H. H. M. de Keyzer

Learn More
Intracellular efflux pumps have been largely the research focus in multidrug-resistant (MDR) Gram-positive and Gram-negative microorganisms and parasites including cancers. However, drug efflux mechanisms other than pumps per se have been observed, supported by the effects of isomeric, non-antibiotic depressant (DPR), phenothiazines and thixenes, and(More)
s of posters A SIMPLE METHOD FOR THE ISOLATION OF PLANT VOLATILES T.A. van Beek and H. van Bokhoven Volatiles play an important biological role in both the animal and plant kingdom. Usually the concentration in which these mediators occur in air are too low for direct measurements by today's analytical techniques. Therefore the compounds have to be(More)
A novel method was designed involving the titration of alternating current titration in a cell where one electrode was shielded by a capillary enclosure restricting access to it by charge carriers. With this cell, charge transfer complex titration of several thiazines all with some antimicrobial properties was effected in acetonitrile, against the electron(More)
Drug resistance to chemotherapy is rapidly emerging. Resistance to one drug carries over resistance to unrelated anticancer drugs leading to multidrug resistance (MDR). A major factor of MDR is P-glycoprotein (P-gp) mediated ABC transport found in many eukaryotic cells. P-gp acts as a drug eMux pump. The mdr1 gene involved in P-gp 170 protein production is(More)
1. Electron charge transfer interactions of some phenothiazine derivatives with aminoglycoside antibiotics, beta-lactams and penicillin-related antibiotics and bilirubin were investigated with alternating current titrations. 2. Neither the beta-lactams nor penicillin-related drugs interacted. 3. However, the aminoglycoside antibiotics formed complexes with(More)