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Problematika kritické končetinové ischemie a buněčné léčby u syndromu diabetické nohy, patogenetické aspekty Charcotovy osteopatie. / Critical limb ischemia and autologous cell therapy in diabetic foot disease, pathogenesis of Charcot osteoarthopathy.Němcová, Andrea January 2020 (has links)
Diabetic foot disease (DFD) is a serious complication of diabetes and, along with critical limb ischemia, significantly exacerbates the prognosis of patients. Peripheral arterial disease in patients with diabetes has an atypical clinical course, its diagnosis is challenging and is one of the most common causes of morbidity and mortality of patients with DFD. The aim of this dissertation focused on the diagnosis and treatment of DFD was to identify a suitable method for evaluating the effect of autologous cell therapy (ACT), to assess options for early diagnosis of Charcot osteoarthropathy (COA) and, possibly, to establish the association between the incidence of cardiovascular disease and DFD. In our studies concerning therapeutic vasculogenesis, we observed a significant increase in the antiangiogenic factor endostatin after ACT in contrast to its unchanged levels after standard percutaneous transluminal angioplasty; the transient increase in endostatin seems to be a marker of therapeutic vasculogenesis after ACT. A benefit of using calf muscle perfusion scintigraphy in the assessment of microcirculation and ACT effect was not clearly demonstrated. By contrast, a promising method for the evaluation of microcirculation and the effect of revascularization after ACT was MR spectroscopy of calf...
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The role of COCO in ocular angiogenesisPopovic, Natalija 04 1900 (has links)
Contexte: La néovascularisation pathologique oculaire entraîne plusieurs troubles de la cécité, y
compris la dégénérescence maculaire néovasculaire liée à l'âge (nDMLA) et la rétinopathie de la
prématurité (ROP). La nDMLA est la principale cause de cécité dans le monde industrialisé avec
un impact socio-économique considérable (1-6). Les thérapies palliatives actuelles reposent sur
la suppression du facteur de croissance de l'endothélium vasculaire (VEGF), prouvé sûr et efficace
(7-19). Cependant, certains patients résistent aux injections intravitréennes mensuelles répétées
d'anti-VEGF, et les conséquences à long terme comprennent une perte de vision supplémentaire
et une atrophie géographique (10, 14, 17, 18, 20-27). Cliniquement, il existe un besoin de
nouvelles cibles combinatoires ou alternatives dans les cliniques, permettant de réduire les doses
d'anti-VEGF, de traiter et d'étendre un intervalle approprié personnalisé à chaque patient non
répondeur, et de minimiser la charge des injections répétées (24, 25, 28, 29).
La famille TGF-β et sa sous-famille BMP sont cruciales dans l'angiogenèse oculaire physiologique
dans un modèle de ROP, et pourraient être des cibles thérapeutiques potentielles chez les
patients souffrant d’une nDMLA (30-66).
Hypothèse: COCO, un membre de la famille DAN, un modulateur connu des voies BMP et TGF-β,
agit comme un facteur neurotrophique sur les progéniteurs de photorécepteurs humains en
culture. Nous émettons l'hypothèse que les effets neurotrophiques et anti-angiogéniques de
COCO pourraient être des approches thérapeutiques bénéfiques pour empêcher la
néovascularisation dans la nDMLA ou la ROP.
Objectifs:
Objectif 1: Pour évaluer le rôle du COCO sur les maladies oculaires néovasculaires, nous
proposons d'étudier ses effets sur la néovascularisation rétinienne et choroïdienne dans le
développement et des modèles pathologiques de la DMLA et de la ROP lors d'injections
intravitréennes.
Objectif 2: Pour comprendre le rôle physiologique et le mécanisme d'action du COCO, nous
évaluerons les effets de COCO endogène au cours de l'angiogenèse et du développement
vasculaire oculaire.
Conclusions: Nous avons découvert un nouvel inhibiteur de l'angiogenèse, COCO, un membre de
la famille des protéines DAN. COCO abroge la migration et la prolifération des cellules
endothéliales de la veine ombilicale humaine, en partie grâce à sa régulation des voies TGF-β et
BMP et à une modification du métabolisme cellulaire et des gènes mitochondriaux.
