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Search Results: 1 - 10 of 49780 matches for " Wen-Chung Chang "
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Identification of a constitutional mutation in the WT1 gene in Taiwanese patients with Wilms tumor  [PDF]
Meng-Yao Lu, Wen-Chung Wang, Chiao-Wen Lin, Alice Chang, Yen-Chein Lai
Advances in Bioscience and Biotechnology (ABB) , 2014, DOI: 10.4236/abb.2014.53029
Abstract:

The overall frequency of WT1 gene alterations in Wilms tumor is still unclear in Taiwan. Here we conducted molecular genetic analysis of the WT1 gene in Taiwanese patients with Wilms tumor. Polymerase chain reaction and direct sequencing were performed on DNA samples from blood and paraffin-embedded tumor specimens. A constitutional mutation in the WT1 gene was found in one DNA sample from peripheral blood lymphocytes. The remaining DNA samples from peripheral blood lymphocytes and paraffin-embedded tumor specimens were tested negative for both constitutional mutations and somatic mutations. Thus, mutations at other Wilms tumor loci may play an important role in Wilms tumor development.

Hand-Eye Coordination for Robotic Assembly Tasks
Wen-Chung Chang, Chia-Hung Wu
International Journal of Automation and Smart Technology , 2012, DOI: 10.5875/ausmt.v2i4.162
Abstract: This paper addresses issues related to the design and implementation of robotic assembly tasks. Specifically, we consider automatic assembly systems with real-time visual sensing for the back shells of cellular phones. Typically, industrial assembly tasks are accomplished using either the look-then-move open-loop or the look-and-move closed-loop control approach. For either approach, successful assembly requires that issues concerned with task accuracy must be considered based on camera calibration parameters. For the hand-eye robotic system to operate in real-time, one must adopt an appropriate control structure to maximize task efficiency. Simple and repetitive assembly tasks can be performed quickly through look-then-move open-loop controls. However, relatively slower look-and-move closed-loop control approaches are better suited for complex tasks or those requiring greater flexibility. To accomplish automatic assembly tasks with real-time visual sensing, either eye-to-hand or eye-in-hand vision must be employed. The proposed vision-based control approaches for back shell assembly tasks are likely to have real potential in industrial manufacturing applications.
Computer Tomography and Ultrasonography Image Registration Based on the Cooperation of GPU and CPU  [PDF]
Ying-Chih Lin, Chien-Liang Huang, Chin-Sheng Chen, Wen-Chung Chang, Yu-Jen Chen, Chia-Yuan Liu
Journal of Signal and Information Processing (JSIP) , 2013, DOI: 10.4236/jsip.2013.43B014
Abstract:

Image registration is wildly used in the biomedical image, but there are too many textures and noises in the biomedical image to get a precise image registration. In order to get the excellent registration performance, it needs more complex image processing, and it will spend expensive computation cost. For the real time issue, this paper proposes edge gradient direction image registration applied to Computer Tomography(CT) image and Ultrasonography (US) image based on the cooperation of Graphic Processor Unit (GPU) and Central Processor Unit (CPU). GPU can significantly reduce the computation time. First, the CT image slice is extracted from the CT volume by the region growing and the interpolation algorithm. Secondly, the image pre-processing is employed to reduce the image noises and enhance the image features. There are two kinds of the image pre-processing algorithms invoked in this paper: 1) median filtering and 2) anisotropic diffusion. Last but not least, the image edge gradient information is obtained by Canny operator, and the similarity measurement based on gradient direction is employed to evaluate the similarity between the CT and the US images. The experimental results show that the proposed architecture can distinctively improve the efficiency and are more suitably applied to the real world.

