151
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Combrink KD, Gulgeze HB, Yu KL, Pearce BC, Trehan AK, Wei J, Deshpande M, Krystal M, Torri A, Luo G, Cianci C, Danetz S, Tiley L, Meanwell NA. Salicylamide inhibitors of influenza virus fusion. Bioorg Med Chem Lett 2000; 10:1649-52. [PMID: 10937716 DOI: 10.1016/s0960-894x(00)00335-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Structural variation of the quinolizidine heterocycle of the influenza fusion inhibitor BMY-27709 was examined by several topological dissections in order to illuminate the critical features of the ring system. This exercise resulted in the identification of a series of synthetically more accessible decahydroquinolines that retained the structural elements of BMY-27709 important for antiviral activity. The 2-methyl-cis-decahydroquinoline 6f was the most potent influenza inhibitor identified that demonstrated an EC50 of 90 ng/mL in a plaque reduction assay.
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Affiliation(s)
- K D Combrink
- Department of Chemistry, The Bristol-Myers Squibb Pharmaceutical Research Institute, Wallingford, CT 05492, USA.
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152
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Yu T, Xiao Y, Bai Y, Ru Q, Luo G, Dierich MP, Chen Y. Human interferon-beta inhibits binding of HIV-1 gp41 to lymphocyte and monocyte cells and binds the potential receptor protein P50 for HIV-1 gp41. Immunol Lett 2000; 73:19-22. [PMID: 10963806 DOI: 10.1016/s0165-2478(00)00196-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Previous findings have indicated that HIV-1 gp41 like human type I interferon (IFN) could inhibit lymphocyte proliferation and up-modulate MHC class I, II and ICAM-1 molecule expression, and a common epitope exists between gp41 and type I interferon (IFN-alpha and -beta) in the receptor binding regions. To clarify the relationship between human type I interferon and HIV-1 gp41, we tried to inhibit recombinant soluble gp41-binding to human T, B and monocyte cell lines by human IFN-alpha, -beta and -gamma. It was interestingly observed that IFN-beta after preincubating with cells could inhibit the binding of rsgp41 to H9, Raji and U937 cells (T, B and monocyte cell lines), while this binding could not be inhibited by another type I interferon (IFN-alpha) and a type II interferon (IFN-gamma). It was further examined whether human IFN-alpha and -beta bind to the gp41 binding protein P50. In ELISA-assay, the human IFN-beta, but not IFN-alpha, could bind to P50 which was identified as a potential cellular receptor protein for gp41-binding. By the affinity capillary electrophoresis (ACE) analysis, formation of stable IFN-beta-P50 complex was observed. These results indicate that IFN-beta binds the potential receptor protein P50. Based on these experimental evidences and previous studies, it was presumed that the potential cellular receptor protein P50 may be the 51 kDa subunit of human IFN-alpha/beta receptor, which needs to be verified in the future.
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Affiliation(s)
- T Yu
- Department of Biology, Laboratory of Immunology, Tsinghua University, Beijing 100084, People's Republic of China
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153
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Luo G, Zhang JQ, Nguyen TP, Herrera AH, Paterson B, Horowits R. Complete cDNA sequence and tissue localization of N-RAP, a novel nebulin-related protein of striated muscle. Cell Motil Cytoskeleton 2000; 38:75-90. [PMID: 9295142 DOI: 10.1002/(sici)1097-0169(1997)38:1<75::aid-cm7>3.0.co;2-g] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have cloned and sequenced the full-length cDNA of N-RAP, a novel nebulin-related protein, from mouse skeletal muscle. The N-RAP message is specifically expressed in skeletal and cardiac muscle, but is not detected by Northern blot in non-muscle tissues. The full-length N-RAP cDNA contains an open reading frame of 3,525 base pairs which is predicted to encode a protein of 133 kDa. A 587 amino acid region near the C-terminus is 45% identical to the actin binding region of human nebulin, containing more than 2 complete 245 residue nebulin super repeats. The N-terminus contains the consensus sequence of a cysteine-rich LIM domain, which may function in mediating protein-protein interactions. These data suggest that the encoded protein may link actin filaments to some other proteins or structure. We expressed full-length N-RAP in Escherichia coli, as well as the nebulin-like super repeat region of N-RAP (N-RAP-SR) and the region between the LIM domain and N-RAP-SR (N-RAP-IB). An anti-N-RAP antibody raised against a 30 amino acid peptide corresponding to sequence from N-RAP-IB detected recombinant N-RAP and N-RAP-IB, but failed to detect N-RAP-SR. This antibody specifically identified a 185 kDa band as N-RAP on immunoblots of mouse skeletal and cardiac muscle proteins. In an assay of actin binding to electrophoresed and blotted proteins, we detected significant actin binding to expressed nebulin super repeats and N-RAP-SR, but only a trace amount of binding to N-RAP-IB. In immunofluorescence experiments, N-RAP was found to be localized at the myotendinous junction in mouse skeletal muscle and at the intercalated disc in cardiac muscle. Based on its domain organization, actin binding properties, and tissue localization, we propose that N-RAP plays a role in anchoring the terminal actin filaments in the myofibril to the membrane and may be important in transmitting tension from the myofibrils to the extracellular matrix.
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Affiliation(s)
- G Luo
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892-2755, USA
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154
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Liu Q, Guntuku S, Cui XS, Matsuoka S, Cortez D, Tamai K, Luo G, Carattini-Rivera S, DeMayo F, Bradley A, Donehower LA, Elledge SJ. Chk1 is an essential kinase that is regulated by Atr and required for the G(2)/M DNA damage checkpoint. Genes Dev 2000; 14:1448-59. [PMID: 10859164 PMCID: PMC316686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Chk1, an evolutionarily conserved protein kinase, has been implicated in cell cycle checkpoint control in lower eukaryotes. By gene disruption, we show that CHK1 deficiency results in a severe proliferation defect and death in embryonic stem (ES) cells, and peri-implantation embryonic lethality in mice. Through analysis of a conditional CHK1-deficient cell line, we demonstrate that ES cells lacking Chk1 have a defective G(2)/M DNA damage checkpoint in response to gamma-irradiation (IR). CHK1 heterozygosity modestly enhances the tumorigenesis phenotype of WNT-1 transgenic mice. We show that in human cells, Chk1 is phosphorylated on serine 345 (S345) in response to UV, IR, and hydroxyurea (HU). Overexpression of wild-type Atr enhances, whereas overexpression of the kinase-defective mutant Atr inhibits S345 phosphorylation of Chk1 induced by UV treatment. Taken together, these data indicate that Chk1 plays an essential role in the mammalian DNA damage checkpoint, embryonic development, and tumor suppression, and that Atr regulates Chk1.
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Affiliation(s)
- Q Liu
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030, USA
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155
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Luo G, Hu Q, Su X. [The contrast study of preoperative flash visual evoked potential test and the postoperative resumed visual acuity in senile cataract patients]. Yan Ke Xue Bao 2000; 16:81-3. [PMID: 12579909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
PURPOSE To study the using value of flash visual evoked potentials (FVEP) in predicting the resumed visual acuities in senile cataract patients. METHODS Forty-three eyes with senile cataract had been conducted extracapsular cataract extraction combined with posterior chamber intraocular lens implantation. The contrast study had been carried out in this research between preoperative FVEP, light projection and color discrimination tests with the postoperative regained visual acuities. RESULTS There were significant correlations between the regained visual acuities and the amplitudes of FVEP (X1), the latencies of P1 wave (X2) as well as color discriminations (P < 0.01). The coefficients were 0.7277, -0.5678 and 0.4302 in sequence. There was no correlation between the resumed visual acuities and the light projection test before operation. The formula of linear regression between the visual acuities (Y) and the indexes of FVEP was Y = 0.2255 +0.047X1 -0.0026X2. CONCLUSION FVEP is an effective method to evaluate the visual function before the cataract operation. It may predict the resumed visual acuity.
