451
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Zhu G, Decker SJ, Saltiel AR. Direct analysis of the binding of Src-homology 2 domains of phospholipase C to the activated epidermal growth factor receptor. Proc Natl Acad Sci U S A 1992; 89:9559-63. [PMID: 1384057 PMCID: PMC50171 DOI: 10.1073/pnas.89.20.9559] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A number of proteins involved in intracellular signaling contain regions of homology to the product of the src oncogene that are termed Src-homology (SH) 2 domains. SH2 domains are believed to mediate the association of these proteins with various tyrosine-phosphorylated receptors in a growth factor-dependent manner. We have examined the kinetic characteristics of one of these interactions, the binding of the SH2 domains of phospholipase C gamma 1 with the receptor for epidermal growth factor (EGF). Bacterial fusion proteins were prepared containing the two SH2 domains of PLC gamma 1 and labeled metabolically with [35S]methionine/cysteine. A fusion protein containing both SH2 domains bound to the purified EGF receptor from EGF-treated cells, whereas no binding to receptors from control cells was detected. Binding was rapid, reaching apparent equilibrium by 10 min. Dissociation of the complex occurred only in the presence of excess unlabeled SH2 protein and exhibited two kinetic components. Similarly, analysis of apparent equilibrium binding revealed a nonlinear Scatchard plot, further indicating complex binding kinetics that may reflect cooperative behavior. The binding of the fusion protein containing both SH2 domains was inhibited by a fusion protein containing only the amino-terminal SH2 domain, although at concentrations an order of magnitude higher than that observed with the complete fusion protein. Fusion proteins containing SH2 domains from the GTPase-activating protein, the p85 regulatory subunit of phosphatidylinositol 3'-kinase, or the Abl oncoprotein competed less effectively. Binding of the PLC gamma 1 SH2 fusion protein to a mutant EGF receptor lacking the two carboxyl-terminal tyrosine phosphorylation sites exhibited a significantly lower affinity than that observed with the wild type, suggesting that this region of the receptor may play an important role. This binding assay represents a means with which to evaluate the pleiotropic nature of growth factor action.
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452
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Bortoletto D, Brown DN, Dominick J, McIlwain RL, Miao T, Miller DH, Modesitt M, Schaffner SF, Shibata EI, Shipsey IP, Battle M, Ernst J, Kroha H, Roberts S, Sparks K, Thorndike EH, Wang C, Sanghera S, Skwarnicki T, Stroynowski R, Artuso M, Goldberg M, Horwitz N, Kennett R, Moneti GC, Muheim F, Playfer S, Rozen Y, Rubin P, Stone S, Thulasidas M, Yao W, Zhu G, Barnes AV, Bartelt J, Csorna SE, Egyed Z, Jain V, Sheldon P, Akerib DS, Barish B, Chadha M, Cowen DF, Eigen G, Miller JS, Urheim J, Weinstein AJ, Acosta D, Masek G, Ong B, Paar H, Sivertz M, Bean A, Gronberg J, Kutschke R, Menary S, Morrison RJ, Nelson H, Richman J, Tajima H, Schmidt D, Sperka D, Witherell M, Procario M. Isospin mass splittings from precision measurements of D*-D mass differences. PHYSICAL REVIEW LETTERS 1992; 69:2046-2049. [PMID: 10046385 DOI: 10.1103/physrevlett.69.2046] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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453
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Butler F, Fu X, Kalbfleisch G, Lambrecht M, Ross WR, Skubic P, Snow J, Wang P, Bortoletto D, Brown DN, Dominick J, McIlwain RL, Miao T, Miller DH, Modesitt M, Schaffner SF, Shibata EI, Shipsey IP, Battle M, Ernst J, Kroha H, Roberts S, Sparks K, Thorndike EH, Wang C, Sanghera S, Skwarnicki T, Stroynowski R, Artuso M, Goldberg M, Horwitz N, Kennett R, Moneti GC, Muheim F, Playfer S, Rozen Y, Rubin P, Stone S, Thulasidas M, Yao W, Zhu G, Barnes AV, Bartelt J, Csorna SE, Egyed Z, Jain V, Sheldon P, Akerib DS, Barish B, Chadha M, Cowen DF, Eigen G, Miller JS, Urheim J, Weinstein AJ, Bean A, Gronberg J, Kutschke R, Menary S, Morrison RJ, Nelson HN, Richman JD, Tajima H. Measurement of the D*(2010) branching fractions. PHYSICAL REVIEW LETTERS 1992; 69:2041-2045. [PMID: 10046384 DOI: 10.1103/physrevlett.69.2041] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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454
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Zhu G, Wu LH, Mauzy C, Egloff AM, Mirzadegan T, Chung FZ. Replacement of lysine-181 by aspartic acid in the third transmembrane region of endothelin type B receptor reduces its affinity to endothelin peptides and sarafotoxin 6c without affecting G protein coupling. J Cell Biochem 1992; 50:159-64. [PMID: 1429881 DOI: 10.1002/jcb.240500206] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A conserved aspartic acid residue in the third transmembrane region of many of the G protein-coupled receptors has been shown to play a role in ligand binding. In the case of endothelin receptors, however, a lysine residue replaces this conserved aspartic acid residue. To access the importance of this residue in ligand binding, we have replaced it with an aspartic acid in the rat endothelin type B (ETb) receptor by PCR mediated mutagenesis. The binding characteristics and functional properties of both the wild type and mutant receptors were determined in COS-7 cells transiently expressing the cloned receptor cDNAs. Using 125I-ET-1 as the radioactive peptide ligand in displacement binding studies, the wild type receptor displayed a typical non-isopeptide-selective binding profile with similar IC50 values (0.2-0.6 nM) for all three endothelin peptides (ET-1, ET-2, and ET-3) and sarafotoxin 6c (SRTX 6c). Interestingly, the mutant receptor showed an increase in IC50 values for ET-1 (5 nM), ET-2 (27 nM), and ET-3 (127 nM) but displayed a much larger increase in IC50 value for SRTX 6c (> 10 uM). The lysine mutant receptor still elicited full inositol phosphate (IP) turnover responses in the presence of saturating concentrations of endothelins (10 nM of ET-1, 100 nM of ET-2, or 1 uM of ET-3), indicating that the mutation (K181D) did not affect the coupling of mutant receptor to the appropriate G protein. These results demonstrate that lysine-181 on the receptor is important for binding ET peptides; however, it is required for binding the ETb selective agonist-SRTX 6c.
