A new guaiane-type sesquiterpenoid from Croton yunnanensis / 中国中药杂志

Five sesquiterpenoids were isolated from 90% ethanol extract of Croton yunnanensis by silica gel,Sephadex LH-20 column chromatography,as well as prep-HPLC methods. Based on MS,1 D and 2 D NMR spectral analyses,the structures of the five compounds were identified as 11-methoxyl alismol(1),6β,7β-epoxy-4α-hydroxyguaian-10-ene(orientalol C,2),multisalactone D(3),arvestonol(4),and 4,5-dihydroblumenol A(5). Compound 1 was a new guaiane-type sesquiterpenoid. Compounds 2-4 were isolated from the Croton genus for the first time,and compound 5 was obtained from this plant for the first time.

Triterpenoid saponins from the roots of Cyathula officinalis and their inhibitory effects on nitric oxide production / 中国天然药物

The present study was designed to investigate the chemical constituents of the roots of Cyathula officinalis. Compounds were isolated by silica gel, Sephadex LH-20, ODS column chromatography, and preparative HPLC. Their structures were determined on the basis of 1D and 2D NMR techniques, mass spectrometry, and chemical methods. One new oleanane-type triterpenoid saponin, 28-O-[α-L-rhamnopyranosyl-(1→3)-β-D-glucuronopyranosyl-(1→3)-β-D-glucopyranosyl] hederagenin (1), was isolated from the roots of Cyathula officinalis. The anti-inflammatory activities of the isolates were evaluated for their inhibitory effects against LPS-induced nitric oxide (NO) production in RAW 264.7 macrophages cells. Compounds 2, 4, and 6 exhibited moderate anti-inflammatory activities.

Characterization of oral bacterial diversity of irradiated patients by high-throughput sequencing / 国际口腔科学杂志·英文版

The objective of this study was to investigate the compositional profiles and microbial shifts of oral microbiota during head-and-neck radiotherapy. Bioinformatic analysis based on 16S rRNA gene pyrosequencing was performed to assess the diversity and variation of oral microbiota of irradiated patients. Eight patients with head and neck cancers were involved in this study. For each patient, supragingival plaque samples were collected at seven time points before and during radiotherapy. A total of 147,232 qualified sequences were obtained through pyrosequencing and bioinformatic analysis, representing 3,460 species level operational taxonomic units (OTUs) and 140 genus level taxa. Temporal variations were observed across different time points and supported by cluster analysis based on weighted UniFrac metrics. Moreover, the low evenness of oral microbial communities in relative abundance was revealed by Lorenz curves. This study contributed to a better understanding of the detailed characterization of oral bacterial diversity of irradiated patients.

Analysis of community composition in dental plaque of elder people with root caries / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To analyze the community in dental plaque of elder people with root caries.</p><p><b>METHODS</b>Total DNAs were extracted from the root caries dental plaques of nine elders over 60 years of age. Polymerase chaid reaction-based denaturing gradient gel electrophoresis (PCR-DGGE) was used to analyze the microbial composition, DGGE bands were excised from the gels for sequencing and identification.</p><p><b>RESULTS</b>The dominant genus in root caries dental plaque of elder people were: Acinetobacte [0.9% (1/114)], Actinobaculum [1.8% (2/114)], Actinomyces [15.8% (18/114)], Aggregatibacter [0.9% (1/114)], Capnocytophaga [14.0% (16/114)], Corynebacterium [0.9% (1/114)], Haemophilus [0.9% (1/114)], Mobiluncus [0.9% (1/114)], Naxibacter [0.9% (1/114)], Neisseriaceae [10.5% (12/114)], Porphyromonas [0.9% (1/114)], Prevotella [12.3% (14/114)], Selenomonas [6.1% (7/114)], Staphylococcus [1.8% (2/114)], Oralis streptococcus [6.1% (7/114)], Mutans streptococcu [7.9% (9/114)], Tannerella [0.9% (1/114)], Treponema [1.8% (2/114)], Veillonella [10.5% (12/114)] and two uncultured unknown genus [1.8% (2/114)]. Uncultred genotypes accounted for 19.30% of the total. Gram-positive bacteria genotype accounted for 31.6% (36/114), and Gram-negative bacteria genotype accounted for 66.7% (76/114).</p><p><b>CONCLUSIONS</b>There were many bacteria genotypes in root caries dental plaque in the elderly, which were widely distributed. Gram-negative bacteria accounted for the majority. Genotype-specific pathogenic bacteria were not found.</p>

