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Статті в журналах з теми "Tissu vascularisé"
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Hannen, Egied J. M., Jeroen A. W. M. van der Laak, Harold M. J. Kerstens, Vincent M. J. I. Cuijpers, Antonius G. J. M. Hanselaar, Johannes J. Manni, and Peter C. M. de Wilde. "Quantification of Tumour Vascularity in Squamous Cell Carcinoma of the Tongue Using CARD Amplification, a Systematic Sampling Technique, and True Colour Image Analysis." Analytical Cellular Pathology 22, no. 4 (2001): 183–92. http://dx.doi.org/10.1155/2001/780576.
Повний текст джерелаАнотація:
The aims of this study of head and neck tissue samples were to develop an immunohistochemical protocol based on the catalysed reporter deposition (CARD) technique to enhance staining results for use in automated true colour image analysis, to assess the reproducibility of systematic tissue sampling in the angiogenic hot spot selection, and quantification of microvessel density (MVD) and other vessel characteristics. The latter data were compared between six metastasised tongue squamous cell carcinomas, vs. four non-metastasised. In comparison to the standard immunohistochemical protocol with anti-CD34 antibodies, CARD amplification resulted in both more intensely stained and larger numbers of vessels. Averaging the 10 most vascularised fields of the 40 to 60 systematically sampled fields in a tissue section resulted in an overall acceptable interobserver reproducibility for most assessed vessel parameters (r≧ 0.76 andp≦ 0.01). The percentage vessels with diameter <5 μm was significantly higher in the non-metastasised tongue carcinomas (p= 0.02). However, for a number of tumours the effect of tissue sampling was significant. We conclude that CARD amplification is needed for reliable segmentation of vessels by image analysis systems, and that tumour heterogeneity is a limiting factor for all procedures in which tumour vascularity is assessed in a single tissue section.
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Nagahara, Kunihiko, Youichi Miyake, Takushi Aoyama, and Fumimaru Ogino. "Tissue Oxygen Tension in the Stria Vascularis." Acta Oto-Laryngologica 105, sup456 (January 1988): 137–42. http://dx.doi.org/10.3109/00016488809125091.
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PARKASH, S. "Simulated Testis Using Vascularised Autogenous Tissue." British Journal of Urology 59, no. 1 (January 1987): 97–98. http://dx.doi.org/10.1111/j.1464-410x.1987.tb04597.x.
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Morelon, Emmanuel, Jean Kanitakis, Olivier Thaunat, Palmina Petruzzo, and Lionel Badet. "Aspects immunologiques des greffes de tissus composites vascularisés." Soins 64, no. 839 (October 2019): 20–21. http://dx.doi.org/10.1016/j.soin.2019.09.006.
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Butterworth, Mark, and Peter E. M. Butler. "FLAP VASCULARITY AFTER FREE MUSCULOCUTANEOUS TISSUE TRANSFER." Plastic and Reconstructive Surgery 107, no. 3 (March 2001): 894–95. http://dx.doi.org/10.1097/00006534-200103000-00054.
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Machens, Hans-Günther. "FLAP VASCULARITY AFTER FREE MUSCULOCUTANEOUS TISSUE TRANSFER." Plastic and Reconstructive Surgery 107, no. 3 (March 2001): 895. http://dx.doi.org/10.1097/00006534-200103000-00055.
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Nettelblad, H., and E. Tarpila. "Abdominal Wall Reconstruction with Vascularised Autologous Tissue." Scandinavian Journal of Surgery 92, no. 4 (December 2003): 297–300. http://dx.doi.org/10.1177/145749690309200410.
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Williams, G., P. Butler, and N. Niranjan. "FLAP VASCULARITY AFTER FREE MUSCULOCUTANEOUS TISSUE TRANSFER." Plastic & Reconstructive Surgery 102, no. 5 (October 1998): 1781. http://dx.doi.org/10.1097/00006534-199810000-00104.
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Machens, H. G., N. Pallua, J. Pasel, P. Mailaender, J. Liebau, and A. Berger. "FLAP VASCULARITY AFTER FREE MUSCULOCUTANEOUS TISSUE TRANSFER." Plastic & Reconstructive Surgery 102, no. 5 (October 1998): 1782. http://dx.doi.org/10.1097/00006534-199810000-00105.
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Morritt, A. N., R. J. Dilley, J. Rickards, X. L. Han, D. McCombe, W. A. Morrison, and S. K. Bortolotto. "Tissue Engineering of Spontaneously Beating, Vascularised, Three-Dimensional Cardiac Tissue." Journal of Molecular and Cellular Cardiology 41, no. 4 (October 2006): 742. http://dx.doi.org/10.1016/j.yjmcc.2006.06.040.
Повний текст джерелаДисертації з теми "Tissu vascularisé"
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Devillard, Chloé. "Développement de tissus vasculaires par bioimpression 3D." Thesis, Lyon, 2021. http://www.theses.fr/2021LYSE1339.
