Mitochondria, functioning not only as the central hub of cellular energy metabolism but also as semi-autonomous organelles, orchestrate cellular fate decisions through their endogenous mitochondrial DNA (mtDNA), which encodes core components of the electron transport chain. Emerging research has identified microRNAs localized within mitochondria, termed mitochondria-located microRNAs (mitomiRs). Recent studies have revealed that mitomiRs are transcribed from nuclear DNA (nDNA), processed and matured in the cytoplasm, and subsequently transported into mitochondria. mitomiRs regulate mtDNA through diverse mechanisms, including modulation of mtDNA expression at the translational level and direct binding to mtDNA to influence transcription. Aberrant expression of mitomiRs leads to mitochondrial dysfunction and contributes to the pathogenesis of metabolic diseases. Restoring mitomiR expression to physiological levels using mitomiRs mimics or inhibitors has been shown to improve mitochondrial function and alleviate related diseases. Consequently, the regulatory mechanisms of mitomiRs have become a major focus in mitochondrial research. Given that mitomiRs are located in mitochondria, targeted delivery strategies designed for mtDNA can be adapted for the delivery of mitomiRs mimics or inhibitors. However, numerous intracellular and extracellular barriers remain, highlighting the need for more precise and efficient delivery systems in the future. The regulation of mtDNA expression mediated by mitomiRs not only expands our understanding of miRNA functions in post-transcriptional gene regulation but also provides promising molecular targets for the treatment of mitochondrial-related diseases. This review systematically summarizes recent research progress on mitomiRs in regulating mtDNA expression and discusses the underlying mechanisms of mitomiRs-mtDNA interactions. Additionally, it provides new perspectives on precision therapeutic strategies, with a particular emphasis on mitomiRs-based regulation of mitochondrial function in mitochondrial-related diseases.

Aim To explore the improvement effect of Bazi Bushen capsule on thymic degeneration in SAMP6 mice and the possible mechanism.Methods Twenty 12 week old male SAMP6 mice were randomly divided into the model group(SAMP6)and the Bazi Busheng capsule treatment group(SAMP6+BZBS).Ten SAMR1 mice were assigned to a homologous control group(SAMR1).The SAMP6+BZBS group was oral-ly administered Bazi Bushen capsule suspension(2.8 g·kg-1)daily,while the other two groups were orally administered an equal amount of distilled water.After nine weeks of administration,the morphology of the thymus in each group was observed and the thymus in-dex was calculated;HE staining was used to observe the structural changes of thymus tissue;SA-β-gal stai-ning was used to detect thymic aging;flow cytometry was used to detect the proportion of thymic CD3+T cells in each group;Western blot was used to detect the levels of p16,Bax,Bcl-2,and cleaved caspase-3 proteins in thymus;immunofluorescence was applied to detect the proportion of cortical thymic epithelial cells in each group;ELISA was employed to detect IL-7 lev-els in thymus.Results Compared with the SAMP6 group,the thymic index of the SAMP6+BZBS group significantly increased(P＜0.05);the disordered thy-mic structure was significantly improved;the positive proportion of SA-β-gal staining significantly decreased(P＜0.01);the proportion of CD3+T cells apparently increased(P＜0.05);the level of p16 protein signifi-cantly decreased(P＜0.05);the level of Bcl-2 pro-tein significantly increased(P＜0.05),while the lev-el of cleaved caspase-3 protein markedly decreased(P＜0.05);the proportion of cortical thymic epithelial cells evidently increased;the level of IL-7 significantly increased(P＜0.01).Conclusions Bazi Bushen capsule can delay thymic degeneration,inhibit cell ap-optosis in thymus and promote thymic cell development in SAMP6 mice,which may be related to increasing the proportion of cortical thymic epithelial cells and promoting IL-7 secretion.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

This study was aimed at comparing performance differences among three metagenomic sequencing platforms,MGISEQ-2000,Illumina NextSeq 2000,and Ion GeneStudio S5 Plus,to optimize the sequencing process for trace samples.The three sequencing platforms were used to perform high-throughput sequencing on DNA standards and simulated samples.Through analysis of the quality of raw data and microbial detection capabilities,systematic differences among platforms were compared.The sequencing results were optimized for trace samples by incorporation of exogenous nucleic acids during the li-brary preparation process.In terms of data output per batch and base quality,MGISEQ-2000 surpassed the other two plat-forms.Illumina NextSeq 2000 had the lowest proportion of duplicate reads,whereas Ion GeneStudio S5 Plus had the highest proportion,and significant differences were observed across platforms(P＜0.001).In sequencing uniformity,MGISEQ-2000 and Illumina NextSeq 2000 were superior to Ion GeneStudio S5 Plus.MGISEQ-2000 provided a substantial advantage in microbial detection capability(P＜0.001),but the advantage diminished with decreasing bacterial fluid concentration.Ion GeneStudio S5 Plus had the shortest duration for single-batch sequencing.Moreo-ver,for trace samples with DNA content ≤0.05 ng,the experi-mental group(with added exogenous nucleic acids)achieved a higher number of reads than the control group(without exogenous nucleic acids),with a 11.09±8.03 fold increase.In conclu-sion,the different sequencing platforms each had advantages and disadvantages,thus allowing researchers to choose the appro-priate platform according to specific needs.Furthermore,the addition of exogenous nucleic acids improved the microorganism detection efficiency,and provided better support for subsequent diagnosis and evaluation of results.