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455
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Wong R, Lopaschuk G, Teo K, Walker D, Catellier D, Zhu G, Burton D, Collins-Nakai R, Montague T. In vivo skeletal muscle metabolism during dynamic exercise and recovery: assessment by nuclear magnetic resonance spectroscopy. Can J Cardiol 1992; 8:819-24. [PMID: 1423003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The purpose of this study was to define temporally phosphorus metabolism and pH in the gastrocnemius muscles of 21 normal adult subjects during rest, dynamic exercise to exhaustion, and early and late recovery. METHODS In vivo nuclear magnetic resonance spectroscopy. RESULTS At rest, the ratio of phosphocreatine to the alpha peak of ATP averaged 2.26 +/- 0.25, the inorganic phosphate to ATP ratio averaged 0.31 +/- 0.08 and pH averaged 7.10 +/- 0.04. The phosphorus metabolites exhibited immediate and progressive changes with exercise, reaching their minimum (phosphocreatine, 0.95 +/- 0.41) or maximum (inorganic phosphate, 1.95 +/- 0.75) values at exhaustion, after an average exercise of 11 +/- 4 mins. In contrast, pH changed slowly during early exercise, but fell abruptly thereafter and averaged 6.76 +/- 0.17 at exhaustion. Phosphocreatine and inorganic phosphate began to return rapidly towards preexercise values immediately on cessation of exercise. However, pH declined further in the period immediately following cessation of exercise, reaching a nadir of 6.56 +/- 0.24 an average of 2 mins into recovery. Exercise duration did not correlate highly with any metabolic variable. CONCLUSIONS The data support the concept that the metabolic physiology underlying physical exhaustion of dynamic exercising muscle is multifactorial. The post exercise drop in pH also suggests that normal subjects have a greater contribution to high energy phosphate production from glycolysis, as opposed to oxidative metabolism, in early recovery.
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456
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Zhu G, Ishizaki M, Haseba T, Wu RL, Sun TT, Kao WW. Expression of K12 keratin in alkali-burned rabbit corneas. Curr Eye Res 1992; 11:875-87. [PMID: 1385039 DOI: 10.3109/02713689209033485] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The healing of alkali-injured corneas is characterized by the persistence of polymorphonuclear leukocytes (PMN) in tissues and recurrent corneal epithelial defects. It has been suggested that the proteolytic enzymes secreted by PMN may account in part for the recurrent epithelial defects in the alkali-burned corneas. Cytoplasmic keratins, which form intracellular intermediate filaments, participate in the formation of hemidesmosomes and play a key role in the focal adhesion of epithelial cells to the basement membranes. The K3/K12 keratin pair is a major constituent of differentiated and stratified corneal epithelium. We have recently cloned the cDNA encoding the rabbit K12 keratin. In the present study we examined the expression of K12 keratin during the healing of alkali-burned rabbit corneas by slot-blot and in situ hybridization. Our results indicate that in normal cornea K12 keratin is equally expressed in all cell layers of stratified corneal epithelium and suprabasal layers of limbal epithelium, but not in bulbar conjunctival and other epithelia, i.e., lens, iris, and retinal pigment epithelium. The basal cells of the detached regenerating epithelium of the injured cornea express a very low level of K12 keratin. These observations are consistent with the notion that defective expression of K3/K12 keratins may play a role in the abnormal attachment of the regenerating epithelium to the basement membrane.
