Amyloidoses are a group of protein misfolding diseases characterized by deposits of insoluble fibrillar protein aggregates. Medin amyloid, which is the focus of this thesis, appears in the media of the thoracic aorta in nearly all individuals over 50 years. The fibrils are derived from a 50 amino acid residue fragment of the precursor protein lactadherin. How medin amyloid arises is unknown, but in paper I we demonstrated, with immunohistochemical and in vitro binding experiments, that both lactadherin and medin interact with elastin, implying that the elastic fibre is central in amyloid formation. In paper II, we further showed that the last 18-19 amino acid residues constitute the amyloid-promoting region. In paper III, the consequence of medin deposition was investigated. Aortic specimens from patients with thoracic aorta aneurysm and dissection were examined for medin content. The tissue findings indicated that the two disease groups contained more medin oligomers than normal aortas. Interestingly, recent reports demonstrate that the toxicity of amyloid proteins is attributed to prefibrillar oligomeric aggregates rather than to mature fibrils. In support of this finding, we observed that prefibrillar medin, in contrast to medin fibrils, was toxic in cell culture. Amyloid formation is a nucleation-dependent process. Addition of preformed fibrils to an amyloid protein solution dramatically accelerates fibrillation, a phenomenon called seeding. In paper IV, serum amyloid A-derived (AA) amyloid was found co-localized with medin deposits in the aorta. In vitro, medin fibrils enhanced the formation of AA fibrils, indicative of a seeding mechanism. The data are of great importance as they suggest that one type of amyloid is capable of inducing fibrillation and deposition of another amyloid type. In conclusion, the results of this thesis shed light on how medin is formed, the function of lactadherin and the consequences of medin deposition for aortic pathology.

Reproduction de : Thèse d'exercice : Médecine : Nancy 1 : 2003. / Thèse : 2003NAN11035. Titre provenant de l'écran-titre.

The primary purpose of this study was to determine the effectiveness of implementing desktop 3-dimensional (3D) stereo images of human anatomy into an undergraduate human anatomy distance laboratory. User perceptions of 2D and 3D images were gathered via questionnaire in order to determine ease of use and level of satisfaction associated with the 3D software in the online learning environment. Mayer's (2001, p. 184) principles of design were used to develop the study materials that consisted of PowerPoint presentations and AVI files accessed via Blackboard. The research design employed a mixed-methods approach. Volunteers each were administered a demographic survey and were then stratified into groups based upon pre-test scores. A total sample size of 62 pairs was available for combined data analysis. Quantitative research questions regarding the effectiveness of 2D versus the 3D treatment were analyzed using a doubly-multivariate repeated measures (Doubly- MANOVA) design. Paired test scores achieved by undergraduates on a laboratory practical of identification and spatial relationships of the bones and features of a human skull were used in the analysis. The questionnaire designed to gather user perceptions consisted of quantitative and qualitative questions. Response frequencies were analyzed for the two groups and common themes were noted. Results revealed a statistically significant difference in group means for the main effect of the treatment groups 2D and 3D and for the variables of identification and relationship with the 3D group outperforming the 2D group on both dependent variables. Effect sizes were determined to be small, 0.215 for the identification variable and 0.359 for the relationship variable. Overall, all students liked the convenience of using PowerPoint and AVI files online. The 3D group felt their PowerPoint was more realistic than did the 2D group and both groups appreciated the detailed labeling of the online images. One third of the volunteers in the 3D group indicated that "eye strain" was what they liked least about working with the 3D images. Results indicate that desktop, stereo imaging may be incorporated effectively into online anatomy and physiology courses, but that more work needs to be done to ensure less eye strain.

Regulation of gene expression is essential for many biological processes. Binding of transcription factors to DNA is a key regulatory step in the control of gene expression. It is commonly observed that DNA sequences with high affinity for transcription factors occur more frequently in the genome than the instances of genes bound or regulated by these factors. However, the mechanism by which transcription factors selectively identify and regulate these genes was unclear. I utilized the transcriptional control of the phosphate-responsive signaling pathway (PHO) in Saccharomyces cerevisiae as a model system to address this problem.

