Ermittlung des Volumenstroms mittels Differenzdruck-Durchflussmessers

Die vorliegende Arbeit befasst sich mit der Ermittlung von Volumen- bzw. Massendurchflüssen. Die sieben Methoden, die für die Messung verwendet werden können, werden in kurzer Form beschrieben. Das Wirkdruck- bzw. Differenzdruckverfahren wird dabei im Detail erläutert. Differenzdruck-Durchflussmesser, auch Wirkdruckgeber genannt, sind Normteile und daher in der ISO 5167 mit ihren Anwendungsgrenzen niedergeschrieben. Im letzten Kapitel werden Durchflusskalibrierungen für Wirkdruckgeber behandelt. Durch diese kann der reale Durchflusskoeffizient ermittelt werden. Kalibrierungen sind notwendig, wenn eine hohe Genauigkeit erforderlich oder der Durchflussmesser außerhalb der Norm ist. Anhand von Beispielen soll gezeigt werden, ob die Werte von Wirkdruckgebern, die außerhalb der Norm sind, Gültigkeit habe

Opposite regulation of tenascin-C and tenascin-X in MeLiM swine heritable cutaneous malignant melanoma

International audienceInteractions between tumour cells and surrounding extracellular matrix (ECM) influence the growth of tumour cells and their ability to metastasise. It is thus interesting to compare ECM composition in tumours and healthy tissues. Using the recently described MeLiM miniature pig model of heritable cutaneous malignant melanoma, we studied the expression of two ECM glycoproteins, the tenascin-C (TN-C) and tenascin-X (TN-X), in normal skin and melanoma. Using semiquantitative RT-PCR, we observed a 3.6-fold mean increase of TN-C RNAs in melanoma compared to normal skin. Both stromal and tumour cells synthesise TN-C. On the contrary, TN-X RNAs decreased 30-fold on average in melanoma. This opposite regulation of TN-C and TN-X RNAs was confirmed at the protein level by indirect immunofluorescence. Whereas pig normal skin displayed a discrete TN-C signal at the dermo-epidermal junction, around blood vessels and hair bulbs, the swine tumour showed enhanced expression of TN-C in these areas and around stromal and tumour cells. In contrast, normal skin showed a strong TN-X staining at the dermo-epidermal junction and in the dermis, whereas this signal almost completely disappeared in the tumour. The results presented here describe a dramatic alteration of the ECM composition in swine malignant melanoma which might have a large influence on tumourigenesis or invasion and metastasis of melanoma cells.Interactions between tumour cells and surrounding extracellular matrix (ECM) influence the growth of tumour cells and their ability to metastasise. It is thus interesting to compare ECM composition in tumours and healthy tissues. Using the recently described MeLiM miniature pig model of heritable cutaneous malignant melanoma, we studied the expression of two ECM glycoproteins, the tenascin-C (TN-C) and tenascin-X (TN-X), in normal skin and melanoma. Using semiquantitative RT-PCR, we observed a 3.6-fold mean increase of TN-C RNAs in melanoma compared to normal skin. Both stromal and tumour cells synthesise TN-C. On the contrary, TN-X RNAs decreased 30-fold on average in melanoma. This opposite regulation of TN-C and TN-X RNAs was confirmed at the protein level by indirect immunofluorescence. Whereas pig normal skin displayed a discrete TN-C signal at the dermo-epidermal junction, around blood vessels and hair bulbs, the swine tumour showed enhanced expression of TN-C in these areas and around stromal and tumour cells. In contrast, normal skin showed a strong TN-X staining at the dermo-epidermal junction and in the dermis, whereas this signal almost completely disappeared in the tumour. The results presented here describe a dramatic alteration of the ECM composition in swine malignant melanoma which might have a large influence on tumourigenesis or invasion and metastasis of melanoma cells