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Shu JC, Soo PC, Chen JC, Hsu SH, Chen LC, Chen CY, Liang SH, Buu LM, Chen CC. Differential regulation and activity against oxidative stress of Dps proteins in Bacillus cereus. Int J Med Microbiol 2013; 303:662-73. [DOI: 10.1016/j.ijmm.2013.09.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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Hsieh YT, Lin MH, Ho HY, Chen LC, Chen CC, Shu JC. Glucose-6-phosphate dehydrogenase (G6PD)-deficient epithelial cells are less tolerant to infection by Staphylococcus aureus. PLoS One 2013; 8:e79566. [PMID: 24223971 PMCID: PMC3817128 DOI: 10.1371/journal.pone.0079566] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 09/25/2013] [Indexed: 01/12/2023] Open
Abstract
Glucose-6-phosphate dehydrogenase (G6PD) is a key enzyme in the pentose phosphate pathway and provides reducing energy to all cells by maintaining redox balance. The most common clinical manifestations in patients with G6PD deficiency are neonatal jaundice and acute hemolytic anemia. The effects of microbial infection in patients with G6PD deficiency primarily relate to the hemolytic anemia caused by Plasmodium or viral infections and the subsequent medication that is required. We are interested in studying the impact of bacterial infection in G6PD-deficient cells. G6PD knock down A549 lung carcinoma cells, together with the common pathogen Staphylococcus aureus, were employed in our cell infection model. Here, we demonstrate that a lower cell viability was observed among G6PD-deficient cells when compared to scramble controls upon bacterial infection using the MTT assay. A significant increase in the intracellular ROS was detected among S. aureus-infected G6PD-deficient cells by observing dichlorofluorescein (DCF) intensity within cells under a fluorescence microscope and quantifying this signal using flow cytometry. The impairment of ROS removal is predicted to enhance apoptotic activity in G6PD-deficient cells, and this enhanced apoptosis was observed by annexin V/PI staining under a confocal fluorescence microscope and quantified by flow cytometry. A higher expression level of the intrinsic apoptotic initiator caspase-9, as well as the downstream effector caspase-3, was detected by Western blotting analysis of G6PD-deficient cells following bacterial infection. In conclusion, we propose that bacterial infection, perhaps the secreted S. aureus α-hemolysin in this case, promotes the accumulation of intracellular ROS in G6PD-deficient cells. This would trigger a stronger apoptotic activity through the intrinsic pathway thereby reducing cell viability when compared to wild type cells.
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Angulo-Barroso RM, Tiernan C, Chen LC, Valentin-Gudiol M, Ulrich D. Treadmill training in moderate risk preterm infants promotes stepping quality--results of a small randomised controlled trial. RESEARCH IN DEVELOPMENTAL DISABILITIES 2013; 34:3629-3638. [PMID: 24012586 DOI: 10.1016/j.ridd.2013.07.037] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 07/24/2013] [Accepted: 07/30/2013] [Indexed: 06/02/2023]
Abstract
Infants at risk for neuromotor delay (NMD) are associated with premature birth and low birth weight. These infants frequently exhibit tone, posture, and movement abnormalities. Therefore, it is important to identify potential interventions to facilitate early motor development within this population. The purpose of this study was to examine the potential benefits of treadmill (TM) training in infants at risk for NMD. Furthermore, relationships between TM stepping performance and onset of walking have been suggested, and therefore, were also explored. Twenty-eight infants at moderate risk for NMD were randomly assigned to one of two groups: (1) TM training (experimental) (N=15) or (2) control (N=13). Infants in the experimental group were trained for 8 min/day, five days/week from study entry until walking onset. Monthly, 5 min of TM stepping performance were videotaped and analysed for infants in both groups to obtain frequency and quality of TM stepping. Groups were different in terms of TM stepping performance with experimental group displaying better stepping. However, they did not differ in age of walking onset (experimental=15.1 months, control=14.6 months). In both groups, frequency of TM stepping was significantly related to onset of walking. Findings suggest that TM training as implemented impact the quality of TM stepping, but did not significantly improve walking onset. Given the significant relationship between stepping and walking onset, the moderate affection of the population, the relative low intensity and lack of individualisation of the training, we suggest future research should further explore the impact of TM training on gait-related variables and include individualised, more intense, and prolonged training.
