Publications by authors named "Li Chun Chen"

24 Publications

  • Page 1 of 1

Improvement of surgical complications using single-lumen endotracheal tube intubation and artificial carbon dioxide pneumothorax in esophagectomy: a meta-analysis.

J Cardiothorac Surg 2021 Apr 21;16(1):100. Epub 2021 Apr 21.

Department of Thoracic & Cardiovascular Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, 123 Ta-Pei Road, Niaosung Dist., Kaohsiung, Taiwan, Republic of China.

Background: Esophageal cancer has a poor prognosis. Surgery is the main treatment but involves a high risk of complications. Some surgical strategies have tried to eliminate complications. Our meta-analysis tried to find the benefits of single-lumen endotracheal tube intubation with carbon dioxide (CO) inflation.

Methods: A systematic search of studies on esophagectomy and CO inflation was conducted using PubMed, Medline, and Scopus. The odds ratio of post-operative pulmonary complications and anastomosis leakage were the primary outcomes. The standardized mean difference (SMD) in post-operative hospitalization duration was the secondary outcome.

Results: The meta-analysis included four case-control studies with a total of 1503 patients. The analysis showed a lower odds ratio of pulmonary complications in the single-lumen endotracheal tube intubation in the CO inflation group (odds ratio: 0.756 [95% confidence interval, CI: 0.518 to 1.103]) compared to that in the double-lumen endotracheal tube intubation group, but anastomosis leakage did not improve (odds ratio: 1.056 [95% CI: 0.769 to 1.45])). The SMD in hospitalization duration did not show significant improvement. (SMD: -0.141[95% CI: - 0.248 to - 0.034]).

Conclusions: Single-lumen endotracheal tube intubation with CO inflation improved pulmonary complications and shortened the hospitalization duration. However, no benefit in anastomosis leakage was observed.
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http://dx.doi.org/10.1186/s13019-021-01459-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8059030PMC
April 2021

Disease progression associated with low bone mass in axial spondyloarthropathy patients.

Arch Osteoporos 2021 04 8;16(1):65. Epub 2021 Apr 8.

Department of Radiology, Xiamen Hospital of Traditional Chinese Medicine, 1739 Xianyue Road, Huli, Xiamen, 361001, Fujian, China.

Through statistical analysis, we have found that inflammation and low femoral and lumbar spine BMD were strongly correlated with a high SIJ CT grade, and inflammation, low vitamin D levels, and a longer disease course within a certain time range influenced bone loss in axSpA.

Purpose: We investigated the relationship between bone mineral density (BMD), vitamin D, and computed tomography (CT)-based progression of disease grades of the sacroiliac joint (SIJ), and sought to identify parameters predicting low BMD in patients with axial spondyloarthropathy (axSpA).

Methods: We collected the ankylosis spondylitis disease activity score (ASDAS), the course of the disease, HLA-B27 status, and vitamin D and C-reactive protein (CRP) levels of 98 axSpA patients. Lumbar spine and femoral BMD were assessed by dual-energy X-ray (DXA), and SIJ grade was determined by CT.

Results: The axSpA patients (71 men, 27 women) with a mean age of 31.9 years (range 18-57 years) and body mass index 21.8 kg/m (range 15.6-30.6 kg/m), with disease duration 4.5 years (range 0.3-30 years) were included. A longer disease course, higher CRP level, and lower femoral and lumbar spine BMD were independently related to a higher CT grade. Older age, longer disease course, elevated CRP, and high SIJ CT grade were independently related to lower BMD (femur and/or lumbar spine L1-L4 T scores ≤ -1). Older age, elevated CRP, low vitamin D levels, and high CT grade were independently associated with low femur and lumbar spine BMD. However, a longer disease course was independently related to low femur BMD, but not low lumbar spine BMD.

Conclusions: Thus, inflammation and low femoral and lumbar spine BMD were strongly correlated with a high SIJ CT grade, and inflammation, low vitamin D levels, and a longer disease course within a certain time range influenced bone loss in axSpA.
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http://dx.doi.org/10.1007/s11657-021-00928-3DOI Listing
April 2021

[Reversal effect of peptide-modified chitosan tetramethylpyrazine nanoparticles on multidrug resistance in tumor cells].

Zhongguo Zhong Yao Za Zhi 2020 Nov;45(22):5487-5494

Dalian Medical University Dalian 116044, China.

