Lifesaving decompressive craniectomy in 'malignant' cerebral venous infarction.
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Cerebral Infarction↗
Biomedical subjects
L Zeng
Publications and source records attributed to L Zeng.
Multitude of core-localized shear Alfvén waves in a high-temperature fusion plasma.
Evidence is presented for a multitude of discrete frequency Alfvén waves in the core of magnetically confined high-temperature fusion plasmas. Multiple diagnostic instruments confirm wave excitation over a wide spatial range from the device size at the longest wavelengths down to the thermal ion Larmor radius. At the shortest scales, the poloidal wavelengths are comparable to the scale length of electrostatic drift wave turbulence. Theoretical analysis confirms a dominant interaction of the modes with particles in the thermal ion distribution traveling well below the Alfvén velocity.
Journal Article↗
Significance of C4d deposition in the diagnosis of rejection after liver transplantation.
C4d immunohistochemical staining of liver allograft biopsies was performed to assess its relationship to other pathological changes in the liver. C4d deposition was detected in 69.2% of liver graft biopsies from patients under going rejection, 33.3% of liver graft biopsies from patients with hepatitis B relapse after transplantation, and 28.6% of liver biopsies from patients with hepatitis B. When rejection occurred C4d deposition was located in the vascular walls of portal areas and hepatic sinusoidal walls. Examination of biopsies from patients with hepatitis B relapse after transplantation or hepatitis B infection showed C4d deposition only in the vascular walls of the portal area. C4d deposition in both vascular walls of portal area and hepatic sinusoidal walls was detected in only one of 12 ischemia-reperfusion damage cases. Repeated biopsy of the same patient 1 month later revealed acute cellular rejection. No C4d deposition was found in biopsies from a patient with bile duct occlusion after liver transplantation. C4d might serve as a sensitive marker for the diagnosis of liver rejection.
Acute Disease↗
Selective depletion of activated T cells by recombinant immunotoxin containing anti-CTLA-4 single-chain fragment of variable antibody and N-terminal fragment of perforin.
We constructed a novel immunotoxin, hS83P34, by fusing the fragment containing the N-terminal 34 amino acids of human perforin to the C-terminal of humanized anti-CTLA-4 single chain fragment of variable antibody. In vitro cytotoxicity assays demonstrated that CTLA-4-positive activated human T cells and 6T-CEM were sensitive to hS83P34, while CTLA-4-negative resting T cells and endothelial cell ECV-304 were resistant to hS83P34. The IC50s of hS83P34 for activated T cells and 6T-CEM were about 0.2 micromol/L and 1.0 micromol/L, there was no obvious cytotoxicity of ECV-304 as detected at 8 micromol/L of hS83P34. In tumor graft rejection models, after treatment with 1.2 mg/kg immunotoxin every day for 12 days, the transplanted tumor cells were rescued by immunotoxin. The tumor weights of grafts of the rejection control group, nonrejection control group, and test group were 0.006 +/- 0.014 g, 0.261 +/- 0.048 g, and 0.135 +/- 0.056 g, respectively. In the early 3 days posttransplantation, there were a lot of CD4- and CD8-positive T cells infiltrating into the tumor grafts of the rejection control group, while only a few T cells were detected in the tumor grafts of the test group. According to these results, we concluded that immunotoxin hS83P34 selectively depleted activated T cells in vitro as well as in vivo in an acute rejection model.
Antigens, CD↗
Stem cells, vascular smooth muscle cells and atherosclerosis.
Stem cells have the ability to differentiate into a variety of cells to replace dead cells or to repair tissue. Recently, accumulating evidence indicates that mechanical forces, cytokines and other factors can influence stem cell differentiation into vascular smooth muscle cells (SMCs). In developmental process, SMCs originate from several sources, which show a great heterogenicity in different vessel walls. In adult vessels, SMCs display a less proliferative nature, but are altered in response to risk factors for atherosclerosis. Traditional view on SMC origins in atherosclerotic lesions is challenged by the recent findings that stem cells and smooth muscle progenitors contribute to the development of atherosclerotic lesions. Vascular progenitor cells circulating in human blood and the presence of adventitia in animals are recent discoveries, but the source of these cells is still unknown. The present review gives an update on the progress of stem cell and SMC research in atherosclerosis, and discusses possible mechanisms of stem/progenitor cell differentiation that contribute to the disease process.
