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Biomedical subjects

Hui Zhang

Publications and source records attributed to Hui Zhang.

At least 289 records · Page 16Linked to original sources
PubMed2004

[Construction of pcDNA3.1(+)/ hTSHR and its expression in COS-7 cells].

AIM: To construct the recombinant eukaryotic expression vector pcDNA3.1(+)hTSHR and express it in COS-7 cells. METHODS: The full length cDNA sequence of hTSHR was obtained via the plasmid vector pBluescript SK(-)/hTSHR cut with EcoR I and Xba I, and then subcloned into eukaryotic expression vector pcDNA3.1(+). Constructed pcDNA3.1/hTSHR was identified by restricting enzyme digestion analysis, PCR amplifying and DNA sequencing. The recombinant expression plasmid was transfected into COS-7 cells by Lipofectin method. Human TSHR protein expression on COS-7 cells was detected by RT-PCR and immunocytochemical staining. RESULTS: Obtained full-length sequence of hTSHR gene was identical with that included in GenBank. Restriction enzyme digestion, PCR amplifying and DNA sequencing confirmed that pcDNA3.1/hTSHR had been constructed successfully. The recombinant plasmid could express hTSHR protein with activity on COS-7 cells. CONCLUSION: The pcDNA3.1/hTSHR has been successfully constructed, which will contribute to further studies on the TSHR function and to the establishment of a good animal model for Graves' disease.

Animals↗
PubMed2004

[Immunohistochemical and morphometrical study on the expression of interleukin-10 (IL-10) in different expressive parts during cutaneous wound healing in mice].

OBJECTIVE: To explore the expression of interleukin-10 (IL-10) in different expressive parts and its relationship with the wound age during cutaneous wound healing in mice. METHODS: Immunohistochemical and morphometrical analysis methods were performed on vital skin wounds. RESULTS: In normal and injury mouse skin IL-10 immunoreactivity was observed in epidermal cells. The expression of IL-10 in epidermal cells was already enhanced since 1-3h after incision, and it returned to lower lever by 24h, but increased again at 48h after injury. IL-10 immunoreactivive cells under epidermis were mainly infiltrating mononuclear cells. Morphometrically, the ratio of the number of infiltrating cells was evaluated. A subsequent increase in the IL-10 positive cells was observed in the granulation tissue beyond the wound and in dermal at 6h after incision, and the maximum ratio was (51.41 +/- 3.12)% in a 72h-old wound. Then the positive cells gradually decreased (29.38 +/- 2.64)%-(5.56 +/- 4.74)% after incision 96-168h. CONCLUSIONS: The expression characteristics of IL-10 in different expressive parts should be related to the wound age and morphometry of different expressive parts may be employed for determining the wound age.

Animals↗
PubMed2004

Different contributions of STAT3, ERK1/2, and PI3-K signaling to cardiomyocyte hypertrophy by cardiotrophin-1.

AIM: To assess the contribution of signal transducer and activator of transcription 3 (JAK-STAT3) pathway, extracellular signal-regulated kinases1/2 (ERK1/2) pathway, and phosphatidylinositol 3-kinase (PI3-K) pathway to cardiomyocytes hypertrophy induced by cardiotrophin-1 (CT-1), a new member of interleukin-6 (IL-6) family of cytokines. METHODS: STAT3, ERK1/2, and PI3-K were assessed by Western blot analysis. Activity of ERK1/2 was also confirmed by in-gel kinase assay. Hypertrophy of cardiomyocyte was evaluated by [3H]leucine incorporation and cellular protein-to-DNA ratio. RESULTS: CT-1 simultaneously activated phosphorylation of STAT3, ERK1/2, and PI3-K in rat cardiomyocytes. Parthenolide, an inhibitor of STAT, suppressed CT-1-induced [3H]leucine incorporation by 88.3 % and protein-to-DNA ratio by 75.0 %. U0126, an MEK1/2 inhibitor, increased CT-1-induced the phosphorylation of STAT3 in a dose-dependent manner and, consistently, augmented CT-1-induced increase in [3H]leucine incorporation and cellular protein-to-DNA ratio by 17.6 % and 16.3 %, respectively. Wortmannin, a PI3-K inhibitor, did not influence CT-1-induced [3H]leucine incorporation and cellular protein-to-DNA ratio. CONCLUSION: The hypertrophic effect of CT-1 was essentially mediated by STAT3, independent of PI3-K, and negatively regulated by ERK1/2 via inhibiting the phosphorylation of STAT3. The interaction between STAT3 and ERK1/2 in CT-1-induced signaling contributes to development of cardiac hypertrophy.

