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Huang YM, Hussien Y, Yarilin D, Xiao BG, Liu YJ, Link H. Interferon-beta induces the development of type 2 dendritic cells. Cytokine 2001; 13:264-71. [PMID: 11243704 DOI: 10.1006/cyto.2000.0835] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Suppression of interleukin 12 (IL-12) production by dendritic cells (DCs) has been hypothesized to be a principal mechanism underlying the biological action of interferon (IFN)-beta used for treatment of multiple sclerosis (MS), a chronic inflammatory disease of the central nervous system with possible autoimmune origin. How IFN-beta interacts with DCs to inhibit IL-12 production remains unclear. In this study, we found that DCs derived from human blood monocytes, upon culture in the presence of IFN-beta with granulocyte-macrophage colony- stimulating factor (GM-CSF) and IL-4, differentiated into a population expressing CD14- CD1a- HLA-DR+. This population expressed CD123 (IL-3Ralpha). IFN-beta dose-dependently increased IL-3Ralpha+ DCs and decreased CD1a+ DCs. After 7 days' culture with IFN-beta at a concentration of 10 000 U/ml, more than 40% of DCs expressed IL-3Ralpha. IFN-beta, together with GM-CSF and IL-4, also induced maturation of IL-3Ralpha-expressing cells, as reflected by upregulation of HLA-DR and of the costimulatory molecules CD40, CD80 and CD86. In contrast to control DCs, IFN-beta-treated DCs produced predominantly IL-10 but only low levels of IL-12p40. Correspondingly, IFN-beta-treated DCs strongly suppressed IFN-gamma production but enhanced IL-10 production by allogeneic blood mononuclear cells. Our data suggest that IFN-beta in vitro can induce the development of DC2, which provide a permissive environment for Th2 differentiation. This finding represents a novel mechanism for action of IFN-beta in MS.
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152
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Liu YJ, Kadowaki N, Rissoan MC, Soumelis V. T cell activation and polarization by DC1 and DC2. Curr Top Microbiol Immunol 2001; 251:149-59. [PMID: 11036770 DOI: 10.1007/978-3-642-57276-0_19] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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153
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Kadowaki N, Antonenko S, Liu YJ. Distinct CpG DNA and polyinosinic-polycytidylic acid double-stranded RNA, respectively, stimulate CD11c- type 2 dendritic cell precursors and CD11c+ dendritic cells to produce type I IFN. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:2291-5. [PMID: 11160284 DOI: 10.4049/jimmunol.166.4.2291] [Citation(s) in RCA: 219] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Two classes of nucleic acids, bacterial DNA containing unmethylated CpG motifs and dsRNA in viruses, induce the production of type I IFN that contributes to the immunostimulatory effects of these microbial molecules. Thus, it is important to determine which cells produce type I IFN in response to CpG DNA and dsRNA. CD4(+)CD11c(-) type 2 dendritic cell precursors (pre-DC2) were identified as the main producers of type I IFN in human blood in response to viruses. Here we asked whether pre-DC2 also produce type I IFN in response to CpG DNA and dsRNA. Oligodeoxynucleotides containing particular palindromic CpG motifs induced pre-DC2, but not CD11c(+) blood DC or monocytes, to produce IFN-alpha. In contrast, a synthetic dsRNA, polyinosinic polycytidylic-acid, induced CD11c(+) DC, but not pre-DC2 or monocytes, to produce IFN-alphabeta. These data indicate that CpG DNA and polyinosinic-polycytidylic acid stimulate different types of cells to produce type I IFN and that it is important to select oligodeoxynucleotides containing particular CpG motifs to induce pre-DC2 to produce type I IFN, which may play a key role in the strong adjuvant effects of CpG DNA.
