O objetivo deste estudo foi analisar a modulação da expressão de metaloproteinases da matriz-2 e -9, no tecido ósseo neoformado na interface do implante derivado do polímero da mamona (Ricinus communis) com o canal medular da tíbia de coelhos, por meio de análise histológica por microscopia óptica, tomografia computadorizada e imunoistoquímica. Foram selecionados 44 coelhos machos, Oryctolagus cuniculus, da linhagem Nova Zelândia, albinos, divididos em dois grupos, sendo o Grupo 1, composto por 12 animais controle, cujas fresagens do canal medular foram produzidas bilateralmente nas tíbias e não preenchidas e, o Grupo 2, com 30 animais, cujos canais medulares da tíbia, após fresagem, foram preenchidos bilateralmente com os cilindros derivados da poliuretana da mamona. Os animais do Grupo 1 e Grupo 2 foram divididos aleatoriamente em subgrupos experimentais, conforme as datas de eutanásia pré-determinadas em 90, 120, 150 dias após o ato operatório. Um animal não foi submetido ao procedimento de fresagem, sendo utilizado para controle histológico e outro submeteu-se à eutanásia após o implante do polímero, sendo utilizado para controle de imagem do estudo com tomografia computadorizada. Decorridos os períodos experimentais, os animais foram submetidos à eutanásia, as peças removidas e encaminhadas para o exame tomográfico; posteriormente ao processamento histológico, as lâminas foram analisadas em microscópio óptico. As Metaloproteinases da Matriz (MMPs) são um importante grupo de enzimas proteolíticas zinco-dependentes responsáveis pela degradação de matriz extracelular e membranas basais. As enzimas são secretadas em uma forma latente e se tornam ativadas no ambiente pericelular, sendo relacionadas a processos fisiológicos e patológicos. No presente estudo, foram revisados alguns aspectos importantes das MMPs, discutindo-se o papel dessas enzimas em processos fisiológicos como a neoformação e maturação óssea (MMP-2). Dentre os processos patológicos que envolvem a participação das MMPs, destacam-se a reabsorção óssea e processos inflamatórios (MMP-9). A expressão de metaloproteinase da matriz-2 e -9 nos tecidos foi avaliada por meio de imunoistoquímica. Os dados obtidos foram submetidos à análise estatística por meio do teste ANOVA seguido pelo pós-teste de Tukey (α = 0,05). No grupo experimental, aos 90 dias, a interface com o polímero apresentava uma camada espessa de tecido ósseo neoformado rico em osteócitos, o qual apresentou uma maturação com o passar do tempo, aos 120 e 150 dias pós-implantação. No grupo controle, a superfície interna junto ao canal medular apresentava-se revestida por osteoblastos, seguida de faixa de tecido ósseo, com poucas lacunas preenchidas por osteócitos. O amadurecimento do tecido da superfície interna medular acontece na região interior, sendo o osso alamelar, constituído por fibras colágenas menos amadurecidas que o osso lamelar. As imagens tomográficas demonstraram não haver espaço entre a superfície do material e do osso na interface implante/medula óssea, sendo a densidade dos tecidos nesta interface semelhante à densidade das demais porções da medula óssea. O processo de remodelação óssea observado histologicamente foi acompanhado pela modulação positiva de metaloproteinase da matriz-2 durante todo o período de avaliação com baixa expressão de metaloproteinase da matriz-9. / The aim of this study was to evaluate the modulation of matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9) expression in newly formed bone tissue at the interface between implant derived from castor oil (Ricinus communis) polymer and the medullary canal of rabbit tibia, by histological examination under optical microscopy, computed tomography (CT) and immunohistochemical analysis. For such purpose, 44 rabbits (Oryctolagus cuniculus, New Zealand, albinus) were selected and assigned to two groups. In Group 1, composed of 12 animals (control), reamings of the medullary canal were produced bilaterally in the tibiae of the rabbits and were not filled. In Group 2, composed of 30 animals, the tibial medullary canals, after reaming, were filled bilaterally with cylinders derived from castor oil polyurethane. The animals of Groups 1 and 2 were randomly divided in experimental subgroups, according to the periods of predetermined euthanasia, which were 90, 120, 150 days postoperatively. One animal was not subjected to the reaming procedure, and served as a histological control; another animal was killed after placement of the polymer implant, and served as a control for CT imaging. Euthanasia was undertaken at the established experimental periods, and the anatomic specimens were removed and subjected to CT analysis. Then, after histological processing, the slides were examined under optical microscopy. MMPs are an important group of zinc-dependent proteolytic enzymes responsible for the