312 results on '"Cheng, Y-W"'
Search Results
102. Mechanism of vasorelaxation of thoracic aorta caused by xanthone
- Author
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Cheng, Y.-W. and Kang, J.-J.
- Published
- 1997
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103. Fatigue Crack Growth of Duplex Stainless Steel Castings at 4 K
- Author
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Purtscher, P. T., Cheng, Y. W., and Li, P. N.
- Abstract
Constant-load-amplitude stage II fatigue crack growth rates at 4 K were measured for duplex stainless steel castings. The results show that at a ΔK of 60 MPa•m1/2, da/dN = 7.6 × 10−4 mm/cycle for an alloy with 1 percent ferrite. For an alloy with 8 percent ferrite, da/dN is 35 percent, and for an alloy with 29 percent ferrite, da/dN is 260 percent greater than for the 1 percent ferrite alloy. However, the exponent in the Paris equation does not change appreciably (less than 18 percent) as the ferrite content changes from 1 to 29 percent.
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- 1985
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104. Disk Residual Life Studies. Part 2. TF30 10th-Stage Compressor Disk (INCOLOY 901).
- Author
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PRATT AND WHITNEY AIRCRAFT GROUP WEST PALM BEACH FL GOVERNMENT PRODUCTS DIV, Cargill,J S, Malpani,J K, Cheng,Y W, PRATT AND WHITNEY AIRCRAFT GROUP WEST PALM BEACH FL GOVERNMENT PRODUCTS DIV, Cargill,J S, Malpani,J K, and Cheng,Y W
- Abstract
A residual fatigue life prediction method, suitable for Retirement-for-Cause application, has been developed for two P&WA turbine disks: the F100 1st-stage high pressure turbine disk and the TF30 10th-stage compressor disk. The method is based upon interaction of fracture mechanics crack propagation modeling concepts with laboratory nondestructive evaluation (NDE) techniques. Fracture mechanics life models were developed using the GPD hyperbolic sine (SINH) model refined during an earlier Air Force Materials Laboratory (AFML) program. Stress intensity (K) solutions for the engine components were based upon experimental effective K determinations made during full-scale component fatigue tests. The NDE techniques developed for disk inspections included acoustic emission (AE), eddy current (EC), and fluorescent penetrants (FP). Stress-enhanced penetrant and semi-automated rotating probe EC techniques were developed as periodic inspections, while the AE time-domain technique was developed as a real-time inspection tool. (Author)
- Published
- 1979
105. Induction of calcium release from sarcoplasmic reticulum of skeletal muscle by xanthone and norathyriol
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JAW-JOU KANG, Cheng, Y. W., Ko, F. N., Kuo, M. L., Lin, C. N., and Teng, C. M.
106. HIV-associated parkinsonism reversed with antiretroviral therapy
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Cheng, Y. -W, Lin, C. -H, and Wu, R. -M
107. BIOLOGICAL FLUIDIZED-BED REACTOR - HYDRODYNAMICS, BIOMASS DISTRIBUTION AND PERFORMANCE
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Slawomir Hermanowicz and Cheng, Y. -W
108. Exploring taiwanese undergraduates' perceptions of teacher authority toward Internet-based learning environments
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Lin, T. -J, Min-Hsien Lee, Cheng, Y. -W, and Lin, H. -M
109. Application of nanosphere lithography to the fabrication of nanorod LEDs and to the performance enhancement of conventional LEDs
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Cheng, Y. -W, Lu, T. -C, Ke, M. -Y, Pan, K. -M, Chen, L. -Y, Chiang, H. -L, Huang, Y. -Y, and Huang, J.
110. Modulation of microsomal cytochrome P450 by Scutellariae Radix and Gentianae Scabrae Radix in rat liver
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JAW-JOU KANG, Chen, Y. -C, Kuo, W. -C, Chen, T., Cheng, Y. -W, Kuo, M. -L, and Ueng, T. -H
111. Effects of cartap on isolated mouse phrenic nerve diaphragm and its related mechanism
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Liao, J. -W, JAW-JOU KANG, Liu, S. -H, Jeng, C. -R, Cheng, Y. -W, Hu, C. -M, Tsai, S. -F, Wang, S. -C, and Pang, V. F.
112. Harmonized Microarray Expression, Array CGH, SNP-LOH, Mutation Scanning, and Methylation Analysis of Colorectal Tumors.
- Author
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Barany, Francis, Cheng, Y.-W., Pincas, H., Huang, J., Shattock, R., Bacolod, M., Pingle, M., Favis, R., Tsafrir, D., Selvanaygam, Z., Shia, J., Zeng, Z., Liu, H., Shemmann, G., and Stengel, R. F.
- Subjects
COLON cancer - Abstract
Presents an abstract of the article "Harmonized Microarray Expression, Array CGH, SNP-LOH, Mutation Scanning, and Methylation Analysis of Colorectal Tumors," by Francis Barany, Y-W. Cheng, H. Pincas, J. Huang, R. Shattock, M. Bacolod, M. Pingle, R. Favis, D. Tsafrir, Z. Selvanaygam, J. Shia, Z. Zeng, H. Lui, G. Schemmann, R.F. Stengel.
- Published
- 2005
113. Biological fluidized bed reactor hydrodynamics, biomass distributionand performance
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Hermanowicz, S. W. and Cheng, Y.-W.
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BIOMASS , *DENITRIFICATION , *HYDRODYNAMICS , *PERFORMANCE - Published
- 1990
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114. Two problems on the 3.000/40/916 Dynamitron
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Zhao, F. and Cheng, Y.-W.
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- 1993
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115. Microstructure control of ferrite-pearlite high strength low alloy steels utilizing microalloying additions
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Kuziak, R., Bold, T., and Cheng, Y. W.
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- 1995
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116. FHIT loss confers cisplatin resistance in lung cancer via the AKT/NF-κB/Slug-mediated PUMA reduction.
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Wu, D-W, Lee, M-C, Hsu, N-Y, Wu, T-C, Wu, J-Y, Wang, Y-C, Cheng, Y-W, Chen, C-Y, and Lee, H
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HISTIDINE , *CISPLATIN , *LUNG cancer treatment , *DRUG resistance in cancer cells , *CANCER chemotherapy - Abstract
Fragile histidine triad (FHIT) loss by the two-hit mechanism of loss of heterozygosity and promoter hypermethylation commonly occurrs in non-small cell lung cancer (NSCLC) and may confer cisplatin resistance in NSCLC cells. However, the underlying mechanisms of FHIT loss in cisplatin resistance and the response to cisplatin-based chemotherapy in NSCLC patients have not yet been reported. In the present study, inhibition concentration of 50% cell viability induced by cisplatin (IC50) and soft agar growth and invasion capability were increased and decreased in FHIT-knockdown and -overexpressing cells, respectively. Mechanistically, Slug transcription is upregulated by AKT/NF-κB activation due to FHIT loss and, in turn, Slug suppresses PUMA expression; this decrease of PUMA by FHIT loss is responsible for cisplatin resistance. In addition, cisplatin resistance due to FHIT loss can be conquered by AKT inhibitor-perifosine in xenograft tumors. Among NSCLC patients, low FHIT, high p-AKT, high Slug and low PUMA were correlated with shorter overall survival, relapse-free survival and poorer response to cisplatin-based chemotherapy. Therefore, the AKT inhibitor perifosine might potentially overcome the resistance to cisplatin-based chemotherapy in NSCLC patients with low-FHIT tumors, and consequently improve the outcome. [ABSTRACT FROM AUTHOR]
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- 2015
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117. c-Myc suppresses microRNA-29b to promote tumor aggressiveness and poor outcomes in non-small cell lung cancer by targeting FHIT.
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Wu, D-W, Hsu, N-Y, Wang, Y-C, Lee, M-C, Cheng, Y-W, Chen, C-Y, and Lee, H
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MYC oncogenes , *MICRORNA , *NON-small-cell lung carcinoma , *CANCER invasiveness , *CANCER cell growth , *METASTASIS - Abstract
The dual role of the microRNA-29 (miR-29) family in tumor progression and metastasis in solid tumors has been reported. Evidence for the role of miR-29 in tumor malignancy and its prognostic value in overall survival (OS) and relapse-free survival (RFS) in non-small cell lung cancer (NSCLC) remains conflicting. Mechanistic studies presented herein demonstrated that c-Myc suppressed the expression of miR-29b, promoting soft agar growth and invasion capability in lung cancer cells. Interestingly, the decrease in the expression of miR-29b by c-Myc is responsible for soft agar growth and invasiveness mediated by FHIT loss due to promoter methylation. Among patients, low expression of miR-29b and FHIT was more common in tumors with high c-Myc expression than in tumors with low c-Myc expression. Kaplan-Meier and Cox regression analysis showed that tumors with high c-Myc, low miR-29b and low FHIT expression had shorter OS and RFS periods than their counterparts. In conclusion, the decrease in the expression of miR-29b by c-Myc may be responsible for FHIT loss-mediated tumor aggressiveness and for poor outcome in NSCLC. Therefore, we suggest that restoration of the miR-29b expression using the c-Myc inhibitor might be helpful in suppressing tumor aggressiveness mediated by FHIT loss and consequently improving outcomes in NSCLC patients with tumors with low expression of FHIT. [ABSTRACT FROM AUTHOR]
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- 2015
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118. Phosphorylation of paxillin confers cisplatin resistance in non-small cell lung cancer via activating ERK-mediated Bcl-2 expression.
