HELQ suppresses migration and proliferation of non-small cell lung cancer cells by repairing DNA damage and inducing necrosis.

HELQ plays a key role in DNA damage response and cell-cycle checkpoint regulation. It has been implicated in ovarian and pituitary tumors and may play a role in germ cell maintenance. This study investigated the role of HELQ in lung cancer. The expression of HELQ in patients with non-small-cell lung cancer (NSCLC) was downregulated compared with normal human lungs. Clinical prognostic analysis of Kaplan-Meier plots revealed that patients with NSCLC with low HELQ levels had a reduced overall survival. Further, we found that HELQ depletion enhanced lung cancer cell malignancy. Furthermore, overexpression of HELQ in lung cancer cells reduced cell migration in vitro, while DNA damage repair was inhibited. Both in vitro and in vivo studies have shown that HELQ induces cell death. Mechanistically, we found that cells overexpressing HELQ showed a tendency to induce necrosis. After analyzing the database of HELQ interactors. we found that RIPK3 may interact with it and proved this conclusion by immunoprecipitation. Our findings identified the tumor suppressive role of HELQ in malignant human lung cancer and unraveled a potential therapeutic strategy for cancer treatment through HELQ activation. Moreover, HELQ may also be a predictive biomarker for the clinical predisposition, progression, and prognosis of lung cancer.

The role of ferroptosis in chronic intermittent hypoxia-induced cognitive impairment.

PURPOSE: Obstructive sleep apnea (OSA) is a sleep disorder that may lead to cognitive impairment. The primary pathophysiological feature of OSA is chronic intermittent hypoxia (CIH), but the underlying mechanisms of CIH are not known. There have been few studies on the role of ferroptosis, a novel form of programmed cell death, during CIH-induced cognitive impairment. Therefore, this paper examined ferroptosis' effect on CIH-mediated cognitive impairment. METHODS: The study randomized twenty-four Sprague-Dawley (SD) male rats to control or CIH group. CIH rats were subjected to intermittent hypoxia for 4 weeks. Rat learning and memory were analyzed by the Morris water maze (MWM) test. Alterations of hippocampal neuronal ultrastructure were observed by transmission electron microscopy (TEM). Malondialdehyde (MDA) and ferrous iron (Fe2+) levels and superoxide dismutase (SOD) and reduced glutathione (GSH) contents were determined. Ferroptosis-associated protein levels were examined by Western blotting. RESULTS: The MWM test indicated that rats in the CIH group exhibited neurocognitive impairment. TEM showed that CIH induced mitochondrial damage. Significant increases in Fe2+ and MDA levels were observed in the CIH group, and GSH and SOD levels were decreased. Expression of Acyl-CoA synthetase long-chain family member 4 (ACSL4) increased, and glutathione peroxidase 4 (GPX4) protein levels were decreased, suggesting that ferroptosis was induced in CIH model rats. The NF-E2-related factor 2 (Nrf2) protein level in the CIH group was decreased. CONCLUSION: Ferroptosis had an essential effect on CIH-mediated cognitive impairment, and it may occur via Nrf2 dysregulation. These findings lay a solid foundation for the subsequent study of OSA-associated cognitive impairment offering potential evidence for the development of therapeutic strategies.

Outcomes of different zero-profile spacers in the treatment of two-level cervical degenerative disk disease.

PURPOSE: The purpose of this study was to analyze the clinical and radiological outcomes of two different zero-profile spacers (ROI-C and anchor-C) in contiguous two-level ACDF for CDDD patients. METHODS: We retrospectively analyzed patients who underwent contiguous two-level ACDF due to CDDD between January 2015 and December 2020 in our hospital. Patients who received ROI-C and anchor-C were included as the study groups, and those who underwent plate-cage construct (PCC) were included as the control group. The primary outcome measures were radiographical parameters, and the secondary outcome measures were dysphagia, JOA scores and VAS scores for these patients. RESULTS: A total of 91 patients were enrolled in the study; there were 31, 21 and 39 patients in the ROI-C, anchor-C and PCC groups, respectively. The mean follow-up duration was 24.52 months (range, 18-48 months) in the ROI-C group, 24.38 months (range, 16-52 months) in the anchor-C group and 25.18 months (range, 15-54 months) in the PCC group. The loss of the intervertebral space height and cage subsidence rate in the ROI-C group were significantly higher than those in the anchor-C group and PCC group at the final follow-up (P < 0.05). The ROI-C group showed a lower incidence of adjacent segment degeneration than the anchor-C group and PCC group, but the difference was not significant. The fusion rates were not different among these three groups. The early dysphagia rate was significantly lower in the patients with zero-profile spacers than in the PCC group (P < 0.05), but the difference was not significant at the last follow-up. No relevant differences were found in the JOA scores and VAS scores. CONCLUSIONS: Zero-profile spacers showed promising clinical outcomes in CDDD patients having contiguous two-level ACDF. However, ROI-C resulted in a higher intervertebral space height loss and a higher cage subsidence rate than anchor-C during the follow-up.

