LCN2 Promotes Proliferation and Glycolysis by Activating the JAK2/STAT3 Signaling Pathway in Hepatocellular Carcinoma.

This study aimed to explore the molecular mechanism of LCN2 regulating aerobic glycolysis on abnormal proliferation of HCC cells. Based on the prediction of GEPIA database, the expression levels of LCN2 in hepatocellular carcinoma tissues were detected by RT-qPCR analysis, western blot, and immunohistochemical staining, respectively. In addition, CCK-8 kit, clone formation, and EdU staining were used to analyze the effect of LCN2 on the proliferation of hepatocellular carcinoma cells. Glucose uptake and lactate production were detected using kits. In addition, western blot was used to detect the expressions of aerobic glycolysis-related proteins. Finally, western blot was used to detect the expressions of phosphorylation of JAK2 and STAT3. We found LCN2 was upregualted in hepatocellular carcinoma tissues. CCK-8 kit, clone formation, and EdU staining results showed that LCN2 could promote the proliferation in hepatocellular carcinoma cells (Huh7 and HCCLM3 cells). Western blot results and kits confirmed that LCN2 significantly promotes aerobic glycolysis in hepatocellular carcinoma cells. Western blot results showed that LCN2 could significantly upregulate the phosphorylation of JAK2 and STAT3. Our results indicated that LCN2 activated the JAK2/STAT3 signaling pathway, promoted aerobic glycolysis, and accelerated malignant proliferation of hepatocellular carcinoma cells.

Enhancement of dielectric constant of polyimide by doping with modified silicon dioxide@titanium carbide nanoparticles.

Electrode materials used in supercapacitors must have a high dielectric constant and a low dielectric loss along with good mechanical properties. In this study, the dielectric constant of polyimide (PI) was improved by preparing a PI/SiO2@TiC composite. A homogeneous dispersion of SiO2@TiC nanoparticles was obtained by the hydrolyzation of tetraethyl orthosilicate, which resulted in the formation of a thin layer of SiO2 on TiC particles. Polyamic acid was doped with the modified SiO2@TiC nanoparticles by mechanical blending to synthesize the PI/SiO2@TiC composite, and its dielectric properties were investigated. Scanning electron microscopy studies confirmed that the SiO2@TiC particles were homogeneously dispersed in the PI matrix and did not exhibit agglomeration. An increase in the SiO2@TiC filler content increased the dielectric constant and the dielectric loss of the composite, but decreased its breakdown strength and deteriorated its mechanical properties. Thus, the addition of SiO2@TiC particles to PI is suitable for improving its dielectric properties while maintaining its flexibility.

Three-dimensional analysis of cervical spine segmental motion in rotation.

INTRODUCTION: The movements of the cervical spine during head rotation are too complicated to measure using conventional radiography or computed tomography (CT) techniques. In this study, we measure three-dimensional segmental motion of cervical spine rotation in vivo using a non-invasive measurement technique. MATERIAL AND METHODS: Sixteen healthy volunteers underwent three-dimensional CT of the cervical spine during head rotation. Occiput (Oc) - T1 reconstructions were created of volunteers in each of 3 positions: supine and maximum left and right rotations of the head with respect to the bosom. Segmental motions were calculated using Euler angles and volume merge methods in three major planes. RESULTS: Mean maximum axial rotation of the cervical spine to one side was 1.6° to 38.5° at each level. Coupled lateral bending opposite to lateral bending was observed in the upper cervical levels, while in the subaxial cervical levels, it was observed in the same direction as axial rotation. Coupled extension was observed in the cervical levels of C5-T1, while coupled flexion was observed in the cervical levels of Oc-C5. CONCLUSIONS: The three-dimensional cervical segmental motions in rotation were accurately measured with the non-invasive measure. These findings will be helpful as the basis for understanding cervical spine movement in rotation and abnormal conditions. The presented data also provide baseline segmental motions for the design of prostheses for the cervical spine.

Effects of glucocorticoid on BMD, micro-architecture and biomechanics of cancellous and cortical bone mass in OVX rabbits.

