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1.
Bull Exp Biol Med ; 169(4): 525-530, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32910389

RESUMO

We evaluated the efficiency of an original method for studying of the microvascular bed under conditions of normal microanatomy and pathological neovascularization. The blood vessels, tissues surrounding the stent in the pulmonary artery and subcutaneously implanted titanium nickelide plate, atherosclerotic plaque, and vascular stent with restenosis were examined. The specimens were fixed in formalin and stained in OsO4, embedded into fresh epoxy resin, grinded, polished, and counterstained with uranyl acetate and lead citrate. Numerous vasa vasorum were found in all native vessels. Around the pulmonary artery stent and metal plates, numerous newly formed vessels of small diameter were seen. The intensity of neovascularization in atherosclerosis and carotid stent restenosis differed significantly. Our technique can be successfully used for evaluation of the microvascular bed.


Assuntos
Aorta Abdominal/ultraestrutura , Microscopia Eletrônica de Varredura/métodos , Neovascularização Patológica/diagnóstico por imagem , Placa Aterosclerótica/ultraestrutura , Veia Safena/ultraestrutura , Artérias Torácicas/ultraestrutura , Animais , Aorta Abdominal/anatomia & histologia , Bovinos , Materiais Revestidos Biocompatíveis/química , Reestenose Coronária/patologia , Formaldeído , Humanos , Masculino , Neovascularização Fisiológica , Placa Aterosclerótica/patologia , Ratos , Ratos Wistar , Veia Safena/anatomia & histologia , Coloração e Rotulagem/métodos , Stents , Tela Subcutânea/patologia , Tela Subcutânea/ultraestrutura , Artérias Torácicas/anatomia & histologia , Fixação de Tecidos/métodos
2.
Circ Cardiovasc Imaging ; 7(4): 679-89, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24871347

RESUMO

BACKGROUND: The incidence of abdominal aortic aneurysms (AAAs) has increased during the last decades. However, there is still controversy about the management of medium-sized AAAs. Therefore, novel biomarkers, besides aneurysmal diameter, are needed to assess aortic wall integrity and risk of rupture. Elastin is the key protein for maintaining aortic wall tensile strength and stability. The progressive breakdown of structural proteins, in particular, medial elastin, is responsible for the inability of the aortic wall to withstand intraluminal hemodynamic forces. Here, we evaluate the usefulness of elastin-specific molecular MRI for the in vivo characterization of AAAs. METHODS AND RESULTS: To induce AAAs, ApoE(-/-) mice were infused with angiotensin-II. An elastin-specific magnetic resonance molecular imaging agent (ESMA) was administered after 1, 2, 3, and 4 weeks of angiotensin-II infusion to assess elastin composition of the aorta (n=8 per group). The high signal provided by ESMA allowed for imaging with high spatial resolution, resulting in an accurate assessment of ruptured elastic laminae and the compensatory expression of elastic fibers. In vivo contrast-to-noise ratios and R1-relaxation rates after ESMA administration were in good agreement with ex vivo histomorphometry (Elastica van Gieson stain) and gadolinium concentrations determined by inductively coupled plasma mass spectroscopy. Electron microscopy confirmed colocalization of ESMA with elastic fibers. CONCLUSIONS: Changes in elastin content could be readily delineated and quantified at different stages of AAAs by elastin-specific molecular magnetic resonance imaging. ESMA-MRI offers potential for the noninvasive detection of the aortic rupture site prior to dilation of the aorta and the subsequent in vivo monitoring of compensatory repair processes during the progression of AAAs.


Assuntos
Aorta Abdominal/química , Aneurisma da Aorta Abdominal/diagnóstico , Elastina/análise , Imageamento por Ressonância Magnética/métodos , Imagem Molecular/métodos , Animais , Aorta Abdominal/fisiopatologia , Aorta Abdominal/ultraestrutura , Aneurisma da Aorta Abdominal/metabolismo , Aneurisma da Aorta Abdominal/fisiopatologia , Modelos Animais de Doenças , Elasticidade , Masculino , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica
3.
J Surg Res ; 124(2): 305-11, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15820262

RESUMO

OBJECTIVE: Evaluation of the pig and sheep models for biocompatibility investigations of vascular prostheses (VP). DESIGN: Comparative analysis of animal experimental investigations involving two different animal models. MATERIALS AND METHODS: Commercially available polyester vascular prostheses (PET-VP) were implanted into two different animal models (infrarenal porcine aorta and ovine carotid artery). The costs, surgical handling, patency rate, and healing on the basis of macroscopic, microscopic, and immunohistochemical criteria were analyzed over a period of 3 months. RESULTS: Handling and operating times (63 +/- 10 versus 76 +/- 16 min; P = 0.125) did not differ significantly. The cost of the two animal models was comparable. Integration of the VP was complete in the sheep model, but varied in the pig model (two complete, four incomplete). Complete endothelialization of all VPs was observed in the pig, which contrasted with the sheep with complete (circular) endothelialization only in the region of the anastomosis. The thickness of neointima in the region of the anastomosis differed insignificantly; immunohistochemically, only periprosthetic Ki67 was significantly reduced (28.7 +/- 9.9 versus 6 +/- 0.9%; P = 0.002) in the sheep. CONCLUSIONS: In the porcine model, extremely good endothelialization of the VP was observed, with formation of a rapid neointimal hyperplasia. The ovine model was characterized by the fact that postoperative follow-up investigations were easy to perform. Complete endothelialization was not observed.