Machine learning for the prediction of postoperative nosocomial pulmonary infection in patients with spinal cord injury.

PURPOSE: The purpose of this study was to establish the best prediction model for postoperative nosocomial pulmonary infection through machine learning (ML) and assist physicians to make accurate diagnosis and treatment decisions. METHODS: Patients with spinal cord injury (SCI) who admitted to a general hospital between July 2014 and April 2022 were included in this study. The data were segmented according to the ratio of seven to three, 70% were randomly selected to train the model, and the other 30% were used for testing. We used LASSO regression to screen the variables, and the selected variables were used in the construction of six different ML models. Shapley additive explanations and permutation importance were used to explain the output of the ML models. Finally, sensitivity, specificity, accuracy and area under receiver operating characteristic curve (AUC) were used as the evaluation index of the model. RESULTS: A total of 870 patients were enrolled in this study, of whom 98 (11.26%) developed pulmonary infection. Seven variables were used for ML model construction and multivariate logistic regression analysis. Among these variables, age, ASIA scale and tracheotomy were found to be the independent risk factors for postoperative nosocomial pulmonary infection in SCI patients. Meanwhile, the prediction model based on RF algorithm performed best in the training and test sets. (AUC = 0.721, accuracy = 0.664, sensitivity = 0.694, specificity = 0.656). CONCLUSION: Age, ASIA scale and tracheotomy were the independent risk factors of postoperative nosocomial pulmonary infection in SCI. The prediction model based on RF algorithm had the best performance.

Role of magnetic resonance imaging features in diagnosing and localization of disc rupture related to cervical spinal cord injury without radiographic abnormalities.

STUDY DESIGN: A retrospective study. OBJECTIVE: Traumatic cervical spinal cord injury (TSCI) is often associated with disc rupture. It was reported that high signal of disc and anterior longitudinal ligament (ALL) rupture on magnetic resonance imaging (MRI) were the typical signs of ruptured disc. However, for TSCI with no fracture or dislocation, there is still difficult to diagnose disc rupture. The purpose of this study was to investigate the diagnostic efficiency and localization method of different MRI features for cervical disc rupture in patient with TSCI but no any signs of fracture or dislocation. SETTING: Affiliated hospital of University in Nanchang, China. METHODS: Patients who had TSCI and underwent anterior cervical surgery between June 2016 and December 2021 in our hospital were included. All patients received X-ray, CT scan, and MRI examinations before surgery. MRI findings such as prevertebral hematoma, high-signal SCI, high-signal posterior ligamentous complex (PLC), were recorded. The correlation between preoperative MRI features and intraoperative findings was analyzed. Also, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of these MRI features in diagnosing the disc rupture were calculated. RESULTS: A total of 140 consecutive patients, 120 males and 20 females with an average age of 53 years were included in this study. Of these patients, 98 (134 cervical discs) were intraoperatively confirmed with cervical disc rupture, but 59.1% (58 patients) of them had no definite evidence of an injured disc on preoperative MRI (high-signal disc or ALL rupture signal). For these patients, the high-signal PLC on preoperative MRI had the highest diagnostic rate for disc rupture based on intraoperative findings, with a sensitivity of 97%, specificity of 72%, PPV of 84% and NPV of 93%. Combined high-signal SCI with high-signal PLC had higher specificity (97%) and PPV (98%), and a lower FPR (3%) and FNR (9%) for the diagnosis of disc rupture. And combination of three MRI features (prevertebral hematoma, high-signal SCI and PLC) had the highest accuracy in diagnosing traumatic disc rupture. For the localization of the ruptured disc, the level of the high-signal SCI had the highest consistency with the segment of the ruptured disc. CONCLUSION: MRI features, such as prevertebral hematoma, high-signal SCI and PLC, demonstrated high sensitivities for diagnosing cervical disc rupture. High-signal SCI on preoperative MRI could be used to locate the segment of ruptured disc.

