Given a passage, 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.

Example Input: Physiological roles of apelin and its specific receptor APJ signaling were investigated in vascular smooth muscle cells (VSMCs). The present study determined whether apelin activates myosin light chain (MLC), a major regulatory event in initiating smooth muscle contraction.', 'To assess MLC activation, we performed Western blot and immunohistochemical studies using an antibody against the phospho-MLC. In VSMCs, apelin induces the phosphorylation of MLC in a concentration-dependent manner with a peak at 2 minutes. Pretreatment of VSMCs with pertussis toxin abolishes the apelin-induced phosphorylation of MLC. Inhibition of protein kinase C (PKC) with GF-109203X markedly attenuated the apelin-induced MLC phosphorylation. In addition, methylisobutyl amiloride, a specific inhibitor of the Na+/H+ exchanger (NHE), and KB-R7943, a potent inhibitor for the reverse mode of the Na+/Ca2+ exchanger (NCX), significantly suppressed the action of apelin. In wild-type mice, apelin phosphorylates MLC in vascular tissue, whereas it had no response in APJ-deficient mice by Western blot and immunohistochemistry. Apelin-induced phosphorylation of MLC was accompanied with myosin phosphatase target subunit phosphorylation.
Example Output: Does apelin stimulate myosin light chain phosphorylation in vascular smooth muscle cells?

Example Input: To investigate the incidence of acute kidney injury after cardiac surgery and its association with mortality in a patient population receiving ibuprofen and gentamicin perioperatively.', 'Retrospective study with Cox regression analysis to control for possible preoperative, intraoperative and postoperative confounders.', 'University hospital-based single-center study.', 'All patients who underwent coronary artery bypass grafting valve surgery during 2012.', 'None.', 'Acute surgery within 24 hours of coronary angiography, previous nephrectomy, preoperative sCr >2.26 mg/dL and selective cerebral perfusion during cardiopulmonary bypass were used as exclusion criteria. Acute kidney injury was defined, using the Acute Kidney Injury Network (AKIN) criteria. Six hundred eight patients were included in the study. Mean age was 68.2 9.7 years, and 81% were males. Acute kidney injury was seen in 28.1% of the patients. Overall mortality at one year was 7% and 3% in the no-AKI group. At one year, mortality was 15% in patients with AKIN stage 1 and AKIN stage 2 compared to 70% in AKIN stage 3. A hazard ratio of 2.34 (95% CI: 1.21-4.51, p = 0.011) and 5.62 (95% CI: 2.42-13.06), p<0.0001) were found for AKIN stage 1 and 2/3 combined, respectively.
Example Output: Is acute kidney injury independently associated with higher mortality after cardiac surgery?

Example Input: To bring further understanding to the relationship between hormonal therapy (HT) and breast arterial calcification (BAC).', 'Of women arriving for breast cancer screening mammography, 1995 consented to complete a survey and have their mammograms analyzed for the presence of BAC. The survey assessed HT use and major risk factors for CAD.', 'Of the 1919 women with complete data, there were 268 with BAC (14%). When categorized into three age groups, BAC was present in 40.7% of the women > or =65, 10.9% of those 55-64 and 3.0% of those <55. The > or =65 year-old group showed a nearly 50%-point lower prevalence of BAC among HT users compared with women who were not on HT (25.8% versus 74.2%, respectively, p=0.006). With age included as a continuous variable, past use of HT was significantly associated with a lower prevalence of BAC (p<0.03), while the presence of diabetes or a history of stroke were significantly associated with a higher prevalence of BAC (p<0.002).
Example Output:
Is hormonal therapy associated with a lower prevalence of breast arterial calcification on mammography?