PubMed Health⌕ Search

Biomedical subjects

Gang Wang

Publications and source records attributed to Gang Wang.

At least 181 records · Page 10Linked to original sources
PubMed2003

Tissue-engineered heart valve on acellular aortic valve scaffold: in-vivo study.

The feasibility of constructing a tissue-engineered heart valve on an acellular porcine aortic valve leaflet was evaluated. A detergent and enzymatic extraction process was developed to remove the cellular components from porcine aortic valves. The acellular valve leaflets were seeded for 7 days in vitro with cells from canine arterial wall and endothelial cells. The constructs were implanted into the lumens of 6 canine abdominal aortas to assess the reconstruction of the valve leaflets. It was found that all cellular components had been removed from the porcine aortic valves. The valve leaflets were completely reconstructed at the end of the 10th week in vivo. Scanning electron microscopy showed that the valve leaflets were partially covered with endothelial cells. It was concluded that porcine aortic valves can be decellularized by the detergent and enzymatic extraction process and it is feasible to construct a tissue-engineered heart valve in vivo on an acellular valve scaffold.

Animals↗
PubMed2003

Interaction between hepatitis C virus core protein and translin protein--a possible molecular mechanism for hepatocellular carcinoma and lymphoma caused by hepatitis C virus.

AIM: To investigate the interaction between hepatitis C virus core protein and translin protein and its role in the pathogenensis of hepatocellular carcinoma and lymphoma. METHODS: With the components of the yeast two hybrid system 3, "bait" plasmids of HCV core the gene was constructed. After proving that hepatitis C virus core protein could be firmly expressed in AH109 yeast strains, yeast two- hybrid screening was performed by mating AH109 with Y187 that transformed with liver cDNA library plasmids-pACT2 and then plated on quadruple dropout (QDO) medium and then assayed for alpha-gal activity. Sequencing analysis of the genes of library plasmids in yeast colonies that could grow on QDO with alpha-gal activity was performed. The interaction between HCV core protein and the protein we obtained from positive colony was further confirmed by repeating yeast two - hybrid analysis and coimmunoprecipitation in vitro. RESULTS: A gene from a positive colony was the gene of translin, a recombination hotspot binding protein. The interaction between HCV core protein and translin protein could be proved not only in yeast, but also in vitro. CONCLUSION: The core protein of HCV can interact with translin protein. This can partly explain the molecular mechanism for hepatocellular carcinoma and lymphoma caused by HCV.

Carcinoma, Hepatocellular↗
PubMed2003

[Cloning of genes transactivated by hepatitis B virus X protein].

OBJECTIVE: To construct a subtractive cDNA library of genes transactivated by hepatitis B virus X protein (HBX) using suppression subtractive hybridization (SSH) technique and to clone genes associated with HBX transactivating function. METHODS: The mRNA was isolated from HepG2 cells transfected with pcDNA3.1(-)-X and pcDNA3.1(-) empty vector respectively, then cDNA was synthesized. After restriction enzyme RsaI digestion, a number of small size cDNA was obtained. Then tester cDNA was subdivided into two portions and each was ligated with different cDNA adaptor. After tester cDNA was hybridized with driver cDNA twice and underwent nested polymerase chain reaction (PCR) twice the production was subcloned into T/A plasmid vectors to set up the subtractive cDNA library. Amplification of the library was carried out with E. coli strain JM109, some cDNA was sequenced and analyzed in GenBank with Blast. RESULTS: The subtractive cDNA library of genes transactivated by HBX was constructed. The amplified library contained 85 positive clones, and colony PCR showed that these clones contained 200-1000 bp inserts. 65 clones were analyzed by sequencing and bioinformatics, which suggested nineteen known genes and fifteen genes with unknown function. CONCLUSION: A subtractive cDNA library of genes transactivated by HBX using SSH technique has been constructed successfully, which may bring some new clues for studying the biological functions of HBX and the pathogenesis of hepatoma.

Cloning, Molecular↗
PubMed2003

[Method on PCR detection of bovine materials in animal feedstuffs].