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457
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Ikura M, Clore GM, Gronenborn AM, Zhu G, Klee CB, Bax A. Solution structure of a calmodulin-target peptide complex by multidimensional NMR. Science 1992; 256:632-8. [PMID: 1585175 DOI: 10.1126/science.1585175] [Citation(s) in RCA: 941] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The three-dimensional solution structure of the complex between calcium-bound calmodulin (Ca(2+)-CaM) and a 26-residue synthetic peptide comprising the CaM binding domain (residues 577 to 602) of skeletal muscle myosin light chain kinase, has been determined using multidimensional heteronuclear filtered and separated nuclear magnetic resonance spectroscopy. The two domains of CaM (residues 6 to 73 and 83 to 146) remain essentially unchanged upon complexation. The long central helix (residues 65 to 93), however, which connects the two domains in the crystal structure of Ca(2+)-CaM, is disrupted into two helices connected by a long flexible loop (residues 74 to 82), thereby enabling the two domains to clamp residues 3 to 21 of the bound peptide, which adopt a helical conformation. The overall structure of the complex is globular, approximating an ellipsoid of dimensions 47 by 32 by 30 angstroms. The helical peptide is located in a hydrophobic channel that passes through the center of the ellipsoid at an angle of approximately 45 degrees with its long axis. The complex is mainly stabilized by hydrophobic interactions which, from the CaM side, involve an unusually large number of methionines. Key residues of the peptide are Trp4 and Phe17, which serve to anchor the amino- and carboxyl-terminal halves of the peptide to the carboxyl- and amino-terminal domains of CaM, respectively. Sequence comparisons indicate that a number of peptides that bind CaM with high affinity share this common feature containing either aromatic residues or long-chain hydrophobic ones separated by a stretch of 12 residues, suggesting that they interact with CaM in a similar manner.
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458
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Zhu G. [Effects of substance P in rat spinal cord on the humoral immune response to SRBC]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1992; 14:126-30. [PMID: 1377610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The effects of substance P (SP) in rat spinal cord on the humoral immune response to sheep red blood cells (SRBC) were investigated by the hemolytic plaque-forming cell (PFC) technique. Radioimmunoassay was used for assessing SP content. Catecholamines contents were measured by high performance liquid chromatography (HPLC) with electrochemical-detection. The results suggest that SP in the spinal dorsal horn, but not in the lateral horn, could inhibit the thymus-dependent humoral immune response to SRBC, and this inhibitory effect might be related to the influence of dorsal horn SP on thymic activity. Increased SP content in the spinal dorsal horn at the peak of a humoral immune response might suppress the immune response and play a negative feedback role, preventing excessive immune response.
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459
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Crawford G, Fulton R, Jensen T, Johnson DR, Kagan H, Kass R, Malchow R, Morrow F, Whitmore J, Wilson P, Bortoletto D, Brown D, Dominick J, McIlwain RL, Miller DH, Modesitt M, Ng CR, Schaffner SF, Shibata EI, Shipsey IP, Battle M, Kroha H, Sparks K, Thorndike EH, Wang C, Alam MS, Kim IJ, Li WC, Lou XC, Nemati B, Romero V, Sun CR, Wang P, Zoeller MM, Goldberg M, Haupt T, Horwitz N, Jain V, Kennett R, Mestayer MD, Moneti GC, Rozen Y, Rubin P, Skwarnicki T, Stone S, Thusalidas M, Yao W, Zhu G, Barnes AV, Bartelt J, Csorna SE, Letson T, Alexander J, Artuso M, Bebek C, Berkelman K, Besson D, Browder T, Cassel DG, Cheu E, Coffman DM, Drell PS, Ehrlich R, Galik RS. Measurement of baryon production in B-meson decay. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1992; 45:752-770. [PMID: 10014433 DOI: 10.1103/physrevd.45.752] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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460
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Zhu G, Jensen RG, Hallick RB, Wildner GF. Simple Determination of the CO(2)/O(2) Specificity of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase by the Specific Radioactivity of [C]Glycerate 3-Phosphate. PLANT PHYSIOLOGY 1992; 98:764-8. [PMID: 16668709 PMCID: PMC1080258 DOI: 10.1104/pp.98.2.764] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
A new method is presented for measurement of the CO(2)/O(2) specificity factor of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). The [(14)C]3-phosphoglycerate (PGA) from the Rubisco carboxylase reaction and its dilution by the Rubisco oxygenase reaction was monitored by directly measuring the specific radioactivity of PGA. (14)CO(2) fixation with Rubisco occurred under two reaction conditions: carboxylase with oxygenase with 40 micromolar CO(2) in O(2)-saturated water and carboxylase only with 160 micromolar CO(2) under N(2). Detection of the specific radioactivity used the amount of PGA as obtained from the peak area, which was determined by pulsed amperometry following separation by high-performance anion exchange chromatography and the radioactive counts of the [(14)C]PGA in the same peak. The specificity factor of Rubisco from spinach (Spinacia oleracea L.) (93 +/- 4), from the green alga Chlamydomonas reinhardtii (66 +/- 1), and from the photosynthetic bacterium Rhodospirillum rubrum (13) were comparable with the published values measured by different methods.