To prepare peptide-modified chitosan tetramethylprazine nanoparticles(FGF-CS-TMP-NPS) and investigate its reversal effect on multidrug resistance in tumor cells. The pEGF-CS-TMP-NPs were prepared by ion crosslinking method, and their physicochemical properties were investigated. Western blot was used to detect the expression levels of epidermal growth factor receptor(EGFR)(MCF-7, MCF-7/ADR, K562 and K562/ADR) and drug-resistant related protein P-gp. MCF-7/ADR and K562/ADR were selected as cell models. The cytotoxicity of pEGF-CS-TMP-NPs, the multiple of cell resistance to adriamycin, the reversal resistance index of pEGF-CS-TMP-NPs to doxorubicin and the sensitization of pEGF-CS-TMP-NPs to doxorubicin were detected by MTT assay. After MCF-7/ADR and K562/ADR were treated with pEGF-CS-TMP-NPs, the expression changes of P-gp were detected by Western blot. The encapsulation efficiency and drug loading of pEGF-CS-TMP-NPs were 37.66%± 0.53% and 3.25%± 0.34% respectively in HPLC. The nanoparticles showed an average particle size of(150.50±9.3) nm, polymer dispersity index of(0.059±0.007) and Zeta potential of(19.30±2.02) mV as detected by laser particle size analyzer. The nanoparticles were spherical and well dispersed under transmission electron microscope. Western blot results showed that EGFR was positively expressed in MCF-7 and MCF-7/ADR cells, while negatively expressed in K562 and K562/ADR cells. P-gp was highly expressed in MCF-7/ADR and K562/ADR, while negatively expressed in MCF-7 and K562. pEGF-CS-TMP-NPs had a weak effect on MCF-7/ADR and K562/ADR. The adriamycin resistance of MCF-7/ADR cells was 108.36 times, and that of K562/ADR cells was more than 100 times. When IC_(85) of pEGF-CS-TMP-NPs was used as the administration concentration, the reversion index of MCF-7/ADR and K562/ADR cells was 3.68 and 1.87, respectively. pEGF-CS-TMP-NPs could enhance the sensitivity of adriamycin to MCF-7/ADR cells in a positive correlation with the concentration, and the sensitivity was significantly higher than that of K562/ADR cells. Western blot results showed that the expression level of P-gp in MCF-7/ADR cells decreased significantly after treatment with pEGF-CS-TMP-NPs, while the expression level of P-gp in K562/ADR cells did not change significantly. Experimental results show that pEGF-CS-TMP-NPs have an active targeting effect on MCF-7/ADR cells with high EGFR expression, and can effectively reverse the multidrug resistance of MCF-7/ADR cells. Active targeting effect is related to the peptides modification of nanoparticles, and the mechanism of reversing tumor MDR may be achieved by down-regulating the expression level of P-gp.
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http://dx.doi.org/10.19540/j.cnki.cjcmm.20200820.301DOI Listing
November 2020

Functional coix seed protein hydrolysates as a novel agent with potential hepatoprotective effect.

Food Funct 2020 Nov;11(11):9495-9502

School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310035, China.

The aim of this study is to explore the hepatoprotective potential of coix seed protein hydrolysates (CPP) against alcohol-induced liver injury, and investigate the underlying mechanisms. The hepatoprotective activity of CPP at 0, 10, 30, 50 mg per kg BW was demonstrated in vivo by using ICR male mice fed with 40% v/v alcohol (5 ml per kg body weight) daily to induce alcoholic liver injury. CPP could significantly improve the alcohol metabolism in liver as evidenced by the enhanced activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The overexpression of serum tumor necrosis factor-α (TNF-α) and interleukin-β (IL-β) by alcohol induced injury was altered by CPP administration. The lipid peroxidation was also retarded by CPP by suppressing malondialdehyde (MDA) level and increasing the activity of liver superoxide dismutase (SOD). The findings from the present study suggested that CPP produced significant hepatoprotection and showed potential to be used as a dietary supplement or the ingredient of functional food.
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http://dx.doi.org/10.1039/d0fo01658fDOI Listing
November 2020

Preparation of coix seed oil bioactive delivery systems based on homologous polysaccharides and proteins.

Int J Biol Macromol 2020 May 18;151:376-383. Epub 2020 Feb 18.

College of Food & Biology Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang 310035, China.

