[Role of peak expiratory flow in the assessment and management of asthma in children].

Peak expiratory flow (PEF) is a portable, reliable, and inexpensive method for lung function assessment. PEF can reflect expiratory airflow limitation and its variability can document reversibility, which provides an objective basis for the diagnosis of asthma in children. Short-term PEF monitoring can be an important aid in the management of acute asthma exacerbations, identification of possible triggers, and assessment of response to treatment. Long-term PEF monitoring can assist in the assessment of asthma control and warning of acute exacerbations, and this is useful for children with severe asthma. This article reviews the measurements, influencing factors, interpretation, and application of PEF, and its role in the diagnosis and management of asthma in children, to provide references for the clinical application of PEF in children.

[Correlation between bronchial dilation test and asthma control level in children with asthma].

OBJECTIVE: To study the correlation between the bronchial dilation test (BDT) and asthma control level in children with asthma. METHODS: A total of 153 children with asthma, aged 5-14 years, who attended the outpatient service from March 2016 to March 2018 were enrolled. According to the presence or absence of atopic constitution, they were divided into an allergic group with 79 children and a non-allergic group with 74 children. The correlation between BDT and Childhood Asthma Control Test (C-ACT) scores was analyzed for both groups. RESULTS: All basic pulmonary function parameters were positively correlated with C-ACT scores in the non-allergic group (P < 0.05). Except the forced vital capacity, peak expiratory flow and maximal expiratory flow at 25% vital capacity in percent predicted values, the other pulmonary function parameters were positively correlated with C-ACT scores in the allergic group (P < 0.05). The improvement rates of all BDT parameters (except maximal expiratory flow at 25% vital capacity in the allergic group and maximal expiratory flow at 50% vital capacity in the non-allergic group) were negatively correlated with C-ACT scores in the two groups (P < 0.05). CONCLUSIONS: The improvement rate of BDT is well correlated with C-ACT scores in children with asthma, suggesting that BDT can be used as an index for predicting asthma control level.

Establishment of a predictive equation for pulmonary ventilation function in school-aged children in northeast China: a prospective study. / ä¸œåŒ—åœ°åŒºå­¦é¾„æœŸå„¿ç«¥è‚ºé€šæ°”åŠŸèƒ½é¢„è®¡æ–¹ç¨‹å¼å»ºç«‹çš„å‰çž»æ€§ç ”ç©¶.

OBJECTIVES: To establish a predictive equation for commonly used pulmonary ventilation function parameters in children aged 6-<16 years in northeast China. METHODS: A total of 504 healthy children from Liaoning, Jilin, and Heilongjiang provinces of China were selected for the prospective study, among whom there were 242 boys and 262 girls. The JAEGER MasterScreen Pneumo spirometer was used to measure pulmonary ventilation function. With the measured values of 10 parameters, including forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC ratio, and back-extrapolated volume (BEV), as dependent variables and age, body height, and body weight as independent variables, the stepwise multivariate regression method was used to establish the regression equation for children of different sexes. The mean of relative prediction error was used to evaluate the applicability of the predictive equation. RESULTS: The boys aged 9-<10 years and 15-<16 years had significantly higher body height, FVC, and FEV1 than the girls of the same age (P<0.05), and the boys aged 9-<10, 10-<11, 11-<12, and 13-<14 years had a significantly lower FEV1/FVC ratio than the girls of the same age (P<0.05). The correlation analysis showed that all parameters, except FEV1/FVC ratio and BEV/FVC ratio, were significantly positively correlated with age, body height, and body weight (P<0.001). Further regression analysis showed that age and body height were the influencing factors for most parameters, while body weight was less frequently included in the regression equation. Compared with the predictive equations from previous studies, the regression equation established in this study had relatively good applicability in the study population. CONCLUSIONS: A new predictive equation for the main pulmonary ventilation function parameters has been established in this study for children aged 6-<16 years in northeast China, which provides a basis for accurate judgment of pulmonary function abnormalities in clinical practice.

Vasoactive intestinal peptide inhibits airway smooth muscle cell proliferation in a mouse model of asthma via the ERK1/2 signaling pathway.

