Biomedical subjects

Hui Zhang

Publications and source records attributed to Hui Zhang.

At least 343 records · Page 19Linked to original sources

PubMed2003

[Effects of taking the pingzhi tablets on cellular infiltration in tissues of nasal polyps].

OBJECTIVE: To assess the effects of taking the "Pingzhi Tablets" on infiltration of inflammatory in tissues of chronic sinusitis and nasal polyps. METHOD: Nasal polyps from taking the "Pingzhi Tablets" treated patients (40 cases) and untreated patients (40 cases) were investigated. The samples were stained by HE and SABC-AP immunohistochemical methods. RESULT: Compared with untreated polyps, the polyps treated by taking the "Pingzhi Tablets" contained significantly lower tissue densities of CD 11b+, CD7+ positive cells. Although the densities of CD 19+ positive cells were lower in treated polyps, the differences were not statistically significant. CONCLUSION: The findings demonstrated tissue effects of treatment with taking "Pingzhi Tablets" and the treatment was effective in suppressing the inflammatory cell infiltration.

Adult↗

PubMed2003

A correlative study between prevalence of chondromalacia patellae and sports injury in 4068 students.

OBJECTIVE: To study the prevalence of chondromalacia patella among college students and the correlation with sports injury. METHODS: 354 students from gymnastic department and 429 from nongymnastic department with knee joint pain were selected. 184 students from gymnastic department and 342 from nongymnastic department were checked randomly by a surgeon. 77 patients (37 males, 40 females) from gymnastic department and 119 patients (62 males, 57 females) from nongymnastic department were diagnosed as chondromalacia patellae. The amount of exercise and the occurrence of sports injury were investigated in each student. All data were analyzed with SPSS 10.0 statistical software. RESULTS: The prevalence of chondromalacia patella was 20.1% in female students and 11.6% in male students from gymnastic department, and 5.61% in female students and 4.92% in male students from nongymnastic department. The amount of exercise and the occurrence of sports injury to the knee joint in students from gymnastic department were greater than those from nongymnastic department. CONCLUSIONS: In both female and male students, the prevalence of chondromalacia patella is higher in gymnastic department than nongymnastic department. Sports injury is an important cause of chondromalacia patella.

Adolescent↗

PubMed2003

[Therapeutic effect of secretive endostatin eukaryotic expressing plasmid on mouse hepatoma].

OBJECTIVE: To construct and express secretive endostatin eukaryotic plasmid for treatment of hepatoma. METHODS: Mouse Igk signal peptide sequence was synthesized and cloned into pcDNA3.1 with endostatin gene. The supernant of BHK-21 transfected with recombinant was used to culture ECV304. The proliferation of latter was evaluated by MTT assay. H22 was inoculated intramusclely, then naked DNA of endostatin plasmid was injected into the inoculation site. Tumors were dissected and weighted after treatments. All data was analyzed by SPSS10.0. RESULTS: The supernant of BHK-21 transfected with recombinant can inhibit the proliferation of ECV304 by 29.2%. Tumor weight lighter after injected with naked pSecES (1.34 g+/-0.96g) compared with naked pcDNA3.1 (2.70g+/-0.82g) and saline (3.73g+/-1.41g). CONCLUSION: The endostatin eukaryotic plasmid was constructed and it can be used for gene therapy on hepatoma.

Animals↗

PubMed2003

[Study on the fingerprints of Achyranthes bidentata Bl. by HPLC/UV/MS].

OBJECTIVE: To establish the fingerprints of Achyranthes bidentata Bl. by HPLC/UV/MS. METHOD: Separation was performed on Aglient Zorbax SB-C18 column. Gradient elute was performed by the mobile phase consisting of methanol and 0.1% formic acid-water with the flow rate of 1.0 ml/min. RESULT: Perfect fingerprints were obtained which can be used for the evaluation of Achyranthes bidentata Bl. Four common peaks were confirmed in fingerprints. Three compounds were elucidated as 5-hydroxymethyl furaldehyde, ecdysterone, inokosterone by HPLC/MS. CONCLUSION: The method can be applied to the quality control of Achyranthes bidentata Bl.

