M P A Mayer

University of São Paulo, San Paulo, São Paulo, Brazil

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Publications (56)76.1 Total impact

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    ABSTRACT: Periodontal disease (PD) is induced by a complex microbiota, such as Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola (together called the red complex), which triggers intense inflammatory reaction. Down syndrome (DS) individuals demonstrate a high prevalence of PD compared with those who are otherwise chromosomally normal (euploids). This pilot study aimed to evaluate the effect of non-surgical periodontal treatment in DS chronic periodontitis patients on clinical and microbiological parameters. Patients with chronic periodontitis, 23 DS and 12 euploids (control group), were submitted to non-surgical mechanical periodontal treatment, followed by maintenance for 45 days. Clinical parameters after periodontal treatment were similar in diseased and healthy sites, independent of the genetic background. Diseased sites of DS and control patients harbored similar levels of P. gingivalis and T. forsythia at baseline, but significantly higher levels of T. denticola were found in DS patients. Increased levels of P. gingivalis at healthy sites were found in DS individuals. Non-surgical periodontal therapy decreased the levels of red complex microorganisms and improved the tested clinical parameters of diseased sites in both groups. However, the levels of red complex bacteria were higher in diseased sites of DS patients after the periodontal treatment. We conclude in this pilot study that, although the mechanical periodontal treatment seemed to be effective in DS subjects over a short-term period, the red complex bacteria levels did not decrease significantly in diseased sites, as occurred in controls. Therefore, for DS patients, it seems that the conventional non-surgical periodontal therapy should be improved by utilizing adjuvants to reduce the presence of periodontopathogens.
    11/2014;
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    ABSTRACT: Objective: To establish an animal model to study the host immune response to Aggregatebacter actinomycetemcomitans (Aa) biofilm. Method: Titanium implant abutments were micro textured and acid-etched to facilitate biofilm formation on the surface. The abutments were inoculated in vitro with Aa D7S-1 (WT) and a double knockout mutant (DM) of omp29 and its paralogue. Sham-inoculated abutments served as negative control. Sterile titanium implants were transmucosally inserted into rat maxillary alveolar ridge with the abutments (N=15 for each of WT, DM and sham-inoculated groups). The animals were evaluated clinically up to 6 weeks. Micro-CT imaging was performed at 3 and 6 weeks. The levels of Aa on the abutments were determined by quantitative PCR. Result: Presurgically, the amount of biofilm was on average 9.9×106± 4.9×106 of WT cells/abutment and 2.2×107±8.4×106 DM cells/abutment. After the surgery, bleeding, ulceration, hyperplasia, and necrosis were observed around biofilm-inoculated titanium abutments. By 3 weeks 8/15, 6/15 and 6/15 implants remained stable in WT, DM and sham-inoculated implants, respectively. By 6 weeks 3/15, 5/15 and 5/15 implants remained stable in WT, DM and sham-inoculated implants, respectively. After 6 weeks, the persistence of Aa on the abutment was as followed: 22% of WT and <1% DM. Bone loss was noted in bone surrounding implants inoculated with bacteria but not in shame-inoculated implants. Conclusion: A novel animal model where Aa biofilm was established in vitro on titanium implant abutments prior to installation in rat oral cavity, leading to an inflammatory response, osteolysis, and tissue destruction. This model could be used to investigate host responses to biofilm and anti-biofilm treatment strategies.