Повний текст джерелаАнотація:
Cette thèse a pour objectif de développer un tissu vasculaire par la méthode de bio-impression 3D de tissus vivants. Pour mener à bien ces travaux, une bioencre composée de trois biomatériaux naturels : la gélatine, l’alginate et le fibrinogène, a été formulée. Une amélioration du processus de fabrication d’un objet 3D par bio-impression ainsi que le développement d’une solution de consolidation spécifique, a permis le développement d’un réseau cellulaire en trois dimensions. L’utilisation particulière de milieu de culture à toutes les étapes de fabrication, de la préparation des biomatériaux à la consolidation de l’objet, a démontré une augmentation de la prolifération cellulaire de manière conséquente. Des caractérisations rhéologiques et histologiques ont été mises en place afin de démontrer cette prolifération augmentée. Afin de développer un tissu vasculaire, plusieurs approches technologiques ont été présentées, suivant un cahier des charges bien définit : (i) la technologie de biofabrication vasculaire tubulaire et (ii) la technologie de biofabrication vasculaire plane. Les méthodes de bio-impression 3D par micro-extrusion à 1 et 3 extrudeurs, la bio-impression 3D co-axial et tri-axial, la bio-impression 3D en milieu contraint, l’impression 4D par diffusion enzymatique, la bio-impression 3D par enroulement, ont ainsi été étudiées pour répondre à la création d’une structure tubulaire, multicouche et de taille centimétrique. La bio-impression 3D par micro-extrusion et la bio-impression 4D ont, quant à elles, été présentées pour répondre à la création d’une structure multicouche plane, biologiquement pertinente, mimant la paroi vasculaire composée d’une couche endothéliale, d’une couche de cellules musculaires lisses vasculaires et d’une couche de fibroblastes. La dernière partie de ce travail de thèse concerne les résultats de bio-impression, permettant de biofabriquer un tissu vascularisé. Une étude de l’impact des communications entre les fibroblastes et les cellules endothéliales, à l’intérieur d’un environnement 3D, sur le développement d’un réseau complexe, a été présentée. Un tissu vascularisé organisé par les cellules endothéliales à l’intérieur d’une matrice extracellulaire dense et néosynthétisée par les fibroblastes, a ainsi pu être mise en place en 7 jours. Des caractérisations histologiques ont mis en évidence la présence d’une micro-vascularisation et la technologie de microscopie électronique à transmission a permis de caractériser la formation de fibres de collagène et d’élastine, sécrétées par les fibroblastesThis thesis aims to develop a vascular tissue by the method of 3D bioprinting of living tissue. To carry out this work, a bioink composed of three natural biomaterials: gelatin, alginate, and fibrinogen, was formulated. An improvement in the manufacturing process of a 3D object by bioprinting as well as the development of a specific consolidation solution allowed the development of a three-dimensional cellular network. The particular use of culture medium at all stages of manufacture, from the preparation of the biomaterials to the consolidation of the object, has demonstrated a marked increase in cell proliferation. Rheological and histological characterizations were set up to demonstrate this increased proliferation. To develop vascular tissue, several technological approaches have been presented, following well-defined specifications: (i) tubular vascular biofabrication technology and (ii) planar vascular biofabrication technology. The methods of 3D bioprinting by micro-extrusion with 1 and 3 extruders, co-axial and tri-axial 3D bioprinting, 3D bioprinting in a constrained environment, 4D printing by enzymatic diffusion, bio- 3D printing by winding, have thus been studied to respond to the creation of a tubular, multilayer structure of centimeter size. Micro-extrusion 3D bioprinting and 4D bioprinting were presented to respond to the creation of a planar multilayer structure, biologically relevant, mimicking the vascular wall composed of an endothelial layer, d 'a layer of vascular smooth muscle cells, and a layer of fibroblasts. The last part of this thesis concerns the results of bioprinting, allowing to biofabricate a vascularized tissue. A study of the impact of communications between fibroblasts and endothelial cells, within a 3D environment, on the development of a complex network, was presented. A vascularized tissue organized by endothelial cells inside a dense extracellular matrix and neosynthesized by fibroblasts could thus be placed in 7 days. Histological characterizations demonstrated the presence of micro-vascularization and transmission electron microscopy technology characterized the formation of collagen and elastin fibers, secreted by fibroblasts
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Vijayasekaran, Aparna. "Human Adipose Derived Stem Cells (hASC's) and Soft Tissue Reconstruction: Evaluation of Methods for Increasing the Vascularity of Tissue Engineered Soft Tissue Construct." Thesis, The University of Arizona, 2012. http://hdl.handle.net/10150/265352.
Повний текст джерелаАнотація:
Generation of large volumes to cover an existing soft tissue defect is often complicated by the lack of available tissue. The current options for soft tissue reconstruction include local and free flaps, collagen fillers, traditional fat grafting and other synthetic soft tissue fillers. But they all have limitations. Recently, a lot of interest has been generated regarding the use of human adipose derived stem cells for engineering a biocompatible soft tissue construct. Give their ready availability, viability and plasticity they appear to be the ideal building blocks for a cell based soft tissue construct. We find that these cells are easy to isolate in large numbers, easy to maintain in culture and capable of multi-lineage differentiation. hASC's are readily adherent to collagen based scaffolds and these function as the ideal cell delivery matrix. Since most wound beds are ischemic and hypoxic, changes in gene expression of hASC's was studied in conditions of hypoxia and serum deprivation. Microarray PCR results demonstrate the up regulation of 23 angiogenic genes including VEGFC, ANPEP, CXCL6, ANGPLT4 and CXCL5 in conditions of hypoxia. However, this angiogenic response was blunted with the presence of serum starvation in addition to hypoxia. Hence we chose to investigate methods to increase the primary neovascularization of a tissue engineered construct. Our hypothesis was that Europium Nano rods (belonging to the lanthanide series of heavy metals) would increase the angiogenic potential of hASC's. Results of a chick embryo chorioallantoic membrane assay demonstrate that Europium Nano rods potentiate the angiogenic effects of Vascular Endothelial Growth Factor (VEGF) when incorporated in hASC's. These rods are readily incorporated in hASC's by endocytosis and do not affect viability. Hence, we conclude that Europium Nano rods can function as a reliable, nontoxic extrinsic angiogenic stimulus. Further studies are needed to evaluate the 1) effects of ENR's on stem cell plasticity 2) effects on gene expression and 3) further investigate the fate of ENR's with repeated cell division.
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Pimenta, Felipe Araújo. "Desenvolvimento de arcabouços para a engenharia tecidual de enxertos vasculares." reponame:Repositório Institucional da UFABC, 2017.
Знайти повний текст джерелаАнотація:
Orientadora: Profa Dra Sônia Maria MalmongeDissertação (mestrado) - Universidade Federal do ABC. Programa de Pós-Graduação em Engenharia Biomédica, 2017.
Os enxertos vasculares sao comumente usados em procedimentos de revascularizacao, porem existe recorrencia de falhas dos enxertos sinteticos quando usados em areas de baixo fluxo e/ou pressao sanguinea, bem como dificuldade quanto a disponibilidade e disparidade de tamanhos em substituintes autogenos. O objetivo desse trabalho foi o desenvolvimento de arcaboucos para engenharia tecidual de enxertos vasculares de pequeno calibre. O trabalho foi divido em etapas: etapa 1 . para selecionar o(s) polimero(s) mais adequado(s) e tecnica de fabricacao dos arcaboucos; etapa 2 e 3 . para definir as melhores condicoes de processamento; etapa 4 . para a producao dos arcaboucos tubulares (enxertos vasculares), determinar a porosidade aparente, bem como estimar valores de complacencia e pressao de ruptura. A caracterizacao das amostras obtidas nas diferentes etapas foi realizada atraves de imagens de microscopia optica (MO), eletromicrografias de microscopica eletronica (MEV) de varredura com quantificacao de diametro de fibras, ensaios tensao x deformacao sob tracao, e de simulacao computacional dinamica dos fluidos. Foi definido como meta para os arcaboucos a obtencao de estruturas de nanofibras homogeneas livres de contas e valores de propriedades mecanicas proximas aos apresentados pelos vasos naturais. Na Etapa 1, foram selecionados o poli(¿Ã-caprolactona) (PCL) como materia prima e a tecnica de airbrushing como metodo de fabricacao de estruturas fibrosas; na Etapa 2, a pressao de trabalho de 40 PSI foi definida por ser o parametro que resultou em formacao de fibras livres de contas; na etapa 3, o alinhamento de fibras e distancia de 25 cm com coletor rotativo foi definido por resultarem em propriedades mais proximas as dos vasos naturais; e na etapa 4 a condicao de 750 rpm do coletor rotativo, por resultar em arcaboucos com propriedades satisfatorias (complacencia de 12,47 } 2,78 %/100 mmHg; pressao de ruptura de 3483,9 } 358,5 mmHg, e porosidade de 91,07 } 2,69 %). Foi possivel a obtencao de mantas de fibras com diametros em torno de 200 nm tanto para fibras alinhadas quanto nao-alinhadas, com dimensoes na faixa de dimensoes das proteinas estruturais (50 a 500 nm), bem como a obtencao de arcaboucos tubulares promissores para serem usados como enxertos vasculares de pequeno calibre, o que abre perspectiva para a continuacao do estudo.
