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: The aim of this study was to investigate the relationship between intraoperative vasopressin infusion and postoperative cardiac enzymes.', 'A prospective, double-blind, randomized, controlled study.', 'A single tertiary cardiac center.', 'One hundred consecutive patients undergoing cardiac surgery with or without cardiopulmonary bypass.', 'The study was approved by the Institutional Review Board, and patients provided informed consent to participate. Patients were randomized by computer into 2 equal groups: Vasopressin or control. The blinded study included vasopressin administered at a dose of 1.8 U/h or 1.8 mL/h of normal saline, along with catecholamines. The drug was administered continually during surgery while patients needed catecholamines. The intervention was discontinued upon admission to the intensive care unit when information regarding the true character of the drug was reported to the doctor in charge of patients in the intensive care unit by one of the investigators. Primary outcomes were CK-MB and troponin T levels measured at 0, 6, and 12 hours postoperatively.', 'Of the 100 patients, 8 were excluded; the remaining 92 were randomized to either the vasopressin (n = 47) or control (n = 45) group. There were no significant differences in demographic data between the groups. Postoperatively at 0, 6, and 12 hours, there were no differences in CK-MB (U/l) (37.5 57.9 v 32.0 21.5, 29.4 41.1 v 24.4 23.1, and 21.4 21.3 v. 21.8 32.4, respectively) and troponin T (752.4 638.2 v 762.7 557.1, 753.8 507.3 v 777.6 515.0, and 774.6 572.6 v 698.7 540.2, respectively) values.
Answer: Vasopressin infusion has been used to treat catecholamine-unresponsive shock. In this study, intraoperative vasopressin was used safely as a possible first-line drug for treating hypotension; however, it did not increase the levels of cardiac enzymes after cardiac surgery.
[A]: Does vasopressin raise cardiac enzymes following cardiac surgery : a randomized double-blind clinical trial?

[Q]: Context: Observational and clinical studies suggest different responses upon sex hormone replacement therapy in ischaemic heart disease. Few studies, however, have examined the impact of oestrogen receptor-dependent mechanisms on the extent of injury after myocardial infarction (MI). Therefore, we set out to evaluate the effect of oestrogen (E2) replacement on infarct size and remodelling, and the respective role of the oestrogen receptors (ER)alpha and -beta in this process, using ERalpha- and ERbeta-deficient mice.', 'Wild type (WT) (ERalpha(+/+) and ERbeta(+/+)), ERalpha-deficient (ERalpha(-/-)) and ERbeta-deficient (ERbeta(-/-)) mice were ovariectomized and subsequently supplemented with E2 or placebo using subcutaneous 60-day release pellets. MI was induced by left coronary artery ligation. Two weeks following MI, haemodynamic function was assessed and infarct size was determined.', 'There was no significant difference in infarct size between E2- or placebo-treated WT (ERalpha(+/+) and ERbeta(+/+)) mice. Surprisingly, E2 treatment did result in smaller infarct sizes in ERalpha(-/-) mice, but increased the infarct size in ERbeta(-/-) mice. Increase of the left ventricular mass post-MI was significantly larger in the E2-treated ERalpha(-/-) animals compared with placebo-treated animals. E2 treatment also significantly increased post-MI mortality in ERalpha(+/+), ERbeta(+/+) and ERalpha(-/-) animals, but not in ERbeta(-/-) mice.
Answer: Although E2 modulates the infarct size in ERalpha(-/-), it also appears to be responsible for the higher mortality following MI. ERbeta appears to be the receptor involved in the modulating effects of E2 in the infarcted heart.
[A]: Does oestrogen modulate cardiac ischaemic remodelling through oestrogen receptor-specific mechanisms?

[Q]: Context: The prognostic significance of cell proliferation, estimated as cytometric S-phase fraction (SPF), was investigated in node-negative breast cancer patients with small tumors (T1, NO). The 219 stage I patients originated from two series and were diagnosed either from 1978 to 1981 or from 1981 to 1985. The tumors were analyzed for estrogen receptors (ERs) by isoelectric focusing and for cellular DNA content by static cytofluorometry or flow cytometry.', 'A high SPF correlated with the absence of ERs and abnormal DNA content, and was less often found in tumors smaller than 11 mm compared with those with a diameter between 11 and 20 mm. Among the variables age, tumor size, DNA ploidy, ER status, and SPF, only SPF showed a significant association with distant recurrence and breast cancer survival in systemically untreated patients. The relative recurrence rate for patients with an SPF of 10% or greater was three times that for patients with lower SPFs. Estimated 8-year breast cancer survival rates for the same groups were 72% and 91%, respectively.
Answer: This study suggests that cytometric SPF has prognostic significance in stage I breast carcinoma.
[A]:
Is s-phase fraction a prognostic factor in stage I breast carcinoma?