[Application of metagenomic next-generation sequencing of bronchoalveolar lavage fluid in the diagnosis and treatment of refractory pneumonia in children]. / æ”¯æ°”ç®¡è‚ºæ³¡çŒæ´—æ¶²å®åŸºå› ç»„äºŒä»£æµ‹åºåœ¨å„¿ç«¥éš¾æ²»æ€§è‚ºç‚Žè¯Šæ²»ä¸­çš„åº”ç”¨.

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].

OBJECTIVE: To study the ability of bone marrow mesenchymal stem cells (BMSCs) to repair the internal environment of the testis in male azoospermia rats. METHODS: 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. RESULTS: 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. CONCLUSION: BMSCs can transdifferentiate into germ cells and repair the damaged seminiferous tubules of sterile rats.

[Production of transgenic embryos through nuclear transfer using ovine fetal fibroblasts transferred with foreign genes].

Human ALR gene sequence was amplified by PCR from human total DNA and inserted into pIRES(2)-EGFP vector. The bicistronic eukaryotic expression vector, pIRES-EGFP/ALR, expressing EGFP, Neo(r) and ALR genes was constructed. Sheep fetal fibroblast cells (sEFCs) were transfected with pIRES-EGFP/ALR by the induction of lipofectAMINE(TM). The positive cell clones were selected with medium containing G418 (800 µg/mL). The fluorescence of transgenic cells was examined with a confocal laser scanning microscope. The expression of ALR gene was tested by PCR, RT-PCR and immuno-histochemical staining. The transgenic cells were used as donors for nuclear transfer to enucleated ovine oocytes. Transgenic embryos were tested by confocal laser scanning microscope and immuno-histochemical staining. Results showed that the EGFP and ALR genes linked with IRES were coexpressed simultaneously in sFFCs; the blastocysts formed by nuclear transfer using tranfected donor cells are all transgenic blastocysts. EGFP, ALR and Neo(r) gene were all expressed in the transgenic embryos. In conclusion that a method to construct the positive embryos before pre-implantation which stably express ALR gene by the indication of EGFP expression has been successfully established. The application of this method can simplify the procedure of testing the targets and contribute to the efficiency increasing of transgenic domestic animal production.