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Wu, D-W, Wu, T-C, Wu, J-Y, Cheng, Y-W, Chen, Y-C, Lee, M-C, Chen, C-Y, and Lee, H
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PHOSPHORYLATION , *PAXILLIN , *CISPLATIN , *LUNG cancer , *CANCER cells , *GENE expression , *NATURAL immunity - Abstract
Paxillin (PXN) is required for receptor tyrosine kinase-mediated ERK activation, and the activation of the Raf/MEK/ERK cascade has been linked with Bcl-2 expression. We hypothesized that phosphorylation of PXN by the EGFR/Src pathway might contribute to cisplatin resistance via increased Bcl-2 expression. We show that cisplatin resistance was dependent on PXN expression, as evidenced by PXN overexpression in TL-13 and TL-10 cells and PXN knockdown in H23 and CL1-5 cells. Specific inhibitors of signaling pathways indicated that the phosphorylation of PXN at Y118 and Y31 via the Src pathway was responsible for cisplatin resistance. We further demonstrated that ERK activation was also dependent on this PXN phosphorylation. Bcl-2 transcription was upregulated by phosphorylated PXN-mediated ERK activation via increased binding of phosphorylated CREB to the Bcl-2 promoter. A subsequent increase in Bcl-2 levels by a PXN/ERK axis was responsible for the resistance to cisplatin. Animal models further confirmed the findings of in vitro cells indicating that xenograft tumors induced by TL-13-overexpressing cells were successfully suppressed by cisplatin combined with Src or ERK inhibitor compared with treatment of cisplatin, Src inhibitor or ERK inhibitor alone. A positive correlation of phosphorylated PXN with phosphorylated ERK and Bcl-2 was observed in lung tumors from NSCLC patients. Patients with tumors positive for PXN, phosphorylated PXN, phosphorylated ERK and Bcl-2 more commonly showed a poorer response to cisplatin-based chemotherapy than did patients with negative tumors. Collectively, PXN phosphorylation might contribute to cisplatin resistance via activating ERK-mediated Bcl-2 transcription. Therefore, we suggest that Src or ERK inhibitor might be helpful to improve the sensitivity for cisplatin-based chemotherapy in NSCLC patients with PXN-positive tumors. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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119. DDX3 loss by p53 inactivation promotes tumor malignancy via the MDM2/Slug/E-cadherin pathway and poor patient outcome in non-small-cell lung cancer.
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Wu, D-W, Lee, M-C, Wang, J, Chen, C-Y, Cheng, Y-W, and Lee, H
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P53 protein , *RNA helicase , *CADHERINS , *UBIQUITIN ligases , *LUNG cancer & genetics , *GENETIC mutation , *TUMOR proteins - Abstract
P53 inactivation by p53 mutation and E6 oncoprotein has a crucial role in human carcinogenesis. DDX3 has been shown to be a target of p53. In this study, we hypothesized that DDX3 loss by p53 inactivation may promote tumor malignancy and poor patients' outcome. Mechanically, DDX3 loss by p53 knockdown and E6 overexpression was observed in A549 lung cancer cells. Conversely, DDX3 expression was markedly elevated by wild-type (WT) p53 ectopic expression in p53-null H1299 cells, E6-knockdown TL-1 lung cancer and SiHa cervical cancer cells. Interestingly, DDX3 loss promotes soft-agar growth and invasive capability; however, both capabilities were suppressed by DDX3 overexpression. We next expected that DDX3 loss might result in Slug-suppressed E-cadherin expression via decreased MDM2-mediated Slug degradation. As expected, MDM2 transcription is suppressed by DDX3 loss via decreased SP1 binding activity to the MDM2 promoter. Consequently, Slug expression was elevated by the reduction of MDM2 because of DDX3 loss, and E-cadherin expression was suppressed by Slug. Consistent observations in the correlation of DDX3 loss with MDM2, Slug and E-cadherin were seen in lung tumors from lung cancer patients. In addition, patients with low-DDX3 tumors had poorer survival and relapse than patients with high-DDX3 tumors. In conclusion, we suggest that DDX3 loss by p53 inactivation via MDM2/Slug/E-cadherin pathway promotes tumor malignancy and poor patient outcome. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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- View/download PDF
120. Perinatal outcomes in euploid pregnancies with 'double-positive' first trimester prenatal screening for trisomy 18 and 21.
- Author
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Yee, L M, Valderramos, S G, Pena, S, Cheng, Y W, and Bianco, K
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DOWN syndrome , *CHROMOSOME abnormalities , *LONGITUDINAL method , *FIRST trimester of pregnancy , *PRENATAL diagnosis , *RESEARCH funding , *RETROSPECTIVE studies , *CASE-control method , *DESCRIPTIVE statistics , *PREVENTION - Abstract
Objective:The objective of this study was to investigate whether women who screened positive for both trisomy 18 (T18) and trisomy 21 (T21) yet had euploid karyotypes were at increased risk for adverse pregnancy outcomes.Study Design:This was a retrospective cohort study of women who had first trimester aneuploidy screening. Double-positive subjects had risks greater than screening cutoffs for T21 and T18 and confirmed euploid karyotypes. Singleton subjects were matched 1:2 by maternal age to controls with normal screening. Perinatal outcomes were investigated using t-tests and χ2-tests; statistical significance was set at P<0.05.Result:Of 9733 women who had first trimester screening, 33 euploid pregnancies screened positive for both T21 and T18. Compared with controls, these study subjects were more likely to have abnormalities identified by prenatal ultrasounds, including renal, fetal membrane and fluid, as well as multiple anomalies (P=0.01). In addition, double-positive subjects had a lower mean gestational age at birth (P=0.02) and lower mean birth weight (P=0.03) than controls. Maternal outcomes were not significantly different.Conclusion:Pregnancies with double false-positive first trimester aneuploidy screening were associated with pregnancy/fetal abnormalities. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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121. Osteopontin regulates anabolic effect in human menopausal osteoporosis with intermittent parathyroid hormone treatment.
- Author
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Chiang, T.-I., Chang, I.-C., Lee, H.-S., Lee, H., Huang, C.-H., and Cheng, Y.-W.
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OSTEOPOROSIS prevention , *ANALYSIS of variance , *BIOMARKERS , *BLOOD testing , *COMBINATION drug therapy , *COMPUTER software , *CONFIDENCE intervals , *CYTOKINES , *ENZYME-linked immunosorbent assay , *OSTEOPOROSIS , *PARATHYROID hormone , *X-ray densitometry in medicine , *PILOT projects , *DATA analysis , *EQUIPMENT & supplies , *BONE density - Abstract
Summary: In this pilot study, we demonstrated that women with osteopontin (OPN) over-expression show less resistance to postmenopausal osteoporosis than women with normal OPN levels. We hypothesized that the levels of plasma OPN could be used as a treatment indicator for intermittent parathyroid hormone (PTH)-treated menopausal osteoporosis. We demonstrated that plasma OPN levels could be used as a biomarker for early treatment response. Introduction: Animal studies indicate that OPN-deficient mice are resistant to ovariectomy induced osteoporosis. Our pilot study also demonstrated women with OPN over expression may show less resistance to postmenopausal osteoporosis. The role of plasma OPN in PTH1-34-treated osteoporosis remains unclear. Methods: From September 2005 to September 2006, 31 menopausal women over 45 years of age with severe osteoporosis were enrolled in our study. Subjects were treated with PTH1-34 subcutaneously at a dose of 20 μg/day. Plasma OPN levels and BMD of the lumbar spine and hip were measured using ELISA and dual-energy X-ray absorptiometry at baseline, 3, 6, and 9 months. Response to the treatment was assessed by the sequential change in bone mineral density and OPN expression using a general linear mixed model. Results: The plasma OPN decreased sequentially and significantly throughout the 9-month treatment course from 20.75 ± 5.36 to 11.2 ± 4.37 ng/ml ( p < 0.001). The sequential improvement in the T-score and Z-score was significant in the lumbar spine but not in the hip area. In the lumbar spine, when the plasma OPN decreased by 1 ng/ml the T-score increased by 0.0406 and the Z-score increased by 0.0572 of lumbar spine. Conclusion: OPN levels are related to the anabolic effect of PTH in human postmenopausal osteoporosis. Plasma OPN levels could be used as a biomarker for early treatment response. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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122. Increased serum osteopontin is a risk factor for osteoporosis in menopausal women.
- Author
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Chang, I.-C., Chiang, T.-I., Yeh, K.-T., Lee, H., and Cheng, Y.-W.
- Subjects
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OSTEOPOROSIS in women , *OSTEOPOROSIS genetics , *BONE density , *OSTEOPONTIN , *ESTROGEN , *GENE expression , *LABORATORY mice - Abstract
Osteopontin (OPN)-deficient mice are resistant to ovariectomy-induced osteoporosis. Therefore, we hypothesized that women with OPN overexpression may show less resistance to postmenopausal osteoporosis. In this study, we first demonstrated that serum OPN levels could be used as a biomarker for the early diagnosis of osteoporosis in postmenopausal women. Animal studies indicate that OPN-deficient mice are resistant to ovariectomy-induced osteoporosis. From 2004 to 2006, 124 women over the age of 45 were enrolled in a menopausal group, while another 95 women, from 25 to 45 years of age with regular menstruation, were enrolled into a childbearing age group. The serum concentrations of OPN were calculated using the enzyme-link immunosorbent assay method, and bone mineral densities were determined with dual energy X-ray absorptiometry. Serum OPN levels had a significant positive correlation with age (menopausal group, p < 0.0001) and a negative correlation with body weight, height, hip bone mineral density, and T-scores in the menopausal group. In contrast, there was a positive correlation with the E2 concentration and height, but there was no significant association with the above variables in the childbearing age group. Additionally, high serum OPN levels (>14.7 ng/ml) was a significant risk factor causing menopausal osteoporosis (odds ratio = 2.96, 95% confidence interval, 1.055–8.345). Serum OPN levels could be used as a biomarker for the early diagnosis of osteoporosis in postmenopausal women. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
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123. The association between interdelivery interval and adverse perinatal outcomes in a diverse US population.
