Objective:To investigate the survival outcomes and prognostic factors in patients undergoing radical resection for pancreatic body and tail cancer.Methods:A retrospective case series study was conducted on 992 patients who underwent radical resection for pancreatic body and tail cancer at the Pancreatic Center of the First Affiliated Hospital of Nanjing Medical University from January 2016 to June 2024. In this study, 577 (58.2%) were male and 415 (41.8%) were female,with an age of (65±9) years (range: 26 to 86 years). Follow-up continued until June 2024. Survival rates were estimated using the Kaplan-Meier method,and prognostic factors were identified using univariate and multivariate Cox proportional hazards models.Results:Among 992 patients,open surgery was the predominant approach (89.1%, 884/992), and radical antegrade modular pancreatosplenectomy (RAMPS) was performed in 317 patients (32.0%). Combined organ resection,venous resection,and arterial resection were performed in 23.5%, 9.3%,and 11.2% of patients,respectively. The rates of R0, R1-1 mm, and R1-direct resections were 49.8% (494/992),41.5% (412/992), and 8.7% (86/992),respectively. Stage ⅡB was the most common TNM stage (32.2%,319/992). A total of 801 patients (80.8%) received adjuvant chemotherapy. The median follow-up period was 32.0(8.8) months(range:3.2 to 105.3 months),during which 508 patients (51.2%) died. The overall median survival (OS) was 26.4 months,with 1-,3-, and 5-year survival rates of 79.0%,40.0%, and 29.0%, respectively. In the recent five years (from 2020 to 2024), the median OS improved significantly to 34.1 months compared to 20.0 months from 2016 to 2019 ( P<0.01). Histological subtype analysis showed that the median OS time was 26.7 months for pancreatic ductal adenocarcinoma (PDAC, n=855),58.9 months for invasive intraductal papillary mucinous carcinoma (IPMC, n=32),and 15.7 months for adenosquamous carcinoma of pancreas (ASCP, n=73) ( P=0.001). Among PDAC patients, adjuvant chemotherapy significantly improved survival (29.1 months vs. 14.4 months, P<0.01);in IPMC patients, adjuvant chemotherapy also extended survival (65.7 months vs. 58.9 months, P=0.047). Although ASCP patients receiving chemotherapy had a longer median OS time than those without (18.8 months vs. 8.9 months),the difference was not statistically significant ( P=0.151). Multivariate Cox regression analysis in PDAC patients indicated that adjuvant chemotherapy, R0 resection, T stage,N stage,and tumor differentiation were independent prognostic factors ( P<0.01). The median OS time by TNM stage was:not reached for stage ⅠA, 51.6 months for ⅠB, 25.5 months for ⅡA, 23.7 months for ⅡB, 23.0 months for Ⅲ, and 14.4 months for Ⅳ. The median OS time for R0,R1-1 mm,and R1-direct resections was 34.1,24.7,and 15.7 months,respectively ( P<0.01). Conclusion:Adjuvant chemotherapy,R0 resection,tumor stage,and differentiation are independent prognostic factors for pancreatic body and tail cancer.

Objective:To investigate the survival outcomes and prognostic factors in patients undergoing radical resection for pancreatic body and tail cancer.Methods:A retrospective case series study was conducted on 992 patients who underwent radical resection for pancreatic body and tail cancer at the Pancreatic Center of the First Affiliated Hospital of Nanjing Medical University from January 2016 to June 2024. In this study, 577 (58.2%) were male and 415 (41.8%) were female,with an age of (65±9) years (range: 26 to 86 years). Follow-up continued until June 2024. Survival rates were estimated using the Kaplan-Meier method,and prognostic factors were identified using univariate and multivariate Cox proportional hazards models.Results:Among 992 patients,open surgery was the predominant approach (89.1%, 884/992), and radical antegrade modular pancreatosplenectomy (RAMPS) was performed in 317 patients (32.0%). Combined organ resection,venous resection,and arterial resection were performed in 23.5%, 9.3%,and 11.2% of patients,respectively. The rates of R0, R1-1 mm, and R1-direct resections were 49.8% (494/992),41.5% (412/992), and 8.7% (86/992),respectively. Stage ⅡB was the most common TNM stage (32.2%,319/992). A total of 801 patients (80.8%) received adjuvant chemotherapy. The