Immune response to cytolethal distending toxin of Aggregatibacter actinomycetemcomitans in periodontitis patients

Background and Objective: Cytolethal distending toxin (CDT) is a genotoxin produced by Aggregatibacter actinomycetemcomitans. In spite of its association with pathogenesis, little is known about the humoral immune response against the CDT. This study aimed to test whether subgingival colonization and humoral response to A. actinomycetemcomitans would lead to a response against CDT. Material and Methods: Sera from periodontally healthy, localized and generalized aggressive periodontitis and chronic periodontitis subjects (n = 80) were assessed for immunoglobulin G titers to A. actinomycetemcomitans serotypes a/b/c and to each CDT subunit (CdtA, CdtB and CdtC) by ELISA. A. actinomycetemcomitans subgingival levels and neutralization of CDT activity were also analyzed. Results: Sera from 75.0% localized and 81.8% generalized aggressive periodontitis patients reacted to A. actinomycetemcomitans. A response to serotype b was detected in localized (66.7%) and generalized aggressive periodontitis (54.5%). Reactivity to A. actinomycetemcomitans correlated with subgingival colonization (R = 0.75, p < 0.05). There was no correlation between A. actinomycetemcomitans colonization or response to serotypes and the immunoglobulin G response to CDT subunits. Titers of immunoglobulin G to CdtA and CdtB did not differ among groups; however, sera of all generalized aggressive periodontitis patients reacted to CdtC. Neutralization of CDT was not correlated with levels of antibodies to CDT subunits. Conclusion: Response to CdtA and CdtB did not correlate with the periodontal status of the subject in the context of an A. actinomycetemcomitans infection. However, a response to CdtC was found in sera of generalized but not of localized aggressive periodontitis subjects. Differences in response to CdtC between generalized and localized aggressive periodontitis subjects indicate that CDT could be expressed differently by the infecting strains. Alternatively, the antibody response to CdtC could require the colonization of multiple sites.

Collagenase production and hemolytic activity related to 16S rRNA variability among Parvimonas micra oral isolates

Parvimonas micra are gram positive anaerobic cocci isolated from the oral cavity and frequently related to polymicrobial infections in humans. Despite reports about phenotypic differences, the genotypic variation of P. micra and its role in virulence are still not elucidated. The aim of this study was to determine the genotypic diversity of P. micra isolates obtained from the subgingival biofilm of subjects with different periodontal conditions and to correlate these findings with phenotypic traits. Three reference strains and 35 isolates of P. micro were genotyped by 16S rRNA PCR-RFLP and phenotypic traits such as collagenase production, elastolytic and hemolytic activities were evaluated. 16S rRNA PCR-RFLP showed that P. micra could be grouped into two main clusters: C1 and C2; cluster C1 harbored three genotypes (HG1259-like, HG1467-like and ICBM0583-like) while cluster C2 harbored two genotypes (ATC03270-like and ICBM036). A wide variability in collagenolytic activity intensities was observed among all isolates, while elastolytic activity was detected in only two isolates. There was an association between hemolytic activity in rabbit erythrocytes and cluster C2. There was an association between hemolytic activity in rabbit erythrocytes and cluster C1. Although these data suggest a possible association between P. micra genetic diversity and their pathogenic potential, further investigations are needed to confirm this hypothesis. (C) 2009 Elsevier Ltd. All rights reserved.

Quantitative detection of periodontopathic bacteria in atherosclerotic plaques from coronary arteries

