977 resultados para DUCTAL HYPERPLASIA


Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: Ductal carcinoma in situ (DCIS) incidence has grown with the implementation of screening and its detection varies across International Cancer Screening Network (ICSN) countries. The aim of this survey is to describe the management of screen-detected DCIS in ICSN countries and to evaluate the potential for treatment related morbidity. METHODS: We sought screen-detected DCIS data from the ICSN countries identified during 2004-2008. We adopted standardised data collection forms and analysis and explored DCIS diagnosis and treatment processes ranging from pre-operative diagnosis to type of surgery and radiotherapy. RESULTS: Twelve countries contributed data from a total of 15 screening programmes, all from Europe except the United States of America and Japan. Among women aged 50-69years, 7,176,050 screening tests and 5324 screen-detected DCIS were reported. From 21% to 93% of DCIS had a pre-operative diagnosis (PO); 67-90% of DCIS received breast conservation surgery (BCS), and in 41-100% of the cases this was followed by radiotherapy; 6.4-59% received sentinel lymph node biopsy (SLNB) only and 0.8-49% axillary dissection (ALND) with 0.6% (range by programmes 0-8.1%) being node positive. Among BCS patients 35% received SLNB only and 4.8% received ALND. Starting in 2006, PO and SLNB use increased while ALND remained stable. SLNB and ALND were associated with larger size and higher grade DCIS lesions. CONCLUSIONS: Variation in DCIS management among screened women is wide and includes lymph node surgery beyond what is currently recommended. This indicates the presence of varying levels of overtreatment and the potential for its reduction.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Several cases of Brunner's gland hyperplasia causing hemorrhage, obstruction, or intussusception have been published in the adult literature. Similar cases in the pediatric population are very rare and have only been described twice, always associated with chronic renal failure. We report the third and youngest case of gastric outlet obstruction because of Brunner's gland hyperplasia focusing on histopathologic condition and treatment based on a review of the literature.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Résumé : La découverte que des mutations du gène humain Jagged 1 (JAG1) sont la cause du Syndrome d'Alagille, indique que la voie de signalisation Notch joue un rôle prépondérant dans l'homéostasie des canaux biliaires. L'analyse fonctionnelle de cette voie de signalisation est rendue difficile par le fait que les mutations ciblées des gènes : Jagged1, Notch1 ou Notch2 présentent un phénotype létal. Dans un précédent travail, nous avions généré une souris permettant l'inactivation de Notch1 de manière inductible en combinant un transgéne inductible par l'interféron de la Cre-recombinase et le gène Notch1 flanqué de deux séquence loxP. Nous avons utilisé cette souris knock-out conditionnelle afin d'étudier le rôle de la voie de signalisation de Notch1 dans la prolifération et la différentiation cellulaire hépatique. La délétion de Notch1 ne conduit pas à une diminution du nombre des canaux biliaires, mais de manière surprenante, l'absence de Notch1 induit une prolifération continue des hépatocytes. En conclusion, en quelques semaines après l'inactivation de Notch1 les souris développent une hyperplasie nodulaire régénérative, sans modification vasculaire dans le foie. Abstract: The discovery that the human Jagged1 gene (JAG1) is the Alagille syndrome disease gene indicated that Notch signaling has an important role in bile duct homeostasis. The functional study of this signaling pathway has been difficult because mice with targeted mutations in Jagged1, Notch1, or Notch2 have an embryonic lethal phenotype. We have previously generated mice with inducible Notch1 disruption using an interferon-inducible Cre-recombinase transgene in combination with the loxP flanked Notch1 gene. We used this conditional Notch1 knockout mouse model to investigate the role of Notch1 signaling in liver cell proliferation and differentiation. Deletion of Notch1 did not result in bile duct paucity, but, surprisingly, resulted in a continuous proliferation of hepatocytes. In conclusion, within weeks after Notch1 inactivation, the mice developed nodular regenerative hyperplasia without vascular changes in the liver.