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Biomedical subjects

C H Cheng

Publications and source records attributed to C H Cheng.

At least 19 recordsLinked to original sources
PubMed2006

Association study of genetic polymorphisms of SLC2A10 gene and type 2 diabetes in the Taiwanese population.

AIMS/HYPOTHESIS: The gene encoding solute carrier family 2, facilitated glucose transporter, member 10 (SLC2A10, previously known as glucose transporter 10 [GLUT10]) is a promising candidate gene for type 2 diabetes since it is highly expressed in liver and pancreas and is located on human chromosome region 20q12-q13.1, a region previously shown to harbour type 2 diabetes susceptibility genes. We investigated whether the SLC2A10 gene could be a type 2 diabetes susceptibility gene in the Taiwanese population. SUBJECTS AND METHODS: Sequencing of SLC2A10 gene from 48 diabetic subjects detected short tandem repeat polymorphisms in the promoter region, but did not detect any other sequence variants or new single-nucleotide polymorphisms (SNPs) other than those already in the SNPper database ( http://snpper.chip.org ) (30 June 2005). RESULTS: Using these genetic polymorphisms, we divided the SLC2A10 gene into four distinct linkage disequilibrium blocks and performed a case-control association study in a group of type 2 diabetes subjects (n = 375) and normoglycaemic individuals (n=377). The HapD (A-G-T-C) haplotype in block 3, a rare haplotype, which consisted of four SNPs (rs3092412, rs2235491, rs2425904 and rs1059217), was modestly associated with type 2 diabetes with a haplotype score of -2.95567 (p = 0.012 with the haplotype-specific test). CONCLUSIONS/INTERPRETATION: Our results suggest that SLC2A10 genetic variations do not appear to be major determinants for type 2 diabetes susceptibility in the Taiwanese population.

Aged↗
PubMed2006

Acute pancreatitis following antilymphocyte globulin therapy in a renal transplant recipient.

Acute pancreatitis is a rare complication following OKT3 therapy, which to our knowledge has never been reported in patients treated with antilymphocyte globulin (ALG). We herein report a case of a kidney transplantation patient who developed acute pancreatitis 2 days after treatment with ALG for grade IIb acute rejection. The symptoms subsided after discontinuing this drug. Resumption of ALG therapy triggered another episode of acute pancreatitis. Therefore, the clinical course strongly suggests that ALG was the etiological factor of acute pancreatitis in this particular patient.

Acute Disease↗
PubMed2005

Polymerization of w/o microemulsions for the preparation of transparent SiO2/PMMA nanocomposites.

Reverse w/o microemulsions composed of methyl methacrylate (MMA) forming the oil phase, nonionic surfactants, and water are used for the synthesis of transparent SiO2/PMMA nanocomposites. An inorganic precursor, tetraethoxysilane (Si(OEt)(4), TEOS), is hydrolyzed in the reverse micelles containing aqueous ammonia. During the hydrolysis of TEOS, polymerization of the continuous MMA phase is initiated using AIBN (azobisisobutyronitrile), and after thermal polymerization at 333 K for 12 h, solid blocks of PMMA are obtained in which nanometer-sized silica particles are trapped in the solid polymer matrix. According to small-angle X-ray and dynamic light scattering experiments, the water droplets in MMA microemulsions are 12 nm (R(W) = 13) in diameter, whereas after polymerization of the microemulsion, the SiO2 particles in the transparent SiO2/PMMA composites are 26 nm in diameter. Transmission electron micrographs demonstrate a low degree of agglomeration in the composites. In comparison with materials generated from micelle-free solutions, the particle size distribution is narrow. The reverse micelle-mediated approach produces composites of high transparency comparable with that of pure PMMA.

Journal Article↗
PubMed2005

Improving aerobic power in primary school boys: a comparison of continuous and interval training.

The purpose of this study was to assess whether the magnitude of change in aerobic power was different in boys (mean age 10.25 +/- 0.50 y) who followed a high-intensity interval training protocol, compared to those who followed a moderate-intensity continuous training protocol. Boys were assigned to either a control group (n = 15), a continuous training group (n = 10), or an interval training group (n = 10). They completed peak oxygen uptake tests at baseline and following an 8-week training period. The control group continued with normal activity habits, whilst the continuous training group followed a 20-minute steady-state cycle protocol at 80-85 % of the maximal heart rate, and the interval training group completed 30-s sprints on a cycle ergometer, interspersed with active rest periods. The two training protocols were designed to incur similar cardiovascular work over the 20 minutes of each training session. Significant increases (p < 0.05) in peak oxygen uptake were noted for both the interval and continuous training groups. The interval training group showed marked pre- to post-increases in both peak oxygen pulse, oxygen pulse at the ventilatory threshold, and ventilatory threshold that were not apparent in the continuous group boys. It would appear that a high-intensity interval protocol confers a different training effect in comparison to continuous steady-state training in boys. Possible mechanisms that underpin these adaptations may include increased blood volume and a concomitant adjustment in stroke volume.

