Evaluation of whole blood @entity750 and plasma and urine @entity1130 in diagnosis of XXXX .

@entity1 @entity5 @entity5581 @entity1130 @entity750 @entity4303 @entity26555
BACKGROUND: @entity26555 is an uncommon disorder resulting from @entity5 of the enterochromaffin cells. Current biochemical investigation usually involves the measurement of @entity1130 ( @entity5581 ) in 24-h urine collections. Because of the problems associated with urine collections (i.e. inconvenience, accuracy of collection and requirement for preservatives) two alternative markers, fasting plasma @entity5581 and whole blood @entity750 ( @entity750 ), have been studied. METHODS AND RESULTS: Whole blood @entity750 concentration and plasma and urine @entity5581 concentrations were measured by high-performance liquid chromatography in 31 @entity1 suspected of having @entity4303 and 26 known @entity4303 @entity1 . Receiver operator characteristic curve analysis of the data showed no statistical difference between the three markers (P>0.01) with regard to their discriminating function. However, fasting plasma @entity5581 assay showed greater stability than whole blood @entity750 assay and is more convenient for the @entity1 than a 24-h urine collection. At a cut-off value of 118 nmol/L plasma @entity5581 assay showed a sensitivity of 89%, a specificity of 97% and a test efficiency of 93%. Whole blood @entity750 assay was further limited by its saturation in platelets at 40 nmol/10(9) platelets which made it less suitable for monitoring the treatment of @entity26555 . CONCLUSION: Fasting plasma @entity5581 concentration provides a more convenient screening test for @entity4303 and overcomes the problems associated with 24-h urine collections, without any loss of diagnostic precision.
