TASK DEFINITION: Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
PROBLEM: Context: 99mTc-HMPAO is a well-established isotope useful in the detection of regional cerebral blood flow. Diabetes gives rise to arterial atherosclerotic changes that can lead to significant end organ dysfunction, prominently affecting perfusion to the heart, kidneys, eyes and brain. In the current study, we investigated the role of 99mTc-HMPAO cerebral perfusion scans in detecting early vascular changes in the diabetic brain.', 'Cerebral perfusion studies were performed on both control and streptozotocin-(STZ) induced diabetic male Wistar rats. Rat brain imaging using a gamma camera was performed for each group 0.5, 2, 4, and 24 hours post 99mTc-HMPAO injection. Data processing for each cerebral perfusion scan was performed by drawing a region of interest (ROI) circumferentially around the brain (B). Background (BKG) due to signal from the soft tissue of each rat was subtracted. Brain 99mTc-HMPAO uptake minus background counts (net brain counts; NBC) were then compared between the two groups.', 'The NBC (mean +/- SD) for the STZ group were statistically significantly higher (p = 0.0004) than those of the control group at each of the time points studied.
Answer: 99mTc-HMPAO brain scan may be useful in the detection of early atherosclerotic changes in the diabetic rat brain.

SOLUTION: Does perfusion scanning using 99mTc-HMPAO detect early cerebrovascular changes in the diabetic rat?

PROBLEM: Context: Patients with chronic heart failure (CHF) have multiple abnormalities of autonomic regulation that have been associated to their high mortality rate. Heart rate recovery immediately after exercise is an index of parasympathetic activity, but its prognostic role in CHF patients has not been determined yet.', 'Ninety-two stable CHF patients (83M/9F, mean age: 51+/-12 years) performed an incremental symptom-limited cardiopulmonary exercise testing. Measurements included peak O2 uptake (VO2p), ventilatory response to exercise (VE/VCO2 slope), the first-degree slope of VO2 for the 1st minute of recovery (VO2/t-slope), heart rate recovery [(HRR1, bpm): HR difference from peak to 1 min after exercise] and chronotropic response to exercise [%chronotropic reserve (CR, %)=(peak HR-resting HR/220-age-resting HR)x100]. Left ventricular ejection fraction (LVEF, %) was also measured by radionuclide ventriculography.', 'Fatal events occurred in 24 patients (26%) during 21+/-6 months of follow-up. HRR1 was lower in non-survivors (11.4+/-6.4 vs. 20.4+/-8.1; p<0.001). All cause-mortality rate was 65% in patients with HRR1<or=12 bpm versus 11% in patients with HRR1>12 bpm (log-rank: 32.6; p<0.001). By multivariate survival analysis, HRR1 resulted as an independent predictor of mortality (chi2=19.2; odds ratio: 0.87; p<0.001) after adjustment for LVEF, VO2p, VE/VCO2 slope, CR and VO2/t-slope. In a subgroup of patients with intermediate exercise capacity (VO2p: 10-18, ml/kg/min), HRR1 was a strong predictor of mortality (chi2: 14.3; odds ratio: 0.8; p<0.001).
Answer: Early heart rate recovery is an independent prognostic risk indicator in CHF patients and could be used in CHF risk stratification.

SOLUTION: Does early heart rate recovery after exercise predict mortality in patients with chronic heart failure?

PROBLEM: Context: There have seen several studies evaluating the efficacy of anti-tumor necrosis factor α (anti-TNFα) compared with conventional therapy (i.e. immunomodulators, mesalamine, or placebo) at preventing postoperative Crohn's disease (CD) recurrence. The results of these studies have been variable and the magnitude by which anti-TNFα therapy alters the natural history of CD in the postoperative setting has not yet been fully defined.", 'A comprehensive search of PubMed/MEDLINE, Scopus, CINAHL, and Cochrane databases was performed (May 2014). All studies on adult patients with CD that compared anti-TNFα therapy versus conventional therapy or placebo to prevent CD recurrence were included. Meta-analysis was performed using the Mantel-Haenszel (fixed effects) model with odds ratio (OR) to assess for clinical remission.', 'In the pooled analysis, there was a higher frequency of achieving clinical remission beyond 1 year from time of surgery among patients receiving anti-TNFα therapy compared with conventional therapy [OR 6.41; 95% confidence interval (CI) 2.88-14.27]. There was also a significantly higher rate of achieving both endoscopic (OR 26.44; 95% CI 10.48-66.68) and histologic remission (OR 9.80; 95% CI 2.54-37.81) in the anti-TNFα therapy group compared with the conventional therapy group.
Answer: Anti-TNFα therapy is more effective at preventing clinical, endoscopic, and histologic recurrence of CD beyond 1 year from time of surgery compared with conventional therapy.

SOLUTION:
Is antitumor necrosis factor α more effective than conventional medical therapy for the prevention of postoperative recurrence of Crohn 's disease : a meta-analysis?