Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Braz. j. biol ; 77(1): 79-82, Jan-Mar. 2017. graf
Artigo em Inglês | LILACS | ID: biblio-839162

RESUMO

Abstract Up until now, there have been few studies of the helminth fauna of Brazilian populations of Pogonias cromis. In North America, P. cromis is known to be a definitive host of Cotylogaster basiri, although there have been no reports of any species of Cotylogaster infecting fish in Brazil. During necropsies of marine fish obtained from professional fisherman in the state of Rio Grande do Sul, Brazil, specimens of C. basiri were found in the intestine and rectum of P. cromis. In comparison with previous studies, differences were found in relation to the number of lobes in the buccal disc and the development of the biocellate larvae in the eggs of C. basiri. This is the first report of C. basiri in P. cromis from Brazil, contributing to the understanding of the helminth fauna of this fish from the coastal zone of Brazil.


Resumo Até a presente data, existem poucos estudos sobre a helmintofauna de Pogonias cromis para o Brasil. Na América do Norte, P. cromis foi registrada como hospedeira de Cotylogaster basiri e, até o presente momento, não existem registros de qualquer espécie de Cotylogaster em peixes no Brasil. Em necropsias de peixes marinhos adquiridos por pescadores profissionais, foram encontrados espécimes de C. basiri no intestino e reto de P. cromis no Estado do Rio Grande do Sul, Brasil. Quando comparada com a literatura, foram encontradas diferenças em relação ao número de lobos do funil oral e ao desenvolvimento da larva biocelar dentro dos ovos de C. basiri. Este é o primeiro registro de C. basiri em P. cromis para o Brasil, contribuindo para o conhecimento da helmintofauna desse peixe na costa brasileira.


Assuntos
Animais , Infecções por Trematódeos/parasitologia , Perciformes/parasitologia , Brasil
2.
Braz J Biol ; 0: 0, 2016 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-27409226

RESUMO

Up until now, there have been few studies of the helminth fauna of Brazilian populations of Pogonias cromis. In North America, P. cromis is known to be a definitive host of Cotylogaster basiri, although there have been no reports of any species of Cotylogaster infecting fish in Brazil. During necropsies of marine fish obtained from professional fisherman in the state of Rio Grande do Sul, Brazil, specimens of C. basiri were found in the intestine and rectum of P. cromis. In comparison with previous studies, differences were found in relation to the number of lobes in the buccal disc and the development of the biocellate larvae in the eggs of C. basiri. This is the first report of C. basiri in P. cromis from Brazil, contributing to the understanding of the helminth fauna of this fish from the coastal zone of Brazil.


Assuntos
Perciformes/parasitologia , Infecções por Trematódeos/parasitologia , Animais , Brasil
3.
Phys Rev Lett ; 116(4): 044101, 2016 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-26871335

RESUMO

Phase-control techniques of chaos aim to extract periodic behaviors from chaotic systems by applying weak harmonic perturbations with a suitably chosen phase. However, little is known about the best strategy for selecting adequate perturbations to reach desired states. Here we use experimental measures and numerical simulations to assess the benefits of controlling individually the three terms of a Duffing oscillator. Using a real-time analog indicator able to discriminate on-the-fly periodic behaviors from chaos, we reconstruct experimentally the phase versus perturbation strength stability areas when periodic perturbations are applied to different terms governing the oscillator. We verify the system to be more sensitive to perturbations applied to the quadratic term of the double-well Duffing oscillator and to the quartic term of the single-well Duffing oscillator.

4.
Oncogene ; 32(19): 2463-74, 2013 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-22751112

RESUMO

Truncated-ERBB2 isoforms (t-ERBB2s), resulting from receptor proteolysis or alternative translation of the ERBB2 mRNA, exist in a subset of human breast tumors. t-ERBB2s lack the receptor extracellular domain targeted by therapeutic anti-ERBB2 antibodies and antibody-drug conjugates, including trastuzumab, trastuzumab-DM1 and pertuzumab. In clinical studies, expression of t-ERBB2 in breast tumors correlates with metastasis as well as trastuzumab resistance. By using a novel immuno-microarray method, we detect a significant t-ERBB2 fraction in 18 of 31 (58%) of immunohistochemistry (IHC)3+ ERBB2+ human tumor specimens, and further show that t-ERBB2 isoforms are phosphorylated in a subset of IHC3+ samples (10 of 31, 32%). We investigated t-ERBB2 biological activity via engineered expression of full-length and truncated ERBB2 isoforms in human mammary epithelial cells (HMECs), including HMEC and MCF10A cells. Expression of p110 t-ERBB2, but not p95m (m=membrane, also 648CTF) or intracellular ERBB2s, significantly enhanced cell migration and invasion in multiple cell types. In addition, only expression of the p110 isoform led to human breast epithelial cell (HMLE) xenograft formation in vivo. Expression of t-ERBB2s did not result in hyperactivation of the phosphoinositide kinase-3/AKT or mitogen-activated protein kinase signaling pathways in these cells; rather, phosphoproteomic array profiling revealed attenuation of phosphorylated signal transducer and activator of transcription 5 (STAT5) in p110-t-ERBB2-expressing cells compared to controls. Short hairpin-mediated silencing of STAT5 phenocopied p110-t-ERBB2-driven cell migration and invasion, while expression of constitutively active STAT5 reversed these effects. Thus, we provide novel evidence that (1) expression of p110 t-ERBB2 is sufficient for full transformation of HMEC, yielding in vivo xenograft formation, and (2) truncated p110 t-ERBB2 expression is associated with decreased phosphorylation of STAT5.


Assuntos
Neoplasias da Mama/patologia , Movimento Celular/fisiologia , Receptor ErbB-2/metabolismo , Fator de Transcrição STAT5/metabolismo , Animais , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Feminino , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Invasividade Neoplásica , Fragmentos de Peptídeos/metabolismo , Fosforilação , Fator de Transcrição STAT5/genética , Transdução de Sinais , Transplante Heterólogo
5.
Clin Oral Implants Res ; 23(12): 1404-13, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22092925

RESUMO

OBJECTIVES: This study aimed to analyse the association between polymorphisms in the IL1 gene cluster and failure of dental implants in a Portuguese population. MATERIAL AND METHODS: A total of 155 Caucasian Portuguese subjects were divided into two groups: 100 with successful dental implants and 55 with unsuccessful dental implants. DNA was obtained through an oral mucosa scraping. PCR was used to identify the polymorphisms: single nucleotide changes in positions -889 of IL1A gene and +3953 of IL1B gene. RESULTS: The prevalence of the polymorphisms -889IL1A gene and +3953IL1B gene, determined by the positive result of TGP (Genetic Test for Periodontitis; CGC, Genetics, Portugal), in the studied population rehabilitated with dental implants was of 33.50%. Allele 1 of the IL1B gene was the most prevalent (62.20%), followed by allele 1 of the IL1A gene (54.80%) and the least frequent was allele 2 of IL1B gene (37.40%). Success of dental implants was mainly associated with a negative TGP result, whereas no success was found to be related to a positive result. There were no statistically significant differences between the alleles 1 and 2 of the genes IL1A and IL1B and the tobacco and alcohol consumption for the success or no success of the dental implants. CONCLUSIONS: The alleles 1 and 2 of IL1A gene and the alleles 1 and 2 of IL1B gene were statistically associated with the success or no success of the dental implants. Tobacco habit and alcohol consumption showed no statistically significant association with success or no success of the dental implants.


