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L W Hsu

Publications and source records attributed to L W Hsu.

13 recordsLinked to original sources
PubMed2001

Identification of two down-regulated genes in rat liver allografts by mRNA differential display.

Total RNA differential display (DD) using random primers was performed for rat orthotopic liver transplantation (OLT) models. DA (RT1a) donor livers were transplanted into DA, PVG (RT1c), and LEW (RT1l) recipients: (1) syngeneic OLT (DA-DA): no rejection occurs; (2) allogeneic OLT (DA-PVG): rejection occurs, but is naturally overcome without immunosuppression; (3) allogeneic OLT (DA-LEW): animals die of acute rejection within 14 days. cDNA was isolated from selected bands, re-amplified for sequencing, and confirmed by Northern blots. Two down-regulated genes were observed in day-7 allogeneic OLT livers (DA-PVG, DA-LEW), while they were consistently expressed in day-7 syngeneic OLT (DA-DA) livers. These two genes were identified as alpha-glutathione sulfotransferase (alpha-GST) Ya gene and estrogen sulfotransferase (EST), respectively. Northern blots confirmed that their expression was down-regulated in OLT (DA-PVG) livers on days 7-26 and gradually restored. The mRNA expression of GST and EST may be good markers to predict rejection or induction of tolerance.

Animals↗
PubMed2000

Clusterin may be involved in rat liver allograft tolerance.

Little is known about the possible role of complement inhibitors on tolerance induced by liver allografts. Clusterin, which is a plasma glycoprotein, inhibits cytolytic membrane attack complex (MAC) of complement by binding to soluble C5b-7 complex. The role of clusterin in relation to the naturally achieved tolerance in a rat orthotopic liver transplantation (OLT) has not been investigated before. Here we determined the kinetics of clusterin expression at different post-transplantation time points in a tolerogenic model (DA-PVG) where rejection was naturally overcome without any immunosuppressive drugs in comparison with the syngenic OLT model (DA-DA). Peripheral blood and liver tissues were taken from OLT at various post-operative time points. A strong expression of soluble clusterin was observed on post-transplantation day 7, which occurred at the peak of the rejection in this tolerogenic OLT model. The expression of clusterin remained strong even after tolerance was achieved. The intensity of clusterin expression was much stronger when compared with the syngenic OLT (DA-DA) model after OLT. A strong expression of clusterin mRNA was also observed in the tolerogenic model on post-OLT day (POD) 7 and the expression persisted when compared with the syngenic model on post-OLT day 60. Our data have shown that the strongest levels of clusterin during the reaction phase in tolerogenic OLT may be involved in tolerance induction.

Animals↗
PubMed2000

Effect of different concentrations of recombinant leukemia inhibitory factor on different development stage of mouse embryo in vitro.

PURPOSE: To assess the influence of different concentrations of recombinant human leukemia inhibitory factor (LIF) on the in vitro development of mouse embryos. METHODS: The 2- to 4-cell embryos of CB6F1 mice were cultured in the human tubal fluid (HTF) media containing different concentrations of LIF. Mouse embryos were divided into seven groups: (1) HTF; (2) 1500 IU/ml LIF; (3) 1000 IU/ml LIF; (4) 750 IU/ml LIF; (5) 500 IU/ml LIF; (6) 250 IU/ml LIF; (7) 125 IU/ml LIF. The embryonic numbers of different stages including 5-8 cell, 9-16 cell, morula, blastocyst, and hatching blastocyst were recorded. RESULTS: The percentage of early embryo stage (2-cell embryos to 6- to 16-cell stages) in all groups were nonsignificantly different. There were higher formation rates of preimplantation embryos (morula to hatching blastocyst) in groups 2, 3, 4, and 5 than in groups 1, 6 and 7. CONCLUSIONS: LIF has positive effects on preimplantation embryo development and has nonsignificant influence on the early embryo development. The lowest concentration of LIF which could provide the optimal embryo development is 500 IU/ml.

