2,918 research outputs found

    Developments in the Law: Title Protection

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    Relationships Among IL-6, TNF-α, Adipokines, Vitamin D and Chronic Periodontitis

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    Objectives to explore relationships among serum adipokines, vitamin D, clinical and microbial parameters of chronic periodontitis before and after treatment. Methods weight, height and smoking status were recorded for 56 patients with chronic periodontitis. Plaque, gingivitis, bleeding on probing (BOP), suppuration, pocket depth (PD) and attachment level (AL) were measured at all teeth present. Subgingival biofilm samples from each tooth were analyzed for levels of 40 bacterial species using checkerboard DNA-DNA hybridization. Serum levels of interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), adiponectin, leptin, resistin and vitamin D were measured at baseline. Sample collection was then performed in a subset of the population 6 months post-therapy (n=17). Serum samples were analyzed using ELISA and immunoassays. Differences in clinical, microbial and serum factors among groups were sought using the Mann-Whitney test. Correlations among factors were evaluated using regression analysis. Effects of therapy were sought using the Wilcoxon signed ranks test Results There were positive correlations between adiponectin/vitamin D and between IL-6/leptin; negative correlations between IL-6/vitamin D, and leptin/vitamin D, but no associations between serum analytes and clinical or microbial parameters. Gender and BMI were associated with levels of adipokines. Periodontal therapy improved clinical and microbiological parameters, but did not influence the levels of serum analytes. Conclusions Adipokines and IL-6 levels were affected by gender and BMI. Serum analytes were not influenced by periodontal therapy

    Bases microbiolĂłgicas para a terapia periodontal

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    The search for the etiologic agents of periodontal diseases started in the Golden Era of medical bacteriology, when the etiologic agents of many bacterial infections were isolated and characterized. After the initial enthusiasm in establishing the infectious nature and the true agents of periodontal diseases, this concept was virtually ignored for the next four decades. Until the early 1970s treatment regimens based on the non-specific plaque hypothesis were directed towards a non-specific reduction in plaque amount. Later, the specific plaque hypothesis established the role of some microorganisms such as A. actinomycetemcomitans, P. gingivalis, T. forsythensis, T. denticola, P. intermedia and F. nucleatum in different forms of periodontal diseases. It was recently suggested that these suspected periodontal pathogens seem to not act alone and interactions between species, especially the balance between pathogenic and beneficial species affect both progression of disease and response of tissues to periodontal therapy. Nowadays it is well established that one of the goals of therapy is to control such periodontal pathogens. Among the most commonly used therapies to treat periodontal infections are scaling and root planing (SRP), supragingival plaque control and periodontal surgeries. Many studies confirmed the reduction of "red complex" species by SRP, and apically repositioned flap can lead to an additional beneficial effect in the subgingival microbiota by decreasing levels of "red" and "orange complexes" species. Furthermore, the level of plaque control maintained by the patients has been considered a crucial step in preventing recurrence of destructive periodontitis.A busca pelos agentes etiológicos das doenças periodontais iniciou na Época de Ouro da bacteriologia médica, quando os agentes de diversas infecções foram identificados. Após o entusiasmo inicial em estabelecer a natureza infecciosa da doença periodontal, este conceito foi ignorado por quatro décadas. Até o início dos anos 70, terapias baseadas na hipótese da placa não-específica focavam a redução da quantidade de placa. Posteriormente, a hipótese da placa específica determinou o papel de alguns microorganismos como A.actinomycetemcomitams, P.gingivalis, T.forsythensis, T.denticola , P.intermedia e F.nucleatum nas diferentes formas de doença periodontal. Recentemente, foi sugerido que estes patógenos periodontais não atuam isoladamente e interações entre espécies, como o equilíbrio entre bactérias patogênicas e benéficas afetam a progressão da doença e a resposta tecidual à terapia periodontal. Atualmente está bem estabelecido que um dos objetivos da terapia é o controle destes patógenos. Dentre as terapias mais freqüentemente utilizadas no tratamento da periodontite estão raspagem e alisamento radicular (RAR), controle da placa supragengival e cirurgias periodontais. Muitos estudos confirmaram a redução de espécies do "complexo vermelho" pela RAR, e mostraram que o retalho reposicionado apicalmente pode levar a um efeito benéfico adicional na microbiota subgengival pela diminuição nos níveis de espécies dos "complexos vermelho" e "laranja". Além disso, o controle de placa mantido pelos indivíduos é considerado determinante para a prevenção da recorrência de doença periodontal destrutiva

