salvage.', 'In situ rabbit hearts underwent 30 min of regional ischemia and 3 h of reperfusion, and postconditioning was effected with four cycles of 30-s reperfusion/30-s coronary artery occlusion at the end of ischemia.', "Postconditioning reduced infarct size from 40.2+/-3.4% of the risk zone in untreated hearts to 15.5+/-2.5%. Protection by postconditioning was blocked by either the non-selective adenosine receptor blocker 8-p-(sulfophenyl)theophylline or the A2b-selective antagonist MRS 1754, injected intravenously 5 min before reperfusion. The protein kinase C (PKC) antagonist chelerythrine also aborted postconditioning's salvage, indicating a PKC-dependent mechanism. Neither the A1-selective antagonist 8-cyclopentyl-1,3-dipropylxanthine nor the A2a-selective antagonist 8-(13-chlorostyryl)caffeine had an effect on protection. The non-selective but A2b-potent adenosine agonist 5'-(N-ethylcarboxamido)adenosine (NECA) infused from 5 min before to 1h after reperfusion mimicked postconditioning's effect on infarct size (17.2+/-2.7% infarction) and MRS 1754 blocked the NECA-induced cardioprotection, confirming that A2b activation was protective. The PKC activator phorbol 12-myristate 13-acetate delivered just before reperfusion also duplicated the protective effect of postconditioning (16.3+/-4.1% infarction), and co-administration of the PKC antagonist chelerythrine aborted PMA's protection, confirming that the protection was the result of PKC activation. NECA's protective effect was not affected by chelerythrine, but rather MRS 1754 blocked PMA's salutary effect (42.8+/-1.0% infarction), suggesting that the A2b receptor's effect is under control of PKC. Finally, wortmannin, a blocker of phosphatidylinositol 3-kinase, also abrogated protection by PMA.\Question: Does postconditioning protect rabbit hearts through a protein kinase C-adenosine A2b receptor cascade?

SOLUTION: Salvage of ischemic myocardium by postconditioning is dependent on activation of A2b receptors, which in turn depends on activation of PKC. It is still unclear why PKC activation is required to make the heart's adenosine become protective.

PROBLEM: Context: Evidence suggests that advance directives may improve end-of-life care among seriously ill patients, but improving completion rates remains a challenge.', 'This study tested the influence of increasing the number of options for completing an advance directive among seriously ill patients.', 'Outpatients (N = 316) receiving hemodialysis across 15 dialysis centers in the Philadelphia region between July 2014 and July 2015 were randomized to receive either the option to complete a brief advance directive form or expanded options including a brief, expanded, or comprehensive form. Patients in both groups could decline to complete an advance directive or take their selected version home. The primary outcome was a returned, completed advance directive. Secondary outcomes included whether patients wanted to complete an advance directive, decision satisfaction, quality of life at 3 months, and patient factors associated with advance directive completion.', 'Although offering more advance directive options was not significantly associated with increased rates of completion (13.1% in the standard group v. 12.2% in the expanded group, P = 0.80), it did significantly increase the proportion of patients who wanted to complete an advance directive and took one home (71.9% in standard v. 85.3% in expanded, P = 0.004). There was no difference in satisfaction (P = 0.65) or change in quality of life between groups (P = 0.63). A higher baseline quality of life was independently associated with advance directive completion (P = 0.006).\Question: Does a Randomized Trial of Expanding Choice set to Motivate Advance Directive Completion?

SOLUTION: These results suggest that although an expanded choice set may initially nudge patients toward completing advance directives without restricting choice, increasing actual completion requires additional interventions that overcome downstream barriers.

PROBLEM: Context: To assess the effectiveness of the combined use of fecal calprotectin (FC), anti-Saccharomyces cerevisiae antibody (ASCA), perinuclear staining antineutrophil antibody (pANCA), small intestinal permeability test (IP), and bowel wall ultrasonography measurement (BWUS) in the diagnostic work-up of children with suspected inflammatory bowel disease (IBD).', 'All children referred for initial assessment of possible IBD were eligible. Patients with symptoms or signs (right-lower quadrant mass, perianal disease, or hematochezia) mandating a complete work-up for IBD were excluded. All enrolled patients underwent a clinical, laboratory, radiographic, and endoscopic evaluation including biopsy examinations. The immunoglobulin (Ig)G and IgA ASCA, IgG pANCA, FC, IP, and BWUS were tested in all patients at the initial assessment.', 'A final diagnosis of IBD was made in 27 patients: 17 Crohn disease and 10 ulcerative colitis. Eighteen children had other gastrointestinal diagnoses (8 functional bowel disorders, 5 food allergy-mediated diseases, 4 infectious enterocolitis, 1 familial Mediterranean fever). In patients with simultaneous abnormal values of FC, BWUS, and ASCA/pANCA, the estimated probability of having IBD was 99.47%. Patients with negative results on all tests had a 0.69% of probability of IBD.\Question: Is combined use of noninvasive tests useful in the initial diagnostic approach to a child with suspected inflammatory bowel disease?

SOLUTION:
The incorporation of noninvasive diagnostic tests into the initial diagnostic approach may avoid unnecessary invasive procedures and facilitate clinical decision-making when the diagnosis of IBD in children is initially uncertain.