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461
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Bortoletto D, Brown DN, Dominick J, McIlwain RL, Miller DH, Modesitt M, Shibata EI, Schaffner S, Shipsey IP, Battle M, Kroha H, Sparks K, Thorndike EH, Wang C, Goldberg M, Haupt T, Horwitz N, Jain V, Moneti GC, Rozen Y, Rubin P, Skwarnicki T, Sharma V, Stone S, Thusalidas M, Yao W, Zhu G, Barnes AV, Bartelt J, Csorna SE, Letson T, Mestayer MD, Alexander J, Artuso M, Bebek C, Berkelman K, Besson D, Browder TE, Cassel DG, Cheu E, Coffman DM, Drell PS, Ehrlich R, Galik RS, Garcia-Sciveres M, Geiser B, Gittelman B, Gray SW, Halling AM, Hartill DL, Heltsley BK, Honscheid K, Kandaswamy J, Katayama N, Kreinick DL, Lewis JD, Ludwig GS, Masui J, Mevissen J, Mistry NB, Nandi S, Ng CR, Nordberg E, O'Grady C. Inclusive and exclusive decays of B mesons to final states including charm and charmonium mesons. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1992; 45:21-35. [PMID: 10014188 DOI: 10.1103/physrevd.45.21] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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462
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Ammar R, Baringer P, Coppage D, Davis R, Haas P, Kelly M, Kwak N, Lam H, Ro S, Kubota Y, Nelson JK, Perticone D, Poling R, Schrenk S, Crawford G, Fulton R, Jensen T, Johnson D, Kagan H, Kass R, Malchow R, Morrow F, Whitmore J, Wilson P, Bortoletto D, Brown DN, Dominick J, McIlwain RL, Miller DH, Modesitt M, Ng CR, Schaffner SF, Shibata EI, Shipsey IP, Battle M, Kroha H, Sparks K, Thorndike EH, Wang C, Alam MS, Kim IJ, Li WC, Nemati B, Romero V, Sun CR, Wang P, Zoeller MM, Goldberg M, Haupt T, Horwitz N, Jain V, Kennett R, Mestayer MD, Moneti GC, Rozen Y, Rubin P, Skwarnicki T, Stone S, Thusalidas M, Yao W, Zhu G, Barnes AV, Bartelt J, Csorna SE. Unusual decay modes of D0 and D+ mesons. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1991; 44:3383-3393. [PMID: 10013801 DOI: 10.1103/physrevd.44.3383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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463
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Zhu G, Jensen RG. Fallover of Ribulose 1,5-Bisphosphate Carboxylase/Oxygenase Activity : Decarbamylation of Catalytic Sites Depends on pH. PLANT PHYSIOLOGY 1991; 97:1354-8. [PMID: 16668556 PMCID: PMC1081171 DOI: 10.1104/pp.97.4.1354] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Loss of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity during CO(2) fixation, called fallover, occurred with or without loss of activator CO(2) from catalytic sites depending on pH. At pH 7.5, but not at pH 8.5, the fraction of Rubisco sites that were carbamylated decreased during fallover. Inhibitors which formed during fallover were identified following NaBH(4) reduction and separation of the products by high performance anion-exchange chromatography and pulsed amperometric detection. They were xylulose 1,5-bisphosphate (XuBP) and 3-ketoarabinitol 1,5-bisphosphate. During fallover at pH 8.5, 3-ketoarabinitol-P(2) was the only inhibitor binding to Rubisco and this binding was at carbamylated sites, although both inhibitors were made. At pH 7.5, both inhibitors were bound to catalytic sites of Rubisco with XuBP bound tightly to decarbamylated sites, whereas 3-ketoarabinitol-P(2) bound to carbamylated sites. The pH during fallover also influenced the ratio of 3-ketoarabinitol-P(2) to XuBP formed. When fallover occurred at pH 7.5, both the formation of XuBP and its binding affinity to decarbamylated Rubisco sites were increased compared with those at pH 8.5. 3-Ketoribitol-P(2) was not found at either pH.
