LATENT DAMAGE BY X-RAYS TO DNA IN THE VITULAR THYMUS

Journal Article · Mon Jan 01 04:00:00 EST 1962 · Shang-hai-shih K'o Hsueh Chi Shu Lun Wen Hsuan Chi, 1960

OSTI ID:4127569

Li, T; Ching, P; Lu, H; Chien, H

Vitular thymus DNA solutions were prepared andd then irradiated at a dosage of 1000 r/min. Viscosity drop was due to the degradation of large molecules 2 hours after irradiation. The relation of DNA degradation to radiation dosage indicated the behavior of DNA in the natural state. At 76 deg C DNA molecules became unstable and latent dainage occurred in the structure. The ultraviolet absorption of DNA was unaffected after preservation of temperature at 76 deg C for 60 minutes. After irradiation and without temperature preservation, a slight increase in absorption was observed. A preservation of 76 deg C induced a remarkable increase in DNA ultraviolet absorption. Latent damage not only destroyed the H bond between the double helix molecules but also increased the unstability of H bonds. The failure of a large radiation dose to lower the viscosity in a great extent indicated that a protecting agent may be found in a DNA solution. The presence of a protecting agent enabled the DNA solution to withstand x radiation of 6 x 10/sup 4/ r without direct emergence of degradation. Latent damage may occur at a definite radiation dose. Investigation revealed that the protecting agent might be calcium citrate. Latent damage may be explained by: breaking of backbone chains on one side; part of H bonds destroyed; and increased unstability of residual H bonds. All three items show a parallel proportional relationship. (TCO)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-18-003552
• OSTI ID: 4127569
• Journal Information: Shang-hai-shih K'o Hsueh Chi Shu Lun Wen Hsuan Chi, 1960, Journal Name: Shang-hai-shih K'o Hsueh Chi Shu Lun Wen Hsuan Chi, 1960
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ABSORPTION
AGE
BIOLOGY AND MEDICINE
CALCIUM COMPOUNDS
CALVES
CATTLE
CITRIC ACID
DECOMPOSITION
DNA
NUCLEIC ACIDS
RADIATION DOSES
RADIATION EFFECTS
RADIATION PROTECTION
SOLUTIONS
TEMPERATURE
THYMUS
ULTRAVIOLET RADIATION
VISCOSITY
X RADIATION