Dose reconstruction of volumetric modulated arc therapy for nasopharyngeal carcinoma based on log files and CBCT / 中华放射肿瘤学杂志

Objective:To reconstruct the dose of nasopharyngeal carcinoma and verify the results of the whole-process radiotherapy plan based on log files and cone beam CT (CBCT).Methods:A total of 15 patients with nasopharyngeal carcinoma who received volumetric modulated arc therapy (VMAT) with Halcyon accelerator in the Cancer Center of Union Hospital, Tongji Medical College, Huazhong University of Science and Technology from February to September 2022 were retrospectively selected. Log files and CBCT for all fractionated radiotherapy were recorded. The errors of monitor unit (MU), gantry angle, and multi-leaf collimator (MLC) leaf position per control point were analyzed. The adaptive CT (aCT) were generated according to CBCT and planned CT (pCT) using a commercial software Velocity TM, and the similarities among aCT, pCT and CBCT were analyzed. The original plan was modified from the log files and imported into the treatment planning system to calculate the delivered dose on the corresponding fractionated aCT to reconstruct the fractionated dose. And all the reconstructed doses were mapped back to pCT to obtain the cumulative dose. Theγpass ratios with criteria of 2 mm/2% and 2 mm/3% and the dose differences between the planned dose and the cumulative dose in the planning target volume (PTV) and organs at risk (OAR) were compared. Results:The root mean square (RMS) and the 95th percentile of the errors of MU, gantry angle and MLC leaf position errors were within an acceptable range. The aCT generated by Velocity TM had the anatomical structure of CBCT and the resolution, contrast, noise characteristics of pCT, which could be directly used for dose calculation. Compared with the planned dose, the changes of V 70 Gy of nasopharyngeal primary tumor (PTV nx), V 68 Gy of cervical glands (PTV nd) and V 60 Gy of planning target volume (PTV1) were -0.88%±1.91%, -2.99%±2.99% and -0.63%±0.93%, respectively, and V 40 Gy of parotid gland was increased to 2.65%±2.63%. Cumulative dose showed different degrees of PTV dose decrease ( P<0.05) and parotid dose was increased ( P<0.05). The γ pass ratio (2 mm/3%) between the cumulative dose and planned dose was 97.3%±2.7% and >95.0% in 86.7% of patients. Conclusions:Based on the log files and CBCT, the whole-process dose reconstruction of nasopharyngeal carcinoma patients can be carried out. According to the results of dose reconstruction, the radiotherapy effect of the target area and OAR can be quantitatively evaluated. In the case of high dose coverage and conformity of the original plan, the reconstruction results show that the cumulative dose coverage of the target area is decreased, whereas that of the parotid gland is increased.

A deep learning method for generating pseudo-CT by cone beam CT in radiotherapy / 中华放射肿瘤学杂志

Objective:To investigate the pseudo-CT generation from cone beam CT (CBCT) by a deep learning method for the clinical need of adaptive radiotherapy.Methods:CBCT data from 74 prostate cancer patients collected by Varian On-Board Imager and their simulated positioning CT images were used for this study. The deformable registration was implemented by MIM software. And the data were randomly divided into the training set ( n=59) and test set ( n=15). U-net, Pix2PixGAN and CycleGAN were employed to learn the mapping from CBCT to simulated positioning CT. The evaluation indexes included mean absolute error (MAE), structural similarity index (SSIM) and peak signal to noise ratio (PSNR), with the deformed CT chosen as the reference. In addition, the quality of image was analyzed separately, including soft tissue resolution, image noise and artifacts, etc. Results:The MAE of images generated by U-net, Pix2PixGAN and CycleGAN were (29.4±16.1) HU, (37.1±14.4) HU and (34.3±17.3) HU, respectively. In terms of image quality, the images generated by U-net and Pix2PixGAN had excessive blur, resulting in image distortion; while the images generated by CycleGAN retained the CBCT image structure and improved the image quality.Conclusion:CycleGAN is able to effectively improve the quality of CBCT images, and has potential to be used in adaptive radiotherapy.

Predicting respiratory motion using an Informer deep learning network / 中华放射医学与防护杂志

Objective:To investigate a time series deep learning model for respiratory motion prediction.Methods:Eighty pieces of respiratory motion data from lung cancer patients were used in this study. They were divided into a training set and a test set at a ratio of 8∶2. The Informer deep learning network was employed to predict the respiratory motions with a latency of about 600 ms. The model performance was evaluated based on normalized root mean square errors (nRMSEs) and relative root mean square errors (rRMSEs).Results:The Informer model outperformed the conventional multilayer perceptron (MLP) and long short-term memory (LSTM) models. The Informer model yielded an average nRMSE and rRMSE of 0.270 and 0.365, respectively, at a prediction time of 423 ms, and 0.380 and 0.379, respectively, at a prediction time of 615 ms.Conclusions:The Informer model performs well in the case of a longer prediction time and has potential application value for improving the effects of the real-time tracking technology.

