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Carman DS, Joo K, Mestayer MD, Raue BA, Adams G, Ambrozewicz P, Anciant E, Anghinolfi M, Armstrong DS, Asavapibhop B, Audit G, Auger T, Avakian H, Bagdasaryan H, Ball JP, Barrow SP, Battaglieri M, Beard K, Bektasoglu M, Bellis M, Bennhold C, Bianchi N, Biselli AS, Boiarinov S, Bonner BE, Bouchigny S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Burkert VD, Butuceanu C, Calarco JR, Carnahan B, Cazes A, Cetina C, Ciciani L, Clark R, Cole PL, Coleman A, Cords D, Corvisiero P, Crabb D, Crannell H, Cummings JP, DeSanctis E, Degtyarenko PV, Denizli H, Dennis L, DeVita R, Dharmawardane KV, Dhuga KS, Djalali C, Dodge GE, Doughty D, Dragovitsch P, Dugger M, Dytman S, Dzyubak OP, Eckhause M, Egiyan H, Egiyan KS, Elouadrhiri L, Empl A, Eugenio P, Fatemi R, Fedotov G, Feuerbach RJ, Ficenec J, Forest TA, Funsten H, Gaff SJ, Gai M, Garçon M, Gavalian G, Gilad S, Gilfoyle GP, Giovanetti KL, Girard P, Golovach E, Gordon CIO, Griffioen K, Grimes S, Guidal M, Guillo M, Guo L, Gyurjyan V, Hadjidakis C, Hakobyan RS, Hardie J, Heddle D, Heimberg P, Hersman FW, Hicks K, Hicks RS, Holtrop M, Hu J, Hyde-Wright CE, Ishkhanov B, Ito MM, Jenkins D, Kelley JH, Kellie JD, Khandaker M, Kim KY, Kim K, Kim W, Klein A, Klein FJ, Klimenko AV, Klusman M, Kossov M, Kramer LH, Kuang Y, Kuhn SE, Kuhn J, Lachniet J, Laget JM, Lawrence D, Li J, Livingston K, Longhi A, Lukashin K, Manak JJ, Marchand C, Mart T, McAleer S, McCarthy J, McNabb JWC, Mecking BA, Mehrabyan S, Melone JJ, Meyer CA, Mikhailov K, Minehart R, Mirazita M, Miskimen R, Mokeev V, Morand L, Morrow SA, Mozer MU, Muccifora V, Mueller J, Murphy LY, Mutchler GS, Napolitano J, Nasseripour R, Nelson SO, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niyazov RA, Nozar M, O'Rielly GV, Opper AK, Osipenko M, Park K, Paschke K, Pasyuk E, Peterson G, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Qin LM, Riccardi G, Ricco G, Ripani M, Ritchie BG, Ronchetti F, Rossi P, Rowntree D, Rubin P, Sabatié F, Sabourov K, Salgado C, Santoro J, Sapunenko V, Schumacher RA, Serov VS, Sharabian YG, Shaw J, Simionatto S, Skabelin AV, Smith ES, Smith LC, Sober DI, Spraker M, Stavinsky A, Stepanyan S, Stoler P, Taiuti M, Taylor S, Tedeschi DJ, Thoma U, Thompson R, Todor L, Tur C, Ungaro M, Vineyard MF, Vlassov AV, Wang K, Weinstein LB, Weller H, Weygand DP, Whisnant CS, Wolin E, Wood MH, Yegneswaran A, Yun J, Zhang B, Zhao J, Zhou Z. First measurement of transferred polarization in the exclusive ep-->e'K+Lambda--> reaction. PHYSICAL REVIEW LETTERS 2003; 90:131804. [PMID: 12689277 DOI: 10.1103/physrevlett.90.131804] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2002] [Indexed: 05/24/2023]
Abstract
The first measurements of the transferred polarization for the exclusive e-->p-->e(')K+Lambda--> reaction have been performed at Jefferson Laboratory using the CLAS spectrometer. A 2.567 GeV beam was used to measure the hyperon polarization over Q2 from 0.3 to 1.5 (GeV/c)(2), W from 1.6 to 2.15 GeV, and over the full K+ center-of-mass angular range. Comparison with predictions of hadrodynamic models indicates strong sensitivity to the underlying resonance contributions. A nonrelativistic quark-model interpretation of our data suggests that the ssmacr; quark pair is produced with spins predominantly antialigned. Implications for the validity of the most widely used quark-pair creation operator are discussed.
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Battaglieri M, Brunoldi M, De Vita R, Laget JM, Osipenko M, Ripani M, Taiuti M, Adams G, Amaryan MJ, Anciant E, Anghinolfi M, Armstrong DS, Asavapibhop B, Asryan G, Audit G, Auger T, Avakian H, Barrow S, Beard K, Bektasoglu M, Berman BL, Bersani A, Bianchi N, Biselli AS, Boiarinov S, Bouchigny S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Burkert VD, Calarco JR, Capitani GP, Carman DS, Carnahan B, Cazes A, Cetina C, Cole PL, Coleman A, Cords D, Corvisiero P, Crabb D, Crannell H, Cummings JP, DeSanctis E, Degtyarenko PV, Demirchyan R, Denizli H, Dennis L, Dharmawardane KV, Dhuga KS, Djalali C, Dodge GE, Doughty D, Dragovitsch P, Dugger M, Dytman S, Eckhause M, Egiyan H, Egiyan KS, Elouadrhiri L, Farhi L, Feuerbach RJ, Ficenec J, Forest TA, Freyberger AP, Frolov V, Funsten H, Gaff SJ, Gai M, Garcon M, Gavalian G, Gilad S, Gilfoyle GP, Giovanetti KL, Golovach E, Griffioen K, Guidal M, Guillo M, Guo L, Gyurjyan V, Hadjidakis C, Hancock D, Hardie J, Heddle D, Hersman FW, Hicks K, Hicks RS, Holtrop M, Hyde-Wright CE, Ito MM, Joo K, Kelley JH, Khandaker M, Kim W, Klein A, Klein FJ, Klimenko AV, Klusman M, Kossov M, Kramer LH, Kuang Y, Kuhn SE, Lachniet J, Lawrence D, Lucas M, Lukashin K, Major RW, Manak JJ, Marchand C, McAleer S, McCarthy J, McNabb JWC, Mecking BA, Mestayer MD, Meyer CA, Mikhailov K, Mirazita M, Miskimen R, Mokeev V, Morrow S, Mozer MU, Muccifora V, Mueller J, Mutchler GS, Napolitano J, Nelson SO, Niccolai S, Niczyporuk BB, Niyazov RA, Nozar M, O'Brien JT, Opper AK, Peterson G, Philips SA, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Preedom BM, Price JW, Protopopescu D, Qin LM, Raue BA, Reolon AR, Riccardi G, Ricco G, Ritchie BG, Ronchetti F, Rossi P, Rowntree D, Rubin PD, Sabourov K, Salgado C, Sapunenko V, Schumacher RA, Serov VS, Shafi A, Sharabian YG, Shaw J, Skabelin AV, Smith ES, Smith T, Smith LC, Sober DI, Spraker M, Stavinsky A, Stepanyan S, Stoler P, Taylor S, Tedeschi DJ, Todor L, Thoma U, Thompson R, Vineyard MF, Vlassov AV, Wang K, Weinstein LB, Weller H, Weygand DP, Whisnant CS, Wolin E, Wood M, Yegneswaran A, Yun J, Zhang B, Zhao J, Zhou Z. Photoproduction of the omega meson on the proton at large momentum transfer. PHYSICAL REVIEW LETTERS 2003; 90:022002. [PMID: 12570539 DOI: 10.1103/physrevlett.90.022002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2002] [Indexed: 05/24/2023]
Abstract
The differential cross section, dsigma/dt, for omega meson exclusive photoproduction on the proton above the resonance region (2.6<W<2.9 GeV) was measured up to a momentum transfer -t=5 GeV2 using the CLAS detector at Jefferson Laboratory. The omega channel was identified by detecting a proton and pi(+) in the final state and using the missing mass technique. While the low momentum transfer region shows the typical diffractive pattern expected from Pomeron and Reggeon exchange, at large -t the differential cross section has a flat behavior. This feature can be explained by introducing quark interchange processes in addition to the QCD-inspired two-gluon exchange.
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Yun J, Yashin VV, Isayev AI. Ultrasonic devulcanization of carbon black-filled ethylene propylene diene monomer rubber. J Appl Polym Sci 2003. [DOI: 10.1002/app.13320] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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154
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Dugger M, Ritchie BG, Ball J, Pasyuk E, Adams G, Anciant E, Anghinolfi M, Asavapibhop B, Audit G, Auger T, Avakian H, Bagdasaryan H, Barrow S, Battaglieri M, Beard K, Bektasoglu M, Bellis M, Berman BL, Bianchi N, Biselli AS, Boiarinov S, Bouchigny S, Bradford R, Branford D, Briscoe WJ, Brooks WK, Burkert VD, Calarco JR, Capitani GP, Carman DS, Carnahan B, Cetina C, Clark R, Cole PL, Coleman A, Connelly J, Cords D, Corvisiero P, Crabb D, Crannell H, Cummings JP, DeSanctis E, DeVita R, Degtyarenko PV, Denizli H, Dennis L, Dharmawardane KV, Dhuga KS, Djalali C, Dodge GE, Doughty D, Dragovitsch P, Dytman S, Eckhause M, Egiyan H, Egiyan KS, Elouadrhiri L, Farhi L, Fatemi R, Feldman G, Feuerbach RJ, Ficenec J, Forest TA, Frolov V, Funsten H, Gaff SJ, Gai M, Gavalian G, Gilad S, Gilfoyle GP, Giovanetti KL, Girard P, Gordon CIO, Griffioen K, Guidal M, Guillo M, Guo L, Gyurjyan V, Hadjidakis C, Hancock D, Hardie J, Heddle D, Heimberg P, Hersman FW, Hicks K, Hicks RS, Holtrop M, Hyde-Wright CE, Ito MM, Jenkins D, Joo K, Kelley JH, Kellie JD, Khandaker M, Kim W, Klein A, Klein FJ, Klusman M, Kossov M, Koubarovski V, Kramer LH, Kuang Y, Kuhn SE, Kuhn J, Lachniet J, Laget JM, Lawrence D, Li J, Livingston K, Longhi A, Lucas M, Lukashin K, Major W, Manak JJ, Marchand C, McAleer S, McCarthy J, McNabb JWC, Mecking BA, Mehrabyan S, Mestayer MD, Meyer CA, Mikhailov K, Minehart R, Mirazita M, Miskimen R, Morand L, Morrow SA, Mozer MU, Muccifora V, Mueller J, Murphy LY, Mutchler GS, Napolitano J, Nasseripour R, Nelson SO, Niccolai S, Niculescu G, Niculescu I, Niczyporuk BB, Niyazov RA, Nozar M, O'Brien JT, O'Rielly GV, Opper AK, Park K, Peterson G, Philips SA, Pivnyuk N, Pocanić D, Pogorelko O, Polli E, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Qin LM, Raue BA, Riccardi G, Ricco G, Ripani M, Ronchetti F, Rossi P, Rowntree D, Rubin PD, Sabatié F, Sabourov K, Salgado C, Santoro JP, Sanzone-Arenhovel M, Sapunenko V, Schumacher RA, Serov VS, Shafi A, Sharabian YG, Shaw J, Skabelin AV, Smith ES, Smith T, Smith LC, Sober DI, Spraker M, Stavinsky A, Stepanyan S, Stoler P, Strakovsky II, Strauch S, Taiuti M, Taylor S, Tedeschi DJ, Thoma U, Thompson R, Todor L, Ungaro M, Vineyard MF, Vlassov AV, Wang K, Weinstein LB, Weller H, Weygand DP, Whisnant CS, Witkowski M, Wolin E, Wood MH, Yegneswaran A, Yun J, Zhang B, Zhao J, Zhou Z. Eta photoproduction on the proton for photon energies from 0.75 to 1.95 GeV. PHYSICAL REVIEW LETTERS 2002; 89:222002. [PMID: 12485062 DOI: 10.1103/physrevlett.89.222002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2002] [Indexed: 05/24/2023]
Abstract
Differential cross sections for gammap-->etap have been measured with tagged real photons for incident photon energies from 0.75 to 1.95 GeV. Mesons were identified by missing mass reconstruction using kinematical information for protons scattered in the production process. The data provide the first extensive angular distribution measurements for the process above W=1.75 GeV. Comparison with preliminary results from a constituent quark model support the suggestion that a third S11 resonance with mass approximately 1.8 GeV couples to the etaN channel.