Objective:To investigate the effect of genetic polymorphism of MTHFR C677T (rs1801133) on methotrexate (MTX) related toxicity in pediatric mature B-cell lymphoma patients. Methods:Fifty-eight intermediate and high risk patients under 18 years of age with mature B-cell lymphoma who received 5 g/m2 MTX (24 h intravenous infusion) in Sun Yat-sen University Cancer Center from August 2014 to December 2021 were included,and their toxicity of high-dose MTX (HD-MTX) were monitored and analyzed. Results:Among the 58 pediatric patients,the number of CC,CT,and TT genotypes for MTHFR C677T was 33,19 and 6,respectively. A total of 101 courses of HD-MTX therapy were counted,of which plasma MTX level>0.2 μmol/L at 48 h post-MTX infusion were observed in 35 courses,≤0.2 μmol/L in 66 courses. Inter-group comparison showed that plasma MTX level>0.2 μmol/L at 48 h post-MTX infusion increased the risk of developing oral mucositis (P<0.05). Compared with wild-type (CC genotype),patients in the mutant group (CT+TT genotype) were more likely to develop myelosuppression,manifested as anemia,leucopenia,neutropenia and thrombocytopenia. However,plasma MTX level at 48 h was not associated with MTHFR C677T gene polymorphism. Conclusion:The risk of developing oral mucositis in children with mature B-cell lymphoma is associated with plasma MTX concentration. Polymorphism of MTHFR C677T gene is not related to plasma MTX concentration in children with mature B-cell lymphoma,but is related to grade Ⅲ to Ⅳ hematological toxicity.

Objective To investigate the application value of low-molecular-weight heparin calcium combined with alprostadil in the treatment of hypoparathyroidism(HP)after thyroid surgery.Methods Sixty patients with HP after thyroid surgery were randomly divided into two groups:study group(30 cases)and control group(30 cases).The study group received low-molecular-weight heparin calcium and alprostadil,along with oral calcium supplements and calcitriol or an intravenous infusion of calcium gluconate,for three consecutive days after surgery.The control group received only oral calcium supplements and calcitriol or intravenous calcium gluconate.The values and changes in parathyroid hormone(PTH),postoperative drainage volume,and postoperative complications were compared between two groups.Results There were no significant difference in PTH levels at 3 days,1 week,1 month,and 6 months after surgery between two groups(P＞0.05).The difference in PTH levels between 3 days and 1 day after surgery was(6.77±2.61)ng/L in study group and(1.29±1.12)ng/L in control group,with a significant difference(P＜0.05).The difference in PTH levels between 1 week and 1 day after surgery was(10.51±3.66)ng/L in study group and(2.65±2.17)ng/L in control group(P＜0.05).There were no significant difference in PTH levels at 1 month,6 months,and 1 day after surgery(P＞0.05).Comparison of postoperative drainage volume:The postoperative drainage volume of study group was(90.07±22.24)ml,and that of control group was(88.20±24.09)ml,with no statistical significance(P＞0.05).There was no significant difference in postoperative complications between two groups(P＞0.05).Conclusion In cases of HP after total thyroidectomy,timely use of low-molecular-weight heparin calcium and alprostadil can accelerate the recovery of PTH and reduce patient numbness,which is safe,effective,and worthy of clinical promotion.

Pulmonary arterial hypertension(PAH)is a severe disease characterized by abnormal pulmonary vascular remodeling and increased right ventricular pressure load,posing a significant threat to patient health.While some pathological mechanisms of PAH have been revealed,the deeper mechanisms of pathogenesis remain to be elucidated.In recent years,bioinformatics has provided a powerful tool for a deeper understanding of the complex mechanisms of PAH through the integration of techniques such as multi-omics analysis,artificial intelligence,and Mendelian randomization.This review focuses on the bioinformatics methods and technologies used in PAH research,summarizing their current applications in the study of disease mechanisms,diagnosis,and prognosis assessment.Additionally,it analyzes the existing challenges faced by bioinformatics and its potential applications in the clinical and basic research fields of PAH in the future.[Chinese Journal of Contemporary Pediatrics,2024,26(4):425-431]