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Affiliation(s)
- G Luo
- Zhongshan Ophthalmic Center, Sun Yat-sen University of Medical Sciences, Guangzhou 510060, China
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156
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Wang J, Sun S, Zhang X, Luo G, Wang Y, Wang J. [Spectrum analysis of blue ball-point ink components by FTIR microsope]. Guang Pu Xue Yu Guang Pu Fen Xi 2000; 20:326-328. [PMID: 12958946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The FT-IR microscope spectra of 108 kinds of blue ball-point writing inks have been analyzed in detail in this paper. According to the transmittance spectra, the composition in the ink such as the solvent, the pigment and the resin was identified. It is the base to determination of the age of ball-point writing inks nondestructively.
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Affiliation(s)
- J Wang
- Department of Chemistry, Tsinghua University, 100084 Beijing
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157
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Abstract
We reported a 5-years old boy with frosted branch angiitis in both eyes. The visual acuities of the two eyes were suddenly lost to 5/50. The fluorescein angiography, electroretinograms (ERGs) and pattern evoked potentials (PVEPs) had been tested at the acute and the recovery stage of the disease. At the onset of the disease, fluorescein angiography showed obvious dye leakage from dilated retinal veins. The PVEPs and whole field ERGs including rod, maximum, OPs and cone responses were seriously decreased and prolonged, indicating that the visual pathway's and retinal functions were greatly damaged. The patient had an excellent response to systemic prednisone. One month after the treatment, the visual acuities recovered to 60/50 in both eyes. The fluorescein angiography showed that leakage from blood vessels was diminished, but the lesions at macula and optic disc were persisted a longer time even to the end of treatment. Through 6 months medication, nearly all of the electrophysiological abnormalities had been resolved.
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Affiliation(s)
- G Luo
- Zhongshan Ophthalmic Center, Sun Yat-sen University of Medical Sciences, Guangzhou, China.
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158
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Abstract
The phospholipid monolayer at an air/water interface is widely used to mimic the biological membrane. The dynamic process of the protein or peptide interacting with lipid molecules can be reflected in the change in surface pressure of the monolayer. But the conventional method used to measure the surface pressure change gives results that cannot easily be correlated with the contribution of a single protein molecule. Previously, measuring the surface concentration of the protein molecules at the air/water interface has required the protein to be labeled with radioactivity or fluorescence. Here, a new method using capillary electrophoresis is introduced to measure the surface concentration of the protein. The results show at least two advantages of the new method: The numerical results of protein concentration can be obtained in a more precise and rapid way; and there is no need to label the protein sample or to build a special monolayer setup.
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Affiliation(s)
- S Wang
- Department of Biological Sciences & Biotechnology, Tsinghua University, Beijing, People's Republic of China
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159
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Wang J, Sun S, Zhang X, Luo G, Wang Y, Wang Y, Wang J. [Spectral analysis and composition determination of blue ballpoint writing inks]. Guang Pu Xue Yu Guang Pu Fen Xi 2000; 20:192-194. [PMID: 12953485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Main compositions of ballpoint inks were determined by analyzing some tropical Fourier Transform Infrared(FTIR) spectra of 108 kinds of ballpoint inks. By using this method, the blue ink samples have been divided to two groups, 18 species depend on their spectral characteristics such as peak location, peak intensity. The reaction mechanism of age changes due to aging of the ink's compositions was discussed. The study is the first step for establishing the analytical date base of ballpoint inks system and estimating the age of ballpoint in written text has been offered. The advantage of this method is fast, reliable and nondestructive.
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Affiliation(s)
- J Wang
- Department of Chemistry, Tsinghua University, 100084 Beijing
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160
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Stenner-Liewen F, Luo G, Sahin U, Tureci O, Koslovski M, Kautz I, Liewen H, Pfreundschuh M. Definition of tumor-associated antigens in hepatocellular carcinoma. Cancer Epidemiol Biomarkers Prev 2000; 9:285-90. [PMID: 10750667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
With an estimated annual incidence of about one million cases, hepatocellular carcinoma (HCC) is one of the most common neoplasms worldwide. Of all malignant diseases, it is the major cause of death in some regions of Africa and Asia. The pathogenic mechanisms responsible for HCC are not well defined, and therapeutic means, especially in inoperable HCCs, are still unsatisfactory and await improvement. In the quest for tumor antigens exploitable for gene therapy, we studied immune responses in the context of HCC. A cDNA library derived from a human HCC sample was screened using the SEREX approach. Nineteen distinct antigens reactive with autologous IgG were identified. Sequence analysis revealed three of the cDNA clones to code for hitherto unknown proteins and 16 known genes products. Proteins as diverse in function as LDH, albumin, and kinectin were found. Furthermore, proteins involved in the transcription/translation machinery had elicited an immune response in the autologous host. A panel of allogenic sera including sera from patients with hepatitis, liver cirrhosis, HCC, and other tumor entities, as well as sera from normal individuals, was used for frequency analysis of antibody responses. Whereas allogenic sera of HCC patients detected most antigens at a high percentage, control sera were rarely antibody-positive. The nature of the major fraction of antigens described here are linked to liver. Thus, our findings demonstrate not only the complexity of the humoral immune response against HCC, but may also offer new insight into mechanisms underlying transformation of the liver cell.
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Affiliation(s)
- F Stenner-Liewen
- University of the Saarland, Medizinische Klinik I, Homburg/Saar, Germany.
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161
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Cai Z, Chen Z, Wu W, Zhou J, Luo G. [Gil-Vernet anti-reflux operation by united application of television laparoscopy and vesicourethral laparoscopy]. Zhonghua Wai Ke Za Zhi 2000; 38:143-4. [PMID: 11832014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To discuss the possibility of united application of television laparoscopy and vesicourethral laparoscopy in Gil-Vernet operation. METHODS The animal model of vesicourethral reflux (VUR) was established using rabbits. The Gil-Vernet operation was carried out by united application of television laparoscopy and vesicourethral laparoscopy. RESULTS The VUR model was successfully established in 13 rabbits, and the reflux was successfully cured by microsurgical methods. CONCLUSIONS This method had the advantages of television laparoscopy, vesicourethral laparoscopy and the Gil-Vernet such as no dissection of inner part of ureter-bladder wall, small wound, less bleeding, fast recovery, less complication and possible repetitive operation. It can be used in ill children with VUR.
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Affiliation(s)
- Z Cai
- Laparoscopy Center, Shenzhen Central Hospital, Shenzhen 518036, China
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162
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Luo G, Wu J, Yi S. [Prolonging the survival of transplanted alloskin by transferring the CTLA(4)Ig locally with recombinant adenovirus vector in mice]. Zhonghua Shao Shang Za Zhi 2000; 16:37-9. [PMID: 11876841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
OBJECTIVE To find a simple and practical way to prolong the survival of transplanted alloskin to cover the burn and other wounds. METHODS A recombinant CTLA(4)Ig-Adenovirus expression vector was constructed by means of homo recombination, and then transferred either into cultured murine skin grafts ex vivo or local wound surface. The expression of CTLA(4)Ig in cultured skin was immunohistochemically determined. Moreover, the survival time of transplanted alloskin from Kunming mice to Balb/c mice was evaluated. RESULTS The CTLA(4)Ig-Adenovirus vector could be successfully transferred and expressed in the cultured murine skin, and the locally used recombinant CTLA(4)Ig-Adenovirus vector could significantly prolong the survival of the transplanted alloskin from 8 d to 21 d. CONCLUSION Local transfection of the CTLA(4)Ig-Adenovirus vector is a simple and effective way to prolong the survival of alloskin grafts.