The reliable, simple and easy to operate methods were established to extract DNA from animal feedstuffs. A set of PCR primers were designed for bovine specific mitochondrial DNA sequence. With this method, PCR can be successfully utilized to evaluate the presence of bovine materials in animal feedstuffs. A set of commonly used primers of 18Sr-RNA were designed as endogenuous reference gene, and check on the quality of template extraction from animal feedstuffs, and avoid the result of false negative. PCR amplification condition was one cycle of 96 degrees C for 2 min, then 35 cycle of (94 degrees C for 40s, 60 degrees C for 50s, 72 degrees C for 60s), and finally one cycle of 72 degrees C for 5 min. PCR amplified specific gene sequence 271 bp for bovine materials from animal feedstuffs.

Animal Feed↗
PubMed2003

[Study on correlation between bone mineral density and syndrome type of TCM in patients with chronic obstructive pulmonary disease].

OBJECTIVE: To explore the correlation between bone mineral density and Syndrome type of TCM in patients with chronic obstructive pulmonary disease (COPD) for providing the base of clinical integrative traditional Chinese and western medical therapy for the disease through the Syndrome typing and determination of changes in bone metabolism and bone density. METHODS: Bone mineral density (BMD) of lumbar vertebrae 2-4, femoral neck, Ward's triangle and trochanter in 27 COPD male patients, 25 male control subjects and 25 healthy persons were determined using dual energy X-ray absorptiometry, patient's Syndrome type, their blood levels of total protein, albumin, alkaline phosphatase, bone glaprotein, hydroxyproline, calcium, phosphate, urine levels of calcium/creatine and phosphorous/creatine as well as arterial blood gas were also determined. RESULTS: The BMD in COPD patients accompanied with respiratory failure or with course > 10 years was higher than that in COPD patients without respiratory failure or with course < or = 10 years, BMD in COPD patients of Fei-Pi-Shen type was lower than that in those of Fei-Pi, but the urine hydroxyprdine in the former was higher than that in the latter (all P < 0.05). CONCLUSION: (1) COPD is a risk factor for osteoporosis; (2) Shen Deficiency is the key and nucleus of secondary osteoporosis to COPD; (3) It is inferred that early regulation of Shen may be facilitated to prevent osteoporosis in COPD patients.

Aged↗
PubMed2003

Glucocorticoid modulation of extracellular signal-regulated protein kinase 1/2 and p38 in human ovarian cancer HO-8910 cells.

OBJECTIVE: To investigate the signaling pathway through testing the effects of dexamethasone (Dex) on the activation of the extracellular signal-regulated protein kinase 1/2 (ERK1/2) and p38 kinase (p38) in HO-8910 cells. METHODS: Activation of the ERK1/2 and p38 was detected by Western blotting using the antibodies against the total ERK1/2 and p38 mitogen-activated protein kinases (MAPKs) protein and the phosphorylated forms of them. RESULTS: Dex could suppress the activation of ERK1/2, while enhance the activation of p38 rapidly and strongly in a dose- and time- dependent manner. Neither effect could be blocked by RU486, the antagonist of glucocorticoid receptor (GR). CONCLUSION: Dex has rapid effects on the activation of ERK1/2 and p38, and these effects are not mediated by GR.

Cell Division↗
PubMed2003

[An electron microscope observation for the abnormal ultrastructure of the connecting piece in human spermatozoa from infertile painters].

OBJECTIVES: To investigate possible abnormalities of the sperm neck in eight infertile painters observed by transmission electron microscope. METHODS: Spermatozoa from 8 infertile painters (21-32 years old) were observed by transmission electron microscope. RESULTS: The abnormalities of the connecting piece could be divided into 6 types, among which the anomaly of the connecting piece concomitant with a true nuclemalamic condition was the most serious. CONCLUSIONS: The abnormalities may be related to expression obstacles of nuclear genome and mitochondrial genome, and to anomalous cellular signal transduction during spermiogenesis as well.

Adult↗
PubMed2003

Screening of augmenter of liver regeneration-binding proteins by yeast-two hybrid technique.

