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Biomedical subjects

Q Zhou

Publications and source records attributed to Q Zhou.

At least 37 records · Page 2Linked to original sources
PubMed2005

Peripheral B lymphocyte beta1,3-galactosyltransferase and chaperone expression in immunoglobulin A nephropathy.

PURPOSE: Aberrant O-glycosylation of serum IgA(1) is presumed to be one of the main pathogenesis of immunoglobulin A nephropathy (IgAN). beta1,3-galactosyltransferase (beta1,3GT), whose activity requires coexistence of a specific chaperone, is the main enzyme which participate in the glycosylation process. The current study was carried out to elucidate the expression level of beta1,3GT (C1GALT1) and its chaperone (Cosmc) in IgAN, and their relationships with clinical features as well as IgA glycosylation level. DESIGN, SETTING AND SUBJECTS: Forty-one patients with IgAN, 21 patients with non-IgAN glomerulonephritis and 26 normal controls were included in the present study. Peripheral B lymphocytes were isolated, and then expression level of C1GALT1 and Cosmc were quantitatively measured by real-time reverse transcriptase polymerase chain reaction (RT-PCR). Serum IgA level and glycosylation level were determined by enzyme-linked immunosorbent assay (ELISA) and VV lectin-binding method. Correlation analysis was performed between C1GALT1/Cosmc expression levels and clinical manifestations (severe proteinuria, renal dysfunction, gross haematuria). RESULTS: B-lymphocyte Cosmc gene expression level was significantly lower in IgAN patients than that of normal control and non-IgAN patients (P<0.05), whilst no apparent disparity was observed in C1GALT1 expression level. Cosmc expression showed a negative correlation with IgA O-glycosylation level indicated by VV lectin-binding assay. Statistical analysis also indicated that the level of Cosmc expression was negatively correlated with severe proteinuria (P<0.05) instead of gross haematuria (P>0.05). CONCLUSION: These data suggested that the aberrant IgA O-glycosylation in IgAN was resulted from a downregulation of beta1,3GT chaperone (Cosmc) expression in B lymphocyte, which is closely associated with clinical characteristics of the disease. This downregulation might be one of the fundamental pathogenic abnormalities in IgAN.

Adult↗
PubMed2005

The inhibitory effect of altered collagen II peptide on HLA-DRB1-restricted T-cell activation.

It has been known that rheumatoid arthritis (RA)-associated antigenic peptides CII263-272 are coupled with human leucocyte antigen (HLA)-DRB1 and recognized by T-cell receptor (TCR), which in turn induced T-cell proliferation and pathogenesis of RA. Non-T-cell-stimulating type II collagen (CII) peptides might be generated by removing the amino acids responsible for TCR contact and keeping the HLA-DR-binding residues intact. In this study, a panel of altered CII peptides (APs) with consecutive or single substitutions of the TCR-contacting residues were synthesized. Through peptide binding and T-cell activation assays, we demonstrated that altered CII263-272 peptides with substitution of the TCR-contacting residues did not or barely induced T-cell activation; one of the best non-T-cell-stimulating peptide AP268-270 inhibited the binding of wild-type CII263-272 to HLA-DR1 and T-cell activation triggered by wild-type CII263-272 and HA306-318 in a dose-response manner. These data suggest that removal of the TCR-contacting residues of CII263-272 leads to HLA-DRB1 binding and low T-cell-stimulating peptides, which could potentially inhibit the T-cell response induced by HLA-DRB1-binding antigenic peptides.

Amino Acid Sequence↗
PubMed2005

Melanoma inhibitor of apoptosis protein is expressed differentially in melanoma and melanocytic naevus, but similarly in primary and metastatic melanomas.

