Objective: To study the alterations of mitochondrial biological characteristics during both cellular replicative and premature senescence induced by hydrogen peroxide in human embryonic lung fibroblasts (HEFs). Methods: The premature senescence was induced by 400 μmol/L H₂O₂ once a day at the same time and with 2 hours each time, after four consecutive days the premature senescence models were classified into premature senescence initiation group (PSi) and premature senescence persistence group (PSp). Based on the life span of HEFs, the cell replicative senescence was divided into five groups included young-age (22 PDL), middle-age (35 PDL), replicative senescence (49 PDL), PSi and PSp. The mitochondrial distribution, relative content, adenosine triphosphate (ATP) contents, 8-hydroxydeoxyguanosine (8-OHdG) levels, the relative mitochondrial transcription factor A (TFAM) as well as mitochondrial DNA methyltransferase 1 (mtDNMT1) mRNA levels, mtDNA copy number, the relative TFAM protein level and the total enzyme activity of mitochondrial DNA methyltransferases (mtDNMTs) were detected in five senescence groups. Results: The mtDNA copy number, 8-OHdG contents, level of mtDNMT1 mRNA and mtDNMTs activity in 49 PDL group were higher than those in 22 PDL group (all P values <0.05); The level of 8-OHdG in PSi was higher than that in 22 PDL group (P<0.05); The ATP contents, mtDNA copy number, the mRNA and protein expression levels of TFAM and mtDNMTs activity of PSp were higher than those in 22 PDL group (all P values<0.05). Conclusion During the cellular senescence of HEFs, the higher mtDNA copy number and mtDNMTs activity were common features regardless of replicative or premature senescence, with possibility that oxidative stress was involved in modifying the occurrence of premature senescence.

Objective: To investigate the application and surgical experience of total laparoscopic pancreaticoduodenectomy (TLPD) in treating children with solid pseudopapillary neoplasm (SPN) of pancreas. Methods: Clinical data 4 children with SPN who underwent TLPD in Jilin University First Hospital from April 2017 to June 2018 were retrospectively analyzed. Results: Among the 4 children, a case was male and 3 cases were female. Their age ranged from 9 to 14 year-old, the height ranged from 1.2 to 1.7 meters, and body weight ranged from 30 to75 kg. All patients complained of upper abdominal pain, one child had nausea and vomiting, and one child had abdominal mass. All patients underwent abdominal enhanced CT scan before operation, which showed a mass-like low-density shadow or mixed density shadow in the pancreatic head, with slightly uneven enhancement or no obvious enhancement. All 4 patients underwent TLPD, and the operation was successful without conversion to open surgery. The duration of operation time ranged from 250 to 365 minutes, the intraoperative blood loss ranged from 80 to 120 ml, the tumor size ranged from 4 to 8 cm, and the hospital stay ranged from 10 to 22 days. One patient developed grade B pancreatic fistula after surgery and was cured after conservative treatment. Pathological examinations of all patients confirmed the diagnosis of pancreatic SPN. All patients were followed up until February 2019, and no significant discomfort was observed and no recurrence or metastasis was found. Conclusions TLPD was safe and feasible in children in relatively large pancreatic surgery centers with extensive laparotomy and TLPD experience.

Objective To study the alterations of mitochondrial biological characteristics during both cellular replicative and premature senescence induced by hydrogen peroxide in human embryonic lung fibroblasts (HEFs). Methods The premature senescence was induced by 400 μmol/L H2O2 once a day at the same time and with 2 hours each time, after four consecutive days the premature senescence models were classified into premature senescence initiation group (PSi) and premature senescence persistence group (PSp). Based on the life span of HEFs, the cell replicative senescence was divided into five groups included young-age (22 PDL), middle?age (35 PDL), replicative senescence (49 PDL), PSi and PSp. The mitochondrial distribution, relative content, adenosine triphosphate (ATP) contents, 8?hydroxydeoxyguanosine (8?OHdG) levels, the relative mitochondrial transcription factor A (TFAM) as well as mitochondrial DNA methyltransferase 1 (mtDNMT1) mRNA levels, mtDNA copy number, the relative TFAM protein level and the total enzyme activity of mitochondrial DNA methyltransferases (mtDNMTs) were detected in five senescence groups. Results The mtDNA copy number, 8?OHdG contents, level of mtDNMT1 mRNA and mtDNMTs activity in 49 PDL group were higher than those in 22 PDL group (all P values<0.05); The level of 8?OHdG in PSi was higher than that in 22 PDL group (P<0.05); The ATP contents, mtDNA copy number, the mRNA and protein expression levels of TFAM and mtDNMTs activity of PSp were higher than those in 22 PDL group (all P values<0.05). Conclusion During the cellular senescence of HEFs, the higher mtDNA copy number and mtDNMTs activity were common features regardless of replicative or premature senescence, with possibility that oxidative stress was involved in modifying the occurrence of premature senescence.

