Objective To evaluate the safety and efficacy of a self-developed micro-normothermic machine perfusion (NMP) system (micro-perfusion device) for preserving isolated porcine limbs. Methods Five healthy Landrace pigs were selected, and their left and right forelimbs were randomly divided into the NMP group and static cold storage (SCS) group. The NMP group was perfused with the self-developed micro-perfusion device and polymerized hemoglobin perfusate for 32 hours at normothermia, while the SCS group was preserved at 4 ℃. Hemodynamic parameters such as perfusion pressure and flow were monitored. The pH value, partial pressure of oxygen (PO₂), lactic acid (Lac), creatine kinase (CK) and lactate dehydrogenase (LDH) in the perfusate were measured. Hematoxylin-eosin staining was used to assess the muscle tissue structure, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling was employed to evaluate muscle cell apoptosis, and immunohistochemistry staining was applied to detect the expressions of tumor necrosis factor (TNF)-α and interleukin (IL)-6. A mixed-effects model was used to analyze the effects of time and treatment methods on tissue structure, cell apoptosis and inflammatory factors. Results The device could stably maintain a perfusion pressure of (69±15) mmHg and a flow rate of (117±42) mL/min. The pH value and electrolytes of the perfusate were generally stable, with PO₂ maintained at a high level. Lac was maintained at 5.38(3.81, 6.45) mmol/L, while CK and LDH increased over time. After 32 hours of perfusion in the NMP group, both the myocyte spacing and apoptosis rate were better than those in the SCS group. Mixed-effects model analysis showed that there were statistically significant differences in the effects of NMP treatment and SCS treatment on myocyte spacing and apoptosis rate per unit time (both P < 0.05). There were no statistically significant differences in TNF-α and IL-6 between the two groups, and mixed-effects model analysis showed no statistically significant differences in the effects of NMP treatment and SCS treatment on TNF-α and IL-6 per unit time (both P > 0.05). Conclusions The micro-perfusion device used in this study may achieve 32-hour normothermic preservation in a porcine limb amputation model, maintain basic metabolism and ionic homeostasis, reduce muscle structural damage and cell apoptosis without inducing additional inflammatory responses. This technology is expected to significantly extend the time window for replantation of amputated limbs in disaster rescue and long-distance transportation, providing an important technical basis for clinical translation and subsequent replantation research.

An assay was established for detection of toxigenic Clostridioides difficile by combining microfluidic chip analysis with immunochromatography,and its performance was evaluated and compared with those of the Xpert C.difficile/Epi and VIDAS CD AB tests.Primer pairs were designed according to the tcdB and tpi genes in C.difficile.The specificity,limit of detection,reproducibility,and stability were evaluated.A total of 215 stool samples from patients with diarrhea were collected and tested in parallel with the Xpert C.difficile/Epi,VIDAS CDAB,and our assay.C.difficile was isolated from samples,and the tcdB gene was identified when discrepant results were obtained from the three above assays.Our assay showed no cross-reaction with other diarrhea-associated pathogens.Its reproducibility was 100％in testing of two standard plasmids containing tcdB and tpi genes at two concentrations(105 and 102 copies/μL).Two standard plasmids were detected after the PCR and immunochromatography reagents had been stored for 3,6,9,and 12 months,and all the results were posi-tive.The limit of detection was 10 copies/μL for toxigenic C.difficile.Testing of 33 samples positive for C.difficile with our assay(33/215,15.3％)yielded findings statistically coherent with those of the Xpert C.difficile/Epi test(kappa value=0.965).The sensitivity,specificity,positive predictive value,and negative predictive value of our assay,with respect to Xpert C.difficile/Epi as the standard,were 94.3％,100.0％,100.0％,and 98.9％;these values were significantly higher than those of VIDAS CDAB(60.0％,98.9％,91.3％,and 92.7％)(Kappa=0.714,OR=157.50,95％CI:62.03-847.28,P=0.013).In conclusion,our newly developed assay is specific,stable,and reproducible,and may be used for rapid and accu-rate detection of toxigenic C.difficile.The assay could be used for C.difficile infection screening in outpatient and emergen-cy,community medical service center,and epidemiological settings.

