ObjectiveTo investigate the mechanism of Xiezhuo Jiedu prescription in the treatment of ulcerative colitis （UC） by inhibiting ferroptosis and alleviating intestinal mucosal injury based on the nuclear factor E₂ related factor 2/solute carrier family 7 member/glutathione peroxidase 4 （Nrf2/SLC7A11/GPX4） signaling pathway. MethodsA total of 60 male SD rats were divided into a normal group， a model group， high- and low-dose Xiezhuo Jiedu prescription groups （26.64 and 13.32 g·kg^-1， respectively）， a ferroptosis inhibitor group （Ferrostatin-1， 0.005 g·kg^-1）， and a mesalazine group （0.27 g·kg^-1）， with 10 rats in each group. A UC rat model was established by intrarectal administration of trinitrobenzene sulfonic acid （TNBS）-ethanol. The normal group and the model group were intragastrically administered normal saline. The other groups were given intragastric administration according to the corresponding dosage for 7 d. The general condition， disease activity index （DAI） score， colon length， and mucosal injury index （CDMI） score were observed in each group. The pathological changes of colon tissue in each group were observed by hematoxylin-eosin （HE） staining. The intestinal mucosa and mitochondrial morphology in each group were observed by transmission electron microscopy. The expression levels of Occludin， Claudin-1， mucin 2 （MUC2）， and E-cadherin in intestinal tissue were detected by immunofluorescence （IF）. Enzyme-linked immunosorbent assay （ELISA） was used to detect the expression levels of serum tumor necrosis factor-α （TNF-α）， interleukin-6 （IL-6）， and interleukin-10 （IL-10） in each group， and a lactic acid assay kit or ELISA was employed to detect the expression levels of reactive oxygen species （ROS）， ferrous ions （Fe²⁺）， glutathione （GSH）， malondialdehyde （MDA）， 4-hydroxynonenal （4-HNE）， diamine oxidase （DAO）， and D-lactate （D-LA）. Real-time quantitative polymerase chain reaction （Real-time PCR） was applied to detect the mRNA expression levels of Nrf2， SLC7A11， GPX4， Occludin， Claudin-1， MUC2， and E-cadherin in each group， and Western blot was adopted to detect the protein expression levels of Nrf2， p-Nrf2， SLC7A11， and GPX4 in each group. ResultsCompared with the normal group， rats in the model group exhibited listlessness， sluggish response， and mucopurulent and bloody stools. The model group also showed significantly increased DAI score， colon length， CDMI score， and expression levels of TNF-α， IL-6， ROS， Fe²⁺， MDA， 4-HNE， DAO， and D-LA （P<0.01）. In addition， it presented significantly decreased IF values of Occludin， Claudin-1， MUC2， and E-cadherin and mRNA and protein expression levels of IL-10， GSH， Nrf2， p-Nrf2， SLC7A11， and GPX4 （P<0.01）. There were different degrees of improvement in each administration group after treatment， and the improvement was the most significant in the high-dose Xiezhuo Jiedu prescription group （P<0.01）. ConclusionXiezhuo Jiedu prescription may alleviate intestinal mucosal injury by inhibiting ferroptosis of intestinal epithelial cells via regulating the Nrf2/SLC7A11/GPX4 signaling pathway， thereby exhibiting efficacy in the treatment of UC.

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.

Childhood primary renal tubular diseases are chronic kidney diseases characterized by impaired renal tubular reabsorption. Primary renal tubular disease has diverse clinical manifestations and lacks of specificity. Laboratory tests are limited，making it prone to missed diagnosis and misdiagnosis. Based on the current knowledge of renal tubular diseases，authors propose early warning signals of renal tubular diseases such as family history of primary tubular diseases，unexplained polyhydramnios during pregnancy，polydipsia，polyuria，delayed growth and development or rickets，decreased muscle strength and tone，unexplained electrolyte disturbance，hyperuricemia，acid-base disturbance，positive urine sugar test，renal tubular proteinuria，urinary imaging examination suggesting kidney stones，calcium deposition，renal cysts and early onset of eye，ear，joint and neuron injury.Meanwhile，some universal management strategies for primary renal tubular disease are proposed，emphasizing the importance of multidisciplinary collaboration，genetic testing and individualized intervention to improve the long-term prognosis of childhood primary renal tubular diseases.