degradation of extracellular matrix and basal membranes. The enzymes are synthesized in a latent form and are activated in the pericellular environment, being involved in physiological and pathological processes. In the present study, some important aspects of MMPs were reviewed, and the role of these enzymes in physiological processes, such as new bone formation and bone maturation (MMP-2), was discussed. Among the pathological processes that have the participation of MMPs, the most relevant are bone resorption and inflammatory processes (MMP-9). MMP-2 and MMP-9 expression in the tissues was evaluated by immunohistochemistry. Data were subjected to statistical analysis by ANOVA and Tukey post-test (α = 0.05). In the group experimental, at 90 days, the interface with the polymer presented a thick layer of newly formed bone tissue rich in osteocytes. This tissue exhibited an ongoing maturation at 120 and 150 days post-implantation. In the control group, the internal surface close to the medullary canal was lined by osteoblasts, followed by a bone tissue zone with few lacunae filled with osteocytes. Maturation of the tissue of the medullary internal surface occurred in the inner region, with the bone being alamellar, that is, constituted of collagen fibers less maturated than the lamellar bone. The CT scans showed no space between the material surface and the bone at the implant/bone marrow interface, and the density of the tissues at this interface was similar to the density measured in the other regions of the bone marrow. The bone remodeling process observed histologically was accompanied by positive modulation of MMP-2 during the entire evaluation period and low MMP-9 expression.

Em uma parcela permanente de 10,24 ha na Floresta Pluvial Atlântica Submontana do Parque Estadual Carlos Botelho (Sete Barras, SP, Brasil), este estudo teve o intuito de descrever o regime de distúrbio do dossel e avaliar a regeneração natural sob diferentes regimes de luz. Para tanto, foi realizado o levantamento de todas as clareiras da parcela, que foram mensuradas e tiveram sua idade aproximada estimada. Em seguida, foram instaladas 42 parcelas de 10x10m para avaliar a regeneração natural em três regimes luminosos: dossel contínuo (18 parcelas), clareiras pequenas a médias (11) e clareiras grandes com abundância de Guadua tagoara (Nees) Kunth (13). O regime de luz foi caracterizado por fotografias hemisféricas tomadas ao centro das parcelas. O estudo da regeneração natural foi divido em: estrato herbáceo (i.e., ervas menores que um metro de altura), avaliado através da cobertura do solo estimada pelo método de interceptação de linha; e estrato arbustivo, avaliado através dos indivíduos com altura maior que 1m, e com diâmetro à altura do peito menor que 5cm. Para estes indivíduos anotou-se a espécie, diâmetro, altura total e área de copa, além da presença de partes reprodutivas e substrato de germinação. Informações sobre hábito, grupo sucessional e síndrome de dispersão das espécies também foram obtidas. Após um ano, uma reavaliação permitiu analisar a mortalidade, danos, recrutamento e crescimento. Apesar de 67% das clareiras terem sido menores que 150 m2 , o regime de distúrbio foi atípico, principalmente pela contribuição de clareiras maiores que 750 m2 , e pela área média e total que variaram respectivamente de 419 a 799 m2 , e de 26 a 49%, dependendo do método de delimitação de clareira. A densidade foi de 6 clareiras.ha -1 e a taxa de recorrência variou entre 91 e 220 anos, dependendo dos métodos. Houve diferença significativa entre os ambientes para a maioria dos índices de luz, especialmente para a radiação total incidente com médias entre 909 e 2.400 mols.m-2.ano-1. Observou-se diferença significativa entre ambientes na cobertura por ervas, porém os resultados variaram entre espécies. No estrato arbustivo, houve diferença significativa na composição e abundância das espécies, inclusive entre clareiras médias e sub-bosque. A densidade de ervas e arbustos foi maior nos ambientes mais iluminados, assim como a densidade de pioneiras e secundárias iniciais. O recrutamento em um ano (16%) apresentou diferenças nos ambientes, com 63% dos recrutas apenas nas grandes clareiras. O mesmo não ocorreu com a taxa de mortalidade cujas principais causas foram os danos físicos e dessecamento. Para os 13% de indivíduos danificados em um ano, houve destaque para danos ligados à extração de palmito. Apenas os danos físicos naturais apresentaram diferença entre ambientes, com grandes clareiras sendo as mais danosas. No geral e entre as 25 espécies avaliadas separadamente, houve uma tendência de crescimento maior com o aumento da incidência luminosa. Clareiras pequenas a médias tiveram significativamente maior riqueza, diversidade e menor dominância de espécies que o sub-bosque. Clareiras grandes com bambu tiveram menor