bluuebunny/crossref_metadata_2025_split huggingface dataset:
Leflunomide, a novel immunomodulating agent, prevents the development of allergic sensitization in an animal model of allergic asthma
Authors: Eber  , Uhlig  , Mcmenamin  , Sly  
Published: March 2003

BackgroundLeflunomide is a new anti‐inflammatory and immunomodulating agent which is showing promise in several immune disorders, especially rheumatoid arthritis. Its activity profile suggests it may be of use in modulating allergic sensitization.ObjectiveTo investigate the effectiveness of leflunomide in preventing the development of allergic sensitization.MethodsFifty‐three brown Norway rats were sensitized by intraperitoneal injection of ovalbumin and adjuvant (ricin) on day 0. To determine the ability of leflunomide to inhibit primary allergic sensitization six rats were treated with A77 1726, the active metabolite of leflunomide, from day 0 through day 5, six were treated from day 5 through day 10, and nine rats acted as controls. On day 14, ovalbumin‐specific serum antibody levels and the magnitude of the early‐phase airway response (EAR) after inhalation allergen challenge were assessed. To determine the ability of acute topical treatment with leflunomide to inhibit mast cell degranulation, three groups of five animals received either vehicle, 100 μg A77 1726, or 1000 μg A77 1726 60 min prior to aerosol allergen challenge. To determine the effects of leflunomide treatment in vivo on mast cell function in vitro, mast cells were obtained by bronchoalveolar lavage from 17 rats (nine treated with leflunomide and eight controls). Allergen‐specific and non‐specific degranulation (48/80 induced) were studied.ResultsIn the leflunomide treated rats both ovalbumin‐specific IgE and IgG levels were significantly reduced, and the increases in lung resistance and lung elastance were essentially abolished, compared to those of the control group. Non significant differences were found in any of the parameters between the two leflunomide treated groups. Topical pre‐treatment with leflunomide did not prevent the allergen‐induced EAR. Treatment with leflunomide in vivo prevented allergen‐induced mast cell degranulation in vitro because the mast cells lacked IgE on their surface. Non allergen‐specific degranulation was normal and allergen‐induced degranulation could be restored by passive sensitization.ConclusionsThese data suggests that leflunomide can prevent primary allergic sensitization and prevent allergen‐induced EAR by inhibiting production of allergen‐specific IgE antibodies. Further studies in atopic conditions are warranted.
Mite‐antigen avoidance can reduce bronchial epithelial shedding in allergic asthmatic children
Authors: Piacentini  , Vicentini  , Mazzi  , Chilosi  , Martinati  , Boner  
Published: March 2003

BackgroundAsthma is characterized by bronchial hyperresponsiveness (BHR), bronchial mucosa inflammation and airway epithelial damage.ObjectiveThis study was designed to evaluate the effect of mite avoidance on bronchial epithelial shedding in asthmatic children sensitized to Dermatophagoides.MethodsThe percentages of airway epithelial cells and eosinophil have been counted in samples obtained by hypertonic saline‐induced sputum before and after a period of antigen avoidance in an Alpine environment (1756 m). The degree of bronchial hyperresponsiveness to methacholine was also evaluated.ResultsAfter avoidance the median (lower, Q1, and upper, Q3, quartile) percentage of epithelial cells in the sputum decreased significantly from 3.50 [0.50;6.98] to 0 [0;0.5] (P = 0.012) and eosinophil percentage decreased from 1 [0;5.25] to 0 [0,1.5] (P < 0.05). Median (Q1,Q3) PC20 increased significantly from 2.75 [1.53;7.5] to 3.25 [1.65;15.25] mg/mL (P = 0.038). After 3 weeks of re‐exposure to mite the epithelial median (Q1,Q3) percentage raised to 3.90 [1.5;6] (P = 0.027), eosinophils to 1.5 [0;3.00] (NS) and PC20 was 5.25 [1.68;14.50] (NS).ConclusionExposure to house dust mite antigen can induce airway epithelial shedding even in subjects with low eosinophil airway infiltration, thus supporting the idea that epithelial damage in asthmatics sensitized to Dermatophagoides may be due to a proteolytic activity of the mite major antigens.
Inhaled corticosteroid reduced lamina reticularis of the basement membrane by modulation of insulin‐like growth factor (IGF)‐I expression in bronchial asthma
Authors: Hoshino  , Nakamura  , Sim  , Yamashiro  , Uchida  , Hosaka  , Isogai  
Published: March 2003

