1
|
Valencia RG, Mihailovska E, Winter L, Bauer K, Fischer I, Walko G, Jorgacevski J, Potokar M, Zorec R, Wiche G. Plectin dysfunction in neurons leads to tau accumulation on microtubules affecting neuritogenesis, organelle trafficking, pain sensitivity and memory. Neuropathol Appl Neurobiol 2021; 47:73-95. [PMID: 32484610 PMCID: PMC7891324 DOI: 10.1111/nan.12635] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 05/19/2020] [Indexed: 12/26/2022]
Abstract
AIMS Plectin, a universally expressed multi-functional cytolinker protein, is crucial for intermediate filament networking, including crosstalk with actomyosin and microtubules. In addition to its involvement in a number of diseases affecting skin, skeletal muscle, heart, and other stress-exposed tissues, indications for a neuropathological role of plectin have emerged. Having identified P1c as the major isoform expressed in neural tissues in previous studies, our aim for the present work was to investigate whether, and by which mechanism(s), the targeted deletion of this isoform affects neuritogenesis and proper nerve cell functioning. METHODS For ex vivo phenotyping, we used dorsal root ganglion and hippocampal neurons derived from isoform P1c-deficient and plectin-null mice, complemented by in vitro experiments using purified proteins and cell fractions. To assess the physiological significance of the phenotypic alterations observed in P1c-deficient neurons, P1c-deficient and wild-type littermate mice were subjected to standard behavioural tests. RESULTS We demonstrate that P1c affects axonal microtubule dynamics by isoform-specific interaction with tubulin. P1c deficiency in neurons leads to altered dynamics of microtubules and excessive association with tau protein, affecting neuritogenesis, neurite branching, growth cone morphology, and translocation and directionality of movement of vesicles and mitochondria. On the organismal level, we found P1c deficiency manifesting as impaired pain sensitivity, diminished learning capabilities and reduced long-term memory of mice. CONCLUSIONS Revealing a regulatory role of plectin scaffolds in microtubule-dependent nerve cell functions, our results have potential implications for cytoskeleton-related neuropathies.
Collapse
Affiliation(s)
- R. G. Valencia
- Max F. Perutz LaboratoriesDepartment of Biochemistry and Cell BiologyUniversity of ViennaViennaAustria
- Present address:
Department of ImmunologyUniversity Children’s Hospital ZurichZurichSwitzerland
| | - E. Mihailovska
- Max F. Perutz LaboratoriesDepartment of Biochemistry and Cell BiologyUniversity of ViennaViennaAustria
- Present address:
AFFiRiS AGViennaAustria
| | - L. Winter
- Max F. Perutz LaboratoriesDepartment of Biochemistry and Cell BiologyUniversity of ViennaViennaAustria
- Neuromuscular Research DepartmentCenter for Anatomy and Cell BiologyMedical University of ViennaViennaAustria
| | - K. Bauer
- Max F. Perutz LaboratoriesDepartment of Biochemistry and Cell BiologyUniversity of ViennaViennaAustria
| | - I. Fischer
- Max F. Perutz LaboratoriesDepartment of Biochemistry and Cell BiologyUniversity of ViennaViennaAustria
| | - G. Walko
- Max F. Perutz LaboratoriesDepartment of Biochemistry and Cell BiologyUniversity of ViennaViennaAustria
- Present address:
Department of Biology and BiochemistryUniversity of BathBathUK
| | - J. Jorgacevski
- Laboratory of Neuroendocrinology – Molecular Cell PhysiologyFaculty of MedicineInstitute of PathophysiologyUniversity of LjubljanaLjubljanaSlovenia
- Celica Biomedical SloveniaLjubljanaSlovenia
| | - M. Potokar
- Laboratory of Neuroendocrinology – Molecular Cell PhysiologyFaculty of MedicineInstitute of PathophysiologyUniversity of LjubljanaLjubljanaSlovenia
- Celica Biomedical SloveniaLjubljanaSlovenia
| | - R. Zorec
- Laboratory of Neuroendocrinology – Molecular Cell PhysiologyFaculty of MedicineInstitute of PathophysiologyUniversity of LjubljanaLjubljanaSlovenia
- Celica Biomedical SloveniaLjubljanaSlovenia
| | - G. Wiche
- Max F. Perutz LaboratoriesDepartment of Biochemistry and Cell BiologyUniversity of ViennaViennaAustria
| |
Collapse
|
2
|
Schlimme BS, Achenbach P, Ayerbe Gayoso CA, Bernauer JC, Böhm R, Bosnar D, Challand T, Distler MO, Doria L, Fellenberger F, Fonvieille H, Gómez Rodríguez M, Grabmayr P, Hehl T, Heil W, Kiselev D, Krimmer J, Makek M, Merkel H, Middleton DG, Müller U, Nungesser L, Ott BA, Pochodzalla J, Potokar M, Sánchez Majos S, Sargsian MM, Sick I, Sirca S, Weinriefer M, Wendel M, Yoon CJ. Measurement of the neutron electric to magnetic form factor ratio at Q2=1.58 GeV2 using the reaction 3He[over →](e[over →],e'n)pp. Phys Rev Lett 2013; 111:132504. [PMID: 24116774 DOI: 10.1103/physrevlett.111.132504] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Indexed: 06/02/2023]
Abstract
A measurement of beam helicity asymmetries in the reaction 3He[over →](e[over →],e'n)pp is performed at the Mainz Microtron in quasielastic kinematics to determine the electric to magnetic form factor ratio of the neutron GEn/GMn at a four-momentum transfer Q2=1.58 GeV2. Longitudinally polarized electrons are scattered on a highly polarized 3He gas target. The scattered electrons are detected with a high-resolution magnetic spectrometer, and the ejected neutrons are detected with a dedicated neutron detector composed of scintillator bars. To reduce systematic errors, data are taken for four different target polarization orientations allowing the determination of GEn/GMn from a double ratio. We find μnGEn/GMn=0.250±0.058(stat)±0.017(syst).