Objective To investigate the levels of hypoxia-inducible factor 1α(HIF-1α)and lipopolysaccha-ride signal receptor(CD14)in gingival crevicular fluid of preschool children with dental caries and their clini-cal significance.Methods A total of 468 preschool children(aged 3-6 years)who underwent oral examina-tions in the hospital from April 2022 to May 2024 were selected as the research objects and were divided into the observation group(with dental caries,n=107)and the healthy group(without dental caries,n=361)based on the presence or absence of dental caries.The observation group was further divided into three sub-groups according to the degree of caries activity test(CAT)score:low activity group(n=29),moderate activ-ity group(n=46),and high activity group(n=32).The children in the observation group were followed up for 6 months,and then divided into the occurrence group(n=36)and the non-occurrence group(n=71)based on whether chronic apical periodontitis occurred during the follow-up period.The levels of HIF-1α and CD14 in gingival crevicular fluid in the research objects were detected.The relationship between the levels of HIF-1α and CD14 in gingival crevicular fluid of preschool children with dental caries and CAT score was ex-plored by Pearson correlation analysis.The predictive value of HIF-1α and CD14 levels in gingival crevicular fluid for chronic apical periodontitis in preschool children with dental caries was explored by receiver operating characteristic(ROC)curve.Results The levels of HIF-1α and CD14 in gingival crevicular fluid in the obser-vation group were higher than those in the healthy group(P＜0.05).With the increase of CAT score,the lev-els of HIF-1α and CD14 in gingival crevicular fluid gradually increased(high activity group＞moderate activi-ty group＞low activity group),and the differences were statistically significant(P＜0.05).The levels of HIF-1α and CD14 in gingival crevicular fluid of preschool children with dental caries were positively correlated with CAT score(r=0.526,0.634,P＜0.001).The levels of HIF-1α and CD14 in gingival crevicular fluid in the occurrence group were significantly higher than those in the non-occurrence group(P＜0.05).ROC curve analysis showed that the area under the curve(AUC)of combined prediction of HIF-1α and CD14 levels in gingival crevicular fluid for chronic apical periodontitis in preschool children with dental caries was 0.902(95％CI:0.857-0.952),which was higher than 0.709(95％CI:0.664-0.759)and 0.825(95％CI:0.775-0.870)of individual prediction of HIF-1α and CD14 levels in gingival crevicular fluid.Conclusion HIF-1α and CD14 are highly expressed in gingival crevicular fluid of preschool children with dental caries,and their levels are related to the activity of dental caries and the occurrence of chronic apical periodontitis in preschool chil-dren with dental caries.The combined detection of the two can be used as effective indicators for predicting the occurrence of chronic apical periodontitis in preschool children with dental caries.

Objective:To develop and validate a Self-care Ability Scale for Arteriovenous Fistula (AVF) in Maintenance Hemodialysis (MHD) patients.Methods:Guided by Orem's self-care theory, the initial item pool of the scale was developed through a literature review, semi-structured interviews, and group discussions. The initial scale was finalized after two rounds of expert consultation using the Delphi method. A convenience sampling method was used to recruit 418 MHD patients using AVF in January 2024 for item analysis, exploratory factor analysis and reliability testing. Another 293 MHD patients using AVF were recruited in March 2024 for confirmatory factor analysis.Results:The self-care ability scale for AVF in MHD patients included four dimensions: knowledge and skills of AVF self-care, willingness and attitude toward AVF self-care, recognition and prevention of AVF complications, and patient self-adjustment and adaptation, comprising 38 items. The content validity index at the scale level was 0.98. Exploratory factor analysis extracted four common factors with a cumulative variance contribution rate of 84.706%. Confirmatory factor analysis indicated good model fit, strong convergent validity, and ideal discriminant validity. The total Cronbach's α coefficient of the scale was 0.987; the split-half reliability coefficient was 0.902, and the test-retest reliability coefficient was 0.979.Conclusions:The Self-care Ability Scale for AVF in MHD patients demonstrates excellent reliability and validity, making it a suitable tool for assessing patients' ability to self-care for their AVF.

