Publications by authors named "Yi-Jen Huang"

27 Publications

  • Page 1 of 1

Association Between Statin Use and Exacerbation of Chronic Obstructive Pulmonary Disease Among Patients Receiving Corticosteroids.

Int J Chron Obstruct Pulmon Dis 2021 5;16:591-602. Epub 2021 Mar 5.

Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.

Purpose: The role of statins as anti-inflammatory drugs in chronic obstructive pulmonary disease (COPD) is controversial. This study aimed to determine the efficacy of statins used with or without corticosteroids in COPD patients.

Patients And Methods: This was a retrospective cohort study and used the two million outpatients and inpatients in Taiwan's Longitudinal Health Insurance Database covering 2000 to 2015. A total of 92,460 patients were identified in this study. We divided COPD patients into four groups by auditing each patient's medication (statins used or not; corticosteroids used or not) and used Cox regression to analyze and compare the effects of statins in COPD patients with or without corticosteroids.

Results: In terms of all COPD patients, our findings were consistent with previous studies showing that statins decreased COPD-related hospitalization and mortality rates. However, the beneficial effects were only observed in younger patients or those not taking corticosteroids in further analysis. Statins significantly decreased hospitalization and mortality rates in the non-corticosteroids groups. The hazard ratios increased with age and were not statistically significant for patients > 70 years old. Statins did not significantly decrease ED visits, hospitalization, and mortality in corticosteroids groups.

Conclusion: Statins decreased hospitalization and mortality rates in COPD patients not taking corticosteroids but were not efficacious in patients on corticosteroids therapy. Furthermore, the beneficial effects of statins gradually decreased with patient age. Based on the findings, statins used in COPD patients may need to consider the patient age and corticosteroids used or not.
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http://dx.doi.org/10.2147/COPD.S292026DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7944644PMC
March 2021

A panel of anti-influenza virus nucleoprotein antibodies selected from phage-displayed synthetic antibody libraries with rapid diagnostic capability to distinguish diverse influenza virus subtypes.

Sci Rep 2020 08 7;10(1):13318. Epub 2020 Aug 7.

Genomics Research Center, Academia Sinica, 128 Academia Rd., Sec.2, Nankang Dist., Taipei, 115, Taiwan.

Immunoassays based on sandwich immuno-complexes of capture and detection antibodies simultaneously binding to the target analytes have been powerful technologies in molecular analyses. Recent developments in single molecule detection technologies enable the detection limit of the sandwich immunoassays approaching femtomolar (10 M), driving the needs of developing sensitive and specific antibodies for ever-increasingly broad applications in detecting and quantifying biomarkers. The key components underlying the sandwich immunoassays are antibody-based affinity reagents, for which the conventional sources are mono- or poly-clonal antibodies from immunized animals. The downsides of the animal-based antibodies as affinity reagents arise from the requirement of months of development timespan and limited choices of antibody candidates due to immunodominance of humoral immune responses in animals. Hence, developing animal antibodies capable of distinguishing highly related antigens could be challenging. To overcome the limitation imposed by the animal immune systems, we developed an in vitro methodology based on phage-displayed synthetic antibody libraries for diverse antibodies as affinity reagents against closely related influenza virus nucleoprotein (NP) subtypes, aiming to differentiating avian influenza virus (H5N1) from seasonal influenza viruses (H1N1 and H3N2), for which the NPs are closely related by 90-94% in terms of pairwise amino acid sequence identity. We applied the methodology to attain, within four weeks, a panel of IgGs with distinguishable specificities against a group of representative NPs with pairwise amino acid sequence identities up to more than 90%, and the antibodies derived from the antibody libraries without further affinity refinement had comparable affinity of mouse antibodies to the NPs with the detection limit less than 1 nM of viral NP from lysed virus with sandwich ELISA. The panel of IgGs were capable of rapidly distinguishing infections due to virulent avian influenza virus from infections of seasonal flu, in responding to a probable emergency scenario where avian influenza virus would be transmissible among humans overlapping with the seasonal influenza infections. The results indicate that the in vitro antibody development methodology enables developing diagnostic antibodies that would not otherwise be available from animal-based antibody technologies.
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http://dx.doi.org/10.1038/s41598-020-70135-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7414213PMC
August 2020

Anserine Reverses Exercise-Induced Oxidative Stress and Preserves Cellular Homeostasis in Healthy Men.

Nutrients 2020 Apr 19;12(4). Epub 2020 Apr 19.

Laboratory of Exercise Biochemistry, University of Taipei, No.101, Sec. 2, Zhongcheng Road., Shilin District, Taipei City 11153, Taiwan.

