A common approach to segment an MRI dataset is to use a standard atlas to identify different regions of interest. Existing 2D atlases, prepared by freehand tracings of templates, are seldom complete for 3D volume segmentation. Although many of these atlases are prepared in graphics packages like Adobe Illustrator® (AI), which present the geometrical entities based on their mathematical description, the drawings are not numerically robust. This work presents an automatic conversion of graphical atlases suitable for further usage such as creation of a segmented 3D numerical atlas. The system begins with DXF (Drawing Exchange Format) files of individual atlas drawings. The drawing entities are mostly in cubic spline format. Each segment of the spline is reduced to polylines, which reduces the complexity of data. The system merges overlapping nodes and polylines to make the database of the drawing numerically integrated, i.e. each location within the drawing is referred by only one point, each line is uniquely defined by only two nodes, etc. Numerous integrity diagnostics are performed to eliminate duplicate or overlapping lines, extraneous markers, open-ended loops, etc. Numerically intact closed loops are formed using atlas labels as seed points. These loops specify the boundary and tissue type for each area. The final results preserve the original atlas with its 1272 different neuroanatomical regions which are complete, non-overlapping, contiguous sub-areas whose boundaries are composed of unique polylines

A doença degenerativa da cartilagem articular, ou osteoartrose, pode ser causada por diversos fatores, dentre eles o envelhecimento. Com o aumento da longevidade no Brasil, a prevalência da osteoartrose vai aumentar com o aumento progressivo da idade média da população nas próximas décadas. O estresse do dia a dia, com o avanço da vida moderna, são acompanhados pela má alimentação, sendo essa caracterizada por uma subnutrição ou até uma nutrição excessiva. Utilizando ratos Wistar, como modelo experimental, o objetivo deste trabalho é verificar se a alimentação com baixo nível calórico ameniza ou acelera as alterações na estrutura da cartilagem articular das epífises distal do fêmur e proximal da tíbia, causadas pelo envelhecimento. Para tanto foram utilizadas 15 ratos, separados em três grupos, com 5 animais cada: C- animais de 06 meses alimentados com dieta normal (A); SR- animais de 18 meses alimentados dieta normal (A); RC- animais de 18 meses submetidos à restrição calórica de 31% alimentados com dieta B. A avaliação foi realizada pela microscopia de luz em cortes histológicos corados pela Hematoxilina-Eosina, Picrossírius e por imunohistoquímica com marcação do colágeno tipo II. Foram feitas medidas da espessura das zonas da cartilagem articular, contado o número de condrócitos por área, determinados os volumes dos núcleos dos condrócitos, a morfometria do colágeno, a identificação dos tipos de colágeno e a análise imunohistoquímica. Os resultados mostram que os animais do grupo RC ganharam massa corpórea de maneira significativamente mais lenta que os do SR a partir dos 8 meses. Os animais do SR apresentaram na tíbia, aumento da espessura total bicondilar provocado pelo aumento da zona profunda, aumento do número de condrócitos no côndilo lateral, manutenção do volume dos núcleos e da proporção volumétrica de colágeno, marcação mais heterogenea do colágeno tipo II no côndilo lateral, predominância desse tipo de fibras na zona média do côndilo medial. No fêmur os animais do SR mostraram diminuição da espessura total bicondilar provocada pela diminuição da zona profunda, sendo menor no côndilo medial, diminuição do número de condrócitos causado por diminuição da zona profunda, sendo menor no côndilo medial, diminuição do volume total dos núcleos dos condrócitos no côndilo medial, diminuição da proporção volumétrica do colágeno bicondilar, marcação heterogênea do colágeno tipo II, predomínio desse tipo de fibras nas zonas média e profunda bicondilar. Os animais do RC apresentaram na tíbia, manutenção da espessura, aumento do número de condrócitos bicondilar, manutenção do volume nuclear, aumento da densidade de colágeno, marcação menos heterogênea do colágeno tipo II no côndilo lateral, predominância desse tipo de fibras nas zonas média e profunda do côndilo lateral. No fêmur, os animais do RC mostraram aumento da espessura total pelo