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Li F, Li LY. An equation characterizing multi-heavy-metal sorption onto bentonite, forest soil and spruce bark. ENVIRONMENTAL TECHNOLOGY 2003; 24:1479-1490. [PMID: 14977144 DOI: 10.1080/09593330309385693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
An empirical equation was developed to quantitatively describe heavy metal sorption in ternary systems of lead (Pb), copper (Cu) and cadmium (Cd). The three sorbants investigated were bentonite, forest soil and spruce bark. This multi-sorption equation is based on three assumptions: the relationship between sorption and initial heavy metal concentration fits a power curve; the presence of one heavy metal proportionately reduces the sorption curve of another heavy metal; and the competition between two heavy metals is independent of the presence of other heavy metals. The multi-sorption equation modeled sorption in ternary systems to a regression fit greater than 0.96. The data required for the equation were generated from a technically straightforward and quick laboratory program involving batch adsorption tests.
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77
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Li LY. [Pathological changes and host tissue reaction in alveolar echinococcosis]. ZHONGGUO JI SHENG CHONG XUE YU JI SHENG CHONG BING ZA ZHI = CHINESE JOURNAL OF PARASITOLOGY & PARASITIC DISEASES 2003; 19:109. [PMID: 12572000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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78
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Taniguchi E, Nakajima H, Hongyo T, Fukuda K, Li LY, Kurooka M, Matsuda H, Nomura T. Effects of N-methyl-N'-nitro-N-nitrosoguanidine on the human colorectal polyps consecutively maintained in SCID mice. Cancer Lett 2002; 182:127-33. [PMID: 12048157 DOI: 10.1016/s0304-3835(02)00099-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
N-Methyl-N'-nitro-N-nitrosoguanidine (MNNG) treatments for a long period induced morphological and molecular alterations in the benign human colorectal polyps which were maintained in the severe combined immunodeficient C.B17/N-scid/scid mice. Thirty four xenografts of colorectal polyps from five solitary polyp and three familial polyposis patients were examined for K-ras and p53 mutations. Six K-ras mutations were induced in 16 grafts treated with MNNG more than five times, while no K-ras mutations were detected in 14 untreated grafts (P<0.05). Additional and new K-ras mutations were also induced in two polyps in which K-ras mutation had pre-existed. p53 mutations were not observed in both MNNG-treated and untreated groups. The mutations in K-ras gene were induced at codon 12 (GGT-->GAT) except one at codon 13 (GGC-->GGT). The results indicate that K-ras mutation plays an important role in human colorectal carcinogenesis as is the case in experimental animals.
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79
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Wang YR, Ren HW, An L, Fang M, Li LY, Ru BG. Expression of Human Trefoil Factor 3 in Pichia pastoris and Its Biological Activity Analysis. SHENG WU HUA XUE YU SHENG WU WU LI XUE BAO ACTA BIOCHIMICA ET BIOPHYSICA SINICA 2002; 33:653-658. [PMID: 12035057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
The human TFF3 (trefoil factor 3) DNA fragment was amplified by polymerase chain reaction (PCR) from human fetal placenta cDNA. The gene was cloned into the Pichia pastoris expression vector pPIC9K containing AOX 1 promoter and alpha-factor leader sequence. Multi-copies insertion transformants were screened on G418 plates. After the induction by 2% methanol for 48 hours, the expression of dimeric hTFF3 came up to 45% of total proteins in medium, as identified by SDS-PAGE and Western blot assay. The recombinant protein was further purified by S-Sepharose, Q-Sepharose ion-exchange chromatography and Sephacryl-S-100 gel filtration chromatography to the 95% purity, as shown by densitometric scanning. The N-terminus and molecular weight of the recombinant hTFF3 was in good agreement with the native hTFF3. The recombinant protein was proved to have good biological activity of preventing rats from the gastric ulcer induced by hydrochloric acid.