Vascular grafts are commonly used in revascularization procedures, but there are recurrences when synthetic grafts are used in areas of low blood flow and/or blood pressure, difficulty in the availability as well as disparity of sizes in case of autogenous substituents. The objective of this work was the development of scaffolds for tissue engineering of small caliber vascular grafts. The work was divided in steps: step 1 . to select the most suitable polymer (s) and technique to manufacture the scaffolds; step 2 and 3 . to define the best processing conditions; step 4 . for the production of tubular scaffolds (vascular grafts), to determine the apparent porosity, as well as to estimate values of compliance and burst pressure. The characterization of the obtained samples in the different stages was performed through optical microscopy (OM) images, scanning electron microscopy (SEM) images with fiber diameter quantification, tensile stress x strain tests, and dynamic computational fluid simulation. The goal of the scaffolds was to obtain homogeneous bead-free nanofibrous structures and values of mechanical properties similar to those presented by natural vessels. In Step 1, the poly(¿Ã-caprolactone) (PCL) was selected as the raw material and the airbrushing technique was chosen as a method of manufacturing fibrous structures; in Step 2, the working pressure of 40 PSI was defined as the parameter that resulted in the less beads formation; in step 3, fiber alignment and rotating collectorLs distance of 25 cm was chosen, since resulted in properties closer to those of natural vessels; and in step 4 the 750 rpm rotating collector condition resulted in satisfactory properties (compliance of 12,47 } 2,78 % /100 mmHg, burst pressure of 3483,9 } 358,5 mmHg, and porosity of 91,07 } 2,69 %). It was possible to obtain nanofibers with diameters around 200 nm for both aligned and non-aligned fibers, with dimensions in the range of structural proteins (50 to 500 nm), as well as obtaining tubular scaffolds to be used as small-caliber vascular grafts, which opens the prospect for further study.
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Makhene, Lebohang. "The development of biodegradable aerogel scaffolds for the generation of vascularised 3D adipose tissue models." Thesis, Rhodes University, 2017. http://hdl.handle.net/10962/59245.
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Mauroux, Adèle. "Développement d’un substitut cutané vascularisé au derme compartimenté : impact des microenvironnements papillaires et réticulaires." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS532.
Повний текст джерелаАнотація:
Le derme se divise entre les dermes papillaires et réticulaires qui présentent des matrices extracellulaires (MEC) et une vascularisation distincte. Les fibroblastes de chaque compartiment jouent des rôles différents dans la physiologie cutanée. Cependant, peu d’informations est disponible sur leurs propriétés angiogéniques et aucun modèle ne reproduit ces compartiments. L’objectif de ce travail a été de développer un substitut cutané vascularisé qui reproduise les microenvironnements papillaires et réticulaires. Nous avons d’abord mis au point un substitut cutané vascularisé à partir d’une population mixte de fibroblastes par superposition de feuillets cellulaires. Cette technique repose sur la capacité des cellules à déposer leur propre MEC et reproduit une MEC plus physiologique. Nous avons également montré que des molécules angiogéniques peuvent remodeler le réseau vasculaire des substituts. Nous avons ensuite étudié les feuillets cellulaires générés à partir de fibroblastes papillaires et réticulaires et caractérisé leur matrisome et leur profil angiogénique. Ces différences d’expression de gènes se traduisent par la génération de MEC distinctes et des sécrétomes spécifiques. Le microenvironnement de chaque population de fibroblastes induit la formation d’un réseau vasculaire qui présente des points communs avec la peau native. L’ensemble de ces résultats démontrent que les fibroblastes papillaires et réticulaires régulent l’angiogenèse dans la peau via des facteurs paracrines et microenvironnementaux et que les feuillets générés à partir de ces fibroblastes permettent de reproduire certaines caractéristiques des compartiments dermiques observés in vivoThe dermis is divided between the papillary and reticular dermis that display distinct extracellular matrix (ECM) and vascularization. Fibroblasts isolated from each compartment play different role in skin physiology. However, little information is available regarding their role in angiogenesis regulation and no substitute allows to study dermal compartments. The aim of this work was thus to develop a vascularized skin substitute that reproduces papillary and reticular microenvironments.We first developed a vascularized skin substitute using a mixed population of fibroblasts by cell sheet layering. This technique relies on the ability of cells to generate their own ECM and reproduces a more physiological ECM. Furthermore, angiogenic molecules could remodel the vascular network of this skin substitute, indicating that this model is appropriate to study complex interaction between microenvironment and vascularization. We then studied cell sheets generated by papillary and reticular fibroblasts and characterized their matrisome and angiogenic gene expression signature. These difference in gene expression resulted in the generation of specific ECM and secretome. The microenvironment generated by each population of fibroblasts differentially regulated angiogenesis and reproduced some features of native skin in vivo. Overall, these results demonstrate that papillary and reticular fibroblasts contribute to skin angiogenesis via distinct paracrine factors and microenvironments and that vascularized cell sheets reproduce some features of native dermal compartments
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Sandlund, Johanna. "Angiogenesis in human renal cell carcinoma : hypoxia, vascularity and prognosis." Doctoral thesis, Umeå : Univ, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1331.
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Pourchet, Léa. "Développement d’une bio-encre pour la bioimpression 3D de tissus vivants : étude de la formulation et caractérisation du développement tissulaire." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1232/document.
