Mitsumasa Hayashida

CCAAT/ENHANCER binding protein β mediates expression of matrix metalloproteinase 13 in human articular chondrocytes in inflammatory arthritis

OBJECTIVE To determine the function of CCAAT/enhancer binding protein beta (C/EBPbeta) in the expression of matrix metalloproteinase 13 (MMP-13) in chondrocytes in inflammatory arthritis. METHODS Cartilage obtained from patients with rheumatoid arthritis and osteoarthritis was immunostained for expression of C/EBPbeta or MMP-13. Interleukin-1beta- or tumor necrosis factor alpha (TNFalpha)-stimulated chondrocytes were subjected to Western blotting and real-time reverse transcriptase-polymerase chain reaction (RT-PCR). MMP-13 promoter assays were conducted, and the C/EBPbeta response element was characterized by deletion and mutation analysis. C-28/I2 cells were treated with TNFalpha and subjected to chromatin immunoprecipitation (ChIP) assays. Finally, C/EBPbeta-liver-enriched activator protein (LAP) was overexpressed in C-28/I2 cells or cartilage tissues, and MMP-13 expression was analyzed. RESULTS C/EBPbeta and MMP-13 expression was colocalized in chondrocytes in arthritic cartilage. MMP-13 promoter activity was stimulated by C/EBPbeta overexpression in a dose-dependent manner. Luciferase assays revealed that a -981-bp promoter had the greatest activity, while deletion to -936 bp strongly diminished promoter activity. Luciferase activity was repressed to basal levels by mutations in potential C/EBP binding sites. The stimulatory effects of C/EBPbeta overexpression were diminished by mutation. ChIP assays revealed that TNFalpha treatment enhanced the binding of C/EBPbeta to the MMP-13 promoter. When C/EBPbeta-LAP was overexpressed in C-28/I2 cells, endogenous MMP-13 expression was stimulated up to 32-fold as detected by real-time RT-PCR. Furthermore, following adenoviral overexpression of C/EBPbeta-LAP in organ culture of articular cartilage, stimulation of MMP-13 was also detected by immunohistochemistry. CONCLUSION C/EBPbeta directly binds to the MMP-13 promoter region and stimulates the expression of MMP-13 in chondrocytes in inflammatory arthritis.

CCAAT/enhancer binding protein β regulates expression of matrix metalloproteinase-3 in arthritis

Objectives To investigate whether CCAAT/enhancer binding protein β (C/EBPβ) mediates the expression of matrix metalloproteinase-3 (MMP-3) and aggrecanases in arthritis. Methods Localisation of C/EBPβ and MMP-3 in synovium and cartilage from patients with rheumatoid arthritis and osteoarthritis was determined by immunohistochemistry. Cell lines SW982, C28/I2 and human fibroblast-like synoviocytes stimulated by interleukin 1β (IL-1β) were subjected to western blotting and quantitative PCR. Overexpression of C/EBPβ by adenovirus was performed in cells and organ culture of normal cartilage. Knockdown of C/EBPβ by small interference RNA was performed in cells. Activity of the human MMP-3 and aggrecanase-2 ADAMTS-5 (a disintegrin and metalloproteinase with thrombospondin motifs) promoters was analysed by a luciferase assay. To determine whether C/EBPβ directly binds to the MMP-3 or ADAMTS-5 promoter,a chromatin immunoprecipitation assay was performed. Results Immunohistochemistry showed that C/EBPβ and MMP-3 were co-localised in arthritic synovium and cartilage. Western blots revealed increased C/EBPβ expression in cells treated with IL-1β. Expression of MMP-3, MMP-13 and ADAMTS-5 mRNA was significantly increased by the overexpression of C/EBPβ. C/EBPβ stimulated MMP-3 expression and induced matrix degradation in cartilage explants. C/EBPβ knockdown reduced MMP-3 and ADAMTS-5 expression. C/EBPβ stimulated the 2011 bp MMP-3 promoter and the 1768 bp ADAMTS-5 promoter in a dose-dependent manner. Deletion and mutation analysis of the MMP-3 promoter showed that the C/EBPβ core responsive element was located between −108 bp and −100 bp. The chromatin immunoprecipitation assay showed that C/EBPβ was directly bound to MMP-3 and ADAMTS-5 promoters. Conclusions These data demonstrate that C/EBPβ is involved in expression of MMP-3 and ADAMTS-5 in arthritic synovium and cartilage.

