Effect of dental plaque control on infection of Helicobacter pylori in gastric mucosa.

BACKGROUND: Data on the role of dental plaque in the transmission of Helicobactor pylori have varied. Furthermore, there has been few reports on the relationship between dental plaque control and H. pylori infection of gastric mucosa. The purpose of this study was to elucidate this potential relationship. METHODS: The 13C urea breath test was conducted on 56 subjects who received dental plaque control and 51 subjects who did not. RESULTS: The prevalence of H. pylori in the gastric mucosa was 19.64% in patients who received dental plaque control, which was significantly lower than in those without dental plaque control (84.31%). CONCLUSION: Long-term professional dental plaque control was associated with less gastric reinfection by H. pylori, suggesting that dental plaque control may help to prevent H. pylori-induced gastric disease or reinfection.

The expression of tumstatin is down-regulated in renal carcinoma.

Tumstatin is the 28 kDa NC1 domain of the alpha3 chain of type IV collagen that inhibits pathological angiogenesis and suppresses endothelial cell proliferation and tumor growth. In the present paper, we expressed and purified recombinant human tumstatin protein and then prepared the anti-tumstatin polyclonal antibody. To investigate the expression of tumstatin in renal carcinoma, tumstatin protein was detected by western blotting using the prepared anti-tumstatin antibody and tumstatin mRNA levels were assayed by RT-PCR. The results showed that the expression of tumstatin gene was down-regulated in renal carcinoma tissues and cells. Our study suggests that as a novel endogenous angiogenesis inhibitor, tumstatin gene expression may be a marker for diagnosis, therapy and prognosis of renal carcinoma.

Adenovirus-mediated expression of spermidine/spermine N1-acetyltransferase gene induces S-phase arrest in human colorectal cancer cells.

Spermidine/spermine N1-acetyltransferase (SSAT) is a key enzyme of polyamine catabolism. In a previous study, we constructed a recombinant adenovirus, Ad-SSAT, which can express human SSAT. In the present study, we investigated the effect of Ad-SSAT on the growth and cell cycle of colorectal cancer cells. We found that Ad-SSAT increased the expression of SSAT and inhibited the growth of HT-29 and Lovo cells. The growth inhibition was caused by cell cycle arrest in the S phase. Furthermore, Ad-SSAT was shown to suppress the expression of cyclin A and nuclear factor E2F-1 in HT-29 and Lovo cells. The inhibitory effect of Ad-SSAT on cyclin A promoter activity was also observed in a reporter gene assay. Our results suggest that the expression of SSAT mediated by Ad-SSAT infection inhibits the growth of colorectal cancer cells and induces cell cycle arrest at the S phase, through a mechanism involving the suppression of cyclin A and E2F-1 expression.

Cerium promotes bone marrow stromal cells migration and osteogenic differentiation via Smad1/5/8 signaling pathway.

Cerium (Ce), one of the lanthanides (Ln), displays a variety of biochemical and physiological effects. However, the potential effect and mechanism of Ce on bone metabolism are not well understood. In this study, we investigated the putative role of Ce in regulating the migration and osteogenic differentiation of bone marrow stromal cells (BMSCs) and the underlying mechanism. The results indicated that Ce promoted BMSCs viability and ALP activity at lower concentrations (0.001 µM), and decreased the viability and ALP activity of BMSCs at higher concentrations (10 µM). Ce could also affect the expression of osteogenic transcription factors (Runx2, Satb2 and OCN) in BMSCs. Our results also showed that Ce promoted migration of BMSCs by increasing SDF-1 mRNA expression. As the Smad-dependent BMP signaling pathway plays an important role in migration and osteogenic differentiation of BMSCs, our results are in agreement with Ce promoting the phosphorylation of Smad1/5/8 and translocating to the nucleus by increase BMP2 expression. The activity of p-Smad1/5/8 increased SDF-1 and Runx2 expression level in BMSCs. In conclusion, our results support the notion that Ce promoted migration and osteogenic differentiation of BMSCs by Smad1/5/8 signaling pathway.

Expression of the chemokine CCL28 in pleomorphic adenoma and adenolymphoma of the human salivary glands.

