The air pollutant sodium sulfite enhances mite crude extract-stimulated detachment of A549 airway epithelium cells.

BACKGROUND AND PURPOSE: It has been previously reported that the pollutant sodium sulfite (Na2SO3) can activate airway epithelial cells; however, there is as yet no evidence of any direct relationship between house dust mite allergen exposure and Na2SO3 with regards to the pathogenesis of airway allergy. This study investigated the effect of sulfite on mite-stimulated human airway epithelial cells. METHODS: The A549 human lung epithelial cell line was used as an in vitro model. Cells were treated with 10 microg/mL mite crude extract for 8 h and/or Na2SO3 (0, 10, 100, 500, 1000 and 5000 microM) for 16 h, and cell adhesion and dissociation on a cell culture plastic surface were quantitated with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay. Changes in cell adhesion were also analyzed by monitoring the expression of the cell surface of adhesion molecules integrin alpha2 (CD49b) and integrin alpha6 (CD49f) using flow cytometry. RESULTS: A549 cells treated with either mite crude extract only or Na2SO3 only did not show a significant increase in dissociation from the cell culture plastic surface. However, when cells were pretreated with mite extract for 8 h, followed by 16-h incubation with various concentrations of Na2SO3, cell dissociation was enhanced in a dose-dependent manner. A dose-dependent decrease of CD49b and CD49f expression was also seen in cells treated with Na2SO3 only and in mite-pretreated cells. Mite treatment decreased CD49b expression, and a cumulative effect was seen in cells further treated with Na2SO3. CONCLUSION: Significant dissociation of airway epithelial cells with Na2SO3 stimulation only occurred in cells pretreated with mite extract. Mite pretreatment enhanced Na2SO3-induced CD49f down-regulation; Na2SO3 and/or mite extract down-regulated CD49b expression of A549 cells. These findings indicate that a synergistic effect of mite extract and sulfite can severely disrupt the airway bronchial epithelial barrier.

Prevalence of atopy in children with type 1 diabetes mellitus in central Taiwan.

BACKGROUND AND PURPOSE: Atopic diseases, including asthma, eczema and allergic rhinitis, are characterized by a chronic inflammatory reaction mediated by T helper 2 (Th2) cells, while type 1 diabetes mellitus (T1D) is mediated by T helper 1 (Th1) cells. The 'balance' between Th1 and Th2 cells appears to be vitally important. Hence, it is a plausible hypothesis that the prevalence in Th2-mediated disease would be lower in patients with Th1-mediated disease. The aim of this study was to compare the prevalence of atopic diseases between children with T1D and age-matched controls, and investigate possible factors that influence the prevalence of atopic disease. METHODS: Parents of children with T1D in Taichung Veterans General Hospital were requested by pediatricians to complete the International Study of Asthma and Allergies in Childhood questionnaire on the prevalence of atopic diseases. Responses were compared with an age-matched control group. RESULTS: Questionnaires were evaluated from 100 T1D patients and 194 controls. After age-matching, the questionnaires of 54 T1D patients were included. Symptoms of asthma, allergic rhinitis and eczema were reported less often in the group of children with T1D compared with the control group (wheeze with exercise, p=0.044; nasal symptoms with itching eyes in the past 12 months, p=0.048; nasal allergy ever, p=0.038; skin rash in the past 12 months, p=0.044). In addition, the proportion of T1D patients with any asthmatic symptom (such as wheezing once in life, wheezing in the past 12 months, wheezing with exercise and dry cough at night in the past 12 months) was significantly lower than in controls (20.4% vs 36.6%, p=0.036). CONCLUSIONS: These results indicate that patients with T1D have a lower prevalence of atopic symptoms, especially asthma, which is consistent with the Th1/Th2 polarization concept. Environmental factors are another direct influence on the development of atopy in T1D patients.

Comparison of the effects of two long-acting beta2-agonists on cytokine secretion by human airway epithelial cells.

