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Biomedical subjects

W H Northway

Publications and source records attributed to W H Northway.

At least 19 recordsLinked to original sources
PubMed2001

Spirometer-triggered high-resolution computed tomography and pulmonary function measurements during an acute exacerbation in patients with cystic fibrosis.

OBJECTIVE: To evaluate a high-resolution computed tomography (HRCT) scoring system, clinical parameters, and pulmonary function measurements in patients with cystic fibrosis (CF) before and after therapy for a pulmonary exacerbation. STUDY DESIGN: Patients (n = 17) were evaluated by spirometer-triggered HRCT imaging, clinical parameters, and pulmonary function tests (PFTs) before and after treatment. HRCT scans were reviewed by 3 radiologists using a modified Bhalla scoring system. RESULTS: Bronchiectasis, bronchial wall thickening, and air trapping were identified in all subjects on initial evaluation. The initial total HRCT score correlated significantly with the Brasfield score (r = -.91, P <.001) and several PFT measures. After treatment, there were improvements in the acute change clinical score (ACCS) (P <.001), most pulmonary function measurements, and total HRCT score (P <.05). Bronchiectasis, bronchial wall thickening, and air trapping did not significantly change. Mucus plugging subcomponent HRCT score, slow vital capacity (SVC), forced expiratory volume in 1 second (FEV(1)), and forced vital capacity (FVC) (percent predicted) and reversible and total HRCT scores were most sensitive to change by effect size analysis. CONCLUSIONS: Improvements occurred with treatment in total and reversible HRCT scores, PFTs, and ACCS. Total and reversible HRCT scores and percent predicted SVC, FEV1, and FVC were the most sensitive to change. The greatest change was seen in the mucus plugging subcomponent HRCT score.

Adolescent↗
PubMed1992

An introduction to bronchopulmonary dysplasia.

Bronchopulmonary dysplasia (BPD) is both a significant clinical problem associated with neonatal intensive care and a sign of the success of that care. It can best be understood in the context of the historical continuum of improving survivability for prematurely born infants. Some of the adolescents and young adults surviving with BPD will have late pulmonary dysfunction. All the molecular-biologic and technologic approaches used in the past 25 years have not clearly reduced the overall incidence of BPD. It would seem time to approach seriously the problem of decreasing the overall incidence of BPD by decreasing the incidence of premature birth in the United States.

Birth Weight↗
PubMed1990

Late pulmonary sequelae of bronchopulmonary dysplasia.

BACKGROUND: Bronchopulmonary dysplasia is a chronic lung disease that often develops after mechanical ventilation in prematurely born infants with respiratory failure. It has become the most common form of chronic lung disease in infants in the United States. The long-term outcome for infants with bronchopulmonary dysplasia has not been determined. METHODS: We studied the pulmonary function of 26 adolescents and young adults, born between 1964 and 1973, who had bronchopulmonary dysplasia in infancy. We compared the results with those in two control groups: 26 age-matched adolescents and young adults of similar birth weight and gestational age who had not undergone mechanical ventilation, and 53 age-matched normal subjects. RESULTS: Sixty-eight percent of the subjects with bronchopulmonary dysplasia in infancy (17 of the 25 tested) had airway obstruction, including decreases in forced expiratory volume in one second, forced expiratory flow between 25 and 75 percent of vital capacity, and maximal expiratory flow velocity at 50 percent of vital capacity, as compared with both control groups (P less than 0.0001 for all comparisons). Twenty-four percent of the subjects with bronchopulmonary dysplasia in infancy had fixed airway obstruction, and 52 percent had reactive airway disease, as indicated by their responses to the administration of methacholine or a bronchodilator. Hyperinflation (an increased ratio of residual volume to total lung capacity) was more frequent in the subjects with a history of bronchopulmonary dysplasia than in either the matched cohort (P less than 0.0006) or the normal controls (P less than 0.0004). Six of the subjects who had bronchopulmonary dysplasia in infancy had severe pulmonary dysfunction or current symptoms of respiratory difficulty. CONCLUSIONS: Most adolescents and young adults who had bronchopulmonary dysplasia in infancy have some degree of pulmonary dysfunction, consisting of airway obstruction, airway hyperreactivity, and hyperinflation. The clinical consequences of this dysfunction are not known.

