30 results on '"Zhang WM"'
Search Results
2. AT-HOOK MOTIF NUCLEAR LOCALIZED (AHL) proteins of ancient origin radiate new functions.
- Author
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Zhang WM, Cheng XZ, Fang D, and Cao J
- Subjects
- Cell Nucleus genetics, Cell Nucleus metabolism, Plant Breeding, Plant Proteins genetics, Plant Proteins metabolism, AT-Hook Motifs genetics, Arabidopsis Proteins genetics
- Abstract
AHL (AT-HOOK MOTIF NUCLEAR LOCALIZED) protein is an important transcription factor in plants that regulates a wide range of biological process. It is considered to have evolved from an independent PPC domain in prokaryotes to a complete protein in modern plants. AT-hook motif and PPC conserved domains are the main functional domains of AHL. Since the discovery of AHL, their evolution and function have been continuously studied. The AHL gene family has been identified in multiple species and the functions of several members of the gene family have been studied. Here, we summarize the evolution and structural characteristics of AHL genes, and emphasize their biological functions. This review will provide a basis for further functional study and crop breeding., (Copyright © 2022 Elsevier B.V. All rights reserved.)
- Published
- 2022
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3. Asperorydines N-P, three new cyclopiazonic acid alkaloids from the marine-derived fungus Aspergillus flavus SCSIO F025.
- Author
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Xiang Y, Zeng Q, Mai ZM, Chen YC, Shi XF, Chen XY, Zhong WM, Wei XY, Zhang WM, Zhang S, and Wang FZ
- Subjects
- Alkaloids isolation & purification, Anti-Bacterial Agents isolation & purification, Antineoplastic Agents isolation & purification, Aquatic Organisms chemistry, Bacillus drug effects, Cell Line, Tumor, China, Escherichia coli drug effects, Geologic Sediments microbiology, Humans, Indoles isolation & purification, Methicillin-Resistant Staphylococcus aureus drug effects, Microbial Sensitivity Tests, Micrococcus drug effects, Molecular Structure, Seawater microbiology, Alkaloids pharmacology, Anti-Bacterial Agents pharmacology, Antineoplastic Agents pharmacology, Aspergillus flavus chemistry, Indoles pharmacology
- Abstract
Three new tricyclic cyclopiazonic acid (CPA) related alkaloids asperorydines N-P (1-3), together with six known compounds (4-9) were isolated and characterized from the fungus Aspergillus flavus SCSIO F025 derived from the deep-sea sediments of South China Sea. The structures including absolute configurations of 1-3 were deduced from spectroscopic data, X-ray diffraction analysis, and electronic circular dichroism (ECD). All compounds were evaluated for the antioxidative activities against DPPH, cytotoxic activities against four tumor cell lines (SF-268, HepG-2, MCF-7, and A549), and antimicrobial activities. Compound 9 showed significant radical scavenging activities against DPPH with an IC
50 value of 62.23 μM and broad-spectrum cytotoxicities against four tumor cell lines with IC50 values ranging from 24.38 to 48.28 μM. Furthermore, compounds 4-9 exhibited weak antimicrobial activities against E scherichia coli, and compound 9 also showed antibacterial activity against Bacillus thuringiensis, Micrococcus lutea, Staphylococcus aureus, Bacillus subtilis, Methicillin resistant Staphylococcus aureus., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
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4. Effect of drying treatment on the structural characterizations and physicochemical properties of starch from canistel (Lucuma nervosa A.DC).
- Author
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He R, Shang WT, Pan YG, Xiang D, Yun YH, and Zhang WM
- Subjects
- Carbohydrate Conformation, Desiccation, Molecular Structure, Spectroscopy, Fourier Transform Infrared, X-Ray Diffraction, Sapotaceae chemistry, Starch chemistry
- Abstract
This work investigated the effects of hot air drying pretreatment (HAD), freeze drying pretreatment (FD) and vacuum drying pretreatment (VD) on the physicochemical properties and structural characterizations of starch isolated from canistels. X-ray diffraction displayed that the starches separated from canistel by different drying pretreatments showed a typical A-type crystal structure. The SEM image showed that cracks and debris appeared on the surface of HVD and VD particles. The molecular structure of starches obtained by different drying pretreatments was studied using Fourier infrared and solid state
13 C CP/MAS NMR analysis. The results indicated that vacuum drying pretreatment could promote the formation of the double helix of starch granules, and hot air drying and freeze drying destroyed the ordered structure of starch granules. These structural changed to affect the physicochemical properties of starch granules. The study of different drying pretreatments to separate starches provided practical value for drying pretreatments. Furthermore, the current study affords information for canistel starches cultivated in China that would be convenient for commercial applications., Competing Interests: Declaration of competing interest The author of this article declares that there is no conflict of interest related to this article., (Copyright © 2020. Published by Elsevier B.V.)- Published
- 2021
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5. Homo-aro-cholestane, furostane and spirostane saponins from the tubers of Ophiopogon japonicus.
- Author
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Wang L, Jiang XL, Zhang WM, Li F, Khan AA, Liu X, Yu K, and Wang MK
- Subjects
- Antineoplastic Agents, Phytogenic chemistry, Antineoplastic Agents, Phytogenic pharmacology, Cholestanes chemistry, Cholestanes pharmacology, Drug Screening Assays, Antitumor, Drugs, Chinese Herbal chemistry, Drugs, Chinese Herbal pharmacology, Molecular Structure, Saponins chemistry, Saponins pharmacology, Stereoisomerism, Antineoplastic Agents, Phytogenic isolation & purification, Cholestanes isolation & purification, Drugs, Chinese Herbal isolation & purification, Ophiopogon chemistry, Plant Tubers chemistry, Saponins isolation & purification
- Abstract
Phytochemical investigation of the tubers of Ophiopogon japonicus led to the isolation of five previously undescribed steroidal saponins, ophiojaponins A-E, together with twelve known ones. The structures of these isolated compounds were elucidated by detailed spectroscopic analyses and chemical methods. Ophiojaponins A-C are rare naturally occurring C
29 steroidal glycosides possessing a homo-cholestane skeleton with an aromatized ring E. Ruscogenin 1-O-α-L-rhamnopyranosyl-(1 → 2)-4-O-sulfo-β-D-fucopyranosido-3-O-β-D-glucopyranoside was isolated as single component and its full spectroscopic data was reported for the first time. The isolated steroidal saponins were evaluated for their cytotoxicities against two human tumor cell lines MG-63 and SNU387. Among them, five known spirostane-type glycosides showed cytotoxic activity against both MG-63 and SNU387 cell lines with IC50 values ranging from 0.76 to 27.0 μM., (Copyright © 2017 Elsevier Ltd. All rights reserved.)- Published
- 2017
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6. Three new highly-oxygenated metabolites from the endophytic fungus Cytospora rhizophorae A761.
