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.

Context: After formation of the linear heart tube a chamber-specific program of gene expression becomes active that underlies the formation of the chamber myocardium. To assess whether this program is recapitulated in in vitro differentiated embryonic stem cells, we performed qualitative and quantitative analyses of cardiogenesis in vivo and in vitro.', 'Gene expression profiles were made by in situ hybridisation and real-time PCR and electrophysiological profiles by patch clamp analyses of cardiomyocytes derived from time series of differentiating HM1 mouse embryonic stem cells and from embryonic and adult mouse hearts.', 'In embryoid bodies the in situ patterns of expression of alpha-myosin heavy chain, myosin light chain 2a and sarcoendoplasmic reticulum calcium ATPase 2a were similar to that of the heart muscle-specific marker gene cardiac troponin I. Myosin light chain 2v was expressed in part of the cardiac troponin I-expressing area, indicating heterogeneity within the cardiac cell population. Atrial natriuretic factor expression, indicative of the chamber-type program, could only very occasionally be detected by in situ hybridisation. Quantitative reverse transcriptase PCR showed that all cardiac genes, most notably atrial natriuretic factor, were expressed at relatively low levels, similar to those in embryonic hearts at embryonic day 8.75-9. Analysis of the electrophysiological characteristics of embryonic stem cell-derived cardiomyocytes showed an increase of the upstroke velocity and a shorter duration of the action potential during prolonged differentiation in vitro. When embryonic mouse heart compartments of embryonic day 12.5 were used as a reference, the electrophysiological characteristics of a substantial part of the embryonic stem cell-derived cardiomyocytes were most reminiscent to those observed in the embryonic outflow tract.
Answer: Together, these data suggest that most cardiomyocytes acquired by differentiation of embryonic stem cells maintain a phenotype reminiscent of that of the cardiomyocytes of the primary heart tube, and hardly any myocytes develop a chamber myocardial phenotype.
Do cardiomyocytes derived from embryonic stem cells resemble cardiomyocytes of the embryonic heart tube?

Context: We previously demonstrated in rats that intravenous infusion of a lipid emulsion increases survival in resuscitation from severe bupivacaine cardiac toxicity. The present studies were undertaken to determine if this method is similarly effective in a non-rodent model using a larger animal.', 'Bupivacaine, 10 mg/kg, was administered intravenously over 10 seconds to fasted dogs under isoflurane general anesthesia. Resuscitation included 10 minutes of internal cardiac massage followed with either saline or 20% lipid infusion, administered as a 4-mL/kg bolus followed by continuous infusion at 0.5 mL/kg/min for 10 minutes. Electrocardiogram (EKG), arterial blood pressure (BP), and myocardial pH (pHm) and pO2 (pmO2) were continuously measured.', 'Survival after 10 minutes of unsuccessful cardiac massage was successful for all lipid-treated dogs (n = 6), but with no survivors in the saline controls (n = 6) (P <.01). Hemodynamics, PmO2, and pHm were improved during resuscitation with lipid compared with saline treatment in which dogs did not recover.
Answer: We found that infusing a lipid emulsion during resuscitation from bupivacaine-induced cardiac toxicity substantially improved hemodynamics, pmO2, and pHm and increased survival in dogs.
Does lipid emulsion infusion rescue dogs from bupivacaine-induced cardiac toxicity?

Context: Our previous reports demonstrated that genetic deletion of μ-opioid receptor has no influence on the anaesthetic and antinociceptive effects of nitrous oxide (N2O) in mice, and that an antagonist selective for κ-opioid receptor (KOP), but not that selective for δ-opioid receptor, suppresses the antinociceptive effect of N2O. However, it is not known whether genetic deletion of KOP affects the N2O actions.', 'We measured the minimum alveolar concentration (MAC) of volatile anaesthetics in the absence and presence of N2O. The antinociceptive action of N2O was tested by an acetic acid-writhing test and a hot-plate test. The number of c-Fos-immunopositive cells in sections from the lumbar spinal cord was counted to test whether the descending inhibitory system participates in the pharmacological action of N2O. The hypnotic action of N2O was assessed by measuring the N2O-induced decrease in the EC50 for loss of the righting reflex (EC50-LORR) of sevoflurane.', 'Sevoflurane MAC was not significantly reduced by N2O and its antinociceptive action was almost completely abolished in KOP-knockout (KO) mice. The N2O-induced increase in c-Fos-immunopositive cells in laminae III-IV of the lumbar spinal cord was significant in wild-type (WT), but not in KOP-KO mice. In contrast, sevoflurane EC50-LORR was similarly reduced by N2O in WT and KOP-KO mice.
Answer: Our study suggests that N2O demonstrates its antinociceptive action and reduces sevoflurane MAC in mice through KOP activation, whereas its hypnotic potency is not dependent on KOP activation.

Does κ-Opioid receptor mediate the antinociceptive effect of nitrous oxide in mice?