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Made available in DSpace on 2014-07-29T15:13:56Z (GMT). No. of bitstreams: 1 TESE SAULO FERNANDES MANO DE CARVALHO.pdf: 5897981 bytes, checksum: 9ded1ddc23ddf1eb697350aee8c49480 (MD5) Previous issue date: 2009-12-22 / Adrenalectomy is a highly complex surgical procedure. In order to perform it, surgeons must have a profound knowledge of the anatomophysiologic aspects of the adrenal glands, especially their vascular diversity, as well as full understanding of diagnostic means so as to properly identify their diseases. Open adrenalectomy is the most widely used method in veterinary medicine, while laparoscopic adrenalectomy usually is the method of choice in human medicine. Hyperadrenocorticism, whether hypophysis-dependent or not, is the most the most common adrenal disease. Treatment involves stopping the growth of tumors either surgically or chemically. Treatment of choice will depend on tumor functionality, type and size, as well as on its image. The swine model has proven adequate for surgical procedures, since it possesses standardized experimentation protocols and physiological parameters. Among the main benefits of laparoscopic adrenalectomy versus open adrenalectomy is rapid recovery and diminished hospitalization time. Laparoscopic adrenalectomy is the procedure of choice in human medicine, and it is nowadays considered to be the gold standard. In veterinary medicine more research is needed so as to better establish its advantages over open adrenalectomy. In this study open adrenalectomy was compared to laparoscopic adrenalectomy. 32 swines, divided into four groups of eight animals each, underwent surgery; being it that one group underwent open and the other laparoscopic adrenalectomy, with their respective control groups (sham). Parameters such as surgical time, body temperature, haematocrit, surgical intercurrences and XXXXX, as well as physiological, hormonal and metabolic responses were evaluated in young swines, both in open and laparoscopic adrenalectomy. There were no significant differences in surgical times. Most frequent intercurrences were accidents with intestinal loops, lesions to adrenal vessels and renal haematoma. Blood losses were not significant and, even though there was hypothermia it did not lead to any unfavorable clinical outcome. Deambulation time was longer for the open adrenalectomy group, although the difference was not significant. Significant differences were found in leucometry values of the laparoscopic sham group, which were higher when compared to laparoscopic groups; SpO2 of the G3 group was lower than that of the other groups, and PCR of the laparoscopic groups were lower postoperatively. There were no significant differences in mean blood pressure in all of four groups. Laparoscopy is a reliable technique for experimental adrenalectomy in swines and can be used as a reference for surgical treatment of adrenal diseases in other animal species. Metabolic parameters did not show significant differences. These results indicated that the laparoscopic technique is beneficial over open surgery, and that it can be considered a safe procedure for other species. Adrenalectomy is a highly complex surgical procedure. In order to perform it, surgeons must have a profound knowledge of the anatomophysiologic aspects of the adrenal glands, especially their vascular diversity, as well as full understanding of diagnostic means so as to properly identify their diseases. Open adrenalectomy is the most widely used method in veterinary medicine, while laparoscopic adrenalectomy usually is the method of choice in human medicine. Hyperadrenocorticism, whether hypophysis-dependent or not, is the most the most common adrenal disease. Treatment involves stopping the growth of tumors either surgically or chemically. Treatment of choice will depend on tumor functionality, type and size, as well as on its image. The swine model has proven adequate for surgical procedures, since it possesses standardized experimentation protocols and physiological parameters. Among the main benefits of laparoscopic adrenalectomy versus open adrenalectomy is rapid recovery and diminished hospitalization time. Laparoscopic adrenalectomy is the procedure of choice in human medicine, and it is nowadays considered to be the gold standard. In veterinary medicine more research is needed so as to better establish its advantages over open adrenalectomy. In this study open adrenalectomy was compared to laparoscopic adrenalectomy. 32 swines, divided into four groups of eight animals each, underwent surgery; being it that one group underwent open and the other laparoscopic adrenalectomy, with their respective control groups (sham). Parameters such as surgical time, body temperature, haematocrit, surgical intercurrences and XXXXX, as well as physiological, hormonal and metabolic responses were evaluated in young swines, both in open and laparoscopic adrenalectomy. There were no significant differences in surgical times. Most frequent intercurrences were accidents with intestinal loops, lesions to adrenal vessels and renal haematoma. Blood losses were not significant and, even though there was hypothermia it did not lead to any unfavorable clinical outcome. Deambulation time was longer for the open adrenalectomy group, although the difference was not significant. Significant differences were found in leucometry values of the laparoscopic sham group, which were higher when compared to laparoscopic groups; SpO2 of the G3 group was lower than that of the other groups, and PCR of the laparoscopic groups were lower postoperatively. There were no significant differences in mean blood pressure in all of four groups. Laparoscopy is a reliable technique for experimental adrenalectomy in swines and can be used as a reference for surgical treatment of adrenal diseases in other animal species. Metabolic parameters did not show significant differences. These results indicated that the laparoscopic technique is beneficial over open surgery, and that it can be considered a safe procedure for other species. / Adrenalectomia é um procedimento operatório de alto grau de complexidade. Para sua execução o cirurgião deve ter conhecimento dos