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Intervertebral disc degeneration proceeds with age and is one of the major causes of lumbar pain and degenerative lumbar spine diseases. However, studies in the field of intervertebral disc biology have been hampered by the lack of reliable cell lines that can be used for in vitro assays. In this study, we show that a chordoma‐derived cell line U‐CH1‐N cells highly express the nucleus pulposus (NP) marker genes, including T (encodes T brachyury transcription factor), KRT19, and CD24. These observations were further confirmed by immunocytochemistry and flow cytometry. Reporter analyses showed that transcriptional activity of T was enhanced in U‐CH1‐N cells. Chondrogenic capacity of U‐CH1‐N cells was verified by evaluating the expression of extracellular matrix (ECM) genes and Alcian blue staining. Of note, we found that proliferation and synthesis of chondrogenic ECM proteins were largely dependent on T in U‐CH1‐N cells. In accordance, knockdown of the T transcripts suppressed the expression of PCNA, a gene essential for DNA replication, and SOX5 and SOX6, the master regulators of chondrogenesis. On the other hand, the CD24‐silenced cells showed no reduction in the mRNA expression level of the chondrogenic ECM genes. These results suggest that U‐CH1‐N shares important biological properties with notochordal NP cells and that T plays crucial roles in maintaining the notochordal NP cell‐like phenotype in this cell line. Taken together, our data indicate that U‐CH1‐N may serve as a useful tool in studying the biology of intervertebral disc. © 2016 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 34:1341–1350, 2016.

Lumbar disc herniation (LDH), degeneration and herniation of the nucleus pulposus of the intervertebral disc (IVD) of the lumbar spine, is one of the most common musculoskeletal diseases. Its etiology and pathogenesis, however, remain unclear. Type XI collagen is important for cartilage collagen formation and for organization of the extracellular matrix. We identified an association between one of the type XI collagen genes, COL11A1, and LDH in Japanese populations. COL11A1, which encodes the alpha 1 chain of type XI collagen, was highly expressed in IVD, but its expression was decreased in the IVD of patients with LDH. The expression level was inversely correlated with the severity of disc degeneration. A single-nucleotide polymorphism (c.4603C--T [rs1676486]) had the most significant association with LDH (P=3.3 x 10(-6)), and the transcript containing the disease-associated allele was decreased because of its decreased stability. These observations indicate that type XI collagen is critical for IVD metabolism and that its decrease is related to LDH.

CSF-1 is a hemopoietic growth factor, which plays an essential role in macrophage and osteoclast development. Alternative splice variants of CSF-1 are synthesized as soluble or membrane-anchored molecules, although membrane CSF-1 (mCSF-1) can be cleaved from the cell membrane to become soluble CSF-1. The activities involved in this proteolytic processing, also referred to as ectodomain shedding, remain poorly characterized. In the present study, we examined the properties of the mCSF-1 sheddase in cell-based assays. Shedding of mCSF-1 was up-regulated by phorbol ester treatment and was inhibited by the metalloprotease inhibitors GM6001 and tissue inhibitor of metalloproteases 3. Moreover, the stimulated shedding of mCSF-1 was abrogated in fibroblasts lacking the TNF-α converting enzyme (TACE, also known as a disintegrin and metalloprotease 17) and was rescued by expression of wild-type TACE in these cells, strongly suggesting that the stimulated shedding is TACE dependent. Additionally, we observed that mCSF-1 is predominantly localized to intracellular membrane compartments and is efficiently internalized in a clathrin-dependent manner. These results indicate that the local availability of mCSF-1 is actively regulated by ectodomain shedding and endocytosis. This mechanism may have important implications for the development and survival of monocyte lineage cells.

The Japanese Orthopaedic Association Committee on Tissue Transplantation and Regenerative Medicine has conducted a nationwide survey of the status of bone grafting in Japan every 5 years from 1985. We report here the status of bone grafting from 2000 to 2004, show the trends in bone grafting from 1985 to 2004, and draw attention to the issues affecting banked bone allografts.Questionnaires devised by the Committee were sent to all educational and training hospitals (2239 institutions) approved by the Japanese Orthopaedic Association.Survey responses were obtained from 1263 institutions (56%). Of these, 875 institutions performed tissue transplantation during this period. A total of 163 564 tissue transplantations were performed, and 134 782 (82.4%) of them were bone grafts. Of the bone grafts, 76 015 (56.4%) were autografts, 53 735 (40%) used a synthetic bone substitute, and 4886 (3.6%) were banked bone allografts. The proportion of synthetic bone substitutes increased, and the proportion of autografts decreased year by year. Synthetic bone substitutes were most frequently used for replacement arthroplasty (31%). Fifty percent of banked bone allografts were performed for joint disorders requiring replacement arthroplasty. During this period, 271 institutions performed banked bone allografts, with 210 preserving allografts in their own institutions. Donor selection criteria, processing and preservation methods, and management of the bone bank were not the same in all banks.Most bone grafts performed in Japan during the four surveys were still autografts. However, the proportion of autografts decreased, and the proportion of synthetic bone substitutes increased. The number of synthetic bone substitutes and banked bone allografts used for replacement arthroplasty increased significantly. However, the total number of banked bone allografts reported in the fourth survey was still low. Quality control of banked bone allografts and management of bone banks were not satisfactory, although they were improved.