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Chen RS, Wang WC, Lu ML, Chen YF, Lin HC, Chen KH, Chen LC. Anomalous quantum efficiency for photoconduction and its power dependence in metal oxide semiconductor nanowires. NANOSCALE 2013; 5:6867-73. [PMID: 23779084 DOI: 10.1039/c3nr01635h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The quantum efficiency and carrier lifetime that decide the photoconduction (PC) efficiencies in the metal oxide semiconductor nanowires (NWs) have been investigated. The experimental result surprisingly shows that the SnO2, TiO2, WO3, and ZnO NWs reveal extraordinary quantum efficiencies in common, which are over one to three orders of magnitude lower than the theoretical expectation. The surface depletion region (SDR)-controlled photoconductivity is proposed to explain the anomalous quantum efficiency and its power dependence. The inherent difference between the metal oxide nanostructures such as carrier lifetime, carrier concentration, and dielectric constant leading to the distinct PC performance and behavior are also discussed.
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Walker GA, Xenophontos M, Chen LC, Cheung KL. Long-term efficacy and safety of exemestane in the treatment of breast cancer. Patient Prefer Adherence 2013; 7:245-58. [PMID: 23569364 PMCID: PMC3616141 DOI: 10.2147/ppa.s42223] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Exemestane, a steroidal aromatase inhibitor, is licensed for postmenopausal patients with estrogen receptor (ER)-positive breast cancer as second-line therapy in metastatic disease following antiestrogen failure and as part of sequential adjuvant therapy following initial tamoxifen. This study is a systematic literature review, evaluating exemestane in different clinical settings. The Ovid Medline (1948-2012), Embase (1980-2012), and Web of Science (1899-2012) databases were searched. Forty-two relevant articles covering randomized controlled trials were reviewed for efficacy and safety, and three for adherence. With regard to efficacy in metastatic disease, exemestane is superior to megestrol acetate after progression on tamoxifen. There is evidence for noninferiority to fulvestrant (following a prior aromatase inhibitor) and to nonsteroidal aromatase inhibitors in the first-line setting. Combined use with everolimus is shown to be more efficacious than exemestane alone following previous aromatase inhibitor use. In the adjuvant setting, a switch to exemestane after 2-3 years of tamoxifen is superior to 5 years of tamoxifen. Exemestane is noninferior to 5 years of tamoxifen as upfront therapy, and may have a role as an extended adjuvant therapy. Used as neoadjuvant therapy, increased breast conservation is achievable. As chemoprevention, exemestane significantly reduces the incidence of breast cancer in "at-risk" postmenopausal women. Exemestane is associated with myalgias and arthralgias, as well as reduced bone mineral density and increased risk of fracture, which do not appear to persist at follow-up, with subsequent return to pretreatment values. Compared with tamoxifen, there is a reduced incidence of endometrial changes, thromboembolic events, and hot flashes. Limited evidence shows nonadherence in 23%-32% of patients. Evidence is growing in support of exemestane in all clinical settings. It is generally more efficacious and has a better safety profile than tamoxifen. How it compares with the nonsteroidal aromatase inhibitors remains to be established. Further studies are required on adherence to ensure that maximum benefit is obtained.
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Chen LC, Ahmed S, Gesche M, Henry Mosley W. Prospective study of birth interval dynamics in rural Bangladesh. Population Studies 2012; 28:277-97. [PMID: 22070207 DOI: 10.1080/00324728.1974.10405180] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
Abstract A group of 209 married, fecund women in rural Bangladesh were studied prospectively for 24 months from 1969 to 1971 to define some of the biological and sociological factors relating to fertility performance. These women were selected from a larger study population of 112,000 that had been followed with a daily house-to-house vital registration programme since 1966. The selected women were interviewed bi-weekly and were asked questions about menstruation, pregnancy, lactation, husband's occupational absences, and monthly urine tests for pregnancy were taken. The results for 193 non-contracepting women revealed that the seasonal pattern of births previously observed in this population could be associated with a corresponding seasonal pattern of conceptions and that this was due to a seasonal trend in fecundability. The highest conception rates were in the coolest months of the year. Post-partum lactational amenorrhoea was very prolonged, averaging 17 months for women with a surviving child. The appearance of the first post-partum menstrual flow (onset of ovulation) also had a seasonal trend which could not be adequately explained. The median waiting time to conception, once menstruation had resumed was eight months. This interval was influenced by seasonal fluctuations, as well as by the age of women and by husbands' absences. The foetal wastage rate was 15·0 per 100 conceptions, with 62 per cent of the foetal losses occurring during the second month of gestation. Overall, the average birth interval was 33 months, with the prolonged lactational amenorrhoea accounting for almost 45 per cent of this interval. From the Department of Population Dynamics, Johns Hopkins University, School of Hygiene and Public Health, Baltimore, Maryland 21205.
