The aim of this study is to identify the cause of death of a South China tiger cub at the Meihuashan breeding institute of Fujian Province.Pathogenic bacteria were isolated and cultured from liver,spleen,lung and other tissue samples of the dead South China tiger aseptically.The iso-lated bacteria were identified through morphological observation,biochemical characterization,sequence analysis of housekeeping gene gyrB,virulence gene detection,animal pathogenicity test and drug sensitivity test.A pathogenic Aeromonas hydrophila strain,designated FJ/Tiger-201809 was successfully isolated from the trachea of dead South China tiger.The nucleotide sequence ho-mology between the isolate and 11 strains of Aeromonas gyrB ranged from 91.2％to 99.1％,with the highest homology of 99.1％observed with Aeromonas hydrophila(AF208251.1).Genetic evo-lution analysis showed that the isolated strain FJ/Tiger-201809 was in the same evolutionary branch as other reference strains of Aeromonas hydrophila and was closely related.The pathoge-nicity test in mice showed artificial infection of mice with the strain resulted in varying degrees of lesions in several organs of the mice,and the median lethal dose(LD50)was 1 × 107.8 CFU/mL.Virulence gene test results showed that the isolate FJ/Tiger-201809 carried two virulence genes,aer and act.The results of drug sensitivity test showed that FJ/Tiger-201809 was highly sensitive to enrofloxacin and ampicillin among 18 commonly used antibiotics,relatively sensitive to penicil-lin G and doxycycline,and resistant to the other 14 antibiotics.In conclusion,this study isolated and identified a strain of Aeromonas hydrophila from a dead South China tiger with multiple drug resistance and strong pathogenicity,which provided an important reference for the prevention and control of bacterial diseases in South China tiger.

The aim of this study is to identify the cause of death of a South China tiger cub at the Meihuashan breeding institute of Fujian Province.Pathogenic bacteria were isolated and cultured from liver,spleen,lung and other tissue samples of the dead South China tiger aseptically.The iso-lated bacteria were identified through morphological observation,biochemical characterization,sequence analysis of housekeeping gene gyrB,virulence gene detection,animal pathogenicity test and drug sensitivity test.A pathogenic Aeromonas hydrophila strain,designated FJ/Tiger-201809 was successfully isolated from the trachea of dead South China tiger.The nucleotide sequence ho-mology between the isolate and 11 strains of Aeromonas gyrB ranged from 91.2％to 99.1％,with the highest homology of 99.1％observed with Aeromonas hydrophila(AF208251.1).Genetic evo-lution analysis showed that the isolated strain FJ/Tiger-201809 was in the same evolutionary branch as other reference strains of Aeromonas hydrophila and was closely related.The pathoge-nicity test in mice showed artificial infection of mice with the strain resulted in varying degrees of lesions in several organs of the mice,and the median lethal dose(LD50)was 1 × 107.8 CFU/mL.Virulence gene test results showed that the isolate FJ/Tiger-201809 carried two virulence genes,aer and act.The results of drug sensitivity test showed that FJ/Tiger-201809 was highly sensitive to enrofloxacin and ampicillin among 18 commonly used antibiotics,relatively sensitive to penicil-lin G and doxycycline,and resistant to the other 14 antibiotics.In conclusion,this study isolated and identified a strain of Aeromonas hydrophila from a dead South China tiger with multiple drug resistance and strong pathogenicity,which provided an important reference for the prevention and control of bacterial diseases in South China tiger.

There are several special types of tumors in the rectal and anal canal,such as neuroendocrine tumors(NETs),gastrointestinal stromal tumors(GIST),squamous cell anal carcinoma(SCAC),anorectal malignant melanoma(ARMM),and primary rectal lymphoma(PRL).They are rare and have different clinical characteristics from the rectal cancer,resulting in insufficient understanding of them by clinicians.This article reviews the diagnosis and treatment of special types of tumors in the rectal and anal region.

Objective:To investigate the clinical characteristics and prognosis of duodenal neuroendocrine neoplasms.Methods:The clinical data of 35 patients with duodenal neuroendocrine neoplasms admitted to Union Hospital, Tongji Medical College, Huazhong University of Science & Technology from Jan 2012 to Dec 2021 were retrospectively analyzed. The differences of clinical characteristics between periampullary and non-periampullary duodenal neuroendocrine neoplasms were analyzed. Kaplan-Meier curve was used for survival analysis, and the clinical factors affecting the prognosis were analyzed.Results:Of the 35 patients, 30 underwent tumor resection, 7 (23%) developed different degree of complications after operation and were improved and discharged after intervention. A total of 5 patients died during the follow-up period. Only 1 of 30 patients who underwent tumor resection died 30 months after operation due to disease progression, and the others had no recurrence or metastasis. Univariate analysis showed that tumor size, tumor grade, and tumor location were associated with the prognosis of patients (all P<0.05), and multivariate analysis showed that patients with tumors located.Away from the ampulla had a significantly better prognosis than those located around the duodenal ampulla ( P<0.01). Conclusions:Patients with duodenal neuroendocrine neoplasms have a good prognosis after complete resection; patients with duodenal neuroendocrine neoplasms located around the ampulla of Vater have a relatively poor prognosis compared with those away from the area of ampulla.