Although osteoblasts express the angiogenic protein Angiopoietin 1 (Ang1), the role of Ang1 in bone formation remains largely unknown. Here we report that Ang1 overexpression in osteoblasts driven by the osteoblast-specific 2.3 kb alpha 1 type 1 collagen promoter results in increased bone mass in vivo. In Ang1-transgenic mice (Ang1-Tg), bone volume and bone parameters increased significantly compared with wild-type littermates, although the Ang1 receptor, Tie2 was not expressed in osteoblasts. Tie2 is primarily expressed in vascular endothelial cells, and Ang1-Tie2 signaling is reportedly crucial for angiogenesis. We found that the number of vascular endothelial cells was significantly elevated in Ang1-Tg mice compared with that of wild-type littermates, an increase accompanied by increased alkaline-phosphatase activity, a marker of osteoblast activation. The number of osteoclasts in the bone of Ang1-Tg mice did not differ from wild-type littermates. These results indicate that angiogenesis induced by Ang1 expressed in osteoblasts is coupled with osteogenesis.

Background The project to develop a new Japanese Orthopaedic Association (JOA) score rating system for low back disorders, the JOA Back Pain Evaluation Questionnaire (JOABPEQ), is currently in progress. Part 1 of the study selected 25 “candidateȝ items for use on the JOABPEQ. The purpose of this current Part 2 of the study was to verify the reliability of the questionnaire. Methods A total of 161 patients with low-back disorders of any type participated in the study. Each patient was interviewed twice at an interval of 2 weeks using the same questionnaire. The reliability of the questionnaire was evaluated by determining the extension of the kappa and weighted kappa coefficients. Results Both kappa and weighted kappa were more than 0.50 for all but one item, which was 0.48. The lower 95% confidence interval exceeded 0.4 in all but two items, which was 0.39. This implied that the test–retest reliability of JOABPEQ was acceptable as a measure of outcome. Conclusions The tentative questionnaire of the JOABPEQ with 25 items was confirmed to be reliable enough to describe the quality of life of patients who suffer low back disorders.

We have successfully developed novel “chelate-setting apatite cement” using hydroxyapatite (HAp) particles surface-modified with inositol phosphate (IP6) . The HAp particles surface-modified with IP6 were mixed with water (HAp/water ratio = 1.00/0.50[w/w]) to fabricate apatite cements. We have examined the biocompatibility of the apatite cement using the culture system of MC3T3-E1 cells and the rabbit model. The cell-culture test using MC3T3-E1 cells has shown that the apatite cement has noncytotoxicity. This cement has been implanted into tibiae of rabbits. When tissue response was examined histologically up to 24 weeks, new bone formation was observed around the surface of the cement. The present work demonstrates that this apatite cement is useful as a material for artificial bone grafting.

In spinal cord injury, axonal disruption results in motor and sensory function impairment. The evaluation of axonal fibers is essential to assess the severity of injury and efficacy of any treatment protocol, but conventional methods such as tracer injection in brain parenchyma are highly invasive and require histological evaluation, precluding clinical applications. Previous advances in magnetic resonance imaging technology have led to the development of diffusion tensor tractography (DTT) as a potential modality to performin vivotracing of axonal fibers. The properties and clinical applications of DTT in the brain have been reported, but technical difficulties have limited DTT studies of the spinal cord. In this study, we report the effective use of DTT to visualize both intact and surgically disrupted spinal long tracts in adult common marmosets. To verify the feasibility of spinal cord DTT, we first performed DTT of postmortem marmosets. DTT clearly illustrated spinal projections such as the corticospinal tract and afferent fibers in control animals, and depicted the severed long tracts in the injured animals. Histology of the spinal cords in both control and injured groups were consistent with DTT findings, verifying the accuracy of DTT. We also conducted DTT in live marmosets and demonstrated that DTT can be performed in live animals to revealin vivonerve fiber tracing images, providing an essential tool to evaluate axonal conditions in the injured spinal cord. Taken together, these findings demonstrate the feasibility of applying DTT to preclinical and clinical studies of spinal cord injury.

