Os efeitos da obstrução uretral parcial na musculatura da bexiga urinária de coelhos foram investigadas usando as ferramentas estereológicas. Foram utilizadas 12 fêmeas de coelhos da raça Norfolk, com três meses de idade e peso corporal variando de 2,5-3,0 kg. O procedimento cirúrgico consistiu de celiotomia mediana retro-umbilical para exposição da bexiga urinária. A parede dorsal da uretra foi divulsionada de sua íntima associação com o útero e vagina, o suficiente para a passagem de fio nylon 2-0. Um pino de Steinmann (3 mm de diâmetro) foi interposto temporariamente entre a uretra e o fio para determinar indiretamente o grau de obstrução uretral. Após três, sete e doze semanas os animais foram ortotanasiados e comparados com o grupo de animais controle (não obstruídos). Os fragmentos da bexiga foram preparados para microscopia de luz. Cortes seriados foram realizados para o estudo morfométrico e estereológico. Os três eixos: crânio-caudal (CC), dorso-ventral (DV) e latero-lateral (LL) aumentaram em todos os grupos analisados: controle, 3, 7 e 12 semanas. Os valores para CC foram estatisticamente similares para 3, 7 e 12 semanas. O mesmo foi observado no eixo DV. Os valores para o eixo LL foram similares para os grupos de 7 e 12 semanas. O estudo morfométrico baseou-se em determinar o tamanho da fibra (área seccional) e comprimento da fibra muscular. Nos animais do grupo de 3, 7 e 12 semanas foi observado um aumento de 4,63x, 4,32x e 7,10x no tamanho celular e um decréscimo de 2,55x, 1,94x e 4,04x no comprimento da fibra muscular quando comparados ao grupo controle. O estudo estereológico baseou-se em estimar o volume referência (Vref), a densidade numérica (Nv), o número total de fibras musculares (N), a densidade de volume (Vv) e o volume da fibra muscular (Vn). O Vref apresentou um aumento de 11,07x, 7,98x e 31,7x quando comparado com o grupo controle. A densidade numérica (Nv) aumentou 0,06x e 0,05x para os grupos de 3 e 7 semanas, respectivamente, em relação ao grupo controle. O grupo de 12 semanas, no entanto, apresentou um decréscimo de 0,01x em comparação com o grupo controle. Os grupos de 3, 7 e 12 semanas apresentaram, respectivamente, um aumento de 0,81x, 12,56x e 38,43x em número total de células. A densidade de volume (Vv) para os grupos de 3, 7 e 12 semanas apresentou um aumento de 0,97x, 0,56x e 0,86x em relação ao grupo controle. E finalmente, o volume médio da fibra muscular apresentou um aumento de 0,62x, 0,81x e 0,82x, respectivamente para os animais de 3, 7 e 12 semanas. Os dois mecanismos: hipertrofia e hiperplasia ocorrem na bexiga urinária de coelhos, porém não sabemos a seqüência exata em que aparecem. / The effects of partial urethral obstruction on rabbit´s urinary bladder musculature were investigated using stereological designed methods. A total of 12 female Norfolk rabbits weighing from 2.5 to 3 kg were used. A retro-umbilical celiotomy was made to expose the urinary bladder. The urethra´s dorsal wall was isolated from its association with the uterus. A 3mm-Steinmann-pin was positioned on the urethra to produce a standard degree of obstruction and a ligature was tied up around it, using a 2-0 nylon silk. Three, seven and twelve weeks after the surgery procedures the rabbits were euthanised. Bladder fragments were prepared for light microscopy. Serial sections were performed to morphometric and stereological study. In relation to the bladder axis: cranio-caudal (CC), dorso-ventral (DV) and latero-lateral (LL) increased in all groups analysed: control, 3, 7 and 12 week-obstructed animals. Values for CC were statistically similar for 3, 7 and 12-week-obstructed groups. The same was observed for DV axis. The LL axis showed values statistically similar for 7 and 12-week-obstructed groups. The morphometric study was based on the muscle fibre size (sectional area) and the muscle fibre length. In 3, 7 and 12-week-obstructed animals, it was observed a 4.63, 4.32 and 7.10-fold cell size increase and a 2.55, 1.94 and 4.04-fold decrease in length, respectively, when compared to control group. As for the stereological study. Vref presented a 11.07, 7.98 and 31.7-fold increase when compared to control subjects. Numerical density (Nv) increased by 0.06 and 0.05 in 3 and 7-week-obstructed groups, respectively, in relation to control group. Twelve week-obstructed group. Presented however a 0.01x-decrease compared to control animals. Three, seven and twelve-week-obstructed groups presented, respectively, 0.81, 12.56 and 38.43-fold increase in total number of cells (N). Volume density presented a 0.97, 0.56 and 0.86-fold increase in 3, 7 and 12-week-obstructed groups, respectively. And finally, mean muscle cell volume (Vn) presented a 0.62, 0.81 and 0.82-fold in 3, 7 and 12-week obstructed groups, respectively. Both mechanisms: hypertrophy and hyperplasia happened to occur on rabbit´s urinary bladder, thought we do not know the exact sequence in which they appear altogether.

