Showing papers on "Respiratory epithelium published in 1971"

Relationships Between Mycoplasma pneumoniae and Human Respiratory Epithelium.

Abstract: The interaction was studied between Mycoplasma pneumoniae and its natural host cell, the human respiratory epithelium. Organized, ciliated cells provided by fetal trachea in organ culture enabled examination of the host-parasite relationship by light, immunofluorescence, and electron microscopy. Impairment of cellular function was reflected by disorganization and loss of ciliary motion; this was associated with a sequence of cytopathological changes denoting progressive cell injury. The organisms were found concentrated on the luminal surface of ciliated epithelium and cells lining the submucosal glands. A differentiated portion of the Mycoplasma, consisting of an extension of the unit membrane containing an electron-dense core surrounded by a lucent space, served as the means of attachment to host cells. The findings suggest that the pathogenicity of M. pneumoniae depends upon intimate extracellular infection with production of functional and structural changes initiated by host cell membrane injury.

Vacuoles in the embryonic chick corneal epithelium, an epithelium which produces collagen

Abstract: Studies on a variety of cells which excrete protein have established that synthesis of the protein occurs in the endoplasmic reticulum and that subsequent concentration, storage, and excretion occur via the Golgi apparatus (see Beams and Kessel, 1968 for review) . Ultrastructural radioautographie studies on the mode of collagen excretion, however, have been variously interpreted in respect to the role of the Golgi apparatus, with some investigators suggesting that collagen is processed by this organelle (Revel and Hay, 1963 ; Hay and Revel, 1969) and others suggesting that it is not (Ross and Benditt, 1965 ; Cooper and Prockop, 1968 ; Salpeter, 1968). An issue central to these studies has been the frequency of radioautographie detection of secretory vacuoles which contain radioactive protein . Despite the reported quantitative differences in the frequency at which labeled secretory vacuoles have been found, it should be emphasized that vacuoles containing ultrastructurally recognizable collagen, as well as dense vacuoles of unknown content, have been described in a variety of collagen-producing cells (Stearns, 1940 ; Fitton Jackson, 1960; Sheldon and Kimball, 1962; Movat and Fernando, 1962 ; Fernando and Movat, 1963 ; Revel and Hay, 1963 ; Voelz, 1964 ; Welsh, 1966 ; Welsh and Meyer, 1967; Reith, 1968 ; Hay and Revel, 1969) . The purpose of the present report is to describe two distinct types of vacuoles in an epithelium which produces collagen, namely the embryonic chick corneal epithelium . One type of vacuole contains cross-striated aggregates like collagen, and the other type has an elongated shape and contains a dense, slightly fibrillar material .

The Fine Structure of the Surface Epithelium of the Human Ovary

Abstract: The surface epithelium has been studied on human adult ovarian biopsies, one foetal ovary and an ovarian biopsy from a woman 12 weeks pregnant. In the adult, the surface of the ovary is covered by a single, patchy layer of epithelium which varies from squamous, through cuboidal to columnar in shape. Cytoplasmic projections extend into the peritoneal cavity from the free surface of the cells and their lateral borders are connected by desmosomes. The nucleus is irregular and the dense cytoplasm contains many polysomes, free ribosomes and tonofilaments. Intracellular vacuoles and extracellular channels contain materials of low to moderate density. Lipid droplets and compound aggregates are present and both coated and smooth vesicles occur in the peripheral cytoplasm. Focal degenerative changes may be seen which range from loss of density in the basal cytoplasm to complete desquamation. In pregnancy the basal surface of the epithelium is deeply infolded with an increase in cytoplasmic lipid. In the foetal ovary the entire surface is covered with an epithelium. From these studies and the work of others, it seems clear that, although the prime function of the ovarian surface epithelium is its contribution of pregranulosa cells during foetal development, many features remain which suggest that it has an important role in transport. It may also influence follicular development in the foetus and appears to have some potential for steroid metabolism. The patchiness and degenerative changes found in the adult human ovary may be related to fluctuations in hormonal balance.

Fine structure at the basal surface of intestinal epithelium in the midgut region of the balanidae, with special reference to "Neural-like" processes.

Abstract: Observations on fine structure at the basal end of the intestinal epithelium in the midgut region of Balanus balanoides and Balanus improvisus reveal complex interrelationships among several tissues Numerous elongate cell processes extend towards the intestinal epithelium penetrating between layers of intestinal muscle through blood spaces and into the basal lamina underlying the epithelium Two types of morphological relationships occur between cell processes and the basal end of the intestinal epithelial cell: 1 The cell process may penetrate the basal lamina and lie closely apposed to the epithelium 2 The cell process may give rise to narrow, medially-directed, finger-like extensions (projections) The narrow projections penetrate the basal lamina and, in addition, terminate as dilated bulbs within inpocketings of the epithelium In some respects the cell processes are suggestive of neural tissue

Effect of extremes of temperature and humidity on the goblet cell count in the rat airway epithelium.

Abstract: Jones, R., Baetjer, A. M., and Reid, L. (1971).Brit. J. industr. Med.,28, 369-373. Effect of extremes of temperature and humidity on the goblet cell count in the rat airway epithelium. To investigate the effect of environmental temperature and humidity on the goblet cells in the rat airway epithelium, eight animals were exposed for four to five weeks to each of the following conditions: normal; hot-moist or tropical; hot-dry or desert; and cold. The animals in the three groups exposed to abnormal atmospheric conditions failed to gain weight as fast as those in the control group. No increase in the number or area of goblet cells was found in any group, although with irritants previously tested, such as tobacco smoke, a marked increase has been found in this time. It would seem that climatic effects are much less important than irritation in the production of hypertrophy and hyperplasia of mucus-secreting cells, the hallmark of chronic bronchitis.