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Biomedical subjects

F Wang

Publications and source records attributed to F Wang.

At least 217 records · Page 12Linked to original sources
PubMed2000

[Polymorphism of human alleles associated with genetic resistance against HIV-1 infection and its implications].

To investigate the genetic susceptibility of different ethnic populations to human immunodeficiency virus-1(HIV-1) infection by comparing the characteristics of gene mutation frequency and polymorphism of CCR5, CCR2 and SDF-1 alleles among different nationalities in the world. The recently reported data on AIDS progression in patients, and on gene mutation and polymorphism of CCR5, CCR2b and SDF-1 genes were collected. The data also included the HIV-1-associated genes polymorphisms of the Chinese individuals detected by the present authors. There was a significant link between the gene mutation, polymorphism of HIV-1-associated genes, genetic susceptibilities and the AIDS progression in patients, although the differences of HIV-1-associated gene mutation, polymorphisms existed among different ethnic populations in the world. The Chinese individuals are more likely to be infected by the M-tropic HIV-1 strain than the American Caucasian. The Chinese individuals have very low gene mutation of CCR5Delta32, which would be helpful for the prevention and gene therapy against the HIV-1 infection.

Acquired Immunodeficiency Syndrome↗
PubMed2000

[Effects of gene copy number and chromosomal position on the expression of a modified HBsAg gene SA-28 in yeast].

The effect of gene copy number and chromosomal position on heterologous gene expression in Saccharomyces cerevisae has been tentatively investigated using a modified hepatitis B virus surface antigen SA-28 gene. The plasmids containing different copies of SA-28 gene expression cassette were integrated into different chromosomal loci via FLP recombinase mediated targeted integration. The expression of SA-28 gene in the resultant transformants was then measured. The result indicated that the expression of SA-28 gene was positively related to the gene dosage at HIS3 locus and had chromosomal polarity at several chromosomal loci.

Chromosome Mapping↗
PubMed2000

[Production of u-PA with rCHO cell culture on porous microcarriers in serum-free growth medium].

A novel technique was developed to deal with apoptosis in large-scale animal cell culture. By means of replacing part of Cytopore porous microcarriers at regular intervals, a rCHO cell line, which produces urokinase-type plasminogen activitor(u-PA), was cultivated continuously with serum-free medium in a 30 L stirred tank for 91 days. The cell density was maintained at (1.3-2.6) x 10(7)/mL, and > 90% of cells was viable. In order to reduce the effect of cell density on cell growth and expression, a cyclic pressure oscillation was exerted on a 7.5 L reactor headspace to enhance cell expression at high cell density to a certain extent. During the 67 days of medium-replacement culture, the maximal cell density reached 2.64 x 10(7)/mL, and cell viability was always kept above 95% when combined with microcarrier-replacement. Compare to control culture, culture with cyclic pressure oscillation could enhance cell expression level and reduce the ratio of glucose metabolized anaerobically to produce lactate. With four-step purification process, about 80 g u-PA(approximately 90% scu-PA) was recovered from approximately 2100 liters supernatant which contained approximately 135 g u-PA.

Animals↗
PubMed2000

[Fusion expression of cecropin X including the cleavage of FXa in Escherichia coli].

PCR method was used to introduce the code sequence of Factor Xa cleavage site to the 5' end of cecropin CMIV mutant gene X, then the gene was cloned into the expression vector pGEX-KG, and was highly expressed in E. coli BL21 by IPTG induction. The fusion protein was purified by affinity-chromatography and was cleaved by Factor Xa. Cecropin X with antibacterial activity was obtained after purified by ion-exchange chromatography.

Antimicrobial Cationic Peptides↗
PubMed2000

[Bacterial resistance in streptococcus pneumoniae].

OBJECTIVE: To investigate the prevalence of Streptococcus pneumoniae in patients with respiratory tract infection and healthy children and to determine the antibiotic susceptibility in S. pneumoniae. METHODS: Sputum and throat swabs were collected from the adult and children patients. Nasopharyngeal specimens were collected from healthy children with aseptic swab and cultured for S. pneumoniae. Antibiotic susceptibility was determined by agar dilution method. RESULTS: The isolation rates of S. pneumoniae were 10% in both children and adult out-patients, being 30.2% in 2-6 year-old healthy children. Among 82 clinical isolates, only one was low-level resistant to penicillin (MIC 0.125 mg/L). In 228 S. pneumoniae strains from healthy children, 32 were low-level resistant to penicillin (MIC 0.125-0.5 mg/L), the resistant rate being 14.0%. S. pneumoniae was usually resistant to erythromycin, clindamycin and SMZ-TMP. CONCLUSION: The penicillin-resistant strains are far more resistant to all the agents tested than susceptible strains except fluoroquinolones and vancomycin; in addition, several strains resistant to the third generation cephalosporins are found.