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80
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Liu SF, Li LY, Fu JJ, Liu G, Xing XW, Lu GX. [Rapid identification of human testis spermatocyte apoptosis-related gene, TSARG2, by nested PCR and draft human genome searching]. SHENG WU HUA XUE YU SHENG WU WU LI XUE BAO ACTA BIOCHIMICA ET BIOPHYSICA SINICA 2002; 34:378-82. [PMID: 12019456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Cloning apoptosis-related novel genes is a key to further understanding of apoptosis mechanism and the biology process of germ cells, and is of momentous significance on clarifying physiological and pathological process of spermatogenesis. To rapidly attain human novel gene full-length cDNA sequence, the gene-specific primers and the vector-specific primers were designed for nested PCR, and draft human genome searching was performed to rapidly identify the TSARG2 (GenBank accession number AY040204) 5' end from a human testis cDNA library, by using a cDNA fragment (GenBank accession number BE644542) as an electronic probe, which was significantly changed in cryptorchidism and represented a novel gene. Furthermore, a mouse homologue of this gene was identified (GenBank accession number AF395083) by lab on-line. TSARG2 with a 1 233 bp length was composed of 6 exons and spanned about 115 kb of genomic DNA, The putative protein encoded by this gene was 305 amino acid with a theoretical molecular weight of 34 751 dalton and did not share significant homology with any known protein in databases. TSARG2 was expressed in many tissues and mapped to chromosome 4q33-34.1 by database analyses. Therefore, we propose that nested-PCR and draft human genome searching are rapid, sensitive, accurate and efficient method for isolating gene 5' end, even full-length gene from cDNA library.
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81
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Widlak P, Li LY, Wang X, Garrard WT. Action of recombinant human apoptotic endonuclease G on naked DNA and chromatin substrates: cooperation with exonuclease and DNase I. J Biol Chem 2001; 276:48404-9. [PMID: 11606588 DOI: 10.1074/jbc.m108461200] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Endonuclease G (endoG) is released from mitochondria during apoptosis and is in part responsible for internucleosomal DNA cleavage. Here we report the action of the purified human recombinant form of this endonuclease on naked DNA and chromatin substrates. The addition of the protein to isolated nuclei from non-apoptotic cells first induces higher order chromatin cleavage into DNA fragments > or = 50 kb in length, followed by inter- and intranucleosomal DNA cleavages with products possessing significant internal single-stranded nicks spaced at nucleosomal ( approximately 190 bases) and subnucleosomal ( approximately 10 bases) periodicities. We demonstrate that both exonucleases and DNase I stimulate the ability of endoG to generate double-stranded DNA cleavage products at physiological ionic strengths, suggesting that these activities work in concert with endoG in apoptotic cells to ensure efficient DNA breakdown.
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82
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Yu J, Tian S, Metheny-Barlow L, Chew LJ, Hayes AJ, Pan H, Yu GL, Li LY. Modulation of endothelial cell growth arrest and apoptosis by vascular endothelial growth inhibitor. Circ Res 2001; 89:1161-7. [PMID: 11739281 DOI: 10.1161/hh2401.101909] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Vascular endothelial growth inhibitor (VEGI), a new member of the tumor necrosis factor family, is an endothelial cell-specific gene and a potent inhibitor of endothelial cell proliferation, angiogenesis, and tumor growth. We report here that VEGI mediates the following two activities in endothelial cells: early G(1) arrest in G(0)/G(1) cells responding to growth stimuli, and programmed death in proliferating cells. G(0)/G(1)-synchronized bovine aortic endothelial cells were treated with VEGI before and after the onset of the growth cycle. When the cells were stimulated with growth conditions but treated simultaneously with VEGI, a reversible, early-G(1) growth arrest occurred, evidenced by the lack of late G(1) markers such as hyperphosphorylation of the retinoblastoma gene product and upregulation of the c-myc gene. Additionally, VEGI treatment led to inhibition of the activities of cyclin-dependent kinases CDK2, CDK4, and CDK6. In contrast, VEGI treatment of cells that had entered the growth cycle resulted in apoptotic cell death, as evidenced by terminal deoxytransferase labeling of fragmented DNA, caspase 3 activation, and annexin V staining, all of which were lacking in nonproliferating cells treated with VEGI. Additionally, stress-signaling proteins p38 and JNK were not as fully activated by VEGI in quiescent as compared with proliferating populations. These findings suggest a dual role for VEGI, the maintenance of growth arrest and induction of apoptosis, in the modulation of the endothelial cell cycle.
