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Wei Gao

Publications and source records attributed to Wei Gao.

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

Isolation of neural stem cells from the spinal cords of low temperature preserved abortuses.

In the present study, we show that neural stem cells can be obtained from the spinal cords of low temperature preserved abortuses. Fourteen weeks old abortuses were stored in a refrigerator at 4 degrees C for 2 h, 6 h and 12 h before use. Neural stem cells were isolated from cervical cord, thoracic cord and lumbar/sacral cord separately and induced to differentiate with fetal bovine serum. Clonal culture was carried out to demonstrate that the isolated cells met the standard of stem cells. Fluorescent immunocytochemistry was used to examine the expression of neural stem cell marker (nestin), neuronal marker (MAP2), astrocyte marker (GFAP) and cholinergic marker (ChAT). The stem cells in different cultures were compared. As a result, neural stem cells were obtained from all the spinal cord segments with different postmortem intervals. The lumbar/sacral cord cultures gave rise to the most abundant primary neurospheres. When the preservation was prolonged to 12 h, the number of primary neurospheres decreased sharply. Neurospheres in all cultures showed nestin positive immunoreactivity and could yield astrocytes and neurons including cholinergic neurons in differential cultures. The clonal formation and phenotype capacity were similar in all cultures. In conclusion, spinal neural stem cells can be isolated from low temperature preserved abortuses and represent an alternative source for both experimentation and potential therapeutic uses.

Aborted Fetus↗
PubMed2006

[Effect of hyperhomocysteinemia on cardiac remodeling in rats].

OBJECTIVE: To study the effects of hyperhomocysteinemia on cardiac remodeling and systolic function. METHODS: Twenty-four Wistar rats were divided randomly into experiment and control group. 12 rats of experiment group were bred with 1 g/(kg.d) L-methionine. After 4 weeks, 6 of them were killed (HHcy), others were continuously bred with normal diet for 4 weeks (Quit hcy, QHcy). Twelve rats of control group with normal diet for 4 and 8 weeks. The plasma Hcy concentrations were measured by immuno-fluorescence technique. Left ventricular structure and systolic function were assessed by echocardiography. The cardiac morphology and collagen were studied by optical microscopy and image analysis system after hematoxylin eosin-staining and picrosirius red-staining. Immuno-histochemistry for actin-smooth muscle and factor VIII-related antigen was performed to identify changes in cardiac smaller arteriolar and microvascular numbers. RESULTS: The plasma Hcy concentration was (106.19+/-19.75) micromol/L in HHcy, (6.52+/-0.94) micromol/L in QHcy and (4.90+/-0.10) micromol/L in the control. Left ventricular systolic function was decreased 10.7% in HHcy. Left ventricular wall strain and cardiac smaller arteriolar wall thickness were increased by 62.1% and 2.9 fold in HHcy, 27.1% and 2.4 fold in QHcy as compared with the control. Cardiomyocyte diameter was not changed in HHcy and increased by 15.4% in QHcy as compared with the control. Microvascular number was decreased by 45.9% in HHcy as compared with the control, but smaller arteriolar number did not differ among the groups. Left ventricular systolic function and microvascular number resumed in QHcy. Interstitial and perivascular collagen deposition was significantly increased in HHcy and QHcy. CONCLUSION: Hyperhomocysteinemia may increase cardiomyocyte diameter, cardiac smaller arteriolar wall thickness and left ventricular wall strain; decrease microvascular number; induce interstitial and perivascular collagen deposition, directly and indirectly affect on cardiac remodeling and systolic function. The cardiac remodeling couldn't resume completely with plasma Hcy concentration being decreased.

Animals↗
PubMed2006

Hyperhomocysteinemia and low plasma folate as risk factors for central retinal vein occlusion: a case-control study in a Chinese population.

