Pregledni rad
Internal contamination with medically significant radionuclides
A. Duraković
; Odjel za nuklearne znanosti, Istraživački institut, Sveučilište za medicinske znanosti SAD-a, Medicinski fakultet F. Edwarda Herberta, Bethesda, Maryland, SAD
Sažetak
The increased use of radioactive isotopes in industry, science, and medicine and the potential contamination of the biosphere with the products of nuclear fission from radioactive fallout following use of nuclear weapons are of concern to the medical profession. The hazards of incorporated radionuclides in their target organs include tissue damage by ionizing radiation and malignant changes at the retention sites. This article provides guidelines for understanding the mechanisms and the management of internal contamination with medically significant radionuclides. Among over 400 radioactive isotopes released in the biosphere by a nuclear weapons explosion, 40 are of a potential hazard for man. Their organospecificity, long physical and biological half-life, and pathological and clinical changes in the organs of their incorporation are of immediate concern of preventive and clinical medicine. Relevant aspects of the physical and metabolic properties of different radionuclides are considered. They include the routes of their entry in the body, their metabolic properties, and routes of elimination. Also considered are ingestion and gastrointestinal absorption, inhalation and transalveolar entry into the bloodstream, percutaneous absorption and entry through the contaminated wounds, and direct entry of the radionuclides into the bloodstream by injection in cases of radionuclide misadministration. Prevention of gastrointestinal absorption is presented together with the therapeutic regimens for gastrointestinal elimination by gastric lavage, use of emetic and laxative drugs, and administration on ion-exchange agents. Mobilization from the respiratory tract, particularly in cases of actinide contamination includes aerosols, chelating agents, and lung lavage, among other therapeutic modalities. Removal of the radionuclides already in the bloodstream and extracellular fluid is facilitated by isotope dilution therapy, use of blocking agents, hormonal, and diuretic agents, and displacement therapy. Elimination of radionuclides from the sites of their retention in organs is discussed by the review of currently available complexing agents, including diethylene triamine pentaacetic acid (DTPA), dimercaptopropanol (BAL), deferoxamine (DFOA), and new lipophilic agents for action in the intracellular environment, including lipophilic derivatives of paraaminocarboxillic acid (PACA), liposomes, sulfonated tetrameric catecholamides (MICAMS), synthetic catecholamide chelators, and natural chelates isolated from cultures of various microorganisms. Their efficacy in the treatment of internal contamination is yet to be determined in experimental and clinical trials.
Ključne riječi
Hrčak ID:
153970
URI
Datum izdavanja:
23.12.1986.
Posjeta: 1.039 *