RESUMO
BACKGROUND AND OBJECTIVE: Soluble epoxide hydrolase (sEH) is an enzyme in the arachidonate cascade which converts epoxy fatty acids (EpFAs), such as epoxyeicosatrienoic acids (EETs) produced by cytochrome P450 enzymes, to dihydroxy-eicosatrienoic acids. In the last 20 years with the development of inhibitors to sEH it has been possible to increase the levels of EETs and other EpFAs in in vivo models. Recently, studies have shown that EETs play a key role in blocking inflammation in a bone resorption process, but the mechanism is not clear. In the current study we used the sEH inhibitor (1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea [TPPU]) to investigate the immunomodulatory effects in a mouse periodontitis model. MATERIAL AND METHODS: Mice were infected on days 0, 2, and 4 with Aggregatibacter actinomycetemcomitans and divided into groups (n = 6) that were treated orally, daily for 15 days, with 1 mg/kg of TPPU. Then, the mice were killed and their jaws were analyzed for bone resorption using morphometry. Immunoinflammatory markers in the gingival tissue were analyzed by microarray PCR or western blotting. RESULTS: Infected mice treated with TPPU showed lower bone resorption than infected mice without treatment. Interestingly, infected mice showed increased expression of sEH; however, mice treated with TPPU had a reduction in expression of sEH. Besides, several proinflammatory cytokines and molecular markers were downregulated in the gingival tissue in the group treated with 1 mg/kg of TPPU. CONCLUSION: The sEH inhibitor, TPPU, showed immunomodulatory effects, decreasing bone resorption and inflammatory responses in a bone resorption mouse model.
Assuntos
Reabsorção Óssea/imunologia , Reabsorção Óssea/prevenção & controle , Inibidores Enzimáticos/farmacologia , Epóxido Hidrolases/antagonistas & inibidores , Epóxido Hidrolases/fisiologia , Imunomodulação/efeitos dos fármacos , Periodontite/imunologia , Periodontite/metabolismo , Compostos de Fenilureia/farmacologia , Piperidinas/farmacologia , Administração Oral , Animais , Citocinas/metabolismo , Modelos Animais de Doenças , Inibidores Enzimáticos/administração & dosagem , Epóxido Hidrolases/metabolismo , Gengiva/metabolismo , Mediadores da Inflamação/metabolismo , Masculino , Camundongos , Compostos de Fenilureia/administração & dosagem , Piperidinas/administração & dosagemRESUMO
AIM: To evaluate the mechanical behaviour of the dentine/cement/post interface of a maxillary central incisor using the finite element method and to compare the stresses exerted using conventional or customized post cementation techniques. METHODOLOGY: Four models of a maxillary central incisor were created using fibreglass posts cemented with several techniques: FGP1, a 1-mm-diameter conventionally cemented post; CFGP1, a 1-mm-diameter customized composite resin post; FGP2, a 2-mm-diameter conventionally cemented post; CFGP2, a 2-mm-diameter customized composite resin post. A distributed load of 1N was applied to the lingual aspect of the tooth at 45° to its long axis. Additionally, polymerization shrinkage of 1% was simulated for the resin cement. The surface of the periodontal ligament was fixed in the three axes (X =Y = Z = 0). The maximum principal stress (σ(max) ), minimum principal stress (σ(min)), equivalent von Mises stress (σ(vM) ) and shear stress (σ(shear)) were calculated for the dentine/cement/post interface using finite element software. RESULTS: The peak of σ(max) for the cement layer occurred first in CFGP1 (1.77 MPa), followed by CFGP2 (0.99), FGP2 (0.44) and FGP1 (0.2). The shrinkage stress (σ(vM) ) of the cement layer occurred as follows: FGP1 (35 MPa), FGP2 (34), CFGP1 (30.7) and CFGP2 (30.1). CONCLUSIONS: Under incisal loading, the cement layer of customized posts had higher stress concentrations. The conventional posts showed higher stress because of polymerization shrinkage.
