189 resultados para ossification


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

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

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OBJETIVOS: determinar a morfologia das 3ª e 4ª vértebras cervicais representativa dos estágios de pré-pico, pico e pós-pico de velocidade de crescimento estatural, definidos previamente pelos centros de ossificação do primeiro dedo em radiografias carpais ou do dedo polegar. MÉTODOS: foram utilizadas 120 telerradiografias em norma lateral de 106 pacientes selecionados da clínica de Ortodontia Preventiva e Interceptiva da Faculdade de Odontologia de Araçatuba-UNESP e Profis/HRAC-USP que apresentavam as correspondentes radiografias carpais ou do dedo polegar. As telerradiografias foram divididas em três grupos de 40 radiografias, de acordo com os estágios maturacionais pré-pico, pico e pós-pico, definidos pela imagem do primeiro dedo. A morfologia dos corpos das 3ª e 4ª vértebras cervicais foi determinada por dois examinadores devidamente calibrados em dois tempos diferentes. CONCLUSÕES: concluiu-se que o formato retangular horizontal com borda inferior reta foi representativo do estágio de pré-pico, independentemente da vértebra analisada. Já o formato retangular horizontal com borda inferior curva, especialmente se encontrado em C4, ou o formato quadrado com borda inferior reta caracterizaram o pico de velocidade de crescimento. O formato quadrado ou, principalmente, o retangular vertical com borda inferior curva determinaram o estágio de pós-pico de velocidade de crescimento da adolescência.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Mineralization of the articular cartilage is a pathological condition associated with age and certain joint diseases in humans and other mammals. In this work, we describe a physiological process of articular cartilage mineralization in bullfrogs. Articular cartilage of the proximal and distal ends of the femur and of the proximal end of the tibia-fibula was studied in animals of different ages. Mineralization of the articular cartilage was detected in animals at 1 month post-transformation. This mineralization, which appeared before the hypertrophic cartilage showed any calcium deposition, began at a restricted site in the lateral expansion of the cartilage and then progressed to other areas of the epiphyseal cartilage. Mineralized structures were identified by von Kossa's staining and by in vivo incorporation of calcein green. Element analysis showed that calcium crystals consisted of poorly crystalline hydroxyapatite. Mineralized matrix was initially spherical structures that generally coalesced after a certain size to occupy larger areas of the cartilage. Alkaline phosphatase activity was detected at the plasma membrane of nearby chondrocytes and in extracellular matrix. Apoptosis was detected by the TUNEL (TDT-mediated dUTP-biotin nick end-labeling) reaction in some articular chondrocytes from mineralized areas. The area occupied by calcium crystals increased significantly in older animals, especially in areas under compression. Ultrastructural analyses showed clusters of needle-like crystals in the extracellular matrix around the chondrocytes and large blocks of mineralized matrix. In 4-year-old animals, some lamellar bone (containing bone marrow) occurred in the same area as articular cartilage mineralization. These results show that the articular cartilage of R. catesbeiana undergoes precocious and progressive mineralization that is apparently stimulated by compressive forces. We suggest that this mineralization is involved in the closure of bone extremities, since mineralization appears to precede the formation of a rudimentary secondary center of ossification in older animals.

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Two new species of brachycephalid frogs are described from Pico Marumbi, municipality of Morretes, and Pico da Igreja, municipality of Guaratuba, Parana State, southern Brazil. The new species share the following attributes: body bufoniform; skin on top of the head, and central part of the back body smooth with no dermal co-ossification; outer metatarsal tubercle distinct; dermal roofing bones of skull unornamented; all paired cranial bones distinct and not fused; quadratojugals, and maxillary odontoids present. The new species from Pico Marumbi is characterized by male SVL = 11.6-12.5 and female SVL = 13.0-14.5 turn; and general color orange with dorsal reddish-brown irregular markings, lateral surfaces with small dark brown spots, and belly with brownish spots and small dots. The new species from Pico da Igreja is characterized by male SVL = 12.6-13.9 and female SVL = 14.6-15.3 mm; and general color orange, lateral surfaces with small dark brown spots, and belly with brownish coalescent spots and small dots. Comparisons with other brachycephalid species and osteological data are provided.