Orientador: Cláudia Helena Pellizon / Banca: Silvana Artioli Schellini / Banca: Cláudia Valeria Seullner Brandão / Resumo: 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 / Abstract: 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 / Mestre

Orientador: João Guilherme Padilha Filho / Banca: Claudia Acosta Duarte / Banca: Fabrício Bernardo de Jesus Brasil / Banca: Júlio Carlos Canola / Banca: Márcia Rita Fernandes Machado / Resumo: Foi utilizado na presente pesquisa o ultra-som pulsado de baixa intensidade, com a finalidade de avaliar, experimentalmente, seus efeitos sobre a reparação de falhas ósseas produzidas em rádio de coelhos, preenchidas ou não com o cimento de fosfato de cálcio adicionado com fibras de náilon. Foram utilizados 12 coelhos, raça Nova Zelândia, separados em dois grupos experimentais iguais (n=6) e escolhidos aleatoriamente (Grupo Tratado- GT e Grupo Controle-GC). As falhas ósseas de aproximadamente oito milímetros de extensão foram produzidas na diáfise de ambos os rádios, sendo as do membro direito preenchidas com o cimento de fosfato de cálcio sob a forma granulada e as do esquerdo, não preenchidas. Os animais do grupo tratado receberam estímulo pelo ultra-som pulsado de baixa intensidade durante 15 minutos nos primeiros cinco dias e dez minutos nos cinco dias seguintes, em ambos os membros. Os animais do grupo controle não foram estimulados pelo ultra-som. O controle radiográfico foi realizado no pós-operatório imediato e aos sete, 15 e 30 dias, de acordo com o tempo de observação de cada subgrupo (15 e 30 dias). Após o sacrifício, as áreas que continham as falhas ósseas foram processadas para a avaliação histopatológica. Os resultados das análises radiográfica e histolopatológica revelaram uma evolução mais rápida e intensa da proliferação de tecido ósseo nas falhas, preenchidas ou não pelo cimento, porém que receberam estímulo pelo ultra-som. Os resultados obtidos neste trabalho mostraram que o ultra-som pulsado de baixa intensidade é ser um recurso extremamente eficaz na aceleração do processo de ossificação e que, associado ao cimento de fosfato de cálcio com fibras de náilon, tem este processo intensificado, demonstrando, assim, o poder osteoindutor deste biomaterial. / Abstract: The present experimental research evaluated the effects of low intensity pulsed ultrasound for repair bone defects produced in rabbit's radius, filled in or not with calcium phosphate cement incorporated with nylon fibers. Twelve rabbits, from the New Zealand lineage, were randomly allocated in two equal experimental groups. An eight millimeters bone gap was surgically produced in the radius bone diaphysis and filled with the cement (right radius). The left limb bone gap remained empty. Animais were submitted to dessions of pulsed ultrasonic stimulus for 15 minutes during five days and ten minutes during more five days, in both radius. Radiological examinations were performed in the immediate postoperative and seven, 15 and 30 days after surgery (according with the postoperative follow-up -15 and 30 days). The bone defects were collected and submitted to optical microscopy. The results showed an increase and faster evolution of ossification's process in the bone defects, filled or not with the bone cement, but that received stimulus by ultrasound when compared to the control group. These results suggest that low-intensity pulsed ultrasound is an effective resource for acceleration of the ossification process and, when combined with calcium phosphate cement, this effect was increased. / Doutor

