Showing papers on "Respiratory epithelium published in 1968"

Pathogenesis of the nitrogen dioxide-induced lesion in the rat lung: a review and presentation of new observations.

Abstract: Review of previous work primarily is presented. Concentrations of 10 to 25 ppM NO/sub 2/ was non-edemagenic and non-necrotizing in rats but did result in increased weight of voluminous, air-retaining lungs. Increase in lung weight was due to hypertrophy of respiratory epithelium in alveoli and terminal bronchioles, and not to excessive fluid or blood. A concentration 2 +- 1 ppM for a lifetime did not produce emphysema but reduced bronchiolar cilia, inhibited normal exfoliation and blebbing of epithelial cells, and produced cytoplasmic, crystalloid inclusions of uncertain nature.

Ultrastructural alterations produced by polycyclic aromatic hydrocarbons on rat tracheal epithelium in organ culture.

Abstract: Summary Ultrastructural alterations of columnar respiratory epithelium were produced by certain polycyclic aromatic hydrocarbons in suckling rat trachea maintained in organ culture for 11 days. The potent carcinogens 7,12-dimethylbenz(a)anthracene (DMBA) and benzo(a)pyrene and the weakly carcinogenic compounds benz(a)anthracene and 5-fluoro-7,12-dimethylbenz(a)anthracene (F-DMBA) produced cells whose cytoplasm contained little endoplasmic reticulum, many free ribosomes, complex autophagic vacuoles, and abundant cytoplasmic filaments. These cells were often connected by many desmosomes and complex interdigitations in a stratified epithelium 3 to 8 cells high, which bore a similarity to stratified squamous epithelia such as skin and also resembled bronchogenic carcinoma in situ . Some nucleolar fragmentation and disorganization also occurred in the epithelium of the carcinogentreated explants. In general, DMBA produced morphologic abnormalities at low concentrations, while the related compounds benz(a)anthracene and F-DMBA did so at concentrations 12.5- to 25-fold higher. Although autophagic vacuoles and related structures, as well as some degree of disorganization of the endoplasmic reticulum, were found in columnar cells, and increased filaments were noted in basal cells, extensive alteration of cell structure and epithelial state was not encountered in control explants or in explants treated with anthracene, benzo(e)pyrene, benzo(a)fluorene, benz(m,n,o)fluoranthene, chrysene, perinaphthoxanthene, perylene, or phenanthrene.

Development of respiratory tract cilia in fetal rabbits. Electron microscopic investigation.

Abstract: Cilia develop in the respiratory tract of rabbits during the 22–28 days in utero. In the early, “pre-cilia” stages, cuboidal cells elongate and develop microvilli on their upper or luminal surface. A large number of basal bodies are produced in the cytoplasm between the nucleus and upper surface. The basal bodies migrate towards the apical surface and orient themselves properly with respect to the surface. Finally a cilium rises above each basal body. Throughout the respiratory tract, this same sequence of steps is followed during ciliogenesis, but the upper part of the airway develops its ciliated epithelium first. The nose is followed by the larynx, then the trachea and finally the bronchi.

On the respiratory organs of amphipnous cuchia (Ham Buch).

Abstract: The respiratory organs of Amphipnous cuchia comprise a pair of aicsacs, vestigial gill filaments borne on second gill arch and vascular folds of the third gill arch. The volume of each air-sac, its surface area and its reltionship with the body weight of the fish have been determined. The air-sac is lined by a respiratory mucosa which is composed of vascular and non-vascular areas. Each vascular area, called here the ‘respiratory islet,’ studded with hundreds of vascular rosettes, which are formed of collagenous material and supported by endothelial cells. Pilaster cells are absent. The ‘islets’ are covered over by a single layer of squamous type of epithelial cells. The non-vascular areas (lanes') are the stratified part of the respiratory epithelium and contain a large number of mucous glands which secrete mainly acid mucopolysaccharides. The vascularisation of the gills have been studied by India ink injection methods. The secondary gill lamellae are absent, their place being taken up by coiled vascular loops. A quantitative estimation of haemoglobin in blood of ‘cuchia’ and other air- and water-breathing fishes have been made by colorimetric method and the results have been discussed in relation to their habit and habitats. The cranial muscles which are involved in respiration of ‘cuchia’ and the mechanics of muscle action in breathing have been described.

Studies on the pathogenesis of parainfluenza type 3 virus infection in hamsters.

Abstract: After intranasal inoculation of parainfluenza type 3 virus in hamsters, viral multiplication was detectable by infectivity titrations and immunofluorescent (FA) staining to have occurred in respiratory tissues as early as 24 hours following inoculation. Virus persisted in the respiratory epithelium up to the 6th day of infection. By FA staining, localization of viral antigen was seen in the cytoplasm of infected ciliated epithelial cells in the form of brilliant fluorescent granules of varying size.

Bio‐assay of the effects of smoking on dna content of human respiratory epithelium

Abstract: A survey of alterations in the DNA content of human oropharyngeal epithelium related to smoking was carried out. The technique used had been developed for mass screening of the DNA content of populations of intact cells and was based on the binding of acriflavine by cells in proportion to their DNA content. Groups of nonsmokers, heavy smokers and cancer cases served to establish the normal and abnormal dye‐binding ranges. Among 14 previously heavy smokers who abstained completely, there was a decline to the normal range in 6 months. The implications of this finding are discussed in connection with carcinogenesis and the application of the technique as a bio‐assay in humans for evaluating cigarettes claimed to be safe is suggested.