A prediction nomogram for fractured vertebra re-collapse after posterior reduction and pedicle screw fixation in thoracolumbar fractures.

OBJECTIVE: This study aimed to establish a predictive nomogram model for re-collapse of fractured vertebra after posterior pedicle screw fixation in thoracolumbar fractures (TLFs). METHODS: Patients undergoing posterior pedicle screw fixation for TLFs at our hospital between January 2016 and December 2021 were retrospectively reviewed. Patients were divided into two groups according to the presence or absence of re-collapse of the fractured vertebra at the final follow-up. The predictors for fractured vertebra re-collapse were identified by univariate and multivariable logistic regression analysis, and a nomogram model was developed. The prediction performance and internal validation were established. RESULTS: A total of 224 patients were included in this study. Of these, 46 (20.5%) patients developed re-collapse of fractured vertebra. Age, thoracic and lumbar injury severity score (TLICS), screw distribution in the fractured vertebra, and anterior vertebral height compression (AVHC) ratio were associated with vertebral re-collapse. These predictors were used to construct a predictive nomogram. The area under the receiver operating characteristic curve (AUC) of the nomogram model was 0.891. The concordance index (C-index) was 0.891, and it was 0.877 with bootstrapping validation. The calibration curves and decision curve analysis (DCA)also suggested that the nomogram model had excellent predictive performances for fractured vertebra re-collapse. CONCLUSIONS: A clinical nomogram incorporating four variables was constructed to predict fractured vertebra re-collapse after posterior pedicle screw fixation for TLFs. The nomogram demonstrated good calibration and discriminative abilities, which may help clinicians to make better treatment decisions.

Caffeic acid modulates activation of neutrophils and attenuates sepsis-induced organ injury by inhibiting 5-LOX/LTB4 pathway.

BACKGROUND: Sepsis is a critical systemic inflammatory syndrome which usually leads to multiple organ dysfunction. Caffeic acid (CA), a phenolic compound derived from various plants, has been proved to be essential in neuroprotection, but its role in septic organ damage is unclear. This research aimed to investigate whether CA protects against organ injury in a mouse model of cecal ligation and puncture (CLP). METHODS: CA (30 mg/kg) or vehicle was administered by intraperitoneal injection immediately after CLP. The samples of blood, lungs, and livers were collected 24 h later. Organ injury was assessed by histopathological examination (HE staining), neutrophil infiltration (myeloperoxidase fluorescence), oxidative stress levels (MDA, SOD, HO-1), and inflammatory cytokines (TNF-α, IL-1ß, and IL-6) release in lung and liver tissues. Neutrophil extracellular trap (NET) formation was analyzed by immunofluorescence. In vitro experiments were performed to investigate the potential mechanisms of CA using small interfering RNA (siRNA) techniques in neutrophils, and the effect of CA on neutrophil apoptosis was analyzed by flow cytometry. RESULTS: Results showed that CA treatment improved the 7-day survival rate and attenuated the histopathological injury in the lung and liver of CLP mice. CA significantly reduced neutrophil infiltration in the lungs and livers of CLP mice. TNF-α, IL-1ß, IL-6 and LTB4 were reduced in serum, lung, and liver of CA-treated CLP mice, and phosphorylation of MAPK (p38, ERK, JNK) and p65 NF-κB was inhibited in lungs and livers. CA treatment further increased HO-1 levels and enhanced superoxide dismutase (SOD) activity, but reduced malondialdehyde (MDA) levels and NET formation. Similarly, in vitro experiments showed that CA treatment and 5-LOX siRNA interference inhibited inflammatory activation and NET release in neutrophils, suppressed MAPK and NF-κB phosphorylation in LPS-treated neutrophils, and decreased LTB4 and cfDNA levels. Flow cytometric analysis revealed that CA treatment reversed LPS-mediated delayed apoptosis in human neutrophils, and Western blot also indicated that CA treatment inhibited Bcl-2 expression but increased Bax expression. CA treatment did not induce further changes in neutrophil apoptosis, inflammatory activation, and NET release when 5-LOX was knocked down by siRNA interference. CONCLUSIONS: CA has a protective effect on lung and liver injury in a murine model of sepsis, which may be related to inhibition of the 5-LOX/LTB4 pathway.

