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Biomedical subjects

Yan Wang

Publications and source records attributed to Yan Wang.

At least 181 records · Page 10Linked to original sources
PubMed2006

[Clinical observation on Qingling Dingxuan Decoction in treating vertigo cause by insufficient blood-supply of ventebrobasilar artery].

OBJECTIVE: To observe the therapeutic effect of Qingling Dingxuan Decoction (QDD) on vertigo caused by insufficient blood-supply of ventebrobasilar artery (IBVA). METHODS: Thirty-nine patients were divided into the flunarizine group (n=19) and the QDD group (n=20) treated with respective medicine on the base of routine treatment with Chinese and Western medicine. The clinical efficacy and recurrent rate were observed and compared. RESULTS: Compared with those in the flunarizine group, clinical curative effect was better, recurrent rate lower, symptom score higher, hemorheological parameters and transcranial doppler indexes were improved more significant in the QDD group (P < 0.01 or P < 0.05). CONCLUSION: QDD had obvious therapeutic effect on IBVA. Improvement of microcirculation and reduction of blood viscosity may be one of the therapeutical mechanisms.

Adult↗
PubMed2006

Effects of iron and phosphorus on Microcystis physiological reactions.

OBJECTIVE: To observe the effects of iron and phosphorus on Microcystis physiological reactions. METHODS: The experimental conditions were chosen as the light dark cycles of 16 h 8 h, 12 h 12 h, and 8 h 16 h. The cell change of morphology and life history, cell number, cell color, and cell area of Microcystis were analyzed quantitatively. According to the resource competition and Monod equation, Microcystis kinetics of phosphorus and iron were also examined. RESULTS: The longer light time caused more special cell division, slower growth rate, and easier change of bigger cell area. The color of alga was changed from green to brown. Ks and micromax of phosphorus absorption were 0.0352 mircomol x L(-l) and 0.493 d(-1), respectively. Those of iron absorption were 0.00323 micromol x L(-1) and 0.483 d(-1). CONCLUSION: Microcystis bloom is more dominant than other algae.

Iron↗
PubMed2006

[Accuracy analysis of pulse oximetry based on dynamic spectroscopy].

The pulse oximeter used to measure patients oxygen saturation non-invasively and continuously, has numerous applications in clinic care. The pulse oximetry measurement combines two basic methods, spectrophotometry and photoplethysmography (PPG). The red light and the infrared light are exposed to the ear lobe, finger or other tissue with fluctuation of artery blood, and then detected. The amplitude ratio of the photoplethysmography waveform of red light and infrared light varies with the oxygen saturation of blood. The measuring principle of the pulse oximeter is based on traditional test method, its accuracy is not gratifying due to various factors influencing the measurement result, such as the principle, measuring condition, and individual discrepancy. In the present paper a new pulse oximetry based on dynamic spectroscopy is introduced, It can promote the accuracy of the pulse oximeter evidently. The dynamic spectroscopy method is able to eliminate the interference of individual discrepancy and measuring condition in principle. This new method can eliminate the measurement error of pulse oximetry theoretically.

Humans↗
PubMed2006

[Effects of immunosuppressants on cytokine expressions after repair for nerve injury in a rat model].

OBJECTIVE: To explore effects of several immunosuppressants on cytokine expressions after repair for a sciatic nerve injury in a rat model. METHODS: The sciatic nerves of 42 rats were cut and sutured end-to-end. After operation, the rats were divided into 6 groups. Group A (n = 9) was served as a control with no medicines given. Group B (n= 9) was given methylprednisolone 20 mg/(kg x d) for 2 days. Groups C(n= 9) and D(n = 3) were given FK506 1 mg/(kg - d) for 2 weeks and 4 weeks respectively, and were given the same doses of methylprednisolone as Group B. Groups E and F were given CsA 2 mg/(kg - d) for 2 weeks and 4 weeks respectively, and were given the same doses of methylprednisolone as Group B. The sciatic nerves were sampled at 1, 2 and 4 weeks postoperatively. And immunohistochemistry stainings of interleukin 1beta (IL-1beta), tumor necrosis factor alpha (TNF-alpha), interferon gamma(IFN-gamma) and macrophage migration inhibitory factor(MIF) were performed. The staining results were compared and analyzed. RESULTS: The expression peaks of IL-1beta and IFN-gamma were found at the 1st week postoperatively in Group A. Then, the expression decreased rapidly at the 2nd week and disappeared at the 4th week. As for TNF-a and MIF, they were only found to have a low expression until the 1st week in Group A. In groups C-F, the expression peaks of IL-1beta, TNF-alpha and IFN-gamma were found at the 2nd week, while the expression peak of MIF was still at the 1st week, and the expression of all the cytokines extended to the 4th week. The expressions of these cytokines in Group B were just between the expression levels of Group A and Groups C-F. CONCLUSION: Immunosuppressants can delay the expression peaks and significantly extend the expression time of IL-1beta, TNF-alpha, IFN-gamma and MIF after repair for a sciatic nerve injury in a rat model.