Asthma is a heterogeneous clinical syndrome characterized by airway inflammation, hyper-responsiveness and remodeling. Airway remodeling is irreversible by current antiasthmatic drugs, and it is the main cause of severe asthma. Airway smooth muscle cells (ASMCs) act as the main effector cells for airway remodeling; the proliferation and hypertrophy of which are involved in airway remodeling. Caveolin (Cav)- 1 is present on the surface of ASMCs, which is involved in cell cycle and signal transduction regulation, allowing ASMCs to change from proliferation to apoptosis. The extracellular signal-regulated kinase (ERK)1/2 signaling pathway is a common pathway regulated by various proliferative factors, which demonstrates a regulatory role in airway remodeling of asthma. There have been many studies on the correlation between vasoactive intestinal peptide (VIP) and airway reactivity and inflammation in asthma, but the functions and related mechanisms of ASMCs remain unclear. In this study, we established an airway remodeling model in asthmatic mice, and concluded that VIP inhibits airway remodeling in vivo. The in vitro effect of VIP on interleukin-13-induced proliferation of ASMCs was studied by examining the effects of VIP on expression of ERK1/2, phospho-ERK1/2 and Cav-1 in ASMCs, as well as changes in cell cycle distribution. VIP inhibited phosphorylation of the ERK1/2 signaling pathway and expression of Cav-1 on ASMCs and decreased the proportion of S phase cells in the cell cycle, thus inhibiting the proliferation of ASMCs. This study provides a novel therapeutic mechanism for the treatment of asthma.

[Diagnostic values of fractional exhaled nitric oxide for typical bronchial asthma and cough variant asthma in children].

OBJECTIVE: To study the diagnostic values of fractional exhaled nitric oxide (FeNO) for typical bronchial asthma and cough variant asthma in children, and to explore whether FeNO can be applied to differentiate typical bronchial asthma from cough variant asthma in children. METHODS: A total of 150 children who were newly diagnosed with typical bronchial asthma between June 2012 and June 2014, as well as 120 children who were newly diagnosed with cough variant asthma during the same period, were selected as subjects. FeNO measurement, spirometry, and methacholine provocation test were performed for both groups. Meanwhile, 150 healthy children were selected as the control group, and their FeNO was measured. The diagnostic values of FeNO for typical bronchial asthma and cough variant asthma were analyzed using the receiver operating characteristic curve. RESULTS: The FeNO values in the typical bronchial asthma and cough variant asthma groups were significantly higher than in the control group (P<0.01), and the FeNO value in the typical bronchial asthma group was significantly higher than in the cough variant asthma group (P<0.01). FEV1/FVC%, FEV1%pred, and PD20 were significantly lower in the typical bronchial asthma group than in the cough variant asthma group (P<0.01). The optimal cut-off value of FeNO was 19.5 ppb for the diagnosis of typical bronchial asthma, with a sensitivity of 83.3% and a specificity of 86.7%; the optimal cut-off value of FeNO was 15.5 ppb for the diagnosis of cough variant asthma, with a sensitivity of 67.5% and a specificity of 78.0%; the optimal cut-off value of FeNO was 28.5 ppb for the differentiation between typical bronchial asthma and cough variant asthma, with a sensitivity of 60.7% and a specificity of 82.5%. CONCLUSIONS: Measurenment of FeNO may be useful in the diagnosis and differential diagnosis of typical bronchial asthma and cough variant asthma.

[Expression of leptin and its receptor in lungs of asthmatic BALB/c mice and effect of budesonide on their expression].