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Joo K, Smith LC, Burkert VD, Minehart R, Aznauryan IG, Elouadrhiri L, Stepanyan S, Adams GS, Amaryan MJ, Anciant E, Anghinolfi M, Armstrong DS, Asavapibhop B, Audit G, Auger T, Avakian H, Barrow S, Bagdasaryan H, Battaglieri M, Beard K, Bektasoglu M, Bertozzi W, Bianchi N, Biselli AS, Boiarinov S, Bonner BE, Brooks WK, Calarco JR, Capitani GP, Carman DS, Carnahan B, Cole PL, Coleman A, Cords D, Corvisiero P, Crabb D, Crannell H, Cummings J, De Sanctis E, De Vita R, Degtyarenko PV, Demirchyan RA, Denizli H, Dennis LC, Deppman A, Dharmawardane KV, Dhuga KS, Djalali C, Dodge GE, Doughty D, Dragovitsch P, Dugger M, Dytman S, Eckhause M, Efremenko YV, Egiyan H, Egiyan KS, Farhi L, Feuerbach RJ, Ficenec J, Fissum K, Forest TA, Funsten H, Gai M, Gavrilov VB, Gilad S, Gilfoyle GP, Giovanetti KL, Girard P, Griffioen KA, Guidal M, Guillo M, Gyurjyan V, Hancock D, Hardie J, Heddle D, Heisenberg J, Hersman FW, Hicks K, Hicks RS, Holtrop M, Hyde-Wright CE, Ito MM, Jenkins D, Kelley JH, Khandaker M, Kim KY, Kim W, Klein A, Klein FJ, Klusman M, Kossov M, Kuang Y, Kuhn SE, Laget JM, Lawrence D, Longhi A, Loukachine K, Lucas M, Major RW, Manak JJ, Marchand C, Matthews SK, McAleer S, McNabb JWC, Mecking BA, Mestayer MD, Meyer CA, Mirazita M, Miskimen R, Muccifora V, Mueller J, Mutchler GS, Napolitano J, Niculescu G, Niczyporuk B, Niyazov RA, Ohandjanyan MS, Opper A, Patois Y, Peterson GA, Philips S, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Preedom BM, Price JW, Qin LM, Raue BA, Reolon AR, Riccardi G, Ricco G, Ripani M, Ritchie BG, Ronchetti F, Rossi P, Rowntree D, Rubin PD, Salgado CW, Sanzone M, Sapunenko V, Sargsyan M, Schumacher RA, Sharabian YG, Shaw J, Shuvalov SM, Skabelin A, Smith ES, Smith T, Sober DI, Spraker M, Stoler P, Taiuti M, Taylor S, Tedeschi D, Thompson R, Todor L, Tung TY, Vineyard MF, Vlassov A, Weller H, Weinstein LB, Welsh R, Weygand DP, Whisnant S, Witkowski M, Wolin E, Yegneswaran A, Yun J, Zhou Z, Zhao J. Q2 Dependence of quadrupole strength in the gamma*p --> Delta(+)(1232) --> p pi(0) transition. PHYSICAL REVIEW LETTERS 2002; 88:122001. [PMID: 11909446 DOI: 10.1103/physrevlett.88.122001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2001] [Indexed: 05/23/2023]
Abstract
Models of baryon structure predict a small quadrupole deformation of the nucleon due to residual tensor forces between quarks or distortions from the pion cloud. Sensitivity to quark versus pion degrees of freedom occurs through the Q2 dependence of the magnetic (M1+), electric (E1+), and scalar (S1+) multipoles in the gamma*p-->Delta(+)-->p pi(0) transition. We report new experimental values for the ratios E(1+)/M(1+) and S(1+)/M(1+) over the range Q2 = 0.4-1.8 GeV2, extracted from precision p(e,e(')p)pi(0) data using a truncated multipole expansion. Results are best described by recent unitary models in which the pion cloud plays a dominant role.
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De Vita R, Anghinolfi M, Burkert VD, Dodge GE, Minehart R, Taiuti M, Weller H, Adams G, Amaryan MJ, Anciant E, Armstrong DS, Asavapibhop B, Asryan G, Audit G, Auger T, Avakian H, Bagdasaryan H, Ball JP, Barrow S, Battaglieri M, Beard K, Bektasoglu M, Bianchi N, Biselli AS, Boiarinov S, Bonner BE, Bosted P, Bouchigny S, Branford D, Brooks WK, Bueltmann S, Calarco JR, Capitani GP, Carman DS, Carnahan B, Cazes A, Ciciani L, Cole PL, Coleman A, Connelly J, Cords D, Corvisiero P, Crabb D, Crannell H, Cummings JP, De Sanctis E, Degtyarenko PV, Demirchyan R, Denizli H, Dennis L, Dharmawardane KV, Dhuga KS, Djalali C, Doughty D, Dragovitsch P, Dugger M, Dytman S, Eckhause M, Egiyan H, Egiyan KS, Elouadrhiri L, Empl A, Farhi L, Fatemi R, Feuerbach RJ, Ficenec J, Forest TA, Frolov V, Funsten H, Gaff SJ, Gai M, Garçon M, Gavalian G, Gilad S, Gilfoyle GP, Giovanetti KL, Girard P, Golovatch E, Griffioen K, Guidal M, Guillo M, Gyurjyan V, Hadjidakis C, Hancock D, Hardie J, Heddle D, Heimberg P, Hersman FW, Hicks K, Hicks RS, Holtrop M, Hu J, Hyde-Wright CE, Ishkanov BS, Ito MM, Jenkins D, Joo K, Kelley JH, Kellie JD, Khandaker M, Kim KY, Kim K, Kim W, Klein A, Klein FJ, Klusman M, Kossov M, Kramer LH, Kuang Y, Kuhn SE, Lachniet J, Laget JM, Lawrence D, Li J, Livingston K, Longhi A, Loukachine K, Lucas M, Major W, Manak JJ, Marchand C, McAleer S, McCarthy J, McNabb JWC, Mecking BA, Mestayer MD, Meyer CA, Mikhailov K, Mirazita M, Miskimen R, Mokeev V, Muccifora V, Mueller J, Mutchler GS, Napolitano J, Nelson SO, Niculescu G, Niculescu I, Niczyporuk BB, Niyazov RA, Opper AK, O'Rielly GV, Osipenko M, Park K, Pasyuk E, Peterson G, Philips SA, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Pozdniakov S, Preedom BM, Price JW, Prok Y, Protopopescu D, Qin LM, Raue BA, Reolon AR, Riccardi G, Ricco G, Ripani M, Ritchie BG, Rock S, Ronchetti F, Rossi P, Rowntree D, Rubin PD, Sabatié F, Sabourov K, Salgado C, Sapunenko V, Sargsyan M, Schumacher RA, Serov VS, Shafi A, Sharabian YG, Shaw J, Skabelin AV, Smith ES, Smith T, Smith LC, Sober DI, Sorrell L, Spraker M, Stavinsky A, Stepanyan S, Stoler P, Strakovsky II, Taylor S, Tedeschi DJ, Thompson R, Todor L, Ungaro M, Vineyard MF, Vlassov AV, Wang K, Weinstein LB, Weisberg A, Weygand DP, Whisnant CS, Wolin E, Yegneswaran A, Yun J, Zhang B, Zhao J, Zhou Z. First measurement of the double spin asymmetry in (-->)e(-->)p-->e(prime)pi(+)n in the resonance region. PHYSICAL REVIEW LETTERS 2002; 88:082001. [PMID: 11863951 DOI: 10.1103/physrevlett.88.082001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2001] [Indexed: 05/23/2023]
Abstract
The double spin asymmetry in the (-->)e(-->)p --> e(prime)pi(+)n reaction has been measured for the first time in the resonance region for four-momentum transfer Q2 = 0.35-1.5 GeV(2). Data were taken at Jefferson Lab with the CLAS detector using a 2.6 GeV polarized electron beam incident on a polarized solid NH3 target. Comparison with predictions of phenomenological models shows strong sensitivity to resonance contributions. Helicity-1/2 transitions are found to be dominant in the second and third resonance regions. The measured asymmetry is consistent with a faster rise with Q(2) of the helicity asymmetry A1 for the F(15)(1680) resonance than expected from the analysis of the unpolarized data.
