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Aggregatibacter Actinomycetemcomitans (aggregatibacter + actinomycetemcomitan)
Selected AbstractsSalivary interleukin-1, concentration and the presence of multiple pathogens in periodontitisJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2009Ulvi Kahraman Gursoy Abstract Aim: This study aimed to find salivary enzymes and/or cytokines that would reflect periodontitis, alone or in combination with salivary microbial markers. Material and Methods: The salivary concentrations of elastase, lactate dehydrogenase, interleukin-1, (IL-1,), interleukin-6, and tumour necrosis factor- ,, and the presence of five periodontal pathogens, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, and Treponema denticola, were analysed from salivary specimens of 165 subjects, a subpopulation of Health 2000 Health Examination Survey in Finland; 84 of the subjects had probing pocket depth (PPD) of 4 mm at 14 or more teeth (the advanced periodontitis group), while 81 subjects had no teeth with PPD of 4 mm (the control group). All subjects had at least 20 teeth and no systemic diseases. Results: Among the salivary cytokines and enzymes tested, IL-1, was the only biomarker associated with periodontitis. An association was also found with the presence of multiple periodontal pathogens. Salivary IL-1, and the presence of multiple periodontal pathogens were associated with periodontitis at the same magnitude, when they were in the logistic regression model individually or together. Conclusion: We suggest that salivary IL-1, and the presence of multiple periodontal pathogens in saliva should be studied more thoroughly as markers of periodontitis. [source] An improved cost-effective, reproducible method for evaluation of bone loss in a rodent modelJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2009Daniel H. Fine Abstract Aim: This study was designed to investigate the utility of two "new" definitions for assessment of bone loss in a rodent model of periodontitis. Material and Methods: Eighteen rats were divided into three groups. Group 1 was infected by Aggregatibacter actinomycetemcomitans (Aa), group 2 was infected with an Aa leukotoxin knock-out, and group 3 received no Aa (controls). Microbial sampling and antibody titres were determined. Initially, two examiners measured the distance from the cemento-enamel-junction to alveolar bone crest using the three following methods; (1) total area of bone loss by radiograph, (2) linear bone loss by radiograph, (3) a direct visual measurement (DVM) of horizontal bone loss. Two "new" definitions were adopted; (1) any site in infected animals showing bone loss >2 standard deviations above the mean seen at that site in control animals was recorded as bone loss, (2) any animal with two or more sites in any quadrant affected by bone loss was considered as diseased. Results: Using the "new" definitions both evaluators independently found that infected animals had significantly more disease than controls (DVM system; p<0.05). Conclusions: The DVM method provides a simple, cost effective, and reproducible method for studying periodontal disease in rodents. [source] Antibody levels to single bacteria or in combination evaluated against myocardial infarctionJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 6 2008Lise Lund Håheim Abstract Background: Evidence is accumulating that oral bacteria are associated with myocardial infarctions (MI). We were interested in studying the differences in the association between single bacteria or bacteria in combination and the relation to C-reactive protein (CRP). Material and Methods: We examined the levels of antibodies against four major periodontal pathogens Porphyromonas gingivalis (PG), Aggregatibacter actinomycetemcomitans (AA), Tannerella forsythia (TF) and Treponema denticola (TD) and CRP in 548 men with a self-reported history of MI to 625 controls who took part in the Oslo II study in 2000. Results: The mean levels of bacterial antibodies were higher for the cases than the controls, but not significant as standard deviations were large. The level of CRP was higher in the cases than the controls (p=0.010). Logistic regression analyses comparing the upper quartile value with the lower value of one of either four antibodies (anti-AA, anti-TF, anti-TD and anti-PG) were significantly associated (p=0.032) with MI. Equivalent analyses of either three bacteria showed significant associations for anti-AA, anti-TD and anti-PG (p=0.036) and anti-AA, anti-PG and anti-TF (p=0.040). CRP showed an increased relative risk with increasing quartile value; trend, p=0.016, but not in multivariate analysis including the oral antigens. Conclusions: No single