LRIG2 regulates cell proliferation, migration and apoptosis of osteosarcoma.

BACKGROUND: Osteosarcoma (OS) is one of the malignant bone tumors with strong aggressiveness and poor prognosis. Leucine-rich repeats and immunoglobulin-like domains2 (LRIG2) is closely associated with the poor prognosis of a variety of tumors, but the role of LRIG2 in osteosarcoma and the underlying molecular mechanism remains unclear. OBJECTIVE: The aim of this study was to determine the function of LRIG2 in OS and the related molecular mechanism on cell proliferation, apoptosis and migration of OS. METHODS: The mRNA and protein expression of LRIG2 in OS tissues and cells was detected by qRT-PCR, western blot (WB) assay and immunohistochemistry (IHC). The cell counting Kit-8 (CCK-8), clone formation, transwell, TdT-mediated dUTP Nick-End Labeling (TUNEL) and WB assay were applied to determine the proliferation, migration and apoptosis abilities of OS cells and its molecular mechanisms. Spontaneous metastasis xenografts were established to confirm the role of LRIG2 in vivo. RESULTS: LRIG2 exhibited high expression in OS tissues and OS cell lines and the expression of which was significantly correlated with Enneking stage of patients, knockdown LRIG2 expression significantly inhibited OS cell proliferation, migration and enhanced apoptosis. Silencing LRIG2 also suppressed the growth of subcutaneous transplanted tumor in nude mice. Further, the mechanism investigation revealed that the protein level of cell proapoptotic proteins (Bax, caspase9 and caspase3) all increased attributed to LRIG2 deficiency, whereas expression of anti-apoptotic protein BCL2 decreased. LRIG2 silencing led to the decrease phosphorylation of AKT signaling, a decrease expression of vimentin and N-cadherin. Additionally, silencing LRIG2 significantly decreased the rate of tumor growth and tumor size. CONCLUSIONS: LRIG2 acts as an oncogene in osteosarcoma, and it might become a novel target in the treatment of human OS.

Incidences and reasons of postoperative surgical site infection after lumbar spinal surgery: a large population study.

PURPOSE: The purpose of this study was to determine the incidences of postoperative acute surgical site infection (SSI) after lumbar spinal surgery and its possible reasons in our hospital during the past 9 years. METHODS: This is a retrospective study with a large sample size. The medical records of all included patients were reviewed, and patients with acute SSI were identified. The incidence and possible reasons of SSI were determined. RESULTS: A total of 7240 patients who underwent posterior lumbar spinal surgery were included in this study, and the total incidence of postoperative SSI was 1.53% (111/7240). Gram-negative bacteria were found to be dominant in postoperative wound infections after lumbar spinal surgery. And Escherichia coli were the most common pathogen in patients with SSI. The rate of postoperative SSI following lumbar spinal surgery was increased at first and then decreased during the past 9 years. Additionally, from 2011 to 2014, it was mainly deep infection in these patients, and then was mainly superficial infection from 2015 to 2019. Patients with lumbar spinal stenosis had the highest incidence of postoperative SSI (2.39%, P < 0.001). There was also a significant difference for the number of SSI cases among different surgeons. CONCLUSION: Based on a large population analysis, Gram-negative bacteria were the most common pathogen in postoperative SSI after lumbar spinal surgery. And patients with lumbar spinal stenosis had the highest incidence of SSI. Increasing the intervention of Gram-negative may be an important step to reduce the postoperative SSI after lumbar spinal surgery.

[Sleeve Shaping Technique for Two Cases of Peripheral Artery Aneurysms Involving Important Branches].

