Objective:To investigate the safety and therapeutic effect of split liver transplantation (SLT) in clinical application.Methods:This is a retrospective case-series study. The clinical data of 203 consecutive SLT, 79 living donor liver transplantation (LDLT) and 1 298 whole liver transplantation (WLT) performed at the Third Affiliated Hospital of Sun Yat-sen University from July 2014 to July 2023 were retrospectively analyzed. Two hundred and three SLT liver grafts were obtained from 109 donors. One hundred and twenty-seven grafts were generated by in vitro splitting and 76 grafts were generated by in vivo splitting. There were 90 adult recipients and 113 pediatric recipients. According to time, SLT patients were divided into two groups: the early SLT group (40 cases, from July 2014 to December 2017) and the mature SLT technology group (163 cases, from January 2018 to July 2023). The survival of each group was analyzed and the main factors affecting the survival rate of SLT were analyzed. The Kaplan-Meier method and Log-rank test were used for survival analysis.Results:The cumulative survival rates at 1-, 3-, and 5-year were 74.58%, 71.47%, and 71.47% in the early SLT group, and 88.03%, 87.23%, and 87.23% in the mature SLT group, respectively. Survival rates in the mature SLT group were significantly higher than those in the early SLT group ( χ2=5.560, P=0.018). The cumulative survival rates at 1-, 3- and 5-year were 93.41%, 93.41%, 89.95% in the LDLT group and 87.38%, 81.98%, 77.04% in the WLT group, respectively. There was no significant difference among the mature SLT group, the LDLT group and the WLT group ( χ2=4.016, P=0.134). Abdominal hemorrhage, infection, primary liver graft nonfunction,and portal vein thrombosis were the main causes of early postoperative death. Conclusion:SLT can achieve results comparable to those of WLT and LDLT in mature technology liver transplant centers, but it needs to go through a certain time learning curve.

Objective:To investigate the safety and therapeutic effect of split liver transplantation (SLT) in clinical application.Methods:This is a retrospective case-series study. The clinical data of 203 consecutive SLT, 79 living donor liver transplantation (LDLT) and 1 298 whole liver transplantation (WLT) performed at the Third Affiliated Hospital of Sun Yat-sen University from July 2014 to July 2023 were retrospectively analyzed. Two hundred and three SLT liver grafts were obtained from 109 donors. One hundred and twenty-seven grafts were generated by in vitro splitting and 76 grafts were generated by in vivo splitting. There were 90 adult recipients and 113 pediatric recipients. According to time, SLT patients were divided into two groups: the early SLT group (40 cases, from July 2014 to December 2017) and the mature SLT technology group (163 cases, from January 2018 to July 2023). The survival of each group was analyzed and the main factors affecting the survival rate of SLT were analyzed. The Kaplan-Meier method and Log-rank test were used for survival analysis.Results:The cumulative survival rates at 1-, 3-, and 5-year were 74.58%, 71.47%, and 71.47% in the early SLT group, and 88.03%, 87.23%, and 87.23% in the mature SLT group, respectively. Survival rates in the mature SLT group were significantly higher than those in the early SLT group ( χ2=5.560, P=0.018). The cumulative survival rates at 1-, 3- and 5-year were 93.41%, 93.41%, 89.95% in the LDLT group and 87.38%, 81.98%, 77.04% in the WLT group, respectively. There was no significant difference among the mature SLT group, the LDLT group and the WLT group ( χ2=4.016, P=0.134). Abdominal hemorrhage, infection, primary liver graft nonfunction,and portal vein thrombosis were the main causes of early postoperative death. Conclusion:SLT can achieve results comparable to those of WLT and LDLT in mature technology liver transplant centers, but it needs to go through a certain time learning curve.