Natural products belonging to a class of generally-recognized-as-safe biomaterials have exceptional biocompatibility and biodegradability and can be used as delivery vehicles for a variety of functional foods. Adlay (Coix lacryma-jobi), is a nutritious food, rich in various bioactive ingredients. Coix seed oil extract (CSO) is also bioactive but it is sensitive to oxidation. In this study, a bioactive delivery system based on homologous polysaccharides and proteins was developed to deliver coix seed oil. The results show that the CSO nanoparticles have high encapsulation efficiency, narrow particle size distribution, and good stability. Moreover, the fusion of the nanoparticles with the membrane enabled the transport of CSO through the Caco-2 cell monolayer and improved the intestinal permeability. These findings could provide useful information for designing homologous polysaccharide and protein-based delivery systems to increase the bioavailability of lipophilic nutraceuticals in the food industry.
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http://dx.doi.org/10.1016/j.ijbiomac.2020.02.171DOI Listing
May 2020

Platelet-to-lymphocyte ratio is an independent prognosticator in patients with esophageal squamous cell carcinoma receiving esophagectomy.

J Thorac Dis 2019 Nov;11(11):4583-4590

Department of Thoracic & Cardiovascular Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung.

Background: Systemic inflammation response is a crucial prognostic factor for various cancers. The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are two inflammation-based prognostic scores. The significance of preoperative NLR and PLR in patients with esophageal squamous cell carcinoma (ESCC) receiving curative esophagectomy remains largely undefined. Hence, this study aimed to evaluate the significance of preoperative NLR and PLR in patients with ESCC receiving curative esophagectomy in southern Taiwan.

Methods: A consecutive group of 107 patients with ESCC undergoing esophagectomy between January 2001 and December 2012 were retrospectively reviewed. The NLR and PLR of these 107 patients were calculated and correlated with clinicopathological parameters, overall survival (OS), and disease-free survival (DFS).

Results: NLR ≥2.5 was significantly correlated with higher T classification (P=0.006) and advanced clinical AJCC 7 stage (P=0.047). PLR ≥150 was significantly associated with higher T classification (P=0.009). Univariate survival analysis showed that NLR ≥2.5 and PLR ≥150 were associated with poor OS (P=0.009 and P=0.007, respectively) and poor DFS (P=0.006 and P=0.005, respectively). On multivariate comparison, PLR ≥150 was independently associated with poor OS [P=0.001, hazard ratio (HR): 2.475] and poor DFS (P<0.001, HR: 2.509). The 5-year overall and DFS rates were, respectively, 33.3% and 25.0% in patients with PLR ≥150, and 54% and 46% in patients with PLR <150.

Conclusions: The PLR is an independent prognosticator for patients with ESCC undergoing esophagectomy in southern Taiwan.
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http://dx.doi.org/10.21037/jtd.2019.11.06DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6940253PMC
November 2019

Preparation, characterization and anti-diabetic activity of polysaccharides from adlay seed.

Int J Biol Macromol 2019 Oct 2;139:605-613. Epub 2019 Aug 2.

Zhejiang Provincial Key Lab for Chem &Bio Processing Technology of Agricultural Products, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China.

Coix (Coix lachryma-jobi L.), commonly known as adlay, is a traditional Chinese medicine for thousands of years. A new water-soluble polysaccharide with anti-diabetic activity was extracted and purified from the adlay seed (PAS). The structure and physicochemical properties of PAS were determined by Fourier transform infrared spectrometer (FT-IR) and scanning electron microscopy (SEM). Structural analysis indicated that PAS had a porous surface and relatively loose distribution. After intragastric administered PAS for 4 weeks, biochemical analysis demonstrated dose dependent anti-diabetic activity. These results showed that PAS decreased blood glucose and insulin levels. In addition, mice fed the PAS showed significantly reduced the plasma levels of amyloid β and glycated hemoglobin (HbA1c), while the expression of glucagon-like peptide-1 (GLP-1) was markedly increased. Our study introduced a new polysaccharide PAS with unique anti-diabetic activity, which can be used as a potential dietary supplement or functional food.
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http://dx.doi.org/10.1016/j.ijbiomac.2019.08.018DOI Listing
October 2019

Effect of polysaccharides from adlay seed on anti-diabetic and gut microbiota.

Food Funct 2019 Jul;10(7):4372-4380

College of Food & Biology Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang 310035, China.