BACKGROUND: Malignant melanoma is highly resistant to current treatments. The inhibitor of apoptosis protein (IAP) family member, melanoma IAP (ML-IAP), is overexpressed in some melanoma cell lines, rendering them resistant to apoptotic signals. Targeting ML-IAP is a promising approach to treating melanoma. However, the status of ML-IAP expression in human melanoma tissues and the difference in expression between melanoma and melanocytic naevus are not known. AIMS: To investigate these issues. METHODS: ML-IAP expression in 48 archived patient samples (34 melanomas and 14 dermal naevi) was assessed by immunohistochemistry and by in situ hybridisation and reverse transcription polymerase chain reaction (RT-PCR) assays developed for the study. RESULTS: Expression of ML-IAP was detected in 47.6-70.6% (10 of 21 to 24 of 34) of the melanomas, varying with detection methods. The expression rate in melanoma was much higher than that in melanocytic naevus (10.0-21.4%; one of 10 to three of 14). No significant difference was seen between primary and secondary melanomas. ML-IAP expression rates assessed by the three methods were in agreement. CONCLUSIONS: The ML-IAP expression rate in archived melanoma tissues is around 50-70%, with no difference between primary and secondary melanomas. A small number of dermal naevi ( approximately 20%) also expressed ML-IAP.

Adaptor Proteins, Signal Transducing↗
PubMed2004

HAb18G/CD147-mediated calcium mobilization and hepatoma metastasis require both C-terminal and N-terminal domains.

HAb18G/CD147 is a heavily glycosylated protein containing two immunoglobulin superfamily domains. Our previous studies have indicated that overexpression of HAb18G/CD147 enhances metastatic potentials in human hepatoma cells by disrupting the regulation of store-operated Ca2+ entry by nitric oxide (NO)/cGMP. In the present study, we investigated the structure-function of HAb18G/CD147 by transfecting truncated HAb18G/CD147 fragments into human 7721 hepatoma cells. The inhibitory effect of HAb18G/CD147 on 8-bromo-cGMP-regulated thapsigargin-induced Ca2+ entry was reversed by the expression of either C or N terminus truncated HAb18G/CD147 in T7721deltaC and T7721deltaN cells, respectively. The potential effect of HAb18G/CD147 on metastatic potentials, both adhesion and invasion capacities, of hepatoma cells was abolished in T7721deltaC cells, but not affected in T7721deltaN cells. Release and activation of matrix metalloproteinases (MMPs), MMP-2 and MMP-9, were found to be enhanced by the expression of HAb18G/CD147, and this effect was abolished by both truncations. Thapsigargin significantly enhanced release and activation of MMPs (MMP-2 and MMP-9) in non-transfected 7721 cells, and this effect was negatively regulated by SNAP. However, no effects of thapsigargin or SNAP were observed in T7721 cells, and expression of HAb18G/CD147 enhanced secretion and activation of MMPs at a stable and high level. Taken together, these results suggest that both ectodomain and intracellular domains of HAb18G/CD147 are required to mediate the effect of HAb18G/CD147 on the secretion and activation of MMPs and metastasis-related processes in human hepatoma cells by disrupting the regulation of NO/cGMP-sensitive intracellular Ca2+ mobilization although each domain may play different roles.

Antigens, CD↗
PubMed2004

Root growth inhibition and induction of DNA damage in soybean (Glycine max) by chlorobenzenes in contaminated soil.

The cytotoxic and genotoxic effects of 1,2,4-trichlorobenzene (TCB), chlorobenzene (CB), and hexachlorobenzene (HCB) on root growth and DNA strand breakage damage of soybean nuclei in the test soil were studied using the comet assay. Results indicated that the root growth was significantly inhibited, and DNA strand breaks and the comet tail in the root tip nuclei were both induced after 48 h exposure with TCB concentrations of 50, 100, 200, 300 microg g(-1) in the soil. DNA strand breakage was more sensitive to the TCB than the root growth. There was a significant dose-response relationship between the TCB exposure and DNA strand breakage in the soybean nuclei. Thus it is possible for DNA strand breakage to be used as a biomarker of soybean exposed to TCB contamination. Significant cytotoxic threshold concentration of the TCB exposure on the root growth inhibition was determined as 61 microg g(-1) in the soil. The toxicity of 100-1,000 microg g(-1) CB and HCB to the soybean seedlings in the soil were not observed after 48 h or longer exposure.

Cell Division↗
PubMed2004

Phytodegradation of extra heavy oil-based drill cuttings using mature reed wetland: an in situ pilot study.