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464
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Crawford G, Fulton R, Gan KK, Jensen T, Johnson DR, Kagan H, Kass R, Malchow R, Morrow F, Whitmore J, Wilson P, Bortoletto D, Brown D, Dominick J, McIlwain RL, Miller DH, Modesitt M, Ng CR, Schaffner SF, Shibata EI, Shipsey IP, Battle M, Kim P, Kroha H, Sparks K, Thorndike EH, Wang C, Alam MS, Kim IJ, Nemati B, Romero V, Sun CR, Wang P, Zoeller MM, Goldberg M, Haupt T, Horwitz N, Jain V, Kennett R, Mestayer MD, Moneti GC, Rozen Y, Rubin P, Skwarnicki T, Stone S, Thusalidas M, Yao W, Zhu G, Barnes AV, Bartelt J, Csorna SE, Letson T, Alexander J, Artuso M, Bebek C, Berkelman K, Besson D, Browder T, Cassel DG, Cheu E, Coffman DM, Drell PS, Ehrlich R, Galik RS. Measurement of the ratio B(D0-->K*-e+ nu e)/B(D0-->K-e+ nu e). PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1991; 44:3394-3401. [PMID: 10013802 DOI: 10.1103/physrevd.44.3394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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465
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Zhu G, Jensen RG. Xylulose 1,5-Bisphosphate Synthesized by Ribulose 1,5-Bisphosphate Carboxylase/Oxygenase during Catalysis Binds to Decarbamylated Enzyme. PLANT PHYSIOLOGY 1991; 97:1348-53. [PMID: 16668555 PMCID: PMC1081170 DOI: 10.1104/pp.97.4.1348] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Xylulose 1,5-bisphosphate (XuBP) is synthesized from ribulose 1,5-bisphosphate (RuBP) at carbamylated catalytic sites on ribulose 1,5-bisphosphate carboxylase (Rubisco) with significant amounts of XuBP being formed at pH less than 8.0. XuBP has been separated by high performance liquid chromatography and identified by pulsed amperometry from compounds bound to Rubisco during catalysis with the purified enzyme and from celery (Apium graveolens var Utah) leaf extracts. XuBP does not bind tightly to carbamylated sites, but does bind tightly to decarbamylated sites. Upon incubation of fully activated Rubisco with 5 micromolar XuBP, loss of activator CO(2) occurred before XuBP bound to the enzyme catalytic sites, even in the presence of excess CO(2) and Mg(2+). Binding of XuBP to decarbamylated Rubisco sites was highly pH dependent. At pH 7.0 and 7.5 with 10 millimolar MgCl(2) and 10 millimolar KHCO(3), the apparent dissociation constant for XuBP, K(d), was 0.03 micromolar, whereas at pH 8.0 and 8.5, the apparent K(d) was 0.35 and 2.0 micromolar, respectively. This increase in K(d) with pH was a result of a decrease in the association rate constant and an increase in the dissociation rate constant of XuBP bound to decarbamylated sites on Rubisco. The K(d) of 2-carboxyarabinitol 1-phosphate binding to carbamylated sites was only slightly pH dependent.
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466
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Zhu G. A historical demography of Chinese migration. SOCIAL SCIENCES IN CHINA 1991; 12:57-84. [PMID: 12343579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Trends in international migration from China are analyzed from historical times to the present. "The study will involve discussions about the nature of migration and the different forms it took in five different stages, in the light of 1) changes in motivation, 2) type of migration, and 3) the distribution of the out-going population."
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467
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Kubota Y, Nelson JK, Perticone D, Poling R, Schrenk S, Crawford G, Fulton R, Jensen T, Johnson DR, Kagan H, Kass R, Malchow R, Morrow F, Whitmore J, Wilson P, Bortoletto D, Brown D, Dominick J, McIlwain RL, Miller DH, Modesitt M, Ng CR, Schaffner SF, Shibata EI, Shipsey IP, Battle M, Kroha H, Sparks K, Thorndike EH, Wang C, Alam MS, Kim IJ, Li WC, Nemati B, Romero V, Sun CR, Wang P, Zoeller MM, Goldberg M, Haupt T, Horwitz N, Jain V, Mestayer MD, Moneti GC, Rozen Y, Rubin P, Skwarnicki T, Stone S, Thusalidas M, Yao W, Zhu G, Barnes AV, Bartelt J, Csorna SE, Letson T, Avery P, Alexander J, Artuso M, Bebek C, Berkelman K, Besson D, Browder T, Cassel DG, Cheu E. Study of continuum D*+ spin alignment. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1991; 44:593-600. [PMID: 10013915 DOI: 10.1103/physrevd.44.593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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468
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Avery P, Besson D, Garren L, Yelton J, Kinoshita K, Pipkin FM, Procario M, Wilson R, Wolinski J, Xiao D, Zhu Y, Ammar R, Baringer P, Coppage D, Haas P, Kwak N, Lam H, Ro S, Kubota Y, Nelson JK, Perticone D, Poling R, Fulton R, Jensen T, Johnson DR, Kagan H, Kass R, Morrow F, Whitmore J, Wilson P, Bortoletto D, Dominick J, McIlwain RL, Miller DH, Ng CR, Schaffner SF, Shibata EI, Shipsey IP, Yao W, Sparks K, Thorndike EH, Wang C, Alam MS, Kim IJ, Li WC, Lou XC, Romero V, Sun CR, Wang P, Zoeller MM, Goldberg M, Haupt T, Horwitz N, Jain V, Mestayer MD, Moneti GC, Rozen Y, Rubin P, Sharma V, Skwarnicki T, Thulasidas M, Zhu G, Csorna SE, Letson T. Inclusive production of the charmed baryon Lambda c+ from e+e- annihilations at sqrt s =10.55 GeV. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1991; 43:3599-3610. [PMID: 10013319 DOI: 10.1103/physrevd.43.3599] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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469