The study tested whether anserine (beta-alanyl-3-methyl-l-histidine), the active ingredient of chicken essence affects exercise-induced oxidative stress, cell integrity, and haematology biomarkers. In a randomized placebo-controlled repeated-measures design, ten healthy men ingested anserine in either a low dose (ANS-LD) 15 mg.kg.bw, high dose (ANS-HD) 30 mg.kg.bw, or placebo (PLA), following an exercise challenge (time to exhaustion), on three separate occasions. Anserine supplementation increased superoxide dismutase (SOD) by 50% ( < 0.001, effect size d = 0.8 for both ANS-LD and ANS-HD), and preserved catalase (CAT) activity suggesting an improved antioxidant activity. However, both ANS-LD and ANS-HD elevated glutathione disulfide (GSSG), (both < 0.001, main treatment effect), and consequently lowered the glutathione to glutathione disulfide (GSH/GSSG) ratio compared with PLA ( < 0.01, main treatment effect), without significant effects on thiobarbituric acid active reactive substances (TBARS). Exercise-induced cell damage biomarkers of glutamic-oxaloacetic transaminase (GOT) and myoglobin were unaffected by anserine. There were slight but significant elevations in glutamate pyruvate transaminase (GPT) and creatine kinase isoenzyme (CKMB), especially in ANS-HD ( < 0.05) compared with ANS-LD or PLA. Haematological biomarkers were largely unaffected by anserine, its dose, and without interaction with post exercise time-course. However, compared with ANS-LD and PLA, ANS-HD increased the mean cell volume (MCV), and decreased the mean corpuscular haemoglobin concentration (MCHC) ( < 0.001). Anserine preserves cellular homoeostasis through enhanced antioxidant activity and protects cell integrity in healthy men, which is important for chronic disease prevention. However, anserine temporal elevated exercise-induced cell-damage, together with enhanced antioxidant activity and haematological responses suggest an augmented exercise-induced adaptative response and recovery.
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http://dx.doi.org/10.3390/nu12041146DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7231017PMC
April 2020

Intensive measures of luminescence in GaN/InGaN heterostructures.

PLoS One 2019 24;14(9):e0222928. Epub 2019 Sep 24.

Graduate Institute of Electro-optical Engineering and Department of Electronic Engineering, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan, Republic of China.

The intensive measures of luminescence in a GaN/InGaN multiple quantum well system are used to examine the thermodynamics and phenomenological structure. The radiative /nonradiative transitions along with absorbed or emitted phonons that occur between the different quantum states of the electrons and holes associated with these processes make the quantum efficiency of a semiconductor nanosystem in an equilibrium state an extensive property. It has long been recognized that tuning of the indium (In) composition in InGaN interlayers gives the potential to obtain a spectrum in the near-infrared to near-ultraviolet spectral range. The thermodynamic intensive properties, including the Debye temperature, carrier temperature, and junction temperature, are the most appropriate metrics to describe the optical-related interactions inherent in a given heterostructure and so can be used as the state variables for understanding the quantum exchange behaviors. The energetic features of the quantum processes are characterized based on analysis of the intensive parameters as determined by means of electroluminescence (EL) and photoluminescence (PL) spectroscopy and current-voltage measurement and then correlated with the designed InGaN/GaN microstructures. According to the McCumber-Sturge theory, the EL and PL Debye temperatures obtained experimentally signal the strength of the electron-phonon and photon-phonon interaction, respectively, while the EL and PL carrier/junction temperatures correspond to the carrier localization. Higher EL Debye temperatures and lower EL carrier/junction temperatures reflect significantly higher luminescence quantum yields, indicative of electron-phonon coupling in the transfer of thermal energy between the confined electrons and the enhancement by excited phonons of heat-assisted emissions. On the other hand, the observation of low luminescence efficiency, corresponding to the lower PL Debye temperatures and higher PL carrier/junction temperatures, is attributed to photon-phonon coupling. These findings are in good accordance to the dependence of the EL and PL quantum efficiency on the In-content of the InGaN/GaN barriers, suggesting that the characteristic Debye and carrier/junction temperatures are intensive parameters useful for assessing the optical properties of a nano-engineered semiconductor heterostructure.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0222928PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6759175PMC
April 2020

A randomized, open-label pharmacokinetic trial of tacrolimus extended-release dosing in obese de novo kidney transplant recipients.

Clin Transplant 2019 08 1;33(8):e13640. Epub 2019 Jul 1.

Department of Surgery, Division of Transplantation, University of Illinois at Chicago, Chicago, Illinois.

Purpose: Tacrolimus extended-release (TAC-ER; Astagraf XL ) is utilized in many immunosuppressive regimens post-renal transplantation. Current dosing recommendation for the TAC-ER in renal transplant is 0.15-0.2 mg/kg/day administered once daily. The purpose of this study was to determine the best method of dosing TAC-ER in obese renal transplant recipients.

Methods: De novo obese kidney transplant recipients were randomized to receive TAC-ER 0.15 mg/kg/day based on either adjusted body weight (aBW) or ideal body weight (IBW). Post-transplant patients underwent three pharmacokinetic assessments over 14 days. The primary endpoint was the difference in TAC-ER exposure (AUC0-24) in obese patients dosed using aBW compared with IBW.

Results: A total of 20 obese renal transplant recipients were randomized to participate in the study (10 aBW and 10 IBW). Results of the primary outcome (AUC0-24) on Study Day 1, 7, and 14 were not statistically different between the two groups. There was no difference in the number of days to therapeutic trough concentration between the two dosing weights (aBW = 5.1, IBW = 4.9, days; P = 0.90).

Conclusion: In a population of obese renal transplant recipients, comparable trough concentrations and overall exposure in both groups indicate that IBW may be preferred, as less initial drug was needed to attain adequate exposure.
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http://dx.doi.org/10.1111/ctr.13640DOI Listing
August 2019

High throughput discovery of influenza virus neutralizing antibodies from phage-displayed synthetic antibody libraries.

Sci Rep 2017 10 31;7(1):14455. Epub 2017 Oct 31.

