[Research Progress in Oral Diseases and Oral Microbiota of Organ Transplant Patients].

Organ transplantation is an effective treatment for end-stage organ diseases. However, organ transplant recipients are susceptible to a wide variety of oral diseases, including gingival enlargement, periodontitis, oral mucosal diseases, oral malignant tumors, and dental caries. Oral microbiota may have played an important role in the organ transplant patients' increased susceptibility to oral diseases and is associated with adverse events after organ transplantation, which is gradually gaining more attention among scholars. We, herein, reviewed the common oral diseases, including periodontal tissue diseases, oral mucosal diseases, oral malignant tumors, and dental caries in organ transplantation patients. Furthermore, we discussed the characteristic changes in the oral microbiota of organ transplantation patients and the influencing factors of these changes. In-depth study of oral microbiota of organ transplant patients provides a reference for the prevention and treatment of relevant diseases after organ transplantation and serves an important role in oral and systemic health management of organ transplant patients.

[Research Progress in the Association between Amino Acid Metabolism of Oral Microorganisms and Host Cells and Oral Diseases].

Amino acids, the substrate of protein synthesis, are an important source of energy and nutrition, second only to glucose. Previous studies have found that both microorganisms and their host cells can metabolize amino acids, and the metabolites are widely involved in the regulation of various biological processes, including inflammation and immune response. Exploring the changes in amino acid metabolism during the pathogenesis and progression of diseases has become a new hot topic of research. We summarized in this review the research progress in the pathogenesis and progression of common oral diseases, including dental caries, periodontal diseases, Sjögren's syndrome, and even oral tumors, related to metabolism pathways of amino acids, especially tryptophan and arginine, and their metabolites, attempting to provide a theoretical basis for enhancing understanding of the pathogenic mechanism of the oral diseases, as well as guidance for clinical treatment.

In vitro effect of Porphyromonas gingivalis combined with influenza A virus on respiratory epithelial cells.

OBJECTIVE: Respiratory epithelial cells are the first natural barrier against bacteria and viruses; hence, the interactions among epithelial cells, bacteria, and viruses are associated with disease occurrence and development. The effect of co-infection by P. gingivalis and influenza A virus (IAV) on respiratory epithelial cells remains unknown. The aim of this study was to analyze in vitro cell viability and apoptosis rates in respiratory epithelial A549 cells infected with P. gingivalis or IAV alone, or a combination of both pathogens. DESIGN: A549 cells were first divided into a control group, a P. gingivalis group, an IAV group, and a P. gingivalis + IAV group, to examine cell viability and apoptosis rates, the levels of microtubule associated protein 1 light chain 3 B (LC3-II), microtubule associated protein 1 light chain 3A (LC3-I), and sequestosome 1 (P62), and the formation of autophagosomes. The autophagy inhibitor, 3-methyladenine (3MA), was used to assess autophagy and apoptosis in A549 cells infected with P. gingivalis or IAV. RESULTS: An MTT assay revealed that cell viability was significantly lower in the IAV group than in the P. gingivalis + IAV group (P < 0.05). Flow cytometry indicated that the apoptosis rate was significantly higher in the IAV group than in the P. gingivalis + IAV group (P < 0.05). The fluorescence levels of GFP-LC3 increased significantly, the LC3-II/LC3-I ratio was significantly higher, and the P62 protein levels were statistically lower in the P. gingivalis + IAV group compared with the IAV group (all P < 0.05). Western blotting revealed that the LC3- II/LC3-I ratio was significantly lower, and caspase-3 levels were significantly higher in the 3MA + P. gingivalis + IAV group compared to the P. gingivalis + IAV group (all P < 0.05). CONCLUSION: In vitro studies showed that infection by P. gingivalis combined with IAV temporarily inhibited apoptosis in respiratory epithelial cells, and this may be related to the initiation of autophagy.

