[Plastic bronchitis associated with severe influenza A (H1N1) in children: a case report and review of the literature].

OBJECTIVE: to improve understanding of the pathological and clinical features, diagnosis and treatment of plastic bronchitis associate with influenza A (H1N1). METHODS: one case of plastic bronchitis associated with influenza A (H1N1) diagnosed and treated in our hospital in January 2010 was reported and 19 cases of plastic bronchitis reported in the literature were reviewed. RESULTS: we describe a 5-year-old Chinese Japanese boy presenting with cough for 2 days, gasping and fever for 1 day was admitted. Left lung atelectasis and pneumothorax were found on chest X-ray examination. Pathologically, plastic bronchitis was diagnosed after the endogenous foreign body was extracted by bronchoscopy and classified as type 1 cast. In addition, influenza A (H1N1) was confirmed by the swabs which showed positive for H1N1 nucleic acid. The condition was controlled and the patient was cured and discharged after 16-days' treatment with antiviral therapy, low-dose corticosteroids, and antibiotics. CONCLUSION: plastic bronchitis associated with influenza A (H1N1) is a rare life-threatening disorder. The diagnosis could be made based on pathological findings of the bronchial casts as well as the positive H1N1 nucleic acid detection. Bronchoscopic extraction of casts in plastic bronchitis is not only useful for early diagnosis but an effective therapeutic modality for the disease. Influenza A (H1N1) may be a cause of plastic bronchitis.

Antibacterial activity and mechanism of silver nanoparticles on Escherichia coli.

The antibacterial activity and acting mechanism of silver nanoparticles (SNPs) on Escherichia coli ATCC 8739 were investigated in this study by analyzing the growth, permeability, and morphology of the bacterial cells following treatment with SNPs. The experimental results indicated 10 microg/ml SNPs could completely inhibit the growth of 10(7) cfu/ml E. coli cells in liquid Mueller-Hinton medium. Meanwhile, SNPs resulted in the leakage of reducing sugars and proteins and induced the respiratory chain dehydrogenases into inactive state, suggesting that SNPs were able to destroy the permeability of the bacterial membranes. When the cells of E. coli were exposed to 50 microg/ml SNPs, many pits and gaps were observed in bacterial cells by transmission electron microscopy and scanning electron microscopy, and the cell membrane was fragmentary, indicating the bacterial cells were damaged severely. After being exposed to 10 microg/ml SNPs, the membrane vesicles were dissolved and dispersed, and their membrane components became disorganized and scattered from their original ordered and close arrangement based on TEM observation. In conclusion, the combined results suggested that SNPs may damage the structure of bacterial cell membrane and depress the activity of some membranous enzymes, which cause E. coli bacteria to die eventually.