instruction:
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.
question:
Context: Oxidative stress has been considered to play a primary role in the pathogenesis of stress-induced gastric damage. The aim of this study was to investigate the effects of melatonin, ascorbic acid and -carotene on stress-induced gastric mucosal damage.', 'Fifty-six male Wistar albino rats were divided into control, stress, stress + standard diet, stress + saline, stress + melatonin, stress + ascorbic acid and stress + -carotene groups. The rats from stress groups were exposed to starvation, immobilization and cold by immobilizing for 8 h at +4C following 72-hour food restriction. Following stress application, melatonin, ascorbic acid and -carotene were administered for 7 days. Specimens of gastric tissue were prepared for microscopic and biochemical examinations.', 'Mean histopathological damage scores and mean tissue malondialdehyde levels were significantly decreased but mean tissue glutathione levels and glutathione peroxidase and superoxide dismutase activities were increased in treatment groups vs. stress groups in general. Mean histopathological damage scores of the stress + Mel group was lower than those of stress + D, stress + S, stress + -car (p < 0.05) and stress + Asc groups (p < 0.005). Additionally, mean tissue catalase activity of the stress + Mel group was higher than that of stress + S (p < 0.005), stress + D (p < 0.05) and stress + -car groups (p < 0.05).
Answer: Melatonin is more effective than ascorbic acid and -carotene in improvement of gastric damage induced by intensive stress. We suggest that as well as the direct antioxidant and free radical scavenging potency of melatonin, its indirect effect via the brain-gut axis might account for its greater beneficial action against stress-induced gastric damage.
answer:
Is melatonin more effective than ascorbic acid and -carotene in improvement of gastric mucosal damage induced by intensive stress?

question:
Context: Objective analysis of surgical skill is necessary. A novel method of assessment using simple error analysis in synthetic models is examined for construct validity.', 'Two examination protocols were devised using synthetic models. These contained either a purpose made error or were representative of good surgical practice. Protocol one contained models of skin closure and minor operations. Protocol two in addition more complex procedures. Face validity was established by the approval of senior surgeons. Junior surgeons were recruited to undertake the assessment. A p value of less than 0.05 was deemed to be significant.', 'Eighty-nine surgeons were recruited. Both protocol one and two were able to discriminate between groups at statistically significant levels.
Answer: Construct validity has been established by showing that error analysis is able to distinguish surgeons with varying levels of experience.
answer:
Is the surgical error examination a novel method for objective technical knowledge assessment?

question:
Context: To determine whether treatment with corticosteroids decreases the incidence of postextubation airway obstruction in an adult intensive care unit.', 'Clinical experiment.', 'Adult medical and surgical intensive care unit of a teaching hospital.', 'One hundred twenty-eight patients who were intubated for >24 hrs with a cuff leak volume <24% of tidal volume and met weaning criteria.', ': Patients were randomized into a placebo group (control, n = 43) receiving four injections of normal saline every 6 hrs, a 4INJ group (n = 42) receiving four injections of methylprednisolone sodium succinate, or a 1INJ group (n = 42) receiving one injection of the corticosteroid followed by three injections of normal saline. Cuff volume was assessed 1 hr after each injection, and extubation was performed 1 hr after the last injection. Postextubation stridor was confirmed by examination using bronchoscopy or laryngoscopy.', 'The incidences of postextubation stridor were lower both in the 1INJ and the 4INJ groups than in the control group (11.6% and 7.1% vs. 30.2%, both p < .05), whereas there was no difference between the two treated groups (p = .46). The cuff leak volume increased after the second and fourth injection in the 4INJ group and after a second injection in the 1INJ group compared with the control group (both p < .05).
Answer: A reduced cuff leak volume is a reliable indicator to identify patients at high risk to develop stridor. Treatment with a single or multiple injections of methylprednisolone can effectively reduce the occurrence of postextubation stridor.
answer:
Does intravenous injection of methylprednisolone reduce the incidence of postextubation stridor in intensive care unit patients?