Clinical Efficacy of CT-Guided Continuous Catheterization Drainage for Spinal Tuberculosis with Large Abscesses.

OBJECTIVE: This study aimed to determine the efficacy of computed tomography (CT)-guided local catheterization for the treatment of spinal tuberculosis (TB) with abscess. METHODS: Clinical data from 22 cases of lumbar TB with abscess receiving treatments from July 2015 to January 2021 were analyzed. Some patients (n = 11) underwent pure surgery (control group) and the others (n = 11) received CT-guided catheterization drainage. The operation and hospitalization time, erythrocyte sedimentation rate (ESR), visual analog scale (VAS), ASIA damage grade, and C-reactive protein (CRP) levels of both groups were compared. RESULTS: The operation time, intraoperative blood loss, and hospital stay of the observation group were significantly less than those of the control group (P < 0.05). As the differences in preoperative ESR, CRP, and VAS scores between both groups did not reach significance (P > 0.05), after treatments, the observation group had a lower level of ESR and CRP (P < 0.05); the postoperative VAS scores of the two groups decreased (P > 0.05). Before treatment, the control group comprised 2 cases of ASIA grade A, 1 case of B, 6 cases of C, and 2 cases of D with 3 patients having dyskinesia. After surgery, the motor function of the patients was improved, and there were 3 cases of ASIA D and 8 cases of E. Meanwhile, the preoperative observation group consisted of 9 cases of ASIA D and 2 cases of E. Due to CT-guided catheterization, all patients achieved clinical healing (ASIA E) when the lesions were significantly alleviated, and symptoms such as low back pain and lower extremity pain disappeared. CONCLUSION: CT-guided percutaneous catheter drainage for continuous administration of drugs is effective treatment for spinal TB with abscess, when shortening the operation and hospitalization time and reducing intraoperative blood loss and erythrocyte sedimentation rate. It is worthy of popularization and application.

MicroRNA-494 represses osteosarcoma development by modulating ASK-1 related apoptosis complexes.

BACKGROUND: MicroRNA (miR)-494 had been proven to be involved in tumor pathogenesis, while studies on miR-494 and osteosarcoma (OS) are still limited. In the current study, we aimed to explore the expression pattern and the roles of miR-494 in the development of OS. METHODS: Mouse models and osteoblastic cells were used to investigate the functions of miR-494. A case-control study including 87 OS patients and 100 controls was also conducted to investigate the prognostic value of miR-494. RESULTS: Animal researches and human studies showed that miR-494 expression level in OS tissue (OST) was down-regulated compared to paracancerous tissue (PT), and had a significant positive association with its level in serum (P<0.05). Gain of miR-494 function suppressed OS tumor growth and promoted apoptosis of OS cells, while loss of miR-494 inhibited apoptosis and promoted invasion of osteoblastic cells. MiR-494 expressions in both OST and serum were correlated with the T stage, lymph node metastasis and distant metastasis of OS (P<0.05). Results of survival analysis showed that compared to patients with high miR-494 level, the overall survival rate in 24 months was significantly lower in the low miR-494 group (P<0.05). In vitro study revealed that miR-494 interacted with apoptosis signal regulating kinase 1 (ASK-1)/serine-threonine kinase receptor-associated protein (STRAP)/14-3-3 complex to promote the activation of tumor necrosis factor-α (TNF-α)/ASK-1-mediated apoptosis. CONCLUSIONS: These results revealed that miR-494 functioned as a tumor suppressor and improved the prognosis of OS via modulating apoptosis complexes.

[Effectiveness analysis of Lenke type 1 adolescent idiopathic scoliosis with different proximal fixation vertebra].

