Given a passage, 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: Class III antiarrhythmic agents exhibit reverse rate-dependent lengthening of the action potential duration (APD). In spite of the several theories developed so far to explain this reverse rate dependency (RRD), its mechanism has not yet been clarified. The aim of the present work was to further elucidate the mechanisms responsible for reverse rate-dependent drug effects.', 'Action potentials were recorded from multicellular canine ventricular preparations and isolated cardiomyocytes, at cycle lengths (CLs) varying from 0.3 to 5 s, using conventional sharp microelectrodes. APD was either modified by applying inward and outward current pulses, or by superfusion of agents known to lengthen and shorten APD. Net membrane current (I(m)) was calculated from action potential waveforms. The hypothesis that RRD may be implicit in the relationship between I(m) and APD was tested by numerical modelling. Both drug-induced lengthening (by veratrine, BAY-K 8644, dofetilide, and BaCl(2)) and shortening (by lidocaine and nicorandil) of action potentials displayed RRD, i.e. changes in APD were greater at longer than at shorter CL. A similar dependency of effect on CL was found when repolarization was modified by injection of inward or outward current pulses. I(m) measured at various points during repolarization was inversely proportional to APD and to CL. Model simulations showed that RRD is expected as a consequence of the non-linearity of the relationship between I(m) and APD.

A: Is reverse rate dependency an intrinsic property of canine cardiac preparations?
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Q: To investigate the inhibition of amyloid beta-protein 42 (Abeta42) production in M146L cells by gamma-schisandrin.', 'M146L cells which can produce considerable Abeta42 in vitro were treated with gamma-schisandrin (1.67, 5.00 and 15.00 microg x mL(-1)), beta-secretase inhibitor (S4562, 100.00 microg x mL(-1)) and gamma-secretase inhibitor (S2188, 13.68 microg x mL(-1)), separately. Cell counting kit-8 (CCK-8) was used to assess cell viability. Enzyme-linked immunosorbent assay (ELISA) was carried out to determine the amount of Abeta42. Western blotting was used to examine C99, an intermediary product of APP cleaved by beta-secretase. beta-Secretase and gamma-secretase activities were assayed by commercial kits.', 'The CCK-8 assay indicated that different concentrations of gamma-schisandrin had no neurotoxicity on the cultured M146L. And the ELISA test showed that the amount of Abeta42 secreted by M146L cells treated with gamma-schisandrin (5.00 and 15.00 microg x mL(-1)) decreased obviously as compared with solvent control. The results of Western blotting test indicated that there was no change of C99 contents and beta-secretase activity in gamma-schisandrin treated cells, while gamma-secretase activity decreased obviously.

A: Does [ Gamma-Schisandrin inhibit production of amyloid beta-protein 42 in M146L cells ]?
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Q: Management of cardiac surgery patients is a very standardized procedure in respective local institutions. Yet only very limited evidence exists concerning optimal indication, safety and efficacy of hemodynamic monitoring catecholamine and fluid therapy.', 'Between April and May 2013, all 81 German anaesthesia departments involved in cardiac surgery care were asked to participate in a questionnaire addressing the institutional specific current practice in hemodynamic monitoring, catecholamine and volume therapy.', '51 (63%) questionnaires were completed and returned. All participating centers used basic hemodynamic monitoring (i.e. invasive arterial blood pressure and central venous pressure), supplemented by transesophageal echocardiography. Pulmonary arterial catheter and calibrated trend monitoring devices were also routinely available. In contrast, non-calibrated trend monitoring and esophageal doppler ultrasound devices were not commonly in use. Cerebral oximetry is increasingly emerging, but lacks clear indications. The majority of patients undergoing cardiac surgery, especially in university hospitals, required catecholamines during perioperative care, In case of low cardiac output syndrome, dobutamine (32%), epinephrine (30%) or phosphodiesterase inhibitors (8%) were first choice. In case of hypotension following vasoplegia, norepinephrine (96%) represented the most common catecholamine. 88% of the participating centers reported regular use of colloid fluids, with hydroxyethyl starches (HES) being first choice (64%).

A:
Does catecholamine and volume therapy for cardiac surgery in Germany -- result from a postal survey?
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