Повний текст джерелаАнотація:
Cette thèse a pour objectif de développer une méthode de bioimpression 3D de tissus vivants. Ce nouveau champ disciplinaire a pour but la fabrication de tissus grâce à une bioimprimante en s’appuyant sur les principes fondamentaux de l’ingénierie tissulaire. Pour mener à bien ces travaux, une bio-encre spécifique a été formulée à l’aide de biomatériaux naturels afin de répondre aux critères de biocompatibilité, de maintien de la viabilité cellulaire et de support pour la formation d’un réseau cellulaire en trois dimensions. Plusieurs caractérisations ont ainsi pu être réalisées afin de démontrer l’innocuité du procédé de bioimpression 3D sur les cellules utilisées.L’évolution technologique de la bioimprimante utilisée est ensuite présentée en partant d’une technologie open-source pour arriver à l’utilisation d’un bras robotique 6 axes. L’exigence du cahier des charges de cette bioimprimante a évolué au fil des différents prototypes utilisés.La dernière partie de ce travail de thèse présente les résultats de bioimpression de tissus obtenus grâce à de multiples collaborations. Plusieurs tissus seront étudiés et caractérisés : le derme et sa maturation vers une peau totale, le cartilage et la bioimpression de cellules souches mésenchymateuses, un tissu microvascularisé grâce à l’incorporation de cellules endothéliales et pour finir un tissu perfusable en utilisant une approche de culture dynamique en bioréacteurThis thesis focus on the development of a 3D bioprinting process for living tissue. This new field of research, 3D bioprinting, aims to fabricate tissues using a bioprinter based on the tissue engineering fundamentals.To carry out this work, a specific bioink was formulated using natural biomaterials to meet the requirement of biocompatibility, cell viability and support of a three-dimensional cellular network. Several characterizations have been used to demonstrate the cells viability during the 3D bioprinting process.The bioprinter technological evolution is then presented, starting from an open-source technology and ending with the use of a 6-axis robotic arm. The specifications of this bioprinter evolved through different prototypes.The last part of this thesis concerns tissue bioprinting results obtained through multiple collaborations. Several tissues will be studied and characterized: the dermis and its maturation towards a total skin, the cartilage and the mesenchymal stem cells bioprinting, a microvascularized tissue thanks to the incorporation of endothelial cells and finally a perfusable tissue by using a dynamic culture approach in bioreactor
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Simplicio, Janaina Aparecida. "Participação do TNF-a nas disfunções vasculares induzidas pelo consumo crônico de etanol: envolvimento do tecido adiposo perivascular." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/17/17133/tde-17042018-160849/.
Повний текст джерелаАнотація:
O consumo crônico de etanol é um importante fator de risco no desenvolvimento de doenças cardiovasculares induzindo elevação da pressão arterial, inflamação, disfunção vascular e aumento do estresse oxidativo em vários tecidos. Além disso, o consumo crônico de etanol induz aumento dos níveis de Fator de necrose tumoral-? (TNF-?). O tecido adiposo perivascular (Perivascular adipose tissue - PVAT) é reconhecido como uma importante fonte de adipocinas e citocinas pró-inflamatórias e esse tecido está envolvido na fisiopatologia de diferentes doenças cardiovasculares. A hipótese deste trabalho é a de que o consumo crônico de etanol estimule a produção de TNF-? no tecido vascular, que por sua vez, induzirá um aumento na produção de espécies reativas de oxigênio (ERO), redução da biodisponibilidade do óxido nítrico (NO), inflamação vascular, prejuízo na função do PVAT, alteração da reatividade vascular e aumento da pressão arterial. Portanto, o objetivo deste estudo foi investigar a participação do TNF-? nas disfunções vasculares induzidas pelo consumo de etanol e avaliar o papel do PVAT em tais danos. O trabalho mostra que o consumo crônico de etanol por 12 semanas induziu aumento da pressão arterial sistólica (PAS) em camundongos machos C57BL/6 (Wild Type -WT) e este aumento foi menor nos animais nocautes para os receptores R1 do TNF-? (TNFR1-/-). O tratamento com etanol não alterou o relaxamento vascular induzido por acetilcolina e nitroprussiato de sódio (NPS). O consumo de etanol induziu aumento da geração de ânion superóxido (O2-), aumento das espécies reativas ao ácido tiobarbitúrico (TBARS) e redução dos níveis de peróxido de hidrogênio (H2O2) em aortas com e sem PVAT (PVAT+ e PVAT-, respectivamente) de animais WT, mas não em camundongos TNFR1-/-. Houve aumento da atividade da catalase (CAT) e da superóxido dismutase (SOD) em aorta PVAT- e PVAT+ e redução dos níveis plasmáticos da glutationa reduzida (GSH) em animais WT, mas não em TNFR1-/-, após o consumo crônico de etanol. Não houve alteração na atividade da glutationa peroxidase (GPx) na aorta dos grupos estudados após o consumo de etanol. Observou-se redução dos níveis de nitrato/nitrito (NOx) em aortas de animais WT após o consumo de etanol, porém não em camundongos TNFR1-/-. O consumo de etanol gerou aumento tecidual das citocinas TNF-? e IL-6 e aumento da atividade da mieloperoxidase (MPO), evidenciando uma exacerbada inflamação vascular e indicando migração de neutrófilos para o tecido aórtico. Tais alterações não foram observadas em animais TNFR1-/-. Os resultados mostram pela primeira vez a participação do TNF-? no aumento da pressão arterial, no aumento do estresse oxidativo e nos prejuízos vasculares induzidos pelo consumo crônico de etanol. O tecido adiposo perivascular não apresentou qualquer efeito benéfico nas alterações supracitadas.Chronic ethanol consumption is an important risk factor in the development of cardiovascular diseases, inducing increased blood pressure, inflammation, vascular dysfunction and enhanced oxidative stress in several tissues. Furthermore, chronic ethanol consumption induces the production of Tumor necrosis factor-? (TNF-?). Perivascular adipose tissue (PVAT) is known as an important source of adipokines and proinflammatory cytokines. This tissue is involved in the pathophysiology of different cardiovascular diseases. The hypothesis of this work is that the chronic ethanol consumption stimulates the production of TNF-?, which in turn, will induce an increase in reactive oxygen species (ROS) generation, nitric oxide (NO) reduction, vascular inflammation, impairment of PVAT function, alterations of vascular reactivity and increased blood pressure. Therefore, the aim of this study was to investigate the role of TNF-? in chronic ethanol consumption-induced vascular dysfunctions and to evaluate the role of PVAT in such damages. This study demonstrated that chronic ethanol consumption for 12 weeks induced an increase in systolic blood pressure (SBP) in C57BL/6 mice (wild type-WT) and this increase was blunted in TNF-? receptor 1 knockout mice (TNFR1-/-). There was no change in vascular relaxation induced by acetylcholine and sodium nitroprusside (NPS). Ethanol consumption increased the superoxide anion (O2-) generation, thiobarbituric acid reactive species (TBARS) and reduction of hydrogen peroxide (H2O2) levels in aorta without and with PVAT (PVAT- and PVAT+, respectively) from WT animals, but not from TNFR1-/- mice. There was an increase in catalase (CAT) and superoxide dismutase (SOD) activities in aorta PVAT- and PVAT+, decrease on plasma reduced-glutathione (GSH) levels from ethanol-treated WT but not in TNFR1-/-. Ethanol consumption did not change glutathione peroxidase (GPx) activity in any group. Nitrate/nitrite (NOx) aortic levels were decreased in WT animals, but not in TNFR1-/- after chronic ethanol consumption. Ethanol consumption increased TNF-?, IL-6 cytokines and myeloperoxidase activity (MPO) which suggest a strong vascular inflammation and migration of neutrophils into the aortic tissue. Such changes were not observed in TNFR1-/- mice. The results show for the first time the participation of TNF-? in the increase of blood pressure, increase of oxidative stress and vascular dysfunction induced by the chronic ethanol consumption. The perivascular adipose tissue had no beneficial effect on these changes.
