Porphyromonas gingivalis bacteremia increases the permeability of the blood-brain barrier via the Mfsd2a/Caveolin-1 mediated transcytosis pathway / 国际口腔科学杂志·英文版

Bacteremia induced by periodontal infection is an important factor for periodontitis to threaten general health. P. gingivalis DNA/virulence factors have been found in the brain tissues from patients with Alzheimer's disease (AD). The blood-brain barrier (BBB) is essential for keeping toxic substances from entering brain tissues. However, the effect of P. gingivalis bacteremia on BBB permeability and its underlying mechanism remains unclear. In the present study, rats were injected by tail vein with P. gingivalis three times a week for eight weeks to induce bacteremia. An in vitro BBB model infected with P. gingivalis was also established. We found that the infiltration of Evans blue dye and Albumin protein deposition in the rat brain tissues were increased in the rat brain tissues with P. gingivalis bacteremia and P. gingivalis could pass through the in vitro BBB model. Caveolae were detected after P. gingivalis infection in BMECs both in vivo and in vitro. Caveolin-1 (Cav-1) expression was enhanced after P. gingivalis infection. Downregulation of Cav-1 rescued P. gingivalis-enhanced BMECs permeability. We further found P. gingivalis-gingipain could be colocalized with Cav-1 and the strong hydrogen bonding between Cav-1 and arg-specific-gingipain (RgpA) were detected. Moreover, P. gingivalis significantly inhibited the major facilitator superfamily domain containing 2a (Mfsd2a) expression. Mfsd2a overexpression reversed P. gingivalis-increased BMECs permeability and Cav-1 expression. These results revealed that Mfsd2a/Cav-1 mediated transcytosis is a key pathway governing BBB BMECs permeability induced by P. gingivalis, which may contribute to P. gingivalis/virulence factors entrance and the subsequent neurological impairments.

Porphyromonas gingivalis exacerbates ulcerative colitis via Porphyromonas gingivalis peptidylarginine deiminase / 国际口腔科学杂志·英文版

Ulcerative Colitis (UC) has been reported to be related to Porphyromonas gingivalis (P. gingivalis). Porphyromonas gingivalis peptidylarginine deiminase (PPAD), a virulence factor released by P. gingivalis, is known to induce inflammatory responses. To explore the pathological relationships between PPAD and UC, we used homologous recombination technology to construct a P. gingivalis strain in which the PPAD gene was deleted (Δppad) and a Δppad strain in which the PPAD gene was restored (comΔppad). C57BL/6 mice were orally gavaged with saline, P. gingivalis, Δppad, or comΔppad twice a week for the entire 40 days (days 0-40), and then, UC was induced by dextran sodium sulfate (DSS) solution for 10 days (days 31-40). P. gingivalis and comΔppad exacerbated DDS-induced colitis, which was determined by assessing the parameters of colon length, disease activity index, and histological activity index, but Δppad failed to exacerbate DDS-induced colitis. Flow cytometry and ELISA revealed that compared with Δppad, P. gingivalis, and comΔppad increased T helper 17 (Th17) cell numbers and interleukin (IL)-17 production but decreased regulatory T cells (Tregs) numbers and IL-10 production in the spleens of mice with UC. We also cocultured P. gingivalis, Δppad, or comΔppad with T lymphocytes in vitro and found that P. gingivalis and comΔppad significantly increased Th17 cell numbers and decreased Treg cell numbers. Immunofluorescence staining of colon tissue paraffin sections also confirmed these results. The results suggested that P. gingivalis exacerbated the severity of UC in part via PPAD.

Porphyromonas gingivalis infection promotes mitochondrial dysfunction through Drp1-dependent mitochondrial fission in endothelial cells / 国际口腔科学杂志·英文版

