The ferret is an established animal model of influenza virus infection. Although viral replication in the upper respiratory tract is usually measured with consecutively collected nasal washes, daily evaluation of viral replication in the lung is limited because a large numbers of ferrets need to be sacrificed at consecutive time points. To overcome this limitation, we performed a virus quantification assay using bronchoalveolar lavage (BAL) fluid. This non-invasive BAL technique allows consecutive quantification of virus replication in the lungs of living ferrets. Our method can be used for the longitudinal evaluation of virus tropism in the lower respiratory tract.
Animals ; Bronchoalveolar Lavage/*veterinary ; Disease Models, Animal ; Female ; Ferrets/*virology ; Influenza A Virus, H3N2 Subtype/*physiology ; Orthomyxoviridae Infections/*veterinary/virology ; Respiratory System/*virology ; Virus Replication/*physiology

OBJECTIVETo investigate the pharmacological effect of Nyctanthes arbortristis (NAT) leaf extract in the prevention of lung injury induced by silica particles.

METHODLung injury was induced in Swiss mice through inhalation exposure to silica particles (< 5 mu) using a Flow Past Nose Only Inhalation Chamber at the rate of -10 mg/m3 respirable mass for 5 h. Lung bronchoalveolar lavage (BAL) fluid collected between 48 and 72 h was subjected to protein profiling by electrophoresis and cytokine evaluation by solid phase sandwich ELISA. Lung histopathology was performed to evaluate lung injury.

RESULTSInhalation of silica increased the level of tumor necrosis factor-alpha (TNF-alpha), and of the 66 and 63 kDa peptides in the BAL fluid in comparison to sham-treated control. Pre-treatment of silica exposed mice with NAT leaf extract significantly prevented the accumulation of TNF-alpha in the BAL fluid, but the 66 and 63 kDa peptides remained unchanged. The extract was also effective in the prevention of silica-induced early fibrogenic reactions like congestion, edema and infiltration of nucleated cells in the interstitial alveolar spaces, and thickening of alveolar septa in mouse lung.

CONCLUSIONNAT leaf extract helps in bypassing silica induced initial lung injury in mice.

Administration, Oral ; Animals ; Bronchoalveolar Lavage Fluid ; Disease Models, Animal ; Enzyme-Linked Immunosorbent Assay ; Inhalation Exposure ; Male ; Mice ; Oleaceae ; chemistry ; Phytotherapy ; Plant Extracts ; pharmacology ; Pulmonary Fibrosis ; etiology ; prevention & control ; veterinary ; Silicon Dioxide ; adverse effects ; Silicosis ; prevention & control ; veterinary

BACKGROUND: BCG, a potent inducer of Th1 immune response, has been suggested to suppress Th2 response which is known to mediate IgE-mediated allergic disorders, in particular allergic asthma. Schultz-Dale reaction is known to be a model of IgE-mediated hypersensitivity. This study was done to investigate whether BCG infection suppresses the Schultz-Dale reaction by inhibiting Th2 response and allergen-specific IgE production. METHODS: Twenty-four Sprague-Dawley rats were sensitized and provoked with ovalbumin (OVA). A pretreatment of 6 x 10(4) colony forming units of BCG or saline was done 7 days before sensitization. The Schultz-Dale reaction was represented as tracheal smooth muscle contractions to 50 micrograms/mL OVA challenge in vitro. Serum OVA-specific IgE levels and IFN-gamma and IL-4 concentrations in bronchoalveolar lavage fluid (BALF) were measured. RESULTS: The Schultz-Dale reaction and serum OVA-specific IgE levels were significantly decreased in BCG infected and OVA sensitized rats compared with only sensitized rats (p < 0.01 and p < 0.05, respectively). As compared with only sensitized rats, IL-4 concentration and a ratio of IFN-gamma:IL-4 in BCG infected and OVA sensitized rats were significantly decreased (p < 0.001) and increased (p < 0.05), respectively. The Schultz-Dale reaction was correlated with OVA-specific IgE levels (r = 0.50, p < 0.05), IL-4 concentration (r = 0.69, p < 0.001), and ratio of IFN-:IL-4 (r = -0.44, p < 0.05). OVA-specific IgE levels were correlated with IL-4 concentration (r = 0.61, p < 0.01) and ratio of IFN-gamma:IL-4 (r = -0.48, p < 0.05). CONCLUSION: These findings suggest that BCG infection prior to allergen sensitization may inhibit Schultz-Dale reaction developed in the sensitized rat tracheal smooth muscle via the suppressive effects of Th2 immune response and allergen-specific IgE production.
Animal ; Bronchial Provocation Tests ; Bronchoalveolar Lavage Fluid/*chemistry ; Comparative Study ; Cytokines/analysis ; Disease Models, Animal ; Hypersensitivity, Immediate/*immunology ; Immunization ; Immunoglobulin E/*analysis ; Male ; Mycobacterium bovis/*immunology ; Probability ; Rats ; Rats, Sprague-Dawley ; Reference Values ; Sensitivity and Specificity ; T-Lymphocytes/*immunology ; Tuberculosis/*immunology/veterinary