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Costa, Rafael Menezes da. "Disfunção mitocondrial no tecido adiposo perivascular e seu papel nas alterações vasculares em modelo experimental de obesidade." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/17/17133/tde-20072016-144840/.
Повний текст джерелаАнотація:
A obesidade desencadeia mudanças estruturais e funcionais no tecido adiposo perivascular (PVAT), levando a um desequilíbrio em favor de substâncias vasoconstritoras e pró- inflamatórias, bem como alterações em suas vias de sinalização no vaso. Um importante mecanismo proposto para explicar a perda do efeito anticontrátil do PVAT na obesidade é o estresse oxidativo. Espécies reativas de oxigênio (EROs) possuem papel importante na modulação da função vascular mediada pelo PVAT. Considerando que a mitocôndria representa fonte potencial de EROs nas células, o presente estudo testou a hipótese que a disfunção mitocondrial no PVAT está envolvida na perda do efeito anticontrátil do PVAT em modelo experimental de obesidade. Este estudo avaliou se a matriz mitocondrial nas células que compõem o tecido adiposo periaórtico representa fonte importante de EROs, e se as mesmas contribuem para as alterações na regulação, pelo PVAT, da reatividade vascular. Nosso estudo demonstrou que animais obesos apresentaram disfunção vascular e perda do efeito anticontrátil do PVAT. O estresse oxidativo está envolvido na disfunção do PVAT, com participação significativa da mitocôndria na geração de EROs, capazes de modular a reatividade vascular. A obesidade favoreceu a disfunção mitocondrial, reduzindo o consumo de oxigênio. Estes eventos favoreceram o aumento na geração de peróxido de hidrogênio mitocondrial no PVAT, o qual prejudica a ação anticontrátil deste tecido por ser ativador direto da via de contração RhoA/Rho cinaseObesity promotes structural and functional changes in the perivascular adipose tissue (PVAT), favoring the release of vasoconstrictor and proinflammatory substances, as well as altering the vascular signaling pathways activated by PVAT-derived factors. Oxidative stress is an important mechanism proposed to explain the loss of anticontractile effects of the PVAT in obesity. Reactive oxygen species (ROS) play an important role in the modulatory effects of PVAT on vascular function. Considering that mitochondria are a potential source of ROS in the cells, the present study tested the hypothesis that mitochondrial dysfunction leads to the loss of the anticontractile effects of PVAT in obesity. We evaluated whether the mitochondrial matrix of the cells that make up the periaortic fat tissue constitute a major source of ROS, and if mROS contribute to defective regulation of vascular reactivity by the PVAT. Our study shows that obese animals exhibit vascular dysfunction and loss of anticontractile effects of PVAT. Oxidative stress is involved in PVAT dysfunction, with a significant contribution of mitochondria to ROS generation. Obesity promotes mitochondrial dysfunction, reducing oxygen consumption. These events increase the generation of mitochondrial hydrogen peroxide in the PVAT, which impairs the anticontractile effects of this tissue via direct activation of the RhoA / Rho kinase pathway
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Muller, Quentin Philippe Sylvain. "Développement par génie tissulaire d’un modèle de peau humaine innervée, vascularisée et immunocompétente pour l’étude des réactions inflammatoires cutanées." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAJ061.
Повний текст джерелаАнотація:
Les réactions immunitaires de la peau sont initiées par les cellules dendritiques cutanées (dendritic cells, DCs). L'effet potentiellement sensibilisateur d'un composé peut être prédit in vitro en utilisant des monocytes humains différenciés en DCs (MonoDCs). Cependant, ces modèles simplistes restent imprécis car l'activation des DCs cutanés par les sensibilisateurs peut être déclenchée ou modulée par des interactions microenvironnementales avec de multiples types de cellules non immunitaires. Notre objectif est de développer une peau immunocompétente qui combinera des MonoDCs avec tous les éléments structurels et fonctionnels de la peau, c'est-à-dire une barrière épidermique posée sur un derme contenant une pseudo-vascularisation et des neurones nociceptifs. Une matrice de collagène a été ensemencée avec des fibroblastes et des cellules endothéliales, puis avec des précurseurs de fibres nerveuses dérivées soit de l'iPSC humaine, soit de la DRG embryonnaire murins. Enfin, nous avons introduit les MonoDC et les kératinocytes. Nous avons observé que les neurones différenciés in situ innervent l'épiderme comme observé habituellement dans la peau humaine normale. De plus, les neurones dérivées d’iPSCs, expriment neuropeptides et canaux calcique spécifiques des fibres nociceptives. Enfin, les Mono-DC intégrés au modèle restent stable pendant toute la durée nécessaire à la formation de l’épiderme et peuvent être stimulé. Le modèle sera utilisé pour prédire le potentiel irritant des composés chimiques et l'impact de l’innervation nociceptive sur l'activation des DCsImmune reactions in the skin are initiated by the cutaneous dendritic cells (DCs). The potential sensitizing effect of a compound can be predicted in vitro using human monocytes differentiated into DCs (Mono-DCs). However, these simplistic models remain inaccurate because the activation of cutaneous DCs by sensitizers may be triggered or modulated by microenvironmental interactions with multiple types of non-immune cells. Our goal is to develop an immunocompetent human tissue-engineered skin that will combine DCs with all structural and functional element of the skin, i.e. an epidermal barrier laid upon a dermis containing a pseudo-vascularization and nociceptive neurons. Collagen matrix was seeded with fibroblasts and endothelial cells, then with precursors of nerve fibers derived from either human iPSC or murine embryonic DRG. Finally, we introduced Mono-DCs and keratinocytes. We observed that in situ differentiated neurons grow axons towards the epidermis as usually observed in normal human skin. What's more, the neurons derive from iPSC, express neuropeptides and calcium channel as normal nociceptive fibers. Moreover, Mono-DCs settled as expected beneath the epidermis and remained sessile to stimulation for several weeks. The model will be used to predict the irritant potential of chemical compounds, and the impact of nerves on DC activation
Книги з теми "Tissu vascularisé"
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McGuigan, Alison P. Design and fabrication of a modular vascularised tissue-engineered construct. 2005.
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Calder, Peter. Chronic long bone osteomyelitis. Oxford University Press, 2011. http://dx.doi.org/10.1093/med/9780199550647.003.011001.