OBJECTIVE: To determine the changes in the expression of leptin and its receptor in the lungs of mice with varying degrees of asthma before and after budesonide treatment. METHODS: Forty Balb/c mice were randomly assigned into 4 groups with 10 animals in each. One group received no treatment (control group) and the other groups were challenged with either nebulized ovalbumin (OVA) for three days (3-day group) or seven days (7-day group), or with nebulized ovalbumin followed by budesonide administration (treatment group). Changes in airway inflammation were observed using hematoxylin-eosin staining. The protein and mRNA levels of leptin and its receptor in lung tissues were determined using immunohistochemistry/Western blot and real-time PCR, respectively. RESULTS: The two asthmatic groups showed more significant pathological changes in the airway than the control and the treatment groups. Mice that were challenged by OVA for seven days showed more marked pathological changes in the airway compared with mice challenged by OVA for three days. The protein and mRNA levels of leptin in the lung tissues of the 3-day group were significantly higher than those of the control group (P<0.01), but significantly lower than those of the 7-day group (P<0.01). The protein levels of leptin receptor in the lung tissues of the 3-day group were significantly lower than those of the control group (P<0.01). The treatment group showed increased protein levels of leptin receptor compared with the 7-day group (P<0.01). No significant difference was noted between the four groups with respect to the mRNA levels of leptin receptor in the lung tissues. CONCLUSIONS: Leptin is highly expressed whereas its receptor is lowly expressed in the lung tissues of asthmatic mice. Budesonide can increase the expression of leptin receptor, but has no significant impact on the expression of leptin.

[Effects of NK-1R inhibitor WIN62577 on the migration of airway smooth muscle cells in asthmatic rats with airway remodeling].

OBJECTIVE: To study the changes in the migration of airway smooth muscle cells (ASMC) in asthmatic rats with airway remodeling and the effect of NK-1R inhibitor WIN62577 on the migration of ASMC. METHODS: Sprague-Dawley rats were randomly assigned into two groups: airway remodeling induced by asthma and normal control. ASMC from rats with asthma and airway remodeling induced by ovalbumin (OVA) inhalation for 8 weeks were primary cultured and purified. Immunofluorescence and real-time PCR were used to measure the expression of NK-1R. With NK-1R inhibitor WIN62577 treatment, the changes in the migration of ASMC were measured by transwell chambers. RESULTS: NK-1R in ASMC was expressed mainly in the cytoplasm and cell membrane in the airway remodeling group, and the mRNA expression of NK-1R was higher than the normal control group (P<0.01). The number of the migrated ASMC in the airway remodeling group was significantly higher than that in the normal control group (P<0.01). Various concentrations (10-11 mol/L, 10-10 mol/L, 10-9 mol/L and 10-8 mol/L) of WIN62577 treatment decreased the number of the migrated ASMC (P<0.05). CONCLUSIONS: NK-1R may affect airway remodeling possibly through promoting the migration ability of ASMC in rats with asthma.

[Effect of dexamethasone on osteopontin expression in the lung tissue of asthmatic mice].

OBJECTIVE: To study the correlation between airway inflammation and osteopontin (OPN) level in the lung tissue, and to study the effect of dexamethasone (DXM) on OPN expression. METHODS: Fifty mice were randomly divided into 5 groups: normal control, ovalbumin (OVA)-challenged asthma groups (OVA inhalation for 1 week or 2 weeks) and DXM-treated asthma groups (DXM treatment for 1 week or 2 weeks). The mice were sensitized and challenged with OVA to prepare mouse model of acute asthma. Alterations of airway inflammation were observed by haematoxylin-eosin staining. Serum level of OVA-sIgE was evaluated using ELISA. OPN expression in the lung tissue was located and measured by immunohistochemistry and Western blot respectively. OPN mRNA level in the lung tissue was detected by real-time PCR. RESULTS: The asthma groups showed more pathological changes in the airway than the normal control and the DXM-treated groups. Compared with the OVA-challenged 1 week group, the pathological alterations increased in the OVA-challenged 2 weeks group. The level of OVA-sIgE in serum increased in the asthma groups compared with the control and the DXM groups (P<0.01). Serum OVA-sIgE sevel increased more significantly in the OVA-challenged 2 weeks group compared with the OVA-challenged 1 week group (P<0.01). OPN protein and mRNA levels were significantly raised in the asthma groups compared with the normal control and the DXM groups (P<0.01), and both levels increased more significantly in the OVA-challenged 2 weeks group compared with the OVA-challenged 1 week group (P<0.01). CONCLUSIONS: The increased OPN expression in the lung tissue is associated with more severe airway inflammation in asthmatic mice, suggesting that OPN may play an important role in the pathogenesis of asthma. DXM can alleviate airway inflammation possibly by inhibiting OPN production.

