Li-Yu Tsai

Evidence for accelerated generation of hydroxyl radicals in experimental obstructive jaundice of rats.

We present evidence herein of the accelerated generation of hydroxyl radical (.OH) in the plasma and the liver tissue of common bile duct ligated (CBDL) rats, a model for experimental obstructive jaundice. .OH production in the plasma was monitored in vivo by the identification of dihydroxybenzoates in plasma [2,3-dihydroxybenzoate (2,3-DHB) and 2,5-dihydroxybenzoate (2,5-DHB)] using high performance liquid chromatography (HPLC). The average concentrations of 2,3-DHB and 2,5-DHB produced in the plasma of the controls were 33+/-3 microM and 232+/-34 microM (n = 15), respectively, whereas their respective concentrations increased to 149+/-28 microM and 604+/-88 microM in the CBDL rats (n = 19). Furthermore, we also observed a time-dependent decreasing trend of 2,3-DHB and 2,5-DHB production after surgical removal of the ligation of the experimental animals. In addition, the generation of .OH in the liver tissue was studied by using dimethyl sulfoxide (DMSO) as a molecular probe and measuring the amount of methanesulfinic acid (MSA), the product of the trapping reaction. The net production of MSA in the liver tissue of the control rats was 1.22+/-0.05 O.D. unit/g protein (n = 5), whereas its respective concentration of MSA in the liver tissue of CBDL rats increased to 2.05+/-0.15 O.D. unit/g protein (n = 5). In addition, we showed that CBDL rats receiving a pretreatment of mannitol, an .OH scavenger, resulted in the decreased production of MSA. Electron micrographic study indicated that the most prominent change observed in CBDL rats was the alteration of mitochondria, which were swollen with distorted cristae. Meanwhile, the bile canaliculi were moderately more dilated than that of the controls, and an increased neutrophil peripheral blood count was found in CBDL rats when compared to the controls. Taken together, our data suggest that accelerated generation of .OH in the CBDL rats is obvious and may play a key role in the pathogenesis of liver damage associated with obstructive jaundice.

Changes of lipid peroxide levels in blood and liver tissue of patients with obstructive jaundice

Plasma lipid peroxide levels, hereafter referred to as PLP levels, were measured in a group of 40 apparently healthy controls and 64 cholelithiasis patients, 40 with and 24 without jaundice. Hepatic lipid peroxide (HLP) levels were also measured in 26 patients, 15 with and 11 without jaundice. There was a significantly higher mean concentration of PLP in the jaundiced patients than in the control or jaundice-free cases. However, the difference in PLP levels between the jaundice-free and the control cases was insignificant. Meanwhile, patients with jaundice had significantly higher HLP levels than those without jaundice. In the jaundiced cases, the increased PLP and HLP levels were clearly related to the serum levels of bilirubin respectively. In addition, the HLP levels were positively correlated with the PLP levels; however, in the non-jaundiced cases, there was little evidence of these two relationships. Patients with or without jaundice had lower plasma vitamin E levels in comparison to the control cases. The correlation of plasma vitamin E and PLP levels was weak in all of the jaundiced. However, when we subdivided the jaundiced into two groups, the correlation was strong in those with plasma vitamin E levels < 8.5 micrograms/ml, while the correlation was weak in those with plasma vitamin E levels > 8.5 micrograms/ml. Consequently, these results suggest that there is an involvement of lipid peroxidation in liver cells damaged by obstructive jaundice in cholelithiasis patients and there exists a negative correlation between low vitamin E and lipid peroxide levels in plasma.

Side effects after docetaxel treatment in Taiwanese breast cancer patients with CYP3A4, CYP3A5, and ABCB1 gene polymorphisms

BACKGROUND Breast cancer patients initiating TEC (including docetaxel, epirubicin, and cyclophosphamide) treatment were genotyped for CYP3A4, CYP3A5, and ABCB1 to identify variability factors of side effects for docetaxel. METHODS The planned dose of docetaxel per course was formulated according to each patients height and weight. Each participant had received TEC treatment for 6 consecutive cycles. The single nucleotide polymorphisms (SNPs) of CYP3A4*4 (352A > G), CYP3A4*5 (653C > G), and CYP3A4*18A (20070T > C) for the CYP3A4 gene, CYP3A5*3A (6986A > G) for the CYP3A5 gene, and -41A > G, -145C > G, 1236C > T, 2677G > T(A), and 3435C > T SNPs for the ABCB1 gene were determined by using the restriction fragment length polymorphism of polymerase chain reaction products and the restriction enzymes. RESULTS Fifty-nine Taiwanese women (mean age, 46 y; range, 30-64 y) treated for breast cancer with TEC were recruited. We found that patients carrying the CYP3A5*1/*3 genotype demonstrated more side effects of fever, pleural effusion, and febrile neutropenia than those with the CYP3A5*3/*3 genotype (p = 0.075, 0.077, and 0.030, respectively); moreover, patients with the ABCB1 2677G/G genotype also showed more side effects of fever and febrile neutropenia than those with other genotypes (p = 0.024 and 0.027), In regard to ABCB1 3435C>T, patients with ABCB1 3435C/C tended to suffer leucopenia (p = 0.057). CONCLUSIONS There could be correlations between certain side effects of docetaxel treatment and polymorphisms of these metabolic enzymes. Unfortunately, there is not so much evidence due to the small sample size of this study which restricts the statistical power.

