Cytoprotection is defined as an ability of pharmacologic agents, originally PGs, to prevent gastric and intestinal mucosal injury produced by a variety of ulcerogenic agents (eg, aspirin, indomethacin, bile acids) and by necrotizing agents (eg, boiling water, absolute alcohol, 0.6 mol/L HCl, 0.2 mol/L NaOH).
Definition of systematic error. : an error that is not determined by chance but is introduced by an inaccuracy (as of observation or measurement) inherent in the system.
Sometime the measuring instrument itself is faulty, which leads to a systematic error. For example, if your stopwatch shows 100 seconds for an actual time of 99 seconds, everything you measure with this stopwatch will be dilated, and a systematic error is induced in your measurements.