Objectives:To investigate the clinical efficacy of Schroth scoliosis-specific exercises combined with three-dimensional traction therapy in spinal-pelvic remodeling for adolescents idiopathic scoliosis(AIS).Methods:80 AIS patients who received treatment at our hospital from June 2021 to June 2024 were en-rolled.They were randomly divided into a control group(n=40,received Schroth spinal scoliosis-specific cor-rection exercises alone)and a research group(n=40,underwent a combination of Schroth spinal scoliosis-spe-cific correction exercises and three-dimensional traction therapy)using a random number table method.The general demographic data of the two groups were well-balanced(P＞0.05).The clinical overall response rates of the two groups were compared,and spinal-pelvic remodeling indicators,including Cobb angle,angle of trunk inclination(ATI),angle of trunk rotation(ATR),C7 plumb line to the center sacral vertical line(C7-CSVL),api-cal vertebral translation(AVT),as well as median frequency(MF),mean power frequency(MPF),and average electromyography(AEMG)of the surface electromyography of the erector spinae muscles on the concave and convex sides,pelvic tilt(PT),pelvic incidence(PI),and sacral slope(SS),were assessed before treatment,at 1 month and 3 months after treatment.Repeated measures analysis of variance was conducted to test the main effects of spinal-pelvic remodeling indicators during the treatment period for both groups.Pearson correlation analysis was performed to examine the relationship between the Oswestry disability index(ODI)score and spinal-pelvic remodeling indicators.Results:The total effective treatment rate was significantly higher in the research group than in the control group(97.50％vs 67.50％,P＜0.001).Compared with the pre-treatment val-ues,the Cobb angle,ATI,and ATR of both groups decreased at 1 month and 3 months post-treatment(P＜0.05).Moreover,when compared with the control group,the research group showed a more pronounced de-crease in Cobb angle,ATI,and ATR at 1 month and 3 months post-treatment(P＜0.05).Both groups exhibited a decrease in PI and SS,along with an increase in PT at 1 month and 3 months post-treatment(P＜0.05).In comparison with the control group,the research group demonstrated a more significant decrease in PI and SS,and a more pronounced increase in PT at 1 month and 3 months post-treatment(P＜0.05).The C7-CSVL and AVT of both groups decreased at 1 month and 3 months post-treatment(P＜0.05),and the research group showed a more significant decrease in C7-CSVL and AVT compared with the control group at 1 month and 3 months post-treatment(P＜0.05).Both groups experienced an increase in MF,MPF,and AEMG of the sur-face electromyography of the erector spinae muscles at 1 month and 3 months post-treatment(P＜0.05),with the research group showing a more significant increase compared with the control group at 1 month and 3 months post-treatment(P＜0.05).The main effect tests revealed statistically significant time effects,inter-group effects,and interaction effects for the spinal-pelvic remodeling indicators during the treatment period(P＜0.05).The Cobb angle,ATI,ATR,C7-CSVL,AVT,MF,AEMG,MPF,PI,PT,and SS were all found to be corre-lated with the ODI score before and after treatment(P＜0.05).The decrease in the ODI score of study group after treatment was significantly better than that of control group(β=-6.178,P＜0.001).Conclusions:Schroth scoliosis-specific exercises combined with three-dimensional traction therapy significantly improve spinal-pelvic remodeling in AIS patients,effectively reducing spinal curvature and enhancing pelvic symmetry.

