The engineering application of microbially induced carbonate precipitation(MICP)is limited by pH-dependent conformational dynamics of urease.Focusing on the α-subunit urease from Sporosarcina pasteurii,this study integrated conductivity experiments and constant-pH molecular dynamics simulations to analyze active site conformational dynamics and catalytic function across pH 3-11.Results showed that under neutral conditions(pH 7-8),key histidine residues(HIS139/HIS249)exhibited minimal dis-placement(＜0.5 ?),the longest hydrogen bond lifetime(＞8 ps),highest conformational stability(root mean square deviation,RMSD:0.15-0.18 nm),and optimal catalytic activity(conductivity change rate:0.03 mS/cm·min-1,CaCO3 precipitation:3.84 g).Extreme pH(pH 3/11)induced structural collapse(displacement up to 1.8 ?)and complete activity loss.Simulations revealed that neutral pH sta-bilizes a protonation-dependent cooperative allosteric network by maintaining active site cavity volume(～120 ?3)and moderate conformational coherence(correlation coefficient～0.8).This work deciphers the molecular mechanism of pH-regulated urease dynamics through protonation states,providing theoreti-cal support for MICP applications in acidic mine tailing remediation and alkaline soil stabilization.

The engineering application of microbially induced carbonate precipitation(MICP)is limited by pH-dependent conformational dynamics of urease.Focusing on the α-subunit urease from Sporosarcina pasteurii,this study integrated conductivity experiments and constant-pH molecular dynamics simulations to analyze active site conformational dynamics and catalytic function across pH 3-11.Results showed that under neutral conditions(pH 7-8),key histidine residues(HIS139/HIS249)exhibited minimal dis-placement(＜0.5 ?),the longest hydrogen bond lifetime(＞8 ps),highest conformational stability(root mean square deviation,RMSD:0.15-0.18 nm),and optimal catalytic activity(conductivity change rate:0.03 mS/cm·min-1,CaCO3 precipitation:3.84 g).Extreme pH(pH 3/11)induced structural collapse(displacement up to 1.8 ?)and complete activity loss.Simulations revealed that neutral pH sta-bilizes a protonation-dependent cooperative allosteric network by maintaining active site cavity volume(～120 ?3)and moderate conformational coherence(correlation coefficient～0.8).This work deciphers the molecular mechanism of pH-regulated urease dynamics through protonation states,providing theoreti-cal support for MICP applications in acidic mine tailing remediation and alkaline soil stabilization.

The pathogenesis of chronic wound healing is complex.It is often difficult to heal due to a long course of disease,difficulty in treatment,and it seriously affects the quality of life in patients.The active ingredients,couplet medicinals,and compound formulas of traditional Chinese medicine(TCM)possess unique advantages in the treatment of chronic wound healing.The phosphatidylinositol 3-kinase/protein kinase B(PI3K/Akt)signaling pathway is extremely critical in the treatment of chronic wound healing by regulating a series of biological processes,including cell apoptosis,angiogenesis,and inflammatory responses.This article reviews the relevant research on the regulation of the PI3K/Akt signaling pathway by TCM to promote chronic wound healing.It has been found that the active ingredients of TCM(such as geniposide,astragaloside,and ginsenosides,etc.),and compound formulas(such as Chonghe ointment,Huanglian ointment,Shirun shaoshang ointment,etc.)mainly reduce inflammatory responses,promote angiogenesis,regulate cell autophagy,and accelerate wound healing by activating the PI3K/Akt signaling pathway;at the same time,there are also a few couplet medicinals(such as Huangqi-Honghua)and compound formulas(such as Xiangpi Shengji ointment)that exert anti-inflammatory effects by inhibiting this signaling pathway,to promote wound healing.