Adult↗
PubMed2000

[Effect of combined treatment of 60Co gamma-ray and EMS on antioxidase activity and ODAP content in Lathyrus sativus].

Lathyrus sativus seeds were treated with 60Co gamma-ray and EMS(ethyl methane sulfonate), and their emergence rate and SOD, POD and CAT activities were determined. The result indicated that the treatment decreased the emergence rate. The activities of SOD and POD were changed in accordance with the increase of irradiation dose and EMS concentration, while that of CAT had no obvious change. After treatment, the ODAP content in Lathyrus sativus decreased. Amutant was developed, with toxin content of 0.1%, compared to 0.2% in control.

Amino Acids, Diamino↗
PubMed2000

[Simulation of potential responses of clear-cut of mixed coniferous and broadleaved Korean pine forest in Yichun to climate change by BKPF model].

The potential responses of forest succession in the clear-cut site of mixed coniferous and broad-leaved Korean pine forest (MCBLKPF) in Yichun, Heilongjiang Province to global climate change and elevated CO2 after 50 years by BKPF model were simulated. The results indicated that the densities of Pinus koraiensis and hardwood species(Fraxinus mandshurica, Tilia amurensis, Juglans mandshurica and Phellodendron amurense) would increase, while the densities of Larix olgensis, Betula platyphylla and Populus davidiana would decrease after 50 years. The stand densities would be slightly lower than those at the same age under the current climate condition. The stand productivity, total aboveground biomass and leaf area index will increase by 7-28%, 15-24% and 5-8%, respectively. Climate change would be beneficial to the forest succession from the clear-cut site to MCBLKPF.

Climate↗
PubMed2000

[Effect of temperature and body weight on carbon budget of Penaeus chinensis].

The carbon budget of Penaeus chinensis feeding on polychaet worm(Neanthes japonica) was determined at various levels of temperature (20 degrees C, 25 degrees C, 30 degrees C) and body weights(0.271 +/- 0.041 g, 3.509 +/- 0.301 g, 11.062 +/- 1.027 g) from May to September, 1996. The results show that the carbon consumption was significantly affected by water temperature and body weight, which significantly increased with increasing temperature and decreasing body weight. The average carbon consumptions at 20 degrees C, 25 degrees C and 30 degrees C were 12.41, 19.12 and 26.08 mg.g-1.d-1, and those for 3 body weights were 36.06, 12.17 and 9.38 mg.g-1.d-1, respectively. The intake carbon allocation was not significantly affected by body weight, but significantly affected by water temperature. The proportions of carbon allocated to growth, fecal, exuviation and metabolism at three different temperatures were 31.23%, 4.28%, 7.94%, 56.45%; 26.83%, 2.92%, 6.69%, 65.79%; 16.86%, 2.38%, 5.99%, 74.76%, respectively.

Animals↗
PubMed2000

Polymorphisms of TAP, LMP and HLA-DM genes in the Chinese.

OBJECTIVE: To investigate the distribution of antigen-processing genes transporter associated with antigen processing (TAP), low molecular weight proteasome (LMP2) and HLA-DM in the Shanghai population and to explore the possible role of these genes in the genetic susceptibility to autoimmune diseases IgA nephropathy(IgAN) and multiple sclerosis(MS). METHODS: Eighty normal Shanghai Chinese, 60 patients with IgAN and 21 patients with MS were randomly selected and genotyped for antigen-processing genes (TAP1, TAP2, LMP2, HLA-DMA and -DMB) using polymerase chain reaction-sequence specific oligonucleotide (PCR-SSO) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Two-locus linkage disequilibrium analysis was performed. RESULTS: Four TAP1, 6 TAP2, 2 LMP2, 3 DMA and 4 DMB alleles were observed. Statistically significant associations were found between TAP1B-TAP2A, TAP1B-LMP2H and TAP2D-HLA-DMA* 0101 (Pc < 0.01). There was no association between antigen-processing genes and either IgAN or MS. CONCLUSION: The polymorphisms of antigen-processing genes in this Shanghai population are similar to those observed in the other ethnic populations. No association was found between IgAN or MS and any antigen-processing genes tested in Shanghai population.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

[Synthesis of chimeric anti-MDR1 ribozymes (tRNA-Rzs) and their biological activities in cell-free system].

