Comparison of Serum Hepatitis B Virus RNA Levels and Quasispecies Evolution Patterns between Entecavir and Pegylated-Interferon Mono-treatment in Chronic Hepatitis B Patients.

Hepatitis B virus (HBV) RNA may independently predict virological and serological response. This study aimed to compare dynamic changes in serum HBV RNA levels and HBV quasispecies evolution patterns between entecavir and pegylated-interferon mono-treatment in chronic hepatitis B patients and to determine the clinical significance during treatment. TaqMan real-time PCR was used for quantitative analysis. HBV RNA levels were retrospectively determined in serial serum samples from 178 chronic hepatitis B patients who received either entecavir or pegylated-interferon treatment. Both serum HBV DNA and RNA quasispecies were analyzed via next-generation sequencing. Receiver operating characteristics (ROC) analysis was performed to evaluate the prediction value of individual biomarkers for hepatitis B e antigen (HBeAg) seroconversion. Patients who received pegylated-interferon treatment showed stronger declines in HBV RNA levels than did those who received entecavir treatment. Serum HBV RNA levels were lower in patients with subsequent HBeAg seroconversion. At baseline, the level of HBV RNA was better than other indicators in predicting HBeAg seroconversion. Moreover, the predictive value of serum HBV RNA levels was better in the entecavir group. Baseline HBV RNA exhibited a significantly higher genetic diversity than HBV DNA and had a significant decline after 4 weeks of entecavir treatment. Higher baseline genetic diversity may result in a better outcome in pegylated-interferon-treated patients. Serum HBV RNA levels showed different decline kinetics, and HBV RNA quasispecies showed different evolution patterns in entecavir and pegylated-interferon mono-treatment. Taken together, serum HBV RNA may serve as a promising biomarker of HBeAg seroconversion in patients during antiviral treatment.

Serum M2BPGi level is a novel predictive biomarker for the responses to pegylated interferon-α treatment in HBeAg-positive chronic hepatitis B patients.

Serum Mac-2-binding protein glycosylation isomer (M2BPGi) level was found to be a useful prognostic marker for hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) patients treated with nucleoside/nucleotide analogs (NUCs) therapy, and the aim of our study is to evaluate the clinical implementation of M2BPGi level in the prediction of antiviral responses to pegylated-interferon-α (PEG-IFN-α) treatment in HBeAg-positive CHB patients. Ninety-six CHB patients who received PEG-IFN-α treatment for at least 48 weeks were recruited. The serum M2BPGi, alanine aminotransferase (ALT), hepatitis B surface antigen (HBsAg), HBeAg, and HBV DNA levels at baseline, weeks 4, 12, and 24 after PEG-IFN-α treatment were determined and their associations with antiviral responses were evaluated and the virological response (VR) rate and serological response (SR) rate after 48 weeks of treatment were 65.6% and 35.4%, respectively. Baseline serum M2BPGi level was significantly different between VR and non-VR (P = 0.002) or SR and non-SR groups (P = 0.012). Multivariate analyses suggested that baseline serum M2BPGi level was independently associated with VR and SR of PEG-IFN-α treatment at week 48. The area under the ROC curve (AUC) of baseline M2BPGi was 0.682 in predicting VR, which was superior to HBsAg (AUC = 0.566) or HBV DNA (AUC = 0.567). The AUC of baseline M2BPGi in predicting SR was 0.655, which was also higher than that of HBsAg (AUC = 0.548) or HBV DNA (AUC = 0.583). These results suggested that baseline serum M2BPGi level was a novel predictor of VR and SR for PEG-IFN-α treatment in HBeAg-positive CHB patients.

Effect of erbium family laser etching on shear bond strength of enamel surfaces: A meta-analysis-PRISMA.