aumento da zona profunda no côndilo medial, aumento do número de condrócitos pelo aumento da zona profunda, sendo maior no côndilo medial, aumento do volume total dos núcleos dos condrócitos bicondilar, aumento da proporção volumétrica de fibras colágenas no côndilo medial, marcação heterogênea do colágeno tipo II e predomínio desse tipo de fibras nas três zonas da cartilagem. Dessa maneira, concluímos que os efeitos do envelhecimento e da restrição calórica são diferentes nas cartilagens articulares da tíbia e do fêmur. As alterações naturais do envelhecimento são amenizadas pela restrição calórica na cartilagem articular do fêmur, porém na cartilagem articular da tíbia, essas alterações são compatíveis com início de doença degnerativa sendo intensificadas pela restrição com sinias de avanço de osteoartrose. / A degenerative disease of articular cartilage, or osteoarthritis, can be caused by several factors, including aging. With increased longevity in Brazil, the prevalence of osteoarthritis will increase with the progressive increase of the average age of the population in the coming decades. The stress of everyday life, with the advance of modern life, are accompanied by poor diet, this being characterized by malnutrition or even excessive nutrition. Using Wistar rats as experimental model, the aim of this work is to verify if feeding with low calorie softens or accelerates changes in the structure of articular cartilage of the epiphysis of the distal femur and proximal tibia, caused by aging. For this purpose were used 15 rats divided into three groups with five animals each: C, 6 month animals fed with normal diet (A), SR-18 month animals fed with normal diet (A), RC-18 month animals submitted to calorie restriction of 31% fed with diet B. The evaluation was performed by light microscopy in histological sections stained with Hematoxylin-Eosin, Picrossirius and by immunohistochemistry with tagging of type II collagen. Measurements were made of thick zones of articular cartilage, counted the number of chondrocytes per area, the volumes of certain nuclei of chondrocytes, collagen morphometry, the identification of the types of collagen and immunohistochemical analysis. The results show that the RC group animals gained body mass significantly slower than the SR from 8 months. The SR animals showed increasing of total thickness bicondylar of the tibia caused by the increase in the deep zone, increasing of the number of chondrocytes in the lateral condyle, maintaining the volume of the cores and the volumetric proportion of collagen, the most heterogeneous labeling of type II collagen in the lateral condyle, predominance of such fibers in the middle zone of the medial condyle. In the femur the SR animals showed decreased of total bicondylar thickness caused by the decrease of deep zone, being lower in the medial condyle, decreasing the number of chondrocytes caused by decreased deep zone, being lower in the medial condyle, decreased total volume of nuclei chondrocytes in the medial condyle, decreased volumetric proportion of collagen bicondylar, marking heterogeneous collagen type II predominance of such fibers in the middle and deep zones bicondylar. The RC animals showed in the tibia, maintaining thickness, increasing the number of chondrocytes bicondylar, maintenance of nuclear volume, increased collagen density, less heterogeneous marking of type II collagen in the lateral condyle, the predominance of this type of fiber areas and average deep lateral condyle. In the femur, the animals RC showed increased of total thickness caused by increasing of the medial condyle deep zone, increasing the number of chondrocytes by increasing the deep zone, being greater in the medial condyle, increasing the total volume of the nuclei of chondrocytes bicondylar, increased volumetric proportion of collagen fibers in the medial condyle, heterogeneous marking of type II collagen and prevalence of this type of fiber in the three zones of cartilage. Thus, we conclude that the effects of aging and caloric restriction are different in the articular cartilage of the tibia and femur. The natural changes of aging are attenuated by caloric restriction in the articular cartilage of the femur, but in the articular cartilage of the tibia, these changes are consistent with early degenerative disease being intensified by restriction with signs of advanced osteoarthritis.