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83
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Li LY, Ciren BZ, Zhan D, Wei YF. [Comprehensive utilization and development of traditional Tibetan medicine in China]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 2001; 26:808-10. [PMID: 12776325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
OBJECTIVE To deal with the further investigation field by discussing the status and present problem of traditional Tibetan medicine. METHOD Previous relevant investigations and literatures were summed up in the field. The present situation of traditional Tibetan medicine in China was analysed. RESULT The textual research, basic medicinal property, exploration of developable medicinal resource and protection of endangered medicinal species etc. were elaborated and the key problem of further investigation in 21st century was expounded. CONCLUSION The textual research, basic medicinal property, exploration of develoable medicinal resources, especially monographic study on protection of major endangered medicinal resources should be intensified. Domestication and cultivation, and exploration of good-quality medicinal resources, quality evaluation and exploitation of effectual prescriptions are the focal field in the study of traditional Tibetan medicine.
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Wang YR, Fang M, An L, Li LY, Ru BG. [Studies on the expression condition of human trefoil factor 3 in Pichia pastoris]. SHENG WU GONG CHENG XUE BAO = CHINESE JOURNAL OF BIOTECHNOLOGY 2001; 17:648-51. [PMID: 11910758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
In order to enhance the expression level of human trefoil factor 3 (hTFF3) in Pichia pastoris, we optimized the transformant growth conditions in shake flasks including carbon sources in growth medium, inoculation ratio, methanol concentration, pH rotation speed and inducing time. The transformant could grow on the glucose to OD600 5.0 after 14 hours inoculation. The best inoculation ration of 100 mL growth medium to the induction medium was 1:1. The expression level of dimeric human trefoil factor 3 induction with 1% methanol for 48 hours at pH 6.0, agitation speed 240 r/min could reach 20 mg/L with OD600 15. The protein was expressed in 5-liter fermentor with 2% methanol induction for 32 hours, finally the cell density reached OD600 120. 100 mg/L of recombinant hTFF3 was obtained in the supernatant.
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85
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La Spada AR, Fu YH, Sopher BL, Libby RT, Wang X, Li LY, Einum DD, Huang J, Possin DE, Smith AC, Martinez RA, Koszdin KL, Treuting PM, Ware CB, Hurley JB, Ptácek LJ, Chen S. Polyglutamine-expanded ataxin-7 antagonizes CRX function and induces cone-rod dystrophy in a mouse model of SCA7. Neuron 2001; 31:913-27. [PMID: 11580893 DOI: 10.1016/s0896-6273(01)00422-6] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant disorder caused by a CAG repeat expansion. To determine the mechanism of neurotoxicity, we produced transgenic mice and observed a cone-rod dystrophy. Nuclear inclusions were present, suggesting that the disease pathway involves the nucleus. When yeast two-hybrid assays indicated that cone-rod homeobox protein (CRX) interacts with ataxin-7, we performed further studies to assess this interaction. We found that ataxin-7 and CRX colocalize and coimmunoprecipitate. We observed that polyglutamine-expanded ataxin-7 can dramatically suppress CRX transactivation. In SCA7 transgenic mice, electrophoretic mobility shift assays indicated reduced CRX binding activity, while RT-PCR analysis detected reductions in CRX-regulated genes. Our results suggest that CRX transcription interference accounts for the retinal degeneration in SCA7 and thus may provide an explanation for how cell-type specificity is achieved in this polyglutamine repeat disease.
