In-depth study of the components of polymyxins is the key to controlling the quality of this class of antibiotics. Similarities and variations of components present significant analytical challenges. A two-dimensional (2D) liquid chromatography-mass spectrometr (LC-MS) method was established for screening and comprehensive profiling of compositions of the antibiotic colistimethate sodium (CMS). A high concentration of phosphate buffer mobile phase was used in the first-dimensional LC system to get the components well separated. For efficient and high-accuracy screening of CMS, a targeted method based on a self-constructed high resolution (HR) mass spectrum database of CMS components was established. The database was built based on the commercial MassHunter Personal Compound Database and Library (PCDL) software and its accuracy of the compound matching result was verified with six known components before being applied to genuine sample screening. On this basis, the unknown peaks in the CMS chromatograms were deduced and assigned. The molecular formula, group composition, and origins of a total of 99 compounds, of which the combined area percentage accounted for more than 95% of CMS components, were deduced by this 2D-LC-MS method combined with the MassHunter PCDL. This profiling method was highly efficient and could distinguish hundreds of components within 3 h, providing reliable results for quality control of this kind of complex drugs.

Objective:To evaluate the potential value of 18×10 3 translocator protein (TSPO) radioligand ( N, N-diethy1-2-(2-(4-(2- 18F-fluoroethoxy) phenyl)-5, 7-dimethylpyrazolo[1, 5-A]pyrimidin-3-yl)acetamide, 18F-DPA-714) PET compared with conventional MR in the detection of autoimmune encephalitis (AE), the correlation with clinical symptoms, and the monitoring of immunotherapy efficacy in patients with AE. Methods:From December 2021 to June 2024, 45 AE patients (17 males, 28 females, age (38.3±17.0) years) diagnosed at Ruijin Hospital, Shanghai Jiao Tong University School of Medicine and 10 healthy volunteers (7 males, 3 females, age (28.7±5.1) years) were enrolled in this prospective study. All participants underwent baseline 18F-DPA-714 PET/MR scans, and 23 of these AE patients underwent further follow-up 18F-DPA-714 PET/MR scans. 18F-DPA-714 PET positivity was defined as having an uptake intensity threshold higher than the mean SUV ratio (SUVR)+ 2 s of the corresponding brain region in healthy controls. MR positivity was defined as abnormal hyperintensity in a specific brain region or multiple brain regions on the T 2 fluid attenuated inversion recovery (FLAIR). The positive detection rates of 18F-DPA-714 PET and MR was analyzed using McNemar χ2 test, and the differences in the uptake intensity (SUVR) of 18F-DPA-714 between symptomatic and non-symptomatic groups, and between remission and non-remission groups after immunotherapy were compared using independent-sample t test or Wilcoxon rank sum test. Spearman rank correlation analysis was used to analyze the correlation between the changing rate of SUVR and the changing of the modified Rankin Scale (mRS) score before and after treatment. Results:The positive detecting rate of 18F-DPA-714 PET for AE was significantly higher than that of MR (73.3%(33/45) vs 35.6%(16/45); χ2=11.56, P=0.001). The cerebellar SUVR of ataxia patients was significantly higher than that of asymptomatic patients (1.22(1.06, 1.33) vs 1.08(0.99, 1.20); Z=-2.14, P=0.034). Follow-up imaging showed that the SUVR of patients in the remission group after immunotherapy was significantly lower than that in the non-remission group ((-15.19±10.17)% vs (14.26±13.36)%; t=5.81, P<0.001). There was a significant correlation between the changing rate of SUVR and the changing of the mRS score before and after treatment ( rs=0.65, P<0.001). Conclusion:Compared with conventional MR, 18F-DPA-714 PET has a higher positive detecting rate for AE, and has the potential to reflect the clinical symptoms of AE and monitor the efficacy of immunotherapy.