Adaptation, Physiological↗
PubMed2005

Turbulent flow evaluation of the venous needle during hemodialysis.

Arteriovenous (AV) grafts and fistulas used for hemodialysis frequently develop intimal hyperplasia (IH) at the venous anastomosis of the graft, leading to flow-limiting stenosis, and ultimately to graft failure due to thrombosis. Although the high AV access blood flow has been implicated in the pathogenesis of graft stenosis, the potential role of needle turbulence during hemodialysis is relatively unexplored. High turbulent stresses from the needle jet that reach the venous anastomosis may contribute to endothelial denudation and vessel wall injury. This may trigger the molecular and cellular cascade involving platelet activation and IH, leading to eventual graft failure. In an in-vitro graft/needle model dye injection flow visualization was used for qualitative study of flow patterns, whereas laser Doppler velocimetry was used to compare the levels of turbulence at the venous anastomosis in the presence and absence of a venous needle jet. Considerably higher turbulence was observed downstream of the venous needle, in comparison to graft flow alone without the needle. While turbulent RMS remained around 0.1 m/s for the graft flow alone, turbulent RMS fluctuations downstream of the needle soared to 0.4-0.7 m/s at 2 cm from the tip of the needle and maintained values higher than 0.1 m/s up to 7-8 cm downstream. Turbulent intensities were 5-6 times greater in the presence of the needle, in comparison with graft flow alone. Since hemodialysis patients are exposed to needle turbulence for four hours three times a week, the role of post-venous needle turbulence may be important in the pathogenesis of AV graft complications. A better understanding of the role of needle turbulence in the mechanisms of AV graft failure may lead to improved design of AV grafts and venous needles associated with reduced turbulence, and to pharmacological interventions that attenuate IH and graft failure resulting from turbulence.

Arteriovenous Anastomosis↗
PubMed2004

Dissociation energies of molecular hydrogen and the hydrogen molecular ion.

We have obtained improved values for the dissociation energies of molecular hydrogen and its ion by using a high-resolution pulse-amplified laser to probe the second dissociation limit. The onset of the vibrational continuum is observed by state-selective detection of the atomic products of dissociation, and several auxiliary measurements link the results to the ground state. The dissociation energies are accurate to 0.010-0.026 cm(-1), improving previous measurements by a factor of 3-7. Agreement with ab initio calculations is good for H2, D2, and their ions, but not for HD and HD+.

Journal Article↗
PubMed2004

Biodegradation of phthalate esters by two bacteria strains.

In this study two aerobic phthalic acid ester (PAE) degrading bacteria strains, DK4 and O18, were isolated from river sediment and petrochemical sludge, respectively. The two strains were found to rapidly degrade PAE with shorter alkyl-chains such diethyl phthalate (DEP), dipropyl phthalate (DPrP), di-n-butyl phthalate (DBP), benzylbutyl phthalate (BBP) and diphenyl phthalate (DPP) are very easily biodegraded, while PAE with longer alkyl-chains such as dicyclohexyl phthalate (DCP) and dihexyl phthalate (DHP) and di-(2-ethylhexyl) phthalate (DEHP) are poorly degraded. The degradation rates of the eight PAEs were higher for strain DK4 than for strain O18. In the simultaneous presence of strains DK4 and O18, the degradation rates of the eight PAEs examined were enhanced. When the eight PAEs were present simultaneously, degradation rates were also enhanced. We also found that PAE degradation was delayed by the addition of nonylphenol or selected polycyclic aromatic hydrocarbons (PAHs) at a concentration of 1 microg/g in the sediment. The bacteria strains isolated, DK4 and O18, were identified as Sphigomonas sp. and Corynebacterium sp., respectively.

Biodegradation, Environmental↗
PubMed2004

Cloning and expression of Tsaiya duck liver fatty acid binding protein.