Porphyromonas gingivalis (P. gingivalis), a key pathogen in periodontitis, has been shown to accelerate the progression of atherosclerosis (AS). However, the definite mechanisms remain elusive. Emerging evidence supports an association between mitochondrial dysfunction and AS. In our study, the impact of P. gingivalis on mitochondrial dysfunction and the potential mechanism were investigated. The mitochondrial morphology of EA.hy926 cells infected with P. gingivalis was assessed by transmission electron microscopy, mitochondrial staining, and quantitative analysis of the mitochondrial network. Fluorescence staining and flow cytometry analysis were performed to determine mitochondrial reactive oxygen species (mtROS) and mitochondrial membrane potential (MMP) levels. Cellular ATP production was examined by a luminescence assay kit. The expression of key fusion and fission proteins was evaluated by western blot and immunofluorescence. Mdivi-1, a specific Drp1 inhibitor, was used to elucidate the role of Drp1 in mitochondrial dysfunction. Our findings showed that P. gingivalis infection induced mitochondrial fragmentation, increased the mtROS levels, and decreased the MMP and ATP concentration in vascular endothelial cells. We observed upregulation of Drp1 (Ser616) phosphorylation and translocation of Drp1 to mitochondria. Mdivi-1 blocked the mitochondrial fragmentation and dysfunction induced by P. gingivalis. Collectively, these results revealed that P. gingivalis infection promoted mitochondrial fragmentation and dysfunction, which was dependent on Drp1. Mitochondrial dysfunction may represent the mechanism by which P. gingivalis exacerbates atherosclerotic lesions.

Application of hybrid teaching based on the rain classroom in the teaching of periodontology for undergraduates / 中华医学教育探索杂志

Objective:To study the application and effect of hybrid teaching based on the rain classroom in the teaching of periodontology for undergraduates.Methods:Sixty-four stomatological undergraduates in Phase 101 were selected as experimental group, and 62 in Phase 100 as control group. The hybrid teaching based on the rain classroom were conducted in experimental group, and mind mapping were used before and after class to help students understand and expand the content of class. The traditional teaching was adopted in the control group. SPSS 17.0 was applied to compare the differences between the written test scores and teaching satisfaction evaluation of the two groups. The learning behavior data of the students in experimental group before, during and after class were collected and analyzed.Results:The score of the written test in the experimental group were significantly better than that in the control group ( t=2.97, P<0.05). The result of questionnaire showed that the experimental group was significantly more satisfied with the improvement of lecture efficiency ( t=2.71, P<0.05) and self-learning ability ( t=4.35, P<0.05). The majority (82.55%) of students in the experimental group are in favor of the rain classroom; 89.06% of students finished the preview before class, and 67.19% of them completed the review after class. Conclusion:The hybrid teaching based on the rain classroom can be applied to the teaching of periodontology, which can effectively improve the learning quality and initiative of the students.

The dimension and morphology of alveolar bone at maxillary anterior teeth in periodontitis: a retrospective analysis-using CBCT / 国际口腔科学杂志·英文版

The morphology of the alveolar bone at the maxillary anterior teeth in periodontitis patients was evaluated by cone-beam computed tomography (CBCT) to investigate the distribution of alveolar defects and provide guidance for clinical practice. Ninety periodontitis patients and 30 periodontally healthy individuals were selected to determine the morphology of the alveolar bone at the maxillary anterior teeth according to the degree of bone loss, tooth type, sex and age. The differences in the dimensions between periodontitis patients and healthy individuals were compared, and the distribution of alveolar bone defects was analyzed. A classification system was established regarding the sagittal positions and angulations of the teeth. The buccal residual bone was thicker and the lingual bone was thinner in the periodontitis patients than in the periodontally healthy individuals, and there were differences between the different tooth types, sexes and age subgroups. The buccal undercut was close to the alveolar ridge, while fenestration was reduced and the apical bone height was higher in periodontitis patients than in periodontally healthy individuals. The apical bone height increased with the aggravation of bone loss and age. The proportions of different sagittal positions changed with the aggravation of bone loss. Moreover, the teeth moved more buccally regarding the positions of the maxillary anterior teeth. The morphology of the alveolar bone at the maxillary anterior teeth differed between periodontitis patients and healthy individuals, and the differences were related to the degree of bone loss, tooth type, sex and age.

Effect of nonoperative periodontal treatment on changes of schneiderian membrane thickness of maxillary sinus in the chronic periodontitis patients using cone-beam CT / 中华口腔医学杂志

Objective@#To analysis the effect of nonoperative periodontal treatment on morphological changes of the schneiderian membrane of maxillary sinus in the chronic periodontitis patients by using oro-maxillaofacial cone-beam CT (CBCT) in order to provide the foundation in the diagnosis and treatment of maxillary sinusitis caused by chronic periodontitis.@*Methods@#Totally 30 chronic periodontitis patients with schneiderian membrane thickening [(40.0±5.6) years old (ranged 26-55 years old), 18 males and 12 females] were randomly recruited in Department of Periodontics, School of Stomatology, China Medical University from June 2014 to December 2016. All patients were scanned by CBCT. The probing depth (PD), clinical attachment loss (CAL), plaque index (PLI) and bleeding index (BI) of the maxillary first and second premolars and molars were recorded. All patients received systematic nonoperative periodontal treatment. After six months, patients were reviewed, periodontal indexes and CBCT scanning were recorded. The thickness of the schneiderian membrane of maxillary sinus were analyzed by the software of CBCT. The changes of clinical parameters, parameter dimensional values of membrane thickness before and after treatment were statistically compared by t test.@*Results@#In 30 chronic periodontitis patients, there was no statistically significant difference in the dimension and length of the maxillary sinus mucosa between the right and the left (P>0.05). The dimension of the mucosal thickening was positively correlated with PD and CAL values, and the correlation was statistically significant (P<0.05). Totally 58 maxillary sinus showed mucosal thickening. There were 20 mild thickening cases, and the dimension of mucosal thickening 6 months after treatment [(1.1±0.6) mm] was significantly lower than that before treatment [(2.5±0.7) mm] (P<0.05). There were 30 moderate thickening cases and the dimension of mucosal thickening 6 months after treatment [(2.3±0.6) mm] was significantly lower than that before treatment [(5.8±0.5) mm] (P<0.01). There were 8 severe thickening cases and the dimension of mucosal thickening 6 months after treatment [(4.2±0.4) mm] was also significantly lower than that before treatment [(11.2±1.8) mm] (P<0.01). The periodontal indexes of patients with mild, moderate and severe mucosal thickening in maxillary sinus showed statistically significant difference after treatment compared with before treatment (P<0.05).@*Conclusions@#Nonoperative periodontal treatment has a positive therapeutic significance for improving the schneiderian membrane thickening of maxillary sinus.

The influence of root canal moisture on the canal sealing / 实用口腔医学杂志

Objective: To study the effect of different wetness degrees in the root canal on the canal sealing. Methods: 160 root canal prepared single rooted teeth were divided into 4 groups (n = 40) by the root canal wetness degree (water content, V): (1) 0. 250 ～0. 299, (2) 0. 300 ～ 0. 599, (3) 0. 600 ～ 0. 899 and (4) 0. 900 ～ 1. 199 respectively. 80 teeth were divided into 4 groups (n = 20) for dye leakage test and another 80 for bacterial microleakage test. Zinc oxide paste (ZOP) and AH-Plus (AH-P) with vertical condensation of warm gutta-percha were respectively used to seal the canals in each group of the samples (n = 10) . The length of in vitro tooth dye penetration was measured by stereomicroscope; the time (days) of turbidity in the bacterial leakage model observed and compared. Results: Of all the canals sealed by ZOP or AH-P with the increase of the wetness the dye infiltration length increased significantly (P ＜0. 05) and the days in which the faecal intestine ball infiltrated into the lower chamber of the model was gradually decreased (P ＜0. 05) . Conclusion: The increase of root canal moisture may reduce the sealing of the root canal.

A preliminary study on the effect of histatin 5 inhibiting Porphyromonas gingivalis and Fusobacterium nucleatum co-aggregation / 中华口腔医学杂志

Objective@#To detect the inhibitory ability of histatin 5 on the auto-aggregation of Porphyromonas gingivalis (Pg), and the co-aggregation of Pg with Fusobacterium nucleatum (Fn); and to provide a theoretical basis for the role of oral innate immunity played in the inhibition of chronic periodontitis.@*Methods@#Saliva and supragingival, subgingival plaque samples were collected from 49 chronic periodontitis patients in School of Stomatology, China Medical University and 27 periodontal healthy individuals. Enzyme linked immunosorbent assay was used to assess the amount of histatin 5 in saliva, absolute quantitative real-time PCR (qPCR) was applied to detect the DNA copies of Fn, Pg and total bacteria in supragingival and subgingival plaque samples. The effects of histatin 5 on auto- and co-aggregation were assessed by bacterial adhesion test and scanning electron microscopy. Hemagglutinin gene, arginine-gingipains gene in Pg and FomA gene in Fn were tested by relative qPCR. Independent samples t-test was used to calculate the significance between the experimental group and the control group. P-value<0.05 was considered statistically significant.@*Results@#For chronic periodontitis patients, there was an inverse correlation between the concentration of histatin 5 and Fn and Pg in supragingival plaque samples (r=-0.379, r=-0.624). Similarly, an inverse correlation was also observed between the concentration of histatin 5 and subgingival Fn and Pg, respectively (r=-0.404, r=-0.314). As for periodontally healthy individuals, there was an inverse correlation between the concentration of histatin 5 and supragingival and subgingival Pg (r=-0.572, r=-0.533). Bacterial adhesion test and scanning electron microscopy certified that 25 mg/L histatin 5 inhibited the auto-aggregation of Pg-Pg and the co-aggregation of Pg-Fn. Results of qPCR showed that 25 mg/L histatin 5 up-regulated hemagglutinin gene by (14.52±3.25) fold and down-regulated FomA gene to (0.22±0.10) fold.@*Conclusions@#Histatin 5 could inhibit the auto-aggregation of Pg-Pg and the co-aggregation of Pg-Fn by regulating hemagglutinin gene and FomA gene expression.