Achyranthes↗

PubMed2003

[The introduction of chloroplast gene engineering].

Chloroplast is a kind of special cell organ in plant cells.Since 1988,Scientists have realized its advantages in plant gene engineering.It's high efficient expression and safety made it been attached more and more importance to. This paper introduces the chloroplast transformation,including its advantages,methods,uses and defects.

English Abstract↗

PubMed2003

[Study on the culture of crown gall from Panax quinquefolium and the prouction of its secondary metabolites--Ginsenosides Re and Rg1].

It was clearly demonstrated that T-DNA of Agrobacterium tumefeciens Ti plasmid was integrated into the cells of crown gall in our experiment. This paper reported the influences of some kinds of physical-chemistry factors on the growth of crown gall of Panax quinquefolium and the production of its main active compounds--ginsenoside Re and ginsensoside Rg1. The results showed that White medium was the best one for ginsensoside Rg1 accumulation (0.095%) among the six media, but ginsensoside Re accumulation (0.194%) was the highest on the MS medium; The highest contents of ginsensoside Re (0.147%) and ginsensoside Rg1 (0.061%) were on the culture 36d and 32d after innoculum respectively; The optimum pH was 5.6 for ginsensoside Rg1 synthesis(0.054%), and 5.8 for ginsensoside Re synthesis(0. 184% ); The contents of ginsensoside Re and ginsensoside Rg1 was the highest in the inoculum of 4 g and 2 g/flask (FW) respectively. The result also indicated that the concentration of inositol in 0.05 g/L could obviously promote ginsensoside Re synthesis (0.182%), and in 0.30 g/L for ginsensoside Rg1 (0.055%).

Agrobacterium tumefaciens↗

PubMed2003

[Fusion expression of the ORF5 gene of porcine reproductive and respiratory syndrome virus in insect cells].

A 0.75kb fragment containing the complete cDNA of glutathione-S-transferase (GST) and a modified thrombin cleavage sites were amplified and cloned into pFastBacl, the donor plasmid of Bac-to-Bac baculovirus expression systems, downstream from the polyhedrin promoter (pPolh), resulting in the GST fusion transposition plasmid pFGST. After transposition and transfection, SDS-PAGE analysis showed that the developed GST fusion expression system can highly express GST. The signal sequences of the major structural protein gene ORF5 of porcine reproductive and respiratory syndrome virus (PRRSV) strain YA was removed by PCR and the truncated ORF5 gene was inserted into pFGST and fused with GST to generate the transposition plasmid expressing GST-ORF5 fusion protein. The recombinant baculovirus rvBacGST53 was obtained by transposition and transfection. GST-ORF5 fusion protein was identified by SDS-PAGE and Western blot. The fusion protein is 45kD and is specific to the monoclonal antibody against the E protein of PRRSV. The fusion protein was directly injected into mice and the anti-sera can react with the PRRSV-infected MARC-145 cells by indirect immunofluorescent assay (IFA), indicating that the fusion protein have better immunogenicity.

Animals↗

PubMed2002

Potent suppression of viral infectivity by the peptides that inhibit multimerization of human immunodeficiency virus type 1 (HIV-1) Vif proteins.

Virion infectivity factor (Vif) is essential for the replication of human immunodeficiency virus type 1 (HIV-1) in vivo, but its function remains uncertain. Recently, we have shown that Vif proteins are able to form multimers, including dimers, trimers, or tetramers. Because the multimerization of Vif proteins is required for Vif function in the viral life cycle, we propose that it could be a novel target for anti-HIV-1 therapeutics. Through a phage peptide display method, we have identified a set of 12-mer peptides containing a PXP motif that binds to HIV-1 Vif protein. These proline-enriched peptides potently inhibited the Vif-Vif interaction in vitro. We have also screened a set of synthesized Vif peptides (15-mer), which covers all the amino acids of the HIV-1 Vif protein sequence, for their ability to inhibit the Vif-Vif interaction in vitro. We demonstrated that Vif-derived proline-enriched peptides that contain the (161)PPLP(164) domain are able to inhibit the Vif-Vif interaction. Conversely, the deletion of the (161)PPLP(164) domain of Vif protein will significantly impair the capability of Vif proteins to interact with each other, indicating that the (161)PPLP(164) domain plays a key role in Vif multimerization. All these results demonstrate that the proline-enriched peptides block the multimerization of Vif through interfering with the polyproline interfaces of Vif formed by (161)PPLP(164) domain. Moreover, these peptides which inhibit the Vif-Vif interaction in vitro potently inhibit HIV-1 replication in the "nonpermissive" T-cells. We propose that this study starts a novel strategy to develop structural diverse inhibitors of Vif such as peptidomimetics or small organic molecules.

