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Background Individuals with COPD have increased sensitivity to traffic-related air pollution (TRAP) such as diesel exhaust (DE), but little is known about the acute effects of TRAP on exercise responses in COPD. Research question Does pre-exercise exposure to TRAP (DE300, PM2.5=300 μg/m3) have greater adverse effects on exercise endurance, exertional dyspnea, and cardiorespiratory responses to exercise in participants with mild-to-moderate COPD compared to former smokers with normal spirometry and healthy controls? Study design and Methods In this double-blind, randomized, placebo-controlled, crossover study, 11 healthy never-smokers, 9 ex-smokers without COPD and 9 ex-smokers with COPD were separately exposed to filtered air (FA) and DE300 for 2 hours separated by a minimum of 4 weeks. Participants performed symptom limited constant load cycling tests within 2.5 hours of exposure with detailed cardiorespiratory and exertional symptom measurements. Results There was a significant negative effect of TRAP on exercise endurance time in healthy controls (DE300 vs. FA: 10.2±8.2 vs. 12.9±9.5 min, respectively; p=0.03), but not in ex-smokers without COPD (10.1±6.9 vs. 12.2±8.0 min; respectively, p=0.57) or ex-smokers with COPD (9.8±6.4 vs. 8.4±6.6 min, respectively, p=0.31). Furthermore, significant increases in inspiratory duty cycle and absolute end-expiratory and end-inspiratory lung volumes were observed, and dyspnea ratings were elevated at select submaximal measurement times only in healthy controls. Interpretation Contrary to our hypothesis, it was the healthy controls rather than the ex-smokers with and without COPD that were negatively impacted by TRAP during exercise.

Background In patients with a history suggestive of asthma, diagnosis is usually confirmed by spirometry with bronchodilator response (BDR) or confirmatory methacholine challenge testing (MCT). Research Question We examined the proportion of participants with negative BDR testing who had a positive MCT (and its predictors) result and characteristics of MCT, including effects of controller medication tapering and temporal variability (and predictors of MCT result change), and concordance between MCT and pulmonologist asthma diagnosis. Study Design and Methods Adults with self-reported physician-diagnosed asthma were recruited by random-digit dialing across Canada. Subjects performed spirometry with BDR testing and returned for MCT if testing was nondiagnostic for asthma. Subjects on controllers underwent medication tapering with serial MCTs over 3 to 6 weeks. Subjects with a negative MCT (the provocative concentration of methacholine that results in a 20% drop in FEV1 [PC20] > 8 mg/mL) off medications were examined by a pulmonologist and had serial MCTs after 6 and 12 months. Results Of 500 subjects (50.5 ± 16.6 years old, 68.0% female) with a negative BDR test for asthma, 215 (43.0%) had a positive MCT. Subjects with prebronchodilator airflow limitation were more likely to have a positive MCT (OR, 1.90; 95% CI, 1.17-3.04). MCT converted from negative to positive, with medication tapering in 18 of 94 (19.1%) participants, and spontaneously over time in 25 of 165 (15.2%) participants. Of 231 subjects with negative MCT, 28 (12.1%) subsequently received an asthma diagnosis from a pulmonologist. Interpretation In subjects with a self-reported physician diagnosis of asthma, absence of bronchodilator reversibility had a negative predictive value of only 57% to exclude asthma. A finding of spirometric airflow limitation significantly increased chances of asthma. MCT results varied with medication taper and over time, and pulmonologists were sometimes prepared to give a clinical diagnosis of asthma despite negative MCT. Correspondingly, in patients for whom a high clinical suspicion of asthma exists, repeat testing appears to be warranted.

Objective The aim of this study was to identify risk factors for long-term adverse outcomes in children with asthma after visiting the emergency department (ED). Methods A prospective observational study was conducted at the ED of a pediatric tertiary hospital in Ontario, Canada. Patient outcomes (ie, acute asthma episodes and ED visits) were measured at baseline and at 1- and 6-months post-ED discharge. Time trends in outcomes were assessed using the generalized estimating equations method. Multiple conditional logistic regressions were used to model outcomes at 6 months and examine the impact of drug insurance coverage while adjusting for confounders. Results Of the 269 children recruited, 81.8% completed both follow-ups. ED use significantly reduced from 39.4% at baseline to 26.8% at 6 months (P < .001), whereas the level of acute asthma episodes remained unchanged. Children with drug insurance coverage were less likely to have acute asthma episodes (adjusted odds ratio [AOR] = 0.36; 95% CI, 0.15–0.85; P < .02) or repeat ED visits (AOR = 0.45; 95% CI, 0.20–0.99; P < .05) at 6 months. Other risk factors for adverse outcomes included previous adverse asthma events and certain asthma triggers (eg, cold/sinus infection). Washing bed linens in hot water weekly was protective against subsequent acute asthma episodes. Conclusions Our study demonstrated significant improvements in long-term outcomes in children seeking acute care for asthma in the ED. Future efforts remain in targeting the sustainability of improved outcomes beyond 6 months. Risk factors identified can help target vulnerable populations for proper interventions, which may include efforts to maximize insurance coverage for asthma medications and strategies to improve asthma self-management through patient and provider education.

