Application of impulse oscillometry in the measurement for childhood bronchial hyperresponsiveness / 中华实用儿科临床杂志

Objective To explore the effectiveness of impulse oscillometry(IOS)in airway responsiveness measurement and to find out the positive threshold of IOS for asthma diagnosis. Methods Seventy-nine children aged 6-14 years who had suspicious asthma,were recruited into the study. The positive criteria of the methacholine bron-chial provocation test was a 20％ reduction in forced expiratory volume in the first second (FEV 1 )compared to base-line. Simultaneously measured changes in various parameters of IOS,including resonant frequency(Fres),impedance at 5 Hz(Zrs),resistances at 5 and 20 Hz(R5,R20),reactance at 5 Hz(X5),and area of reactance(AX). The results of the challenge test were divided into positive and negative groups according to the pulmonary ventilation function me-thod. The differences between the 2 groups of IOS parameters before and after the challenge test,and the correlation be-tween the change rate of FEV1 and the change rate of IOS parameters were compared,and the positive judgment criteria of IOS parameters in the determination of respiratory responsiveness were determined. Results The positive group of bronchial provocation test had 37 patients and negative group had 42 patients. There was no significant difference in the basic values of parameters between the positive group and the negative group (all P > 0. 05). Changes in Zrs,R5,X5 of IOS were correlated with changes in FEV1 (r = 0. 374,0. 310,0. 449,all P < 0. 05). By single factor analysis,the area under the receiver operating characteristic(ROC)carve (AUC)showed:basic value of Zrs increased by 45. 85％,R5 increased by 45. 72％,X5 increased by 80. 74％ respectively compared to the baseline showed the optimal combination of sensitivity and specificity. In multivariate Logistic regression models,when Zrs and R5 were combined to measure the airway responsiveness,the sensitivity and specificity were 73. 0％ and 81. 0％,respectively. Conclusions IOS and spirometry can be used to determine airway responsiveness in children during methacholine bronchial challenge. Zrs≥45. 85％,or R5≥45. 72％,or X5≥80. 74％,or Zrs and R5 of multiple regression formula can be used as the positive criteria for young children with airway heperresponsiveness,the combination of Zrs and R5 has higher sensitivity and specificity.

Neutrophilia induced by histamine challenge in guinea pig: The role of IL-5, IL-10 and IL-17A, but not CXCL8

Background: Histamine is widely used as a pharmacological tool for the evaluation of airway responsiveness. Nevertheless, undesirable and contradictory effects have been described after histamine provocation tests. In previous evaluations of airway responsiveness in a guinea pig asthma model, the control groups consistently showed high neutrophil counts in bronchoalveolar lavage fluid (BALF) immediately after the histamine challenge. The changes in cytokine and chemokine levels in guinea pig lung associated with histamine induced-neutrophilia are described in this paper. Methods: Immediately and 24 h after histamine challenge, airway wall and BALF eosinophil and neutrophil counts as well as lung cytokines (IL-5, IL-10, IL-17A, TNFα and TGFβ) and chemokines (CCL11 and CXCL8) levels were evaluated. Results: Histamine inhalation generated an all-or-none bronchial response, and the dose inducing airway obstruction was similar in all guinea pigs. Immediate increases in neutrophil counts in airway wall and BALF and in IL-5, IL-10 and IL-17A levels in the lung homogenate were observed after histamine challenge. Significant correlations were found between neutrophil counts from airway wall and IL-5, IL-10 and IL-17A levels in the lung homogenate. Conclusions: Histamine inhalation induced rapid neutrophil LBA and airway wall infiltration that was not associated with CXCL8 expression but with a Th2 and Th17 cytokines that probably are involved in the recruitment and activation of neutrophils.

