375 resultados para PALATAL CRIB
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Stereotypies are repetitive and relatively invariant patterns of behavior, which are observed in a wide range of species in captivity. Stereotypic behavior occurs when environmental demands produce a physiological response that, if sustained for an extended period, exceeds the natural physiological regulatory capacity of the organism, particularly in situations that include unpredictability and uncontrollability. One hypothesis is that stereotypic behavior functions to cope with stressful environments, but the existing evidence is contradictory. To address the coping hypothesis of stereotypies, we triggered physiological reactions in 22 horses affected by stereotypic behavior (crib-biters) and 21 non-crib-biters (controls), using an ACTH challenge test. Following administration of an ACTH injection, we measured saliva cortisol every 30min and heart rate (HR) continuously for a period of 3h. We did not find any differences in HR or HR variability between the two groups, but crib-biters (Group CB) had significantly higher cortisol responses than controls (Group C; mean±SD: CB, 5.84±2.62ng/ml, C, 4.76±3.04ng/ml). Moreover, crib-biters that did not perform the stereotypic behavior during the 3-hour test period (Group B) had significantly higher cortisol levels than controls, which was not the case of crib-biters showing stereotypic behavior (Group A) (B, 6.44±2.38ng/ml A, 5.58±2.69ng/ml). Our results suggest that crib-biting is a coping strategy that helps stereotypic individuals to reduce cortisol levels caused by stressful situations. We conclude that preventing stereotypic horses from crib-biting could be an inappropriate strategy to control this abnormal behavior, as it prevents individuals from coping with situations that they perceive as stressful.
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Submitted in partial fulfillment of the requirements for a Certificate in Orthodontics, Dept. of Orthodontics, University of Connecticut Health Center, 1986
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The cleft palate presented by transforming growth factor-β3 (Tgf-β3 ) null mutant mice is caused by altered palatal shelf adhesion, cell proliferation, epithelial-to-mesenchymal transformation and cell death. The expression of epidermal growth factor (EGF), transforming growth factor-β1 ( Tgf-β1 ) and muscle segment homeobox-1 (Msx-1) is modified in the palates of these knockout mice, and the cell proliferation defect is caused by the change in EGF expression. In this study, we aimed to determine whether this change in EGF expression has any effect on the other mechanisms altered in Tgf-β 3 knockout mouse palates. We tested the effect of inhibiting EGF activity in vitro in the knockout palates via the addition of Tyrphostin AG 1478. We also investigated possible interactions between EGF, Tgf-β 1 and Msx-1 in Tgf-β 3 null mouse palate cultures. The results show that the inhibition of EGF activity in Tgf-β 3 null mouse palate cultures improves palatal shelf adhesion and fusion, with a particular effect on cell death, and restores the normal distribution pattern of Msx-1 in the palatal esenchyme. Inhibition of TGF-β 1 does not affect either EGF or Msx-1 expression.
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Inscription: Verso: mother takes baby to work - infant crib in office, New York.
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This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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Background India has a large and evolving HIV epidemic. Little is known about cancer risk in Indian persons with HIV/AIDS (PHA) but risk is thought to be low. Methods To describe the state of knowledge about cancer patterns in Indian PHA, we reviewed reports from the international and Indian literature. Results As elsewhere, non-Hodgkin lymphomas dominate the profile of recognized cancers, with immunoblastic/large cell diffuse lymphoma being the most common type. Hodgkin lymphoma is proportionally increased, perhaps because survival with AIDS is truncated by fatal infections. In contrast, Kaposi sarcoma is rare, in association with an apparently low prevalence of Kaposi sarcoma-associated herpesvirus. If confirmed, the reasons for the low prevalence need to be understood. Cervical, anal, vulva/vaginal and penile cancers all appear to be increased in PHA, based on limited data. The association may be confounded by sexual behaviors that transmit both HIV and human papillomavirus. Head and neck tumor incidence may also be increased, an important concern since these tumors are among the most common in India. Based on limited evidence, the increase is at buccal/palatal sites, which are associated with tobacco and betel nut chewing rather than human papillomavirus. Conclusion With improving care of HIV and better management of infections, especially tuberculosis, the longer survival of PHA in India will likely increase the importance of cancer as a clinical problem in India. With the population's geographic and social diversity, India presents unique research opportunities that can be embedded in programs targeting HIV/AIDS and other public health priorities.
