RESUMO
Response to a large-scale radiological incident could require timely medical interventions to minimize radiation casualties. Proper medical care requires knowing the victim's radiation dose. When physical dosimetry is absent, radiation-specific chromosome aberration analysis can serve to estimate the absorbed dose in order to assist physicians in the medical management of radiation injuries. A mock exercise scenario was presented to six participating biodosimetry laboratories as one individual acutely exposed to Co under conditions suggesting whole-body exposure. The individual was not wearing a dosimeter and within 2-3 h of the incident began vomiting. The individual also had other medical symptoms indicating likelihood of a significant dose. Physicians managing the patient requested a dose estimate in order to develop a treatment plan. Participating laboratories in North and South America, Europe, and Asia were asked to evaluate more than 800 electronic images of metaphase cells from the patient to determine the dicentric yield and calculate a dose estimate with 95% confidence limits. All participants were blind to the physical dose until after submitting their estimates based on the dicentric chromosome assay (DCA). The exercise was successful since the mean biological dose estimate was 1.89 Gy whereas the actual physical dose was 2 Gy. This is well within the requirements for guidance of medical management. The exercise demonstrated that the most labor-intensive step in the entire process (visual evaluation of images) can be accelerated by taking advantage of world-wide expertise available on the Internet.
Assuntos
Bioensaio/métodos , Aberrações Cromossômicas/efeitos da radiação , Cromossomos Humanos/efeitos da radiação , Internet/estatística & dados numéricos , Laboratórios/normas , Incidentes com Feridos em Massa/prevenção & controle , Lesões por Radiação/diagnóstico , Células Cultivadas , Cromossomos Humanos/genética , Radioisótopos de Cobalto/efeitos adversos , Relação Dose-Resposta à Radiação , Humanos , Processamento de Imagem Assistida por Computador , Linfócitos/efeitos da radiação , Metáfase/efeitos da radiação , Lesões por Radiação/genética , Lesões por Radiação/prevenção & controle , Liberação Nociva de Radioativos/prevenção & controle , RadiometriaRESUMO
The use of Chelex resin for the synthesis of radioactive lead complexes has been explored. The process involved immobilization of 203Pb on the resin and subsequent elution of complexed lead by chelating agents. 203Pb complexes derived from meso- and racemic dimercaptosuccinic acid (meso-DMSA, rac-DMSA) were prepared and assessed for stability in vitro.