Objective To construct a dynamic prediction model for JC polyomavirus (JCV) reactivation after kidney transplantation. Methods A retrospective analysis was conducted on the clinical data of 128 recipients who met the inclusion criteria and received kidney transplantation in Nanfang Hospital, Southern Medical University, from June 2021 to December 2024. Dynamic Cox regression and dynamic restricted mean survival time (RMST) regression based on the landmark method were adopted to establish the dynamic prediction models, and Monte Carlo cross-validation was used to evaluate model performance. Results The dynamic models could predict the incidence and onset time of JCV reactivation within the subsequent 3 months according to covariates at each landmark time point from the 1st to the 6th month after transplantation. Remuzzi score, body mass index and warm ischemia time were independent risk factors for JCV reactivation, while a history of urinary BK polyomavirus reactivation served as a protective factor. The median values of the area under the curve, C-index and Brier score of the dynamic Cox model were 0.873, 0.851 and 0.065 respectively, and the C-index of the dynamic RMST model was 0.829, all of which were superior to those of the static model. Conclusions The landmark-based dynamic models exhibit excellent predictive performance, which may integrate baseline data and post-transplant follow-up information to realize dynamic assessment of the risk and time window of JCV reactivation, thereby providing evidence for optimizing post-operative monitoring and individualized intervention strategies.

Objective To explore the clinical and imaging features of phosphaturic mesenchymal tumor(PMT).Methods The clinical presentations,laboratory examinations,and imaging manifestations of seven patients with PMT diagnosed by surgery and pathology were analyzed retrospectively.Results Among the 7 patients,four patients had clinical presentations of long-term fatigue and bone pain.All patients showed preoperative blood phosphorus reduction in varying degrees.X-ray examination showed systemic osteomalacia and osteoporosis,accompanied by multiple pathological fractures.On CT,the primary tumor appeared as a soft tissue density mass or a ground glass high-density nodule with irregular calcification and local bone destruction.MRI showed long T1,long T2 signal intensity,and irregular low signal foci were scattered in the T2WI fat-suppressed sequence.The enhanced scans showed moderate to significant inhomogeneous enhancement.One patient who underwent 18F-FDG PET/CT and two patients who underwent 18F-ALF-NOTA-Octreotide(18F-OC)PET/CT examinations showed varying degrees of radioactive concentration in the lesions.Conclusion The clinical presentations and laboratory examinations of patients with PMT have certain characteristics.Systemic osteomalacia with pseudofracture line,calcification matrix within the tumor,and significant inhomogeneous enhancement of the lesion are the key imaging features for diagnosing PMT.18F-OC PET/CT examination plays a crucial role in the systemic localization diagnosis of tumors.

Objective To propose SHA.LIN nephrolithometry scoring system for assessing and predicting the stone-free rate of percutaneous nephrolithotomy ( PCNL) and to investigate the clinical value of SHA.LIN scoring system for nephrolithiasis in patients undergoing PCNL .Methods A literature review from 1976 to 2014 was performed to identify clinically relevant and reproducible variables that could affect the outcomes of PCNL. Six reproducible variables available from preoperative noncontrast-enhanced computed tomography were measured , including stone size ( S) , hydronephrosis ( H) , anatomic distribution (A), length of tract(L), indicator of CT(I), number of involved calices(N) and was named as SHA.LIN nephrolithometry scoring system .A retrospective analysis was conducted of clinical data of 116 patients with nephrolithiasis undergoing PCNL from June 2011 to March 2015. The general conditions , preoperative information , stone characteristics and perioperative variables were collected . The correlation of nephrolithometry scores based on SHA.LIN scoring system with stone-free status, operation time, blood loss, length of hospital stay and postoperative complications were analyzed . Receiver operating characteristic ( ROC) curves was drawn to detect sensitivity and specificity of SHA .LIN score in predicting the stone-free rates of PCNL.Results The SHA.LIN score was 9.13 ±2.24 in this cohort.The stone free rate was 75.9%(88/116).Postoperative complications occurred in 32 (27.6%) cases.In those patients with stone
free, the SHA.LIN score was 8.27 ±1.62, significantly lower than that in those patients with residual stones 11.86 ±1.72 ( t =-10.069, P=0.000) .The SHA.LIN score showed significant correlation with the postoperative stone free status, operation time, estimated blood loss (P<0.01).But, it did not correlate with postoperative complications and length of hospital stay (P>0.05).The area under curve of ROC curves for the SHA.LIN scoring system was 0.923 ( 95%CI 0.870 -0.975 ) . Conclusions The SHA.LIN nephrolithometry scoring system can predict postoperative stone-free status of PCNL and can be used for disease related assessment.Further research is required to evaluate its performance in predicting peri-operative variables and postoperative complications .