Search results for "Angiogenesis"
showing 10 items of 552 documents
Oxygen status of malignant tumors: pathogenesis of hypoxia and significance for tumor therapy.
2001
Hypoxic areas are a characteristic property of solid tumors. Hypoxia results from an imbalance between the supply and consumption of oxygen. Major pathogenetic mechanisms for the emergence of hypoxia are (1) structural and functional abnormalities in the tumor microvasculature; (2) an increase in diffusion distances; and (3) tumor- or therapy-associated anemia leading to a reduced O2 transport capacity of the blood. There is pronounced intertumor variability in the extent of hypoxia, which is independent of clinical size, stage, histopathologic type, and grade. Local recurrences have a higher hypoxic fraction than primary tumors. Tumor hypoxia is intensified in anemic patients, especially i…
TMA Vessel Segmentation Based on Color and Morphological Features: Application to Angiogenesis Research
2013
Given that angiogenesis and lymphangiogenesis are strongly related to prognosis in neoplastic and other pathologies and that many methods exist that provide different results, we aim to construct a morphometric tool allowing us to measure different aspects of the shape and size of vascular vessels in a complete and accurate way. The developed tool presented is based on vessel closing which is an essential property to properly characterize the size and the shape of vascular and lymphatic vessels. The method is fast and accurate improving existing tools for angiogenesis analysis. The tool also improves the accuracy of vascular density measurements, since the set of endothelial cells forming a…
Effect of antiangiogenic treatment on peritoneal endometriosis-associated nerve fibers
2012
Objective To investigate the effect of antiangiogenic treatment on experimental endometriotic lesion nerve fibers. Design Heterologous mouse model of endometriosis. Setting University Institute IVI, University Hospital La Fe. Animal(s) Ovariectomized nude mice (n = 16) receiving human endometrial fragments from oocyte donors (n = 4). Intervention(s) Endometrium fragments stuck in the peritoneum of 5-week-old female nude mice treated with vehicle (n = 8) and antiangiogenic agent cabergoline (n = 8; Cb 2, 0.05 mg/kg/day) for 14 days. Main Outcome Measure(s) Immunofluorescence analysis of von-Willebrand factor (vWF) and vascular smooth muscle cells (αSMA) for evaluating the number of immature …
Sprouting and intussusceptive angiogenesis in postpneumonectomy lung growth: mechanisms of alveolar neovascularization
2013
In most rodents and some other mammals, the removal of one lung results in compensatory growth associated with dramatic angiogenesis and complete restoration of lung capacity. One pivotal mechanism in neoalveolarization is neovascularization, because without angiogenesis new alveoli can not be formed. The aim of this study is to image and analyze three-dimensionally the different patterns of neovascularization seen following pneumonectomy in mice on a sub-micron-scale. C57/BL6 mice underwent a left-sided pneumonectomy. Lungs were harvested at various timepoints after pneumonectomy. Volume analysis by microCT revealed a striking increase of 143 percent in the cardiac lobe 14 days after pneum…
Endothelial capillaries chemotactically attract tumour cells.
2001
Directional migration of capillaries towards tumour implants is generally assumed to be regulated by chemotaxis. Preliminary evidence has also been presented for the existence of a reverse chemotactic signalling pathway, with capillaries attracting tumour cells via paracrine factors. By using a variety of endothelial cell types and tumour cell lines, this study has systematically investigated chemotaxis between endothelial cells and tumour cells in two- and three-dimensional systems. Checkerboard analysis revealed faint attraction of human umbilical vein endothelial cells (HUVECs), but not porcine aortic endothelial cells (PAECs), by tumour cells. In reverse, both PAECs and HUVECs potently …
Dextran sulfate sodium leads to chronic colitis and pathological angiogenesis in Endoglin heterozygous mice
2010
Pathological angiogenesis is an intrinsic component of chronic intestinal inflammation, which results in remodeling and expansion of the gut microvascular bed. Endoglin is essential for endothelial cell function and physiological angiogenesis. In this study we investigated its potential role in the regulation of inflammation by testing the response of Endoglin heterozygous (Eng(+/-)) mice to experimental colitis.C57BL/6 Eng(+/-) and littermate control mice drank water supplemented with 3% dextran sulfate sodium (DSS) for 5 days and were monitored for up to 26 days for clinical signs of colitis. Inflammation, crypt damage, and angiogenic index were scored on histological sections of distal c…
Inflammation-Induced Intussusceptive Angiogenesis in Murine Colitis
2010
Intussusceptive angiogenesis is a morphogenetic process that forms new blood vessels by the division of a single blood vessel into two lumens. Here, we show that this process of intraluminal division participates in the inflammation-induced neovascularization associated with chemically induced murine colitis. In studies of both acute (4-7 days) and chronic (28-31 days) colitis, intravital microscopy of intravascular tracers demonstrated a twofold reduction in blood flow velocity. In the acute colitis model, the decreased velocity was associated with marked dilatation of the mucosal plexus. In contrast, chronic inflammation was associated with normal caliber vessels and duplication (and trip…
Comprehensive three‐dimensional morphology of neoangiogenesis in pulmonary veno‐occlusive disease and pulmonary capillary hemangiomatosis
2019
Abstract Pulmonary veno‐occlusive disease (PVOD) is a rare lung disease characterized by fibrotic narrowing of pulmonary veins leading to pulmonary hypertension (PH) and finally to death by right heart failure. PVOD is often accompanied by pulmonary capillary hemangiomatosis (PCH), a marked abnormal proliferation of pulmonary capillaries. Both morphological patterns often occur together and are thought to be distinct manifestations of the same disease process and accordingly are classified together in group 1′ of the Nice classification of PH. The underlying mechanisms of these aberrant remodeling processes remain poorly understood. In this study, we investigated the three‐dimensional struc…
Comparative analysis of mast cell count in normal oral mucosa and oral pyogenic granuloma
2011
Introduction: Mast cells are large granular cells that arise from a multipotent CD 34+ precursor in the bone marrow normally distributed throughout connective tissues. The most common method to study role of mast cells in any altered condition involves their identification and quantification in that condition and compare the values with that of the normal average count or number of mast cells. The present study was thus, undertaken to identify as well as quantify mast cells in oral pyogenic granuloma and compare it with the average count of mast cells in normal oral mucosa, thus aiming to assess the changes in count of mast cells in oral pyogenic granuloma. Materials and Methods: Ten cases …