OBJECTIVE: Development of multidrug resistance(MDR) is the major obstacle to successful cancer chemotherapy. One strategy to block the P-glycoprotein(P-gp)-mediated MDR is to use a ribozyme (Rz) target against MDR1 mRNA. METHODS: Three kinds of anti-MDR1 chimeric hammerhead ribozymes, the first-one cleaving codon 196 of MDR1 mRNA (196MDR1-Rz), the second one, a stem-II base modified (U9-->G9, U13-->A13, G14-->A14, A18-->C18) Rz against codon 196 (196MDR1-sRz) and the third one, the stem-II base modified Rz directed against the -6(-)-4 GUC sequence of the translation initiation site of the MDR1 mRNA (iMDR1-sRz), were synthesized based on the cloned retroviral constructs: N2A + tRNAi(met)-196MDR1-Rz, N2A + tRNAi(met)-196MDR1-sRz, N2A + tRNAi(met)-iMDR1-sRz. RESULTS: In a cell-free system, the chimeric tRNA-sRz molecules were more stable and had more efficient catalytic activities than the corresponding naked Rz molecules. The stem-II base modified Rz molecules were also more stable and efficient in catalytic activities than the unmodified ones. In control, the disabled tRNA-mut-iMDR1-sRz had no cleavage activity. CONCLUSION: Base modification in the Rz's stem-II of ribozyme structure and the development of chimeric tRNA-ribozyme molecules are able to enhance the cleavage efficacy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

[Experimental study of partial liquid ventilation in rabbits with acute lung injury].

OBJECTIVE: To observe the effectiveness of partial liquid ventilation (PLV) on gas exchange, pulmonary compliance (Cst), blood dynamics in the oleic acid (OA) induced acute lung injury (ALI) rabbits. METHODS: 24 healthy male New Zealand rabbits were randomly allocated to three groups and treated with various methods after OA acute lung injury model established. The study groups as follows: PEEP group with conventional mechanical ventilation (CMV) and PEEP, normal saline (NS) group with CMV, PEEP and NS, FDC group with CMV, PEEP and FDC. The parameters such as blood gases, Cst, circulation state were observed before and after treatment. RESULTS: In FDC group, PaO2 increased from (90 +/- 6) mm Hg to (232 +/- 26) mm Hg(P < 0.05), PaCO2 decreased from (52.1 +/- 2.8) mm Hg to (40.1 +/- 3.0) mm Hg (P < 0.05), Cst increased from (1.05 +/- 0.11) ml/cm H2O to (1.79 +/- 0.24) ml/cm H2O(P < 0.05). HR, MAP and CVP showed no significant changes after treatment compared with pretreatment values in FDC group. CONCLUSION: Pulmonary gas exchange and pulmonary compliance improved significantly during PLV in the ALI rabbits, without obvious influence on hemodynamic status.

Animals↗
PubMed2000

[The role of nitric oxide in the pathogenesis of portal hypertension].

OBJECTIVE: To investigate the role of nitric oxide in the pathogenesis of portal hypertension. METHODS: We measured the portal venous pressure of 75 patients via a catheter and detected the levels of plasma endotoxin and NO(2)(-)/NO(3)(-). RESULTS: The mean levels of plasma endotoxin and NO(2)(-)/NO(3)(-) (0.249 +/- 0.112 Eu/ml and 55.9 +/- 26.2 micromol/L) in portal hypertensive patients were significantly higher than those in the controls, and the highest values were observed in the portal venous blood. The mean portal venous pressure of the portal hypertensive patients was 35.5 +/- 4.4 cm H(2)O and was positively correlated with the levels of NO(2)(-)/NO(3)(-) (n = 25, r = 0.55, P < 0.01). Positive correlation existed between them during the postoperative period (r = 0.57, P < 0.05). There was a negative correlation between the levels of albumin and NO(2)(-)/NO(3)(-) (n = 75, r = -0.35, P < 0.01), and the mean levels of NO(2)(-)/NO(3)(-) were 72.4 +/- 20.3 micromol/L in the patients with ascites, much higher than those (50.3 +/- 21.0 micromol/L) without ascites. CONCLUSIONS: The levels of plasma endotoxin and nitric oxide were elevated in patients with portal hypertension, and NO might play an important role in the abnormal elevation of portal venous pressure and the damage to liver function.

Endotoxins↗
PubMed2000

[Measurement of gastric emptying with Xianshizi in patients with resected esophageal cancer].

OBJECTIVE: To determine gastric emptying radiological in patients with esophageal cancer and to obtain a similar effect produced by radionuclide study. METHODS: A new product-Xianshizi (XSZ) made of the mixture of barium and silica gel was used quantitatively to evaluate gastric emptying. 17 patients with resected esophageal cancer before and after operation, and 7 healthy volunteers were studied. RESULTS: Preoperative patients had obviously delayed gastric emptying compared with the control group (P < 0.01). Postoperative patients had more delayed gastric emptying compared with themselves (P < 0.05). CONCLUSIONS: Postoperative gastroparesis is related to delayed gastric emptying. The results of this study were identical with those obtained by scintigraphy. Compared with isotope studies, X-ray exam after taking meal composed of XSZ may eventually contribute to detecting delayed gastric emptying quantitatively.