    2014 IADR/PER Congress; 09/2014
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    ABSTRACT: Objective: to elucidate the mechanisms involved in the anti-inflammatory properties of Brazilian red propolis Method: different concentrations of ethanolic extract of Brazilian red propolis (EEBRP) were added to RAW 264.7 macrophages after activation with LPS, and NO production and cell viability determined. Production of TNF-α, IL1β, TGF-β, IL-4, IL-6, IL-10, IL-12, GM-CSF, IFN-Ɣ and expression of genes related to cytokines production and nitric oxide , PI3K-AKT and signal transduction pathway were evaluated by ELISA and RT-qPCR, respectively. Differences were determined by one-way ANOVA followed by Tukey-Kramer Result: EEBRP inhibited NO production by 69% without affecting cell viability at the concentration of 50 µg/ml when compared with control cells (treated with vehicle) (p<0.05). Levels of IL-12, GM-CSF, IFN-Ɣ, IL-1β, IL-4, IL-10 and TGF-β in cell supernatant were reduced and of TNF- α and IL-6 increased with the addition of EEBRP (p<0.05). EEBRP induced alteration in expression of 57 genes. Genes involved in Toll-like response; oxide nitric sintetase production (all types), Nf-KB and MAPK signaling pathways such as Tirap, Pdk1, Pak1, Nfkb1, Mtcp1, Gsk3b, Fos, Elk1, Il1β, Il1f9 were negatively regulated by EEBRP(fold-change rate > 5; p<0.05) Conclusion: EEBRP presents antiinflammatory properties by altering signaling pathways leading to reduction in production of pro-inflammatory factors.
    2014 IADR/PER Congress; 09/2014
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    ABSTRACT: Objective: Aggregatibacter actinomycetemcomitans is associated to the etiology of aggressive periodontitis and produces the cytolethal distending toxin (AaCDT). Since CDT affects monocytic cells, we aimed to evaluate the effect of AaCDT on gene expression of pre-osteoclastic cells. Method: Monocytes obtained from murinic bone marrow (BMC) were submitted to different concentrations of recombinant AaCDT in the presence and absence of RANKL. After 6 days, viability was determined (MTT) and TRAP + cells presenting > 3 nuclei were counted. After 2-6 days, RT-qPCR was performed to evaluate expression of genes associated with osteoclastogenesis (rank, ctpk, nfatc1 and irf-8) and gapdhwas used as control. The data were analyzed by ANOVA followed by Tukey or Bonferroni tests (p < 0.05). Result: At the tested concentrations, CDT did not affect cells viability, but the number of TRAP+ multinucleated cells increased with increasing AaCDT concentrations, in the presence or absence of RANKL. The expression of rank was down regulated after 4 days of incubation in AaCDT-treated cells in the absence of RANKL. This effect was also seen in BMC added with RANKL after 2-6 days. Furthermore, after 4 and 6 days, AaCDT down regulated the expression of transcription factor nfatc1 and ctpK (encoding cathepsin K). Thus, although an increase in TRAP+ cells was observed in AaCDT treated pre-osteoclastic cells, genes involved in osteoclastogenesis were repressed by the toxin, even in presence of RANKL. Conclusion: AaCDT may affect osteoclastogenesis by inhibiting signaling in pre-osteoclastic cells, and by down regulating the expression of genes associated with mature osteoclasts.
    2014 IADR/PER Congress; 09/2014
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    ABSTRACT: Objective: recent data have shown that Brazilian red propolis presents immunemodulatory properties, which led us to elucidate the mechanisms involved in the anti-inflammatory properties of one of its components, Neovestitol Method: neovestitol was obtained from ethanolic extract of Brazilian red propolis after bio-guided fractionation coupled with GC-MS analysis. Different concentrations of Neovestitol were added to RAW 264.7 macrophages after activation with LPS. After 48 hours, NO production and cell viability were determined. Production of TNF-α, IL1β, TGF-β, IL-4, IL-6, IL-10, IL-12, GM-CSF, IFN-Ɣ and expression of genes related to cytokines production, nitric oxide , PI3K-AKT and signal transduction pathways were evaluated by ELISA and RT-qPCR, respectively. Differences were determined by one-way ANOVA followed by Tukey-Kramer Result: Neovestitol inhibited NO production by 63% without affecting cell viability at the concentration of 60 µg/ml when compared with control cells (treated with vehicle) (p<0.05). Levels of GM-CSF, IFN- Ɣ, IL-1 β, IL-4, TNF- α and IL-6 in cell supernatant were reduced and of IL-10 increased with the addition of neovestitol (p<0.05). Neovestitol induced alteration in the