Objective:To obtain crude mutacin produced by clinical isolate of Mutans streptococci (Ms) and to test its antibacteria activity. Methods:The mutacin in supernatant of in vitro cultured clinical isolate of Ms was extracted by chloroform, the antibacteria activity and heat stability of the crude extract were tested by bacteria culture technique. Results:Crude extract of protein was obtained fom clinical isolate of Ms. 10 ml of the liquid extract produced a 19 mm inhibitory zone in cultrue dish, indicating its antibacteria activity. The activity could maintain in 80 ℃ for 120 min, indicating its heat stability. Conclusion: The crude extract can represent the antibacteria activity and heat stability of mutacin.

Objective: To sequence V-region and P-region gene of surface protein of serotype c Streptococcus mutans clinical isolates with different adherent abilities. Methods: The clinical isolates of serotype c S.mutans included two groups with different spaP-pv AluI genotypes, which were derived from previous studies in our lab. The genome DNA was extracted. The spaP-pv (2 060-3 157 bp) was amplified by PCR, then sequenced and analyzed. Results: Seven sites of AluI 5′-AG↓CT- 3′were included in the sequences of spaP-pv of both genotypes strains. The sequences of spaP-pv of ten a-genotype strains were the same except several site mutations, and so were those of b-genotype strains. Two different DNA fragments were revealed between a and b geotype strains. And they were located in the V-region of spaP. Conclusion: The mutation of gene encoding V-region of S.mutans clinical isolates might be related to the differences of adherent abilities .

Objective:To evaluate the human pulp response following direct pulp capping with Clearfil SE BOND (SB). Methods:45 sound human third molars in 24 volunteers were used. Pulp of 41 molars was mechanically exposed and then the teeth were divided into two groups: in group A the pulp was capped with SB, in group B the pulp was capped with calcium hydroxide (CH), another 4 teeth were served as the control. After 7, 30 and 90 days, the teeth were extracted and processed for light microscopic examination. Results:7-30 days after capping slight inflammatory reaction was observed in group A and group B. The reaction in group A was sligter than that in group B(P

Objective:To investigate the relationship between Mutans streptococci (MS) transmission from mothers to children and its initial adherence properties.Methods:200 MS isolates were genotypied by AP-PCR to demonstrate transmission between 20 pairs of mother and child aged 3~4 years, and to detect the transmitted strains and non-transmitted strains of mothers. Then the adherence of the strains to salivary coated hydroxyapatite beads (SHA) were determined by 3H- thymidine incorperation assay.A restriction fragment length polymorphism (RFLP) study of the different regions(spap-a,spap-pv)of the spap were undertaken by endonuclease haeⅢ and AluⅠrespectively. Results:The transmitted strains showed weaker adherence properties than the non-transmitted strains (P

Objective:To investigate the gene expression variety of different genotype of F-ATPase subunit uncEBF in Streptococcus mutans (S.mutans) and to evaluate the relationship among uncEBF gene expression levels, genotypes and the acidurance ability of S.mutans. Methods:The relative expression quantity of uncEBF gene against the housekeeping gene recA was determined by the two-step method of semi-quantitative RT-PCR in 18 clinical isolates of S.mutans(7 with genotype A uncEBF and 11 with genotyp B,10 with high acidurance and 8 with low). A gel documentation system and QUANTITY ONES software were used to assay the data. Results:uncEBF mRNA expression level in the isolates with genotype A uncEBF was higher than that in those with genotype B(P

0.05);by the end of the experiment that was 24.5?1.05,28. 3?1.29,26.6?1.19,10.2?1.81, 26.3?1.54 and 27.3?1.38 respectively (D vs each of the other groups P0.05). Conclusion: Gene vaccines pcDNA3-pac and pcDNA3-gtfB have no unfavo rable influence on weight of gnotobiotic rats,while the inactive whole cell vac cine has.

Objective:To investigate whether the AP-PCR fingerprint of mutans streptococci(MS) can be displayed by PAGE-AgNO 3 staining. Methods: Amplification products of 200 MS clinical isolates by AP-PCR was separated and stained by ?=3.5%PAGE-AgNO 3 and agarose-EB respectively. Results were compared and the agreement value of Kappa between two methods was calculated. Results: ?=3.5%PAGE-AgNO 3 discerned both homogeneity and heterogeneity of MS genotypes, just as agarose-EB,Kappa value for agreement was 1.00 . Moreover, more bands was showed by PAGE-AgNO 3 staining than by agarose-EB, so PAGE-AgNO 3 gave a clearer pattern than agarose-EB. Conclusion: AP-PCR fingerprint of MS can be displayed by ?=3.5%PAGE-AgNO 3 staining.

OBJECTIVEGlucosyltransferase-B (GTF-B) of Streptococcus mutans has been implicated as a principal virulent factor in the development of dental caries. The objective was to use recombined plasmid pcDNA-gtfB expressing multiple antigen of glucosyltransferase-B as gene vaccine to immunize rats through different route, and to investigate the immunization effects of immunization routes.