Androstadienes↗
PubMed2004

Crosstalk between ERK1/2 and STAT3 in the modulation of cardiomyocyte hypertrophy induced by cardiotrophin-1.

BACKGROUND: The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway and the extracellular signal-regulated kinases 1/2 (ERK1/2) pathway are the two major independent signal transduction pathways. However, it has recently been found that STAT3 may be negatively regulated by ERK1/2 in gp130-dependent signaling. Cardiotrophin-1 (CT-1), a potent novel hypertrophic cytokine, depends on gp130 to induce signaling and depends on STAT3 to exert hypertrophic effect. In this study, we examined whether STAT3 activity was negatively regulated by ERK1/2 during CT-1-induced signaling in rat cardiomyocytes and, if so, whether such crosstalk interfered with the hypertrophic effect of CT-1 and, furthermore, whether the mechanism underlying the crosstalk involved phosphorylation of serine 727 (S727) in STAT3. METHODS: The activities of ERK1/2 and STAT3 were assessed by in-gel kinase assay and Western blot analysis, respectively. The role of S727 phosphorylation in the crosstalk between ERK1/2 and STAT3 was determined by a transient transfection study using a STAT3S727A mutant. Cardiomyocyte hypertrophy was evaluated by the cellular protein-to-DNA ratio and [(3)H]-leucine incorporation. RESULTS: CT-1 simultaneously activated both ERK1/2 and STAT3 in rat cardiomyocytes. Inhibition of ERK1/2 by U0126 resulted in an increase of CT-1-induced tyrosine phosphorylation of STAT3 and, consequently, the protein-to-DNA ratio and [(3)H]-leucine incorporation. Transient transfection of the cells with STAT3S727A had no significant effect on CT-1-induced tyrosine phosphorylation of STAT3. CONCLUSIONS: STAT3 is activated by CT-1 in rat cardiomyocytes, but full activation is mitigated by the simultaneous activation of ERK1/2. The inhibition of ERK1/2 increases the activity of STAT3, which, in turn, enhances the hypertrophic effect of CT-1. The crosstalk between ERK1/2 and STAT3 is independent of the phosphorylation of the S727 in STAT3. Such crosstalk may contribute to the development of adequate cardiac hypertrophy.

Active Transport, Cell Nucleus↗
PubMed2004

Comparison of diode and argon laser lesions in rabbit retina.

PURPOSE: To compare the histological alteration of retina with various spot intensities between diode and argon lasers in order to instruct the clinical use of 810 nm diode laser. METHODS: Transpupillary retinal photocoagulations were performed on 42 eyes of 27 pigmented rabbits. Histopathologic alteration of lesions in different intensities and different time intervals after irradiation produced by diode and argon laser was observed and compared using light microscopy. Areas of various lesions measured by image analysis system (CMIAS) were compared quantitatively. RESULTS: Histopathologically, two-week-old grade 2 lesions produced by diode laser induced the disappearance of outer nuclear cells. More than a half of all showed reduction in number of outer nuclear layer cells in argon. Fibroblasts appeared in the diode grade 3 lesions 5 days after irradiation. CMIAS data showed that all the areas of diode lesions immediately after photocoagulation were to be larger than those of argon laser lesions in the same spot intensity (P < 0.05). However, twenty-four hours after photocoagulation, the area of the diode lesions increased less than that of the argon laser lesions (8% vs. 23%). CONCLUSION: The acute histological effect caused by 810 nm diode laser and argon green laser is similar, while the expansion of lesion area 24 hours after photocoagulation was less with the diode laser compared to the argon. This may be the first report in the literature regarding quantitative analysis of the delayed reaction of argon green lasers.

Animals↗
PubMed2004

Acquiring laparoscopic manipulative skills: a virtual tissue dissection training module.

Virtual environments for training manipulative skills in laparoscopic surgery are now well established as research areas. Tissue dissection however has not yet been adequately addressed. We have developed a virtual training module in which the task is to dissect a 3D tissue model using a simulated L-hook. Three metrics have been designed to assess performance. 1) Total deviation of actual cut path from the drawn path. 2) Total contact time between the instrument and tissue. 3) Contact discontinuity. The objective of the research was to design a basic tissue dissection module to train, in part, laparoscopic manipulative skills.

Canada↗
PubMed2004

[Soluble PD-1 can augment anti-tumor immunity induced by HSP70-peptide complex in tumor-bearing mice].