Objective:To investigate the toxic effect of chlorambucil combined with ibrutinib on mantle cell lymphoma(MCL)cell line Jeko-1 and its related mechanism.Methods:The MCL cell line Jeko-1 was incubated with different concentrations of chlorambucil or ibrutinib or the combination of the two drugs,respectively.CCK-8 assay was used to detect the proliferation of the cells,and Western blot was used to measure the protein expression levels of BCL-2,caspase-3,PI3K,AKT and P-AKT.Results:After Jeko-1 cells were treated with chlorambucil(3.125,6.25,12.5,25,50 μmol/L)and ibrutinib(3.125,6.25,12.5,25,50 μmol/L)alone for 24,48,72h respectively,the cell proliferation was inhibited in a time-and dose-dependent manner.Moreover,the two drugs were applied in combination at low doses(single drug inhibition rate＜50％),and the results showed that the combination of two drugs had a more significant inhibitory effect(all P＜0.05).Compared with the control group,the apoptosis rate of the single drug group of chlorambucil(3.125,6.25,12.5,25,50 μmol/L)and ibutinib(3.125,6.25,12.5,25,50 μmol/L)was increased in a dose-dependent manner.The combination of the two drugs at low concentrations(3.125,6.25,12.5 μmol/L)could significantly increase the apoptosis rate compared with the corresponding concentration of single drug groups(all P＜0.05).Compared with control group,the protein expression levels of caspase-3 in Jeko-l cells were upregulated,while the protein expression levels of BCL-2,PI3K,and p-AKT/AKT were downregulated after treatment with chlorambucil or ibrutinib alone.The combination of the two drugs could produce a synergistic effect on the expressions of the above-mentioned proteins,and the differences between the combination group and the single drug groups were statistically significant(all P＜0.05).Conclusion:Chlorambucil and ibrutinib can promote the apoptosis of MCL cell line Jeko-1,and combined application of the two drugs shows a synergistic effect,the mechanism may be associated with the AKT-related signaling pathways.

Objective:To analyze the relationship between serum cystatin C(CysC),β2-microglobulin(β2-MG)and the efficacy of demethylation therapy in patients with acute myeloid leukemia(AML).Methods:A prospective cohort study was conducted on 98 AML patients admitted to the Affiliated Hospital of Inner Mongolia Medical University from February 2019 to January 2022.All patients were treated with decitabine(DAC)+HAG regimen,28 days as a course and treated for 3-4 courses.At the end of each course of treatment,the treatment effect of the patients was evaluated,and the patients who achieved complete remission(CR)transferred to consolidation therapy,while the patients who did not reach CR at the end of the course of treatment were considered as treatment failure.The examination items before treatment include routine blood parameters,serum CysC,and β2-MG,and general clinical data of the patients were collected.According to the statistical results,logistic regression model was used to analyze the relationship between serum CysC,β2-MG and the efficacy of demethylation therapy in AML patients.The ROC curves were drawn,and the predictive efficacy of serum CysC,β2-MG on demethylation therapy in AML patients was evaluated by the area under the curve(AUC).Results:Of the 98 AML patients enrolled in the study,5 cases were excluded during the treatment period,and 93 cases finally completed the chemotherapy courses.Among them,23 patients achieved CR after the initial induction chemotherapy(course 1-2),and 11 patients achieved CR after the re-induction chemotherapy(course 3-4).The success rate of demethylation therapy was 36.56％(34/93).Compared with the patients in treatment success group,patients in treatment failure group had a higher proportion of intermediate-and adverse-risk,lower levels of platelet(PLT)and hemoglobin(Hb),and higher expression levels of serum CysC and β2-MG,all of which were statistically significant(P＜0.05).Logistic regression analysis showed that high expression of serum CysC,β2-MG and adverse-risk were independent risk factors for failure of demethylation treatment in AML patients(OR＞1,P＜0.05).The ROC curves showed that the AUC values of serum CysC,β2-MG alone and combined in predicting the efficacy of demethylation therapy in AML patients were 0.788,0.785 and 0.834,respectively.Conclusion:The failure of demethylation therapy in AML patients is related to the high expression of serum CysC and β2-MG,and detection of serum CysC and β2-MG before treatment can predict the risk of demethylation therapy failure in AML patients.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Objective To investigate the incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75％(27/36);boys accounted for 64％(23/36).Among the 36 neonates,31(86％)had disease onset within 3 days after birth,and 19(53％)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61％)had left cerebral infarction and 13(36％)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75％)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72％)and seizures in 10 neonates(34％).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33％,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44％(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.

