Angle ß combined with FeNO and FEV1/FVC% for the detection of asthma in school-aged children.

OBJECTIVE: The diagnostic value of angle ß in school-aged children with asthma is unknown. We speculate that angle ß may reflect diversification of the forced expiratory flow (FEF) to some extent. The objective of this study was to assess the diagnostic accuracy of angle ß, FeNO, pulmonary function parameters and their combinations for asthma in school-aged children. METHODS: In total, 248 children participated in this study (140 children with asthma and 108 healthy children). The diagnostic performance of angle ß, FeNO and pulmonary function parameters was determined using receiver operating characteristic (ROC) curves. In the ROC analysis, we used the hold out cross-validation method to avoid overfitting. This study was performed in China and followed the Guidelines for the diagnosis and optimal management of asthma in children (China). RESULTS: 1) In the asthma group, the mean angle ß value was significantly smaller than that in the control group (P < 0.001), but the mean FeNO value was significantly higher than that in the control group (P < 0.001). 2) More acute exacerbation or greater severity corresponded to a smaller angle ß. 3) Among the single indices, the area under the ROC curve of angle ß was the largest (except for FEV1/FVC%). For combined indicators, after cross-verification, the combination of angle ß, FEV1/FVC% and FeNO showed the highest diagnostic accuracy. CONCLUSION: Angle ß combined with FeNO and FEV1/FVC% can improve the diagnostic accuracy for asthma in school-aged children.

Can the Chinese study on the normal range of FeNO in children evaluate standardized asthma treatment efficacy in 6- to 12-year-old children?

Objective: By examining fractional exhaled nitric oxide (FeNO) levels and performing pulmonary function testing, this study explored whether the multicenter study on the normal range of FeNO in children in China can be used to evaluate standardized treatment efficacy in 6- to 12-year-old children with asthma. Methods: A total of 115 children aged 6-12 years old who were first diagnosed with asthma and received standardized asthma treatment from April 2018 to July 2022 were selected. According to the FeNO level at the first visit, the subjects were divided into different high- and low-FeNO groups according to the American Thoracic Society (ATS) guidelines and the Chinese multicenter study recommendations. The consistency of the two grouping methods and the differences between the high- and low-FeNO groups were compared after standardized treatment. The grouping method that was the most suitable for children in the cross group was discussed. Results: (i) There was fair consistency between the Chinese multicenter study recommendations and the ATS guidelines regarding the classification of high- and low-FeNO groups (Kappa = 0.338). (ii) Repeated-measures ANOVA showed that the level of improvement in FVC%, FEV1%, FEF25%, FEF50%, and FeNO in the American high- and low-FeNO groups differed with the duration of therapy (P < 0.05), however, there was no significant difference between the Chinese groups. (iii) FEV1% and FeNO improved more after treatment in the fixed high-FeNO group than in the cross group (P < 0.05). Conclusion: The Chinese multicenter study on the normal range of FeNO in children in China has a limited role in evaluating standardized asthma treatment efficacy in 6- to 12-year-old children. The ATS guidelines are currently recommended for clinical assessment of asthma treatment efficacy.

LncRNA DINOR is a virulence factor and global regulator of stress responses in Candida auris.