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157
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Ulrich DA, Ulrich BD, Angulo-Kinzler RM, Yun J. Treadmill training of infants with Down syndrome: evidence-based developmental outcomes. Pediatrics 2001; 108:E84. [PMID: 11694668 DOI: 10.1542/peds.108.5.e84] [Citation(s) in RCA: 190] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE On average, infants with Down syndrome (DS) learn to walk about 1 year later than nondisabled (ND) infants. The purpose of this study was to determine if practice stepping on a motorized treadmill could help reduce the delay in walking onset normally experienced by these infants. METHODS Thirty families of infants with DS were randomly assigned to the intervention or control group. All infants were karyotyped trisomy 21 and began participation in the study when they could sit alone for 30 seconds (Bayley Scales of Infant Development, Second Edition 1993, item 34). Infants received traditional physical therapy at least every other week. In addition, intervention infants received practice stepping on a small, motorized treadmill, 5 days per week, for 8 minutes a day, in their own homes. Parents were trained to support their infants on these specially engineered miniature treadmills. Every 2 weeks research staff went into the homes and tested infants' overall motor progress by administering the Bayley Scales of Infant Development, Second Edition, monitored growth status via a battery of 11 anthropometric measures, and checked parents' compliance with physical therapy and treadmill intervention. The primary measures of the intervention's effectiveness were comparisons between the groups on the length of time elapsed between sitting for 30 seconds (entry into the study) and 1) raising self to stand; 2) walking with help; and 3) walking independently. RESULTS The experimental group learned to walk with help and to walk independently significantly faster (73.8 days and 101 days, respectively) than the control group, both of which also produced large effect size statistics for the group differences. The groups were not statistically different for rate of learning to raise self to stand but there was a moderate effect size statistic suggesting that the groups were meaningfully different in favor of the experimental group. CONCLUSIONS These results provide evidence that, with training and support, parents can use these treadmills in their homes to help their infants with DS learn to walk earlier than they normally would. Current research is aimed at 1) improving the protocol to maximize outcome; 2) determining the impact of treadmill practice on walking gait patterns; 3) testing the application to other populations with a history of delays in walking; and 4) determining the long-term benefits that may accrue from this form of activity. motor development, Down syndrome, early intervention, walking.
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Battaglieri M, Anciant E, Anghinolfi M, De Vita R, Golovach E, Laget JM, Mokeev V, Ripani M, Adams G, Amaryan MJ, Armstrong DS, Asavapibhop B, Asryan G, Audit G, Auger T, Avakian H, Barrow S, Beard K, Bektasoglu M, Berman BL, Bianchi N, Biselli AS, Boiarinov S, Branford D, Briscoe WJ, Brooks WK, Burkert VD, Calarco JR, Capitani GP, Carman DS, Carnahan B, Cazes A, Cetina C, Cole PL, Coleman A, Cords D, Corvisiero P, Crabb D, Crannell H, Cummings JP, DeSanctis E, Degtyarenko PV, Demirchyan R, Denizli H, Dennis L, Dharmawardane KV, Dhuga KS, Djalali C, Dodge GE, Doughty D, Dragovitsch P, Dugger M, Dytman S, Eckhause M, Egiyan H, Egiyan KS, Elouadrhiri L, Farhi L, Feuerbach RJ, Ficenec J, Forest TA, Freyberger AP, Frolov V, Funsten H, Gaff SJ, Gai M, Gilad S, Gilfoyle GP, Giovanetti KL, Griffioen K, Guidal M, Guillo M, Gyurjyan V, Hancock D, Hardie J, Heddle D, Hersman FW, Hicks K, Hicks RS, Holtrop M, Hyde-Wright CE, Ito MM, Joo K, Kelley JH, Khandaker M, Kim W, Klein A, Klein FJ, Klusman M, Kossov M, Kramer LH, Kuang Y, Kuhn SE, Lawrence D, Lucas M, Lukashin K, Major RW, Manak JJ, Marchand C, McAleer S, McCarthy J, McNabb JW, Mecking BA, Mestayer MD, Meyer CA, Mikhailov K, Minehart R, Mirazita M, Miskimen R, Muccifora V, Mueller J, Mutchler GS, Napolitano J, Nelson SO, Niczyporuk BB, Niyazov RA, O'Brien JT, Opper AK, Peterson G, Philips SA, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Preedom BM, Price JW, Protopopescu D, Qin LM, Raue BA, Reolon AR, Riccardi G, Ricco G, Ritchie BG, Ronchetti F, Rossi P, Rowntree D, Rubin PD, Sabourov K, Salgado C, Sanzone-Arenhovel M, Sapunenko V, Schumacher RA, Serov VS, Shafi A, Sharabian YG, Shaw J, Skabelin AV, Smith ES, Smith T, Smith LC, Sober DI, Spraker M, Stavinsky A, Stepanyan S, Stoler P, Taiuti M, Taylor S, Tedeschi DJ, Todor L, Thompson R, Vineyard MF, Vlassov AV, Weinstein LB, Weisberg A, Weller H, Weygand DP, Whisnant CS, Wolin E, Wood M, Yegneswaran A, Yun J, Zhang B, Zhao J, Zhou Z. Photoproduction of the rho(0) meson on the proton at large momentum transfer. PHYSICAL REVIEW LETTERS 2001; 87:172002. [PMID: 11690264 DOI: 10.1103/physrevlett.87.172002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2001] [Indexed: 05/23/2023]
Abstract
The differential cross section, d sigma/dt, for rho(0) meson photoproduction on the proton above the resonance region was measured up to a momentum transfer -t = 5 GeV2 using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The rho(0) channel was extracted from the measured two charged-pion cross sections by fitting the pi(+)pi(-) and p pi(+) invariant masses. The low momentum transfer region shows the typical diffractive pattern expected from Reggeon exchange. The flatter behavior at large -t cannot be explained solely in terms of QCD-inspired two-gluon exchange models. The data indicate that other processes, like quark interchange, are important to fully describe rho photoproduction.
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Jung MS, Yun J, Chae HD, Kim JM, Kim SC, Choi TS, Shin DY. p53 and its homologues, p63 and p73, induce a replicative senescence through inactivation of NF-Y transcription factor. Oncogene 2001; 20:5818-25. [PMID: 11593387 DOI: 10.1038/sj.onc.1204748] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2001] [Revised: 06/18/2001] [Accepted: 06/26/2001] [Indexed: 12/31/2022]
Abstract
Recent studies have identified two p53 homologues, p63 and p73. They activate p53-responsive promoters and induce apoptosis when overexpressed in certain human tumors. Here, we report that p63, like p53 and p73, induces replicative senescence when expressed in a tetracycline-regulated manner in EJ cells lacking a functional p53. In addition to transcription activation of p53-responsive genes, we found that p63 and p73 repress transcription of the cdk1 and cyclin B genes, both of which are irreversibly repressed in senescent human fibroblast. In transient transfection assay, p63 and p73 repress the cdk1 promoter regardless of the presence of a dominant negative mutant form of p53. Furthermore, we found that DNA binding activity of NF-Y transcription factor, which is essential for transcription of the cdk1 and cyclin B genes and inactivated in senescent fibroblast, is significantly decreased by expression of either of p53, p63, or p73. Since NF-Y binds to many promoters besides the cdk1 and cyclin B promoters, inactivation of NF-Y by p53 family genes may be a general mechanism for transcription repression in replicative senescence.
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160
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Waugh DJ, Gaivin RJ, Zuscik MJ, Gonzalez-Cabrera P, Ross SA, Yun J, Perez DM. Phe-308 and Phe-312 in transmembrane domain 7 are major sites of alpha 1-adrenergic receptor antagonist binding. Imidazoline agonists bind like antagonists. J Biol Chem 2001; 276:25366-71. [PMID: 11331292 DOI: 10.1074/jbc.m103152200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Although agonist binding in adrenergic receptors is fairly well understood and involves residues located in transmembrane domains 3 through 6, there are few residues reported that are involved in antagonist binding. In fact, a major docking site for antagonists has never been reported in any G-protein coupled receptor. It has been speculated that antagonist binding is quite diverse depending upon the chemical structure of the antagonist, which can be quite different from agonists. We now report the identification of two phenylalanine residues in transmembrane domain 7 of the alpha(1a)-adrenergic receptor (Phe-312 and Phe-308) that are a major site of antagonist affinity. Mutation of either Phe-308 or Phe-312 resulted in significant losses of affinity (4-1200-fold) for the antagonists prazosin, WB4101, BMY7378, (+) niguldipine, and 5-methylurapidil, with no changes in affinity for phenethylamine-type agonists such as epinephrine, methoxamine, or phenylephrine. Interestingly, both residues are involved in the binding of all imidazoline-type agonists such as oxymetazoline, cirazoline, and clonidine, confirming previous evidence that this class of ligand binds differently than phenethylamine-type agonists and may be more antagonist-like, which may explain their partial agonist properties. In modeling these interactions with previous mutagenesis studies and using the current backbone structure of rhodopsin, we conclude that antagonist binding is docked higher in the pocket closer to the extracellular surface than agonist binding and appears skewed toward transmembrane domain 7.
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161
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Fischbein MP, Yun J, Laks H, Irie Y, Fishbein MC, Espejo M, Bonavida B, Ardehali A. CD8+ lymphocytes augment chronic rejection in a MHC class II mismatched model. Transplantation 2001; 71:1146-53. [PMID: 11374417 DOI: 10.1097/00007890-200104270-00023] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
UNLABELLED Chronic rejection, or cardiac allograft vasculopathy (CAV), remains the leading cause of late death in heart transplant recipients. The precise role and contributions of T lymphocyte subsets to CAV development remains unknown. METHODS Donor hearts from B6.C-H2bm12 mice were transplanted into T lymphocyte subset knockout recipients and T lymphocyte-reconstituted nude recipients. No immunosuppression was used. Intimal proliferation was measured morphometrically. In vitro studies were performed to analyze the donor-specific activation status of recipient CD8+ lymphocytes by examining cellular proliferation, interleukin-2 secretion, and interleukin-2Ralpha expression. Intracellular cytokine staining assay was performed to determine both the profile and source of intragraft cytokines. RESULTS Hearts transplanted into wild-type recipients developed severe CAV by 24 days. Intimal lesions were absent in the hearts that were transplanted into nude and CD4-/- knockout mice (containing CD8+ lymphocytes). In contrast, the donor hearts in CD8-/- knockout recipients (containing CD4+ lymphocytes) developed CAV, but significantly less than in wildtype. Adoptive transfer of T lymphocyte subset populations into nude recipients confirmed that CAV was absolutely contingent on CD4+ lymphocytes, and that CD8+ lymphocytes played an additive role in intimal lesion progression in the presence of CD4+ lymphocytes. Although CD8+ lymphocytes alone did not cause CAV in vivo, we demonstrated that MHC class II disparate alloantigens activated CD8+ lymphocytes both in vivo and in vitro. Finally, both CD4+ and CD8+ lymphocytes contributed to the intragraft IL-2 and IFN-gamma production. CONCLUSIONS In this MHC class II mismatched murine model, CAV is a T lymphocyte dependent event, and absolutely contingent on the presence of CD4+ lymphocytes. Furthermore, CD8+ lymphocytes (1) are activated by MHC class II disparate antigens and (2) play a significant role in the progression of lesion development. Finally, both CD4+ and CD8+ lymphocytes contribute to CAV development via secretion of IFN-gamma, a known mediator of CAV in this model.
