Made available in DSpace on 2014-06-11T19:22:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-25Bitstream added on 2014-06-13T19:27:11Z : No. of bitstreams: 1 soranzfilho_je_me_botfm.pdf: 1652118 bytes, checksum: 7a01edbccd06925523118f49c1d42b63 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Universidade Estadual Paulista (UNESP) / Alterações oculares, em especial a perda de volume nas cavidades evisceradas, promovem uma série de modificações ao paciente tanto funcional do órgão quanto psicológica e estética. Uma grande preocupação ao longo do tempo é a procura de um material que possa preencher o volume perdido de forma a dar um maior conforto no ponto de visto psicológico e estético ao paciente. Para contribuir nessa direção, esse trabalho teve como objetivo testar experimentalmente prótese de polietileno granulado de ultra-alto peso molecular, material de baixo custo, em órbitas de coelhos submetidos à evisceração cirúrgica em vários tempos experimentais, onde foram avaliados aspectos macroscópicos e microscópicos e de toxicidade sistêmica do material. Os resultados desse trabalho mostram que o material utilizado no implante de cavidade não apresenta alteração significativa nos parâmetros analisados quando comparados ao grupo controle. Sendo resultados bastante promissores indicando que o implante de polietileno poroso desenvolvido por uma indústria nacional tem alto potencial para se realizar testes em humanos / Ocular changes especially the loss of volume in eviscerated cavities promotes several modifications to patients – organ functioning and psychological and esthetical changes. A material that could replace the lost volume in order to guarantee to patients more psychological and esthetical comfort has long been worryingly searched. Contributing in this direction this work aimed at testing experimentally a prosthesis polyethylene granulate of ultra-high molecular weight made of a low cost material to be implanted in orbit of rabbits through surgical evisceration during several experimental times to assess macroscopic and microscopic aspects of systemic toxicity of the respective material. The results show that the material used for the implant of the prosthesis in the cavity does not present significant alteration in the analysed parameters when compared to the control group. Thus, we point with this study promising results indicating that the porous polyethylene implant developed by a national enterprise presents high potential to be tested in humans

The Lower Keys marsh rabbit (LKMR, Sylvilagus palustris hefneri), a subspecies of marsh rabbit endemic to the Lower Keys, Florida, is threatened with extinction due to extensive coastal development of salt marsh habitats. LKMR recovery is limited by habitat loss and degradation from brush encroachment, predation by freeroaming cats (Felis catus) and raccoons (Procyon lotor), sea-level rise, and hurricanes. This study sought to determine local and landscape factors that influence LKMR metapopulation ecology and dynamics and to evaluate strategies for their recovery. I evaluated the influence of patch and landscape characteristics on LKMR densities, extinction, and colonization rates following Hurricane Wilma, and the response of LKMRs and salt marsh habitats to prescribed fire. I used estimates of population change based on annual monitoring data to validate vital rates, constructed a spatially explicit demographic model to evaluate various levels and spatial configurations of recovery scenarios implemented throughout the LKMRs range, and validated expected changes in parameter estimates using measures of habitat degradation and raccoon activity from known LKMR populations. I found LKMR densities were higher in patches with greater numbers of bunchgrasses and forbs and less edge and lower in patches with higher measures of raccoon activity. In response to a hurricane, I found the distance between LKMR patches and the coast had a negative influence on extinction probability; the distance between an extirpated and occupied LKMR patch had a negative influence on colonization probability and patch size had a positive influence. Adult LKMRs increased as woody cover <0.5 m decreased, herbaceous cover <0.5 m increased, and food availability increased in at least one site following prescribed fire. Model results indicated habitat management actions that improve carrying capacity of local rabbit populations and juvenile survival and control raccoon populations to increase rabbit reproductive rates are effective population recovery strategies. In total, my results provide a conservation planning tool that can be used to select recovery strategies and locations that will maximize benefits to LKMRs, thus improving their viability and recovery.

Originally pub. as thesis--Universität Giessen, 2005. / Edition scientifique. Includes bibliographical references and index.