Incidence and prognosis of olfactory and gustatory dysfunctions related to infection of SARS-CoV-2 Omicron strain: a national multi-center survey of 35 566 population / 中华耳鼻咽喉头颈外科杂志

Objective: This cross-sectional investigation aimed to determine the incidence, clinical characteristics, prognosis, and related risk factors of olfactory and gustatory dysfunctions related to infection with the SARS-CoV-2 Omicron strain in mainland China. Methods: Data of patients with SARS-CoV-2 from December 28, 2022, to February 21, 2023, were collected through online and offline questionnaires from 45 tertiary hospitals and one center for disease control and prevention in mainland China. The questionnaire included demographic information, previous health history, smoking and alcohol drinking, SARS-CoV-2 vaccination, olfactory and gustatory function before and after infection, other symptoms after infection, as well as the duration and improvement of olfactory and gustatory dysfunction. The self-reported olfactory and gustatory functions of patients were evaluated using the Olfactory VAS scale and Gustatory VAS scale. Results: A total of 35 566 valid questionnaires were obtained, revealing a high incidence of olfactory and taste dysfunctions related to infection with the SARS-CoV-2 Omicron strain (67.75%). Females(χ2=367.013, P<0.001) and young people(χ2=120.210, P<0.001) were more likely to develop these dysfunctions. Gender(OR=1.564, 95%CI: 1.487-1.645), SARS-CoV-2 vaccination status (OR=1.334, 95%CI: 1.164-1.530), oral health status (OR=0.881, 95%CI: 0.839-0.926), smoking history (OR=1.152, 95%CI=1.080-1.229), and drinking history (OR=0.854, 95%CI: 0.785-0.928) were correlated with the occurrence of olfactory and taste dysfunctions related to SARS-CoV-2(above P<0.001). 44.62% (4 391/9 840) of the patients who had not recovered their sense of smell and taste also suffered from nasal congestion, runny nose, and 32.62% (3 210/9 840) suffered from dry mouth and sore throat. The improvement of olfactory and taste functions was correlated with the persistence of accompanying symptoms(χ2=10.873, P=0.001). The average score of olfactory and taste VAS scale was 8.41 and 8.51 respectively before SARS-CoV-2 infection, but decreased to3.69 and 4.29 respectively after SARS-CoV-2 infection, and recovered to 5.83and 6.55 respectively at the time of the survey. The median duration of olfactory and gustatory dysfunctions was 15 days and 12 days, respectively, with 0.5% (121/24 096) of patients experiencing these dysfunctions for more than 28 days. The overall self-reported improvement rate of smell and taste dysfunctions was 59.16% (14 256/24 096). Gender(OR=0.893, 95%CI: 0.839-0.951), SARS-CoV-2 vaccination status (OR=1.334, 95%CI: 1.164-1.530), history of head and facial trauma(OR=1.180, 95%CI: 1.036-1.344, P=0.013), nose (OR=1.104, 95%CI: 1.042-1.171, P=0.001) and oral (OR=1.162, 95%CI: 1.096-1.233) health status, smoking history(OR=0.765, 95%CI: 0.709-0.825), and the persistence of accompanying symptoms (OR=0.359, 95%CI: 0.332-0.388) were correlated with the recovery of olfactory and taste dysfunctions related to SARS-CoV-2 (above P<0.001 except for the indicated values). Conclusion: The incidence of olfactory and taste dysfunctions related to infection with the SARS-CoV-2 Omicron strain is high in mainland China, with females and young people more likely to develop these dysfunctions. Active and effective intervention measures may be required for cases that persist for a long time. The recovery of olfactory and taste functions is influenced by several factors, including gender, SARS-CoV-2 vaccination status, history of head and facial trauma, nasal and oral health status, smoking history, and persistence of accompanying symptoms.

Therapeutic potential of targeting SIRT1 for the treatment of Alzheimer's disease / 生理学报

Silent information regulator 1 (SIRT1) is one of the seven mammalian proteins of the sirtuin family of NAD+-dependent deacetylases. SIRT1 plays a pivotal role in neuroprotection and ongoing research has uncovered a mechanism by which SIRT1 may exert a neuroprotective effect on Alzheimer's disease (AD). Growing evidence demonstrates that SIRT1 regulates many pathological processes including amyloid-β precursor protein (APP) processing, neuroinflammation, neurodegeneration, and mitochondrial dysfunction. SIRT1 has recently received enormous attention, and pharmacological or transgenic approaches to activate the sirtuin pathway have shown promising results in the experimental models of AD. In the present review, we delineate the role of SIRT1 in AD from a disease-centered perspective and provides an up-to-date overview of the SIRT1 modulators and their potential as effective therapeutics in AD.