【Objective】 To construct the secretory expression system of insect cells to express the secretory TSHR A subunit protein in the ovarian cells of Spotoma oryzae (sf9). 【Methods】 A recombinant plasmid containing the target protein was constructed, and then the positive bacmid was screened out by the blue and white spots experiment. The verified bacmid was transfected into SF9 insect cells to obtain recombinant baculovirus. The virus was amplified, and the titer level was detected by virus plaque assay. Finally, Western blotting was used to identify the expression of the recombinant protein and optimize the expression conditions. 【Results】 During the construction of the protein expression system, PCR identification and sequencing results confirmed the correctness of the sequences of the recombinant plasmid and the recombinant bacmid. After the transfection of the bacmid, the signs of virus budding were observed in sf9 cells. The virus was collected and amplified. The titer of P1 generation virus was 2×10⁷ pfu/m according to the plaque assay. The recombinant protein was identified by Western blotting and confirmed to be exogenous into the culture medium. The optimal condition for virus infection and protein expression was 72 h after the infection when the multiplicity of infection (MOI) was 1. 【Conclusion】 We constructed an insect cell expression system secreting TSHR 22-289 (55 ku), and the protein could be successfully glycolyzed. This system provides a preliminary basis for the construction and production of its industrial platform and also provides a useful tool for studies on TSHR protein and prevention of GO in the future.

Objective To investigate the anatomical classification of left intrahepatic bile duct (LHD) and the pattern of bile duct reconstruction during pediatric split liver transplantation and their relationship with postoperative biliary complications. Methods Clinical data of 75 pediatric recipients undergoing split liver transplantation were analyzed retrospectively. Before splitting the donor liver, iopromide injection was used for retrograde cholangiography through the common bile duct. According to the patterns of intrahepatic bile ducts in the second, third and fourth segments, the anatomical classification of LHD of the donor liver was determined. The biliary reconstruction regimens for different classification types of LHD were summarized. The incidence and treatment of biliary complications after pediatric split liver transplantation were analyzed. Results Among 75 donor livers, the anatomical classification of LHD included 57 cases (76%) of type Ⅰ, 9 cases (12%) of type Ⅱ, 4 cases (5%) of type Ⅲ and 5 cases (7%) of type Ⅳ LHD, respectively. Among 75 pediatric recipients, 69 cases (53 cases of type Ⅰ, 8 type Ⅱ, 4 type Ⅲ and 4 type Ⅳ) underwent the left hepatic duct-jejunum Roux-en-Y anastomosis, 1 case received common bile duct-jejunum Roux-en-Y anastomosis (type Ⅳ), and 5 cases underwent the left hepatic duct-common bile duct end-to-end anastomosis (4 cases of type Ⅰ and 1 type Ⅱ). Postoperative biliary complications occurred in 6 cases (8%), including 3 cases of biliary anastomotic stenosis, 2 cases of biliary anastomotic leakage and 1 case of bile leakage on the hepatic resection surface. Among 6 recipients, 4 cases were classified as type Ⅰ and 2 cases of type Ⅲ LHD. No significant difference was observed in the incidence of biliary complications between typical type and anatomical variant type of LHD (all P > 0.05). Among 3 recipients with biliary anastomotic stenosis, 2 cases underwent percutaneous transhepatic cholangial and drainage (PTCD) and 1 case repeatedly received biliary-intestinal anastomosis. Two cases of biliary anastomotic leakage underwent PTCD and 1 case of bile leakage on the hepatic resection surface received local drainage. All 6 children survived after treatment. Conclusions Anatomical variation of LHD can be observed in 24% of donor livers, and type Ⅱ accounts for the highest proportion of 12%. Prior to donor liver splitting, routine cholangiography and fine biliary anastomosis may effectively lower the incidence of biliary complications. The incidence of postoperative biliary complications is not significantly associated with the anatomical classification of LHD.

Objective:To solve the problems in intensity-modulated radiation therapy (IMRT) planning, such as large labor cost and high dependence on the experience of physicists and great inconsistency in the quality of plan, and to discuss an unsupervised automatic treatment planning procedure of IMRT.Methods:The eclipse scripting application programming interface (ESAPI) within the Eclipse treatment planning system (TPS) 15.6 and optimization parameters tree search algorithm (OPTSA) were used to emulate and realize the whole planning process. Interacted with the TPS through ESAPI, relevant dosimetric parameters were input and output. The OPTSA evaluated the plan qualities based on dosimetric parameters of the targets and organs at risk (OARs) and iteratively adjusted the optimization objective parameters to achieve a progressively improving IMRT plan. In order to verify the effectiveness of the automatic planning, twenty historical rectum cancer cases were selected from the clinical database, and the dose distribution and specific dosimetric parameters were compared between the plans generated by the OPTSA and the manual plans under the same constraints.Results:All the auto plans have met clinical requirements. Furthermore, 90% and 10% of the auto plans were deemed as clinically improved and equally compared with the manual plans, respectively. The average CI for the PTV was 0.88 and 0.80 for the auto and manual plans respectively. Compared with the manual plans, the mean doses of all the OARs in the auto plans were reduced by 11% in average. The average elapsed time of automatic planning and manual planning was (28.15±3.61) and (36.7±4.6) min, respectively.Conclusions:The plans created by the proposed algorithm have been shown to be at least as good as the manual plans. In addition, this method can shorten the labor time in plan designing while ensuring the plan quality and consistency of the plan.