Background. A visual prosthesis is a conceptual device designed to activate residual functional neurons in the visual pathway of blind individuals to produce artificial vision. Such device, when applied to stimulate the vitreous surface of the retina, has proven feasible in producing patterned light perception in blind individuals suffering from dystrophic diseases of the retina, such as aged-related macular degeneration (AMD). However the practicality of such approach has been challenged by the difficulty of surgical access and the risks of damaging the neuroretina. Positioning a visual implant over the scleral surface of the eye could present a safer alternative but this stimulation modality has not been tested in diseased retinas. Additionally, recent research has shown that the adult neocortex retains substantial plasticity following a disruption to its visual input and the potential deterioration in visual capabilities as a result of such experience modification may undermine the overall bionic rescue strategy. Methods. Two animal models mimicking the principal pathologies found in AMD, namely photoreceptor degeneration and reduced retinal ganglion cell mass, were used to evaluate the efficacy of trans-scleral stimulation of the retina by recording electrical evoked potentials in the visual cortex. The visual performance following the loss of pattern vision induced by bilateral eyelid suturing in adult mice was examined by analysing visual evoked potentials. Findings. Spatially differentiated cortical activations were obtained notwithstanding the underlying retinopathy in the experiment animals. The charge density thresholds were found to be similar to controls and below the bioelectric safety limit. After prolonged visual deprivation (weeks) in the mouse, the visual cortical responses evoked by either electrical or photic stimuli were both significantly reduced. An assessment of different visual capabilities using patterned stimuli demonstrated that whilst visual acuity and motion sensitivity were preserved, significant depression in luminance and contrast sensitivities was detected. Conclusion. Trans-scleral stimulation of the retina is a feasible approach for the development of a visual prosthesis. Following visual loss the adult brain exhibits significant experience-dependent modifications. These new insights may force a revision on the current bionic rescue strategy.

Background. A visual prosthesis is a conceptual device designed to activate residual functional neurons in the visual pathway of blind individuals to produce artificial vision. Such device, when applied to stimulate the vitreous surface of the retina, has proven feasible in producing patterned light perception in blind individuals suffering from dystrophic diseases of the retina, such as aged-related macular degeneration (AMD). However the practicality of such approach has been challenged by the difficulty of surgical access and the risks of damaging the neuroretina. Positioning a visual implant over the scleral surface of the eye could present a safer alternative but this stimulation modality has not been tested in diseased retinas. Additionally, recent research has shown that the adult neocortex retains substantial plasticity following a disruption to its visual input and the potential deterioration in visual capabilities as a result of such experience modification may undermine the overall bionic rescue strategy. Methods. Two animal models mimicking the principal pathologies found in AMD, namely photoreceptor degeneration and reduced retinal ganglion cell mass, were used to evaluate the efficacy of trans-scleral stimulation of the retina by recording electrical evoked potentials in the visual cortex. The visual performance following the loss of pattern vision induced by bilateral eyelid suturing in adult mice was examined by analysing visual evoked potentials. Findings. Spatially differentiated cortical activations were obtained notwithstanding the underlying retinopathy in the experiment animals. The charge density thresholds were found to be similar to controls and below the bioelectric safety limit. After prolonged visual deprivation (weeks) in the mouse, the visual cortical responses evoked by either electrical or photic stimuli were both significantly reduced. An assessment of different visual capabilities using patterned stimuli demonstrated that whilst visual acuity and motion sensitivity were preserved, significant depression in luminance and contrast sensitivities was detected. Conclusion. Trans-scleral stimulation of the retina is a feasible approach for the development of a visual prosthesis. Following visual loss the adult brain exhibits significant experience-dependent modifications. These new insights may force a revision on the current bionic rescue strategy.

Thesis (Ph. D.)--Washington State University, August 2008. / Includes bibliographical references.