Objective: To investigate the short-term effectiveness of proximal fixation of one vertebra above to the upper end vertebra and the upper end vertebra in the treatment of Lenke type 1 adolescent idiopathic scoliosis (AIS) patients with preoperative right higher shoulder. Methods: The clinical data of 37 Lenke type 1 AIS patients treated with posterior correction between January 2010 and December 2015 were retrospectively analysed. According to proximal fixation vertebra, the patients were divided into 2 groups: group A ( n=17), proximal fixation of one vertebra above to the upper end vertebra; group B ( n=20), proximal fixation of the upper end vertebra. There was no significant difference in gender, age, Risser stage, radiographic shoulder height (RSH), flexibility of proximal thoracic curve, flexibility of main thoracic curve, flexibility of thoracolumbar/lumbar curve between 2 groups ( P>0.05). The main thoracic curve Cobb angle, proximal thoracic curve Cobb angle, thoracolumbar/lumbar curve Cobb angle, apical vertebral translation (AVT), clavicle angle (CA), RSH, coronal trunk shift, sagittal trunk shift, thoracic kyphosis (TK), and lumbar lordosis (LL) were measured by X-ray film before operation, and at 1 month, 1 year, and 2 years after operation. The correction indexes of main thoracic curve were evaluated, including the correction degree and correction rate of main thoracic curve and AVT correction at 1 month after operation, the loss degree and the loss rate of the correction of main thoracic curve at 2 years after operation. Results: The operation time and intraoperation blood loss in group A were significantly greater than those in group B ( P<0.05). All the patients were followed up, and the follow-up time was 2-4 years (mean, 2.8 years) in group A and 2-3.5 years (mean, 2.6 years) in group B. No serious complication such as nerve damage occurred during perioperative period and follow-up period. No complication such as failure of fusion, loosening and rupture of internal fixator, adjacent segment degeneration, and proximal junctional kyphosis occurred. There was no significant difference between 2 groups in the correction degree and correction rate of main thoracic curve and AVT correction at 1 month after operation, the loss degree and the loss rate of the correction of main thoracic curve at 2 years after operation ( P>0.05). Comparison within the two groups: except for LL had no significant difference between pre- and post-operation ( P>0.05), the other indicators were significantly improved after operation ( P<0.05) in the two groups. There were significant differences in RSH, CA, proximal thoracic curve Cobb angle, and thoracolumbar/lumbar curve Cobb angle at each time point after operation ( P<0.05), and there were spontaneous correction during follow-up; however, there was no significant difference in main thoracic curve Cobb angle, AVT, TK, LL, trunk shift at each time point after operation ( P>0.05), and there was no significant loss during follow-up. Comparison between the two groups: there was no significant difference in all the radiographic indexes at pre- and post-operation ( P>0.05). Conclusion: For Lenke type 1 AIS patients with preoperative right high shoulder, proximal fixation vertebra be fixed to the upper end vertebral can obtain satisfactory short-term orthopedic effectiveness and reduce blood loss and operation time.

lncRNAPVT1 targets miR-152 to enhance chemoresistance of osteosarcoma to gemcitabine through activating c-MET/PI3K/AKT pathway.

BACKGROUND: LncRNA PVT1 has been reported to be involved in a variety of biological processes, including cell proliferation, cell differentiation and cancer progression. However, the mechanism by which LncRNA PVT1 contributes to chemoresistance of osteosarcoma cell, has not been fully elucidated. METHODS: We first generatedLncRNA PVT1-overexpressed MG63 cells and LncRNA PVT1 knockdown MG63/DOX cells. Then, we examined the effect of LncRNA PVT1 on cell viability and colony formation ability by MTT assay and soft agar assay, respectively. In addition, we performed flow cytometry analysis to detect apoptosis induced by GEM. Dual luciferase reporter assay and RIP were used to confirmed the interaction between LncRNA PVT1 and miR-152. Finally, we determined protein level of c-MET, p-PI3K, and p-AKT by westernblot. RESULTS: LncRNA PVT1 overexpression promoted cell proliferation and exhibited the anti-apoptotic property in LncRNA PVT1-overexpressing MG63 cells treated with gemcitabine. While, LncRNA PVT1-depleted MG63/DOX cells treated with gemcitabine exhibited significant lower survival rate and high percentage of apoptosis. Next, we found that LncRNA PVT1 could target and downregulated the level of miR-152. Interestingly, miR-152 greatly rescued the biological outcomes of LncRNA PVT1 not only in MG63 but also in MG63/DOX cells. We observed that LncRNA PVT1 markedly induced PI3K/AKT pathway activation, which was abolished by miR-152 mimics overexpression. Finally, c-MET inhibitor was used to confirm the essential role of c-MET in LncRNA PVT1 and miR-152-regulated PI3K/AKT signaling. CONCLUSION: We showed thatlncRNA PVT1 played a contributory role in chemoresistance of osteosarcoma cells through c-MET/PI3K/AKT pathway activation, which was largely dependent on miR-152. Our findings advance our understanding of how lncRNA PVT1 promotes chemoresistance of osteosarcoma cells and facilitate development of novel strategies for treating osteosarcoma.