Objective:To investigate the performance of W2 plastic scintillator in megavolt photon and electron beams.Methods:The photon and electron beam energy provided by linear accelerator was used to collect data of the W2 scintillator. The parameters include the electrometer reading stability, W2 dose and dose rate linearity, and angular response. And the dose uncertainty of the W2 correction factors was also investigated.Results:The standard deviation of the electrometer reading stability was between 0.03 and 0.47. The linear regression factors of W2 dose were all 1.0; the maximum deviation of the dose rates was 0.61%. The Cerenkov light radiation correction factor(CLR) for 6 and 10 MV were 0.741 and 0.746, respectively, and the CLR for 6, 9, 12 and 15 MeV were 0.750, 0.753, 0.757 and 0.757, respectively. The maximum deviation of dose uncertainty for 15 MeV was 3.15%.Conclusions:The signal obtained by the blue and green channel was no angular dependence, the same as the high-energy electron beam, which verified that the Cerenkov radiation correction factor has good linearity. W2 plastic scintillator can be applied to non-coplanar radiotherapy dosimetry.

Objective:To assess the three-dimensional dose distribution in radiotherapy plans using the structural similarity index(SSIM), compare the performance of SSIM with commonly used quality assessment indices, and develop a SSIM-based quality assessment method of multiple prescribed doses.Methods:The SSIM was introduced to providea quality score of various voxels by comparing actual and ideal three-dimensional dose data and combining the spatial location information of the voxels. Then the average value in a region of interest (ROI) was calculated as the quality score of the region. Fifty-three cases of cervical cancer were selected to analyze the correlation of the SSIM with the uniformity index (HI), conformity index (CI) of the dose distribution in various ROIs and to explore the capability of the SSIM to reflect the uniformity and conformity of dose distribution.Two types of quality defects were individually introduced into two of 53 radiotherapy plans. Then the two plans were compared with normal plans to characterize the response of the SSIM.Results:There was no correlation between HI and SSIM in positive lymph nodes(PGTVnd) due to the decrease in the HI sensitivity, while there was a significant negative correlation between them in regions where PGTVnd was removed from the planning target volume(PTV, R=-0.86, P<0.01). Meanwhile, there was a significant positive correlation between CI and SSIM in PGTVnd ( R=0.83, P<0.01). Therefore, the SSIM can be used to identify the artificial design defects in plans by determining abnormal dose gradients. Conclusions:Apart from reducing the defects of previous assessment parameters, the SSIM has the capability to assess the quality of radiotherapy plans by combining the uniformity and conformity of dose distribution and can provide accurate feedback on the spatial locations of quality defects.