expression of 43 genes. Genes involved in Toll-like response; nitric oxide sintetase production (all types), Nf-KB and Il-1 signaling pathways such as Bad, Chuk, Elk1, Ifnb1, Il1b, Lif, Calm1, Capns1, Egr1, Nox1, Scd2 and Scd3 were negatively regulated by neovestitol (fold-change rate > 5; p<0.05). Furthermore, its role in inhibition of leukocyte transmigration was suggested by inhibition of expression of Nox1 and in the regulation of fatty acid associated genes such as Scd2 e Scd3 Conclusion: Neovestitol may represent a new antiinflammatory agent by inhibiting signaling pathways and consequently reducing the production of pro-inflammatory factors and by interfering in leukocyte transmigration
    2014 IADR/PER Congress; 09/2014
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    ABSTRACT: AimsTo evaluate the association among serum immunoglobulin G (IgG) responses to Aggregatibacter actinomycetemcomitans (Aa) serotypes a, b and c, Porphyromonas gingivalis (Pg) Tannerella forsythia (Tf) and clinical parameters in Aggressive Periodontitis (AP) subjects. Associations between periodontal pathogens and clinical and immunological parameters were also evaluated.Methods38 subjects diagnosed with generalized AP (GAP) and localized AP (LAP) were included. Ten healthy controls were also evaluated. Clinical parameters were assessed and percentages of subgingival levels of Aa, Pg and Tf, (beyond bacterial load), were determined by quantitative real-time polymerase chain reaction. Serum IgG antibody levels against Aa, Pg and Tf were evaluated by enzyme-linked immunosorbent assay.ResultsPercentages of Aa, Pg and Tf were significantly higher in AP than in controls. The response to Aa serotype c was higher in LAP subjects than in controls. There were no differences in microbial composition or antibodies responses between GAP and LAP, except for IgG response to Tf. Pg levels were correlated with PD, BoP and CAL in GAP but not in LAP subjects. Tf levels correlated to PD and CAL in GAP subjects. In GAP, the infection levels of Aa and Pg correlated with the corresponding IgG levels to Aa serotype c and Pg.Conclusion Given the evidences that IgG response in AP patients correlated with bacterial infection level in GAP, but not in LAP, and that LAP patients lack a response to Tf, despite harboring this species, our data suggests a difference in host immune defense between these two forms of aggressive periodontitis.This article is protected by copyright. All rights reserved.
    Journal Of Clinical Periodontology 07/2014; · 3.69 Impact Factor
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    ABSTRACT: Objectives: the role of periodontitis in systemic inflammation in type 2 diabetes mellitus (T2DM) is still not fully elucidated. This study aimed to evaluate serum levels of a cytokines panel in patients with T2DM and moderate to severe chronic periodontitis and to compare with their controls. Methods: 50 patients older than 40 years and with BMI < 40 were enrolled in this study. Periodontal condition and glycated haemoglobin levels (HbA1c) were evaluated. Five groups were analyzed: DMI+P: periodontitis, poor controlled T2DM (HbA1c ≥ 8.0%); DMA+P: periodontitis, well controlled T2DM (HbA1c < 8.0%), P: non-diabetic with periodontitis, D group: diabetic without periodontitis and H group: non-diabetic without periodontitis. Cytokines sera levels were determined with the Bio Plex Pro Human Cytokine GrpI Panel 17. Periodontal clinical data were analyzed by statistical software (SPSS Inc., USA) and cytokines data were analyzed by non-parametric statistical methods Kruskall-Wallis and Dunns. Results were considered statistically significant at p < 0.05. Results: Mean ± standard deviation of HbA1c (%) of each group was: H: 5.22±0.48; P: 5.47±0.57; D: 7.43±0.82; DMA+P: 6.74±0.74 and DMI+P: 10.55±2.28. IL-2, IL-4, IL-17 and IFN-δ were not detected in most sera samples. There were no statistical differences among groups for IL-8, IL-12, IL-13 and MIP-1β. H group presented lower levels of IL-1β, IL-5, IL-10, MCP-1 and higher GM-CSF levels than the others groups. TNF-α was elevated in all periodontitis groups (DMI+P, DMA+P and P) independently on the presence of diabetes (D and H), whereas IL-6 and G-CSF were significantly higher only in DMI+P when compared to H. D group was characterized by higher values of IL-7 when compared to H group. Conclusion: The data indicates that periodontitis increases systemic inflammatory markers in no diabetes and diabetic patients. However the latter, particularly those with poor-glycemic control there is a more pronounced inflammatory response.