Les injections intravitréennes de COCO suppriment la vascularisation rétinienne en cours du
développement et dans un modèle expérimental de ROP. COCO inhibe de la même manière la
néovascularisation choroïdienne dans un modèle de DMLA. De plus, COCO empêche
l'angiogenèse rétinienne développementale sans affecter le système vasculaire mature.
L'examen des souris Dand5 (COCO) KO a également montré un phénotype de développement
rétinien léger à P12 ainsi qu'une exacerbation des touffes néovasculaires dans un modèle de
rétinopathie induite par l'oxygène.
Impact: Nos données montrent que COCO inhibe la néovascularisation rétinienne et
choroïdienne et pourrait être une nouvelle thérapie possible pour des maladies oculaires. Nos
études fournissent des données sur les impacts de COCO sur le développement vasculaire
rétinien, établissent ses caractéristiques moléculaires et déterminent son importance biologique. / Background: Ocular pathological neovascularization leads to several blinding disorders, including
neovascular age‐related macular degeneration (nAMD) and retinopathy of prematurity (ROP).
nAMD, for instance, is the primary cause of blindness in the industrialized world with a
tremendous socioeconomic impact (1-6). Current palliative therapies rely on suppressing
vascular endothelial growth factor (VEGF), proven safe and effective (7-19). However, some
patients are resistant to monthly repeated intravitreal injections of anti-VEGF, and long-term
consequences comprise further vision loss and geographic atrophy (10, 14, 17, 18, 20-27).
Clinically, there is a necessity for novel combinatory or synergistic therapeutic targets to reduce
anti-VEGF treatment adherence. Novel personalized therapies to each non-responder patient
may increase efficiency while minimizing the burden of repeated injections (24, 25, 28, 29). The
TGF-β family, specifically the BMPs subfamily of proteins, is crucial in pathological ocular
angiogenesis in a model of pre-retinal neovascularization. These alternative pathways could be
potential therapeutic targets in nAMD patients as well (30-66).
Hypothesis: COCO, a member of the DAN family, is a known modulator of BMP and TGF-β
pathways and acts as a neurotrophic factor on cultured human photoreceptor progenitors. We
hypothesize that COCO’s neurotrophic and anti-angiogenic effects could exert therapeutic
benefits to preclude neovascularization in nAMD or ROP.
Objectives:
Aim 1: To assess the role of COCO on neovascular ocular diseases, we propose investigating its
effects on retinal and choroidal neovascularization in the development and pathological models
of AMD and ROP upon intravitreal injections.
Aim 2: To understand COCO's physiological role and mechanism of action, we evaluate the
exogenous and endogenous effects of COCO during angiogenesis and ocular vascular
development.
Conclusions: We discovered a novel inhibitor of angiogenesis, COCO, a DAN protein family
member. COCO abrogated sprouting migration and cellular proliferation of human umbilical vein
endothelial cells, partly through its regulation of TGF-β and BMP pathways and cellular
metabolism.
Intravitreal injections of COCO suppress retinal vascularization in development and an
experimental model of ROP. COCO similarly inhibits choroidal neovascularization in an nAMD
model. COCO prevents developmental retinal angiogenesis without affecting the mature
vasculature. Examination of Dand5 (COCO) KO mice also shows a mild retinal developmental
phenotype at P12 as well as an exacerbation of neovascular tufts in a model of oxygen-induced
retinopathy.
Impact: Our data show that COCO inhibits retinal and choroidal neovascularization and could be
of potential therapeutic use in treating neovascular ocular diseases. Our studies set grounds for
understanding the role of COCO during retinal vascular development, characterizing its molecular
features, and determining its biologic significance.
