Objective:To summarize the clinical features of Chlamydia pneumoniae pneumonia (CPP) in children. Methods:Case series study. Clinical data of 10 children with CPP hospitalized in Department No.2 of Respiratory Medicine of Beijing Children′s Hospital, Capital Medical University from January 2019 to August 2024 were retrospectively collected, including general information, clinical manifestations, chest imaging, laboratory examination and treatment. The clinical features and prognosis were summarized.Results:Among the 10 children with CPP, 7 were male and 3 were female. The age of onset was 11.2 (10.3, 13.1) years. The course were 17 (7, 23) days. Cough occurred in 9 cases with wet cough in 7 cases, while moderate and high fever occurred in 6 cases. Besides, chest pain occurred in 4 cases, rash and hemoptysis occurred in 1 case respectively. High density mass shadow was found in 7 cases chest CT imaging, accompanied by air bronchogram sign, surrounded by halo sign, 6 cases of which were distributed under the pleura, while patchy consolidation in the remaining 3 cases. Pulmonary embolism was present in 2 cases. Among the 10 children with CPP, bilateral lung involvement was found in 3 cases and unilateral lung involvement in 7 cases. The white blood cell count was 10.21 (7.45, 11.64)×10 9/L and the proportion of neutrophils was 0.69 (0.63, 0.71). C-reactive protein increased in 7 cases, with the level of 33 (16, 77) mg/L. D-dimer increased slightly in 3 cases (0.393, 0.396, 0.739 mg/L). Serum Chlamydia pneumoniae-IgM antibody test was positive in 6 cases. Chlamydia pneumoniae nucleic acid test by bronchoalveolar lavage fluid (BALF) next-generation sequencing was positive in 6 cases. Both serum IgM antibody and BALF nucleic acid tests were positive in 2 cases. Among the 10 children with CPP, azithromycin alone was used in 5 cases, while glucocorticoid was added in 1 case. Due to poor response to azithromycin in 4 cases, doxycycline was replaced in 3 cases and minocycline was replaced in 1 case, while glucocorticoid was added in 2 cases. Moxifloxacin combined with glucocorticoid therapy was adopted in 1 case with long course after the poor response to azithromycin and doxycycline. All patients were cured finally. Conclusions:CPP mostly occurs in elderly children. The main clinical manifestations include cough, fever and chest pain. The common chest imaging feature is subpleural high-density mass shadow with halo sign. Pulmonary embolism is present in a few cases. Nucleic acid detection and (or) serology is helpful for etiological diagnosis. Some cases need glucocorticoid therapy.

Objective:To explore the risk factors for bronchiolitis obliterans (BO) after Mycoplasma pneumoniae bronchiolitis in children. Methods:A retrospective cohort study was conducted on 122 children diagnosed with Mycoplasma pneumoniae bronchiolitis in Department No.2 of Respiratory Medicine of Beijing Children′s Hospital, Capital Medical University, from March 2017 to December 2024. Clinical data, including general information, clinical manifestations, imaging findings, laboratory tests, and outcomes, were analyzed. Patients were divided into BO and non-BO groups based on the presence of BO. Differences between groups were assessed using Mann-Whitney U test, χ2 test, or Fisher exact test. Logistic regression and receiver operating characteristic (ROC) curve analysis were employed to identify risk factors and evaluate predictive performance. Results:Among 122 children (73 males, 49 females), the age at onset was 5.0 (2.4, 7.1) years. The BO group included 21 patients, and the non-BO group 101. The BO group exhibited significantly longer durations of persistent high fever and higher peak levels of C-reactive protein, lactate dehydrogenase, and D-dimer compared to the non-BO group (9 (7, 11) vs. 4 (2, 6) d, 19 (7, 35) vs. 10 (7, 18) mg/L, 438 (337, 498) vs. 315 (274, 351) U/L, 0.36 (0.27, 0.91) vs. 0.21 (0.15, 0.29) mg/L, U=295.00, 743.50, 463.50, 470.50, all P<0.05). The BO group also had higher proportions of resting oxygen saturation <0.95 on room air (100.0% (21/21) vs. 43.6% (44/101)), inspiratory retractions (57.1% (12/21) vs. 18.8% (19/101), χ2=11.53), and adenovirus co-infection (38.1% (8/21) vs. 5.0% (5/101)) (all P<0.05). Multivariate Logistic regression identified prolonged high fever ( OR=1.83, 95% CI 1.31-2.58, P<0.001), inspiratory retractions ( OR=10.48, 95% CI 1.72-63.85, P=0.011), and adenovirus co-infection ( OR=42.47, 95% CI 4.04-446.87, P=0.002) as independent risk factors for BO. ROC curve analysis revealed that a fever duration cutoff of 7.5 days predicted BO with 0.71 sensitivity and 0.92 specificity. Conclusions:Prolonged high fever (≥7.5 days), inspiratory retractions, and adenovirus co-infection are significant predictors of BO after Mycoplasma pneumoniae bronchiolitis in children, which are helpful for early clinical identification.

