Nerve growth factor induces increased airway inflammation via a neuropeptide-dependent mechanism in a transgenic animal model of allergic airway inflammation.

BACKGROUND: Nerve growth factor (NGF) exerts an important functional impact on the pathogenesis of allergic diseases. Data obtained in animal models of allergic bronchial asthma indicate that NGF alters sensory nerve function and promotes allergic inflammation, bronchial hyper-reactivity, and airway obstruction. OBJECTIVE: To further delineate the effects of NGF on airway inflammation, we employed a transgenic (tg) animal model of allergic inflammation and asthma. METHODS: NGF-tg mice, which overexpress NGF in Clara cells of the airways, were compared with wild-type (wt) littermates regarding their ability to mount IgE-related airway inflammatory responses. Mice were sensitized intraperitoneally to ovalbumin (OVA) and locally challenged via the airways according to established protocols. RESULTS: NGF-tg mice displayed enhanced levels of OVA-specific IgE antibody titres after repeated OVA aerosol exposure. In the airways, increased numbers of eosinophils were detected. These results were confirmed to be NGF specific, because similar results were obtained following local application of NGF into the airways of wt mice. The effect of NGF was partly mediated via neuropeptides, as treatment of OVA-sensitized NGF-tg mice with the dual neurokinin (NK) receptor NK-1/NK-2 antagonist partly prevented enhanced airway inflammation. CONCLUSION: The present data indicate an important functional role of NGF in allergic airway inflammation and point to an involvement of tachykinins as mediators of NGF effects.

Antioxidative enzymes in human nasal mucosa after exposure to ozone. Possible role of GSTM1 deficiency.

OBJECTIVE AND DESIGN: Epithelial antioxidative enzymes (AOEs) are thought to be a first line of defense against reactive oxygen species as they are upregulated after exposure to ozone according to animal studies. We analysed the activities of the AOEs catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), superoxide dismutase (SOD) and glutathione-S-transferase (GST) in a tissue culture of human nasal mucosa and analysed the influence of GSTM1 polymorphism on AOE regulation. METHODS: Tissue biopsies of 20 subjects were incubated for 24 h with and without 120 ppb ozone. Activities were assayed to determine what enzymatic changes had taken place, both overall and in regard to GSTM1 status. RESULTS: Activities for GPX (p = 0.272) and SOD (p = 0.291) were found increased after ozone exposure. GSTM1-deficient patients showed a significantly enhanced upregulation of SOD activity (p = 0.011) compared to GSTM1 carriers. CONCLUSION: Our findings suggest that GSTM1-deficiency has an impact on AOE-regulation after ozone exposure.

Substance P induced histamine release from nasal mucosa of subjects with and without allergic rhinitis.

OBJECTIVE AND DESIGN: There is evidence that substance P (SP) is involved in events related to allergic and nonallergic rhinitis. Furthermore, some effects of SP seem to be greater in subjects suffering from allergic rhinitis than in nonallergic subjects. To investigate if these effects may be partly mediated by histamine release (HR) we studied the influence of SP on HR from nasal mucosa of subjects with and without allergic rhinitis using an in vitro organ culture system. SUBJECTS: Nasal mucosa of the inferior turbinate was obtained from ten patients suffering from allergic rhinitis and eighteen non-allergic subjects receiving surgical therapy for nasal obstruction. METHODS: Tissue samples of nasal mucosa were stimulated with 10(-5) M SP or with 10(-5) M Ca-ionophore A23187 for 120 minutes, and the histamine content was determined in the culture supernatant. RESULTS: Both SP and Ca-ionophore A23187, caused a significantly higher HR from the samples of the non-allergic group (p < 0.01) compared to baseline controls (spontaneous release). The same effect was seen in the allergic group (p < 0.01 and p = 0.036). Comparing the increase in HR from allergic and non-allergic mucosa, in allergics the HR stimulated by SP was significantly higher (p = 0.031), whereas Ca-ionophore A23187 did not show this effect. CONCLUSION: These findings suggest a role of SP in inducing release of histamine from human nasal mucosa, thereby influencing physiologic and pathophysiologic nasal conditions, especially in allergic inflammatory processes.

Influence of ozone and nitrogen dioxide on histamine and interleukin formation in a human nasal mucosa culture system.

There is evidence that asthma and other allergic diseases are increasing and air pollution has been considered an important contributing factor to this observation. Using a specially designed organ culture system, we examined the influence of ozone (0.06 to 0. 2 ppm) and nitrogen dioxide (NO2, 200 and 800 micrograms/m3) on nasal mucosa exposed for 24 h. Tissue was obtained from 105 patients undergoing surgical therapy (septoplasty and reduction of the inferior turbinates) for chronic nasal obstruction. The histamine content in the culture medium of ozone- and NO2-exposed samples was significantly elevated compared with the control cultures. This elevation was correlated with the number of degranulated mast cells in the tissue determined by histomorphometry (P < 0.001). Moreover, the cytokines interleukin (IL)-1beta (P < 0.05), IL-6 (P < 0.01), IL-8 (P < 0.001), and tumor necrosis factor-alpha (TNF-alpha, P < 0. 001) were significantly increased (ozone 0.1 ppm). Furthermore, we found significant increases in the release of IL-4, IL-6, IL-8, and TNF-alpha of ozone-exposed (0.1 ppm) samples of atopic versus nonatopic patients and to a lesser extent for histamine following exposure to 0.15 ppm ozone. These results indicate that low ozone concentrations and NO2 lead to an inflammation of human nasal mucosa in vitro and that priming factors such as atopy or preexisting inflammation do increase the sensitivity to ozone and NO2. This organ culture system proved to be a good experimental design for studying pathophysiologic alterations of human nasal mucosa under different experimental conditions (e.g., air pollutants).