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Etude des flux sanguins dans le placenta humain et influence du shear stress sur la fonction biologique du syncytiotrophoblasteLecarpentier, Edouard 06 October 2016 (has links)
La placentation humaine est de type hémomonochoriale, le sang maternel est directement en contact avec le syncytiotrophoblaste. Les flux sanguins maternels, dans la chambre intervilleuse, exercent des forces mécaniques de cisaillement (shear stress) sur la surface microvillositaire du syncytiotrophoblaste. Les effets physiologiques du shear stress exercé par les flux sanguins sur l’endothélium vasculaire artériel et veineux ont fait l’objet de nombreux travaux scientifiques. En revanche, les effets biologiques du shear stress sur le syncytiotrophoblaste humain n’ont jamais été explorés. L’objectif de ce travail était premièrement d’évaluer les valeurs du shear stress exercé in vivo sur le syncytiotrophoblaste humain au cours des grossesses normales, puis de mettre au point un modèle de culture primaire dynamique afin de reproduire les conditions physiologique et d’étudier in vitro la réponse biologique du syncytiotrophoblaste au shear stress. En dépit d’un débit sanguin maternel intraplacentaire important, estimé entre 400 et 600 mL.min-1, le shear stress moyen exercée par le syncytiotrophoblaste est estimée entre 0.5±0.2 et 2.3±1.1 dyn.cm-2. Nos résultats montrent cependant que l’intensité du shear stress est très hétérogène tant à l’échelle de la chambre intervilleuse que de la villosité terminale. Nous avons développé un modèle de culture cellulaire dynamique en condition de flux adapté au syncytiotrophoblaste humain. Ce modèle permet d’appliquer un shear stress égal et constant sur toutes les cellules cultivées et reproductible à chaque culture primaire. Aux gammes de shear stress étudiées (1 dyn.cm-2), nous n’avons pas mis en évidence de diminution de la viabilité cellulaire ni de déclenchement des processus précoces d’apoptose en conditions dynamiques comparativement aux conditions statiques. Deux types de chambre de perfusion permettent d’étudier des réponses cellulaires au shear stress à court et long terme selon des temps d’exposition allant de 5 minutes à 24 heures. Ce modèle expérimental a permis de montrer que le syncytiotrophoblaste humain en culture primaire est mécanosensible. La réponse cellulaire à des niveaux de shear stress de 1 dyn.cm-2 est multiple selon les temps d’exposition et le niveau d’intégration étudié. Après 45 minutes de shear stress les taux d’AMP cyclique intracellulaires sont augmentés ce qui a pour effet d’activer la voie de signalisation intracellulaire PKA-CREB. Cette augmentation d’AMP cyclique est secondaire à la synthèse et la libération de prostaglandine E2 qui, par une boucle de régulation autocrine stimule l’adenylate cyclase. L’augmentation de la synthèse/libération de PGE2 est dépendante de l’augmentation rapide du calcium intracellulaire sous shear stress. L’exposition au shear stress de 24 heures stimule l’expression et la sécrétion du PlGF, un facteur de croissance indispensable à l’angiogenèse placentaire et pour l’adaptation maternelle à la grossesse sur le plan vasculaire. Nos travaux montrent que l’augmentation de l’AMPc intracellulaire et l’activation de la PKA contribuent à la phosphorylation de CREB, facteur de transcription régulant l’expression du PlGF. / Human placentation is hemomonochorial, maternal blood circulates in direct contact with the syncytiotrophoblast. In the intervillous space, the maternal blood exerts frictional mechanical forces (shear stress) on the microvillous surface of the syncytiotrophoblast. Flowing blood constantly exerts a shear stress, on the endothelial cells lining blood vessel walls, and the endothelial cells respond to shear stress by changing their morphology, function, and gene expression. The effects of shear stress on the human syncytiotrophoblast and its biological functions have never been studied. The objectives of this study were (1) to determine in silico the physiological values of shear stress exerted on human syncytiotrophoblast during normal pregnancies, (2) to develop a model reproducing in vitro the shear stress on human syncytiotrophoblast and (3) to study in vitro the biological response of human syncytiotrophoblast to shear stress. The 2D numerical simulations showed that the shear stress applied to the syncytiotrophoblast is highly heterogeneous in the intervillous space. In spite of high intraplacental maternal blood flow rates (400-600mL.min-1), the estimated average values of shear stress are relatively low (0.5±0.2 to 2.3±1.1 dyn.cm-2). To study the shear stress-induced cellular responses during exposure times ranging from 5 minutes to 24 hours we have developed two dynamic cell culture models adapted to the human syncytiotrophoblast. We found no evidence of decreased cell viability or early processes of apoptosis in dynamic conditions (1 dyn.cm-2, 24h) compared to static conditions. Shear stress (1 dyn.cm-2) triggers intracellular calcium flux, which increases the synthesis and release of PGE2. The enhanced intracellular cAMP in FSS conditions was blocked by COX1/COX2 inhibitors, suggesting that the increase in PGE2 production could activate the cAMP/PKA pathway in an autocrine/paracrine fashion. FSS activates the cAMP/PKA pathway leading to upregulation of PlGF in human STB. Shear stress-induced phosphorylation of CREB and upregulation of PlGF were prevented by inhibition of PKA with H89 (3 μM). The syncytiotrophoblast of the human placenta is a mechanosenstive tissue.
