BACKGROUND:Anterior subtotal corpectomy,decompression and fusion is a conventional method to treat cervical degenerative diseases.A titanium cage is an important implant to maintain the stability of the cervical spine after subtotal corpectomy.In recent years,many patients have complications such as titanium cage sinking,which are highly controversial. OBJECTIVE:To investigate the internal biomechanical relationship between the tilt angle of the titanium cage and postoperative titanium cage subsidence after anterior subtotal cervical corpectomy,decompression and fusion. METHODS:A three-dimensional finite element model of the C4-C6 segment was established by CT images of a normal human cervical spine,in which the anterior subtotal resection,decompression and fusion of the C5 vertebral body were simulated,and titanium cages with different tilt angles(-6° to-1° negative angle,that is,the front edge of titanium cage is shorter than the rear edge of titanium cage;1° to 6° positive angle,that is,the front edge of titanium cage is longer than the rear edge of titanium cage)were placed.After setting the boundary conditions,preloads of 50,100 and 150 N were applied respectively on the C4 vertebral body.The stress value of each contact point between the titanium cage and C4 lower-end plate and C6 lower-end plate(seven stress contact points on the contact surface of titanium mesh)was recorded and statistical analysis was conducted. RESULTS AND CONCLUSION:(1)The tilt angles of the titanium cage of the positive angle group and negative angle group under 50,100 and 150 N stress respectively were found by Mann Whitn test,with P<0.05,which was statistically significant.The dispersion coefficients of the positive angle group were smaller than those of the negative angle group under 50,100 and 150 N stress conditions.(2)Under 50,100 and 150 N stress conditions,the Wilcoxon sign rank test in the positive angle group of titanium cage tilt angle found that when the angle was set to 1° to 5°,the difference was not statistically significant(P>0.05).However,when the tilt angle of the titanium cage was set to 6°,the difference was statistically significant(P<0.05).(3)Under 50,100 and 150 N stress conditions,the Wilcoxon sign rank test in the negative angle group of titanium cage tilt angle found that when the tilt angle was set to-1° to-6°,the difference was not statistically significant(P>0.05).(4)It is concluded that in the sagittal position,the titanium cage with a positive tilt angle is more stable than with a negative tilt angle,which is more suitable for clinical use.The tilt angle of the titanium cage is relatively stable in the range of 1° to 5°.When the tilt angle is 6°,the stability starts to decline,which is easy to cause complications of titanium cage sinking after surgery.It is more suitable to select the titanium cage with a tilt angle of 1° to 5° according to the clinical situation during surgery to improve the efficacy.

BACKGROUND:Cervical spondylotic myelopathy is a progressive disease leading to dysfunction in the middle-aged and elderly,and early diagnosis is difficult.In recent years,some clinical scholars have found that dynamic magnetic resonance imaging technology can detect spinal cord compression in a dynamic position earlier,but its specific biomechanical mechanism needs to be clarified. OBJECTIVE:To investigate the biomechanical compression characteristics of early cervical spondylotic myelopathy in hyperextension and flexion position,and to verify the effectiveness of dynamic magnetic resonance imaging in the diagnosis of early cervical spondylotic myelopathy. METHODS:A retrospective analysis was made on the patients who underwent cervical dynamic magnetic resonance imaging in the Department of Orthopedics of First Affiliated Hospital of Guangxi University of Chinese Medicine from January to June 2022.16 subjects were selected and divided into two groups.The pathological group included 8 patients with early cervical spondylotic myelopathy with hypertrophy of ligamentum flavum as the main sign,with 5 male patients and 3 female patients.The normal group included 8 normal degenerative people,with 4 male patients and 4 female patients.All patients were photographed with cervical CT plain scan,magnetic resonance imaging plain scan,and dynamic magnetic resonance imaging plain scan.This study was divided into the following three parts:(1)collect the dynamic magnetic resonance imaging image DCOM data of two groups of subjects,and collect the cervical vertebra CT and neutral magnetic resonance imaging image DCOM data to understand the bone and soft tissue of the two groups of subjects in the neutral position.(2)Based on the DCOM data of magnetic resonance imaging and CT plain scan,the three-dimensional finite element models of lower cervical vertebra(C3-7)of normal degenerative population and early cervical spondylotic myelopathy patients were established by reverse engineering software.The equivalent stress and equivalent elastic strain of the spinal cord and posterior dura were analyzed,and the distribution of stress and strain was observed.(3)After obtaining the stress and strain data,the data between groups were compared to analyze the mechanical characteristics of spinal cord compression caused by early cervical spondylotic myelopathy in a dynamic position and to verify the effectiveness of dynamic magnetic resonance imaging in the diagnosis of early cervical spondylotic myelopathy. RESULTS AND CONCLUSION:(1)When simulating the posterior extension,flexion and neutral position of the lower cervical vertebrae(C3-7)in the two groups,the values of stress and strain in the posterior part of the spinal cord were in the following order:extension>flexion>neutral(P<0.05).The strain values from large to small were as follows:extension>flexion>neutral(P<0.05).(2)Compared with the normal degenerative population model,the equivalent stress and strain of the spinal cord in the pathological group were higher than those in the normal group under two degrees of freedom of flexion and extension(P<0.05).The distribution area of stress and strain in the posterior part of the spinal cord was irregular.(3)In the neutral position,there was no significant difference in the strain value of the spinal cord between the two groups(P>0.05),and the strain distribution was uniform and regular.(4)It is indicated that in the cervical extension position,the dural sac and the posterior part of the spinal cord were compressed and deformed in the early cervical spondylotic myelopathy patients with the hypertrophy of ligamentum flavum as the main sign,and the degree of compression deformation of the spinal cord was significantly higher than that in the anterior flexion position and neutral position.In the neutral position,there were no obvious signs of spinal cord deformation in patients with early cervical spondylotic myelopathy.This study verified the role of dynamic magnetic resonance imaging in the diagnosis of early cervical spondylotic myelopathy from the point of view of biomechanics.

