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.

Ex Input:
Context: Postoperative neurologic deficits after thoracic aortic reconstruction vary widely. Our previous study showed that delayed ischemic preconditioning could prevent spinal cord injury caused by occlusion of the descending thoracic aorta in pigs. We investigated early ischemic preconditioning in the same model.', 'Twenty-eight pigs were divided into 4 groups: group 1 (n = 6) underwent a sham operation, group 2 (n = 6) underwent aortic occlusion for 20 minutes, group 3 (n = 8) underwent aortic occlusion for 35 minutes, and group 4 (n = 8) underwent aortic occlusion for 20 minutes and underwent aortic occlusion 80 minutes later without hypotension for 35 minutes. Aortic occlusion was accomplished by using 2 balloon occlusion catheters placed fluoroscopically at T6 to T8 above the diaphragm and at the aortic bifurcation. Neurologic evaluation was performed by an independent observer according to the Tarlov scale (0-4). The lower thoracic and lumbar spinal cords were harvested at 120 hours and examined histologically with hematoxylin-and-eosin stain. Histologic results (number of neurons and grade of inflammation) were scored (0-4) and were similarly analyzed. Statistical analysis was by means of the Kruskal-Wallis test.', 'Group 4 had a better neurologic outcome at 24, 48, and 120 hours in comparison with group 3 (P <.001). The histologic changes were proportional to the neurologic test scores, with the more severe and extensive gray matter damage in animals of group 3 (number of neurons, P <.001; grade of inflammation, P <.001).
Answer: Early ischemic preconditioning without hypotension protects against spinal cord injury after aortic occlusion, as confirmed by using the Tarlov score and histopathology.

Ex Output:
Does early ischemic preconditioning without hypotension prevent spinal cord injury caused by descending thoracic aortic occlusion?


Ex Input:
Context: Eph receptors, comprising the A- and B-subfamilies, are the largest family of receptor tyrosine kinases in the mammalian genome, and their function is critical for morphogenesis in a variety of contexts. Whereas signaling through B-type Ephs has been demonstrated to play a role in cleft lip and palate (CL/P), the involvement of A-type Ephs has not been examined in this context notwithstanding a recent genome-wide association study that identified the EPHA3 locus as a candidate for non-syndromic CL/P.', 'Here, we present a systematic analysis of the gene expression patterns for the nine EphA receptors at progressive stages of mouse development and find that EphA3, EphA4, and EphA7 exhibit restricted overlapping patterns of expression during palate development. We find that homozygous mutation of EphA3 or compound homozygous mutation of EphA3 and EphA4 in mice does not result in defective midfacial development, supporting the possibility of redundant function with EphA7. We also document previously undescribed expression patterns in other tissues of the craniofacial complex including the lacrimal duct and salivary glands.
Answer: Together, these results are consistent with the hypothesis that mutations in EPHA family genes may cause CL/P and also suggest that functional redundancy between family members may be at play.

Ex Output:
Does embryonic expression of EphA receptor genes in mice support their candidacy for involvement in cleft lip and palate?


Ex Input:
Context: Not all alcoholic patients develop severe liver disease with fibrosis progressing to cirrhosis. It is of practical importance to determine whether some markers can predict progression of liver fibrosis.', 'We used a baboon model that mimics human alcoholic liver disease. Cytokeratin 7 and 19 expression and fat deposition were investigated in serial liver biopsies of 18 animals undergoing prolonged alcohol administration (range 2-17 years) and in four controls. Fibrosis was graded histologically and was also assessed quantitatively by image analysis.', 'Ten animals did not show a progression of liver disease even after 17 years of alcohol administration, but eight animals fed alcohol exhibited a progression of liver disease from no fibrosis or perivenular fibrosis to septal fibrosis or cirrhosis within 7 years. In normal liver, cytokeratin 7 and cytokeratin 19 immunostaining is restricted to bile duct cells. Hepatocellular cytokeratin 7 was observed only in those animals which progressed to more severe stages of fibrosis and it anticipated this progression by 4.2 years on average.
Answer: In alcohol-fed baboons, cytokeratin 7 staining of hepatocytes (but not cytokeratin 19, nor fat deposition) predicts with a high degree of sensitivity and specificity progression to more severe liver disease.

Ex Output:

Does cytokeratin 7 staining of hepatocytes predict progression to more severe fibrosis in alcohol-fed baboons?