Expert consensus on the diagnosis, treatment, and prevention of respiratory syncytial virus infections in children.

BACKGROUND: Respiratory syncytial virus (RSV) is the leading global cause of respiratory infections and is responsible for about 3 million hospitalizations and more than 100,000 deaths annually in children younger than 5 years, representing a major global healthcare burden. There is a great unmet need for new agents and universal strategies to prevent RSV infections in early life. A multidisciplinary consensus development group comprising experts in epidemiology, infectious diseases, respiratory medicine, and methodology aims to develop the current consensus to address clinical issues of RSV infections in children. DATA SOURCES: The evidence searches and reviews were conducted using electronic databases, including PubMed, Embase, Web of Science, and the Cochrane Library, using variations in terms for "respiratory syncytial virus", "RSV", "lower respiratory tract infection", "bronchiolitis", "acute", "viral pneumonia", "neonatal", "infant" "children", and "pediatric". RESULTS: Evidence-based recommendations regarding diagnosis, treatment, and prevention were proposed with a high degree of consensus. Although supportive care remains the cornerstone for the management of RSV infections, new monoclonal antibodies, vaccines, drug therapies, and viral surveillance techniques are being rolled out. CONCLUSIONS: This consensus, based on international and national scientific evidence, reinforces the current recommendations and integrates the recent advances for optimal care and prevention of RSV infections. Further improvements in the management of RSV infections will require generating the highest quality of evidence through rigorously designed studies that possess little bias and sufficient capacity to identify clinically meaningful end points.

A cross-sectional study of the clinical characteristics of hospitalized children with community-acquired pneumonia in eight eastern cities in China.

BACKGROUND: Community-acquired pneumonia in children is common in China. To understand current clinical characteristics and practice, we conducted a cross-sectional study to analyze quality of care on childhood pneumonia in eight eastern cities in China. METHODS: Consecutive hospital records between January 1, 2010 and December 31, 2010 were collected from 13 traditional Chinese medicine (TCM) and western medicine (WM) hospitals in February, May, August, and November (25 cases per season, 100 cases over the year), respectively. A predesigned case report form was used to extract data from the hospital medical records. RESULTS: A total of 1298 cases were collected and analyzed. Symptoms and signs upon admission at TCM and WM hospitals were cough (99.3% vs. 98.6%), rales (84.8% vs. 75.0%), phlegm (83.3% vs. 49.1%), and fever (74.9% vs. 84.0%) in frequency. Patients admitted to WM hospitals had symptoms and signs for a longer period prior to admission than patients admitted to TCM hospitals. Testing to identify etiologic agents was performed in 1140 cases (88.4%). Intravenous antibiotics were administered in 99.3% (595/598) of cases in TCM hospitals and in 98.6% (699/700) of cases in WM hospitals. Besides, Chinese herbal extract injection was used more frequently in TCM hospitals (491 cases, 82.1%) than in WM hospitals (212 cases, 30.3%) (p < 0.01). At discharge, 818 cases (63.0%) were clinically cured, with a significant difference between the cure rates in TCM (87.6%) and WM hospitals (42.0%) (OR = 9.8, 95% confidence interval (CI): 7.3 ~ 12.9, p < 0.01). Pathogen and previous medical history were more likely associated with the disappearance of rales (OR = 7.2, 95% CI: 4.8 ~ 10.9). Adverse effects were not reported from the medical records. CONCLUSIONS: Intravenous use of antibiotics is highly prevalent in children with community-acquired pneumonia regardless of aetiology. There was difference between TCM and WM hospitals with regard to symptom profile and the use of antibiotics. Intravenous use of herbal injection was higher in TCM hospitals than in WM hospitals. Most of the cases were diagnosed based on clinical signs and symptoms without sufficient confirmation of aetiology. Audit of current practice is urgently needed to improve care.

[Effect of montelukast on the expression of neurokinin-1 receptor in young asthmatic rats with airway remodeling].

