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Biomedical subjects

Qing Wang

Publications and source records attributed to Qing Wang.

At least 73 records · Page 4Linked to original sources
PubMed2006

[Novel mutations of potassium channel KCNQ1 S145L and KCNH2 Y475C genes in Chinese pedigrees of long QT syndrome].

OBJECTIVE: Hereditary long QT syndrome (LQTS) is a cardiac disorder characterized by prolongation of QT interval on electrocardiograms (ECGs) and syncope and sudden death caused by a specific multi-polymorphic ventricular tachyarrhythmia known as torsade de pointes. LQTS is caused by mutations in cardiac sodium channel gene SCN5A; potassium channel subunit genes KCNQ1, KCNH2, KCNE1, KCNE2, KCNJ2; calcium channel gene Cav2.1. and ankyrin-B gene ANK2. METHODS: We characterized 77 Chinese LQTS patients with clinical manifestations and mutations in the main LQTS genes, KCNQ1 and KCNH2 using PCR and sequence analysis. RESULTS: The spectrum of ST-T-wave patterns of 24 (31.2%) probands were considered as LQT1, 42 (54.5%) as LQT2 and 3 (3.9%) as LQT3. The remaining 8 (10.3%) could not be characterized. The average age for this population of LQTS patients was (27.6 +/- 16.4) years and the average QTc (561 +/- 70) ms, and the age of the first syncopal attack was (17.6 +/- 14.7) years. The triggering factors for cardiac events happening in these mutation carriers included physical exercise, emotional excitement and auditory irritation. We identified 4 KCNQ1 mutations and 7 KCNH2 mutations. Six of them were first identified with some data already shown. In this paper we showed the data of 6 other mutations. CONCLUSIONS: LQT2 is the most common type of LQTS in Chinese; 2 mutations of KCNQ1 and KCNH2 were first identified in this report; there are some differences between Chinese and North American or European LQTS patients in clinical characters and ECG.

Adolescent↗
PubMed2006

[Mutation of Thr704Met in SCN 4A causes normoKPP in a Chinese family].

Familial periodic paralysis (PP) is an autosomal dominant disorder characterized by episodic attacks of paralysis with different severity. We recruited a normoKPP family in Hubei China and evaluated genetic variations responsible for the disease. Linkage analysis was performed through microsatellite markers. Markers flanking SCN4A showed linkage evidence in the family. Sequencing of SCN4A exons revealed a substitution C2111T leading to the mutation Thr704Met in all affected family members, and was not observed in either unaffected members of the family or 100 unrelated individuals (controls). This mutation should be responsible for normoKPP in this family.

Adolescent↗
PubMed2006

The G401D mutation of OPA1 causes autosomal dominant optic atrophy and hearing loss in a Chinese family.

OBJECTIVE: To describe the clinical and genetic characteristics of a Chinese family affected with optic atrophy 1 (OPA1). METHODS: Linkage analysis and DNA sequencing as well as PCR/restriction fragment length polymorphism (RFLP) analysis were performed to identify the disease-causing mutation. RESULTS: A missense mutation, G401D in the OPA1 gene was identified, and the patients demonstrate inherited syndrome of optic atrophy and hearing loss. CONCLUSION: The present study demonstrates that a mutation in the OPA1 gene can cause optic atrophy in Chinese patients, and supports the notion that OPA1 mutation may lead to OPA1 combined with hearing loss.

Adult↗
PubMed2006

[China's environmental load and environmental depressurization analysis].

Based on material flow accounting and related indicators, an indicator, domestic environmental load, is formulated to measure the aggregate environmental pressure of a nation. Combining this indicator with the gross national product, an indicator for environmental efficiency is derived. The domestic environmental load is then decomposed into the rebound effect caused by economic growth and the depressurization effect induced by the efficiency increase. A case study was carried out for the Chinese economy to investigate its domestic environmental load, environmental efficiency and the rebound and depressurization effects. Results show that the environmental efficiency of the Chinese economy increased during the study period with an annual rate of 5.6%, indicating that a certain degree of depressurization was achieved. However, the rebound effect caused by economic growth was much greater than the depressurization effect induced by the efficiency increase,resulting in a considerable increase in the domestic environmental load (the annual growth rate was 3.8%). The Chinese economy is characterized by high environmental pressure and it is hard to achieve absolute depressurization.