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Markman B, Tabernero J, Krop I, Shapiro GI, Siu L, Chen LC, Mita M, Melendez Cuero M, Stutvoet S, Birle D, Anak Ö, Hackl W, Baselga J. Phase I safety, pharmacokinetic, and pharmacodynamic study of the oral phosphatidylinositol-3-kinase and mTOR inhibitor BGT226 in patients with advanced solid tumors. Ann Oncol 2012; 23:2399-2408. [PMID: 22357447 DOI: 10.1093/annonc/mds011] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND This phase I dose-escalation study investigated the maximum tolerated dose (MTD), safety, pharmacokinetics, pharmacodynamics (PDs), and preliminary antitumor activity of BGT226, a potent, oral dual phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin inhibitor. PATIENTS AND METHODS Fifty-seven patients with advanced solid tumors received BGT226 2.5-125 mg/day three times weekly (TIW). Dose escalation was guided by an adaptive Bayesian logistic regression model with overdose control. Assessments included response per RECIST, [18F]-fluorodeoxyglucose uptake, and phosphorylated-S6 in skin and paired tumor samples. RESULTS Three patients (125 mg cohort) had dose-limiting toxic effects (grade 3 nausea/vomiting, diarrhea). BGT226-related adverse events included nausea (68%), diarrhea (61%), vomiting (49%), and fatigue (19%). BGT226 demonstrated rapid absorption, variable systemic exposure, and a median half-life of 6-9 h. Seventeen patients (30%) had stable disease (SD) as best response. Nine patients had SD for ≥16 weeks. Thirty patients (53%) achieved stable metabolic disease as assessed by [18F]-fluorodeoxyglucose-positron emission tomography; however, no correlation between metabolic response and tumor shrinkage according to computed tomography was observed. PD changes suggested PI3K pathway inhibition but were inconsistent. CONCLUSIONS The MTD of BGT226 was 125 mg/day TIW, and the clinically recommended dose was 100 mg/day TIW. Limited preliminary antitumor activity and inconsistent target inhibition were observed, potentially due to low systemic exposure.
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Wu YL, Chen LC, Sheu MH, Chen TH, Wu SC, Wu CL, Li SY, Yang WC, Ng YY. Peritoneal-uterine communication: a complication of prolonged embedding of a peritoneal catheter. ARCH ESP UROL 2012; 32:481-3. [PMID: 22859846 DOI: 10.3747/pdi.2011.00016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Chang SC, Hsuan SL, Lin CC, Lee WC, Chien MS, Chen LC, Wu JH, Cheng SJ, Chen CL, Liao JW. Probable Blastomyces dermatitidis infection in a young rat. Vet Pathol 2012; 50:343-6. [PMID: 22711744 DOI: 10.1177/0300985812451624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
A 21-week-old male untreated control SHR/NCrlNarl rat was found dead during an experiment. Grossly, pulmonary lesions were characterized by multifocal to coalescing firm gray-white nodules randomly scattered on the surface. Microscopically, bronchopneumonia was found with pyogranulomas containing neutrophils, macrophages, and numerous thick-walled yeast cells. Yeast cells, 5 to 25 μm in diameter, with no branching of hyphae were observed by staining with hematoxylin and eosin, Diff-Quik, and periodic acid-Schiff. Furthermore, polymerase chain reaction (PCR) using panfungal and nested PCR primers were used for detection of Blastomyces dermatitidis DNA in the lung tissue. After sequencing and matching with DNA sequences in the GenBank, the sample showed a similarity of 94.6% and 97% to Ajellomyces dermatitidis (B. dermatitidis), respectively. On the basis of these results, probable pulmonary blastomycosis was diagnosed. The origin of the infection in the colony rat is undetermined.
