776
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Marshall TK, Guo H, Price DH. Drosophila RNA polymerase II elongation factor DmS-II has homology to mouse S-II and sequence similarity to yeast PPR2. Nucleic Acids Res 1990; 18:6293-8. [PMID: 2243775 PMCID: PMC332494 DOI: 10.1093/nar/18.21.6293] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
DmSII is a Drosophila RNA polymerase II elongation factor which suppresses pausing by RNA polymerase II at specific sites on double stranded templates. Using antibodies produced against the purified protein, a Drosophila cDNA expression library was screened and a cDNA was isolated which encoded a portion of DmSII. When this cDNA was used to probe Kc cell mRNA the predominant species was found to be 1.4 kb in length. The original cDNA was used to screen a Drosophila Kc cell cDNA library resulting in the isolation of a 1.4 kb cDNA which was then sequenced. The deduced protein sequence for DmSII exhibited high similarity to mouse SII protein sequence. In addition, significant sequence similarity was found with the protein encoded by the yeast gene PPR2, which is involved in regulation of URA4 gene expression. The comparison of amino acid sequences suggests that DmSII is comprised of two domains homologous to mouse SII separated by a flexible, serine rich region of low homology. The shorter yeast protein has sequence similarity only to the carboxy terminal domain.
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777
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Lin T, Wang DL, Calkins JH, Guo H, Chi R, Housley PR. Regulation of insulin-like growth factor-I messenger ribonucleic acid expression in Leydig cells. Mol Cell Endocrinol 1990; 73:147-52. [PMID: 2269394 DOI: 10.1016/0303-7207(90)90127-t] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In the present study, we evaluated insulin-like growth factor-I (IGF-I) messenger RNA expression in the rat testis. Crude interstitial cells were separated into three distinct bands on 15-60% Percoll density gradients. IGF-I mRNA was mainly localized in the Leydig cell-enriched fraction (band 3), while band 1 and band 2 cells did not contain significant amounts of IGF-I mRNA. Leydig cell IGF-I mRNA consisted of multiple species varying from 0.8 to 7.5 kb and was present in rat Leydig cells all ages examined, from 25 to 55 days old. To further document that IGF-I mRNAs are present in Leydig cells, the method of Klinefelter et al. (Biol. Reprod. (1987) 36, 769-783) was used to isolate highly purified (greater than 98% pure) Leydig cells. Most of the IGF-I mRNA was localized in these Leydig cells, while there was no detectable IGF-I mRNA in the whole testis or other interstitial cells. Furthermore, IGF-I mRNA in Leydig cells was increased more than 2-fold by growth hormone (GH) administration in vivo. This suggests that IGF-I mRNA in Leydig cells is also GH dependent. Interstitial IGF-I produced in Leydig cells may have both autocrine and paracrine effects in the testis.
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778
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Abstract
Interstitial tissue of the testis consists of Leydig cells, macrophages, lymphocytes, plasma cells, mast cells and fibroblasts. Previously we have reported that interleukin-1 (IL-1) inhibits Leydig cell androgen production. In the present study, the effect of IL-2 was investigated. Leydig cells (10(5) cells/ml) from adult Sprague-Dawley rats were cultured with or without IL-2 for 24 h. After medium changes, human CG (hCG), 8-bromo-cAMP, or forskolin was added with or without IL-2. Cultures were continued for an additional 24 h, and testosterone and cAMP levels were measured. IL-2 up to 100 U/ml had no effect on basal testosterone production. hCG-stimulated testosterone formation was inhibited in a dose-dependent manner by the addition of IL-2. IL-2 in a concentration of 100 U/ml decreased hCG-induced testosterone formation from 49.6 +/- 3.6 ng/ml (mean +/- SE) to 8.5 +/- 4.2 ng/ml. The hCG dose-response curve was shifted to the right by the addition of IL-2. Maximal testosterone production in response to hCG was reduced 40% in the presence of IL-2 (50 U/ml) without alteration of median effective dose (ED50). IL-2 also inhibited hCG-induced cAMP formation and 8-bromo cAMP- and forskolin-stimulated testosterone production. However, IL-2 did not alter the binding of [125I]hCG to purified Leydig cells. Furthermore, IL-2 significantly inhibited the conversion of 20-OH-cholesterol, 22-OH-cholesterol, pregnenolone, progesterone, 17 alpha-hydroxypregnenolone, and 17 alpha-hydroxyprogesterone to testosterone but did not alter the conversion of dehydroepiandrosterone and androstenedione to testosterone. Our results suggest that a T cell growth factor, IL-2, is a potent inhibitor of steroidogenesis. IL-2 may play a paracrine role in modulating Leydig cell function.