OBJECTIVE: To investigate the effect of montelukast on the expression of sensory neuropeptide (neurokinin-1) receptor (NK1R) in young asthmatic rats with airway remodeling. METHODS: Twenty-four Sprague-Dawley rats were randomly divided into control group (n=8), asthma (n=8), and montelukast groups (n=8). A rat model of asthma was induced by ovalbumin (OVA) inhalation. Normal saline was used instead of sensitizing solution and 1% OVA in the control group. Each rat in the montelukast group was given montelukast (15 mg/kg) by gavage 2 h before OVA inhalation. All rats received their respective treatments for 8 weeks. Immunohistochemistry, real-time PCR and Western blot were used to measure the mRNA and protein expression levels of NK1R in asthmatic airway remolding and to evaluate the effect of montelukast on NK1R expression. RESULTS: The asthma group showed significantly higher mRNA and protein expression levels of NK1R than the control group (P<0.01). The mRNA and protein expression levels of NK1R in the montelukast group were significantly lower than in the asthma group (P<0.05), but significantly higher than in the control group (P<0.01). CONCLUSIONS: Rats with induced asthma have upregulated NK1R expression in the airway, and montelukast can downregulate NK1R expression during airway remodeling.

Diagnosis, treatment, and prevention of monkeypox in children: an experts' consensus statement.

Monkeypox is a zoonotic disease. Since the first human monkeypox case was detected in 1970, it has been prevalent in some countries in central and western Africa. Since May 2022, monkeypox cases have been reported in more than 96 non-endemic countries and regions worldwide. As of September 14, 2022, there have been more than 58,200 human monkeypox cases, and there is community transmission. The cessation of smallpox vaccination in 1980, which had some cross-protection with monkeypox, resulted in a general lack of immunity to monkeypox, which caused global concern and vigilance. As of September 14, 2022, there are four monkeypox cases in China, including three in Taiwan province and one in Hong Kong city. Previous foreign studies have shown that children are vulnerable to monkeypox and are also at high risk for severe disease or complications. In order to improve pediatricians' understanding of monkeypox and achieve early detection, early diagnosis, early treatment,  and early disposal, we have organized national authoritative experts in pediatric infection, respiratory, dermatology, critical care medicine, infectious diseases, and public health and others to formulate this expert consensus, on the basis of the latest "Clinical management and infection prevention and control for monkeypox" released by The World Health Organization, the "guidelines for diagnosis and treatment of monkeypox (version 2022)" issued by National Health Commission of the People's Republic of China and other relevant documents. During the development of this consensus, multidisciplinary experts have repeatedly demonstrated the etiology, epidemiology, transmission, clinical manifestations, laboratory examinations, diagnosis, differential diagnosis, treatment, discharge criteria, prevention, disposal process, and key points of prevention and control of suspected and confirmed cases.

Inhaled corticosteroids inhibit substance P receptor expression in asthmatic rat airway smooth muscle cells.

BACKGROUND: Neurokinins (NKs) participate in asthmatic airway inflammation, but the effects of NKs on airway smooth muscle cells (ASMCs) and those of corticosteroids on NKs are unknown. METHODS: To investigate the effect of budesonide on substance P (NK-1) receptor (NK-1R) expression in the lung and ASMCs, 45 Wistar rats were randomly divided into three groups: control, asthmatic, and budesonide treatment. Aerosolized ovalbumin was used to generate the asthmatic rat model, and budesonide was administered after ovalbumin inhalation. On day 21, bronchial responsiveness tests, bronchoalveolar lavage, and cell counting were conducted. NK-1R protein expression in the lung was investigated by immunohistochemistry and image analysis. Primary rat ASMC cultures were established, and purified ASMCs of the fourth passage were collected for mRNA and protein studies via real-time RT-PCR, immunocytochemistry, and image analysis. RESULTS: NK-1R mRNA and protein expression in the budesonide treatment group rat's lung and ASMCs were less than that in the asthmatic group but greater than that in the control group. CONCLUSIONS: NK-1R is involved in the pathogenesis of asthma and that budesonide may downregulate the expression of NK-1R in the ASMCs and airways of asthmatic rats, which may alleviate neurogenic airway inflammation.