The influence to airway responsiveness of asthmatic children treated with low dose azithromycin / 国际儿科学杂志

Objective To investigate the influence to airway responsiveness by using low dose azithromycin in asthmatic children.Methods One hundred and four children with moderate persistent or severe persistent asthma were divided into Group A (include 56 cases) and Group B (include 48 cases) randomly.All of the patients were treated with seretide (50/100 μg/dose) 2 doses/d for4 weeks.Children with severe persistent asthma were added with montelukast 5 mg/d orally,children accompanied with allergic rhinitis were added with nasonex 100 ～200 μg/d intranasal.And four weeks later,all of the patients were given a 12-week observation.Group A kept on treating with seretide (the same dose as before),and azithromycin 7.5mg/ (kg·d) (the maximal dose was 250 mg/d) orally was administered intermittently twice a week.Group B kept on treating with seretide ( the same dose as before) only.At the end of the study,we assessed the number of days with asthmatic symptoms in two groups respectively.At the beginning and the end of the study,we measured the forced expiratory volume in one second (FEV1 ％ ),peak expiratory flow (PEF％),the PD20-FEV1 by histamine challenged at the 15 th day and at the end of the study in two groups.Twenty-four hours before the study and twenty-four hours after the study,we measured the 24-hour urinary 17-OHCS and 17-KS of the patients.Two weeks after the study,we measured the serumal ALT and AST of the patients.Results ( 1 ) The number of days with asthmatic symptoms was ( 2.13 ± 1.18 ) d and ( 2.25 + 1.19 ) d respectively in Group A and B,and there was no significant difference between two groups ( t =0.54,P=0.59).(2) The PEF％ before and after the study in Group A was (49.77 ± 15.02)％ and (82.73 ±7.81 ) ％ respectively ( t =16.59,P =0.000).The PEF％ before and after the study in Group B was (52.69±13.90)％ and (81.15±7.28)％ respectively (t=12.37,P=0.000).The FEV1％ before and after the study in Group A was (50.48 ± 15.08 ) ％ and ( 83.18 ± 6.61 ) ％ respectively ( t =16.25,P =0.000).The FEV1 ％ before and after the study in Group B was ( 53.29 ± 13.89 ) ％ and ( 82.73 ± 6.10 ) ％ respectively (t=12.83,P=0.000).(3) The PD20-FEV1 at the 15 th day and at the end of the study in Group A was (65.13 ±26.08) μg and (460.79 ±221.72) μg respectively (t =13.54,P =0.000).The PD20-FEVt at the 15th day and at the end of the study in Group B was ( 65.27 ± 25.75 ) μg and (65.66 ± 25.09 ) μg respectively (t =1.45,P =0.15).Compared the PD20-FEV1 between the two groups,there was significant difference at the end of the study (t =13.29,P =0.000).(4) The 24-hour urinary 17-OHCS was (14.27 ±3.41)nmol/L and (14.43 ±3.69) nmol/L respectively of Group A and was (14.31 ±3.66)nmol/L and ( 14.56 ± 3.37 ) nmol/L respectively of Group B before and after the study,and there was no significant difference between Group A and Group B.The 24-hour urinary 17-KS was ( 22.43 ± 5.69 ) nmol/L and (22.07±5.21 ) nmol/L respectively of Group A and was (22.40±5.04) nmol/L and (22.54 ±4.74)nmol/L respectively of Group B before and after the study,and there was no significant difference between Group A and Group B.(5) The serumal ALT of Group A and B measured 2 weeks after the study was (20.39± 9.12) U/L and ( 20.83 ± 7.83 ) U/L respectively ( t =0.26,P =0.79 ).The serumal AST of Group A and Group B measured 2 weeks after the study was (20.68 ±8.67) U/L and (21.44±8.60) U/L respectively (t =0.45,P =0.66 ).Conclusion It can significantly decrease the bronchial hyperreactivity of asthmatic children treated with low dose azithromycin orally for 12 weeks and seretide inhaled,but it can not decrease the number of days with asthmatic symptoms in the patients,can not improve the FEV1 and PEF significantly.There wasn't any influence on adrenal glands.function and liver function of the patients.

Pharmacologic bronchodilation response to salbutamol in COPD patients.