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Chen LC, Chen JC, Shu JC, Chen CY, Chen SC, Chen SH, Lin CY, Lu CY, Chen CC. Interplay of RsbM and RsbK controls the σ(B) activity of Bacillus cereus. Environ Microbiol 2012; 14:2788-99. [PMID: 22640257 DOI: 10.1111/j.1462-2920.2012.02788.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The alternative transcription factor σ(B) of Bacillus cereus controls the expression of a number of genes that respond to environmental stress. Four proteins encoded in the sigB gene cluster, including RsbV, RsbW, RsbY (RsbU) and RsbK, are known to be essential in the σ(B)-mediated stress response. In the context of stress, the hybrid sensor kinase RsbK is thought to phosphorylate the response regulator RsbY, a PP2C serine phosphatase, leading to the dephosphorylation of the phosphorylated RsbV. The unphosphorylated RsbV then sequesters the σ(B) antagonist, RsbW, ultimately liberating σ(B). The gene arrangement reveals an open reading frame, bc1007, flanked immediately downstream by rsbK within the sigB gene cluster. However, little is known about the function of bc1007. In this study, the deletion of bc1007 resulted in high constitutive σ(B) expression independent of environmental stimuli, indicating that bc1007 plays a role in σ(B) regulation. A bacterial two-hybrid analysis demonstrated that BC1007 interacts directly with RsbK, and autoradiographic studies revealed a specific C(14)-methyl transfer from the radiolabelled S-adenosylmethionine to RsbK when RsbK was incubated with purified BC1007. Our data suggest that BC1007 (RsbM) negatively regulates σ(B) activity by methylating RsbK. Additionally, mutagenic substitution was employed to modify 12 predicted methylation residues in RsbK. Certain RsbK mutants were able to rescue σ(B) activation in a rsbK-deleted bacterial strain, but RsbK(E439A) failed to activate σ(B), and RsbK(E446A) only moderately induced σ(B). These results suggest that Glu439 is the preferred methylation site and that Glu446 is potentially a minor methylation site. Gene arrays of the rsbK orthologues and the neighbouring rsbM orthologues are found in a wide range of bacteria. The regulation of sigma factors through metylation of RsbK-like sensor kinases appears to be widespread in the microbial world.
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Chen CC, Cheng YY, Chen SC, Tuan YF, Chen YJ, Chen CY, Chen LC. Cyclooxygenase-2 expression is up-regulated by 2-aminobiphenyl in a ROS and MAPK-dependent signaling pathway in a bladder cancer cell line. Chem Res Toxicol 2012; 25:695-705. [PMID: 22288910 DOI: 10.1021/tx2004689] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Overexposure to biphenyl amine compounds, which are found in smoke and azo-dyes, is linked to the occurrence of bladder cancer. However, the molecular mechanisms of biphenyl amine compound-induced bladder cancer are still unclear. Many studies have demonstrated that overexpression of cyclooxygenase-2 (COX-2) in neoplastic lesions is associated with carcinogenesis. In this study, we have demonstrated that 2-aminobiphenyl (2-ABP) up-regulated the expression of COX-2 in a dose- and time-dependent manner in TSGH-8301 bladder cancer cells. This 2-ABP-induced COX-2 expression was attenuated by ROS scavenger NAC and NADPH oxidase inhibitors apocynin and DPI. The p22phox subunit of NADPH oxidase, but not p67, and Nox2 was up-regulated by 2-ABP. Knocking down p22phox by siRNA significantly reduced 2-ABP-induced COX-2 expression. Furthermore, 2-ABP also activated the ERK/JNK-AP1 pathways, and this effect was also abolished by NADPH oxidase inhibitors. Blocking the ERK/JNK-AP1 signaling pathways by pharmacological inhibitors attenuated 2-ABP-induced COX-2 expression. Overexpression of the upstream ERK activator MEK1 significantly and consistently increased 2-ABP-mediated COX-2 expression. Transfection of a dominant negative c-Jun mutant, TAM-67, blocked 2-ABP-mediated COX-2 expression, demonstrating that c-Jun was responsible for the transcriptional activation. Taken together, these results demonstrate that 2-ABP induces the carcinogenic factor COX-2 and that this induction is mediated through NADPH oxidase-derived ROS-dependent JNK/ERK-AP-1 pathways.
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Chen RS, Yang TH, Chen HY, Chen LC, Chen KH, Yang YJ, Su CH, Lin CR. Photoconduction mechanism of oxygen sensitization in InN nanowires. NANOTECHNOLOGY 2011; 22:425702. [PMID: 21934198 DOI: 10.1088/0957-4484/22/42/425702] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The photoconduction (PC) mechanism in indium nitride (InN) nanowires (NWs) has been investigated via environment-, temperature-, and power-dependent measurements. The adsorbed oxygen-induced modulation of the surface state is proposed to be the leading factor in the long lifetime or high gain transport and in sensitizing photocurrent generation in the InN NWs. The electron trapping effect by adsorbed oxygen can be verified by the increased activation energy from 33 ± 4 (in vacuum) to 58 ± 2 meV (in oxygen). The observed supralinear power dependence of photocurrent also suggests the presence of acceptor states that influence the carrier recombination behavior and compensate the thermal carriers in the InN NWs. The potential influence of native oxide on the molecule-sensitive PC in this nitride nanomaterial is also inferred.
