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Y Dai

Publications and source records attributed to Y Dai.

At least 19 recordsLinked to original sources
PubMed1992

Gene therapy via primary myoblasts: long-term expression of factor IX protein following transplantation in vivo.

We have explored the use of primary myoblasts as a somatic tissue for gene therapy of acquired and inherited diseases where systemic delivery of a gene product may have therapeutic effects. Mouse primary myoblasts were infected with replication-defective retroviruses expressing canine factor IX cDNA under the control of a mouse muscle creatine kinase enhancer and human cytomegalovirus promoter. The infected myoblasts were injected into the hindlegs of recipient mice and levels of secreted factor IX protein were monitored in the plasma. We report sustained expression of factor IX protein for over 6 months without any apparent adverse effect on the recipient mice.

Animals↗
PubMed1992

Long-term expression of a retrovirally introduced beta-galactosidase gene in rodent cells implanted in vivo using biodegradable polymer meshes.

Grafts of various types of cells have been performed using bioresorbable polymer matrices. These synthetic fibers are degraded by hydrolysis into normal metabolic intermediates and induce a number of events that are conductive to healing and/or repair, the most important of which may be angiogenesis. The use of biodegradable meshes to deliver genetically altered cells was studied. A beta-galactosidase gene was inserted into Long-Evans rat bone marrow stromal (BMS) cells or fibroblasts derived from C57BL/6J mouse embryos using the retroviral vector LNL-SLX beta gal. Expression was monitored using X-gal staining. X-gal+ cells from monolayer cultures were seeded onto either polyglycolic acid (PGA) or polyglactin (PGL) biodegradable meshes and grown to confluence. Two types of grafts were performed: (1) embryonic C57BL/6J mouse fibroblasts (EMF) into either nude mice or adult C57BL/6J mice, and (2) Long-Evans rat BMS into Long-Evans rats. Beta-Galactosidase activity was found for up to 152 days for EMF in nude mice, 123 days for EMF in adult C57BL/6J mice, and 90 days for grafts of syngeneic BMS cells into Long-Evans rats. Noninfected cells grafted using the same methods did not stain with X-gal.

Animals↗
PubMed1992

Circulating human or canine factor IX from retrovirally transduced primary myoblasts and established myoblast cell lines grafted into murine skeletal muscle.

We have used retroviral vectors to introduce human or canine factor IX cDNAs into cultured primary murine and canine myoblasts and into the established murine myoblast cell line C2C12. In all cases, the stably infected cells produced biologically active factor IX in culture and secreted detectable amounts into the culture medium both before and after differentiation of the cells into myotubes. Myoblasts and differentiated myotubes are therefore capable of performing all the posttranslational modifications of the coagulation factor required for biological activity. We have grafted the genetically modified myoblasts into skeletal muscles of nude mice and have detected stable levels of circulating human factor IX for up to two months after grafting. We propose that grafting genetically modified primary myoblasts or established myoblast cell lines into skeletal muscle may represent a useful approach to gene therapy for a variety of genetic diseases, including intrinsic muscle disease and defects in circulating proteins as in the hemophilias.

Animals↗
PubMed1992

Cyclosporin A and FK506 prevent the derepression of the IL-2 gene in mitogen-induced primary T lymphocytes.

In resting primary T lymphocytes the interleukin 2 (IL-2) gene is silenced by a repressor binding to the Pud element spanning positions -292 to -264 upstream of the cap site. Upon T-cell activation, this silencer is displaced by a positive transcription factor (TF) and the gene is derepressed and transcribed. Cyclosporin A (CsA) and FK506 interfere with normal derepression of the IL-2 gene. Both drugs exert no direct effect on basal transcription of the IL-2 or control viral genes. Direct addition does not abolish the active state of positive TFs present in proteins from activated T cells. However, if T cells are activated in the presence of either drug, their proteins not only fail to derepress, but efficiently and irreversibly silence IL-2 transcription. DNA-protein binding data show that proteins present in drug-treated cells form retarded complexes corresponding in size to the silencer and positive TF. Thus, in drug-treated cells a functional silencer persists, and a positive TF-like factor appears which is functionally abnormal. Moreover, drug-treated T cells appear to form a component that prevents functioning of normal positive TF.

Animals↗
PubMed1992

Direct gene transfer to the liver with herpes simplex virus type 1 vectors: transient production of physiologically relevant levels of circulating factor IX.

We have used gene transfer vectors derived from a replication-defective mutant of herpes simplex virus type 1 (HSV-1) expressing the hepatitis B virus surface antigen (HBsAg), Escherichia coli beta-galactosidase (beta-gal), or canine factor IX (cFIX) from the immediate early promoter of human cytomegalovirus (hCMV) to infect mouse liver by direct injection or through the portal vein. By either route, high levels of transgene expression were demonstrated by the detection of immunoreactive HBsAg or cFIX in the circulation and by histochemical detection of beta-gal activity in situ. The results were striking in that the serum level of cFIX reached 10% of the normal murine levels. Although the level of transgene expression from the hCMV promoter was transient, a significant number of persistent vectors could be rescued from the livers of recipient mice up to 2 months after inoculation. Replacement of the hCMV promoter with the HSV-1 latency-associated transcript (LAT) promoter resulted in reduced but prolonged expression of both HBsAg and cFIX. The very high level of factor IX expression suggests that clinically useful gene transfer may eventually be feasible through direct vector delivery to the liver.

