JNK is a key regulator of many cellular events, including programmed cell death (apoptosis). In the absence of NF- κB activation, prolonged JNK activation contributes to TNF-α induced apoptosis. JNK is also essentia...JNK is a key regulator of many cellular events, including programmed cell death (apoptosis). In the absence of NF- κB activation, prolonged JNK activation contributes to TNF-α induced apoptosis. JNK is also essential for UV induced apoptosis. However, recent studies reveal that JNK can suppress apoptosis in IL-3-dependent hematopoietic cells via phosphorylation of the proapoptotic Bcl-2 family protein BAD. Thus, JNK has pro- or antiapoptotic functions, depend- ing on cell type, nature of the death stimulus, duration of its activation and the activity of other signaling pathways.展开更多
AIM: TO investigate the immunogenicity of candidate DNA vaccine against hepatitis C virus (HCV) delivered by two plasmids expressing HCV envelope protein 1 (El) and envelope protein 2 (E2) antigens respectively and to...AIM: TO investigate the immunogenicity of candidate DNA vaccine against hepatitis C virus (HCV) delivered by two plasmids expressing HCV envelope protein 1 (El) and envelope protein 2 (E2) antigens respectively and to study the effect of CpG adjuvant on this candidate vaccine.METHODS: Recombinant plasmJds expressing HCV EI and E2 antigens respectively were used to simultaneously inoculate mice with or without CpG adjuvant. Antisera were then collected and tJters of antJ-HCV antibodies were analyzed by ELISA. One month after the last injection, animals were sacrificed to prepare single-cell suspension of splenocytes.These cells were subjected to HCV antigen specific proliferaion assays and cytokine secretion assays to evaluate the cellular immune responses of the vaccinated animals.RESULTS: Antibody responses to HCV EI and E2 antigens were detected in vaccinated animals. Animals receiving CpG adjuvant had slightly lower titers of anti-HCV antibodies in the sera, while the splenocytes from these animals showed higher HCV-antigen specific proliferation. Analysis of cytokine secretion from the splenocytes was consistent with the above results. While no antigen-specific IL-4 secretion was detected for all vaccinated animals, HCV antigen-specific INF-γ, secretion was detected for the splenocytes of vaccinated animals. CpG adjuvant enhanced the secretion of INF-γ, but did not change the profile of IL-4 secretion.CONCLUSION: Vaccination of mice with plasmids encoding HCV E1 and E2 antigens induces humoral and cellular immune responses. CpG adjuvant significantly enhances the cellular immune response.展开更多
AIM: To explore the role of hepatitis C virus (HCV) envelope protein 2 (E2) in the induction of apoptosis. METHODS: A carboxyterminal truncated E2 (E2-661) was transiently expressed in several cultured mammalian cell ...AIM: To explore the role of hepatitis C virus (HCV) envelope protein 2 (E2) in the induction of apoptosis. METHODS: A carboxyterminal truncated E2 (E2-661) was transiently expressed in several cultured mammalian cell lines or stably expressed in Chinese hamster ovary (CliO) cell line. Cell proliferation was assessed by ^3H thymidine uptake. Apoptosis was examined by Hoechst 33258 staining, flow cytometry and DNA fragmentation analysis. RESULTS: Reduced proliferation was readily observed in the E2-661 expressing cells. These cells manifested the typical features of apoptosis, including cell shrinkage, chromatin condensation and hypodiploid genomic DNA content. Similar apoptotic cell death was observed in an E2-661 stably expressing cell line. CONCLUSION: HCV E2 can induce apoptosis in cultured mammalian cells.展开更多
This paper reports observations of significant synergistic effects between dielectric barrier discharge (DBD) plasmas and Cu-ZSM-5 catalysts for C2H4 selective reduction of NOx at 250 °C in the presence of excess...This paper reports observations of significant synergistic effects between dielectric barrier discharge (DBD) plasmas and Cu-ZSM-5 catalysts for C2H4 selective reduction of NOx at 250 °C in the presence of excess oxygen by using a one-stage plasma-over-catalyst (POC) reactor. With the reactant gas mixture of 530 ppm NO, 650 ppm C2H4, 5.8% O2 in N2 and GHSV = 12000 h-1, the pure catalytic, pure plasma-induced (discharges over fused silica pellets) and plasma- catalytic (in the POC reactor) NOx conversion are 39%, 1.5% and 79%, respectively. The in-situ optical emission spectra of the reactive systems imply some short-lived active species formed from plasma-induced and plasma-catalytic processes may be responsible to the observed synergistic effects in this one-stage POC system.展开更多
Amylose content in rice endosperm is one of the key determinants of rice eating and cooking quality, and the poor quality of indica hybrid rice is closely related to the high amylose level in rice grains. In order to ...Amylose content in rice endosperm is one of the key determinants of rice eating and cooking quality, and the poor quality of indica hybrid rice is closely related to the high amylose level in rice grains. In order to improve the grain quality of the indica hybrid rice by genetic engineering, an antisense fragment of rice waxy gene, driven by the 5’-franking sequences of the rice waxy gene, was successfully introduced into three major parent lines of indica hybrid rice, all contain a high amylose level in the grains, via Agrobacte-rium, and more than 100 hygromycin-resistant plants were regenerated. The analysis of PCR amplification and Southern blots indicated that the T-DNA containing the antisense waxy gene had been integrated into the genome of transgenic rice plants. Most of the primary transgenic rice plants grew normally, and the mature seeds from these transgenic plants were performed for analysis of the amylose content. The results showed that the amylose content in the endosperm of some grains展开更多