Made available in DSpace on 2014-06-11T19:22:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-04-07Bitstream added on 2014-06-13T18:48:40Z : No. of bitstreams: 1 strang_r_me_botfm.pdf: 1503065 bytes, checksum: c600d4becf4eafb0269428ce7cb268b7 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Foi realizado estudo experimental em ratos, visando avaliar o efeito da ablação cirúrgica dos músculos retos abdominais (MRA), nos padrões utilizados nos retalhos TRAM, sobre a resistência da parede abdominal. Utilizou-se 60 ratos machos da linhagem Wistar, divididos aleatoriamente em três grupos de 20 animais. No primeiro grupo removeu-se um dos músculos, no segundo, ambos e o terceiro grupo, controle, não foi submetido à cirurgia. Após 180 dias os animais foram sacrificados e submetidos a dois tipos de avaliação: aumento progressivo da pressão intracavitária, com o auxílio de um balão de silicone, para a observação do surgimento de abaulamentos ou hérnias, e teste de tração em dinamômetro, para quantificar a resistência da parede abdominal à tração. O segmento operado das paredes abdominais foi submetido à análise histológica. Constatou-se no primeiro teste não haver diferença significativa entre os três grupos. No teste da tração, as paredes abdominais submetidas à cirurgia apresentaram resistência significativamente maior do que as do grupo controle. A histologia evidenciou fibrose cicatricial madura, uniformemente distribuída, e fibras musculares em posição anatômica. Na análise estatística, para comparar os valores da pressão de ruptura (mmHg) e da Tração-Força Máxima (N) dos três grupos foi utilizada Análise de Variância de um fator. Quando o resultado do teste F foi estatisticamente significante, aplicou-se o Post-Hoc de Tukey para se identificar as diferenças. Concluiu-se que, no modelo utilizado, a remoção cirúrgica dos MRA não provoca redução na resistência da parede abdominal. / This experimental study was carried out in rats, with the purpose to evaluate the effect of the surgical ablation of the rectus abdominis muscles (RAM), in the patterns of the TRAM flap, on the resistance of the abdominal wall. Sixty male Wistar rats were used, divided randomly in three groups of twenty animals. In the first group, one of the muscles was removed, in the second, both and the third group, the control group, was not submitted to the surgery. After 180 days the animals were killed and submitted to two types of evaluation: an increase in the intracavitary pressure, with the help of a silicone balloon, to observe the emergence of bulge or hernia, and a test in a dynamometer to quantify the resistance of the abdominal wall to traction. The operated segment of the abdominal walls was submitted to histological analysis. In the first test, it was testified that there was no significant difference between the three groups. In the traction test, the abdominal walls submitted to the surgery showed a resistance significantly greater than the ones on the control group. Histology evidenced mature cicatricial fibrosis, evenly distributed, and muscular fibers in anatomical position. In the statistical analysis, to compare the values of rupture pressure (mmHg) and the Maximum Traction-Force (N) of the three groups it was used one-way Analysis of Variance. When the F test result showed to be statistically significant, the Tuckey test was applied to identify the differences. It was concluded that, in the used model, the surgical removal of the RAM didn’t cause a reduction in the abdominal wall resistance.

In recent years, worldwide obesity rates have risen dramatically, putting major strain on public health systems and the economy. Obesity is a multifaceted disease and its development can be influenced by a variety of factors including genetic, psychological and environmental influences. One area of current focus in obesity research is that of early life programming. It has been well-established that certain early life factors can impact the physiology and behaviour of the offspring. Because of this, early life programming has become increasingly well studied in order to develop a deeper understanding of how early life can influence obesity development. Another area of interest lies in positive mood. While there has been much research into the effects of negative states such as stress and anxiety on feeding behaviour, there is still very little known about how positive states can influence food choice. Using rat models of prenatal stress, neonatal overnutrition and positive affect, this thesis aimed to investigate the effects of early life and mood factors on feeding behaviour and food choice. Prenatal stress has been extensively studied and is characterised by an enhanced stress response in the offspring. Using two rat models of prenatal stress- social and restraint stress, the effects of prenatal stress on feeding behaviour and food choice in the offspring were examined. In both models, no effects of prenatal stress on either food intake or food choice were observed. However, in both cases the expected alterations to the offspring's stress responses when exposed to an acute stressor were not replicated. This may suggest that models of prenatal stress are not as robust as often cited in the literature. As well as the prenatal environment, the early postnatal environment is also able to influence physiology and behaviour. In terms of obesity, a well-studied model is that of small litter size. Rats from small litters are over-nourished as neonates and because of this illustrate an increased body weight that persists throughout life. While this increase in weight gain has been well-established, there is no evidence examining the impact of neonatal overnutrition on long-term food choice. Therefore, food intake and food choice were measured in small and control litter rats over a 10-week period. When placed on an ad lib diet of bland chow, sucrose and lard, small litter rats consumed significantly more chow than control litter rats, whilst maintaining similar consumption of lard and sucrose. However, when offered a high-fat high-sugar (HFHS) pellet for two hours a day alongside ad lib chow, small litter rats illustrated increased consumption of the HFHS pellet compared to controls. This suggests that small litter rats may be programmed to adjust their food choices to enable them to maintain their increased body weight in comparison to controls. To examine the effects of positive affect on feeding behaviour, ultrasonic vocalisations (USVs, specifically those at 50 kHz) were used as a measure of positive affect in rats. In order to examine whether access to a food reward could induce a positive affect (as measured by an increase in 50 kHz USVs), rats were schedule-fed sweetened condensed milk and USVs measured before, during and after consumption. No differences in 50 kHz USVs were observed suggesting that a palatable food, whilst rewarding, does not alter affective state in the rat. Using heterospecific social contact (a tickling interaction simulating rough and tumble play) to induce positive affect, rats were presented with an hour-long sucrose preference test following social contact in order to examine the impact of positive affect on food choice. While no differences in sucrose consumption were found, a reduced sucrose preference was observed in rats receiving social contact compared to controls, suggesting that positive affect may play a role in mediating food choice. Finally, the effects of fasting (a negative stimulus thought to reduce 50 kHz USVs) and a food reward on motivation for social contact were examined. Both fasting and access to a food reward resulted in no differences in conditioned place preference to receive social interaction. Overall, the results obtained in this thesis implicate both neonatal overnutrition and, for the first time, positive affect as possible mediators of food choice, although further studies are required to fully establish these effects. Importantly, these results also raise questions regarding the reproducibility of some early life models, such as prenatal stress, and highlights the importance of sharing precise experimental protocols across laboratories. Through further investigation of the effects of early life and affective states on food consumption and choice, and the mechanisms behind these, this may enable the development of therapeutic interventions and preventative measures that can help slow, or even reverse, the global obesity epidemic.

