Biomedical subjects

H Yoshie

Publications and source records attributed to H Yoshie.

At least 37 records · Page 2Linked to original sources

PubMed2001

Interleukin-10 gene promoter polymorphism in Japanese patients with adult and early-onset periodontitis.

BACKGROUND: IL-10 is an anti-inflammatory cytokine, which may modulate disease expression in chronic inflammatory periodontal disease. 3 dimorphic polymorphisms within the IL-10 gene promoter have recently been identified and appear to influence regulation of its expression. AIM: The aim of the present study was to investigate whether the promoter polymorphisms are associated with adult periodontitis (AP) and generalized early-onset periodontitis (G-EOP). METHODS: Genomic DNA was obtained from 34 AP patients, 18 G-EOP patients and 52 controls. The promoter region between -506 and -1140 was amplified by polymerase chain reaction, and polymorphisms were detected by nucleotide sequencing. RESULTS: The haplotype frequencies in Japanese were quite different from those of Caucasian and were even slightly different from those of southern Chinese with systemic lupus erythematosus. We found no significant difference in allele or haplotype frequencies between patients and controls. CONCLUSIONS: IL-10 production may be regulated within the complex cytokine network in chronic inflammatory periodontal disease, rather than the gene polymorphisms.

Adult↗

PubMed2001

Elevated mRNA expression for supervillin and vascular endothelial growth factor in human neutrophils stimulated with lipopolysaccharide from Porphyromonas gingivalis.

Differential gene expression was examined in human neutrophils stimulated with lipopolysaccharide from Porphyromonas gingivalis (P. gingivalis-LPS) using RNA fingerprinting by arbitrarily primed polymerase chain reaction (RAP-PCR). LPS from Escherichia coli (E. coli-LPS) was used as control. More than 200 differently expressed transcripts were found in 8 subjects showing differential regulation at the transcriptional level. Densitometric analyses revealed that 42-100 genes were upregulated, while 53-116 genes were downregulated by P. gingivalis-LPS compared with E. coli-LPS. The results of sequencing identification showed the presence of supervillin (SVIL) and vascular endothelial growth factor (VEGF) genes in the clones which were upregulated by P. gingivalis-LPS. Consequently, semiquantitative analyses proved that the level of mRNA for SVIL and VEGF were significantly higher in P. gingivalis-LPS-stimulated neutrophils than in other bacterial (E. coli, Actinobacillus actinomycetemcomitans, Prevotella intermedia) LPS- or synthetic lipid A-stimulated neutrophils. Our findings suggest that an elevated mRNA expression for SVIL could be associated with impaired function of neutrophils when stimulated by P. gingivalis-LPS. Further, the VEGF mRNA over-expression might be related to the pathogenesis of P. gingivalis-associated periodontitis. The RAP-PCR technique used in this study enabled us to identify a number of P. gingivalis-LPS regulated genes which hitherto have not been reported.

Adult↗

PubMed2001

Levels of tissue inhibitor of metalloproteinases-1 and matrix metalloproteinases-1 and -8 in gingival crevicular fluid following treatment with enamel matrix derivative (EMDOGAIN).

The mechanism of enamel matrix derivative (EM D) action on the periodontal wound healing process is not well understood. However, earlier in vitro studies from our laboratory demonstrated that EMD stimulated the proliferation of both periodontal ligament and gingival fibroblast cells. Therefore, the purpose of this study was to further evaluate the effect of EMD on the early wound healing process by assessing the protein levels of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in gingival crevicular fluid (GCF). Sixteen patients, each of whom had one or two pairs of infrabony defects located contralaterally in the same arch, were included in this clinical trial. Thirty-six infrabony defects were randomly assigned treatment with flap surgery plus EMD or flap surgery plus placebo. At baseline and at 2, 4 and 12 week follow-up evaluation visits, GCF was sampled with paper strips. After determination of GCF volume, TIMP-1, MMP-1 and MMP-8 GCF levels were measured by an enzyme-linked immunosorbent assay. Intragroup analysis: At week 2 following surgery, when compared to baseline all parameters in each study group, except MMP-1, significantly increased (p<0.05). There were no significant differences between 4 or 12 weeks and baseline in either study group. Intergroup analysis: At 4 weeks after surgery, GCF volume and TIMP-1 levels showed a significant decrease (p<0.05) in the EMD group, when compared to the placebo group. MMP-1 levels at weeks 2, 4 and 12, and MMP-8 levels at weeks 4 and 12 were significantly lower (p < 0.05) in the EMD group compared to the placebo group. EMD compared to placebo treated sites demonstrated a more rapid return to baseline levels of TIMP-1, MMP-1 and MMP-8. These findings suggest that treatment with flap surgery and EMD, compared to flap surgery with placebo, accelerated healing at an earlier stage of wound healing following surgery.

