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?
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Q: 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.

A: Do human immunodeficiency virus and hepatitis C infections induce distinct immunologic imprints in peripheral mononuclear cells?
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Q: Context: The aim was to review different approaches for the derivation of threshold values and to discuss their strengths and limitations in the context of minimum provider volumes.', "The following methods for the calculation of threshold values are compared and discussed: The value of acceptable risk limit, the value of acceptable risk gradient, the benchmark value proposed by Budtz-Jørgensen and Ulm's breakpoint model. The latter is extended to account for two different breakpoints. The methods are applied to German quality assurance data concerning total knee replacement.", 'The discussed methods for calculating threshold values differ in the kind of information that has to be specified beforehand. For the value of acceptable risk limit approach an absolute number, the acceptable risk, has to be predetermined. The value of acceptable risk gradient approach and the method of Budtz-Jørgensen require the specification of a relative change expressed in gradient and in odds, respectively. On the other hand, the threshold value according to the method of Ulm is defined as a parameter of a statistical model and no a priori specification is required.
Answer: Each of the proposed methods has benefits and drawbacks. The choice of the most appropriate approach depends on the specific problem and the available data.

A:
Are flexible regression models useful tools to calculate and assess threshold values in the context of minimum provider volumes?
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