The aim of this research was to identify the molecular mechanisms that promote spontaneous activation in rat eggs after their recovery from the oviduct. Typically, mammalian eggs await fertilisation arrested at the second metaphase II of meiosis. However, ovulated rat eggs spontaneously enter anaphase II when exposed to in vitro culture. After extrusion of the second polar body, these spontaneously activated eggs do not proceed to interphase but become arrested at metaphase III stage with chromatids scattered in the egg cytoplasm. This instability may be one factor that has made it more difficult to establish reliable protocols for somatic cell nuclear transfer in rats. The triggers of spontaneous activation and signalling pathways leading to the metaphase III progression are largely unknown. Analyses of signalling pathways that are involved in the regulation of final stages of meiosis during fertilisation revealed several anomalies that were associated with spontaneous activation and the transition from metaphase II to metaphase III. Metaphase II arrested eggs usually exhibit an increased level of maturation promoting factor (MPF) activity. Spontaneous activation in rat eggs was associated with a drop in MPF activity at the time of the second polar body extrusion. MPF is composed of a catalytic subunit, CDK1, and a regulatory subunit, cyclin B1. Interestingly, the level of cyclin B1 was stable throughout spontaneous activation. Post-translational modifications of CDK1 can influence MPF activity: whereas no inhibitory phosphorylation on Tyr15 of CDK1 was found; a decrease in activating Thr161 phosphorylation of CDK1 was associated with the time of the second polar body extrusion, and hence could contribute to the transient MPF inactivation. MAPK (p42/p44) activity has been shown to decrease during egg activation in fertilisation. By contrast, during spontaneous activation, MAPK (p42/p44) remained active and thus resembled the profile usually found between two meiotic divisions (metaphase I to metaphase II). Securin, a protein which prevents premature chromatid separation, was degraded in eggs going through spontaneous activation. Cytostatic factor (CSF) is a biochemical activity, which enables stable metaphase II arrest in ovulated eggs of vertebrates. Recently, the endogenous meiotic inhibitor 2, EMI2, was confirmed as the major component of CSF. For egg activation to occur, the CSF must be destroyed. At the beginning of egg activation, Ca2+/calmodulin kinase (CaMKII) promotes posttranslational modifications of EMI2, leading to its degradation. In the rat, inhibition of CaMKII activity stably prevented the onset of spontaneous activation in a subset of metaphase II eggs. However, no degradation of EMI2 protein was found at the start of abortive metaphase II exit. This finding revealed that one of the central elements of the CSF pathway, EMI2, could be preserved in the rat eggs going through spontaneous activation. In order to study the mechanisms regulating EMI2 stability in rat oocyte maturation and spontaneous activation, functional analysis of ectopically expressed synthetic mRNA was performed. The mechanism enabling EMI2 degradation became active 12 hours after the start of oocyte maturation. The C-terminal fragment of EMI2, known to be non-degradable in Xenopus oocyte maturation, was significantly more stable than the full-length counterpart in matured rat eggs but not during oocyte maturation. Interestingly, C-terminal EMI2 became degraded in parthenogenetic rat embryos. This indicated that additional not previously reported mechanisms responsible for EMI2 degradation might exist in the rat. The microinjection of metaphase II rat eggs with the C-terminal fragment of EMI2 or IVT full-length EMI2 protein had little effect on the progression of spontaneous activation. Taken together, these observations suggest that abortive spontaneous activation in rat eggs was a result of incomplete engagement of signalling pathways normally triggered in fertilisation or parthenogenetic activation. Activation of CaMKII initiated pathways that allowed anaphase entry and chromatid segregation. At the same time, not all pathways normally triggered during fertilisation or parthenogenetic activation were fully engaged, possibly due to the presence of non-degraded component of CSF. Abortive incomplete activation results in the re-establishment of high level of MPF activity in metaphase III eggs. Early prevention of CaMKII activation, perhaps by blocking [Ca2+ i] signalling, may provide a means of holding ovulated eggs at metaphase II prior to enucleation and somatic cell nuclear transfer.