- Author
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Yee LM, Truong YN, Caughey AB, and Cheng YW
- Subjects
- Adult, Apgar Score, Confounding Factors, Epidemiologic, Female, Humans, Infant, Newborn, Infant, Small for Gestational Age, Logistic Models, Male, Maternal Age, Multivariate Analysis, Pregnancy, Registries, Retrospective Studies, United States epidemiology, Young Adult, Birth Intervals statistics & numerical data, Cesarean Section statistics & numerical data, Pregnancy Outcome epidemiology, Premature Birth epidemiology
- Abstract
Objective: The objective of this study was to investigate the association between interdelivery interval (IDI) and subsequent perinatal outcomes in a large population-based cohort., Study Design: Retrospective cohort study of primiparous women with singleton gestations giving birth in the US in 2011 to 2012. IDI was defined as the time between last live birth and index live birth. IDI was categorized as 4 to 17 months, 18 to 36 months (referent), 37 to 60 months and >60 months. Statistical comparisons were made using chi-square tests and multivariable logistic regression models to control for confounding. Covariates included maternal age, prior preterm birth, prior cesarean and medical comorbidities., Results: Of the 1 964 523 women meeting study criteria, 9.0% had an IDI of 4 to 17 months, 39.7% 18 to 36 months, 26.8% 37 to 60 months and 24.5% >60 months. Short IDI was associated with preterm delivery (<37 weeks; 13.8 vs 8.8%, (adjusted odds ratio (aOR) 1.51, 95% confidence interval (CI) 1.48 to 1.53)) and adverse perinatal outcomes including low 5-min Apgar, small for gestational age (SGA) status and neonatal intensive care unit (NICU) admission. Women with long IDI had a higher risk of induction of labor, cesarean delivery, chorioamnionitis, maternal ICU admission, preterm delivery and SGA status, 5-min Apgar score <4, and NICU admission., Conclusions: Compared with women with 18 to 36 month IDIs, women with either shorter or very long IDIs were at an increased risk of adverse maternal and neonatal outcomes.
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- 2016
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124. Transcriptome analysis and anthocyanin-related genes in red leaf lettuce.
- Author
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Zhang YZ, Xu SZ, Cheng YW, Ya HY, and Han JM
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- Anthocyanins genetics, Base Sequence, Databases, Protein, Lactuca genetics, Microsatellite Repeats, Molecular Sequence Annotation, Molecular Sequence Data, Plant Leaves genetics, Seedlings genetics, Seedlings metabolism, Anthocyanins biosynthesis, Genes, Plant, Lactuca metabolism, Plant Leaves metabolism, Transcriptome
- Abstract
This study aimed to analyze the transcriptome profile of red lettuce and identify the genes involved in anthocyanin accumulation. Red leaf lettuce is a popular vegetable and popular due to its high anthocyanin content. However, there is limited information available about the genes involved in anthocyanin biosynthesis in this species. In this study, transcriptomes of 15-day-old seedlings and 40-day-old red lettuce leaves were analyzed using an Illuminia HiseqTM 2500 platform. A total of 10.6 GB clean data were obtained and de novo assembled into 83,333 unigenes with an N50 of 1067. After annotation against public databases, 51,850 unigene sequences were identified, among which 46,087 were annotated in the NCBI non-redundant protein database, and 41,752 were annotated in the Swiss-Prot database. A total of 9125 unigenes were mapped into 163 pathways using the Kyoto Encyclopedia of Genes and Genomes database. Thirty-four structural genes were found to cover the main steps of the anthocyanin pathway, including chalcone synthase, chalcone isomerase, flavanone 3-hydroxylase, flavonoid 3'-hydroxylase, flavonoid 3',5'-hydroxylase, dihydroflavonol 4-reductase, and anthocyanidin synthase. Seven MYB, three bHLH, and two WD40 genes, considered anthocyanin regulatory genes, were also identified. In addition, 3607 simple sequence repeat (SSR) markers were identified from 2916 unigenes. This research uncovered the transcriptomic characteristics of red leaf lettuce seedlings and mature plants. The identified candidate genes related to anthocyanin biosynthesis and the detected SSRs provide useful tools for future molecular breeding studies.
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- 2016
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125. Identification of heat shock proteins via transcriptome profiling of tree peony leaf exposed to high temperature.
- Author
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Zhang YZ, Cheng YW, Ya HY, Han JM, and Zheng L
- Subjects
- Databases, Nucleic Acid, Databases, Protein, Gene Expression Profiling, High-Throughput Nucleotide Sequencing methods, Microsatellite Repeats, Molecular Sequence Annotation, Plant Leaves genetics, Temperature, Heat-Shock Proteins genetics, Paeonia genetics
- Abstract
The tree peony leaf is an important vegetative organ that is sensitive to abiotic stress and particularly to high temperature. This sensitivity affects plant growth and restricts tree peony distribution. However, the transcriptomic information currently available on the peony leaf in public databases is limited. In this study, we sequenced the transcriptomes of peony leaves subjected to high temperature using the Illumina HiSeq TM 2000 platform. We performed de novo assembly of 93,714 unigenes (average length of 639.7 bp). By searching the public databases, 22,323 unigenes and 13,107 unigenes showed significant similarities with proteins in the NCBI non-redundant protein database and SWISS-PROT database (E-value < 1e-5), respectively. We assigned 17,340 unigenes to Gene Ontology categories, and we assigned 7618 unigenes to clusters of orthologous groups for eukaryotic complete genomes. By searching the Kyoto Encyclopedia of Genes and Genomes Pathway database, 8014 unigenes were assigned to 6 main categories, including 290 KEGG pathways. To advance research on improving thermotolerance, we identified 24 potential heat shock protein genes with complete open reading frames from the transcriptomic sequences. This is the first study to characterize the leaf transcriptome of tree peony leaf using high-throughput sequencing. The information obtained from the tree peony leaf is valuable for gene discovery, and the identified heat shock protein genes can be used to improve plant stress-tolerance.
- Published
- 2015
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126. The MZF1/c-MYC axis mediates lung adenocarcinoma progression caused by wild-type lkb1 loss.
- Author
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Tsai LH, Wu JY, Cheng YW, Chen CY, Sheu GT, Wu TC, and Lee H
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- AMP-Activated Protein Kinase Kinases, Adenocarcinoma mortality, Adenocarcinoma of Lung, Cell Movement, Disease Progression, Humans, Lung Neoplasms mortality, Neoplasm Invasiveness, Promoter Regions, Genetic, Protein Serine-Threonine Kinases genetics, Adenocarcinoma pathology, Kruppel-Like Transcription Factors physiology, Lung Neoplasms pathology, Protein Serine-Threonine Kinases physiology, Proto-Oncogene Proteins c-myc physiology
- Abstract
Liver kinase B1 (LKB1) loss in lung adenocarcinoma is commonly caused by genetic mutations, but these mutations rarely occur in Asian patients. We recently reported wild-type LKB1 loss via the alteration of NKX2-1/p53-axis-promoted tumor aggressiveness and predicted poor outcomes in cases of lung adenocarcinoma. The mechanistic action of wild-type LKB1 loss within tumor progression remains unknown. The suppression of MYC by LKB1 controls epithelial organization; therefore, we hypothesize that MYC expression can be increased via wild-type LKB1 loss and promotes tumor progression. Here, MYC transcription is upregulated by LKB1-loss-mediated MZF1 expression. The wild-type LKB1-loss-mediated MZF1/MYC axis is responsible for soft-agar growth, migration and invasion in lung adenocarcinoma cells. Moreover, wild-type LKB1 loss-induced cell invasiveness was markedly suppressed by MYC inhibitors (10058-F4 and JQ1). Patients with low-LKB1/high-MZF1 or low-LKB1/high-MYC tumors have shorter overall survival and relapse-free-survival periods than patients with high-LKB1/low-MZF1 or high-LKB1/low-MYC tumors. In summary, MZF1-mediated MYC expression may promote tumor progression, resulting in poor outcomes in cases of lung adenocarcinoma with low-wild-type-LKB1 tumors.
- Published
- 2015
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127. Phenotypic heterogeneity in monogenic diabetes: the clinical and diagnostic utility of a gene panel-based next-generation sequencing approach.
- Author
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Alkorta-Aranburu G, Carmody D, Cheng YW, Nelakuditi V, Ma L, Dickens JT, Das S, Greeley SAW, and Del Gaudio D
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- Child, Preschool, Consanguinity, Diabetes Mellitus, Type 2 diagnosis, Diabetes Mellitus, Type 2 genetics, Female, Humans, Infant, Male, Phenotype, United States, Diabetes Mellitus diagnosis, Diabetes Mellitus genetics, Genetic Testing, High-Throughput Nucleotide Sequencing methods, Mutation, Sequence Analysis, DNA methods
- Abstract
Single gene mutations that primarily affect pancreatic β-cell function account for approximately 1-2% of all cases of diabetes. Overlapping clinical features with common forms of diabetes makes diagnosis of monogenic diabetes challenging. A genetic diagnosis often leads to significant alterations in treatment, allows better prediction of disease prognosis and progression, and has implications for family members. Currently, genetic testing for monogenic diabetes relies on selection of appropriate individual genes for analysis based on the availability of often-limited phenotypic information, decreasing the likelihood of making a genetic diagnosis. We thus developed a targeted next-generation sequencing (NGS) assay for the detection of mutations in 36 genes known to cause monogenic forms of diabetes, including transient or permanent neonatal diabetes mellitus (TNDM or PNDM), maturity-onset diabetes of the young (MODY) and rare syndromic forms of diabetes. A total of 95 patient samples were analyzed: 19 with known causal mutations and 76 with a clinically suggestive phenotype but lacking a genetic diagnosis. All previously identified mutations were detected, validating our assay. Pathogenic sequence changes were identified in 19 out of 76 (25%) patients: 7 of 32 (22%) NDM cases, and 12 of 44 (27%) MODY cases. In 2 NDM patients the causal mutation was not expected as consanguinity was not reported and there were no clinical features aside from diabetes. A 3 year old patient with NDM diagnosed at 3 months of age, who previously tested negative for INS, KCNJ11 and ABCC8 mutations, was found to carry a novel homozygous mutation in EIF2AK3 (associated with Wolcott-Rallison syndrome), a gene not previously suspected because consanguinity, delayed growth, abnormal bone development and hepatic complications had not been reported. Similarly, another infant without a history of consanguinity was found to have a homozygous GCK mutation causing PNDM at birth. This study demonstrates the effectiveness of multi-gene panel analysis in uncovering molecular diagnoses in patients with monogenic forms of diabetes., (Published by Elsevier Inc.)