Peripheral artery aneurysms,with low incidence and complex anatomic structure,often involve important branches.This paper introduces a new surgical technique-sleeve shaping on the basis of two cases.The basic data,including characteristics,imaging,operation and follow-up data of the cases,were collected.The data were then combined with the previous literature for explaining in detail that this technique can be used as a supplementary method of reconstruction following resection or endovascular repair.

[Clinical Analysis of the Treatment of Iliac Limb Occlusion Following Endovascular Abdominal Aortic Aneurysm Repair].

Objective To explore the cause and the treatment strategies of iliac limb occlusion after endovascular abdominal aortic aneurysm repair(EVAR). Methods The patients receiving EVAR in PUMC Hospital from January 2015 to December 2020 were retrospectively analyzed.Sixteen(2.7%)cases of iliac limb occlusion were identified,among which 6,9,and 1 cases underwent surgical bypass,endovascular or hybrid procedure,and conservative treatment,respectively. Results Fifteen cases were successfully treated.During the 10.6-month follow-up,2 cases receiving hybrid treatment underwent femoral-femoral bypass due to re-occlusion of the iliac limb. Conclusions Iliac limb occlusion mostly occurs in the acute phase after EVAR,and endovascular or hybrid treatment can be the first choice for iliac limb occlusion.It is suggested to focus on the risk factors for prevention.

Aurora-B knockdown inhibits osteosarcoma metastasis by inducing autophagy via the mTOR/ULK1 pathway.

BACKGROUND: Autophagy plays an essential role in metastasis of malignancies. Although our studies showed that Aurora-B facilitate pulmonary metastasis in OS, the mechanism of Aurora-B kinase on autophagy and metastasis in OS has not been explored. METHODS: Clinical-pathological parameters and follow-up information was collected in OS patients. Immunohistochemical staining was performed to detect Aurora-B and LC3 protein in OS tissues. Short hairpin RNA transfection was used to silence Aurora-B in OS cells. Real-time quantitative PCR (RT-qPCR) was performed to detect Aurora-B mRNA expression in OS cells. Aurora-B and autophagy related protein were measured by Western blot. Transmission electron microscopy and laser scanning confocal microscopy were performed to observe the formation of autophagosomes and autolysosomes. Migratory and invasive ability of OS cells were measured by Wound healing and transwell assays. Orthotopic xenograft model was used to evaluate the effect of autophagy mediated by Aurora-B inhibition on pulmonary metastasis of OS. RESULTS: The elevated expression of Aurora-B protein in OS tissues negatively associated with the overall survival of OS patients. Further investigation has found that Aurora-B expression was negatively correlative with autophagy related protein LC3 in OS patient tissues. Knockdown Aurora-B stimulates autophagy and inhibits migratory and invasive ability of OS cells. Mechanistically, Aurora-B knockdown suppressed the mTOR/ULK1 signaling pathway and reactivation of the mTOR/ULK1 pathway decreased autophagy level. Furthermore, the inhibition effect of silencing Aurora-B on migration and invasion of OS was reversed by chloroquine and mTOR activator in vitro and vivo. CONCLUSIONS: Our results suggest that silencing of Aurora-B stimulate autophagy via decreasing mTOR/ULK1 and result in inhibiting OS metastasis. Targeted Aurora-B/mTOR/ULK1 pathway may be a promising treatment strategy for OS patients.

The Efficacy and Safety of AngioJet Rheolytic Thrombectomy in the Treatment of Subacute Deep Venous Thrombosis in Lower Extremity.

