Clinical and Radiographic Features of the Atlantoaxial Dislocation Associated With Kashin-Beck Disease.

OBJECTIVES: Keshin-Beck disease (KBD) is a particular type of osteoarthritis that affects many joints. However, the deformity of atlantoaxial joint has been rarely reported in KBD, and therefore its clinical and radiograph features have not been identified. METHODS: We reviewed data in 14 patients who were diagnosed with atlantoaxial dislocation (AAD) in KBD at our institution. The demographic data, clinical history, imaging data, operative data, and Japanese Orthopaedic Association score were collected for evaluation. RESULTS: The mean age at presentation was 50 ± 1.7 years old. The most common features of AAD in KBD were the osteoarthritis, characterized by hypertrophic dens and anterior arch of the atlas. The average inner anteroposterior diameter (IAPD) of C1 was 28 ± 3.5 mm and the average spinal canal diameter was 14 ± 3.3 mm, which were respectively lower than the control level. Five patients had severe C1 stenosis (IAPD < 26mm). Separated odontoid process, like os odontoideum, was seen 9 patients. The tip of dens fused to C1 was observed in 4 patients; 12 patients had high-riding vertebral artery; and 5 patients had severe C1 stenosis, and they underwent C1 laminectomy with C1-C2 interarticular fusion or occipital-cervical fusion. All the patients displayed neurologic improvement after surgery. CONCLUSIONS: The atlantoaxial level could be affected by KBD, which may lead to typical abnormalities and cause AAD. A C1 laminectomy with an C1-C2 interarticular fusion or occipital-cervical fusion is recommended for the patient with severe stenosis.

7,8-Dihydroxyflavone suppresses proliferation and induces apoptosis of human osteosarcoma cells.

Recent studies suggest that 7,8-dihydroxyflavone (7,8-DHF) inhibits the development of several tumors. However, its role in osteosarcoma (OS) remains unknown. This study was designed to investigate the effects and underlying mechanisms of 7,8-DHF that may influence OS development. Human OS cell lines (U2OS and 143B) were treated with 7,8-DHF; cell viability and cell migration were assessed by methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay and wound-healing assay, respectively; and cell death and apoptosis were evaluated by LIVE/DEAD staining and terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) assay, respectively. Reactive oxygen species production was measured using 2,7-dichlorodihydrofluorescein diacetate probe. Akt, Bcl-xL/Bcl-2 asociated death promoter (Bad), p38 mitogen-activated protein kinase (MAPK), extracellular regulated protein kinase (ERK), and c-Jun N-terminal kinase (JNK) expression and their respective phosphorylation levels were detected by western blot analysis. We found that 7,8-DHF reduced cell viability in a dose-dependent manner and also promoted apoptosis, inhibited migration, and induced oxidative stress in OS cells. Moreover, 7,8-DHF inhibited Akt, Bad, and p38MAPK, but activated ERK and JNK signals. In summary, our results suggest that 7,8-DHF inhibits OS progression, possibly by regulating Akt/Bad and MAPK signaling. These findings provide new evidence for the pharmacological effects of 7,8-DHF that may improve drug therapy for OS patients.

Nuciferine prevents bone loss by disrupting multinucleated osteoclast formation and promoting type H vessel formation.

Recently, type H vessels were reported to couple angiogenesis and osteogenesis during osteoclastogenesis, and tartrate-resistant acid phosphatase (Trap)+ preosteoclasts were found to secrete increased PDGF-BB to promote type H vessel formation. Therefore, utilization of type H vessels may be a strategy to treat diseases involving bone loss. In the present study, we found that nuciferine, a natural bioactive compound, has various effects, including inhibiting osteoclastogenesis and promoting type H vessel formation. Nuciferine inhibited osteoclastogenesis and bone resorption but increased the relative number of Trap+ preosteoclasts. Nuciferine restrained the expression of osteoclast-specific genes and proteins, promoted PDGF-BB production and potentiated related angiogenic activities by inhibiting the MAPK and NF-κB signaling pathways in vitro. We confirmed the bone-protective effects of nuciferine in ovariectomized mice and found that nuciferine treatment increased the PDGF-BB concentration and the number of type H vessels in the femur. In conclusion, our results demonstrated that nuciferine can decrease multinucleated osteoclast formation and promote type H vessel formation through preservation of Trap+ preosteoclasts via inhibition of the MAPK and NF-κB signaling pathways and may be an excellent agent for the treatment of diseases involving bone loss.

Effects of unfractionated heparin and rivaroxaban on the expression of heparanase and fibroblast growth factor 2 in human osteoblasts.