Genomics Research Center, Academia Sinica, 115, Taipei, Taiwan.

Pandemic and epidemic outbreaks of influenza A virus (IAV) infection pose severe challenges to human society. Passive immunotherapy with recombinant neutralizing antibodies can potentially mitigate the threats of IAV infection. With a high throughput neutralizing antibody discovery platform, we produced artificial anti-hemagglutinin (HA) IAV-neutralizing IgGs from phage-displayed synthetic scFv libraries without necessitating prior memory of antibody-antigen interactions or relying on affinity maturation essential for in vivo immune systems to generate highly specific neutralizing antibodies. At least two thirds of the epitope groups of the artificial anti-HA antibodies resemble those of natural protective anti-HA antibodies, providing alternatives to neutralizing antibodies from natural antibody repertoires. With continuing advancement in designing and constructing synthetic scFv libraries, this technological platform is useful in mitigating not only the threats of IAV pandemics but also those from other newly emerging viral infections.
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http://dx.doi.org/10.1038/s41598-017-14823-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5663709PMC
October 2017

Graphene/h-BN Heterostructures for Vertical Architecture of RRAM Design.

Sci Rep 2017 08 29;7(1):9679. Epub 2017 Aug 29.

Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan.

The development of RRAM is one of the mainstreams for next generation non-volatile memories to replace the conventional charge-based flash memory. More importantly, the simpler structure of RRAM makes it feasible to be integrated into a passive crossbar array for high-density memory applications. By stacking up the crossbar arrays, the ultra-high density of 3D horizontal RRAM (3D-HRAM) can be realized. However, 3D-HRAM requires critical lithography and other process for every stacked layer, and this fabrication cost overhead increases linearly with the number of stacks. Here, it is demonstrated that the 2D material-based vertical RRAM structure composed of graphene plane electrode/multilayer h-BN insulating dielectric stacked layers, AlO/TiO resistive switching layer and ITO pillar electrode exhibits reliable device performance including forming-free, low power consumption (P = ~2 μW and P = ~0.2 μW), and large memory window (>300). The scanning transmission electron microscopy indicates that the thickness of multilayer h-BN is around 2 nm. Due to the ultrathin-insulating dielectric and naturally high thermal conductivity characteristics of h-BN, the vertical structure combining the graphene plane electrode with multilayer h-BN insulating dielectric can pave the way toward a new area of ultra high-density memory integration in the future.
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http://dx.doi.org/10.1038/s41598-017-08939-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5575158PMC
August 2017

Dual-functional Memory and Threshold Resistive Switching Based on the Push-Pull Mechanism of Oxygen Ions.

Sci Rep 2016 Apr 7;6:23945. Epub 2016 Apr 7.

Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan.

The combination of nonvolatile memory switching and volatile threshold switching functions of transition metal oxides in crossbar memory arrays is of great potential for replacing charge-based flash memory in very-large-scale integration. Here, we show that the resistive switching material structure, (amorphous TiOx)/(Ag nanoparticles)/(polycrystalline TiOx), fabricated on the textured-FTO substrate with ITO as the top electrode exhibits both the memory switching and threshold switching functions. When the device is used for resistive switching, it is forming-free for resistive memory applications with low operation voltage (<± 1 V) and self-compliance to current up to 50 μA. When it is used for threshold switching, the low threshold current is beneficial for improving the device selectivity. The variation of oxygen distribution measured by energy dispersive X-ray spectroscopy and scanning transmission electron microscopy indicates the formation or rupture of conducting filaments in the device at different resistance states. It is therefore suggested that the push and pull actions of oxygen ions in the amorphous TiOx and polycrystalline TiOx films during the voltage sweep account for the memory switching and threshold switching properties in the device.
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http://dx.doi.org/10.1038/srep23945DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4823777PMC
April 2016

Iridovirus CARD Protein Inhibits Apoptosis through Intrinsic and Extrinsic Pathways.

PLoS One 2015 5;10(6):e0129071. Epub 2015 Jun 5.

Molecular Genetics Laboratory, Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan; Institute of Fisheries Science, National Taiwan University, Taipei, Taiwan; Institute of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan.

Grouper iridovirus (GIV) belongs to the genus Ranavirus of the family Iridoviridae; the genomes of such viruses contain an anti-apoptotic caspase recruitment domain (CARD) gene. The GIV-CARD gene encodes a protein of 91 amino acids with a molecular mass of 10,505 Daltons, and shows high similarity to other viral CARD genes and human ICEBERG. In this study, we used Northern blot to demonstrate that GIV-CARD transcription begins at 4 h post-infection; furthermore, we report that its transcription is completely inhibited by cycloheximide but not by aphidicolin, indicating that GIV-CARD is an early gene. GIV-CARD-EGFP and GIV-CARD-FLAG recombinant proteins were observed to translocate from the cytoplasm into the nucleus, but no obvious nuclear localization sequence was observed within GIV-CARD. RNA interference-mediated knockdown of GIV-CARD in GK cells infected with GIV inhibited expression of GIV-CARD and five other viral genes during the early stages of infection, and also reduced GIV infection ability. Immunostaining was performed to show that apoptosis was effectively inhibited in cells expressing GIV-CARD. HeLa cells irradiated with UV or treated with anti-Fas antibody will undergo apoptosis through the intrinsic and extrinsic pathways, respectively. However, over-expression of recombinant GIV-CARD protein in HeLa cells inhibited apoptosis induced by mitochondrial and death receptor signaling. Finally, we report that expression of GIV-CARD in HeLa cells significantly reduced the activities of caspase-8 and -9 following apoptosis triggered by anti-Fas antibody. Taken together, these results demonstrate that GIV-CARD inhibits apoptosis through both intrinsic and extrinsic pathways.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0129071PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4457926PMC
March 2016

Recognition of Linear B-Cell Epitope of Betanodavirus Coat Protein by RG-M18 Neutralizing mAB Inhibits Giant Grouper Nervous Necrosis Virus (GGNNV) Infection.

