Menopausa: fator de risco para doença periodontal?

OBJETIVO: verificar se existe relação entre os parâmetros periodontais e os níveis de estrógeno e densitometria óssea mineral (DOM). MÉTODOS: foram avaliadas 46 mulheres na pós-menopausa entre 44 e 68 anos de idade (52,2±4,8) e 15 mulheres como grupo controle entre 35 e 54 anos de idade (44,7±7,5). Parâmetros periodontais como profundidade à sondagem (PS), perda de inserção clínica (PIC) e dentes ausentes (DA) foram comparados com os níveis de estrógeno (suficiente e deficiente) e DOM em normais, osteopênicas e osteoporóticas. Os dados foram comparados pela diferença das médias entre os grupos e analisados pelo teste de Aspin-Welch. RESULTADOS: as médias dos parâmetros de PS, PIC e DA, quando associados ao grau da DOM em normais (2,1±0,5; 2,9±1,4 e 10,6±5,0), osteopênicas (2,3±0,7; 3,0±1,1 e 12,8±5,1) e osteoporóticas (2,4±0,6; 2,7±0,9 e 14,3±5,7), não mostraram diferenças significativas (p>0,05). Foi encontrada diferença significante entre o grupo controle e nas mulheres menopausadas para PIC e DA. Quando comparados com os níveis de estrógeno os resultados demonstraram igualdade para os parâmetros periodontais. CONCLUSÕES: apesar de alguns estudos demonstrarem correlação positiva da doença periodontal com osteoporose e com os níveis de estrogênio, na população de mulheres menopausadas estes dados não foram confirmados neste estudo.

Doença periodontal e complicações obstétricas: há relação de risco?

Estudos têm apontado possíveis relações de risco existentes entre doenças bucais, principalmente a doença periodontal, e complicações gestacionais, como parto prematuro, nascimento de recém-nascidos de baixo peso e pré-eclâmpsia. As explicações para tais hipóteses baseiam-se no fato de a doença periodontal ser de origem infecciosa, o que poderia provocar aumento de citocinas inflamatórias no sangue materno, por liberação direta da bolsa periodontal ou por disseminação de bactérias patogênicas, induzindo sua produção sistêmica. Esta suposição fundamenta-se no conhecimento de que a fisiopatologia das complicações obstétricas citadas está associada à presença de algumas citocinas no sangue materno. O presente trabalho teve como objetivo realizar revisão da literatura em busca de evidências para estas supostas associações. Apesar do grande número de estudos clínicos encontrados nesta revisão, observa-se a falta de padronização metodológica dos mesmos, fato que limita conclusões definitivas a respeito. Por outro lado, o fato de a doença periodontal ainda não ser comprovadamente um fator de risco para as complicações obstétricas não diminui a importância da manutenção da saúde bucal das gestantes, que devem apresentar condições orais que propiciem adequada alimentação, sem dor e sangramento, e assim manter seu aporte nutricional adequado.

Associação entre osteoporose e doença periodontal em mulheres na pós-menopausa

OBJETIVO: o objetivo desse estudo foi verificar a associação entre a osteoporose e a doença periodontal. MÉTODOS: foram incluídas 39 mulheres na pós-menopausa, que foram divididas em três grupos conforme categorização da massa óssea, por meio da avaliação da densidade mineral óssea, aferida pela absormetria de dupla emissão com raios X na área lombar (L1-L4): osso normal, osteopenia e osteoporose. Foi aplicado o índice de nível de inserção clínica (NIC) para todas as participantes no início da pesquisa e após um ano, por apenas um examinador. Os dados da situação periodontal foram submetidos à análise estatística com o teste t de Student pareado. RESULTADOS: o exame periodontal revelou que as mulheres na pós-menopausa com osteopenia apresentaram menor média do NIC no exame clínico periodontal inicial (2,1±1,1 mm), enquanto as pertencentes ao grupo osso normal mostraram menor perda dos tecidos de sustentação dos dentes após um ano (3,1±1,6 mm). Após a realização do tratamento estatístico, observou-se que não houve diferença significativa para a situação periodontal no osso normal, entretanto foi constatada diferença estatística nas pacientes do osteopenia e osteoporose, quando comparados os valores do NIC, nos dois períodos de avaliação. CONCLUSÕES: conclui-se que a osteoporose na pós-menopausa pode ser considerada como possível fator de risco para a doença periodontal.