[Expression of RANTES in the lung tissue of asthmatic rats, and the intervention effect of vitamin D on RANTES expression].

OBJECTIVE: To investigate the effect of vitamin D on the expression of chemokine regulated on activation, normal T cells expressed and secreted (RANTES) in the lung tissue of asthmatic rats, and the role of vitamin D in the control of asthmatic airway inflammation and the synergistic action of hormones. METHODS: Forty female Wistar rats were randomly and equally divided into normal control, asthma, vitamin D intervention, budesonide intervention, and budesonide+vitamin D intervention groups. Hematoxylin and eosin staining was used to observe pathological changes in the lung tissue. Immunohistochemistry was used to measure the protein expression of RANTES in lung tissue. Enzyme-linked immunosorbent assay was used to measure the level of RANTES in bronchoalveolar lavage fluid (BALF). Real-time quantitative PCR was used to measure the mRNA expression of RANTES. RESULTS: The asthma group showed the most significant pathological changes in the lung tissue, including inflammatory cell infiltration, bronchial stenosis and distortion and smooth muscle rupture, while the intervention groups showed fewer pathological changes. Of the intervention groups, the budesonide intervention group showed fewer pathological changes than the vitamin D intervention group, and the budesonide+vitamin D intervention group showed the mildest pathological changes, which were similar to those observed in the normal control group. Protein expression of RANTES in the lung tissue and BALF was significantly higher in the asthma group than in the normal control group (P<0.05), while it was lower in the intervention groups than in the asthma group, exhibiting significant differences between each intervention group and the asthma group (P<0.05) (except the difference in protein expression of RANTES in BALF between the vitamin D intervention and asthma groups). The budesonide+vitamin D intervention group showed less protein expression of RANTES in the lung tissue and BALF than both the budesonide intervention and vitamin D intervention groups (P<0.05). The mRNA expression of RANTES was significantly higher in the asthma group than in the normal control group (P<0.05), while it was significantly lower in three intervention groups than in the asthma group (P<0.05), however no significant difference was found between the intervention groups in this regard. The budesonide+vitamin D intervention group showed the lowest level of RANTES mRNA, with no significant difference from the normal control group. CONCLUSIONS: The mRNA and protein expression of RANTES in BALF and lung tissue increases significantly in asthmatic rats. Vitamin D intervention can decrease the expression of RANTES, suggesting that vitamin D can reduce airway inflammation by regulating the expression of RANTES. Vitamin D can be used together with budesonide to further decrease the mRNA and protein expression of RANTES.

[Changes to surfactant proteins in the bronchoalveolar lavage fluid and serum of children with Mycoplasma pneumoniae pneumonia].

OBJECTIVE: To study the changes to surfactant proteins in the serum and bronchoalveolar lavage fluids (BALF) of children with Mycoplasma pneumoniae pneumonia (MPP) and their significance. METHODS: Self-control method was used in the study. Forty-seven MPP children were divided into single lung infected (n=32) and bilateral lung infected groups (n=15) according to lung CT results. Surfactant proteins SP-A, B, C and D were measured using ELISA in the serum and BALF in the two groups. The correlations between SP-A, B, C and D content in the serum and BALF were evaluated by Spearman correlation analysis. RESULTS: SP-A, B, C and D content in BALF from the majorly infected or infected lung were significantly higher than from the opposite lung and serum (P<0.01). SP-A, B and C content in serum was significantly lower than in BALF from the non-infected lung in the single-side infected lung group (P<0.01 or 0.05), but there was no significant difference between serum SP-D content and BALF SP-D content from the non-infected lung. There were no significant differences in SP-A, B, C and D content in serum and BALF from the minorly infected lung in the bilateral lung infected group. Serum SP-D content was positively correlated with BALF SP-D content from the majorly infected lung in the bilateral lung infected group (P<0.01). CONCLUSIONS: Serum SP-D content may serve as a biomarker for evaluating the severity of pulmonary infection in children with community-acquired pneumonia.

