30 results on '"Yen C"'
Search Results
2. Post-phacoemulsification iris changes in eyes with glaucoma or glaucoma suspect status.
- Author
-
Qinyun Wang, Claudio I Perez, Marissé Masis, Max Feinstein, Marta Mora, Shan C Lin, and Yen C Hsia
- Subjects
Medicine ,Science - Abstract
PURPOSE:This prospective study used anterior segment optical coherence tomography (AS-OCT) to determine how phacoemulsification (phaco) changes iris parameters in eyes with glaucoma or glaucoma suspect status. METHODS:Using Visante AS-OCT (Carl Zeiss Meditec AG), the following pre- and post-phaco parameters were measured: IT750 = iris thickness at 750 μm from the scleral spur; IT2000 = iris thickness 2000 μm from the scleral spur; ITCM = the maximum iris thickness at the middle one third of the iris; ICURV = iris curvature; IAREA = iris area; and pupil size = pupil diameter (mm). Only high-quality images with an identifiable scleral spur were included, and only the nasal quadrant was analyzed. A single glaucoma specialist analyzed the parameters according to the Zhongshan Angle Assessment Program (ZAAP, Guangzhou, China). Multivariate analysis was performed using mixed effects regression correcting for age, gender, and ethnicity. RESULTS:89 subjects and 110 eyes were included in this study. The mean age of subjects was 74.83 {+/-} 8.69 years old. Most common diagnoses were POAG and glaucoma suspect (23% and 52%, respectively), and 16% of subjects had an LPI. In multivariate analysis of AS-OCT parameters, decreases in IT750, IT2000, ITCM, ICURV, and pupil size were statistically significant (p
- Published
- 2018
- Full Text
- View/download PDF
3. Classical acceleration temperature (CAT) in a box
- Author
-
Ahsan Mujtaba, Maksat Temirkhan, Yen Chin Ong, and Michael R. R. Good
- Subjects
Medicine ,Science - Abstract
Abstract A confined, non-relativistic, accelerating electron is shown to emit thermal radiation. Since laboratories face spatial constraints when dealing with rectilinear motion, focusing on a finite total travel distance combines the benefits of simple theoretical analysis with prospects for table-top experimentation. We demonstrate an accelerated moving charge along an asymptotically static worldline with fixed transit distance and non-relativistic maximum speed, emitting self-consistent analytic power, spectra, and energy. The classical radiation is Planck distributed with an associated acceleration temperature. This is the first fully parametrized, spectrum-solved, finite-distance worldline.
- Published
- 2024
- Full Text
- View/download PDF
4. The reproducibility and predictivity of radiomic features extracted from dynamic contrast-enhanced computed tomography of hepatocellular carcinoma.
- Author
-
Abdalla Ibrahim, Siddharth Guha, Lin Lu, Pengfei Geng, Qian Wu, Yen Chou, Hao Yang, Delin Wang, Lawrence H Schwartz, Chuan-Miao Xie, and Binsheng Zhao
- Subjects
Medicine ,Science - Abstract
PurposeTo assess the reproducibility of radiomic features (RFs) extracted from dynamic contrast-enhanced computed tomography (DCE-CT) scans of patients diagnosed with hepatocellular carcinoma (HCC) with regards to inter-observer variability and acquisition timing after contrast injection. The predictive ability of reproducible RFs for differentiating between the degrees of HCC differentiation is also investigated.MethodsWe analyzed a set of DCE-CT scans of 39 patients diagnosed with HCC. Two radiologists independently segmented the scans, and RFs were extracted from each sequence of the DCE-CT scans. The same lesion was segmented across the DCE-CT sequences of each patient's scan. From each lesion, 127 commonly used RFs were extracted. The reproducibility of RFs was assessed with regard to (i) inter-observer variability, by evaluating the reproducibility of RFs between the two radiologists; and (ii) timing of acquisition following contrast injection (inter- and intra-imaging phase). The reproducibility of RFs was assessed using the concordance correlation coefficient (CCC), with a cut-off value of 0.90. Reproducible RFs were used for building XGBoost classification models for the differentiation of HCC differentiation.ResultsInter-observer analyses across the different contrast-enhancement phases showed that the number of reproducible RFs was 29 (22.8%), 52 (40.9%), and 36 (28.3%) for the non-contrast enhanced, late arterial, and portal venous phases, respectively. Intra- and inter-sequence analyses revealed that the number of reproducible RFs ranged between 1 (0.8%) and 47 (37%), inversely related with time interval between the sequences. XGBoost algorithms built using reproducible RFs in each phase were found to be high predictive ability of the degree of HCC tumor differentiation.ConclusionsThe reproducibility of many RFs was significantly impacted by inter-observer variability, and a larger number of RFs were impacted by the difference in the time of acquisition after contrast injection. Our findings highlight the need for quality assessment to ensure that scans are analyzed in the same physiologic imaging phase in quantitative imaging studies, or that phase-wide reproducible RFs are selected. Overall, the study emphasizes the importance of reproducibility and quality control when using RFs as biomarkers for clinical applications.
- Published
- 2024
- Full Text
- View/download PDF
5. Machine learning-based identification of contrast-enhancement phase of computed tomography scans.
- Author
-
Siddharth Guha, Abdalla Ibrahim, Qian Wu, Pengfei Geng, Yen Chou, Hao Yang, Jingchen Ma, Lin Lu, Delin Wang, Lawrence H Schwartz, Chuan-Miao Xie, and Binsheng Zhao
- Subjects
Medicine ,Science - Abstract
Contrast-enhanced computed tomography scans (CECT) are routinely used in the evaluation of different clinical scenarios, including the detection and characterization of hepatocellular carcinoma (HCC). Quantitative medical image analysis has been an exponentially growing scientific field. A number of studies reported on the effects of variations in the contrast enhancement phase on the reproducibility of quantitative imaging features extracted from CT scans. The identification and labeling of phase enhancement is a time-consuming task, with a current need for an accurate automated labeling algorithm to identify the enhancement phase of CT scans. In this study, we investigated the ability of machine learning algorithms to label the phases in a dataset of 59 HCC patients scanned with a dynamic contrast-enhanced CT protocol. The ground truth labels were provided by expert radiologists. Regions of interest were defined within the aorta, the portal vein, and the liver. Mean density values were extracted from those regions of interest and used for machine learning modeling. Models were evaluated using accuracy, the area under the curve (AUC), and Matthew's correlation coefficient (MCC). We tested the algorithms on an external dataset (76 patients). Our results indicate that several supervised learning algorithms (logistic regression, random forest, etc.) performed similarly, and our developed algorithms can accurately classify the phase of contrast enhancement.