Alveolar Bone Loss↗

PubMed2001

Enamel matrix derivative (EMDOGAIN) rapidly stimulates phosphorylation of the MAP kinase family and nuclear accumulation of smad2 in both oral epithelial and fibroblastic human cells.

In our previous study, we demonstrated that porcine enamel matrix derivative (EMD) induces p21WAF1/cip1 within 8 hours and subsequently arrests the cell cycle of human oral epithelial cells in G1 phase. In contrast, EMD markedly stimulates the proliferation of gingival fibroblasts without inducing p21WAF1/cip1. To investigate the mechanism of how EMD produces these differential effects, we have focused on the initial response of these two cell types to EMD. In epithelial cell cultures, EMD stimulated cytoskeletal actin polymerization within 30 min and promoted cell adhesion in our experimental system. EMD failed to stimulate either intracellular Ca2+ mobilization or cAMP production in either cell type. In both epithelial and fibroblastic cells, EMD (25-100 microgram/ml) rapidly produced dose-dependent phosphorylation of the mitogen-activated protein kinase (MAPK) family: extracellular signal response kinase (ERK), p38-MAPK (p38-K), and c-Jun-terminal kinase/stress-activated protein kinase (JNK). However, neither inhibitors of MEK (ERK kinase) nor p38-K could block EMD's anti-proliferative action on epithelial cells. On the other hand, EMD rapidly stimulated translocation of smad2 into the nucleus in both cell types. Spurred by this finding, we assayed for TGF-beta1, a ligand for one receptor associated with smad2 activation, and detected significant levels in EMD preparations. The sum of these pharmacological findings indicates that EMD contains at least one bioactive factor, which is most probably TGF-beta1 (or TGF-beta-like substances). In conjunction with the similarities in the differential growth-modulating actions between EMD and what is known for TGF-beta, we suggest that TGF-beta might act as the principal growth regulating agent of oral fibroblastic and epithelial cell types in EMD despite being present in only low levels.

Actins↗

PubMed2001

Differential gene expression in neutrophils from patients with generalized aggressive periodontitis.

Differential gene expression was investigated in neutrophils stimulated with N-formyl-methionyl-leucyl-phenylalanine using RNA fingerprinting by arbitrarily primed polymerase chain reaction (RAP-PCR). The cells were isolated from 3 groups of subjects: patients with generalized aggressive periodontitis (Aggressive-P. n = 6), generalized chronic periodontitis (Chronic-P, n = 6) and healthy controls (H, n = 8). Our results show that 37 genes were upregulated. while 27 genes were down-regulated in all Aggressive-P neutrophils by using RAP-PCR with 45 primer pairs. Reverse transcription-PCR analyses revealed that mRNA levels were significantly different (p<0.05) for heat shock transcription factor 4b (HSF4b) gene. Kruppel-like zinc finger transcription factor 9 (Zf9) and muskelin genes. HSF4b was greater in neutrophils from Aggressive-P compared to groups H and Chronic-P. Zf9 and muskelin genes were lower in Aggressive-P compared to the H groups, but no significant difference was noted compared to the Chronic-P group. The control genes, IL-1beta and VEGF genes, were expressed at a significantly higher level in Aggressive-P and Chronic-P than H (p<.01, p<0.05). In conclusion, the RAP-PCR technique used in this study enabled us to identify 3 Aggressive-P related genes, which had not been reported previously. Neutrophil functions in Aggressive-P patients are suggested to be altered by regulatory factors of the immune system including HSF4b (transcription factor), Zf9 (activator of TGF-beta) and muskelin (cellular adhesion).

