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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
461

Estudo biomecânico comparativo, em cadáveres, da reconstrução do ligamento cruzado anterior do joelho com técnica convencional e com túneis duplos tibiais e femorais / An In Vitro biomechanical comparison study of anterior cruciate ligament reconstruction: single bundle versus anatomical double bundle techniques

Sasaki, Sandra Umeda 23 July 2007 (has links)
OBJETIVO: comparar a técnica de reconstrução convencional do LCA com enxerto patelar e feixe único com a técnica com enxerto patelar bipartido e quatro túneis ósseos, através de um estudo experimental biomecânico em joelhos de cadáveres com testes pareados, sem variação na quantidade de enxerto utilizada em ambas as técnicas. INTRODUÇÃO: As lesões do ligamento cruzado anterior (LCA) do joelho são comuns principalmente na prática esportiva, e o tratamento cirúrgico de reconstrução com o uso de enxertos autólogos, pelos bons resultados alcançados, um consenso na literatura mundial. As controvérsias ficam por conta das variações que podem apresentar a técnica deste procedimento, na busca constante pelo aperfeiçoamento da mesma. Uma delas encontra-se na troca da tradicional reconstrução de feixe único do LCA pela reconstrução dos dois feixes, visando uma maior semelhança com a anatomia do LCA original. Recentemente a tendência nesta técnica é pela passagem dos enxertos por dois túneis femorais e dois túneis tibiais. MÉTODOS: Nosso estudo foi realizado em joelhos de cadáveres (18 joelhos de 9 cadáveres), todos do sexo masculino, com idade variando entre 44 e 63 anos. Estas peças foram divididas aleatóriamente, sempre em pares, nos grupos A, de joelhos operados com a técnica de reconstrução do LCA com único feixe, e grupo B, de joelhos operados com a técnica de reconstrução com duplo feixe e quatro túneis ósseos. Cada espécime foi submetido a testes biomecânicos nas condições LCA íntegro, lesado e operado, com registro de dados de Deslocamento Anterior Máximo (DTAM), Rigidez Média (R) e Rotação Tibial Interna Passiva (RIT), sob força de 100N de deslocamento tibial horizontal, a 30°,60° e 90° de flexão dos joelhos. RESULTADOS: Não houve diferenças significativas, pelo método de Análise de Variância de grupos, entre as duas técnicas tanto para medidas de DTAM em 30°(p=0,47), 60°(p=0,59), 90°(p=0,27); como para R em 30° (p=0,93), 60° (p=0,97), 90° (p=0,45); e RIT em 30° (p= 0,59), 60° (p=0,67) e 90° (p=0,74). CONCLUSÕES: Em nosso estudo, a técnica de reconstrução dos dois feixes do LCA com enxerto patelar e quatro túneis tem comportamento biomecânico semelhante ao da reconstrução do LCA com enxerto patelar de feixe único, sob os aspectos de deslocamento anterior tibial, rigidez e rotação tibial passiva, durante o movimento de deslocamento anterior tibial com força constante / PURPOSES: Test an anatomical double bundle reconstruction technique with a longitudinally split bone-patellar tendon-bone graft through double femoral and tibial tunnels and biomechanically compare it to conventional single bundle reconstruction with the same total amount of bone-patelar tendon-bone graft in a paired experimental cadaver study. INTRODUCTION: Anterior Cruciate Ligament ruptures are frequent especially in sports practice. Surgical reconstruction with autologous grafts widely employed in international literature. Controversies remain in respect to technique variations as continuous research for improvement takes place. One these are the anatomical double bundle techniques instead of conventional single bundle (antero-medial bundle) technique. More recently there is a tendency of positioning of the two bundles through double tunnel technique in the femur and the tibia. METHODS: Nine pairs of male cadaver knees, age ranging from 44 to 63 years were randomized into 2 groups, (A) single bundle reconstruction and (B) anatomical double bundle reconstruction through double femoral and double tibial tunnels. Each knee was biomechanically tested in 3 conditions: intact ACL, sectioned ACL and reconstructed ACL. Maximum anterior dislocation, rigidity and passive internal tibia rotation were recorded with the knee submitted to a 100N horizontal anterior dislocation force applied to the tibia with the knee in 30º, 60º and 90º of flexion. RESULTS: There were no differences between the two techniques for any of the measurements. CONCLUSIONS: The technique of anatomical double bundle reconstruction of the anterior cruciate ligament with bone-patellar tendon-bone graft has a similar biomechanical behavior in regard to anterior tibial dislocation, rigidity and passive internal tibial rotation.
462

The role of mechanical loading, bone morphogenetic proteins and erroneous differentiation of tendon-derived stem cells in the pathogenesis of patellar tendinopathy: a potential mechanism for the chondron-ossification and failed healing in patellar tendinopathy. / CUHK electronic theses & dissertations collection

