细胞功能测定

The opioid and 6-acetylmorphine assays utilize gas chromatography-mass spectrometry (GC-MS) for the analysis of morphine, codeine, hydromorphone, hydrocodone, and 6-acetylmorphine in blood and urine. The specimens are fortified with deuterated internal standard and a five- ...

Analysis of clinically relevant amino acids using ion-exchange chromatography coupled to photometric detection has been an indispensable component in the detection of inborn errors of metabolism for six decades. Detection of amino acids using mass spectrometry offers advanta ...

Opiates and opioids currently rank among the most commonly prescribed pain medications. We describe two liquid chromatography tandem mass spectrometry (LC-MS-MS) methods for the quantification of morphine, codeine, hydrocodone, hydromorphone, oxycodone, oxymorphone, and ...

Urine organic acid analysis is an essential component of the workup of the patient suspected to have an inborn error of metabolism (IEM). Urine contains several hundred different organic acids, which arise from a multitude of different sources including both normal and abnormal metaboli ...

The measurement of urinary orotic acid excretion is an important test for establishing a diagnosis of hereditary orotic aciduria, a genetic defect of pyrimidine biosynthesis. Measurement of secondary urinary orotic acid elevation is also an important clinical test for the differen ...

A patient suspected of an inborn error of metabolism will commonly have urine organic acid analysis performed as part of their workup. The traditional urine organic acid method involves extraction of the acidic fraction from urine samples using an organic solvent, derivatization of extr ...

Phencyclidine (PCP) is a cycloalkylamine and is classified as a dissociative anesthetic. In the1950s, PCP was tested as an intravenous anesthetic but due to its severe side effects, it was withdrawn from the clinical use. Since then PCP has become an illegal street drug making its laboratory ana ...

Oxycodone is a semisynthetic opioid analgesic used in pain management. In the following method, gas chromatography-mass spectrometry (GC-MS) is used to determine the presence and concentration of the drug in blood and urine. The specimens are fortified with deuterated internal stand ...

A multiple reaction monitoring positive ion HPLC method with tandem mass spectrometric detection (MS-MS) for determination of sirolimus in human blood samples is described. This method utilizes an online cleanup step that provides simple and rapid sample preparation with a switchi ...

Membrane proteins (MPs) are responsible for the interface between the exterior and the interior of the cell. These proteins are involved in numerous diseases, like cancer, cystic fibrosis, epilepsy, hyperinsulinism, heart failure, hypertension and Alzheimer disease. However, stu ...

As the equivalent to gatekeepers of the cell, membrane transport proteins perform a variety of critical functions. Progress on the functional and structural characterization of membrane proteins is slowed due to problems associated with their (heterologous) overexpression. Of ...

Integral membrane proteins, in particular receptors, regulate numerous physiological functions. The primary difficulty presented by their study in vitro is to obtain them in sufficient amounts in a functional state. Escherichia coli is a host of choice for producing recombinant pro ...

Structural biology of membrane proteins is often limited by the first steps in obtaining sufficient yields of proteins because native sources are seldom. Heterologous systems like bacteria are then commonly employed for membrane protein over-expression. Escherichia coli is the m ...

Due to their implication in numerous diseases like cancer, cystic fibrosis, epilepsy, hyperinsulinism, heart failure, hypertension, and Alzheimer disease, membrane proteins (MPs) represent around 50% of drug targets. However, only 204 crystal structures of MPs have been solved. Str ...

Membrane proteins play key roles in cellular physiology, and they are important drug targets. Approximately 25% of all genes identified in sequenced genomes are known to encode membrane proteins; however, the majority have no assigned function. Although the resolution of soluble prote ...

In the process of selecting an appropriate host for the heterologous expression of functional eukaryotic membrane proteins, Drosophila S2 cells, although not yet fully explored, appear as a valuable alternative to mammalian cell lines or other virus-infected insect cell systems. Th ...

A system of expression of mammalian membrane proteins in baculovirus-infected insect cells is described, allowing analytical or preparative production in the milligram range of such type of proteins. This is illustrated by the setup of the expression system of the human breast cancer re ...

Eukaryotic membrane proteins are often difficult to obtain in sufficient amounts for structural studies using classical cell culture overexpression systems. This could be due to incomplete protein maturation and insufficient trafficking to the plasma membrane or to a cytotoxic ...

Past literature on exposure to lipophilic agents such as organochlorines (OCs) is conflicting, posing challenges for the interpretation of their potential human health risks. Since blood is often used as a proxy for adipose tissue, it is necessary to model serum lipids when assessing health ...

Owing to their importance in cellular physiology and pathology as well as to recent technological advances, the study of lipids has reemerged as a major research target. However, the structural diversity of lipids presents a number of analytical and informatics challenges. The field of lip ...