Oral pathogens, including periodontopathic bacteria, are thought to be aetiological factors in the development of cardiovascular disease. In this study, the presence of Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum-periodonticum-simiae group, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens and Tannerella forsythia in atheromatous plaques from coronary arteries was determined by real-time PCR. Forty-four patients displaying cardiovascular disease were submitted to periodontal examination and endarterectomy of coronary arteries. Approximately 60-100 mg atherosclerotic tissue was removed surgically and DNA was obtained. Quantitative detection of periodontopathic bacteria was performed using universal and species-specific TaqMan probe/primer sets. Total bacterial and periodontopathic bacterial DNA were found in 94.9 and 92.3 %, respectively, of the atheromatous plaques from periodontitis patients, and in 80.0 and 20.0%, respectively, of atherosclerotic tissues from periodontally healthy subjects. All periodontal bacteria except for the F. nucleatum-periodonticum-simiae group were detected, and their DNA represented 47.3 % of the total bacterial DNA obtained from periodontitis; patients. Porphyromonas gingivalis, A. actinomycetemcomitans and Prevotella intermedia were detected most often. The presence of two or more periodontal species could be observed in 64.1 % of the samples. In addition, even in samples in which a single periodontal species was detected, additional unidentified microbial DNA could be observed. The significant number of periodontopathic bacterial DNA species in atherosclerotic tissue samples from patients with periodontitis suggests that the presence of these micro-organisms in coronary lesions is not coincidental and that they may in fact contribute to the development of vascular diseases.

Quantification of Porphyromonas gingivalis and fimA genotypes in smoker chronic periodontitis

Teixeira SRL, Mattarazo F, Feres M, Figueiredo LC, de Faveri M, Simionato MRL, Mayer MPA. Quantification of Porphyromonas gingivalis and fimA genotypes in smoker chronic periodontitis. J Clin Periodontol 2009; 36: 482-487. doi: 10.1111/j.1600-051X.2009.01411.x. Porphyromonas gingivalis fimA genotypes were associated with virulence factors in vitro, but little evidence of an association with disease severity were shown in humans. We aimed to correlate levels of P. gingivalis fimA genotypes II and IV and probing depth in smoker-chronic periodontitis subjects. One hundred and sixty eight subgingival samples of 20 smokers non-treated chronic periodontitis subjects obtained from sites with different probing depths [shallow (<= 3 mm), intermediate (4-6 mm), deep (>= 7 mm)] were analysed by real-time PCR for P. gingivalis and genotypes fimA II and IV. P. gingivalis and fimA IV were detected in all subjects, whereas fimA II was detected in 18 subjects (90%). One hundred and fifty two sites (90.5%) harboured P. gingivalis. Genotypes II and IV were detected in 28% and 69.6% of sites, respectively. The proportions of genotypes II and IV in relation to P. gingivalis levels were similar in shallow, intermediate and deep probing sites (2.4%, 4.6%, 1.4% for genotype II and 15.5%, 17.7%, 11.7% for genotype IV, respectively), indicating that other non-tested genotypes were more abundant. Increased levels of genotype IV were associated with increasing probing depth, but not of genotype II. The data suggested an association between P. gingivalis genotype fimA IV and disease severity in smoker-chronic periodontitis subjects.

Angiotensin II modulates CD40 expression in vascular smooth muscle cells

The signalling pathway CD40/CD40L (CD40 ligand) plays an important role in atherosclerotic plaque formation and rupture. AngII (angiotensin II), which induces oxidative stress and inflammation, is also implicated in the progression of atherosclerosis. In the present study, we tested the hypothesis that AngII increases CD40/CD40L activity in vascular cells and that ROS (reactive oxygen species) are part of the signalling cascade that controls CD40/CD40L expression. Human CASMCs (coronary artery smooth muscle cells) in culture exposed to IL (interleukin)-1 beta or TNF-alpha (tumour necrosis factor-a) had increased superoxide generation and enhanced CD40 expression, detected by EPR (electron paramagnetic resonance) and immunoblotting respectively. Both phenomena were abolished by previous incubation with membrane-permeant antioxidants or cell transfection with P22(phox) antisense. AngII (50-200 nmol/l) induced an early and sustained increase in CD40 mRNA and protein expression in CASMCs, which was blocked by treatment with antioxidants. Increased CD40 expression led to enhanced activity of the pathway, as AngII-treated cells stimulated with recombinant CD40L released higher amounts of IL-8 and had increased COX-2 (cyclo-oxygenase-2) expression. We conclude that AngII stimulation of vascular cells leads to a ROS-dependent increase in CD40/CD40L signalling pathway activity. This phenomenon may be an important mechanism modulating the arterial injury observed in atherosclerosis-related vasculopathy.

New York Trade School Administration [5]

This New York Trade School administrator is posed in front of a wall plaque dedicated to the founder of the school. Photograph is black and white.