No description available.

A incidência de osteoartose, ou degeneração da cartilagem articular aumenta na pós-menopausa, condição esta relacionada à deficiência de estrógeno. Por outro lado, tem sido demonstrado que a atividade física regular e moderada tem efeitos benéficos sobre o sistema esquelético, em qualquer condição, mas especialmente na menopausa. Utilizando ratos Wistar, como modelo experimental, os objetivos deste trabalho são: a) verificar se a ooforectomia produz alterações na estrutura da cartilagem articular da epífise proximal da tíbia e b) verificar se a realização de exercícios físicos aeróbicos tem efeito sobre estas alterações. Para a realização deste estudo foram utilizadas 24 ratas com 6 meses de idade, da linhagem Wistar, distribuídas em 3 grupos de oito ratas cada: GC-Ratas com seis meses de idade, não submetidas à ooforectomia nem atividade física; GOS-Ratas com seis meses de idade, que sofreram ooforectomia bilateral, mas que não fizeram atividade física e, GOT-Ratas com seis meses de idade que foram submetidas à ooforectomia bilateral mais atividade física (corrida em esteira) durante 3 meses. Todos os animais foram eutanasiados com 9 meses de idade. A avaliação foi realizada através de microscopia de luz em cortes histológicos corados pela Hematoxilina-Eosina e pelo Picrossírius e estudos à microscopia eletrônica de varredura. À microscopia de luz, foram feitas medidas da espessura das zonas da cartilagem articular, contado o número de condrócitos por área, determinados os volumes dos núcleos dos condrócitos e a densidade de volume das fibras colágenas e à microscopia eletrônica de varredura foi analisada a superfície da cartilagem nos três grupos. Os dados quantitativos foram comparados estatisticamente pelo ANOVA e teste de Tukey. Os resultados mostraram que houve um aumento de peso nos animais do GOS e GOT em relação ao GC. Quanto ao treinamento, os animais do GOT tiveram melhor rendimento nos TEMs. Quanto à espessura da cartilagem observamos um aumento da espessura da zona superficial no côndilo medial da tíbia no GOS em relação ao GC. O número de condrócitos por campo foi alterado apenas no GOS, que mostrou um aumento de 34% em relação ao GC, o que, ao que parece, se deveu ao aumento do número de condrócitos da camada profunda. O volume nuclear dos condrócitos da zona superficial foi menor no GOS que no GC. O mesmo ocorreu na zona média do côndilo medial. Quanto aos valores da cartilagem da epífise proximal como um todo, observamos que o volume nuclear dos condrocitos do GOS e também do GOT foram menores do que do GC. Para o colágeno observamos um aumento da densidade de volume do colágeno no GOS e no GOT em relação ao GC. A microscopia eletrônica revelou a presença de lesões degenerativas semelhantes tanto para o GOS, quanto para o GOT. Podemos concluir que a depressão dos níveis de estrógeno acarreta alterações importantes na cartilagem articular da epífise proximal da tíbia tanto no componente celular, quanto na matriz e que a realização de exercícios físicos, isoladamente, parece não influenciar essas alterações. / The incidence of osteoarthritis increase in women in the post-menopausal period. This condition is relationed with the estrogen deficiency. Otherwise, it\'s being demonstrated that regular or moderate physical activity have beneficial effects on the skeletal system, in any condition, but especially in the menopause. Using Wistar rats, as an experimental model, the aims of this work are: a) to check if the ovariectomy produces alterations in the articular cartilage structure of the tibial proximal epiphysis and b) To check if aerobic physical exercises have effects on this alterations. To achieve these goals it was used 24 Wistar rats of 6 months of age, distributed in 3 groups of eight rats each: Control group- Rats with six months of age without ovariectomy and physical activity; GOS- Rats with six months of age with ovariectomy bilateral and without physical activity and, GOT- Rats with six months of age with ovariectomy bilateral and physical activity during 3 months. Al rats were euthanasied with 9 months of age. The results were obtained by using light microscopy to observe the histological sections stained with Hematoxylin and Eosin, and Picrosirius stain and the Scanning Electron Microscope. For light microscopy, were measured the thickness of cartilage, counted the number of chondrocytes, determined the volumes nuclei of chondrocytes and the density of volume of the collagens fibers. For the Scanning Electron Microscope, was analyzed the cartilage surface in the three groups. The data were statistically compared for the ANOVA and Tukey´s test. The results showed that there was an increase in the weight in the animals of GOS and of GOT. In relation to training, the animals of GOT obtained the best income in the TEMs. In relation to the thickness of the articular cartilage it was observed a decrease in the superficial layer of the medial condyle in the GOS and GOT. The number of chondrocytes was altered only in the GOS, that obtained an increase of the 34% on GC in the deep layer. The nuclear volume of chondrocytes in the superficial layer was higher in the GC than the GOS .The same occurred in the medium layer when the two tibial condyles, lateral and medial were assessed separately, but when the values of the epiphysial cartilage was considered as a whole, we found that the volume nuclei of chondrocytes in the GC was higher than the GOS and the GOT. For the collagen, the values of density of volume of the collagen fibers was higher in the GOS and in the GOT than the GC. The Scanning Electron microscopy showed the presence of degenerative lesions in both GOS and GOT. We can conclude that the depression levels of estrogen produced important changes in the tibial cartilage and that the physical activity doesn\'t have effects on these changes.