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86
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Kong LJ, Li LY, Tang ZF. [Clinical study on relationship of CD62p, CD63 and TSP to the qi-stagnation induced blood-stasis syndrome and qi-deficiency induced blood-stasis syndrome in aged patients]. ZHONGGUO ZHONG XI YI JIE HE ZA ZHI ZHONGGUO ZHONGXIYI JIEHE ZAZHI = CHINESE JOURNAL OF INTEGRATED TRADITIONAL AND WESTERN MEDICINE 2001; 21:588-90. [PMID: 12575572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To observe the relationship of platelet activation to the Qi-stagnation induced blood-stasis (QSBS) or Qi-deficiency induced blood-stasis (QDBS) syndrome. METHODS Expressions of platelet activating molecules, including alpha-granule membrane glycoprotein (CD62p), lysosomal integral membrane protein (CD63) and thrombospondin (TSP), in patients with QSBS and QDBS were determined quantitatively with flow-cytometry and specific monoclonal antibody against activated platelet. And platelet aggregation was tested simultaneously. RESULTS CD62p, CD63 and TSP expressions in Blood-Stasis patients, both QSBS and QDBS, were higher than those in the normal control significantly (all P < 0.01); all the three expressions were higher in QSBS group than those in QDBS group (all P < 0.01), Positive correlation was shown between CD62p and CD63 (r = 0.740, P < 0.01), CD62p and TSP (r = 0.744, P < 0.01), TSP and CD63 (r = 0.635, P < 0.01), and between CD62p and ADP induced platelet aggregation (r = 0.715, P < 0.01). CONCLUSION Platelet activation was involved in the pathogenesis and development of Blood-Stasis Syndrome, especially closely related with the QSBS Syndrome.
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87
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Zhu ZH, Zhou Q, Li LY, Cui RX, Cheng WY, Li YF. [Evaluation of positron emission tomography in diagnosing and staging of lung cancer]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 2001; 23:365-8. [PMID: 12940078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
OBJECTIVE To evaluate positron emission tomography (PET) in diagnosing and staging of lung cancer. METHODS One hundred and forty-seven patients (93 with lung cancer, 15 with lung metastatic tumors, 39 with benign lesions) were involved in the study. 163 whole body examinations (twice in 12 cases and 3 times in 2 cases) were performed after injection of 18F-fluro-deoxy-glucose (18FDG) with a Siemens ECAT EXACT HR + PET system. The results of PET were compared with pathological diagnoses (112 cases), clinical follow-up (35 cases), CT (68 malignant and 30 benign cases), and other imaging diagnoses. RESULTS For the 147 cases with lung lesions, the sensitivity, specificity, and accuracy of FDG PET in differentiating the malignant from the benign were 97.2%, 89.7%, and 94.6% respectively. For the 93 lung cancer cases, more lesions were detected by PET in 58 (62.4%) cases, and changed staging in 36 (38.7%). In the 98 cases examinations, PET positive findings were consistent with CT in 39 (39.8%) cases; PET detected more lesions than CT in 29 (29.6%) cases; the lesions detected by CT were negative or with low uptake in the PET images in 30 (30.6%) cases, and they were finally proved as benign by follow-up. However, CT provided better detailed anatomical structures of the lesions than PET, and image fusion should give more information about the lesions. CONCLUSIONS FDG PET had advantages in diagnosing and staging of lung cancer by providing metabolic information of the lesions. Comparison and fusion of PET with CT will give much help to clinical diagnosis.
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88
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Lu J, Lu WW, Tian JM, Li LY. [Effect of Rg2 on hemodynamics of hemorrhagic shock and its antioxidation in dogs]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 2001; 26:556-8. [PMID: 12776372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
OBJECTIVE To investigate the protective effect of Rg2 on hemodynamics of hemorrhagic shock and its antioxidant properties. METHOD Twenty mongrel dogs were randomly divided into Rg2 group, Shen Mai group and control group. The hemorrhagic shock model was built in all dogs by artery bleeding and mean arterial blood pressure was kept < 5.33 kPa for 4.5 hours. Rg2 0.5-1.0 mg.kg-1 and Shen Mai 100 mg.kg-1 were intravenously administered after hemorrhagic shock appeared. RESULT Rg2 significantly enhanced blood pressure, LVSP and +/- dp/dtmax on hemorrhagic shock dogs who had lost compensation ability. Rg2 0.5-1.0 mg.kg-1 could reduce serum MDA, increase superoxide dismutase activity and prolong survival rate of dogs after shock. All these data have statistically significant when compared to control group (P < 0.05, P < 0.01, P < 0.001). CONCLUSION These results suggest that Rg2 is more potent and effective than Shen Mai in improving hemodynamic state and activiting SOD on hemorrhagic shock dogs.