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162
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Bourbon NA, Yun J, Berkey D, Wang Y, Kester M. Inhibitory actions of ceramide upon PKC-epsilon/ERK interactions. Am J Physiol Cell Physiol 2001; 280:C1403-11. [PMID: 11350735 DOI: 10.1152/ajpcell.2001.280.6.c1403] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have previously shown that interleukin-1 receptor-generated ceramide induces growth arrest in smooth muscle pericytes by inhibiting an upstream kinase in the extracellular signal-regulated kinase (ERK) cascade. Here, we now report the mechanism by which ceramide inhibits ERK activity. Ceramide renders the human embryonic kidney 293 cells (HEK 293) resistant to the mitogenic actions of growth factors and activators of protein kinase C (PKC). A role for PKC to mediate ceramide inhibition of growth factor-induced ERK activity and mitogenesis is suggested, as exogenous ceramide directly inhibits both immunoprecipitated and recombinant PKC-epsilon activities. To confirm that PKC-epsilon is necessary for ceramide-inhibited ERK activity, HEK 293 cells were transfected with a dominant-negative mutant of PKC-epsilon (DeltaPKC-epsilon). These transfected cells respond to insulin-like growth factor I (IGF-I) with a significantly decreased ERK activity that is not further reduced by ceramide treatment. Coimmunoprecipitation studies reveal that the treatment with IGF-I induces the association of ERK with PKC-epsilon but not with PKC-zeta. Ceramide treatment significantly inhibits the IGF-I-induced PKC-epsilon interaction with bioactive phosphorylated ERK. Ceramide also inhibits IGF-I-induced PKC-epsilon association with Raf-1, an upstream kinase of ERK. Together, these studies demonstrate that ceramide exerts anti-mitogenic actions by limiting the ability of PKC-epsilon to form a signaling complex with Raf-1 and ERK.
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163
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Kang JG, Yun J, Kim DH, Chung KS, Fujioka S, Kim JI, Dae HW, Yoshida S, Takatsuto S, Song PS, Park CM. Light and brassinosteroid signals are integrated via a dark-induced small G protein in etiolated seedling growth. Cell 2001; 105:625-36. [PMID: 11389832 DOI: 10.1016/s0092-8674(01)00370-1] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Plant growth and development are regulated through coordinated interactions between light and phytohormones. Here, we demonstrate that a dark-induced small G protein, pea Pra2, regulates a variant cytochrome P450 that catalyzes C-2 hydroxylation in brassinosteroid biosynthesis. The cytochrome P450 is dark-induced and predominantly expressed in the rapidly elongating zone of etiolated pea epicotyls, where Pra2 is also most abundant. Transgenic plants with reduced Pra2 exhibit a dark-specific dwarfism, which is completely rescued by exogenous brassinolide. Overexpression of the cytochrome P450 results in enhanced hypocotyl growth even in the light, which phenocopies the etiolated hypocotyls. We therefore propose that Pra2 and its orthologs are molecular mediators for the cross-talk between light and brassinosteroids in the etiolation process in plants.
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164
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Yun J, Oh SR, Lee HK, Chang IM, Takatsu K, Yun YP, Min KR, Kim Y. Effect of genistein analogs on oxygen radical production in leukocytes stimulated by unopsonized zymosan. PLANTA MEDICA 2001; 67:274-276. [PMID: 11345702 DOI: 10.1055/s-2001-12002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Effects of genistein analogs on oxygen radical production have been analyzed in human neutrophils, human monocytes or murine macrophages Raw264.7 stimulated with unopsonized zymosan by lucigenin- and luminol-enhanced chemiluminescence assays. Genistein exhibited IC50 values of 10.7-11.5 microM on the oxygen radical production in human neutrophils, 10.9-11.0 microM in human monocytes, and 14.8-27.3 microM in Raw264.7 cells. Orobol, a genistein analog with an additional hydroxy group at the 3' position, exhibited IC50 values of 3.0-3.3 microM on the oxygen radical production in human neutrophils, 2.8-3.1 microM in human monocytes, and 1.5-3.9 microM in Raw264.7 cells. Genistin and sophoricoside are genistein glycosides with a glucose moiety at 7 or 4' position, respectively. The genistein glycosides exhibited 23-37% inhibitory effects at 100 microM on the oxygen radical production.
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165
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Yun J, Buchwald SL. One-Pot Synthesis of Enantiomerically Enriched 2,3-Disubstituted Cyclopentanones via Copper-Catalyzed 1,4-Reduction and Alkylation. Org Lett 2001; 3:1129-31. [PMID: 11348176 DOI: 10.1021/ol015577f] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text]. Enantiomerically enriched 2,3-disubstituted cyclopentanones were prepared via copper-catalyzed 1,4-reduction of 3-substituted cyclopentenones followed by alkylation of the resulting silyl enol ether. Using this procedure, trans-2,3-disubstituted cyclopentanones were produced in moderate to good overall yields (42-67%) and with excellent enantiomeric and diastereomeric excesses. The reduction and alkylation were performed in a single reaction vessel.
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166
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Thompson R, Dytman S, Kim KY, Mueller J, Adams GS, Amaryan MJ, Anciant E, Anghinolfi M, Asavapibhop B, Auger T, Audit G, Avakian H, Barrow S, Battaglieri M, Beard K, Bektasoglu M, Bertozzi W, Bianchi N, Biselli A, Boiarinov S, Bonner BE, Briscoe WJ, Brooks W, Burkert VD, Calarco JR, Capitani G, Carman DS, Carnahan B, Cole PL, Coleman A, Connelly J, Cords D, Corvisiero P, Crabb D, Crannell H, Cummings J, Day D, Degtyarenko PV, Demirchyan RA, Dennis LC, Deppman A, De Sanctis E, De Vita R, Dhuga KS, Djalali C, Dodge GE, Doughty D, Dragovitsch P, Dugger M, Eckhause M, Efremenko YV, Egiyan H, Egiyan KS, Elouadrhiri L, Farhi L, Feuerbach RJ, Ficenec J, Fissum K, Freyberger A, Funsten H, Gai M, Gavrilov VB, Gilfoyle GP, Giovanetti K, Gilad S, Girard P, Griffioen KA, Guidal M, Guillo M, Gyurjyan V, Hancock D, Hardie J, Heddle D, Heisenberg J, Hersman FW, Hicks K, Hicks RS, Holtrop M, Hyde-Wright CE, Ito MM, Jenkins D, Joo K, Kane J, Khandaker M, Kim W, Klein A, Klein FJ, Klusman M, Kossov M, Kuhn SE, Kuang Y, Laget JM, Lawrence D, Leskin GA, Longhi A, Loukachine K, Lucas M, Magahiz R, Major RW, Manak JJ, Marchand C, Matthews SK, McAleer S, McCarthy J, McNabb JW, Mecking BA, Mestayer MD, Meyer CA, Minehart R, Mirazita M, Miskimen R, Muccifora V, Mutchler GS, Napolitano J, Niyazov RA, Ohandjanyan MS, O'Brien JT, Opper A, Patois Y, Peterson GA, Philips S, Pivnyuk N, Pocanic D, Pogorelko O, Polli E, Preedom BM, Price JW, Qin LM, Raue BA, Reolon AR, Riccardi G, Ricco G, Ripani M, Ritchie BG, Ronchetti F, Rossi P, Roudot F, Rowntree D, Rubin PD, Salgado CW, Sanzone M, Sapunenko V, Sarty A, Sargsyan M, Schumacher RA, Shafi A, Sharabian YG, Shaw J, Shuvalov SM, Skabelin A, Smith T, Smith C, Smith ES, Sober DI, Spraker M, Stepanyan S, Stoler P, Taiuti M, Taylor S, Tedeschi D, Tung TY, Vineyard MF, Vlassov A, Weller H, Weinstein LB, Welsh R, Weygand DP, Whisnant S, Witkowski M, Wolin E, Yegneswaran A, Yun J, Zhou Z, Zhao J. The ep -->e'p eta reaction at and above the S11(1535) baryon resonance. PHYSICAL REVIEW LETTERS 2001; 86:1702-1706. [PMID: 11290228 DOI: 10.1103/physrevlett.86.1702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2000] [Indexed: 05/23/2023]
Abstract
New cross sections for the reaction e p-->e p eta are reported for total center of mass energy W = 1.5--1.86 GeV and invariant momentum transfer Q2 = 0.25--1.5 (GeV/c)(2). This large kinematic range allows extraction of important new information about response functions, photocouplings, and eta N coupling strengths of baryon resonances. Newly observed structure at W approximately 1.65 GeV is shown to come from interference between S and P waves and can be interpreted with known resonances. Improved values are derived for the photon coupling amplitude for the S11(1535) resonance.
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167
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Fischbein MP, Yun J, Laks H, Fishbein MC, Irie Y, Wortham C, Bonavida B, Ardehali A. CD8+ lymphocytes participate in the development of chronic rejection. J Heart Lung Transplant 2001; 20:228-229. [PMID: 11250432 DOI: 10.1016/s1053-2498(00)00507-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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168
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Fischbein MP, Ardehali A, Yun J, Schoenberger S, Laks H, Irie Y, Dempsey P, Cheng G, Fishbein MC, Bonavida B. CD40 signaling replaces CD4+ lymphocytes and its blocking prevents chronic rejection of heart transplants. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:7316-22. [PMID: 11120867 DOI: 10.4049/jimmunol.165.12.7316] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Chronic rejection remains the major obstacle to long term survival in heart transplant recipients. The cellular and molecular mechanisms that underlie chronic rejection are not known, and their discovery can form the basis of clinical intervention. Several investigators have suggested that the development of chronic rejection in solid organ transplants is dependent on help mediated by CD4(+) lymphocytes. Importantly, the mechanism through which help is provided has not been fully delineated in transplant rejection. Using a murine heterotopic heart transplant model without immunosuppression, this study defines the functional role of CD4(+) lymphocytes in chronic rejection. In an MHC class II-mismatched model, we demonstrate that chronic rejection was absolutely contingent on the presence of CD4(+) lymphocytes. Importantly, here we report that signaling through CD40 can replace the requirement of CD4(+) lymphocytes, demonstrated by the development of chronic rejection in CD4 knockout recipients treated with a CD40-activating mAb (FGK45). The return of rejection appears to be a CD8(+) lymphocyte-dependent process, noted by the absence of rejection in FGK45-treated recombinase-activated gene knockout (CD4(+) and CD8(+) lymphocyte-deficient) recipients. The CD40 signaling pathway works independently of B7-CD28 costimulation, as indicated by the development of severe chronic rejection in CD28 knockout recipients. Importantly, this study provides evidence that CD40 ligand-targeted therapies may prevent chronic rejection only in strain combinations where CD4(+) lymphocyte help is absolutely required.
