[1] WASHINGTON UNIV, SCH MED, DEPT PEDIAT, ST LOUIS, MO 63110 USA
[2] HOSP SICK CHILDREN, DEPT HAEMATOL & ONCOL, LONDON WC1N 3JH, ENGLAND
[3] UNIV COLOGNE, DEPT PEDIAT, W-5000 COLOGNE 41, GERMANY
[4] GGK UNIV HOSP, DEPT PEDIAT & PEDIAT SURG, COPENHAGEN, DENMARK
[5] HOSP INFANTIL LA FE, UNIDAD ONCOL PEDIAT, VALENCIA, SPAIN
[6] CHILDRENS HOSP BIRMINGHAM, DEPT PEDIAT, BIRMINGHAM, AL USA
[7] UNIV ALABAMA, BIRMINGHAM, AL 35294 USA
[8] INST GIANNINA GASLINI, DEPT PEDIAT, GENOA, ITALY
[9] CHILDRENS HOSP PHILADELPHIA, DEPT PEDIAT, PHILADELPHIA, PA USA
[10] CTR LEON BERARD, DEPT PEDIAT, F-69373 LYON, FRANCE
[11] UNIV HOSP UPPSALA, DEPT PEDIAT, UPPSALA, SWEDEN
[12] UNIV TSUKUBA, DEPT PEDIAT SURG, TSUKUBA, JAPAN
[13] FRENCHAY HOSP, IMPERIAL CANC RES FUND, PAEDIAT & NEUROONCOL GRP, BRISTOL BS16 1LE, AVON, ENGLAND
[14] UNIV GIESSEN, DEPT PEDIAT, W-6300 GIESSEN, GERMANY
[15] ST JUDE CHILDRENS RES HOSP, DEPT HEMATOL ONCOL, MEMPHIS, TN 38101 USA
[16] UNIV NEWCASTLE UPON TYNE, SCH MED, DEPT CHILD HLTH, NEWCASTLE UPON TYNE NE1 7RU, TYNE & WEAR, ENGLAND
[17] UNIV OSLO, INST PATHOL, OSLO 3, NORWAY
[18] KYOTO PREFECTURAL UNIV MED, DEPT PEDIAT, KYOTO 602, JAPAN
[19] LOS ANGELES CHILDRENS HOSP, DEPT PEDIAT, LOS ANGELES, CA USA
[20] UNIV TOKYO, DEPT PEDIAT SURG, TOKYO 113, JAPAN
[21] EMMA KINDER ZIEKENHUIS, DEPT PEDIAT ONCOL, AMSTERDAM, NETHERLANDS