Objective:To evaluate the potential value of 18×10 3 translocator protein (TSPO) radioligand ( N, N-diethy1-2-(2-(4-(2- 18F-fluoroethoxy) phenyl)-5, 7-dimethylpyrazolo[1, 5-A]pyrimidin-3-yl)acetamide, 18F-DPA-714) PET compared with conventional MR in the detection of autoimmune encephalitis (AE), the correlation with clinical symptoms, and the monitoring of immunotherapy efficacy in patients with AE. Methods:From December 2021 to June 2024, 45 AE patients (17 males, 28 females, age (38.3±17.0) years) diagnosed at Ruijin Hospital, Shanghai Jiao Tong University School of Medicine and 10 healthy volunteers (7 males, 3 females, age (28.7±5.1) years) were enrolled in this prospective study. All participants underwent baseline 18F-DPA-714 PET/MR scans, and 23 of these AE patients underwent further follow-up 18F-DPA-714 PET/MR scans. 18F-DPA-714 PET positivity was defined as having an uptake intensity threshold higher than the mean SUV ratio (SUVR)+ 2 s of the corresponding brain region in healthy controls. MR positivity was defined as abnormal hyperintensity in a specific brain region or multiple brain regions on the T 2 fluid attenuated inversion recovery (FLAIR). The positive detection rates of 18F-DPA-714 PET and MR was analyzed using McNemar χ2 test, and the differences in the uptake intensity (SUVR) of 18F-DPA-714 between symptomatic and non-symptomatic groups, and between remission and non-remission groups after immunotherapy were compared using independent-sample t test or Wilcoxon rank sum test. Spearman rank correlation analysis was used to analyze the correlation between the changing rate of SUVR and the changing of the modified Rankin Scale (mRS) score before and after treatment. Results:The positive detecting rate of 18F-DPA-714 PET for AE was significantly higher than that of MR (73.3%(33/45) vs 35.6%(16/45); χ2=11.56, P=0.001). The cerebellar SUVR of ataxia patients was significantly higher than that of asymptomatic patients (1.22(1.06, 1.33) vs 1.08(0.99, 1.20); Z=-2.14, P=0.034). Follow-up imaging showed that the SUVR of patients in the remission group after immunotherapy was significantly lower than that in the non-remission group ((-15.19±10.17)% vs (14.26±13.36)%; t=5.81, P<0.001). There was a significant correlation between the changing rate of SUVR and the changing of the mRS score before and after treatment ( rs=0.65, P<0.001). Conclusion:Compared with conventional MR, 18F-DPA-714 PET has a higher positive detecting rate for AE, and has the potential to reflect the clinical symptoms of AE and monitor the efficacy of immunotherapy.

Steroid-induced osteonecrosis of the femoral head (SONFH) is avascular necrosis of the femoral head caused by long-erm use of corticosteroids, and its pathogenesis is complex and affected by changes in the dynamic balance of the bone microenvironment. With the deepening of research, the role of bone microenvironment in the pathogenesis of SONFH has been gradually revealed. In the case of excessive use of glucocorticoids (GCs), the bone microenvironment changes significantly, causing imbalance in bone lipid metabolism, microcirculation disorders and disorders of immune regulation, which promotes the increase of the number and activity of osteoclasts, and interferes with the differentiation of osteoblasts and adipoblasts. Through the regulation of PI3K/AKT, OPG/RANKL/RANK, MAPK, JAK/STAT, Hedgehog and other signaling pathways, it eventually leads to osteocyte apoptosis, bone microvascular rupture and destruction of trabecular bone structure, which in turn leads to osteonecrosis, bone density reduction and bone microstructure destruction due to bone microcirculation ischemia, and finally leads to necrosis of the femoral head. This article reviews the role of bone microenvironment homeostasis in GCs-induced ONFH and the regulatory mechanism of bone microenvironment, which is helpful to reveal the pathogenesis of SONFH and provide a theoretical basis for exploring effective intervention strategies.
Humans ; Femur Head Necrosis/physiopathology* ; Animals ; Signal Transduction ; Bone and Bones/metabolism* ; Glucocorticoids/adverse effects* ; Cellular Microenvironment

Neuroinflammatory responses play an important role in the pathogenesis of various diseases, particularly those affecting the central nervous system. Inhibition of neuroinflammation is a crucial therapeutic strategy for the management of central nervous system disorders. The intestinal microbial-gut-brain axis serves as a key regulatory pathway that modulates neuroinflammatory processes. Intestinal flora metabolites such as short-chain fatty acids, indoles and their derivatives, lipopolysaccharides, trimethylamine oxide, and secondary bile acids exert direct or indirect effects on neuroinflammation. Studies have shown that electroacupuncture (EA) modulates the composition of the intestinal microbiota and its metabolites, while also suppressing neuroinflammation by targeting the TLR4/NF- κ B, NLRP3/caspase-1, and microglial cell M2-type transformation pathways. This review discusses the mechanisms by which EA regulates neuroinflammation via intestinal microbiota and its metabolites, providing information and a foundation for further investigation of the precise therapeutic mechanisms of EA in neurological disorders.
Humans ; Gastrointestinal Microbiome ; Electroacupuncture ; Neuroinflammatory Diseases/metabolism* ; Animals