- Published
- 2024
- Full Text
- View/download PDF
6. MeCP2 SUMOylation rescues Mecp2-mutant-induced behavioural deficits in a mouse model of Rett syndrome
- Author
-
Yun L. Ma, Shau Y. Liu, Wei L. Hsu, Sin J. Cheng, Eminy H.Y. Lee, Yen C. Liu, and Derek J. C. Tai
- Subjects
0301 basic medicine ,Methyl-CpG-Binding Protein 2 ,SUMO protein ,General Physics and Astronomy ,medicine.disease_cause ,Hippocampus ,Rats, Sprague-Dawley ,Gene Knockout Techniques ,Mice ,0302 clinical medicine ,Conditional gene knockout ,Genetics ,Neurons ,Mutation ,Multidisciplinary ,Neuronal Plasticity ,biology ,Behavior, Animal ,Reverse Transcriptase Polymerase Chain Reaction ,Long-term potentiation ,Fear ,Immunohistochemistry ,Protein Inhibitors of Activated STAT ,Cell biology ,congenital, hereditary, and neonatal diseases and abnormalities ,Science ,Blotting, Western ,Genetic Vectors ,Rett syndrome ,In Vitro Techniques ,CREB ,General Biochemistry, Genetics and Molecular Biology ,Article ,MECP2 ,03 medical and health sciences ,Memory ,mental disorders ,medicine ,Rett Syndrome ,Animals ,Immunoprecipitation ,Learning ,Social Behavior ,CA1 Region, Hippocampal ,Lentivirus ,Sumoylation ,General Chemistry ,medicine.disease ,Rats ,nervous system diseases ,Disease Models, Animal ,030104 developmental biology ,Synaptic plasticity ,biology.protein ,Exploratory Behavior ,Mutagenesis, Site-Directed ,030217 neurology & neurosurgery - Abstract
The methyl-CpG-binding protein 2 (MeCP2) gene, MECP2, is an X-linked gene encoding the MeCP2 protein, and mutations of MECP2 cause Rett syndrome (RTT). However, the molecular mechanism of MECP2-mutation-caused RTT is less known. Here we find that MeCP2 could be SUMO-modified by the E3 ligase PIAS1 at Lys-412. MeCP2 phosphorylation (at Ser-421 and Thr-308) facilitates MeCP2 SUMOylation, and MeCP2 SUMOylation is induced by NMDA, IGF-1 and CRF in the rat brain. MeCP2 SUMOylation releases CREB from the repressor complex and enhances Bdnf mRNA expression. Several MECP2 mutations identified in RTT patients show decreased MeCP2 SUMOylation. Re-expression of wild-type MeCP2 or SUMO-modified MeCP2 in Mecp2-null neurons rescues the deficits of social interaction, fear memory and LTP observed in Mecp2 conditional knockout (cKO) mice. These results together reveal an important role of MeCP2 SUMOylation in social interaction, memory and synaptic plasticity, and that abnormal MeCP2 SUMOylation is implicated in RTT., Post-translational modifications of methyl-CpG-binding protein 2 (MeCP2) are important for its function and dysfunction in Rett syndrome. Here, Tai et al. show a functional interaction between MeCP2 SUMOylation and phosphorylation in rodent behavior and synaptic plasticity.
- Published
- 2016
7. Post-phacoemulsification iris changes in eyes with glaucoma or glaucoma suspect status
- Author
-
Shan C. Lin, Claudio I. Perez, Yen C. Hsia, Qinyun Wang, Marisse Masis, Max Feinstein, and Marta Mora
- Subjects
Male ,Eye Diseases ,genetic structures ,medicine.medical_treatment ,Iris ,Scleral spur ,Glaucoma ,Pupil ,Mathematical and Statistical Techniques ,0302 clinical medicine ,Medicine and Health Sciences ,Glaucoma surgery ,Ethnicities ,Postoperative Period ,Prospective Studies ,Aged, 80 and over ,Multidisciplinary ,medicine.diagnostic_test ,Statistics ,Ophthalmic Procedures ,Cataract Surgery ,Middle Aged ,Treatment Outcome ,medicine.anatomical_structure ,Physical Sciences ,Medicine ,Female ,Anatomy ,Tomography, Optical Coherence ,Research Article ,medicine.medical_specialty ,Ocular Anatomy ,Science ,Surgical and Invasive Medical Procedures ,Research and Analysis Methods ,03 medical and health sciences ,Optical coherence tomography ,Ocular System ,Ophthalmology ,medicine ,Humans ,Statistical Methods ,Iris (anatomy) ,Aged ,Phacoemulsification ,business.industry ,Biology and Life Sciences ,Cataract surgery ,medicine.disease ,eye diseases ,Multivariate Analysis ,People and Places ,030221 ophthalmology & optometry ,Eyes ,Population Groupings ,sense organs ,business ,Head ,Mathematics ,030217 neurology & neurosurgery ,Follow-Up Studies - Abstract
Purpose This prospective study used anterior segment optical coherence tomography (AS-OCT) to determine how phacoemulsification (phaco) changes iris parameters in eyes with glaucoma or glaucoma suspect status. Methods Using Visante AS-OCT (Carl Zeiss Meditec AG), the following pre- and post-phaco parameters were measured: IT750 = iris thickness at 750 μm from the scleral spur; IT2000 = iris thickness 2000 μm from the scleral spur; ITCM = the maximum iris thickness at the middle one third of the iris; ICURV = iris curvature; IAREA = iris area; and pupil size = pupil diameter (mm). Only high-quality images with an identifiable scleral spur were included, and only the nasal quadrant was analyzed. A single glaucoma specialist analyzed the parameters according to the Zhongshan Angle Assessment Program (ZAAP, Guangzhou, China). Multivariate analysis was performed using mixed effects regression correcting for age, gender, and ethnicity. Results 89 subjects and 110 eyes were included in this study. The mean age of subjects was 74.83 {+/-} 8.69 years old. Most common diagnoses were POAG and glaucoma suspect (23% and 52%, respectively), and 16% of subjects had an LPI. In multivariate analysis of AS-OCT parameters, decreases in IT750, IT2000, ITCM, ICURV, and pupil size were statistically significant (p
- Published
- 2018
8. The Effect of Multi-Session Prefrontal Cortical Stimulation on Aggression: A Randomized, Double-Blind, Parallel-Group Trial
- Author
-
Olivia Choy, Gary Tan, and Yen Cong Wong
- Subjects
aggression ,prefrontal ,non-invasive brain stimulation ,transcranial direct current stimulation ,violence ,Science - Abstract