Retrospective case series. To evaluate our recent treatment strategy for intramedullary spinal cord tumors. Department of Orthopaedic Surgery, Keio University, Japan. We reviewed 68 cases of intramedullary tumors (ependymoma, 33; astrocytoma, 23; hemangioblastoma, 12), treated surgically between 1994 and 2003. There were 42 males and 26 females whose mean age at the time of surgery was 43 years. The mean follow-up period was 6.2 years. The tumor malignancy grade according to the WHO classification was astrocytoma grade I, 3; grade II, 8 (low-grade: 11 cases); grade III, 10; grade IV, 2 (high-grade: 12 cases). All ependymomas were grade II. Three of the 12 hemangioblastomas were associated with von Hippel–Lindau disease. Total excision was achieved in 90% of the ependymomas and functional improvement was obtained when the preoperative neurological deficit was mild. Approximately 50% of low-grade astrocytomas could be totally excised with favorable survival outcomes, suggesting that total excision should be attempted for low-grade astrocytomas. However, total excision of high-grade tumors was difficult and the functional outcomes were poor. Cordotomy should be considered in patients with a thoracic high-grade astrocytoma. Total resection was possible in 92% of hemangioblastoma, and the functional outcomes were good, however, more attention should be paid for tumors with feeding arteries on the ventral side and for those associated with von Hippel–Lindau disease. Predictors of good surgical outcome for intramedullary spinal cord tumors were histological grades of the tumors, surgical margins, and neurological status of the patient before surgery.

We studied the role of monocyte chemoattractant (MCP)-4/CCL13 in the pathogenesis of rheumatoid arthritis (RA). MCP-4 was highly expressed in cartilage from RA patients. Interferon-γ significantly stimulated MCP-4/CCL13 production in human chondrocytes, and this effect was enhanced in combination with interleukin-1β or tumor necrosis factor-α. MCP-4/CCL13 induces the phosphorylation of extracellular signal-regulated kinase in fibroblast-like synoviocytes and activates cell proliferation, and PD98059 completely inhibits these effects. These data suggest that interferon-γ in combination with interleukin-1β/tumor necrosis factor-α activates the production of MCP-4/CCL13 from chondrocytes in RA joints, and that secreted MCP-4/CCL13 enhances fibroblast-like synoviocyte proliferation by activating the extracellular signal-regulated kinase mitogen-activated protein kinase cascade.

Summary Objective Two lateral wedged insoles were compared: one with, and the other without, subtalar strapping. Methods Twenty-one patients (age 58–83, mean 72) with medial knee osteoarthritis (OA) were enrolled. Thirty-seven knees in the patients were divided into three groups based on the Kellgren and Lawrence OA grading system; grades 2 (cases=20), 3 (cases=11), and 4 (cases=6). The subjects were tested during walking barefoot and during walking with a silicon rubber lateral wedged insole with elevation of 10mm attached to a barefoot. Gait analysis was performed on a 10m walkway for each subject under three different walking conditions; barefoot, wearing a conventional insole, and a subtalar strapping insole. Peak knee varus moment during gait was measured under each condition, and compared between the three conditions and between the OA grades. Results On the whole (cases=37), the peak varus moment was significantly reduced by wearing either of the insoles, compared to walking barefoot. The reduction was more obvious with the strapping insole (−13%, P P P =0.0048 and 0.005, respectively). However, no significant difference was detected in severe OA patients (grade 4) between the two types of insoles ( P =0.4). Conclusions Both lateral wedged insoles significantly reduced the peak medial compartment load during gait. The subtalar strapping insole had a greater effect than the conventional insole, particularly in patients with moderate medial knee OA.

BackgroundThe manner of measuring the outcome of cervical myelopathy must be patient-oriented and have sufficient reliability and validity. The current Japanese Orthopaedic Association (JOA) scoring system for cervical myelopathy is widely used but has not met this requirement. The first- and second-round surveys established 24 items for inclusion on a new questionnaire for cervical myelopathy. The purpose of this study (the third-round survey A) was to confirm the reproducibility of patient responses to the selected questions.MethodsA total of 201 patients with cervical myelopathy and with no change of symptoms between the two interviews were included. Each patient was interviewed twice using the same questionnaire at an interval of 4 weeks. The reliability of the questionnaire was evaluated by determining the extension of the weighted kappa coefficients.ResultsThe weighted kappa coefficient for each item was >0.4, confirming that the test–retest reliability was acceptable.ConclusionsThe newly developed JOA Cervical Myelopathy Evaluation Questionnaire was proven to have sufficient reliability.

