Philosophiae Doctor - PhD / Adverse pregnancy outcomes such as preterm birth and low birth weight are major causes of maternal and neonatal morbidity and mortality. Increasing evidence points to an association between periodontal disease and adverse pregnancy outcomes and thus a better understanding of the nature of this association will assist in treatment planning to reduce adverse pregnancy outcomes. Among the Gram-negative anaerobic bacteria frequently associated with periodontal disease are Treponema denticola, Tannerella forsythia and Porphyromonas gingivalis which may be detected in plaque using the BANA test (N-benzoyl-DL-arginine-2-naphthylamide). The aim of this study was to investigate the effect of periodontal disease on pregnancy outcomes and evaluate the use of BANA as a screening test for the risk of adverse pregnancy outcomes. This study complied with the Declaration of Helsinki (2013) and included 443 pregnant women attending ante-natal clinics in KwaZulu Natal. At first visit, maternal oral health status was assessed by the measurement of periodontal indices and BANA testing of dental plaque from the same teeth. Patient demography and medical history were obtained by means of a questionnaire and all data compared with pregnancy outcomes. While controlling for other factors, significant differences were found between the distributions of periodontal disease at BANA-negative and BANA-positive sites and between infant birth weight and maternal periodontal index scores such as plaque index and gingival index. The birth weight and gestational age at delivery of infants born of BANA-positive periodontally diseased mothers were significantly lower than those born of BANA-negative mothers with no periodontal disease. We may conclude that the presence of periodontal disease during pregnancy has a significant association with negative pregnancy outcomes and suggest that the risk for adverse pregnancy outcomes may be reduced by monitoring the oral health status of women during pregnancy.

