Biomedical subjects

Hui Zhang

Publications and source records attributed to Hui Zhang.

At least 181 records · Page 10Linked to original sources

PubMed2005

[Experimental study of transplanted endothelial progenitor cells transfected with VEGF165 gene augment the survival volume of transplanted fat tissue].

OBJECTIVE: To investigate the feasibility of transplanting endothelial progenitor cells (EPCs) transfected with VEGF165 gene to free transplanted fat tissue for increasing neovascularization and the survival. METHODS: EPCs isolated from human cord blood were cultured in vitro and identified by immunocytochemistry. After transfection by VEGF165 gene, the expression of VEGF was assessed using ELISA. Then EPCs with (VEGF gene transfection group) and without VEGF165 gene transfection (EPCs group) were transplanted to free transplanted fat tissue at 18 nude mice's back, and nine nude mice transplanted with free fat tissue were injected with M199 (control group). CM-DiI was used to trace the transplanted cells. The capillary density of transplanted fat tissue was detected by CD34 immunohistochemistry. RESULTS: EPCs expressed cell markers CD34, KDR and CD133. After transfection, the expression of VEGF was positive. Transplanted EPCs survived and proliferated, and transplanted EPCs were incorporated into the capillary networks in the transplanted fat tissue. The percent of survival volume of transplanted fat tissue of VEGF gene transfection group was (96.2 +/- 8.6)%, significantly higher than that of the EPCs group [(75.3 +/- 6.8)%, P < 0.05) and M199 group [(40.2 +/- 2.5)%, P < 0.05). The capillary density of transplanted fat tissue of VEGF gene transfection group was significantly higher than those of the EPCs group and M199 group (P < 0.05). CONCLUSIONS: EPCs from human cord blood can increase free transplanted fat tissue neovascularization and the survival volume, and the ability of promoting neovascularization of EPCs transfected with VEGF165 gene is more potent than EPCs alone.

Adipose Tissue↗

PubMed2005

The association of small heat shock protein Hsp16.3 with the plasma membrane of Mycobacterium tuberculosis: dissociation of oligomers is a prerequisite.

Hsp16.3, a small heat shock protein from Mycobacterium tuberculosis (MTB), was originally identified as an immuno-dominant antigen and later found to be a major membrane protein. In vitro studies show that Hsp16.3 exists as nonamers and undergoes dynamic dissociation/re-association equilibrium in solutions. Nevertheless, neither the details nor the physiological implications of the presence of Hsp16.3 in the plasma membrane have been studied. In this study, we demonstrated that the purified Hsp16.3 proteins were able to interact with the MTB plasma membrane in a specific and reversible manner, suggesting that there might be subunit exchange between membrane-bound Hsp16.3 and soluble Hsp16.3 oligomers. The dissociation of Hsp16.3 oligomers appears to be a prerequisite for its membrane binding, which is interesting in view that the dissociation of small heat shock protein oligomers was also found to be necessary for it to bind denaturing substrate proteins. Furthermore, the oligomeric structure of Hsp16.3 seems to be more dynamic and flexible when incubating with the mycobacterium lipids. The physiological implications of these observations for Hsp16.3, and small heat shock proteins in general, are discussed.

Bacterial Proteins↗

PubMed2005

[Clinical profiles of circulating dendritic cell subsets in chronically HBV-infected patients with interferon-alpha treatment].

