Toxic effects of radiation

Harley, N. H. (1996). Toxic effects of radiation and radioactive materials. In Cdsarett and Doull s To.xicology The Basit Saettce of Poisons (C. D. Klaassen, Ed.), pp- 77 VS00. McGravi -Hill, New York. 

Figure 32.9 Survival time and associated mode of death of selected mammals after whole-body doses of gamma radiation. (Modified from Hobbs, C.H. and R.O. McClellan. 1986. Toxic effects of radiation and radioactive materials. Pages 669-705 in C.D. Klaassen, M.O. Amdur, and J. Doull [eds.]. Casarett and Doull s Toxicology. Third Edition. Macmillan, New York United Nations Scientific Committee on the Effects of Atomic Radiation [UNSCEAR]. 1988. Sources, Effects and Risks of Ionizing Radiation. United Nations, New York. 647 pp.)...

Hobbs, C.H. and R.O. McClellan. 1986. Toxic effects of radiation and radioactive materials. Pages 669-705 in C.D. Klaassen, M.O. Amdur, and J. Doull (eds.). Casarett and Doull s Toxicology. Third Edition. Macmillan, New York. 

Dactinomycin increases the pnlmonary toxic effects of radiation by an estimated 30%, and rednces the radiation tolerance of the Inng by at least 20% (1). 

Hobbs CH, McClellan RO. Toxic effects of radiation and radioactive materials. In Klaassen CD, Amdur MO, Doull J, eds. Casarette and Doull s Toxicology The Basie Science of Poisons 3rd ed. New York MaeMillan Publishing, 1986 497-530. 

Particular attention has been focused on the toxic effects of aromatic hydrocarbons because these chemicals have proven highly carcinogenic to humans and marine life. Of greatest concern are the PAHs, which are toxic to the benthos at the ppb level. The most common compounds are shown in Figure 28.20 their structures are based on fused aromatic rings. These high-molecular-weight compoimds are very nonpolar and, hence, have low solubilities. Once in seawater, they tend to adsorb onto particles and become incorporated in the sediments. The toxicity of PAHs is enhanced by photochemical reaction with UV radiation. Photo-activated toxicity is especially problematic in shallow-water sediments, such as found in estuaries. 

The literature suggests that the toxic effects of Thorotrast are due to the alpha radiation effects of thorium and not to the chemical effects of thorium or of the colloid (Faber 1973 BEIR IV 1988 Taylor et al. 1986 Wesch et al. 1983). Wesch et al. (1983) injected Thorotrast enriched with thorium-230 into rats and found a linear relationship between radiation level and tumor incidence. At a constant radioactive level, an increase in the injected colloidal volume had little influence on the number of liver tumors, but resulted in a decrease in tumor appearance time and, therefore, a decrease in lifespan. The larger colloidal volume may result in a more diffuse organ dose and a less "hot spot" distribution. Injection of the nonradioactive colloid resulted in no appreciable incidence of liver tumors. It is not known whether the colloidal particles induce the liver tumors when given in... 

Many causes of acute spinal cord infarction (of arterial and venous origin) have been reported (Table 17.2). They include diseases of the aorta and aortic surgery, thromboembolic events and cartilaginous disc embolism, vasculitis, coagulopathy, radiation-induced vasculopathy, toxic effects of contrast medium, epidural anesthesia, periradicu-lar nerve root therapy with crystalline corticoids, decompression illness, shock or cardiac arrest, lumbar artery compression and other etiologies... 

Many free-radical scavengers (including dithiols and dithiocarbamates) have potential therapeutic usefulness as radioprotective agents. Copper complexes are known to be scavenging agents for the superoxide radical, which is believed to play a role in the induction of radiation damage. The toxic effects of superoxide are believed to lie in its ability to reduce metal ions, for example Cu(II) to Cu(I),... 

Radiation sensitizers are pharmacologic agents that increase the lethal effects of radiation when administered in concert with it. An ideal radiation sensitizer should augment the cytotoxicity of radiation applied to malignant loci but not engender enhanced killing of normal cells, operate via a mechanism that is active towards oxic and hypoxic cell regions, and have a low inherent in vivo toxicity. 

Sodium iodide I 131 is used for palliation in selected cases of thyroid carcinoma. The usual toxic effect is radiation sick-rzu. 

This text contains a series of reviews on the toxic effects of drugs and other compounds, viruses, radiation, and occupational hazards. A chapter on drugs of choice in pregnancy and a section on diagnosis of fetal malformations are included. An online version is available. 

It is universally accepted that ionizing and UV electromagnetic radiation induce toxic effects in man. It has been shown above that these toxic effects are exacerbated when irradiation is coupled with xenobiotic exposure. Conversely, the toxic effects of xenobiotic exposure are enhanced by simultaneous exposure to ionizing or UV radiation. 

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