Adult↗

PubMed2001

Effective in vitro clearance of Porphyromonas gingivalis by Fc alpha receptor I (CD89) on gingival crevicular neutrophils.

Porphyromonas gingivalis has been implicated as a causative pathogen in periodontitis. Immunotherapeutic approaches have recently been suggested to aid in the clearance of P. gingivalis from disease sites. Because antibody-Fc receptor (FcR) interactions play a role in the effector functions of polymorphonuclear neutrophils (PMN), we evaluated which FcR on PMN from gingival crevicular fluid (GCF) serves as an optimal target molecule for FcR-directed immunotherapy. GCF PMN and peripheral blood (PB) PMN from adult periodontitis patients were analyzed for their immunoglobulin G (IgG) and IgA FcR (Fc gamma R and Fc alpha R, respectively) expression and function by studying IgG- and IgA-mediated elimination of P. gingivalis. GCF PMN exhibited higher Fc alpha RI and Fc gamma RI levels and lower Fc gamma RIIa and Fc gamma RIIIb levels than PB PMN. Functional studies revealed that GCF PMN exhibited less of a capacity to phagocytose and kill IgG1-opsonized P. gingivalis than PB PMN. IgA1-mediated phagocytosis and killing capacity was, however, comparable between GCF PMN and PB PMN. In summary, these in vitro results document that Fc alpha RI represents a candidate target for FcR-directed immunotherapy for the clearance of P. gingivalis.

Adult↗

PubMed2001

Increased frequency of FcgammaRIIIb-NA1 allele in periodontitis-resistant subjects in an elderly Japanese population.

Many elderly people show minimum periodontal tissue destruction, which might be partly due to genetic advantages in host immune response against periodontopathic bacteria. The human IgG Fc receptor IIIb on neutrophils bears a NA1-NA2 polymorphism. The FcgammaRIIIb-NA1 displays a more efficient interaction with IgG1- and IgG3-opsonized bacteria, compared with the FcgammaRIIIb-NA2. We investigated a 70-year-old Japanese population (n = 599) to determine whether the FcgammaRIIIb polymorphism was associated with resistance to periodontitis. Among subjects with > or = 20 teeth present, periodontitis-resistant (n = 46) and periodontitis-susceptible groups (n = 73) were selected based on the percentage of sites with > or = 4 mm probing attachment loss in the entire dentition. The FcgammaRIIIb-NA1 allotype was overrepresented in the periodontitis-resistant group, compared with the periodontitis-susceptible group (chi2 = 4.89, p = 0.03, odds ratio = 1.87, 95% CI, 1.07 to 3.28). This suggests that FcgammaRIIIb-NA1 may be associated with resistance to periodontitis.

Aged↗

PubMed2001

The Fc gamma receptor genotype as a severity factor for chronic periodontitis in Japanese patients.

BACKGROUND: Functional polymorphisms of immunoglobulin G (IgG) Fc receptors (Fc gamma R) have been shown to be associated with generalized aggressive periodontitis (GAgP) or recurrence of chronic periodontitis (CP) in Japanese patients. The purpose of this study was to evaluate whether Fc gamma R polymorphisms are also associated with severity of CP. METHODS: Fifty Japanese non-smoking patients with severe CP and 39 Japanese non-smoking patients with moderate CP were identified according to established clinical criteria, including measurements of probing depth (PD), clinical attachment level (CAL), and alveolar bone loss (BL). Fc gamma R genotypes for 3 bi-allelic polymorphisms (Fc gamma RIIa-R/H131, Fc gamma RIIIa-158V/F, Fc gamma RIIIb-NA1/NA2) were determined in these CP patients and 64 race-matched, non-smoking healthy controls by means of allele-specific polymerase chain reactions. RESULTS: There was a significant over-representation of Fc gamma RIIIa-158V allele in severe CP patients compared to moderate CP patients (odds ratio 2.03, 95% confidence interval [CI] 1.03-4.01, chi 2 = 4.86, P = 0.028). In addition, we found a strong association between CP severity and Fc gamma R composite genotype comprising Fc gamma RIIIa-158V plus Fc gamma RIIIb-NA2 (severe CP versus moderate CP: odds ratio 4.69, 95% CI 1.52-15.10, chi 2 = 9.35, P = 0.002; severe CP versus healthy controls: odds ratio 4.10, 95% CI 1.62-10.59, chi 2 = 11.13, P = 0.0009). Moreover, CP patients positive for the composite genotype exhibited more severe signs of periodontitis than composite genotype-negative individuals (positive versus negative; mean PD: 3.8 mm versus 3.2 mm, P = 0.005; mean CAL: 4.5 mm versus 3.7 mm, P = 0.005; mean % BL: 37.6% versus 29.9%, P = 0.008). CONCLUSION: Our results document the Fc gamma RIIIa-158V allele and possibly Fc gamma RIIIb-NA2 to be associated with severity of CP in Japanese patients.

