Volumen 23, Número 4. Julio - Agosto 2002

EDITORIAL
207 Understanding the sexual behaviour of adolescents
Dr. Oscar Sánchez Guerrero

ORIGINAL ARTICLES
210 Comparison of three different criteria of pH monitoring for gastroesophageal reflux diagnosis in children under six months of age
Dr. Pedro Munguía Vanegas, Dra. Flora Zárate Mondragón, Dr. Norberto Mata Rivera, Dr. Roberto Cervantes Bustamante, Dr. Thomas Mason Cordero, Dr. Jaime Ramírez Mayans

213 Congenital choanal atresia. Report of four cases
Dr. Enrique Segovia Forero, Dra. Norma Torres Macedo, Dr. Héctor Aguirre Mariscal, Dra. María del Carmen Medrano Tinoco

218 Relation risk/benefit of the treatment with aminophyline in two age groups
Lic. Dalyla Alonso Rodríguez, MSC Lilian Dyce Gordon, MSC Ana J. Viamontes Romero, Dra. Ela Moreno Téllez, Dra. Eloisa Casas Morell, Lic. Maylen Díaz Martínez

223 Adolescents and their knowledge of AIDS
Dra. Cecilia Guerrero Soler, Dra. Odila Quiroz Viqueira, Dr. Deybis Sánchez Miranda, Dra. Ivonne Más Alvarez, Dr. David Rodríguez Bencomo

228 Undeveloped scrotum syndrome
Dr. Francisco Beltrán Brown, Dr. Fernando Villegas A., Dra. Clara Blanc G., Dr. Jaime Catalán L., Dr. Alejandro Bierzwinski K.

REVIEW ARTICLES
232 Etiology of type 2 diabetes mellitus in children: evidence supporting primary resistance to insulin
Dr. Raúl Calzada León, Dra. Nelly Altamirano Bustamante, Dra. María de la Luz Ruiz Reyes

238 Vascular access in pediatrics. Care and maintenance of vascular catheters (IV of V parts)
Dr. Eduardo Vázquez Gutiérrez, Dr. José Antonio Gutiérrez Ureña, Dr. Carlos Alberto Calderón Elvir, Dr. Juan Carlos Duarte Valencia, Dr. José Manuel Ruano Aguilar

ADOLESCENCE
242 Contraceptive options at court?
Dra. Raffaela Schiavon Ermani

PEDIATRIC CRITERIA
243 Consensus on probiotics, biotherapeutic agents in the management of diarrhea (2002)
Dr. Yvan Vandenplas, Dr. Jaime Ramírez Mayans, Dr. C. Castañeda Guillot

ABSTRACTS
250 XI Annual Forum of Scientific Research (4th part)

268 NEW BOOKS

270 BIBLIOGRAPHIC REVIEW

273 LIST OF ERRATA