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.
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Question: Context: To assess the role of whole-body computed tomography (CT) for determining morphological suitability before multiorgan retrieval (MOR) in brain dead patients.', 'Fifty-one clinically brain dead patients (21 women, 30 men; mean age 61 year±15) were included in this prospective, single center study. All patients had CT angiography of the brain and whole-body CT examination. CT images were evaluated for the presence of morphological abnormalities of lungs, liver and other abdominal organs and presence of vascular anatomical variants. The results of CT examinations were compared to intraoperative findings observed during organ harvesting and/or the results of histopathological analysis of biopsy specimens. The impact of whole-body CT examination on the harvesting process was evaluated.', 'Ninety-five percent of vascular anatomical variants that were found intraoperatively were depicted on CT. CT density measurements predicted surgical finding of steatosis in 80% of patients. Whole-body CT changed the MOR strategy in 21/51 patients (41%) including 3 MOR cancellations and 8 grafts refusals, whereas organ harvesting was continued in 10 patients after histopathological analysis was performed.
Answer: Selection of potential graft donors using whole-body CT is reliable and improves graft selection during MOR.

Answer: Is simultaneous CT angiography and whole-body CT an effective imaging approach before multiorgan retrieval?


Question: Context: Gastric lipase is an important enzyme for dietary triglyceride digestion in normal subjects. Its regulation is unknown, as is the relation between the quantity and activity of the enzyme.', 'In a dose-response study we investigated the effect of low doses of pentagastrin (less than 1000 ng/kg/h) on the output of gastric lipase measured by a kinetic assay and an enzyme-linked immunosorbent assay (ELISA).', 'In five healthy volunteers stepwise intravenous pentagastrin infusions of 0, 50, 100, 500, and 1000 ng/kg/h resulted in a stepwise increase in the lipase output, as measured with ELISA. However, the lipolytic activity, measured with a kinetic assay, decreased as the pH of the gastric contents decreased.
Answer: We conclude that secretion of the gastric lipase is stimulated by pentagastrin, but the simultaneous secretion of acid counteracts the lipolytic activity of the enzyme when food is not present.

Answer: Do low doses of pentagastrin stimulate gastric lipase secretion in man?


Question: Context: Thromboxane has been shown to contribute to coronary constriction in conduit coronary arteries during platelet aggregation at the site of a critical stenosis. Previous studies from our laboratory suggest that following a critical coronary stenosis, persistent vasomotor tone occurs. We tested the hypothesis that thromboxane is responsible for that increased tone.', 'To test this hypothesis, 14 mongrel dogs of either sex were anesthetized and subjected to a critical coronary stenosis where distal coronary perfusion pressure was reduced to 36 +/- 2 mm Hg. During the coronary stenosis, SQ 29,548 (thromboxane/endoperoxide receptor antagonist) was administered intravenously (0.2 mg/kg and 2.0 mg/kg). Coronary microvascular responses were observed by directly visualizing the epicardial microcirculation. Diameters were measured using intravital microscopy coupled to stroboscopic epi-illumination and jet ventilation to compensate for cardiac and respiratory-induced motion.', 'Coronary microvessels were divided into small (< 150 microns) and large (> 150 microns) arterioles. During SQ 29,548 administration, small coronary arterioles demonstrated no additional dilation during a critical coronary stenosis. In contrast, coronary microvessels > 150 microns demonstrated a dose-dependent vasodilation to SQ 29,548 (0.2 mg/kg: 6 +/- 2%; 2.0 mg/kg: 11 +/- 4%; P < 0.05 vs. no change). A time control study in six additional animals demonstrated no significant microvascular diameter changes following a critical stenosis over the time course of SQ 29,548 administration.
Answer: Endoperoxides contribute to poststenotic microvascular vasoconstriction in vessels 150-300 microns.

Answer:
Does thromboxane contribute to submaximal coronary dilation during myocardial ischemia?