PURPOSE: To determine whether hyperhomocysteinemia and low plasma folate are risk factors for central retinal vein occlusion (CRVO) in the Chinese population. METHODS: A matched case-control study was conducted between July 2004 and May 2005. The study cohort consisted of 64 individuals that had been diagnosed to have CRVO and 64 normal controls (matched for age, gender, hypertension, smoking and drinking habits). None of the cases or controls had a history of diabetes, glaucoma, medication or any other vascular events that might minimize the influence on plasma homocysteine levels. A cross-sectional analysis among the 64 cases was performed to compare the prevalence of hyperhomocysteinemia and low plasma folate among subjects with and without ischemia and subjects with age above 45 and below 45 years. Plasma homocysteine level was measured by means of high-performance liquid chromatography and plasma folate concentration by radioimmunoassay. RESULTS: The CRVO patients had a significantly higher homocysteine level (13.83+/-1.71 micromol/l) than the normal controls (8.05+/-0.58 micromol/l; p=0.003). The plasma folate levels were significantly lower in CRVO patients than in controls (5.62+/-0.39 ng/dl vs 7.23+/-0.60 ng/dl; p=0.032). A 1 micromol/l increase of plasma homocysteine level was associated with an odds ratio of 1.368. Hyperhomocysteinemia was defined as a homocysteine level of >14.97 micromol/l and was seen in 11 patients in the ischemic group, significantly more often than in the non-ischemic group (5 patients; p=0.030). CONCLUSIONS: The results suggest that hyperhomocysteinemia and low plasma folate are independent risk factors for CRVO and are associated with the development of CRVO in the Chinese population.

Adult↗
PubMed2006

[Effects of tissue inhibitor of matrix metalloproteinases-4 on the activities of matrix metalloproteinases and collagen of artery: experiment with rats].

OBJECTIVE: To investigate the effects of tissue inhibitor of matrix metalloproteinases-4 (TIMP-4) on the activities of matrix metalloproteinases (MMPs) and the collagen deposition. METHODS: Vascular smooth muscle cells (VSMCs) of rat thoracic aorta were cultured and divided into 3 groups: 2 groups to be transfected with adenovirus vector containing green fluorescence protein (AdGFP) or adenovirus vector containing TIMP-4 (AdTIMP-4), and one group un-transfected. Zymography and reverse zymography were used to detect the activities of MMP-2, MMP-9 and TIMP-4 in the supernatants. Male Wistar rats underwent balloon injury of common carotid artery and then divided into 3 groups: pure injury group, AdGFP transfection group, and AdTIMP-4. transfection group. Four and 28 days later 3 and 6 rats were killed in each group respectively to undergo microscopy and examination of the activities of MMP-2, MMP-9, and TIMP-4, and collagen quantity. RESULTS: The MMP-2 activity in the VSMC culture fluid supernatant of the AdTIMP-4 group was decreased dose-dependently, however, the activity of MMP-9 did not changed significantly among the 3 groups. Bands of activated MMP-2 and MMP-9 could not be examined in the normal vessel tissues. Four hours after the injury, the activity of MMP-2 was significantly increased in the pure injury group and AdGFP group, however, was significantly decreased in the AdTIMP-4 group. Four days later no MMP activity could be detected in either group. The neoformation of tunica intima was inhibited by 66% in the AdTIMP-4 group, The collagen quantity per vessel cell was 12.1 +/- 1.0 in the AdGFP group, not significantly different from that of in the AdTIMP-4 group (11.9 +/- 1, P > 0.05), and the collagen quantity per tunica adventitia cell in the AdTIMP-4 group was 118 +/- 13, not significantly different from that of the pure injury group (135 +/- 11, P > 0.05). CONCLUSION: The regulation of MMP/TIMP balance by TIMP-4 may control the metabolism of collagen and play an important role in the vascular repair process.

Adenoviridae↗
PubMed2006

Modulation of antigen-specific T cell response by a non-mitogenic anti-CD3 antibody.

Suppression of T cell response is the key to enhance graft survival and control autoimmune diseases. A mitogenic anti-CD3 monoclonal antibody (mAb), OKT3, has been used for decades to control acute rejection in organ transplantation. Although effective, the clinical use was limited by its side effects, such as cytokine release mediated by T cell activation. A low mitogenic humanized OKT3 with reduced FcR-binding (hgammaOKT3 Ala-Ala) was generated and tested in several clinical studies. Although hgammaOKT3 Ala-Ala demonstrated maintained efficacy and better safety it still activated T cells. To investigate if a non-mitogenic anti-CD3 mAb can be equally effective in immune suppression, a chimeric non-FcR-binding anti-mouse CD3 mAb (anti-CD3 IgG2a Ala-Ala) was generated. Unlike the hgammaOKT3 Ala-Ala, the mouse IgG2a Ala-Ala anti-CD3 mAb did not induce T cell activation as measured by proliferation, cytokine production and apoptosis. Nevertheless, the IgG2a Ala-Ala anti-CD3 mAb was equally effective in the inhibition of antigen-specific CD4+ T cell activation in vitro to that of the mitogenic anti-CD3 mAb (Anti-CD3 IgG2a). In vivo, the IgG2a Ala-Ala anti-CD3 mAb only induced transient reduction of peripheral and spleen T cells and did not trigger detectable cytokine release. Nonetheless, this non-mitogenic anti-CD3 mAb significantly prolonged islet graft survival as effectively as the mitogenic anti-CD3 mAb in an allogenic islet transplantation model. These results demonstrated that a non-mitogenic anti-CD3 mAb could be used as an effective immune modulator. It may also indicate that a true non-mitogenic version of OKT3 could further improve its safety profile for clinical use.