Objective To study the alterations of mitochondrial biological characteristics during both cellular replicative and premature senescence induced by hydrogen peroxide in human embryonic lung fibroblasts (HEFs). Methods The premature senescence was induced by 400 μmol/L H2O2 once a day at the same time and with 2 hours each time, after four consecutive days the premature senescence models were classified into premature senescence initiation group (PSi) and premature senescence persistence group (PSp). Based on the life span of HEFs, the cell replicative senescence was divided into five groups included young-age (22 PDL), middle?age (35 PDL), replicative senescence (49 PDL), PSi and PSp. The mitochondrial distribution, relative content, adenosine triphosphate (ATP) contents, 8?hydroxydeoxyguanosine (8?OHdG) levels, the relative mitochondrial transcription factor A (TFAM) as well as mitochondrial DNA methyltransferase 1 (mtDNMT1) mRNA levels, mtDNA copy number, the relative TFAM protein level and the total enzyme activity of mitochondrial DNA methyltransferases (mtDNMTs) were detected in five senescence groups. Results The mtDNA copy number, 8?OHdG contents, level of mtDNMT1 mRNA and mtDNMTs activity in 49 PDL group were higher than those in 22 PDL group (all P values<0.05); The level of 8?OHdG in PSi was higher than that in 22 PDL group (P<0.05); The ATP contents, mtDNA copy number, the mRNA and protein expression levels of TFAM and mtDNMTs activity of PSp were higher than those in 22 PDL group (all P values<0.05). Conclusion During the cellular senescence of HEFs, the higher mtDNA copy number and mtDNMTs activity were common features regardless of replicative or premature senescence, with possibility that oxidative stress was involved in modifying the occurrence of premature senescence.

Objective To compare the dosimetric difference among plans designed by 4-field,6-field TomoDirect and TomoHelical techniques in Tomotherapy system for left-breast cancer patients with radiotherapy after breast-conserving surgery.Method A total of 16 patients with left-breast cancer following breast-conserving surgery and intensity-modulated radiation therapy were enrolled in this retrospective study.The 4-field TomoDirect (TD4),6-field TomoDirect (TD6),and TomoHelical (TH) techniques were applied to design simulation plans in tomotherapy system for each patient,respectively.The differences of dose distribution and treatment parameters were analyzed in this study.Results Three plans all met the clinical requirement.Thereinto,TD4 was superior to TH in the dose limitation of organs at risk (OARs),especially the max dose of cord and right-breast,thc 5 Gy radiation volume of lung,and the mean dose of heart(F =595.60,129.24,60.44,65.37,P ＜ 0.05),but inferior to TH in dose homogeneity (HI) and conformity (CI) (F =2.78,60.93,P ＜ 0.05).However,TD6 improved TD4's HI and CI when delivered the lower OARs dose compared to TH.Meanwhile,the number of monitor units was less in TD technique and reduced the treatment times (F =24.89,3.75,P ＜ O.05).Conclusions For the radiotherapy of left-breast cancer patients after breast-conserving surgery,TD6 technique appeared to be superior,with the lower radiation dose of OARs compared to TH technique,and the better target's HI and CI in comparison with TD4 technique,especially in patients with early stage breast cancer.

