Objective:To investigate the etiology of pleural effusion in hospitalized children in Beijing Children′s Hospital.Methods:Clinical information of children with pleural effusion admitted to Beijing Children′s Hospital Affiliated to Capital Medical University from January 2016 to December 2018 was retrospectively analyzed.According to the etiology, the children were divided into infection group (parapneumonic pleural effusion, tuberculous pleurisy and empyema) and non infection group.According to the age, the children were further divided into ≤ 3 years old, >3-7 years old and > 7 years old groups.Classification of statistics was performed, and the etiology of pleural effusion were retrospectively analyzed.Results:Among the 1 165 children with pleural effusion, 746 cases(64.0%) were infected with pleural effusion, 697 cases (697/746, 93.4%) of who were parapneumonic effusion.In patients with parapneumonic effusion, 457 cases (61.3%) had Mycoplasma pneumonia (MP) infection.Infectious pleural effusion was more common in children >7 years old(339/479 cases, 70.8%), while non-infectious pleural effusion was prevalent in children under 3 years old(188/324 cases, 58.0%). The difference was statistically significant ( χ2=96.33, P<0.05). Among the patients with non-infectious pleural effusion, 239 cases (239/419 cases, 57.0%) had multi-system diseases and 97 cases (97/419 cases, 23.2%) had malignant pleural effusion.All the 18 deaths were non-infectious pleural effusion. Conclusions:The leading reason for pleural effusion in children is infection.The most prevalent symptom is parapneumonic effusion, which is mainly caused by MP.

Objective:To investigate the clinical features of Kawasaki disease complicated with multiple pulmonary nodules and to summarize the experience of diagnosis and treatment.Methods:Clinical data of 2 cases of Kawasaki disease complicated with multiple pulmonary nodules admitted to the Department of Respiratory, Beijing Children′s Hospital in 2019 were retrospectively analyzed, and relevant literature was reviewed.Results:The 2 cases were both 3-month-old infants, with fever as the main manifestation.Both were consistent with the diagnosis of Kawasaki disease, and the respiratory symptoms were mild or not obvious.Radiological examination revealed multiple pulmonary nodules, and the results of etiology, immunology and tumor-related exams were all negative.In the follow up stage after treatment, pulmonary nodules gradually disappeared.Among 10 cases of Kawasaki disease with pulmonary nodules (8 cases from previous studies and 2 cases from this report), 90% were 3-6-month-old babies, 80% were diagnosed with incomplete Kawasaki disease, and all patients presented more than 2 nodules in the lungs, with irregular distribution and different sizes.Besides, 80% of the 10 cases had coronary artery involvement of varying degrees.One patient died in the acute disease phase, while pulmonary nodules of the remaining patients disappeared in 12 days to 1 year.Conclusions:Kawasaki disease may be complicated with multiple pulmonary nodules, especially in young infants.Most of the patients present with incomplete Kawasaki disease and are prone to coronary artery lesions, which may be related to pulmonary vascular involvement caused by Kawasaki disease.The prognosis is mostly good, and pulmonary nodules can disappear naturally with the treatment and course of Kawasaki disease.

Primary immunodeficiency diseases (PIDs) refer to immune function decrease and deficiency or immune regulation function imbalance resulted from immune cell or immunomolecular defects caused by single gene mutation.Children with PIDs are prone to develop infectious diseases.Because the immune mechanisms of hosts infected by different pathogens infecting vary, different types of PIDs are relatively susceptible to different pathogens.A number of studies have indicated that some PIDs children are more likely to develop Bacilles Calmétte-Guerin infection, severe tuberculosis and non- Tuberculous mycobacteria severe infection.In this review, several major primary immunodeficiency diseases closely related to the susceptibility of mycobacteria were summarized, including chronic granulomatous disease, severe combined immunodeficiency disease, mendelian susceptibility to mycobacterial disease, and high IgM syndrome, in order to provide a theoretical basis for early identification of such diseases.