BackgroundPathological studies of bronchial biopsy specimens have confirmed the apparent thickening of lamina reticularis of the epithelial basement membrane. Corticosteroids have proven to be most effective in modifying airway inflammation. However, there is not much data on the effects of corticosteroid‐treatment on the basement membrane.ObjectiveTo investigate the effects of inhaled beclomethasone dipropionate (BDP) on the thickness of basement membrane and cellular infiltration into the bronchial mucosa, and the expression of growth factors in patients with asthma.MethodsWe studied bronchial biopsies from 24 asthmatic patients before and after treatment with inhaled BDP, 400 μg twice a day or placebo, for 6 months in a double‐blind manner. Each subject recorded daily asthma symptoms and peak expiratory flow (PEF). Lung function and bronchial responsiveness to methacholine were measured before and after treatment. The thickness of the basement membrane was determined by electron microscopy. Inflammatory cells and the expression of growth factors were examined by immunohistochemistry in endobronchial biopsy specimens.ResultsAfter 6 months of treatment, we observed a significant improvement of asthma symptoms (P < 0.01), PEF (P < 0.01), diurnal variation of PEF (P < 0.05), and airway responsiveness (P < 0.05) in the BDP group compared with the placebo group. This was accompanied by a significant decrease in the thickness of the lamina reticularis (P < 0.001), and in the number of activated eosinophils (P < 0.01), T‐lymphocytes (P < 0.01), and fibroblasts (P < 0.05) in BDP‐treated patients. There was also a reduction in the expression of insulin‐like growth factor (IGF)‐I (P < 0.01). Significant correlation was found between the IGF‐I expression and collagen thickening (rs = 0.34, P < 0.01), and the number of fibroblasts (rs = 0.45, P < 0.01).ConclusionThese results suggest that corticosteroid treatment in asthma can reduce the lamina reticular thickness by modulation of IGF‐I expression with consequent inhibition of the airway infiltration by inflammatory cells, and therefore may help to prevent remodelling of the airways.
Role of GABA receptors in the bronchial response: studies in sensitized guinea‐pigs
Authors: Tohda  , Ohkawa  , Kubo  , Muraki  , Fukuoka  , Nakajima  
Published: March 2003

Backgroundγ‐Aminobutyric acid (GABA), an important inhibitory neurotransmitter in the mammalian central nervous system, is also found in peripheral tissues, including the lung. GABA has recently been shown to modulate the contraction of airway smooth muscle.ObjectiveWe studied the effect of GABA on the contractile properties of tracheal smooth muscle by measuring the tension of the trachea isolated from non‐sensitized and ovalbumin (OA)‐sensitized guinea‐pigs under isometric conditions.MethodsGuinea‐pigs were sensitized by intraperitoneal doses of OA to prepare a bronchial asthma model. Tracheal spiral rings were prepared from the OA‐sensitized as well as normal, non‐sensitized guinea‐pigs. Using the tracheal preparations, the effects of GABA and GABAa and GABAb receptor agonists (muscimol and baclofen) and antagonists (bicuculline and saclofen) on the basal tone of the trachea and on tracheal contraction induced by electrical field stimulation (EFS) were determined. The effect of GABA on tracheal contraction induced by exogenous acetylcholine was also studied.ResultsGABA and GABA agonists and antagonists had no effect on the basal tone of normal guinea‐pig tracheae. Both GABAa and GABAb receptor agonists, as well as GABA, suppressed EFS‐induced contraction of normal guinea‐pig tracheae in a reversible, dose‐dependent manner. Moreover, this suppression was reserved to the control level by either GABAa and GABAb receptor antagonists. In tracheal spiral ring prepared from OA‐sensitized guinea‐pigs, GABA and baclofen caused a smaller reversible inhibition of EFS‐induced contraction than in normal tracheal spiral ring, while muscimol inhibited EFS‐induced tracheal contraction to a similar extent to that observed in normal tracheae. GABA had no effect on the tracheal contractile response to acetylcholine.ConclusionThe results suggest that there may be a biological mechanism mediated by prejunctional GABAb receptors which attenuates cholinergic contraction of airway smooth muscle and that dysfunction of the receptors may underlie the airway obstruction in asthmatics.
Asthma, rhinitis and eczema in Maltese 13–15 year‐old schoolchildren — prevalence, severity and associated factors [ISAAC]
Authors: Montefort  , Lenicker  , Caruna  , Muscat  
Published: March 2003