Automatic Post-operative Cervical Cancer Target Area and Organ at Risk Outlining Based on Fusion Convolutional Neural Network / 中国医疗器械杂志

CT image based organ segmentation is essential for radiotherapy treatment planning, and it is laborious and time consuming to outline the endangered organs and target areas before making radiation treatment plans. This study proposes a fully automated segmentation method based on fusion convolutional neural network to improve the efficiency of physicians in outlining the endangered organs and target areas. The CT images of 170 postoperative cervical cancer stage IB and IIA patients were selected for network training and automatic outlining of bladder, rectum, femoral head and CTV, and the neural network was used to localize easily distinguishable vessels around the target area to achieve more accurate outlining of CTV.

Film analysis algorithm of isocenter error based on Hough transform for the CyberKnife system / 中华放射肿瘤学杂志

Objective:A new algorithm based on Hough transform (HT) was proposed to improve the accuracy and stability of the film image analysis of Automatic Quality Assurance (AQA) test, and to explore the influence of the resolution of film image on the test results.Methods:Nine pairs of films were obtained for AQA modules in this study. Firstly, the median filter was used to preprocess the grayed-out film image to remove noise interference. Then, a global threshold was utilized to binarize the image. The images were edge-detected and the film edge line was extracted by Hough transform. The film image was transformed to the correct position. Finally, the edge of the field shadow circle and the shadow circle of the tungsten ball were extracted by the edge detection method and Hough transform. The radial error was finally obtained by analyzing the concentricity.Results:There was no significant difference in the accuracy between the test results yielded by the HT method and the AQA software ( P>0.05). The difference in the standard deviation of the test results was statistically significant ( P=0.027), indicating that the algorithm increased the stability while ensuring the accuracy of film analysis. Increasing the resolution of film scanning failed to significantly improve the accuracy and stability of film analysis in both two methods. Conclusions:The algorithm used in this study can eliminate the human error caused by film scanning placement while ensuring the accuracy of film analysis, providing a more stable way for the AQA test of the CyberKnife system.

Prognostic Value of / 中国实验血液学杂志

OBJECTIVE@#To investigate the prognostic value of metabolic parameters of @*METHODS@#The clinical data of 58 patients with DLBCL who were examined by @*RESULTS@#The SUV@*CONCLUSION@#MTV and TLG are independent risk factors for OS and PFS in patients with DLBCL, which may be valuable for prognosis of patients with DLBCL.

Analysis of the influence of tracking error of Xsight lung tracking system caused by cardiac beating / 中华放射肿瘤学杂志

Objective:To analyze the influence of tracking error of Xsight lung tracking system caused by cardiac beating.Methods:48 patients with lung tumors adjacent to the heart were enrolled into this study. The tumor movement curves were collected by the Xsight lung tracking system and recorded in the treatment log files during the Cyberknife treatment process. The curves were subject to filtering analysis and the respiratory motion of < 1 Hz and the cardiac beating motion of > 1 Hz were separated. According to the filtering results, the patient treatment tracking data were divided into two groups based on whether the cardiac beating wave of >1 Hz existed. The tracking errors were statistically compared between two groups based on the X-ray imaging data collected by Xsight lung tracking system during treatment.Results:For the fractionation with cardiac beat information, the tracking errors of the patient′s related models were (1.45 ± 0.99), (0.46 ± 0.21) and (0.70 ± 0.54) mm in the left-right, superior-inferior and anterior-posterior direction, respectively. For the fractionation without cardiac beat information, the tracking errors of the patient′s related models were (1.52 ± 1.17), (0.63 ± 0.37) and (1.07 ± 0.62) mm in the left-right, superior-inferior and anterior-posterior direction, respectively. The tracking errors in the superior-inferior and anterior-posterior direction of patients with accurate cardiac beat models were 28.34% and 34.86% less than those of their counterparts without accurate cardiac beat models and there was significant difference (both P<0.05). Conclusion:The tracking accuracy of Xsight lung tracking system will be significantly improved if the cardiac beat model is accurately established.