January 2011 (has links)
Chronic patellar tendinopathy is a degenerative tendon disorder characterized by chronic activity-related, anterior knee pain associated with localized tenderness, swelling and impaired performance, which is a common clinical problem in athletes. The pathogenesis of patellar tendinopathy is still largely unknown, although tendon overuse is the most commonly suggested etiological factor, and treatment is usually symptomatic. / Histopathologically, the predominant feature of patellar tendinopathy is tendinosis, which is characterized by progressive tissue degeneration with a failed healing response and the absence of inflammatory cells. Hypercellularity with non-tenocyte phenotype cells and tissue metaplasia, including hyaline metaplasia, fibrocartilaginous metaplasia and bony metaplasia were observed in clinical patellar tendinopathy samples. The degeneration of patellar tendon in patellar tendinopathy is an active cell-mediated process rather than a passive degenerative process. Using a patellar tendinopathy animal model, we observed the presence of chondrocytic and osteoblastic phenotype / markers in patellar tendinopathy samples with or without ossification, which was consistent with the findings in clinical samples. Interestingly, chondrocyte makers were expressed by healing tendon cells at week 2 which became round prior to their expression in the chondrocyte-like cells at week 4. This leads us to speculate that erroneous differentiation of tendon-derived stem cells (TDSCs) identified recently in tendon tissues by our group, to chondrocyte / osteoblasts, due to alteration of mechanical and biological microenvironment during overuse, may lead to the ectopic chondro-ossification and failed healing in patellar tendinopathy. Osteo-chondrogenic BMPs, such as BMP-2, BMP-4 and BMP-7 might be possible factors regulating the osteo-chondrogenic differentiation of TDSCs in the pathogenesis of patellar tendinopathy. / In conclusion, our results have provided new insights about the pathological mechanisms of patellar tendinopathy involving the resident stem cells, osteo-chondrogenic BMPs and mechanical overloading. Erroneous differentiation of TDSCs to chondrocytes / osteoblasts due to ectopic osteo-chondrogenic BMP-2 expression, which were induced by repetitive tensile loading stimulation, might account for the chondro-ossification and failed healing in patellar tendinopathy. Re-directing of stem cells for tenogenic differentiation by blocking the ectopic expression of osteo-chondrogenic BMPs may help to promote tendon healing in patellar tendinoapthy. / In this study, we hypothesized that (1) TDSCs isolated from pathological patellar tendon of the CI model will exhibit higher osteogenic and chondrogenic differentiation potential but lower proliferative capacity compared to TDSCs isolated from healthy patellar tendon. Rat pathological tendon in our collagenase-induced failed healing animal model will harbor more TDSCs compared to healthy patellar tendon. (2) Osteo-chondrogenic BMPs, such as BMP-2, BMP-4, and BMP-7, will be expressed ectopically in both preclinical and clinical samples of patellar tendinopathy. (3) BMP-2 will promote osteo-chondrogenic differentiation and inhibit tenogenic differentiation of TDSCs in vitro. (4) Repetitive tensile loading will increase the expression of BMP-2 in TDSCs in vitro. / Our results showed that TDSCs isolated from the collagenase-induced tendinopathic patellar tendon of the animal model exhibited higher osteogenic/chondrogenic differentiation potential as well as lower proliferative capacity, supporting that there might be some defects in the TDSCs from the animal model, which might undergo osteo-chondrogenic differentiation and hence reduced the pool of TDSCs for tendon repair in the development of patellar tendinopathy. The higher clonogenicity and increased yield of TDSCs in tendinopathic patellar tendon might be caused by a compensation for the impaired differentiation potential and proliferative capacity of TDSCs. The histopathological features of our clinical patellar tendinopathy were characterized by tissue degeneration. Non-tenocyte phenotype cells and tissue metaplasia, such as chondrocyte-like cells and endochondral ossification were also observed. We observed the ectopic expression of osteo-chondrogenic BMP-2, BMP-4 and BMP-7 in both our animal model and clinical samples of patellar tendinopathy, which might trigger the erroneous differentiation of TDSCs to non-tenocytes. Indeed, we further showed that BMP-2 could promote the osteo-chondrogenic and inhibit tenogenic differentiation of TDSCs in vitro, which might provide a possible explanation for ectopic chondro-ossification and failed healing in patellar tendinopathy. In addition, our results also showed that in vitro repetitive cyclic tensile loading could increase the expression of BMP-2 in TDSCs, which might provide a possible explanation for the ectopic expression of BMP-2 in patellar tendinopathy. / This study aimed to compare the osteogenic / chondrogenic differentiation potential, proliferative capacity and yield of TDSCs isolated from rat healthy patellar tendon and pathological tendon in our collagenase-induced failed tendon healing animal model of patellar tendinopathy in vitro. The histopathological characteristics of our clinical patellar tendinopathy with or without ossification were examined. The ectopic expression of BMP-2, BMP-4, and BMP-7 in both human and rat samples of patellar tendinopathy was also examined. The effects of BMP-2 on the osteogenic, chondrogenic and tenogenic differentiation of TDSCs was further investigated in vitro. The effect of repetitive tensile loading on the expression of BMP-2 in TDSCs was studied in vitro. / Rui, Yunfeng. / Advisers: Kai Ming Chan; Po Yee Lui. / Source: Dissertation Abstracts International, Volume: 73-06, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 172-193). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
463