Objective:To investigate the short-term efficacy of laparoscopic surgery after short-course radiotherapy followed by sequential chemotherapy combined with anti-programmed death-1 (PD-1) antibody therapy for locally advanced rectal cancer.Methods:The prospective study was conducted. The clinicopathological data of 30 locally advanced rectal cancer patients who were admitted to the Union Hospital of Tongji Medical College of Huazhong University of Science and Technology from November 2019 to September 2020 were selected. Patients underwent laparos-copic surgery after short-course radiotherapy followed by sequential chemotherapy combined with anti-PD-1 antibody therapy. Observation indicators: (1) situations of the enrolled patients; (2) situations of short-course radiotherapy followed by sequential chemotherapy combined with anti-PD-1 antibody therapy and adverse events; (3) preoperative evaluation and surgical situations; (4) postoperative situations and pathological examinations; (5) postoperative adjuvant chemo-therapy and follow-up. Follow-up was conducted using outpatient examination and telephone interview up to March 2022. Patients were followed up once every 3 weeks during the period of short-course radiotherapy followed by sequential chemotherapy combined with anti-PD-1 antibody therapy to detect the adverse events and patients were followed up once every 3 months during the first postoperative 2 years and once every 6 months thereafter to detect tumor recurrence and survival of patients. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distribution were represented as M(range). Count data were described as absolute numbers or percentages. The Kaplan-Meier method was used to calculate survival rates and draw survival curves. Results:(1) Situations of the enrolled patients. A total of 30 patients were selected for eligibility. There were 17 males and 13 females, aged (57±16)years. Cases with preoperative primary tumor in stage cT3 and cT4 were 22 and 8, respectively. Cases with preoperative clinical lymph node metastasis in stage cN0, cN1, cN2 were 4, 16, 10, respectively. Cases in preoperative clinical stage Ⅱ and Ⅲ were 4 and 26, respectively. Of the 30 patients, there were 21 cases with positive circumferential margin and 12 cases with vascular invasion in extramural of rectum in the preoperative imaging evaluation. Distance from the distal margin of tumor to anal margin and tumor diameter of the 30 patients were 4.7(range, 1.9?9.0)cm and 5.4(range, 2.1?10.0)cm, respectively. There were 28 cases with mismatch repair proficient and 1 case with mismatch repair deficiency in tumor tissues. There was 1 case missing the data of mismatch repair in tumor tissues as failed in biopsy of pathological examination before the treatment. (2) Situations of short-course radiotherapy followed by sequential chemotherapy combined with anti-PD-1 antibody therapy and adverse events. All the 30 patients completed preoperative short-course radiotherapy successfully. Of the 30 patients, there were 3 cases not undergoing the sequential chemotherapy combined with anti-PD-1 antibody therapy and there were 24 cases undergoing 2 courses of the sequential chemotherapy combined with anti-PD-1 antibody therapy and 3 cases undergoing 1 course of the sequential chemotherapy combined with anti-PD-1 antibody therapy. The time interval between ending of radiotherapy and starting of chemotherapy combined with anti-PD-1 antibody therapy of the 27 patients was 12(range, 4?18) days. Cases with leukopenia, cases with endothelial hyperplasia of skin capillaries, cases with radiation proctitis, cases with anemia, cases with peripheral neurotoxicity, cases with neutropenia, cases with thrombocytopenia, cases with fatigue, cases with anorexia, cases with abnormal liver function, cases with hypothyroidism were 24, 22, 21,20, 18, 16, 16, 13, 10, 9, 2 in the 30 patients during the preoperative short-course radiotherapy followed by sequential chemotherapy combined with anti-PD-1 antibody therapy. Cases with the above adverse events were improved after symptomatic treatment. (3) Preoperative evaluation and surgical situations. Seven of the 30 patients were in clinical complete remission after preoperative multidisciplinary evaluation and the other 23 patients were not in clinical complete remission. Twenty-seven of the 30 patients underwent laparoscopic radical resection of rectal cancer and 3 patients not undergoing the sequential chemotherapy combined with anti-PD-1 antibody therapy did not undergo surgery. The time interval between ending of chemotherapy combined with anti-PD-1 antibody therapy and the surgery of the 27 patients were 14(range, 5?141)days. Of the 27 cases, there were 13 cases and 14 cases with 0 and 1 of the preoperative Eastern Cooperative Oncology Group score, respectively, and there were 24 cases undergoing low anterior proctectomy and 3 cases undergoing abdominoperineal excision. The operation time and volume of intra-operative blood loss of the 27 cases were (182±36)minutes and 30(range, 10?150)mL, respectively. Of the 27 cases, there were 16 cases with protective ileostomy and 24 cases with anal preservation. (4) Postoperative situations and pathological examinations. The time to postoperative first flatus, time to postoperative initial liquid food intake and duration of postoperative hospital stay of the 27 patients undergoing surgery were 2(range, 1?4)days, 3(range, 2?5)days and 8(range, 7?16)days, respectively. Five of the 27 patients had postoperative grade Ⅰ?Ⅱ complications, including 2 cases with incision infection, 1 case with abdominal infection, 1 case with incision hemorrhage and 1 case with venous thrombosis in left lower limb intermuscular. Cases with postoperative complica-tions were improved after symptomatic treatment. Results of postoperative pathological examina-tion showed that the rate of pathologic complete response in 27 patients was 48.1%(13/27). Of the 27 cases, cases in grade 0, grade 1, grade 2, grade 3 of the tumor regression grading were 13, 5, 7, 2, respectively, cases in stage T0, stage Tis, stage T2, stage T3 of the tumor T staging were 13, 1, 5, 8, respectively, cases in stage N0, stage N1, stage N2 of the tumor N staging were 19, 6, 2, respectively, cases in stage 0, stage Ⅰ, stage Ⅱ, stage Ⅲ of the tumor TNM staging were 14, 0, 5, 8, respectively. The number of lymph node dissected of the 27 patients was 15(range, 3?29). Of the 27 patients, there was 1 case with positive circumferential margin and 26 cases achieving R 0 resection. None of the 27 patients underwent secondary operation or perioperative death. (5) Postoperative adjuvant chemotherapy and follow-up. Of the 27 patients undergoing surgery, 21 cases underwent post-operative adjuvant chemotherapy, with the cycles of 4(range, 1?6). All the 27 patients were followed up for 20(range, 20?29)months. During the follow-up, 3 cases not achieving pathological complete response had tumor recurrence and no patient died. The disease free survival rate of the 27 patients was 88.9%. Conclusion:Laparoscopic surgery after short-course radiotherapy followed by sequential chemotherapy combined with immunotherapy for locally advanced rectal cancer is safe and feasible, with satisfied short-term efficacy.

