IL6 −174 Genotype Associated with Aggregatibacter actinomycetemcomitans in Indians

Oral Diseases (2011) 17 , 232–237 Aim: Genetic factors have recently been associated with presence of Aggregatibacter actinomycetemcomitans subgingivally in populations living in industrialized countries. The aim of this study was to analyse associations between Interleukin‐6 (IL6) single nucleotide polymorphisms and presence and levels of A. actinomycetemcomitans and other subgingival microbes in a rural Indian population. Subjects and Methods: A total of 251 individuals from a rural village in India with a periodontal phenotype ranging from healthy to severe periodontitis were included. Checkerboard DNA‐DNA analysis was performed to detect 40 periodontal taxa in subgingival plaque samples. Genomic DNA was extracted to genotype five polymorphisms in the IL6 promoter region. Results: The IL6 ?174 GG genotype was associated with high (above median) counts of A. actinomycetemcomitans (both in all subjects and in periodontally healthy only) and with presence and counts of Capnocytophaga sputigena. Differences in detection of several other bacteria were noted between periodontitis and healthy subjects. Conclusions: These findings support the influence of genetic factors on the subgingival microbiota.     

Solution of Ni−Cr alloy oxides in an alkali alumino-silicate glass

During fusion of porcelain onto metal substrates, oxides on the alloy are dissolved by the glassy phase of the porcelain. The extent of solution needed for development of a bond has been discussed in theory, but measurements of oxide thickness and solubility have proven difficult to obtain. In this study, the interfacial compositions of Ni−Cr alloy/glass couples were determined using Auger analysis. The samples consisted of buttons of glass fused to 5 proprietary Ni−Cr alloys. After dissolution of the alloy by a 10% Br-methanol solution, the glass was analyzed. The diffusion profiles of elements in the oxide indicated incomplete dissolution of the oxide by the glass. High amounts of silicon were also found at the alloy/oxide interface.     

Inhibition of Candida albicans by the peroxidase/SCN−/H2O2 system

Effects of the salivary peroxidase (SPO) system on the growth, glucose uptake and metabolic activities of oral bacteria are well documented but the effects on oral fungi are virtually unknown. Therefore, the viability of Candida albicans (ATCC 28366) exposed to the peroxidase/SCN^?/H₂O₂: system was studied in sterilized saliva, in phosphate-buffered saline (PBS) and in potassium chloride. The growth of C. albicans in glucose-supplemented saliva was faster at pH 5.5 than at pH 7. The addition of the complete SPO (or lactoperoxidase) system to either sterilized saliva, KC1 (50 μM) or PBS at pH 5.5 inhibited dose-dependently the viability of C. albicans in KC1, but no inhibition was found in PBS or saliva. Maximal inhibition was achieved in 2 h and with > 320 μM of peroxidase-generated HOSCN/OSCN^?. However, physiological salivary concentrations of phosphate (> 1.0 μM) and PBS blocked the antifungal effect of HOSCN/OSCN^?. The relative proportions of SCN^? and H₂O₂: were critical to the antifungal effects. With 0.2 mM KSCN, a complete loss of viability was achieved, though the HOSCN/OSCN^? concentrations did not exceed 100 μM. It is concluded that C. albicans is sensitive to HOSCN/OSCN^? but salivary concentrations of phosphate block the antifungal effect of the peroxidase systems.     

Association Between Interleukin‐4 Gene −590 C/T, −33 C/T,and 70‐Base‐Pair Polymorphisms and Periodontitis Susceptibility: A Meta‐Analysis

Background: Several studies have investigated the association between interleukin (IL)‐4 gene ?590 C/T, ?33 C/T, or 70–base pair (70‐bp) polymorphisms and periodontitis susceptibility but with conflicting results. Hence, a meta‐analysis was conducted to explore whether these polymorphisms are associated with periodontitis susceptibility. Methods: A comprehensive literature search was conducted of PubMed, Embase, Scopus, ScienceDirect, and Web of Science up to April 5, 2014. After the eligible studies were identified, data were extracted and quality‐assessed before performing the meta‐analysis. Results: The meta‐analysis included 23 eligible case‐control studies from 11 articles involving 12 studies of the ?590 C/T polymorphism (1,220 cases and 2,039 controls), five of the ?33 C/T polymorphism (715 cases and 967 controls), and four of the 70‐bp polymorphism (426 cases and 506 controls). The meta‐analysis showed that none of these IL‐4 gene polymorphisms were significantly associated with periodontitis susceptibility in all study participants. However, subgroup analysis showed that the IL‐4 ?590 T allele (odds ratio [OR] = 1.2, 95% confidence interval [CI] = 1.02 to 1.42, P = 0.03) and TT genotype (OR = 1.68, 95% CI = 1.05 to 2.67, P = 0.03) were associated with periodontitis in whites. Conclusions: Based on current evidence, the IL‐4 ?33 C/T and 70‐bp polymorphisms were not associated with an increased risk of periodontitis. However, the IL‐4 ?590 T allele and TT genotype were associated with increased risk of periodontitis in whites.     