PLoS One 2015 4;10(5):e0126121. Epub 2015 May 4.

Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan; Institute of Fisheries Science, National Taiwan University, Taipei, Taiwan.

Betanodavirus is a causative agent of viral nervous necrosis syndrome in many important aquaculture marine fish larvae, resulting in high global mortality. The coat protein of Betanodavirus is the sole structural protein, and it can assemble the virion particle by itself. In this study, we used a high-titer neutralizing mAB, RG-M18, to identify the linear B-cell epitope on the viral coat protein. By mapping a series of recombinant proteins generated using the E. coli PET expression system, we demonstrated that the linear epitope recognized by RG-M18 is located at the C-terminus of the coat protein, between amino acid residues 195 and 338. To define the minimal epitope region, a set of overlapping peptides were synthesized and evaluated for RG-M18 binding. Such analysis identified the 195VNVSVLCR202 motif as the minimal epitope. Comparative analysis of Alanine scanning mutagenesis with dot-blotting and ELISA revealed that Valine197, Valine199, and Cysteine201 are critical for antibody binding. Substitution of Leucine200 in the RGNNV, BFNNV, and TPNNV genotypes with Methionine200 (thereby simulating the SJNNV genotype) did not affect binding affinity, implying that RG-M18 can recognize all genotypes of Betanodaviruses. In competition experiments, synthetic multiple antigen peptides of this epitope dramatically suppressed giant grouper nervous necrosis virus (GGNNV) propagation in grouper brain cells. The data provide new insights into the protective mechanism of this neutralizing mAB, with broader implications for Betanodavirus vaccinology and antiviral peptide drug development.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0126121PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4418827PMC
April 2016

Effects of signal sequence on phage-displayed disulfide-stabilized single chain antibody variable fragment (sc-dsFv) libraries.

Biochem Biophys Res Commun 2011 Jul 28;411(2):348-53. Epub 2011 Jun 28.

Genomics Research Center, Academia Sinica, Taipei 115, Taiwan, ROC.

Phage-displayed single chain variable fragment (scFv) libraries are powerful tools in antibody engineering. Disulfide-stabilized scFv (sc-dsFv) with an interface disulfide bond is structure-wise more stable than the corresponding scFv. A set of recently discovered signal sequences replacing the wild type (pelB) signal peptidase cleavage site in the c-region has been shown to be effective in rescuing the expression of sc-dsFv libraries on the phage surface. However, the effects of the other regions of the signal sequence on the expression of the sc-dsFv libraries and on the formation of the interface disulfide bond in the phage-displayed sc-dsFv have not been clear. In this work, selected novel signal sequence variants in the h-region were shown to be equally effective in promoting sc-dsFv library expression on the phage surface; the expression level and complexity of the sc-dsFv libraries were comparable to the corresponding scFv libraries produced with the wild-type (pelB) signal sequence. The interface disulfide bond in the phage-displayed sc-dsFv was proven to form to a large extent in the library variant ensemble generated with signal sequence variants in both the h-region and the c-region. The sc-dsFv engineering platform established in this work can be applied to many of the known scFv molecules which are in need of a more stable version for the applications under harsh conditions or for longer shelf-life.
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http://dx.doi.org/10.1016/j.bbrc.2011.06.146DOI Listing
July 2011

[Loneliness: a concept analysis].

Hu Li Za Zhi 2010 Oct;57(5):96-101

School of Nursing, National Defense Medical Center, No. 161 Minchuan E. Road, Neihu, Taipei, Taiwan, ROC.

Loneliness is a kind of mood that most people have experienced at one time or another. Individual experiences with loneliness as joyful or painful saturation are highly personal and can be defined only in such a context. Loneliness has differing effects on the long-term health of individuals. Although loneliness impacts greatly on individual health, there is little in the literature related to concept analyses of loneliness. The purpose of this article was to use Walker and Avant's (2005) concept analysis methodology to review conceptual definitions of loneliness, characteristics, antecedents and consequences; construct examples and establish empirical measurements. Results indicate that defining attributes of loneliness included an individual's subjective mood, descriptions of aloneness, depression, desolation or empty feelings, and the perception of the spirit isolated from others. It is hoped that nursing staffs may better understand loneliness through this article, provide an assessment of client loneliness as early as possible, and enhance client health condition.
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October 2010

The genetic background difference between diabetic patients with and without nephropathy in a Taiwanese population by linkage disequilibrium mapping using 382 autosomal STR markers.

Genet Test Mol Biomarkers 2010 Jun;14(3):433-8

Division of Endocrinology and Metabolism, Cardinal Tien Hospital, Taipei, Taiwan.