To perform the phylogenetic characterization of an isolated porcine rotavirus(PoRV)and investigate its pathogenicity in suckling mice and piglets.A G4P[23]genotype PoRV strain JSJR2023 was successfully isolated from the diarrheic piglet feces through propagation in MA104 cells.The viral proliferation kinetics were analyzed using TCID50 assays,followed by complete genome sequencing through Sanger sequencing platforms.Comprehensive genotyping and phylogenetic reconstruction were conducted using MEGA7.0 with maximum likelihood algorithms.Pathogenicity was assessed in the following animal models:5-day-old C57BL/6 mice and 3-day-old piglets.Multidimensional evaluation included clinical monitoring(diarrhea scoring,growth parameters),virological detection,and histopathological analysis of intestinal tissues.The virus strain JSJR2023 could replicate efficiently in MA104 cells,achieving peak titers of 107.5 TCID50/mL.Whole genome genotype analysis showed that the strain belonged to G4-P[23]-I5-R1-C1-M1-A8-N1-T1-E1-H1.Phylogenetic analysis indicated that the VP3 and NSP4 genes of JSJR2023 strain were most closedrelated to human species rotaviruses,suggesting genetic reassortment between human and porcine RV strains.The animal experiments in suckling mice showed that the JSJR2023 strain infection caused diarrhea symptoms,intestinal edema and congestion,and shedding of intestinal villus epithelial cells.The pathogenicity experiments in piglets showed that compared with the control group,the challenged group of pig-lets had severe diarrhea symptoms,accompanied by reduced appetite and listlessness.Post-mortem examination revealed that the intes-tines were significantly thinner,congested,and filled with yellow watery contents.The challenged piglets showed typical pathological changes such as thinning of the intestinal wall and shortening and shedding of intestinal villi.In conclusion,this study successfully iso-lated a human-porcine recombinant G4P[23]PoRV strain and established the infection models in suckling mice and piglets,providing important tools for investigating the pathogenic mechanism of PoRV,evaluating vaccines and developing antiviral drug.

Objective·To investigate the effects of liraglutide on liver fibrosis in mice with non-alcoholic fatty liver disease(NAFLD)and the underlying mechanisms.Methods·Twenty 8-week-old C57BL/6J mice were randomly divided into a normal chow diet group(Chow group)and a methionine-choline-deficient(MCD)diet group(MCD group),with 10 mice per group.The MCD diet was used to induce NAFLD.Each group was further divided into two subgroups,resulting in four subgroups:Chow+saline,Chow+liraglutide,MCD+saline,and MCD+liraglutide group.After daily intraperitoneal injection of liraglutide(400 μg/kg)or an equivalent volume of saline for 4 weeks,an intraperitoneal glucose tolerance test(IPGTT)was performed.Serum levels of aspartate transaminase(AST),alanine aminotransferase(ALT),total cholesterol(TC),triglyceride(TAG),high-density lipoprotein cholesterol(HDL-C),and low-density lipoprotein cholesterol(LDL-C)were measured.Liver tissues were collected post-euthanasia to assess TAG content.Histopathological changes,lipid deposition,and fibrosis were evaluated via hematoxylin-eosin(HE)staining,Oil Red O staining,and Masson staining.Real-time quantitative PCR(qPCR)and Western blotting were used to analyze the expression of α-smooth muscle actin(α-SMA),fibronectin(FN),collagen type Ⅰ α(COL1A),matrix metalloproteinase 9(MMP9),tissue inhibitor of metalloproteinase 1(TIMP1),transforming growth factor β(TGF-β),SMAD3,and phosphorylated SMAD3(pSMAD3).Results·The IPGTT revealed that liraglutide intervention reduced blood glucose levels at 15,30,and 60 min,with a decreased area under the curve(AUC)(both P<0.05).Biochemical analysis showed that liraglutide lowered AST and ALT levels(both P<0.001),increased TC and HDL-C levels(both P<0.05),but had no significant effect on TAG or LDL-C in MCD mice.HE staining and Oil Red O staining revealed reduced lipid droplets,ballooning degeneration,and inflammatory infiltration in hepatocytes after liraglutide treatment.Masson staining indicated decreased collagen fiber deposition in the liver.qPCR and Western blotting analysis demonstrated upregulated expression of α-SMA,FN,COL1A,TIMP1,TGF-β,and pSMAD3/SMAD3,alongside downregulated MMP9 in MCD mice.Liraglutide reversed these changes,lowering α-SMA,FN,COL1A,TIMP1,TGF-β,and pSMAD3/SMAD3 expression while increasing MMP9 expression.Conclusion·Liraglutide ameliorates liver injury,lipid deposition,and fibrosis in NAFLD mice,through modulation of the TGF-β/SMAD3 pathway and regulating fibrosis-associated protein expression.