Diabetes is a chronic metabolic disease characterized by elevated blood glucose levels due to insulin resistance and β-cell dysfunction. This study aims to examine the effects of polysaccharides from adlay seeds (PAS) on hyperglycemia and gut microbiota in streptozocin (STZ)-induced diabetic mice. The administration of PAS in diabetic mice caused a significant decrease in the glucose level and serum levels of glycosylated hemoglobin (HbA1c). Similarly, PAS also showed decreased total cholesterol (TC) and triglyceride (TG) concentrations. Furthermore, a significant increase in the concentrations of glucagon-like peptide 1 (GLP-1) was observed. Unexpectedly, PAS reduced the concentrations of anti-amyloid beta (Aβ1-42) protein. Also, histopathological examination showed that PAS contributed to the reduction of STZ-lesioned pancreatic cells. Metformin treatment significantly reduced the diversity of the gut microbiota, while PAS treatment altered the diversity and composition of the microbiota. Collectively, our findings demonstrate that the hypoglycemic effects of PAS in type-2 diabetic mice (T2D) may be associated with the regulation of the intestinal microbiota and its metabolic pathways.
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http://dx.doi.org/10.1039/c9fo00406hDOI Listing
July 2019

Vesicle formation by ultrashort alkyl-phosphonic acids and serine in aqueous solutions.

Colloids Surf B Biointerfaces 2019 Jul 27;179:488-494. Epub 2019 Mar 27.

College of Food & Biology Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang 310035, China. Electronic address:

Vesicles possess unique biofilm structures and offer biomimetic advantages for drug and gene delivery. Herein, we report the spontaneous vesicle formation from ultrashort alkyl-phosphonic acids in the presence of amino acids. The aggregation characteristics and self-assembly structures of vesicles in aqueous solution were investigated by using dynamic light scattering, zeta potential, and cryo-transmission electron microscopy. We combined low-field nuclear magnetic resonance and Fourier transform infrared spectroscopy to study the H-proton-induced multilamellar vesicle formation. When we increased the molar fraction of serine, stable and closed spherical vesicles were formed at relatively low critical micelle concentrations. This transition of the self-assembled structure indicates that vesicle formation occurs when the chain length and the magnitude of the surface charge cause a fluctuation in the volume of the vesicle. Density functional theory reveals the critical role of the mixed alkyl-phosphonic acid/amino acid-enhanced electrostatic attraction between the head groups and hydrogen bonds associated with the aggregated states.
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http://dx.doi.org/10.1016/j.colsurfb.2019.03.055DOI Listing
July 2019

Vesicles from the self-assembly of the ultra-small fatty acids with amino acids under aqueous conditions.

Colloids Surf B Biointerfaces 2019 Jan 4;173:69-76. Epub 2018 Jul 4.

College of Food & Biology Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang 310035, China. Electronic address:

The properties of vesicles formed from the self-assembly of amphiphilic molecules can mimic the functionality of the natural lipid membranes. In this study, the self-assembly process of the amphiphilic structures formed by the interaction between ultra-small fatty acids [FAs, Cn (n = 4-8)] and amino acids (AAs) to generate vesicles under aqueous conditions were investigated in detail, along with the corresponding dynamic vesiculation mechanisms. Our results showed that the molar ratio of FAs/AAs and the chain length of FAs largely affected the structural characteristics and dispersion of vesicles. The detailed information about the entire size distributions and morphology of obtained vesicles were explored by the cryogenic transmission electron microscopy (Cryo-EM). Fourier transform infrared (FT-IR) spectra and quantum calculations suggested that the intermolecular hydrogen bond and electrostatic interactions between ultra-small molecules (FAs and AAs) during the aggregation processes were responsible for the formation of vesicles, where the hydrogen-bonding effect was dominant. Our findings shed new light on the effective and simple preparation of biological vesicles via ultra-small molecules self-assembly in aqueous solutions, which may have potential applications in vesicle physiology and drug delivery systems, and also get a mature understanding of the fundamental intermolecular interactions in life process.
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http://dx.doi.org/10.1016/j.colsurfb.2018.07.007DOI Listing
January 2019

Vesicle formation by proton transfer driven short-tailed fatty acids of C4-C8 chain length in water.

Soft Matter 2017 Feb;13(6):1291-1298

College of Food & Biology Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang 310035, China.

Ultrashort single-chain fatty acids self-assemble to form vesicles under certain proton-driven conditions. The protonation provides a larger charge area around the hydrophilic carbonyl headgroups, and proton shift as the key driving parameter was studied. The ultrashort fatty acids (C4-C8) formed stable unilamellar vesicles predominantly through out the whole range of tested pH levels (6.5-9.5). A proton-driven self-assembly process and effects on the phase transition were characterized by dynamic light scattering, transmission electron microscopy and cryo-transmission electron microscopy. In particular, we studied in greater detail the molecular packing characteristics of FA vesicles for geometric reasons and the protonation effect changes the molecular surface charge and further carboxylic acid headgroup motion. This study enhances the understanding of the physicochemical specificity of these membrane vesicles, and may facilitate the alteration of membrane function caused by FAs.
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http://dx.doi.org/10.1039/c6sm02307jDOI Listing
February 2017

Sweetness-induced activation of membrane dipole potential in STC-1 taste cells.

