Objective:To investigate the relationship between Ig class switch recombination(CSR)and mismatch repair(MMR)protein,microsatellite phenotype in extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue(MALT lymphoma).Methods:Forty cases of MALT lymphoma archived in the Department of Pathology,Jiading District Central Hospital,Shanghai University of Medicine & Health Sciences were selected as the observation group,and twenty cases of benign lymphoid tissue hyperplasia were as the control group.The expressions of IgG,IgM,IgD,and IgA in both groups were detected by immunohistochemical double staining,and MMR proteins including MLH1,MSH2,MSH6,and PMS2 in both groups were detected by immunohistochemistry.Multiplex fluorescence PCR capillary electrophoresis was used to detect microsatellite phenotype in tumor and adjacent tissues of the experimental group.Results:In the observation group,the proportions of single Ig heavy chain expression(mode Ⅰ),negative expression(mode Ⅱ),and multiple expression(mode Ⅲ)were 65％(26/40),27.5％(11/40),and 7.5％(3/40),respectively,while in the control group were 0(0/20),5％(1/20),and 95％(19/20).The proportion of Ig heavy chain expression mode Ⅰ+Ⅱ in the observation group was 92.5％,which was significantly higher than 5％in the control group(P＜0.0 1).In the observation group,partial deletion of MMR protein was observed in 3 cases(7.5％),including 2 cases of MSH6 deletion and 1 case of both MSH6 and PMS2 deletion.In the control group,there was 1 case(5％)with PMS2 deletion.There was no significant difference in the deletion rate of MMR protein between the two groups(P＞0.05).A total of 5 cases of microsatellite instability(MSI)were detected in the observation group,including 1 case of low-frequency MSI(MSI-L),4 cases of high-frequency MSI(MSI-H),and 2 cases of MSI-H with MSH6 deletion.When the loss expression of MSI-H or MMR protein was counted as a positive result,the MSI-H rate detected by PCR capillary electrophoresis was 10％(4/40),which was slightly higher than the MMR protein deletion rate detected by immunohistochemistry(7.5％,3/40),but there was no statistically significant difference between the two groups(P＞0.05).The MMR protein deletion rates among the Ig heavy chain protein expression mode Ⅰ,mode Ⅱ,and mode Ⅲ groups were 0(0/26),18.2％(2/11),and 33.3％(1/3),respectively.There was a statistically significant difference in the constituent ratios among the three groups(P＜0.05).The MMR protein deletion rates among the MSS,MSI-L,and MSI-H groups were 2.9％(1/35),0(0/1),and 50％(2/4),respectively.There was a statistically significant difference in the constituent ratios among the three groups(P＜0.05).MMR protein deficiency was positively correlated with Ig heavy chain expression pattern and MSI(r=0.41,P＜0.05;r=0.48,P＜0.05),but Ig heavy chain expression pattern was not correlated with MSI(r=0.02,P＞0.05).Conclusion:Ig heavy chain CSR detection is helpful for the differential diagnosis of MALT lymphoma.Low frequency MMR protein deletion and MSI-H phenotype exist in MALT lymphoma,which may be of certain value for the study of its occurrence,development and clinical treatment.

Objective To explore the causal relationship between breast cancer and free fatty acid receptor 4(FFAR4)by using two-sample Mendelian randomization.Methods By using Genome-wide Association Studies and expression quantitative trait locus(eQTL)data,single nucleotide polymorphism sites closely related to breast cancer and FFAR4 were extracted.Causal effect values were calculated by using five methods:inverse variance weighting(IVW),MR-Egger,weighted median,simple mode and weighted mode.Cochran Q tests were used to detect heterogeneity,MR-Egger intercept tests and MR-PRESSO tests were used to assess level multiplicity,and the hold-out method was employed for sensitivity analysis to ensure robustness of the results.Additionally,Bayesian co-location analysis was used to evaluate whether FFAR4 expression shares the same causal genetic variant with breast cancer in given genomic region.Results A total of 12 eQTLs closely related to FFAR4 expression levels were included in this study.The results of IVW analysis showed that increased FFAR4 expression levels increased the risk of overall breast cancer,Luminal A,Luminal B/HER2-negative,and HER2-enhanced subtypes of breast cancer.The co-location analysis showed that the posterior probability of FFAR4 expression level and total breast cancer shared causal variation was 0.889.Conclusion There may be a causal relationship between FFAR4 expression and breast cancer.

