Evaluating thermosensitive chitosan/ ß-glycerophosphate sodium and fibroblast embolization for the treatment of cerebral arteriovenous malformation in a porcine model.

OBJECTIVE: To evaluate the feasibility of non-sticky thermosensitive liquid embolic material chitosan/ß-glycerophosphate sodium (C/GP) and fibroblast embolization in rete mirabile (REM) for preparing the model of cerebral arteriovenous malformation (cAVM); to study the method of microcatheter injection of C/GP-gel system; and to observe the embolization effect and histological changes of REM. METHODS: A total of 26 domestic pigs were grouped and prepared designed models, followed by different treatment methods using C/GP. C/GP embolization of the REM were performed. The brain samples were obtained after week 6's angiography and finally, subjected to H&E staining for histological examination. RESULTS: In 26 pig models, 25 pigs were successfully modeled, and 1 pig had convulsions and died during the modeling process. After embolization, angiography showed that the embolized REM was no longer developed while there was no adhesion between the tip of the microcatheter and the embolization agent. No recanalization was found in week 2 and week 6's angiography. Histological examination: the hydrogel was uniformly dispersed in REM, and REM was completely embolized. The texture was hard. REM was filled by gel and fibroblasts, the intima of the wall was clearly visible, and the smooth muscle layer was intact. No exfoliation and necrosis of the vessel wall were observed, and no inflammatory reaction was observed around the blood vessel. CONCLUSIONS: Our study provided sufficient evidence to suggest that C/GP may be a novel liquid embolic material for the endovascular treatment of cAVM. C/GP and fibroblasts can be used in the embolization of cAVM and may have broad application as an ideal embolization material for the treatment of cAVM.

Detecting the normal-direction in automated aircraft manufacturing based on adaptive alignment.

In aircraft manufacturing, the vertical accuracy of connection holes is important indicator of the quality of holes making. Aircraft products have high requirements for the vertical accuracy of holes positions. When drilling and riveting are performed by an automatic robotic system, assembly errors, bumps, offsets and other adverse conditions, can affects the accuracy of manufacturing and detection, and in turn the fatigue performance of the entire structure. To solve this problem, we proposed a technology for detecting the normal-direction based on the adaptive alignment method, built a mathematical model for posture alignment, and studied the calibration method and mechanism of the detection device. Additionally, we investigated techniques for error compensation using an electronic theodolite and other devices when the adaptive method is used for detection. In verification experiments of the method, multiple sets of results demonstrated that the key technical indicators are as follows: normal accuracy <0.5°, average deviation after correction =0.0667°. This method can effectively compensate the errors affecting hole making work in automated manufacturing, and further improve the positioning accuracy and normal-direction detection accuracy of the robot.

Surgical treatment for acute ischial tuberosity avulsion fracture: A case report.

RATIONALE: Ischial tuberosity avulsion fracture (ITAF) is a very rare sports injury, and there is currently no consensus on its diagnosis and treatment. Although conservative treatment is adequate for most patients, those with large displacement of the fracture need surgical management. PATIENT CONCERNS: A 13-year-old male athlete experienced tearing pain in the right hip during a sprint. Radiographic examination showed an avulsion fracture of the right ischial tuberosity. DIAGNOSIS: Right ITAF. INTERVENTIONS: On the 3rd day of injury, the patient was treated with open reduction and internal fixation of ITAF under general anesthesia. OUTCOMES: The patient received a systematic postoperative exercise in 2 weeks, and the fracture healed 4 weeks later. After 8 months, the patient returned to the field to participate in the competition. LESSONS: Early surgical treatment can bring about good results in the treatment of ITAF with large displacement. The longitudinal incision and subgluteal approach is an ideal choice for the operative procedure.

Avulsion Fractures of the Ischial Tuberosity: Progress of Injury, Mechanism, Clinical Manifestations, Imaging Examination, Diagnosis and Differential Diagnosis and Treatment.