Findings from brain imaging studies investigating the neural underpinnings of antisocial behavior have implicated the prefrontal cortex in the regulation of aggressive reactions. However, relatively few studies have examined the role of the prefrontal cortex on aggression in an experimental way. This study examines whether upregulating the prefrontal cortex using repeated transcranial direct current stimulation (tDCS) reduces aggressive behavior. In a double-blind, parallel-group, randomized controlled trial, 88 healthy adults (42 males, 46 females) were assigned to one session of anodal tDCS over the ventromedial prefrontal cortex (n = 47) or sham stimulation (n = 41) per day for three consecutive days and assessed using a behavioral measure of aggression. Levels of aggressive responses post-intervention did not significantly differ between the active and sham stimulation groups. However, a significant interaction effect between the stimulation group and gender was observed, whereby males, but not females, exhibited reduced aggression after prefrontal stimulation. To the authors’ knowledge, this is the first study to examine the effect of multi-session prefrontal tDCS on aggressive behavior in healthy adults. Results highlight that there are differences in responsivity to tDCS in modifying aggressive behavior.
- Published
- 2023
- Full Text
- View/download PDF
9. A hierarchical approach to removal of unwanted variation for large-scale metabolomics data
- Author
-
Taiyun Kim, Owen Tang, Stephen T. Vernon, Katharine A. Kott, Yen Chin Koay, John Park, David E. James, Stuart M. Grieve, Terence P. Speed, Pengyi Yang, Gemma A. Figtree, John F. O’Sullivan, and Jean Yee Hwa Yang
- Subjects
Science - Abstract
Mass spectrometry-based metabolomics is a powerful method for profiling large clinical cohorts but batch variations can obscure biologically meaningful differences. Here, the authors develop a computational workflow that removes unwanted data variation while preserving biologically relevant information.
- Published
- 2021
- Full Text
- View/download PDF
10. Stachyose triggers apoptotic like cell death in drought sensitive but not resilient plants
- Author
-
Pauline Okemo, Hao Long, Yen Cheng, Sagadevan Mundree, and Brett Williams
- Subjects
Medicine ,Science - Abstract
Abstract Programmed cell death (PCD) is one of the most intensively researched fields in modern mammalian biology with roles in cancer, aging, diabetes and numerous neurodegenerative diseases. It is becoming increasingly clear that PCD also plays significant roles in plant defence and responses to the environment. Given their unique ability to tolerate desiccation (cells remain viable even after they’ve lost 95% of their water), resurrection plants make ideal models to study the regulation of plant PCD pathways. Previously, we showed that the Australian resurrection plant, Tripogon loliiformis, suppresses plant PCD, via trehalose-mediated activation of autophagy pathways, during drying. In the present study, we created a full-length T. loliiformis cDNA library, performed a large-scale Agrobacterium screen for improved salinity tolerance and identified Stachyose synthase (TlStach) as a potential candidate for improving stress tolerance. Tripogon loliiformis shoots accumulate stachyose synthase transcripts and stachyose during drying. Attempts to generate transgenic plants expressing TlStach failed and were consistent with previous reports in mammals that demonstrated stachyose-mediated induction of apoptosis. Using a combination of transcriptomics, metabolomics and cell death assays (TUNNEL and DNA laddering), we investigated whether stachyose induces apoptotic-like cell death in T. loliiformis. We show that stachyose triggers the formation of the hallmarks of plant apoptotic-like cell death in the desiccation sensitive Nicotiana benthamiana but not the resilient T. loliiformis. These findings suggest that T. loliiformis suppresses stachyose-mediated apoptotic-like cell death and provides insights on the role of sugar metabolism and plant PCD pathways. A better understanding of how resilient plants regulate sugar metabolism and PCD pathways may facilitate future targeting of plant metabolic pathways for increased stress tolerance.
- Published
- 2021
- Full Text
- View/download PDF
11. Gut microbiota impact on the peripheral immune response in non-alcoholic fatty liver disease related hepatocellular carcinoma
- Author
-
Jason Behary, Nadia Amorim, Xiao-Tao Jiang, Anita Raposo, Lan Gong, Emily McGovern, Ragy Ibrahim, Francis Chu, Carlie Stephens, Hazem Jebeili, Vincenzo Fragomeli, Yen Chin Koay, Miriam Jackson, John O’Sullivan, Martin Weltman, Geoffrey McCaughan, Emad El-Omar, and Amany Zekry
- Subjects
Science - Abstract
Disease-specific gut microbiome signatures have been previously defined for patients with liver cirrhosis or hepatocellular carcinoma (HCC). Here the authors examine the composition of the gut microbiota in cirrhotic patients with non-alcoholic fatty liver disease with or without HCC and evaluate how dysbiosis influences peripheral immune responses.
- Published
- 2021
- Full Text
- View/download PDF
12. Core functional nodes and sex-specific pathways in human ischaemic and dilated cardiomyopathy
- Author
-
Mengbo Li, Benjamin L. Parker, Evangeline Pearson, Benjamin Hunter, Jacob Cao, Yen Chin Koay, Oneka Guneratne, David E. James, Jean Yang, Sean Lal, and John F. O’Sullivan
- Subjects
Science - Abstract
Study of human heart failure is limited by access to human tissue. Here, the authors apply multi-omic screening in human ischaemic and dilated myocardial tissue and matched controls to determine molecular changes common and unique to each aetiology and to reveal differences between male and female hearts.
