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Showing papers on "Respiratory epithelium published in 1976"


Journal ArticleDOI
TL;DR: Histoligic study of the columnar-lined esophagus demonstrated a spectrum of epithelial patterns, which helps to explain prior discrepant reports.
Abstract: To define the histology of the columnarlined esophagus, we obtained esophageal biopsies from various levels with manometric control from 11 patients. There were three types of columnar epithelia above the lower esophageal sphincter: atrophic gastric-fundic-type epithelium with parietal and chief cells; junctional-type epithelium with cardiac mucous glands; and distinctive specialized columnar epithelium with a villiform surface, mucous glands and intestinal-type goblet cells. When present, specialized columnar epithelium was always the most proximal, and gastric fundic epithelium the most distal epithelium. Junctional epithelium was interposed between gastric fundic and specialized columnar or squamous epithelium. Four patients had unequivocal esophagitis in squamous epithelium, but its presence and severity did not correlate with inflammation in or length or type of distal columnar epithelium. Histologic study of the columnar-lined esophagus demonstrated a spectrum of epithelial patterns. This h...

734 citations


Journal ArticleDOI
TL;DR: Data suggest a specificity of interation between virulent M. pneumoniae and tracheal epithelial cells that can be further examined through the use of isotopically labeled mycoplasmas.
Abstract: In the pathogenesis of infectious diseases, the infecting organism may gain entrance into the host by trauma or the bite of a vector on the external skin; however, most infections begin on the much larger internal surface areas of the respiratory, gastrointestinal or urogenital systems covered by mucous membranes. In order to be successful in establishing an infection, the microbial organism must overcome the defense mechanisms present on mucous membranes and be able to attach and multiply on the lining epithelial cells (Smith, 1977).

130 citations


Journal Article
TL;DR: The tracer proteins, horseradish peroxidase and ferritin, placed in the trachea of guinea pigs were taken up by epithelial cells and transported to the extracellular space and this transport may be of importance in the late onset type of asthma.

88 citations


Journal Article
TL;DR: It is felt that the infant ferret is an acceptable model for the study of respiratory syncytial virus disease and that theStudy of age dependence observed in ferrets may allow elucidation of the mechanisms involved in the age dependence seen in humans.
Abstract: The infant ferret is susceptible to respiratory syncytial virus infection in both the upper and lower respiratory tracts. In the nose, viral replication is restricted to the surface respiratory epithelium in the nasal passages and turbinates. In the lungs, viral replication is of a lower order of magnitude and is localized in the alveolar cells. The pattern of viral replication in nasal tissues is independent of the age of the animal at infection, whereas the pattern in lung tissues shows a striking age dependence, with viral replication progressively decreasing as a function of age. Thes age dependence appears to be due to an intrinsic age-related mechanism yet to be defined. We feel that the infant ferret is an acceptable model for the study of respiratory syncytial virus disease and that the study of age dependence observed in ferrets may allow elucidation of the mechanisms involved in the age dependence seen in humans.

88 citations


Journal Article
TL;DR: Human bronchial epithelium has been maintained in organ culture in serum-supplemented medium for 4 months, and the basal lamina was frequently covered by 2 or 3 layers of epithelial cells consisting of nonkeratinizing squamous cells with short microvilli and small mucous granules.
Abstract: Summary Human bronchial epithelium has been maintained in organ culture in serum-supplemented medium for 4 months. After 4 to 6 weeks in culture, various changes in morphology were apparent. There was an increase in autophagic vacuoles in mucous, ciliated, and basal cells, a reduction in the height of the columnar cells, a decrease in the number of goblet mucous cells, and an increase in cells with small mucous granules. After 3 months in culture, the basal lamina was frequently covered by 2 or 3 layers of epithelial cells consisting of nonkeratinizing squamous cells with short microvilli and small mucous granules. Less frequently, keratinizing squamous cells were seen. Differentiated epithelium incorporated precursors into macromolecules in serum-free medium, supplemented with vitamin A, at 1 week of culture. These explants exhibited changed epithelium by 2 weeks, similar to that described for epithelium in serum-supplemented medium after 4 to 6 weeks.