Sequential changes of ascending myelopathy after spinal cord injury on magnetic resonance imaging: a case report of neurologic deterioration from paraplegia to tetraplegia

BACKGROUND CONTEXT Marked neurologic deterioration within a few days of traumatic spinal cord injury, known as subacute posttraumatic ascending myelopathy, is rare. Although several hypotheses regarding the pathogenesis of this condition have been proposed, the details remain elusive. PURPOSE To report a case of ascending myelopathy in which a series of magnetic resonance images (MRIs) taken through the course of the illness helped follow the course of the disease and discuss possible pathogenesis. STUDY DESIGN Case report and review of the literature. PATIENT SAMPLE A 75-year-old woman involved in a motor vehicle collision sustained a fracture dislocation of T7-T8 with complete paraplegia below T8. METHODS Neurologic examination and radiologic imaging taken by various means. RESULTS Posterior surgical stabilization was performed 18 hours after the injury. Both the surgical and postsurgical courses were uneventful. Four days after the injury, however, the patient reported feeling a tingling sensation in the right-hand fingers and gradually suffered from motor weakness of the upper extremities, deteriorating within a few hours to complete tetraplegia and ventilator dependence. Subsequent cervicothoracic MRI showed abrupt cord swelling with abnormal areas of signal intensity in the cervical and upper thoracic spinal cord during the interval between the onset of tingling and the development of motor paralysis in the arms. On the 20th postsurgical day, an area of hypointensity within the region of high intensity was observed on T2-weighted MRIs, indicating intramedullary spinal cord hemorrhage. CONCLUSIONS Our MRI findings suggest that systemically increased intraspinal pressure resulting from the impairment of spinal venous drainage is involved in the pathogenesis of ascending myelopathy. Although ascending myelopathy is often thought to be partly reversible, persisting increase of the intraspinal pressure may result in intramedullary hemorrhage and irreversible neurologic deficit.

Dumbbell Scoring System: A New Method for the Differential Diagnosis of Malignant and Benign Spinal Dumbbell Tumors

Study Design. Retrospective diagnostic analysis. Objective. The aim of the study was to establish a new scoring system, the dumbbell scoring system (DSS), for preoperative evaluation of the malignant potential of spinal dumbbell tumors (SDTs). Summary of Background Data. Among SDTs, benign tumors such as schwannomas occur frequently, whereas malignant SDTs, including malignant peripheral nerve sheath tumors, are uncommon. No scoring system has been developed to preoperatively diagnose the malignant potential of SDTs. Methods. We retrospectively reviewed the records of 59 consecutive patients with SDTs. The following imaging features were recorded: tumor size, tumor shape, tumor boundary, pattern of enhancement of intratumoral lesions (homogeneous or heterogeneous), cyst formation in the tumors on magnetic resonance imaging, and enlargement of neural foramina and scalloping or osteolytic destruction of surrounding bones on computed tomography. The prevalence of characteristic imaging features in malignant and benign SDTs were evaluated, and appropriate cut-off points for the DSS score were obtained using receiver operating characteristics. Results. Twenty cases were confirmed to be malignant tumors. Pathological diagnoses of the malignant SDTs were as follows: 11 cases of malignant peripheral nerve sheath tumor; 3 cases of malignant lymphoma; and 1 case each of extraskeletal Ewing sarcoma, hemangiopericytoma, hemangioendothelioma, malignant myoepithelioma, neuroblastoma, and plasmacytoma. The DSS was based on four characteristic imaging features confirmed as significant predictors of malignant SDTs, namely, maximal diameter greater than 5 cm, irregularly lobulated tumor, tumor boundary indistinguishable from surrounding tissues, and osteolytic bone destruction. Malignant SDTs showed a higher DSS score (median 5.5 points) than did benign SDTs (median 0 point). The optimum cut-off value for the DSS score was 3 points, and the sensitivity and specificity for the diagnosis of malignant SDTs were 90% and 84.6%, respectively. Conclusion. This scoring system may be helpful for preoperative decision making. If the DSS score is equal to or higher than 3, biopsies was recommended to confirm the histological diagnosis. Level of Evidence: 4

