We assessed upper airway responses to acute and chronic inspiratory loading. In Experiment I, 11 healthy subjects underwent T(2)-weighted magnetic resonance imaging (MRI) of upper airway dilator muscles (genioglossus and geniohyoid) before and up to 10 min after a single bout of pressure threshold inspiratory muscle training (IMT) at 60% maximal inspiratory mouth pressure (MIP). T(2) values for...

Congenital central hypoventilation syndrome (CCHS) is the failure of the autonomic system to control adequate ventilation while asleep with preserved ventilatory response while awake. We report a case of a patient with CCHS who presented with intrathoracic and extrathoracic airway obstruction after tracheostomy tube decannulation and phrenic nerve pacer placement. Nocturnal polysomnography (NPS...

BACKGROUND The role of small airway obstruction in the clinical expression of asthma is incompletely understood. OBJECTIVE We tested the hypotheses that markers of small airway obstruction are associated with (i) increased asthma severity, (ii) impaired asthma control and quality of life and (iii) frequent exacerbations. METHODS Seventy-four adults with asthma and 18 healthy control subject...

Obesity has been associated with an increased prevalence of asthma and poorer control of this disease. However, the mechanisms by which obesity can influence airway function and make asthma more difficult to control remain uncertain. The physiological changes associated with obesity can contribute to respiratory symptoms and these should be differentiated from those caused by asthma. Obesity ca...

Understanding the mechanisms involved in respiratory tolerance to inhaled allergens could potentially result in improved therapies for asthma and allergic diseases. Airway hyperresponsiveness (AHR) is a major feature of allergic asthma, thus the aim of the current study was to investigate mechanisms underlying suppression of allergen-induced AHR during chronic allergen exposure. Adult BALB/c mi...

The aim of this study was to investigate the effects of reverse headgear (RH) on pharyngeal airway morphology in two groups of Class III patients with different vertical craniofacial features in comparison with an untreated Class III group. Seventeen subjects (9 males, 8 females; mean age 11.3 ± 0.98 years) with optimum vertical growth and 17 subjects (10 males, 7 females, mean age 11.5 ± 1.1 y...

RATIONALE Airway wall remodeling is an important aspect of asthma. It has proven difficult to assess quantitatively as it involves changes in several components of the airway wall. OBJECTIVE To develop a simple method for quantifying the overall severity of airway wall remodeling in asthmatic airways using fractal geometry. METHODS Negative-pressure silicone rubber casts of lungs were made ...

The bronchoconstricting and bronchodilating divisions of the autonomic nervous system control airway caliber of lungs. Parasympathetic hyperactivity in asthmatics eventuates in broncho-constriction. Sympathetic activity increases to combat this but fails to control bronchoconstriction due to negligible innervations of the airway smooth muscles although it causes vasoconstriction of blood vessel...

OBJECTIVE The aim of this study was to evaluate long-term changes in the pharyngeal airway dimensions after functional appliance treatment in adolescents with skeletal Class II malocclusions. METHODS Pharyngeal airway dimensions were compared between subjects with skeletal Class II malocclusions (n = 24; mean age: 11.6 ± 1.29 years) treated with a Class II bionator and age-matched control sub...

PURPOSE Allergic asthma is characterized by chronic airway inflammation and airway hyperresponsiveness driven by allergen-specific T helper (Th)2 cells. Mycobacterium bovis bacillus Calmette-Guérin (BCG) vaccination has been documented to suppress Th2 responses and allergic airway inflammation in animal models. Since interleukin (IL)-12 is capable of inhibiting Th2 responses, we sought to inves...