BackgroundAllergic conditions, especially asthma, seem to be increasingly common the world over. The International Study of Asthma and Allergies in Childhood [ISAAC] was the first worldwide study carried out with standardized questionnaires in order to create a reliable global map of childhood allergy.ObjectivesThe Maltese Islands were one of the centres participating in this study and in this paper the data obtained from 4184 13–15 year olds from 22 state and three private schools [88.7% response rate], and also data obtained from some added ‘local’ questions addressed to the same children, are included. in order to evaluate the problem of allergic conditions in Maltese schoolchildren.Results27.9% of the participants were wheezers ‘ever’ while 16% were current wheezers. Of the latter children 15.1% were experiencing nocturnal wheezing at least once a week and 22% had a wheezing episode severe enough to limit speech. Nasal problems were present in 52.7% of these teenagers and 47.4% of all respondents persisted with these symptoms up to the year of answering the questionnaire. Hayfever had been diagnosed in 32.3% of all the children. 12.8% of respondents had a recurring itchy rash suggestive of eczema for at least 6 months of their lives and 10% had it currently. This was slightly lower than the global mean, unlike the case of wheezing, which in Malta was more common than the world average, and rhinitis, for which we had the second highest cumulative prevalence rate in the world. Multiple variables such as gender, smoking, family history of atopy, pets, soft furnishings and living in busy roads affected the prevalence and severity of the allergic conditions studied.ConclusionsAllergic conditions are very common in Maltese schoolchildren and are causing a lot of hardship to these same youngsters. The results of this study should serve as a stimulus to try and decrease this suffering through better management of these conditions, measures to control possible detrimental factors and further research on asthma, allergic rhinitis and eczema.
Phase‐contrast microscopic studies using cinematographic techniques and scanning electron microscopy on IgE‐mediated degranulation of cultured human mast cells
Authors: Kurosawa  , Inamura  , Kanbe  , Igarashi  , Tomita  , Takeda  , Miyachi  
Published: March 2003

BackgroundIsolating human mast cells is a laborious procedure. Recently, cultured human mast cells raised from umbilical cord blood cells have become available. It is necessary to investigate whether IgE‐mediated activation of these cells is mediated by exocytosis.ObjectiveTo verify IgE‐mediated activation of these cultured human mast cells morphologically.MethodsThe mast cells were raised from human umbilical cord blood cells in the presence of stem cell factor and interleukin‐6. IgE‐sensitized cultured human mast cells were activated by anti‐IgE, and morphological changes of the cells were examined under phase‐contrast microscopy using cinematographic techniques and scanning electron microscopy. Histamine release from the cells was measured with high‐performance liquid chromatography.ResultsUnder the condition in which a significant histamine release was observed from the mast cells, phase‐contrast microscopy showed that the cultured human mast cells became swollen and extruded granules. Scanning electron microscopy disclosed the extrusion of smooth and round bodies from pores formed on the activated mast cell surface.ConclusionIgE‐mediated histamine release from cultured human mast cells is accompanied by exocytosis morphologically, indicating that cultured human mast cells will help in studying the functional properties of human mast cells.
Bone mineral density and body composition in patients with airflow obstruction—the role of inhaled steroid therapy, disease and lifestyle
Authors: Lau  , LI  , Woo  , Lai  
Published: March 2003

BackgroundInhaled steroid therapy has been shown to be associated with low bone mineral density (BMD) in asthmatic patients, but its effect in men has not been specifically studied; and the relative importance of therapy, disease and lifestyle leading to low BMD has not been investigated.ObjectivesThe study was designed to compare BMD in women and men who had airflow obstruction (asthma or COAD with or without inhaled steroid therapy) with normal controls. The role of inhaled steroid treatment, disease severity and lifestyle was studied among patients.MethodsOne hundred and fourty‐four patients (106 on inhaled steroids and 38 not on inhaled steroids) and 212 age‐matched controls were studied. Body composition and BMD (at the total body, hip and spine) were measured by dual‐X‐ray densitometry (DEXA). Forced expiratory volume (FEV1) was measured in patients. A validated questionnaire was administered to measure lifestyle factors.ResultsThe body mass indices (BMI) (P < 0.001) and percentage of body fat (P < 0.001) were higher among female patients on inhaled steroids than controls. However, the BMD of the total body (P < 0.05) and spine (P < 0.001) were significantly lower in premenopausal and postmenopausal women than controls, respectively (P < 0.005). The BMD at the spine (P < 0.01) and hip (P < 0.01) in male patients were significantly lower than the controls.By multiple regression, age and use of inhaled steroid was negatively associated with BMD at the hip (P < 0.01), but not at the spine (P > 0.05).Cigarette smoking was associated with significantly lower BMD at the femoral neck (P < 0.05), and a low dietary calcium intake was associated with lower BMD at the spine (P < 0.05). In women, use of inhaled steroid was not associated with significantly lower BMD.ConclusionMen who had asthma and/or COAD had lower BMD, and this was not attributable entirely to steroid use. Cigarette smoking and a low dietary calcium intake may partially account for this difference. The difference in BMD between female patients and controls, even in those taking inhaled steroid, was small.
Primary sequence and molecular model of the variable region of a mouse monoclonal anti‐Der p 1 antibody showing a similar epitope specificity as human IgE
Authors: Mcelveen  , Clark  , Smith  , Sewell  , Shakib  
Published: March 2003