Animals↗
Ammonia recovery from anaerobically digested cattle manure by steam stripping.
Ammonia recovery from anaerobically digested cattle manure effluents through steam stripping was studied at a stripping tower temperature of 98-99 degrees C and a steam-water ratio approximately 56-72 g/L. The digested manure effluents were first treated by microfiltration and then the permeate was used as feed in steam stripping. The stripping performance was evaluated under different feed pH values, ammonia concentrations and temperatures. The increase of the initial feed pH does not significantly improve ammonia stripping efficiency due to the fact that the stripped effluent pH is increased during steam stripping. This suggests that steam stripping of anaerobically digested manure effluents for ammonia recovery may not need pre-raised pH. In contrast, the pH value of the synthetic ammonia wastewater containing NH4Cl dramatically decreases after steam stripping. Increasing the feed temperature slightly improves ammonia stripping efficiency, but reduces the concentration of the recovered ammonia in the condensate due to an increased condensate volume at a higher feed temperature. Therefore, the feed temperature should be controlled at an optimum point that can compromise the condensate ammonia concentration and the ammonia stripping efficiency. Experimental results indicate that recovery of ammonia from anaerobically digested cattle manure effluents as NH4OH is technically feasible.
Ammonia↗
Vascular endothelial growth factor gene therapy with intramuscular injections of plasmid DNA enhances the survival of random pattern flaps in a rat model.
The objective of this study was to determine the effects of the naked plasmid DNA encoding vascular endothelial growth factor (VEGF) on the survival of random flaps on rats. Thirty Sprague-Dawley rats whose random flaps were elevated on the back were randomised into three groups of 10 animals each. In the experimental group, the naked plasmid DNA encoding VEGF was injected directly into the panniculus carnosus of the flap. In the two control groups, either control plasmid DNA or physiologic saline was injected. After 7 days, the flaps were evaluated with the following devices: RT-PCR for the expression of VEGF gene, immunohistochemistry for the expression of VEGF protein, histology for vascular density, single photon emission computerised tomography for RBC in the flap, and image analysis for flap survival area. Notably increased expressions of VEGF mRNA and VEGF protein were found in the treatment group. Vascular density was markedly more increased in the treatment group than those in the two control groups (P < 0.01). Compared with the two control groups, the flap treated with VEGF plasmid DNA showed a more significantly enhanced tissue viability: 87 +/- 5 versus 47 +/- 6% for the control plasmid DNA group and 46 +/- 5% for the saline group (P < 0.01). Our results indicated that the VEGF gene therapy was able to enhance the survival of random pattern flaps by inducing angiogenesis.
Animals↗
Latent membrane protein 1 encoded by Epstein-Barr virus modulates directly and synchronously cyclin D1 and p16 by newly forming a c-Jun/Jun B heterodimer in nasopharyngeal carcinoma cell line.
Recently we confirmed that latent membrane protein 1 (LMP1) encoded by Epstein-Barr virus (EBV) accelerates a newly forming active c-Jun/Jun B heterodimer, a transcription factor, but little is known about the target gene regulated by it. In this paper, results indicated that a c-Jun/Jun B heterodimer induced by LMP1 upregulated cyclin D1 promoters activity and expression, on the contrary, downregulated p16, and maladjustment of cyclin D1 and p16 expression accelerated progression of cell cycle. Firstly, we found a c-Jun/Jun B heterodimer regulated synchronously and directly cyclin D1 and p16 in the Tet-on-LMP1-HNE2 cell line, in which LMP1 expression is regulated by Tet-on system. This paper investigated in depth function of the newly forming active c-Jun/Jun B heterodimer, and built new connection between environmental pathogenic factor, signal transduction and cell cycle.
Carcinoma↗
Canine haematopoietic chimerism analyses by semiquantitative fluorescence detection of variable number of tandem repeat polymorphism.