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Abstract
Nucleosomal fragmentation of DNA is a hallmark of apoptosis (programmed cell death), and results from the activation of nucleases in cells undergoing apoptosis. One such nuclease, DNA fragmentation factor (DFF, a caspase-activated deoxyribonuclease (CAD) and its inhibitor (ICAD)), is capable of inducing DNA fragmentation and chromatin condensation after cleavage by caspase-3 (refs 2,3,4). However, although transgenic mice lacking DFF45 or its caspase cleavage site have significantly reduced DNA fragmentation, these mice still show residual DNA fragmentation and are phenotypically normal. Here we report the identification and characterization of another nuclease that is specifically activated by apoptotic stimuli and is able to induce nucleosomal fragmentation of DNA in fibroblast cells from embryonic mice lacking DFF. This nuclease is endonuclease G (endoG), a mitochondrion-specific nuclease that translocates to the nucleus during apoptosis. Once released from mitochondria, endoG cleaves chromatin DNA into nucleosomal fragments independently of caspases. Therefore, endoG represents a caspase-independent apoptotic pathway initiated from the mitochondria.
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Li LY, Shih HM, Liu MY, Chen JY. The Cellular Protein PRA1 Modulates the Anti-apoptotic Activity of Epstein-Barr Virus BHRF1, a Homologue of Bcl-2, through Direct Interaction. J Biol Chem 2001; 276:27354-62. [PMID: 11373297 DOI: 10.1074/jbc.m103821200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Epstein-Barr virus-encoded early protein, BHRF1, is a structural and functional homologue of the anti-apoptotic protein, Bcl-2. There is accumulating evidence that BHRF1 protects a variety of cell types from apoptosis induced by various external stimuli. To identify specific proteins from normal epithelial cells that interact with BHRF1 and that might promote or inhibit its anti-apoptotic activity, we screened a yeast two-hybrid cDNA library derived from human normal foreskin keratinocytes and identified a cellular gene encoding human prenylated rab acceptor 1 (hPRA1). The interaction of hPRA1 with BHRF1 was confirmed using glutathione S-transferase pull-down assays, confocal laser scanning microscopy, and co-immunoprecipitation. Two regions of PRA1, amino acids 30-53 and the carboxyl-terminal 21 residues, are important for BHRF1 interactions and two regions of BHRF1, amino acids 1-18 and 89-142, including the Bcl-2 homology domains BH4 and BH1, respectively, are crucial for PRA1 interactions. PRA1 expression interferes with the anti-apoptotic activity of BHRF1, although not of Bcl-2. These results indicate that the PRA1 interacts selectively with BHRF1 to reduce its anti-apoptotic activity and might play a role in the impeding completion of virus maturation.
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91
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Tezel G, Li LY, Patil RV, Wax MB. TNF-alpha and TNF-alpha receptor-1 in the retina of normal and glaucomatous eyes. Invest Ophthalmol Vis Sci 2001; 42:1787-94. [PMID: 11431443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
PURPOSE To determine the expression and localization of tumor necrosis factor (TNF)-alpha and TNF-alpha receptor-1 in the retina of normal and glaucomatous eyes. METHODS Using immunohistochemistry and in situ hybridization, retinal expression and localization of TNF-alpha and TNF-alpha receptor-1 were studied in retina sections from 20 eyes of donors with glaucoma, and 20 eyes of age-matched normal donors. RESULTS According to immunohistochemistry, the intensity of the immunostaining and the number of labeled cells for TNF-alpha or its receptor were greater in retina sections of glaucomatous eyes than in control eyes of age-matched normal donors. In situ hybridization showed that mRNA signals for TNF-alpha or TNF-alpha receptor-1 were similarly more intense in glaucomatous eyes than in age-matched control eyes. Both protein and mRNA of TNF-alpha or TNF-alpha receptor-1 were predominantly localized to the inner retinal layers. Double-immunofluorescence labeling demonstrated that retinal immunostaining for TNF-alpha was predominantly positive in the glial cells, whereas immunostaining for TNF-alpha receptor-1 was mainly positive in the retinal ganglion cells. CONCLUSIONS Upregulation of TNF-alpha and its receptor-1 in glaucomatous retina suggest that TNF-alpha-mediated cell death is involved in the neurodegeneration process of glaucoma.
