The effects of ionizing radiation and hyperthermia on mouse spinal cord

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:6167384

Lo, Yeh-Chi

The spinal cord (T{sub 9}-L{sub 5}) of C3Hf/Sed//Kam mice was irradiated with single or fractionated doses. Four arbitrary scales of neurological change were used. Findings for X were: (1) radiation induces progressive damage, from mild to serve. (2) The latency to damage depended on the dose and the level of damage. Following doses around the ED{sub 50}, the onset of paralysis occurred between 6 and 8 months. (3) For the NSD equation, the exponent for N was 0.36-0.33 for mild to severe paralysis. Comparisons of ED{sub 50s} for 2 fractions separated by various intervals showed no time effect until 30-60 days. (4) If the data for higher doses per fraction were excluded, the {alpha}/{beta} ratios were 3.5-5.6 for score 1-3. (5) Histological evidence of demyelination was evident at the time of paralysis. Using a water bath, the spinal cord was heated at 42.0 to 43.0{degree}C for 10-100 min. The results were: (1) Hyperthermia produces an acute reversible damage in the surviving mice. (2) No detectable late effects were seen up to 1.5 years. (3) A value of 0.48 for R in thermal dose equation was found. (4) Heat lesions included neuronal and vascular damage, but this was only at high thermal dose.

• Research Organization: California Univ., Los Angeles, CA (USA)
• OSTI ID: 6167384
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
HYPERTHERMIA
RADIOSENSITIVITY EFFECTS
SPINAL CORD
BIOLOGICAL RADIATION EFFECTS
FRACTIONATED IRRADIATION
MICE
RADIATION DOSES
TEMPERATURE EFFECTS
ANIMALS
BIOLOGICAL EFFECTS
BODY TEMPERATURE
CENTRAL NERVOUS SYSTEM
DOSES
IRRADIATION
MAMMALS
NERVOUS SYSTEM
RADIATION EFFECTS
RODENTS
VERTEBRATES
560152* - Radiation Effects on Animals- Animals
560200 - Thermal Effects