BACKGROUND: The aim of this study is to examine the efficacy and safety of AngioJet rheolytic thrombectomy for the treatment of subacute deep venous thrombosis (DVT) in lower limbs. METHODS: A retrospective study was performed on 90 patients with subacute DVT (15-90 days) in lower limbs in our center from November 2015 to December 2016. In total, 27 patients with subacute DVT in lower limbs treated with AngioJet rheolytic thrombectomy were included in the study, including 17 men and 10 women. The onset time of thrombosis was between 15 and 75 days. Five patients were diagnosed bilaterally; 5 patients were diagnosed in the right lower limb; and 17 patients were affected by thrombosis in left lower limb. All the 27 cases received AngioJet rheolytic thrombectomy. RESULTS: After AngioJet thrombectomy, 17 cases were improved to grade II (50-99%), and 10 cases were grade I (<50%). Nineteen cases were treated with subsequent catheter-directed thrombolysis (CDT), and the average time of thrombolysis was 3.2 days, with an average urokinase administration dose of 7.32 million units. Among the 27 cases, 21 of them received iliac venous balloon dilation, with 10 of them being implanted with the iliac vein stent; 12 stents were implanted in total. Finally, the angiography suggested that 25 cases (92.6%) obtained a recanalization rate higher than grade II, and no serious complications occurred during the perioperative period. All patients were followed up regularly for 3 to 15 months, and 2 patients died from malignant tumor during the follow-up period. Twenty-three cases were followed up for more than 6 months; 17 cases finished 12-month follow-up. The primary patency rate at 6 and 12 months was 96.3% and 88.9%, respectively. The Villalta score of postoperative postthrombosis syndrome symptom at 6 and 12 months was 3.3 ± 2.8 and 3.5 ± 2.8, respectively. CONCLUSIONS: It is safe and feasible to use the AngioJet rheolytic thrombectomy in the treatment of subacute DVT in lower limbs. In patients without high risk of bleeding, combination of AngioJet thrombectomy and CDT is an effective treatment to reduce the thrombus volume.

Matrix metallopeptidase 9 targeted by hsa-miR-494 promotes silybin-inhibited osteosarcoma.

Osteosarcoma (OS) is the most common malignant tumor that develops in bone. Its mortality is very high. Therefore, study of mechanisms of pathogenesis of the OS is urgently required. Previous studies of microarray showed that the expression levels of matrix metallopeptidase 9 (MMP-9) altered significantly in OS. In addition, overexpression of MMP-9 is recognized as an indicator in cancer. However, the exact roles of MMP-9 in OS are not fully investigated. Thus, we firstly studied the roles of MMP-9 in OS and revealed that silence of MMP-9 inhibited OS cell proliferation as determined by MTT assay and colony formation assay. Secondly, we conducted TUNEL assay and confirmed loss of functions of MMP-9 induced OS cell apoptosis. Next, we used lentivector packaging method to overexpress MMP-9 and found that overexpression of MMP-9 promoted OS cell migration. Fourthly, the results of luciferase assay showed that MMP-9 was targeted by hsa-miR-494, which inhibited OS. Fifthly, we revealed that the levels of hsa-miR-494 were upregulated by the drug silybin which inhibited OS. Finally, we revealed that silybin inhibited OS cell viability by altering the protein levels of ß-catenin and Runt-related transcription factor 2 (RUNX2) as determined by western blot and immunocytochemistry (ICC).

Renal Function Preservation in Surgical Resection of Primary Inferior Vena Cava Leiomyosarcoma Involving the Renal Veins.

OBJECTIVE: This retrospective study aimed to show the practice of preserving renal function during curative resection of inferior vena cava leiomyosarcoma (IVCL) involving the renal veins at a single institution over a 7 year period. MATERIALS AND METHODS: From February 2009 to February 2017, 10 patients (6 women; median age 49 years) with IVCL involving the renal veins were treated surgically at Peking Union Medical College Hospital. En bloc resections were performed in all patients, and the renal outflows were preserved in eight patients using a new method: venoplasty of the renal ostia (VRO). Data regarding patient details, pre-operative preparation, surgical procedures, post-operative recovery, and follow-up results were obtained and reviewed retrospectively. RESULTS: Computed tomography and intra-operative examinations revealed that renal vein confluences were involved but not invaded in all cases except Patient 4. All patients underwent curative en bloc tumour excision; a right nephrectomy was performed in only one patient (Patient 4) whose tumour invaded the right renal vein. The mean operation time was 358 min and the mean blood loss 1935 mL. At a median follow-up of 54.5 months, the 5 year local recurrence, distant metastasis, overall survival, and disease-free survival rates were 20%, 10%, 68.6%, and 38.1%, respectively. CONCLUSIONS: Venoplasty of the renal ostia is an effective method of preserving the renal veins and reconstructing renal outflow.

3,4-Methylenedioxymethamphetamine causes cytotoxicity on 661W cells through inducing macrophage polarization.

