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.

Ex Input:
Context: Pineal function has been considered particularly as a neuroendocrine modulator in hormone responsive tumors, like the hormone-dependent mammary tumors. The complexity of the gland function, moreover, is denoted by the presence of a local renin-angiotensin-system (RAS) that regulates melatonin biosynthesis. Classically, angiotensin II (Ang II) has been considered as the effector peptide of the RAS, but Ang II is not the only active peptide. Several of its degradation products, including angiotensin III (Ang III) and angiotensin IV (Ang IV) also possess biological functions. These peptides are formed via the activity of several aminopeptidases. Our aim is to know their role in the regulation of pineal RAS and breast cancer.', 'Aminopeptidase N (APN), aminopeptidase B (APB) and aminopeptidase A (aspartyl- and glutamyl-aminopeptidase, APA) activities are measured in the pineal gland of rats with breast cancer induced by N-methyl nitrosourea (NMU).', 'Aminopeptidase activities were measured fluorimetrically using their corresponding aminoacyl-beta-naphthylamides as substrates.', 'Specific APN and APB activities in pineal gland of controls and NMU-treated rats were not modified. Aspartyl aminopeptidase activity significantly decreased in NMU-treated rats when compared with control group. On the contrary, glutamyl aminopeptidase activity did not show significant differences between groups.
Answer: We propose that the local RAS in pineal gland is modified in rats with breast cancer induced by NMU through the inhibition of AspAP activity, which may lead to increased levels of Ang II. Ang II could be responsible of the overproduction of melatonin, supporting a mechanism to restrain the promotion and/or progression of breast cancer.

Ex Output:
Are renin-angiotensin system-regulating aminopeptidase activities modified in the pineal gland of rats with breast cancer induced by N-methyl-nitrosourea?

Ex Input:
Context: Serum ghrelin levels are elevated in uremic patients. However, no data are available on the relationship between metabolic syndrome and serum ghrelin levels in peritoneal dialysis (PD) patients.', 'Metabolic syndrome and its components were defined using diagnostic criteria recommended by the International Diabetes Federation. Fasting serum samples were taken from 30 PD patients. Serum ghrelin levels were measured by using a commercial enzyme-linked immunosorbent assay kit.', 'Of the 30 PD patients, 53.3% (16/30) had metabolic syndrome. Fasting serum ghrelin corrected inversely with metabolic syndrome among these PDs patients (p = 0.002). By odds ratio (OR) analysis of metabolic syndrome and metabolic syndrome diagnostic criteria, the predictors for metabolic syndrome are fasting glucose [OR: 39.00; 95% confidence interval (CI): 3.80 to 399.85; p < 0.001], triglycerides (OR: 37.50; 95% CI: 3.64 to 386.51; p < 0.001), and waist circumference (OR: 4.20; 95% CI: 1.95 to 9.03; p < 0.001). Univariate linear regression analysis showed that body weight (r = -0.461, p = 0.010), waist circumference (r = -0.390, p = 0.033), and body mass index (r = -0.438, p = 0.016) were negatively correlated with serum ghrelin, and serum high density lipoprotein [HDL (r = 0.626, p < 0.001)] was positively correlated with serum ghrelin. Multivariate forward stepwise linear regression analysis of the significant variables showed that HDL (R(2) change = 0.392; p < 0.001) was the independent predictor of serum ghrelin in PD patients and explained 39.2% of the variance.
Answer: These results indicate an inverse association between circulating fasting ghrelin and metabolic syndrome in PD patients. Serum HDL was associated with serum ghrelin among PD patients.

Ex Output:
Is fasting serum ghrelin level associated with metabolic syndrome in peritoneal dialysis patients?

Ex Input:
Context: Blood O(2) saturation and lactate concentration gradients from superior vena cava (SVC) to pulmonary artery (PA) occur in critically ill patients. These gradients (DeltaSO(2) and Delta[Lac]) may be positive or negative. We tested the hypothesis that positive DeltaSO(2) and Delta[Lac] are associated with improved survival in critically ill patients.', 'Multinational, prospective observational study conducted in six medical and surgical ICUs.', 'Consecutive sample of 106 adults requiring insertion of a pulmonary artery catheter (PAC). Average age was 59.5 +/- 15.5 years, APACHE II score was 15.5 +/- 6.7 (mean +/- SD). Main outcome measure was 28-day mortality.', 'None.', 'We drew blood samples from the proximal and distal ports of PACs every 6 h from the time of PAC insertion (Initial measurement) until its removal (Final measurement). Samples were analyzed for SO(2), [Lac], glucose concentration and blood gases. Hemodynamic measurements were obtained after blood samples. We monitored patients for 30.9 +/- 11.0 h. Overall mortality rate was 25.5%. More survivors had mean and final DeltaSO(2) > or = 0 and Delta[Lac] > or = 0 than decedents (p < 0.01; p < 0.05 respectively). On the average, DeltaSO(2) and Delta[Lac] were positive in survivors and negative in decedents. Survival odds ratios for final measurements of DeltaSO(2) > or = 0 and Delta[Lac] > or = 0 were 19.22 and 7.70, respectively (p < 0.05).
Answer: A strong association exists between positive DeltaSO(2) and Delta[Lac] and survival in critically ill patients. Whether therapy aimed at increasing DeltaSO(2) and Delta[Lac] results in improved ICU survival remains to be determined.

Ex Output:
Are central venous to mixed venous blood oxygen and lactate gradients associated with outcome in critically ill patients?