BACKGROUND: Streptococcus mutans (S. mutans) is generally considered to be the principal aetiological agent for dental caries, thrS gene may relate to the virulence of S. mutans involved in the adherence, acidogenicity and acidodurance.OBJECTIVE: To investigate the conservation status of the thrS gene of S. mutans and to construct the homologous recombinant plasmid.METHODS: Southern Blot was used to analyze the distdbuUon of thrS gene in S. mutans. The upstream and downstream sequences of thrS gene were cloned respectively into multiple cloning sites of suicide plasmid pFW5 to construct the recombinant plasmid,RESULTS AND CONCLUSION: The thrS gene was conserved in 6 strains of S. mutans in this test. By PCR analysis and enzyme digesting, it was confirmed that S. mutans thrS gene homologous recombinant plasmid was successfully constructed,which can be used in future research of construction of thrS -negative mutans of S. mutans strain UA159.

Objective:To knock the phospho-sugar mutase gene (psm) out of the genome of S. mutans strain UA159 and to construct the mutant will lay a foundation for the study of the function of the psm. Methods:Two upstream and downstream DNA sequences of the psm were selected and cloned respectively into multiple cloning sites I and II of suicide plasmid pFW5 to construct the recombinant plasmid which was confirmed by enzyme digesting and sequencing. The recombinant plasmid was transformed into S. mutans UA159 by natural transformation and antibiotic was used to screen the positive transformants. According to the principle of homologous recombination, allelic exchange between the recombinant plasmid and S. mutans UA159 was achieved. Results:By PCR analysis and sequencing, it was confirmed that the psm of S. mutans UA159 was substituted for resistant gene of spectinomycin. Conclusion: The psm-negative mutants of S. mutans UA159 is successfully constructed.

Objective To compare the effects of Dan Shen Extract F(DSEF) and cimetidine (CI) on reperfusion injury in gastric antrum. Methods Nineteen Wistar rats were randomly allocated to receiving intravenously normal saline (group NS, n = 7), DSEF 1g/100g wt (group DSEF, n = 6) or CI 6.5mg/ 100g wt (group CI, n = 6 ) respectively. Model of hemorrhagic shock roperfusion injury was produced by Itch method. The index and depth of gastric mucosal lesion, prostaglandins content and intracellular calcium content of gastric antrum mucosa were measured. Results (1 ) As compared with those in group NS, the index and depth of gastric mucosal lesion (grade 2, 3) decreased significantly in group DSEF and CI (P 0.05 ). (3 ) The intracellular calcium content in group DSEF and CI was markedly lower than that in group NS (P 0. 05). Conclusions Both DSEF and CI can prevent largely the reperfusion injury in gastric antrum mucosa through different mechanisms, with DSEF having stronger potency.

Objective To investigate the correlation between non-lacunar infarcts in the white matter of brain and intracranial or extracranial vessels stenosis.Methods Brain magnetic resonance imaging(MRI) and digital subtraction angiography(DSA) were performed in 30 patients with non-lacunar infarcts in the white matter of brain and the results were analyzed.Results Of 12 cases with focal non-lacunar infarcts in the area of basal ganglion,9 cases were shown occlusion or highly stenosis of proximal segments of unilateral internal carotid artery(ICA) in DSA,2 cases were shown highly stenosis of M1 segment of middle cerebral artery(MCA),and 1 case was normal.Of 6 cases with focal non-lacunar infarcts in the area of basal ganglion and lateral periventricular white matter,3 cases were shown occlusion or highly stenosis of proximal segments of unilateral ICA in DSA,1 case was shown occlusion of C5 segment of unilateral ICA,and 2 cases were shown occlusion of M1 segments of MCA.Of 4 cases with focal non-lacunar infarcts in periventricular white matter or centrum ovale,1 case was shown occlusion of C5 segment of unilateral ICA,2 cases were shown highly stenosis of M1 segments of MCA,and the other one was normal.Of 8 cases with subcortical superior border infarction(SSBI) or subcortical lateral border infarction(SLBI),6 cases were shown occlusion or highly stenosis of proximal segments of unilateral ICA,1 case was shown occlusion of proximal segments of bilateral ICA,and 1 case was shown occlusion of M1 segment of MCA.Conclusion There are strong correlations between focal non-lacunar infarcts in the areas of basal ganglion or lateral periventricular white matter and the stenosis or occlusion of large arteries of ICA system.