Resveratrol enhances the functionality and improves the regeneration of mesenchymal stem cell aggregates.

Mesenchymal stem cell (MSC)-based regeneration, specifically cell aggregate or cell sheet engineering, is a promising approach for tissue reconstruction. Considering the advantages of ease of harvest and lack of immune rejection, the application of autologous MSCs (i.e., patients' own MSCs) in regenerative medicine has developed considerable interest. However, the impaired cell viability and regenerative potential following MSCs impacted by disease remain a major challenge. Resveratrol (RSV) exhibits reliable and extensive rejuvenative activities that have received increasing clinical attention. Here, we uncovered that resveratrol enhances the functionality and improves the regeneration of mesenchymal stem cell aggregates. Periodontal ligament MSCs (PDLSCs) from normal control subjects (N-PDLSCs) and periodontitis patients (P-PDLSCs) were investigated. Compared to N-PDLSCs, P-PDLSCs were less capable of forming cell aggregates, and P-PDLSC aggregates showed impaired osteogenesis and regeneration. These functional declines could be mimicked in N-PDLSCs by tumor necrosis factor alpha (TNF-α) treatment. Notably, a TNF-α-induced functional decline in N-PDLSC aggregates was rescued by RSV application. More importantly, in both N-PDLSCs and P-PDLSCs, RSV promoted cell aggregate formation and improved their osteogenic potential. Furthermore, as proven ectopically in vivo, the tissue regenerative capability of P-PDLSC aggregates was also enhanced after RSV treatment during aggregate formation in vitro. Finally, in a rat in situ regeneration model, we successfully applied both N-PDLSC aggregates and P-PDLSC aggregates to repair periodontal defects upon long-term functional improvements by RSV preconditioning. Together, our data unravel a novel methodology for using pharmacology (i.e., RSV)-based cell aggregate engineering to improve the functionality and facilitate the regeneration of MSCs from both healthy and inflammatory microenvironments, shedding light on improving the application of autologous MSC-mediated regenerative medicine.

Preventive effects of the novel antimicrobial peptide Nal-P-113 in a rat Periodontitis model by limiting the growth of Porphyromonas gingivalis and modulating IL-1ß and TNF-α production.

BACKGROUND: P-113 (AKRHHGYKRKFH-NH2) is a 12-amino-acid histidine-rich peptide derived from histatin 5 that is highly degradable in high salt concentrations and biological fluids such as serum, plasma and saliva. Nal-P-113, a novel antimicrobial peptide whose histidine residues are replaced by the bulky amino acids ß-naphthylalanine, causes the antimicrobial peptide to retain its bactericidal activity even in physiological environments. This study evaluated the effect of the novel antimicrobial peptide Nal-P-113 in a rat periodontitis model and the mechanisms of action of Nal-P-113 for suppressing periodontitis. METHODS: Periodontitis was induced in mandibular first molars in rats receiving a ligature and infected with Porphyromonas gingivalis. Animals were randomly divided into six groups: a, P. gingivalis W83 alone; b, P. gingivalis W83 with 6.25 µg/mL of Nal-P-113; c, P. gingivalis W83 with 25 µg/mL of Nal-P-113; d, P. gingivalis W83 with 100 µg/mL of Nal-P-113; e, P. gingivalis W83 with 400 µg/mL of Nal-P-113; and f, control without P. gingivalis W83 or Nal-P-113. Morphometric analysis was used to evaluate alveolar bone loss. Microbiological assessment of the presence of Porphyromonas gingivalis and total bacteria was performed using absolute quantitative real-time PCR and scanning electron microscopy. Gingival tissue was collected for western blot and immunohistochemical assays of IL-1ß and TNF-α levels. RESULTS: Alveolar bone loss was inhibited by 100 µg/mL or 400 µg/mL of Nal-P-113 compared to the control group (P < 0.05). Lower amounts of P. gingivalis and total bacteria were found in groups d and e compared with group a (P < 0.05). A decrease in the levels of IL-1ß and TNF-α was detected in group d and group e compared to the control group (P < 0.05). The amount of P. gingivalis was positively correlated with IL-1ß and TNF-α expression in periodontal tissue (P < 0.05). CONCLUSIONS: Nal-P-113 exhibited protective effects on Porphyromonas gingivalis-induced periodontitis in rats by limiting the amount of bacteria and modulating IL-1ß and TNF-α production. The use of Nal-P-113 in vivo might serve as a beneficial preventive or therapeutic approach for periodontitis.