Doença periodontal em mulheres na pós-menopausa e sua relação com a osteoporose

OBJETIVO: Verificar a relação entre periodontite e osteoporose em um estudo caso-controle sobre a condição periodontal das mulheres na pós-menopausa. MÉTODOS: A amostra foi composta por 99 mulheres na pós-menopausa, divididas em três grupos: osso normal (Gn), osteopenia (Gpenia) e osteoporose (Gporose), com 45, 31 e 23 casos, respectivamente. A categorização da massa óssea foi aferida pela absorciometria de dupla emissão com raios X na área lombar (L2 - L4), e pela avaliação da densidade mineral óssea. Os índices de nível de inserção clínica (NIC), sangramento gengival (IG), de placa (IP) e profundidade de sondagem (PS) foram obtidos de todas as participantes, por apenas um examinador. Foi utilizado o programa BioEstat 2.0 para análise dos dados com os testes paramétricos análise de variância (ANOVA) e teste de Bonferroni, empregando-se o nível de significância de 5%. RESULTADOS: O grupo de mulheres com osteoporose apresentou o maior percentual de presença da doença periodontal, com maior média do NIC (2,6±0,4 mm), assim como PS (2,8±0,6 mm), IG (72,8±25,9 mm) e IP (72,9±24,2 mm). Após a realização do tratamento estatístico, observou-se que houve diferença significativa para a situação periodontal, principalmente entre os grupos Gn e Gporose (p=0,01) e entre os grupos Gpenia e Gporose (p=0,03). CONCLUSÃO: A osteoporose pode ter uma influência na condição periodontal, por haver relação entre periodontite e osteoporose em mulheres na pós-menopausa.

Adherence and experimental infection of bacteria associated with periodontal infections of young cattle in Brazil ("Cara inchada")

In vitro- and in vivo-assays were conducted, to study the possible role of streptomycin- and actinomycin-producing soil actinomycetes for the pathogenesis of "Cara inchada" in cattle (CI). Adherence of Bacteroides spp. to epithelial cells of the bovine gingiva, known to be associated with the progressive lesions of CI, was significantly increased by the addition of streptomycin, actinomycin or antibiotic culture supernatants of the soil actinomycetes. Applications of these mixtures together with Actinomyces pyogenes to the marginal gingiva of the upper premolar teeth of about 1 month old Holstein Friesian calves did not lead to progressive lesions of CI. Only one calf exhibited a slight diarrhea and a temporary retraction of the gingiva at the site of application.

Estudo comparativo sobre prevalência de doença periodontal em Panthera onca mantida em cativeiro e em indivíduos de natureza

Objetivou-se fazer levantamento das principais afecções de cavidade oral relacionadas com a doença perio-dontal em Panthera onca proveniente de cativeiro e natureza. Sob o ponto de vista da conservação de animais ameaçados de extinção, no caso a onça-pintada (Panthera onca), buscou-se promover a orientação dos proprietários e trabalhadores rurais sobre a necessidade da preservação de tal espécie em vida livre e tentar determinar se as condições ambientais podem influenciar na saúde oral. Utilizou-se amostra constituída de 42 onças-pintadas (P. onca), provenientes de 18 instituições mantenedoras de tais espécies em cativeiro no Estado de São Paulo, que foram visitadas e anestesiadas pelo Plano de Manejo de Felinos Neotropicais. Pesquisaram-se também 4 onças-pintadas (P. onca), provenientes de vida livre, capturados na Fazenda Sete, município de Miranda, Estado do Mato Grosso do Sul, no pantanal sul mato-grossense. Todos os animais pesquisados em cativeiro apresentaram graus variados de lesões orais relacionadas à doença periodontal. Aqueles animais pesquisados na natureza não apresentaram nenhum tipo de comprometimento clínico na cavidade oral.

Evaluation of a model for induction of periodontal disease in dogs

There are several methods for inducing periodontal disease in animal models, being the bone defect one of the most reported. This study aimed to evaluate this model, through clinical, radiographic, tomographic and histological analyzes, thus providing standardized data for future regenerative works. Twelve dogs were subjected to the induction protocol. In a first surgical procedure, a mucoperiosteal flap was made on the buccal aspect of the right third and fourth premolars and a defect was produced exposing the furcation and mesial and distal roots, with dimensions: 5mm coronoapical, 5mm mesiodistal, and 3mm buccolingual. Periodontal ligament and cementum were curetted and the defect was filled with molding polyester, which was removed after 21 days on new surgical procedure. Clinical and radiographic examinations were performed after the two surgeries and before the collection of parts for dental tomography and histological analysis. All animals showed grade II furcation exposure in both teeth. Clinical attachment level increased after induction. Defect size did not change for coronoapical and buccolingual measurements, while mesiodistal size was significantly higher than at the time of defect production. Radiographic analysis showed decreased radiopacity and discontinuity of lamina dura in every tooth in the furcation area. The horizontal progression of the disease was evident in micro-computed tomography and defect content in the histological analysis. Therefore, it is concluded that this method promotes the induction of periodontal disease in dogs in a standardized way, thus being a good model for future work.

