Insights into the molecular mechanism of ParABS system in chromosome partition by HpParA and HpParB.

The ParABS system, composed of ParA (an ATPase), ParB (a DNA binding protein), and parS (a centromere-like DNA), regulates bacterial chromosome partition. The ParB-parS partition complex interacts with the nucleoid-bound ParA to form the nucleoid-adaptor complex (NAC). In Helicobacter pylori, ParA and ParB homologs are encoded as HpSoj and HpSpo0J (HpParA and HpParB), respectively. We determined the crystal structures of the ATP hydrolysis deficient mutant, HpParAD41A, and the HpParAD41A-DNA complex. We assayed the CTPase activity of HpParB and identified two potential DNA binding modes of HpParB regulated by CTP, one is the specific DNA binding by the DNA binding domain and the other is the non-specific DNA binding through the C-terminal domain under the regulation of CTP. We observed an interaction between HpParAD41A and the N-terminus fragment of HpParB (residue 1-10, HpParBN10) and determined the crystal structure of the ternary complex, HpParAD41A-DNA-HpParBN10 complex which mimics the NAC formation. HpParBN10 binds near the HpParAD41A dimer interface and is clamped by flexible loops, L23 and L34, through a specific cation-π interaction between Arg9 of HpParBN10 and Phe52 of HpParAD41A. We propose a molecular mechanism model of the ParABS system providing insight into chromosome partition in bacteria.

Automated deep learning model for estimating intraoperative blood loss using gauze images.

The intraoperative estimated blood loss (EBL), an essential parameter for perioperative management, has been evaluated by manually weighing blood in gauze and suction bottles, a process both time-consuming and labor-intensive. As the novel EBL prediction platform, we developed an automated deep learning EBL prediction model, utilizing the patch-wise crumpled state (P-W CS) of gauze images with texture analysis. The proposed algorithm was developed using animal data obtained from a porcine experiment and validated on human intraoperative data prospectively collected from 102 laparoscopic gastric cancer surgeries. The EBL prediction model involves gauze area detection and subsequent EBL regression based on the detected areas, with each stage optimized through comparative model performance evaluations. The selected gauze detection model demonstrated a sensitivity of 96.5% and a specificity of 98.0%. Based on this detection model, the performance of EBL regression stage models was compared. Comparative evaluations revealed that our P-W CS-based model outperforms others, including one reliant on convolutional neural networks and another analyzing the gauze's overall crumpled state. The P-W CS-based model achieved a mean absolute error (MAE) of 0.25 g and a mean absolute percentage error (MAPE) of 7.26% in EBL regression. Additionally, per-patient assessment yielded an MAE of 0.58 g, indicating errors < 1 g/patient. In conclusion, our algorithm provides an objective standard and streamlined approach for EBL estimation during surgery without the need for perioperative approximation and additional tasks by humans. The robust performance of the model across varied surgical conditions emphasizes its clinical potential for real-world application.

Postoperative Nausea and Vomiting Prediction: Machine Learning Insights from a Comprehensive Analysis of Perioperative Data.

Postoperative nausea and vomiting (PONV) are common complications after surgery. This study aimed to present the utilization of machine learning for predicting PONV and provide insights based on a large amount of data. This retrospective study included data on perioperative features of patients, such as patient characteristics and perioperative factors, from two hospitals. Logistic regression algorithms, random forest, light-gradient boosting machines, and multilayer perceptrons were used as machine learning algorithms to develop the models. The dataset of this study included 106,860 adult patients, with an overall incidence rate of 14.4% for PONV. The area under the receiver operating characteristic curve (AUROC) of the models was 0.60-0.67. In the prediction models that included only the known risk and mitigating factors of PONV, the AUROC of the models was 0.54-0.69. Some features were found to be associated with patient-controlled analgesia, with opioids being the most important feature in almost all models. In conclusion, machine learning provides valuable insights into PONV prediction, the selection of significant features for prediction, and feature engineering.