AIM: To study effect of operation-synchronizing transfusion of apoptotic spleen cells from donor rats on acute rejection of recipient rats after liver transplantation. METHODS: Two of Wistar rats were chosen randomly ...AIM: To study effect of operation-synchronizing transfusion of apoptotic spleen cells from donor rats on acute rejection of recipient rats after liver transplantation. METHODS: Two of Wistar rats were chosen randomly for normal liver pathology control and ten of SD rats chosen randomly for liver function control as blank group (no operation). The rest of Wistar and SD rats were divided into four groups: control group (only liver transplantation), Dex group (donors receiving intraperitoneal injection of dexamethasone), SpC group (recipients receiving infusion of spleen cells of donors), Dex-SpC group (recipients receiving infusion of apoptotic spleen cells of donors), with each group except blank group, containing 10 SD rats and 10 Wistar rats, respectively. Wistar rats received liver transplantation from SD rats, in the meantime they received infusion of spleen cells of donors, which were induced by an intraperitoneal injection of dexamethasone (3 mg/(d.kg)·b.w) for three days before liver transplantation. The serum alanine transaminase (ALT), total bilirubin (T bili), liver pathological changes and survival time were analysed. Statistical analysis was carried out using SPSS 10.0 for Windows. Differences of the parametric data of ALT in means were examined by one-way ANOVA. Differences of ALT between two groups were examined by LSD. Differences of the nonparametric data of T bili in means and scores of pathology classification for acute rejection were examined by Kruskal-Willis H test. The correlations between ALT and T bili were analysed by Bivariate. Kaplan-Meier curves were used to demonstrate survival distribution. The log-rank test was used to compare the survival data. RESULTS: There were significant differences in ALT of the five groups (F= 23.164 P= 0.000), and ALT in Dex-SpC group was significantly higher than that in blank control, control, Dex, and SpC groups (P = 0.000), and ALT in SpC group was significantly higher than that in blank control (P= 0.000), control (P= 0.004), and Dex groups (P= 0.02). 展开更多
Insertional mutagenesis based on maize Activator/Dissociator (Ac/Ds) transposons is becoming a ma- jor approach used to produce a saturated mutant collection in rice. In this research, Ds-T-DNA trans- formed homozygot...Insertional mutagenesis based on maize Activator/Dissociator (Ac/Ds) transposons is becoming a ma- jor approach used to produce a saturated mutant collection in rice. In this research, Ds-T-DNA trans- formed homozygotes were crossed with Ac-T-DNA transformed homozygotes in order to establish an Ac/Ds transposon system in rice. The successive investigation of Ds transposition from F1 to F5 gen- erations indicated that the frequencies of germinal transposition increased over successive genera- tions and reached 54.2% in F3 generation. The Ds transposition pattern revealed that a Ds transposition induced an approximately 170-bp deletion of T-DNA sequence and another Ds transposition carried a 272-bp T-DNA sequence. Using thermal asymmetric interlaced PCR (TAIL-PCR), some flanking se- quences of the Ds element were amplified. Analyses of 17 Ds-flanking sequences showed that five Ds were inserted into gene regions. The Ds could transpose not only to the linked sites but also to the unlinked sites. The frequency of inter-chromosomal transposition of Ds was 33.3%.展开更多
Expressed Sequence Tag (EST) analysis has pioneered genome-wide gene discovery and expression profiling. In order to establish a gene expression index in the rice cultivar indica, we sequenced and analyzed 86,136 ESTs...Expressed Sequence Tag (EST) analysis has pioneered genome-wide gene discovery and expression profiling. In order to establish a gene expression index in the rice cultivar indica, we sequenced and analyzed 86,136 ESTs from nine rice cDNA libraries from the super hybrid cultivar LYP9 and its parental cultivars. We assembled these ESTs into 13,232 contigs and leave 8,976 singletons. Overall, 7,497 sequences were found similar to the existing sequences in GenBank and 14,711 are novel. These sequences are classified by molecular function, biological process and pathways according to the Gene Ontology. We compared our sequenced ESTs with the publicly available 95,000 ESTs from japonica, and found little sequence variation, despite the large difference between genome sequences. We then assembled the combined 173,000 rice ESTs for further analysis. Using the pooled ESTs, we compared gene expression in metabolism pathway between rice and Arabidopsis according to KEGG. We further profiled gene expression patterns in different tissues, developmental stages, and in a conditional sterile mutant, after checking the libraries are comparable by means of sequence coverage. We also identified some possible library specific genes and a number of enzymes and transcription factors that contribute to rice development.展开更多