Adult↗

PubMed2001

Analysis of single nucleotide polymorphisms in the 5'-flanking region of tumor necrosis factor-alpha gene in Japanese patients with early-onset periodontitis.

BACKGROUND: Early-onset periodontitis (EOP) is considered to have a genetic basis, which has not been clearly defined. The tumor necrosis factor-alpha (TNF-alpha) gene polymorphism as one of the genetic factors may influence the expression of several chronic inflammatory diseases. The aim of the present study was to evaluate whether the polymorphisms in the 5'-flanking region of the TNF-alpha gene are associated with Japanese EOP patients. METHODS: Forty-six Japanese, generalized EOP (G-EOP) patients and 104 Japanese healthy subjects were identified according to established clinical criteria. Twenty healthy subjects were analyzed by nucleotide sequence to screen polymorphisms of the 5'-flanking region of the TNF-alpha gene. Then, all subjects were analyzed by polymerase chain reaction and sequence-specific oligonucleotide probe (SSOP) methods. RESULTS: We determined 5 single nucleotide polymorphisms at positions -1031 (T/C), -863 (C/A), -857 (C/T), -308 (G/A), and -238 (G/A) in the 5'-flanking region of the TNF-alpha gene. There were no significant differences in the genotype and allele frequency when we compared G-EOP patients to healthy subjects. Because the frequency of polymorphic alleles at positions -308 and -238 was very low in this study population, we demonstrated the existence of 4 detected haplotypes and 6 detected genotypes concerning 3 single nucleotide polymorphisms (-1031, -863, and -857). The frequency of the H1/H3 (TCC/TCT)-detected genotype tended to decrease in G-EOP patients compared to healthy subjects, but was not statistically significant. CONCLUSION: These findings suggest there is no significant association between polymorphisms in the 5'-flanking region of the TNF-alpha gene and susceptibility to G-EOP in Japanese patients.

5' Flanking Region↗

PubMed2000

A novel PCR-based method for direct Fc gamma receptor IIIa (CD16) allotyping.

Leukocyte IgG receptors (Fc gamma R) are important immune-response modulating molecules. Fc gamma RIIIa is expressed on macrophages, NK-cells and gamma delta-T cells and exhibits a genetically determined, functional polymorphism at nucleotide 559. This allelic difference predicts either a phenylalanine (F158) or valine (V158) at amino acid 158 in the membrane-proximal extracellular domain, and has been shown to be associated with autoimmune and infectious diseases. Published methods to determine Fc gamma RIIIa genotypes are cumbersome. Therefore, we developed a novel, rapid and reliable PCR-based method to determine Fc gamma RIIIa genotypes. Comparison of genotyping results with direct Fc gamma RIIIa sequencing of 60 blood donors showed 100% accuracy of this new method. Since genotype frequencies of Fc gamma R polymorphisms depend strongly on race and ethnicity, we compared Fc gamma RIIIa genotype frequencies of 176 Caucasian Dutch and 104 Japanese blood donors. Interestingly, these frequencies were not significantly different (P>0.1), in contrast to the Fc gamma RIIa and Fc gamma RIIIb genotype frequencies (P<0.001).

Alleles↗

PubMed2000

Tissue inhibitor of metalloproteinases-1, matrix metalloproteinases-1 and -8, and collagenase activity levels in peri-implant crevicular fluid after implantation.