Objetivos: Avaliar as alterações retinianas em modelo experimental de hipóxia em coelhos aclimatizados em ambiente hipóxico-normobárico e investigar os efeitos do tratamento com bevacizumabe intravítreo (IV). Métodos: Vinte e dois coelhos New Zealand, com pesos entre 2,4 a 3,8 kg, foram divididos em quatro grupos. Os grupos S12% (n=5) e B12% (n=5) foram aclimatizados durante três dias consecutivos em concentrações de oxigênio (O2) a 12%. Os grupos S8% (n=5) e B8% (n=7) foram aclimatizados durante três dias consecutivos, com reduções graduais da concentração de O2, até atingir o nadir de 8%. Os olhos direitos (OD) foram mantidos como controle e os olhos esquerdos (OE) dos animais dos grupos S12% e S8% receberam injeção IV de 0,05 ml de solução salina balanceada (SSB), enquanto os OE dos grupos B12% e B8% receberam 0,05 ml (1,25 mg) de bevacizumabe IV. Foram realizados exames de tomografia de coerência óptica (OCT) para avaliação da espessura dos segmentos retinianos (SR) e coroidianos (SC), angiografia por fluoresceína sódica (AF) para observação da presença ou ausência de vasodilatação e tortuosidade da vasculatura retiniana e quantificação do Vascular Endothelial Growth Factor (VEGF) do humor aquoso e soro no primeiro dia (D0), antes do tratamento, no terceiro dia de hipóxia (D7) e no décimo primeiro dia (D11), utilizando-se a técnica do Luminex®. Após, os animais foram sacrificados e amostras do tecido retiniano foram avaliadas por histologia e imuno-histoquímica (IHQ). Resultados: Comparando-se os cortes horizontais dos OD (controle) nos períodos D0 e D7, notou-se redução de 8% (p<0,0001) e 10% (p<0,0001) da espessura do SR nas concentrações de O2 a 12% e 8%, respectivamente. Comparando-se os cortes verticais nos mesmos períodos, verificou-se redução da espessura do SR de 7%, tanto nas concentrações a 12% (p<0,0001) como a 8% (p<0,0001). Nos olhos tratados com bevacizumabe, a redução das médias das espessuras do SR para os cortes horizontais entre os períodos D0 e D7 foi de 6% (<0,0001) e 9% (<0,0001), para as concentrações de O2 a 12 e 8%, respectivamente. Enquanto que nos olhos tratados com SSB no mesmo período, observou-se redução de 8% (<0,0001) e 6% (<0,0001) para as concentrações de O2 a 12 e 8%, respectivamente, nos cortes horizontais. Nos cortes verticais, para os olhos tratados com bevacizumabe, houve redução de 5% (p=0,0005) e 8% (<0,0001) para concentrações de O2 a 12% e 8%, respectivamente; e para os olhos tratados com SSB foi encontrada redução de 7% (<0,0001) e 8% (<0,0001) nas concentrações de O2 a 12% e 8%, respectivamente. As espessuras dos SC não apresentaram alterações. O grupo B8 apresentou diferença estatisticamente significativa na análise da proporção dos olhos que não evidenciaram vasodilatação e tortuosidade dos vasos retinianos durante o período hipoxêmico, e não foram observados neovasos retinianos. A histologia e IHQ dos olhos tratados com SSB e bevacizumabe não demonstraram alterações quando comparados com os controles. Conclusões: A aclimatização de coelhos em ambiente hipóxico-normobárico resultou na redução da espessura do SR no terceiro dia de