OBJECTIVE: To explore the effect and mechanism of DNA methyltransferase 1 (DNMT1) knockout on the inhibition of acute myeloid leukemia (AML) by natural killer (NK) cells. METHODS: The peripheral blood NK cells of AML patients and controls were collected, and the mRNA and protein level of DNMT1 were measured by PCR and Western blot, respectively. The DNMT1 knockout mice were constructed to obtain NK^DNMT1-/- cells. The NK cells were stimulated with interleukin (IL)-12, IL-15, and IL-18 to construct memory NK cells, and then the interferon-γ (IFN-γ) levels were measured by ELISA. After co-culturing with memory NK cells and HL60 cells, the killing effect of NK^DNMT1-/- cells on HL60 cells was detected by LDH assay. Then, the HL60 cell apoptosis and NK cell NKG2D level were measured by flow cytometry. The perforin and granzyme B protein levels of NK cells were measured by Western blot. The AML model mice were constructed by injecting HL60 cells into the tail vein, meanwhile, memory NK cells were also injected, and then the mouse weights, CD33 positive rates, and survival time were detected. RESULTS: The mRNA and protein levels of DNMT1 in NK cells of AML patients were significantly higher than those in the control group (both P < 0.01), while the IFN-γ level induced by interleukin was significantly lower than that in the control group (P < 0.05). Compared with NK^DNMT1+/+ cells, the ability of NK^DNMT1-/- cells to secrete IFN-γ after interleukin stimulation was significantly increased (P < 0.05). The killing and apoptosis-inducing effects of NK^DNMT1-/- cells on HL60 cells were significantly stronger than those of NK^DNMT1+/+ cells (both P < 0.05). The NKG2D level and expression of perforin and granzyme B of NK^DNMT1-/- cells were significantly increased compared with NK^DNMT1+/+ cells (all P < 0.05). Compared with AML mice injected with NK^DNMT1+/+ cells, AML mice injected with NK^DNMT1-/- cells showed significantly increased body weight, decreased CD33 positive rate, and prolonged survival time (all P < 0.05). CONCLUSION Knocking out DNMT1 can enhance the inhibitory effect of NK cells on AML, which may be related to enhancing NK cell memory function.
Killer Cells, Natural/metabolism* ; Animals ; Leukemia, Myeloid, Acute ; Humans ; DNA (Cytosine-5-)-Methyltransferase 1 ; Mice ; Mice, Knockout ; HL-60 Cells ; Apoptosis ; Interferon-gamma/metabolism* ; Granzymes/metabolism* ; Perforin/metabolism* ; NK Cell Lectin-Like Receptor Subfamily K/metabolism*

In recent years, gastrointestinal stromal tumors (GIST) have increased incidence and mortality, and most GIST is caused by the activation mutation of the c-KIT gene. Therefore, c-KIT has become a promising therapeutic target of GIST. At present, the drugs approved for the treatment of GIST including imatinib, sunitinib, regorafenib and ripretinib, are mostly prone to developing resistance and accompanied by various degrees of adverse reactions. Therefore, there is an urgent need to develop new c-KIT inhibitors to solve the problem of resistance. In this study, we investigated the anti-tumor effect of a novel c-KIT inhibitor PN17-1 on gastrointestinal stromal tumor GIST-882 cells in vitro. We found that PN17-1 significantly inhibited the proliferation, colony formation and migration ability of GIST-882 cells, and significantly downregulated the protein expression levels of p-c-KIT and its downstream signals p-AKT, p-STAT5 and p-ERK in GIST-882 cells. In addition, PN17-1 induced apoptosis in GIST-882 cells, and the apoptosis may be mainly related to the mitochondrial-dependent endogenous pathway. In conclusion, the novel c-KIT inhibitor PN17-1 is a promising anti-GIST drug, and this study provides new ideas for further development of c-KIT inhibitors in the future.

Severe open tibiofibular fractures account for approximately 28.1% of all open fractures. Among them, Gustilo-Anderson type IIIB/C fractures present significant clinical challenges due to associated bone and soft tissue defects, high infection rates, and risk of amputation. Inadequate preoperative assessment may lead to suboptimal emergency surgical planning or intraoperative complications. Historically, external fixation was often preferred, but this approach has been associated with limitations such as restricted joint mobility, delayed bone union, joint stiffness, and disuse osteoporosis, resulting in poor functional recovery. With advancements of debridement techniques, standardization of antibiotic use, and popularization of early soft tissue coverage, early internal fixation has gained broader acceptance. Nevertheless, controversies persist regarding the choice of fixation method, timing of definitive fixation, use of reamed versus unreamed intramedullary nailing, and necessity of fibular fixation. To standardize the diagnosis and early management of severe open tibiofibular fractures, reduce complication rates, and improve functional recovery, the Society of Microsurgery of the Chinese Medical Association organized a panel of domestic experts to develop the Evidence-based guideline for the diagnosis and early fixation of severe open tibiofibular fractures ( version 2025), using evidence-based methodology. The guidelines provided 12 recommendations covering diagnostic and early fixation strategies of severe open tibiofibular fractures, aiming to provide clinicians with scientifically grounded and standardized guidance.