In soft tissue sarcomas, the diagnosis of malignant fibrous histiocytoma (MFH) has been a very controversial issue, and MFH is now considered to be reclassified into pleomorphic subtypes of other sarcomas. To characterize MFH genetically, we used an oligonucleotide microarray to analyze gene expression in 105 samples from 10 types of soft tissue tumors. Spindle cell and pleomorphic sarcomas, such as dedifferentiated liposarcoma, myxofibrosarcoma, leiomyosarcoma, malignant peripheral nerve sheath tumor (MPNST), fibrosarcoma and MFH, showed similar gene expression patterns compared to other tumors. Samples from those five sarcoma types could be classified into respective clusters based on gene expression by excluding MFH samples. We calculated distances between MFH samples and other five sarcoma types (dedifferentiated liposarcoma, myxofibrosarcoma, leiomyosarcoma, MPNST and fibrosarcoma) based on differentially expressed genes and evaluated similarities. Three of the 21 MFH samples showed marked similarities to one of the five sarcoma types, which were supported by histological findings. Although most of the remaining 18 MFH samples showed little or no histological resemblance to one of the five sarcoma types, 12 of them showed moderate similarities in terms of gene expression. These results explain the heterogeneity of MFH and show that the majority of MFHs could be reclassified into pleomorphic subtypes of other sarcomas. Taken together, gene expression profiling could be a useful tool to unveil the difference in the underlying molecular backgrounds, which leads to a rational taxonomy and diagnosis of a diverse group of soft tissue sarcomas.

IL-1α transgenic (Tg) mice exhibit chronic inflammatory arthritis and subsequent osteopenia, with IL-1-induced GM-CSF playing an important role in the pathogenesis. This study analyzed the mechanisms underlying osteopenia in Tg mice, and the therapeutic effects of the cyclooxygenase-2 inhibitor celecoxib on such osteopenia. Inhibited osteoclast formation was observed in RANKL-treated bone marrow cell (BMC) cultures from Tg mice and coculture of Tg-derived BMCs and wild-type-derived primary osteoblasts (POBs). FACS analysis indicated that this inhibition was attributable to a decreased number of osteoclast precursors within Tg-derived BMCs. Moreover, in coculture of Tg-derived POBs and either Tg- or wild-type-derived BMCs, osteoclast formation was markedly inhibited because Tg-derived POBs produced abundant GM-CSF, known as a potent inhibitor of osteoclast differentiation. Histomorphometric analysis of Tg mice revealed that both bone formation and resorption were decreased, with bone formation decreased more prominently. Interestingly, administration of celecoxib resulted in further deterioration of osteopenia where bone formation was markedly suppressed, whereas bone resorption remained unchanged. These results were explained by our in vitro observation that celecoxib dose-dependently and dramatically decreased osteogenesis by Tg mouse-derived POBs in culture, whereas mRNA expressions of GM-CSF and M-CSF remained unchanged. Consequently, blockade of PGE2 may exert positive effects on excessively enhanced bone resorption observed in inflammatory bone disease, whereas negative effects may occur mainly through reduced bone formation, when bone resorption is constitutively down-regulated as seen in Tg mice.

✓The authors report the case of a 47-year-old woman who harbored a giant cell tumor at the T-5 level. She had undergone curettage of the tumor via a combined anterior and posterior approach at a regional hospital and was later referred to the authors' institution for treatment after the tumor recurred. On examination she exhibited progressive paraparesis and was nonambulatory due to cord compression caused by the tumor, which had invaded the spinal canal and extended to the right paravertebral muscles and right thoracic cavity. A spondylectomy was performed through a single posterior approach. The tumor, together with a portion of the dura mater, pleura, and muscles, was resected en bloc from T-4 to T-6. After resection, spinal reconstruction was performed by placement of an anterior titanium mesh cage as well as posterior pedicle screw and rod instrumentation. The patient's postoperative course was uneventful, and she exhibited substantial neurological recovery and became ambulatory. Two and a half years after surgery, the patient was tumor free. En bloc resection of a recurrent giant cell tumor was successfully achieved through a single posterior approach. This surgical technique can be an effective option for this pathological condition, which is difficult to manage using other conventional treatment options including repeated curettage and radiotherapy.