Objective:To investigate epidemiological characteristics and macrolide-resistance of hospitalized children with Mycoplasma pneumoniae (MP) infections in Beijing from 2016 to 2019, so as to provide basis for the prevention and treatment of pediatric Mycoplasma pneumoniae pneumonia (MPP).Methods:The clinical data were analyzed retrospectively from 8 691 children hospitalized with community acquired pneumonia in Beijing Children′s Hospital between January 2016 and September 2019.MP RNA was detected by simultaneous amplification and testing (SAT), and macrolide resistance of MP was examined by MP and macrolide-resistant isolate diagnostic kit (PCR with fluorescence probes). Chi- square test was used for categorical analysis. Results:Among 8 691 cases detected by SAT, the overall detection rate of MP was 28.10% (2 442/8 691 cases). The detection rates of MP from 2016 to 2019 were 26.23%, 31.36%, 27.84 % and 26.57%, respectively.The detection rate of MP in 2017 was significantly higher than that in other years ( χ2=16.11, P<0.05). The detection rate of MP in females was 29.65%(1 107/3 733 cases), which was evidently higher than that in males 26.93%(1 335/4 958 cases) ( χ2=7.85, P<0.05). The positive rates of MP in summer[32.21% (726/2 254 cases)] and autumn[39.76%(852/2 143 cases)] were significantly higher than those in spring[17.00% (327/1 924 cases)] and winter[22.66%(537/2 370 cases)] ( χ2=315.15, P<0.001). The percentages of MP were 35.06%(732/2 088 cases) in preschoolers and 37.71%(1 160/3 076 cases) in school-age children, which were significantly higher than 11.20%(232/2 072 cases) in infants and 22.01% (318/1 445 cases) in toddlers ( χ2=509.89, P<0.001). Macrolide resistance detection was conducted in 1 524 patients by fluorescent PCR.Among them, 1 386 patients were positive for drug resistance, and the positive rate was 90.94%.The prevalence of macrolide-resistant MP from 2016 to 2019 were 88.19%, 90.93%, 90.56% and 92.90%, respectively.Macrolide-resistant rates were not related with gender, age and season. Conclusions:MP can be detected in all seasons, but most prevalently in summer and autumn.Girls are more prone to MP infections than boys.The detection rate of MP increases with age, and the positive rate is higher in preschoolers and school-age children.During the 4-year study period, the drug resistant rate of MP remain high.

Objectives : To investigate the effect of sciatic nerve electrical stimulation ( SNES) on motor function recovery in rats with incomplete spinal cord injury (SCI) and its possible mechanism. Methods : The incomplete SCI model was constructed by modified Allen ′s method. Forty⁃five Sprague⁃Dawley (SD) rats were randomly divided into three groups : Sham , SCI , and SNES. Electrical stimulation parameters were 1 ms pulse width and 100 Hz , with 20 mins each time , once a day for 21 days. The motor function was assessed by Basso⁃Beattie⁃Bresnahan (BBB) locomotor function scale , and the action potential conduction was detected by electrophysiology. Hematoxy⁃lin⁃eosin (HE) staining was used to observe the pathological changes in the spinal cord and the average cross⁃sectional area (CSA) of biceps femoris muscle fibers. The number of brain⁃derived neurotrophic factor (BDNF) and tropomyosin⁃related kinase B (TrkB) positive cells , relative mRNA and protein expression were analyzed by immunohistochemistry , reverse transcription polymerase chain reaction (RT PCR) and Western blot separately. Results: On 21 d , the BBB score and average amplitude of action potential of SNES group were higher than those of SCI group , and the difference was statistically significant (P < 0. 05) . Compared with SCI group , the pathological injury of spinal cord tissue in SNES group was significantly improved , and the average CSA of biceps femoris muscles had a statistical difference (P < 0. 05) . The number of BDNF and TrkB positive cells in SNES group was higher than that in SCI group , and there were statistical differences (P < 0. 05) . The relative mRNA and protein expressions of BDNF and TrkB in SNES group were higher than those in SCI group , with statistical differences ( P <0. 05) . The relative mRNA and protein expressions of BDNF and TrkB in SNES group were higher than those in SCI group , with statistical differences ( P <0. 05) . Conclusion These results show that SNES contributes to alleviating spinal cord tissue injury , promoting the recovery of motor function and delaying the atrophy of muscles below the injury level. The possible mechanism is related to the increased expression of BDNF⁃TrkB proteins.