- Published
- 2020
- Full Text
- View/download PDF
13. The RNA-binding protein HuR is a negative regulator in adipogenesis
- Author
-
Diana Teh Chee Siang, Yen Ching Lim, Aung Maung Maung Kyaw, Khaing Nwe Win, Sook Yoong Chia, Ufuk Degirmenci, Xiang Hu, Bryan C. Tan, Arcinas Camille Esther Walet, Lei Sun, and Dan Xu
- Subjects
Science - Abstract
Human antigen R (HuR) is an RNA binding protein that promotes mRNA stability. Here the authors show that HuR represses adipogenesis in white and brown adipose tissue by stabilizing Insig1 and other targets.
- Published
- 2020
- Full Text
- View/download PDF
14. Photosynthesis-inspired H2 generation using a chlorophyll-loaded liposomal nanoplatform to detect and scavenge excess ROS
- Author
-
Wei-Lin Wan, Bo Tian, Yu-Jung Lin, Chiranjeevi Korupalli, Ming-Yen Lu, Qinghua Cui, Dehui Wan, Yen Chang, and Hsing-Wen Sung
- Subjects
Science - Abstract
Hydrogen can be used to reduce the concentration of reactive oxygen species (ROS), but its delivery to diseased tissues is challenging due to its low solubility. Here the authors develop a photosynthesis-inspired FRET nanocomplex to detect and scavenge local excess of ROS in the tissue using photocatalytic hydrogen production.
- Published
- 2020
- Full Text
- View/download PDF
15. TRAIL-Expressing Monocyte/Macrophages Are Critical for Reducing Inflammation and Atherosclerosis
- Author
-
Siân P. Cartland, Scott W. Genner, Gonzalo J. Martínez, Stacy Robertson, Maaike Kockx, Ruby CY. Lin, John F. O'Sullivan, Yen Chin Koay, Pradeep Manuneedhi Cholan, Melkam A. Kebede, Andrew J. Murphy, Seth Masters, Martin R. Bennett, Wendy Jessup, Leonard Kritharides, Carolyn Geczy, Sanjay Patel, and Mary M. Kavurma
- Subjects
Science - Abstract
Summary: Circulating tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) levels are reduced in patients with cardiovascular disease, and TRAIL gene deletion in mice exacerbates atherosclerosis and inflammation. How TRAIL protects against atherosclerosis and why levels are reduced in disease is unknown. Here, multiple strategies were used to identify the protective source of TRAIL and its mechanism(s) of action. Samples from patients with coronary artery disease and bone-marrow transplantation experiments in mice lacking TRAIL revealed monocytes/macrophages as the main protective source. Accordingly, deletion of TRAIL caused a more inflammatory macrophage with reduced migration, displaying impaired reverse cholesterol efflux and efferocytosis. Furthermore, interleukin (IL)-18, commonly increased in plasma of patients with cardiovascular disease, negatively regulated TRAIL transcription and gene expression, revealing an IL-18-TRAIL axis. These findings demonstrate that TRAIL is protective of atherosclerosis by modulating monocyte/macrophage phenotype and function. Manipulating TRAIL levels in these cells highlights a different therapeutic avenue in the treatment of cardiovascular disease. : Pathophysiology; Molecular Mechanism of Behavior; Diabetology; Immunology; Immune Response Subject Areas: Pathophysiology, Molecular Mechanism of Behavior, Diabetology, Immunology, Immune Response
- Published
- 2019
- Full Text
- View/download PDF
16. Does catheter material affect functional performance of intravenous ports via the superior vena cava?
- Author
-
Ching-Feng Wu, Jui-Ying Fu, Tsai-Yang Hsieh, Chi-Tsung Wen, Sheng-Yueh Yu, Ming-Ju Hsieh, Yen Chu, and Ching-Yang Wu
- Subjects
Medicine ,Science - Abstract
Introduction The catheter is the only intravascular portion of an implanted port and plays a crucial role in catheter related complications. Both polyurethane and silicone are biocompatible materials which are utilized for catheter manufacturing, but their correlation to complications remains controversial. The aim of this study was to try to analyze the relationship between catheter materials and complications. Materials and methods A total of 3144 patients who underwent intravenous port implantation between March 2012 and December 2018 at Chang Gung Memorial Hospital, Linkou, Taiwan were recruited. Of these, 1226 patients received silicone catheter port implantation and 1679 received polyurethane catheter ports. Case matching was done prior to analysis and catheter related complications and cumulative complication incidence for each group were compared. Results Intergroup differences were identified in entry vessel (p = 0.0441), operation year (p < 0.0001), operation method (p = 0.0095), functional period (p < 0.0001), patient follow up status (p < 0.0001), operating time for vessel cutdown (p < 0.0001) and wire assisted approach (p = 0.0008). Stratified by specific entry vessel, no statistical difference was found in complication rate or incidence between the silicone and polyurethane groups. We further compared the cumulative complication incidence of the silicone and polyurethane groups, and also found no statistical difference (p = 0.4451). Conclusion As long as external stress forces generated by surrounding structures and focused on potential weak points are avoided, both silicone and polyurethane materials provide sufficient structural stability to serve as reliable vascular access for patients.