Objective:To summarize the clinical features of Chlamydia pneumoniae pneumonia (CPP) in children. Methods:Case series study. Clinical data of 10 children with CPP hospitalized in Department No.2 of Respiratory Medicine of Beijing Children′s Hospital, Capital Medical University from January 2019 to August 2024 were retrospectively collected, including general information, clinical manifestations, chest imaging, laboratory examination and treatment. The clinical features and prognosis were summarized.Results:Among the 10 children with CPP, 7 were male and 3 were female. The age of onset was 11.2 (10.3, 13.1) years. The course were 17 (7, 23) days. Cough occurred in 9 cases with wet cough in 7 cases, while moderate and high fever occurred in 6 cases. Besides, chest pain occurred in 4 cases, rash and hemoptysis occurred in 1 case respectively. High density mass shadow was found in 7 cases chest CT imaging, accompanied by air bronchogram sign, surrounded by halo sign, 6 cases of which were distributed under the pleura, while patchy consolidation in the remaining 3 cases. Pulmonary embolism was present in 2 cases. Among the 10 children with CPP, bilateral lung involvement was found in 3 cases and unilateral lung involvement in 7 cases. The white blood cell count was 10.21 (7.45, 11.64)×10 9/L and the proportion of neutrophils was 0.69 (0.63, 0.71). C-reactive protein increased in 7 cases, with the level of 33 (16, 77) mg/L. D-dimer increased slightly in 3 cases (0.393, 0.396, 0.739 mg/L). Serum Chlamydia pneumoniae-IgM antibody test was positive in 6 cases. Chlamydia pneumoniae nucleic acid test by bronchoalveolar lavage fluid (BALF) next-generation sequencing was positive in 6 cases. Both serum IgM antibody and BALF nucleic acid tests were positive in 2 cases. Among the 10 children with CPP, azithromycin alone was used in 5 cases, while glucocorticoid was added in 1 case. Due to poor response to azithromycin in 4 cases, doxycycline was replaced in 3 cases and minocycline was replaced in 1 case, while glucocorticoid was added in 2 cases. Moxifloxacin combined with glucocorticoid therapy was adopted in 1 case with long course after the poor response to azithromycin and doxycycline. All patients were cured finally. Conclusions:CPP mostly occurs in elderly children. The main clinical manifestations include cough, fever and chest pain. The common chest imaging feature is subpleural high-density mass shadow with halo sign. Pulmonary embolism is present in a few cases. Nucleic acid detection and (or) serology is helpful for etiological diagnosis. Some cases need glucocorticoid therapy.

Objective:To explore the risk factors for bronchiolitis obliterans (BO) after Mycoplasma pneumoniae bronchiolitis in children. Methods:A retrospective cohort study was conducted on 122 children diagnosed with Mycoplasma pneumoniae bronchiolitis in Department No.2 of Respiratory Medicine of Beijing Children′s Hospital, Capital Medical University, from March 2017 to December 2024. Clinical data, including general information, clinical manifestations, imaging findings, laboratory tests, and outcomes, were analyzed. Patients were divided into BO and non-BO groups based on the presence of BO. Differences between groups were assessed using Mann-Whitney U test, χ2 test, or Fisher exact test. Logistic regression and receiver operating characteristic (ROC) curve analysis were employed to identify risk factors and evaluate predictive performance. Results:Among 122 children (73 males, 49 females), the age at onset was 5.0 (2.4, 7.1) years. The BO group included 21 patients, and the non-BO group 101. The BO group exhibited significantly longer durations of persistent high fever and higher peak levels of C-reactive protein, lactate dehydrogenase, and D-dimer compared to the non-BO group (9 (7, 11) vs. 4 (2, 6) d, 19 (7, 35) vs. 10 (7, 18) mg/L, 438 (337, 498) vs. 315 (274, 351) U/L, 0.36 (0.27, 0.91) vs. 0.21 (0.15, 0.29) mg/L, U=295.00, 743.50, 463.50, 470.50, all P<0.05). The BO group also had higher proportions of resting oxygen saturation <0.95 on room air (100.0% (21/21) vs. 43.6% (44/101)), inspiratory retractions (57.1% (12/21) vs. 18.8% (19/101), χ2=11.53), and adenovirus co-infection (38.1% (8/21) vs. 5.0% (5/101)) (all P<0.05). Multivariate Logistic regression identified prolonged high fever ( OR=1.83, 95% CI 1.31-2.58, P<0.001), inspiratory retractions ( OR=10.48, 95% CI 1.72-63.85, P=0.011), and adenovirus co-infection ( OR=42.47, 95% CI 4.04-446.87, P=0.002) as independent risk factors for BO. ROC curve analysis revealed that a fever duration cutoff of 7.5 days predicted BO with 0.71 sensitivity and 0.92 specificity. Conclusions:Prolonged high fever (≥7.5 days), inspiratory retractions, and adenovirus co-infection are significant predictors of BO after Mycoplasma pneumoniae bronchiolitis in children, which are helpful for early clinical identification.