Animals↗
PubMed1992

[Inhibition of fructus Corni on experimental inflammation].

Fructus Corni (FC) decoction inhibits the increase of peritoneal capillary permeability by ip 0.7% acetic acid in mice, the proliferation of granuloma formed by implanting cotton pellets in rats, the swelling of mouse pinnea with xylene and the edema of hind paw induced by injection of fresh egg white 0.1 ml in rats. FC decreases the contents of ascorbic acid in adrenal, but has no marked effect on the contents of prostaglandin E in inflammatory tissue of rats. These results indicate that the inhibitory effect of FC on the inflammatory process may be related to pituitary-adrenal axis.

Adrenal Glands↗
PubMed1992

[Preparation of sucking tablet of shengmei] off.

The Sucking Tablet of Shengmei is made from eight Chinese traditional drugs including Radix Adenophorae, Fructus Mume, etc. The effective rate of the tablet in treating chronic pharyngitis reaches up to 96 percent. The working mechanism related to the fact that the tablet is bacteria-resistant and helps to strengthen the body function. This paper presents the preparation process of the Sucking Tablet along with solutions for some problems encountered in the process and appropriate standards for quality control.

Animals↗
PubMed1992

[Effects of artificial cultured Panax notoginseng cell on cardiovascular system].

Alcoholic extract from artificial cultured Panax notoginseng cell (SCC) ip has been found conducive to increasing the resistance of mice to anoxia. In vitro it helps to increase the outflow of coronary vessels, decrease the heart rate, inhibit the constriction of aortic strip stimulated by nor-epinephrine and relax spasmodic constriction of ileum smooth muscles markedly. SCC powder suspension on po administration can contract bleeding and coagulation time. The pharmacologic activities of SCC are similar to those of crude Panax notoginseng.

Animals↗
PubMed1992

[Use of airway stent subsequent to endoscopic Nd-YAG laser treatment in central airway obstruction].

Ten cases of central airway obstruction mainly caused by extrinsic compression due to the growth of extratracheal malignant tumors or longitudinal extension of tracheal adenoid cystic carcinomas, underwent palliative intubation subsequent to endoscopic Nd-YAG laser treatment. Mean length of the severe stenosis in these cases was 4.4 cm (3-7 cm). Sole application of endoscopic Nd-YAG laser to the stenosis failed relief of the symptom and an immediate palliative intubation was recommended. Mean time of the temporary intubation was 7 days (4-11 days). Airway was maintained by this intubation and also retained enough after extubation. Therefore, it seemed that, in a palliative treatment of the central airway severe stenosis, usefulness of the combination management of Nd-YAG laser with following temporary intubation was revealed. However, in order to maintain the airway for recurrence of the obstruction, use of indwelling airway stents seemed a better application. The longest period of follow-up in the cases treated by indwelling airway stents was 6 months and one of the cases is a now in comfortable state.

Adult↗
PubMed1991

The ryanodine receptor/junctional channel complex is regulated by growth factors in a myogenic cell line.

The ryanodine receptor/junctional channel complex (JCC) forms the calcium release channel and foot structures of the sarcoplasmic reticulum. The JCC and the dihydropyridine (DHP) receptor in the transverse tubule are two of the major components involved in excitation-contraction (E-C) coupling in skeletal muscle. The DHP receptor is believed to serve as the voltage sensor in E-C coupling. Both the JCC and DHP receptor, as well as many skeletal muscle-specific contractile protein genes, are expressed in the BC3H1 muscle cell line. In the present study, we find that during differentiation of BC3H1 cells, induced by mitogen withdrawal, induction of the JCC and DHP receptor mRNAs is temporally similar to that of the skeletal muscle contractile protein genes alpha-tropomyosin and alpha-actin. Our data suggest that there is coordinate regulation of both the contractile protein genes (which have been studied in detail previously) and the genes encoding the calcium channels involved in E-C coupling. Induction of both calcium channels is accompanied by profound changes in BC3H1 cell morphology including the development of many components of mature skeletal muscle cells, despite lack of myoblast fusion. Visualized by electron microscopy, the JCC appears as "foot structures" located in the dyad junction between the plasmalemma and the sarcoplasmic reticulum of the BC3H1 cells. Development of foot structures is concomitant with JCC mRNA expression. Expression of the JCC and DHP receptor mRNAs and formation of the foot structures are inhibited specifically by fibroblast growth factor.

Actins↗
PubMed1991

[Histopathologic study on resected hepatocellular carcinoma after transcatheter hepatic arterial chemo-embolization].

