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Biomedical subjects

Ye Wang

Publications and source records attributed to Ye Wang.

At least 37 records · Page 2Linked to original sources
PubMed2006

[A study on the expression of HSP70 in endothelial cells pretreated with ethanol and fluid shear stress].

OBJECTIVE: To detect whether ethanol can affect the expression of HSP70 in endothelial cells under fluid shear stress. METHODS: Ethanol at different concentrations was added to the culture medium of endothelial cells, EA. Hy926, which was treated statically or under 1Pa fluid shear stress. After the incubation of 1 h, 2 h, 4 h and 6 h, the expression of HSP70 was detected by immunohistochemical method(SP). RESULTS: In the control group, the expression of HSP70 was negative under static state, while it was positive under 1Pa fluid shear stress lasting 4 h even without ethanol. No statistic difference was found between the 50 mg/dL ethanol group and the control group with the same treatment time of fluid shear stress. HSP70 expression was found under static state with 150 mg/dL ethanol after 4 h or 300 mg/dL ethanol after 2 h respectively. The expression increased greatly under 1Pa fluid shear stress in the same ethanol concentrations. CONCLUSION: Medium to high ethanol concentration in coordination with fluid shear stress can strongly stimulates the expression of HSP70 by a kinetic mechanism of time-dependent.

Cells, Cultured↗
PubMed2006

[The relationship of injury timing with the change of neuronal apoptosis and the expression of caspase-3 after brain contusion].

OBJECTIVE: To investigate and analyze the changes of neuronal-apoptosis and the expression of caspase-3 for finding out a new method of injury timing after brain contusion in human. METHODS: The tissue was stained by TUNEL for apoptosis and by immunohistochemistry for caspase-3. Image analysis technique was employed. RESULTS: The nerve cells stained positive by TUNEL and Caspase-3 immunohistochemistry were distributed in the penumbra and central area. Both these areas were in striking contrast with the distal area or those of control group. The positive staining was more prominente in penumbra area than in central area (P < 0.05). The changes of TUNEL staining and expression of Caspase-3 in penumbra area gradually increased with the survival period after injury; they were parallel to each other. There were linear relationships between the time of injury in 48 hours and the increase in the mean of integral optical density (IOD), the coefficient of correlation (r) being 0.93 and 0.69 for the two staining methods, and two linear regression formulae were induced, respectively. CONCLUSION: Observations on the increasing of neuronal apoptosis and Caspase-3 expression in relation with the survival period after injury could be utilized in the timing of brain contusion.

Adolescent↗
PubMed2006

[Advance of study on pathological mechanism of paraquat poisoning].

Paraquat which is used widely as a potent herbicide is poisonous, and its pathological mechanism is unclear. Studies show that it is so a strong oxidant that it can oxidate lipid and some enzyme, also, it can damage DNA directly or induce necrosis or apoptosis, which is marked in pulmonary. To offer new directions for treatment and studies on paraquat poisoning, this paper reviewed the foreign studies on mechanism of it.

Animals↗
PubMed2006

[Determination of ligustilide for quality assessment of Ligusticum chuanxiong].

OBJECTIVE: To assay ligustilide content in the herb of Szechwan Lovage Rhizome (Chuanxiong, CX), which is the dried rhizome of Ligusticum chuanxiong in order to assess the quality. METHOD: Ligustilide was quantitatively analyzed by high-performance liquid chromatography in 21 CX samples. An Alltima C18 column (4.6 mmx 150 mm, 5 microm) was used as the analytical column. The mobile phase consisted of water and acetonitrile (40:60). The flow rate was maintained at 1.0 mL x min(-1) with the column temperature at ambient conditions. The detection wavelength was set at 350 nm. RESULT: The average content of Z-ligustilide in 21 CX samples was found to be 7.40 +/- 3.54 mg x g(-1)(x +/- s, n = 21). Therefore,the content of Z-ligustilide in CX should not be less than 0.66% (calculated on the dried basis). CONCLUSION: The overall analytical procedure is rapid and accuracy which is considered suitable for the quantitative analysis of ligustilide in CX. The amount of ligustilide in CX samples collected from different cultivation areas was obviously different. However, a relatively higher content of ligustilide was generally found in the CX collected from its main cultivated areas.

4-Butyrolactone↗
PubMed2005

Computerized image analysis for quantitative neuronal phenotyping in zebrafish.

