Search PubMed⌕ Search

Biomedical subjects

Feng Zhou

Publications and source records attributed to Feng Zhou.

At least 37 records · Page 2Linked to original sources
PubMed2006

DNA interactions of a functionalized ruthenium(II) mixed-polypyridyl complex [Ru(bpy)2ppd]2+.

A novel polypyridyl ligand pteridino[7,6-f][1,10]phenanthroline-1,13(10H,12H)-dione (ppd) and its ruthenium(II) complex [Ru(bpy)2ppd]2+ have been synthesized and characterized by elemental analysis, electrospray mass spectra and 1H NMR. The interaction of the complex with calf thymus DNA was investigated by spectroscopic and viscosity measurements. The results suggest that the complex binds to DNA via an intercalative mode and serves as a molecular "light switch" for DNA. Moreover, the complex has been found to promote the photocleavage of plasmid DNA pBR322 under irradiation at 365 nm. The mechanism studies reveal that singlet oxygen (1O2) and superoxide anion radical (O2*(-))play a significant role in the photocleavage.

DNA↗
PubMed2006

Human herpesvirus-6-specific interleukin 10-producing CD4+ T cells suppress the CD4+ T-cell response in infected individuals.

Human herpesvirus-6 (HHV-6) infection normally persists for the lifetime of the host and may reactivate with immunosuppression. The mechanism behind HHV-6 latent infection is still not fully understood. In this study, we observed that decreased proliferation of CD4+ T cells and PBMCs but not CD8+ T cells from HHV-6-infected individuals was stimulated with HHV-6-infected cell lysates. Moreover, HHV-6-stimulated CD4+ T cells from HHV-6-infected individuals have suppressive activity on naïve CD4+ T and CD8+ T cells from HHV-6-uninfected individuals. However, no increased proportion of CD4+ CD25+ Treg cells from HHV-6-infected individuals contributed to the suppressive activity of the HHV-6-stimulated CD4+ T cells from HHV-6-infected individuals. Transwell experiments, ELISA and anti-IL-10 antibody blocking experiment demonstrated that IL-10 may be the suppressive cytokine required for suppressive activity of CD4+ T cells from HHV-6-infected individuals. Results of intracellular interleukin (IL)-10 and IL-4 further implicated the HHV-6-specific IL-10-producing CD4+ T cells in the suppressive activity of CD4+ T cells from HHV-6-infected individuals. Results of intracellular interferon (IFN)-gamma demonstrated a decreased frequency of HHV-6-specific IFN-gamma-producing CD4+ T, but not CD8+ T cells in HHV-6-infected individuals, indicating that it was the CD4+ Th1 responses in HHV-6-infected individuals that were selectively impaired. Our findings indicated that HHV-6-specific IL-10-producing CD4+ T cells from HHV-6-infected individuals possess T regulatory type 1 cell activity: immunosuppression, high levels of IL-10 production, with a few cells expressing IFN-gamma, but none expressing IL-4. These cells may play an important role in latent HHV-6 infection.

Adult↗
PubMed2006

HIV prevalence among injection drug users in rural Guangxi China.

AIMS: To determine the HIV-1 seroprevalence, risk behaviors and demographic characteristics associated with HIV-1 infection among injection drug users (IDU) in rural Guangxi, China. DESIGN AND SETTING: Between July and November 2002, 702 IDU were screened for HIV-1 antibody through community outreach in rural Guangxi, China for enrollment in an HIV sero-incidence study. PARTICIPANTS: A total of 702 active high-risk IDU were screened. High-risk injection was defined as anyone who reported injecting drugs at least three times per week in the last month or injected drugs with shared equipment on at least three occasions in the last 3 months. MEASUREMENTS: HIV-1 antibody testing with confirmation by Western blot was performed on all subjects. Demographic and risk assessment survey data were collected at screening from everyone whose baseline HIV antibody status was known. FINDINGS: HIV-1 antibody prevalence among 702 IDU at baseline was 25% with a median age of 26.7 years (18.2-43.2). Based on a multivariate logistic regression model using risk factors identified in univariate analyses, the following risk factors were associated significantly with an increase in risk for HIV seropositivity: age > 26 years (OR 1.50; 95% CI 1.04, 2.17), sharing of rinse water (OR = 1.24; 95% CI 1.09, 1.40), not having sex in the last 6 months (OR = 1.62; 95% CI 1.08, 2.43). CONCLUSIONS: HIV infection among IDU in Guangxi, one of China's major HIV epidemic regions, is high and the infection occurs predominantly among older IDU males who share rinse water.

