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Lung Tumor Formation in Guinea Pigs by Intraperitoneal Administration of Choline.

Sahu, A.P., Shanker, R. Industrial Toxi- cology Research Centre, P.B. No. 80, Lucknow - 226 001, India.

Although considerable evidence exist about several important roles played by choline in the body, yet situations ari- sing from excess choline availability to- gether with inadvertent exposure to poten- tially toxic environmental chemicals in the body have not much been explored.

The present study reports the results of long term experiments conducted in guinea pigs, injected intraperitoneally with 50 mg of Choline chloride (5 d/wk for 8 wks) alone or in combination with a single intraperitoneal injection of 15 mg of chrysotile asbestos given after 210 days of choline injections. Choline alone produced characteristic pulmonary lesions at the termination of studies (680 days) comprising predominently of metaplasia of bronchiolar epithelium, carcinoma of alveolar perenchyma, formation of many pe- ripheral nodules of mononuclears together with development of cellular masses at pleural surfaces while lymph nodes exhi- bited collections of large masses of deep- ly stained abnormal lymphoreticular cells. However, post-treatment with asbestos resulted not only in the early onset of pul- monary lesions at 570 days but there was, in addition, an evidence of enhancement of carcinogenic lesions both in lungs and lymph nodes than choline alone.

The possible explanation of the early onset of pulmonary lesions observed in combination studies could be attributed, in part, due to the chronic availability of choline.

Value of Measurement of Tumor Associated Antigens in The Bronchial Carcinoma. Blum, U., Schneider, M., Jackisch, J., Satter, P. Klinik f~r Thorax-, Herz- und Gef~sschirurgie der J.W. Goethe-Univer- sit~t Frankfurt, Frankfurt/Main, Germany.

Tumor associated antigens are less ob- served in bronchial carcinomas than in intestinal carcinomas. Therefore an analy- sis of serum levels of tumor associated antigens seems to be not helpful for the diagnosis of a bronchial carcinoma or the detection of metastases.

We tried to increase the sensitivity and specifity of tumor associated antigens of bronchial carcinomas by analysing the serum levels of 8 antigens in the carcino- mas: CEA, SPI, TPA, Ferritin, Calcitonin,

-HCG, a-l-Antitrypsin, ACTH. The serum levels of 25 bronchial carci-

nomas were compared with serum levels of patients with benigh lung diseases. We tried to demonstrate a correlation between

serum levels of tumor associated antigens, the distribution of immunhistochemical detected tumor associated antigens in the carcinomas and the stage of lung cancer.

The Estrogen Receptor in Hlmmn Lung Cancer. Kobayashi, M., Mizuno, T., Kobayashi, S., Shibata, K., Samoto, T., Tanaka, H., Iwase, H., Satake, A., Sano, M., Masaoka, A. Nagoya City University, Medical School, The Second Depart- ment of Surgery, Japan.

The existence of the estrogen receptor in di- verse human tumors including lung cancer have been reported in recent years. We performed the measurement of estrogen receptor in human lung cancer tissue cytosol using Dextran charcoal method (DCC) and enzyme emmunoassay (EIA) method. EIA system of the estrogen receptor which was developed in our laboratory.

The positive rate of the receptor in DCC was 35.3%. Adenocarcinoma and alveolar carcinoma showed the higher positive rates among various hist-logical types of the tumor. The positive rate in EIA was 58.3%. The coincidence of the results in both methods was 48%. The coincidence was apparently lower than that (74%) found in human breast cancer.

The hormone binding ability of the recepter is unstable and easily decrease during assay procedure. Additionally, these binding assay systems can be easily interfered by the intrin- sic estrogen or nonspecific binding proteins. On the other hand, the antigenicfty of the re- ceptor molecule is more stable and does not be interfered by other proteins. Therefore, the hormone dependency of human lung cancer should be considered in the cases which show positive not only by DCC but also by EIA in the measure- ment of estrogen receptor.

Characterization of Lung Cancer Cell Surface Antigens Using Monoclonal Antibodies as Speci- fic Probes. Radosevich, J.A., Ma, Y., Salwen, H.R., Jung, L.K.F., Combs, S.G., Lee*, I., Gould*, V.E., Rosen, S.T. Northwestern University/VA Lakeside Medical Center, Section of Medical Oncology, and *Rush-Presbyterian-St. Luke's Medical Center, Department of Pathology, Chicago, IL 60611.

We have previously reported on 46-ID8 and 44- 3A6 which are two monoclonal antibodies (MCA) that react with adenocarcinoma of the lung. In this report we describe another MCA, 46-2B9, which has broader binding spectrum to lung can- cer cell lines than do 46-ID8 and 44-3A6. These MCAs recognize protein antigens having molecular weights of approximately 68,000 KD (46-ID8), 40,000 KD (44-3A6), and 35,000 KD (46-2B9) as detected by Western blot analysis or immunopre- cipitation. This data is further supported by RIA experiments in which target antigens were treated with a variety of agents including lipa- ses, proteases, and carbohydrate modifying re- agents. Live cell radioimmunoassays and immuno- fluorescent studies show that these antigens are