Objective:To identify the clinical factors associated with pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) in locally advanced middle and low rectal cancer and establish a scoring system.Methods:In this retrospective analysis the clinical data of patients with locally advanced middle and low rectal cancer treated with nCRT combined with surgery at Union Hospital of Tongji Medical College, Huazhong University of Science and Technology from Jan 2016 to Jan 2020 were studied. Patients were divided into pCR group and non-pCR group. Single factor analysis and Logistic multivariate regression analysis were performed to explore pCR related factors after nCRT, and a pCR prediction scoring system was established.Results:The pCR was achieved in 33 patients (20.8%). Univariate analysis showed that the maximum thickness of the tumor≤25mm before nCRT ( P=0.046), concurrent oxaliplatin-combined intensive chemotherapy ( P=0.013), the NLR≤1.65 before nCRT ( P=0.004) and the serum CEA≤5 ng/ml before nCRT ( P=0.016) were significantly associated with pCR. In multivariate analysis, concurrent oxaliplatin-combined intensive chemotherapy, the NLR before nCRT and serum CEA before nCRT were independent related factors of pCR. The probability of pCR for patients with score of 0, 1, 2, and 3 was 42% (10/24), 30% (19/63), 5% (3/57) and 7% (1/15), respectively. The probability of pCR in patients with score≤1 point was 33% (29/87), and 6% (4/72) for score?1 point ( P?0.001). The area under the curve of the scoring system is 0.729 (95% CI: 0.638-0.820, P?0.001). Conclusions:Concurrent oxaliplatin-combined intensive chemotherapy, NLR≤1.65 before nCRT and serum CEA≤5 ng/ml before nCRT are independent predictors of pCR in locally advanced middle and low rectal cancer and the scoring system constructed in combination with above indicators can effectively predict pCR.

