1. Stable isotope methods are being used to investigate the absorption of dietary iron. In order to be certain that this new methodology is accurate, we have compared results obtained using stable isotopes and inductively coupled plasma mass spectrometry with those determined using a radioisotope and whole body counting. 2. The stable isotope 54Fe (2.8 mg) was given to 10 healthy non-pregnant w...

neuroendocrine tumors (nets) constitute a heterogeneous group of neoplasms including carcinoids, pancreatic neuroendocrine tumors, pituitary tumors, medullary thyroid carcinoma and phaeochromocytomas. the symptoms and the outcome of nets differ considerably between patients depending on several factors. by labelling tracers with a radioisotope, the tracer acts as a carrier to deliver the radioa...

After intravenous injection of S-adenosyl-L-homocysteine3H (homocysteine-labeled) into rats, less than 15% of the radioisotope was incorporated into protein methionine or excreted in the urine as oc-ketobutyrate. The remaining radioisotope was found associated with an unknown keto acid excreted in the urine. Intravenous injection of Sadenosyl-L-homocysteine-35S or S-adenosyl-3H-L-homocysteine (...