hipóxia. Notou-se, ainda, aumento da tortuosidade e vasodilatação. O bevacizumabe IV não inibiu a redução da espessura retiniana, mas sim a vasodilatação e tortuosidade vascular. / Objectives: Evaluate retinal changes in experimental model of hypoxia in rabbits acclimatized in normobaric-hypoxic environment and to investigate the effects of the treatment by intravitreal (IV) bevacizumab drug. Methods: Twenty two New Zealand rabbits weighing between 2,4 to 3,8 kg were divided into 4 groups. The groups S12 (n=5) and B12 (n=5) were acclimatized for 3 consecutive days in oxygen concentration (O2) to 12%. The groups S8 (n=5) and B8 (n=7) were acclimatized for 3 consecutive days with gradual reductions in O2 concentration until the nadir of 8%. The right eye (RE) were kept as controls and the left eye (LE) of the animals belonging to S12 and S8 groups received IV injection of 0,05 ml of balanced salt solution (BSS), while the LE belonging to groups B12 and B8 received 0,05 ml (1,25 mg) of bevacizumab IV. Optical coherence tomography (OCT) to evaluate the thickness of the retinal segments (RS) and choroidalsegments (CS), sodium fluorescein angiography (FA) for evaluation of the presence or absence of vasodilation and tortuosity of the retinal vasculature and quantification of VEGF in the aqueous fluid and peripheral blood sample were conducted at the first day (D0) before treatment, on the third day of hypoxia (D7) and day 11 (D11) using the Luminex® technique. After the animals were sacrificed, the retinal tissue samples were evaluated by histology and immunohistochemistry (IHC). Results: Comparing the horizontal sections of the RE (control) in D0 and D7 periods, a reduction of 8% (p<0,0001) and 10% (p<0,0001) the thickness of the RS in O2 concentration at 12% and 8%, respectively. Comparing the vertical cuts in the same period, there was reduced RS thickness of 7% in both concentrations to 12% (p<0,0001) and 8% (p<0,0001). In the eyes treated with bevacizumab, to reduce the average thickness of the retinal segment for horizontal cuts between D0 and D7 periods were 6% (<0,0001) and 9% (<0,0001) for O2 concentrations to 12 and 8%, respectively. While in the eyes treated with BSS in the same period, there was an 8% reduction (<0,0001) and 6% (<0,0001) for the O2 concentration at the 12% and 8%, respectively, in the horizontal cuts. In the vertical sections is observed for the eyes treated with bevacizumab, 5% reduction (p=0.0005) and 8% (<0,0001) O2 concentration at 12% and 8%, respectively; and BSS treated eyes was reduced by 7% (<0,0001) and 8% (<0,0001) in the O2 concentrations of 12% and 8%, respectively. The thickness of the CS did not show changes. The B8 group showed statistical difference in the analysis of the eyes that did not have vasodilation and tortuosity of the retinal vessels during the hypoxic period. Retinal neovascularization were not observed. Histology and IHC of the eyes treated with BSS and bevacizumab showed no changes compared to the control eyes. Conclusions: The acclimatization of the rabbits in normobaric-hypoxic environment has the effect of reducing the thickness RS on the third day of hypoxia. It is observed also increased tortuosity and vasodilation. The intravitreal bevacizumab does not inhibit retinal thickness decrease, but inhibits vasodilation and vascular tortuosity.