China↗
PubMed2006

[A study of the bacteriophage-based assay for the detection of pyrazinamide resistance in Mycobacterium tuberculosis].

OBJECTIVE: To set up and evaluate the method of phage amplified biologically assay (PhaB) in rapid detection of pyrazinamide (PZA) resistance. METHODS: The PhaB assay was developed and applied in detecting PZA resistance in 108 clinical isolates of Mycobacterium tuberculosis and the results were compared with those of the absolute concentration method. The minimum inhibitory concentration (MIC) was detected for all discrepancy isolates. RESULTS: The results showed that the optimal detecting condition was pH 5.5, PZA 200 microg/ml and 48 h. Of the 108 strains of Mycobacterium tuberculosis, 28 strains were PZA-susceptible and 80 strains were PZA-resistant detected by PhaB; while 32 strains were PZA-susceptible and 76 strains were PZA-resistant by absolute concentration method. Twenty-eight of the 108 strains were PZA-susceptible and 71 were PZA-resistant by the two methods. The concordant isolates of determination of PZA resistance were 99 by the two methods and the concordance rates was 91.7%. There were 9 strains in discordant isolates, of which 7 were the same with MIC method and gene chip in drug susceptibility. If the results of absolute concentration method was the gold standard, the sensitivity, specificity, positive and negative predictive values, as well as accuracy of PhaB assay was 94.7%, 84.8%, 93.4%, 87.5% and 91.7% respectively. CONCLUSION: The PhaB assay can be used as a rapid screening method for detection of drug susceptibility of PZA in clinical isolates of Mycobacterium tuberculosis.

Antitubercular Agents↗
PubMed2006

[The roles of AC/A ratio and other ocular motor parameters in the induction of late-onset myopia].

OBJECTIVE: This study was to explore ocular motor parameters (accommodation and convergence) in late myopia onset and development. METHODS: Eleven Emm (emmetrope), 14 S.M. (stable late-onset myopia), and 9 P.M. (progressing late-onset myopia) were include in this study. Phoria at distance and near, positive and negative relative accommodation (NRA/PRA), accommodative convergence and accommodation response were measured. RESULTS: Response AC/A ratio of P.M. was higher than that of Emm or S.M. (P < 0.05); But statistically AC/A ratio was not significant difference (P > 0.05). Accommodation response (3.00 D) of Emm was higher than P.M and S.M (P < 0.05). There was significant difference in phoria in near between LOM and Emm, but none in that of distance. There was no significant difference in NRA. However, PRA of LOM was lower than that of the Emm (P < 0.05). CONCLUSIONS: Ocular motor parameters are important in LOM onset and development. Response AC/A ratio (not calculated AC/A ratio) is one of key parameters among them, Response AC/A ratio is the highest in P.M, which indicates out of focus of retinal image in the developing LOM.

Accommodation, Ocular↗
PubMed2006

[Experimental study on the effects of jujingwan on oligospermia].

OBJECTIVE: To investigate the effects of Jujingwan on the spermatozoal ultrastructure and apoptosis of germ cells in oligospermia patients. METHODS: We treated 50 oligospermia patients with Jujingwan and observed the spermatozoal ultrastructure, the apoptosis of germ cells and the changes in the DNA ploidy proportion of spermatogenic cells by electron microscopy and FCM before the treatment and 3, 6, 9 and 12 months after it. RESULTS: Jujingwan increased sperm acrosome base density 6 months after the treatment and remarkably improved the integrity of acrosome membrane 12 months after it, with no obvious pathological changes in the nuclei and tails. Three months after the treatment, cell debris and apoptotic cells decreased significantly as compared with pre-treatment (P < 0. 05) , and very significantly 12 months after the treatment (P <0. 01). The proportion of haploid spermatozoa increased very significantly (P <0.01) , and the lost primary spermatocytes decreased significantly (P <0. 05) compared with pre-treatment. CONCLUSION: Jujingwan can increase the density of sperm acrosome base and improve the pathological changes of acrosome membrane in oligospermia patients; it can improve the activity of acrosome enzyme and the integrity of acrosome membrane, decrease the apoptosis rate of germ cells and sperm and increase the percentage of haploid spermatozoa; it can also reduce the percentage of apoptotic bodies and diploid sperm cells. It is indicated that Jujingwan can inhibit the apoptosis of germ cells and sperm and improve spermatogenesis in oligospermia patients.