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Estudo imuno-histoqu?mico da express?o da GLUT-1 e mensura??o do ?ndice angiog?nico (CD34) em adenomas pleom?rficos, carcinomas aden?ides c?sticos e carcinomas mucoepiderm?ides de gl?ndulas salivaresOliveira, Lucileide Castro de 27 June 2012 (has links)
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Previous issue date: 2012-06-27 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The expression of glucose transporter protein 1 (GLUT-1), as well the angiogenesis has been associated to clinical behavior and aggressiveness in tumors of various origin. It is believed that the expression of this protein denotes metabolic demand of the tumor cells and, thus its influence upon the formation of new blood vessels. Pleomorphic adenoma (PA) and the adenoid cystic carcinoma (ACC) and mucoepidermoid carcinoma (MEC) represent, respectively, the most commom benign and malignant tumors of salivary glands. The aim of this study was to analyze and compare the immunohistochemical expression of GLUT-1 and its correlation with angiogenesis in cases of PAs, ACCs and MECs considering their histological grades. The sample consisted of 20 PAs, 20 ACCs and 10 MECs. The cases were analyzed and classified according to their histological grades. The expression of GLUT-1 was evaluated in the parenchyma lesions, establishing the percentage of immunopositive cells, according to the following scores: 0 (no cell immunomarked), 1 (up to 25% of tumor cells immunostained), 2 (25 - 50% of tumor cells immunostained) and 3 (more than 50% of tumor cells immunostained). The angiogenic index was analyzed by counting the microvessels immunostained by anti-CD34 antibody, in 5 fields (200X). The analysis of the expression of GLUT-1 in tumor parenchyma showed statistically significant differences between benign and malignant groups (p = 0.022). The average number of microvessels in PAs was 40.4, 21.2 in ACCs and 66.5 in MECs, with significant differences between groups (p <0.001). When compared to the expression of GLUT-1 and angiogenic index as a whole, there was no significant correlation between the number of microvessels and the expression of GLUT-1 (r = 0.211, p = 0.141). In conclusion, the results of this study suggest not only that differences in biological behavior between PAs, ACCs and MECs may be associated to the expression of GLUT-1, but also that benign and malignant salivary gland present differences in the average number of microvessels, with higher levels considered more aggressive tumors. Furthermore, the number of newly formed microvessels can be independent of the metabolic demand of the tumor cells / A express?o da prote?na transportadora de glicose tipo 1 (GLUT-1), bem como a angiog?nese, t?m sido relacionadas ao comportamento cl?nico e agressividade em neoplasias de origem diversas. Acredita-se que a express?o desta prote?na denote a demanda metab?lica das c?lulas tumorais e, assim, a sua influ?ncia na forma??o de novos vasos sanguineos. O adenoma pleom?rfico (AP) e o carcinoma adenoide c?stico (CAC) e carcinoma mucoepiderm?ide (CME) representam, respectivamente, a neoplasia benigna e as malignas mais frequentes das gl?ndulas salivares. O prop?sito deste estudo foi comparar a express?o imuno-histoqu?mica da GLUT-1, bem como correlacionar com a angiog?nese em casos de APs, CACs e CMEs levando em considera??o suas grada??es histol?gicas. A amostra foi composta por 20 APs, 20 CACs e 10 CMEs os quais foram classificados de acordo com os graus histol?gicos apresentados. A express?o da GLUT-1 foi avaliada no par?nquima das les?es, estabelecendo-se o percentual de c?lulas imunopositivas, de acordo com os escores: 0 (nenhuma c?lula imunomarcada), 1 (at? 25% das c?lulas tumorais imunomarcadas), 2 (de 25-50% das c?lulas tumorais imunomarcadas) e 3 (mais de 50% das c?lulas tumorais imunomarcadas). O ?ndice angiog?nico foi analisado por meio da contagem de microvasos imunomarcados pelo anticorpo anti-CD34, em 5 campos (200x). A an?lise da express?o da GLUT-1 revelou diferen?as estatisticamente significativas entre os grupos benignos e malignos (p = 0,022). O n?mero m?dio de microvasos foi de 40,4 em APs, 21,2 em CACs e 66,5 em CMEs, com diferen?as significativas entre os grupos (p < 0,001). Quando comparadas a express?o da GLUT-1 com o ?ndice angiog?nico em conjunto, n?o foi evidenciada correla??o significativa entre a quantidade de microvasos e a express?o da GLUT-1 (r = 0,211; p = 0,141). Os resultados do presente estudo sugerem que as diferen?as no comportamento biol?gico entre APs, CACs e CMEs podem estar relacionadas ? express?o da GLUT-1 e que tumores benignos e malignos de gl?ndulas salivares exibem diferen?as no n?mero m?dio de microvasos, com maiores ?ndices nos tumores considerados mais agressivos. Al?m disto, o n?mero de microvasos neoformados pode ser independente da demanda metab?lica das c?lulas tumorais
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Estudo da imunoexpress?o de RANKL e OPG, do ?ndice angiog?nico (CD34) e da presen?a de miofibroblastos (?-SMA) em ceratocistos odontog?nicos isolados e associados ? s?ndrome de GorlinNonaka, Cassiano Francisco Weege 23 September 2010 (has links)
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Previous issue date: 2010-09-23 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The odontogenic keratocysts are distinguished from other odontogenic cystic lesions by their potentially aggressive clinical behavior and association, in some cases, with Gorlin syndrome. Studies have suggested that syndrome keratocysts, in comparison with sporadic lesions, have higher growth and infiltration capacity and higher recurrence tendency. The aim of this study was to analyze, by means of immunohistochemistry, the expressions of receptor activator of nuclear factor ?B ligand (RANKL) and osteoprotegerin (OPG), the angiogenic index (CD34) and the presence of myofibroblasts (?-SMA) in primary and recurrent sporadic keratocysts and in keratocysts associated with Gorlin syndrome. The sample was composed by 30 sporadic keratocysts (22 primary and 8 recurrent) and 22 syndrome keratocysts. In the epithelium and in the fibrous capsule of the lesions, the immunoexpression of RANKL and OPG was evaluated by determination of the percentage of positive cells, according to the following scores: 0 (less than 10% of positive cells), 1 (11% - 50% of positive cells), 2 (51% - 75% of positive cells) and 3 (more than 76% of positive cells). In addition, cases were classified according to the RANKL score/ OPG score ratio, as follows: RANKL > OPG, RANKL < OPG, and RANKL = OPG. The angiogenic index was analyzed by counting the microvessels immunoreactive to anti-CD34 antibody in 5 fields (200?). The analysis of myofibroblasts was performed by counting the cells immunoreactive to anti-?-SMA antibody in 10 fields (400?). The analysis of the expressions of RANKL and OPG in the epithelial lining and in the fibrous capsule did not reveal significant differences between groups (p > 0.05). Regarding the RANKL/ OPG ratio in the epithelial lining, most sporadic primary (54.5%) and syndrome lesions (59.1%) showed RANKL < OPG ratio and RANKL = OPG ratio, respectively (p > 0.05). With respect to the RANKL/ OPG ratio in the fibrous capsule, the majority of sporadic primary (81.8%) and sporadic recurrent lesions (75.0%) and most syndrome lesions (45.5%) showed