Puncture accuracy of an optical tracked robotic aiming device-a phantom study.

Objectives: To evaluate the targeting accuracy of stereotactic punctures based on a hybrid robotic device in combination with optical tracking-a phantom study.

Methods: CT data sets of a gelatin-filled plexiglass phantom with 1-, 3-, and 5-mm slice thickness were acquired. An optical navigation device served for planning of a total of 150 needle trajectories.

[Effect of levonorgestrel and ethinyl estradiol and their combination on biotransformation reactions].

Caffeine is mainly metabolized by 3-methylcholanthreneinducible cytochrome P-450, whereas metamizol (Analgin) is probably mainly metabolized by the phenobarbital inducible cytochrome P-450 family. Therefore the elimination of caffeine from serum and the elimination of the main metabolites of metamizol in urine reflect the activity of these two cytochrome P-450 families. Sex hormones can influence the activity of cytochrome P-450.