Objective:To explore the clinical features, diagnosis, treatment and prognosis of rectal neuroendocrine tumor with lymphatic metastasis.Method:There were 153 case who were diagnosed with RNET, among them, there were 10 patients(6.5%) with lymphatic metastasis in Affiliated Union Hospital, Tongji Medical College, Huazhong University of Science & Technology from January 2012 to December 2020, including 4 males and 6 females, aged from 32 to 71 years old, and the median age was 56.5 years.Results:Of the 10 patients, 3 had tumors < 1 cm in diameter, 4 had 1 to 2 cm, and 3 had > 2 cm. Preoperative CT examination was performed in 10 patients, of which 9 suggested lymphatic metastasis; preoperative MRI examination was performed in 7 patients, of which 6 suggested lymphatic metastasis. All patients were received radical resection, in which Miles operation was performed in 2 cases, Dixon operation in 6 cases, and additional Dixon operation after endoscopic submucosal dissection in 2 cases.All patients were followed up for 51 months (ranged from 14 to 118 months). Nine patients had no recurrence or metastasis, and one patient had abdominal metastasis 40 months after surgery and died after 31 months of comprehensive treatment.Conclusions:Lymphatic metastasis is rare in rectal neuroendocrine tumor. Imaging examination has important reference value for judging the status of lymphatic metastasis. For rectal neuroendocrine tumor with lymphatic metastasis, radical resection is effective.

Objective:To investigate the clinicopathological characteristics of primary gastrointestinal stromal tumors (GIST) with PDGFRα mutation and analyze the prognosis of different subtypes.Methods:From Jun 2010 to Jun 2019, the clinicopathological data of 35 patients with primary PDGFRα mutation GIST, who underwent surgical therapy in the Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, were analyzed retrospectively.Results:The main symptoms was abdominal pain (28 cases, 80%), followed by abdominal mass (6 cases, 17%), and hemafecia (1 case, 3%). 31 primary lesions (89%) were located in the stomach and 4 (11%) in other than stomach. 13 cases (37%) were of epithelioid cells, 14 cases (40%) were of spindle cells and 8 cases (23%) were of mixed cells. 27 cases (77%) were CD117 positive , 28 cases (80%) CD34 positive , and 30 cases (86%) were DOG-1 positive. 19 cases (54%) had D842V mutation and 16 cases (46%) had non-D842V mutation. Complete surgical resection was performed in all patients, with no perioperative death. The 3-year recurrence-free survival rate of the D842V mutation group was lower than that of the non-D842V mutation group (84% vs. 100%, P=0.045). Conclusions:The mutation rate of PDGFRα gene was low, mostly derived from the stomach. PDGFRα mutation GIST presents inert biological behavior and the overall prognosis was good.

Objective:At present, the modified NIH classification commonly used in clinical practice is still insufficient for assessing the risk of postoperative recurrence in some patients with intermediate-high risk gastrointestinal stromal tumors (GIST). Through exploring risk factors for recurrence of intermediate-high risk GIST, this study establishes a predictive model for recurrence with more convenience and more precision in order to guide adjuvant therapy for intermediate-high risk GIST patients.Methods:A retrospective case-control study was carried out. Clinical and pathological data of 432 GIST patients who did not receive preoperative targeted treatment, underwent complete resection in the Union Hospital of Tongji Medical College of Huazhong University of Science and Technology from January 2005 to June 2018, and were diagnosed as intermediate- or high-risk based on modified NIH classification by postopertive pathology, were retrospectively analyzed. Cox regression model was used to idenitify independent risk factors of recurrence, and a recurrence risk scoring model was established. The receiver operating characteristic curve (ROC curve), consistency index (C-index) and calibration curve were used to evaluate the accuracy of the scoring model in predicting the recurrence of moderate-risk and high-risk GIST patients.Results:Among 432 GIST patients, 332 were diagnosed as high-risk and 100 as moderate-risk; 237 were males and 195 females with average age of (57.4±12.4) years. Of 432 patients, 211 cases (48.8%) had fibrinogen (FIB) >3.5 g/L; 85 cases (19.7%) had platelet to lymphocyte ratio (PLR)>272.5; 122 cases (28.2%) had neutrophil to lymphocyte ratio (NLR) > 4.2; 102 cases (23.6%) had systemic inflammatory reaction index (SIRI)> 2.7; 198 cases (45.8%) had tumor long diameter >8 cm and 108 cases (25.0%) had mitotic counts > 8/50 HPF. Cox multivariable analysis showed that FIB (HR=1.789, 95% CI: 1.058-3.027, P=0.030), PLR (HR=1.862, 95% CI: 1.067-3.249, P=0.029), SIRI (HR=1.790, 95% CI: 1.039-3.084, P=0.036), tumor long diameter (HR=1.970, 95% CI: 1.105-2.925, P=0.017) and mitotic counts (HR=2.187, 95% CI:1.211-3.950, P=0.009) were independent risk factors for recurrence in patients with middle-risk and high-risk GIST. These 5 factors were included in the risk scoring model, which was given a weight score of 58 points, 62 points, 58 points, 63 points, and 78 points, respectively. Patients with a total score of ≤ 78 points were classified as moderate-risk recurrence (group I), those of 78 to 136 points as high-risk recurrence (group II) and those of >136 points as very high-risk recurrence (group III). ROC curve showed that the area under the curve (AUC) of the scoring model was 0.730 and the C-index was 0.724 (95% CI:0.687-0.787). The calibration curves and the Kaplan-Meier curves of patients in the three groups revealed that this model had a good predictive accuracy. Conclusions:For intermediate-risk and high-risk GIST patients, the preoperative FIB >3.5 g/L, PLR > 272.5 and SIRI > 2.7 are independent risk factors of recurrence after surgery. The recurrence risk scoring model established by combining tumor long diameter, mitotic counts, FIB, PLR and SIRI can effectively predict the risk of postoperative recurrence and metastasis in moderate-risk and high-risk GIST patients.