Animals↗
PubMed2005

Molecular identification and functional characterization of a temperature-sensitive transient receptor potential channel (TRPM8) from canine.

TRPM8 belongs to the family of transient receptor potential channels and is activated by cooling and cooling agents, such as icilin and menthol. It is expressed in a subset of sensory neurons and is thought to be involved in thermosensation. Here, we report the cloning and functional characterization of canine TRPM8 (cTRPM8). cTRPM8 shares 95.1%, 94.1%, and 93.9% protein sequence identity with human, rat and mouse TRPM8, respectively. Similar to these mammalian orthologs, cTRPM8 was activated by menthol and icilin with strong outward rectification and little cation selectivity. Menthol and icilin also caused calcium-dependent desensitization. Interestingly, cTRPM8 was activated at <17 degrees C, a temperature threshold lower than that reported for the other orthologs. At 22 degrees C, the EC(50) for activation of cTRPM8 expressed in HEK293 cells by icilin and menthol was 0.06 and 4.3 microM determined by Fluorometric Imaging Plate Reader (FLIPR) and 0.4 and 85 microM by patch clamp, respectively. Mustard oil also activated cTRPM8 (FLIPR EC(50) = 490 microM). Menthol activation was more potent at +60 mV than at -60 mV (EC(50) = 53 and 124 microM, respectively, in Xenopus ooctyes). Icilin-, menthol- and mustard oil-induced intracellular Ca(2+) increases were similarly blocked by N-(4-tertiarybutyl-phenyl)-4-(3-chloropyridin-2-yl) tetrahydropyrazine-1(2H)-carboxamide (BCTC) with IC(50) = 2.3, 2.8 and 1.8 microM, respectively. Cooling-activated current was also inhibited by BCTC. Extracellular calcium blocked cTRPM8 in a concentration- and voltage-dependent manner (half maximal blocking [Ca(2+)] = 1.6 mM at -100 mV). These results constitute the first study of cTRPM8 and support the idea that cTRPM8 functions as a transducer of cold stimuli in vivo.

Action Potentials↗
PubMed2005

RNA interference targeting of A1 receptor-overexpressing breast carcinoma cells leads to diminished rates of cell proliferation and induction of apoptosis.

To determine if A1 adenosine receptors mediate breast tumorigenesis, we evaluated A1 receptor expression in human tumor cell lines and human primary breast tumor tissues using both quantitative RT-PCR and Western blot analysis. A1 receptor mRNA expression is upregulated in all breast tumor cell lines examined (n=7) compared to normal mammary epithelial cells/cell lines (n=3) as determined by quantitative RT-PCR analysis. Western blot analysis indicates that protein expression of A1 adenosine receptor is higher in 15 (62.5%) of 24 human primary breast tumor tissues than in matched normal breast tissue. To explore its cellular function, the A1 adenosine receptor was depleted by small interfering RNA (siRNA) in MDA-MB-468 human breast tumor cells. Depletion of A1 receptors in MDA-MB-468 breast tumor cells attenuated both cell growth and cell proliferation as measured by cell number counts and [(14)C]-thymidine incorporation, respectively. Cell cycle analysis indicated that depletion of A1 receptors by siRNA impairs G(1) checkpoint, leading to marked accumulation of cells in G(2)/M phase, in agreement with the inhibitory effect on cell proliferation. Further supporting this finding, synchronization studies of Hela cells in various cell cycle phases suggest that A1 receptor expression is suppressed in G(2)/M cells and depletion of A1 receptor expression by siRNA produced differential expression of several key cell cycle regulators, i.e., accumulation of the cyclin-dependent kinase inhibitor p27 with concomitant reduction of CDK4 and cyclin E proteins. In addition to the impact on cell cycle progression, depletion of A1 receptors by siRNA results in substantial cell death and apoptosis as determined by FACS analysis and annexin V staining method. Together these findings suggest that the A1 adenosine receptor may contribute to tumor cell growth and survival in breast tumor cells.