Food Chem 2016 Dec 7;212:768-77. Epub 2016 Jun 7.

College of Food & Biology Engineering, Zhejiang Gongshang University, Hangzhou, Zhejiang 310035, China. Electronic address:

The biological functions of cell membranes strongly influence the binding and transport of molecular species. We developed STC-1 cell line stably expressing the sweet taste receptor (T1R2/T1R3), and explored the possible correlation between sweeteners and membrane dipole potential of STC-1 cells. In this study, sweetener-induced dipole potential activation was elucidated using a fluorescence-based measurement technique, by monitoring the voltage sensitive probe Di-8-ANEPPS using a dual wavelength ratiometric approach. It indicated that the presence of sweeteners resulted in cell membrane dipole potential change, and interaction of artificial sweeteners with taste cells resulted in a greater reduction in potential compared with natural sweeteners. Our work presents a newly developed approach using a fluorescence-based measurement technique to study sweetener-induced dipole potential activation of STC-1 cells. This new approach could be used as a complementary tool to study the function of sweet taste receptors or other GPCRs and helps to understand the basis sweetness mechanism.
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http://dx.doi.org/10.1016/j.foodchem.2016.06.016DOI Listing
December 2016

Characterization of an acidic chitinase from seeds of black soybean (Glycine max (L) Merr Tainan No. 3).

PLoS One 2014 1;9(12):e113596. Epub 2014 Dec 1.

Department of Food and Nutrition, Providence University, Taichung, Republic of China (Taiwan).

Using 4-methylumbelliferyl-β-D-N,N',N″-triacetylchitotrioside (4-MU-GlcNAc3) as a substrate, an acidic chitinase was purified from seeds of black soybean (Glycine max Tainan no. 3) by ammonium sulfate fractionation and three successive steps of column chromatography. The purified chitinase was a monomeric enzyme with molecular mass of 20.1 kDa and isoelectric point of 4.34. The enzyme catalyzed the hydrolysis of synthetic substrates p-nitrophenyl N-acetyl chitooligosaccharides with chain length from 3 to 5 (GlcNAcn, n = 3-5), and pNp-GlcNAc4 was the most degradable substrate. Using pNp-GlcNAc4 as a substrate, the optimal pH for the enzyme reaction was 4.0; kinetic parameters Km and kcat were 245 µM and 10.31 min-1, respectively. This enzyme also showed activity toward CM-chitin-RBV, a polymer form of chitin, and N-acetyl chitooligosaccharides, an oligomer form of chitin. The smallest oligomer substrate was an N-acetylglucosamine tetramer. These results suggested that this enzyme was an endo-splitting chitinase with short substrate cleavage activity and useful for biotechnological applications, in particular for the production of N-acetyl chitooligosaccharides.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0113596PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4249961PMC
September 2015

Characterization of polyhydroxyalkanoate-producing bacteria isolated from sludge of commercial pig farms for producing methyl esters.

Water Sci Technol 2013 ;68(10):2171-7

Division of Applied Biology, Animal Technology Institute Taiwan, Chunan, Chinese Taiwan.

The objectives of this work were to isolate and characterize the polyhydroxyalkanoate (PHA) producing bacteria in enriched piggery sludge and make methyl esters from PHA for industrial applications. The strain ECAe24 isolated from piggery sludge with the highest PHA production was selected to produce PHA and then methyl ester by trans-esterification using glucose as substrate under mesophilic conditions. The final product after trans-esterification consisted of approximately 75.39% of fatty acid methyl ester and was identified as decanoic acid-3-hydroxy-methyl ester, octanoic acid-3-hydroxy-methyl ester, and some other contents. The novelty of this study is to use PHA-producing bacteria from piggery sludge to make fatty acid methyl esters which can be used as materials for producing biodiesel from piggery wastes.
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http://dx.doi.org/10.2166/wst.2013.474DOI Listing
March 2014

Organoaxial gastric volvulus caused by incarceration of a gastric stromal tumor in paraesophageal hiatal hernia.

Am Surg 2013 Sep;79(9):e312-3

Division of Gastrointestinal and General Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.

