Authors:Genquan Yan, Lu Yu, Xu Chen, Triet Tran, Lam Nguyen, Zhijun Wang and Ling Wang
-lives) in the previous study [ 19 ], the result may not be reliable. In our study, the duration of sampling was extended to 48 h, which covered more than 5 half-lives to include the entire elimination phase. The urineexcretion data were also collected which
Authors:S. Ridone, D. Arginelli, E. Inglese, A. Lucca, R. Matheoud, A. Miranti, M. Montalto, C. Peroni, M. Rudoni, C. Secco, S. Vallegiani and L. Vigna
The radiopharmaceutical [153Sm]Sm-EDTMP is administered for painful bone metastases with the standard dosage of 37 MBq/kg, without evaluation of patient
individual characteristics. For a better dose estimate in vivo stability should be considered, because labelled and unlabelled
samarium do not have the same metabolic pathway. We evaluated radiopharmaceutical in vitro stability, measuring the activity
by beta and gamma spectrometry. Subsequently we verified in vivo stability on serial blood and urine samples. The percentage
of the unlabelled radiopharmaceutical is high and, on the basis of radiochemical data as well as blood clearance and urine
excretion, we calculated the main parameters for a preliminary biokinetic model.
This study determined trimethylselenonium ion [TMSe, (CH3)3Se+] and total organic selenium cationic species urinary excretion values for healthy human subjects and Sprague-Dawley rats fed regular diets. The only source of TMSe was from the endogenous selenium body pool. Total selenium concentration, in urine was determined by instrumental neutron activation analysis. TMSe and total selenium cationic species concentrations and percent of total selenium urine excretion were determined by chemical neutron activation analysis and coupled anion-cation exchange chromatography and anion-exchange chromatography, respectively. Within experimental error, mean values for TMSe and cationic species as percent selenium were comparable for both human subjects and Sprague-Dawley rats. This study suggested that TMSe excreted in urine by healthy human subjects and Sprague-Dawley rats fed a normal diet is not a minor but a general metabolite of selenium ingested in a normal diet.
Authors:B. Le Guen, L. Exmelin, P. Berard, J. Malarbet and P. Royer
It is important that in radioiodine dosimetry for low levels of daily intake, allowance must be made for the normal daily intake of stable iodine. This intake varies from one region to another, and variations are observed from one person to the next within a region, depending on eating habits. Measuring iodine in the urine over 24 hours can indirectly assess these variations. Analysis of the total iodine in the urine was carried out for 69 French people living in a temperate maritime region or in mainland France. This study justifies individual assessment of the coefficient of iodine transfer to the thyroid by means of this survey based on the urinary iodine analysis. The consequences for man of the release of 129I around a nuclear reprocessing plant were analyzed by applying the methodology published previously by the authors. A software program based on the iodine biokinetic model recommended by the ICRP was used to calculate the daily urine excretion of 129I for five different diets of total iodide in a ratio of 10-4 for 129I/127I. This model makes it possible to set a practical detection limit of 20 mBq (0.003 µg). This approach is important from a practical point of view for health physicists involved in routine monitoring of workers in the nuclear field and members of the public exposed to radioiodine released into the environment.
Authors:H. Machulla, K. Dutschka, D. Van Beuningen and T. Chen
Radioiodinated ω-phenylfatty acids were recently proposed as radiopharmaceuticals for determining myocardial metabolic alterations.
Therefore uptake and elimination of different radiohalogenated phenylfatty acids were determined in blood and heart muscle
of mice. The structure activity dependence i.e. the effect of length of the carbon chain, position of the substituent at the
benzene ring and type of radiohalogen was studied. Highest myocardial accumulation was found in case of a phenylfatty acid
with 15 carbon atoms in the alkylgroup and the radiohalogen attached to the benzene ring in the para position. No difference
was observed between the radiobrominated and radioiodinated substrates. In contrast to aliphatic radioiodinated fatty acids,
the radioactivity in the stomach remained almost constant (i.e. below 1% dose/organ). Thus 15-(123I-phenyl)-pentadecanoic acid (IPPA) could be brought into clinical application with success. Blood clearance and urine excretion
of the radioactivity were determined and the results found to agree with the expectations based on the principal metabolic
path of phenylfatty acids.
Authors:Changmin Shao, Jian Zheng, Junjie Chi, Lijia Jing, Xiufeng Yan and Yang Wang
– 15 ]. Until now, the excretion profile of MCPT and its metabolite HCPT has not been assessed. In the present study, we therefore examined the bile, feces, and urineexcretion of MCPT and HCPT in rats after i.v. administered MCPT using a simple