Acrosome↗
PubMed2005

Experimental investigation of an inhomogeneous loss and its influence on multiwavelength fiber lasers.

Inhomogeneous loss generated by multimode laser linewidth broadening in an optical fiber is experimentally studied. With this mechanism, multiwavelength lasing is achieved by use of either fiber Raman gain or erbium-doped fiber gain. Through various pump powers and optical filter bandwidths, the relationship between inhomogeneous loss and the performance of a multiwavelength fiber laser is studied, and a physical explanation is provided.

Journal Article↗
PubMed2005

Multifunctional roles of the conserved Arg residues in the second region of homology of p97/valosin-containing protein.

The 97-kDa molecular chaperone valosin-containing protein (VCP) belongs to a highly conserved AAA family and forms a hexameric structure that is essential for its biological functions. The AAA domain contains highly conserved motifs, the Walker A, Walker B, and the second region of homology (SRH). Although Walker A and B motifs mediate ATP binding and hydrolysis, respectively, the function of the SRH in VCP is not clear. We examined the significance of the SRH in VCP, especially the conserved Arg(359) and Arg(362) in the first AAA domain, D1 and Arg(635) and Arg(638) in the second AAA domain, D2. We show that Arg(359) and Arg(362) in D1 are critical for maintaining the hexameric structure and the ability to bind the polyubiquitin chains. Although the rest of the tested SRH mutants retain the hexameric structure, all of them exhibit severely reduced ATPase activity. Tryptophan fluorescence analysis showed that all of the tested mutants can bind to ATP or ADP. Thus, the reduced ATPase activity likely results from the hampered communications among protomers during hydrolysis. Moreover, when the ATPase-defective mutant R635A or R638A is mixed with the Walker A mutant of D2, the ATPase activity is partially restored, suggesting that Arg(635) and Arg(638) can stimulate the ATPase activity of the neighboring protomer. Interestingly, mutation of Arg(359) and Arg(362) uncouples the inhibitory effect of p47, a VCP co-factor, on the ATPase activity of VCP. Therefore, the Arg residues allow D1 to take on a specific conformation that is required for substrate binding and co-factor communications. Taken together, these results demonstrate that the conserved Arg residues in the SRH of both D1 and D2 play critical roles in communicating the conformational changes required for ATP hydrolysis, and SRH in D1 also contributes to substrate binding and co-factor communications.

Adenosine Triphosphatases↗
PubMed2005

Activation of bone morphogenetic protein-6 gene transcription in MCF-7 cells by estrogen.