To perform the phylogenetic characterization of an isolated porcine rotavirus(PoRV)and investigate its pathogenicity in suckling mice and piglets.A G4P[23]genotype PoRV strain JSJR2023 was successfully isolated from the diarrheic piglet feces through propagation in MA104 cells.The viral proliferation kinetics were analyzed using TCID50 assays,followed by complete genome sequencing through Sanger sequencing platforms.Comprehensive genotyping and phylogenetic reconstruction were conducted using MEGA7.0 with maximum likelihood algorithms.Pathogenicity was assessed in the following animal models:5-day-old C57BL/6 mice and 3-day-old piglets.Multidimensional evaluation included clinical monitoring(diarrhea scoring,growth parameters),virological detection,and histopathological analysis of intestinal tissues.The virus strain JSJR2023 could replicate efficiently in MA104 cells,achieving peak titers of 107.5 TCID50/mL.Whole genome genotype analysis showed that the strain belonged to G4-P[23]-I5-R1-C1-M1-A8-N1-T1-E1-H1.Phylogenetic analysis indicated that the VP3 and NSP4 genes of JSJR2023 strain were most closedrelated to human species rotaviruses,suggesting genetic reassortment between human and porcine RV strains.The animal experiments in suckling mice showed that the JSJR2023 strain infection caused diarrhea symptoms,intestinal edema and congestion,and shedding of intestinal villus epithelial cells.The pathogenicity experiments in piglets showed that compared with the control group,the challenged group of pig-lets had severe diarrhea symptoms,accompanied by reduced appetite and listlessness.Post-mortem examination revealed that the intes-tines were significantly thinner,congested,and filled with yellow watery contents.The challenged piglets showed typical pathological changes such as thinning of the intestinal wall and shortening and shedding of intestinal villi.In conclusion,this study successfully iso-lated a human-porcine recombinant G4P[23]PoRV strain and established the infection models in suckling mice and piglets,providing important tools for investigating the pathogenic mechanism of PoRV,evaluating vaccines and developing antiviral drug.

Objective:To investigate the effectiveness, safety and feasibility of transumbilical laparoendoscopic single-site surgery (TU-LESS) for abdominal wall endometriosis (AWE) lesion resection.Methods:A total of 11 patients who underwent AWE lesion resection via TU-LESS at The First Affiliated Hospital of Nanjing Medical University from January 2022 to May 2024 were enrolled. The size, invasion depth of the lesion, horizontal distance from the lesion center to the original surgical scar, vertical distance from the lesion to the skin, body mass index (BMI), the thickness of abdominal wall fat, operative time, intraoperative blood loss, perioperative complications, postoperative pathology, postoperative incision healing and recurrence were recorded and analyzed.Results:All 11 patients in this study had a history of cesarean section, 10 of whom had transverse incision and 1 had longitudinal incision. The age was (35.0±6.2) years old. BMI was (25.0±4.0) kg/m 2, with the highest being 33.9 kg/m 2. The lesion size was (24.7±12.1) mm, with an average horizontal distance from the lesion center to the original surgical scar of (11.6±6.0) mm. The abdominal wall fat thickness was (21.4±5.8) mm, and the vertical distance from the lesion to the skin was (14.5±7.9) mm. There were a total of 12 lesions in the 11 patients. Among them, 1 lesion extended to the peritoneum inferiorly, 5 lesions extended to the rectus abdominis inferiorly, 5 lesions reached the anterior sheath of the rectus abdominis inferiorly, and 1 lesion was completely located within the abdominal wall fat. The operative time was (84.2±35.4) minutes, and the intraoperative blood loss was (9.0±4.2) ml. The postoperative incision healing of all patients was grade A. The anatomical structure of their umbilical region remained normal, free from any scarring, which contributed to the high satisfaction levels expressed by the patients. Postoperative pathological examination confirmed endometriosis with negative surgical margins, and no recurrence had been observed during follow-up. Conclusion:TU-LESS for AWE lesion resection is safe and feasible, particularly suitable for patients with lesions located far from the original surgical scar, deep lesion location, thick abdominal wall fat, and multiple focal leisons.