Collapse
Affiliation(s)
- B S Schlimme
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
3
|
Stenovec M, Milošević M, Petrušić V, Potokar M, Stević Z, Prebil M, Kreft M, Trkov S, Andjus PR, Zorec R. Amyotrophic lateral sclerosis immunoglobulins G enhance the mobility of Lysotracker-labelled vesicles in cultured rat astrocytes. Acta Physiol (Oxf) 2011; 203:457-71. [PMID: 21726417 DOI: 10.1111/j.1748-1716.2011.02337.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
AIM We examined the effect of purified immunoglobulins G (IgG) from patients with amyotrophic lateral sclerosis (ALS) on the mobility and exocytotic release from Lysotracker-stained vesicles in cultured rat astrocytes. METHODS Time-lapse confocal images were acquired, and vesicle mobility was analysed before and after the application of ALS IgG. The vesicle counts were obtained to assess cargo exocytosis from stained organelles. RESULTS At rest, when mobility was monitored for 2 min in bath with Ca(2+), two vesicle populations were discovered: (1) non-mobile vesicles (6.1%) with total track length (TL) < 1 μm, averaging at 0.33 ± 0.01 μm (n = 1305) and (2) mobile vesicles (93.9%) with TL > 1 μm, averaging at 3.03 ± 0.01 μm (n = 20,200). ALS IgG (0.1 mg mL(-1)) from 12 of 13 patients increased the TL of mobile vesicles by approx. 24% and maximal displacement (MD) by approx. 26% within 4 min, while the IgG from control group did not alter the vesicle mobility. The mobility enhancement by ALS IgG was reduced in extracellular solution devoid of Ca(2+), indicating that ALS IgG vesicle mobility enhancement involves changes in Ca(2+) homeostasis. To examine whether enhanced mobility relates to elevated Ca(2+) activity, cells were stimulated by 1 mm ATP, a cytosolic Ca(2+) increasing agent, in the presence (2 mm) and in the absence of extracellular Ca(2+). ATP stimulation triggered an increase in TL by approx. 7% and 12% and a decrease in MD by approx. 11% and 1%, within 4 min respectively. Interestingly, none of the stimuli triggered the release of vesicle cargo. CONCLUSION Amyotrophic lateral sclerosis-IgG-enhanced vesicle mobility in astrocytes engages changes in calcium homeostasis.
Collapse
Affiliation(s)
- M Stenovec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Medical Faculty, Institute of Pathophysiology, University of Ljubljana, Slovenia
| | | | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Bernauer JC, Achenbach P, Ayerbe Gayoso C, Böhm R, Bosnar D, Debenjak L, Distler MO, Doria L, Esser A, Fonvieille H, Friedrich JM, Friedrich J, Gómez Rodríguez de la Paz M, Makek M, Merkel H, Middleton DG, Müller U, Nungesser L, Pochodzalla J, Potokar M, Sánchez Majos S, Schlimme BS, Sirca S, Walcher T, Weinriefer M. High-precision determination of the electric and magnetic form factors of the proton. Phys Rev Lett 2010; 105:242001. [PMID: 21231520 DOI: 10.1103/physrevlett.105.242001] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Indexed: 05/30/2023]
Abstract
New precise results of a measurement of the elastic electron-proton scattering cross section performed at the Mainz Microtron MAMI are presented. About 1400 cross sections were measured with negative four-momentum transfers squared up to Q² = 1 (GeV/c)² with statistical errors below 0.2%. The electric and magnetic form factors of the proton were extracted by fits of a large variety of form factor models directly to the cross sections. The form factors show some features at the scale of the pion cloud. The charge and magnetic radii are determined to be <r²E>½ = 0.879(5)stat(4)syst(2)model(4)group fm and <r²M>½ = 0.777(13)stat(9)syst(5)model(2)group fm.
Collapse
Affiliation(s)
- J C Bernauer
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Middleton DG, Annand JRM, Antelo MA, Ayerbe C, Barneo P, Baumann D, Bermuth J, Bernauer J, Blok HP, Böhm R, Bosnar D, Ding M, Distler MO, Friedrich J, Llongo JG, Glazier DI, Golak J, Glöckle W, Grabmayr P, Hehl T, Heim J, Hesselink WHA, Jans E, Kamada H, Mañas GJ, Kohl M, Lapikás L, MacGregor IJD, Martin I, McGeorge JC, Merkel H, Merle P, Monstad K, Moschini F, Müller U, Nogga A, Pérez-Benito R, Pospischil T, Potokar M, Rosner G, Seimetz M, Skibiński R, de Vries H, Walcher T, Watts DP, Weinriefer M, Weiss M, Witała H, Zihlmann B. Investigation of the exclusive 3He(e,e' pn)1H reaction. Phys Rev Lett 2009; 103:152501. [PMID: 19905628 DOI: 10.1103/physrevlett.103.152501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Indexed: 05/28/2023]
Abstract
Cross sections for the 3He(e,e' pn)1H reaction were measured for the first time at energy transfers of 220 and 270 MeV for several momentum transfers ranging from 300 to 450 MeV/c. Cross sections are presented as a function of the momentum of the recoil proton and the momentum transfer. Continuum Faddeev calculations using the Argonne V18 and Bonn-B nucleon-nucleon potentials overestimate the measured cross sections by a factor 5 at low recoil proton momentum with the discrepancy becoming smaller at higher recoil proton momentum.