BACKGROUND: Recently, laser etching has appealed to people's attention. It is meaningful to compare the effect of erbium-doped yttrium-aluminum-garnet (Er:YAG) and erbium-chromium; yttrium-scandium-gallium-garnet (Er,Cr:YSSG) laser etching parameters with acid etching on bond strength of enamel surfaces. As far as we know, there still remains no related meta-analysis. To evaluate the efficacy of Er:YAG and Er,Cr:YSSG lasers etching on shear bond strength (SBS) of brackets bonded to enamel. The meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, conducted with literature search. METHODS: Twelve relevant randomized controlled trials (RCTs) were included. RESULTS: The pooled analysis of SBS showed that there were no significant differences between erbium family lasers and acid etching. In the mass, we noticed they did not achieve statistical significance in the lasers etching and acid etching. However, pooled analysis of 5 studies showed the SBS bonding to enamel was lower in Er,Cr:YAG laser group compared with acid group. As a whole, there were statistical significance between erbium lasers groups and acid etching group in adhesive remnant index (ARI) aspects, which less adhesives remained can reduce damage to enamel. With regard to the rate of teeth with ARI score ≤2, the results in Er:YAG laser etching group were obviously higher than acid etching group. CONCLUSION: Our data indicated that erbium lasers may be considered bonding of brackets to enamel instead of acid etching bonding to enamel.

[Knockdown of MSX2 gene inhibits the expression of enamel matrix proteins and the enamel mineralization in mouse ameloblasts].

Objective To study the effect of muscle segment homeodomain homeobox 2 (MSX2) on the expression of enamel matrix protein and the formation of enamel. Methods Immunohistochemical staining was used to detect the expression of MSX2 in mouse tooth embryos and its localization in ameloblasts. The short hairpin RNA (shRNA) of the MSX2 gene was designed and synthesized, and then the annealed double stranded DNA was constructed into the pGMLV-SC5 RNAi lentivirus vector, and finally it was packaged with lentivirus. The lentivirus was used to infect ameloblasts. Real-time fluorescent quantitative PCR was performed to screen the best interference fragment, and detect the mRNAs of amelogenin (Amelx), ameloblastin (Ambn), enamelin (Enam), amelotin (Amtn) and kallikrein 4 (Klk4). The embryos were isolated for 18.5 days and then infected with RNAi recombinant lentivirus targeting MSX2. The tooth germ was implanted under the renal capsule of the mouse. Ten weeks later, the tissue was harvested to separate and observe the tooth form and contour. Results MSX2 was expressed in the secretory phase and maturation phase of mouse ameloblasts, but the expression signal was weaker in the secretory phase and was stronger in the mature stage. The lentivirus of MSX2-shRNA targeting MSX2 gene we constructed inhibited the expression of Amelx and Klk4 mRNAs. The RNAi lentivirus targeting MSX2 gene infected the tooth enamel and led to a decrease in the degree of enamel mineralization. Conclusion The MSX2 gene is expressed in ameloblasts. The knockdown of MSX2 can inhibit the expression of enamel matrix proteins and the enamel mineralization.

MxA induction may predict sustained virologic responses of chronic hepatitis B patients with IFN-alpha treatment.

The objective of this study was to find potential biomarkers for predicting sustained virologic responses to interferon-alpha (IFN-alpha) treatment in chronic hepatitis B (CHB) patients. A total of 101 CHB patients were treated with pegylated IFN-alpha2a for 48 weeks and followed up for 24 weeks, including 34 IFN responders (IFN-Rs) and 67 IFN nonresponders (IFN-NRs). After peripheral blood mononuclear cells (PBMCs) and Epstein-Barr virus-transferred B (EBV-B) cell lines were treated with different concentrations of IFN-alpha in vitro, activated IFN-stimulated gene factor3 (ISGF3) and IFN-gamma-activation factor (GAF) were measured by EMSA, and MxA, OAS1, and PKR mRNA were measured by real-time PCR. Polymorphisms in the MxA promoter were genotyped to find the possible association. IFN-alpha-activated ISGF3 and GAF levels were similar between IFN-NRs and IFN-Rs. However, MxA mRNA induction in IFN-Rs was higher than that in IFN-NRs, and such discrepancy increased when highly concentrated IFN was used to stimulate. The OAS1 and PKR mRNA induction have a similar pattern between IFN-Rs and IFN-NRs. In addition, frequency of the MxA-88G/T genotype was significantly different between IFN-Rs and IFN-NRs, and this polymorphism was also functional because MxA mRNA induction in patients with GG genotype was lower than those with GT genotype. Regression analysis showed that MxA mRNA induction after 10,000 IU/mL IFN stimulation could serve as an independent factor for predicting IFN-alpha, with an area under curve (AUC) of 0.838, a positive predictive value of 68% for IFN-Rs, and a negative predictive value of 89% for IFN-NRs. MxA mRNA induced by IFN-alpha might predict sustained virologic responses to IFN-alpha treatment in CHB patients.