Over 3000 rice plants with T-DNA carrying a Ds element were constructed by Agro-bacterium tumefaciens mediation. Using inverse PCR methodology, 590 unique right flanking sequences of T-DNA (Ds) were retrieved from ind...Over 3000 rice plants with T-DNA carrying a Ds element were constructed by Agro-bacterium tumefaciens mediation. Using inverse PCR methodology, 590 unique right flanking sequences of T-DNA (Ds) were retrieved from independent transformants and classified into six main types on the basis of the origin of filler DNA between the right border of T-DNA and flanking sequence of rice genome. Type I sequences were the most common and showed canonical in-tegration that T-DNA right border was followed by rice genome sequence with or without filler DNA of no more than 50 bp, while type II sequences displayed a vector-genome combination that T-DNA right border was followed by a vector fragment and then connected with rice genome sequence. The location and distribution of 340 type I and II flanking sequences on the rice chromosome were determined using BLAST analysis. The 340 Ds insertions at an average in-terval of 0.8 megabase (Mb) constructed a basic framework of Ds starter points on whole rice chromosomes. The frequency of T-DNA (Ds) inserted into the exons of predicted genes on chromosome one was 21%. Knowledge of T-DNA (Ds) locations on chromosomes will prove to be a useful resource for isolating rice genes by Ds transposon tagging as these Ds insertions can be used as starting lines for further mutagenesis.展开更多
AIM: To explore the properties of hypervariable region 1(HVR1) in the envelope 2 gene of hepatitis C virus by analyzing the reactivity of HVR1 fusion proteins from different Chinese HCV strains with sera of patients w...AIM: To explore the properties of hypervariable region 1(HVR1) in the envelope 2 gene of hepatitis C virus by analyzing the reactivity of HVR1 fusion proteins from different Chinese HCV strains with sera of patients with chronic hepatitis C and by comparing their reactivity between interferon therapy responders and non-responders.METHODS: Gene fragments of HVR1 of four HCV strains (three genotype 1b and one genotype 2a) were amplified from pGEMT-E2 plasmids and sub-cloned into pQE40vectors respectively to construct recombinant expression plasmids which expressed HVR1 fused downstream to DHFR in Escherichia coli strain TG1. The purified DHFRHVR1 proteins were then used to detect the anti-HVR1antibodies in 70 serum samples of patients with chronic hepatitis C.RESULTS: Four DHFR- HVR1 fusion proteins were successfully expressed in E.coli (320-800 ug fusion proteins per 100 ml culture). Each fusion protein (SH1b, BJ1b,SD1b and SD2a) reacted with 72.8 % (51/70), 60 % (42/70), 48.6 % (34/70), and 58.6 % (41/70) of the anti-HCV positive patients' sera respectively by ELISA. 57.1% (4/7) of non responders reacted with all four HVR1 fusion proteins, while only 15.3 % (2/13) of responders reacted with all of them. The O.D. values of sera from IFN therapy responders were significantly higher than those of non responders (P＜0.05).CONCLUSION: The selected HVR1 fusion proteins expressed in E. coli can broadly react with HCV-infected patients' sera. The intensity and/or quality of the immune response against HCV may be a critical factor determining the response to interferon treatment. With the evolution of virus strains, anti-HVR1 antibodies can not neutralize all the quasispecies. A polyvalent and high immunogenic vaccine comprising a mixture of several HVR1 sequences that cover the reactivity of most HCV isolates may be useful.展开更多
Irradiation-induced impurity segregation to grain boundaries is one of the important radiation effects on materials. For this reason, phosphorus segregation to prior austenite grain boundaries in a P-doped 2.25Cr1Mo s...Irradiation-induced impurity segregation to grain boundaries is one of the important radiation effects on materials. For this reason, phosphorus segregation to prior austenite grain boundaries in a P-doped 2.25Cr1Mo steel subjected to neutron irradiation is examined using field emission gun scanning transmission electron microscopy (FEGSTEM) with energy dispersive X-ray microanalysis (EDX). The steel samples are irradiated around 270 and 400℃, respectively. The irradiation dose rate and dose are -1.05×10-8 dpa/s and -0.042 dpa respectively for 270℃ irradiation, and 1.7×10-8 dpa/s and 0.13 dpa respectively for 400℃ irradiation. The FEGSTEM results indicate that there is no apparent phosphorus segregation during 270℃ irradiation but there is some during 400℃ irradiation.展开更多
The fluorescence emission and X-ray diffraction of magenesium 8-hydroxyquinoline complex(Mgq2) have been measured at high pressure up to 14 GPa.It has been found that pressure can influence the emission dramatically.A...The fluorescence emission and X-ray diffraction of magenesium 8-hydroxyquinoline complex(Mgq2) have been measured at high pressure up to 14 GPa.It has been found that pressure can influence the emission dramatically.At relative lower pressure(less than 2.5GPa) the fluorescence of Mgq2 changes slightly,but the emission drops quickly with increase of the pressure when the pressure gets higher than 2.5GPa.The results of in situ energy dispersive X-ray diffraction at high pressure with synchrotron radiation indicate that there is a phase transition at about 2.5-3GPa for Mgq2 crystal.2001 Elsevier Science B.V.All rights reserved.展开更多