Animals↗
PubMed2006

An antagonist mutant IL-15/Fc promotes transplant tolerance.

BACKGROUND: IL-15 is a proinflammatory and antiapoptotic T-cell growth factor that plays an important role in a variety of autoimmune disorders and transplant rejection. To inhibit IL-15 function and to target IL-15 receptor (IL-15R) bearing cells, we have generated a unique lytic antagonistic mutant IL-15/Fc fusion protein (mIL-15/Fc). METHODS: In this study, we further examined the efficacy of mIL-15/Fc in preventing allograft rejection cross minor and major histocompatibility barriers. RESULTS: A short-course treatment with mIL-15/Fc fusion protein is sufficient to prevent cardiac allograft rejection and induce antigen-specific tolerance in minor histocompatibility complex-mismatched recipients, and permit prolonged cardiac allograft survival in fully MHC mismatched recipients. In addition, mIL-15/Fc treatment, in combination with a suboptimal dose of anti-CD154 antibody, confers permanent cardiac allograft engraftment in a fully MHC-mismatched mouse strain combination. In a murine islet allograft model, mIL-15/Fc monotherapy is capable to permit permanent allograft survival in 50% fully MHC-mismatched recipients. CONCLUSION: Immunochemistry studies demonstrated that prolonged graft survival was accompanied by reduced intragraft mononuclear cell infiltration and pro-inflammatory cytokine gene expression in the mIL-15/Fc treated recipients. Moreover, parallel experiments employing a mutated nonlytic IgG2a Fc demonstrate that the Fc portion of mIL-15/Fc contributes to the overall efficacy of the molecule in vivo.

Animals↗
PubMed2006

Analysis of genetic diversity in Ganoderma population with a novel molecular marker SRAP.

Genetic marker technology designed to detect naturally occurring polymorphisms at the DNA level had become an invaluable and revolutionizing tool for both applied and basic studies of fungi. To eliminate the confusion on the taxonomy of Ganoderma strains, in this study, a collection of 31 accessions representative of morphotypes and some unclassified types was used for analyzing molecular diversity using a novel molecular marker sequence-related amplified polymorphism (SRAP). This collection included commercial cultivars and wild varieties that represented the great diversification of types from different countries and regions. The experimental results showed that 50 out of 95 combinations of primers turned out to be polymorphic, and 85 polymorphism bands were obtained using six combinations. Based on the appearances of markers, the genetic similarity coefficients were calculated, and genetic variations were observed (0 approximately 1) among the 31 different Ganoderma strains. The group of Ganoderma lucidum showed significant differences from the group of Ganoderma sinense. Moreover, G. lucidum in China was also different from G. lucidum in Yugoslavia. At the same time, cluster analysis successfully categorized these 31 Ganoderma strains into five groups. These results revealed the genetic diversity of Ganoderma strains and their correlation with geographic environments. It also suggested SRAP marker could be used in the taxonomic analysis of fungi. To our knowledge, this is the first application of SRAP marker on the systematics of Ganoderma strains within basidiomycetes.

Ganoderma↗
PubMed2006

Influence of PEG endgroup and molecular weight on its reactivity for lipase-catalyzed polyester synthesis.

Polycondensations were performed at 70 degrees C in bulk using physically immobilized lipase B from Candida antarctica (CAL-B) as catalyst. Study of copolymerizations between sebacic acid and PEG diols of differing Mn values (200, 400, 600, 1000, 2000, and 10 000) showed that PEG 400 and 600 were most reactive (DP(avg) up to about 6). Increasing the PEG diol chain length from 600 to 1000, 2000, and 10 000 resulted in large decreases in copolymer DP(avg) values. PEG200 diacids (i.e., HOOC-(CH2)x-O-(CH2CH2O)n-(CH2)x-COOH) were successfully synthesized where x was 1, 4, 5, 7, 9, and 11. Study of copolymerizations of these diacids with 1,8-octanediol showed that, by introduction of a five-carbon methylene spacer (x = 5), remarkable increases in the reactivity of PEG200 diacids were achieved. In addition, introduction of this spacer was also effective for increasing the reactivity of PEG diacids of higher molecular weight (i.e., PEG400, 600, and 1000). This work verified the hypothesis that, by conversion of PEG chain ends to structures more closely resembling fatty acids, modified PEG building blocks are obtained that are better recognized as substrates by CAL-B during condensation reactions.