Quantitative hepatitis B surface antigen combined with hepatitis B e antigen as sustained virological response predictors during extended therapy with Peginterferon alfa-2a for hepatitis B e antigen-positive chronic hepatitis B.

BACKGROUND: The best strategy for chronic hepatitis B patients with poor response to 48 weeks of Peginterferon-based therapy has been controversial and the predictive value of hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg) and hepatitis B virus (HBV) DNA levels for determining the sustained virological response (SVR) of these patients is uncertain. OBJECTIVES: To optimize management of these patients and evaluate the use of these serobiomarkers to predict SVR. STUDY DESIGN: Eighty-one patients with an unsatisfactory response after 48 weeks of Peginterferon-based therapy were treated with extended Peginterferon therapy with or without nucleo(s) tide analogues (NAs), for a total of 96 weeks of Peginterferon treatment. HBsAg, HBeAg and HBV DNA levels were measured serially during the treatment and follow-up. RESULTS AND CONCLUSIONS: Twenty-six of 81 patients (32.1%) attained SVR during the 72-week follow-up. The SVR rate was not statistically different between groups receiving 1-year prolongation of Peginterferon with or without NAs. The serum HBsAg cut-off of 1800IU/mL at week 48 had area under curve (AUC) of 0.727, and the serum HBsAg cut-off of 1500IU/mL, combined with HBeAg loss at week 72, had AUC of 0.753 to predict SVR during the follow-up. In conclusion, extended treatment with Peginterferon with or without NAs for patients with unsatisfactory response after 48 weeks of Peginterferon-based therapy is a promising strategy to achieve SVR, and quantitative serum HBsAg at week 48 and HBsAg level combined with HBeAg loss at week 72 of therapy can predict SVR to prolongation therapy with Peginterferon.

Influence of inner circular sealing area impression method on the retention of complete dentures.

The aims of the present study were to describe an impression method of "inner circular sealing area" and to evaluate the effect of the method on retention, aesthetics and comfort of complete dentures, which lack labial base for patients with maxillary protrusions. Three patients were subjected to the experiment, and two sets of complete maxillary dentures were made for each patient; the first set was made without labial base via an inner circular sealing area method (experimental group) and the second had an intact base that was made with conventional methods (control group). Retention force tests were implemented with a tensile strength assessment device to assess the retention and a visual analogue scale (VAS) was used to evaluate the comfort between the two groups. Results showed larger retention force, better aesthetics and more comfort in the experimental group. The improved two-step impression method formed an inner circular sealing area that prevented damage to the peripheral border seal effect of the denture caused by incomplete bases and obtained better denture retention.

[Macrophage migration-inhibitory factors expression and its effects on proliferation in human dental pulps].

OBJECTIVE: To investigate the expression of macrophage migration-inhibitory factors (MIF) in clinically healthy and inflamed human pulp tissues and the effects of rhMIF on the proliferation of human dental pulp cells (HDPC). METHODS: Immunohistochemistry was used to detect the localization of MIF expression in clinically healthy pulp and inflamed pulp tissues. Quantitative real-time polymerase chain reaction (PCR) was performed to evaluate the mRNA levels of MIF in pulp specimens. In addition, the culture supernatants of HDPC were collected after HDPC was stimulated by lipopolysaccharide (LPS) for 24 h, and then the MIF levels were assayed by quantitative sandwich enzyme-linked immunosorbent assay. Meanwhile, the effects of rhMIF on the proliferation of HDPC at different concentrations for 24 and 48 h were observed by cell counting kit-8 (CCK-8). RESULTS: MIF was mainly distributed in odontoblasts of healthy pulp tissue, however, in inflamed pulp tissue, it was widely detected in fibroblasts, inflammatory infiltrates and endothelial cells as well as odontoblasts. Quantitative real-time PCR showed that there was no significant difference in MIF mRNA levels between inflamed pulps and healthy pulps (P > 0.05). Additionally, the secretion of MIF was significantly increased by stimulation with LPS at the concentration of 0.1 and 1.0 mg/L [(1772.58 ± 495.05), (1692.58 ± 337.45) ng/L] (P < 0.05), and the concentration was (1048.53 ± 161.81) ng/L in control group. rhMIF stimulated the HDPC's proliferation at the concentration of 10, 30, 60 µg/L for 24 and 48 h. CONCLUSIONS: MIF was expressed in pulp tissue and its expression was increased after stimulation by LPS. rhMIF increased the proliferation of HDPC. These results suggest that MIF may be involved in the process of pulpal inflammation.