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779
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Kass SR, Guo H, Dahlke GD. The thiomethyl anion: Formation, reactivity, and thermodynamic properties. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 1990; 1:366-371. [PMID: 24248898 DOI: 10.1016/1044-0305(90)85016-f] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/1990] [Accepted: 04/10/1990] [Indexed: 06/02/2023]
Abstract
The thiomethyl anion (1) has been generated by fluorodesilylation of trimethylsilylmethanethiol in a variable-temperature flowing afterglow device. The proton affinity (1649 ± 12 kJ mol(-1)) and electron affinity (0.67 ± .13 eV) were determined and compared to a previously reported molecular orbital calculation. Isomerization via a 1,2-proton shift does not take place between -40° and 100°C despite a 156 kJ mol(-1) driving force. Ion-molecule reactions of 1 were examined with a number of reagents including N20, O2, CS2, COS, and CO2, Hydride ion transfer was observed in every case, along with other products, and thermodynamic information has been derived.
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780
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Guo H, Grossmann B, Grant M. Crossover scaling in the dynamics of driven systems. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1990; 41:7082-7085. [PMID: 9903136 DOI: 10.1103/physreva.41.7082] [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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781
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Grossmann B, Guo H, Grant M. Monte Carlo renormalization-group study of self-organized criticality. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1990; 41:4195-4198. [PMID: 9903613 DOI: 10.1103/physreva.41.4195] [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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782
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783
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Calkins JH, Guo H, Sigel MM, Lin T. Differential effects of recombinant interleukin-1 alpha and beta on Leydig cell function. Biochem Biophys Res Commun 1990; 167:548-53. [PMID: 2157407 DOI: 10.1016/0006-291x(90)92059-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Previously we have reported that human chorionic gonadotropin(hCG)-stimulated testosterone biosynthesis was markedly inhibited by purified natural human interleukin-1 (IL-1). In the present study we evaluated the effects of human and murine recombinant IL-1 (rIL-1) on Leydig cell steroidogenesis in primary culture. Human rIL-1 beta caused a dose-dependent inhibition of hCG-, 8-bromo cyclic AMP-, and forskolin-induced testosterone formation. In contrast, human rIL-1 alpha was considerably less potent. When the effects of the cytokines were corrected for their biological potencies, human rIL-1 beta and murine rIL-1 alpha were still more effective than human rIL-1 alpha in inhibiting testosterone production (at least 100-fold more potent). Thus, even though IL-1 alpha and IL-1 beta bind to the same receptors on T cells, Leydig cells exhibit differential sensitivity in response to rIL-1 alpha and rIL-1 beta which is partly species dependent.
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784
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Guo H, Hong DC. Random-walk simulation of the solvability theory for the Saffman-Taylor problem. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1990; 41:2995-2998. [PMID: 9903449 DOI: 10.1103/physreva.41.2995] [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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785
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Guo H, Grossmann B, Grant M. Kinetics of interface growth in driven systems. PHYSICAL REVIEW LETTERS 1990; 64:1262-1265. [PMID: 10041349 DOI: 10.1103/physrevlett.64.1262] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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786
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Calkins JH, Guo H, Sigel MM, Lin T. Tumor necrosis factor-alpha enhances inhibitory effects of interleukin-1 beta on Leydig cell steroidogenesis. Biochem Biophys Res Commun 1990; 166:1313-8. [PMID: 2154976 DOI: 10.1016/0006-291x(90)91009-h] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Human recombinant tumor necrosis factor-alpha (rTNF alpha) alone (up to 1000 units/ml) did not alter either basal or human chorionic gonadotropin (hCG)-induced testosterone formation in primary culture of rat Leydig cells. However, concomitant addition of rTNF alpha with human recombinant interleukin-1 beta (rIL-1 beta) enhanced the inhibitory effects of rIL-1 beta. The rIL-1 beta dose response curve was shifted to the left (IC50 changed from 1 ng/ml to 0.3 ng/ml). Even though rTNF alpha had no effect on testosterone formation, hCG-stimulated cyclic AMP formation was inhibited by rTNF alpha in a dose dependent manner. In the presence of both rTNF alpha and rIL-1 beta, hCG-induced cyclic AMP formation and binding of [125I]-hCG to Leydig cells were further inhibited. Testicular macrophages represent about 20% of the interstitial cells. TNF alpha and IL-1 may be produced locally by interstitial macrophages and have paracrine effects on Leydig cell function.