OBJECTIVE: To investigate the changes of circulating dendritic cell (DC) sunsets in chronic hepatitis B patients treated with alpha-interferon and correlation thereof with therapeutic effectiveness. METHODS: Twenty-five patients with chronic hepatitis B. 24 males and 1 females, aged 18 approximately 43, were treated with subcutaneous injection of alpha-interferon for 24 weeks and then followed up for another 24 weeks. Blood routine, liver function, renal function, and serum HBV DNA were examined before treatment, and 12, 24, and 48 weeks after beginning of treatment. Peripheral blood samples were collected to detect the DC subsets by flow cytometry. RESULT: Those patients with complete or partial recovery of alanine transaminase (ALT) and negative seroconversion or decrease of HBV DNA with/without negative seroconversion of HBeAg and HBsAg were grouped as alpha-interferon responders, and those failing to reach the above criteria were grouped as nonresponders. The negative seroconversion rates of HBV DNA and HBeAg, and positive seroconversion rate of anti-HBe were 35%, 40%, and 10 respectively after 24 weeks' treatment and were 40%, 33.3%, and 20% respectively after 48 weeks' treatment. The numbers of myeloid dendritic cells (mDCs) were 16.5 +/- 5.51 x 10(6)/L, 9.86 +/- 5.2 x 10(6)/L, 9.20 +/- 3.19 x 10(6)/L, and 10.0 +/- 3.64 x 10(6)/L respectively in the alpha-interferon responders (P = 0.045); and were 14.41 +/- 6.62 x 10(6)/L, 14.0 +/- 5.27 x 10(6)/L, 10.40 +/- 4.6 x 10(6)/L, and 12.3 +/- 5.23 x 10(6)/L respectively in the non-responders (P = 0.283) before treatment, and after 12, 1 24, and 48 weeks' treatment respectively. The numbers of plasmacytoid dendritic cells (pDCs) were 5.91 +/- 2.35 x 10(6)/L, 4.25 +/- 2.00 x 10(6)/L, 3.30 +/- 1.55 x 10(6)/L, and 4.32 +/- 1.59 x 10(6)/L respectively in the alpha-interferon responders (P = 0.004); and were 5.10 +/- 1.72 x 10(6)/L, 4.06 +/- 1.67 x 10(6)/L, 3.89 +/- 1.25 x 10(6)/L, and 4.06 +/- 8.12 x 10(6)/L respectively in the non-responders before treatment, and after 12, 24, and 48 weeks' treatment respectively ((P = 0.211). CONCLUSION: Effective on CHB, alpha-interferon induces the percentages and numbers of circulating DC subsets, especially in the-interferon responders.

Adolescent↗

PubMed2005

In situ ozonation of anthracene in unsaturated porous media.

Soil column experiments were conducted to investigate the effect of ozonation duration, contaminant content, particle size, moisture content, OH radical scavenger and soil organic matter on the removal of anthracene by in situ ozonation. In the whole study, the gas flow rate was 100 mL/min and concentration of gaseous ozone was 40 mg/L. The removal efficiency increased with the elapsed time, but the removal rate decreased in the range of 0-90 min. As anthracene content in sand decreased from 50 to 10 mg/kg, the removal efficiency increased from 42.1% to 62.0%, and ozone passed through soil column more rapidly. However, the ozone effectiveness reduced when anthracene content dropped. Small particle size provides a large interfacial area, which led to the high removal efficiency and long ozone breakthrough time in the column. The profile of residual anthracene in soil column varied more greatly at smaller particle size. The removal efficiency reduced when the moisture content rose from 0% to 9.1%. The ozone breakthrough time also decreased with the increasing moisture content. The presence of sodium bicarbonate or humic acid reduced the removal efficiency to some extent. GC-MS was employed in this study to determine 9,10-anthraquinone as the main ozonation product.

Anthracenes↗

PubMed2005

Avidin chase reduces side effects of radioimmunotherapy in nude mice bearing human colon carcinoma.

AIM: To evaluate the influence of avidin chase on the side effects of radioimmunotherapy (RIT) in nude mice bearing human colon carcinoma and therapeutic outcome. METHODS: Purified anti-CEA monoclonal antibody (McAb) was biotinylated with NHS-biotin, and then radiolabeled with 188Re by the direct method. 188Re-labeled biotinylated anti-CEA McAb (188Re-CEA McAb-Bt) was intravenously injected followed by intravenous injection of avidin after 24 h. SPECT imaging and biodistribution study were performed at 28-48 h after the injection of 188Re-CEA McAb-Bt. Three groups of nude mice subcutaneously grafted with human colon carcinoma were treated 7 d after the graft. Mice in the avidin chase group received intravenous injection of 188Re-CEA McAb-Bt (11.1 MBq/20 microg) followed by intravenous injection of cold avidin (80 microg) after 24 h. Mice in the control group (treated group without avidin chase) only received the injection of 188Re-CEA McAb-Bt (11.1 MBq/20 microg), another control group (non-treated group) only received 0.1 mL normal saline solution. Toxicity was evaluated on the basis of change of body weight and peripheral WBC counts, and therapy effects were determined by variation in tumor volume. Histological analysis of tumors was also performed. RESULTS: Avidin chase markedly accelerated the clearance of 188Re-CEA McAb-Bt from the blood and normal tissues. The tumor uptakes of 188Re-CEA McAb-Bt at 28 h were 5.90 and 6.42% ID/g, respectively, in chase group and in non-chase group, while the tumor-to-background (T/NT) ratios were 3.19 and 0.56, respectively. The tumor uptake was slightly decreased by avidin chase, but the T/NT ratios were increased. In treated groups the growth rate of body weight and the number of WBC decreased after injection of 188Re-CEA McAb-Bt, and the WBC counts recovered earlier in the group with avidin chase than in the group without avidin chase. Compared to the non-treated group, treated groups with and without avidin chase showed significant anti-tumor effects. CONCLUSION: Avidin chase can effectively reduce the side effects of RIT, and improve therapeutic efficacy.