Adolescent↗
PubMed2006

Sleep architecture in children with adenoidal hypertrophy.

AIM: Adenoidal hypertrophy (AH) in children is associated with obstructive manifestations like mouth breathing, snoring. Unfortunately, little is known regarding sleep architecture of AH in children. The purpose of this study was therefore undertaken to investigate the polysomnographic variables in children with AH. METHOD: 47 children with AH and 11 controls underwent nocturnal polysomnography. Sleep was scored manually according to the standard set by Rechtschaffen. RESULTS: In AH, stage 1 sleep percentage and rapid eye movement (REM) latency were increased significantly, while the sleep percentage of stage 2 and REM was decreased remarkably compared with that of controls. Arousal index in AH was much more higher than that in controls. Arousal index in REM sleep was higher than that in non-rapid eye movement (NREM) sleep in AH, but the number of arousals in REM sleep was lower than that in NREM sleep. Hypopnea events were the most common type of respiratory events, followed by obstructive events in AH and controls. Apnea/hypopnea index in AH was higher in comparison to controls. No significant difference was found between the children with AH and controls in SaO(2) nadir (%) and base mean SaO(2) (%). Apnea/hypopnea index was related to hypopnea arousal in REM sleep and hypoxemia arousal in NREM sleep. CONCLUSION: AH is predominantly characterised by a hypopnea with little obstruction in children. Our results clearly and for the first time demonstrated that sleep architecture was abnormal in children with AH. We therefore speculate that hypopnea arousal in REM sleep and hypoxemia arousal in NREM sleep may play an important role in the course of respiratory disturbance.

Adenoids↗
PubMed2006

Proteomic analysis of differential protein expression in early process of pancreatic regeneration in pancreatectomized rats.

AIM: A broad-range proteomic approach was applied to investigate the complexity of the mechanisms involved in pancreatic regeneration for identification of new targets of diabetes treatment and potential markers of pancreatic stem cells. METHODS: A regeneration pancreatic model was induced by 90% partial pancreatectomy (Px) in rats. Changes in the protein expression in regenerating rat pancreas on the third day after Px, as compared with rats that received sham surgery, were analyzed by using 2-D gel electrophoresis (2-DE), mass spectrometry (MS), and mass fingerprinting. RESULTS: 2-DE revealed 91 spots with at least 1.5-fold increases in expression at 3 d after pancreatectomy and 53 differentially expressed proteins that were identified by peptide mass fingerprinting (PMF). These included cell growth-related, lipid and energy metabolism-related, protein and amino acid metabolism-related proteins, and signal transduction proteins. Vimentin, CK8, L-plastin, hnRNP A2/B1, and AGAT are associated with embryogenesis and cell differentiation, and may be new potential pancreatic stem cells markers. CONCLUSION: The proteome profiling technique provided a broad-based and effective approach for the rapid assimilation and identification of adaptive protein changes during pancreas regeneration induced by pancreatectomy. Our data clarify the global proteome during the pancreatic proliferation and differentiation processes, which is important for better understanding of pancreatic regeneration and for discovering of protein biomarkers for pancreatic stem cells.

Amidinotransferases↗
PubMed2006

[Clinical value of multislice spiral CT in caudal block].

OBJECTIVE: To explore a new method for body surface orientation of the puncture site, determination of the direction of the needling and puncture depth for caudal block. METHODS: Three-dimensional reconstruction of the pelvis was performed in 8 cases for measuring the distances between the sacral hiatus and the planned site of anesthetic delivery and the size of the sacral hiatus. After image processing with the technique of shaded surface display (SSD), the shapes of sacral hiatus and sacral tube were evaluated. RESULTS: Three-dimensional reconstruction of the pelvis in the 8 cases allowed clear view from any directions of the sacral hiatus and sacral tube and accurate measurement of the size of the sacral hiatus. After simulated cutting of half of the rumpbone, the distances between the sacral hiatus and the drug injection site were accurately measured. With these measurements, accurate preoperative localization of the puncture site on the skin was achieved and the anesthesia was successful in all the cases. CONCLUSIONS: This technique can provide accurate data for localization of the puncture site on the skin and determination of the direction of the needling and the puncture depth for caudal block to increase the successful rate of anesthesia, lower the operative risks and allow simulated operative training.

Adolescent↗
PubMed2006

[Cytotoxic T lymphocyte antigen-4 promoter gene polymorphism is significantly associated with ulcerative colitis].

