Biomechanical Evaluation of 2 Endoscopic Spine Surgery Methods for Treating Lumbar Disc Herniation: A Finite Element Study.

OBJECTIVE: This study aimed to evaluate the effects of 2 endoscopic spine surgeries on the biomechanical properties of normal and osteoporotic spines. METHODS: Based on computed tomography images of a healthy adult volunteer, 6 finite element models were created. After validating the normal intact model, a concentrated force of 400 N and a moment of 7.5 Nm were exerted on the upper surface of L3 to simulate 6 physiological activities of the spine. Five types of indices were used to assess the biomechanical properties of the 6 models, range of motion (ROM), maximum displacement value, intervertebral disc stress, maximum stress value, and articular protrusion stress, and by combining them with finite element stress cloud. RESULTS: In normal and osteoporotic spines, there was no meaningful change in ROM or disc stress in the 2 surgical models for the 6 motion states. Model N1 (osteoporotic percutaneous transforaminal endoscopic discectomy model) showed a decrease in maximum displacement value of 20.28% in right lateral bending. Model M2 (unilateral biportal endoscopic model) increased maximum displacement values of 16.88% and 17.82% during left and right lateral bending, respectively. The maximum stress value of L4-5 increased by 11.72% for model M2 during left rotation. In addition, using the same surgical approach, ROM, maximum displacement values, disc stress, and maximum stress values were more significant in the osteoporotic model than in the normal model. CONCLUSION: In both normal and osteoporotic spines, both surgical approaches were less disruptive to the physiologic structure of the spine. Furthermore, using the same endoscopic spine surgery, normal spine biomechanical properties are superior to osteoporotic spines.

Kinetin inhibits hepatic stellate cell activation and induces apoptosis via interactions with the TGF-ß1/Smad signaling pathway.

Hepatic fibrosis is the pathological repair response of the liver to chronic injury; hepatic stellate cell (HSC) activation is the central link in the pathogenesis of hepatic fibrosis. Previously, we showed that kinetin, a plant cytokinin hormone, has a protective effect on CCl4-induced liver injury in mice. However, the role of kinetin in liver fibrosis remains unclear. We aimed to study these protective effects and to determine the mechanisms by which kinetin mediates HSC activation and apoptosis. For this purpose, the human HSC line LX-2 was treated with 10 ng/ml transforming growth factor-ß1 (TGF-ß1) for 24 h to stimulate activation. We found that treatment with kinetin at the sub-cytotoxic dose of 40 µg/ml for 48 h reduced the expression of the HSC activation marker α-SMA and inhibited the secretion of extracellular matrix proteins. In addition, kinetin was found to inhibit the proliferation and migration of LX-2 cells. We found that kinetin induced apoptosis in LX-2 cells by increasing the level of cleaved-caspase 3 and the Bax-to-Bcl-2 ratio. Interestingly, these effect were not observed in quiescent HSCs, suggesting that they are activation-dependent. Further study showed that kinetin attenuates activation and promotes apoptosis of LX-2 cells in vitro in part by suppressing the TGF-ß1/Smad signaling pathway.

Intraflagellar transport 20 cilia-dependent and cilia-independent signaling pathways in cell development and tissue homeostasis.

Intraflagellar transport (IFT) is an essential condition for ciliogenesis. The primary cilia protrude like antennae and act as chemical or mechanical sensory organelles that coordinate specific receptor localization and signal transduction. IFT20 is the smallest molecule in IFT complex B, which is located in both the cilia and the Golgi complex. Recent studies have shown that IFT20 is a key molecule in multiple signaling pathways. Importantly, in the function of IFT20, signal transduction is not restricted to cilia, but is also involved in non-ciliary functions. Here we summarize current knowledge regarding IFT20-mediated signaling pathways and their relationship with cell development and tissue homeostasis, and analyse the cilia-dependent and cilia-independent mechanisms of IFT20 coordinated signaling pathways and potential crosstalk between the mechanisms. This review provides a comprehensive perspective on IFT20 coordinates signaling mechanisms in cell development and tissue homeostasis.

[Predictive Value of Newly Diagnosed IgG Level in Patients with IgG-type Multiple Myeloma after Initial Treatment].