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MESH Headings
- Animals
- Antibodies, Blocking/administration & dosage
- Antibodies, Monoclonal/pharmacology
- Antigens, CD/physiology
- B-Lymphocytes/immunology
- B7-1 Antigen/physiology
- B7-2 Antigen
- CD28 Antigens/physiology
- CD4-Positive T-Lymphocytes/immunology
- CD40 Antigens/immunology
- CD40 Antigens/metabolism
- CD40 Antigens/physiology
- CD40 Ligand/genetics
- CD40 Ligand/immunology
- Chronic Disease
- Coronary Disease/genetics
- Coronary Disease/immunology
- Coronary Disease/physiopathology
- Coronary Disease/prevention & control
- DNA-Binding Proteins/deficiency
- DNA-Binding Proteins/genetics
- Disease Models, Animal
- Graft Rejection/immunology
- Graft Rejection/physiopathology
- Graft Rejection/prevention & control
- Heart Transplantation/immunology
- Histocompatibility Antigens Class I/genetics
- Histocompatibility Antigens Class I/immunology
- Histocompatibility Testing
- Homeodomain Proteins/genetics
- Immune Sera/administration & dosage
- Injections, Intraperitoneal
- Injections, Intravenous
- Lymphopenia/genetics
- Lymphopenia/immunology
- Lymphopenia/physiopathology
- Membrane Glycoproteins/physiology
- Mice
- Mice, Inbred A
- Mice, Inbred C57BL
- Mice, Knockout
- Signal Transduction/immunology
- Transplantation, Homologous
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169
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Yun J, Schöneberg T, Liu J, Schulz A, Ecelbarger CA, Promeneur D, Nielsen S, Sheng H, Grinberg A, Deng C, Wess J. Generation and phenotype of mice harboring a nonsense mutation in the V2 vasopressin receptor gene. J Clin Invest 2000; 106:1361-71. [PMID: 11104789 PMCID: PMC381460 DOI: 10.1172/jci9154] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The V2 vasopressin receptor (V2R) plays a key role in the maintenance of a normal body water balance. To generate an in vivo model that allows the physiological and molecular analysis of the role of V2Rs in kidney function, we have created mouse lines that lack functional V2Rs by using targeted mutagenesis in mouse embryonic stem cells. Specifically, we introduced a nonsense mutation known to cause X-linked nephrogenic diabetes insipidus (XNDI) in humans (Glu242stop) into the mouse genome. V2R-deficient hemizygous male pups showed a decrease in basal urine osmolalities and were unable to concentrate their urine. These pups also exhibited an enlargement of renal pelvic space, failed to thrive, and died within the first week after birth due to hypernatremic dehydration. Interestingly, female mice heterozygous for the V2R mutation showed normal growth but displayed an XNDI-like phenotype, characterized by reduced urine concentrating ability of the kidney, polyuria, and polydipsia. Western blot analysis and immunoelectron microscopic studies showed that the loss of functional V2Rs had no significant effect on the basal expression levels of aquaporin-2 and the bumetanide-sensitive Na-K-2Cl cotransporter (BSC-1). The V2R mutant mice described here should serve as highly useful tools for the development of novel therapeutic strategies for the treatment of XNDI.
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170
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Bourbon NA, Yun J, Kester M. Ceramide directly activates protein kinase C zeta to regulate a stress-activated protein kinase signaling complex. J Biol Chem 2000; 275:35617-23. [PMID: 10962008 DOI: 10.1074/jbc.m007346200] [Citation(s) in RCA: 179] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have previously shown that interleukin 1 (IL-1)-receptor-generated ceramide induces growth arrest in smooth muscle pericytes by activating an upstream kinase in the stress-activated protein kinase (SAPK) cascade. We now report the mechanism by which ceramide activates the SAPK signaling pathway in human embryonic kidney cells (HEK-293). We demonstrate that ceramide activation of protein kinase C zeta (PKCzeta) mediates SAPK signal complex formation and subsequent growth suppression. Ceramide directly activates both immunoprecipitated and recombinant human PKCzeta in vitro. Additionally, ceramide activates SAPK activity, which is blocked with a dominant-negative mutant of PKCzeta. Co-immunoprecipitation studies reveal that ceramide induces the association of SAPK with PKCzeta, but not with PKCepsilon. In addition, ceramide treatment induces PKCzeta association with phosphorylated SEK and MEKK1, elements of the SAPK signaling complex. The biological role of ceramide to induce cell cycle arrest is mimicked by overexpression of a constitutively active PKCzeta. Together, these studies demonstrate that ceramide induces cell cycle arrest by enhancing the ability of PKCzeta to form a signaling complex with MEKK1, SEK, and SAPK.
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171
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Yun J, Lee CK, Chang IM, Takatsu K, Hirano T, Min KR, Lee MK, Kim Y. Differential inhibitory effects of sophoricoside analogs on bioactivity of several cytokines. Life Sci 2000; 67:2855-63. [PMID: 11106000 DOI: 10.1016/s0024-3205(00)00873-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Effects of sophoricoside and its analogs on proinflammatory cytokines have been investigated. Sophoricoside, genistein and orobol exhibited inhibitory effects on IL-5, IL-3, GM-CSF and IL-6 bioactivities. Genistin showed inhibitory effects on IL-5 and IL-3 bioactivities, but did not inhibit GM-CSF and IL-6 bioactivities. None of the sophoricoside analogs showed inhibitory effects on both IL-1beta and TNF-alpha bioactivities. Among the compounds, sophoricoside exhibited the highest inhibitory effects on IL-5, IL-3 and IL-6 bioactivities with IC50 values of 1.9 microM, 6.9 microM and 6.0 microM, respectively and orobol did show on GM-CSF bioactivity with an IC50 value of 18.0 microM. The result would provide an additional mechanism by which the compounds exert immunosuppressive and anti-inflammatory effects.
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172
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Charles R, Sandirasegarane L, Yun J, Bourbon N, Wilson R, Rothstein RP, Levison SW, Kester M. Ceramide-coated balloon catheters limit neointimal hyperplasia after stretch injury in carotid arteries. Circ Res 2000; 87:282-8. [PMID: 10948061 DOI: 10.1161/01.res.87.4.282] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Neointimal hyperplasia at the site of surgical intervention is a common and deleterious complication of surgery for cardiovascular diseases. We hypothesized that direct delivery of a cell-permeable growth-arresting lipid via the balloon tip of an embolectomy catheter would limit neointimal hyperplasia after stretch injury. We have previously demonstrated that sphingolipid-derived ceramide arrested the growth of smooth muscle cell pericytes in vitro. Here, we show that ceramide-coated balloon catheters significantly reduced neointimal hyperplasia induced by balloon angioplasty in rabbit carotid arteries in vivo. This ceramide treatment decreased the number of vascular smooth muscle cells entering the cell cycle without inducing apoptosis. In situ autoradiographic studies demonstrated that inflating the balloon catheter forced cell-permeable ceramide into the intimal and medial layers of the artery. Intercalation of ceramide into vascular smooth muscle cells correlated with rapid inhibition of trauma-associated phosphorylation of extracellular signal-regulated kinase and protein kinase B. These studies demonstrate the utility of cell-permeable ceramide as a novel therapy for reducing neointimal hyperplasia after balloon angioplasty.
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MESH Headings
- Angioplasty, Balloon, Coronary/adverse effects
- Angioplasty, Balloon, Coronary/methods
- Animals
- Apoptosis/physiology
- Carotid Artery Injuries/drug therapy
- Carotid Artery Injuries/metabolism
- Carotid Artery Injuries/pathology
- Carotid Stenosis/drug therapy
- Carotid Stenosis/metabolism
- Carotid Stenosis/pathology
- Ceramides/pharmacology
- Disease Models, Animal
- Hyperplasia
- Mitogen-Activated Protein Kinases/metabolism
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/injuries
- Muscle, Smooth, Vascular/pathology
- Postoperative Complications/drug therapy
- Postoperative Complications/pathology
- Postoperative Complications/prevention & control
- Rabbits
- Tunica Intima/enzymology
- Tunica Intima/injuries
- Tunica Intima/pathology
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173
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Yun J. Micellar colorimetric determination of iron, cobalt, nickel and copper using 1-nitroso-2-naphthol. Talanta 2000; 52:893-902. [DOI: 10.1016/s0039-9140(00)00441-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/1999] [Revised: 05/02/2000] [Accepted: 05/11/2000] [Indexed: 10/17/2022]
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174
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Liao Z, Qi Z, Sun M, Yang D, Yun J. [The influences of human apolipoprotein E mutants on the learning and memory of cerebral cortex in transgenic mice]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 2000; 22:348-51. [PMID: 12903448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
OBJECTIVE To study the influences of the mutants of human apolipoprotein E on the function of cerebral cortex. METHODS The Southern blot hybridization and ELISA techniques were used for identification of integration and expression of human apoE4 and apoE7 genes at the mice chromosome and in the serum of F1 transgenic mice. Then the active avoidance response test was performed to determine the alteration of learning and short term and long term memory of the transgenic mice. The serum total cholesterol (TC) and triglyceride (TG) were determined simultaneously with enzymatic procedure. RESULTS (1) In F1 transgenic mice the human apoE genes integrated at the chromosome and expressed in their serum stably. (2) In apoE4 mice the learning and short term memorizing abilities were decreased, and in apoE7 mice the short term memorizing abilities were decreased as well. In addition, the TC and TG increased statistically. CONCLUSIONS The overexpression of human apoE4 and apoE7 genes in transgenic mice could damage the function of cerebral cortex. It denoted that the mutations of apoE might correlate the pathogenesis of Alzheimer's disease.