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Antechinus mysticus sp. nov. occurs in coastal Australia, ranging from just north of the Queensland (Qld)/New South Wales (NSW) border to Mackay (mid-east Qld), and is sympatric with A. flavipes (Waterhouse) and A. subtropicus Van Dyck & Crowther in south-east Qld. The new species can be distinguished in the field, having paler feet and tail base than A. flavipes and a greyish head that merges to buff-yellow on the rump and flanks, compared with the more uniform brown head and body of A. subtropicus and A. stuartii Macleay. Features of the dentary can also be used for identification: A. mysticus differs from A. flavipes in having smaller molar teeth, from A. subtropicus in having a larger gap between front and rear palatal vacuities, and from A. stuartii in having a generally broader snout. Here, we present a morphological analysis of the new species in comparison with every member of the genus, including a discussion of genetic structure and broader evolutionary trends, as well as an identification key to species based on dental characters. It seems likely that the known geographic range of A. mysticus will expand as taxonomic focus on the genus is concentrated in south-east Queensland and north-east New South Wales.
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We provide a taxonomic redescription of the ubiquitous and variable dasyurid marsupial Yellow-footed Antechinus, Antechinus flavipes (Waterhouse), which comprises three currently recognized subspecies whose combined geographic distribution spans almost the length and breadth of Australia. A. flavipes leucogaster Gray is confined to south-west Western Australia; A. flavipes flavipes is distributed in south-eastern Australia across four states—South Australia, Victoria, New South Wales and Queensland; A. flavipes rubeculus Van Dyck is confined to the wet tropics of Queensland. A. flavipes is readily distinguished from all extant congeners based on external morphology by the following combination of features: a grey head; orange-yellow toned flanks/rump, feet and tail base; pale eye-rings and a darkened tail tip. A. flavipes skulls are stout, being broad at the level of the rear upper molars, have small palatal vacuities and small entoconid cusps on the lower molars. However, notable differences among subspecies of A. flavipesprevent any obvious collection of skull characters being diagnostic for species-level discrimination among congeners. A. flavipes rubeculus is the largest of the three subspecies of Yellow-footed Antechinus and most similar in skull morphology to A. leo, A. bellus and A. godmani—all four species are geographically limited to tropical Australia. A. f. rubeculus is notably larger in many characters than its conspecifics: A. f. flavipes, the next largest, and A. f. leucogaster, the smallest of the group. A. f. flavipes and A. f. leucogaster diverge significantly at only a few skull characters, and both subspecies have cranial morphological affinities with the recently discovered A. mysticus, most notably A. f. leucogaster. Phylogenies generated from mt- and nDNA data strongly support Antechinus flavipes as monophyletic with respect to other members of the genus; within A. flavipes, each of the three recognized subspecies form distinctive monophyletic clades.
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We provide a taxonomic redescription of the dasyurid marsupial Atherton Antechinus, Antechinus godmani (Thomas). A. godmani is only rarely encountered and limited to wet tropical rainforests of north-east Queensland, Australia, between the towns of Cardwell and Cairns (a distribution spanning 135 kilometres from north to south). The distinctive species occurs at altitudes of over 600 meters asl, in all major rainforest types, and can be found with both the northern subspecies of the Yellow-footed Antechinus, A. flavipes rubeculus Van Dyck and the Rusty Antechinus, A. adustus (Thomas). A. god-mani is clearly separated from all congeners on the basis of both morphometrics and genetics. A. godmani can be distin-guished from all extant congeners based on external morphology by a combination of large size, naked-looking tail and reddish fur on the face and head. A. godmani skulls are characteristically large, with a suite of long features: basicranium, palate, upper premolar tooth row, inter-palatal vacuity distance and dentary. Phylogenies generated from mt- and nDNA data position Antechinus godmani as monophyletic with respect to other members of the genus; A. godmani is strongly supported as the sister-group to a clade containing all other antechinus, but excluding the south-east Australian Dusky An-techinus, A. swainsonii (Waterhouse) and Swamp Antechinus, A. minimus (Geoffroy). Antechinus godmani are genetically very divergent compared to all congeners (mtDNA: range 12.9–16.3%).