Avulsion fracture of the ischial tuberosity (AFIT) is a rare adolescent sports injury. At present, there is no consensus on its therapeutic paradigm, but conservative treatment appears to be the predominate choice. Furthermore, the degree of fracture displacement (DFD) remains as an important factor in determining whether AFIT needs internal fixation. The aim of the present study was to review and update the injury mechanism, clinical manifestations, imaging examination, diagnosis and differential diagnosis, and treatment of AFIT. A literature search was performed on a variety of databases using text words, and the results were limited to the English language. This review provides an important reference for the diagnosis and treatment of AFIT. AFIT can be easily misdiagnosed. Therefore, a detailed medical history and imaging examination are crucial for a correct diagnosis and differential diagnosis. For the choice of treatment of AFIT, it is necessary to consider not only the size of the fracture and DFD, but also the long-term functional needs of the patient.

Modified insulin-like growth factor 1 containing collagen-binding domain for nerve regeneration.

Insulin-like growth factor 1 (IGF-1) is a potential nutrient for nerve repair. However, it is impractical as a therapy because of its limited half-life, rapid clearance, and limited target specificity. To achieve targeted and long-lasting treatment, we investigated the addition of a binding structure by fusing a collagen-binding domain to IGF-1. After confirming its affinity for collagen, the biological activity of this construct was examined by measuring cell proliferation after transfection into PC12 and Schwann cells using a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. Immunofluorescence staining was conducted to detect neurofilament and microtubule-associated protein 2 expression, while real time-polymerase chain reaction was utilized to determine IGF-1 receptor and nerve growth factor mRNA expression. Our results demonstrate a significant increase in collagen-binding activity of the recombinant protein compared with IGF-1. Moreover, the recombinant protein promoted proliferation of PC12 and Schwann cells, and increased the expression of neurofilament and microtubule-associated protein 2. Importantly, the recombinant protein also stimulated sustained expression of IGF-1 receptor and nerve growth factor mRNA for days. These results show that the recombinant protein achieved the goal of targeting and long-lasting treatment, and thus could become a clinically used factor for promoting nerve regeneration with a prolonged therapeutic effect.

Knockdown MiR-302b Alleviates LPS-Induced Injury by Targeting Smad3 in C28/I2 Chondrocytic Cells.

BACKGROUND/AIMS: Osteoarthritis (OA) is one of the most common chronic degenerative diseases. Many studies have demonstrated the role of microRNAs (miRNAs) in OA; however, the role of miR-302b in OA remains elusive. The aim of this study was to identify the role of miR-302b in LPS-induced injury in chondrocytes. METHODS: Human OA chondrocytes (C28/12 cell line) were transfected with miR-302b inhibitor and miR-302b mimic to investigate the effects of miR-302b expression on chondrocyte apoptosis and inflammation, and to identify the miR-302b target proteins. RESULTS: LPS treatment of chondrocytes significantly reduced cell viability and increased apoptotic rate. LPS treatment also increased the expression of inflammatory cytokines compared to control. miR-302b was up-regulated in LPS-induced chondrocytes. miR-302b was either suppressed or overexpressed in LPS-induced chondrocytes by transient transfection. miR-302b mimic transfection accelerated the effects of LPS on cell viability, apoptosis and inflammation. Of contrast, miR-302b inhibition represented a reverse effect. Dual luciferase activity demonstrated that Smad3 is a direct target for miR-302b and its expression was negatively regulated by miR-302b. In addition, miR-302b inhibition suppressed inflammation in LPS treated chondrocytes by up-regulating Smad3 expression. Moreover, LPS induced down-regulation of Notch and mTOR signaling pathway-related protein expressions, and miR-302b inhibition increased the expressions of Notch and mTOR signaling pathway-related proteins. We further found that miR-302b negatively regulated Notch2 levels through direct targeting its 3'UTR. CONCLUSIONS: These results suggest that miR-302b suppression may function as a protector in suppressing the inflammation during the development and progression of OA by up-regulating the target Smad3 expression.

Knockdown of microRNA-203 alleviates LPS-induced injury by targeting MCL-1 in C28/I2 chondrocytes.