The integrity of connective tissues surrounding dental implants may be influenced by a balance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). The purpose of this study was to provide an overall assessment of TIMP-1, MMP-1 and -8 levels as well as collagenase activities during the wound healing process after implantation and in peri-implantitis lesions. Peri-implant crevicular fluid (PICF) was sampled with sterile paper strips from 10 osseointegrated implants of 6 subjects. Ten implants from 6 patients affected with peri-implantitis were also assessed. Gingival crevicular fluid (GCF) from 11 periodontitis-affected patients and 10 healthy volunteers served as controls. TIMP-1 and MMP-1 and -8 protein levels in the PICF were measured by ELISA, and active and APMA-activatable collagenase activities were determined by functional assays using image-analysis after SDS-PAGE. The experiment showed a significant increase in the TIMP-1 level at 1 week after implantation as compared with that in GCF from healthy periodontium. Four weeks after implantation it had reached the same level as that in the GCF of healthy subjects. The data has also disclosed a higher post-implantation collagenase activity level at 1 week than at weeks 2, 4, and 12. This may be due to the increase in MMP-1 and -8. Furthermore, peri-implantitis and periodontitis were shown to be similar inflammatory lesions in respect to MMP-1 and -8 and collagenase activities, even though the TIMP-1/MMP-1 + MMP-8 ratio was significantly lower in peri-implantitis than in periodontitis. In conclusion, the overproduction of TIMP-1 in the wound area after implantation could, to some extent, inhibit excessive tissue destruction and degradation of the neo-matrix in wound repair due to MMPs.

Adult↗

PubMed2000

Relevance of IgG receptor IIIb (CD16) polymorphism to handling of Porphyromonas gingivalis: implications for the pathogenesis of adult periodontitis.

Polymorphonuclear neutrophils (PMNs) are essential in host defense against periodontopathic bacteria such as Porphyromonas gingivalis. The uptake of immunoglobulin G (IgG)-opsonized bacteria via IgG Fc receptors (Fc gamma R) on PMN constitutes a central defense mechanism in periodontium. Fc gamma RIIIb is the most abundantly expressed Fc gamma R on PMN and is functionally polymorphic. The Fc gamma RIIIb-NA1 and IIIb-NA2 allotypes interact differently with IgG1- and IgG3-opsonized particles. We recently showed recurrence rates of adult periodontitis (AP) to be higher in patients carrying at least 1 Fc gamma RIIIb-NA2 allele. In this study we evaluated the functional relevance of the Fc gamma RIIIb polymorphism to anti-P. gingivalis PMN effector functions. Our results showed Fc gamma RIIIb-NA2-carrying PMN from both patients with AP and healthy controls to be less efficient in phagocytosis and induction of oxidative burst upon interaction with IgG1- and IgG3-opsonized P. gingivalis. These functional differences between Fc gamma RIIIb-NA1 and IIIb-NA2 were observed in the presence of CD32-blocking antibody fragments, but not upon blocking CD16. Moreover, PMNs from AP patients exhibited increased Fc gamma RIIIb-allelic differences in IgG3-induced oxidative burst compared to control PMNs. These results support the concept that Fc gamma RIIIb heterogeneity may influence the clinical course of AP.

Adult↗

PubMed2000

Cytostatic action of enamel matrix derivative (EMDOGAIN) on human oral squamous cell carcinoma-derived SCC25 epithelial cells.

During surgical treatment of periodontal disease, enamel matrix derivative (EMD) is topically applied as a substitute for extracellular matrix in order to facilitate regeneration of damaged periodontal tissue. However, the mechanism for EMD action is poorly understood. We have now examined the effects of EMD on the proliferation of oral epithelial (SCC25) cells in vitro. After 3 days of treatments, EMD (25 100 microg/ml) dose-dependently inhibited cell division and concomitantly arrested cell cycle at the G1 phase. Prior to this inhibition, EMD significantly up-regulated p21WAF1/cip1, a cyclin-dependent kinase inhibitor, induced G1-arrest, and inhibited DNA synthesis. In addition, EMD down-regulated expression of cytokeratin-18 (CK18) protein, which was most due to decreased production, but less to increased degradation. However, EMD did not discernibly increase the number of apoptotic cells over 8 days of treatment. These findings indicate (1) that EMD acts as a cytostatic agent, rather than a cytotoxic agent, on epithelial cells, and (2) that this anti-proliferative action is probably due to p21WAF1/cip1-mediated G1-arrest. Furthermore, our in vitro cellular data clearly verify and provide an explanation for the clinical observation that EMD application suppresses the down-growth of junctional epithelium onto dental root surfaces, a process that frequently interferes with the formation of new connective tissue attachments.