Radiosensitivity enhancement effect of FePd@CNTs nanocomposites on MCF-7 cells / 中华放射肿瘤学杂志

Objective:To evaluate the radiosensitivity enhancement effect of FePd@CNTs nanocomposites on human breast cancer MCF-7 cells.Methods:FePd@CNTs nanocomposites were synthesized by chemical reduction method. Transmission electron microscope and energy dispersive spectrometer were utilized to characterize the surface morphology and chemical composition of FePd@CNTs nanocomposites. The compatibility of FePd@CNTs nanocomposites with human normal breast epithelial MCF-10A cells was determined by CCK-8 assay. The radiosensitivity enhancement effect of FePd@CNTs nanocomposites on MCF-7 cells was assessed by CCK-8 assay, flow cytometry and clony formation assay.Results:FePd nanospheres were successfully modified on the surface of CNTs by chemical reduction method. FePd@CNTs nanocomposites showed a low toxicity to MCF-10A cells (IC 50=738.3 μg/m), and effectively enhanced the effect of X-ray radiation on MCF-7 cells (sensibilization ratio=1.22). Conclusion:FePd@CNTs nanocomposites exhibit a promising potential for treating breast cancer and enhancing radiosensitivity effect.

Experimental study on the effect of olfactory training on olfactory function in mice with olfactory dysfunction / 中华耳鼻咽喉头颈外科杂志

To observe the effect of olfactory training on mice with olfactory dysfunction induced by 3-methylindole (3-MI). Thirty-one male BALB/c mice were randomly divided into 3 groups by random digits table: control group (group A, 10), olfactory dysfunction group (group B, 10) and olfactory dysfunction+olfactory training group (group C, 11). Mice in group B and group C were intraperitoneally injected with 150 mg/kg 3-MI to induce olfactory dysfunction model, while mice in group A were intraperitoneally injected with corn oil of the same volume. From the first day after injection, mice in group C were treated with 4 kinds of odors by inhalation, while mice in group B were treated with distilled water by inhalation, with 2 times/d, 30 min/time/kind of odor, and continuous training for 28 d. Group A was not treated. Buried food pellet tests were conducted before injection and at 7, 14, 21 and 28 days after injection, respectively. The olfactory epithelium was harvested for observation of the number of olfactory marker protein (OMP) and the thickness of olfactory epithelium on the 28th day after injection. SPSS 23.0 software was used for statistical analysis. Before injection, all mice in each group had no olfactory dysfunction. At the 7th, 14th, 21st and 28th days after injection, the food finding time of mice in group C was shorter than that in group B, and the difference was statistically significant ((175.88±100.50) s (266.73±46.83) s, (132.00±84.62) s (264.10±48.50) s, (103.57±77.43) s (197.43±69.78) s, (67.79±32.54) s (176.63±61.06) s, all 0.05), but food finding time of mice in group B and C was longer than that in group A (the food finding time of group A at the 7th, 14th, 21st and 28th days after injection was (27.13±5.36) s, (25.83±7.28) s, (23.13±2.72) s, (26.63±7.60) s, respectively, all 0.05). At the 28th day after olfactory training, the number of OMP positive cells in group B and C were fewer than that in group A, and the difference was statistically significant ((108.00±28.19)/HP (288.22±84.06)/HP, (199.33±58.55)/HP (288.22±84.06)/HP, all 0.05). The number of OMP positive cells in group C were higher than that in group B (0.05). The number of OMP positive cells had negative correlation with food finding time (=-0.886, 0.01). As for the thickness of the olfactory epithelium, the thickness of group B was thinner than that in group A and C, and the difference was statistically significant ((59.57±31.27) μm (114.55±40.70)μm (90.54±37.72) μm, all 0.05). Olfactory training can accelerate the recovery of olfactory function in 3-MI-induced olfactory impaired mice.

A fusion network model based on limited training samples for the automatic segmentation of pelvic endangered organs / 生物医学工程学杂志

When applying deep learning to the automatic segmentation of organs at risk in medical images, we combine two network models of Dense Net and V-Net to develop a Dense V-network for automatic segmentation of three-dimensional computed tomography (CT) images, in order to solve the problems of degradation and gradient disappearance of three-dimensional convolutional neural networks optimization as training samples are insufficient. This algorithm is applied to the delineation of pelvic endangered organs and we take three representative evaluation parameters to quantitatively evaluate the segmentation effect. The clinical result showed that the Dice similarity coefficient values of the bladder, small intestine, rectum, femoral head and spinal cord were all above 0.87 (average was 0.9); Jaccard distance of these were within 2.3 (average was 0.18). Except for the small intestine, the Hausdorff distance of other organs were less than 0.9 cm (average was 0.62 cm). The Dense V-Network has been proven to achieve the accurate segmentation of pelvic endangered organs.

