Min Nie

Wuhan University, Wuhan, Hubei, China

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Publications (10)9.08 Total impact

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    ABSTRACT: To evaluate the shaping ability of hand-used ProTaper on curved canals using Endodontic Cube. Fifty-four curved root canals in vitro were selected and divided into three groups according to the curved degree (alpha), group A: 0 degrees < or = alpha < 25 degrees , group B: 25 degrees < or = alpha < 40 degrees , group C: 40 degrees < or = alpha < 55 degrees . Endodontic Cube was assembled, and each sample was sectioned perpendicular to the axis of the tooth into four sections with Isomer-Buhler in low speed. Then the root canals were prepared with hand-used ProTaper. Before and after shaping, photograph of all the sections were taken under a stereomicroscope. Statistical analyses were performed. The dentin cutting quantity of the whole canal prepared with ProTaper in group B and C was larger than that of group A. The deviation distance of the whole canal prepared by ProTaper in group C was significantly larger than that in group A, and the deviation distance in middle portion larger than that in group B. The maintaining ability in the middle portion of group C by ProTaper was worse than that of group A and B. The curvature of root canal may increase the cutting quantity of the -dentin and reduce the ability of remaining original canal shape prepared by ProTaper.
    Zhonghua kou qiang yi xue za zhi = Zhonghua kouqiang yixue zazhi = Chinese journal of stomatology 06/2009; 44(5):262-5.
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    ABSTRACT: Porphyromonas gingivalis, a major periodontopathic bacterium, is necessary for periodontitis to take place. The lipopolysaccharide (LPS) of P. gingivalis stimulates cytokine secretion in immune cells, and thereby initiates the inflammation related to periodontitis. Macrophages are the important ones of the immune cells that are prominent at inflammatory periodontal sites. Curcumin, a major curcumanoid found in the spice turmeric, exhibits anti-inflammatory properties. The aim of this study was to investigate the anti-inflammatory effect and the mechanism of action of curcumin in macrophages stimulated by P. gingivalis LPS. RAW264.7 cells pre-treated with various concentrations of curcumin were stimulated by P. gingivalis LPS. TNF-alpha and IL-1beta expressions were separately detected by RT-PCR and ELISA. Next, activation of NF-kappaB-dependent transcription was examined by luciferase assay. Results: Curcumin dose-dependently inhibited TNF-alpha and IL-1beta gene expression and protein synthesis in RAW264.7 cells stimulated with P. gingivalis LPS. P. gingivalis LPS activated NF-kappaB-dependent transcription in RAW264.7 cells, which were down-regulated by pre-treatment with curcumin as well. Our data suggest that curcumin can inhibit P. gingivalis LPS-induced cytokine expression, and that this could be due to the inhibition of the NF-kappaB pathway.
    Pharmacology 11/2008; 82(4):264-9. DOI:10.1159/000161127 · 1.58 Impact Factor
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    ABSTRACT: To analyze the different responses of dental pulp to moderate caries and thermal stimulation by proteomics. Two-dimensional electrophoresis(2-DE) was performed to obtain the 2-D gel electrophoresis patterns of dental pulp. Mass spectrometry (MS) was used to analyze several different selected spots in the expression proteins. No significant difference in protein expression was found between normal and moderate carious dental. Two protein spots were absent in heat-damaged group and 8 spots showed significantly down-regulated. Seven proteins were identified by MS. In the present study, no significant difference in the pulp protein expression was detected between the healthy and moderate carious pulp tissues. However, down-regulation of pulp protein in thermal stimulation was observed.
    Zhonghua kou qiang yi xue za zhi = Zhonghua kouqiang yixue zazhi = Chinese journal of stomatology 04/2008; 43(3):154-6.
