Biomedical subjects

F Fang

Publications and source records attributed to F Fang.

At least 73 records · Page 4Linked to original sources

PubMed2001

Defibrinogenating effect of batroxobin (Defibrase) in rats and inhibition of migration of human vascular smooth muscle cells by the plasma of batroxobin-treated rats in vitro.

The defibrinogenating effect of batroxobin (Defibrase) in male Wistar rats and the inhibitory effects of the plasma of batroxobin-treated rats on the migration of human vascular smooth muscle cells (SMCs) were investigated in vitro. At 1 h after a single intravenous injection of 3.0, 10.0 or 30.0 BU/kg batroxobin (ten rats in each group), the fibrinogen levels in the plasma of the rats decreased to 88.3, 66.2 and 16.5%, respectively, of that in the plasma of control saline-treated rats (261.0+/-26.7 mg/dl). When the plasma from the batroxobin-treated rats was added to Dulbecco's modified Eagle's medium at a concentration of 0.2% for a vascular SMC migration assay and incubated in a modified Boyden's chamber system at 37 degrees C for 24 h, significant inhibitory effects on vascular SMC migration were observed in the 10.0 (P<0.05) and 30.0 BU/kg (P<0.01) batroxobin-treated rats. The plasma of batroxobin-treated rats as well as standard rat fibrinogen induced vascular SMC migration in a fibrinogen content-dependent manner except the plasma of the 30.0 BU/kg batroxobin-treated rats. Moreover, the rat serum (0.1 approximately 5.0%) did not show any activity on vascular SMC migration in the present experimental system. These results indicate that the plasma fibrinogen significantly influences vascular SMC migration, and that the inhibitory effect of the plasma of batroxobin-treated rats on vascular SMC migration is related to the defibrinogenating action of batroxobin in vivo.

Animals↗

PubMed2001

Human catalytic antibodies with glutathione peroxidase activity.

In order to generate catalytic antibodies with glutathione peroxidase (GPx) activity, we prepared GSH-S-DNP butyl ester and GSH-S-DNP benzyl ester as the haptens. Two ScFvs that bound specifically to the haptens were selected from the human phage-displayed antibody library. The two ScFv genes were highly homologous, consisting of 786 bps and belonging to the same VH family-DP25. In the premise of maintaining the amino acid sequence, mutated plasmids were constructed by use of the mutated primers in PCR, and they were over-expressed in E. coli. After the active site serine was converted into selenocysteine with the chemical modifying method, we obtained two human catalytic antibodies with GPx activity of 72.2U/micromol and 28.8U/micromol, respectively. With the aid of computer mimicking, it can be assumed that the antibodies can form dimers and the mutated selenocysteine residue is located in the binding site. Furthermore, the same Ping-Pong mechanism as the natural GPx was observed when the kinetic behavior of the antibody with the higher activity was studied.

Amino Acid Sequence↗

PubMed2001

Remodelling of the actin cytoskeleton is essential for replication of intravacuolar Salmonella.

Maturation and maintenance of the intracellular vacuole in which Salmonella replicates is controlled by virulence proteins including the type III secretion system encoded by Salmonella pathogenicity island 2 (SPI-2). Here, we show that, several hours after bacterial uptake into different host cell types, Salmonella induces the formation of an F-actin meshwork around bacterial vacuoles. This structure is assembled de novo from the cellular G-actin pool in close proximity to the Salmonella vacuolar membrane. We demonstrate that the phenomenon does not require the Inv/Spa type III secretion system or cognate effector proteins, which induce actin polymerization during bacterial invasion, but does require a functional SPI-2 type III secretion system, which plays an important role in intracellular replication and systemic infection in mice. Treatment with actin-depolymerizing agents significantly inhibited intramacrophage replication of wild-type Salmonella typhimurium. Furthermore, after this treatment, wild-type bacteria were released into the host cell cytoplasm, whereas SPI-2 mutant bacteria remained within vacuoles. We conclude that actin assembly plays an important role in the establishment of an intracellular niche that sustains bacterial growth.

Actins↗

PubMed2001

Analysis of the cat eye syndrome critical region in humans and the region of conserved synteny in mice: a search for candidate genes at or near the human chromosome 22 pericentromere.