Several microRNAs (miRs) are associated with osteoarthritis (OA) and are also functionally implicated in the pathogenesis of the disease. This study was aimed to investigate the potential roles of miR-203 in the development and progression of OA, as well as to illustrate the possible molecular mechanism. OA was simulated in human cartilage C28/I2 cells with treatments of lipopolysaccharide (LPS). LPS-induced cell injury was evaluated according to cell viability, apoptosis and release of pro-inflammatory cytokines. Expression of miR-203 after LPS treatment was assessed. Then, miR-203 was aberrantly expressed, followed by evaluation of LPS-induced cell injury. The target gene of miR-203 was virtually screened by bioinformatics method and verified by luciferase assay. Moreover, the potential associated signaling pathways were also investigated. Results showed that LPS induced decrease of cell viability and increases of cell apoptosis, release of inflammatory cytokines and expression of miR-203. LPS-induced alterations were aggravated by miR-203 overexpression but were alleviated by miR-203 inhibition. Myeloid cell leukemia-1 (MCL-1) was hypothesized and subsequently verified to be a target of miR-203, and miR-203 inhibition affected C28/I2 cells through up-regulating MCL-1. In addition, LPS-induced down-regulations of key kinases as well as phosphorylated kinases were further down-regulated by miR-203 overexpression but were abrogated by miR-203 inhibition. In conclusion, this study suggests that miR-203 suppression may inhibit the progression of OA by targeting MCL-1 and activating the Wnt/ß-Catenin and JAK/STAT signal pathways.

Transcription factor Oct4 promotes osteosarcoma by regulating lncRNA AK055347.

Osteosarcoma is the most common primary bone tumor in children and adolescents, typically presenting with a poor prognosis. Octamer-binding transcription factor 4 (Oct4) protein, encoded by the POU class 5 homeobox 1 gene, is important in maintaining self-renewal of pluripotent stem cells, and is closely associated with cancer. However, its role in osteosarcoma remains to be elucidated. The present study observed Oct4 was markedly increased in osteosarcoma cell lines and in human osteosarcoma tissue samples. Following Oct4 downregulation by small interfering RNA (siRNA) in osteosarcoma F5M2 cells, the cells exhibited significant decreases in proliferation and invasion ability, and an increase in cell apoptosis. Notably, downregulation of Oct4 decreased the expression of AK055347, a newly identified long noncoding RNA (lncRNA) in human tissues. The downregulation of AK055347 by siRNA resulted in a significant suppressive effect on proliferative and invasive ability, and promotion of cell apoptosis in osteosarcoma cells. Thus, the current study suggests Oct4 exerts a promoting effect in osteosarcoma, and identifies a novel lncRNA in osteosarcoma progression.

Intracranial Demyelinating Pseudotumor: A Case Report and Review of the Literature.

Demyelinating pseudotumor is a rare inflammatory demyelinating disease of the central nervous system (CNS) that has a similar clinical presentation and computed tomography (CT) and magnetic resonance imaging (MRI) imaging findings as brain tumors or abscesses. Unlike brain tumors, demyelinating pseudotumors respond well to steroid hormones. There are only a few reported cases of intracranial demyelinating pseudotumors in the literature. In this case report, we present the diagnosis and treatment of demyelinating pseudotumor in a patient whose condition was initially misdiagnosed as an astrocytoma. Based on the literature and our case, we formulated an outline for the differential diagnosis of demyelinating pseudotumor and astrocytoma. A timely and correct diagnosis of demyelinating pseudotumor would avoid blind surgery, radiotherapy and chemotherapy, which are used to treat brain tumors.

Interleukin 1ß and tumor necrosis factor α promote hFOB1.19 cell viability via activating AP1.

Bone trauma healing is a complex physiological process, which may involve the function of various inflammatory cytokines. Our study aimed to explore the roles of inflammatory cytokines in bone trauma healing and reveal the potential mechanism. Concentrations of interleukin (IL)-6, IL-1ß and tumor necrosis factor alpha (TNF-α) in peripheral blood serum of bone trauma patients after surgery were determined by ELISA. The human osteoblast hFOB1.19 cell line was cultured to determine the effect of these cytokines in cell viability using MTT assay. In addition, luciferase reporter assay was performed to investigate the activator protein 1 (AP1) transcriptional activity, and small interfering RNA was transfected to inhibit FOS, a component of AP1 molecule. IL-6, IL-1ß and TNF-α exhibited higher level in patients with more severe bone traumas after surgery. IL-1ß and TNF-α, but not IL-6, induced a significant increase of hFOB1.19 viability after three days of treatment (P < 0.05). IL-1ß and TNF-α could activate AP1 transcriptional activity in hFOB1.19 cells (P < 0.001), but the activation was inhibited when cells were pretreated with inhibitor of JNKs, SP600125 (P < 0.001). Besides, the effect of IL-1ß and TNF-α on promoting viability was significantly inhibited after knockdown of FOS. These findings indicated that IL-1ß and TNF-α played an important role in promoting osteoblast viability via the activation of AP1 transcriptional activity, which was likely to involve the JNK/MAPK signaling pathway. Modulating inflammatory cytokines is a potential strategy for improving the outcome of bone trauma healing.

