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THE PEDIATRIC CLINICS OF NORTH AMERICA Volume 47, Number 5

Editor: Carin Davis Production Editor: Heather L. Long0

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The Pediatric Clinics of North America (ISSN 0031-3955) is published bi-monthly by W.B. Saunders Company, Corporate and Editorial Offices: The Curtis Center, Independence Square West, Philadelphia, PA 19106-3399. Accounting and Circulation Offices: 6277 Sea Harbor Drive, Orlando, FL 328874300. Periodicals postage paid at Orlando, FL 32862, and additional mailing offices. Subscription price per year is $107.00 (US individuals), $160.00 (US institutions), $159.00 (foreign individuals), $196.00 (foreign institutions), $141.00 (Cana- dian individuals), and $196.00 (Canadian institutions). To receive student /resident rate, orders must be accompanied by name of affiliated institution, date of term, and the signaturr of program/residency coordinator on institution letterhead. Orders will be billed at indi- vidual rate until proof of status is received. Foreign air speed delivery is included in all Cfinics subscription prices. All prices are subject to change without notice. POSTMASTER Send address changes to W.B. Saunders Company, Periodicals Fulfillment, Orlando, FL 328874300. Customer Service 1-800454-2452 (US). From outside the US, call 1-407-39.5400.

The Pediatric Clinics of North America is also published in Spanish by McGraw-Hill Inter- americana Editores S.A., Mexico City, Mexico; in Portuguese by Reichmann and Affonso Editores, Rua Comandante Coelho 1085, CEP 21250, Rio de Janeiro, Brazil; and in Greek by Althayia SA, Athens, Greece.

The Pediatric Clinics of North America is covered in Index Medicus, Excerpta Medica, Current Contents, Current ContentslClinical Medicine, Science Citation Index, ASCA, ISIIBIOMED, and BIOSIS.

Printed in the United States of America.

October 2000 ISSN 0031-3955