The incidence of osteoporosis continues to increase with progressively aging populations. The purpose of this study was to detect the effects of glucocorticoid (GC) treatment on bone mineral density (BMD), biomechanical strength and micro-architecture in cancellous and cortical bone in ovariectomized (OVX) rabbits. Twenty adult female New Zealand white rabbits were randomly divided into three groups. The OVX-GC group (n=8) received a bilateral ovariectomy first and then daily GC treatment (methylprednisolone sodium succinate, 1mg/kg/day) for 4 weeks beginning 2 weeks after ovariectomy treatment. The OVX group (n=4) received a bilateral ovariectomy without GC treatment. The sham group (n=8) only received the sham operation. BMD was determined prior to and 6 weeks after the operation in the spine. Six weeks after the operation, the animals were sacrificed, and cancellous bone specimens were harvested from the femoral condyle and lumbar vertebrae. Cortical bone specimens were obtained from the femoral midshaft. The femoral specimens were scanned for apparent BMD. All specimens were tested mechanically and analyzed by microcompute tomography (micro-CT). In cancellous bone, GC treatment resulted in significant decreases in BMD, bone biomechanical strength and micro-architecture parameters in lumbar vertebrae. Similar trends in BMD and micro-architectural changes were also observed in the femoral condyle in the OVX-GC group compared with the sham group. However, there was no significant decline in any parameter in either lumbar vertebrae or femoral condyle in the OVX group. Similarly, no significant difference was found in any parameter in cortical bone among the three groups. Thus, the 4-week GC treatment in OVX rabbits could result in a significant bone loss in cancellous bone but not in cortical bone. This model is comparable to the osteoporosis-related changes in humans. OVX alone was not sufficient to induce osteoporosis.

Biomechanical evaluation of a novel total cervical prosthesis in a single-level cervical subtotal corpectomy model: an in vitro human cadaveric study.

BACKGROUND: Anterior cervical subtotal corpectomy and fusion provides extensive decompression in the treatment of cervical myelopathy. However, early adjacent segment degeneration may arise due to the abnormal kinematics. To the best of our knowledge, this is the first report on a newly-designed total cervical prosthesis (TCP) to preserve the normal kinematics of cervical spine. The purpose of this study was to compare the cervical range of motion (ROM) of TCP with anterior cervical plating (ACP) in a single-level cervical subtotal corpectomy model. STUDY DESIGN: An in vitro biomechanical study of a novel total cervical prosthesis (TCP) using a cadaveric model. MATERIALS AND METHODS: After evaluation of the ROM of the 14 human cadaveric cervical spines (C(2)-T(1)) (intact group), single-level subtotal corpectomy models at the C(5) levels were performed. All specimens were randomized, instrumented with ACP (n = 7) and TCP (n = 7) from C(4) to C(6). All specimens were tested for flexion/extension, lateral bending, and axial rotation loading. The ROM of implanted segments (C(4)-C(6)) and adjacent segments (C(3)/C(4) and C(6)/C(7)) were monitored, respectively. RESULTS: TCP was found to accurately recapitulate the preoperative ROM both in the adjacent segments (C(3)/C(4) and C(6)/C(7)) and the implanted segments (C(4)-C(6)). In the adjacent segments, no significant difference was found in ROM(C3/C4) between the TCP group and the intact group in flexion, extension, and lateral bending. In the implanted segments, TCP preserved well the ROM(C4-C6), with 5.29° in flexion, 12.27° in extension, 8.95° in right lateral bending, and 7.50° in left lateral bending. In contrast, the mean ROM(C4-C6) in the ACP group was lower than those in the TCP group and the intact group significantly in all directions (P < 0.05). In addition, compared with the ACP group, the mean ROM(C3-C7) in TCP group increased by 32.6% (P = 0.034) in flexion, 62.9% (P = 0.008) in extension, 24.8% (P > 0.05) in lateral bending, and 36.0% (P < 0.01) in rotation. Compared with the intact group, the TCP group showed moderate decrease in flexion and moderate increases in extension, lateral bending, and rotation. But no significant differences were detected (P > 0.05). CONCLUSIONS: Biomechanical analyses suggest that TCP preserves ROM in the implanted segments after cervical subtotal corpectomy. TCP will not induce compensatory motion in the adjacent segments, thus may possibly help prevent adjacent segment degeneration.