Study on dosimetric changes between initial and second treatment plans in IMRT for large volume NSCLC / 中华放射肿瘤学杂志

Objective:To evaluate the cumulative dose of the target volume and organs at risk (OARs) in intensity-modulated radiation therapy (IMRT) for large volume non-small cell lung cancer (NSCLC) based on rigid and deformation registration methods. The dosimetric changes between the initial and second treatment plans were compared.Methods:Thirty patients treated with IMRT for large volume NSCLC with twice 4DCT scans acquired before radiotherapy and after 20 fractions of radiotherapy were recruited. The initial treatment plan (Plan 1) based on the average density projection CT (CT 1-avg) of the first 4DCT images and the second treatment plan (Plan 2) based on the average density projection CT (CT 2-avg) of the second 4DCT images were calculated. Then, the dose distributions of Plan 1 and Plan 2 were accumulated based on rigid and deformation registration methods to obtain Planrig and Plandef, respectively. Finally, the volume changes of gross tumor volume (GTV) and OARs between two CT scans were compared. The dose-volume parameters between Plan 1 and other plans (including Plan 2, Planrig and Plandef) were also statistically compared. Results:Compared with the initial CT scan, the mean volume of GTV and heart on the second CT was decreased by 44.2% and 5.5%, respectively, while the mean volume of ipsilateral lung, contralateral lung and total lung was increased by 5.2%, 6.2% and 5.8%, respectively (all P<0.05). Compared with Plan 1, the D 95%, D 98% and V 100% of target volume IGTV (GTV fusion of 10 4DCT phases) and PTV in Plan 2 did not significantly change (all P>0.05), and those in Planrig and Plandef were decreased (all P<0.05). The dose-volume parameters of spinal-cord, heart, ipsilateral lung and total lung in Plan 2, Planrig and Plandef were significantly lower than those in Plan 1(all P<0.05). Among them, the V 30Gy and D mean of heart were decreased by 27.3%, 16.5%, 15.3% and 15.2%, 6.6%, 5.6%, respectively. The V 20Gy and D mean of total lung were decreased by 15.6%, 4.5%, 3.7% and 15.7%, 6.2%, 5.1%, respectively. Some dose-volume parameters (including D 95% and D 98% of target volume, V 40Gy of heart, V 20Gy and D mean of the ipsilateral lung and the total lung) of Plandef were higher than those in Planrig (all P<0.05). The Dice similarity coefficients (DSCs) of OARs after deformation registration were significantly higher than those after rigid registration ( P<0.05). Conclusions:The dose-volume parameters of OARs significantly differ between Plan 1 and Plan 2. Hence, all these parameters have a large degree of deviation in predicting radiation-induced injury of OARs. Nevertheless, the dose-volume parameters obtained by deformation registration can enhance the prediction accuracy.

Impact of accelerator operating errors on γ passing rate during dose verification of volumetric modulated arc therapy for pelvic tumors / 中华放射肿瘤学杂志

Objective:To investigate the impacts of gantry rotation angle errors, monitor unit (MU) errors, collimator and multi-leaf collimator (MLC) position errors upon the γ passing rate of dose verification in volumetric modulated arc therapy (VMAT).Methods:Ten patients with rectal cancer and 10 patients with uterine tumors were selected. The operating errors of accelerator parameters were introduced during the VMAT execution. By comparing the γ passing rates during dose verification between the simulating and original plans, the impact and sensitivity of the operating errors of each accelerator parameter on γ passing rate were analyzed.Results:When the γ criteria were set as 3%/3 mm, 3%/2 mm and 2%/2 mm, the γ passing rate decreasing gradient was less than 7.0% after the introduction of gantry rotation angle, MU and collimator position errors, respectively. However, after the reverse, opposite, and co-directional motion errors of the MLC blades on both sides were introduced, the γ passing rate decreasing was less than 19.13 %, 18.53%, 0.19 %; 19.87%, 20.01%, 0.42 % and 23.11%, 23.45%, 0.65 % for absolute dose verification, respectively.Conclusion:During VMAT, the reverse and opposite motion errors of MLC blades exert more significant effect on the γ passing rate compared with the gantry rotation angle errors, MU errors, collimator position errors and co-directional motion errors of the MLC blades. When the γ criteria of 3%/3 mm, 3%/2 mm and 2%/2 mm are adopted, the impact of accelerator operating errors upon the γ passing rate is strengthened in sequence. Therefore, when performing dose verification for a specific patient, appropriate γ criteria should be chosen and absolute dose verification should be taken as the reference index to evaluate the consistency between the calculated and measured dose distribution.