riqueza e diversidade, mas contribuíram com a manutenção da diversidade beta da parcela permanente. / In a 10.24 ha permanent plot of Tropical Lower Montane Atlantic Rain Forest in the Carlos Botelho State Park (Sete Barras, SP, Brazil), this study aimed to describe the canopy disturbance regime and to assess natural regeneration under different light regimes. In order to do so, the plot was completely surveyed for canopy gaps that were measured and had their approximate age estimated. Then, 42 10x10 m plots were established to evaluate natural regeneration under three light regimes: understory (18 plots), small to medium canopy gaps (11 plots) and large gaps abundant in Guadua tagoara (Nees) Kunth (13 plots). The light regime was characterized through hemispherical photographs taken at each plot center. Natural regeneration was dived into: herb stratum (i.e., herbs below one meter in height) assessed through soil coverage using the line intercept method; and shrub stratum or all plant individuals taller than one meter high and thinner than 5 cm in diameter at breast height. All individuals were identified to species and measured for diameter, height, crown height and area, besides notes on the presence of reproductive structures and germination substrate. Information on growth form, dispersal syndrome and ecological group were also obtained for each species. After one year, one reevaluation was made to assess mortality, damages, recruitment and growth. Although 67% of gaps were smaller than 150 m2 , the plot disturbance regime was atypical mainly by the contribution of gaps bigger than 750 m2 and by the average and total gap area that varied respectively from 419 to 799 m2 , and from 26 to 49% depending on the gap delimitation method. Gap density was 6 gaps.ha-1 and the turnover rate varied from 91 to 220 years depending on the gap method employed. There was significant difference between environments among the light index, especially for total incident radiation with means varying from 909 and 2,400 mols.m-2.y-1. It was found significant differences on herb soil coverage between environments, although the results varied among species. In the shrub stratum, species composition and abundance was significantly different, even between small to medium canopy gaps and the understorey. Herb and shrub densities were bigger in the more enlightened environments, as well as pioneer and early secondary species densities. Recruitment over the year (16%) was different between environments with large gaps accounting for 63% of all recruits. Similar difference was not found for mortality rate that had physical damage and desiccation as main death causes. Amid the 13% of damage individuals in the course of one year, there was noticeable contribution of damages linked to illegal extraction of palm-heart. Differences between environments were present only for physical damages with large gaps being the most damaging environment. In general and among the 25 species evaluated separately, there was a tendency of bigger growth with enhancement in light incidence. Small to medium gaps had significantly higher species richness and diversity, and lower dominance compared to the understorey. Large gaps had lower richness and diversity, but they contributed to maintain beta diversity of the permanent plot.

L'esca est un syndrome cryptogamique vasculaire de la vigne (Vitis vinifera). Une phase pionnière, sous la dépendance de Phaeoacremonium aleophilum (PA), Phaeomoniella chlamydospora (PC) et éventuellement de Eutypa lata (EL) permet la mise en place d'autres espèces. Depuis l'interdiction de l'arsénite de sodium, cette maladie n'est plus contrôlée.<br /> Nous avons étudié les propriétés de PA, PC et EL, en particulier l'impact sur leur croissance de fongicides commerciaux et de fongicides systémiques synthétisés au laboratoire, ainsi que de molécules naturelles. Ces pathogènes ne présentent pas la même sensibilité à ces molécules et l'un d'eux (PA) est peu affecté par divers traitements. En parallèle, nous avons étudié les propriétés d'ambimobilité de l'acide salicylique (AS) et de quelques-uns de ses dérivés halogénés.<br /> Nous avons montré que F 30, un dérivé acide du fenpiclonil, est mobile dans les boutures de vigne après application foliaire. Il est en partie retenu dans le bois et libère la molécule parent dans les racines. L'acide 5-chlorosalicylique (5-ClAS), connu pour être plus actif que AS pour stimuler les défenses naturelles, présente une mobilité voisine de celle de AS. Sur ces bases, F 30 et 5-ClAS ont été retenus pour des tests préliminaires de traitement par voie foliaire de boutures de vigne infectées.<br /> Cette recherche exploratoire souligne la complexité de la problématique, une lutte chimique (fongicide), génératrice de contraintes, devant s'intégrer dans une stratégie globale de contrôle.