Adolescent↗
PubMed1989

Research in departments of diagnostic radiology: a question of method limitation.

Research support, training, and methods in diagnostic radiology have been the focus of analysis for 2 decades and continue to be important in the effective competition for research grants, especially those granted by the National Institutes of Health. The limitation of hypothesis formation and testing to imaging methods alone, however, could be a major impediment to more successful sponsorship of research in this discipline. The author emphasizes that a well-designed research plan in diagnostic radiology should not be restricted solely to imaging methods and should include such factors as the formation of well-defined hypotheses testable by means of inductive reasoning and, most important, flexibility in approaches to research methods. Other factors influencing effective research in diagnostic imaging include the establishment of mentors for continuous training and support, uninterrupted time for research, and a totally supportive environment. Improvements in these areas may enhance the competitiveness of research proposals from departments of diagnostic radiology.

Diagnostic Imaging↗
PubMed1989

The effect of dexamethasone on chronic pulmonary oxygen toxicity in infant mice.

The effect of dexamethasone (0.1, 1, and 5 mg/kg/d given subcutaneously from d 14-18) was tested in infant mice continuously exposed from birth to either humidified air or 80% oxygen. Dexamethasone significantly decreased lung wet wt (p less than 0.01), lung water (p less than 0.021), lung dry wt, protein, and DNA (p less than 0.001) in both air- and oxygen-exposed animals. Dexamethasone, however, had no effect on lung compliance measured after animals were killed on d 18. It also had no effect on the increase in the blood-air barrier thickness or decrease in the blood-air exchange surface area seen in the 80% oxygen-exposed mice. Dexamethasone decreased thymus gland wt (p less than 0.001), body wt gain (p less than 0.001), brain wt (p less than 0.001), and lung lymphocytes (p less than 0.05) in both air- and oxygen-exposed animals. The effect of 1 mg/kg and 5 mg/kg of the drug could not be differentiated. During the 4 d of drug administration, one air- and one oxygen-exposed animal died; both received 5 mg/kg/d of dexamethasone; microscopic and culture evidence of infection was not found. If dexamethasone causes similar effects in human infants with bronchopulmonary dysplasia, it should be used with great caution even for short-term clinical management.

Animals↗
PubMed1985

Comparison of the effect of two and six week exposure to 80% and 100% oxygen on the lung of the newborn mouse: a quantitative SEM and TEM correlative study.

Prolonged inhalation of 80% oxygen, in contrast to 100% oxygen, has generally been assumed not to lead to significant pulmonary impairment. Two and six week old C57BL mice were systematically assessed by transmission and scanning electron microscopy for structural changes in the lung caused by inhalation of 80% and 100% oxygen from the first day of life, and the injury was quantitated morphometrically. Six weeks of continuous inhalation of 80% oxygen resulted in diffuse fibrosis of the gas exchanging parts of the lung superimposed on which were, in the 100% oxygen exposed mice, foci of coarse scarring. Lowering the inspired oxygen concentration from 100% to 80% appeared to reduce the mucosal injury more than the interstitial fibrotic response. This suggests that the most persistent alteration caused by chronic supplemental oxygen exposure below 80% will be interstitial fibrosis.

Animals↗
PubMed1983

Effect of prolonged exposure to 80% oxygen on the lung of the newborn mouse.

Continuous exposure of newborn C57BL mice to 80% oxygen at normal atmospheric pressure for as many as 6 weeks results in significant pulmonary injury. This injury is reflected morphometrically and morphologically primarily in an increase in the pulmonary interstitial compartment and in pulmonary fibrosis. The fibrotic response is both peribronchiolar and parenchymal. Lowering the oxygen concentration of continuous exposure from 100 to 80% appears to reduce the cellular response of the alveolar lining cells and the bronchiolar mucosa in the newborn lung more than the fibrotic response. This suggests that the most persistent response in the growing lung to supplemental oxygen concentrations at or below 80% will be peribronchiolar and parenchymal fibrosis. These findings would account for the clinically observed reduction of stage II bronchopulmonary dysplasia, yet persistence of chronic bronchopulmonary dysplasia in human infants treated with supplemental oxygen concentrations below 100%.

Animals↗