Objective To explore the biomechanical mechanism of pseudoaneurysm formation at the anastomotic site of vascular patch and the inhibitory effect of transforming growth factor(TGF β1)hydrogel on aneurysm.Methods The vascular patch model and the pseudoaneurysm model were constructed separately,and the two-way fluid-structure interaction method was used to numerically simulate the blood-vessel wall dynamic response at the anastomosis.Based on the analysis of mechanical parameters such as postoperative blood velocity,vessel wall shear stress and aneurysm wall displacement,the mechanisms of postoperative pseudoaneurysm formation and inhibition were studied.Results The numerical simulation results showed that the wall shear stress increased when the blood flowed through the front end of the patch.When the pseudoaneurysm has been formed after surgery,the aneurysm wall became significantly thicker following the injection of TGF β1 hydrogel into the aneurysmal wall,and the intratumoral shear stress and the aneurysmal wall displacement were decreased.Conclusion Pseudoaneurysms are easy to form at the front end of the anastomosis after surgery,and the injection of TGF β1 hydrogel into the aneurysm wall can effectively inhibit the formation and progression of pseudoaneurysm.The numerical simulation study provides a numerical basis for the mechanical mechanism study of the formation and progression of pseudoaneurysm after patch angioplasty.

Background Mitochondrial dynamin-related protein 1 (DRP1) regulates mitochondrial division and plays an important role in maintaining hepatocyte function. However, the role of DRP1 in cadmium exposure-induced maternal liver damage in pregnant mice remains unclear. Objective To investigate the role and mechanism of DRP1 in maternal liver damage induced by cadmium exposure during pregnancy. Methods This study consisted of animal experiments and cell experiments. (1) Animal experiments. Mice at 14 days of gestation were randomly divided into three groups: a control group, a low-dose cadmium group (LCd group: 2.5 mg·kg⁻¹), and a high-dose cadmium group (HCd group: 5 mg·kg⁻¹). The pregnant mice were intraperitoneally injected with cadmium chloride (CdCl₂) for 6 and 24 h in the next morning. The weights of pregnant mice, uterus, maternal liver, and fetal mice were recorded after sacrifice. Serum and liver of pregnant mice were collected, the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum were detected, and liver tissues were stained with HE to observe changes in liver function and liver tissue structure. The expressions of oxidative phosphorylation-related proteins, hypoxia inducible factor-1α (HIF-1α) and DRP1 proteins in liver of pregnant mice were detected by Western blotting. (2) Cell experiments. AML12 cells were treated with CdCl₂ (10 μmol·L⁻¹) for 0, 2, 6, 12, and 24 h. The expressions of oxidative phosphorylation-related proteins, DRP1, and hypoxia inducible factor-1α (HIF-1α) proteins were detected. AML12 cells were pretreated with DRP1 inhibitor Mdivi-1 for 1 h and then CdCl₂ (10 μmol·L⁻¹) for 12 h to detect the expression of oxidative phosphorylation-related proteins and DRP1 protein. AML12 cells were treated with Hif-1α siRNA for 48 h and CdCl₂ (10 μmol·L⁻¹) for 6 h to detect the expression of HIF-1α and DRP1 proteins. Results The results of animal experiments showed that cadmium exposure in pregnant mice had no effects on maternal liver weight and liver coefficient. However, the histomorphological changes and necrosis in hepatocytes were observed. Compared with the control group, the serum ALT and AST levels of pregnant mice in the LCd group were significantly increased after 6 h (P＜0.05), and the levels in the HCd group were significantly increased after 6 and 24 h (P＜0.05). Cadmium exposure during pregnancy significantly up-regulated HIF-1α and DRP1 expressions and down-regulated the expressions of oxidative phosphorylation-related proteins in maternal livers. In vitro cell experiments showed that the expressions of oxidative phosphorylation-related proteins was significantly decreased and HIF-1α and DRP1 protein expressions were significantly increased in the AML12 cells treated with CdCl₂ for 6 h. Mdivi-1 pretreatment significantly antagonized the inhibitory effect of cadmium on the expressions of oxidative phosphorylation-related proteins in AML12 cells, while Hif-1α siRNA pretreatment significantly antagonized the up-regulative effect of cadmium on DRP1 expression in AML12 cells. Conclusion Cadmium exposure in pregnant mice may up-regulate DRP1 expression by activating HIF-1α signaling, then inhibit oxidative phosphorylation level of hepatic cells, and ultimately lead to maternal liver damage.