Amino Acid Sequence↗

PubMed2002

Intensification and stimulation therapy for human immunodeficiency virus type 1 reservoirs in infected persons receiving virally suppressive highly active antiretroviral therapy.

Highly active antiretroviral therapy (HAART) has led to significant changes in mortality and morbidity in the human immunodeficiency virus type 1 (HIV-1) epidemic. Nevertheless, because of molecular mechanisms of viral persistence, HAART does not eradicate HIV-1. Didanosine and hydroxyurea were added to the antiretroviral regimens of 3 HIV-1-infected men who were receiving stable HAART and who had HIV-1 RNA levels <50 copies/mL at the initiation of the study protocol, as a novel intensification to attack cryptic viral replication; low-dose OKT3 was then administered, followed by a course of interleukin-2, to stimulate latent provirus. Replication-competent virus was undetectable after treatment, and plasma viral RNA was either undetectable or <5 copies/mL. In trial periods during which no antiretroviral therapy was administered, the patients developed plasma viral rebound. This translational approach combines novel intensification and stimulation therapy to deplete residual HIV-1 reservoirs. Additional experimental approaches must be developed if HIV-1 eradication is to become possible in patients receiving virally suppressive HAART.

Adult↗

PubMed2002

The identification of vesicular glutamate transporter 3 suggests novel modes of signaling by glutamate.

Quantal release of the principal excitatory neurotransmitter glutamate requires a mechanism for its transport into secretory vesicles. Within the brain, the complementary expression of vesicular glutamate transporters (VGLUTs) 1 and 2 accounts for the release of glutamate by all known excitatory neurons. We now report the identification of VGLUT3 and its expression by many cells generally considered to release a classical transmitter with properties very different from glutamate. Remarkably, subpopulations of inhibitory neurons as well as cholinergic interneurons, monoamine neurons, and glia express VGLUT3. The dendritic expression of VGLUT3 by particular neurons also indicates the potential for retrograde synaptic signaling. The distribution and subcellular location of VGLUT3 thus suggest novel modes of signaling by glutamate.

Amino Acid Transport Systems, Acidic↗

PubMed2002

Isolating the promoter of a stress-induced gene encoding betaine aldehyde dehydrogenase from the halophyte Atriplex centralasiatica Iljin.

The betaine aldehyde dehydrogenase (AcBADH) gene of the halophyte Atriplex centralasiatica Iljin is induced by drought, salinity, cold stress and abscisic acid, in parallel with an increase in betaine level. In order to study the molecular basis of its expression and to obtain an effective stress-induced promoter, the 5' flanking region of betaine aldehyde dehydrogenase gene (about 1.2 kb) was isolated from the halophyte A. centralasiatica Iljin by screening the genomic library. The transcription start site, which localized at 84 bases upstream of the start ATG, was determined by primer extension and 5'-RACE method. To investigate the molecular mechanism of the stress-induced gene regulation, the AcBADH promoter-beta-glucuronidase chimeric gene constructs containing six deletions were introduced into tobacco by Agrobacterium-mediated transformation. The AcBADH 5'-flanking region, a promoter strongly induced by salt stress, contains two salt-responsive enhancer regions localized between -1115 and -890, -462 and -230 and one silencer region between -890 and -641.

Abscisic Acid↗

PubMed2002

Phosphoprotein analysis using antibodies broadly reactive against phosphorylated motifs.