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Zhu G. [Percutaneous transluminal coronary angioplasty. A report of 100 cases]. ZHONGHUA XIN XUE GUAN BING ZA ZHI 1991; 19:145-7, 196-7. [PMID: 1914853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Percutaneous transluminal coronary angioplasty (PTCA) was performed in 100 coronary heart patients with 122 vessels and 138 lesions dilated. Among these 100 cases, there were 39 complex PTCA performed. The primary success rate was 93% (93/100), was 94.3% (115/122) according to vessel dilated and was 92.1% (127/138) according to lesion dilated. In 4 cases whose lesions were located at the bifurcation of the vessel, kissing balloon technique via a single guiding catheter was applied with success. In 5 cases of total occlusion PTCA was performed with success in 4. PTCA with stent in 1. PTCA was performed in 1 cases of high risk whose LVEF was only 30% and coronary hemoperfusion pump was used during the procedure. Emergency PTCA was performed in 3 AMI patients during the acute phase and elective PTCA in 8 AMI cases after successful thrombolytic therapy. There were complications in 9 cases (9%). Among these 9 cases, 2 developed O-wave MI which recovered after medicinal therapy. One AMI complicated with heart failure was treated by emergency PTCA with success, but the patient died 10 days after PTCA due to pump failure and pulmonary infection. There were no deaths due to PTCA, nor was emergency coronary artery bypass graft (CABG) performed. These cases were followed for 1-30 months on an average of 13 months. Clinical success rate was 91.3%. The clinical success rate was 93.1% by 201Tl perfusion study. Restenosis in 7 cases was confirmed by coronary angiography. For these restenotic cases, PTCA was repeated with success in 4, CABG performed in 1, coronary atherectomy in 1, and medicinal therapy employed in 1 patient.(ABSTRACT TRUNCATED AT 250 WORDS)
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470
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Qu Y, Zhu G. [Proper concentration of the solution of softsoap or sodium bicarbonate for washing syringes]. ZHONGHUA HU LI ZA ZHI = CHINESE JOURNAL OF NURSING 1991; 26:159-61. [PMID: 1647890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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471
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Sakai J, Hung J, Zhu G, Katakami C, Boyce S, Kao WW. Collagen metabolism during healing of lacerated rabbit corneas. Exp Eye Res 1991; 52:237-44. [PMID: 1849830 DOI: 10.1016/0014-4835(91)90086-t] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We previously demonstrated that there are two waves of increased collagen synthesis following corneal laceration in rabbits. In the present study, we have examined whether increases in collagen synthesis and degradation result from increased amounts of mRNAs for collagen and collagenase, respectively. Rabbits were anesthetized by combined administration of ketamine (intramuscular) and pentobarbital (intravenous). A penetrating 8-mm incision was made at the center of each cornea. The lacerated corneas were allowed to heal for 0-49 days. The rabbits were then killed and the corneas excised. The total RNA was extracted from the tissue and subjected to slot-blot hybridization using 32P-labeled alpha 1(I) cDNA. The results indicate that there is a two-phase increase in the amount of alpha 1(I) mRNA in injured corneas and that the collagenase mRNA is elevated at most times throughout the healing period. However, the increase is collagenase mRNA may not fully account for the accelerated collagen degradation during corneal wound-healing. Thus, we propose that cells in the wound area may be directly involved in collagen degradation by phagocytosis. To examine our hypothesis, we cultured injured rabbit corneas in the presence or absence of leupeptin, a proteinase inhibitor. The tissues were then examined by electron microscopy. In the presence of leupeptin, lysosomes within fibroblasts or fibroblast-like cells in the wound area of the lacerated corneas healed for 2 and 3 weeks, contain collagen fibrils. In the absence of leupeptin no identifiable collagen was seen in the lysosomes.(ABSTRACT TRUNCATED AT 250 WORDS)
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472
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Zhu G. [Issue of population quality under economic reform]. REN KOU XUE KAN (CHANGCHUN SHI, CHINA) 1991:23-7, 22. [PMID: 12317518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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473
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Fulton R, Jensen T, Johnson DR, Kagan H, Kass R, Morrow F, Whitmore J, Wilson P, Bortoletto D, Chen W, Dominick J, McIlwain RL, Miller DH, Ng CR, Schaffner SF, Shibata EI, Shipsey IP, Yao W, Battle M, Sparks K, Thorndike EH, Wang C, Alam MS, Kim IJ, Li WC, Romero V, Sun CR, Wang P, Zoeller MM, Goldberg M, Haupt T, Horwitz N, Jain V, Mestayer MD, Moneti GC, Rozen Y, Rubin P, Sharma V, Skwarnicki T, Thulasidas M, Zhu G, Csorna SE, Letson T, Alexander J, Artuso M, Bebek C, Berkelman K, Browder T, Cassel DG, Cheu E, Coffman DM, Crawford G, DeWire JW, Drell PS, Ehrlich R, Galik RS, Garcia-Sciveres M, Geiser B, Gittelman B, Gray SW, Halling AM, Hartill DL, Heltsley BK, Honscheid K. Exclusive and inclusive semileptonic decays of B mesons to D mesons. PHYSICAL REVIEW. D, PARTICLES AND FIELDS 1991; 43:651-663. [PMID: 10013429 DOI: 10.1103/physrevd.43.651] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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474
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Liu Q, Zhu G, Huang P. [Anti-inflammatory, analgesic and sedative effects of Leontice kiangnanensis P.L. Chiu]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1991; 16:50-3, 65. [PMID: 2069706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The ethanolic extract of Leontice kiangnanensis (EELK) can inhibit obviously the increased permeability of abdominal blood capillaries and the ear inflammation in mice as well as the swelling of hind paw and the proliferation of granuloma induced by cotton-pellets in rats, EELK can also raise the pain thresholds during hot-plate, formaldehyde and writhing tests in mice. Use of EELK together with pentobarbital may enhance sedative effect on mice.