bacterium but rather combinations were related to increasing relative risk for MI independent of known cardiovascular risk factors. [source] Bleeding on probing differentially relates to bacterial profiles: the Oral Infections and Vascular Disease Epidemiology StudyJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 6 2008Ryan T. Demmer Abstract Aim: Various bacterial species are differentially prevalent in periodontal health, gingivitis or periodontitis. We tested the independent associations between three bacterial groupings and gingival inflammation in an epidemiological study. Material and Methods: In 706 Oral Infections and Vascular Disease Epidemiology Study (INVEST) participants 55 years, bleeding on probing (BoP), pocket depth (PD) and subgingival plaque samples (n=4866) were assessed in eight sites per mouth. Eleven bacterial species were quantitatively assayed and grouped as follows: (i) aetiologic burden (EB, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia); (ii) putative burden (PB, Campylobacter rectus, Eikenella corrodens, Fusobacterium nucleatum, Micromonas micros, Prevotella intermedia); (iii) health-associated burden (HAB, Actinomyces naeslundii, Veillonella parvula). Results: After mutual adjustment for EB, PB and HAB, the BoP prevalence increased by 45% ( p<0.0001) across increasing quartiles of EB while BoP decreased by 13% ( p<0.0001) across increasing quartiles of HAB. Mean PD increased 0.8 mm and decreased 0.3 mm from the first to fourth quartiles of EB (p<0.0001) and HAB ( p<0.0001), respectively. Among 1214 plaque samples with fourth quartile EB, 60% were collected from sites with PD 3 mm. Conclusion: Bacterial species believed to be aetiologically related to periodontitis were associated with BoP in sites with minimal PD and/or attachment level (AL). Species presumed to be associated with periodontal health demonstrated inverse associations with BoP. [source] The upregulation of heat shock protein 47 in human gingival fibroblasts stimulated with cyclosporine AJOURNAL OF PERIODONTAL RESEARCH, Issue 3 2010T.-Y. Chang Chang T-Y, Tsai C-H, Chang Y-C. The upregulation of heat shock protein 47 in human gingival fibroblasts stimulated with cyclosporine A. J Periodont Res 2010; 45: 317,322. © 2009 John Wiley & Sons A/S Background and Objective:, Heat shock protein 47 (Hsp47), a collagen-specific molecular chaperone, is involved in the processing and/or secretion of procollagen. Heat shock protein 47 is consistently and dramatically upregulated in a variety of fibrotic diseases. The aim of this study was to compare Hsp47 expression in normal gingival tissues and cyclosporine A-induced gingival overgrowth specimens and further explore the potential mechanisms that may lead to induction of Hsp47 expression. Material and Methods:, Fifteen cyclosporine A-induced gingival overgrowth specimens and five normal gingival tissues were examined by immunohistochemistry. Western blot was used to investigate the effects of cyclosporine A on the expression of Hsp47 in human gingival fibroblasts. In addition, Aggregatibacter actinomycetemcomitans, interleukin-1, (IL-1,) and mitogen-activated protein kinase kinase (MEK) inhibitor U0126 were added to seek the possible regulatory mechanisms of Hsp47 expression. Results:, A significantly higher percentage of cells positively stained for Hsp47 was noted in the cyclosporine A-induced gingival overgrowth group than in the normal gingival group (p < 0.05). Expression of Hsp47 was observed mainly in the cytoplasm of fibroblasts, endothelial cells, epithelial cells and inflammatory cells. Expression of Hsp47 was significantly higher in cyclosporine A-induced gingival overgrowth specimens with higher levels of inflammatory infiltrates (p < 0.05). Cyclosporine A upregulated Hsp47 expression in human gingival fibroblasts in a dose-dependent manner (p < 0.05). The addition of A. actinomycetemcomitans or interlukin-1, significantly increased Hsp47 expression compared with cyclosporine A alone (p < 0.05). The MEK inhibitor U0126 was found to inhibit cyclosporine A-induced Hsp47 expression (p < 0.05). Conclusion:, Expression of Hsp47 is significantly upregulated in cyclosporine A-induced gingival overgrowth specimens, and Hsp47 expression induced by cyclosporine A in fibroblasts may be mediated by the MEK signal transduction pathway. The expression of Hsp47 could be significantly enhanced by A. actinomycetemcomitans and interlukin-1,. [source] Neutrophils in chronic and aggressive periodontitis in interaction with Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitansJOURNAL OF PERIODONTAL RESEARCH, Issue 3 2009A. Guentsch Background and Objective:, This study analyzed the interaction of Porphyromonas gingivalis