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The mammalian scapula is a complex morphological structure, composed of two ossification plates that fuse into a single structure. Most studies on morphological differentiation in the scapula have considered it to be a simple, spatially integrated structure, primarily influenced by the important locomotor function presented by this element. We used recently developed geometric morphometric techniques to test and quantify functional and phylogenetic influences on scapular shape variation in fossil and extant xenarthran mammals. The order Xenarthra is well represented in the fossil record and presents a stable phylogenetic hypothesis for its genealogical history. In addition, its species present a large variety of locomotor habits. Our results show that approximately half of the shape variation in the scapula is due to phylogenetic heritage. This is contrary to the view that the scapula is influenced only by functional demands. There are large-scale shape transformations that provide biomechanical adaptation for the several habits (arboreality, terrestriality, and digging), and small scale-shape transformations (mostly related to the coracoid process) that are not influenced by function. A nonlinear relationship between morphometric and phylogenetic distances indicates the presence of a complex mixture of evolutionary processes acting on shape differentiation of the scapula. J. Morphol. 241,251-263, 1999. (C) 1999 Wiley-Liss, Inc.

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Fibrodisplasia ossificante progressiva (FOP)-like foi diagnosticada em um felino brasileiro jovem com claudicação progressiva, atrofia, incapacidade de extensão e dor a manipulação dos membros pélvicos. em razão de insuficiência nas respostas aos medicamentos observados na literatura foi preconizado apenas orquiectomia e confinamento do paciente. Apesar de a maioria dos relatos de FOP-like indicar eutanásia, o presente caso está sendo acompanhado há quatro anos, desde o diagnóstico, e apesar de o paciente manter-se com restrições de deambulação, encontra em condições satisfatórias.

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Evaporative water loss (EWL) and oxygen uptake ((V) over dot o(2)) was measured in two species of tree frogs with cranial co-ossification, Aparasphenodon brunoi and Corythomantis greeningi. Both species use their head to seal the entrance of bromeliads, tree holes or rocky crevices used as shelters. EWL was significantly reduced in sheltered individuals of both species as compared with those exposed nude to desiccation. EWL per unit area through the head surface was significantly lower than the body skin for A. brunoi but not for C., greeningi. EWL per unit surface area through C. greeningi body skin was about 50% that of A. brunoi, indicating a less permeable skin in the former species. The relationship between cranial coossification and EWL is discussed. ((V) over dot o(2)) in A. brunoi was comparable with other anurans of similar size, whereas in C. greeningi, it was lower than predicted from body mass. Moreover, ((V) over dot o(2)), in C. greeningi showed less sensitivity to temperature increase than in A. brunoi. C. greeningi occurs in a drier environment than A. brunoi, and this appears to be reflected in their EWL and ((V) over dot o(2)) characteristics. (C) 1997 Elsevier B.V.

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A histological study on the healing of extraction wounds following laser irradiation using a He-Ne laser, was carried out in rats. The results suggest that this mode of treatment has a beneficial effect on initial bony wound healing. Proliferation of fibroblasts and formation of trabecular osteoid tissue were found to be more prominent within the irradiated group. The deposition of led in the newly formed bone suggests swifter ossification within the irradiated group.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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In orofacial implantology there are many types of implants for the different systems. Among these is the implant surface type, e.g., a screw type, cylindrical and laminar. Furthermore, the implants are different in their dimensions, their metal composition, their surface condition, such as smooth, grit or layered surfaces and in their methods of application. Two different self-tapping implants, one smooth and the other grit-blasted, are screwed into the bone, and another one with a plasma of titanium coating, which is also in a screw form but with greater spaces between the screw threads are compared. The greatest amount of bone deposition in the bone/implant interface was encountered in the latter one, the smooth surfaced implant being in second place. All of these systems can alter the implant healing process and to demonstrate this, we injected bone markers in the rabbits over different periods of time so as to observe the different areas of bone deposition in the tibias where the implants had been inserted. The bone tracers used were Alizarin, Calcein and Xylenol-orange. The amount of deposition was calculated by using the method of surface morphometry.

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The study of the contributions of different bones to the formation of the skeleton in birds is necessary: (1) to establish homologies in comparative anatomy; (2) to delimit each bone structure correctly, mainly in relation to the skull and mandible where the bones are fused to each other in adults; and (3) to standardize nomenclature in avian osteology. In this paper at least one young specimen belonging to each sub-family of Cuculidae was examined in order to identify each bone in terms of boundaries and contributions to skull and mandible formation. These cuckoos specimens were also compared with adults and young of turacos and hoatzin. The results show little variation of skull and jaw among the young cuckoos studied compared with the variations among adult specimens. However, it provides new suggestions for the boundaries and nomenclature of certain osseous structures in the skull and mandible of birds, specifically fissura zona flexoria craniofacialis, prominetia frontoparietalis, crista temporalis transversa, processus squamosalis, fossa laterosphenoidalis, tuberculum laterosphenoidale and processus retroangularis. This study also provides more reliable homologies for use in cladistic analysis and above all it contributes to the phylogenetic position of Cuculidae within Neognathae, specifically the skull formation suggest that turacos and hoatzin are more similar to each other than either is to the cuckoos. © 2005 Taylor & Francis.