Sparganosis of a thoracic vertebra misdiagnosed as bone metastasis from lung cancer.

Sparganosis is a rare parasitic infection caused by plerocercoid tapeworm larvae. We described a case of a 27-year-old man presenting with numbness in both legs and masses in the right lung and spine, initially thought to have spinal metastasis from lung cancer. However, after pathological and parasitological examinations, the patient was found to have spinal sparganosis, likely due to a history of consuming raw frogs. The patient was successfully treated with praziquantel, resulting in the recovery of muscle strength in his legs. This case highlights the importance of considering spinal sparganosis as a differential diagnosis in patients with spinal masses, especially those with a history of consuming raw or undercooked frogs. Accurate diagnosis and early treatment are crucial for managing this infection.

Risk Factors and Nomogram for Postoperative Pulmonary Infection in Patients with Cervical Spinal Cord Injury.

OBJECTIVE: To identify the risk factors for developing postoperative pulmonary infection in patients with acute cervical spinal cord injury (CSCI), and to develop a nomogram prediction model. METHODS: Patients with CSCI who were admitted to 3 different medical centers between July 2011 and July 2021 were included in this study. All patients underwent cervical spine surgery. Data for patients admitted to the first 2 centers were included in a training set to establish the nomogram prediction model, and data for patients admitted to the third center were included in a validation set to externally verify the efficacy of the prediction model. For the training set, patients were divided into an infected group and a noninfected group (control group). Independent risk factors for postoperative pulmonary infection in patients with CSCI were identified by univariate and multivariate logistic regression analyses. Additionally, a nomogram prediction model was developed and validated based on the risk factors. RESULTS: A total of 689 patients were enrolled, including 574 for the training set and 115 for the validation set. Of the patients included for the training set, 144 developed pulmonary infection, with an incidence of 25.09%; 40 patients included for the validation set developed pulmonary infection (34.78%). Multivariate logistic regression analysis showed that age, American Spinal Injury Association grade, steroid pulse, high-level injury, smoking, multistage surgery, and operation duration were risk factors for the development of postoperative pulmonary infection in patients with CSCI. The area under the curve of the receiver operating characteristic curve of the model built by the training set was 0.905, and that of the receiver operating characteristic curve of the verification set was 0.917. The decision curve indicated that the model was in the range 1%-100%, and the predicted net benefit value of the model was high. CONCLUSIONS: Age, American Spinal Injury Association grade, steroid pulse, CSCI site, smoking history, number of surgical levels, and surgical duration are correlated with the development of postoperative pulmonary infection in patients with CSCI. The risk prediction model of postoperative pulmonary infection has a good prediction efficiency and accuracy.

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.

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.

Clinical outcomes and prediction nomogram model for postoperative hemoglobin < 80 g/L in patients following primary lumbar interbody fusion surgery.