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Antechinus argentus sp. nov. is currently only known from the plateau at the eastern escarpment of Kroombit Tops National Park, about 400km NNW of Brisbane and 60km SSW of Gladstone, south-east Queensland, Australia. Antechinus flavipes (Waterhouse) is also known from Kroombit Tops NP, 4.5km W of the nearest known population of A. argentus; A. mysticus Baker, Mutton and Van Dyck has yet to be found within Kroombit Tops, but is known from museum specimens taken at Bulburin NP, just 40km ESE, as well as extant populations about 400km to both the south-east and north-west of Kroombit NP. A. argentus can be easily distinguished in the field, having an overall silvery/grey appearance with much paler silver feet and drabber deep greyish-olive rump than A. flavipes, which has distinctive yellow-orange toned feet, rump and tail-base; A. argentus fur is also less coarse than that of A. flavipes. A. argentus has a striking silver-grey head, neck and shoulders, with pale, slightly broken eye-rings, which distinguish it from A. mysticus which has a more subtle greyish-brown head, pale buff dabs of eyeliner and more colourful brownish-yellow rump. Features of the dentary can also be used for identification: A. argentus differs from A. flavipes in having smaller molar teeth, as well as a narrower and smaller skull and from A. mysticus in having on average a narrower snout, smaller skull and dentary lengths and smaller posterior palatal vacuities in the skull. A. argentus is strongly divergent genetically (at mtDNA) from both A. flavipes (9.0–11.2%) and A. mysticus (7.2–7.5%), and forms a very strongly supported clade to the exclusion of all other antechinus species, in both mtDNA and combined (mtDNA and nDNA) phylogenies inferred here. We are yet to make detailed surveys in search of A. argentus from forested areas to the immediate east and north of Kroombit Tops. However, A. mysticus has only been found at these sites in low densities in decades past and not at all in several recent trapping expeditions conducted by the authors. With similar habitat types in close geographic proximity, it is plausible that A. argentus may be found outside Kroombit. Nevertheless, it is striking that from a range of surveys conducted at Kroombit Tops in the last 15 years and intensive surveys by the authors in the last 3 years, totalling more than 5 080 trap nights, just 13 A. argentus have been captured from two sites less than 6 km apart. If this is even close to the true geographic extent of the species, it would possess one of the smallest distributions of an Australian mammal species. With several threats identified, we tentatively recommend that A. argentus be listed as Endangered, pending an exhaustive trapping survey of Kroombit and surrounds.
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The development of many embryonic organs is regulated by reciprocal and sequential epithelial-mesenchymal interactions. These interactions are mediated by conserved signaling pathways that are reiteratively used. Cleidocranial dysplasia (CCD) is a congenital syndrome where both bone and tooth development is affected. The syndrome is characterized by short stature, abnormal clavicles, general bone dysplasia, and supernumerary teeth. CCD is caused by mutations in RUNX2, a transcription factor that is a key regulator of osteoblast differentiation and bone formation. The first aim of this study was to analyse the expression of a family of key signal molecules, Bone morphogenetic protein (Bmp) at different stages of tooth development. Bmps have a variety of functions and they were originally discovered as signals inducing ectopic bone formation. We performed a comparative in situ hybridisation analysis of the mRNA expression of Bmp2-7 from initiation of tooth development to differentiation of dental hard tissues. The expression patterns indicated that the Bmps signal between the epithelial and mesenchymal tissues during initiation and morphogenesis of tooth development, as well as during the differentiation of odontoblasts and ameloblasts. Furthermore, they are also part of the signalling networks whereby the enamel knot regulates the patterning of tooth cusps. The second aim was to study the role of Runx2 during tooth development and thereby to gain better understanding of the pathogenesis of the tooth phenotype in CCD. We analysed the tooth phenotype of Runx2 knockout mice and examined the patterns and regulation of Runx2 gene expression.. The teeth of wild-type and Runx2 mutant mice were compared by several methods including in situ hybridisation, tissue culture, bead implantation experiments, and epithelial-mesenchymal recombination studies. Phenotypic analysis of Runx2 -/- mutant tooth development showed that teeth failed to advance beyond the bud stage. Runx2 expression was restricted to dental mesenchyme between the bud and early bell stages of tooth development and it was regulated by epithelial signals, in particular Fgfs. We searched for downstream targets of Runx2 by comparative in situ hybridisation analysis. The expression of Fgf3 was downregulated in the mesenchyme of Runx2 -/- teeth. Shh expression was absent from the enamel knot in the lower molars of Runx2 -/- and reduced in the upper molars. In conclusion, these studies showed that Runx2 regulates key epithelial-mesenchymal interactions that control advancing tooth morphogenesis and histodifferentiation of the epithelial enamel organ. In addition, in the upper molars of Runx2 mutants extra buddings occured at the palatal side of the tooth bud. We suggest that Runx2 acts as an inhibitor of successional tooth formation by preventing advancing development of the buds. Accordingly, we propose that RUNX2 haploinsuffiency in humans causes incomplete inhibition of successional tooth formation and as a result supernumerary teeth.
