Whitley C B, Ridnour M D, Draper K A, Dutton C M, Neglia J P
Department of Pediatrics, University of Minnesota Medical School, Minneapolis 55455.
Clin Chem. 1989 Mar;35(3):374-9.
This direct method for quantifying excessive urinary glycosaminoglycan excretion exploits the specific binding of 1,9-dimethylmethylene blue (DMB). The procedure obviates cumbersome and labor-intensive procedures for separating glycosaminoglycans from other constituents of urine. Pediatric pharmaceutical formulations (except heparin), in concentrations expected in urine, do not interfere with spectrophotometry, nor does protein. Results can be expressed in terms of urinary creatinine; thus the test is applicable to very small urine specimens (0.1 mL), such as those obtainable from neonates. In a pilot study, results of the direct DMB test for 48 urine specimens agreed with the clinical diagnosis, and quantitative measurements correlated moderately (r = 0.76) with results of a commonly used procedure (carbazole-borate reactivity after precipitation with cetylpyridinium chloride). The present method was also used to assess metabolic correction in a patient with Hurler's syndrome after treatment by bone-marrow transplantation. This quantitative method surmounts the major technical problems of developing mass screening programs for infants, thus offering the potential for earlier diagnosis and treatment of mucopolysaccharidosis diseases.
这种用于定量检测尿中糖胺聚糖排泄过多的直接方法利用了1,9-二甲基亚甲蓝（DMB）的特异性结合。该方法避免了从尿中其他成分分离糖胺聚糖的繁琐且劳动强度大的程序。儿科药物制剂（肝素除外），在尿液中预期的浓度下，不会干扰分光光度法，蛋白质也不会。结果可以用尿肌酐表示；因此该检测适用于非常少量的尿液标本（0.1 mL），比如从新生儿获取的标本。在一项初步研究中，48份尿液标本的直接DMB检测结果与临床诊断相符，定量测量结果与常用程序（用十六烷基吡啶氯化物沉淀后的咔唑-硼酸盐反应性）结果呈中度相关（r = 0.76）。本方法还用于评估一名黏多糖贮积症Ⅰ型患者骨髓移植治疗后的代谢纠正情况。这种定量方法克服了为婴儿开展大规模筛查项目的主要技术问题，从而为黏多糖贮积症疾病的早期诊断和治疗提供了可能性。