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Résumé Objectif : L'hyperplasie intimale est un processus de remodelage vasculaire qui apparaît après une lésion vasculaire. Les mécanismes impliqués dans l'hyperplasie intimale sont la prolifération, la dédifférentiation et la migration des cellules musculaires lisses depuis la média vers l'espace sous-intimal. Nous avons émis l'hypothèse que les jonctions communicantes de type gap, qui coordonnent certains processus physiologiques tels que la croissance et la différentiation cellulaire, pouvaient participer au développement de l'hyperplasie intimale. Méthodes : Des segments de veines saphènes humaines prélevées chirurgicalement lors de pontages, ont été ouverts longitudinalement avec la surface luminale placée vers le haut et maintenus en culture pendant 14 jours. Des fragments veineux ont été préparés pour une évaluation histologique, pour des mesures de l'épaisseur de la néointima, et pour des analyses immunocytochimiques de l'ARN messager ainsi que des protéines. Résultats : Parmi les 4 connexines (Cxs 37, 40, 43 et 45) qui forment les jonctions communicantes dans les veines, nous avons focalisé notre étude sur l'expression des Cxs 43 et 40; nous avons démontré que la Cx43 est exprimée dans les cellules musculaires lisses et les cellules endothéliales alors que la Cx40 est uniquement présente dans l'endothélium. Après 14 jours en culture, des analyses histomorphométriques ont montré une augmentation significative de l'épaisseur de l'intima démontrant la présence d'hyperplasie intimale. Une analyse temporelle a révélé une augmentation progressive de la Cx43 jusqu'à une augmentation maximale de six à huit fois au niveau de l'ARN messager et des protéines après 14 jours en culture. Au contraire, l'expression de la Cx40 n'était pas modifiée. Des analyses par immunofluorescence ont montré également une augmentation de la Cx43 dans les membranes des cellules musculaires lisses de la média. Le développement de l'hyperplasie intimale in vitro est diminué en présence de fluvastatin et cette diminution est associée à une réduction de l'expression de la Cx43. Conclusions : Ces données démontrent que la Cx43 est augmentée in vitro pendant le processus d'hyperplasie intimale et que la fluvastatin prévient cette induction. Ces résultats suggèrent un rôle crucial joué par la communication intercellulaire impliquant la Cx43 dans la veine humaine durant le développement de l'hyperplasie intimale. Abstract Objective: Intimal hyperplasia is a vascular remodelling process that occurs after a vascular injury. The mechanisms involved in intimal hyperplasia are proliferation, dedifferentiation, and migration of medial smooth muscle cells towards the subintimal space. We postulated that gap junctions, which coordinate physiologic processes such as cell growth and differentiation, might participate in the development of intimal hyperplasia. connexin43 (Cx43) expression levels may be altered in intimal hyperplasia, and we therefore evaluated the regulated expression of Cx43 in human saphenous veins in culture in the presence or not of fluvastatin, an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity. Methods: Segments of harvested human saphenous veins, obtained at the time of bypass graft, were opened longitudinally with the luminal surface uppermost and maintained in culture for 14 days. Vein fragments were then processed for histologic examination, neointimal thickness measurements, immunocytochemistry, RNA, and proteins analysis. Results: Of the four connexins (Cx37, 40, 43, and 45), we focused on Cx43 and Cx40, which we found by real-time polymerase chain reaction to be expressed in the saphenous vein because they are the predominant connexins expressed by smooth muscle cells and endothelial cells. Afrer 14 days of culture, histomorphometric analysis showed a significant increase in the intimal thickness as observed during the process of intimal hyperplasia. Atime-course analysis revealed a progressive upregulation of Cx43 to reach a maximal increase of sixfold to eightfold at both transcript and protein levels after 14 days in culture. In contrast, the expression of Cx40, abundantly expressed in the endothelial cells, was not altered. Immunofluorescence showed a large increase in Cx43 within smooth muscle cell membranes of the media layer. The development of intimal hyperplasia in vitro was decreased in presence of fluvastatin and was associated with reduced Cx43 expression. Conclusions: These data show that Cx43 is increased in vitro during the process of intimal hyperplasia and that fluvastatin could prevent this induction, supporting a critical role for Cx43-mediated gap-junctional communication in the human vein during the development of intimal hyperplasia. (J Vasc Surg 2005;41:1043-52.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