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Affiliation(s)
- G Luo
- Institute of Burn Research, Southwestern Hospital, Third Military Medical University, Chongqing 400038, China
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163
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164
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Abstract
Signal transducers and activators of transcription (Stat) are latent transcription factors that participate in cytokine signaling by regulating the expression of early response genes. Our previous studies showed that Stat5 functions not only as a transcriptional activator but also as a transcriptional inhibitor, depending on the target promoter. This report further investigates the mechanism of Stat5b-mediated inhibition and demonstrates that PRL-inducible Stat5b inhibits nuclear factorkappaB (NFkappaB) signaling to both the interferon regulatory factor-1 promoter and to the thymidine kinase promoter containing multimerized NFkappaB elements (NFkappaB-TK). Further, PRL-inducible Stat5b inhibits tumor necrosis factor-alpha signaling presumably by inhibiting endogenous NFkappaB. This Stat5b-mediated inhibitory effect on NFkappaB signaling is independent of Stat5b-DNA interactions but requires the carboxyl terminus of Stat5b as well as Stat5b nuclear translocation and/or accumulation, suggesting that Stat5b is competing for a nuclear factor(s) necessary for NFkappaB-mediated activation of target promoters. Increasing concentrations of the coactivator p300/CBP reverses Stat5b inhibition at both the interferon-regulatory factor-1 and NFkappaB-TK promoters, suggesting that Stat5b may be squelching limiting coactivators via protein-protein interactions as one mechanism of promoter inhibition. These results further substantiate our observation that Stat factors can function as transcriptional inhibitors. Our studies reveal cross-talk between the Stat5b and NFkappaB signal transduction pathways and suggest that Stat5b-mediated inhibition of target promoters occurs at the level of protein-protein interactions and involves competition for limiting coactivators.
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Affiliation(s)
- G Luo
- Department of Microbiology and Immunology, Baylor College of Medicine, Houston, Texas 77030, USA
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165
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Abstract
Based on the findings that two cellular proteins of 45 kDa (P45) and 62 kDa (P62) serve as the putative receptor molecules for binding of HIV-1 transmembrane protein gp41 to human T, B lymphocytes and monocytes, we examined whether HIV-2 gp36 and HIV-1 gp41 share the putative receptor proteins P45 and P62. In SPR-assay (SPR: surface plasmon resonance), the recombinant soluble gp36 (rsgp36: Env aa518-678 from clone ROD) like the recombinant soluble gp41 (rsgp41: Env aa539-684 from clone BH10) was binding to P45 and P62. By affinity capillary electrophoresis (ACE)-analysis, formation of stable rsgp36-P45 and rsgp36-P62 complexes were confirmed, and the interactions of rsgp36 with P45 and P62 is quite strong with a fast association rate and a slow dissociation rate. These results indicate that HIV-2 gp36 and HIV-1 gp41 have the common putative cellular receptor proteins P45 and P62, and the binding of gp36 to human lymphocytes and monocytes could be based on the interaction between gp36 and P45 and P62.
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Affiliation(s)
- Y H Chen
- Laboratory of Immunology, School of Life Science and Engineering, Tsinghua University, Beijing, PR, China.
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166
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Luo G, Hamatake RK, Mathis DM, Racela J, Rigat KL, Lemm J, Colonno RJ. De novo initiation of RNA synthesis by the RNA-dependent RNA polymerase (NS5B) of hepatitis C virus. J Virol 2000; 74:851-63. [PMID: 10623748 PMCID: PMC111606 DOI: 10.1128/jvi.74.2.851-863.2000] [Citation(s) in RCA: 235] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hepatitis C virus (HCV) NS5B protein possesses an RNA-dependent RNA polymerase (RdRp) activity, a major function responsible for replication of the viral RNA genome. To further characterize the RdRp activity, NS5B proteins were expressed from recombinant baculoviruses, purified to near homogeneity, and examined for their ability to synthesize RNA in vitro. As a result, a highly active NS5B RdRp (1b-42), which contains an 18-amino acid C-terminal truncation resulting from a newly created stop codon, was identified among a number of independent isolates. The RdRp activity of the truncated NS5B is comparable to the activity of the full-length protein and is 20 times higher in the presence of Mn(2+) than in the presence of Mg(2+). When a 384-nucleotide RNA was used as the template, two major RNA products were synthesized by 1b-42. One is a complementary RNA identical in size to the input RNA template (monomer), while the other is a hairpin dimer RNA synthesized by a "copy-back" mechanism. Substantial evidence derived from several experiments demonstrated that the RNA monomer was synthesized through de novo initiation by NS5B rather than by a terminal transferase activity. Synthesis of the RNA monomer requires all four ribonucleotides. The RNA monomer product was verified to be the result of de novo RNA synthesis, as two expected RNA products were generated from monomer RNA by RNase H digestion. In addition, modification of the RNA template by the addition of the chain terminator cordycepin at the 3' end did not affect synthesis of the RNA monomer but eliminated synthesis of the self-priming hairpin dimer RNA. Moreover, synthesis of RNA on poly(C) and poly(U) homopolymer templates by 1b-42 NS5B did not require the oligonucleotide primer at high concentrations (>/=50 microM) of GTP and ATP, further supporting a de novo initiation mechanism. These findings suggest that HCV NS5B is able to initiate RNA synthesis de novo.
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Affiliation(s)
- G Luo
- Department of Virology, Bristol-Myers Squibb Pharmaceutical Research Institute, Wallingford, Connecticut 06492-7660, USA.
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167
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Wang J, Sun S, Luo G, Wang Y, Wang Y, Wang J. [Analysis of blue ballpoint ink components by FT-IR microspectrometry]. Guang Pu Xue Yu Guang Pu Fen Xi 1999; 19:834-836. [PMID: 15822311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Systematical analysis on the 108 kinds of blue ballpoint writing inks with FT-IR microspectrometry is presented in this paper. The results show that the differences of the ink compounds keep some regular. These blue ballpoint writing inks can be classified by the transmittance spectra. The method is rapid, accurate, highly sensitive and nondestructive.
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Affiliation(s)
- J Wang
- Department of Chemistry, Tsinghua University, 100084 Beijing
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168
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Abstract
An important molecule involved in delivering the death signal that initiates apoptosis is called Fas, or Apo-1, which sits on the cell surface. When another molecule called the Fas ligand (FasL) binds to it, Fas triggers a series of events inside the cell that leads to apoptosis. In order to investigate the mechanism of immune escape and the expression of Fas and FasL in oral premalignant lesions (OPLs) and oral squamous cell carcinomas (OSCCs), a total of 64 samples were evaluated by an immunohistochemical method using a labelled streptavidin-biotin assay. These samples comprised nine hyperkeratotic and 24 oral premalignant lesions (nine of mild, moderate, and six of severe dysplastic lesions), and 24 OSCCs, together with seven healthy controls. The results demonstrated that the majority of invasive OSCCs showed down-regulation of Fas expression but up-regulation of FasL expression. These phenomena were also detected in OPLs. The results indicate that the expression of Fas and FasL is involved in oral carcinogenesis and this may be a mechanism by which the cancer cells evade the host immune assault. Perhaps, in future, Fas/FasL system may be used as a prognostic biomarker in predicting the behavior of oral premalignant lesions.
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Affiliation(s)
- Q Chen
- Oral Bio-Science Laboratories, Faculty of Dentistry, The University of Hong Kong, Hong Kong.
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169
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Wu Z, Luo G, Huo Y, Zhong X. [TLC-identification of radix Rehmanniae and its mixed medicinal materials in Pharmacopoeia]. Zhong Yao Cai 1999; 22:499-502. [PMID: 12571911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
In 237 kinds of medicinal meterials included 71 kinds of Chinese patent medicines composed in Pharmacopoeia such as Liuweidihuang Pills, character identify constituent of Radix Rehmanniae was found by TLC, and was successed to use to identification of Radix Rehmanniae in 10 kinds of Chinese patent medicines such as Liuweidihuang Pills.
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Affiliation(s)
- Z Wu
- Foshan Institute for Drug Control, Foshan 528000
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170
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Yu KL, Ruediger E, Luo G, Cianci C, Danetz S, Tiley L, Trehan AK, Monkovic I, Pearce B, Martel A, Krystal M, Meanwell NA. Novel quinolizidine salicylamide influenza fusion inhibitors. Bioorg Med Chem Lett 1999; 9:2177-80. [PMID: 10465540 DOI: 10.1016/s0960-894x(99)00361-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
A novel series of quinolizidine salicylamides was synthesized as specific inhibitors of the H1 subtype of influenza A viruses. These inhibitors inhibit the pH-induced fusion process, thereby blocking viral entry into host cells. Compound 16 was the most active inhibitor in this series with an EC50 of 0.25 microg/mL in plaque reduction assay. The synthesis and the SAR of these compounds are discussed.