    RNA-Oligonucleotide Quantification Technique (ROQT) for the Enumeration of Uncultivated Bacterial Species in Subgingival Biofilms

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    Approximately 35% of the species present in subgingival biofilms are as yet uncultivated, so their role in periodontal pathogenesis is unknown. The aim of the present study was to develop a high throughput method to quantify a wide range of cultivated and uncultivated taxa in subgingival biofilm samples associated with periodontal disease or health. Oligonucleotides targeting the 16S ribosomal DNA gene were designed, synthesized and labeled with digoxigenin. These probes were hybridized with the total nucleic acids of pure cultures or subgingival biofilm samples. Target species included cultivated taxa associated with periodontal health and disease, as well as uncultivated species, such as TM7 sp OT 346, Mitsuokella sp. OT 131 and Desulfobulbus sp. OT 041. Sensitivity and specificity of the probes were determined. A Universal probe was used to assess total bacterial load. Sequences complementary to the probes were used as standards for quantification. Chemiluminescent signals were visualized after film exposure or using a CCD camera. In a pilot clinical study, 266 subgingival plaque samples from eight periodontally healthy people and 11 patients with periodontitis were examined. Probes were specific and sensitivity reached 104 cells. Fusobacterium nucleatum ss polymorphum and Actinomyces gerencseriae were the most abundant cultivated taxa in clinical samples. Among uncultivated/unrecognized species, Mitsuokella sp. OT 131 and Prevotella sp. OT 306 were the most numerous. Porphyromonas gingivalis and Desulfobulbus sp. OT 041 were only detected in patients with periodontitis. Direct hybridization of total nucleic acids using oligonucleotide probes permitted the quantification of multiple cultivated and uncultivated taxa in mixed species biofilm samples

    Genetic dysbiosis: the role of microbial insults in chronic inflammatory diseases

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    This review was undertaken at UCL, which received a proportion of funding from the Department of Health’s National Institute of Health Research (NIHR) Biomedical Research Centres funding scheme

    Relationship between C-telopeptide pyridinoline cross-links (ICTP) and putative periodontal pathogens in periodontitis

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    Crevicular fluid pyridinoline cross-linked carboxyterminal telopeptide of type 1 collagen (ICTP) is predictive for future alveolar bone loss in experimental periodontitis in dogs. The present study sought to relate ICTP to a panel of subgingival species in subjects exhibiting various clinical presentations such as health ( n = 7), gingivitis ( n = 8) and periodontitis (n=21), 28 subgingival plaque and GCF samples were taken from mesiobuccal sites m each of 36 subjects. The presence and levels of 40 subgtngivai taxa were determined in plaque samples using whole genomic DNA probes and checkerboard DNA-DNA hybridization. GCF ICTP levels were quantified using radioimmunoassay (RIA). Clinical assessments made at the same sites included: BOP, gingival redness, plaque, pocket depth, and attachment level. Differences among ICTP levels in the 3 subject groups were sought using the Kruskal-Wallis test. Relationships between ICTP levels and clinical parameters as well as subgingival species were determined by regression analysis. The results demonstrated significant differences among disease categories for GCF ICTP levels for healthy (1.1+0.6 pg/site (mean±SEM)) gingivitis (14.8±6.6 pg/site) and penodontitts subjects (30.3 + 5.7 pg/site) ( p = 0.0017). ICTP levels related modestly to several clinical parameters. Regression analysis indicated that ICTP levels correlated strongly with mean subject levels of several periodontal pathogens including B. forsythus, P. gingivitis, P. intermedia, P. nigrescens and T. dentcola ( p < 0.01). The data indicate that there is a positive relationship between the putative bone resorptive marker ICTP and periodontal pathogens.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74809/1/j.1600-051X.1998.tb02383.x.pd

