Biomedical subjects

Bing Wang

Publications and source records attributed to Bing Wang.

169 records · Page 10Linked to original sources

PubMed2002

[Effects of adenovirus-mediated HSV-tk/GCV system on lens epithelium].

OBJECTIVE: To investigate the efficiency of adenovirus-mediated herpes simplex virus thymidine kinase/ganciclovir (HSV-tk/GCV) suicide gene therapy system on calf lens epithelial cells and analyze the mechanism of cell death. METHODS: Calf lens epithelial cells were infected in vitro by the recombinant adenoviral vector containing HSV-tk gene (suicide gene) and followed by the treatment of GCV. Finally the efficiency was observed. In addition, the E(1) deleted empty adenoviral vector was used as the control. The conditions of cell necrosis and apoptosis were detected by electron microscope and staining with TUNEL and AO-EB (acridine orange-ethidium bromide) methods. RESULTS: Calf lens epithelial cells trans-infected by adenoviral vector containing HSV-tk gene were significantly inhibited in vitro by GCV treatment. And the phenomenon of bystander effect was confirmed. By comparison, there was no obvious toxin on the cells infected by empty adenoviral vector. Under the treatment of various dosages of GCV, a significant difference of the cell survival rate existed between the ADV/HSV-tk group and the ADV/Empty group (t = 4.94, P < 0.01). The killing efficiency of GCV increased with the prolongation of time. And the cell survival rate of the ADV/HSV-tk group was much lower than that of the ADV/Empty group (t = 11.28, P < 0.001). Many lens epithelial cells were found in the group of ADV/HSV-tk. The levels of necrosis (t = 14.72, P < 0.001) and apoptosis (t = 7.28, P < 0.01) of lens epithelial cells in the ADV/HSV-tk group were greatly higher than those in the group of ADV/Empty. CONCLUSIONS: Adenoviral vector may successfully transduct HSV-tk gene (suicide gene) into calf lens epithelial cells. The lens epithelium expressing HSV-tk gene can be effectively killed by GCV. The mechanism of cell death caused by HSV-tk/GCV is probably necrosis and apoptosis. Therefore, adenovirus-mediated HSV-tk/GCV suicide gene therapy system may provide an effective approach to the treatment of posterior capsule opacification (PCO).

Adenoviridae↗

PubMed2002

[Karyotype analysis of Astragalus complanatus chromosome].

Micrograph were used to analyse the number, karyotype and volume of chromosome of Astragalus complanatus. The normal diploid 2n = 16, karyotype formula based on Levean publication (1964) was K(2n) = 16 = 10 m + 6 sm. According to the method of S.R. Guo, the chromosome relative length was 2n = 16 = 6M2 + 10M1, which belonged to "2A" type according to the Stebbins' karyotype classification. The total length of chromosome groups was 33.05 microns, total length of long arms was 19.76 microns, from Arano's method the AS.K% was 59.79%. The total volume of chromosome was 50.6 micron 3.

Astragalus Plant↗

PubMed2002

[Effects of simulated weightlessness on pressure-volume relationships of femoral vein of New Zealand Rabbits].

Objective. To observe the changes of pressure-volume relationships of rabbit femoral veins and their structural changes caused by simulated weightlessness. Method. Head-Down Tilt (HDT) -20 degrees rabbit model was used to simulate weightlessness. Twenty four healthy male New Zealand Rabbits were randomly divided into 21 d HDT group,10 d HDT group and control group, (8 in each group). Pressure-volume (P-V) relationship of rabbits femoral veins was measured and the microstructure of the veins was observed. Result. The femoral vein P-V relationship curves of HDT groups showed a larger volume change ratio than that of control group. This change was that 21 d HDT group was even more obvious than that of HDT-10 d group. B1 and B2 in quadratic equations of 21 d HDT group were significantly higher than the values of both 10 d HDT group and control group during expansion (inflow) and collapse (outflow) (P<0.01). The result of histological examination showed that the contents and structure of femoral vein wall of HDT-rabbits changed significantly. Endothelial cells of femoral vein became short and columnar or cubic, some of which fell off. Smooth muscle layer became thinner. Conclusion. Femoral venous compliance increased after weightlessness-simulation and the femoral venous compliance in 21 d-HDT rabbits increased more obviously than that in 10 d-HDT rabbits. The structure of femoral vein wall had changed obviously.

Adaptation, Physiological↗

PubMed1996

Synthesis of Tungsten Carbonyl and Nitrosyl Complexes of Monodentate and Chelating Aryl-N-sulfonylphosphoramides, the First Members of a New Class of Electron-Withdrawing Phosphine Ligands. Comparative IR and (13)C and (31)P NMR Study of Related Phosphorus Complexes.