Vegetable products, antioxidants help the body resistance in various pathological conditions, especially those associated with aging, cancer and cardiovascular diseases, and so are classified as agent quimioprotetores. The antioxidant properties of some phenolic compounds such as leucoantocianidina already have a proven action in respect of the reduction of cholesterol, however, to quantify the reduction of atherosclerosis were no reports. Thus, this study aims to examine the effectiveness of grape leucoantocianidina reduction in experimental atherosclerotic plaque in rabbits. We used New Zealand rabbits (n = 27) adults from 7 to 8 months of age divided into 3 groups: control group with 200 g feed water ad libitum (G1), group with feed 200g, 1.5 g cholesterol + 10 ml of yolk (G2), group with feed 200g, 1.5 g cholesterol + 10 ml of yolk and treated with 50mg/kg of leucoantocianidina grape (G3). All groups were fed during 100 days, aiming to replicate the model of induced atherosclerosis in New Zealand albino rabbits; assess the effects of grape leucoantocianidina for: total cholesterol, LDL, HDL, VLDL, total lipids, triglycerides; leucoantocianidina Quantifying the effects of grape on the arterial subendothelial layer using the Program IMAGE-PRO-PLUS 4.5. Blood samples for measurements of lipid profiles of animals occurred at 0, 33, 66 and 99 days. At the end of the experiment, the animals were euthanized. Segments of the aortic arch, carotid artery and femoral artery (right and left) were collected for histopathological analysis. As expected the G1 did not observe change, G2 found a severe thickening of the subendothelial layer, the group G3 was thickening of the subendothelial layer, however, a less severe form compared to G2. Under the microscope, foam cells were observed in the aortic arch and no changes in the arteries, femoral and carotid artery thickening and endothelial G2 significantly compared to the G1. Leucoantocianidina grape was able to reduce 4.35% of the thickening of the subendothelial layer, was able to significantly reduce hepatic steatosis (macrovesicular and microvesicular), as well as the size of xanthomas arising distributed in the body of animals. Leucoantocianidina The grape does not change, in this experimental model of atherosclerosis in rabbits, the levels of total cholesterol, LDL, VLDL, HDL, triglycerides and total lipids significantly. / Fundação de Amparo a Pesquisa do Estado de Alagoas / Produtos vegetais antioxidantes auxiliam o corpo na resistência as várias condições patológicas, especialmente aquelas associadas com o envelhecimento, câncer e as doenças cardiovasculares, e por isso são classificados como agentes quimioprotetores. As propriedades antioxidantes de alguns compostos fenólicos como a leucoantocianidina já tem ação comprovada no que diz respeito na redução do colesterol, no entanto, na quantificação da redução da aterosclerose não encontramos relatos. Desta forma, o presente trabalho tem por objetivo analisar efeito da leucoantocianidina de uva na redução de placa aterosclerótica experimental em coelhos. Foram utilizados coelhos da Nova Zelândia (n=27) adultos entre 7 a 8 meses de idade divididos em 3 grupos: grupo controle com ração 200 g e água ad libitum (G1); o grupo com ração 200g, 1,5 g de colesterol + 10mL de gema (G2); grupo com ração 200g, 1,5 g de colesterol + 10mL de gema e tratado com 50mg/kg da leucoantocianidina de uva (G3). Todos os grupos foram alimentados durante o período de 100 dias, tendo como objetivo reproduzir o modelo de indução de aterosclerose em coelhos albinos Nova Zelândia; Verificar os efeitos da leucoantocianidina de uva sobre o: colesterol total, LDL, HDL, VLDL, lipídios totais, triglicerídeos; Quantificar os efeitos da leucoantocianidina de uva sobre a camada subendotelial arterial utilizando o Programa IMAGE-PRO-PLUS 4.5. A coleta de sangue para as dosagens do perfil lipídico dos animais aconteceram nos momentos 0, 33, 66 e 99 dias. Ao término do período experimental, os animais foram submetidos à eutanásia. Segmentos do arco aórtico, da artéria carótida e artéria femoral (direitas e esquerdas) foram coletados para análise histopatológica. Como esperado o grupo G1 não observou alteração, o grupo G2 verificamos um espessamento severo da camada subendotelial, o grupo G3 houve espessamento da camada subendoletial, no entanto, numa forma menos grave comparado com o grupo G2. Ao microscópio, foram observadas células espumosas no arco aórtico e sem alterações nas artérias: femoral e carótida e espessamento de endotélio no grupo G2 de forma significante comparando-os ao G1. A leucoantocianidina de uva foi capaz de reduzir 4,35 % do espessamento da camada subendotelial, foi capaz de reduzir forma significante a esteatose hepática (macrovesicular e microvesicular), bem como o tamanho dos xantomas que surgiram distribuídos nos corpo dos animais. A leucoantocianidina de uva não modifica, no presente modelo experimental de aterosclerose em coelhos, os níveis de colesterol total, LDL, VLDL, HDL, triglicerídeos e lipídeos totais de forma significante.

The endogenous development of the rabbit coccidium Eimeria exigua was studied by light and electron microscopy in coccidia-free rabbits.