Objective:To develope an automatic volumetric modulated arc therapy (VMAT) planning for rectal cancer based on a dose-prediction model for organs at risk(OARs) and an iterative optimization algorithm for objective parameter optimization.Methods:Totally 165 VMAT plans of rectal cancer patients treated in Peking University Cancer Hospital & Institute from June 2018 to January 2021 were selected to establish automatic VMAT planning. Among them, 145 cases were used for training the deep-learning model and 20 for evaluating the feasibility of the model by comparing the automatic planning with manual plans. The deep learning model was used to predict the essential dose-volume histogram (DVH) index as initial objective parameters(IOPs) and the iterative optimization algorithm can automatically modify the objective parameters according to the result of protocol-based automatic iterative optimization(PBAIO). With the predicted IOPs, the automatic planning model based on the iterative optimization algorithm was achieved using a program mable interface.Results:The IOPs of OARs of 20 cases were effectively predicted using the deep learning model, with no significantly statistical difference in the conformity index(CI) for planning target volume(PTV)and planning gross tumor volume(PGTV)between automatic and manual plans( P>0.05). The homogeneity index (HI) of PGTV in automatic and manual plans was 0.06 and 0.05, respectively( t=-6.92, P< 0.05). Compared with manual plans, the automatic plans significantly decreased the V30 for urinary bladder by 2.7% and decreased the V20 for femoral head sand auxiliary structure(avoidance)by 8.37% and 15.95%, respectively ( t=5.65, 11.24, P< 0.05). Meanwhile, the average doses to bladder, femoral heads, and avoidance decreased by 1.91, 4.01, and 3.88 Gy, respectively( t=9.29, 2.80, 10.23, P< 0.05) using the automatic plans. The time of automatic VMAT planning was (71.49±25.48)min in 20 cases. Conclusions:The proposed automatic planning based on dose prediction and an iterative optimization algorithm is feasible and has great potential for sparing OARs and improving the utilization rate of clinical resources.

Objective To investigate the relationship between the expression level of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) and clinical prognosis of liver transplantation for hepatocellular carcinoma. Methods The clinical data of 94 recipients undergoing liver transplantation for hepatocellular carcinoma were retrospectively analyzed. The expression of 15-PGDH in the pathological tissues of all recipients was detected by immunohistochemical staining. The relationship between the expression level of 15-PGDH protein and clinical parameters of hepatocellular carcinoma patients was analyzed. The 5-year tumor-free survival and overall survival rates of liver transplant recipients were calculated. The possible independent risk factors of the clinical prognosis of liver transplant recipients were analyzed. Results The expression level of 15-PGDH was significantly correlated with age, Child-Pugh grade and preoperative level of alpha-fetoprotein (AFP) of the recipients (all P < 0.05). The tumor-free survival and overall survival rates of the recipients with low expression of 15-PGDH were significantly lower than those in their counterparts with high expression of 15-PGDH (both P < 0.05). The expression level of 15-PGDH, degree of tumor differentiation and American Joint Committee on Cancer (AJCC) staging were the independent risk factors of clinical prognosis of liver transplantation for hepatocellular carcinoma (all P < 0.05). Conclusions The expression level of 15-PGDH is an independent risk factor of clinical prognosis of liver transplantation for hepatocellular carcinoma.

Objective: To compare the efficacies of two training protocols, i.e. the multimedia instruction and the conventional method, in periodontal surgery teaching for undergraduate students. Methods: One hundred and twenty-three dental undergraduates in their pre-clinical training course were recruited and divided into two groups according to the learning grade matching principle: the experimental group (multimedia instruction, 60 students) and the control group (conventional method, 63 students). The teaching aim was to train the students gingivectomy and periodontal flap surgery by using the pig jaws. The conventional teaching method of teacher-demonstrating and student-practicing was used in the control group, and the practice time of the students′ for each surgery was 45 minutes. A standardized teaching video combined with the teachers′ explanations of the key steps was used in the experimental group. The students′ practice time for each surgery was 60 minutes. The efficacy of teaching protocol was evaluated by the teachers according to the scoring criteria set by the teaching group. Results: In gingivectomy training, accuracy of fixed points, angle of postoperative gingival margin and morphology of gingiva of the experimental group were better than those of the control group. The experimental group also had more complete and continuous excised gingivae and more thorough adjacent gingival removal. The total scores of the experimental group were significantly higher than those of the control group (92.8±2.6 vs. 89.9±3.7, P<0.05). In periodontal flap surgery training, the experimental group operated the blade around the shape of the tooth better in internal bevel incision than the control group. Additionally, the incision position of internal bevel incision, periosteal integrity after flapping and flap depth of the experimental group were better than those of the control group. Besides, the experimental group had smoother flap edge and more thorough debridement. The total scores of the experimental group were significantly higher than those of the control group (92.2±4.1 vs. 89.2±4.4, P<0.05). Conclusions The teaching efficacy of multimedia instruction was better than that of the conventional method. Its value needs to be further tested in future teaching practice.