The genome-wide linkage disequilibrium screening for loci associated with genetic difference between diabetic patients with and without nephropathy was conducted employing 382 autosomal STR markers involving 185 diabetic subjects. Among them, 25 STR markers showed evidence for nominal association with a difference between the two diabetic groups. To investigate the reliability of the association result, the E2a/Pbx1-activated gene in pre-B cells 1 (EB-1) gene was selected from 267 diabetic subjects for single-nucleotide polymorphism genotyping because its genomic region encircles the significant STR marker D12S346. It is clear that some single-nucleotide polymorphisms and haplotypes of the EB-1 gene are associated with genetic difference between diabetic patients with and without nephropathy. This study further indicates that diabetic nephropathy is indeed a genetically heterogeneous group of diseases with similar clinical phenotypes.
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http://dx.doi.org/10.1089/gtmb.2009.0179DOI Listing
June 2010

Signal sequence as a determinant in expressing disulfide-stabilized single chain antibody variable fragments (sc-dsFv) against human VEGF.

Mol Biosyst 2010 Jul 27;6(7):1307-15. Epub 2010 Apr 27.

Genomics Research Center, Academia Sinica, 128 Academia Road, Section 2 Taipei, 115 Taiwan, ROC.

Phage-displayed single chain variable fragment (scFv) libraries have been powerful tools in antibody engineering. But the scFv structures are frequently unstable due to the dissociation of the dimeric interface between the two variable domains. One solution is the sc-dsFv construct, where the single chain variable domain fragment is stabilized with an additional interface disulfide bond, leading to stable and homogeneous dimeric interface for the sc-dsFv structure. However, the phagemid system that is capable of effective expression for both sc-dsFv-pIII fusion proteins on phage surface and secreted non-fusion sc-dsFv in bacterial culture medium has not been demonstrated. In this work, a biological combinatorial approach was applied to optimize the signal sequence N-terminal to the sc-dsFv-pIII fusion protein encoded in a phagemid. The optimized sc-dsFv phage display systems were compatible with both the phage-based directed evolution procedure and the high throughput screening of the soluble sc-dsFv. The utility of the phagemid systems was demonstrated in generating anti-VEGF sc-dsFv with VEGF-binding affinity one order of magnitude higher than the corresponding scFv, due only to the interface disulfide bond in the sc-dsFv. Moreover, the protein stability of the sc-dsFv construct was unmatched by the corresponding scFv. These advantages of the sc-dsFv were gained through the interface disulfide bond of the sc-dsFv and the novel signal sequence in the phagemid.
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http://dx.doi.org/10.1039/b921106cDOI Listing
July 2010

Engineering anti-vascular endothelial growth factor single chain disulfide-stabilized antibody variable fragments (sc-dsFv) with phage-displayed sc-dsFv libraries.

J Biol Chem 2010 Mar 12;285(11):7880-91. Epub 2010 Jan 12.

Genomics Research Center, Academia Sinica, Taipei 115, Taiwan.

Phage display of antibody fragments from natural or synthetic antibody libraries with the single chain constructs combining the variable fragments (scFv) has been one of the most prominent technologies in antibody engineering. However, the nature of the artificial single chain constructs results in unstable proteins expressed on the phage surface or as soluble proteins secreted in the bacterial culture medium. The stability of the variable domain structures can be enhanced with interdomain disulfide bond, but the single chain disulfide-stabilized constructs (sc-dsFv) have yet to be established as a feasible format for bacterial phage display due to diminishing expression levels on the phage surface in known phage display systems. In this work, biological combinatorial searches were used to establish that the c-region of the signal sequence is critically responsible for effective expression and functional folding of the sc-dsFv on the phage surface. The optimum signal sequences increase the expression of functional sc-dsFv by 2 orders of magnitude compared with wild-type signal sequences, enabling the construction of phage-displayed synthetic antivascular endothelial growth factor sc-dsFv libraries. Comparison of the scFv and sc-dsFv variants selected from the phage-displayed libraries for vascular endothelial growth factor binding revealed the sequence preference differences resulting from the interdomain disulfide bond. These results underlie a new phage display format for antibody fragments with all the benefits from the scFv format but without the downside due to the instability of the dimeric interface in scFv.
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http://dx.doi.org/10.1074/jbc.M109.061457DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2832938PMC
March 2010

Dual-operation-mode liquid crystal lens.

Opt Express 2009 Nov;17(23):20860-5

Graduate Institute of Photonics, National Changhua University of Education, Changhua, Taiwan 500, Republic of China.

We demonstrate a dual-operation-mode liquid crystal (LC) lens, which is fabricated with the silica nanoparticle-doped (SND) hybrid-aligned nematic (HAN) LC cell. With AC voltage, the cell behaves as a conventional LC lens. The response time of the SND HAN LC lens is faster than that of the conventional LC lens, which is fabricated using the pristine HAN LC cell. This is because that the doped silica nanoparticles may decrease the dielectric relaxation time constant of the cell. The addition of the silica nanoparticles also increases the viscosity of the LC host, suppresses the backflow motion of the LCs and then decreases the response time of the SND LC lens. With DC voltage, the electrophoretic motion of the doped silica nanoparticles and the agglomerate silica networks on the substrate surface cause the SND HAN LC cell to function as a bistable LC lens.
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http://dx.doi.org/10.1364/OE.17.020860DOI Listing
November 2009

Gene-gene interactions among genetic variants from obesity candidate genes for nonobese and obese populations in type 2 diabetes.

