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Background The immunopathological mechanism for occupational asthma induced by toluene diisocyanate (TDI) remains to be further clarified. There have been few reports suggesting involvement of neutrophils in inducing bronchoconstriction after TDI inhalation. Objectives To further understand the role of neutrophils in the pathogenesis of TDI-induced asthma. Materials and methods Eight TDI-induced asthmatic subjects were classified as group I, and five exposed workers who had complained of work-related symptoms and worked in the same workplace, but showed negative bronchial challenges were enrolled as controls (group II). Serum neutrophil chemotactic activity during TDI bronchial challenge test was measured by the Boyden chamber method. Induced sputum was collected before and after the TDI bronchial challenge test. The myeloperoxidase (MPO) and interleukin (IL) -8 levels in the sputum were measured using RIA and ELISA. Result Serum neutrophil chemotactic activity significantly increased at 10 min (P = 0.01), then decreased at 60 min (P = 0.02) and remained unchanged for up to 420 min (P = 0.07) in group I subjects, while no significant changes were found in group II subjects (P > 0.05). MPO and IL-8 were abundantly present in the sputum of all the TDI-induced asthmatic subjects and they increased significantly at 420 min after the bronchial challenges (P = 0.02, P = 0.03, respectively), while no significant changes were noted in group II subjects (P > 0.05). Conclusion These findings support the view that activated neutrophils may contribute to bronchoconstriction induced by TDI which may be associated with IL-8 release.

Background The pathogenic mechanism of grain dust (GD)-induced occupational asthma (OA) remains unclear. Objective To understand further the mechanism of GD-induced OA. Methods Fifteen employees working in a same GD industry, complaining of work-related respiratory symptoms, were enrolled and were divided into two groups according to the GD-bronchoprovocation test (BPT) result: six positive responders were grouped as group III, nine negative responders as group II and five healthy controls as group I. Serum GD-specific immunoglobulin (Ig)E (sIgE), specific IgG (sIgG) and specific IgG4 (sIgG4) antibodies were detected by enzyme-linked immunosorbent assay. Basophil histamine release was measured by the autofluorometric method, and changes of serum neutrophil chemotactic activity were observed by the Boyden chamber method. Results For clinical parameters such as degree of airway hyperresponsiveness to methacholine, duration of respiratory symptoms, exposure duration, and prevalences of serum sIgE, sIgG and sIgG4 antibodies, there were no significant differences between group II and III (P > 0.05, respectively). Serum neutrophil chemotactic activity increased significantly at 30 min and decreased at 240 min after the GD-BPT in group III subjects (P 0.05). Basophil histamine release induced by GD was significantly higher in group III than those of group I or group II (P

Laying hens were fed a high polyunsaturated fatty acid (PUFA) diet with three levels [low (LPO, 0%), medium (MPO, 1.5%), and high (HPO, 3.5%)] of palm oil (PO) or a PUFA diet with tocopherol mix (control). Flax and fish oils were used as PUFA sources in all of the diets. Inclusion of tocopherols resulted in a lower (P < 0.05) thiobarbituric acid reactive substances (TBARS) in the control eggs in white and dark meats. Among the PO treatments, eggs from HPO diet had the lowest TBARS (P < 0.05). A higher (P < 0.05) TBARS was observed for eggs, meat, and liver from hens on the LPO diet. No difference was observed between the TBARS of LPO and MPO dark meat. The C22:6 n-3 fatty acid was lower (P < 0.05) in MPO and HPO eggs and the HPO white meat.