Повний текст джерелаАнотація:
Pathological features of chronic osteomyelitis♦ Necrotic bone♦ Compromised soft tissues with reduction in vascularity♦ Ineffective host response♦ Sequestrum formation♦ New bone formation from viable periosteum and endosteum♦ Formation of involucrum:Treatment principles in chronic osteomyelitis♦ Surgical debridement – remove all devitalized necrotic tissue♦ Dead space management:• Soft tissue defect – avoid healing by secondary intention. Consider local and free flaps• Bone defects – small structural with autologous bone graft, consider Papineau ‘open bone grafting’ where free tissue transfer is not an option, distraction osteogenesis with bifocal and bone transport for large defects including fibula transfer♦ Bone stability – movement needs to be eliminated♦ Antibiotic therapy – based on culture and sensitivity, local administration with PMMA beads or collagen sponge, Lautenbach procedure in resistant cases.
Частини книг з теми "Tissu vascularisé"
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Moortgat, Peter, Mieke Anthonissen, Ulrike Van Daele, Jill Meirte, Tine Vanhullebusch, and Koen Maertens. "Shock Wave Therapy for Wound Healing and Scar Treatment." In Textbook on Scar Management, 485–90. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-44766-3_55.
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AbstractShock Wave Therapy (SWT) meets all the requirements for the ideal non-invasive scar treatment. It is safe, well tolerated by patients, cost-effective, easy to apply, has low complication rates, and can be used in an outpatient setting. The overall effect of SWT is an improvement of tissue homeostasis, accompanied by an improvement of the tissue self-healing abilities, and it seems to focus on inducing tissue regeneration and matrix remodeling in vivo by means of mechanotransduction.SWT has a beneficial effect on wound healing and is characterized by an upregulation of the angio-active factors as nitric oxide (NO) and vascular endothelial growth factor (VEGF) leading to induced angiogenesis. A downregulation of alpha-SMA expression, myofibroblast phenotype, TGF-β1 expression, fibronectin, and collagen type I are measured after SWT on scars, leading to improvement of several relevant scar parameters like height, pliability, vascularity, and pigmentation, and thus ameliorating function.For a full treatment outline, the energy flux density (EFD), the number of pulses, the pulse frequency, and the number and interval of treatments are the most relevant parameters. The EFD for soft tissue indications is typically in the range of 0.08–0.25 mJ/mm2, while scars and fibrosis are treated with an EFD ranging between 0.15 and 0.33 mJ/mm2. These settings seem to be ideal to induce the optimal cell responses for each indication.All the presented findings are fundamental knowledge for further investigation of SWT to reduce the fibrous component in regenerating and remodeling tissues. However, the full potential of SWT in wound healing and scar treatment needs further unraveling.
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Nischwitz, Sebastian P., David B. Lumenta, Stephan Spendel, and Lars-Peter Kamolz. "Minimally Invasive Technologies for Treatment of HTS and Keloids: Pulsed-Dye Laser." In Textbook on Scar Management, 263–69. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-44766-3_31.
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AbstractWe present another minimally invasive technology for the treatment of hypertrophic scars and keloids: the pulsed-dye laser. Being first introduced by two groups around Schaefer (Germany) and Sorokin & Lankard (USA) in 1966, the pulsed dye laser is a rather new technology. The first clinical use of pulsed-dye lasers was reported in 1983 for the treatment of naevus flammeus, and was the first laser used for the treatment of keloids in the mid-1990s.Its efficacy is based on the principle of selective photothermolysis, enabling a selective destruction of defined structures absorbing the respective wavelength used, as compared to other lasers working based on thermal coagulation or ablative tissue interaction. The preferred wavelengths being used are 585 or 595 nm, which makes small cutaneous vessels the main targets. Their destruction leads to a diminished blood supply of the irradiated area, thus reducing symptoms of hypertrophic scars like itching, vascularity, and redness, and secondary – probably by the induced hypoxemia – a reduction in scar height and pliability. This therapeutic approach also implies the use of pulsed-dye laser in the prevention of pathologic scars. While significant side effects are usually rare, slight signs of use like edema or scab formation can pertain for several days. Since the sensory impact of laser pulses are comparable to needle pricks, some form of analgesia during the application is highly recommended. The elusive data and still existing scarcity of high-quality studies on the use of pulsed-dye laser, however, make it hard to develop clear recommendations.
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A., Remo, Venkat M., Martin Ehrbar, Algirdas Ziogas, Jan A., and Daniel Eberli. "Angiogenesis and Vascularity for Tissue Engineering Applications." In Regenerative Medicine and Tissue Engineering - Cells and Biomaterials. InTech, 2011. http://dx.doi.org/10.5772/25141.
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"Plastic surgery." In Oxford Handbook of Clinical Surgery, edited by Greg McLatchie, Neil Borley, Anil Agarwal, Santhini Jeyarajah, Rhiannon Harris, and Ruwan Weerakkody, 699–744. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780198799481.003.0017.
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This chapter evaluates plastic surgery, which is a constantly evolving surgical discipline based upon technical exactitude, detailed anatomical knowledge, and innovation. Plastic surgeons have strong aesthetic awareness, but the true scope of their practice is very much broader. The ethos of this work is to restore form and function. In pursuit of this goal, techniques have been refined that enable the transfer of tissues around the body as non-vascularised ‘grafts’, or vascularised ‘flaps’ that may be ‘pedicled’ on their anatomical blood supply, or revascularised after autologous transplantation by microvascular anastomosis. Globally, plastic surgeons collaborate with many specialties to enable oncological treatments and manage congenital abnormalities and trauma and severe soft tissue infections (SSTIs) across a broad range of conditions. In addition to this work, plastic surgeons have been involved in the development of composite tissue allotransplantation techniques that include facial, abdominal wall, and hand transplantation. The chapter then highlights some of the common reasons for referral to plastic surgery and describes some of the common plastic surgery techniques available to address these.
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"Soft Tissue Reconstruction." In Standards for the Management of Open Fractures, edited by Simon Eccles, Bob Handley, Umraz Khan, Iain McFadyen, Jagdeep Nanchahal, and Selvadurai Nayagam, 63–74. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198849360.003.0008.
Повний текст джерелаАнотація:
Soft tissue coverage of open fractures with well-vascularised tissues should be performed within 72 hours of injury or at the same time as internal fixation. It may be in the form of local or free flaps, and may comprise muscle, fasciocutaneous tissues, or both. Flap selection depends on multiple factors, including the size and location of the defect following wound excision, availability of flaps, and donor site morbidity. Local flaps are usually used to cover defects with a limited zone of injury. Anastomoses for free flaps should be performed outside the zone of injury. Experimental data suggest that coverage with muscle leads to improved healing of fractures. However, there is currently little clinical evidence to support the use of one form of soft tissue cover over another for open fractures of the lower limb. The plastic surgeon must always consider the donor site morbidity of the flap(s) chosen.
