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Objective: It was found that the level of anti-neutrophil cytoplasmic antibodies (ANCA) in children with bronchiolitis obliterans (BO) was increased and was related to the severity of the disease previously. This study aims to explore the mechanism of ANCA in the process of BO. Methods: ANCA and components of neutrophil extracellular traps (NETs) were detected in plasma from patients with BO (n=40) and age- and sex-matched healthy children (n=11). Plasma IgG was extracted from ANCA-positive BO children and normal controls to stimulate neutrophils, and the production of reactive oxygen species (ROS) and NETs were detected. Small airway epithelial cells (SAECs) were treated directly with NETs of various concentrations. Cell viability was determined by CCK8, and secreted inflammatory cytokines were detected by ELISA. The IgG treated neutrophils were co-cultured with SAECs and the levels of cytokines in the culture supernatants were detected by ELISA. Results: The levels of ANCA and NETs components including dsDNA, neutrophil elastase (NE) and myeloperoxidase (MPO) in the plasma of BO children were significantly higher than those of healthy controls. ANCA-positive IgG induced neutrophils produce ROS and NETs. The cell viability of SAECs was significantly reduced upon treatment with NETs in a concentration-dependent manner. The levels of IL-8, IL-17, TNF-α and TGF-β secreted by SAECs treated with NETs were increased significantly, and the degree of increase was positively correlated with the concentration of NETs. The co-culture of neutrophils stimulated by ANCA IgG with SAECs significantly increased the expression of cytokines including IL-8, IL-17, TNF-α and TGF-β. Conclusions: NETs induced by ANCA may exacerbate airway inflammation in children with BO.

Objective To summarize the clinical characteristics and treatment experiences of patients with plastic bronchitis (PB).Methods All patients who were diagnosed with PB by bronchoscopic removal of tree-like casts at a single institution from January 2012 to May 2022 were retrospectively reviewed. Demographic and clinical data were retrieved from electronic patient records༎Results A total of 55 patients, with a median age of 5.3 years, were eligible for the study. Nineteen cases had underlying diseases, among which asthma was the most common. Clinical symptoms were characterized by cough and fever, while moist rales (78.2%) and dyspnea (61.8%) were the most common signs. The most common laboratory finding was elevated C-reactive protein (58.2%). Patchy exudation was the most frequent radiographic finding (81.2%), followed by consolidation (60.0%) and pleural effusion (43.6%). Respiratory pathogens were detected in 41 cases, and M. pneumoniae was the most common one (41.8%), followed by adenovirus (20.0%) and influenza B virus (10.9%). The casts were removed by alveolar lavage, combined with ambroxol immersion (63.6%) and forceps (30.9%). Patients received an average of 2.3 bronchoscopies, and the median time for the first procedure was 3 days after admission. Antibiotics were given to all patients, methylprednisolone to 33 (60.0%), and gamma globulin to 25 (45.5%). A total of 53 cases were improved with an overall mortality rate of 3.6%.Conclusions PB in children is characterized by airway obstruction, mostly caused by respiratory infections, and timely removal of the cast by bronchoscopy is the most effective treatment.

Despite improvement in the long-term survival rate following pediatric acute myeloid leukemia (AML), the rate remains low, even with optimal treatment. The present study reports the long-term outcome of a small patient group treated with a single drug, high-dose chemotherapy (HDCT) with cytarabine, including consolidation and maintenance therapy. RT-PCR was conducted to assess 43 fusion genes, and after treatment, all cases have been followed up for 20 years (June 2002-December 2020). With an 80% 5-year survival rate, the results of this study highlight the possibility that pediatric AML can be reasonably effectively treated with relatively simple chemotherapy when necessary. HDCT is clinically safe, effective and relatively inexpensive. We propose that in the context of limited resources, HDCT should be considered as an alternative therapy for pediatric AML.

Respiratory syncytial virus (RSV) is the major cause of pneumonia and bronchiolitis in infants and young children and mediates substantial morbidity and mortality in the elderly and immunocompromised globally. The development of a safe and effective RSV vaccine and an optimized neutralizing antibody (NAb) with strong virus-neutralizing activity is appealing. To gain some detailed knowledge of the humoral immune response to RSV subgroup A (RSV-A) and RSV-B, we investigated the seroprevalence of pre-existing NAbs by using the microneutralization assay in healthy adult from Guangzhou, southern China. We found that the overall seropositive rate was 84.86% for anti-RSV NAbs. Furthermore, the seropositive rates were 68.47% and 73.61% for anti-RSV-A NAbs and anti-RSV-B NAbs, respectively. In addition, although the seropositive rates and NAb levels were not associated with the blood type, type AB individuals displayed higher seropositive rates for anti-RSV-A NAbs with high titer (≥ 288) and anti-RSV-B NAbs, especially those with moderate titer (≥ 72 to288). The seropositive rates and titers were comparable between anti-RSV-A NAbs and anti-RSV-B NAbs in the AB blood type group. Interestingly, only when the NAb titer of the serum to RSV-A was not less than 288, was it not less than 18 to RSV-B, and vice versa. These results would be helpful for a better understanding of the human serum NAb responses to RSV-A and RSV-B.