    IADR General Session and Exhibition 2014; 06/2014
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    ABSTRACT: Periodontitis is an inflammatory disease that results from an interaction between dental biofilm agents and the host immune-inflammatory response. Periodontopathogenic organisms, such as Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, as well as the host's susceptibility, represented by the host's genetic makeup, are the key factors that influence this complex disease. Recently, we identified haplotypes in the IL4 gene that were associated with chronic periodontitis (CP). This study aimed to evaluate whether subjects with different IL4 haplotypes (TCI/CCI and TTD/CTI) would be differentially colonized by periodontopathogens and whether they would respond differently to non-surgical periodontal therapy. Thirty-nine patients carrying the IL4 haplotype of genetic susceptibility to CP (IL4+) or protection against CP (IL4-) were evaluated. Those groups were further subdivided into individuals with CP (CP IL4+ or CP IL4-) and those that were periodontally healthy (H) (H IL4+ or H IL4-). CP patients were submitted to non-surgical periodontal therapy. Clinical and microbiological analyses were performed considering the data at baseline and 45 and 90 days after periodontal therapy. Periodontopathogens levels were evaluated by absolute quantitative polymerase chain reaction (qPCR). The baseline data revealed that the total levels of periodontopathogens were higher in the CP IL4+ than in the CP IL4- groups. Clinical analyses revealed that the periodontal therapy was equally effective, independent of the subject's IL4 genetic load. The TCI/CCI IL4 haplotype, previously associated with genetic susceptibility to CP, was also associated with increased levels of periodontopathogenic bacteria, but this genetic background did not influence the response to non-surgical periodontal treatment.
    European Journal of Clinical Microbiology 06/2013; · 3.02 Impact Factor
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    ABSTRACT: Chronic periodontitis (CP) is considered to be a multifactorial disease influenced by microbial and genetic factors. The aim of the present study was to investigate whether the genetic susceptibility to CP in individuals with the IL8 ATC/TTC haplotype is associated with subgingival levels of periodontopathogens. Sixty-five individuals, grouped according to the presence (n = 28) or absence (n = 37) of the IL8 haplotype, were evaluated. After clinical periodontal evaluation, each group was subdivided according to the presence (CP) or absence (H) of periodontitis. Four subgingival samples were obtained from CP and two samples per subject from H patients. The levels and proportions of Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola were analyzed using quantitative real-time polymerase chain reaction (q-PCR). No differences were found in the proportion of periodontopathogenic bacteria between groups with the presence or absence of the IL8 haplotype. However, in the CP groups, the levels of periodontopathogens were significantly higher in the individuals without the IL8 haplotype than in the individuals with the IL8 haplotype. These results suggest that periodontal destruction may occur in patients who are considered to be genetically susceptible to CP with a lower microbial challenge because of the presence of the IL8 ATC/TTC haplotype than in patients without this haplotype.
    European Journal of Clinical Microbiology 05/2013; · 3.02 Impact Factor
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    ABSTRACT: BACKGROUND AND OBJECTIVE: Periodontopathogens experience several challenges in the oral cavity that may influence their transcription profile and resulting phenotype. This study evaluated the effect of environmental changes on phenotype and gene expression in a serotype b Aggregatibacter actinomycetemcomitans isolate. MATERIAL AND METHODS: Cultures in early exponential phase and at the start of stationary growth phase in microaerophilic and anaerobic atmospheres were evaluated. Cell hydrophobic properties were measured by adherence to n-hexadecane; in addition, adhesion to, and the ability to invade, KB cells was evaluated. Relative transcription of 12 virulence-associated genes was determined by real-time reverse transcritption quantitative PCR. RESULTS: The culture conditions tested in this study were found to influence the phenotypic and genotypic traits of A. actinomycetemcomitans. Cells cultured in microaerophilic conditions were the most hydrophobic, reached the highest adhesion efficiency and showed up-regulation of omp100 (which encodes an adhesion) and pga (related to polysaccharide synthesis). Cells grown anaerobically were more invasive to epithelial cells and showed up-regulation of genes involved in host-cell invasion or apoptosis induction (such as apaH, omp29, cagE and cdtB) and in adhesion to extracellular matrix protein (emaA). CONCLUSION: Environmental conditions of different oral habitats may influence the expression of factors involved in the binding of A. actinomycetemcomitans to host tissues and the damage resulting thereby, and thus should be considered in in-vitro studies assessing its pathogenic potential.
