Distribution of bacteria infected by metagenomic sequencing technology in maxillofacial space / 华西口腔医学杂志

OBJECTIVES@#This study aimed to compare and analyze the consistency and difference between metageno-mic next-generation sequencing (mNGS) and conventional bacterial culture in the detection of pathogenic microorganisms in maxillofacial space infection, as well as to provide a new detection method for the early clinical identification of pathogenic bacteria in maxillofacial space infection.@*METHODS@#The clinical data of 16 patients with oral and maxillofacial space infections in the First Affiliated Hospital of Zhengzhou University from March 2020 to June 2020 were collected. mNGS and conventional bacterial culture methods were used to detect pus. We then analyzed and compared the test results of the two methods, including the test cycle, positive detection rate, anaerobic bacteria, facultative anaerobes and aerobic bacteria detection rates, distribution of pathogenic bacteria, relative species abundance, and resistance genes.@*RESULTS@#The average inspection period of mNGS was (18.81±3.73) h, and the average inspection period of bacterial culture was (83.25±11.64) h, the former was shorter than the latter (@*CONCLUSIONS@#Compared with conventional bacterial culture, mNGS has the characteristics of short test time, high sensitivity, and high accuracy. Thus, it is a new detection method for the early identification of pathogenic bacteria in maxillofacial space infection and is beneficial to the early clinical diagnosis and treatment of the disease.

Bone Marrow Mesenchymal Stem Cells Express Neurotrophic Factores and Protect Neural Stem Cells / 中国康复理论与实践

@#ObjectiveTo investigate bone marrow mesenchymal stem cells(BMSC) express brain derived neurotrophic factor(BDNF) and nerve growth factor(NGF) and their protective effect for neural stem cells (NSCs).MethodsBMSC were obtained from rat tibiae and femurs and centrifuged with Ficoll. The passage 3 cells were chosen to make immunocytochemical stain for CD44, CD71 and CD45. The expression of BDNF and NGF was detected in BMSC with RT-PCR, as well as in the media with ELISA. The media that cultured BMSC were collected as BMSC condition media. NSCs were obtained from cerebral cortex of new-born rat and cultured in vitro. After different ratio of BMSC condition midia were added, NSCs were induced to apoptosis with heat-shock, then NSCs were dyed with Annexin V-FITC/PI apoptosis kit and apoptosis rates were tested with flow cytometry. ResultsBMSC were CD44(+), CD45(-), CD71(+) and expressed BDNF and NGF mRNA. BDNF and NGF could be tested in the media of cultured BMSC and increase with cultured time. BMSC condition media could reduce the ratio of heat-induced apoptosis of NSCs, and more BMSC condition media showed better effect. ConclusionBMSC can express neurotrophic factores and protect neural stem cells from heat-induced apoptosis.