细胞技术

Cocaine, a stimulant, is a commonly abused drug. Cocaine and its metabolites are measured in various biological specimens for clinical and forensic purposes. Urine or plasma or serum is spiked with deuterated internal standards cocaine-d3, benzoylecgonine-d3, ecgonine methyl este ...

The simultaneous determination and quantification of cocaine and its major metabolite, benzoylecgonine, in meconium using UPLC-MS/MS is described. Ultra-performance liquid chromatography (UPLC) is an emerging analytical technique which draws upon the principles of chro ...

Creatine metabolism disorders include a creatine transporter deficiency, as well as, deficiencies of two enzymes involved in creatine synthesis, arginine–glycine amidinotransferase (AGAT) and guanidinoacetate methyltransferase (GAMT). Laboratory diagnosis of th ...

A liquid–liquid extraction (LLE) of drugs and internal standard (promazine) is performed by mixing urine at basic pH with 1-chlorobutane. There are no hydrolysis or derivatization steps. After centrifugation the organic (upper) layer is transferred to another tube and evaporated. The d ...

Centrifuged urine, internal standard (promazine), and ammonium formate buffer are mixed in an autosampler vial to achieve a 10-fold dilution of the specimen. Without additional pretreatment, 10 �L of the sample is injected onto a C18 reverse phase column for gradient analysis with ammonium ...

Clinical laboratories around the world are recognizing the power of mass spectrometry. This technique, especially when coupled to gas chromatography or liquid chromatography, is revolutionizing the analysis of many analytes. Unlike many other techniques which measure one anal ...

Measurement of low concentrations of estrogens, encountered in pre-pubertal children, men, and postmenopausal women, is important for numerous clinical applications. We describe a method for high sensitivity analysis of estrogens that uses two-dimensional chromatograph ...

The mitochondrial fatty acid β-oxidation is integral to normal cellular metabolism and maintenance of cellular energy supplies. Disorders of this pathway interrupt the body’s ability to deal with fasting states, as well as compromising the functioning of organs and systems whose high ...

A detailed protocol using liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS) is described for the determination of the total homocysteine (HCY) in plasma. Sample preparation is simple and relies on the complete reduction of any homocystine ((HCY)2) or protein-bound ...

Fentanyl is a potent, short-acting synthetic opioid analgesic. Fentanyl is measured in blood and urine following mixed-mode solid phase extraction. The specimens are fortified with deuterated internal standard and a five-point calibration curve is constructed. The final extrac ...

Neuroblastoma, in most cases, is characterized by increased production of catecholamines and their metabolites. Laboratory diagnosis and clinical follow-up include the measurement of urinary homovanillic acid (HVA) and vanillylmandelic acid (VMA). In the following proced ...

Hydroxyurea is an antineoplastic drug, which is also widely used in the treatment of sickle cell disease. Various methods including colorimetry, high performance liquid chromatography, and gas chromatography-mass spectrometry (GC-MS) are available for the assay of hydroxyurea. ...

Most (90%) cases of congenital adrenal hyperplasia (CAH) are due to mutations in the steroid 21-hydroxylase gene (Cyp21). CAH due to 21-hydroxylase deficiency is diagnosed by confirming elevations of 17-hydroxyprogesterone (OHPG) and androstenedione (ANST) with decreased corti ...

Ibuprofen is a non-narcotic, non-steroidal anti-inflammatory drug used for the treatment of pain, fever, and inflammatory diseases such as rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis. It is also used for induction of closure of patent ductus arteriosus (PDA) in ...

Indomethacin is a non-narcotic and non-steroidal anti-inflammatory drug used in the treatment of various inflammatory diseases such as rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis. In neonates, it is also used for induction of closure of patent ductus arter ...

The following chapter describes a method to measure iothalamate in plasma and urine samples using high performance liquid chromatography combined with electrospray positive ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Methanol and water are spiked with the intern ...

Acylcarnitine analysis using tandem mass spectrometry has become a powerful tool in the investigation of pediatric patients presenting with clinical signs and symptoms suggestive of fatty acid oxidation defects. These signs are diverse and include failure to thrive, feeding diff ...

Ketamine hydrochloride, a Schedule III drug under the Controlled Substances Act, is a dissociative anesthetic that has a combination of stimulant, depressant, hallucinogenic, and analgesic properties. This procedure utilizes solid phase extraction of blood, tissue, or urine sam ...

The potential for adverse effects of lead (Pb) exposure on development in children remains a health concern in the U.S., and programmatic screening of children for elevated blood lead levels ( 10μg/dL) is widespread. With sufficiently sensitive technology for the measurement of lead such as I ...

Deficiencies in any of the 50 degradative enzymes found in lysosomes results in the accumulation of undegraded material and subsequently cellular dysfunction. Early identification of deficiencies before irreversible organ and tissue damages occur leads to better clinical ou ...