Genet Test Mol Biomarkers 2009 Aug;13(4):485-93

Bioinformatics Division, Vita Genomics, Inc., Taipei County, Taiwan.

Recent studies indicate that obesity may play a key role in modulating genetic predispositions to type 2 diabetes (T2D). This study examines the main effects of both single-locus and multilocus interactions among genetic variants in Taiwanese obese and nonobese individuals to test the hypothesis that obesity-related genes may contribute to the etiology of T2D independently and/or through such complex interactions. We genotyped 11 single nucleotide polymorphisms for 10 obesity candidate genes including adrenergic beta-2-receptor surface, adrenergic beta-3-receptor surface, angiotensinogen, fat mass and obesity associated gene, guanine nucleotide binding protein beta polypeptide 3 (GNB3), interleukin 6 receptor, proprotein convertase subtilisin/kexin type 1 (PCSK1), uncoupling protein 1, uncoupling protein 2, and uncoupling protein 3. There were 389 patients diagnosed with T2D and 186 age- and sex-matched controls. Single-locus analyses showed significant main effects of the GNB3 and PCSK1 genes on the risk of T2D among the nonobese group (p = 0.002 and 0.047, respectively). Further, interactions involving GNB3 and PCSK1 were suggested among the nonobese population using the generalized multifactor dimensionality reduction method (p = 0.001). In addition, interactions among angiotensinogen, fat mass and obesity associated gene, GNB3, and uncoupling protein 3 genes were found in a significant four-locus generalized multifactor dimensionality reduction model among the obese population (p = 0.001). The results suggest that the single nucleotide polymorphisms from the obesity candidate genes may contribute to the risk of T2D independently and/or in an interactive manner according to the presence or absence of obesity.
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http://dx.doi.org/10.1089/gtmb.2008.0145DOI Listing
August 2009

Athletic performance and serial weight changes during 12- and 24-hour ultra-marathons.

Clin J Sport Med 2008 Mar;18(2):155-8

Section of Emergency Medicine, National Yang-Ming University, Taipei, Taiwan.

Objective: The principal objective of this study was to evaluate serial weight changes in athletes during 12- and 24-hour ultra-marathons and to correlate these changes with athletic performance, namely the distance covered.

Design: This was a prospective study.

Setting: The 2003 Soochow University international ultra-marathon.

Participants: Fifty-two race participants.

Interventions: 12- or 24-hour ultra-marathon.

Main Outcome Measurements: Body weight changes were measured before, at 4-hour intervals during, and immediately after the 12- and 24-hour races.

Results: Significant overall decreases in body weight were apparent at the conclusion of both races. The mean relative body weight change after the 12-hour race was -2.89 +/- 1.56%, ranging from 0 to 6.5%. The mean relative body weight change after the 24-hour race was -5.05 +/- 2.28%, ranging from -0.77% to -11.40%. Of runners in the 24-hour race, 26% lost greater than 7% of baseline body weight during the race. During both the 12- and 24-hour races, the greatest weight change (decrease) occurred during the first 4 hours. Weight remained relatively stable after 8 hours, although a further decrease was apparent between 16 and 20 hours in the 24-hour participants. Weight change had no bearing on performance in the 12-hour race, whereas weight loss was positively associated with performance in the 24-hour race.

Conclusions: Our findings demonstrate that the majority of weight decrease/dehydration in both the 12- and 24-hour races occurred during the first 8 hours. Hence, to maintain body weight, fluid intake should be optimized in the first 8 hours for both 12- and 24-hour runners and in 16 to 20 hours for 24-hour marathon runners.
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http://dx.doi.org/10.1097/JSM.0b013e31815cdd37DOI Listing
March 2008

Factor Xa active site substrate specificity with substrate phage display and computational molecular modeling.

J Biol Chem 2008 May 22;283(18):12343-53. Epub 2008 Feb 22.

Genomics Research Center, Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan 115.

Structural origin of substrate-enzyme recognition remains incompletely understood. In the model enzyme system of serine protease, canonical anti-parallel beta-structure substrate-enzyme complex is the predominant hypothesis for the substrate-enzyme interaction at the atomic level. We used factor Xa (fXa), a key serine protease of the coagulation system, as a model enzyme to test the canonical conformation hypothesis. More than 160 fXa-cleavable substrate phage variants were experimentally selected from three designed substrate phage display libraries. These substrate phage variants were sequenced and their specificities to the model enzyme were quantified with quantitative enzyme-linked immunosorbent assay for substrate phage-enzyme reaction kinetics. At least three substrate-enzyme recognition modes emerged from the experimental data as necessary to account for the sequence-dependent specificity of the model enzyme. Computational molecular models were constructed, with both energetics and pharmacophore criteria, for the substrate-enzyme complexes of several of the representative substrate peptide sequences. In contrast to the canonical conformation hypothesis, the binding modes of the substrates to the model enzyme varied according to the substrate peptide sequence, indicating that an ensemble of binding modes underlay the observed specificity of the model serine protease.
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http://dx.doi.org/10.1074/jbc.M708843200DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2430999PMC
May 2008

Iridovirus Bcl-2 protein inhibits apoptosis in the early stage of viral infection.

