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.

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

Context: There is an increasing knowledge that the severity of perennial allergic rhinitis is associated with nasal carriage of Staphylococcus aureus (S. aureus). The aim of this study was to evaluate the rate of bacterial colonization with S. aureus in the nose of subjects with and without chronic rhinosinusitis (CRS) and to correlate these findings with the severity of symptoms and the extent of the disease.', 'Open, prospective controlled trial.', "190 subjects with CRS and 42 subjects with septal deviation without sinusitis (control subjects) were included in this study. Swabs were taken endoscopically from the middle meatus and bacteria were cultured and identified. Airway symptoms were assessed by subjects in standardized questionnaires and frequencies of respiratory tract infections were noted. The rhinosinusitis extent was graded by CT scan assessment. Analysis of variance, chi-square test, and Pearson's correlation test were applied for statistical analyses.", 'The S. aureus carriage rate was 25.5% in CRS and 31.4% in control subjects. Further facultative pathogens were cultured in 20.6% of subjects with CRS and in 8.5% of controls. 73.8% of S. aureus were ampicillin-resistant, multiresistant strains were cultured in 5.8%. Most airway symptoms and the frequencies of respiratory tract infections were significantly higher in the CRS group compared with control subjects. In post hoc comparison between the subgroups with and without S. aureus colonization, no significant differences were found between the extent of rhinosinusitis and the severity of airway symptoms.
Answer: Facultative pathogens were detected in more than 40% of CRS patients without acute respiratory tract infections. In contrast to the findings in atopic dermatitis and perennial allergic rhinitis, the colonization rate with S. aureus is not increased and S. aureus carriage is not a risk factor for the severity or the extent of rhinosinusitis.
Is nasal colonization with Staphylococcus aureus associated with the severity of symptoms or the extent of the disease in chronic rhinosinusitis?

Context: It has been reported that beta-blockers (BB) reduce cardiovascular events in patients with atherosclerotic disease. However, little is known about the efficacy of these drugs in patients with critical limb ischemia (CLI). We investigated whether beta-blocker therapy affects the clinical outcomes of CLI patients.', 'Between March 2004 and December 2011, 1,873 consecutive CLI patients who received endovascular therapy (EVT) (394 BB-treated patients and 1,479 non-BB-treated patients) for de novo infrainguinal lesions were identified retrospectively. A propensity score analysis was used for risk adjustment in a multivariable analysis and one-to-one matching (BB: 305, non-BB 305). The primary endpoint was amputation-free survival (AFS), and the secondary endpoints were overall survival and the rates of limb salvage and freedom from major adverse limb events (MALE; including repeat reintervention, surgical conversion and major amputation). The mean follow-up period was 22 ± 15 months.', 'In the propensity score-matched pair analysis, there were no significant differences in AFS between the patients treated with and without beta-blockers (58.8% vs. 58.5% at three years, log-rank p = 0.76). There were also no significant differences in the limb salvage rate (88.3% vs. 88.8 at three years, log-rank P = 0.41), overall survival (63.0% vs. 62.4% at three years, log-rank P = 0.70) and freedom from MALE (43.6% vs. 44.9% at three years, log-rank P = 0.58) between the patients treated with and without beta-blockers.
Answer: The present results suggest that beta-blocker therapy does not worsen the clinical outcomes after EVT in CLI patients.

Does beta-blocker Treatment Worsen Critical Limb Ischemia in Patients Receiving Endovascular Therapy?