The substrates of most protein kinases remain unknown because of the difficulty tracing signaling pathways and identifying sites of protein phosphorylation. Here we describe a method useful in detecting subclasses of protein kinase substrates. Although the method is broadly applicable to any protein kinase for which a substrate consensus motif has been identified, we illustrate here the use of antibodies broadly reactive against phosphorylated Ser/Thr-motifs typical of AGC kinase substrates. Phosphopeptide libraries with fixed residues corresponding to consensus motifs RXRXXT*/S* (Akt motif) and S*XR (protein kinase C motif) were used as antigens to generate antibodies that recognize many different phosphoproteins containing the fixed motif. Because most AGC kinase members are phosphorylated and activated by phosphoinositide-dependent protein kinase-1 (PDK1), we used PDK1-/- ES cells to profile potential AGC kinase substrates downstream of PDK1. To identify phosphoproteins detected using the Akt substrate antibody, we characterized the antibody binding specificity to generate a specificity matrix useful in predicting antibody reactivity. Using this approach we predicted and then identified a 30-kDa phosphoprotein detected by both Akt and protein kinase C substrate antibodies as S6 ribosomal protein. Phosphospecific motif antibodies offer a new approach to protein kinase substrate identification that combines immunoreactivity data with protein data base searches based upon antibody specificity.

Amino Acid Motifs↗

PubMed2002

Cysteine string protein interacts with and modulates the maturation of the cystic fibrosis transmembrane conductance regulator.

The cystic fibrosis transmembrane conductance regulator (CFTR) is a cAMP-regulated chloride channel whose phosphorylation regulates both channel gating and its trafficking at the plasma membrane. Cysteine string proteins (Csps) are J-domain-containing, membrane-associated proteins that have been functionally implicated in regulated exocytosis. Therefore, we evaluated the possibility that Csp is involved in regulated CFTR trafficking. We found Csp expressed in mammalian epithelial cell lines, several of which express CFTR. In Calu-3 airway cells, immunofluorescence colocalized Csp with calnexin in the endoplasmic reticulum and with CFTR at the apical membrane domain. CFTR coprecipitated with Csp from Calu-3 cell lysates. Csp associated with both core-glycosylated immature and fully glycosylated mature CFTRs (bands B and C); however, in relation to the endogenous levels of the B and C bands expressed in Calu-3 cells, the Csp interaction with band B predominated. In vitro protein binding assays detected physical interactions of both mammalian Csp isoforms with the CFTR R-domain and the N terminus, having submicromolar affinities. In Xenopus oocytes expressing CFTR, Csp overexpression decreased the chloride current and membrane capacitance increases evoked by cAMP stimulation and decreased the levels of CFTR protein detected by immunoblot. In mammalian cells, the steady-state expression of CFTR band C was eliminated, and pulse-chase studies showed that Csp coexpression blocked the conversion of immature to mature CFTR and stabilized band B. These results demonstrate a primary role for Csp in CFTR protein maturation. The physical interaction of this Hsc70-binding protein with immature CFTR, its localization in the endoplasmic reticulum, and the decrease in production of mature CFTR observed during Csp overexpression reflect a role for Csp in CFTR biogenesis. The documented role of Csp in regulated exocytosis, its interaction with mature CFTR, and its coexpression with CFTR at the apical membrane domain of epithelial cells may reflect also a role for Csp in regulated CFTR trafficking at the plasma membrane.

Animals↗

PubMed2002

The COP9 signalosome inhibits p27(kip1) degradation and impedes G1-S phase progression via deneddylation of SCF Cul1.

The COP9 signalosome (CSN) is a conserved protein complex with homologies to the lid subcomplex of the 26S proteasome. It promotes cleavage of the Nedd8 conjugate (deneddylation) from the cullin component of SCF ubiquitin ligases. We provide evidence that cullin neddylation and deneddylation is highly dynamic, that its equilibrium can be effectively modulated by CSN, and that neddylation allows Cul1 to form larger protein complexes. CSN2 integrates into the CSN complex via its C-terminal region and its N-terminal half region is necessary for direct interaction with Cul1. The polyclonal antibodies against CSN2 but not other CSN subunits cause accumulation of neddylated Cul1/Cul2 in HeLa cell extract, indicating that CSN2 is essential in cullin deneddylation. Further, CSN inhibits ubiquitination and degradation of the cyclin-dependent kinase inhibitor p27(kip1) in vitro. Microinjection of the CSN complex impeded the G1 cells from entering the S phase. Moreover, anti-CSN2 antibodies negate the CSN-dependent p27 stabilization and the G1/S blockage, suggesting that these functions require the deneddylation activity. We conclude that CSN inhibits SCF ubiquitin ligase activity in targeting p27 proteolysis and negatively regulates cell cycle at the G1 phase by promoting deneddylation of Cul1.