Gene expression profiling of cardinal ligament in Hong Kong Chinese women with uterine prolapse.

January 2006 (has links)
Liu Yuet Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 165-191). / Abstracts in English and Chinese. / Acknowledgement --- p.i / Abstract --- p.iii / Abbreviations --- p.vi / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Incidences and Prevalence --- p.2 / Chapter 1.2 --- Anatomy of Uterus and its Support Mechanism --- p.3 / Chapter 1.3 --- Pathophysiology of Uterine Prolapse --- p.5 / Chapter 1.4 --- Classification of Uterine Prolapse --- p.6 / Chapter 1.5 --- Etiology of Uterine Prolapse --- p.7 / Chapter 1.6 --- Treatment of Uterine Prolapse --- p.12 / Chapter 1.6.1 --- Conservative Treatment --- p.12 / Chapter 1.6.2 --- Surgical Treatment --- p.13 / Chapter 1.7 --- Molecular Basis of Uterine Prolapse --- p.14 / Chapter 1.7.1 --- Collagen Metabolism --- p.15 / Chapter 1.7.2 --- Extracellular Matrix Metabolism --- p.16 / Chapter 1.7.3 --- Advanced Glycation End-products --- p.18 / Chapter 1.7.4 --- Estrogen and Estrogen Receptors --- p.19 / Chapter 1.8 --- Gene Expression Profiling of Uterine Prolapse --- p.22 / Chapter 1.9 --- Microarray Gene Expression Profiling Analysis --- p.24 / Chapter 1.9.1 --- Types of Microarray --- p.26 / Chapter 1.9.2 --- Comparison of Oligonucleotide and cDNA Arrays --- p.31 / Chapter 1.10 --- Quantitative Real-time PCR --- p.32 / Chapter 1.10.1 --- Principle of TaqMan Real-time PCR --- p.32 / Chapter 1.10.2 --- Other Types of Real-time PCR --- p.33 / Chapter 1.11 --- Project Aims --- p.34 / Chapter 1.12 --- Significance of Study --- p.35 / Chapter CHAPTER 2 --- MATERIALS AND METHODS --- p.37 / Chapter 2.1 --- Materials --- p.37 / Chapter 2.1.1 --- Patients --- p.37 / Chapter 2.1.2 --- Cardinal Ligament Specimen --- p.38 / Chapter 2.2 --- Methods --- p.39 / Chapter 2.2.1 --- Homogenization of Cardinal Ligament Tissues --- p.39 / Chapter 2.2.2 --- Total RNA extraction --- p.39 / Chapter 2.2.3 --- Oligonucleotide Microarray --- p.41 / Chapter 2.2.3.1 --- Two-cycle cDNA Synthesis --- p.41 / Chapter 2.2.3.2 --- Cleanup of Double-stranded cDNA --- p.45 / Chapter 2.2.3.3 --- Synthesis of Biotin-labeled cRNA --- p.45 / Chapter 2.2.3.4 --- Cleanup and Quantification of Biotin-labeled cRNA --- p.46 / Chapter 2.2.3.5 --- Fragmenting the cRNA for Target Preparation --- p.47 / Chapter 2.2.3.6 --- Target Hybridization --- p.47 / Chapter 2.2.3.7 --- "Array Washing, Staining and Scanning" --- p.48 / Chapter 2.2.3.8 --- Statistical Analysis of Microarray Data --- p.49 / Chapter 2.2.4 --- Quantitative Real-time Polymerase Chain Reaction --- p.52 / Chapter 2.2.4.1 --- Primers and Probes --- p.52 / Chapter 2.2.4.2 --- Reverse Transcription --- p.53 / Chapter 2.2.4.3 --- Plate Setup --- p.53 / Chapter 2.2.4.4 --- Real-time PCR Reaction Mixture Setup --- p.54 / Chapter 2.2.4.5 --- Statistical Analysis of Real-time PCR Data --- p.54 / Chapter CHAPTER 3 --- RESULTS --- p.56 / Chapter 3.1 --- Microarray Gene Expression Data Analysis --- p.57 / Chapter 3.1.1 --- Unsupervised Gene Selection --- p.57 / Chapter 3.1.2 --- Supervised Gene Selection --- p.59 / Chapter 3.1.2.1 --- Gene Expression Profiles Distinguish Cardinal Ligament with Uterine Prolapse from Control and Identify Differentially Expressed Genes --- p.59 / Chapter 3.1.2.2 --- Gene Expression Profiles Distinguish Cardinal Ligament with Different Degrees of Uterine Prolapse from Control and Identify Differentially Expressed Genes --- p.72 / Chapter 3.1.2.3 --- Gene Expression Profiles Distinguish Cardinal Ligament with Third-degree Prolapse from First-degree Prolapse and Identify Differentially Expressed Genes --- p.92 / Chapter 3.2 --- Validation of Microarray Data by Quantitative Real-time PCR --- p.96 / Chapter 3.2.1 --- Fold Change of Candidate Genes --- p.97 / Chapter 3.2.2 --- Correlation Between Microarray and Quantitative Real-time PCR Results --- p.102 / Chapter CHAPTER 4 --- DISCUSSIONS --- p.103 / Chapter 4.1 --- Global Gene Expression Profiling using Oligonucleotide Microarray --- p.103 / Chapter 4.1.1 --- Advantages of using Affymetrix GeneChipR Microarray for Gene Expression Profiling --- p.103 / Chapter 4.1.2 --- Microarray analysis software --- p.105 / Chapter 4.1.2.1 --- DNA-Chip Analyzer Software --- p.105 / Chapter 4.1.2.2 --- Comparison of Statistical Methods for Analysis of A ffymetrix GeneChipRMicroarray Data --- p.108 / Chapter 4.2 --- Validation of Microarray Data --- p.111 / Chapter 4.2.1 --- Advantages of using Quantitative Real-time PCR for mRNA Quantification --- p.111 / Chapter 4.3 --- Microarray Gene Expression Data Analysis --- p.115 / Chapter 4.3.1 --- Unsupervised Gene Selection --- p.115 / Chapter 4.3.2 --- Supervised Gene Selection --- p.115 / Chapter 4.3.2.1 --- Gene Expression Profiles Distinguish Cardinal Ligament with Uterine Prolapse from Control and Identify Differentially Expressed Genes --- p.115 / Chapter 4.3.2.2 --- Gene Expression Profiles Distinguish Cardinal Ligament with Different Degrees of Uterine Prolapse from Control and Identify Differentially Expressed Genes --- p.118 / Chapter 4.3.2.3 --- Gene Expression Profiles Distinguish Cardinal Ligament with Third-degree Prolapse from First-degree Prolapse and Identify Differentially Expressed Genes --- p.120 / Chapter 4.4 --- Potential Genes for Further Studies in Uterine Prolapse --- p.120 / Chapter 4.5 --- Implications of This Study --- p.157 / Chapter 4.6 --- Limitations of This Study --- p.160 / Chapter CHAPTER 5 --- CONCLUSIONS --- p.162 / Chapter CHAPTER 6 --- FUTURE PROSPECT --- p.164 / REFERENCES --- p.165
464

