55 research outputs found
Simultaneous Detection of 3‑Nitrotyrosine and 3‑Nitro-4-hydroxyphenylacetic Acid in Human Urine by Online SPE LC-MS/MS and Their Association with Oxidative and Methylated DNA Lesions
Reactive
nitrogen species (RNS) can modify proteins at tyrosine
and tryptophan residues, and they are involved in the pathogenesis
of various human diseases. In this study, we present the first liquid
chromatography–tandem mass spectrometry (LC-MS/MS)-based method
that enables the simultaneous measurement of urinary 3-nitrotyrosine
(3-NTYR) and its metabolite 3-nitro-4-hydroxyphenylacetic acid (NHPA).
After the addition of stable isotope-labeled internal standards, urine
samples were purified and enriched using manual solid-phase extraction
(SPE) and HPLC fractionation followed by online SPE LC-MS/MS analysis.
The limits of quantification in urine were 3.1 and 2.5 pg/mL for 3-NTYR
and NHPA, respectively. Inter- and intraday imprecision was <15%.
The mean relative recoveries of 3-NTYR and NHPA in urine were 89–98%
and 90–98%, respectively. We further applied this method to
65 urinary samples from healthy subjects. Urinary samples were also
analyzed for <i>N</i>-nitrosodimethylamine (NDMA) as well
as oxidative and methylated DNA lesions, namely, 8-oxo-7,8-dihydroguanine
(8-oxoGua), 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodGuo), <i>N</i>7-methylguanine (N7-MeG), and <i>N</i>3-methyladenine
(N3-MeA), using reported LC-MS/MS methods. Urinary 3-NTYR and NHPA
levels were measured at concentrations of 63.2 ± 51.5 and 77.4
± 60.8 pg/mL, respectively. Urinary 3-NTYR and NHPA levels were
highly correlated with each other and with 8-oxoGua and 8-oxodGuo.
Our findings demonstrated that a relationship exists between oxidative
and nitrative stress. However, 3-NTYR and NHPA were correlated with
N7-MeG and N3-MeA but not with NDMA, suggesting that NDMA may not
be a representative biomarker of <i>N</i>-nitroso compounds
that are induced by RNS
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Association Study between the <i>FTCDNL1</i> (<i>FONG) </i>and Susceptibility to Osteoporosis
<div><p>Osteoporosis is a systemic skeletal disease characterized by a decreased bone mineral density that results in an increased risk of fragility fractures. Previous studies indicated that genetic factors are involved in the pathogenesis of osteoporosis. Polymorphisms of the <i>FONG (FTCDNL1)</i> gene (rs7605378) were reported to be associated with the risk of osteoporosis in a Japanese population. To assess whether polymorphisms of the <i>FTCDNL1</i> gene contribute to the susceptibility and severity of osteoporosis in a Taiwanese population, 326 osteoporosis patients and 595 controls of a Taiwanese population were included in this study. Our results indicated that rs10203122 was significantly associated with osteoporosis susceptibility among female. Our findings provide evidence that rs10203122 in <i>FTCDNL1</i> is associated with a susceptibility to osteoporosis.</p></div
Genotype and allele frequencies of the <i>CD209</i> gene in controls and patients with Kawasaki disease.
<p>*Significant (<i>P</i><0.05) values are in bold.</p>a<p><i>P</i> values are calculated using the Pearson's x<sup>2</sup> test for the recessive model.</p>b<p>ORs are for the recessive model (minor allele homozygotes versus heterozygotes and major allele homozygotes).</p
Genotype and allele frequencies of the <i>CD209 </i>gene in patients with Kawasaki disease responding or not responding to intravenous immunoglobulin treatment.
<p>*Significant (<i>P</i><0.05) values are in bold.</p>a<p><i>P</i> values are calculated using the Pearson's x<sup>2</sup> test for the recessive model.</p>b<p>ORs are for the recessive model (minor allele homozygotes versus heterozygotes and major allele homozygotes).</p
Haplotype frequencies of the <i>CD209</i> gene in controls and patients with Kawasaki disease.
<p>Haplotype frequency less than 1% was excluded.</p
Haplotype frequencies of the <i>ITPKC</i> gene in patients with Kawasaki disease with or without coronary artery lesion formation.
<p>Haplotype frequency less than 1% was excluded. *Significant (<i>P</i><0.05) values are in bold. CAL: coronary artery lesions.</p
CD209 gene linkage disequilibrium and haplotype block structure in KD.
<p>The number on the cell is the LOD score of D′.</p
<i>FTCDNL1</i> gene linkage disequilibrium and haplotype block structure in osteoporosis.
<p>The number on the cell is the D’ (D’ x 100).</p
Basal characteristics of patients with Kawasaki disease and normal controls.
<p>CAL: coronary artery lesions; IVIG: intravenous immunoglobulin; SD: standard deviation.</p
<i>ITPKC</i> gene linkage disequilibrium and haplotype block structure in KD.
<p>The number on the cell is the LOD score of D'.</p
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