Surveillance of antibiotic resistance in clinical isolates from the First Affiliated Hospital of Anhui Medical University during 2017 / 中国感染与化疗杂志

Objective To investigate the antibiotic resistance of clinical isolates in the First Affiliated Hospital of Anhui Medical University during 2017. Methods Antimicrobial susceptibility testing was carried out according to a unified protocol using automated system or Kirby-Bauer method. Results were interpreted according to the breakpoints of CLSI 2017. The data were analyzed by WHONET 5.6 software. Results A total of 6 495 non-duplicate clinical isolates were collected in 2017. There were 1 727 strains (26.6％) of gram-positive bacteria and 4 768 strains (73.4％) of gram-negative bacteria. The most frequently isolated microorganisms were E. coli (19.8％), followed by Klebsiella pneumoniae and Acinetobacter baumannii. The strains were mainly isolated from respiratory tract (37.0％) and urine (23.1％). The prevalence of MRSA and MRCNS in Staphylococcus aureus and coagulase-negative Staphylococcus was 50.1％ and 82.1％, respectively. No Staphylococcus strains were found resistant to vancomycin or linezolid. E. faecalis and E. faecium accounted for 49.9％ and 40.4％ of total Enterococcus isolates. The prevalence of ESBLs-producing strains was 57.6％ in E. coli, 27.1％ in Klebsiella spp. and 33.0％ in Proteus mirabilis. Enterobacteriaceae strains were still highly susceptible to carbapenems antibiotics. The Klebsiella pneumoniae isolates in 2017 showed significantly higher resistance rate to imipenem and meropenem than the strains in 2016. However, Pseudomonas aeruginosa and Acinetobacterbaumannii strains showed lower resistance rates to carbapenems than the strains in 2016. Conclusions The bacterial isolates in 2017 pose serious threat to clinical antibiotic therapy. More attention should be paid to rational use of antimicrobial agents and infection control measures.

Meeting report: a close look at oral biofilms and microbiomes / 国际口腔科学杂志·英文版

The "Biofilms, Microbiomes and Oral Diseases: Challenges and Future Perspectives" symposium jointly organized by Penn Dental Medicine and West China School of Stomatology was held on 30 September 2017 at Penn Wharton China Center (PWCC) in Beijing, China. The topics included the pathogenicity of oral biofilms, novel strategies for the control of biofilm-related diseases, oral microbiome and single-cell approaches, and the link between oral diseases and overall health. Researchers from a number of disciplines, representing institutions from China and Penn Dental Medicine, gathered to discuss advances in our understanding of biofilms, as well as future directions for the control of biofilm-related oral and systemic diseases.

Treatment decision for periodontal patients with history of cancer / 中华口腔医学杂志

Radiotherapy and chemotherapy might change the healing process of periodontal disease by reducing there storability of the periodontal tissues, leading the increase of attachment lose and alveolar bone absorption. The primary periodontal lesions could be aggravated. Therefore, oral screening should be conducted before periodontal treatment, in order to eliminate dental focal infection, to stabilize the oral environment and to prevent and reduce complications after cancer treatment. The patient's general situation should be evaluated before the periodontal treatment too, so as to ensure the patient could tolerate the radiotherapy and chemotherapy in the short interval between diagnosis and treatment of cancer. The periodontal treatment should be more conservative than normal periodontal patients. The indication for tooth extraction in these patients should be less conservative.