BackgroundDer p 1, a major mite allergen, elicits IgE antibody responses in 80% of patients suffering from dust mite allergy. Given the potent IgE eliciting properties of Der p 1, there is considerable interest in studying the molecular architecture of the variable (Fv) region of IgE antibodies specific for this allergen.ObjectivesIgE is present in human serum at extremely low concentrations, and as such it is practically impossible to purify sufficient quantities for structural studies. We have therefore sought to sequence and model a representative murine monoclonal (MoAb) anti‐Der p 1 antibody, as a surrogate human IgE.MethodsThe cDNA coding for the Fv region of an anti‐Der p 1 MoAb (2C7), that mimics the binding of human IgE to Der p 1, was amplified by PCR, cloned and sequenced. The predicted amino acid sequences were then compared with a directory of human germline V‐gene segments. Modelling of the Fv region of MoAb 2C7 was carried out using the extensive database of existing immunoglobulin structures in the Brookhaven PDB.ResultsThe MoAb 2C7 heavy chain showed greater than 70% homology with three members of the VH3 family, DP‐35, DP‐53 and DP‐54. Similarly, the light chain showed greater than 70% homology with 11 VK sequences, including the VKII sequences DPK18, DPK19 and DPK28. A molecular model of the Fv region of MoAb 2C7 was generated and can be accessed from the EMBL databank.ConclusionsAntibodies similar to MoAb 2C7 could be generated as part of the human repertoire. The availability of 3‐dimensional model of MoAb 2C7, as a surrogate human IgE antibody, combined with further data on its epitope specificity, will facilitate studies into IgE antibody responses to Der p 1.
The effects of anti‐asthma drugs on mediator release from cultured human mast cells
Authors: Shichijo  , Inagaki  , Nakai  , Kimata  , Nakahata  , Serizawa  , Iikura  , Saito  , Nagai  
Published: March 2003

BackgroundA method for generating human mast cells in vitro was recently established. Little is known about the pharmacological profiles of allergic mediator release from cultured mast cells.ObjectiveThe main objective was to investigate the nature of cultured mast cells from a pharmacological point of view. We examined the effect of anti‐asthma drugs on the release of histamine, sulfidoleukotrienes (LTs) and prostaglandin D2 (PGD2) from the cultured mast cells.MethodsUsing the method established by Saito et al. we cultured cord blood mononuclear cells in the presence of 80 ng/mL stem cell factor (SCF), 50 ng/mL interleukin‐6 (IL‐6) and 300 nmol/L prostaglandin E2 (PGE2), and obtained almost pure (> 99%) mast cells. We sensitized cultured mast cells with immunoglobulin E (IgE)‐rich serum, and then treated them with some anti‐asthma drugs before challenge with anti‐human IgE. Released histamine, LTs and PGD2 were measured by high‐performance liquid chromatography, commercial enzyme‐linked immunosorbent assay (ELISA) and enzyme immunoassay (EIA) systems, respectively.ResultsThe cultured mast cells released histamine, LTs and PGD2 following immunological stimulation through IgE. The mast cell stabilizing agents disodium cromoglycate (DSCG, 1 mmol/L) and azelastine (100 μmol/L) significantly inhibited the release of these three mediators. The β‐adrenoceptor agonists isoproterenol, salbutamol, and clenbuterol also inhibited all three mediators' release in a concentration‐dependent manner. The non‐selective and selective phosphodiesterase (PDE) inhibitors theophylline, rolipram, and cilostazol had no significant effect on mediator release at clinically useful concentrations. BAY × 1005 (a 5‐lipoxygenase‐activating protein inhibitor) inhibited the LTs release, whereas indomethacin (a cyclo‐oxygenase I and II inhibitor) and NS‐398 (a cyclo‐oxygenase II inhibitor) inhibited PGD2 release.ConclusionsThe present results indicate that cultured mast cells release histamine, LTs and PGD2 following IgE crosslinking. Anti‐asthma drugs showed a characteristic suppression of the release of each mediator. The suppressive actions of these drugs are similar to their pharmacological actions on human lung mast cells. These results suggest that cultured mast cells are useful for the analysis of function and pharmacological profiles of lung mast cells.
Accumulation of atopic disorders within families: a sibling effect only in the offspring of atopic fathers
Authors: Mattes  , Karmaus  , Moseler  , Frischer  , Kuehr  
Published: March 2003

