Cellular injury in vitro: phase contrast studies on injured cytoplasm

Unfixed, compressed acinar cells of rat pancreas, isolated by mechanical and enzymatic means, were examined by phase microscopy and photomicrographed using 35 mm film and electronic flash illumination. Similarly, observations were made on Walker carcinoma cells; in addition, these cells were treated with solutions containing either phosphatidase A or enzyme inhibitors. Acinar cells contained, besides nuclei, perinuclear droplets and secretion granules, various membranous and vacuolar structures. The basal cytoplasm showed parallel dark lines interpreted as endoplasmic reticulum. In some cells, fragmentation of the reticulum was followed by the direct incorporation of fragments into simple myelin figures. In other cells it appeared that phase-lucent linear structures and vacuoles were derived by dilatation of cisternae of the endoplasmic reticulum. Perinuclear fluid collections arose either by dilation of the perinuclear cisternae of the endoplasmic reticulum or by fluid dilatation of the nuclear envelope. Phosphatidase A disrupted early vacuoles of Walker carcinoma cells. From this and the direct involvement of elements of the endoplasmic reticulum in myelin figures, it was concluded that the membranes limiting the endoplasmic reticulum incorporate phosphatides in continuous layers. While many severely injured cells formed large vacuoles, others developed concentrically laminated myelin figures; it was concluded that both types of structure derived from phosphatides liberated intracellularly, the vacuoles by vesicular myelin figure formation.

THE TRANSPLANTABILITY OF TUMOURS BY INTRAVENOUS AND INTRALYMPHATIC ROUTES

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THE ASSAY OF THE EFFECT OF CHEMICAL AGENTS ON TUMOUR INVASION USING CHICK EMBRYOS

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THE FATE OF CIRCULATING WALKER 256 TUMOUR CELLS INJECTED INTRAVENOUSLY IN RATS

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TEMPERATURE-DEPENDENT HISTOTYPIC CHANGES IN WALKER CARCINOSARCOMA IN THE CHORIOALLANTOIS

Solid tumors grew in the chorioallantois of chick embryos after the topical inoculation of ascites tumor cells. The microscopic character of the growth varied depending on the temperature of incubation. At 32.5 degrees C a sarcomatous appearance was prominent; at 37.5 degrees C carcinomatous structure in several alveolar patterns predominated; at 42.5 degrees C growth was that of a "giant cell" carcinoma.

COMPARISON OF PANCREATIC AND STEROID DIABETES IN RESPECT TO TUMOR GROWTH AND GLYCOSURIA

Sexually mature male rats were made severely diabetic by either pancreatectomy or daily injection of large doses of cortisone acetate. One half of the animals were then made host to Walker Carcinoma 256. The tumor suppressed the glycosuria in all of the animals, but the effect was greater in steroid diabetes than in pancreatic diabetes. Diabetogenic doses of cortisone inhibited the growth of tumor to a greater extent than did pancreatic diabetes. The depancreatized tumor host is partially resistant to the diabetogenic action of cortisone.