Incidence of New-Onset Obstructive Sleep Apnea After Posterior Flap Pharyngoplasty in Children.

INTRODUCTION: Obstructive sleep apnea (OSA) is a well-recognized complication of velopharyngeal insufficiency (VPI) surgery, but studies assessing OSA by means of a respiratory polygraphy (PG) are scarce. The aim of the study was to evaluate the incidence of new-onset OSA after posterior flap pharyngoplasty (PFP). MATERIALS: The postoperative PG of children with VPI who had a normal preoperative PG were analyzed. RESULTS: Eighteen patients (mean age, 9.8 ± 4.8 years; Pierre Robin sequence [n = 5], isolated cleft palate [n = 7], 22q11 deletion [n = 3], and 3 other diagnoses) were included in the study. Mean delay between surgery and the postoperative PG was 11.5 ± 13.5 months. Two patients (11%) developed severe OSA after PFP. One patient with 22q11 deletion developed overt OSA symptoms immediately after surgery with an apnea-hypopnea index (AHI) of 39 events per hour, requiring continuous positive airway pressure (CPAP) therapy. Obstructive sleep apnea improved spontaneously after 10 months, with an AHI of 2 events/h after CPAP weaning. The second patient had a cleft palate associated with a fetal alcohol syndrome and developed OSA symptoms after surgery with an AHI of 18 events/h requiring CPAP therapy. He could be weaned from CPAP 6 months later after a complete section of the pharyngeal flap with an AHI of 6 events/h during spontaneous breathing. CONCLUSIONS: New-onset OSA after PFP in children with VPI who had a normal preoperative PG was uncommon (11%) in the present cohort.

Synthesis of conformationally locked versions of puromycin analogues.

Conformationally locked North and South versions of puromycin analogues built on a bicyclo[3.1.0]hexane pseudosugar template were synthesized. The final assembly of the products was accomplished by the Staudinger-Vilarrasa coupling of the corresponding North (2 and 3) and South (6 and 7) 3'-azidopurine carbanucleosides with the Fmoc-protected 1-hydroxybenzotriazole ester of 4-methoxy-L-tyrosine. North azides 2 and 3 were reported earlier. The 3'-azido intermediates 6 and 7 that are necessary for the synthesis of the South puromycin analogues are described herein for the first time.

Structural and functional prerequisites for ribosomal nascent peptide acceptors: attempts to decipher the nature of the ribosome's catalysis of peptide bond formation.

Aminoacyl ribonucleoside analogues that are capable of binding to the acceptor site of ribosomes and taking over the nascent peptide bear, if properly designed, the potential of antibiotic and cytostatic activity. Here we present a study on the intrinsic conformations of natural and synthetic peptide acceptors and the basicities of their peptide accepting amino groups. The conformations and thermodynamic parameters of several synthetic puromycin analogues have been elucidated through ab initio calculations as well as temperature and pH dependent (1)H NMR experiments. The intrinsic basicities of their peptide accepting amino groups were determined through (1)H NMR and compared to the effective basicities of the peptide accepting amino groups of aminoacyl transfer RNAs with the same amino acid side chains, as estimated from the pH dependent kinetics of mRNA programmed ribosomal peptidyl transfer.

Total synthesis of a xylo-Puromycin analog.

N(6)-bis-demethylated xylo-Puromycin analog 2 was synthesized in 56% over 6 steps from adenosine 3, involving a Mattocks bromo acetylation, a regio- and stereo-selective ribo-epoxide ring opening with sodium azide and an efficient Staudinger-Vilarrasa coupling reaction for which the conditions have been optimized.