80 citations


Journal ArticleDOI
TL;DR: The morphological complexity of the epithelium of the ductus deferens suggests that the epithelial cells of this region of the genital ducts, like those of more proximal regions, perform functions of importance to the spermatozoa.
Abstract: Specimens of the ductus deferens from normal adult men of proven fertility were examined with the light and electron microscope. The wall of the ductus deferens is made up of a mucosa, three codcentric layers of smooth muscle and an adventitia. The epithelium, together with the underlying connective tissue of the lamina propria, is thrown up into longitudinal folds. The pseudostratified epithelium covering the folds is composed of small basal cells which form a discontinuous layer along the basement membrane and tall thin columnar cells which extend from the base of the epithelium to the lumen. In addition to basal cells, at least three different types of columnar cells can be distinguished in the electron microscope: principal cells, pencil cells and mitochondrion-rich cells. Lymphocytes are found scattered amongst the epithelial cells. The morphological complexity of the epithelium of the ductus deferens suggests that the epithelial cells of this region of the genital ducts, like those of more proximal regions, perform functions of importance to the spermatozoa.

64 citations


Journal ArticleDOI
TL;DR: The proposition that new supportive epithelial cells originate from cells of Bowman's gland is supported, as well as the integrity of the subadjacent connective tissue, which was mostly well-preserved.
Abstract: Degeneration and early regeneration of olfactory epithelium from two strains of mice was studied at the light and electron microscopic levels from 12 hours to 3 days following nasal irrigation with 1% aqueous solution of zinc sulfate (ZnSO4) (a compound known to selectively damage olfactory epithelium). Distinct patterns of degeneration and stages of regeneration were evident following treatment. During the first 24 hours after treatment three progressive manifestations of the degenerative process were seen: (1) a relatively mild condition which was characterized by surface irregularities produced by cell protrusions, highly vacuolated cytoplasm, presence of large lysosome-like bodies and prominent intercellular spaces, (2) a more severe condition in which large areas of the epithelium were detached from the basement membrane cellular debris was present in the nasal chamber, and (3) a condition of total or near-total denudation of the epithelium of olfactory mucosa. The basal lamina was continuous and intact in most regions and the integrity of the subadjacent connective tissue was mostly well-preserved. Nerve bundles of the fila olfactoria were noted in varying degrees of degeneration during the course of the experiment. The most advanced neural degeneration was seen 24 to 72 hours after treatment. Onset of regeneration was suggested by the appearance of a simple squamous layer of cells above the basement membrane 48 to 72 hours after treatment. In addition to the simple epithelium a stratified epithelium consisting of two to four cell layers was also observed at this time. Glandular cells, containing secretory granules identical to those in Bowman's glandular cells, were noted in an apparent process of migration from the lamina propria into the the stratified epithelial layer. The last mentioned observation supports the proposition that new supportive epithelial cells originate from cells of Bowman's gland.

63 citations


Journal ArticleDOI
TL;DR: The data indicate that the intimate contact between virulent mycoplasmas and the respiratory epithelium does not alone account for the subsequent interruption of host cell metabolism but must be accompanied by continued multiplication and biochemical function of attached mycplasmas.
Abstract: Exposure of hamster tracheal organ cultures to virulent Mycoplasma pneumoniae leads to alterations in ribonucleic acid (RNA) and protein biosynthesis and metabolism of the respiratory epithelium. An examination of the turnover rates of RNA and protein in infected tracheal organ cultures indicates that the rates of degradation of both prelabeled host cell RNA and protein are similar to those of uninfected controls. Infected tracheal organ cultures shifted to a nonpermissive medium within 24 h after infection and further incubated in the nonpermissive medium for 72 or 96 h behaved as normal uninfected cultures in terms of metabolic precursor uptake. Under these conditions, mycoplasmas remained attached to the respiratory epithelium. Cell membranes prepared from virulent mycoplasmas by several procedures neither attached to nor altered the metabolic activity of tracheal cultures. These data indicate that the intimate contact between virulent mycoplasmas and the respiratory epithelium does not alone account for the subsequent interruption of host cell metabolism but must be accompanied by continued multiplication and biochemical function of attached mycoplasmas.

60 citations


Journal ArticleDOI
TL;DR: It is postulated, that the dark secretory granules are prestages of the actual secretory product presenting as lightgranules and that dark and light granules do not represent different secretory capacities of the cell.
Abstract: Histologic studies of recent years have definitely concluded that the epithelium of the middle ear is a modified respiratory epithelium with ciliated and secretory cells, including goblet cells. These cells, like the ciliated cells, are developd from the basal cell and are just ordinary secretory cells completely filled with secretory granules. For different reasons it is postulated, that the dark secretory granules are prestages of the actual secretory product presenting as light granules and that dark and light granules do not represent different secretory capacities of the cell. The subepithelial layer which consists of loose connective tissue is a structure of just as great importance as the epithelial layer.

