Objective:To investigate the clinical characteristics of small airway dysfunction（SAD）in children with asthma and the diagnostic value of fractional exhaled nitric oxide(FeNO) and alveolar nitric oxide (CaNO) as non-invasive indicators of airway inflammation for SAD.Methods:The informations of children with asthma who were admitted to Department of Pediatrics at the Second Affiliated Hospital of Guangzhou University of Chinese Medicine from March 2023 to February 2024 were collected.The children were divided into SAD group and non-SAD group.The clinical characteristics,eosinophil count,total IgE value,pulmonary function parameters,FeNO value and CaNO value between two groups were compared.The diagnostic value of CaNO and FeNO for SAD in children with asthma was evaluated by the area under the receiver operating characteristic (ROC) curve.Results:A total of 124 children with asthma were included,with 60 patients in the SAD group and 64 patients in the non SAD group.Compared to children in non-SAD group,children in SAD group had higher age at enrollment,history of exposure to tobacco environment,exercise-induced asthma attack,history of repeated respiratory infections,dust mite allergy,children's asthma control test (C-ACT) score <20,poor compliance,allergic rhinitis symptoms in the past year and atopic dermatitis symptoms in the past year(all P<0.05).However,there were no statistically significant differences in family history of asthma and history of milk allergy between two groups ( P>0.05).The ratio of measured and predicted forced expiratory volume in the first second (FEV1% pred),FEV1/FVC measured and predicted (FEV1/FVC%),measured and predicted peak expiratory flow rate (PEF% pred),measured and predicted instantaneous flow rate at 50% forced expiratory capacity (FEF50% pred),measured and predicted instantaneous flow rate at 75% forced expiratory capacity (FEF75% pred),and measured and predicted maximum mid expiratory flow rate (MMEF% pred) were all lower in the SAD group than those in the non-SAD group,while the inflammatory indicators such as total IgE,eosinophil count,FeNO value and CaNO value were higher in the SAD group(all P<0.001).When CaNO and FeNO were used alone or in combination for the diagnosis of SAD,the areas under the ROC curve (95% CI) were 0.92 (0.87-0.97),0.81 (0.73-0.88),and 0.92 (0.87-0.97),with sensitivities of 88.3%,76.7%,and 75.7%,and specificities of 82.8%,71.9%,and 96.9%,respectively.CaNO was negatively correlated with lung function parameters FEV1% pred,FVC% pred,FEF75% pred,MMEF% pred,FEF50% pred,and FEF75% pred ( P<0.001).CaNO was positively correlated with FeNO ( P<0.001). Conclusion:Patients with SAD have higher levels of inflammatory markers.The non-invasive indicators of airway inflammation has diagnostic and evaluation value for SAD,and the diagnostic efficacy of CaNO is higher than that of FeNO.

Objective:To investigate the clinical characteristics of small airway dysfunction（SAD）in children with asthma and the diagnostic value of fractional exhaled nitric oxide(FeNO) and alveolar nitric oxide (CaNO) as non-invasive indicators of airway inflammation for SAD.Methods:The informations of children with asthma who were admitted to Department of Pediatrics at the Second Affiliated Hospital of Guangzhou University of Chinese Medicine from March 2023 to February 2024 were collected.The children were divided into SAD group and non-SAD group.The clinical characteristics,eosinophil count,total IgE value,pulmonary function parameters,FeNO value and CaNO value between two groups were compared.The diagnostic value of CaNO and FeNO for SAD in children with asthma was evaluated by the area under the receiver operating characteristic (ROC) curve.Results:A total of 124 children with asthma were included,with 60 patients in the SAD group and 64 patients in the non SAD group.Compared to children in non-SAD group,children in SAD group had higher age at enrollment,history of exposure to tobacco environment,exercise-induced asthma attack,history of repeated respiratory infections,dust mite allergy,children's asthma control test (C-ACT) score <20,poor compliance,allergic rhinitis symptoms in the past year and atopic dermatitis symptoms in the past year(all P<0.05).However,there were no statistically significant differences in family history of asthma and history of milk allergy between two groups ( P>0.05).The ratio of measured and predicted forced expiratory volume in the first second (FEV1% pred),FEV1/FVC measured and predicted (FEV1/FVC%),measured and predicted peak expiratory flow rate (PEF% pred),measured and predicted instantaneous flow rate at 50% forced expiratory capacity (FEF50% pred),measured and predicted instantaneous flow rate at 75% forced expiratory capacity (FEF75% pred),and measured and predicted maximum mid expiratory flow rate (MMEF% pred) were all lower in the SAD group than those in the non-SAD group,while the inflammatory indicators such as total IgE,eosinophil count,FeNO value and CaNO value were higher in the SAD group(all P<0.001).When CaNO and FeNO were used alone or in combination for the diagnosis of SAD,the areas under the ROC curve (95% CI) were 0.92 (0.87-0.97),0.81 (0.73-0.88),and 0.92 (0.87-0.97),with sensitivities of 88.3%,76.7%,and 75.7%,and specificities of 82.8%,71.9%,and 96.9%,respectively.CaNO was negatively correlated with lung function parameters FEV1% pred,FVC% pred,FEF75% pred,MMEF% pred,FEF50% pred,and FEF75% pred ( P<0.001).CaNO was positively correlated with FeNO ( P<0.001). Conclusion:Patients with SAD have higher levels of inflammatory markers.The non-invasive indicators of airway inflammation has diagnostic and evaluation value for SAD,and the diagnostic efficacy of CaNO is higher than that of FeNO.