An integrated microscope image analysis pipeline is developed for automatic analysis and quantification of phenotypes in zebrafish with altered expression of Alzheimer's disease (AD)-linked genes. We hypothesize that a slight impairment of neuronal integrity in a large number of zebrafish carrying the mutant genotype can be detected through the computerized image analysis method. Key functionalities of our zebrafish image processing pipeline include quantification of neuron loss in zebrafish embryos due to knockdown of AD-linked genes, automatic detection of defective somites, and quantitative measurement of gene expression levels in zebrafish with altered expression of AD-linked genes or treatment with a chemical compound. These quantitative measurements enable the archival of analyzed results and relevant meta-data. The structured database is organized for statistical analysis and data modeling to better understand neuronal integrity and phenotypic changes of zebrafish under different perturbations. Our results show that the computerized analysis is comparable to manual counting with equivalent accuracy and improved efficacy and consistency. Development of such an automated data analysis pipeline represents a significant step forward to achieve accurate and reproducible quantification of neuronal phenotypes in large scale or high-throughput zebrafish imaging studies.

Animals↗
PubMed2005

Iron-catalyzed propylene epoxidation by nitrous oxide: studies on the effects of alkali metal salts.

SBA-15-supported iron catalysts with and without alkali metal salt modifications were studied for propylene oxidation by nitrous oxide. The reaction route could be dramatically changed from allylic oxidation to epoxidation by modification of the FeOx/SBA-15 catalyst with alkali metal salts. The KCl-1 wt % FeOx/SBA-15 (K/Fe = 5) catalyst exhibited the best catalytic performances for propylene epoxidation, over which ca. 50% propylene oxide selectivity could be gained at a 10% propylene conversion at 648 K. Characterizations with diffuse reflectance UV-Vis, XANES, and Raman spectroscopic techniques revealed that the modification with KCl increased the dispersion of the iron species and changed the local coordination of iron into a tetrahedral configuration on the inner surface of SBA-15. This tetrahedrally coordinated iron site, which was probably stabilized by potassium ions, was proposed to account for the epoxidation of propylene by nitrous oxide. At the same time, the reactivity of lattice oxygen was inhibited, and the acidity of the FeOx/SBA-15 was eliminated. These changes should also contribute to the increase in the selectivity to propylene oxide. The counteranions in the alkali metal salts exerted a significant influence on the catalytic behaviors probably via an electronic effect.

Journal Article↗
PubMed2005

Synthesis and antitumor activity of simplified ecteinascidin-saframycin analogs.

Two series of simplified analogs of the ecteinascidin-saframycin type alkaloids were prepared from l-DOPA. Their in vitro antitumor activity was tested against three human cancer cell lines (HCT-8 colon carcinoma, Bel-7402 liver carcinoma, and BGC-823 gastric carcinoma). Among these compounds, the ester analogs have stronger activities than those of amide analogs in general. Among them, 1-naphthalene carboxylate ester analog 31 has the strongest activity against BGC-823 cells.

Antineoplastic Agents↗
PubMed2005

The potential of phage display virions expressing malignant tumor specific antigen MAGE-A1 epitope in murine model.

The tumor specific antigen epitope melanoma antigen A1(161--169) (MAGE-A1(161--169)) was displayed on the major protein (p VIII) of the filamentous bacteriophage (fd). The immune responses of the phage display particles expressing MAGE-A1(161--169) in mice were studied. Using phage display particles as vaccine was effective in affording protection from tumor growth, inducing growth control of established tumors and prolonging survival of tumor-bearing mice. The hybrid phage particles elicited MAGE-A1(161--169) specific CTL responses, NK activity and DTH. Our results showed that the phage display particles might be a new vaccine candidate for tumor-associated antigen epitope in cancer immunotherapy.

Animals↗
PubMed2005

Enhanced green fluorescence protein tracks trichosanthin in human choriocarcinoma cells as a feasible and stable reporter.

Trichosanthin (TCS) is a ribosome-inactivating protein (RIP) which can inhibit the growth of human choriocarcinoma (JAR) cells. There are no clear mechanisms to discover the interaction pathway and cytotoxicity of TCS in JAR cells. In this paper, we showed the distribution and transport of endogenously expressed TCS in JAR cells. Enhanced Green Fluorescence Protein (EGFP), fused with TCS, was applied as a reporter to track the behavior of TCS in JAR cells. Firstly, we investigated the expression stability of EGFP and physiological effects on JAR cells. A stable cell line expressing EGFP was created, which could reproduce and express EGFP even if transplanted into nude mice. Based on the proved stability and feasibility of EGFP in cultured cells and in vivo, the fusion gene of EGFP and TCS was constructed and transfected into JAR cells by liposome. The fluorescence microscopy showed that TCS-EGFP fusion gene was expressed in JAR cells in 24 to 48 hours and the fluorescence spread in cytoplasm mainly and in nucleus partially, which could trace the distribution and transport of TCS-EGFP in JAR cells. Most of fluorescent cells died after 48 hours for the cytotoxicity of expressed TCS-EGFP. These results first reported a stable expression and tracing method by EGFP in JAR cells, and provided theoretical basis to apply TCS in cancer therapy.