ATCC 33277 and Aggregatibacter actinomycetemcomitans Y4 with peripheral blood polymorphonuclear neutrophils taken from patients with aggressive periodontitis and chronic periodontitis. Material and Methods:, Peripheral blood polymorphonuclear neutrophils obtained from 12 patients with chronic periodontitis, six patients with aggressive periodontitis and 12 healthy controls were exposed to P. gingivalis and A. actinomycetemcomitans following opsonization of the bacteria using the patient's own serum. Serum immunoglobulin G (IgG) levels against both periodontopathogens were measured. Phagocytosis and killing of the bacteria, as well as the extracellular human neutrophil elastase activity, were quantified. The total amount and the extracellular release of reactive oxygen species were measured using luminol-dependent and isoluminol-dependent chemiluminescence. Results:, Polymorphonuclear neutrophils from patients with chronic (62.16 ± 19.39%) and aggressive (43.26 ± 26.63%) periodontitis phagocytosed more P. gingivalis than the healthy controls (24.43 ± 19.87%) at the 30-min time point after exposure to the bacteria (p < 0.05). High serum IgG levels against P. gingivalis and A. actinomycetemcomitans were detected in subjects with periodontitis. Polymorphonuclear neutrophils from subjects with chronic and aggressive periodontitis released significantly more reactive oxygen species and demonstrated greater human neutrophil elastase activity in the absence of any stimulus than polymorphonuclear neutrophils from healthy controls (p < 0.05). Polymorphonuclear neutrophils in chronic periodontitis released significantly more reactive oxygen species when exposed to P. gingivalis and A. actinomycetemcomitans than polymorphonuclear neutrophils in aggressive periodontitis. Conclusion:, High serum IgG levels against P. gingivalis and A. actinomycetemcomitans promote phagocytosis in periodontitis. The extracellular release of reactive oxygen species and neutrophil elastase by polymorphonuclear neutrophils may also contribute to damage of the surrounding periodontal tissues. [source] Comparative analysis of putative periodontopathic bacteria by multiplex polymerase chain reactionJOURNAL OF PERIODONTAL RESEARCH, Issue 3 2008M. Morikawa Background and Objective:, The polymerase chain reaction (PCR) has been applied for the rapid and specific detection of periodontopathic bacteria in subgingival plaque and is potentially of clinical benefit in the diagnosis and treatment of periodontitis subjects. However, several technical points need to be modified before the conventional PCR detection system can be used by clinicians. Material and Methods:, To develop a PCR-based technique more applicable for clinical use than conventional PCR, we established a multiplex PCR for five putative periodontopathic (Treponema denticola, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia and Tannerella forsythia) and two nonperiodontopathic (Streptococcus sanguinis and Streptococcus salivarius) species of bacteria using whole-plaque suspension as templates, and detected bacteria in subgingival plaque taken from 85 subjects at the supportive periodontal therapy stage after active periodontal treatments. Results:, Among putative periodontopathic bacteria, the detection frequency of T. denticola and P. gingivalis was elevated in parallel with higher probing pocket depth and clinical attachment loss, and had 4.2,14.1 times increasing odds of the clinical parameters tested. Detection of any of the five species of putative periodontopathic bacteria markedly increased the odds ratio of a higher probing pocket depth, clinical attachment loss and bleeding on probing. Conclusion:, The multiplex PCR system developed in this study enabled the detection of all the bacteria under investigation in one reaction tube in a less time- and labor-intensive manner than conventional PCR. These results support the potential clinical use of multiplex PCR for detecting periodontopathic bacteria and for evaluating therapeutic strategies and predicting the prognosis for each subject. [source] Quantitative analysis of association between herpesviruses and bacterial pathogens in periodontitisJOURNAL OF PERIODONTAL RESEARCH, Issue 3 2008I. Saygun Background and Objective:, The development of human periodontitis may depend upon cooperative interactions among herpesviruses, specific pathogenic bacteria and tissue-destructive inflammatory mediators. This study sought to identify associations among human cytomegalovirus, Epstein,Barr virus and six putative periodontopathic bacteria in periodontitis lesions. Material and Methods:, Fifteen periodontitis patients (nine with aggressive periodontitis and six with chronic