Objective To explore the causal relationship between breast cancer and free fatty acid receptor 4(FFAR4)by using two-sample Mendelian randomization.Methods By using Genome-wide Association Studies and expression quantitative trait locus(eQTL)data,single nucleotide polymorphism sites closely related to breast cancer and FFAR4 were extracted.Causal effect values were calculated by using five methods:inverse variance weighting(IVW),MR-Egger,weighted median,simple mode and weighted mode.Cochran Q tests were used to detect heterogeneity,MR-Egger intercept tests and MR-PRESSO tests were used to assess level multiplicity,and the hold-out method was employed for sensitivity analysis to ensure robustness of the results.Additionally,Bayesian co-location analysis was used to evaluate whether FFAR4 expression shares the same causal genetic variant with breast cancer in given genomic region.Results A total of 12 eQTLs closely related to FFAR4 expression levels were included in this study.The results of IVW analysis showed that increased FFAR4 expression levels increased the risk of overall breast cancer,Luminal A,Luminal B/HER2-negative,and HER2-enhanced subtypes of breast cancer.The co-location analysis showed that the posterior probability of FFAR4 expression level and total breast cancer shared causal variation was 0.889.Conclusion There may be a causal relationship between FFAR4 expression and breast cancer.

Objective To explore the value of deep learning image reconstruction(DLIR)by comparing subjective and objec-tive evaluation of DLIR and adaptive statistical iterative reconstruction(ASIR-V)images in gastric cancer CT.Methods Abdominal CT images in the venous phase of 80 untreated patients with primary gastric cancer were included,and five CT reconstruction meth-ods of 50％ASIR-V,80％ASIR-V,DLIR-low(DLIR-L),DLIR-medium(DLIR-M)and DLIR-high(DLIR-H)were adopted,respec-tively.The objective evaluation included background standard deviation(SD),signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR)values and pericancerous fat density resolution.The subjective evaluation included SD,overall image quality,the display of gastric cancer lesions,and diagnostic confidence in whether the serosal surface of the gastric wall was infiltrated.Results The subjective and objective evalua-tion indicators showed statistically significant differences among the five reconstruction models(P＜0.001).In terms of objective evalua-tion,the SD value of gastric cancer lesions in the DLIR-H was the lowest,while the SNR and CNR values were the highest among the five groups.In terms of subjective evaluation,the DLIR-M had the highest scores in gastric cancer lesions display,overall image quality and diagnostic confidence among the five groups.Conclusion Compared with ASIR-V,DLIR can significantly reduce image noise and improve image quality,and DLIR-M and DLIR-H are respectively the optimal subjective and objective reconstruction models for showing gastric cancer lesions.

Objective To understand the current situation of healthcare-associated infection(HAI)in China,pro-vide data support and decision-making basis for formulating scientific and effective strategies for HAI prevention and control.Methods A nationwide cross-sectional survey on HAI was conducted among various types and levels of medical institutions in China according to a unified protocol of bedside surveys and case investigations.Results In 2024,a total of 5 736 medical institutions and 2 751 765 patients were surveyed.Among them,34 889 HAI cases were identified,with a prevalence rate of 1.27％.The number of HAI episodes was 38 032,and case prevalence rate was 1.38％.The prevalence rate of HAI in medical institutions in different regions of China ranged from 0.66％to 2.35％.Among medical institutions of different scales,those with a bed capacity of ≥900 had the high-est incidence of HAI,reaching 1.65％.The most common infection site was the lower respiratory tract(44.66％),followed by the urinary tract(12.94％),surgical site(9.32％),upper respiratory tract(7.02％),and bloodstream infection(5.78％).The top 3 departments with the highest HAI rates were the general intensive care unit(10.02％),department of neurosurgery(5.51％),and department(group)of hematology(5.34％).A total of 23 238 strains of HAI pathogens were detected,with 10 714 strains(46.10％)from lower respiratory tract speci-mens.The top 5 detected strains were Klebsiella pneumoniae(14.76％),Pseudomonas aeruginosa(13.33％),Escherichia coli(12.79％),Acinetobacter baumannii(9.23％),and Staphylococcus aureus(7.88％).231 944 pa-tients underwent class Ⅰ incision surgery were monitored,with 1 647 cases experienced surgical site infection,and the prevalence rate of surgical site infection was 0.71％.The number of patients who should undergo pathogen de-tection(patients receiving therapeutic and therapeutic combined prophylactic antimicrobial agents)was 715 179,while the actual number was 480 492,with a pathogen detection rate of 67.18％.425 225 patients received patho-genic detection before treatment,with a detection rate of 59.46％.Conclusion The overall HAI prevalence in Chi-na is lower,showing disparities among medical institutions of different regions and scales.Therefore,precise imple-mentation of measures is necessary for HAI prevention and control,with a focus on high-risk institutions and high-risk departments,key areas,and critical procedures.All levels of medical institutions should continuously reduce the incidence of HAI by strengthening monitoring,standardizing the use of antimicrobial agents,and reinforcing basic HAI prevention and control measures.