OBJECTIVE: To explore the predictive value of newly diagnosed IgG levels in the recurrence of IgG-type multiple myeloma (MM) patients after initial treatment. METHODS: The clinical and pathological data of 91 patients newly diagnosed IgG-type MM who were hospitalized in the Department of Hematology of the Second People's Hospital of Yichang and Department of Oncology of The Affiliated Hospital of Jianghan University from April 2010 to March 2019 were collected. According to the median IgG level at the time of initial diagnosis, patients were divided into high IgG group and low IgG group. The recurrence time after initial treatment was followed up, and the correlation between newly diagnosed IgG level and recurrence was analyzed by univariate and multivariate analysis, as well as the influencing factors of IgG levels in order to predict furtherly the potential mechanism of recurrence. RESULTS: Univariate survival analysis showed that high revised international staging system (R-ISS) staging, high level of bone marrow plasma cell (BMPC), lactate dehydrogenase (LDH), creatinine, ß2-microglobulin, and IgG, low level of hemoglobin and serum albumin, high-risk genetic risk, autologous hematopoietic stem cell transplantation (ASCT) were closely related to shortened recurrence time after initial treatment (all P<0.05). COX multivariate survival analysis showed that high R-ISS staging, high level of BMPC, ß2-microglobulin, LDH, and IgG, low level of serum albumin, high-risk genetic risk, ASCT were independently associated with shorter recurrence time after initial treatment (all P<0.05). The median recurrence time of IgG MM patients with high and low IgG level was 30 (7-53) months and 42 (5-65) months, respectively. The cumulative recurrence rate of MM patients with high IgG level was significantly higher than that of patients with low level (χ2=7.982, P=0.005). Univariate analysis of the difference in IgG levels showed that high level of BMPC, urea nitrogen, blood creatinine, and low level of hemoglobin and serum albumin were closely related to high IgG level of IgG-type MM patients in initial diagnosis (all P<0.05). The logistic regression analysis of the differences in IgG levels showed that low level of serum albumin were independently correlated with high IgG levels in IgG-type MM patients in initial diagnosis (P<0.05). CONCLUSION: The higher the serum IgG concentration of IgG-type MM patients at first diagnosis, the earlier the recurrence, which is related to the low level of serum albumin, and can be used as a potential recurrence predictor after complete remission of IgG-type MM patients.

Construction of ecological security pattern based on habitat quality in Tang County, Hebei, China.

As the key and hot topic in landscape ecology, ecological security pattern plays an important role in maintaining regional ecological security and achieving regional sustainable development. Based on land use data of 2016, we used the InVEST model to evaluate the habitat quality of Tang County to determine the ecological source. The resistance surface was constructed by selecting the resistance factors such as land use type, habitat quality index, vegetation coverage, distance to water, distance to settlements, distance to roads, with the resistance threshold being used to partition the ecological security pattern. Finally, the ecological security pattern of Tang County was constructed by determining the ecological corridor with the MCR model. The results showed that the ecological source of Tang County accounted for 3.3% of the total area, mainly distributed in forest land and waters with large plaque area, and the Western Ocean Reservoir (one of the four major reservoirs in Hebei Province). According to the cost resistance mutation point, the research region could be divided into prohibited development zone, restricted development zone, optimized development zone, and key development zone. The percentage of each zone was 18.9%, 43.6%, 27.6% and 9.9%, respectively. The total length of the potential ecological corridors in Tang County was 333.52 km, and was 263.91 km after optimization, which was helpful for various ecological exchanges. Our results had important guiding significance for the rational and sustainable use of land resources in Tang County, and could provide theoretical and technical supports for the decision-making of land planning and layout in Tang County.

Over-expression of Sox4 and ß-catenin is associated with a less favorable prognosis of osteosarcoma.

The purpose of this study was to examine the association of the expression of Sox4 and ß-catenin with the prognosis of osteosarcoma. A total of 108 cases of conventional osteosarcoma were involved in this study and 28 cases of osteochondroma served as controls. The expression of Sox4 and ß-catenin was detected by using immunohistochemical staining and Western blotting. The results showed that Sox4 and ß-catenin were over-expressed in 67 (62.03%) and 62 (57.41%) of 108 osteosarcoma cases, while in only 3 (10.71%) and 5 (17.86%) of 28 controls, respectively (P<0.05 for all). The expression of Sox4 and ß-catenin was associated with the distant metastasis, pathological grade and Enneking stage of patients with osteosarcoma (P<0.05 for all). The mean overall survival time and the 5-year-survival rate in osteosarcoma patients with Sox4 and ß-catenin over-expressed were significantly reduced as compared with those in Sox4 and ß-catenin low-expression group (P<0.05 for all). Cox multifactor regression analysis revealed that the distant metastasis, Enneking stage, and the expression of Sox4 and ß-catenin were independent risk factors of patients with osteosarcoma (P<0.05 for all). The findings indicated that overexpression of Sox4 and ß-catenin is associated with a poor prognosis of osteosarcoma.

Clinical Analysis of Internal Fixation Treatment of Intra-articular Calcaneal Fractures with Titanium Plate.

To explore the clinical effect of internal fixation treatment of intra-articular calcaneal fractures with titanium plate, we used open reduction and internal fixation with titanium plate to 48 treated feet from 42 patients with intra-articular calcaneal fractures. The efficacy of surgical treatment was evaluated based on assessment of pain, function, and line of force aspects according to the American Orthopedic Foot and Ankle Society scoring system. Our data show that internal fixation with titanium plate is an effective treatment for calcaneal fractures. It provides satisfactory reduction, reliable fixation, and early rehabilitation.

Effects of adenoviral vector expressing hIGF-1 on apoptosis in nucleus pulposus cells in vitro.

