OBJECTIVETo compare the advantages and disadvantages between exercise challenge test (ECT) and methacholine challenge test (MCT) in the measurement of airway hyperresponsiveness (AHR), in order to identify a better and safer method to measure AHR.

METHODSForty-seven children with controlled asthma after regular treatment were enrolled. ECT and MCT were performed for each child successively, and sensitivity was obtained through comparison with the golden standard (PD20). The occurrence of bronchospasm symptoms during the two tests was recorded.

RESULTSTaking PD20 as the gold standard, in children with moderate or severe AHR, the sensitivity of MCT (61%) for the measurement of AHR was significantly higher than that of ECT (9%) (P<0.05). The consistency between MCT results and PD20 was relatively high (κ=0.614), while the consistency between ECT results and PD20 was relatively low (κ=0.006). However, in the MCT, the incidence of bronchospasm symptoms was high and positively correlated with the incidence of cough and chest distress (P<0.05).

CONCLUSIONSMCT has a higher sensitivity for the measurement of AHR, but has a higher incidence of adverse events, compared with ECT in children with controlled asthma after regular treatment.

Adolescent ; Bronchial Hyperreactivity ; diagnosis ; Child ; Exercise Test ; Female ; Humans ; Male ; Methacholine Chloride ; pharmacology

OBJECTIVE: To determine the extent to which thin-section and volumetric three-dimensional CT can depict airway reactivity to bronchostimulator, and to assess the effect of different airway sizes on the degree of reactivity. MATERIALS AND METHODS: In eight dogs, thin-section CT scans were obtained before and after the administration of methacholine and ventolin. Cross-sectional areas of bronchi at multiple levels, as shown by axial CT, proximal airway volume as revealed by three-dimensional imaging, and peak airway pressure were mea-sured. The significance of airway change induced by methacholine and ventolin, expressed by percentage changes in cross-sectional area, proximal airway volume, and peak airway pressure was statistically evaluated, as was correlation between the degree of airway reactivity and the area of airways. RESULTS: Cross-sectional areas of the bronchi decreased significantly after the administration of methacholine, and scans obtained after a delay of 5 minutes showed that normalization was insufficient. Ventolin induced a significant increase in cross-sectional areas and an increase in proximal airway volume, while the effect of methacholine on the latter was the opposite. Peak airway pres-sure increased after the administration of methacholine, and after a 5-minute delay its level was near that of the control state. Ventolin, however, induced no significant decrease. The degree of airway reactivity did not correlate with airway size. CONCLUSION: Thin-section and volumetric spiral CT with three-dimensional reconstruction can demonstrate airway reactivity to bronchostimulator. The degree of reactivity did not correlate with airway size.
Albuterol/pharmacology ; Animal ; Bronchoconstriction/*physiology ; Bronchoconstrictor Agents/*pharmacology ; Bronchodilator Agents/*pharmacology ; Dogs ; *Imaging, Three-Dimensional ; Methacholine Chloride/pharmacology ; Tomography, X-Ray Computed/*methods

OBJECTIVETo investigate the effect and mechanism of Huanglian Jiedu Tang active fraction (HIJDTAF) on calcium overloading in neurons.

METHODCerebral ischemia was imitated by hypoxia/hypoglycemia damage on fetal rat neurons. Double wavelength fluorospectrophotometry was used to assay the content of calcium in neurons in order to evaluate the effect of HLJDTAF on calcium overloading. Neurons were treated with glutamic acid, potassium chloride (KCl), A23187, caffeine(CAF) and methacholine (Mch) to analysis the related mechanism of HLJDTAF on calcium overloading in neurons.

RESULTHLJDTAF 0.3, 0.15 g x k(-1) could remarkably inhibit the calcium overloading in neurons caused by hypoxia/hypoglycemia, glutamic acid, KCl and A23187. HLJDTAF 0.3 g x kg(-1) could inhibit the increasing of calcium caused by CAF and Mch in the presence of and in the absence of extra-calcium.

CONCLUSIONHLJDTAF could remarkably inhibit the calcium overloading in neurons after cerebral ischemia injury, it probably plays the function via several pathways.