Recent studies have proposed that the chemokine CCL28 is constitutively expressed by epithelial cells in salivary glands and play an important role in lymphocyte trafficking in oral immunity. To date, there is little information on the expression pattern of CCL28 in salivary gland tumors. The purpose of this study was to determine the expression of CCL28 in pleomorphic adenoma and adenolymphoma and to evaluate its potential function in regulating oral carcinogenesis. Immunohistochemical reactivity revealed CCL28 protein expression in the cytoplasm of acinar epithelial cells, both in tumorous tissues and normal adjacent tissues. The level of CCL28 mRNA was markedly reduced in 70% (28/40) of pleomorphic adenomas, and in 81% (26/32) of adenolymphomas, compared to the normal adjacent tissue. CCL28 protein expression was significantly lower in pleomorphic adenomas (P=0.0027, n=40) and in adenolymphomas (P=0.0003, n=32) compared to their normal adjacent tissues. Additionally, the CCL28 protein levels in saliva in the aforementioned patients were lower than those in healthy volunteers. Our study indicated that the reduced expression of CCL28 could possibly be a strategy by recruiting fewer antitumor immunocompetent cells to salivary glands. The expression and secretion of CCL28 may be associated with the pathogenesis of pleomorphic adenoma and adenolymphoma.

Relationship between dental erosion and respiratory symptoms in patients with gastro-oesophageal reflux disease.

OBJECTIVES: Both dental erosion and respiratory symptoms are extra-oesophageal manifestations of gastro-oesophageal reflux disease (GERD). The aim of this study was to determine whether dental erosion was correlated with respiratory symptoms in GERD patients. METHODS: 88 GERD patients were recruited and assigned to three groups mainly according to the frequency of respiratory symptoms: Group I: never; Group II: occasional (1-2 days a week or less); Group III: frequent (3-5 days a week or more). All patients underwent medical evaluations, including medical history, questionnaire answering and alimentary tract examinations. Dental examinations were carried out on these patients and 36 healthy controls. Dental erosions were measured by modified method of Smith and Knight Tooth Wear Index (TWI). Location and severity of dental erosion were recorded. RESULTS: The prevalence of dental erosion in Group III (64.52%) was higher (p<0.05) than that in Groups I (36.67%) and II (44.44%). GERD patients were presented with dental erosion with TWI scores ranging from 1 to 4. Though proportion of dental erosion with Score 2 (7/20) in Group III was higher than that in Group I (2/11) and Group II (3/12), there was no statistical significance in the proportions of erosion scores among three patient groups. Correlation coefficient between airway symptoms and scores of dental erosion was 0.231 (p<0.05). Palatal erosion of upper incisor was seen in 8 persons (72.7%) in Group I, 9 persons (75%) in Group II and 16 persons (80%) in Group III (p>0.05). Labial erosion of upper incisors was found in 1 person in Groups I and II respectively and 4 persons in Group III. All patients with labial erosion on upper incisors had palatal erosion, except 1 patient in Group III. CONCLUSIONS: In GERD patients, dental erosions are more prevalent in patients with frequent respiratory symptoms than those in patients with occasional and without respiratory symptoms. Palatal erosion of upper incisor is the main manifestation in patients. Acid reflux is the main causative factor of dental erosion in GERD patients with airway symptoms.

Effect of dental plaque control on infection of Helicobacter pylori in gastric mucosa.

BACKGROUND: Data on the role of dental plaque in the transmission of Helicobacter pylori have varied. Furthermore, there has been few reports on the relationship between dental plaque control and H. pylori infection of gastric mucosa. The purpose of this study was to elucidate this potential relationship. METHODS: The (13)C urea breath test was conducted on 56 subjects who received dental plaque control and 51 subjects who did not. RESULTS: The prevalence of H. pylori in the gastric mucosa was 19.64% in patients who received dental plaque control, which was significantly lower than in those without dental plaque control (84.31%). CONCLUSION: Long-term professional dental plaque control was associated with less gastric reinfection by H. pylori, suggesting that dental plaque control may help to prevent H. pylori-induced gastric disease or reinfection.

[Effects on Helicobacter pylori reinfection in gastric mucosa by two oral plaque control methods].

