Characterization of human malignant melanoma cell lines. VII. Glycoprotein synthesis and shedding as revealed by [3H]glucosamine labeling

We have established conditions for the study of membrane glycoprotein synthesis and turnover in cultured human malignant melanoma cell lines using the labeled precursor [3H]glucosamine. Uptake of label increased parallel with cell growth, reaching a steady state in resting cultures. Fifteen to 30% of incorporated label can be released from the cells by trypsin treatment depending on the conditions of exposure to the enzyme, and about 50% of the incorporated label is spontaneously shed from the cells within 96 hr of incubation. Labeling in exhausted medium gave a 5- to 8-fold increase in uptake which was inhibited by addition of glucose (2 mg per ml) into the culture medium. The percentage of trypsin-releasable material was identical in fresh and exhausted medium; however, the percentage shed was less in cells initially labeled in exhausted medium. These data provide background information for further studies on the antigenic composition of the glycoproteins of cultured melanoma cells.     

Parameters for the measurement of long-term effects of an orally administered drug in organic and functional circulatory disorders. Preliminary communication

In many cases of drug-induced allergic hepatitis, peripheral lymphocytes were transformed by the stimulation with a given drug in the presence of autologous serum. However, when rat liver microsome fraction of soluble liver specific antigen fraction was added to the culture instead of autologous serum, the drug-induced lymphocyte transformation was more efficiently seen than autologus serum, while rat liver mitochondria fraction was less effective. On the other hand, in the cases of allergic drug eruption which did not show any liver injury, the addition of liver subcellular fractions were much less effective to induce the lymphocyte transformation than autologous serum. These results may suggest that liver subcellular component is involved in pathogenesis of drug-induced allergic hepatitis.     

Portal vein thrombosis in adults

Idiopathic thrombotic occlusion of the extrahepatic portal vein is one of the commonest causes of portal hypertension in adult Blacks. The condition occurs more frequently in men and may be accompanied by evidence of minor functional impairment of the liver. Associated pancytopenia is quantitatively related to the degree of splenomegaly. Assessment of a spectrum of variables of blood coagulation and fibrinolysis, while failing to shed light on the possible pathogenesis, does suggest a rational basis for thrombolytic therapy.     

An evaluation of transverse axial emission tomography of the brain in the clinical situation

The Aberdeen section scanner provides, in addition to conventional views, a display of the distribution of radioactivity in a tomographic section of the brain. This paper examined the value of this additional information. Scans of lesions confirmed pathologically or radiologically, along with normal and doubtful cases, were examined after a careful randomization procedure. During the course of the study each set of conventional views was examined twice, once without and once with a tomographic section view. In two out of 29 cases (7%) the lesion was diagnosed only with the aid of the tomographic section scan. Improved accuracy of diagnosis with the tomographic section view was significant at the 1% level or better.