HUMN | Publications | Published | Mutation Research (1999)

Michael Fenech a , Stefano Bonassi b.... *, Julie Turner a , Cecilia Lando b ,
Marcello Ceppi b , Wushou Peter Chang c , Nina Holland d , Micheline Kirsch-Volders e ,
Errol Zeiger f , Maria Paola Bigatti g , Claudia Bolognesi h , Jia Cao i , Giuseppe De Luca j ,
Marina Di Giorgio k , Lynnette R. Ferguson l , Aleksandra Fucic m , Omar Garcia Lima n ,
Valeria V. Hadjidekova o , Patrizia Hrelia p , Alicja Jaworska q , Gordana Joksic r ,
A.P. Krishnaja s , Tung-Kwang Lee t , Antonietta Martelli u , Michael J. McKay v ,
Lucia Migliore w , Ekaterina Mirkova x , Wolfgang-Ulrich Müller y , Youichi Odagiri z ,
Thierry Orsiere a1 , Maria Rosaria Scarf`i a2 , Maria J. Silva a3 , Toshio Sofuni a4 ,
Jordi Suralles a5 , Giorgio Trenta a6 , Irena Vorobtsova a7 , Anne Vral a8 , Andrea Zijno a9

*Corresponding author
E-mail address: stefano.bonassi@istge.it (S. Bonassi)

Organizations

a CSIRO Health Sciences and Nutrition, P.O. Box 10041, Adelaide, SA 5000, Australia
b Department of Environmental Epidemiology, Istituto Nazionale per la Ricerca sul Cancro, L. go R. Benzi 10, I-16132 Genova, Italy
c Institute of Environmental Health Sciences, National Yang Ming University Medical School, 155 Section 2 Lih-non Street, 11200 Taipei,
Taiwan
d School of Public Health, University of California, 217 Warren, Berkeley, CA 94720-7360, USA
e Laboratory for Cell Genetics, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium
f Errol Zeiger Consulting, Chapel Hill, NC 27517, USA
g Dipartimento di Biologia Animale e dell’ Uomo, University of Turin, V. Accademia Albertina 17, 10123 Turin, Italy
h Toxicological Evaluation Unit, Istituto Nazionale per la Ricerca sul Cancro, L. go R. Benzi 10, 16132 Genova, Italy
i Molecular Toxicology Laboratory, Third Military Medical University, Chong Qing 400038, China
j ANPA, Via V. Brancati 48, 00144 Rome, Italy
k Laboratorio Dosimetria Biologica, Autoridad Regulatoria Nuclear, Av. del Libertador 8250, 1429 Capital Federal, Buenos Aires, Argentina
l Auckland Cancer Society Research Center, Private Bag 92019, Auckland 1000, New Zealand
m Institute for Medical Research end Occupational Health, 10000 Zagreb, Ksaverska C2, Croatia
n Centro de Proteccion e Higiene de las Radiaciones, Calle 20 No. 4109 e/41y47 Miramar, AP 6195 Habana 6, Cuba
o Laboratory Radiation Mutagenesis, National Center Radiobiology and Radiation Protection, Bul. Kl. Ochridski 132, Sofia 1756, Bulgaria
p Department of Pharmacology, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
q Norwegian Radiation Protection Authority, P.O. Box 55, 1332 Oesteraas, Norway
r Vinca Institute of Nuclear Sciences, Medical Protection Center, 300-110, P.O. Box 522, 11001 Belgrade, Yugoslavia
s Cell Biology Division, Bhabha Atomic Research Center, Mumbai 400 085, India
t Department of Radiation Oncology, Brody school of Medicine at ECU, Greenville, NC 27858, USA
u DIMI, V. le Benedetto XV 2, 16132 Genoa, Italy
v Divisions of Radiation Oncology and Research, Peter McCallum Cancer Institute, Smorgon Family Building, St. Andrews Place East
Melbourne, Melbourne, Vic. 3002, Australia
w Dipartimento di Scienze dell’Uomo e dell’Ambiente, University of Pisa, Via S. Giuseppe 22, 56126 Pisa, Italy
x National Center of Hygiene, Medical Ecology and Nutrition, 15 Boul. D. Nestorov, Sofia 1431, Bulgaria
y Institute fur Medizinische Strahlenbiologie, Universitatsklinikum Essen, Hufelandstrasse 55, D45122 Essen, Germany
z Division of Human and Health Sciences, Yamanashi Prefectural College of Nursing, 1-6-1 Ikeda, Kofu 400-0062, Japan
a 1 Laboratoire de Biogenotoxicologie et de Mutagenese Env., Faculte de Medicine, Universite de la Mediterranee,
27 Bld. Jean Moulin, F-13385 Marseille Cedex 05, France
a 2 CNR-IRECE, Via Diocleziano 328, 80124 Naples, Italy
a 3 Centro de Genetica Humana, Portugal National Institute of Health, Av. Padre Cruz, 1649-016 Lisboa, Portugal
a 4 Chromosome Research Center, Olympus Optical Co. Ltd., 2-3 Kuboyama-cho, Hachioji-shi, Tokyo 192-8512, Japan
a 5 Dpt de Genetica i de Microbiologia, Facultat de Ciencies, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
a 6 DOSIME Group, Occupational Medicine Service, National Institute of Nuclear Physic, Via E. Fermi 40, 00044 Frascati (Rome), Italy
a 7 Central Research Institute of Roentgenology and Radiology, 189646 Leningradskaya Str. 70/4, Pesochny-2, St. Petersburg, Russia
a 8 Department of Radiation Protection, Faculty of Medicine, Proeftuinstraat 86, B-9000 Ghent, Belgium
a 9 Laboratory of Comparative Toxicology and Ecotoxicology, ISS, V. le Regina Elena 229, 00161 Rome, Italy
Received 6 May 2002; received in revised form 29 August 2002; accepted 20 September 2002