- Published
- 2014
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128. LKB1 loss by alteration of the NKX2-1/p53 pathway promotes tumor malignancy and predicts poor survival and relapse in lung adenocarcinomas.
- Author
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Tsai LH, Chen PM, Cheng YW, Chen CY, Sheu GT, Wu TC, and Lee H
- Subjects
- AMP-Activated Protein Kinase Kinases, Adenocarcinoma mortality, Adenocarcinoma pathology, Adenocarcinoma of Lung, Aged, Aged, 80 and over, Cell Line, Tumor, Female, Gene Expression Regulation, Neoplastic, Humans, Lung Neoplasms mortality, Lung Neoplasms pathology, Lymphatic Metastasis, Male, Middle Aged, Mutation, Neoplasm Recurrence, Local, Neoplasm Staging, Prognosis, Protein Serine-Threonine Kinases genetics, RNA, Messenger genetics, RNA, Messenger metabolism, Thyroid Nuclear Factor 1, Transcription, Genetic, Tumor Burden, Tumor Suppressor Protein p53 genetics, Adenocarcinoma genetics, Adenocarcinoma metabolism, Lung Neoplasms genetics, Lung Neoplasms metabolism, Nuclear Proteins metabolism, Protein Serine-Threonine Kinases deficiency, Signal Transduction, Transcription Factors metabolism, Tumor Suppressor Protein p53 metabolism
- Abstract
LKB1 loss is a frequent homozygous deletion and/or gene mutation found in lung adenocarcinomas. However, few cases of LKB1 loss by either deletion or mutation are seen in Asian patients. Our preliminary data showed that LKB1 loss was associated with p53 mutation in lung tumors from Taiwanese adenocarcinoma patients and p53 transcription is directly regulated by NKX2-1. Therefore, we hypothesized that LKB1 loss could occur due to aberration of p53 regulation mediated by NKX2-1. In the present study, 16 lung adenocarcinoma cell lines were investigated to determine if LKB1 transcription could be deregulated by NKX2-1-mediated p53 aberration. Mechanistic studies indicated that LKB1 was directly upregulated by p53 and that NKX2-1-mediated p53 expression may positively regulate LKB1 expression in p53 wild-type cells. However, in p53-mutated cells, LKB1 transcription was deregulated by NKX2-1 via suppression of SP1 binding onto the LKB1 promoter. Therefore, the action of the NKX2-1/p53 pathway on LKB1 loss differed in p53 wild-type versus p53-mutated cells. As expected, soft-agar growth and invasion capability was significantly reduced by ectopic expression of NKX2-1 in p53 wild-type cells, but it was markedly elevated by silencing NKX2-1 in p53-mutated cells. Similar reciprocal observations were also seen in lung tumors from lung adenocarcinoma patients with either wild-type or mutated p53 tumors. Cox regression analysis showed that patients with low-LKB1 tumors had poorer overall survival (OS) and relapse-free survival (RFS) when compared with patients with high-LKB1 tumors. In p53 wild-type patients, shorter OS and RFS periods were predicted for low-NKX2-1/low-LKB1 tumors than for high-NKX2-1/high-LKB1 tumors. In patients with p53-mutated tumors, poorer OS and RFS were predicted for high-NKX2-1/low-LKB1 tumors than for low-NKX2-1/high-LKB1 tumors. In summary, losses of LKB1 at the transcriptional level by altered activity of the NKX2-1/p53 pathway may promote tumor malignancy and poor patient outcome.
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- 2014
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129. Large duplication in MTM1 associated with myotubular myopathy.
- Author
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Amburgey K, Lawlor MW, Del Gaudio D, Cheng YW, Fitzpatrick C, Minor A, Li X, Aughton D, Das S, Beggs AH, and Dowling JJ
- Subjects
- Fatal Outcome, Genetic Testing, Humans, Infant, Infant, Newborn, Male, Gene Duplication, Myopathies, Structural, Congenital genetics, Protein Tyrosine Phosphatases, Non-Receptor genetics
- Abstract
Myotubular myopathy is a subtype of centronuclear myopathy with X-linked inheritance and distinctive clinical and pathologic features. Most boys with myotubular myopathy have MTM1 mutations. In remaining individuals, it is not clear if disease is due to an undetected alteration in MTM1 or mutation of another gene. We describe a boy with myotubular myopathy but without mutation in MTM1 by conventional sequencing. Array-CGH analysis of MTM1 uncovered a large MTM1 duplication. This finding suggests that at least some unresolved cases of myotubular myopathy are due to duplications in MTM1, and that array-CGH should be considered when MTM1 sequencing is unrevealing., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2013
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130. Impending macrosomia: will induction of labour modify the risk of caesarean delivery?
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Cheng YW, Sparks TN, Laros RK Jr, Nicholson JM, and Caughey AB
- Subjects
- Adult, Chi-Square Distribution, Cohort Studies, Female, Fetal Weight, Humans, Logistic Models, Pregnancy, Pregnancy Outcome, Pregnancy Trimester, Third, Prevalence, Retrospective Studies, Risk Assessment, Risk Factors, United States epidemiology, Cesarean Section statistics & numerical data, Fetal Macrosomia prevention & control, Labor, Induced statistics & numerical data
- Abstract
Objective: To compare the annual incidence rates of caesarean delivery between induction of labour and expectant management in the setting of macrosomia., Design: This is a retrospective cohort study., Setting: Deliveries in the USA in 2003., Population: Singleton births of macrosomic neonates to low-risk nulliparous women at 39 weeks of gestation and beyond., Methods: Women who had induction of labour at 39 weeks of gestation with a neonatal birthweight of 4000 ± 125 g (3875-4125 g) were compared with women who delivered (either induced or spontaneous labour) at 40, 41 or 42 weeks (i.e. expectant management), assuming an intrauterine fetal weight gain of 200 g per additional week of gestation. Similar comparisons were made at 40 and 41 weeks of gestation. Chi-square test and multivariable logistic regression analysis were used for statistical comparison., Main Outcome Measures: Method of delivery, 5-minute Apgar scores, neonatal injury., Results: There were 132,112 women meeting the study criteria. In women whose labours were induced at 39 weeks and who delivered a neonate with a birthweight of 4000 ± 125 g, the frequency of caesarean was lower compared with women who delivered at a later gestational age (35.2% versus 40.9%; adjusted OR 1.25, 95% CI 1.17-1.33). This trend was maintained at both 40 weeks (36.1% versus 42.6%; adjusted OR 1.31, 95% CI 1.23-1.40) and 41 weeks (38.9% versus 41.8%; adjusted OR 1.16, 95% CI 1.06-1.28) of gestation., Conclusions: In the setting of known birthweight, it appears that induction of labour may reduce the risk of caesarean delivery. Future research should concentrate on clinical and radiological methods to better estimate birthweight to facilitate improved clinical care. These findings deserve examination in a large, prospective, randomised trial., (© 2012 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2012 RCOG.)
- Published
- 2012
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131. Effect of maternal weight on postterm delivery.
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Halloran DR, Cheng YW, Wall TC, Macones GA, and Caughey AB
- Subjects
- Adult, Body Mass Index, Cohort Studies, Female, Humans, Infant, Newborn, Logistic Models, Maternal Welfare, Multivariate Analysis, Odds Ratio, Predictive Value of Tests, Pregnancy, Pregnancy Complications diagnosis, Pregnancy Outcome, Retrospective Studies, Risk Assessment, Young Adult, Delivery, Obstetric methods, Gestational Age, Infant, Postmature, Pregnancy Complications epidemiology, Weight Gain
- Abstract
Objective: Examine the effect of prepregnancy weight and maternal gestational weight gain on postterm delivery rates., Study Design: This was a retrospective cohort study of term, singleton births (N=375 003). We performed multivariable analyses of the association between postterm pregnancy and both prepregnancy body mass index (BMI) and maternal weight gain., Result: Prolonged or postterm delivery (41 or 42 weeks) was increasingly common with increasing prepregnancy weight (P<0.001) and increasing maternal weight gain (P<0.001). Underweight women were 10% less likely to deliver postterm than normal weight women who gain within the recommendations (adjusted odds ratio 0.90 (95% confidence interval 0.83, 0.97)). Overweight women who gain within or above recommendations were also at increased risk of a 41-week delivery. Finally, obese women were at increased risk of a 41-week delivery with increasing risk with increasing weight (below, within and above recommendations adjusted odds ratios 1.19, 1.21, and 1.27, respectively)., Conclusion: Elevated prepregnancy weight and maternal weight gain both increase the risk of a postterm delivery. Although most women do not receive preconceptional care, restricting weight gain to the within the recommended range can reduce the risk of postterm pregnancy in normal, overweight and obese women.
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- 2012
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132. Perinatal morbidity associated with late preterm deliveries compared with deliveries between 37 and 40 weeks of gestation.
