Universiẗat, Diss., 2002--Giessen.

Orientador: Luis Gustavo Gosuen Gonçalves Dias / Resumo: Identificar alterações nos músculos paravertebrais cervicais e do ligamento nucal que possam estar relacionadas à espondilomielopatia cervical (EMC) em cães das raças Doberman Pinscher (DP) e Dogue Alemão (DA). Determinar as áreas de secção transversa (AST) de músculos paravertebrais cervicais e identificar possível assimetria entre os antímeros. Classificar o grau de alteração morfológica destas musculaturas e correlacionar os achados com o quadro neurológico dos pacientes. Material e métodos – Estudo retrospectivo em que foram analisadas imagens transversais de ressonância magnética de 60 cães das raças Doberman Pinscher (DP) e Dogue Alemão (DA), sendo 29 clinicamente normais (CN) e 31 acometidos pela EMC. Foram mensuradas as AST dos músculos, a espessura do ligamento nucal e determinado o índice de assimetria dos músculos entre os antímeros. O grau de alteração morfológica, por meio da presença de hipersinal nos músculos extensores paravertebrais foi determinado e correlacionado aos sinais clínicos neurológicos. Resultados – Cães DP-EMC apresentaram menor AST dos mm. longo do pescoço ao nível de C5 (p < 0,034) e dos mm. cleidomastoideo ao nível de C3 (p < 0,017), C4 (p < 0,012) e C5 (p < 0,014), quando comparados aos DP-CN. Para os cães DA foram encontradas diferenças significativas entre as AST dos mm. cleidomastóideo ao nível de C5 (p < 0,022) e entre as espessuras do ligamento nucal, sendo que os cães DA-EMC apresentam menores AST e espessuras do ligamento. Para as duas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to identify changes in the cervical paravertebral muscles and nuchal ligament related to cervical spondylomyelopathy (CSM) disease in the Doberman Pinscher (DP) and Grate Dane (GD) breed dogs. Measure the cross-sectional area (CSA) of the selected paraspinal muscles and to assess their asymmetry. Also, to grade the morphological changes of the extensor muscles and correlate to the patient’s neurological status. Materials and methods – Retrospective resonance image study of 60 dogs: 29 clinically normal and 31 CSM-affected. The CSA of the muscles and the thickness of the nuchal ligament were measured, and the asymmetry index between the right and left sides of the selected extensor muscles was determined. The grades of morphological changes in the extensor muscles were obtained and associated to the patients’ neurological status. Results – Mean CSA of longus colli muscles at C5 (p < 0,034) and of cleidomastoideus muscles at the level of C3 (p < 0,017), C4 (p < 0,012) and C5 (p < 0,014) were significantly smaller in CSM-affected DP compared with those in the clinically normal DP. Significant differences were present between clinically normal and CSM-affected GD for the mean CSA of cleidomastoideus muscles at the C5 level (p < 0,022) and for the thickness of the nuchal ligament, with those measurements smaller in the CSM-affected dogs. All CSM-affected dogs were found to have high grades of morphological changes in the extensor muscles compared to the c... (Complete abstract click electronic access below) / Doutor