Canine models are successfully applied to the study of haematopoietic stem cell transplantation (HSCT). Monitoring of haematopoietic donor/recipient chimerism is of major significance in detecting and quantifying engraftment or graft rejection of the donor-derived haematopoietic cells after transplantation. Radioactive analyses of polymorphic microsatellite markers are commonly used for chimerism analyses. We describe an improved, non-isotopic method that is based on the analysis of microsatellite markers in donor and recipient cells using capillary electrophoresis and fluorescence detection. Artificial mixtures of donor and recipient DNA that were generated from peripheral blood mononuclear cells from dog leukocyte antigen-identical siblings were used to analyse the sensitivity of the assay. DNA from dogs that had received HSCT were also analysed in order to demonstrate the feasibility of the method in vivo. For chimerism analyses, six different microsatellite loci were systematically amplified using fluorescent PCR primer. The fluorescent polymerase chain reaction products were separated by capillary electrophoresis using POP4 on a 310 ABI Prism Genetic Analyzer. After electrophoresis, fluorescence signals were automatically sized and quantified using GeneScan software. The method described provides an accurate assessment of haematopoietic chimerism in the canine model with significantly reduced hands-on time compared to conventional gel electrophoresis.
Animals↗
Feeding practice among younger Tibetan children living at high altitudes.
OBJECTIVE: Few published data are available on the feeding practice of younger children in Tibet. Our study investigated feeding pattern of younger Tibetan children. DESIGN AND SUBJECTS: The study was a cross-sectional survey conducted in Tibet. A sample of 1655 children younger than 36 months old and their mothers was obtained by stratified multistage cluster random sampling method. Mothers were interviewed to collect information on feeding practice by a designed family questionnaire including initial time and duration of breastfeeding and time, frequency and types of complementary foods introduced. RESULTS: Most of the children was ever or being breastfed at the time of interview. The median duration of breastfeeding was 26 months. The prevalence of almost exclusive breastfeeding for 4 months was 20.1%. Mothers' age and education, child's residence, and introduction of egg, fresh milk and milk powder were strongly associated with the duration of breastfeeding. The partial feeding was a main pattern in the first 6 months of life. Zanban and porridge were offered at about 1 month after birth. By 6th month, less than 25% of children were fed protein foods such as egg and meats and only near 20% of children were fed fresh vegetables. Bean products, fish and chicken were seldom offered to children. CONCLUSIONS: We conclude that although they were breastfed for long time, complementary feeding practice of Tibetan children was disadvantaged, especially of rural children. Improvement of monotonous complementary foods and timely introduction should be stressed in local programmatic nutritional interventions.
Altitude↗
Apoptotic regulators in prostatic intraepithelial neoplasia (PIN): value in prostate cancer detection and prevention.
Early diagnosis of prostate cancer holds tremendous promise for the effective therapy and impact on survival of prostate cancer patients. High-grade prostatic intraepithelial neoplasia (HGPIN) is generally accepted as a lesion indicative of a late pathological event in the premalignant changes leading to full development of prostate cancer. This review seeks to identify specific molecular events that may be linked directly to the molecular transition from benign prostate epithelial cells to prostate carcinoma. HGPIN is pathologically detected in a limited group of men undergoing prostate cancer screening for an elevated serum prostate-specific antigen (PSA) or abnormal digital rectal examination (DRE). Loss of apoptotic control provides a molecular basis for the contribution of specific defective steps in the pathway towards development and progression of prostate cancer. Comparative dissection of the apoptosis status and expression profile of key apoptotic regulators among foci of highly proliferative benign prostatic epithelium, PIN and prostate adenocarcinoma from adjacent areas of the same gland revealed a novel insight into the dysfunctional apoptosis events contributing to prostate carcinogenesis. The sequential and notable loss of the three critical signaling components of the apoptotic action of transforming growth factor-beta (TGF-beta), in the prostate, that is, the transmembrane receptor II (TbetaRII), the key cell cycle inhibitor p27(Kip1), as well as the protagonist downstream effector of the TGF-beta signaling mechanism, Smad4, points to their potential value to 'faithfully' characterize HGPIN, as a premalignant prostate lesion. Recent evidence on the molecular changes in apoptosis regulators contributing to HGPIN and their role as molecular markers of disease onset, as well as candidates for therapeutic targeting/chemoprevention of prostate cancer in its early stages will be discussed.