periodontitis) and 15 periodontally normal subjects were included in the study. In each study subject, a microbiological sample was collected, using a curette, from the deepest periodontal probing depth of the dentition. A real-time TaqMan® polymerase chain reaction assay was employed to determine the subgingival counts of human cytomegalovirus, Epstein,Barr virus, Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and Campylobacter rectus. Statistical analysis was performed using the Student's t -test, the Pearson correlation coefficient test and the single variable logistic regression test for odds ratio-based risk calculation. Results:, Human cytomegalovirus was detected in eight periodontitis lesions and in one normal periodontal site, Epstein,Barr virus was detected in nine periodontitis lesions and in two normal periodontal sites, and the study bacteria were detected in 6,15 periodontitis lesions and in 1,11 normal periodontal sites. Correlations were found between counts of human cytomegalovirus and Epstein,Barr virus, between counts of human cytomegalovirus and P. gingivalis, T. forsythia and C. rectus, and between counts of Epstein,Barr virus and P. gingivalis and T. forsythia. Human cytomegalovirus and Epstein,Barr virus counts were also positively associated with the level of periodontal attachment loss, probing pocket depth and gingival bleeding on probing. Conclusion:, This study confirmed that periodontal human cytomegalovirus and Epstein,Barr virus are associated with major periodontopathic bacteria and with the severity of periodontal disease. The finding of abundant herpesviruses in periodontitis lesions redefines the pathogenic paradigm of the disease. Understanding the interplay between herpesviruses and specific bacterial species in the pathogenesis of periodontitis may form the basis for new approaches to preventing, reducing or delaying tissue breakdown from periodontal infections. [source] Biofilms in the Edentulous Oral CavityJOURNAL OF PROSTHODONTICS, Issue 5 2008Amit Sachdeo BDS, DMSc Abstract Purpose: The oral cavity presents numerous surfaces for microbial colonization. These surfaces produce biofilms of differing complexities unique to each individual. Several studies have looked at biofilms in dentate patients. There has been limited research regarding biofilms on dentures or soft tissues of edentulous patients. The purpose of the present investigation was to provide meaningful data describing microbial ecological relationships in the oral cavity of edentulous patients and to evaluate the microbiota on hard and soft tissue surfaces and saliva in edentulous patients wearing complete dentures. Materials and Methods: Sixty-one edentulous subjects with complete maxillary and mandibular dentures were recruited. "Supragingival" biofilm samples were taken from 28 denture teeth for each subject. Biofilm samples were also taken from the dorsal, lateral, and ventral surfaces of the tongue, floor of mouth, buccal mucosa, hard palate, vestibule/lip, "attached gingiva," and saliva. Samples were individually analyzed for their content of 41 bacterial species using checkerboard DNA,DNA hybridization. Levels and proportions of each species were determined for every sample location. Results: Periodontal pathogens such as Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were clearly present in the samples from the edentulous subjects. Microbial profiles in samples from the soft tissue surfaces differed among site locations. Samples from the dorsum of the tongue exhibited the highest bacterial counts followed by the "attached gingiva" and the lateral surfaces of the tongue, while the lowest mean counts were found in samples from the buccal mucosa and labial vestibules. Using cluster analysis of the proportions of the test species, three clusters were formed. The first cluster comprised saliva, supragingival plaque, and the lateral and dorsal surfaces of the tongue. The second cluster comprised the other six soft tissue surfaces. Species on the denture palate formed a third cluster. Conclusions: One of the major findings in this study was the detection of periodontal pathogens, A. actinomycetemcomitans and P. gingivalis, in the edentulous subjects, as these species were thought to disappear after removal of all natural teeth. This finding has implications regarding future dental treatment and the general health of individuals. Distinct patterns of microbial colonization were seen on the different soft tissue surfaces. Thus, this investigation provided the first step in defining the organisms that are associated with edentulous patients on both soft (mucosa) and hard surfaces (denture). The study also provided meaningful data that described microbial