DC-STAMP is essential for fusion of osteoclasts and foreign body giant cells; however, it is not known whether dc-stamp expression in these two cell types is differentially regulated. Here, we show that dc-stamp expression and cell–cell fusion are regulated in a cell type–specific manner. Introduction: The transcription factors c-Fos and NFATc1 cooperate to regulate osteoclast differentiation, whereas PU.1 and NF-κB are activated in macrophages and osteoclasts or in both cell types. Thus, we asked what role c-Fos, NFATc1, PU.1, and NF-κB played in regulating dendritic cell–specific transmembrane protein (dc-stamp) expression and fusion of osteoclasts and macrophage giant cells. Materials and Methods: Transcriptional activation by c-Fos and NFATc1 was examined by dc-stamp promoter analysis. Multinuclear cell formation was analyzed in cells from c-Fos–deficient mice or in wildtype cells treated with the NFAT inhibitor FK506. The role of DC-STAMP in cell fusion was examined in vitro in a macrophage giant cell formation assay using DC-STAMP–deficient cells. Recruitment of c-Fos, NFATc1, PU.1, and NF-κB to the dc-stamp promoter in osteoclasts and macrophage giant cells was analyzed by chromatin-immunoprecipitation analysis. Results: Both activator protein-1 (AP-1) and NFAT binding sites in the dc-stamp promoter were needed for dc-stamp expression after RANKL stimulation of osteoclasts. dc-stamp expression was induced in osteoclasts and macrophage giant cells, and cells from DC-STAMP–deficient mice failed to form either multinuclear osteoclasts or macrophage giant cells. In contrast, c-Fos is indispensable for dc-stamp expression and cell–cell fusion under conditions favoring in vitro and in vivo induction of osteoclasts but not macrophage giant cells. Consistently, an NFAT inhibitor suppressed multinuclear osteoclast formation but not macrophage giant cell formation. In addition, PU.1 and NF-κB binding sites were detected in the dc-stamp promoter, and both PU.1 and NF-κB were recruited to the dc-stamp promoter after granulocyte-macrophage colony stimulating factor (GM-CSF) + interleukin (IL)-4 stimulation. Conclusions: dc-stamp expression is regulated differently in osteoclasts and macrophage giant cells. c-Fos and NFATc1, both of which are essential for osteoclast differentiation, are needed for dc-stamp expression and cell–cell fusion in osteoclasts, but both factors are dispensable for giant cell formation by macrophages. Because PU.1 and NF-κB are recruited to the dc-stamp promoter after stimulation with GM-CSF + IL-4, dc-stamp transcription is regulated in a cell type–specific manner.

STUDY DESIGN Experimental study on age-related changes in expression of tissue inhibitor of metalloproteinases-3 (TIMP-3) associated with transition from notochordal nucleus pulposus (NP) to fibrocartilaginous NP in rabbit intervertebral disc (IVD). OBJECTIVES To identify roles of notochordal NP in extracellular matrix (ECM) metabolism of IVD. SUMMARY OF BACKGROUND DATA One of most interesting properties of TIMP-3 is to inhibit aggrecanases in addition to matrix metalloproteinases. Balance of aggrecanase/TIMP-3 is critical to maintain homeostasis of ECM metabolism. METHODS Four-week-old and 160-week-old male Japanese white rabbits were used. Age-related changes in IVDs were evaluated histologically using previously established grading system. Immunohistochemistry of TIMP-3 and semiquantitative reverse transcriptase-polymerase reaction (RT-PCR) of TIMP-3, a disintegrin and metalloproteinases with thrombospondin motifs (ADAMTS) 4, 5, and transforming growth factor-beta1 (TGF-beta1), were conducted. RESULTS Semiquantitative assessment of histologic changes indicated that 4-week-old rabbit was equivalent to fetus to 2-year-old human and 160-week-old rabbit was equivalent to 11- to 30-year-old human, particularly 11- to 16-year-old, which corresponds to transition period from notochordal to fibrocartilaginous NP. Immunohistochemistry revealed that TIMP-3 was positive in 4-week-old rabbit only. Semiquantitative RT-PCR revealed that levels of expressions of TGF-beta1 and TIMP-3 mRNAs in 4-week-old were significantly higher than those in 160-week-old rabbits. There was no significant difference in expression of ADAMTS4 mRNA. ADAMTS5 mRNA was not detected or extremely low in both groups. Expression of TIMP-3 mRNA in NP was upregulated by TGF-beta1 but was not affected by IL-1beta. On the contrary, expression of ADAMTS4 mRNA was not upregulated by TGF-beta1 but was upregulated by IL-1beta. CONCLUSIONS Levels of expression of TIMP-3 in notochordal NP were significantly lower in 160-week-old rabbits than those in 4-week-old rabbits. Decrease in expression of TIMP-3, possibly mediated in part by TGF-beta1, may cause imbalance of ADAMTS4/TIMP-3 ratio at transition period from notochordal to fibrocartilaginous NP.

Vascular and cellular invasion into the cartilage is a critical step in the fracture healing. Matrix metalloproteinase-13 (MMP-13) is a member of the zinc-dependent endopeptidase family and plays an important role in remodeling of extracellular matrix. Therefore we investigated the possible involvement of MMP-13 in a murine model of stabilized bone fracture healing. Repair of the fracture in MMP-13 deficient (MMP-13(-/-)) mice was significantly delayed and characterized by a retarded cartilage resorption in the fracture callus. Immunohistochemistry indicated severe defects in vascular penetration and chondroclast recruitment to the fracture callus in MMP-13(-/-) mice. Consistent with the observations, the chondrocyte pellets cultured from the MMP13(-/-) mice exhibited diminished angiogenic activities when the pellets were co-cultured with endothelial cells. These results suggest that MMP-13 is crucial to the process of angiogenesis during healing of fracture, especially in the cartilage resorption process.