OBJECTIVE: To analyze the association between different postoperative hemoglobin (Hb) levels and postoperative outcomes in patients who have undergone primary lumbar interbody fusion, and to investigate the risk factors and establish a predictive nomogram mode for postoperative Hb < 80 g/L. METHODS: We retrospectively analyzed 726 cases who underwent primary lumbar interbody fusion surgery between January 2018 and December 2021in our hospital. All patients were divided into three groups according to the postoperative Hb levels (< 70 g/L, 70-79 g/L, ≥ 80 g/L). The postoperative outcomes among the three groups were compared, and the risk factors for postoperative Hb < 80 g/L were identified by univariate and multivariable logistic regression analysis. Based on these independent predictors, a nomogram model was developed. Predictive discriminative and accuracy ability of the predicting model was assessed using the concordance index (C-index) and calibration plot. Clinical application was validated using decision curve analysis. Internal validation was performed using the bootstrapping validation. RESULTS: Patients with postoperative Hb < 80 g/L had higher rates of postoperative blood transfusion, a greater length of stay, higher rates of wound complications, and higher hospitalization costs than those with postoperative Hb ≥ 80 g/L. Preoperative Hb, preoperative platelets, fusion segments, body mass index, operation time, and intraoperative blood loss independently were associated with postoperative Hb < 80 g/L. Intraoperative blood salvage was found to be a negative predictor for postoperative Hb < 80 g/L (OR, 0.21 [95% CI 0.09-0.50]). The area under the curve of the nomogram model was 0.950. After internal validations, the C-index of the model was 0.939. The DCA and calibration curve suggested that the nomogram model had a good consistency and clinical utility. CONCLUSIONS: Postoperative Hb < 80 g/L in patients following primary lumbar interbody fusion surgery increased blood transfusions requirement and was independently associated with poor outcomes. A novel nomogram model was established and could conveniently predict the risk of postoperative Hb < 80 g/L in patients after this type of surgery.

Effects of phyllotaxy on variation and inner relationships of leaflet traits in compound-leaved plants.

To understand the distribution pattern of leaflet traits in compound-leaved along with phyllotaxy, we selected three compound-leaved trees with opposite phyllotaxy in Xiaoxing' an Mountains, Fraxinus mandshurica, Phellodendron amurense, Juglans mandshurica, as the research objects. We measured leaf thickness, leaf area, specific leaf area, leaf dry matter content, palisade tissue thickness, spongy tissue thickness, ratio of palisade tissue thickness to spongy tissue thickness, and carbon content, nitrogen content, phosphorus content of leaflets at different phyllotaxy positions. We analyzed the variation of leaflet traits with phyllotaxy and the influence of phyllotaxy on the inner relationships between leaflet traits. The results showed that the variation of leaflet area, leaflet dry matter content, spongy tissue thickness and ratio of palisade tissue thickness to spongy tissue thickness with the increase of phyllotaxy were mainly divided into three types: increase, decrease, first increase and then decrease. Leaflet thickness, specific leaflet area, palisade tissue thickness, as well as nutrient contents did not change with phyllotaxy. Within compound leaves of three species, the variation coefficients and plasticity index of leaflet thickness, leaflet area, specific leaflet area, leaflet dry matter content, palisade tissue thickness, spongy tissue thickness, ratio of palisade tissue thickness to spongy tissue thickness ranged from 6.1% to 28.6% and from 0.14 to 0.70, respectively. Phyllotaxy had a significant effect on the bivariate correlation between leaflet traits. Specific leaflet area and leaflet dry natter content were negatively correlated in different phyllotaxy positions of F. mandshurica and J. mandshurica. Leaflet nitrogen content and phosphorus content showed a positive correlation in different phyllotaxy positions of F. mandshurica and P. amurense. The first and secondary leaflets (the first leaflets farthest from the base of the petiole) of J. mandshurica showed a conservative strategy, while the seventh and eighth leaflets showed an acquisition strategy. Leaflets of F. mandshurica and P. amurense did not show different ecological strategies.

Trend of unplanned reoperation rates after lumbar degenerative surgery from 2011 to 2019: a large patient population study.

