Studies in the area of cystinosis therapy reported from University of Nijmegen
2007 AUG 20 -- Research findings, "The origin of halitosis in cystinotic patients due to cysteamine treatment," are discussed in a new report. "Cystinosis is a rare autosomal recessive disorder characterized by the intralysosomal accumulation of cystine. Cysteamine removes cystine from the lysosome and slows down the progression of the disease," scientists writing in the journal Molecular Genetics and Metabolism report. "One of its side effects is the induction of halitosis, which can interfere with patients' willingness to comply with cysteamine treatment. To identify breath sulphur compounds causing halitosis induced by cysteamine therapy in patients with cystinosis. After the ingestion of 15mg/kg cysteamine whole blood (n=4), urine (n=4) and breath (n=8) volatile sulphur compounds levels were measured every 60min over a 360min period by gas chromatography and the cysteamine plasma concentrations (n=4) were measured by high-performance liquid chromatography. The expired air of cystinotic patients contained elevated concentrations of methanethiol (MT, median maximum value 0.5 (range 0-11)nmol/L) and, in particular, dimethylsulphide (DMS, median maximum value 15 (range 2-83)nmol/L). DMS concentrations higher than 0.65nmol/L are known to cause halitosis. Maximal plasma values of cysteamine (median 46 (range 30-52)micromol/L) preceded those of MT and DMS, confirming that cysteamine is converted to MT and DMS. Less than 3% of the amount of cysteamine ingested was excreted as MT and DMS via expired air and 0.002% via urine. Halitosis induced by cysteamine intake is caused by DMS and to a lesser extent by MT, excreted via the expired air," wrote M. Besouw and colleagues, University of Nijmegen. The researchers concluded: "Further studies should focus on the possibilities of reducing the formation of these volatile sulphur compounds or masking their odour, which would improve the rates of compliance with cysteamine treatment." Besouw and colleagues published their study in Molecular Genetics and Metabolism (The origin of halitosis in cystinotic patients due to cysteamine treatment. Molecular Genetics and Metabolism, 2007;91(3):228-33). Additional information can be obtained by contacting M. Besouw, Radboud University Nijmegen Medical Centre, Dept. of Pediatric Nephrology, Nijmegen, PO Box 9101, 6500 HB Nijmegen, Netherlands. The publisher of the journal Molecular Genetics and Metabolism can be contacted at: Academic Press Inc. Elsevier Science, 525 B St., Ste. 1900, San Diego, CA 92101-4495, USA. Keywords: Netherlands, Cysteamine, Cystinosis, Genetics, Halitosis, Metabolism, Nephropathic Cystinosis Therapy, Radiation-Protective Agent. This article was prepared by Biotech Business Week editors from staff and other reports. Copyright 2007, Biotech Business Week via NewsRx.com.
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