Comprovação da real comunicação entre o endodonto e o periodonto através do canal cavo inter-radicular e sua prevalência em molares inferiores humanos

The neurovascular system of the pulp and of the periodontium is interconnected and among the possible intercommunications between these two tissues, there is the cavo inter-radicular canal. It is a small canal that goes through any inter-radicular dentine and arises in the furca region of the multi-radicular teeth. Its predominance has been studied in the literature, by several methodologies, with divergent results. The objective of this work was to establish, in vitro, the predominance of the cavo inter-radicular canal, in human lower molars, through the diaphanization technique and dye leakage. For this research, 140 teeth (100 first and second 40 lower molars) were selected, extracted due to different reasons, belonging to a teeth bank of the Endodontics discipline of the Dentistry College at Federal University of Rio Grande do Norte. The teeth were preserved in formol until the moment of use and immersed in physiological solution. Had the endodontic access fulfilled and the whole external surface, except for the furcation, sealed with two layers of nail enamel. The cleaning of the pulpar chamber floor was carried out with sodium hypochlorite solution 5%, being this solution renewed every 5 minutes, during 1 hour. The teeth were immersed in Indian dye and, after drying of the dye, they had their crowns split up in the amelo-cemental junction. Then, they were examined in a stereomicroscope, where marks of the coloring were observed in the furcation and on the pulpar floor. After this recording, the sample was diaphanized and with the transparent teeth, it was possible to observe in the stereomicroscope, the true inter-radicular canals. As a result of this experiment, the presence of these canals was observed in 13 % of the first and 7, 5 % of the second evaluated molars. The study showed that both the presence of the cavo inter-radicular canal is real and the diaphanization and dye leakage is an efficient method for this type of research

Framework for analysis and representation of external systems for online reactive-optimisation studies

The paper proposes a framework for the analysis and representation of external systems for online optimisation studies. The basis for this framework is the equivalent OPF (EOPF), an optimisation model obtained by partitioning of the OPF model. The EOPF is mathematically redefined in the paper to accommodate the concept of a buffer zone. The resulting model is more useful for online optimisation, since external information obtained through intercontrol-centre exchange contracts can be used to improve internal control calculation. Numerical results obtained with original studies involving the boundary-matching procedure have provided a conceptual basis for the definition of a buffer zone for optimisation studies with the EOPF. In the proposed framework, the accuracy of the external representation in optimisation studies is evaluated by comparing the controls obtained by an EOPF procedure with those obtained by the reference-optimisation procedure defined in this paper. The framework is then used to evaluate the accuracy of equivalent optimisation studies involving the IEEE 118-bus test system and the Brazilian South Southeast 810-bus system. The results show that the incorporation of a buffer zone improves the external system representation for all optimisation studies performed.

Gravitational effects of Nix and Hydra in the external region of the Pluto-Charon system

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

Artificial neural networks for load flow and external equivalents studies

In this paper an artificial neural network (ANN) based methodology is proposed for (a) solving the basic load flow, (b) solving the load flow considering the reactive power limits of generation (PV) buses, (c) determining a good quality load flow starting point for ill-conditioned systems, and (d) computing static external equivalent circuits. An analysis of the input data required as well as the ANN architecture is presented. A multilayer perceptron trained with the Levenberg-Marquardt second order method is used. The proposed methodology was tested with the IEEE 30- and 57-bus, and an ill-conditioned 11-bus system. Normal operating conditions (base case) and several contingency situations including different load and generation scenarios have been considered. Simulation results show the excellent performance of the ANN for solving problems (a)-(d). (C) 2010 Elsevier B.V. All rights reserved.

Treatment of segmental tibial defects using acute bone shortening followed by gradual lengthening with circular external fixator

The aim of this study was to clinically and radiographically evaluate acute bone shortening followed by gradual lengthening in the treatment of large segmental tibia defects induced in seven clinically normal dogs. A circular external fixator was assembled with one proximal 5/8-circle ring, one middle ring and one distal ring connected with three rods. Thirty per cent of the tibia and fibula were removed in the middle and distal parts of the diaphyses, between the middle and distal rings. Acute bone shortening with compression of proximal and distal segments was performed. A subperiosteal osteotomy was performed between the half-ring and middle ring. Bone distraction started 7 days after surgery; after lengthening, the apparatus was left in place for 14 weeks for consolidation of regenerated bone. The frame was removed at the end of this period, and the dogs observed for four more weeks. Functional results were considered excellent in two, good in three and fair in the other two dogs. Bone regeneration within the distraction gap was obtained 14 weeks after neutral fixation period. We concluded that acute bone shortening followed by gradual lengthening by Ilizarov method can be used to treat extensive tibial defects in dogs, although it presents limb temporary abnormal limb shape and unequal length as early disadvantages.