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154
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Zhu LZ, Liu YJ. Survey of polycyclic aromatic hydrocarbons (PAHs) in arterial street air of Hangzhou. J Environ Sci (China) 2001; 13:8-13. [PMID: 11590725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The presence of particulate and vapor PAHs, SO2 and NOx and other interrelated conditions (temperature, traffic intensity and wind velocity) were investigated in the arterial street air of Hangzhou. The concentration of the nine PAHs in the air was mean to 11.7 micrograms/m3, and the content of benzo(a) pyrene was up to 0.108 microgram/m3. The contents of PAHs in the sampling sites were in good relation to the traffic intensity, and would be also affected by the terrain and meteorological conditions. The occurrences of PAHs in ambient air were mainly affected by their physical, chemical characters and temperature. The three- and four-ring PAHs (MW < or = 228) mainly existed in the vapor phase and the five-ring PAHs (MW > 228) existed predominately in the particulate phase. The fraction of vapor PAHs in the total nine PAHs was 84.2% in the air of the sampling sites. In the morning and evening, the concentrations of PAHs in the arterial street air were higher than that on the noon and the diurnal variation of PAHs was similar to that of the traffic gas NOx. A conclusion would be drawn that the major source of PAHs in the arterial street air was the traffic. And the results indicated that 75% of BaP would come from traffic source and remaining 25% of BaP would come from non-traffic source.
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155
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Castro AG, Neighbors M, Hurst SD, Zonin F, Silva RA, Murphy E, Liu YJ, O'Garra A. Anti-interleukin 10 receptor monoclonal antibody is an adjuvant for T helper cell type 1 responses to soluble antigen only in the presence of lipopolysaccharide. J Exp Med 2000; 192:1529-34. [PMID: 11085755 PMCID: PMC2193194 DOI: 10.1084/jem.192.10.1529] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Soluble foreign antigen usually leads to a transient clonal expansion of antigen-specific T cells followed by the deletion and/or functional inactivation of the cells. As interleukin (IL)-10 is a key immunoregulatory cytokine, we questioned whether neutralization of IL-10 during priming with soluble antigen could prime for a subsequent T helper cell type 1 (Th1) effector recall response. By using an adoptive transfer model to track the fate of antigen-specific T cell receptor (TCR)-transgenic CD4(+) T cells, we show that administration of soluble ovalbumin (OVA) protein, but not OVA(323-339) peptide antigen, together with an anti-IL-10 receptor (R) mAb led to the enhancement of a Th1 response upon rechallenge. Lipopolysaccharide (LPS) present in the protein was necessary for priming for Th1 recall responses in the presence of anti-IL-10R mAb, as removal of LPS abrogated this effect. Moreover, addition of LPS to the peptide did not itself allow priming for recall Th1 effector responses unless endogenous levels of IL-10 were neutralized with an anti-IL-10R mAb. A significant increase in OVA-specific IgG1 and IgG2a isotypes was observed when the protein antigen was administered with anti-IL-10R mAb; however, this was not the case with peptide antigen administered together with anti-IL-10R and LPS. Our data, showing that LPS receptor signaling and neutralization of endogenous immunosuppressive cytokines is essential for Th1 priming, has important implications for the design of relevant vaccines for effective in vivo immunotherapy.
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156
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Liu YJ, Xue CS, Zhou QX. [Expression of FAS and FASL genes in brain and effect of flunarizine on these expressions in rats after global ischemia-reperfusion]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 2000; 35:810-3. [PMID: 11218854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
AIM To explore the expression of Fas and FasL genes after ischemia-reperfusion in rats and the effect of flunarizine. METHODS Ischemia was induced by four-vessel occlusion for 30 min following reperfusion in rats. The biopsy tissues from brain were immunohistochemically assayed with Fas and FasL genes polyclonal antibody. RESULTS The expression of Fas was increased as early as 6 h after the onset of reperfusion. The peak of the expression of Fas occurred 24-48 h after ischemia-reperfusion. The expression of FasL was observed 12 h after ischemia-reperfusion and peaked at 48-72 h. The expression of Fas and FasL gene was quite obvious in the cortex and hippocampus CA1, the more sensitive areas to ischemic injury. Flunarizine i.p. 10 mg.kg-1 and 20 mg.kg-1 obviously inhibited the expression of Fas and FasL in dose-dependent manner. CONCLUSION Expression of Fas and FasL in cerebral cortex and hippocampus can be induced by global ischemia-reperfusion. Flunarizine significantly inhibited the expression of Fas and FasL genes following ischemia-reperfusion.