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Affiliation(s)
- K L Yu
- Bristol-Myers Squibb Pharmaceutical Research Institute, Department of Chemistry, Wallingford, CT 06492, USA
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171
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Nie M, Li B, Zeng G, He Z, Chen Q, Zhou M, Luo G, Zeng X. [Changes of simple epithelial cytokeratin during oral carcinogenesis]. Hua Xi Kou Qiang Yi Xue Za Zhi 1999; 17:208-9, 220. [PMID: 12539284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To investigate whether the simple epithelial cytokeratin CK18 and CK19 can be used as a marker of oral precancerous lesions. METHODS Formalin-fixed, paraffin-embedded tissue sections of normal oral mucosa, epithelial hyperplasia, mild epithelial dysplasia, moderate epithelial dysplasia, severe epithelial dysplasia and oral squamous cell carcinomas were stained with a CK18-specific antibody and CK19-specific antibody respectively by LSAB immunohistochemical method. The stained sections were observed under light microscopy. The results were described and analyzed with Rank Sum Test. RESULTS CK18 was not detected in normal and abnormal oral tissue sections. But in normal nonkeratinized mucosa, CK19 was detected in the basal cell layer dispersively. In epithelial dysplasia, CK19 was detected in the suprabasal cell layer and the number of CK19-positive cell layers was correlated with the dysplasia degree of epithelia. Furthermore, CK19 was detected in oral squamous cell carcinoma, especially in the poor-differentiated cancer cells. CONCLUSION CK19 expression in suprabasal cell layer of oral mucosa can be used as a candidate marker for diagnosis of oral precancerous lesions and determination of the differentiation level of oral squamous cell carcinoma.
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Affiliation(s)
- M Nie
- College of Stomatology, West China University of Medical Sciences
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172
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Williams AB, Decourten-Myers GM, Fischer JE, Luo G, Sun X, Hasselgren PO. Sepsis stimulates release of myofilaments in skeletal muscle by a calcium-dependent mechanism. FASEB J 1999; 13:1435-43. [PMID: 10428767 DOI: 10.1096/fasebj.13.11.1435] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Sepsis is associated with a pronounced catabolic response in skeletal muscle, mainly reflecting degradation of the myofibrillar proteins actin and myosin. Recent studies suggest that sepsis-induced muscle proteolysis may reflect ubiquitin-proteasome-dependent protein breakdown. An apparently conflicting observation is that the ubiquitin-proteasome pathway does not degrade intact myofibrils. Thus, it is possible that actin and myosin need to be released from the myofibrils before they can be ubiquitinated and degraded by the proteasome. We tested the hypothesis that sepsis results in disruption of Z-bands, increased expression of calpains, and calcium-dependent release of myofilaments in skeletal muscle. Sepsis induced in rats by cecal ligation and puncture resulted in increased gene expression of micro-calpain, m-calpain, and p94 and in Z-band disintegration in the extensor digitorum longus muscle. The release of myofilaments from myofibrillar proteins was increased in septic muscle. This response to sepsis was blocked by treating the rats with dantrolene, a substance that inhibits the release of calcium from intracellular stores to the cytoplasm. The present results provide evidence that sepsis is associated with Z-band disintegration and a calcium-dependent release of myofilaments in skeletal muscle. Release of myofilaments may be an initial and perhaps rate-limiting component of sepsis-induced muscle breakdown.
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Affiliation(s)
- A B Williams
- Departments of Surgery and Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio 45267-0558, USA
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173
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Wang Q, Luo G, Ou J, Yeung WS. Noncompetitive immunoassays using protein G affinity capillary chromatography and capillary electrophoresis with laser-induced fluorescence detection. J Chromatogr A 1999; 848:139-48. [PMID: 10427754 DOI: 10.1016/s0021-9673(99)00413-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A new and simple approach to perform immunoassay using protein G affinity capillary chromatography and laser-induced fluorescence detection was described. A noncompetitive assay for monoclonal anti-bovine serum albumin (BSA) was used to test the performance of the system. Fluorescein isothiocyanate labeled BSA was used as a tracer to determine anti-BSA in pM level. Capillaries with inner diameter of 150 microns were packed with recombinant protein G-bound perfusive support. The packed capillary was used to capture the immunocomplexes, which were subsequently desorbed by 100 mM glycine (pH 9.0). Open tube capillary electrophoresis-based immunoassay (CEIA) for anti-BSA was also performed. Using standard samples, calibration curves for anti-BSA was established in both assays. Compared with CEIA, this system improved the concentration sensitivity for about 100-fold due to the pre-concentration of immunocomplex in the protein G column, while the mass sensitivity was similar in the two methods.
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Affiliation(s)
- Q Wang
- Department of Chemistry, Tsinghua University, Beijing, China
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174
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Luo G, Cianci C, Harte W, Krystal M. Conquering influenza: recent advances in anti-influenza drug discovery. IDrugs 1999; 2:671-85. [PMID: 16127638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Morbidity and mortality associated with influenza virus infection have cut a wide swathe through medical history. Even with the development of killed virus vaccines, illness due to influenza virus infection continues to be a major health problem throughout the world. This may change over the next few years with the development of a new class of antiviral agents targeting the catalytic site of the viral neuraminidase enzyme. These agents have been demonstrated to be both efficacious and clinically beneficial. In addition, investigation into alternative anti-influenza targets continues. These include inhibitors of hemagglutinin-mediated functions, the viral polymerase and new inhibitors of M2 ion channel activity.
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Affiliation(s)
- G Luo
- Department of Virology, Bristol-Myers Squibb Pharmaceuticals Research Institute, 5 Research Parkway, Wallingford, CT 06492, USA
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175
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Luo G, Yao MS, Bender CF, Mills M, Bladl AR, Bradley A, Petrini JH. Disruption of mRad50 causes embryonic stem cell lethality, abnormal embryonic development, and sensitivity to ionizing radiation. Proc Natl Acad Sci U S A 1999; 96:7376-81. [PMID: 10377422 PMCID: PMC22093 DOI: 10.1073/pnas.96.13.7376] [Citation(s) in RCA: 298] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Mre11/Rad50 protein complex functions in diverse aspects of the cellular response to double-strand breaks (DSBs), including the detection of DNA damage, the activation of cell cycle checkpoints, and DSB repair. Whereas genetic analyses in Saccharomyces cerevisiae have provided insight regarding DSB repair functions of this highly conserved complex, the implication of the human complex in Nijmegen breakage syndrome reveals its role in cell cycle checkpoint functions. We established mRad50 mutant mice to examine the role of the mammalian Mre11/Rad50 protein complex in the DNA damage response. Early embryonic cells deficient in mRad50 are hypersensitive to ionizing radiation, consistent with a role for this complex in the repair of ionizing radiation-induced DSBs. However, the null mrad50 mutation is lethal in cultured embryonic stem cells and in early developing embryos, indicating that the mammalian Mre11/Rad50 protein complex mediates functions in normally growing cells that are essential for viability.
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Affiliation(s)
- G Luo
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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176
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Luo G, Kaufman JJ, Chiabrera A, Bianco B, Kinney JH, Haupt D, Ryaby JT, Siffert RS. Computational methods for ultrasonic bone assessment. Ultrasound Med Biol 1999; 25:823-830. [PMID: 10414899 DOI: 10.1016/s0301-5629(99)00026-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Ultrasound has been proposed as a means to noninvasively assess bone and, particularly, bone strength and fracture risk. Although there has been some success in this application, there is still much that is unknown regarding the propagation of ultrasound through bone. Because strength and fracture risk are a function of both bone mineral density and architectural structure, this study was carried out to examine how architecture and density interact in ultrasound propagation. Due to the difficulties inherent in obtaining fresh bone specimens and associated architectural and density features, simulation methods were used to explore the interactions of ultrasound with bone. A sample of calcaneal trabecular bone was scanned with micro-CT and subjected to morphological image processing (erosions and dilations) operations to obtain a total of 15 three-dimensional (3-D) data sets. Fifteen two-dimensional (2-D) slices obtained from the 3-D data sets were then analyzed to evaluate their respective architectures and densities. The architecture was characterized through the fabric feature, and the density was represented in terms of the bone volume fraction. Computer simulations of ultrasonic propagation through each of the 15 2-D bone slices were carried out, and the ultrasonic velocity and mean frequency of the received waveforms were evaluated. Results demonstrate that ultrasound propagation is affected by both density and architecture, although there was not a simple linear correlation between the relative degree of structural anisotropy with the ultrasound measurements. This study elucidates further aspects of propagation of ultrasound through bone, and demonstrates as well as the power of computational methods for ultrasound research in general and tissue and bone characterization in particular.