BACKGROUND: Bone morphogenetic protein-6 (BMP-6) is closely correlated with tumor differentiation and skeletal metastasis. Estrogen is considered as a stimulant for the initiation and promotion of breast cancer. Previous studies demonstrated that 17beta-estadiol (E2) can selectively increase the expression of BMP-6. This experiment is designed to detect the molecular mechanism of estrogen activating BMP-6 gene transcription in human estrogen receptor positive (ER+) breast cancer cell line MCF-7. METHODS: After the treatment of MCF-7 cells with E2 at different concentrations (10(-11) mol/L, 10(-9) mol/L, 10(-7) mol/L), the BMP-6 expression level was examined through real-time polymerase chain reaction. Through restriction enzyme digestion, human BMP-6 1.2 kb long promoter, BMP-6 0.7 kb long promoter was cloned into pGL-3 basic vector; after the treatment with 10(-7) mol/L E2, luciferase activities of the two promoters were detected. Site-directed mutagenesis was performed to obtain the mutant forms of estrogen response element half-site (1/2 ERE) element and Sp1 sites in the BMP-6 promoter, the activities of these mutant form promoters were detected following the methods mentioned above. Chromatin immunoprecipitation (ChIP) assay was also used to confirm the binding of estrogen receptor alpha (ERalpha) on BMP-6 promoter in the presence of E2. RESULTS: E2 dose dependently increased BMP-6 mRNA expression in human ER+ breast cancer cell line MCF-7. At a dose of 10(-7) mol/L E2, human BMP-6 1.2 kb promoter activity was increased by 90% compared with the control group treated with ethanol (P < 0.05). Both the 1/2 ERE response element mutant form and the Sp1 site mutant form of the BMP-6 promoter abolished the activation of the BMP-6 promoter's response to E2. Through ChIP assay, the binding of ERalpha on 1/2 ERE response element in BMP-6 promoter was further validated. CONCLUSION: Estrogen induces BMP-6 expression in human ER+ breast cancer cell line MCF-7 through its receptor ERalpha binding on 1/2 ERE element in the BMP-6 promoter.

Bone Morphogenetic Protein 6↗
PubMed2005

Efficient light harvesting by using green Zn-porphyrin-sensitized nanocrystalline TiO2 films.

A series of novel zinc metalloporphyrins, cyano-3-(2'-(5',10',15',20'-tetraphenylporphyrinato zinc(II))yl)-acrylic acid (Zn-3), 3-(trans-2'-(5',10',15',20'-tetraphenylporphyrinato zinc(II))yl)-acrylic acid (Zn-5), 2-cyano-5-(2'-(5',10',15',20'-tetraphenylporphyrinato zinc(II))yl)-penta-2,4-dienoic acid (Zn-8), 4-(trans-2'-(2' '-(5' ',10' ',15' ',20' '-tetraphenylporphyrinato zinc(II))yl)ethen-1'-yl))-1,2-benzenedicarboxylic acid (Zn-11), and 2-cyano-3-[4'-(trans-2' '-(2' ''-(5' '',10' '',15' '',20' ''-tetraphenylporphyrinato zinc(II))yl) ethen-1' '-yl)-phenyl]-acrylic acid (Zn-13) were synthesized and characterized by using various spectroscopic techniques. Density functional theory (DFT) and time-dependent DFT (TDDFT) calculations show that key molecular orbitals (MOs) of porphyrins Zn-5 and Zn-3 are stabilized and extended out onto the substituent by pi-conjugation, causing enhancement and red shifts of visible transitions and increasing the possibility of electron transfer from the substituent. The porphyrins were investigated for conversion of sunlight into electricity by constructing dye-sensitized TiO(2) solar cells using an I(-)/I(3)(-) electrolyte. The cells yield close to 85% incident photon-to-current efficiencies (IPCEs), and under standard AM 1.5 sunlight, the Zn-3-sensitized solar cell demonstrates a short circuit photocurrent density of 13.0 +/- 0.5 mA/cm(2), an open-circuit voltage of 610 +/- 50 mV, and a fill factor of 0.70 +/- 0.03. This corresponds to an overall conversion efficiency of 5.6%, making it the most efficient porphyrin-sensitized solar cell reported to date.

Journal Article↗
PubMed2005

Anthocyanins induce cholesterol efflux from mouse peritoneal macrophages: the role of the peroxisome proliferator-activated receptor {gamma}-liver X receptor {alpha}-ABCA1 pathway.