The inhibitory effects of chlorhexidine in the development of rat periodontitis models / 实用口腔医学杂志

Objective:To investigate the inhibitory effects of different concentrations of chlorhexidine in the development of peri-odontitis models in rats.Methods:periodontitis models were established by the ligation of bilateral first molars and orally challenge with P.gingivalis W83.0.05%,0.1%,0.2% and 0.5% chlorhexidine were used to wash the periodontal pocket and oral mucosa of the rats.4 weeks later,absolute real time quantitative PCR was used to count the copy of P.gingivalis W83 in rat periodontal pockets.Scanning electron microscopy was used to observe the distribution of P.gingivalis W83 on rat teeth surface.Immunohisto-chemical technique was used to detect the expression of TNF-αin gingival tissue of the rats.Results:0.2% and 0.5% chlorhexi-dine reduced the copy of P.gingivalis W83 on teeth surface and in periodontal pockets (P <0.05);0.1% -0.5% chlorhexidine reduced the expression of TNF-αin gingival tissue (P <0.05).Conclusion:0.1% -0.2% chlorhexidine can inhibit the develop-ment of chronic periodontitis in rats.

The Influence on Systemic Disease by Periodontal Disease / 沈阳医学院学报

The relationship between periodontal disease and systemic diseases more and more get the attention of scholars in recent years. This paper illustrates the influence of periodontal disease on the systemic diseases, which prompt that periodontal disease may be the potential risk factor of causing or aggravating the systemic disease. The treatment of periodontal disease can reduce and prevent the occurrence and development of some systemic diseases,which play an important role in maintaining the whole body health.

Evaluation of the degree and pattern of alveolar bone defect inaggressive periodontitis using cone-beam CT / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the degree and pattern of alveolar bone defect in aggressive periodontitis (AgP) using cone-beam CT (CBCT), and to investigate the distribution of alveolar bone defects in aggressive periodontitis.</p><p><b>METHODS</b>Forty AgP patients (age: 14-36 years, male: 15 cases, female: 25 cases) were selected by simple random method and scanned by CBCT. NNT software was applied to measure the average degree of alveolar bone defects and bone loss types in different regions.</p><p><b>RESULTS</b>In forty AgP patients, 86.6% (3,769/4,352) sites presented moderate and severe alveolar bone defects. In the maxilla, the molar areas presented the heaviest alveolar bone defect [(6.3±0.7) mm], the canine areas showed the lightest bone loss [(4.8±0.8) mm]. In the mandible, the incisal areas presented the heaviest alveolar bone defect [(5.9±0.9) mm], the canine areas showed the lightest bone loss[(5.1±0.7) mm]. The degree of alveolar bone defect in the areas of maxillary canine, maxillary molars, mandibular premolar was significantly different (P<0.05). The degree of alveolar bone defect in mandibular canine and mandibular molars was significantly differenct (P<0.01). The most serious alveolar bone defect was in the mesial side of maxillary molar [(6.9±0.7) mm] and the mesial side of mandibular incisor [(6.5±1.1) mm]. The oblique bone defects were found in the mesial part of the first molars in mandibula [13.6% (42/308)], the first molars in maxilla [12.0% (39/316)] and the first premolar in maxilla [10.8% (34/316)].</p><p><b>CONCLUSIONS</b>The alveolar bone defects of generalized AgP patients were serious. The most serious areas were located in the mesial side of maxillary molars and the mesial side of mandibular incisor.</p>

The effects of smoking-individual-serum on the invasion of F.Nucleatum to KB cells and MMP-1 expres-sion of KB cells / 实用口腔医学杂志

Objective:To investigate the effects of serum from smoking individuals with periodontitis in the process of Fusobocterium.Nucleatum(Fn)invading KB cells and the expression of matrixmetalloproteinase1(MMP1)of KB cells.Methods:Serum was prepared from 10 smokers with periodontitis(group Y),10 nonsmokers with periodontitis(group N)and 5 periodontal healthy nonsmokers(group H).Serum of 200,400 and 800 μl from the subjects was added to the model of Fn invading KB cells respectively and cultured for 24 hours,the cfu of cellinvaded bacteria was estimated by colony counting.MMP1 protein level in culture supernatant wasmeasured by ELISA.Results:In the 800 μl serum groups,the percentage of invaded cfu was 12.59 ±1.27,8.03 ±0.075 and 7.99±0.14 in group Y,N and H(P ＜0.05)respectively,the concentration(μg/L)of MMP1 in the cultrue supernatant of group Y,Nand H was 400.04 ±21.02,252.57 ±18.89 and 262.47 ±35.29(P ＜0.05)respectively.In the 200 μl and 400 μl serum groups,no significant difference was detected in invasion cfu of Fn in KB cells and MMP1 secrition of KB cells among Y,N and H groups(P>0.05).Conclusion:Higher doses of smokingserum might play a role in the course of Fn invading KB cells and promote the expression of MMP1 secretion from KB cells.