A new phenyldilactone from Lespedeza cuneata.

A new phenyldilactone, maysedilactone B (1), together with twenty known compounds, were isolated from the aerial parts of Lespedeza cuneata. The structural elucidation of the isolated compounds was primarily based on HR-ESI-MS, IR and 1D and 2D NMR analyses. Compounds 1-8 and 15-21 were tested for cytotoxicity against four human tumor cell lines (A549, HCT116, SKOV3, and HepG2) using MTT method in vitro, while no significant activities were observed for the evaluated compounds.

Efficacy of a novel antimicrobial peptide against periodontal pathogens in both planktonic and polymicrobial biofilm states.

Streptococcus gordonii, Fusobacterium nucleatum and Porphyromonas gingivalis represent the early, middle and late colonizers of the bacterial accretion in dental plaque biofilms. These sessile communities constitute a protected mode of growth that promotes survival in a hostile environment. This study describes a novel and unrecognized role for a synthetic cationic antimicrobial peptide, Nal-P-113, which inhibits and kills periodontal bacteria in planktonic state, inhibits the formation of biofilms and eradicates polymicrobial biofilms. Nal-P-113 is also stable in saliva, serum and saline solution. At a concentration less than 320 µg/mL which is harmless to normal oral cells, Nal-P-113 can kill bacteria in planktonic state. At a concentration of antimicrobial peptide Nal-P-113 (1280 µg/mL) which only causes slight damages to normal oral cells is needed to kill bacteria in biofilm state. It is worth mentioning that this concentration of Nal-P-113 is harmless to rat oral mucosa compared to chlorhexidine. The mechanism of Nal-P-113 inhibiting and killing periodontal bacteria might rely on the abilities to permeabilize and/or to form pores within the cytoplasmic membranes, thus causes the death of bacteria. Here, we provided a novel and stable antimicrobial peptide with very low mammalian cytotoxicity, which can inhibit and kill periodontal bacteria in both planktonic and polymicrobial biofilm states. STATEMENT OF SIGNIFICANCE: Nal-P-113 is a potent antimicrobial peptide with strong antimicrobial ability, improved deficiency compared with other antibacterial peptides, and remains stable in phosphate buffered saline, saliva, brain-heart infusion medium and bovine calf serum. Nal-P-113 exhibits a broad spectrum of bacteriocidal activity with excellent eradicating capability on oral pathogens and the respective biofilms. In this study, we used propidium iodide staining, scanning electron microscopy and transmission electron microscopy to confirm that Nal-P-113 can perforate plasmalemma thereby resulting in the death of oral pathogens and disintegrate the respective biofilms. Nal-P-113 also showed effective anti-plaque biofilms and cytotoxicity in the rat periodontitis model. No adverse effects can be observed on the gingivomucosa tissue. In short, the antimicrobial peptide Nal-P-113 presented to be an effective yet have low mammalian cytotoxicity agent with potential application in the clinic. This study provides a proof of concept in applying antimicrobial peptides in the clinical perspective.