Hypoxia promotes drug resistance in osteosarcoma cells via activating AMP-activated protein kinase (AMPK) signaling.

PURPOSE: Drug resistance has been recognized to be a major obstacle to the chemotherapy for osteosarcoma. And the potential importance of hypoxia as a target to reverse drug resistance in osteosarcoma has been indicated, though the mechanism underlining such role is not clarified. The present study aims to investigate the role of hypoxia in the drug resistance in osteosarcoma cells via activating AMP-activated protein kinase (AMPK) signaling. EXPERIMENTAL DESIGN: We investigated the promotion of the resistance to doxorubicin of osteosarcoma MG-63 and U2-os cells in vitro, and then determined the role of hypoxia-inducible factor-1 (HIF-1)α and HIF-1ß, the activation and regulatory role of AMPK in the osteosarcoma U2-os cells which were treated with doxorubicin under hypoxia. RESULTS: It was demonstrated that hypoxia significantly reduced the sensitivity of MG-63 and U2-os cells to doxorubicin, indicating an inhibited viability reduction and a reduced apoptosis promotion. And such reduced sensitivity was not associated with HIF-1α, though it was promoted by hypoxia in U2-os cells. Interestingly, the AMPK signaling was significantly promoted by hypoxia in the doxorubicin-treated U2-os cells, with a marked upregulation of phosphorylated AMPK (Thr 172) and phosphorylated acetyl-CoA carboxylase (ACC) (Ser 79), which were sensitive to the AMPK activator, AICAR and the AMPK inhibitor, Compound C. Moreover, the promoted AMPK activity by AICAR or the downregulated AMPK activity by Compound C significantly reduced or promoted the sensitivity of U2-os cells to doxorubicin. CONCLUSION: The present study confirmed the AMPK signaling activation in the doxorubicin-treated osteosarcoma cells, in response to hypoxia, and the chemical upregulation or downregulation of AMPK signaling reduced or increased the chemo-sensitivity of osteosarcoma U2-os cells in vitro. Our study implies that AMPK inhibition might be a effective strategy to sensitize osteocarcoma cells to chemotherapy.

Experimental study of temperature-sensitive chitosan/ß-glycerophosphate embolic material in embolizing the basicranial rete mirabile in swines.

The aim of the present study was to evaluate the feasibility of the non-adhesive temperature-sensitive liquid embolic material, chitosan/ß-glycerophosphate (C/GP), in embolizing the basicranial rete mirabile (REM) in a swine model of cerebral arteriovenous malformation (cAVM). A total of 24 domestic swines were used as the experimental animals, among which 12 pigs underwent direct embolization of one side of the REM, while the other 12 pigs underwent embolization of the bilateral REM following anastomosis of the carotid artery and jugular vein. A super-selective microcatheter was introduced into the REM during the embolization procedure, and the C/GP hydrogel was injected until an image of the REM disappeared in the angiography examination. Further angiography examinations were performed after 2 and 6 weeks, and histological examination of the REM was performed after 6 weeks. Of the 24 domestic swines, 23 cases underwent successful thrombosis. Convulsions occurred in one case and that pig died during the embolization procedure. Following embolization, the angiography observations revealed that the embolized REM was no longer able to be developed, and adhesion of the microcatheter tip with the embolic agent did not occur. In addition, no apparent revascularization was observed in the angiography examinations performed at weeks 2 and 6. Therefore, the current preliminary study indicated that use of the non-adhesive temperature-sensitive embolic material was feasible for the embolization of cAVM; thus, C/GP may be used as an ideal embolic material for the treatment of cAVM.

Epilysin is overexpressed in glioblastoma and related to clinical outcome of patients.

