Biomedical subjects

Jean-François Cloutier

Publications and source records attributed to Jean-François Cloutier.

4 recordsLinked to original sources

PubMed2005

Subannular ventilation tubes: retrospective study.

OBJECTIVE: To evaluate the efficiency of a subannular tube insertion technique in a group of pediatric patients with adhesive otitis or severe atelectasis of the tympanic membrane. DESIGN: Retrospective nonrandomized case series. SETTING: Tertiary referral centre. MAIN OUTCOME MEASURES: The main outcomes of this study are tube duration according to the type of tube used, the complication rate, and the audiometric gain associated with this procedure. RESULTS: The study group consisted of 190 patients (316 tubes) aged between 3 and 19 years (average 9 years old) and operated on between 1993 and 1999 by four pediatric otolaryngologists. The average follow-up was 53 months. The tubes remained in place for an average of 21.8 months, with fluoroplastic tubes lasting 17.8 months and Goode T tubes lasting 23.8 months. When used in children between 5 and 9 years of age and in cases of adhesive otitis, Goode T tubes showed statistically significantly better results than fluoroplastic tubes. The complications of this technique were otorrhea (17.7%), perforation (7.9%), a plugged tube (7.0%), and cholesteatoma (1.6%). The 5- to 9-year-old group and the reintervention group of patients showed statistically higher complication rates compared with all other groups. Sixty-four patients (128 tubes) were eligible for audiogram analysis, which showed a gain of 13.4 dB (speech reception threshold). CONCLUSIONS: The technique of subannular tube insertion is a safe and effective method for long-term middle ear ventilation in cases of adhesive otitis or severely atelectatic tympanic membrane or for patients with pathology related to dysfunction of the eustachian tube. It offers an alternative to repeated short-term tube insertions for otitis media with effusion or recurrent acute otitis media.

Adolescent↗

PubMed2004

Differential requirements for semaphorin 3F and Slit-1 in axonal targeting, fasciculation, and segregation of olfactory sensory neuron projections.

The formation of precise stereotypic connections in sensory systems is critical for defining accurate internal representations of the external world; however, the molecular mechanisms underlying the formation of sensory maps are poorly understood. Here, we examine the roles of two structurally unrelated repulsive guidance cues, semaphorin 3F (Sema3F) and Slit-1, in olfactory sensory axon fasciculation, targeting, and segregation. Using sema3F-/- mice, we show that Sema3F is critical for vomeronasal sensory neuron axonal fasciculation and for segregation of these sensory afferents from the main olfactory system; however, Sema3F plays only a minor role in targeting of apical vomeronasal neuron axons to the anterior accessory olfactory bulb (AOB). In addition, we show that Sema3F is required for lamina-specific targeting of olfactory sensory axons within the main olfactory system. In contrast to Sema3F, Slit-1 is dispensable for fasciculation of basal vomeronasal neuron axons but is critical for targeting these axons to the posterior AOB. These results reveal discrete and complementary roles for secreted semaphorins and slits in axonal targeting, fasciculation, and segregation of olfactory sensory neuron projections.

Animals↗

PubMed2004

Evaluating the reproducibility of sinus lavages with a saline solution administered directly in the maxillary sinus of patients after endoscopic sinus surgery.

INTRODUCTION: Chronic sinusitis is recognized as having a strong inflammatory component, and failures of endoscopic sinus surgery (ESS) are frequently attributed to persistent inflammation. A test that would allow rhinologists to evaluate the inflammatory state of a patient's sinuses would be helpful to evaluate cases refractory to therapy, determine appropriate medical therapy, and monitor the response to therapy. OBJECTIVES: The goal of this preliminary research is to assess the optimal method of collection and the reproducibility and specificity of sinus lavages. METHOD: Twelve patients who had undergone ESS were recruited. They were divided into two groups according to the persistence of their symptoms and the recurrence of acute sinusitis after ESS. The subjects were seen twice. Three successive lavages were collected from each maxillary sinus and were analyzed by cell count. RESULTS: Intrasession cell counts were most reproducible (Spearman rank correlation .7 for eosinophils and .6 for neutrophils) for the second lavage. Intersession cell counts were highly reproducible for eosinophils (r = .7) for the second lavage. The two-tailed t-test did not reveal any statistically significant differences between the good and the poor outcome groups. CONCLUSION: Assessment of eosinophil cell counts on sinus lavage is a feasible and reproducible method to evaluate the inflammatory state of a patient's sinuses in patients who have undergone ESS.

Acute Disease↗

PubMed2003

Signaling at the growth cone: ligand-receptor complexes and the control of axon growth and guidance.

The guidance of axons during the establishment of the nervous system is mediated by a variety of extracellular cues that govern cytoskeletal dynamics in axonal growth cones. A large number of these guidance cues and their cell-surface receptors have now been identified, and the intracellular signaling pathways by which these cues induce cytoskeletal rearrangements are becoming defined. This review summarizes our current understanding of the major families of axon guidance cues and their receptors, with a particular emphasis on receptor signaling mechanisms. We also discuss recent advances in understanding receptor cross talk and how the activities of guidance cues and their receptors are modulated during neural development.

Animals↗