70 Hematological T. KUMATORI Table 2 Chromosome abnormalities in peripheral lymphocytes of the fishermen, data from 1965 to 1967. 72-h culture: Cases No. of cases examined No. of cells analyzed Aneuploid cells °% Control 10 693 2. 88 Fishermen 1965 Fishermen 1966 Fishermen 13 881 2.05 15 1102 2.90 16 1248 2. 48 1967 Stable cells % (;)* unstable cells % (/\* 0. 14 10 750 2. 27 Fishermen 12 950 2.00 1966 1967 al abnor! re ob and morphologic © Were ry ve co re of tions generatto first signs of re g ! posure bs in with Follow 0.14 (1 10) (1/10) 2. 28 (9/13) 3.45 (14/15) 2. 88 0. 46 (3/13) 0. 45 (5:15) 0. 56 (15 16) (6/16) 48-h culture: Fishermen E 1. 20 0. 67 (6:10) (4/16) (9'12) (6/12) 2.11 0.74 * Number of cases showing the abnormal cells per total number of cases examined. l The hematologica rted wi 1954 were repo ng eaki Cenerally sp r the ac dose soon afte d be deci sons should this pe findings. From y e therap to decide th pan As to the Ja t necessary to detect ato observed in hem so high (Table 2). 2. Unstable abnormalities such as dicentries, etc. were observed (Table 2). 3. The frequency of stable abnormalities was remarkably higher than in controls (Table 2). 4. The detailed analysis of stable cells revealed that stable abnormalities were divided following 3 types: a, stable cells with balanced chromosome constitution ...67 per cent b. stable cells with deletion of a chromosome...29 per cent c. stable cells with excessive chromosome material...4 per cent 5. In 3 cases small chromosomes which are similar to the Ph! chromosome were found. 6. The examined fishermen wereclassified in3 groups according to the degree of the injuries indicated by the minimum values of neutrophils shown shortly after the exposure. It was found that the mean values ofstable and of unstable cells were higher in proportion to the extent of the initial damage. Minimum values of neutrophils roughly corresponded to the estimated external radiation close. 7. Chromosome abnormalities in bone marrow were observedin 5 cases, All of these abnormalities were limited to stable abnormalities. While stable cells in the peripheral lymphocytes showed various karyotypes of their own, these in the bone marrow were limited to only a few karyotypes. - SPERMATOGENESIS As a generative tissue, spermatogenesis has many similarities with hematopoiesis. Therefore, the changes of number of spermatozoa is describedfor reference. The number of spermatozoa decreased, and minimum numbers were obtained in 16 cases about 8 months after the exposure. Lowering of mobility 533): ¢ AMANO, S- (19 u Shi ts ju ku Ga A. § ANDREWS, G. c Diagnosis an , on Organizati P., CRONKITE, E. Jonizing Rad Washington, a CGuskova; A.K. Conference New York. jHASTERLIK, R. Conference New York. HEMPELMAN, L Medicine, - an ISHIHARA, T. a T. [SHIHARA North Ho a ISHIHARA, T. 942. AMMET, H.P. World tI. . KIKUCHI, Tt stitute £ KIMURA, K., Influenc the Pro z