Enzyme content of hepatocellular lysosomes in the liver of the tumour-bearing mouse.

An increase in the number of hepatocellular lysosomes was not detected in mice bearing the solid or ascites forms of Sarcoma 180 or Ehrlich's tumour. Despite this, biochemical studies showed significant increases in acid phosphatase, cathepsin-D and beta-galactosidase. This difference between morphological and biochemical observations is explained by the fact that only gross increases in lysosome population are likely to be detected in the small samples examined with the electron microscope, but by biochemical methods whereby many grams of tissue are analysed finer changes may be detected. As far as is known at present there is an increase in hepatocellular lysosomes and/or lysosomal enzymes in tumour-bearing mice, rats and man and no exception to this exists.

Lysozyme production by a granuloma in vivo: output in blood and lymph in relation to ultrastructure and immunochemistry.

The output of lysozyme into the venous and lymphatic drainage of a B.C.G. experimental granuloma has been studied. There is a massive output of lysozyme by both routes maximal in the lymph at 28 days, and in the serum at 35 days after induction of the granuloma. There is no similar excretion of acid phosphatase. The lactic dehydrogenase level both in blood draining the granuloma and blood draining the normal limb is elevated but not in precise synchrony with lysozyme output. Macrophages in the granuloma show ultrastructural features suggestive of secretion of dense granules, by appearance of electron dense material in the Golgi zone, and condensation therefrom. Granules are discharged on to the surface of lipid droplets, presumably representing attempted phagocytosis, but are not discharged elsewhere on the cell surface. Granules are released by cell disintegration both of macrophages and polymorphs. Lysozyme was demonstrated immunocytochemically in macrophage granules. The macrophages in the granuloma are biosynthetically active as shown by uptake of tritiated tyrosine. The findings support the view that granulomas export lysozyme and that this is due partly to exocytosis of material by macrophages on to the surface of lipid globules and partly to cell disintegration.

Enzyme content of hepatocellular lysosomes in the tumour-bearing rat.

An increase in the number of hepatocellular lysosomes is detectable with the electron microscope in rats bearing a carcinogen-induced sarcoma but not in rats bearing a transplanted Walker tumour. Biochemical studies show an increase in lysosomal enzymes in the liver of both groups of rats, but the increase in the rats bearing a carcinogen-induced sarcoma was greater than that in rats bearing a Walker tumour. This difference is explained by the fact that only gross increases in lysosomal population are likely to be detected in the small samples examined with the electron microscope, but by biochemical methods whereby many grams of tissue are analysed, finer changes may be detected. The collective data to date indicate that an increase in hepatocellular lysosomes and/or lysosomal enzymes occurs in rats and man bearing a variety of tumours and to this there is, as yet, no known exception.

Comparison of 3-kit methods for determination of human chorionic somatomammotropin by radioimmunoassay.

1. Three commercially available kit procedures for human chorionic somatomammotropin (HCS) were investigated. 2. The comparison of the methods included procedure, accuracy, precision, sample requirement and time required for analyses. 3. While one kit gave significantly higher values and requires more time to obtain results, each of 3 procedures was concluded to provide clinically useful information.