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.
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Question: Context: Obstetric cholestasis is a cholestatic disease usually commencing in the third trimester of pregnancy and characterized by pruritus, elevation of liver enzymes, and increase in bile acids. The objective of this study was to compare the first trimester serum indicators of obstetric cholestasis with normal pregnancies.', 'Thirty-five patients diagnosed with obstetric cholestasis in a three-year period with first trimester biochemical assessment available were included in the study. Seventy patients with concordant pregnancy weeks, matched-age normal pregnancies were included as the control group. Pregnancy-associated plasma protein A (PAPP-A) and free beta-human chorionic gonadotropin (beta-hCG) levels were analyzed.', 'No difference was observed between the two groups in terms of age and week of pregnancy. While the mean PAPP-A level was 0.76 ± 0.31 multiples of the medians (MoM) in the obstetric cholestasis group, it was determined to be 1.5 ± 0.84 in the control group (p = 0.0001). Among the two groups, the hCG levels were found to be higher in the obstetric cholestasis group (1.2 ± 0.79 MoM vs. 0.98 ± 0.53, p = 0.041).
Answer: In this study, the first trimester PAPP-A levels in the obstetric cholestasis cases were found to be significantly lower than the control group. Low PAPP-A levels should be a warning for obstetric cholestasis.

Answer: Are pregnancy-associated plasma protein a levels decreased in obstetric cholestasis?


Question: Context: Oxidative stress has been considered to play a primary role in the pathogenesis of stress-induced gastric damage. The aim of this study was to investigate the effects of melatonin, ascorbic acid and β-carotene on stress-induced gastric mucosal damage.', 'Fifty-six male Wistar albino rats were divided into control, stress, stress + standard diet, stress + saline, stress + melatonin, stress + ascorbic acid and stress + β-carotene groups. The rats from stress groups were exposed to starvation, immobilization and cold by immobilizing for 8 h at +4°C following 72-hour food restriction. Following stress application, melatonin, ascorbic acid and β-carotene were administered for 7 days. Specimens of gastric tissue were prepared for microscopic and biochemical examinations.', 'Mean histopathological damage scores and mean tissue malondialdehyde levels were significantly decreased but mean tissue glutathione levels and glutathione peroxidase and superoxide dismutase activities were increased in treatment groups vs. stress groups in general. Mean histopathological damage scores of the stress + Mel group was lower than those of stress + D, stress + S, stress + β-car (p < 0.05) and stress + Asc groups (p < 0.005). Additionally, mean tissue catalase activity of the stress + Mel group was higher than that of stress + S (p < 0.005), stress + D (p < 0.05) and stress + β-car groups (p < 0.05).
Answer: Melatonin is more effective than ascorbic acid and β-carotene in improvement of gastric damage induced by intensive stress. We suggest that as well as the direct antioxidant and free radical scavenging potency of melatonin, its indirect effect via the brain-gut axis might account for its greater beneficial action against stress-induced gastric damage.

Answer: Is melatonin more effective than ascorbic acid and β-carotene in improvement of gastric mucosal damage induced by intensive stress?


Question: Context: Vascular calcification can predict cardiovascular (CV) morbidity and mortality in patients with end-stage renal disease. We evaluated the prevalence, association factors, and outcomes of chest X-ray-detected aortic arch calcification (AoAC) in patients undergoing peritoneal dialysis (PD).', 'We included 190 patients undergoing PD (mean age, 52.6\xa0±\xa014.3\xa0years) for whom chest radiographs were available. AoAC revealed by chest X-ray was graded from 0 to 3 according to an AoAC score (AoACS). Multiple regression analyses were used to determine the factors associated with AoACS. After adjusting for age, sex, PD duration, diabetes mellitus, mean blood pressure, and history of CV disease, the association between AoAC grading and mortality were assessed using the Kaplan-Meier curve and Cox proportional hazard model.', 'Age (p\xa0<\xa00.001), PD duration (p\xa0=\xa00.004), history of CV disease (p\xa0<\xa00.001), and renal Kt/V (p\xa0=\xa00.031) were associated with AoACS. After a mean follow-up of 55.1\xa0±\xa032.1\xa0months, patients with Grade 2 (p\xa0=\xa00.011) or Grade 3 (p\xa0<\xa00.001) AoAC had higher all-cause mortality than patients with Grade 0 AoAC. In addition, patients with Grades 2 and 3 AoAC had higher CV-related mortality than those with Grades 0 and 1 AoAC (p\xa0=\xa00.013). Grade 2 [hazard ratio (HR)\xa0=\xa02.736; 95% confidence interval (CI), 1.038-7.211; p\xa0=\xa00.042] and Grade 3 AoAC (HR\xa0=\xa03.289; 95% CI, 1.156-9.359; p\xa0=\xa00.026) remained associated with all-cause mortality after adjustment. Similarly, Grades 2 and 3 AoAC (HR\xa0=\xa036.05; 95% CI, 3.494-372; p\xa0=\xa00.026) significantly correlated with CV mortality after adjustment.
Answer: In patients undergoing PD, CXR-detected severe AoAC was an independent risk factor for all-cause and CV mortalities.

Answer:
Does severe aortic arch calcification predict mortality in patients undergoing peritoneal dialysis?