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C J Liu

Publications and source records attributed to C J Liu.

At least 73 records · Page 4Linked to original sources
PubMed1996

A newly developed solution enhances thirty-hour preservation in a canine lung transplantation model.

Ischemia and reperfusion cause the production of oxygen free radicals. These damage grafts or disrupt normal vascular homeostatic mechanisms, with a parallel reduction in endothelial nitric oxide and adenosine 3',5'-cyclic monophosphate levels. We hypothesized that lung preservation failure may be related to these events. To improve lung preservation, we prepared a new ET-Kyoto solution, which contains N-acetylcysteine (a radical scavenger), nitroglycerin (to elevate the nitric oxide level), and dibutyryl adenosine 3',5'-cyclic monophosphate (to elevate the adenosine 3',5'-cyclic monophosphate level) and examined its efficacy in a canine single-lung transplantation model. Lungs were flushed with new ET-Kyoto solution (group I, n = 9), basal ET-Kyoto solution (group II, n = 6), basal ET-Kyoto solution plus ethanol and propylene glycol (solvents of nitroglycerin; group III, n = 6), or low-potassium dextran glucose solution (group IV, n = 6), and stored at 4 degrees C for 30 hours. After left single-lung transplantation, the right main bronchus and right pulmonary artery were ligated and the functions of the transplanted lung were assessed for 6 hours. Arterial oxygen tension was significantly higher in group I than in groups II, III, and IV (p < 0.05). Peak inspiratory pressure and wet-to-dry lung weight ratio were significantly lower in group I than in groups II and IV (p < 0.01). Histologic and ultrastructural studies showed better preservation in group I than in groups II, III, and IV. We conclude that the new ET-Kyoto solution provides enhanced 30-hour lung preservation.

Animals↗
PubMed1996

Retinal Thy-1 expression during development.

PURPOSE: To evaluate the developmental expression of Thy-1 in the retina. Thy-1, the most abundant mammalian neuronal surface glycoprotein, is likely to play a significant role in retinal development. In the mammalian retina, it is found predominantly, if not exclusively, on retinal ganglion cells. METHODS: Rat retinae of various ages were stained immunohistochemically for Thy-1 with 2G12, a monoclonal Thy-1 antibody. Sections were analyzed digitally to quantify bound antibody. Using semiquantitative reverse transcription-polymerase chain reaction (RT-PCR), the expression of Thy-1 protein was compared with the levels of mRNA detected. RESULTS: Thy-1-dependent fluorescence was detected in rat retinae from birth, albeit at low levels. Thy-1 labeling was localized predominantly to the ganglion cell layer. Minimal, fine patterns of linear and reticular fluorescence were noted in the inner nuclear layer. Thy-1 levels reached a maximal level at approximately postnatal day 14. RT-PCR measurements showed a similar time course for the increase in Thy-1 expression. CONCLUSIONS: The Thy-1 antigen is present in the inner retina at birth. Its level increases steadily after birth and peaks during the second week of life. Thy-1 expression is approximately coterminous with synaptogenesis of the inner plexiform layer and may play a role in synaptogenesis of the inner retina or in other developmental milestones in the formation of the visual system.

Animals↗
PubMed1996

[Cloning and identification of recombinant cDNA to a rabbit oviductin "DPF-1"].

A recombinant cDNA library to polyA + RNA isolated from rabbit oviduct epithelial cells was constructed, and screened with a polyclonal antibody against DPF-1 (64 kDa). 4 immunopositive plaques (DPF-1.1, DPF-1.2, DPF-1.3 and DPF-1.4) were purified. The polyclonal antibodies were epitope-selected respectively against the fused proteins produced by these positive recombinant plaques. Identification of recombinant clones by epitope selection revealed that the epitope-selected antibodies from DPF-1.1, DPF-1.2 and DPF-1.3 could recognise not only DPF-1, but 44 kDa protein also (Fig. 2). By using EcoRI-Not1 digestion method, the insert cDNA fragment size of these three recombinants was revealed to be 0.8 kb, 1.2 kb and 1.2 kb respectively (Fig. 3). These cDNA fragments were then isolated and subcloned into pBluescriptKS, and recombinant plasmids (pDPF-1.1, pDPF-1.2 and pDPF-1.3) were constructed (Fig. 4). Dot blot hybridization with a 32p-labeled 1.2 Kb-insert of cDNA from pDPF-1.3 indicated that these recombinant plasmids could cross-hybridized (Fig. 5), further indicating that they all possessed a common nucleic acid sequence. Dot and Northern blotting analysis of total RNA prepared from eight different tissues (skeleton muscle, heart, kidney, oviduct, liver, spleen, lung and small intestine) showed that the gene encoding DPF-1 was expressed specifically in the oviduct tissue (Fig. 6, Fig. 7).