BACKGROUND: Unplanned reoperation is commonly performed due to postoperative complications. Previous studies have reported the incidence of unplanned reoperation following lumbar spinal surgery. But few study focused on the trend of reoperation rates, and the reasons of unplanned reoperation were not clear. In this study, we conducted a retrospective study to determine the trend of unplanned reoperation rates after degenerative lumbar spinal surgery from 2011 to 2019, and the reasons and risk factors of unplanned reoperation were also determined. METHODS: Data of patients who were diagnosed with degenerative lumbar spinal disease and underwent posterior lumbar spinal fusion surgery in our institution from January 2011 to December 2019 were reviewed. Those who received unplanned reoperation during the primary admission were identified. The demographics, diagnosis, surgical segments and postoperative complications of these patients were recorded. The rates of unplanned reoperation from 2011 to 2019 were calculated, and the reasons of unplanned reoperation were statistically analysed. RESULTS: A total of 5289 patients were reviewed. Of them, 1.91% (n = 101) received unplanned reoperation during the primary admission. The unplanned reoperation rates of degenerative lumbar spinal surgery firstly increased from 2011 to 2014, with a peak rate in 2014 (2.53%). Then, the rates decreased from 2014 to 2019, with the lowest one in 2019 (1.46%). Patients with lumbar spinal stenosis have a higher rate of unplanned reoperation (2.67%) compared with those diagnosed as lumbar disc herniation (1.50%) and lumbar spondylolisthesis (2.04%) (P < 0.05). The main reasons for unplanned reoperation were wound infection (42.57%), followed by wound hematoma (23.76%). Patients who underwent 2-segment spinal surgery had a higher unplanned reoperation rate (3.79%) than those receiving other segments surgery (P < 0.001). And different spine surgeons had different reoperation rates. CONCLUSIONS: The rates of unplanned reoperation after lumbar degenerative surgery increased at first and then decreased during past 9 years. Wound infection was the major reason for unplanned reoperation. 2-segment surgery and surgeon's surgical skills were related to the reoperation rate.

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.

A practical dynamic nomogram model for predicting bone metastasis in patients with thyroid cancer.

Purpose: The aim of this study was to established a dynamic nomogram for assessing the risk of bone metastasis in patients with thyroid cancer (TC) and assist physicians to make accurate clinical decisions. Methods: The clinical data of patients with TC admitted to the First Affiliated hospital of Nanchang University from January 2006 to November 2016 were included in this study. Demographic and clinicopathological parameters of all patients at primary diagnosis were analyzed. Univariate and multivariate logistic regression analysis was applied to build a predictive model incorporating parameters. The discrimination, calibration, and clinical usefulness of the nomogram were evaluated using the C-index, ROC curve, calibration plot, and decision curve analysis. Internal validation was evaluated using the bootstrapping method. Results: A total of 565 patients were enrolled in this study, of whom 25 (4.21%) developed bone metastases. Based on logistic regression analysis, age (OR=1.040, P=0.019), hemoglobin (HB) (OR=0.947, P<0.001) and alkaline phosphatase (ALP) (OR=1.006, P=0.002) levels were used to construct the nomogram. The model exhibited good discrimination, with a C-index of 0.825 and good calibration. A C-index value of 0.815 was achieved on interval validation analysis. Decision curve analysis showed that the nomogram was clinically useful when intervention was decided at a bone metastases possibility threshold of 1%. Conclusions: This dynamic nomogram, with relatively good accuracy, incorporating age, HB, and ALP, could be conveniently used to facilitate the prediction of bone metastasis risk in patients with TC.

The mechanism of VCP-mediated metastasis of osteosarcoma based on cell autophagy and the EMT pathway

Objective Study of the molecular mechanisms of metastasis is still the research focus for osteosarcoma (OS) prevention. This study investigates the mechanism of valosin-containing protein (VCP) promoting OS metastasis in vitro through autophagy and epithelial–mesenchymal transition (EMT). Methods Different cell lines of osteosarcoma (143B and MG63) were adopted in this study. The level of VCP expression in osteosarcoma cells was changed, and the level of autophagy and the progression of the epithelial–mesenchymal transition (EMT) were observed. Then autophagy and EMT in OS cells were changed artificially, and proliferation and migration ability were observed. Results The expression of LC3II/I was decreased, but the insolubilized P62 protein expression was increased in the VCP inhibiting group and the autophagy inhibitor treatment group. Simultaneously, E-cadherin protein expression increased while N-cadherin protein expression decreased in the VCP inhibiting group but increased in the TGF-β1 treatment group. In addition, suppressing VCP can cause a decrease in Transforming Growth Factor β1 (TGF-β1), smad2, smad3, phosphorylated smad2 (p-smad2), and phosphorylated smad3 (p-smad3). Autophagy inhibitors and agonists have no significant effect on the migration and invasion of OS cells but can significantly affect the ability of cells to resist anoikis. EMT inhibitors and agonists have a proportional effect on the migration and invasion of OS cells. Conclusion VCP is likely to promote the migration and invasion of OS cells by inducing EMT, possibly via TGF-β1/smad2/3 signaling pathway. In this process, VCP-mediated autophagy may contribute to successful distant metastasis of tumor cells indirectly (AU)