OBJECTIVE: Inflammatory bowel disease (IBD) is characterized by the T-cell excessive activation of intestinal mucosa. Cytotoxic T-lymphocyte associated antigen 4 (CTLA-4) is a negative regulator of T-lymphocyte activation. The aim of the present study is to investigate the association between CTLA-4 promoter -1722 (T/C), -1661 (A/G) polymorphisms and ulcerative colitis (UC) in Han Chinese, in Hubei province of central China. METHODS: Eighty-seven patients with UC and 116 healthy controls were genotyped for CTLA-4 promoter -1722 and -1661 polymorphisms with a method of polymerase chain reaction based restriction fragment length polymorphism. RESULTS: The frequency of "A/G + G/G" genotype at the -1661 site was statistically higher in UC patients than in healthy controls (34.5% vs 15.5%, P = 0.002, OR = 2.865, 95% CI = 1.467-5.596). The frequency of the G allele at the -1661 site was also significantly higher in UC patients than in the controls (19.0% vs 8.2%, P = 0.002, OR = 2.624, 95% CI = 1.435-4.796). However, the distribution of the genotypes at -1722 site was not significantly different between the UC patients and the controls. CONCLUSION: The G allele of CTLA-4 promoter -1661 polymorphism showed a highly significant association with UC in Han Chinese of the central China.

Adult↗
PubMed2006

[Optimal selection method of technologies of medical wastes treatment].

This paper investigate the medical wastes (MW) definition, production, characteristics and technical requirements, which is decisive for properly selecting methods for medical wastes treatment (MWT). Base on this, the advantages/disadvantages and adaptation of various treatment options are qualitatively analyzed and broadly compared. Then, four kinds of technologies, namely the thermal treatment, autoclaving, chemical disinfection, and microwave disinfection, are primarily chosen. Moreover, a hierarchy decision-making model considering the disposal status, economic level, policies and international turns is further set up. According to it, 4 proposed methods are effectively assessed. The result indicates that thermal treatment technology is the optimal choice for medical wastes treatment in Hangzhou city. Besides, the optimal selection method for medical wastes treatment is synthetically presented, which is suggested as a strong support for choosing optimal technology, and will contribute a lot to related research as well.

China↗
PubMed2006

An in vitro culturing model for rabbit dural cells.

The objectives of this study were (a) to construct an in vitro model of rabbit dural healing, (b) to test the influence of collagen, laminin, and poly-L-lysine on the migration and proliferation of dural cells, and (c) to study the healing mechanism of duraplasty. Rabbit dural pieces (1.5 cm x 1.5 cm) were perforated in their central part with a 2 mm punch to mimic a dural defect. The dural pieces were cultured in 24-well plates that had been coated with collagen, laminin, or poly-L-lysine, and the influence of different extracellular matrices on migration and proliferation of dural cells was observed. Cells were subcultured on slides for immunocytochemistry to study their characteristics; dural healing was observed by scanning electron microscopy. The results demonstrated that only the dural pieces that were cultured on collagen-coated wells showed migration of cells into the central defect after a period of 8 to 10 days and that healing of the dural defect occurred by 13 to 15 days. The cultured dural cells stained strongly positive with an antibody to vimentin, but negative with an antibody to factor VIII. New collagen fibers were observed in the dural defects. This report demonstrates that an in vitro model for dural healing was successfully constructed in collagen-coated wells; the results implicate cellular migration of fibroblasts from the dural defect margin as an important mechanism of wound healing following duraplasty.

Animals↗
PubMed2005

Matrine improves 2,4,6-trinitrobenzene sulfonic acid-induced colitis in mice.

Matrine is an alkaloid found in kinds of Sophora plants mainly including Sophora flavescens, Sophora alopecuroides and Sophora subprotrata. The aim of the present study was to evaluate therapeutic effects of matrine on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice. Two hours following colonic instillation of TNBS, matrine with several doses was given by gastric gavage once daily for 7 days. Comparing with the 0.9% NaCl-treated mice with TNBS-induced colitis, matrine (10 and 20 mg kg(-1))-treated mice with TNBS-induced colitis were shown improvements of weight loss, macroscopic score, histological score, and myeloperoxidase (MPO) activity. Moreover, treatments with matrine (10 and 20 mg kg(-1)) decreased the up-regulated mRNA and protein levels of tumour necrosis factor-alpha (TNF-alpha) caused by TNBS. Our findings suggest that matrine improves TNBS-induced colitis in mice and the therapeutic mechanism might be related to the reduction of up-regulated colonic TNF-alpha production caused by TNBS.

Alkaloids↗
PubMed2005

Stable biomimetic super-hydrophobic engineering materials.