    Journal of Periodontal Research 04/2013; · 1.99 Impact Factor
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    ABSTRACT: Cytolethal distending toxin (CDT) is produced by the periodontopathogen Aggregatibacter actinomycetemcomitans and other mucosa associated pathogenic agents. CDT may be involved in the perpetuation of the chronic infections, but its mechanisms of host defense modulation are not fully understood. Objectives: to evaluate the effect of Cdt on macrophage phagocytosis, cytokines and nitric oxide (NO) production. Methods: LPS activated and non activated Raw 264.7 macrophages were cultivated with purified-recombinant Cdt (rCdt) for 48 hours. Bioparticles of fluorescent E. coli were used in a phagocytosis assay, and data reported by fluorescence measurements. The effects of rCdtABC on cell viability, NO production, cell proliferation, cell cycle and cytokines profile were also evaluated. Results: The phagocytosis of bioparticles decreased with increased concentration of rCdt. Production of NO, IL-1β and TNF-α was modulated by Cdt, but not IL-10 or IL-12.The addition of rCdt to LPS activated macrophages resulted in IL-10 upregulation but did not interfere with other cytokines, NO production and phagocythic activity. Conclusions: these data indicated that CDT may play a key role in periodontal disease, caused by A. actinomycetemcomitans by modulating macrophages phagocythic activity and cytokines production.
    PER/IADR Congress 2012; 09/2012
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    ABSTRACT: Aggregatibacter actnimomycetemcomitans is a periodontal pathogen belonging to the HACEK group. Its adhesin Aae mediates adherence to epithelial and endothelial cells. Objectives: to test the hypothesis that Aae is able to bind to extracellular matrix (ECM) proteins, similar to other autotransporter proteins involved with adhesion. Methods: The gene aae of A. actinomycetemcomitans HK 1651 was cloned in pET-28 b (+), and expressed in E. coli. Recombinant AaeHis was purified and tested for its ability to bind to laminin and fibronectin. ECM proteins coated 96 well plates were incubated with different concentrations of purified AaeHis. Albumin coated wells and a nonbinding his-tagged protein were used as negative controls. After washings, the binding of AaeHis was detected by ELISA, using mouse anti-polyHistidine Ab and goat anti mouse IgG peroxidase Ab conjugate. Nonlinear regression analysis of the ELISA data was used to estimate the binding interactions between purified Aae and each of the ECM proteins. Results: Purified Aae bound to laminin and fibronectin in a dose dependent manner, but not the negative control albumin (ANOVA, Tukey, p<0.001). Conclusions: interaction between ECM and Aae suggested that this adhesin is important for the colonization of A.actinomycetemcomitans in inflamed subgingival sites where the organism encounter damaged epithelium and exposed basement membrane. (FAPESP 09/54178-0, 09/54849 ; CAPES).