Submitted by Mario BC (mario@bc.ufrpe.br) on 2018-02-22T12:56:00Z No. of bitstreams: 1 Marilia de Albuquerque Bonelli.pdf: 1903907 bytes, checksum: 8de429c7dc9abc6c230fc38f56331819 (MD5) / Made available in DSpace on 2018-02-22T12:56:00Z (GMT). No. of bitstreams: 1 Marilia de Albuquerque Bonelli.pdf: 1903907 bytes, checksum: 8de429c7dc9abc6c230fc38f56331819 (MD5) Previous issue date: 2017-03-30 / Finite element models aid in understanding dynamic processes in the study of diseases and treatments. Cervical spondylomyelopathy (CSM), also called wobbler syndrome, is a disease that affects mainly large- and giant-breed dogs, and seems to have a static and dynamic component in its pathophysiology. The present objective was to create a finite element model representing the C2-C7 segment of the vertebral column of a Great Dane dog without abnormalities, as well as the adaptation of this model to represent a dorsal laminectomy and a hemilaminectomy at C5-C6. This is expected to contribute to the investigation of the biomechanical component of CSM, as well as allow a comparison of the various surgical methods proposed for treatment of this syndrome. A 2-year-old Great Dane dog without neurologic or imaging changes in the cervical region of the vertebral column was selected. Computed tomography images from this dog were processed to construct a finite element model representing vertebrae, intervertebral discs, and ligaments. Material properties were adapted from the literature. Range of motion of the model under 2Nm for flexion, extension, axial rotation, and lateral bending were compared with literature. Range of motion was observed to be lesser than cited for cadavers of a different breed. This difference could be considered as resulting from differences between breeds and the use of human material properties. When comparing the intact model with the modified laminectomy and hemilaminectomy models, an influence of the hemilaminectomy was observed in range of motion, especially in axial rotation to the side opposite the simulated procedure. Construction of these models would be the first step to applying finite element analysis to the study of CSM in Great Danes. / Modelos de elementos finitos ajudam a entender processos dinâmicos no estudo de doenças e tratamentos. Espondilomielopatia cervical (EMC), também chamada de síndrome de wobbler, é uma doença que afeta principalmente cães de raças grandes e gigantes, e que parece ter um componente estático e dinâmico na sua fisiopatogenia. Objetivou-se criar um modelo de elementos finitos representando o segmento de C2 a C7 da coluna vertebral de um dogue alemão sem alterações, assim como adaptar esse modelo para representar uma laminectomia dorsal e hemilaminectomia em C5-C6. Espera-se com isso contribuir para a investigação do componente biomecânico da EMC, além de permitir a comparação dos diversos métodos cirúrgicos propostos para o tratamento dessa síndrome. Foi selecionado um cão de 2 anos de idade, da raça Dogue alemão, sem alterações neurológicas ou de imagem na região cervical da coluna vertebral. Imagens de tomografia computadorizada deste cão foram processadas para construir um modelo de elementos finitos representando as vértebras, discos intervertebrais e ligamentos. As propriedades materiais foram adaptadas da literatura. A amplitude de movimento do modelo sob 2Nm para flexão, extensão, rotação axial e flexão lateral foram comparadas com a literatura. Observou-se que a amplitude de movimento do modelo foi menor do que a citada para cadáveres de outra raça. Considera-se que essa diferença possa advir de diferenças entre raças e do uso de propriedades materiais adaptadas de humanos. Ao comparar o modelo intacto com os modificados com laminectomia e hemilaminectomia, observou-se que houve influência da hemilaminectomia na amplitude de movimento, principalmente na rotação axial contralateral ao procedimento simulado. A construção desses modelos seria o primeiro passo para aplicar o uso do método de elementos finitos para o estudo da espondilomielopatia cervical em Dogues alemães.

Cervical stenotic myelopathy (CSM) is an important musculoskeletal and neurologic disease of the horse. Clinical disease occurs due to malformations of the vertebrae in the neck causing stenosis of the cervical vertebral canal and subsequent spinal cord compression. The disease is multifactorial in nature, therefore a clearer understanding of the etiology and pathogenesis of CSM will allow for improved management and therapeutic practices. This thesis examines issues of equine CSM diagnosis, skeletal tissue pathology, and inherited genetic determinants utilizing advances in biomedical imaging technologies and equine genomics. Magnetic resonance imaging (MRI) data provided a more complete assessment of the cervical column through image acquisition in multiple planes. First, MRI was compared to standing cervical radiographs for detection of stenosis. Using canal area or the cord canal area ratio, MRI more accurately predicted sites of compression in CSM cases. Secondly, articular process skeletal pathology localized on MRI was found to be more frequent and severe in CSM horses compared to controls. In addition, lesions were generalized throughout the cervical column and not limited to the spinal cord compression sites. A subset of lesions identified on MRI was evaluated using micro-CT and histopathology. Osteochondrosis, osseous cyst-like structures, fibrous tissue replacement of bone, and osteosclerosis were observed. These lesions support likely developmental aberrations of vertebral bone and cartilage maturation with secondary biomechanical influences. Bone cyst-like structures are a novel finding in this disease. Finally, the long-standing question of the contribution of genetic determinants to CSM was investigated using a genome wide association study (GWAS). Multiple significant loci were identified supporting the influence of a complex genetic trait in clinical disease. A simple Mendelian trait controlled by one gene is unlikely given the detection of variants across multiple chromosomes. Major contributions from this research include documentation of articular process bone and cartilage pathology in horses with CSM, support for abnormal cervical vertebrae development being an important contributing factor in the etiology and/or pathogenesis of equine CSM, and evidence that multiple genetic loci contribute to the CSM disease phenotype.