21 cases of hepatocellular carcinoma (HCC) were surgically resected about 14 or 21 days after transcatheter hepatic arterial chemo-embolization (TACE) mostly for histopathologic assessment of effectiveness. Results showed that complete necrosis of all the tumor bulk was seen in one case (case no. 8) in this series. Partial necrosis of the tumor mass was demonstrated in 19 cases. In 6 cases, the necrotic area was over 50%. In 8 cases, it was between 25-49% and in 5 cases it was below 25%. This strongly indicates a certain effectiveness of TACE on HCC. However, the presence of viable residual tumor in 20 cases, including one with complete viability of the tumor (case no. 1), also suggested the necessity of surgical resection. The case of complete necrosis was related to the frequency of the catheter arriving at the tumor, to the types of embolizing drug, and to the morphopathologic features of the tumor.

Adult↗
PubMed1991

[Pharmacological studies on the Chinese drug radix Angelicae dahuricae].

Several species of the Chinese drug Angelica dahurica from different habitats have been studied in terms of anti-inflammatory, analgesic and antipyretic actions and acute toxicity. The medical value of these species is reported in this paper as a guideline for their clinic application.

Animals↗
PubMed1991

Induction of cytochrome P450 isozymes in human amnion FL cells and its application to the biological detection of mutagens.

Using AHH, EROD, ECOD and APND as marker enzymes and 3-MC, beta-NF, NE and PB as inducers, inducible cytP450 IA and IIB gene expression was demonstrated in the human amnion FL cell line; these cells possess a broad spectrum of drug-metabolizing enzymes. Maximum induction was observed following co-treatment with 3-MC and NE. Both constitutive and induced AHH were proved to have the characteristics of cytP448-dependent mixed-function oxygenases. Induced cytP450 isozyme activity remained at a high level for 24-36 h after removal of the inducer. The induced FL cells were demonstrated to activate common promutagens/procarcinogens in UDS and ADPRT-mediated decrease of NAD content assay systems. This new design can be used as a simplified mutagen screening system: no supplemental liver microsomal activation system is needed.

Amnion↗
PubMed1991

[Anti-inflammatory activities and effect of rhizoma Alismatis on immune system].

10 and 20 g/kg ig of Rhizoma Alismatis (RA) markedly decrease the clearance rate of charcoal particles in mice, but have no significant effect on the weight of immune organs, or on the content of serum antibody hemolysin and immunoglobulin G and the delayed footpad edema induced by sheep red blood cell. The contact dermatitis of mouse pinnae immunized with dinitrochlorobenzene is inhibited by RA when it is given before challenge. In addition, RA 20g/kg suppresses the swelling of mouse rinnae induced by xylene and the proliferation of granuloma induced by cotton-pellet in rats. However, the content of vitamin C in the adrenal of rats is not clearly affected by RA.

Animals↗
PubMed1990

Selective extraction of outer-membrane proteins from membrane complexes of Pseudomonas maltophila by chloroform-methanol.

An organic phase partitioning method is described for the selective purification of outer-membrane proteins (OMPs) from the total membrane complex of the opportunistic human and sheep pathogen, Pseudomonas maltophila. SDS-PAGE analysis confirmed that OMPs purified by chloroform-methanol treatment of the total membrane complex were not only identical to OMPs extracted from outer-membrane vesicles separated by sucrose gradient density centrifugation, but also possessed little or non-detectable levels of inner-membrane contaminants. Further analysis by enzyme linked immunosorbent assay (ELISA) and immunoblotting established that OMPs extracted by organic phase partitioning with chloroform-methanol retained antigenicity and serological activity indistinguishable from OMPs that were present in outer-membrane vesicles resolved by isopycnic sucrose density centrifugation of sarkosyl-treated membrane complexes.

Animals↗
PubMed1990

Karyophilic properties of Semliki Forest virus nucleocapsid protein.

Semliki Forest virus capsid (C) protein molecules (Mr, 33,000) can be introduced efficiently into the cytoplasm of various target cells by electroporation, liposome, and erythrocyte ghost-mediated delivery (M. Elgizoli, Y. Dai, C. Kempf, H. Koblet, and M.R. Michel, J. Virol. 63:2921-2928, 1989). Here, we show that the transferred C protein molecules partition rapidly from the cytosolic compartment into the nucleus. Transport of the C protein molecules into the nucleus was reversibly arrested by metabolic inhibitors, indicating that the transfer process is energy dependent. Fractionation of isolated nuclei revealed that the delivered C protein preferentially associates with the nucleoli. This finding was confirmed by morphological studies, showing that in an in vitro system containing ATP isolated nuclei rapidly accumulated rhodamine-labeled C protein in their nucleoli. Furthermore, in this assay system, the lectin wheat germ agglutinin prevented transfer of C protein through nuclear pores. These results are in agreement with our observation that nucleoli contain measurable amounts of newly synthesized C protein as early as 5 h after infection of cells with SFV. Thereafter, nucleolar-associated C protein increased progressively during the course of infection.

Adenosine Triphosphate↗