The development of a Defense System against Coxsackievirus B5 Infection in Suckling Mice

There are many viruses that are able to infect the alimentary tract of man. Little is known, however, about the mechanism of infection itself or the pathophysiology of the gut during infection. 'The research reported here is concerned with the differences in susceptibility among suckling mice of various ages inoculated by the intraperitoneal and intragastric routes. Since the normal mode of entry of many viruses to the gut is via the oral route, Coxsackievirus B5, a human enterovirus which does attack this way, was utilized. It is a non-tumor producing RNA virus that has been shown to act similarly in the mouse and human. The virus was pooled in HeLa cell cultures and titered by a plaquing assay in the same cell cultures. CD-l mice, 10, 14, 18, and 22 days old , were infected either orally or intraperitoneally with 5.0 x 10^10 (10 day old animals) and 1.0 x10^9 plaque forming units per animal. Dissections were done at 1 and 3 days post infection with samples of the blood, heart, liver, and gut being taken from each animal. Each sample was titered individually and the data presented as an average of six samples. As a result of previous work, it is known that the gut of a newborn mouse isn't able to decrease the concentration of the infecting dose and therefore provides no defense against an enteric infection with Coxsackievirus B5. In contrat, mature mice are able to reduce the amount of viral dissemination across the gut as well as inhibit replication after absorption has occurred. The results of this study indicate that there is a double barrier system developing in suckling mice that is involved with and directly related to the gastrointestinal tract The first part of this defense is the inhibition of penetration of virus across the gut when the primary site of' infection is the intestinal mucosa. This mechanism develops sometime around 20 to 22 days after birth. At about 16-18 days of age, suckling mice that were challenged intragastrically are able to stop active replication and initiate clearance of virus from the systemic circulation. There are many factors that might contribute to the marked decrease in susceptibility with age of suckling mice. Some of these or possibly a combination of these factors might explain the defense mechanisms described above, but to date, the chemistry or mechanical functioning of the gastrointestinal barrier to enteric viral infection is unknown.

Estudo dos fatores genéticos de risco para o infarto agudo do miocárdio em idade precoce

O mecanismo patogênico mais importante no IAM é a oclusão trombótica de uma artéria coronariária no local de ruptura de uma placa aterosclerótica. Recentemente, diversos estudos têm investigado a associação entre o IAM e fatores genéticos protrombóticos. O presentetrabalho é um estudo tipo caso-controle a fim de avaliar o efeito de diversos polimorfismos genéticos em um grupo de pacientes com IAM antes dos 60 anos de idade. Foram investigados 283 pacientes e 93 indivíduos controles, todos caucasóides e sem diferenças quanto à proporção sexual e idade média entre os grupos.

Avaliação da saúde bucal e anomalias dentárias em pacientes tratados com leucemia na infância e adolescência