median follow-up period was 32.0(8.8) months(range:3.2 to 105.3 months),during which 508 patients (51.2%) died. The overall median survival (OS) was 26.4 months,with 1-,3-, and 5-year survival rates of 79.0%,40.0%, and 29.0%, respectively. In the recent five years (from 2020 to 2024), the median OS improved significantly to 34.1 months compared to 20.0 months from 2016 to 2019 ( P<0.01). Histological subtype analysis showed that the median OS time was 26.7 months for pancreatic ductal adenocarcinoma (PDAC, n=855),58.9 months for invasive intraductal papillary mucinous carcinoma (IPMC, n=32),and 15.7 months for adenosquamous carcinoma of pancreas (ASCP, n=73) ( P=0.001). Among PDAC patients, adjuvant chemotherapy significantly improved survival (29.1 months vs. 14.4 months, P<0.01);in IPMC patients, adjuvant chemotherapy also extended survival (65.7 months vs. 58.9 months, P=0.047). Although ASCP patients receiving chemotherapy had a longer median OS time than those without (18.8 months vs. 8.9 months),the difference was not statistically significant ( P=0.151). Multivariate Cox regression analysis in PDAC patients indicated that adjuvant chemotherapy, R0 resection, T stage,N stage,and tumor differentiation were independent prognostic factors ( P<0.01). The median OS time by TNM stage was:not reached for stage ⅠA, 51.6 months for ⅠB, 25.5 months for ⅡA, 23.7 months for ⅡB, 23.0 months for Ⅲ, and 14.4 months for Ⅳ. The median OS time for R0,R1-1 mm,and R1-direct resections was 34.1,24.7,and 15.7 months,respectively ( P<0.01). Conclusion:Adjuvant chemotherapy,R0 resection,tumor stage,and differentiation are independent prognostic factors for pancreatic body and tail cancer.

Objective:To analyze the effect of emodin on apoptosis and oxidative damage of PC12 cells induced by hypoxia/re-oxygenation and its corresponding mechanism.Methods:PC12 cells were cultured in vitro and their neural differentiation was induced.Cells were divided into control group,model group,low concentration emodin group(30 mmol/L),high concentration emodin group(90 mmol/L)and high concentration emodin+GW441756(90 mmol/L+6.3 μmol/L)group,excepted for control group,other groups were treated with hypoxia and reoxygenation,and viability of PC12 cells was determined by CCK-8 method;levels of LDH release,SOD,MDA,IL-1β and TNF-α were measured by kits;PC12 cell apoptosis was detected by flow cytometry,expressions of nerve growth factor(NGF)/tropomyosin receptor kinase A(TrkA)pathway proteins in PC12 cells were determined by Western blot.Results:Compared with control group,PC12 cell activity,SOD level,NGF,and p-TrkA/TrkA in model group were decreased(P<0.05),while LDH release,apoptosis rate,MDA,IL-1β and TNF-α levels were increased(P<0.05);compared with model group,PC12 cell activity,SOD level,NGF,and p-TrkA/TrkA in low concentration emodin group and high concentration emodin group were increased(P<0.05),while LDH release,apoptosis rate,MDA,IL-1β and TNF-α levels were decreased(P<0.05);compared with high concen-tration emodin group,PC12 cell activity,SOD level,NGF,and p-TrkA/TrkA in high concentration emodin+GW441756 group were decreased(P<0.05),while LDH release,apoptosis rate,MDA,IL-1β and TNF-α levels were increased(P<0.05).Conclusion:Emodin can inhibit oxidative stress and inflammatory damage of PC12 cells induced by hypoxia/reoxygenation,and inhibit apoptosis by activating NGF/TrkA pathway.

Cardiovascular disease is one of the serious health burdens in the world,and atherosclerosis is its impor-tant pathological basis.In recent years,the effect of environmental pollutants on human health has been paid more and more attention.Some new epidemiological studies and experiments have reported that environmental organic pollutants,involved in the occurrence and development of atherosclerosis,is an independent risk factor of cardiovascular diseases.Evidence shows that it is related to oxidative stress response,cell phenotype transformation,dyslipidemia,genetic changes and so on.This review summarizes available studies on the latest epidemiological studies and experiments of typical per-sistent organic pollutants such as polychlorinated biphenyls and per-and polyfluoroalkyl substances so as to provide refer-ences for future research.