Harnessing Machine Learning for Prediction of Postoperative Pulmonary Complications: Retrospective Cohort Design.

Postoperative pulmonary complications (PPCs) are significant causes of postoperative morbidity and mortality. This study presents the utilization of machine learning for predicting PPCs and aims to identify the important features of the prediction models. This study used a retrospective cohort design and collected data from two hospitals. The dataset included perioperative variables such as patient characteristics, preexisting diseases, and intraoperative factors. Various algorithms, including logistic regression, random forest, light-gradient boosting machines, extreme-gradient boosting machines, and multilayer perceptrons, have been employed for model development and evaluation. This study enrolled 111,212 adult patients, with an overall incidence rate of 8.6% for developing PPCs. The area under the receiver-operating characteristic curve (AUROC) of the models was 0.699-0.767, and the f1 score was 0.446-0.526. In the prediction models, except for multilayer perceptron, the 10 most important features were obtained. In feature-reduced models, including 10 important features, the AUROC was 0.627-0.749, and the f1 score was 0.365-0.485. The number of packed red cells, urine, and rocuronium doses were similar in the three models. In conclusion, machine learning provides valuable insights into PPC prediction, significant features for prediction, and the feasibility of models that reduce the number of features.

Effects of Sodium Dodecyl Sulfate on the Enzyme Catalysis and Conformation of a Recombinant γ-Glutamyltranspeptidase from Bacillus licheniformis.

The study of interactions between proteins and surfactants is of relevance in a diverse range of applications including food, enzymatic detergent formulation, and drug delivery. In spite of sodium dodecyl sulfate (SDS)-induced unfolding has been studied in detail at the protein level, deciphering the conformation-activity relationship of a recombinant γ-glutamyltranspeptidase (BlrGGT) from Bacillus licheniformis remains important to understand how the transpeptidase activity is related to its conformation. In this study, we examined the enzyme catalysis and conformational transition of BlrGGT in the presence of SDS. Enzymatic assays showed that the transpeptidase activity of BlrGGT was greatly affected by SDS in a concentration-dependent manner with approximately 90% inactivation at 6 mM. Native polyacrylamide gel electrophoresis of SDS-treated samples clearly revealed that the heterodimeric enzyme was apparently dissociated into two different subunits at concentrations above 2 mM. The study of enzyme kinetics showed that SDS can act as a mixed-type inhibitor to reduce the catalytic efficiency of BlrGGT. Moreover, the t1/2 value of the enzyme at 55 °C was greatly reduced from 495.1 min to 7.4 min in the presence of 1 mM SDS. The I3/I1 ratio of pyrene excimer fluorescence emission changed around 3.7 mM SDS in the absence of BlrGGT and the inflection point of enzyme samples was reduced to less than 2.7 mM. The Far-UV CD spectrum of the native enzyme had two negative peaks at 208 and 222 nm, respectively; however, both negative peaks increased in magnitude with increasing SDS concentration and reached maximal values at above 4.0 mM. The intrinsic fluorescence spectra of tryptophan further demonstrated that the SDS-induced enzyme conformational transition occurred at approximately 5.1 mM. Tween 20 significantly suppressed the interaction of BlrGGT with SDS by forming mixed micelles at a molar ratio of 1.0. Taken together, this study definitely promotes our better understanding of the relationship between the conformation and catalysis of BlrGGT.

