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Biomedical subjects

C L Wang

Publications and source records attributed to C L Wang.

At least 37 records · Page 2Linked to original sources
PubMed2001

Altered cellular but not humoral reactions in children with complicated enterovirus 71 infections in Taiwan.

Enterovirus 71 (EV 71) infections have high neurovirulence and fatality. Immune responses were assessed in 78 patients with EV 71 infection. EV 71 meningoencephalitis occurred more frequently in younger children and in boys. C-reactive protein levels were not elevated, although total leukocyte counts were increased in these patients. The CD40-ligand expression on T cells significantly decreased in children with meningoencephalitis (P=.041). Polymorphism of the cytotoxic T lymphocyte antigen-4 (CTLA-4) at position 49 of exon 1 showed a higher frequency of G/G genotype in patients with EV 71 meningoencephalitis than in those without meningoencephalitis (18/31 vs. 14/47; P=.045) and in control subjects (18/31 vs. 25/93l; P=.007). Specific EV 71 neutralizing antibody titers were detectable but did not differ in children with and without meningoencephalitis in the acute and convalescent stages. Results from this study suggest that younger children with a certain CTLA-4 polymorphism and altered cellular but not humoral response may be linked to EV 71 meningoencephalitis.

Abatacept↗
PubMed2001

Aerobic sulfide production and cadmium precipitation by Escherichia coli expressing the Treponema denticola cysteine desulfhydrase gene.

The cysteine desulfhydrase gene of Treponema denticola was over-expressed in Escherichia coli to produce sulfide under aerobic conditions and to precipitate metal sulfide complexes on the cell wall. When grown in a defined salts medium supplemented with cadmium and cysteine, E. coli producing cysteine desulfhydrase secreted sulfide and removed nearly all of the cadmium from solution after 48 h. A control strain produced significantly less sulfide and removed significantly less cadmium. Measurement of acid-labile sulfide and energy dispersive X-ray spectroscopy indicated that cadmium was precipitated as cadmium sulfide. Without supplemental cysteine, both the E. coli producing cysteine desulfhydrase and the control E. coli demonstrated minimal cadmium removal.

Aerobiosis↗
PubMed2001

Noninvasive assessment of laryngeal phonation function using color Doppler ultrasound imaging.

Color Doppler imaging (CDI) was used to identify the morphology of vocal folds (VF) and to quantify the tissue horizontal displacement velocity (HDV) in the vibrating portion of VF. Mucosal HDV that gives an estimate of the stiffness of the VF cover is very important clinically. The VF and its cover were shown to be very hypoechoic and not adequately visible in B-scan image. However, in this study, we found that the structure of the true VF, especially the mucosa and the superficial layer of the lamina propria, the so-called "cover," can be easily identified and evaluated using CDI. The mean VF displacement velocity was measured by decoding the pseudocolor codes of the ultrasound (US) image at the vibrating sites. The mucosal mean HDV obtained from 10 normal men of age 34 +/- 8 years phonating at their most comfortable pitch and intensity (98 +/- 12 Hz, 55-65 dB) was about 68 +/- 10 cm/s, which agreed reasonably with the literature. Therefore, the CDI could be used as a potential tool for assessing the phonation function in the larynx nonintrusively.

Adult↗
PubMed2001

Noninvasive assessment of vocal fold mucosal wave velocity using color doppler imaging.