Animals↗
PubMed1996

[Preliminary studies on the rabbit oviductin "DPF-1"].

Anti-rabbit 64 kDa oviductin (named Development Promoting Factor-1, DPF-1) antibody could inhibit totally the early development of mouse fertilised eggs cultured in the conditioned medium derived from the rabbit oviduct mucosa epithelial cells, revealed that DPF-1 synthesized and secreted from rabbit oviduct mucosa has a function to overcome the developmental block of early mouse embryos. It seems that DPF-1 consists of a group of polypeptide isoforms, since its isoelectric points are ranging from 7.2 to 8.1 (Fig. 3). The synthesis and secretion of DPF-1 was not dependent on either 17 beta-estradiol or progesterone (Fig. 7), it can pass through zona pellucida easily and associate tightly with the early embryonic cell membrane (Fig. 6). By using Western blotting method, we found that DPF-1 was not appeared in the tissues of liver, heart, lung, spleen, uterus, ovary, small intestine, skeleton muscle and brain, but in that of oviduct (Fig. 4): some DPF-1 homologous molecules were also revealed in the oviduct tissues of mouse and golden hamster, their apparent molecular weights were 32 kDa, 72 kDa in mouse, and 49 kDa, 68 kDa in golden hamster (Fig. 5). Results obtained from the in vivo anti-fertility experiment, namely to analyse the anti-fertility effect in adult female mice after active immunization with DPF-1, showed that the fertility decreased significantly as compared to those of controls (p < 0.01) (Table 1). DPF-1 and its in vivo "loss of function" evidence we obtained will encourage us to study the mechanism of DPF-1 in overcoming the developmental block of early embryos, and its role in transition from maternal to embryonic control of early development.

Animals↗
PubMed1995

Molecular characterization of the in vivo alkylating agent resistant murine EMT-6 mammary carcinoma tumors.

The expression of several early-response genes and genes associated with malignant disease was assessed in the EMT-6/parent tumor and the EMT-6/CTX and EMT-6/CDDP in vivo resistant tumor lines growing as tumors or as monolayers in culture. In the absence of treatment the levels of mRNA for the genes c-jun, c-fos, c-myc, Ha-ras and p53 were increased in the EMT-6/CTX and EMT-6/CDDP as compared with the EMT-6/parent tumor, whereas the expression of erb-2 was similar in all three tumors. Although the cells from each of the three tumors show increased expression of early response genes after exposure to cisplatin (CDDP; 100 microM, 2 h) or 4-Hydroxyperoxycyclophosphamide (4-HC; 100 microM, 2 h) in culture, in mRNA extracted from tumor tissue these changes are absent or very small. Both C-jun and erb-2 were detectable in liver. There was increased expression of both of these genes in the livers of tumor-bearing animals as compared with non-tumor-bearing animals. The highest expression of both c-jun and erb-2 occurred in the livers of animals bearing the EMT-6/CDDP tumor. Treatment of the animals with CDDP or cyclophosphamide, in general, resulted in increased expression of both genes at 6 h post treatment. The increased expression of these genes may impart metabolic changes in the tumors and/or hosts that contribute to the resistance of these tumors to specific antitumor alkylating agents.

Alkylating Agents↗
PubMed1995

Improved 20-hour canine lung preservation with a new solution--ET-Kyoto solution.

We developed a new solution, ET-Kyoto (ET-K) solution, and compared its efficacy in 20 h lung preservation with that of Euro-Collins (EC) solution in a canine left lung transplantation model. The lungs were flushed with ET-K solution (ET-K group, n = 5), with EC solution plus prostaglandin E1 (PGE1) pretreatment (EC + PGE1 group, n = 6) or with EC solution (EC group, n = 6), and were stored at 4 degrees C for 20 h. The function of left lung grafts was assessed 40, 70, and 130 min after transplantation. The arterial pressure of oxygen (PaO2) in the ET-K group was significantly greater than in the EC + PGE1 group (p < 0.05 or p < 0.01) and in the EC group (p < 0.01). The peak inspiratory pressure and wet to dry weight ratio in the ET-K group were significantly lower than in the EC + PGE1 group and in the EC group (p < 0.05 or p < 0.01). Pulmonary vascular resistance in the ET-K group 130 min after reperfusion was significantly lower than in the EC group (p < 0.05). All the transplanted lungs in the EC + PGE1 group and the EC group showed histological evidence of pulmonary edema, whereas all in the ET-K group showed no signs of edema. We concluded that ET-K solution is superior to EC solution with or without PGE1 pretreatment in 20 h canine lung preservation.

