Human radiation cytogenetics. Special reference to human chromosomes (in Japanese)
The topics discussed include relationship between cell cycle and the incidence of chromosome aberration; various types of aberration; lymphocyte culture; relation of cultured lymphocyte with radiation-induced chromosome aberration, especially with radiation dosage. The types of chromosome aberration vary depending upon the period of cell cycle exposed to radiation. Those that are irradiated during mitosis form chromatid type aberration when exposed after S period and chromosome type aberration when exposed in G/sub 1/ and the first half of S period. Those exposed during interphase form exchange aberration due to misrepair. Chromatid type aberration includes single chroinatid aberration, and isochromatid aberration ranging from isochromatid break to complete and incomplete repair. Chromosome type aberration is further divided into single break and compound break. Single break is characterized by terminal deletion with formation of acentric fragments. Compound break is divided into intrachange including paracentric inversion, acentric ring and interstitial deletion, pericentric inversion, and ring and acentric fragment; and interchange including reciprocal translocation and dicentric chromosome and acentric fragment. The characteristics of lymphocyte culture are: (1) lymphocytes are generally in the earlier stage of DNA synthesis, thus are fairly homogeneous; (2) addition of PHA (phytohemagglutinin) stimulates DNA synthesis, causing first mitosis 48 hrs after beginning of culture and the second, 72 hours; (3) an assumption is made that some lymphocytes stay alive for years without loosing immunological activity. These are important keys to the qualitative as well as quantitative studies of radiation-induced chromosome aberration. No significant difference due to dose rate is observed. However, the kinds of radiation results in varied rate of incidence of aberration; RBE of neutrons in relation to chromosome aberration proved to be two to three times higher than x rays or gamma rays. (JA)
- Research Organization:
- Atomic Bomb Casualty Commission, Hiroshima
- NSA Number:
- NSA-29-029763
- OSTI ID:
- 4332102
- Journal Information:
- Shoni Igaku, v. 6, no. 1, pp. 185-216, Other Information: Orig. Receipt Date: 30-JUN-74; Bib. Info. Source: JA (JA)
- Country of Publication:
- Japan
- Language:
- Japanese
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Detection of chromosomal abnormalities in human sperm
PERSISTING CHROMOSOME ABERRATIONS IN CELL CULTURES FROM IRRADIATED HUMAN SKIN
Related Subjects
*CHROMOSOMAL ABERRATIONS- RADIOINDUCTION
*CHROMOSOMES- GENETIC RADIATION EFFECTS
BIOLOGICAL REPAIR
BIOSYNTHESIS
CELL CYCLE
CELL DIVISION
CHROMATIDS
DICENTRIC CHROMOSOMES
DNA
DNA REPLICATION
GAMMA RADIATION
IONIZING RADIATIONS
LYMPHOCYTES
MITOSIS
NEUTRONS
RADIATION DOSES
RADIATION INJURIES
RBE
RING CHROMOSOMES
TIME DEPENDENCE
X RADIATION