    PER/IADR Congress 2012; 09/2012
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    ABSTRACT: Chronic inflammation has been recognized as the underlying factor in the development of type 2 diabetes. The persistent stimuli promoted by subgingival bacteria result in release of several proinflammatory mediators, such as the chemotatic chemokines CXCL8/IL-8 and monocyte chemoattractant protein, MCP-1/CCL2. MCP-1 binding to CCR2 does not only result in its well-established chemotactic function but also plays a role in other process such as obesity-induced diabetes. Objectives: This study aimed to evaluate the impact of periodontitis on the levels of systemic inflammatory biomarkers IL-8 and MCP-1 and glycemic control in type 2 diabetes patients. Methods: After periodontal clinical evaluation, 18 type 2 diabetic patients were evaluated for glycemic status by serum levels of Hba1c, and serum MCP-1 and IL-8 levels by ELISA. Data were analyzed by ANOVA –Tukey and spearman rank correlation. Results: 7 patients were considered periodontaly healthy (H) and 11 presented chronic periodontitis (CP). The HbA1c levels ranged from 6.6 to 8.3% in H and from 6.5 to 12.6% in CP. Mean IL-8 sera levels were 1.71ng/ml ± 0.75 in H and 2.26ng/ml ± 0.81 in CP. HbA1c and IL-8 levels did not correlate with any of the studied variables. However, mean MCP-1 levels were significantly higher in H (130.8ng/ml ± 20.66) than in CP (91.58ng/ml ± 7.42) (Tukey, p<0.001). Furthermore, MCP-1 sera levels were inversely correlated with the number of periodontal sites with pocket depth 4-6 mm (R=-0.7676, p<0.001) and > 7mm (R=-0.6447, p<0.001). Conclusions: The data suggest that periodontitis may contribute for differences in systemic inflammatory mediators in diabetic patients.
    PER/IADR Congress 2012; 09/2012
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    ABSTRACT: Virulence of P. gingivalis varies among isolates and this variation may be correlated with surface properties. Data indicated that encapsulated strains are associated with increased virulence in abscess experimental models, whereas the fimbriae are involved with adherence to eukaryotic cells and biofilm formation. Objectives: This study aimed to evaluate whether P. gingivalis isolates present both surfaces structures and if this is correlated with adhesion efficiency to eukaryotic cells. Methods: Nine P. gingivalis isolates and reference strains ATCC 33277 and W83 were evaluated. The gingival epithelial cells OBA-09 were co-cultivated with P. gingivalis isolates and percent of adherent cells determined by viable counts. Capsule was detected by optical microscopy after negative staining and fimbriae determined by TEM. Results: Five isolates presented fimbriae (F) but not capsule (C) (F+C-), two presented capsule but not fimbriae (F-C+), two presented both structures (F+C+) and two none (F-C-). All strains were able to adhere to eukaryotic cells (range from 2.1 to 6.1% of adherent bacterial cells). Although the highest values of adherence were seem among F+C- isolates, there was no correlation between adherence values and the presence of capsule or fimbriae. Conclusions: The data indicated that P. gingivalis isolates evolved different strategies for colonizing epithelial cells.
    PER/IADR Congress 2012; 09/2012
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    ABSTRACT: Objectives: Aggregatibacter actinomycetemcomitans is mainly associated with aggressive periodontitis, which is characterized by extensive alveolar bone loss. It produces the cytolethal distending toxin (AaCDT), which target cells such as epithelial cells, lymphocytes and macrophages. This study evaluated the effect of AaCDT on osteoclastogenesis of a murine monocytes lineage (RAW 264.7). Methods: Recombinant AaCDT (rAaCDT) was added to RAW 264.7 cells in α-MEM with or whitout 50ng/ml RANKL. After 6 days, cell proliferation was estimated by MTT assay, cells were stained with TRAP and TRAP+ multinucleated cells were counted. Transcription of Gene expression for rank, ctpk, nfatc1 and irf-8 was evaluated by RT-qPCR, gapdh was used as control, and the data were analyzed by ANOVA followed by Tukey test (p < 0.05). Results: The addition of 25 and 12 μg/ml rAaCDT led to decrease in cell viability. Addiction of rAaCDT in the absence of RANKL led to increased counts, but not significant, of multinucleated TRAP+ cells. In addition, rAaCDT induced upregulation of transcription of rank, ctpk, nfatc1 and irf-8 in cells incubated with RANKL. Conclusions: CDT may play a role in bone destruction by induction of osteoclasts differentiation.