Objective·To investigate the effects of liraglutide on liver fibrosis in mice with non-alcoholic fatty liver disease(NAFLD)and the underlying mechanisms.Methods·Twenty 8-week-old C57BL/6J mice were randomly divided into a normal chow diet group(Chow group)and a methionine-choline-deficient(MCD)diet group(MCD group),with 10 mice per group.The MCD diet was used to induce NAFLD.Each group was further divided into two subgroups,resulting in four subgroups:Chow+saline,Chow+liraglutide,MCD+saline,and MCD+liraglutide group.After daily intraperitoneal injection of liraglutide(400 μg/kg)or an equivalent volume of saline for 4 weeks,an intraperitoneal glucose tolerance test(IPGTT)was performed.Serum levels of aspartate transaminase(AST),alanine aminotransferase(ALT),total cholesterol(TC),triglyceride(TAG),high-density lipoprotein cholesterol(HDL-C),and low-density lipoprotein cholesterol(LDL-C)were measured.Liver tissues were collected post-euthanasia to assess TAG content.Histopathological changes,lipid deposition,and fibrosis were evaluated via hematoxylin-eosin(HE)staining,Oil Red O staining,and Masson staining.Real-time quantitative PCR(qPCR)and Western blotting were used to analyze the expression of α-smooth muscle actin(α-SMA),fibronectin(FN),collagen type Ⅰ α(COL1A),matrix metalloproteinase 9(MMP9),tissue inhibitor of metalloproteinase 1(TIMP1),transforming growth factor β(TGF-β),SMAD3,and phosphorylated SMAD3(pSMAD3).Results·The IPGTT revealed that liraglutide intervention reduced blood glucose levels at 15,30,and 60 min,with a decreased area under the curve(AUC)(both P<0.05).Biochemical analysis showed that liraglutide lowered AST and ALT levels(both P<0.001),increased TC and HDL-C levels(both P<0.05),but had no significant effect on TAG or LDL-C in MCD mice.HE staining and Oil Red O staining revealed reduced lipid droplets,ballooning degeneration,and inflammatory infiltration in hepatocytes after liraglutide treatment.Masson staining indicated decreased collagen fiber deposition in the liver.qPCR and Western blotting analysis demonstrated upregulated expression of α-SMA,FN,COL1A,TIMP1,TGF-β,and pSMAD3/SMAD3,alongside downregulated MMP9 in MCD mice.Liraglutide reversed these changes,lowering α-SMA,FN,COL1A,TIMP1,TGF-β,and pSMAD3/SMAD3 expression while increasing MMP9 expression.Conclusion·Liraglutide ameliorates liver injury,lipid deposition,and fibrosis in NAFLD mice,through modulation of the TGF-β/SMAD3 pathway and regulating fibrosis-associated protein expression.