Study on the protective mechanism of Bawei chenxiang powder containing serum on H9c2 cells injured by oxygen-glucose deprivation / 中国药房

OBJECTIVE To study the protective mechanism of Bawei chenxiang powder containing serum on H9c2 cells injured by oxygen-glucose deprivation （OGD）. METHODS H9c2 cells were divided into blank group， model group and Bawei chenxiang powder low-dose， medium-dose and high-dose groups （the dose of drug containing serum 2.5， 8， 12 g/kg）. H9c2 cells were cultured in vitro to establish OGD model. After intervention with drug-containing serum， survival rate of cell was detected. The cell morphology was observed； the levels of lactate dehydrogenase （LDH）， creatine kinase （CK）， superoxide dismutase （SOD）， catalase （CAT）， respiratory chain complexⅠ （ComplexⅠ）， glutathione peroxidase （GSH-Px） and malondialdehyde （MDA） were detected. The contents of reactive oxygen species （ROS）， mitochondrial membrane potential and apoptosis were also detected. The expressions of oxidative stress-related proteins [Kelch ECH association protein 1 （Keap1）， nuclear factor erythroid 2- related factor 2 （Nrf2）， heme oxygenase 1 （HO-1）， NADH oxidoreductase coenzyme 10 （Ndufa10）， thioredoxin （Trx）] and apoptosis-related proteins [B-cell lymphoma 2 （Bcl-2）， Bcl-2 associated X protein （Bax）， Caspase-3 and cytochrome C （Cytc）] were detected. RESULTS Compared with blank group， the cell morphology of model group was damaged； the levels of LDH， CK and MDA were significantly increased （P＜0.01）， while the levels of CAT， ComplexⅠ， SOD and GSH-Px and mitochondrial membrane potential were significantly decreased （P＜0.01）. The content of intracellular ROS and apoptotic rate were significantly increased （P＜0.01）； the expressions of oxidative stress-related proteins （Keap1， Nrf2， HO-1， Ndufa10 and Trx） and pro- apoptosis proteins （Bax， Caspase-3 and Cytc） were significantly increased （P＜0.05）， while the expression of anti-apoptotic protein Bcl-2 was significantly decreased （P＜0.05）. After administration of Bawei chenxiang powder containing serum， the cell morphology improved， and most of the above indexes were significantly reversed （P＜0.05 or P＜0.01）.CONCLUSIONS Bawei chenxiang powder containing serum E-mail：345783110@qq.com has a good protective effect on H9c2 cells damaged by OGD，the mechanism of which is related to the reduction of oxidative damage and inhibition of cell apoptosis.

Mechanism of Bawei Chenxiang powder in treatment of ischemie heart disease through mitophagy based on network pharmacology / 中国药理学通报

Aim To explore the potential mechanism of Bawei Chenxiang powder against ischemie heart disease (IHD) through mitophagy based on network pharmacology, molecular docking and verification in vitro. Methods The targets of serum constituents of Bawei Chenxiang powder were mined by Swiss target predic-tion, and then the targets related to IHD and mitophagy were selected from Genecards, NCBI and OMIM data-bases to obtain the intersection targets of the three as the potential targets of Bawei Chenxiang powder for the treatment of IHD through mitophagy. Then the "ingre-dients-disease-potential target " network and " protein-protein interaction" (PPI) network were constructed to perform network analysis in order to screen the key ac-tive ingredients and core targets, using Autodock vina software for molecular docking operation. The targets CO function enrichment analysis and KEGG pathway enrichment analysis were analyzed by DAVID databas-es. The effeets of Bawei Chenxiang powder containing serum on celi viability, levels expressions mitophagy and key signaling pathway related protein in H9C2 cells were investigated by hypoxia-induced injury of H9c2 myocardial cells model in vitro. Results The 9 key active compounds and 8 core targets of Bawei Chenxiang powder were screened; molecular docking showed a good binding ability of key active ingredients and core targets. KEGG pathway enrichment analysis showed that the effect of Bawei Chenxiang powder on IHD through mitophagy was related to EGFR, PI3K-Akt, MAPK, FoxO signaling pathway, etc. Celi ex-periments showed that Bawei Chenxiang powder containing serum treatment could significantly improve the survival rate by hypoxia-induced injury in H9c2, the expression of LC3II and p62 were significantly down-regulated, and the expressions of p-PI3K/PI3K and p-AKT/AKT were significantly up-regulated. Conclu-sions Bawei Chenxiang powder plays an anti-IHD role by regulating mitophagy, which may be involved in AKT1, STAT3, MAPK3 and EGFR and other targets, through quercetin, Kaempferol, Naringenin and De-hydrodiisoeugenol as well as other components. Its mechanism may be related to improving PI3K-AKT pathway.