It is widely accepted that stimulation of reverse cholesterol transport, the efflux of excess cholesterol from peripheral tissues and transferring it to the liver for biliary excretion, is becoming an important component in reducing excess cholesterol deposition in atherosclerotic plaques. The ATP-binding cassette transporter has been identified as a key regulator of macrophage cholesterol efflux and apoAI-mediated reverse cholesterol transport. In vivo studies have documented anthocyanins, a large group of naturally phenolic compounds rich in plants, possess substantial capacities in improving plasma cholesterol levels. In this study, we investigated the potential role of anthocyanins in modulating cholesterol efflux from mouse peritoneal macrophages and macrophage-derived foam cells and the possible molecular mechanism linking ABCA1 to cholesterol efflux. Incubation of the mouse peritoneal macrophages and macrophage-derived foam cells with cyanidin-3-O-beta-glucoside and peonidin-3-O-beta-glucoside led to dose-dependent (1-100 microM) induction in cholesterol efflux and ABCA1 mRNA expression, and this effect could be blocked by the ABCA1 inhibitor 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid, disodium salt, and a general inhibitor of gene transcription actinomycin D. Treatment of the macrophages with anthocyanins also activated peroxisome proliferator-activated receptor gamma, liver X receptor alpha mRNA expression, and their mediated gene expression. Addition of geranylgeranyl pyrophosphate ammonium salt or GW9662 markedly inhibited the anthocyanin-induced increase of ABCA1 gene expression and apoAI-mediated cholesterol efflux. These data demonstrated that anthocyanin induces cholesterol efflux from mouse peritoneal macrophages and macrophage-derived foam cells and that stimulation of cholesterol efflux by anthocyanin is mediated, at least in part, by peroxisome proliferator-activated receptor gamma-liver X receptor alpha-ABCA1 signaling pathway activation.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed2005

Potassium supplementation reduces cardiac and renal hypertrophy independent of blood pressure in DOCA/salt mice.

We have demonstrated previously that deoxycorticosterone acetate (DOCA)/salt induces cardiac hypertrophy and left ventricular dysfunction independent of blood pressure (BP) in 1-renin gene mice. Because these mice also develop hypokalemia and metabolic alkalosis caused by mineralocorticoid excess, we investigated whether correcting hypokalemia by dietary potassium supplementation would prevent the DOCA/salt-induced cardiac hypertrophy, cardiac dysfunction, and electrocardiographic changes in normotensive, 1-renin gene and hypertensive, 2-renin gene mice. All mice were studied after 5 weeks of DOCA and salt administration. Potassium was given by adding 0.4 or 0.6% KCl to the drinking water. Our results show that correction of hypokalemia and metabolic alkalosis prevents cardiac hypertrophy and normalizes cardiac function without affecting BP in normotensive, 1-renin gene mice. In hypertensive, 2-renin gene mice, potassium supplementation induces a significant decrease in BP. The decrease in BP and correction of kalemia are associated with a significant but partial correction of cardiac hypertrophy. In both group of mice, electrocardiographic alterations were measured after administration of DOCA/salt, which could be corrected by potassium supplementation. Thus, these results show that correction of hypokalemia and metabolic alkalosis does prevent the development of cardiac hypertrophy and normalizes cardiac function independent of BP in normotensive, 1-renin gene mice that receive excess mineralocorticoid and salt. In 2-renin gene, hypertensive mice, potassium supplementation also prevents the development of cardiac hypertrophy, but the effect cannot be separated from the decrease in BP.

Animals↗
PubMed2005

Electrochemical impedance spectroscopic analysis of dye-sensitized solar cells.

Electrochemical impedance spectroscopy (EIS) has been performed to investigate electronic and ionic processes in dye-sensitized solar cells (DSC). A theoretical model has been elaborated, to interpret the frequency response of the device. The high-frequency feature is attributed to the charge transfer at the counter electrode while the response in the intermediate-frequency region is associated with the electron transport in the mesoscopic TiO2 film and the back reaction at the TiO2/electrolyte interface. The low-frequency region reflects the diffusion in the electrolyte. Using an appropriate equivalent circuit, the electron transport rate and electron lifetime in the mesoscopic film have been derived, which agree with the values derived from transient photocurrent and photovoltage measurements. The EIS measurements show that DSC performance variations under prolonged thermal aging result mainly from the decrease in the lifetime of the conduction band electron in the TiO2 film.