Effect of smokers'sera on Porphyromonas gingivalis internalizing KB cells and the expression of matrix metalloproteinase-1, -9 and tissue inhibitor of metalloproteinase-1 / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of serum from smoking individuals or non-smoking individuals with periodontitis on Porphyromonas gingivalis (Pg) internalizing KB cells, and the expression of matrix metalloproteinase(MMP)-1, MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1) in the culture supernatant of KB cells.</p><p><b>METHODS</b>The venous blood of 20 periodontitis patients' (10 smoking and 10 non-smoking) was extracted under the informed consent and centrifuged for serum. The smoking-individual serum (Y group) and non-smoking-individual (N group) serum were added to the model of Pg internalizing KB cells for 12 hours, plated on brain-heart infusion (BHI) and incubated anaerobically at 37 °C for 5 days. The colony forming units (CFU) of cell-invasive bacteria were estimated by colony counting. MMP-1, MMP-9 and TIMP-1 protein levels in culture supernatant were determined by enzyme-linked immunosorbent assay(ELISA) in the two groups following co-culture of Pg with KB cells for 12 hours.</p><p><b>RESULTS</b>The CFU were (11.2 ± 1.1)×10(4), (12.6 ± 1.2)×10(4), (44.7 ± 1.3)×10(4) CFU/ml when adding 200, 400, 800 µl Y-group serum to the model of Pg co-culture with KB cells and when the serum was extracted from N group, the CFU were (33.6 ± 1.4)×10(4),(38.9 ± 1.1)×10(4), (11.2 ± 1.2)×10(4) CFU/ml respectively. When 200, 400, 800 µl Y group-serum was added to co-culture fluid of Pg internalizing KB cells, the concentrations of MMP-1 secreted from KB cells were (107.2 ± 21.5), (165.9 ± 20.2), (434.4 ± 48.0) µg/L respectively, the concentrations of MMP-9 were (3.99 ± 0.29), (4.21 ± 0.61), (5.62 ± 0.47) µg/L respectively, the concentrations of TIMP-1 were (401.3 ± 12.7), (418.3 ± 28.5), (637.3 ± 37.3) µg/L. When the serum (200, 400, 800 µl) extracted from N group, the concentration of MMP-1 and MMP-9 secreted by KB cell were (77.6 ± 10.8), (84.7 ± 10.2) and (98.2 ± 9.7) µg/L and (3.84 ± 0.52), (4.02 ± 0.68), (4.25 ± 0.37) µg/L, respectively. The concentration of TIMP-1 were (67.3 ± 26.9) , (89.4 ± 22.7) and (78.2 ± 16.5) µg/L secreted by KB cells in the course of Pg internalized KB cell. With the increasing of Y group-serum, the more MMP-1, MMP-9 and TIMP-1 were secreted by KB cells(P < 0.05). When 800 µl Y group-serum was added compared with N group-serum to the Pg co-culture with KB model, the more MMP-1, MMP-9 and TIMP-1 were secreted by KB cells(P < 0.05), when 400 µl Y group-serum was added compared with N group-serum to the Pg co-culture with KB model, the more MMP-1 and TIMP-1 were secreted by KB cells (P < 0.05).</p><p><b>CONCLUSIONS</b>The smoking-serum might enhance Pg internalizing KB cells and enhance the expression of MMP-1, MMP-9 and TIMP-1 secreted from KB cells. The local microenvironment of smoking individual may contribute to the recurrence and progression of chronic periodontitis.</p>

