Cytochrome P450 (CYP) enzymes are responsible for the metabolism of numerous xenobiotics and endogenous compounds, including the metabolic activation of most environmental toxic chemicals and carcinogens. Both metabolic and genetic polymorphisms have been identified for human CYP enzymes. The association of CYP genetic polymorphism and human cancer risk, and susceptibility to environmental haza...

The ability to interact with children and young people (CYP), appropriately examine and competently interpret signs is an essential skill for many medical practitioners and allied healthcare professionals; yet, how do we ensure competence in our students and trainees? One method is to include CYP in both formative and summative assessments; this provides an invaluable opportunity for examiners ...

BACKGROUND Fish is a frequent elicitor of severe IgE-mediated allergic reactions. Beside avoidance, there is currently no allergen-specific therapy available. Hypoallergenic variants of the major fish allergen, parvalbumin, for specific immunotherapy based on mutation of the 2 calcium-binding sites have been developed. OBJECTIVES This study sought to establish a mouse model of fish allergy re...

Metabolism of arachidonic acid by cytochrome P450 (CYP) to biologically active eicosanoids has been recognized increasingly as an integral mediator in the pathogenesis of cardiovascular and metabolic disease. CYP epoxygenase-derived epoxyeicosatrienoic and dihydroxyeicosatrienoic acids (EET + DHET) and CYP ω-hydroxylase-derived 20-hydroxyeicosatetraenoic acid (20-HETE) exhibit divergent effects...

Previous studies have shown that several protein kinase inhibitors are time-dependent inhibitors of cytochrome P450 (CYP) 3A. We screened 14 kinase inhibitors for time-dependent inhibition of CYP2C8 and CYP3A. Amodiaquine N-deethylation and midazolam 19-hydroxylation were used as marker reactions for CYP2C8 and CYP3A activity, respectively. A screening, IC50 shift, and mechanismbased inhibition...

Diltiazem (DTZ) N-demethylation occurs by cytochrome P-450 (CYP) 3A based on the following observations: 1) a single enzyme Michaelis-Menten model of metabolite formation, 2) high correlations of DTZ N-demethylation activity to other CYP3A activities, 3) inhibition of DTZ N-demethylation activity by triacetyloleandomycin, and 4) DTZ N-demethylation activity by expressed CYP3A enzymes only. The ...

BACKGROUND One commonly used approach for reporting family planning service levels is to calculate the couple-years of protection (CYP) provided by a program. CYP refers to “the estimated protection provided by contraceptive methods during a one-year period based upon the volume of all contraceptives sold or distributed free of charge to clients during that period.... The term ‘CYP’ reflects di...

Introduction The cytochromes P450 (CYP) are oxidative enzymes involved in multiple biochemical pathways, including drug metabolism and clearance of toxicants from the body [1]. Certain drugs or chemicals can inhibit CYP enzyme function, which alters their ability to metabolize drugs. The resulting toxic effects are referred to as drug-drug interactions and are a major concern for drug developme...

Previous studies have shown that several protein kinase inhibitors are time-dependent inhibitors of cytochrome P450 (CYP) 3A. We screened 14 kinase inhibitors for time-dependent inhibition of CYP2C8 and CYP3A. Amodiaquine N-deethylation and midazolam 1'-hydroxylation were used as marker reactions for CYP2C8 and CYP3A activity, respectively. A screening, IC50 shift, and mechanism-based inhibitio...

Many of the enzymes involved in xenobiotic metabolism are maintained at a low basal level and are only synthesized in response to activation of upstream sensor/effector proteins. This induction can have implications in a variety of contexts, particularly during the study of the pharmacokinetics, pharmacodynamics, and drug-drug interaction profile of a candidate therapeutic compound. Previously,...