Influence of the amount of enteric polymer on the disintegration rate of pellets designed for protein delivery : in vitro and in vivo tests; ; Léonard, Françoise et alin Proceedings of Symposium on Particulate Systems, From Formulation to Prduction (1997) Detailed reference viewed: 7 (2 ULg) Malignant cell attachment to endothelium of ex vivo perfused human umbilical vein. Modulation by platelets, plasma and fibronectin.; Castronovo, Vincenzo ; et alin Thrombosis Research (1991), 62(4), 287-98 The success of blood-born metastatic spread depends upon a key event: the tumor cell arrest and attachment to the host organ vasculature. In the present study, we have investigated interactions between ... [more ▼] The success of blood-born metastatic spread depends upon a key event: the tumor cell arrest and attachment to the host organ vasculature. In the present study, we have investigated interactions between several normal and cancer cell lines and vascular endothelium in a model of ex vivo perfusion of human umbilical vein. In this system, hydrodynamic parameters are monitored and endothelial cells are kept in their original environment known to modulate their phenotype. Metastatic tumor cell adhesion to the perfused endothelium was found to be significantly higher than that of normal cells tested. Platelets and soluble plasma factors including fibronectin promoted tumor cell arrest and adhesion to endothelium. Altogether our results indicate that the ex vivo perfusion of human umbilical vein allows the study of the interactions between malignant tumor cells, circulating plasma or blood cells and the endothelium during blood-born metastatic spread. [less ▲] Detailed reference viewed: 6 (2 ULg) Perfusion of Human Umbilical Veins. A New Approach to Study the Interactions of Circulating Malignant Cells with Vascular Wall and Their ModulationsCastronovo, Vincenzo ; ; Foidart, Jean-Michel et alin Invasion & Metastasis (1988), 8(6), 332-50 Interactions of malignant or non-malignant human and rodent cells with the vascular wall were studied using perfused human umbilical cord veins. The integrity of perfused endothelium was confirmed by ... [more ▼] Interactions of malignant or non-malignant human and rodent cells with the vascular wall were studied using perfused human umbilical cord veins. The integrity of perfused endothelium was confirmed by morphological and functional criteria. Highly malignant cells in vivo adhered to the endothelial cells, as shown by scanning electron microscopy. The specific attachment of radiolabelled malignant cells to the whole vein was already maximal within 30-60 min and remained stable for perfusion flow rates ranging between 10 and 60 ml/min. It increased proportionally to the number of cells infused and could be modulated by human platelets, human fibronectin and rabbit anti-laminin antibodies. In contrast, the binding of human or rodent non-malignant cells in vivo, of human red blood cells and of human platelets to the endothelial cells was negligible under similar experimental conditions. This perfusion system therefore represents a new model for elucidating some mechanisms involved in tumour cell arrest in vivo. [less ▲] Detailed reference viewed: 77 (19 ULg) The basement membrane proteins laminin and type IV collagen in isolated villi in pre-eclampsia; Foidart, Jean-Michel ; et alin Placenta (1984), 5(6), 541-50 The distribution and concentrations of the basement membrane proteins laminin and type IV collagen were studied in isolated placental villi in normal pregnancy and in pre-eclampsia. In both cases these ... [more ▼] The distribution and concentrations of the basement membrane proteins laminin and type IV collagen were studied in isolated placental villi in normal pregnancy and in pre-eclampsia. In both cases these proteins could be localized by immunofluorescence in the trophoblast and capillary basement membranes, and occasionally also in the matrix surrounding the capillaries. The basement membrane proteins were quantified by solubilizing the villi with proteolytic enzymes and by subsequently measuring the concentrations of two resistant domains of these proteins (7-S collagen and the fragment PI, representing type IV collagen and laminin, respectively) with specific radioimmunoassays. The ratio type IV collagen:laminin was significantly higher in pre-eclamptic samples than in the controls, most probably reflecting a decrease in laminin concentration in the villi in pre-eclampsia. Such a change in the chemical composition of placental basement membranes could weaken the attachment of trophoblast cells to the underlying basement membrane and also modify the permeability and exchange properties of the villi. [less ▲] Detailed reference viewed: 6 (0 ULg) Evidence for a particular binding capacity of rat peritoneal macrophages to rat glomerular mesangial cells in vitro.; ; et al in European Journal of Clinical Investigation (1982), 12(3), 239-46 The adhesion of normal rat peritoneal macrophages to normal rat glomerular epithelial or mesangial cells has been studied in vitro after a 60 min incubation at 37 degree C. After washing, the cell ... [more ▼] The adhesion of normal rat peritoneal macrophages to normal rat glomerular epithelial or mesangial cells has been studied in vitro after a 60 min incubation at 37 degree C. After washing, the cell preparations were examined by phase contrast or scanning electron microscopy. Quantitative studies were also performed using macrophages labelled with 99mTc tin colloids. Peritoneal macrophages predominantly adhered to the cultured mesangial cells. The percent-age of labelled macrophages adhering to these cells was about 10 times higher than that of labelled macrophages adhering to the cultured epithelial cells. This percentage increased proportionally to the number of labelled macrophages added, and was strongly reduced by the prior incubation of macrophagic cells with aggregated IgG, with anti-fibronectin IgG, or with F(ab')2 fragments of anti-fibronectin IgG. Furthermore, the macrophage-mesangial cell interaction was significantly reduced by the prior incubation of mesangial cells with anti-fibronectin IgG or with F(ab')2 fragments of anti-fibronectin IgG. The data demonstrate that normal rat peritoneal macrophages preferentially adhere in vitro to normal rat glomerular mesangial cells, and that this binding may be modulated, at least, by: (a) the Fc receptor binding activity of macrophages; (b) the fibronectin molecules available at the surface of macrophages and of mesangial cells. [less ▲] Detailed reference viewed: 6 (0 ULg) |
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