Animals↗

PubMed2005

Parameter characterization of high-overtone bulk acoustic resonators by resonant spectrum method.

Effects of electrode on high-overtone bulk acoustic resonator (HBAR) spectra are analyzed by numerical simulation. The figure of merit (FOM), the effective electromechanical coupling factor, k(eff)(2)(m), and the quality factor Q(s) of the unique mode are discussed based on the resonance spectra of the HBAR. It is demonstrated that electrodes with proper acoustic impedance and thickness could improve the performance of the HBAR, or degrade the performance if the electrodes are not properly chosen.

Journal Article↗

PubMed2005

Platelet activation leads to activation and propagation of the complement system.

Inflammation and thrombosis are two responses that are linked through a number of mechanisms, one of them being the complement system. Various proteins of the complement system interact specifically with platelets, which, in turn, activates them and promotes thrombosis. In this paper, we show that the converse is also true: activated platelets can activate the complement system. As assessed by flow cytometry and immunoblotting, C3 deposition increased on the platelet surface upon cell activation with different agonists. Activation of the complement system proceeded to its final stages, which was marked by the increased generation of the anaphylotoxin C3a and the C5b-9 complex. We identified P-selectin as a C3b-binding protein, and confirmed by surface plasmon resonance binding that these two proteins interact specifically with a dissociation constant of 1 microM. Using heterologous cells expressing P-selectin, we found that P-selectin alone is sufficient to activate the complement system, marked by increases in C3b deposition, C3a generation, and C5b-9 formation. In summary, we have found that platelets are capable of activating the complement system, and have identified P-selectin as a receptor for C3b capable of initiating complement activation. These findings point out an additional mechanism by which inflammation may localize to sites of vascular injury and thrombosis.

Anaphylatoxins↗

PubMed2005

Sustained low-level expression of interferon-gamma promotes tumor development: potential insights in tumor prevention and tumor immunotherapy.

Although the proinflammatory cytokine interferon-gamma (IFN-gamma) has been generally thought to enhance antitumor immune responses and be involved in antitumor mechanisms of many other immunotherapy molecules, it has also been reported that IFN-gamma could promote tumor immune evasion. In this report, by using an ideal mouse model that expresses IFN-gamma locally in muscle, we demonstrate that sustained low-level expression of IFN-gamma promotes the development of several types of tumor including H22 hepatoma, MA782/5S mammary adenocarcinoma and B16 melanoma. However, transitory expression of IFN-gamma does not have such an effect. On the other hand, sustained high-level expression of IFN-gamma mediates significant antitumor effect on H22 hepatoma. Low level of IFN-gamma upregulates expression of PD-L1, PD-L2, CTLA-4 and Foxp3, which may partly account for the tumor immune evasion promoted by IFN-gamma. Furthermore, blockade of PD-L inhibits IFN-gamma's tumor-promoting effect. Our findings provide a mechanistic link between chronic inflammation and cancer and would have potential implications for cancer prevention and also for the design of cytokine-based cancer immunotherapy.

Adenocarcinoma↗

PubMed2005

CHMIS-C: a comprehensive herbal medicine information system for cancer.

