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.

[EX Q]: Erectile dysfunction (ED) and atherosclerotic cardiovascular disease (ASCVD) share many common risk factors, and vascular ED is a marker for increased ASCVD risk. Low 25-hydroxyvitamin D [25(OH)D] concentrations have been associated with increased ASCVD risk, but less is known regarding the relationship of low 25(OH)D with ED. We determined whether 25(OH)D deficiency is associated with ED independent of ASCVD risk factors.', 'We performed cross-sectional analyses of 3390 men aged 20 years free of ASCVD who participated in NHANES 2001-2004. Serum 25(OH)D was measured by the DiaSorin radioimmunoassay; deficiency was defined as levels <20ng/ml (<50nmol/L). Self-reported ED, assessed by a single validated question, was defined as men who reported being "never" or "sometimes able" to maintain an erection. We assessed the relationship between 25(OH)D deficiency and ED prevalence using adjusted Poisson regression methods.', 'After accounting for NHANES sampling, the weighted prevalence of 25(OH)D deficiency and of ED were 30% and 15.2%, respectively. 25(OH)D levels were lower in men with vs. those without ED (mean 22.8 vs 24.3ng/mL, respectively; p=0.0005). After adjusting for lifestyle variables, comorbidities, and medication use, men with 25(OH)D deficiency had a higher prevalence of ED compared to those with levels 30ng/ml (Prevalence Ratio 1.30, 95% CI 1.08-1.57).
[EX A]: Is vitamin D deficiency independently associated with greater prevalence of erectile dysfunction : The National Health and Nutrition Examination Survey ( NHANES ) 2001-2004?

[EX Q]: Because of greater recognition and improved imaging capabilities, intraductal papillary mucinous neoplasms (IPMNs) are being diagnosed with increasing frequency. IPMNs of the main pancreatic duct cause symptoms and lead to pancreatitis. Side-branch (SB) IPMNs are thought to cause symptoms less frequently, and their association with pancreatitis is not well defined.', 'Our purpose was to ascertain whether an association exists between SB-IPMN and pancreatitis.', 'Single-center, retrospective study.', 'Academic medical center.', 'A total of 305 patients underwent EUS examinations between October 2002 and October 2006 for pancreatic cystic lesions.', 'The main outcome measure was the frequency of acute or chronic pancreatitis that was not procedurally related.', 'Thirty-two patients had SB-IPMNs, and 11 (34%) had pancreatitis. Three patients reported a single episode, and 8 patients reported having recurrent episodes of pancreatitis. Overall, 17 (53%) patients had symptoms possibly attributable to SB-IPMN. Female sex (73% vs 38%) and multiple pancreatic lesions (54% vs 24%) were more commonly seen in those with pancreatitis, but were not statistically significant factors. Larger cyst size or cyst fluid marker levels did not appear associated with pancreatitis occurrence. EUS-FNA demonstrated communication with the pancreatic duct in 94% and thick, mucinous fluid in 84%.
[EX A]: Is pancreatitis frequent among patients with side-branch intraductal papillary mucinous neoplasia diagnosed by EUS?

[EX Q]: Leukemia inhibitory factor (LIF) is one of the key cytokines in the embryo implantation regulation. We investigated the prevalence of the LIF gene mutations in the population of infertile women that consisted of nulligravid and secondary infertile patients.', 'We designed a LIF gene mutation screening method that is based on the Temperature Gradient Gel Electrophoresis (TGGE). The population to screen consisted of 176 infertile women including group A of 147 nulligravid women and group B of 29 women with secondary infertility that had a history of either miscarriage or an ectopic pregnancy but no live births. The control population was comprised of 75 healthy fertile subjects. The groups of fertile controls and infertile patients were compared for statistically significant differences using the t-test.', 'Six potentially functional LIF gene mutations, the G to A transitions at the position 3400 leading to the valin to methionin exchange at codon 64 (V64M) in the AB loop region of the LIF protein, were detected. All of the six positive women were infertile. Four of them were nulligravid and two of them had history of spontaneous conception followed by early miscarriage. No positive TGGE samples were identified in the control group, which means that the frequency of functionally relevant mutations of the LIF gene in infertile women is significantly enhanced in comparison with controls (P<0.05, t-test).
[EX A]:
Are leukemia inhibitory factor gene mutations in the population of infertile women restricted to nulligravid patients?