Chest
-
Asthma is a common chronic disease characterized by variable respiratory distress with underlying airway inflammation and airflow obstruction. The incidence of asthma has risen inexorably over the past 50 years, suggesting that environmental factors are important in its etiology. All inhaled environmental stimuli interact with the lung at the respiratory epithelium, and it is a testament to the effectiveness of the airway innate defenses that the majority of inhaled substances are cleared without the need to elicit an inflammatory response. ⋯ The potential of a susceptible epithelium and the underlying mesenchyme to create a microenvironment that enables deviation of immune and inflammatory responses to external stimuli may be crucial in the development and progression of asthma. In this review, we consider three important groups of environmental stimuli on the epithelium in asthma: oxidants, such as environmental pollution and acetaminophen; viruses, including rhinovirus; and agents that cause barrier disruption, such as house dust mite allergens. The pathology associated with each stimulus is considered, and potential future treatments arising from research on their effects are presented.
-
Comparative Study
Clinical impact of findings supporting an alternative diagnosis on computed tomography pulmonary angiography in patients with suspected pulmonary embolism.
CT pulmonary angiography (CTPA) is commonly used as the first imaging test in the diagnostic workup of patients with suspected pulmonary embolism (PE). Other CTPA findings may provide an alternative explanation for signs and symptoms in these patients, but the clinical impact is not clear. ⋯ In patients undergoing CTPA for suspected PE, findings supporting an alternative diagnosis were found in almost one-half of the patients. However, in only a few patients, the alternative diagnosis had therapeutic consequences. Hence, CTPA should principally be used to confirm or exclude PE in high-probability cases but not to establish an alternative diagnosis.