MiR-532 downregulation of the Wnt/ß-catenin signaling via targeting Bcl-9 and induced human intervertebral disc nucleus pulposus cells apoptosis.

OBJECTIVE: Intervertebral disc degeneration was characterized with aberrant intervertebral disc nucleus pulposus cells apoptosis. MiR-532 was reported to be up-regulated in the patients with intervertebral disc degeneration. However, the role of miR-532 in intervertebral disc degeneration remains unclear. Thus, current study aim to investigate the effects of miR-532 on human intervertebral disc nucleus pulposus cells. METHODS: Quantitative PCR was firstly used to evaluate the level of miR-532 expression in intervertebral disc nucleus pulposus cells. Then, luciferase reporter assays was used to confirm the target genes of miR-532. The effects of miR-532 on cell proliferation were assayed using EdU transfection. Next, apoptosis level was examined by flow cytometry utilizing Annexin V-FITC/PI double staining, and the protein expression in cells was detected with Western blotting. Finally, The expression of ß-catenin protein was demonstrated by fluorescence confocal microscopy and the interaction between ß-catenin and Bcl-9 was detected by co-immunoprecipitation. RESULTS: MiR-532 was significantly upregulated in patient with intervertebral disc degeneration. In addition, intervertebral disc nucleus pulposus cells apoptosis was significantly increased in miR-532 mimics treated group. Moreover, Bcl-9 was confirmed to be a direct target of miR-532 via luciferase reporter assays and western blot assays. CONCLUSION: MiR-532 downregulation of the Wnt/ß-catenin signaling via targeting Bcl-9 and induced human intervertebral disc nucleus pulposus cells apoptosis.

Delocalized Claudin-1 promotes metastasis of human osteosarcoma cells.

Tight junction proteins (TJPs) including Claudins, Occludin and tight junction associated protein Zonula occludens-1 (ZO-1), are the most apical component of junctional complex that mediates cell-cell adhesion in epithelial and endothelial cells. In human malignancies, TJPs are often deregulated and affect cellular behaviors of tumor cells. In this study, we investigated alternations of TJPs and related biological characteristics in human osteosarcoma (OS). Claudin1 was increased in the metastatic OS cells (KRIB and KHOS) compared with the normal osteoblast cells (hFOB1.19) or primary tumor cells (HOS and U2OS), whereas no significant difference was found in Occludin and ZO-1. Immunohistochemistry, immunofluorescence and Western blotting revealed that Claudin1 was initially localized at cell junctions of normal osteoblasts, but substantially delocalized to the nucleus of metastatic OS cells. Phenotypically, inhibition of the nucleus Claudin1 expression compromised the metastatic potential of KRIB and KHOS cells. Moreover, we found that protein kinase C (PKC) but not PKA phosphorylation influenced Claudin1 expression and cellular functions, as PKC inhibitor (Go 6983 and Staurosporine) or genetic silencing of PKC reduced Claudin1 expression and decreased the motility of KRIB and KHOS cells. Taken together, our study implied that delocalization of claudin-1 induced by PKC phosphorylation contributes to metastatic capacity of OS cells.