1. Background¦Adenocarcinomas of the pancreas are exocrine tumors, originate from ductal system, including two morphologically distinct entities: the ductal adenocarcinoma and mucinous adenocarcinoma. Ductal adenocarcinoma is by far the most frequent malignant tumor in the pancreas, representing at least about 90% of all pancreas cancers. It is associated with very poor prognosis, due to the fact that actually there are no any biological markers or diagnostic tools for identification of the disease at an early stage. Most of the time the disease is extensive with vascular and nerves involvement or with metastatic spread at the time of diagnosis (1). The median survival is less than 5% at 5 years, placing it, at the fifth leading cause of death by cancer in the world (2). The mucinous form of pancreatic adenocarcinoma is less frequent, and seems to have a better prognosis with about 57% survival at 5 years (1)(3)(4).¦Each morphologic type of pancreatic adenocarcinoma is associated with particular preneoplastic lesions. Two types of preneoplastic lesions are described: firstly, pancreatic intra-epithelial neoplasia (PanIN) which affects the small and peripheral pancreatic ducts, and the intraductal papillary-mucinous neoplasm (IPMN) interested the main pancreatic ducts and its principal branches. Both of preneoplastic lesions lead by different mechanisms to the pancreatic adenocarcinoma (1)(2)(3)(4)(5)(6)(7)(8)(9)(10).¦The purpose of our study consists in a retrospective analysis of various clinical and histo-morphological parameters in order to assess a difference in survival between these two morphological types of pancreatic adenocarcinomas.¦1.2 Material and methods¦We conducted a retrospective analysis including 35 patients, (20 men and 15 women), beneficed the surgical treatment for pancreas adenocarcinoma at the Surgical Department of University Hospital in Lausanne. The patients involved in our study have been treated between 2003 and 2008, permitting at least 5-years mean follow up. For each patient the following parameters were analysed: age, gender, type of operation, type of preneoplastic lesions, TNM stage, histological grade of the tumor, vascular invasion, lymphatic and perineural invasion, resection margins, and adjuvant treatment.¦The results from these observations were included in a univariate and multivariate statistical analysis and compared with overall survival, as well as specific survival for each morphologic subtype of adenocarcinoma.¦As a low number of mucinous adenocarcinomas (n=5) was insufficient to conduct a pertinent statistical analysis, we compared the data obtained from adenocarcinomas developed on PanIN with adenocarcinomas developed on IPMN including both, ductal or mucinous types.¦1.3 Result¦Our results show that adenocarcinomas developed on pre-existing IPMN including both morphologic types (ductal and mucinous form) are associated with a better survival and prognosis than adenocarciomas developed on PanIN.¦1.4 Conclusion¦This study reflects that the most relevant parameter in survival in pancreatic adenocarcinoma seems to be the type of preneoplastic lesion. The significant difference in survival was noted between adenocarcinomas developing on PanIN as compared to adenocarcinomas developed on IPMN precursor lesions. Ductal adenocarcinomas developped on IPMN present significantly longer survival than those developed on PanIN lesions (P value= 0,01). Therefore we can suggest that the histological type of preneoplastic lesion rather than the histological type of adenocarcinoma should be the determinant prognosis factor in survival of pancreatic adenocarcinoma.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We report the 32nd case of congenital absence of portal vein in an 18-year-old female adult associated with multiple focal nodular hyperplasia of the liver. The association of various hepatic tumors has been observed in half of the publications about congenital absence of portal vein. Hepatic tumors seem to result from systemic diversion of portal vein flow with a resultant increase of arterial flow causing important vascular and nutritif changes the liver and consequent parenchymal transformation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVE: Intimal hyperplasia is a vascular remodelling process that occurs after a vascular injury. The mechanisms involved in intimal hyperplasia are proliferation, dedifferentiation, and migration of medial smooth muscle cells towards the subintimal space. We postulated that gap junctions, which coordinate physiologic processes