In this cross-sectional study, the sensibility, reliability, and validity of the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire were assessed in patients who underwent neck dissection for head and neck cancer. A sensibility questionnaire was used to assess face and content validity. Test-retest reliability was tested by re-mailing the questionnaire; validity, by evaluating differences in scores between patients undergoing different types of neck dissections and by correlating DASH scores with Neck Dissection Impairment Index (NDII) scores. The DASH was considered sensible by both patients and surgeons. The DASH was reliable with an intraclass coefficient of 0.91. The DASH showed differences between patients who underwent accessory nerve-sacrifice and nerve-sparing neck dissection. DASH scores strongly correlated with NDII scores. Thus, the DASH is a sensible, reliable, and valid instrument for assessing shoulder impairments and activity limitations following neck dissection.

Aims: To describe use of post-operative radiation for endometrial cancer in Ontario. To identify system-related and patient-related factors affecting access to this treatment. Materials and Methods: We performed a retrospective population-based cohort study of patients with surgically resected endometrial cancer in the Canadian province of Ontario between 1992-2003. Patients with evidence of incurable cancer at diagnosis or previous cancer diagnosis were excluded. We used multiple logistic regression to assess patient and system factors affecting radiation use. We controlled for disease-related and treatment-related factors: histology, surgical staging, type of hysterectomy and peritoneal biopsy. We applied a mixed model to account for clustering of data by operating hospital. Results: 9,411 women comprised the study cohort. The median age was 63 years. 26.2% received adjuvant radiation. The proportion of patients receiving radiation varied between cancer centre catchment areas from 18.0% to 34.3% (median 26.3%). In multivariate analysis, older patients were more likely to receive radiation up to the age of 80 (p<.0001). Patients who lived further from regional cancer centres were less likely to receive radiation (p=.0210). Patients who had their surgery during longer prevailing wait times at regional cancer centres were less likely to receive radiation (p=.0441). There was a 2.7-fold variation in the odds of radiation use between cancer centre catchments (p<.0001). Management at a comprehensive gynecologic oncology centre was associated with use of radiation for patients who had surgical staging of lymph nodes. Year of diagnosis and neighborhood income quintile did not significantly affect the use of radiation. Conclusions: There is wide variation in use of radiation for endometrial cancer in Ontario. There is evidence that system factors unrelated to patient’s needs affect use of adjuvant radiation for endometrial cancer in Ontario. Age is a key patient-related factor affecting radiation use. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2009-08-07 22:02:37.308

In this cross-sectional study, the sensibility, reliability, and validity of the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire were assessed in patients who underwent neck dissection for head and neck cancer. A sensibility questionnaire was used to assess face and content validity. Test-retest reliability was tested by re-mailing the questionnaire; validity, by evaluating differences in scores between patients undergoing different types of neck dissections and by correlating DASH scores with Neck Dissection Impairment Index (NDII) scores. The DASH was considered sensible by both patients and surgeons. The DASH was reliable with an intraclass coefficient of 0.91. The DASH showed differences between patients who underwent accessory nerve-sacrifice and nerve-sparing neck dissection. DASH scores strongly correlated with NDII scores. Thus, the DASH is a sensible, reliable, and valid instrument for assessing shoulder impairments and activity limitations following neck dissection.

