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: Preoperative anemia may affect postoperative mortality and morbidity following elective cranial operations.', 'The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was used to identify elective cranial neurosurgical cases (2006-2012). Morbidity was defined as wound infection, systemic infection, cardiac, respiratory, renal, neurologic, and thromboembolic events, and unplanned returns to the operating room. For 30-day postoperative mortality and morbidity, adjusted odds ratios (ORs) were estimated with multivariable logistic regression.', 'Of 8015 patients who underwent elective cranial neurosurgery, 1710 patients (21.4%) were anemic. Anemic patients had an increased 30-day mortality of 4.1% versus 1.3% in non-anemic patients (P < 0.001) and an increased 30-day morbidity rate of 25.9% versus 14.14% in non-anemic patients (P < 0.001). The 30-day morbidity rates for all patients undergoing cranial procedures were stratified by diagnosis: 26.5% aneurysm, 24.7% sellar tumor, 19.7% extra-axial tumor, 14.8% intra-axial tumor, 14.4% arteriovenous malformation, and 5.6% pain. Following multivariable regression, the 30-day mortality in anemic patients was threefold higher than in non-anemic patients (4.1% vs 1.3%; OR = 2.77; 95% CI: 1.65-4.66). The odds of postoperative morbidity in anemic patients were significantly higher than in non-anemic patients (OR = 1.29; 95% CI: 1.03-1.61). There was a significant difference in postoperative morbidity event odds with a hematocrit level above (OR = 1.07; 95% CI: 0.78-1.48) and below (OR = 2.30; 95% CI: 1.55-3.42) 33% [hemoglobin (Hgb) 11 g/dl].
Answer: Preoperative anemia in elective cranial neurosurgery was independently associated with an increased risk of 30-day postoperative mortality and morbidity when compared to non-anemic patients. A hematocrit level below 33% (Hgb 11 g/dl) was associated with a significant increase in postoperative morbidity.

SOLUTION: Does preoperative anemia increase postoperative morbidity in elective cranial neurosurgery?

PROBLEM: Context: Human induced pluripotent stem cells (iPSCs) play an important role in disease modeling and drug testing. However, the current methods are time-consuming and lack an isogenic control.', 'This study sought to establish an efficient technology to generate human PSC-based disease models with isogenic control.', 'The ion channel genes KCNQ1 and KCNH2 with dominant negative mutations causing long QT syndrome types 1 and 2, respectively, were stably integrated into a safe harbor AAVS1 locus using zinc finger nuclease technology.', 'Patch-clamp recording revealed that the edited iPSC-derived cardiomyocytes (iPSC-CMs) displayed characteristic long QT syndrome phenotype and significant prolongation of the action potential duration compared with the unedited control cells. Finally, addition of nifedipine (L-type calcium channel blocker) or pinacidil (KATP-channel opener) shortened the action potential duration of iPSC-CMs, confirming the validity of isogenic iPSC lines for drug testing in the future.
Answer: Our study demonstrates that iPSC-CM-based disease models can be rapidly generated by overexpression of dominant negative gene mutants.

SOLUTION: Does genome editing of isogenic human induced pluripotent stem cells recapitulate long QT phenotype for drug testing?

PROBLEM: Context: The aim of this study was to investigate the smoking status of lung cancer patients and to confirm the risk of smoking for patients undergoing lung cancer surgery.', 'We conducted a retrospective study of patients undergoing lung cancer surgery. Between May 2004 and March 2013, 716 patients underwent lung cancer surgery at our institution. Based on smoking status, the patients were classified into 3 groups: nonsmoker, past smoker, and current smoker. Based on exclusion criteria, a final total of 670 patients were investigated for the association between smoking status and postoperative complications. In addition, we explored the effect of smoking on survival after surgery.', 'There were 254 non-smokers, 246 past smokers, and 170 current smokers. The percent of female patients, adenocarcinoma, and stage IA cancer was highest in the nonsmokers. Respiratory function was significantly impaired in past and current smokers. Respiratory and cardiac complications were found less frequently in non-smokers (11.4%) followed by 17.1% of past smokers and 21.2% of current smokers (p = 0.0226). Univariate analysis showed that smoking was a significantly poor prognostic factor for overall survival. The 5-year survival rates for non-smokers, past, and current smokers were 81.4, 65.4, and 68.8%, respectively (p = 0.0003).
Answer: Smokers with lung cancer tended to have advanced lung cancer, impaired pulmonary function, and high morbidity after lung cancer surgery. Although multivariate analysis did not show that smoking was associated with poor outcome, non-smokers had significantly better overall survival, even for patients with stage IA lung cancers.

SOLUTION:
Is smoking a perioperative risk factor and prognostic factor for lung cancer surgery?