Self-reported periodontal health for epidemiological survey of periodontitis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the prediction effect of the self-reported periodontal health on moderate and severe chronic periodontitis and its feasibility.</p><p><b>METHODS</b>A total of 330 subjects from five districts of Shenyang city attended the survey.Each subject answered questions about self-reported periodontal health and risk factors of periodontitis and was given a periodontal examination. The predictiveness was assessed by logistic regression modeling measuring receiver operator characteristic (ROC) curve and area under curve (AUC), sensitivity and specificity.</p><p><b>RESULTS</b>Self-reported periodontal health for the prediction of moderate and severe chronic periodontitis was moderately effective, with AUC of 0.837, sensitivity of 74.8%, specificity of 71.3%.Self-reported periodontal health combined with risk factors of periodontitis was highly effective in prediction of moderate and severe chronic periodontitis, with AUC of 0.912, sensitivity of 82.1%, specificity of 85.4%.</p><p><b>CONCLUSIONS</b>Self-reported periodontal health can be used for epidemiological investigation of moderate and severe chronic periodontitis.Self-reported periodontal health combined with risk factors of periodontitis can improve the accuracy of the results of the survey.</p>

Construction PG0839 gene-defective mutant of Porphyromonas gingivalis / 华西口腔医学杂志

<p><b>OBJECTIVE</b>In order to determine the function of PG0839 gene from Porphyromonas gingivalis (P. gingivalis) W83 strains, we intended to create a mutant in the PG0839 gene by homologous recombination.</p><p><b>METHODS</b>1 584bp PG0839 gene fragment was amplified, digested by BamH I and EcoR I, purified and ligated to pUC19. The recombinant plasmid was designated as pPG0839-1. The erm cassette (2 101 bp) was inserted into the EcoR V restriction site of the PG0839 gene. The resultant recombinant plasmid, pPG0839-2, was used as a donor in the electroporation of P. gingivalis W83. After electroporated and selected on erythromycin brain heart infusion plates, a single colony was collected and designated as PG0839 gene-defective mutant.</p><p><b>RESULTS</b>A mutant in PG0839 gene was created by insertional inactivation, and inactivation of PG0839 gene was confirmed by restriction endonuclease digestive, sequencing, polymerase chain reaction (PCR) and reverse transcription PCR.</p><p><b>CONCLUSION</b>A PG0839 gene-defective mutant was created successfully.</p>

Effects of Porphyromonas gingivalis on focal adhesive components paxillin and FAK of gingival epithelial cells / 实用口腔医学杂志

Objectives: To explore the destructive mechanism of P.gingivalis on periodontium and to better understand the pathogenic effects of P.gingivalis fimbriae. Methods:Western blotting was used to detect the degradation effects of P.gingivalis ATCC 33277 and its fimA-deficient mutant on focal adhesion components paxillin and focal adhesion kinase (FAK) of Hela cells and immortalized gingival epithelial cells (IHGE cells). Results:P.gingivalis ATCC 33277 wild strain and its fimA-deficient mutant induced degradation of paxillin and FAK both in Hela cells and in IHGE cells. fimA-deficient mutant had a remarkable weaker degradation ability than the wild strain. In IHGE cells, paxillin and FAK were degraded in a time-and MOI-dependent manner. Conclusion:P.gingivalis fimbriae-mediated adhesion and invasion to epithelial cells may promote the degradation of focal adhesion components. IHGE cells may be more suitable for the study of periodontal pathogens than Hela cells.

Role of Porphyromonas gingivalis invasion on monocyte adhesion to endothelium / 中华微生物学和免疫学杂志

Objective To observe the role of Porphyromonas P.gingivalis(P.gingivalis)invasion on monocyte adhesion to endothelium and its effect on the intercellular adhesion molecule-1(ICAM-1)produc-tion in endothelial cells.Methods A cell culture model of human umbilical vein endothelial cells (HUVEC) Was used in vitro.The adhesion of monocytes to HUVEC was detected by Rose Bengal staining with or without P.gingivalis invasion.The ICAM-1 mRNA expression in HUVEC Was determined by RT-PCR or quantikine mRNA colorimetric quantification kits.Cell surface protein of ICAM-1 in HUVEC was de-termined by Western blot with or without P.gingivalis invasion.Results The adhesion of monocyte to endo-thelium and expression of ICAM-1(both at mRNA and protein level)were found to be enhanced by P.gingi-valis invasion.Pretreatment of HUVEC with anti-ICAM-l antibody partly abolished the increase in monocyte adhesion to endothelium.Furthermore.the effect of virulent strain W83 was stronger than that of avirulent strain ATCC33277.Condusion P.gingivalis plays an important role in monocyte-endothelium adhesion partly through up regulation of ICAM-1,which may be one of the pathologic mechallisms in atherosclerosis.