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Liu B, Li LY, Pang ZL. [The expression and biological effects of stem cell factor and its receptor in nervous system]. SHENG LI KE XUE JIN ZHAN [PROGRESS IN PHYSIOLOGY] 2001; 32:143-5. [PMID: 12545886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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93
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Li LY. A study of iron mineral transformation to reduce red mud tailings. WASTE MANAGEMENT (NEW YORK, N.Y.) 2001; 21:525-534. [PMID: 11478619 DOI: 10.1016/s0956-053x(00)00107-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This study examines the effects of iron mineral transformation in an aluminum extraction process on the settling behavior, and the physical and chemical properties of the resulting red mud slurry that must be disposed of. By producing a red mud with a higher solid content, the total volume of mud slurry will also be reduced for a given alumina production rate and more caustic soda will be recovered. The settling behavior and the mineralogical, physical, and physico-chemical properties of one bauxite and three red muds processed under varying conditions were analyzed based on examination of the iron mineral transformations. The properties of red muds derived from the same bauxite can differ markedly due to variations in operating conditions of the Bayer process, such as temperature and the addition of a reducing agent. The settling of red mud can be improved by converting goethite into hematite and/or magnetite to produce a mud of larger particle size, smaller specific surface area, and larger specific gravity, characteristics which reduce the total volume of mud slurry to be disposed of and which allow for less potential contamination from caustic soda. This study also found that the by-product--Bayer sodalite--has the high exchange capacity for Na+ that might contribute to the long-term environmental problems.
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Gong GZ, Ding Q, Zheng XH, Li LY, Lai LY, Huang L. [Relationship between hot spot mutation in hepatitis B virus basic core promotor and HBeAg status]. HUNAN YI KE DA XUE XUE BAO = HUNAN YIKE DAXUE XUEBAO = BULLETIN OF HUNAN MEDICAL UNIVERSITY 2000; 25:561-3. [PMID: 12516404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE This paper was to study the influence of hot spot mutation in hepatitis B virus (HBV) basic core promotor (BCP) (nt1762 and nt1764) on HBeAg status of asymptomatic HBV carriers. METHODS Mismatched PCR was used to amplify the fragment of HBVBCP and the fragments were analysed by restrict enzyme assay. Ninety cases of HBV infection were tested for hot spot mutations in HBVBCP. RESULTS Twenty-six (43.3%) of 60 asymptomatic HBV carriers with HBeAg negative were found to have hot spot mutations in HBVBCP, among which 20 cases were accompanied by the mutation of nt 1896 in HBV Pre-C region. Hot-spot mutation in HBVBCP, however, occurred only in 3(10%) of 30 asymptomatic HBV carriers with HBeAg positive. For further investigation the HBVBCP hot spot mutations in asymptomatic HBV carriers without mutation of HBV Pre-C region were studied. Six(31.6%) of 19 asymptomatic HBV carriers with HBeAg negative were found to have hot spot mutation in HBVBCP. Two(7.1%) of 28 asymptomatic HBV carriers with HBeAg positive had hot spot mutations in HBVBCP, and there was a statistically significant difference between two groups. CONCLUSIONS Hot spot mutations in HBVBCP is common in the HBV carriers with HBeAg negative and usually accompanies with nt1896 mutation of HBV Pre-C region. It is possible that Hot spot mutation in HBVBCP is a new reason of HBeAg negative HBV infection.