This study was undertaken to have a better understand for the process and the underlying mechanisms to limit macrophage activation and population of activated macrophages.A comprehensive kinetics of cytokine productio...This study was undertaken to have a better understand for the process and the underlying mechanisms to limit macrophage activation and population of activated macrophages.A comprehensive kinetics of cytokine production was performed in murine peritoneal macrophages recovered from Balb/c mice at various time during the course of an intraperitoneal injection with thioglycollate (TG).The expression of cell surface molecules such as MHC-Ⅰ,MHC-Ⅱ,B7-1 and B7-2 of these macrophages were also determined by flow cytometry.The present findings of our research suggested that the population of activated macrophages and the activation of macrophages (including cytokines production and expression of cell surface functional molecules) were strictly controlled during inflammation process.This is one of the important mechanisms to retain the host homeostasis.Cellular & Molecular Immunology.2004;1(1):57-62.展开更多
A high pressure energy dispersive X-ray diffraction apparatus on 3W1A bearmline,at BSRF,is described.A ten-Poles permanent magnetic wiggler provided white X-ray beam.The extreme high pressure up to 115GPa has been obt...A high pressure energy dispersive X-ray diffraction apparatus on 3W1A bearmline,at BSRF,is described.A ten-Poles permanent magnetic wiggler provided white X-ray beam.The extreme high pressure up to 115GPa has been obtained by a modified Mao-Bell diamond anvil cell.A motorized loading system with strain sensor can finely control the pressure change.The in situ experimental procedures are described.Some applications are also presented.2001 Elsevier Science B.V.All rights reserved.展开更多
Objective To study the effect of hypertension on inducible isoform of nitrogen oxide syn- theses (iNOS) expression and reproductive function in testes of Dahl hypertensive rats Method The iNOS expression in Dahl rat...Objective To study the effect of hypertension on inducible isoform of nitrogen oxide syn- theses (iNOS) expression and reproductive function in testes of Dahl hypertensive rats Method The iNOS expression in Dahl rat testes was localized and assayed semi-quan- titatively by immunohistochemistry. Results iNOS was expressed and localized predominantly in the cytoplasm of Sertoli and Leydig cells in both normal and hypertensive rats. However, in the early stage of hypertension, the expression of iNOS was stronger in testes than that of the normal rats (P<0.05). With the development, the staining intensity of iNOS decreased gradu- ally in the late stage. Moreover, the level of testosterone decreased with the increase of blood pressure. But in vitro, there was no difference in the expression of iNOS between cultured Sertoli cells from normal rats and hypertensive rats. Conclusion High-salt food induced hypertension in Dahl rats, which was character- ized by the high expression of iNOS in rat Sertoli and Leydig cells; excessive NO produced by iNOS reduced the level of testosterone in testicle artery, and may thus affect the reproductive function of rats testis.展开更多
To make it possible for the thermal wave theory on temperature oscillation (TO) effects in living tissues to be founded on the substantial experimental basis, a series of typical decisive experiments in vivo as well a...To make it possible for the thermal wave theory on temperature oscillation (TO) effects in living tissues to be founded on the substantial experimental basis, a series of typical decisive experiments in vivo as well as in artificially simulating constructions were carried out. Conclusions obtained including some other scholars' animal experimental results all greatly support the thermal wave viewpoint qualitatively.A few experimental facts used hot to be easily understood from the classical viewpoint are also well reinterpreted. The revealing on the thermal wave mechanisms of TO in living tissues is a brand new discovery and deep insight into this important thermophysiological phenomenon. It may possibly promote new investigations on the corresponding topics in the field of bioheat transfer science.展开更多
AIM: To explore the possibility of expressing hepatitis C virus (HCV) envelope protein 1 (E1) in Escherichia coli(E, coli) and to test the purified recombinant E1 proteins for clinical and research applications. METHO...AIM: To explore the possibility of expressing hepatitis C virus (HCV) envelope protein 1 (E1) in Escherichia coli(E, coli) and to test the purified recombinant E1 proteins for clinical and research applications. METHODS: C-terminally truncated E1 fragments were expressed in E, coli as hexa-histidine-tagged fusion proteins. The expression products were purified under denaturing conditions using immobilized-metal affinity chrbmatography. Purified E1 proteins were used to immunize rabbits. Rabbit anti-sera thus obtained were reacted with both E. coli- and mammalian cell-expressed E1 glycoproteins as detected by Western blot. RESULTS: Full-length E1 protein proved difficult to express in E. coli, C-terminally truncated E1 was successfully expressed in E. coli as hexa-histidine-tagged recombinant fusion protein and was purified under denaturing conditions on Ni2+-NTA agarose. Rabbit anti-sera raised against purified recombinant E1 specifically reacted with mammalian cell-expressed E1 giycoproteins in Western blot. Furthermore, E. coli-derived E1 protein was able to detect animal antibodies elicited by E1-based DNA immunization. CONCLUSION: These results demonstrate that the prokaryotically expressed E1 proteins share identical epitopes with eukaryotically expressed E1 glycoprotein. The E coli-derived E1 proteins and corresponding antisera can become useful tools in anti-HCV vaccine research.展开更多