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Frazer JK, Jackson DG, Gaillard JP, Lutter M, Liu YJ, Banchereau J, Capra JD, Pascual V. Identification of centerin: a novel human germinal center B cell-restricted serpin. Eur J Immunol 2000; 30:3039-48. [PMID: 11069088 DOI: 10.1002/1521-4141(200010)30:10<3039::aid-immu3039>3.0.co;2-h] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
For naive B cells to mature in response to antigen triggering and become either plasma cells or memory B cells, a complex array of events takes place within germinal centers (GC) of secondary lymphoid organs. With the long-term objective of defining and characterizing molecules that control the generation of GC, we have subtracted RNA messages derived from highly purified B cells at the follicular mantle stage of differentiation from GC B cells. Using this approach, we have identified a novel molecule, centerin, belonging to the family of serine-protease inhibitors or serpins. Transcription of centerin is highly restricted to GC B cells and their malignant counterparts, Burkitt's lymphoma lines. The putative centerin protein shares the highest sequence identity with thyroxine-binding globulin and possesses arginine/serine at its P1/P1' active site, suggesting that it interacts with a trypsin-like protease(s). In addition, several other sequence features of centerin also indicate that it serves as a bonafide protease inhibitor. Finally, we demonstrate differentially up-regulated transcription of this novel gene by resting, naive B cells stimulated in vitro via CD40 signaling, while Staphylococcus aureus Cowan strain-mediated B cell activation fails to generate this reponse. Because CD40 signaling is required for naive B cells to enter the GC reaction and for GC B cells to survive, it is likely that centerin plays a role in the development and/or sustaining of GC.
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158
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Jayaraman G, Wu CW, Liu YJ, Chien KY, Fang JC, Lyu PC. Binding of a de novo designed peptide to specific glycosaminoglycans. FEBS Lett 2000; 482:154-8. [PMID: 11018540 DOI: 10.1016/s0014-5793(00)01964-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The binding of glycosaminoglycans to a synthetic peptide (SKAQKAQAKQAKQAQKAQKAQAKQAKQW-CONH(2)), consisting of a hybrid consensus heparin binding sequence, is studied using circular dichroism, fluorescence anisotropy and nuclear magnetic resonance techniques. The results unveil certain novel features, most importantly, the peptide binds preferentially to iduronic acid containing glycosaminoglycans and the dissociation constant for the peptide-heparin complex was found to be 30 nM. Interestingly, higher order intermolecular association(s)/aggregation was not observed, especially at saturating concentrations of the ligand. The helical structure of the peptide backbone, induced upon binding to a particular glycosaminoglycan is directly related to their binding affinity. In our opinion, studies on such unconventional hybrid peptide sequences containing low density basic amino acid residues would lead to the design of sequence specific glycosaminoglycan binding peptides.
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159
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Zeng XR, Xiong RG, Xu Y, Liu YJ, You XZ. Tetraaquabis[2-(4-pyridyl)ethanesulfonato-N]zinc(II). Acta Crystallogr C 2000; 56 ( Pt 8):943-4. [PMID: 10944282 DOI: 10.1107/s0108270100007964] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2000] [Accepted: 05/30/2000] [Indexed: 11/10/2022] Open
Abstract
The title compound, [Zn(C(7)H(8)NO(3)S)(2)(H(2)O)(4)], has an octahedral coordination around the central Zn atom composed of two axial N atoms from the pyridine ligands and four equatorial O atoms of water molecules, forming a monomeric centrosymmetric complex. The two Zn-N bond distances are 2.102 (3) A, while the four Zn-O bond distances range from 2.114 (2) to 2.167 (2) A. Packing is determined by hydrogen bonds formed by the water molecules. The sulfonate group does not take part in coordination to the Zn atom.