Le puceron du soya (Aphis glycines) est le ravageur le plus important de la culture du soya en Amérique du Nord. Quoi qu’efficaces, les pesticides permettent le contrôle des ravageurs que pour une courte période et nécessitent plusieurs applications au cours de la saison. De plus, ils sont dommageables pour l’environnement et la santé humaine. La lutte biologique se présente comme une alternative crédible pour le contrôle des populations d’A. glycines en Amérique du Nord. Trois parasitoïdes (Binodoxys communis, Aphidius colemani, Aphelinus certus) du puceron semblent être des candidats prometteurs. L’objectif de cette étude était d’examiner certains attributs biologiques de ces parasitoïdes au Québec. Dans le cas de B. communis et A. certus nous avons estimé leur synchronisme saisonnier ainsi que leur résistance au froid en laboratoire et en conditions naturelles. Dans le cas, d’A. colemani, nous avons évalué sa capacité à parasiter le puceron du soya et à se disperser dans un champ de soya. Nos résultats démontrent que la souche utilisée de B. communis a perdu sa capacité à entrer en diapause, probablement à cause de la longue période d’élevage en laboratoire qui a suivi son échantillonnage en Asie. Aphelinus certus démontre un potentiel intéressant puisqu’il possède un synchronisme saisonnier tant en automne qu’au printemps avec son hôte ainsi qu’un bon potentiel de survie hivernale au Québec. Quant à A. colemani, les essais suggèrent qu’il se disperse rapidement hors des champs sans attaquer de manière significative A. glycines. / The soybean aphid (Aphis glycines) has become the most important pest of soybean in North America. Despite their efficiency, insecticides do eliminate the pest only for short periods and several applications may be required during the growing season. Furthermore, they are detrimental for the environment and human health. Biological control appears as a promising alternative for the control of A. glycines populations in North America. Three parasitoid species (Binodoxys communis, Aphidius colemani, Aphelinus certus) have been identified as potential candidates. The objective of this study was to study some biological attributes of these parasitoids in Québec. For B. communis and A. certus we examined their seasonal activities and their cold hardiness in laboratory and natural conditions. For A. colemani, we evaluated its capacity to parasite the soybean aphid and to disperse in soybean fields. Our results revealed that the B. communis strain we used had lost its capacity to enter diapause, probably due to the long period of laboratory rearing following its sampling in Asia. Aphelinus certus showed an interesting potential because the species is synchronized with its host both in the fall and the spring and has the capacity to overwinter in Québec. For A. colemani, the essays suggest that it disperses rapidly out of the field without attacking significantly A. glycines.

Em uma parcela permanente de 10,24 ha na Floresta Pluvial Atlântica Submontana do Parque Estadual Carlos Botelho (Sete Barras, SP, Brasil), este estudo teve o intuito de descrever o regime de distúrbio do dossel e avaliar a regeneração natural sob diferentes regimes de luz. Para tanto, foi realizado o levantamento de todas as clareiras da parcela, que foram mensuradas e tiveram sua idade aproximada estimada. Em seguida, foram instaladas 42 parcelas de 10x10m para avaliar a regeneração natural em três regimes luminosos: dossel contínuo (18 parcelas), clareiras pequenas a médias (11) e clareiras grandes com abundância de Guadua tagoara (Nees) Kunth (13). O regime de luz foi caracterizado por fotografias hemisféricas tomadas ao centro das parcelas. O estudo da regeneração natural foi divido em: estrato herbáceo (i.e., ervas menores que um metro de altura), avaliado através da cobertura do solo estimada pelo método de interceptação de linha; e estrato arbustivo, avaliado através dos indivíduos com altura maior que 1m, e com diâmetro à altura do peito menor que 5cm. Para estes indivíduos anotou-se a espécie, diâmetro, altura total e área de copa, além da presença de partes reprodutivas e substrato de germinação. Informações sobre hábito, grupo sucessional e síndrome de dispersão das espécies também foram obtidas. Após um ano, uma reavaliação permitiu analisar a mortalidade, danos, recrutamento e crescimento. Apesar de 67% das clareiras terem sido menores que 150 m2 , o regime de distúrbio foi atípico, principalmente pela contribuição de clareiras maiores que 750 m2 , e pela área média e total que variaram respectivamente de 419 a 799 m2 , e de 26 a 49%, dependendo do método de delimitação de clareira. A densidade foi de 6 clareiras.ha -1 e a taxa de