The association between lipid profiles and breast cancer among Taiwanese women.

Abstract Background: Breast cancer incidence increased seven-fold from 1979 to 2002, and it has become the second most common cancer in Taiwanese women. Although the relationship between high-density lipoprotein cholesterol (HDL-C) and breast cancer has been studied, no consistent association has been explicitly confirmed. The aim of this study was to demonstrate the relationship between breast cancer and lipid profiles in Taiwanese women. Methods: A total of 150 breast cancer patients before treatment and 71 healthy controls were enrolled. Lipid profiles in fasting serum were measured after participants gave their consent. Results: The breast cancer patients had significantly lower values for HDL-C and apolipoprotein A-I (apoA-I), lower apoA-I/apoB ratios and higher values for very-low-density lipoprotein cholesterol (VLDL-C) than controls. After logistic regression analysis, the breast cancer patients had significantly higher values for VLDL-C and lower values for apoA-I after controlling for HDL-C and the apoA-I/apoB ratio. Conclusions: Our findings demonstrate that higher VLDL-C and lower apoA-I values were significantly associated with breast cancer, with a greater association between apoA-I values and the development of breast cancer than for HDL-C values. Clin Chem Lab Med 2007;45:1219–23.

Evaluation of redox statuses in patients with hepatitis B virus-associated hepatocellular carcinoma.

Background Excess reactive oxygen species related to neoplasia of liver has been established. Essentially, the human body has developed different antioxidant systems for defence against these attacks. To evaluate the redox status in hepatocellular carcinoma (HCC) induced by hepatitis B virus (HBV), the most important aetiological factor in Taiwan, changes in O2 . generation, lipid peroxidation as well as antioxidant status in the blood of HCC patients with HBV carriers for more than 20 years were measured. Methods Superoxide anion radical (O2 .−) generation and the levels of malondialdehyde (MDA) served as an index of lipid peroxidation along with the analyses of activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GRx); also, glutathione status, including reduced glutathione (GSH) and oxidized glutathione (GSSG), and the levels of vitamins A, C and E were determined. Results In 54 patients, the levels of O2 .−, MDA and GSSG, and the activities of SOD and GRx of blood were significantly higher than those of 57 controls. Conversely, the levels of GSH and total GSH, and GSH/GSSG ratio, and vitamins A and C were significantly decreased. Additionally, there were no significant changes in the activity of GPx and the levels of vitamin E. Conclusions Our data suggest that the redox statuses in patients with HBV-associated HCC were elevated or decreased in certain parameters. However, the increased activities of antioxidant enzymes may be a compensatory up-regulation and the decrease antioxidant statuses were responses to the enhanced oxidative stress in those patients.

The clinical significance between activation of nuclear factor kappa B transcription factor and overexpression of HER-2/neu oncoprotein in Taiwanese patients with breast cancer.

BACKGROUND This study investigated the role of nuclear factor-kappa B (NF-kappaB) activity in human breast cancer with overexpression of HER-2/neu oncoprotein, as well as its role on expression of different histological grades of cancer cells taken from Taiwanese breast cancer patients. MATERIALS AND METHODS Specimens were collected from 82 female breast cancer patients. The HER-2/neu oncoprotein was measured by immunohistochemistry. NF-kappaB activity expression was assessed by the electrophoretic mobility shift assay, and confirmed by the supershift technique using anti-P65 antibody in both breast cancer tissue and the adjacent normal tissue. The histological grades were measured by Modified Bloom-Richardson Grading Scheme. RESULTS Of the 82 cancer specimens, 81 (98.7%) showed higher or equal expressions of NF-kappaB activity when compared to the adjacent normal tissue. Fifty-five cases (67.1%) had higher levels of NF-kappaB activity in the cancerous tissue than in the adjacent normal tissue (p<0.005). With regard to tumor size, steroid receptors, stages, histological types, and node status, there were no statistically significant differences in NF-kappaB activity between cancerous tissues and adjacent normal tissues. However, significantly higher expressions of NF-kappaB activity were seen in those cases with positive HER2/neu oncoprotein, poorly differentiated histological grades, high nuclear pleomorphisms, and high mitotic counts (p<0.05). Positive HER-2/neu overexpression of oncoprotein had higher NF-kappaB activity (86%) than negative overexpression (60%) (p<0.05). It has been shown that the NF-kappaB activity increases in the HER-2/neu oncoprotein overexpression in human breast cancer. CONCLUSION Overexpression of HER-2/neu gene could induce NF-kappaB activity in human breast cancer cells, as has been confirmed in other research on cell lines.