A embolização intra-arterial é rotineiramente utilizada na prática clinica como co-adjuvante pré-operatório ou controle de tumores, tratamento de malformações arteriovenosas e outras doenças vasculares. Em vários casos é realizada com uso de partículas de diferentes formas e composições. Um agente embolizante esférico e utilizado com bons resultados é o trisacryl (Embosphere®; BioSphere® Medical). Um novo agente embólico - polivinil acetato esférico cobertas com polivinil álcool (PVAc) foi desenvolvido recentemente no Brasil. Este trabalho tem objetivo de avaliar, após embolização renal, o grau de oclusão vascular, recanalização da luz vascular e a necrose da parede vascular provocados por partículas de PVAc, utilizando como parâmetro partículas de trisacryl. Setenta e nove fêmeas de coelhos do tipo albino New Zealand foram submetidas a cateterização arterial do rim direito; trinta e três animais foram embolizados com trisacryl, trinta e um com PVAc e quinze animais compuseram o grupo de simulação, tendo sido excluídos quatro animais (três trisacryl e um PVAc) devido a óbito precoce. Foram criados cinco subgrupos de seis animais, que foram sacrificados após 48 horas, 5 dias, 10 dias, 30 dias e 90 dias após a embolização. O grupo de simulação seguiu a mesma ordem temporal com três animais em cada grupo. As técnicas de coloração utilizadas foram os métodos de hematoxilina-eosina (HE) e tricrômico de Masson com observação por microscopia óptica. Os resultados mostraram diferença significativa entre o grau de oclusão vascular nos grupos de 5 dias e 10 dias e necrose no grupo de 48 horas em favor do grupo embolizado com PVAc, que apresentou reação tecidual adequada (redução volumétrica e isquemia) e menor grau de recanalização que o trisacryl / Intra-arterial embolization is often utilized in medical practice preoperatively as adjuvant in controlling tumors, treatment of arteriovenous malformations and other vascular diseases. Often times, particles of different forms and compositions are employed. trisacryl (Embosphere®; BioSphere® Medical), a spheric embolic agent, is nowadays used with very satisfactory results. However, a new embolic agent spheric polyvinyl alcohol-covered polivinyl acetate (PVAc)- has been developed in Brazil. This study evaluates the degree of vascular occlusion, vascular recanalization and the necrosis of vascular wall caused by PVAc particles, compared with trisacryl, after renal embolization. Seventy-nine female albine New Zealand rabbits underwent arterial catheterization of the right kidney; Thirty-three animals were embolized with trisacryl, thirty-one with PVAc and fifteen were kept as control group, four animals were excluded (three trisacryl and one PVAc) due to early death. Five subgroups of six animals were created. The animals in the different groups were sacrificed 48 hours, 5 days, 10 days, 30 days and 90 days after embolization. The control group was divided into subgroups of three animals, for the same period of time. Their kidneys were dyed with hematoxylin-eosin (HE) and Masson tricromic and examined using optic microscopy. The results showed a significant difference between the five-day and ten-day groups with regard to the degree of vascular occlusion, and the amount of necrosis in the forty-eight-hour group. Both findings favor the PVAc group, with adequate tissue reaction (ischemia and volumetric reduction) and less recanalization than with trisacryl

The European rabbit lives in defined social groups of between two and about twenty individuals. There are distinct social hierarchies within each group. Rabbits are known to scent-mark their environment with secretions from several glands, and the secretion of the submandibular cutaneous gland is strongly correlated with social status. Dominant, male rabbits have a higher secretory activity of the gland, and show much more scent-marking behaviour than do any other individuals within the social group. This study was principally conducted at Hope Farm, Cattai National Park in New South Wales, Australia.The proteinaceous components of the secretion varied between individuals, but the protein profile of an individual did not change over time.It was found that dominant rabbits chin mark preferentially at the entrances to warrens, and at the boundaries of their territory.The work in this study provides new insights into the way that rabbit semiochemical messages work. The difference between the secretion of a subordinate and a dominant rabbit appears to be due to the presence or absence of one compound, 2-phenoxy ethanol. This compound, with known fixative properties, supports the idea that the only difference between dominant and subordinate secretions is whether or not they persist in the environment after marking. Such a mechanism for asserting dominance may be much more common in mammals than is apparent from the published literature / Doctor of Philosophy (PhD)