Objectives:To investigate the clinical efficacy of Schroth scoliosis-specific exercises combined with three-dimensional traction therapy in spinal-pelvic remodeling for adolescents idiopathic scoliosis(AIS).Methods:80 AIS patients who received treatment at our hospital from June 2021 to June 2024 were en-rolled.They were randomly divided into a control group(n=40,received Schroth spinal scoliosis-specific cor-rection exercises alone)and a research group(n=40,underwent a combination of Schroth spinal scoliosis-spe-cific correction exercises and three-dimensional traction therapy)using a random number table method.The general demographic data of the two groups were well-balanced(P＞0.05).The clinical overall response rates of the two groups were compared,and spinal-pelvic remodeling indicators,including Cobb angle,angle of trunk inclination(ATI),angle of trunk rotation(ATR),C7 plumb line to the center sacral vertical line(C7-CSVL),api-cal vertebral translation(AVT),as well as median frequency(MF),mean power frequency(MPF),and average electromyography(AEMG)of the surface electromyography of the erector spinae muscles on the concave and convex sides,pelvic tilt(PT),pelvic incidence(PI),and sacral slope(SS),were assessed before treatment,at 1 month and 3 months after treatment.Repeated measures analysis of variance was conducted to test the main effects of spinal-pelvic remodeling indicators during the treatment period for both groups.Pearson correlation analysis was performed to examine the relationship between the Oswestry disability index(ODI)score and spinal-pelvic remodeling indicators.Results:The total effective treatment rate was significantly higher in the research group than in the control group(97.50％vs 67.50％,P＜0.001).Compared with the pre-treatment val-ues,the Cobb angle,ATI,and ATR of both groups decreased at 1 month and 3 months post-treatment(P＜0.05).Moreover,when compared with the control group,the research group showed a more pronounced de-crease in Cobb angle,ATI,and ATR at 1 month and 3 months post-treatment(P＜0.05).Both groups exhibited a decrease in PI and SS,along with an increase in PT at 1 month and 3 months post-treatment(P＜0.05).In comparison with the control group,the research group demonstrated a more significant decrease in PI and SS,and a more pronounced increase in PT at 1 month and 3 months post-treatment(P＜0.05).The C7-CSVL and AVT of both groups decreased at 1 month and 3 months post-treatment(P＜0.05),and the research group showed a more significant decrease in C7-CSVL and AVT compared with the control group at 1 month and 3 months post-treatment(P＜0.05).Both groups experienced an increase in MF,MPF,and AEMG of the sur-face electromyography of the erector spinae muscles at 1 month and 3 months post-treatment(P＜0.05),with the research group showing a more significant increase compared with the control group at 1 month and 3 months post-treatment(P＜0.05).The main effect tests revealed statistically significant time effects,inter-group effects,and interaction effects for the spinal-pelvic remodeling indicators during the treatment period(P＜0.05).The Cobb angle,ATI,ATR,C7-CSVL,AVT,MF,AEMG,MPF,PI,PT,and SS were all found to be corre-lated with the ODI score before and after treatment(P＜0.05).The decrease in the ODI score of study group after treatment was significantly better than that of control group(β=-6.178,P＜0.001).Conclusions:Schroth scoliosis-specific exercises combined with three-dimensional traction therapy significantly improve spinal-pelvic remodeling in AIS patients,effectively reducing spinal curvature and enhancing pelvic symmetry.

Objective To explore the mediating role of activities of daily living (ADL) in pain and depressive symptoms in the elderly in China. Methods Utilizing the data from 2020 China Health and Retirement Longitudinal Study, 4403 Chinese elderly individuals aged ≥ 60 years old were selected as the research subjects. Depression Scale (CES-D 10) of the Center for Epidemiological Survey and ADL scale were used in the study. The PROCESS4.1 macro was used to test the mediating effect of daily living activities between pain and depressive symptoms, and the Bootstrap method was applied for verification of the mediating variables. Results A total of 2368 cases of depressive symptoms were detected in the elderly in China, with a detection rate of 53.78%. Pain was positively correlated with depressive symptoms (r=0.27, P<0.01), and activities of daily living were negatively correlated with pain and depressive symptoms (r=-0.27, -0.337, P<0.01). The results showed that the total effect value of pain on depressive symptoms was 0.33, the direct effect value was 0.24, and the mediating effect value of daily living activities was 0.09, accounting for 27.27%. Conclusion Pain and activities of daily living are important factors influencing depressive symptoms in the elderly, and activities of daily living play a partial mediating role in the relationship between pain and depressive symptoms in the elderly.