Background: Respiratory tract infection (RTI) is a common disease among children of all ages that causes high hospitalization and mortality rates. Infection with more than one pathogen has been reported in RTI; however, the association of the pathogen spectrum in upper and lower respiratory tract infections remains unclear. Methods: A prospective study was conducted during February to October 2016. Fifty-five nasopharyngeal swabs (NPS) and 30 bronchoalveolar lavage fluid (BALF) samples from 55 hospitalized children aged less than 14 years (mean age 40 months) and diagnosed with an RTI were collected. All samples were detected for 18 respiratory pathogens using the Filmarray assay, real-time PCR, or nested PCR methods. Detection results and clinical characteristics of all cases were analyzed using chi-square and t tests. Results: Forty-one of 55 (74.5%) NPS obtained from children were positive for at least one pathogen by the Filmarray assay. Of these cases, 53.7% (22/41) were co-infected. The most commonly detected pathogen was rhinovirus (RV), followed by Mycoplasma pneumoniae (MP) and respiratory syncytial virus (RSV). Infection by both RV and MP was the most frequently observed pattern of co-infection. Similar results were observed using real-time PCR. The pathogens in the NPS from 76.6% of cases detected by Filmarray and 80.0% of cases by real-time PCR included all the pathogens detected in the BALF sample from the same individual. The Filmarray assay showed an 80% concordance rate with real-time PCR and had a turnaround time of less than 1.2 h. No significant differences were observed between the association of single-infection and co-infection with clinical characteristics, neither by Filmarray nor real-time PCR. Conclusion: The spectrum of pathogens is mostly concordant in the upper and lower respiratory tract. Collecting NPS for detection can be a non-invasive and more convenient option compared with BALF. Although co-infection is common in children with an RTI, the clinical significance of co-infection remains unclear and warrants further analysis. Keywords: Respiratory tract infection, Children, Pathogen, Filmarray assay

Monosomy 7 is generally considered as an acquired cytogenetic abnormality within hematopoietic cells, and indicates an especially high risk of progression to bone marrow failure, myelodysplastic syndrome (MDS) or juvenile myelomonocytic leukemia (JMML). We report a case of a 6-month-old female infant with mosaic monosomy 7 who presented with clinical and laboratory evidences of immunodeficiency. The patient had suffered from recurrent respiratory infections since she was born. Peripheral blood lymphocyte subsets revealed an extremely low level of CD19+ B lymphocytes (0.3∼0.8%, normal range: 6.4∼22.6%) and a decreased CD4/CD8 ratio (0.67∼1.12, normal range: 1.4∼2.0). Decreased serum levels of IgG (1.53 g/L, normal range: 4.09∼7.03 g/L), IgA (0.10 g/L, normal range: 0.21∼0.47 g/L) and IgM (0.26 g/L, normal range: 0.33∼0.73 g/L) were detected, while complements were normal. Excepting transient neutropenia, routine blood tests were within normal limits. Clinical exome sequencing identified a de novo mosaic monosomy 7, while no pathogenic mutation associated with immunodeficiency was detected. However, peripheral blood cytogenetic analysis was failure to detect monosomy 7 due to the very few cell mitosis. Subsequent fluorescence in situ hybridization (FISH) identified a mosaic monosomy 7 in 58 cells within a total number of 100 cells, which was consistent with clinical exome sequencing. Therefore, the patient was diagnosed with primary immunodeficiency disease (PID) due to mosaic monosomy 7. Intravenous treatment with multiple antibiotic agents and infusion of gamma globulin could control the patient’s respiratory infections effectively. A better understanding of PIDs will enable effective treatments and prevention of infections in these patients.

Refractory mycoplasma pneumonia (RMPP) is one of the important pathogens of community-acquired pneumonia (CAP) in children. Its treatment is difficult. The aims of this study were to analyze the clinical manifestations, diagnosis, and treatment of 20 cases of RMPP in children in order to provide a reference for the diagnosis and treatment of RMPP.The clinical data of 20 patients with RMPP admitted to the Pediatrics Department of the First Affiliated Hospital of Guangzhou Medical University in the recent three years were retrospectively analyzed. The clinical data of 36 patients with common mycoplasma pneumonia in the same period were compared. The clinical manifestations, laboratory examinations, and imaging characteristics of RMPP were discussed. Intrapulmonary and extrapulmonary complications and treatment were also analyzed in order to provide assistance in the diagnosis and treatment of RMPP.There were significant differences between the refractory group and the general group in terms of heat duration, hospitalization time, hypoxemia, lung rales, CRP, ESR, PCT, LDH, ALT, PLT, WBC, D dimer and other laboratory examinations, intrapulmonary and extrapulmonary complications, and treatment (all P0.05). There was no significant difference in the age, sex, and wheezing between the two groups (P0.05).Long duration of fever, tachycardia, and lung rale protrusion may be the clinical characteristics of RMPP. Unilateral pulmonary shadow and atelectasis should be paid more attention, which may be a high-risk factor for the development of RMPP. The inflammation index of RMPP cases increased and there were many complications inside and outside the patients' lungs. It was necessary to give enough macrolides to fight the infection by using Glucocorticoid and Intravenous immunoglobulin reasonably while liver, heart, and fiberoptic bronchoscopy was completed to improve the effectiveness of the diagnosis and treatment.

This paper addresses low power design approaches for passive RFID transponder. It proposes a novel low power energy supply circuit, which includes amplitude limiter, rectifier circuit, analog power supply circuit, digital power supply circuit and high voltage power supply circuit. The simulation and measurement results show that proposed voltage rectifier, amplitude limiter and power supply circuit with low voltage checking can provide stable power supply voltage with a small input power and high conversion efficiency. It has been applied to a passive transponder chip design, which was fabricated successfully based on 0.35 μm CMOS process.

A variety of cluster analysis techniques exist to group objects having similar characteristics. While there have been recent advances in algorithms for clustering data, some are unable to handle uncertainty in the clustering process while others have stability issues. This paper proposes a new algorithm for clustering data based on rough set theory, which has the ability to handle the uncertainty in the clustering process.