recorrência variou entre 91 e 220 anos, dependendo dos métodos. Houve diferença significativa entre os ambientes para a maioria dos índices de luz, especialmente para a radiação total incidente com médias entre 909 e 2.400 mols.m-2.ano-1. Observou-se diferença significativa entre ambientes na cobertura por ervas, porém os resultados variaram entre espécies. No estrato arbustivo, houve diferença significativa na composição e abundância das espécies, inclusive entre clareiras médias e sub-bosque. A densidade de ervas e arbustos foi maior nos ambientes mais iluminados, assim como a densidade de pioneiras e secundárias iniciais. O recrutamento em um ano (16%) apresentou diferenças nos ambientes, com 63% dos recrutas apenas nas grandes clareiras. O mesmo não ocorreu com a taxa de mortalidade cujas principais causas foram os danos físicos e dessecamento. Para os 13% de indivíduos danificados em um ano, houve destaque para danos ligados à extração de palmito. Apenas os danos físicos naturais apresentaram diferença entre ambientes, com grandes clareiras sendo as mais danosas. No geral e entre as 25 espécies avaliadas separadamente, houve uma tendência de crescimento maior com o aumento da incidência luminosa. Clareiras pequenas a médias tiveram significativamente maior riqueza, diversidade e menor dominância de espécies que o sub-bosque. Clareiras grandes com bambu tiveram menor riqueza e diversidade, mas contribuíram com a manutenção da diversidade beta da parcela permanente. / In a 10.24 ha permanent plot of Tropical Lower Montane Atlantic Rain Forest in the Carlos Botelho State Park (Sete Barras, SP, Brazil), this study aimed to describe the canopy disturbance regime and to assess natural regeneration under different light regimes. In order to do so, the plot was completely surveyed for canopy gaps that were measured and had their approximate age estimated. Then, 42 10x10 m plots were established to evaluate natural regeneration under three light regimes: understory (18 plots), small to medium canopy gaps (11 plots) and large gaps abundant in Guadua tagoara (Nees) Kunth (13 plots). The light regime was characterized through hemispherical photographs taken at each plot center. Natural regeneration was dived into: herb stratum (i.e., herbs below one meter in height) assessed through soil coverage using the line intercept method; and shrub stratum or all plant individuals taller than one meter high and thinner than 5 cm in diameter at breast height. All individuals were identified to species and measured for diameter, height, crown height and area, besides notes on the presence of reproductive structures and germination substrate. Information on growth form, dispersal syndrome and ecological group were also obtained for each species. After one year, one reevaluation was made to assess mortality, damages, recruitment and growth. Although 67% of gaps were smaller than 150 m2 , the plot disturbance regime was atypical mainly by the contribution of gaps bigger than 750 m2 and by the average and total gap area that varied respectively from 419 to 799 m2 , and from 26 to 49% depending on the gap delimitation method. Gap density was 6 gaps.ha-1 and the turnover rate varied from 91 to 220 years depending on the gap method employed. There was significant difference between environments among the light index, especially for total incident radiation with means varying from 909 and 2,400 mols.m-2.y-1. It was found significant differences on herb soil coverage between environments, although the results varied among species. In the shrub stratum, species composition and abundance was significantly different, even between small to medium canopy gaps and the understorey. Herb and shrub densities were bigger in the more enlightened environments, as well as pioneer and early secondary species densities. Recruitment over the year (16%) was different between environments with large gaps accounting for 63% of all recruits. Similar difference was not found for mortality rate that had physical damage and desiccation as main death causes. Amid the 13% of damage individuals in the course of one year, there was noticeable contribution of damages linked to illegal extraction of palm-heart. Differences between environments were present only for physical damages with large gaps being the most damaging environment. In general and among the 25 species evaluated separately, there was a tendency of bigger growth with enhancement in light incidence. Small to medium gaps had significantly higher species richness and diversity, and lower dominance compared to the understorey. Large gaps had lower richness and diversity, but they contributed to maintain beta diversity of the permanent plot.