[Effects of Streptococcus pneumoniae on the ultrastructure of alveolar epithelial cells type â ¡ in the lung tissues of mice and children].

OBJECTIVE: To explore the possible mechanisms of lung necrosis by examining the effects of Streptoccus pneumoniae (S.p) on the ultrastructure of alveolar epithelial cells type Ⅱ(AEC-Ⅱ) in the lung tissues of mice and children. METHODS: The suspended solutions of S.p strains cultured from the blood of a child with pneumococcal necrotizing pneumonia (PNP) (0.3 mL, CFU: 1×108/L) were instilled into the trachea of pathogen-free mice to prepare PNP model. The same amount of normal saline was given for the control group (10 mice). The samples (1 mm3) from the lower lobe of right lung of the mice were obtained 92 hrs later and fixed in 2.5% glutaraldehyde. Normal and abnormal lung tissues (1 mm3) were obtained while operation for the left lower lobe pulmonary cavity excision in the child with PNP. The specimens were fixed in 2.5% glutaraldehyde and stored at 4℃. A transmission electron microscope was employed for the examination of the ultrastructure of AEC-Ⅱ in the lung tissues. RESULTS: Quantitative reduction and exfoliation of microvilli in S.p-infected AEC-Ⅱ were observed in both mice and this child compared with the control. Enlarged size, enhanced evacuation and reduced density of the lamellar bodies were also presented. The number of mitochondria was obviously reduced. The nucleolus chromatin concentrated and showed an inhomogeneous distribution. CONCLUSIONS: S.p infection results in comparable damage to the ultrastructure of AEC-Ⅱ in mice and children that may represent one of the primary causes responsible for S.p-induced lung tissue necrosis.

Sirtuin 6 attenuates epithelial-mesenchymal transition by suppressing the TGF-ß1/Smad3 pathway and c-Jun in asthma models.

Allergic asthma is a chronic inflammatory airway disease involving airway remodeling. The histone deacetylase sirtuin6 (SIRT6) has protective effects in cardiac and liver fibrosis; however, its role in airway remodeling is unclear. In this study, we investigated the expression of SIRT6 in a rat model of airway remodeling and observed its effects on the epithelial-mesenchymal transition (EMT) in human bronchial epithelial 16HBE cells. Sprague-Dawley rats were sensitized and challenged with ovalbumin to induce airway remodeling or with phosphate-buffered saline as a control for different periods. Morphological changes, cell counts in the bronchoalveolar lavage fluid, and SIRT6 expression were assessed. 16HBE cells were transfected with plasmids to silence or overexpress SIRT6. Western blotting, quantitative polymerase chain reaction, Transwell assays, and cell proliferation assays were performed to examine the transforming growth factor (TGF)-ß1-induced changes in EMT indicators and EMT-related cell behaviors. SIRT6 expression was upregulated in bronchial epithelial cells from rats with airway remodeling and in TGF-ß1-treated 16HBE cells. SIRT6 overexpression affected TGF-ß1-induced changes in EMT markers and EMT-like cell behaviors. In particular, SIRT6 overexpression alleviated the reduction in E-cadherin and the increases in N-cadherin, vimentin, alpha-smooth muscle actin, and metalloproteinase-9 levels in TGF-ß1-treated 16HBE cells. Forced expression of SIRT6 also decreased the rates of cell migration and proliferation, reduced activation of phosphorylated Smad3 induced by TGF-ß1 treatment, suppressed the acetylation level at histone H3K9, and inhibited the transcriptional activity of the c-Jun promotor. These results suggested that SIRT6 expression is upregulated during airway remodeling and modulates EMT in bronchial epithelial cells targeting Smad3 and c-Jun, highlighting a new therapeutic candidate for improving airway remodeling in asthma.

Bidirectional Association Between Asthma and Obesity During Childhood and Adolescence: A Systematic Review and Meta-Analysis.