O19 H2S inhibits O2− scavenger and causes oxidative damage in vivo

Objective Volatile sulphur compounds (VSCs), namely hydrogen sulfide and methyl mercaptan have been demonstrated to initiate or progress periodontal disease by increasing the permeability of sulcal epithelium and the degradation of extracellular matrices. Superoxide dismutase (SOD) is one of the most important antioxidative enzymes in intracellular protection against superoxide free radicals which may cause cancer or aging process. The objectives of this study were to demonstrate that hydrogen sulfide, a major contributor to oral malodor, inhibits SOD activity, and to determine if VSCs cause oxidative damage. Methods Cu,Zn‐ and Mn‐SOD, and human gingival fibroblast (HGF) SOD activities were examined with the determination of the inhibitory activity of the production of 2‐(4‐Iodophenyl)‐3‐(4‐nitrophenyl)‐5‐(2,4‐disulfophenyl)‐2H‐tetrazolium formazan. Western blot analysis was employed to determine the effect of hydrogen sulfide on SOD molecules. Oxidative damage was determined with comet, caspase III and other assays. Results and discussion The activity of Cu,Zn‐SOD (0.01 U ml^?1) was found to decrease by 83% when exposed to 52 ng/10 ml of hydrogen sulfide for 60 min (P < 0.0001 by ANOVA and P < 0.001 by Tukey's multiple comparison test) and that of HGF‐SOD decreased by 46% (P < 0.0001 by ANOVA and P < 0.001 by Tukey's multiple comparison test). The inhibition of SOD by H₂S was both time‐ and concentration‐dependent. Following exposure to VSC, SOD activity resumed after incubation in air. The results suggested that the inhibition might be reversible. VSC might cleave the disulfide bonds and might produce monomeric SOD resulting in reversible inhibition. However, Western blot analysis has not demonstrated monomeric SOD. Comet assay and other examination demonstrated that VSC caused oxidative damage and apoptosis. Conclusion SOD is the body's major defence against oxidative damage. Cu,Zn‐ and Mn‐SOD, and human gingival fibroblast (HGF) SOD activities were strongly inhibited by hydrogen sulfide. The inhibition of SOD resulted in oxidative damage and apoptosis.     

Investigation of matrix metalloproteinase‐1 −1607 1G/2G polymorphism in a Turkish population with periodontitis

Aim: Matrix metalloproteinase‐1 (MMP‐1) is a proteolytic enzyme that degrades extracellular matrix and plays a fundamental role during destruction of periodontal tissues. The aim of this study was to examine the association between MMP‐1 ?1607 1G/2G polymorphism and chronic periodontitis susceptibility in a Turkish population. Material and Methods: A total of 180 subjects were enrolled in this study. All the subjects received a periodontal examination including full‐mouth clinical attachment loss measurements, probing depths, plaque index scores, gingival index scores and radiographic bone loss ratios. Three groups formed according to periodontal conditions were healthy, moderate periodontitis and severe periodontitis groups. MMP‐1 ?1607 1G/2G gene promoter polymorphism was genotyped using a polymerase chain reaction‐restriction fragment length polymorphism method. Results: Analysis of the polymorphism showed no differences in distribution of the MMP‐1 ?1607 1G/2G polymorphism among healthy, moderate periodontitis and severe periodontitis groups (p>0.05). When the groups were further stratified by smoking status, we found no significant differences in genotype distributions, allele frequencies and carriage rates among any groups either (p>0.05). Conclusions: On the basis of the results, no significant association is found for the MMP‐1 ?1607 1G/2G polymorphism with susceptibility to periodontitis. Moreover, smoking status did not seem to affect this result.     

Aloin Inhibits Interleukin (IL)‐1β−Stimulated IL‐8 Production in KB Cells

Background: Interleukin (IL)‐1β, which is elevated in oral diseases including gingivitis, stimulates epithelial cells to produce IL‐8 and perpetuate inflammatory responses. This study investigates stimulatory effects of salivary IL‐1β in IL‐8 production and determines if aloin inhibits IL‐1β?stimulated IL‐8 production in epithelial cells. Methods: Saliva was collected from volunteers to determine IL‐1β and IL‐8 levels. Samples from volunteers were divided into two groups: those with low and those with high IL‐1β levels. KB cells were stimulated with IL‐1β or saliva with or without IL‐1 receptor agonist or specific mitogen‐activated protein kinase (MAPK) inhibitors. IL‐8 production was measured by enzyme‐linked immunosorbent assay (ELISA). MAPK protein expression involved in IL‐1β?induced IL‐8 secretion was detected by Western blot. KB cells were pretreated with aloin, and its effect on IL‐1β?induced IL‐8 production was examined by ELISA and Western blot analysis. Results: Saliva with high IL‐1β strongly stimulated IL‐8 production in KB cells, and IL‐1 receptor agonist significantly inhibited IL‐8 production. Low IL‐1β–containing saliva did not increase IL‐8 production. IL‐1β treatment of KB cells induced activation of MAPK signaling molecules as well as nuclear factor‐kappa B. IL‐1β?induced IL‐8 production was decreased by p38 and extracellular signal‐regulated kinase (ERK) inhibitor treatment. Aloin pretreatment inhibited IL‐1β?induced IL‐8 production in a dose‐dependent manner and inhibited activation of the p38 and ERK signaling pathway. Finally, aloin pretreatment also inhibited saliva‐induced IL‐8 production. Conclusions: Results indicated that IL‐1β in saliva stimulates epithelial cells to produce IL‐8 and that aloin effectively inhibits salivary IL‐1β–induced IL‐8 production by mitigating the p38 and ERK pathway. Therefore, aloin may be a good candidate for modulating oral inflammatory diseases.     