such as cell growth and differentiation, might participate in the development of intimal hyperplasia. Connexin43 (Cx43) expression levels may be altered in intimal hyperplasia, and we therefore evaluated the regulated expression of Cx43 in human saphenous veins in culture in the presence or not of fluvastatin, an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity. METHODS: Segments of harvested human saphenous veins, obtained at the time of bypass graft, were opened longitudinally with the luminal surface uppermost and maintained in culture for 14 days. Vein fragments were then processed for histologic examination, neointimal thickness measurements, immunocytochemistry, RNA, and proteins analysis. RESULTS: Of the four connexins (Cx37, 40, 43, and 45), we focused on Cx43 and Cx40, which we found by real-time polymerase chain reaction to be expressed in the saphenous vein because they are the predominant connexins expressed by smooth muscle cells and endothelial cells. After 14 days of culture, histomorphometric analysis showed a significant increase in the intimal thickness as observed during the process of intimal hyperplasia. A time-course analysis revealed a progressive upregulation of Cx43 to reach a maximal increase of sixfold to eightfold at both transcript and protein levels after 14 days in culture. In contrast, the expression of Cx40, abundantly expressed in the endothelial cells, was not altered. Immunofluorescence showed a large increase in Cx43 within smooth muscle cell membranes of the media layer. The development of intimal hyperplasia in vitro was decreased in presence of fluvastatin and was associated with reduced Cx43 expression. CONCLUSIONS: These data show that Cx43 is increased in vitro during the process of intimal hyperplasia and that fluvastatin could prevent this induction, supporting a critical role for Cx43-mediated gap-junctional communication in the human vein during the development of intimal hyperplasia. CLINICAL RELEVANCE: Stenosis due to intimal hyperplasia is the most common cause of failure of venous bypass grafts. To better understand the development of intimal hyperplasia, we used an ex vivo organ culture model to study saphenous veins harvested from patients undergoing a lower limb bypass surgery. In this model, the morphologic and functional integrity of the vessel wall is maintained and significant intimal hyperplasia development occurs after 14 days in culture. We have postulated that gap junctions, which coordinate physiologic processes such as cell growth and differentiation, may participate in the development of intimal hyperplasia. Indeed, intimal hyperplasia consists of proliferation and migration of smooth muscle cells into the subendothelial space. Intercellular communication is responsible for the direct transfer of ions and small molecules from one cell to the other through gap-junction channels found at cell-cell appositions. No study to date has evaluated whether gap junctional communication is involved in the process of intimal hyperplasia in humans. This assertion was investigated by using the aforementioned organ culture model of intimal hyperplasia in human saphenous veins, and our data support a critical role for Cx43-mediated gap junctional communication in human vein during the development of intimal hyperplasia.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: Intimal hyperplasia (IH) is a vascular remodeling process which often leads to failure of arterial bypass or hemodialysis access. Experimental and clinical work have provided insight in IH development; however, further studies under precise controlled conditions are required to improve therapeutic strategies to inhibit IH development. Ex vivo perfusion of human vessel segments under standardized hemodynamic conditions may provide an adequate experimental approach for this purpose. Therefore, chronically perfused venous segments were studied and compared to traditional static culture procedures with regard to functional and histomorphologic characteristics as well as gene expression. MATERIALS AND METHODS: Static vein culture allowing high tissue viability was performed as previously described. Ex vivo vein support system (EVVSS) was performed using a vein support system consisting of an incubator with a perfusion chamber and a pump. EVVSS allows vessel perfusion under continuous flow while maintaining controlled hemodynamic conditions. Each human saphenous vein was divided in two parts, one cultured in a Pyrex dish and the other part perfused in EVVSS for 14days. Testing of vasomotion, histomorphometry, expression of CD 31, Factor VIII, MIB 