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Cheng YW, Kaimal AJ, Bruckner TA, Halloran DR, and Caughey AB
- Subjects
- Anti-Bacterial Agents therapeutic use, Apgar Score, Cohort Studies, Female, Humans, Hyaline Membrane Disease epidemiology, Infant, Newborn, Infant, Premature, Intensive Care Units, Neonatal statistics & numerical data, Logistic Models, Odds Ratio, Patient Admission statistics & numerical data, Pregnancy, Respiration, Artificial statistics & numerical data, Retrospective Studies, Sepsis drug therapy, Sepsis epidemiology, United States epidemiology, Gestational Age, Infant, Premature, Diseases epidemiology, Premature Birth epidemiology
- Abstract
Objective: To estimate the risk of short-term complications in neonates born between 34 and 36 weeks of gestation., Design: This is a retrospective cohort study., Setting: Deliveries in 2005 in the USA., Population: Singleton live births between 34 and 40 weeks of gestation., Methods: Gestational age was subgrouped into 34, 35, 36 and 37-40 completed weeks of gestation. Statistical comparisons were performed using chi-square test and multivariable logistic regression models, with 37-40 weeks of gestation designated as referent., Main Outcome Measures: Perinatal morbidities, including 5-minute Apgar scores, hyaline membrane disease, neonatal sepsis/antibiotics use, and admission to the intensive care unit., Results: In all, 175,112 neonates were born between 34 and 36 weeks in 2005. Compared with neonates born between 37 and 40 weeks, neonates born at 34 weeks had higher odds of 5-minute Apgar <7 (adjusted odds ratio [aOR] 5.51, 95% CI 5.16-5.88), hyaline membrane disease (aOR 10.2, 95% CI 9.44-10.9), mechanical ventilation use >6 hours (aOR 9.78, 95% CI 8.99-10.6) and antibiotic use (aOR 9.00, 95% CI 8.43-9.60). Neonates born at 35 weeks were similarly at risk of morbidity, with higher odds of 5-minute Apgar <7 (aOR 3.42, 95% CI 3.23-3.63), surfactant use (aOR 3.74, 95% CI 3.21-4.22), ventilation use >6 hours (aOR 5.53, 95% CI 5.11-5.99) and neonatal intensive-care unit admission (aOR 11.3, 95% CI 11.0-11.7). Neonates born at 36 weeks remain at higher risk of morbidity compared with deliveries at 37-40 weeks of gestation., Conclusions: Although the risk of undesirable neonatal outcomes decreases with increasing gestational age, the risk of neonatal complications in late preterm births remains higher compared with infants delivered at 37-40 weeks of gestation., (© 2011 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2011 RCOG.)
- Published
- 2011
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133. Medical waste generation in selected clinical facilities in Taiwan.
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Cheng YW, Li KC, and Sung FC
- Subjects
- Medical Waste analysis, Medical Waste classification, Taiwan, Health Facilities statistics & numerical data, Medical Waste statistics & numerical data
- Abstract
This study investigated the type and amount of medical waste generated from small clinical facilities in Taiwan. We sampled 200 small medical establishments, with few or no patient beds, to survey the wastes generated and disposed. The surveyed medical facilities consisted of four groups including private clinics, medical laboratories, blood centers and public clinics. Private clinics providing surgical, dental, obstetrical, and dialysis services were included in this survey because they may generate higher amounts of infectious waste than other specialties. The overall mean general waste production rate was 3.97 kg/bed/day (or 0.075 kg/patient/day) at all the surveyed facilities, higher than that obtained from larger hospitals in Taiwan, which ranged from 2.41 to 3.26 kg/bed/day. The highest amount of infectious wastes generated among the four groups of facilities were from blood centers (3.14 kg/bed/day), followed by private clinics, medical laboratories and public clinics (1.91, 1.07, and 0.053 kg/bed/day, respectively). The overall average was 2.08 kg/bed/day. This study suggests that the waste generated at small medical facilities ranged widely., (2010 Elsevier Ltd. All rights reserved.)
- Published
- 2010
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134. Subcellular localization of apurinic endonuclease 1 promotes lung tumor aggressiveness via NF-kappaB activation.
- Author
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Wu HH, Cheng YW, Chang JT, Wu TC, Liu WS, Chen CY, and Lee H
- Subjects
- Animals, Cell Nucleus metabolism, Cyclooxygenase 2 biosynthesis, Cytoplasm metabolism, DNA-(Apurinic or Apyrimidinic Site) Lyase analysis, Female, Humans, Lung Neoplasms enzymology, Mice, Mice, Inbred BALB C, Neoplasm Metastasis, Prognosis, Transcription Factor RelA analysis, Tumor Suppressor Protein p53 metabolism, DNA-(Apurinic or Apyrimidinic Site) Lyase physiology, Lung Neoplasms pathology, NF-kappa B physiology
- Abstract
Apurinic endonuclease 1 (Ape1) is not only involved in base excision repair, but also activates some transcriptional factors through its redox activity. However, which subcellular localization of Ape1 is involved in the activation of transcriptional factor remains unclear. We first observed that Cox-2 expression was associated with cytoplasmic Ape1 expression in lung tumors and cancer cell lines. We thus hypothesize that nuclear factor (NF)-kappaB is activated by cytoplasmic Ape1 to cause Cox-2 expression. Herein, we generated cytoplasmic and nuclear Ape1 in Ape1-knockdown lung cancer cells by exogenous expression of Ape1 containing various deletions and/or mutations of the nuclear localization sequence. It was observed that cytoplasmic Ape1, but not nuclear Ape1, induced Cox-2 expression through NF-kappaB activation. NF-kappaB activation by cytoplasmic Ape1 was diminished by the Ape1 redox activity inhibitor resveratrol. Cells expressing cytoplasmic Ape1 exhibited tumor progression and metastasis in vitro and in vivo as xenografts, but cells expressing nuclear Ape1 did not. Patients with tumors containing elevated cytoplasmic Ape1 had a poor prognosis and a 3.722-fold risk of tumor recurrence and/or metastasis. Cytoplasmic Ape1 could therefore enhance lung tumor malignancy through NF-kappaB activation, suggesting that combination of cisplatin and specific redox inhibitor could improve chemotherapeutic response in patients with tumors containing elevated cytoplasmic Ape1.
- Published
- 2010
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135. Medical waste production at hospitals and associated factors.
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Cheng YW, Sung FC, Yang Y, Lo YH, Chung YT, and Li KC
- Subjects
- Health Facility Size, Insurance, Health, Taiwan, Hospitals standards, Medical Waste statistics & numerical data
- Abstract
This study was conducted to evaluate the quantities of medical waste generated and the factors associated with the generation rate at medical establishments in Taiwan. Data on medical waste generation at 150 health care establishments were collected for analysis in 2003. General medical waste and infectious waste production at these establishments were examined statistically with the potential associated factors. These factors included the types of hospital and clinic, reimbursement payment by National Health Insurance, total number of beds, bed occupancy, number of infectious disease beds and outpatients per day. The average waste generation rates ranged from 2.41 to 3.26kg/bed/day for general medical wastes, and 0.19-0.88kg/bed/day for infectious wastes. The total average quantity of infectious wastes generated was the highest from medical centers, or 3.8 times higher than that from regional hospitals (267.8 vs. 70.3Tons/yr). The multivariate regression analysis was able to explain 92% of infectious wastes and 64% of general medical wastes, with the amount of insurance reimbursement and number of beds as significant prediction factors. This study suggests that large hospitals are the major source of medical waste in Taiwan. The fractions of medical waste treated as infectious at all levels of healthcare establishments are much greater than that recommended by the USCDC guidelines.
- Published
- 2009
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136. Comprehensive characterization of indoor airborne bacterial profile.
- Author
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Chan PL, Yu PH, Cheng YW, Chan CY, and Wong PK
- Subjects
- Humans, Air Microbiology, Air Pollution, Indoor analysis, Bacteria isolation & purification, Environmental Monitoring, Restaurants
- Abstract
This is the first detailed characterization of the airborne bacterial profiles in indoor environments. Two restaurants were selected for this study. Fifteen genera of bacteria were isolated from each restaurant and identified by three different bacterial identification systems including MIDI, Biolog and Riboprinter. The dominant bacteria of both restaurants were Gram-positive bacteria in which Micrococcus and Bacillus species were the most abundant. Most bacteria identified were representative species of skin and respiratory tract of human, and soil. Although the bacterial levels in these two restaurants were below the limit of the Hong Kong Indoor Air Quality Objective (HKIAQO) Level 1 standard (i.e., < 500 cfu/m3), the majority of these bacteria were opportunistic pathogens. These results suggested that the identity of airborne bacteria should also be included in the IAQ to ensure there is a safety guideline for the public.
- Published
- 2009
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137. Do-not-resuscitate decision: the attitudes of medical and non-medical students.
- Author
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Sham CO, Cheng YW, Ho KW, Lai PH, Lo LW, Wan HL, Wong CY, Yeung YN, Yuen SH, and Wong AY
- Subjects
- Adult, Age Factors, Aged, Aged, 80 and over, Attitude to Death, Ethics, Professional, Female, Hong Kong, Humans, Male, Middle Aged, Patient Advocacy, Practice Guidelines as Topic, Resuscitation Orders psychology, Surveys and Questionnaires, Attitude of Health Personnel, Decision Making, Resuscitation Orders ethics, Social Values, Students, Medical psychology
- Abstract
Objectives: To study the attitudes of both medical and non-medical students towards the do-not-resuscitate (DNR) decision in a university in Hong Kong, and the factors affecting their attitudes., Methods: A questionnaire-based survey conducted in the campus of a university in Hong Kong. Preferences and priorities of participants on cardiopulmonary resuscitation in various situations and case scenarios, experience of death and dying, prior knowledge of DNR and basic demographic data were evaluated., Results: A total of 766 students participated in the study. There were statistically significant differences in their DNR decisions in various situations between medical and non-medical students, clinical and preclinical students, and between students who had previously experienced death and dying and those who had not. A prior knowledge of DNR significantly affected DNR decision, although 66.4% of non-medical students and 18.7% of medical students had never heard of DNR. 74% of participants from both medical and non-medical fields considered the patient's own wish as the most important factor that the healthcare team should consider when making DNR decisions. Family wishes might not be decisive on the choice of DNR., Conclusions: Students in medical and non-medical fields held different views on DNR. A majority of participants considered the patient's own wish as most important in DNR decisions. Family wishes were considered less important than the patient's own wishes.
