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.

Input: Consider Input: Context: In dialysis patients, volume overhydration is common and is related to increased risk of cardiovascular morbidity and mortality. However, it remains unclear whether volume overload imposes those detrimental effects through endothelial dysfunction.', 'In this cross-sectional study, 81 stable patients on continuous ambulatory peritoneal dialysis in a single center were recruited. Volume status was evaluated by extracellular water, assessed by bioimpedance analysis, and normalized to individual height (nECW). Endothelial function was estimated by endothelial-dependent flow-mediated dilatation (FMD) of the brachial artery and expressed as percentage change relative to baseline diameter.', 'There were 37 male and 44 female patients (mean age 61 +/- 12 years, dialysis vintage 20 +/- 23 months). FMD in female patients was significantly higher than that in male patients (9.17% +/- 6.23% vs 6.31% +/- 5.01%, p < 0.05). FMD was negatively correlated with weight (r = -0.308, p < 0.01), body mass index (r = -0.242, p < 0.05), systolic blood pressure (r = -0.228, p < 0.05), ECW (r = -0.404, p < 0.001), and nECW (r = -0.418, p < 0.001). No correlation was found between FMD and other variables. In multiple stepwise regression analysis, calcium x phosphate product (beta = 0.422, p < 0.001), nECW (beta = -0.343, p < 0.01), and dialysis vintage (beta = -0.237, p < 0.05) were independent determinants of FMD (adjusted R(2) = 0.327 for this model).
Answer: There was independent correlation between index of volume status and FMD, and higher nECW was related to worse endothelial function. The results of this study may help us understand the underlying mechanism of volume overhydration leading to increased cardiovascular morbidity and mortality in dialysis patients.

Output: Is volume overhydration related to endothelial dysfunction in continuous ambulatory peritoneal dialysis patients?


Input: Consider Input: 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.

Output: Do cardiomyocytes derived from embryonic stem cells resemble cardiomyocytes of the embryonic heart tube?


Input: Consider Input: Context: Surgeon-performed ultrasonography is increasingly becoming part of the initial evaluation of patients after blunt or penetrating trauma. Currently, most institutions obtain a subxyphoid or subcostal view of the heart and pericardial space, and a three-view ultrasonogram of the abdomen to detect blood in the pericardial sac or in three dependent abdominal areas.', 'A left parastemal standard transverse transthoracic view is described in addition to the aforementioned views. This facilitates the visualization of the pericardial sac when a subxyphoid or subcostal view cannot be obtained because of anatomical reasons (narrow subxyphoid space) or local factors (pain, fractures, subcutaneous emphysema, or chest wall contusion).', 'The transthoracic view can be useful in patients where the subxyphoid view is difficult to obtain through the conventional approach. In most patients an excellent view of the pericardial sac and ventricles can be obtained and, therefore, expedites the diagnosis and treatment of patients with hemopericardium.
Answer: Surgeon-performed ultrasonography has become the diagnostic test of choice for patients suspected of having hemopericardium and cardiac tamponade. Transthoracic ultrasonography is an excellent alternative for those patients where a subxyphoid or subcostal view to visualize the pericardial sac and heart cannot be obtained owing to local or anatomical factors.


Output: Is transthoracic ultrasonography an alternative to subxyphoid ultrasonography for the diagnosis of hemopericardium in penetrating precordial trauma?