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    ABSTRACT: To determine whether the glucan binding protein C (GbpC) with LPXAG motif is anchoring to the cell wall of the Streptococcus mutans UA159 (S. mutans UA159). S. mutans UA159 GbpC C terminal gene segment was amplified by PCR, the gene sequences and the deduced amino acid sequences were analyzed. In order to locate the GbpC of S. mutans, the study isolated the wall fraction following digestion of the cell wall by N-acetylmuramidase, and the GbpC was detected by Western blot analysis. GbpC S. mutans UA159 was located with gold particles. Furthermore, the dextran-dependent aggregation (ddag) phenotype of the S. mutans UA159 under stress condition was observed. S. mutans UA159 GbpC C-terminal LPXTG motif was replaced by LPXAG motif. GbpC was observed in the cell wall component and immunogold experiment showed that the gold particles distributed around the cell wall surface. S. mutans UA159 exhibited ddag+. GbpC with LPXAG motif was still anchoring to the cell wall.
    Zhonghua kou qiang yi xue za zhi = Zhonghua kouqiang yixue zazhi = Chinese journal of stomatology 07/2007; 42(6):349-52.
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    ABSTRACT: The purpose of this study was to compare the salivary immunoglobulin A antibody response to Streptococcus mutans in normal with in heat treated stress. Clinical Streptococcus mutans strains were isolated from 20 volunteers, serotyped by biochemical test and PCR, and genotyped by AP-PCR. Unstimulated secretions from submandibular glands and sublingual glands were collected from volunteers by modified collectors. Each identified genotype was cultured in two groups: control group was grown in BHI broth at 37 degrees C. for 3 hours; stress group was incubated in BHI broth at 42 degrees C. for 3 hours. Analysis of SIgA activity to clinical genotype strains and reference strains in different group was detected by Western blot. There was no significant difference between stress group and control group,in spite that some bands had strong or weak intensity. Different genotypes of S.mutans could have different immunoblotting profile as for an individual. SIgA from different volunteers could have different immonoblotting profiles as to the same genotype strain. Although Streptococcus mutans can express heat shock proteins in stress, this study suggests these new proteins have no significant effect on the reaction of SIgA to Streptococcus mutans. Different genotype strains may have different proteins, and different immunoreactivity to host. Different hosts may have different immunoreactivities to one genotypes of S.mutans.
    Shanghai kou qiang yi xue = Shanghai journal of stomatology 07/2006; 15(3):285-9.
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    ABSTRACT: To test the salivary immunoglobulin A antibody activity to Streptococcus mutans in normal with in acid environment. Streptococcus mutans strains were isolated from 20 volunteers, serotyped by biochemical test and PCR, and genotyped by AP-PCR. Unstimulated secretions from submandibular glands and sublingual glands were collected from volunteers by modified collectors. Each identified Streptococcus mutans genotype was cultured in two groups: control group was cultured in BHI broth pH7.2 at 37 degrees C for 2 h; acid shock group were cultured in TYEG broth (pH5.5) at 37 degrees C for 2 h. Analysis of SIgA activity to Streptococcus mutans genotypes in different groups was detected by Western blot. (1) The SIgA of each individual could response to his own Streptococcus mutans strains and the reference strains; (2) The same individual had different SIgA activity to different genotype strains; (3) There were no significant difference between acid groups and control groups, in spite that some bands had strong or weak intensity. Although Streptococcus mutans could express acid shock proteins in stress, the present study suggests that these new proteins have no qualitative effect on the reaction of SIgA to Streptococcus mutans.
    Zhonghua kou qiang yi xue za zhi = Zhonghua kouqiang yixue zazhi = Chinese journal of stomatology 06/2005; 40(3):215-8.
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    ABSTRACT: The aim of the study was to examine the persistence of oral Streptococcus mutans in nasopharyngeal carcinoma patients after radiotherapy. Ten subjects, ranging in age from 20 to 67 years, participated. DMFT/DMFS, salivary level of mutans streptococci and oral health status were recorded. Pooled plaque samples were obtained from the cervical margins and the interproximal regions of all the teeth and the occlusal surfaces of the molars prior to, immediately after, 3 and 6 months after the completion of radiotherapy. At least 10 colonies of S. mutans were isolated from each subject and totally 645 isolates were genotyped by restriction endonuclease analysis. The results showed that the salivary level of S. mutans increased significantly with the reduction of salivary flow rate after radiotherapy. Each subject had at least 1 genotype of S. mutans isolated throughout the follow-up period. In 3 subjects who initially carried 2 or more genotypes, 1 or 2 genotypes of S. mutans could not be detected 3 months after treatment. Moreover, the genotypes that became undetectable were predominant bacteria in the first sampling. The result indicated that most S. mutans genotypes were persistent after radiotherapy but some genotypes that might not adapt to the alteration of oral environment became undetectable.