Adenocarcinoma↗
Suppression of large edge-localized modes in high-confinement DIII-D plasmas with a stochastic magnetic boundary.
A stochastic magnetic boundary, produced by an applied edge resonant magnetic perturbation, is used to suppress most large edge-localized modes (ELMs) in high confinement (H-mode) plasmas. The resulting H mode displays rapid, small oscillations with a bursty character modulated by a coherent 130 Hz envelope. The H mode transport barrier and core confinement are unaffected by the stochastic boundary, despite a threefold drop in the toroidal rotation. These results demonstrate that stochastic boundaries are compatible with H modes and may be attractive for ELM control in next-step fusion tokamaks.
Journal Article↗
The novel molecule porcine OSR1 up-regulated expression on porcine endothelial cell by human peripheral blood mononuclear cell activation.
INTRODUCTION: Clinical xenotransplantation is being considered to overcome the shortage of human organ donors. In our previous studies, using human-anti-porcine xenogeneic mixed mononuclear cell-endothelial cell cultures with the suppression subtractive hybridization method, we obtained a subtracted cDNA library that included about 300 clones corresponding to up-regulated genes. One porcine sequence showed 81% identity with the human oxidative-stress responsive 1 (OSR1) molecule. The objective of this study was to confirm the gene up-regulation and obtain the full-length sequences. METHODS: The full-length gene was cloned through the technique of rapid amplification of cDNA ends (RACE). The other methods included bioinformatics analysis and RT-PCR. RESULTS: RT-PCR confirmed that the gene was up-regulated upon the interactions of human peripheral blood mononuclear cells (PBMCs) and porcine endothelial cells. By SMART RACE technique, we obtained the full-length cDNA of porcine OSR1. The gene is 4333 bp. The open-read frame of 1590 bp encodes 529 amino acid residues. GenBank accession number is AY271356. The gene shows 92.8% nucleotide identity and 95.5% amino acid identity with human OSR1. CONCLUSION: We obtained the full-length cDNA of porcine OSR1. It was up-regulated on porcine endothelial cells following activation by human PBMCs. We succeeded in constructing a pcDNA-pOSR1 recombinant eukaryotic cell expression vector, the function of which is the subject as our ongoing work.
Amino Acid Sequence↗
Poor nutritional status of younger Tibetan children living at high altitudes.
BACKGROUND: The growth, development and nutrition of children in Tibet with high-altitude and unique traditional culture have recently gained attention. However, few researches are available on the nutritional status of younger children of Tibet. OBJECTIVE: The objective of the study was to evaluate the nutritional status of children below 36 months old in Tibet by means of anthropometry. DESIGN: The cross-sectional survey was conducted between August and September in 1999 and a sample of 1655 children below 36 months old was obtained using a stratified multistage cluster random sampling method from a total of seven districts of Tibet. Height, weight and hemoglobin concentration were measured and at the same time related sociodemographic and environmental information were collected. NCHS/CDC/WHO reference data were used to evaluate the nutritional status of the entire study children population and estimate the prevalence of stunting, underweight and wasting. RESULTS: Compared with the reference of NCHS/CDC/WHO, the distributions of HAZ and WAZ shifted to the left significantly and the means of HAZ and WAZ were -1.53 and -1.05, respectively, which were significantly lower than the reference value. The distribution of WHZ, however, was close to that of the reference. The reduction of Z-scores for height and weight occurred very early in life and was greatest in the second year after birth. The prevalence of malnutrition of children was 39.0% for stunting, 23.7% for underweight and 5.6% for wasting, respectively. Rural children had prevalence of stunting of 41.4% and underweight of 24.7%, as compared with prevalence of stunting of 25.3% and underweight of 18.1% for urban children. Stunting and underweight were associated with altitudes. The mean of hemoglobin (Hb) of children was 120.4 g/l and rural children had a significantly lower Hb concentration (119.9 g/l) than urban children (123.3 g/l). The prevalence of anemia seemed higher when using different altitude corrections for Hb to estimate the prevalence, but the consequences were uneven. CONCLUSIONS: For Tibetan young children, the nutritional status of the entire population is poor and the prevalence of malnutrition is higher, especially for stunting. Malnutrition is related to high altitudes. Although the Hb concentration is higher induced by high altitude, there must be quite a lot of anemic children at high altitudes. The relationship between altitude and Hb for children on the Tibetan plateau requires further study in order to determine correctly the magnitude of anemia of children.