Value of blood lipid parameters in predicting the progression of HBV-related acute-on-chronic pre-liver failure / 临床肝胆病杂志

Objective To investigate the difference in blood lipid parameters between acute-on-chronic pre-liver failure (pre-ACLF) and acute-on-chronic liver failure (ACLF) and the risk factors for disease progression. Methods A retrospective analysis was performed for the related data of 118 patients with ACLF (ACLF group) and 44 patients with pre-ACLF (pre-ACLF group) who were treated in The General Hospital of Western Theater Command from January 2012 to December 2020, including baseline age, albumin, creatinine, routine blood test results, and blood lipids. The independent samples t -test was used for comparison between normally distributed continuous data; and the Mann-Whitney U test was used for comparison between non-normally distributed continuous data; the chi-square test was used for comparison of categorical data between groups. A binary logistic regression analysis was used for multivariate analysis to identify independent predictive factors. The receiver operating characteristic (ROC) curve was used to compare the sensitivity and specificity of related indicators, and Youden index was used to calculate cut-off values. Results Compared with the pre-ACLF group, the ACLF group had significantly lower levels of total cholesterol (TC)[2.02(1.56-2.37) mmol/L vs 3.01(2.57-3.66) mmol/L, Z =5.411, P 0.05). The logistic regression analysis showed that TC (odds ratio [ OR ]=0.003, 95% confidence interval [ CI ]: 0.000-0.068, P < 0.05), LDL ( OR =61.901, 95% CI : 3.354-1142.558, P < 0.05), and WBC ( OR =3.175, 95% CI : 1.097-9.185, P < 0.05) had an independent predictive value, and the ROC analysis showed that the area under the ROC curve of TC was 0.852, the sensitivity of LDL was 0.887, and TC had the best specificity of TC was 0.840. Conclusion There are reductions in blood lipid parameters in the progression from pre-ACLF to ACLF, suggesting that clinicians should pay attention to the changes in lipids in the pre-ACLF stage and adjust the nutritional regimen in a timely manner.

Activation and thermal stabilization of a recombinant γ-glutamyltranspeptidase from Bacillus licheniformis ATCC 27811 by monovalent cations.

The regulation of enzyme activity through complexation with certain metal ions plays an important role in many biological processes. In addition to divalent metals, monovalent cations (MVCs) frequently function as promoters for efficient biocatalysis. Here, we examined the effect of MVCs on the enzymatic catalysis of a recombinant γ-glutamyltranspeptidase (BlrGGT) from Bacillus licheniformis ATCC 27,811 and the application of a metal-activated enzyme to L-theanine synthesis. The transpeptidase activity of BlrGGT was enhanced by Cs+ and Na+ over a broad range of concentrations with a maximum of 200 mM. The activation was essentially independent of the ionic radius, but K+ contributed the least to enhancing the catalytic efficiency. The secondary structure of BlrGGT remained mostly unchanged in the presence of different concentrations of MVCs, but there was a significant change in its tertiary structure under the same conditions. Compared with the control, the half-life (t1/2) of the Cs+-enriched enzyme at 60 and 65 °C was shown to increase from 16.3 and 4.0 min to 74.5 and 14.3 min, respectively. The simultaneous addition of Cs+ and Mg2+ ions exerted a synergistic effect on the activation of BlrGGT. This was adequately reflected by an improvement in the conversion of substrates to L-theanine by 3.3-15.1% upon the addition of 200 mM MgCl2 into a reaction mixture comprising the freshly desalted enzyme (25 µg/mL), 250 mM L-glutamine, 600 mM ethylamine, 200 mM each of the MVCs, and 50 mM borate buffer (pH 10.5). Taken together, our results provide interesting insights into the complexation of MVCs with BlrGGT and can therefore be potentially useful to the biocatalytic production of naturally occurring γ-glutamyl compounds. KEY POINTS: • The transpeptidase activity of B. licheniformis Î³-glutamyltranspeptidase can be activated by monovalent cations. • The thermal stability of the enzyme was profoundly increased in the presence of 200 mM Cs+. • The simultaneous addition of Cs+and Mg2+ions to the reaction mixture improves L-theanine production.