41 citations


Journal ArticleDOI
TL;DR: Changes in ciliated and goblet cells of the rat tracheal epithelium are indicative of rapid restoration of barrier function after mild injury to the respiratory tract lining as a first step in the reparatve process.
Abstract: Mechanical injury to ciliated and goblet cells of the rat tracheal epithelium results in sloughing of these cells. The basal cells of the pseudostratified epithelium remain. These cells, studied by scanning electron microscopy, transmission electron microscopy, and en face light microscopy after silver staining, are rounded and separated from one another for the first 2 hours after injury. They become flat and are apposed to each other by 4 hours after injury, but inter-cellular junctions are not uniformly present until 6 hours after injury. By that time, early evidence of stratification of cells is observed, and lanthanum hydroxide, as a colloidal tracer placed in the tracheal lumen, is excluded from the spaces between cells. The changes are indicative of rapid restoration of barrier function after mild injury to the respiratory tract lining as a first step in the reparatve process.

34 citations


Journal ArticleDOI
TL;DR: Cell turnover in the rat airway epithelium has been studied at 5 levels of the bronchial tree after administration of either colchicine or tritiated thymidine, and in male and female rats of 3 age groups, the first study to include all these features of the same species.
Abstract: Cell turnover in the rat airway epithelium has been studied at 5 levels of the bronchial tree after administration of either colchicine or tritiated thymidine, and in male and female rats of 3 age groups. This is the first study to include all these features of the same species. In the young animals the Mitotic Index (number of cells in division per 1,000 nuclei) decreased progressively to the periphry and was higher in the male than in the female, although the rate of weight gain was the same for both. In the oldest animals no difference was observed between the various airway levels or between the sexes. In the intermediate group the proximal to distal decrease was apparent but the difference with sex was not. The concentration of cells per unit length of airway is higher in the trachea and main bronchus than in intrapulmonary airways. (In the intrapulmonary airways virtually no basal cells are present.) This means that a given Mitotic Index represents replacement of a larger area of epithelium in small airways than in large ones.

Journal ArticleDOI
TL;DR: In the newborn opossum lung, examination of the air chambers with the scanning electron microscope permits the observation of several type II pulmonary epithelial cells in a single field.
Abstract: The air chambers of the newborn opossum are lined by a respiratory epithelium which appears similar to that lining alveoli of other species. The type II pulmonary epithelial cell is cuboidal in shape, shows apical microvilli, several Golgi complexes, lipid droplets, and numerous cytosomes. The cytosomes contain osmiophilic lamellae and are similar in appearance to whorls of osmiophilic material lying free within the alveolar lumina and on the surface of the respiratory lining epithelium. In the newborn opossum lung, examination of the air chambers with the scanning electron microscope permits the observation of several type II pulmonary epithelial cells in a single field. The potential use of the air chamber of the newborn opossum as an experimental model is suggested.

Journal ArticleDOI
TL;DR: There was a complete recovery of the ability of tracheal epithelium to respond to interferon inducers after the mice were returned to ambient air 24 days post ozone exposure, however, ozone did not seem to have any affect on the capacity of the alveolar macrophages to produce interferons in vitro.
Abstract: The effects of 0.8 ppm ozone on the capacity of the tracheal epithelium and alveolar macrophages of mice to produce interferon in vitro was studied. Exposure of mice to ozone for a period of 11 days or more affected the capacity of the tracheal epithelial cells in vitro to produce interferon. The inability of the tracheal epithelium in vitro to produce interferon was not due to the inhibition in the release of intracellular interferon but to an inhibition in the production of interferon. There was a complete recovery of the ability of tracheal epithelium to respond to interferon inducers after the mice were returned to ambient air 24 days post ozone exposure. However, ozone did not seem to have any affect on the capacity of the alveolar macrophages to produce interferon in vitro.