Objective To explore the effects of the disinfection port position and diameter and disinfectant concentration on the in-situ decontamination of the flow field-based biosafety high efficiency particulate air filter device with the computational fluid dynamics(CFD)method.Methods ANSYS DesignModeler was used to construct five models for the high efficiency particulate air filter device with the disinfection port at the side end in four ones and upper end in the remained one model,with the diameter being 70,100,150,260 and 260 mm respectively;secondly,a standard k-ε turbulence model was applied to simulating the velocity field and concentration field inside the high efficiency particulate air filter device,so as to analyze the influence of the vortex position inside the device and the structure of the device on the disinfection effect and to determine the optimal structure of the device;finally,H2O2 with the concentration of 0.45,0.35 or 0.30 mol/L was selected as the disinectant to investigate the effect of the disinfectant concentration on the disinfection under the optimal device structure.Results Simulation showed that there were vortexes existed the cavity between the filter compression structure and the filter of the high efficiency particulate air filter device.The disinfection effect in case of the disinfection port at the side end was higher than that in case of the disinfection port at the upper end;the diameter of the disinfection port had influences on the disinfection effect,and high-concentration disinfectant was found in the device when the diameter was 100 mm.The optimal structure with the disinfection port at the side end and the diameter of 100 mm was determined for the high efficiency particulate air filter device.An increase in H2O2 concentration was beneficial to improve disinfection without corroding and damaging the device when the in-situ decontamination of the flow field-based biosafety high efficiency particulate air filter device was carried out.Conclusion The characteristics of the internal flow field of the flow field-based biosafety high efficiency particulate air filter device and the influencing factors of the in-situ disinfection effect are revealed,and theoretical references are provided for the optimal design of the device.[Chinese Medical Equipment Journal,2025,46(9):22-27]

Purpose To investigate the sex differences of white matter damage in Alzheimer's disease(AD)and their association with cognitive impairment.Materials and Methods This retrospective study included 88 AD patients(48 females),71 amnestic mild cognitive impairment(aMCI)patients(39 females),and 95 healthy controls(63 females)recruited from the Memory Disorder Clinic at the First Affiliated Hospital of Anhui Medical University from September 2017 to July 2024.High-resolution three-dimensional T1 structure images and diffusion tensor imaging images were all obtained from each participant.The mean diffusivity(MD)and fractional anisotropy(FA)values of each white matter region were obtained,and the two-way ANOVA analysis was conducted to investigate brain regions with interaction effects between groups and sexes,those brain regions were then chosen as regions of interest for further correlation analysis with a series of cognitive scale scores.Results In terms of FA values,the right posterior corona radiata,right anterior limb of the internal capsule and left corticospinal tract showed interaction between sexes and cognitive groups(F=4.764,3.812,5.937,all P<0.05).The FA value of AD group was significantly lower than that of healthy control and aMCI group(all P<0.05),but there was no significant difference between healthy control and aMCI group(except the right anterior limb of the internal capsule,P=0.018).In AD group,FA values were significantly higher in women than in men in the previously described brain regions(all P<0.05),while there was no significant difference in FA values between male and female in healthy control and aMCI groups(except the left corticospinal tract,P<0.001).In terms of MD values,the right anterior limb of the internal capsule,right superior corona radiata and left external capsule showed interaction effect between sexes and cognitive groups(F=8.581,3.680,7.218,all P<0.05).The MD value of AD group was significantly higher than that of aMCI group(P<0.001),and aMCI group was higher than that of healthy control group(all P<0.05).In AD group,the MD values in the above brain regions were significantly higher in males than those in females(all P<0.01),while no significant difference was found between males and females in healthy control and aMCI groups(except for the left external capsule,P<0.05).For correlation analysis,the AD group was dimidiated into two groups by sex,the scores of the Montreal cognitive assessment,the Mini Mental state examination and the verbal fluency test of the female patient group were positively correlated with the FA values of the right posterior corona radiate(r=0.372,P=0.009;r=0.345,P=0.016;r=0.383,P=0.007),while the Mini Mental state examination and the verbal fluency test scores of female AD patient group were negatively correlated with the MD values of the right superior corona radiata(r=-0.360,P=0.012;r=-0.360,P=0.003).Conclusion Compared to the healthy control and MCI groups,white matter damage in AD patients shows sex differences and is associated with general cognitive and language functions impairment in female AD patients.