Animals↗

PubMed2002

Phosphorylation of the myosin regulatory light chain plays a role in motility and polarity during Dictyostelium chemotaxis.

The myosin regulatory light chain (RLC) of Dictyostelium discoideum is phosphorylated at a single serine site in response to chemoattractant. To investigate the role of the phosphorylation of RLC in both motility and chemotaxis, mutants were generated in which the single phosphorylatable serine was replaced with a nonphosphorylatable alanine. Several independent clones expressing the mutant RLC in the RLC null mutant, mlcR(-), were obtained. These S13A mutants were subjected to high resolution computer-assisted motion analysis to assess the basic motile behavior of cells in the absence of a chemotatic signal, and the chemotactic responsiveness of cells to the spatial, temporal and concentration components of natural cAMP waves. In the absence of a cAMP signal, mutant cells formed lateral pseudopods less frequently and crawled faster than wild-type cells. In a spatial gradient of cAMP, mutant cells chemotaxed more efficiently than wild-type cells. In the front of simulated temporal and natural waves of cAMP, mutant cells responded normally by suppressing lateral pseudopod formation. However, unlike wild-type cells, mutant cells did not lose cellular polarity at the peak and in the back of either wave. Since depolarization at the peak and in the descending phase of the natural wave is necessary for efficient chemotaxis, this deficiency resulted in a decrease in the capacity of S13A mutant cells to track natural cAMP waves relayed by wild-type cells, and in the fragmentation of streams late in mutant cell aggregation. These results reveal a regulatory pathway induced by the peak and back of the chemotactic wave that alters RLC phosphorylation and leads to cellular depolarization. We suggest that depolarization requires myosin II rearrangement in the cortex facilitated by RLC phosphorylation, which increases myosin motor function.

Animals↗

PubMed2002

Isolation of a genomic clone containing the promoter region of the human ATP binding cassette (ABC) transporter, ABCB6.

We previously reported on the isolation of a new rat ATP binding cassette (ABC) transporter, ABCB6. We now report the isolation of the full-length cDNA and genomic clones containing the human ABCB6 gene. ABCB6 is 100% identical to the cloned MTABC3 human ABC transporter and contains the typical ABC signature, Walker A and B motifs. We found that HuABCB6 is expressed at low levels in normal human liver. We found that ABCB6 was overexpressed in human hepatocellular carcinomas compared to paired surrounding non-malignant tissue. We found that there was no difference in ABCB6 gene copy between human liver cancer and its paired non-malignant tissue. Because HuABCB6 was overexpressed in human cancers compared to peri-tumoral tissue in the absence of gene amplification, transcriptional regulation may play an important role in its expression. Therefore, we isolated a 14 kb genomic DNA clone containing the HuABCB6 promoter and 5'-flanking region. The 5'-flanking region contains a CpG island, lacks an appropriately positioned TATA element and contains a number of putative transcription factor binding sites. Two transcription start sites were identified by S1 nuclease mapping at -274 and -296 bp from the start codon. Transient transfection of the HuABCB6 promoter constructs (HuABCB6/1.68, 1.39, 1.13, 0.90, 0.52) containing the luciferase reporter gene resulted in a 1100-2300-fold increase in luciferase activity compared to the empty vector control whereas HuABCB6/1.68 subcloned in the reverse orientation resulted in no activity. We observed a significant decrease in luciferase activity with the promoter constructs, HuABCB6/0.25, 0.15 and 0.06, which indicates that an orientation-dependent functional promoter is contained within our previously predicted promoter region of -315 bp to -565 bp as deletion of this 250 bp sequence resulted in a loss of promoter activity.