We describe a simple and inexpensive method to produce super-hydrophobic surfaces on aluminum and its alloy by oxidation and chemical modification. Water or aqueous solutions (pH = 1-14) have contact angles of 168 +/- 2 and 161 +/- 2 degrees on the treated surfaces of Al and Al alloy, respectively. The super-hydrophobic surfaces are produced by the cooperation of binary structures at micro- and nanometer scales, thus reducing the energies of the surfaces. Such super-hydrophobic properties will greatly extend the applications of aluminum and its alloy as lubricating materials.

Aluminum↗
PubMed2005

HIV incidence and factors contributed to retention in a 12-month follow-up study of injection drug users in Sichuan Province, China.

HIV-1 seroconversion and subtype were evaluated, and factors associated with cohort retention were analyzed for subjects' baseline sociodemographic and behavioral characteristics in a 12-month follow-up study of injection drug users (IDUs). In November 2002, a community-based baseline survey was conducted to recruit 333 HIV-seronegative IDUs for a prospective cohort study in Xichang County of Sichuan Province, China. During the 12-month follow-up period, HIV incidence was 3.17 per 100 person-years (95% confidence interval [CI]: 0.98, 5.37), and all subtypes of 8 HIV-1 seroconversions were CRF_07BC. The retention rate at the 12-month follow-up visit was 70.3% (234 of 333 subjects). In a multiple logistic regression model, ethnicity (OR = 0.60, 95% CI: 0.34, 1.04) and appearing at the 6-month follow-up visit (OR = 9.03, 95% CI: 5.14, 15.89) were independently associated with retention. No drug-using or sexual behaviors were found to be associated with retention. This study confirmed one of drug-trafficking routes in mainland China, from Yunnan to Sichuan and then to Xinjiang. This study also suggested that HIV is spreading rapidly to more geographic areas along drug-trafficking routes in China, and a short-term follow-up rate may predict a long-term retention rate in this IDU cohort.

Adult↗
PubMed2005

Self-assembled structure in room-temperature ionic liquids.

Self-assembled vesicles, structurally equivalent to some hydrotropes, have been obtained from a Zn2+-fluorous surfactant or in the mixture of Zn2+-fluorous surfactant/zwitterionic surfactant in room-temperature ionic liquids (RTILs). The existence of bilayers arranged in vesicles in RTILs would be very exciting, open several new possibilities as reaction media, and increase our understanding of the physical and chemical factors for self-assembling systems in RTILs.

Journal Article↗
PubMed2005

Lack of chemokine receptor CCR5 promotes murine fulminant liver failure by preventing the apoptosis of activated CD1d-restricted NKT cells.

Fulminant liver failure (FLF) consists of a cascade of events beginning with a presumed uncontrolled systemic activation of the immune system. The etiology of FLF remains undefined. In this study, we demonstrate that CCR5 deficiency promotes the development of acute FLF in mice following Con A administration by preventing activated hepatic CD1d-restricted NKT cells (but not conventional T cells) from dying from activation-induced apoptosis. The resistance of CCR5-deficient NKT cells from activation-induced apoptosis following Con A administration is not due to a defective Fas-driven death pathway. Moreover, FLF in CCR5-deficient mice also correlated with hepatic CCR5-deficient NKT cells, producing more IL-4, but not IFN-gamma, relative to wild-type NKT cells. Furthermore, FLF in these mice was abolished by IL-4 mAb or NK1.1 mAb treatment. We propose that CCR5 deficiency may predispose individuals to the development of FLF by preventing hepatic NKT cell apoptosis and by regulating NKT cell function, establishing a novel role for CCR5 in the development of this catastrophic liver disease that is independent of leukocyte recruitment.

Animals↗
PubMed2005

[Vascular endothelial growth factor shRNA mediated by pEGFP-H1 vector plasmid effectively inhibits glioma proliferation: an experimental study].