Adolescent↗

PubMed2000

Elevated CTLA-4 expression on CD4 T cells from periodontitis patients stimulated with Porphyromonas gingivalis outer membrane antigen.

To characterize the T cell response to Porphyromonas gingivalis, we examined the expression of costimulatory molecules on T cells derived from adult periodontitis patients with high serum antibody titre to P. gingivalis. The expression of CD28, CTLA-4, CD40 ligand (CD40L) on CD4+ T cells was analysed by flow cytometry. IL-10 and transforming growth factor-beta (TGF-beta) mRNA expression were determined by reverse transcription-polymerase chain reaction (RT-PCR) and subsequent image analysis. Peripheral blood mononuclear cells (PBMC) derived from periodontitis patients showed higher proliferative responses to P. gingivalis outer membrane (OM) than those from healthy controls (P < 0.05). The percentage of CTLA-4+ cells within CD4+ T cells of patients was significantly higher than that of healthy controls after P. gingivalis OM stimulation (33.0% versus 11.9%, P < 0.01). There was no significant difference in the percentages of CD28+ cells and CD40L+ cells, and the percentage of CD40L+ cells was low in both groups even after stimulation. Stimulation of PBMC with P. gingivalis OM induced significantly higher IL-10 mRNA expression in periodontitis patients than in healthy controls (P < 0.05). The level of TGF-beta mRNA expression of patients tended to be higher than that of healthy controls, but there was no significant difference. To elucidate the functional role of CTLA-4, we further investigated the secondary proliferative response to P. gingivalis OM. Interestingly, P. gingivalis OM stimulation did not enhance antigen-specific secondary response. Anti-CTLA-4 MoAb had no effect on proliferation in the presence of P. gingivalis OM. CTLA-4Ig suppressed the proliferative response significantly (P < 0.01). These results suggest that T cell responses to P. gingivalis OM may be regulated by CTLA-4 that is expressed at the late phase of T cell activation, and, in part, immunosuppressive cytokines. Taken together, CTLA-4 may play a crucial role in the pathogenesis of chronic inflammatory periodontal disease.

Abatacept↗

PubMed2000

Selective expansion of T cells in gingival lesions of patients with chronic inflammatory periodontal disease.

Chronic inflammatory periodontal diseases are characterized by a cellular infiltrate and are similar in many respects to other chronic inflammatory diseases. While periodontopathic bacteria have been recognized as the principal causative agent and the immune response to these bacteria is thought to be responsible for the tissue destruction, the full aetiological spectrum is still incompletely understood. In addition to many cell types such as polymorphonuclear leucocytes and macrophages, T cells have been implicated in pathogenesis and are considered to have regulatory roles in progression of the disease. Based on our recent studies demonstrating biased expression of several Vbeta families in periodontitis tissues, the aim of this study was to characterize further the T cells relevant to the disease process by reverse transcription-polymerase chain reaction-single-strand conformation polymorphism (RT-PCR-SSCP) and subsequent nucleotide sequence analysis of complementarity-determining region 3 (CDR3) of the TCR beta-chain. In spite of the likely involvement of numerous bacteria, the present study has clearly shown the oligoclonality of infiltrating T cells in periodontitis lesions in contrast to low clonality of peripheral blood T cells as evidenced by the appearance of distinct bands in gingival tissue samples and smear pattern of peripheral blood on SSCP gels. These were confirmed by the DNA sequencing of the CDR3 of Vbeta16 of selected samples. The analysis of deduced amino acid sequences demonstrated amino acid motifs in the CDR3 region of the periodontitis lesion-derived sequences from each patient. The results indicate that gingival tissue-infiltrating T cells recognizing a limited number of antigens or epitopes are involved in the disease process.

Adult↗

PubMed2000

Elevated humoral immune response to heat shock protein 60 (hsp60) family in periodontitis patients.

