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.

Example Input: The biliary cast syndrome (BCS) is a frequent problem following liver transplantation. The pathogenesis of this complication is not well understood. Previous research has demonstrated that the soluble form of MICA (sMICA) is significantly higher in patients with chronic liver disease and hepatocellular carcinoma (HCC) than in healthy volunteers. The aim of this study is to investigate the possible involvement of sMICA in the formation of BCS after liver transplantation.', 'Serum soluble MICA was retrospectively evaluated in pre- and post-transplant sera from 133 consecutive primary liver transplant patients and in sera from 88 healthy volunteers using sandwich ELISA. Normal distribution of serum sMICA was described by the data obtained from healthy population and sMICA concentration that was greater than the upper bound 95% normal range was considered as high levels of sMICA. Patient records were reviewed to identify patients who developed BCS.', 'The results demonstrated that 37.6% of patients with end-stage liver diseases had significantly higher pre-transplant serum sMICA than in healthy population. 34.4% of recipients with post-transplant high levels of sMICA developed BCS. In contrast, 17.3% of patients with post-transplant normal levels of sMICA developed BCS. The risk of BCS development is significantly associated with the presence of post-transplant high levels of sMICA (P=0.0365). Further analysis disclosed that patients with decreased post-transplant sMICA following liver transplantation had a lower incidence rate of BCS than those with remained high levels of sMICA after transplantation (10.5% vs. 38.7%, P=0.0302). Furthermore, log-rank test showed that BCS occurrence was significantly associated with dynamic changes of sMICA among different groups (P=0.0188).
Example Output: Are high levels of soluble Major Histocompatibility Complex class I related chain A ( MICA ) associated with biliary cast syndrome after liver transplantation?

Example Input: Studies performed in Andean populations living in high altitude, indicate that the reduced availability of oxygen could be associated to both a fetal growth retardation and a lower birth weight. These variables are predictive of morbidity and mortality during the first year of life.', 'To study perinatal variables of newborns of mothers living at contrasting altitudinal levels, harboring different degrees of Aymara ancestry.', 'Review of medical records of 5,295 women whose deliveries occurred between February 2004 and August 2010. Information was obtained on place of residence, grouped into two categories: coast (150 to 3,000 m) and high plateau (3,000 to 4,300 m), ancestry was estimated using number of Aymara surnames that were homologated to percentages of Amerindian admixture, gestational age, birth weight, height, head circumference and obstetric variables.', 'Gestational age showed a tendency to increase and birth weight, height and head circumference to decrease with altitude of residence. Only weight reached statistical significance. Women with Aymara ancestry gave birth to children with a significantly higher gestational age, weight and cranial circumference.
Example Output: Do [ Perinatal variables from newborns of Aymara mothers suggest a genetic adaptation to high altitude ]?

Example Input: High sodium intake is implicated in contributing to progression of chronic renal failure. We studied the effect of high sodium consumption on progression of rat experimental renal failure while sodium-induced hypertension was pharmacologically controlled.', '64 Sprague-Dawley rats underwent 5/6 nephrectomy. Subsequently, they were divided in three groups which were fed either low, normal, or high sodium diet. Only the high sodium-consuming group developed hypertension. This group was further divided in two subgroups in which hypertension was either untreated or titrated to normotension by hydralazine alone or with propranolol.', 'Sequential GFR values did not differ between the respective normotensive groups. Survival downslopes of all three normotensive groups (including the pharmacologically treated, high sodium-consuming subgroup) were also similar, extending over 10 weeks. By contrast, pharmacologically untreated animals exhibited severe hypertension and 100% mortality within 3 weeks. In all experimental groups, 24-hour urinary sodium excretion paralleled sodium intake. Proteinuria rose similarly and significantly in all animals on high sodium. A significant correlation between 24-hour sodium and proteinuria was evident throughout the experimental period.
Example Output:
Does hypertension but not sodium intake determine progression of renal failure in experimentally uremic rats?