Environmental contamination caused by extra heavy oil-based drill cuttings (DCs) is a major problem in the Liaohe Oilfield, northeastern China. To study the potential effectiveness of the mature reed wetland in removing extra heavy oil contained in drill cuttings, biodegradation of extra heavy oils and study of the effects on soil property and ecophysiological and quality indices of reeds were carried out in a 2-year in situ pilot experiment. In the wetland, four reed beds were used to treat drill cuttings in various loadings: 0 (control), 5, 20, and 40 kg/m(2), corresponding to 150, 600, and 1200 g/m(2) extra heavy oil hydrocarbons (HCs). The obtained results demonstrate that the mature reed wetland was effective at degrading extra heavy oils without extra fertilization. Removal efficiencies of reed bed 2 in the 0- to 80-cm soil profile increased with time, from 90.1% (first harvest season) to 95.8% (second harvest season). After 2 years, only 4.2% of the initial hydrocarbons residual was retained in the surface soil. There was no apparent adverse effects on the surface soil property during degradation of extra heavy oils and, actually, the deeper soil property and reed quality indices were improved at the end of the experiment. Phytotoxicity, resulting in reduction of reed yield, was observed in the most heavily treated beds in the first year. However, long-term reed yield recovered robustly. During the 2-year period, reed height and leaf number were slightly inhibited.

Biodegradation, Environmental↗
PubMed2004

A sterically stabilized immunolipoplex for systemic administration of a therapeutic gene.

A sterically stabilized immunolipoplex (TsPLP), containing an antitransferrin receptor single-chain antibody fragment (TfRscFv)-PEG molecule, has been developed to specifically and efficiently deliver a therapeutic gene to tumor cells. A postcoating preparation strategy was employed in which a DNA/lipid complex (lipoplex) was formed first and then sequentially conjugated with PEG and TfRscFv. The complex prepared by this method was shown to be superior in ability to deliver genes to tumor cells than when prepared by a common precoating strategy, in which DNA is mixed with TfRscFv-PEG conjugated liposome. Using prostate cancer cell line DU145, a comparison was made between the in vitro and in vivo gene delivery efficiencies of four complexes, Lipoplex (LP), PEG-Lipoplex (PLP), TfRscFv-PEG-Lipoplex (TsPLP) and our standard TfRscFv-Lipoplex (TsLP). In vitro, the order of transfection efficiency was TsLP>LP approximately TsPLP>PLP. However, in vivo the order of transfection efficiency, after systemic administration via the tail vein, was TsPLP>TsLP>LP or PLP with TsPLP-mediated exogenous gene expression in tumor being two-fold higher than when mediated by TsLP. This suggests that the in vitro transfection efficiency of TsPLP was not indicative of its in vivo efficiency. In addition, it was found that the level of exogenous gene expression in the tumor mediated by TsPLP was higher than that mediated by TsLP and did not decrease over the time. More importantly, high exogenous gene expression in tumor, but low expression in liver, was observed after an i.v. delivery of TsPLP carrying either the GFP reporter gene or the p53 gene, indicating that tumor preferential targeting was maintained by this complex in the presence of PEG. These findings show that incorporation of PEG into our targeted lipoplex results in a more efficient delivery of the complex to the tumor cells, possibly by inhibiting the first pass clearance observed with non-PEG containing liposomes. Therefore, these data demonstrate that TsPLP is a improvement over our previously established tumor targeted gene delivery complex for systemic gene therapy of cancer.

Animals↗
PubMed2004

Complex segregation analyses of bone mineral density in Chinese.

China has the largest population in the world; approximately 7% of the total population suffers from primary osteoporosis. Osteoporosis is mainly characterized by low bone mineral density (BMD). In the present study, familial correlation and segregation analyses for spine and hip BMDs have been undertaken for the first time in a Chinese sample composed of 401 nuclear families with a total of 1260 individuals. The results indicate a major gene of additive inheritance for hip BMD, whereas there is no evidence of a major gene influencing spine BMD. Significant familial residual effects are found for both traits, and heritability estimates (+/-SE) for spine and hip BMDs are 0.807(0.099) and 0.897(0.101), respectively. Sex and age differences in genotype-specific average BMD are also observed. This study provides the first evidence quantifying the high degree of genetic determination of BMD variation in the Chinese.

Age Factors↗
PubMed2004

A combined bioprocess for integrated removal of copper and organic pollutant from copper-containing municipal wastewater.