Collapse
Affiliation(s)
- D G Middleton
- Kepler Centre for Astro and Particle Physics, Physikalisches Institut, Universität Tübingen, D-72076 Tübingen, Germany.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Subedi R, Shneor R, Monaghan P, Anderson BD, Aniol K, Annand J, Arrington J, Benaoum H, Benmokhtar F, Boeglin W, Chen JP, Choi S, Cisbani E, Craver B, Frullani S, Garibaldi F, Gilad S, Gilman R, Glamazdin O, Hansen JO, Higinbotham DW, Holmstrom T, Ibrahim H, Igarashi R, de Jager CW, Jans E, Jiang X, Kaufman LJ, Kelleher A, Kolarkar A, Kumbartzki G, LeRose JJ, Lindgren R, Liyanage N, Margaziotis DJ, Markowitz P, Marrone S, Mazouz M, Meekins D, Michaels R, Moffit B, Perdrisat CF, Piasetzky E, Potokar M, Punjabi V, Qiang Y, Reinhold J, Ron G, Rosner G, Saha A, Sawatzky B, Shahinyan A, Sirca S, Slifer K, Solvignon P, Sulkosky V, Urciuoli GM, Voutier E, Watson JW, Weinstein LB, Wojtsekhowski B, Wood S, Zheng XC, Zhu L. Probing Cold Dense Nuclear Matter. Science 2008; 320:1476-8. [DOI: 10.1126/science.1156675] [Citation(s) in RCA: 310] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
|
7
|
Mazouz M, Camsonne A, Camacho CM, Ferdi C, Gavalian G, Kuchina E, Amarian M, Aniol KA, Beaumel M, Benaoum H, Bertin P, Brossard M, Chen JP, Chudakov E, Craver B, Cusanno F, de Jager CW, Deur A, Feuerbach R, Fieschi JM, Frullani S, Garçon M, Garibaldi F, Gayou O, Gilman R, Gomez J, Gueye P, Guichon PAM, Guillon B, Hansen O, Hayes D, Higinbotham D, Holmstrom T, Hyde CE, Ibrahim H, Igarashi R, Jiang X, Jo HS, Kaufman LJ, Kelleher A, Kolarkar A, Kumbartzki G, Laveissiere G, Lerose JJ, Lindgren R, Liyanage N, Lu HJ, Margaziotis DJ, Meziani ZE, McCormick K, Michaels R, Michel B, Moffit B, Monaghan P, Nanda S, Nelyubin V, Potokar M, Qiang Y, Ransome RD, Réal JS, Reitz B, Roblin Y, Roche J, Sabatié F, Saha A, Sirca S, Slifer K, Solvignon P, Subedi R, Sulkosky V, Ulmer PE, Voutier E, Wang K, Weinstein LB, Wojtsekhowski B, Zheng X, Zhu L. Deeply virtual compton scattering off the neutron. Phys Rev Lett 2007; 99:242501. [PMID: 18233443 DOI: 10.1103/physrevlett.99.242501] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Indexed: 05/25/2023]
Abstract
The present experiment exploits the interference between the deeply virtual Compton scattering (DVCS) and the Bethe-Heitler processes to extract the imaginary part of DVCS amplitudes on the neutron and on the deuteron from the helicity-dependent D(e,e'gamma)X cross section measured at Q2=1.9 GeV2 and xB=0.36. We extract a linear combination of generalized parton distributions (GPDs) particularly sensitive to E_{q}, the least constrained GPD. A model dependent constraint on the contribution of the up and down quarks to the nucleon spin is deduced.
Collapse
Affiliation(s)
- M Mazouz
- LPSC, Université Joseph Fourier, CNRS/IN2P3, INPG, F-38026 Grenoble, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Ron G, Glister J, Lee B, Allada K, Armstrong W, Arrington J, Beck A, Benmokhtar F, Berman BL, Boeglin W, Brash E, Camsonne A, Calarco J, Chen JP, Choi S, Chudakov E, Coman L, Craver B, Cusanno F, Dumas J, Dutta C, Feuerbach R, Freyberger A, Frullani S, Garibaldi F, Gilman R, Hansen O, Higinbotham DW, Holmstrom T, Hyde CE, Ibrahim H, Ilieva Y, de Jager CW, Jiang X, Jones MK, Kang H, Kelleher A, Khrosinkova E, Kuchina E, Kumbartzki G, LeRose JJ, Lindgren R, Markowitz P, May-Tal Beck S, McCullough E, Meekins D, Meziane M, Meziani ZE, Michaels R, Moffit B, Norum BE, Oh Y, Olson M, Paolone M, Paschke K, Perdrisat CF, Piasetzky E, Potokar M, Pomatsalyuk R, Pomerantz I, Puckett A, Punjabi V, Qian X, Qiang Y, Ransome R, Reyhan M, Roche J, Rousseau Y, Saha A, Sarty AJ, Sawatzky B, Schulte E, Shabestari M, Shahinyan A, Shneor R, Sirca S, Slifer K, Solvignon P, Song J, Sparks R, Subedi R, Strauch S, Urciuoli GM, Wang K, Wojtsekhowski B, Yan X, Yao H, Zhan X, Zhu X. Measurements of the proton elastic-form-factor ratio mu pG p E/G p M at low momentum transfer. Phys Rev Lett 2007; 99:202002. [PMID: 18233135 DOI: 10.1103/physrevlett.99.202002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Indexed: 05/25/2023]
Abstract
High-precision measurements of the proton elastic form-factor ratio, mu pG p E/G p M, have been made at four-momentum transfer, Q2, values between 0.2 and 0.5 GeV2. The new data, while consistent with previous results, clearly show a ratio less than unity and significant differences from the central values of several recent phenomenological fits. By combining the new form-factor ratio data with an existing cross-section measurement, one finds that in this Q2 range the deviation from unity is primarily due to G p E being smaller than expected.
Collapse
Affiliation(s)
- G Ron
- Tel Aviv University, Tel Aviv 69978, Israel
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Merkel H, Achenbach P, Ayerbe Gayoso C, Bernauer JC, Böhm R, Bosnar D, Cheymol B, Distler MO, Doria L, Fonvieille H, Friedrich J, Janssens P, Makek M, Müller U, Nungesser L, Pochodzalla J, Potokar M, Sánchez Majos S, Schlimme BS, Sirca S, Tiator L, Walcher T, Weinriefer M. Recoil polarization and beam-recoil double polarization measurement of eta electroproduction on the proton in the region of the S11(1535) resonance. Phys Rev Lett 2007; 99:132301. [PMID: 17930579 DOI: 10.1103/physrevlett.99.132301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2007] [Indexed: 05/25/2023]
Abstract
The beam-recoil double polarization P(x')(h) and P(z')(h) and the recoil polarization P(y') were measured for the first time for the p(e,e'p)eta reaction at a four-momentum transfer of Q(2) = 0.1 GeV(2)/c(2) and a center of mass production angle of theta = 120 degrees at the Mainz Microtron MAMI-C. With a center of mass energy range of 1500 MeV<W<1550 MeV the region of the S11(1535) and D13(1520) resonance was covered. The results are discussed in the framework of a phenomenological isobar model (Eta-MAID). While P(x')(h) and P(z')(h) are in good agreement with the model, P(y') shows a significant deviation, consistent with existing photoproduction data on the polarized-target asymmetry.
