Hyperoxia caused intestinal metabolism disorder in mice / 中华危重病急救医学

OBJECTIVE@#To investigate the effect of hyperoxia on intestinal metabolomics in mice.@*METHODS@#Sixteen 8-week-old male C57BL/6 mice were randomly divided into hyperoxia group and control group, with 8 mice in each group. The hyperoxia group was exposed to 80% oxygen for 14 days. Mice were anesthetized and euthanized, and cecal contents were collected for untargeted metabolomics analysis by liquid chromatography-mass spectrometry (LC-MS) combined detection. Orthogonal partial least square discriminant analysis (OPLS-DA), volcano plot analysis, heat map analysis, and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to analyze the effects of hyperoxia on metabolism.@*RESULTS@#(1) OPLS-DA analysis showed that R2Y was 0.967 and Q2 was 0.796, indicating that the model was reliable. (2) Volcano plot and heat map analysis showed significant statistical differences in the expression levels of metabolites between the two groups, with 541 up-regulated metabolites, 64 down-regulated metabolites, and 907 no differences, while the elevated 5-hydroxy-L-lysine was the most significant differential metabolite induced by high oxygen. (3) KEGG pathway enrichment analysis showed that porphyrin and chlorophyll metabolism (P = 0.005), lysine degradation (P = 0.047), and aromatic compound degradation (P = 0.024) were the targets affected by hyperoxia. (4) Differential analysis of metabolic products through KEGG enrichment pathway showed that hyperoxia had a significant impact on the metabolism of porphyrin and chlorophyll, lysine, and aromatic compounds such as benzene and o-cresol.@*CONCLUSIONS@#Hyperoxia significantly induces intestinal metabolic disorders. Hyperoxia enhances the metabolism of porphyrins and chlorophyll, inhibits the degradation of lysine, and delays the degradation of aromatic compounds such as benzene and o-cresol.

New avenues for systematically inferring cell-cell communication: through single-cell transcriptomics data

For multicellular organisms, cell-cell communication is essential to numerous biological processes. Drawing upon the latest development of single-cell RNA-sequencing (scRNA-seq), high-resolution transcriptomic data have deepened our understanding of cellular phenotype heterogeneity and composition of complex tissues, which enables systematic cell-cell communication studies at a single-cell level. We first summarize a common workflow of cell-cell communication study using scRNA-seq data, which often includes data preparation, construction of communication networks, and result validation. Two common strategies taken to uncover cell-cell communications are reviewed, e.g., physically vicinal structure-based and ligand-receptor interaction-based one. To conclude, challenges and current applications of cell-cell communication studies at a single-cell resolution are discussed in details and future perspectives are proposed.

Evaluation of caudal block with dexmedetomidine mixed with lidocaine for management of perioperative analgesia in children / 中华麻醉学杂志

Objective To evaluate the efficacy of caudal block with dexmedetomidine mixed with lidocaine for management of perioperative analgesia in children. Methods Thirty pediatric patients, aged 2-6 yr, weighing 8-23 kg, scheduled for elective unilateral high ligation of hernial sac, were equally and randomly assigned into either lidocaine group ( group L ) or dexmedetomidine mixed with lidocaine group ( group DL) using a random number table. Each patient received a single caudal dose of 1% lidocaine 1 ml∕kg in group L. Each patient received a single caudal dose of 1% lidocaine 1 ml∕kg mixed with dexmedetomidine 1 μg∕kg in group DL. Postoperative analgesia was assessed using FLACC scale. When FLACC score ≥4, ibuprofen suspension 10 mg∕kg was given orally. The consumption of ibuprofen was recorded within 8 h after operation. The onset time of caudal block and duration of analgesia were recorded, and adverse effects were observed. Results Compared with group L, the onset time of caudal block was significantly shortened, the duration of analgesia was prolonged, and the requirement for ibuprofen was decreased in group L. There was no significant difference in adverse effects between the two groups. Conclusion Addition of dexmedetomidine 1 μg∕kg to caudal lidocaine can significantly optimize the efficacy of caudal block with lidocaine alone for the management of perioperative analgesia in children.

Effect of microRNA-21-5p on hyperoxic acute lung injury in rats / 中国中西医结合急救杂志

Objective To investigate the effects of microRNA-21-5p (miR-21-5p) on hyperoxic acute lung injury (HALI) in rats and provide a theoretical basis for HALI gene therapy. Methods One hundred and sixty Sprague-Dawley (SD) rats were randomly divided into four groups with number table:hyperoxia control group, phosphate buffer saline (PBS) group, blank virus group and miRNA-21-5p group (each, n = 40). The rats in hyperoxia control group were fed directly in the hyperoxia box (oxygen concentration > 90%); in the other three groups, 200 μL PBS, 200μL slow virus and 200μL miRNA-21-5p slow virus were dropped into the nose respectively, and then they were fed in the hyperoxia box. The rats were exposed to hyperoxia in the boxes for 0, 24, 48 and 72 hours in all the groups, and at each time point, 10 rats were taken randomly from each group to perform arterial blood-gas analysis, calculate oxygenation index (OI) and respiratory index (RI). Afterwards the rats were sacrificed by blood-letting from carotid artery under intra-peritoneal anesthesia, and the lung tissues were obtained to measure the left lung wet/dry weight (W/D) ratio, hemotoxylin-eosin (HE) staining was made and the pathological changes of the right lung were observed under light microscope and the pathological score was measured. Results At 0 hour, the OI, RI, lung W/D ratio and the lung tissue pathology score in rats with hyperoxic injury had no statistically significant differences among the four groups (all P>0.05). With the extension of time, the level of OI was gradually reduced, and the levels of RI, pathologic score and W/D ratio of lung tissues were gradually increased. Compared with the hyperoxia control group, in miRNA-21-5p group, the levels of OI were increased significantly at 24, 48 and 72 hours after the exposure to hyperoxia [mmHg (1 mmHg = 0.133 kPa): 24 hours 358.10±29.25 vs. 306.19±37.23, 48 hours 336.67±29.27 vs. 269.70±29.00, 72 hours 323.81±19.05 vs. 203.81±43.40, all P 0.05). Under the optical microscope, along with the prolongation of exposure to hyperoxia, the structure of alveoli was gradually disturbed, their walls fractured and damaged, alveolar septa widened, edematous, infiltrated with inflammatory cells and in part of the rats a small amount of red blood cell exudates could be seen, but the degree of lung pathological injury in miRNA-21-5p group was much milder than that of the other groups. Conclusion The rat persistently exposed to hyperoxia for 24 hours can establish the rat model of HALI successfully, and the miRNA-21-5p can protect the lung tissue from the damage to some degrees in HALI rats.