Protein folding: a perspective for biology, medicine and biotechnology

At the present time, protein folding is an extremely active field of research including aspects of biology, chemistry, biochemistry, computer science and physics. The fundamental principles have practical applications in the exploitation of the advances in genome research, in the understanding of different pathologies and in the design of novel proteins with special functions. Although the detailed mechanisms of folding are not completely known, significant advances have been made in the understanding of this complex process through both experimental and theoretical approaches. In this review, the evolution of concepts from Anfinsen's postulate to the "new view" emphasizing the concept of the energy landscape of folding is presented. The main rules of protein folding have been established from in vitro experiments. It has been long accepted that the in vitro refolding process is a good model for understanding the mechanisms by which a nascent polypeptide chain reaches its native conformation in the cellular environment. Indeed, many denatured proteins, even those whose disulfide bridges have been disrupted, are able to refold spontaneously. Although this assumption was challenged by the discovery of molecular chaperones, from the amount of both structural and functional information now available, it has been clearly established that the main rules of protein folding deduced from in vitro experiments are also valid in the cellular environment. This modern view of protein folding permits a better understanding of the aggregation processes that play a role in several pathologies, including those induced by prions and Alzheimer's disease. Drug design and de novo protein design with the aim of creating proteins with novel functions by application of protein folding rules are making significant progress and offer perspectives for practical applications in the development of pharmaceuticals and medical diagnostics.

Antioxidant properties of natural compounds used in popular medicine for gastric ulcers

There is evidence concerning the participation of reactive oxygen species in the etiology and physiopathology of human diseases, such as neurodegenerative disorders, inflammation, viral infections, autoimmune pathologies, and digestive system disorders such as gastrointestinal inflammation and gastric ulcer. The role of these reactive oxygen species in several diseases and the potential antioxidant protective effect of natural compounds on affected tissues are topics of high current interest. To consider a natural compound or a drug as an antioxidant substance it is necessary to investigate its antioxidant properties in vitro and then to evaluate its antioxidant functions in biological systems. In this review article, we shall consider the role of natural antioxidants derived from popular plants to reduce or prevent the oxidative stress in gastric ulcer induced by ethanol.

Repercussions of a sleep medicine outreach program

Despite the high prevalence of sleep disorders, many healthcare professionals and lay people have little knowledge of Sleep Medicine. Mindful of such a reality, in 2001 the Sleep Institute of the Associação Fundo de Incentivo à Psicofarmacologia launched a campaign to increase Sleep Medicine awareness. Media features, exhibitions, inserts, and classes were used to reach 2,000,000 people and 55,000 healthcare professionals during the period from 2001 to 2004. To evaluate this program, we compared data for polysomnography referrals to the Institute in 2000 and in 2004. A total of 8805 referrals were evaluated (2000: 2164; 2004: 6641). Over the 4 years of the program, the number of beds increased by 43%; more women were referred (31 vs 37%; P < 0.001), mainly with a diagnostic hypothesis of sleep-disorder breathing (SDB). SDB was the most frequent diagnostic hypothesis in 2000 and 2004. In 2004 there were fewer referrals without a diagnostic hypothesis (27 vs 21%; P < 0.001) and for controlling surgically treated SDB (2.3 vs 1.6%; P < 0.05), and an increase in the following diagnostic hypotheses: non-invasive treatment of SDB (8.3 vs 12.3%; P < 0.001) and insomnia (3.5 vs 6.5%; P < 0.001). Insomnia diagnostic hypothesis was better correlated with SDB on referral documents in 2004 and less with a diagnostic hypothesis of limb movement disturbance. The program helped increase polysomnography referrals, particularly among women. Healthcare professionals appear to have a more developed understanding of sleep disorders.

Antimicrobial activity of the essential oil from Lippia sidoides, carvacrol and thymol against oral pathogens