Objective: Co-occurrence of pediatric asthma and obesity has been widely reported, yet the causal directions between these two disorders are still not well-understood. The objective of this meta-analysis is to explore whether there is a possibility of a bidirectional association for these two disorders in children and adolescents. Methods: PubMed, Embase, Web of Science, and CENTRAL databases were searched up to August 2020. Cohort studies reporting the associations of obesity with risk of physician-diagnosed asthma or physician-diagnosed asthma with risk of obesity in children and adolescents were eligible for the review. Results: A total of 3,091 records were identified from the four databases, with final inclusion of nine. Six studies reported the association between obesity and risk of asthma; three studies reported the association between asthma and risk of childhood obesity. As evaluated by the Newcastle-Ottawa quality assessment scale, all studies were assessed as high-quality studies. There was a statistically significant association between obesity and increased risk of physician-diagnosed asthma in children and adolescents. The pooled RR was 1.39 (95% CI: 1.28, 1.50; p < 0.001), with significant heterogeneity across studies (I 2 = 81.7%; p heterogeneity < 0.001). The pooled RR in boys was 1.53 (95% CI: 1.17, 1.99; p = 0.002), but such a significant association was not observed in girls (RR = 1.17, 95% CI: 0.79, 1.72; p = 0.434). For the association of asthma with risk of childhood obesity, the pooled RR was 1.47 (95%CI: 1.25, 1.72; p < 0.001) without statistical heterogeneity (I 2 = 0%, p heterogeneity = 0.652). Conclusion: There is a bidirectional association between obesity and asthma during childhood and adolescence, suggesting that childhood obesity drives an increase in the onset of asthma; meanwhile, childhood asthma may also increase risk of obesity for children and adolescents.

Updated diagnosis, treatment and prevention of COVID-19 in children: experts' consensus statement (condensed version of the second edition).

In the early February, 2020, we called up an experts' committee with more than 30 Chinese experts from 11 national medical academic organizations to formulate the first edition of consensus statement on diagnosis, treatment and prevention of coronavirus disease 2019 (COVID-19) in children, which has been published in this journal. With accumulated experiences in the diagnosis and treatment of COVID-19 in children, we have updated the consensus statement and released the second edition recently. The current version in English is a condensed version of the second edition of consensus statement on diagnosis, treatment and prevention of COVID-19 in children. In the current version, diagnosis and treatement criteria have been optimized, and early identification of severe and critical cases is highlighted. The early warning indicators for severe pediatric cases have been summarized which is utmost important for clinical practice. This version of experts consensus will be valuable for better prevention, diagnosis and treatment of COVID-19 in children worldwide.

Neurokinin-1 receptor antagonist decreases [Ca2+]i in airway smooth muscle cells by reducing the reverse-mode Na+/Ca2+ exchanger current.

Airway smooth muscle (ASM) is involved in asthma airway inflammation. The aim of this study was to evaluate the effect of substance P and neurokinin-1 receptor (NK-1R) antagonist on intracellular calcium concentration ([Ca2+]i) in airway smooth muscle cells (ASMCs), ASMC contraction, and the effect on reverse-mode Na+-Ca2+ exchanger (NCX) currents in ASMCs. In our study, primary rat ASMCs were cultured. ASMCs were identified by immunofluorescence. [Ca2+]i variations were measured by fluorescence microscopy. Cell shortening (%) and relaxation (%) were analyzed with phase-contrast microscopy. Patch clamp techniques were used to assess NCX currents in ASMCs. We found that substance P increased, and NK-1R antagonist decreased [Ca2+]i in ASMCs. Substance P induced ASMCs contraction, and NK-1R antagonist can make ASMC relax. Patch clamp techniques were implemented to analyze NCX currents in ASMCs. Substance P increased reverse-mode NCX currents in ASMCs but the current density was lower than the one treated with acetylcholine (Ach). NK-1R antagonist reduced reverse-mode NCX current activity in ASMCs, and the current density was similar to the one treated with the reversed NCX inhibitor. So, we concluded that substance P increased [Ca2+]i in ASMCs by promoting the reverse-mode NCX current and stimulating ASMCs, whereas NK-1R antagonist decreased [Ca2+]i in ASMCs by decreasing the reverse-mode NCX current to make ASMCs relax.