Objective To investigate the expression levels of microRNA-34a(miR-34a),β-catenin and pro-grammed death receptor-1(PD-L1)in cancer tissues of patients with cervical cancer(CC)and their correla-tion with patients' prognosis.Methods A total of 83 patients with CC admitted to Yuncheng Central Hospital Affiliated to Shanxi Medical University from June 2021 to January 2024 were selected as the research objects.General data,CC tissue and adjacent normal tissue samples of all patients were collected.The mRNA expres-sion levels of miR-34a,β-catenin and PD-L1 in CC tissues and adjacent normal tissues were detected by fluo-rescence quantitative PCR and compared.The expression levels of β-catenin and PD-L1 in CC tissues and adja-cent normal tissues were detected by immunohistochemistry.Multivariate Logistic regression analysis was used to analyze the influencing factors of prognosis in CC patients.Receiver operating characteristic(ROC)curve was used to analyze the predictive value of miR-34a,β-catenin and PD-L1 expression levels in CC pa-tients with poor prognosis.Results Compared with adjacent normal tissues,the expression level of miR-34a of the CC tissues was lower,while the expression levels of β-catenin and PD-L1 were higher(P＜0.05).The positive expression rates of β-catenin and PD-L1 protein in CC tissues were higher than those of adjacent nor-mal tissues(89.16％vs.10.84％,78.31％vs.20.48％,x2=101.807,55.526,P＜0.05).There were no sig-nificant differences in age and body mass index(BMI)between the good prognosis group and the poor progno-sis group(t=1.508,1.820,both P＞0.05),while there were significant differences in International Federa-tion of Gynecology and Obstetrics(FIGO)stage and differentiation degree between the two groups(x2=8.451,9.115,both P＜0.05).Compared with the good prognosis group,the expression level of miR-34a of the poor prognosis group was lower,while the expression levels of β-catenin and PD-L1 were higher(P＜0.05).Multivariate Logistic regression analysis showed that increased expression of miR-34a was an protective factor for poor prognosis in CC patients,while the increased expression levels of β-catenin and PD-L1,Ⅱ a and Ⅱ b FIGO staging and low differentiation were independent risk factors for poor prognosis in CC patients(P＜0.05).ROC curve analysis showed that miR-34a,β-catenin and PD-L1 all had certain predictive value for the poor prognosis of CC patient,and the area under the curve(AUC)of the single detection was 0.765,0.836 and 0.797,respectively.The AUC of the combined detection was 0.914(Z=2.631,2.331,2.571,P=0.009,0.020,0.010).Conclusion The expression levels of miR-34a,β-catenin and PD-L1 mRNA affect the prognosis of CC patients.Increased expression of miR-34a is an protective factor for poor prognosis in CC patients,in-creased β-catenin and PD-L1 expressions are independent risk factors for poor prognosis in CC patients,and all three factors can be used as biomarkers to predict poor prognosis in CC patients,and the combined detection of the three has the highest prognostic value.

Objective:To analyze the effect of emodin on apoptosis and oxidative damage of PC12 cells induced by hypoxia/re-oxygenation and its corresponding mechanism.Methods:PC12 cells were cultured in vitro and their neural differentiation was induced.Cells were divided into control group,model group,low concentration emodin group(30 mmol/L),high concentration emodin group(90 mmol/L)and high concentration emodin+GW441756(90 mmol/L+6.3 μmol/L)group,excepted for control group,other groups were treated with hypoxia and reoxygenation,and viability of PC12 cells was determined by CCK-8 method;levels of LDH release,SOD,MDA,IL-1β and TNF-α were measured by kits;PC12 cell apoptosis was detected by flow cytometry,expressions of nerve growth factor(NGF)/tropomyosin receptor kinase A(TrkA)pathway proteins in PC12 cells were determined by Western blot.Results:Compared with control group,PC12 cell activity,SOD level,NGF,and p-TrkA/TrkA in model group were decreased(P<0.05),while LDH release,apoptosis rate,MDA,IL-1β and TNF-α levels were increased(P<0.05);compared with model group,PC12 cell activity,SOD level,NGF,and p-TrkA/TrkA in low concentration emodin group and high concentration emodin group were increased(P<0.05),while LDH release,apoptosis rate,MDA,IL-1β and TNF-α levels were decreased(P<0.05);compared with high concen-tration emodin group,PC12 cell activity,SOD level,NGF,and p-TrkA/TrkA in high concentration emodin+GW441756 group were decreased(P<0.05),while LDH release,apoptosis rate,MDA,IL-1β and TNF-α levels were increased(P<0.05).Conclusion:Emodin can inhibit oxidative stress and inflammatory damage of PC12 cells induced by hypoxia/reoxygenation,and inhibit apoptosis by activating NGF/TrkA pathway.