We have sequenced a 1.1-Mb region of human chromosome 22q containing the dosage-sensitive gene(s) responsible for cat eye syndrome (CES) as well as the 450-kb homologous region on mouse chromosome 6. Fourteen putative genes were identified within or adjacent to the human CES critical region (CESCR), including three known genes (IL-17R, ATP6E, and BID) and nine novel genes, based on EST identity. Two putative genes (CECR3 and CECR9) were identified, in the absence of EST hits, by comparing segments of human and mouse genomic sequence around two solitary amplified exons, thus showing the utility of comparative genomic sequence analysis in identifying transcripts. Of the 14 genes, 10 were confirmed to be present in the mouse genomic sequence in the same order and orientation as in human. Absent from the mouse region of conserved synteny are CECR1, a promising CES candidate gene from the center of the contig, neighboring CECR4, and CECR7 and CECR8, which are located in the gene-poor proximal 400 kb of the contig. This latter proximal region, located approximately 1 Mb from the centromere, shows abundant duplicated gene fragments typical of pericentromeric DNA. The margin of this region also delineates the boundary of conserved synteny between the CESCR and mouse chromosome 6. Because the proximal CESCR appears abundant in duplicated segments and, therefore, is likely to be gene poor, we consider the putative genes identified in the distal CESCR to represent the majority of candidate genes for involvement in CES.

Abnormalities, Multiple↗

PubMed2001

[Atmospheric particulate mercury concentration in Changchun City and its dry deposition flux].

From July 1999 to January 2000, the particulate mercury(Hg(p)) concentration of five function sites and one contrast site were determined. In non-heating time, the particulate mercury concentration in urban atmosphere ranged from 0.022 to 0.398 ng.m-3 with an average of 0.145 ng.m-3 and the contrast site with an average of 0.084 ng.m-3. In heating time, the Hg(p) concentration in urban was in the range of 0.148-1.984 ng.m-3 with an average of 0.461 ng.m-3 and with an average of 0.211 ng.m-3 in the contrast site. The Hg(p) concentration in heating time was two times higher than that of non-heating time. Coal fire and wind-blown soil material were the two important sources of Hg(p). Wind-blown soil material contributed 7.9%-38.5% of the Hg(p) with an average of 24.1% in urban. Use theory model to estimate the dry deposition flux with the results of 43.06 micrograms.(m2.a)-1 in urban and 21.28 micrograms.(m2.a)-1 in the contrast site.

Air Pollutants↗

PubMed2001

[The experimental study of the anti-enterovirus effects of drugs in vitro].

OBJECTIVE: To screen the safe and effective anti-enterovirus drugs for clinical application. METHODS: The cytotoxicity of Ribavirin, Shuanghuanglian and Garlic were evaluated through MTT colorimetry and cell morphology. The antiviral activity of Ribavirin, Shuanghuanglian and Garlic were studied in HEL and Vero cells infected with CBV3 and ECHO11 by observing cytopathic effect (CPE), MTT colorimetry and plaque-reduction assay. The antiviral activity of these three drugs were compared and that of Shuanghuanglian and Garlic were also compared before and after ECHO11 absorbing by plaque-reduction assay. RESULTS: (1) The cytotoxicity of these three drugs were expressed as TC50(50% toxic concentration). TC50 of Ribavirin was 2 mg/ml, of Shuanghuanglian 5 mg/ml, of Garlic 12.5 micrograms/ml. (2) Ribavirin could inhibit CBV3 and ECHO11 at the concentration ranged from 1 mg/ml to 1.5 mg/ml. Shuanghuanglian could inhibit CBV3 and ECHO11 at the concentration of 0.5 mg/ml and the viral inhibiting effect was concentration-dependent. Garlic could inhibit CBV3 and ECHO11 at the concentration ranged from 2.5 micrograms/ml to 7.5 micrograms/ml and 5 micrograms/ml was the most effective. (3) Plaque-reduction assay was used to test the anti-virus (CBV3 and ECHO11) activity of these three drugs: plaque reduction rate of 1.5 mg/ml Ribavirin was 43.2% and 37.2%, of 2.5 mg/ml Shuanghuanglian was 81.1% and 88.4% and of 5 micrograms/ml Garlic was 66.2% and 77.4% respectively. The plaque reduction rate of Ribavirin was lower than the other two drugs (P < 0.05), between these two showed no significant difference (P > 0.05). The anti-ECHO11 activity of Shanghuanglian before ECHO11 adsorbing was higher than after ECHO11 adsorbing (P < 0.05). There was no significant difference between the plaque reduction rates of Garlic before and after ECHO11 adsorbin. CONCLUSION: All of the three drugs have anti-virus activity in vitro while Shuanghuanglian and Garlic are more effective. Among these three drugs, the cytotoxicity of Shuanghuanglian is the most weak and the anti-virus activity is the strongest. The antiviral activity of Shuanghuanglian adding before virus adsorbing was higher, so it seems that Shuanghuanglian can prevent EV infection.

