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.

[EX Q]: Context: To assess, in a retrospective cohort, urinary tract urothelial carcinoma (UT-UC) in patients with various stages of chronic kidney disease (CKD) and their clinicopathological features, as patients with end-stage renal disease (ESRD) have a higher incidence of UT-UC, but the relationship between early stages of CKD and characteristics of UT-UC are less well known.', 'The study included 267 patients with pathologically confirmed UT-UC from January 1994 to December 2006; all had a physical examination (blood pressure), and measurements of laboratory data (serum creatinine, serum haemoglobin) and pathological data. The glomerular filtration rate (GFR) was calculated using the Modification of Diet in Renal Disease equation. Patients were divided into three groups by individual GFR (mL/min), i.e. >60 (no/mild CKD), 30-60 (CKD stage 3) and <30 (CKD stage 4/5).', 'The CKD stages included 81 (30.3%) patients with none/mild CKD, 121 (45.3%) with CKD stage 3 and 65 (24.3%) with CKD stage 4/5. There was a significant and parallel increase in the frequency of UT-UC as CKD severity increased from none/mild CKD to stage 3 (11% vs 55%), and from CKD stage 3 to 4/5 (55% vs 71%; P < 0.05). Pathologically, the frequency of high-grade and high T stage UT-UC in patients with CKD stage 3 (90% and 35%, respectively) and CKD stage 4/5 (91% and 29%, respectively) were significantly greater than in the group with none/mild CKD (P < 0.001). Advanced age and more distant metastasis were independent risk factors for patient survival.
Answer: The aggressiveness of UT-UC increased with the severity of CKD, and this might have important clinical consequences.
[EX A]: Does the aggressiveness of urinary tract urothelial carcinoma increase with the severity of chronic kidney disease?

[EX Q]: Context: Cardiac resynchronization therapy (CRT) by simultaneous biventricular pacing is now widely accepted as a new therapeutic option for patients with severe congestive heart failure (CHF). Recent studies have shown comparable hemodynamic benefits of left ventricular (LV) pacing alone. The clinical usefulness of CRT, however, might be compromised by potential exaggeration of arrhythmogenic substrates through a modification of ventricular repolarization.', 'We compared ECG parameters during sinus rhythm (SR), atrioventricular synchronous pacing at the right ventricular apex (RV(end)P), at LV epicardium (LV(epi)P), and at both sites (BiVP) in acute homodynamic studies of 14 CHF patients scheduled for CRT (QRS duration = 144 +/- 23 msec, LVEF = 27 +/- 10%). The maximum rate of increase in LV pressure (LVdp/dt(max)) was decreased significantly during RV(end)P, whereas it was increased similarly during LV(epi)P and BiVP compared with SR. QTc was increased during RV(end)P (by 10.2%) and LV(epi)P (by 26.1%). QTc dispersion (QTc(max)-QTc(min) in the six precordial leads) was also increased during LV(epi)P (by 66.5%). These parameters were unaffected during BiVP. JTc was unchanged, and the interval from the peak to the end of the T wave (Tc(peak-end)) was increased slightly (by 19.3%) during RV(end)P. Both JTc and Tc(peak-end) were increased dramatically during LV(epi)P (by 18.2% and 55.4%, respectively), but increased only modestly during BiVP (by 6.6% and 15.8%, respectively).
Answer: LV(epi)P causes much greater increase in spatial dispersion of ventricular repolarization than BiVP in CHF patients. BiVP may have a substantial advantage over LV(epi)P to minimize the proarrhythmic perturbation of ventricular repolarization in association with CRT.
[EX A]: Does biventricular pacing have an advantage over left ventricular epicardial pacing alone to minimize proarrhythmic perturbation of repolarization?

[EX Q]: Context: Differences in mortality are thought to exist between African Americans and Caucasians with heart failure. These differences may be due to a variety of factors, including differences in disease process, socioeconomic status, and access to health care. Additionally, little data exist on racial differences between these two groups after cardiac transplantation. This study examines a single center, urban experience in treating African Americans and Caucasians with heart failure and after cardiac transplantation. We hypothesize that treatment in a specialized, comprehensive heart failure/cardiac transplantation program results in similar survival between African Americans and Caucasians.', 'We retrospectively reviewed the Rush Heart Failure and Cardiac Transplant Database from July 1994 to August 2000. Variables analyzed in the cardiomyopathy patients included survival (until death, placement of left ventricular assist device or cardiac transplantation), number of hospitalizations per year, length of stay per year, and utilization of outpatient resources. Follow-up period was from initial visit to death, transplantation, or implantation of left ventricular assist device. In those who underwent cardiac transplantation, we examined rejection rates (cellular and humoral), rejection burden, hospitalization data, and 5-year survival. A subgroup bridged to cardiac transplantation with a left ventricular device was also analyzed.', 'Seven hundred thirty-four cardiomyopathy patients were identified: 203 were African Americans and 531 were Caucasians. The etiology of cardiomyopathy was more commonly ischemic in Caucasians as compared to non-ischemic in African Americans (P <.01). African Americans had more admissions to the hospital per year compared with Caucasians, 1.2 +/- 2.1 versus.5 +/- 1.1 (P <.01) with longer length of stay per year, 1.4 +/- 25.2 days versus 4.4 +/- 14.3 days (P <.01). Utilization of outpatient resources was significantly higher in African Americans compared with Caucasians with more use of continuous inotropes (13% versus 6%, P <.01), intermittent inotropes (11% versus 5%, P <.01), and home nursing after hospital discharge (52% versus 32% of hospital discharges, P <.01). Survival by Kaplan-Meier analysis was comparable between the two groups (mean survival 1,470 +/- 72 days in African Americans versus 1521 +/- 46 days in Caucasians, log rank test [P =.6]). During this time, 30 African Americans and 73 Caucasians underwent cardiac transplantation. Fifty-three were bridged to transplantation with a left ventricular assist device (20 African Americans, 33 Caucasians). There were no differences in 5-year survival by Kaplan-Meier analysis despite higher peak preoperative panel reactive antibody levels in African Americans versus Caucasians (12% +/- 30% compared with 5% +/- 15%, P =.04), more overall treated rejection episodes per year in the African Americans (P <.01), as well as more posttransplant hospitalizations (2.2 +/- 1.2 times per year as compared with 1.7 +/- 2.1 times per year, P =.04).
Answer: Delivery of care to heart failure patients in a comprehensive, specialized program results in similar survival regardless of race despite higher utilization of inpatient and outpatient resources. The finding that, after cardiac transplantation, African Americans do not have higher mortality rates, despite having higher rates of rejection overall and more hospitalizations, further supports the hypothesis that optimal care can improve outcomes despite unfavorable baseline clinical characteristics.
[EX A]:
Are influence of race in heart failure and cardiac transplantation : mortality differences eliminated by specialized , comprehensive care?