- Published
- 2021
17. Batch adsorption and isothermic studies of malachite green dye adsorption using Leucaena leucocephala biomass as potential adsorbent in water treatment
- Author
-
Yen Chen Lee, Mohd Hazim Mohamad Amini, Nurul Syuhada Sulaiman, Mohamed Mazlan, and Jia Geng Boon
- Subjects
adsorption ,malachite green ,batch adsorption ,Langmuir ,Freundlich ,Leucaena leucocephala ,Technology ,Technology (General) ,T1-995 ,Science ,Science (General) ,Q1-390 - Abstract
The adsorption properties of Leucaena leucocephala biomass to clean malachite green contaminated water were investigated in this work. BET surface analysis showed a surface area of 0.5724 m²/g. Batch adsorption studies and isothermic studies determined that the best time and temperature for the adsorption process to become efficient were 60 min of contact time and 25 °C, respectively. The KF value of 0.3372 mg adsorbed per mg of adsorbent of the L. leucocephala biomass for malachite green was the highest at 50 °C. It was shown that the n values were n
- Published
- 2018
- Full Text
- View/download PDF
18. Topologically knotted deubiquitinases exhibit unprecedented mechanostability to withstand the proteolysis by an AAA+ protease
- Author
-
Manoj Kumar Sriramoju, Yen Chen, Yun-Tzai Cloud Lee, and Shang-Te Danny Hsu
- Subjects
Medicine ,Science - Abstract
Abstract More than one thousand knotted protein structures have been identified so far, but the functional roles of these knots remain elusive. It has been postulated that backbone entanglement may provide additional mechanostability. Here, we employed a bacterial proteasome, ClpXP, to mechanically unfold 52-knotted human ubiquitin C-terminal hydrolase (UCH) paralogs from their C-termini, followed by processive translocation into the proteolytic chamber for degradation. Our results revealed unprecedentedly slow kinetics of ClpXP-mediated proteolysis for the proteasome-associated UCHL5: ten thousand times slower than that of a green fluorescence protein (GFP), which has a comparable size to the UCH domain but much higher chemical and thermal stabilities. The ClpXP-dependent mechanostability positively correlates with the intrinsic unfolding rates of the substrates, spanning over several orders of magnitude for the UCHs. The broad range of mechanostability within the same protein family may be associated with the functional requirements for their differential malleabilities.
- Published
- 2018
- Full Text
- View/download PDF
19. De novo reconstruction of human adipose transcriptome reveals conserved lncRNAs as regulators of brown adipogenesis
- Author
-
Chunming Ding, Yen Ching Lim, Sook Yoong Chia, Arcinas Camille Esther Walet, Shaohai Xu, Kinyui Alice Lo, Yanling Zhao, Dewen Zhu, Zhihui Shan, Qingfeng Chen, Melvin Khee-Shing Leow, Dan Xu, and Lei Sun
- Subjects
Science - Abstract
Long non-coding RNAs are known to regulate mouse white adipose tissue development and brown adipose tissue program expression. Here, the authors construct a roadmap for human long non-coding RNAs expressed in fetal brown adipose tissue, adult omental and subcutaneous white adipose tissues.
- Published
- 2018
- Full Text
- View/download PDF
20. Phloretin Ameliorates Testosterone-Induced Benign Prostatic Hyperplasia in Rats by Regulating the Inflammatory Response, Oxidative Stress and Apoptosis
- Author
-
Chao Yu Hsu, Yi Sheng Lin, Wei Chun Weng, Lauren Panny, Hsiang Lai Chen, Min Che Tung, Yen Chuan Ou, Chi Chien Lin, and Che Hsueh Yang
- Subjects
prostatic hyperplasia ,phloretin ,anti-inflammatory ,antioxidants ,apoptosis ,Science - Abstract
The inflammatory process is proposed to be one of the factors to benign prostatic enlargement (BPH), and this is the first study examining the anti-inflammatory ability of phloretin in treating rats with testosterone-induced BPH. BPH would be induced by testosterone (10 mg/kg/day testosterone subcutaneously for 28 days), and the other groups of rats were treated with phloretin 50 mg/kg/day or 100 mg/kg/day orally (phr50 or phr100 group) after induction. Prostate weight and prostate weight to body weight ratio were significantly reduced in the Phr100 group. Reduced dihydrotestosterone without interfering with 5α-reductase was observed in the phr100 group. In inflammatory proteins, reduced IL-6, IL-8, IL-17, NF-κB, and COX-2 were seen in the phr100 group. In reactive oxygen species, malondialdehyde was reduced, and superoxide dismutase and glutathione peroxidase were elevated in the phr100 group. In apoptotic assessment, elevated cleaved caspase-3 was observed in rats of the phr100 group. Enhanced pro-apoptotic Bax and reduced anti-apoptotic Bc1-2 could be seen in the phr100 group. In histological stains, markedly decreased glandular hyperplasia and proliferative cell nuclear antigen were observed with reduced expression in the phr100 group. Meanwhile, positive cells of terminal deoxynucleotidyl transferase dUTP nick end labeling were increased in the phr100 group. In conclusion, the treatment of phloretin 100 mg/kg/day could ameliorate testosterone-induced BPH.
- Published
- 2021
- Full Text
- View/download PDF
21. Recommended irrigation volume for an intravenous port: Ex vivo simulation study.
- Author
-
Ching-Yang Wu, Chia-Hui Cheng, Jui-Ying Fu, Yen Chu, Ching-Feng Wu, Chien-Hung Chiu, Po-Jen Ko, and Yun-Hen Liu
- Subjects
Medicine ,Science - Abstract
BACKGROUND:An intravenous port, which differs from a central venous catheter, has an injection chamber at the end of the catheter. This structural difference causes the irrigation flow pattern to be quite different from that of the central venous catheter. Furthermore, the intraluminal volume differs due to the size of the injection chamber and implanted catheter length. Hence, the ideal recommended irrigation volume varies because of differences in intraluminal volume, however, the recommended irrigation volume is 10 ml and may be a cause for reported port malfunctions. This study investigates the best irrigation volume for an intravenous port by simulating the clinical scenario ex-vivo to access its usefulness. MATERIALS AND METHODS:This study was composed of two tests. The irrigation volume test attempted to quantify the irrigation volume of an implanted port while the irrigation rate test attempted to simulate daily nursing practice in order to clarify the effect of irrigation flow. The human blood needed for the simulation was donated by volunteers and the total volume was 10 ml per test. The irrigation volume test was done by syringe pump with varying pre-set irrigation volume after the port and connected catheter were filled with volunteer blood. After irrigation with pre-set volume, the retained intraluminal solution was collected and quantified by Bradford assay in order to titrate the best irrigation volume. The irrigation rate test tried to simulate daily maintenance practice in different settings with the quantified irrigation volume as identified by the irrigation volume test. The retained intraluminal solution was collected and quantified by Bradford assay in order to confirm the efficacy of the quantified irrigation volume. RESULTS:In both SVC and IVC ports, we identified the twenty times the intravascular volume as sufficient for a complete wash out of the blood component in the irrigation volume test. The minimal irrigation volume for SVC and IVC port were 10 ml and 15.6 ml respectively. In irrigation rate test, the irrigation for SVC and IVC port was 10 and 20 ml, respectively, for the sake of preparation convenience. We not only identified the importance of preparation, i.e. irrigation of the extension line but also confirmed the efficacy of the recommended irrigation volume. CONCLUSION:The irrigation volume should be varied according to the intraluminal volume. Maintenance should be performed after the extension line has been irrigated. The recommended port irrigation volume for SVC and IVC route were 10 and 20 ml, respectively.