Collapse
Affiliation(s)
- H Merkel
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Shneor R, Monaghan P, Subedi R, Anderson BD, Aniol K, Annand J, Arrington J, Benaoum H, Benmokhtar F, Bertin P, Bertozzi W, Boeglin W, Chen JP, Choi S, Chudakov E, Cisbani E, Craver B, de Jager CW, Feuerbach RJ, Frullani S, Garibaldi F, Gayou O, Gilad S, Gilman R, Glamazdin O, Gomez J, Hansen JO, Higinbotham DW, Holmstrom T, Ibrahim H, Igarashi R, Jans E, Jiang X, Jiang Y, Kaufman L, Kelleher A, Kolarkar A, Kuchina E, Kumbartzki G, LeRose JJ, Lindgren R, Liyanage N, Margaziotis DJ, Markowitz P, Marrone S, Mazouz M, Meekins D, Michaels R, Moffit B, Nanda S, Perdrisat CF, Piasetzky E, Potokar M, Punjabi V, Qiang Y, Reinhold J, Reitz B, Ron G, Rosner G, Saha A, Sawatzky B, Shahinyan A, Sirca S, Slifer K, Solvignon P, Sulkosky V, Thompson N, Ulmer PE, Urciuoli GM, Voutier E, Wang K, Watson JW, Weinstein LB, Wojtsekhowski B, Wood S, Yao H, Zheng X, Zhu L. Investigation of proton-proton short-range correlations via the 12C(e,e'pp) reaction. Phys Rev Lett 2007; 99:072501. [PMID: 17930888 DOI: 10.1103/physrevlett.99.072501] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Indexed: 05/25/2023]
Abstract
We investigated simultaneously the 12C(e,e'p) and 12C(e,e'pp) reactions at Q2=2 (GeV/c)2, xB=1.2, and in an (e, e'p) missing-momentum range from 300 to 600 MeV/c. At these kinematics, with a missing momentum greater than the Fermi momentum of nucleons in a nucleus and far from the delta excitation, short-range nucleon-nucleon correlations are predicted to dominate the reaction. For (9.5+/-2)% of the 12C(e,e'p) events, a recoiling partner proton was observed back-to-back to the 12C(e,e'p) missing-momentum vector, an experimental signature of correlations.
Collapse
Affiliation(s)
- R Shneor
- Tel Aviv University, Tel Aviv 69978, Israel
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Acha A, Aniol KA, Armstrong DS, Arrington J, Averett T, Bailey SL, Barber J, Beck A, Benaoum H, Benesch J, Bertin PY, Bosted P, Butaru F, Burtin E, Cates GD, Chao YC, Chen JP, Chudakov E, Cisbani E, Craver B, Cusanno F, De Leo R, Decowski P, Deur A, Feuerbach RJ, Finn JM, Frullani S, Fuchs SA, Fuoti K, Gilman R, Glesener LE, Grimm K, Grames JM, Hansen JO, Hansknecht J, Higinbotham DW, Holmes R, Holmstrom T, Ibrahim H, de Jager CW, Jiang X, Katich J, Kaufman LJ, Kelleher A, King PM, Kolarkar A, Kowalski S, Kuchina E, Kumar KS, Lagamba L, LaViolette P, LeRose J, Lindgren RA, Lhuillier D, Liyanage N, Margaziotis DJ, Markowitz P, Meekins DG, Meziani ZE, Michaels R, Moffit B, Nanda S, Nelyubin V, Otis K, Paschke KD, Phillips SK, Poelker M, Pomatsalyuk R, Potokar M, Prok Y, Puckett A, Qian X, Qiang Y, Reitz B, Roche J, Saha A, Sawatzky B, Singh J, Slifer K, Sirca S, Snyder R, Solvignon P, Souder PA, Stutzman ML, Subedi R, Suleiman R, Sulkosky V, Tobias WA, Ulmer PE, Urciuoli GM, Wang K, Whitbeck A, Wilson R, Wojtsekhowski B, Yao H, Ye Y, Zhan X, Zheng X, Zhou S, Ziskin V. Precision measurements of the nucleon strange form factors at Q2 approximately 0.1 GeV2. Phys Rev Lett 2007; 98:032301. [PMID: 17358678 DOI: 10.1103/physrevlett.98.032301] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Indexed: 05/14/2023]
Abstract
We report new measurements of the parity-violating asymmetry A(PV) in elastic scattering of 3 GeV electrons off hydrogen and 4He targets with <theta(lab)> approximately 6.0 degrees . The 4He result is A(PV)=(+6.40+/-0.23(stat)+/-0.12(syst))x10(-6). The hydrogen result is A(PV)=(-1.58+/-0.12(stat)+/-0.04(syst))x10(-6). These results significantly improve constraints on the electric and magnetic strange form factors G(E)(s) and G(M)(s). We extract G(E)(s)=0.002+/-0.014+/-0.007 at <Q(2)>=0.077 GeV2, and G(E)(s)+0.09G(M)(s)=0.007+/-0.011+/-0.006 at <Q(2)>=0.109 GeV2, providing new limits on the role of strange quarks in the nucleon charge and magnetization distributions.
Collapse
Affiliation(s)
- A Acha
- Florida International University, Miami, Florida 33199, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Camacho CM, Camsonne A, Mazouz M, Ferdi C, Gavalian G, Kuchina E, Amarian M, Aniol KA, Beaumel M, Benaoum H, Bertin P, Brossard M, Chen JP, Chudakov E, Craver B, Cusanno F, de Jager CW, Deur A, Feuerbach R, Fieschi JM, Frullani S, Garçon M, Garibaldi F, Gayou O, Gilman R, Gomez J, Gueye P, Guichon PAM, Guillon B, Hansen O, Hayes D, Higinbotham D, Holmstrom T, Hyde-Wright CE, Ibrahim H, Igarashi R, Jiang X, Jo HS, Kaufman LJ, Kelleher A, Kolarkar A, Kumbartzki G, Laveissière G, Lerose JJ, Lindgren R, Liyanage N, Lu HJ, Margaziotis DJ, Meziani ZE, McCormick K, Michaels R, Michel B, Moffit B, Monaghan P, Nanda S, Nelyubin V, Potokar M, Qiang Y, Ransome RD, Réal JS, Reitz B, Roblin Y, Roche J, Sabatié F, Saha A, Sirca S, Slifer K, Solvignon P, Subedi R, Sulkosky V, Ulmer PE, Voutier E, Wang K, Weinstein LB, Wojtsekhowski B, Zheng X, Zhu L. Scaling tests of the cross section for deeply virtual Compton scattering. Phys Rev Lett 2006; 97:262002. [PMID: 17280421 DOI: 10.1103/physrevlett.97.262002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Indexed: 05/13/2023]
Abstract
We present the first measurements of the e[over -->]p-->epgamma cross section in the deeply virtual Compton scattering (DVCS) regime and the valence quark region. The Q(2) dependence (from 1.5 to 2.3 GeV(2)) of the helicity-dependent cross section indicates the twist-2 dominance of DVCS, proving that generalized parton distributions (GPDs) are accessible to experiment at moderate Q(2). The helicity-independent cross section is also measured at Q(2)=2.3 GeV(2). We present the first model-independent measurement of linear combinations of GPDs and GPD integrals up to the twist-3 approximation.