- Published
- 2007
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138. Disinfection of Legionella pneumophila by photocatalytic oxidation.
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Cheng YW, Chan RC, and Wong PK
- Subjects
- Antigens, Bacterial metabolism, Catalysis, Cell Membrane metabolism, Disinfection instrumentation, Fatty Acids analysis, Lipid Peroxidation, Microscopy, Electron, Scanning, Microscopy, Electron, Transmission, Disinfection methods, Legionella pneumophila classification, Legionella pneumophila growth & development, Legionella pneumophila metabolism, Legionnaires' Disease prevention & control, Oxidation-Reduction, Photolysis
- Abstract
Photocatalytic oxidation (PCO) was proven to be efficacious in the inactivation of Legionella pneumophila serogroup 1 Strains 977, 1009, 1014 and ATCC 33153. The local (Strains 997, 1009 and 1014) and ATCC (Strain 33153) strains showed sensitivity differences towards PCO. The inactivation mechanisms of PCO were investigated by transmission and scanning electron microscopy by which PCO was found to disintegrate the cells eventually. Before the disintegration, there was lipid peroxidation of outer and cytoplasmic membrane causing holes formation and leading to the entry of OH into the cells to oxidize the intracellular components. Fatty acid profile analysis found that the amount of saturated, 16-carbon branched-chain fatty acid, which is predominant in Legionella, decreased in the surviving populations from PCO. A relationship between the amount of this fatty acid and the PCO sensitivity of the tested strains was also observed. Mineralization of cells by PCO was proven by total organic carbon analysis.
- Published
- 2007
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139. Kawasaki disease in Hong Kong, 1994 to 2000.
- Author
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Ng YM, Sung RY, So LY, Fong NC, Ho MH, Cheng YW, Lee SH, Mak WC, Wong DM, Yam MC, Kwok KL, and Chiu WK
- Subjects
- Adolescent, Chi-Square Distribution, Child, Child, Preschool, Female, Hong Kong epidemiology, Humans, Incidence, Infant, Male, Retrospective Studies, Mucocutaneous Lymph Node Syndrome epidemiology
- Abstract
Objective: To describe the epidemiology, clinical characteristics, and management of Kawasaki disease in children in Hong Kong., Design: Retrospective survey of medical records from July 1994 to June 1997, and prospective data collection from July 1997 to June 2000., Setting: Hospitals with a paediatric unit in Hong Kong., Patients: Patients diagnosed with Kawasaki disease between July 1994 and June 2000 in public hospitals in Hong Kong., Main Outcome Measures: Incidence of Kawasaki disease and coronary artery aneurysm rates., Results: A total of 696 cases of Kawasaki disease were reported. There were 435 (62.5%) boys and 261 (37.5%) girls giving a male to female ratio of 1.7:1. The age ranged from 1 month to 15 years 5 months with a median of 1.7 years. Infants (<1 year) constituted the largest group of patients (223, 32.0%) and overall, 638 (91.7%) were younger than 5 years. Skin rash, conjunctivitis, and oral signs were among the principal clinical features present in over 80% of cases. Prominent cervical lymph nodes larger than 1.5 cm were less commonly found (24%). Coronary artery aneurysms or ectasia were present in 15.7% (109/696), 8.5% (59/696), and 5.0% (35/696) of patients at 2, 4, and 8 weeks, respectively. The incidence of Kawasaki disease per 100,000 children under 5 years was significantly higher in the prospective study period than in the retrospective period (39 vs 26, P<0.001)., Conclusion: The incidence of Kawasaki disease is high in Hong Kong and is 39 per 100,000 children below 5 years of age. The coronary artery aneurysm prevalence is 5%. Intravenous gamma-globulin and high-dose aspirin is the mainstay of treatment.
- Published
- 2005
140. Cholesterol-3-beta, 5-alpha, 6-beta-triol induced genotoxicity through reactive oxygen species formation.
- Author
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Cheng YW, Kang JJ, Shih YL, Lo YL, and Wang CF
- Subjects
- Animals, CHO Cells, Catalase pharmacology, Chromosome Aberrations, Cricetinae, Cricetulus, Mutagenicity Tests, Salmonella genetics, Superoxide Dismutase pharmacology, Cholestanols toxicity, Cholesterol analogs & derivatives, Cholesterol toxicity, DNA Damage, Ketocholesterols toxicity, Reactive Oxygen Species
- Abstract
The mutagenicity of oxysterols, cholesterol-3beta,5alpha,6beta-triol (alpha-Triol), 7-keto-cholesterol (7-Keto) and cholesterol-5alpha,6alpha-epoxide (alpha-Epox) were examined by the Ames method and chromosome aberration test in this study. Only alpha-Triol concentration-dependently caused an increase of bacterial revertants in the absence of metabolic activating enzymes (S9), but not 7-keto and alpha-Epox. The mutagenic effect of alpha-Triol was reduced by the addition of S9. On the other hand, although alpha-Triol significantly induced chromosome aberration in CHO-K1 cells with and without S9. However, the addition of S9 reduced the degree of abnormal structure chromosome compared to without S9 mix. Catalase and superoxide dismutase (SOD) inhibited alpha-Triol induced increase of revertants in Salmonella typhimurium and chromosome aberration frequency in CHO cells, suggesting that reactive oxygen species (ROS) might be involved in the genotoxic effect of alpha-Triol. Treatment with alpha-Triol increased the ROS production in CHO cells, which could be attenuated by catalase and SOD. Results in this study suggested, for the first time that alpha-Triol, causes genotoxic effect in an ROS-dependent manner.
- Published
- 2005
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141. The association of human papillomavirus 16/18 infection with lung cancer among nonsmoking Taiwanese women.
- Author
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Cheng YW, Chiou HL, Sheu GT, Hsieh LL, Chen JT, Chen CY, Su JM, and Lee H
- Subjects
- Female, Humans, Male, Middle Aged, Polymerase Chain Reaction, Sex Factors, Taiwan, Lung Neoplasms virology, Papillomaviridae, Papillomavirus Infections complications, Tumor Virus Infections complications
- Abstract
Lung cancer is the leading cause of cancer death in Taiwanese women since 1982. High lung cancer mortality ratio of male:female in Taiwan (2:1) was observed, although less than 10% of female lung cancer patients are smokers. Until now, the etiological factor remains unknown. We hypothesize that high-risk human papillomavirus (HPV) 16/18 may be associated with lung cancer development based on high prevalence of p53 negative immunostainings in female lung tumors compared with that of male lung tumors. In this study, 141 lung cancer patients and 60 noncancer control subjects were enrolled to examine whether HPV 16/18 DNA existed in lung tumor and normal tissues by nested PCR and in situ hybridization (ISH), respectively. The concordant detection of HPV 16 and 18 DNA between nested PCR and ISH method was 73 and 85.5%, respectively. Our data showed that 77 (54.6%) of 141 lung tumors had HPV 16/18 DNA compared with 16 (26.7%; P = 0.0005) of 60 noncancer control subjects. In addition, ISH data showed that HPV 16/18 DNA was uniformly located in lung tumor cells, but not in the adjacent nontumor cells. When study subjects were stratified by gender, age, and smoking status, nonsmoking female lung cancer patients who were older than 60 years old had significantly high prevalence of HPV 16/18 infection. The odds ratio of HPV 16/18 infection of nonsmoking female lung cancer patients is much higher at 10.12 (95% confidence interval, 3.88-26.38) compared with 1.98 (95% confidence interval, 0.84-4.76) of nonsmoking male lung cancer patients. This result strongly suggests that HPV infection is associated with lung cancer development of nonsmoking female lung cancer patients. The high prevalence of HPV 16/18 infection may explain to a certain extent why Taiwanese women nonsmokers had a higher lung cancer mortality rate.
- Published
- 2001
142. Non-templated addition of nucleotides to the 3' end of nascent RNA during RNA editing in Physarum.
- Author
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Cheng YW, Visomirski-Robic LM, and Gott JM
- Subjects
- Adenosine Triphosphatases genetics, Animals, Base Sequence, Cytidine Triphosphate metabolism, DNA-Directed RNA Polymerases metabolism, Electron Transport Complex IV genetics, Molecular Sequence Data, RNA Precursors metabolism, RNA, Messenger metabolism, RNA, Mitochondrial, Transcription, Genetic, Mitochondria genetics, Physarum genetics, RNA metabolism, RNA Editing, Ribonucleotides metabolism
- Abstract
RNAs in Physarum: mitochondria contain extra nucleotides that are not encoded by the mitochondrial genome, at least in the traditional sense. While it is known that insertion of non-encoded nucleotides is linked to RNA synthesis, the exact nature of this relationship remains unclear. Here we demonstrate that the efficiency of editing is sensitive not only to the concentration of the nucleotide that is inserted, but also to the concentration of the nucleotide templated just downstream of an editing site. These data strongly support a co-transcriptional mechanism of Physarum: RNA editing in which non-encoded nucleotides are added to the 3' end of nascent RNAs. These results also suggest that transcription elongation and nucleotide insertion are competing processes and that recognition of editing sites most likely involves transient pausing by the Physarum: mitochondrial RNA polymerase. In addition, the pattern of nucleotide concentration effects, the context of editing sites and the accuracy of the mitochondrial RNA polymerase argue that the mechanism of Physarum: editing is distinct from that of other co-transcriptional editing systems.