Animals↗
PubMed2005

Determination of the essentiality of the eight cysteine residues of the NrtA protein for high-affinity nitrate transport and the generation of a functional cysteine-less transporter.

All eight cysteine residues, C90, C94, C143, C147, C219, C325, C367, and C431, present in transmembrane domains of the Aspergillus nidulans NrtA nitrate transporter protein were altered individually by site-specific mutagenesis. The results indicate that six residues, C90, C147, C219, C325, C367, and C431, are not required for nitrate transport. Although alterations of C94 and C143 are less well tolerated, these residues are not mandatory and their possible role is discussed. A series of constructs, all completely devoid of cysteine residues, was generated to permit future cysteine-scanning mutagenesis. The optimum cysteine-less combination was identified as C90A, C94A, C143A, C147T, C219S, C325S, C367S, and C431S. This mutant combination yielded transformant strains with up to 40% of wild-type nitrate transport activity. Furthermore, the K(m) value and the level of protein expression were found to be similar to those of the wild-type. This cysteine-less vector should allow us to investigate in detail potentially interesting NrtA amino acids (e.g. identified from homology comparisons) which may be involved in transport, by altering these singly to cysteine and studying such residues by thiol chemistry.

Anion Transport Proteins↗
PubMed2005

Trichomislin, a novel ribosome-inactivating protein, induces apoptosis that involves mitochondria and caspase-3.

Trichomislin, a novel ribosome-inactivating protein, was cloned from the genome of Trichosanthes kirilowii Maxim. The gene was recombined to prokaryotic expression vector and the protein was purified by cation-exchange chromatography. The secondary structure of trichomislin was measured by circular-dichroism analysis and the ratios of alpha-helices and beta-sheets were calculated. Trichomislin could inhibit the synthesis of protein in rabbit reticulocyte lysate systems and its reaction mechanism was to inactivate ribosome as an rRNA N-glycosidase. Antitumor analyses indicated trichomislin induced the apoptosis and inhibited the growth of choriocarcinoma cells. Further investigation showed that trichomislin could bind to and enter choriocarcinoma cells, and then increase the caspase-3 activity in a time-dependent manner. At the same time, the concentration of cytochrome c in cytosol increased while that in mitochondria decreased. These results suggested that trichomislin induced apoptosis by releasing cytochrome c from mitochondria which then triggered the caspase family member activation.

Amino Acid Sequence↗
PubMed2005

[The expression of Fas after fluid percussion brain injury in rats].

OBJECTIVE: To inquire into the pathologic diagnosis and the dating of injuries of light closed encephalon injury. METHODS: Wistar rats were hurt by fluid percussion, and were killed respectively at 15 min, 30 min, 1 h, 3 h, 6 h, 12 h, 1 d, 4 d, 7 d, and 14 d after injury. The expression of Fas in the cerebral cortex, thalamus, and hippocampi was detected by immunohistochemistry and the results were assessed by image analysis system. RESULTS: The results showed that the expression of Fas could be detected in thirty minutes after injury, and then it increased significantly in three hours, reached apex in twelve hours after injury, decreased gradually in four days after injury, and returned to normal in 14 days after injury. CONCLUSION: This research demonstrated that Fas-mediated apoptosis appeared not only around brain trauma but also in the brain tissue far away from the traumatic area. It indicted that Fas expression is a useful target for diagnosis of early brain injury and the regularity of Fas expression could be used as one of indications in deducing the time of brain injury.

Animals↗
PubMed2005

[Clinical application of magnifying colonoscopy in diagnosis and treatment of colorectal benign neoplastic lesions].