RANKL = OPG ratio (p > 0.05). The mean number of microvessels was 69.2 in sporadic primary lesions, 67.6 in recurrent lesions, and 71.6 in syndrome lesions, with no significant differences between groups (p > 0.05). The mean number of myofibroblasts was 34.4 in sporadic primary lesions, 29.3 in recurrent lesions, and 33.7 in syndrome lesions, with no significant differences between groups (p > 0.05). In conclusion, the results of the present study suggest that the differences in the biological behavior between sporadic keratocysts and keratocysts associated with Gorlin syndrome may not be related to the expressions of RANKL and OPG, the RANKL/ OPG ratio, the angiogenic index or the number of myofibroblasts in these lesions / Os ceratocistos odontog?nicos se destacam em rela??o a outras les?es c?sticas odontog?nicas pelo comportamento cl?nico potencialmente agressivo e por se apresentarem associados, em alguns casos, ? s?ndrome de Gorlin. Estudos t?m sugerido que os ceratocistos sindr?micos, em compara??o ?s les?es isoladas, possuem maior capacidade de crescimento e infiltra??o e maior tend?ncia ? recorr?ncia. O objetivo do presente trabalho consistiu em analisar, por meio de imuno-histoqu?mica, as express?es do ligante do receptor ativador do fator nuclear ?B (RANKL) e da osteoprotegerina (OPG), o ?ndice angiog?nico (CD34) e a presen?a de miofibroblastos (?-SMA), em ceratocistos isolados prim?rios e recorrentes e ceratocistos associados ? s?ndrome de Gorlin. A amostra foi composta por 30 ceratocistos isolados (22 prim?rios e 8 recorrentes) e 22 ceratocistos sindr?micos. A express?o de RANKL e OPG foi avaliada no epit?lio e na c?psula fibrosa das les?es, estabelecendo-se o percentual de c?lulas imunopositivas, de acordo com os escores: 0 (? 10% das c?lulas positivas), 1 (11% - 50% das c?lulas positivas), 2 (51% - 75% das c?lulas positivas) e 3 (? 76% das c?lulas positivas). Al?m disso, os casos foram categorizados, segundo a propor??o RANKL/ OPG, em: RANKL > OPG, RANKL < OPG e RANKL = OPG. O ?ndice angiog?nico foi analisado por meio da contagem dos microvasos imunomarcados pelo anticorpo anti-CD34, em 5 campos (200?). Para a avalia??o dos miofibroblastos, foram quantificadas as c?lulas imunorreativas ao anticorpo anti-?-SMA, em 10 campos (400?). A an?lise das express?es de RANKL e OPG, no revestimento epitelial e na c?psula fibrosa, n?o revelou diferen?as significativas entre os grupos (p > 0,05). Em rela??o ? propor??o RANKL/ OPG no revestimento epitelial, grande parte das les?es isoladas prim?rias (54,5%) e sindr?micas (59,1%) exibiu propor??o RANKL < OPG e propor??o RANKL = OPG, respectivamente (p > 0,05). Em rela??o ? propor??o RANKL/ OPG na c?psula fibrosa, a maioria das les?es isoladas prim?rias (81,8%) e isoladas recorrentes (75,0%) e grande parte das les?es associadas ? s?ndrome de Gorlin (45,5%) revelaram propor??o RANKL = OPG (p > 0,05). O n?mero m?dio de microvasos foi de 69,2 nas les?es isoladas prim?rias, 67,6 nas les?es recorrentes e 71,6 nas les?es sindr?micas, sem diferen?as significativas entre os grupos (p > 0,05). A an?lise dos miofibroblastos revelou valores m?dios de 34,4 nas les?es isoladas prim?rias, 29,3 nas les?es recorrentes e 33,7 nas les?es sindr?micas, sem diferen?as significativas entre os grupos (p > 0,05). Em conclus?o, os resultados do presente estudo sugerem que as diferen?as no comportamento biol?gico entre ceratocistos isolados e associados ? s?ndrome de Gorlin podem n?o estar relacionadas ?s express?es de RANKL e OPG, ? propor??o RANKL/ OPG, ao ?ndice angiog?nico ou ? quantidade de miofibroblastos presentes nas les?es