- Published
- 2018
- Full Text
- View/download PDF
22. A complex association between DNA methylation and gene expression in human placenta at first and third trimesters.
- Author
-
Yen Ching Lim, Jie Li, Yiyun Ni, Qi Liang, Junjiao Zhang, George S H Yeo, Jianxin Lyu, Shengnan Jin, and Chunming Ding
- Subjects
Medicine ,Science - Abstract
The human placenta is a maternal-fetal organ essential for normal fetal development and maternal health. During pregnancy, the placenta undergoes many structural and functional changes in response to fetal needs and environmental exposures. Previous studies have demonstrated widespread epigenetic and gene expression changes from early to late pregnancy. However, on the global level, how DNA methylation changes impact on gene expression in human placenta is not yet well understood. We performed DNA methylome analysis by reduced representation bisulfite sequencing (RRBS) and gene expression analysis by RNA-Seq for both first and third trimester human placenta tissues. From first to third trimester, 199 promoters (corresponding to 189 genes) and 2,297 gene bodies were differentially methylated, with a clear dominance of hypermethylation (96.8% and 93.0% for promoters and gene bodies, respectively). A total of 2,447 genes were differentially expressed, of which 77.2% were down-regulated. Gene ontology analysis using differentially expressed genes were enriched for cell cycle and immune response functions. The correlation between DNA methylation and gene expression was non-linear and complex, depending on the genomic context (promoter or gene body) and gene expression levels. A wide range of DNA methylation and gene expression changes were observed at different gestational ages. The non-linear association between DNA methylation and gene expression indicates that epigenetic regulation of placenta development is more complex than previously envisioned.
- Published
- 2017
- Full Text
- View/download PDF
23. Role of sarcoplasmic reticulum calcium in development of secondary calcium rise and early afterdepolarizations in long QT syndrome rabbit model.
- Author
-
Po-Cheng Chang, Hung-Ta Wo, Hui-Ling Lee, Shien-Fong Lin, Ming-Shien Wen, Yen Chu, San-Jou Yeh, and Chung-Chuan Chou
- Subjects
Medicine ,Science - Abstract
BACKGROUND:L-type calcium current reactivation plays an important role in development of early afterdepolarizations (EADs) and torsades de pointes (TdP). Secondary intracellular calcium (Cai) rise is associated with initiation of EADs. OBJECTIVE:To test whether inhibition of sarcoplasmic reticulum (SR) Ca2+ cycling suppresses secondary Cai rise and genesis of EADs. METHODS:Langendorff perfusion and dual voltage and Cai optical mapping were conducted in 10 rabbit hearts. Atrioventricular block (AVB) was created by radiofrequency ablation. After baseline studies, E4031, SR Ca2+ cycling inhibitors (ryanodine plus thapsigargin) and nifedipine were then administrated subsequently, and the protocols were repeated. RESULTS:At baseline, there was no spontaneous or pacing-induced TdP. After E4031 administration, action potential duration (APD) was significantly prolonged and the amplitude of secondary Cai rise was enhanced, and 7 (70%) rabbits developed spontaneous or pacing-induced TdP. In the presence of ryanodine plus thapsigargin, TdP inducibility was significantly reduced (2 hearts, 20%, p = 0.03). Although APD was significantly prolonged (from 298 ± 30 ms to 457 ± 75 ms at pacing cycle length of 1000 m, p = 0.007) by ryanodine plus thapsigargin, the secondary Cai rise was suppressed (from 8.8 ± 2.6% to 1.2 ± 0.9%, p = 0.02). Nifedipine inhibited TdP inducibility in all rabbit hearts. CONCLUSION:In this AVB and long QT rabbit model, inhibition of SR Ca2+ cycyling reduces the inducibility of TdP. The mechanism might be suppression of secondary Cai rise and genesis of EADs.
- Published
- 2015
- Full Text
- View/download PDF
24. Directed differentiation of embryonic stem cells using a bead-based combinatorial screening method.
- Author
-
Marina Tarunina, Diana Hernandez, Christopher J Johnson, Stanislav Rybtsov, Vidya Ramathas, Mylvaganam Jeyakumar, Thomas Watson, Lilian Hook, Alexander Medvinsky, Chris Mason, and Yen Choo
- Subjects
Medicine ,Science - Abstract
We have developed a rapid, bead-based combinatorial screening method to determine optimal combinations of variables that direct stem cell differentiation to produce known or novel cell types having pre-determined characteristics. Here we describe three experiments comprising stepwise exposure of mouse or human embryonic cells to 10,000 combinations of serum-free differentiation media, through which we discovered multiple novel, efficient and robust protocols to generate a number of specific hematopoietic and neural lineages. We further demonstrate that the technology can be used to optimize existing protocols in order to substitute costly growth factors with bioactive small molecules and/or increase cell yield, and to identify in vitro conditions for the production of rare developmental intermediates such as an embryonic lymphoid progenitor cell that has not previously been reported.
- Published
- 2014
- Full Text
- View/download PDF
25. Comparison of IHC, FISH and RT-PCR methods for detection of ALK rearrangements in 312 non-small cell lung cancer patients in Taiwan.