Problemas de consolidação óssea são um grande desafio clínico, pois geram altos custos de tratamento, morbidades e prejuízos a qualidade de vida. A técnica de regeneração óssea guiada é empregada com o intuito de promover a melhora no processo de regeneração de defeitos ósseos através da utilização de barreiras biológicas, que protegem o local da lesão e favorecem a ação de células osteogênicas. A membrana de látex natural, extraído da seringueira Hevea brasiliensis tem sido apontado como um biomaterial promotor da regeneração em diferentes tecidos, e por este motivo escolhido como objeto de estudo desta pesquisa. O objetivo foi avaliar o efeito da utilização de membrana de látex natural no processo de regeneração guiada de defeito ósseo em ossos longos de ratos, através de análises estruturais, radiológicas, microscópicas e da expressão de proteínas osteogênicas. Foram utilizados sessenta ratos Wistar divididos igualmente em quatro grupos (n=15), sendo: animais tratados com membrana de látex por uma (L1) ou quatro semanas (L4) e animais que não receberam tratamento específico por uma (C1) ou quatro semanas (C4). Um defeito ósseo de 2,5 mm de diâmetro foi realizado na região medial da tíbia esquerda de cada animal. Nos animais do grupo tratado, uma membrana de látex foi posicionada sobre os defeitos ósseos. Após os períodos experimentais de uma ou quatro semanas os animais foram submetidos a eutanásia e a tíbia esquerda de cada animal foi dissecada, limpa das partes moles e submetida às análises macroscópica, densitométrica, radiológica, mecânica, histomorfométrica, estereológica e imunohistoquímica. A influência das varáveis tempo e membrana, bem como a interação tempo*membrana sobre os dados foram avaliadas. Para os dados referentes à imunomarcação de osteocalcina foi aplicado teste de modelo linear generalizado com fatores independentes. Para o restante dos resultados foi realizada análise de ANOVA multivariada com dois fatores independentes. Todas as comparações foram realizadas com ajuste de Bonferroni e adotado nível de significância de 5%. Foram observadas diferenças estatisticamente significantes em relação a variável tempo, em que grupos avaliados quatro semanas após a cirurgia apresentaram resultados superiores para as medidas de comprimento (p<0,001), massa (p<0,001), força máxima (p<0,001) e rigidez relativa da tíbia (p<0,001), bem como para as medidas de densidade radiológica (p=0,008), densidade mineral óssea (p=0,017), volume ósseo neoformado (p<0,001) e fibras de colágeno tipo III (p<0,001). Em relação à utilização da membrana de látex, os grupos tratados apresentaram resultados estatisticamente superiores para as análises de rigidez relativa (p=0,048), fibras de colágeno tipo I (p=0,018), volume ósseo neoformado (p<0,001) e expressão de osteopontina (p=0,037). Concluímos que a utilização de membrana de látex em regeneração óssea guiada em defeitos realizados em tíbias de ratos melhorou sensivelmente a regeneração do tecido. / Problems of bone consolidation are a significant clinical challenge, as they generate high treatment costs, morbidities, and damages to the quality of life. The guided bone regeneration technique is used to improve the regeneration process of bone defects through the use of biological barriers that protect the site and favor the action of osteogenic cells. The natural latex membrane extracted from the rubber tree Hevea brasiliensis has been identified as a biomaterial promoting regeneration in different tissues, and for this reason chosen as the object of study of this research. The objective was to evaluate the effect of the use of natural latex membrane in the process of guided regeneration of bone defect in long bones of rats, through structural, radiological, microscopic analysis and the expression of osteogenic proteins. Sixty Wistar rats were equally divided into four groups (n = 15): latex membrane treated animals for one (L1) or four weeks (L4) and animals that received no specific treatment for one (C1) or four weeks (C4). A bone defect of 2.5 mm diameter was performed in the medial region of the left tibia of each animal. In the animals of the treated group, a latex membrane was positioned over the bone defects. After the experimental periods of one or four weeks, the animals were submitted to euthanasia, and the left tibia of each animal was dissected, cleaned of soft parts and submitted to macroscopic, densitometric, radiological, mechanical, histomorphometric, stereological