The emergent fungal pathogen Candida auris exhibits high resistance to antifungal drugs and environmental stresses, impeding treatment and decontamination1-3. The fungal factors mediating this stress tolerance are largely unknown. In the present study, we performed piggyBac, transposon-mediated, genome-wide mutagenesis and genetic screening in C. auris, and identified a mutant that grew constitutively in the filamentous form. Mapping the transposon insertion site revealed the disruption of a long non-coding RNA, named DINOR for DNA damage-inducible non-coding RNA. Deletion of DINOR caused DNA damage and an upregulation of genes involved in morphogenesis, DNA damage and DNA replication. The DNA checkpoint kinase Rad53 was hyperphosphorylated in dinorΔ mutants, and deletion of RAD53 abolished DNA damage-induced filamentation. DNA-alkylating agents, which cause similar filamentous growth, induced DINOR expression, suggesting a role for DINOR in maintaining genome integrity. Upregulation of DINOR also occurred during exposure to the antifungal drugs caspofungin and amphotericin B, macrophages, H2O2 and sodium dodecylsulfate, indicating that DINOR orchestrates multiple stress responses. Consistently, dinorΔ mutants displayed increased sensitivity to these stresses and were attenuated for virulence in mice. Moreover, genome-wide genetic interaction studies revealed links between the function of DINOR and TOR signalling, an evolutionarily conserved pathway that regulates the stress response. Identification of the mechanism(s) by which DINOR regulates stress responses in C. auris may provide future opportunities for the development of therapeutics.

Genome-wide piggyBac transposon-based mutagenesis and quantitative insertion-site analysis in haploid Candida species.

Invasive fungal infections caused by Candida species are life threatening with high mortality, posing a severe public health threat. New technologies for rapid, genome-wide identification of virulence genes and therapeutic targets are urgently needed. Our recent engineering of a piggyBac (PB) transposon-mediated mutagenesis system in haploid Candida albicans provides a powerful discovery tool, which we anticipate should be adaptable to other haploid Candida species. In this protocol, we use haploid C. albicans as an example to present an improved version of the mutagenesis system and provide a detailed description of the protocol for constructing high-quality mutant libraries. We also describe a method for quantitative PB insertion site sequencing, PBISeq. The PBISeq library preparation procedure exploits tagmentation to quickly and efficiently construct sequencing libraries. Finally, we present a pipeline to analyze PB insertion sites in a de novo assembled genome of our engineered haploid C. albicans strain. The entire protocol takes ~7 d from transposition induction to having a final library ready for sequencing. This protocol is highly efficient and less labor intensive than alternative approaches and significantly accelerates genetic studies of Candida.

Curvilinearity of a Maximum Expiratory Flow-Volume Curve: A Useful Indicator for Assessing Airway Obstruction in Children With Asthma.

BACKGROUND: Lung function parameters are used as signs in the diagnosis and evaluation of asthma; however, their sensitivity and specificity are not ideal. We calculated and combined angle ß with lung function parameters to identify the ideal indicator. OBJECTIVE: We aimed to identify an ideal indicator for evaluating the severity of airway obstruction in children with asthma. METHODS: In total, 151 school-age children diagnosed with asthma were selected as the asthma group, and 106 healthy children were selected as the control group. The subjects were divided into the exacerbation group, chronic persistent group, and clinical remission group. Furthermore, the subjects were classified into mild and moderate groups or severe and critical groups. Angle ß was calculated in each group. A receiver operating characteristic curve analysis was performed to determine the cutoff values of angle ß and lung function parameters that together provided high sensitivity and specificity for airway obstruction evaluation in children with asthma. RESULTS: The mean value of angle ß in the asthma group was significantly smaller than that in the control group (178.18° and 196.72°, respectively, P < .001). More exacerbations or greater severity corresponded to smaller angle ß values (P < .001). The best cutoff value of angle ß was 189.43°, and the area under the receiver operating characteristic curve of angle ß was 0.877, which is greater than the area under the receiver operating characteristic curve of FEV1, forced expiratory flow (FEF) at 75% vital capacity (FEF25%), and FEF at 50% vital capacity (FEF50%), but smaller than the area under the receiver operating characteristic curve of FEF75% and FEV1/FVC%. Interestingly, combining these measures can enhance the sensitivity and specificity in assessing airway obstruction. CONCLUSIONS: Angle ß was a useful indicator for assessing airway obstruction. Furthermore, angle ß combined with FEV1, FEV1/FVC%, FEF25%, FEF50%, and FEF75% can enhance the sensitivity and specificity of airway obstruction evaluations.