Assuntos
Implantes Dentários , Falha de Restauração Dentária , Interleucina-1alfa/genética , Interleucina-1beta/genética , Polimorfismo de Nucleotídeo Único , Adulto , Idoso , Consumo de Bebidas Alcoólicas/epidemiologia , Alelos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Portugal/epidemiologia , Fatores de Risco , Fumar/epidemiologia , Inquéritos e Questionários
6.
Eur J Pharm Biopharm ; 67(1): 18-30, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17317124

RESUMO

This work reports the preparation of dexamethasone in nanoparticle-coated microparticles and the study of the influence of such microencapsulation on drug absorption across Caco-2 cell monolayers. Nanoparticle-coated microparticles were prepared by spray-drying using nanocapsules (NC) or nanospheres (NS) in aqueous suspensions as coating material. Drug contents ranged from 64 to 134mgg(-1), yields between 49% and 67% and moisture content below 2.0%. SEM and AFM analysis demonstrated that the nanoparticle-coated microparticles (20-53microm) show nanostructures on their surface with a similar diameter compared to the aqueous suspensions. The type of nanocoating material had a significant influence on the drug release profile and on the drug permeation across Caco-2 cells: NC-coated microparticles led to a prolonged release and slower transport across Caco-2 cell monolayers, while the NS-coated microparticles showed a faster release and Caco-2 transport compared to uncoated microparticles. The correlation between the amount of drug permeated and the drug released (%) suggests that the drug absorption from such a delivery system is controlled mainly by the release rate rather than by epithelial permeability. Caco-2 transport studies appear to be a useful characterization tool for the development of microparticulate oral controlled release systems.


Assuntos
Dexametasona/administração & dosagem , Dexametasona/metabolismo , Nanopartículas , Transporte Biológico , Células CACO-2 , Química Farmacêutica , Dexametasona/farmacocinética , Composição de Medicamentos , Excipientes , Humanos , Umidade , Concentração de Íons de Hidrogênio , L-Lactato Desidrogenase/metabolismo , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Modelos Estatísticos , Tamanho da Partícula , Difração de Raios X
7.
Eur J Dent Educ ; 10(1): 32-7, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16436082

RESUMO

OBJECTIVE: To measure and analyse noise levels in the learning-teaching activities at the Dental School of the University of Porto (Portugal). MATERIALS AND METHODS: Sound levels were measured in five different practice areas and laboratories, selected as representative of a variety of learning-teaching activities. The noise levels were determined using a precision sound level meter that was positioned at ear level and at 1 m distance from the operator. RESULTS: The noise levels registered vary between 60 and 99 dB(A) and are similar to the data of other international studies. The results recorded differences in sound levels when the equipment was merely turned on and during cutting operations. Differences between brand new and used equipment were also noted. It appears that hearing damage risk may be lesser amongst dentists who use brand new equipment. CONCLUSION: The noise levels detected in this study are considered to be close to the limit of risk of hearing loss.


Assuntos
Ruído Ocupacional , Faculdades de Odontologia , Acústica/instrumentação , Clínicas Odontológicas , Equipamentos Odontológicos , Equipamentos Odontológicos de Alta Rotação , Humanos , Laboratórios Odontológicos , Portugal , Prostodontia/instrumentação , Fatores de Risco
8.
Eur J Orthod ; 27(1): 12-6, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15743858

RESUMO

Endosseous oral implants have been used as orthodontic anchorage in subjects with multiple tooth agenesis, and their application under orthodontic loading has been demonstrated clinically and experimentally. The aim of this investigation was to examine three-dimensional (3D) bone and implant finite element (FE) models. The first model assumed that there was no osseointegration and the second that full osseointegration had occurred. These models were used to determine the pattern and distribution of stresses within the ITI-Bonefit endosseous implant and its supporting tissues when used as an orthodontic anchorage unit. The study examined a threaded implant placed in an edentulous segment of a human mandible with cortical and cancellous bone. The results, using both models, indicated that the maximum stresses were always located around the neck of the implant, in the marginal bone. Thus, this area should be preserved clinically in order to maintain the bone-implant interface structurally and functionally.