and immunohistochemical analysis. The influence of the variable time and membrane as well as the time * membrane interaction on the data were evaluated. For the data referring to the osteocalcin immunostaining, a generalized linear model with independent factors was applied. For the rest of the results, a multivariate ANOVA analysis was performed with two independent factors. All comparisons were performed with Bonferroni adjustment and adopted a significance level of 5%. Statistically significant differences were observed in relation to the time variable, in which groups evaluated four weeks after surgery presented superior results for the measures of length (p <0.001), mass (p <0.001), maximal strength (p <0.001) and stiffness (P <0.001), as well as for measurements of radiological density (p = 0.008), bone mineral density (p = 0.017), neoformed bone volume (p <0.001) and type III collagen fibers (p <0.001) ). About the use of the latex membrane, the treated groups presented statistically superior results for analyzes of relative stiffness (p = 0.048), type I collagen fibers (p = 0.018), neoformed bone volume (p <0.001) and expression of Osteopontin (p = 0.037). We conclude that the use of latex membrane in guided bone regeneration in defects performed in rat tibiae significantly improved tissue regeneration.

A técnica de isquemia-reperfusão tem sido utilizada em cirurgias conservadoras do rim como a nefrectomia parcial e em transplantes renais. Para se realizar a isquemia pode-se fazer o bloqueio do fluxo sanguíneo da artéria renal ou o bloqueio simultâneo da artéria e da veia renal. O evento isquêmico acarreta em dano celular ao rim principalmente pelo estresse oxidativo local e a liberação de radicais livres assim como o aumento da resposta inflamatória. Diversos autores verificaram lesão renal após a isquemia-reperfusão, porém, apenas testes funcionais foram realizados até o momento. Os autores que tentaram avaliar a lesão morfológica do rim apenas fizeram a quantificação de escores subjetivos. O nosso objetivo é avaliar por quantificação estereológica o dano causado pela isquemia-reperfusão comparando o clampeamento somente arterial com o clampeamento arteriovenoso. Utilizamos 24 ratos wistar, machos, de quatro meses de idade. Os animais foram divididos em três grupos: o grupo Sham (n=8), o grupo de clampeamento somente da artéria renal (n=8) e o grupo de clampeamento simultâneo da artéria e da veia renal (n=8). Os animais foram submetidos a laparotomia mediana. Os animais do grupo Sham permaneceram os 60 minutos anestesiados mas sem obstrução do fluxo sanguíneo de seus vasos renais. Os animais do grupo de clampeamento arterial foram submetidos à clampeamento de sua arterial renal esquerda por 60 minutos e os animais do grupo de clampeamento arterial e venoso tiveram seus vasos renais esquerdos clampeados simultaneamente e em bloco pelo mesmo tempo. Após os 60 minutos os animais foram suturados e mantidos por 30 dias em caixas próprias sendo mortos por sobredose anestésica após decorrido esse tempo. Os rins foram coletados e mantidos em solução de formalina tamponada e posteriormente processados para análise histológica e estereológica. Foram analisados a densidade volumétrica (Vv) dos glomérulos, o número de glomérulos/mm3(Nv) e o volume glomerular médio (VGM). A Vv e Nv se encontrou reduzida nos rins esquerdos submetidos à isquemia mas foi somente significativa nos animais do grupo de clampeamento arterial e venoso. Mesmo usando o rato como modelo animal experimental, a partir de nossos resultados recomendamos o uso do clampeamento somente arterial nos casos em que mínina lesão ao rim é imperiosa. / The ischemia-reperfusion has been used in renal surgery such as conservative partial nephrectomy and kidney transplantation. To perform ischemia we can block the blood flow of renal artery or simultaneous blockade of the renal artery and vein. The ischemia leads to cellular damage to the kidney mainly by local oxidative stress and releasing free radicals as well as increased inflammatory response. Several authors related renal injury after ischemia-reperfusion, however; only functional tests were carried out to date. The authors attempted to evaluate the morphological lesion of the kidney using subjective scores. Our goal is assess by stereological quantification of the renal parenchyma after ischemia-reperfusion injury comparing arterial only clamping and arteriovenous clamping. We used 24 