Aim To identify the underlying target of bullatine A(BA)against rheumatoid arthritis(RA)u-sing limited proteolysis-small molecule mapping(LiP-SMap)drug target proteomics and to provide a scientif-ic basis for clinical application of Aconiti brachypodi Radix in the treatment of RA.Methods LiP-SMap drug target proteomics was employed to perform bioin-formatics analysis for comparing and validating the dif-ferential protein expression after BA intervention.A collagen-induced arthritis(CIA)model was estab-lished in DBA/1 mice using bovine type Ⅱ collagen.The mice were then divided into the CIA model group,methotrexate-positive control group(MTX group),and BA groups(10 mg·kg-1 and 20 mg·kg-1)based on their clinical scores.After drug intervention,the thera-peutic efficacy against RA was assessed by joint index scores and foot thickness measurements.Histopatholog-ical changes in the arthritic joints of CIA mice were e-valuated using hematoxylin and eosin(HE)staining.Enzyme-linked immunosorbent assay(ELISA)was employed to detect inflammatory cytokines interleukin-17(IL-17)and total IgG and IgG3 anti-collagen-spe-cific antibodies levels from the serum of CIA mice.Flow cytometry was used to detect the expression levels of intracellular Th17 cells(IL-17+CD4+T cells)and Th1 cells(IFN-γ+CD4+T cells).Fluorescent quanti-tative PCR was performed to detect the expression of genes related to differential proteins.Results The proteomic analysis identified Serpinb1a as a protein with strong binding affinity to BA,and KEGG enrich-ment analysis indicated IL-17 signaling pathway was a crucial pathway of BA in against RA.BA treatment significantly reduced clinical scores and foot thickness,improved local arthritis symptoms in CIA mice,and al-leviated inflammatory cell infiltration into arthritic joints(P＜0.05).Differential protein validation re-sults showed that BA had strong affinity with Serpinb1a(-5.92 kJ·mol-1)and downregulated the expres-sion of Serpinb1a mRNA.Furthermore,the administra-tion of BA markedly reduced serum IL-17 A levels from CIA mice,inhibited the expression of intracellular IL-17 A and IFN-γ cytokines in splenic CD4+T cells(P＜0.05),and significantly downregulated the transcrip-tional expression of IL-17F(P＜0.05).Conclusion BA exhibits therapeutic effects on collagen-induced arthritis,and its mechanism of action may involve the regulation of Serpinb1a and the IL-17 signaling path-way.

Objective:To investigate the feasibility and clinical effects of ultra early enteral nutrition (≤24 h) in critically ill children supported by extracorporeal membrane oxygenation (ECMO).Methods:A retrospective cohort study was conducted. Clinical data of 43 critically ill children who received ECMO support in the pediatric intensive care unit (PICU) of Shanghai Children′s Hospital from January 2016 to December 2023 were collected, including general information, nutritional support modalities, and enteral nutrition tolerance. Based on the timing of enteral nutrition initiation, patients were divided into the within 24 h enteral nutrition group and the after 24 h enteral nutrition group. Nutritive indicators, nutritional intake, duration of ECMO support, duration of mechanical ventilation duration, and mortality rates were compared between the 2 groups using the two independent sample t test, Mann-Whitney U test, χ2 test and Fisher′s exact test. Results:Among the 43 children, 25 were male and 18 were female, with an age of 47 (18, 97) months. There were no statistically significant differences between the within 24 h enteral nutrition group (21 cases) and the after 24 h enteral nutrition group (22 cases) in terms of age, body mass index Z score, total protein, albumin, hemoglobin levels before ECMO support, duration of ECMO support, duration of mechanical ventilation, length of PICU stay, number of enteral nutrition intolerance events, number of enteral nutrition interruption, or mortality rate (all P>0.05). The protein intake adequacy rate during ECMO support was higher in the within 24 h enteral nutrition group than in the after 24 h enteral nutrition group (0 (0, 21%) vs. 0 (0, 0), U=175.00, P<0.05). Conclusions:Ultra early enteral nutrition is safe for children supported by ECMO. Initiating enteral nutrition within 24 h can increase the proportion of days with adequate protein intake in ECMO children without increasing the occurance of enteral nutrition intolerance or interruptions.

Severe open tibiofibular fractures account for approximately 28.1% of all open fractures. Among them, Gustilo-Anderson type IIIB/C fractures present significant clinical challenges due to associated bone and soft tissue defects, high infection rates, and risk of amputation. Inadequate preoperative assessment may lead to suboptimal emergency surgical planning or intraoperative complications. Historically, external fixation was often preferred, but this approach has been associated with limitations such as restricted joint mobility, delayed bone union, joint stiffness, and disuse osteoporosis, resulting in poor functional recovery. With advancements of debridement techniques, standardization of antibiotic use, and popularization of early soft tissue coverage, early internal fixation has gained broader acceptance. Nevertheless, controversies persist regarding the choice of fixation method, timing of definitive fixation, use of reamed versus unreamed intramedullary nailing, and necessity of fibular fixation. To standardize the diagnosis and early management of severe open tibiofibular fractures, reduce complication rates, and improve functional recovery, the Society of Microsurgery of the Chinese Medical Association organized a panel of domestic experts to develop the Evidence-based guideline for the diagnosis and early fixation of severe open tibiofibular fractures ( version 2025), using evidence-based methodology. The guidelines provided 12 recommendations covering diagnostic and early fixation strategies of severe open tibiofibular fractures, aiming to provide clinicians with scientifically grounded and standardized guidance.

