Link between sortase A function and cariogenicity of Streptococcus mutans: a preliminary metabolomics analysis / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study intends to explore the mechanism underlying the support of sortase A (SrtA) of the cariogenicity of Streptococcus mutans (S. mutans).</p><p><b>METHODS</b>We performed a metabonomics study based on ¹H nuclear magnetic resonance spectroscopy (NMR), in which we compared the extracellular metabolites of wild-type S. mutans UA159 with those of its SrtA-deficient strain. Metabolite differences among strains were identified using a combination of principal component analysis and orthogonality partial least square discriminant analysis.</p><p><b>RESULTS</b>Several differences corresponding mostly to unknown metabolites were identified. Some amino acids such as leucine and valine (δ 0.92×10⁻⁶-1.20×10⁻⁶), lactic acid ( δ1.28×10⁻⁶), oxoglutaric acid (δ 3.00×10⁻⁶), and glycine (δ 3.60×10⁻⁶) differed among strains.</p><p><b>CONCLUSIONS</b>This work establishes the feasibility of using ¹H NMR-based metabonomics to provide leads for research into molecular factors that promote caries. The database of microbial metabolites should be also improved in further studies.</p>

The effect of cold-light-activated bleaching treatment on enamel surfaces in vitro / 国际口腔科学杂志·英文版

This in vitro study aims to evaluate the crystal and surface microstructure of dental enamel after cold-light bleaching treatment. Twelve sound human premolars were cross-split into four specimens, namely, mesio-buccal (Group LP), disto-buccal (Group P), mesio-lingual (Group NP) and disto-lingual (Group L) specimens. These four groups were treated using the standard cold-light bleaching procedure, a bleaching agent, a peroxide-free bleaching agent and cold-light, respectively. Before and after treatment, all specimens were analyzed by high-resolution, micro-area X-ray diffraction and scanning electron microscopy. Using a spectrometer, tooth color of all specimens was measured before and after treatment. The phase of the enamel crystals was identified as hydroxyapatite and carbonated hydroxyapatite. After treatment, specimens in Groups LP and P showed significantly weaker X-ray diffraction peaks, significant reduction in crystal size and crystallinity, significant increase in L* but decrease in a* and b*, and obvious alterations in the surface morphology. However, specimens in Groups NP and L did not show any significant changes. The cold-light bleaching treatment leads to demineralization in the enamel surface. The acidic peroxide-containing bleaching agent was the major cause of demineralization, whereas cold-light did not exhibit significant increase or decrease effect on this demineralization.

Effects of dexamethasone and vitamin B12 on expression of fibroblast growth factor 10 and fibroblast growth factor receptor 2b during early palatogenesis / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To observe the alteration of fibroblast growth factor 10 (Fgf10) and fibroblast growth factor receptor 2 (Fgfr2b) signal in mouse embryonic palate after dexamethasone and vitamin B12 exposure.</p><p><b>METHODS</b>Dams were divided teratogenetic group, antagomistic group and control group and were respectively injected dexamethasone, dexamethasone and vitamin B12, and normal sodium. Dams were killed and fetus was collected at embryo 12.5 and 13.5 day. The expression of Fgf10 and Fgfr2b and mesenchymal cells proliferation of mouse embryonic by western blotting and BrdU assay were checked.</p><p><b>RESULTS</b>Fgf10 and Fgfr2b expression was down-regulated and mesenchymal cells proliferation was inhibited significantly after dexamethasone exposure. After vitamin B12 treatment, Fgf10 and Fgfr2b expression did not restore, but cells proliferation was recovered.</p><p><b>CONCLUSION</b>Dexamethasone and vitamin B12 affected the expression of Fgf10 and Fgfr2b of mouse embryonic palate and mesenchyme cells proliferation, but the change was disaccord.</p>

Analyzing the inhibition of vitamin B12 to dexamethasone-induced palatognathous mouse using 1H-nuclear magnetic resonance based metabonomics method / 华西口腔医学杂志

<p><b>OBJECTIVE</b>Metabonomic analysis has been increasingly used to monitor metabolic abnormalities in cells and their micro-environment in order to detect the biomarkers recently. This study evaluated the feasibility of applying 1H-nuclear magnetic resonance (1H-NMR) based metabonomic method to detect the differences of the early development of cleft palate in the plasma from control group and experimental group.</p><p><b>METHODS</b>Pregnant mice (inbred C57BL/6J strain) with vitamin B12 injected only were assigned as the control group, pregnant mice with excessive Dex, injected after vitamin B12 as the experimental group, each group includes 12 mice. And the effect of B12 to rate of cleft palate was observed. The technology of nuclear magnetic resonance (NMR) was used to detect the endogenous small molecule metabolites. Finally, changes of metabolites ingredients were ascertained by using the method of principal component analysis (PCA).</p><p><b>RESULTS</b>There was significant difference in PCA scores plot between the two groups according to whether cleft palate occurred.</p><p><b>CONCLUSION</b>The 1H-NMR based metabonomic approach might be used as a feasible and efficient method for a deep exploration of the pathogenesis of cleft lip and palate and an early exploration of the mechanism of vitamin B12.</p>