Objetivo: o objetivo deste estudo foi avaliar as condições de saúde bucal e a ocorrência de anomalias dentárias em crianças tratadas para leucemia linfoblástica aguda (LLA) no Serviço de Oncologia Pediátrica (SOP) do Hospital de Clínicas de Porto Alegre (HCPA), comparadas com um grupo crianças saudáveis. Amostra: foram selecionadas 56 crianças com diagnóstico de LLA e analisadas as presenças de anomalias dentárias e os índices CPO-D (cariado, perdido, obturado-dente), IPV (índice de placa visível), ISG (índice de sangramento gengival) e fluxo salivar. As crianças tratadas apresentaram uma média de idade, na época do diagnóstico da LLA, de 5,3 ± 2,6, e 11,8 ± 4,2 na avaliação, sendo 32 masculinos e 24 femininos. Os pacientes tratados para LLA foram divididos em três grupos: crianças tratadas somente com quimioterapia, com quimio e radioterapia, e com quimio, radio e transplante de medula óssea. Resultados: os resultados revelaram 80,4% de anomalias dentárias nas crianças tratadas, ou seja, 45 destas apresentaram pelo menos uma alteração, e o grupo de pacientes tratados com quimio, radio e submetidos ao transplante de medula óssea foi o que revelou a maior média de anormalidades dentárias por indivíduo (15,37 ± 15,03), não ocorrendo diferença estatística entre os gêneros. As crianças tratadas para LLA obtiveram CPO-D de 1,9 ± 4,0, ISG de 26,5%, IPV de 72,0%, e índice de fluxo salivar médio de 0,19 mL/min criança. Já o grupo de crianças sadias apresentou CPO-D de 1,52 ± 3,5, ISG de 11,1%, IPV de 53,8% e índice de fluxo salivar médio de 0,27 mL/min. Conclusão: o tratamento para a cura da LLA provoca um aumento significativo no número de anomalias dentárias, sendo mais freqüente nos pacientes menores de cinco anos de idade, principalmente nos pacientes submetidos a quimio e radioterapia associadas ao transplante de medula óssea, o que requer, por parte do cirurgião-dentista, intervenções clínicas diferenciadas e cuidadosas nestes pacientes, tendo-se em vista também os índices aumentados de ISG e IPV. As alterações sofridas pelas glândulas salivares durante o tratamento não são permanentes sob o aspecto do fluxo salivar, que retorna à normalidade. A orientação e o acompanhamento adequados destes pacientes por parte da equipe de saúde bucal podem mantê-los com o índice de CPO-D dentro dos padrões preconizados pela Organização Mundial de Saúde.

Avaliação in vitro da atividade antimicrobiana de diferentes soluções a base de hidróxido de cálcio

The science of Dentistry wishes obtains the ideal solution for the dental plaque chemical control. This research evaluated antimicrobial action capacity in calcium hydroxide and tergentol various solutions starting for the CHD 20, a root canals irrigating solution with a reason of 80% calcium hydroxide saturated solution and 20% tergentol detergent with the aim of evaluate this drug mouth rinse indication with prevention or combat objective for dental caries and periodontal diseases. Antibiogram disks and biofilm tests were accomplished for the microorganisms: Streptococcus mutans, Streptococcus sanguis, Streptococcus sobrinus and Lactobacillus casei. Different reasons of detergent for the calcium hydroxide saturated solution, tergentol and distillated water solution, 0,12% clorhexydine digluconate solution was positive control and distillated water was negative control. The results showed better performance of clorhexydine in relation to calcium hydroxide directing to not accept this (CHD20) as mouth rinse solution

Identificação e fatores de virulência de Candida spp isoladas da cavidade bucal de transplantados renais do hospital universitário Onofre Lopes em Natal-RN

Despite Candida species are often human commensals isolated from various oral sites such as: tongue, cheek and palatal mucosa plus subgingival region, there are some properties linked to the organism commonly known as virulence factors which confer them the ability to produce disease. Oral candidiasis is one of the main oral manifestations reported in literature related to kidney transplant patients. The objectives of the present study were to identify and investigate virulence factors of yeasts isolated from the oral cavity of kidney transplant recipients admitted at the Hospital Universitário Onofre Lopes, in Natal RN. Seventy Candida species isolated from 111 kidney transplant recipients were investigated in this study. Identification of the isolates was performed by using the evidence of germ tube formation, hypertonic broth, tolerance to grow at 42°C, micromorphology and biochemical profiles. We observed a high rate of isolation of yeasts from the oral cavity of kidney transplant recipients (63.1%) being C. albicans was the most prevalent species. Oral candidiasis was diagnosed in 14.4% of transplant recipients. We evaluated virulence properties of the isolates regarding to: biofilm formation on polystyrene microplates as well as XTT reduction, adherence to acrylic resin and human buccal epithelial cells and proteinase activity. Most isolates were able to form biofilm by the method of adhesion to polystyrene. All isolates of Candida spp. remained viable during biofilm formation when analyzed by the method of XTT reduction. The number of CFU attached to the acrylic resin suggested high adherence for C. parapsilosis. C. albicans isolates showed higher median adherence to human buccal epithelial cells than non-C. albicans Candida isolates. Nevertheless, this difference was not statistically significant. C. dubliniensis showed low ability to adhere to plastic and epithelial cells and biofilm formation. Proteolytic activity was observed for all the isolates investigated, including the unique isolate of C. dubliniensis. There was a statistically significant association between proteinase production and the presence of oral candidiasis. Studies related to oral candidiasis in renal transplant recipients are limited to clinical and epidemiological data, but investigations concerning Candida spp. virulence factor for this group of individuals are still scarce. We emphasize the importance of studies related to virulence factors of yeasts isolated from this population to contribute to the knowledge of microbiological aspects of oral candidiasis

