The effects of ionizing radiation and hyperthermia on mouse spinal cord

Thesis/Dissertation · Sun Jan 01 04:00:00 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
• Country of Publication: United States
• Language: English

Related Subjects

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