Introdução: Existem vários fatores a serem considerados na fisiopatologia da dissecção aórtica tais como: distúrbios hemodinâmicos e os fatores relacionados às propriedades mecânicas e geométricas da parede aórtica. Os Vasa Vasorum (VV) parecem ter um importante papel em várias doenças, pois o fluxo sangüíneo insuficiente através dos VV aórticos está envolvido na fisiopatologia da aterosclerose e pode contribuir para a necrose da túnica média da aorta. Objetivo: O objetivo era demonstrar pela primeira vez as alterações histológicas que ocorrem na parede aórtica a longo prazo, ou seja, além das 2 semanas de interrupção do fluxo sangüíneo através do VV da aorta descendente em modelo suíno. Método: O experimento foi conduzido com 8 suínos jovens, idade média de 8 semanas resultantes do cruzamento das raças Landrace e Large White, pesando em média 25 Kg (21 – 27Kg) e todos os animais eram fêmeas. Por meio de uma incisão tóraco-lateral à esquerda no 6º espaço intercostal, a camada adventícia era incisada transversalmente em cerca de 1/3 da circunferência da aorta. Era então realizada a ligadura das artérias intercostais e a retirada da camada adventícia, por cerca de 5cm na porção média da aorta descendente. Após a retirada da camada adventícia a aorta era envolvida com o pericárdio bovino ao redor da área sem adventícia e então era realizado o fechamento da cavidade torácica. Após a eutanásia em duas, quatro, seis e oito semanas era realizada a retirada do segmento aórtico envolvido por pericárdio e cerca de 5 cm de aorta proximal e distal. A seguir, uma lâmina de cada segmento (proximal, médio e distal) das aortas foi corada pela Hematoxilina e Eosina e uma pelo método de Weigert – van Gieson, para coloração das fibras elásticas. Resultados: Após duas semanas observamos fibrose subendotelial com preservação da lâmina elástica interna, assim como da camada média nos seus 2/3 internos. Havia um moderado desarranjo das fibras elásticas no 1/3 externo da camada média com um leve infiltrado de linfócitos e neutrófilos. Identificaram-se também focos de angiogênese no 1/3 externo da camada média. Nos animais sacrificados após quatro semanas persistia a fibrose subendotelial com a lâmina elástica interna preservada, assim como a camada média no seu 1/3 interno. Foi identificado um desarranjo estrutural das fibras elásticas e colágenas nos 2/3 externos da camada média. Em relação à inflamação foi observado um infiltrado de linfócitos, histiócitos e neutrófilos nos 2/3 externos da camada média. Quanto à angiogênese foram observados focos nos 2/3 externos da camada média. Após seis semanas os seguintes achados foram identificados: necrose da parede da aorta com fibrose subendotelial. Em relação à inflamação foi identificada necrose com infiltrado linfocítico, histiocitário e neutrofílico em toda a camada média. Quanto à angiogênese observaram-se focos em toda a camada média e na porção subendotelial. Finalmente, após oito semanas havia fibrose de toda a parede da aorta com destruição da lâmina elástica interna. Observamos uma área de inflamação moderada próxima ao endotélio. Havia focos de angiogênese em toda a camada média e na porção subendotelial. Conclusão: O nosso estudo confirma que a isquemia induzida pela interrupção total do fluxo sanguíneo através dos vasa vasorum adventiciais leva à degenerações da túnica média, determinando perda da estrutura normal da parede aórtica que é variável em sua localização, intensidade e forma, dependendo do tempo de evolução da lesão. Em resumo, estudamos as alterações histológicas decorrentes da interrupção dos VV da aorta descendente em suínos desde a segunda semana da lesão, até que ocorresse a fibrose completa da parede. Este estudo pode contribuir para um melhor entendimento do papel dos VV na degeneração da parede aórtica e dos mecanismos envolvidos na dissecção. / Introduction: There are several factors to consider in the pathophysiology of aortic dissection, including: hemodynamic disorders and factors related to the mechanical properties and geometry of the aortic wall. The Vasa Vasorum (VV) seems to have an important role in various diseases, since insufficient blood flow through VV is involved in the pathophysiology of atherosclerosis and may contribute to necrosis of the media. Objective: To demonstrate the histological alterations that occur in aortic wall over the long term, i.e. more than two weeks after the interruption of blood flow through the VV of the descending aorta in a porcine model. Method: The experiment was conducted with eight young female pigs, resulting from the crossing of two breeds, Landrace and Large White, with a mean age of 8 weeks, weighing on average 25 kg (21 - 27 kg). Through a left thoracoabdominal incision through the 6th intercostal space, the adventitia was incised transversely in about one third of the circumference of the