    PER/IADR Congress 2012; 09/2012
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    ABSTRACT: Objectives: Studies show that A. actinomycetemcomitans (Aa) seems to be associated with the development of periodontal disease in patients with localized aggressive periodontitis (LAP), and other bacterial species such as P. gingivalis (Pg) seem to play a key role in the disease progression. Pathogens such as Aa serotype b and Pg were more frequently detected in patients with generalized aggressive periodontitis (GAP) compared with controls. The prevalence of Aa serotypes may differ according to the geographical location and type of disease, and serotype c was shown to be highly prevalent in Brazil. The ability to induce disease and a strong immune response may also differ among the serotypes. This study investigated the sera IgG levels to Pg and Aa in patients with aggressive periodontitis. Methods: Thirty subjects presenting aggressive periodontitis (25 with GAP and 5 with LAP), aged between 15 to 38 and three healthy negative controls were evaluated for sera antibodies to Pg and Aa serotypes a, b and c by ELISA. For Aa, sera were considered responsive to each serotype when the OD corrected values > mean OD healthy + 7 standard deviation (sd). For Pg, sera were considered responsive when the OD corrected values > mean OD healthy + 2sd. Results: Data revealed that IgG levels were positive for Aa in 13 of 15 Caucasian patients, while only 9 patients of 15 Afro descendant patients were positive. Serotype b was the most prevalent. With respect to Pg, only 7 patients showed high antibody titers, all of them with GAP. Among these 7 patients, six had also response to Aa serotype b. Conclusions: Response to A. actinomycetemcomitans serotype b was shown to be strongly associated with aggressive periodontitis, especially among Caucasian aggressive periodontitis patients.
    PER/IADR Congress 2012; 09/2012
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    ABSTRACT: Chronic periodontitis (CP) has been classified as a multifactorial disease, and both microbial and genetic factors have been associated with risk. Previously, we identified that the ATC/TTC haplotype formed by polymorphisms in the Interleukin 8 gene conferred genetic susceptibility to CP. Objective: : to investigate whether the genetic susceptibility to CP given by the IL8 haplotype influenced the levels of Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), and Treponema denticola (Td) in subgingival sites with and without CP. Method: Subgingival samples were obtained from 65 individuals selected and grouped according to the presence (genetically susceptible individuals) or absence (genetically non-susceptible individuals) of the IL8 gene haplotype. After periodontal clinical evaluation, they were subdivided according to the presence (CP) or absence of periodontitis (H). Two healthy sites and 2 diseased sites were sampled in CP groups and 2 healthy sites in H groups (n=190 samples). It was selected diseased sites in non-adjacent teeth with probing pocket depth (PPD) of 5mm with bleeding on probing (BOP), regarding healthy sites they presented PPD> 2mm and without BOP. The levels of microorganisms were analyzed by absolute quantitative PCR (qPCR). Result: No statistically significant differences were observed for the clinical periodontal parameters between susceptible and non-susceptible patients to CP. Sites of healthy individuals had lower levels of Pg, Tf, and Td than diseased sites of patients with CP both between genetically susceptible and non-susceptible groups (Mann Whitney, p<0.0001). In diseased sites, the levels of Pg, Tf, and Td were significantly higher in genetically non-susceptible than in genetically susceptible individuals (Mann Whitney, p<0.05). Conclusion: Susceptibility to chronic periodontitis given by the haplotype in the Interleukin 8 gene influenced the individual colonization of periodontopathogens in subgingival sites.
    IADR General Session 2012; 06/2012
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    ABSTRACT: Bacterial chromosomes are subject of great plasticity conferred by rearrangements and mutations. These properties result in bacterial diversity which reflects on virulence. Aggregatibacter actinomycetemcomitans lineages differ in their association with disease, although similar isolates may be obtained from diseased and healthy patients. Objective: This study investigated the diversity of A. actinomycetemcomitans by various genotyping methods. Method: Twenty-eight clinical isolates were studied. Analysis of ltx region, serotyping and aae polymorphism were evaluated by PCR. Phylogenetic lineages were determined by multilocus sequence typing (MLST) using 9 housekeeping encoding genes and XhoI DNA fingerprints were resolved by PFGE. Result: MLST and PFGE data revealed that isolates from serotypes b and c were grouped in distinct clusters. MLST was not able to discriminate most serotype c isolates, obtained from very distinct locations, and exhibiting variable copies of a repeat sequence in the aae gene, encoding an adhesin. PFGE was more discriminatory than MLST for serotype c isolates. On the other hand, serotype a isolates were very diverse by both PFGE and MLST analysis, exhibiting marked distance between strains. Highly leukotoxic strains were divided in more than one phylogenetic lineage, within the serotype b cluster. Conclusion: The data indicated that serotype a isolates exhibit extensive genotypic diversity, whereas the differences within serotype c isolates may result mostly from chromosomal rearrangements.
