Progress of epithelial-mesenchymal transition in respiratory system and the modulatory mechanism of cell adhesion / 生理学报

Epithelial-mesenchymal transition (EMT) plays an important role in the development and pathogenesis of respiratory system. Epithelial cells are characterized by well-developed, intercellular contacts, whereas EMT triggers the sequential destabilization of cell-cell adhesive junctions. The dynamic remodeling of the epithelial cell adhesion molecules is important for maintaining the integrity and normal function of epithelium. This paper reviews the research progress of EMT in lung development, lung injury repair and chronic lung diseases, and summarizes the effect of cell junctions and cell adhesion molecules on EMT molecular events.

Allergens-induced sensitization alters airway epithelial adhesion molecules expression in mice / 生理学报

To explore the relationship between the epithelial adhesion molecules and immune responses of airway epithelium, we observed the expression of integrin β4 and intercellular adhesion molecule-1 (ICAM-1) in the mice airway epithelium after sensitization with allergens. BALB/c mice were sensitized with intraperitoneal injection of ovalbumin (OVA) or house dust mite (HDM) and then developed airway hyper-responsiveness as determined by barometric whole-body plethysmography. Both OVA and HDM sensitization led to increases of the number of peripheral leukocytes as well as inflammatory cells infiltration in lungs. OVA sensitized mice showed more severe inflammatory cells infiltration than HDM sensitized mice. Immunohistochemistry analysis of mice lung tissues revealed that sensitization with both allergens also led to a decrease of integrin β4 expression and an increase of ICAM-1 expression in airway epithelia. OVA sensitized mice showed a more significant increase of ICAM-1 expression compared with HDM sensitized mice. siRNA mediated silencing of integrin β4 gene in 16HBE cells resulted in an up-regulation of ICAM-1 expression. Our results indicate a possible role of airway epithelial adhesion molecules in allergen-induced airway immune responses.

Clinical audit of the microbiology of otorrhoea referred to a tertiary hospital in Singapore

<p><b>INTRODUCTION</b>Otorrhoea is a common complaint in Ear, Nose and Throat clinics. This study aimed to establish the pathogens involved in cases of otorrhoea in Singapore, their sensitivity patterns and the effectiveness of empirical management.</p><p><b>METHODS</b>A retrospective chart review was conducted on 91 patients with otorrhoea who had undergone swab cultures between July 2010 and February 2011.</p><p><b>RESULTS</b>Of the 91 cases, 53% were diagnosed empirically as bacterial otitis externa and 25% as otomycosis. Aerobic bacteria accounted for 35.8% of the microorganisms cultured, while 34.7% were fungi and 29.5% were anaerobic bacteria. Pseudomonas (P.) aeruginosa and Staphylococcus (S.) aureus made up 31.6% and 21.0% of the microorganisms, respectively. 20% of S. aureus grown was methicillin-resistant. Aspergillus was the most common fungus and 19% of cultures were polymicrobial. 38% of patients had their treatment changed on the basis of culture results, as no improvement was observed on follow-up. P. aeruginosa was sensitive to ciprofloxacin and gentamicin in 81.8% and 76.0% of patients, respectively, while S. aureus was sensitive to cloxacillin in 93.8% and clindamycin in 87.5% of patients.</p><p><b>CONCLUSION</b>The common microorganisms involved in otorrhoea in Singapore are P. aeruginosa, Aspergillus and S. aureus. Resistant strains of Pseudomonas spp. are now present. Methicillin-resistant S. aureus is increasingly prevalent and highly sensitive to vancomycin. Aminoglycoside and fluoroquinolone-containing eardrops are suitable first-line topical antimicrobials. Cloxacillin may be started should a concomitant oral antimicrobial be warranted empirically or for S. aureus infections. Otomycosis should be considered in patients who show no improvement with antibiotics.</p>