Objective:To investigate the outcome of asthma in young children after 3 years and the factors associated with the outcome.Methods:A total of 494 children aged 2 to 5 years with asthma diagnosed in 5 hospitals in Beijing from 2016 to 2017 were followed up by telephone using questionnaire survey.Information on the asthma attack, the disease control level, and the comorbidities of allergic diseases in the past 3 years was collected and analyzed.Results:Questionnaires were conducted in 387 children, including 261 males(67.4%)and 126 females(32.6%). Two hundred and forty-six patients(63.6%)had no any asthma symptom(remission) within 3 years, while 141 patients(36.4%)were found with asthma symptom(without remission). The main symptoms were as follows: wheezing in 116 cases(82.3%), recurrent cough in 59 cases(41.8%), shortness of breath in 45 cases(31.9%), chest tightness or waking up at night due to wheezing in 22 cases(15.6%). The causes of asthma attack were respiratory tract infection in 80 cases(56.7%), allergen exposure in 46 cases(32.6%), climate change or cold air stimulation in 59 cases(41.8%), strenuous exercise in 36 cases(25.5%), and irritating odor in 3 cases(2.1%). One-way anova analysis showed that significant difference( P<0.05)was respectively observed in age at follow-up, postnatal tobacco smoke exposure history, repeated respiratory tract infection before asthma onset, personal allergy history, snoring, allergic rhinitis, allergic rhinitis within 1 year, allergic conjunctivitis within 1 year between the remission group and without remission group.Multivariate unconditional logistic regression analysis showed that tobacco exposure after birth, allergic rhinitis and allergic conjunctivitis within 1 year were independent risk factors for the continuation of asthma symptoms to school age( P<0.05). Conclusion:Till the school age, more than 1/3 children still had asthma symptom and the risk factors for the unalleviated symptom were postnatal tobacco exposure, allergic rhinitis within 1 year and allergic conjunctivitis within 1 year.

Objective To evaluate the role of autophagy in the development of neuropathic pain (NP) in rats.Methods Thirty male Sprague-Dawley rats,weighing 200-220 g,were randomly divided into 3 groups (n =10 each) using a random number table:sham operation group (sham group),NP group and rapamycin (autophagy inducer) group (Rap group).Intrathecal catheter was inserted into the subarachnoid space and advanced caudally until the tip reached L4,5 segment.NP was induced by ligation of the left L5 spinal nerve (SNL) in NP and Rap groups.The L5 spinal nerve was only exposed,but not ligated in group sham.At 30 min before ligation and 2 days after operation,rapamycin 60 μg was injected intrathecally via the intrathecal catheter in Rap group,while the equal volume of vehicle (5％ dimethyl sulfoxide) was injected in sham and NP groups.The mechanical and thermal pain thresholds were measured on 1,3,5 and 7 days after ligation (T-4).The rats were sacrificed after the last measurement of pain threshold at T4.The ipsilateral L5 segment of spinal dorsal horn was removed for examination of autophagosomes (using transmission electron microscope) and for determination of the expression of LC3 Ⅱ and p62 (by Western blot) and content of IL-1β (by ELISA).Results Compared with sham group,the mechanical pain threshold at each time point and thermal pain threshold at T2-4 were significantly decreased,and the LC3 Ⅱ and p62 expression and IL-1β content were increased at T4 in group NP (P ＜ 0.05).Compared with NP group,the mechanical pain threshold at each time point,thermal pain threshold at T2-4 and LC3 Ⅱ expression at T4 were significantly increased,and the p62 expression and IL-1β content were decreased at T4 in group Rap (P ＜ 0.05).Microscopic examination showed that autophagosomes were observed in the spinal dorsal horn in NP and Rap groups,and the damage to organelles was lighter in Rap group than in NP group.Conclusion The development of NP is related to autophagic dysfunction in rats.