Liver basic fatty acid (FA)-binding protein (Lb-FABP) cDNA was cloned from the livers of laying Tsaiya ducks and used to generate probes for quantification of the Lb-FABP mRNA in Tsaiya ducks. The full-length Lb-FABP cDNA of the Tsaiya duck was highly homologous with that of the mallard (99%), chicken (88%), and iguana (73%). The amino acid sequence was also highly homologous to Lb-FABP found in birds and reptiles, indicating a similar function of the Tsaiya duck Lb-FABP to those species. The calculated molecular weight for the cloned duck Lb-FABP was 14,043g/mol. The Lb-FABP was highly expressed in the liver of laying Tsaiya ducks and not detectable in heart, ovary, intestine, or adipose tissues. The expression of Tsaiya duck Lb-FABP in the skeletal muscle was also detected, and the sequence was confirmed. The greater expression of the hepatic Lb-FABP in the egg-laying Tsaiya ducks than the prelaying ducks paralleled the higher FA use by the laying ducks. These results suggest that hepatic Lb-FABP may be needed for egg production when FA metabolism is high for the ducks. Feeding laying Tsaiya ducks with diets enriched with 2% docosahexaenoic acid (DHA) oil for 2 wk significantly increased hepatic DHA content compared with in ducks fed a 2% butter basal diet. There was no effect of dietary DHA enrichment on the expression of Lb-FABP in the liver of Tsaiya ducks. The results suggest that even though the Lb-FABP may be involved in hepatic FA metabolism, the effect of individual FA on liver Lb-FABP in laying Tsaiya ducks needs to be further studied.

Amino Acid Sequence↗
PubMed2004

Risk factors for peptic ulcer disease in renal transplant patients--11 years of experience from a single center.

BACKGROUND: Peptic ulcer disease is a common complication among renal transplant recipients and causes significant morbidity and mortality. METHODS: From 1990 through 2000, 465 renal transplant patients were followed-up in our institute. Most patients received corticosteroids and cyclosporine-based immunosuppressive regimen. About one third (n = 156) of them received mycophenolate mofetil. Patients with endoscopy-proved peptic ulcer disease were identified by reviewing medical records. Possible risk factors were analyzed by univariate analysis and multiple logistic regression analysis. RESULTS: Among 465 kidney transplant patients, there were 181 (38.9%) who suffered at least 1 episode of peptic ulcer disease. The most frequent types of peptic ulcer disease were gastritis, gastric ulcer, duodenal ulcer, esophagitis, duodenitis and esophageal ulcer. By multivariate analysis, the use of methylprednisolone pulse therapy (odds ratio = 3.954, 95% confidence interval = 3.154-18.312, p = 0.03) and history of pre-transplant peptic ulcer disease (odds ratio = 7.599, 95% CI = 1.211-12.905, p < 0.0001) were independent risk factors for posttransplant peptic ulcer disease. CONCLUSIONS: Our findings demonstrated that renal transplant patients who undergo methylprednisolone pulse therapy for acute rejection or who have a history of pre-transplant peptic ulcer disease carry a high risk for the development of peptic ulcer disease and deserve intensive antiulcer treatment.

Adolescent↗
PubMed2003

The Effects of CPOE on ICU workflow: an observational study.

Computerized physician order entry (CPOE) has had demonstrated benefits in error reduction and guideline adherence, but its implementation has often been complicated by disruptions in established workflow processes. We conducted an observational study of the healthcare team in an intensive care unit after the implementation of mandatory CPOE. We found that policies designed to increase flexibility and safety led to an increased coordination load on the healthcare team, and created opportunities for new sources of error. We attribute this in part to implicit assumptions in the CPOE system design that execution of physician orders is a linear work process. Observational workflow studies are an important tool to understand how to redesign CPOE systems so as to avoid harm and achieve the full potential of benefit for improved patient safety.

Attitude of Health Personnel↗
PubMed2002

The ultrastructure of the mature spermatozoon of the bivalve Gafrarium tumidum (Bivalvia, Heterodonta, Veneridae, Circinae).

Using transmission and scanning electron microscopy, we have described the mature spermatozoon of the bivalve Gafrarium tumidum (Heterodonta, Veneridae, Circinae) for the first time. The spermatozoon of G. tumidum is the ect-aquasperm type. The head contains a slightly curved nucleus. At its apex is a short cone-shaped acrosome. The structure of the acrosome is typical of heterodont bivalves and two major components of the acrosome vesicle material can be distinguished. The midpiece is an annular band of five mitochondria which surround the centriole complex. Sperm ultrastructure of G. tumidum provides additional information for the existing Veneridae phylogeny.

Animals↗
PubMed2001

Cross [2 + 2] cycloaddition of bicyclic alkenes with alkynes mediated by cobalt complexes: a facile synthesis of cyclobutene derivatives.