Assuntos
Prótese Vascular , Teste de Materiais/métodos , Modelos Animais , Ovinos , Sus scrofa , Animais , Aorta Abdominal/patologia , Aorta Abdominal/cirurgia , Aorta Abdominal/ultraestrutura , Prótese Vascular/economia , Artérias Carótidas/patologia , Artérias Carótidas/cirurgia , Artérias Carótidas/ultraestrutura , Custos e Análise de Custo , Hiperplasia , Teste de Materiais/economia , Poliésteres , Implantação de Prótese
4.
Rocz Akad Med Bialymst ; 49 Suppl 1: 187-9, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15638418

RESUMO

The aim of the study was to evaluate microscopic changes in the wall structures of allogenic arterial grafts, preserved by the method of cold ischemia in relation to the storage period and to test the possibility of the storage period prolongation by allograft freezing at -70 degrees C. The middle layer ultrastructure is well preserved till 30 days from allograft harvesting, however, allograft freezing results in total destruction of elastic and collagen fibres in the arterial wall. An application of allogenic arterial grafts, preserved by the method of cold ischemia till 30 days from their harvesting, seems an efficient therapeutic method in the treatment of patients with synthetic vascular graft infection. Further prolongation of the storage period at -70 degrees C made the allograft useless for implantation.


Assuntos
Aorta Abdominal/transplante , Artéria Femoral/transplante , Artéria Ilíaca/transplante , Transplante Homólogo/patologia , Aorta Abdominal/patologia , Aorta Abdominal/ultraestrutura , Artéria Femoral/patologia , Artéria Femoral/ultraestrutura , Humanos , Artéria Ilíaca/patologia , Artéria Ilíaca/ultraestrutura , Isquemia , Preservação de Tecido/métodos , Coleta de Tecidos e Órgãos/métodos
5.
J Vasc Interv Radiol ; 12(8): 985-9, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11487680

RESUMO

PURPOSE: To compare, with use of intravascular ultrasound (IVUS) as an internal reference standard in a porcine model, arterial diameters measured from arteriograms obtained with use of CO(2) to those obtained with use of iodinated contrast material (ICM). MATERIALS AND METHODS: In nine pigs, digital subtraction angiograms (DSAs) were obtained in the aorta and iliac arteries to compare vessel diameters measured with use of CO(2) to those measured with use of ICM. These measurements were divided by measurements made with use of intravascular ultrasound (IVUS) to yield a DSA/IVUS ratio. Differences between ICM and CO(2) were compared with analysis of variance to assess the effect of location (aorta vs iliac), contrast material used (ICM vs CO(2)), and position (posteroanterior, right anterior oblique, or left anterior oblique). Secondary analysis compared measurements of dependent and nondependent iliac arteries and compared the use of hand-injected CO(2) to that of CO(2) injected by an injector. RESULTS: The DSA/IVUS ratio was 70.7% +/- 4.4% with ICM use and 69.6% +/- 6.3% with CO(2) use, which did not represent a significant difference (P =.311). Animal position had no effect (P =.477). Underestimation was worse in the iliac arteries than in the aorta (67.4% +/- 1.5% vs 71.4% +/- 1.7%; P =.038). There was no difference in nondependent (P =.163) arteries, but CO(2) underestimated dependent iliac artery size more than ICM did (66.3% +/- 4.8% vs 70.3% +/- 5.4%; P =.051). Vessel diameter was underestimated more with the CO(2) injector than with hand-injected CO(2) (64.3% +/- 2.3% vs 71.7% +/- 1.7%; P <.0001). CONCLUSION: There is no difference in diameter underestimation between CO(2) and ICM in this animal model. Hand-injection of CO(2) causes less underestimation of vessel diameter than does the CO(2) injector.


Assuntos
Angiografia/métodos , Aorta Abdominal/ultraestrutura , Dióxido de Carbono , Meios de Contraste , Artéria Ilíaca/diagnóstico por imagem , Iodo , Animais , Aorta Abdominal/diagnóstico por imagem , Cobaias , Modelos Animais , Ultrassonografia
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