A comprehensive herbal medicine information system for cancer (CHMIS-C) has been developed. The current version of the database integrates information on more than 200 anticancer herbal recipes that have been used for the treatment of different types of cancer in clinic, 900 individual ingredients, and 8500 small organic molecules isolated from herbal medicines. Furthermore, subsidiary databases of literature references and molecular targets have been constructed. A number of web-based searching tools have been developed and integrated into the information system for efficient data mining. The compounds in the database have been linked to the corresponding entries in the National Cancer Institute's database, and to a database of drugs approved by the U.S. Food and Drug Administration. This paper provides a description of the individual subsidiary databases, integration of the entire database, and data mining tools. We demonstrate that this comprehensive information system may be used as an effective informatics tool for anticancer drug discovery.

Antineoplastic Agents, Phytogenic↗

PubMed2005

Electromigration of single molecules of DNA in a crystalline array of 300-nm silica colloids.

The velocities and conformations of single DNA chains were probed as they electromigrated at varying electric field strength through a crystalline array of silica colloids. An optically transparent film consisting of 300-nm silica colloids was formed on glass as a transparent crystalline layer of 7 mum thickness with an effective pore size of 45 nm. The behaviors of individual lambda-DNA molecules (48,502 base pairs) electromigrating through this material were observed to be analogous to the behaviors of long DNA chains in electrophoresis gels, including chain extension, hooking of chains around the matrix, and hernia formation. The electrophoretic mobility of lambda-DNA in this dense, narrow-pore material is surprisingly high: 1.8 cm2/Vs at 10 V/cm, which is at least as high as for much wider-pore gels. Imaging of the single molecules revealed that higher field strength caused increased chain extension and increased mobility, which reached an apparent plateau just above 2.0 cm2/Vs at 200 V/cm. Pulsed, crossed electric fields of 200 V/cm at 120 degrees to one another were applied to the material. The DNA chains were observed by imaging to electromigrate in an orderly fashion, and the migration rate was found to be length-dependent. The results indicate that these thin, robust, self-assembling inorganic materials are interesting as possible alternatives to polymeric gels for higher speed electrophoresis.

Bacteriophage lambda↗

PubMed2005

Toxicity of novel anti-hepatitis drug bicyclol: a preclinical study.

AIM: To study the toxicity of bicyclol to animals. METHODS: Acute toxicity test was performed in Kunming strain mice that were orally given bicyclol at the doses of 3 and 5 g/kg body weight, respectively. Wistar rats were orally administered bicyclol at a dose of 5 g/kg body weight. Death and clinical symptoms of animals were recorded within 7 d. Sub-acute toxicity test was carried out in rats that were treated with various doses of bicyclol (150, 300, 600 mg/kg) once daily for 14 d. Animal behaviors, blood biochemical markers, blood and urine pictures were examined. Chronic toxicity test was conducted in 80 Wistar rats of both sexes. The animals were orally administered with various doses of bicyclol (150, 300, 600 mg/kg, 100-400 folds corresponding to the proposed therapeutic dose (1.5 mg/(kg.d)) of bicyclol for patients) once daily for 6 mo except for Sunday. The control group was given the same volume of 0.2% sodium carboxyl methylcellulose (Na-CMC). Twenty-one beagle dogs received bicyclol (25, 75, 225 mg/kg, 16.6, 50, 150 folds corresponding to the proposed therapeutic dose of bicyclol for patients) once a day for 6 mo except for Sunday. The body weight, food intake, urine and feces, blood picture, blood biochemical markers, and pathological examination of main organs were determined. Mutagenicity and teratogenicity were determined. Mutagenicity assay included Ames's test, chromosome aberration test in CHL cells and micronucleus test in mice. For the teratogenicity assay, pregnant Wistar rats weighing 200-250 g were treated with 0.2, 1.0 g/kg bicyclol once daily from the 7th d of gestation for 10 d. RESULTS: The oral LD(50) of bicyclol was over 5 g/kg in mice and rats. No noticeable alterations in subacute and chronic toxicity of rats and dogs were demonstrated. No mutagenicity and teratogenicity of bicyclol were found. CONCLUSION: Bicyclol has no detectable chronic toxicity as well as mutagenicity and teratogenicity in animals.

Animals↗

PubMed2005

[Phenotype and function of myeloid dendritic cells pulsed with hepatitis B virus antigens in patients with HBV-associated hepatocellular carcinoma].