Dedifferentiated chondrosarcoma of the cervical spine: a case report

Dedifferentiated chondrosarcoma (DDCS) is a rare and aggressive bone tumor with poor prognosis. Primary DDCS of the mobile spine is extremely rare, particularly in the cervical spine. We herein describe a first case of cervical DDCS in an 81-year-old male presenting with a slowly growing mass. Radiographs showed an expansion of the cortical contour of the C2 lamina and a soft tissue mass with punctate calcification. Magnetic resonance imaging demonstrated a lobulated lesion expanding over the entire lamina and pedicles of C2 with the tumor protuberant to the adjacent soft tissue. A complete tumor resection was performed. Histologically, the majority of the tumor was a low-grade chondrosarcoma component. However, atypical spindle cells that had proliferated in a fascicular pattern with a collagenous stroma, mimicking fibrosarcoma, were focally observed without a transitional zone, and these features confirmed that the tumor was DDCS.

Spinal hyperostosis as an important sign indicating spine injuries on postmortem computed tomography

Although spine injuries are not always detectable on postmortem computed tomography (PMCT), spinal hyperostosis, an important risk factor for spine injury, is relatively easily detectable on PMCT. We therefore examined the utility of the detection of spinal hyperostosis on PMCT as an indicator of spine injury. Full-body PMCT images of 88 autopsy cases with a bruise on the face or forehead but no identifiable skull fracture were reviewed prior to autopsy for the identification and classification of spinal hyperostosis. Spine injuries were observed in 56.0% of cases with spinal hyperostosis and 1.6% of cases without spinal hyperostosis. Among the cases with spinal hyperostosis, spine injuries were observed in 66.7% of cases at stage 2 or 3 and in 88.9% of cases at stage 3. Spine injuries were diagnosed on PMCT in 33.3% of cases prior to autopsy. A significant association was found between spinal hyperostosis and presence of spine injury that cannot be detected on PMCT, indicating that the identification of spinal hyperostosis on PMCT may assist in detecting spine injuries. This finding suggests that investigation of the presence of spine injury based on the identification of spinal hyperostosis on PMCT may assist in determining the correct cause of death by autopsy.

Experimental mouse model of lumbar ligamentum flavum hypertrophy

Lumbar spinal canal stenosis (LSCS) is one of the most common spinal disorders in elderly people, with the number of LSCS patients increasing due to the aging of the population. The ligamentum flavum (LF) is a spinal ligament located in the interior of the vertebral canal, and hypertrophy of the LF, which causes the direct compression of the nerve roots and/or cauda equine, is a major cause of LSCS. Although there have been previous studies on LF hypertrophy, its pathomechanism remains unclear. The purpose of this study is to establish a relevant mouse model of LF hypertrophy and to examine disease-related factors. First, we focused on mechanical stress and developed a loading device for applying consecutive mechanical flexion-extension stress to the mouse LF. After 12 weeks of mechanical stress loading, we found that the LF thickness in the stress group was significantly increased in comparison to the control group. In addition, there were significant increases in the area of collagen fibers, the number of LF cells, and the gene expression of several fibrosis-related factors. However, in this mecnanical stress model, there was no macrophage infiltration, angiogenesis, or increase in the expression of transforming growth factor-β1 (TGF-β1), which are characteristic features of LF hypertrophy in LSCS patients. We therefore examined the influence of infiltrating macrophages on LF hypertrophy. After inducing macrophage infiltration by micro-injury to the mouse LF, we found excessive collagen synthesis in the injured site with the increased TGF-β1 expression at 2 weeks after injury, and further confirmed LF hypertrophy at 6 weeks after injury. Our findings demonstrate that mechanical stress is a causative factor for LF hypertrophy and strongly suggest the importance of macrophage infiltration in the progression of LF hypertrophy via the stimulation of collagen production.