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160
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Yang GP, Nan L, Jia HB, Zhu YH, Liu YJ, Zhang K. [Bacterial genetic diversity in soils and their correlation with vegetation]. YI CHUAN XUE BAO = ACTA GENETICA SINICA 2000; 27:278-82. [PMID: 10887700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Soil is an important epicenter of biodiversity. Human activity has threatened such biodiversity through vegetation shift. As the major type of microbes, bacteria have played key roles in material cycling. Since simple morphological characters and the failure of the major portion of bacteria in surviving artificial cultivation have hindered bacterial diversity from analyses using traditional taxonomic approaches, bacterial diversity and its correlation with vegetation is less understood. In order to detour cultivation, tag serial sequencing strategy was developed in this study, in which a 26 base pair highly variable region has been chosen from 16S ribosomal RNA gene as variant-representing tags, ligated into serials and sequenced. Molecular bacterial diversity in soils has been determined using tag types, tag frequencies and diversity index as parameters. The correlation of bacterial diversity with vegetation has been explored as well. Bacterial diversity and differentiation correlate highly with contents of organic matter and nitrogen of soils and further vegetation.
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161
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Banchereau J, Briere F, Caux C, Davoust J, Lebecque S, Liu YJ, Pulendran B, Palucka K. Immunobiology of dendritic cells. Annu Rev Immunol 2000; 18:767-811. [PMID: 10837075 DOI: 10.1146/annurev.immunol.18.1.767] [Citation(s) in RCA: 4752] [Impact Index Per Article: 198.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Dendritic cells (DCs) are antigen-presenting cells with a unique ability to induce primary immune responses. DCs capture and transfer information from the outside world to the cells of the adaptive immune system. DCs are not only critical for the induction of primary immune responses, but may also be important for the induction of immunological tolerance, as well as for the regulation of the type of T cell-mediated immune response. Although our understanding of DC biology is still in its infancy, we are now beginning to use DC-based immunotherapy protocols to elicit immunity against cancer and infectious diseases.
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162
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Liu YJ, Nakagawa Y, Toya K, Wang Y, Saegusa H, Nakanishi T, Ohzeki T. Effects of spironolactone on systolic blood pressure in experimental diabetic rats. Kidney Int 2000; 57:2064-71. [PMID: 10792625 DOI: 10.1046/j.1523-1755.2000.00055.x] [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: 11/20/2022]
Abstract
BACKGROUND Mineralocorticoid hormones, which maintain electrolyte balance and blood pressure, are thought to be associated not only with the expression of renal 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2), but also with that of intracellular mineralocorticoid receptors (MRs). The present study was designed to test whether the mineralocorticoid action of glucocorticoid corticosterone on renal MR is involved in the development of diabetes-associated hypertension by measuring the alterations of renal 11beta-HSD2. METHOD We measured the mean systolic blood pressure, renal 11beta-HSD1, and mRNA levels in streptozotocin (STZ)-induced diabetic rats that received spironolactone, insulin, or no treatment, and in nondiabetic controls that received spironolactone. RESULTS Four weeks after an injection of STZ, the renal 11beta-HSD2 and mRNA levels were significantly lower in diabetic rats than in control rats, and the mean systolic blood pressure was 14.8% higher in diabetic rats than in controls. Subcutaneous injections of spironolactone into diabetic rats for three weeks partially reversed the decrease in renal 11beta-HSD2 activity and gene expression, and prevented the mean systolic blood pressure elevation. Spironolactone treatment for one week also resulted in a significant reduction in mean systolic blood pressure during the development of diabetic hypertension. However, treatment with STZ did not significantly decrease the renal 11beta-HSD1 activity and mRNA expression, and spironolactone treatment did not exert a significant effect on this enzyme in STZ-induced diabetic rats. CONCLUSION In the development of diabetes-induced hypertension, the effect of spironolactone on mean systolic blood pressure may be associated with the mineralocorticoid effects of corticosterone on renal MR, as well as an alteration of renal 11beta-HSD2 activity and its mRNA expression in insulin-dependent diabetic rats.
