Overview of technical advances in the diagnosis of pulp and periapical diseases / 中华口腔医学杂志

Pulp and periapical diseases are common and frequently occurring diseases of which diagnosis and treatment must be dealt with by the dental clinicians. The diagnostic techniques of these diseases include evaluation of pulp vitality, measurement of pulp blood circulation and analysis and judgment of root canal anatomy. With the continuous emergence of digital and imaging technologies, the correct application of these technologies in clinic will help clinicians improve their abilities in diagnosis and treatment of related diseases. The present article summarizes and reviews the progress of assistant technology for diagnosing dental pulp and periapical diseases in recent years and puts forward some suggestions for its application.

Research Advance of CXCR4 Inhibitors in the Treatment of Acute Myeloid Leukemia--Review / 中国实验血液学杂志

CXCL12/CXCR4 axis composed of chemokine CXCL12 and its specific ligand CXCR4 can regulate and control the adhesion of leukemia cells to protective bone marrow niche, promote cell survival, and resist apoptosis induced by signal transduction inhibitors and chemotherapeutic drugs. Therefore, CXCL12 /CXCR4 axis has become a new target for the treatment of acute myeloid leukemia. At present, CXCR4 inhibitors that have been developed are in different clinical trials, showing good anti-leukemia effect. In this review, the research advance of CXCR4 inhibitors in the treatment of acute myeloid leukemia is summarized briefly.

Effect of different stress conditions on growth and biofilm formation capability of Enterococcus faecalis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study the changes of growth and biofilm formation capability of Enterococcus faecalis (Ef) in different stress conditions.</p><p><b>METHODS</b>The changes of growth of Ef in stress conditions were observed by measuring the A600 value with ultraviolet spectrophotometer. Ef was incubated on glass slide in stress conditions, biofilm formation capability of cells was investigated by colony-forming unit (CFU) counting of the culturable bacteria and fluorescence confocal laser scanning microscopy.</p><p><b>RESULTS</b>Ef couldn't growth under the conditions of 2%, 5%NaClO, pH = 11 and 12, the A600 value was unchanged in 96 hours. But the growth curve changed at different levels in other stress conditions: under 1%NaClO, the A600 value peaked at 1.461 at 16 hour (the peaked level was 1.238 at 6 hours in control group) ; under 0,0.05%,0.15% glucose, it peaked at 0.645,0.890, 1.173, respectively, at 6 hour (it was maximized to 1.195 at 6 hours in control group); the A600 value peaked at 1.704 at 6 hours at pH = 9 and 1.225 at 10 hours at pH = 10 (the peak level was 1.732 at 6 hours at pH = 7) . Biofilm assay showed that Ef were able to form biofilm in these stress conditions except 5%NaClO and pH = 12.</p><p><b>CONCLUSIONS</b>Ef could growth and form biofilms in energy starvation, low concentrations of sodium hypochlorite and weak alkaline stress.</p>

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>

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