    Microbial Ecosystem Analysis in Root Canal Infections Refractory to Endodontic Treatment

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    Introduction To combine Multiple Displacement Amplification (MDA) and checkerboard DNA–DNA hybridization to qualitatively and quantitatively evaluate the microbiota present in infections refractory to endodontic treatment. Methods The subjects of this study were 40 patients presenting periapical lesions refractory to endodontic treatment. Samples were taken by scraping or filing root canal walls with a #10 K-type hand file. Sample DNA was amplified by MDA, and the levels of 107 bacterial taxa were analyzed by checkerboard DNA–DNA hybridization. The taxa were divided into three distinct microbial populations, depending on their mean proportion in samples (% DNA probe counts ± SEM), as follows: dominant (≥3.0%), sub-dominant (\u3e1.6 to 3.0%) and residual (≤1.6%) populations. The significance of differences was determined using the Mann-Whitney test. Results The taxa present with the highest mean proportions (constituting the dominant population) were Corynebacterium diphtheriae (8.03±0.98), Porphyromonas gingivalis (5.42±2.09), Streptococcus sobrinus (5.33±0.69), and Stenotrophomonas maltophilia (4.72±1.73). Among the sub-dominant population were Eubacterium saphenum (3.85±1.06), Helicobacter pylori (3.16±0.62), Dialister pneumosintes (3.12±1.1), Clostridium difficile (2.74±0.41), Enterobacter agglomerans (2.64±0.54), Salmonella enterica (2.51±0.52), Mobiluncus mulieris (2.44±0.6), and Klebsiella oxytoca (2.32±0.66). In the population of bacteria present at the lowest mean proportions (the residual population), Bacteroides ureolyticus (0.04±0.01), Haemophilus influenzae (0.04±0.02), and Prevotella oris (0.01±0.01) were found at the lowest mean proportions. Enterococcus faecalis was detected in the residual population (0.52±0.26). Conclusion The microbial climax community in teeth refractory to endodontic treatment not only harbor medically important species, but also contains distinct microbial consortia present with different population levels

    Relationships Among Gingival Crevicular Fluid Biomarkers, Clinical Parameters of Periodontal Disease, and the Subgingival Microbiota

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    Background The objectives were to measure the levels of gingival crevicular fluid (GCF) biomarkers and subgingival bacterial species in periodontally healthy and periodontitis subjects in order to explore relations among these biomarkers, the subgingival microbiota, and clinical parameters of periodontal disease. Material and methods Clinical periodontal parameters were measured at 6 sites per tooth in 20 periodontitis and 20 periodontally healthy subjects. GCF and subgingival plaque samples were obtained from the mesiobuccal aspect of every tooth. GCF levels of interleukin-1β (IL-1β), matrix metalloproteinase-8 (MMP-8) and IL-8 were measured using checkerboard immunoblotting and the levels of 40 bacterial taxa quantified using checkerboard DNA-DNA hybridization. A subset of “clinically healthy” (CH) sites from each group was analyzed separately. Significance of differences between groups was determined using the unpaired t-test or the Mann-Whitney test. Correlations among immunological, microbiological and clinical data were determined using the Spearman rank correlation coefficient. Results There were positive correlations among mean clinical parameters and mean levels of the 3 biomarkers and proportions of Orange and Red complex species (p\u3c0.05). CH sites from periodontitis subjects had higher levels of IL-1β and IL-8 and higher proportions of Orange and Red complex species (p\u3c0.05) than CH sites from periodontally healthy subjects. Red complex species were positively associated with the expression of all biomarkers (p\u3c0.05), while Purple and Yellow complex species had negative correlations with IL-1β and IL-8 (p\u3c0.05). Conclusions CH sites from periodontitis subjects present higher levels of GCF biomarkers and periodontal pathogens than CH sites from periodontally healthy subjects. Different microbial complexes demonstrated distinct associations with specific GCF biomarkers
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