Animals↗
PubMed2000

Prolonged culture of human cryopreserved embryos with recombinant human leukemia inhibitory factor.

PURPOSE: To evaluate the efficiency of recombinant human leukemia inhibitory factor (LIF) in the prolonged culture of human cryopreserved-thawing embryos. METHODS: After thawing, all embryos were divided into four groups: (1) Human tubal fluid (HTF), (2) HTF + LIF, (3) M3TH medium, and (4) M3TH medium plus LIF. Following prolonged culture, embryo development in each group was compared. RESULTS: In embryo development from about the 2- to 4-cell to 9- to 16-cell stage, there were nonsignificant differences between each group. There was lower morula formation rate in group 1 (6.9%) than those in other groups (23.2%, 19.7%, 23.1%). The lower blastocyst formation in group 1 and 3 (0%, 0%) than those in group 2 and 4 (11.0%, 12.8%) were noted. CONCLUSIONS: LIF is beneficial for preimplantation embryos. LIF does not influence the early embryo development. LIF-supplemented HTF provided a similar culture environment for thawing embryos as LIF-supplemented M3TH medium.

Blastocyst↗
PubMed1999

Recombinant human leukemia inhibitory factor enhances the development of preimplantation mouse embryo in vitro.

OBJECTIVE: To assess the effect of recombinant human leukemia inhibitory factor (rhLIF) on mouse embryos in vitro. DESIGN: Controlled prospective study. SETTING: Academic research environment. ANIMAL(S): Female CB6F1 mice between 6 and 8 weeks old. INTERVENTION(S): Mice were divided randomly into three groups, which included a control group in an in vivo study (group I) and two groups in an in vitro study (groups II and III). Mice were killed at 116-120 hours (group I) and 44-48 hours (groups II and III) after hCG injection. Two-cell embryos (groups II and III) and blastocysts (group I) were obtained. Embryos in group II were cocultured with human tubal fluid (HTF) + 0.5% human serum albumin and in group III with HTF + rhLIF (1,000 U/mL) under paraffin oil. MAIN OUTCOME MEASURE(S): The embryonic numbers in different stages were recorded and compared. RESULT(S): Similar early embryo development to the four- to eight-cell and morula stages was noted between groups II and III (87.3% versus 91.0% and 74.6% versus 87.1%, respectively). However, further embryo development to the blastocyst, expanded blastocyst, and hatching blastocyst in group II (48.1%, 31.7%, and 18.5%, respectively) was lower than that in group III (83.6%, 53.7%, and 37.8%). CONCLUSION(S): RhLIF does not provide obvious stimulation in the early mouse embryo. However, rhLIF has positive effects on preimplantation blastocyst growth, differentiation, and hatching.

Animals↗
PubMed1995

Nutritional value for growing turkeys of corn of light test weight.

An experiment was conducted to determine the relationship between test weight of corn and growth, efficiency of feed utilization, nutrient retention, and carcass composition of young turkeys. The MEn values of corn were also measured. Two samples of corn differing substantially in test weight were fed to male turkey poults (Nicholas Large White) from 1 to 20 d of age. The test weights of the light-weight corn and the normal-weight corn were 55 kg/hL (43 lb/bu) and 70 kg/hL (54 lb/bu), respectively. The light-weight corn was lower in crude protein concentration (6.63%) than the normal-weight corn (8.53%). The determined MEn of the corn samples did not differ (3.22 vs 3.25 kcal/g). The light-weight corn diet had modest adverse effects on growth and feed efficiency of poults during the 1 to 7 d after hatching. Poult carcass composition and retention of nitrogen and energy were not affected by the test weight of corn.

Animal Feed↗
PubMed1994

Identification of two elements involved in regulating expression of the murine leukaemia inhibitory factor gene.