The vibratory movement of the vocal folds (VF) plays an important role in normal function of phonation. We developed a noninvasive technique to quantify the human mucosal wave velocity (MWV) in vivo using color Doppler imaging (CDI). During phonation, the motion of mucosa-air interface generates a unique pattern of US color artefacts that assist the identification of true VF location. An in vitro study using a vibrating string phantom was conducted to investigate how the CDI displayed a vibrating soft tissue at high frequency. The vibrating amplitude, frequency, mass density and the acoustic impedance of the soft tissues were found to dominate the formation of color artefacts. Based on the model of finite string with fixed ends, we estimated the mean MWV for 10 adult volunteers (6 men, 4 women, ages 34 +/- 5 years) with normal VF function. The mean MWVs for the men were found to vary from 2.1 to 10 m/s in a frequency range of 85 to 310 Hz at their comfortable pitch and intensity, and the women typically had higher MWVs that varied from 5.0 to 16.5 m/s in a frequency range of 180 to 480 Hz. The MWV increased linearly with the frequency and there was no observable difference in mucosa stiffness due to the effect of gender. The variation in MWV as it propagates vertically can be seen from the color and shape of the artefacts. The VF polyp resulted in abnormal MWV and different CDI vibratory artefacts. The CDI artefacts provide insight on the dynamics of mucosa structure during phonation, and the method presented is promising for noninvasive monitoring of laryngeal functions clinically.

Adult↗
PubMed2001

Caldesmon exhibits a clustered distribution along individual chicken gizzard native thin filaments.

Our earlier immuno-gold electron microscopic study indicated that the distribution of caldesmon (CaD) on actin filaments is not uniform and is restricted to the vicinity of the myosin filaments (Mabuchi K, Li Y, Tao T, Wang CLA (1996) J Muscle Res Cell Motil 17: 243). This suggested that CaD could effectively inhibit muscle contraction, if those actin filaments in the vicinity of myosin filaments were saturated with CaD. In the present study we further examined the distribution of CaD along isolated, crude and purified native thin filaments (NTF). Individual CaD molecules on purified NTF were visualized with the aid of a chemical crosslinker, 5,5'-dithiobis(2-nitrobenzoic acid), which efficiently crosslinks CaD to actin (Graceffa P, Adam LP, Lehman W (1993) Biochem J294: 63), and of a monoclonal anti-CaD antibody. The results indicated that individual NTF had alternating CaD-rich and CaD-deficient regions. Moreover, we found that the N-termini of all CaD molecules in a given cluster appeared on the same side of an actin filament. Electron microscopic images of crude NTF immunoprecipitated by a polyclonal antibody clearly indicated that the spacing between the CaD clusters is wide enough for myosin heads to interact with actin subunits. Similar clustering of CaD was also observed in plastic embedded tissue sections. These observations raise the possibility that CaD is not acting as a simple on/off switch, but more likely as a modulator, of smooth muscle contraction.

Actin Cytoskeleton↗
PubMed2001

Early growth restriction, membrane phospholipid fatty acid composition, and insulin sensitivity.

An animal model of protein restriction during pregnancy and lactation with subsequent dietary fatty acid manipulation was used to investigate the association between poor early growth, defective unsaturated fatty acid handling, and later disease. Both control and early growth-restricted animals fed a diet rich in saturated fatty acids showed a doubling of the plasma insulin levels as well as a reduced degree of unsaturation in liver and skeletal muscle membrane phospholipids compared with animals fed diets rich in unsaturated fatty acids. The skeletal muscle of early growth-restricted animals weaned onto a saturated fat diet had reduced proportions of 22:6n-3 and increased proportions of 18:1n-9. This reduction in 22:6n-3 is similar to that observed in Pima Indians, a population with a high prevalence of type 2 diabetes.

Animals↗
PubMed2001

Isolation of a benzoate-utilizing Pseudomonas strain from soil and production of catechol from benzoate by transpositional mutants.