Estudo biomecânico, em cadáver, do ângulo de flexão do joelho na fixação do enxerto autógeno na reconstrução do ligamento patelofemoral medial / Biomechanical study, in cadaver, of knee flexion angle in fixing the autograft in the reconstruction of the medial patellofemoral ligament

Sadigursky, David 21 March 2012 (has links)
O objetivo desta dissertação foi avaliar biomecanicamente o ângulo de flexão do joelho em que a fixação do enxerto do Ligamento Patelofemoral Medial (LPFM) se mostrou mais adequada. Foram estudados 12 joelhos de cadáveres, sendo que seis peças foram utilizadas para ajustes necessários no sistema. Os joelhos foram preparados em uma máquina de ensaios desenvolvida no Laboratório de Biomecânica do Instituto de Ortopedia e Traumatologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (IOT-HCFMUSP) a qual permitiu a avaliação dinâmica do comportamento patelar, quantificando a sua lateralização entre 0° e 120° graus de flexão do joelho. A técnica utilizada para a reconstrução do LPFM foi a utilização do enxerto do ligamento patelar, como apresentada por Camanho et al. em 2007. Os joelhos foram submetidos a situações de intacto, lesado e reconstruído, com e sem carga aplicada lateralmente, simulando a força de luxação da patela. Com o sistema de fotogrametria, pôde-se avaliar a lateralização da patela entre os ângulos de 0° e 120° graus de flexão do joelho. Os dados encontrados foram calculados a partir de um programa de Software conectado à máquina de ensaios. O grau de flexão do joelho foi determinado a partir de um goniômetro digital. O tensionamento do enxerto foi padronizado em 1 Kgf com a utilização de um sistema digital acoplado a uma célula de carga de 20 Kgf. As diferenças entre as distâncias encontradas, com e sem carga aplicada na patela, foram agrupadas segundo o ângulo de fixação do enxerto reconstruído em 0º, 45º, 60º e 90º e situação do joelho íntegro e lesado. Os resultados foram tabulados a partir das médias das três repetições. Os dados foram inseridos e analisados no banco de dados dos programas estatísticos STATA versão 11.0 e SAS versão 8.0. Foi realizada a Análise de Variância (ANOVA) e comparações múltiplas de Tukey(96). Houve uma tendência em ocorrer menor desvio lateral em ângulos de fixação do enxerto reconstruído acima de 30° graus de flexão, principalmente com a reconstrução realizada no ângulo de flexão do joelho, em que o ligamento foi reconstruído, de 60°graus. Para os demais ângulos não houve significância estatística / The aim of this dissertation was to make a biomechanical assessment on the knee flexion angle at which fixation of grafts for the medial patellofemoral ligament (MPFL) is seen to be best. Twelve knees from cadavers have been studied, of which six specimens were used to make necessary adjustments to the system. The knees were prepared in a test machine developed in the Biomechanics Laboratory of the Institute of Orthopedics and Traumatology, Hospital das Clínicas, School of Medicine, University of São Paulo. This enabled dynamic evaluation of the patellar component, with quantification of its lateralization between 0 and 120 degrees of flexion angle. The technique used for reconstructing the MPFL consisted of using a graft from the patellar ligament, as presented by Camanho et al. in 2007. The knees were subjected to situations in intact, injured and reconstructed states, with and without loads applied laterally, to simulate the patella dislocation force. With a photogrammetry system, the lateralization of the patella could be assessed between the knee flexion angles of 90°, 60°, 45° and 0 degrees during the graft reconstruction. The results were calculated through software coupled to the test machine. The knee flexion angle could be determined from a digital goniometer. The graft tensioning was standardized at 1 kgf by using a digital system coupled to a 20-kgf load cell. The differences between the distances found with and without load applied to the patella were grouped according to the graft fixation angle of 0°, 45°, 60° e 90°, during the reconstruction, and knee situation of intact or injured. The results were tabulated taking the mean from three repetitions. There was a tendency for less lateral deviation to occur at fixation angles of the reconstructed graft greater than 30° degrees of flexion, mainly performed in the reconstruction of the knee flexion angle of 60° degrees
465

Ocorrência de diferentes tipos de canais acessórios cavo inter-radiculares em molares de humanos. Estudo histológico /

Zuza, Elizangela Partata. January 2006 (has links)
Orientador: Benedicto Egbert Côrrea de Toledo / Banca: Marisa Aparecida Cabrini Gabrielli / Banca: Sebastião Heten / Banca: Luciene Cristina de Figueiredo / Banca: Elizabeth Pimentel Rosetti / Resumo: Apesar de haver muitos estudos que mostrem a prevalência e o diâmetro dos canais acessórios na região de furca, há escassez de trabalhos que observem o trajeto e os diferentes tipos de canais cavo inter-radiculares. Assim, o objetivo de nosso estudo foi verificar a ocorrência dos diferentes tipos morfológicos de canais acessórios na região de furca, na tentativa de mostrar os seus trajetos, através de cortes histológicos em molares de humanos. Foram utilizados 40 terceiros molares inferiores inclusos com separação radicular, os quais foram extraídos e descalcificados para a realização de microtomia no plano axial mésio-distal, obtendo-se cortes semi-seriados com espessura de 5mm. Os cortes foram corados com Hematoxilina e Eosina e observados em microscopia ótica em 40X, 100X, 200X e 400X. Os resultados mostraram que todos os tipos morfológicos foram encontrados, sendo que os canais acessórios verdadeiros, do tipo A estavam presentes em 10% dos espécimes. Os canais mais prevalentes foram os microcanais do tipo E, com prevalência de 100%, seguidos pelos fechados do tipo D com 87,5%, e pelos cegos do tipo B, com 75%. Os canais acessórios em alça, do tipo C, foram observados em apenas 5% dos dentes, sendo os menos prevalentes. / Abstract: Although there are several studies that show prevalence and diameter of accessory root canals in the furcation area, there is a scarceness of studies which observe the trajectory and different types of cavo inter-radicular canals. The objective of the present study was to verify the occurrence of different morphologic types of accessory root canals in the furcation area, in an attempt to show their trajectories, through histological sections in human molar teeth. Forty unerupted mandibular third molar teeth with radicular separation were used. They were extracted and decalcified so that microtomy could be performed towards mesio-distal axial plane, obtaining semi-serial sections with thickness of 5mm. The sections were stained with Hematoxylin and Eosin, and were observed under optical microscopy at 40X, 100X, 200X and 400X magnifications. The results showed that all morphologic types were found; the real accessory canals, type A, were present in 10% of the specimens. The most prevalent canals were type-E microcanals, with prevalence of 100%, followed by sealed type-D canals, with 87.5%, and by blind type-B canals, with 75%. The loop type-C accessory canals were observed in only 5% of the teeth and were the least prevalent. / Doutor
466