- Author
-
Yi-Cheng Wu, Il-Chi Chang, Chi-Liang Wang, Tai-Di Chen, Ya-Ting Chen, Hui-Ping Liu, Yen Chu, Yu-Ting Chiu, Tzu-Hua Wu, Li-Hui Chou, Yi-Rong Chen, and Shiu-Feng Huang
- Subjects
Medicine ,Science - Abstract
Recently Echinoderm microtubule-associated protein-like 4- anaplastic lymphoma kinase (EML4-ALK) fusion gene has become an important biomarker for ALK tyrosine kinase inhibitor (crizotinib) treatment in NSCLC. However, the best detection method and the significance of EML4-ALK variant types remain uncertain.Reverse transcriptase-polymerase chain reaction (RT-PCR), fluorescence in Situ hybridization (FISH) and Immunohistochemical (IHC) stain were performed on tumor tissues of 312 NSCLC patients for detection of ALK rearrangements. Mutation analyses for EGFR and KRAS genes were also performed.Thirteen of the 312 patients (4.17%) had ALK rearrangements detected by RT-PCR. If RT-PCR data was used as the gold standard, FISH tests had a low sensitivity (58.33%), but very good specificity (99.32%). IHC stain had better sensitivity (91.67%) than FISH, but lower specificity (79.52%), when the cut off was IHC2+. All of the 8 patients with high abundance of EML4-ALK positive cells in tumor tissues (assessed by the signal intensities of the RT-PCR product), were also have high expression of ALK protein (IHC3+), and positive for FISH, except one failed in FISH. Variants 3a+3b (4/5, 80%) of EML4-ALK fusion gene were more common to have high abundance of EML4-ALK positive cells in tumor tissues than variant 1 (1/3, 33.3%). Meta-analysis of the published data of 2273 NSCLC patients revealed that variant 3 (23/44, 52.3%) was the most common type in Chinese population, while variant 1 (28/37, 75.7%) was most common in Caucasian.Among the three detection methods, RT-PCR could detect not only the presence of EML4-ALK fusion gene and their variant types, but also the abundance of EML4-ALK positive cells in NSCLC tumor tissues. The latter two factors might affect the treatment response to anti-ALK inhibitor. Including RT-PCR as a diagnostic test for ALK inhibitor treatment in the prospective clinical trials is recommended.
- Published
- 2013
- Full Text
- View/download PDF
26. Comparison of hemodynamic and inflammatory changes between transoral and transthoracic thoracoscopic surgery.
- Author
-
Yen Chu, Chien-Ying Liu, Yi-Cheng Wu, Ming-Ju Hsieh, Tzu-Ping Chen, Ying-Kai Chao, Ching-Yang Wu, Hsu-Chia Yuan, Po-Jen Ko, Yun-Hen Liu, and Hui-Ping Liu
- Subjects
Medicine ,Science - Abstract
BACKGROUND: Natural orifice transluminal endoscopy has been developed for abdominal surgical procedures. The aim of this study was to compare the surgical outcome between a novel transoral approach and a standard transthoracic approach for the thoracic cavity in a canine model. METHODS: Twenty-eight dogs were assigned to transoral (n = 14) or standard thoracoscopy (n = 14). Each group underwent thoracic exploration, pre-determined surgical lung biopsy, and pericardial window creation. Blood draws were obtained before surgery and at postoperative days 1, 3, 7, and 14. Operative time, complications, laboratory parameters, hemodynamic parameters, and inflammatory parameters were compared between the two procedures. The animals were monitored for two weeks and necropsy were performed for surgical outcome evaluation. RESULTS: The thoracic procedures were successfully performed in all of the dogs, with the exception of one animal in the transoral group. There were no serious acute or delayed complications related to surgery. There was no difference between the two surgical groups for each of the hemodynamic parameters that were evaluated. Regarding the immunological impact of the surgeries, transoral thoracoscopy was associated with significant elevations in interleukin 6 and c-reactive protein levels on postoperative days 1 and 3, respectively, when compared with the standard thoracoscopy. All dogs recovered well, without signs of mediastinitis or thoracic infection. Necropsy revealed absence of infection, no injury to vital organs, and confirmed the success of the novel procedure. CONCLUSIONS: This study suggests that both techniques were comparable with respect to procedure success rate, hemodynamic impact, and inflammatory changes. Furthermore, there was no difference in the incidence of postoperative discomfort between groups.
- Published
- 2013
- Full Text
- View/download PDF
27. Paraoxonase-1 is not a major determinant of stent thrombosis in a Taiwanese population.
- Author
-
Dong-Yi Chen, Chao-Yung Wang, Ming-Shien Wen, Tsong-Hai Lee, Yen Chu, Ming-Jer Hsieh, Shang-Hung Chang, Cheng-Hung Lee, Jian-Liang Wang, Chun-Chi Chen, Laing-Suei Lu, Ming-Ta Lee, San-Jou Yeh, Fun-Chiung Lin, and I-Chang Hsieh
- Subjects
Medicine ,Science - Abstract
Clopidogrel is a prodrug that undergoes in vivo bioactivation to show its antiplatelet effects. Recent studies have shown that cytochrome P450 (CYP), ATP-binding cassette transporters (ABCB1), and paraoxonase-1 (PON1) play crucial roles in clopidogrel bioactivation. Here, we aim to determine the effects of genetic polymorphisms of CYP (CYP 2C19*2, CYP 2C19*3, and CYP 2C19*17), ABCB1 (ABCB1 3435C>T, ABCB1 129T>C, and ABCB1 2677G>T/A), and PON1 (PON1 Q192R, PON1 L55M, and PON1 108C>T) on the development of stent thrombosis (ST) in patients receiving clopidogrel after percutaneous coronary intervention (PCI).We evaluated the incidence of ST (0.64%) in 4964 patients who were recruited in the CAPTAIN registry (Cardiovascular Atherosclerosis and Percutaneous TrAnsluminal INterventions). The presence of genetic polymorphisms was assessed in 20 subjects who developed ST after aspirin and clopidogrel therapy and in 40 age- and sex-matched control subjects who did not develop ST, which was documented after 9 months of angiographic follow-up. ST was acute in 5 subjects, subacute in 7, late in 7, and very late in 1. The presence of CYP 2C19*2 allele was significantly associated with ST (adjusted odds ratio [ORadj]: 4.20, 95% confidence interval [CI], 1.263-9.544; P = 0.031). However, genetic variations in PON1 and ABCB1 showed no significant association with ST.We conclude that in a Taiwanese population, PON1 Q192R genotype is not associated with ST development after PCI. However, the presence of CYP 2C19*2 allele is a risk factor for ST development after PCI.