Dental caries and periodontal disease are associated with oral pathogens. Several plant derivatives have been evaluated with respect to their antimicrobial effects against such pathogenic microorganisms. Lippia sidoides Cham (Verbenaceae), popularly known as "Alecrim-pimenta" is a typical shrub commonly found in the Northeast of Brazil. Many plant species belonging to the genus Lippia yield very fragrant essential oils of potential economic value which are used by the industry for the commercial production of perfumes, creams, lotions, and deodorants. Since the leaves of L. sidoides are also extensively used in popular medicine for the treatment of skin wounds and cuts, the objective of the present study was to evaluate the composition and antimicrobial activity of L. sidoides essential oil. The essential oil was obtained by hydro-distillation and analyzed by GC-MS. Twelve compounds were characterized, having as major constituents thymol (56.7%) and carvacrol (16.7%). The antimicrobial activity of the oil and the major components was tested against cariogenic bacterial species of the genus Streptococcus as well as Candida albicans using the broth dilution and disk diffusion assays. The essential oil and its major components thymol and carvacrol exhibited potent antimicrobial activity against the organisms tested with minimum inhibitory concentrations ranging from 0.625 to 10.0 mg/mL. The most sensitive microorganisms were C. albicans and Streptococcus mutans. The essential oil of L. sidoides and its major components exert promising antimicrobial effects against oral pathogens and suggest its likely usefulness to combat oral microbial growth.

Evaluation of cardiovascular toxicity of carbon nanotubes functionalized with sodium hyaluronate in oral regenerative medicine

It has been demonstrated that carbon nanotubes (CNTs) associated with sodium hyaluronate (HY-CNTs) accelerate bone repair in the tooth sockets of rats. Before clinical application of HY-CNTs, it is important to assess their biocompatibility. Moreover, cardiac toxicity may be caused by the translocation of these particles to the blood stream. The aim of this study was to evaluate possible changes in cardiovascular function in male Wistar rats whose tooth sockets were treated with either CNTs or HY-CNTs (100 μg/mL, 0.1 mL). Blood pressure and heart rate were monitored in conscious rats 7 days after treatment. Cardiac function was evaluated using the Langendorff perfusion technique. The data showed no changes in blood pressure or heart rate in rats treated with either CNTs or HY-CNTs, and no significant changes in cardiac function were found in any of the groups. To confirm these findings, experiments were conducted in rats injected intraperitoneally with a high concentration of either CNTs or HY-CNTs (0.75 mg/kg). The same parameters were analyzed and similar results were observed. The results obtained 7 days following injection indicate that the administration of low concentrations of CNTs or HY-CNTs directly into tooth sockets did not cause any significant change in cardiovascular function in the rats. The present findings support the possibility of using these biocomposites in humans.

Advanced glycation end products (AGEs) and their receptor (RAGE) induce apoptosis of periodontal ligament fibroblasts

Diabetics have an increased prevalence of periodontitis, and diabetes is one of the causative factors of severe periodontitis. Apoptosis is thought to be involved in this pathogenic relationship. The aim of this study was to investigate apoptosis in human periodontal ligament (PDL) fibroblasts induced by advanced glycation end products (AGEs) and their receptor (RAGE). We examined the roles of apoptosis, AGEs, and RAGE during periodontitis in diabetes mellitus using cultured PDL fibroblasts that were treated by AGE-modified bovine serum albumin (AGE-BSA), bovine serum albumin (BSA) alone, or given no treatment (control). Microscopy and real-time quantitative PCR indicated that PDL fibroblasts treated with AGE-BSA were deformed and expressed higher levels of RAGE and caspase 3. Cell viability assays and flow cytometry indicated that AGE-BSA reduced cell viability (69.80±5.50%, P<0.01) and increased apoptosis (11.31±1.73%, P<0.05). Hoechst 33258 staining and terminal-deoxynucleotidyl transferase-mediated nick-end labeling revealed that AGE-BSA significantly increased apoptosis of PDL fibroblasts. The results showed that the changes in PDL fibroblasts induced by AGE-BSA may explain how AGE-RAGE participates in and exacerbates periodontium destruction.

Effects of IL-10 and glucose on expression of OPG and RANKL in human periodontal ligament fibroblasts

The effects of interleukin-10 (IL-10) and glucose on mRNA and protein expression of osteoprotegerin (OPG), and its ligand, receptor activator of nuclear factor-κB ligand (RANKL), were investigated in human periodontal ligament fibroblasts (HPDLFs). Primary HPDLFs were treated with different concentrations of IL-10 (0, 1, 10, 25, 50, and 100 ng/mL) or glucose (0, 5.5, 10, 20, 30, and 40 mmol/L). Changes in mRNA and protein expression were examined using the reverse-transcription polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. After IL-10 treatment, mRNA and protein levels of OPG were increased, while mRNA and protein levels of RANKL were decreased (P<0.05), both in a concentration-dependent manner. Glucose stimulation had the opposite concentration-dependent effect to that of IL-10 on OPG and RANKL expression. IL-10 upregulated OPG expression and downregulated RANKL expression, whereas high glucose upregulated RANKL and downregulated OPG in HDPLFs. Abnormal levels of IL-10 and glucose may contribute to the pathogenesis of periodontal disease.