TASK DEFINITION: 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.
PROBLEM: Context: Chronic HIV/HCV co-infection carries increased risk of cirrhosis, hepatocellular carcinoma, and death. Due to anti-inflammatory properties, HMG co-A inhibitors (statins) may be useful adjunctive therapy to reduce liver disease progression.', 'Clinical information was extracted from the Veterans Affairs HIV and HCV Clinical Case Registries (1999 - 2010). HIV-related variables included combination anti-retroviral therapy (cART) era of diagnosis, CD4 cell count, and percent time with undetectable HIV viral load. Metabolic variables included diabetes, low-HDL, and hypertension. Statin use was measured as percent time with active prescription (time-updated throughout the follow-up period). Cox proportional hazards analysis was used to determine risk factors for cirrhosis (ICD-9 or APRI>2) overall and in groups stratified by alanine aminotransferase (ALT) level above and below 40\u200aIU/L.', 'The cohort included 5985\u200aHIV/HCV co-infected veterans. The majority was black race, and the mean age at index date was 45 years. Statin use was significantly protective of cirrhosis for patients with ALT ≤40\u200aIU/L; for every 30% increase in time on statin, there was a 32% decreased risk of developing cirrhosis (HR 0.68, 95% CI 0.47 -0.98). Diabetes and low-HDL were significantly associated with cirrhosis in patients with ALT > 40\u200aIU/L (HR 1.15, p\u200a<\u200a0.04 and HR 1.3, p\u200a<\u200a0.0001).
Answer: Statin drug use is beneficial in mitigating the risk of liver disease progression for HIV/HCV co-infected patients without advanced liver disease. Low-HDL and diabetes in co-infected patients with abnormal ALT have greater risk of cirrhosis development.

SOLUTION: Do statin drugs decrease progression to cirrhosis in HIV/HCV co-infected individuals?

PROBLEM: Context: To investigate a putative increased risk of rectal cancer subsequent to prostatic radiotherapy.', 'In an analysis of the Surveillance, Epidemiology, and End Results registry, we compared men who had radiotherapy for prostatic carcinoma with those treated surgically and those treated with neither modality. Kaplan-Meier analyses for the time to failure from rectal cancer were performed between age-matched subgroups of the three cohorts. Cox proportional hazards analyses were performed to ascertain what influences might affect the incidence of subsequent rectal cancer.', 'In all, 33,831 men were irradiated, 167,607 were treated surgically, and 36,335 received neither modality. Rectal cancers developed in 243 (0.7%) of those irradiated (mean age, 70.7 years), 578 (0.3%) of those treated surgically (68.7 years), and 227 (0.8%) of those treated with neither modality (74.2 years). When age effects and the differences between the surgical and untreated cohorts were controlled for, we were unable to demonstrate any significant increased incidence of rectal cancer in men irradiated for prostatic cancer.
Answer: An increased frequency of rectal cancer after prostatic irradiation, apparent on crude analysis, could be attributed to age confounding and other unmeasured confounders associated with prostate cancer treatment and rectal cancer risk.

SOLUTION: Is prostatic irradiation associated with any measurable increase in the risk of subsequent rectal cancer?

PROBLEM: Context: The incidence of hydronephrosis due to ureteropelvic junction obstruction is approx. 0.5%. During the last decade, the management of non-symptomatic hydronephrosis has become much more conservative, but the long-term physiological consequences of this policy are not clear. Previously, we have shown that animals with chronic partial unilateral ureteral obstruction develop salt-sensitive hypertension. In this study, the effects of ipsilateral and contralateral nephrectomy and ureterovesicostomy on blood pressure were studied in hydronephrotic animals.', 'Partial unilateral ureteral obstruction was created in 3-week-old male Sprague-Dawley rats and blood pressure was measured telemetrically 4-6 weeks later during a normal and high salt diet before and after uninephrectomy or ureterovesicostomy. Plasma samples for renin assay were collected during both diets before and after ipsilateral nephrectomy.', 'All hydronephrotic animals developed salt-sensitive hypertension, of different degrees. Before nephrectomy the plasma renin concentration was significantly higher in the hydronephrotic animals than in controls (160 +/- 15 microGU mL(-1) vs. 96 +/- 12 microGU mL(-1), respectively), but after the ipsilateral nephrectomy no differences were found between the groups. In the hydronephrotic animals both ipsilateral nephrectomy and ureterovesicostomy reduced the blood pressure and salt-sensitivity but the former still differed significantly from the controls. In contralaterally, nephrectomized hydronephrotic animals the salt-sensitive hypertension became more pronounced.
Answer: Hydronephrosis in rats causes salt-sensitive hypertension that can be markedly reduced by removing the hydronephrotic kidney or relieving the obstruction by ureterovesicostomy. The mechanisms appear to be intrarenal and primarily located in the diseased kidney, but a secondary mechanism is also present.

SOLUTION:
Does relief of chronic partial ureteral obstruction attenuate salt-sensitive hypertension in rats?