OsEBP-89 is a transcription factor gene of rice. It contains two introns. Using RT-PCR and Southern hybridization to study OsEBP-89 tissue-specific expression, we found that its first intron (115 bp in length) of its ...OsEBP-89 is a transcription factor gene of rice. It contains two introns. Using RT-PCR and Southern hybridization to study OsEBP-89 tissue-specific expression, we found that its first intron (115 bp in length) of its was retained in a fraction of its transcripts of this gene in rice developing seeds. Furthermore, two OsEBP-89 cDNA clones (c89L and c89LH) were screened from a rice cDNA library. Sequence analysis revealed that the first intron was retained in c89L clone, whereas, both the first and second intron sequences were spliced in c89LH. In addition to developing seeds, the first intron unspliced transcripts of OsEBP-89 are detected in leaves and roots of rice, too. However, the ratio of the first intron unspliced to spliced OsEBP-89 transcripts varied in different tissues examined. The potential biological significance of intron retention in OsEBP-89 transcript was discussed.展开更多
文摘JNK is a key regulator of many cellular events, including programmed cell death (apoptosis). In the absence of NF- κB activation, prolonged JNK activation contributes to TNF-α induced apoptosis. JNK is also essential for UV induced apoptosis. However, recent studies reveal that JNK can suppress apoptosis in IL-3-dependent hematopoietic cells via phosphorylation of the proapoptotic Bcl-2 family protein BAD. Thus, JNK has pro- or antiapoptotic functions, depend- ing on cell type, nature of the death stimulus, duration of its activation and the activity of other signaling pathways.
基金Supported by the National High Technology R&D Program of China,No.2001AA215171
文摘AIM: TO investigate the immunogenicity of candidate DNA vaccine against hepatitis C virus (HCV) delivered by two plasmids expressing HCV envelope protein 1 (El) and envelope protein 2 (E2) antigens respectively and to study the effect of CpG adjuvant on this candidate vaccine.METHODS: Recombinant plasmJds expressing HCV EI and E2 antigens respectively were used to simultaneously inoculate mice with or without CpG adjuvant. Antisera were then collected and tJters of antJ-HCV antibodies were analyzed by ELISA. One month after the last injection, animals were sacrificed to prepare single-cell suspension of splenocytes.These cells were subjected to HCV antigen specific proliferaion assays and cytokine secretion assays to evaluate the cellular immune responses of the vaccinated animals.RESULTS: Antibody responses to HCV EI and E2 antigens were detected in vaccinated animals. Animals receiving CpG adjuvant had slightly lower titers of anti-HCV antibodies in the sera, while the splenocytes from these animals showed higher HCV-antigen specific proliferation. Analysis of cytokine secretion from the splenocytes was consistent with the above results. While no antigen-specific IL-4 secretion was detected for all vaccinated animals, HCV antigen-specific INF-γ, secretion was detected for the splenocytes of vaccinated animals. CpG adjuvant enhanced the secretion of INF-γ, but did not change the profile of IL-4 secretion.CONCLUSION: Vaccination of mice with plasmids encoding HCV E1 and E2 antigens induces humoral and cellular immune responses. CpG adjuvant significantly enhances the cellular immune response.
基金Supported by the National High Technology Research and Development Program of China,No.2001AA215171
文摘AIM: To explore the role of hepatitis C virus (HCV) envelope protein 2 (E2) in the induction of apoptosis. METHODS: A carboxyterminal truncated E2 (E2-661) was transiently expressed in several cultured mammalian cell lines or stably expressed in Chinese hamster ovary (CliO) cell line. Cell proliferation was assessed by ^3H thymidine uptake. Apoptosis was examined by Hoechst 33258 staining, flow cytometry and DNA fragmentation analysis. RESULTS: Reduced proliferation was readily observed in the E2-661 expressing cells. These cells manifested the typical features of apoptosis, including cell shrinkage, chromatin condensation and hypodiploid genomic DNA content. Similar apoptotic cell death was observed in an E2-661 stably expressing cell line. CONCLUSION: HCV E2 can induce apoptosis in cultured mammalian cells.
基金supported by the National Natural Science Foundation of China(Grant No.20077005)the National High Technology Research and Development Program("863 Programm”)of China(Grant No.2002AA649140)the Provincial Grants of Science and Technology of Liaoning,China(No.20022112).
文摘This paper reports observations of significant synergistic effects between dielectric barrier discharge (DBD) plasmas and Cu-ZSM-5 catalysts for C2H4 selective reduction of NOx at 250 °C in the presence of excess oxygen by using a one-stage plasma-over-catalyst (POC) reactor. With the reactant gas mixture of 530 ppm NO, 650 ppm C2H4, 5.8% O2 in N2 and GHSV = 12000 h-1, the pure catalytic, pure plasma-induced (discharges over fused silica pellets) and plasma- catalytic (in the POC reactor) NOx conversion are 39%, 1.5% and 79%, respectively. The in-situ optical emission spectra of the reactive systems imply some short-lived active species formed from plasma-induced and plasma-catalytic processes may be responsible to the observed synergistic effects in this one-stage POC system.