Apoptosis 2008 Jan;13(1):165-76

Molecular Genetics Laboratory, Rm. 336, Institute of Cellular and Organismic Biology, Academia Sinica, 128 Academia Road Section 2, Nankang, Taipei, Taiwan, ROC.

The grouper iridovirus (GIV) belongs to the family Iridoviridae, whose genome contains an antiapoptotic B-cell lymphoma (Bcl)-2-like gene. This study was carried-out to understand whether GIV blocks apoptosis in its host. UV-irradiated grouper kidney (GK) cells underwent apoptosis. However, a DNA fragmentation assay of UV-exposed GK cells after GIV infection revealed an inhibition of apoptosis. The UV- or heat-inactivated GIV failed to inhibit apoptosis, implying that a gene or protein of the viral particle might contribute to an apoptosis inhibitory function. The DNA ladder assay for GIV-infected GK cells after UV irradiation confirmed that apoptosis inhibition was an early process which occurred as early as 5 min post-infection. A GIV-Bcl sequence comparison showed distant sequence similarities to that of human and four viruses; however, all possessed the putative Bcl-2 homology (BH) domains of BH1, BH2, BH3, and BH4, as well as a transmembrane domain. Northern blot hybridization showed that GIV-Bcl transcription began at 2 h post-infection, and the mRNA level significantly increased in the presence of cycloheximide or aphidicolin, indicating that this GIV-Bcl is an immediate-early gene. This was consistent with the Western blot results, which also revealed that the virion carries the Bcl protein. We observed the localization of GIV-Bcl on the mitochondrial membrane and other defined intracellular areas. By immunostaining, it was proven that GIV-Bcl-expressing cells effectively inhibited apoptosis. Taken together, these results demonstrate that GIV inhibits the promotion of apoptosis by GK cells, which is mediated by the immediate early expressed viral Bcl gene.
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http://dx.doi.org/10.1007/s10495-007-0152-yDOI Listing
January 2008

The role of pannexin 1 hemichannels in ATP release and cell-cell communication in mouse taste buds.

Proc Natl Acad Sci U S A 2007 Apr 26;104(15):6436-41. Epub 2007 Mar 26.

Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA.

ATP has been shown to be a taste bud afferent transmitter, but the cells responsible for, and the mechanism of, its release have not been identified. Using CHO cells expressing high-affinity neurotransmitter receptors as biosensors, we show that gustatory stimuli cause receptor cells to secrete ATP through pannexin 1 hemichannels in mouse taste buds. ATP further stimulates other taste cells to release a second transmitter, serotonin. These results provide a mechanism to link intracellular Ca(2+) release during taste transduction to secretion of afferent transmitter, ATP, from receptor cells. They also indicate a route for cell-cell communication and signal processing within the taste bud.
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http://dx.doi.org/10.1073/pnas.0611280104DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1851090PMC
April 2007

A possible link between exercise-training adaptation and dehydroepiandrosterone sulfate- an oldest-old female study.

Int J Med Sci 2006 Sep 10;3(4):141-7. Epub 2006 Sep 10.

Department of Kinesiology, SooChow University, Taipei, Taiwan.

The purpose of this study was to determine the association between the level of salivary dehydroepiandrosterone sulfate (DHEA-S) and the magnitude of adaptation to exercise training in insulin sensitivity for aged females. A group of 16 females, aged 80-93 years old, was divided into 2 groups according to their baseline DHEA-S levels: Lower Halves (N = 8) and Upper Halves (N = 8), and participated in a 4-month exercise intervention trial. Insulin response with an oral glucose tolerance test (OGTT), cholesterol, blood pressure (BP), motor performance, and DHEA-S were determined at baseline and 4 months after the training program. Glucose tolerance and body mass index (BMI) remained unchanged with training for both groups. Insulin, fasted cholesterol, diastolic blood pressure, reaction time, and locomotive function were significantly lowered by training only in the Upper Halves group. Changes in the area under curve of insulin (IAUC) were negatively correlated with the baseline DHEA-S level (R= - 0.60, P < 0.05). The current study provides the first evidence that oldest-old subjects with low DHEA-S level appear to be poor responders to exercise-training adaptations.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1570619PMC
http://dx.doi.org/10.7150/ijms.3.141DOI Listing
September 2006

Glycogen overload by postexercise insulin administration abolished the exercise-induced increase in GLUT4 protein.

J Biomed Sci 2005 Dec 1;12(6):991-8. Epub 2005 Dec 1.

Center for General Education, National Chi-Nan University, Nantou, Taiwan, ROC.

To elucidate the role of muscle glycogen storage on regulation of GLUT4 protein expression and whole-body glucose tolerance, muscle glycogen level was manipulated by exercise and insulin administration. Sixty Sprague-Dawley rats were evenly separated into three groups: control (CON), immediately after exercise (EX0), and 16 h after exercise (EX16). Rats from each group were further divided into two groups: saline- and insulin-injected. The 2-day exercise protocol consisted of 2 bouts of 3-h swimming with 45-min rest for each day, which effectively depleted glycogen in both red gastrocnemius (RG) and plantaris muscles. EX0 rats were sacrificed immediately after the last bout of exercise on second day. CON and EX16 rats were intubated with 1 g/kg glucose solution following exercise and recovery for 16 h before muscle tissue collection. Insulin (0.5 microU/kg) or saline was injected daily at the time when glucose was intubated. Insulin injection elevated muscle glycogen levels substantially in both muscles above saline-injected group at CON and EX16. With previous day insulin injection, EX0 preserved greater amount of postexercise glycogen above their saline-injected control. In the saline-injected rats, EX16 significantly increased GLUT4 protein level above CON, concurrent with muscle glycogen supercompensation. Insulin injection for EX16 rats significantly enhanced muscle glycogen level above their saline-injected control, but the increases in muscle GLUT4 protein and whole-body glucose tolerance were attenuated. In conclusion, the new finding of the study was that glycogen overload by postexercise insulin administration significantly abolished the exercise-induced increases in GLUT4 protein and glucose tolerance.
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http://dx.doi.org/10.1007/s11373-005-9019-9DOI Listing
December 2005

Mouse taste buds release serotonin in response to taste stimuli.