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September 2013

Characterisation of an acidic peroxidase from papaya (Carica papaya L. cv Tainung No. 2) latex and its application in the determination of micromolar hydrogen peroxide in milk.

Food Chem 2012 Dec 14;135(4):2529-35. Epub 2012 Jul 14.

Department of Food and Nutrition, Providence University, No. 200, Chungchi Rd, Shalu, Taichung 433-01, Taiwan, ROC.

An acidic peroxidase isoform, POD-A, with a molecular mass of 69.4 kDa and an isoelectric point of 3.5 was purified from papaya latex. Using o-phenylenediamine (OPD) as a hydrogen donor (citrate-phosphate as pH buffer), the optimum pH for the function of POD-A was 4.6, and the optimum temperature was 50°C. The peroxidase activity of POD-A toward hydrogen donors was both pH- and concentration-dependent. Under optimal conditions, POD-A catalysed the oxidation of OPD at higher rates than pyrogallol, catechol, quercetin and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The chemical modification reagents N-bromosuccinimide and sodium azide significantly inhibited POD-A activity. The results of kinetic studies indicated that POD-A followed a ping-pong mechanism and had a K(m) value of 2.8mM for OPD. Using CPC silica-immobilised POD-A for the determination of micromolar H(2)O(2) in milk, the lower limit of determination was 0.1 μM, and the recoveries of added H(2)O(2) were 96-109%.
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http://dx.doi.org/10.1016/j.foodchem.2012.06.106DOI Listing
December 2012

Laboratory identification, risk factors, and clinical outcomes of patients with bacteremia due to Escherichia coli and Klebsiella pneumoniae producing extended-spectrum and AmpC type β-lactamases.

J Microbiol Immunol Infect 2012 Jun 12;45(3):193-9. Epub 2012 May 12.

Division of Infectious Diseases, Department of Internal Medicine, Cathay General Hospital, Taipei City, Taiwan.

Background: Extended-spectrum β-lactamase (ESBL)-producing bacteria coexpressing AmpC type β-lactamase (ACBL) are associated with the laboratory issue of false susceptibility to third-generation cephalosporins. This study was to evaluate laboratory tests and clinical significance of bacteremic isolates of Escherichia coli and Klebsiella pneumoniae with both ESBL and ACBL [dual-type lactamases (DTL)].

Methods: From 2006 to 2009, 78 E coli and 12 pneumoniae bacteremic isolates with reduced susceptibility to cefotaxime (CTX) or ceftazidime (CAZ) were identified and relevant patients' data were collected for analysis. Phenotypic and genotypic characterizations of these selected isolates were determined by inhibitor-based assays and polymerase chain reaction-based genetic analyses, respectively.

Results: Among the 90 isolates, 47 had DTL production. There was an increasing annual prevalence from 29% in 2006 to 56% in 2009 (p=0.02). Phenotypic assays had a sensitivity and specificity of 57% (43/76) and 93% (13/14) for ESBL detection and 95% (58/61) and 34% (10/29) for ACBL, respectively. Among the DTL-producing isolates, phenotypic assays yielded a higher false negative rate of ESBL detection than that of ACBL detection (70% versus 6%), while all false negative ESBL results were associated with ESBL genes other than bla(CTx-M). The majority of the DTL-producing isolates were in the category of resistance to CTX (47/47, 100%) and CAZ (44/47, 94%) by the Clinical and Laboratory Standards Institute (CLSI) 2010 interpretive criteria, of which many were considered intermediate or fully susceptible to CTX (25/47, 53%) and CAZ (15/47, 32%) by the previous ones (CLSI-2009). The DTL-producing isolates exhibited a lower susceptibility rate to fluoroquinolones, aztreonam, and β-lactam/lactamase inhibitors than those with either ESBL or ACBL alone. The use of indwelling catheters or nasogastric tubes was associated with bacteremia due to the DTL isolates, but the mortality rates were not different among those due to isolates with ESBL, ACBL, or both. By multivariate analysis, Pittsburg bacteremia score and Charlson comorbidity index were the significant predictors for all-cause mortalities.

Conclusion: Bacteremic episodes due to DTL-producing E coli and K pneumoniae became increasingly prevalent and were often associated with coresistance to antibiotics other than β-lactams, but they were not associated with a worse prognosis than those due to ESBL- or ACBL-producing bacteria.
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http://dx.doi.org/10.1016/j.jmii.2011.11.003DOI Listing
June 2012

[Inhibition effects of ZGDHu-1 on proteasome in Kasumi-1 cells].