Evaluation of cell tracking effects for transplanted mesenchymal stem cells with jetPEI/Gd-DTPA complexes in animal models of hemorrhagic spinal cord injury.

Cell tracking using iron oxide nanoparticles has been well established in MRI. However, in experimental rat models, the intrinsic iron signal derived from erythrocytes masks the labeled cells. The research evaluated a clinically applied Gd-DTPA for T1-weighted positive enhancement for cell tracking in spinal cord injury (SCI) rat models. MSCs were labeled with jetPEI/Gd-DTPA particles to evaluate the transfection efficiency by MRI in vitro. Differentiation assays were carried out to evaluate the differentiation ability of Gd-DTPA-labeled MSCs. The Gd-DTPA-labeled MSCs were transplanted to rat SCI model and monitored by MRI in vivo. Fluorescence images were taken to confirm the MRI results. Behavior test was assessed with Basso, Beattie, and Bresnahan (BBB) scoring in 6weeks after cell transplantation. The Gd-labeled MSCs showed a significant increase in signal intensity in T1-weighted images. After local transplantation, Gd-DTPA-labeled MSCs could be detected in SCI rat models by the persistent T1-weighted positive enhancement from 3 to 14days. Under electronic microscope, Gd-DTPA/jetPEI complexes were mostly observed in cytoplasm. Fluorescence microscopy examination showed that the Gd-labeled MSCs survived and distributed within the injured spinal cord until 2weeks. The Gd-labeled MSCs were identified and tracked with MRI by cross and sagittal sections. The BBB scores of the rats with labeled MSCs transplantation were significantly higher than those of control rats. Our results demonstrated that Gd-DTPA is appropriate for cell tracking in rat model of SCI, indicating that an efficient and nontoxic label method with Gd-DTPA could properly track MSCs in hemorrhage animal models.

Association of genetic variation in IL28B with hepatitis C treatment-induced viral clearance in the Chinese Han population.

BACKGROUND: Genome-wide association studies have recently shown that the rs12979860 polymorphism in IL28B is associated with the response to chronic hepatitis C treatment. The aim of this study was to investigate whether rs12979860 could be used as a predictive marker for end-of-treatment response (ETR) or sustained virological response (SVR) in the Chinese Han population. METHODS: The rs12979860 genotype was detected in 259 individuals infected with HCV by DNA sequencing. Among them, 120 patients were administered complete pegylated interferon-α and ribavirin combination therapy and 92 patients were followed for 24 weeks after the cessation of treatment and were divided into different groups according to outcomes of treatment. RESULTS: The rs12979860 genotype CC was the primary genotype (87.64%, 227/259) and genotype TT was found in only one individual within this cohort. The patients with the rs12979860 genotype CC had higher rates of ETR (P=0.0044) and SVR (P=0.0046) than the patients with N-CC (CT or TT). In multivariate analyses, the rs12979860 genotype CC was associated with a substantial difference in rates of achieving ETR (odds ratio [OR] 8.983, 95% confidence interval [CI] 2.173-37.145; P=0.0024) and SVR (OR 24.298, 95% CI 2.27-259.90; P=0.0083). CONCLUSIONS: This study demonstrated for the first time that the rs12979860 variation in IL28B could be a predictor of ETR and SVR in Chinese Han patients infected with HCV. The high frequency of the rs12979860 genotype CC might explain why the SVR rate is higher than that of the average global population.