    Caries Research 01/2005; 39(6):484-9. DOI:10.1159/000088184 · 2.50 Impact Factor
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    ABSTRACT: The aim of this study was to clarify the genotypic stability of mutans streptococci (MS) longitudinally during orthodontic treatment. Plaque samples were obtained from the supragingival smooth surface of the upper right teeth at four stages: prior to and after 1, 3 and 6 months of orthodontic treatment. Levels of total viable count, total streptococci and MS in dental plaque of 17 patients were recorded. Streptococci isolated from dental plaque samples were identified as MS on the basis of their morphological and biochemical properties. DNA was prepared from 713 strains of MS and the strains were then identified with polymerase chain reaction (PCR) again. Arbitrarily primed PCR (AP-PCR) fingerprinting was applied in determining the genotypes of MS. The results indicated that levels of total viable count, total streptococci and MS increased significantly after the fixed appliances were bonded. A maximum of 3 different genotypes were found in an individual. All the genotypes were found again after the application of the fixed appliances in 17 patients. A new AP-PCR typing pattern was found after the application of fixed appliances for 1 month in patient 1. That strain was not detected either prior to or after 3, or 6 months of treatment. The result indicated that the MS clones were very stable during orthodontic treatment.
    Caries Research 01/2004; 38(6):523-9. DOI:10.1159/000080581 · 2.50 Impact Factor
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    ABSTRACT: To extract the effective ingredient (crystal I) from effective section (saponin) of Ligustrum Lucidum Ait, identify the chemical structure of crystal I, study the effect of crystal I on P. gingivalis, B. forsythus and P. intermedia. Isolated crystal I from saponin using the silica gel column chromatograph. Identified crystal I with IR spectra, (1)H-NMR and (13)C-NMR. Measured the minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) through micro-liquid dilution. Studied the killing curve of ursolic acid on B. forsythus and P. intermedia. The crystal I was identified as ursolic acid; its MIC and MBC to P. gingivalis, B. forsythus and P. intermedia were 0.740 and 0.295 microg/L respectively. The killing curve indicated that 0.800 microg/L ursolic acid could kill P. intermedia and B. forsythus in 3 and 6 hours respectively. Ursolic acid has obvious effect to inhibit periodontal pathogen.
    Zhonghua kou qiang yi xue za zhi = Zhonghua kouqiang yixue zazhi = Chinese journal of stomatology 10/2002; 37(5):388-90.
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    ABSTRACT: The purpose of this study was to investigate whether there was transmission between adults in Chinese families using chromosomal DNA fingerprinting. Plaque samples were obtained from buccal and occlusal surfaces of 11 married couples. The colonization levels of mutans streptococci were estimated as colony-forming units per milliliter, and caries experience was scored by decayed, missing and filled teeth. Information about medical history, diet regimes and age at marriage was obtained. The isolates were serotyped by biochemical test and genotyped using the restriction endonuclease HaeIII. The procedure was repeated after 3 months. The results showed that 1 couple had the same genotype of mutans streptococcus at the first examination, but this could not be repeated for the husband who had lost his mutans streptococci at the second examination. On the contrary, another couple that did not have the same mutans streptococcal genotype at the beginning had the same genotype after 3 months. No matching of genotypes was observed within 8 couples. In 1 male, no mutans streptococci were detected, therefore that couple was not considered. These data indicate that spouses had a chance to be infected by strains of mutans streptococci from another person. The results suggest that there may be transmission between adults in Chinese families, but it may be difficult for mutans streptococci to colonize another mouth permanently.
    Caries Research 01/2002; 36(3):161-6. DOI:10.1159/000059330 · 2.50 Impact Factor