Pseudomonas sp. Ba-0511 was isolated from soil by enrichment cultivation on a medium containing 6 mg/ml of sodium benzoate. The bacterium could grow on a medium containing 20 mg/ml of sodium benzoate by a successive enrichment culture. One hundred and twelve transpositional mutants of the bacterium produced catechol from benzoate and accumulated it outside of the cells. Among the mutants, strain BA+63 produced a maximal amount of catechol (2.3 mg/ml) from 6 mg/ml of sodium benzoate after growing for 10.5 h. The conversion rate of benzoate to catechol was 50% on a molar basis. The catechol production by the resting cells increased in the presence of glycerol, and the maximal amount of catechol produced from 6 mg/ml of sodium benzoate reached 3.3 mg/ml at the conversion rate of 72% after 5 h of incubation. The resting cells converted m-methylbenzoic acid to 3- and 4-methylcatechol and m-chlorobenzoic acid to 3- and 4-chlorocatechol.

Benzoates↗
PubMed2001

Impaired PI 3-kinase activation in adipocytes from early growth-restricted male rats.

Epidemiological studies have established a relationship between early growth restriction and subsequent development of type 2 diabetes. Animal studies have shown that offspring of protein-restricted rats undergo a greater age-related loss of glucose tolerance than controls. The aim of this study was to investigate the possibility that this deterioration of glucose tolerance is associated with changes in adipocyte insulin action. Adipocytes from low-protein offspring had higher basal levels of glucose uptake than controls. Insulin stimulated glucose uptake into control adipocytes but had little effect on low-protein adipocytes. Both groups had similar levels of basal and isoproterenol-stimulated lipolysis. Insulin inhibited lipolysis in control adipocytes but had a reduced effect on low-protein adipocytes. These changes in insulin action were not related to altered expression of insulin receptors or insulin receptor tyrosine phosphorylation; however, they were associated with reduced phosphatidylinositol 3-kinase and protein kinase B activation. These results demonstrate that reduced glucose tolerance observed in late adult life after early growth restriction is associated with adipocyte insulin resistance.

Adipocytes↗
PubMed2001

Myosin light chain kinase- and PKC-dependent contraction of LES and esophageal smooth muscle.

In smooth muscle cells enzymatically isolated from circular muscle of the esophagus (ESO) and lower esophageal sphincter (LES), ACh-induced contraction and myosin light chain (MLC) phosphorylation were similar. Contraction and phosphorylation induced by purified MLC kinase (MLCK) were significantly greater in LES than ESO. ACh-induced contraction and MLC phosphorylation were inhibited by calmodulin and MLCK inhibitors in LES and by protein kinase C (PKC) inhibitors in ESO. Contraction of LES and ESO induced by the PKC agonist 1,2-dioctanoylglycerol (DG) was unaffected by MLCK inhibitors. Caldesmon and calponin concentration-dependently inhibited ACh-induced contraction of ESO and not LES. In ESO, caldesmon antagonist GS17C reversed caldesmon- but not calponin-induced ACh inhibition. GS17C caused contraction of permeabilized ESO but had much less effect on LES. GS17C-induced contraction was not affected by MLCK inhibitors, suggesting that MLCK may not regulate caldesmon-mediated contraction. DG-induced contraction of ESO and LES was inhibited by caldesmon and calponinin, suggesting that these proteins may regulate PKC-dependent contraction. We conclude that calmodulin and MLCK play a role in ACh-induced LES contraction, whereas the classical MLCK may not be the major kinase responsible for contraction and phosphorylation of MLC in ESO. ESO contraction is PKC dependent. Caldesmon and/or calponin may play a role in PKC-dependent contraction.

Acetylcholine↗
PubMed2001

Production of catechol from benzoate by the wild strain Ralstonia species Ba-0323 and characterization of its catechol 1,2-dioxygenase.