- Author
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Liu HX, Tan HB, Liu Y, Chen YC, Li SN, Sun ZH, Li HH, Qiu SX, and Zhang WM
- Subjects
- Antineoplastic Agents isolation & purification, Benzophenones chemistry, Benzophenones isolation & purification, Cell Line, Tumor, Endophytes chemistry, Humans, Molecular Structure, Morinda microbiology, Naphthalenes chemistry, Naphthalenes isolation & purification, Phenols isolation & purification, Pyrones chemistry, Pyrones isolation & purification, Antineoplastic Agents chemistry, Ascomycota chemistry, Phenols chemistry
- Abstract
Cytosporaphenones A-C, one new polyhydric benzophenone and two new naphtopyrone derivatives, along with eight known ones, were isolated from Cytospora rhizophorae, an endophytic fungus from Morinda officinalis. Their structures were fully characterized by means of detailed spectroscopic analysis and X-ray single crystal diffraction. To our knowledge, the three new compounds were the most highly oxygenated metabolites of their families discovered in nature. Moreover, all of the compounds were evaluated for in vitro cytotoxic activities against MCF-7, NCI-H460, HepG-2 and SF-268 tumor cell lines, and the new compound 1 exhibited weak growth inhibitory activity against the tumor cell lines MCF-7 and HepG-2 with IC
50 values of 70 and 60μM, respectively., (Copyright © 2016 Elsevier B.V. All rights reserved.)- Published
- 2017
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7. Acylphloroglucinols from the leaves of Callistemon viminalis.
- Author
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Liu HX, Chen YC, Liu Y, Zhang WM, Wu JW, Tan HB, and Qiu SX
- Subjects
- Anti-Infective Agents chemistry, Anti-Infective Agents isolation & purification, Antineoplastic Agents, Phytogenic chemistry, Antineoplastic Agents, Phytogenic isolation & purification, Cell Line, Tumor, Humans, Molecular Structure, Phloroglucinol isolation & purification, Plant Extracts chemistry, Myrtaceae chemistry, Phloroglucinol chemistry, Plant Leaves chemistry
- Abstract
A phytochemical study on the leaves of Callistemon viminalis, a widely distributed ornamental and medicinal plant of agricultural importance in China, resulted in the isolation of eleven acylphloroglucinols, including six new ones named callistenones F-K (1-6), as well as five known congeners. Their structures were fully characterized using spectral data interpretation for the new structures and compared to published data for the known ones. All the isolated compounds were evaluated for in vitro antimicrobial activity and growth inhibitory activity against four tumor cell lines (MCF-7, NCI-H460, SF-268 and HepG-2)., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
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8. Potential Effects of Interleukins on the Pathogenesis of Systemic Onset Juvenile Idiopathic Arthritis.
- Author
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Xu LY, Zhang WM, Xia M, and Cao LF
- Subjects
- Adolescent, Arthritis, Juvenile pathology, C-Reactive Protein, Case-Control Studies, Child, Child, Preschool, Enzyme-Linked Immunosorbent Assay, Female, Humans, Male, Pain Measurement, Arthritis, Juvenile blood, Arthritis, Juvenile etiology, Cytokines blood
- Abstract
Background: To analyze the correlation of cytokines with clinical inflammatory indexes in systemic onset juvenile idiopathic arthritis (SOJIA)., Methods: A total of 30 active SOJIAs, 30 remission SOJIAs, and 20 normal controls were enrolled. The clinical inflammatory indexes such as tender joints counts, swelling joints counts, C-reactive protein, erythrocyte sedimentation rate, visual analogue scale (VAS), and disease activity score 28 (DAS28) were detected. The serum cytokines interleukin (IL)-17, IL-6, IL-21, interferon (IFN)-γ, and IL-4 levels were determined with enzyme-linked immunosorbent assay method. The correlation coefficients between these cytokines and two clinical indexes (VAS and DAS28) in the active SOJIA group were calculated with the Spearman's method., Results: The serum IL-17 and IL-6 levels in active SOJIA group were significantly increased compared with those in the remission SOJIA group and control group (p < 0.05), and the serum IL-21, IFN-γ, and IL-4 levels showed no obvious difference. In the active SOJIA group, the Spearman coefficients between IL-17 and DAS28, IL-17 and IL-6, IL-6 and DAS28, and between IL-17 and VAS were 0.686 (p = 0.000), 0.833 (p = 0.000), 0.633 (p = 0.000), and 0.524 (p = 0.003), respectively. There was no correlation between cytokines of IL-21, IFN-γ, and IL-4 and the clinical indexes of DAS28 and VAS. Furthermore, in the other two groups, none of the five cytokines exhibited an association with DAS28 or VAS., Conclusion: IL-6 and IL-17 were significantly correlated with DAS28 and VAS, and they might be considered as therapeutic targets for the treatment of SOJIA., (Copyright © 2016. Published by Elsevier B.V.)
- Published
- 2016
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9. Cytotoxic cochlioquinone derivatives from the endophytic fungus Bipolaris sorokiniana derived from Pogostemon cablin.
- Author
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Wang M, Sun ZH, Chen YC, Liu HX, Li HH, Tan GH, Li SN, Guo XL, and Zhang WM
- Subjects
- Antineoplastic Agents isolation & purification, Benzoquinones isolation & purification, Cell Line, Tumor drug effects, Humans, Indolequinones isolation & purification, Molecular Structure, Structure-Activity Relationship, Antineoplastic Agents chemistry, Ascomycota chemistry, Benzoquinones chemistry, Indolequinones chemistry, Lamiaceae microbiology
- Abstract
Chemical investigation of the liquid culture of the endophytic fungus Bipolaris sorokiniana A606, which was isolated from the medicinal plant Pogostemon cablin resulted in the isolation of four new cytotoxic compounds, named isocochlioquinones D-E (1-2) and cochlioquinones G-H (3-4), along with five known cochlioquinone analogues (5-9). Their structures were determined on the basis of extensive spectroscopic analysis. Isocochlioquinone D (1) possessed a rare benzothiazin-3-one moiety and cochlioquinone G (3) was the first example of cochlioquinones bearing an indole-4,7-dione fragment. All of the isolates (1-9) were evaluated for their cytotoxic activities against MCF-7, NCI-H460, SF-268 and HepG-2 tumor cell lines by the sulforhodamine B (SRB) assay. Compounds 4 and 6-9, featuring a cochlioquinone core, exhibited potent cytotoxicities in vitro against the four tumor cell lines, and a preliminary structure-activity relationship of these compounds was also discussed., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
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10. Enhancement of Gleditsia sinensis gum rheological properties with pressure cell treatment in semi-solid state.
