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.
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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: The aim of this study was to evaluate how closely analysis of bone quality performed using the bone mineral density (BMD) values obtained by quantitative computerized tomography (QCT) reflected the histologic bone density.', "Eighteen patients requiring implant therapy underwent CT scanning. Their data were processed using Image Master software, and the BMD was calculated by measuring the Hounsfield units and relating those values to a phantom (Calibration Phantom, Quantitative Technologies). Each patient wore a radiographic-surgical template in which titanium cylinders were placed as a drilling guide for preparation of the implant site. The mouth regions where the titanium guides were placed (on the CT images and in the patient's mouth) corresponded to the implant sites where the BMD was measured and where tissue specimens for histomorphometric analysis retrieved. Forty specimens measuring 6 mm in length and 2 mm in diameter were obtained. Histomorphometric analysis was performed by digitizing the images, which were subsequently analyzed using the image analysis software IAS 2000. The bone volume (BV) was calculated as a percentage by dividing the area occupied by the mineralized bone over the entire microscopic field.", 'The results of the statistical analysis showed a Pearson correlation coefficient of 0.691 between the BV and BMD values, with a P value < 0.01, which was considered significant.
Answer: The results of this study support the use of QCT to assess the bone quality before implant placement to improve the planning of implant treatment.

Answer: Are bone mineral density and bone histomorphometry statistically related?

Question: Context: Coagulation abnormalities which occur as a consequence of endothelial changes are recognized as diagnostic criteria for sepsis, but significance of these changes in the outcome prognosis and prediction of the course of sepsis is still not accurately defined.', '60 patients who fulfilled the criteria for diagnosis of sepsis were included in our study. Patients were categorized in two groups according to sepsis severity and organ failure and MODS development was assessed in the first 48 h from ICU admission. Prothrombin time (PT), activated partial thromboplastin time (aPTT) and endothelial cell specific molecule-1(endocan) levels, as well as procalcitonin (PCT) and C-reactive protein (CRP) were determined within the first 24h of the onset of the disease. Predictive APACHE II (Acute Physiology and Chronic Health Evaluation II) and SOFA (Sequential Organ Failure Assessment) scores were calculated on the day of ICU admission. Data were used to determine an association between day 1 biomarker levels, organ dysfunction score values and the development of organ failure, multiple organ dysfunction syndrome (MODS), and mortality during 28 days. These connections were determined by plotting of receiver operating characteristic (ROC) curves. Differences between groups were assessed by Mann-Whitney U test. Categorical variables were compared using chi-square test.', 'Concentration of endocan was significantly higher in the group of patients with sepsis induced organ failure, MODS development and in the group of non- survivors in contrast to group with less severe form of the disease, without multiorgan failure, and in contrast to group of survivors (p<0.05). Values of areas under the ROC curves showed that endocan levels had good discriminative power for more severe course of sepsis, MODS development and possible discriminative power for mortality prediction (AUC: 0.81, 0.67, 0.71 retrospectively), better than PCT for fatality (AUC:053) and better than APACHE II (AUC:0.55) and SOFA (AUC: 0.57) scores for organ failure.
Answer: Results of our study show that endocan can be used as strong and significant predictor of sepsis severity and outcome, perhaps even better than SOFA and APACHE II scores.

Answer:
Is endocan useful biomarker of survival and severity in sepsis?