Key points are not available for this paper at this time.
Accepted for publication July 2, 1997. Address for reprints: Dr. Henry F. Pabst, Department of Pediatrics, University of Alberta, 2C3 Walter Mackenzie Centre, Edmonton, Alberta, Canada T6G 2R7. Fax 403-492-7136. From the Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada.
Henry F. Pabst (Wed,) studied this question.