aorta. The intercostal arteries were then ligated and an area of the adventitia about 5 cm in length was removed from the middle portion of the descending aorta. Then, the area from which the tunica adventitia had been removed, was wrapped in bovine pericardium, after which the chest cavity was closed. Following euthanasia, at two, four, six and eight weeks, the aortic segment wrapped in pericardium was removed together with portions about 5 cm long of proximal and distal aorta. Next, slices from each segment (proximal, middle and distal) of the aorta were stained with hematoxylin and eosin (HE) and Weigert - Van Gieson method for elastic fiber staining. Results: After two weeks, subendothelial fibrosis was observed with preservation of the internal elastic lamina and the inner 2/3 of the tunica media. There was a slight cellular breakdown in the outer 1/3 of the media with some lymphocyte and neutrophil infiltration. In addition, foci of angiogenesis were identified in the outer 1/3 of the tunica media. In animals sacrificed at four weeks, persisted a subendothelial fibrosis with preservation of the internal elastic lamina and of inner 1/3 of the tunica media. There was structural breakdown of elastic fibers and collagen fibers in the outer 2/3 of the tunica media. Regarding inflammation, lymphocyte and neutrophil infiltration was observed in the outer 2/3 of the tunica media. Foci of angiogenesis were observed in the outer 2/3 of the tunica media. After six weeks, there was necrosis of the aortic wall with subendothelial fibrosis. Regarding inflammation, there was lymphocytic, histiocytic and neutrophil infiltration with necrosis throughout the media. Foci of angiogenesis were observed throughout the tunica media and in the subendothelial portion. Finally, after eight weeks, there was fibrosis of the entire wall of the aorta with destruction of the internal elastic lamina. We observed an area of moderate inflammation near the endothelium. In relation to angiogenesis, foci were observed throughout the tunica media and in the subendothelial portion. Conclusion: Our study confirms that the ischemia induced by complete interruption of blood flow through the vasa vasorum (VV) leads to degeneration of the media, determining loss of normal structure of the aortic wall that is variable in its location, intensity and shape, depending on the length and duration of the ischemic insult. In summary, we studied the histological changes caused by the interruption of the VV of the descending aorta in pigs from the second week of the injury until the occurrence of complete fibrosis of the wall at eight weeks. This study may contribute to a better understanding of the role of VV in the degeneration of the aortic wall and the mechanisms involved in aortic dissection.

Made available in DSpace on 2014-06-11T19:25:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-25Bitstream added on 2014-06-13T20:13:35Z : No. of bitstreams: 1 barbosa_cl_me_jabo.pdf: 1135689 bytes, checksum: e2af08eee19bf65284d1dccc6e211a8c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Na família Carabidae (Insecta, Coleoptera) inclui importantes espécies predadoras associadas a culturas agrícolas. A determinação do tipo de alimento utilizado por carabídeos encontra-se entre os principais aspectos considerados em estudos sobre hábitos alimentares. O presente estudo teve como objetivo avaliar o efeito de diferentes tipos de dietas sobre o consumo, viabilidade e número de ovos produzidos pelos carabídeos Abaris basistriata Chaudoir, 1873, Selenophorus seriatoporus Putzeys, 1878, Tetracha brasiliensis (Kirby, 1818), Scarites sp.2, Scarites sp.3. e determinar o tipo de material alimentar presente no aparelho digestivo dessas cinco espécies de carabídeos. As dietas avaliadas foram: larvas de Tenebrio molitor Linnaeus, 1758 (Coleoptera, Tenebrionidae), carne moída, ração para gato, pulgão Schizaphis graminum (Rondani, 1852) (Insecta, Hemiptera, Aphididae), sementes de Brachiaria decumbens Stapf (Poaceae) e mistura das dietas. Analisou-se o material presente no inglúvio e proventrículo de 10 carabídeos adultos de cada espécie coletada no campo. As espécies A. basistriata, T. brasiliensis, Scarites sp.2 e Scarites sp.3 não consumiram sementes de B. decumbens. A dieta mais consumida por adultos das cinco espécies foi larvas de T. molitor. As dietas mais favoráveis à capacidade reprodutiva de A. basistriata, S. seriatoporus e T. brasiliensis foram S. graminum e larvas de T. molitor/mistura das dietas, respectivamente. Por outro lado, as dietas de larvas de T. molitor e mistura das dietas foram as mais favoráveis para a criação de A. basistriata, S. seriatoporus e T. brasiliensis em condições de laboratório. No conteúdo alimentar de todas as espécies foram encontrado fluídos e resíduo de tegumento de artrópodes, sem contudo exibirem material vegetal. Foram