Zhonghua Xue Ye Xue Za Zhi 2012 Jan;33(1):61-3

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January 2012

Serotypes, surface proteins, and clinical syndromes of invasive Group B streptococcal infections in northern Taiwan, 1998-2009.

J Microbiol Immunol Infect 2011 Feb 12;44(1):8-14. Epub 2011 Jan 12.

Department of Internal Medicine, Cathay General Hospital, Taipei, Taiwan; Fu-Jen Catholic University School of Medicine, Hsinchuang, Taiwan.

Background: The incidence of invasive Group B streptococcal (GBS) infections is increasing in the elderly and immunocompromised adults in many countries worldwide. There are, however, few reports regarding the current status of the infection in northern Taiwan. This study investigated retrospectively the molecular epidemiology and clinical syndromes of the invasive GBS diseases in a tertiary care hospital in northern Taiwan over the past decade.

Methods: One hundred twenty episodes of invasive GBS disease were recorded at Cathay General Hospital, a tertiary care, teaching hospital in northern Taiwan, from January 1998 to June 2009. Clinical information was acquired from medical records. Capsular serotypes and alpha family of surface proteins were genotyped with multiplex and specific polymerase chain reaction.

Results: Of all episodes, 58.3% was found in the elderly (age ≥ 65), 36.1% in nonpregnant women and young adults (age 18-64), and 5.9% in the neonates (0-90 days). Case-fatality rate was 6.7%. Eighty-three (69%) of the invasive isolates were available for genotyping. In sharp contrast to the studies in southern Taiwan (1991-2004), Type Ib (26.5%) was the most frequent invasive isolate, followed by V (22.9%), III (18.1%), VI (12%), Ia (10.8%), II (6%), VIII (2.4%), and nontypable strain (1.2%). In particular, Serotype VI, which had been rarely implicated in invasive infection, emerged as a significant pathogen. A significant trend of increase in incidence was observed for the infection (p<0.0001), with concurrent increase of cases in the elderly and of Serotype Ib and VI. There was significant association with young adults of Type II and III and chronic skin conditions and older adults with Type Ia and V and chronic cardiovascular diseases. Type V was closely associated with skin and soft tissue infection. Recurrent episodes (10%) occurred most often in patients with concomitant malignancy, with an average of 314 days for recurrence.

Conclusions: The incidence of GBS invasive infection among nonpregnant women and adults is rising in northern Taiwan, particularly in the elderly caused by Serotype Ib and VI. Population-based surveillance program should be implanted for assessment of the disease burden to the susceptible adult population.
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http://dx.doi.org/10.1016/j.jmii.2011.01.003DOI Listing
February 2011

Ligand-receptor recognition for activation of quorum sensing in Staphylococcus aureus.

J Microbiol 2009 Oct 24;47(5):572-81. Epub 2009 Oct 24.

Division of Infectious Diseases, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan.

The accessory gene regulator (agr) locus controls many of the virulence toxins involved in Staphylococcus aureus pathogenesis, and can be divided into four specificity groups. AgrC is the only group-specific receptor to mediate both intra-group activation and inter-group inhibition. We studied the ligand-receptor recognition of the agr system in depth by using a luciferase reporter system to identify the key residues responsible for AgrC activation in two closely related agr groups, AgrC-I, and AgrC-IV. Fusion PCR and site-directed mutagenesis were used to screen for functional residues of AgrC. Our data suggest that for AgrC-IV activation, residue 101 is critical for activating the receptor. In contrast, the key residues for the activation of AgrC-I are located at residues 49 approximately 59, 107, and 116. However, three residue changes, T101A, V107S, I116S, are sufficient to convert the AIP recognizing specificity from AgrC-IV to AgrC-I.
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http://dx.doi.org/10.1007/s12275-009-0004-2DOI Listing
October 2009

Purification, crystallization and preliminary X-ray crystallographic analysis of xylose reductase from Candida tropicalis.

Acta Crystallogr Sect F Struct Biol Cryst Commun 2009 Apr 26;65(Pt 4):419-21. Epub 2009 Mar 26.

Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.