Journal Article↗
PubMed2005

The rationale for deltanoids in therapy for myeloid leukemia: role of KSR-MAPK-C/EBP pathway.

The evidence for the promising potential for derivatives of Vitamin D (deltanoids) in the treatment of myeloid leukemias is increasing, but currently is not matched by the understanding of the precise mechanisms by which these anti-neoplastic effects are achieved. Unlike solid tumors in which growth retardation by deltanoids appears to result from inhibition of cell proliferation and the promotion of cell death by apoptosis, control of myeloid leukemia proliferation by deltanoids results from the induction of differentiation of the immature myelo-monocytic cells towards functional monocytic cells. We present here the accumulating evidence that a pathway that is initiated by deltanoid activation of Vitamin D receptor (VDR) and leads to monocytic differentiation of human myeloblastic HL60 cells, includes the MEK-ERK and JNK mitogen-activated protein kinases (MAPKs), their positive and negative regulators and a downstream effector C/EBPbeta. As in other cells, the abundance of VDR protein increases shortly after an exposure of HL60 cells to 1alpha,25-dihydroxyvitamin D(3) (1alpha,25(OH)(2) D(3)). Other early events include a parallel upregulation of kinase suppressor of Ras (KSR-1) and the activation of the ERK MAPK pathway and data suggest that KSR-1 acts to amplify the signal provided by low concentrations of 1alpha,25(OH)(2) D(3). Maintenance of monocytic differentiation may be enhanced by JNK, but diminished by p38, MAPK signaling. Downstream, one of the targets of these pathways is C/EBPbeta, which can directly interact with the promoter for CD14, a gene characteristically expressed in monocytes. Importantly, in freshly obtained acute myeloid leukemia (AML)-M2 cells exposed to PRI-2191, a novel deltanoid with a modified side chain, upregulation of C/EBPbeta paralleled the induction of monocytic differentiation. These data provide a basis for the hypothesis that deltanoid-induced upregulation of C/EBPbeta bypasses the block to granulocytic differentiation in myeloid leukemia cells by redirecting the cells to monocytic differentiation.

Antineoplastic Agents↗
PubMed2005

Angiotensin II-mediated phenotypic cardiomyocyte remodeling leads to age-dependent cardiac dysfunction and failure.

Chronic elevation of plasma angiotensin II (Ang II) is detrimental to the heart. In addition to its hemodynamic effects, Ang II exerts cardiotrophic actions that contribute to cardiomyocyte remodeling. However, it remains to be clarified whether these direct actions of Ang II are sufficient to cause contractile dysfunction and heart failure in the absence of altered hemodynamic conditions. In this study, we used TG1306/1R (TG) mice that develop Ang II-mediated cardiac hypertrophy in absence of elevated blood pressure to investigate the phenotypic changes in cardiomyocytes during the adaptive response to chronic cardiac-specific endogenous Ang II stimulation. A 94-week longitudinal study demonstrated that TG mice develop dilated cardiomyopathy with aging and exhibit a significant increase in mortality compared with wild-type (WT) mice. Cardiac hypertrophy in TG mice is associated with cardiomyocyte hypertrophy (15 to 20 weeks: length +20%; 35 to 40 weeks: length +10%, width +15%) but not collagen deposition. In vivo analysis of cardiac function revealed age-dependent systolic and diastolic dysfunction in TG mice (approximately 45% reduction in dP/dtmax and dP/dtmin at 50 to 60 weeks of age compared with WT). Analysis of isolated cardiomyocyte isotonic shortening showed impaired contractility in TG cardiomyocytes (30% to 40% decrease in rates of shortening and lengthening). In TG hearts, chronic Ang II exposure induced downregulation of the sarcoplasmic reticulum calcium pump (SERCA2) and diminution of Ca2+ transients, indicative of an underlying disturbance in calcium homeostasis. In conclusion, chronic Ang II myocardial stimulation without hemodynamic overload is sufficient to produce cardiomyocyte and cardiac dysfunction culminating in heart failure.

Aging↗