A case of superficial siderosis ameliorated after closure of dural deficit detected by MRI-CISS (constructive interference in steady state) imaging

A 64-year-old male developed headache, dizziness, and difficulty hearing, two years after an operation for chronic subdural hematoma due to head injury. These symptoms gradually worsened over the following 15 years. As he showed bloody cerebrospinal fluid (CSF) and marginal hypointensity on the surface of the brain and spinal cord on T2/T2*-weighted MRI, he was diagnosed with superficial siderosis (SS), although the source of the bleeding was unclear and anti-hemorrhagic drugs were ineffective. When he was admitted to our hospital, neurological examination disclosed horizontal gaze-evoked nystagmus, severe bilateral hearing loss, scanning speech, and limb and truncal ataxia. CISS (constructive interference in steady state) MRI detected a dural defect at the Th2-3 level on the anterior side of the spinal canal. On operation, a 2 mm × 6 mm size dural defect with blood clots was found at the Th2-3 level. After closure of the dural defect, bloody CSF became transparent, and his persistent headache, dizziness, and hearing impairment improved. Brain and whole spine MRI, especially CISS imaging, should be considered for detecting the source of bleeding in intractable cases of SS.

The Position of the Aorta Relative to the Vertebrae in Patients With Lenke Type 1 Adolescent Idiopathic Scoliosis.

Study Design. A computed tomography study. Objective. The aim of the study was to clarify the position of the aorta relative to the spine in patients with Lenke type 1 adolescent idiopathic scoliosis. Summary of Background Data. Several authors have examined the position of the aorta in patients with scoliosis; however, their analysis included several types of curve. There is a possibility that the position of the aorta differs according to the scoliosis curve type. Methods. Thirty-eight patients with Lenke type 1 were analyzed. The angle (left pedicle aorta [LtP-Ao] angle) and distance (LtP-Ao distance) from the insertion point of the left pedicle screw to the aorta were measured from T4 through L2. The measured data were evaluated from 4 levels above to 4 levels below the apical vertebra. The difference between lumbar modifiers A and C was examined. Dangerous pedicles, which were defined as those in which the aorta entered the expected area based on the screw direction error and length, were counted from T10 to L2. Results. The aorta was located posterolaterally and adjacent to the vertebra at the middle thoracic level, and anteromedially and distant at the thoracolumbar level. LtP-Ao angle was largest at 1 level above the apical vertebra, and LtP-Ao distance was shortest at 2 levels above. LtP-Ao angle of Lenke 1A was significantly larger than 1C from T11 to L2, and LtP-Ao distance of 1A was significantly shorter than 1C from T11 to L1. When the screw length was 40 mm and the direction error was within 10°, there were a large number of dangerous pedicles at T11, regardless of the lumbar modifier. Conclusion. The direction error has a potential risk of injuring the aorta around the apical vertebra. The selection of screws of the proper length is necessary to avoid a breach of the anterior vertebral wall at thoracolumbar level, especially at T11. Level of Evidence: 3

Instability of the Vertebrae Remains following Balloon Kyphoplasty

Study Design Retrospective cohort study. Objectives The mechanism underlying the pain relief observed following balloon kyphoplasty (BKP) to vertebral compression fractures is reported to involve stabilization of the fractured vertebrae. However, whether fixation of the vertebrae was achieved immediately after BKP has not been investigated. The purpose of this study was to assess fixation of the vertebrae immediately after BKP and whether the instability was related to visual analog scale (VAS) scores. Methods Thirty-eight patients with vertebrae that were evaluated on lateral roentgenkymography within 1 week after BKP were recruited. Instability was defined as a cleft observed between the cement and end plate of the vertebra in the supine position that disappeared in the sitting position, and the posterior wall height of the vertebra was reduced in the sitting position. Results Instability of the vertebrae immediately after BKP was observed in 17 cases. VAS scores improved in all cases, and no significant differences were observed with or without instability. Conclusions The mechanism of rapid pain relief following BKP was not strong fixation but some degree of stabilization or other factors. We suggest that more research is needed about the mechanism of pain relief following BKP in the future.