Cardiovascular disease is one of the serious health burdens in the world,and atherosclerosis is its impor-tant pathological basis.In recent years,the effect of environmental pollutants on human health has been paid more and more attention.Some new epidemiological studies and experiments have reported that environmental organic pollutants,involved in the occurrence and development of atherosclerosis,is an independent risk factor of cardiovascular diseases.Evidence shows that it is related to oxidative stress response,cell phenotype transformation,dyslipidemia,genetic changes and so on.This review summarizes available studies on the latest epidemiological studies and experiments of typical per-sistent organic pollutants such as polychlorinated biphenyls and per-and polyfluoroalkyl substances so as to provide refer-ences for future research.

Objective:To investigate the clinical efficacy of pancreaticoduodenectomy (PD) for periampullary diseases.Methods:The retrospective cohort study was conducted. The clinico-pathological data of 2 019 patients with periampullary diseases who underwent PD in the First Affiliated Hospital of Nanjing Medical University from January 2016 to December 2020 were collected. There were 1 193 males and 826 females, aged 63(15) years. Observation indicators: (1) surgical situations; (2) postoperative conditions; (3) postoperative pathological examinations; (4) prognosis of patients with periampullary carcinoma. Regular follow-up was conducted by telephone interview and outpatient examination once every 3 months within the postoperative first year and once every 6 months thereafter to detect the survival of patients with periampullary carcinoma. The follow-up was up to December 2021. Measurement data with skewed distribution were represented as M(IQR) or M(range), and comparison between groups was analyzed using the rank sum test. Count data were described as absolute numbers and (or) percentages, and comparison between groups was analyzed by the chi-square test or Fisher exact probability. Kaplan-Meier method was used to draw survival curves and calculate survival rates, and Log-Rank test was used to conduct survival analysis. Results:(1) Surgical situations: of 2 019 patients, 1 116 cases were admitted from 2016-2018 and 903 cases were admitted from 2019-2020. There were 1 866 cases undergoing open PD and 153 cases undergoing laparoscopic or robot-assisted PD. There were 1 049 cases under-going standard PD and 970 cases undergoing pylorus-preserved PD. There were 215 cases combined with portal mesenteric vein resection, 3 cases combined with arterial resection. The operation time of 2 019 patients was 255(104)minutes and the volume of intraoperative blood loss was 250(200)mL. The intraoperative blood transfusion rate was 31.401%(623/1 984), with the blood transfusion data of 35 cases missing. The proportions of pylorus-preservation, combination with portal mesenteric vein resection, intraoperative blood transfusion were 585 cases(52.419%), 97cases(8.692%), 384 cases(34.941%) for patients admitted in 2016-2018, versus 385 cases(42.636%), 118 cases(13.068%), 239 cases(27.006%) for patients admitted in 2019-2020, showing significant differences between them ( χ2=19.14,10.05,14.33, P<0.05). (2) Postoperative conditions: the duration of postoperative hospital stay of 2 019 patients was 13 (10) days. One of 2 019 patients lacked the data of postopera-tive complications. The overall postoperative complication rate was 45.292%(914/2 018), of which the incidence rate of grade B or C pancreatic fistula was 23.439%(473/2 018), the rate of grade B or C hemorrhage was 8.127%(164/2 018), the rate of grade B or C delayed gastric emptying was 15.312%(309/2 018), the rate of biliary fistula was 2.428%(49/2 018) and the rate of abdominal infection was 12.884%(260/2 018). The reoperation rate of 2 019 patients was 1.932%(39/2 019), the in-hospital mortality was 0.644%(13/2 019), the postoperative 30-day mortality was 1.238%(25/2 019), and the postoperative 90-day mortality was 2.675%(54/2 019). There were 541 cases(48.477%) with overall postoperative complications, 109 cases(9.767%) with grade B or C hemorr-hage, 208 cases(18.638%) with grade B or C delayed gastric emptying , 172 cases(15.412%) with abdominal infection, 39 cases(3.495%) with postoperative 90-day mortality of 1 116 patients admitted in 2016-2018. The above indicators were 373 cases(41.353%), 55 cases(6.098%), 101 cases(11.197%), 88 cases(9.756%), 15 cases(1.661%) of 902 patients admitted in 2019-2020, respectively. There were significant differences in the above indicators between them( χ2=10.22, 9.00, 21.30, 14.22, 6.45 , P<0.05). The in-hospital mortality occurred to 11 patients(0.986%) of 