The abuse of 3,4-methylenedioxymethamphetamine (MDMA), a psychedelic drug, can lead to a variety of disorders in neural system, including the death of retinal neural cells. MDMA at lower doses does not cause obvious cytotoxicity to photoreceptor cells, indicating potential indirect mechanisms which have not yet been elucidated. This study investigated the effect of MDMA at nontoxic concentration on macrophage activation state and its resultant toxicity to photoreceptor cells. Using a co-culture system, cytotoxicity was caused by MDMA on 661W cells after co-culturing with RAW264.7 macrophage. Results showed that MDMA induced the macrophages to M1 polarization, releasing more pro-inflammatory cytokines, upregulating the M1-related gene and protein expression. The phenotype, secretion pattern, and cytotoxicity of the macrophages treated by MDMA are comparable to those of the ones stimulated by IFNγ and LPS. Our study demonstrated that MDMA promoted macrophage polarization to M1 and induced inflammatory response, providing the scientific rationale for the photoreceptor cell damage caused by the MDMA abuse.

[Interval-spaced Sessions of Partial Splenic Artery Embolization in Juvenile Patients with Hypersplenism].

Objective To determine whether interval-spaced sessions of partial splenic artery embolization(PSE) is a safe and effective alternative treatment for hypersplenism in juvenile patients. Methods Eight patients(3 males and 5 females) were included in this retrospective study.All patients were diagnosed as hypersplenism and underwent PSE in 2-3 sessions separated by 1-2 month intervals.Immediate,short,and long term follow-up were done.The effectiveness of the treatment was evaluated.Results No major postoperative complication was noted.No patient developed septic shock,splenic abscess,or spleen rupture.Postoperative pain and fever were common and manageable;only two patients developed loculated pleural effusions,which were well alleviated after conservative treatment.All patients showed significant increase in thrombocytes and white blood cells count after the first session of embolization.The cell counts became remarkable after the last session and remained at normal levels during the follow-up period.Conclusions PSE using 2-3 interval-spaced sessions can effectively decrease spleen size and reverse hypersplenism in juvenile patients.Also,it may reduce the postoperative complications commonly seen in traditional PSE.

Neuron-specific enolase, histopathological types, and age as risk factors for bone metastases in lung cancer.

Lung cancer is a malignant tumor with high metastatic ability and bone is the most common site of distant metastasis of it. However, the independent risk factors for bone metastases of lung cancer remain largely to be elucidated. Here, we conducted a retrospective study to evaluate the correlation between clinical-pathological parameters, serum levels of neuron-specific enolase and CYFRA21-1, and bone metastases in lung cancer patients. The results revealed that patients with bone metastases were younger than those without metastases. Adenocarcinoma was the most frequent type of histopathology in patients with bone metastases. And the incidence of bone metastasis in patients with adenocarcinoma was significantly higher than those with other histopathological subtypes ( p < 0.001). Furthermore, the serum concentration of neuron-specific enolase was significantly higher in patients with bone lesions than those without bone metastases. Multivariate logistic regression analysis showed that patients' age (odds ratio = 1.024, p < 0.001), concentrations of neuron-specific enolase (odds ratio = 1.212, p = 0.004), and histopathological types (odds ratio = 0.995, p = 0.001) were the independent risk factors for bone metastases in patients with lung cancer. Thus, physicians should pay attention to these factors in order to identify bone metastasis earlier while patient was primarily diagnosed as having lung cancer.

The effect of screw tunnels on the biomechanical stability of vertebral body after pedicle screws removal: a finite element analysis.