Journal Article
TL;DR: The oesophageal epithelium of the newborn opossum generally is two to three cells in depth and in some regions appears pseudostratified, but in the adult it has assumed a more mature appearance and is of greater depth.
Abstract: The oesophageal epithelium of the newborn opossum generally is two to three cells in depth and in some regions appears pseudostratified. By the 9th postnatal day the epithelium shows two distinct strata. Ciliated cells and occasional goblet cells also are observed within the epithelium during this stage and in subsequent stages. Cilia persist in the oesophagus of the adult opossum, but are restricted to the depths of the transverse folds found in the distal part of the organ. The epithelium covering the transverse folds of the adult likewise has an immature appearance. By 4-5 cm (ca. 20 days), the epithelium has assumed a more mature appearance and is of greater depth. This and later stages show three basic strata: a germinal layer, a spinous layer and, adjacent to the lumen, a flattened layer of cells that retain their nuclei. The epithelium throughout the postnatal period and in the adult does not undergo complete keratinization. The oesophageal glands begin as outgrowths from the epithelium just prior to 4-5 cm (ca. 20 days). The glands continue their development throughout the remainder of the postnatal period. The secretory units of the oesophageal glands of the the major portion of the secretory elements, and a light, rounded cell type which is less numerous and which occupies the terminal portions of the secretory units. Secretory material of the former appears complex, consisting of both neutral and acid glycoproteins. The secretory product of the light cell type is unknown at present. Both cell types are encompassed by myoepithelial cells. The relationship of the mitotic sequences to the observations made by microscopic examination of the developing oesophagus is discussed.

Journal Article
TL;DR: The mode of production of peroxidase in goblet cells is concluded to be similar to that of secretory proteins in pancreatic exocrine cells, which is thought to serve as an anti-infectious agent in tears.
Abstract: Cytochemical investigation of peroxidase was made on the conjunctival goblet cells, using the diaminobenzidine method. Many goblet cells in the conjunctiva demonstrated this reaction. The reaction was present in secretory granules as well as in the perinuclear cisterna, the rough endoplasmic reticulum, several Golgi saccules and adjacent small smooth-surfaced vesicles, and condensing vacuoles. Each secretory granule within a goblet cell showed a different degree of reaction, hence it is concluded that some goblet cells probably produce both mucous substance and peroxidase in one cell. The mode of production of peroxidase in goblet cells is concluded to be similar to that of secretory proteins in pancreatic exocrine cells. The enzyme, together with thiocyanate and endogenous hydrogen peroxide, is thought to serve as an anti-infectious agent in tears.

Journal ArticleDOI
TL;DR: The data suggest that damage to the plasmalemma by chromates may be responsible for the observed change in ciliostasis in tracheal organ culture, similar to the progressive degenerative changes that result from other chemical injuries.
Abstract: Exposure to chromates is an occupational hazard that may result in disease of the respiratory tract. Specific subcellular effects of exposure to this chemical that might be the basis for observed pathologic findings were assessed in tracheal organ culture and excised whole tracheas. Chromate concentrations of 10 mg/ml or more were found to induce ciliostasis within 20 minutes and to kill cells within 24 hours. Levels between 10mug/ml and 100 mug/ml were not ciliostatic but resulted in cytotoxicity after a delay of several hours. Ultrastructural alterations associated with chromate-induced cytotoxicity are similar to the progressive degenerative changes that result from other chemical injuries. An inhibitory effect of chromate on protein synthesis, RNA synthesis, or succinic dehydrogenase activity could not be demonstrated. The data suggest that damage to the plasmalemma by chromates may be responsible for the observed change.

Journal Article
TL;DR: In this article, hyperplastic-metaplastic lesions were produced in transplanted rat tracheas by exposure to 310 or 75 µg 7,12-dimethylbenz(a )anthracene or to 650 µg benzo( a )pyrene delivered over a 2-week exposure period.
Abstract: Hyperplastic-metaplastic lesions were produced in transplanted rat tracheas by exposure to 310 or 75 µg 7,12-dimethylbenz( a )anthracene or to 650 µg benzo( a )pyrene delivered over a 2-week exposure period. Tissue recovery was studied for up to 16 weeks. After cessation of carcinogen exposure, most of the hyperplastic-metaplastic epithelium was rapidly replaced by mucociliary epithelium. In the 7,12-dimethylbenz( a )anthracene-exposed tracheas, a few metaplastic foci remained at 4 and 8 weeks. In all 3 exposure groups, portions of the mucosa were occuplied by atrophic-pleomorphic epithelium that persisted throughout the observation period. The significance of these lesions in the evolution of neoplasia is as yet unknown. In vitro studies with epithelial cells derived from 7,12-dimethylbenz( a )anthracene-exposed tracheal transplants revealed that some cells have acquired a growth potential that is markedly different from that of normal mucociliary epithelium. This altered in vitro growth potential of epithelial cells may be an early indicator of an important event in the evolution of epithelial transformation in vivo .