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175
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Abstract
The efficient kinetic resolution of 2,5-disubstituted pyrrolines was accomplished by employing hydrosilylation with a chiral catalyst, (EBTHI)TiF2 (EBTHI = ethylenebis(tetrahydroindenyl)). An interesting isomerization reaction of the cyclic imines catalyzed by the same chiral catalyst was also discovered.
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176
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Crish JF, Bone F, Balasubramanian S, Zaim TM, Wagner T, Yun J, Rorke EA, Eckert RL. Suprabasal expression of the human papillomavirus type 16 oncoproteins in mouse epidermis alters expression of cell cycle regulatory proteins. Carcinogenesis 2000; 21:1031-7. [PMID: 10783329 DOI: 10.1093/carcin/21.5.1031] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Human papillomavirus (HPV) survives by reactivating DNA replication in post-mitotic cells. In the present study, we describe a mouse model of HPV-dependent disease. In these mice, DNA synthesis is activated in suprabasal keratinocytes, leading to acanthosis, parakeratosis and enhanced desquamation. The full-length E6/E7 transcript and two alternately spliced products are produced and in most lines the predominant product is E6*. In the present study, we examine the effects of E6/E7 on cell cycle regulatory protein expression. E6/E7 expression in mouse epidermis is correlated with increased levels of the p53, p21, p27, cdk2, cdk4, cdk6, cyclin D1 and cyclin E regulatory proteins. Hyperproliferation is also observed in the buccal mucosa and the tongue epithelia of E6/E7 mice, and p53 levels are markedly increased in these epithelia. These results suggest that the major changes in cell cycle regulatory protein expression are in response to the presence of E7 and that E6 has a lesser impact.
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177
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Yun J, Buchwald SL. Efficient kinetic resolution in the asymmetric hydrosilylation of imines of 3-substituted indanones and 4-substituted tetralones. J Org Chem 2000; 65:767-74. [PMID: 10814009 DOI: 10.1021/jo991328h] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Kinetic resolution of the N-methyl imines of 3-substituted indanones and 4-substituted tetralones could be accomplished by hydrosilylation with a chiral titanocene catalyst. N-Methyl imines of 4-substituted tetralones were resolved to yield, after hydrolysis of the unreacted starting materials, ketones with high ee's and the amine products with high diastereomeric and enantiomeric purity. The utility of this process was demonstrated in the synthesis of sertraline.
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178
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Park M, Chae HD, Yun J, Jung M, Kim YS, Kim SH, Han MH, Shin DY. Constitutive activation of cyclin B1-associated cdc2 kinase overrides p53-mediated G2-M arrest. Cancer Res 2000; 60:542-5. [PMID: 10676633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Recent studies have suggested that p53 regulates the G2 checkpoint in the cell cycle and that this function is required for the maintenance of genomic integrity. In this study, we investigated a regulatory role of p53 specifically in G2-M transition. Human bladder carcinoma cells lacking functional p53 were synchronized at G1-S, which is preceded by p53-mediated G1 arrest. p53 expression in the synchronized cells was induced by infection with a recombinant adenovirus that encodes p53. After release from the G1-S arrest, the cells progressed to S-phase and G2 but failed to enter mitosis. Biochemical analysis showed that p53 inhibits cell cycle-dependent expression of cdc2 and cyclin B1 and consequently inhibits cdc2 kinase. The role of cyclin B1-associated cdc2 kinase in p53-mediated G2-M arrest was further investigated by expression of both cyclin B1 and cdc2AF, in which inhibitory phosphorylation sites were substituted. The cells expressing both cdc2AF and cyclin B1 showed a constitutive activation of cdc2 kinase during cell cycle progression and passed through G2-M regardless of p53 expression. Therefore, inactivation of cdc2 kinase through cdc2 and cyclin B1 repression is an essential step in p53-mediated G2-M arrest.
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179
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Kim Y, Jang DS, Park SH, Yun J, Min BK, Min KR, Lee HK. Flavonol glycoside gallate and ferulate esters from Persicaria lapathifolia as inhibitors of superoxide production in human monocytes stimulated by unopsonized zymosan. PLANTA MEDICA 2000; 66:72-74. [PMID: 10705740 DOI: 10.1055/s-0029-1243112] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Aerial parts of Persicaria lapathifolia S.F. Gray (Polygonaceae) exhibited an inhibitory effect on superoxide production in unopsonized zymosan-stimulated human monocytes. Two known compounds, quercetin 3-O-beta-(2"-galloyl)-glucopyranoside and quercetin 3-O-beta-(2"-galloyl)-rhamnopyranoside, and a new compound, quercetin 3-O-beta-(6"-feruloyl)-galactopyranoside, were isolated as the inhibitors of superoxide production by activity-guided fractionation. IC50 values were shown at the concentrations of 2.1 microM by quercetin 3-O-beta-(2"-galloyl)-glucopyranoside, 1.9 microM by quercetin 3-O-beta-(2"-galloyl)-rhamnoypranoside, and 3.5 microM by quercetin 3-O-beta-(6"-feruloyl)-galactopyranoside whose inhibitory potencies were similar to oxyphenylbutazone (IC50 = 1.9 microM) as a positive control.
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180
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Yun J, Kim W, Ha SC, Eom SH, Suh SW, Kim KK. Crystallization and preliminary crystallographic studies of ribosome recycling factor from Escherichia coli. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2000; 56:84-5. [PMID: 10666636 DOI: 10.1107/s0907444999013906] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Ribosome recycling factor (RRF) catalyzes the disassembly of a termination complex during the final stage of protein synthesis. RRF from Escherichia coli has been crystallized with PEG 400 as precipitant at 287 K. The crystal belongs to the trigonal space group P3(1)21 (or P3(2)21), with unit-cell parameters a = b = 48.08, c = 141.67 A. Native data were collected from a frozen crystal to a resolution of 3.0 A on a Cu Kalpha rotating-anode X-ray source.
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Seo B, Yun J, Lee S, Kim M, Hwang K, Kim J, Min KR, Kim Y, Moon D. Barbarin as a new tyrosinase inhibitor from Barbarea orthocerus. PLANTA MEDICA 1999; 65:683-686. [PMID: 10630104 DOI: 10.1055/s-1999-14092] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A tyrosinase inhibitor was isolated from the whole plant of Barbarea orthocerus Led. (Brassicaceae) by activity-guided fractionation, and identified as (R)-5-phenyl-2-oxazolidinethione (barbarin) by structural analysis followed by comparison with reported spectral data. The compound exhibited significant inhibitory effects on mushroom and murine tyrosinases at more than 1.6 x 10(-5) M. Barbarin exhibited IC50 values of 4.2 x 10(-5) M on mushroom tyrosinase and of 4.8 x 10(-5) M on murine tyrosinase. Kojic acid as a positive control exhibited IC50 values of 3.4 x 10(-5) M and 6.0 x 10(-5) M on mushroom and murine tyrosinases, respectively. Therefore, barbarin exhibited a similar level of inhibitory potency with kojic acid used as a positive control. In a kinetic study with various concentrations of L-dopa as the substrate, barbarin was identified as an uncompetitive inhibitor and kojic acid as a mixed inhibitor of both mushroom and murine tyrosinases. Barbarin exhibited KEIS values of 3.3 x 10(-5) M and 3.6 x 10(-5) M on mushroom and murine tyrosinases, respectively. Kojic acid exhibited KEIS and KEI values of 2.4 x 10(-5) M and 2.2 x 10(-5) M on mushroom tyrosinase and those of 8.9 x 10(-5) M and 7.2 x 10(-5) M on murine tyrosinase, respectively.
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Yun J, Chae HD, Choy HE, Chung J, Yoo HS, Han MH, Shin DY. p53 negatively regulates cdc2 transcription via the CCAAT-binding NF-Y transcription factor. J Biol Chem 1999; 274:29677-82. [PMID: 10514438 DOI: 10.1074/jbc.274.42.29677] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The p53 tumor suppressor protein regulates the transcription of regulatory genes involved in cell cycle arrest and apoptosis. We have reported previously that inducible expression of the p53 gene leads to the cell cycle arrest both at G(1) and G(2)/M in association with induction of p21 and reduction of mitotic cyclins (cyclin A and B) and cdc2 mRNA. In this study, we investigated the mechanism by which p53 regulates transcription of the cdc2 gene. Transient transfection analysis showed that wild type p53 represses whereas various dominant negative mutants of p53 increase cdc2 transcription. The cdc2 promoter activity is not repressed in cells transfected with a transactivation mutant, p53(22/23). An adenovirus oncoprotein, E1B-55K inhibits the p53-mediated repression of the cdc2 promoter, while E1B-19K does not. Since the cdc2 promoter does not contain a TATA sequence, we performed deletion and point mutation analyses and identified the inverted CCAAT sequence located at -76 as a cis-acting element for the p53-mediated regulation. We found that a specific DNA-protein complex is formed at the CCAAT sequence and that this complex contains the NF-Y transcription factor. Consistently, a dominant negative mutant of the NF-YA subunit, NF-YAm29, decreases the cdc2 promoter, and p53 does not further decrease the promoter activity in the presence of NF-YAm29. These results suggest that p53 negatively regulates cdc2 transcription and that the NF-Y transcription factor is required for the p53-mediated regulation.
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Odim JN, Laks H, Drinkwater DC, George BL, Yun J, Salem M, Allada V. Staged surgical approach to neonates with aortic obstruction and single-ventricle physiology. Ann Thorac Surg 1999; 68:962-7; discussion 968. [PMID: 10509992 DOI: 10.1016/s0003-4975(99)00792-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND The surgical management of neonatal systemic outflow obstruction and complex single ventricle pathology is variable. METHODS In 15 neonates (12 boys and 3 girls) with complex forms of single-ventricle pathology and aortic coarctation or interruption, an initial strategy of banding the pulmonary artery and repair of the obstruction from a left thoracotomy was undertaken. RESULTS The median age at operation was 6 days (range 2 to 33 days) and the median weight was 3.3 kg (range 2 to 4.6 kg). There were no early deaths and one late death after the initial surgical palliation. Of the 14 survivors, 8 have undergone a bidirectional cavopulmonary anastomosis. The median age for bidirectional Glenn was 9.75 months (range 3.5 to 26 months). Seven infants have required Damus-Kaye-Stansel reconstruction for subaortic obstruction (one early death). The median age of the Damus-Kaye-Stansel procedure was 4 months (range 3 weeks to 9 months). Thirteen of 15 patients (87%) are alive and 6 have proceeded to a Fontan operation (median follow-up 68 months). A single failing Fontan required takedown to bidirectional Glenn and central shunt. CONCLUSIONS Our experience suggests that this high-risk subgroup of neonates with aortic obstruction and single-ventricle pathophysiology is safely managed by initial pulmonary artery banding palliation and repair of aortic obstruction. This strategy, careful surveillance, and early relief of subaortic stenosis can maintain acceptable anatomy and hemodynamics for later bidirectional Glenn and Fontan procedures.