Objectives:To analyze the risk factors of atrial fibrillation in patients with non-obstructive hypertrophic cardiomyopathy(NOHCM)and explore the relationship between left ventricular/atrial volume and atrial fibrillation.Methods:Consecutive NOHCM patients admitted at Fuwai Hospital from January 2023 to January 2024 with complete clinical data,satisfactory echocardiography imaging data were included in this analysis,patients were divided into atrial fibrillation group(n=28)and non-atrial fibrillation group(n=57).Left-sided volumetric and functional parameters were measured by one-beat real-time full-volume three-dimensional echocardiography,including left ventricular end-diastolic volume(LVEDV),left ventricular end-systolic volume(LVESV),left ventricular ejection fraction(LVEF),left atrial volume(LAV).The left ventricular end-diastolic volume(LVEDVi)index,left ventricular end-systolic volume index(LVESVi)and left atrial volume index(LAVi)were calculated.Other echocardiographic parameters including interventricular septum(IVSmax)thickness,left ventricular posterior wall thickness(LVPW),and left atrial diameter(LAD)were routinely measured.Mitral valve forward flow spectrum,tissue Doppler,tricuspid regurgitation velocity,and left atrial size were used to evaluate the left ventricular diastolic function of patients,and diastolic dysfunction was classified into grade I,II,and III.Multivariate logistic regression was used to analyze the influencing factors of atrial fibrillation in patients with non-obstructive hypertrophic cardiomyopathy Results:Compared with the non-atrial fibrillation group,LVEDV([143.8±26.7]ml vs.[117.1±21.9]ml)and LVEDVi([79.4±11.9]ml/m2 vs.[64.2±10.6]ml/m2)were smaller in atrial fibrillation group(both P<0.001).Compared with the non-atrial fibrillation group,LAD([40.2±4.7]mm vs.[48.6±4.8]mm)and LAVi([37.3±8.9]ml/m2 vs.[64.4±17.1]ml/m2)were lager in atrial fibrillation group(both P<0.001).Compared with the non-atrial fibrillation group,the proportion of NYHA functional classification≥Ⅲ was higher(15.8%vs.50.0%,P<0.001),LVEF was lower([61.5±5.5]%vs.[57.6±5.0]%,P=0.002),and proportion of severe diastolic dysfunction was higher in atrial fibrillation group(P<0.001).Logistic regression analysis showed that the factors associated with atrial fibrillation in NOHCM patients were LVEDVi(OR=0.744,95%CI:0.575-0.962,P=0.024)and LAVi(OR=1.602,95%CI:1.032-2.486,P=0.036).Conclusions:LVEDVi and LAVi are related factors for atrial fibrillation in patients with non-obstructive hypertrophic cardiomyopathy.LVEDVi is negatively,while LAVi is positively associated with the occurrence of atrial fibrillation in NOHCM patients.

The lab module of exploratory experiment is newly designed in the practical course of bio-chemistry.Here we describe one of the experimental projects,and it originates from new scientific re-search results on the dynamic structure of ATP synthase.This exploratory experiment is organized in the form of real scientific research,which would fully mobilize the initiative and creativity of students in learning theoretical knowledge and experimental technology.Students work in groups and start with refer-ence reading.Through cooperation,they must develop certain experimental plan,handle samples with photocrosslinking technique and utilize the high-throughput electrophoresis method to analyze the dynamic structural change of ε subunit in ATP synthase under different physiological conditions.High quality re-sults from high-throughput electrophoresis can only be obtained through optimized operation and treat-ment,from which students would experience the process of technological innovation.The teaching process of this lab module embodies the student-centered teaching concept and is widely approved and supported by students.The project of ATP synthase closely combines the content of lab course with cut-ting-edge technology.Students can deeply experience the importance of experimental technology innova-tion in solving scientific problems.The practical ability of students would be comprehensively improved through this lab module.

BACKGROUND:In recent years,numerous studies have shown that autophagy and mitophagy play an important role in the regulation of bone metabolism.Under non-physiological conditions,mitophagy breaks the balance of bone metabolism and triggers metabolism disorders,which affect osteoblasts,osteoclasts,osteocytes,chondrocytes,bone marrow mesenchymal stem cells,etc. OBJECTIVE:To summarize the mechanism of mitophagy in regulating bone metabolic diseases and its application in clinical treatment. METHODS:PubMed,Web of Science,CNKI,WanFang and VIP databases were searched by computer using the keywords of"mitophagy,bone metabolism,osteoblasts,osteoclasts,osteocytes,chondrocytes,bone marrow mesenchymal stem cells"in English and Chinese.The search time was from 2008 to 2023.According to the inclusion criteria,90 articles were finally included for review and analysis. RESULTS AND CONCLUSION:Mitophagy promotes the generation of osteoblasts through SIRT1,PINK1/Parkin,FOXO3 and PI3K signaling pathways,while inhibiting osteoclast function through PINK1/Parkin and SIRT1 signaling pathways.Mitophagy leads to bone loss by increasing calcium phosphate particles and tissue protein kinase K in bone tissue.Mitophagy improves the function of chondrocytes through PINK1/Parkin,PI3K/AKT/mTOR and AMPK signaling pathways.Modulation of mitophagy shows great potential in the treatment of bone diseases,but there are still some issues to be further explored,such as different stages of drug-activated mitophagy,and the regulatory mechanisms of different signaling pathways.