Heavy metal-containing wastewater is difficult to treat by most of the bioprocess due to its toxicity to microorganism in activated sludge. In this study, a combined bioprocess consisting of biosorption section that contained magnetite immobilized Pseudomonas putida 5-x cell as biosorbent followed by sequence batch reactor (SBR) was developed to treat Cu(2+)-containing municipal wastewater. The production techniques of Pseudomonas putida 5-x cell as biosorbent, such as optimal cell harvest period and cell pretreatment techniques were studied. Experimental results showed, considering both cell biomass and cell adsorption capacity to Cu(2+), 36 h is the optimal harvest period in the course of culturing Pseudomonas putida 5-x cells as biosorbent, and 0.1-0.3 mol L(-1) HCl is an optimal cell pretreating eluant to improve Cu(2+) adsorption capacity. The performances of the combined bioprocess for treating Cu(2+) containing wastewater were assessed. Experimental results showed that after treatment by biosorption, the Cu(2+) level in wastewater was reduced to level that did not inhibit COD removal efficiency of subsequent SBR activated sludge process, although it still affected the COD adsorption capacity of activated sludge. In terms of COD removal, the biosorption section was efficient for reducing Cu(2+) concentration to provide biodegradable wastewater for subsequent SBR activated sludge process.

Adsorption↗
PubMed2004

Contribution of cell outer membrane and inner membrane to Cu2+ adsorption by cell envelope of Pseudomonas putida 5-x.

The role of outer and inner membrane in the Cu2+ adsorption process by gram-negative bacterium Pseudomonas putida 5-x, which was isolated from local electroplating effluent with high Cu2+ accumulating capability, was studied. The results indicate that both the outer and inner membrane exhibited high Cu2+ adsorption capacity. Outer and inner membrane contributed about 30-35% and 20-25% parts of adsorption capacity in Cu2+ adsorption by cell envelope of Pseudomonas putida 5-x, respectively. The total contribution of outer and inner membrane to Cu2+ adsorption by cell envelope was much greater than that of peptidoglycan layer. The relatively high phospholipid content in the outer membrane might result in its greater heavy metal ions adsorption capacity. The Cu2+ binding process by the outer and inner membrane of Pseudomonas putida 5-x is the adsorption processes and can be described with Freundlich isotherms.

Adsorption↗
PubMed2004

Clustered basic residues within segment 484-510 of the factor VIIIa A2 subunit contribute to the catalytic efficiency for factor Xa generation.

Residues 484-510 of factor (F)VIIIa A2 subunit comprise a prominent epitope for inhibitor antibodies, suggesting that this region is critical for cofactor function. To address the role of this region in catalysis, FVIIIa forms were evaluated following conversion of conserved charged residues to Ala, either in clusters or individually. The two cluster mutants, Lys496Ala/Lys499Ala/Asp500Ala and Glu507Ala/Lys510Ala, were indistinguishable from wild type. The mutation Arg489Ala/Arg490Ala/Lys493Ala (489-3A) possessed near-normal affinity for FIXa and showed no effect on the Km for FX, but exhibited approximately 3-fold and approximately 30-fold reduced kcat values for FXase in the presence and absence of surface, respectively. However, the single-site mutants Arg489Ala, Arg490Ala and Lys493Ala exhibited affinity and kcat values similar to wild type. Furthermore, the 489-3A mutant showed a marked reduction in the positive electrostatic potential within this region of A2, consistent with the hypothesis that the cumulative basic charge in this region of A2 subunit modulates cofactor function.

Amino Acid Sequence↗
PubMed2003

Imaging a child's fundus without dilation using a handheld confocal scanning laser ophthalmoscope.

Images of the fundus were acquired in children without pupil dilation using a prototype handheld confocal scanning laser ophthalmoscope (SLO). A 780-nm laser beam imaged a 20 degrees x 20 degrees area of the fundus while a 645-nm beam scanned a fixation target. Scorable images of the optic nerve, macula, and vessels were obtained in 67 (72%) of 93 eyes from pediatric patients with nystagmus, amblyopia, media opacities, or optic nerve or macular abnormalities. Images were obtained in all eyes of pediatric and adult controls. Unsuccessful imaging was associated with media opacities, high refractive error, and poor cooperation. Disadvantages of the SLO were the inability to detect optic nerve pallor or consistently image the periphery. Advantages of the SLO were seen in children with nystagmus, photophobia, eccentric fixation, cone dystrophy, and mild papilledema.

Adolescent↗