OBJECTIVE: To investigate the biological function of augmenter of liver regeneration (ALR), we used yeast-two hybrid technique to detect proteins in hepatocytes interacting with ALR. METHODS: ALR bait plasmid was constructed by using yeast-two hybrid system 3, then transformed into yeast AH109. The transformed yeast was mated with yeast Y187 containing liver cDNA library plasmid in a 2XYPDA medium. Diploid yeast was plated on a synthetic dropout nutrient medium (SD/-Trp-Leu-His-Ade) containing x-alpha-gal for selection and screening. After extracting and sequencing of the plasmid from blue colonies. Analysis was performed by bioinformatics. RESULTS: Of 36 colonies sequenced, 14 are metallothionein, 12 albumin, and 3 selenoprotein P. One colony is a new gene with unknown function. CONCLUSION: The successful cloning of gene of ALR interacting protein has paved the way for studying the physiological function of ALR and associated proteins.

Animals↗
PubMed2003

[Construction of subtracted cDNA library in human Jurkat T cell line induced by arsenic trioxide in vitro].

OBJECTIVE: To understand the differentially expressed genes in human T lymphocytes induced by arsenic trioxide (As(2)O(3)) and to explore mechanism of its immunotoxicity and immune suppression. METHODS: Human Jurkat T cell line was treated by arsenic trioxide (5 micromol/L, 24 h) in vitro, as a sample model. Then, the differentially expressed genes were cloned and the subtractive cDNA library from Jurkat T cell line was constructed by suppression subtractive hybridization (SSH). Polymerase chain reaction (PCR) and sequencing techniques were applied to identify positive clones. RESULTS: The forward subtracted cDNA library contained differentially expressed genes from Jurkat T cell line induced by arsenic trioxide was constructed, including 29 different gene fragments and only replicated one in the subtracted cDNA library identified by PCR and sequencing analysis. These gene sequences were 95%-100% analogous to the genes in public database (GenBank/EMBL). The cDNA library contained oxidative metabolic genes in mitochondria (triose phosphate dehydrogenase, NADH4, pyrophosphate synthase, 16S rRNA ribosome, succinate-CoA ligase and ATP synthase 6); transcriptional and translation genes poly (A) binding protein, t-RNA-guanine transglycoslase, ribosomal protein L23, ribosomal protein S15A, eukaryotic translation initiation factor 3, Rab interaction protein 5, splicing factor-arginine serine rich 5, and ADP-ribosylation factor-like 6 interacting protein), oxide stress related genes (ferritin high chain and high-mobility group protein 2); protein activating and signaling pathway related genes (casein kinase, serine kinase 2 and phosphatidylinositol-four-phosphate adaptor protein-1-associated protein); cell differentiation and apoptosis associated genes (NB4 cell apoptosis related protein and myeloid differentiation primary response protein) and five genes with unknown function (KIAA0092, CGI-147protein, GCI-35, nucleolar phosphoprotein Nopp34 and Mus muscular partial mRNA for hypothetical protein), as well as a novel gene unmatched to the sequence in GenBank. CONCLUSIONS: The forward subtracted cDNA library contained differentially expressed genes from Jurkat T cell line induced by arsenic trioxide was successfully constructed. And, genes not involved in previous research on arsenic were found. Results of analysis for these genetic function suggested that there should be many genes involved in process of T lymphocytes apoptosis or injury induced by arsenic trioxide and that there should still be many genes associated with arsenic that were not reported in the past.

Antineoplastic Agents↗
PubMed2003

[Left ventricular aneurysmectomy with geometric reconstruction].