Adult↗
PubMed2000

[A study on the effect of vitreous cavity length in primary ametropia].

OBJECTIVE: To study the nature of primary ametropia and disclose the actions of ocular refractive components, especially the length of vitreous cavity, on primary ametropia. METHODS: The refractive state, corneal refractive power (CP), anterior ocular segment length (ASL), vitreous length (VL) and ocular axial length (AL) were measured for 1 336 eyes, including 523 hyperopic eyes, 199 emmetropic eyes and 614 myopic eyes. The relationships of these elements were studied. RESULTS: CP had no effect on the refractive state. There was no significant difference between CP of these three refractive groups (hyperopia vs. emmetropia and emmetropia vs. myopia) (P > 0.05). The test of normality showed that the distribution of CP was normal in each refractive state. Case control study of paired sample revealed that ASL did not change regularly with the change of refraction, while VL changed progressively with the change of refraction and there was significant difference between each pair of groups (F = 204.29, P < 0.01). The study of the relationship with matching t test between AL and VL showed that the change amount of AL and VL was nearly the same, that was, the growth of AL was about the same as the growth of VL (P > 0.05). Analysis of correlation and regression showed that these two elements were highly correlated, the coefficient of correlation being 0.879. CONCLUSION: VL determines AL and finally determines refractive state. VL is the most important element in determining primary ametropia while the anterior eye segment has no significant contribution.

Adolescent↗
PubMed2000

[Electron-immunostaining characteristics of platelet-derived growth factor, transforming growth factor beta1 and their receptors in epiretinal membranes].

OBJECTIVE: To investigate the ultrastructural distribution of platelet-derived growth factor (PDGF), transforming growth factor beta(1) (TGF-beta(1)) and their receptors in epiretinal membranes (ERM) and discuss the clinical significance of the distribution. METHODS: 25 membrane specimens were surgically removed by vitrectomy from 9 patients with rhegmatogenous retinal detachment. Double-staining techniques of immunoelectromicroscopy for eight antibodies (PDGF, TGF-beta(1), PDGF receptor subunits alpha and beta, TGF-beta subunits I and II, type I and III collagen) were used in these specimens as previously designed. RESULTS: PDGF and TGF-beta(1) staining appeared to be stronger on early (< 2 months) and late (> 6 months) stage membranes than that of middle (2 - 6 months) stage of membranes, and the immunostaining intensity inverted with the degree of proliferative vitreoretinopathy (PVR). We found that the gold particles of PDGF and TGF-beta(1) tended to get together with that of type I and III collagen. In addition, the stainings of four growth factor receptors were frequently positive in a type of epithelial-like cells with rich cytoplasm components, and also the gold particles of PDGF and TGF-beta(1) were found around these cells. CONCLUSIONS: A concentration change of PDGF and TGF-beta(1) exists in development of ERM throughout. The epithelial-like cells are of a type of active cells, and autocrine and paracrine activity may be involved in ERM pathogenesis. PDGF and TGF-beta(1) influence the contractile activity of ERM.

Epiretinal Membrane↗
PubMed2000

[Study on the epidemiological features of Kawasaki disease in Jiangsu].

OBJECTIVE: To investigate the incidence of Kawasaki disease and epidemiological characteristics in Jiangsu province. METHODS: Questionnaire and diagnostic guidelines for Kawasaki disease with color - printed photographs of typical clinical symptoms were sent to all county hospitals with pediatric beds. All the in - patients with Kawasaki disease hospitalized from January, 1993 to December, 1997 were studied regarding age, sex, season of illness, cardiac sequelae, outcome etc. RESULTS: There were 509 cases (329 males and 180 females) diagnosed with 489 cases (96%) clinically typical. The incidence of the 5 - year period was averaged 2.53 per 100,000 children under 5. The number of male patients with Kawasaki disease was higher than that in female. The age peak of incidence was between 6 month and 2 - year olds. 13.6% of all cases developed cardiac sequelae which mostly occurred in males and in those younger than 2 years of age. There was one patient recurred among total patients reported (recurrence rate 0.2%) and 2 patients died (fatality rate 0.4%). CONCLUSION: The epidemiological characteristics of Kawasaki disease in Jiangsu province were similar to those in Japan in sex, season distribution and cardiac sequelae. The number of patients in male was higher than in female. Patients were more commonly seen in spring than in winter. However, the incidence rate in Jiangsu was significantly lower than that in Japan and the age peak was between 6 month and 2 years old.

Adolescent↗