No description available.

Seit 1998 werden am Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB) in Kooperation mit der Charité-Universitätsmedizin Berlin Augentumore mit Protonen bestrahlt. Dazu beschleunigt ein Zyklotron, welches hauptsächlich für die Therapie genutzt wird, die Protonen auf eine Energie von 68MeV. Neben dem Therapieplatz existiert auch ein Experimentierplatz zu Forschungszwecken. Die Strahlaufbereitung erfolgt in beiden Anwendungsgebieten primär durch passives Aufstreuen des Strahls mit einer einzelnen Streufolie. Dies führt jedoch zu erheblichen Strahlverlusten, die die erreichbare Strahlintensität bzw. Dosisleistung im Feld limitieren. Ziel dieser Arbeit ist es, einen Bestrahlungsplatz mit aktiver, dreidimensionaler Strahlführung aufzubauen, um eine möglichst effiziente Strahlstromnutzung zu ermöglichen und flexibel auf Anforderungen an das Bestrahlungsfeld eingehen zu können. Zu diesem Zweck wurde ein Modell entwickelt, welches unter Berücksichtigung verschiedener Parameter der Messgeometrie, Strahlcharakteristik und Felderzeugung Strahlprofile berechnet. Dieses Modell wurde im Vergleich mit Monte-Carlo Simulationen und Messungen getestet und verifiziert. Anschließend konnten Untersuchungen zur Positionierung der verwendeten Komponenten durchgeführt sowie deren Einflüsse auf Penumbra, Homogenität und Transmission der Strahlfelder analysiert werden. Es zeigte sich, dass die hohen klinischen Anforderungen für die Anwendung in der Augentumortherapie am HZB erfüllt werden können, sofern stärkere Magnetspulen verwendet werden. Mit Hilfe des Modells wurden für einen optimierten Aufbau Strahlprofile berechnet und charakterisiert. Es konnte so gezeigt werden, dass unter diesen optimierten Bedingungen eine Anwendbarkeit des aktiven Systems in der Augentumortherapie möglich ist. Des Weiteren wurde im Verlauf dieser Arbeit ein statischer Modulator für den Bestrahlungsplatz am HZB entwickelt, mit Hilfe eines 3D-Druckers hergestellt und erfolgreich getestet. / Since 1998, ocular tumours have been irradiated with protons at the Helmholtz- Zentrum Berlin für Materialien und Energie GmbH (HZB) in cooperation with Charité-Universitätsmedizin Berlin. For this purpose a cyclotron is operated which accelerates protons to an energy of 68MeV and is mainly used for therapy purposes. In addition to the therapy station there is also an experimental station for research purposes. In both application areas, beam delivery is primarily achieved by passive scattering using a single scattering foil. However, this leads to considerable beam losses, which in turn limit the maximum beam intensity or dose rate in the irradiation field. The aim of this work is to construct an irradiation setup with active three-dimensional beam delivery in order to enable the most efficient possible use of beam current and to be able to respond flexibly to different irradiation field requirements. Therefore, a model was developed which calculates beam profiles taking into account various parameters of the measurement geometry, beam characteristics and field generation. This model was tested and verified in comparison with Monte Carlo simulations and measurements. Subsequently investigations into the positioning of the components used could be carried out and their influences on penumbra, homogeneity and transmission of the beam fields analysed. It was found that the high clinical requirements in terms of maximum penumbra and field homogeneity for the application in eye tumour therapy at HZB can be met if stronger magnetic coils were used. Model calculations were used to calculate and characterize different beam profiles for an optimized setup. It could be shown that under these optimized conditions an applicability of the active system in eye tumour therapy is possible. Furthermore, a static modulator for the irradiation site at HZB was developed in the course of this work, manufactured using a 3D printer and successfully tested.