Effect of cold-light bleaching technique on human permanent teeth enamel surface / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the effects of the cold-light bleaching technique on crystals and microstructure of the dental enamel.</p><p><b>METHODS</b>The human premolars extracted for orthodontic reasons were treated by a standard cold-light bleaching procedure. After the treatment, all samples were detected by high resolution micro-area X-ray diffractometer, Fourier transform infrared spectroscope and scanning electron microscope.</p><p><b>RESULTS</b>After the permanent teeth were treated with cold-light bleaching technique, the enamels' crystal dimension, crystallinity decreased and irregular surfaces and shallow disk pits appeared.</p><p><b>CONCLUSION</b>The cold-light bleaching technique could lead to the changes of crystals and microstructure in the surface layer of dental enamel.</p>

A preliminary investigation on plasma of non-syndromic cleft lip and/or palate using nuclear magnetic resonance-based metabonomics / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To access the feasibility of employing metabonomics method in clinical studies. This pilot study intends to introduce nuclear magnetic resonance (NMR)-based metabonomics method to elucidate the metabolism of non-syndromic cleft lip and/or palate (NSCLP) patients.</p><p><b>METHODS</b>High-resolution 1H NMR spectroscopy was performed on blood plasma obtained from NSCLP and non-malformed children. All signal of 1H NMR spectra were recognized within MESTRE-v4.7, and the 1H NMR spectra integration into bins (or buckets) across the spectral regions of bin 0.04 was performed automatically in MESTRE-v4.7. The resulting data matrix was further analyzed, which was performed by SIMCA-P 11.0. The principal component analysis (PCA) was applied to the centered data to explore any clustering behavior of the samples.</p><p><b>RESULTS</b>The results demonstrated the metabonomic difference in plasma between NSCLP and non-malformed children at least lies in 3-Hydroxybutyrate gamma-CH3, arginine and valine. Arginine excretion appeared to be higher in the non-malformed children population, while NSCLP population excreted higher concentrations of 3-Hydroxybutyrate gamma-CH3 and valine.</p><p><b>CONCLUSION</b>The present study clearly demonstrated the great potential of the NMR-based metabonomics approach in elucidating the NSCLP plasma metabolism and the possibility of application in clinic diagnosis and screening.</p>

Initial study on the discrimination of oral microorganisms with a metabonomics method / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To establish the spectra of metabolites that coued be employed in identification of oral pathogenic bacteria, and try to find a convenient and rapid way to discriminate oral microorganisms.</p><p><b>METHODS</b>Suspensions of Streptococcus mutans ATCC 25175, Streptococcus sanguis ATCC 10556 and Lactobacillus acidophilus ATCC 4356 with same density were preparecd and cultured respectively at improved TPY liquid culture medium. The growth quantity were measured periodically by a turbidimeter. And the growth curves of the inoculated bacteria were completed. The culture solutions in stationary phase of the three bacteria were tested with 1H-nuclear magnetic resonance (1H-NMR) spectroscopy respectively. The data of 1H-NMR spectroscopy results were analyzed by principal components analysis (PCA).</p><p><b>RESULTS</b>The PCA showed the obvious clustering phenomena and the points of three group differentially centralized to three clusters. Therefore, the NMR-based metabonomics profiles could discriminate the three different kinds of bacteria.</p><p><b>CONCLUSION</b>The metabonomics is a promising new technology for developing to a rapid discrimination method of oral pathogenic bacteria.</p>

Initial study on discrimination of oral microorganisms with the metabonomics technique / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the feasibility of employing metabonomics method in identification of oral pathogenic bacteria.</p><p><b>METHODS</b>The Streptococcus mutans ATCC25175 and Actinomyces viscosus ATCC15987 were respectively inoculated in same certain culture medium. The growth curves of the inoculated bacteria were drown by turbidimetry. The culture solutions in four different growth phases of the both bacteria were used to test with the 1H-Nuclear magnetic resonance (1H-NMR) spectroscopy respectively. The data of 1H-NMR spectroscopy results were analyzed by principal components analysis (PCA).</p><p><b>RESULTS</b>The PCA showed the obvious clustering phenomena and the points of two group data stayed differentially together by two clusters. Therefore, the NMR-based metabonomics profiles can discriminate the two different kind of bacteria.</p><p><b>CONCLUSION</b>The metabonomics can be expected to be a kind of promising useful method in quick discrimination of oral pathogenic bacteria.</p>

IL-10 inhibits inducible expression pattern of beta-defensin-2 in human peripheral blood cells / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effect of IL-10 on the inducibility of human beta-defensin 2 (hBD-2) in human peripheral blood cells.</p><p><b>METHODS</b>Peripheral blood samples were collected from 22 healthy individuals and co-cultured with 0 ng/ml lipopolysaccharide (LPS), 100 ng/ml LPS, 10 ng/ml IL-10, or 100 ng/ml LPS plus 10 ng/ml IL-10 at 37 degree for 6 h. Total RNA was extracted from peripheral blood cells and the mRNA level of hBD-2 was detected by relative quantitative real-time PCR..</p><p><b>RESULT</b>No detectable level of hBD-2 mRNA was found in normal peripheral blood cells with stimulation of 0 ng/ml LPS or 10 ng/ml IL-10. The mRNA level of hBD-2 was increased to 166.9 +/- 35.14 after 100 ng/ml LPS challenge, while the mRNA level of hBD-2 was decreased to 30.40 +/- 9.18 after the co-stimulation of 100 ng/ml LPS plus 10 ng/ml IL-10; which was significantly lower than that with LPS alone (P<0.05).</p><p><b>CONCLUSION</b>The expression of hBD-2 gene can be induced by LPS.IL-10 inhibits the inducible expression of hBD-2.</p>