Animals ; Caffeine ; pharmacology ; Calcimycin ; pharmacology ; Calcium ; metabolism ; Cells, Cultured ; Drugs, Chinese Herbal ; pharmacology ; Glutamic Acid ; pharmacology ; Male ; Methacholine Chloride ; pharmacology ; Neurons ; cytology ; drug effects ; metabolism ; Potassium Chloride ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Spectrometry, Fluorescence

BACKGROUNDAirway hyperresponsiveness (AHR) is one of the most important characteristics of asthma. This study investigated the parameters, by which assess the airway responsiveness under tidal ventilation.

METHODSFemale BALB/c mice were sensitized and challenged with ovalbumin (OVA) (group A), and part of them were treated with budesonide aerosol (group B). All the mice were anaesthetized and mechanically ventilated. The values of tidal volume (Vt), airway pressure (PA), airway flow (F), expiratory lung resistance (RL) and dynamic compliance of the thorax and lung (CT-L) were recorded by the AniRes2003 animal lung function system. In addition, the expiratory volume in the first 0.1 second after the start of expiration (EV0.1) was obtained according to the flow-volume (F-V) curve. The maximal or minimal values of EV0.1, RL and CT-L were documented after each dose of methacholine (MCH) and compared with values from negative control group (group C).

RESULTS(1) When the dose of MCH reached 100 ng/g or 200 ng/g, the decrease of Vt in group A was much more significant than group C (P = 0.001, < 0.001 respectively), but not so between groups B and group C (P = 0.974, 0.362 respectively). (2) With the dose of 25, 50, 100 or 200 ng/g MCH, the decrease in percentage of EV0.1 in group A was much higher than group C (P = 0.012, 0.025, 0.001, 0.003 respectively), while that in group B showed no significant difference as compared with group C (P = 0.507, 0.896, 0.972, 0.785). (3) RL and CT-L: with the dose of 200 ng/g MCH, there was a statistically significant increase of RL in group A compared to group B or group C (P < 0.001, < 0.001 respectively), but no significant difference between groups B and C (P = 0.266). With doses of 100 ng/g and 200 ng/g MCH, there was a statistically significant decrease of CT-L in group A compared to group B (P = 0.001, = 0.001) and group C (P < 0.001, < 0.001 respectively), but no significant difference between groups B and C (P = 0.775, 0.310). (4) Histopathology: there were eosinophilic predominant peribronchial and perivascular inflammatory influx in murine lungs after OVA sensitizing and challenging, which could be counteracted by inhalation of budesonide in group B.

CONCLUSIONSThe decline in EV0.1 in response to MCH challenge correlated with simultaneous changes in Vt, RL and CT-L, but more sensitively than all the other parameters. The decline in EV0.1 and inflammation in murine lung could be significantly alleviated by inhalation of nebulized budesonide solution, which indicated that EV0.1 to MCH is a valid measure of AHR in mice.

Airway Resistance ; drug effects ; Animals ; Bronchial Hyperreactivity ; drug therapy ; Budesonide ; therapeutic use ; Female ; Lung Compliance ; drug effects ; Methacholine Chloride ; pharmacology ; Mice ; Mice, Inbred BALB C ; Ovalbumin ; immunology

Allergen injection therapy may improve nonallergic bronchial hyperresponsiveness, but results at the moment are less than convincing. The present study was conducted to evaluate the effect of immunotherapy on the degree of nonspecific bronchial hyperresponsiveness in patients with allergic bronchial asthma (BA) and/or allergic rhinitis (AR). Methacholine challenge bronchial provocation test, allergic skin test, serum IgE and peripheral blood eosinophil counts were performed before and after 12 months or more of immunotherapy. The improved group, as determined by a shift of at least two doubling concentrations of methacholine, was 75% of AR (n=16), 41.7% of BA (n=24) and 53.8% of BA+ AR (n=13). The geometric mean of the methacholine provocational concentration (PC20) changed from 3.40 to 14.36 mg/ml (P <0.05) in AR, from 0.73 to 1.04 mg/ml in BA (not significant), and from 1.43 to 5.07 mg/ml (P <0.05) in BA+ AR. In conclusion, nonspecific bronchial hyperresponsiveness was improved by immunotherapy in three quarters of the allergic rhinitis cases and in about a half of the allergic bronchial asthma patients, which suggests that immunotherapy might be helpful at preventing the development of bronchial hyperresponsiveness in allergic rhinitis patients, and that it does not improve bronchial hyperresponsiveness in about a half of allergic bronchial asthma patients.
Adult ; Asthma/therapy* ; Bronchial Hyperreactivity/therapy* ; Hay Fever/therapy* ; Human ; IgE/blood ; Immunotherapy* ; Methacholine Chloride/pharmacology ; Middle Age ; Rhinitis, Allergic, Perennial/therapy*