OBJECTIVE: To investigate the reinfection rate of Helicobacter pylori (H. pylori) in gastric mucosa by two measures of oral plaque control on patients, and to demonstrate the necessity and better method of plaque control on those patients. METHODS: 148 patients suffered gastritis or gastroduodenal ulcer were assigned into test group 1 (54 patients), test group 2 (55 patients) and control group (39 patients). 13C-urea breath test proved that there were no H. pylori in their gastric mucosa. Daily plaque control was used in test group 1, oral professorial interventions were added into test group 2, neither daily plaque control nor oral professorial interventions was conducted in control group. All patients were conducted 13C-urea breath test again after half a year to determine the reinfection rate of H. pylori in gastric mucosa. RESULTS: 5 patients were eliminated because of stopping mouthwash in the test group 1, 8 patients failed to control dental plaque in the test group 2. The infection rates of H. pylori in gastric mucosa of test group 1, test group 2 and control group were 67.3%, 19.1%, 82.1%, respectively. The infection rate of H. pylori of test group 2 was lower significantly than that in control group and test group 1 (chi2=33, P<0.05; chi2=31.06, P<0.05). There were no significant difference between test group 1 and control group (chi2=2.43, 0.1

[Comparison of CCL28 in human labial glands and parotids].

OBJECTIVE: To compare the expression of CCL28 in minor and major salivary glands and clarify the role it plays in IgA secreting by minor salivary glands in oral cavity. METHODS: Labial gland and parotid samples were analyzed with real-time fluorescent quantitative PCR assay for CCL28 mRNA. Rank-sum test was used for data analysis using SPSS 10.0 software package. RESULTS: CCL28 mRNA was abundantly expressed in labial glands of healthy adults. Its expression was higher than that in parotids (P<0.01). CONCLUSION: The results of this article suggest that the expression level of CCL28 in labial glands is remarkably higher than that in parotids, which reminds us that the high concentration of IgA in minor salivary glands may be associated with their high expression of CCL28.

[Three-dimensional finite element analyses of bone surface stress of two kinds of conjunction implant].

OBJECTIVE: To establish a three-dimension finite element model of mandible with two kinds of dental implant and to study the stress of implant-bone interface. METHODS: Measuring the data of the components of the dental implant and using spiral CT image reconstruction technique to scan the cross section of the mandible. Three-dimension finite element analysis software Unigraphics and MSC. Marc/Mentat were used to build the conjunction model and bone model of two implant systems. Loading 200 N axially and 100 N 30 degrees obliquely on the models respectively, the stress distribution patterns of the bone interface of two implant systems were analyzed. RESULTS: The stress distribution on the bone interface of two implant systems was similar. The peak stress of oblique loading was higher than that of axial loading. The peak stress district of the bone was concentrated on the stricture of the implant cervix, which was more obviously displayed on the Replace Select implant. The peak stresses on the bone interface of Replace Select implant were higher than that of Replace implant in all loadings. CONCLUSION: To Replace Select especially, oblique force should be avoided in clinical practice in case of the bone absorption.

[Nasal immunization with co-expression plasmid harboring genes encoding porphyromonas gingivalis FimA and human interleukin-15 in mice].

OBJECTIVE: To observe the antibody responses induced by recombinant plasmid plRES-fimA:IL15 via nasal immunization to BABL/c mice and the regulation of IL-15 to sIgA. METHODS: BABL/c mice were immunized with recombinant plasmids pIRES-fimA:IL15 and pIRES-fimA via nasal or intramuscular route. Serum IgG and salivary sIgA levels after immunization were analyzed by ELISA. RESULTS: Nasal immunization with plasmids pIRESfimA:IL15 or pIRES-fimA elicited significant higher level of salivary FimA-specific sIgA responses compared with intramuscular immunization. There was no significant difference of the serum IgG responses between nasal immunization mice and intramuscular immunization mice. Nasal immunization with plasmid pIRES -fimA:IL15 elicited significant higher level of salivary sIgA response than with pIRES-fimA (P<0.05). CONCLUSION: Nasal dropping may be an effective mucosal immunization route of anti-Porphyromonas gingivalis DNA vaccine to elicit specific antibody responses in serum and oral region. IL-15 has a positive regulation effect to sIgA response.