基金This work was supported by the State "863" High-Tech Project (Grant No. 2001AA212101)the Chinese Department of Science and Technology (Grant No. J99-A-005)High-Tech Project of Jiangsu Province (Grant No. BG2001302).
文摘Amylose content in rice endosperm is one of the key determinants of rice eating and cooking quality, and the poor quality of indica hybrid rice is closely related to the high amylose level in rice grains. In order to improve the grain quality of the indica hybrid rice by genetic engineering, an antisense fragment of rice waxy gene, driven by the 5’-franking sequences of the rice waxy gene, was successfully introduced into three major parent lines of indica hybrid rice, all contain a high amylose level in the grains, via Agrobacte-rium, and more than 100 hygromycin-resistant plants were regenerated. The analysis of PCR amplification and Southern blots indicated that the T-DNA containing the antisense waxy gene had been integrated into the genome of transgenic rice plants. Most of the primary transgenic rice plants grew normally, and the mature seeds from these transgenic plants were performed for analysis of the amylose content. The results showed that the amylose content in the endosperm of some grains
基金Supported by the National Natural Science Foundation of China, No. 39970705
文摘AIM: To study effect of operation-synchronizing transfusion of apoptotic spleen cells from donor rats on acute rejection of recipient rats after liver transplantation. METHODS: Two of Wistar rats were chosen randomly for normal liver pathology control and ten of SD rats chosen randomly for liver function control as blank group (no operation). The rest of Wistar and SD rats were divided into four groups: control group (only liver transplantation), Dex group (donors receiving intraperitoneal injection of dexamethasone), SpC group (recipients receiving infusion of spleen cells of donors), Dex-SpC group (recipients receiving infusion of apoptotic spleen cells of donors), with each group except blank group, containing 10 SD rats and 10 Wistar rats, respectively. Wistar rats received liver transplantation from SD rats, in the meantime they received infusion of spleen cells of donors, which were induced by an intraperitoneal injection of dexamethasone (3 mg/(d.kg)·b.w) for three days before liver transplantation. The serum alanine transaminase (ALT), total bilirubin (T bili), liver pathological changes and survival time were analysed. Statistical analysis was carried out using SPSS 10.0 for Windows. Differences of the parametric data of ALT in means were examined by one-way ANOVA. Differences of ALT between two groups were examined by LSD. Differences of the nonparametric data of T bili in means and scores of pathology classification for acute rejection were examined by Kruskal-Willis H test. The correlations between ALT and T bili were analysed by Bivariate. Kaplan-Meier curves were used to demonstrate survival distribution. The log-rank test was used to compare the survival data. RESULTS: There were significant differences in ALT of the five groups (F= 23.164 P= 0.000), and ALT in Dex-SpC group was significantly higher than that in blank control, control, Dex, and SpC groups (P = 0.000), and ALT in SpC group was significantly higher than that in blank control (P= 0.000), control (P= 0.004), and Dex groups (P= 0.02).
基金Supported by National Basic Research Program of China (Grant No. G19990116)
文摘Insertional mutagenesis based on maize Activator/Dissociator (Ac/Ds) transposons is becoming a ma- jor approach used to produce a saturated mutant collection in rice. In this research, Ds-T-DNA trans- formed homozygotes were crossed with Ac-T-DNA transformed homozygotes in order to establish an Ac/Ds transposon system in rice. The successive investigation of Ds transposition from F1 to F5 gen- erations indicated that the frequencies of germinal transposition increased over successive genera- tions and reached 54.2% in F3 generation. The Ds transposition pattern revealed that a Ds transposition induced an approximately 170-bp deletion of T-DNA sequence and another Ds transposition carried a 272-bp T-DNA sequence. Using thermal asymmetric interlaced PCR (TAIL-PCR), some flanking se- quences of the Ds element were amplified. Analyses of 17 Ds-flanking sequences showed that five Ds were inserted into gene regions. The Ds could transpose not only to the linked sites but also to the unlinked sites. The frequency of inter-chromosomal transposition of Ds was 33.3%.
文摘Expressed Sequence Tag (EST) analysis has pioneered genome-wide gene discovery and expression profiling. In order to establish a gene expression index in the rice cultivar indica, we sequenced and analyzed 86,136 ESTs from nine rice cDNA libraries from the super hybrid cultivar LYP9 and its parental cultivars. We assembled these ESTs into 13,232 contigs and leave 8,976 singletons. Overall, 7,497 sequences were found similar to the existing sequences in GenBank and 14,711 are novel. These sequences are classified by molecular function, biological process and pathways according to the Gene Ontology. We compared our sequenced ESTs with the publicly available 95,000 ESTs from japonica, and found little sequence variation, despite the large difference between genome sequences. We then assembled the combined 173,000 rice ESTs for further analysis. Using the pooled ESTs, we compared gene expression in metabolism pathway between rice and Arabidopsis according to KEGG. We further profiled gene expression patterns in different tissues, developmental stages, and in a conditional sterile mutant, after checking the libraries are comparable by means of sequence coverage. We also identified some possible library specific genes and a number of enzymes and transcription factors that contribute to rice development.