Mouse leukaemia inhibitory factor (LIF) is a polyfunctional cytokine which exhibits multiple functions in vitro and in vivo. Two forms of LIF cDNA, differing at their 5' ends, have been described encoding either diffusible (D-LIF) or matrix-associated (M-LIF) forms of the protein [Rathjen, Toth, Willis, Heath and Smith (1990) (Cell 62, 1105-1114]. The present report describes the DNA sequence and functional characterization of the murine LIF gene and its surrounding transcriptional regulatory elements. Transient transfection of constructs containing the LIF gene and various amounts of 5'-non-coding sequence failed to give detectable levels of expression, suggesting the presence of inhibitory sequences within the LIF gene. Stable cell lines were produced by transfection of experimental constructs containing various lengths of 5'-non-coding sequence of the LIF gene, or the heterologous phosphoglycerate kinase promoter, linked to an LIF/neomycin-resistance-hybrid-coding sequence. The frequency of recovery of stable clones indicated that sequences located in the first intron between the transcriptional start sites for D-LIF and M-LIF act to suppress expression of the gene in most genomic locations. This region is rich in GC residues and has been shown to be hypomethylated in vitro [Kaspar, Dvorak and Bartunek (1993) FEBS Lett. 319, 159-162]. Analysis of the LIF/neomycin-resistance transgene expression in these stable cell clones demonstrated that transcripts containing the M-LIF or D-LIF exons required the presence of sequences located between -1200 and -3200 in the LIF gene. In the absence of these sequences, transcription is initiated elsewhere within the first intron. These sequences can be replaced by the heterologous phosphoglycerate kinase promoter. Deletion of the GC-rich region between the D-LIF and M-LIF transcriptional start sites results in the appearance of transcripts that do not splice out the first intron of the LIF gene. These may result from gene or promoter trapping of the LIF gene. Sequence analysis of the region between -1200 and -3200 revealed a number of minimal steroid-response elements, regions of similarity to DNAase I-hypersensitive sites in the uteroglobin gene and a region of alternating purine/pyrimidine sequence. This study therefore defines two important regulatory regions in the LIF gene: a GC-rich region in the first intron and a distal 'enhancer' located between -3200 and -1200.

Amino Acid Sequence↗
PubMed1990

Growth and differentiation factors of pluripotential stem cells.

The mammalian embryo develops as a quasi-stem cell system whose differentiation and pluripotentiality in vitro is controlled by a single regulatory factor, Differentiation Inhibiting Activity/Leukemia Inhibitory Factor (DIA/LIF). DIA/LIF is expressed in two distinct functional forms, derived from the use of alternate transcriptional start sites, one of which is freely diffusible and the other tightly associated with the extracellular matrix. The dissemination of the DIA/LIF signal is therefore under specific molecular control. The expression of DIA/LIF in vitro is both developmentally programmed and controlled by the action of other growth factors, the most notable of which are members of the fibroblast growth factor family expressed by the stem cells themselves. This indicates that differentiation and proliferation in early development of the mouse are controlled, at least in part, by an interactive network of specific growth and differentiation regulatory factors.

Amino Acid Sequence↗
PubMed1989

Response to and concentration of interleukin-2 in patients with nasopharyngeal carcinoma.

To seek beneficial immunomodulation with interleukin-2 (IL-2) for patients with nasopharyngeal carcinoma (NPC), a study was conducted of the response to and concentration of IL-2 by mononuclear cells (MNC) from 45 NPC patients who had been pathologically verified, but pre-treatment, at the time they were studied. Thirty-eight normal healthy controls were studied simultaneously. Lymphocyte subsets did not change much after IL-2 stimulation in either NPC patients or the controls. A decreased IL-2 concentration was found in NPC, and a trend of inverse correlation to clinical staging was detected; the more advanced stage, the less concentration of IL-2. It was concluded that there was a normal response to and decreased concentration of, IL-2 in NPC patients. Whether decreased concentration of IL-2 in NPC patients resulted from decreased production or increased consumption is not clear. A further research of IL-2 immunomodulation in NPC patients should be done before its clinical application.

Humans↗