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: Increasing evidence points to the inflammatory character of atherosclerosis and several parameters of inflammation have been proposed as cerebrovascular risk markers. The objective of the research was to examine the connection of serum inflammatory parameters and ultrasound (US) characteristics of the structure and size of carotid plaque. We assumed that the number of leukocytes (Le) was an indicator of carotid plaque instability and an increased risk of stroke.', 'Serum inflammatory parameters: erythrocyte sedimentation rate in the first (ESR I) and second hour (ESR II), the number of Le, high sensitivity C-reactive protein (hsCRP) and fibrinogen were measured by standard methods. All the subjects (n = 75) were divided into 3 groups (symptomatic, asymptomatic and control). US evaluation of extracranial carotid arteries was performed in a duplex system. Plaques were classified into categories according to stenosis percentage ( 50%, < 50%) and pursuant to echomorphological characteristics (Gray-Weale classification). In the subjects with stroke an ischemic lesion was confirmed by computed tomography.', 'The average values of biochemical parameters in the symptomatic group were: ESR I 29.57 29.87 cm, ESR II 51.60 36.87 cm, the number of Le 10.10 3.20 x 10 U/L, hsCRP 8.15 5.50 mg/L and fibrinogen 4.03 0.70 g/L. The average values of all testing biochemical parameters in symptomatic patients were significantly higher than in the asymptomatic ones and the control group: for ESR I (p < 0.05) and ESR II (p < 0.05); for the number of Le (p < 0.001); for hsCRP (p < 0.001) and fibrinogen (p < 0.001). Category I of echomorphological characteristics in the symptomatic group was present in 66.7% of the cases and it was significantly higher than in the asymptomatic (40.0%; p < 0.05) and the control group (20.0%; p < 0.01). Univariate logistic regression analysis confirmed that all testing biochemical parameters are indicators of stroke risk. Multivariate logistic regression analysis confirmed a statistically significant correlation of the number of Le and stroke risk, while the increase in the value by a unit of measurement was associated with the growth of risk by 3.22 times (from 1.67 to 6.22).
Answer: The number of Le is associated with the phenomenon of carotid plaque instability and may be a useful additional marker of increased risk for developing acute cerebral infarction.

Ex Output:
Does leucocyte count indicate carotid plaque instability in stroke patients?

Ex Input:
Context: The perinucleolar compartment (PNC) is a subnuclear structure localized at the nucleolar periphery. Previous studies using breast cancer as a model system demonstrated that PNC prevalence (the percentage of cells with 1 or more PNC) increased with disease progression and was associated with poor patient outcomes.', 'To evaluate the validity of developing PNC prevalence as a novel pancancer prognostic marker, the authors investigated whether PNC prevalence was correlated with malignancy in a spectrum of tissue types and evaluated its selective association with malignancy under various experimental conditions.', 'PNC prevalence was low in primary and immortalized cells and in cell lines derived from hematologic malignancies, but it was heterogeneous in cell lines derived from solid tumors, including those of epithelial and nonepithelial origins. Studies using human myometrial tissue and thyroid cancer cell lines with various levels of malignancy demonstrated a correlation between high PNC prevalence and malignant potential. Furthermore, PNC prevalence corresponded directly to metastatic capacities in a series of well characterized cell lines of the same origin that were selected for various levels of metastatic capacity in a mouse model. Conversely, PNC prevalence was reduced experimentally by over expressing an antimetastatic protein in breast cancer cells. However, PNC prevalence was not associated with traits that were shared by both cancer and normal cells, including proliferation, glycolysis, and differentiation.
Answer: Together, these observations helped to verify that PNC prevalence selectively represents malignancy in a broad spectrum of solid tissue tumors, demonstrating its potential to be developed as a pancancer prognostic marker of malignancy.

Ex Output:
Is perinucleolar compartment prevalence a phenotypic pancancer marker of malignancy?