Regulation of the stromal cell-derived factor-1alpha-CXCR4 axis in human dental pulp cells.

INTRODUCTION: Although the presence of the stromal cell-derived factor (SDF)-1alpha-CXCR4 axis has been reported in dental pulp tissue, little has been known about the underlying regulation of this axis in dental pulp stem cells (DPSCs). The purpose of this study was to investigate whether inflammation or hypoxia can regulate this axis in cultured human dental pulp cells (DPCs). METHODS: Primary cultures of DPCs were stimulated by various concentrations of lipopolysaccharide (LPS) for 48 hours, and the production of SDF-1alpha or CXCR4 was assessed through the enzyme-linked immunosorbent assay and Western blotting, respectively. Additionally, DPCs were incubated in a hypoxic condition (1% O(2)) for 24 hours, and the cell proliferation ability was detected by methylthiazol tetrazolum assay. Quantitative reverse-transcription polymerase chain reaction (RT-PCR) was used to observe messenger RNA level changes of hypoxia inducible factor-1alpha(HIF-alpha), SDF-1alpha, and CXCR4. The effects of hypoxia on cell migration ability were further confirmed by transmigration assay. RESULTS: All concentrations of LPS inhibited SDF-1alpha production except that 1 microg/mL LPS increased the expression of CXCR4. Hypoxia promoted the proliferation of DPCs in a 24-hour culture period. Quantitative RT-PCR showed that messenger RNA levels of HIF-alpha and CXCR4 increased, whereas SDF-1alpha decreased in hypoxic DPCs. Transmigration assay indicated that hypoxia increased the migration ability of DPCs. CONCLUSIONS: These results suggested that inflammation and hypoxia might play an important role in regulating the SDF-1alpha-CXCR4 axis, which further recruits DPSCs to participate in reparative dentinogenesis.

Influence of Inner Circular Sealing Area Impression Method on the Retention of Complete Dentures

The aims of the present study were to describe an impression method of "inner circular sealing area" and to evaluate the effect of the method on retention, aesthetics and comfort of complete dentures, which lack labial base for patients with maxillary protrusions. Three patients were subjected to the experiment, and two sets of complete maxillary dentures were made for each patient; the first set was made without labial base via an inner circular sealing area method (experimental group) and the second had an intact base that was made with conventional methods (control group). Retention force tests were implemented with a tensile strength assessment device to assess the retention and a visual analogue scale (VAS) was used to evaluate the comfort between the two groups. Results showed larger retention force, better aesthetics and more comfort in the experimental group. The improved two-step impression method formed an inner circular sealing area that prevented damage to the peripheral border seal effect of the denture caused by incomplete bases and obtained better denture retention.

O objetivo deste caso foi descrever um método de impressão por "área de selamento circular interno" e avaliar o efeito deste método na retenção, estética e conforto de próteses totais sem base labial para pacientes com protrusão maxilar. Três pacientes foram objeto desta experiência e foram feitas duas próteses maxilares completas para cada um deles; a primeira foi elaborada sem base labial pelo método de área de selamento circular interno (grupo experimental) e a outra teve uma base feita pelo método convencional (grupo controle). Foram realizados testes de retenção com estudo de tensão para avaliar a retenção e para avaliação do conforto dos dois grupos, foi empregada a escala analógica visual (EAV). Os resultados demonstraram que o grupo experimental apresentou força de retenção maior, estética melhor e mais conforto. O método modificado de impressão em duas etapas formou uma área de selamento circular interno que evitou danos ao selamento periférico causados por bases incompletas e obteve melhor retenção da prótese.

HSP25 affects the proliferation and differentiation of rat dental follicle cells.