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Affiliation(s)
- G Luo
- New York Department of Veterans Affairs Medical Center and Department of Rehabilitation Medicine, New York University Medical Center, NY, USA
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177
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Luo G, Herrera AH, Horowits R. Molecular interactions of N-RAP, a nebulin-related protein of striated muscle myotendon junctions and intercalated disks. Biochemistry 1999; 38:6135-43. [PMID: 10320340 DOI: 10.1021/bi982395t] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
N-RAP is a recently discovered muscle-specific protein that is concentrated at the myotendon junctions in skeletal muscle and at the intercalated disks in cardiac muscle. The C-terminal half of N-RAP contains a region with sequence homology to nebulin, while a LIM domain is found at its N-terminus. N-RAP is hypothesized to perform an anchoring function, linking the terminal actin filaments of myofibrils to protein complexes located beneath the sarcolemma. We used a solid-phase assay to screen myofibrillar and junctional proteins for binding to several recombinant fragments of N-RAP, including the nebulin-like super repeat region (N-RAP-SR), the N-terminal half including the LIM domain (N-RAP-NH), and the region of N-RAP between the super repeat region and the LIM domain (N-RAP-IB). Actin is the only myofibrillar protein tested that exhibits specific binding to N-RAP, with high-affinity binding to N-RAP super repeats, and 10-fold weaker binding to N-RAP-IB. In contrast, myosin, isolated myosin heads, tropomyosin, and troponin exhibited no specific interaction with N-RAP domains. A recombinant fragment corresponding to the C-terminal one-fourth of vinculin also binds specifically to N-RAP super repeats, while no specific N-RAP binding activity was observed for other regions of the vinculin molecule. Finally, talin binds with high affinity to the LIM domain of N-RAP. These results support our hypothesis that N-RAP is part of a complex of proteins that anchors the terminal actin filaments of the myofibril to the membrane, and functions in transmitting tension from the myofibrils to the extracellular matrix.
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Affiliation(s)
- G Luo
- Laboratory of Physical Biology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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178
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Chen Q, Luo G, Li B, Samaranayake LP. Expression of p16 and CDK4 in oral premalignant lesions and oral squamous cell carcinomas: a semi-quantitative immunohistochemical study. J Oral Pathol Med 1999; 28:158-64. [PMID: 10235368 DOI: 10.1111/j.1600-0714.1999.tb02016.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The protein, p16, the product of cyclin-dependent kinase number 2 (CDKN2) gene, is one of the negative regulators of the cell cycle. CDK4, encoded by CDK4 gene, is the substrate of p16. We investigated the expression of p16 and CDK4 and their role in the progression of oral premalignant lesions (OPLs) and oral squamous cell carcinomas (OSCCs) in a Chinese cohort. A total of 74 samples were obtained from patients with hyperkeratosis (10), OPLs [30; mild (10), moderate (10) and severe (10) dysplastic lesions], OSCCs (15; 8 non-metastatic, 7 metastatic), and normal oral tissues (10), together with local lymph nodes (9) of patients with metastatic OSCCs. A labelled streptavidin biotin (LSAB) immunohistochemistry assay was performed and a semi-quantitative method was used to evaluate the staining intensity. The staining patterns of p16 and CDK4 were similar in all tissues and were located in both the nuclei and the cytoplasm. However, the antigen distribution characteristics and the degree of expression of both p16 and CDK4 varied at different developmental stages of the lesions. Hyperkeratotic and dysplastic lesions tended to display a progressively increasing degree of p16- and CDK4-positive nuclei as compared with normal tissues. Also, positive staining cytoplasm was highly evident in OSCCs with a very low nuclear staining (P<0.05). Forty-six of 56-, p16-positive cases were CDK4-positive, while only 6 were CDK4-positive but p16-negative, implying a high correlation between these parameters (r=0.813, P<0.001). This study indicates that the expression of p16 and CDK4 is intimately involved in the development of OPLs and OSCCs and the likely existence of a positive feedback loop between p16 and CDK4.
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Affiliation(s)
- Q Chen
- Laboratory of Oral Mucosal Diseases, College of Stomatology, West China University of Medical Sciences, Chengdu, PR China
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179
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Abstract
UV cross-linking analyses were performed in an attempt to determine cellular protein-viral RNA interactions with the 3' untranslated region (3' UTR) of the hepatitis C virus RNA genome. Two cellular proteins, with estimated molecular masses of 58 kDa (p58) and 35 kDa (p35), respectively, were found to specifically bind to the 3' UTR. The p58 protein was determined to be the polypyrimidine tract-binding protein. In addition to binding to the conserved 98 nucleotides (nt) of the 3' UTR, p58 also binds to the poly(U) tract of the 3' UTR. The p35 protein was found to interact only with the poly(U) tract of the 3' UTR. These conclusions are supported by the following findings: (1) p58, and not p35, binds to the 3' end conserved 98 nt, (2) both p58 and p35 bind to a 3' UTR RNA with a deletion of the conserved 98 nt, (3) the 98-nt deletion mutant 3' UTR competed out both p58 and p35 binding, (4) a poly(U) homopolymer competed out both p58 and p35 binding, (5) a 3' UTR RNA with deletion of the poly(U) tract competed out only p58 binding but not p35 binding, and (6) an RNA containing the variable region of the 3' UTR with a deletion of both poly(U) tract and 98 nt failed to compete for binding of either p58 or p35. Interaction of these cellular proteins with the HCV 3' UTR is probably involved in regulation of translation and/or replication of the HCV RNA genome.
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Affiliation(s)
- G Luo
- Department of Virology, Bristol-Myers Squibb Pharmaceutical Research Institute, 5 Research Parkway, Wallingford, Connecticut 06492, USA.
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180
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Luo G, Sadegh AM, Alexander H, Jaffe W, Scott D, Cowin SC. The effect of surface roughness on the stress adaptation of trabecular architecture around a cylindrical implant. J Biomech 1999; 32:275-84. [PMID: 10093027 DOI: 10.1016/s0021-9290(98)00172-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The effect of implant-bone bonding and the effect of implant surface roughness on bone remodeling near the bone-implant interface were studied by using a surface remodeling theory and the boundary element method. The study has shown that implant attachment plays an important role in bone remodeling near the implant. It has been observed in animal experiments and in clinical situations that the remodeled trabecular bone architecture around a cylindrical implant could vary, on one hand, from a hub surrounding the implant with a set of external spokes to, on the other hand, a hubless situation in which a set of spokes attach directly to the implant. It is shown here that the difference in these structures may be attributed to differences in implant attachment. The results show that the bone with perfect bonding or roller boundary condition without a gap remodeled to a hubless spoke trabecular bone architecture. On the other hand, the roller boundary condition with a specified gap yielded a spoke trabecular architecture with a hub or ring surrounding the implant. These quantitative results mirror the experimental and clinical observations. It is concluded that the hub is a consequence of the gap and not a consequence of the lack of friction between the implant and the bone.