Animals↗

PubMed2001

Confirmation of susceptibility gene loci on chromosome 1 in northern China Han families with type 2 diabetes.

OBJECTIVE: To confirm previous effort to identify type 2 diabetes susceptibility genes in a Northern Chinese population by conducting a new genome scan with both an increased number of type 2 diabetes families and a new set of microsatellite markers within the previously localized regions. METHODS: A genome scan method was applied. After multiplexed PCR, electrophoreses, genescan and genotyping analysis, we obtained size information for all loci, and then a further study was done by both parametric and non-parametric linkage analysis to investigate the P values and Z values of these loci. RESULTS: We surveyed 34 microsatellite markers which distributed within 5 regions along chromosome 1, and a total of 12,000 genotypes were screened. Evidence of linkage with diabetes was identified for 8 of the 34 loci. All P values of the 8 loci were lower than 0.05, and the highest Z value was 2.17. A very interesting finding is that all 5 markers at the p- terminal 1p36.3-1p36.23 region, spanning a long range of 16.9 cM, were identified to have a low P value of less than 0.05, which suggests that this region may contain multiple susceptibility genes. Regions 4 and 5 also confirmed the previous findings, and we narrowed these two regions to a 2.7 cM and 2.5 cM regions, respectively. CONCLUSIONS: We further confirmed the results gained in the previous genome-wide scan using an increased number of NIDDM families and a new set of microsatellite markers lying within the initially localized regions. The fact that all 5 loci at the p- terminal region displayed a low P value of less than 0.05 suggests that more than 1 susceptibility gene may reside in this region.

Chromosomes, Human, Pair 1↗

PubMed2001

[Study on infection of transfusion transmitted virus in serum, breast milk of pregnant women and umbilical venous blood from their newborns].

OBJECTIVE: To study transfusion transmitted virus (TTV) infection in pregnant women and their newborns, and the route of transmission. METHODS: Serum, breast milk from 150 pregnant women and umbilical venous blood from their newborns were collected. TTV DNA was amplified by semi-nested-polymerase chain reaction, and the positive products were sequenced directly. RESULTS: The positive rate of TTV DNA in pregnancy serum was 11.3% (17/150). Among the 17 serum positive cases, TTV DNA was detected in 11 breast milk samples, and none in all the umbilical blood. The homologous of partial nucleotide sequence of TTV DNA between the 3 serum samples and their breast milk were 97.6%-99.2%. Compared the 5 serum positive samples (A1-A5) with N22 segments of Japanese original isolate, the homologous of partial nucleotide and amino acid sequence were 71.5%-92.8%, 71.5%-92.8%, respectively. CONCLUSION: There exists TTV infection in pregnancy serum and breast milk. Transmission by breast feeding may be one of the main pathway causing TTV infection.

Adult↗

PubMed2001

[Analyzing partial nucleotide and amino acid sequences of Chinese TTV isolates].

BACKGROUND: To investigate the prevalence of transfusion transmitted virus (TTV) and its sequence characterization in China. METHODS: TTV DNA was amplified by Semi-Nested-PCR, and the positive products were sequenced directly. RESULTS: The homology of partial nucleotide and amino acid sequences of 7 Chinese TTV isolates were 64.7%-98.4% and 62.7%-96.4% respectively when compared with Japanese isolate. Among 7 Chinese TTV isolates, the homology of partial nucleotide and amino acid sequences were 63.5%-98.4% and 60.2%-96.4% respectively. They differently belong to two genotypes and two subgenotypes. CONCLUSIONS: There exists TTV in China, and there might be several genotypes of Chinese TTV isolates.

Amino Acid Sequence↗

PubMed2001

[Studies on fatty oils in yolk oil processed by different methods].