The presence of antibodies to the 60-kD human and Porphyromonas gingivalis GroEL hsp60 in the sera and inflamed gingival tissues of periodontitis patients was examined. In order to obtain the antigens, recombinant plasmids carrying human hsp60 and P. gingivalis GroEL genes were constructed and expressed as histidine-tagged recombinant proteins. Immunoreactivities of these proteins were confirmed by MoAbs specific to mammalian hsp60 and cross-reactive with both mammalian and bacterial hsp60. Western blot analysis clearly demonstrated that the number of periodontitis patients showing a positive response to P. gingivalis GroEL was higher than the number of periodontally healthy subjects. Furthermore, anti-P. gingivalis GroEL antibody was detected in all samples of gingival tissue extracts. For human hsp60, a higher frequency of seropositivity was found in the periodontitis patients than in the healthy subjects. In addition, the periodontitis patients demonstrated stronger reactivity compared with the healthy subjects. Quantitative analysis of serum antibodies by ELISA also demonstrated that the levels of antibodies in the sera of patients were significantly higher than those of control subjects. In the gingival tissue extracts, seven out of 10 patients demonstrated a positive response to human hsp60 and tso of these demonstrated strong positivity. Affinity-purified serum antibodies to human hsp60 and P. gingivalis GroEL from selected patients reacted with P. gingivalis GroEL and human hsp60, respectively, suggesting cross-reactivity of antibodies. These results suggest that molecular mimicry between GroEL of the periodontopathic bacterium P. gingivalis and autologous human hsp60 may play some role in immune mechanisms in periodontitis.

Adult↗

PubMed2000

Toll-like receptors confer responsiveness to lipopolysaccharide from Porphyromonas gingivalis in human gingival fibroblasts.

Gingival fibroblasts produce proinflammatory cytokines in response to lipopolysaccharide (LPS) from periodontopathic bacteria. Recently it has become evident that the human homologue of Drosophila Toll can transduce intracellular signaling by LPS stimulation. Toll-like receptors (TLRs) have been identified in myeloid cells; however, their role in nonmyeloid cells such as gingival fibroblasts has not been fully elucidated. Here, we report that human gingival fibroblasts constitutively express TLR2 and TLR4 and that their levels of expression are increased by stimulation with LPS from Porphyromonas gingivalis. Upregulated expression of interleukin-6 gene and protein in fibroblasts stimulated with LPS is inhibited by anti-TLR4 antibody. These findings suggest that TLRs may confer responsiveness to LPS in gingival fibroblasts.

Cells, Cultured↗

PubMed2000

Enamel matrix derivative in the treatment of human intrabony osseous defects.

BACKGROUND: There is limited information available from clinical trials regarding the performance of enamel matrix derivative (EMD) in the treatment of periodontal intrabony defects. This randomized, double-blind, placebo-controlled, split-mouth study was designed to compare the clinical and radiographical effects of EMD treatment to that of placebo-controlled treatment for intrabony defects. METHODS: Sixteen patients were included, each of whom had 1 or 2 pairs of intrabony defects located contralaterally in the same arch. Thirty-six intrabony defects were randomly assigned treatment with flap surgery plus EMD or flap surgery plus placebo. At baseline and at the 12-month follow-up evaluation visit, clinical and radiographic measurements were determined. Data were statistically analyzed using the Wilcoxon-signed rank test (alpha = 0.05). RESULTS: At the 12-month visit, bleeding on probing for the EMD group was 0.11 +/- 0.32 compared to the placebo group, 0.61 +/- 0.50 (P <0.05). Probing depth reduction was greater in the EMD group (3.00 +/- 0.97 mm) compared to the placebo group (2.22 +/- 0.81 mm) (P <0.05). Mean values for clinical attachment gain in the EMD and the placebo groups were 1.72 +/- 1.07 mm and 0.83 +/- 0.86 mm, respectively (P <0.05). Vertical relative attachment gain was 38.5 +/- 22.6% in the EMD group and 21.4 +/- 25.2% in the placebo group (P<0.05). Radiographic bone density gain was greater in the EMD (20.2 +/- 16.6%) compared to the placebo group (-3.94 +/- 23.3%) (P<0.01). CONCLUSIONS: Treatment with flap surgery and EMD, compared to flap surgery with placebo, produced a significantly more favorable clinical improvement in intrabony periodontal defects.

Adult↗