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787
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Sun T, Guo H, Grant M. Dynamics of driven interfaces with a conservation law. PHYSICAL REVIEW. A, GENERAL PHYSICS 1989; 40:6763-6766. [PMID: 9902085 DOI: 10.1103/physreva.40.6763] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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788
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Hernández-Machado A, Guo H, Mozos JL, Jasnow D. Interfacial growth in driven diffusive systems. PHYSICAL REVIEW. A, GENERAL PHYSICS 1989; 39:4783-4788. [PMID: 9901830 DOI: 10.1103/physreva.39.4783] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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789
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Zheng Q, Guo H, Gunton JD. Growth of breath figures and a possible relationship with ultradynamics. PHYSICAL REVIEW. A, GENERAL PHYSICS 1989; 39:3181-3184. [PMID: 9901614 DOI: 10.1103/physreva.39.3181] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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790
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Zheng Q, Guo H, Gunton JD. Finite-size scaling theory for domain growth in the time-dependent Ginzburg-Landau model: Layered system. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 39:4563-4567. [PMID: 9948807 DOI: 10.1103/physrevb.39.4563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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791
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Guo H, Jasnow D. Erratum: Hyperuniversality and the renormalization group for finite systems. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 39:753. [PMID: 9949139 DOI: 10.1103/physrevb.39.753] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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792
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Chen RG, Pan XS, Qian DL, Guo H. Twenty-one cases of phenylketonuria out of 358,767 newborns in Shanghai, China. J Inherit Metab Dis 1989; 12:485. [PMID: 2516180 DOI: 10.1007/bf01802047] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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793
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Guo H, Zheng Q, Gunton JD. Finite-size scaling theory for domain growth in the time-dependent Ginzburg-Landau model. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 38:11547-11549. [PMID: 9946036 DOI: 10.1103/physrevb.38.11547] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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794
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Braga J, Guo H, Murrell J, Dunne L. A comparative study of quantum mechanical and classical trajectory calculations for anA+BCcollinear non-adiabatic collision. Mol Phys 1988. [DOI: 10.1080/00268978800101491] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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795
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Dunne L, Guo H, Murrell J. The role of the[Btilde]-[Xtilde]conical intersection in the photodissociation of water. Mol Phys 1987. [DOI: 10.1080/00268978700102201] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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796
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Guo H, Jasnow D. Hyperuniversality and the renormalization group for finite systems. PHYSICAL REVIEW. B, CONDENSED MATTER 1987; 35:1846-1850. [PMID: 9941607 DOI: 10.1103/physrevb.35.1846] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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797
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Farrar JM, Bowers MT, Leone SR, Gislason EA, Murrell JN, Braga JP, Dunne LJ, Guo H, Clary DC, Varandas AJC, Smith IWM, Rubahn HG, Sathyamurthy N, Toennies JP. General discussion. ACTA ACUST UNITED AC 1987. [DOI: 10.1039/dc9878400351] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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798
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Guo H, Jasnow D. Evidence for scaling in an interfacial growth instability: The solid case. PHYSICAL REVIEW. A, GENERAL PHYSICS 1986; 34:5027-5034. [PMID: 9897888 DOI: 10.1103/physreva.34.5027] [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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