Swamp rabbits (Sylvilagus aquaticus) in southern Illinois exist as a metapopulation due to loss and fragmentation of the bottomland hardwood forests in which they live, making their persistence in the state uncertain. I ran a spatially-explicit population viability analysis (PVA) on the metapopulation, using a habitat suitability map I created and life history parameters drawn from the literature. I varied parameters related to reproduction, survival, catastrophes, dispersal, and carrying capacity from 50 to 150% of the initial value of each parameter to compare their effects on extinction risk. I modified the map to test the effects of potential habitat loss, fragmentation, and the addition of dispersal corridors on the swamp rabbit metapopulation in southern Illinois. Under baseline conditions, the model suggested about a 20% chance of quasi-extinction (90% metapopulation decline) in 25 years. Changes in fecundity values and the effects of catastrophic flooding had the greatest effect on the risk of extinction, causing quasi-extinction probabilities to range from 0 to 100% and 0 to 87%, respectively. In contrast, changing dispersal values yielded the least impact on the risk of extinction (18-24%), and all other parameters had moderate impacts on the model. Removing groups of the largest habitat patches increased the risk of extinction, whereas removing groups of the smallest habitat patches decreased the risk of extinction, suggesting that small patches could act as population sinks with a negative impact on swamp rabbit persistence. Decreasing patch fragmentation per se reduced the risk of extinction slightly. The addition of dispersal corridors made no significant impact on the probability of extinction. My findings indicate that more research estimating fecundity and the effect of catastrophic floods on swamp rabbits in Illinois is required to more accurately predict swamp rabbit persistence in the state. I also suggest that managers should work to decrease the effect of flooding on the population by improving upland habitat, or decrease fragmentation by increasing the area of bottomland hardwood forests around existing habitat patches. Lastly, I suggest managers focus on preventing further habitat fragmentation into small patches, which will mitigate the creation of potential sink populations and will enable current populations to persist.

Made available in DSpace on 2014-06-11T19:23:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-09-24Bitstream added on 2014-06-13T19:07:17Z : No. of bitstreams: 1 friolani_m_me_jabo.pdf: 537940 bytes, checksum: e1d3c28c94d98d18c841491512109b44 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Tendo em vista as propriedades de aceleração do processo cicatricial com utilização da biomembrana de látex, este trabalho teve como objetivo avaliar o comportamento de retalho de biomembrana natural de látex, em lesões diafragmáticas induzidas experimentalmente em coelhos. Utilizaram-se 15 coelhos sadios, raça Nova Zelândia, adultos, machos e fêmeas, tendo como acesso ao diafragma, o 8º espaço intercostal direito. Os animais foram divididos, aleatoriamente, em cinco grupos experimentais de três cada, e avaliados diariamente desde o dia da cirurgia até a eutanásia, quanto ao comportamento, freqüência respiratória e cardíaca, cicatrização externa. Os animais foram eutanasiados aos 15, 30, 45, 60 e 90 dias de pós cirúrgico, obtendo-se uma avaliação macroscópica e microscópica do conjunto diafragma/enxerto. Todos os animais apresentaram evolução clínica satisfatória. Macroscopicamente, em todos os grupos experimentais observou-se boa cicatrização na região do implante, com exceção de um dos animais eutanasiados aos quinze dias. Após quinze dias, houve neoformação tecidual, e após trinta dias do ato operatório, em todos animais observou-se aderência do fígado e do pulmão na área de implante. As observações clínico-cirúrgicas complementadas pela análise das alterações histológicas, permitiram concluir pela indicação do emprego da membrana de látex em lesões diafragmáticas reparadoras, em razão da facilidade de obtenção, custo baixo, fácil aplicabilidade, resistência e resposta satisfatória em relação ao tempo de cicatrização. / Having in mind the acceleration properties of the cicatricial process by using the latex bio-membrane, the present paper was aimed at evaluating the behavior of the natural latex bio-membrane flap in diaphragmatic lesions experimentally induced in rabbits. Fifteen healthy New Zealand rabbits, adults, males and females were used, having the eighth right intercostal space as an access to the diaphragm. The animals were randomly assigned to five experimental groups, each with three rabbits. They were evaluated daily from the day of surgery to the day of euthanasia in relation to behavior, respiratory and cardiac frequencies and external cicatrization. The animals were euthanized in 15, 30, 45, 60 and 90 days after the surgery and it was obtained a macroscopic and microscopic evaluation of the set diaphragm/graft. All rabbits presented a satisfactory clinical evolution. Macroscopically, in all experimental groups it was observed a good cicatrization of the implant region, except for one animal that was euthanized in 15 days. After fifteen days, there was tissular neo-formation and thirty days after surgery in all animals it was observed the adherence of the liver and lungs in the implant area. The clinical surgical observations complemented by the analysis of histological alterations allowed the conclusion in favor of the indication of using the latex membrane in reparative diaphragmatic lesions because of the easy obtainment, low cost, easy applicability, resistance, and satisfactory response in relation to the cicatrization time.