文摘Over 3000 rice plants with T-DNA carrying a Ds element were constructed by Agro-bacterium tumefaciens mediation. Using inverse PCR methodology, 590 unique right flanking sequences of T-DNA (Ds) were retrieved from independent transformants and classified into six main types on the basis of the origin of filler DNA between the right border of T-DNA and flanking sequence of rice genome. Type I sequences were the most common and showed canonical in-tegration that T-DNA right border was followed by rice genome sequence with or without filler DNA of no more than 50 bp, while type II sequences displayed a vector-genome combination that T-DNA right border was followed by a vector fragment and then connected with rice genome sequence. The location and distribution of 340 type I and II flanking sequences on the rice chromosome were determined using BLAST analysis. The 340 Ds insertions at an average in-terval of 0.8 megabase (Mb) constructed a basic framework of Ds starter points on whole rice chromosomes. The frequency of T-DNA (Ds) inserted into the exons of predicted genes on chromosome one was 21%. Knowledge of T-DNA (Ds) locations on chromosomes will prove to be a useful resource for isolating rice genes by Ds transposon tagging as these Ds insertions can be used as starting lines for further mutagenesis.
文摘AIM: To explore the properties of hypervariable region 1(HVR1) in the envelope 2 gene of hepatitis C virus by analyzing the reactivity of HVR1 fusion proteins from different Chinese HCV strains with sera of patients with chronic hepatitis C and by comparing their reactivity between interferon therapy responders and non-responders.METHODS: Gene fragments of HVR1 of four HCV strains (three genotype 1b and one genotype 2a) were amplified from pGEMT-E2 plasmids and sub-cloned into pQE40vectors respectively to construct recombinant expression plasmids which expressed HVR1 fused downstream to DHFR in Escherichia coli strain TG1. The purified DHFRHVR1 proteins were then used to detect the anti-HVR1antibodies in 70 serum samples of patients with chronic hepatitis C.RESULTS: Four DHFR- HVR1 fusion proteins were successfully expressed in E.coli (320-800 ug fusion proteins per 100 ml culture). Each fusion protein (SH1b, BJ1b,SD1b and SD2a) reacted with 72.8 % (51/70), 60 % (42/70), 48.6 % (34/70), and 58.6 % (41/70) of the anti-HCV positive patients' sera respectively by ELISA. 57.1% (4/7) of non responders reacted with all four HVR1 fusion proteins, while only 15.3 % (2/13) of responders reacted with all of them. The O.D. values of sera from IFN therapy responders were significantly higher than those of non responders (P＜0.05).CONCLUSION: The selected HVR1 fusion proteins expressed in E. coli can broadly react with HCV-infected patients' sera. The intensity and/or quality of the immune response against HCV may be a critical factor determining the response to interferon treatment. With the evolution of virus strains, anti-HVR1 antibodies can not neutralize all the quasispecies. A polyvalent and high immunogenic vaccine comprising a mixture of several HVR1 sequences that cover the reactivity of most HCV isolates may be useful.
文摘Irradiation-induced impurity segregation to grain boundaries is one of the important radiation effects on materials. For this reason, phosphorus segregation to prior austenite grain boundaries in a P-doped 2.25Cr1Mo steel subjected to neutron irradiation is examined using field emission gun scanning transmission electron microscopy (FEGSTEM) with energy dispersive X-ray microanalysis (EDX). The steel samples are irradiated around 270 and 400℃, respectively. The irradiation dose rate and dose are -1.05×10-8 dpa/s and -0.042 dpa respectively for 270℃ irradiation, and 1.7×10-8 dpa/s and 0.13 dpa respectively for 400℃ irradiation. The FEGSTEM results indicate that there is no apparent phosphorus segregation during 270℃ irradiation but there is some during 400℃ irradiation.
文摘The fluorescence emission and X-ray diffraction of magenesium 8-hydroxyquinoline complex(Mgq2) have been measured at high pressure up to 14 GPa.It has been found that pressure can influence the emission dramatically.At relative lower pressure(less than 2.5GPa) the fluorescence of Mgq2 changes slightly,but the emission drops quickly with increase of the pressure when the pressure gets higher than 2.5GPa.The results of in situ energy dispersive X-ray diffraction at high pressure with synchrotron radiation indicate that there is a phase transition at about 2.5-3GPa for Mgq2 crystal.2001 Elsevier Science B.V.All rights reserved.