Xylose reductase (XR), which requires NADPH as a co-substrate, catalyzes the reduction of D-xylose to xylitol, which is the first step in the metabolism of D-xylose. The detailed three-dimensional structure of XR will provide a better understanding of the biological significance of XR in the efficient production of xylitol from biomass. XR of molecular mass 36.6 kDa from Candida tropicalis was crystallized using the hanging-drop vapour-diffusion method. According to X-ray diffraction data from C. tropicalis XR crystals at 2.91 A resolution, the unit cell belongs to space group P3(1) or P3(2). Preliminary analysis indicated the presence of four XR molecules in the asymmetric unit, with 68.0% solvent content.
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http://dx.doi.org/10.1107/S1744309109008719DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2664776PMC
April 2009

Preparation of gradually componential metal electrode on solution-casted Nafion membrane.

Biomol Eng 2007 Nov 1;24(5):434-7. Epub 2007 Aug 1.

Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 402, Taiwan, Republic of China.

A typical ionic polymer-metal composite consists of a thin perfluorinated ionomer membrane and noble metal electrodes plated on both surfaces. It undergoes a large bending motion when an electric field is applied hence exhibits deformation by a certain amount of cation. With proper arrangement and package, a great number of "smart devices" are anticipated. In this study, a solution-cast route was used to prepare the electro-active polymer membrane and platinum electrodes were fabricated onto the membrane through electro-less plating. The ionic polymer used is the commercial Nafion, the perfluoro-sulfonated ionomer membrane, developed by DuPont Co. Nafion membrane was cast by the solution-casting route and then loaded with different weights simultaneously. The optimized processing conditions, membrane properties and electrodes behaviors were investigated. The results of shift in WAXD peaks showed that weights delineated the crystallinity of the solution-cast membranes. The number and size of the crystalline domains of solution-cast membrane decrease as studied by SAXS. The Young's modulus of solution-cast membrane decreases as increasing weight because of the loss of crystallinity (180-140 MPa). A finely dispersed platinum particle deeper and gradient penetrating within the near-boundary region with a smaller average particle size and more uniform distribution could be obtained through a reverse electro-less plating. Its surface roughness is 3 nm comparing to 52 nm of a typical process. But its surface resistance is too high (3.5 Omega) to activate the bending motion. To solve this problem, we coated the second Pt electrodes by a typical electro-less plating, and the resistance decreased to 0.7 Omega. The results depicted that the fabricated IPMC shows longer bending lifetime than typical IPMC. In a 0.09% NaCl solution, the device was able to vibrate for 8h under a 5 V, 0.1 Hz actuation.
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http://dx.doi.org/10.1016/j.bioeng.2007.07.003DOI Listing
November 2007

Pathological and molecular studies on mycobacteriosis of milkfish Chanos chanos in Taiwan.

Dis Aquat Organ 2006 Oct;72(2):147-51

Department of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 912, Taiwan.

investigated in milkfish Chanos chanos, which had a cumulative mortality of up to 66.7% over the course of 1 yr. Gross reddish- or greyish-white nodules appeared on the peritoneal surface, spleen, kidney, liver and gastrointestinal (GI) tract. Epithelioid granulomas with the formation of Langhan's type giant cells were the prominent histopathological changes. Despite large numbers of acid-fast bacilli in the granulomas, neither caseous necrosis nor dystrophic calcification were observed. Using degenerate primers that targeted the heat shock protein 65 kDa gene of Mycobacterium spp., a 441 bp product was amplified. When compared with published sequences, our products were identical to those of Mycobacterium abscessus Type II (GenBank accession number AY603554). This is the first report of M. abscessus infection in milkfish.
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http://dx.doi.org/10.3354/dao072147DOI Listing
October 2006

catena-Poly[diaquabis(5-chloropyridinium-2-olato-kappaO)copper(II)]-mu-pyrazine-kappa2N:N'] diperchlorate].

Acta Crystallogr C 2002 Apr 29;58(Pt 4):M270-2. Epub 2002 Mar 29.

Department of Chemistry, Wenzhou Normal College, Wenzhou 325027, People's Republic of China.

In the title compound, [Cu(C(5)H(4)ClNO)(2)(C(4)H(4)N(2))(H(2)O)(2)](ClO(4))(2), the Cu atom, which lies on an inversion centre, has an octahedral environment. The pyrazine ligand also lies about an inversion centre and links adjacent Cu atoms into a chain running along the b axis; perchlorate anions occupy the space between the chains, and the chains use the coordinated water molecules to link to the anions, resulting in a hydrogen-bonded ribbon structure. The donor 5-chloro-2-hydroxypyridine ligand exists in the zwitterionic form, i.e. 5-chloropyridinium-2-olate.
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http://dx.doi.org/10.1107/s0108270102003852DOI Listing
April 2002