Application of metagenomic next-generation sequencing of bronchoalveolar lavage fluid in the diagnosis and treatment of refractory pneumonia in children / 中国当代儿科杂志

OBJECTIVES@#To investigate the clinical application of metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF) in the etiological diagnosis and treatment of refractory pneumonia (RTP) in children.@*METHODS@#A retrospective analysis was performed on 160 children with RTP who were admitted to the Department of Pediatric Internal Medicine, Maternal and Child Health Hospital of Inner Mongolia Autonomous Region, from January 2020 to March 2023. According to whether mNGS was performed, they were divided into two groups: mNGS (n=80) and traditional testing (n=80). All children received the tests of inflammatory markers and pathogen tests after admission. Traditional pathogenicity tests included microbial culture (sputum specimen collected by suction tube), nucleic acid detection of respiratory pathogens, and serological test (mycoplasma, tuberculosis, and fungi). For the mNGS group, BALF specimens were collected after bronchoscopy and were sent to the laboratory for mNGS and microbial culture. The two groups were analyzed and compared in terms of the detection of pathogens and treatment.@*RESULTS@#Compared with the traditional testing group, the mNGS group had a significantly higher detection rate of pathogens (92% vs 58%, P<0.05), with more types of pathogens and a higher diagnostic rate of mixed infections. Compared with the traditional testing group, the mNGS group had a significantly higher treatment response rate and a significantly lower incidence rate of complications during hospitalization (P<0.05). Treatment was adjusted for 68 children in the mNGS group according to the results of mNGS, with a treatment response rate of 96% (65/68) after adjustment.@*CONCLUSIONS@#Compared with traditional pathogen tests, BALF mNGS can significantly improve the detection rate of pathogens and find some rare pathogens. In clinical practice, when encountering bottlenecks during the diagnosis and treatment of children with RTP, it is advisable to promptly perform the mNGS to identify the pathogens.

Bone marrow mesenchymal stem cells to repair the reproductive system of male azoospermia rats / 中华男科学杂志

<p><b>OBJECTIVE</b>To study the ability of bone marrow mesenchymal stem cells (BMSCs) to repair the internal environment of the testis in male azoospermia rats.</p><p><b>METHODS</b>We established azoospermia models in 22 six-week-old male SD rats by intraperitoneal injection of busulfan at 20 mg per kg body weight. We transplanted allogeneic rat BMSCs (rBMSCs) into the testicular seminiferous tubules of the model rats and, 30 days after transplantation, observed the composition and structure of the seminiferous tubular cells by HE staining and detected the expressions of CD44, CD106, and c-kit in the rBMSCs by immunohistochemistry.</p><p><b>RESULTS</b>The number of epididymal sperm was significantly reduced in the model rats as compared with the normal controls (P < 0.01). CD44 and CD106, but not c-kit, were expressed in the isolated rBMSCs. At 30 days after transplantation of rBMSCs, lots of new cells were observed in the seminiferous tubules, some expressing CD106 and some expressing the germ cell surface marker c-kit.</p><p><b>CONCLUSION</b>BMSCs can transdifferentiate into germ cells and repair the damaged seminiferous tubules of sterile rats.</p>