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.     

Dissociation of urease in acetate buffer of pH 3.5 with retention of the enzymatic activity

Riassunto Le molecole dell'urease (peso molecolare 480,000, coefficiente di sedimentazione 18,6 S) si dividono a metà quando trattate con tampone acetato, 0,1M, pH 3,5. Inizialmente, l'attività enzimatica è 40% di quella al pH 7 (tampone fosfato, 0,34M) e la dissociazione è riversibile. Prolungata esposizione al pH 3,5 causa una lenta denaturazione, con perdita dell'attività e dell'abilità di ricostituirsi.

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This work was supported by grant No. GM 13,900 and by Career Development Award No. 5K3 GM 13,489 (to G. G.) from the National Institutes of Health.