The development of a serological marker for early diagnosis of isocyanate-induced occupational asthma (isocyanate-OA) may improve clinical outcome. Our previous proteomic study found that expression of vitamin D-binding protein (VDBP) was upregulated in the patients with isocyanate-OA. In the present study, we evaluated the clinical relevance of VDBP as a serological marker in screening for isocyanate-OA among exposed workers and its role in the pathogenesis of isocyanate-OA. Three study groups including 61 patients with isocyanate-OA (group I), 180 asymptomatic exposed controls (AECs, group II), 58 unexposed healthy controls (NCs, group III) were enrolled in this study. The baseline serum VDBP level was significantly higher in group I compared with groups II and III. The sensitivity and specificity for predicting the phenotype of isocyanate-OA with VDBP were 69% and 81%, respectively. The group I subjects with high VDBP (> or = 311 microg/ml) had significantly lower PC20 methacholine levels than did subjects with low VDBP. The in vitro studies showed that TDI suppressed the uptake of VDBP into RLE-6TN cells, which was mediated by the downregulation of megalin, an endocytic receptor of the 25-hydroxycholecalciferol-VDBP complex. Furthermore, toluene diisocyanate (TDI) increased VEGF production and secretion from this epithelial cells by suppression of 1,25-dihydroxycholecalciferol [1,25(OH)2D3] production. The findings of this study suggest that the serum VDBP level may be used as a serological marker for the detection of isocyanate-OA among workers exposed to isocyanate. The TDI-induced VEGF production/secretion was reversed by 1,25(OH)2D3 treatment, which may provide a potential therapeutic strategy for patients with isocyanate-OA.
Adult ; Animals ; *Asthma/blood/chemically induced/pathology ; Cell Line ; Epithelial Cells ; Female ; Gene Expression/drug effects ; Humans ; Isocyanates/toxicity ; Male ; Middle Aged ; *Occupational Diseases/blood/chemically induced/pathology ; Rats ; Toluene 2,4-Diisocyanate/toxicity ; Vitamin D-Binding Protein/*blood

OBJECTIVETo study the anti-asthmatic effect of sodium ferulate (SF) and its mechanism in guinea pig asthmatic model.

METHODSGuinea pigs were sensitized with ovalbumin as animal asthmatic model and treated with 3 different concentration of SF for 8 days. Levels of endothelin (ET) and nitric oxide (NO) in blood and lung tissue, and eosinophil (EOS) in blood and bronchoalveolar lavage fluid (BLAF) was counted at the end of trial.

RESULTSSF could significantly lower the ET content and increase the NO concentration in serum and lung tissue, reduce the number of EOS in blood and BLAF (P < 0.05, P < 0.01). Stronger effect was showed in the high dose group.

CONCLUSIONMechanism of anti-asthmatic action of SF might be to increase NO concentration, lower ET content, alleviate EOS infiltration.

Animals ; Anti-Asthmatic Agents ; pharmacology ; Asthma ; blood ; chemically induced ; Bronchoalveolar Lavage Fluid ; cytology ; Coumaric Acids ; pharmacology ; Endothelin-1 ; blood ; Eosinophils ; pathology ; Female ; Guinea Pigs ; Male ; Nitric Oxide ; blood ; Ovalbumin

OBJECTIVEEosinophilic airway inflammation is one of the basic characteristics of allergic asthma. Toll-like receptor is one of the most important innate immunity pattern recognition receptors. Glucocorticoids (GCS) are still the most effective treatment for asthma. However, few reports of studies on regulatory mechanism of GCS on the innate immunity system are available. The mechanism of effects of GCS on TLR4 is unclear. The present study aimed at understanding the effect of dexamethasone (DXM) on change of TLR4 and mechanism of regulatory effect of TLR4 on eosinophil (EOS) apoptosis.

METHODSTwenty-seven Sprague-Dawley (SD) rats (age 28 to 42 days, body weight 120 to 180 gram) were randomly divided into the control group, asthma group and DXM group with 9 in each. Asthma model rats were sensitized with the mixture of ovalbumin (OVA, 1 mg) and Al (OH)(3), 100 mg on day 1 and day 8, repeatedly exposed to aerosolized OVA after day 15, once a day for three days and continued for 30 minutes at every time. During the sensitization stage, 100 microg/ml DXM were prepared with DXM group for every other day, and the same doses DXM were prepared for every day on the stage of challenge. The histopathological changes of lung tissues were observed with light microscope (LM). EOS and other inflammatory cells in bronchoalveolar lavage fluid (BALF) were counted; the concentrations of OVA-sIgE in serum were measured by using "sandwich" ELISA; The expressions of TLR4 mRNA were determined by in situ hybridization, the apoptosis of EOS was detected by TUNEL.