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Spickett, Gavin. "Autoimmune eye disease." In Oxford Handbook of Clinical Immunology and Allergy, edited by Gavin Spickett, 273–80. Oxford University Press, 2019. http://dx.doi.org/10.1093/med/9780198789529.003.0011.
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The eye has a number of interesting immunological properties that alter the propensity for immune-mediated disease, including the curious feature that antigen injected into the anterior chamber induces tolerance rather than immunity. In addition, the eye has no true lymphatics, relatively poor vascularity, and, as the retina is an extension of the CNS, there is a blood–retinal barrier that limits passage of molecules in either direction. Ocular involvement is a common feature of many connective tissue and vasculitic diseases.
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"Prehospital and Emergency Department Care, Including Prophylactic Antibiotics." In Standards for the Management of Open Fractures, edited by Simon Eccles, Bob Handley, Umraz Khan, Iain McFadyen, Jagdeep Nanchahal, and Selvadurai Nayagam, 1–10. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198849360.003.0001.
Повний текст джерелаАнотація:
An open long bone fracture is a serious injury not only because of the associated significant soft tissue damage but because the exposed bone is contaminated and the risk of infection increased greatly. Antibiotics should be administered intravenously as soon as possible and ideally within 1 hour of injury. Patients with open fractures should be treated in centres that can offer the full spectrum of orthoplastic services including soft tissue and bone reconstruction. Such teams are found in major trauma centres and in some specialist orthoplastic centres. Clinical assessment should include vascularity and neurological status of the of the injured limb. The wound should not be irrigated prehospital or in the emergency room. The open wound should be photographed and dressed with saline-soaked gauze covered with an occlusive film. Imaging for isolated fractures should include orthogonal radiographs and patients with multilevel injuries or polytrauma should undergo head to toe CT scanogram. All patients should be considered for venous thromboembolism prophylaxis.
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Spickett, Gavin P. "Autoimmune eye disease." In Oxford Handbook of Clinical Immunology and Allergy, 251–56. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199603244.003.0011.
Повний текст джерелаАнотація:
Overview Uveitis Tubulointerstitial nephritis and uveitis (TINU) Vogt–Koyanagi–Harada disease (VKH) Cancer-associated retinopathy and uveitis Birdshot retinopathy Scleritis Ocular cicatricial pemphigoid Sympathetic ophthalmitis Idiopathic orbital inflammation (orbital pseudo-tumour) The eye has a number of interesting immunological properties which alter the propensity for immune-mediated disease, including the curious feature that antigen injected into the anterior chamber induces tolerance rather than immunity. In addition, the eye has no true lymphatics, relatively poor vascularity, and, as the retina is an extension of the CNS, there is a blood–retinal barrier which limits passage of molecules in either direction. Ocular involvement is a common feature of many connective tissue and vasculitic diseases....
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McHugh, Kieran, and Thierry A. G. M. Huisman. "Imaging in Paediatric Oncology." In Oxford Textbook of Cancer in Children, 12–20. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198797210.003.0002.
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All superficial and abdominal masses in children should be first evaluated with ultrasound including Doppler assessment for lesion vascularity. Many benign and all malignant masses will need further evaluation with CT or MRI. For non-CNS tumours, MRI is preferred over CT, if feasible, bearing in mind anaesthesia may be needed for children under seven years of age. MRI is preferable to CT because of a lack of ionizing radiation, better soft-tissue evaluation in general, improved depiction of possible bone marrow disease, and, where present, better demonstration of spinal cord compression. Most non-CNS tumours, with the exception of neuroblastoma, would merit a routine CT of the chest for disease staging. Characteristics of individual tumour types, and the emerging role of nuclear medicine in staging and response assessment, will be mentioned in the chapter.
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Ayaz, Ercan. "Ultrasound of the Pediatric Gastrointestinal Emergencies." In Ultrasound Imaging - Current Topics [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.99759.
Повний текст джерелаАнотація:
With recent technologies, ultrasound has become an extremely useful imaging modality for evaluating children with acute abdominal symptoms. Higher frequency transducers can be used in children than in adults, owing to their small body size, the presence of less fat tissue in the abdominal wall and peritoneal cavity leading to higher resolution than computed tomography in many circumstances without exposure to ionizing radiation. Real-time ultrasound imaging provides information about motion such as peristalsis, and newly developed harmonic imaging enables improved resolution with decreased artifacts. Beyond gray-scale ultrasound, color Doppler ultrasound provides information on vascularity which increases in inflammatory processes. Point-of-care examination includes ability to focus on the symptomatic area of the patient while performing real-time ultrasound imaging. Ultrasound is sufficient for the diagnosis of several gastrointestinal diseases that cause acute abdominal pain in pediatric patients helping to an accurate patient management in the emergency settings. Common gastrointestinal indications for abdominal ultrasound in children are hypertrophic pyloric stenosis, acute appendicitis, intussusception, inflammatory bowel disease, malrotation, midgut volvulus, hernia, and necrotizing enterocolitis. In this chapter, typical sonographic findings of aforementioned diseases, and possible differential diagnoses were discussed.
Тези доповідей конференцій з теми "Tissu vascularisé"
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Yoshikawa, Hideki. "Visualization of Tumor’s Vascularity for HIFU Treatment with Tissue Motion Correction." In THERAPEUTIC ULTRASOUND: 5th International Symposium on Therapeutic Ultrasound. AIP, 2006. http://dx.doi.org/10.1063/1.2205440.
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Ionescu, Lara C., Grant H. Garcia, Tiffany L. Zachry, Gregory C. Lee, Brian J. Sennett, and Robert L. Mauck. "In Vitro Meniscus Integration Potential is Inversely Correlated With Tissue Maturation State." In ASME 2010 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/sbc2010-19369.
Повний текст джерелаАнотація:
Meniscal surgeries are amongst the most common procedures performed in orthopedics today. Clinical solutions are few and have limited success, and so partial meniscectomy is a common outcome. While tears are common in older patients, few young patients present with meniscus damage. It is unclear whether juvenile menisci are less susceptible to damage or more given to endogenous repair. Early in development, the menisci are well vascularized throughout their radial expanse, while in adults, vascularity is restricted to the peripheral rim of the tissue, near the synovial margin [1]. Tears in this vascular region often do heal in adults, while those in the avascular inner regions of the tissue do not [2]. This has led to the inference that vascularity is essential for meniscus healing and this manner of thinking has directed numerous repair strategies toward that end [3].
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Arjunan, Krishna Priya, Gary Friedman, and Alisa Morss Clyne. "Non-Thermal Dielectric Barrier Discharge Plasma Promotes Vascularization Through Reactive Oxygen Species." In ASME 2011 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/sbc2011-53664.