In vitro and in vivo studies of the Interferon-alpha action on distinct Orthobunyavirus

Oropouche, Caraparu, Guama, Guaroa and Tacaiuma viruses (Orthobunyavirus genus) cause human febrile illnesses and/or encephalitis. To achieve a therapeutical agent to prevent and/or treat these diseases we evaluated the antiviral action of Interferon-alpha (IFN-alpha) on these orthobunyaviruses. In vitro results showed that all the studied orthobunyaviruses are susceptible to antiviral action of IFN-alpha, but this susceptibility is limited and dependent on both concentration of drug and treatment period. In vivo results demonstrated that IFN-alpha present antiviral action on Oropouche and Guaroa viruses when used as a prophylactic treatment. Moreover, a treatment initiated 3 It after infection prevented the death of Guaroa virus infected-mice. Additionally, mortality of mice was related to the migration and replication of viruses in their brains. Our results suggest that IFN-alpha could be potentially useful in the prevention of diseases caused by Oropouche virus and in the prevention and/or treatment of diseases caused by Guaroa virus. (C) 2007 Elsevier B.V. All rights reserved.

Tipo e freqüência de alterações dentárias e periodontais em cães na região de Jaboticabal, SP

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

UTILIZAÇÃO da PRÓPOLIS E ÁLCOOL ETÍLICO NO CONTROLE DE Salmonella em RAÇÕES AVÍCOLAS

Em quatro experimentos foram avaliados como agentes antibacterianos os produtos própolis em solução alcoólica e álcool etílico, adicionados às rações artificialmente contaminadas com os respectivos sorotipos: Salmonella typhimurium Nalr - Specr, (resistentes ao ácido Nalidíxico e a Spectinomicina) nos três primeiros experimentos e Salmonella agona Nalr - Specr, Salmonella infantis Nalr - Specr e Salmonella enteritidis Nalr - Specr no quarto experimento. As rações foram fornecidas a grupos de 10-16 pintos de corte de um dia. em todos os experimentos os produtos testados foram adicionados na base de 2% da ração. Quando se utilizou solução hidroalcóolica de própolis (exp. 1), seguidas 120 horas após o desafio, detectou-se a presença da bactéria nos cecos. No segundo experimento, testou-se a solução de própolis e seu diluente, o álcool etílico; seguidas 96 horas após o desafio, não foi observada a presença da bactéria nos cecos (< 2,0 log10). Avaliou-se, no terceiro experimento, a ação da solução de própolis e do álcool etílico no tempo, adicionados na ração 14 dias e 28 dias antes do fornecimento às aves. Após 72 horas do desafio, a leitura nas placas acusou a presença da bactéria nos cecos. Dentro deste último período, também se avaliou a ação da própolis em pó (extrato seco) e esse mesmo extrato em uma solução aquosa, adicionados à ração 48 horas antes do fornecimento às aves sendo que os resultados confirmaram a presença da bactéria nos cecos. No quarto experimento avaliou-se somente o álcool etílico nas rações artificialmente contaminadas com os sorotipos S. agona, S. enteritidis e S. infantis, registrando-se contagem zero (<2,0 log10) apenas com o último sorotipo. Os resultados obtidos permitem concluir que o tratamento com a solução de própolis apresentou ação sobre a S. typhimurium somente quando em solução alcóolica, dentro de um período de 48 horas, indicando que o efeito bactericida se deveu ao álcool etílico presente na solução. A ação do tratamento com o álcool etílico sobre os demais sorotipos demonstrou resultado parcial sendo observado efeito bactericida nos sorotipos S. typhimurium e S. enteritidis artificialmente inoculados na ração.

A new method to quantify macroalgae and a practical sampler for experimentation in lotic habitats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)