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Ching Chen S, Hseu YC, Sung JC, Chen CH, Chen LC, Chung KT. Induction of DNA damage signaling genes in benzidine-treated HepG2 cells. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2011; 52:664-72. [PMID: 21818781 DOI: 10.1002/em.20669] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 06/20/2011] [Accepted: 06/21/2011] [Indexed: 05/10/2023]
Abstract
We examined genotoxicity and DNA damage response in HepG2 cells following exposure to benzidine. Using the Comet assay, we showed that benzidine (50-200 μM) induces DNA damage in HepG2 cells. DNA damage signaling pathway-based PCR arrays were used to investigate expression changes in genes involved in cell-cycle arrest, apoptosis, and DNA repair and showed upregulation of 23 genes and downregulation of one gene in benzidine-treated cells. Induction of G2/M arrest and apoptosis was confirmed at the protein level. Real-time PCR and Western blots were used to demonstrate the expression of select DNA repair-associated genes from the PCR array. Upregulation of the p53 protein in benzidine-treated cells suggests the induction of the p53 DNA damage signaling pathway. Collectively, DNA damage response genes induced by benzidine indicate recruitment complex molecular machinery involved in DNA repair, cell-cycle arrest, and potentially, activation of the apoptosis.
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Wu JC, Hseu YC, Tsai JS, Chen LC, Chye SM, Chen CH, Ching Chen S. Fenthion and terbufos induce DNA damage, the expression of tumor-related genes, and apoptosis in HEPG2 cells. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2011; 52:529-37. [PMID: 21538558 DOI: 10.1002/em.20652] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Accepted: 02/08/2011] [Indexed: 05/04/2023]
Abstract
This study investigates the effects of fenthion and terbufos, two organophosphorous pesticides, on DNA damage, tumor-related gene expression, and apoptosis in HepG2 cells. We found that exposure to concentrations ranging from 50 to 200 μM of fenthion and terbufos for 2 hr caused significant death in HepG2 cells. Both compounds induced DNA damage in a concentration-dependent manner as measured using the alkaline comet assay. Tumor-related genes (jun, myc, and fos) and apoptosis-related genes (socs3, tnfaip3, ppp1r15a, and nr4a1) were up-regulated by both compounds. Finally, both compounds induced apoptosis. The results demonstrate that both terbufos and fenthion induce DNA damage and should be considered potentially hazardous to humans.
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Yang JI, Chen LC, Shih YY, Hsieh C, Chen CY, Chen WM, Chen CC. Cloning and characterization of β-agarase AgaYT from Flammeovirga yaeyamensis strain YT. J Biosci Bioeng 2011; 112:225-32. [PMID: 21715227 DOI: 10.1016/j.jbiosc.2011.05.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 05/29/2011] [Accepted: 05/31/2011] [Indexed: 11/29/2022]
Abstract
A bacterium with potent agar-degrading capability was isolated from the surface of a red algae, Gracilaria tenuistipitata. Based on phenotypic characteristics, 16S rDNA gene sequence and a phylogenetic analysis, this bacterium was identified and named as Flammeovirga yaeyamensis strain YT. PCR using homology-based degenerate primers was employed to clone any agarase gene belonging to GH16 family encoded in F. yaeyamensis strain YT. The resolved 1512 nucleotides revealed that the cloned gene, namely AgaYT, encodes a protein of 503 amino acids comprising a signal peptide, a glycosyl hydrolase catalytic module and a C-terminal domain with an unknown function. The recombinant protein r-AgaYT is an endo-type β-agarase hydrolyzing agarose to yield neoagarobiose and neoagarotetraose as the main hydrolytic products. The specific activity of r-AgaYT was determined about 178.6 U mg(-1) at 40°C and pH 8.0.
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Huang JL, Yeh KW, Yao TC, Huang YL, Chung HT, Ou LS, Lee WI, Chen LC. Pediatric lupus in Asia. Lupus 2011; 19:1414-8. [PMID: 20947550 DOI: 10.1177/0961203310374339] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Of all patients with systemic lupus erythematosus (SLE), 15-20% are diagnosed during childhood, with disease onset prior to the age of 16 years. Because disease expression in SLE is influenced by environment factors and differs between racial and ethnic groups. The aims of this review were to describe prevalence, clinical manifestations, common infectious complications, and outcome of pediatric-onset SLE in Asia. The prevalence of pediatric-onset SLE was 6.3-19.3 per 100,000 in Asia. The ratio of female to male was 4.7-6.2. The mean age at diagnosis of pediatric-onset SLE was 8.6-13.5 years. The most common clinical features of pediatric-onset SLE in Asia were cutaneous rashes, arthritis, hematological involvement and nephritis. The occurrence of nephritis varies from 29% to 81%. The most common histopathology of lupus nephritis was diffuse proliferative glomerulonephritis (WHO Class-IV) which occurred in 39.4-54% of case of lupus nephritis. Pediatric-onset SLE patients with infections have poor outcomes than uninfected patients. Gram-negative bacilli are the most common microorganisms responsible for bacteremia in Asian patients with SLE. Recurrent major infections predict poorer disease outcome and associated organ damage in pediatric-onset SLE. Improving the survival of SLE patients was reported in Asia in recent decades. The survival was 92% at the age of 5 years, 86% at 10 years and 79% at 15 years in children with SLE in Taiwan in 2008.