1 116 patients admitted in 2016-2018 and to 2 cases(0.221%) of 903 patients admitted in 2019-2020, showing a significant difference between them ( P<0.05). (3) Postoperative pathological examinations. Disease area of 2 019 patients reported in postoperative pathological examinations: there were 1 346 cases(66.667%) with lesions in pancreas, including 1 023 cases of carcinoma (76.003%) and 323 cases(23.997%) of benign diseases or low potential malignancy. There were 250 cases(12.382%) with lesions in duodenal papilla, including 225 cases of carcinoma (90.000%) and 25 cases(10.000%) of benign diseases or low potential malignancy. There were 174 cases(8.618%) with lesions in bile duct, including 156 cases of carcinoma (89.655%) and 18 cases(10.345%) of benign diseases or low potential malignancy. There were 140 cases(6.934%) with lesions in ampulla, including 134 cases of carcinoma (95.714%) and 6 cases(4.286%) of benign diseases or low potential malignancy. There were 91 cases(4.507%) with lesions in duodenum, including 52 cases of carcinoma (57.143%) and 39 cases(42.857%) of benign diseases or low potential malignancy. There were 18 cases(0.892%) with carcinoma in other sites. Postoperative pathological examination showed carcinoma in 1 608 cases(79.643%), benign diseases or low potential malignancy in 411 cases(20.357%). The histological types of 1 608 patients with carcinoma included adenocarcinoma in 1 447 cases (89.988%), intra-ductal papillary mucinous carcinoma in 37 cases(2.301%), adenosquamous carcinoma in 35 cases(2.177%), adenocarcinoma with other cancerous components in 29 cases(1.803%), neuroendocrine carcinoma in 18 cases(1.119%), squamous carcinoma in 1 case (0.062%), and other histological malignancies in 41 cases(2.550%). The histological types of 411 patients with benign or low poten-tial malignancy included intraductal papillary mucinous neoplasm in 107 cases (26.034%), chronic or autoimmune inflammatory disease in 62 cases(15.085%), neuroendocrine tumor in 58 cases(14.112%), pancreatic serous cystadenoma in 52 cases(12.652%), pancreatic solid pseudopapillary tumor in 36 cases(8.759%), gastrointestinal stromal tumor in 29 cases(7.056%), villous ductal adenoma in 20 cases(4.866%), pancreatic mucinous cystadenoma in 2 cases(0.487%), pancreatic or duodenal trauma in 2 cases(0.487%) and other histological types in 43 cases(10.462%). (4) Prognosis of patients with periampullary carcinoma. Results of survival analysis of 1 590 patients with main locations of periampullary carcinoma showed that of 1 023 patients with pancreatic cancer, 969 cases were followed up for 3.0-69.6 months, with a median follow-up time of 30.9 months. The median overall survival time, 1-year, 3-year and 5-year survival rates of pancreatic cancer patients were 19.5 months [95% confidence interval ( CI) as 18.0-21.2 months], 74.28%, 29.22% and 17.92%. Of 225 patients with duodenal papillary cancer, 185 cases were followed up for 3.0-68.9 months, with a median follow-up time of 36.7 months. The median overall survival time, 1-year, 3-year and 5-year survival rates were unreached, 94.92%, 78.87% and 66.94%. Of 156 patients with distal bile duct cancer, 110 cases were followed up for 3.0-69.5 months, with a median follow-up time of 25.9 months. The median overall survival time, 1-year, 3-year and 5-year survival rates were 50.6 months (95% CI as 31.4 to not reached), 90.37%, 56.11% and 48.84%. Of 134 patients with ampullary cancer, 100 cases were followed up for 3.0-67.8 months, with a median follow-up time of 28.1 months. The median overall survival time, 1-year, 3-year and 5-year survival rates were 62.4 months (95% CI as 37.8 months to not reached), 90.57%, 64.98% and 62.22%. Of 52 patients with duodenal cancer, 38 cases were followed up for 3.0-69.5 months, with a median follow-up time of 26.2 months. The median overall survival time, 1-year, 3-year and 5-year survival rates were 52.0 months (95% CI as 30.6 months to not reached), 93.75%, 62.24% and 40.01%.There was a significant difference in overall survival after PD between patients with different locations of periampullary malignancies ( χ2=163.76, P<0.05). Conclusions:PD is safe and feasible in a high-volume pancreas center, but the incidence of overall postoperative complications remains high. With the increase of PD volume, the incidence of overall postoperative complications has significantly decreased. There is a significant difference in overall survival time after PD among patients with different locations of periampullary malignancies. The 5-year survival rate after PD for duodenal papillary cancer, ampullary cancer, duodenal cancer and distal bile duct cancer is relatively high, whereas for pancreatic cancer is low.

