Objective To establish a model to predict the cell-cycle process in response to ionizing radiation.Methods Human choroidal malignant melanoma 92-1 cells were used and the cell cycle distribution of cells was analyzed in 0-96 h after exposure to X-rays.A phenomenological model was constructed based on biological knowledge to describe the cell cycle dynamics in experiments.Results In the present study,a phenomenological model was constructed to describe the cellcycle dynamics of synchronized 92-1 cells in responding to various doses of ionizing radiation.The simulation results obtained with the model were consistent with the experimental data,demonstrating that the model had a good expansibility and could be used to predict the dynamics of cell cycle in responding to ionizing radiation.Further theoretical modeling of the cellcycle dynamics was made and the results were consistent with the simulation.Conclusions A phenomenological model was constructed which could be used to describe the dynamics of cell cycle of cells exposed to ionizing radiation and was supported by the experimental data.Because this model is easy to run by the written code,it has a good expansibility for studying the behaviors of cell populations under various conditions.

Objective: To explore the functions of DNA-PKcs in cellular low dose hyper-radiosensitivity. Methods: Colony-formation assay was used to detect the survival fractions of M059K and M059J cell lines treated by X-ray irradiation. Micronucleus assay and γ-H2AX foci assay were used to measure the radiation-induced DNA damage. Western blot was used to detect the relative expression levels of phospho-Chk1, total Chk1, phospho-Chk2 and total Chk2 of M059K and M059J cells. Results: The hyper-radiosensitivity was observed in M059K cells irradiated with X-ray of doses lower than 1 Gy. DNA damage levels did not show HRS/IRR in the cell lines we used. pChk1/Chk1 in M059K cells was significantly increased during 20 min to 60 min after 0.2 Gy X-ray irradiation (t=14.157, 13.661, 14.177, 11.317, 14.512, P<0.05); pChk2/Chk2 in M059K cells was markedly increased during 20 min to 50 min after 0.2 Gy X-ray irradiation (t=13.182, 13.868, 14.155, 14.477, P<0.05). Conclusions M059K cells show the phenomenon of low dose hyper-radiosensitivity, which may be related to activation of proteins in G₂/M phase checkpoints regulated by DNA-PKcs.

BACKGROUNDVarious rat kidney transplantation models have been introduced over the decades and the study on the models seems to lack novelty and necessity. However, vascular anastomosis, especially renal vein, is still very difficult for trainees. The aim of this study was to provide the modified renal venous anastomosis of rat kidney transplantation to substitute the current method for trainees.

METHODSMale Wistar rats were used as donors and recipients, respectively. Left orthotopic transplantation was performed with a modified technique of renal vein anastomosis, combining the end-to-end sutures with epidural catheter. Meanwhile, the survival rate, warm ischemia time, renal venous anastomosis time, and complications were recorded to evaluate the merits of the modified technique compared with the current recommended technique of rat renal vein. Two trainees took part in the learning of the models in two methods for performing 30 operations, respectively.

RESULTSThe difference in warm ischemia time (from (57.25 ± 7.30) minutes in the first 10 operations to (30.05 ± 1.85) minutes in the third 10 operations) and renal vein anastomosis time (from (32.80 ± 3.80) minutes in the first 10 operations to (19.30 ± 0.98) minutes in the third 10 operations) was significantly short (P < 0.01) and the survival rate was statistically high (from (25 ± 7)% in the first 10 operations to 70% in the third 10 operations) in equal number of operations (P < 0.01) by comparing with the current recommended method ((47.60 ± 7.19) minutes to (22.8 ± 1.85) minutes, (22.40 ± 3.10) minutes to (9.95 ± 1.50) minutes, 45%± 7% to 80%± 0, respectively). The intraoperative complications and postoperative complications of renal venous anastomosis were also significantly decreased (P < 0.01).

CONCLUSIONSThe technique with epidural catheter can shorten the learning curve of the trainee learning rat kidney transplantation. It may replace the currently recommended technique of rat renal vein for trainees.

Anastomosis, Surgical ; methods ; Animals ; Kidney Transplantation ; methods ; Male ; Rats ; Rats, Wistar ; Renal Veins

【Objective】 To explore the clinical value of laparoscopic radical cystectomy based on fascia anatomy for bladder cancer treatment. 【Methods】 The clinical data of 51 patients with bladder cancer who underwent 3D laparoscopic radical cystectomy during Jan.2015 and Jun.2022 were retrospectively analyzed.The surgery was performed based on membrane anatomy technology along four longitudinal and two transverse planes to complete the radical cystectomy.The pelvic plexus was preserved for patients with normal preoperative sexual function. 【Results】 All surgeries were completed without conversion to open operation.The mean operation time was (502.52±108.99) min, mean intraoperative blood loss was (275.96±155.18) mL, mean postoperative drainage time was (4.14±2.41) d, and the mean postoperative hospital stay was (16.37±4.85) d.The mean number of lymph nodes removed was (17.98±11.48).The mean postoperative follow-up was (30.27 ±19.39) months.At the last follow-up, no Clavien ≥grade 3 complications were observed.The estimated overall survival (OS), tumor-specific survival (TSS), and recurrence-free survival (RFS) were 82.4%, 92.2%, and 88.2%, respectively.The lymph node positive patients had shorter OS and RFS (60.0%, 60.0%) than the lymph node negative patients (84.8%, 91.3%).Among the 19 male patients who underwent radical cystectomy with pre-exposure and preservation of pelvic plexus, daytime and nocturnal continence rate were 83.3% and 72.2%, respectively, and 17 patients recovered potency within 6 months postoperatively. 【Conclusion】 Laparoscopic radical cystectomy based on fascia anatomy is safe and effective in laparoscopic radical cystectomy, with standardized surgical procedure, satisfactory oncological outcomes, little hemorrhage, few complications and fast recovery.