Paracoccidioidomycosis of external genitalia: report of six new cases and review of the literature

BACKGROUND: Paracoccidioidomycosis is a systemic mycosis of dermatological interest due to the frequency of cutaneous and mucosal lesions. The involvement of the external genitalia is extremely rare and few cases have been reported.OBJECTIVE: To study the prevalence of external genitalia lesions in paracoccidioidomycosis patients, identify clinical characteristics and compare with what is observed in the specific literature.METHODS: This is a cross-sectional, descriptive study, with focus on paracoccidioiodomycosis patients with external genitalia lesions. The demographic and clinical aspects of cases were compared with what has been reported so far on LILACS, SciELO e MEDLINE data bases.RESULTS: Data of 483 cases of paracoccidioidomycosis were studied in a 42-year period. Six (1.2%) patients showed specific lesions on external genitalia. Five patients were male with mean age of 47.2 years and all of them presented with the chronic multifocal clinical form. Only one, a 15-year-old female patient was observed who showed a subacute clinical form, juvenile type.CONCLUSIONS: Compromise of the genitourinary tract among paracoccidioidomycosis patients is rare and even rarer when only the external genitalia are considered. As observed in the classical picture of paracoccidioidomycosis patients, the male gender and the chronic multifocal clinical form prevailed in the present study.

Best site for embryo transfer: the upper or lower half of endometrial cavity?

BACKGROUND: the objective of the present study was to determine the importance of the site of embryo transfer (upper or lower half endometrial cavity) on implantation and clinical pregnancy rates. METHODS: A total of 400 transfers guided by ultrasound were randomly assigned to two groups according to the distance between the uterine fundus and the catheter tip at the time of embryo placement. Group I (n=200) consisted of transfers corresponding to a distance of <50% of the endometrial cavity length (ECL), i.e. transfer in upper half of the cavity; and group II (n=200) consisted of transfers corresponding to a distance of greater than or equal to50%, of the ECL, i.e. transfer in lower half of cavity. The Student's t-test, Mann-Whitney test and Fisher's exact test were used where appropriate. RESULTS: the general characteristics of the study population and the main transfer cycle characteristics had an equal distribution (P>0.05) between groups I and II. No significant difference in implantation or pregnancy rates was observed between groups I and II. CONCLUSION: the implantation or pregnancy rates were similar whether the embryos were deposited in the upper or lower half of the endometrial cavity.

The influence of external ultrasound on the histologic architecture of the organic capsule around smooth silicone implants: Experimental study in rats

Background Capsular contracture is the main complication related to breast silicone implants, and its prevention remains a medical challenge. The authors present experimental research examining the effect of external ultrasound on the formation and contracture of peri-implant capsules.Methods In this study, 42 male Wistar rats had a 2-mm smooth surface implant placed in a dorsal submuscular pocket. They then were separated into ultrasound'' and control'' groups that received repeated external applications either with or without the ultrasound power on. Ultrasound applications were given three times a week for a period of 90 days. After that, both groups were housed under the same conditions with no application scheduled. Five animals of each group, killed at 30, 60, 90, and 180 days, had their implants removed along with the capsule, which received a special histologic preparation via annular sectioning that provided wide circumferential observation of the capsular tissue. Sections were stained with hematoxylin/eosin stain, Masson's trichrome stain, and Pricrosirius Red stain for regular microscopic evaluation under normal and polarized light.Results Histologic data showed that capsules from the ultrasound and control groups had statistically significant differences. Ultrasound application developed a capsular architecture similar to that shown within textured silicone implants, and its effect had an early definition with subsequent stabilization.Conclusion The authors conclude that early and repeated external ultrasound application enhances the thickness, cellular count, and vascularity of smooth silicone capsular tissue, whereas it diminishes the pattern of parallel orientation of collagen fibers.

Amniotic Fluid Interleukin-1 Beta and Interleukin-6, but not Interleukin-8 Correlate with Microbial Invasion of the Amniotic Cavity in Preterm Labor

