Roger A Francis

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The effect of ipratropium bromide, a new anticholinergic drug, on the rate of clearance of secretions from the lung and on airways resistance was investigated in 12 healthy subjects in a double-blind cross-over trial with placebo and a control run without aerosol. Before taking the drug the subjects inhaled uniform 5 micrometer tracer particles of(More)
Coronary artery calcification (CAC) is usually detected by fluoroscopy or on cine films during coronary angiography, but measurement of the calcification is not possible. Gated tomography of the heart provides a full sized image with high contrast spatial resolution of 0.1 mm and low contrast spatial resolution of 0.76 mm. The radiation exposure to the(More)
Quantitative indices are described for assessing the distribution of ventilation imaging agents (radioaerosols, in particular) within the lung. They have been applied to images obtained with 99Tcm aerosol particles (0.5-2.0 micrometer diameter) and with 81Krm gas in 12 patients with a wide range of lung function. In patients with normal lung function(More)
We studied eight young smokers and ten nonsmokers, to determine whether respiratory epithelial permeability to radiolabelled diethylenetriamine penta-acetate (99mTcDTPA) was related to small airway function or bronchial reactivity. Permeability was measured in inner (containing central airways) and outer lung zones by gamma camera. Lung-to-blood half-time(More)
The anatomy and physiology of the pulmonary epithelial barrier are briefly described, and methods of measuring permeability of the barrier to solutes are outlined, including findings on alveolar barrier permeability to 99mTcDTPA. A method for measuring permeability to 99mTcDTPA of the conducting airways is described in which the effect of mucociliary(More)