ecological relationships in the oral cavity of edentulous subjects. The authors believe that this study is the first comprehensive assessment of the microbiota in the complete denture-wearing subject. [source] Elevated platelet and leukocyte response to oral bacteria in periodontitisJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 1 2009E. A. NICU Summary.,Background:,Periodontitis is associated with an increased risk for cardiovascular diseases (CVD), but the underlying mechanisms are poorly understood. Recently, we showed that platelets from periodontitis patients are more activated than those from controls. Objective:,Given the regularly occurring bacteremic episodes in periodontitis patients, we hypothesized that platelets and/or leukocytes from periodontitis patients are more sensitive to stimulation by oral bacteria, in particular the known periodontal pathogens, than platelets from control subjects. Methods:,Three-color flow cytometry analysis was performed to quantify activation of platelets (P-selectin, PAC-1, CD63) and leukocytes (CD11b) in whole blood from patients with periodontitis (n = 19) and controls (n = 18), with and without stimulation by oral bacteria. Phagocytosis was assessed by using green-fluorescent protein (GFP)-expressing Aggregatibacter actinomycetemcomitans (Aa). Results:,Neutrophils and monocytes were activated by all species of oral bacteria tested, but no differences were observed between patients and controls. In response to several species of oral bacteria, platelets from periodontitis patients showed, compared with controls, increased exposure of P-selectin (P = 0.027) and increased formation of platelet-monocyte complexes (P = 0.040). Platelet-leukocyte complexes bound and/or phagocytosed more GFP- Aa than platelet-free leukocytes (for neutrophils and monocytes, in both patients and controls, P < 0.001). Conclusions:,In periodontitis, increased platelet response to oral bacteria is paralleled by increased formation of platelet-leukocyte complexes with elevated capacity for bacterial clearance. We speculate that activated platelets and leukocytes might contribute to increased atherothrombotic activity. [source] Characterization of a new serotype g isolate of Aggregatibacter actinomycetemcomitansMOLECULAR ORAL MICROBIOLOGY, Issue 3 2010K. Takada Summary Aggregatibacter actinomycetemcomitans is usually isolated from the oral cavity where it is associated with active periodontitis. The species can be divided into six serotypes (a,f) according to their surface carbohydrate antigens. However, some clinical isolates cannot be grouped within these six serotypes. Gram-negative, facultative anaerobic, catalase-positive coccobacilli were isolated from a patient with periodontitis and identified by employing genetic, biochemical and serological analyses. Phenotypic data identified the isolate as A. actinomycetemcomitans. Serotype-specific polysaccharide antigen from the isolate was untypeable by immunodiffusion testing in comparison with reference A. actinomycetemcomitans serotype a to f strains. Biofilm formation by the isolate was strong but cytotoxic activity was low. Gas chromatography/mass spectroscopy analysis of partially methylated alditol acetates from surface polysaccharide showed the presence of 2,4-di- O -methyl-rhamnose and 2,3,6-tri- O -methyl-glucose, with a 1 : 1 m ratio. The 1H- and 13C-nuclear magnetic resonance spectra of the antigen showed that both constituent glycoses had ,-anomeric configuration. It is proposed that the untyped strain is a new A. actinomycetemcomitans serotype, designated serotype g. [source] Expression of receptor activator of nuclear factor-,B ligand by B cells in response to oral bacteriaMOLECULAR ORAL MICROBIOLOGY, Issue 3 2009X. Han Introduction:, We investigated receptor activator of nuclear factor-,B ligand (RANKL) expression by B lymphocytes during early and late aspects of the immune response to Aggregatibacter actinomycetemcomitans, a gram-negative, anaerobic bacterium associated with aggressive periodontal disease. Methods:, Expression of messenger RNA transcripts (tumor necrosis factor-,, Toll-like receptors 4 and 9, interleukins 4 and 10, and RANKL) involved in early (1-day) and late (10-day) responses in cultured rat splenocytes was examined by reverse transcription,polymerase chain reaction (RT-PCR). The immune cell distribution (T, B, and natural killer cells and macrophages) in cultured rat splenocytes and RANKL expression in B cells were determined by flow cytometric analyses. B-cell capacity for induction of osteoclast differentiation was evaluated by coculture with RAW 264.7 cells followed by a tartrate-resistant acid phosphatase (TRAP) activity assay. Results:, The