Research on automatic segmentation of female bowel based on Dense V-Network neural network / 中华放射肿瘤学杂志

Objective:To resolve the issue of poor automatic segmentation of the bowel in women with pelvic tumors, a Dense V-Network model was established, trained and evaluated to accurately and automatically delineate the bowel of female patients with pelvic tumors.Methods:Dense Net and V-Net network models were combined to develop a Dense V-Network algorithm for automatic segmentation of 3D CT images. CT data were collected from 160 patients with cervical cancer, 130 of which were randomly selected as the training set to adjust the model parameters, and the remaining 30 were used as test set to evaluate the effect of automatic segmentation.Results:Eight parameters including Dice similarity coefficient (DSC) were utilized to quantitatively evaluate the segmentation effect. The DSC value, JD, ΔV, SI, IncI, HD (cm), MDA (mm), and DC (mm) of the small intestine were 0.86±0.03, 0.25±0.04, 0.10±0.07, 0.88±0.05, 0.85±0.05, 2.98±0.61, 2.40±0.45 and 4.13±1.74, which were better than those of any other single algorithm.Conclusion:Dense V-Network algorithm proposed in this paper can deliver accurate segmentation of the bowel organs. It can be applied in clinical practice after slight revision by physicians.

Risk factors of recurrent kyphosis in thoracolumbar burst fracture patients treated by short segmental pedicle screw fixation / 北京大学学报(医学版)

OBJECTIVE@#To analyze the risk factors of recurrent kyphosis after removal of short segmental pedicle screw fixation in patients with thoracolumbar burst fractures.@*METHODS@#Retrospective analysis was conducted of 144 cases of thoracolumbar burst fractures without neurological impairment treated in Peking University Third Hospital from January 2010 to December 2017. There were 74 males and 70 females, with an average age of (39.1±13.2) years. The distribution of the injured vertebrae was T12: 42, L1: 72 and L2: 30, with fracture types of A3: 90, B1: 25 and B2: 29. The patients were divided into two groups: Recurrent kyphosis group (n=92) and non-recurrent kyphosis group (n=52). SPSS 26.0 software was used for univariate analysis and Logistic regression analysis.@*RESULTS@#The average follow-up time was 28 (20-113) months. The imaging indexes of pre-operation, 3 days post-operation, 12 months post-operation and the last follow-up were measured and compared. Anterior vertebral body height, segmental kyphosis, vertebral wadge angle and Gardner deformity were significantly improved after operation (P < 0.05), and there were some degrees of loss in the 1-year follow-up; anterior vertebral body height and vertebral wadge angle were no longer changed after the removal of the screws; however, segmental kyphosis and Gardner deformity were still aggravated after the removal of the screws (P < 0.05). There were some degrees of collapse of the height of the upper and lower discs during the follow-up. Univariate analysis showed that there were statistically significant differences (P < 0.05) between the two groups in gender, age (36.9 years vs. 43.0 years), upper disc injury, CT value (174 vs. 160), segmental kyphosis (16.6° vs. 13.3°), vertebral wadge angle (16.7° vs. 13.6°), Gardner deformity (19.1° vs. 15.2°) and ratio of anterior vertebral body height (0.65 vs. 0.71). Logistic regression analysis showed that male (OR: 2.88, 95%CI: 1.196-6.933), upper disc injury (OR: 2.962, 95%CI: 1.062-8.258) and injured vertebral wedge angle were risk factors of recurrent kyphosis after removal of internal fixation for thoracolumbar burst fracture (P < 0.05).@*CONCLUSION@#The patients with thoracolumbar burst fracture can obtain satisfactory effect immediately after posterior short segmental pedicle screw fixation, however, there may be some degree of loss during the follow-up. Male, upper disc injury and injured vertebral wedge angle are the risk factors of recurrent kyphosis after removal of internal fixation for thoracolumbar burst fracture.

Analysis of risk factors for necrosis of femoral head after internal fixation surgery in young and mid-aged patients with femoral neck fracture / 北京大学学报(医学版)

OBJECTIVE@#To retrospectively analyze the risk factors of avascular necrosis of femoral head (ANFH) after internal fixation in young and mid-aged adults.@*METHODS@#From January 2007 to December 2017, femoral neck fracture patients (18-60 years old) treated by reduction and internal fixation were retrospectively studied in Peking University Third Hospital. We recorded their gender, age, body mass index (BMI), American Society of Anesthesiology (ASA) grade, reason of injury, fracture side, interval between injury and surgery, location of fracture line, Garden classification, Pauwels classification, reduction method (open or closed), internal fixation and reduction quality. The diagnosis of ANFH was confirmed based on X-ray and MRI images during the follow-up. The internal fixation method included cannulated compression screw (CCS) or dynamic hip screw (DHS, with or without anti-rotation screw). χ2 test and Logistic regression analysis were used to analyze the relationship between the various factors and postoperative ANFH.@*RESULTS@#A total of 113 patients were included in this study, including 63 males and 50 females with an average age of (43.17 ± 12.34) years. They were followed up by (25.08 ± 16.17) months. ASA grade included grade I (21 cases), grade II (55 cases) and grade III (37 cases). The reasons of injury included low-energy trauma (76 cases) and high-energy (37 cases). The fracture line included subcapital type (37 cases), transverse type (74 cases) and basal type (2 cases). Garden classification included type I (3 cases), type II (46 cases), type III (39 cases) and type IV (25 cases). Pauwels classification included type I (21 cases), type II (55 cases) and type III (37 cases). Interval between injury and surgery was (3.88 ± 3.66) days, 108 patients and 5 patients performed closed and open reduction respectively. 63 patients performed CCS, and 50 patients performed DHS. The reduction quality included grade A (91 cases), grade B (18 cases) and grade C (4 cases). 18 patients developed ANFH after surgery, the incidence rate was 15.93% (18/113). The result of χ2 test showed the reason of injury (OR=0.19, P < 0.01), Garden classification (OR=0.13, P < 0.01), Pauwels classification (OR=0.12, P = 0.02), internal fixation method (OR=3.29, P = 0.04) and reduction quality (OR=0.33, P < 0.01) were significantly associated with ANFH. These five factors were further included into the Logistic regression analysis, and its results showed that the reason of injury (OR=4.11, P = 0.03) and Garden classification (OR=4.85, P = 0.04) were statistically significant.@*CONCLUSION@#The reason of injury, Garden classification, Pauwels classification, internal fixation and reduction quality may increase the risk of ANFH after surgery, and the reason of injury and Garden classification were much more significant.