identificados fragmentos de antenas, pernas, asas e mandíbulas no conteúdo alimentar de A. basistriata, T. brasiliensis, Scarites sp.2 e Scarites sp.3. / Ground beetles or carabids are collective terms for the beetle family Carabidae (Insecta, Coleoptera), which contains many species considered important predators associated with agricultural cultures. Among the main factors considered in studies on food habits is determination the type of food used by carabid. The present study aimed to evaluate the effect of different diet types on consumption, viability and number of egg produced by Abaris basistriata Chaudoir, 1873, Selenophorus seriatoporus Putzeys, 1878, Tetracha brasiliensis (Kirby, 1818), Scarites sp.2 e Scarites sp.3. and determination the type of alimentary material in the gut these five carabid. The diets assessed were: larvae of Tenebrio molitor Linnaeus, 1758 (Coleoptera, Tenebrionidae), beef mincemeat, dry cat food, the greenbug Schizaphis graminum (Rondani, 1852) (Insecta, Hemiptera, Aphididae), seeds of the signal grass Brachiaria decumbens Stapf (Poaceae) and a mixture of the diets. The material alimentary in the crop and proventriculus of 10 carabid adults of each species collected in the field we analyzed. Abaris basistriata, T. brasiliensis, Scarites sp.2 and Scarites sp.3 did not consume the B. decumbens seeds. The most consumed diet by five species was T. molitor larvae. Schizaphis graminum and T. molitor larvae / mixture were considered the diets most favourable for the reproductive capacity of A. basistriata and S. Seriatoporus/T. brasiliensis, respectively. On the other hand, T. molitor larvae and mixture of the diets were the most favorable diets for rearing A. basistriata, S. Seriatoporus and T. brasiliensis under laboratory conditions. All species showed fluid and pieces of integument of arthropods in gut, but without displaying the plant material. Some materials gut were identified as fragments of antennae, legs, wings and mandibles in alimentary content of A. basistriata, T. brasiliensis, Scarites sp.2 and Scarites sp.3.

Introdução: Existem vários fatores a serem considerados na fisiopatologia da dissecção aórtica tais como: distúrbios hemodinâmicos e os fatores relacionados às propriedades mecânicas e geométricas da parede aórtica. Os Vasa Vasorum (VV) parecem ter um importante papel em várias doenças, pois o fluxo sangüíneo insuficiente através dos VV aórticos está envolvido na fisiopatologia da aterosclerose e pode contribuir para a necrose da túnica média da aorta. Objetivo: O objetivo era demonstrar pela primeira vez as alterações histológicas que ocorrem na parede aórtica a longo prazo, ou seja, além das 2 semanas de interrupção do fluxo sangüíneo através do VV da aorta descendente em modelo suíno. Método: O experimento foi conduzido com 8 suínos jovens, idade média de 8 semanas resultantes do cruzamento das raças Landrace e Large White, pesando em média 25 Kg (21 – 27Kg) e todos os animais eram fêmeas. Por meio de uma incisão tóraco-lateral à esquerda no 6º espaço intercostal, a camada adventícia era incisada transversalmente em cerca de 1/3 da circunferência da aorta. Era então realizada a ligadura das artérias intercostais e a retirada da camada adventícia, por cerca de 5cm na porção média da aorta descendente. Após a retirada da camada adventícia a aorta era envolvida com o pericárdio bovino ao redor da área sem adventícia e então era realizado o fechamento da cavidade torácica. Após a eutanásia em duas, quatro, seis e oito semanas era realizada a retirada do segmento aórtico envolvido por pericárdio e cerca de 5 cm de aorta proximal e distal. A seguir, uma lâmina de cada segmento (proximal, médio e distal) das aortas foi corada pela Hematoxilina e Eosina e uma pelo método de Weigert – van Gieson, para coloração das fibras elásticas. Resultados: Após duas semanas observamos fibrose subendotelial com preservação da lâmina elástica interna, assim como da camada média nos seus 2/3 internos. Havia um moderado desarranjo das fibras elásticas no 1/3 externo da camada média com um leve infiltrado de linfócitos e neutrófilos. Identificaram-se também focos de angiogênese no 1/3 externo da camada média. Nos animais sacrificados após quatro semanas persistia a fibrose subendotelial com a lâmina elástica interna preservada, assim como a camada média no seu 1/3 interno. Foi identificado um desarranjo estrutural das fibras elásticas e colágenas nos 2/3 externos da camada média. Em relação à inflamação foi observado um infiltrado de linfócitos, histiócitos e neutrófilos nos 2/3 externos da camada média. Quanto à angiogênese foram observados focos nos 2/3 externos da camada média. Após seis semanas os seguintes achados foram identificados: necrose da parede da aorta com fibrose subendotelial. Em relação à inflamação foi identificada necrose com infiltrado