Analysis of Clinical Characteristics and Risk Factors of Plastic Bronchitis in Children With Mycoplasma pneumoniae Pneumonia.

Objective: To analyze the clinical characteristics of plastic bronchitis (PB) in children with Mycoplasma pneumoniae pneumonia (MPP) in order to explore its risk factors. Methods: A retrospective analysis was performed in MPP children receiving bronchoscopy admitted to department of respiratory medicine in Shanghai Children's Hospital from January 2018 to December 2020. According to the bronchoscopic findings, the patients were divided into PB group and non-PB group. The clinical manifestations, laboratory examination, etiology, treatment methods and outcomes of the children were analyzed. Logistic regression was used to analyze the risk factors for PB in children with MPP. Results: A total of 296 children with MPP were enrolled in the study, including 42 (14.2%) children in the PB group and 254 (85.8%) children in the non-PB group. There was no difference in the ratios of gender, age, proportion of fever, cough, wet rales, and wheezing rales between the two groups (P > 0.05). The univariate analysis showed that there were significant differences between the PB group and the non-PB group in LDH, D-dimer, CD3+CD4+(%), CD3+CD4+/CD3+CD8+, CD3 count, CD4 count, CD8 count, complement 3, IL8, IL-1ß, IL-2, IL-10 (P < 0.05). The multivariate logistic regression analysis showed that fever duration > 12 d, IL-8 > 2,721.33 pg/ml, LDH > 482 U/L and complement 3 <1.02 g/L were independent risk factors for PB in children with MPP. Conclusions: Children with PB caused by MPP have protracted fever, a strong inflammatory response and immune function disturbance.

Analysis of Clinical Characteristics and Risk Factors of Severe Adenovirus Pneumonia in Children.

Objective: To analyze the clinical characteristics of adenovirus pneumonia (ADVP) in children and explore risk factors for severe ADVP. Methods: Clinical data from 7,008 hospitalized children with community-acquired pneumonia and 211 with ADVP were retrospectively analyzed between July 2014 and June 2019. Eighty-six patients were diagnosed with severe pneumonia, and related risk factors were analyzed. Results: ADVP accounts for 3.01% (211/7008) of CAP in hospitalized children. Among 211 patients, 167 (64.9%) children aged 1-5 years old, and the onset was in winter and spring for 126 (59.7%) children. All patients had cough, and 116 (92.8%) patients with mild cases and 82 (95.4%) patients with severe cases had varying degrees of fever. The duration of fever in the severe ADVP group and mild ADVP group was 7.3 and 5.4 days, respectively. The average hospital stays were 9.8 and 5.8 days, respectively. There was no significant difference in the levels of WBC and ESR between the two groups, but the levels of N%, CRP, PCT and LDH in children with severe ADVP were significantly higher than those in the mild ADVP group. The univariate analysis showed that there were significant differences between the severe ADVP group and the mild ADVP group in ≥7 days of fever and high IgE (P < 0.05). There was no significant difference in sex, age, onset season, mycoplasma infection, bacterial infection between the two groups (P > 0.05). The multivariate logistic analysis showed that ≥7 days of fever and high IgE were independent risk factors for severe ADVP (P < 0.05). Conclusions: Children with severe ADVP have long fever duration, a strong inflammatory response and immune function disturbance. Fever duration (≥7 days) and high IgE were independent risk factors for severe ADVP.

A case report of bronchial pleomorphic adenoma in a child in China.

BACKGROUND: Paediatric cases of pleomorphic adenoma of the bronchus are rare in clinical practice, despite pleomorphic adenoma being the most common histological form of salivary gland neoplasm. To date, no such cases have been reported in China. CASE PRESENTATION: We report a case of pleomorphic adenoma of the bronchus in a 10-year-old child with no obvious positive signs on examination. Chest-enhanced computed tomography and bronchoscopy showed a large white mass in the right principal bronchus. The patient was treated by bronchial mass resection. Biopsy confirmed the diagnosis of pleomorphic adenoma. CONCLUSIONS: We not only describe a rare benign bronchial tumour in children but also demonstrate the successful use of surgery as a radical cure for pleomorphic adenoma.

