ObjectiveJunctophilin-2 (JPH2) is an essential structural protein that maintains junctional membrane complexes (JMCs) in cardiomyocytes by tethering the plasma membrane to the sarcoplasmic reticulum, thereby facilitating excitation-contraction (E-C) coupling. Mutations in JPH2 have been associated with hypertrophic cardiomyopathy (HCM), but the molecular mechanisms governing its membrane-binding properties and the functional relevance of its membrane occupation and recognition nexus (MORN) repeat motifs remain incompletely understood. This study aimed to elucidate the structural basis of JPH2 membrane association and its implications for HCM pathogenesis. MethodsA recombinant N-terminal fragment of mouse JPH2 (residues1-440), encompassing the MORN repeats and an adjacent helical region, was purified under near-physiological buffer conditions.X-ray crystallography was employed to determine the structure of the JPH2 MORN-Helix domain. Sequence conservation analysis across species and junctophilin isoforms was performed to assess the evolutionary conservation of key structural features. Functional membrane-binding assays were conducted using liposome co-sedimentation and cell-based localization studies in COS7 and HeLa cells. In addition, site-directed mutagenesis targeting positively charged residues and known HCM-associated mutations, including R347C, was used to evaluate their effects on membrane interaction and subcellular localization. ResultsThe crystal structure of the mouse JPH2 MORN-Helix domain was resolved at 2.6 Å, revealing a compact, elongated architecture consisting of multiple tandem MORN motifs arranged in a curved configuration, forming a continuous hydrophobic core stabilized by alternating aromatic residues. A C-terminal α-helix further reinforced structural integrity. Conservation analysis identified the inner groove of the MORN array as a highly conserved surface, suggesting its role as a protein-binding interface. A flexible linker segment enriched in positively charged residues, located adjacent to the MORN motifs, was found to mediate direct electrostatic interactions with negatively charged phospholipid membranes. Functional assays demonstrated that mutation of these basic residues impaired membrane association, while the HCM-linked R347C mutation completely abolished membrane localization in cellular assays, despite preserving the overall MORN-Helix fold in structural modeling. ConclusionThis study provides structural insight into the membrane-binding mechanism of the cardiomyocyte-specific protein JPH2, highlighting the dual roles of its MORN-Helix domain in membrane anchoring and protein interactions. The findings clarify the structural basis for membrane targeting via a positively charged linker and demonstrate that disruption of this interaction—such as that caused by the R347C mutation—likely contributes to HCM pathogenesis. These results not only enhance current understanding of JPH2 function in cardiac E-C coupling but also offer a structural framework for future investigations into the assembly and regulation of JMCs in both physiological and disease contexts.

ObjectiveTo establish background data for a 90-day feeding trial of SD rats to ensure the reliability of research data. MethodsBackground data from six independent 90-day feeding trials of SD rats conducted by the National Center for Safety Evaluation of Drugs from 2020 to 2023 were summarized. These studies involved a blank control group of 120 SPF-grade 4-week-old SD rats, with an equal number of males and females, which were only given standard full-nutrient pelleted rat feed. After the quarantine period, the animals were observed for an additional 90 days, followed by intraperitoneal injection of Zoletil (50 mg/mL) for anesthesia, blood sampling, euthanasia, and necropsy. By analyzing the data from the blank control group, a relevant background database for SD rats was established. ResultsBoth male and female rats exhibited steady weight gain, with a more pronounced increase in male rats. Within 90 days, the average body weight of male and female rats increased to over 500 g and 300 g, respectively. Three weeks later, the average daily food intake of male rats stabilized at approximately 25~28 g per rat, while that of female rats remained stable at approximately 16~19 g per rat. The food utilization rate of all animals gradually decreased from the first week of the experiment. In the white blood cell (WBC) differential count results, significant differences were observed in the counts of WBCs, neutrophils (Neut), lymphocytes (Lymph), and monocytes (Mono) between males and females (P<0.001). However, there were no significant differences in the percentages of neutrophil (%Neut), lymphocyte (%Lymph), and monocyte (%Mono) between the sexes (P>0.05). The average red blood cell count (RBC), hemoglobin concentration (HGB), hematocrit (HCT), platelet count (PLT), prothrombin time (PT), and activated partial thromboplastin time (APTT) were higher in male animals than in female animals (P<0.05). The average values of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), creatine phosphokinase (CK), lactate dehydrogenase (LDH), glucose (GLU), and triglyceride (TG) in male rats were higher than those in female rats (P<0.05). The urinary pH range for male animals was 5.0 to 8.5, while for female animals it was 6.5 to 9.0. The majority of male animals had a urinary specific gravity lower than 1.020, and the majority of female animals had a urinary specific gravity lower than 1.015. The weights of various organs (excluding the adrenal glands and reproductive organs) in male animals were heavier than those in female animals (P<0.001), while the organ/body weight ratios (excluding the kidneys and reproductive organs) of female animals were higher than those of male animals (P<0.001). ConclusionThis study summarizes the background reference ranges for body weight, food intake, hematology, and serum biochemistry indicators in SPF-grade SD rats in the untreated control group from six 90-day feeding trials conducted by the National Center for Safety Evaluation of Drugs. It provides important reference data for related research. By summarizing the background and spontaneous histopathological changes in rats, this study aids in the standardization and normalization of subsequent research, as well as in the evaluation and analysis of abnormal results.