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Hayes AJ, Huang WQ, Yu J, Maisonpierre PC, Liu A, Kern FG, Lippman ME, McLeskey SW, Li LY. Expression and function of angiopoietin-1 in breast cancer. Br J Cancer 2000; 83:1154-60. [PMID: 11027428 PMCID: PMC2363588 DOI: 10.1054/bjoc.2000.1437] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Angiopoietin-1 (Ang1) has been shown to act as an angiogenic promoter in embryonic angiogenesis by promoting vascular branching, pericyte recruitment and endothelial survival. We have investigated the role of Ang1 in tumour neovascularization under clinical conditions and in animal models. The expression of Ang1 in clinical breast cancer specimens was analysed by using laser-capture microdissection and reverse transcriptase-linked polymerase chain reaction (RT-PCR) on RNA isolated from the samples. Despite the expression of Ang1 in many human breast cancer cell lines, the gene was expressed in only three of 21 breast cancer clinical specimens, even though its receptor, Tie2, is abundant in the vasculature of all of these tumours. Ang1 was then overexpressed in a human breast cancer cell line (MCF-7) on its own and in conjunction with FGF1, an angiogenic factor shown to be able to increase the tumorigenicity of MCF-7 cells. High concentrations of Ang1 were produced in the conditioned media of the transfected cells (range 156-820 ng ml(-1)). However, in contrast to its physiological role as promoter of angiogenesis, overexpression of Ang1 did not enhance tumour growth, but instead caused up to a 3-fold retardation of tumour growth (P = 0.003).
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MESH Headings
- Angiopoietin-1
- Animals
- Breast Neoplasms/genetics
- Breast Neoplasms/pathology
- CHO Cells
- Cell Division/genetics
- Cricetinae
- Culture Media, Conditioned/chemistry
- Culture Media, Conditioned/metabolism
- DNA, Complementary/genetics
- Female
- Fibroblast Growth Factor 1
- Fibroblast Growth Factor 2/genetics
- Gene Expression Regulation, Neoplastic
- Humans
- Mammary Neoplasms, Experimental/genetics
- Mammary Neoplasms, Experimental/pathology
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/physiology
- Mice
- Mice, Nude
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Transfection
- Transplantation, Heterologous
- Tumor Cells, Cultured
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96
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Li LY, Stewart BH, Fleisher D. Oral delivery of HIV-protease inhibitors. Crit Rev Ther Drug Carrier Syst 2000; 17:73-99. [PMID: 10820645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Strategies for optimizing the oral delivery of HIV-protease inhibitors draw from drug discovery efforts in molecular design, drug development tools in dosage formulation, and dosage regimen considerations in clinical medicine. This review outlines the evolution of these strategies for drugs that have been approved for human use, drug candidates still in development, and molecules that are no longer in development but from which valuable delivery information was obtained. Molecular design for obtaining desirable pharmacokinetics following oral administration primarily involved maximizing aqueous solubility and minimizing first-pass metabolism. Optimization of molecular design for oral drug delivery purposes is tempered by additional considerations for drug potency, toxicity, potential for interactions, and development of viral resistance. Strategies for improving oral bioavailability through dosage formulation use information from the effects of coadministered meals on drug plasma levels. Patient adherence to dosage regimens remains a major issue in assuring effective oral drug treatment and in preventing the development of resistance. Progress has been made in clinical studies where improved oral bioavailability and reductions in drug plasma level variability have been achieved with appropriate dosage regimen adjustment.
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Liu MY, Shih YY, Li LY, Chou SP, Sheen TS, Chen CL, Yang CS, Chen JY. Expression of the Epstein-Barr virus BHRF1 gene, a homologue of Bcl-2, in nasopharyngeal carcinoma tissue. J Med Virol 2000; 61:241-50. [PMID: 10797381 DOI: 10.1002/(sici)1096-9071(200006)61:2<241::aid-jmv11>3.0.co;2-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Epstein-Barr virus (EBV) infection is associated closely with the pathogenesis of nasopharyngeal carcinoma (NPC). The EBV gene product, BHRF1, has been demonstrated in vitro and is structurally and functionally similar to the oncogene bcl-2, that is able to protect cells from programmed cell death. To determine whether the BHRF1 gene is expressed in vivo, BHRF1 mRNA or protein were sought in tissues from NPC and non-NPC patients. BHRF1 transcripts were specifically detected in the NPC tumours (32 out of 44, 72.7%) rather than the non-NPC tissues (0 out of 25) by reverse transcription, polymerase chain reaction and Southern hybridization. Other EBV genes, such as the lytic gene BZLF1 and latent genes EBNA1 and LMP2A, were also investigated. BZLF1 transcripts also were found specifically in NPC tumours (33 out of 44, 75%). EBNA1 was expressed in 79.5% of NPC, and 28% of non- NPC, tissues and LMP2A was expressed in 70.5% of NPC, and 88% of non-NPC, tissues. BHRF1 protein was detected by immunohistochemistry in 4 metastatic NPC, of 36 NPC tissue sections available. The BHRF1 protein was distributed in both the nucleus and cytoplasm of the neoplastic epithelial cells. IgG antibody against the BHRF1 protein was detected in 6 of 17 (35. 3%) NPC plasma, but the protein and IgG were both absent from the non-NPC controls. BHRF1 DNA sequences were determined for 11 NPC and 3 non-NPC samples. No sequence was specific for the EBV isolates from NPC tissue. Amino acids 79 and 88 always appeared in the same form, however, for every tested isolate and both were valine or leucine. This particular characteristic was not present in the B95-8 strain or in the corresponding regions of homologues, Bcl-2 and Bcl-XL, and was regarded as unique to Oriental EBV strains.
