ISSN:0894-2684    

DOI:10.1089/jam.1988.1.1

年代:1988

数据来源: MAL

摘要:

ABSTRACTTo determine if clearance from ciliated airways is complete in 24 hrs, we measured whole lung and regional clearance of radiolabeled aerosols over 24 hrs in a large number of normal and diseased individuals. Using a gamma camera and computer analysis, we found small but significant amounts of aerosol in the central airways of normal subjects, and greater central retention in some patients with obstructive lung disease. In patients, a significant factor related to the central retention of aerosol was the presence of chronic flow limitation during tidal breathing. Whole lung retention in normal lungs correlated with the initial pattern of aerosol deposition, but not in disease. We conclude that the 24 hr image often contains a significant amount of deposited aerosol in central airways and not just alveoli. In addition, the presence of flow limiting segments in central airways is associated with prolonged retention of aerosol in patients with obstructive lung disease.

ISSN:0894-2684    

DOI:10.1089/jam.1988.1.11

年代:1988

数据来源: MAL

摘要:

ABSTRACTThe importance of an impaired mucociliary clearance in the respiratory tract for the pathogenesis of chronic lung diseases as chronic bronchitis, asthma, bronchiectasis and lung cancer is evaluated. This is performed mainly by comparing clinical picture, lung function data and mucociliary clearance in these diseases with corresponding data in the Immotile Cilia Syndrome (ICS). This disease may be caused by various defects in the cilia, all of which result in an absent or severely impaired mucociliary transport which makes it an ideal model disease for evaluating the importance of the mucociliary system. From such comparisons it seems probable that impaired mucociliary transport is one major factor for the pathogenesis of several cases of bronchiectasis and of the airways obstruction associated with chronic bronchitis. The role of impaired mucociliary clearance for the pathogenesis of the other lung diseases is still unclear.

ISSN:0894-2684    

DOI:10.1089/jam.1988.1.21

年代:1988

数据来源: MAL

摘要:

ABSTRACTAn inspired aerosol bolus of a defined volume injected at the end of an inhalation of particle free air was used to study particle losses and airway dimensions of the tracheo-bronchial tree. The penetration of the bolus into the lungs, the expired reserve volume, ERV, and the breathing posture were varied. From experiments with different breath-holding times after inhalation an effective airway diameter, DA, was evaluated for a preset bolus penetration. With decreasing ERV and increasing penetration the determined DAdecreases. The lying posture of the subject yielded a smaller DAthan the sitting position. Effective airway diameters greater than 2 mm were found if the volumetric penetration of the bolus maximum is less than 50 cm3.

ISSN:0894-2684    

DOI:10.1089/jam.1988.1.29

年代:1988

数据来源: MAL

摘要:

ABSTRACTA theoretical model was developed to calculate the deposition of inhaled fibrous particles in the human lung. In the derivation of deposition formulae, the simultaneous effects of the velocity shear in the air flow and Brownian rotation on particle orientation were considered. Total deposition of fibers in the lung at mouth breathing was found to be smaller than that of spherical ones with the same mass, and deposition in the lung at nose breathing showed considerably lower deposition than that at mouth breathing. Calculated deposition in the alveolar region of the lung from this model compared favorably with the postmortem data.

ISSN:0894-2684    

DOI:10.1089/jam.1988.1.37

年代:1988

数据来源: MAL

摘要:

ABSTRACTWe have developed a new experimental animal model, called the cross-ventilating rat model, for use in pharmaco- and toxicokinetic studies involving the inhalation of traceable agents. The model consists of two anesthetized rats interfaced in a manner so that the lower respiratory tract of one of the participants (Nasal Compartment Recipient, NCR) "breathes" through the nasal compartment of the other participant (Nasal Compartment Donor, NCD), with each of the animals being contained in a separate partial body flow plethysmograph. While in this configuration, the tidal volumes, breathing frequencies, minute ventilations, inspiratory and expiratory times, arterial blood pH, arterial oxygen and carbon dioxide tensions, dynamic lung compliances, and lung resistances of the NCD and NCR animals are closely similar to those of equivalently anesthetized intact animals. In terms of these criteria, the cross-ventilating rat model was found to be stable for at least three hours.

ISSN:0894-2684    

DOI:10.1089/jam.1988.1.51

年代:1988

数据来源: MAL