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: Progenitor cells isolated from cardiac explant-derived cells improve cardiac function after myocardial infarction (MI). To fully realize the therapeutic potential of these cells, it is essential to develop a safe and efficient delivery method. Therefore, the objective of this study was to determine the efficacy of our newly developed approach to retrograde coronary vein (RCV) infusion of cardiac c-Kit(+) cells in a small-animal model of congestive heart failure (CHF).', 'Sprague-Dawley rats underwent experimental MI. After 21 days, cardiac explant-derived c-Kit(+) cells were delivered to both sham and CHF animals using RCV delivery. Vehicle-treated (serum-free medium) sham and CHF animals were used as controls. Cardiac function and heart tissues were evaluated 21 days post-transplantation.', 'RCV-delivered cells were retained in infarcted hearts for at least 21 days after transplantation. At 21 days post-RCV infusion, the majority of transplanted c-Kit(+)/GFP(+) cells were localized in the left ventricle. Compared with vehicle-treated CHF animals, RCV-treated rats showed a significant improvement in cardiac function. Furthermore, RCV-treated rats exhibited an increase in capillary density, a decrease in total heart collagen, and a reduction in both infarct size and cardiomyocyte hypertrophy when compared with vehicle-treated CHF rats.
Answer: Our study showed that the RCV infusion approach is an efficient technique for targeted cell delivery to the infarcted myocardium. Cardiac c-Kit(+) cells, delivered using RCV infusion ameliorated progression of heart failure, improved cardiac function and retarded myocardial remodeling in heart failure rats.
[EX A]: Does retrograde coronary vein infusion of cardiac explant-derived c-Kit+ cells improves function in ischemic heart failure?

[EX Q]: Context: Cross-sectional, clinical measurement.', 'To investigate the validity of the Duruoz Hand Index (DHI) in the assessment of hand function in patients with tetraplegia.', "A total of 40 patients with tetraplegia participated. Patients' upper extremities were assessed on the level of 'body function and structure' [The American Spinal Cord Injury Association (ASIA) Impairment Scale (AIS) 2000 revised criteria, upper extremity motor score (UEMS), neurologic level of injury and visual analogue scale of hand function (VAS-HF)], 'activity' [DHI and Quadriplegia index of function-short form (QIF-SF)] and 'body function and structure, activity and participation' [Health Survey Short Form-36 (SF-36)] according to International Classification of Function.", 'The DHI showed significant correlations with UEMS, AIS, QIF-SF, VAS-HF, physical functioning and physical compound summary scores of SF-36.
Answer: The DHI was found a valid method in the assessment of hand functions in patients with tetraplegia.
[EX A]: Do validation of Duruoz Hand Index in patients with tetraplegia?

[EX Q]: Context: Programmed cell death (apoptosis) has been implicated in tumor development and may affect the metastatic potential of tumor cells. The role of bcl-2, a proto-oncogene that inhibits apoptosis, has been studied in several malignancies, including cutaneous melanoma (CM). The purpose of this study was to evaluate the immunohistochemical expression of bcl-2 in 35 regional lymph node, 28 subcutaneous and 17 visceral CM metastases, correlating the findings with patient survival.', 'In a historical cohort study patient survival was correlated with the expression of bcl-2 in regional lymph node, subcutaneous and visceral metastases of CM. Eighty slides containing surgical specimens from 50 patients diagnosed with stage III and IV CM, 28 male (56%) and 22 female (44%), were analyzed. Mean age at diagnosis was 43 years (16-74 years; median = 42 years). Mean Breslow depth was 5.01 mm (0.4-27.5 mm). The slides were submitted to immunohistochemical reaction using anti-bcl-2 monoclonal antibody and classified according to the degree of staining (< 5%; 5 to 50%; or > 50% of tumor cells stained). The relationship between bcl-2 protein expression and survival for each type of metastasis, gender and age at initial diagnosis was analyzed.', 'Mean overall survival was 33.9 months after the diagnosis of the initial metastatic lesion (range: 0 to 131 months). Twenty-four out of 50 patients (48%) had died from CM by the end of the study period. bcl-2 expression was detected in 74.3, 85.7 and 82.4% of lymph node, subcutaneous and visceral metastases, respectively. After univariate and multivariate analyses, no correlation was found between positive bcl-2 expression and overall survival for the types of metastases evaluated.
Answer: The immunohistochemical expression of bcl-2 in metastasis alone is not a prognostic marker for CM.
[EX A]:
Is bcl-2 expression associated with survival in metastatic cutaneous melanoma : a historical cohort study?