BACKGROUND:Mammary stem cells are vital for the development and homeostasis of mammary gland tissue.The occurrence of breast cancer has a close relationship with the mammary stem cells.Recent studies have shown that Hopx,as an important transcriptional regulator of morphogenesis and cell differentiation,has been confirmed to be expressed in a variety of adult stem cells such as nerves,intestines,hair follicles and lungs.However,its role in mammary stem cells has not been reported so far.OBJECTIVE:To investigate whether Hopx expression marks mammary stem cells.METHODS:(1) Female Hopx-LacZ transgenic mice aged 8 weeks were selected to detect the background expression of Hopx in breast tissue by β-galactosidase staining.(2) Female wild-type mice at 4,6,and 8 weeks of age and 14.5 days of gestation were selected for whole-tissue magenta staining and K14 and K8 immunofluorescence staining,respectively.(3) Female Hopx-CreERT2;Rosa26LacZ transgenic mice aged 8 weeks and 17.5 days of gestation were selected and stained with breast β-galactosidase.(4) The 4-week-old female Hopx-CreERT2;Rosa26LacZ transgenic mice were selected.The Cre/loxp system was activated by intraperitoneal injection of tamoxifen (once every other day,three times),and breast β-galactosidase staining was performed 4 weeks after injection.The 8-week-old female Hopx-CreERT2;Rosa26LacZ transgenic mice were selected.The Cre/loxp system was activated by intraperitoneal injection of tamoxifen (once every other day,three times),and breast β-galactosidase staining was performed 4 and 10 weeks after the last injection.(5) Female Hopx-CreERT2;Rosa26LacZ transgenic mice aged 8 weeks were selected.The Cre/loxp system was activated by intraperitoneal injection of tamoxifen (once every other day,three times).Hopx-CreERT2;Rosa26LacZ transgenic mice were pregnant 2 weeks after injection.The mammary tissue of mice at 17.5 days of the first pregnancy and 17.5 days of the third pregnancy was stained with β-galactosidase.RESULTS AND CONCLUSION:(1) The results of β-galactosidase staining showed that the mammary ducts of Hopx-LacZ transgenic mice at 8 weeks of age did contain Hopx-positive cells and were located in the basal epithelia,with a small number.(2) Whole-mount staining of mammary glands and immunofluorescence staining results exhibited that the mammary glands of mice had different characteristics with corresponding developmental stages such as puberty,maturity,and pregnancy,and underwent a series of complex epithelial remodeling processes.(3) The results of β-galactosylase staining showed that Hopx-labeled positive cells in the mammary duct of Hopx-CreERT2;Rosa26LacZ transgenic mice at 17.5 days of gestation increased compared with female Hopx-CreERT2;Rosa26LacZ transgenic mice at 8 weeks of age.(4) The results of β-galactosylase staining showed that the Hopx-labeled positive cells in the mammary glands of 4-and 8-week-old female Hopx-CreERT2;Rosa26LacZ transgenic mice after tamoxifen injection were located in the basal epithelium with a small number.(5) The results of β-galactosidase staining showed that Hopx-labeled positive cells in the mammary glands of mice at 17.5 days of the first and third gestation were located in the basal epithelia around the alveoli,and the number of Hopx-labeled positive cells at 17.5 days of the third gestation was more.(6) In conclusion,Hopx reporter-marked basal epithelial cells belong to dormant mammary stem cells,which are responsible for the growth of the mammary glands during pregnancy and contribute to acinar formation.

Objective:To compare the protective effects of the static cold storage (SCS) and normothermic machine perfusion (NMP) on the skeletal muscle of the amputated limbs of pigs.Methods:Four Landrace pigs were selected, from which eight limbs were amputated and divided into SCS group ( n=5) and NMP group ( n=3) according to the random number table method. After blood collection from the carotid artery, an amputated limb model was established by amputating the limbs at the scapulohumeral joints. The limbs in the SCS group were wrapped in sterile cloth and stored at 4 ℃ for 24 hours. In the NMP group, the limbs were mechanically perfused with a red blood cell-containing perfusion fluid at 37 ℃ for 24 hours, with 70% of the perfusion fluid replaced every 6 hours. Before the experiment, cross-matching tests with the saline medium were conducted between donor and recipient pigs to evaluate blood coagulation and blood safety in the NMP group. An allogeneic red blood cell perfusion fluid was prepared and the levels of pH, Na +, K +, Cl -, Ca 2+, glucose (Glu), hematocrit (Hct), lactic