Animals↗
PubMed1994

Minocycline as a modulator of chemotherapy and hyperthermia in vitro and in vivo.

We tested the ability of the collagenase-inhibitor minocycline to increase the effectiveness of CDDP, BCNU and mitomycin C +/- hyperthermia. When tested in vitro in FSaIIC fibrosarcoma cells, exposure to minocycline (100 microM for 24 h) decreased the CDDP cytotoxicity at 37 degrees C and pH 7.40 in both normally oxygenated and hypoxic cells and decreased the cytotoxicity of CDDP at 42 degrees C or 43 degrees C in normally oxygenated cells while increasing the killing in hypoxic cells. When tested at pH 6.45, the presence of minocycline tended to protect both normally oxygenated and hypoxic cells from the cytotoxic effects of CDDP +/- hyperthermia. With exposure to BCNU, minocycline markedly protected both normally oxygenated and hypoxic cells at 37 degrees C at both pHs. As the temperature during the exposure to BCNU was increased to 42 degrees C or 43 degrees C, the protection afforded by minocycline diminished especially under low pH conditions where BCNU plus 43 degrees C was extremely cytotoxic to both normally oxygenated and hypoxic cells. One hour exposure to mitomycin C was more cytotoxic to hypoxic than normally oxygenated cells under all conditions of pH and temperature tested and the cytotoxicity of mitomycin C under each condition was increased by minocycline. Both CDDP and BCNU were much more cytotoxic toward FSaIIC tumors in vivo when drug administration was followed by local heating (43 degrees C, 30 min) of the tumor bearing limb. In each case, treatment with minocycline had little effect on tumor-cell killing. Treatment with mitomycin C and hyperthermia resulted in additive tumor-cell killing, and minocycline administration further increased that effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Human thymidine kinase CCAAT-binding protein is NF-Y, whose A subunit expression is serum-dependent in human IMR-90 diploid fibroblasts.

The nuclear protein interacting with the distal CCAAT box of human thymidine kinase (TK) gene promoter has been suggested to be a specific TK-CCAAT-binding protein, which is responsible for the serum-dependence of TK transactivation in normal human IMR-90 fibroblasts. By biochemical characterization, TK-CCAAT-binding protein was found to be distinct from other known CCAAT-binding proteins (Pang, J. H., and Chen, K. Y. (1993) J. Biol. Chem. 268, 2909-2916). In this study, we identify NF-Y, which is composed of Ya and Yb subunits, to be responsible for the TK-CCAAT binding activity in the crude nuclear extract from HL-60 cells. The interaction of NF-Y with the distal CCAAT box of the TK promoter in the crude extract appeared to be more heat-sensitive than that in the DNA affinity chromatography purified fraction. We have further established that the serum dependence of TK-CCAAT binding activity in normal IMR-90 fibroblasts is due to the decrement of NF-Ya, but not NF-Yb expression following serum-deprivation, and that such serum dependence is absent in HL-60 cells.

Base Sequence↗
PubMed1994

Detection of genes for heat-stable enterotoxin in Escherichia coli by biotinylated ST-DNA probes.

Reference strains of enterotoxigenic Escherichia coli (ETEC), non-enterotoxigenic Escherichia coli (non-ETEC), enteropathogenic Escherichia coli (EPEC), enteroinvasive Escherichia coli (EIEC), and other enteropathogenic bacteria were used to prove the reliability of BIO-ST-DNA probe hybridization. In addition, 417 strains of E. coli isolated from children with diarrheal diseases in Shanxi Children's Hospital were examined for BIO-ST-DNA probe hybridization. In the test, BIO-ST-DNA hybridization was compared with suckling mouse assay in identifying ST-ETEC. The results obtained by both methods showed no significant difference. It was found that identification of ST-ETEC using hybridization is a simple, sensitive and more practical method.

DNA Probes↗
PubMed1994

[Influence of sialic acid level in cultured pituitary cells on immunogenicity].

Many researches have demonstrated that cultured tissue or cells may reduce immunogenicity and can survive in a recipient if they are allografted or xenografted. The cause for this phenomenon remains uncertain. In this experiment, sialic acid (SA) content of BALB/C mice pituitary cells before and after culture was determined, and the influence of SA level on cell immunogenicity was studied by using the mixed lymphocyte reaction method and neuraminidase. The SA level was much higher in cultured cells than in uncultured cells. Cultured cells were found to have a reduced ability to stimulate splenocyte proliferation in allogeneic rats after the SA levels of the cells had been raised. Such ability could be restored by removing SA from the cell surface with sialidase. This suggests that the high SA levels in the cultured cells play an important role in reducing their immunogenicity.

Animals↗