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163
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Solvason N, Wu WW, Parry D, Mahony D, Lam EW, Glassford J, Klaus GG, Sicinski P, Weinberg R, Liu YJ, Howard M, Lees E. Cyclin D2 is essential for BCR-mediated proliferation and CD5 B cell development. Int Immunol 2000; 12:631-8. [PMID: 10784609 DOI: 10.1093/intimm/12.5.631] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Progression into G(1) in B lymphocytes is regulated by cyclins D2 and D3, components of the cell cycle machinery currently believed to have overlapping and potentially redundant roles in cell cycle control. To study the specific role of cyclin D2 in B lymphocyte proliferation, we examined B cells from cyclin D2(-/-) mice and demonstrate a specific requirement for cyclin D2 in BCR- but not CD40- or lipopolysaccharide-induced proliferation. Furthermore, conventional B cell development proceeds normally in the mutant mice; however, the CD5 B cell compartment is dramatically reduced, suggesting that cyclin D2 is important in CD5 B cell development as well as antigen-dependent B cell clonal expansion.
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164
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Liu YJ, Blom B. Introduction: TH2-inducing DC2 for immunotherapy. Blood 2000; 95:2482-3. [PMID: 10753824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
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165
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Fu X, Liu YJ, Ciray N, Olovsson M, Ulmsten U, Gylfe E. Oxytocin-induced oscillations of cytoplasmic Ca2+ in human myometrial cells. Acta Obstet Gynecol Scand 2000; 79:174-9. [PMID: 10716297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
BACKGROUND To investigate the mechanisms of oxytocin (OT) induced oscillations of the cytoplasmic Ca2+ concentration ([Ca2+]i) in cultured human myometrial cells. METHODS [Ca2+]i was measured in individual myometrial cells by dual wavelength spectrophotofluorometry using the fluorescent indicator fura-2. Myometrium was obtained at abdominal hysterectomy (n=8) and during cesarean section (n=7). RESULTS OT (10-300 nM) typically induced [Ca2+]i oscillations with frequencies in the 0.6-0.8/min range. There were no obvious differences in the responses of cells taken from non-pregnant and term pregnant women. The frequency and amplitude of the oscillations were not significantly affected by OT concentrations up to 300 nM. The amplitude of the oscillations decreased in the presence of the voltage-dependent Ca2+ channel antagonist verapamil and gradually disappeared in Ca2+-free medium. The oscillations were further blocked by the inorganic Ca2+ antagonist La3+ and by the intracellular Ca2+-ATPase inhibitor 2.5-di-tert-butylhydroquinone (DTBHQ). Caffeine inhibited the OT-induced oscillations in a concentration-dependent manner. DTBHQ and high concentrations of OT made [Ca2+]i remarkably sensitive to changes in the external Ca2+ concentration. CONCLUSIONS The results indicate that OT-induced [Ca2+]i oscillations in human myometrial cells are due to inositol 1,4,5-trisphosphate-mediated release of intracellular Ca2+ combined with capacitative as well as voltage-dependent influx of the ion.
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Stagni G, O'Donnell D, Liu YJ, Kellogg DL, Morgan T, Shepherd AM. Intradermal microdialysis: kinetics of iontophoretically delivered propranolol in forearm dermis. J Control Release 2000; 63:331-9. [PMID: 10601728 DOI: 10.1016/s0168-3659(99)00214-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Intradermal microdialysis permits us to measure the concentration in dermis of drugs applied to the skin. Microdialysis is especially efficient in sampling water-soluble molecules. Consequently, it appears particularly suitable to study current based delivery systems like iontophoresis that deliver ions or highly polar molecules. The purpose of this work was to evaluate the adequacy of a skin microdialysis technique to characterize and quantify the dermatopharmacokinetics of iontophoretically delivered propranolol in the dermis of healthy human volunteers. Linear microdialysis probes were inserted in the subject's forearm skin and an iontophoresis device was installed above them. Constant current was applied for two periods of 1 h each separated by a 1-h interval. Dialysate samples were collected every 6 min for 4.4 h and analyzed by HPLC. Probes were always placed in the dermis as measured by ultrasonography. Propranolol was detectable in the dialysate. It was possible to build detailed concentration vs. midtime profiles that mirrored the current applied. Elimination rate from the dermis had first-order kinetics and was similar in all subjects. Quantification of the absorption process, indexed by lag-time and area under the concentration curve showed a high inter- and intrasubject variability that did not correlate with probe depth.