Assuntos
Resinas Compostas/química , Materiais Dentários/química , Planejamento de Prótese Dentária , Cavidade Pulpar/ultraestrutura , Dentina/ultraestrutura , Vidro/química , Incisivo/ultraestrutura , Técnica para Retentor Intrarradicular/instrumentação , Cimentos de Resina/química , Fenômenos Biomecânicos , Cimentação/métodos , Simulação por Computador , Módulo de Elasticidade , Análise de Elementos Finitos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Teste de Materiais , Modelos Biológicos , Ligamento Periodontal/fisiologia , Polimerização , Resistência ao Cisalhamento , Estresse Mecânico , Propriedades de Superfície , Microtomografia por Raio-X/métodosRESUMO
The aim of this study was to compare the stress distribution induced by posterior functional loads on conventional complete dentures and implant-retained overdentures with different attachment systems using a two-dimentional Finite Element Analysis (FEA-2D). Three models representative of edentulous mandible were constructed on AutoCAD software; Group A (control), a model of edentulous mandible supporting a complete denture; Group B, a model of edentulous mandible supporting an overdenture over two splinted implants connected with the bar-clip system; Group C, a model of edentulous mandible supporting an overdenture over two unsplinted implants with the O-ring system. Evaluation was conducted on Ansys software, with a vertical force of 100 N applied on the mandibular left first molar. When the stress was evaluated in supporting tissues, groups B (51.0 MPa) and C (52.6 MPa) demonstrated higher stress values than group A (10.1 MPa). Within the limits of this study, it may be concluded that the use of an attachment system increased stress values; furthermore, the use of splinted implants associated with the bar-clip attachment system favoured a lower stress distribution over the supporting tissue than the unsplinted implants with an O-ring abutment to retain the mandibular overdenture.
Assuntos
Prótese Dentária Fixada por Implante , Prótese Total , Revestimento de Dentadura , Análise do Estresse Dentário/métodos , Planejamento de Dentadura , Retenção de Dentadura/métodos , Humanos , Teste de Materiais/métodos , Modelos Anatômicos , Estresse MecânicoRESUMO
Some studies have evaluated the salivary levels of mutans streptococci (MS) in removable partial denture (RPD) users. Saliva samples (2.0 mL) were obtained from 31 patients in six periods: (T0): immediately before installation of RPD; (T8): 8 days after T0; (T48): 48 days after T0; (T92): 92 days after T0; (T140): 140 days after T0 and (T189): 189 days after T0. The samples were vortexed and serially diluted from 10(-1) to 10(-6) in 0.05 m phosphate buffer (pH 7.4). From each dilution, 0.025 mL was plated on Mitis Salivarius Bacitracin (MSB). The plates were incubated in 5% CO2 at 37 degrees C for 72 h. There was an increase (t-test, P < 0.05) in the number of MS between periods T0 and T48 (mean/s.d., CFU mL(-1) of saliva): T0: 2.26/4.43 x 10(6) and T48: 0.47/1.48 x 10(8). After this, intensive treatment with CHX was accomplished in 29 patients. Saliva samples were obtained after treatment in four periods: (T24 h): 24 h after T0; (T14): 14 days after T24 h; (T28): 28 days after T24 h, and (T63): 63 days after T24 h. The number of MS in saliva did not decrease (t-test, P > 0.05). A new CHX formulation was applied in 15 patients. Saliva samples were obtained in periods: (T0): before new CHX application; (T24 h): 24 h after T0 and (T82): 82 days after T0. The new CHX reduced MS levels in saliva: (mean/s.d., CFU mL(-1) of saliva): T0: 6.64/8.47 x 10(6) and T24 h: 3.2/4.27 x 10(5) (sign rank, P < 0.05). In conclusion, there was a significant increase in the number of MS in saliva after the installation of RPD. The intensive treatment with a properly formulated CHX was effective in the reduction of MS, between 24 h and 82 days after its application.
Assuntos
Clorexidina/uso terapêutico , Prótese Parcial Removível , Antissépticos Bucais/uso terapêutico , Saliva/microbiologia , Streptococcus mutans , Contagem de Colônia Microbiana , Prótese Parcial Removível/microbiologia , Humanos , Estudos LongitudinaisRESUMO
BACKGROUND: Tracheostomy in children remains controversial regarding the risk of complications. METHODS: Forty-six trauma patients (35 male and 11 female, mean age = 6.8 years) were admitted to the intensive care unit between 1987 and 1991 with severe head injury plus coma. Tracheostomy was performed with standard technique after 5.9 days (range, 2-12 days) of intubation. RESULTS: There were no deaths from tracheostomy, but six deaths resulted from severe head injury. One child was discharged with tracheostomy. The 39 survivors remained with tracheostomy 16.14 days (range, 4-71 days) in the intensive care unit. After cannula removal, 31 remained asymptomatic; 8 had respiratory distress: 2 were normal, 5 had endoscopic treatment for subglottic granulomas/stenosis from intubation, and 1 had tracheomalacia from tracheostomy. In 1997, the 18 patients located for follow-up were asymptomatic. At endoscopy, 8 were normal, 9 had subglottal granulomas from intubation, and 1 had 20% tracheal stenosis from tracheostomy. CONCLUSION: Most complications after tracheostomy result from intubation. Tracheostomy has an acceptable risk in children with severe head injury who need prolonged ventilatory support.