Collapse
|
13
|
Kelly JJ, Roché RE, Chai Z, Jones MK, Gayou O, Sarty AJ, Frullani S, Aniol K, Beise EJ, Benmokhtar F, Bertozzi W, Boeglin WU, Botto T, Brash EJ, Breuer H, Brown E, Burtin E, Calarco JR, Cavata C, Chang CC, Chant NS, Chen JP, Coman M, Crovelli D, De Leo R, Dieterich S, Escoffier S, Fissum KG, Garde V, Garibaldi F, Georgakopoulus S, Gilad S, Gilman R, Glashausser C, Hansen JO, Higinbotham DW, Hotta A, Huber GM, Ibrahim H, Iodice M, de Jager CW, Jiang X, Klimenko A, Kozlov A, Kumbartzki G, Kuss M, Lagamba L, Laveissière G, Lerose JJ, Lindgren RA, Liyanage N, Lolos GJ, Lourie RW, Margaziotis DJ, Marie F, Markowitz P, McAleer S, Meekins D, Michaels R, Milbrath BD, Mitchell J, Nappa J, Neyret D, Perdrisat CF, Potokar M, Punjabi VA, Pussieux T, Ransome RD, Roos PG, Rvachev M, Saha A, Sirca S, Suleiman R, Strauch S, Templon JA, Todor L, Ulmer PE, Urciuoli GM, Weinstein LB, Wijesooriya K, Wojtsekhowski B, Zheng X, Zhu L. Recoil polarization for delta excitation in pion electroproduction. Phys Rev Lett 2005; 95:102001. [PMID: 16196919 DOI: 10.1103/physrevlett.95.102001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2005] [Indexed: 05/04/2023]
Abstract
We measured angular distributions of recoil-polarization response functions for neutral pion electroproduction for W = 1.23 GeV at Q(2) = 1.0 (GeV/c)(2), obtaining 14 separated response functions plus 2 Rosenbluth combinations; of these, 12 have been observed for the first time. Dynamical models do not describe quantities governed by imaginary parts of interference products well, indicating the need for adjusting magnitudes and phases for nonresonant amplitudes. We performed a nearly model-independent multipole analysis and obtained values for Re (S(1+)/M(1+)) = -(6.84 +/- 0.15)% and Re (E(1+)/M(1+)) = -(2.91 +/- 0.19)% that are distinctly different from those from the traditional Legendre analysis based upon M1+ dominance and ll(pi) < or = 1 truncation.
Collapse
Affiliation(s)
- J J Kelly
- Department of Physics, University of Maryland, College Park, 20742, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Kozlov A, Sarty AJ, Aniol KA, Bartsch P, Baumann D, Bertozzi W, Bohinc K, Böhm R, Chen JP, Dale D, Dennis L, Derber S, Ding M, Distler MO, Dragovitsch P, Ewald I, Fissum KG, Friedrich J, Friedrich JM, Geiges R, Gilad S, Jennewein P, Kahrau M, Kohl M, Krygier KW, Liesenfeld A, Margaziotis DJ, Merkel H, Merle P, Müller U, Neuhausen R, Pospischil T, Potokar M, Riccardi G, Roché R, Rosner G, Rowntree D, Schmieden H, Sirca S, Templon JA, Thompson MN, Wagner A, Walcher T, Weis M, Zhao J, Zhou ZL, Golak J, Glöckle W, Witała H. Measurement of the exclusive 3He(e,e'p) reaction below the quasielastic peak. Phys Rev Lett 2004; 93:132301. [PMID: 15524710 DOI: 10.1103/physrevlett.93.132301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2002] [Revised: 12/16/2003] [Indexed: 05/24/2023]
Abstract
New, high-precision measurements of the 3He(e,e(')p) reaction using the A1 Collaboration spectrometers at the Mainz microtron MAMI are presented. These were performed in antiparallel kinematics at energy transfers below the quasielastic peak, and at a central momentum transfer of 685 MeV/c. Cross sections and distorted momentum distributions were extracted and compared to theoretical predictions and existing data. The longitudinal and transverse behavior of the cross section was also studied. Sizable differences in the cross-section behavior from theoretical predictions based on the plane wave impulse approximation were observed in both the two- and three-body breakup channels. Full Faddeev-type calculations account for some of the observed excess cross-section, but significant differences remain.
Collapse
Affiliation(s)
- A Kozlov
- Department of Physics, University of Regina, Regina, SK S4S0A2, Canada and School of Physics, The University of Melbourne, VIC 3010, Australia
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Kreft M, Milisav I, Potokar M, Zorec R. Automated high through-put colocalization analysis of multichannel confocal images. Comput Methods Programs Biomed 2004; 74:63-67. [PMID: 14992827 DOI: 10.1016/s0169-2607(03)00071-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2002] [Revised: 04/08/2003] [Accepted: 04/20/2003] [Indexed: 05/24/2023]
Abstract
The laser scanning confocal microscope (LSCM) generates images of multiple labelled fluorescent samples. Colocalization of fluorescent labels is frequently examined. Here we present an example where localization of fluorescent analogues of cloned protein were referenced to fluorescent antibodies directed against the proteins of cellular compartments. Colocalization is usually evaluated by visual inspection of signal overlap or by using commercially available software tools, but there are limited possibilities to automate the analysis of large amounts of data. We developed a simple tool using Matlab to automate the colocalization procedure and to exclude the biased estimations resulting from visual inspections of images. The script in Matlab language code automatically imports confocal images and converts them into arrays. The contrast of all images is uniformly set by linearly reassigning the values of pixel intensities to use the full 8-bit range (0-255). Images are binarized on several threshold levels. The area above a certain threshold level is summed for each channel of the image and for colocalized regions. As a result, count of pixels above several threshold levels in any number of images is saved in an ASCII file. In addition Pearson's r correlation coefficient is calculated for fluorescence intensities of both confocal channels. Using this approach quick quantitative analysis of colocalization of hundreds of images is possible. In addition, such automated procedure is not biased by the examiner's subject visualization.