Chem Senses 2005 Jan;30 Suppl 1:i39-40

University of Miami School of Medicine, Miami, FL 33136, USA.

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http://dx.doi.org/10.1093/chemse/bjh102DOI Listing
January 2005

Mouse taste buds use serotonin as a neurotransmitter.

J Neurosci 2005 Jan;25(4):843-7

Department of Physiology and Biophysics, University of Miami School of Medicine, Miami, Florida 33136, USA.

Synapses between gustatory receptor cells and primary sensory afferent fibers transmit the output signal from taste buds to the CNS. Several transmitter candidates have been proposed for these synapses, including serotonin (5-HT), glutamate, acetylcholine, ATP, peptides, and others, but, to date, none has been unambiguously identified. We used Chinese hamster ovary cells stably expressing 5-HT2C receptors as biodetectors to monitor 5-HT release from taste buds. When taste buds were depolarized with KCl or stimulated with bitter, sweet, or sour (acid) tastants, serotonin was released. KCl- and acid-induced 5-HT release, but not release attributable to sweet or bitter stimulation, required Ca2+ influx. In contrast, 5-HT release evoked by sweet and bitter stimulation seemed to be triggered by intracellular Ca2+ release. These experiments strongly implicate serotonin as a taste bud neurotransmitter and reveal unexpected transmitter release mechanisms.
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http://dx.doi.org/10.1523/JNEUROSCI.4446-04.2005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6725637PMC
January 2005

Effects of 24 h ultra-marathon on biochemical and hematological parameters.

World J Gastroenterol 2004 Sep;10(18):2711-4

Department of Physical Education, Chinese Culture University, Taipei 111, Taiwan, China.

Aim: To analyze detailed changes in hematology and biochemistry tests parameters before and after a long-distance race in ultramarathon runners.

Methods: Blood samples of 11 participants were obtained for standard analysis before, immediately after, two days after and nine days after the 2002 International Ultra-marathon 24 h Race and the International Association of Ultrarunners (IAU) Asia 24 h Championship.

Results: Total bilirubin (BIL-T), direct bilirubin (BIL-D), alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) increased statistically significantly (P<0.05) the race. Significant declines (P<0.05) in red blood cell (RBC), hemoglobin (Hb) and hematocrit (Hct) were detected two days and nine days d after the race. 2 d after the race, total protein (TP), concentration of albumin and globulin decreased significantly. While BIL, BIL-D and ALP recovered to their original levels. High-density lipoprotein cholesterol (HDL-C) remained unchanged immediately after the race, but it was significantly decreased on the second and ninth days after the race.

Conclusion: Ultra-marathon running is associated with a wide range of significant changes in hematological parameters, several of which are injury related. To provide appropriate health care and intervention, the man who receives athletes on high frequent training program high intensity training programs must monitor their liver and gallbladder function.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4572198PMC
http://dx.doi.org/10.3748/wjg.v10.i18.2711DOI Listing
September 2004

Immunoelectron microscopic studies on protein gene product 9.5 and calcitonin gene-related peptide in vallate taste cells and related nerves in the guinea pig.

Microsc Res Tech 2003 Dec;62(5):383-95

Department of Anatomy, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.

On the basis of our previous report that protein gene product 9.5 (PGP 9.5)-immunoreactive nerve fibers and taste cells and calcitonin gene-related peptide (CGRP)-immunoreactive nerve fibers are found in guinea pig vallate papillae [Huang and Lu (1996b) Arch. Histol. Cytol. 59:433-441]. We speculated that PGP 9.5 might be a marker for taste receptor cells and that CGRP might play an important role in taste transmission. We, therefore, performed an immunohistochemical and ultrastructural analysis of taste cells and related nerves in guinea pig vallate papillae. In the connective tissue of the vallate papilla, the ultrastructural data revealed that the PGP 9.5-immunoreactive nerve fibers were both myelinated and unmyelinated. The CGRP-immunoreactive nerve fibers were unmyelinated and surrounded by the cytoplasm of Schwann cells as were the non-immunoreactive fibers. In the vallate taste buds, only type III cells, which make synaptic contacts with intragemmal nerves, were PGP 9.5-immunoreactive, while the nerve terminals making synaptic contact with the underlying type III cells were CGRP-immunoreactive. From these observations, we conclude that: (1) PGP 9.5 might be a useful specific marker for type III cells in guinea pig vallate taste buds; and (2) CGRP-containing nerve fibers might be primarily involved in the neural transmission of taste stimuli.
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http://dx.doi.org/10.1002/jemt.10396DOI Listing
December 2003