BACKGROUND:In the treatment of tibial plateau fractures, because of the variety of fracture, the complexity of anatomical changes, X-ray films or three-dimensional CT scan limited by two-dimensional plane, increases the difficulty in preoperative plan and surgical treatment. The application of three-dimensional (3D) printing technology has attracted attention in the department of orthopedics. OBJECTIVE:To explore the auxiliary role of 3D printing technique in preoperative plan and treatment for tibial plateau fractures. METHODS:Thirty patients with tibial plateau comminuted fractures were enroled in this study and divided into two groups: experimental and control groups, with 15 patients in each group. In the experimental group, patients underwent 3D CT scan, which was stored in DICOM format, and processed by Mimics software. Data were converted into STL format, entered 3D printer, and a 1:1 entity size of the fracture model was made, in accordance with repair plan of 3D fracture model. Operation time and intraoperative blood loss were compared between the two groups. At 12 months after treatment, their outcomes were assessed using Rasmussen evaluation criteria. RESULTS AND CONCLUSION: The 3D printing fracture models of 1:1 ratio identified fracture type and made a repair program before surgery in the experimental group. Operation time and intraoperative blood loss were significantly less in the experimental group than in the control group (P < 0.05). After surgery, patients were folowed up for 12 to 18 months. The healing time was 3-5 months, averagely 4.3 months. At 12 months after treatment, the Rasmussen evaluation criteria results showed that the excelent and good rate was significantly higher in the experimental group than in the control group (P < 0.05). These results suggest that the fracture model of 3D can help to make the operation plan. The treatment of tibial plateau fractures is more precise, personalized and visual.

Background and purpose:Nasopharyngeal carcinoma usually occurs in people of states of the Southern China. Chemoradiotherapy plays an important role in the therapy of advanced nasopharyngeal carcinoma. However, chemoradiotherapy causes more toxic side effects than radiation therapy alone, which affects the therapy. Now symptomatic treatment and nutrition supports are common ways in the clinic in order to improve the tolerance of patients for the therapy, but with little effect. To evaluate the clinical significance of percutaneous endoscopic gastrostomy (PEG) in advanced nasopharyngeal carcinoma. Methods: From Oct. 2010 to Jun. 2012, a total of 71 patients with advanced nasopharyngeal carcinoma who received PEG before chemoradiotherapy were enrolled. During chemoradiotherapy, gastrostomy diet and nursing were supplied, adverse events, tolerance and nutrition indicators including weight and alcohol of human albumin were detected as well. Results:PEG were performed successfully on 68 patients, but failed in the other 3 patients. Of the 68 patients, 4 have not received concurrent chemotherapy because of liver metastases and liver function damage, 51 of the remaining 64 patients could completely ifnished 3 cycles of concurrent chemotherapy, with the completion rate of concurrent chemotherapy at 79.69%. The weight change ranged from-11.86%to 0.83%, with a mean value of-5.32%±2.99%. Paired-sample t test of human albumin before and after the treatment showed no significant difference (P=0.742). Grade Ⅱ radioactive oral cavity mucositis appeared in 60.29%patients (41/68), and 22.06%patients (15/68) suffered gradeⅢradioactive oral cavity mucositis.Conclusion:For patients with advanced nasopharyngeal carcinoma, preventative PEG improved the tolerance of chemoradiotherapy, reduce the incidence of adverse events. The period of therapy interruption caused by sever adverse event were shortened as well, PEG also increased the completion rate of concurrent chemotherapy. Nutritional status and living quality of patients are improved. In addition, PEG is a safe, economic and simple method.