expression levels of interleukins 4 and 10 in cultured cells were not changed in the presence of A. actinomycetemcomitans until cultured for 3 days, and peaked after 7 days. After culture for 10 days, the percentages of B and T cells, the overall RANKL messenger RNA transcripts, and the percentage of RANKL-expressing immunoglobulin G-positive cells were significantly increased in the presence of A. actinomycetemcomitans. These increases were considerably greater in cells isolated from A. actinomycetemcomitans -immunized animals than from non-immunized animals. RAW 264.7 cells demonstrated significantly increased TRAP activity when cocultured with B cells from A. actinomycetemcomitans -immunized animals. The addition of human osteoprotegerin-Fc to the culture significantly diminished such increases. Conclusion:, This study suggests that B-lymphocyte involvement in the immune response to A. actinomycetemcomitans through upregulation of RANKL expression potentially contribute to bone resorption in periodontal disease. [source] Differential effects of five Aggregatibacter actinomycetemcomitans strains on gingival epithelial cellsMOLECULAR ORAL MICROBIOLOGY, Issue 6 2008T. Shimada Introduction:, We investigated gingival epithelial cell proliferation and expression of interleukin-8 (IL-8) and intercellular adhesion molecule 1 (ICAM-1) in response to Aggregatibacter actinomycetemcomitans serotypes a, b, and c. Methods:, Human gingival cells (Ca9-22) were cultured in bacterial extracts prepared from five strains of A. actinomycetemcomitans: ATCC 43717 (serotype a); ATCC 29524, ATCC 29522, and ATCC 43718 (all serotype b); and ATCC 43719 (serotype c). Results:, In bacterial extracts of ATCC 29522, cell growth was significantly impaired, while the expression of IL-8 and ICAM-1 was significantly increased. The level of induction in response to the other strains was minimal. Conclusion:, Our results indicate that the five strains of A. actinomycetemcomitans have distinct effects on the abilities of human gingival epithelial cells to proliferate and to produce proinflammatory factors. [source] Inhibition of interferon-,-induced nitric oxide production in endotoxin-activated macrophages by cytolethal distending toxinMOLECULAR ORAL MICROBIOLOGY, Issue 5 2008K. P. S. Fernandes Introduction:, Cytolethal distending toxin (CDT) is a DNA-targeting agent produced by certain pathogenic gram-negative bacteria such as the periodontopathogenic organism Aggregatibacter actinomycetemcomitans. CDT targets lymphocytes and other cells causing cell cycle arrest and apoptosis, impairing the host immune response and contributing to the persistence of infections caused by this microorganism. In this study we explored the effects of CDT on the innate immune response, by investigating how it affects production of nitric oxide (NO) by macrophages. Methods:, Murine peritoneal macrophages were stimulated with Escherichia coli sonicates and NO production was measured in the presence or not of active CDT. Results:, We observed that CDT promptly and significantly inhibited NO production by inducible nitric oxide synthase (iNOS) in a dose-dependent manner. This inhibition is directed towards interferon-,-dependent pathways and is not mediated by either interleukin-4 or interleukin-10. Conclusion:, This mechanism may constitute an important aspect of the immunosuppression mediated by CDT and may have potential clinical implications in A. actinomycetemcomitans infections. [source] Regulation of type I plasminogen activator inhibitor in human gingival fibroblasts with cyclosporine AORAL DISEASES, Issue 4 2010Y-C Ho Oral Diseases (2010) 16, 396,401 Objectives:, Cyclosporine A (CsA) is used as an immunosuppressive agent and its prominent side effect is the induction of gingival overgrowth. Type I plasminogen activator inhibitor (PAI-1) has shown to play an important role in CsA-induced gingival overgrowth. However, little is known about whether factors can modulate CsA-induced PAI-1 expression. Methods:, Cytotoxicity, reverse transcriptase-polymerase chain reaction, and enzyme-linked immunosorbent assay were used to investigate the effects of Human gingival fibroblasts (HGFs) exposed to CsA. In addition, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, interlukin-1,, tumor necrosis factor-,, mitogen-activated protein kinase kinase (MEK) inhibitor U0126, signal-regulated protein kinase (ERK) inhibitor PD98059 and cell-permeable glutathione precursor N -acetyl- L -cysteine (NAC) were added to test how they modulated the effects of CsA-induced PAI-1 expression. Results:, The concentration of CsA higher than 500 ng ml,1 demonstrated cytotoxicity to HGFs (P < 0.05). Periodontal pathogens as well as proinflammatory