Candida↗
PubMed2006

Factors associated with poor immunologic response to virologic suppression by highly active antiretroviral therapy in HIV-infected women.

Virologic response to highly active antiretroviral therapy (HAART) typically results in a substantial rise in CD4 cell counts. We investigated factors associated with poor CD4 response among HIV-infected women followed at 6-monthly intervals in the Women's Interagency HIV Study. Women with nadir CD4 counts < 350 cells/mm3 who achieved at least 6 months of plasma HIV RNA < 400 copies/ml were studied. Demographic, clinical, and treatment factors were compared between immunologic nonresponders, defined as the lower quartile of CD4 count change after two visits with virologic suppression (< 56 cell/mm3; n = 38), and the remaining group of responders (n = 115). Immunologic nonresponders had lower baseline HIV RNA levels and higher CD4 counts, more frequently used HAART 6 months prior to achieving consistent viral suppression, and more commonly had HIV RNA levels > 80 but < 400 copies/mL at both suppressive visits (21 vs. 7.8%, p = 0.024). In multivariate analysis, higher CD4 count and lower HIV RNA level at the last presuppressive visit were associated with immune nonresponse. We conclude that higher baseline CD4 count and lower HIV RNA level were associated with poor immunologic response to HAART in women with virologic suppression for at least 6 months. Persistent low level viremia may also contribute.

Adult↗
PubMed2006

Augmentation of revascularization and prevention of plasma leakage by angiopoietin-1 and vascular endothelial growth factor co-transfection in rats with experimental limb ischaemia.

BACKGROUND: Angiopoietin-I (Ang I) and vascular endothelial growth factor (VEGF) are endothelial cell-specific growth factors. In the current study, we tested the hypothesis that co-expression of AngI and VEGF could have an effect on development of leakage-resistant vessels. METHODS AND RESULTS: Expression plasmids, pcD2 (control plasmid), pcD2/AngI, pcD2NEGF121, or pcD2/AngI +pcD2NEGF121, were injected intramuscularly into an ischaemic hindlimb rat model, followed by electroporation. Collateral vessel development and skeletal muscle atrophy were assessed before and 7, 14, 28 days after treatment. Capillary density was significantly increased in the rats transfected with AngI or VEGF compared with that in the rats transfected with pcD2 alone (P < 0.05). Rats transfected with AngI + VEGF had the highest capillary density (P < 0.05). The mean perimeter ratio of ligated hindlimb to non-ligated hindlimb was lower with pcD2 treatment rats compared with that in the rats transfected with AngI, VEGF or AngI +VEGF (P < 0.01). Limb necrosis was observed in two of 33 control rats, but none in the AngI and/orVEGF gene-transferred rats. The amount of extravasated Evans blue in rat ligated hindlimb muscle (7 days after treatment) treated with both AngI and VEGF was significantly less compared with that in the rats transfected with VEGF alone (P < 0.01). CONCLUSIONS: The current study demonstrated that co-expression of AngI and VEGF genes in the ischaemic muscle effectively develops leakage-resistant vessels in the rat model. Therefore, this approach may provide a more appropriate therapeutic strategy in ischaemic vascular diseases.

Angiopoietin-1↗
PubMed2006

[Cardiac catheterization in neonates: experience in 26 neonates].

Cardiac catheterization is rarely performed in neonates in China. The medical records of 26 neonates who underwent cardiac catheterization in Shanghai Children's Medical Center from June 1994 to June 2004 were reviewed. These infants weighed 2300 to 4500 g (mean 3 400 +/- 500 g). Postnatal age ranged from 5 to 28 days (mean 15.2 +/- 8.7 days). Right heart ventricle angiography was performed in 24 cases, left heart ventricle angiography in 20 cases and pulmonary angiography in 6 cases. Balloon aortic septostomy (BAS) was performed in 10 cases. Twenty cases were diagnosed with complex cyanotic cardiovascular malformations and 4 with acyanotic heart disease. The implantation of a temporary cardiac pacemaker was performed in 2 cases. All diagnostic and interventional procedures were successfully performed. The catheterization-related complications occurred in 15.3% of the 26 cases, but without mortality. In conclusion, cardiac catheterization is an accurate and safe method for diagnosing complex congenital heart diseases in neonates. Interventional catheterization is useful in the treatment of complex congenital heart malformations.

