To investigate the γ pass rate limit of plan verification equipment for volumetric modulated arc therapy (VMAT) plan verification and its sensitivity on the opening and closing errors of multi-leaf collimator (MLC), 50 cases of nasopharyngeal carcinoma VMAT plan with clockwise and counterclockwise full arcs were randomly selected. Eight kinds of MLC opening and closing errors were introduced in 10 cases of them, and 80 plans with errors were generated. Firstly, the plan verification was conducted in the form of field-by-field measurement and true composite measurement. The γ analysis with the criteria of 3% dose difference, distance to agreement of 2 mm, 10% dose threshold, and absolute dose global normalized conditions were performed for these fields. Then gradient analysis was used to investigate the sensitivity of field-by-field measurement and true composite measurement on MLC opening and closing errors, and the receiver operating characteristic curve (ROC) was used to investigate the optimal threshold of γ pass rate for identifying errors. Tolerance limits and action limits for γ pass rates were calculated using statistical process control (SPC) method for another 40 cases. The error identification ability using the tolerance limit calculated by SPC method and the universal tolerance limit (95%) were compared with using the optimal threshold of ROC. The results show that for the true composite measurement, the clockwise arc and the counterclockwise arc, the descent gradients of the γ passing rate with per millimeter MLC opening error are 10.61%, 7.62% and 6.66%, respectively, and the descent gradients with per millimeter MLC closing error are 9.75%, 7.36% and 6.37%, respectively. The optimal thresholds obtained by the ROC method are 99.35%, 97.95% and 98.25%, respectively, and the tolerance limits obtained by the SPC method are 98.98%, 97.74% and 98.62%, respectively. The tolerance limit calculated by SPC method is close to the optimal threshold of ROC, both of which could identify all errors of ±2 mm, while the universal tolerance limit can only partially identify them, indicating that the universal tolerance limit is not sensitive on some large errors. Therefore, considering the factors such as ease of use and accuracy, it is suggested to use the true composite measurement in clinical practice, and to formulate tolerance limits and action limits suitable for the actual process of the institution based on the SPC method. In conclusion, it is expected that the results of this study can provide some references for institutions to optimize the radiotherapy plan verification process, set appropriate pass rate limit, and promote the standardization of plan verification.
Humans ; Radiotherapy, Intensity-Modulated ; Immune Tolerance ; Nasopharyngeal Carcinoma ; ROC Curve ; Nasopharyngeal Neoplasms/radiotherapy*

Heterotypic cell-in-cell structures (heCICs) are closely related to tumor development and progression, and have become a new frontier in life science research. Ras-related C3 botulinum toxin substrate 1 (Rac1) belongs to the classic Rho GTPase, which plays a key role in regulating the cytoskeleton and cell movement. To investigate the role and mechanism of Rac1 in the formation of heCICs, tumor cells and immune killer cells were labeled with cell-tracker, respectively, to establish the heCICs model. Upon treatment with the Rac1 inhibitor NSC23766, the formation of heCICs between tumor and immune cells was significantly reduced. The plasmid pQCXIP-Rac1-EGFP constructed by gene cloning was packaged into pseudoviruses that subsequently infect tumor cells to make cell lines stably expressing Rac1. As a result, the formation of heCICs was significantly increased upon Rac1 overexpression. These results demonstrated a promotive role of Rac1 in heCICs formation, which may facilitate treating cell-in-cell related diseases, such as tumors, by targeting Rac1.