Lipid peroxidation and antioxidative status in β-thalassemia major patients with or without hepatitis C virus infection

Abstract Background: Information pertaining to the lipid peroxidation and antioxidative status of patients with β-thalassemic major, with or without hepatitis C virus infection, has been scanty. Methods: We report here the results of our efforts in the evaluation of lipid peroxidative status, antioxidants, and vitamin A, E and C levels in the sera of a group of patients (n=42) with transfusion-dependent β-thalassemic major with or without HCV infection. Results: Firstly, plasma thiobarbituric acid reactive substance, a lipid peroxidation product, in these patients was found to be increased significantly when compared to the disease-free controls (p<0.05). Conversely, levels of plasma vitamins A, E and C were all shown to be drastically reduced as compared to the disease-free controls (p<0.01). In parallel with these data, we also found that HCV infection did play some role in aggravating the depletion of plasma vitamin E and C levels in the β-thalassemic patients. In contrast, HCV infection did not seem to alter the levels of reduced glutathione (GSH) as well as antioxidant enzyme activities including superoxide dismutase and GSH peroxidase. Conclusions: Taken together, our data indicate that excessive lipid peroxidation and a profound depletion of plasma vitamin A, E and C levels exist in patients with β-thalassemic major. These data suggest that antioxidant supplementation to the patients for the purpose of alleviating the oxidative stress may be warranted. Clin Chem Lab Med 2006;44:1226–33.

Oxidative stress-related enzyme gene polymorphisms and susceptibility to breast cancer in non-smoking, non-alcohol-consuming Taiwanese women: a case-control study

Background Mitochondrial manganese superoxide dismutase (MnSOD) converts superoxide anion into H2O2, which is neutralized sequentially by either catalase (CAT) or glutathione peroxidase 1 (Gpx 1) into water or converted into highly reactive hypochlorous acid by myeloperoxidase (MPO). We hypothesize that gene variants for these enzymes might be associated with the risk of breast cancer in non-smoking, non-alcohol-consuming women. Methods Genotypes of oxidative stress-related enzymes (MnSOD1183T>C, MPO-463G>A, GPx1Pro198Leu and CAT-262C>T) were analysed in 260 non-smoking and non-alcohol-consuming female patients with breast cancer and 224 habit-matched controls. Results Subjects with the MnSOD1183T>C C carrier or those with the GPx1Pro198Leu CT genotype had significantly decreased age-adjusted risks (odds ratio [OR]: 0.56 and 0.16 with 95% confidence intervals [95% CI]: 0.38–0.83 and 0.08–0.29, respectively) for breast cancer. Certain combined genotypes of the polymorphisms also significantly modulated the age-adjusted risk. Conclusions We conclude that oxidative stress-related enzyme genetic variants, especially GPx1Pro198Leu CT, modify the risk of breast cancer development in non-smoking and non-alcohol-consuming women. The role of unidentified environmental factors predisposing to breast cancer development through an oxidative stress mechanism merits further investigation.

Effects of the Hb E, Hb H and Hb G-Taichung variants on HbA1c values by the Bio-Rad variant™ II turbo analyzer

OBJECTIVES The influences of Hb variants on HbA(1c) values can cause mismanagement of diabetes; therefore, the effects of Hb E, H, and G-Taichung variants were evaluated. DESIGNS AND METHODS HbA(1c) values of 2105 samples, including 37 samples with Hb E, H and G-Taichung variants identified by Hb electrophoresis and the PCR sequence, were evaluated by the ion-exchange (Bio-Rad Variant II Turbo analyzer) and boronate affinity (Primus CLC 385 analyzer) high performance liquid chromatography (HPLC) methods. RESULTS In the patients with the Hb E and H variants, their HbA(1c) values determined by ion-exchange HPLC were significantly higher than those by boronate affinity HPLC. However, there were no significant differences of the HbA(1c) values in the patients with the Hb G-Taichung variant. CONCLUSIONS The HbA1c levels might be interfered by the Hb E and H variants, but not the Hb G-Taichung variant, measured by the Bio-Rad Variant II Turbo analyzer.

Association between the apolipoprotein E genotypes and breast cancer patients in Taiwanese.

SummaryTo display the association between the apolipoprotein E (APOE) genotypes and breast cancer patients, a cross sectional study including 291 patients and 148 controls was performed. The APOE genotypes were measured in all participants, and the pathological diagnosis, estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 (HER-2) among breast cancer patients were collected. The results showed the APOE allele frequency in breast cancer patients was 11.7% ɛ2 carriers, 74.6% ɛ3 carriers and 13.7% ɛ4 carriers, and there was no significant difference when they were compared with those of the control group (15.5% ɛ2 carriers, 74.3% ɛ3 carriers and 10.1% ɛ4 carriers; p=0.342). Among the patients in pre-menopause, showed a higher frequency of ɛ2 carriers had the cancer site on the left than that of the ɛ3 carriers (78.6% versus 40.3%; p=0.019). Among breast cancer patients, there was no significant association between the APOE genotypes and menopausal status, pathological diagnosis, estrogen receptor, progesterone receptor, and HER-2. Our findings demonstrated that the APOE genotypes were not associated with breast cancer patients, and ɛ2 allele tended to induce breast cancer on the left site among those patients in pre-menopause.