Targeting ferroptosis for treatment of Alzheimer' s disease / 中国药理学通报

Alzheimer' s disease (AD) is a progressive neurodegenerative disorder histologically characterized by the presence of senile plaques and neurofibrillary tangles (NFTs) found in and around pyramidal neurons in cortical tissue. Mounting evidence suggests regional increased iron load and dyshomeostasis have been associated with oxidative stress, oxidation of proteins and lipids, and cell death, and appears to be a risk factor for more rapid cognitive decline, thereby involved in multiple aspects of the pathophysiology of AD. Ferroptosis is a newly identified iron-dependent lipid peroxidation-driven cell death and emerging evidences have demonstrated the involvement of ferroptosis in the pathological process of AD. Notably, some novel compounds targeting ferroptosis can relieve AD-related pathological symptoms in AD cells and animal model and exhibit potential clinical benefits in AD patients. This review systematically summarizes the growing molecular and clinical evidence implicating ferroptosis in the pathogenesis of AD, and then reviews the application of ferroptosis inhibitors in mouse/cell models to provide valuable information for future treatment and prevention of AD.

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.

Recent progress of epigallocatechin 3-gallate for treatment of Parkinson's disease / 中国药理学通报

Epigallocatechin 3-gallate (EGCG) is an abundant polyphenolie component originating from green tea extract that has exhibited versatile bioactivities in combating several diseases. During the last decade, EGCG are effective in experimental models of Parkinson's disease (PD). Several experimental studies suggest the pleiotropic neuroprotective effects, aiding to EGCG as an appealing therapeutic strategy in PD. Therefore, in this review we focus on the effects of EGCG on anti-apoptosis, anti-oxidant, anti-inflammation, modulation of dopamine production, and the aggregation of a-synuclein. We aim to compile the recent updates and cellular and molecular mechanisms of neuroprotection of EGCG in PD. This review highlights the pharmacological features of EGCG and its therapeutic implications in PD.

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.

Beauty of Chromatin Structure: Chromatin Accessibility / 中国生物化学与分子生物学报

Chromatin accessibility is one of the important indicators to evaluate the stability of chromatin structure, which is used to evaluate the binding ability of chromatin binding factors to chromosome DNA. It plays an important role in different nuclear processes, including gene transcription regulation and DNA damage repair. Abnormal regulation of chromatin accessibility is closely related to the occurrence and development of a variety of diseases, including tumors and neurodegenerative diseases. Therefore, exploration of this attribute has become a hot spot in the field of life science and disease. More and more new technologies came into being, such as chromatin conformation capture, high-throughput sequencing, and the combination of these two technologies. With the progress of technology, more and more factors involved in the regulation of chromosome accessibility have been found and summarized, including nucleosome occupation, histone modification and non-coding RNA. A number of large-scale genomic data have drawn the chromatin accessibility map of a variety of diseases, which provides data support for revealing the relationship between the occurrence and development of diseases and chromatin accessibility. Meanwhile, with the development of single-cell chromatin accessibility sequencing technology, the investigation for division of cell types at chromatin level was achieved, which makes up for the deficiency of solely relying on gene expression for cell type division. This review will explain the development and prospect of the research about chromatin accessibility from the aspects of chromatin composition and accessibility, factors affecting chromatin accessibility, detection methods of chromatin accessibility, and its roles in cancer, briefly.

Recent progress of neuroprotective mechanisms of luteolin in Alzheimer's disease / 中国药理学通报

Luteolin is a widely distributed type of flavone herbsand vegetables, which has diverse pharmacological activities against human ailments including Alzheimer's disease(AD). Recently, luteolin has been the most widely studied phytochemicals for their neuroprotective effects against experimental models of AD. Luteolin also improves brain insulin sensitivity and neuroinflammation, which attenuates the phosphorylation of tau and the formation of tangles, and the tendency of Aβ to form deposits. Furthermore, luteolin has anti-oxidative stress and anti-apoptosis effect in AD. The present study aims at reviewing experimental studies and describing the possible underlying molecular mechanisms by which luteolin and the related compounds protect against AD.

Recent progress on neuroprotective mechanisms of tanshinone in Alzheimer's disease / 中国药理学通报

Aim Tanshinones, lipophilic diterpenes isolated from the rhizome of Salvia miltiorrhiza, have diverse pharmaco¬logical activities against Alzheimer's disease (AD).Recently tanshinones have been the most widely studied phytochemicals for their neuroprotective effects against experimental models of AI).Recent studies have shown that tanshinones can inhibit choli nest erase activity, regulate generation and aggregation of beta-amyloid, regulate tail phosphorylation and exert anti-inflam¬matory effects, thereby playing a neuroprotective role in AI).'Hie present study aims at reviewing experimental studies and de¬scribing the possible underlying molecular mechanisms by which tanshinones and releated compounds protect against 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.

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.

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.

Current advances in understanding neuroprotective effect of acteoside in neurodegenerative disease / 中国药理学通报

Acteoside is among the most widespread of thedisaccharide caffeoyl esters that are widely distributed in the plant kingdom with diverse biological activities. Recent studies have shown that acteoside has neuroprotective activity in neurodegenerative diseases. This review examines and extrapolates from the recent literature to build support for the use of acteoside in mitigating neuropathy in neurodegenerative disease, including Parkinson ' s disease (PD) and Alzheimer' s disease (AD). We summarize the main pharmacokinetic parameters of acteoside in animals after different administration routes. Meanwhile, we point out both problems and shortcomings, and highlight its future development trend.

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.

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.

Loss of the posteromedial support: a risk factor for implant failure after fixation of AO 31-A2 intertrochanteric fractures / 中华医学杂志(英文版)

BACKGROUND@#The purpose of this study was to analyze cases of AO31-A2 intertrochanteric fractures (ITFs) and to identify the relationship between the loss of the posteromedial support and implant failure.@*METHODS@#Three hundred ninety-four patients who underwent operative treatment for ITF from January 2003 to December 2017 were enrolled. Focusing on posteromedial support, the A2 ITFs were divided into two groups, namely, those with (Group A, n = 153) or without (Group B, n = 241) posteromedial support post-operatively, and the failure rates were compared. Based on the final outcomes (failed or not), we allocated all of the patients into two groups: failed (Group C, n = 66) and normal (Group D, n = 328). We separately analyzed each dataset to identify the factors that exhibited statistically significant differences between the groups. In addition, a logistic regression was conducted to identify whether the loss of posteromedial support of A2 ITFs was an independent risk factor for fixation failure. The basic factors were age, sex, American Society of Anesthesiologists (ASA) score, side of affected limb, fixation method (intramedullary or extramedullary), time from injury to operation, blood loss, operative time and length of stay.@*RESULTS@#The failure rate of group B (58, 24.07%) was significantly higher than that of group A (8, 5.23%) (χ = 23.814, P < 0.001). Regarding Groups C and D, the comparisons of the fixation method (P = 0.005), operative time (P = 0.001), blood loss (P = 0.002) and length of stay (P = 0.033) showed that the differences were significant. The logistic regression revealed that the loss of posteromedial support was an independent risk factor for implant failure (OR = 5.986, 95% CI: 2.667-13.432) (P < 0.001).@*CONCLUSIONS@#For AO31-A2 ITFs, the loss of posteromedial support was an independent risk factor for fixation failure. Therefore, posteromedial wall reconstruction might be necessary for the effective treatment of A2 fractures that lose posteromedial support.

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.