Objective:To investigate and summarize pediatric patients with severe Mycoplasma pneumoniae pneumonia (MPP) presenting with varied clinical and chest imaging features in order to guide the individualized treatment. Methods:This was a retrospective cohort study. Medical records of clinical, imaging and laboratory data of 505 patients with MPP who were admitted to the Department Ⅱ of Respirology Center, Beijing Children′s Hospital, Capital Medical University from January 2016 to October 2023 and met the enrollment criteria were included. They were divided into severe group and non-severe group according to whether lower airway obliterans was developed. The clinical and chest imaging features of the two groups were analyzed. Those severe cases with single lobe ≥2/3 consolidation (lobar consolidation) were further divided into subtype lung-necrosis and subtype non-lung-necrosis based on whether lung necrosis was developed. Comparison on the clinical manifestations, bronchoscopic findings, whole blood C-reactive protein (CRP) and other inflammatory indicators between the two subtypes was performed. Comparisons between two groups were achieved using independent-sample t-test, nonparametric test or chi-square test. Univariate receiver operating characteristic (ROC) curve analyses were performed on the indicators such as CRP of the two subtypes. Results:Of the 505 cases, 254 were male and 251 were female. The age of the onset was (8.2±2.9) years. There were 233 severe cases, among whom 206 were with lobar consolidation and 27 with diffuse bronchiolitis. The other 272 belonged to non-severe cases, with patchy, cloudy infiltrations or single lobe <2/3 uneven consolidation or localized bronchiolitis. Of the 206 cases (88.4%) severe cases with lobar consolidation, 88 harbored subtype lung-necrosis and 118 harbored subtype non-lung-necrosis. All 206 cases (100.0%) presented with persistent high fever, among whom 203 cases (98.5%) presented with inflammatory secretion obstruction and plastic bronchitis under bronchoscopy. Of those 88 cases with subtype lung-necrosis, there were 42 cases (47.7%) with dyspnea and 39 cases (44.3%) with moderate to massive amount of pleural effusion. There were 35 cases (39.8%) diagnosed with lung embolism during the disease course, of which other 34 cases (38.6%) were highly suspected. Extensive airway mucosal necrosis was observed in 46 cases (52.3%), and the level of their whole blood CRP was significantly higher than that of subtype non-lung-necrosis (131.5 (91.0, 180.0) vs. 25.5 (12.0, 43.1) mg/L, U=334.00, P<0.001). They were regarded as subtype "lung consolidation-atelectasis-necrosis". Of those 118 cases with subtype non-lung-necrosis, 27 cases (22.9%) presented with dyspnea and none were with moderate to massive amount of pleural effusion. Sixty-five cases (55.1%) presented with plastic bronchitis and localized airway mucosal necrosis was observed in 32 cases (27.1%). They were deemed as subtype "lung consolidation-atelectasis". ROC curve analyses revealed that whole blood CRP of 67.5 mg/L on the 6-10 th day of disease course exhibited a sensitivity of 0.96, a specificity of 0.89, and an area under the curve of 0.97 for distinguishing between these two subtypes among those with lobar consolidation. Conclusions:Pediatric patients with severe MPP present with lobar consolidation or diffuse bronchiolitis on chest imaging. Those with lobar consolidation harbor 2 subtypes as "lung consolidation-atelectasis-necrosis" and "lung consolidation-atelectasis". Whole blood CRP of 67.5 mg/L can be applied as an early discriminating indicator to discriminate between these two subtypes.

