The Tandem ICON pregnancy test for detecting human choriogonadotro- pin (hCG) in urine is a visual immu- noenzymetric assay, produced by Hy- britech, Inc.
1. Fishlock RC, Bieber LL, Snoswell AM. Sources of error in determinations of carnitine and acylcarnitine in plasma. Clin Chem 30, 316-318 (1984). 2. Brass EP, Hoppel CL. Carnitine metabolism in the fasting rat. J Biol Chem 253, 2688-2693 (1978). 3. Genuth SM, Hoppel CL. Plasma and urine carnitine in diabetic ketosis. Diabetes 28, 1083-1087 (1978). 4. Hoppel CL, Genuth SM. Carnitine metabolism in normal-weight and obese human subjects during fasting. Am J Physiol 238, E409-E415 (1980). 5. Fuller RK, Hoppel CL. Elevated plasma carnitine in hepatic cirrhosis. Hepatology 3, 554-558 (1983). 6. Roe CR, Millington DS, Maitby DA, et al. i.-Carnitine enhances excretion of propionyl coenzyme A as propionylcarnitine in propionic acidemia. J Clin Invest 73, 17851788 (1984). 7. Rimoldi M, DiDonato S. Measurement
long chain acylcarnitine. Neurology 32, 916-917 (1982). 8. Brass EP, Hoppel CL. Relationship between acid-soluble carnitine and coenzyme A pools in vivo. Biochem J 190, 495-504 (1980).
Eric P. Brass Depts. of Med. and Pharmacol. Div. of Clin. Pharmacol., Univ. of Colorado Health 4200 East Ninth Ave. Denver, CO 80262
C237 Sci. Center
Depts. of Pharmacol.
and Med. Case Western Reserve Univ. and Cleveland VA Med. Center Cleveland, OH 44106
Asymptomatlc Xanthlnuria Detected as a Result of RoutineAnalysis of Serum for Urate To the Editor:
Biochemical “proffling” is now a common first line of patient investigation, its major advantage being early, pre-symptomatic detection of some diseases-in particular, primary hyperparathyroidism, owing to the inclusion of analysis for serum calcium in the proffle. Recently, the inclusion of serum glucose has proved to be an effective means of early diagnosis of diabetes mellitus (1). Serum urate is often included in the proffle, detection of hyperuricemic states being the prime concern. We have further investigated patients with hypo-uricemia and as a result have diagnosed two unrelated patients with xanthine oxidase (EC 18.104.22.168) deficiency. A total of seven patients with profound hypo-uricemia (serum urate 492
1. ClinicalDetails and Data on Purines Urate concn, MmoI/L
Age at dIagnosIs,
UrIne Serum UrIne Serum 69 (3)C 326 (30) 29 (2) 17
pain 34 15 25 556 20 range 150-450 imol/L. b SB. is the second of five daughters of Pakistani are not affected. cConol figuresin parentheses. dK.B. is from the Ivory Coast.