Clonal Dissemination of Genetically Diverse Fluoroquinolone-Resistant Extended-Spectrum Beta-Lactamase (ESBL)-Producing Escherichia coli ST131 in a Veterans Hospital in Southern Taiwan  [PDF]
Wen-Chung Chang, Chung-Jung Wu, Chuan-Shee Liu, Yilin Tsai, Jen-Jain Lee, Yuting Hsiao, Shu-Ling Chou, Chih-Hao Sun, Chishih Chu
Advances in Microbiology (AiM) , 2016, DOI: 10.4236/aim.2016.69059
Abstract: Uropathogenic Escherichia coli is the common pathogen to cause urinary tract infections (UTIs) and have become multidrug-resistant (MDR) extended-spectrum β-lactamase (ESBL) producers. The differences in the antimicrobial susceptibility, 5 bla genes, 12 virulence genes of 87 clinical ESBL-producing E. coli isolates and genomic variations and sequence types of 18 recurrent and repeated isolates from 9 patients were investigated. The 87 MDR-ESBL isolates collected mainly from indwelling urinary catheters (IUCs) and UTIs were highly resistant to fluoroquinolones, with over 50% of the isolates being resistant to cefepime and piperacillin/tazobactam and a few being resistant to carbapenem. These isolates carried at least two of the five bla genes examined, with the highest prevalence (87.4%) found for blaCTX-M (blaCTX-M3-like and blaCTX-M14-like), followed by blaCMY-2 (80.5%) and blaSHV (56.3%). The predominant virulence genes were the fimbriae gene fimH and the toxin genes cnf1 and hlyA in blood isolates and the capsule gene kpsMTII in UTI and blood isolates. Over 80% of the isolates carried yersiniabactin and aerobactin of siderophores. In 18 isolates, the fluoroquinolone-resistant ST131 isolate of pulsotypes I and II with blaCTX-M-15 was clonally disseminated in the hospital. The genomic plasticity of these ST131 occurred mainly through the conjugative plasmids with differences in replicon types A/C, I1, FIA, FIB and Y, size and number. In conclusion, MDR ESBL-producing E. coli isolates differed in virulence genes of UPEC and antibiotic resistance associated with the sources. Plasmid acquisition and chromosomal variations increase the spread of fluoroquinolone-resistant UPEC ST131 worldwide.
Optimal Design of Dualband CPW-FED G-Shaped Monopole Antenna for WLAN Application
Wen-Chung Liu
PIER , 2007, DOI: 10.2528/PIER07041401
Abstract: A dualband coplanar waveguide (CPW)-fed planar monopole antenna suitable for WLAN application is presented in this paper. The antenna resembling as a "G" shape and optimally designed by using the particle swarm optimization (PSO) algorithm can produce dual resonant modes and a much wider impedance bandwidth for the higher band. Prototypes of the obtained optimized antenna have been constructed and tested. The measured results explore good dualband operation with 10 dB impedance bandwidths of 9.7% and 62.8% at bands of 2.43 and 4.3 GHz, respectively, which cover the 2.4/5.2/5.8 GHz WLAN operating bands, and show good agreement with the numerical prediction. Also, good antenna performances such as radiation patterns and antenna gains over the operating bands have been observed.
Estimation of a Common Effect Parameter from Follow-Up Data When There Is No Mechanistic Interaction
Wen-Chung Lee
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0086374
Abstract: In a stratified analysis, the results from different strata if homogeneity assumption is met are pooled together to obtain a single summary estimate for the common effect parameter. However, the effect can appear homogeneous across strata using one measure but heterogeneous using another. Consequently, two researchers analyzing the same data can arrive at conflicting conclusions if they use different effect measures. In this paper, the author draws on the sufficient component cause model to develop a stratified-analysis method regarding a particular effect measure, the ‘peril ratio’. When there is no mechanistic interaction between the exposure under study and the stratifying variable (i.e., when they do not work together to complete any sufficient cause), the peril ratio is constant across strata. The author presents formulas for the estimation of such a common peril ratio. Three real data are re-analyzed for illustration. When the data is consistent with peril-ratio homogeneity in a stratified analysis, researchers can use the formulas in this paper to pool the strata.
Assessing Causal Mechanistic Interactions: A Peril Ratio Index of Synergy Based on Multiplicativity
Wen-Chung Lee
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0067424
Abstract: The assessments of interactions in epidemiology have traditionally been based on risk-ratio, odds-ratio or rate-ratio multiplicativity. However, many epidemiologists fail to recognize that this is mainly for statistical conveniences and often will misinterpret a statistically significant interaction as a genuine mechanistic interaction. The author adopts an alternative metric system for risk, the ‘peril’. A peril is an exponentiated cumulative rate, or simply, the inverse of a survival (risk complement) or one plus an odds. The author proposes a new index based on multiplicativity of peril ratios, the ‘peril ratio index of synergy based on multiplicativity’ (PRISM). Under the assumption of no redundancy, PRISM can be used to assess synergisms in sufficient cause sense, i.e., causal co-actions or causal mechanistic interactions. It has a less stringent threshold to detect a synergy as compared to a previous index of ‘relative excess risk due to interaction’. Using the new PRISM criterion, many situations in which there is not evidence of interaction judged by the traditional indices are in fact corresponding to bona fide positive or negative synergisms.
