Table 2 72-h culture: Chromosome abnormalities in peripheral lymphocytes of the fishermen, data from 1965 to 1967. cases examined No. of cells analyzed Aneuploid Control 10 693 2. 88 Fishermen 13 881 2.05 Fishermen 15 1102 2. 90 Fishermen 1967 16 1248 2. 48 10 750 2. 27 12 950 2.00 No. of Cases 1965 1966 48-h culture :‘ Fish | 1965 Fishermen 1967 cells % i | unstable Stable cells % (i )* 0.14 onl cells % (/)* i i 0.14 \ (1/10) (1/10) (9/13) (3/13) (14/15) (5/15) first signs of regenerat with following ; posure, So 0. 46 2. 23 3.45 2. 88 (15/16) The hematologic 0. 45 1954 were reported * 0. 56 (6/16) the dose soon a ne 1. 20 (6/10) 0. 67 (4/10) (9/12) (6/12) Generally speakii sons. should findings. From*bi1S } to decide the theral As to the Jap 0.74 2.11 abnc and morphological a tions of recovery were ‘ necessary to detect mat« observed in he * Number of cases showing the abnormal cells per total number of cases examined. so high (Table 2). 2. Unstable abnormalities such as dicentrics, 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. c. 5. stable cells with deletion of a chromosome .:.29 per cent stable cells with excessive chromosome material...4 per cent In 3 cases small chromosomes which are similar to the Ph! chromo- some 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 valuesof stable and of unstable cells were higher in proportion to the extent of the initial damage. Minimum values of neutrophils roughly corresponded to the estimat- ed external radiation dose. tem => eee tte mn - Hematological T. KUMATORI 70 4 Amano, 5. (1953) : Gakujutsu 5 Anprews, G. A+ Diagnosis * Organizatior Cronkite, E.P-. lonizing Re Washingtol Guskova, A.B. Conferenct New York. Hasteruk, B. Conferen¢ New York HEMPELMAN, ~ Medicine 7. Chromosome abnormalities in bone marrow were observed in 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. ISHIHARA, TIsnmmana, T North H i T- SPERMATOGENESIS Janmers As a generative tissue, spermatogenesis has many similarities with hematopoiesis. Therefore, the changes of number of spermatozoa is described for einitate Kimura, K. reference. The number of spermatozoa decreased, and minimum numbers were obtained in 16 cases about 8 monthsafter the exposure. Lowering of mobility 1, T- Influer the Fr