PURPOSE: Posterior reduction and pedicle screw fixation is a widely used procedure for thoracic and lumbar vertebrae fractures. Usually, the pedicle screws would be removed after the fracture healing and screw tunnels would be left. The aim of this study is to evaluate the effect of screw tunnels on the biomechanical stability of the lumbar vertebral body after pedicle screws removal by finite element analysis (FEA). METHODS: First, the CT values of the screw tunnels wall in the fractured vertebral bodies were measured in patients whose pedicle screws were removed, and they were then compared with the values of vertebral cortical bone. Second, an adult patient was included and the CT images of the lumbar spine were harvested. Three dimensional finite element models of the L1 vertebra with unilateral or bilateral screw tunnels were created based on the CT images. Different compressive loads were vertically acted on the models. The maximum loads which the models sustained and the distribution of the force in the different parts of the models were recorded and compared with each other. RESULTS: The CT values of the tunnels wall and vertebral cortical bone were 387.126±62.342 and 399.204±53.612, which were not statistically different (P=0.149). The models of three dimensional tetrahedral mesh finite element of normal lumbar 1 vertebra were established with good geometric similarity and realistic appearance. After given the compressive loads, the cortical bone was the first one to reach its ultimate stress. The maximum loads which the bilateral screw tunnels model, unilateral screw tunnel model, and normal vertebral model can sustain were 3.97 Mpa, 3.83 Mpa, and 3.78 Mpa, respectively. For the diameter of the screw tunnels, the model with a diameter of 6.5 mm could sustain the largest load. In addition, the stress distributing on the outside of the cortical bone gradually decreased as the thickness of the tunnel wall increased. CONCLUSIONS: Based on the FEA, pedicle screw tunnels would not decrease the biomechanical stability and strength of the vertebral body. A large diameter of screw tunnel and thick tunnel wall were helpful for the biomechanical stability of the vertebral body.

Incidence and risk factors for symptomatic spinal epidural haematoma following lumbar spinal surgery.

PURPOSE: Spinal epidural haematoma (SEH) is a common complication after lumbar spinal decompression surgery, and symptomatic SEH usually causes devastating neurological deficits. Although different risk factors for post-operative SEH have been reported, few studies focused on patients' laboratory tests. The purpose of this study was to analyze the incidence of symptomatic SEH following lumbar spinal surgery, as well as identify the risk factors for it. METHODS: Patients who underwent posterior lumbar spinal decompression surgery between January 2010 and August 2016 were included in this study and their medical records were retrospectively reviewed. Those who developed post-operative symptomatic SEH after the surgery were identified. The risk factors for SEH were analyzed by univariate and multivariate regression analysis. RESULTS: In total, 2715 patients were included in this study and 31 (1.14%) were identified with post-operative symptomatic SEH. Of these patients, 19 were males and 12 were females, with an average age of 59.39 ± 11.66 years. After multivariate logistic regression analysis, low serum calcium level (P = 0.025), blood type A (P = 0.04), increased estimated blood loss (P = 0.032), prolonged surgical duration (P = 0.018), and decreased post-operative globulin (P = 0.016) were identified as the independent risk factors for post-operative SEH following lumbar spinal surgery. Furthermore, prolonged surgical duration (odds ratio = 3.105) was the strongest risk factor for SEH. CONCLUSION: Based on a large population investigation, the incidence of symptomatic SEH following lumbar spinal decompression surgery was 1.14%. Blood type A, increased estimated blood loss, and prolonged surgical duration were identified as the independent risk factors for post-operative SEH while two new risk factors, including low serum calcium level and decreased post-operative globulin, were firstly identified in this study.

Prognostic performance of pre-treatment NLR and PLR in patients suffering from osteosarcoma.

BACKGROUND: Inflammatory response markers have been proposed to predict the clinical outcomes in various cancers. The aim of this study was to explore the influence of the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) on the prognosis of osteosarcoma. METHODS: Three hundred fifty-nine patients who underwent curative surgery for osteosarcoma were enrolled from 2005 to 2010. NLR and PLR were calculated from peripheral blood cell counts taken at pre-treatment. Optimal cutoff values of NLR and PLR were determined on the basis of receiver operating characteristic curve analysis. A predictive model was established to predict the clinical outcome for overall survival, and the predictive accuracy of this model was determined by concordance index (c-index). RESULTS: Our results showed that advanced stage and metastasis at diagnosis were significantly associated with the high NLR and PLR groups. NLR was an independent prognostic indicator for overall survival (HR = 1.80, 95% CI = 1.35-2.41, P < 0.001) and progression-free survival (HR = 1.65, 95% CI = 1.26-2.15, P < 0.001), except for PLR. The nomogram could perform well in the prediction of overall survival in patients with osteosarcoma (c-index 0.829). CONCLUSIONS: Our results suggest that both NLR and PLR can reflect clinical prognosis. NLR is more predictive of overall survival and progression-free survival than PLR.