Apoptosis↗
PubMed2005

Cap1p is involved in multiple pathways of oxidative stress response in Candida albicans.

Cap1p, a transcription factor in Candida albicans, is thought to participate in oxidative stress tolerance, but the pathways involved are still unclear. The study was designed to reveal the possible pathways by examining changes in the transcription profile after H2O2 treatment with both the cap1-deleted strain CJD21 and its parental strain CAI4 using microarray analysis. Of the identified 89 genes differentially expressed in CAI4 after exposure to H2O2, 76 genes were in a Cap1p-dependent expression pattern. We have shown that Cap1p is involved in the oxidative stress response in C. albicans via multiple pathways, including the cellular antioxidant defense system (e.g., thioredoxin reductase, glutathione reductase, glutathione S-transferase), carbohydrate metabolism and energy metabolism (e.g., glucose-6-phosphate dehydrogenase, transaldolase, glyoxalase I, NADH-dependent flavin oxidoreductase), protein degradation (e.g., 26S proteasome regulatory subunit, ubiquitin-specific protease), ATP-dependent RNA helicase (e.g., DEAD box protein ATP-dependent RNA helicase), and resistance pathways (e.g., multidrug resistance protein, ABC transporter essential for cadmium resistance). Real-time reverse transcription-PCR analysis further confirmed the results of microarray. Collectively, this study provides new insight into the biological functions of Cap1p in oxidative stress response.

Basic-Leucine Zipper Transcription Factors↗
PubMed2005

High-performance SPME/AP MALDI system for high-throughput sampling and determination of peptides.

This paper presents the performance characteristics for a new multiplexed solid-phase microextraction/atmospheric pressure matrix-assisted laser desorption/ionization (SPME/AP MALDI) source configuration for a hybrid quadrupole-linear ion trap instrument. The results demonstrate that thorough optimization of parameters such as SPME coating material, optics configurations, extraction solvents, and fiber capacity provides dramatic sensitivity improvements (>1000x) over previous reports in the literature. The multiplexed SPME plate is capable of simultaneous extraction from 16 different wells on a multiwell plate, eliminating the need for extensive sample preparation. Subfemtomole sensitivity is demonstrated for peptide standards and protein digests with run-run reproducibility ranging from approximately 13 to 31%. This high-performance SPME/AP MALDI system shows potential for high-throughput extraction from biological samples.

Angiotensin I↗
PubMed2005

New skeletal 3D polymeric inorganic cluster [W4S16Cu16Cl16]n with Cu in mixed-valence states: solid-state synthesis, crystal structure, and third-order nonlinear optical properties.

A new 3D polymeric inorganic cluster with Cu in mixed-valence states was synthesized by the solid-state reaction of (NH4)2WS4, S8, CuCl, and Et4NCl; S8 may be regarded as the oxidizing agent converting Cu(I) to Cu(II) and causing the polymerization of [WS4]2-. The third-order nonlinear optical (NLO) properties are determined, and the results show that the cluster exhibits both large NLO absorptive and strong refractive behaviors.

Journal Article↗
PubMed2005

Identification of surface-exposed components of MOMP of Chlamydia trachomatis serovar F.