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Angiogenesis, the growth of new blood vessels from existing vessels, plays a key role in growth, and wound healing. Insufficient vascularization contributes to impaired wound healing in diabetic patients and the elderly. Tissue engineering is limited by the inability to adequately vascularize constructs to provide nutrients to the tissue core, thus limiting the size of engineered organs.
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Lee, Sue Hyun, Angela L. Zachman, Desirae L. Deskins, Pampee P. Young, and Hak-Joon Sung. "ROS-Responsive Scaffold for Angiogenic Differentiation of Mesenchymal Stem Cells." In ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14553.
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Vascularization of a tissue-engineered construct enables efficient transport of nutrients and waste products; it is necessary for successful long-term tissue growth and host integration. Although significant progress has been made, sufficient vascularization of engineered constructs is still a major challenge, limiting clinical applications of tissue engineering (TE) approaches [1]. Successful vascularization promotes the interactions of TE implants with host tissues, leading to efficient tissue regeneration. Therefore, there is an unmet need to develop a more efficient method to vascularize TE constructs. In particular, obtaining a reliable source of endothelial cells (ECs) that line all blood vessels is a critical and challenging step towards successful vascularization of TE constructs, empowering TE to be applied in a larger scale and scope.
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Tan, Andrea R., Jamie L. Ifkovits, Brendon M. Baker, Robert L. Mauck та Jason A. Burdick. "Electrospinning of Photopolymerizable Poly(β-Amino Ester) Networks for Fibrous Tissue Engineering". У ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-176206.
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Fiber-reinforced tissues of the musculoskeletal system, including tendon, ligament, intervertebral disc, and the knee meniscus function to transmit the high mechanical forces that arise with locomotion. As these tissues operate under demanding mechanical regimes, their structure and composition are optimized to enable these activities and to resist damage with repeated use. Hallmarks of these dense fibrous tissues include a high collagen content organized along a prevailing fiber direction that is generally coincident with the principal loading direction, as well as a lack of vascularity after skeletal maturation. While these characteristics enable function, they also predispose these tissues to a poor healing response subsequent to injury.
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Mistry, Vishal, Jaydip Desai, Suzanne Li, Hong Man, and Arthur Ritter. "Evaluation of echogenicity, vascularity index and tissue thickness of localized scleroderma ultrasound images Using MATLAB." In 2011 37th Annual Northeast Bioengineering Conference (NEBEC). IEEE, 2011. http://dx.doi.org/10.1109/nebc.2011.5778679.
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Tannenbaum, SH, K. Phoenix, P. Hegde, and KP Claffey. "The correlation of tumor vascularity as imaged by near-infrared technology with tissue distribution of angiogenic and growth promoters." In CTRC-AACR San Antonio Breast Cancer Symposium: 2008 Abstracts. American Association for Cancer Research, 2009. http://dx.doi.org/10.1158/0008-5472.sabcs-907.
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Vandenberg, Theodore W., Christopher R. Nehme, and Thomas P. James. "Application of Microforming to Create Chondrocyte Home Sites in a Natural Cartilage Matrix." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-36953.
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Articular cartilage degeneration is a central pathological feature of osteoarthritis. Cartilage in the adult does not regenerate in vivo and, as a result, cartilage damage in osteoarthritis is irreversible. With our ever-aging population, osteoarthritis has become a leading cause of disability and unfortunately, no optimal treatments for osteoarthritis are currently available. To address this problem, a research community is focused on the development of both natural and synthetic biodegradable tissue scaffolds. The scaffolds must contain depressions or holes for the purpose of chondrocyte seeding and growth in order to create an implantable construct. In addition to chondrocytes, cartilage tissue consists of the extracellular matrix (ECM). Studies of many tissue types have established that ECM plays an important role in regulating cell behavior and controlling processes such as tissue differentiation and tumor progression. Unlike most natural tissues, adult cartilage ECM is exceptionally dense and lacking in vascularity, which makes it difficult for chondrocytes to be transplanted directly into the matrix. Current methods of creating cell home sites through chemical decellularization of the ECM degrade the mechanical integrity of the cartilage tissue. The research conducted here used a mechanical, rather than chemical, method to create cell home sites. A novel micropunching machine was developed to fabricate 200 μm diameter holes in cartilage, thereby creating a porous natural scaffold while maintaining a healthy ECM. Equine articular cartilage slices were harvested from the cadaver’s back knee joint and cryo-sectioned into 100 μm thick slices. Using die clearances of 3.7%, 6.8%, and 8.9%, the results indicate that micro-scale holes can be mechanically punched in cartilage tissue. The maximum punching force showed a slight trend of decreasing as die clearance increased, but there was no statistical significance. Punching force, as well as hole size, was highly dependent on sample hydration. Upon inspection, the resulting hole sizes were approximately 50 μm to 150 um, indicating 25% to 75% shrinkage in reference to the male punch diameter. Finally, the resulting hole shape was observed to be slightly non-circular and the edges of the hole exhibited a raggedness, which was indicative of the cartilage tearing during hole punching.
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Bose, S., J. Darsell, R. Kintner, K. Feely, H. L. Hosick, and A. Bandyopadhyay. "Controlled Porosity Ceramics for Bone Graft Applications." In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-1945.
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Abstract Significant research has already been done for the development of bioceramic materials with controlled microstructures using inert, bioactive and bioresorbable ceramics. Microporous implants with controlled pore size in the range of 100-600 μm have proven to be osteoconductive. A minimum pore size of 100 μm is necessary for tissue in-growth and to provide blood supply to the connective tissues to keep them viable and healthy. Bone in-growth takes place within the inter-connected pore channels near the surface and maintains its vascularity and long term viability, and the implant serves as a structural bridge or scaffold for bone formation. Controlled porosity ceramic scaffolds were fabricated using indirect fused deposition modeling (FDM), a commercially available rapid prototyping process, with alumina and tricalcium phosphate (TCP) ceramics. Pore size and pore volumes were varied by changing road width, road gap and slice thickness of the polymeric molds. Mechanical tests were conducted to understand the influence of porosity parameters on strength degradation. In vitro tests were carried out with human osteoblast (HOB) cells to understand the effects of porosity parameters on cell growth. The paper describes the effects of porosity on the biocompatibility and bio-mechanical properties of controlled porosity alumina and TCP scaffolds.
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Hedjazi, G., G. Guterman-Ram, Joan C. Marini, N. Fratzl-Zelman, S. Bloui, P. Roschger, K. Klaushofer, and J. Zwerina. "Bone tissue characterization of a mouse model of atypical type VI osteogenesis imperfecta reveals hypermineralization of the bone matrix, elevated osteocyte lacunar density and altered vascularity." In Osteologie 2020. © Georg Thieme Verlag KG, 2020. http://dx.doi.org/10.1055/s-0039-3402837.
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