基金supported by the National Natural Science Foundation of China,No.A30171086the Knowledge Innovation Program of Chinese Academy of Sciences and the number is KSCX2-SW-202
文摘This study was undertaken to have a better understand for the process and the underlying mechanisms to limit macrophage activation and population of activated macrophages.A comprehensive kinetics of cytokine production was performed in murine peritoneal macrophages recovered from Balb/c mice at various time during the course of an intraperitoneal injection with thioglycollate (TG).The expression of cell surface molecules such as MHC-Ⅰ,MHC-Ⅱ,B7-1 and B7-2 of these macrophages were also determined by flow cytometry.The present findings of our research suggested that the population of activated macrophages and the activation of macrophages (including cytokines production and expression of cell surface functional molecules) were strictly controlled during inflammation process.This is one of the important mechanisms to retain the host homeostasis.Cellular & Molecular Immunology.2004;1(1):57-62.
文摘A high pressure energy dispersive X-ray diffraction apparatus on 3W1A bearmline,at BSRF,is described.A ten-Poles permanent magnetic wiggler provided white X-ray beam.The extreme high pressure up to 115GPa has been obtained by a modified Mao-Bell diamond anvil cell.A motorized loading system with strain sensor can finely control the pressure change.The in situ experimental procedures are described.Some applications are also presented.2001 Elsevier Science B.V.All rights reserved.
文摘Objective To study the effect of hypertension on inducible isoform of nitrogen oxide syn- theses (iNOS) expression and reproductive function in testes of Dahl hypertensive rats Method The iNOS expression in Dahl rat testes was localized and assayed semi-quan- titatively by immunohistochemistry. Results iNOS was expressed and localized predominantly in the cytoplasm of Sertoli and Leydig cells in both normal and hypertensive rats. However, in the early stage of hypertension, the expression of iNOS was stronger in testes than that of the normal rats (P<0.05). With the development, the staining intensity of iNOS decreased gradu- ally in the late stage. Moreover, the level of testosterone decreased with the increase of blood pressure. But in vitro, there was no difference in the expression of iNOS between cultured Sertoli cells from normal rats and hypertensive rats. Conclusion High-salt food induced hypertension in Dahl rats, which was character- ized by the high expression of iNOS in rat Sertoli and Leydig cells; excessive NO produced by iNOS reduced the level of testosterone in testicle artery, and may thus affect the reproductive function of rats testis.
文摘To make it possible for the thermal wave theory on temperature oscillation (TO) effects in living tissues to be founded on the substantial experimental basis, a series of typical decisive experiments in vivo as well as in artificially simulating constructions were carried out. Conclusions obtained including some other scholars' animal experimental results all greatly support the thermal wave viewpoint qualitatively.A few experimental facts used hot to be easily understood from the classical viewpoint are also well reinterpreted. The revealing on the thermal wave mechanisms of TO in living tissues is a brand new discovery and deep insight into this important thermophysiological phenomenon. It may possibly promote new investigations on the corresponding topics in the field of bioheat transfer science.
基金Supported by National High Technology Research and Development Program of China (863 Program), No. 2001AA215171
文摘AIM: To explore the possibility of expressing hepatitis C virus (HCV) envelope protein 1 (E1) in Escherichia coli(E, coli) and to test the purified recombinant E1 proteins for clinical and research applications. METHODS: C-terminally truncated E1 fragments were expressed in E, coli as hexa-histidine-tagged fusion proteins. The expression products were purified under denaturing conditions using immobilized-metal affinity chrbmatography. Purified E1 proteins were used to immunize rabbits. Rabbit anti-sera thus obtained were reacted with both E. coli- and mammalian cell-expressed E1 glycoproteins as detected by Western blot. RESULTS: Full-length E1 protein proved difficult to express in E. coli, C-terminally truncated E1 was successfully expressed in E. coli as hexa-histidine-tagged recombinant fusion protein and was purified under denaturing conditions on Ni2+-NTA agarose. Rabbit anti-sera raised against purified recombinant E1 specifically reacted with mammalian cell-expressed E1 giycoproteins in Western blot. Furthermore, E. coli-derived E1 protein was able to detect animal antibodies elicited by E1-based DNA immunization. CONCLUSION: These results demonstrate that the prokaryotically expressed E1 proteins share identical epitopes with eukaryotically expressed E1 glycoprotein. The E coli-derived E1 proteins and corresponding antisera can become useful tools in anti-HCV vaccine research.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 39893320).
文摘OsEBP-89 is a transcription factor gene of rice. It contains two introns. Using RT-PCR and Southern hybridization to study OsEBP-89 tissue-specific expression, we found that its first intron (115 bp in length) of its was retained in a fraction of its transcripts of this gene in rice developing seeds. Furthermore, two OsEBP-89 cDNA clones (c89L and c89LH) were screened from a rice cDNA library. Sequence analysis revealed that the first intron was retained in c89L clone, whereas, both the first and second intron sequences were spliced in c89LH. In addition to developing seeds, the first intron unspliced transcripts of OsEBP-89 are detected in leaves and roots of rice, too. However, the ratio of the first intron unspliced to spliced OsEBP-89 transcripts varied in different tissues examined. The potential biological significance of intron retention in OsEBP-89 transcript was discussed.