The lipid components of high-density lipoproteins (HDL) are essential for the binding and transportation of antimicrobial peptides in human serum.

Antimicrobial peptides (AMPs) have been developed for the treatment of bacterial infections, but their applications are limited to topical infections since they are sequestered and inhibited in serum. Here we have discovered that the inhibition of AMPs by human serum was mediated through high-density lipoproteins (HDL) which are known to remove cholesterol from peripheral tissues. The susceptibility of AMPs to HDL varied depending on the degree of hydrophobicity of AMPs and their binding affinities to HDL. The phospholipids, such as phosphatidylcholine, of HDL were essential for AMP-binding. The dynamic binding interactions between AMPs and HDL were mediated through the hydrophobic interactions rather than by ionic strength. Interestingly, some AMPs, such as SMAP29, dissociated from the AMP-HDL complex and translocated to bacteria upon contact, while some AMPs, such as LL37, remained in complex with HDL. These results suggest that HDL binds AMPs and facilitates the translocation of them to the bacteria.

Endovascular Aneurysm Treatment with the Numen Coil Embolization System: A Prospective Randomized Controlled Open-Label Multicenter Noninferiority Trial in China.

OBJECTIVE: We investigated the safety and efficacy of the Numen coil compared with the Axium coil in the treatment of intracranial aneurysms. METHODS: Because CATCH (Coil Application Trial in China) is a prospective randomized controlled open-label noninferiority trial conducted in 10 centers across China, patients who fulfilled the inclusion and exclusion criteria were randomized 1:1 to either a test group (Numen) or a control group (Axium). The primary outcome was based on successful aneurysm occlusion at 6 months follow-up, whereas secondary outcomes included technical success, the recanalization and retreatment rates, and the rate of serious adverse events (SAEs) at 6 months and 12 months follow-up. RESULTS: Between August 2017 and December 2019, 350 patients presenting with 350 aneurysms were enrolled and randomized. Per-protocol analysis showed that the successful aneurysm occlusion rate at 6 months was 91.18% for the test group compared with 91.85% in the control group, with a difference of -0.68% (P = 0.8419), and the overall mortality during the 30-day follow-up period was 1.19% and 1.81% in the test and control group, respectively, showing no significant difference between the 2 groups (P = 0.6837), whereas the SAE incidence during the 12-month follow-up period was 12.50% and 17.47% in the test and control groups, respectively, which was not statistically significant (P = 0.2222). CONCLUSIONS: This trial showed that the Numen coil was noninferior to the Axium coil in terms of intracranial aneurysm embolization and can be considered as a safe and effective coil for treating patients with intracranial aneurysm in clinical practice.

Clinical effect of allogeneic hematopoietic stem cell transplantation in children with hyper-IgM syndrome / 中国当代儿科杂志