Letter regarding Li JS et al. entitled "ERCC polymorphisms and prognosis of patients with osteosarcoma".

With great interest, we read the article "ERCC polymorphisms and prognosis of patients with osteosarcoma" (by Li JS et al.), which has reached important conclusions about the relationship between ERCC polymorphisms and osteosarcoma prognosis. Through quantitative analysis, the meta-analysis showed that ERCC2 Lys751Gln (ORGG vs. AA = 0.40 (95%CI = 0.1-0.86), P heterogeneity = 0.502; I (2) = 0 %) and ERCC5 His46His (ORCC vs. TT = 0.37 (95%CI = 0.15-0.93), P heterogeneity = 0.569; I (2) = 0 %) polymorphisms might influence the prognosis of patients with osteosarcoma [1]. The meta-analysis results are encouraging. Nevertheless, some deficiencies still existed that we would like to raise.

Comparison of methods for staining microvessels in bone.

Detection of microvessels is critical for studying bone tissue. We developed an intravascular ink-based method coupled with Van Gieson (VG) staining and compared it with other commonly used methods for capillary visualization. The ink perfusate was formulated as 10% ink, 10% formaldehyde and 20% mannitol. The ink solution was perfused into a healthy goat and the tibia was subjected to decalcification, dehydration, paraffin embedding, de-waxing and staining to observe microvessels. Angiogenesis was assessed by vascular area image analysis and the hematoxylin and eosin (HE), Masson, and VG staining techniques were compared to determine the reliability of these methods for counting microvessels. We found that HE, Masson, and VG staining produced poor contrast between the microvessels and surrounding tissues. By contrast, ink coupled with VG staining permitted clear discrimination between the microvessels and surrounding tissues. Our results indicate that ink-VG staining could be more useful than other methods for detecting tissue microvessels.

[Clinical observation of anterior bone graft fusion and internal fixation to treat adjacent multivertebral tuberculosis in one-stage].

OBJECTIVE: To evaluate the method and effectiveness of anterior focus clearance with autograft bone fusion and internal fixation in treating of adjacent multivertebral tuberculosis in one-stage. METHODS: Between March 2007 and September 2009, 8 cases of thoracic vertebra tuberculosis were treated. Of 8 cases, 6 were male and 2 were female, aged 32 years on average (range, 20-42 years). The disease duration ranged from 8 to 14 months (mean, 10.2 months). Affected vertebrae included thoracic vertebrae in 35 cases and lumbar vertebrae in 11 cases; 5 vertebrae were involved in 4 cases, 6 vertebrae in 3 cases, and 8 vertebrae in 1 case. According to Frankel classification, there were 2 cases of grade C, 4 cases of grade D, and 2 cases of grade E. All patients had different kyphosis with the Cobb angle of (25.1 +/- 6.6) degrees. All patients received antituberculous therapy 4-6 weeks preoperatively; after complete clearance lesions, autograft bone fusion and internal fixation were performed, and then antituberculous therapy was given for 18 months. RESULTS: All incisions healed by first intention. Eight patients were followed up 18-48 months (mean, 29 months). According to JIN Dadi et al. criterion, 7 cases recovered after first operation, 1 case of relapsed tuberculosis with sious was cured after re-focus clearance. The Cobb angle was (19.5 +/- 4.2) degrees at 7 days after operation and was (22.3 +/- 3.6) degrees at last follow-up, showing significant differences when compared with the preoperative value (P < 0.05). The nerve function of all cases were classified as Frankel grade E. CT scan showed bone graft fusion at 6-8 months after operation. No loosening or displacement of grafted bone and internal fixation occurred during follow-up. CONCLUSION: The treatment of adjacent multivertebral tuberculosis by anterior focus clearance, intervertebral autograft, and internal fixation in one-stage is effective. Anterior bone fusion and internal fixation in one-stage can correct kyphosis effectively and rebuild spinal stability, so it is a good choice for surgical treatment of adjacent multivertebral tuberculosis.