acid (Lac) and osmotic pressure of the perfusion fluid were measured. At 0, 6, 12, 18, and 24 hours after perfusion, the skin temperature and oxyhemoglobin saturation (SaO 2) levels in the NMP group were monitored and the levels of pH, Glu, creatine kinase (Ck), K +, Ca 2+, and Na +levels of the perfusion fluid were analyzed to evaluate the metabolism of the skeletal muscle in the amputated limbs. The mean intercellular distance and apoptosis index of the myocytes were quantitatively analyzed and histopathological changes were observed by performing HE staining and TUNEL staining on the skeletal muscle of the amputated limbs in both groups at 0 and 24 hours after perfusion. After perfusion was ended, the weight gain rate and swelling degree of the amputated limbs were compared between the two groups and the overall state of the amputated limbs was evaluated. Results:The result of the cross-matching test between donor and recipient pig blood was negative. The parameters in the prepared red blood cell-containing perfusion fluid generally maintained within a normal range: pH 7.38±0.04, Na + concentration (138.30±4.48)mmol/L, K + concentration (3.50±0.26)mmol/L, Glu concentration (6.11±2.08)mmol/L, and osmotic pressure (305.67±3.79)mmol/L. However, slightly higher Cl - and Ca 2+ concentrations [(118.34±12.00)mmol/L and (2.00±0.15)mmol/L] and lower Hct and lactate concentrations [0.30±0.03 and (1.54±0.38)mmol/L] were detected when compared with the reference range. During the perfusion, the average skin temperature of the amputated limbs in the NMP group was (36.13±0.98)℃, with the skin temperatures at 6, 12, 18, and 24 hours after perfusion being significantly higher than that at 0 hour ( P<0.01), while no significant difference among the skin temperatures at 6, 12, 18, and 24 hours after perfusion was observed ( P>0.05). The SaO 2 levels in the skin of the amputated limbs in the NMP group averaged over 95%, which showed no significant difference at 0, 12, 18, and 24 hours after perfusion ( P>0.05), while a significant elevation was observed at 6 hours compared with that at 0 hour ( P<0.05). There were no significant differences in pH, Glu, Na +, and Ca 2+ levels in the NMP group at 0, 6, 12, 18, and 24 hours after perfusion ( P>0.05), while the Ck levels at 18 and 24 hours were both significantly higher than that at 6 hours after perfusion ( P<0.05), and the Ck levels at 6, 12, 18, and 24 hours were all significantly higher than that at 0 hour ( P<0.05). The K + level progressively increased with the perfusion time, with significant elevations at 18 and 24 hours after perfusion compared with that at 0 hour ( P<0.05). HE staining revealed well-preserved muscle fiber continuity and regular arrangement in the NMP group and the SCS group at 0 hour, with an intercellular distance of (8.95±0.60)μm. At 24 hours, the NMP group exhibited slight skeletal muscle fiber rupture and swelling, with a slightly increased intercellular distance of (14.75±0.90)μm, significantly greater than that at 0 hour ( P<0.01). At 24 hours, the SCS group showed marked skeletal muscle fiber rupture and swelling, with a significantly increased intercellular distance of (23.51±1.49)μm, significantly larger than those at 0 hour in the same group and at 24 hours in the NMP group ( P<0.01). TUNEL immunofluorescence staining indicated a tiny amount of apoptotic cells in the skeletal muscle in both groups at 0 hour, with an apoptotic index of (4.26±1.62)%. There was a small number of apoptotic cells in the skeletal muscle in the NMP group at 24 hours, with an apoptotic index of (25.94±2.69)%, significantly larger than that in the same group at 0 hour ( P<0.01). The SCS group exhibited a large number of apoptotic cells at 24 hours, with an apoptotic index of (62.97±3.22)%, significantly larger than those at 0 hour in the same group and at 24 hours in the NMP group ( P<0.01). In comparison with the SCS group at 24 hours, the amputated limbs in the NMP group showed red color in the appearance, no symptoms of ischemic muscle contracture and good joint movement despite slight edema in the subcutaneous layer. At 24 hours, the weight gain rate of the amputated limbs was (15.82±0.89)% in the NMP group, significantly higher than (0.97±0.28)% in the SCS group ( P<0.01). Conclusion:Compared with SCS, NMP with the red blood cell-containing perfusion fluid prepared with the allogeneic blood for the amputated limbs of pigs can alleviate the ischemic injury of the muscle fibers and inhibit the apoptosis of the muscle cells by sustaining stable energy and oxygen supply and balancing ion homeostasis and pH of the perfusion fluid.