Lymphatic metastasis of tumour; persistent transport of cells

Summary A model of lymphatic metastasis established by injecting Walker rat carcinoma cells into the rat footpad was used to study the output of tumour cells from the footpad. The lymphatic efferent from the footpad was cannulated in a group of rats with advanced neoplasm; it was shown that the output of tumou cells was continuou over periods up to 90 min and ranged from 10²–10⁵ cells/min.Acknowledgment. This work was supported by a grant from the National Cancer Institute of Canada to C.R.F. and I.C. We are grateful to Mrs W. Kao and Mr I. Etches for meticulous technical help and to the Photographic Section, Department of Pathology for illustrations. Dr V.S. Gupta of Veterinary Physiology, University of Saskatchewan supplied the tumour for transplantation.     

Une note concernant la centrifugation fractionnée de foie de rat

Summary Significant differences were observed in enzymic composition of L and P fractions between fasting and fed animals. The L fraction contains a smaller percentage and the P fraction a higher percentage of the enzymic activity of the homogenate when the rat is fed, which can be explained by the sedimentation in the L fraction of a high proportion of the glycogen accumulated in the liver of fed animals. The presence of this component changes the organization of the centrifugation pellet so that, during the decantation of the L fraction, subcellular structures sedimenting in this fraction are sucked off and recuperated in the next centrifugation pellet, i.e. in the microsomal P fraction.     

Centromere nature of the chromosomes ofRanatra (Heteroptera)

Zusammenfassung Histologisch-cytologische Untersuchungen zeigen, dass die Chromosomen vonRanatra monozentrisch sind. Der Befund steht im Gegensatz zu Ergebnissen anderer Autoren an andern Heteroptera-Arten, die polyzentrische Chromosomen haben. Die Natur des Centromers ist also bei verschiedenen Arten der Heteropteren verschieden.