Orientadores: Reginaldo Bruno Gonçalves, Cristiane Duque / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-16T07:13:26Z (GMT). No. of bitstreams: 1 Sardi_JanainadeCassiaOrlandi_D.pdf: 1215494 bytes, checksum: 51470817af2a54ba8f45aa4374a2e52f (MD5) Previous issue date: 2010 / Resumo: Candida spp. são leveduras comensais que habitam diferentes sítios da cavidade bucal. Em indivíduos saudáveis, sem alterações imunológicas, esses microrganismos não causam doença. Entretanto, diante de condições imunossupressoras, essas leveduras podem se tornar mais virulentas e expressar patogenicidade. Espécies de Candida apresentam diversos fatores de virulência, incluindo mecanismos de adesão e invasão celular associado à produção de enzimas que auxiliam na degradação tecidual e facilitam sua proliferação na mucosa bucal. Estudos têm demonstrado a presença de Candida sp. em sítios periodontais de pacientes com periodontite crônica, principalmente quando estes são imunologicamente comprometidos. Entretanto, ainda é desconhecido o papel desses microrganismos na patogênese da doença periodontal. Os objetivos do presente trabalho foram: 1) identificar a presença de espécies de Candida e periodontopatógenos por PCR em sítios bucais de pacientes diabéticos ou não com periodontite crônica; 2) isolar cepas de Candida albicans desses pacientes e avaliá-las quanto à atividade das enzimas proteinase, fosfolipase e hemolisina e os graus de hidrofobicidade da superfície celular, sob diferentes condições atmosféricas, além de realizar a análise genotípica desses isolados; 3) avaliar a capacidade de adesão e invasão de cepas de Candida albicans com diferentes graus de hidrofobicidade, em fibroblastos gengivais humanos. As reações de PCR mostraram que os diabéticos tiveram maior prevalência de Candida spp. principalmente C. albicans e C. dubliniensis, e menor freqüência de Tannerella forsythia, quando comparado aos pacientes não diabéticos, para bolsa periodontal e furcas. C. glabrata e C. tropicalis não foram encontradas em sítios periodontais de pacientes não diabéticos. Dos pacientes diabéticos, foram isoladas 128 cepas de C. albicans, das quais 51.6% foram determinadas como genótipo B e 48.4% como genótipo A. As condições ambientais consideradas neste estudo, níveis reduzidos de oxigênio ou anaerobiose, não modificaram o tipo de hemólise realizado pelo microrganismo, sendo que a maioria das cepas foi alfa-hemolítica. Nesses ensaios, 100% das cepas em anaerobiose apresentaram as colônias rugosas, enquanto que em ambiente de oxigênio reduzido, houve variação em relação à morfologia e a maioria delas apresentou colônia lisa. Com relação à atividade de proteinase e fosfolipase, cepas de C. albicans não produziram as enzimas na ausência total de oxigênio. Em ambiente com nível reduzido de oxigênio, a maioria das cepas de C. albicans foram fortemente produtoras de proteinase e a maioria das cepas foi positiva para fosfolipase. A hidrofobicidade foi mais alta na condição de anaerobiose. A partir desses resultados, foram selecionadas 16 cepas com alta ou baixa hidrofobicidade e avaliadas quanto à capacidade de adesão e invasão em fibroblastos gengivais humanos. Foi verificado que ambos os processos foram maiores nas cepas com alta hidrofobicidade. A produção de óxido nítrico foi maior para as cepas mais hidrofóbicas. Os resultados demonstraram que as espécies de Candida podem ser encontradas, em grande proporção, em bolsas periodontais e furcas de pacientes portadores de periodontite crônica, principalmente naqueles acometidos por diabetes mellitus. A maioria das cepas de C. albicans apresentou atividade enzimática, que atuaria diretamente na degradação tecidual. Além disso, a hidrofobicidade das cepas de C. albicans mostrou estar relacionada à maior capacidade de adesão e invasão em fibroblastos. Todos esses fatores de virulência aumentam a patogenicidade da Candida, que poderia colaborar na progressão da doença periodontal, principalmente em pacientes imunodeficientes / Abstract: Candida spp. are commensal yeasts that inhabit different sites of the oral cavity. In healthy subjects, without immunological alterations, these microorganisms do not cause disease. However, in immunosuppressive conditions, these yeasts can become more virulent and express pathogenicity. Candida species have different virulence factors, including mechanisms of cell adhesion and invasion associated with the production of enzymes that facilitate tissue degradation and their proliferation in oral mucosa. Studies have shown the presence of Candida spp. in periodontal sites of patients with chronic periodontitis, especially when they are immunologically compromised. However is still unknown their role in the pathogenesis of periodontal disease. The objectives of this study were: 1) to identify the presence of Candida species and putative periodontopathogens by PCR in periodontal sites of diabetic or non-diabetic patients with chronic periodontitis; 2) to isolate strains of Candida albicans in these patients and evaluate the proteinase, phospholipase and haemolysin activities and degrees of cell surface hydrophobicity under different atmospheric conditions, besides to performe the genotypic analysis of these isolates; 3) to evaluate the ability of adhesion and invasion of Candida albicans strains with different degrees of hydrophobicity, in human gingival fibroblasts. The PCR reactions revealed that diabetics had higher prevalence of Candida spp., mainly C. albicans and C. dubliniensis, and lower T. forsythia frequency, when compared to non-diabetic patients, for both periodontal sites. C. glabrata and C. tropicalis were not found in periodontal pockets and furcation sites of non-diabetic patients. From diabetic patients, it was isolated 128 strains of C. albicans and 51.6% were determined as genotype B and 48.4% as genotype A. The atmospheric conditions, reduced oxygen and anaerobiosis, did not change the type of hemolysis, and the most of strains were alpha-hemolytic. From these assays, 100% of the strains under anaerobiosis showed rough colonies, whereas in an environment with reduced oxyen was no change in relation to morphology and most of them had smooth colony. Considering proteinase and phospholipase activities, C. albicans strains did not produce the enzymes in the total absence of oxygen. In reduced oxygen, the majority of C. albicans strains were strong proteinase producers and most strains were positive for phospholipase. Hydrophobicity was higher in anaerobic condition. From these results, 16 hydrophobic or hydrophilic strains were selected and evaluated their ability of adhesion and invasion in human gingival fibroblasts. Both processes were greater in strains with high hydrophobicity. The production of nitric oxide was higher for hydrophobic strains. The results showed that Candida species can be found in large proportion, in periodontal pockets and furcation of patients with chronic periodontitis, especially diabetics. The most of C. albicans strains showed enzymatic activity, which could act directly on tissue degradation. Moreover, the hydrophobicity of C. albicans seems to be related to higher capacity of adhesion and invasion in fibroblasts. All these virulence factors enhance the pathogenicity of Candida that could collaborate for the progression of periodontal disease / Doutorado / Microbiologia e Imunologia / Doutor em Biologia Buco-Dental