O objetivo deste estudo foi analisar a modulação da expressão de metaloproteinases da matriz-2 e -9, no tecido ósseo neoformado na interface do implante derivado do polímero da mamona (Ricinus communis) com o canal medular da tíbia de coelhos, por meio de análise histológica por microscopia óptica, tomografia computadorizada e imunoistoquímica. Foram selecionados 44 coelhos machos, Oryctolagus cuniculus, da linhagem Nova Zelândia, albinos, divididos em dois grupos, sendo o Grupo 1, composto por 12 animais controle, cujas fresagens do canal medular foram produzidas bilateralmente nas tíbias e não preenchidas e, o Grupo 2, com 30 animais, cujos canais medulares da tíbia, após fresagem, foram preenchidos bilateralmente com os cilindros derivados da poliuretana da mamona. Os animais do Grupo 1 e Grupo 2 foram divididos aleatoriamente em subgrupos experimentais, conforme as datas de eutanásia pré-determinadas em 90, 120, 150 dias após o ato operatório. Um animal não foi submetido ao procedimento de fresagem, sendo utilizado para controle histológico e outro submeteu-se à eutanásia após o implante do polímero, sendo utilizado para controle de imagem do estudo com tomografia computadorizada. Decorridos os períodos experimentais, os animais foram submetidos à eutanásia, as peças removidas e encaminhadas para o exame tomográfico; posteriormente ao processamento histológico, as lâminas foram analisadas em microscópio óptico. As Metaloproteinases da Matriz (MMPs) são um importante grupo de enzimas proteolíticas zinco-dependentes responsáveis pela degradação de matriz extracelular e membranas basais. As enzimas são secretadas em uma forma latente e se tornam ativadas no ambiente pericelular, sendo relacionadas a processos fisiológicos e patológicos. No presente estudo, foram revisados alguns aspectos importantes das MMPs, discutindo-se o papel dessas enzimas em processos fisiológicos como a neoformação e maturação óssea (MMP-2). Dentre os processos patológicos que envolvem a participação das MMPs, destacam-se a reabsorção óssea e processos inflamatórios (MMP-9). A expressão de metaloproteinase da matriz-2 e -9 nos tecidos foi avaliada por meio de imunoistoquímica. Os dados obtidos foram submetidos à análise estatística por meio do teste ANOVA seguido pelo pós-teste de Tukey (&alpha; = 0,05). No grupo experimental, aos 90 dias, a interface com o polímero apresentava uma camada espessa de tecido ósseo neoformado rico em osteócitos, o qual apresentou uma maturação com o passar do tempo, aos 120 e 150 dias pós-implantação. No grupo controle, a superfície interna junto ao canal medular apresentava-se revestida por osteoblastos, seguida de faixa de tecido ósseo, com poucas lacunas preenchidas por osteócitos. O amadurecimento do tecido da superfície interna medular acontece na região interior, sendo o osso alamelar, constituído por fibras colágenas menos amadurecidas que o osso lamelar. As imagens tomográficas demonstraram não haver espaço entre a superfície do material e do osso na interface implante/medula óssea, sendo a densidade dos tecidos nesta interface semelhante à densidade das demais porções da medula óssea. O processo de remodelação óssea observado histologicamente foi acompanhado pela modulação positiva de metaloproteinase da matriz-2 durante todo o período de avaliação com baixa expressão de metaloproteinase da matriz-9. / The aim of this study was to evaluate the modulation of matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9) expression in newly formed bone tissue at the interface between implant derived from castor oil (Ricinus communis) polymer and the medullary canal of rabbit tibia, by histological examination under optical microscopy, computed tomography (CT) and immunohistochemical analysis. For such purpose, 44 rabbits (Oryctolagus cuniculus, New Zealand, albinus) were selected and assigned to two groups. In Group 1, composed of 12 animals (control), reamings of the medullary canal were produced bilaterally in the tibiae of the rabbits and were not filled. In Group 2, composed of 30 animals, the tibial medullary canals, after reaming, were filled bilaterally with cylinders derived from castor oil polyurethane. The animals of Groups 1 and 2 were randomly divided in experimental subgroups, according to the periods of predetermined euthanasia, which were 90, 120, 150 days postoperatively. One animal was not subjected to the reaming procedure, and served as a histological control; another animal was killed after placement of the polymer implant, and served as a control for CT imaging. Euthanasia was undertaken at the established experimental periods, and the anatomic specimens were removed and subjected to CT analysis. Then, after histological processing, the slides were examined under optical microscopy. MMPs are an important group of zinc-dependent proteolytic enzymes responsible for the degradation