OBJECTIVE: To investigate the characteristics of phenotype and function of myeloid dendritic cells (mDCs) pulsed with HBV antigens derived from HBV-associated hepatocellular carcinoma (HCC) patients. METHODS: Peripheral blood mononuclear cells (PBMCs) were collected, using blood cell separator, from 21 primary HCC patients and 4 healthy donors. mDCs were propagated in serum-free AIM-V medium in the presence of cytokine cocktail, and pulsed with HBcAg or HBsAg. After 9 days' incubation, the phenotypic patterns of mDC were characterized by flow cytometry and the levels of IL-10 and IL-12 produced by mDCs were analyzed by ELISA. Autologous T cells proliferation stimulated by mDC was tested by non-radioactive cell proliferation assay kit. RESULTS: The expression rates of CD80, CD86, CD40, and HLA-DR in the mDCs pulsed with HBcAg were 55% +/- 26%, 80% +/- 13%, 70% +/- 13% and 73% +/- 24% respectively, significantly higher than those of the control group (29% +/- 25%, 35% +/- 18%, 44% +/- 26% and 45% +/- 23% respectively, all P < 0.05). Among the expression rates of surface molecules of the mDCs pulsed with HBsAg only the expression rate of HLA-DR was significantly higher than that of the un-pulsed mDCs (63% +/- 15% vs 45% +/- 23%, P < 0.05). T cell proliferation assay revealed an impaired allostimulatory capacity of mDCs in HCC and the stimulatory capacity of the mDCs pulsed with HBcAg to induce proliferation of autologous T cells was more powerful than that pulsed with HBsAg (P < 0.05). The levels of IL-10 and IL-12 produced by the mDCs pulsed with HBsAg were (35 pg/ml +/- 9 pg/ml and 135 pg/ml +/- 63 pg/ml respectively, both significantly lower than those pulsed with HBcAg (236 pg/ml +/- 95 pg/ml and 733 pg/ml +/- 212 pg/ml respectively, both P < 0.05). CONCLUSION: Pulsation of mDCs in vitro by HBcAg or HBsAg enhance the expression of CD80, CD86, CD40, and HLA-DR, and increase the ability of mDCs to stimulate the proliferation of autologous T lymphocytes.

Adult↗

PubMed2005

Chaperone-like activity of beta-casein.

The caseins are major components of milk for most mammals and are secreted as large colloidal aggregates termed micelles. They have less ordered secondary and tertiary structures in comparison with typical globular proteins. In this work, beta-casein, a member of the casein family, has been demonstrated to exhibit chaperone-like activity, being able to suppress the thermal and chemical aggregation of such substrate proteins as insulin, lysozyme, alcohol dehydrogenase, and catalase by forming stable complexes with the denaturing substrate proteins. Meanwhile, beta-casein was found to not only prevent aggregation of the substrate proteins, but also solubilize the protein aggregates already formed. Data also show that beta-casein exhibits a higher chaperone-like activity than alpha-casein, likely due to the difference in the number of proline residues present and/or in the extent of exposed hydrophobic surfaces. The implications for their in vivo functions of the caseins, based on their exhibiting such in vitro chaperone-like activities, are discussed.

Alcohol Dehydrogenase↗

PubMed2005

High throughput proteome screening for biomarker detection.

Mass spectrometry-based quantitative proteomics has become an important component of biological and clinical research. Current methods, while highly developed and powerful, are falling short of their goal of routinely analyzing whole proteomes mainly because the wealth of proteomic information accumulated from prior studies is not used for the planning or interpretation of present experiments. The consequence of this situation is that in every proteomic experiment the proteome is rediscovered. In this report we describe an approach for quantitative proteomics that builds on the extensive prior knowledge of proteomes and a platform for the implementation of the method. The method is based on the selection and chemical synthesis of isotopically labeled reference peptides that uniquely identify a particular protein and the addition of a panel of such peptides to the sample mixture consisting of tryptic peptides from the proteome in question. The platform consists of a peptide separation module for the generation of ordered peptide arrays from the combined peptide sample on the sample plate of a MALDI mass spectrometer, a high throughput MALDI-TOF/TOF mass spectrometer, and a suite of software tools for the selective analysis of the targeted peptides and the interpretation of the results. Applying the method to the analysis of the human blood serum proteome we demonstrate the feasibility of using mass spectrometry-based proteomics as a high throughput screening technology for the detection and quantification of targeted proteins in a complex system.

