Differential adhesion of Pseudomonas aeruginosa to human respiratory epithelial cells in primary culture.

Abstract

Human nasal polyps in outgrowth culture were used to study the Pseudomonas aeruginosa adhesion to respiratory cells. By scanning electron microscopy, P. aeruginosa were seen associated with ciliated cells, but by transmission electron microscopy, bacteria were never seen at the interciliary spaces or attached along cilia, but were identified trapped at the extremities of cilia, usually as bacterial aggregates. A fibronectin-containing fibrillar material was seen associated with aggregated bacteria. By time-lapse video microscopy, bacteria were seen to aggregate in the culture medium following their addition to the culture wells. Progressively, these aggregates were trapped by cilia or attached to migrating cells of a lower cell layer that protruded beneath the upper layer cells, at the outgrowth periphery. P. aeruginosa adhesion to these lower cell layer migrating cells was significantly higher than to ciliated or nonciliated cells of the upper cell layer. Migrating cells were intensely labeled by the complexes Con A and arachis hypogea agglutinin (PNA)-FITC, in contrast to the other cells. The percentage of PNA-labeled cells with attached bacteria was significantly higher than that without bacteria. These results suggest that changes of cell surface glycoconjugates related with cell migration may favor P. aeruginosa adhesion to respiratory cells. (J. Clin.

Parameterizing ice nucleation rates using contact angle and activation energy derived from laboratory data

“…Within each species, the variation of g a with temperature (Fig. 2a) is not significant compared to the theoretical estimations of Hagen et al (1981) and Pruppacher and Klett (1997) for homogeneous nucleation. This suggests either that our method and data are not sufficient to resolve it or that there exist other factors that diminish the temperature dependence.…”

“…As only the fractions of nucleation were provided, we again obtain their experiment time of 1 min by personal communication. In addition, we used our own Miller et al (1981); k. Mansvelt and Hattingh (1989); l. Plotkowski et al (1991); m. Levin et al (1987); n. Bragg (1969).…”

Colonization and infection in tracheostomized patients at tertiary care hospital in Eastern Nepal

“…aureus is the commonest pathogen responsible for the nosocomial infections, 16,17,18,19 especially nosocomial pneumonia, surgical wound infection, and bloodstream infection. 20 Infection with Staphylococcus contributes significantly to patient's morbidity and mortality.…”

Gene transfer by guanidinium-cholesterol cationic lipids into airway epithelial cellsin vitroandin vivo

“…Interestingly, in this type of cell culture system, the cells from the periphery of the outgrowth have been characterized as migrating cells, mimicking the poorly differentiated regenerating cells present in vivo during the repair of the airway epithelium (17). These results invited us to define more precisely the differentiation state of the transfected edge cells in our cell culture system.…”