Periodontal status of Pakistani orthodontic patients

The objective of this study was to evaluate and compare the periodontal status of orthodontic patients and non-orthodontic patients, aged 15–28 years, of both genders. The cross-sectional study included 100 orthodontic and 100 non-orthodontic patients evaluated using a Community Periodontal Index for Treatment Need (CPITN) probe on the index teeth. A questionnaire was distributed to the participants to assess and evaluate the use of oral hygiene aids. The data were analyzed using SPSS version 17, and various comparisons were performed using the chi-square test. The study revealed that there was a statistically significant association in CPITN scores between the orthodontic and non-orthodontic patients (p < 0.01). The study showed that patients undergoing orthodontic treatment have increased plaque accumulation and probing depth resulting in periodontal tissue destruction. Proper oral hygiene practices and interdental aids should be employed to control plaque.

[17-ß estradiol promotes the expression of interleukin-6 in human periodontal ligament cells infected with Porphyromonas gingivalis].

OBJECTIVE: To investigate the effects of 17-ß estradiol (E(2)) and Porphyromonas gingivalis (Pg) W83 on the expression of interleukin (IL)-6 and IL-8 in human periodontal ligament cells (hPDLC). METHODS: Primary cultures of hPDLC were established and the cells of passage four were treated with 10(-10) mol/L E(2), 10(-7) mol/L E(2) or PgW83 individually or E(2) combined with PgW83. The expression levels of IL-6 and IL-8 protein at 12 h and 24 h were measured with enzyme-linked immunosorbent assay and the levels of mRNA at 24 h were detected with real-time reverse transcriptase polymerase chain reaction. RESULTS: The expression level of IL-6 reached (2482.88 ± 26.53) ng/L in hPDLC treated with Pg at multiplicity of infection (MOI) of 100 for 24 h, which was significantly higher than that in hPDLC treated with Pg at MOI of 10:1 [(734.09 ± 87.90) ng/L, P = 0.000], the controls [(425.8 ± 77.25) ng/L, P = 0.000] and that in hPDLC treated with Pg at MOI of 100 for 12 h [(1157.50 ± 234.65) ng/L, P = 0.000]. The expression level of IL-8 reached (4965.81 ± 1072.55) ng/L in hPDLC treated with Pg at MOI of 100 for 24 h, which was significantly higher than that in hPDLC treated with Pg at MOI of 10 [(803.51 ± 162.08) ng/L, P = 0.007], the controls [(400.75 ± 2.27) ng/L, P = 0.005] and that in hPDLC treated with Pg at MOI of 100 for 12 h [(1431.12 ± 82.78) ng/L, P = 0.001]. E(2) did not show remarkable effect on the expressions of IL-6 and IL-8. E(2) combined with Pg (MOI = 100:1) significantly promoted the expression levels of IL-6 at 24 h while did not influence those of IL-8. The relative mRNA level of IL-6 in hPDLC treated with 10(-10) mol/L E(2) or 10(-7) mol/L E(2) combined with Pg were 0.49 ± 0.15 (P = 0.021)and 0.53 ± 0.16 (P = 0.036) individually, which were significantly higher than that treated with Pg alone, 0.19 ± 0.06. The protein level of IL-6 in hPDLC treated with 10(-10) mol/L E(2) or 10(-7) mol/L E(2) combined with Pg were (5512.66 ± 1022.07) ng/L (P = 0.012) and (6988.78 ± 2279.13) ng/L (P = 0.000) individually, which were significantly higher than that treated with Pg alone, (3138.46 ± 183.72) ng/L. CONCLUSIONS: PgW83 significantly increased the expression levels of IL-6 and IL-8 in hPDLC in a dose-and time-dependent manner. Without the infection of periodontal pathogens, estrogen may exert no effect on the expression of IL-6 and IL-8 while it may promote the expression of IL-6 in hPDLC when combined with Pg, which may in turn promote the process of periodontal inflammation.

[Effect of PG0839 gene of Porphyromonas gingivalis on inflammatory cytokine in human oral epidermoid carcinoma KB cell].

