Showing results 1089 - 1104 of 91813 for .
Showing results 1089 - 1104 of 91813 for .
Screening and Identification of Adulterants in Male Enhancement Supplements Using Liquid Chromatography with High-Resolution Mass Spectrometry
Food Integrity 2016 -- The increased availability of dietary supplements in the market and popularity among consumers have been accompanied by an increased frequency of adulteration of these products with synthetic pharmaceuticals. Phosphodiesterase type 5 (PDE5) inhibitors represent an important group of adulterants that have been used to develop or intensify the desired biological effect in dietary supplements advertised for male sexual performance enhancement.
Screening of Phosphodiesterase Type 5 Inhibitors in Dietary Supplements Using Liquid Chromatography/Quadrupole-Orbital Ion Trap Mass Spectrometry
HPLC 2016 Conference -- The increased availability of dietary supplements in the market and popularity among consumers have been accompanied by an increased frequency of adulteration of these products with synthetic pharmaceuticals. Phosphodiesterase type 5 (PDE5) inhibitors represent an important group of adulterants that have been used to develop or intensify the desired biological effect in dietary supplements advertised for male sexual performance enhancement. Therefore, reliable...
Comparison of Procedures Used to Separate the Different Layers of Human Skin Biopsy Samples
DMDG 2016 -- Reliable techniques for separating the different layers in human skin are not widely available. The aim of this work was to develop an appropriate methodology for separating the different layers of human skin biopsy samples (dermis and epidermis) to enable quantification of concentrations of test material within each layer. In order to achieve this, the use of two different techniques (cryosectioning and heat separation) was assessed in order to separate the different layers of...
Development of a CLL-MRD Staining Protocol Without the Use of Tandem Dyes and Comparison with the ERIC 6-Color Protocol
30th Congress of the International Society for Advancement of Cytometry, CYTO 2015
Challenges Developing Sensitive Quantitative Assays for Cyclophosphamide and 4-Hydroxycyclophosphamide in Human Plasma using HPLC-MS/MS
ASMS 2017 -- Cyclophosphamide (CP) is widely used as antitumor agent to slow/stop cell growth and improve immune response to various diseases; however, this process requires the activation of the metabolite 4-hydroxycyclophosphamide (4-OH-CP). 4-OH-CP is unstable in plasma due to its ultimate conversion to the cytotoxic metabolite phosphoramide mustard. Semicarbazide (SCZ) can stabilize 4-OH-CP by terminating this conversion. An assay for both CP and 4-OH-CP using SCZ has been previously...
The Challenges of Quantification of DMG-PEG (GM-020) in Mouse Plasma by HPLC-MS/MS
ASMS 2017 -- By forming liposomes or nanoparticles, lipids are widely used as carriers for delivery of therapeutic molecules. DMG-PEG GM-020 is a commercial available pegylated lipid gaining worldwide interest as a drug delivery system polymer molecule due to its functional group which helps it fuse with the drug. As we know, there is no published LC-MS/MS quantitative assay for GM-020 in mouse plasma. Here, we report a fast, robust and high-throughput assay for the quantification of GM-020...
Two Quantitative Assays for the Phosphorodiamidate Morpholino Oligomer (PMO) SRP-4045 in Mouse Plasma Using HPLC-MS/MS Coupled with Solid Phase Micro-Extraction
ASMS 2017 -- Phosphorodiamidate morpholino oligomers (PMO) are among the most advanced antisense therapeutics and a promising strategy for treating genetic disorders and infections. We have previously published two LC-MS/MS quantitative assays for positively charged PMOs (PMOplus) in human plasma and urine. SRP-4045 differs from PMOplus in that it is a neutral PMO containing 22 bases with a molecular weight >7500 Da, and is currently in development for patients with Duchenne Muscular...
Quantitative Analysis of Oligonucleotides Using Liquid Chromatography Coupled with High-Resolution/Accurate Mass (HR/AM) Mass Spectrometry
AAPS-NBC 2016 - Oligonucleotide therapeutics have experienced tremendous growth in the past decade, with revenues expected to exceed $1.2B by 2020. However, one unexpected hurdle for such rapid growth has proven to be the development of sensitive and selective bioanalysis methods for such compounds.
When Words Collide: Use of the Term 'Selection Bias' in Observational Comparative Drug Safety and Effectiveness Research
ISPOR 2017 -- In the epidemiologic methods literature, the term 'selection bias' is typically used to describe collider-stratification bias. Yet, many investigators who conduct comparative drug safety and effectiveness research use the term inconsistently when describing other phenomena that lead to bias in, or lack of generalizability of, observational research findings. We set out to survey the past five years of comparative drug safety and effectiveness literature and enumerate the...
Simultaneous Analysis of Morphine, Morphine-6-Glucuronide and Morphine-3-Glucuronide in Human Plasma Using Liquid Chromatography Coupled with Tandem Mass Spectrometry
AAPS 2015 - The aims of this study were to develop and validate a method for the accurate and consistent quantitation of morphine, M3G and M6G content in human plasma, with particular emphasis on the potential problem associated with matrix interference, separation and peak shape degradation; thus making the method suitable for pharmacokinetic studies and forensic analysis.
Assessing Hemolysis Failures for LC-MS/MS Assays Using LC-HRAM on a Q-Exactive™ Mass Spectrometer
Development and Validation of an LC-MS/MS Method for Plasma Analysis of the Serotonin Metabolite: 5-Hydroxyindoleacetic acid (5-HIAA)
AAPS 2014 - Serotonin (5-HT) plays a critical role in regulating several major physiological processes of the gastrointestinal (GI) tract, including aspects of secretion, motility, inflammation and sensation...