Nagoya Journal of Medical Science

Binding of epidermal growth factor (EGF) to its receptor was evaluated in thc four cultured choriocarcinoma cell lines BeWo, NaUCC-l, NaUCC-2. and NaUCC-3. Also, the effect of the anti-tumor drugs actinomycin-D (Act-D) and methotrexate (MTX) on the EGF receptor binding was invcstigated in these cell lines. Incubation of these cells with [¹²⁵I]EGF at 37°C resulted in a higher binding than that at 22°C or at 4°C. Thesc bindings were saturable during 30- to 60-min incubation, and were specific and reversible. Scatchard analysis showed that the maximal number of receptor binding sites was 2.89 x 10³/cell in BeWo cells, 2.04 x 10³/cell in NaUCC-1 cells, 1.84 x 10³/cell in NaUCC-2 cells, and 1.01 x 10³/cell in NaUCC-3 cells. Preincubation with Act-D or MTX for 24 hr decreased the number of receptor binding sites (26 %-53 %) and slightly increased the receptor binding affinities. Combination of the two drugs resulted in a further diminution of EGF receptor binding sites in BeWo, NaUCC-1, and NaUCC-3 cells, respectively, but reversed the Act-D effect in NaUCC-2 cells. These results indicated that choriocarcinoma tissue is rich in EGF receptors, that the anti-tumor drugs Act-D and MTX diminish the receptor binding sites in the tissue. and suggest that MTX might induce a drug resistance to Act-D in some choriocarcinoma tissue.

Two cases of vinyl-chloride-induced angiosarcoma of the liver were investigated with special reference to the invasive character of malignant endothelial cells. Histological findings of the liver were similar in both cases. The liver angiosarcoma was multicentric and consisted of three portions: a peripheral parenchymal area, an intermcdiate mottled area, and a central cavernous area. Microscopically thc intermediate area showed a mixture of fibrosis and cell infiltration of various patterns. At the periphery, yellowish brown parenchymal tissues remained and were always associated with sinusoidal changes. from non-cellular dilatation to trabecular growth of the small round cells. Under electron microscope. the small round cells showed direct contact with red blood cells and hepatocytes. Thus, the sinusoidal small cell infiltration is thougth to be an initial lesion of angiosarcomatous transformation. Because none of the liver is free from these sinusoidal changes. partial hepatectomy would not be indicated even in a patient with few cavernous lesions.

The levels of serum deoxythymidine kinase (s-dTK) were investigated for 127 patients suffering hematological malignancy by a sensitive method using [¹²⁵I]-iododeoxy-uridine as substrate. It was found that the deoxythymidine kinase activity in the sera of these patients was higher than the normal levels in adults. It was also found that the levels of s-dTK in the progressive stage were much higher than those in the indolent stage. These results suggest that high levels of s-dTK in hematological malignancy may reflect the extent of disease and that this activity may he derived from proliferating leukemic cells. The deoxythymidine kinase activity in the extracts derived from cultured cell lines and clinical specimens indicated that leukemic cells contained much higher activity than normal cells.

In 1984 the Public Health Burcau of Nagoya City began a new health check-up program to encourage citizens aged 40 years to have a medical examination. The rate of participation was 46.6% greater than that of the previous program; however, at about 16%, it was still low. From the survey in Moriyama Ward following results were suggested. Housewives and female part-time workers who had not had a health examination during the previous year showed participation rates of 32.7% and 42.4%, respectively. It would seem that the low rate of participation in the health examination program conducted in the metropolitan area by the municipal Public Health Bureau is due to the existence of many medical care facilities, and the fact that 64.6% of men and 52.6% of women had undergone a medical examination in the year preceding the program.
Total screening rates became 69.7% in males and 66.0% in females. Participation rates of 32.7% and 42.4% were achived by unemployed women and by women with part-time employment, respectively, who had no experience of screening in the previous year. Total screening rates were 63.7% for the unemployed women and 82.1% for the part-time women.