OBJECTIVE: To investigate the effect of PG0839 gene form Porphyromonas gingivalis (Pg) on inflammatory cytokine expression in human oral epidermoid carcinoma KB cell. METHODS: A mutant in the PG0839 gene of Pg was created by insertional inactivation. Group 1 was chanllenged with PgW83 strain, group 2 with PG0839-defective mutant, and the control group with Dulbecco's modified Eagle's medium only. KB cells were co-cultured with presence of bacteria for 24 h. At the time point of 0.5, 2, 6, 12 and 24 h, cells were stored in Trizol. The mRNA expression of interleukin-1ß (IL-1ß) and Toll like recepector-4 (TLR-4) was examined by reverse transcription polymerase chain reaction. RESULTS: At 2 h and 6 h, IL-1ß mRNA expression was lower in group 2 than in group 1 (2 h: 0.31 ± 0.11 versus 0.95 ± 0.48, P < 0.05; 6 h: 0.57 ± 0.20 versus 1.29 ± 0.55, P < 0.05). At 0.5 h and 6 h, TLR-4 mRNA expression was lower in group 2 than in group 1 (0.5 h: 0.20 ± 0.09 versus 0.58 ± 0.09, P < 0.05; 6 h: 0.34 ± 0.04 versus 0.71 ± 0.18, P < 0.05). CONCLUSIONS: PG0839 gene may play an important role in Pg-induced inflammatory effects of KB cell.

[A study of frequency of TNF alpha gene with type 2 diabetes mellitus with chronic periodontitis].

PURPOSE: To detect the frequency of TNF alpha gene in patients of type 2 diabetes mellitus with chronic periodontitis, periodontitis without any systemic diseases and healthy controls. METHODS: The case series were consisted of 112 patients with moderate, severe type 2 diabetes mellitus with chronic periodontitis, 99 patients with moderate, severe periodontitis without any systemic disease, 50 age- and gender-matched subjects with healthy periodontal conditions were enrolled. Clinical parameters were measured and recorded including probing depth(PD), clinical attachment loss(CAL), bleeding index(BI), and tooth movement(TM). The polymorphism of TNF-α-308 genotype (TNF1/2) was examined after electrophoresis on agarose gel and ethidium bromide staining. The difference between the case and healthy groups was analysed by Chi-square test, the difference in clinical index among groups which had different allele was analyzed for ANOVA with SPSS13.0 software package. RESULTS: We divided DM and CP groups into moderate and severe groups. There were significant difference between severe DM group and severe, moderate CP group, moderate DM group and chronic periodontitis of severe,moderate group. The probing depth and clinical attachment loss of the patients who took TNF-α-308 allele II were significantly higher than the patients who took TNF-α-308 allele I in DM and CP group. CONCLUSIONS: TNF-α-308 allele II might increase the susceptivity of periodontitis in population. TNF-α-308 allele II may play an important role in synergistic reaction of periodontitis and type 2 diabetes.

[Effect of non-surgical periodontal therapy on glycemic control and the level of serum IL-6 in type 2 diabetic patients with chronic periodontitis].

OBJECTIVE: To evaluate the effect of non-surgical periodontal therapy on periodontal status, glycemic control and the level of serum interleukin (IL)-6 in type 2 diabetic patients with chronic periodontitis (DMCP). METHODS: Fifty-five DMCP and 55 systemically healthy patients with chronic periodontitis (CP) were recruited in this study. The diabetes were classified into two groups, the well-controlled group [glycated hemoglobin (HbA1c) < 7.00%] and the poorly controlled group (HbA1c ≥ 7.00%). All subjects received non-surgical periodontal therapy. Periodontal clinical parameters including periodontal probing depth(PD), attachment loss (AL), bleeding index (BI) and plaque index (PLI) were recorded at baseline, 6 weeks and 3 months after the treatment. Fasting plasma glucose (FPG), HbA1c and the concentration of serum IL-6 were measured. RESULTS: At 6 weeks and 3 months after treatment, PD, AL, BI, PLI and the concentration of serum IL-6 of both groups significantly reduced (P < 0.05). The level of IL-6 in diabetic patients reduced significantly from (3.47 ± 0.33) ng/L to (3.21 ± 0.66) ng/L and to(3.03 ± 0.54) ng/L. The HbA1c of diabetic patients reduced significantly 3 months after treatment [(6.80 ± 1.21%] compared with the baseline [(7.35 ± 1.73)%, P < 0.05]. HbA1c of the poorly controlled group reduced significantly (P < 0.05), while HbA1c of the well-controlled diabetes did not show any apparent reduction (P > 0.05). CONCLUSIONS: Non-surgical periodontal therapy can effectively reduce the concentration of serum IL-6, thereby improving glycemic control in type 2 diabetes patients with chronic periodontitis. However, there was no any significant reduction of HbA1c in the well-controlled diabetes.