Bicyclic alkenes 1a-e and 5 undergo [2 + 2] cycloaddition with a variety of alkynes PhC(triple bond)CPh, (TMS)C(triple bond)CH, HC(triple bond)C(CH(3))(2)OH, (TMS)C(triple bond)CCO(2)Et, PhC(triple bond)CCH(3), C(2)H(5)C(triple bond)CC(2)H(5), CH(3)C(triple bond)CC(3)H(7), and CH(3)C(triple bond)CC(2)H(5) in the presence of Co(PPh(3))(2)I(2), PPh(3), and Zn powder in toluene to afford the corresponding exo-cyclobutene derivatives 3a-m, 6, and 8a-g in fair to excellent yields. The yield of this cycloaddition is highly sensitive to the cobalt catalyst, solvent, ligand, and temperature used. A mechanism involving a metallacyclopentene intermediate is proposed to account for this cobalt-catalyzed cyclization.

Journal Article↗
PubMed2001

Molecular cloning of a teleost growth hormone receptor and its functional interaction with human growth hormone.

This paper reports the first full-length cDNA sequence of a growth hormone receptor (GHR) from a teleost fish and its functional expression in cultured eukaryotic cells. The cDNA sequence, from Carassius auratus (goldfish), encodes a protein of 602 amino acids (aa) akin in architecture to the GHRs of other species. Despite the presence of motifs characteristic of GHR, the overall homology between the goldfish GHR and other GHRs is very low ( approximately 40% aa identity). CHO cells transfected with this receptor cDNA can be stimulated to proliferate by human growth hormone (hGH). In addition, the transfected cells can transactivate a co-expressed mammalian serine protease inhibitor (Spi) 2.1 promoter upon stimulation by hGH, indicating the successful interaction of the fish receptor with the mammalian ligand to evoke the down-stream post-receptor events. Tissue distribution studies indicated that the receptor is mostly expressed in the liver and hypothalamus of goldfish. A single mRNA transcript of a size of about 4 kb was found in the goldfish liver.

Amino Acid Sequence↗
PubMed2001

Simultaneous monitoring of extracellular glucose, pyruvate, lactate and glutamate in gerbil cortex during focal cerebral ischemia by dual probe microdialysis.

The aim of this study was to monitor dynamic changes in energy-related metabolites in the cortex of gerbils subjected to cerebral ischemia by a dual probe microdialysis technique. Focal cerebral ischemia was produced in anesthetized gerbils by occlusion of the right common carotid artery and the right middle cerebral artery for 60 min. Two microdialysis probes were inserted into both sides of the cortex to simultaneously monitor extracellular glucose, lactate, pyruvate and glutamate. Dynamic and comparative changes in these analytes, on the ipsilateral and contralateral sides of the brain, were simultaneously monitored by liquid chromatography and a microdialysis analyzer. The present study demonstrated decreases in glucose and pyruvate, increases in lactate and glutamate on the ipsilateral side whereas all analytes remain constant on the contralateral side of cortex during cerebral ischemia. In vitro recovery of each microdialysis probe was performed to ensure the quality of experiments. The detection limits of pyruvate, glutamate, lactate and glucose were 0.2, 1.0, 2.0 and 20 microM, respectively. The intra- and inter-assay correlations were less than 5% in standard mixtures and pooled brain dialysates.

Animals↗
PubMed2001

Synthesis of biaryls via unusual deoxygenative dimerization of 1,4-epoxy-1,4-dihydroarenes catalyzed by palladium complexes.

Treatment of various 1,4-epoxy-1,4-dihydroarenes with trichlorosilane in toluene in the presence of a palladium complex affords the corresponding biaryls in good to excellent yields. The process appears to occur via a novel palladium-catalyzed hydrosilylative dimerization of 1,4-epoxy-1,4-dihydroarenes and subsequent elimination of HOSiCl(3) and H(2)O.

Journal Article↗
PubMed2001

Inotropic and chronotropic actions of Ilex latifolia inhibition of adenosine-5 '-triphosphatases as a possible mechanism.

Ilex latifolia is widely used as an ingredient to prepare traditional beverage drinks in southern China. In fact, various Ilex species have been used in Chinese folk medicine to treat coronary heart diseases. The mode of action is believed to be mediated by their coronary vasodilative effects. In this study, the water extract of the leaves of Ilex latifolia (IK-TP) was shown to increase the contractility and decrease the frequency of contraction in an isolated rat heart perfusion system. IK-TP was found to inhibit Na+/K+-ATPase activities in rat heart sarcolemma, rat brain microsomes and a purified enzyme from porcine cerebral cortex. IK-TP also inhibited Ca2+-dependent ATPase at a similar dose. Following exposure of the isolated rat heart to IK-TP at a dose that produces pronounced cardiac effects, inhibition of Na+/K+-ATPase activity can be readily detected in the heart. This study suggests the presence of ATPase inhibitory compounds in Ilex latifolia with specificities different from that of ouabain.

Animals↗