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: 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.

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


Question: Context: Recently, the Arg389Gly beta1-adrenoceptor (beta1AR) gene polymorphism has been detected. The Arg variant exhibited increased responsiveness to agonist-induced stimulation in vitro. Functional studies in isolated human atrial muscle strips and in-vivo studies revealed contradictory results regarding the functional relevance of this polymorphism. We sought to characterize the functional consequences of the Arg389Gly beta1-AR polymorphism in 30 consecutive healthy male volunteers in vivo.', 'beta1-AR genotype was determined by PCR and restriction analysis, which was confirmed by DNA sequencing. We compared heart rate, blood pressure, and contractile response of the various genotype carriers with a modified dobutamine stress echocardiography protocol.', 'Subjects homozygous for the Arg389 beta1AR showed a significantly higher increase in fractional shortening upon cumulative doses of dobutamine as compared to subjects carrying one or two copies of the Gly389 allele. A statistically significant difference was observed at a dobutamine dose of 10 microg/kg/min (46.5 +/- 1.3 vs. 41.8 +/- 1.0 %; P = 0.023) and was maximal at 40 microg/kg/min (61.9 +/- 1.4 vs. 52.8 +/- 1.6; P = 0.001). As a result, the systolic blood pressure response to dobutamine was significantly enhanced in individuals homozygous for the Arg389 allele, whereas the effect on heart rate did not differ between the two groups. Normalization for changing afterload conditions by calculating the pressure-dimension ratio revealed similar effects, indicating that the beta1AR-mediated effects are mainly a result of increased myocardial inotropy.
Answer: These data indicate that the Arg389Gly beta1AR polymorphism is functionally relevant in vivo and determines contractile responsiveness to catecholamines in humans.

Answer: Does the Arg389Gly beta1-adrenoceptor gene polymorphism determine contractile response to catecholamines?


Question: Context: Few studies investigated the best method for removing stains from different types of resin-based composite restorations and compared them to the more recently introduced nanocomposites. This study compared the effect of four methods for stain removal from composite resins; finishing with Sof-lex disks, using pumice and brush, bleaching with 10% carbamide peroxide and 38% hydrogen peroxide.', 'Twenty disk specimens were prepared. Specimens were immersed in a staining solution for 3\xa0weeks. The stained surfaces of five specimens from each RBC material were treated with one of the treatment procedures. Colorimetric measurements were taken using spectrophotometer prior to and after staining, and then repeated after surface treatments. Color difference values were calculated.', "One-way ANOVA indicated significant differences in color change of the three composite resin materials following staining. Filtek Z250 showed the least susceptibility to discoloration followed by Renamel, Filtek Supreme was the material most prone to discoloration. Two-way ANOVA and Tukey's Post Hoc showed that all stain removing procedures except polishing with pumice, were able to return Filtek Z250 to clinically acceptable color difference. While bleaching with 38% carbamide peroxide was not effective with Renamel. Only pumice and 10% carbamide peroxide were able to return Renamel to clinically acceptable color difference.
Answer: Compositions of resin-based composite resins play an important role in their susceptibility to stain and their amenability to stain removal procedures. Home bleaching showed good results for the three materials, while office bleach was the least effective.

Answer:
Do the effectiveness of four methods for stain removal from direct resin-based composite restorative materials?