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.

Context: Coinfection with hepatitis C virus (HCV) is present in one-third of all human immunodeficiency virus (HIV)-infected individuals in the United States and is associated with rapid progression of liver fibrosis and poor response to pegylated interferon (IFN) and ribavirin. In this study we examined gene expression profiles in peripheral blood mononuclear cells (PBMCs) from different groups of individuals who are monoinfected or coinfected with HIV and HCV. Data showed that HIV and HCV viremia up-regulate genes associated with immune activation and immunoregulatory pathways. HCV viremia is also associated with abnormalities in all peripheral immune cells, suggesting a global effect of HCV on the immune system. Interferon-alpha-induced genes were expressed at a higher level in PBMCs from HIV-infected individuals. HCV and HIV infections leave distinct profiles or gene expression of immune activation in PBMCs. HIV viremia induces an immune activated state; by comparison, HCV infection induces immunoregulatory and proinflammatory pathways that may contribute to progression of liver fibrosis.
Answer: An aberrant type-I IFN response seen exclusively in HIV-infected individuals could be responsible for the poor therapeutic response experienced by HIV/HCV coinfected individuals receiving interferon-alpha-based current standard of care.
Do human immunodeficiency virus and hepatitis C infections induce distinct immunologic imprints in peripheral mononuclear cells?

Context: Stat6 signaling is active in cancer cells and IL-4-induced Stat6 activities or Stat6 activational phenotypes vary among cancer cells. This study aimed at investigating possible mechanism(s) involved in the formation of varying Stat6 activities/phenotypes.', "Stat6 regulatory genes, SOCS-1 and SHP-1, were examined for mRNA expression using RT-PCR, and their promoter DNA methylation was assayed by methylation-specific PCR in Stat6-phenotyped colon cancer cell lines. DNA methylation was then verified by sequencing. RT-PCR assay and Western blotting were used to detect the expression of SOCS-1 and SHP-1 after demethylation using 5-aza-2'-deoxycytidine.", "Compared with Stat6(null) Caco-2 cells, Stat6(high) HT-29 cells showed decreased constitutive expression of SOCS-1 and SHP-1, which correlated with DNA hypermethylation in these genes' promoters. Interestingly, demethylation in HT-29 cells recovered the constitutive expression of SOCS-1 and SHP-1.
Answer: These findings suggest that DNA methylation controls the constitutive expression of negative Stat6 regulatory genes, which may affect Stat6 activities.
Does dNA methylation regulate constitutive expression of Stat6 regulatory genes SOCS-1 and SHP-1 in colon cancer cells?

Context: The interassay variability found in the measurement of testosterone (T) levels warrants the need for laboratories to validate their methods to establish trustworthy cut-off points for diagnosis of male hypogonadism. The aims of this study were to validate measurement of total T (TT) at our laboratory in order to obtain reference ranges for TT, calculated free T (CFT), calculated bioavailable T (CBT), and salivary T (ST) in healthy young men from the Mediterranean region, and to evaluate the potential clinical value of ST by establishing its correlation with serum T.', 'An observational, cross-sectional study with sequential sampling.', 'men aged 18-30 years with body mass index (BMI)<30.', "chronic diseases, hepatic insufficiency or use of drugs altering circulating T levels. Main outcome measures TT (chemiluminescent immunoassay UniCell DXI 800 [Access T Beckman Coulter]), CFT and CBT (Vermeulen's formula), and ST (radioimmunoassay for serum TT modified for saliva [Coat-A-Count, Siemens]). Descriptive statistical analyses and correlation by Spearman's rho (SPSS 19.0 Inc., Chicago) were used.", 'One hundred and twenty-one subjects aged 24±3.6 years with BMI 24±2.5 kg/m(2) were enrolled. Hormone study: TT, 19±5.5 nmol/L (reference range [rr.] 9.7-33.3); CFT, 0.38 nmol/L (rr. 0.22-0.79); CBT, 9.7 nmol/L (rr. 4.9-19.2); and ST, 0.35 nmol/L (rr. 0.19-0.68). Correlation between ST and CFT was 0.46.
Answer: In men from the Mediterranean region, values of TT>9.7 nmol/L, CFT>0.22 nmol/L, and/or CBT>4.9 nmol/L make the presence of biochemical hypogonadism unlikely. According to the correlation between serum and ST, the clinical value of ST remains to be established.

Does reference range for serum and salivary testosterone in young men of Mediterranean region?