RESULTS(1) LM showed many inflammatory cells infiltration around the bronchi and blood vessels, bronchus mucus increased, airway epithelium damage and desquamation, and airway mucous plugs in asthma group, whereas DXM group showed significantly milder changes. (2) Inflammationary cells count in BALF of asthma group was significantly higher as compared to control group (P < 0.01); compared with asthma group, the total cell count, EOS absolute count and EOS% were all significantly decreased in DXM group [(2.14 +/- 0.10) x 10(9)/L, (4.78 +/- 1.23) x 10(7)/L, (2.17 +/- 0.25)%]. (3) Levels of OVA-sIgE in serum of asthma group [(83.40 +/- 6.80) microg/ml] were significantly higher than those of the control group [(14.38 +/- 4.25) microg/ml] (P < 0.01), while those of DXM group [(45.02 +/- 7.47) microg/ml] were significantly lower than asthma group (P < 0.0 1). (4) There were no significant differences in TLR4 mRNA detected by in situ hybridization between control group (24.71 +/- 0.85) and asthma group (25.81 +/- 3.56) (P > 0.05); but it significantly increased in DXM group (29.86 +/- 3.92) as compared to asthma group. (5) The percentages of apoptotic EOS in asthma group [(7.39 +/- 1.93)%] were significantly lower than those in control group [(9.06 +/- 1.52)%] (P < 0.01); and significantly higher in DXM group [(13.33 +/- 1.09)%] than in asthma group (P < 0.01). There were significantly positive correlations between TLR4 mRNA and the percentage of apoptotic EOS (r = 0.612, P < 0.01).

CONCLUSIONDXM can decrease OVA-sIgE level, induce EOS apoptosis, which may correlate with the activation of TLR4 signal transduction.

Animals ; Apoptosis ; Asthma ; chemically induced ; immunology ; Bronchoalveolar Lavage Fluid ; cytology ; Dexamethasone ; pharmacology ; Eosinophils ; immunology ; Glucocorticoids ; pharmacology ; Immunoglobulin E ; blood ; Lung ; pathology ; Ovalbumin ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; drug effects ; Toll-Like Receptor 4 ; immunology ; metabolism

AIMTo evaluate the effect of interleukin-1 receptor antagonist(IL-1ra) on apoptosis and associated mechanism of eosinophil in guinea pig with asthma.

METHODSA model of guinea pig with asthma was established. After inhalation of different concentrations of IL-1ra, asthma was induced in the guinea pig for 8 days, the concentration of eosinophil cationic protein (ECP) in serum and bronchoalveolar lavage fluid (BALF), IL-5 in serum, the eosinophil counts and apoptosis were assayed by radioimmunology, enzyme-linked immunosorbent assay(ELISA), fluoromicroscope and light microscope.

RESULTSIL-1ra indirectly decreased the level of IL-5 in serum, improved the apoptosis of eosinophil(EOS) in lung, then decreased the level of ECP in serum and BALF.

CONCLUSIONInhalation of nebulized IL-1ra showed protective effect against asthma through change of the activity and infiltration of EOS in lung.

Animals ; Apoptosis ; Asthma ; blood ; chemically induced ; pathology ; Blood Proteins ; metabolism ; Bronchoalveolar Lavage Fluid ; chemistry ; Eosinophil Granule Proteins ; Eosinophils ; drug effects ; pathology ; Female ; Guinea Pigs ; Interleukin 1 Receptor Antagonist Protein ; Interleukin-5 ; blood ; Leukocyte Count ; Male ; Ovalbumin ; Random Allocation ; Receptors, Interleukin-1 ; antagonists & inhibitors ; Ribonucleases ; blood ; metabolism ; Sialoglycoproteins ; pharmacology