[A survey on the periodontal status in type 2 diabetic patients].

OBJECTIVE: To investigate the type 2 diabetic patient's periodontal condition and to analyze the influencing factors of periodontitis. METHODS: A total of 182 type 2 diabetic patients were included in the survey and requested to fill out a questionnaire, and their periodontal status was evaluated by measuring probing depth (PD), attachment level (AL), sulcus bleeding index (SBI), simplified oral hygiene index (OHI-S). RESULTS: The prevalence of periodontitis in this group of patients was 96.7% (176/182), including 20 patients with mild periodontitis, 156 with moderate to advanced periodontitis. The mean PD and AL of the 182 patients were (2.92 +/- 0.67) mm and (2.87 +/- 1.31) mm. At least one tooth was lost in 57.1% (104/182) of the patients. The factors related to periodontitis were age, gender, smoking, living in town or country, and 2 h plasma glucose of oral glucose tolerance test (OGTT). There was no relationship between the severity of periodontitis and education level. The majority of patients did not receive any periodontal therapy. CONCLUSIONS: Periodontal status was bad in patients with type 2 diabetes. It is important to develop an education program on oral health for type 2 diabetic patients.

[Screening and analysis of multi-alleles in generalized aggressive periodontitis].

OBJECTIVE: To detect the susceptible alleles in generalized aggressive periodontitis patients and healthy controls and to analyze the effect of multi-alleles on the occurrence and development of generalized aggressive periodontitis. METHODS: Polymerase chain reaction and cleavage were used for detecting the frequencies of five susceptible genetic polymorphisms in generalized aggressive periodontitis patients and healthy controls. The results were analyzed by Z-score test and mean square analysis. RESULTS: The frequencies of homozygous for HLA-DRB1* 1501 allele, TNF-A-308 allele II, IL-1B(+3953) allele II, vitamin D receptor allele A, T, estrogen receptor allele X in generalized aggressive periodontitis patients were higher than those in healthy controls. The persons who took more than three susceptible alleles (including three susceptible alleles) had more severe periodontal conditions than the ones who took less than three susceptible alleles (not including three susceptible alleles). CONCLUSIONS: HLA-DRB1 * 1501 allele, TNFA-308 allele II, IL-1B(+3953) allele II, vitamin D receptor allele A, T, estrogen receptor allele X are susceptible alleles in generalized aggressive periodontitis. Carrying more than three susceptible alleles has a great effect on the occurrence and development of generalized aggressive periodontitis.

[The relativity between chronic periodontitis and the genetic polymorphisms of vitamin D receptor and estrogen receptor].

