Cystinuria is an inherited disorder characterized by impaired apical transport of cystine and dibasic amino acids (e.g., ornithine, lysine, and arginine) in the renal proximal tubule and the small intestine epithelia. The overall estimated prevalence is 1/7000 neonates (1). Because of impaired renal cystine reabsorption, cystine precipitates and forms calculi that can produce urinary tract obstruction and may lead to renal insufficiency. Cystinuria is responsible for ∼10% of all kidney stones observed in children; in ∼50% of patients, stones form in the first decade of life. Diagnosis allows introduction of therapy to reduce stone formation and risk of renal impairment. Prenatal biochemical expression of the disease has not been described. Fetal hyperechogenic small bowel (FHB), an infrequent ultrasound finding (0.1%–1.8% of pregnancies), is associated with severe fetal diseases such as cystic fibrosis and trisomy 21 (2). Even less common is fetal hyperechogenic colon (FHC) in which the hyperechogenicity is strictly limited to the colon. Recently, it has been suggested that FHC could be associated with cystinuria(3). We found biochemical prenatal evidence of cystinuria and confirmed the association of cystinuria with …

1. Wald NJ, Cuckle H, Nanchahal K. Amniotic fluid acetylcholinesterase measurement in the prenatal diagnosis of open neural tube defects. Second Report of the Collaborative Acethylcholinesterase Study. Prenat Diagn 1989;9:813–29. 2. Canick JA, Kellner LH, Bombard AT. Prenatal screening for open neural tube defects. Lab Med 2003;23:385–94. 3. Hoffman A, Nimtz M, Getzlaff R, Conradt HS. “Brain type” N-glycosylation of asialotransferrin from human cerebrospinal fluid. FEBS Lett 1995;359:164–8. 4. Meurman OH, Irjala K, Suonpaa J, Laurent B. A new method for the identification of cerebrospinal fluid leakage. Acta Otolaryngol 1979;87: 366–9. 5. Zaret DL, Morrison N, Gulbranson R, Keren DF. Immunofixation to quantify 2-transferrin in cerebrospinal fluid to detect leakage of cerebrospinal fluid from skull injury. Clin Chem 1992;38: 1908–12. 6. Clayton P, Winchester B, Di Tomaso E, Young E. Carbohydrate-deficient glycoprotein syndrome: normal glycosylation in the fetus. Lancet 1993; 341:956.

Prenatal diagnosis of neural tube defects (NTDs) is based on ultrasonography; but uncertainty exists in a few cases, and biochemical analysis of amniotic fluid (AF) is required. Electrophoresis of AF acetylcholinesterase is a specific and sensitive method for diagnosis of myelomeningocele (1)(2). Although false-positive results are rare, another biochemical technique would be of great value. Adult and infant cerebrospinal fluid (CSF) is characterized by a specific marker, asialotransferrin or β2-transferrin, because it migrates more slowly in electrophoresis than β1-tetrasialotransferrin, the main isoform in all biological fluids (3). The specific behavior of β2-transferrin is used for the detection of CSF leakage from the subarachnoid space into the nasal or aural cavity (4)(5). Assuming that CSF would leak from a myelomeningocele-affected fetus into the AF, we screened AF …

Treatment of adult intact rats with sex steroids (estradiol-17Β, ethynylestradiol, dihydrotestosterone) raises the concentration of serum acute-phaseα1,-acid glycoprotein (AGP). Estrogens are more effective than dexamethasone, and experimental inflammation causes an additive effect on AGP synthesis when ethynylestradiol is given simultaneously. Adrenaline is also able to increase the AGP level. Experiments with adrenalectomized and adrenalectomized plus castrated rats result in a 50% reduction in the serum level of AGP as compared with that in normal and hypophysectomized rats. Although ethynylestradiol is the strongest inducer of AGP synthesis in intact animals, it is unable to enhance significantly the AGP level in adrenalectomized rats, contrary to dexamethasone. Adrenalectomized rats are incapable of undergoing a substantial increase in plasma AGP level following experimental inflammation, and ethynylestradiol or adrenaline cannot take the place of dexamethasone in inducing high levels of AGP in these inflamed rats. These results indicate that glucocorticoids play an obligatory role in modulating AGP synthesis either by directly regulating the AGP gene or in modulating AGP synthesis by increasing the stability of AGP mRNA. Finally, it is suggested that glucocorticoids may also act in unmasking receptor binding sites at the AGP gene level for other mediators such as sex steroids and putative inflammatory factors.

Les auteurs déterminent le titre de deux immunsérums, monospécifiques par la méthode d'immunodiffusion radiale. C'est une technique qui, par sa précision et sa rapidité, trouve de nombreuses applications. Elle permet:— de contrôler à tout moment la qualité d'un immunsérum— en chromatographie d'affinité, de déterminer précisément la quantité d'immunoglobulines spécifiques que peut fixer le support.

The authors determine the titre of two monospecific immunosera by the radial immunodiffusion method. Because of the precision and rapidity of this technique, it is most suitable for: — periodic quality control of an immunoserum — the quantitative estimation of specific immunoglobulins adsorbed to the supporting medium in affinity chromatography.