Ozone-induced augmentation of eicosanoid metabolism in human nasal mucosa in vitro.

The increase in airway responsiveness induced by ozone exposure is associated with airway inflammation as evidenced by an increase in inflammatory mediators such as cyclooxygenase and lipoxygenase product formation found in bronchoalveolar lavage fluid, nasal lavage fluid and epithelial cell cultures. To examine eicosanoid metabolism after exposure to ozone, human nasal mucosa derived from 21 patients undergoing surgical therapy for chronic nasal obstruction was cultured with a specially designed in vitro organ culture device and exposed to 0.1 ppm ozone for 24 h. Eicosanoid formation was analyzed by the release of cyclooxygenase and lipoxygenase products into the culture supernatant (measured by enzyme immunoassay). Experiments revealed ozone-induced increases in cyclooxygenase and lipoxygenase product formation with significant increases in prostaglandin F2alpha (PGF2alpha), thromboxane B2 (TXB2) and leukotriene B4 (LTB4) (p<0.05). Moreover, we found an increase in the concentration of LTC4/D4/E4 in the supernatant of ozone-exposed mucosal samples, which however does not reach statistical significance. There was a significant correlation between PGF2alpha and TXB2 (r = 0.71, p<0.001). These results extend previous results from in vivo chamber studies suggesting that the mode of action of ozone is an oxidative reaction resulting in an increased activity of arachidonic acid metabolism in the airways with a subsequent increase in the concentration of cyclooxygenase and lipoxygenase products.

Substance-P-induced histamine release from human nasal mucosa in vitro.

There is growing evidence that substance P (SP) is one of the main neuropeptides involved in neurogenic inflammation of the airways. However, a number of studies were not able to demonstrate histamine release from human mucosal mast cells after SP administration. Since cultures of isolated cell systems provide only a partial picture of the inflammatory processes in vivo, organ culture models promise to offer physiologically relevant assay systems for studying tissue interactions. Thus, we examined the influence of SP on histamine release and its morphological effects on human nasal mucosa using a previously described histoculture technique. Compared to controls, the histamine content in the culture bath was significantly elevated after SP stimulation (p < 0.05). Histomorphometry showed a decreased density of mast cells and an increased percentage of degranulated mast cells. These findings were dose and time dependent and support the hypothesis of a close interaction between C-sensory nerves and mast cells implying that these interactions are of pathogenetic importance in nasal mucosa inflammation.

Gelatin sponge-supported histoculture of human nasal mucosa.

Considerable progress has recently been made in the understanding of airway inflammation by cell culture assays and in vivo provocation studies. Inasmuch as ethical considerations limit experimental work in humans, physiologically relevant in vitro models are required to better understand cellular and molecular tissue interactions in human nasal mucosa. Here we describe a human nasal mucosa culture model utilizing a simple gelatin sponge-supported histoculture system at the air-liquid interface. Viable mucosa was preserved for at least 48 h, as shown by morphology and immunohistochemical staining with Ki-67 as marker for proliferation. Pro-inflammatory mediators (kinins, histamine, thromboxane B2, prostaglandin F2 alpha, and substance P) are detectable in serum-containing as well as serum-free culture medium. Incubation with 10(-8) M substance P increases the number of degranulated mast cells after 48 h by 26% (P < 0.01). In this model, biochemical responses can be correlated with histologic alterations of the target tissue. Inflammatory parameters can be examined and compared in various patient groups and different stimulators/inhibitors. This culture method provides a valuable research tool for analyzing all compartments present in nasal mucosa under physiologically relevant conditions, and for studying complex interactions and responses of mucosal cell populations in their natural tissue environment.

[Contributions to the parasite fauna of local hosts. 10. On the endoparasitic fauna of Felis silvestris]. / Beiträge zur Parasitenfauna autochthoner Wirte 10. Mitteilung: Zur Endoparasitenfauna von Felis silvestris.

The investigations based on examination of the internal organs of 25 wild cats of the Harz population died from different causes in the period from 1982 to 1989. 22 animals (= 88%) were positive for parasites. The following species were found: Hydatigera taeniaeformis, Taenia crassiceps, T. martis larv. (spurious parasite), Mesocestoides litteratus, Capillaria plica, Capillaria sp. (aerophila?), Toxocara mystax, Cystoisopora felis. Toxocara mystax and Hydatigera taeniaeformis were the most often diagnosed helminths. Their number ranged up to 247 and 30 specimen respectively. The stated parasite fauna is comparable with findings in run wild domestic cats in rural areas. Voles contained in the stomach content of most of the cats play a role in the epizootiology of wild cat endoparasites.

[The parasite fauna of East Germany. 9. The helminth fauna of Lutra lutra]. / Beiträge zur Parasitenfauna der DDR. 9. Mitteilung: Zur Helminthenfauna von Lutra lutra.

Alimentary tract, liver, kidneys and lungs of 25 otters, died of several causes during 1982-1987 in GDR were included in helminthological investigations. Parasites were detected in 8 animals. One cestode: Taenia martis and 3 trematodes: Isthmiophora melis, Opisthorchis felineus and Pseudamphistomum truncatum are regarded to be certain parasites of this host. Other findings like Ligula intestinalis, Azygia luccii and Piscicola geometra and the fragment of a pseudophyllidean enter the alimentary tract with the food and pass through it.