Biomechanical researches on tissue engineering bone constructed by deproteinated bone.

OBJECTIVE: To study biomechanical changes of newly formed bones 24 weeks after repairing large defects of long bones of goats using heterogeneous deproteinated bone (DPB) prepared by modified methods as an engineering scaffold. METHODS: According to a fully randomized design, 18 goats were evenly divided into three groups: normal bone control group (Group A), autologous bone group (Group B) and experimental group (Group C). Each goat in Groups B and C were subjected to the periosteum and bone defect at middle-lower part of the right tibia (20% of the whole tibia in length), followed by autologous bone or DPB plus autologous MSCs + rhBMP2 implantation, respectively and semi-ring slot fixation; while goats in Group A did not perform osteotomy. At 24 weeks after surgery, biomechanical tests were carried out on the tibias. RESULTS: At 24 weeks after surgery, the results of anti-compression test on tibias in three groups were recorded by a functional recorder presented as linear pressure-deformation curve. The shapes of the curves and their change tendency were similar among three groups. The ultimate pressure values were 10.74 MPa+/-1.23 MPa, 10.11 MPa+/-1.35 MPa and 10.22 MPa+/-1.32 MPa and fracture compression rates were 26.82%+/-0.87%, 27.17%+/-0.75% and 28.22%+/-1.12% in Groups A, B and C, respectively. Comparisons of anti-compression ultimate pressures and fracture compression rates among three groups demonstrated no significant difference (P(AB) equal to 0.415, P(BC) equal to 0.494). Three-point anti-bend test on tibias was recorded as load-deformation curves, and the shapes of the curves and their change tendency were similar among three groups. The ultimate pressure values of the anti-bend test were 481.52 N+/-12.45 N, 478.34 N+/-14.68 N and 475.62 N+/-13.41 N and the fracture bend rates were 2.62 mm+/-0.12 mm, 2.61 mm+/-0.15 mm and 2.81 mm+/-0.13 mm in Groups A, B and C, respectively. There was no significant difference between groups (P(AB) equal to 0.7, P(BC) equal to 0.448). The ultimate anti-torsion torque values were 6.55 Nm+/-0.25 Nm, 6.34 Nm+/-0.18 Nm and 6.42 Nm+/-0.21 Nm and fracture torsion rates were 29.51 degree+/-1.64degree, 28.88 degree+/-1.46 degree and 28.81 degree+/-1.33 degree in Groups A, B and C, respectively. There was no significant difference between groups (P(AB) equal to 0.123, P(BC) equal to 0.346). CONCLUSIONS: The biomechanical characteristics of newly formed bones from heterogeneous DPB for repairing large segmental long bone defect are comparable to those of normal bones and autologous bones. DPB has the potential for clinical usage as bone graft material.

Properties of deproteinized bone for reparation of big segmental defect in long bone.

OBJECTIVE: To explore suitable scaffold material for big segmental long bone defect by studying the properties of the prepared deproteinized bone. METHODS: Cancellated bone were made as 30 mm x mm x 3 mm bone blocks from inferior extremity of pig femur along bone trabecula. The deproteinized bone was prepared with an improved method. Their morphological features, components, cell compatibility, mechanical and immunological properties were investigated respectively. RESULTS: Deproteinized bone maintained natural reticular pore system. The main organic material is collagen I and inorganic composition is hydroxyapatite. It has good mechanical properties, cell adhesion rate and histocompatibility. CONCLUSION: This deproteinized bone can be applicable as scaffold for reparation of big segmental defect in long bone.

[Spinal fusion of lumbar intertransverse process by using tissue engineered bone with xenogeneic deproteinized cancellous bone as scaffold].

