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]: Accurate evaluation of the biological behavior of Gastrointestinal stromal tumor and careful selection of patients with a high risk for tumor recurrence are necessary. In the present study, we analyzed prognostic factors in patients with GIST.', 'A total of 214 patients who had undergone curative resection of a localized primary gastric GIST without adjuvant therapy were enrolled in this retrospective study. Prognostic factors were analyzed. The growth pattern was classified as intramural, endoluminal, exoluminal, or mixed- type.', 'On univariate and multivariate analyses, recurrence was predicted by exoluminal or mixed-type (hazard ratio [HR]=3.7, p=0.043), tumor size of >3.5 cm (HR=7.1, p=0.01), and mitotic rate of >5/50 high-power fields (HR=7.9, p<0.001).
[EX A]: Is macroscopic type a prognostic factor for recurrence-free survival after resection of gastric GIST?

[EX Q]: Pulmonary hypertension (PH) is associated with a poor prognosis in diffuse lung disease (DLD). A study was undertaken to compare the prognostic significance of invasive and non-invasive parameters in patients with DLD and suspected PH.', 'Hospital records of consecutive patients with DLD undergoing right heart catheterisation (RHC) were reviewed (n = 66). Mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR) and non-invasive variables were examined against early (within 12 months) and overall mortality. A priori thresholds were examined against early mortality. Relationships between mPAP, PVR and non-invasive markers were assessed.', 'Fifty patients had PH on RHC (mean (SD) mPAP 33.5 (11.8) mm Hg, PVR 5.9 (4.3) Wood units (WU)). Raised PVR was strongly associated with early mortality (odds ratio (OR) 1.30; 95% confidence interval (CI) 1.11 to 1.52; p = 0.001), with PVR > or = 6.23 WU being the optimal threshold after adjustment for age, gender, composite physiological index (CPI) and diagnosis of idiopathic pulmonary fibrosis (OR 11.09; 95% CI 2.54 to 48.36; p = 0.001). Early mortality was linked, albeit less strongly, to right ventricular dilation at echocardiography, but not to other non-invasive variables or mPAP. Overall mortality was most strongly associated with increasing CPI levels. Correlations between PVR and non-invasive variables were moderate (R(2) <0.32), improving little following construction of a multivariate index which did not itself predict mortality.
[EX A]: Does pulmonary vascular resistance predict early mortality in patients with diffuse fibrotic lung disease and suspected pulmonary hypertension?

[EX Q]: To show whether the ratios of squalene and cholesterol precursor sterols to cholesterol and cholestanol and plant sterols to cholesterol change differently in plasma and especially in the red cells of hypercholesterolemic children during consumption of plant stanol and sterol ester spreads.', 'In a randomized, double-blind, crossover study, hypercholesterolemic children (n = 23) consumed low-fat plant stanol and sterol ester spreads for 5-week periods separated by a 5-week washout period. Plasma and red cell lipids, squalene, and noncholesterol sterols were measured before and at the end of each period.', 'The plant stanol and sterol ester spreads lowered plasma total (-9% and -6%, respectively) and low-density lipoprotein (-12% and -9%) cholesterol but had no effect on red cell cholesterol, high-density lipoprotein cholesterol, or plasma triglycerides. The ratios of plasma and red cell sitosterol and campesterol to cholesterol decreased by 32% to 36% (P <.001) with the plant stanol ester and increased by 40% to 52% (P <.001) with the sterol ester spread.
[EX A]:
Are red cell and plasma plant sterols related during consumption of plant stanol and sterol ester spreads in children with hypercholesterolemia?