AIM: To explore the effect of soluble PD-1 (sPD-1) on the anti-tumor immunity induced by HSP70-peptide. METHODS: BALB/c mice were immunized with HSP70-peptide, then the cytotoxic activity of splenocytes was detected by MTT colorimetry. Expression of PD-1 and its ligand on splenocytes was determined by semi-quantitative RT-PCR. For some mice, sPD-1 plasmid was injected alone or in combination with HSP70-peptide and then the tumor weight and cytotoxic activity of splenocytes were measured. RESULTS: sPD-1 alone had anti-tumor effect. HSP70-peptide complex not only induced tumor-specific cytotoxic T lymphocytes(CTLs), but also promoted expression of PD-1 and its ligand. The combination of sPD-1 with HSP70-peptide complex induced much more stronger anti-tumor effect as compared with sPD-1 or HSP70-peptide alone. sPD-1 transfection in mice could enhance the cytotoxic activity of splenocytes from immunized mice. CONCLUSION: sPD-1 enhanced the anti-tumor efficacy of HSP70-peptide.

Animals↗
PubMed2004

[Overexpression of GST gene accelerates the growth of transgenic Arabidopsis under salt stress].

The Suaeda salsa glutathione s-transferase gene (GST) was inserted downstream of the 35S promoter in the plant expression vector pROK II and then was introduced into Arabidopsis thaliana by Agrobacterium tumefaciens through floral dip method. Transformants were selected for their ability to grow on medium containing kanamycin. The fact that the GST gene had been transferred into the Arabidopsis thaliana genome was confirmed by the PCR-Southern blotting analysis. After cultivation, independent homozygous transgenic lines were obtained after selection of T(3) progenies on MS medium containing kanamycin. The expression of the gene transferred into the Arabidopsis thaliana was confirmed by Northern blotting. During salt stress, analysis of total glutathione (both oxidized and reduced type) and biomass of transgenic and wild Arabidopsis. The biomass of transgenic lines (GT) was slightly but significantly greater than that of wild type line (WT), and levels of oxidized glutathione (GSSG) were significantly higher in transgenic lines than in wild type. Therefore, overexpression of GST can increase Arabidopsis growth under salt stress, and this effect can be caused by oxidation of the reduced glutathione (GSH ).

Arabidopsis↗
PubMed2004

[Transposable element mariner].

Mariner and mariner-like elements (MLEs) have been found in a wide range of organisms including human since its discovery in Drosophila mauritiana. MLEs belong to the mariner/Tc1 superfamily, one of the most diverse and widespread Class II transposable elements. MLEs have a conserved "D,D(34)D" motif in their transposases and they transpose by cut-and-paste mechanisms. Their extraordinarily wide host range and horizontal transmission in distantly related species indicate that they do not need additional host-specific factors for transposition. The evidence that MLEs could transform a wide variety of organisms especially the vertebrates supported the host-independent mechanism and suggested the availability as a kind of potential transforming vector.

Animals↗
PubMed2004

[Intervention of xuezhikang on patients of acute coronary syndrome with different levels of blood lipids].

OBJECTIVE: To observe the intervention of Xuezhikang (XZK) on patients of acute coronary syndrome (ACS) with different levels of blood lipids. METHODS: Adopting the double blind randomized controlled method, 105 patients of ACS were divided into two groups. The 53 patients in the treated group, 26 with normal blood lipids (NBL) and 27 with hyperlipemia (HL) were treated with conventional western medicine plus XZK 1.2 g per day for 12 weeks. The 52 patients in the control group, 25 with NBL and 27 with HL, were treated with conventional western medicine alone. Besides, a healthy control group consisted of 40 subjects was set up. The changes of brachial arterial endothelium-dependent diastolic function (FMD) before and after treatment was observed, the changes of blood levels of nitric oxide (NO), endothelin-1 (ET-1), C-reactive protein (CRP) and lipids were also recorded. RESULTS: Before treatment, FMD value and serum NO level were lower and ET-1 and CRP levels in ACS patients were higher than those in the healthy subjects, and a significant correlation existed between CRP, NO and FMD with LDL-C. After treated for 12 weeks, FMD value and serum NO level increased, levels of ET-1 and CRP decreased significantly in the treated group, showing significant difference to those in the control group (P < 0.05, P < 0.01). Serum levels of TC, TG and LDL-C in the treated group lowered significantly. HDL-C level in patients with HL increased significantly while in those with NBL, it showed a trend of increasing but with no statistical significance. CONCLUSION: Applying XZK in ACS patients in early stage, either with NBL or with HL, could improve the endothelial function, antagonize inflammatory response to stabilize the atheromatous plaque.