Assuntos
Simulação por Computador , Implantes Dentários , Análise de Elementos Finitos , Imageamento Tridimensional , Modelos Biológicos , Aparelhos Ortodônticos , Planejamento de Prótese Dentária , Elasticidade , Humanos , Arcada Parcialmente Edêntula/fisiopatologia , Mandíbula/fisiologia , Osseointegração/fisiologia , Estresse Mecânico , Propriedades de Superfície , Titânio/química
9.
Med Eng Phys ; 26(5): 371-8, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15147745

RESUMO

The standard illumination set-up for measurement of in-plane displacement in electronic speckle pattern of interference (ESPI) requires the use of two oblique coherent beams for the illumination of the object. These two beams define a direction in the plane perpendicular to the optical axis in which the displacement can be measured, while in the perpendicular direction the interferometer has no sensitivity. In this paper, a new ESPI system for the measurement of in-plane displacements is used. The novelty presented by this assembly is the use of optical fibres to split and guide the light beams. In this way, it is possible to vary with great precision and ease the direction of the projected beams and, consequently, the direction of the plane in which the displacements undergone by the object can be studied. This set-up makes possible the study of objects with complex geometries, which have deformations with unknown symmetry. We present results obtained with this interferometer applied to the study of the mechanical behaviour of the human jaw.


Assuntos
Tecnologia de Fibra Óptica/instrumentação , Interpretação de Imagem Assistida por Computador/métodos , Interferometria/instrumentação , Arcada Osseodentária/anatomia & histologia , Arcada Osseodentária/fisiologia , Algoritmos , Desenho de Equipamento , Análise de Falha de Equipamento , Tecnologia de Fibra Óptica/métodos , Humanos , Interferometria/métodos , Registro da Relação Maxilomandibular/instrumentação , Registro da Relação Maxilomandibular/métodos , Movimento/fisiologia , Estimulação Física/métodos , Amplitude de Movimento Articular/fisiologia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estresse Mecânico
10.
J Biomech ; 36(3): 329-37, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12594981

RESUMO

A three-dimensional finite element model of a fractured human mandible treated with plating technique was developed to simulate and to study the biomechanical loads and the stress field distribution. Biomechanical properties of bone have been thoroughly investigated experimentally. In this work, using the finite element method, complete clinical conditions (after surgical reduction, post-operatory period, complete healing period) were simulated. The mandible fracture was located in the symphysis region and one or two titanium miniplates, fixed with monocortical screws, were evaluated. The behaviour of a reduced human mandible with screwed miniplates, as well as its complete healing, is investigated and described.


Assuntos
Placas Ósseas , Parafusos Ósseos , Consolidação da Fratura/fisiologia , Fraturas Mandibulares/fisiopatologia , Modelos Biológicos , Simulação por Computador , Elasticidade , Análise de Elementos Finitos , Humanos , Fraturas Mandibulares/cirurgia , Osseointegração/fisiologia , Estresse Mecânico , Suporte de Carga
11.
Br Dent J ; 188(2): 63-4, 2000 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-10689766

RESUMO

The term mesiodens refers to a supernumerary tooth that is present in the midline of the maxilla between the two central incisors. One or two mesiodentes may be present. We present a rare case of two sisters, in both of whom a pair of mesiodentes caused the retention of permanent incisors. They were referred to our hospital with asymptomatic delayed eruption of upper incisors. This article is written to point out genetic factors as the possible origin of supernumerary teeth.


Assuntos
Incisivo/patologia , Dente Supranumerário/genética , Dente não Erupcionado/genética , Adolescente , Criança , Feminino , Humanos , Maxila , Erupção Dentária , Dente Decíduo/patologia , Dente Supranumerário/complicações , Dente Supranumerário/cirurgia , Dente não Erupcionado/etiologia
12.
Med Oral ; 5(1): 42-46, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11507538
14.
Eur J Orthod ; 21(4): 413-21, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10502904

