Plasma elaidic acid level is associated with periodontal health in American adults: A cross-sectional study.

Background: Whether there is an association between TFAs and periodontitis is unclear. The purpose of this study was to investigate the relationship between moderate/severe periodontitis and plasma level of elaidic acid, a major trans-fatty acid component, in American adults. Methods: The National Health and Nutrition Examination Survey (NHANES) years 2009-2010 were used to screen a total of 1,610 people. The independent variable of interest is plasma elaidic acid level, the dependent variable is periodontitis, and the covariates include socio-demographic variables, lifestyle variables, systemic diseases, etc. The distribution of variables in the covariate differences between the different independent groups according to tertile was investigated using a multiple linear regression model. To examine the association between plasma elaidic acid levels and moderate/severe periodontitis, three models were used. Results: Multiple logistic regression analysis showed a significant association between plasma elaidic acid level and moderate/severe periodontitis after adjustment for potential confounders (OR = 1.021, 95%CI: 1.004-1.039, P = 0.01394). Subjects with the highest tertile of plasma elaidic acid levels were 51.9% more likely to have periodontitis compared with subjects with the lowest tertile of plasma elaidic acid levels (OR = 1.519, 95% CI: 1.136-2.030, P = 0.00477). No possible sources of heterogeneity were identified in the subgroup analyses. Conclusion: Plasma elaidic acid levels are associated with periodontal disease in American adults.

Microdiffraction measurements of natural tooth by high resolution X-ray diffraction equipment / 生物医学工程学杂志

The main mineral component of natural tooth was determined as calcium apatite many years ago; most of them exist in the form of hydroxyapatite with different crystallites. If a tooth decayed, the crystalline of hydroxyapatite would be changed and decomposed. In our experiment, a natural tooth with caries was measured by high resolution XRD equipment: X'pert Pro. Three spots which included normal enamel, normal dentin and caries tissue were analyzed. The results showed that tooth was a kind of biological mixed crystal composed of many crystal phases, the main crystal phase was hydroxyapatite. From normal enamel to normal dentin and to caries tissue, the length of the a-axis of hydroxyapatite crystallite increased, the length of the c-axis of hydroxyapatite crystallite remained unchanged. The crystal sizes were: normal enamel D002 = 27.600 nm; normal dentin D002 = 16.561 nm; caries tissue D002 = 13.163 nm. Crystallinity: normal enamel>normal dentin>caries tissue. According to our experiment, tooth could be conveniently studied by high resolution microdiffracion XRD equipment.

A study of CD44v6 expression in parotid pleomorphic adenomas / 实用口腔医学杂志

To explore the relationship of the expression of CD44v6 with tumor recurrence in parotid pleomorphic adenoma and its clinical significances,SP immunohistochemical staining was employed in the 10 cases of CPA and 10 cases of PA,10 cases of normal parotids.The relationship of the expression of CD44v6 with tumor recurrence in parotid pleomorphic adenoma was studied.The positive rate of expression of CD44v6 in CPA was much lower than that in PA tissues,the positive rate of expression of CD44v6 in CPA and PA was significantly higher than that in normal parotid tissues.The expression of CD44v6 in CPA tissues was lower than that in PA tissues and may be correlated with tumor recurrence.