Markers of nucleic acids and proteins oxidative damage in acute methanol poisoning
MONATSHEFTE FUR CHEMIE
Authors: Hlusicka, Jiri; Loster, Tomas; Lischkova, Lucie; Vaneckova, Manuela; Diblik, Pavel; Urban, Pavel; Navratil, Tomas; Kacer, Petr; Kacerova, Tereza; Zakharov, Sergey
Abstract
The aim of the study is to measure serum concentrations of markers of nucleic acids and proteins oxidative damage in humans to study the dynamics and clinical determinants of oxidative stress caused by acute methanol poisoning. Acute blood serum samples for this study were collected from 28 patients with methanol poisoning and the follow-up samples from 36 survivors of poisoning were collected 2years after discharge. Serum concentrations of 8-hydroxy-2-deoxyguanosine (8-OHdG), 8-hydroxyguanosine (8-OHG), 5-(hydroxymethyl)uracil (5-OHMU), ortho-tyrosine (o-Tyr), nitrotyrosine(NO-Tyr), and chlorotyrosine (Cl-Tyr) were measured by liquid chromatography-electrospray ionisation-tandem mass spectrometry. Acute concentrations of 8-OHdG and o-Tyr were significantly higher than the follow-up concentrations (94.46.2 versus 78.0 +/- 10.0pgcm(-3); p=0.009 and 163.0 +/- 11.0 versus 124.0 +/- 17.0pgcm(-3); p<0.001, correspondingly). Survivors of methanol poisoning had higher acute 8-OHdG and 8-OHG concentrations than those who died (97.3 +/- 7.4 versus 50.0 +/- 23.0pgcm(-3); p<0.001 and 97.9 +/- 7.2 versus 83.7 +/- 6.7pgcm(-3); p=0.047). Acute concentrations of 8-OHdG, 8-OHG, 5-OHMU, and o-Tyr were higher in the patients who survived without health sequelae than in those who survived with visual and CNS sequelae (all p<0.05). Acute concentrations of markers of proteins and nucleic acids damage correlated with laboratory parameters of acidemia (anion gap) and serum ethanol concentration on admission (both p<0.05). Acute elevation of the concentration of markers of nucleic acids and proteins oxidative damage in the patients with methanol poisoning suggest that mild-to-moderate oxidative stress may play an important role in the non-specific mechanisms of brain protection against direct neurotoxic effects of formic acid. [GRAPHICS] .
Direct determination of nucleosides in the urine of patients with breast cancer using column-switching liquid chromatography-tandem mass spectrometry
BIOMEDICAL CHROMATOGRAPHY
Authors: Cho, Sung-Hee; Jung, Byung Hwa; Lee, Sang Hee; Lee, Won-Yong; Kong, Gu; Chung, Bong Chul
Abstract
We developed an analytical method for a simple, sensitive and simultaneous determination of oxidized nucleosides in urine using column-switching liquid chromatography-electrospray/tandem mass spectrometry (LC-ESI/MS/MS). We connected two columns through a six-way switching valve and effectively separated nucleosides in the urine from the interference by column-switching liquid chromatography. We monitored separated nucleosides using positive ionization tandem mass spectrometry in selective reaction monitoring (SRM) mode. The calibration ranges of nucleosides were 0.2-100 nmol/mL. The linearity of the method was 0.994-0.999, and the limits-of-detection (LOD) at a signal-to-noise (S/N) ratio of 3 were 0.1-0.2 nmol/mL. The coefficients of variation were in the range 2.28-11.74% for within-day variation and 4.36-11.15% for day-to-day variation, respectively. To explore the relationship between breast cancer and the nucleosides level in human urine, we measured the concentrations of nucleosides in female patients with breast cancer (n = 30) and in normal female subjects (n = 30). The concentration of nucleosides was significantly increased in patients with breast cancer when compared with the normal controls (1-methyladenosine; p < 0.005, N-2,N-2-dimethylguanosine; p < 0.01, 5-hydroxymethyl-2'-deoxyuridine; p < 0.001, 8-hydroxy-2-deoxyguanosine; p < 0.001). Therefore, the elevated levels of nucleosides could be used as an important biomarker for breastcancer research. Copyright (c) 2006 John Wiley & Sons, Ltd.