linfocítico, histiocitário e neutrofílico em toda a camada média. Quanto à angiogênese observaram-se focos em toda a camada média e na porção subendotelial. Finalmente, após oito semanas havia fibrose de toda a parede da aorta com destruição da lâmina elástica interna. Observamos uma área de inflamação moderada próxima ao endotélio. Havia focos de angiogênese em toda a camada média e na porção subendotelial. Conclusão: O nosso estudo confirma que a isquemia induzida pela interrupção total do fluxo sanguíneo através dos vasa vasorum adventiciais leva à degenerações da túnica média, determinando perda da estrutura normal da parede aórtica que é variável em sua localização, intensidade e forma, dependendo do tempo de evolução da lesão. Em resumo, estudamos as alterações histológicas decorrentes da interrupção dos VV da aorta descendente em suínos desde a segunda semana da lesão, até que ocorresse a fibrose completa da parede. Este estudo pode contribuir para um melhor entendimento do papel dos VV na degeneração da parede aórtica e dos mecanismos envolvidos na dissecção. / Introduction: There are several factors to consider in the pathophysiology of aortic dissection, including: hemodynamic disorders and factors related to the mechanical properties and geometry of the aortic wall. The Vasa Vasorum (VV) seems to have an important role in various diseases, since insufficient blood flow through VV is involved in the pathophysiology of atherosclerosis and may contribute to necrosis of the media. Objective: To demonstrate the histological alterations that occur in aortic wall over the long term, i.e. more than two weeks after the interruption of blood flow through the VV of the descending aorta in a porcine model. Method: The experiment was conducted with eight young female pigs, resulting from the crossing of two breeds, Landrace and Large White, with a mean age of 8 weeks, weighing on average 25 kg (21 - 27 kg). Through a left thoracoabdominal incision through the 6th intercostal space, the adventitia was incised transversely in about one third of the circumference of the aorta. The intercostal arteries were then ligated and an area of the adventitia about 5 cm in length was removed from the middle portion of the descending aorta. Then, the area from which the tunica adventitia had been removed, was wrapped in bovine pericardium, after which the chest cavity was closed. Following euthanasia, at two, four, six and eight weeks, the aortic segment wrapped in pericardium was removed together with portions about 5 cm long of proximal and distal aorta. Next, slices from each segment (proximal, middle and distal) of the aorta were stained with hematoxylin and eosin (HE) and Weigert - Van Gieson method for elastic fiber staining. Results: After two weeks, subendothelial fibrosis was observed with preservation of the internal elastic lamina and the inner 2/3 of the tunica media. There was a slight cellular breakdown in the outer 1/3 of the media with some lymphocyte and neutrophil infiltration. In addition, foci of angiogenesis were identified in the outer 1/3 of the tunica media. In animals sacrificed at four weeks, persisted a subendothelial fibrosis with preservation of the internal elastic lamina and of inner 1/3 of the tunica media. There was structural breakdown of elastic fibers and collagen fibers in the outer 2/3 of the tunica media. Regarding inflammation, lymphocyte and neutrophil infiltration was observed in the outer 2/3 of the tunica media. Foci of angiogenesis were observed in the outer 2/3 of the tunica media. After six weeks, there was necrosis of the aortic wall with subendothelial fibrosis. Regarding inflammation, there was lymphocytic, histiocytic and neutrophil infiltration with necrosis throughout the media. Foci of angiogenesis were observed throughout the tunica media and in the subendothelial portion. Finally, after eight weeks, there was fibrosis of the entire wall of the aorta with destruction of the internal elastic lamina. We observed an area of moderate inflammation near the endothelium. In relation to angiogenesis, foci were observed throughout the tunica media and in the subendothelial portion. Conclusion: Our study confirms that the ischemia induced by complete interruption of blood flow through the vasa vasorum (VV) leads to degeneration of the media, determining loss of normal structure of the aortic wall that is variable in its location, intensity and shape, depending on the length and duration of the ischemic insult. In summary, we studied the histological changes caused by the interruption of the VV of the descending aorta in pigs from the second week of the injury until the occurrence of complete fibrosis of the wall at eight weeks. This study may contribute to a better understanding of the role of VV in the degeneration of the aortic wall and the mechanisms involved in aortic dissection.