Objective:To investigate the surgical techniques and advantages of Ti-Robot-assisted surgery for pelvic fragility fractures in the elderly.Methods:A retrospective review was performed on geriatric patients presenting with pelvic fractures at the Orthopedics Department of Trauma, China-Japan Union Hospital of Jilin University from September 2019 to December 2022. Minimally invasive procedures were executed with the assistance of the Ti-Robot, and the therapeutic outcomes were appraised. The cohort comprised 24 patients aged ≥60 years, consisting of 6 men and 18 women, with a mean age of 66.1±4.9 years (range, 60-77 years). Fourteen patients sustained high-energy trauma, while 10 encountered low-energy trauma. Fracture classification utilized the FFP system proposed by Rommens and Hofmann. The cohort included 20 patients with FFP II fractures (5 males, 15 females; 4 of type IIa, 12 of type IIb, and 4 of type IIc) and 4 patients with FFP III fractures (1 male, 3 females; all type IIIa). The Matta standard assessment scale gauged fracture reduction, while the Gras classification, with Ti-Robot assistance, assessed screw positioning. Postoperative functionality was holistically assessed based on the Majeed quantitative evaluation system, focusing on pain intensity, sitting, standing, walking, and daily activities. The visual analogue scale (VAS) gauged pain levels in patients with type II fractures, pre and 72 hours post-surgery.Results:According to the Matta standard assessment scale, postoperative fracture reduction quality in 24 elderly patients showed 18 as excellent, 4 as good, and 2 as fair, yielding a 92% (22/24) combined excellent and good rate. Based on the Gras classification, 52 screws were rated as excellent and 7 as good, achieving a 100% positive rate. Utilizing Majeed's modified pelvic fracture evaluation system, postoperative functional recuperation revealed 19 patients as excellent and 5 as good. There were no reports of severe internal disease exacerbations, neurological manifestations, infections, or intraoperative extensive hemorrhaging, with all patients remaining stable. Fractures exhibited robust healing during follow-ups, averaging a recovery time of 3.5±0.7 months (range, 3-5 months). The VAS for 20 patients with FFP type II fractures decreased from 6.3±2.0 pre-surgery to 4.1±1.4 post-surgery ( t=6.14, P=0.003), signifying substantial pain mitigation. Conclusion:In the elderly with pelvic fragility fractures, particularly type II, securing with channel screws is viable. The Ti-Robot-assisted minimally invasive approach is advocated due to its potential to diminish surgical risks and expedite postoperative recuperation.

We have discovered and synthesized a series of indole-based derivatives as novel sigma-2 (σ ₂) receptor ligands. Two ligands with high σ ₂ receptor affinity and subtype selectivity were then radiolabeled with F-18 in good radiochemical yields and purities, and evaluated in rodents. In biodistribution studies in male ICR mice, radioligand [¹⁸F]9, or 1-(4-(5,6-dimethoxyisoindolin-2-yl)butyl)-4-(2-[¹⁸F]fluoroethoxy)-1H-indole, was found to display high brain uptake and high brain-to-blood ratio. Pretreatment of animals with the selective σ ₂ receptor ligand CM398 led to significant reductions in both brain uptake (29%-54%) and brain-to-blood ratio (60%-88%) of the radioligand in a dose-dependent manner, indicating high and saturable specific binding of [¹⁸F]9 to σ ₂ receptors in the brain. Further, ex vivo autoradiography in male ICR mice demonstrated regionally heterogeneous specific binding of [¹⁸F]9 in the brain that is consistent with the distribution pattern of σ ₂ receptors. Dynamic positron emission tomography imaging confirmed regionally distinct distribution and high levels of specific binding for [¹⁸F]9 in the rat brain, along with appropriate tissue kinetics. Taken together, results from our current study indicated the novel radioligand [¹⁸F]9 as the first highly specific and promising imaging agent for σ ₂ receptors in the brain.

