Method validation of multi-element panel in whole blood by inductively coupled plasma mass spectrometry (ICP-MS).

Background: Analytical methods to measure trace and toxic elements are essential to evaluate exposure and nutritional status. A ten-element panel was developed and validated for clinical testing in whole blood. Retrospective data analysis was conducted on patient samples performed at ARUP Laboratories.

Iatrogenic Cushing syndrome in 24-hour urine free cortisol measurement.

Cushing syndrome (CS) is caused by an excess of glucocorticoids that results in a variety of symptoms such as central obesity, moon facies, hirsutism, and reddish-purple stretch marks. Cortisol is the most potent endogenous glucocorticoid, and measuring the total amount excreted in the urine over a 24-hour period is useful to screen for CS caused by a tumor. However, most cases of CS are believed to be caused by exogenous glucocorticoids, such as prednisone and prednisolone, which are administered for anti-inflammatory and immunosuppressive treatments.

Retrospective analysis of metabolite patterns of clobazam and N-desmethylclobazam in human plasma by LC-MS/MS.

Introduction: Clobazam is a benzodiazepine drug, used to treat Lennox-Gastaut syndrome in patients aged 2 years and older.

Objective: To support patient care, our laboratory developed a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the quantification of clobazam (CLB) and its major active metabolite N-desmethylclobazam (N-CLB) in human plasma or serum samples.

Methods: The chromatographic separation was achieved with an Agilent Zorbax Eclipse Plus C-18 RRHD column with mobile phase consisting of 0.

LC-MS/MS Method for Measurement of Thiopurine Nucleotides (TN) in Erythrocytes and Association of TN Concentrations With TPMT Enzyme Activity.

Monitoring concentrations of thiopurine metabolites is used clinically to prevent adverse effects in patients on thiopurine drug therapy. We developed a LC-MS/MS method for the quantification of 6-thioguanine (6-TG) and 6-methylmercaptopurine (6-MMP) in red blood cells (RBCs). This method utilizes an automated cell washer for RBC separation from whole blood samples and washing of the separated RBCs.

Rapid and Accurate Differentiation of Complex Species by Liquid Chromatography-Ultra-High-Resolution Orbitrap™ Mass Spectrometry.

In this study, a Liquid Chromatography-Mass Spectrometry (LC-MS) method for the identification of clinically relevant () complex organisms is tested using a set of microbial Type strains. This methodology is based on profiling proteins derived from complex isolates. These protein profiles are then used as markers of species differentiation.

Accurate Identification of Closely Related Complex Species by High Resolution Tandem Mass Spectrometry.

Rapid and accurate differentiation of complex () species from other mycobacterium is essential for appropriate therapeutic management, timely intervention for infection control and initiation of appropriate health care measures. However, routine clinical characterization methods for () species remain both, time consuming and labor intensive. In the present study, an innovative liquid Chromatography-Mass Spectrometry method for the identification of clinically most relevant complex species is tested using a model set of mycobacterium strains.

Integrative subcellular proteomic analysis allows accurate prediction of human disease-causing genes.

Proteomic profiling on subcellular fractions provides invaluable information regarding both protein abundance and subcellular localization. When integrated with other data sets, it can greatly enhance our ability to predict gene function genome-wide. In this study, we performed a comprehensive proteomic analysis on the light-sensing compartment of photoreceptors called the outer segment (OS).

Proteomics analysis of the non-muscle myosin heavy chain IIa-enriched actin-myosin complex reveals multiple functions within the podocyte.

MYH9 encodes non-muscle myosin heavy chain IIA (NMMHCIIA), the predominant force-generating ATPase in non-muscle cells. Several lines of evidence implicate a role for MYH9 in podocytopathies. However, NMMHCIIA's function in podocytes remains unknown.

Proteomic analysis of coregulators bound to ERα on DNA and nucleosomes reveals coregulator dynamics.

Chromatin immunoprecipitation studies have mapped protein occupancies at many genomic loci. However, a detailed picture of the complexity of coregulators (CoRs) bound to a defined enhancer along with a transcription factor is missing. To address this, we used biotin-DNA pull-down assays coupled with mass spectrometry-immunoblotting to identify at least 17 CoRs from nuclear extracts bound to 17β-estradiol (E2)-liganded estrogen receptor-α on estrogen response elements (EREs).