Amantadine(AMD)residue can accumulate in organisms through the food chain and cause serious harm to human body.AMD can specifically bind to AMD specific aptamer and cause its conformation to change from a random single strand to a stem-loop structure.To avoid the influence of excess nucleotides on binding of aptamer to AMD,the truncation of the AMD original aptamer J was optimized by retaining an appropriate stem-loop structure,and a new type of truncation aptamers was developed in this work.By comparing the truncated aptamer with the original aptamer,it was found that the truncated aptamer J-7 had better affinity and specificity with AMD.The detection limit of AMD was 0.11 ng/mL by using J-7 as specific recognition element and molybdenum disulfide nanosheet(MoS2Ns)as signal amplification element.The developed method base on truncated aptamer J-7 was used for detection of AMD in milk,yogurt and SD rat serum samples for the first time with recoveries of 86.6%-108.2%.This study provided a reference for truncating other long sequence aptamers and provided a more sensitive detection method for monitoring AMD residues in food.

Objective To investigate the toxicokinetic differences of 3,4-methylenedioxy-N-methylamphetamine(MDMA)and its metabolite 4,5-methylene dioxy amphetamine(MDA)in rats af-ter single and continuous administration of MDMA,providing reference data for the forensic identifica-tion of MDMA.Methods A total of 24 rats in the single administration group were randomly divided into 5,10 and 20 mg/kg experimental groups and the control group,with 6 rats in each group.The ex-perimental group was given intraperitoneal injection of MDMA,and the control group was given intraperi-toneal injection of the same volume of normal saline as the experimental group.The amount of 0.5 mL blood was collected from the medial canthus 5 min,30 min,1 h,1.5 h,2 h,4 h,6 h,8 h,10 h,12 h after administration.In the continuous administration group,24 rats were randomly divided into the experi-mental group(18 rats)and the control group(6 rats).The experimental group was given MDMA 7 d by continuous intraperitoneal injection in increments of 5,7,9,11,13,15,17 mg/kg per day,respectively,while the control group was given the same volume of normal saline as the experimental group by in-traperitoneal injection.On the eighth day,the experimental rats were randomly divided into 5,10 and 20 mg/kg dose groups,with 6 rats in each group.MDMA was injected intraperitoneally,and the con-trol group was injected intraperitoneally with the same volume of normal saline as the experimental group.On the eighth day,0.5 mL of blood was taken from the medial canthus 5 min,30 min,1 h,1.5 h,2 h,4 h,6 h,8 h,10 h,12 h after administration.Liquid chromatography-triple quadrupole tandem mass spectrometry was used to detect MDMA and MDA levels,and statistical software was employed for data analysis.Results In the single-administration group,peak concentrations of MDMA and MDA were reached at 5 min and 1 h after administration,respectively,with the largest detection time limit of 12 h.In the continuous administration group,peak concentrations were reached at 30 min and 1.5 h af-ter administration,respectively,with the largest detection time limit of 10 h.Nonlinear fitting equations for the concentration ratio of MDMA and MDA in plasma and administration time in the single-administration group and continuous administration group were as follows:T=10.362C-1.183,R2=0.974 6;T=7.397 3C-0.694,R2=0.961 5(T:injection time;C:concentration ratio of MDMA to MDA in plasma).Conclusions The toxicokinetic data of MDMA and its metabolite MDA in rats,obtained through single and continuous administration,including peak concentration,peak time,detection time limit,and the relationship between concentration ratio and administration time,provide a theoretical and data foundation for relevant forensic identification.