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Affiliation(s)
- G Luo
- Department of Mechanical Engineering, School of Engineering, City College, New York, NY, USA
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181
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Cianci C, Yu KL, Dischino DD, Harte W, Deshpande M, Luo G, Colonno RJ, Meanwell NA, Krystal M. pH-dependent changes in photoaffinity labeling patterns of the H1 influenza virus hemagglutinin by using an inhibitor of viral fusion. J Virol 1999; 73:1785-94. [PMID: 9971755 PMCID: PMC104417 DOI: 10.1128/jvi.73.3.1785-1794.1999] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/1998] [Accepted: 12/01/1998] [Indexed: 11/20/2022] Open
Abstract
The hemagglutinin (HA) protein undergoes a low-pH-induced conformational change in the acidic milieu of the endosome, resulting in fusion of viral and cellular membranes. A class of compounds that specifically interact with the HA protein of H1 and H2 subtype viruses and inhibit this conformational change was recently described (G. X. Luo et al., Virology 226:66-76, 1996, and J. Virol. 71:4062-4070, 1997). In this study, purified HA trimers (bromelain-cleaved HA [BHA]) are used to examine the properties and binding characteristics of these inhibitors. Compounds were able to inhibit the low-pH-induced change of isolated trimers, as detected by resistance to digestion with trypsin. Protection from digestion was extremely stable, as BHA-inhibitor complexes could be incubated for 24 h in low pH with almost no change in BHA structure. One inhibitor was prepared as a radiolabeled photoaffinity analog and used to probe for specific drug interactions with the HA protein. Analysis of BHA after photoaffinity analog binding and UV cross-linking revealed that the HA2 subunit of the HA was specifically radiolabeled. Cross-linking of the photoaffinity analog to BHA under neutral (native) pH conditions identified a stretch of amino acids within the alpha-helix of HA2 that interact with the inhibitor. Interestingly, cross-linking of the analog under acidic conditions identified a different region within the HA2 N terminus which interacts with the photoaffinity compound. These attachment sites help to delineate a potential binding pocket and suggest a model whereby the BHA is able to undergo a partial, reversible structural change in the presence of inhibitor compound.
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Affiliation(s)
- C Cianci
- Departments of Virology, Bristol-Myers Squibb Pharmaceutical Research Institute, Wallingford, Connecticut 06492, USA
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182
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Herrington J, Rui L, Luo G, Yu-Lee LY, Carter-Su C. A functional DNA binding domain is required for growth hormone-induced nuclear accumulation of Stat5B. J Biol Chem 1999; 274:5138-45. [PMID: 9988763 DOI: 10.1074/jbc.274.8.5138] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mechanisms regulating the cellular distribution of STAT family transcription factors remain poorly understood. To identify regions of Stat5B required for ligand-induced nuclear accumulation, we constructed a cDNA encoding green fluorescent protein (GFP) fused to the N terminus of Stat5B and performed site-directed mutagenesis. When co-expressed with growth hormone (GH) receptor in COS-7 cells, GFP-Stat5B is tyrosyl-phosphorylated, forms dimers, and binds DNA in response to GH in a manner indistinguishable from untagged Stat5B. In multiple cell types, laser scanning confocal imaging of GFP-Stat5B co-expressed with GH receptor shows that GFP-Stat5B undergoes a rapid, dramatic accumulation in the nucleus upon GH stimulation. We introduced alanine substitutions in several regions of Stat5B and assayed for GH-dependent nuclear localization. Only the mutation that prevented binding to DNA (466VVVI469) abrogated GH-stimulated nuclear localization. This mutant fusion protein is tyrosyl-phosphorylated and dimerizes in response to GH. These results suggest that either high affinity binding to DNA contributes to nuclear accumulation of Stat5B or that this region is crucial for two functions, namely accumulation of Stat5B in the nucleus and DNA binding. Thus, we have identified a mutant Stat5 defective in nuclear localization despite its ability to be tyrosyl-phosphorylated and to dimerize.
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Affiliation(s)
- J Herrington
- Department of Physiology, University of Michigan Medical School, Ann Arbor, Michigan 48109-0622, USA
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183
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Chen Q, Luo G, Li B, He Z, Chen L, Cao X, Nie M. [Expression of CDK4 protein in oral carcinogenesis]. Hua Xi Kou Qiang Yi Xue Za Zhi 1999; 17:8-10. [PMID: 12539309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To study the expression of cyclin dependent kinase 4(CDK4) protein in oral carcinogenesis. METHODS An LSAB immunohistochemistry method was applied to 80 cases of paraffine-fixed tissues to study the expression and distribution of CDK4 in normal oral mucosa, oral premalignant lesion (OPL) and oral squamous cell carcinoma. RESULTS The overexpression of CDK4 protein was observed in the progression of OPL. Meanwhile, a correlation analysis was applied to investigate the relationship between P16 and CDK4 expression, and the result showed that the coefficient of correlation was 0.813, which was statistically significant. CONCLUSION The overexpression of CDK4 is involved in the progression of OPL, and there is a positive feedback loop between CDK4 and P16.
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Affiliation(s)
- Q Chen
- Department of Oral Medicine, College of Stomatology, West China University of Medical Sciences
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184
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Wang Q, Luo G, Xu W, Duan M. [Analysis of rice leaf proteins induced by Magnaporthe grisae with capillary zone electrophoresis]. Se Pu 1999; 17:61-3. [PMID: 12548832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Abstract
Intercellular and intracellular proteins which were extracted from rice seedling leaves induced by Magnaporthe grisae, as well as those of control, were analysed by capillary zone electrophoresis. Intercellular proteins were extracted with sterilized water, while intracellular proteins were extracted with acidic protein extraction buffer. Protein adsorption to capillary wall was suppressed by using linear polyacrylamide coated capillary (75 microns x 57 cm) instead of uncoated capillary. Separations were performed at 25 degrees C with a positive voltage of 20 kV. Samples were injected into the capillary by applying pressure (3.0 kPa) for 5 s. The running buffer consisted of 50 mmol/L phosphoric acid (pH 2.0), and detection was achieved at 200 nm with a diode array detector. Being compared with a control, a new kind of protein induced by Magnaporthe grisae was identified in rice leaf intracellular proteins with Grubbs method which is used to test outliers in mathematical statistics.
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Affiliation(s)
- Q Wang
- Department of Chemistry, Tsinghua University, Beijing, 100084
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185
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Luo G, Kinney JH, Kaufman JJ, Haupt D, Chiabrera A, Siffert RS. Relationship between plain radiographic patterns and three- dimensional trabecular architecture in the human calcaneus. Osteoporos Int 1999; 9:339-45. [PMID: 10550451 DOI: 10.1007/s001980050156] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The purpose of this study was to determine the relationship between three-dimensional (3D) trabecular structure and two-dimensional plain radiographic patterns. An in vitro cylinder of human calcaneal trabecular bone was three-dimensionally imaged by micro-CT using synchrotron radiation, at 33.4 micrometer resolution. The original 3D image was processed using 14 distinct sequences of morphologic operations, i.e., of dilations and erosions, to obtain a total of 15 3D models or images of calcaneal trabecular bone. These 15 models had distinct densities (volume fractions) and architectures. The 3D structure of each calcaneal model was assessed using mean intercept length (fabric), by averaging individual fabric measurements associated with each medial-lateral image slice, and determining the relative anisotropy, R(3D), of the structure. A summated pattern or plain radiograph was also computed from the 3D image data for each calcaneal model. Each summated pattern was then locally thresholded, and the resulting two-dimensional (2D) binary image analyzed using the same fabric analysis as used for the 3D data. The anisotropy of the 2D summated pattern was denoted by R(x-ray). The volume fractions of the 15 models ranged from 0.08 to 0.19 with a mean of 0. 14. The medial-lateral anisotropies, R(3D), ranged from 1.38 to 2.54 with a mean of 1.88. The anisotropy of the 2D summated patterns, R(x-ray), ranged from 1.35 to 2.18 with a mean of 1.71. The linear correlation of the 3D trabecular architecture, R(3D), with the radiographic trabecular architecture, R(x-ray), was 0.99 (p<0.0001). This study shows that the plain radiograph contains architectural information directly related to the underlying 3D structure. A well-controlled sequential reproducible plain radiograph may prove useful for monitoring changes in trabecular architecture in vivo and in identifying those individuals at increased risk of osteoporotic fracture.
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Affiliation(s)
- G Luo
- New York Department of Veterans Affairs Medical Center, New York, and Department of Rehabilitation Medicine, New York University Medical Center, New York, New York, USA
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186
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Abstract
Using two different glutathione derivatives as hapten, we have prepared two abzymes, which display glutathione peroxidase (GPX) activity. Their GPX activities are 0.2 and 1.6 times that of natural GPX from rabbit liver, respectively. Selenium content analysis indicates that the activity difference between the two abzymes is possibly attributed to the conformation difference of the abzymes.