T?cnica de ressec??o do ligamento apical dorsal do p?nis no preparo de rufi?es bovinos / Technique of resection of dorsal ligament apical of the penis in the preparation of teasers bulls.

Vandesteen Junior, C?sar Augusto 29 March 2010 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2018-01-25T12:16:35Z No. of bitstreams: 1 2010 - C?sar Augusto Vandesteen Junior.pdf: 8666751 bytes, checksum: 5dc79e2a6f8c59b75d62504ea2f4fa21 (MD5) / Made available in DSpace on 2018-01-25T12:16:36Z (GMT). No. of bitstreams: 1 2010 - C?sar Augusto Vandesteen Junior.pdf: 8666751 bytes, checksum: 5dc79e2a6f8c59b75d62504ea2f4fa21 (MD5) Previous issue date: 2010-03-29 / Nowadays, in Brazil becomes necessary the attainment of methods of low cost for the detention of rutting in bovine females and one of the main traditional methods is the use of teaser bulls. These can be obtained with a great variety of surgical techniques, amongst them, the section of apical ligament, that although low cost and absence of post-surgical care, has not been practiced because of unsatisfactory results, probably due to lack of standard procedures. This study aimed to readjust this technique, considering the easy execution and low cost, standardizing it for any bovine cattle, becoming it efficient in any male bovine, from the puberty without dependence of race. 15 Parts of bovine penises in varied races and ages, varying of 12 and 28 months, had been obtained in slaughter houses for anatomic evaluations, with primacy attention in the dorsal apical ligament, getting in such a way a measure, based on statistical correlation calculations, for the attainment of the lesser density?s accurate place of this ligament and therefore the ideal place to incision and removal target ligament?s part. This measure was gotten doubling the distance between the portion proximal of the glands until the rafe of the foreskin in proximal direction from rafe of the foreskin. 16 male bovines, without emasculating had been selected and previously tested about the libido, divided in two groups of eight and submitted to the surgery of section of the apical ligament, through the measure gotten in the study of parts obtained in slaughter house, removal about five centimeters target of ligament. This procedure did not produced great post-surgical care and was gotten 100% of penis deviation, with mount without penetration, having materialize success of the technique?s readjustment. A group of bulls was introduced in the herd in the eighth surgical day after and the other in 15o day after, without difference between the two, demonstrating a reduction in the rest after surgery and becoming viable still more the technique, due to earlier teaser bulls activity. All the animals had not presented changes of behavior or reduction of libido during the 30 months of observation, demonstrated longevity of the teaser bulls gotten with this technique. / No Brasil, cada vez mais se faz necess?rio a obten??o de m?todos de baixo custo para a detec??o de cio em f?meas bovinas e um dos principais e tradicionais m?todos ? a utiliza??o de rufi?es. Estes podem ser obtidos com variadas t?cnicas cir?rgicas, dentre elas a de sec??o do ligamento apical, que apesar de baixo custo e aus?ncia de p?s operat?rio, n?o tem sido praticada devido ? obten??o de resultados n?o satisfat?rios, provavelmente devido ? falta de padroniza??o. Este estudo objetivou resgatar esta t?cnica, devido ? praticidade de execu??o e baixo custo, padronizando-a para qualquer rebanho bovino, tornando-a eficiente em qualquer bovino macho que tenha atingido a puberdade independente de ra?a. Foram estudadas 15 pe?as de matadouro de p?nis bovino de variadas ra?as e idades variando de 12 a 28 meses, com enfoque no ligamento apical dorsal, obtendo desta forma uma medida, baseada em c?lculos estat?sticos de correla??o, para a obten??o do local exato de menor densidade deste ligamento e portanto o local ideal para incis?o e extirpa??o. Esta medida foi obtida atrav?s da transloca??o da dist?ncia entre a por??o mais proximal da glande at? a rafe do prep?cio em sentido proximal a partir da rafe do prep?cio. Foram selecionados 16 bovinos machos, n?o castrados e previamente testados quanto a libido, divididos em dois grupos de oito e submetidos ? cirurgia de sec??o do ligamento apical, atrav?s da medida obtida no estudo de pe?as de matadouro, extirpando cerca de cinco cent?metros de ligamento. Este procedimento n?o gerou grandes cuidados p?s operat?rios e foi obtido 100% de desvio de p?nis com monta sem penetra??o, concretizando o sucesso do reajuste da t?cnica. Um grupo foi introduzido no rebanho no oitavo dia p?s cir?rgico e o outro no 15o dia, n?o havendo diferen?a entre os dois, demonstrando uma redu??o no repouso p?s cir?rgico e viabilizando ainda mais a cirurgia, devido ? precocidade de utiliza??o desse rufi?o. Os animais n?o apresentaram mudan?as de comportamento ou diminui??o de libido durante os 30 meses de observa??o, demonstrando longevidade do rufi?o obtido por esta t?cnica.
467