替牙期骨性Ⅲ类错牙合患者颞下颌关节特征的锥形束CT研究

目的:采用锥形束CT(CBCT)研究替牙期骨性Ⅲ类错牙合患者颞下颌关节的影像学特征,探讨Ⅲ类功能状态下,颞下颌关节的生长、改建机制。方法:从就诊于昆明医科大学附属口腔医院正畸科的患者中选取符合纳入标准的替牙期骨性Ⅲ类错牙合患者及骨性Ⅰ类错牙合患者各20名,使用NNT viewer 5.3图像处理软件进行三维重建及线距和角度的测量,并进行统计学分析。结果:替牙期骨性Ⅲ类错牙合患者组和替牙期骨性Ⅰ类错牙合患者组对比结果为:矢状面双侧关节前间隙偏小、双侧关节上间隙偏小、双侧关节结节斜度偏小;冠状面双侧关节内间隙偏小,双侧关节上间隙偏小,双侧关节外间隙偏小,右侧髁状突角度偏小;横截面右侧髁状突前后径偏小。结论:替牙期骨性Ⅲ类错牙合患者颞下颌关节发育不充分,呈现髁状突,关节窝深度,关节结节斜度;冠状面关节内、外间隙均较小的特征。骨性Ⅲ类错牙合患者髁状突在关节窝中处于前置近关节窝顶位置。骨性Ⅲ类错牙合患者颞下颌关节影像学特征与其功能状态相适应。     

Oral cancer: molecular technologies for risk assessment and diagnosis

Purpose: The effective biomarkers related to diagnosis, metastasis, drug resistance and irradiation sensitivity of oral cancers will help the pathologist and oncologist to determine the molecular taxonomy diagnosis and design the individualization treatment for the patients with oral cancers.     

柠檬精油对牙周致病菌抑制作用及其安全性初步研究

目的:探讨柠檬精油对牙周致病菌的体外抗菌活性及对细胞增殖的影响。方法:采用微量液体稀释法测定柠檬精油对Pg、Fn、Aa、Pi的最小抑菌浓度(minimal inhibitory concentration,MIC)及最小杀菌浓度(minimum bactericidal concentration,MBC);以较低浓度的MIC为标准稀释LEO作为实验组,采用MTT法测定柠檬精油对HUVECs的毒性作用,明确抑菌浓度下LEO的安全性。结果:柠檬精油对牙周主要致病菌均有抑菌作用,Pg、Fn、Aa、Pi的MIC分别是9.0 g/L、4.5 g/L、4.5 g/L、9.0 g/L,Aa、Fn的 MBC是9.0 g/L,Pg、Pi的MBC未测得。1/2MIC、1/20MIC浓度的LEO能够抑制人脐静脉内皮细胞的生长,而低于1/200MIC浓度的LEO则对人脐静脉内皮细胞的生长没有影响,其中1/200MIC浓度的LEO作用明显优于0.02%的CHX。结论:体外环境中,柠檬精油对牙周致病菌Pg、Fn、Aa、Pi具有抗菌活性,低浓度应用对机体相对安全。     

Stimulated whole saliva components in children with Down syndrome

The authors report on the components of stimulated whole saliva from children with Down syndrome—including pH, flow rate, sialic acid and protein concentrations, and amylase and peroxidase activity. Saliva samples were collected from 35 children aged 6–10 years. Of the participants, 17 had Down syndrome and 18 did not. To stimulate saliva production, the children chewed a piece of parafilm for 10 minutes before the sample was collected. Soon after collecting the saliva sample, the authors measured pH using a portable pH-meter. Sialic acid levels were determined with a thiobarbituric acid assay. Protein content was determined with Folin's phenol reagent. Amylase was assayed and the authors measured the maltose produced by the breakdown of starch and peroxidase using ortho-dianisidine.
No statistically significant difference was observed in levels of sialic acid (free and total) between the two groups. Protein concentration was about 36% higher in the group with Down syndrome. However, the salivary flow rate, pH, and amylase and peroxidase activities were lower among the children with Down syndrome.     

Clinical and pathological aspects on some odontogenic tumors

Odontogenic tumors constitute a very diverse group of lesions that reflects the complex processes of odontogenesis. Controversies over their classification/subtyping, terminology and diagnosis have been persisted, which has direct bearings on therapeutic and/or prognostic implications.