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184
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Pintucci G, Steinberg BM, Seghezzi G, Yun J, Apazidis A, Baumann FG, Grossi EA, Colvin SB, Mignatti P, Galloway AC. Mechanical endothelial damage results in basic fibroblast growth factor-mediated activation of extracellular signal-regulated kinases. Surgery 1999; 126:422-7. [PMID: 10455916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
BACKGROUND Endothelial damage, such as that associated with balloon angioplasty or preparation of veins for bypass grafts, results in intimal hyperplasia. Growth factors and cytokines that modulate endothelial cell functions through various intracellular signaling pathways mediate rapid endothelial repair, which may prevent or reduce restenosis. Here we investigated the effect of mechanical injury of endothelial cells on the mitogen-activated kinase signaling pathways, extracellular-signal-regulated kinases (ERKs), C-Jun N-terminal kinase (JNK/SAPK), and p38. METHODS Confluent human umbilical vein endothelial cells or bovine aortic endothelial cells were wounded with a razor blade; mitogen-activated kinase activation was monitored by immunoblotting with antibodies to active ERK, JNK/SAPK, or p38. RESULTS Wounding of human umbilical vein endothelial cell or bovine aortic endothelial cell monolayers resulted in rapid (5-minute) activation of ERK-1 and -2, which was abolished by monoclonal antibody to basic fibroblast growth factor (FGF-2). This antibody or an inhibitor of ERK activation, PD98059, also blocked endothelial cell migration after the wounding. Thus FGF-2-induced ERK activation mediates the endothelial response to wounding. CONCLUSIONS ERK-1 and -2 are activated by FGF-2 released from endothelial cells in response to injury. Therapeutic strategies aimed at reducing FGF-2-induced intimal hyperplasia should preserve ERK activation in endothelial cells while abolishing it in smooth muscle cells.
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Yamada M, Tomida A, Yun J, Cai B, Yoshikawa H, Taketani Y, Tsuruo T. Cellular sensitization to cisplatin and carboplatin with decreased removal of platinum-DNA adduct by glucose-regulated stress. Cancer Chemother Pharmacol 1999; 44:59-64. [PMID: 10367750 DOI: 10.1007/s002800050945] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
PURPOSE Stress conditions, such as glucose starvation and hypoxia, that induce glucose-regulated proteins (GRPs) in cells, are seen in most solid tumors. These conditions have been shown to cause cellular resistance to multiple anticancer drugs, such as etoposide, doxorubicin, and camptothecin. We examined the effect of the GRP-inducing conditions on cellular sensitivity to cisplatin and carboplatin, which are widely used drugs against solid tumors. METHODS We generated the GRP-inducing culture conditions by exposing cells to 2-deoxyglucose (2DG), calcium ionophore A23187 and tunicamycin, and examined cellular sensitivity to cisplatin and carboplatin under these conditions. We next measured platinum accumulation and DNA-bound platinum in 2DG-stressed cells after cisplatin exposure. RESULTS The GRP-inducing stress conditions led to cellular sensitization to cisplatin and carboplatin. This sensitization was reversible, as the cellular sensitivity returned to normal levels 12 h after removal of 2DG. Platinum accumulation and DNA-bound platinum that were found immediately after exposure to cisplatin for 1 h were slightly increased in 2DG-stressed cells as compared with nonstressed cells. After a drug-free recovery incubation of 8 h, the DNA-bound platinum in the nonstressed cells was reduced by 33% while the amount in the 2DG-stressed cells was sustained at the initial levels. CONCLUSIONS These results indicated that the decreased removal of platinum-DNA adducts was associated with increased sensitivity to cisplatin and carboplatin in the stressed cells. The sensitization of cancer cells under the GRP-inducing stress conditions would explain, in part, the clinical potency of platinum drugs against solid tumors.
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186
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Yun J, Fischbein M, Laks H, Fishbein M, Espejo M, Hemat F, Ardehali A. CHEMOKINES MIP-2 AND MCP-1/JE MEDIATE LEUKOCYTE RECRUIT AFTER REPERFUSION. Transplantation 1999. [DOI: 10.1097/00007890-199904150-00204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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187
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Grieb TW, Ring M, Brown E, Palmer C, Belle N, Donjerkovic D, Chang H, Yun J, Subramanian R, Forozan F, Guo Y, Vertes A, Winkles JA, Burgess WH. Primary structure of ovine fibroblast growth factor-1 deduced by protein and cDNA analysis. Biochem Biophys Res Commun 1998; 246:182-91. [PMID: 9600090 DOI: 10.1006/bbrc.1998.8597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The amino acid sequence of full-length ovine fibroblast growth factor-1 (FGF-1) was determined by a combination of protein and cDNA sequencing. FGF-1 cDNA analysis indicated that ovine kidney cells express mRNAs encoding both full-length FGF-1 and a truncated FGF-1 variant. An overall comparison of the ovine FGF-1 primary sequence to the eight species studied to date revealed a high degree of conservation, with ovine FGF-1 sharing 90 and 95% sequence identity with human FGF-1 and bovine FGF-1, respectively. Additionally, the FGF-1 proteins from the various species have conserved cysteine residues at positions 30 and 97 and contain acetylated amino-terminal alanine residues. Mass spectrometry analysis confirmed that the blocking group of ovine FGF-1 is also consistent with that of an acetyl-moiety. In contrast to the other FGF-1 proteins, the 154 residue primary sequence of ovine FGF-1 contains three unique amino acid differences: Arg9, Arg44, and Ile123. Ovine FGF-1, unlike human FGF-1, is a potent mitogenic factor for NIH 3T3 fibroblasts in the absence of heparin. In the presence of exogenous heparin, the mitogenic activity of ovine FGF-1 is potentiated slightly.
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Klei L, Yun J, Sapru A, Lynch J, Barbano D, Sears P, Galton D. Effects of milk somatic cell count on cottage cheese yield and quality. J Dairy Sci 1998; 81:1205-13. [PMID: 9621221 DOI: 10.3168/jds.s0022-0302(98)75680-2] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Eight Holstein cows in midlactation were selected for low milk somatic cell count (SCC) and the absence of the pathogens that cause mastitis. Milk collection and cottage cheese manufacture from low SCC milk were replicated on each of 4 d (control period). Each cow was infused with 1000 cfu of Streptococcus agalactiae. One week after infusion, milk from the same eight cows was collected and commingled. On each of 4 d, cottage cheese was made from milk with high SCC (treatment period). A mass-balance protocol, accounting for protein and total solids, was used to determine recoveries in whey, wash water, and uncreamed curd. Actual yields, yields adjusted for composition, and theoretical yields of uncreamed curd were calculated. Mean milk SCC for the periods with the low SCC (control) and the high SCC (treatment) were 83 x 10(3) and 872 x 10(3) cells/ml, respectively. The recovery of protein in the uncreamed curd was higher during the low SCC period than during the high SCC period (75.85% vs. 74.35%). High SCC and the associated higher proteolytic activity caused higher protein loss in the whey and wash water and more curd fines. The percentage of total solids recovery in uncreamed curd was higher for high SCC milk because the lactose content of the high SCC milk was 0.27% lower than that of the low SCC milk. The moisture content of the curd was higher for the high SCC milk (82.75% vs. 83.81%). Proteolysis during refrigerated storage was faster in cottage cheese made from high SCC milk. The yield efficiency of uncreamed curd, adjusted for composition based on 81% moisture, was 4.34% lower for the cottage cheese curd made from high SCC milk.
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Yun J. [Experimental studies on the fatigue resistance of fermented morel liquid]. WEI SHENG YAN JIU = JOURNAL OF HYGIENE RESEARCH 1997; 26:330-2. [PMID: 10325649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
The fatigue resistant effect of fermented morel liquid is studied in mice. The results show: fermented morel liquid can remarkably promote the reserve of glycogen in muscle and liver, raise the hemoglobin concentration, reduce the content of blood lactic acid, and greatly enhance the sporting endurance.
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190
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Wess J, Liu J, Blin N, Yun J, Lerche C, Kostenis E. Structural basis of receptor/G protein coupling selectivity studied with muscarinic receptors as model systems. Life Sci 1997; 60:1007-14. [PMID: 9121341 DOI: 10.1016/s0024-3205(97)00041-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Different muscarinic acetylcholine receptor subtypes were used as model systems to study the structural basis of receptor/G protein coupling selectivity. Extensive mutagenesis studies have previously led to the identification of single amino acids on the m3 muscarinic receptor protein (located in the second intracellular loop (i2) and at the N- and C-terminus of the third intracellular loop (i3)) that dictate selective recognition of Gq/11 proteins by this receptor subtype. Based on these results, we proposed a model of the intracellular m3 receptor surface in which the functionally critical residues project into the interior of the transmembrane receptor core. To identify specific regions on the G protein(s) that are contacted by these different, functionally critical receptor sites, we recently employed a novel experimental strategy involving the coexpression of hybrid m2/m3 muscarinic receptors with hybrid G alpha-subunits. Using this approach, we could demonstrate that the C-terminus of G protein alpha i/o-subunits is recognized by a short sequence element in the m2 muscarinic receptor ("VTIL") that is located at the junction between the sixth transmembrane domain (TM VI) and the i3 loop. We could show that this interaction is critically involved in determining coupling selectivity and triggering G protein activation. By using a similar strategy (coexpression of mutant muscarinic receptors with hybrid G alpha-subunits), other major receptor/G protein contact sites are currently being identified. These studies, complemented by biochemical and biophysical approaches, should eventually lead to a detailed structural model of the ligand-receptor-G protein complex.
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Abstract
The glucose-regulated stress response in mammalian cells is characterized by the increased synthesis of glucose-regulated proteins (GRPs). In this study, we found that GRP-inducing conditions in culture led to induction of resistance to the topoisomerase I-targeted drug camptothecin in human colon cancer HT-29 and ovarian cancer A2780 cells. The induction of camptothecin resistance was accompanied by decreased levels of camptothecin-induced cleavable complexes, as measured by a topoisomerase I band depletion assay. However, topoisomerase I protein levels were the same in both stressed and non-stressed cells. Furthermore, when isolated nuclei from stressed and non-stressed cells were treated with camptothecin, similar levels of cleavable complexes were obtained, suggesting that the activity of topoisomerase I did not change in stressed cells. In contrast, intracellular accumulation of camptothecin decreased in stressed cells. Our results indicate that stress-induced camptothecin resistance could be explained by reduced camptothecin accumulation, leading to decreased numbers of cleavable complexes, without quantitative or qualitative changes in topoisomerase I levels. In addition, cell cycle analysis revealed that the GRP-inducing treatments resulted in an accumulation of G1/G0-phase cells. As camptothecin shows an S-phase-specific cytotoxicity, the G1/G0-phase accumulation is another mechanism for camptothecin resistance. Since a glucose-regulated response is produced by hypoxia and nutrient deprivation that occur naturally in solid tumors, the resistance observed here can occur in some solid tumors and can be an obstacle to chemotherapy.