Objective:To evaluate the effect of obesity on in-hospital prognosis of patients with mechanical ventilation in PICU.Methods:We enrolled 301 patients who received mechanical ventilation treatment in PICU at Chongqing Medical University Affiliated Children′s Hospital, between June 2015 and June 2020, and stratified them into obese group(49 cases), overweight group(96 cases)and normal weight group(156 cases). Obesity was determined by reference to the growth and development standards published by the World Health Organization.Indicators included PICU hospital mortality, duration of mechanical ventilation, length of stay in the PICU, length of stay in hospital and the rates of duration of mechanical ventilation>21 days, re-intubation, tracheotomy, ventilator-associated pneumonia, central venous catheter infection, deep venous thrombosis and pressure ulcers were observed.The influence of obesity on hospitalized prognosis of children in PICU was analyzed.Results:In obesity group, overweight group and normal weight group, PICU hospital mortality(2.0%, 10.4%, 12.2%), the rate of tracheal reintubation(14.3%, 5.2%, 9.0%), the rate of tracheotomy (2.0%, 1.0%, 2.6%), the rate of deep venous thrombosis(8.2%, 3.1%, 5.8%), and the rate of pressure ulcers(4.1%, 7.3%, 1.9%) did not have significant difference(all P>0.05). No ventilator-associated pneumonia and central venous catheter infection occurred in three groups.There were no significant differences in the PICU hospital mortality, duration of mechanical ventilation, length of stay in the PICU, length of stay in hospital among the three groups(all P>0.05). Obesity was not an independent risk factor for in-hospital death in PICU patients on mechanical ventilation( B=1.975, SE=1.038, OR=7.206, 95% CI 0.942~55.127, P=0.057). Conclusion:Obesity does not prolong the duration of mechanical ventilation, length of stay in PICU and total length of stay in hospital, as well as not increase the rate of duration of mechanical ventilation>21 days, re-intubation, tracheotomy, ventilator-associated pneumonia, central venous catheter infection, deep venous thrombosis and pressure ulcers.Obesity is not an independent influencing factor for in-hospital death in patients with mechanical ventilation in PICU.

Effective methods for visualizing neurovascular morphology are essential for understanding the normal spinal cord and the morphological alterations associated with diseases. However, ideal techniques for simultaneously imaging neurovascular structure in a broad region of a specimen are still lacking. In this study, we combined Golgi staining with angiography and synchrotron radiation micro-computed tomography (SRμCT) to visualize the 3D neurovascular network in the mouse spinal cord. Using our method, the 3D neurons, nerve fibers, and vasculature in a broad region could be visualized in the same image at cellular resolution without destructive sectioning. Besides, we found that the 3D morphology of neurons, nerve fiber tracts, and vasculature visualized by SRμCT were highly consistent with that visualized using the histological method. Moreover, the 3D neurovascular structure could be quantitatively evaluated by the combined methodology. The method shown here will be useful in fundamental neuroscience studies.

Continuous renal replacement therapy has become an important organ support method for children with liver failure.Anticoagulation is a key step in determining the success of this treatment.Traditional systemic heparin anticoagulation has a high risk of inducing thrombocytopenia and bleeding.Protamine antagonistic heparin local anticoagulation performance is unsatisfactory.Anticoagulation without heparin is difficult to develop smoothly in children, especially low-weight infants.In recent years, regional citrate anticoagulation has gradually received attention as a new type of anticoagulation.This article reviewed the clinical application of this anticoagulation technology.

Effective methods for visualizing neurovascular morphology are essential for understanding the normal spinal cord and the morphological alterations associated with diseases. However, ideal techniques for simultaneously imaging neurovascular structure in a broad region of a specimen are still lacking. In this study, we combined Golgi staining with angiography and synchrotron radiation micro-computed tomography (SRμCT) to visualize the 3D neurovascular network in the mouse spinal cord. Using our method, the 3D neurons, nerve fibers, and vasculature in a broad region could be visualized in the same image at cellular resolution without destructive sectioning. Besides, we found that the 3D morphology of neurons, nerve fiber tracts, and vasculature visualized by SRμCT were highly consistent with that visualized using the histological method. Moreover, the 3D neurovascular structure could be quantitatively evaluated by the combined methodology. The method shown here will be useful in fundamental neuroscience studies.
Animals ; Imaging, Three-Dimensional ; Mice ; Neural Networks, Computer ; Spinal Cord/diagnostic imaging* ; Synchrotrons ; X-Ray Microtomography

Glypican-3 (GPC3) is a key member of Glypican family and plays an important role in the development, angiogenesis and metastasis of hepatocellular carcinoma (HCC). Most HCC overexpresses GPC3, but GPC3 is hardly detected in normal adult liver and benign liver lesions, so it is regarded as a highly specific diagnostic marker and an ideal therapeutic target for HCC. In this study, we cloned the heavy and light chain variable region gene from the monoclonal antibody targeted to GPC3 screened in the previous stage, and linked it with a segment of flexible peptide (Linker) to obtain the single chain antibody against GPC3. The single chain antibody gene was cloned into vector for prokaryotic expression and purified to obtain high purity protein. Detection shows that the single-chain antibody produced by us has the same binding activity with the full-length antibody, and can accurately target the tumor site of Huh7 tumor-bearing model mice after coupling Cy5.5 fluorescence, suggesting that the single-chain antibody has the potential to realize multi-directional liver cancer precise surgical navigation under the guidance of a probe.
Animals ; Antibodies, Monoclonal ; Carcinoma, Hepatocellular/genetics* ; Glypicans/genetics* ; Liver Neoplasms/diagnosis* ; Mice