Radiogenomics aims at investigating the relationship between radiomics features and genomic features, which has certain practical value in the individualized molecular targeted therapy. Meanwhile, it is noninvasive, repeatable and inexpensive. In recent years, a large number of studies have shown that radiomics features have certain predictive values for the mutation status of driver genes of lung cancer. The application of radiogenomics is insufficient at present, but with its continuous improvement and development, it will play an increasingly important role in the precise therapy of lung cancer in the future.

Objective To develop a time-resolved fluorescent microspheres immunochromatographic assay (TRFMIA) for detection of alphafetoprotein (AFP) and carcinoembryonic antigen (CEA) in human serum and to evaluate its performance.Methods The Eu-time-resolved fluorescent polystyrene particles conjugated with monoclonal antibody AC18# for AFP and AE03# for CEA were used as fluorescent labels.The monoclonal antibody AC17# for AFP,AE05# for CEA and goat anti-rabbit antibody were immobilized on the nitrocellulose membrane as the test lines and control line.Several performances indicators were measured,including linear range,detection limit,and specificity.AFP and CEA were measured by the new method and the results were compared with those obtained by time-resolved fluoroimmunoassay (TRFIA) and electro-chemiluminescence immunoassay (ECLIA) using linear correlation analysis.Results The measurement ranges of AFP were 0.07-1 000.00 kU/L with the intra-and inter-assay CV of 5.93％ and 11.07％,and those of CEA were 0.12-500.O0 μg/L with the intra-and inter-assay CV of 7.53％ and 12.13％ respectively.The average recovery rate of AFP and CEA was 92.77％ and 94.73％,respectively.Measurements obtained by TRFMIA had strong correlation coefficients ranging from 0.93 to 0.97 when compared with those obtained by TRFIA and ECLIA.Conclusion TRFMIA,which can simultaneously detect AFP and CEA,has been successfully established.

Objective To establish a fast and quantitative light initiated chemiluminescent assay (LICA) method for high mobility group box1 (HMGB1) determination.Methods Two strains of paired HMGB 1 monoclonal antibodies were used.One was used to coat receptor microspheres.The other was labeled with biotin first and then composed with chain mildew element of affinity donor microsphere to form LICA method for HMGB1.After optimizing the reaction system,the technical specifications of the method was evaluated.Serum HMGB1 levels of common pneumonia patients (CPP) and severe pneumonia patients (SPP) were measured and compared with that of health controls.Two-sample t test was used.Results The sensitivity of LICA was 0.1 μg/L,with linear measurement ranging from 0.1 to 1 000 μg/L.The precisions of intra-and inter-analysis were 1.74％-2.92％ and 1.93％-3.73％ respectively,both were lower than 5％.The recovery rate was 99.74％ (range:94.53％-106.37％).The correlation coefficient of LICA and enzyme-linked immunosorbent assay (ELISA) was 0.888 2.The LICA method had good specificity and no obvious cross reaction with HMGB2 and HMGB3.The serum HMGB1 level in CPP (n=35) and SPP (n=25) was significantly higher than that in health controls (n=35):(6.76±3.13),(19.69±+9.04) vs (1.49±+0.74) μg/L;t values:-5.447 and-5.186,both P＜0.01.The HMGB1 levels between CPP and SPP were also significantly different (t=-3.500,P＜0.01).Conclusions The established LICA method of HMGB1 has high sensitivity and specificity with reliable results.This method is also homogeneous,fast and cleaning-free,thus has a good prospect in clinical application.

Objective To investigate the clinical procedural performance of CT-guided needle biopsy for peritoneal lesions.Methods CT-guided needle biopsy was performed in 84 consecutive patients (M : F=26 : 58) with peritoneal lesions.Results Among 84 cases,60 lesions were malignant (55 metastatic tumor,4 mesothelioma,1 lymphoma) and 24 were benign (11 tuberculosis, 13 inflammation).3 cases failed to get clear pathologic diagnosis because of lost data.Diagnostic accuracy was 91.7% (77/84).The major complications were noted in 3 patients(1 with bleeding,2 ascites exosmosis).Conclusion CT-guided needle biopsy for retroperitoneal lesions is highly practical and useful,should be considered complementary in the investigation of abdominal lesions.