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167
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Zhu DR, Xu Y, Liu YJ, Song Y, Zhang Y, You XZ. 4-(4-hydroxybenzylideneamino)-4H-1,2,4-triazole hemihydrate. Acta Crystallogr C 2000; 56 ( Pt 2):242-3. [PMID: 10777903 DOI: 10.1107/s0108270199014572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/1999] [Accepted: 11/09/1999] [Indexed: 11/10/2022] Open
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Hsieh CH, Liu YJ. Fast search algorithms for vector quantization of images using multiple triangle inequalities and wavelet transform. IEEE TRANSACTIONS ON IMAGE PROCESSING : A PUBLICATION OF THE IEEE SIGNAL PROCESSING SOCIETY 2000; 9:321-328. [PMID: 18255405 DOI: 10.1109/83.826771] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The encoding of vector quantization (VQ) needs expensive computation for searching the closest codevector to the input vector. This paper presents several fast encoding algorithms based on multiple triangle inequalities and wavelet transform to overcome this problem. The multiple triangle inequalities confine a search range using the intersection of search areas generated from several control vectors. A systematic way for designing the control vectors is also presented. The wavelet transform combined with the partial distance elimination is used to reduce the computational complexity of the distance calculation of vectors. The proposed algorithms provide the same coding quality as the full search method. The experimental results indicate that the new algorithms perform more efficiently than existing algorithms.
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Duan K, Liu CQ, Liu YJ, Ren J, Dunn NW. Nucleotide sequence and thermostability of pND324, a 3.6-kb plasmid from Lactococcus lactis. Appl Microbiol Biotechnol 1999; 53:36-42. [PMID: 10645623 DOI: 10.1007/s002530051611] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A 3.6-kb plasmid, designated pND324, was isolated from Lactococcus lactis subsp. lactis LL57-1. Sequence analysis revealed the presence of three open reading frames, rep324, orfX1 and orfX2, which are flanked by two non-coding regions, ori324 and cisE. The minimal replication region of pND324 consists of ori324 and rep324, which is closely related to the lactococcal theta-type replicons of the pWV02/pCI305 family. pND324 was stable at both 30 degrees C and 37 degrees C, whereas derivatives that lack cisE were highly unstable at 37 degrees C, indicating that cisE is essential for thermostability. Sequences that are similar to orfX1 are commonly present in the lactococcal theta-type plasmids. The orfX2 product is homologous to TrfA, a 43-kDa protein of the E. coli theta-type plasmid RK2 required for replication and maintenance. Plasmid deletion and stability analyses showed that orfX2 is involved in the thermostability of pND324. Based on the minimal replication region of pND324, an integrative cloning vector, designated pND421, was constructed. In L. lactis LM0230, cells that carried pND421 integrated into its host chromosomal DNA could be recovered readily following incubation at 37 degrees C for 40 generations. The integrated plasmid was totally stable for at least 100 generations without selection at 30 degrees C.
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170
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Liu YJ, Whelen S, Hall BD. Phylogenetic relationships among ascomycetes: evidence from an RNA polymerse II subunit. Mol Biol Evol 1999; 16:1799-808. [PMID: 10605121 DOI: 10.1093/oxfordjournals.molbev.a026092] [Citation(s) in RCA: 1356] [Impact Index Per Article: 54.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In an effort to establish a suitable alternative to the widely used 18S rRNA system for molecular systematics of fungi, we examined the nuclear gene RPB2, encoding the second largest subunit of RNA polymerase II. Because RPB2 is a single-copy gene of large size with a modest rate of evolutionary change, it provides good phylogenetic resolution of Ascomycota. While the RPB2 and 18S rDNA phylogenies were highly congruent, the RPB2 phylogeny did result in much higher bootstrap support for all the deeper branches within the orders and for several branches between orders of the Ascomycota. There are several strongly supported phylogenetic conclusions. The Ascomycota is composed of three major lineages: Archiascomycetes, Saccharomycetales, and Euascomycetes. Within the Euascomycetes, plectomycetes, and pyrenomycetes are monophyletic groups, and the Pleosporales and Dothideales are distinct sister groups within the Loculoascomycetes. We confirm the placement of Neolecta within the Archiascomycetes, suggesting that fruiting body formation and forcible discharge of ascospores were characters gained early in the evolution of the Ascomycota. These findings show that a slowly evolving protein-coding gene such as RPB2 is useful for diagnosing phylogenetic relationships among fungi.
