Objective To explore the risk factors for recurrent （≥ 2 times） pneumonia in elderlykidney transplant recipients after surgery. Methods Retrospective analysis was performed from the clinical data of 119 elderly kidney transplant recipients who underwent kidney transplantation at the Eighth Medical Center of the People's Liberation Army General Hospital from January 2010 to January 2024. According to whether pneumonia occurs repeatedly （≥ 2 times） after kidney transplantation， elderly recipients were divided into two groups， with 11 cases in the recurrent pneumonia group and 108 cases in the non-recurrent pneumonia group. Relevant clinical data were compared between the two groups， including the general basic information of the recipient （gender， age， height， weight， smoking history，etc.）， as well as the relevant clinical data （the time of dialysis before kidney transplantation， the maintenance treatment plan of immunosuppressant after surgery， whether there was delayed recovery of kidney function after transplantation， whether there was a decrease in white blood cells after transplantation， serum creatinine level at discharge， whether there was diabetes before and after surgery， and whether there was viral hepatitis B infection， etc.）. We conducted univariate analysis and multivariate logistic regression analysis to explore the risk factors for recurrent pneumonia in elderly kidneytransplant recipients after surgery. Results The incidence of recurrent pneumonia in elderly kidney transplant recipientsafter surgery was 9.24% （11/119）， and one patient in the case group died from severe pneumonia， with a mortality rate of 9.1% （1/11）. Smoking history （OR ＝ 13.15，95% CI ＝ 2.406 ～ 71.91，P ＝ 0.003） and postoperative leukopenia （OR ＝ 6.050，95% CI ＝ 1.248 ～ 29.32，P ＝ 0.025） were risk factors for recurrent pneumonia in elderly kidney transplant recipients. Conclusion Smoking history and postoperative leukopenia increase the risk of recurrent pneumonia in elderly kidney transplant recipients. So we should strengthen postoperative health education for elderly kidney transplant recipients， encourage smoking cessation， and prevent and treat postoperative leukopenia. 

Objective Establish model of abdominal heterotopic heart transplantation in mice and summarize the experience to provide animal model support for further study of organ transplantation immunology. Methods Inbred BALB/c（n ＝ 30）and C57BL/6（n ＝ 30）mice were selected as donors，and inbred BALB/c（n ＝ 60）mice were used as recipients. The ascending aorta of the donor was anastomosed to the abdominal aorta of the recipient，and the pulmonary artery of the donor was anastomosed to the inferior vena cava of the recipient respectively to establish the heterotopic heart transplantation model. The survival time and the rejection of grafts were observed postoperatively. Results The successful rate of transplantation was 85%（51/60）. The donoroperation time was（7.0±1.0）min，and the recipient operation time was（60±10）min. The vascular anastomosis time was（25±3.0）min. After the transplantation，no immunosuppressive agent was used，and the survival time of the graft was（7.6±0.9）d. The graft on the fifth day，the seventh day showed typical rejection by histopathology. Conclusion Skilled microsurgical techniques and timely management of surgical complications are key to the successful establishment of abdominal heterotopic heart transplantation in mice. 

Objective Post-renal transplantation anemia（PTA）occurs frequently in kidney transplant recipients，significantly impacting their quality of life and graft loss. Currently，effective methods to predictthe risk of persistent PTA early post-transplantation are lacking. This study aimed to develop a nomogram prediction model for early persistent PTA specifically tailored to kidney transplant recipients. Methods Using the electronic medical record system of Southern Hospital of Southern Medical University，patient data from January 1，2020 to December 31，2022 were obtained，and 245 subjects were ultimately selected as the research subjects. Among these，85% were randomly selected as the training set for model development，and the remaining 15% constituted the testing set. Using the Least Absolute Shrinkage and Selection Operator（Lasso）regression model，variables potentially affecting early persistent PTA were screened to identify predictive factors.A logistic regression analysis was employed to establish the prediction model. Model performance was assessed using Receiver operating characteristic（ROC）curves，area under the curve（AUC），Calibration plots，and decision Curve Analysis（DCA）. Results Identified predictive factors after screening included recipient's preoperative body mass index，preoperative serum albumin level，preoperative hemoglobin level，preoperative mean corpuscular volume，perioperative use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers，exogenous iron supplementation，and exogenous erythropoietin supplementation. The model demonstrated good discriminativeability with an AUC of 0.87 for the training set and 0.75 for the testing set，indicating robust predictive performance. Calibration and DCA further confirmed the accuracy and clinical utility of the model. Conclusion This nomogram prediction model utilizes early recipient information，including demographic characteristics，laboratory data，and medication regimens，to accurately predict individualized risk of early persistent PTA in kidney transplant recipients. This provides a basis for early clinical intervention，potentially improving patient prognosis and quality of life.