Journal ArticleDOI
01 Oct 1976
TL;DR: Only crocodilians posses olfactory epithelium, and naso-lachrymal gland gives them a supplementary protection, necessary in semiaquatic environment, after comparing with other Tetrapods.
Abstract: The vestibulum is very short and lined by stratified squamous epithelium which contains many “alveolar” cells. The cavum nasi proprium is exceedingly complex, with three conchal formations and a series of six recesses and sinuses. Olfactory epithelium lines the whole dorsal or dorso-medial half of the cavum, but not the deep sinuses. Non sensory respiratory epithelium lines the ventral or ventro-lateral half of the cavum, all the caviconchal recess, the posterolateral recess, the postturbinal sinus, the postconchal cavity, and the nasopharyngeal duct. In olfactory epithelium the proportion of sensory cells is about 61 % inCrocodylus and 59 % inCaiman; the ratio of sensory cells to supporting cells is about 2.6/1 in the former and 1.8/1 in the latter. Bowman's glands are sero-mucous and normally developed. As in other reptiles, the respiratory epithelium is composed with mucous and ciliated cells; but, in ventrolateral part of the cavum, there are also sero-mucous cells forming small multicellular glands. The hypertrophied lachrymal duct constitutes a very large naso-lachrymal not previously described gland. The lumen is lined by mucous and ciliated cells, the collet of each branched tubular gland by mucous cells and the glandular tubes by sero-mucous cells. Adult crocodilians lack a Jacobson's organ and there are no vomeronasal sensory epithelium in the cavum. In reptiles, aquatic way of life generally involves regression in olfactory epithelium, while Jacobson's organ (or, in Testudines, vomeronasal epithelium) persists and occasionally increases. In crocodilians, things are exactly reverse. After comparing with other Tetrapods, it seems likely that Jacobson's organ has been lost by terrestrial ancestor of crocodilians and birds. Now, only crocodilians posses olfactory epithelium, and naso-lachrymal gland gives them a supplementary protection, necessary in semiaquatic environment.


Journal ArticleDOI
Masaru Yoda1
TL;DR: It is probably assumed that the brush cell plays a role of an endocrine function to secret the containing granules into the connective tissue of the tracheal mucous membrance in rats and no epithelioneural junctions can be discerned between the brush cells and the nerve endings in the epithelium.
Abstract: To elucidate the ultrastructural organization of the tracheal epithelium and especially the fine structure of the non-ciliated cells (brush cells), the electron microscope observations were carried out. Many rats in the postnatal developmental stages and adult ones were used in this study. The tracheal epithelium of the rats is composed of a simple columnar or a pseudostratified ciliated epithelium, and it contains four distinct types of cells; ciliated cells, mucous cells (goblet cells), basal cells, and non-ciliated cells (brush cells). The ciliated cell has a clear cytoplasm compared with those of the other types of cells and favorable amount of cell organelles. Sometimes, the process of the ciliogenesis can be sproradically seen in the presumably ciliated cells early in the postnatal developmental stages and also in the adult ones. The mucous secretory cells with a fairly dense cytoplasm provided with plenty of rER and other cell organelles are more predominant in number in immature rats. However, there are scarcely seen the mucous cells provided with a typical goblet composed of many secretory granules in the apical cytoplasm. Non-ciliated cells aligned the luminal surface of the tracheal epithelium are divided into two categories, one is the mucous secretory cell and the other is the so-called brush cell provided with the brush border on its luminal surface, and the latter also contains many characteristic granules of small size. Some of these granules contain a dense spherical core, and frequently situate in the basal part or along the lateral cell boundary clustered in small groups. On the other hand, there are frequently observed many naked nerve endings, and most of them contain both small clear vesicles and large cored vesicles, and others contain also small granular vesicles, neurotubules, small mitochondria or scarce glycogen particles. However, no epithelioneural junctions can be discerned between the brush cells and the nerve endings in the epithelium. These findings mentioned above may be probably assumed that the brush cell plays a role of an endocrine function to secret the containing granules into the connective tissue of the tracheal mucous membrance in rats.