OBJECTIVE: To investigate the influence of different processing methods on fatty oils in yolk oil. METHOD: The contents of fatty oils and fatty acids were determined by ROESS GOTTILE and GC respectively, and the physicochemical properties of fatty oils were identified by pharmacopoeial method. RESULTS AND CONCLUSION: The yolk oils processed by daking and dry distillation are almost similar in the contents of fatty oils, type of fatty acids, acid value, iodine value, saponification value, relative density and refractive index, while obvious differences were found in the products processed by chloroform extraction.

Egg Yolk↗

PubMed2001

[Clindamycin soluble suppository-production and its efficacy in treating bacterial vaginosis].

OBJECTIVE: To make the soluble suppository of clindamycin which is an effective drug for treatment of Bacterial vaginosis and to treat patients in clinical trials. METHODS: Outpatients who had vaginal infections from Sept. 1998 to Jan. 1999 were investigated. The diagnoses of bacterial vaginosis were made according to Amsel's criteria and 80 patients were included in this study. They were divided into two groups to be treated respectively by metronidanole suppository and clindamycin suppository which were made by our hospital pharmacy. RESULTS: The cure rate of metronidanole was 87.5% and that of clindamycin 90.3%; No significant difference was noted between the two groups(P > 0.05). The new clindamycin suppository was not irritant and it was easy to dissolve in vagina. There was no discontinued treatment because of side-effect. CONCLUSION: The clindamycin suppository does not irritate the mucosa of vagina, it is an efficacious remedy for bacterial vaginosis.

Administration, Intravaginal↗

PubMed2001

[The protective effects of tea catechins on the injury of cerebral ischemia and reperfusion in rats].

OBJECT: The protective effects of tea catechins on the injury of cerebral ischemia and reperfusion in rats were observed with rat cerebral ischemia and reperfusion model produced by bilaterally clamping the common carotid arteries and vagus nerves for 60 min and then removing the occlusion for 30 min. METHOD: Wistar rats were divided into normal control group, model group and catechin group (30 mg.kg-1 and 50 mg.kg-1 i.p., qd x 7 d). The changes of biochemical indications and pathology were observed. RESULT: The results presented that the concentration of MDA in brain tissue and serum of model rats were higher than that of control rats(P < 0.01). Compared with model group, tea catechin groups could decrease the concentration of MDA in brain tissue and serum, and tea catechin group (50 mg.kg-1 i.p., qd x 7 d) could improve the injury of blood brain barrier. CONCLUSION: Tea catechins have protective effects on the injury of cerebral ischemia and reperfusion in rats.

Animals↗

PubMed2000

Establishment of a multiplex PCR system to diagnose tuberculosis and other bacterial infections.

In order to rapidly diagnose and differentiate tuberculosis from other bacterial infections, a 16S rRNA gene (16s rDNA)-directed multiplex PCR system was developed. In this system, a pair of universal primers and a tubercle bacillus (Tb)-specific primer were designed based on highly conserved regions and Tb species-specific variable region of bacterial 16s rDNA. A 360 bp fragment was detected in all bacteria tested, and a 210 bp fragment was found only in Tb. 19 species of known bacteria including Tb were used for evaluating specificity, universality and sensitivity of the PCR. Candida albicans and human diploid cell served as controls. It was found that both 210 bp and 360 bp fragments were amplified only in Tb, and only 360 bp fragment was detected in other 18 species of general bacteria. Candida albicans and human cells were negative for both 360 bp and 210 bp fragments. The lowest detectable level of the PCR was 10 fg of DNA for Escherichia coli and 100 fg of DNA for Tb. The results indicated that this multiplex PCR system for the simultaneous detection of Tb and other common bacteria had higher specificity and sensitivity, as well as good universality and might be useful to rapidly diagnose bacterial infections and effectively distinguish tuberculosis from other bacterial involvement.

Amidohydrolases↗

PubMed2000

The decay of the latent reservoir of replication-competent HIV-1 is inversely correlated with the extent of residual viral replication during prolonged anti-retroviral therapy.