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Chung YM, Chang FR, Tseng TF, Hwang TL, Chen LC, Wu SF, Lee CL, Lin ZY, Chuang LY, Su JH, Wu YC. A novel alkaloid, aristopyridinone A and anti-inflammatory phenanthrenes isolated from Aristolochia manshuriensis. Bioorg Med Chem Lett 2011; 21:1792-4. [DOI: 10.1016/j.bmcl.2011.01.067] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 12/31/2010] [Accepted: 01/17/2011] [Indexed: 10/18/2022]
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Chow SN, Chen RJ, Chen CH, Chang TC, Chen LC, Lee WJ, Shen J, Chow LP. Analysis of protein profiles in human epithelial ovarian cancer tissues by proteomic technology. EUR J GYNAECOL ONCOL 2010; 31:55-62. [PMID: 20349782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
BACKGROUND Screening in ovarian cancer is progressively finding out candidate genes and proteins which may work as screening biomarkers and play a role in tumor progression. We examined the protein expression patterns of ovarian cancer tissues using two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization-time of fight mass spectrometry (MALDI-TOF MS). METHODS Tissues from 36 ovarian cancers and 20 normal ovaries were examined by 2-DE. The images of silver stained gels were analyzed by ImageMaster 2D Elite. The peptide mixtures, after in-gel digestion, were determined by MALDI-TOF MS for fingerprinting. The de-isotope tryptic peptide profiles were matched by using the Mascot search engine based on the entire NCBI and Swiss-Prot protein databases. Western/dot blots were then applied to verify the findings. RESULTS In ovarian cancer, 12 proteins that showed differential expressions were identified unequivocally. Among these proteins, five proteins (galectin-1, cathepsin B, ubiquitin carboxy-terminal hydrolase L1, HLA class II antigen DRB1-11 and heat shock protein 27) were up-regulated and seven proteins (cellular retinol-binding protein, transthyretin, SH3 binding glutamic-rich-like protein, tubulin-specific chaperone A, DJ-1, gamma-actin and tropomyosin 4) were down-regulated. CONCLUSION The present study is the first to report the up-regulation of ubiquitin carboxy-terminal hydrolase L1 and the down-regulation of SH3 binding glutamic-rich-like protein, tubulin-specific chaperone A, and tropomyosin 4 in human ovarian cancer tissues. Further cloning and functional analysis of these salient proteins will provide more information on their pathophysiologic roles in ovarian cancer.
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Kong CH, Chen LC, Xu XH, Wang P, Wang SL. Allelochemicals and activities in a replanted Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) tree ecosystem. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2008; 56:11734-11739. [PMID: 19053367 DOI: 10.1021/jf802666p] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Autotoxicity is a major reason for replant problems in managed tree ecosystems. Studies have related phenolics-based allelochemicals to autotoxicity. We selected a 20-year-old replanted Chinese fir [Cunninghamia lancealata (Lamb.) Hook] tree ecosystem to isolate, identify, determine the biological activity of, and quantify soil phytotoxins. Eight common phenolics (coumarin, vanillin, isovanillin, and p-hydroxybenzoic, vanillic, benzoic, cinnamic, and ferulic acids), friedelin, and a novel cyclic dipeptide (6-hydroxy-1,3-dimethyl-8-nonadecyl-[1,4]-diazocane-2,5-diketone) were obtained by using the bioassay-guided isolation technique from toxic soil of the replanted Chinese fir tree ecosystem. Chemical structures were determined by spectroscopic means, including 2D-NMR (COSY, HMQC, HMBC, and NOESY) experiments. High concentrations of soil phenolics and friedelin were observed in the natural evergreen broadleaf forest (CK) rather than in the Chinese fir tree ecosystem. The phenolics and friedelin were not phytotoxic to Chinese fir trees. However, the cyclic dipeptide inhibited Chinese fir growth at soil concentrations determined in the replanted Chinese fir tree ecosystem. There was a significantly higher soil concentration of cyclic dipeptide in the replanted Chinese fir tree ecosystem than in a fresh Chinese fir tree ecosystem. The results suggest that phenolics and friedelin are not key allelochemicals since they are weakly phytotoxic and are detected in low concentrations in the replanted Chinese fir tree ecosystem, while cyclic dipeptide is a highly active allelochemical with a phytotoxic effect that limits offspring growth in the replanted Chinese fir tree ecosystem. The discovery of cyclic dipeptide, as well as a further understanding of its potential action mechanism in the replanted Chinese fir tree ecosystem, may contribute to solving the replant problems in managed tree ecosystems.
