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.

[Q]: 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.
[A]: Does dNA methylation regulate constitutive expression of Stat6 regulatory genes SOCS-1 and SHP-1 in colon cancer cells?


[Q]: Context: A number of risk factors for chronic renal allograft rejection have been identified; in particular the number and severity of acute rejections, hypertension, hyperlipidemia, and insufficient immunosuppression.', 'In a retrospective case control study, all histologically confirmed cases of chronic rejection (n=45) that occurred between 1985 and 1993 among patients transplanted at Huddinge Hospital were compared with twice as many controls. Determinants such as donor age and sex, HLA-mismatch, cold ischemia time, recipient age and sex, body mass index, cause of renal disease, time undergoing dialysis, condition of blood vessels at surgery, time of onset, number of acute rejection episodes during the first 3 months, area under the serum creatinine versus time curve (AUC(Creatinine)), blood pressure, blood lipids, and cyclosporine concentrations at various times after the transplantation were also compared. Additional data were obtained from a questionnaire, concerning 79% of the cases and controls.', 'Cases and controls were similar with regard to most determinants, that is, blood pressure, blood lipids, and average cyclosporine concentrations. The main outstanding risk factor for chronic rejection was the time-averaged creatinine (AUC(Creatinine)) value between day 22 and 3 months after transplantation. The adjusted odds ratio for chronic rejection increased stepwise from 1.1 to 9.2, when AUC(Creatinine) increased from < 150 to >300 micromol/l. The number of acute rejection episodes and number of HLA-mismatches also had a significant effect on the risk of chronic rejection.
Answer: To reduce the risk of developing chronic rejection after renal transplantation acute rejection episodes during the first 3 months should be avoided as much as possible.
[A]: Is area under the serum creatinine time-curve a strong predictor of chronic renal allograft rejection?


[Q]: Context: Bilateral lower extremity venous duplex scanning for acute deep venous thrombosis (DVT) has been advocated because of the high incidence of occult contralateral leg involvement. We investigated the clinical necessity of such a policy.', 'The results from 2996 venous duplex studies performed during the past 2 years were retrospectively reviewed. A total of 1694 of these scans were performed on patients with symptoms, of whom 248 (15%) were found to have an acute DVT. Symptoms were limited to one side in 198 patients, whereas bilateral complaints were noted in 50 patients.', 'Among the patients with symptoms of acute DVT, 72 (29%) had bilateral involvement. Bilaterality was more likely in patients with bilateral symptoms than in those with only unilateral symptoms (56% vs 22%; p < 0.005). Of the patients with unilateral symptoms and bilateral DVT, all of them had either acute (80%) or acute and chronic (20%) thrombosis in the symptomatic leg. The contralateral asymptomatic limb had fewer acute and more chronic DVT (41% and 55%, respectively). No patient from the entire group admitted with symptoms had an acute DVT in the asymptomatic limb without a concomitant acute DVT in the symptomatic leg. Unilateral scanning would decrease the examination time by 21% and potentially increase total reimbursement for symptomatic venous scans by 9% compared with routine bilateral duplex scanning.
Answer: Although bilateral involvement is frequent in patients with symptoms of acute DVT, treatment in these patients is not altered by this finding. We conclude that contralateral venous scanning in patients with unilateral symptoms is not clinically indicated and that unilateral scanning would result in improved cost-efficiency for vascular laboratories.
[A]:
Is contralateral duplex scanning for deep venous thrombosis unnecessary in patients with symptoms?