Objective To observe the therapeutic effect of resveratrol (Rsv) on psoriasis like skin damage induced by imiquimod (IMQ) and study its mechanism.Methods BALB/c mice were randomly divided into four groups:control group,Rsv group,model (IMQ) group and Rsv treatment (IMQ + Rsv) group with six mice in each group.Psoriasis like skin model induced by smearing IMQ in the mice's ear for 8 d,20 mg Rsv cream were gave at the same time for treatment.Observe erythema and psoriasis degree,and measure ear thickness with vemier caliper.HE staining was used to observe tissue change,real time quantitative PCR (qRT-PCR) was used to detect K17,IL-17A,IL-19 and IL-23 mRNA and Western blotting were used to detected K17 protein expression in tissues.Results Compared with the model group,mice erythema area and the thickness of epidermal scale decreased significantly in Rsv treatment group;HE staining results showed that,Rsv significantly reduced ear marginal tissue epidermal thickness,and diminished severity of the psoriasis-like skin inflammation.qRT-PCR and Western blotting confirmed a Rsv dependent decrease of in K17,IL-17A and IL-19 in mRNA level and protein levels of K17.Conclusion Rsv improves psoriasis like skin damage by down-regulating expression of Keratinl 7.

Objective:To explore the relationship among childhood psychological maltreatment,online aggressivebehavior and trait anger in college students.Methods:Totally 442 college students (226males,216 females,aged 16-25 years) were surveyed with the Psychological Maltreatment Scale (PMS),Adolescent Online Aggressive Behavior Scale (AOABS) and Trait Anger Scale (TAS).The bias-corrected percentile bootstrap method was used to analyze the mediating effect of trait anger between childhood psychological maltreatment and online aggressive behavior.Results:The scores of PMS,AOABS and TAS were positively correlated each other(r =0.44,0.37,0.48,Ps ＜0.01).The PMS scores had a significantly direct effect on the AOABS scores,its estimate was 0.27.The PMS scoreshad a significantly indirect effect on the AOABS scores through TAS scores(95％ CI:0.15-0.34).Conclusion:It suggests that the trait anger may be related to childhood psychological maltreatment and online aggressive behavior,and trait anger may play a partial mediating role between childhood psychological maltreatment and online aggressive behaviorin college students.

Objective To study the influence of the preparation and quality control of Xiaochuan cataplasm on its drug action. Methods Xiaochuan cataplasm was prepared with hydrosoluble polymers matrix. A sequence of tests such as adhesive force test, recontour test, paste-content test, cold-resistance test, heat-resistance test, toxicity and pharmacodynamic action tests were performed on this drug. Results Xiaochuan cataplasm contains a sound volume of medicine, and shows good adhesive property, no sensibilization and stimulation, and notable drug action. Conclusion The results demonstrate that the preparation craft of Xiao-chuan cataplasm is reasonable and practicable., the quality is controllable and the method is a safe and effective transdermal drug delivery system.

Objective To study AngⅡ induced apoptosis of HUVECs and to observe the protective effect of serum contained huangqi on endothelial cell.Methods ECV-304 cells were randomly divided into control group,AngⅡgroup and huangqi group.In the control group,cells were cultured for 18 h,and the concentration of AngⅡ were 0 mol/L,1×10-6 mol/L,1×10-5 mol/L and 1×10-4 mol/L.The cell proliferation was measured by MTT assay.Electron microscope was used to observe the change of HU-VECs.Ultrastructure of HUVECs induced by AngⅡ was observed by electron microscope.In the huangqi group,serum contained huangqi of different concentration were added into the medium and cultured for 24 h,then AngⅡ of 1×10-4 mol/L was included and cultured for 18 h,and the apoptosis ratio induced by AngⅡwas measured by flow cytometry.Results AngⅡof different con-centration could all significantly inhibit HUVECs proliferation.AngⅡof different concentration could all induce endothelial cell ap-optosis.HUVECs apoptosis was observed by electron microscope.HUVECs apoptosis induced by AngⅡcould be inhibited by ser-um contained huangqi.Conclusion Serum contained huangqi could protect endothelial cells.