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Chang HJ, Hsieh YP, Chen TT, Chen YF, Liang CT, Lin TY, Tseng SC, Chen LC. Strong luminescence from strain relaxed InGaN/GaN nanotips for highly efficient light emitters. OPTICS EXPRESS 2007; 15:9357-65. [PMID: 19547278 DOI: 10.1364/oe.15.009357] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Semiconductor heterostructures represent the most important building block for current optoelectronic devices. One of the common features of semiconductor heterostructures is the existence of internal strain due to lattice mismatch. The internal strain can tilt the band alignment and significantly alter the physical properties of semiconductor heterostructures, such as reducing the internal quantum efficiency of a light emitter. Here, we provide a convenient route to release the internal strain by patterning semiconductor heterostructures into nanotip arrays. The fabrication of the nanotip arrays was achieved by self-masked dry etching technique, which is simple, low cost and compatible with current semiconductor technologies. By implementing our approach to InGaN/GaN multiple quantum wells, we demonstrate that the light emission can be enhanced by up to 10 times. Our approach renders an excellent opportunity to manipulate the internal strain, and is very useful to create highly efficient solid state emitters.
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Chen JT, Hsiao CL, Hsu HC, Wu CT, Yeh CL, Wei PC, Chen LC, Chen KH. Epitaxial Growth of InN Films by Molecular-Beam Epitaxy Using Hydrazoic Acid (HN3) as an Efficient Nitrogen Source. J Phys Chem A 2007; 111:6755-9. [PMID: 17500542 DOI: 10.1021/jp068949g] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Epitaxial InN films have been successfully grown on c-plane GaN template by gas-source molecular-beam epitaxy with hydrazoic acid (HN3) as an efficient nitrogen source. Results in residual-gas analyzer show that the HN3 is highly dissociated to produce nitrogen radicals and can be controlled in the amounts of active nitrogen species by tuning HN3 pressure. A flat and high-purity InN epifilm has been realized at the temperature near 550 degrees C, and a growth rate of 200 nm/hr is also achieved. Moreover, the epitaxial relationship of the InN(002) on the GaN(002) is reflected in the X-ray diffraction, and the full-width at half-maximum of the InN(002) peak as narrow as 0.05 degrees is related to a high-quality crystallinity. An infrared photoluminescence (PL) emission peak at 0.705 eV and the integrated intensity increasing linearly with excitation power suggest that the observed PL can be attributed to a free-to-bound recombination.
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Chen LC, Yonehama J, Ueda T, Hori H, Hiraoka K. Visible-laser desorption/ionization on gold nanostructures. JOURNAL OF MASS SPECTROMETRY : JMS 2007; 42:346-53. [PMID: 17199254 DOI: 10.1002/jms.1165] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
In this report, we describe the visible-laser desorption/ionization of biomolecules deposited on gold-coated porous silicon and gold nanorod arrays. The porous silicon made by electrochemical etching was coated with gold using argon ion sputtering. The gold nanorod arrays were fabricated by electrodepositing gold onto a porous alumina template, and the subsequent partial removal of the alumina template. A frequency-doubled/tripled Nd : YAG laser was used to irradiate the gold nanostructured substrate, and the desorbed molecular ions were mass-analyzed by a time-of-flight mass spectrometer. The desorption/ionization of biomolecules for both substrates was favored by the use of the 532-nm visible-laser, which is in the range of the localized surface plasmon resonance of the gold nanostructure. The present technique offers a potential analytical method for low-molecular-weight analytes that are rather difficult to handle in the conventional matrix-assisted laser desorption/ionization (MALDI) mass spectrometry.