BACKGROUND AND PURPOSE: Long-acting beta2-agonists (LABAs) have proved to be useful in the management of asthma and prevention of exacerbations. LABAs can modulate inflammatory and repair processes in the airways of individuals affected by many respiratory disorders. This study assessed the effects of LABAs on the release of inflammatory mediators by bronchial epithelia. METHODS: The effects of the LABAs salmeterol and formoterol on the synthesis of soluble interleukin-8 (IL-8), granulocyte-macrophage colony-stimulating factor (GM-CSF), and vascular endothelial growth factor (VEGF) in the human airway epithelial cell line A549 was investigated in vitro. Cells cultured for 8 h in the presence of an LABA were stimulated with tumor necrosis factor-alpha for 16 h and then enzyme-linked immunosorbent assays for IL-8, GM-CSF, and VEGF were performed on the supernatants. RESULTS: Both salmeterol and formoterol significantly suppressed IL-8, GM-CSF, and VEGF secretion from tumor necrosis factor-alpha-stimulated A549 cells. Results indicated that formoterol was more potent than salmeterol in suppressing IL-8 and VEGF production. In contrast, salmeterol appeared to be more potent than formoterol in suppressing GM-CSF production. CONCLUSION: LABAs have some anti-inflammatory effects on bronchial epithelia. The differences between salmeterol and formoterol and mechanisms for the observed effects need further evaluation.

Plasma soluble CD30 level correlates negatively with age in children.

BACKGROUND AND PURPOSE: Atopic diseases are thought to be associated with cytokine-mediated immune dysregulation, for example, a T helper cell type 1/2 (Th1/Th2) imbalance. CD30 is proposed to be one of the surrogate markers for Th2 immunity. In this study, we investigated whether CD30 is a good marker for atopy and Th2 predominance in a pediatric population. METHODS: This study included 61 children with atopy and 27 normal controls. The expression of CD30 on the surface of T and B lymphocytes and soluble CD30 (sCD30) in plasma was determined. RESULTS: There was no difference in the surface expression of CD30 on B or T lymphocytes. Similarly, sCD30 levels in plasma were not different between the 2 groups. Nevertheless, we found a strong negative correlation between sCD30 and age in the control group (r = -0.72, p<0.001; sCD30 = 76.1 - 5.18 x age) as well as in the atopy group (r = -0.45, p<0.01; sCD30 = 61.1 - 3.56 x age). CONCLUSIONS: An inverse relationship was found between age and sCD30 level in children. However, our findings suggest that CD30 is not a good marker for atopic disease and that further studies on sCD30 levels must take age into consideration.

Influence of cetirizine and loratadine on granulocyte-macrophage colony-stimulating factor and interleukin-8 release in A549 human airway epithelial cells stimulated with interleukin-1beta.

BACKGROUND AND PURPOSE: In addition to being antagonists of histamine receptors, some antihistamines modulate the pathogenesis of allergic inflammation by reducing mediator release, adhesion molecule expression and, consequently, recruitment of inflammatory cells. The aim of this study was to explore the effects of 2 second-generation antihistamines, cetirizine and loratadine, on granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-8 (IL-8) secretions in human airway epithelial cells. METHODS: A549 cells were pre-incubated with cetirizine (1, 5, 10 microM) or loratadine (1 microM) individually for 16 h followed by stimulation with IL-1beta for 8 h. The levels of GM-CSF and IL-8 were measured by an enzyme-linked immunosorbant assay. RESULTS: Cetirizine (10 microM) and loratadine significantly reduced the release of GM-CSF, by 37% and 40%, respectively (p<0.05). Cetirizine (5, 10 microM) inhibited the production of IL-8 by 19% (p<0.05). However, cetirizine (1 microM) and loratadine (1 microM) did not appreciably inhibit IL-8 release. CONCLUSIONS: These observations indicate that these 2 second-generation antihistamines inhibit the release of GM-CSF and IL-8 beyond their antagonistic histamine H1 receptor activity and may thus exert clinically relevant anti-inflammatory effects in inflammatory airway disorders.

Comparison of the activities of granulocyte-macrophage colony-stimulating factor and interleukin-8 secretion between two lung epithelial cell lines.

The aim of this study was to survey the cytokine secretions in 2 human bronchial epithelial cell lines - a normal human bronchial epithelial cell line (HBEpC) and cell line A549, derived from malignant type II pneumocytes. The behavior of A549 cells is similar to epithelial cells and this line is widely used as an alternative model for studying human bronchial epithelial cell behavior. We measured the levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-8 (IL-8) after tumor necrosis factor-alpha (TNF-alpha) or interleukin-1beta (IL-1beta) stimulation in the 2 cell lines. Both cell lines responded to TNF-alpha or IL-1beta stimulation, as shown by increased GM-CSF and IL-8 secretion. The relative cost, convenience and similarity of working with these 2 cell lines suggest that A549 is preferable for use as a first-line model and that results of studies of GM-CSF and/or IL-8 secretion under various stimulation conditions with this line could be confirmed using HBEpC.