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Abstract
The glucose-regulated stress response in mammalian cells is characterized by the increased synthesis of glucose-regulated proteins (GRPs). In this study, we found that GRP-inducing conditions in culture led to induction of resistance to the topoisomerase I-targeted drug camptothecin in human colon cancer HT-29 and ovarian cancer A2780 cells. The induction of camptothecin resistance was accompanied by decreased levels of camptothecin-induced cleavable complexes, as measured by a topoisomerase I band depletion assay. However, topoisomerase I protein levels were the same in both stressed and non-stressed cells. Furthermore, when isolated nuclei from stressed and non-stressed cells were treated with camptothecin, similar levels of cleavable complexes were obtained, suggesting that the activity of topoisomerase I did not change in stressed cells. In contrast, intracellular accumulation of camptothecin decreased in stressed cells. Our results indicate that stress-induced camptothecin resistance could be explained by reduced camptothecin accumulation, leading to decreased numbers of cleavable complexes, without quantitative or qualitative changes in topoisomerase I levels. In addition, cell cycle analysis revealed that the GRP-inducing treatments resulted in an accumulation of G1/G0-phase cells. As camptothecin shows an S-phase-specific cytotoxicity, the G1/G0-phase accumulation is another mechanism for camptothecin resistance. Since a glucose-regulated response is produced by hypoxia and nutrient deprivation that occur naturally in solid tumors, the resistance observed here can occur in some solid tumors and can be an obstacle to chemotherapy.
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Schoneberg T, Yun J, Wenkert D, Wess J. Functional rescue of mutant V2 vasopressin receptors causing nephrogenic diabetes insipidus by a co-expressed receptor polypeptide. EMBO J 1996. [DOI: 10.1002/j.1460-2075.1996.tb00470.x] [Citation(s) in RCA: 107] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Schoneberg T, Yun J, Wenkert D, Wess J. Functional rescue of mutant V2 vasopressin receptors causing nephrogenic diabetes insipidus by a co-expressed receptor polypeptide. EMBO J 1996; 15:1283-91. [PMID: 8635461 PMCID: PMC450031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Inactivating mutations in distinct G protein-coupled receptors (GPCRs) are currently being identified as the cause of a steadily growing number of human diseases. Based on previous studies showing that GPCRs are assembled from multiple independently stable folding units, we speculated that such mutant receptors might be functionally rescued by 'supplying' individual folding domains that are lacking or misfolded in the mutant receptors, by using a co-expression strategy. To test the feasibility of this approach, a series of nine mutant V2 vasopressin receptors known to be responsible for X-linked nephrogenic diabetes insipidus were used as model systems. These mutant receptors contained nonsense, frameshift, deletion or missense mutations in the third intracellular loop or the last two transmembrane helices. Studies with transfected COS-7 cells showed that none of these mutant receptors, in contrast to the wild-type V2 receptor, was able to bind detectable amounts of the radioligand, [3H]arginine vasopressin, or to activate the G(S)/adenylyl cyclase system. Moreover, immunological studies demonstrated that the mutant receptors were not trafficked properly to the cell surface. However, several of the nine mutant receptors regained considerable functional activity upon co-expression with a C-terminal V2 receptor peptide spanning the sequence where the various mutations occur. In many cases, the restoration of receptor activity by the co-expressed receptor peptide was accompanied by a significant increase in cell surface receptor density. These findings may lead to the design of novel strategies in the treatment of diseases caused by inactivating mutations in distinct GPCRs.
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Wess J, Blin N, Yun J, Schöneberg T, Liu J. Molecular aspects of muscarinic receptor assembly and function. PROGRESS IN BRAIN RESEARCH 1996; 109:153-62. [PMID: 9009702 DOI: 10.1016/s0079-6123(08)62097-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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196
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Azeez A, Yun J, DeFife K, Colton E, Cahallan L, Verhoeven M, Cahallan P, Anderson JM, Hiltner A. In vitro monocyte adhesion and activation on modified FEP copolymer surfaces. J Appl Polym Sci 1995. [DOI: 10.1002/app.1995.070581012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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197
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Liu J, Conklin BR, Blin N, Yun J, Wess J. Identification of a receptor/G-protein contact site critical for signaling specificity and G-protein activation. Proc Natl Acad Sci U S A 1995; 92:11642-6. [PMID: 8524820 PMCID: PMC40458 DOI: 10.1073/pnas.92.25.11642] [Citation(s) in RCA: 167] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Each G protein-coupled receptor recognizes only a distinct subset of the many structurally closely related G proteins expressed within a cell. How this selectively is achieved at a molecular level is not well understood, particularly since no specific point-to-point contact sites between a receptor and its cognate G protein(s) have been identified. In this study, we demonstrate that a 4-aa epitope on the m2 muscarinic acetylcholine receptor, a prototypical Gi/o-coupled receptor, can specifically recognize the C-terminal 5 aa of alpha subunits of the Gi/o protein family. The m2 receptor residues involved in this interaction are predicted to be located on one side of an alpha-helical receptor region present at the junction between the third intracellular loop and the sixth transmembrane domain. Coexpression studies with hybrid m2/m3 muscarinic receptors and mutant G-protein alpha q subunits showed that the receptor/G-protein contact site identified in this study is essential for coupling specificity and G-protein activation.
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Blin N, Yun J, Wess J. Mapping of single amino acid residues required for selective activation of Gq/11 by the m3 muscarinic acetylcholine receptor. J Biol Chem 1995; 270:17741-8. [PMID: 7629074 DOI: 10.1074/jbc.270.30.17741] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Each G protein-coupled receptor can interact only with a limited number of the many structurally similar G proteins expressed within a cell. This study was undertaken to identify single amino acids required for selectively coupling the m3 muscarinic acetylcholine receptor to G proteins of the Gq/11 family. To this goal, distinct intracellular segments/amino acids of the m3 receptor were systematically substituted into the structurally closely related m2 muscarinic receptor, which couples to Gi/o proteins, not Gq/11 proteins. The resultant mutant receptors were expressed in COS-7 cells and studied for their ability to induce agonist-dependent stimulation of phosphatidylinositol hydrolysis, a response known to be mediated by G proteins of the Gq/11 class. Using this approach, we were able to identify four amino acids in the second intracellular loop and four amino acids at the C terminus of the third intracellular loop of the m3 muscarinic receptor that are essential for efficient Gq/11 activation. We could demonstrate that these amino acids, together with a short segment at the N terminus of the third intracellular loop, fully account for the G protein coupling preference of the m3 muscarinic receptor. Taken together, our data strongly suggest that only a limited number of amino acids, located on different intracellular regions, are required to determine the functional profile of a given G protein-coupled receptor.
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Chen WY, Chen NY, Yun J, Wight DC, Wang XZ, Wagner TE, Kopchick JJ. Amino acid residues in the third alpha-helix of growth hormone involved in growth promoting activity. Mol Endocrinol 1995; 9:292-302. [PMID: 7539887 DOI: 10.1210/mend.9.3.7539887] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The third amphiphilic alpha-helix of GH has been found to be an important motif in the biological activities of the molecule. To further characterize this growth-promoting domain, three bovine (b) GH analogs were designed: one contained a scrambled third amphiphilic alpha-helix (SAH); a second contained a scrambled hydrophilic region of the helix (SAP); and a third contained a scrambled hydrophobic region of the helix (SAB). Transgenic mice that expressed these mutated bGH genes were produced. SAH transgenic mice displayed a phenotype identical to nontransgenic littermates. SAB transgenic mice grew slightly larger than nontransgenic littermates but remained smaller than bGH transgenic mice. On the other hand, SAP transgenic mice exhibited a dwarf phenotype. We subsequently generated individual amino acid substitutions in the hydrophilic region of the helix. The results from the growth rates of corresponding transgenic mice demonstrated that most bGH analogs with individual amino acid substitution within the third alpha-helix retained wild type-like growth-promoting activity except those with alterations at positions 115, 119, 122, and 123. Together these residues are predicted to form a cleft in the helix. To further substantiate the importance of the cleft, we deleted Gly 119 (delta 119). This resulting bGH analog was inactive in vivo as well as in in vitro assays. These results indicated that the primary structure of the third alpha-helix is critical for GH's growth-promoting activity and Gly 119 is a crucial amino acid in this region. Three adjacent amino acids, Asp 115, Ala 122, and Leu 123, also contribute to the growth-enhancing ability of the molecule.
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Risma KA, Clay CM, Nett TM, Wagner T, Yun J, Nilson JH. Targeted overexpression of luteinizing hormone in transgenic mice leads to infertility, polycystic ovaries, and ovarian tumors. Proc Natl Acad Sci U S A 1995; 92:1322-6. [PMID: 7877975 PMCID: PMC42511 DOI: 10.1073/pnas.92.5.1322] [Citation(s) in RCA: 226] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Hypersecretion of luteinizing hormone (LH) is implicated in infertility and miscarriages in women. A lack of animal models has limited progress in determining the mechanisms of LH toxicity. We have recently generated transgenic mice expressing a chimeric LH beta subunit (LH beta) in gonadotropes. The LH beta chimera contains the C-terminal peptide of the human chorionic gonadotropin beta subunit. Addition of this peptide to bovine LH beta resulted in a hormone with a longer half-life. Furthermore, targeted expression of the LH beta chimera led to elevated LH levels and infertility in female transgenics. These mice ovulated infrequently, maintained a prolonged luteal phase, and developed pathologic ovarian changes such as cyst formation, marked enlargement of ovaries, and granulosa cell tumors. Testosterone and estradiol levels were increased compared to nontransgenic littermates. An unusual extragonadal phenotype was also observed: transgenic females developed hydronephropathy and pyelonephritis. The pathology observed demonstrates a direct association between abnormal secretion of LH and infertility and underscores the utility of the transgenic model for studying how excess LH leads to cyst formation, ovarian tumorigenesis, and infertility.
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