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Li M, Li LY, Wu X, Liang SP. Cloning and functional expression of a synthetic gene encoding huwentoxin-I, a neurotoxin from the Chinese bird spider (Selenocosmia huwena). Toxicon 2000; 38:153-62. [PMID: 10665797 DOI: 10.1016/s0041-0101(99)00123-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Cloning and functional expression of a synthetic gene encoding huwentoxin-I, a neurotoxin from the Chinese bird spider Selenocosmia huwena. A gene encoding huwentoxin-I, a peptide neurotoxin consisted of 33 amino acid residues from the venom of the Chinese bird spider Selenocosmia huwena, was designed, synthesized and expressed in Escherichia coli as a hybrid protein fused with glutathione S-transferase at the N-terminal. The fusion protein was purified by GSH-Sepharose 4B affinity column chromatography and cleaved by thrombin to release the toxin peptide. The amino acid sequence of the recombinant toxin was consistent with the designed one by sequence determination and MALDI-TOF mass analysis, suggesting that the recombinant huwentoxin-I produced the same expression product as the native one. After reduction and renaturation, the biological activity of the recombinant toxin was identical with that of the native huwentoxin-I by electrophysiological method.
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Hayes AJ, Huang WQ, Mallah J, Yang D, Lippman ME, Li LY. Angiopoietin-1 and its receptor Tie-2 participate in the regulation of capillary-like tubule formation and survival of endothelial cells. Microvasc Res 1999; 58:224-37. [PMID: 10527766 DOI: 10.1006/mvre.1999.2179] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Angiopoietin-1 (Ang-1) and its receptor Tie-2, a trans-membrane tyrosine kinase uniquely expressed by endothelial cells, are shown by null mutation studies to be essential to developmental angiogenesis. The phenotypic abnormalities in these knockout animals suggest that Tie-2 signaling is necessary for the maintenance and expansion of the primitive capillary network. We present in vitro evidence indicating that the Ang-1/Tie-2 system participates in the regulation of capillary tubule formation and is necessary for the survival of confluent endothelial cells. Although recombinant Ang-1, which induces Tie-2 phosphorylation, has no effect on the proliferation of endothelial cells, treatment of confluent adult bovine aortic endothelial cells (ABAE) cells grown on collagen gels with Ang-1 (100 ng/ml) causes the cells to migrate into the collagen gel and form capillary-like tubules. The tubule-forming effect of Ang-1 is similar to the effect caused by FGF-2. A soluble form of the Tie-2 extracellular domain, in fivefold molar excess, blocks Ang-1-induced tubule formation. Specific elimination of Tie-2 protein expression in cultured ABAE cells as a result of transfection with an antisense oligonucleotide causes cell death in a dose-dependent manner (IC(50) = 50 nM). The antisense treatment has no effect on cells that do not express Tie-2. Cells treated with antisense oligonucleotide show a sixfold increase in the rate of apoptosis as assessed by in situ end labeling of fragmented DNA. These findings are consistent with the view that Ang-1/Tie-2 signaling is essential for both angiogenesis and endothelial cell survival.
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Li LY, Kelkar P, Exconde RE, Day J, Parry GJ. Adult-onset "infant" botulism: an unusual cause of weakness in the intensive care unit. Neurology 1999; 53:891. [PMID: 10489068 DOI: 10.1212/wnl.53.4.891] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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