IONIZING RADIATIONS AND CONGNEITAL ANOMALIES OF THE NERVOUS SYSTEM

Journal Article · Thu Nov 01 04:00:00 EST 1962 · Military Med.

OSTI ID:4740033

Rugh, R

There is no longer any doubt that penetrating ionizing radiations can so interfere with development that congenital anomalies may result from exposures at any time from fertilization of the ovum until after birth, and the majority of such anomalies involve the nervous system. The effects of ionizing radiations at different stages of embryonic development are related hoth to tissues and organs actively differertiating at the time, and the level of exposure. The earliest cleavage stages are the most radiosensitive in terms of lethality and no threshold has been established. Irradiation during organogenesis is most likely to produce gross congenital anomalies, particularly of the certral nervous system. Exposures during the later stages of pregnancy show better survival but are more likely to respond in terms of functional rather than gross structural anomalies. Such late fetuses possess gonads and germ cells which can accumulate the mutations induced by ionizing radiations, for which no mutational threshold has been established. Ionizing radiations produce their effects by killing or maiming cells, or producing mutations. When cells are killed the resultant fetus will be proportionately deficient. When maimed cells persist, they may so interfere with morphogenesis that either or both structural and functional defects follow. The terms survival, recovery, and normality have been confused in radiobiological literature. They are not synonymous. It is becoming clearer that an irradiated embryo may indeed survive, appear to be recovered but in fact exhibit morphological and/or functional deviations from the normal at various periods during the post-natal life of the individual. In view of animal experiments showing deleterious effects of 10 rads delivered to the embryo, and the probability that the human embryo of comparable developmental stage is similarly radiosensitive, it is suggested that this dose be the limit allowed to the early human embryo or duing its first 6 weeks of developmert. This dose is more than that esttmated as the 30 year accumulated gonad exposure from natural, medical and fallout sources. A suggestion is made relative to the mechanism of embryonic damage by ionizing radiations, affecting the DNA--- specific differentiation protein chain reaction. (auth)

• Research Organization: Columbia Univ., New York
• NSA Number: NSA-17-007857
• OSTI ID: 4740033
• Journal Information: Military Med., Journal Name: Military Med. Vol. Vol: 127
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ANIMALS
BIOCHEMISTRY
BIOLOGY AND MEDICINE
EMBRYOS
GENETICS
GONADS
LIFETIME
MALFORMATIONS
MAN
NERVOUS SYSTEM
NUCLEIC ACIDS
PREGNANCY
PROTEINS
RADIATION DOSES
RADIATION INJURIES
RADIOSENSITIVITY
RECOVERY