- Author
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Zhou ZY, Zhang WA, Duan JF, Zhang WM, Sun DF, and Jiang JX
- Subjects
- Molecular Weight, Solubility, Viscosity, Gleditsia chemistry, Mechanical Phenomena, Plant Gums chemistry, Rheology
- Abstract
The apparent viscosity, molecular weight, and molecular weight distribution are important physical properties that determine the functional properties of galactomannan gum. Gleditsia sinensis gum (GSG) in semi-solid state was pressure cell treated over a range of temperature (30-110 °C) under nitrogen maintained at a pressure of 1.0-4.0 MPa. Physicochemical properties of GSG samples both before and after the pressure cell treatment were characterized. These include measurements of rheological properties by LVDV-III Ultra Rheometer, molecular weight and radius of gyration by light scattering, and changes in surface morphology by scanning electron microscopy. GSG had the highest apparent viscosity at a treatment temperature of 30 °C; further increase in temperature led to decrease in apparent viscosity. The apparent viscosity of GSG can be efficiently improved at room temperature and low pressure. The process of pressure cell treatment of GSG in semi-solid state could be industrialized for enhancement of rheological properties of galactomannan gum., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2016
- Full Text
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11. House dust mite extract induces growth factor expression in nasal mucosa by activating the PI3K/Akt/HIF-1α pathway.
- Author
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Chen X, Li YY, Zhang WQ, Zhang WM, and Zhou H
- Subjects
- Animals, Male, Mice, Mice, Inbred BALB C, Nasal Mucosa drug effects, Proto-Oncogene Proteins c-akt immunology, Signal Transduction drug effects, Signal Transduction immunology, Hypoxia-Inducible Factor 1, alpha Subunit immunology, Intercellular Signaling Peptides and Proteins immunology, Nasal Mucosa immunology, Phosphatidylinositol 3-Kinases immunology, Pyroglyphidae immunology, Rhinitis, Allergic immunology
- Abstract
Growing evidence suggests that hypoxia-inducible factor-α (HIF-1α) plays an important role in the progression of allergic airway inflammation and remodeling. However, the biochemical mechanisms leading to the activation of HIF-1α and the effects of HIF-1α on the expression of growth factors, including vascular endothelial growth factor (VEGF), transforming growth factor-β1 (TGF-β1), and fibroblast growth factor-2 (FGF-2), in allergic nasal inflammation are not clear. We examined the relationship between HIF-1α activation and production of VEGF, TGF-β1, and FGF-2 in primary cultured nasal epithelial cells (NECs) after stimulation with house dust mite (HDM) extract. Moreover, we evaluated the importance of phosphoinositide3-kinase(PI3K)/Akt signaling in HDM-induced production of these growth factors in vitro and in the nasal mucosa of a murine model of allergic rhinitis (AR). Our results indicate HDM extract induced the expression of VEGF, TGF-β1, and FGF-2 by activating the PI3K/Akt/HIF-1α pathway in human primary cultured NECs and in the nasal mucosa of a murine model. HIF-1α regulated the expression of VEGF, TGF-β1, and FGF-2 in the nasal mucosa through direct and indirect pathways, which suggested that targeting the HIF-1α pathway could be a novel therapeutic approach for reducing nasal airway inflammation and remodeling in AR., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2016
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12. Determination of kurarinone in rat plasma by UPLC-MS/MS.
- Author
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Zhang WM, Li RF, Qiu JF, Zhang ZY, Wang HB, Bian L, and Lei JH
- Subjects
- Administration, Intravenous, Animals, Drug Stability, Flavonoids administration & dosage, Flavonoids chemistry, Flavonoids pharmacokinetics, Linear Models, Male, Rats, Rats, Sprague-Dawley, Reproducibility of Results, Sensitivity and Specificity, Chromatography, High Pressure Liquid methods, Flavonoids blood, Tandem Mass Spectrometry methods
- Abstract
A sensitive and rapid ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed to determine kurarinone in rat plasma using chlorzoxazone as the internal standard (IS). Sample preparation was accomplished through a liquid-liquid extraction procedure with ethyl acetate to 0.2 mL plasma sample. The analyte and IS were separated on an Acquity UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with the mobile phase of acetonitrile and 1% formic acid in water with gradient elution at a flow rate of 0.40 mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer equipped with electrospray ionization (ESI) by multiple reactions monitoring (MRM) of the transitions at m/z 437.0→301.2 for kurarinone and m/z 168.1→132.1 for IS. The linearity of this method was found to be within the concentration range of 20-2000 ng/mL with a lower limit of quantification of 20 ng/mL. Only 3.0 min was needed for an analytical run. The matrix effect was 94.7-107.2% for kurarinone. The intra- and inter-day precision (RSD%) were less than 8.2% and accuracy (RE%) was within ±9.0%. The recovery ranged from 77.3% to 85.6%. Kurarinone was sufficiently stable under all relevant analytical conditions. The method was also successfully applied to the pharmacokinetic study of kurarinone in rats., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
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13. UPLC-MS/MS method for determination of avicularin in rat plasma and its application to a pharmacokinetic study.
