Specific modulation of airway epithelial tight junctions by apical application of an occludin peptide

Tight junctions are directly involved in regulating the passage of ions and macromolecules (gate functions) in epithelial and endothelial cells. The modulation of these gate functions to transiently regulate the paracellular permeability of large solutes and ions could increase the delivery of pharmacological agents or gene transfer vectors. To reduce the inflammatory responses caused by tight junction-regulating agents, alternative strategies directly targeting specific tight junction proteins could prove to be less toxic to airway epithelia. The apical delivery of peptides corresponding to the first extracellular loop of occludin to transiently modulate apical paracellular flux has been demonstrated in intestinal epithelia. We hypothesized that apical application of these occludin peptides could similarly modulate tight junction permeability in airway epithelia. Thus, we investigated the effects of apically applied occludin peptide on the paracellular permeability of molecular tracers and viral vectors in well differentiated human airway epithelial cells. The effects of occludin peptide on cellular toxicity, tight junction protein expression and localization, and membrane integrity were also assessed. Our data showed that apically applied occludin peptide significantly reduced transepithelial resistance in airway epithelia and altered tight junction permeability in a concentration-dependent manner. These alterations enhanced the paracellular flux of dextrans as well as gene transfer vectors. The occludin peptide redistributed occludin but did not alter the expression or distribution of ZO-1, claudin-1, or claudin-4. These data suggest that specific targeting of occludin could be a better-suited alternative strategy for tight junction modulation in airway epithelial cells compared with current agents that modulate tight junctions.

A Bronchoscopic scoring system for airway secretions - Airway cellularity and microbiological validation

There is currently no validated scoring system for quantification of airway secretions in children. A user friendly, valid scoring system of airway secretions during flexible bronchoscopy (FB) would be useful for comparative purposes in clinical medicine and research. The objective of this study was to validate our bronchoscopic secretion (BS) scoring system by examining the relationship between the amount of secretions seen at bronchoscopy with airway cellularity and microbiology. In 106 children undergoing FIB, the relationship of BS grades with bronchocalveolar lavage (BAL) cellularity and infective state (bacterial and viral infections) were examined using receptor operator curves (ROC). BAL was obtained according to European Respiratory Society guidelines; first lavage for microbiology and second lavage for cellularity Area under the ROC was significant for total cell count (TCC) and neutrophil % but not for lymphocyte %. BS grade significantly related to infection positive state (chi(2)(trend) = 5.85, P = 0,016). The area under the ROC for infection positive state versus BS grade was 0.645, 95% Cl 0.527-0.763. The BS scoring system is a valid method for quantifying airway secretions in children undergoing bronchoscopy The system related well to airway cellularity and neutrophilia, as well as to an airway infective state. However, the system is only complementary to cell counts and cultures and cannot replace these laboratory quantification techniques.

Downregulation of IgE antibody and allergic responses in the lung by epidermal biolistic microparticle delivery

Background: Biolistic injections provide a needle-free delivery of antigen-laden microparticles to the epithelium. The precision of the injection preferentially targets the Langerhans cell network, which, although ideal for vaccination, might not be suitable for the downregulation of immune responses in immunotherapy. Objective: We sought to determine the ability of biolistic injection of antigen into the epithelium of sensitized mice to inhibit IgE antibody and lung inflammatory responses produced by further exposure to antigen. Methods: Mice were sensitized by means of a needle injection of ovalbumin (OVA) in alum and given a series of biolistic injections of OVA or vehicle control, followed by a boost of OVA in alum. Serum IgE and IgG antibodies were measured before and after the boost. The mice were then challenged intranasally, and the infiltration of inflammatory cells was measured by means of bronchoalveolar lavage. Airway reactivity of the challenged mice was measured by examining responses to methacholine with forced oscillatory techniques. Results: Biolistic injection of OVA into the dorsal skin of sensitized mice markedly inhibited IgE and IgG1 antibody responses induced by boosting. IgG2a antibody responses were reduced rather than stimulated. The eosinophilic inflammation in the bronchoalveolar lavage fluid induced by intranasal challenge was also markedly inhibited. Lung hyperreactivity showed an initial increase and then a decrease of responsiveness to methacholine, with elastance returning to the level of unsensitized mice. Biolistic injection into the buccal epithelium was also inhibitory. Conclusions: Biolistic injection of allergen inhibited the boosting of IgE antibody and eosinophilic lung inflammatory responses without inducing TO immunity.

Comparison of the Berman Intubating Airway and the Williams Airway Intubator for fibreoptic orotracheal intubation in anaesthetised patients

Sixty patients with no clinical indicators of a difficult airway were selected to undergo a fibreoptic assessment after induction of general anaesthesia using both the Berman Intubating Airway and the Williams Airway Intubator. The bronchoscopic view and ease of railroading a tracheal tube during fibreoptic orotracheal intubation were studied. The bronchoscopic views obtained by the Berman Airway and the Williams Airway were significantly different (p < 0.008, test of symmetry). The estimated odds ratio of obtaining an obstructed path was 3.06 times higher for the Berman than the Williams Airway. However, if the glottis could be reached with the bronchoscope, there was no significant difference in the degree of ease of intubation between the two airways.

Monitoring inflammation and airway remodeling by FMT in a chronic asthma model

Asthma is a multifactorial disease for which a variety of mouse models have been developed. A major drawback of these models is represented by the transient nature of the airway pathology peaking 24 to 72 hours after challenge and resolving in 1 to 2 weeks. The objective of this study is to characterize the temporal evolution of pulmonary inflammation and remodeling in a recently described mouse model of chronic asthma (8 week treatment with 3 allergens relevant for the human pathology: Dust mite, Ragweed, and Aspergillus; DRA). We studied the DRA model taking advantage of fluorescence molecular tomography (FMT) imaging using near-infrared probes to non-invasively evaluate lung inflammation and airway remodeling. At 4, 6, 8 or 11 weeks, cathepsin- and metalloproteinase-dependent fluorescence was evaluated in vivo. A subgroup of animals, after 4 weeks of DRA, was treated with Budesonide (100 µg/kg intranasally) daily for 4 weeks. Cathepsin-dependent fluorescence in DRA-sensitized mice resulted significantly increased at 6 and 8 weeks, and was markedly inhibited by budesonide. This fluorescent signal well correlated with ex vivo analysis such as bronchoalveolar lavage eosinophils and alveolar cell infiltration. Metalloproteinase-dependent fluorescence was significantly increased at 8 and 11 weeks, nicely correlated with collagen deposition, as evaluated histologically by Masson’s Trichrome staining, and airway epithelium hypertrophy, and was also partly inhibited by budesonide. In conclusion, FMT proved suitable for longitudinal study to evaluate asthma progression, both in terms of inflammatory cell infiltration and airway remodeling, allowing the determination of treatment efficacy in a chronic asthma model in mice.

Organizational resources enabling service responsiveness:evidence from Greece

This article examines the implementation of relationship marketing strategy based on a sample of business-to-business firms operating in Greece. Organizational resources, including a focus on learning and flexibility/adaptation in strategic planning, are demonstrated to be antecedents of effective relationship marketing strategies. The possession of these resources lead to superior customer performance (as measured by customer satisfaction and loyalty) and, ultimately, superior financial performance (as measured by profit levels, profit margin, and ROI). Our results provide support for the development of organizational resources that foster and enable relationship marketing in business-to-business environments since such resources are linked with improved firm performance. © 2003 Elsevier Inc. All rights reserved.