Objective:To compare surgical methods and clinical efficacy among different types of cesarean scar pregnancy (CSP).Methods:A total of 158 patients with CSP who received treatment in Yuncheng Central Hospital from January 2016 to June 2019 were included in this study. According to Expert Consensus on Diagnosis and Treatment of Cesarean Scar Pregnancy (2016 version), type I CSP was found in 55 patients, type II in 86 patients and type III in 17 patients. These patients were divided into groups A (ultrasound-guided suction curettage), B (uterine artery chemoembolization + ultrasound-guided suction curettage) and C (laparoscopic scar pregnancy lesion resection + scar repair) according to different surgical methods. The amount of intraoperative blood loss, the difference in human chorionic gonadotropin (HCG) level between before and after surgery, the time to postoperative HCG level returning to normal level, menstruation recovery, and re-pregnancy were compared between groups.Results:The amount of intraoperative blood loss in the groups A, B and C was (43.33 ± 72.31) mL, (34.41 ± 17.16) mL, (65.71 ± 70.52) mL, respectively. There was significant difference between groups ( F = 8.51, P = 0.014]. The difference in HCG level between before and after surgery in groups A, B and C was (0.64 ± 0.18), (0.79 ± 0.10), (0.76 ± 0.19), respectively. There was significant difference in the difference in HCG level between groups ( F = 19.21, P < 0.001). There was significant difference in the incidence of postoperative menstrual volume reduction between group B and the other two groups ( χ2 = 6.73, P = 0.003). After surgery, intrauterine pregnancy occurred in 12 patients, including 8 patients in group A (type I CSP in 2 patients, type II CSP in 3 patients, type III CSP in 3 patients), 4 patients in group B (type I CSP in 3 patients, type II CSP in 1 patient). Finally, full-term fetus delivery by cesarean section was performed in 6 patients (4 patients in group A and 2 patients in group B). Conclusion:Uterine artery chemoembolization combined with uterine curettage had less blood loss, during surgery and leads to an obvious decrease in HCG level, but it can result in reduction of menstrual volume. Ultrasound-guided suction curettage is preferred for type I and type II CSP. Balloon compression can be used to stop bleeding if massive bleeding occurs. Laparoscopic scar pregnancy lesion resection plus scar repair is recommended for type III CSP.

Objective:To evaluate the role of spinal Rac1 signaling pathway in the maintenance of bone cancer pain (BCP) in rats.Methods:Sixty-four clean-grade adult female Sprague-Dawley rats, aged 8-10 weeks, weighing 180-200 g, were divided into 4 groups using a random number table method: sham operation group (group S, n=8), BCP group ( n=40), BCP plus normal saline group (group BCP+ Veh, n=8), and BCP plus NSC23766 group (group BCP+ NSC, n=8). BCP was induced by injecting Walker 256 mammary gland cancer cell suspension 5 μl (1×10 5 cells/μl) into the bone marrow of the right tibia of rats in BCP, BCP+ Veh and BCP+ NSC groups, while the equal volume of inactivated tumor cells were injected in group S. On 9-11 days after BCP, specific Rac1 inhibitor NSC23766 (5 μg/5 μl) was intrathecally injected once a day in group BCP+ NSC, and the equal volume of normal saline (5 μl) was given once a day in group BCP+ Veh.The mechanical paw withdrawal threshold (MWT) was measured at 1 day before BCP (T 0) and 3, 5, 7, 14 and 21 days after BCP (T 1-5). Eight rats in each group were sacrificed after measurement of MWT at each time point in BCP group or after the last measurement of MWT in S, BCP+ Veh and BCP+ NSC groups, and the lumbar segment (L 4-6) of the spinal cord was removed for determination of the expression of Rac1 signaling pathway-related proteins Rac1, GTP-Rac1, PAK1 and p-PAK1 using Western blot. Results:Compared with group S, MWT was significantly decreased at T 3-5 in BCP, BCP+ Veh and BCP+ NSC groups, and the expression of GTP-Rac1 and p-PAK1 was up-regulated at T 3-5 in group BCP ( P<0.05). Compared with group BCP+ Veh, MWT was significantly increased at T 4, 5, and the expression of GTP-Rac1 and p-PAK1 was down-regulated in group BCP+ NSC ( P<0.05). Conclusion:Spinal Rac1 signaling pathway is involved in the maintenance of BCP in rats.