Chondrocyte hypertrophy during endochondral ossification is a well-controlled process in which proliferating chondrocytes stop proliferating and differentiate into hypertrophic chondrocytes, which then undergo apoptosis. Chondrocyte hypertrophy induces angiogenesis and mineralization. This step is crucial for the longitudinal growth and development of long bones, but what triggers the process is unknown. Reactive oxygen species (ROS) have been implicated in cellular damage; however, the physiological role of ROS in chondrogenesis is not well characterized. We demonstrate that increasing ROS levels induce chondrocyte hypertrophy. Elevated ROS levels are detected in hypertrophic chondrocytes. In vivo and in vitro treatment with N-acetyl cysteine, which enhances endogenous antioxidant levels and protects cells from oxidative stress, inhibits chondrocyte hypertrophy. In ataxia telangiectasia mutated (Atm)–deficient (Atm−/−) mice, ROS levels were elevated in chondrocytes of growth plates, accompanied by a proliferation defect and stimulation of chondrocyte hypertrophy. Decreased proliferation and excessive hypertrophy in Atm−/− mice were also rescued by antioxidant treatment. These findings indicate that ROS levels regulate inhibition of proliferation and modulate initiation of the hypertrophic changes in chondrocytes.

Purpose To detect the earlier changes of the skeletal muscle of rats after peripheral nerve injury by measuring the apparent diffusion coefficient (ADC) on diffusion MR spectroscopy. Materials and Methods The posterior tibial nerve was transected in six rats (nerve transection group) and was only dissected in six rats (control group). At one, three, five, seven, 14, and 28 days after the surgery, both the T2 value and the ADC of gastrocnemius muscle were measured using a line-scan diffusion spectrum on a 1.5T clinical MR imager on both groups. Results In the nerve transection group, the T2 ratio compared to the contralateral side increased gradually over four weeks after the transection, while the ADC ratio increased right after the surgery and began to decrease at five days. Four weeks after the transection, the ADC ratio returned to normal while the T2 ratio stayed at a high value. The control group indicated an almost constant T2 and ADC ratio during the experimental periods. Conclusion The ADC of the skeletal muscle increased quickly after the transection of the dominant peripheral nerve and was detectable one day after the surgery. Diffusion MRI can be a useful tool for early detection of peripheral nerve injury instead of T2-weighted MRI or electromyography (EMG). J. Magn. Reson. Imaging 2007. © 2007 Wiley-Liss, Inc.

STUDY DESIGN Retrospective study. OBJECTIVE To examine the reliabilities of sagittal spino-pelvic alignment measurements using whole spine-pelvic and local pelvic radiographs and to determine whether spinal deformity affects these reliabilities. SUMMARY OF BACKGROUND DATA Sagittal spino-pelvic alignment is important in adult spinal deformity patients (ASD). Spino-pelvic parameters are closely related to health-related quality of life and indispensable for surgical planning. However, few studies have focused on the reliability of these measurements. METHODS Three spino-pelvic parameters, pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) were measured in 2 patient groups: 33 adult scoliosis (AS) and 33 nondeformity (ND) patients, using whole spine-pelvic lateral radiographs (whole spine radiographs) and local pelvic lateral radiographs (local pelvic radiographs), by 5 experienced spine surgeons. Intra- and interobserver reliabilities for each procedure were evaluated by intraclass correlation coefficients (ICC). The interobserver reliability differences between the 2 procedures were statistically evaluated. The difference between the largest and smallest measurements among the 5 observers was also evaluated in the AS and ND groups. RESULTS Measurement of the 3 parameters using whole spine or local pelvic radiographs showed good to excellent intraobserver reliability (range of ICC: 0.820-0.935). The interobserver reliabilities of PI and PT from local pelvic radiographs were significantly higher than those from whole spine radiographs (P

Spinal extradural arachnoid cyst (SEDAC) is a cyst in the spinal canal that protrudes into the epidural space from a defect in the dura mater and leads to neurological disturbances. We previously showed that familial SEDAC is caused by FOXC2 mutation; however, the causal gene of sporadic SEDAC has not been identified. To identify the causal gene of sporadic SEDAC, we performed whole exome sequencing for 12 subjects with sporadic SEDAC and identified heterozygous HOXD4 loss-of-function mutations in three subjects. HOXD4 haplo-insufficiency causes SEDAC and a transcriptional network containing HOXD4 and FOXC2 is involved in the development of the dura mater and the etiology of SEDAC.

