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Query: UMLS:C0001511 (Adhesion)
 5,955 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adhesion to epithelial respiratory cells, iron acquisition, and production of K1 polysaccharide capsules have been proposed as potential virulence factors of avian Escherichia coli. These factors were studied by inoculating groups of axenic or specific-pathogen-free (SPF) chickens intratracheally with O2 E. coli strains after previous challenge with a wild strain of infectious bronchitis virus (IBV). In all experiments, the association between IBV and an E. coli strain endowed with the three virulence factors previously mentioned resulted in the most severe pathological effects, as measured by mortality, weight gains, lesions, and reisolation of E. coli from internal organs. An E. coli strain devoid of virulence factors was able only to induce mild pathological effects restricted to the respiratory tract when combined with IBV. Both E. coli strains were more invasive in axenic chickens than in SPF chickens. These results confirm the probable involvement of the three factors studied in the pathogenic properties of avian E. coli. This model can be used to assess the role of virulence factors, by comparing pairs of positive and negative isogenic strains.
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PMID:Comparative infectivity for axenic and specific-pathogen-free chickens of O2 Escherichia coli strains with or without virulence factors. 252 66

Bacterial adhesion is probably a prerequisite for colonization of mucous membranes, but adhesion to the bronchial mucosa has not been studied in detail. We investigated adhesion of respiratory pathogens to bronchial epithelial cells, and asked whether chronic bronchitis had an influence on bacterial adhesion. Oropharyngeal and bronchial cells were collected during bronchoscopy from 14 healthy nonsmokers, 22 smokers with nonobstructive chronic bronchitis, and 19 smokers with chronic bronchitis and chronic obstructive pulmonary disease (COPD). Patients with a forced expiratory volume in one second (FEV1) less than 50% predicted were excluded. Adhesion of highly adherent test strains of H. influenzae and S. pneumoniae to these cells were studied. The test strains of H. influenzae and S. pneumoniae were found to adhere well to both oropharyngeal and bronchial cells. H. influenzae showed a higher degree of adhesion both to ciliated and goblet cells from the patients with nonobstructive bronchitis than to cells from the healthy nonsmokers. No corresponding difference was found for S. pneumoniae. The patients with COPD did not differ from the controls in their adhesion values. Our results indicate that bacterial adhesion is of importance for the colonization and retention of H. influenzae in the human airways. For S. pneumoniae the role of adhesion is more uncertain.
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PMID:Bacterial adhesion to oropharyngeal and bronchial epithelial cells in smokers with chronic bronchitis and in healthy nonsmokers. 782 81

Perennial rhinitis and asthma are clinical syndromes representing a range of overlapping pathologies; accurate classification should therefore precede any comparison. Although the sinonasal cavities, trachea and bronchi have a common respiratory mucosa, there are also anatomical differences. For example, the nose has a capacitance vessel network and the lower airways possess smooth muscle, both of which are responsive to neurohumoral influences. The prevalence of rhinitis and asthma has increased over the last three decades. Rhinitis occurs in around 75% of allergic asthmatics while 20% of perennial allergic rhinitics develop asthma. Eosinophils, and their associated proteins and cytokines, may play a central role in both perennial rhinitis and asthma with and without atopy. The characteristic pathology of asthma can be summarized as a chronic, desquamating, eosinophilic bronchitis. Non-allergic rhinitis with eosinophilia is recognized, but without consistent evidence of epithelial damage. Eosinophils are also present in rhinosinusitis with polyposis, particularly in patients with aspirin sensitivity, in whom asthma also often occurs. Increased mast cell activation and mediator release is evident in both perennial rhinitis and asthma following allergen challenge. The importance of mast cells in non-atopic asthma and polyposis is also recognized. Adhesion molecules may also be upregulated, with an increased number and activation of TH2 lymphocytes. However, allergen-resultant T-cell activation may be less marked in the nose than in the lung. Autonomic imbalance also plays a role in both conditions via changes in neural tone to effector tissues, release of neuropeptides, and interplay with cellular recruitment. Pharmacological manipulation of rhinitis and asthma also illustrates the pathological similarities and differences.
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PMID:The link between the nose and lung, perennial rhinitis and asthma--is it the same disease? 921 59