Measured subject's weight was used to estimate the isotope dosing requirements.
This allows much smaller isotope doses to be used, allowing the isotope to act like a true tracer (28).
Body composition for isotope dosing was assessed using a Xitron Hydra multiple-frequency bioelectrical impedance analyser (Xitron Technologies, San Diego, California, USA) as previously described (Hannan et al, 1995).
Methods using C combined with GC-CIRMS are more sensitive than deuterium or C on gas chromatography mass spectrometry, allowing for smaller isotope doses to give an adequate analytic signal (1 compared with 17.5 μmol) (28).
It is questionable if this limitation is justified, especially when looking at the effect of the (type of) isotope, the dose calibrator type/manufacturer and the geometry of the radioactive sample.
Consistencies were related to: isotope use and doses of radioactivity, number of animals per time point, exsanguination of animals, freezing methods, section thickness, tissue collection lists, section lyophilization, imaging technology, blood and calibration standards, tissues and sections sampled for quantitation, use of QWBA data for human dosimetry, and QWBA method validation.
Intestinal permeability was investigated in age-matched gluten-sensitive and control macaques by using mass spectrometry to detect and quantify an orally dosed, isotope labeled 33-mer gluten peptide delivered across the intestinal epithelium to the plasma.
Consideration of the health effects of Chernobyl must take into account both tissue-specific doses due to isotope concentration and whole-body doses.
However, because the second dose of isotope was ingested prior to complete exhaustion of the first bolus of isotope, the response observed at 60 minutes is amplified due to the additional isotope to the already existing supply.