Objective This study aimed to investigate the potential relationship between urinary metals copper (Cu), arsenic (As), strontium (Sr), barium (Ba), iron (Fe), lead (Pb) and manganese (Mn) and grip strength. Methods We used linear regression models, quantile g-computation and Bayesian kernel machine regression (BKMR) to assess the relationship between metals and grip strength.Results In the multimetal linear regression, Cu (β=-2.119), As (β=-1.318), Sr (β=-2.480), Ba (β=0.781), Fe (β= 1.130) and Mn (β=-0.404) were significantly correlated with grip strength (P < 0.05). The results of the quantile g-computation showed that the risk of occurrence of grip strength reduction was -1.007 (95％ confidence interval:-1.362, -0.652; P < 0.001) when each quartile of the mixture of the seven metals was increased. Bayesian kernel function regression model analysis showed that mixtures of the seven metals had a negative overall effect on grip strength, with Cu, As and Sr being negatively associated with grip strength levels. In the total population, potential interactions were observed between As and Mn and between Cu and Mn (Pinteractions of 0.003 and 0.018, respectively).Conclusion In summary, this study suggests that combined exposure to metal mixtures is negatively associated with grip strength. Cu, Sr and As were negatively correlated with grip strength levels, and there were potential interactions between As and Mn and between Cu and Mn.

OBJECTIVE: To explore the immunological mechanisms underlying spermatogenetic malfunction in patients with non-obstructive azoospermia (NOA) based on bioinformatics and machine learning, and to screen out the key genes associated with spermatogenesis failure. METHODS: NOA-related datasets were obtained from the GEO database, and the differentially expressed genes identified by differential analysis and weighted gene co-expression network analysis (WGCNA). A model of spermatogenesis scoring was established for analysis of the immunological microenvironment and cell interaction networks related to spermatogenesis failure. The key genes were screened out by machine learning, followed by analysis of their correlation with T cells and macrophages. An NOA mouse model was constructed for validation of transcriptome sequencing. RESULTS: Seventy-five differentially expressed genes were identified for the establishment of the spermatogenesis scoring model. The low spermatogenesis score group showed a higher infiltration of the immune cells, with an increased proportion of T cells and macrophages and a correlation of cell interaction signals with immunity. SOX30, KCTD19, ASRGL1 and DRC7 were identified by machine learning as the key genes related to spermatogenesis, with down-regulated expressions in the NOA group, and their expression levels negatively correlated with the infiltration of T cells and macrophages. The accuracy of the spermatogenesis scoring and machine learning models, as well as the trend of the expression levels of the key genes, was successfully validated with the transcriptome sequencing data on the NOA mouse testis. CONCLUSION The development of NOA is closely associated with enhanced immunological microenvironment in the testis. T cells and macrophages may play important roles in spermatogenesis failure. SOX30, KCTD19, ASRGL1 and DRC7 are potential biomarkers for the diagnosis and treatment of NOA.
Male ; Azoospermia/genetics* ; Machine Learning ; Animals ; Computational Biology ; Mice ; Humans ; Spermatogenesis/genetics* ; Gene Expression Profiling ; Macrophages/immunology* ; Gene Regulatory Networks ; T-Lymphocytes/immunology* ; Transcriptome

As interstitial collagen,type Ⅲ collagen(Col Ⅲ)does not express in normal glomeruli.However,in Col Ⅲ nephropathy,a large amount of Col Ⅲ deposit in the mesangial and subendothelial area of the glomeruli.IgA nephropathy with Col Ⅲ deposition was extremely rare.In this article,we reported two cases of such disease.After treating with immunosuppressive agents or traditional Chinese medicine decoction,the renal function of the two patients remained stable and the urinary protein levels reduced significantly.