Objective To explore the application of metagenomic next-generation sequencing(mNGS)technology in the investigation of healthcare-associated infection(HAI)outbreaks of carbapenem-resistant Acinetobacter bau-mannii(CRAB).Methods Pathogenic detection by mNGS and conventional pathogen culture were performed on 5 patients in the intensive care unit(ICU)of a hospital from June 8 to 22,2023 from whom CRAB were detected.Microbial sampling was carried out in potentially contaminated environment.Bacterial culture,identification,and antimicrobial susceptibility testing were conducted.Comprehensive control measures were taken,and the effect was evaluated.Results The time required for reporting results by mNGS was shorter than the culture time([3.92± 1.05]days vs[6.24±0.25]days,P＜0.001).CRAB was isolated from the specimens of 5 patients.mNGS de-tected OXA-23 resistance genes from all patients.After comprehensive assessment by experts,4 patients were HAI and 1 patient was due to specimen contamination.According to the definition from Guidelines for HAI outbreak control,this event was considered an outbreak of HAI.The monitoring results of environmental hygiene showed that the detection rate of CRAB in the environment during the outbreak was 51.30％(59/115),mainly from the hands of health care workers and the surface of ventilators.After implementing multidisciplinary infection control measures,clinicians'hand hygiene compliance rate and implementation rate of ventilator disinfection increased from 40.83％(49/120)and 33.33％(16/48)to 82.61％(95/115)and 83.33％(30/36),respectively.The prognosis of patients was good,and no new case emerged during subsequent monitoring.The outbreak of HAI in this hospital has been effectively controlled.Conclusion mNGS is characterized by high precision,less time consumption,and high accuracy,and can be applied to the prevention and control of HAI outbreak and the study of antimicrobial-re-sistant genomes.It is of great significance for the anti-infection treatment of patients with multidrug-resistant orga-nism infection as well as the formulation of HAI prevention and control measures.Continuous improving disinfec-tion effectiveness and hand hygiene compliance is important for preventing and controlling CRAB infection.

Objective China is among the 30 countries with a high burden of tuberculosis(TB)worldwide,and TB remains a public health concern.Kashgar Prefecture in the southern Xinjiang Autonomous Region is considered as one of the highest TB burden regions in China.However,molecular epidemiological studies of Kashgar are lacking. Methods A population-based retrospective study was conducted using whole-genome sequencing(WGS)to determine the characteristics of drug resistance and the transmission patterns. Results A total of 1,668 isolates collected in 2020 were classified into lineages 2(46.0%),3(27.5%),and 4(26.5%).The drug resistance rates revealed by WGS showed that the top three drugs in terms of the resistance rate were isoniazid(7.4%,124/1,668),streptomycin(6.0%,100/1,668),and rifampicin(3.3%,55/1,668).The rate of rifampicin resistance was 1.8%(23/1,290)in the new cases and 9.4%(32/340)in the previously treated cases.Known resistance mutations were detected more frequently in lineage 2 strains than in lineage 3 or 4 strains,respectively:18.6%vs.8.7 or 9%,P<0.001.The estimated proportion of recent transmissions was 25.9%(432/1,668).Multivariate logistic analyses indicated that sex,age,occupation,lineage,and drug resistance were the risk factors for recent transmission.Despite the low rate of drug resistance,drug-resistant strains had a higher risk of recent transmission than the susceptible strains(adjusted odds ratio,1.414;95%CI,1.023-1.954;P = 0.036).Among all patients with drug-resistant tuberculosis(DR-TB),78.4%(171/218)were attributed to the transmission of DR-TB strains. Conclusion Our results suggest that drug-resistant strains are more transmissible than susceptible strains and that transmission is the major driving force of the current DR-TB epidemic in Kashgar.

Eleven compounds were isolated from Eucommia ulmoides by silica gel, Sephadex LH-20, HW-40C column chromatography and semi-preparative HPLC. Their structures were identified by modern spectroscopic methods as neoeucommiate A (1), (7S,8R)-dihydrodehydrodiconiferyl alcohol (2), urolignoside (3), ficusal (4), tiruneesiin (5), glochidioboside (6), forsythialansides B (7), ecdysanol B (8), (+)-syringaresinol-4-O-β-D-glucopyranoside (9), (+)-pinoresinol 4-O-[6ʹʹ-O-vanilloyl]-β-D-glucopyranoside (10), samsesquinoside (11). Compound 1 is a new compound, compounds 3-7, 10 and 11 were isolated from Eucommia ulmoides for the first time.

Objective To evaluate and compare the success rate and short-term clinical prognosis of transfemoral transcatheter aortic valve replacement(TF-TAVR)for patients with pure aortic regurgitation(PAR)of different annulus sizes.Methods This study is a single center retrospective study,selecting symptomatic PAR patients who received TF-TAVR treatment at Zhongshan Hospital Fudan University from September 2019 to September 2023.Based on preoperative CT results,all patients were divided into three groups:Group A(aortic annulus circumference＜80 mm),Group B(80 mm≤aortic annulus circumference＜85 mm),and Group C(aortic annulus circumference≥ 85 mm).The primary endpoint was success rate and 30d all-cause mortality,while the secondary endpoint was TAVR related complications.Results A total of 61 PAR patients were included in this study,including 27 in Group A,21 in Group B,and 13 in Group C.The overall success rate is 82.0％,and the 30 d all-cause mortality rate is 3.3％.The success rate of Group C patients was significantly lower(P=0.012),with higher rates of conversion to surgery and valve-in-valve implantation(P=0.022 and P=0.040).In terms of secondary endpoint events,there were no significant differences among the three groups in major bleeding events,major vascular complications,stroke,myocardial infarction,newly developed atrial fibrillation,implantation of new pacemakers,coronary artery occlusion,and postoperative moderate to severe perivalvular leakage(all P＞0.05).Conclusions The circumference of the aortic valve annulus is a key factor affecting the success rate of TF-TAVR in PAR,and PAR patients with an aortic valve annulus circumference less than 85mm may be more suitable for TF-TAVR.