- Author
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Zhang WM, Li RF, Sun M, Hu DM, Qiu JF, and Yan YH
- Subjects
- Animals, Drug Stability, Flavonoids chemistry, Flavonoids pharmacokinetics, Limit of Detection, Liquid-Liquid Extraction, Male, Rats, Rats, Sprague-Dawley, Reproducibility of Results, Chromatography, High Pressure Liquid methods, Flavonoids blood, Tandem Mass Spectrometry methods
- Abstract
A rapid, sensitive and selective ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed and validated for the determination and pharmacokinetic investigation of avicularin in rat plasma. Sample preparation was accomplished through a simple one-step deproteinization procedure with 0.2 mL of acetonitrile-methanol (9:1, v/v) to a 0.1 mL plasma sample. Plasma samples were separated by UPLC on an Acquity UPLC BEH C18 column using a mobile phase consisting of acetonitrile-0.1% formic acid in water with gradient elution. The total run time was 1.60 min and the elution of avicularin was at 1.20 min. The detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction-monitoring (MRM) mode using the respective transitions m/z 434.1→301.3 for avicularin and m/z 237.2→194.3 for carbamazepine (IS), respectively. The calibration curve was linear over the range of 10-3000 ng/mL with a lower limit of quantitation (LLOQ) of 10 ng/mL. Mean recovery of avicularin in plasma was in the range of 84.2-89.5%. Intra-day and inter-day precision were both <12%. This method was successfully applied in pharmacokinetic study after intravenous administration of 5.0mg/kg avicularin in rats., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
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14. CTHRC1 acts as a prognostic factor and promotes invasiveness of gastrointestinal stromal tumors by activating Wnt/PCP-Rho signaling.
- Author
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Ma MZ, Zhuang C, Yang XM, Zhang ZZ, Ma H, Zhang WM, You H, Qin W, Gu J, Yang S, Cao H, and Zhang ZG
- Subjects
- Benzamides therapeutic use, Cell Movement, Extracellular Matrix Proteins genetics, Female, Gastrointestinal Neoplasms drug therapy, Gastrointestinal Neoplasms metabolism, Gastrointestinal Neoplasms mortality, Gastrointestinal Stromal Tumors drug therapy, Gastrointestinal Stromal Tumors metabolism, Gastrointestinal Stromal Tumors mortality, Gene Expression Regulation, Neoplastic, Humans, Imatinib Mesylate, Male, Middle Aged, Piperazines therapeutic use, Prognosis, Proto-Oncogene Proteins metabolism, Pyrimidines therapeutic use, Wnt Proteins metabolism, Wnt-5a Protein, rac1 GTP-Binding Protein metabolism, Extracellular Matrix Proteins metabolism, Gastrointestinal Neoplasms pathology, Gastrointestinal Stromal Tumors pathology, Wnt Signaling Pathway, rhoA GTP-Binding Protein metabolism
- Abstract
Gastrointestinal stromal tumors (GISTs) are the major gastrointestinal mesenchymal tumors with a variable malignancy ranging from a curable disorder to highly malignant sarcomas. Metastasis and recurrence are the main causes of death in GIST patients. To further explore the mechanism of metastasis and to more accurately estimate the recurrence risk of GISTs after surgery, the clinical significance and functional role of collagen triple helix repeat containing-1 (CTHRC1) in GIST were investigated. We found that CTHRC1 expression was gradually elevated as the risk grade of NIH classification increased, and was closely correlated with disease-free survival and overall survival in 412 GIST patients. In vitro experiments showed that recombinant CTHRC1 protein promoted the migration and invasion capacities of primary GIST cells. A luciferase reporter assay and pull down assay demonstrated that recombinant CTHRC1 protein activated noncanonical Wnt/PCP-Rho signaling but inhibited canonical Wnt signaling. The pro-motility effect of CTHRC1 on GIST cells was reversed by using a Wnt5a neutralizing antibody and inhibitors of Rac1 or ROCK. Taken together, these data indicate that CTHRC1 may serve as a new predictor of recurrence risk and prognosis in post-operative GIST patients and may play an important role in facilitating GIST progression. Furthermore, CTHRC1 promotes GIST cell migration and invasion by activating Wnt/PCP-Rho signaling, suggesting that the CTHRC1-Wnt/PCP-Rho axis may be a new therapeutic target for interventions against GIST invasion and metastasis., (Copyright © 2014 Neoplasia Press, Inc. Published by Elsevier Inc. All rights reserved.)
- Published
- 2014
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15. Physico-chemical characterization of the temperature dependent hydration kinetics of Gleditsia sinensis gum.
- Author
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Jian HL, Lin XJ, Zhang WM, Sun DF, and Jiang JX
- Subjects
- Galactose chemistry, Kinetics, Mannans, Models, Chemical, Molecular Weight, Solubility, Viscosity, Gleditsia chemistry, Plant Gums chemistry, Temperature
- Abstract
The physico-chemical properties and hydration kinetics of Gleditsia sinensis gum were investigated to evaluate its temperature dependence. The increase of temperature resulted in improved solubility of G. sinensis gum, and the dissolved galactomannan showed decreased degree of galactose substitution (DSGal) and increased molecular weight (p<0.05, ANOVA). The solubility of G. sinensis galactomannan at 25, 45, 60 and 80 °C was 73.4, 83.8, 98.1, and 99.4%, respectively. Weibull and Logarithmic models were well fitted (R(2)>0.96), and the hydration index t0.8 at different temperatures varied in the range of 51-302 min. It was found that galactomannan with low DSGal and high molecular weight exhibited slow hydration rate and poor solubility., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
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16. Enzymatic production and characterization of manno-oligosaccharides from Gleditsia sinensis galactomannan gum.
- Author
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Jian HL, Zhu LW, Zhang WM, Sun DF, and Jiang JX
- Subjects
- Dietary Fiber, Galactose analogs & derivatives, Hydrolysis, Kinetics, Molecular Weight, Oligosaccharides chemical synthesis, Prebiotics, Solutions chemistry, Temperature, Viscosity, Gleditsia chemistry, Mannans chemistry, Oligosaccharides chemistry, Plant Gums chemistry
- Abstract
Enzymatic hydrolysis of Gleditsia sinensis gum was performed to produce manno-oligosaccharides having functional applications as dietary fiber and prebiotics. The optimum hydrolysis conditions, including enzyme loading, temperature and time, from response surface methodology were 8.1 U/g, 57.4 °C and 34.1 h, respectively. The yield of DP 1-5 oligosaccharides was 75.9% (29.1 g/L). The Michaelis-Menten kinetics and molecular weight distribution were determined. The obtained oligosaccharides were further separated by HPLC and SEC, and the galactose distribution of G. sinensis gum was elucidated. Results indicated that G. sinensis gum has potential to produce value-added oligosaccharides in food industries., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
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17. Homoisoflavonoids from the medicinal plant Portulaca oleracea.