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Saegusa H, Nakagawa Y, Liu YJ, Ohzeki T. Influence of placental 11beta-hydroxysteroid dehydrogenase (11beta-HSD) inhibition on glucose metabolism and 11beta-HSD regulation in adult offspring of rats. Metabolism 1999; 48:1584-8. [PMID: 10599992 DOI: 10.1016/s0026-0495(99)90249-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Placental 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) converts glucocorticoids to 11-keto-products and is believed to play an important role in protecting fetuses from higher maternal glucocorticoid levels. Recent reports have speculated that prenatal glucocorticoid exposure leads to fetal growth retardation and adult offspring hypertension and hyperglycemia. To investigate the effects of placental 11beta-HSD2 inhibition on glucose metabolism and the 11beta-HSD system in adult offspring, pregnant rats were treated with daily injections of carbenoxolone (CBX), an inhibitor of 11beta-HSD. The offspring of the maternal CBX treatment group showed reduced birth weight (treated v control, 5.6 +/- 0.5 v 6.4 +/- 0.4 g, P < .0001). In adult offspring of the maternal CBX treatment group, plasma hemoglobin A1c was significantly increased (7.3% +/- 1.8% v 4.8% +/- 0.3%, P < .01) and glucose intolerance was shown on the oral glucose tolerance test. The gene expression of hepatic 11beta-HSD1 and renal 11beta-HSD2 was decreased 87.6% (P < .05) and 52.3% (P < .01) in adult offspring of the maternal CBX treatment group, whereas renal 11beta-HSD1 was not significantly altered. The change in 11beta-HSD activity corresponded to the change in the gene expression. These results suggest that inhibition of placental 11beta-HSD2 causes growth retardation, glucose intolerance, and partial suppression of the 11beta-HSD system in the offspring.
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Abstract
Ca2+ signaling was studied in pancreatic polypeptide (PP)-secreting cells isolated from mouse islets of Langerhans. After measuring the cytoplasmic Ca2+ concentration ([Ca2+]i), the cells were identified by immunocytochemistry. Most PP-cells reacted to carbachol and epinephrine with prompt and reversible elevation of [Ca2+]i, often manifested as slow oscillations. The carbachol effect was muscarinic, because it was inhibited by atropine. Beta-adrenergic elevation of cAMP explains the epinephrine stimulation, which was mimicked by an activator of adenylate cyclase and blocked by an inhibitor of protein kinase A. The responses to carbachol and epinephrine apparently involve depolarization with opening of voltage-dependent Ca2+ channels, because the effects were prevented by the Ca2+ channel antagonist methoxyverapamil and by diazoxide, which activates ATP-dependent K+ (K(ATP)) channels. Being equipped with K(ATP) channels, the PP-cells often responded to tolbutamide or high concentrations of glucose with elevation of [Ca2+]i. Somatostatin reversed the [Ca2+]i elevation obtained by carbachol, epinephrine, tolbutamide, and glucose. These preliminary studies support the idea that glucose has a direct stimulatory effect on the PP-cells, which can be masked by locally released somatostatin. Expressing both K(ATP) channels and voltage-dependent Ca2+ channels, the PP-cells share fundamental regulatory mechanisms with other types of islet cells.
