we have developed a simple and precise paper chromatographic method for the determination of 4-hydroxy-3-methoxymandelic acid (vma) in urine. concentrations of vma in patients with neuroblastoma were increased in comparison to controls. the linearity was excellent in the concentration range tested. the within-assay coefficient of variation for control and patient urine was less than 2.2%. the r...

We used two methods of reversed-phase liquid chromatography with amperometric detection, one for assay of unconjugated norepinephrine, epinephrine, and dopamine in urine, the other for determination of unconjugated vanillylmandelic acid and homovanillic acid. The catecholamines were extracted from urine by passage through a weak-cation exchange resin, then through alumina. Vanillylmandelic acid...

OBJECTIVE To determine the feasibility of establishing a system of screening for neuroblastoma. DESIGN Prospective study of mass screening in four clearly defined geographical areas. SETTING Four health districts of the Northern region of England. SUBJECTS 20,829 babies aged 6 months, 92% of target population. INTERVENTIONS Collection of urine on filter paper for analysis of content of ...

We describe an improved method for the assay of urinary vanillylmandelic acid by "high-performance" liquid chromatography, with electrochemical detection. A 1-mL aliquot of urine is acidified and extracted with ethyl acetate, then the ethyl acetate extract is extracted with phosphate buffer, pH 8.5. An acidified aliquot of the phosphate extract is injected into a reversed-phase column and vanil...

Buchanania lanzan is a widely used plant with a long history of traditional medicinal use for the treatment of various diseases. The present study is aimed at evaluating the adaptogenic activity of the methanolic extract of Buchanania lanzan leaves using the swim endurance model in all groups under normal and stressed conditions. Urinary vanillylmandelic acid (VMA) and ascorbic acid were select...

Utuversity of Alberta Hospital, Edmonton 61, Alberta, Canada. For reprints, write D. J. C., Division of Clinical Chemistry, Department of Pathology, Vancouver General Hospital, Vancouver, B. C., Canada. ‘Nonstandard abbreviations used: not’, 4-desoxypyridoxine; pHPPA, p-hydroxyphenylpyruvic acid; PHPAA, p-hydroxyphenylacetic acid; pHyLA, p-hydroxyphenyllactic acid; VMA, vanillylmandelic acid (4...