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475
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Zhu G. [GC-MS analysis of essential oil of 10 species of Chinese Elsholtzia]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1990; 15:677-9, 703. [PMID: 2282158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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476
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Wong R, Davies N, Marshall D, Allen P, Zhu G, Lopaschuk G, Montague T. Metabolism of normal skeletal muscle during dynamic exercise to clinical fatigue: in vivo assessment by nuclear magnetic resonance spectroscopy. Can J Cardiol 1990; 6:391-5. [PMID: 2276074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
In vivo nuclear magnetic resonance (NMR) spectroscopy was used to define several intracellular high energy phosphate variables of the gastrocnemius muscle of normal subjects during rest, graded plantar flexion exercise to exhaustion, and recovery. There were nine males and eight females with an average age of 34 +/- 8 years. At rest, pH averaged 7.09 +/- 0.03 and the energy cost index (ECI)--the ratio of inorganic phosphate to phosphocreatine--averaged 0.13 +/- 0.03. At peak exercise, the ECI increased markedly to 2.71 +/- 2.0 (P less than 0.001) and pH fell precipitately to 6.76 +/- 0.17 (P less than 0.001), indicating the high intensity of the exercise. Exercise endurance averaged 12 +/- 5 mins; it was not highly correlated with sex, age (r = 0.35), rest pH (r = 0.26), rest ECI (r = 0.38), peak exercise pH (r = 0.23) or peak exercise ECI (r = 0.38), nor exercise changes in pH (r = 0.17) and ECI (r = 0.28). At 23 mins post exercise all variables were similar to rest. Rest pH was the only variable different between males (7.10 +/- 0.03) and females (7.07 +/- 0.03) (P less than 0.05). Thus, dynamic exercise of large skeletal muscles in normal subjects was characterized by marked temporal changes in high energy phosphate profiles and very low pH at exhaustion. No single metabolic variable correlated highly with exercise endurance, suggesting that the intracellular pathophysiology of exhaustive muscle exercise and clinical fatigue may be multifactorial.
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477
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Wang S, Zhu G. [Effects of Codonopsis pilosulae on the synthesis of thromboxane A2 and prostacyclin]. ZHONG XI YI JIE HE ZA ZHI = CHINESE JOURNAL OF MODERN DEVELOPMENTS IN TRADITIONAL MEDICINE 1990; 10:391-4, 387. [PMID: 2208415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
24 angina pectoris patients were treated with Codonopsis pilosulae (CP) oral solution 20 ml (containing crude CP 20 g) thrice daily for 7 days, other 10 cases were treated by aspirin 0.5 g per day for a week as the control group. After treatment, in the CP group, the plasma level of TXB2 was obviously reduced from 156.76 +/- 11.87 pg/ml to 125.01 +/- 8.85 pg/ml (means +/- S means), the inhibitory rates was 15. 67% (P less than 0.05), and of 6-keto-PGF1 alpha (6-K) was not markedly changed (P greater than 0.05). In the aspirin group, TXB2 was also reduced significantly (P less than 0.05); 6-K was reduced more than that of CP group, the inhibitory rate was 24.33 +/- 9.40% (P less than 0.05). To reveal the mechanism of CP action on the synthesis of TXA2 and PGI2, the porcine lung microsome was used as the donor of cyclooxygenase, thromboxane synthase and prostacyclin synthase, the effects of CP on the formation of TXB2 and 6-K from arachidonic acid (AA) or endoperoxides were measured by RIA respectively. The results showed that both the levels of the formation of TXB2 from AA or endoperoxides were markedly reduced by CP in a dose-dependent (at doses of 3-300 mg/ml). The synthesis of TXB2 was distinctly inhibited alone with a dose of 100 mg/ml CP, which suggested that CP might be an inhibitor of TXB2 synthase at that dose; while at a dose of 300 mg/ml CP, the synthesis of TXB2 and 6-K were inhibited simultaneously (P less than 0.001). It showed that a larger dosage of CP, which could inhibited the synthesis of both TXA2 and PGI2, its mechanism of action needs further study.