This study is to establish a rat chronic asthma model. Sensitive SD rats were selected through histamine challenge. The asthmatic groups were sensitized by ih and ip with OVA, aluminium hydroxide gel and inactivated bacillus pertussis on day 1 and 14. From day 21, acute asthmatic group was aerosolized 1% OVA for 1 week, chronic asthmatic group was aerosolized 0.1% OVA for 12 weeks. The control groups received saline as the substitution of OVA. Twenty four hours after the last provocation, physiological monitoring equipment was used to detect the pulmonary function, then the rats were sacrificed. Bronchoalveolar lavage fluid (BALF) was collected to calculate the ratio of different inflammatory cells. ELISA was used to detect total IgE and OVA-specific IgE in serum. Microscopy was conducted to observe the histopathology of lung stained with haematoxylin and eosin staining. Collagen fibers were detected using Picric acid-Sirius red staining technique. The optical density at 610 nm of extractive from locus caeruleus was detected by passive cutaneous anaphylaxis (PCA). The results showed that the asthmatic characteristics were significantly developed in model groups, but not in control groups. Chronic asthmatic group had significantly higher indexes than acute asthmatic group, including the thickness of airway smooth muscle and bronchial basement membrane, and goblet cell hyperplasia, the area of collagen in airways, A610 of extractive from locus caeruleus, the concentration of total IgE and OVA-specific IgE in serum. However, inflammatory cell infiltrate in lungs and the percentage of eosinophils of white blood cells in BALF were lower in chronic asthmatic group than those in acute asthmatic group. Respiratory rate and respiratory flow showed no significant difference in both model groups. In conclusion, the rat chronic asthma model is established by the way in this study, which is comparable to the physiopathologic characteristics of human asthma.
Airway Remodeling ; Animals ; Asthma ; blood ; chemically induced ; pathology ; physiopathology ; Bronchoalveolar Lavage Fluid ; cytology ; Chronic Disease ; Disease Models, Animal ; Eosinophils ; pathology ; Female ; Immunoglobulin E ; blood ; Leukocyte Count ; Lung ; pathology ; Ovalbumin ; immunology ; Passive Cutaneous Anaphylaxis ; Pulmonary Ventilation ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Respiratory Rate

OBJECTIVETo investigate the effect of nebulized total ginkgo flavone glycosides (TFG) on Th1/Th2 imbalance in mice with athma.

METHODForty-eight BALB/C mice were randomly divided into four groups: group A (control group, n=12); group B (asthmatic model group, n=12); group C (TFG nebulized treated group, n=12); group D (dexamethasone intraperitoneal treated group, n=12). The asthmatic model was established by sensitivity and local activation with Ovalbumin(OVA) and aluminum hydroxide Al(OH)3. TFG (50 g x L(-1), per aerosol per six mice, 30 minutes) was nebulized 20 days after modeling, while dexamethasone (1 g x L(-1)) was intraperitoneal once daily for 10 days. Perfusate of bronchoalveolar lavage fluid(BALF) was collected on day 32. The level of IL-4, IFN-gamma in BALF, and the level of total IgE in serum was determined. The airway inflammation pathology change and the expression of GATA-3 protein in lungs was detected by immunohistochemical staining.

RESULTCompared with model group, the decreased content of IL-4(49.30 +/- 7.95) ng x L(-1) and increased level of IFN-gamma (49.08 x 5.46) ng x L(-1). were found in BALF, and the level of total IgE (9.47 +/- 1.52) microg x L(-1) in serum also decreased in TFG treated group. In model group, smooth muscle hypertrophing, mucous hyperemia, mucous layer thickening, and inflammatory cell in filtration were observed. Phlegmasia was appeared in the bronchi, which was filled with lots of mucus. In contrast, the inflammatory reaction in TFG and Dexamethasone treated group was less obvious. Expression of GATA-3 was markly increased in model group with decreased expression in TFG treated group.

CONCLUSIONNebulized TFG showed a therapeutic effect for asthmatic mice, the mechanism may be explained by blockingnnnn GATA-3 expression and regulating the disorder Th1/Th2 imbalance.

Aluminum Hydroxide ; pharmacology ; Animals ; Asthma ; chemically induced ; drug therapy ; metabolism ; pathology ; Bronchoalveolar Lavage Fluid ; chemistry ; Dexamethasone ; therapeutic use ; Drugs, Chinese Herbal ; chemistry ; therapeutic use ; Female ; Flavones ; Flavonoids ; chemistry ; GATA3 Transcription Factor ; metabolism ; Ginkgo biloba ; chemistry ; Glycosides ; chemistry ; therapeutic use ; Immunoglobulin E ; blood ; Interferon-gamma ; metabolism ; Interleukin-4 ; metabolism ; Lung ; drug effects ; metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Ovalbumin ; pharmacology ; Random Allocation ; Th1 Cells ; drug effects ; metabolism ; Th2 Cells ; drug effects ; metabolism