Subcellular localization of GTPase of immunity-associated protein 2 / 北京大学学报(医学版)

OBJECTIVE@#To analyze the subcellular localization of GTPase of immunity-associated protein 2 (GIMAP2) for the further functional study.@*METHODS@#In the study, we first obtained the protein sequences of GTPase of immunity-associated protein 2 (GIMAP2) from National Center for Biotechnology Information (NCBI) database, and then performed a prediction analysis of its transmembrane structure, nuclear localization signal (NLS), nuclear export signal (NES) and subcellular localization through bioinformatics online tools. GIMAP2 gene amplified by PCR was inserted into the expression vector pQCXIP-mCherry-N1 and positive clones were selected by ampicillin resistance. After using methods to extract and purify, the sequenced recombinant plasmid pQCXIP-GIMAP2-mCherry, together with the retroviral packaging plasmids VSVG and Gag/pol, was transferred into HEK293FT cells by liposomes for virus packaging. The virus supernatant was collected 48 h after transfection and directly infected the human breast cancer cell line MDA-MB-436. Immunofluorescence staining was constructed to detect the localization of endogenous and exogenous GIMAP2 in MDA-MB-436 cells. Meanwhile, green fluorescent chemical dyes were used to label mitochondria, endoplasmic reticulum, and lipid droplets in living MDA-MB-436 cells stably expressing the GIMAP2-mCherry fusion protein. Images for the three dye-labeled organelles and GIMAP2-mCherry fusion protein were captured by super-resolution microscope N-SIM.@*RESULTS@#Bioinformatics analysis data showed that GIMAP2 protein composed of 337 amino acids might contain two transmembrane helix (TM) structures at the carboxyl terminus, of which TMs were estimated to contain 40-41 expected amino acids, followed by the residual protein structures toward the cytoplasmic side. NES was located at the 279-281 amino acids of the carboxyl terminus whereas NLS was not found. GIMAP2 might locate in the lumen of the endoplasmic reticulum. Sequencing results indicated that the expression vector pQCXIP-GIMAP2-mCherry was successfully constructed. Fluorescent staining confirmed that GIMAP2-mCherry fusion protein, co-localized well with endogenous GIMAP2, expressed successfully in the endoplasmic reticulum and on the surface of lipid droplets in MDA-MB-436 cells.@*CONCLUSION@#GIMAP2 localizes in the endoplasmic reticulum and on the surface of LDs, suggesting potential involvement of GIMAP2 in lipid metabolism.

Clinical characteristics and outcomes of 112 cardiovascular disease patients infected by 2019-nCoV / 中华心血管病杂志