aspectos anatomofisiológicos das glândulas adrenais, especialmente sua diversidade vascular, deve ainda ter pleno entendimento sobre os recursos diagnósticos necessários para identificação das suas enfermidades. Adrenalectomia aberta é o método mais utilizado em medicina veterinária, enquanto na medicina humana a abordagem laparoscópica é a de eleição. O hiperadrenocorticismo, que pode ser hipófise dependente ou não, é enfermidade adrenal de maior frequência. Seu tratamento consiste na contenção da evolução dos tumores por meio de fármacos ou cirúrgico. A escolha do tratamento depende da funcionalidade, tipo e tamanho do tumor e da caracterização dos estudos de imagem. O modelo suíno mostrou-se adequado para a execução dos procedimentos operatórios, visto possuir protocolo de experimentação e parâmetros fisiológicos padronizados. Dentre os principais benefícios da adrenalectomia laparoscópica (AL) frente à adrenalectomia aberta (AA) destaca-se a rápida recuperação dos pacientes com diminuição do tempo de internação. A adrenalectomia laparoscópica é o procedimento de escolha em medicina humana, sendo caracterizada atualmente como padrão ouro. Em medicina veterinária, ainda há necessidade de melhor caracterização dos seus resultados afim de que seus benefícios em relação à adrenalectomia aberta possam ser conhecidos. Neste estudo foi comparada a AA com a AL. Foram operados 32 suínos, divididos em quatro grupos de oito animais, sendo um grupo submetido à AA e outro grupo à AL, com seus respectivos grupos controle (sham). Foram avaliados parâmetros referentes a tempo operatório, temperatura corporal, hematócrito, intercorrências operatórias e tempo de deambulação. Bem com as respostas fisiológicas, hormonais e metabólicas oriundas da adrenalectomia laparoscópica e aberta em suínos jovens. Não houve diferença significativa entre os tempos operatórios. As intercorrências mais frequentes foram acidentes em alças intestinais, lesões em vasos adrenais e hematoma renal. As perdas sanguíneas não foram significativas e apesar de ter ocorrido hipotermia esta não teve repercussão clínica. O tempo de deambulação foi maior para o grupo AA, mas sem diferença significativa em relação ao AL. As diferenças significativas encontradas se relacionaram aos valores de leucometria, os quais apresentaram elevação no grupo sham laparotômico em relação aos grupos laparoscópicos; a SpO2 do grupo G3 foi inferior aos demais grupos; os valores de PCR dos grupos laparoscópicos foram menores no pós operatório. Não houve diferença significativa na pressão arterial média dos quatro grupos. A laparoscopia para adrenalectomia experimental em suínos é uma técnica confiável podendo servir como referência para o tratamento cirúrgico nas outras espécies animais. Os parâmetros metabólicos analisados não apresentaram diferenças significativas. Estes resultados indicaram benefícios da abordagem laparoscópica em relação à aberta, podendo ser considerado um procedimento seguro para utilização em outras espécies.

Signalverarbeitung im Nervensystem hängt sowohl von der Netzwerkstruktur, als auch den zellulären Eigenschaften der Nervenzellen ab. In dieser Abhandlung werden zwei zelluläre Eigenschaften im Hinblick auf ihre funktionellen Anpassungsmöglichkeiten untersucht: Es wird gezeigt, dass neuronale Morphologie die Signalweiterleitung unter Berücksichtigung energetischer Beschränkungen verstärken kann, und dass selbst kleine Änderungen in biophysikalischen Parametern die Aktivierungsbifurkation in Nervenzellen, und damit deren Informationskodierung, wechseln können. Im ersten Teil dieser Abhandlung wird, unter Verwendung von mathematischen Modellen und Daten, die Hypothese aufgestellt, dass Energie-effiziente Signalweiterleitung als starker Evolutionsdruck für unterschiedliche Zellkörperlagen bei Nervenzellen wirkt. Um Energie zu sparen, kann die Signalweiterleitung vom Dendrit zum Axon verstärkt werden, indem relativ kleine Zellkörper zwischen Dendrit und Axon eingebaut werden, während relativ große Zellkörper besser ausgelagert werden. Im zweiten Teil wird gezeigt, dass biophysikalische Parameter, wie Temperatur, Membranwiderstand oder Kapazität, den Feuermechanismus des Neurons ändern, und damit gleichfalls Aktionspotential-basierte Informationsverarbeitung. Diese Arbeit identifiziert die sogenannte "saddle-node-loop" (Sattel-Knoten-Schlaufe) Bifurkation als den Übergang, der besonders drastische funktionale Auswirkungen hat. Neben der Änderung neuronaler Filtereigenschaften sowie der Ankopplung an Stimuli, führt die "saddle-node-loop" Bifurkation zu einer Erhöhung der Netzwerk-Synchronisation, was möglicherweise für das Auslösen von Anfällen durch Temperatur, wie bei Fieberkrämpfen, interessant sein könnte. / Signal processing in nervous systems is shaped by the connectome as well as the cellular properties of nerve cells. In this thesis, two cellular properties are investigated with respect to the functional adaptations they provide: It is shown that neuronal morphology can improve signal transmission under energetic constraints, and that even small changes in biophysical parameters can switch spike generation, and thus information encoding. In the first project of the thesis, mathematical modeling and data are deployed to suggest energy-efficient signaling as a major evolutionary pressure behind morphological adaptations of cell body location: In order to save energy, the electrical signal transmission from dendrite to axon can be enhanced if a relatively small cell body is located between dendrite and axon, while a relatively large cell body should be externalized. In the second project, it is shown that biophysical parameters, such as temperature, membrane leak or capacitance, can transform neuronal excitability (i.e., the spike onset bifurcation) and, with that, spike-based information processing. This thesis identifies the so-called saddle-node-loop bifurcation as the transition with particularly drastic functional implications. Besides altering neuronal filters and stimulus locking, the saddle-node-loop bifurcation leads to an increase in network synchronization, which may potentially be relevant for the initiation of seizures in response to increased temperature, such as during fever cramps.