Altitude↗
Isolation and characterization of rice mutants compromised in Xa21-mediated resistance to X. oryzae pv. oryzae.
The rice gene, Xa21, confers resistance to diverse races of Xanthomonas oryzae pv. oryzae (Xoo) and encodes a receptor-like kinase with leucine-rich repeats in the extra-cellular domain. To identify genes essential for the function of the Xa21 gene, 4,500 IRBB21 ( Xa21 isogenic line in IR24 background) mutants, induced by diepoxybutane and fast neutrons, were screened against Philippine race six (PR6) Xoo for a change from resistance to susceptibility. From two greenhouse screens, 23 mutants were identified that had changed from resistant to fully (6) or partially (17) susceptible to PR6. All fully susceptible mutants carried rearrangements at the Xa21 locus as detected by PCR and Southern hybridization. For the partially susceptible mutants, no changes were detected at the Xa21 locus based on Southern and PCR analyses. However, two of these mutants were confirmed via genetic analysis to have mutations at the Xa21 locus. Partially susceptible mutants exhibited variation in level of susceptibility to different Xoo strains, suggesting that they may carry different mutations required for the Xa21-mediated resistance. The mutants identified in this study provide useful materials for dissecting the Xa21-mediated resistance pathway in rice.
Blotting, Southern↗
A quantitative assay of alpha-GAL expressed on pig blood cells.
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Animals↗
Efficient gene transfer into human monocyte-derived macrophages using defective lentiviral vectors.
Gene therapy is a promising approach for the treatment of neurological disorders. However, current approaches to gene transfer in the central nervous system (CNS) are limited by the lack of effective, but non-invasive methods to deliver transgenes across the blood-brain barrier (BBB). In an effort to begin to explore the use of migratory monocytes as vehicles for delivery of therapeutic and antiviral genes into the CNS, we have utilized three HIV-based transfer vectors encoding cis-acting elements but lacking either structural genes (gag/pol and env), most accessory genes (vif, vpr and nef) and/or rev. These defective lentiviral vectors (DLV) encode the green fluorescent protein (GFP), display potent antiviral activity in CD4+ lymphocytes and can be mobilized by wild-type HIV-1 DLV were generated by transient transfection of 293T cells. Vector titers ranged from 4.2-6.6 x 10(6) infectious units (IU)/ml prior to concentration (by ultracentrifugation) and were equal to or higher than 1 x 10(9) IU/ml after concentration. Primary human monocyte-derived macrophages (MDM) were exposed to DLV resulting in efficiencies of transduction ranging from 14 to 26%. GFP expression in transduced MDM remained stable for more than 8 weeks without apparent cytopathic effect. Given the previously reported antiviral activities of these DLV and their lack of cytopathic effects on primary MDM, it may be possible to use these vectors to inhibit HIV-1 replication within the CNS.
Cells, Cultured↗
Fine genetic mapping and physical delimitation of the lesion mimic gene Spl11 to a 160-kb DNA segment of the rice genome.
The rice lesion mimic mutant spl11 was previously found to confer broad-spectrum disease resistance to both Magnaporthe grisea and Xanthomonas oryzae pv. oryzae. To better understand the molecular basis underlying cell death and disease resistance in rice, a map-based cloning strategy has been employed to isolate Spl11. Five Spl11-linked RAPD markers were developed and four of them were mapped to rice chromosome 12. A high-resolution genetic map was developed using a segregating population consisting of 1138 lesion mimic individuals. Recombination suppression was observed in the vicinity of Spl11. Three molecular markers tightly linked to Spl11 were identified and used to screen a BAC library. A contig spanning the Spl11 locus was constructed and physical mapping delimited Spl11 to a 160-kb DNA segment within a single BAC clone. These results provide the essential information for the final isolation of this important gene in the rice defense pathway.
Apoptosis↗