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

Uso de 2-octil-cianoacrilato na reconstrução da cavidade anoftálmica de coelhos

OBJETIVO: Avaliar a ligação entre músculos oculares extrínsecos e esferas de polietileno poroso usando um bioadesivo. MÉTODOS: Estudo experimental envolvendo 8 coelhos albinos submetidos a enucleação do olho direto com colocação de implante esférico de polietileno poroso de 12 mm de diâmetro unido aos músculos oculares extrínsecos por meio do bioadesivo 2-octil-cianoacrilato. Noventa dias após a cirurgia os animais foram sacrificados e o conteúdo orbitário removido. em 4 animais foi realizado estudo biomecânico, avaliando-se a força de ruptura entre a musculatura e a esfera (grupo implante) e entre a musculatura e a esclera nos olhos contralaterais (grupo controle). Nos outros 4 animais foi realizada análise histológica. RESULTADO: A avaliação biomecânica revelou que a força de ruptura entre esfera-músculo e esclera-músculo foram semelhantes quando se usa o adesivo de cianoacrilato. O exame histológico mostrou reação fibrovascular no local da adesão entre a musculatura e a esfera, sem efeitos deletérios aos tecidos. Ao redor dos implantes foi possível observar pseudocápsula e no interior, neovasos e tecido fibrovascular preenchendo os espaços entre os grânulos do polietileno. CONCLUSÃO: O adesivo 2-octil-cianoacrilato mantém boa força de adesão na união entre os músculos e as esferas de polietileno poroso, com redução do tempo cirúrgico e sem efeitos deletérios aos tecidos orbitais. Desta forma, deve-se considerar o uso do bioadesivo na reconstrução da cavidade anoftálmica.

Repair of the anophthalmic cavity of rats with synthetic hydroxyapatite

We placed spheres of synthetic hydroxyapatite (calcium chloride combined with sodium phosphate) in the eviscerated or enucleated orbital cavity of rats in order to evaluate the biocompatibility of this material with the orbital cavity. The study was conducted on 50 albino rats, 25 of which were submitted to enucleation and 25 to evisceration of one eye. The animals were sacrificed 7, 15, 21, 30 and 60 days after surgery and the orbital content was submitted to histopathological examination. A reaction of the young granulation tissue type was observed first. The hydroxyapatite was gradually surrounded by a granulomatous macrophage inflammatory response and covered with dense connective tissue that formed a sort of mesh septating and supporting progressively smaller blocks of the substance. The same type of reaction was observed in the enucleated and eviscerated cavities. We conclude that synthetic hydroxyapatite is an inert nonallergenic material which is appropriate for volume replacement in the anophthalmic cavity

Gel and porous polyethylene implants for anophthalmic cavity reconstruction-evaluation using the B scan ultrasound

AIM: To evaluate the host response of the gel and porous polyethylene implants in anophthalmic cavities using the B scan ultrasound.METHODS: Thirty-six white rabbits underwent unilateral enucleation with placement of gel or porous polyethylene spheres implants. The animals were submitted to clinical examination weekly and to ultrasound evaluation on 30, 60 and 90 days after surgery.RESULTS: All rabbits with gel polyethylene spheres, except one, showed implant extrusion probably because the gel spheres have hydrated and increased in volume. The B ultrasound of the gel polyethylene implant did not show vessels inside during the following period. Five animals (27.8%) with porous polyethylene spheres presented implant extrusion after 30 days of surgery. According to B ultrasound, the porous polyethylene implant showed irregular and heterogeneous architecture and reflective peaks similar to vascularized tissues.CONCLUSION: More studies are required to determine the ideal volume of gel polyethylene implant necessary to correct the diminished orbital content in the anophthalmic cavity. The B ultrasound effectiveness showed in this study for anophthalmic socket implants evaluation provides useful information for further in vivo studies and might substitute expensive methods of implants vascularization evaluation,

Avaliação quantitativa das dimensões óculo-palpebrais em portadores de cavidade anoftálmica em uso de prótese ocular externa

OBJETIVOS: Avaliar o posicionamento palpebral em portadores de cavidade anoftálmica com e sem prótese ocular externa, utilizando o processamento de imagem digital. MÉTODOS: Dezoito pacientes foram avaliados qualitativa e quantitativamente na Faculdade de Medicina de Botucatu - Universidade Estadual Paulista - UNESP, com e sem a prótese externa. Usando imagens obtidas por filmadora e processadas usando o programa Scion Image, mediu-se a altura do sulco palpebral superior, a altura da fenda palpebral e os ângulos palpebrais dos cantos interno e externo. RESULTADOS: Pseudo-estrabismo e sulco palpebral superior profundo foram as alterações mais freqüentes ao exame externo. Houve diferença significativa em todas as variáveis estudadas, com diminuição da altura do sulco palpebral superior, aumento da área da fenda palpebral e aumento dos ângulos palpebrais interno e externo quando o paciente estava usando a prótese externa. CONCLUSÃO: Todos os pacientes avaliados apresentaram algum tipo de anormalidade órbito-palpebral, o que reflete a dificuldade em se proporcionar ao portador de cavidade anoftálmica um aspecto idêntico ao que existe na órbita normal. O processamento de imagens digitais permitiu avaliação objetiva das dimensões óculo-palpebrais, o que poderá contribuir nas avaliações seqüenciais dos portadores de cavidade anoftálmica.