Is combination antimicrobial therapy required for urinary tract infection in children?

This retrospective study examined the characteristics of 338 pediatric patients presenting with a first episode of symptomatic urinary tract infection at Taichung Veterans General Hospital from November 1996 to December 2001. Escherichia coli was the most common pathogen (72.5%), followed by Proteus mirabilis (8.3%), Enterococcus (5.6%), and Klebsiella pneumoniae (4.7%). They were more susceptible to first-generation cephalosporin in comparison with other first-line antimicrobial agents such as trimethoprim/sulfamethoxazole, ampicillin, and gentamicin. Two hundred and eighty-seven (84.9%) of the 338 patients were divided into 3 groups according to the type of antibiotic treatment received, and the susceptibility rate and the averaged day of defervescence after effective antibiotic therapy were compared among the groups. Group 1 consisted of those patients treated with cefazolin or cephalexin alone (95%, 2.1 days); Group 2, cefazolin plus gentamicin (88.9%, 2.8 days); and Group 3, ampicillin plus gentamicin (76.1%, 2.3 days). A total of 38 (13.2%) cases from the 3 antibiotic groups did not respond to empiric antibiotics. For non-susceptible infections, when the antibiotic regimen was switched from cefazolin plus gentamicin to ampicillin alone, only 4 (20%) strains became susceptible, compared with 10 strains (62.5%) becoming susceptible after switching from ampicillin plus gentamicin to cefazolin alone (p < 0.01). The results indicated that first-generation cephalosporin alone is an appropriate treatment for pediatric cases of community-acquired urinary tract infection and suggest that antimicrobial combinations should be reserved for serious or critical cases.

Dioscorin protects tight junction protein expression in A549 human airway epithelium cells from dust mite damage.

BACKGROUND AND PURPOSE: In addition to being an allergen, the trypsin activity of dust mite extract also destroys the tight junctions of bronchial epithelium. Such damage can lead to airway leakage, which increases airway exposure to allergens, irritants, and other pathogens. Dioscorin, the storage protein of yam, demonstrates anti-trypsin activity, as well as other potential anti-inflammatory effects. This study investigated the protective role of dioscorin for tight junctions. METHODS: The immunofluorescence stains of zonula occludens (ZO-1), E-cadherin (EC) and desmoplakin (DP) proteins were compared. A cultured A549 cell line was used as a control and A549 cells were incubated with mite extract 100 mg/mL for 16 h, with or without dioscorin 100 mg/mL pretreatment for 8 h and with dioscorin 100 mg/mL alone for 16 h. Western blot was performed to detect changes in ZO-1, EC, and DP in the treated A549 cell lines. RESULTS: Loss of tight junction protein expression (ZO-1, EC, DP) was demonstrated after 16-h mite extract incubation. The defect could be restored if cells were pretreated with dioscorin for 8 h. In addition, dioscorin did not cause damage to the A549 cell lines in terms of cell survival or morphology. Western blot showed no change in the amount of tight junction protein under various conditions. CONCLUSION: Dioscorin is a potential protector of airway damage caused by mite extract.

Fanconi's syndrome, interstitial fibrosis and renal failure by aristolochic acid in Chinese herbs.

Aristolochic acid-associated nephropathy (AAN) has been identified as a separate entity of progressive tubulo-interstitial nephropathy. Its characteristic pathological findings, including hypocellular interstitial fibrosis, intimal thickening of interlobular and afferent arterioles with glomeruli sparing or mild sclerosis, have been identified. Many cases of AAN in adults have been reported in Taiwan as well as throughout the world, but it has seldom been described in children. We report on a 10-year-old boy who presented with severe anemia, Fanconi's syndrome, and progressive renal failure. Renal biopsy revealed typical findings of AAN. Aristolochic acids I and II were identified from a Chinese herb mixture ingested by the boy. AAN was diagnosed after other etiologies had been excluded. The case demonstrates the hazards of Chinese herbs with regard to children's health in Taiwan and suggests that more attention should be paid to this issue.