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.

Automated machine learning-based model for the prediction of delirium in patients after surgery for degenerative spinal disease.

OBJECTIVE: This study used machine learning algorithms to identify critical variables and predict postoperative delirium (POD) in patients with degenerative spinal disease. METHODS: We included 663 patients who underwent surgery for degenerative spinal disease and received general anesthesia. The LASSO method was used to screen essential features associated with POD. Clinical characteristics, preoperative laboratory parameters, and intraoperative variables were reviewed and were used to construct nine machine learning models including a training set and validation set (80% of participants), and were then evaluated in the rest of the study sample (20% of participants). The area under the receiver-operating characteristic curve (AUROC) and Brier scores were used to compare the prediction performances of different models. The eXtreme Gradient Boosting algorithms (XGBOOST) model was used to predict POD. The SHapley Additive exPlanations (SHAP) package was used to interpret the XGBOOST model. Data of 49 patients were prospectively collected for model validation. RESULTS: The XGBOOST model outperformed the other classifier models in the training set (area under the curve [AUC]: 92.8%, 95% confidence interval [CI]: 90.7%-95.0%), validation set (AUC: 87.0%, 95% CI: 80.7%-93.3%). This model also achieved the lowest Brier Score. Twelve vital variables, including age, serum albumin, the admission-to-surgery time interval, C-reactive protein level, hypertension, intraoperative blood loss, intraoperative minimum blood pressure, cardiovascular-cerebrovascular disease, smoking, alcohol consumption, pulmonary disease, and admission-intraoperative maximum blood pressure difference, were selected. The XGBOOST model performed well in the prospective cohort (accuracy: 85.71%). CONCLUSION: A machine learning model and a web predictor for delirium after surgery for the degenerative spinal disease were successfully developed to demonstrate the extent of POD risk during the perioperative period, which could guide appropriate preventive measures for high-risk patients.

The mechanism of VCP-mediated metastasis of osteosarcoma based on cell autophagy and the EMT pathway.

OBJECTIVE: Study of the molecular mechanisms of metastasis is still the research focus for osteosarcoma (OS) prevention. This study investigates the mechanism of valosin-containing protein (VCP) promoting OS metastasis in vitro through autophagy and epithelial-mesenchymal transition (EMT). METHODS: Different cell lines of osteosarcoma (143B and MG63) were adopted in this study. The level of VCP expression in osteosarcoma cells was changed, and the level of autophagy and the progression of the epithelial-mesenchymal transition (EMT) were observed. Then autophagy and EMT in OS cells were changed artificially, and proliferation and migration ability were observed. RESULTS: The expression of LC3II/I was decreased, but the insolubilized P62 protein expression was increased in the VCP inhibiting group and the autophagy inhibitor treatment group. Simultaneously, E-cadherin protein expression increased while N-cadherin protein expression decreased in the VCP inhibiting group but increased in the TGF-ß1 treatment group. In addition, suppressing VCP can cause a decrease in Transforming Growth Factor ß1 (TGF-ß1), smad2, smad3, phosphorylated smad2 (p-smad2), and phosphorylated smad3 (p-smad3). Autophagy inhibitors and agonists have no significant effect on the migration and invasion of OS cells but can significantly affect the ability of cells to resist anoikis. EMT inhibitors and agonists have a proportional effect on the migration and invasion of OS cells. CONCLUSION: VCP is likely to promote the migration and invasion of OS cells by inducing EMT, possibly via TGF-ß1/smad2/3 signaling pathway. In this process, VCP-mediated autophagy may contribute to successful distant metastasis of tumor cells indirectly.