1, alpha-actin, and PAI-l were determined before and after 14days of either experimental conditions. RESULTS: Human venous segments cultured under traditional or perfused conditions exhibited similar IH after 14 days as shown by histomorphometry. Smooth-muscle cell (SMC) was preserved after chronic perfusion. Although integrity of both endothelial and smooth-muscle cells appears to be maintained in both culture conditions as confirmed by CD31, factor VIII, and alpha-actin expression, a few smooth-muscle cells in the media stained positive for factor VIII. Cell-proliferation marker MIB-1 was also detected in the two settings and PAI-1 mRNA expression and activity increased significantly after 14 days of culture and perfusion. CONCLUSION: This study demonstrates the feasibility to chronically perfuse human vessels under sterile conditions with preservation of cellular integrity and vascular contractility. To gain insights into the mechanisms leading to IH, it will now be possible to study vascular remodeling not only under static conditions but also in hemodynamic environment mimicking as closely as possible the flow conditions encountered in reconstructive vascular surgery.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Primary hyperaldosteronism is one of the most frequent causes of secondary hypertension. Cardiovascular morbimortality is higher than in essential hypertonic and justifies diagnostic and specific treatment of this pathology. Therapeutic choice depends of health and desire of the patient. It is either medical with mineralocorticoid receptor antagonists, or surgical through adrenalectomy. In this case, a pre-surgery exam including a radiologic examination and a venous adrenal catheterism has to be done. Surgery allows a normalisation of kaliema and a blood pressure decrease in 50 to 88% of the patients. Beyond them, 30% are able to stop entirely their medication. Both therapeutic choices decrease cardiovascular risks equally if blood pressure is controlled.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Vessel wall trauma induces vascular remodeling processes including the development of intimal hyperplasia (IH). To assess the development of IH in human veins, we have used an ex vivo vein support system (EVVSS) allowing the perfusion of freshly isolated segments of saphenous veins in the presence of a pulsatile flow which reproduced arterial conditions regarding shear stress, flow rate and pressure during a period of 7 and 14 days. Compared to the corresponding freshly harvested human veins, histomorphometric analysis showed a significant increase in the intimal thickness which was already maximal after 7 days of perfusion. Expression of the endothelial marker CD31 demonstrated the presence of endothelium up to 14 days of perfusion. In our EVVSS model, the activity as well as the mRNA and protein expression levels of plasminogen activator inhibitor 1, the inhibitor of urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA), were increased after 7 days of perfusion, whereas the expression levels of tPA and uPA were not altered. No major change was observed between 7 and 14 days of perfusion. These data show that our newly developed EVVSS is a valuable setting to study ex vivo remodeling of human veins submitted to a pulsatile flow.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The diagnostics of focal nodular hyperplasia is reached through the use of imaging. When the diagnostic is certain, surgical abstention is the rule. Nevertheless, we were confronted with two cases of a rare complication; that of intraperitoneal rupture. In this situation, we suggest to first do an arteriography to control the bleeding, then to perform surgery when the patient has reached hemodynamic stability. Spontaneous rupture as a complication of benign nodular hyperplasia remains a rare event and only five cases were reported in litterature.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Résumé de l'article : L'hyperplasie intimale est un processus de remodelage vasculaire ubiquitaire après une lésion, pouvant menacer la perméabilité de tout type de reconstruction vasculaire. Les mécanismes physiopathologiques impliqués dans le développement de l'hyperplasie intimale ne sont que partiellement élucidés. Il est par conséquent nécessaire d'effectuer des recherches complémentaires afin d'en améliorer la compréhension et ainsi permettre l'élaboration de nouvelles stratégies thérapeutiques médicamenteuses. La culture de veines en milieu statique permet le développement de l'hyperplasie intimale. Ce modèle maintient la viabilité tissulaire, comme décrit