Various silver-coated implants have been developed to prevent implant-associated infections and have shown dramatic effects in vitro. However, the in vivo results have been inconsistent. Recent in vitro studies showed that silver exerts antibacterial activity by mediating the generation of reactive oxygen species in the presence of oxygen. To maintain its antibacterial activity in vivo, the silver should remain in an ionic state and be stably bound to the implant surface. Here, we developed a novel bacteria-resistant hydroxyapatite film in which ionic silver is immobilized via inositol hexaphosphate chelation using a low-heat immersion process. This bacteria-resistant coating demonstrated significant antibacterial activity both in vitro and in vivo. In a murine bioluminescent osteomyelitis model, no bacteria were detectable 21 days after inoculation with S. aureus and placement of this implant. Serum interleukin-6 was elevated in the acute phase in this model, but it was significantly lower in the ionic-silver group than the control group on day 2. Serum C-reactive protein remained significantly higher in the control group than the ionic-silver group on day 14. Because this coating is produced by a low-heat immersion process, it can be applied to complex structures of various materials, to provide significant protection against implant-associated infections.

The aim of the present study was to measure gait velocity in cataract and simulated patients. The study was performed on 239 cataract patients, 115 age-matched subjects and 11 simulated patients. We measured gait velocity and analyzed gait using a three-dimensional motion analysis system. Mean gait velocity before and 2 and 7 months after cataract surgery was 0.91 ± 0.19, 1.04 ± 0.21 and 1.06 ± 0.21 m/s, respectively, for males and 0.84 ± 0.22, 0.91 ± 0.24 and 0.92 ± 0.25 m/s, respectively, for females. The increase after surgery was significant in both groups at 7 months (P P

Spinal extradural arachnoid cyst (SEDAC) is a cyst in the spinal canal, which causes spinal cord compression and subsequent neurological damage. We previously identified two FOXC2 mutations in two SEDAC families. The FOXC2 mutations have been shown to be responsible for lymphedema-distichiasis syndrome (LDS), which includes SEDAC as an occasionally associated phenotype. We encountered a non-familial patient with SEDAC associated with LDS, and identified a novel nonsense mutation in FOXC2, c.349C>T (p.Q117*).

Background Although various risk factors have been reported for adjacent segment degeneration after lumbar fusion, the exact mechanisms and risk factors related to adjacent segment degeneration have not been clear. The present study was conducted to evaluate the risk factors for radiological adjacent segment degeneration in patients surgically treated for single-level L4 spondylolisthesis focusing on a single pathology, a specific fusion level, at a set interval. Methods We assessed preoperative and five-year postoperative radiographs for 72 patients who underwent L4-5 anterior or posterior lumbar interbody fusion for single-level L4 degenerative spondylolisthesis. Adjacent segment degeneration was defined as imaging evidence of one or more of the following conditions at L1-2, L2-3, or L3-4: 1) a loss of more than 20% of the preoperative disc height, 2) anterolisthesis or retrolisthesis greater than 3 mm, 3) or osteophyte formation greater than 3 mm. Results We found adjacent segment degeneration in 21 patients, with 31 discs affected. Multiple logistic regression analysis identified the following significant independent risk factors for adjacent segment degeneration: female gender (odds ratio 10.80; 95% confidence interval 1.20–96.89), posterior lumbar interbody fusion (odds ratio 7.70; 95% confidence interval 1.82–32.66), and pre-existing disc degeneration (odds ratio 12.29; 95% confidence interval 1.69–89.27). Conclusions Female gender, posterior lumbar interbody fusion, and pre-existing disc degeneration were significant independent risk factors for radiologically diagnosed adjacent segment degeneration in patients treated for L4 degenerative spondylolisthesis by interbody lumbar fusion.