ObjectiveTo investigate the effect of Qi-invigorating and blood-activating therapy on the miR216b/Beclin1 pathway in mice with atrophic precancerous lesions of gastric cancer （PLGC） and analyze its mechanism in autophagy of PLGC. MethodSeventy-five healthy male SPF KM mice were randomly divided into a blank group and a model group. Mice in the model group were given 1-methyl-3-nitroso-1-nitrosoguanidine （MNNG） solution （150 mg·L^-1） for free drinking and gavage and ranitidine solution （0.03 g·kg^-1） daily for 12 weeks. According to the random control table， mice were divided into a model group， a Qi-invigorating group （3.5 g·kg^-1 of Astragali Radix）， a blood-activating group （0.7 g·kg^-1 of Notoginseng Radix et Rhizoma powder）， a Qi-invigorating and blood-activating group （3.5 g·kg^-1 of Astragali Radix + 0.7 g·kg^-1 of Notoginseng Radix et Rhizoma powder）， and a folic acid group （2 mg·kg^-1）. The corresponding drugs were given to mice in each group for 8 weeks and then the tissues were collected. Hematoxylin-eosin （HE） staining was carried out to observe the changes in gastric mucosa. Western blot was used to detect the protein expression of microtuble-associated protein 1 light chain 3 （LC3）Ⅰ， LC3Ⅱ， and Beclin1. Real-time polymerase chain reaction （Real-time PCR） was used to detect the mRNA expression of Beclin1 and miR-216b. ResultPathological observation showed that as compared with the blank group， the intrinsic glands of gastric mucosa decreased with atrophy and intestinal metaplasia in the model group， which were improved in all treatment groups， and the improvement of the Qi-invigorating and blood-activating group was the most obvious. As compared with the blank group， the content of LC3Ⅰ， LC3Ⅱ， LC3Ⅱ/LC3Ⅰ， and Beclin1 protein in gastric tissues of the model group was significantly decreased （P<0.05）. As compared with the model group， the content of LC3Ⅰ， LC3Ⅱ， LC3Ⅱ/LC3Ⅰ， and Beclin1 protein in gastric tissues of each treatment group was increased （P<0.05， P<0.01）. The increase was most obvious in the Qi-invigorating and blood-activating group. As compared with the blank group， the mRNA expression of Beclin1 in the model group was decreased （P<0.05）， and that of miR216b was increased （P<0.05）. As compared with the model group， the mRNA expression of Beclin1 was increased and that of miR216b was decreased in each treatment group （P<0.05）， and the changes were the most obvious in the Qi-invigorating and blood-activating group. ConclusionThe mechanism of the Qi-invigorating and blood-activating therapy， represented by Astragali Radix and Notoginseng Radix et Rhizoma， in treating PLGC may be through inhibiting the expression of miR216b and activating Beclin1， thus promoting autophagy and repairing gastric mucosa.

ObjectiveTo investigate the prevalence,antibiotic characteristics as well as molecular background of community-associated methicillin-sensitive Staphylococcus aureus (CA-MRSA) from patients with skin and sofi tissue infections from 4 different hospitals in Beijing.MethodsFive hundred and one patients were enrolled from 4 hospitals prospectively.Patients with skin and soft tissue infections and no risk factors for healthcare-associated acquisition were included.Sample from the infection sites were collected for culture.Case report form was filled out for each patient.Antibiotic susceptibility test and molecular analysis was performed for each Staphylococcus aureus isolate.ResultsTotally 164 Staphylococcus aureus isolates were cultured from the patients with skin and soft tissue infections.Of them 5 isolates were CA-MRSA.These 5 CA-MRSA isolates harbored SCCmec Ⅰ, SCCmec Ⅲ, SCCmec Ⅳ,SCCmec Ⅴ and untypable,respectively.CA-MRSA was highly resistant to β-lactamase,levofloxacin,erythromycin and clindamycin,but susceptible to vancomycin,teicoplanin,linezolid,daptomycin,and trimethoprim/sulfamethoxazole.Prevalence of PVL in community-associated methicillin sensitive Staphylococcus aureus(CA-MSSA) and CA-MRSA were 41.9％ and 2/5.Other toxins expressed similarly between them.Combined with multilocus sequence typing (MLST) and spa typing,the major clones of CA-MSSA were ST398-t034,ST7-t796,ST398-t571,ST1t127,and ST188-t189,while in CA-MRSA were ST239-t037-SCCmec Ⅰ,ST239-t632-SCCmecⅢ,ST59-t437-SCCmecV,ST8-t008-SCCmecⅣ,and ST6-t701-NT.ConclusionsThe low prevalence of CA-MRSA in Beijing and complexity of the genetic background in CA-MRSA were observed.Clone spread is not found among CA-MRSAisolates.CA-MRSAexhibithigher resistancecomparedwithmethicillinsensitive Staphylococcus aureus (MSSA).Rational drug use scheme is called in the clinical practice to prevent development of high level resistance.