Substance P scavenger enhances antioxidant defenses and prevents prothrombotic effects on the rat lung after acute exposure to oil smoke
Li Ping-Chia, Lai I-Ju, Lin Yu-Ching, Chang Li-Ching, Chen Wen-Chung
Journal of Biomedical Science , 2009, DOI: 10.1186/1423-0127-16-58
Abstract: Rats were exposed to oil smoke for 120 min with or without 20 min pretreatment with lovastatin (substance P scavenger), L733060 (NK-1 receptor antagonist), vitamin E (antioxidant) or catechins (antioxidant). The levels of substance P and ROS were measured. Histological studies observed ROS damage in the form of HEL adducts. The prothrombotic effects of oil smoke exposure were measured by experimental induction of thrombosis in vivo.Oil smoke exposure significantly increased substance P levels, ROS levels, ROS damage (HEL adduct levels), and the size of experimentally induced thrombi. The pretreatments reduced all of these effects of oil smoke exposure; at many time points the reductions were statistically significant.We established a connection between oil smoke exposure and thrombosis which involves substance P and its receptor, the NK-1 receptor, and ROS. This study helps establish a mechanistic explanation of how airborne particulate matter can increase the risk of cardiovascular illness.A variety of chemical reactions occur while high temperature (150–400°C) cooking oils (e.g. sunflower oil, soybean oil, or lard) are being heated before food is added to the pan [1-3]. Several volatile chemicals such as formaldehyde, benzene, acetaldehyde and acrolein are present in fumes generated from frying and are thought to be associated with contents of cooking oil and foods [1-3]. Particulate air pollution is also generated and is associated with cardiovascular disease and myocardial infarction [4]. Indoor inhalation of atmospheric particulate matter (APM) from cooking has been associated with respiratory and cardiovascular diseases [5,6]. APM is as an important risk, particularly for cooks, in areas where pan-fry cooking is popular.Inhalation of the APM from cooking has been suggested to impact on the non-adrenergic and non-cholinergic (NANC) nervous system, leading to changes in breathing pattern, smooth muscle, or blood vessels in order to regulate visceral motility and
Engineering Human T Cells for Resistance to Methotrexate and Mycophenolate Mofetil as an In Vivo Cell Selection Strategy
Mahesh Jonnalagadda, Christine E. Brown, Wen-Chung Chang, Julie R. Ostberg, Stephen J. Forman, Michael C. Jensen
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0065519
Abstract: Gene transfer and drug selection systems that enforce ongoing transgene expression in vitro and in vivo which are compatible with human pharmaceutical drugs are currently underdeveloped. Here, we report on the utility of incorporating human enzyme muteins that confer resistance to the lymphotoxic/immunosuppressive drugs methotrexate (MTX) and mycophenolate mofetil (MMF) in a multicistronic lentiviral vector for in vivo T lymphocyte selection. We found that co-expression of human dihydrofolate reductase (DHFRFS; L22F, F31S) and inosine monophosphate dehydrogenase II (IMPDH2IY; T333I, S351Y) conferred T cell resistance to the cytocidal and anti-proliferative effects of these drugs at concentrations that can be achieved clinically (up to 0.1 μM MTX and 1.0 μM MPA). Furthermore, using a immunodeficient mouse model that supports the engraftment of central memory derived human T cells, in vivo selection studies demonstrate that huEGFRt+DHFRFS+IMPDH2IY+ T cells could be enriched following adoptive transfer either by systemic administration of MTX alone (4.4 -fold), MMF alone (2.9-fold), or combined MTX and MMF (4.9-fold). These findings demonstrate the utility of both DHFRFS/MTX and IMPDH2IY/MMF for in vivo selection of lentivirally transduced human T cells. Vectors incorporating these muteins in combination with other therapeutic transgenes may facilitate the selective engraftment of therapeutically active cells in recipients.
Synthesis of Vildagliptin-β-O-Glucuronide  [PDF]
Yansong Jack Lu, Yugang Liu, Mahavir Prashad, Wen-Chung Shieh
Advances in Chemical Engineering and Science (ACES) , 2012, DOI: 10.4236/aces.2012.23045
Abstract: A linear 7-step synthesis of vildagliptin-β-O-glucuronide (2) starting from commercially available D-glucurono-6, 3-lactone (3) was herein achieved with 11.3% overall yield. Efficient preparation of compound 6 in pure α form was obtained, which was proved critical to achieve high anomeric selectivity in β-O-glycosylation later. The direct β-O-glycosylation of vildagliptin (1) containing both a tertiary alcohol and a secondary amine was studied and achieved in good yield. The deprotection step to afford product was delicately executed to avoid hydrolysis of nitrile group. The target compound 2 was obtained after purification by reversed-phase C18 chromatography.
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