OBJECTIVE: To investigate the relationship between chronic periodontitis and the genetic polymorphisms of vitamin D receptor gene and estrogen receptor gene. METHODS: Clinical parameters including probing depth, clinical attachment loss, sulcus bleeding index and tooth movement were measured by fluoride probe. Genomic DNA from peripheral venous blood was extracted with saturant sodium chloride, and PCR-restriction fragment length polymorphism was applied to examine the Apa I, Bsm I, Taq I polymorphisms of the vitamin D receptor genes and the Xba I and Pvu II polymorphisms of the estrogen receptor genes. The results were analyzed by Z-score test and mean square analysis. RESULTS: Forty-three point four percent of chronic periodontitis patients took vitamin D receptor BB genotype, the rate in healthy controls was 30.0%. 39.6% of chronic periodontitis patients took estrogen receptor XX genotype, the rate in healthy controls was 20.0%. The people who took BBXX genotype had the worst periodontal conditions among all chronic periodontitis patients. CONCLUSIONS: Vitamin D receptor allele B and estrogen receptor allele X are susceptible alleles for chronic periodontitis. The synergistic effects of the two receptor susceptible alleles may promote chronic periodontitis.

[The role of Porphyromonas gingivalis invasion on E-selectin expression in endothelial cells].

PURPOSE: To evaluate the role of Porphyromonas gingivalis(P.gingivalis)ATCC 33277 and W83 invasion on the mRNA and protein expression of E-selectin in vascular endothelial cells. METHODS: A cell culture model of human umbilical vein endothelial cells was used in vitro. E-selectin mRNA was measured by reverse transcription-polymerase chain reaction; the protein expression of E-selectin was detected by Western blot assay. The data was analyzed with SAS 8.12 software package for repeated measures ANOVA. RESULTS: P.gingivalis not only enhanced mRNA expression of E-selectin, but also enhanced the protein level of E-selectin.Compared to the control, the relative mRNA expression of E-selectin after P.gingivalis ATCC 33277/W83 invasion at 4-hour, 8-hour, 24-hour or exposed to TNFalpha was 294.0%/326.4%(P<0.05),179.3%/224.6%(P<0.05),126.7%/128.3% and 365.5%(P<0.05), respectively. The relative protein expression of E-selectin was 295.4%/343.6% (P<0.05), 386.3%/394.3%(P<0.05), 238.7%/296.4% (P<0.05) and 413.8% (P<0.05), respectively. The effect of P.gingivalis virulent strain W83 was more strongly than that of avirulent strain ACTT 33277. CONCLUSION: P.gingivalis plays an important role in the pathogenesis and progression of atherosclerosis partly through upregulation of E-selectin.

[Porphyromonas gingivalis vesicle induced cellular inflammatory responses of gingival epithelial cells in vitro].

OBJECTIVE: To establish the model of cellular inflammatory responses of gingival epithelial cells in vitro induced by Porphyromonas gingivalis vesicle and to probe into the pathogenesis of Porphyromonas gingivalis in periodontitis. METHODS: The effect of Porphyromonas gingivalis vesicle on prostaglandin E(2) (PGE(2)) production of gingival epithelial cells was detected by ELISA and the effects of Porphyromonas gingivalis vesicle on cyclooxygenase-2 (COX-2), interleukin (IL)-6 and IL-8 mRNA expression in gingival epithelial cells were determined by Real-time reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Porphyromonas gingivalis vesicle dose-dependently induced PGE(2) production and up-regulated COX-2, IL-6 and IL-8 mRNA expression in gingival epithelial cells significantly. CONCLUSIONS: Cellular inflammatory responses of gingival epithelial cells induced by Porphyromonas gingivalis vesicle may contribute to the initiation and progression of periodontitis.

Epidemiology and preventive direction of periodontology in China.