METHODSA total of 18 Wistar rats were divided into 3 groups, including the quadriceps injection group, the intransal irrigation group and the submandibular gland-targeted injection group. The serum IgG and salivary IgA were assayed by using ELISA after pcDNA3-gtfB immunization. The serum IgG and salivary IgA in different groups were compared using statistical one-way ANOVA.

RESULTSCompared these 3 groups, the serum IgG in the quadriceps injection group was much higher than those of other two groups (P < 0.01), while the salivary IgA of the submandibular gland-targeted injection was much higher than those of other two groups (P < 0.01).

CONCLUSIONIt is indicated pcDNA3-gtfB is good candidate for anticarious gene vaccine, and submandibular gland-targeted injection is an effective immunization route for stimulating salivary IgA.

Animals ; Antibodies, Bacterial ; biosynthesis ; Bacterial Vaccines ; administration & dosage ; immunology ; Cloning, Molecular ; Dental Caries ; prevention & control ; Glucosyltransferases ; genetics ; immunology ; Immunization ; Immunoglobulin A, Secretory ; analysis ; Immunoglobulin G ; blood ; Male ; Plasmids ; genetics ; immunology ; Random Allocation ; Rats ; Rats, Wistar ; Recombination, Genetic ; Saliva ; immunology ; Streptococcus mutans ; genetics ; immunology ; Vaccines, DNA ; administration & dosage ; immunology

OBJECTIVEThis study aimed at investigating the transcription and expression of recombined plasmid pcDNA3-gtfB which encoding multiple glucosyltransferase-B antigenic gene, and the feasibility of the pcDNA3-gtfB used as gene vaccine.

METHODSThe pcDNA3-gtfB was transfected into mammalian cell COS-1 with liposome. The total RNA of COS-1 cell transfected by pcDNA3-gtfB was extracted and purified. Using the total RNA as template, the transcription of pcDNA3-gtfB was assayed by reverse transcription polymerase chain reaction (RT-PCR). The expression product of pcDNA3-gtfB was identified with 5% SDS-PAGE, and then assayed using Western-blotting. The expression product of pcDNA3-gtfB was also assayed by using LSAB method, and cell transfected by pcDNA3 as the negative control.

RESULTSIdentified by agarose gel electrophoresis, the target gene fragment had the same molecular size (3.6 kb) as it was predicted, and it indicated that pcDNA-3gtfB was correctly transcribed into mammalian cells. Proved by SDS-PAGE, the molecular weight of the expression product (116-212 kD) was also the same as it was supposed to be. It was also indicated by Western-blotting and LSAB assay that the expression product induced immunizing response.

CONCLUSIONAs gene vaccine, it is importance that the recombined plasmid could be correctly transcribed and expressed in mammalian cells. It was suggested by RT-PCR, LSAB and Western-blotting that recombined plasmid pcDNA3-gtfB could be correctly transcribed and expressed in mammalian cells, and the expression product could induce immunizing response, which support its use as gene vaccine candidates in the development of anticaries vaccines.

Animals ; COS Cells ; Cercopithecus aethiops ; Cloning, Molecular ; Dental Caries ; prevention & control ; Eukaryotic Cells ; metabolism ; Genetic Vectors ; Glucosyltransferases ; genetics ; Plasmids ; genetics ; immunology ; Rabbits ; Recombination, Genetic ; Streptococcus mutans ; genetics ; Transcription, Genetic ; Vaccines, DNA

Objective:The paper is designed to reveal differences in stroke patients'hospitalization costs crea-ted by different socioeconomic factors , health insurance and occupational background , and analyze those differences on health outcome .Methods:18879 cases of hospitalized patients with stroke in five tertiary hospitals from four prov-inces from 2011 to 2014 were included in the database .Descriptive statistics was used to describe patients'hospitali-zation costs and health outcome .Multiple linear regression model and logistic regression were used to evaluate the im-pact of insurance and occupation .Results:After controlling for patients'social characteristics , health risks , premise during hospitalization process and clinical characteristics of patients with free healthcare costs , the socialized medi-cine was charged 19.7% higher than the private ones ( P <0.001 ), the retired people and civil servants were charged 4.2%(P<0.001) and 2.9%(P=0.049) more than farmers.The socialized medicine was also associated with health outcome.The risk of death in patients with free medical care is (OR=4.901) compared with private pa-tients (95%CI 1.652~14.537), and the retired people had increased risk of death compared with farmers (OR=2 .145 , 95%CI 1 .287 ~3 .573 ) .Conclusions: Due to the impact of social background factors , some groups are found to have a higher level of expenses than their counterparts during hospitalization , but the more hospitalization costs are not spent the better the health outcome of stroke was achieved .