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.

Example Input: Context: In dialysis patients, volume overhydration is common and is related to increased risk of cardiovascular morbidity and mortality. However, it remains unclear whether volume overload imposes those detrimental effects through endothelial dysfunction.', 'In this cross-sectional study, 81 stable patients on continuous ambulatory peritoneal dialysis in a single center were recruited. Volume status was evaluated by extracellular water, assessed by bioimpedance analysis, and normalized to individual height (nECW). Endothelial function was estimated by endothelial-dependent flow-mediated dilatation (FMD) of the brachial artery and expressed as percentage change relative to baseline diameter.', 'There were 37 male and 44 female patients (mean age 61 +/- 12 years, dialysis vintage 20 +/- 23 months). FMD in female patients was significantly higher than that in male patients (9.17% +/- 6.23% vs 6.31% +/- 5.01%, p < 0.05). FMD was negatively correlated with weight (r = -0.308, p < 0.01), body mass index (r = -0.242, p < 0.05), systolic blood pressure (r = -0.228, p < 0.05), ECW (r = -0.404, p < 0.001), and nECW (r = -0.418, p < 0.001). No correlation was found between FMD and other variables. In multiple stepwise regression analysis, calcium x phosphate product (beta = 0.422, p < 0.001), nECW (beta = -0.343, p < 0.01), and dialysis vintage (beta = -0.237, p < 0.05) were independent determinants of FMD (adjusted R(2) = 0.327 for this model).
Answer: There was independent correlation between index of volume status and FMD, and higher nECW was related to worse endothelial function. The results of this study may help us understand the underlying mechanism of volume overhydration leading to increased cardiovascular morbidity and mortality in dialysis patients.
Example Output: Is volume overhydration related to endothelial dysfunction in continuous ambulatory peritoneal dialysis patients?

Example Input: Context: The aim of this study was to determine the clinical significance and prognostic impact of extranodal metastasis (EM) in gastric carcinoma.', 'The study included 1023 patients who underwent gastrectomy with lymphadenectomy for primary gastric carcinoma between January 1993 and December 1996. EM was defined as the presence of tumour cells in extramural soft tissue that was discontinuous with either the primary lesion or locoregional lymph nodes.', "EM was detected in 146 (14.3 per cent) of the 1023 patients and in 1060 (3.0 per cent) of the 35 811 nodules that were retrieved as 'lymph nodes' from adipose connective tissues. The incidence of EM was significantly higher in patients with tumours that were large (diameter 10 cm or more), infiltrative, deeply invading or undifferentiated and in those with lymph node, peritoneal or liver metastases, or lymphatic or vascular involvement. After curative operation overall survival was significantly worse for patients with EM than those without (P < 0.001). Multivariate analysis identified EM as an independent prognostic factor (hazard ratio 1.82 (95 per cent confidence interval 1.23 to 2.71); P = 0.003).
Answer: EM is an independent prognostic factor and should therefore be included in the tumour node metastasis (TNM) staging system.
Example Output: Is extranodal metastasis an indicator of poor prognosis in patients with gastric carcinoma?

Example Input: Context: Studies on the use of intradetrusor botulinum toxin A injection for children with neuropathic bladders are insufficient and the results are controversial. The aim of the present study was to evaluate the effect of intradetrusor botulinum toxin A injection for children with neuropathic bladders that are resistant to anticholinergic treatment, and to reveal any criteria indicating treatment success.', 'Hospital records were reviewed of 16 children with neuropathic bladders due to myelomeningocele, and who had botulinum toxin A injections between 2007 and 2010. Botulinum toxin A (10 units/kg) was injected endoscopically into various sites of the detrusor, except the trigone. The success was defined as complete dryness between clean intermittent catheterizations. Urodynamic studies before and after the application were evaluated and parameters, including bladder capacity (measured/expected) and compliance, were also analyzed. Reviewing the results, patients were then classified into two groups: as having fibrotic bladders (noncompliant, acontractile bladders with high pressures) or overactive bladders. Urodynamic findings and therapy success were then compared between the groups.', 'A total of 19 injections, including repeat injections in three patients, were performed. Results of the 16 initial injections were evaluated. Nine patients had detrusor overactivity, and five out of nine (56%) applications in this group resulted in complete dryness between clean intermittent catheterizations. In bladders with typical detrusor overactivity, there was a significant increase in both the capacity (from 0.53 to 0.74) and compliance (from 4.7 to 8.6 ml/cm H2O). Looking at the seven patients that displayed fibrotic bladders with very low compliance and no contraction at all, none of them presented with notable clinical improvement from injections. Comparing the urodynamic findings, there was no significant difference in compliance (3.1 ml/cm H2O before and 3.5 ml/cm H2O after) and bladder capacity (0.58 before and 0.52 after the treatment) in the fibrotic bladders.
Answer: Despite its worldwide usage and FDA approval, studies on the effectiveness of botulinumtoxin A on neuropathic bladders in children are controversial. There are now numerous studies attesting to the good results of BoNTA in neuropathic detrusor overactivity; however, only scarce reports comment on the specific features of the disease process among patients and reasons for failure in some. In our study, reviewing the urodynamic findings carefully, it was observed that the patients who did not respond to injections were the ones with no contractions, despite high pressures and low compliance. Therefore, describing the indications of BoNTA as neuropathic detrusor overactivity and urinary incontinence despite anticholinergic medications may lead to mistreatment of patients in the decompensated phase of a hyper-reflexive detrusor. Pretreatment urodynamic evaluation might be a good indicator, without biopsies, of estimating the degree of fibrosis and the patients who will benefit from the injection.
Example Output:
Is botulinum injection useless on fibrotic neuropathic bladders?