Reaction of N,N'-bis(tolylsulfonyl)-1,2-diaminoethane with PhPCl(2) gives in 62% yield the phosphonous diamide 2-phenyl-1,3-bis(p-tolylsulfonyl)-1,3,2-diazaphospholidine (4, "TosL") and with Ph(2)PCl in 43% yield the diphosphinous amide N,N'-bis(diphenylphosphino)-N,N'-bis(p-tolylsulfonyl)-1,2-ethanediamine (5, "diTosL"). Reaction of 4 with (THF)W(CO)(5) gives (TosL)W(CO)(5) (6) in 77% yield, and reaction of 5 with trans-BrW(CO)(4)NO gives cis, cis, trans-(diTosL)W(CO)(2)(NO)Br (8) in 86% yield. The IR, (13)C NMR, and (31)P NMR spectra of 4, 5, 6, and 8 are compared to those of a variety of compounds including LW(CO)(5) (L = PMe(3), PPh(3), PPh(NEt(2))(2), P(OMe)(3), P(CF(3))(3)), L(2)W(CO)(2)(NO)Br (L(2) = Ar(2)PCH(2)CH(2)PAr(2) (Ar = Ph (diphos), C(6)F(5) (diphos-F(20))), (CH(3)CN)(2)), and the free ligands as appropriate. The IR data are interpreted to suggest a relative ordering of ligand acceptor ability of P(CF(3))(3) > 4 approximately P(OMe)(3) > PPh(3) approximately PPh(NEt(2))(2) and a relative ordering of ligand donor ability of PPh(NEt(2))(2) >/= P(OMe)(3) > PPh(3) > 4 > P(CF(3))(3). The chelating ligand diTosL is about as electron-withdrawing as diphos-F(20), on the basis of the IR data. The (31)P NMR data qualitatively support the conclusion that TosL and diTosL are highly electron-withdrawing ligands, on the basis of (1)J(PW). The (13)C data do not permit any such generalizations, although the spectra of the diphosphine ligands and adducts are of interest due to the observation of "virtual coupling" that surprisingly can be simulated only as ABX rather than AA'X spin-systems.

Journal Article↗

PubMed1996

Cloning of a Tumor Antigen-related Gene in Small Cell Lung Carcinoma.

The Small Cell lung Carcinoma cell line NCI-H128 cDNA library constructed in Lambda gtll was screened by tumor associated antigen specific monoclonal antibody 2F7. The No.4 positive clone was further investigated. The lysogen of the No.4 clone could be induced at 42 degrees to produce 165 kD fusion protein by IPTG. This fusion protein can be detected by both the monoclonal antibody 2F7 and the anti-beta-galactosidase monoclonal antibody. Antigen Competitive Assay showed that the fusion protein purified by PAGE could compete with the natural tumor associated antigen on the membrane and combine with the monoclonal antibody 2F7. PCR reaction showed the inserted DNA fragment of No.4 Clone to be about 1.3 kb. The DNA inserted fragment was sub-cloned into the plasmid vector Bluescript-sk. Northern blot showed that it was specific for H128 cell line. These results showed that the gene of the tumor associated antigen which specifically reacted with the monoclonal antibody 2F7 was cloned.

Journal Article↗

PubMedDate not supplied

Molecular characterization of pig ST8Sia IV--a critical gene for the formation of neural cell adhesion molecule and its response to sialic acid supplement in piglets.

ST8Sia IV (polysialyltransferase IV gene) encodes a key enzyme that is required for polysialic acid synthesis. Polysialic acid is a component of the neural cell adhesion molecule and is necessary for synaptic plasticity of neural cells. We characterized 5.3 kb of pig ST8Sia IV cDNA and determined its expression profile in different organs. In hippocampus, ST8Sia IV mRNA levels were increased approximately 4.5-fold in piglets with sialic acid as a milk supplement, which suggested that exogenous sialic acid is a conditionally essential nutrient for early brain development. Extensive analyses were also performed among its orthologs from human, mouse, rat, chicken, frog and zebrafish. Our results supported that the piglet is a better animal model than other nonprimate species in the studies of ST8Sia IV related metabolism and nutrition in human infants. This pig cDNA provides a basis for uncovering the roles of ST8Sia IV during piglet development and maturation.

Amino Acid Sequence↗

PubMedDate not supplied

Parenchymal abnormalities associated with cerebral venous sinus thrombosis: assessment with diffusion-weighted MR imaging.

BACKGROUND AND PURPOSE: The common entity cerebral venous sinus thrombosis is associated with the poorly characterized imaging finding of parenchymal abnormalities; diffusion-weighted imaging has offered some insight into these manifestations. We assessed the relationship between the diffusion constant from apparent diffusion coefficient (ADC) maps in patients with cerebral venous thrombosis (CVT) with follow-up imaging findings and clinical outcome. METHODS: We evaluated the medical records and T2-weighted MR images of 13 patients with CVT complicated by intraparenchymal abnormality. Diffusion-weighted (DW) images and ADC maps were evaluated for increased, decreased, or unchanged signal intensity and were compared with signal intensity of contralateral, normal-appearing brain. In addition, ADCs were obtained in nine pixel regions of interest in abnormal regions in eight of the 13 patients. RESULTS: Eight patients had superficial CVT, and five had superficial and deep CVT. CVT of deep veins was associated with deep gray nucleus and deep white matter abnormalities, whereas superficial CVT was associated with cortical and subcortical abnormalities. Twenty-four nonhemorrhagic lesions were identified in 10 of 13 patients on the basis of follow-up imaging findings. Four patients without seizures had lesions with decreased diffusion that appeared hyperintense on follow-up T2-weighted images, three patients with seizures had lesions with decreased diffusion that resolved, and seven patients had lesions with increased diffusion that resolved. Three of 10 patients had more than one lesion type. No difference was noted in mean ADCs for lesions with decreased diffusion that resolved compared with lesions with decreased diffusion that persisted. CONCLUSION: DW imaging in these patients disclosed three lesion types: lesions with elevated diffusion that resolved, consistent with vasogenic edema; lesions with low diffusion that persisted, consistent with cytotoxic edema in patients without seizure activity; and lesions with low diffusion that resolved in patients with seizure activity. This information may be important in prospectively determining severity of irreversible injury and in patient treatment.

Adolescent↗