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Wang JM, Ko CY, Chen LC, Wang WL, Chang WC. Functional role of NF-IL6beta and its sumoylation and acetylation modifications in promoter activation of cyclooxygenase 2 gene. Nucleic Acids Res 2006; 34:217-31. [PMID: 16397300 PMCID: PMC1325205 DOI: 10.1093/nar/gkj422] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
NF-IL6β regulates gene expression and plays function roles in many tissues. The EGF-regulated cyclooxygenase-2 (cox-2) expression is mediated through p38MAPK signaling pathway and positively correlates with NF-IL6β expression in A431 cells. NF-IL6β coordinated with c-Jun on cox-2 transcriptional activation by reporter and small interfering RNA assays. NF-IL6β could directly bind to CCAAT/enhancer-binding protein (C/EBP) and cyclic AMP-response element (CRE) sites of the cox-2 promoter by in vitro-DNA binding assay. The C/EBP site was important for basal and, to a lesser extent, for EGF-regulated cox-2 transcription, while the CRE site was a more specific response to EGF inducibility of cox-2 gene. SUMO1 expression attenuated EGF- and NF-IL6β-induced cox-2 promoter activities. NF-IL6β was found to be sumoylated by in vivo- and in vitro-sumoylation assays, and the SUMO1-NF-IL6β (suNF-IL6β) lost its ability to interact with p300 in in vitro-binding assay. NF-IL6β was also acetylated by p300, and acetylation of NF-IL6β enhanced the cox-2 promoter activity stimulated by NF-IL6β itself. In vivo-DNA binding assay demonstrated that EGF stimulated the recruitment of p300 and NF-IL6β to the cox-2 promoter, yet promoted the dissociation of SUMO1-modificated proteins from the promoter. These results indicated that NF-IL6β plays a pivotal role in the regulation of basal and EGF-induced cox-2 transcription.
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Chen LC, Wang BR, Chou YC, Tien JH. Drug utilization pattern of Chinese herbal medicines in a general hospital in Taiwan. Pharmacoepidemiol Drug Saf 2005; 14:651-7. [PMID: 15786515 DOI: 10.1002/pds.1087] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
PURPOSE Drug utilization studies are important for the optimization of drug therapy and have received a great attention in recent years. Most of the information on drug use patterns has been derived from studies in modern Western medicines; however, studies regarding the drug utilization of traditional Chinese medicine (CM) are few. The present study was the first clinical research to evaluate the drug utilization patterns of Chinese herbal medicines in a general hospital in Taiwan. METHODS Data were collected prospectively from the patients attending the Traditional Medicine Center of Taipei Veteran General Hospital under CM drug treatments. The study was carried out over a period of 1 year, from January 2002 to December 2002. Core drug use indicators, such as the average number of drugs per prescriptions, the dosing frequency of prescriptions, and the most common prescribed CM herbs and formulae were evaluated. The primary diagnosis and the CM drugs prescribed for were also revealed. All data were analyzed by descriptive statistics. RESULTS A total of 10 737 patients, representing 52 255 CM drugs, were screened during the study period. Regarding the prescriptions, the average number of drugs per prescription was 4.87 and 37.21% of prescriptions were composed by five drugs. Most of prescriptions (91.38%) were prescribed for three times a day. The most often prescribed Chinese herb was Hong-Hwa (5.76%) and the most common Chinese herbal formula was Jia-Wey-Shiau-Yau-San (3.80%). The most frequent main diagnosis was insomnia (15.58%), followed by menopause (5.22%) and constipation (5.09%). CONCLUSION The survey revealed the drug use pattern of CMs in a general hospital. The majority of CM prescriptions were composed by 3-6 drugs and often prescribed for three times a day. Generally, the rational drug uses of CM drugs were provided with respect to the various diagnoses.
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Chen LC, Chen BK, Chang WC. Activating protein 1-mediated cyclooxygenase-2 expression is independent of N-terminal phosphorylation of c-Jun. Mol Pharmacol 2005; 67:2057-69. [PMID: 15772294 DOI: 10.1124/mol.104.010900] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Transcriptional activation of the cyclooxygenase (COX)-2 gene is responsible for high level of prostaglandin production during inflammation and carcinogenesis. We found previously that c-Jun induction plays a crucial role in epidermal growth factor (EGF)-induced gene expression of COX-2. In this study, the functional role of c-Jun in EGF-induced transcriptional activation of COX-2 in A431 cells was investigated. We found that overexpression of c-Jun N-terminal phosphorylation site mutants had similar stimulatory effects on COX-2 promoter activity and protein expression as c-Jun wild type. TAM-67, a mutant of c-Jun that lacks the N-terminal transactivation domain of c-Jun, also enhanced COX-2 promoter activity and protein expression in cells treated with EGF. In vitro DNA affinity precipitation and reporter assays revealed that regulation of c-Jun C terminus by EGF enhanced c-Jun binding to COX-2 promoter and induced COX-2 expression. Furthermore, we demonstrated that c-Fos, which provides transactivation function in Jun/Fos heterodimer, was required for EGF-induced expression of COX-2. These results indicated that c-Jun N-terminal phosphorylation was not required for EGF-induced expression of COX-2. c-Jun, which could recruit other transcription factors such as c-Fos, was required for EGF-induced expression of COX-2 in A431 cells.
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