Automation↗

PubMed2005

Dual-level direct dynamics studies on the reaction Cl + CHBr(2)Cl.

Theoretical investigations are carried out on the multichannel reaction CHBr(2)Cl + Cl by means of direct dynamics methods. The minimum energy path (MEP) is obtained at the BH&H-LYP/6-311G(d,p) level, and energetic information is further refined at the CCSD(T)/6-311+G(2df,2p) (single-point) level. The rate constants for three reaction channels, H-abstraction, Br-abstraction, and Cl-abstraction, are calculated by using the improved canonical variational transition state theory (ICVT) incorporating with the small-curvature tunneling (SCT) correction. The theoretical overall rate constants are in good agreement with the available experimental data and are found to be k=2.58 x 10(-15) T(1.18) exp(-861.17/T) cm(3)molecule(-1)s(-1) over the temperature range 200--2400 K. For the title reaction, H-abstraction reaction channel is the major channel at the lower temperatures, while as the temperature increases, the contribution of Br-abstraction reaction channel should be taken into account. At 2180 K, the rate constants of these two pathways are equal. Cl-abstraction reaction channel is minor channel over the whole temperature region.

Journal Article↗

PubMed2005

Chloride channels in the small intestinal cell line IEC-18.

Small intestinal crypt cells play a critical role in modulating Cl- secretion during digestion. The types of Cl- channels mediating Cl- secretion in the small intestine was investigated using the intestinal epithelial cell line, IEC-18, which was derived from rat small intestine crypt cells. In initial radioisotope efflux studies, exposure to forskolin, ionomycin or a decrease in extracellular osmolarity significantly increased 36Cl efflux as compared to control cells. Whole cell patch clamp techniques were subsequently used to examine in more detail the swelling-, Ca2+-, and cAMP-activated Cl- conductance. Decreasing the extracellular osmolarity from 290 to 200 mOsm activated a large outwardly rectifying Cl- current that was voltage-independent and had an anion selectivity of I- > Cl-. Increasing cytosolic Ca2+ by ionomycin activated whole cell Cl- currents, which were also outwardly rectifying but were voltage-dependent. The increase in intracellular Ca2+ levels with ionomycin was confirmed with fura-2 loaded IEC-18 cells. A third type of whole cell Cl- current was observed after increases in intracellular cAMP induced by forskolin. These cAMP-activated Cl- currents have properties consistent with cystic fibrosis transmembrane regulator (CFTR) Cl- channels, as the currents were blocked by glibenclamide or NPPB but insensitive to DIDS. In addition, the current-voltage relationship was linear and had an anion selectivity of Cl- > I-. Confocal immunofluorescence studies and Western blots with two different anti-CFTR antibodies confirmed the expression of CFTR. These results suggest that small intestinal crypt cells express multiple types of Cl- channels, which may all contribute to net Cl- secretion.

Animals↗

PubMed2005

Human Plasma PeptideAtlas.

Peptide identifications of high probability from 28 LC-MS/MS human serum and plasma experiments from eight different laboratories, carried out in the context of the HUPO Plasma Proteome Project, were combined and mapped to the EnsEMBL human genome. The 6929 distinct observed peptides were mapped to approximately 960 different proteins. The resulting compendium of peptides and their associated samples, proteins, and genes is made publicly available as a reference for future research on human plasma.

Blood Proteins↗

PubMed2005

Deformable registration of diffusion tensor MR images with explicit orientation optimization.

In this paper we present a novel deformable registration algorithm for diffusion tensor (DT) MR images that enables explicit analytic optimization of tensor reorientation. The optimization seeks a piecewise affine transformation that divides the image domain into uniform regions and transforms each of them affinely. The objective function captures both the image similarity and the smoothness of the transformation across region boundaries. The image similarity enables explicit orientation optimization by incorporating tensor reorientation, which is necessary for warping DT images. The objective function is formulated in a way that allows explicit implementation of analytic derivatives to drive fast and accurate optimization using the conjugate gradient method. The optimal transformation is hierarchically refined in a subdivision framework. A comparison with affine registration for inter-subject normalization of 8 subjects shows that our algorithm improves the alignment of manually segmented white matter structures (corpus callosum and cortio-spinal tracts).

Algorithms↗