OBJECTIVE: To summarize the experience in performing left ventricular aneurysmectomy (LVA) with geometric reconstruction and concomitant coronary artery bypass grafting (CABG) without mortality. METHODS: Forty-two patients underwent LVA with geometric reconstruction and concomitant CABG. Forty-one patients were male, one was female with mean age of (55.5 +/- 2.4) years (40 - 68 years). Preoperative cardiac function was NYHA class III in 32 patients and class IV in 10. Thirty-eight patients had unstable angina pectoris and 10 had the history of severe ventricular arrythmia. Eight patients had ventricular tachycardia. Preoperative left ventricular ejection fraction (LVEF) was 41% (17% - 63%), LVEF was less than 40% in 29 cases. Left ventricular anatomic aneurysms were confirmed by ventriculography. Thirty-three cases underwent Jatene technique; 8 cases, Dor technique, and 1 case, Cooley technique. Mural thrombi were found in 21 patients and were completely removed. CABG was concomitantly performed in all patients. All of the left anterior descending artery was bypassed with left internal mammary artery and the other target vessels with saphenous vein. Mean cardiopulmonary bypass time was (135 +/- 11) minutes and aortic clamping time was (78 +/- 10) minutes. RESULTS: No hospital mortality occurred and all patients were discharged. Postoperative reexploration for bleeding in 1 patient. The diameter and end systolic and diastolic volume of left ventricle were significantly decreased to nearly normal after operation. Operative ejection fraction had a tendency to increase but without significance (P > 0.05). CONCLUSIONS: LVA with geometric reconstruction and concomitant CABG could not only improve heart function but also eliminate ventricular arrythmia. The clinical result was excellent.

Adult↗
PubMed2003

[Oxidation treatment of formaldehyde-containing wastewater by electro-Fenton method].

The mechanisms of affecting factors in treating formaldehyde-containing organic wastewater by electro-Fenton reactor which had granular carbon as the filled electrode were investigated. The optimal operating conditions determined by orthogonal experiments and individual factor experiments were as following: 90 min, 25 V, 30 degrees C-40 degrees C, insulating carbon content 40%, Fe2+ concentration 300 mg/L at pH < 3.5. Formaldehyde degradation mechanisms were proposed after analyzing the oxidation products with UV absorbance spectrum. Experiment of treating the actual wastewater using this method were also performed. The removal rates of formaldehyde and CODCr were about 90%, 30%, respectively. In addition, the operating cost was 42.3% less than that of treatment by Fenton method.

Electrochemistry↗
PubMed2003

[Effects and holding time of hyperbaric oxygen on human severe periodontitis].

OBJECTIVE: This paper studied the therapeutic effects and holding time of hyperbaric oxygen (HBO) on human severe periodontitis. METHODS: 30 cases with periodontitis were selected and randomly divided into 2 groups, i.e. the HBO group and control group. For HBO group, they were exposed to a pressure of 0.25 MPa. For control group, they were rinsed with gargle. Gingival indices (GI), sulcus bleeding indices (SBI), plaque index (PLI), probing depth (PD), attachment loss (AL) and gingival crevicular fluid (GCF) were measured during both the first and last clinical visits, and 1 year after HBO therapy. The gingival blood flow (GBF) were measured by Laser Doppler Flowmeter. RESULTS: HBO can decrease GI of patients with periodontitis by 1.1 decrease SBI by 1.2, lower PD and AL by 0.7 mm, decrease the volume of GCF by 2.0, and significant differences could be seen in the above indices between pre and post HBO therapy. The GBF had a 1.8 folds increase after HBO exposure. GI and SBI one year after HBO therapy were larger than that of the time after HBO therapy. There were no significant differences in the PLI, PD, AL, GCF, GBF between post HBO therapy and 1 year after HBO therapy. CONCLUSION: HBO had good therapeutic effects on human severe periodontitis, the effects can keep more than 1 year.

Adult↗
PubMed2003

[Biological characteristics and spatial distribution of Chorthippus dubius population on high mountain grassland].

Based on rearing observations and surveys in Ganjia High-Mountain Grassland, Xiahe County, Gansu Province, the occurrence period, ingestion capacity, spatial pattern, and dynamics of Chorthippus dubius were studied. The results showed that this grasshopper had only one generation in a year. Its eggs wintered in the soil, and in the next year, they began to hatch from the last ten days of May to the first ten days of June. The hatching peak took place from the middle ten days to the last ten days of June. The majority of the nymphs possessed 4 instars, and about 23% of them possessed 5 instars. The developmental duration of the nymphs underwent about 70 days, and the longevity of the adults lasted for 42 days. The ingestion capacity of the nymphs was 368. 3 mg, and that of the adults was 743.8 mg. The spatial pattern of 1-2 instars belonged to an aggregated distribution, and that of 3-5 instars belonged to even and random distribution.