Long-term treatment with anticoagulants may contribute to osteoporosis. Although unfractionated heparin and rivaroxaban have adverse effects on bone microstructure and function in adult rats, the underlying mechanism remains to be elucidated. Heparanase (HPSE) and fibroblast growth factor (FGF)2 are important signals in bone formation and fracture healing. Therefore, the present study was designed to investigate the effects of unfractionated heparin and rivaroxaban on the expression of HPSE and FGF2 in human osteoblasts. Human osteoblasts were treated with unfractionated heparin (0.5-50 IU/ml) or rivaroxaban (0.13­13 µg/ml) for different durations. Plasmids encoding HPSE and FGF2 were transfected into osteoblasts, and cell viability was assessed using MTT assays, with mRNA and protein expression levels determined using reverse transcription­quantitative polymerase chain reaction and western blot analyses, respectively. Osteoblast growth was significantly inhibited by treatment with unfractionated heparin (50 IU/ml) or rivaroxaban (13 µg/ml). Unfractionated heparin alone significantly inhibited the expression of HPSE and FGF2, whereas rivaroxaban inhibited the expression of FGF2 without affecting that of HPSE. Furthermore, the overexpression of HPSE or FGF2 significantly reversed the inhibitory effects of unfractionated heparin and rivaroxaban on osteoblasts. These findings suggested that HPSE and FGF2 signals were involved in the detrimental role of unfractionated heparin and rivaroxaban in human osteoblasts, providing novel information on the side effects of anticoagulants.

FGF21 ameliorates the neurocontrol of blood pressure in the high fructose-drinking rats.

Fibroblast growth factor-21 (FGF21) is closely related to various metabolic and cardiovascular disorders. However, the direct targets and mechanisms linking FGF21 to blood pressure control and hypertension are still elusive. Here we demonstrated a novel regulatory function of FGF21 in the baroreflex afferent pathway (the nucleus tractus solitarii, NTS; nodose ganglion, NG). As the critical co-receptor of FGF21, ß-klotho (klb) significantly expressed on the NTS and NG. Furthermore, we evaluated the beneficial effects of chronic intraperitoneal infusion of recombinant human FGF21 (rhFGF21) on the dysregulated systolic blood pressure, cardiac parameters, baroreflex sensitivity (BRS) and hyperinsulinemia in the high fructose-drinking (HFD) rats. The BRS up-regulation is associated with Akt-eNOS-NO signaling activation in the NTS and NG induced by acute intravenous rhFGF21 administration in HFD and control rats. Moreover, the expressions of FGF21 receptors were aberrantly down-regulated in HFD rats. In addition, the up-regulated peroxisome proliferator-activated receptor-γ and -α (PPAR-γ/-α) in the NTS and NG in HFD rats were markedly reversed by chronic rhFGF21 infusion. Our study extends the work of the FGF21 actions on the neurocontrol of blood pressure regulations through baroreflex afferent pathway in HFD rats.

Aquaporin 3 protects against lumbar intervertebral disc degeneration via the Wnt/ß-catenin pathway.

Previous studies have demonstrated that the expression of aquaporin 3 (AQP3), a water channel which promotes glycerol permeability and water transport across cell membranes, is reduced in degenerative lumbar intervertebral disc (IVD) tissues. However, the role of AQP3 in the pathogenesis of IVD degeneration has not recieved much scholarly attention. The objective of the present study was to investigate the effect of AQP3 on cell proliferation and extracellular matrix (ECM) degradation in human nucleus pulposus cells (hNPCs) using gain-of-function and loss-of-function experiments, and to determine whether Wnt/ß-catenin signaling is involved in the effect of AQP3 on IVD degeneration. hNPCs were transfected with the AQP3-pcDNA3.1 plasmid or AQP3 siRNA to overexpress or suppress AQP3. An MTT assay was performed to determine cell proliferation, and we found that AQP3 promoted hNPC proliferation. The expression of aggrecan, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)4 and ADAMTS5 was detected using western blot analysis, to examine the effect of AQP3 on ECM degradation in hNPCs. The results revealed that AQP3 inhibited ECM degradation in hNPCs. In addition, we found that Wnt/ß-catenin signaling was suppressed by AQP3. However, the effect of AQP3 on hNPC proliferation and ECM degradation was reversed by treatment with lithium chloride, a known activator of Wnt/ß­catenin signaling. In conclusion, using in vitro and in vivo tests, we have reported for the first time, to the best of our knowledge, that AQP3 exerts protective effects against IVD degeneration, and these are effected, at least partially, through the inhibition of Wnt/ß-catenin signaling.

Comparison of the effects of heparin and the direct factor Xa inhibitor, rivaroxaban, on bone microstructure and metabolism in adult rats.