OBJECTIVE: To investigate the inhibitory effects of RNA silencing via plasmid-mediated vascular endothelial growth factor (VEGF) shRNA on proliferation of glioma cells in vitro and in vivo. METHODS: pEGFP-H1/VEGF vector plasmid containing enhanced green fluorescent protein (EGFP) gene and expressing VEGF shRNA was constructed. The EGFP expression was detected by fluorescent microscopy and flow cytometry. Glioma cells of the line U251 were cultured and divided into 3 groups to be transfected with blank vector, pEGFP/H1plasmid, and pEGFP-H1/VEGF respectively. RT-PCR was used to detect the mRNA expression of VEGF in the supernatants of the culture media. The protein expression of VEGF in the supernatant was detected by ELISA. The cell growth was observed with MTT method. Fifteen nude rats were randomly divided into 3 equal groups to be transplanted with U251 cells and pEGFP-H1, U251 cells and pEGFP-H1/VEGF, and U251 cells only as blank control group. The growth of glioma was observed every day. 30 days after the rats were killed and the tumors were taken out to be examined. RESULTS: Twenty-four hours after transplantation, fluorescence microscopy showed great numbers of U251 cells that expressed green fluorescence in both the pEGFP-H1 group and pEGFP-H1/VEGF group. Flow cytometry showed that the rates of green fluorescent protein positive cells were 68.37% and 65.29% in these 2 groups (P > 0.05). MTT method showed no significant difference in the effect on cell growth among the 3 groups (all P > 0.05). PCR showed that the VEGF mRNA expression was significantly inhibited in the pEGFP-H1/VEGF group in comparison with those in the blank control group and the group transfected with pEGFP-H1 (both P < 0.05). The concentration of VEGF protein of the U251 cells transfected with pEGFP-H1/VEGF was 530 ng/L +/- 118 ng/L, significantly lower than those of the control group (2571 ng/L +/- 572 ng/L) and the group transfected with pEGFP-H1 (2402 ng/L +/- 310 ng/L, by 77.9%) (both P < 0.01). Tumor could be touched 13 days after transplantation in the rats of pEGFP-H1/VEGF group, markedly later than in the other 2 groups. Thirty days after, the weight and volume of tumor were 0.5 g +/- 0.4 g and 401 mm(3) +/- 272 mm(3) respectively in the rats of pEGFP-H1/VEGF group, both significantly lower than those of the control group and pEGFP-H1 group (1.7 g +/- 0.4 g and 1573 mm(3) +/- 330 mm(3); and 1.5 g +/- 0.7 g and 1430 mm(3) +/- 382 mm(3)) (all P < 0.01). CONCLUSION: The successfully constructed shRNA targeting at VEGF efficiently decreases the VEGF expression of the glioma cells in vitro and suppresses the growth of glioma cells in vivo.

Animals↗
PubMed2005

Protein profiling by capillary isoelectric focusing, reversed-phase liquid chromatography, and mass spectrometry.

An automated system for intact protein analysis is described that combines capillary isoelectric focusing (CIEF), reversed-phase liquid chromatography (RPLC), and electrospray ionization-mass spectrometry (ESI-MS). Performance is demonstrated with a complex yeast enzyme concentrate. CIEF is performed with a microdialysis membrane-based cathodic cell that permits pI fractions to be sampled and stored for subsequent LC-MS analysis. A total of 50 microg protein is loaded onto the capillary. Ten fractions are stored which span the pI range 3-10. Each fraction is subsequently cleaned on a reversed-phase trap column and then characterized by LC-MS. MaxEnt1 is used to deconvolute the raw mass spectra to obtain the molecular weight (MW) of intact proteins/peptides in the sample. A two-dimensional display of pI vs. MW is illustrated for the 500 most prevalent species as identified by MaxEnt1.

Chromatography, Liquid↗
PubMed2005

CD154-CD40 interactions drive hepatocyte apoptosis in murine fulminant hepatitis.

The CD154-CD40 interaction is a critical costimulatory pathway modulating the cellular immune response. Moreover, fulminant hepatitis of various etiologies is characterized by a hepatic influx of CD154-expressing T cells and an upregulation of CD40 expression on Kupffer cells and hepatocytes, implicating this pathway in the pathogenesis of fulminant hepatitis. In this study, we used a murine model of fulminant hepatitis induced by concanavalin A (con A) and documented a significant influx of CD154-expressing T cells into the livers of mice treated with con A, in association with markedly increased expression of CD40 restricted mainly to hepatocytes in damaged areas of the liver. Furthermore, con A hepatitis in CD154-deficient mice was significantly attenuated compared with that in wild-type controls and was associated with a decrease in hepatic tumor necrosis factor alpha (TNF-alpha) levels and hepatocyte death. We next determined the role of the CD154-CD40 pathway in hepatocyte death in vitro. These in vitro studies demonstrated that TNF-alpha induces CD40 expression in hepatocytes and that subsequent activation of CD40 results in hepatocyte apoptosis mediated at least in part by enhanced hepatocyte expression of FasL. In conclusion, CD154 stimulation of CD40 plays a central role in hepatocyte death in fulminant hepatitis through direct and indirect pathways that may have direct therapeutic implications in humans. Supplementary material for this article can be found on the HEPATOLOGY website (http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html).

Animals↗