To identify and appraise the evidence for an association between laryngomalacia (LM) and acid reflux through a systematic review of the existing literature.
MEDLINE, EMBASE, the Cochrane Library, ...Google Scholar, and collected additional publications cited in bibliographies.
Literature search by both authors with structured criteria to select studies evaluated for systematic review. The Oxford Centre for Evidence-Based Medicine (CEBM) guidelines were applied to assess study quality of evidence.
Twenty-seven studies, representing 1295 neonates with LM, were included. Levels of evidence varied from CEBM level 2a (n = 1) to 4 (n = 23). Although reflux definitions were diverse, overall reflux prevalence in this group was 59% (pooled odds ratio OR of 4 controlled studies = 1.15, P = .67). Further evidence supporting an association between reflux and LM included the ubiquity of acid reflux using dual-probe pH monitoring in children with LM (2 studies; n = 84), the increased prevalence of reflux in severe as compared with mild LM (3 studies; n = 237; pooled OR = 9.86, P < .0001), case series and reports of LM improvement with antireflux therapy (6 studies; n = 275), and histological evidence of reflux-related laryngeal inflammation in children with LM (2 studies; n = 18).
The literature shows a coexistence between acid reflux and LM, but the evidence for a causal association is limited. In view of the widespread use of antireflux treatment in LM, a randomized controlled trial of antireflux medication vs placebo appears justified.
The prevention of middle turbinate lateralization, and middle meatal synechiae formation, is the key to maintain a patent ostiomeatal complex following endoscopic sino-nasal surgery (ESS). Different ...techniques have been described to prevent this undesirable outcome, however, most of them are invasive, expensive, uncomfortable and/or obstructive. We present our technique to modified silastic sheets to circumvent these problems and improve ventilation and drainage of sinuses after surgery. The aim of this paper is to present how this silastic sheeting can be easily customized to the shape of the ethmoid cavity after ESS, allowing for ventilation of the aerated sinonasal cavities and at the same time preventing problematic synechiae/scar formation. A practical and easy technique to customize silastic stents following ESS is presented. Silastic sheets could be easily customized of the ethmoid cavity after ESS providing an excellent alternative to reduce middle turbinate lateralization and synechiae formation.
Summary With modern anesthesia, aspiration is an exceedingly rare complication, and we have learned that a prolonged fast can result in serious adverse effects in critically ill patients. We discuss ...the no-fast protocol implemented at Vancouver General Hospital in 2007 for intubated, tube-fed adult patients who underwent elective open tracheotomy.
Surgical management of posterior glottic stenosis is challenging. The posterior glottis can be approached either through an open laryngofissure or endoscopically. The postcricoid mucosal advancement ...(PCMA) flap), first described by Montgomery (Montgomery, Arch Otolaryngol 98:170-175, 1973), is a reconstructive technique that can be combined with either of these approaches, enabling resection of posterior glottic scar while preserving or improving voice and swallowing function. This article will describe the open technique, its indications, and its potential complications.
With modern anesthesia, aspiration is an exceedingly rare complication, and we have learned that a prolonged fast can result in serious adverse effects in critically ill patients. We discuss the ...no-fast protocol implemented at Vancouver General Hospital in 2007 for intubated, tube-fed adult patients who underwent elective open tracheotomy.
It is generally assumed that stabilizing selection promoting a phenotypic optimum acts to shape variation in quantitative traits across individuals and species. Although gene expression represents an ...intensively studied molecular phenotype, the extent to which stabilizing selection limits divergence in gene expression remains contentious. In this study, we present a theoretical framework for the study of stabilizing and directional selection using data from between-species divergence of continuous traits. This framework, based upon Brownian motion, is analytically tractable and can be used in maximum-likelihood or Bayesian parameter estimation. We apply this model to gene-expression levels in 7 species of Drosophila, and find that gene-expression divergence is substantially curtailed by stabilizing selection. However, we estimate the selective effect, s, of gene-expression change to be very small, approximately equal to Ns for a change of one standard deviation, where N is the effective population size. These findings highlight the power of natural selection to shape phenotype, even when the fitness effects of mutations are in the nearly neutral range.
Simple models of molecular evolution assume that sequences evolve by a Poisson process in which nucleotide or amino acid substitutions occur as rare independent events. In these models, the expected ...ratio of the variance to the mean of substitution counts equals 1, and substitution processes with a ratio greater than 1 are called overdispersed. Comparing the genomes of 10 closely related species of Drosophila, we extend earlier evidence for overdispersion in amino acid replacements as well as in four-fold synonymous substitutions. The observed deviation from the Poisson expectation can be described as a linear function of the rate at which substitutions occur on a phylogeny, which implies that deviations from the Poisson expectation arise from gene-specific temporal variation in substitution rates. Amino acid sequences show greater temporal variation in substitution rates than do four-fold synonymous sequences. Our findings provide a general phenomenological framework for understanding overdispersion in the molecular clock. Also, the presence of substantial variation in gene-specific substitution rates has broad implications for work in phylogeny reconstruction and evolutionary rate estimation.
PDF