OBJECTIVES@#To evaluate the clinical effect of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children with hyper-IgM syndrome (HIGM).@*METHODS@#A retrospective analysis was performed on the medical data of 17 children with HIGM who received allo-HSCT. The Kaplan Meier method was used for the survival analysis of the children with HIGM after allo-HSCT.@*RESULTS@#After allo-HSCT, 16 children were diagnosed with sepsis; 14 tested positive for virus within 100 days after allo-HSCT, among whom 11 were positive for Epstein-Barr virus, 7 were positive for cytomegalovirus, and 2 were positive for JC virus; 9 children were found to have invasive fungal disease. There were 6 children with acute graft-versus-host disease and 3 children with chronic graft-versus-host disease. The median follow-up time was about 2 years, and 3 children died in the early stage after allo-HSCT. The children had an overall survival (OS) rate of 82.35%, an event-free survival (EFS) rate of 70.59%, and a disease-free survival (DFS) rate of 76.47%. The univariate analysis showed that the children receiving HLA-matched allo-HSCT had a significantly higher EFS rate than those receiving HLA-mismatched allo-HSCT (P=0.019) and that the children receiving HLA-matched unrelated allo-HSCT had significantly higher OS, EFS, and DFS rates than those receiving HLA-mismatched unrelated allo-HSCT (P<0.05). Compared with the children with fungal infection after allo-HSCT, the children without fungal infection had significantly higher EFS rate (P=0.02) and DFS rate (P=0.04).@*CONCLUSIONS@#Allo-HSCT is an effective treatment method for children with HIGM. HLA-matched allo-HSCT and active prevention and treatment of fungal infection and opportunistic infection may help to improve the prognosis of such children.

Chromosome segregation in Archaea: SegA- and SegB-DNA complex structures provide insights into segrosome assembly.

Genome segregation is a vital process in all organisms. Chromosome partitioning remains obscure in Archaea, the third domain of life. Here, we investigated the SegAB system from Sulfolobus solfataricus. SegA is a ParA Walker-type ATPase and SegB is a site-specific DNA-binding protein. We determined the structures of both proteins and those of SegA-DNA and SegB-DNA complexes. The SegA structure revealed an atypical, novel non-sandwich dimer that binds DNA either in the presence or in the absence of ATP. The SegB structure disclosed a ribbon-helix-helix motif through which the protein binds DNA site specifically. The association of multiple interacting SegB dimers with the DNA results in a higher order chromatin-like structure. The unstructured SegB N-terminus plays an essential catalytic role in stimulating SegA ATPase activity and an architectural regulatory role in segrosome (SegA-SegB-DNA) formation. Electron microscopy results also provide a compact ring-like segrosome structure related to chromosome organization. These findings contribute a novel mechanistic perspective on archaeal chromosome segregation.

Single-molecule binding characterization of primosomal protein PriA involved in replication restart.

DNA damage leads to stalled or collapsed replication forks. Replication restart primosomes re-initiate DNA synthesis at these stalled or collapsed DNA replication forks, which is important for bacterial survival. Primosomal protein PriA specifically recognizes the DNA fork structure and recruits other primosomal proteins to load the replicative helicase, in order to re-establish the replication fork. PriA binding on DNA is the first step to restart replication forks for proper DNA repair. Using a single-molecule fluorescence colocalization experiment, we measured the thermodynamic and real-time kinetic properties of fluorescence-labeled Gram-positive bacteria Geobacillus stearothermophilus PriA binding on DNA forks. We showed that PriA preferentially binds to a DNA fork structure with a fully duplexed leading strand at sub-nanomolar affinity (Kd = 268 ± 99 pM). PriA binds dynamically, and its association and dissociation rate constants can be determined using the appearance and disappearance of the fluorescence signal. In addition, we showed that PriA binds to DNA forks as a monomer using photobleaching step counting. This information offers a molecular basis essential for understanding the mechanism of replication restart.