The identification of surface-exposed components of the major outer membrane protein (MOMP) of Chlamydia is critical for modeling its three-dimensional structure, as well as for understanding the role of MOMP in the pathogenesis of Chlamydia-related diseases. MOMP contains four variable domains (VDs). In this study, VDII and VDIV of Chlamydia trachomatis serovar F were proven to be surface-located by immuno-dot blot assay using monoclonal antibodies (MAbs). Two proteases, trypsin and endoproteinase Glu-C, were applied to digest the intact elementary body of serovar F under native conditions to reveal the surface-located amino acids. The resulting peptides were separated by SDS-PAGE and probed with MAbs against these VDs. N-terminal amino acid sequencing revealed: (1) The Glu-C cleavage sites were located within VDI (at Glu61) and VDIII (at Glu225); (2) the trypsin cleavage sites were found at Lys79 in VDI and at Lys224 in VDIII. The tryptic peptides were then isolated by HPLC and analyzed with a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer and a quadrupole-orthogonal-TOF mass spectrometer coupled with a capillary liquid chromatograph. Masses and fragmentation patterns that correlated to the peptides cleaved from VDI and VDIII regions, and C-terminal peptides Ser333-Arg358 and Ser333-Lys350 were observed. This result demonstrated that these regions are surface-exposed. Data derived from comparison of nonreduced outer membrane complex proteolytic fragments with their reduced fractions revealed that Cys26, 29, 33, 116, 208, and 337 were involved in disulfide bonds, and Cys26 and 337, and 116 and 208 were paired. Based on these data, a new two-dimensional model is proposed.

Amino Acid Sequence↗
PubMed2005

High resolution genomic analysis of sporadic breast cancer using array-based comparative genomic hybridization.

INTRODUCTION: Genomic aberrations in the form of subchromosomal DNA copy number changes are a hallmark of epithelial cancers, including breast cancer. The goal of the present study was to analyze such aberrations in breast cancer at high resolution. METHODS: We employed high-resolution array comparative genomic hybridization with 4,134 bacterial artificial chromosomes that cover the genome at 0.9 megabase resolution to analyze 47 primary breast tumors and 18 breast cancer cell lines. RESULTS: Common amplicons included 8q24.3 (amplified in 79% of tumors, with 5/47 exhibiting high level amplification), 1q32.1 and 16p13.3 (amplified in 66% and 57% of tumors, respectively). Moreover, we found several positive correlations between specific amplicons from different chromosomes, suggesting the existence of cooperating genetic loci. Queried by gene, the most frequently amplified kinase was PTK2 (79% of tumors), whereas the most frequently lost kinase was PTK2B (hemizygous loss in 34% of tumors). Amplification of ERBB2 as measured by comparative genomic hybridization (CGH) correlated closely with ERBB2 DNA and RNA levels measured by quantitative PCR as well as with ERBB2 protein levels. The overall frequency of recurrent losses was lower, with no region lost in more than 50% of tumors; the most frequently lost tumor suppressor gene was RB1 (hemizygous loss in 26% of tumors). Finally, we find that specific copy number changes in cell lines closely mimicked those in primary tumors, with an overall Pearson correlation coefficient of 0.843 for gains and 0.734 for losses. CONCLUSION: High resolution CGH analysis of breast cancer reveals several regions where DNA copy number is commonly gained or lost, that non-random correlations between specific amplicons exist, and that specific genetic alterations are maintained in breast cancer cell lines despite repeat passage in tissue culture. These observations suggest that genes within these regions are critical to the malignant phenotype and may thus serve as future therapeutic targets.

Breast Neoplasms↗
PubMed2005

Gene expression profiling differentiates germ cell tumors from other cancers and defines subtype-specific signatures.

Germ cell tumors (GCTs) of the testis are the predominant cancer among young men. We analyzed gene expression profiles of 50 GCTs of various subtypes, and we compared them with 443 other common malignant tumors of epithelial, mesenchymal, and lymphoid origins. Significant differences in gene expression were found among major histological subtypes of GCTs, and between them and other malignancies. We identified 511 genes, belonging to several critical functional groups such as cell cycle progression, cell proliferation, and apoptosis, to be significantly differentially expressed in GCTs compared with other tumor types. Sixty-five genes were sufficient for the construction of a GCT class predictor of high predictive accuracy (100% training set, 96% test set), which might be useful in the diagnosis of tumors of unknown primary origin. Previously described diagnostic and prognostic markers were found to be expressed by the appropriate GCT subtype (AFP, POU5F1, POV1, CCND2, and KIT). Several additional differentially expressed genes were identified in teratomas (EGR1 and MMP7), yolk sac tumors (PTPN13 and FN1), and seminomas (NR6A1, DPPA4, and IRX1). Dynamic computation of interaction networks and mapping to existing pathways knowledge databases revealed a potential role of EGR1 in p21-induced cell cycle arrest and intrinsic chemotherapy resistance of mature teratomas.