(1) The full text may be downloaded in electronic format from one the link below:
www.sciencedirect.com

(3) Full text of this paper can be requested from Dr. Michael Fenech, CSIRO Human Nutrition, Gouger Street, P.O. Box 10041, Adelaide, SA 5000, Australia (E-mail: michael.fenech@hsn.csiro.au) or any other HUMN committee member (listed on the front page).

Abstract
One of the objectives of the HUman MicroNucleus (HUMN) project is to identify the methodological variables that have an important impact on micronucleus (MN) or micronucleated (MNed) cell frequencies measured in human lymphocytes using the cytokinesis-block micronucleus assay. In a previous study we had shown that the scoring criteria used were likely to be an important variable. To determine the extent of residual variation when laboratories scored cells from the same cultures using the same set of standard scoring criteria, an inter-laboratory slide-scoring exercise was performed among 34 laboratories from 21 countries with a total of 51 slide scorers involved. The results of this study show that even under these optimized conditions there is a great variation in the MN frequency or MNed cell frequency obtained by individual laboratories and scorers. All laboratories ranked correctly the MNed cell frequency in cells from cultures that were unirradiated, or exposed to 1 or 2 Gy of gamma rays. The study also estimated that the intra-scorer median coefficient of variation for duplicate MNed cell frequency scores is 29% for unexposed cultures and 14 and 11% for cells exposed to 1 and 2 Gy, respectively. These values can be used as a standard for quality or acceptability of data in future studies. Using a Poisson regression model it was estimated that radiation dose explained 67% of the variance, while staining method, cell sample, laboratory, and covariance explained 0.6, 0.3, 6.5, and 25.6% of the variance, respectively, leaving only 3.1% of the variance unexplained. As part of this exercise, nucleoplasmic bridges were also estimated by the laboratories; however, inexperience in the use of this biomarker of chromosome rearrangement was reflected in the much greater heterogeneity in the data and the unexplained variation estimated by the Poisson model. The results of these studies indicate clearly that even after standardizing culture and scoring conditions it will be necessary to calibrate scorers and laboratories if MN, MNed cell and nucleoplasmic bridge frequencies are to be reliably compared among laboratories and among populations.
© 2002 Elsevier Science B.V. All rights reserved.