- Published
- 2001
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143. Cinnamophilin as a novel antiperoxidative cytoprotectant and free radical scavenger.
- Author
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Hsiao G, Teng CM, Sheu JR, Cheng YW, Lam KK, Lee YM, Wu TS, and Yen MH
- Subjects
- Animals, Aorta drug effects, Aorta metabolism, Brain drug effects, Brain metabolism, Cell Line, Cell Membrane drug effects, Cell Membrane metabolism, Humans, In Vitro Techniques, Liver drug effects, Liver metabolism, Mitochondria, Liver drug effects, Mitochondria, Liver metabolism, NADPH Oxidases metabolism, NADPH-Ferrihemoprotein Reductase metabolism, Neutrophils drug effects, Neutrophils metabolism, Peroxides metabolism, Rats, Rats, Inbred SHR, Rats, Wistar, Superoxides metabolism, Cryoprotective Agents pharmacology, Free Radical Scavengers pharmacology, Guaiacol analogs & derivatives, Guaiacol pharmacology, Lignans pharmacology, Lipid Peroxidation drug effects
- Abstract
The antioxidant properties of cinnamophilin were evaluated by studying its ability to react with relevant reactive oxygen species, and its protective effect on cultured cells and biomacromolecules under oxidative stress. Cinnamophilin concentration-dependently suppressed non-enzymatic iron-induced lipid peroxidation in rat brain homogenates with an IC50 value of 8.0+/-0.7 microM and iron ion/ADP/ascorbate-initiated rat liver mitochondrial lipid peroxidation with an IC50 value of 17.7+/-0.2 microM. It also exerted an inhibitory activity on NADPH-dependent microsomal lipid peroxidation with an IC50 value of 3.4+/-0.1 microM without affecting microsomal electron transport of NADPH-cytochrome P-450 reductase. Both 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azo-bis(2-amidinopropane) dihydrochloride-derived peroxyl radical tests demonstrated that cinnamophilin possessed marked free radical scavenging capacity. Cinnamophilin significantly protected cultured rat aortic smooth muscle cells (A7r5) against alloxan/iron ion/H2O2-induced damage resulting in cytoplasmic membranous disturbance and mitochondrial potential decay. By the way, cinnamophilin inhibited copper-catalyzed oxidation of human low-density lipoprotein, as measured by fluorescence intensity and thiobarbituric acid-reactive substance formation in a concentration-dependent manner. On the other hand, it was reactive toward superoxide anions generated by the xanthine/xanthine oxidase system and the aortic segment from aged spontaneously hypertensive rat. Furthermore, cinnamophilin exerted a divergent effect on the respiratory burst of human neutrophil by different stimulators. Our results show that cinnamophilin acts as a novel antioxidant and cytoprotectant against oxidative damage.
- Published
- 2001
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144. Gender difference in DNA adduct levels among nonsmoking lung cancer patients.
- Author
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Cheng YW, Hsieh LL, Lin PP, Chen CP, Chen CY, Lin TS, Su JM, and Lee H
- Subjects
- 7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide metabolism, Animals, Cytochrome P-450 CYP1A1 genetics, Enzyme-Linked Immunosorbent Assay, Female, Glutathione Transferase genetics, Humans, Male, Polymorphism, Genetic, Rabbits, Sex Factors, DNA Adducts, Lung Neoplasms epidemiology, Lung Neoplasms genetics, Smoking
- Abstract
Lung cancer is the leading cause of cancer mortality in Taiwanese women. Cigarette smoking cannot explain the high lung cancer mortality in this population because less than 10% of women in Taiwan are smokers. Therefore, environmental factors other than smoking may play an important role in lung cancer development in female nonsmokers. The purpose of this study was to elucidate the role of environmental carcinogen exposure in lung cancer development in Taiwanese female nonsmokers, based on DNA adduct formation. We collected nontumorous lung tissues resected from 62 nonsmoking lung cancer patients and 20 noncancer controls to investigate whether differences in susceptibility to DNA adduct formation exist between men and women. (32)P-postlabeling and ELISA (enzyme-linked immunosorbent assay) with polyclonal antibody against BPDE (7,8-dihydroxy-anti-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene)-DNA adduct were used to evaluate DNA adduct levels in lung tissues of study subjects. Our data showed that the DNA adduct levels of lung cancer patients determined by both assays were significantly higher than those of noncancer controls (P = 0.0001 for (32)P-postlabeling; P = 0.01 for ELISA). Moreover, DNA adduct levels in females were markedly greater than those in males (P = 0.014 for (32)P-postlabeling; P = 0.001 for ELISA). The difference in DNA adduct levels could not be explained by genetic polymorphisms of cytochrome P-4501A1 (CYP1A1) or glutathione S-transferase (GSTM1), as determined by polymerase chain reaction and restriction fragment length polymorphism. These results demonstrate that lung cancer patients have a higher susceptibility to DNA damage than that of noncancer controls. In addition, differences in susceptibility to DNA damage derived from environmental carcinogen exposure were observed between male and female nonsmokers. In conclusion, high susceptibility to DNA damage in females may partially explain the high mortality rate of lung cancer in nonsmoking Taiwanese women., (Copyright 2001 Wiley-Liss, Inc.)
- Published
- 2001
- Full Text
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145. Mechanisms underlying the induction of vasorelaxation in rat thoracic aorta by sanguinarine.
- Author
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Hu CM, Cheng HW, Cheng YW, and Kan JJ
- Subjects
- Animals, Aorta, Thoracic metabolism, Benzophenanthridines, Calcium metabolism, Calcium Channels drug effects, Dithiothreitol pharmacology, Dose-Response Relationship, Drug, Inositol Phosphates biosynthesis, Isoquinolines, Male, Muscle, Smooth, Vascular metabolism, Phenylephrine pharmacology, Rats, Rats, Wistar, Vasoconstriction drug effects, Vasoconstriction physiology, Vasoconstrictor Agents pharmacology, Vasodilation physiology, Alkaloids pharmacology, Aorta, Thoracic drug effects, Cardiotonic Agents pharmacology, Muscle, Smooth, Vascular drug effects, Vasodilation drug effects
- Abstract
In the present study, the effect of sanguinarine (SANG) on smooth muscle was investigated in thoracic aorta isolated from rats. SANG dose-dependently relaxed the phenylephrine (PE, 3 microM)-precontracted aorta; and the concentrations to produce 50% relaxation were 3.18 +/- 0.37 and 3.42 +/- 1.14 microM, respectively, in intact and denuded aorta. These results suggest that the relaxing effect of SANG was endothelium-independent. The total contraction induced by PE was inhibited in aorta pretreated with SANG at microM concentration. Both phasic and tonic contractions induced by PE were inhibited by SANG independently, which were further supported by the fact that inositol 1,4,5-trisphosphate (IP3) formation and 45Ca2+ influx induced by 3 microM PE in denuded aorta were inhibited by SANG concentration-dependently. In addition, the vasocontraction induced by high-K+ was also inhibited by SANG, however, at higher concentrations. The inhibitory effects of SANG were reversed by dithiothreitol, a thiol reducing agent, implying that the oxidation of critical sulfhydryl groups on key molecules that regulate the smooth muscle contraction were involved. These data suggested that the inhibitory effects of SANG on PE-induced vasocontraction might involve the inhibition of IP3 formation and blockade of calcium channel.
- Published
- 2001
- Full Text
- View/download PDF
146. Detection of p53 mutations in sputum smears precedes diagnosis of non-small cell lung carcinoma.
- Author
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Chen JT, Ho WL, Cheng YW, and Lee H
- Subjects
- Aged, Carcinoma, Non-Small-Cell Lung diagnosis, Humans, Lung Neoplasms diagnosis, Male, Middle Aged, Polymerase Chain Reaction, RNA analysis, Carcinoma, Non-Small-Cell Lung genetics, Genes, p53, Lung Neoplasms genetics, Mutation, Sputum chemistry
- Abstract
Little progress has been made in reducing lung cancer mortality by applying conventional methods to early diagnosis and screening. Recent advances in molecular oncology, however, have provided tools which may be of use in this area. p53 gene mutation is the most common gene alteration in the development of lung cancer. Conventional cytologic analysis of sputum is an insensitive test for the diagnosis of lung cancer. In this study, we attempted to establish a polymerase chain reaction (PCR)-based assay for assessing the possibility of early detection of p53 mutation in archival Papanicolaou-stained cytologic sputum smears. Ten sputum smear slides were collected prior to clinical diagnosis from 10 lung cancer patients who had been confirmed to have p53 mutations in surgically resected lung tumors. We successfully obtained sufficient amounts of RNA from each sputum smear specimen for amplification of PCR and direct sequencing. Only one patient was found to have p53 mutation at codon 286; the other nine patients had wild type p53 genes. This result supports the possibility that detection of p53 mutations in cytologic sputum smears is an available strategy for the early diagnosis of lung cancer.