Background: Achilles tendinopathy is a common clinical syndrome of chronic Achilles tendon pain combined with thickening of the tendon and impaired tendon function. Tendinopathy is often, but not always, induced by mechanical overload, and is frequently accompanied by abnormalities at the tissue level, such as hypercellularity and angiogenesis, in which case the condition is called tendinosis. In tendinosis, there are no signs of intratendinous inflammation, but occasionally increased apoptosis is observed. Tendinosis is often hard to treat and its pathogenesis is still not clear. Recently, a new hypothesis has gained support, suggesting a biochemical model based on the presence of a non-neuronal production of classically neuronal signal substances by the primary tendon cells (tenocytes) in tendinosis. The possible functional importance of these signal substances in tendons is unknown and needs to be studied. In particular, the neuropeptide substance P (SP) and catecholamines are of interest in this regard, since these substances have been found to be up-regulated in tendinosis. As both SP and catecholamines are known to exert effects in other tissues resulting in changes similar to those characteristic of tendinosis, it is possible that they have a role in tendinosis development. It is furthermore unknown what elicits the increased intratendinous neuropeptide production in tendinosis, but given that tendon overload is a prominent riskfactor, it is possible that mechanical stimuli are involved. The hypothesis of this thesis work was that intratendinous production of SP is up-regulated in response to load of Achilles tendons/tenocytes, and thatstimulation of the preferred SP receptor, the neurokinin-1 receptor (NK-1 R), aswell as stimulation of the catecholamine α2 adrenoreceptors, contribute to the hypercellularity seen in tendinosis, via increased proliferation and/or decreased apoptosis, and that SP stimulates tendon angiogenesis. The purpose of the studies was to test this hypothesis. To achieve this, two model systems were used: One in vivo (rabbit Achilles tendon overload model of tendinosis) and one in vitro (human primary Achilles tendon cell culture model). Results: In the rabbit Achilles tendon tissue, SP and NK-1 R expression was extensive in the blood vessel walls, but also to some extent seen in the tenocytes. Quantification of endogenously produced SP in vivo confirmed intratendinous production of the peptide. The production of SP by human tendon cells in vitro was furthermore demonstrated. The catecholamine synthesizing enzyme tyrosine hydroxylase (TH), as well as the α2A adrenoreceptor (α2A AR), were detected in the tenocytes, both in vivo in the rabbit tissue and in vitro in the human tendon cells. As a response to mechanical loading in the in vivo model, the intratendinous levels of SP increased, and this elevation was found to precede distinct tendinosis changes. The in vitro model demonstrated the same response to load, i.e. an increased SP expression, but in this case also a decrease in the NK-1 R expression. In the in vivo model, exogenously administered SP, as well as clonidine (an α2 AR agonist), accelerated tenocyte hypercellularity, an effect that was not seen when administrating a specific α2A AR antagonist. Exogenous administration of SP also resulted in intratendinous angiogenesis and paratendinous inflammation. In the in vitro model, both SP and clonidine had proliferative effects on the human tenocytes, specifically mediated via NK-1R and α2A AR, respectively; both of which in turn involved activation/phosphorylation of the extracellular signal-regulated kinases 1 and 2 (ERK1/2). Exogenously administered SP, in Anti-Fas induced apoptosis of the tenocytes in vitro, confirmed SP to have an anti-apoptotic effect on these cells. This effect was specifically mediated via NK-1 R and the known anti-apoptotic Akt pathway. Conclusions: In summary, this thesis concludes that stimulation of NK-1 R and α2A AR on tenocytes, both in vitro and in vivo, mediates significant cell signalling effects leading to processes known to occur in tendinosis, including hypercellularity. The pathological role of the hypercellularity in tendinosis is still unclear, but it is likely to affect collagen metabolism/turnover and arrangement, and thereby indirectly tendon biomechanical function. Additional evidence is here provided showing that SP not only causes tenocyte proliferation, but also contributes to anti-apoptotic events. Furthermore, it was concluded that SP may be involved in the development of tendinosis, since its production is increased in response to load, preceding tendinosis, and since SP accelerates tendinosis changes, through some mechanistic pathways here delineated. These findings suggest that inhibition of SP, and possibly also catecholamines, could be beneficial in the reconstitution/normalization of tendon structure in tendinosis.