Aim To identify the underlying target of bullatine A(BA)against rheumatoid arthritis(RA)u-sing limited proteolysis-small molecule mapping(LiP-SMap)drug target proteomics and to provide a scientif-ic basis for clinical application of Aconiti brachypodi Radix in the treatment of RA.Methods LiP-SMap drug target proteomics was employed to perform bioin-formatics analysis for comparing and validating the dif-ferential protein expression after BA intervention.A collagen-induced arthritis(CIA)model was estab-lished in DBA/1 mice using bovine type Ⅱ collagen.The mice were then divided into the CIA model group,methotrexate-positive control group(MTX group),and BA groups(10 mg·kg-1 and 20 mg·kg-1)based on their clinical scores.After drug intervention,the thera-peutic efficacy against RA was assessed by joint index scores and foot thickness measurements.Histopatholog-ical changes in the arthritic joints of CIA mice were e-valuated using hematoxylin and eosin(HE)staining.Enzyme-linked immunosorbent assay(ELISA)was employed to detect inflammatory cytokines interleukin-17(IL-17)and total IgG and IgG3 anti-collagen-spe-cific antibodies levels from the serum of CIA mice.Flow cytometry was used to detect the expression levels of intracellular Th17 cells(IL-17+CD4+T cells)and Th1 cells(IFN-γ+CD4+T cells).Fluorescent quanti-tative PCR was performed to detect the expression of genes related to differential proteins.Results The proteomic analysis identified Serpinb1a as a protein with strong binding affinity to BA,and KEGG enrich-ment analysis indicated IL-17 signaling pathway was a crucial pathway of BA in against RA.BA treatment significantly reduced clinical scores and foot thickness,improved local arthritis symptoms in CIA mice,and al-leviated inflammatory cell infiltration into arthritic joints(P＜0.05).Differential protein validation re-sults showed that BA had strong affinity with Serpinb1a(-5.92 kJ·mol-1)and downregulated the expres-sion of Serpinb1a mRNA.Furthermore,the administra-tion of BA markedly reduced serum IL-17 A levels from CIA mice,inhibited the expression of intracellular IL-17 A and IFN-γ cytokines in splenic CD4+T cells(P＜0.05),and significantly downregulated the transcrip-tional expression of IL-17F(P＜0.05).Conclusion BA exhibits therapeutic effects on collagen-induced arthritis,and its mechanism of action may involve the regulation of Serpinb1a and the IL-17 signaling path-way.

Objective To explore the effects of the disinfection port position and diameter and disinfectant concentration on the in-situ decontamination of the flow field-based biosafety high efficiency particulate air filter device with the computational fluid dynamics(CFD)method.Methods ANSYS DesignModeler was used to construct five models for the high efficiency particulate air filter device with the disinfection port at the side end in four ones and upper end in the remained one model,with the diameter being 70,100,150,260 and 260 mm respectively;secondly,a standard k-ε turbulence model was applied to simulating the velocity field and concentration field inside the high efficiency particulate air filter device,so as to analyze the influence of the vortex position inside the device and the structure of the device on the disinfection effect and to determine the optimal structure of the device;finally,H2O2 with the concentration of 0.45,0.35 or 0.30 mol/L was selected as the disinectant to investigate the effect of the disinfectant concentration on the disinfection under the optimal device structure.Results Simulation showed that there were vortexes existed the cavity between the filter compression structure and the filter of the high efficiency particulate air filter device.The disinfection effect in case of the disinfection port at the side end was higher than that in case of the disinfection port at the upper end;the diameter of the disinfection port had influences on the disinfection effect,and high-concentration disinfectant was found in the device when the diameter was 100 mm.The optimal structure with the disinfection port at the side end and the diameter of 100 mm was determined for the high efficiency particulate air filter device.An increase in H2O2 concentration was beneficial to improve disinfection without corroding and damaging the device when the in-situ decontamination of the flow field-based biosafety high efficiency particulate air filter device was carried out.Conclusion The characteristics of the internal flow field of the flow field-based biosafety high efficiency particulate air filter device and the influencing factors of the in-situ disinfection effect are revealed,and theoretical references are provided for the optimal design of the device.[Chinese Medical Equipment Journal,2025,46(9):22-27]