Background: Airway hyperresponsiveness (AHR) is the most characteristic feature of asthma, which is reported in COPD patients and smokers. Increased airway responsiveness to ί-agonists is also demonstrated in asthmatics as well as smokers. However, there is no report regarding AHR to ί-agonist drugs in COPD patients. Therefore, in this study pharmacologic bronchodilation response to salbutamol in COPD patients was examined. Materials and Methods: The threshold concentrations of inhaled salbutamol required for a 20% change in forced expiratory flow in 1 sec (FEV 1 ) as PC 20 , or a 35% change in specific airway conductance (sGaw) as PC 35 was measured in 14 COPD patients and 14 normal subjects. Results: Airway responsiveness to salbutamol in COPD patients (PC 20 = 14.14 ± 1.62 and PC 35 = 9.70 ± 1.48 mg/l) was significantly lower than normal subjects (PC 20 = 224.57 ± 16.62 and PC 35 = 81.87 ± 8.16 mg/l, P < 0.001 for both cases). The values of FEV 1 and sGaw in COPD patients (56.43 ± 14.45 and 0.081 ± 0.120 respectively) were significantly lower than those of normal subjects (104.07 ± 5.72 and 0.194 ± 0.041 respectively), (P < 0.001 for FEV 1 and P < 0.005 for sGaw). There was a significant correlation between FEV 1 with PC 20 salbutamol (r = 0.862, P < 0.001). The correlations between PC 20 and PC 35 was also statistically significant (r = 0.862, P < 0.001). Conclusion: These results showed increased airway responsiveness of most COPD patients to salbutamol which was highly correlated to airway caliber.

Obesity affects airway reactivity / 中国实用内科杂志

Objective To explore if obesity is related to bronchial hyperresponsiveness in different sexuality.Methods A total of 1180 patients with provocation test positive were studied.We analysed the relation of body mass index(BMI)and FVC,FEV1,the relation of BMI and PC_20 FEV1 in all patients and in the men and the women,respectively.Results There was negative correlation between BMI and FVC,FEV_1 of the whole patients.There was also negative correlation between BMI and PC_20FEV_1 of the whole patients and the women but no correlation of the men.PC_20 FEV_1 of men was higher than that of women.Conclusion Obesity is related to the decrease of lung function and the increase of airway responsiveness,this affection is obviously in women.The airway responsiveness of women is higher than that of man.

The effect of ozone exposure on antioxidant responses in murine model of asthma / 천식및알레르기

BACKGROUND AND OBJECTIVE: Ozone exposure has been shown to modify the protective antioxidant defense network in the respiratory tract. The aim of the present study was to evaluate the effects of ozone exposure on antioxidant status in murine model of asthma. METHODS: Enhanced pause of breathing (Penh) as marker of airway obstruction was measured to determine whether bronchoconstriction occurred in BALB/c mice using barometric whole-body plethysmography after ozone and ovalbumin (OVA) exposure. Antioxidant levels were determined using high performance liquid chromatography with electrochemical detection in bronchoalveolar lavage (BAL) fluid and lung tissue homogenates. RESULTS: Uric acid and gamma-tocopherol concentrations were significantly increased in BAL fluid following ozone and OVA exposure (p<0.01). Malondialdehyde concentrations in lung tissue homogenates were significantly increased in ozone and OVA exposed group than in the saline exposed group (p<0.05). Uric acid concentrations were increased in ozone and OVA exposed group than in the saline exposed group. Increases in Penh were significantly higher in ozone and OVA exposed group than in saline exposed group. The proportion of neutrophils in BAL fluid was significantly higher in ozone exposed group than in saline exposed group (p<0.01). The level of ascorbate was correlated with the level of gamma-tocopherol (r=0.65, p<0.05). Penh was not related with antioxidant responses. CONCLUSION: The data indicate that antioxidant responses may serve as protective mechanism to minimize the effects of ozone exposure in murine model of asthma.

Effect of airway remodeling on airway responsiveness in asthmatic guinea pigs / 中国病理生理杂志

AIM: To establish a guinea pig asthma model and to evaluate the effect of airway remodeling on airway responsiveness. METHODS: The guinea pig asthma model was established by ovalbumin (OVA) sensitization and challenge repeatedly. Bronchial provocation tests were conducted through intravenous injection of acetylcholine. The airway morphologic parameters were measured by computer image analysis system. White blood cells and the differential count in bronchoalveolar lavage fluid (BALF) were examined. RESULTS: The resistance of airway was increased significantly after 4 weeks of OVA exposure, but the increase disappeared upon prolonged exposure. After 8 weeks of OVA exposure, fiber tissue in large airway was increased, and the thickness of smooth muscle layer of small airway was enlarged, as compared with that in control animals. CONCLUSION: Airway responsiveness has changed after prolonged OVA exposure in guinea pigs. This change is related to airway remodeling. [