ATP-Binding Cassette Transporters↗

PubMed2002

Oxidative stress increases internal calcium stores and reduces a key mitochondrial enzyme.

Fibroblasts from patients with genetic and non-genetic forms of Alzheimer's disease (AD) show many abnormalities including increased bombesin-releasable calcium stores (BRCS), diminished activities of the mitochondrial alpha-ketoglutarate dehydrogenase complex (KGDHC), and an altered ability to handle oxidative stress. The link between genetic mutations (and the unknown primary event in non-genetic forms) and these other cellular abnormalities is unknown. To determine whether oxidative stress could be a convergence point that produces the other AD-related changes, these experiments tested in fibroblasts the effects of H(2)O(2), in the presence or absence of select antioxidants, on BRCS and KGDHC. H(2)O(2) concentrations that elevated carboxy-dichlorofluorescein (c-H(2)DCF)-detectable ROS increased BRCS and decreased KGDHC activity. These changes are in the same direction as those in fibroblasts from AD patients. Acute treatments with the antioxidants Trolox, or DMSO decreased c-H(2)DCF-detectable ROS by about 90%, but exaggerated the H(2)O(2)-induced increases in BRCS by about 4-fold and did not alter the reduction in KGDHC. Chronic pretreatments with Trolox more than doubled the BRCS, tripled KGDHC activities, and reduced the effects of H(2)O(2). Pretreatment with DMSO or N-acetyl cysteine diminished the BRCS and either had no effect, or exaggerated the H(2)O(2)-induced changes in these variables. The results demonstrate that BRCS and KGDHC are more sensitive to H(2)O(2) derived species than c-H(2)DCF, and that oxidized derivatives of the antioxidants exaggerate the actions of H(2)O(2). The findings support the hypothesis that select abnormalities in oxidative processes are a critical part of a cascade that leads to the cellular abnormalities in cells from AD patients.

Acetylcysteine↗

PubMed2002

Immunologic quantitation of the carcinoma specific human carcinoma antigen in clinical samples.

BACKGROUND: Based on the cross-reactivity of the human carcinoma antigen, HCA, with epiglycanin, a mouse mammary carcinoma cell surface glycoprotein, HCA has been detected in the tissue and blood of patients with every type of epithelium-derived cancer tested. METHODS: Competitive binding assays utilized the following antiepiglycanin antibodies: a polyclonal rabbit antiserum (immunoglobulin [Ig] G and IgM) in a radioimmunoassay; mouse monoclonal antibodies (Ab-1, IgM) on immunoplates; anti-idiotypic (Ab-2) and anti-anti-idiotypic (Ab-3) monoclonal antibodies (both IgG) from spleen cells of C57BL mice immunized, respectively, with Ab-1 and Ab-2, and utilized on immunoplates. IgG and IgM antibodies were evaluated for their ability to detect HCA and to distinguish between the blood of patients with, or without, carcinomas. RESULTS: Assays with the rabbit antiserum distinguished plasmas of metastatic breast carcinoma patients from those of patients with benign breast disease with a sensitivity of approximately 93% (specificity 90%). Antiepiglycanin IgM monoclonal antibodies (i.e., AE3) showed high specificity and sensitivity (> 90%) with sera from advanced carcinoma patients when compared with normal sera. The IgG anti-anti-idiotypic (Ab-3) monoclonal antibodies (i.e., AF2), which bind the same epitope as Ab-1, appear to possess less nonspecific binding capacity, however, than the Ab-1 (IgM) antibodies. Anti-Ab-1 (i.e., C8F2) anti-idiotypic monoclonal antibodies, which bear an idiotope equivalent to the epitope present in epiglycanin and the HCA, demonstrated greater consistency as a standard calibrator and for coating wells than epiglycanin. CONCLUSIONS: The concentration of the HCA in the body fluids of patients with carcinomas may be accurately determined by competitive binding assays. It is suggested that the use of anti-idiotypic antibodies (IgG), rather than epiglycanin/HCA, and Ab-3 anti-anti-idiotypic antibodies (IgG), rather than Ab-1 (IgM), will improve the consistency, as well as the sensitivity and specificity, of the assay.

Adult↗