Ten compounds were isolated and purified from ethanol extracts of dried roots bark of Polygala tenuifolia Willd. by various chromatography techniques such as silica gel and Sephadex LH-20. Their structures were identified by analysis of physicochemical properties and spectral data, and determined as β-sitosterol (1), tenuifolin (2), 6-methoxy coumarin (3), 7-phenyl-1-hydroxy-2,3,6-trimethoxyxanthone (4), 1,8-dihydroxy-3,4,7-trimethoxyanthone (5), mangiferin (6), quercetin-3-O-β-D-glucoside (7), rutin (8), syringaldehyde (9), salicylicacid (10). Among them, compounds 3, 4 and 5 were isolated from the genus of Ploygala for the first time and compound 4 was a new xanthone. The acetylcholinesterase inhibitory activities of compounds 3, 4 and 5 were evaluated by Ellman colorimetric method, compounds 3 and 5 exhibited moderate inhibitory activity, compound 4 exhibited weak inhibitory activity.

Objective To investigate the clinical characteristics,treatment methods,and prognosis of a-cute leukemia patients with extramedullary infiltration.Methods The clinical characteristics and treatment methods of 47 acute leukemia patients with extramedullary infiltration admitted to the Affiliated Hospital of Guizhou Medical University from April 2014 to April 2023 were retrospectively analyzed.Subgroup analysis was performed according to whether there was extramedullary infiltration before transplantation,and whether there was isolated extramedullary recurrence after transplantation.Based on this analysis,the patients were di-vided into the pre-transplantation radiotherapy group and pre-transplantation non-radiotherapy group,the post-transplantation radiotherapy group and post-transplantation non-radiotherapy group.According to the treatment methods of central nervous system leukemia(CNSL),the patients were divided into the intrathecal injection group(n=12)and combination of intrathecal injection and radiotherapy group(n=13).The local remission situation,survival duration,and toxic and side effects of radiotherapy and chemotherapy were com-pared.Results For acute leukemia patients with extramedullary infiltration,the overall survival time(OS)in the radiotherapy group was better than that in the non-radiotherapy group(median OS:706 d vs.151 d,P=0.015).Subgroup analysis showed that the OS of the pre-transplantation radiotherapy group was better than that of the pre-transplantation non-radiotherapy group(median OS:592 d vs.386 d,P=0.035).For CNSL,the combination of intrathecal injection and radiotherapy group had a better OS than the intrathecal injection group(median OS:547 d vs.388 d,P=0.045).The event-free survival time(EFS)of the radiotherapy group was better than that of the non-radiotherapy group(median EFS:175 d vs.50 d,P=0.005).The COX pro-portional-hazards model showed that treatment with or without radiotherapy had a significant impact on the OS of acute leukemia patients with extramedullary infiltration.The risk of death in the pre-transplantation non-radiotherapy group was 2.231 times higher than that in the pre-transplantation radiotherapy group(HR=3.231,95％CI:1.021-10.227,P=0.046).Compared with the non-radiotherapy group,the radiother-apy group had a higher local remission and a lower risk of haematological toxicity,infection,and haemorrhage.Conclusion Radiotherapy can rapidly alleviate the local symptoms of acute leukemia complicated with extr-amedullary infiltration,prolong the survival time of these patients,and reduce the risk of hematologic toxicity,infection,and haemorrhage.

AIM To investigate the effects of different compatibility ratios and processing method on the content of rutin,isoquercetin,ferulic acid,quercetin,isotoosendanin,kaempferol,toosendanin,α-pinene,trans-anethole in the combination use of Toosendan Fructus and Foeniculi Fructus,and to explore the optimal compatibility ratio for its use.METHODS The analysis of HPLC-DAD was performed on a 30℃thermostatic ZORBAX SB C18 column(4.6 mm×250 mm,5 μm),with the mobile phase comprising of acetonitrile-0.1%phosphoric acid flowing at 1.0 mL/min in a gradient elution manner,and the use of DAD detector.SPSS 24.0 software was used to analyze the data differences.RESULTS Nine constituents showed good linear relationships within their own ranges(r≥0.999 1),whose average recoveries were 96.19%-103.13%with the RSDs of 1.86%-2.67%.Generally higher total content of nine constituents were detected in the combination use groups when Toosendan Fructus-Foeniculi Fructus were at ratios of 1 ∶ 1,1 ∶ 2,and 2 ∶ 1 than those single uses(P<0.05),and among which the 1 ∶ 1 ratio contributed the highest total content.After salt processing,decreased content of toosendanin and isotoosendanin,α-pinene and trans-anethole(P<0.05,P<0.01)),increased isoquercetin content(P<0.01),and no significant content changes of other ingredients were detected.CONCLUSION Through this method of high accuracy and good reproducibility,we learn that the combination use of Toosendan Fructus and Foeniculi Fructus promotes the dissolution of the nine constituents,and the maximum content is achieved at ratio of 1 ∶ 1.