Ralstonia sp. Ba-0323, a wild strain isolated from soil, produced catechol from benzoate and accumulated it outside the cells. The bacterium produced a maximal amount of catechol (1.6 mg/ml) from 3 mg/ml of sodium benzoate in a 20-h growing culture. The conversion rate of benzoate to catechol was 70% on a molar basis. The catechol production by the resting cells increased in the presence of glycerol, and the maximal amount of catechol produced from 3 mg/ml of sodium benzoate reached 1.9 mg/ml at the conversion rate of 83% after 8 h of incubation. Catechol 1,2-dioxygenase, which catalyzed the ring cleavage of catechol, was purified to homogeneity from a cell extract of Ralstonia sp. Ba-0323 growing on benzoate and characterized. The specific activity of the purified enzyme was much lower than those of the dioxygenases from other microorganisms reported. The Km for catechol of the purified enzyme was much higher than those of other dioxygenases. In addition, the NH2-terminal amino acid sequence of the enzyme was less similar to the other catechol 1,2-dioxygenases than they are to each other.

Amino Acid Sequence↗
PubMed2001

Caldesmon and smooth-muscle regulation.

Smooth muscles exist in the wall of hollow organs in our body and are responsible for controlling the flow of vital fluids that are essential for the normal function of the cardiovascular, respiratory, digestive, and reproductive systems. Many diseases, such as hypertension, asthma, indigestion, and premature birth, may attribute to malfunction of smooth-muscle contraction. It is therefore important to decipher how smooth-muscle contraction is regulated. This review attempts to give a brief overview of current understanding about the molecular mechanisms of smooth-muscle regulation and, in particular, to discuss possible roles of caldesmon in this regulatory process.

Actins↗
PubMed2001

Ultrasound examination of patellar tendon after harvest for anterior cruciate ligament reconstruction.

BACKGROUND AND PURPOSE: Reconstruction of ruptured anterior cruciate ligament (ACL) using the middle-third of the patellar tendon has become an established procedure. However, current studies of donor site morbidity have reported discrepant results. This study used ultrasound imaging to evaluate morphologic changes in the patellar tendon after harvest for ACL reconstruction. METHODS: Twenty-nine patients who had undergone successful ACL reconstruction with patellar tendon graft more than 1 year previously were enrolled in the study. Ultrasound imaging was used to compare the width, thickness, and tissue reaction of patellar tendons between the operated and contralateral sides. RESULTS: The operated side was 4.8% wider on average than the contralateral side (p < 0.05). The operated side was also 58.3% thicker on average (p < 0.0001), with irregular margins and heterogenous echogenecity. CONCLUSION: The donor site of the patellar tendon was significantly wider and thicker and was heterogenous when examined on sonogram more than 1 year postoperatively.

Adult↗
PubMed2001

[Coding region cDNA sequence cloning of rat neuroglobin gene, its polymorphism feature and tissue expression profile analysis].

The coding region cDNA sequence of rat neuroglobin (NGB) was obtained by RT-PCR technique using a degeneracy PCR primer pair based on previously reported cDNA sequence of human and mouse NGB gene. Result demonstrated that the coding region cDNA sequence of rat NGB gene is 456 bp in length, which could encode a protein of 151 amino acids. The rat NGB gene is highly homology with mouse (96%) and human (88%) NGB gene. However, several polymorphism sites were also detected in the rat NGB coding region: 113 t/c [L38P], 133 a/g [N45D], 388 a/g[R130G], 417 t/c. The cDNA sequence of rat NGB gene has been registered in GenBank under the accession number AF333245. Moreover, highly expression level of rat NGB in brain, liver, kidney, heart and skeletal muscle was detected by using multiple tissue RT-PCR technique, indicating the functional importance of this novel gene.

Amino Acid Sequence↗
PubMed2001

Lack of association between the Glu298Asp variant of the endothelial nitric oxide synthase gene and the risk of coronary artery disease among Taiwanese.

