1/4. adenine phosphoribosyltransferase deficiency: a case diagnosed by GC-MS identification of 2,8-dihydroxyadenine in urinary crystals.light microscopy of the urinary sediment from a child suffering from urinary tract disease showed massive crystalluria. Most of the sediment consisted of characteristic round and brownish crystals. 2,8-Dihydroxyadenine was identified in the crystals by means of gas chromatography-mass spectrometry. The diagnosis of adenine phosphoribosyltransferase deficiency was established by the finding of a very low activity of this enzyme in erythrocytes from the patient, and of half the normal activity in the patients. The patient was first treated with a diet low in purine and with a high liquid intake. She stayed symptomless on this regimen, but the crystalluria persisted. On low doses of allopurinol the crystalluria disappeared.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
2/4. Detection of inherited adenylosuccinase deficiency by two dimensional thin layer chromatography of urinary imidazoles.patients with inherited adenylosuccinase deficiency excrete large quantities of succinyloaminoimidazolecarboxamide riboside (SAICAR) and succinyloadenosine (SAdo). A two dimensional thin layer chromatography method for the detection of SAICAR is described. The method consists of 1: isolation of imidazoles with a cation exchange resin; 2: tlc on cellulose plates, solvent I: isopropanol-ammonia 10% (4:1) and II: butanol-acetic acid-water (4:1:1); detection with Pauly reagent. SAICAR gives rise to an isolated spot with a characteristic bluish color. Also a simple one dimensional thin layer chromatography method for screening of high risk populations is given. Four new cases could be diagnosed. Clinical and chemical data, including concentrations of SAICAR and SAdo in urine, plasma and cerebrospinal fluid, determined by column chromatography, are presented.- - - - - - - - - - ranking = 7keywords = chromatography (Clic here for more details about this article) |
3/4. On the metabolism of allopurinol. Formation of allopurinol-1-riboside in purine nucleoside phosphorylase deficiency.allopurinol-1-riboside, a major metabolite of allopurinol, is commonly thought to be directly synthesized by purine nucleoside phosphorylase (PNP) in vivo. As this enzyme is otherwise believed to function in vivo primarily in the direction of nucleoside breakdown, we have determined by high performance liquid chromatography and a conventional chromatographic method the urinary metabolites of allopurinol in a child deficient of PNP. In this patient approximately 40% of urinary allopurinol metabolites consisted of allopurinol-1-riboside, thus proving the possibility of indirect formation of allopurinol-1-riboside via allopurinol-1-ribotide in vivo, catalysed by hypoxanthine guanine phosphoribosyltransferase (HGPRT) and a phosphatase.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
4/4. Pyrimidine and purine metabolites in ornithine carbamoyl transferase deficiency.Detailed biochemical studies have been carried out in a female heterozygote for ornithine carbamoyl-transferase (OCT) deficiency. Increased levels of the pyrimidines, orotic acid, uridine and uracil, were observed in plasma as well as urine by utilizing an adaptation of high performance liquid chromatography (HPLC). Urinary clearances of these compounds were high, that of orotic acid indicating net secretion. Urinary uric acid clearance was also elevated, a finding attributed to the uricosuric effect of the orotic acid excreted concomitantly. The results in this child and her family are typical of OCT deficiency. They confirm considerable genetic heterogeneity in the biochemical as well as clinical expression in this defect.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |