Biomedical subjects

Yan Wang

Publications and source records attributed to Yan Wang.

At least 415 records · Page 23Linked to original sources

PubMed2004

[Study of immune responses induced by human papillomavirus type 18 L1-E6 and L1-E7 chimeric gene DNA vaccines in mice].

AIM: To examine the humoral and cellular immunoresponses induced by HPV18 L1-E6 and L1-E7 chimeric gene DNA vaccines in mice. METHODS: 54 BALB/c mice were divided into 9 groups randomly, and then vaccinated with various recombinant plasmids(pVAX1-L1-E6M3 or pVAX1-L1-E7M3) and immune adjuvants (pLXHDmB7-2 or LTB) through different administration routes (intramuscular or intranasal). After the third inoculation, blood samples were taken to measure specific antibody, and footpad swelling test was used to detect delayed-type hypersensitivity(DTH). Mice were killed and spleens were taken to prepare single spleen cell suspension for lymphocyte proliferation assay and CD4(+)/CD8(+), IFN-gamma(+) or IL-4(+) T cells double staining FACS assay. And then the pathological changes of the swollen footpad were observed. RESULTS: Compared with control, significant immunoresponses were observed in different experimental groups. The level of specific serum IgG against HPV in experiment groups was much higher than that of control group, and intramuscular immunization group had the highest antibody level. The footpad from immunized mice injected with virus-like particles was swollen and harden, and a large amounts of mononuclear cells can be seen in the footpad tissues. Intramuscular immunization groups were superior to intranasal immunization groups in DTH response, splenocyte proliferation and CD8(+) IFN-gamma(+) cell number, while CD4(+) IL-4(+) cell number was higher in intranasal immunization groups. The immunization groups using pLXHDmB7-2 as adjuvant were superior to other groups in immune responses. CONCLUSION: The recombinant plasmids could induce strong humoral and cellular immunoresponses in mice. Costimulatory molecule B7-2 could enhance the immune responses against HPV18 induced by the L1-E6 and L1-E7 DNA vaccines when used as an adjuvant.

Animals↗

PubMed2004

[Biological effects of tetracycline on cultured human periodontal fibroblasts].

OBJECTIVE: To explore the biological effects of tetracycline on cultured human periodontal ligament fibroblasts (HPDLFs). METHODS: Increasing concentrations of tetracycline (1, 5, 20, 100, 500, 2500 microg/ml) were added to the medium of cultured HPDLFs, respectively. After co-incubated for 2 days, cell morphology was observed under reverse microscope, meanwhile, cell proliferation activity was assayed using MTT, the total amount of protein was detected with Coumassie Bright Blue method and DNA synthesis was measured by 3H-TdR. RESULTS: Over a concentration range of 1 to 100 microg/ml, cells demonstrated a normal appearance, spindle or fusiform shaped. Moreover, at a concentration range of 20 to 100 microg/ml, tetracycline significantly enhanced the proliferating activity and biosynthesis of HPDLFs (P < 0.01). However, higher concentration (2500 microg/ml) not only changed cell morphology, but also significantly inhibited cellular activity. CONCLUSION: The results suggested that proper doses of tetracycline could promote proliferation and biosynthesis of HPDLFs while higher concentrations of tetracycline had cytotoxic effect.

Cells, Cultured↗

PubMed2004

[Regulation for distribution of metastatic cervical lymph nodes of 512 cases of nasopharyngeal carcinoma].

BACKGROUND & OBJECTIVE: To identify the target volume of radiotherapy is more and more important. This study was designed to explore the regulation for the distribution of metastatic cervical lymph nodes of nasopharyngeal carcinoma (NPC) and to recommend the delineation of clinical target volume of the neck for three-dimensional conformal radiotherapy in NPC. METHODS: From Jan. 2003 to Jun. 2004, 512 of cases of NPC, histologically diagnosed, received enhanced transversal CT scan. The cervical node was divided into six levels (I-VI) plus retropharyngeal nodes according to RTOG guidelines proposed in 2003. RESULTS: Of 512 patients, 328 (64.1%) had cervical lymphadenopathy at presentation. Of the 328 neck positive cases, the node involvement was unilateral in 61.3% patient and bilateral in 38.7%. 328 (64.1%) cases showed enlargement of retropharyngeal node, and unilateral 50.9%, bilateral 49.1%. The involvement for levelIto level VI and retropharyngeal area in node-positive cases was 3.0%, 97.9%, 46.0%, 9.5%, 13.7%, 0% and 74.4%. Of the node-positive patient, the incidence of skip metastasis was from 4.6% to 6.5%. 25.3% of the node-positive cases showed involvement, which is beyond CTV for the neck of stage N0 recommended by RTOG. CONCLUSIONS: The cervical node involvement of NPC is spread orderly down the neck, and the incidence of skip metastasis is lower. Retropharyneal node was the first echo node to metastases of NPC. The retropharyngeal node, level II, and level III were the most frequently involved area. Level Ia and level VI were never involved. There are few cases with positive nodes beyond CTV for the neck of stage N0 recommended by RTOG. Our data is helpful for the delineation cervical target in the 3-D conformal radiotherapy of NPC.

Adolescent↗

PubMed2004

[Report of 8 cases of bcr-abl gene positive thrombocytosis and review of the literature].

OBJECTIVE: To analyse the features of 8 cases of Bcr(+) thrombocytosis. METHODS: The clinical and hematological features and therapeutic outcomes were studied retrospectively in 8 Bcr(+) thrombocytosis and compared with essential thrombocytosis (ET) and chronic myeloid leukemia-chronic phase thrombocytosis (CML-CP-T). BCR-ABL fusion gene was detected with PCR. RESULTS: (1) Except for the presence of BCR-ABL fusion gene, there was no significant difference in clinical and hematological features and therapeutic outcomes between thrombocytosis with or without BCR-ABL. (2) The Bcr(+) thrombocytosis differed from CML-CP-T in the following aspects: female predominance, milder or no splenomegaly, peripheral leukocytes count < 40 x 10(9)/L, less or no basophilia and fewer immature granulocytes in peripheral blood, bone marrow granulocytic and/or megakaryocytic lineage hyperplasia, normal or increased neutrophil alkaline phosphatase score and less blastic transformation. CONCLUSION: Bcr(+) thrombocytosis may be considered as a new member of chronic myeloproliferative diseases, a variant of essential thrombocythemia.

Adult↗

PubMed2004

[Study on the polymorphism of angiotensin converting enzyme genes and serum angiotensin II level in patients with obstructive sleep apnea hypopnea syndrome accompanied hypertension].

OBJECTIVE: To explore the relationship of the ACE gene insertion/deletion (I/D) polymorphism and the rennin-angiotensin system in the pathogenesis of hypertension in OSAHS. METHOD: Gene DNA was extracted from blood samples and amplified by polymerase chain reaction (PCR). The distribution of.the ACE gene I/D allele and genotypes were analyzed in 30 OSAHS with hypertension patients, 30 normotensive OSAHS patients and 30 healthy control group without cardiovascular diseases. The serum level of angiotensin II were also measured in all subjects by angiotensin II enzyme immunoassay kit. RESULT: The frequency of II genotype and I allele were significantly higher in the OSAHS accompanied hypertension patients than those in the healthy controls (chi2=9.88, chi2=16.13, P<0.01, respectively) and in the normotensive OSAHS patients (chi2=5.67, P<0.05, chi2=8.61, P<0.01). The frequency of II genotype and I allele had no significantly different between the normotensive OSAHS patients and the healthy controls (P>0.05). The serum level of angiotensin II was significantly higher in both OSAHS patients with and without hypertension than that in the healthy control (t=3.66, t=3.23, respectively P<0.01). Whereas the serum level of angiotensin II have no significantly different in the OSAHS patients with and without hypertension (P>0.05). CONCLUSION: These results indicate that the higher frequency of ACE gene I allele and genotype are closely associated with OSAHS patients accompanied hypertension. It is one of the important risk factors for the genesis of hypertension in OSAHS. The activity of rennin-angiotension system is higher in the OSAHS may have contribute to OSAHS-induced hypertension.

Adult↗

PubMed2004

[Transient expression of Echinococcus granulosus Eg95 DNA vaccine and induction of immune response in mice].

OBJECTIVE: To detect the in vitro expression of pcDNA3-Eg95 and to observe the immunological effect of the Eg95 DNA vaccine in mice. METHODS: The eukaryotic recombinant plasmid pcDNA3-Eg95 was transfected into HeLa cells with liposome-mediated method. RT-PCR, ELISA and Western blotting were used to analyze the expression of Eg95 mRNA and Eg95 protein, respectively. The BALB/c mice were immunized by pcDNA3-Eg95. Anti-Eg95 IgG and IgG2a in murine serum were determined by ELISA. The proliferation activity of spleen T lymphocytes was tested using MTT assay. RESULTS: Using RT-PCR method, the expression of Eg95 mRNA was confirmed in vitro. The results of ELISA and Western blotting showed that there was a specific Eg95 protein, which can be specifically recognized by anti-sera of Eg95-prokaryotic-expressing protein in pcDNA3-Eg95 transfected HeLa cell lysis. The specific IgG was induced during the 3rd week and continued to increase until week 10. IgG2a was detected after 2 weeks and maintained a higher level till week 10. There was a significant difference of IgG2a level between pcDNA3-Eg95 immunized group and pcDNA3 control (P<0.01). In spleen T cell proliferation response, the stimulation index (SI) in pcDNA3-Eg95 group was higher than that of vector control (P<0.01). CONCLUSION: Eg95 DNA vaccine can induce significant cellular and humoral immune response in mice.

Animals↗

PubMed2004

[Experimental study on anticancer effect of curcumin on Raji cells in vitro].

OBJECTIVE: To study the anticancer effect and mechanism of curcumin on Raji cells in vitro and compared the cytotoxicities of curcumin on Raji cells and normal human peripheral blood mononuclear cell (PBMC). METHODS: The effects of curcumin on proliferation of Raji cells and human PBMC were tested by MTT assay, its effects on apoptosis of them were determined by Annexin-V/PI double-labeled cytometry and TUNEL, and its effects on DNA distribution in Raji cells was studied by PI single labeled cytometry. RESULTS: Curcumin showed marked inhibition on proliferation of Raji cell, could induce Raji cell apoptosis in time- and dose-dependent manner. After curcumin treatment, the cell cycle of Raji cells was blocked in G0/G1 and G2/M phase and those in the S phase decreased proportionally. But curcumin showed no significant effect on inhibiting proliferation or inducing apoptosis on human PBMC. CONCLUSION: Curcumin could regulate the cell cycle of Raji cells and induce its apoptosis, so as to inhibit its proliferation, but with no significant cytotoxicity on human PBMC. It selectively affects the tumor cell.

Antineoplastic Agents, Phytogenic↗

PubMed2004

[Effect of staining method and sintering temperature on the color of porcelain-fused-to-metal restorations].

PURPOSE: To investigate the effect of staining method and sintering temperature on the color of porcelain-fused-metal restorations. METHODS: 40 cylindrical stained porcelain-metal specimens of 15 mm in diameter and 6 mm in height were fabricated with customized mould, consisting of 2 mm Ni-Cr metal, 1 mm opaque porcelain, 2 mm dentine porcelain and 1 mm enamel porcelain. The specimens were prepared by 5 techniques, 8 for each group. Group A: internal staining, Group B: external staining, 900 degrees centigrade sintering temperature was used in both A and B group; Group C to E: external staining, with the sintering temperature of 880 degrees centigrade, 900 degrees centigrade and 920 degrees centigrade respectively. Sofu A2 porcelain and Sofu 44 stain system were used for the study. Using standard white plate as a reference, colors (L*,a*,b* coordinates) of the specimens were measured with a computerized colorimeter. Student's t test and one way ANOVA were used to analyze the data. RESULTS: DeltaE, b* and Delta C(ab)* of Group B (external staining) and group A (internal staining) were 43.72 +/- 2.99/26.51 +/- 1.64/31.31 +/- 2.48 and 39.71 +/- 1.78/23.69 +/- 0.36/26.55 +/- 2.16, respectively. The values of the former group were significantly higher than that of the latter (P < 0.05); For Group C to E, there were no significant differences in all the color parameters. CONCLUSIONS: Staining method has a significant effect on the color parameters of porcelain-fused-to-metal restorations; For external staining, within the clinically-used range, changing the sintering temperature does not have an obvious effect on the color.

Color↗

PubMed2004

[Purification and characterization of nano Al13 species in polyaluminum chloride].

The polynuclear Keggin species, Al12AlO4(OH)24(H2O)12(7+) (Al13), was firstly separated and purified from polyaluminum chloride (PAC) by the ultra-filtration and column chromatography method. The Al13 yield was characterized by Al-Ferron timed complexation spectrophotometry, 27Al-NMR, TEM and ZATESIZER 3000HSA. The results showed that the purified sample by the ultrafiltration method influenced by membrane pore radius and the concentration of PAC solution. High purity Al13 would be obtained by choosing appropriate membrane and concentration of PAC. When using the column chromatography method, the bigger molecules were eluated first, then the smaller ones. Al13 would be obtained by taking out the middle educt. From Al-Ferron timed complexation spectrophotometry, it was found that the obtained sample contained more than 90% and 100% of Al13 by using the two methods mentioned above respectively. The TEM and ZATESIZER 3000HSA results showed that Al13 was mainly aggregated as line type and branch type in B = 2.5 solution, and the size was about several decade and several hundred nm.

Aluminum↗

PubMed2004

[Differentially expressed genes in human giant-cell lung cancer lines with different metastatic potentials].

OBJECTIVE: To screen genes differentially expressed in two human giant-cell lung cancer lines of same origin but with different metastasis potentials. METHODS: Suppression subtractive hybridization (SSH) was done twice on two giant-cell lung cancer lines, PLA-801C and PLA-801D (hereafter abbreviated as C and D), of same origin but with low (C) and high (D) metastatic potentials. In the first round, SSH C was used as tester and D as driver, while in the second round, the tester and driver were interchanged. The sequences acquired from both rounds of SSH were spotted on glass slides respectively and screened by hybridizing with two-color fluorescence probes. Clones that had different expression levels on chips were also confirmed by RNA dot blot or Northern blot. RESULTS: There were 16 sequences with high expression in C as compared to those in D, and 79 sequences with high expression in D compared to those in C. After sequencing, most of them were found to be highly homologous to those encoding the following proteins: (1) cytokines and their receptors; (2) kinases and related proteins; (3) other proteins including enzymes, heat shock proteins, receptors, proteins of cell skeleton and mitochondria, products of oncogenes, etc; (4) some proteins deduced from gene sequences with yet unknown functions. CONCLUSION: The alterations in expression of some known genes, including HSP70, AXL receptor tyrosine kinase and 14-3-3zeta, might have impact on metastasis of giant-cell lung cancer. Whether some differentially expressed genes newly revealed are metastasis-related needs further study.

14-3-3 Proteins↗

PubMed2004

[Tumor necrosis factor alpha and myocardial matrix metalloproteinases in left ventricular remodeling].

OBJECTIVE: The cytokine tumor necrosis factor (TNF) alpha has been causally linked to left ventricular (LV) remodeling, but the molecular basis for this effect is unknown. It is essential to study the changes of plasma levels of TNF alpha and matrix metalloproteinase-2,3,9 (MMP-2,3,9) expressions in myocardium during congestive heart failure (CHF). METHODS: Plasma levels of TNF alpha were measured with enzyme-linked immunoassay in CHF patients of various degrees and in healthy controls. Using Western blotting assay, we detected the protein expressions of MMP-2,3,9 on myocardial tissue in CHF patients and in healthy controls. Cardiac function parameters were measured with echocardiographic studies. RESULTS: Plasma levels of TNF alpha increased significantly in patients with CHF (P < 0.05 or < 0.01). The protein expressions of MMP-2,3,9 were significantly higher in patients with CHF than in controls (P < 0.05 or < 0.01). The higher the degree of CHF, the greater the numbers of expressions. No changes of MMP-2 could be found between the controls and CHF patients of NYHA II. There was a positive correlation between plasma levels of TNF alpha and the protein expressions of MMP-2,3,9 (P < 0.01 or < 0.001). CONCLUSIONS: It is suggested that alterations of TNF alpha may stimulate the expressions of MMPs, contribute to myocardial remodeling and lead to the development and progression of congestive heart failure. These changes may induce a direct effect on the progression and deterioration of heart failure.

Adult↗

PubMed2004

[The polymorphism distribution of DYS413 locus in Mongolians (Inner Mongolia)].

In order to provide the evidence for the application of DYS413(YCAIII) locus in forensic medicine and population genetics by investigating its polymorphism in the Mongolians lived in the Inner Mongolia Autonomous Region, China, to collect 120 unrelated male Mongolians' venous blood, who lived in the Inner Mongolia Autonomous Region, and the blood is anticoagulant with EDTA, then to extract DNA by using the method of phenol-chloroform and amplify the DYS413 locus with PCR. The products were separated with 6% non-denatured polyacrylamide/bisacrylamide gels(19:1) electrophoresis and stained with 1 per thousand nitrate of silver(AgNO(3)). There are total 30 different haplotypes in Mongolians, the frequencies are from 0.0007 to 0.01361, the HD(haplotype diversity) is 0.94054. It shows that DYS413 locus is high valuable in the application of forensic medicine and population genetics.

Asian People↗

PubMed2004

[Study of polymorphism at new Y-STR DYS605 in a Chinese Han population of Shanxi].

We study the polymorphism at DYS605 ,a new tetranucleotide Y-STR locus,in a Chinese Han population of Shanxi to meet the need of more genetic markers in forensic practice and genetic analysis. DNA were extracted from 128 unrelated male venous blood, and amplified using GDB primers. PCR products were detected using non-denaturing polyacrylamide gel electrophoresis and silver staining. Five alleles named 22,21,20,19,18 were observed with frequency of 0.0156;0.1797;0.4531;0.2891;0.0625. PCR products were not found in female DNA. Using a long enough gel for a long electrophoresis time is strongly encouraged because the rung between allele 20 and allele19 is smaller than expected. Allele sequences show that the repetitive units of DYS605 were composed with the variant units and non-variant units.

Alleles↗

PubMed2004

[Construction of recombinant replication competent plasmids containing HBV genome with mutations of precore and basic core promoter].

OBJECTIVE: To construct a series of recombinant replication competent plasmids of hepatitis B virus (HBV) full-length genome with varying mutations of precore and basic core promoter. METHODS: The plasmid containing the entire HBV (1.2 copies) genome was used to construct objective plasmids. The objective competent vectors were constructed by molecular cloning and PCR-based site-directed mutagenesis in vitro and confirmed with sequence analysis. After introducing the plasmids into hepatocellular carcinoma cell line (Huh7) by calcium phosphate transfection, the culture supernatant was collected to detect HBsAg and HBV DNA to analyze viral replication and expression. RESULTS: Ten competent vectors with varying precore and basic core promoter mutations were constructed. After transfecting into Huh7, the vectors replicated and secreted viral particles. CONCLUSIONS: Ten full-length competent HBV recombinants were obtained, which were harbouring varying mutations within precore and basic core promoter.

Carcinoma, Hepatocellular↗

PubMed2004

[Therapeutic effect of levamisole plus HBV vaccine and dipyridamole on patients chronically infected by HBV with precore mutation].

OBJECTIVE: To evaluate the incidence of precore mutation in HBeAg negative HBV infected patients and the therapeutic effect of the immune therapy (levamisole + HBV vaccine + dipyridamole) on patients chronically infected by HBV with precore mutation. METHODS: The precore region of HBV from the HBeAg (-) chronic hepatitis patients was sequenced and the patients suffered from HBV with precore mutation were treated with immune therapy. RESULTS: The precore mutation rate was 10/12. The therapeutic effect of the immune therapy on the precore mutation patients (5/7) was better than that on the HBsAg(+), HBeAg(+) patients (2/11), P less than 0.05. CONCLUSION: The precore mutation rate was quite high in the HBsAg(+), HBeAg(-) patients we studied. The immune-therapy has some therapeutic effects on the patients with precore mutation. But the number of cases was too small, further study is needed.

Adolescent↗

PubMed2004

[Preparation of a novel activated carbon coating fiber for solid phase micro-extraction and its application for halocarbon compound analysis in water].

A novel activated carbon coating fiber used for solid phase micro-extraction (SPME) was prepared using activated carbon powder and silica resin adhesive. The extraction properties of the novel activated carbon coating fiber were investigated. The results indicate that this coating fiber has high concentration ability, with enrichment factors for chloroform, carbon tetrachloride, trichloroethylene and tetrachloroethylene in the range of 13.8 to 18.7. The fiber is stable at temperature as high as 290 degrees C and it can be used for over 140 times at 250 degrees C. The activated carbon coating fiber was then applied to the analysis of the four halocarbon compounds mentioned above. A linear correlation with correlation coefficients between 0.995 2 and 0.999 4 and the detection limits between 0.008 and 0.05 microg/L were observed. The method was also applied to a real water sample analysis and the recoveries of these halocarbon compounds were from 95.5% to 104.6%.

Carbon Tetrachloride↗

PubMed2004

[Environmental physiological characteristics of some mosses in Shanghai: a preliminary study].

The preliminary study on the environmental physiological characteristics of bryophytes collected from Shanghai area, including their responses to drought, temperature, humidity, light and growth substrate, as well as their tissue culture technology showed that different species of bryophytes under same conditions and the same species under different conditions had different drought resistance. Adding organic matter to sand soil and short-illumination benefited the growth of bryophytes. Treating with proper growth hormones could accelerate the reproduction and growth of bryophyte. Hogland medium was suitable for the tissue culture of bryophytes.

Bryophyta↗

PubMed2004

[Effect of Eucalyptus globulus oil on lipopolysaccharide-induced chronic bronchitis and mucin hypersecretion in rats].

OBJECTIVE: To study the effect of Eucalyptus globulus oil on bronchiolitis and mucin hypersecretion in chronic bronchitis induced by lipopolysaccharide in rats. METHOD: Rat model was established by intratracheal instillation of lipopolysaccharide 0.2 mg. Pathological changes, alteration in bronchoalveolar lavage fluid (BALF) and immunohistochemistry characters were examined after 3 weeks and the effect of E. globulus oil was observed. RESULT: Characters of pathological manifestations of chronic bronchitis were found after instillation of LPS. Inflammatory cell infiltration and bronchiolitis severity were significantly reduced after administration of E. globulus oil. Especially in 300 mg x kg(-1) treated rats, there were significant decreases of mucin content in BALF and MUC5ac expression in trachea and bronchiole epithelium. Optical density and mucins area% detected by image analysis system were apparently lower than those in model group. CONCLUSION: E. globulus oil has the anti-inflammatory effect on chronic bronchitis induced by lipopolysaccharide in rats and the inhibitio effect on hypersecretion of airway mucins.

Animals↗