- Author
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Yan J, Sun LR, Zhou ZY, Chen YC, Zhang WM, Dai HF, and Tan JW
- Subjects
- Cell Line, Tumor, Humans, Inhibitory Concentration 50, Plant Components, Aerial chemistry, Plants, Medicinal chemistry, Antineoplastic Agents isolation & purification, Antineoplastic Agents pharmacology, Isoflavones isolation & purification, Isoflavones pharmacology, Portulaca chemistry
- Abstract
Four homoisoflavonoids named portulacanones A-D, identified as 2'-hydroxy- 5,7-dimethoxy-3-benzyl-chroman-4-one, 2'-hydroxy-5,6,7-trimethoxy-3-benzyl-chroman-4-one, 5,2'-dihydroxy-6,7-dimethoxy-3-benzyl-chroman-4-one, and 5,2'-dihydroxy-7-methoxy-3-benzylidene-chroman-4-one, were isolated from aerial parts of the plant Portulaca oleracea along with nine other known metabolites. Their structures were established on the basis of extensive spectroscopic analyses. Portulacanones A-D is the first group of homoisoflavonoids so far reported from the family Portulacaceae. They represent a rare subclass of homoisoflavonoids in nature with a structural feature of a single hydroxyl group substituted at C-2' rather than at C-4' in ring B of the skeleton. Three homoisoflavonoids and the known compound 2,2'-dihydroxy-4',6'-dimethoxychalcone selectively showed in vitro cytotoxic activities towards four human cancer cell lines. Especially 2,2'-dihydroxy-4',6'-dimethoxychalcone showed cytotoxic activity against cell line SGC-7901 with an IC₅₀ value of 1.6 μg/ml, which was more potent than the reference compound mitomycin C (IC₅₀ 13.0 μg/ml)., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
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18. Factor XII stimulates ERK1/2 and Akt through uPAR, integrins, and the EGFR to initiate angiogenesis.
- Author
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LaRusch GA, Mahdi F, Shariat-Madar Z, Adams G, Sitrin RG, Zhang WM, McCrae KR, and Schmaier AH
- Subjects
- Animals, Aorta, Thoracic cytology, Aorta, Thoracic metabolism, Cell Division physiology, Cells, Cultured, Endothelial Cells cytology, Endothelial Cells metabolism, Enzyme Inhibitors pharmacology, Factor XII pharmacology, Humans, Integrins metabolism, MAP Kinase Signaling System drug effects, Mice, Mice, Inbred C57BL, Mice, Knockout, Mitogen-Activated Protein Kinase 1 antagonists & inhibitors, Mitogen-Activated Protein Kinase 1 metabolism, Mitogen-Activated Protein Kinase 3 antagonists & inhibitors, Mitogen-Activated Protein Kinase 3 metabolism, Neovascularization, Physiologic drug effects, Phosphorylation drug effects, Phosphorylation physiology, Umbilical Veins cytology, ErbB Receptors metabolism, Factor XII metabolism, MAP Kinase Signaling System physiology, Neovascularization, Physiologic physiology, Proto-Oncogene Proteins c-akt metabolism, Receptors, Urokinase Plasminogen Activator metabolism
- Abstract
Factor XII (FXII) and high molecular weight kininogen (HK) mutually block each other's binding to the urokinase plasminogen activator receptor (uPAR). We investigated if FXII stimulates cells by interacting with uPAR. FXII (3-62nM) with 0.05mM Zn(2+) induces extracellular signal-related kinase 1/2 (ERK1/2; mitogen-activated protein kinase 44 [MAPK44] and MAPK42) and Akt (Ser473) phosphorylation in endothelial cells. FXII-induced phosphorylation of ERK1/2 or Akt is a zymogen activity, not an enzymatic event. ERK1/2 or Akt phosphorylation is blocked upstream by PD98059 or Wortmannin or LY294002, respectively. An uPAR signaling region for FXII is on domain 2 adjacent to uPAR's integrin binding site. Cleaved HK or peptides from HK's domain 5 blocks FXII-induced ERK1/2 and Akt phosphorylation. A beta(1) integrin peptide that binds uPAR, antibody 6S6 to beta(1) integrin, or the epidermal growth factor receptor (EGFR) inhibitor AG1478 blocks FXII-induced phosphorylation of ERK1/2 and Akt. FXII induces endothelial cell proliferation and 5-bromo-2'deoxy-uridine incorporation. FXII stimulates aortic sprouting in normal but not uPAR-deficient mouse aorta. FXII produces angiogenesis in matrigel plugs in normal but not uPAR-deficient mice. FXII knockout mice have reduced constitutive and wound-induced blood vessel number. In sum, FXII initiates signaling mediated by uPAR, beta(1) integrin, and the EGFR to induce human umbilical vein endothelial cell proliferation, growth, and angiogenesis.
- Published
- 2010
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19. Differences in ventricular vulnerability, serum enzyme activities, and electrolyte levels between male and female broilers.
- Author
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Zhang W, He C, Qiao J, Dong SS, Li SW, and Zhang WM
- Subjects
- Animals, Aspartate Aminotransferases blood, Chickens blood, Chickens growth & development, Creatine Kinase blood, Female, L-Lactate Dehydrogenase blood, Male, Potassium Chloride toxicity, Poultry Diseases blood, Ventricular Fibrillation chemically induced, Chickens metabolism, Death, Sudden veterinary, Electrolytes blood, Poultry Diseases metabolism, Sex Characteristics, Ventricular Fibrillation veterinary
- Abstract
Sudden death syndrome (SDS) is one of the most serious diseases of fast-growing broilers. The incidence of SDS may result from a decrease in ventricular function. The purpose of this study was to explore the mechanism of sexual difference in the sensitivity of broilers to SDS by measuring their ventricular vulnerability, serum enzyme activities, and serum electrolyte levels. Results were as follows. 1) Ventricular fibrillation thresholds induced by injection of KCl and by electrical stimulus of male broilers were both significantly lower than those of female broilers (P < 0.05), suggesting that the ventricular vulnerability of male broilers was higher than that of female broilers. 2) Serum lactate dehydrogenase and creatine kinase activities of male broilers were significantly higher than those of female broilers (P < 0.01), but there was not a significant difference in serum aspartate aminotransferase activity between male and female broilers. 3) No significant difference was observed in serum electrolyte levels of potassium, sodium, and chloride between males and females. From these results, we concluded that there is a significant difference between males and females in their ventricular vulnerability and serum enzyme activities, which may result in a higher sensitivity of male broilers to injury of the myocardium by stress and may further result in a sexual difference in sensitivity to SDS.
