OBJECTIVE:To explore the association between the mitochondrial DNA(mtDNA)3537A/G,5351A/G variant and type 2diabetes mellitus(T2DM)in northem Chinese population.METHODS:The subjects including 614 patients with T2DM in Dalian City,61 of them were collected from family survey,497 of them were collected from Department of Endocrine,Dalian Municipal Central Hospital,and the remained 56 were selected from diverging T2DM patients in Dalian City.Additional 344 cases with normal carbohydrate toierance were served as controls.The mtDNA 3537A/G.5351A/G variants in 614 patients with T2DM and 334 healthy control subjects were examined.By sequencing the mtDNA in 24 cases and 26 controls,2 candidate SNPs in mtDNA were determined,and then genotyping was carried out by using PCR restriction fragment length polymorphism(PCR-RFLP)analysis.RESULTS:The frequency of mtDNA A3537G and A5351G mutation was 2.0%and 2.6% in T2DM patients,respectively,which was 2.1%and 4.2% in the control group.No significant difference had been observed between case and control(P＞0.05).After stratifying by body mass index and blood pressure,we found that the frequency of A5351 G in obesity patients with T2DM was 1.61%,and in obesity control was 15.38%,which had significant difference(P_(Fisher)=0.02,OR=2.76),however,A3537G stili showed no significant difference in all groups(P＞0.05).CONCLUSION:5351A/G in mtDNA ND2 gene may be a variance associated with T2DM in northem Chinese.

Objective: To investigate the distribution of fimA and kgp genotypes as well as the common genotype combination of Porphyromonas gingivalis (Pg) in infected root canals of primary apical periodontitis for virulent isolates screening in future. Methods: Thirty-four samples harboring Pg were selected from infected root canals of primary apical periodontitis from patients of the Department of Endodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine from June 2013 to September 2015. FimA type-specific primers were used to amplify the samples, revealing the distribution of various fimA genotypes. The genotypes of kgp were obtained by using Mse Ⅰ restriction endonuclease. The prevalence of each genotype and common genotype combinations were then calculated. Pearson's chi-squared test was performed to analyze the correlation between genotype combinations and clinical symptoms and major signs of apical periodontitis. In addition, the bioflim architectures between Pg isolates with different fimA and kgp genotype combinations were observed compared using confocal laser scanning microscope. Results: Among the 34 Pg-positive samples, fimA Ⅱ was the most prevalent genotype [47% (16/34)] followed by fimA Ⅰ [26% (9/34)], while fimA Ⅴ was detected in only one sample. The prevalence of kgp Ⅰ [56% (19/34)] was slightly higher than that of kgp Ⅱ [44% (15/34)]. Both fimA Ⅱ+kgp Ⅰ and fimAⅡ+kgp Ⅱ were the most prevalent genotype combinations [24% (8/34) each]. No significant correlation was found between specific genotype combination and such major clinical manifestations as gingival swelling and sinus tract of dental origin (P>0.05). Three Pg isolates with different genotype combinations were acquired. Isolate A (fimAⅠ+kgpⅠ) formed densest biofilm, while the biofilm of isolate C (fimAⅤ+kgp Ⅰ) was much looser. The biofilm feature of isolate B (fimAⅢ+kgp Ⅱ) fell in between A and C. Conclusions Pg with fimA Ⅱ was most frequently detected in infected root canals of primary apical periodontitis. The prevalence of Pg with kgp Ⅰ was slightly higher than that with kgp Ⅱ, and fimAⅡ+kgp Ⅰ as well as fimA Ⅱ+kgp Ⅱ were the commonest genotype combinations. According to the comparison of Pg biofilms formed by clinical isolates, it might be possible that different genotype combinations may lead to distinct biofilm architectures.