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Affiliation(s)
- G Luo
- National Laboratory of Enzyme Engineering, Jilin University, Changchun, China
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187
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188
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Luo G. A General Formulation for Unidimensional Unfolding and Pairwise Preference Models: Making Explicit the Latitude of Acceptance. J Math Psychol 1998; 42:400-417. [PMID: 9917423 DOI: 10.1006/jmps.1998.1206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Probabilistic unfolding models for direct responses of persons to statements are characterised by single peaked response functions. The range in which a positive response is most likely is termed the latitude of acceptance, a well known but little researched concept in the modelling of attitude measurement. This paper derives a general form for probabilistic unfolding models in which a natural parameter characterises the latitude of acceptance. It is shown that a number of already known models for unfolding can be reexpressed in this general form with different operational functions and that, in doing so, the implied latitude of acceptance for these models is identified. It is also shown that other unfolding models can be generated readily by specifying the operational function of the general form. A general form for pairwise preference models is also presented. A discussion on the latitude of acceptance parameter as a scale parameter is also provided. Copyright 1998 Academic Press.
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Affiliation(s)
- G Luo
- South China Normal University, Guangzhou, China
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189
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Chen Q, Luo G, Li B. [The inhibitory effect of wild-type p53 gene on the growth and proliferation of lingual squamous cell carcinoma cell line Tca8113 in nude mice]. Hua Xi Yi Ke Da Xue Xue Bao 1998; 29:379-82. [PMID: 10743232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The aim of this study was to observe the growth and proliferation of the Tca8113 cell line in nude mice after the wild-type p53 gene has been transfered by electroporation. The experiment consisted of four groups: the wild-type p53 gene, blank control plasmid, the mutant p53 gene, and blank control into which no gene was transfered. After the gene was transfected, the cells were planted into 16 nude mice respectively. When the tumor formed, the nude mice were killed and the tumors were studied by regular pathology, stereology and immunohistochemistry. The results showed that in the wild-type p53 gene group, the tumors weighed less heavy, the pathological mitosis decreased markedly, and stereologically, the ratio of the area of necrosis to the total tumorous area was smaller. Similarly, the count of the proliferation cell nuclear antigen in non-necrotic area went down. The above findings were statistically significant (P < 0.05). These indicate that when the tumor cells re-obtain the well functional exogenic wild-type p53 gene, the gene expresses and produces new negative cell-growth regulator to replace the abnormal regulation system partially, then the growth and proliferation of the tumors can be inhibited; therefore, it is suggested that the p53 tumor suppressor gene may possibly be used as a gene therapy agent to treat oral squamous cell carcinoma.
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Affiliation(s)
- Q Chen
- Lab. of Oral Mucosal Diseases, School of Stomatology, Chengdu
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190
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Luo G, Tan X, Luo H. [Studies on the biological and clinical characteristics of acquired pneumonia caused by K. planticola]. Zhonghua Jie He He Hu Xi Za Zhi 1998; 21:661-3. [PMID: 11477892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
OBJECTIVE To investigate the characteristics of biological, and clinical epidemiology of acquired pneumonia caused by a new type of Klebsiella, K. planticola. METHOD 9 strains of K. planticola were isolated from respiratory samples of patients, in vitro, biological and serologic identification were done, in vivo, infected animal models were also evaluated. Clinical epidemiological inquiries were also performed. RESULT 9 strains' biological features were different from those of the other Klebsiella. The 9 patients' ages were over forty and the primary disease was the third type tuberculosis of lungs. Using of antituberculosis drugs for long term as well as penicillins might be the predisposing factors, corticosteroids were used in 3 of the 9 patients, Combined infection with other pathogens in addition to K. planticola occurred in 8 patients, in 7/8, Candida albicans was identified. Drug sensitive tests show that all of them were resistant to penicillins and sensitive to the second and third generation cephalosporins. CONCLUSION The new strain of Klebsiella was studied and this information will be useful for diagnosing and treating K. platicola.
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Affiliation(s)
- G Luo
- Second Hospital of Jing Zhou, Jing Zhou 434000
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191
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Abstract
The peptide hormones, prolactin (PRL) and growth hormone (GH), are known to regulate numerous target tissues. Among such targets are cells of the immune system, including T cells, B cells, macrophages and natural killer cells. We have cloned a panel of PRL- and GH-inducible T cell genes for use in studies to understand how these hormones through the expression of these genes modulate the biology of immune function cells. This article focuses on the signalling pathways emanating from the PRL receptor (PRL-R) and GH receptor (GH-R), and the expression of PRL-inducible target genes.
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Affiliation(s)
- L Yu-Lee
- Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, USA.
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192
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Luo G, Ivics Z, Izsvák Z, Bradley A. Chromosomal transposition of a Tc1/mariner-like element in mouse embryonic stem cells. Proc Natl Acad Sci U S A 1998; 95:10769-73. [PMID: 9724779 PMCID: PMC27970 DOI: 10.1073/pnas.95.18.10769] [Citation(s) in RCA: 185] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/1998] [Indexed: 11/18/2022] Open
Abstract
Mouse has become an increasingly important organism for modeling human diseases and for determining gene function in a mammalian context. Unfortunately, transposon-tagged mutagenesis, one of the most valuable tools for functional genomics, still is not available in this organism. On the other hand, it has long been speculated that members of the Tc1/mariner-like elements may be less dependent on host factors and, hence, can be introduced into heterologous organisms. However, this prediction has not been realized in mice. We report here the chromosomal transposition of the Sleeping Beauty (SB) element in mouse embryonic stem cells, providing evidence that it can be used as an in vivo mutagen in mice.
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Affiliation(s)
- G Luo
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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193
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Luo G, Zeldin DC, Blaisdell JA, Hodgson E, Goldstein JA. Cloning and expression of murine CYP2Cs and their ability to metabolize arachidonic acid. Arch Biochem Biophys 1998; 357:45-57. [PMID: 9721182 DOI: 10.1006/abbi.1998.0806] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Five murine cytochrome P450 (CYP) 2C cDNAs were cloned and characterized, including four new members of this subfamily: CYP2C37, CYP2C38, CYP2C39, and CYP2C40. The cDNAs ranged from 1716 to 1812 bp in length and encoded polypeptides of 490 amino acid residues except for CYP2C40, which contained an additional glutamic acid residue at the carboxyl terminus. The amino acid identity of the murine CYP2Cs ranged from 69 to 92%, while the overall amino acid identity was 60%; however, within the six putative substrate recognition sites the identity was only 25 to 41%, suggesting possible differences in substrate specificity and product profiles. The CYP2C cDNAs were expressed in Escherichia coli following modification of the N-terminus. All five recombinant CYP2Cs metabolized arachidonic acid, but with different metabolic profiles and catalytic rates. Based on coelution with authentic standards on reverse-phase HPLC, themajor metabolites were tentatively identified asfollows: CYP2C29 and CYP2C39 produced 14, 15-cis-epoxyeicosatrienoic acid (EET); CYP2C37 produced 12-hydroxyeicosatetraenoic acid (HETE); CYP2C38 produced 11,12-EET; and CYP2C40 produced an unidentified metabolite that coeluted with 16-,17-, and 18-HETEs. The turnover numbers for CYP2C29, CYP2C37, CYP2C38, CYP2C39, and CYP2C40 were 0.34, 1.12, 5.15, 0.51, and 0.15 nmol/nmol/min, respectively. Reverse transcriptase-polymerase chain reaction demonstrated the presence of CYP2C29 mRNA in liver as well as in extrahepatic tissues including brain, kidney, lung, heart, and intestine. CYP2C38 and CYP2C40 were found in liver, brain, kidney, and intestine, with trace amounts in lung and heart, while CYP2C37 and CYP2C39 appeared to be liver specific.
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Affiliation(s)
- G Luo
- Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina 27709, USA
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194
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Wu Z, Luo G, Huo Y. [TLC identification of Flos Carthami]. Zhong Yao Cai 1998; 21:441-4. [PMID: 12569834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
In 137 kinds of medicinal meterials included 21 kinds of traditional Chinese patent medicines in Pharmacopoeia such as Qili Powder, character identified constituent of Flos Carthami was found by TLC, and was successful to be used to identification of Flos Carthami in 9 kinds of traditional Chinese patent meicines such as Qili Powder.