Objective:At present, the modified NIH classification commonly used in clinical practice is still insufficient for assessing the risk of postoperative recurrence in some patients with intermediate-high risk gastrointestinal stromal tumors (GIST). Through exploring risk factors for recurrence of intermediate-high risk GIST, this study establishes a predictive model for recurrence with more convenience and more precision in order to guide adjuvant therapy for intermediate-high risk GIST patients.Methods:A retrospective case-control study was carried out. Clinical and pathological data of 432 GIST patients who did not receive preoperative targeted treatment, underwent complete resection in the Union Hospital of Tongji Medical College of Huazhong University of Science and Technology from January 2005 to June 2018, and were diagnosed as intermediate- or high-risk based on modified NIH classification by postopertive pathology, were retrospectively analyzed. Cox regression model was used to idenitify independent risk factors of recurrence, and a recurrence risk scoring model was established. The receiver operating characteristic curve (ROC curve), consistency index (C-index) and calibration curve were used to evaluate the accuracy of the scoring model in predicting the recurrence of moderate-risk and high-risk GIST patients.Results:Among 432 GIST patients, 332 were diagnosed as high-risk and 100 as moderate-risk; 237 were males and 195 females with average age of (57.4±12.4) years. Of 432 patients, 211 cases (48.8%) had fibrinogen (FIB) >3.5 g/L; 85 cases (19.7%) had platelet to lymphocyte ratio (PLR)>272.5; 122 cases (28.2%) had neutrophil to lymphocyte ratio (NLR) > 4.2; 102 cases (23.6%) had systemic inflammatory reaction index (SIRI)> 2.7; 198 cases (45.8%) had tumor long diameter >8 cm and 108 cases (25.0%) had mitotic counts > 8/50 HPF. Cox multivariable analysis showed that FIB (HR=1.789, 95% CI: 1.058-3.027, P=0.030), PLR (HR=1.862, 95% CI: 1.067-3.249, P=0.029), SIRI (HR=1.790, 95% CI: 1.039-3.084, P=0.036), tumor long diameter (HR=1.970, 95% CI: 1.105-2.925, P=0.017) and mitotic counts (HR=2.187, 95% CI:1.211-3.950, P=0.009) were independent risk factors for recurrence in patients with middle-risk and high-risk GIST. These 5 factors were included in the risk scoring model, which was given a weight score of 58 points, 62 points, 58 points, 63 points, and 78 points, respectively. Patients with a total score of ≤ 78 points were classified as moderate-risk recurrence (group I), those of 78 to 136 points as high-risk recurrence (group II) and those of >136 points as very high-risk recurrence (group III). ROC curve showed that the area under the curve (AUC) of the scoring model was 0.730 and the C-index was 0.724 (95% CI:0.687-0.787). The calibration curves and the Kaplan-Meier curves of patients in the three groups revealed that this model had a good predictive accuracy. Conclusions:For intermediate-risk and high-risk GIST patients, the preoperative FIB >3.5 g/L, PLR > 272.5 and SIRI > 2.7 are independent risk factors of recurrence after surgery. The recurrence risk scoring model established by combining tumor long diameter, mitotic counts, FIB, PLR and SIRI can effectively predict the risk of postoperative recurrence and metastasis in moderate-risk and high-risk GIST patients.