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]: Although the majority of evidence does not support association between Helicobacter pylori infection and ischaemic heart disease, the nature of this relationship may differ when virulence of the infecting strains are examined.', 'The prevalence of IgG antibody evidence of infection with CagA positive stains of H. pylori was investigated in stored plasma samples from 259 cases of myocardial infarction (aged 25-70 years, 74 males) and 259 population based controls from the same area in Northern Ireland. Two-hundred and seventy (52.1%) subjects were seropositive for anti-CagA IgG. CagA seropositivity was more common in cases than in controls: 56.4 vs 47.9%, odds ratio for seropositivity in cases (95% CI) 1.41 (1.00, 1.99). Substantial attenuation of this relationship occurred on adjustment for age, sex, number of siblings, smoking and measures of socio-economic status: odds ratio (95% CI) 1.16 (0.79, 1.70). A similar pattern was seen for seropositivity for all H. pylori strains.
[EX A]: Is infection with virulent strains of Helicobacter pylori associated with ischaemic heart disease : evidence from a population-based case-control study of myocardial infarction?

[EX Q]: Epinephrine commonly is added to epidural opioids and local anesthetics, however, little is known about the fate of epidurally administered epinephrine. Studies have identified the epinephrine metabolizing enzyme, catechol-O-methyl transferase (COMT), in the cranial meninges of several species. The purpose of this study was to determine whether the spinal meninges also contain COMT and are capable of metabolizing epinephrine. If so, then the spinal meninges may have an important impact in limiting the bioavailability of epinephrine in both the spinal cord and epidural space.', 'Spinal meningeal specimens measuring 4 cm2 were obtained from monkeys (M. nemestrina) and farm-bred pigs and were incubated in bicarbonate-buffered mock cerebrospinal fluid. Epinephrine (200 micrograms base) was added at t = 0, and 200 min later, the mock cerebrospinal fluid was collected for metanephrine analysis. In separate experiments, pig meningeal specimens were separated into dura mater, pia-arachnoid mater, and pia mater, and the experiments were repeated to determine which meninx had the greatest COMT activity.', 'Metanephrine was produced by monkey meninges at the rate of 0.47 ng.min-1.cm-2 and by pig meninges at the rate of 0.23 ng.min-1.cm-2 (P > 0.05). The pia-arachnoid meninx produced metanephrine at a greater rate (4.48 +/- 0.46 ng.min-1.mg-1 tissue) than did the pia mater (1.3 +/- 0.15 ng.min-1.mg-1 tissue) or dura mater alone (1.82 +/- 0.23 ng.min-1.mg-1 tissue).
[EX A]: Is epinephrine metabolized by the spinal meninges of monkeys and pigs?

[EX Q]: Although calcific aortic stenosis is common, calcification of the other three heart valves is not. The aortic valve interstitial cell (VIC) has been implicated in the pathogenesis of aortic stenosis. Proinflammatory stimulation of aortic VICs induces an osteogenic and inflammatory phenotypic change. We hypothesized that the VICs of the other heart valves do not undergo these changes. Using isolated human VICs from normal aortic, mitral, pulmonary, and tricuspid valves, our purpose was to compare the osteogenic response to proinflammatory stimulation via toll-like receptor 4 (TLR-4).', 'Aortic, pulmonic, mitral, and tricuspid (n=4 for each valve type) VICs were isolated from hearts valves explanted from patients undergoing cardiac transplantation. Cells were cultured and grown to confluence in passage 2-6 before treatment with Lipopolysaccharide (LPS) (100-200 ng/mL) for 24 or 48 h. Cells were characterized by immunofluorescent staining. TLR-4 expression was analyzed (immunoblotting, flow cytometry). Bone morphogenetic protein 2 and intercellular adhesion molecule 1 production were determined (immunoblotting). Monocyte chemoattractant protein 1 levels were determined by enzyme-linked immunosorbent assay. Statistics were by Mann-Whitney U test.', 'TLR-4 stimulation induced bone morphogenetic protein 2 production only in aortic VICs (P<0.05). Intra-cellular adhesion molecule 1 production and monocyte chemoattractant protein 1 secretion increased in a similar fashion among TLR-4-stimulated VICs from all four valves.
[EX A]:
Is aortic valve calcification mediated by a differential response of aortic valve interstitial cells to inflammation?