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173
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Peng CJ, Chang CM, Kuo SE, Liu YJ, Kuo HC, Lin SJ. Analysis of anthropometric growth trends and prevalence of abnormal body status in Tainan elementary-school children. ACTA PAEDIATRICA TAIWANICA = TAIWAN ER KE YI XUE HUI ZA ZHI 1999; 40:406-13. [PMID: 10927954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Objectives of this study were to examine the prevalence of over/underweight or obesity in Chinese children and investigate the trend of anthropometric change through the years. Cross-sectional measurements on randomly selected 6,373 Tainan elementary-school children were conducted in 1997. Anthropometric parameters such as height, weight, body mass index (BMI), triceps skinfold thickness (TSF), mid-arm circumference (MAC) and body-fat percentage (%FAT) were measured. Girls and boys had an average of 4.8 cm and 5.1 cm, or 3.7% and 3.9% increase in height, and 5.5 kg, 6.2 kg, or 19.9% and 22.2% increase in weight when compared to data of nationwide survey in 1986-88. If the height and weight were compared to the data of nationwide survey in 1993-1996, Tainan girls and boys would have similar height but have averaged 3.4% and 4.7% heavier weight. Mean BMI reached 19.4 kg/m2 for girls and 19.6 kg/m2 for boys of age 12 to 13. Mean %FAT of girls was 24.3% and of boys was 23.7%. When using weight-for-length index (WLI) larger than 1.2, mean weight exceeding 120% of age-and-sex specific mean weight, %FAT exceeding 30% to evaluate prevalence of obesity, results would be 42.1%, 17% and 22.0% respectively. In conclusion, both sexes had faster growth in weight than in height in recent 10 years. Boys had significantly higher weight, WLI, BMI, MAC than girls, while girls had significantly higher TSF and %FAT than boys. Prevalence of obesity is highly method-dependent. Appropriate index and cutoff values need to be developed.
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174
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Marriott DP, Dougall IG, Meghani P, Liu YJ, Flower DR. Lead generation using pharmacophore mapping and three-dimensional database searching: application to muscarinic M(3) receptor antagonists. J Med Chem 1999; 42:3210-6. [PMID: 10464008 DOI: 10.1021/jm980409n] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
By using a pharmacophore model, a geometrical representation of the features necessary for molecules to show a particular biological activity, it is possible to search databases containing the 3D structures of molecules and identify novel compounds which may possess this activity. We describe our experiences of establishing a working 3D database system and its use in rational drug design. By using muscarinic M(3) receptor antagonists as an example, we show that it is possible to identify potent novel lead compounds using this approach. Pharmacophore generation based on the structures of known M(3) receptor antagonists, 3D database searching, and medium-throughput screening were used to identify candidate compounds. Three compounds were chosen to define the pharmacophore: a lung-selective M(3) antagonist patented by Pfizer and two Astra compounds which show affinity at the M(3) receptor. From these, a pharmacophore model was generated, using the program DISCO, and this was used subsequently to search a UNITY 3D database of proprietary compounds; 172 compounds were found to fit the pharmacophore. These compounds were then screened, and 1-[2-(2-(diethylamino)ethoxy)phenyl]-2-phenylethanone (pA(2) 6.67) was identified as the best hit, with N-[2-(piperidin-1-ylmethyl)cycohexyl]-2-propoxybenz amide (pA(2) 4. 83) and phenylcarbamic acid 2-(morpholin-4-ylmethyl)cyclohexyl ester (pA(2) 5.54) demonstrating lower activity. As well as its potency, 1-[2-(2-(diethylamino)ethoxy)phenyl]-2-phenylethanone is a simple structure with limited similarity to existing M(3) receptor antagonists.
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175
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Siegal FP, Kadowaki N, Shodell M, Fitzgerald-Bocarsly PA, Shah K, Ho S, Antonenko S, Liu YJ. The nature of the principal type 1 interferon-producing cells in human blood. Science 1999; 284:1835-7. [PMID: 10364556 DOI: 10.1126/science.284.5421.1835] [Citation(s) in RCA: 1650] [Impact Index Per Article: 66.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Interferons (IFNs) are the most important cytokines in antiviral immune responses. "Natural IFN-producing cells" (IPCs) in human blood express CD4 and major histocompatibility complex class II proteins, but have not been isolated and further characterized because of their rarity, rapid apoptosis, and lack of lineage markers. Purified IPCs are here shown to be the CD4(+)CD11c- type 2 dendritic cell precursors (pDC2s), which produce 200 to 1000 times more IFN than other blood cells after microbial challenge. pDC2s are thus an effector cell type of the immune system, critical for antiviral and antitumor immune responses.
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