Objective To investigate the effect of diabetes mellitus (DM) on adenosine postcondi-tioning-induced reduction of myocardial ischemia-reperfusion (I∕R) injury in rats. Methods Adult male Sprague-Dawley rats, weighing 230-260 g, were used in the study. Type 2 DM was induced by high-fat diet and intraperitoneal l％ streptozocin 35 mg∕kg and confirmed by fasting blood glucose concentration>16. 7 mmol∕L 72 h later. Eighteen rats with type 2 DM were divided into 3 groups (n= 6 each) using a ran-dom number table: sham operation group (DS group), I∕R group (DI∕R group) and adenosine postcondi-tioning group (DAP group). Eighteen healthy nondiabetic rats were selected and randomly divided into 3 groups (n= 6 each): sham operation group (NS group), I∕R group (NI∕R group) and adenosine postcon-ditioning group (NAP group). Myocardial I∕R was induced by 30 min occlusion of the left anterior descend-ing branch of coronary artery followed by 2 h of reperfusion. Venous blood samples were collected from the femoral vein at 2 h of reperfusion for measurement of plasma cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB) concentrations (by enzyme-linked immunosorbent assay). The rats were then sacrificed im-mediately after blood sampling for determination of the myocardial ischemic area and infarct size. Results The plasma cTnI and CK-MB concentrations were significantly increased, and the percentage of myocardial infarct size was increased after myocardial I∕R in nondiabetic and diabetic rats. Adenosine postconditioning significantly decreased plasma cTnI and CK-MB concentrations and percentage of myocardial infarct size in nondiabetic and diabetic rats (P<0. 05). Compared with group NAP, the plasma concentrations of cTnI and CK-MB were significantly increased, and the percentage of myocardial infarct size was increased in group DAP (P<0. 05). Conclusion DM can weaken cardioprotection induced by adenosine postcondition-ing in rats.

Adolescent ; Adult ; Aged ; Anemia, Aplastic ; blood ; Animals ; Apoptosis ; Bone Marrow Cells ; cytology ; Case-Control Studies ; Cells, Cultured ; Coculture Techniques ; Female ; Humans ; Male ; Mesenchymal Stromal Cells ; cytology ; Mice ; Mice, Inbred BALB C ; Middle Aged ; Serum ; Young Adult

Objective The incidence rate of sacrococcygeal tumor is low , however , due to its special position , clinical symptoms are inclined to be more severe .The aim of the article was to explore the methods and therapeutic effects of operative treat-ment for sacrococcygeal tumors . Methods A retrospective analysis was made on 44 cases of sacrococcygeal tumors treated in our hospital from January 2008 to December2012 .Of all the cases , there were 11 chordomas , 9 neurinoma , 4 malignant fibrous histioto-ma, 4 giant cell tumor, 7 metastases tumors and 9 others.All the patients had definite pathological diagnosis after operation .Operative treatments involved simple resection of rumors , simple resection of lesions and resection of lesions plus screw-rod system internal fixa-tion. Res ults No patients died in perioperative period .Follow-up was made in all patients for the average time of 3.3 years(4 months to 59 months).Except for 4 patients'delayed healing of incision operation and 1 patient′s healing of operation incision after de-bridement , all the other patients healed after enhancing the wound dressing , among which there are 3 cases of chordoma recurrence , 1 case of giant cell tumor recurrence , 3 death cases of malignant fibrous histiotoma in 2 years and 1 case alive with tumor .All patients with metastases tumor died in 3 years.Except 1 patients with osteosarcoma alive with tumor , all patients′symptoms had been alleviated after operation. Conclusion Chordoma and giant cell tumor still have a high recurrence rate after operation . The extent of rumor resection and nerve preservation are determined by the range of tumors.Preoperative embolization of the internal iliac artery can clearly reduce bleeding and improve the operation safety .