Objective:To investigate the incidence,clinical characteristics,and complications of Torque teno virus(TTV)in children after hematopoietic stem cell transplantation(HSCT).Methods:A total of 40 children with hematological diseases who underwent HSCT were selected,and metagenomic next-generation sequencing(mNGS)technology was used to detect the gene sequences of pathogenic microorganisms in the blood.Combined with clinical data,the characteristics of TTV infection were analyzed.Results:Among the 40 pediatric patients post-HSCT,the TTV positive rate was 42.5％(17/40).There were no statistically significant differences between the TTV-positive group and the TTV-negative group in sex,age,white blood cell count(WBC),red blood cell count(RBC),hemoglobin,platelet count,neutrophil count,lymphocyte count,and high-sensitivity C-reactive protein(all P＞0.05).The incidence of TTV infection was significantly higher in children who underwent haploidentical HSCT and in those with bone marrow stem cells(BMSC)as the transplant source(P＜0.05).However,there were no significant differences in the TTV infection rate among patients with different disease types,different HLA matching statuses,or different engraftment times of neutrophils and platelets(all P＞0.05).Among 17 children infected with TTV,13(76.5％)had co-infections with other viruses,mainly including cytomegalovirus(58.8％,10/17),human polyomavirus(41.2％,7/17),and Epstein-Barr virus(17.6％,3/17).In children with TTV infection,the most common complications were sepsis(82.4％),graft-versus-host disease(GVHD)(70.6％),pulmonary infection(41.2％),and hemorrhagic cystitis(17.6％).The incidence of GVHD in the TTV-positive group was significantly higher than that in the TTV-negative group(P＜0.05).Conclusion:TTV infection is common in children undergoing HSCT,and it is prone to be complicated with cytomegalovirus infection and GVHD,which has an important influence on the clinical outcomes.

Objective:To explore the efficacy and adverse reactions of CAG regimen combined with venetoclax,chidamide,and azacitidine in the treatment of elderly patients with acute myeloid leukemia(AML).Methods:15 elderly AML patients aged ≥ 60 years old who were admitted to the Hematology Department of our hospital from May 2022 to October 2023 were treated with the CAG regimen combined with venetoclax,chidamide and azacitidine,and the efficacy,treatment-related adverse events,overall survival(OS)and event-free survival(EFS)were analyzed.Results:After one course of treatment,11 out of 15 patients achieved complete response(CR),3 patients achieved CR with incomplete hematologic recovery(CRi),and 1 patient died due to prior infection before efficacy evaluation,and the overall response rate(ORR)was 93.3％(14/15).The median follow-up time was 131(19-275)days,with median OS and EFS both remaining unreached.Next-generation sequencing(NGS)analysis showed that among the 15 patients,13 were detected with gene mutations,and there were 7 genes with mutation frequencies of more than 10％,including ASXL1(4 cases),RUNX1(4 cases),BCOR(3 cases),DNMT3A(3 cases),STAG2(2 cases),IDH1/2(2 cases),and TET(2 cases).Among the 13 patients with detectable mutations,12 patients achieved composite response(CR+CRi).The average recovery time of white blood cell count was 14.6 days after chemotherapy,and the average recovery time of platelets was 7.7 days after chemotherapy.The main adverse event was myelosuppression,with 10 patients accompanied by infection.Except for 1 patient who died due to septic shock during chemotherapy,no patients experienced serious complications such as heart,liver,or kidney damage during the treatment process.Conclusion:The CACAG+V regimen,which combines the CAG regimen with venetoclax,chidamide,and azacitidine,can be applied in the treatment of elderly AML patients,demonstrating good safety and induction remission rate.