As the newest identified member of the matrix metalloproteinase (MMP) family, the expression pattern and function of epilysin (MMP-28) are still not well understood. Although epilysin was found to play an evolutionarily conserved role in neural development, the expression and function of epilysin in malignant glioma are unknown. Therefore, the aim of the present study was to quantitatively evaluate the expression level of epilysin in glioblastoma (GBM) and its association with clinical outcome of patients. For this purpose, a total of 216 GBM specimens and 31 normal brain specimens were collected in the present study. Expression level of epilysin was determined by immunohistochemistry assay and immunoreactivity score system. MGMT promoter methylation and IDH1/2 mutation status in GBM were also evaluated. Results showed that the positive rate of epilysin staining in GBM was significantly elevated compared with that in normal brain. Positive epilysin staining was associated with low KPS score, unmethylated MGMT promoter and wild-type IDH. Kaplan-Meier analysis showed that patients with GBM of positive epilysin staining were more likely to have unfavorable overall survival. Multivariate analysis revealed that epilysin was an independent and significant prognostic marker of GBM. These results proved for the first time that epilysin expression was significantly elevated in GBM and can be potentially used to predict prognosis in patients with GBM.

Inhibitory effects of a polysaccharide extract from the Chaga medicinal mushroom, Inonotus obliquus (higher Basidiomycetes), on the proliferation of human neurogliocytoma cells.

This study aimed to investigate the inhibitory roles of a polysaccharide extract from Inonotus obliquus on U251 human neurogliocytoma cells cultured in vitro. After administering the polysaccharide extract from I. obliquus to U251 cells cultivated in vitro, methyl thiazolyl tetrazoliym assay was performed to measure the inhibitory effects of the extract on tumor cell proliferation. The expression of the apoptosis-related proteins Bcl-2 and caspase-3 were determined by Western blotting. Different concentrations of I. obliquus extract (25, 50, 100, 200, and 500 µg/mL) were added to U251 cells at 24, 48, and 72 hours. Methyl thiazolyl tetrazoliym assay showed that the inhibition ratio increased with increased extract concentration and prolonged treatment duration. The I. obliquus extract sharply decreased the expression of Bcl-2 but dramatically increased the expression of caspase-3. This function was gradually enhanced with increased drug concentration and prolonged treatment duration. The I. obliquus extract can inhibit the proliferation of tumor cells. This inhibition function is closely related to the downregulation of Bcl-2 and the upregulation of caspase-3.

Poly(lactic-co-glycolic acid) conduit for repair of injured sciatic nerve: A mechanical analysis.

Tensile stress and tensile strain directly affect the quality of nerve regeneration after bridging nerve defects by poly(lactic-co-glycolic acid) conduit transplantation and autogenous nerve grafting for sciatic nerve injury. This study collected the sciatic nerve from the gluteus maximus muscle from fresh human cadaver, and established 10-mm-long sciatic nerve injury models by removing the ischium, following which poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts were transplanted. Scanning electron microscopy revealed that the axon and myelin sheath were torn, and the vessels of basilar membrane were obstructed in the poly(lactic-co-glycolic acid) conduit-repaired sciatic nerve following tensile testing. There were no significant differences in tensile tests with autogenous nerve graft-repaired sciatic nerve. Following poly(lactic-co-glycolic acid) conduit transplantation for sciatic nerve repair, tensile test results suggest that maximum tensile load, maximum stress, elastic limit load and elastic limit stress increased compared with autogenous nerve grafts, but elastic limit strain and maximum strain decreased. Moreover, the tendencies of stress-strain curves of sciatic nerves were similar after transplantation of poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts. Results showed that after transplantation in vitro for sciatic nerve injury, poly(lactic-co-glycolic acid) conduits exhibited good intensity, elasticity and plasticity, indicating that poly(lactic-co-glycolic acid) conduits are suitable for sciatic nerve injury repair.

[Prediction of femoral remodeling after implantation of artifical femoral head].

By integrating bone-remodeling theory with finite element (FEM) models, the behavior of femoral remodeling after implantation of artificial femoral head was simulated and the stress shield effect of artificial femoral head on the femur was analyzed quantitatively. Bone was calculated with finite element code of the FEM model. The normal loading condition of femur was used as Model One, and the stress condition that bone was fixed by the bone-cement of the artificial head with collar was used as Model Two. It has been shown that bone was stress-shielded by the artificial femoral head and femur resorbed. Bone resorption near the proximal artificial stem was very severe. Its cross-section resorbed the greatest. The ratio of cross-sectional resorption was psi = 31.3% and the ratio of loss of the anti-bend cross-sectional modulus was zeta = 54.58%.