Safety of ceftriaxone in paediatrics: a systematic review.

OBJECTIVE: To determine the safety of ceftriaxone in paediatric patients and systematically evaluate the categories and incidences of adverse drug reactions (ADRs) of ceftriaxone in paediatric patients. METHODS: We performed a systematic search in Medline, PubMed, Cochrane Central Register of Controlled Trials, EMBASE, CINAHL, International Pharmaceutical Abstracts and bibliographies of relevant articles up to December 2018 for all types of studies that assessed the safety of ceftriaxone in paediatric patients aged ≤18 years. RESULTS: 112 studies met the inclusion criteria involving 5717 paediatric patients who received ceftriaxone and reported 1136 ADRs. The most frequent ADRs reported in prospective studies were gastrointestinal (GI) disorders (37.4 %, 292/780), followed by hepatobiliary disorders (24.6%, 192/780). Serious ADRs leading to withdrawal or discontinuation of ceftriaxone were reported in 86 paediatric patients. Immune haemolytic anaemia (34.9%, 30/86) and biliary pseudolithiasis (26.7%, 23/86) were the two major causes. Haemolytic anaemia following intravenous ceftriaxone led to death in 11 children whose primary disease was sickle cell disease. Almost all biliary pseudolithiasis are reversible. However, the incidence was high affecting one in five paediatric patients (20.7%). CONCLUSIONS: GI ADRs are the most common toxicity of ceftriaxone in paediatric patients. Immune haemolytic anaemia and biliary pseudolithiasis are the most serious ADRs and the major reasons for discontinuation of ceftriaxone. Immune haemolytic anaemia is more likely in children with sickle cell disease and may cause death. Ceftriaxone should be used with caution in children with sickle cell disease. TRIAL REGISTRATION NUMBER: CRD42017055428.

[Distribution of pathogenic microorganisms and its relationship with clinical features in children with community-acquired pneumonia].

OBJECTIVE: To study the distribution of pathogenic microorganisms in different genders, age groups and seasons in children with community-acquired pneumonia (CAP) and the relationship between the distribution of pathogenic microorganisms and clinical features. METHODS: A total of 1,155 children with CAP were enrolled, among whom there were 670 boys and 485 girls, with a mean age of 3.1±2.8 years (range: one month to 14 years). Indirect immunofluorescence assay, particle agglutination test, enzyme-linked immunosorbent assay, colloidal gold method. and bacterial culture were applied to determine common respiratory pathogenic microorganisms in sputum, throat swabs, blood samples, bronchoalveolar lavage fluid, and urine. RESULTS: A total of 758 specimens (65.63%) were tested positive by pathogen detection. The top three dominant pathogens were Mycoplasma pneumoniae (MP, 43.64%), bacteria (15.12%), and respiratory syncytial virus (RSV, 9.26%), and the rate of mixed infection was 16.02%. The rates of MP infection between boys and girls with CAP were different (40.8% vs 47.6%; P<0.05). The MP detection rate was the highest in the age group of 6-14 years (77.4%) and the lowest in children younger than 1 year (11.2%), while the detection rates of bacteria and RSV were the highest in children younger than 1 year (21.2% and 17.2%, respectively). The MP detection rate was significantly higher in summer and autumn than in winter and spring, while the detection rates of bacteria and RSV in summer and autumn were significantly lower than those in winter and spring. Among children who were MP positive, fever, chills, cough, crackles were more likely to appear; children with RSV infection were more likely to have wheezes; children with bacterial infection were less likely to have cough. Serum levels of C-reactive protein and procalcitonin were associated with bacterial infection (OR=1.747 and 1.418, respectively; both P<0.05). CONCLUSIONS: MP plays a more and more important role in the pathogenic microorganisms of CAP in children. Prevalence and outbreaks of MP infection among children should be alerted in summer and autumn. There are differences in the detection rate of various pathogenic microorganisms in CAP children with various age groups. The clinical features of children with CAP caused by different pathogenic microorganisms are different.