[Construction and verification of the dual-promoter plasmid pCN-SSISG as bivalent anti-caries DNA vaccine].

PURPOSE: The aim of the study is to construct an anti-caries DNA vaccine with high immunogenicity due to its unique properties of being able to express target antigens both in eukaryotic and prokaryotic host cells and harboring two main virulence genes from caries pathogen Streptoccocus mutans (S. mutans). METHODS: The gene encoding glucan binding region (GBR) of glucosyltransferase-I (GTF-I) was amplified from the plasmid harboring the gtfB gene from S. mutans by PCR. Then the GBR gene that was upstream linked with tissue-type plasminogen activator signal peptide (tPA-SP) was directly cloned into the plasmid pCN-SSIE containing sSBR gene encoding tPA-SP and saliva binding region (SBR) of antigen protein I/II (AgI/II) from S. mutans. And finally the recombinant plasmid pCN-SSISG was analysed by DNA sequencing and endonuclearase digestion mapping. RESULTS: DNA sequencing and endonuclearase digestion mapping showed that the open reading frame (ORF) and the tPA-SP sequence of the recombinant plasmid pCN-SSISG were identical with the expectant ones. CONCLUSION: We have successfully constructed the dual-promoter bivalent recombinant plasmid pCN-SSISG.

[Construction of expression vector containing S. mutans GBR gene and confirmation of the immunogenicity of the recombinant GBR protein].

PURPOSE: The purpose of this study is to construct the expressing plasmid vector containing the GBR gene of Streptococcus mutans and study the immunogenicity of recombinant GBR protein. METHODS: The GBR gene was cloned into the expression vector pTriEx-4 through gene cloning techniques by PCR,T-A clone and etc,the recombinant plasmid pTriEx-4-GBR was analyzed by DNA sequencing and endonuclearase digestion mapping. The recombinant GBR(rGBR) protein expression was induced with IPTG in E. coli JM109(DE3) which was transformed with plasmid pTriEx-4-GBR and then the rGBR protein was purified by affinity chromatography. Balb/c mice were randomly divided into two groups:mice of experimental group were inoculated subcutaneously with the rGBR protein and the rGBR protein was replaced for NS in the control group, then the anti-serum was evaluated by ELISA.The data were analysed by statistical software PEMS3.0. RESULTS: The DNA sequence and the reading frame of GBR gene in the reconstructed vector pTriEx-4-GBR was in corresponding with the initial design and the rGBR protein was purified. The level of specific anti-rGBR serum IgG in the experimental group was significantly higher than that in the control group(P<0.005). CONCLUSION: The results showed that the expressing plasmid carrying the GBR gene was constructed successfully and the purified recombinant GBR protein can elicit specific murine system immune response, which is necessary for further experiments including construction of bivalent anti-caries DNA vaccine and studies both in vitro and in vivo.

[Construction of eukaryotic co-expression plasmid harboring genes encoding Porphyromonas gingivalis fim A and human IL-15].

OBJECTIVE: To construct a eukaryotic co-expression plasmid pIRES-fimA:IL15, which can be used as an immunoreaction-enhancing DNA vaccine against Porphyromonas gingivalis FimA, and investigate its expression in mammalian cells. METHODS: The eukaryotic co-expression plasmid pIRES-fimA:IL15 was constructed by molecular cloning methods and characterized by restricted endonuclease mapping, PCR and DNA sequencing. The plasmid was transfected into mammalian cell CHO using Lipofectamine 2000. Expression of fimA gene was detected by Western blot and the protein secretion in cultural medium was analyzed by ELISA. RESULTS: Endonuclease mapping showed that the target genes fimA and IL-15 obtained by PCR had the same molecular size as predicted. The DNA sequencing data also indicated that inserted fimA gene and IL-15 gene had correct DNA sequence and orientation. The recombined plasmid could express FimA in mammalian cell CHO transfected. FimA and IL-15 could be secreted into cultural supernatant detected by ELISA. CONCLUSION: A new eukaryotic co-expression plasmid pIRES-fimA: IL15 was constructed and it could be applied for further immunization in animal as an effective anti-Porphyromonas gingivalis vaccine.

