Pediatric bronchial Dieulafoy's disease with bronchial artery embolization: two case reports.

Background: Bronchial Dieulafoy's disease (BDD) is a vascular malformation characterized by the presence of a dysplastic artery in the bronchial submucosa. It is very rare in children but potentially fatal due to life-threatening hemoptysis. Case Description: An 8-year-old boy and a 6-year-old girl were referred to our hospital with recurrent moderate to massive hemoptysis. Intraluminal protrusions with a tendency to bleed were found by bronchoscopy in both patients. Computed tomography angiography (CTA) revealed an abnormal bronchial artery in one patient and a small intraluminal nodule with contrast enhancement in the other. An enlarged bronchial artery and bronchial-to-pulmonary fistulae corresponding to the lesion site were detected by bronchial arteriography in both patients. Based on the radiological findings, the diagnosis of BDD was established. Subsequent bronchial artery embolization (BAE) was successful, and no recurrence of hemoptysis was observed during the 15- to 18-month follow-up. Conclusions: Our cases highlighted the importance of considering BDD in the context of hemoptysis and endobronchial protrusion in children. Bronchial arteriography plays a critical role in diagnosis, especially in cases where CTA does not reveal vascular malformations. Early identification is essential as biopsy is contraindicated. BAE may be an appropriate treatment to improve the prognosis of children with BDD.

Characteristics of Lung Microbiota in Children's Refractory Mycoplasma pneumoniae Pneumonia Coinfected with Human Adenovirus B.

BACKGROUND: Both M. pneumoniae and human adenovirus (HAdV) are common causative agents of lower respiratory tract infection in children; nonetheless, the lung microbiota in patients with coinfection of HAdV and M. pneumoniae remain unexplored. METHODS: Thirty-two children, diagnosed with refractory M. pneumoniae pneumonia (RMPP), entered into the one-year study from July 1, 2019 to June 30, 2020. Among them, twenty-one entered into the M. pneumoniae monoinfection (MP) group and eleven entered into the M. pneumoniae and HAdV coinfection (MP&ADV) group. The characteristics of the clinical findings were examined, and the lung microbiota was analyzed by metagenomic next generation sequencing (mNGS). RESULTS: Eleven patients in the MP&ADV group were coinfected with human mastadenovirus species B. The fever days lasted for significantly longer periods in the MP&ADV group than in the MP group (P < 0.05). The percentage of CD16+CD56+ cells was significantly higher in the MP&ADV group than that in the MP group (P < 0.05). There were no significant differences in α-diversity between the MP and MP&ADV groups, but the ß-diversity was clearly higher in the MP&ADV group than that in the MP group (P < 0.05). At the microbial level, the top phylum of the MP BALF microbiota was Tenericutes; in contrast, it was Preplasmiviricota in the MP&ADV BALF. There were significant differences in the relative abundance of Tenericutes and Preplasmiviricota between the two groups (P < 0.001). There was a strong positive correlation between human mastadenovirus B and fever days, M. pneumoniae and level of IgA, and a strong negative correlation between Mycoplasma pneumoniae and PCT. CONCLUSIONS: In RMPP, the BALF microbiota in children with mono M. pneumoniae infection was simpler than those with coinfection with human mastadenovirus B. Prolonged fever days were associated with human mastadenovirus B coinfection.

Highly homogeneous microbial communities dominated by Mycoplasma pneumoniae instead of increased resistance to macrolide antibiotics is the characteristic of lower respiratory tract microbiome of children with refractory Mycoplasma pneumoniae pneumonia.

BACKGROUND: Although researchers have found that the microbiota changed during the lower respiratory tract (LRT) infection, little was known about the association between LRT microbiome and refractory M. pneumoniae pneumonia (RMPP). METHODS: From June 28th, 2019 to March 23rd, 2020, we enrolled fifty-two children diagnosed with RMPP or non-refractory M. pneumoniae pneumonia (NRMPP), and characterized the structure and function of microbiota in the bronchoalveolar lavage fluid (BALF) by metagenomic next generation sequencing (mNGS). RESULTS: Based on Bray-Curtis distance between samples, samples in RMPP group were highly homogeneous, and Shannon index in the RMPP group was much lower than NRMPP group while Simpson index, which presents the degree of dominance, was higher in RMPP group. The dominant taxon with relative abundance greater than 50% was merely Mycoplasma among RMPP and NRMPP patients, but the proportions of other taxonomic distribution were different. M. pneumoniae was the dominant species and occupied almost all niches in the vast majority of RMPP patients, whereas the other genera were dramatically lower. The NRMPP group was more enriched in antibiotic resistance genes (ARGs) than the RMPP group, and also exhibited a greater relative abundance of macrolide antibiotics resistance gene (macB) and fluoroquinolone antibiotic resistance genes (patA-B) in M. pneumoniae genome. In RMPP patients, higher relative abundance of Streptococcus pneumoniae had a strong correlation with increased hospitalization days while higher relative abundance of Streptococcus pneumoniae had a negative correlation with hospitalization days among NRMPP patients. CONCLUSIONS: The microbiota of LRT in children with RMPP was much more homogeneous and simpler than that of the NRMPP group and with lower relative abundance of macrolide antibiotics resistance gene in M. pneumoniae genome. M. pneumoniae was absolutely dominant in the vast majority of RMPP patients. Prolonged hospitalization days was associated with relative abundance of M. pneumoniae in NRMPP patients while it was related with other pathogens' relative abundance (e.g., Streptococcus pneumoniae) in RMPP patients.

Desorption of copper and cadmium from soils enhanced by organic acids.

The adsorption/desorption behavior of copper and cadmium on soils was investigated in this study. The adsorption isotherm of copper and cadmium conformed to Langmuir equation better than Freundlich equation. The effect of ionic strength, pH, and organic acid, including ethylenediamine tetraacetic disodium acid salt (EDTA), citric acid, oxalic acid and tartaric acid, on the desorption of copper and cadmium was studied. The desorption of copper and cadmium increased with the increase of ionic strength, while the desorption decreased with the rise of pH. The desorption of copper and cadmium enhanced by organic acids was influenced by pH. EDTA showed excellent enhancement on the desorption of both copper and cadmium; citric acid demonstrated great enhancement on the desorption of copper but negligible enhancement on the desorption of cadmium; oxalic acid enhanced the desorption of copper only at pH around 6.4 and enhanced the desorption of cadmium in the pH range from 6.4 to 10.7; tartaric acid slightly enhanced the desorption of copper but negligibly enhanced the desorption of cadmium. The desorption mechanism in the presence of organic acids were explained as the competition of complexation, adsorption and precipitation. The net effect determined the desorption efficiency. This study provided guidance for the selection of organic acids to enhance the electrokinetic (EK) remediation of copper and cadmium from contaminated soils.