Objective To explore the clinical significance of PET-CT in evaluating distant metastasis and M staging of nasopharyngeal carcinoma(NPC). Methods 257 NPC patients with no prior treatment were investigated with PET-CT and conventional imaging (chest X-ray, abdominal ultrasound, and bone scan). The findings of PET-CT in diagnosing distant metastasis and M staging were compared with those of conventional imaging according to the results of biopsy and follow-up. Results PET-CT disclosed 34 of 39 patients with distant malignancy compared with 22 patients disclosed by conventional imaging. The false positive rate of PET-CT was 12.8 %. On region-based analyses, PET-CT was more effective than bone scan and chest X-ray for detecting mediastinum metastasis (x2=4.063, P =0.041) and bone metastasis (x2=5.939, P=0.015), respectively. Compared with conventional imaging, PET-CT had an impact on the M staging of 19 patients (7.4 %), of which 15 patients were truly staged and 4 patients incorrectly staged. Conclusion PET-CT is superior to MRI in evaluating distant metastasis and M staging of NPC.

ObjectiveTo examine the relationship between HIF-1αt and VEGF expression and the clinicopathological characteristics in hypopharyngeal squamous cell carcinoma. Methods The expression status of HIF-1α and VEGF were examined by immunohistochemistric method (IHC) in 62 tumor tissue and 19 paracancerous normal tissue.The relationships between the expression of HIF-1α and VEGF and clinicopathological characteristic were analyzed. Results HIF-1αt and VEGF expression were higher in hypopharyngeal carcinoma tissues than those in paracancerous normal tissues (66. 1％:26. 3％ ;x2 =18. 02,P ＜0. 05 ;67. 7％ : 31.6％ ; x2 =19.22, P ＜ 0. 05 ). The expression intensity of HIF-1 α was related to T stage, N stage and TNM stage ( x2 =4. 23,5.83,9.94,all P ＜0. 05). The expression intensity of VEGF was related to metastasis, T stage, N stage and TNM stage (x2 =5.62,7. 38,15.75,4. 29 ,all P ＜0. 05 ). There was minus relationship between overall survival and expression level of HIF-1 α and/or VEGF (x2 =29. 25, P＜0.01; x2 =24.88, P＜ 0.01 ).On multivariate analysis,HIF-1α expression and T stage were independent prognostic factors for overall survival (x2 =4.80,5.74, all P＜0. 05).ConclusionsHIF-1α and VEGF may be considered as a parameter in evaluation of progression, metastasis and prognosis of hypopharyngeal carcinoma and also may be a direction of molecular target therapy.

Objective To analyze clinical features and treatment results of primary non-Hodgkin lymphoma of bone (PLB) and further to investigate the rational treatment. Methods Clinical data of 26 patients with PLB were analyzed. Twenty-three (88.5 %) patients received radiotherapy in combination with chemotherapy, three received chemotherapy alone, and three patients also received surgical resection. Results The pathological types of lymphoma in the patients were diffused large B-cell iymphoma (DLBCL) in 15 patients (57.7 %), small B-cell lymphoma in 1 patient(3.8 %), B-cell lymphoma with unclassified subtypes in 4 patients (15.5 %), T-cell lymphoma in 5 patients (19.3 %,among which anaplastic large cell lymphoma in 3 patients), and unclassified lymphoma in one patient (3.8 %). Of the 26 cases of PLB, 15 were at stage Ⅰ, 3 at stage Ⅱ, 3 at stage Ⅲ and 5 at stage Ⅵ. The 3- and 5-year overall survival rates were 59.16 % and 31.37 %respectively. In the eleven patients who died of lymphoma, three had Iocol-regional relapse, and nine had systemically involved lymphoma. The radiation-induced bone fracture had not been observed after local radiotherapy with median dose of 50 Gy. Conclusion Pelvis maybe a common primary site of PLB, and DLBCL type are the most observed histological subtype. The optimal treatment for PLB is radiotherapy combined with chemotherapy. Local regional radiotherapy with median dose of 50 Gy can be safe and feasible.