- Published
- 2000
147. Effects of cartap on isolated mouse phrenic nerve diaphragm and its related mechanism.
- Author
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Liao JW, Kang JJ, Liu SH, Jeng CR, Cheng YW, Hu CM, Tsai SF, Wang SC, and Pang VF
- Subjects
- Animals, Bungarotoxins pharmacology, Calcium metabolism, Calcium pharmacology, Calcium-Transporting ATPases metabolism, Diaphragm innervation, Electric Stimulation, Male, Marine Toxins pharmacology, Mice, Mice, Inbred ICR, Muscle Contraction drug effects, Muscle Contraction physiology, Neuromuscular Blockade, Neuromuscular Junction drug effects, Neuromuscular Junction physiology, Nifedipine pharmacology, Phrenic Nerve physiology, Ryanodine metabolism, Sarcoplasmic Reticulum drug effects, Sarcoplasmic Reticulum enzymology, Tetrodotoxin pharmacology, Verapamil pharmacology, Insecticides pharmacology, Phrenic Nerve drug effects, Thiocarbamates pharmacology
- Abstract
Cartap, a nereistoxin analogue pesticide, is reported to have no irritation to eyes in rabbits. However, we have demonstrated recently that cartap could actually cause acute death in rabbits via ocular exposure. Our preliminary study with isolated mouse phrenic nerve diaphragms has shown that instead of neuromuscular blockade, cartap caused muscular contracture. The objective of the study was to examine the effect of cartap on the neuromuscular junction in more detail and to investigate its possible underlying mechanism with isolated mouse phrenic nerve diaphragms and sarcoplasmic reticulum (SR) vesicles. Cartap or nereistoxin at various concentrations was added in the organ bath with isolated mouse phrenic nerve diaphragm and both nerve- and muscle-evoked twitches were recorded. Instead of blocking the neuromuscular transmission as nereistoxin did, cartap caused contracture in stimulated or quiescent isolated mouse phrenic nerve diaphragm. Both the cartap-induced muscular contracture force and the time interval to initiate the contracture were dose-dependent. The contracture induced by cartap was not affected by the pretreatment of the diaphragm with the acetylcholine receptor blocker alpha-bungarotoxin; the Na(+) channel blocker tetrodotoxin; or various Ca(2+) channel blockers, NiCl(2), verapamil, and nifedipine. On the contrary, the contracture was significantly inhibited when the diaphragm was pretreated with ryanodine or EGTA containing Ca(2+)-free Krebs solution or in combination. This suggested that both internal and extracellular Ca(2+) might participate in cartap-induced skeletal muscle contracture. Moreover, cartap inhibited the [(3)H]-ryanodine binding to the Ca(2+) release channel of SR in a dose-dependent manner. Additionally, cartap could induce a significant reduction in Ca(2+)-ATPase activity of SR vesicles at a relatively high dose. The results suggested that cartap might cause the influx of extracellular Ca(2+) and the release of internal Ca(2+), with subsequent induction of muscular contracture in the isolated mouse phrenic nerve diaphragm. Based on these findings, we propose that the acute death of rabbits following ocular exposure to cartap might have resulted from respiratory failure secondary to diaphragm contracture.
- Published
- 2000
- Full Text
- View/download PDF
148. MDM2 mRNA expression is a favorable prognostic factor in non-small-cell lung cancer.
- Author
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Ko JL, Cheng YW, Chang SL, Su JM, Chen CY, and Lee H
- Subjects
- Adenocarcinoma diagnosis, Adenocarcinoma metabolism, Adenocarcinoma mortality, Aged, Carcinoma, Non-Small-Cell Lung mortality, Carcinoma, Squamous Cell diagnosis, Carcinoma, Squamous Cell metabolism, Carcinoma, Squamous Cell mortality, Disease-Free Survival, Exons, Female, Gene Deletion, Genes, p53 genetics, Humans, Immunohistochemistry, Lung Neoplasms mortality, Male, Middle Aged, Prognosis, Proto-Oncogene Proteins c-mdm2, Reverse Transcriptase Polymerase Chain Reaction, Sequence Analysis, DNA, Time Factors, Tumor Suppressor Protein p53 biosynthesis, Carcinoma, Non-Small-Cell Lung diagnosis, Carcinoma, Non-Small-Cell Lung metabolism, Lung Neoplasms diagnosis, Lung Neoplasms metabolism, Nuclear Proteins, Proto-Oncogene Proteins genetics, Proto-Oncogene Proteins metabolism, RNA, Messenger metabolism
- Abstract
MDM2 is one of the downstream target genes for transcriptional activation by the product of the p53 tumor-suppressor gene. Transactivation of MDM2 gene expression is represented by the presence of a functional p53 protein. We hypothesized that MDM2 mRNA expression may be a more suitable prognostic factor than p53 or MDM2 protein expression and p53 gene mutations. In this study, expression of MDM2 mRNA, p53 protein, and MDM2 protein and mutations of the p53 gene were assessed in 81 lung tumor tissue specimens using RT-PCR, immunohistochemistry, and direct sequencing among exons 5-8, respectively. By immunohistochemistry, 33 and 42 of 81 patients with p53 (40.7%) and MDM2 (51.5%) protein expression were found in lung tumor specimens, respectively. The p53 direct sequencing data indicated that 13 of 81 patients (16.0%) had p53 mutations. However, Kaplan-Meier analysis showed that p53 protein and MDM2 protein expression and p53 mutation were not useful as prognostic factors. Interestingly, the survival of patients with MDM2 mRNA expression was longer than that of patients without MDM2 mRNA expression, though MDM2 mRNA expression was not associated with clinicopathological parameters, including tumor grade, tumor stage, tumor type, and TNM values. Moreover, Cox regression analysis showed that MDM2 mRNA expression was a significantly independent favorable prognostic factor in non-small-cell lung cancer (NSCLC) patients. Thus, measuring MDM2 mRNA expression using RT-PCR may be a simple, useful approach for predicting the survival of NSCLC patients., (Copyright 2000 Wiley-Liss, Inc.)
- Published
- 2000
- Full Text
- View/download PDF
149. Inhibition of agonist-induced vasocontraction and impairment of endothelium-dependent vasorelaxation by extract of motorcycle exhaust particles in vitro.
- Author
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Cheng YW and Kang JJ
- Subjects
- Acetylcholine pharmacology, Animals, Aorta, Thoracic drug effects, Calcium metabolism, Contractile Proteins metabolism, Endothelium, Vascular metabolism, In Vitro Techniques, Inositol 1,4,5-Trisphosphate metabolism, Male, Rats, Rats, Wistar, Superoxides metabolism, Endothelium, Vascular drug effects, Motorcycles, Vasoconstriction drug effects, Vasodilation drug effects, Vehicle Emissions toxicity
- Abstract
The in vitro effects of motorcycle exhaust particulate extract (MEPE) on blood vessels were studied in thoracic aorta isolated from Wistar rat. The MEPE relaxed the phenylephrine-precontracted aorta with an EC50 value of 0.05 +/- 0.004 mg/ml. This relaxing effect of MEPE persisted in endothelium-denuded aorta, suggesting that the relaxation induced by MEPE is endothelium-independent. The phenylephrine-induced vasocontraction and inositol 1,4,5-triphosphate formation were inhibited concentration dependently in aorta pretreated with MEPE. However, the high-K+-induced vasocontraction and the Ca2+ sensitivity of the contractile proteins were not significantly affected by MEPE. In addition to the inhibitory effects on agonist-induced contraction, the vasorelaxing effects both of acetylcholine and of sodium nitroprusside were impaired by MEPE. The inhibitory effects of MEPE on acetylcholine and sodium nitroprusside, but not phenylephrine, were reversed by cotreatment with superoxide dismutase. These results showed that the MEPE, added in vitro, inhibited the phenylephrine-induced, but not depolarization-induced, vasocontraction of aorta. The MEPE also impaired the vasorelaxation induced by acetylcholine in a superoxide anion-dependent manner.
- Published
- 1999
- Full Text
- View/download PDF
150. Emodin-induced muscle contraction of mouse diaphragm and the involvement of Ca2+ influx and Ca2+ release from sarcoplasmic reticulum.
- Author
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Cheng YW and Kang JJ
- Subjects
- Animals, Diaphragm physiology, Female, Ion Transport, Male, Mice, Mice, Inbred ICR, Ryanodine metabolism, Sarcoplasmic Reticulum metabolism, Calcium metabolism, Diaphragm drug effects, Emodin pharmacology, Muscle Contraction drug effects, Sarcoplasmic Reticulum drug effects
- Abstract
1. The effects on skeletal muscle of emodin, an anthraquinone, were studied in the mouse isolated diaphragm and sarcoplasmic reticulum (SR) membrane vesicles. 2. Emodin dose-dependently caused muscle contracture, simultaneously depressing twitch amplitude. Neither tubocurarine nor tetrodotoxin blocked the contraction suggesting that it was caused myogenically. 3. The contraction induced by emodin persisted in a Ca2+ free medium with a slight reduction in the maximal force of contraction. The contraction induced by emodin in the Ca2+ free medium was completely blocked when the internal Ca2+ pool of the muscle was depleted by ryanodine. These data suggest that the contraction caused by emodin is due to the release of Ca2+ from the intracellular ryanodine-sensitive pool. 4. In contrast to the effect seen in the Ca2+ free medium, emodin induced a small but consisted contraction in the ryanodine-treated muscle in Krebs medium. The contraction was blocked in the presence of dithiothreitol and was partially blocked by nifedipine, suggesting that oxidation of a sulphhydryl group on the external site of dihydropyridine receptor is involved. 5. Emodin dose-dependently increased Ca2+ release from actively loaded SR vesicles and this effect was blocked by ruthenium red, a specific Ca2+ release channel blocker, and the thiol reducing agent, DTT, suggesting that emodin induced Ca2+ release through oxidation of the critical SH of the ryanodine receptor. 6. [3H]-ryanodine binding was dose-dependently potentiated by emodin in a biphasic manner. The degree of potentiation of ryanodine binding by emodin increased dose-dependently at concentrations up to 10 microM but decreased at higher concentrations of 10-100 microM. 7. These data suggest that muscle contraction induced by emodin is due to Ca2+ release from the SR of skeletal muscle, as a result of oxidation of the ryanodine receptor and influx of extracellular Ca2+ through voltage-dependent Ca2+ channels of the plasma membrane.
- Published
- 1998
- Full Text
- View/download PDF
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