of extracellular matrix and basal membranes. The enzymes are synthesized in a latent form and are activated in the pericellular environment, being involved in physiological and pathological processes. In the present study, some important aspects of MMPs were reviewed, and the role of these enzymes in physiological processes, such as new bone formation and bone maturation (MMP-2), was discussed. Among the pathological processes that have the participation of MMPs, the most relevant are bone resorption and inflammatory processes (MMP-9). MMP-2 and MMP-9 expression in the tissues was evaluated by immunohistochemistry. Data were subjected to statistical analysis by ANOVA and Tukey post-test (&alpha; = 0.05). In the group experimental, at 90 days, the interface with the polymer presented a thick layer of newly formed bone tissue rich in osteocytes. This tissue exhibited an ongoing maturation at 120 and 150 days post-implantation. In the control group, the internal surface close to the medullary canal was lined by osteoblasts, followed by a bone tissue zone with few lacunae filled with osteocytes. Maturation of the tissue of the medullary internal surface occurred in the inner region, with the bone being alamellar, that is, constituted of collagen fibers less maturated than the lamellar bone. The CT scans showed no space between the material surface and the bone at the implant/bone marrow interface, and the density of the tissues at this interface was similar to the density measured in the other regions of the bone marrow. The bone remodeling process observed histologically was accompanied by positive modulation of MMP-2 during the entire evaluation period and low MMP-9 expression.

Corynebacterium diphtheriae, Pseudomonas aeruginosa, Ricinus communis, Shigella dysentariae, and Vibrio cholerae produce AB toxins which share the same basic structural characteristics: a catalytic A subunit attached to a cell-binding B subunit. All AB toxins have cytosolic targets despite an initial extracellular location. AB toxins use different methods to reach the cytosol and have different effects on the target cell. Broad-spectrum inhibitors against these toxins are therefore hard to develop because they use different surface receptors, entry mechanisms, enzyme activities, and cytosolic targets. We have found that grape seed extract provides resistance to five different AB toxins: diphtheria toxin (DT), P. aeruginosa exotoxin A (ETA), ricin, Shiga toxin, and cholera toxin (CT). To identify individual compounds in grape seed extract that are capable of inhibiting the activities of these AB toxins, we screened twenty common phenolic compounds of grape seed extract for anti-toxin properties. Three compounds inhibited DT, four inhibited ETA, one inhibited ricin, and twelve inhibited CT. Additional studies were performed to determine the mechanism of inhibition against CT. Two compounds inhibited CT binding to the cell surface and even stripped bound CT off the plasma membrane of a target cell. Two other compounds inhibited the enzymatic activity of CT. We have thus identified individual toxin inhibitors from grape seed extract and some of their mechanisms of inhibition against CT. This work will help to formulate a defined mixture of phenolic compounds that could potentially be used as a therapeutic against a broad range of AB toxins.

This essay is an examination of the examples in Kant’s Critique of Judgement. The examples which I have focused on all converge in an idea of wildness. These examples of the beautiful are illuminated by a culture-historical perspective, where the literary and scientific travelogue genre is of great importance. Apart from being exegetic and culture historical, my method is also analytic. The general ambition is to answer the question; what is the parrot doing in the third Critique and what makes it a better example of a free beauty than a jackdaw? Taking as point of departure Jacques Derrida’s notion of parergonality, the example is primarily understood as formative for the thesis, not only as illustrative. By analysing Kant’s use of the wild, exotic and colourful objects as examples the essay intends to show how imagination and understanding operates in the beautiful. The parrot thus corresponds with the role of imagination in its relation to understanding in aesthetic judgement. The examples manifest the strength of the imagination and how it dominates understanding through its wildness. The aim is to present a way to approach the restful contemplation that Kant ascribes to the mind in the experience of the beautiful as bearer of a movement with considerable importance. Rodolphe Gasché’s emphasis on the wild examples as a precognitive minimum for understanding and Hannah Arendt’s view on imagination as an ability of intuition without the presence of the object, have also been essential for my argument.