Parameters of donor-recipient size mismatch and survival after bilateral lung transplantation.

Background: The purpose of this study was to investigate the relationship between donor-recipient height, gender and predicted estimates of total lung capacity (pTLC) mismatches and post-transplant survival.

Methods: The lung transplant databases at three programs were reviewed. The pTLC ratios (donor pTLC/recipient pTLC) and height ratios (donor height/recipient height) were calculated retrospectively.

Lung size mismatch in bilateral lung transplantation is associated with allograft function and bronchiolitis obliterans syndrome.

Background: Size mismatch between donor lungs and a recipient thorax could affect the major determinants of maximal expiratory airflow: airway resistance, propensity of airways to collapse, and lung elastic recoil.

Methods: A retrospective review of 159 adults who received bilateral lung transplants was performed. The predicted total lung capacity (pTLC) for donors and recipients was calculated based on sex and height.

Supranormal expiratory airflow after bilateral lung transplantation is associated with improved survival.

Rationale: flow volume loops (FVL) in some bilateral lung transplant (BLT) and heart-lung transplant (HLT) patients suggest variable extrathoracic obstruction in the absence of identifiable causes. These FVLs usually have supranormal expiratory and normal inspiratory flow rates (SUPRA pattern).

Objectives: characterize the relationship of the SUPRA pattern to predicted donor and recipient lung volumes, airway size, and survival.

Perception of airflow obstruction in patients hospitalized for acute asthma.

Background: Little is known about the perception of airflow obstruction in patients hospitalized for acute asthma.

Objectives: To evaluate patient perception of airflow obstruction at hospital discharge and at a 2-week follow-up visit and to determine whether symptom control and/or severity of airflow obstruction identified patients at risk for acute asthma after discharge.

Methods: In a prospective cohort study of inner-city adults hospitalized for acute asthma from April 1, 2001, through October 31, 2002, symptom control (Asthma Control Questionnaire) and airflow obstruction (forced expiratory volume in 1 second [FEV1] percentage predicted) were evaluated at discharge and 2 weeks after discharge.

The structural basis of airways hyperresponsiveness in asthma.

We hypothesized that structural airway remodeling contributes to airways hyperresponsiveness (AHR) in asthma. Small, medium, and large airways were analyzed by computed tomography in 21 asthmatic volunteers under baseline conditions (FEV1 = 64% predicted) and after maximum response to albuterol (FEV1 = 76% predicted). The difference in pulmonary function between baseline and albuterol was an estimate of AHR to the baseline smooth muscle tone (BSMT).

Inhaled corticosteroids and the beneficial effect of deep inspiration in asthma.

Deep inspiration-induced bronchoprotection and bronchodilation are impaired in asthma. We evaluated the effect of inhaled glucocorticosteroids on these phenomena. Two groups of subjects with asthma, 9 with moderate/severe hyperresponsiveness to methacholine, and 12 with mild/borderline hyperresponsiveness to methacholine, received inhaled fluticasone (880 microg daily) for 12 weeks.

Decreased exhaled nitric oxide in pulmonary arterial hypertension: response to bosentan therapy.

Rationale: Decreased nitric oxide (NO) is considered an important pathogenetic mechanism in pulmonary arterial hypertension (PAH), but clear evidence is lacking.

Objectives: We used multiple techniques to assess endogenous NO in 10 patients with untreated PAH (8 idiopathic and 2 anorexigen-associated PAH) and 12 control subjects.

Methods: After a nitrite/nitrate-restricted diet, NO metabolites (NOx) were assayed in 24-hour urine collections and exhaled NO (FE(NO)) determined at multiple expiratory flows.

Effects of tidal volume and respiratory frequency on lung lymph flow.

Ventilation (V) increases lung lymph flow (Ql), but the separate effects of tidal volume (Vt) and frequency (f) and the role of V-induced changes in edema formation are poorly understood. An isolated, in situ sheep lung preparation was used to examine these effects. In eight sheep with f = 10 min(-1), results obtained during 30-min periods with Vt = 5 or 20 ml/kg were compared with values obtained during bracketed 30-min control periods (Vt = 12.

Role of nasal nitric oxide in the resolution of experimental rhinovirus infection.

Background: Human rhinovirus (HRV) infections are associated with exacerbations of asthma, chronic obstructive pulmonary disease, and sinusitis. Nitric oxide (NO) might play an important role in host defense through its potent antiviral properties. Previous studies have shown that HRV infection in human subjects increased nasal epithelial expression of type 2 nitric oxide synthase (NOS2), an isoform of the enzyme that produces NO.

Modeling pulmonary nitric oxide exchange.

Nitric oxide (NO) was first detected in the exhaled breath more than a decade ago and has since been investigated as a noninvasive means of assessing lung inflammation. Exhaled NO arises from the airway and alveolar compartments, and new analytical methods have been developed to characterize these sources. A simple two-compartment model can adequately represent many of the observed experimental observations of exhaled concentration, including the marked dependence on exhalation flow rate.

Absence of deep inspiration-induced bronchoprotection against inhaled allergen.

Deep inspiration-induced bronchoprotection appears to be a major mechanism through which airway obstruction by spasmogens is avoided. Loss of bronchoprotection is associated with airway hyper-responsiveness. Individuals with allergic rhinitis and no airway hyperresponsiveness develop obstruction after allergen inhalation.

Improvement in spirometry following lung volume reduction surgery: application of a physiologic model.

According to a previously published theoretical model of emphysema, the ratio of RV to TLC (RV/TLC) reflects the size mismatch between the hyperinflated lungs in the disease and the surrounding chest. The model suggests that RV/TLC is an important predictor of improvement in FVC and that increased FVC is an important determinant of increased FEV(1) after lung volume reduction surgery (LVRS). We tested these predictions in 13 patients undergoing LVRS, in whom we made detailed measurements of lung mechanics.