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / As doenÃas periodontais sÃo as principais causas de perda de dentes em adultos. O fator etiolÃgico preponderante para desencadear a periodontite à o acumulo do biofilme dental com predominÃncia de bactÃrias anaerÃbicas gram negativas. Apesar de ser de origem bacteriana a resposta inflamatÃria induzida a partir de fatores do hospedeiro pode influenciar na progressÃo e nas caracterÃsticas clÃnicas da doenÃa periodontal. A perda Ãssea alveolar à tÃpica na evoluÃÃo desta patologia e dependente da atividade osteoclÃstica. Por sua vez, um dos mecanismos de reabsorÃÃo Ãssea por estas cÃlulas à atravÃs da produÃÃo de prÃtons liberados nos vacÃolos de reabsorÃÃo pela atividade da anidrase carbÃnica. Tem sido relatado que inibidores desta enzima, como acetazolamida, tem aÃÃo supressora sobre osteoclastos. O objetivo deste estudo foi analisar o efeito da acetazolamida (ACTZ) na perda Ãssea induzida no modelo de periodontite experimental em ratos, bem como a dosagem de biomarcadores sÃricos do processo inflamatÃrio periodontal e anÃlise histolÃgica do periodonto. AnÃlises de seguranÃa tambÃm foram realizadas atravÃs de hemograma completo, dosagens de TGP, TGO, gama-GT e histopatologia de ÃrgÃos como: fÃgado, rins, baÃo, coraÃÃo e pulmÃo. Para avaliaÃÃo da perda Ãssea alveolar 50 ratos receberam ligaduras de nylon na regiÃo do segundo molar superior esquerdo. Os animais foram divididos em seis grupos: Grupo veÃculo (propilenoglicol) (n=9), grupo controle positivo (alendronato 0,08 mg/Kg) (n=7), grupo controle negativo (salina) (n=9) e grupos que receberam acetazolamida via I.P. nas doses (8,3, 25 e 75 mg/Kg [grupos ACTZ8,3, ACTZ25 e ACTZ75, respectivamente] n= 7, 9 e 9). ApÃs 11 dias, os ratos foram mortos. A perda Ãssea alveolar foi avaliada macroscopicamente atravÃs da Ãrea de exposiÃÃo de raiz. Em outros quatro grupos, ACTZ25 (n=5) e veÃculo (n=5), o periodonto foi analisado histologicamente apÃs 11 e 17 dias de ligadura por coloraÃÃo em HE. Biomarcadores sÃricos foram dosados (IL-1&#61537;, IL-4, fractalkine, CINC-2, CINC-3, LIX, GM-CSF, &#946;NGF, VEGF e CNTF) atravÃs da tÃcnica de microarray antes e depois da ligadura em trÃs grupos; ACTZ25, Veiculo e Sham (cirurgia simulada). No grupo de ACTZ25 foi realizada a anÃlise de seguranÃa (alpha=5%). Macroscopicamente, o grupo alendronato (controle positivo) apresentou a menor perda Ãssea, seguido do grupo ACTZ75 e ACTZ25 (p<0.05) quando comparados aos controles veÃculo e salina que nÃo diferiram entre si (p>0.05). Histologicamente, o grupo ACTZ apresentou a menor reabsorÃÃo de osso e cemento (p<0,05) apÃs 17 dias de ligadura, nÃo houve diferenÃa entre o grupo ACTZ25 e o veÃculo quanto ao infiltrado inflamatÃrio (P>0,05) . As maiores concentraÃÃes de IL-4 e CNTF foram observadas no grupo ACTZ25 (p< 0,05) quando comparado ao grupo veÃculo. As anÃlises de seguranÃa demonstraram que acetazolamida na dosagem de 25 mg/Kg foi bem tolerada sem alteraÃÃes significativas do hemograma, nas enzimas hepÃticas e histopatologia dos ÃrgÃos pesquisados. ConcluÃmos que a acetazolamida pode proteger o periodonto da reabsorÃÃo Ãssea induzida por ligadura em ratos e pode estar associada a mediadores envolvidos com o reparo, como a IL-4 e CNTF, alÃm de ser bem tolerada. / Periodontal diseases are the main cause of tooth loss in adults. The preponderant etiologic factor for the onset of periodontitis is the accumulation of dental biofilm with predominance of anaerobic gram negative bacteria. In spite of being of bacterial origin, the inflammatory response induced by factors in the host may influence the progression and clinical characteristics of periodontal disease. Alveolar bone is typical in the development of this pathology and is dependent on osteoclastic activity. In turn, one of the mechanisms of bone resorption by these cells is through the production of protons released in the resorption vacuoles by carbonic anhydrase activity. It has been reported that carbonic anhydrase inhibitors, such as acetazolamide, have a suppressive action on osteoclasts. The aim of this study was to analyze the effect of acetazolamide (ACTZ) on bone loss induced in the experimental periodontitis model in rats, as well as the dosage of seric biomarkers in the periodontal inflammatory process and histologic analysis of the periodontium. Safety analyses were also performed by means of a complete hemogram, biochemical tests for TGP, TGO, gama-GT and histopathology of organs such as: the liver, kidneys, spleen, heart and lungs. To evaluate alveolar bone loss, 50 rats received nylon ligatures in the maxillary left second molar region. The animals were divided into six groups: Vehicle Group (propylenoglycol) (n=9), Positive Control Group (alendronate 0.08 V (n=7), Negative Control Group (saline) (n=6) and Groups that received acetazolamide I.P. in the following doses: (8.3, 25 and 75 mg/Kg [Groups ACTZ8,3, ACTZ25 and ACTZ75 respectively] n= 7, 9 and 9). After 11 days, the rats were sacrificed. Alveolar bone loss was macroscopically evaluated by means of the area of root exposure. In another four groups, ACTZ25 (n=5) and vehicle (n=5), the periodontium was histologically analyzed after 11 and 17 days of ligature, by HE staining. Seric biomarkers were dosed (IL-1&#61537;, IL-4, fractalkine, CINC-2, CINC-3, LIX, GM-CSF, &#946;NGF, VEGF and CNTF) by means of the microarray technique before and after ligature in three groups; ACTZ25, Vehicle and Sham (simulated surgery). In the ACTZ25 group, safety analysis was performed (alpha=5%). Macroscopically, the alendronate Group (positive control) presented the lowest bone loss, followed by Groups ACTZ75 and ACTZ25 (p<0.05) when compared with the vehicle and saline controls, which did not differ between them (p>0.05). Histologically, the ACTZ group presented the lowest bone and cement resorption (p<0.05) after 17 days of ligature, and there was no difference between the ACTZ25 and vehicle groups with regard to inflammatory infiltrate (P>0.05). The highest concentrations of IL-4 and CNTF were observed in Group ACTZ25 (p< 0.05) when compared with the vehicle group. The safety analyses demonstrated that acetazolamide at the dose of 25 mg/Kg was well tolerated without significant alterations in the hemogram, hepatic enzymes and histopathology of the researched organ. It was concluded that acetazolamide may protect the periodontium from bone resorption induced by ligature in rats, and may be associated with mediators involved in repair, such as IL-4 and CNTF, in addition to being well tolerated.