Modeling of diffusion transport through oral biofilms with the inverse problem method / 国际口腔科学杂志·英文版

<p><b>AIM</b>The purpose of this study was to develop a mathematical model to quantitatively describe the passive transport of macromolecules within dental biofilms.</p><p><b>METHODOLOGY</b>Fluorescently labeled dextrans with different molecular mass (3 kD, 10 kD, 40 kD, 70 kD, 2000 kD) were used as a series of diffusion probes. Streptococcus mutans, Streptococcus sanguinis, Actinomyces naeslundii and Fusobacterium nucleatum were used as inocula for biofilm formation. The diffusion processes of different probes through the in vitro biofilm were recorded with a confocal laser microscope.</p><p><b>RESULTS</b>Mathematical function of biofilm penetration was constructed on the basis of the inverse problem method. Based on this function, not only the relationship between average concentration of steady-state and molecule weights can be analyzed, but also that between penetrative time and molecule weights.</p><p><b>CONCLUSION</b>This can be used to predict the effective concentration and the penetrative time of anti-biofilm medicines that can diffuse through oral biofilm. Furthermore, an improved model for large molecule is proposed by considering the exchange time at the upper boundary of the dental biofilm.</p>

Identification and quantitative analysis of Archaea involved in periodontal disease / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To make qualitative and quantitative analysis of Archaea in subgingival plaque sample and to investigate the relationship between periodontal disease and Archaea.</p><p><b>METHODS</b>Subgingival plaque was collected from 23 patients with aggressive periodontitis, 29 with chronic periodontitis, 35 with plaque-induced gingivitis and 38 healthy controls. Qualitative and quantitative analysis of methanogenic archaea was performed by amplification of the 16S rRNA genes in the DNA extracted from the plaque samples.</p><p><b>RESULTS</b>Archaea were found in 65% of aggressive periodontitis patients, 72% of chronic periodontitis, 26% of gingivitis and zero of healthy subjects. Quantitative analysis showed the average abundance of archaeal 16S rRNA gene in Archaea-positive patients was different among the three groups. The average 16S rRNA gene copy number from per microg wet plaque was 6.66 x 10(6) in aggressive periodontitis sufferers, 4.47 x 10(6) in chronic periodontitis and 1.78 x 10(6) in gingivitis groups. The prevalence of Archaea and the average Archaea 16S rRNA gene numbers in periodontitis groups were higher than those in gingivitis group (P < 0.05).</p><p><b>CONCLUSIONS</b>This suggests that Archaea may be implicated as causative agents for periodontitis.</p>

Comparative study on different methods for quantitative analysis of oral common microorganisms / 上海第二医科大学学报

flow cytometry.A strong linear relationship was observed in the standard curve of real-time PCR of each bacteria. Conclusion These three non-culture methods can be used in the quantitative analysis of oral microorganisms.Real-time PCR and laser scanning confocal microscopy are better than the traditional culture-based CFU count,and real-time PCR is the most sensitive method.

Differential gene expression between Streptococcus sobrinus 6715 and its fluoride-resistant strains / 上海第二医科大学学报

Objective To detect the differential gene expression between Streptococcus sobrinus(S.sobrinus) 6715 and its fluoride-resistant strains. Methods The fluoride-resistant strains of S.sobrinus 6715 was induced by increasing the concentration of fluoride step by step.Total RNA of both S.sobrinus 6715 and its fluoride-resistant strains was extracted,mRNA was separated and purificated,and then cDNA was obtained by reversed transcription.Suppression subtractive hybridization(SSH) technology was used to detect the differential gene expression between them.The differential gene expression fragments were cloned and compared with the GenBank by BLAST.Results After comparing with the GenBank by BLAST,it was identified that there were two differential gene expression fragments,fruA and SMU.438c. Conclusion The cDNA subtractive lib of differential gene expression between S.sobrinus 6715 and its fluoride-resistant strains was successfully constructed through SSH,which paves a way for the further study of fluoride-resistant mechanism.

Quantitative analysis of cariogenic strains in dental plaque of caries-susceptibile children by real-time PCR / 上海第二医科大学学报

8).The amount of the targeted microorganisms(Streptococcus mutans,Streptococcus sobrinus,Actinomyces viscosus and Actinomyces naeslundii) and the total number of bacterial cells were determined by real-time PCR based on SYBR-Green I fluorescence.Results The percentages of the four targeted bacteria in high-caries group were significantly higher than those in caries-free group(P