Lawsonia intracellularis causes proliferative enteropathies in juvenile mammals. The porcine (PPE) and equine (EPE) diseases are worldwide. Rabbits and hamsters are naturally susceptible, the latter being a classic modeling-host for PPE. None is known for EPE, besides foals. An in vitro evaluation of antimicrobial efficacy against L. intracellularis is difficult. This study aimed to validate a laboratory animal EPE model and to investigate pharmacokinetics (PK) and efficacy of gallium maltolate (GaM) as an alternative antimicrobial therapy. Infected animals were inoculated with cell-cultured L. intracellularis and infection was verified with clinically utilized diagnostic tests. Initially, 2 groups of EPE-infected rabbits were compared to 1 uninfected group. After inoculation (PI), EPE-infected rabbits showed mild clinical signs; detectable seroconversion, fecal shedding, gross lesions in intestinal tissues (IT), and early immuno-histochemistry labeling of L. intracellularis antigen. Thus, a humane EPE-rabbit model was achieved. Subsequently, EPE-infected hamsters were compared to uninfected and PPE-infected hamsters; whereas, PPE-infected rabbits were compared to EPE-infected rabbits. EPE-hamsters did not develop infection, unlike PPE-infected controls; and PPE-rabbits did not develop IT lesions or seroconversion comparable to EPE-rabbits. Therefore rabbits were chosen as the EPE modeling-host for the GaM studies. First, GaM PK and IT concentrations of Ga and Fe were measured. Then, GaM efficacy was compared to a current EPE antimicrobial treatment. During sampling, the intra-arterial catheters in the rabbits’ ears were protected with a novel moleskin-cover, allowing repeated sampling while minimally restrained. The PK study was based on the comparison of EPE-infected and uninfected rabbits, after a single treatment with GaM, collection of serial blood samples and IT samples. The only differing PK parameter, between groups, was a decrease in the terminal phase rate constant of the EPE-rabbits, so a 48h dosing interval was chosen for the efficacy study. In the efficacy study, 3 groups of EPE-infected rabbits were treated with GaM, doxycycline and a placebo, respectively. No differences were noted between treatments, in terms of lesions and fecal shedding. GaM appears no more efficacious than doxycycline in EPE- rabbits. In conclusion, albeit GaM tolerance appeared adequate in rabbits, results do not support its use in EPE-infected animals.

Francisella tularensis is a zoonotic bacterium that must exist in diverse environments ranging from arthropod vectors to mammalian hosts. To better understand how genes are regulated in these different environments, a transcriptional response- regulator gene (genome locus FTL0552) was deleted in F. tularensis live vaccine strain (LVS). The FTL0552 deletion mutant exhibited slightly reduced rates of extracellular growth but was unable to replicate or survive in mouse macrophages and was avirulent in the mouse model using either BALB/c or C57BL/6 mice. Mice infected with the FTL0552 mutant produced reduced levels of inflammatory cytokines, exhibited reduced histopathology and cleared the bacteria quicker than mice infected with LVS. Mice that survived infection with the FTL0552 mutant were afforded partial protection when challenged with a lethal dose of the virulent Schu S4 strain (4 of 10 survivors, day 21 post infection) when compared to naïve mice (0 of 10 survivors by day 7 post infection). Microarray experiments indicate that 148 genes are regulated in the FTL0552 mutant. Most of the genes are down regulated, indicating that FTL0552 controls transcription of genes in a positive manner. The list of down regulated genes includes genes located within the Francisella Pathogenicity Island (FPI) that are essential for intracellular survival and virulence of Francisella tularensis. Furthermore, a mutant in FTL0552 or the comparable locus in Schu S4 (FTT1557c) may be an alternative candidate vaccine for tularemia.

This thesis describes a relationship between maternal preference and offspring performance in a population of the butterfly Euphydryas editha that used two host plants, Pedicularis semibarbata and Collinsia torreyi from 1979 to 2001, but now no longer uses Collinsia. In the light of the known history of diet change in this butterfly population, it is not surprising that maternal oviposition preference was variable. Although the diet of the butterflies that evolved rapidly in the 1980’s is no longer changing, I still discovered some females with a chemical preference for Collinsia. This seems to be a legacy of recent anthropogenic diet evolution. The evolution of host preference of females in Rabbit Meadow has not finished yet. Variation of offspring weight and survival were measured and showed a complex relationship with adult preference. Although quite a few adults strongly rejected Collinsia, their offspring grew well on this host, and there was no significant trend for the offspring of strongly Pedicularis-preferring butterflies to perform more poorly on Collinsia. / text