ABSTRACT
AIM: To study the absorption and excretion of CT-707 in healthy male subjects. METHODS: Six healthy male subjects received a single 300 mg (120 μCi) oral dose of radio-labeled CT-707 as a suspension in a fasted state. Blood, urine and feces were collected. Radioactivity concentrations were measured by liquid scintillation counting (LSC). The pharmacokinetic parameters of total radioactivity in plasma were calculated by WinNonlin (Pharsight version 8.1) software according to the non-compartment model. The recovery rate of total radioactivity in urine and feces was calculated according to the weight and radioactivity concentration of urine and feces collected at each time interval. RESULTS: After a single 300 mg oral of radio-labeled CT-707 552 h (23 d) as a suspension in a fasted state, the mean AUC
ABSTRACT
RESUMO Uma revisão da determinação de alfa e beta total em água, usando espectrometria de cintilação em meio líquido, é apresentada. Foram identificados os principais fatores que influenciam a exatidão e a repetibilidade dos resultados analíticos: pré-concentração térmica, tipo de ácido, janela de contagem e padrão de calibração. Um procedimento analítico foi estabelecido e aplicado a amostras de água de abastecimento público do estado de Goiás para avaliação das radioatividades alfa e beta total. O resumo estatístico dos dados foi realizado por meio dos métodos de análise de dados censurados. Os resultados estão consistentes com os valores de referência do Ministério da Saúde.
ABSTRACT A review to determine the gross alpha and beta in water by using liquid scintillation spectrometry is presented. The main factors that influence the accuracy and repeatability of the analytical results are: thermal pre-concentration, acid type, counting window, and calibration standard. Accordingly, an analytical procedure was established and carried out to samples of the public water supplies in the state of Goiás, Brazil, to evaluate the gross alpha and beta radioactivities. The statistical summary of data was conducted by using analysis methods of censored data. The results comply with the guideline values from the Brazilian Department of Health.
ABSTRACT
Objective To design a new pre-treatment device and to evaluate its efficiency in order to monitor the tritium levels in biological samples.Methods The detection efficiency of tritium was determined with standard tritiated water.Recovery of tritiated water and organically bound tritium (OBT) were detected with high, medium and low activities of standard tritiated water and 3H-TdR (tritiated thymidine), respectively.Comparison of three kinds of biological samples using different pre-treatment devices was shown.Results The standard curve can be used in environmental tritium measurement and the detection efficiency for tritium was 23.3%.When 40.0 g rice with standard HTO or 3H-TdR was pretreated with this device, the average recovery of HTO and OBT was about 95.4% , which showed good reproducibility.The comparison results were similar.Conclusions The pre-treatment device can be used to survey the OBT in environmental biological samples.
ABSTRACT
The uptake and retention of ~3H-HPD in.human malignant cells(cell line MGC 80-3,SGC-7901,BEL-7402,Os-732,Detroit-6 and HeLa)and normal fibroblasts were studied by liquid scintillation counting method.The order of cell lines which took up ~3H-HPD after 30 min.incubation were fibroblasts,HeLa, BEL-7402,Detroit-6,SGC-7901,MGC 80-3 and Os-732 respectively according to the amount of ~3H-HPD in cells.Due to the variety in the amount of excretion, however,those cells which retained ~3H-HPD after 24 hours cultivation were Os-732, Detroit-6, BEL-7402,HeLa,SGC-7901,MGC 80-3 and fibroblasts respectively in respect to the ~3H-HPD level in cells.The uptake was reduced by raising extracel- lular pH and lowering temperature as well as adding higher concentration of serum. Our results showed that the ~3H-HPD content in malignant ceils was higher than those in normal ones and it was because that malignant cells retained ~3H-HPD longer other than took up more