OBJECTIVE To characterize the absorption, distribution, metabolism, and excretion of naloxegol, a PEGylated derivative of the µ-opioid antagonist naloxone, in healthy male subjects. MATERIALS AND METHODS [14C]-Labeled naloxegol (27 mg, 3.43 MBq) was administered as an oral solution to 6 fasted subjects. Blood, fecal, and urine samples were collected predose and at various intervals postdose. ...

We compared the effect of nine N-nitroso compounds, given by gavage to adult rats, on specific radioactivity of the trichloroacetic acid-precipitable liver proteins, 1 hr after the injection of [14C]leucine. The specific radioactivity was decreased by dimethylnitrosamine, diethylnitrosamine, methyl-n-butylnitrosamine, and nitrosomorpholine 5 to 10 hr after their administration; was increased by...

The specific radioactivity of [3H]Leu in the extracellular, intracellular, and Leu-tRNA pools of normal (white leghorn) and dystrophic (line 307) embryonic chick breast muscle cultures was analyzed as a function of equilibration time and extracellular Leu concentration (0.05-5 mM). The primary results were the following 1) [3H]Leu equilibrated to a constant specific radioactivity in the intrace...

UNLABELLED The accurate quantification of brain radioactivity concentration is limited by the spatial resolution of the PET scanner for structures smaller than 2-3 times the resolution. In the presence of enlarged cerebrospinal fluid spaces or regions of cortical neuronal loss, a significant underestimation of gray-matter radioactivity concentration due to the resulting partial-volume averaging...

Background: Some Particular areas contain natural radionuclide at levels much higher than those usually present in earth's crust. The radiological impact of the use of zirconium ore in zirconium industry is due to internal exposure of the lung by alpha particles and external exposure of the body by the gamma rays. The result of gamma spectrometry measurement of the concentrations of th...

Incorporation of selected amino acids by resting cells was studied with regard to effects of concentration, rate and extent of incorporation, cellular distribution, effect of ammonium ion on uptake, and competitive effects. l-Aspartic acid, l-alanine, l-serine, and glycine presented at trace levels were incorporated at rates ranging from 0.11 to 8.2 mumumoles per mg (dry weight) per minute, and...

Sunitinib is an oral multitargeted tyrosine kinase inhibitor approved for the treatment of advanced renal cell carcinoma, imatinibrefractory gastrointestinal stromal tumor, and advanced pancreatic neuroendocrine tumors. The current studies were conducted to characterize the pharmacokinetics, distribution, and metabolism of sunitinib after intravenous and/or oral administrations of [C]sunitinib ...