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: Blood oxygenation level-dependent (BOLD)-weighted and vessel-encoded arterial spin labeling (VE-ASL) MRI provide complementary information and can be used in sequence to gauge hemodynamic contributions to cerebrovascular reactivity. Here, cerebrovascular reactivity is assessed using dual echo VE-ASL MRI to understand how VE labeling preparations influence BOLD and ASL contrast in flow-limited and healthy perfusion territories.', 'Patients (n=12; age=55 +/- 14 years; 6F/6M) presenting with ischemic steno-occlusive cerebrovascular disease underwent 3.0T angiographic imaging, T1 -weighted structural, and planning-free dual echo hypercarbic hyperoxic (i.e., carbogen) VE-ASL MRI. Vasculopathy extent, timecourses, and cerebrovascular reactivity (signal change and Z-statistic) for different VE-ASL images were contrasted across flow territories and Bonferroni-corrected P-values reported.', 'BOLD cerebrovascular reactivity (i.e., long-TE VE-ASL) Z-statistics were similarly sensitive to asymmetric disease (P0.002) regardless of labeling scenario. Cerebral blood flow reactivity correlated significantly with BOLD reactivity (Z-statistic). However, BOLD signal changes did not differ significantly between labeling scenarios (P>0.003) or across territories (P>0.002), indicating BOLD signal changes in response to carbogen offer low sensitivity to lateralizing disease.
Answer: Dual echo VE-ASL can provide simultaneous cerebral blood flow and qualitative BOLD contrast consistent with lateralizing disease severity in patients with asymmetric steno-occlusive disease. The methodological strengths and limitations of composite BOLD and VE-ASL measurements in the clinic are discussed.
Example Output: Do dual echo vessel-encoded ASL for simultaneous BOLD and CBF reactivity assessment in patients with ischemic cerebrovascular disease?

Example Input: Context: Barrett esophagus (BE) is considered precursor condition of esophageal adenocarcinoma. Its incidence and prevalence are increasing in general population. Studies reported that metabolic syndrome (MS) or diabetes mellitus (DM) is related to increased risk of BE. Current study was to assess and better understand the relationship between MS /DM and BE.', "Electronic search was conducted in the database Pubmed/Medline (-December, 2015), Embase (-December, 2015), Cochrane Library (-December, 2015), and Web of Knowledge (-December, 2015). Studies included were assessed with summary odds ratios (ORs) with 95% confidence intervals (CIs) and compared exposure group with control group. The heterogeneity was examined by the funnel plot and the Egger's test. Subgroup analyses and sensitive analyses were performed for the detection of possible heterogeneity and impact on stability of analysis results.", "Twelve publications met the criteria and included 355,311 subjects were analyzed. The pooled results showed MS was closely associated with increased risk of BE (OR=1.23; 95%CI 1.03-1.47; P=0.024), and yet DM did not significantly increase the risk of BE (OR=1.07; 95%CI 0.82-1.38; P=0.627). Substantial heterogeneities were detected. No significant publication bias was detected by Egger's test (P=0.23).
Answer: Based on the results of current meta-analysis, MS is associated with increased risk of BE. Further long-term follow-up prospective study needs to verify the current results, and definite pathophysiological mechanism needs to be further investigated and clearly elucidated.
Example Output: Is metabolic syndrome associated with increased risk of Barrett esophagus : A meta-analysis?

Example Input: Context: Androgens cause regression of human hair follicles in the parietofrontal scalp, but the precise mechanisms by which they do so are unknown. Although many investigators have elucidated the effect of androgens on hair growth by using rodents and other animals, some of the evidence is conflicting.', 'To investigate the effect of androgens on mouse hair regrowth and hair cycle by using androgen receptor knockout (ARKO) mice. Methods We examined the effects of dihydrotestosterone (DHT) on hair regrowth by using ARKO mice and wild-type (WT) littermates, compared the hair cycles in ARKO mice and WT littermates by histology and histomorphometry, and measured hair length and thickness in ARKO mice and WT littermates.', 'DHT inhibited the hair regrowth of WT mice but not that of their ARKO littermates. The anagen phase in the second hair cycle was longer in ARKO mice than in their WT littermates. The hair of ARKO mice was longer and thicker than that of their WT littermates.
Answer: Androgens inhibit hair growth in mice, and this inhibition might be caused by androgen-androgen receptor signals.
Example Output:
Does dihydrotestosterone inhibit murine hair growth via the androgen receptor?