BACKGROUND: The airway muscles from allergen-sensitized animals in vitro show a heightened response to histamine, but not to carbachol. This study investigated whether the airway responsiveness to histamine in vivo is comparable to that of methacholine in human subjects with varying degrees of atopy. METHODS: One-hundred-and-sixty-eight consecutive adult asthma patients or volunteers underwent bronchoprovocation tests to both histamine and methacholine after determining their blood eosinophil counts, serum total IgE levels and skin test reactivity to 10 common aeroallergens. RESULTS: The responsiveness to histamine was significantly related to that to methacholine (r=0.609, p<0.001), but many individuals with a negative methacholine test response showed a positive response to histamine. The histamine-bronchial reactivity index (BRindex) was significantly higher than the methacholine-BRindex in subjects with a positive response to none (n=69, p<0.01) or only one (n=42, p<0.001) of histamine and methacholine, while there was no significant difference in the subjects with positive responses to both of them (n=57). The histamine-BRindex was significantly higher than the methacholine-BRindex in the subjects with mild histamine hyperresponsiveness (n=58, 1.28+/-0.01 vs. 1.20+/-0.02, respectively, p<0.001). Both histamine and methacholine responsiveness was significantly related to the atopy markers. However, the histamine-BRindex/methacholine-BRindex ratio of the atopics was not significantly different from that of the non-atopics. CONCLUSIONS: The airway responsiveness to histamine is comparable to that of methacholine in the subjects with positive responses to both histamine and methacholine, but the airway responsiveness to histamine is greater than that to methacholine in those subjects with mild airway hyperresponsiveness, regardless of atopy.
Adult ; Asthma/*physiopathology ; Bronchi/drug effects ; Bronchial Hyperreactivity/*diagnosis ; Bronchial Provocation Tests ; Bronchoconstrictor Agents/*pharmacology ; Eosinophils ; Female ; Histamine/*pharmacology ; Humans ; Immunoglobulin E/blood ; Male ; Methacholine Chloride/*pharmacology ; Severity of Illness Index ; Skin Tests

OBJECTIVETo investigate the immunoregulatory effects of pertussis protein on airway inflammatory, IFN-gamma/IL-4 ratio in bronchoalveolar lavage fluids(BALF) and airway hyperresponsiveness (AHR) in the sensitized mice.

METHODSThe sensitized mice were reexposed to ovalbumin and the airway response to methacholine injection was monitored. Inflammatory cells and cytokines IFN-gamma/IL-4 ratio in BALF were measured. Lung tissue specimens were collected for histological examination.

RESULTIntramuscular injection or intranasal instillation of pertussis protein inhibited changes in lung resistance and lung dynamic compliance, upregulated IFN-gamma/IL-4 ratio and decreased eosinophil accumulation in a dose-dependent manner. Pathological examination showed that goblet cell hyperplasia and inflammatory cells infiltration in lung tissue were suppressed by pertussis protein.

CONCLUSIONPertussis protein inhibits the inflammation and regulates the function of lungs in asthma mice, suggesting its potential application in treatment of asthma.

Albumins ; Animals ; Asthma ; chemically induced ; immunology ; therapy ; Bacterial Proteins ; immunology ; pharmacology ; Bacterial Toxins ; immunology ; pharmacology ; Bronchoalveolar Lavage Fluid ; chemistry ; Interferon-gamma ; analysis ; Interleukin-4 ; analysis ; Male ; Methacholine Chloride ; Mice ; Mice, Inbred ICR