RESUMO

An understanding of the mechanical behaviour of the human mandible during mastication may be useful in several specific medical fields that examine the maxillofacial area. In this research, the Electronic Speckle Pattern Interferometry Optical Technique was applied to study a dry mandible under external stress. Two images of the mandible, i.e. an image of the relaxed mandible and another of the mandible under stress, were processed using this technique and provided information concerning the most stressed areas of the bone. The advantage of interferometric analysis is that it can be carried out in real time on a mandible to which progressively greater stress has been applied. This research may be of value in maxillofacial surgery, for example, in the diagnosis and treatment of fractured mandibles, and in oral surgery and orthodontics, where it can provide information concerning stress dispersion when an osteointegrated implant or orthodontic appliance is placed in the mouth. One of the most important conclusions to be drawn from the experiments of tension, compression, and in- and out-of-plane deformations is that the capability of the mandible to bend is superior to its capability to stretch. Several quantitative results support this conclusion.


Assuntos
Interferometria , Mandíbula/fisiologia , Mastigação/fisiologia , Feminino , Humanos , Lasers , Masculino , Mandíbula/fisiopatologia , Estresse Mecânico , Cirurgia Bucal , Gravação em Vídeo
15.
Med Oral ; 4(5): 588-606, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-11507529
16.
Tex Heart Inst J ; 20(4): 293-5, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8298328

RESUMO

Papillary fibroelastoma is a rare cardiac tumor arising most frequently from valvular endocardium. These tumors are clinically important because of their tendency to embolize. Emphasis is therefore placed on early detection and surgical excision. We describe a case of a papillary fibroelastoma arising from the right atrium. To our knowledge, only 2 such cases have been reported in the English literature. Our case illustrates the discovery of a rare, but potentially fatal cardiac tumor, successfully removed by surgery.


Assuntos
Fibroma/diagnóstico , Fibroma/cirurgia , Neoplasias Cardíacas/diagnóstico , Neoplasias Cardíacas/cirurgia , Idoso , Fibroma/patologia , Átrios do Coração , Neoplasias Cardíacas/patologia , Humanos , Masculino
17.
Am Heart J ; 113(6): 1345-52, 1987 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3591602

RESUMO

The focus of this investigation was to examine the potential beneficial effects of the selective thromboxane synthetase inhibitor CGS 13080 (imidazo [1,5-a] pyridine-5-hexanoic acid) on coronary blood flow after streptokinase-induced thrombolysis. Thrombotic occlusion of the circumflex coronary artery was produced by electrolytic (100 microA anodal current) injury to the intimal surface of the circumflex coronary artery at the site of a noncircumferential stenosis in dogs anesthetized with pentobarbital to have open-chest surgery. Intracoronary streptokinase, 6000 IU/kg in 3 ml saline solution, was infused at 0.05 ml/min for 1 hour, beginning 30 minutes after the formation of an occlusive thrombus. The animals were assigned randomly to two groups. In group I (n = 10) the intravenous infusion of vehicle was begun simultaneously with the intracoronary administration of streptokinase and continued for 2 hours after thrombolysis had been achieved. The animals in group II (n = 10) received intravenous CGS 13080 (1 mg/kg/hr) along with intracoronary streptokinase. Infarct size was assessed by a dual perfusion technique with Evans blue and triphenyltetrazolium stains to demarcate the normally perfused myocardium from the area at risk and the infarct zone within the risk region. The two groups did not differ with respect to baseline coronary blood flow, time to the development of coronary artery thrombotic occlusion, or time to achieve thrombolysis. Oscillations in coronary blood flow were more frequent in group I than in group II (group I, 9 +/- 2.2; group II, 4.4 +/- 0.8 oscillation/min X 100, p less than 0.05 [mean +/- SEM)].(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Circulação Coronária/efeitos dos fármacos , Fibrinolíticos/uso terapêutico , Imidazóis/uso terapêutico , Piridinas/uso terapêutico , Estreptoquinase/uso terapêutico , Tromboxano-A Sintase/antagonistas & inibidores , Animais , Artérias , Trombose Coronária/complicações , Trombose Coronária/tratamento farmacológico , Trombose Coronária/fisiopatologia , Cães , Hemodinâmica , Masculino , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/patologia , Recidiva
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...