- Published
- 2008
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20. A comparative study on Pb2+, Zn2+ and Cd2+ sorption onto zirconium phosphate supported by a cation exchanger.
- Author
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Zhang QR, Du W, Pan BC, Pan BJ, Zhang WM, Zhang QJ, Xu ZW, and Zhang QX
- Subjects
- Adsorption, Hydrogen-Ion Concentration, Cadmium isolation & purification, Calcium chemistry, Lead isolation & purification, Water Pollutants, Chemical isolation & purification, Zinc isolation & purification
- Abstract
In the present study, a novel hybrid sorbent ZrP-001 was prepared by loading zirconium phosphate (ZrP) onto a strongly acidic cation exchanger D-001. Sorption behavior of Pb(2+), Zn(2+), and Cd(2+) onto ZrP-001 was experimentally examined by comparing with the host exchanger D-001. ZrP-001 was characterized by scanning electron micrograph (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), pH-titration and pore size distribution analysis. Sorption of the heavy metals onto ZrP-001 was found to be pH-dependent due to the ion exchange mechanism. Compared to D-001, a smaller pore size of ZrP-001 due to the ZrP dispersion consequently resulted in a lower sorption rate. Competitive effect of Ca(2+) on sorption of heavy metals onto ZrP-001 and D-001 was compared to elucidate sorption preference of the hybrid sorbent towards heavy metals. More favorable sorption of ZrP-001 than D-001 was observed for all the three metals and their sorption preference onto ZrP-001 followed the order Pb(2+)>>Zn(2+) approximately Cd(2+). Fixed-bed sorption results and its efficient regeneration property further demonstrated that ZrP-001 is a potential candidate for removing heavy metals from contaminated water.
- Published
- 2008
- Full Text
- View/download PDF
21. Endothelin-1 enhances proliferation of lung cancer cells by increasing intracellular free Ca2+.
- Author
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Zhang WM, Zhou J, and Ye QJ
- Subjects
- Blotting, Western, Cell Line, Tumor, Egtazic Acid pharmacology, Endothelin-1 biosynthesis, Endothelin-1 pharmacology, Humans, Nifedipine pharmacology, Receptors, Endothelin biosynthesis, Reverse Transcriptase Polymerase Chain Reaction, Calcium metabolism, Cell Proliferation drug effects, Endothelin-1 physiology, Lung Neoplasms metabolism, Lung Neoplasms pathology
- Abstract
Endothelin-1 (ET-1), the most potent vasoconstrictor, has been shown to be mitogenic in many tumor cells as well as in vascular cells. It was previously reported that the mRNA of ET-1 and endothelin receptors (ETRs) are expressed in lung cancer cells. However, their biological role in lung cancer remains to be explored. The purpose of this study was to determine whether ET-1 stimulates proliferation of the human lung adenocarcinoma cell SPC-A1 and probe its cellular mechanism. Reverse-transcription polymerase chain reaction and Western blot analysis showed that both the mRNA and protein of ET-1, ET A R and ET B R are expressed in SPC-A1 cells. Application of ET-1 at 10(-15)-10(-8) M caused a dose-dependent cell proliferation and an increase in intracellular free Ca2+ concentration ([Ca2+]i). This ET-1-induced cell proliferation and [Ca2+]i increase were completely abolished by BQ123, a selective ET A R antagonist, but not by BQ788, a selective ET B R antagonist. Furthermore, it was significantly reduced by U73122, a specific inhibitor of phospholipase C (PLC), but not by U73433, the structural isomer of U73122. Chelating extracellular Ca2+ or blocking voltage dependent calcium channels by nifedipine also significantly reduced the mitogenic effect of ET-1 and [Ca2+]i increase in SPC-A1 cells. These results indicate that ET-1 acts as an autocrine growth factor and enhances proliferation of SPC-A1 cells via activation of ET A R. The phosphoinositol/Ca2+ pathway and Ca2+ influx through voltage dependent Ca2+ channels activated by ET A R contribute to this process.
- Published
- 2008
- Full Text
- View/download PDF
22. Deletion of murine kininogen gene 1 (mKng1) causes loss of plasma kininogen and delays thrombosis.
- Author
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Merkulov S, Zhang WM, Komar AA, Schmaier AH, Barnes E, Zhou Y, Lu X, Iwaki T, Castellino FJ, Luo G, and McCrae KR
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Bradykinin blood, Gene Deletion, Genetic Vectors genetics, Homozygote, Kininogens chemistry, Kininogens deficiency, Kininogens genetics, Mice, Mice, Knockout, Molecular Sequence Data, RNA, Messenger genetics, Sequence Alignment, Thrombosis genetics, Time Factors, Kininogens metabolism, Plasma metabolism, Thrombosis metabolism
- Abstract
High-molecular-weight kininogen (HK) plays an important role in the assembly of the plasma kallikrein-kinin system. While the human genome contains a single copy of the kininogen gene, 3 copies exist in the rat (1 encoding K-kininogen and 2 encoding T-kininogen). Here, we confirm that the mouse genome contains 2 homologous kininogen genes, mKng1 and mKng2, and demonstrate that these genes are expressed in a tissue-specific manner. To determine the roles of these genes in murine development and physiology, we disrupted mKng1, which is expressed primarily in the liver. mKng1(-/-) mice were viable, but lacked plasma HK and low-molecular-weight kininogen (LK), as well as DeltamHK-D5, a novel kininogen isoform that lacks kininogen domain 5. Moreover, despite normal tail vein bleeding times, mKng1(-/-) mice displayed a significantly prolonged time to carotid artery occlusion following Rose Bengal administration and laser-induced arterial injury. These results suggest that a single gene, mKng1, is responsible for production of plasma kininogen, and that plasma HK contributes to induced arterial thrombosis in mice.
- Published
- 2008
- Full Text
- View/download PDF
23. Electro-acupuncture induced NGF, BDNF and NT-3 expression in spared L6 dorsal root ganglion in cats subjected to removal of adjacent ganglia.