The excessive apoptosis of cells of the nucleus pulposus may plays an important role in intervertebral disc (IVD) degeneration. It has been shown that the pro-inflammatory cytokine tumour necrosis factor (TNF)-α can induce disc cell apoptosis. Insulin-like growth factor (IGF)-1 can promote nucleus pulposus cell proliferation; however, whether or not IGF-1 inhibits TNF-α-induced apoptosis in the nucleus pulposus has not yet been elucidated. In this study, our objective was to create a potentially therapeutic viral vector, which could be used to achieve the enforced expression of IGF-1 in rabbit nucleus pulposus cells. Furthermore, we investigated the ability of IGF-1 to reverse TNF-α-induced apoptosis in cells of the nucleus pulposus. Isolated nucleus pulposus cells were cultured to a confluent monolayer, digested with collagenase Ⅱ and purified using trypsin and differential adhesion methods. Nucleus pulposus cells were positively identified using type Ⅱ collagen immunohistochemistry. Following transfection with adenoviral vectors engineered to overexpress recombinant human IGF-1 (Ad-hIGF-1) or TNF-α, the cells were observed under a light microscope. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling (TUNEL) and flow cytometry (FCM) were used to assess the rate of apoptosis. The Ad-hIGF-1 viral vector was effectively transduced into the nucleus pulposus cells and increased IGF-1 expression as confirmed by RT-PCR and western blot analysis. In the TNF-α-treated group, a large number of apoptotic cells was observed that exhibited morphological changes associated with this form of cell death. Minimal apoptosis was observed in the Ad-hIGF-1-treated group and the control group showed no obvious signs of apoptosis. TUNEL assay revealed that the rate of apoptosis in the Ad-hIGF-1 group was significantly reduced compared with the TNF-α-treated group (P<0.01). This result was confirmed using FCM. The rate of apoptosis was also significantly increased in the TNF-α-exposed cells compared with the control group (P<0.01). Our findings strongly suggest that the adenoviral vector expressing hIGF-1 can successfully infect nucleus pulposus cells in vitro and effectively enhance the expression of IGF-1. In addition, IGF-1 reversed the TNF-α -induced apoptosis of nucleus pulposus cells. Thus, Ad-hIGF-1 may be useful in the development of clinical interventions for disc degeneration.

Effects of IGF-1 on IL-1ß-induced apoptosis in rabbit nucleus pulposus cells in vitro.

Excessive apoptosis in intervertebral disc (IVD) cells is important in IVD degeneration. Interleukin (IL)-1ß has been shown to induce apoptosis in these cells. However, whether insulin-like growth factor-1 (IGF-1) inhibits IL-1ß-induced apoptosis in the nucleus pulposus remains unclear. The purpose of this study was to investigate the effects of IGF-1 on IL-1ß-induced apoptosis in the nucleus pulposus. Cells isolated from the nucleus pulposus were grown in culture to a monolayer. These cells were identified using immuno-histochemistry for type II collagen and toluidine blue staining for glycosaminoglycans. Following exposure to IGF-1 or IL-1ß, the cells were observed using light microscopy. Giemsa staining, TdT-mediated dUTP-biotin nick end-labeling (TUNEL) and flow cytometry (FCM) were used to detect the rate of early cell death, which served as an indicator of apoptosis. In the IL-1ß group, a large number of these cells underwent apoptosis and demonstrated morphological changes associated with apoptosis. A small proportion of cells exposed to IGF-1 alone underwent apoptosis. No obvious signs of apoptosis were observed in the control group. TUNEL results revealed that the rate of apoptosis in the IGF-1 group was significantly reduced compared with that in the IL-1ß group (P<0.01), confirmed using FCM. Compared with the control group, the apoptotic rate was also significantly increased in IL-1ß-exposed cells (P<0.01). These findings strongly suggested that IGF-1 inhibits IL-1ß-induced apoptosis in the nucleus pulposus.

[Ultrastructure of anterior cruciate ligament after transplantation].

OBJECTIVE: To study the characteristics of, morphology histology and ultrastructure of anterior cruciate ligament(ACL) autograft and two-step cryopreserved ACL allograft after transplantation. METHODS: Sixty New Zealand rabbits and sixty Japanese rabbits were randomly divided into two groups: ACL autograft group and two-step cryopreserved ACL allograft group. Immunosuppressant were not used after transplantation. The histology and ultrastructure of the ACL of transplantation and normal knee were observed after 4 weeks and 12 weeks, respectively. RESULTS: The rate of remodeling process was faster in ACL autograft than in two-step cryopreserved ACL allograft, but there was similar remodeling process between two groups 12 weeks after transplantation. The proportions of large-diameter fibers(> or = 80 nm) of ACL autograft and cryopreserved ACL allograft were 6% and 24% in the 4th week, and were 0 and 2% in the 12th week, respectively. The proportions of small-diameter of fibers(< 80 nm) of ACL autogrft and cryopreserved ACL allograft were 94% and 76% in the 4th week, and 100% and 98% in the 12th week, respectively. Histologic incorporation in ACL autograft was similar to that in cryopreserved ACL allograft. CONCLUSION: Two-step cryopreserved bone-ACL-bone allograft were similar to bone-ACL-bone autograft cryopreserved in remodeling process and histology. The rate of remodeling process was faster in ACL autograft than in cryopreserved ACL allograft.