OBJECTIVE: To evaluate the clinical value of magnifying endoscopy in diagnosis and treatment of colorectal benign neoplastic lesions. METHODS: Seventy-eight colorectal lesions in 61 patients were examined with magnifying colonoscopy after indigo carmine dyeingìand pit pattern diagnosis was made for every lesion according to Kudos classification to differentiate neoplastic lesions from non-neoplastic lesions. The lesions were resected by endoscopic polypectomy and mucosectomy or surgical treatment. The diagnoses made by magnifying colonoscopy were compared with pathologic results. RESULTS: The diagnostic sensitivity of magnifying endoscopy for neoplastic lesions was 98.4% and specificity was 85.7%. The overall accuracy for adenoma and early colorectal cancer was 96.2%. 89.7% of adenomatous lesions were treated by endoscopic resection. CONCLUSION: The magnifying colonoscopy can provide instantaneous and accurate diagnosis of neoplastic lesions in colon and rectum,as well as minimally invasive treatment.

Adult↗
PubMed2005

[Expression of c-Fos in rats organs after electrical injury].

OBJECTIVE: To study the expression of c-fos in organs after rats electrified. METHODS: The brain, lung, heart, liver, spleen, kidney, muscle of electrified limb, and cutis of electrified limb of all experimental rats and those organs of control groups were dissected to detect the expression of c-fos by using immunohistochemistry staining, and the staining intensity were assessed by image analysis system. RESULTS: The expression of c-fos was observed in brain, heart, liver, lung, kidney and muscle in electrified directly group, the amount of expression reached peak at 2 h after electrified and decreasing at 8 h after electrified, and the expression showed faintness in electrified at the immediate after death group. The expressions of c-fos in spleen and cutis is negative in all groups. The expression of c-fos in all detected organs was negative in other rats that were electrified after death. CONCLUSION: c-fos can be regard as a target in identifying electrical injury, whether it formed at antemortem or postmortem.

Animals↗
PubMed2004

Two perfectly conserved arginine residues are required for substrate binding in a high-affinity nitrate transporter.

This study represents the first attempt to investigate the molecular mechanisms by which nitrate, an anion of significant ecological, agricultural, and medical importance, is transported into cells by high-affinity nitrate transporters. Two charged residues, R87 and R368, located within hydrophobic transmembrane domains 2 and 8, respectively, are conserved in all 52 high-affinity nitrate transporters sequenced thus far. Site-directed replacements of either of R87 or R368 residues by lysine were found to be tolerated, but such residue changes increased the K(m) for nitrate influx from micromolar to millimolar values. Seven other amino acid substitutions of R87 or R368 all led to loss of function and lack of growth on nitrate. No evidence was obtained of R87 or R368 forming a salt-bridge with conserved acidic residues. Remarkably, the phenotype of loss-of-function mutant R87T was found to be alleviated by an alteration to lysine of N459, present in the second copy of the nitrate signature (transmembrane domain 11), suggesting a structural or functional interplay between residues R87 and N459 in the three-dimensional NrtA protein structure. Failure of the potential reciprocal second site suppressor N168K (in the first nitrate signature copy of transmembrane domain 5) to revert R368T was observed. Taken with recent structural studies of other major facilitator superfamily proteins, the results suggest that R87 and R368 are involved in substrate binding and probably located in a region of the protein close to N459.

Anion Transport Proteins↗
PubMed2004

Iron-catalysed propylene epoxidation by nitrous oxide: dramatic shift of allylic oxidation to epoxidation by the modification with alkali metal salts.

A dramatic shift of allylic oxidation to epoxidation has been observed during the oxidation of propylene by N(2)O when the FeO(x)/SBA-15 catalyst is modified with alkali metal salts, and the roles of alkali metal salts are to suppress the reactivity of lattice oxygen and to induce an iron coordination structure effective for epoxidation with N(2)O.

Journal Article↗
PubMed2004

Nitrate reductase activity is required for nitrate uptake into fungal but not plant cells.

The ability to transport net nitrate was conferred upon transformant cells of the non-nitrate-assimilating yeast Pichia pastoris after the introduction of two genes, one encoding nitrate reductase and the other nitrate transport. It was observed that cells of this lower eukaryote transformed with the nitrate transporter gene alone failed to display net nitrate transport despite having the ability to produce the protein. In addition, loss-of-function nitrate reductase mutants isolated from several nitrate-assimilating fungi appeared to be unable to accumulate nitrate. Uptake assays using the tracer (13)NO(3)(-) showed that nitrate influx is negligible in cells of a nitrate reductase null mutant. In parallel studies using a higher eukaryotic plant, Arabidopsis thaliana, loss-of-function nitrate reductase strains homozygous for both NIA1 insertion and NIA2 deletion were found to have no detectable nitrate reductase mRNA or nitrate reductase activity but retained the ability to transport nitrate. The reasons for these fundamental differences in nitrate transport into the cells of representative members of these two eukaryotic kingdoms are discussed.

Arabidopsis↗