In Canada the incidences of Fetal Alcohol Spectrum Disorder (FASD) is estimated to be in 1 in 100 live births caused by prenatal exposure to alcohol, the disorder is the leading cause of developmental and cognitive disabilities among Canadian children and its effects are life lasting. No research has attempted to describe the experience of living with FASD from the perspective of Canadian children.The main purpose of this study was to describe the children's experience of living with FASD.A qualitative method was used to examine the children's experiences. Twenty-two (22) children, aged 6 to 18 years, living in urban and rural communities across Canada participated in an unstructured in-depth interview. Data was analysed using Colaizzi's qualitative method.For all children in this study, living day-to-day with FASD meant feeling different. Within this construct knowing the disability; feeling alone-feeling supported, and overcoming the disability were dominant themes which emerged.Implications for practice and research have been described.Fetal Alcohol Spectrum Disorder, children's experience, qualitative research.

In various forms of shock, TRH is equivalent to naloxone in reversing the hypotension and improving the survival rate. The present findings indicate that in spontaneously hypertensive rats (SHR), TRH has another naloxone-like effect in antagonizing the antihypertensive response to clonidine and alpha-methyldopa. When given during the hypotensive response to alpha-methyldopa, both naloxone and TRH produce a pressor response. While this effect of naloxone is blocked by prazosin, the effect of TRH is not influenced by prazosin or hexamethonium but is inhibited by a vasopressin pressor antagonist. This suggests that the pressor response to naloxone is mediated by the sympathetic nervous system, whereas the similar action of TRH is independent of sympatho-adrenomedullary functions and it is mediated by vasopressin.

Buspirone has previously been demonstrated to be efficacious in the treatment of anxiety. This four-week double-blind parallel study compared buspirone to diazepam and placebo in the treatment of 119 outpatients diagnosed as having generalized anxiety disorder. After a seven-day placebo washout period, eligible patients were randomized to one of three treatment groups. Buspirone (5 mg) and diazepam (5 mg) were administered BID and individually titrated to an optimal therapeutic dose by the end of week two. Buspirone and diazepam were equally effective in reducing Hamilton Anxiety (HAM-A) total and psychic factor scores from baseline values. Buspirone alone was significantly better than plecebo in reducing the HAM-A somatic factor score. Sixty-seven percent of both active treatment groups who were classified as “ill” on the baseline global psychopathology rating scale achieved a “not ill” status by study end. There were no significant differences between treatment groups at endpoint on the 56-item Symptom Checklist self-rating scale. Buspirone was demonstrated to be as effective as diazepam in relieving anxiety in this outpatient sample.

The transplacental acquisition, disposition and biotransformation of diazepam (DZ) was investigated in the pregnant guinea pig at 65-67 days of gestation following the administration of single oral doses of 10 mg/kg body weight, the dams and fetuses being euthanized 60 min post-treatment. Tissues (blood plasma, liver, brain, perirenal fat and placenta) were removed for drug residue analysis. Nordiazepam (NDZ) was the only metabolite produced by guinea pigs in vivo. Residues of DZ and NDZ were found in fetal tissues, indicating that the placenta was not an effective barrier. The influence of cigarette smoke on in vitro DZ biotransformation was studied by exposing pregnant guinea pigs (55-57 days of gestation) to ambient air (control) or cigarette smoke thrice daily for 10 consecutive days. At term (day 67), the fetuses were delivered by caesarean section for the preparation of hepatic and placental microsomes to measure the metabolism of DZ. DZ was converted at a slow rate into NDZ by fetal hepatic and placental microsomes in vitro. Exposure to cigarette smoke had no effect on DZ metabolism by the dam liver or by the placenta but a 2-4-fold increase in NDZ formation was observed in fetal hepatic microsomes.