Given a passage, 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.

[Q]: Vitamin D is associated with a number of inflammatory diseases and plays a significant role in regulating bone metabolism. Serum calcifediol was demonstrated to be potentially associated with periodontal disease. The purpose of this study was to evaluate whether an association exists between plasma calcifediol concentrations and aggressive periodontitis (AgP) and whether plasma levels of bone-related biomarkers (osteocalcin, alkaline phosphatase, calcium, and phosphorus) regulated by vitamin D are related to AgP.', 'Sixty-six patients with generalized AgP, 52 patients with chronic periodontitis, and 60 healthy controls were included in this study. Periodontal examination consisted of probing depth, attachment loss, and bleeding index measurements. Hematic calcifediol and bone-related biomarker levels were detected using radioimmunity assay kits or a biochemical analyzer.', 'Plasma calcifediol levels in patients with AgP were higher than those of healthy controls (29.28 versus 21.60 nmol/l; P <0.05) and were statistically significantly correlated with bleeding index (r = 0.321; P <0.05). Plasma osteocalcin concentrations in patients with AgP were higher than those of healthy controls (0.90 versus 0.70 ng/ml; P <0.05). Serum inorganic phosphorus values of both periodontitis groups were lower than those of healthy controls (1.06 +/- 0.18 mmol/l and 1.10 +/- 0.15 mmol/l versus 1.26 +/- 0.17 mmol/l; P <0.05).
[A]: Is elevated plasma calcifediol associated with aggressive periodontitis?

[Q]: The modification of the Model for End-Stage Liver Disease (MELD) scoring system (Refit MELD) and the modification of MELD-Na (Refit MELDNa), which optimized the MELD coefficients, were published in 2011. We aimed to validate the superiority of the Refit MELDNa over the Refit MELD for the prediction of 3-month mortality in Korean patients with cirrhosis and ascites.', 'We reviewed the medical records of patients admitted with hepatic cirrhosis and ascites to the Konkuk University Hospital between January 2006 and December 2011. The Refit MELD and Refit MELDNa were compared using the predictive value of the 3-month mortality, as assessed by the Child-Pugh score.', 'In total, 530 patients were enrolled, 87 of whom died within 3 months. Alcohol was the most common etiology of their cirrhosis (n=271, 51.1%), and the most common cause of death was variceal bleeding (n=20, 23%). The areas under the receiver operating curve (AUROCs) for the Child-Pugh, Refit MELD, and Refit MELDNa scores were 0.754, 0.791, and 0.764 respectively; the corresponding values when the analysis was performed only in patients with persistent ascites (n=115) were 0.725, 0.804, and 0.796, respectively. The significant difference found among the Child-Pugh, Refit MELD, and Refit MELDNa scores was between the Child-Pugh score and Refit MELD in patients with persistent ascites (P=0.039).
[A]: Is the Refit model for end-stage liver disease-Na a better predictor of mortality than the Refit model for end-stage liver disease in patients with cirrhosis and ascites?

[Q]: There have been investigations on the chemopreventive effect of nonsteroidal anti-inflammatory drugs (NSAIDs) in gastric cancer and also on the association between cyclo-oxygenase 2 expression and the clinicopathological features of gastric cancer. However, it is not yet clear whether the cardioprotective properties of low-dose aspirin could affect the biological behavior of gastric cancer. This study was aimed at investigating the association between the use of low-dose aspirin and clinicopathological features of gastric cancer in human.', 'A case-control study was performed retrospectively by comparing the clinicopathological parameters between two groups of gastric cancers, 47 (30.5%) low-dose aspirin users and 107 (69.5%) non-aspirin users who were diagnosed and underwent operation for gastric cancers.', 'The gastric cancers of aspirin user group showed favorable clinicopathological features, such as earlier tumor stage (overall stage, T and N stage: p < 0.001, <0.001, and 0.002, respectively), smaller size (p = 0.03), and intestinal type rather than diffuse type (p = 0.004). But these differences were significant only in non-cardiac cancer while cardiac cancer patients showed no significant association with low-dose aspirin usage (overall stage, T stage, N stage, tumor size, and histological type: p <0.001, <0.001, 0.003, 0.035, and 0.004, respectively, by Cochran-Mantel-Haenszel statistics).
[A]:
Does low-dose aspirin affect the clinicopathological features of gastric cancer?