To investigate roles of nitric oxide (NO) signal in accumulations of phenolic acids in abscisic.acid (ABA)-induced Salvia miltiorrhiza hairy roots, S. miltiorrhiza hairy roots were treated with different concentrations of sodium nitroprusside (SNP)-an exogenous NO donor, for 6 days, and contents of phenolic acids in the hairy roots are determined. Then with treatment of ABA and NO scavenger (2-(4-carboxy-2-phenyl)-4,4,5,5-tetramethylimidazoline-1- oxyl-3-oxide, c-PTIO) or NO synthase inhibitor (NG-nitro-L-arginine methyl ester, L-NAME), contents of phenolic acids and expression levels of three key genes involved in phenolic acids biosynthesis were detected. Phenolic acids production in S. miltiorrhiza hairy roots was most significantly improved by 100 µmoL/L SNP. Contents of RA and salvianolic acid B increased by 3 and 4 folds. ABA significantly improved transcript levels of PAL (phenylalanine ammonia lyase), TAT (tyrosine aminotransferase) and RAS (rosmarinic acid synthase), and increased phenolic acids accumulations. However, with treatments of ABA+c-PTIO or ABA+L-NAME, accumulations of phenolic acids and expression levels of the three key genes were significantly inhibited. Both NO and ABA can increase accumulations of phenolic acids in S. miltiorrhiza hairy roots. NO signal probably mediates the ABA-induced phenolic acids production.
Abscisic Acid ; pharmacology ; Benzofurans ; metabolism ; Free Radical Scavengers ; pharmacology ; Hydroxybenzoates ; metabolism ; Nitric Oxide ; metabolism ; Phenylalanine Ammonia-Lyase ; metabolism ; Plant Roots ; metabolism ; Salvia miltiorrhiza ; metabolism ; Tyrosine Transaminase ; metabolism

Objective To investigate the prevalence and charateristics of carotid atherosclerosis among healthy middle-aged people of community. Methods Totally 1930 subjects aged 50 years and above were selected randomly from 10027 participants recruited during Phase 3 of the Guangzhou Biobank Cohort Study (GBCS).Common carotid artery intima-media thickness (CCA-IMT) and carotid plaques (CP) were measured by B-mode ultrasonography using ALT HDI 3000 mainframe with a high-resolution. Results The prevalences of CCA-IMT and CP in men were higher than women [41.5％(400/963)vs.16.2 (157/967),34.1％ (328/967) vs.13.8％ (133/967),both P＜0.001].The prevalence of CCA-1MT was higher with age increasing in either men or women in groups of 50-yrs,60-yrs and 70-79 yrs (all P＜0.001).The most of CP was cankerous spot (37.8％),secondly hard spot (24.9％),soft spot (22.1％) and the prevalence of flat spot was lowest (15.2％).The number of CP was not significantly different between the left and right side (51.0％ and 49.0％).The most common location of CP was bifurcations of carotid arteries (61.7 ％),next the common carotid artery (21.0％) and internal carotid artery (ICA) was lowest (17.3 ％).The prevalence of CP was 44.4％ (83/87) in women aged 50- yrs,it was higher than that in men 20.9％ (108/517).However,the prevalence of CP was 79.1％ (409/517) in men aged more than 60 yrs,higher than that in women (55.6％). Conclusions The carotid atherosclerosis is commonly encountered disease in the male elderly,and the most of CP was cankerous spot in bifurcations of carotid arteries