title: Increased detection rate of melamine-containing calcium urolithiasis by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry technique in clinical practice.
abstract: Background: Studies have shown that melamine may be associated with urolithiasis. A more sensitive method is needed to analyze melamine in urinary stones to identify potential causes of urolithiasis.Methods: Here we compare the analytical methods of detecting melamine in urinary stones by Fourier transform infrared (FTIR) spectroscopy and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS) in the laboratory and clinic. First, we established the melamine detection limit in melamine cyanurate standard by the methods of FTIR spectrophotometer and MALDI-TOF MS. Subsequently, we applied these two methods to 54 adult patients with upper urinary tract calcium urolithiasis.Results: We found that the detection limit of melamine in melamine cyanurate standard by MALD-TOF MS was~10,000-fold more sensitive than FTIR.We applied both instruments to 54 stone specimens from 54 calcium urolithias is patients. In those without distinctive melamine pattern in the FTIR spectra,melamine could be detected by MALD-TOF MS in an additional 12 out of 42 subjects' stone specimens (28.6%). Compared to MALD-TOF MS negative subjects (n = 30), those positive subjects (n = 12) excreted significantly higher urinary melamine levels (P <0.05).Conclusion: Compared to FTIR,MALDI-TOFMS is amore sensitive method in detecting the content of melamine in melamine-containing kidney stones
authors: Department of Public Health, College of Health Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors: Chia-Fang
authors: CF
authors: Wu
authors: Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Pingtung Hospital, Department of Health, Executive Yuan, Pingtung, Taiwan.
authors: Chia-Chu
authors: CC
authors: Liu
authors: Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Urology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors: Yii-Her
authors: YH
authors: Chou
authors: Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan.
authors: Jentaie
authors: J
authors: Shiea
authors: Department of Urology, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors: Jung-Tsung
authors: JT
authors: Shen
authors: Department of Urology, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors: Shiun-Shiuan
authors: SS
authors: Wang
authors: Department of Public Health, College of Health Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Family Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Center of Environmental and Occupational Medicine, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan. Electronic address: 960021@ms.kmuh.org.tw.
authors: Ming-Tsang
authors: MT
authors: Wu
mesh_terms: D000328:Adult; D006801:Humans; D015203:Reproducibility of Results; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared; D014227:Triazines / Q000032:analysis*; D052878:Urolithiasis / Q000378:metabolism*
chemical_list: D014227:Triazines; C071913:melamine cyanurate; C011907:melamine
keywords: Diagnosis; Kidney stones; Mass spectrometry; Melamine