OBJECTIVES: To investigate whether mesenchymal stem cell-derived exosomes (MSC-Exo) alleviate white matter damage (WMD) in neonatal rats by targeting the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3). METHODS: Three-day-old Sprague-Dawley rats were randomly assigned to four groups: Sham, hypoxia-ischemia (HI), MSC-Exo, and MCC950 (NLRP3 inhibitor) (n=24 per group). The WMD model was established by unilateral common carotid artery ligation combined with hypoxia. Exosomes (1×10⁸ particles/μL) were transplanted into the lateral ventricle using stereotaxic guidance. Fourteen days after modeling, hematoxylin-eosin staining was used to observe pathological changes in brain tissue, and transmission electron microscopy was used to assess myelinated axons. Western blotting was performed to detect the expression of myelin basic protein (MBP), NLRP3, caspase-1, and interleukin-1β (IL-1β). Immunohistochemistry was used to measure NLRP3, caspase-1, and IL-1β expression. Twenty-eight days post-modeling, behavioral changes were evaluated using the Morris water maze. RESULTS: In the HI group, marked inflammatory cell infiltration, extensive vacuolation, and decreased numbers of myelinated axons were observed compared to the Sham group. The MSC-Exo group showed reduced inflammatory infiltration, fewer vacuoles, and increased myelinated axons compared to the HI group, while the MCC950 group showed nearly normal cell morphology. Compared to the Sham group, the HI group exhibited decreased MBP expression, fewer platform crossings, shorter time in the target quadrant, increased expression of NLRP3, caspase-1, and IL-1β, and longer escape latency (all P<0.05). Compared to the HI group, the MSC-Exo and MCC950 groups showed increased MBP expression, more platform crossings, longer target quadrant stay, and reduced NLRP3, caspase-1, and IL-1β expression, as well as shorter escape latency (all P<0.05). CONCLUSIONS MSC-Exo may attenuate white matter damage in neonatal rats by targeting the NLRP3 inflammasome and promoting oligodendrocyte maturation.
Animals ; NLR Family, Pyrin Domain-Containing 3 Protein/antagonists & inhibitors* ; Rats, Sprague-Dawley ; White Matter/pathology* ; Inflammasomes/physiology* ; Rats ; Animals, Newborn ; Mesenchymal Stem Cells ; Interleukin-1beta/analysis* ; Male ; Caspase 1/analysis* ; Hypoxia-Ischemia, Brain/therapy* ; Myelin Basic Protein/analysis*

Objective To investigate the effect of vancomycin on neonatal sepsis and its clinical effect . Methods The clinical data of 67 children with methicillin resistant Staphylococcus aureus (MRSA) infection and septicemia treated in the hospital from January 2010 to January 2017 were reviewed .The children were treated with ceftazidime+piperacillin/sulbactam when they did not diagnosed with MRSA infection .The chil-dren were treated with vancomycin when they diagnosed with MRSA infection .The immunological and inflam-matory indexes of children before and after vancomycin treatment were compared ,and the clinical effects and adverse reactions were evaluated .Results After vancomycin treatment ,the serum IgG and NK cell activities in 67 children were significantly higher than those before vancomycin treatment (P<0 .05) ,the level of IgM in children was lower than that before treatment ( P< 0 .05) .After treatment ,the serum levels of IL-6 ,IL-8 , IL-2 ,sIL-2R ,CRP ,TNF-α,PCT ,WBC in 67 children were significantly lower than those before treatment (P<0 .05) .The total effective rate of vancomycin treatment was 89 .55％ ,which was higher than that without vancomycin treatment (58 .21％ ,P< 0 .05);the occurrence of adverse reactions before and after treatment with vancomycin were 19 .40％ and 23 .88％ ,and the difference was not statistically significant (P>0 .05);the children of two groups did not appear serious adverse reactions during treatment ,they were treated by symp-tomatic treatment or respite medication ,and continue treated after symptom relief .Conclusion Vancomycin in the treatment of neonatal septicemia caused by M RSA infection can significantly improve the immune level of children ,reduce the degree of systemic inflammatory response ,and the treatment effect is better .