Influence of the “Sunshine Kitchen Project” on the standardized operation of catering industry / 上海预防医学

Objective:To analyze the unqualified rate of the observation indicaors before and after the implementation of “Sunshine Kitchen Project” in order to provide reference for improving the management of catering industry. Methods:This study included 415 catering establishments with implementation of the “Sunshine Kitchen Project” as intervention group and 210 catering establishments as control group without the implementation. By combining cohort study with case-control study， the unqualified rate of each observation indicator in intervention group and control group was analyzed. Results:After the intervention of “Sunshine Kitchen Project”， the unqualified rate of seven observation indicators related to operational behavior was significantly reduced， with an overall decrease of 12.44%. There were significant differences among the unqualified rate of large and medium-sized catering units and canteens in the intervention group （P < 0.001）. There was no statistically significant change in the unqualified rate of seven indicators in the control group （P > 0.1）. Compared with the control group before and after the intervention， the reduction of unqualified rate in the intervention group was significantly larger than that in the control group. The overall unqualified rate of the intervention group was significantly lower than that of the control group （P < 0.001）. Conclusion:The project of “Sunshine Kitchen” plays an active role in promoting the standardized operation of catering industry.

Clinical features and prognosis of children with acute leukemias of ambiguous lineage under different diagnostic criteria / 中国当代儿科杂志

OBJECTIVES@#To study the clinical features and prognosis of children with acute leukemias of ambiguous lineage (ALAL) under different diagnostic criteria.@*METHODS@#A retrospective analysis was performed on the medical data of 39 children with ALAL who were diagnosed and treated from December 2015 to December 2019. Among the 39 children, 34 received treatment. According to the diagnostic criteria for ALAL by World Health Organization and European Group for the Immunological Characterization of Leukemias, the 39 children were divided into two groups: ALAL group (@*RESULTS@#The 34 children receiving treatment had a 3-year event-free survival (EFS) rate of 75%±9% and an overall survival rate of 88%±6%. The children treated with acute myeloid leukemia (AML) protocol had a 3-year EFS rate of 33%±27%, those treated with acute lymphoblastic leukemia (ALL) protocol had a 3-year EFS rate of 78%±10%, and those who had no remission after induction with AML protocol and then received ALL protocol had a 3-year EFS rate of 100%±0% (@*CONCLUSIONS@#ALL protocol has a better clinical effect than AML protocol in children with ALAL, and positive MRD after induction therapy suggests poor prognosis. Hyperleukocytosis and adverse genetic changes are not observed in children with myeloid expression, and such children tend to have a good prognosis, suggesting that we should be cautious to take it as ALAL in diagnosis and treatment.

Prognostic significance of measurable residual disease based on multiparameter flow cytometry in childhood acute myeloid leukemia / 中国当代儿科杂志

OBJECTIVES@#To study the prognostic value of measurable residual disease (MRD) for childhood acute myeloid leukemia (AML) by analyzing MRD-guided risk stratification therapy.@*METHODS@#A total of 93 children with AML were prospectively enrolled in this study. Chemotherapy with the 2015-AML-03 regimen was completed according to the risk stratification determined by genetic abnormality at initial diagnosis and MRD and bone marrow cytology after induction therapy I. Multiparameter flow cytometry was used to dynamically monitor MRD and analyze the prognostic effect of MRD on 3-year cumulative incidence of recurrence (CIR) rate, event-free survival (EFS) rate, and overall survival (OS) rate.@*RESULTS@#The 93 children with AML had a 3-year CIR rate of 48%±6%, a median time to recurrence of 11 months (range 2-32 months), a 3-year OS rate of 65%±6%, and a 3-year EFS rate of 50%±5%. After induction therapy I and intensive therapy I, the MRD-positive children had a significantly higher 3-year CIR rate and significantly lower 3-year EFS and OS rates than the MRD-negative children (@*CONCLUSIONS@#MRD has predictive value for the prognosis of children with AML. Based on the MRD-guided risk stratification therapy, reasonable application of chemotherapy may improve the overall prognosis of children with AML.