AIM: Deep venous thrombosis is a significant complication following surgery, and is associated with high morbidity and mortality in adults. The direct factor Xa inhibitor, rivaroxaban, is used to prevent venous thromboembolism in patients suffering from trauma and joint arthroplasty. The present study compared the effects of rivaroxaban and heparin on bone microstructure and metabolism in adult rats. MATERIALS AND METHODS: Twenty-four Wistar rats were divided into sham, rivaroxaban and heparin groups. Rivaroxaban (1.5 mg·kg(-1)·d(-1)) and heparin (2 IU·g(-1)·d(-1)) were administered for 4 weeks. To assess changes in bone metabolism, serum calcium and phosphorus levels, and bone formation and resorption markers were examined. Micro-CT analysis was used to examine the microstructure of both trabecular and cortical bone. Dual energy X-ray absorptiometry was employed to detect bone mineral density (BMD). RESULTS: Serum phosphorus levels were significantly lower in both rivaroxaban (1.33 ± 0.07 mmol/L) and heparin (1.33 ± 0.21 mmol/L) rats than in sham rats (1.71 ± 0.14 mmol/L). Activity and levels of bone formation markers, bone-specific alkaline phosphatase (BAP) and type I procollagen N-terminal pro-peptide (PINP), were 32.4 and 38.2% lower in heparin-treated rats than in sham rats. Bone resorption markers, pyridinoline (PYD) and deoxypyridinoline (DPD), were 20.1 and 34.3% higher in heparin-treated rats than in sham rats, respectively. By contrast, rivaroxaban only resulted in a decrease PINP levels. Bone volume fraction (BV/TV) decreased by 23.5 and 20.5% from those in sham rats, while trabecular separation (Tb.Sp) increased by 28.2 and 16.3% in trabecular bone of heparin- and rivaroxaban-treated rats, [corrected] respectively. Moreover, the microstructure of cortical bone and BMD were negatively affected by heparin but not by rivaroxaban. CONCLUSION: Rivaroxaban leads to fewer adverse effects on bone microstructure than heparin.

[Clinical application of a novel posterior lumbar fusion method and the short-term observation of its effect].

OBJECTIVE: To increase local blood supply of bone graft, a novel posterior lumbar spine fusion method with orthotopic paraspinal muscle-pediculated bone flaps was constructed, and the fusion rate and clinical effect.were observed. METHODS: From June 2007 to December 2010, 117 patients of lumbar spinal stenosis or lumbar destabilization treated with the novel posterior lumbar fusion method were studied, 49 males and 68 females, aged from 40 to 77 years, average 61.5 years. Clinical effect was evaluated by JOA and VAS score preoperatively and postoperatively, and the fusion result was evaluated by three-dimensional CT reconstruction postoperatively. RESULTS: Seventeen cases lost of follow up, the rest were followed up from 7 to 38 months, average 19 months. There was significant difference between pre- and postoperative JOA and VAS score (P < 0.01), the preoperative JOA score was 10.3 ± 1.9, and 25.4 ± 4.2 at the latest follow-up, the improvement rate was 81.0% ; the preoperative VAS score was 8.5 ± 0.8, and 2.3 ± 0.4 at the latest follow-up. The three-dimensional CT reconstruction showed that 126 of the 133 segments formed solid fusion in 100 patients who completed the follow-up, the fusion rate was 94.7%. CONCLUSION: The novel posterior lumbar fusion method make the bone graft position more precise, stable and increases the fusion rate, which can effectively reduce pseudarthrosis and have a promising clinical effect.

[Combined use of autologous micro-morselized bone with bone morphogenetic protein and type I collagen graft in repairing rabbit bone defects].

OBJECTIVE: To study the effect of combined use of autologous micro-morselized bone with bone morphogenetic protein(BMP) and type I collagen graft on the treatment of segmental bone defects. METHODS: The bulk bone of rabbit iliac crest was ground into micro-morselized bone, which was combined with BMP and type I collagen. The model of 1.5 cm bone defect was established in the middle shaft of the radius. Fifty-six rabbits were assigned to four repairing methods: autologous micro-morselized bone graft with BMP and type I collagen, autologous micro-morselized bone graft with type I collagen, autologous micro-morselized bone graft alone, and control group. The defect-repairing capability of each group was assessed by radiographic, histological, bone densitometry and biomechanical studies. RESULTS: X-ray manifested that at the end of 8 weeks after operation, the bone defect treated with autologous micro-morselized bone graft with BMP and type I collagen was repaired completely, and at the end of 12 weeks after operation the bone defect treated with autologous micro-morselized bone and type I collagen was cured completely, but the bone defect treated with autologous micro-morselized alone was completely repaired. No healing was found in the control group. In the bone densitometry detection, the material with BMP exhibited the strongest defect-repairing capability in terms of amount increased and quality of the new bone at the end of 8 weeks and 12 weeks. The group with BMP has the best mechanical strength of all groups at the end of 12 weeks. CONCLUSION: Autologous micro-morselized bone graft with BMP/type I collagen and autologous micro-morselized bone graft with type I collagen prove to be effective in repairing segmental bone defects. The autologous micro-morselized bone combined BMP and type I collagen is an excellent bone repairing material considering the satisfactory osteogenesis, osteo-conduction, and osteo-induction seen in this method.

[Clinical application and relative examination of morselized bone].

OBJECTIVE: To review progress of clinical application of morselized bone and to investigate relative exploration on it. METHODS: The recent articles on morselized bone in the field of clinic and experimental research were extensively reviewed, and relative examination of morselized bone referring to method and mechanism were investigated carefully. RESULTS: Morselized bone worked well clinically, especially in revision of artificial total hip joint, and it was proved effective with lots of advantages. CONCLUSION: Morselized bone functions well clinically. Although its mechanism requires a further research, it still has a promising value in clinical application.