Animals↗
PubMed2003

[Construction of a plant expression vector with tomato transcription factor gene Pti5 and studies on transgenic tobaccos].

The plasmid pBI121UCH1 carrying Pti5-VP16 gene under the control of the cauliflower mosaic virus 35s promoter was constructed. Leaf segments of tobacco SRI were infected by Agrobacterium tumefaciens EHA105 with plasmid pBI121UCH1, from which kanamycin resistant plants were obtained. PCR and Southern analysis proved that the Pti5-VP16 gene was integrated into the genomes of the tobacco plants. The disease resistance assay showed that the disease resistance was enhanced in the transgenic tobacco plants.

English Abstract↗
PubMed2002

Redirecting migration of T cells to chemokine secreted from tumors by genetic modification with CXCR2.

T-cell-based immunotherapies provide a promising means of cancer treatment although durable antitumor responses are infrequent. A potential reason for these shortcomings may lie in the observed lack of trafficking of specific T cells to tumor. Our increasing knowledge of the process of trafficking involving adhesion molecules and chemokines affords us the opportunity to intervene and correct deficiencies in this process. Chemokines can be expressed by a range of tumors and may serve as suitable targets for directing specific T cells toward tumor. We initially sought to identify which chemokines were produced by a range of human tumor cell lines, and which chemokines and chemokine receptors were expressed by cultured T cells. We identified two chemokines: Growth-Regulated Oncogene-alpha (Gro-alpha; CXCL1) and Regulated on Activation Normal T Cell-Expressed and Secreted (RANTES; CCL5), to be secreted by several human tumor cell lines. Expression was also detected in fine-needle aspirates of melanoma from patients. In addition, we determined the expression of several chemokine receptors on cultured human T cells including CCR1, CCR2, CCR4, CCR5, CXCR3, and CXCR4. Cultured, activated human T cells expressed the chemokines lymphotactin (XCL1), RANTES, macrophage inflammatory protein-1 alpha (MIP-1 alpha; CCL3) and MIP-1 beta (CCL4), but no appreciable Gro-alpha. In a strategy to direct T cells toward chemokines expressed by tumors we chose Gro-alpha as the target chemokine because it was produced by tumor and not by T cells themselves. However, T cells did not express the receptor for Gro-alpha, CXCR2, and therefore, T cells were transduced with a retroviral vector encoding CXCR2. Calcium ion mobilization, an important first step in chemokine receptor signaling, was subsequently demonstrated in transduced T cells in response to Gro-alpha. In addition, Gro-alpha was chemotactic for T cells expressing CXCR2 in vitro toward both recombinant protein and tumor-derived chemokine. Interestingly we demonstrate, for the first time, that Gro-alpha was able to induce interferon-gamma (IFN-gamma) secretion from transduced T cells, thereby extending our knowledge of other potential functions of CXCR2. This study demonstrates the feasibility of redirecting the migration properties of T cells toward chemokines secreted by tumors.

Calcium↗
PubMed2002

Supramolecular self-assembly of nanotubes and supercoils from long-chain derivatives of pyrimindinetrione and triazine.

The self-assembly of two complementary components, 5-(4-N-methyl-N-dodecylaminobenzylidene)-2,4,6-(1H,3H)-pyrimidi-netrione (1) and 4-amino-2,6-didodecylamino-1,3,5-triazine (2) was found to result in the formation of a hollow supramolecular nanotube with about 6 nm in diameter and hundreds of nanometers in length as observed directly by transmission electron microscope (TEM). X-ray diffraction patterns indicate that a periodical layered structure with a d spacing of 0.49 nm in the nanotube exists. If staining treatment were employed in TEM observations, the self-assembly was found to show a supercoil structure about 300 nm in diameter.

Journal Article↗