AIM: To detect the expression of HSP25 in rat dental follicles both in vivo and vitro, and explore the underlying mechanism of HSP25 on the proliferation and differentiation of rat dental follicle cells (DFCs). METHODOLOGY: Immunohistochemistry was performed to detect the expression of HSP25 in mandibles of postnatal rats on days 1, 3, 5, 7, 9 and 11 in vivo. In vitro, the expression of HSP25 in DFCs was detected by an indirect immunofluorescence assay. Thiazolyl blue tetrazolium bromide (MTT) assay, flow cytometry and alkaline phosphatase (ALP) assay were used to identify the time-course effect mediated by different concentrations of recombinant murine HSP25 of 0, 1, 10, 50 and 100 ng/mL on rat DFCs. RESULTS: Expression of HSP25 was not detected in dental follicles of the rats until day 5 after birth, but became up-regulated in a time-dependent manner till day 11. HSP25 was detected in the cytoplasm of cultured rat DFCs. No significant difference could be observed in the proliferation of DFCs after stimulation with different concentrations of HSP25 on days 1, 2 and 3 (P > 0.05). HSP25 at concentrations of 50 ng/mL and 100 ng/mL up-regulated the ALP activity of DFCs on day 9 (P < 0.05). CONCLUSION: HSP25-immunoreactivity increased chronologically during the development of dental follicles. The protein had no significant effect on cell proliferation but may play a role in cementoblast/osteoblast differentiation of DFCs.

[Expression and biological roles of heat shock protein 25 in rat dental follicle cells].

OBJECTIVE: To examine the expression of heat shock protein 25 (HSP-25) in dental rat follicles in vivo and in vitro in order to investigate the possible effect of HSP-25 on cell proliferation and alkaline phosphatase (ALP) activity. METHODS: The expression of HSP-25 in mandibles of postnatal rats from day 1, 3, 5, 7, 9, 11 was examined by immunohistochemistry in vitro, the expression of HSP-25 in the dental follicle cells was detected by the indirect immunofluorescence method. Methyl thiazolyl tetrazolium (MTT) assay, flowcytometry and ALP assay were used to detect the effect of HSP-25 on rat dental follicles. RESULTS: HSP-25 expression was absent or weak in rat dental follicle cells at early postnatal stage and present from day 5 till day 11. HSP-25 was detected in the cytoplasm of cultured dental follicle cells. MTT results showed no effect could be detected on dental follicle cell proliferation after stimulation of different concentrations of HSP-25 on day 1, 2, 3. Flowcytometry results also exhibited no difference in cell cycles after stimulation of HSP-25 at 0 microg/L and 100 microg/L. HSP-25 at a concentration of 50 microg/L and 100 microg/L could up-regulate the ALP activity on day 9. CONCLUSIONS: Expression of HSP-25 increases chronologically in the rat dental follicle cells. HSP-25 locates in the cytoplasm of cultured rat dental follicle cells. HSP-25 has no effect on the proliferation of dental follicle cells, however it can up-regulate the ALP activity.

[Preliminary study on the discrimination of putative periodontal pathogens with a metabonomics method].

OBJECTIVE: To evaluate the feasibility of identifying oral pathogenic bacteria by comparing the metabolic profiling of putative periodontal pathogens and try to find a convenient and rapid way to discriminate oral microorganisms. METHODS: Suspensions of Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum with same density were prepared and cultured respectively at liquid BHI medium. Then the growth quantity was measured periodically through turbidimetry and the growth curves of the inoculated bacteria were completed. The culture solutions of stable growth phase were sampled and characterized by 1H-nuclear magnetic resonance 1H-NMR). The data of 1H-NMR spectroscope results were analyzed by principal components analysis (PCA). RESULTS: The PCA showed the obvious clustering phenomena and the points of three groups differentially centralized to three clusters. Therefore, the NMR-based metabonomics profiles could discriminate the three different kinds of bacteria. CONCLUSION: The metabonomics is a potential classable method to identify the oral pathogenic bacteria.

The expression of stromal cell-derived factor 1 (SDF-1) in inflamed human dental pulp.