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478
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Zhu G, Jensen RG. Status of the substrate binding sites of ribulose bisphosphate carboxylase as determined with 2-C-carboxyarabinitol 1,5-bisphosphate. PLANT PHYSIOLOGY 1990; 93:244-9. [PMID: 16667442 PMCID: PMC1062495 DOI: 10.1104/pp.93.1.244] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The properties of the tight and specific binding of 2-C-carboxy-d-arabinitol 1,5-bisphosphate (CABP), which occurs only to reaction sites of ribulose 1,5-bisphosphate carboxylase (Rubisco) that are activated by CO(2) and Mg(2+), were studied. With fully active purified spinach (Spinacia oleracea) Rubisco the rate of tight binding of [(14)C]CABP fit a multiple exponential rate equation with half of the sites binding with a rate constant of 40 per minute and the second half of the sites binding at 3.2 per minute. This suggests that after CABP binds to one site of a dimer of Rubisco large subunits, binding to the second site is considerably slower, indicating negative cooperativity as previously reported (S Johal, BE Partridge, R Chollet [1985] J Biol Chem 260: 9894-9904). The rate of CABP binding to partially activated Rubisco was complete within 2 to 5 minutes, with slower binding to inactive sites as they formed the carbamate and bound Mg(2+). Addition of [(14)C]CABP and EDTA stopped binding of Mg(2+) and allowed tight binding of the radiolabel only to sites which were CO(2)/Mg(2+)-activated at that moment. This approach estimated the amount of CO(2)/Mg(2+)-activated sites in the presence of inactive sites and carbamylated sites lacking Mg(2+). The rate of CO(2) fixation was proportional to the CO(2)/Mg(2+)-activated sites. During light-dependent CO(2) fixation with isolated spinach chloroplasts, the amount of carbamylation was proportional to Rubisco activity either initially upon lysis of the plastids or following total activation with Mg(2+) and CO(2). Lysis of chloroplasts in media with [(14)C]CABP plus EDTA estimated those carbamylated sites having Mg(2+). The loss of Rubisco activation during illumination was partially due to the lack of Mg(2+) to stabilize the carbamylated sites.
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479
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Zhu G. A probe into reasons for international migration in Fujian Province. CHINESE JOURNAL OF POPULATION SCIENCE 1990; 2:229-46. [PMID: 12284987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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480
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Melber K, Zhu G, Diamond L. SV40-transfected human melanocyte sensitivity to growth inhibition by the phorbol ester 12-O-tetradecanoylphorbol-13-acetate. Cancer Res 1989; 49:3650-5. [PMID: 2543501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Normal human melanocytes, which require the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) for growth in culture, were transfected with a SV40 T-antigen-containing plasmid by using the technique of electroporation, and were scored for colonies of morphologically altered cells. The frequency of transformed colonies was higher when selection was done in the absence rather than the presence of TPA in the medium. Three cell lines derived from transformed colonies were characterized. All show an enhanced growth rate compared to parental cells, anchorage independence, loss of dependence on medium supplements for growth, chromosomal abnormalities, an extended life span, and growth inhibition by TPA. They express nerve growth factor receptor and Mr 97,000 protein, melanotransferrin, two antigens usually associated with melanocytic cells, but the transformed cells are not pigmented. The three cell lines underwent crisis at about passage 10 posttransfection; one cell line recovered and appears to have unlimited growth potential. None of the cell lines is tumorigenic. They should be interesting models for studying multistage carcinogenesis in human cells and transcriptional activation by TPA.
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481
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Falian H, Dexin Z, Weizhong J, Zhu G. Bonding of resinous filling materials to acid-etched teeth: a scanning electron microscopic observation. QUINTESSENCE INTERNATIONAL (BERLIN, GERMANY : 1985) 1989; 20:27-30. [PMID: 2669016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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482
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Tong ZH, Gu WZ, Zhu G, Zhao YW. The anti-aging effect of pearl oyster shell powder (POSP). J TRADIT CHIN MED 1988; 8:247-50. [PMID: 3150022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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483
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Hsu KG, Zhu G, Yang LS, Tso JK. [Effect of endogenous cAMP changes on the oocyte maturation of Bufo bufo gargarizans]. SHI YAN SHENG WU XUE BAO 1987; 20:451-8. [PMID: 2834900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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484
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Tong ZH, Gu WZ, Zhu G. [Effect on plasma glucose and serum insulin after xylitol loading in 30 normal adults]. ZHONGHUA NEI KE ZA ZHI 1987; 26:420-2, 446. [PMID: 3322708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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485
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Zhu G. [A historical survey of international migration of China population]. REN KOU YAN JIU = RENKOU YANJIU 1987:24-9. [PMID: 12159296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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486
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Ye DN, Shen RQ, Yan RH, Zhu G, Li SF, Dai BM. [Screening and identification of hybridomas producing monoclonal antibodies against Pseudomonas aeruginosa strain PA II 10117 and strain PA IV 10119]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1987; 18:119-21. [PMID: 3114120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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487
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Tong ZH, Zhu G, Yan LX, Zhu J, Feng YG, Xu G. Association of HLA with Graves' disease in Chinese. Chin Med J (Engl) 1987; 100:296-8. [PMID: 3115694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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488
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Liu KW, Liu FY, Li YJ, Zhu G, Liu MZ. [The termination of early pregnancy by inducing menstrual flow with crystalline trichosanthinin complex in 86 cases]. SHENG ZHI YU BI YUN = REPRODUCTION AND CONTRACEPTION 1985; 5:55-6. [PMID: 12340683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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