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Malformation artério-veineuses cérébrales : d'une amélioration des techniques d'imagerie vers un changement de paradigme des traitements / Brain arteriovenous malformations : from imaging technique improvement toward treatment paradigm shiftClarençon, Frédéric 11 December 2014 (has links)
Les malformations artério-‐veineuses cérébrales (MAVc) sont des pathologies vasculaires agressives présentant un risque hémorragique lourd de conséquence en terme de morbi-‐mortalité. Les outils d’imagerie disponibles actuellement ne permettent de comprendre que difficilement leur angio-‐ architecture. Nous avons développé dans notre travail deux outils d’imagerie permettant d’affiner la compréhension de l’anatomie des ces malformations : un algorithme de segmentation semi-‐automatisé et un algorithme d’anamorphose sphérique convexe. Ces algorithmes ont été élaborés pour être utilisés sur les acquisitions d’angiographie rotationnelle 3D ; ils permettent de mieux visualiser la veine de drainage principale des MAVc, notamment d’identifier une sténose ou une ectasie focale sur cette veine, et également de déceler de façon plus fiable la présence d’un anévrysme intra-‐nidal. Ces améliorations dans l’analyse de l’angio-‐architecture des MAVc permettront vraisemblablement de réduire le risque thérapeutique pour ces malformations. En vue de tester le potentiel des agents anti-‐angiogéniques pour le traitement des MAVc, nous avons élaboré un modèle porcin simplifié de MAVc consistant en une occlusion unilatérale d’artère carotide primitive par voie endovasculaire. La comparaison entre le volume de rete mirabile à J0 et à 3 mois et les valeurs obtenues pour un groupe témoin a montré une augmentation significative du volume du rete mirabile chez les porcs ayant eu l’occlusion carotidienne. D’autre part, une tendance nette à l’augmentation des taux de VEGF (vascular endothelial growth factor) à proximité du rete mirabile était observée dans le groupe occlusion. Enfin, des modifications anatomopathologiques proches de celles des MAVc humaines étaient visualisées sur les pièces autopsiques des rete mirabile dans le groupe occlusion. / Brain arteriovenous malformations (bAVMs) are aggressive vascular malformations presenting a haemorrhagic complication risk that may lead to severe consequences in terms of morbi-‐mortality. Available imaging tools poorly help in understanding their angio-‐architecture. We have developed two imaging tools improving our understanding of the anatomy of these malformations: a semi-‐automated segmentation algorithm and a convex spherical anamorphosis algorithm. These algorithms have been elaborated for use on 3D rotational angiography acquisitions; they provide a better visualisation of the bAVMs’ main draining vein, especially for venous stenosis or for focal ectasia. They also help in depicting accurately intranidal aneurysms. These improvements in the analysis of the bAVMs’ angioarchitecure may help in reducing the therapeutic risk for these malformations. For a further testing of the potential of anti-‐angiogenic agents for the treatment of bAVMs, we have elaborated a simplified swine AVM model consisting in the occlusion of a common carotid artery by endovascular means. The comparison between the volume of the rete mirabile at D0 and 3 months and those measured in a control group showed a significant increasing of the retia in the occlusion group. Moreover, a tendency was observed concerning an increase in VEGF (vascular endothelial growth factor) serum levels close to the rete mirabile in the occlusion group. Finally, pathological changes close to those seen in human bAVMs were observed on autopsy samples in the occlusion group.
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