Replication-competent HIV-1 can be isolated from infected patients despite prolonged plasma virus suppression by anti-retroviral treatment. Recent studies have identified resting, memory CD4+ T lymphocytes as a long-lived latent reservoir of HIV-1 (refs. 4,5). Cross-sectional analyses indicate that the reservoir is rather small, between 103 and 107 cells per patient. In individuals whose plasma viremia levels are well suppressed by anti-retroviral therapy, peripheral blood mononuclear cells containing replication-competent HIV-1 were found to decay with a mean half-life of approximately 6 months, close to the decay characteristics of memory lymphocytes in humans and monkeys. In contrast, little decay was found in a less-selective patient population. We undertook this study to address this apparent discrepancy. Using a quantitative micro-culture assay, we demonstrate here that the latent reservoir decays with a mean half-life of 6.3 months in patients who consistently maintain plasma HIV-1 RNA levels of fewer than 50 copies/ml. Slower decay rates occur in individuals who experience intermittent episodes of plasma viremia. Our findings indicate that the persistence of the latent reservoir of HIV-1 despite prolonged treatment is due not only to its slow intrinsic decay characteristics but also to the inability of current drug regimens to completely block HIV-1 replication.

Adult↗

PubMed2000

[Information behavior of microsatellite loci in genome scanning].

OBJECTIVE: To determine the heterozygosity and polymorphism information content of 139 microsatellite loci in Han population. METHODS: Multiplex approach was used to analyze the 139 loci. The amplified fragments were subjected to electrophoresis in PAGE gel and analyzed with Genescan( TM) and Genotyper(TM). RESULTS: The heterozygosities are between 0.35 to 0.89, with the heterozygosities of 88% loci >0.60. PICs are in the range of 0.32 and 0.88, with PICs of 95% loci >0.50. CONCLUSION: The polymorphism information content of microsatellite loci is very high and their distribution varies in different races and populations.

Aged↗

PubMed2000

Isolation of genes related to blood glucose-control in rat skeletal muscle.

OBJECTIVE: To isolate genes related to blood glucose-control using Sprague Dawley (SD) rat skeletal muscle. METHODS: Differential gene expression between glucose stimulated and non-glucose stimulated SD rat skeletal muscle was obtained by the differential display (DD) method, Slot blotting hybridization and Northern blot hybridization. RESULTS: Several new genes that are differentially expressed in glucose stimulated and non-glucose stimulated SD rat skeletal muscle were isolated. 74 were verified by slot analysis from 181 gene tags isolated. Of them, 33 were cloned and sequenced, and homologous analysis and application for GenBank Access Number were carried out. 21 expressed sequence tag (EST) representing novel genes was confirmed by Northern blot analysis. A total of 9 novel genes showed significant differential expression patterns. CONCLUSIONS: Using improvements and modifications of the differential display technique, a labor- and cost-saving route was used to identify new genes related to blood glucose-control. We investigated differentially expressed genes at the whole body level instead of the culture cell level, to ensure experimental results closer to the normal physiological state. This technique may be valid in wide-spread application to other related research.

Animals↗

PubMed2000

[Screening the trans-action factors binding to the enhancer element of rat GST-P by yeast one-hybrid system].

OBJECTIVE: To investigate the diversity of the mechanisms of rat glutathione S-transferase P (GST-P) gene expression regulation and the relation between rat GST-P gene expression and carcinogenesis. To search the trans-action factors binding to the enhancer element of rat GST-P (glutathione S-transferase P enhancer, GPE I). METHODS: We searched the trans-action factors binding to GPE I using yeast one-hybrid system, and analyzed the DNA sequence by sequencing and computer search. RESULTS: Two positive clones pYGPE1 and pYGPE2 were obtained. The homologies of the insert sequence of pYGPE1 nucleotide and amino acid sequences with rat c-jun cDNA were 99% and 100% respectively; the homologies of the insert sequence of pYGPE2 nucleotide and amino acid sequences with rat mitochondrial adenine nucleotide translocase cDNA were 99% and 100% respectively. CONCLUSIONS: Rat c-Jun and mitochondrial adenine nucleotide translocase can bind to the GPE I core sequence, and they perhaps are the trans-action factors of GPE I.

Animals↗

PubMed2000

[Yeast one-hybrid system--one effective method studying DNA-protein interaction].

Yeast one-hybrid system based on the principle of yeast two-hybrid system, is applied for isolating novel genes encoding proteins that bind to a target, cis-acting regulatory element. The system may also be applied to map the DNA-binding domain of previously known, or newly identified DNA-binding proteins. Yeast one-hybrid system offers maximal sensitivity because detection of the DNA-protein interaction occurs while proteins are in their native configurations. In addition, the gene encoding the DNA-binding proteins of interest is immediately available after a library screening. In this mini-review, we introduce the principle, the experimental procedures, the applications, and the merits of yeast one-hybrid system.

DNA↗