Cardiac Catheterization↗
PubMed2006

[Transformation of organic matter during thermophilic composting of pig manure].

Thermophilic composting of pig manure was studied in an attempt to elaborate upon organic matter transformation during the process and provided parameters for product maturity using chemical method. The following parameters were measured in 11 samples during the 42 days of composting: organic matter, dissolved organic carbon (DOC), degradable organic matter and humic matter (HM). Organic matter decreased during composting process constantly; DOC concentration increased to maximum at 10 days and declined thereafter; degradable organic matter decreased whole composting, but they increased in start of high-temperature stage; The increasing level of HM at various stages of composting indicate the progression of humification; H/F provide information correlating to conventional chemical parameters (organic matter, DOC) of compost maturity. Moreover, H/F has correlating to degradable organic matter and HM.

Animals↗
PubMed2006

[Experimental study on a novel affinity adsorbent for removal of endotoxin in plasma].

In this paper, the adsorbent properties of Polymyxin B immobilized polystyrene microbeads to remove endotoxin from plasma were studied and the factors that affected the absorption of endotoxin were discussed. The rat models of endotoxemia were established, which were used in hemoperfusion. The experiment results indicated that the novel affinity adsorbent could remove endotoxin from plasma effectively. Moreover, the results also showed that Polymyxin B immobilized polystyrene microbeads was a fine biomaterial of hemoperfusion as well as exhibited a satisfactory blood compatibility.

Adsorption↗
PubMed2006

[Visualization of neuronal fiber tracts in white matter based on diffusion tensor].

In this paper, the basic principal or rational of diffusion tensor imaging (DTI), which develops rapidly in the field of functional magnetic resonance imaging study, is introduced. And how to reconstruct the imaging of neuronal fiber tracts in white matter with the data of DTI is described. The technique of tractography, its advantages and disadvantages are analyzed. Finally, the limitations and further applications of neuronal fiber tracts visualization are discussed.

Algorithms↗
PubMed2005

Detailed characterization of cationic hydroxyethylcellulose derivatives using aqueous size-exclusion chromatography with on-line triple detection.

A more complete understanding of polymeric, cationic cellulose derivatives, including polyquaterium-10 (Polymer JR), has become increasingly important in the eye care industry as thorough characterization of raw materials helps promote product quality and process control. Often such detailed information requires utilization of a combination of analytical techniques. In this work three Polymer JR samples with different viscosities were characterized using aqueous size exclusion chromatography (SEC) with a light scattering detector, a differential viscometer, and a differential refractometer (triple detection). Detailed molecular information such as absolute molecular weights, molecular weight distributions, intrinsic viscosities, and molecular conformations were obtained. One major challenge of analyzing cationic polymers is abnormal size exclusion separation, which could be caused by the ionic interaction between sample molecules and the column packing material. A selection of mobile phases varying in pH, buffer, organic solvent content, and molar concentration of salts was employed to evaluate the correlation of obtained molecular weight values and mobile phase composition. Universal calibration concept was used to examine the abnormal size exclusion separation phenomenon of Polymer JR samples when using different mobile phases. It was observed that the abnormal size exclusion was dependent on both the separation conditions and molecular weights of the samples. Despite the changes in separation parameters and uncharacteristic polymeric structure compared to conventional SEC samples, the use of aqueous SEC with triple detection provided reproducible and valuable molecular information of Polymer JR samples with low to medium molecular weights. By using a combination of high buffer content and adding organic solvent, the abnormal exclusion separation of high molecular weigh Polymer JR could be considerably reduced.

Calibration↗
PubMed2005

Bovine immune colostrum against 17 strains of diarrhea bacteria and in vitro and in vivo effects of its specific IgG.

Bovine colostral antibodies of cows immunized with a multivalent vaccine consisting of whole cells of 17 strains of pathogenic diarrhea bacteria were generated, and the specific IgG with high activities and titres directed against these pathogens was purified using an ammonium sulfate precipitation and verified by SDS-PAGE. We demonstrate that specific IgG has a strong activity of inhibiting in vitro growth and colonization in pathogens by agglutinating with bacteria and destroying cell walls. Normal IgG purified from non-immunized bovine colostrum is incapable of eliciting the same consequences as specific IgG. Specific IgG prevents enteroinvasive Escherichia coli/Salmonella typhi-induced diarrhea and may exert an effective protection by enhancing splenic NK cell activity, elevating IL-2 level and inhibiting excessive release of TNF-alpha in mice. Thus, the specific IgG from colostral antibodies of immunized bovine can provide effective protection or therapy for multibacteria-induced diarrhea.

Animals↗