Influence of induced ciprofloxacin resistance on efflux pump activity of Klebsiella pneumoniae.

OBJECTIVE: The efflux pump (EP) is one of the major mechanisms of antibiotic resistance in Klebsiella pneumoniae. However, there are few reports on the effect of the abuse of antibiotic use on the activity of EPs. To determine whether the use of low efficacy antibiotics has any effect on the activity of EPs and induces drug resistance in K. pneumoniae, we investigated the effect of ciprofloxacin on the activity of EPs in K. pneumoniae strains. METHODS: Sixteen susceptible K. pneumoniae strains were isolated from patients and their minimum inhibitory concentrations (MICs) of ciprofloxacin were measured in the absence and presence of the pump inhibitor carbonyl cyanide m-chlorophenyl hydrazone (CCCP). The strains were then induced with a gradient of ciprofloxacin until the MICs of the strains showed no further increase, to obtain induced resistant strains. The EP activities of the strains before and after induction were compared using EP inhibition and ethidium bromide (EtBr) accumulation assays. RESULTS: The MIC values of the strains were 16‒256 times higher after induction than before induction. In the presence of CCCP, the MIC values of 50% of the induced strains were 2‒4-fold lower than that in the absence of this inhibitor. The EtBr accumulation assay showed that the fluorescence of EtBr in the induced cells was lower than that in the cells before induction. CONCLUSIONS: EPs are widespread in susceptible and drug-resistant K. pneumoniae strains. Induction with ciprofloxacin may increase the activity of EPs in K. pneumoniae. The EtBr accumulation assay is more sensitive than the EP inhibition assay in evaluating the activity of EPs in K. pneumoniae.

A compact model for multi-island single electron transistors.

Multi-island single electron transistor is an important kind of the single electron transistor, which is convenient to realize the controllable room temperature operation. A novel semi-empirical compact model for the Multi-island single electron transistor is proposed. The new approach combines the orthodox theory of the single electron tunneling through single coulomb island and a novel empirical analysis procedure for the chain of multi coulomb islands to solve the current of the whole multi-island single electron transistor. The tunneling rates are calculated based on the orthodox theory for the single electron tunneling. The tunneling currents representing the first splitted peaks in the coulomb oscillation curves are calculated according to the assumption that the currents through all the coulomb islands are equal to each other at the stable states, while the currents representing the other splitted peaks are constructed and merged together according to the empirical analysis. The model is verified by the traditional SET simulator SIMON and shows much faster calculation speed than SIMON. Therefore, the novel compact model is suitable for the large scale MISET circuit simulation.

A novel fabrication method for titania resistive switching device.

The titania showing reversible resistive switching are attractive for today's semiconductor technology in nonvolatile random-access memories. A novel fabrication method for titania resistive switching device with vertical structure is proposed. First, the Pt electrode was fabricated the bottom using conventional photolithography and chemical etching technique. Next, the titania thin films with the thickness about 50 nm was deposited on the bottom electrode by electron beam evaporation (EBE). Then, the trench of photoresist for electrode deposit was etched with mild chemical process to preserve the original structure of titania layer. After that, the platinum was deposited in the trench of photoresist using ion sputter. A final lift-off process to define the Pt top electrodes was performed with acetone in an ultrasonic bath to remove the resist. The resistive bistability was observed in this device. The on-threshold voltage is +1.5 V and the off-threshold voltage is -0.6 V. The resistance ratio between the two stable states of the device including Al electrode is approximately 1 x 10(3), the state is nonvolatile and the retention-time test performed over an hour in sweeping mode measurement. The results indicate the forming and rupture of conductive channel relate to the defects and distributing of oxygen vacancy. This method is low-cost, high-yielding, and easy to implement, which is applicable to the fabrication of nonvolatile memories.