Chromosomes, Human↗
PubMed2005

[Clinicopathologic features and treatment of ductal carcinoma in situ of the breast].

OBJECTIVE: To investigate the clinicopathologic features of and appropriate treatment of ductal carcinoma in situ of the breast (DCIS). METHODS: The clinical and pathologic data of 41 cases of DCIS, aged 52.7 (30-82), 15 of which were diagnosed as with ductal carcinoma in situ with microinvasion (DCIS-MI) and of which 18 were in the Van Nuys grade I, 13 in the grade II, and 10 in the grade III, were collected and analyzed. Immunohistochemical analysis was performed to examine the expressions of estrogen receptor (ER), progesterone receptor (PR), proliferating cell nuclear antigen (PCNA), P53 and C-erbB-2. RESULTS: Microinvasion was correlated with the histologic categories (chi(2) = 4.60, P < 0.05) and tumor size (chi(2) = 9.78, P < 0.05) significantly. The expression rates of ER, PR, PCNA, P53, and C-erbB-2 were 68.3%, 65.9%, 63.4%, 26.8%, and 46.3%, respectively. There was no significant difference in the expression of the biologic markers between the patients with DCIS and those with DCIS-MI. The expression levels of ER, P53, and C-erbB-2 were correlated with the histologic categories significantly (chi(2) = 11.45, 11.97, 4.38, P < 0.05). CONCLUSION: The Van Nuys histologic classification accords with the requirement of clinical treatment and prognosis. The patients with DCIS should undergo individualized treatment.

Adult↗
PubMed2005

Effects of bezafibrate on the expression of endothelial nitric oxide synthase gene and its mechanisms in cultured bovine endothelial cells.

OBJECTIVE: Peroxisome proliferator-activated receptors alpha (PPARalpha) is a target gene for atherosclerosis and cardiovascular diseases. However, effects of PPARalpha on endothelial nitric oxide synthase (eNOS) remain unknown. We investigated the eNOS regulation by bezafibrate, a ligand of PPARalpha, and involved signaling pathways. METHODS AND RESULTS: Firstly, in cultured bovine aorta endothelial cells (BAEC), bezafibrate significantly upregulated eNOS at protein, mRNA levels and NO production, respectively, in a concentration-dependent fashion (50-200muM). Next, the effects of bezafibrate on signal pathways and eNOS mRNA stability in BAEC were investigated. Results showed that bezafibrate induced phosphorylation of MAPK. Inhibitors of PPARalpha, PI3 kinase and MAPK, respectively, markedly attenuate bezafibrate-induced upregulation of eNOS. Bezafibrate incubation increased eNOS mRNA half-life, activated eNOS promoter, enhanced phosphorylation of eNOS ser-1179 site, and decreased phosphorylation of eNOS thr-497 site via activating ERK and Akt. CONCLUSIONS: Bezafibrate can upregulate eNOS expression, enhance phosphorylation of eNOS ser-1179, increase NO production and transcription level and stability of eNOS mRNA through pathway dependent of PPARalpha and nongenomic effects mediated by MAPK and PI3K pathways. Hence, PPARalpha ligands exert direct benefits on vessel endothelial functions through an increase in eNOS expression level and phosphorylation of eNOS ser-1179. This mechanism provides additional anti-atherosclerotic and anti-hypertension benefits of bezafibrate in addition of lipid-lowering effects.

Animals↗
PubMed2005

Contrasting single-trial ERPs between experimental manipulations: improving differentiability by blind source separation.