High throughput patient-specific orthopaedic analysis: development of interactive tools and application to graft placement in anterior cruciate ligament reconstruction

Ramme, Austin Jedidiah 01 May 2012 (has links)
Medical imaging technologies have allowed for in vivo evaluation of the human musculoskeletal system. With advances in both medical imaging and computing, patient-specific model development of anatomic structures is becoming a reality. Three-dimensional surface models are useful for patient-specific measurements and finite element studies. Orthopaedics is closely tied to engineering in the analysis of injury mechanisms, design of implantable medical devices, and potentially in the prediction of injury. However, a disconnection exists between medical imaging and orthopaedic analysis; whereby, the ability to generate three-dimensional models from an imaging dataset is difficult, which has restricted its application to large patient populations. We have compiled image processing, image segmentation, and surface generation tools in a single software package catered specifically to image-based orthopaedic analysis. We have also optimized an automated segmentation technique to allow for high-throughput bone segmentation and developed algorithms that help to automate the cumbersome process of mesh generation in finite element analysis. We apply these tools to evaluate graft placement in anterior cruciate ligament reconstruction in a multicenter study that aims to improve the patient outcomes of those that undergo this procedure.
468

The Effects of a New ACL-Injury Prevention Device on Knee Kinematics and Hamstring and Quadriceps Co-Contraction : A Pilot Study

Andersson, Niklas January 2013 (has links)
Background: The incidence of anterior cruciate ligament (ACL) –injury is 3-5 times greater in female athletes compared to male athletes. This may be partially attributed to lower levels of hamstring-quadriceps co-contraction in females with subsequent knee kinematics that increases risk of ACL-injury. Finding training methods that improves co-contraction and increases knee stability is important. Objectives: To evaluate the effects of a new device on hamstring-quadriceps co-contraction and to investigate if training with the device can alter knee kinematics in female athletes. Study design: Controlled experimental study design with repeated measures. Method: Twenty soccer and floor ball athletes were measured with electromyography (EMG) for hamstring-quadriceps co-contraction while performing squats with and without the device. Thirteen athletes also underwent three-dimensional kinematic analyses, measuring knee abduction angles (at initial ground contact and peak angle) during a drop jump, before and after a six week intervention period with the device. Friedman’s test and Wilcoxon signed rank test was used to assess differences and effect sizes (ES) were calculated. Results: Co-contraction was consistently larger on the device (medial side: p<0.001, ES=0.88; lateral side: p<0.001, ES=0.80) and the ratio of medial-to-lateral co-contraction increased (p=0.001, ES=0.79). In the kinematic analysis low adherence rates amongst our subjects meant that the effects of the device on kinematics could not be measured. Conclusion: Performing squats with the new training device stimulates increased hamstring-quadriceps co-contraction and increases the ratio of medial-to-lateral co-contraction. The effects of the device on knee kinematics have yet to be determined.
469

The effects of tensile loading and extracellular environmental cues on fibroblastic differntiation and extracellular matrix production by mesenchymal stem cells

Doroski, Derek M. 22 March 2011 (has links)
Ligament/tendon tissue engineering has the potential to provide therapies that overcome the limitations of incomplete natural healing responses and inadequate graft materials. While ligament/tendon fibroblasts are an obvious choice of cell type for these applications, difficulties associated with finding a suitable cell source have limited their utility. Mesenchymal stem cells/marrow stromal cells (MSCs) are seen as a viable alternative since they can be harvested through routine medical procedures and can be differentiated toward a ligament/tendon fibroblast lineage. Further study is needed to create an optimal biomaterial/biomechanical environment for ligament/tendon fibroblastic differentiation of MSCs. The overall goal of this dissertation was to improve the understanding of the role that biomechanical stimulation and the biomaterial environment play, both independently and combined, on human MSC (hMSC) differentiation toward a ligament/tendon fibroblast phenotype. Specifically, the effects of cyclic tensile stimuli were studied in a biomaterial environment that provided controlled presentation of biological moieties. The influence of an enzymatically-degradable biomaterial environment on hMSC differentiation was investigated by creating biomaterials containing enzymatically-cleavable moieties. The role that preculture may play in tensile responses of hMSCs was also explored. Together, these studies provided insights into the contributions of the biomaterial and biomechanical environment to hMSC differentiation toward a ligament/tendon fibroblast phenotype.
470