BACKGROUND AND PURPOSE: Endothelial nitric oxide synthase (eNOS) plays a key role in atherosclerosis, because its product, nitric oxide, possesses antiatherogenic properties. Recent reports of molecular genetic analysis have suggested that genetic polymorphisms of the eNOS gene may be associated with coronary artery disease (CAD) or myocardial infarction (MI). However, some studies have reported discrepant results. The aims of this study were to assess whether any association exists between the Glu298Asp variant of the eNOS gene and the risk of CAD and/or MI among Taiwanese. METHODS: The subjects included 218 CAD patients and the same number of age- and sex-matched control subjects from Taiwan. Subjects' DNA was extracted from their blood and genotypes were determined by polymerase chain reaction and restriction mapping using the restriction enzyme MboI. The alleleic and genotypic frequencies were analyzed. RESULTS: The frequencies of the eNOS genotypes were similar for CAD patients (GG:GT:TT = 81.7%:17.4%:0.9%) and controls (81.2%:17.4%:1.4%; p = 0.904). No evidence of difference was found in the frequency of the T allele between CAD patients (9.6%) and controls (10.1%; p = 0.822), or between MI patients (7.5%) and controls (p = 0.322). Subjects with the GT or TT genotype did not demonstrate an increased risk of CAD compared with those with a GG genotype (p = 0.89; OR = 0.98; 95% confidence interval, CI, 0.76-1.27) in multivariate logistic regression, or when different subgroups of age, sex, or risk factors were analyzed. CONCLUSIONS: In the present case-control study, we found no evidence of an association between the Glu298Asp variant of the eNOS gene and CAD/MI among Taiwanese.

Coronary Disease↗
PubMed2001

[Studies on saponin accumulative in regularities Panax notoginseng (Burk) F. H. Chen].

OBJECTIVE: To determine the optimal harvest time for P. notoginseng through studying the changes of saponin contents with growth periods. METHODS: P. notoginseng samples were collected from the experimental plot regularly, and then the contents of total saponin and some main single saponins were analyzed by HPLC. RESULTS: Total saponin contents decreased from April through July, and increased from August through December. CONCLUSION: The optimal harvest time is determined as from October through December, which corresponds to the traditional harvest time.

Ginsenosides↗
PubMed2000

[Effect of pantoprazole on non-variceal bleeding].

UNLABELLED: The treatment effect of 101 non-variceal bleeding(NVB) patients treated with pantoprazole was observed, and it was compared with 57 NVB patients treated with omeprazole. RESULTS: 87.1% of the patients in 48 h and 97% of the patients in 72 h with Pantoprazole bleeding-stopped. And the result was almost equal to omeprazole group. The side-effect of pantoprazole was few and slight. It is suggested that pantoprazole is effective and safe on treating NVB.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

Haptoglobin is a natural regulator of Langerhans cell function in the skin.

Langerhans cells (LC), the best-understood antigen presenting cells (APC) of the skin, are functionally plastic. Freshly obtained LC readily activate allogeneic T cells, but are incapable of activating autologous, naive T cells. When placed in culture in the presence of GM-CSF, LC up-regulate surface expression of class I and II MHC molecules along with co-stimulatory molecules, such as B7, CD40 and IL-12. This functional transformation enables the cells to activate naive, autologous T cells in vitro. It is paradoxical that intracutaneous administration of exogenous GM-CSF fails to induce intraepidermal LC to undergo functional transformation in situ. It has been reported that serum contains a factor that prevents fresh LC from undergoing functional transformation in culture, and the relevant serum factor has now been identified as haptoglobin (Hp), based on the following experimental results: (a) SDS-PAGE, amino acid sequencing, and mass spectrometric analyses of the inhibitory factor purified by high performance liquid chromatography (HPLC) from normal human serum revealed molecules completely homologous to Hp alpha-1 chain; (b) pure human Hp, but not serum depleted of Hp, inhibited fresh LC from acquiring the capacity to activate autologous T cells in vitro; (c) abundant Hp was detected in cytoplasmic compartments of fresh, but not cultured, LC. It was concluded that Hp, an acute phase protein, is a systemically-derived factor that prevents epidermal LC from spontaneously undergoing functional maturation in the skin. This novel property of Hp may be important in ameliorating or preventing certain T cell-dependent inflammatory skin diseases.

Animals↗