- Published
- 2012
- Full Text
- View/download PDF
28. Calpain/SHP-1 interaction by honokiol dampening peritoneal dissemination of gastric cancer in nu/nu mice.
- Author
-
Shing Hwa Liu, Keh Bin Wang, Keng Hsin Lan, Wen Jane Lee, Hung Chuan Pan, Sheng Mao Wu, Yen Chun Peng, Yi Ching Chen, Chin Chang Shen, Hsu Chen Cheng, Ko Kaung Liao, and Meei Ling Sheu
- Subjects
Medicine ,Science - Abstract
BACKGROUND: Honokiol, a small-molecular weight natural product, has previously been reported to activate apoptosis and inhibit gastric tumorigenesis. Whether honokiol inhibits the angiogenesis and metastasis of gastric cancer cells remains unknown. METHODOLOGY/PRINCIPAL FINDINGS: We tested the effects of honokiol on angiogenic activity and peritoneal dissemination using in vivo, ex vivo and in vitro assay systems. The signaling responses in human gastric cancer cells, human umbilical vascular endothelial cells (HUVECs), and isolated tumors were detected and analyzed. In a xenograft gastric tumor mouse model, honokiol significantly inhibited the peritoneal dissemination detected by PET/CT technique. Honokiol also effectively attenuated the angiogenesis detected by chick chorioallantoic membrane assay, mouse matrigel plug assay, rat aortic ring endothelial cell sprouting assay, and endothelial cell tube formation assay. Furthermore, honokiol effectively enhanced signal transducer and activator of transcription (STAT-3) dephosphorylation and inhibited STAT-3 DNA binding activity in human gastric cancer cells and HUVECs, which was correlated with the up-regulation of the activity and protein expression of Src homology 2 (SH2)-containing tyrosine phosphatase-1 (SHP-1). Calpain-II inhibitor and siRNA transfection significantly reversed the honokiol-induced SHP-1 activity. The decreased STAT-3 phosphorylation and increased SHP-1 expression were also shown in isolated peritoneal metastatic tumors. Honokiol was also capable of inhibiting VEGF generation, which could be reversed by SHP-1 siRNA transfection. CONCLUSIONS/SIGNIFICANCE: Honokiol increases expression and activity of SPH-1 that further deactivates STAT3 pathway. These findings also suggest that honokiol is a novel and potent inhibitor of angiogenesis and peritoneal dissemination of gastric cancer cells, providing support for the application potential of honokiol in gastric cancer therapy.
- Published
- 2012
- Full Text
- View/download PDF
29. Tailor-made zinc-finger transcription factors activate FLO11 gene expression with phenotypic consequences in the yeast Saccharomyces cerevisiae.
- Author
-
Jia-Ching Shieh, Yu-Che Cheng, Mao-Chang Su, Michael Moore, Yen Choo, and Aaron Klug
- Subjects
Medicine ,Science - Abstract
Cys2His2 zinc fingers are eukaryotic DNA-binding motifs, capable of distinguishing different DNA sequences, and are suitable for engineering artificial transcription factors. In this work, we used the budding yeast Saccharomyces cerevisiae to study the ability of tailor-made zinc finger proteins to activate the expression of the FLO11 gene, with phenotypic consequences. Two three-finger peptides were identified, recognizing sites from the 5' UTR of the FLO11 gene with nanomolar DNA-binding affinity. The three-finger domains and their combined six-finger motif, recognizing an 18-bp site, were fused to the activation domain of VP16 or VP64. These transcription factor constructs retained their DNA-binding ability, with the six-finger ones being the highest in affinity. However, when expressed in haploid yeast cells, only one three-finger recombinant transcription factor was able to activate the expression of FLO11 efficiently. Unlike in the wild-type, cells with such transcriptional activation displayed invasive growth and biofilm formation, without any requirement for glucose depletion. The VP16 and VP64 domains appeared to act equally well in the activation of FLO11 expression, with comparable effects in phenotypic alteration. We conclude that the functional activity of tailor-made transcription factors in cells is not easily predicted by the in vitro DNA-binding activity.
- Published
- 2007
- Full Text
- View/download PDF
30. PI3Ks maintain the structural integrity of T-tubules in cardiac myocytes.
- Author
-
Chia-Yen C Wu, Zhiheng Jia, Wei Wang, Lisa M Ballou, Ya-Ping Jiang, Biyi Chen, Richard T Mathias, Ira S Cohen, Long-Sheng Song, Emilia Entcheva, and Richard Z Lin
- Subjects
Medicine ,Science - Abstract
Phosphoinositide 3-kinases (PI3Ks) regulate numerous physiological processes including some aspects of cardiac function. Although regulation of cardiac contraction by individual PI3K isoforms has been studied, little is known about the cardiac consequences of downregulating multiple PI3Ks concurrently.Genetic ablation of both p110α and p110β in cardiac myocytes throughout development or in adult mice caused heart failure and death. Ventricular myocytes from double knockout animals showed transverse tubule (T-tubule) loss and disorganization, misalignment of L-type Ca(2+) channels in the T-tubules with ryanodine receptors in the sarcoplasmic reticulum, and reduced Ca(2+) transients and contractility. Junctophilin-2, which is thought to tether T-tubules to the sarcoplasmic reticulum, was mislocalized in the double PI3K-null myocytes without a change in expression level.PI3K p110α and p110β are required to maintain the organized network of T-tubules that is vital for efficient Ca(2+)-induced Ca(2+) release and ventricular contraction. PI3Ks maintain T-tubule organization by regulating junctophilin-2 localization. These results could have important medical implications because several PI3K inhibitors that target both isoforms are being used to treat cancer patients in clinical trials.
- Published
- 2011
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.