Wistar rats, males, four months old. The animals were divided into three groups: Sham group (n = 8), the group of clamping of the renal artery (n = 8) and the group of simultaneous clamping of renal artery and vein (n = 8). The animals underwent laparotomy. Sham group animals remained anesthetized for 60 minutes without blood flow obstruction of their renal vessels. The group animals underwent arterial clamping have had his left renal artery clamped for 60 minutes and the animals in the group of arterial and venous clamping had their left renal vessels clamped simultaneously for the same time. After 60 minutes the animals were sutured and kept for 30 days in their own boxes being killed by anesthetic overdose after that. The kidneys were collected and kept in formaldehyde solution and subsequently processed for histological and stereological analysis. We analyzed the volume density (Vv) of the glomeruli, the number of glomeruli/mm3 (Nv) and mean glomerular volume (MGV). The Vv and Nv was reduced in the ischemic left kidney but was only significant in animals of the group of arterial and venous clamping. Even using the rat as experimental animal model, from our results we recommend the use of arterial clamping only in cases where minimum injury to the kidney is imperative.

Dentre as diversas possibilidades de reconstrução de tecidos ósseos atróficos, a regeneração óssea guiada é uma das mais promissoras. Neste contexto, muitas membranas reabsorvíveis tem sido desenvolvidas e precisam ser testadas como parte de sua caracterização. O objetivo do presente estudo foi avaliar radiográfica e histologicamente em um estudo in vivo, se uma nova membrana polimérica eletrofiada de PCL/poli(rotaxona) demonstra comportamento semelhante a uma membrana de colágeno, comercialmente consagrada, quanto à promoção de regeneração óssea guiada. Foi realizado defeito crítico de 8mm de diâmetro na calvária de 60 ratos Wistar machos. Em dois grupos iguais (n=20) os defeitos foram recobertos aleatoriamente por uma membrana de colágeno suíno ou por uma membrana polimérica mista de policaprolactona (PCL) e poli(rotaxona). Em um terceiro grupo (n=20) os defeitos não foram recobertos e permaneceram apenas com o coágulo. Os animais sofreram eutanásia em 7, 14, 21 e 42 dias pós operatórios. Espécimes da região foram radiografadas e preparadas para análise histológica. Radiograficamente, os defeitos recobertos pela membrana de colágeno suíno apresentaram diminuição mais significativa da área radiográfica dos defeitos de acordo com a progressão dos períodos pós-operatórios do que nos outros grupos. A histomorfologia do reparo mostrou agrupamentos mais expressivos de células gigantes no grupo PCL/poli(rotaxona) sugerindo resposta à corpo estranho. Na histomorfometria, a neoformação óssea foi significativamente mais intensa e com osso neoformado mais maduro no grupo Colágeno. Concluímos que para um modelo de regeneração óssea guiada, a membrana de PCL/poli(rotaxona) não superou a membrana de colágeno. / The need to rebuild lost bone tissue, shows up as one of the great challenges of modern dentistry. Among several possibilities, guided bone regeneration is one of the most established techniques. In this context, many resorbable membranes have been developed and need to be tested as part of their characterization. The aim of this study was to evaluate by an in vivo model, if a new electrospinning PCL/polyrotaxane polymer membrane promotes similar guided bone regeneration when compared to a collagen membrane. An 8mm diameter critical defect was made in 60 male Wistar rats calvaria. In two equal groups (n = 20) the defects were randomly covered with a porcine collagen or a PCL/polyrotaxane membranes. In a third group (n = 20) the defects remained uncovered and just the blood clot occupied the defect. The animals were euthanized at 7, 14, 21 and 42 days post-operative. Specimens were x-rayed and prepared for histological analysis. Radiographically, the defects covered by porcine collagen membrane, showed more significant reduction in defect area, according to postoperative period evolution. Histomorphology showed intense giant cells presence in the PCL/polyrotaxane group, suggesting a foreign body response. The histomorphometric analysis showed new and mature bone formation more intense in collagen group. Under the limits of this study, the collagen membrane performance in guided tissue regeneration was far superior to the PCL/polyrotaxane membrane.