Collapse
Affiliation(s)
- M Kreft
- Lab. Neuroendocrinology-Molecular Cell Physiology, Inst. Pathophysiology, Medical Faculty, Zaloska 4, 1000 Ljubljana and Celica Biomed. Sciences Center, Stegne 21, 1000 Ljubljana, Slovenia
| | | | | | | |
Collapse
|
16
|
Abstract
Caspase-9 is an apoptosis initiator protease activated as a response to the mitochondrial damage in the cytoplasmic complex apoptosome. By fluorescence labelling of proteins, confocal microscopy and subcellular fractionations we demonstrate that caspase-9 is in the cytoplasm of non-apoptotic pituitary cells. The activation of apoptosis with rotenone triggers the redistribution of caspase-9 to mitochondria. Experiments using the general caspase inhibitor z-VAD.fmk and the specific caspase-9 inhibitor z-LEHD.fmk show that the caspase-9 redistribution is a regulated process and requires the activity of a caspase other than the caspase-9. We propose that this spatial regulation is required to control the activity of caspase-9.
Collapse
Affiliation(s)
- M Potokar
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Medical Faculty Ljubljana, Zaloska 4, Slovenia
| | | | | | | | | |
Collapse
|
17
|
Bartsch P, Baumann D, Bermuth J, Böhm R, Bohinc K, Bosnar D, Ding M, Distler M, Drechsel D, Elsner D, Ewald I, Friedrich J, Friedrich JM, Grözinger S, Hedicke S, Jennewein P, Kahrau M, Kamalov SS, Klein F, Krygier KW, Liesenfeld A, Merkel H, Merle P, Müller U, Neuhausen R, Pospischil T, Potokar M, Rosner G, Schmieden H, Seimetz M, Süle A, Tiator L, Wagner A, Walcher T, Weis M. Measurement of the beam-helicity asymmetry in the p((-->)e,e'p)pi(0) reaction at the energy of the Delta(1232) resonance. Phys Rev Lett 2002; 88:142001. [PMID: 11955140 DOI: 10.1103/physrevlett.88.142001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2001] [Indexed: 05/23/2023]
Abstract
In a p((-->)e,e'p)pi(0) out-of-plane coincidence experiment at the three-spectrometer setup of the Mainz Microtron MAMI, the beam-helicity asymmetry has been precisely measured around the energy of the Delta(1232) resonance and Q(2) = 0.2(GeV/c)(2). The results are in disagreement with three up-to-date model calculations. This is interpreted as a lack of understanding of the nonresonant background, which in dynamical models is related to the pion cloud.
Collapse
Affiliation(s)
- P Bartsch
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Merkel H, Bartsch P, Baumann D, Bermuth J, Bernstein AM, Bohinc K, Böhm R, Clawiter N, Derber S, Ding M, Distler MO, Ewald I, Friedrich JM, Friedrich J, Jennewein P, Kahrau M, Kohl M, Krygier KW, Kuss M, Liesenfeld A, Merle P, Miskimen RA, Müller U, Neuhausen R, Pavan MM, Pospischil T, Potokar M, Rosner G, Schmieden H, Seimetz M, Sirca S, Wagner A, Walcher T, Weis M. Neutral pion threshold production at Q(2) = 0.05 GeV(2)/c(2) and chiral perturbation theory. Phys Rev Lett 2002; 88:012301. [PMID: 11800938 DOI: 10.1103/physrevlett.88.012301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2001] [Indexed: 05/23/2023]
Abstract
New data are presented on the p(e,e'p)pi(0) reaction at threshold at a four-momentum transfer of Q(2) = 0.05 GeV(2)/c(2). The data were taken with the three-spectrometer setup of the A1 Collaboration at the Mainz Microtron MAMI. The complete center of mass solid angle was covered up to a center of mass energy of 4 MeV above threshold. Combined with measurements at three different values of the virtual photon polarization epsilon, the structure functions sigma(T), sigma(L), sigma(TT), and sigma(TL) are determined. The results are compared with calculations in heavy baryon chiral perturbation theory and with a phenomenological model. The measured cross section is significantly smaller than both predictions.
Collapse
Affiliation(s)
- H Merkel
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Pospischil T, Bartsch P, Baumann D, Bermuth J, Böhm R, Bohinc K, Derber S, Ding M, Distler M, Drechsel D, Elsner D, Ewald I, Friedrich J, Friedrich JM, Geiges R, Hedicke S, Jennewein P, Kahrau M, Kamalov SS, Klein F, Krygier KW, Lac J, Liesenfeld A, McIntyre J, Merkel H, Merle P, Müller U, Neuhausen R, Potokar M, Ransome RD, Rohe D, Rosner G, Schmieden H, Seimetz M, Sirca S, Sick I, Süle A, Tiator L, Wagner A, Walcher T, Warren GA, Weis M. Measurement of the recoil polarization in the p(e-->, e'p-->)pi(0) reaction at the Delta(1232) resonance. Phys Rev Lett 2001; 86:2959-2962. [PMID: 11290082 DOI: 10.1103/physrevlett.86.2959] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2000] [Indexed: 05/23/2023]
Abstract
The recoil proton polarization has been measured in the p(e-->,e'p-->)pi(0) reaction in parallel kinematics around W = 1232 MeV, Q2 = 0.121 (GeV/c)2, and epsilon = 0.718 using the polarized cw electron beam of the Mainz Microtron. All three proton polarization components, Px/P(e) = (-11.4+/-1.3+/-1.4)%, P(y) = (-43.1+/-1.3+/-2.2)%, and P(z)/P(e) = (56.2+/-1.5+/-2.6)%, could be measured simultaneously. The Coulomb quadrupole to magnetic dipole ratio, CMR = (-6.4+/-0.7(stat)+/-0.8(syst))%, was determined from Px in the framework of the Mainz Unitary Isobar Model. The consistency among the reduced polarizations and the extraction of the ratio of longitudinal-to-transverse response is discussed.
Collapse
Affiliation(s)
- T Pospischil
- Institut für Kernphysik, Universität Mainz, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Abstract
2-Ethylhexyl stearate was investigated in an embryo-/foetotoxicity and teratogenicity study on rats according to OECD guidelines for the testing of chemicals (No. 414). Dose levels of 0 (arachidis oil), 100, 300 and 1000mg/kg body weight/day were administered by gavage. Dams tolerated the applied dose levels without any toxic effects. Pre- and post-implantation loss and mean numbers of resorptions were unaffected by treatment. All parameters were comparable with the animals of the control group. Skeletal and visceral investigations revealed no treatment-related malformations. For embryo-/foetotoxicity, teratogenicity and maternal toxicity a NOAEL of 1000mg/kg was deduced.