précédemment dans d'autres études, mais empêche l'analyse des paramètres hémodynamiques. La mise au point d'un modèle de perfusion in vitro permettant la perfusion de segments vasculaires représente une approche expérimentale intégrant les différents facteurs hémodynamiques. Le système de perfusion (Ex Vivo Vein Support System) que nous avons élaboré conserve l'intégrité pariétale ainsi que les propriétés vasomotrices des veines pour une durée de 14 jours. Cette étude démontre que les deux modèles permettent le développement de l'hyperplasie intimale. Toutefois, les propriétés vasomotrices ainsi que l'influence des paramètres hémodynamiques ne peuvent être analysées que par l'utilisation du système de perfusion. Ce dernier a permis de perfuser des vaisseaux humains sans contamination bactérienne tout en maintenant l'intégrité cellulaire. Ce modèle de perfusion se rapproche plus des conditions hémodynamiques rencontrées in vivo que le modèle statique. Abstract : Background. Intimal hyperplasia (IH) is a vascular remodeling process which often leads to failure of arterial bypass or hemodialysis access. Experimental and clinical work have provided insight in IH development; however, further studies under precise con-trolled conditions are required to improve therapeutic strategies to inhibit IH development. Ex vivo perfusion of human vessel segments under standardized hemodynamic conditions may provide an adequate experimental approach for this purpose. Therefore, chronically perfused venous segments were studied and compared to traditional static culture procedures with regard to functional and histomorphologic characteristics as well as gene expression. Materials and methods. Static vein culture allowing high tissue viability was performed as previously described. Ex vivo vein support system (EVVSS) was performed using a vein support system consisting of an incubator with a perfusion chamber and a pump. EVVSS allows vessel perfusion under continuous flow while maintaining controlled hemodynamic conditions. Each human saphenous vein was divided in two parts, one cultured in a Pyrex dish and the other part perfused in EVVSS for 14 days. Testing of vasomotion, histomorphometry, expression of CD 31, Factor VIII, MIB 1, α-actin, and PAI-1 were determined before and after 14 days of either experimental conditions. Results, Human venous segments cultured under traditional or perfused conditions exhibited similar IH after 14 days as shown by histomorphometry. Smooth-muscle cell ( SMC) was preserved after chronic perfusion. Although integrity of both endothelial and smooth-muscle cells appears to be maintained in both culture conditions as confirmed by CD31, factor VIII and α-actin expression, a few smooth-muscle cells in the media stained positive for factor VIII. Cell-proliferation marker MIB-1 was also detected in the two settings and PAI-1 mRNA expression and activity increased significantly after 14 days of culture and perfusion. Conclusion. This study demonstrates the feasibility to chronically perfuse human vessels under sterile conditions with preservation of cellular integrity and vascular contractility. To gain insights into the mechanisms leading to IH, it will now be possible to study vascular remodeling not only under static conditions but also in hemodynamic environment mimicking as closely as possible the flow conditions encountered in reconstructive vascular surgery.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The saphenous vein is the conduit of choice in bypass graft procedures. Haemodynamic factors play a major role in the development of intimal hyperplasia (IH), and subsequent bypass failure. To evaluate the potential protective effect of external reinforcement on such a failure, we developed an ex vivo model for the perfusion of segments of human saphenous veins under arterial shear stress. In veins submitted to pulsatile high pressure (mean pressure at 100 mmHg) for 3 or 7 days, the use of an external macroporous polyester mesh 1) prevented the dilatation of the vessel, 2) decreased the development of IH, 3) reduced the apoptosis of smooth muscle cells, and the subsequent fibrosis of the media layer, 4) prevented the remodelling of extracellular matrix through the up-regulation of matrix metalloproteinases (MMP-2, MMP-9) and plasminogen activator type I. The data show that, in an experimental ex vivo setting, an external scaffold decreases IH and maintains the integrity of veins exposed to arterial pressure, via increase in shear stress and decrease wall tension, that likely contribute to trigger selective molecular and cellular changes.