OBJECTIVE: The aim of this work was to estimate the present periodontal problems of people in China, based on an epidemiological investigation of adults. MATERIAL AND METHODS: The data were collected from the northwest, southwest, northeast and east regions (400 subjects from each region) of China. All subjects were over 25 years of age. About half of the subjects were farmers and about half were urban professionals. Everyone was asked to fill out a questionnaire and to undergo a professional oral examination. Periodontal health status was evaluated by a simplified oral hygiene index (OHI-S), gingival index (GI), bleeding on probing (BOP), probing pocket depth (PD), clinical attachment loss (CAL), and tooth mobility. RESULTS: Of the 1590 subjects enrolled in this investigation, 45.7% were male, 45.5% were farmers, and the remaining were urban professionals, and 27.7% of the subjects were smokers. There was a significant difference in the educational background but not smoking between the rural and urban groups. While 34.9% of the subjects in the urban group brushed only once per day, 56.1% of the subjects in the rural group did so. The prevalence of bleeding during brushing was 71.1%, while about 61.4% of the subjects know nothing about scaling. All periodontal indices were significantly higher in males than in females and higher in the rural group than in the urban group. PD, CAL and tooth mobility increased with age. The percentage of sites with CAL>3 mm in the rural group (49.5%) was significantly higher than that in the urban group (37.5%). Both current and former smokers showed increased CAL than non-smokers. CONCLUSION: Gingivitis and periodontitis are common findings in China. Most Chinese have no knowledge of common periodontal prevention and treatment and very few have regular dental care. The data of this study suggest that age, smoking, and limited education are significantly associated with Chinese adult periodontal attachment loss. Preventive periodontal care and education should be reinforced in the future by establishing relevant oral health projects.

[Detection of gingipian gene of Porphyromonas gingivalis in subgingival plaque].

PURPOSE: The purpose of this study was to detect two genes (kgp-cd and rgpB-cd) of Porphyromonas gingivalis in subgingival plaque, and determine the relationship between the two genes and the periodontal clinical indexes. METHODS: Eighty four subgingival plaque samples were included in this study. The extracted DNA was amplified with the primers designed to obtain the genes encoding the catalytic domain of kgp and rgpB (kgp-cd, rgpB-cd), and typing P.gingivalis into two genotypes. The relationship between different genotypes of P. gingivalis and the periodontal clinical indexes was statistically analyzed by SPSS11.5 software package for Student's t test and Chi-square test. RESULTS: The detection rate of type-A P.gingivalis (85.29%) was higher than that of type-B P.gingivalis (14.71%), P<0.05. Both probe depth and bleeding on probing had significant difference between different genotypes of P.gingivalis (PD:t=2.85,P<0.05;BOP:P<0.05). CONCLUSIONS: kgp-cd and rgpB-cd were related to pathogenicity of P.gingivalis.

[Clinical association of gingipain K-caspase like subdomain expression of Porphyromonas gingivalis with puberty gingivitis].

OBJECTIVE: To detect and compare the activity and intensity of gingipain K (Kgp)-caspase like subdomain in culture medium and cell extract of Porphyromonas gingivalis (Pg) isolates in puberty gingivitis and to reveal the possible association of Kgp with puberty gingivitis. METHODS: Thirty-six children of 14 to 17 years old were enrolled in this study. Clinical parameters including gingival index (GI), sulcus bleeding index (SBI) and probing depth (PD) were evaluated. Subgingival plaque samples were collected and Pg isolates were obtained. 16S rRNA PCR was used to confirm Pg clinical isolates. Bacteria were grown in batches of BHI base and harvested at the end of log-phase growth. Culture fractions (culture medium and cell extract) of 10 Pg isolates were performed with SDS-PAGE and Western blot technique using primary antibody against specific Kgp-caspase like subdomain. Activity of Kgp in both samples was detected as well. The data were statistically analyzed using SPSS 11.5 software. The relationship between the Kgp intensity/activity of Kgp and the clinical parameters was statistically analyzed using Spearman correlation coefficient. RESULTS: There was positive correlation between the intensity/activity of Kgp and the clinical parameters (P < 0.05). CONCLUSIONS: The Kgp in clinical isolates of Pg from puberty gingivitis is in complicated forms. Caspase-like molecules with low molecular weight may exist as intracellular functional protein molecules which can affect the interaction between Pg and host. Kgp was contributes in certain degree to the pathogenesis of puberty gingivitis.