OBJECTIVE: To study the properties of the xenogeneic deproteinized cancellous bone used as a scaffold in the bone tissue engineering and its application to the spinal fusion of the lumbar intertransverse process in a goat. METHODS: The deproteinized bone was derived from an adult pig's femoral cancellous bone through the physical and chemical treatments. Its morphological features, constituting components, and biomechanical properties were examined by the scanning electron microscopy, X-ray diffraction analysis, and mechanical experimental instrument. The cell-material complex was observed under the inverted phase contrast microscope to evaluate the adhesion and the growth of the osteoblasts. The experimental model of the spinal fusion of the lumbar intertransverse process was produced in 12 male goats aged 6-8 months, which were divided into two groups. In Group A, the tissue engineered bone constructed by the xenogeneic deproteinized cancellous bone, the recombinant human bone morphogenetic protein 2, and the mesenchymal stem cells was used for the spinal fusion; however, in Group B the auto-ilium was used. The samples were harvested at 4, 8 and 12 weeks postoperatively, and a series of examinations were performed, including the radiography and the histomorphological assay. RESULTS: The deproteinized cancellous bone had a natural pore network system, with an aperture ranging in size from 200 to 500 microm, containing a main organic material of collagen and the inorganic material of hydroxyapatite. So, the deproteinized cancellous bone had a good mechanical strength and a good histocompatibility. In Group A, the X-ray examination at different timepoints postoperatively showed that at 4 weeks, the bridging areas of all the fusion sites were not clear, especially on the internal side; at 8 weeks, the upper and lower bridged parts had a narrowed gap, with formation of much continuous bony callus; at 12 weeks, a complete fusion occurred. In the early stage, the material density was slightly lower in Group A than in Group B, but at 12 weeks the density was almost the same in both the groups. Histological examination in the transplant area showed that at 4 weeks in Group A there was a new bone formation in a multipoint way; at 8 weeks, a "sandwich-shaped" new bone was crossed with the transplanting materials; and at 12 weeks, a medullary cavity was remodeled and a new cancellous bone was formed. The osteogenic process of the tissue engineered bone constructed by the xenogeneic deproteinized cancellous bone scaffold was almost the same as the auto-ilium osteogenesis. CONCLUSION: The xenogeneic deproteinized cancellous bone is a good material in the bone tissue engineering, which can be used as an osteogenesis scaffold and provide a stable environment for revascularization and osteoblastic differentiation.

Preparation and physicochemical properties of scaffold materials of heterogeneous deproteinized bone.

OBJECTIVE: To prepare and observe the physicochemical properties of scaffold materials of heterogeneous deproteinized tissue-engineered bone. METHODS: Deproteinized bone was made through a series of physicochemical treatments in pig ribs and analyzed with histological observation, scanning electron microscopy, infrared spectrum, X-ray diffraction and energy dispersive analysis, Kjeldahl determination and mechanics analysis. RESULTS: Interstitial collagen fiber was positive and mucin was negative in deproteinized bone, but, both were positive in fresh bone. Deproteinized bone maintained natural pore network. Its pore size was 472.51 micromolar+/-7.02 micromolar and the porosity was 78.15%+/-6.45%. The results of infrared spectrum showed that collagen was present in deproteinized bone. Both fresh and deproteinized bone had curve of hydroxyapatite. The Ca/P ratios were 1.71+/-0.95 and 1.68+/-0.76 (P larger than 0.05), and the protein contents were 26.6%+/-2.23% and 19.1%+/-2.14% (P less than 0.05) in fresh and deproteinized bone, respectively. There was no significant difference of destruction load under compression and maximal destruction load between fresh and deproteinized bone (P larger than 0.05). The elastic modulus was higher in deproteinized bone than that in fresh bone (P less than 0.05). CONCLUSIONS: Physicochemical properties and mechanic strength of deproteinized tissue-engineered bone meet the demands of ideal scaffold materials. But, its immunogenicity should be observed through further experiments for its clinical applications.