Please read the abstract in the front section of this document / Dissertation (MChD (Periodontics and Oral Medicine))--University of Pretoria, 2007. / Oral Pathology and Oral Biology / unrestricted

No description available.

No description available.

No description available.

Periodontitis is an infective disease caused predominantly by gram negative anaerobic bacteria. However it is apparent that alveolar bone loss, which characterises periodontitis, is a result of the host inflammatory response to pathogenic bacteria, not the infectious agents directly. Omega-3 polyunsaturated fatty acids (O-3 PUFAs) are recognised, and used widely, for their anti-inflammatory effects. Evidence is emerging that their oxygenated derivatives are key chemical mediators in the resolution of inflammation. We hypothesised that dietary supplementation with fish oil rich in the O-3 PUFA docosahexaenoic acid would modify inflammatory reactions within the periodontium and thus reduce alveolar bone loss in mice infected with periodontopathic bacteria. Eighty mice were fed experimental diets containing either 10% tuna oil (40) or a sunola oil (40) which contained no traceable O-3 PUFAs for 57 days. After two weeks each dietary set was split into four groups of ten mice, with these groups being inoculated with either a) Porphyromas gingivalis b) P. gingivalis and Fusobacterium nucleatum (combined inoculum) c) Carboxymethylcellulose (control) or d) No inoculations (control). Of the twenty mice which received no inoculations, half were sacrificed after fifteen days and half at the end of the experiment to enable comparative fatty acid analysis of the oral soft tissues. Results demonstrated that eicosapentoic acid and docosahexaenoic acid were found in significantly higher proportions in the oral soft tissues of mice fed a tuna oil diet, and that animals receiving this diet exhibited an average of 54 - 72% less alveolar bone resorption in response to the different bacterial infections. Irrespective of diet, the combined inoculum resulted in slightly more alveolar resorption than P. gingivalis alone. The findings of this study suggest that fish oil dietary supplementation may have potential benefits as a host modulatory agent in the adjunctive management of periodontitis. Given its advantages in terms of safety, cost effectiveness and widespread availability, this dietary supplement warrants further research in human trials to assess its ability to modulate alveolar bone loss in individuals with periodontitis. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1313252 / Thesis (D.Clin.Dent.) - University of Adelaide, School of Dentistry (Periodontics), 2008

