Virus-induced airway hyperresponsiveness in guinea pigs in vivo: study of broncho-alveolar cell number and activity.

Recently, we demonstrated that an increased airway responsiveness in vitro can be measured 4, 8, and 16 days, but not 2 days, after intratracheal inoculation of parainfluenza-3 (PI-3) virus to guinea pigs. In the present study airway responsiveness was measured in vivo, and the number, types and activity of broncho-alveolar cells was determined. A significant increase in airflow resistance was measured in spontaneously breathing anesthetized guinea pigs in response to histamine and methacholine, 4 and 8 days after PI-3 virus inoculation. 2 days after inoculation with control solution or PI-3 virus, no difference in the total number of inflammatory cells was observed in the broncho-alveolar lavage fluid. In contrast, on days 4, 8, and 16 after infection a significant increase in the number of alveolar macrophages (102%, 76%, 68%, respectively), monocytes (552%, 374%, 360%, respectively), and lymphocytes (253%, 675%, 396%, respectively) was found. The number of eosinophils was increased as well, but faded with time (378%, 312%, 63%, respectively). PI-3 virus was found to be a very potent activator of broncho-alveolar cells as measured by chemiluminescence. The increase in chemiluminescence production in response to PI-3 virus was reduced in cells obtained from PI-3 virus pretreated animals (day 2, 42%; day 4, 65%; day 8, 22%; and day 16, 30%). In conclusion, PI-3 virus can stimulate broncho-alveolar cells and the virus-induced airway hyperresponsiveness is associated with an influx of inflammatory cells in the respiratory tract.     

KGF-transfected cells can stimulate growth and proliferation of human cultured keratinocytes in vitro

Objective: To establish two stably KGF-transfected, immortalized cell lines. Methods: HaCaT-keratinocytes and KMST-6-fibroblasts were transfected by liposome mediated gene transfer. Transfection effectivity, gene integration and configuration of the transgenic protein were investigated by ELISA, DANN-PCR and β-Gal-staining. Results: Most effective GF producing clones were tested by a colorimetric XTT-test. Conclusion: This is a significant acceleration of cell proliferation and mitosis of human keratinocytes in an Air Liquid Interface (ALI) test system.     

Involvement of catecholamines in haemophilus influenzae induced decrease of β-adrenoceptor function

Summary The deeper airways of patients with asthmatic bronchitis are often infected with Haemophilus influenzae. Vaccination of guinea pigs with H. influenzae resulted in a significant impairment of the isoproterenol induced relaxation of isolated tracheal spirals by approximately 50% 4 days following vaccination. In the present study we further investigated the effects of some drugs affecting catecholamine release on the H. influenzae induced functional desensitization of tracheal spirals. Benserazide, an inhibitor of dopadecarboxylase, completely prevented the reduction in isoproterenol-induced relaxation after H. influenzae vaccination, while no effect on relaxation of tracheal spirals from control animals was detected. On the other hand, inhibiting the re-uptake of catecholamines with desipramine did not influence the relaxation in the H. influenzae vaccinated treacheal spirals. Treatment of control animals with desipramine however resulted in a decreased relaxation of the isolated spirals by 40%. One day following vaccination with H. influenzae the level of norepinephrine in lung tissue was significantly elevated by 71%, and in plasma by 77%, while after 4 days no significant effects were observed. The spontaneous release of norepinephrine, epinephrine and dopamine of tracheal incubates was increased at days 1 and 4 following vaccination. The release of catecholamines from minced lung incubates of H. influenzae pretreated guinea pigs did not differ from that of controls.On the basis of these results it may be suggested that catecholamine metabolism is changed in lungs from H. influenzae vaccinated animals. Catecholamines, accordingly may play a role in the desensitization of -adrenoceptors by H. influenzae.