Objective: To explore the clinical characteristics and prognosis of the new coronavirus 2019-nCoV patients combined with cardiovascular disease （CVD). Methods: A retrospective analysis was performed on 112 COVID-19 patients with CVD admitted to the western district of Union Hospital in Wuhan, from January 20, 2020 to February 15, 2020. They were divided into critical group (ICU, n=16) and general group (n=96) according to the severity of the disease and patients were followed up to the clinical endpoint. The observation indicators included total blood count, C-reactive protein (CRP), arterial blood gas analysis, myocardial injury markers, coagulation function, liver and kidney function, electrolyte, procalcitonin (PCT), B-type natriuretic peptide (BNP), blood lipid, pulmonary CT and pathogen detection. Results: Compared with the general group, the lymphocyte count (0.74 (0.34, 0.94)×109/L vs. 0.99 (0.71, 1.29)×109/L, P=0.03) was extremely lower in the critical group, CRP (106.98 (81.57, 135.76) mg/L vs. 34.34 (9.55,76.54) mg/L, P<0.001) and PCT (0.20 (0.15,0.48) μg/L vs. 0.11 (0.06,0.20) μg/L, P<0.001) were significantly higher in the critical group. The BMI of the critical group was significantly higher than that of the general group (25.5 (23.0, 27.5) kg/m2 vs. 22.0 (20.0, 24.0) kg/m2，P=0.003). Patients were further divided into non-survivor group (17, 15.18%) group and survivor group (95, 84.82%). Among the non-survivors, there were 88.24% (15/17) patients with BMI> 25.0 kg/m2, which was significantly higher than that of survivors (18.95% (18/95), P<0.001). Compared with the survived patients, oxygenation index (130 (102, 415) vs. 434 (410, 444), P<0.001) was significantly lower and lactic acid (1.70 (1.30, 3.00) mmol/L vs. 1.20 (1.10, 1.60) mmol/L, P<0.001) was significantly higher in the non-survivors. There was no significant difference in the proportion of ACEI/ARB medication between the critical group and the general group or between non-survivors and survivors （all P>0.05). Conclusion: COVID-19 patients combined with CVD are associated with a higher risk of mortality. Critical patients are characterized with lower lymphocyte counts. Higher BMI are more often seen in critical patients and non-survivor. ACEI/ARB use does not affect the morbidity and mortality of COVID-19 combined with CVD. Aggravating causes of death include fulminant inflammation, lactic acid accumulation and thrombotic events.

Tradução e adaptação transcultural do instrumento Mixed Methods Appraisal Tool ao contexto brasileiro / Translation and cross-cultural adaptation of the Mixed Methods Appraisal Tool to the brazilian context / Traducción y adaptación transcultural del instrumento Mixed Methods Appraisal Tool al contexto brasileño

Objetivo: traduzir e adaptar transculturalmente o Mixed Methods Appraisal Tool para a realidade brasileira. Métodos: a metodologia seguiu os 10 passos determinados pelo processo de tradução e adaptação transcultural conduzido por uma das equipes de trabalho do Grupo de Interesse Especial em Qualidade de Vida e o Grupo de Tradução e Adaptação Cultural. Resultados: o teste com o instrumento foi realizado a partir do desenvolvimento de duas revisões sistemáticas mistas. A versão traduzida obteve coeficiente Kappa forte/substantial (k=0,67), e foi intitulado "Instrumento de avaliação da qualidade de pesquisas com métodos mistos-Versão 2011". A versão produzida apresenta componentes estruturais e semânticos compatíveis com os da versão original, permitindo boa compreensão e traz clareza em seu conteúdo. Conclusão: o instrumento traduzido e adaptado poderá ser uma ferramenta importante para a produção científica no Brasil, otimizando a produção de revisões sistemáticas nas diversas áreas do conhecimento

Objective: Transculturally translate and adapt the Mixed Methods Appraisal Tool to the Brazilian reality. Methods: The methodology followed the 10 steps determined by the transcultural translation and adaptation process conducted by one of the Working Groups of the Special Interest Group on Quality of Life and the Cultural Translation and Adaptation Group. Results: o The test with the instrument was carried out from the development of two systematic systematic reviews. The translated version obtained a strong / substantial Kappa coefficient (k = 0.67), and was titled "Method of evaluating the quality of researches with mixed methods - Version 2011". The produced version presents structural and semantic components compatible with those of the original version, allowing good understanding and brings clarity in its content. Conclusion: the translated and adapted instrument can be an important tool for scientific production in Brazil, optimizing the production of systematic reviews in the different areas of knowledge

Objetivo: traducir y adaptar transculturalmente el Mixed Methods Appraisal Tool para la realidad brasileña. Métodos: la metodología siguió los 10 pasos determinados por el proceso de traducción y adaptación transcultural conducido por uno de los equipos de trabajo del Grupo de Interés Especial en Calidad de Vida y el Grupo de Traducción y Adaptación Cultural. Resultados: La prueba con el instrumento se realizó a partir del desarrollo de dos revisiones sistemáticas mixtas. La versión traducida obtuvo coeficiente Kappa fuerte / substancial (k = 0,67), y se tituló "Instrumento de evaluación de la calidad de las investigaciones con métodos mixtos-Versión 2011". L a versión producida presenta componentes estructurales y semánticos compatibles con los de la versión original, permitiendo buena comprensión y trae claridad en su contenido. Conclusión: el instrumento traducido y adaptado podría ser una herramienta importante para la producción científica en Brasil, optimizando la producción de revisiones sistemáticas en las diversas áreas del conocimiento