Adult↗
PubMed2004

[Determination of verapamil in dog serum and tissues by reversed-phase high performance liquid chromatography].

A method for determination of verapamil (VRPM) concentrations in dog serum and tissues was established. The study was carried out on a high performance liquid chromatograph with a reversed-phase C18 column, a mobile phase of acetate-methanol-triethylamine (40:60:1, v/v) at 1.0 mL/min, and UV detection at 228 nm. Diazepam was used as the internal standard. The detection limits of VRPM concentrations in serum and tissues were determined to be 50 microg/L and 50 ng/g, respectively. Good linearities were observed for VRPM in serum and in liver tissue (r > 0.999). The precision of the method was good and the recoveries of VRPM were higher than 90.80%. This method is rapid, accurate and convenient for determination of VRPM concentrations in serum and tissues.

Animals↗
PubMed2004

[The maxillary swing approach to resect the tumors in the skull base and the paranasopharyngeal space].

OBJECTIVE: To determine the best approach to resecting the tumors in paranasopharyngeal space and skull base. METHOD: Through a Weber-Ferguson-Longmire incision,the whole maxilla was freed from bony connections and swung laterally while remaining attached to the masseter muscle and the cheek flap. Then the skull base and paranasopharyngeal space was exposed. So the tumor could be resected completely. Two cases of tumor in paranasopharyngeal space, 1 case of tumor in skull base, by the maxillary swing approach, the tumor was resected under sight. The fat of check was used to pack the space. RESULT: One case was vascular smooth muscle tumor and 1 case was adenoid cystic carcinoma in paranasopharyngeal space, 1 case was chordoma in skull base. The last case received post-operation radiotherapy. All the cases healed with no severe dentofacial malformation and dysfunction. In the follow up period, no one recurred postoperatively. CONCLUSION: The maxillary swing approach to resect the tumor in the skull base and the paranasopharyngeal can expose better. The operation is safe with little damage.

Adult↗
PubMed2004

[An experimental study on injury of hippocampus neurons in rats by simulated push-pull maneuver of different degrees].

OBJECTIVE: To explore the degree of injury and phase of push-pull effect induced by different degrees of push-pull maneuver on hippocampus neurons in rats. METHOD: Injury of push-pull maneuver on hippocampus neurons in rats after different degrees of push-pull maneuver were determined by general evaluation of animal model, pathologic examination and electronic microscopy. RESULT: 1) General evaluation of animal model: the apoplexy index and the pathological grading increased with the increase of intensity of the push-pull maneuver. 2) Routine HE: No abnormity was found in appearance and distribution of hippocampus neurons in the control rats and various groups of +/-2 Gz exposures, and 30 min groups of +/-6 Gz, +/-8 Gz exposures, but denatured necrosis of neurons were found in 6 h and 24 h groups of +/-6 Gz, +/-8 Gz exposures. 3) Examination of ultrastructure under electronic microscope: No significant change were found in hippocampus neurons of CA1 area in 30 min and 24 h after +/-2 Gz exposures as compared with the normal control group. But various degrees of denatured necrosis of neurons were found in some of the hippocampus neurons of CA1 area in 6 h after +/-2 Gz exposures, 6 h and 24 h after +/-6 Gz and +/-8 Gz exposures. CONCLUSION: +/-6 Gz and +/-8 Gz exposures may cause injury of hippocampus tissues and it is most severe at 6 h after the +/-8 Gz exposures.

Animals↗
PubMed2004

[Eukaryotic expression and functional characterization of PD-1 extracellular domain].

The negative signal provided by interactions of costimulatory molecules, programmed death-1 (PD-1) and its ligands, PD-L1 (also B7-H1) and PD-L2 (also B7-DC), is involved in the mechanisms of tumor immune evasion. To block PD-Ls-PD-1 interactions by a soluble receptor of PD-1, we constructed a eukaryotic expression plasmid that expresses extracellular region (aa1-aa167) of murine PD-1 (pPD-1A) and, another version of pPD-1A, pPD-1B, carrying cDNAs encoding for both extracellular region of PD-1 and green fluorescent protein (GFP) reporter gene, which was inserted downstream of PD-1. Experiment of BHK cells transfected with pPD-1B determined that most expression product (sPD-1) in the cells was secreted out. FACS analysis revealed that sPD-1 was specific and bound efficiently to PD-1 ligands. Cytotoxicity assay showed that blocking PD-Ls on either tumor cells or spleen cells by sPD-1 mediated enhanced lysis of H22 cells by Hsp70-H22 peptides complexstimulated spleen cells. The constructed plasmid vector would provide a novel method of tumor gene therapy of blocking PD-Ls-PD-1 interactions by expression of soluble receptor of PD-1 in tumor sites, which could increase the antitumor activity.

