Publications by authors named "T Wirz"

Background: Refugees are at high risk for developing mental illnesses. Due to language and cultural barriers, there is need for specifically adapted therapeutic procedures for refugees in inpatient mental health care settings. Internet-based applications in refugee mother tongues have the potential to improve the outcomes of mental health care for this vulnerable population.

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Background: Studies evaluating the CNS penetration of a novel tyrosine kinase inhibitor, entrectinib, proved challenging, particularly due to discrepancies across earlier experiments regarding P-glycoprotein (P-gp) interaction and brain distribution. To address this question, we used a novel "apical efflux ratio" (AP-ER) model to assess P-gp interaction with entrectinib, crizotinib, and larotrectinib, and compared their brain-penetration properties.

Methods: AP-ER was designed to calculate P-gp interaction with the 3 drugs in vitro using P-gp-overexpressing cells.

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An acylated peptide with MW ~4.5 kDa was measured in samples from pharmacokinetic, toxicology and clinical studies using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Lower limits of quantitation of 2 ng/mL and 50 pg/mL were achieved for animal and human plasma, respectively.

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Background: Using dried blood spots (DBS) for quantitation of the antiviral drug oseltamivir (Tamiflu(®)), an ester prodrug, and its active metabolite oseltamivir carboxylate could provide ethical and logistic benefits. Hence, its feasibility was investigated using a previously developed column-switching LC-MS/MS method.

Results: Sensitivity, precision and accuracy in DBS were comparable to standard plasma assays.

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The synthetic peptide drug taspoglutide, developed for treatment of diabetes, must be quantified at low pg/mL levels in biological samples. This manuscript describes the improvement of a previous method, featuring orthogonal hydrophilic interaction to reversed-phase chromatography column switching and tandem mass spectrometric detection. Signal-to-noise ratio was enhanced and isobaric interferences were reduced by ultra-performance separation using a basic mobile phase in 'wrong-way-round' ionization mode and monitoring a selective fragment ion.

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