Vascular endothelial growth factor (VEGF) is a multi-functional cytokine involved in inflammation, repair and angiogenesis in asthmatic airway. This study aimed to evaluate the role of VEGF in immediate bronchoconstriction induced by TDI inhalation, and in chronic TDI-asthma patients. 11 newly diagnosed TDI-asthma patients (group I), 12 chronic TDI-asthma patients with persistent asthma symptoms followed for >4 yr and 15 unexposed healthy controls were enrolled. In group I, induced sputum and serum were collected before and 7 hr after placebo- and TDI-bronchoprovocation test (BPT). In group II, induced sputum and serum were collected every 2 yr. VEGF levels were measured by ELISA. There were no significant differences in sputum and serum VEGF levels between patients and controls. Before and after placebo and TDI-BPT, no significant changes were noted in sputum and serum VEGF levels of group I. In group II patients, sputum VEGF showed variable changes at 1-yr, then decreased significantly at 2-yr (p<0.05), while serum VEGF showed variable changes at 2-yr, which decreased significantly at 4-yr (p<0.05). These results suggest that VEGF may play a minor role in immediate bronchoconstriction after TDI-BPT. In chronic TDI-asthma, VEGF may be involved to 2 yr after the diagnosis and the contribution may decrease after then.
Adult ; Asthma/*chemically induced/*metabolism ; Bronchi/pathology ; Enzyme-Linked Immunosorbent Assay ; Exercise ; Human ; Methacholine Chloride/pharmacology ; Middle Aged ; Placebos ; Sputum/*metabolism ; Support, Non-U.S. Gov't ; Time Factors ; Toluene 2,4-Diisocyanate/*pharmacology ; Vascular Endothelial Growth Factor A/*biosynthesis/metabolism

OBJECTIVETo investigate the effects of the new antiallergic agent N-(pyridin-4-yl)-(indol-3-yl) acetamide-45 (acetamide-45) on electric field stimulation (EFS)-and methacholine-induced contraction of airway smooth muscle in vitro.

METHODSContractions were induced by EFS in isolated trachea and bronchus of rats or by cumulative methacholine concentrations in isolated trachea of guinea pigs. Changes in isometric force of isolated airway smooth muscle were measured by force transducers and recorded on a multi-channel polygraph recorder.

RESULTSAcetamide-45 inhibited the contraction induced by EFS in isolated rat airway. The IC50 was 10.74 (95% CI 8.87-13.00) micromol.L(-1) and 18.83 (95% CI 14.57-24.33) micromol.L(-1) in tracheae and bronchi, respectively. Acetamide-45 also inhibited methacholine-induced contractile response of isolated guinea pig trachea in a concentration-dependent manner. At concentrations of 3, 10, 30 micromol.L(-1) acetamide-45 significantly decreased maximal contractile response of methacholine by 24.6%-43.2% and increased EC50 of methacholine by 3.1-to 21.4-fold.

CONCLUSIONAcetamide-45 inhibits EFS-or methacholine-induced contraction of isolated airway smooth muscle, and these effects might be non-specific inhibition on cholinergic receptor.

Acetamides ; pharmacology ; Animals ; Depression, Chemical ; Electric Stimulation ; Guinea Pigs ; In Vitro Techniques ; Male ; Methacholine Chloride ; pharmacology ; Muscle Contraction ; drug effects ; Muscle, Smooth ; drug effects ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Trachea ; drug effects

Porcine pancreatic extracts (PPE), which are widely used as a digestive drug in Korea, are composed of alpha-amylase and lipase. Such enzymes are commonly described as occupational allergens. This is the first report of occupational rhinitis caused by PPE developing into occupational asthma in a hospital nurse. She showed strong positive response in the skin prick test (SPT) (5+, wheal ratio of allergen to histamine) and had a high serum-specific IgE level to PPE, but showed a negative response in the methacholine bronchial challenge test (MBT). She had been exposed to PPE intermittently with intermittent medications for rhinitis. Two years later, she presented with rhinitis and additional asthmatic symptoms. In contrast to her first visit, she showed a positive response in the MBT, and developed bronchoconstriction in the PPE-bronchial provocation test (BPT). These findings suggest that inhalation of PPE powder can induce IgE-mediated occupational rhinitis in a hospital setting, which will develop into occupational asthma if avoidance is not complete.
Adult ; Animals ; Asthma/*diagnosis/etiology ; Bronchial Provocation Tests ; Female ; Gastrointestinal Agents/adverse effects ; Humans ; Immunoglobulin E/metabolism ; Methacholine Chloride/pharmacology ; Occupational Diseases/*diagnosis/etiology ; Pancreatic Extracts/*adverse effects ; Powders ; Rhinitis/*diagnosis/etiology ; Skin Tests ; Swine