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Affiliation(s)
- Z Wu
- Foshan Institute for Drug Control, Foshan 528000
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195
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Luo G, Xie ZZ, Liu FY, Zhang GB. Effects of vitamin C on myocardial mitochondrial function and ATP content in hypoxic rats. Zhongguo Yao Li Xue Bao 1998; 19:351-5. [PMID: 10375783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
AIM To observe the effects of large dose of vitamin C (Vc) on myocardial mitochondrial function, ATP content, and myocardial structure in acute and chronic hypoxic rats. METHODS Rats were exposed to a simulated altitude 4000 m (barometric pressure = 43 kPa) for 3 and 30 d. Vc (0.75 g.kg-1.d-1) was injected i.p. The heart mitochondrial respiratory function were determined by Clark-type O2 electrode; mitochondrial membrane fluidity (MMF) were assayed through fluorescence polarizative method; the contents of ATP, ADP, and AMP in myocardial tissue were measured with HPLC. RESULTS After administration of Vc, the ATP content was increased from 35 +/- 3 mg.g-1 to 53 +/- 3 mg.g-1 in acute hypoxic rats (P < 0.01), from 42 +/- 4 mg.g-1 to 48 +/- 3 mg.g-1 in chronic hypoxic rats (P < 0.01); Pa, O2 was increased from 7.2 +/- 1.4 kPa to 9.5 +/- 1.2 kPa in acute hypoxic rats (P < 0.01); mitochondrial respiratory control rate (RCR) was increased from 2.1 +/- 0.6 to 4.7 +/- 0.5 in acute hypoxic rats (P < 0.01), and from 3.3 +/- 0.7 to 4.5 +/- 0.6 in chronic hypoxic rats (P < 0.01); MMF was increased in acute and chronic hypoxic rats (P < 0.05); the degree of myocardial necrosis in vitamin C preventive rats was attenuated as compared with those of acute hypoxic rats. CONCLUSION Vc is effective on improving myocardial energy metabolism and protecting against myocardial structural injury in hypoxic rats.
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Affiliation(s)
- G Luo
- Institute of High Altitude Medicine, Third Military Medical University, Chongqing, China
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196
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Ding L, Liu Z, Zhu Z, Luo G, Zhao D, Ni J. Biochemical characterization of selenium-containing catalytic antibody as a cytosolic glutathione peroxidase mimic. Biochem J 1998; 332 ( Pt 1):251-5. [PMID: 9576875 PMCID: PMC1219475 DOI: 10.1042/bj3320251] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A selenium-containing catalytic antibody (Se-4A4), prepared by converting reactive serine residues of a monoclonal antibody (4A4) raised against a GSH derivative into selenocysteines, acts as a mimic of cytosolic glutathione peroxidase (cGPX). To clarify the mechanism of action of this catalytic antibody, detailed studies on kinetic behaviour and biological activity were carried out. A rate of acceleration (kcat/Km/kuncat) 10(7)-fold that of the uncatalytic reaction is observed. Under similar conditions, the turnover number (kcat) of Se-4A4 is 42% of that of the natural rabbit liver cGPX. The Se-4A4 reaction involves a Ping Pong mechanism, which is the same as that of the natural cGPX. The selenocysteine residue is located in the binding site of the antibody and is shown to be crucial for this activity. Of the thiol compounds tested, only GSH is able to serve as substrate for Se-4A4. It was demonstrated, using the free-radical-damage system (hypoxanthine/xanthine oxidase) of cardiac mitochondria, that Se-4A4 can protect mitochondria from free-radical damage at least 10(4)-fold more effectively than the natural cGPX.
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Affiliation(s)
- L Ding
- Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
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197
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Luo G, Wu L, Wu DZ. The study of local electrophysiology in macular diseases. Yan Ke Xue Bao 1998; 14:30-4. [PMID: 12580073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
PURPOSES To observe the features and clinical utility values of local electroretinogram (LERG) and local visual evoked potentials (LVEP) in macular diseases. METHODS The spot stimuli were obtained by changing the shutters with different sizes of hole at the posterior of Ganzfeld ball. The recording electrode for LERG was made with the filament of platinum as blepharophthalmostat like. The LERG and LVEP were simultaneously recorded in macular diseases. RESULTS The exudative AMD, Stargardt's disease, central serous chorioretinopathy and idiopathic macular hole had seriously decreased amplitudes of LERG and higher abnormal rates, comparing with atrophic AMD and idiopathic preretinal membranes in the region of 2.5 degrees and 5 degrees at macula. The abnormal rates in these diseases were higher for LERG than for LVEP. CONCLUSION The LERG can objectively measure the variation of macular function in maculopathies. The sensitivities of LVEP are lower than those of LERG for macular diseases.
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Affiliation(s)
- G Luo
- Zhongshan Ophthalmic Center, Sun Yat-sen University of Medical Sciences, Guangzhou 510060, China
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198
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Abstract
The peptide hormone prolactin (PRL) is known to regulate numerous target tissues. Among the less well-known targets are cells of the immune system, including T cells, B cells, and macrophages. Our laboratory has cloned a panel of PRL-inducible T-cell activation genes for use in studies investigating how PRL modulates the biology of cells of the immune system. This article focuses on two such PRL-inducible genes. One is a transcription factor called interferon regulatory factor-1, whose expression is regulated by signaling molecules along the PRL-inducible JAK/Stat signaling pathway. These signaling molecules include Stat1 and CBP as positive mediators and, unexpectedly, Stat5b as a negative mediator. A second PRL-inducible gene is c15/RNUDC, a novel nuclear movement protein, which may provide a link between PRL signaling and signaling via the lipid second messenger, platelet activating factor.
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Affiliation(s)
- L Y Yu-Lee
- Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, USA.
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199
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Luo G, Wang Y, Wang R, Wang Q. [Lecture of principles and applications of capillary electrophoresis (VI) Applications of CE in DNA analysis, carbohydrate analysis and capillary ion analysis]. Se Pu 1998; 16:38-43. [PMID: 11324477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
A review with 87 references on the application and new development of CE in DNA analysis, carbohydrate analysis and capillary ion analysis is presented. The DNA analysis included determinations of nucleotide, nucleoside and bases by CZE and MECC. It also includes dsDNA, PCR products analysis, purity control of oligonucleotide and DNA sequencing by CGE. Sometimes LIF detector needs to be introduced into DNA analysis. The carbohydrate analysis includes the methods for chemical derivatization and direct determination of carbohydrates by different CE modes. The capillary ion analysis includes the principle and determination of anions and cations.
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Affiliation(s)
- G Luo
- School of Life Science & Engineering, Tsinghua University, Beijing, 100084
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200
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Ding M, Chen P, Luo G. [Simultaneous analysis of organic acids and inorganic anions in alcoholic drink (dongjiu) by ion chromatography]. Se Pu 1998; 16:59-61. [PMID: 11324482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
An ion chromatographic method for the simultaneous analysis of organic acids and inorganic anions in Dongjiu (alcoholic drink) was developed. An anion exchange column Shim-pack IC-A1(100 mm x 4.6 mm) was used. In non-suppressed anion exchange chromatography, potassium hydrogen phthalate (KHPh) is used as eluent most widely. However, there are several problems in this eluent for the analysis of Dongjiu (alcoholic drink) sample, such as the influence of a negative peak to the determination of acetic acid, ascorbic acid and lactic acid, the non-resolution of ascorbic acid, and lactic acid, and part overlapping of the peak of acetic acid with water peak. In order to solve these problems, a mixed eluent of 0.50 mmol/L KHPh and 0.25 mmol/L phthalic acid(H2Ph) was used in this work. The main organic acids and inorganic anions in Dongjiu were separated without interference peaks. The detection limits obtained by using the mixed eluent were 0.05-0.13 mg/L, several times lower than those obtained by using single KHPh eluent. This method, being without pretreatment, is simple to operate.
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Affiliation(s)
- M Ding
- Department of Chemistry, Tsinghua University, Beijing, 100084
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