Exercise-induced laryngeal obstruction: Quality initiative to improve assessment and management.

INTRODUCTION: Exercise-induced laryngeal obstruction (EILO) affects 2-3% of the general population and 5.1% of elite athletes. Symptoms arise during high-intensity exercise and resolve at rest. EILO is often misdiagnosed as exercise-induced asthma as both conditions can present with dyspnea, chest tightness and cough. The purpose of this quality initiative was to identify patient characteristics that predict a higher likelihood of EILO, streamline referrals for exercise-endoscopy testing and avoid unnecessary medications. METHODS: A retrospective chart review included patients referred to a pediatric tertiary center between 2013 and 2018 for suspected EILO requesting exercise endoscopy. Data was collected from the patient chart and referral letters included age, sex, physical activity, medications, symptoms, and results of pulmonary and cardiac function tests. RESULTS: Between 2013 and 2018, 35 patients (9 males and 26 females, aged 5-18 years) were referred. Only 18 patients developed symptoms during an exercise endoscopy test. The majority were female (15/18), older than 10 years (18/18) and were involved in competitive sports (16/18). Stridor was the most common complaint among all patients referred (24/35) and many reported anxiety and high stress (15/35). The majority (63%) were previously treated with asthma medication. Pulmonary and cardiac function testing was not predictive of EILO. CONCLUSION: EILO is typically present in adolescent females involved in competitive sports. Anxiety and high stress was commonly noted. The majority were treated with asthma medication even though pulmonary function testing was normal. Recognition of this patient profile should improve timely access to appropriate diagnostic assessments, avoid unnecessary medical treatment, and promote a return to optimal athletic performance.

Long-term multicentre randomised controlled study of high frequency chest wall oscillation versus positive expiratory pressure mask in cystic fibrosis.

BACKGROUND: Positive expiratory pressure (PEP) is the most commonly used method of airway clearance (AC) in Canada for patients with cystic fibrosis (CF) whereas, in some countries, high frequency chest wall oscillation (HFCWO) is the preferred form of AC. There have been no long-term studies comparing the efficacy of HFCWO and PEP in the CF population. OBJECTIVES: To determine the long-term efficacy of HFCWO compared with PEP mask therapy in the treatment of CF as measured by the number of pulmonary exacerbations (PEs). METHODS: A randomised controlled study was performed in 12 CF centres in Canada. After a 2-month washout period, subjects were randomised to perform either HFCWO or PEP mask therapy for 1 year. RESULTS: 107 subjects were enrolled in the study; 51 were randomised to PEP and 56 to HFCWO. There were 19 dropouts within the study period, of which 16 occurred prior to or at the time of randomisation. There were significant differences between the groups in the mean number of PEs (1.14 for PEP vs 2.0 for HFCWO) and time to first PE (220 days for PEP vs 115 days for HFCWO, p=0.02). There was no significant difference in lung function, health-related quality of life scores or patient satisfaction scores between the two groups. PEP mask therapy required a shorter treatment time. CONCLUSIONS: The results of this study favour PEP and do not support the use of HFCWO as the primary form of AC in patients with CF. CLINICAL TRIAL REGISTRATION NUMBER: NCT00817180.

The role of the jasmonate response in plant susceptibility to diverse pathogens with a range of lifestyles.

Plants defend themselves against attack from insects and pathogens with various resistance strategies. The jasmonate and salicylate signaling pathways are two induced responses that protect plants against these attackers. Knowledge of the range of organisms that are affected by each response is important for understanding how plants coordinate their defenses against multiple attackers and the generality of effect of different resistance mechanisms. The jasmonate response is known to protect plants against a wide range of insect herbivores; in this study, we examined the role of the jasmonate response in susceptibility to eight pathogens with diverse lifestyles in the laboratory and field. Recent biochemical models suggest that the lifestyle of the pathogen (necrotroph versus biotroph) should predict whether the jasmonate response will be involved in resistance. We tested this by examining the susceptibility of wild-type (cv Castlemart with no known genes for resistance to the pathogens used) and jasmonate-deficient mutant tomato (Lycopersicon esculentum) plants (def1) and by employing rescue treatments of the mutant. Plant susceptibility to five of the eight pathogens we examined was reduced by the jasmonate response, including two bacteria (Pseudomonas syringae and Xanthomonas campestris), two fungi (Verticillium dahliae and Fusarium oxysporum f. sp. lycopersici), and an oomycete (Phytophthora infestans). Susceptibility to three fungi was unaffected (Cladosporium fulvum, Oidium neolycopersici, and Septoria lycopersici). Our results indicate that the jasmonate response reduces damage by a wide range of pathogens from different lifestyles, a result that contrasts with the emerging picture of diseases on Arabidopsis. Thus, the generality of jasmonate-based resistance of tomato challenges the view that ecologically distinct plant parasites are resisted via different mechanisms.