In-depth study of the components of polymyxins is the key to controlling the quality of this class of antibiotics.Similarities and variations of components present significant analytical challenges.A two-dimensional(2D)liquid chromatography-mass spectrometry(LC-MS)method was established for screening and comprehensive profiling of compositions of the antibiotic colistimethate sodium(CMS).A high concentration of phosphate buffer mobile phase was used in the first-dimensional LC system to get the components well separated.For efficient and high-accuracy screening of CMS,a targeted method based on a self-constructed high resolution(HR)mass spectrum database of CMS components was established.The database was built based on the commercial MassHunter Personal Compound Database and Library(PCDL)software and its accuracy of the compound matching result was verified with six known components before being applied to genuine sample screening.On this basis,the unknown peaks in the CMS chromatograms were deduced and assigned.The molecular formula,group composition,and origins of a total of 99 compounds,of which the combined area percentage accounted for more than 95％of CMS components,were deduced by this 2D-LC-MS method combined with the MassHunter PCDL.This profiling method was highly efficient and could distinguish hundreds of components within 3 h,providing reliable results for quality control of this kind of complex drugs.

Drug impurity control is essential for ensuring pharmaceutical quality.In this study,an unknown impurity at relative retention time(RRT)of 0.45 in Torasemide injection was systematically investigated using high performance liquid chromatography-ion trap time-of-flight mass spectrometry(LC-IT-TOF-MS/MS),forced degradation studies,and nuclear magnetic resonance(NMR)spectroscopy,aiming to elucidate its chemical structure,propose a formation mechanism,and establish a control strategy.By analysis of the ultraviolet absorption spectrum and high-resolution MS1 and MS2 data of the impurity,its possible structure was postulated.Subsequently,the target impurity was prepared via forced degradation experiment,and its structure was confirmed by NMR spectroscopy.A detailed analysis of its formation mechanism revealed that Torasemide first hydrolyzed in solution to form Torasemide sulfonamide,and then underwent condensation,dehydration,and cyclization reactions with trace amounts of formaldehyde in the excipient polyethylene glycol(PEG)400 to generate the impurity.It was experimentally proven that the target impurity was related to the residual oxygen content in Torasemide injection.Ultimately,by optimizing the prescription process,the target impurity level was controlled below the individual impurity limit of the final product(≤0.3%).This study provided valuable insights for enhancing the quality control of Torasemide injection.

Transfer-RNA derived small RNA(tsRNA),a re-cently discovered class of non-coding RNA,is produced by ma-ture tRNA or tRNA precursor through the mediation of specific endonucleases.By regulating gene expression at the transcrip-tional and post transcriptional levels and acting as an epigenetic regulator,tsRNA plays an important role in the physiological and pathological processes of many organisms.Therefore,it has gradually become a research hotspot in biomedicine and attracted widespread attention.Moreover,there is increasing evidence that tsRNA is involved in the occurrence and development of many neuropsychiatric diseases through participating in stress re-sponse,cell proliferation and apoptosis,neural development,synaptic plasticity,neuroinflammation and immune regulation,epigenetic regulation,RNA processing,and protein translation regulation.This article mainly discusses the generation,classifi-cation and biological functions of tsRNA,and elaborates on the role and possible mechanisms of tsRNA in neurodevelopment and neuropsychiatric disorders,thereby further revealing the poten-tial of tsRNA as a reliable biomarker and therapeutic target for neuropsychiatric disorders.

Transfer-RNA derived small RNA(tsRNA),a re-cently discovered class of non-coding RNA,is produced by ma-ture tRNA or tRNA precursor through the mediation of specific endonucleases.By regulating gene expression at the transcrip-tional and post transcriptional levels and acting as an epigenetic regulator,tsRNA plays an important role in the physiological and pathological processes of many organisms.Therefore,it has gradually become a research hotspot in biomedicine and attracted widespread attention.Moreover,there is increasing evidence that tsRNA is involved in the occurrence and development of many neuropsychiatric diseases through participating in stress re-sponse,cell proliferation and apoptosis,neural development,synaptic plasticity,neuroinflammation and immune regulation,epigenetic regulation,RNA processing,and protein translation regulation.This article mainly discusses the generation,classifi-cation and biological functions of tsRNA,and elaborates on the role and possible mechanisms of tsRNA in neurodevelopment and neuropsychiatric disorders,thereby further revealing the poten-tial of tsRNA as a reliable biomarker and therapeutic target for neuropsychiatric disorders.