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: Elevated levels of B-type natriuretic peptide (BNP) are associated with adverse clinical outcomes in acute coronary syndrome (ACS), but several questions remain outstanding. Firstly, it has not yet been determined whether an additional BNP sample at 7 weeks post ACS would enhance risk prediction. Secondly, we assessed whether the prognostic potential of BNP in ACS could be explained by echocardiographic abnormalities such as left ventricular hypertrophy (LVH).', 'We measured bedside BNP levels in 443 consecutive patients presenting with ACS and at 7 weeks outpatient follow-up. Main outcome measure was either all-cause mortality, readmission with ACS, or congestive heart failure) at 10 months from presentation.', 'Of the 443 patients, 120 patients presented with ST-elevation myocardial infarction (27%). There were 90 cardiovascular (CV) events at 10 months. Adjusting for age, sex, hypertension, diabetes mellitus, smoking status, renal dysfunction, left ventricular ejection fraction, and echocardiographic LVH elevated near patient BNP levels (>80 pg/mL) were still associated with subsequent CV events when measured on admission (adjusted relative risk [RR] 2.63 [95% CI 1.34-5.19)] and also at 7 weeks post ACS (adjusted RR 4.12 [95% CI 1.58-10.72]). Patients with persistent BNP elevation at 7 weeks were also at an increased risk of CV events compared to those with an initial high BNP which then fell (unadjusted RR 4.04 [95% CI 1.24-13.15]).
Answer: In ACS, bedside BNP levels predict CV events at 10 months, independent of many echocardiographic abnormalities including LVH. Furthermore, our study suggests that an additional 7 weeks post ACS BNP enhances risk stratification over and above a one-off high BNP at baseline.
[A]: Does serial bedside B-type natriuretic peptide strongly predict prognosis in acute coronary syndrome independent of echocardiographic abnormalities?


[Q]: Context: Impaired neurodevelopmental outcome represents a major morbidity for survivors of infant heart surgery for congenital heart defects. Previous studies in these neonates have reported preoperative microcephaly, periventricular leukomalacia, and other findings. The hypothesis of this study is that preoperative cerebral blood flow is substantially diminished and might relate to preoperative neurologic conditions.', 'Preoperative brain magnetic resonance imaging was performed. Cerebral blood flow measurements in infants with congenital heart defects were obtained by using a novel noninvasive magnetic resonance imaging technique, pulsed arterial spin-label perfusion magnetic resonance imaging. Cerebral blood flow was measured before the operation under standard ventilation and repeated after increased carbon dioxide.', 'A total of 25 term infants were studied. The average age at the time of the operation was 4.4 +/- 4.6 days. Congenital heart defects varied widely. Microcephaly occurred in 24% (6/25). Baseline cerebral blood flow was 19.7 +/- 9.2 mL . 100 g -1 . min -1 (8.0-42.2 mL . 100 g -1 . min -1 ). Five patients had cerebral blood flow measurements of less than 10 mL . 100 g -1 . min -1 . Mean hypercarbic cerebral blood flow increased to 40.1 +/- 20.3 mL . 100 g -1 . min -1 (11.4-94.0 mL . 100 g -1 . min -1 , P < .001). Pairwise analyses found that low hemoglobin levels were associated with higher baseline cerebral blood flow values ( P = .04). Periventricular leukomalacia occurred in 28% (7/25) and was associated with decreased baseline cerebral blood flow values ( P = .05) and a smaller change in cerebral blood flow with hypercarbia ( P = .003).
Answer: Structural brain abnormalities are common in these neonates before surgical intervention. Preoperative cerebral blood flow for this cohort was low and drastically reduced in some patients. Low cerebral blood flow values were associated with periventricular leukomalacia. Carbon dioxide reactivity was preserved but might be compromised by some aspects of the cardiac anatomy. The full spectrum of cerebral blood flow measurements with this technique in congenital heart defects and their long-term significance require continued investigation.
[A]: Is preoperative cerebral blood flow diminished in neonates with severe congenital heart defects?


[Q]: Context: Ingested proteins are known to stimulate a rise in insulin and glucagon concentrations. In our effort to explain this effect, we have begun to measure the effect of individual amino acids.', 'The objectives were to determine the effect of lysine ingestion on insulin and glucagon concentrations and whether the effect is moderated by glucose ingestion.', 'Thirteen healthy subjects were studied on 4 occasions. Water, 25 g glucose, 1 mmol lysine/kg lean body mass, or lysine plus glucose was given on separate occasions at 0800 after a 12-h fast. Serum lysine, glucose, insulin, and glucagon were measured during a 2.5-h period. The amount of lysine provided was equivalent to that present in a 672-g (24-oz) steak.', 'Lysine ingestion resulted in an approximately 3-fold increase in lysine concentration and in a small decrease in glucose concentration. When lysine was ingested with glucose, the 2.5-h glucose area response decreased by 44% (P < 0.02). Lysine alone increased the insulin area response modestly; the insulin increase when lysine was ingested with glucose was similar to that when only glucose was ingested. Lysine stimulated an increase in glucagon (P < 0.02), whereas glucose decreased glucagon.
Answer: Lysine ingestion results in a small decrease in serum glucose and an increase in glucagon and insulin concentrations. Lysine ingested with glucose dramatically attenuated the glucose-stimulated glucose response, but there was no change in insulin response. Whether similar effects will be observed with more physiologic doses of lysine remains to be determined.
[A]:
Does lysine ingestion markedly attenuate the glucose response to ingested glucose without a change in insulin response?