- Author
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Chen J, Qi JG, Zhang W, Zhou X, Meng QS, Zhang WM, Wang XY, and Wang TH
- Subjects
- Animals, Brain-Derived Neurotrophic Factor genetics, Brain-Derived Neurotrophic Factor metabolism, Cats, Cell Size, Denervation, Functional Laterality physiology, Ganglia, Spinal cytology, Ganglia, Spinal injuries, Growth Cones metabolism, Growth Cones ultrastructure, Immunohistochemistry, Lumbar Vertebrae, Male, Nerve Growth Factor genetics, Nerve Growth Factor metabolism, Neuronal Plasticity physiology, Neurons, Afferent cytology, Neurotrophin 3 genetics, Neurotrophin 3 metabolism, RNA, Messenger metabolism, Treatment Outcome, Up-Regulation physiology, Electroacupuncture methods, Ganglia, Spinal metabolism, Nerve Growth Factors metabolism, Nerve Regeneration physiology, Neurons, Afferent metabolism
- Abstract
This study evaluated the effect of electro-acupuncture (EA) on the NGF, BDNF and NT-3 expression in spared L6 dorsal root ganglion (DRG) in cats subjected to bilateral removal of L1-L5 and L7-S2 DRG, using immunostaining, in situ hybridization and RT-PCR. The positive products of NGF, NT-3 protein and mRNA in the small and large neurons of spared L6 DRG in EA side increased greatly more than that of control side, while the increased BDNF was only noted in small and medium-sized neurons. RT-PCR demonstrated that the mRNA level for three factors was not influenced by EA in intact DRG, when a significant increase was seen in the spared L6 DRG of EA side. As it has been well known that DRG neurons project to the spinal cord wherein morphological plasticity has been present after DRG removal, the present results might have some bearing to the observed phenomenon.
- Published
- 2007
- Full Text
- View/download PDF
24. Novel missense mutations in the first Chinese patient with very-long-chain acyl-CoA dehydrogenase deficiency.
- Author
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Law LK, Tang NL, Lam CW, Tong MK, Mak TW, Zhang WM, and Wanders RJ
- Subjects
- Adolescent, Asian People, Female, Humans, Acyl-CoA Dehydrogenase, Long-Chain deficiency, Acyl-CoA Dehydrogenase, Long-Chain genetics, Mutation, Missense
- Published
- 2007
- Full Text
- View/download PDF
25. Tandem Sp1/Sp3 sites together with an Ets-1 site cooperate to mediate alpha11 integrin chain expression in mesenchymal cells.
- Author
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Lu N, Heuchel R, Barczyk M, Zhang WM, and Gullberg D
- Subjects
- Animals, Base Sequence, Binding Sites, Cell Line, Cell Line, Tumor, Humans, Integrin alpha Chains chemistry, Integrin alpha Chains metabolism, Mice, Molecular Sequence Data, Promoter Regions, Genetic, Proto-Oncogene Protein c-ets-1 chemistry, Integrin alpha Chains genetics, Mesoderm physiology, Proto-Oncogene Protein c-ets-1 metabolism, Sp3 Transcription Factor metabolism
- Abstract
Alpha11beta1 integrin is a collagen receptor, which is expressed in a highly regulated manner in a specific subset of ectomesenchymally and mesodermally derived cells. We previously established that a 3 kb region upstream of the transcription start site of the ITGA11 gene efficiently induced alpha11 transcription in a cell-type specific manner. Using the human fibrosarcoma cell line HT1080 and human skin fibroblasts, we now report that the majority of the activity in the proximal promoter resides in a region spanning nt +25 to nt -176. Mutation and deletion analyses using luciferase reporter assays showed that tandem low affinity Sp1/Sp3 binding sites, together with an Ets-1-like binding site, were needed for the proximal promoter activity in mesenchymal cells. EMSAs and supershift assays showed that Sp1 and Sp3 both bind to the Sp1/Sp3 binding sites, whereas occupation of the Ets-1 binding site appears to be Sp3-dependent. Chromatin immunoprecipitation assays verified that Sp1, Sp3 and Ets-1 can bind the promoter in vivo. In heterologous Drosophila SL2 cells, Sp1, Sp3 and Ets-1 all transactivated the alpha11 promoter, with Sp1 being the most efficient activator. The lack of any synergistic effect of Sp1/Sp3 and Ets-1 in SL2 cells indicates that an Ets family member other than Ets-1 might be involved in regulating alpha11 transcription in mesenchymal cells. The central role of Sp1 in regulating alpha11 RNA transcription was further verified by the ability of the Sp1 inhibitor mithramycin A to efficiently attenuate alpha11 RNA and protein levels in primary fibroblasts. The proximal promoter itself was able to confer cell-type specific transcription on HT1080 cells and embryonic fibroblasts but not on U2OS and JAR cells. We speculate that the "mesenchymal signature" of alpha11 integrin gene expression is controlled by the activity of Sp1/Sp3, fibroblast-specific combinations of Ets family members and yet unidentified enhancer-binding transcription factors.
- Published
- 2006
- Full Text
- View/download PDF
26. Application of an effective method in predicting breakthrough curves of fixed-bed adsorption onto resin adsorbent.
- Author
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Pan BC, Meng FW, Chen XQ, Pan BJ, Li XT, Zhang WM, Zhang X, Chen JL, Zhang QX, and Sun Y
- Subjects
- Adsorption, Hydrogen-Ion Concentration, Models, Chemical, Nitrophenols chemistry, Osmolar Concentration, Phenol chemistry, Reproducibility of Results, Temperature, Water chemistry, Industrial Waste prevention & control, Resins, Synthetic chemistry, Water Pollutants, Chemical isolation & purification, Water Pollution, Chemical prevention & control
- Abstract
Removal of many organic pollutants including phenolic compounds from industrial wastewater can always be achieved by fixed-bed adsorption onto the polymeric resin adsorbent, and the relevant breakthrough curves would provide much valuable information to help to design a fixed-bed adsorption process in field application. In the present study, a model developed based on the constant-pattern wave approach theory and the Freundlich model was adopted to describe the breakthrough curves of phenol and p-nitrophenol adsorption onto a macroreticular resin adsorbent NDA-100 from aqueous solution. Column experiments were performed at different conditions to verify the model and the results proved that the model would describe the breakthrough curves well. Effect of the operation parameters on breakthrough curves was also discussed to get helpful information in choosing the adsorption process.
- Published
- 2005
- Full Text
- View/download PDF
27. Adsorption of phenolic compounds from aqueous solution onto a macroporous polymer and its aminated derivative: isotherm analysis.