Objective To understand the current situation of healthcare-associated infection(HAI)in China,pro-vide data support and decision-making basis for formulating scientific and effective strategies for HAI prevention and control.Methods A nationwide cross-sectional survey on HAI was conducted among various types and levels of medical institutions in China according to a unified protocol of bedside surveys and case investigations.Results In 2024,a total of 5 736 medical institutions and 2 751 765 patients were surveyed.Among them,34 889 HAI cases were identified,with a prevalence rate of 1.27％.The number of HAI episodes was 38 032,and case prevalence rate was 1.38％.The prevalence rate of HAI in medical institutions in different regions of China ranged from 0.66％to 2.35％.Among medical institutions of different scales,those with a bed capacity of ≥900 had the high-est incidence of HAI,reaching 1.65％.The most common infection site was the lower respiratory tract(44.66％),followed by the urinary tract(12.94％),surgical site(9.32％),upper respiratory tract(7.02％),and bloodstream infection(5.78％).The top 3 departments with the highest HAI rates were the general intensive care unit(10.02％),department of neurosurgery(5.51％),and department(group)of hematology(5.34％).A total of 23 238 strains of HAI pathogens were detected,with 10 714 strains(46.10％)from lower respiratory tract speci-mens.The top 5 detected strains were Klebsiella pneumoniae(14.76％),Pseudomonas aeruginosa(13.33％),Escherichia coli(12.79％),Acinetobacter baumannii(9.23％),and Staphylococcus aureus(7.88％).231 944 pa-tients underwent class Ⅰ incision surgery were monitored,with 1 647 cases experienced surgical site infection,and the prevalence rate of surgical site infection was 0.71％.The number of patients who should undergo pathogen de-tection(patients receiving therapeutic and therapeutic combined prophylactic antimicrobial agents)was 715 179,while the actual number was 480 492,with a pathogen detection rate of 67.18％.425 225 patients received patho-genic detection before treatment,with a detection rate of 59.46％.Conclusion The overall HAI prevalence in Chi-na is lower,showing disparities among medical institutions of different regions and scales.Therefore,precise imple-mentation of measures is necessary for HAI prevention and control,with a focus on high-risk institutions and high-risk departments,key areas,and critical procedures.All levels of medical institutions should continuously reduce the incidence of HAI by strengthening monitoring,standardizing the use of antimicrobial agents,and reinforcing basic HAI prevention and control measures.

Objective:To investigate the incidence,clinical characteristics,and complications of Torque teno virus(TTV)in children after hematopoietic stem cell transplantation(HSCT).Methods:A total of 40 children with hematological diseases who underwent HSCT were selected,and metagenomic next-generation sequencing(mNGS)technology was used to detect the gene sequences of pathogenic microorganisms in the blood.Combined with clinical data,the characteristics of TTV infection were analyzed.Results:Among the 40 pediatric patients post-HSCT,the TTV positive rate was 42.5％(17/40).There were no statistically significant differences between the TTV-positive group and the TTV-negative group in sex,age,white blood cell count(WBC),red blood cell count(RBC),hemoglobin,platelet count,neutrophil count,lymphocyte count,and high-sensitivity C-reactive protein(all P＞0.05).The incidence of TTV infection was significantly higher in children who underwent haploidentical HSCT and in those with bone marrow stem cells(BMSC)as the transplant source(P＜0.05).However,there were no significant differences in the TTV infection rate among patients with different disease types,different HLA matching statuses,or different engraftment times of neutrophils and platelets(all P＞0.05).Among 17 children infected with TTV,13(76.5％)had co-infections with other viruses,mainly including cytomegalovirus(58.8％,10/17),human polyomavirus(41.2％,7/17),and Epstein-Barr virus(17.6％,3/17).In children with TTV infection,the most common complications were sepsis(82.4％),graft-versus-host disease(GVHD)(70.6％),pulmonary infection(41.2％),and hemorrhagic cystitis(17.6％).The incidence of GVHD in the TTV-positive group was significantly higher than that in the TTV-negative group(P＜0.05).Conclusion:TTV infection is common in children undergoing HSCT,and it is prone to be complicated with cytomegalovirus infection and GVHD,which has an important influence on the clinical outcomes.

Intervention in chronically activated microglia-mediated neuroinflammation is a novel approach to treat Alzheimer's disease (AD). The low permeability of the blood‒brain barrier (BBB) and non-selective distribution in the brain severely restrict AD drugs' disease-modifying efficacy. Here, an immunosuppressant TREM2-lowing antisense oligonucleotides (ASOs) and resveratrol co-loaded cationic liposome is developed as an immune reprogramming nanomodulator modified by acid-cleavable BBB-targeting peptide and microglia-targeting peptide (Res@TcMNP/ASO) for AD management. Res@TcMNP/ASO can enter brain endothelial cells via D-T7 peptides. Then D-T7 undergoes an acid-responsive cleavage, facilitating the escape of Res@MNP/ASO from endo/lysosomes to cross the BBB. The detached Res@MNP/ASO specifically targets M1-phenotype microglia via exposed MG1 peptides to prompt the simultaneous delivery of two drugs into activated microglia. This nanomodulator can not only restore the immune function of microglia through TREM2-lowing ASO but also mitigate the immune stimulation to microglia caused by reactive oxygen species (ROS) through resveratrol, thereby synergistically inhibiting the chronic activation of microglia to alleviate neuroinflammation in AD. Our results indicate that this combination treatment can achieve significant behavioral and cognitive improvements in late APP/PS1 mice.