Objective To analyze the clinical and serological typing characteristics of invasive Haemophilus influ-enzae(Hin)infection in children.Methods Clinical data of 34 children with invasive Hin infection admitted to Children's Hospital of Shanxi from 2015 to 2021 were analyzed retrospectively.According to clinical diagnosis,they were divided into meningitis infection group and non-meningitis infection group.General data,symptoms,signs,laboratory serological indicators,and Hin serum typing characteristics of children,as well as differences in inflammatory factor level between the two groups were analyzed.Results Among the 34 patients,22 were males and 12 were females,with a male to female ratio of 1.83∶1.Children aged ≤36 months accounted for 82.35％.The levels of procalcitonin(PCT)(23.71[4.10,77.80])ng/mL and C-reactive protein(CRP)(200.00[164.55,200.00])mg/L in children in the meningitis infection group were higher than those in the non-meningitis group(1.08[0.49,6.00]ng/mL,69.46[48.09,125.63]mg/L,respectively),with statistically significant differences(both P＜0.05).The platelet(PLT)count in the non-meningitis group([312.56±186.81]× 109/L)was higher than that in the meningitis group([183.28±165.67]× 109/L),with statistically significant difference(P＜0.05).There was no statistically significant difference in white blood cell(WBC)count and neutrophil(NEUT)percentage between two groups(both P＞0.05).Among the isolated Hin strains,27,2,and 2 strains were type b(Hib),e and f,respectively;3 strains were not typed;serotype a,c and d strains were not found.There was no statistically significant difference in the distribution of typeable Hin strains between the two groups(x2=0.25,P＞0.05).There was no statistically significant difference in the constituent rate of typeable Hin strains between male and fe-male children(67.74％vs 32.26％,x2=1.42,P＞0.05).Conclusion The majority of invasive Hin infection cases are children under 3 years old,and the predominant strain is type b.CRP and PCT levels of infected children in-creased significantly,while PLT is significantly lower than that of non-infected children,which has certain clinical diagnostic value and can provide effective support for early classified diagnosis and anti-infection treatment of inva-sive infectious diseases combined with other clinical testing items.

Objective To analyze the effects of different anastomotic methods on flap survival rate and wound healing factors of patients with transplantation of superficial branch perforator flap of superficial circumflex iliac artery(SCIA).Methods A total of 100 patients with skin defects of limbs admitted to our hospital from January 2019 to August 2022 were selected and divided into end-to-end anastomosis group(56 cases)and end-to-side anastomosis group(44 cases)according to different anastomosis methods.In the end-to-end anastomosis group,the end of the flap artery was anastomosed with the end of the aortic branch in the affected area.In the end-to-side anastomosis group,the end of recipient flap artery was anastomosed with the side of aorta.Patients in both groups were followed up for 6 to 12 months,the arterial caliber,lateral caliber and anastomosis time were compared between the two groups.The survival of the flap,the occurrence of venous crisis,the shape and function of the flap and donor area were observed.Results There was no statistically significant difference in the arterial caliber or lateral caliber of patients between the two groups(P>0.05).The anastomosis time of patients in the end-to-end anastomosis group was significantly shorter than that in the end-to-side anastomosis group(P<0.05).All 56 cases in the end-to-end anastomosis group survived.In the end-to-side anastomosis group,venous crisis occurred in 4 cases,with venous thrombosis,2 cases survived after re-anastomosis,2 cases were changed to abdominal pedicled flap when venous crisis occurred again,the appearance and function of the flap and donor area were satisfactory 6 months to 1 year after surgery(P<0.05).There was no significant difference in color,thickness,vascular distribution or flexibility of donor area of patients between the two groups(P>0.05).There was no significant difference in pain,appearance,vitality and recreation of recipient area of patients between the two groups(P>0.05).Conclusion The application of different arterial anastomosis methods in the transplantation of superficial branch perforator flap of SCIA for the treatment of skin and soft tissue defects of limbs is safe and reliable,the postoperative survival of the flap is good,the healing is not affected by the anastomosis method,and the appearance of the affected area is satisfactory,which is worthy of clinical promotion.