Yi-Tzu Hsu

Publications (2)7.57 Total impact

• Article: Increased levels of F2-isoprostanes following aneurysmal subarachnoid hemorrhage in humans.

  Chih-Lung Lin, Yi-Tzu Hsu, Tzu-Kang Lin, Jason D Morrow, Jee-Ching Hsu, Yung-Hsing Hsu, Tsung-Che Hsieh, Pei-Kwei Tsay, Hsiu-Chuan Yen
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  ABSTRACT: Subarachnoid hemorrhage (SAH) resulting from aneurysmal rupture is the major cause of nontraumatic SAH. We hypothesized that oxidative stress could be increased following aneurysmal SAH due to hemoglobin release and ischemia-reperfusion injury and that may further contribute to poor outcome. We collected plasma and cerebrospinal fluid (CSF) samples from 11 non-SAH controls and 15 aneurysmal SAH patients for up to 10 days after surgery and investigated status of oxidative stress in patients. Results showed that mean or peak levels of F(2)-isoprostanes (F(2)-IsoPs), a specific marker of lipid peroxidation, and total nitrate/nitrite, metabolites of nitric oxide and peroxynitrite, in CSF and plasma were significantly higher in SAH patients than in controls. First-day levels were also higher in CSF, but not in plasma, in SAH patients. Moreover, mean and peak levels of CSF F(2)-IsoPs were positively correlated with poor outcome or severity of clinical conditions in patients. Furthermore, levels of retinol, delta-tocopherol, beta+gamma-tocopherol, lutein, beta-carotene, and coenzyme Q(10) in plasma were significantly lower in SAH patients than in controls. Our results indicate that oxidative damage may play important roles in the severity and complications of aneurysmal SAH and suggest that means to suppress lipid peroxidation may be beneficial in improving the outcome of aneurysmal SAH.
  Free Radical Biology and Medicine 05/2006; 40(8):1466-73. · 5.42 Impact Factor
• Article: Impurities from polypropylene microcentrifuge tubes as a potential source of interference in simultaneous analysis of multiple lipid-soluble antioxidants by HPLC with electrochemical detection.

  Hsiu-Chuan Yen, Yi-Tzu Hsu
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  ABSTRACT: High-performance liquid chromatography (HPLC) with electrochemical detection was used to analyze lipid-soluble antioxidants and micronutrients in plasma. Small amounts of plasma samples are often extracted in polypropylene (PP) microcentrifuge tubes before HPLC analysis due to its convenience. We therefore investigated the effect of impurities released from different PP tubes during extraction on the electrochemical detection of retinol, lutein, alpha-tocopherol, gamma-tocopherol, retinyl palmitate, beta-carotene and total coenzyme Q10 by an HPLC system with a coulometric array detector (CoulArray HPLC). An array of eight electrical potentials and gradient elution were applied. Human plasma or ultrapure water were extracted in four different PP tubes. Peaks at different retention times with varied amounts of unknown compounds were detected from different PP tubes. Although all those unknown peaks could be differentiated from peaks of interest by the CoulArray HPLC, they caused busy chromatographs, and one peak had an overlap with the dominant peak of lutein. Moreover, that peak completely masked the lutein peak when only one oxidizing potential was applied. Our results suggest potential interference from PP tubes on electrochemical detection especially when using only one electrical potential or having poor separation for these antioxidants if PP tubes are not carefully tested.
  Clinical Chemistry and Laboratory Medicine 05/2004; 42(4):390-5. · 2.15 Impact Factor