Collapse
Affiliation(s)
- W Aulmann
- Henkel KGaA, D-40191, Düsseldorf, Germany.
| | | | | | | | | | | |
Collapse
|
21
|
Abstract
For many years, test methods for the prospective identification of skin sensitizing chemicals have been widely available. However, although these techniques have permitted the identification of the great majority of skin sensitizers, their use in assessing the relative potency of a particular chemical as a human contact allergen has not been well described. A primary reason for this is the inherent difficulty of such an exercise. A complex phenomenon involving interactions between the vehicle, the allergen, the skin and its inflammatory responses takes place during the induction and elicitation of sensitization. All these factors can have a profound effect on the threshold values determined for a skin sensitizer. Consequently, whether the assessment is conducted in humans or in animal models, a threshold concentration is always a function of the method of measurement as much as the potency of the allergen. Although an exhaustive review has not been carried out, this paper considers the attempts that have been made to assess relative potency by the measurement of dose-response relationships and the determination of induction and elicitation thresholds in both animal models and in humans. The latter has special relevance for regulatory toxicology and this matter is given particular attention in this article. Finally, recommendations are made: (a) that threshold concentrations for skin sensitizers should be determined on a case by case basis in relation to the likely mode of skin contact; (b) where the data are used in comparisons of skin sensitization potency, then there should be standardization of the method used for the determinations.
Collapse
Affiliation(s)
- D A Basketter
- Unilever Environmental Safety Laboratory, Sharnbrook, Bedford, UK
| | | | | | | | | |
Collapse
|
22
|
Blomqvist KI, Boeglin WU, Böhm R, Distler M, Edelhoff R, Friedrich J, Geiges R, Kahrau M, Korn M, Kramer H, Krygier KW, Kunde V, Kuss M, Laget JM, Liesenfeld A, Merle K, Neuhausen R, Offermann EA, Pospischil T, Potokar M, Rangacharyulu C, Rokavec A, Richter A, Richter AW, Rosner G, Sauer P, Schardt S, Schrieder G, Suda T, Vodenik B, Wagner A, Walcher T, Wolf S. Forward-Angle 3He(e,e' pi +/-) Coincident Electroproduction and the Search for Delta 's in the Ground State of 3He. Phys Rev Lett 1996; 77:2396-2399. [PMID: 10061943 DOI: 10.1103/physrevlett.77.2396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
23
|
Potokar M. [Aluminum in deodorants]. Dtsch Med Wochenschr 1996; 121:777. [PMID: 8646997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- M Potokar
- Forschung Biologie/Produktsicherheit, Henkel KGaA, Düsseldorf
| |
Collapse
|
24
|
Fritsch JP, Emrich HJ, Grasmück A, Neuhausen R, Schardt S, Zimmermann N, Calarco JR, Potokar M. Isoscalar E2 strength in 16O from the (e,e' alpha ) reaction. Phys Rev Lett 1992; 68:1667-1670. [PMID: 10045190 DOI: 10.1103/physrevlett.68.1667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
25
|
Botham PA, Basketter DA, Maurer T, Mueller D, Potokar M, Bontinck WJ. Skin sensitization--a critical review of predictive test methods in animals and man. Food Chem Toxicol 1991; 29:275-86. [PMID: 2040490 DOI: 10.1016/0278-6915(91)90025-3] [Citation(s) in RCA: 97] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
With the exception of the Draize Test, the guinea-pig test methods currently accepted by regulatory authorities worldwide are well able to predict the potential of a material to cause skin sensitization. Nevertheless, (a) some methods are more sensitive than others (e.g. adjuvant tests are generally more sensitive than non-adjuvant tests); (b) methods cannot be sufficiently standardized to give full reproducibility of results between laboratories; and (c) most methods are based on subjective visual grading of skin reactions--difficulties thus arise when testing coloured or irritant materials. Laboratories must be able to show the sensitivity of the method(s) they use by demonstrating that positive reactions occur with mild/moderate contact allergens rather than the strong/extreme sensitizers currently recommended in certain guidelines, specifically in the EEC Test Method. The sensitivity of the adjuvant tests is such that it is possible to halve the minimum number of animals required by present regulatory guidelines without compromising the capacity of the tests to detect weak/mild sensitizers. A similar review has not yet been made for non-adjuvant tests. Alternative test methods, including some recently developed mouse models, offer several advantages, including more objective endpoints. These tests have not been extensively validated and this precludes their use at present for regulatory purposes other than to confirm the sensitization potential of a material. Two new test methods using mice, the Mouse Ear-swelling Test and the Local Lymph Node Assay, appear promising. They should undergo rigorous interlaboratory testing to determine their sensitivity and specificity. In vitro methods do not represent a viable alternative in the foreseeable future. An approach using quantitative structure-activity relationships is the most likely route to a non-animal model, but this will require considerable research, development and validation. Human sensitization tests have generally not been used for the classification of substances as non-sensitizers. This is because of an absence of internationally agreed test protocols, the lack of positive controls and because the methods for establishing the sensitivity of human tests are less developed than for animal tests. Nevertheless, for products for which direct human contact is intended, predictive tests in human volunteers can be considered. The EEC Directive for the Classification, Packaging and Labelling of Dangerous Substances provides a reasonable approach to the evaluation of skin sensitizers.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
Affiliation(s)
- P A Botham
- ICI plc, ECETOC, European Chemical Industry Ecology & Toxicology Centre, Brussels, Belgium
| | | | | | | | | | | |
Collapse
|
26
|
Potokar M, Holtmann W, Werner-Busse A. Effectiveness of Vitamin E Protecting against UV-Light — Comparative Testing of the Natural Tocopherols on the Skin of the Hairless Mouse. ACTA ACUST UNITED AC 1990. [DOI: 10.1002/lipi.19900921007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
27
|
Schlede E, Maurer T, Potokar M, Schmidt WM, Schulz KH, Roll R, Kayser D. A differentiated approach to testing skin sensitization. Proposal for a new test guideline skin sensitization. Arch Toxicol 1989; 63:81-4. [PMID: 2658921 DOI: 10.1007/bf00316428] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The present EEC and OECD Guidelines for testing skin sensitization have been reviewed in light of scientific evidence demonstrating that those methods which use Freund's Complete Adjuvant (FCA) are likely to be more accurate in predicting a probable skin-sensitizing effect of a new substance in humans than those methods not employing Freund's Complete Adjuvant. In this new test guideline, therefore, the primary testing of a substance should be carried out using one of the recommended Adjuvant methods. In special cases a non-adjuvant method may be performed in addition. Not all of the seven methods in the EEC Guideline or eight methods in the OECD Guideline have been included, but in a proposal for an updated test protocol two Adjuvant tests (Maximization test by Magnusson and Kligman and Optimization test by Maurer), and two non-Adjuvant tests (Open Epicutaneous test by Klecak and Buehler test) are suggested. The criteria for selecting these methods are based on the fact that they are well validated and widely used on a broad basis by the scientific community. Furthermore, it is considered appropriate to permit the use of a lower number of animals than presently recommended for the testing of skin sensitization. This is also in agreement with aspects of animal welfare.