BackgroundSeveral studies have reported an association between a child's risk of atopic disorders and family size. However, the inverse association might not be the same in populations with a different genetic disposition for atopic disorders.ObjectiveThis longitudinal study was designed to assess risk factors of atopy.MethodsLifetime prevalence of asthma, hay fever and eczema of 1440 families including 3165 offspring was ascertained by means of standardized questionnaires.ResultsAfter possible confounders had been controlled for, an inverse association between atopic disorders and the number of older siblings was found only in the offspring of atopic fathers (trend for older siblings: χ2 = 13.38, degrees of freedom [d.f.] = 1, P = 0.0002; odds ratio ‘no older sibling’ = 2.87 (95% confidence interval 2.18–3.78); ‘1 older sibling’ = 2.11 [1.52–2.92], ‘2 older siblings’ = 1.29 [0.74–2.23]; ‘3 or more older siblings’ = 0.15 [0.02–0.98]). No such relationship was found for children without a history of paternal atopy (trend for older siblings: χ2 = 1.51, d.f. = 1, P = 0.22; odds ratio ‘no older sibling’ = 1 [reference]; ‘1 older sibling’ = 0.82 [0.63–1.06]; ‘2 older siblings’ = 0.97 [0.67–1.40]; ‘3 or more older siblings’ = 0.64 [0.31–1.33]). The trend for older siblings in the case of paternal atopy was significantly different from the trend for older siblings without a history of paternal atopy (χ2 = 8.68, d.f. = 1, P = 0.003). The number of younger siblings was not related to child's risk of atopy (trend for younger siblings: χ2 = 0.001, d.f. = 1, P = 0.97).ConclusionsData from this study suggest a protective effect of sibship size only in children with a history of paternal atopy and if older siblings are present. The reason for this combined effect remains unclear. Thus, further investigations are needed to interpret the biological cause of the so called ‘sibling effect’.
Cloning, expression and characterization of the major latex allergen prohevein
Authors: Rozynek  , Posch  , Baur  
Published: March 2003

BackgroundAbout 70–80% of latex allergic health care workers are sensitized to prohevein (Hev b 6.01), a 20 kDa cysteine‐rich chitin‐binding protein of Hevea latex.ObjectiveThis study reports on the bacterial cloning, expression and immunochemical characterization of rHev b 6.01.MethodsProhevein was expressed in the periplasmatic space of Escherichia coli as maltose binding protein (MBP) fusion protein and purified to homogeneity after factor Xa cleavage. The IgE binding capacity of both rHev b 6.01 and prohevein isolated from fresh Hevea latex was compared by immunoblotting experiments using sera of latex‐allergic patients. The diagnostic value of rHev b 6.01 was analysed by enzyme allergosorbent test (EAST).ResultsTwo different cDNA clones of rHev b 6.01 were established. The deduced amino acid sequence of both clones revealed two and three amino acid differences in the C‐terminal domain of prohevein compared with the original database entry. Purified rHev b 6.01 bound with high affinity to chitin as its natural counterpart isolated from natural latex. In IgE‐immunblotting using sera of affected subjects binding intensity to both proteins was comparable indicating a very high antigenic similarity. The diagnostic value of MBP‐prohevein was tested in EAST using sera of 33 latex‐allergic subjects. The in vitro test showed high sensitivity and specificity and proved the diagnostic value of uncleaved MBP‐prohevein.ConclusionsThe production of recombinant latex key allergens with defined quality like prohevein is a straightforward strategy for the development of standardized in vitro test systems.