Although dental pulp progenitor/stem cells (DPSCs) are indispensable for repair after pulpal injury, the mechanisms regulating their recruitment and activation remain unknown. To address this issue, we evaluated whether DPSCs in inflamed dental pulp had an upregulation of the chemokine system, a system of proteins known to regulate cellular responses to inflammation. Stromal cell-derived factor 1 (SDF-1), a member of the CXC chemokine subfamily and its receptor CXC chemokine receptor 4 (CXCR4), were evaluated in inflamed dental pulps obtained from extracted human teeth that showed spontaneous pain and/or lingering pain in response to cold and/or heat stimulus and compared with control levels found in normal dental pulps obtained from healthy noncarious third molars. Using immunohistochemistry and real-time reverse-transcription polymerase chain reaction, the results indicated that in inflamed pulps the SDF-1/CXCR4 axis was mostly distributed in inflammatory cells and microvascular endothelial cells rather than in normal pulps. SDF-1 messenger RNA expression levels in clinically inflamed dental pulp were higher than those in healthy dental pulp. These findings suggest that SDF-1 plays an important role in the process of pulpal inflammation via the recruitment of CXCR4-expressing inflammatory cells, and the SDF-1/CXCR4 axis may be involved in the recruitment of dental pulp stem cells at the injury site.

[Study the inhibitory effects of three oral actinomyces on growth of oral Candida albicans in vitro].

OBJECTIVE: The aim of this study was to investigate whether the three species of oral Actinomyces have inhibitory effects on the growth of oral Candida albicans in vitro. METHODS: Straight o'clock method was used to observe the bacteriostasis circle. Reverse o'clock and mixed culture method were used to study the quantitative changes of Candida albicans colony respectively. RESULTS: (1) None of the groups had been viewed the bacteriostasis circle. (2) Compared with control groups, there was a significant decrease of Candida albicans colony on Actinomyces viscosus TPY soft agar (P < 0.05). Actinomyces naeslundii and Actinomyces odontolyticus TPY soft agar were both devoid of obvious Candida albicans colony (P < 0.01). The former group (Actinomyces viscosus) and the two latter groups (Actinomyces naeslundii and Actinomyces odontolyticus) showed a striking contrast (P < 0.01). (3) Compared with control groups, a decrease of Candida albicans showed up in the mixed culture, and the difference was significant (P < 0.05). The discrepancies among the three experimental groups were of no statistical value (P > 0.05). CONCLUSION: Oral Actinomyces viscosus, Actinomyces naeslundii and Actinomyces odontolyticus could inhibit the growth of Candida albicans in vitro. However, which of them contributed more to the inhibitory effects was still not affirmed.

[Expression and significance of stromal cell-derived factor-1alpha and its receptor CXCR4 in human dental pulp cells].

OBJECTIVE: To investigate the expression of CXCR4 in cultured human dental pulp cells (HDPC) in vitro and the corresponding ligand SDF-1alpha level of HDPC supernatants stimulated by lipopolysaccharide (LPS) and tumor necrosis factor-alpha (TNF-alpha), and to explore the role of SDF-1alpha on the proliferation and the migration of HDPC. METHODS: The expression of CXCR4 in HDPC was detected by immunocytochemistry technique and indirect immunofluorescence technique. The culture supernatants of HDPC were collected after HDPC had been simulated by LPS and TNF-alpha of different concentrations for 48h and then the SDF-1alpha level was assayed by quantitative sandwich ELISA. Meanwhile, the effects of recombinant human SDF-1alpha (rhSDF-1alpha) on the proliferation and the migration of HDPC at different concentrations were observed by MTT and Boyden Chamber Assay. RESULTS: CXCR4 was expressed in cytomembrane of HDPC and SDF-1alpha was secreted into their normal cell supernatants with a concentration of (4513.55 +/- 962.92) ng/L. The secretion of SDF-1alpha was both significantly decreased by stimulation with LPS and TNF-alpha (P < 0.05). In addition, rhSDF-1alpha stimulated the HDPC proliferation at the concentrations of 50, 100, 200 microg/L (P < 0.01) and increased the chemotactic migration of HDPC significantly after 9h's incubation with the concentrations of 50, 100 microg/L (P < 0.05). CONCLUSIONS: SDF-1alpha accelerated the proliferation and the migration of HDPC which expressed CXCR4. SDF-1-CXCR4 axis may play a role in repair of pulp injury.