Collapse
Affiliation(s)
- E Schlede
- Max von Pettenkofer-Institute of the Federal Health Office, Berlin, Federal Republic of Germany
| | | | | | | | | | | | | |
Collapse
|
28
|
Potokar M, Ramak A. Information on photonuclear transition matrix elements from measuring the emitted nucleon polarization in the reaction plane. Phys Rev C Nucl Phys 1986; 34:2338-2340. [PMID: 9953719 DOI: 10.1103/physrevc.34.2338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
|
29
|
Potokar M, Grundler OJ, Heusener A, Jung R, Mürmann P, Schöbel C, Suberg H, Zechel HJ. Studies on the design of animal tests for the corrosiveness of industrial chemicals. Food Chem Toxicol 1985; 23:615-7. [PMID: 4040107 DOI: 10.1016/0278-6915(85)90188-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Using a defined method for the determination of irritant and corrosive effects, the effects of varying the exposure time and the extent of occlusion were investigated and compared in rabbit skin experiments (by occlusive and semi-occlusive methods, each at exposure times of 1 hr and 4 hr). The results for 23 substances demonstrate that exposure for 1 hr normally leads to a realistic assessment of corrosiveness, in agreement with those given in the EEC 'Dangerous Substances Directive' (67/548/EEC; Off. J. Europ. Commun. 1967, 196, 1). With several substances, the 4-hr exposure leads to corrosive effects that do not occur under practical conditions. Moreover, a 4-hr exposure does not lead to a realistic hazard assessment in every case; some substances exhibit a corrosive effect in this test but are not classified as "corrosive" in the EEC Guideline Annex I, no. 1.1. Results using the semi-occlusive method did not usually differ from those obtained with the occlusive method. In general, the semi-occlusive method can be used, and in the case of volatile substances it is strongly advocated.
Collapse
|
30
|
Reitsma PH, Bijvoet OL, Potokar M, van der Wee-Pals LJ, van Wijk-van Lennep MM. Apposition and resorption of bone during oral treatment with (3-amino-1-hydroxypropylidene)-1,1-bisphosphonate (APD). Calcif Tissue Int 1983; 35:357-61. [PMID: 6871766 DOI: 10.1007/bf02405058] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The effects of 1.5-2 years oral administration of disodium (3-amino-1-hydroxypropylidene)-1,1-bisphosphonate (APD) on bone metabolism were studied in male and female rats. APD was mixed in the food at levels of 500, 2,000 and 10,000 ppm. A dose-dependent increase in metaphyseal bone was found, indicative of continued inhibition of bone and cartilage resorption. APD did not affect mineralization of bone and cartilage, primary bone formation, or periosteal apposition. A short-term metabolic balance study was performed to compare the effects of oral with subcutaneous APD. Absorption of APD was in the order of 0.2%. Oral APD increased absorption of phosphate, probably by complexation of calcium with APD. The excess absorbed phosphate increased phosphaturia and decreased urinary calcium.
Collapse
|
31
|
Gloxhuber C, Potokar M, Pittermann W, Wallat S, Bartnik F, Reuter H, Braig S. Zeolithe A--A phosphate substitute for detergents: toxicological investigation. Food Chem Toxicol 1983; 21:209-20. [PMID: 6299912 DOI: 10.1016/0278-6915(83)90238-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Tests on Zeolithe A, a sodium aluminium silicate developed as a substitute for phosphates in detergents, were designed to investigate the safety of exposure to the material, or to detergents containing it, either under industrial conditions encountered during manufacturing processes or as a consequence of domestic use. The test programme included oral studies (acute, subchronic and long-term carcinogenicity tests and absorption measurements), and dermal, ocular and inhalation studies on the silicate alone and on appropriate detergent formulations, as well as studies of possible silicogenic activity and metal-complexing potential and measurements of dust generation and particle-size distribution. These studies did not produce any evidence to suggest that levels of domestic and industrial exposure resulting from the projected use of Zeolithe A in detergents would present any hazard to health. Zeolithe A did not induce silicotic tissue reactions and when incorporated into detergent formulations did not increase the liberation of fine dusts.
Collapse
|
32
|
Abstract
Three new diphosphonic acids, i.e. compounds containing a P-C-P bond, have been investigated for their ability to inhibit the vitamin D-induced calcification of aortas and kidneys in rats. The compounds were applied orally in various doses. All of the compounds, which had previously been shown to effectively inhibit the in vitro crystallization of apatite, markedly decreased the amount of calcium deposited in aortas and kidneys. One of the new compounds was substantially more effective than ethane-1-hydroxy-1,1-diphosphonic acid (EHDP), which was used as a reference compound. Diphosphonic acids might be used therapeutically in man against soft tissue calcification.
Collapse
|
33
|
Potokar M, Greb W, Ippen H, Maibach HI, Schulz KH, Lorenz P, Gloxhuber C. Bronidox, ein neues Konservierungsmittel für die Kosmetik Eigenschaften und toxikologisch-dermatologische Prüfergebnisse. ACTA ACUST UNITED AC 1976. [DOI: 10.1002/lipi.19760780703] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
34
|
Gloxhuber C, Potokar M, Braig S, van Raay HG, Schwarz G. Untersuchungen über das Vorkommen eines sensibilisierenden Bestandteils in einem technischen Alkyläthersulfat. ACTA ACUST UNITED AC 1974. [DOI: 10.1002/lipi.19740760307] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
35
|
|