- Author
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Pan BC, Zhang X, Zhang WM, Zheng JZ, Pan BJ, Chen JL, and Zhang QX
- Subjects
- Adsorption, Amines, Models, Chemical, Solutions, Temperature, Phenols chemistry, Polymers chemistry, Water Pollutants, Chemical isolation & purification, Water Pollution, Chemical prevention & control
- Abstract
Adsorption of phenolic compounds from aqueous solution to a macroporous polymeric adsorbent (CHA-111), its animated derivative (MCH-111) and a reference weakly anion exchanger (ND-900) was studied. Experimental results indicated that amino functional groups on the polymeric matrix play an important role in phenol adsorption by MCH-111 and ND-900, which was attributed to the formation of hydrogen bonding between the phenol molecule and the amino group on the polymeric matrix. The semi-empirical Freundlich isotherm equation and its reduced form were employed to interpret the adsorption behavior. A site energy distribution model based on the Polanyi adsorption potential theory can elucidate the adsorption mechanism reasonably.
- Published
- 2005
- Full Text
- View/download PDF
28. Analysis of the human integrin alpha11 gene (ITGA11) and its promoter.
- Author
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Zhang WM, Popova SN, Bergman C, Velling T, Gullberg MK, and Gullberg D
- Subjects
- Alternative Splicing, Base Sequence genetics, Cloning, Molecular, Exons genetics, Humans, Molecular Sequence Data, Transcription Initiation Site, Tumor Cells, Cultured, Integrin alpha Chains genetics, Promoter Regions, Genetic genetics
- Abstract
Integrin alpha11beta1 is a collagen receptor which is expressed in a subset of mesenchymally-derived tissues during embryogenesis. Based on available human chromosome 15-derived sequences and genomic PCR, the complete exon structure of ITGA11, including the proximal promoter, was assembled into 30 exons. The inserted region (encoding amino acids 804-826) distinguishing alpha11 from other integrin alpha chains, was placed in the very beginning of exon 20. PCR data failed to show alternative splicing of RNA transcribed from this region. Using the oligo-capping technique a major transcription start site was mapped 30 nucleotides upstream of the translation start and identified as an abbreviated initiator sequence. Promoter sequence analysis in silico suggested the presence of multiple binding sites for transcription factors in the region upstream of the transcription start. 3 kb of the 5' flanking sequence was isolated and used to generate luciferase promoter constructs. In the fibrosarcoma cell line HT1080 a core promoter [nt (-)127-(+)25], a potential silencer region [nt (-)400-(-)127] and a potential enhancer region [nt (-)1519-(-)400], were identified as being important for alpha11 transcription in mesenchymal cells. Furthermore, studies of the promoter region will provide valuable information regarding the molecular mechanisms underlying the cell- and tissue- specific expression pattern of ITGA11., (Copyright 2002 Elsevier Science B.V. and International Society of Matrix Biology)
- Published
- 2002
- Full Text
- View/download PDF
29. Expression and characterization of trypsinogen produced in the human male genital tract.
- Author
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Paju A, Bjartell A, Zhang WM, Nordling S, Borgström A, Hansson J, and Stenman UH
- Subjects
- Blotting, Northern, Humans, Immunohistochemistry, In Situ Hybridization, Isoenzymes isolation & purification, Isoenzymes metabolism, Male, Prostate-Specific Antigen physiology, Semen enzymology, Trypsin pharmacology, Trypsinogen isolation & purification, Trypsinogen metabolism, Zinc pharmacology, Genitalia, Male enzymology, Isoenzymes physiology, Trypsinogen physiology
- Abstract
Trypsinogen is a serine proteinase produced mainly by the pancreas, but it has recently been found to be expressed also in several cancers such as ovarian and colon cancer and in vascular endothelial cells. In this study, we found that trypsinogen-1 and -2 are present at high concentrations (median levels, 0.4 and 0.5 mg/L, respectively) in human seminal fluid and purified them to homogeneity by immunoaffinity and anion exchange chromatography. Purified trypsinogen isoenzymes displayed a M(r) of 25 to 28 kd in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting. Most of the trypsinogen-1 purified from seminal fluid was enzymatically active whereas trypsinogen-2 occurred as the proform, which could be activated by enteropeptidase in vitro. Immunohistochemically, trypsinogen protein was detected in the human prostate, urethra, utriculus, ejaculatory duct, seminal vesicles, deferent duct, epididymal glands, and testis. Expression of trypsinogen mRNA in the same organs was demonstrated by in situ hybridization. Trypsinogen mRNA was also detected in the prostate and seminal vesicles by reverse transcriptase-polymerase chain reaction and Northern blotting. Isolated trypsin was shown to activate the proenzyme form of prostate-specific antigen. These results suggest that trypsinogen isoenzymes found in seminal fluid are produced locally in the male genital tract and that they may play a physiological role in the semen.
- Published
- 2000
- Full Text
- View/download PDF
30. Decreased affinity of K-receptor binding during reperfusion following ischaemic preconditioning in the rat heart.
- Author
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Xia Q, Zhang WM, Shen YL, and Wong TM
- Subjects
- Analgesics metabolism, Animals, Male, Myocardial Ischemia metabolism, Myocardium metabolism, Pyrrolidines metabolism, Rats, Rats, Sprague-Dawley, Sarcolemma metabolism, Sarcolemma ultrastructure, Tritium, Ventricular Fibrillation etiology, Ventricular Fibrillation metabolism, Ventricular Function physiology, Benzeneacetamides, Myocardial Ischemia physiopathology, Myocardium ultrastructure
- Abstract
The effects of ischaemic preconditioning with three cycles of ischaemia of 3 min and reperfusion of 5 min each cycle on ventricular fibrillation threshold (VFT) and ventricular fibrillation (VF), and binding properties of tritiated U69,593, a selective kappa opioid-receptor (k-receptor) agonist, during subsequent ischaemia and/or reperfusion were studied in the rat heart. It was found that ischaemic preconditioning significantly enhanced the VFT values during ischaemic and reperfusion. VF during the subsequent reperfusion period was also significantly reduced. The Kd of the [3H]U69,593 binding sites in the sarcolemma of the heart at 5 min of reperfusion was significantly increased following ischaemic preconditioning. The Bmax was, however, not altered after the preconditioning. The study provides evidence for the first time suggesting that the cardioprotective effects of ischaemic preconditioning may be related to a reduction in affinity of the K-receptor binding.
- Published
- 1996
- Full Text
- View/download PDF
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