Effect of thrombotic burden on the clinical outcome of endovascular recanalization in large vessel occlusion stroke / 中华放射学杂志

Objective:To investigate the effect of thrombus burden on the clinical outcome of endovascular recanalization in large vessel occlusive stroke.Methods:Patients with acute anterior circulation occlusion who underwent endovascular treatment within 24 hours after onset in Zhengzhou University People′s Hospital from January 2018 to December 2019 were retrospectively collected. According to the clot burden score (CBS) of DSA, total objectives were divided into CBS≥6 group (24 cases) and CBS<6 group (38 cases). Clinical data of the two groups were collected and the modified Rankin scale (mRS) was used to evaluate the clinical outcome at 90 days after surgery. Independent sample t-test, Wilcoxon rank sum test and χ 2 test were used to compare the clinical data between the two groups. Independent risk factors affecting the clinical outcome were analyzed by binary logistic regression. Results:There were no statistically significant differences in basic demographic data, stroke risk factors and other factors between the CBS≥6 group and CBS<6 group ( P>0.05).The proportion of using tirofiban after surgery in the CBS≥6 group (63.2%, 24/38) was lower than that in the CBS<6 group (87.5%, 21/24) (χ2=4.380, P=0.044). The discharge NIHSS score of the CBS≥6 group was [5.0 (3.3, 7.8) points] lower than CBS<6 group [8.5 (1.8, 14.5) points] ( Z=5.221, P=0.022). The proportion of postoperative mRS 0-2 was (91.7%, 22/24) in the CBS≥6 group higher than CBS<6 group(39.5%, 15/38) (χ2=20.486, P=0.001), there were no statistically significant differences between the two groups ( P<0.05). The results of binary logistics regression analysis showed the CBS groups (OR=0.042, 95%CI 0.007-0.244 , P=0.001) was an independent risk factor affecting good outcome. Subgroup analysis of whether tirofiban was used or not showed there was no statistically significant difference in clinical prognosis between the two groups ( P>0.05). Conclusions:The clinical outcome of CBS≥6 group is significantly better than that of CBS<6 group, and patients with small thrombus burden are more likely to get a good clinical outcome of 90 days.

Characterization of Streptococcus pneumoniae PriA helicase and its ATPase and unwinding activities in DNA replication restart.

DNA replication forks often encounter template DNA lesions that can stall their progression. The PriA-dependent pathway is the major replication restart mechanism in Gram-positive bacteria, and it requires several primosome proteins. Among them, PriA protein - a 3' to 5' superfamily-2 DNA helicase - is the key factor in recognizing DNA lesions and it also recruits other proteins. Here, we investigated the ATPase and helicase activities of Streptococcus pneumoniae PriA (SpPriA) through biochemical and kinetic analyses. By comparing various DNA substrates, we observed that SpPriA is unable to unwind duplex DNA with high GC content. We constructed a deletion mutant protein (SpPriAdeloop) from which the loop area of the DNA-binding domain of PriA had been removed. Functional assays on SpPriAdeloop revealed that the loop area is important in endowing DNA-binding properties on the helicase. We also show that the presence of DnaD loader protein is important for enhancing SpPriA ATPase and DNA unwinding activities.

Structure of the sodium-dependent phosphate transporter reveals insights into human solute carrier SLC20.

Inorganic phosphate (Pi) is a fundamental and essential element for nucleotide biosynthesis, energy supply, and cellular signaling in living organisms. Human phosphate transporter (hPiT) dysfunction causes numerous diseases, but the molecular mechanism underlying transporters remains elusive. We report the structure of the sodium-dependent phosphate transporter from Thermotoga maritima (TmPiT) in complex with sodium and phosphate (TmPiT-Na/Pi) at 2.3-angstrom resolution. We reveal that one phosphate and two sodium ions (Pi-2Na) are located at the core of TmPiT and that the third sodium ion (Nafore) is located near the inner membrane boundary. We propose an elevator-like mechanism for sodium and phosphate transport by TmPiT, with the TmPiT-Na/Pi complex adopting an inward occluded conformation. We found that disease-related hPiT variants carry mutations in the corresponding sodium- and phosphate-binding residues identified in TmPiT. Our three-dimensional structure of TmPiT provides a framework for understanding PiT dysfunction and for future structure-based drug design.