[Construction of a dual-promoter DNA expression plasmid pCN-SSIE harboring gene encoding SBR of Streptococcus mutans and verification of its immunogenicity as DNA vaccine].

PURPOSE: To construct a dual-promoter expression plasmid that harbors the target gene encoding SBR of Streptococcus mutans and can be applied as DNA vaccine especially suitable for using attenuated Salmonella as delivery vector to elicit effective mucosal immune responses because of its advantage of possessing dual-promoter. METHODS: Genes encoding SBR and green fluorescence protein gene (EGFP) were amplified by PCR and inserted to the proper sites of vector pCMVnir. Then IRES sequence was inserted between the genes coding for SBR and EGFP. Furthermore, a DNA fragment encoding tissue-type plasminogen activator (tPA) signal peptide was fused to the 5' end of target gene. Thereby, construction of the dual-promoter expression plasmid pCN-SSIE was completed and then the plasmid was analyzed with DNA sequencing and endonuclearase digestion mapping. The expressions of SBR protein by attenuated Salmonella SL3261 and CHO cell transformed or transfected by the plasmid were tested respectively. Finally, BALB/c mice were immunized through injecting intramuscularly with plasmid pCN-SSIE and anti-SBR specific IgG in serum was tested. RESULTS: Both DNA sequencing and endonuclearase digestion mapping showed that the construction of pCN-SSIE was successful with its open reading frame being correct. The expressions of SBR protein in transformed attenuated Salmonella SL3261 and transfected CHO were detected, and anti-SBR specific IgG levels in serum of immunized mice were markedly higher than the control. CONCLUSION: The construction of the dual-promoter expression plasmid pCN-SSIE was successful and the plasmid can express in prokaryocyte and eukaryocyte and elicit dramatic immune response when applied as DNA vaccine in experimental animal.

[Clinical evaluation on effects of Ca(OH)2-glycerol paste for dental canal sterilization].

OBJECTIVE: Through clinical observation on an formula containing mainly Ca(OH)(2) for dental canal sterilization to confirm it as an ideal canal sterilizer. METHODS: 5% (M/V) of Ca(OH)(2) in glycerol was used as dental canal sterilizer. Patients with acute or chronic apical periodontitis were randomly selected, and their symptoms were recorded before treatment. The dental canals were prepared routinely only with exception of that the sterilizer was 5%(M/V) of Ca(OH)(2) in glycerol and paper point or cotton point soaked with and the canals were sealed for 5 to 7 days. Then the canals were filled if there was no positive symptom or re-sterilized, if symptom did not totally disappear. RESULTS: Through sterilization with the formula used in this study, the symptom disappeared swiftly. Specifically, after the canals sterilized for one to two times, there was no symptom that could be seen in all patients studied. The rate of symptom disappeared from 89% to 98% could be detected in acute apical periodontitis and the rate of no symptom was from 94% to 99% in chronic periodontitis. Additionally, through the study for more than one year, the formula maintained thin paste state that was convenient for use. CONCLUSION: In addition to safety, using the formula with Ca(OH)(2) as main sterilizer is effective in dental canal sterilization for the formula dramatically improving the symptom.

[The clinical study on the adjunctive effects of aqueous extract from coptis root for the treatment of chronic periodontitis].

PURPOSE: To make a therapeutic membrane with aqueous extract from coptis root and explore its adjunctive effects for treating chronic periodontitis. METHODS: Drug membrane from coptis root aqueous extract was developed; 4 teeth in 30 patients with moderate to advanced periodontitis were randomly divided into four groups: coptis root membrane, iodine glycerin, single drug membrane and blank control group. All parameters including plaque index (PI), probing depth (PD), attachment loss (AL) and bleeding on probing (BOP) were measured at baseline, 4 and 7 weeks after treatment. Analysis of variance and chi-square test were carried out for analysis. RESULTS: In all four groups, there were significant differences of PD, AL, BOP between baseline and 4,7 weeks after treatment (P<0.05), the treatment effect of coptis root membrane was significantly superior to that of other three groups (P<0.05). Moreover, all the parameters improved continuously. CONCLUSION: Use of coptis root membrane as an adjunctive method after scaling can significantly improve the treatment effect of periodontitis.