    IADR General Session 2012; 06/2012
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    ABSTRACT: Objective: The prevalence of the A.actinomycetemcomitans serotypes may differ according to the geographical location and type of disease, and serotype c was shown to be highly prevalent in Brazil. The ability to induce disease and a strong immune response may also differ among the serotypes. This study investigated the sera IgG levels to A. actinomycetemcomitans in patients with aggressive periodontitis. Methods: Twenty six subjects presenting aggressive periodontitis, aged 19 to 35 and three healthy negative controls were evaluated for sera antibodies to A.actinomycetemcomitans serotypes a, b and c by ELISA. Sera were considered responsive to each serotype when the OD corrected values > mean OD healthy + 7sd. Results: Data revealed that IgG levels were positive for A.actinomycetemcomitans in 6 of 12 afro descendant patients. Five of these positive patients had high antibodies titers to serotype b, including 3 responsive also to serotypes a and /or c. However, an immune response to A.actinomycetemcomitans was observed in 12 of 14 Caucasian subjects. Ten of these subjects were immune responsive to serotype b, including 4 sera responding also to serotypes a and/or c. Conclusion: response to A.actinomycetemcomitans serotype b was shown to be strongly associated with generalized aggressive periodontitis, especially among Caucasian aggressive periodontitis patients. This abstract is based on research that was funded entirely or partially by an outside source: FAPESP 2010/16162-1 Keywords: Periodontal disease, Periodontal organisms and Serum-plasma
    06/2012
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    ABSTRACT: Enterococcal species are opportunistic pathogens which can cause infections in different areas of the body. In the oral cavity, E. faecalis is the predominant bacterial species associated with periradicular lesions in root-filled teeth in which endodontic treatment had failed. The presence of capsule may contribute to the pathogenesis of enterococcal infections through evasion of the host innate immune system. Objective: The present study aimed to investigate capsule (cps) locus polymorphisms among E. faecalis isolates from root canal infections and systemic diseases. Method: Forty E. faecalis isolates were examined for their ability to produce capsule in relation to the source of isolation. The 3 known CPS types were determined by polymerase chain reaction: CPS 1, which lacks capsule expression, and CPS 2 and 5, which have the essential genes in the cps operon for capsule production. Result: Among endodontic isolates, 60% (12/20) were classified as CPS 1, 25% (5/20) CPS 2, and 10% (2/20) CPS 5. In contrast, 55% (11/20) of medical isolates were classified as CPS 5, whereas only 35% (7/20) were CPS 1. Conclusion: Certain E. faecalis strains from canals of root-filled teeth with periapical lesions belong to lineages associated with capsule expression, although in a lower prevalence than in the hospital infections.
    IADR General Session 2012; 06/2012

Publication Stats

554 Citations
76.10 Total Impact Points

Institutions

  • 1998–2013
    • University of São Paulo
      • • Instituto de Ciências Biomédicas (ICB)
      • • Department of Immunology (ICB)
      • • Faculdade de Odontologia (FO) (São Paulo)
      San Paulo, São Paulo, Brazil
  • 2011
    • Universidade Guarulhos
      Guarulhos, São Paulo, Brazil
  • 2010
    • Instituto de Pesquisas Energéticas e Nucleares
      • Center for Laser and Applications (CLA)
      San Paulo, São Paulo, Brazil
  • 2001
    • The Forsyth Institute
      Cambridge, Massachusetts, United States