In-vitro Untersuchungen zur Gelenkstabilität und Fadenspannung nach lateraler Fadenzügelung am Kniegelenk des Hundes

Fischer, Christof 01 September 2010 (has links) (PDF)
Zielstellung: Gegenwärtig wird nach Ruptur des vorderen Kreuzbandes (VKB) beim Hund häufig eine laterale Fadenzügelungen (LFZ) vorgenommen. In der vorliegenden Arbeit wurden folgende Ziele verfolgt: (1) Bestimmung der kranio-kaudalen Kniegelenkstabilität nach LFZ und passiver Kniegelenksbewegung. (2) Bestimmung der Schlaufenspannung nach Knotung mit der Hand. (3) Einfluss von vier häufig verwendeten Verankerungsformen auf die LFZ und von drei Kniegelenkwinkeln zum Zeitpunkt der Knotung des Fadenzügels auf den Spannungsverlauf innerhalb des Fadens. Material und Methode: Die kranio-kaudale Kniegelenkstabilität (KKStab) wurde anhand von latero-medialen Röntgenaufnahmen an 10 rechten Kniegelenken orthopädisch gesunder Hunde (>20 kg KM) ex-vivo bestimmt. Die Messung der KKStab erfolgte am intakten Gelenk, nach Durchtrennung des VKB und nach lateraler Ethibondfadenzügelung. Anschließend wurden die Gelenke 350 mal passiv gebeugt und gestreckt und die KKStab nach 50, 100, 250 und 350 Bewegungszyklen erneut bestimmt. Des Weiteren wurde die Spannung in 7 Ethibondfadenschlaufen an einer Materialprüfmaschine bestimmt. Die Spannung in der Schlaufe wurde nach dem ersten (FMax) und nach dem letzten Knoten (FEnd) gemessen. Mit Hilfe eines speziell konstruierten Kraftaufnehmers wurde die Spannung in der lateralen Fadenzügelung über den passiven Bewegungsradius des Kniegelenks in weiteren 9 Kniegelenken in-vitro gemessen. Dabei wurde nach Durchtrennung des VKB jedes Kniegelenk mit 4 Formen der LFZ bei 3 unterschiedlichen Kniegelenkswinkeln zur Zeit der Fixierung der Fadenschlaufe stabilisiert. Ergebnisse: KKStab nach Stabilisierung des Gelenkes betrug im Mittel 3,7 mm und war im Mittel um 2,7 mm größer als bei intaktem Kreuzband. Bereits 250 passive Bewegungszyklen bewirkten eine signifikante Destabilisierung um weitere 1,5 mm. FMax beim Knüpfen von sieben Fadenschlaufen betrug im Mittel 133 N und fiel auf 6 N (FEnd) im Mittel nach dem fünften Knoten ab. Alle 4 untersuchten LFZ-Formen zeigten eine Zunahme der Fadenspannung bei Beugung des Kniegelenkes. Die LFZ, bei der die Zügelung um die laterale Fabella geführt und in 2 parallelen Bohrungen in der proximalen Tibia fixiert wurde, zeigte die geringsten Spannungsänderungen über einen kompletten Bewegungsradius des Kniegelenks. Die Fixation der LFZ in einen Gelenkwinkel von 70° ergab einen signifikanten Abfall der Fadenspannung in Extension des Gelenkes. Schlussfolgerungen: Eine LFZ aus Ethibondfäden mit fünffacher Knotung erlaubt es nicht, die physiologische Gelenkstabilität nach Durchtrennung des VKB herzustellen. Bereits wenige passive Bewegungszyklen bewirken eine signifikante weitere Destabilisierung. Die in diesem Teil der Studie angewendete Knotentechnik erlaubte es nicht, die manuell in der Fadenzügelung aufgebaute Spannung dauerhaft zu konservieren und sollte deshalb keine Klinische Verwendung haben. Keine der getesteten LFZ-Formen zeigte einen gleichmäßigen Spannungsverlauf bei Bewegung des Kniegelenks. Aus diesem Grund sollten die aktuellen Empfehlungen hinsichtlich „isometrischer“ Verankerungspunkte kritisch betrachtet werden. Die Fixierung der LFZ bei gebeugtem Kniegelenk ist nicht zu empfehlen, da es in Extension zur Destabilisierung kommt.

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