Fusobacterium nucleatum is a saccharolytic Gram-negative anaerobic organism belonging to the so-called ‘orange complex’ which is believed to play an important role in the microbial succession associated with the pathogenesis of periodontal disease. Its genome contains niche-specific genes shared with the other inhabitants of dental plaque, which may help to explain its ability to survive and grow in the changing environmental conditions experienced in the gingival sulcus during the progression from health to disease. The pH of the gingival sulcus increases during the development of periodontitis and is thought to occur by the metabolism of nutrients supplied by gingival crevicular fluid. Studies have shown that F. nucleatum is partly responsible for the rise in pH and have concluded that in comparison to other plaque inhabitants, F. nucleatum has the greatest ability to neutralise acidic environments. In common with a number of other oral bacteria, F. nucleatum has also been shown to produce intracellular polyglucose (IP) from simple sugars such as glucose, galactose and fructose. Its response and adaptation to stressful environmental conditions such as pH is unknown. The overall aim of this study was, therefore, to determine how F. nucleatum copes with environmental stresses induced by pH changes. F. nucleatum was grown by continuous culture in a chemically defined medium at a growth rate corresponding to those measured in vivo. The effect on protein expression, and IP synthesis was examined during steady-state growth at high (>7.2<7.8) or low pH (pH 6.4). The present study also investigated the response of F. nucleatum to growth at pH 8.2. It was found that the organism grew as a biofilm and this corresponded with an increase in cellular hydrophobicity and decreased IP levels. Optimal growth pH’s differed between the different sub-species used in this study. In response to pH stress, F. nucleatum changed its amino acid and glucose utilisation and increased IP synthesis at the expense of cell numbers. Pulsing the chemostat with glutamic acid or serine produced an increase in IP synthesis and the pattern of end-products observed was dependent upon the amino acid being fermented. The effect on IP synthesis in response to increased levels of exogenous fermentable amino acids was also compared during concomitant fructose or glucose fermentation. Growth media containing fermentable amino acids and supplemented with fructose produced higher cell numbers and non-detectable levels of IP compared to media containing glucose. The differential expression of cytoplasmic- and cell envelope-proteins induced by changes in pH were identified by two-dimensional gel electrophoresis. The results represent the first proteomic investigation of F. nucleatum. Twenty-two cytoplasmic proteins were found to have altered expression in response to external pH. At low (sub-optimal) pH, proteins associated with the generation of ATP and ammonia were up-regulated, the latter contributing to the alkalinisation of the gingival sulcus. Conversely, neutral to alkaline pH conditions led to the upregulation of enzymes involved in energy storage. The study also identified several proteins associated with iron limitation and fatty acid synthesis which might not otherwise have been identified as part of the pH-dependent response. In response to growth at pH 7.8, 14 cell envelope proteins were identified as having significantly altered expression. Down-regulated proteins included those associated with uptake of C4 di-carboxylates and phosphorus, a potential membrane protease and an enzyme associated with amino acid fermentation. The up-regulation of a transcriptional regulator linked to the repression of sugar metabolism was also reported along with proteins linked to the transport of iron. The periplasmic chaperone, peptidyl prolyl cis trans isomerase, which is responsible for the folding of outer membrane proteins, was also found to be up-regulated. In conclusion, the proteomic investigation of protein expression by F. nucleatum identified gene products which form part of the organism’s coordinated stress response to changes in environmental pH. In addition to these, the physiological based studies also presented help to explain the organism’s persistence during the transition from health to disease in vivo. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1339503 / Thesis (Ph.D.) - University of Adelaide, Dental School, 2008

Proefschrift--Rijsuniversiteit te Groningen, 1979. / Thesis statement on title page in Dutch. Summary in Dutch. Includes bibliographical references (p. 126-146).