Objective To investigate the clinical typing of nasopharyngeal carcinoma in patients treated by intensity-modulated radiation therapy (IMRT).Methods A retrospective analysis was performed on 333 patients with nasopharyngeal carcinoma who were initially treated in our hospital from 2003 to 2006 ;they had no distant metastasis and received IMRT.These patients were divided into 4 clinical types according to their prognosis:type Ⅰ (without local-regional recurrence and without distant metastasis),type Ⅱ (with local-regional recurrence and without distant metastasis),type Ⅲ (without local-regional recurrence and with distant metastasis),and type Ⅳ (with local-regional recurrence and with distant metastasis).Results Of all the patients,70.0％ (233) were of type Ⅰ,12.9％ (43) of type Ⅱ,16.5％ (55) of type Ⅲ,and 0.6％ (2) of type Ⅳ.Of 57 patients with stage Ⅰ-Ⅱ nasophayngeal carcinoma,86％ (49) were of type Ⅰ,11％ (6) of type Ⅱ,4％ (2) of type Ⅲ,and 0％ (0) of type Ⅳ,and of 276 patients with stage Ⅲ-Ⅳ nasopharyngeal carcinoma,66.7％ (184) were of type Ⅰ,13.4％ (37) of type Ⅱ,19.2％ (53) of type Ⅲ,and 0.7％ (2) of type Ⅳ,with significant differences between the two patient groups (P =0.007).Of the 69 patients who received IMRT alone,80％ (55) were of type Ⅰ,12％ (8) of type Ⅱ,9％(6) of type Ⅲ,and 0％ (0) of type Ⅳ; of the 218 patients who received IMRT combined with neoadjuvant plus concurrent chemotherapy,68.8％ (150) were of type Ⅰ,13.8％ (30) of type Ⅱ,16.5％(36) of type Ⅲ,and 0.9％ (2) of type Ⅳ; of the 46 patients who received IMRT combined with neoadjuvant plus adjuvant chemotherapy,61％ (28) were of type Ⅰ,11％ (5) of type Ⅱ,28％ (13) of type Ⅲ,and 0％ (0) of type Ⅳ.Conclusions In patients with early and advanced nasopharyngeal carcinoma,type Ⅰ is the most common,and type Ⅳ is the least common;type Ⅱ is more frequent than type Ⅲ in early patients,while type Ⅲ is more frequent than type Ⅱ in advanced patients.The percentage of type Ⅰ patients increases,while that of type Ⅱ-Ⅳ patients decreases,as compared with the data of those treated by conventional radiotherapy.

Objective To investigate and analyze the positioning accuracy of three imaging modalities utilized in image-guided radiotherapy (IGRT):electronic portal imaging device ( EPID),kV portal image (kV planar) and the kV cone beam computed tomography (CBCT).Methods 25 groups of setup errors were simulated on the phantom images through treatment planning system. Digitally reconstructed radiographs (DRRs) were constructed from the CT data which were subsequently used as references to register the EPID and kV planar images acquired at the original position.In addition,the reconstructed 3D-CT images were used to register the CBCT images.Finally,the setup errors using several registration methods were measured to investigate and compare the accuracies of the three imaging modalities used for patient setup.Results 675 groups of residual errors were analyzed.All combinations of imaging modalities and registration method were found to be accurate.The mean residual errors in three directions were less than 1 mm.The method based on grey value match of CBCT images was found as the most accurate with an uncertainty below 0.1 mm.When the manual match was used,the performance of kV planar was more accurate than that of EPID (residual error ＜ 0.65 mm).If automatic registration was applied,kV planar generated similar results as EPID did. Conclusions The three available imaging modalities and their corresponding registration methods are all competent for the clinical application of IGRT in our department.Considering the image quality,radiation dose and the accuracy of registration,CBCT has the priority on 1GRT followed by the kV planar.

Objective To evaluate the dosimetric characteristics of hippocampal formation (HF) in the intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC).Methods Fifty-nine NPC patients underwent IMRT.Simultaneous integrated boost technology was used to determine the doses for the target areas.The dose ranges of the HF were collected by dose-volume histogram.The influence of T stage on the exposure doses ( Dmax,Dmean,D20,V10,V20,V30,and V40 ) were compared.Results The maximum dose for the HF (Dmax) ranged from 11.1 to 78.2 Gy(F =24.2,P ＜0.05) and the Dmean ranged from 3.2 to 44.6 Gy ( F =16.3,P ＜ 0.05 ).The Dmax and Dmean of the T1-2 stage patients were (40.8 ±9.4) Gy and ( 12.5 ±5.1 ) Gy,respectively,both significantly lower than those of the T3-4 stage patients [ (58.6± 14.8) Gy,(20.9± 9.3 ) Gy].The mean exposed volume of the T4 stage patients was significantly larger than that of the T1 and T2 stages patients.Conclusions In the IMRT of NPC,the HF receives rather high irradiation dose.T stage is the main factor influencing the dose,especially T3 and T4 stages deserve serious attention.