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A expansão rápida da maxila cirurgicamente assistida tornou-se amplamente utilizada e muito aceitável no tratamento da deficiência maxilar de pacientes adolescentes e adultos. Diversas técnicas cirúrgicas foram propostas ao longo dos anos com o objetivo de solucionar este problema de forma eficiente, com estabilidade dos resultados e baixa morbidade. Controvérsias em relação ao procedimento cirúrgico persistem, principalmente relacionadas a quais osteotomias devem ser realizadas para se obter bons resultados. O objetivo deste trabalho foi avaliar os resultados da expansão ortocirúrgica da maxila realizando osteotomias nas paredes laterais da maxila e na sutura palatina mediana. Foram selecionados dezessete pacientes adultos portadores de deficiência transversa maxilar, com média de idade de 24 anos e 8 meses; todos foram submetidos a exames de tomografia computadorizada convencional e moldagens maxilares previamente ao procedimento cirúrgico e após três meses, no mínimo, do término de ativação e estabilização do aparelho expansor. As medidas do pós-cirúrgico foram confrontadas com as do pré-cirúrgico e os resultados foram comparados e analisados estatisticamente. Foi obtida a expansão desejada clinicamente em todos os pacientes. No entanto, a quantidade de expansão na região de molares foi estatisticamente maior nas áreas referentes aos dentes, enquanto que os resultados obtidos referentes aos caninos se mostraram similares nas três regiões maxilares avaliadas. Quando comparadas às regiões de caninos e molares entre si, a expansão intercaninos foi maior na altura dos forames palatinos e o inverso ocorreu nas regiões de processo alveolar e dentária, nas quais a expansão intermolar foi maior.
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O objetivo deste trabalho é analisar in vitro a dissipação de tensões em incisivos centrais superiores humanos restaurados com facetas de cerâmica feldspática, através da análise do método dos elementos finitos, considerando cargas funcionais de mastigação e corte dos alimentos, em função de três tipos de preparos utilizados: sem proteção incisal; com proteção incisal em ângulo e com proteção incisal em degrau palatino. Foram utilizadas modelagens bidimensionais de um incisivo central superior e suas estruturas de suporte, simulando três situações: (Primeira modelagem) incisivo central superior com desgaste vestibular (em forma de janela); (Segunda modelagem) incisivo central superior com desgaste vestibular e proteção incisal em plano inclinado; (Terceira modelagem) incisivo central superior com desgaste vestibular, e proteção incisal com degrau palatino. Foi considerada uma carga (P=100N) com uma inclinação de 45 concentrada, simulando a região de contato do incisivo central inferior com o superior durante a mastigação e uma na região de contato topo a topo dos incisivos superior e inferior, simulando o corte dos alimentos. Após a análise dos dados obtidos pela distribuição de tensões, pode-se concluir que quanto à dissipação das tensões em todo o sistema proposto, com a aplicação de carga em 45, não foram observadas mudanças no estado tensional nos três diferentes preparos. Quando foi aplicada carga vertical, simulando o contato de topo, houve variação no estado tensional no sistema do dente com preparo em janela. Nas facetas, com a aplicação de carga em 45, nos preparos em janela e com proteção incisal em plano inclinado o resultado foi semelhante nos valores tensionais enquanto, nas facetas em dentes preparados com proteção incisal com degrau palatino, a distribuição foi mais homogênea tendo valores superiores, mostrando que o abraçamento do dente diminuiu a flexão.