Assuntos
Coma Pós-Traumatismo da Cabeça/terapia , Traumatismos Craniocerebrais/terapia , Serviços Médicos de Emergência , Complicações Pós-Operatórias , Traqueostomia/efeitos adversos , Adolescente , Criança , Pré-Escolar , Coma Pós-Traumatismo da Cabeça/complicações , Traumatismos Craniocerebrais/complicações , Feminino , Seguimentos , Humanos , Masculino , Fatores de RiscoRESUMO
Although chlorhexidine is the most effective agent against dental plaque it is extremely bitter. To prepare formulations, it is necessary to use flavoring and sweetening, which can inhibit the antibacterial effect of chlorhexidine. Saccharin has been considered a compatible substance to use in chlorhexidine rinse or gel preparations; however, the effect of a range of concentrations has not been studied. To evaluate the effect of different concentrations of saccharin on the antibacterial activity of chlorhexidine gel, hydroxy-ethyl-cellulose gels containing 1.0% chlorhexidine digluconate and 0.0 to 1.0% sodium saccharin were prepared. Activity against Streptococcus mutans was evaluated using the agar diffusion method and determination of MIC values. The inhibitory zones of growth were 7.83 +/- 0.54 mm when no saccharin was added to the chlorhexidine gel and 7.75 +/- 0.50, 7.63 +/- 0.48, 6.21 +/- 0.40, 4.13 +/- 0.38, when the concentrations of saccharin in the gels were 0.02, 0.10, 0.5, and 1.0%, respectively. The range of MIC values was 1-2 micrograms/ml, with saccharin concentrations of 0%, 0.02, and 0.1%. In contrast, the MIC values were 4-8 and 8-16 micrograms/ml with saccharin concentrations of 0.5% and 1.0%, respectively. The paired "t" test showed that 0.5 and 1.0% sodium saccharin inhibit the antibacterial activity of 1% digluconate chlorhexidine gel. These in vitro results suggest that saccharin may inhibit the efficacy of chlorhexidine against mutans streptococci, depending on the concentration.
Assuntos
Anti-Infecciosos Locais/farmacologia , Clorexidina/análogos & derivados , Clorexidina/farmacologia , Aromatizantes/farmacologia , Sacarina/farmacologia , Streptococcus mutans/efeitos dos fármacos , Edulcorantes/farmacologia , Anti-Infecciosos Locais/química , Química Farmacêutica , Clorexidina/química , Contagem de Colônia Microbiana , Placa Dentária/microbiologia , Placa Dentária/prevenção & controle , Difusão , Relação Dose-Resposta a Droga , Aromatizantes/administração & dosagem , Aromatizantes/química , Géis , Humanos , Sacarina/administração & dosagem , Sacarina/química , Estatística como Assunto , Streptococcus mutans/crescimento & desenvolvimento , Edulcorantes/administração & dosagem , Edulcorantes/químicaRESUMO
Case report on right branch block, acute pulmonary oedema and enteritis caused by electric shock in a boy. The invasive hemodynamic study showed primary pulmonary hypertension, cardiogenic shock, and acute respiratory failure. The outcome was good, with total and progressive recovery of all lesions. The literature review revealed the rarity of pulmonary oedema and enteritis after an electric shock. The invasive haemodynamic data suggest physiopathological explanations for findings in the case and indicate therapeutic measures for similar situations.
Assuntos
Humanos , Masculino , Criança , Edema Pulmonar , Bloqueio de Ramo , Traumatismos por Eletricidade , Edema Pulmonar , Bloqueio de Ramo , Traumatismos por Eletricidade , Eletrocardiografia , Consumo de Oxigênio , HemodinâmicaRESUMO
Case report on right branch block, acute pulmonary oedema and enteritis caused by electric shock in a boy. The invasive hemodynamic study showed primary pulmonary hypertension, cardiogenic shock, and acute respiratory failure. The outcome was good, with total and progressive recovery of all lesions. The literature review revealed the rarity of pulmonary oedema and enteritis after an electric shock. The invasive haemodynamic data suggest physiopathological explanations for findings in the case and indicate therapeutic measures for similar situations.