cytokines were found to increase the CsA-induced PAI-1 mRNA and protein expression (P < 0.05). Pharmacological agents NAC, U0126, and PD98059 were found to decrease the CsA-induced PAI-1 mRNA and protein expression (P < 0.05). Conclusions:, Cyclosporine A (CsA) may predispose to gingival overgrowth under inflammatory environments. The regulation of PAI-1 expression induced by CsA might be critically related with the intracellular glutathione and the ERK-MAPK pathway. [source] The G1 cell cycle arrest of macrophages infected with Aggregatibacter actinomycetemcomitansORAL DISEASES, Issue 3 2010H Kasai Oral Diseases (2010) 16, 305,309 Objectives:, Infection of murine macrophage cell line J774.1 with the periodontopathic bacterium Aggregatibacter actinomycetemcomitans induces apoptotic cell death. The infection induces cell cycle arrest in the G1 phase prior to the appearance of apoptotic cells. This study determined the involvement of various cell cycle-related signal molecules in A. actinomycetemcomitans-induced G1 cell cycle arrest. Materials and Methods:, Cell cycle in J774.1 cells infected with A. actinomycetemcomitans was analyzed with a flow cytometer. Immunoblot analysis was also employed to determine the expression levels of intracellular signal molecules. Results:, Flow cytometric analysis revealed that the percentage of cells in the G1 phase increased to 77.2% at 12 h after A. actinomycetemcomitans infection. Additionally, according to immunoblot analysis, expression levels of hyperphosphorylated forms of retinoblastoma protein (ppRb) declined in J774.1 cells following A. actinomycetemcomitans infection, whereas hypophosphorylated Rb (pRb) expression levels were elevated slightly. Expression levels of cyclin D1 and D2 in the cells decreased gradually postinfection; CDK2, CDK4, CDK6 and cyclin E levels were not changed. Furthermore, postinfection, p21CIP1/WAF1 expression increased at 6 h, followed by a subsequent decrease. Conclusion:, These findings suggest that cyclin D1 and D2 and p21CIP1/WAF1 participate in G1 cell cycle arrest in A. actinomycetemcomitans-infected J774.1 cells. [source] The highly leukotoxic JP2 clone of Aggregatibacter actinomycetemcomitans: evolutionary aspects, epidemiology and etiological role in aggressive periodontitisAPMIS, Issue 2010DORTE HAUBEK No abstract is available for this article. [source] Two-Year Outcome with Nobel Direct® Implants: A Retrospective Radiographic and Microbiologic Study in 10 PatientsCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 3 2009Tommie Van de Velde LA ABSTRACT Introduction: The Nobel Direct® implant (Nobel Biocare AB, Göteborg, Sweden) was developed to minimize marginal bone resorption and to result in "soft tissue integration" for an optimized aesthetic outcome. However, conflicting results have been presented in the literature. The aim of this present study was to evaluate the clinical and microbiologic outcomes of Nobel Direct implants. Materials and Methods: Ten partially edentulous subjects without evidence of active periodontitis (mean age 55 years) received 12 Nobel Direct implants. Implants were loaded with single crowns after a healing period of 3 to 6 months. Treatment outcomes were assessed at month 24. Routine clinical assessments, intraoral radiographs, and microbiologic samplings were made. Histologic analysis of one failing implant and chemical spectroscopy around three unused implants was performed. Paired Wilcoxon signed-rank test was used for the evaluation of bone loss; otherwise, descriptive analysis was performed. Results: Implants were functionally loaded after 3 to 6 months. At 2 years, the mean bone loss of remaining implants was 2.0 mm (SD ± 1.1 mm; range: 0.0,3.4 mm). Three out of 12 implants with an early mean bone loss >3 mm were lost. The surviving implants showed increasing bone loss between 6 and 24 months (p = .028). Only 3 out of the 12 implants were considered successful and showed bone loss of <1.7 mm after 2 years. High rates of pathogens, including Aggregatibacter actinomycetemcomitans, Fusobacterium spp., Porphyromonas gingivalis, Pseudomonas aeruginosa, and Tanerella forsythia, were found. Chemical spectroscopy revealed, despite the normal signals from Ti, O, and C, also peaks of P, F, S, N, and Ca. A normal histologic image of osseointegration was observed in the apical part of the retrieved implant. Conclusion: Radiographic evidence and 25% implant failures are indications of a low success rate. High counts and prevalence of significant pathogens were found at surviving implants. Although extensive bone loss had occurred in the coronal part, the apical portion of the implant showed some bone to implant integration. [source] | ||||||||||