Kaposi's sarcoma (KS) is an angioproliferative disease characterized by proliferating spindle-shaped cells, angiogenesis, and inflammatory cell infiltration. Several lines of evidence suggest that KS is a multifocal cytokine-mediated disease of vascular origin. Because metalloproteinases (MMPs) are important enzymes involved in angiogenesis, we studied their activity in five different KS-derived cell lines and compared these data with those obtained with human umbilical vein endothelial cells (HUVEC). We focused on the activity of the 72- and 92-kd type IV collagenases because these enzymes are thought to play an important role in the process of tumoral invasion. Nonstimulated HUVEC released a weak 72-kd collagenase activity and no 92-kd collagenase activity, as determined by zymographic analysis. Stimulation of HUVEC with phorbol myristate acetate (PMA) or TNF-alpha increased the 72-kd collagenase activity and also induced a 92-kd collagenase activity. By contrast, KS-derived cells constitutively released significant 72- and 92-kd collagenase activities. The basal release of these enzymes by KS cells was further enhanced by TNF-alpha or PMA. Conversely after in vivo exposure to chemotherapy, KS-derived cells showed a downregulation of the production of MMPS that could be reversed by the addition of TNF or PMA. These results suggest that KS cells have constitutive features of activated cells that have an invasive and metastasizing potential.

Directed control of cell metabolism by a modification of the physicochemical conditions (presence of Na-butyrate and modification of the temperature) was used to modulate the productivity of human recombinant tissular plasminogen activator (t-PA) expressed under control of SV40 promoter in Chinese Hamster Ovary (CHO) cell lines. We showed that both by adding Na-butyrate or lowering temperature from 37 degrees C to 32 degrees C there is an increase in the amount of t-PA excreted, while cell growth is significantly reduced. The treatments also increased the intracellular amount of t-PA. We measured the distribution of cell cycle phases by cytometry and used a modification of the equations of Kromenaker and Srienc (1991, 1994 a, b) to analyse the intracellular t-PA production rate in the different cell cycle phases. Intracellular t-PA was shown to accumulate in G1 phase in all conditions (at 37 degrees C, at 32 degrees C and in presence of butyrate). Moreover, we have shown that the distribution of the time cells treated by butyrate are maintained in the G1cell cycle phase is significantly increased. t-PA produced in the different cell culture conditions tested was analysed by zymogram and western blotting: neither butyrate, neither the shift of temperature changed significantly the overall quality of the protein. The N-glycan patterns of recombinant human t-PA was also analysed with carbohydrate-specific lectins. Butyrate caused a transitory increase in N-linked complex high-mannose oligosaccharides without any effect on the sialic acid content of t-PA.

Quality of potatoes in chips industry is estimated from the intensity of darkening during frying. This is measured by a human jury, subject to numerous factors of variation. Gray level intensities were obtained for the apex, the center, and the basal parts of each chip using image analysis of frying assays. We then tested a feedforward artificial neural network designed to associate these data with color categories. It behaved in good agreement with human estimations, obtaining correlation coefficients of 0.972 for training data and of 0.899 for validation data. A systematic study of the response of the model allowed understanding the criteria of evaluation used by the human operators.

JFS E: Food Engineering and Physical Properties . .Anomalous regions could be distinguished on 3 potato varieties. Bruises that were very dissimilar in appearance Anomalous regions could be distinguished on 3 potato varieties. Bruises that were very dissimilar in appearance Anomalous regions could be distinguished on 3 potato varieties. Bruises that were very dissimilar in appearance Anomalous regions could be distinguished on 3 potato varieties. Bruises that were very dissimilar in appearance Anomalous regions could be distinguished on 3 potato varieties. Bruises that were very dissimilar in appearance were correctly identified, and some particular defects such as green spots could be located as well. were correctly identified, and some particular defects such as green spots could be located as well. were correctly identified, and some particular defects such as green spots could be located as well. were correctly identified, and some particular defects such as green spots could be located as well. were correctly identified, and some particular defects such as green spots could be located as well.

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