Animals↗
PubMed2003

Syntaxin 1A regulates ENaC channel activity.

Na(+) entry across the apical membranes of many absorptive epithelia is determined by the number (N) and open probability (P(o)) of epithelial sodium channels (ENaC). Previous results showed that the H3 domain of syntaxin-1A (S1A) binds to ENaC to reduce N, supporting a role for S1A in the regulation of ENaC trafficking. The aim of this study was to determine whether S1A-induced reductions in ENaC current also result from interactions between cell surface ENaC and S1A that alter ENaC P(o). Injection of a glutathione S-transferase (GST)-H3 S1A fusion protein into ENaC-expressing Xenopus oocytes inhibited whole cell Na(+) current (I(Na)) by 33% within 5 min. This effect was dose-dependent, with a K(i) of 7 ng/microl (approximately 200 nm). In contrast, injection of GST alone or a H3 domain-deleted GST-S1A fusion protein had no effect on I(Na). In cell-attached patch clamp experiments, GST-H3 acutely decreased ENaC P(o) by 30%, whereas GST-S1A Delta H3 was without effect. Further analysis revealed that ENaC mean closed time was significantly prolonged by S1A. Interestingly, GST-H3 had no effect on channel activity of an ENaC pore mutant that constitutively gates open (P(o) approximately equal 1.0), supporting the idea that S1A alters the closed state of ENaC and indicating that the actions of S1A on ENaC trafficking and gating can be separated experimentally. This study indicates that, in addition to a primary effect on ENaC trafficking, S1A interacts with cell surface ENaC to rapidly decrease channel gating. This rapid effect of S1A may modulate Na(+) entry rate during rapid increases in ENaC N.

Animals↗
PubMed2003

Automated statistical analysis of protein abundance ratios from data generated by stable-isotope dilution and tandem mass spectrometry.

We describe an algorithm for the automated statistical analysis of protein abundance ratios (ASAPRatio) of proteins contained in two samples. Proteins are labeled with distinct stable-isotope tags and fragmented, and the tagged peptide fragments are separated by liquid chromatography (LC) and analyzed by electrospray ionization (ESI) tandem mass spectrometry (MS/MS). The algorithm utilizes the signals recorded for the different isotopic forms of peptides of identical sequence and numerical and statistical methods, such as Savitzky-Golay smoothing filters, statistics for weighted samples, and Dixon's test for outliers, to evaluate protein abundance ratios and their associated errors. The algorithm also provides a statistical assessment to distinguish proteins of significant abundance changes from a population of proteins of unchanged abundance. To evaluate its performance, two sets of LC-ESI-MS/MS data were analyzed by the ASAPRatio algorithm without human intervention, and the data were related to the expected and manually validated values. The utility of the ASAPRatio program was clearly demonstrated by its speed and the accuracy of the generated protein abundance ratios and by its capability to identify specific core components of the RNA polymerase II transcription complex within a high background of copurifying proteins.

Animals↗
PubMed2003

Overexpression of SOD2 increases salt tolerance of Arabidopsis.

The yeast (Schizosaccharomyces pombe) SOD2 (Sodium2) gene was introduced into Arabidopsis under the control of the cauliflower mosaic virus 35S promoter. Transformants were selected for their ability to grow on medium containing kanamycin. Southern- and northern-blot analyses confirmed that SOD2 was transferred into the Arabidopsis genome. There were no obvious morphological or developmental differences between the transgenic and wild-type (wt) plants. Several transgenic homozygous lines and wt plants (control) were evaluated for salt tolerance and gene expression. Overexpression of SOD2 in Arabidopsis improved seed germination and seedling salt tolerance. Analysis of Na+ and K+ contents of the symplast and apoplast in the parenchyma cells of the root cortex and mesophyll cells in the spongy tissue of the leaf showed that transgenic lines accumulated less Na+ and more K+ in the symplast than the wt plants did. The photosynthetic rate and the fresh weight of the transgenic lines were distinctly higher than that of wt plants after NaCl treatment. Results from different tests indicated that the expression of the SOD2 gene promoted a higher level of salt tolerance in vivo in transgenic Arabidopsis plants.

Acclimatization↗