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.

Soil water content and nitrogen differentially correlate with multidimensional leaf traits of two temperate broadleaf species.

The variation and correlation of leaf economics and vein traits are crucial for predicting plant ecological strategies under different environmental changes. However, correlations between these two suites of traits and abiotic factors such as soil water and nitrogen content remain ambiguous. We measured leaf economics and vein traits as well as soil water and nitrogen content for two different shade-tolerant species (Betula platyphylla and Acer mono) in four mixed broadleaved-Korean pine (Pinus koraiensis) forests along a latitudinal gradient in Northeast China. We found that leaf economics traits and vein traits were decoupled in shade-intolerant species, Betula platphylla, but significantly coupled in a shade-tolerant species, A. mono. We found stronger correlations among leaf traits in the shade tolerant species than in the shade intolerant species. Furthermore, leaf economic traits were positively correlated with the soil water gradient for both species, whereas vein traits were positively correlated with soil water gradient for the shade intolerant species but negatively correlated in the shade tolerant species. Although economic traits were positively correlated with soil nitrogen gradient in shade intolerant species but not correlated in shade tolerant species, vein traits were negatively correlated with soil nitrogen gradient in shade tolerant species but not correlated in shade intolerant species. Our study provides evidence for distinct correlations between leaf economics and vein traits and local abiotic factors of species differing in light demands. We recommend that the ecological significance of shade tolerance be considered for species when evaluating ecosystem functions and predicting plant responses to environmental changes.

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.

Effect of screw tunnels on proximal femur strength after screw removal: A finite element analysis.

BACKGROUND: The presence of screw tunnels in the femoral neck is a problem for patients with proximal femoral fractures after removal of internal fixation. The question of how much does the existence of the screw tunnels affect the strength of the femur and whether the patient needs to be protected with an adjunctive device has been controversial. The objective of this finite element analysis was to determine (1) whether the screw tunnels affects normal weight bearing after removal of internal fixation of a proximal femur fracture, (2) which screw tunnels parameters affect the weight bearing capacity of the entire femur. HYPOTHESIS: The presence of the screw tunnels reduces the load-bearing capacity of the femur, and the arrangement, diameter and wall thickness of the screw tunnels affect the load-bearing capacity of the femur. MATERIALS AND METHODS: Twenty patients who underwent surgical treatment for proximal femur fracture at our hospital were included in the study. Computed tomography (CT) values of the screw tunnel wall in the femur after removal of internal fixations were analysed. Mimics v16.0 and Hypermesh v13.0 software programs were used to generate 3-dimensional (3D) tetrahedral finite element models of the proximal femur with different screw tunnel numbers, diameters, thicknesses, and arrangements. An acetabulum exerting a vertical pressure load of 600N on the femoral head was simulated and the force on various parts of the femur in each model was calculated. RESULTS: There was no difference in the Hounsfield Units of the tunnel walls and cortical bone of the proximal femur (893.48±61.28 vs. 926.34±58.43; p=0.091). In each of the 3D models, the cancellous bone was the first structure to reach maximal stress. The compressive strength of the femur decreased with increasing thickness of the screw tunnel wall and decreased with increasing tunnel diameter. The femoral neck model with the inverted triangle screw tunnel arrangement had the highest compressive strength. DISCUSSION: The femoral neck with screw tunnels can withstand day-to-day stress without special intervention. For femoral neck fractures fixed with cannulated screws, inverted triangle screws are recommended; For a single screw tunnel in the femoral neck, the larger the diameter of the femoral neck internal screw channel, the weaker the load-bearing capacity of the femur. LEVEL OF EVIDENCE: III; well-designed computational non-experimental study.