Contrasting event-related potentials (ERPs) generated under different experimental conditions and inferring differential brain responses is widely practiced in cognitive neuroscience research. Traditionally, these contrasts and subsequent inferences have proceeded directly from ERPs measured at the scalp. For certain tasks, it is not unusual that ERPs from a subset of channels are given particular emphasis in data analysis, such as the channels displaying the maximum peak amplitude in regions of interest ("best sensors") or channels showing the largest averaged ERP waveform differences. With the aid of a blind source separation (BSS) algorithm, second-order blind identification (SOBI), which has been recently validated for its ability to recover correlated neuronal sources, we show that single-trial ERPs from previously validated neuronal sources were more distinguishable among different experimental manipulations than the single-trial ERPs measured at the comparable "best sensors". This suggests that by using validated SOBI-recovered neuronal sources, ERP researchers can improve the ability to detect differences in neuronal responses induced by experimental manipulations. Critically, our observations were made at the level of single trials, as opposed to the averaged ERP. Therefore, our conclusions are particularly relevant to phenomena involving trial-to-trial changes in brain activation, for example, rapid induction of brain plasticity and perceptual learning, as well as to the development of brain-computer interfaces. Similar advantages would also apply to analogous situations with magnetoencephalography (MEG).

Adult↗
PubMed2005

Studies on zinc bioavailability from a representative diet in Chinese urban women of childbearing age using a double label stable isotope technique.

The objectives of the study were to determine dietary zinc bioavailability by using a double label stable isotope technique, and to identify the zinc content and levels of some possible factors which may affect zinc utilization in a typical representative Chinese urban diet. Twenty urban women of childbearing age were fed a diet extrinsically labeled with 67Zn and received intravenous (i.v.) injections of 70Zn. Fecal monitoring, urine monitoring and chemical balance technique were used simultaneously for comparisons. Isotopic enrichment in feces and urine after oral and i.v. administration of stable zinc isotopes was measured to determine the ways of zinc absorption. The mean (+/-SD) zinc intake from the representative Chinese diet was 10.22+/-0.80 mg/day, which is lower than the reference nutrient intake (RNI) level (11.5 mg/day), and mainly came from the subsidiary foods (63%). The mean dietary Fe/Zn weight was 1.1+/-0.1. The phytate/zinc molar ratio in the diet was about 3:1. The phytic acidxCa/zinc molar ratio in the diet was about 45:1. The apparent and true absorption rates of 67Zn were 36.2+/-9.7% and 38.2+/-10.1%, respectively, which were higher than the apparent absorption determined by balance technique (29.7+/-10.6%). The mean fractional absorption (FA) determined in urine was 35.7+/-13.3. In conclusion, the subsidiary food is the main source of dietary zinc in this typical diet. The extrinsic labeling technique by use of stable isotopes was more reliable and accurate to determine zinc absorption. Moreover, the double isotopic tracer ratio (DITR) technique applied to urine samples was a more practical and valuable way to evaluate zinc absorption than other methods. It can be speculated that iron and phytic acid might not be the main inhibitors in the representative Chinese diet.

Absorption↗
PubMed2005

[Identification of up-regulated genes induced by angiotensin II in cardiac fibroblasts].

To identify up-regulated genes in adult rat cardiac fibroblasts (CF) induced by angiotensin II (Ang II), suppression subtractive hybridization (SSH) was performed between the CF stimulated by Ang II (tester) and unstimulated CF (driver) to generate subtractive cDNA library. The library was screened with dot blots hybridization to further verify the differentially expressed cDNA clones. Partial positive clones (19 up-regulated genes) were sequenced and BLAST analyzed. Twelve up-regulated genes related to extracellular matrix, cell cycle, intracellular signal transduction, cell cytoskeleton, cell metabolism and 7 new expressed sequence tags (EST) were acquired (GenBank accession number: CN382808, CN382809, CN382810, CN382811, CN382812, CN382813, CN382814). Our data reveal that SSH is a powerful technique of high sensitivity for the detection and cloning of up-regulated genes expressed in CF induced by Ang II, which may be helpful to clarify the mechanism of cardiac remodeling.

Angiotensin II↗