OBJECT The object of this study was to investigate correlations between sagittal spinopelvic alignment and improvements in clinical and quality-of-life (QOL) outcomes after lumbar decompression surgery for lumbar spinal canal stenosis (LCS) without coronal imbalance. METHODS The authors retrospectively reviewed data from consecutive patients treated for LCS with decompression surgery in the period from 2009 through 2011. They examined correlations between preoperative or postoperative sagittal vertical axis (SVA) and radiological parameters, clinical outcomes, and health-related (HR)QOL scores in patients divided according to SVA. Clinical outcomes were assessed according to Japanese Orthopaedic Association (JOA) and visual analog scale (VAS) scores. Health-related QOL was evaluated using the Roland-Morris Disability Questionnaire (RMDQ) and the JOA Back Pain Evaluation Questionnaire (JOABPEQ). RESULTS One hundred nine patients were eligible for inclusion in the study. Compared to patients with normal sagittal alignment prior to surgery (Group A: SVA < 50 mm), those with preoperative sagittal imbalance (Group B: SVA ≥ 50 mm) had significantly smaller lumbar lordosis and thoracic kyphosis angles and larger pelvic tilt. In Group B, there was a significant decrease in postoperative SVA compared with the preoperative SVA (76.3 ± 29.7 mm vs 54.3 ± 39.8 mm, p = 0.004). The patients in Group B with severe preoperative sagittal imbalance (SVA > 80 mm) had residual sagittal imbalance after surgery (82.8 ± 41.6 mm). There were no significant differences in clinical and HRQOL outcomes between Groups A and B. Compared to patients with normal postoperative SVA (Group C: SVA < 50 mm), patients with a postoperative SVA ≥ 50 mm (Group D) had significantly lower JOABPEQ scores, both preoperative and postoperative, for walking ability (preop: 36.6 ± 26.3 vs 22.7 ± 26.0, p = 0.038, respectively; postop: 71.1 ± 30.4 vs 42.5 ± 29.6, p < 0.001) and social functioning (preop: 38.7 ± 18.5 vs 30.2 ± 16.7, p = 0.045; postop: 67.0 ± 25.8 vs 49.6 ± 20.0, p = 0.001), as well as significantly higher postoperative RMDQ (4.9 ± 5.2 vs 7.9 ± 5.7, p = 0.015) and VAS scores for low-back pain (2.68 ± 2.69 vs 3.94 ± 2.59, p = 0.039). CONCLUSIONS Preoperative sagittal balance was not significantly correlated with clinical or HRQOL outcomes after decompression surgery in LCS patients without coronal imbalance. Decompression surgery improved the SVA value in patients with preoperative sagittal imbalance; however, the patients with severe preoperative sagittal imbalance (SVA > 80 mm) had residual imbalance after decompression surgery. Both clinical and HRQOL outcomes were negatively affected by postoperative residual sagittal imbalance.

Previous studies have demonstrated that transplantation of neural stem/progenitor cells (NS/PCs) into the lesioned spinal cord can promote functional recovery following incomplete spinal cord injury (SCI) in animal models. However, this strategy is insufficient following complete SCI because of the gap at the lesion epicenter. To obtain functional recovery in a mouse model of complete SCI, this study uses a novel collagen-based microfiber as a scaffold for engrafted NS/PCs. We hypothesized that the NS/PC-microfiber combination would facilitate lesion closure as well as transplant survival in the transected spinal cord. NS/PCs were seeded inside the novel microfibers, where they maintained their capacity to differentiate and proliferate. After transplantation, the stumps of the transected spinal cord were successfully bridged by the NS/PC-laden microfibers. Moreover, the transplanted cells migrated into the host spinal cord and differentiated into three neural lineages (astrocytes, neurons, and oligodendrocytes). However, the NS/PC-laden scaffold could not achieve a neural connection between the rostral end of the injury and the intact caudal area of the spinal cord, nor could it achieve recovery of motor function. To obtain optimal functional recovery, a microfiber design with a modified composition may be useful. Furthermore, combinatorial therapy with rehabilitation and/or medications should also be considered for practical success of biomaterial/cell transplantation-based approaches to regenerative medicine.

Systemic metastasis to a primary tumor of the central nervous system is uncommon. Breast carcinomas metastasizing to a possibly preexisting meningioma in the spine are reported very rarely.Case report.A 69-year-old female was referred to us with progressive gait disturbance. She had undergone a total mastectomy for carcinoma of the right breast 11 years previously. A magnetic resonance imaging of the thoracic spine showed an intra- and extradural spinal cord tumor. The patient underwent resection of the tumor via laminectomy from T2 to T4. After the operation, the patient's neurological status improved significantly, and she was able to walk without assistance. Histological examination showed the tumor to be a fibrous-type meningioma within a metastatic breast cancer tumor. The patient underwent 40 Gy radiation treatment for local control of the tumor. However, the tumor recurred locally 7 months after the surgery. The patient died of carcinomatous pleurisy 13 months after the surgery.This case illustrates that a primary meningioma in the thoracic spine can be a recipient of breast cancer metastasis, which may alter the treatment strategy.

Background Vascular endothelial growth factor (VEGF) is a potent mediator of angiogenesis. Hypothesis An application of VEGF may enhance angiogenesis in the grafted tendon in anterior cruciate ligament (ACL) reconstruction, and the application may affect mechanical characteristics of the ACL graft. Study Design Controlled laboratory study. Methods Eighteen sheep were divided into groups I and II. In group I, the harvested semitendinosus tendon was soaked in VEGF solution, and the right knee then underwent ACL reconstruction using this tendon. In group II, the right knee underwent identical procedures to those of group I except that the harvested tendon was soaked in phosphate-buffered saline. All animals were sacrificed 12 weeks after ACL reconstruction. Results Histologic findings showed that newly formed vessels and infiltrative fibroblasts were more abundant in group I than in group II. The anterior-posterior translation of the knee during an anterior-posterior force of ±100 N was significantly larger in group I than in group II by 2.58 mm (95% confidence interval, -1.76 mm to 1.76 mm) (P =. 002). The linear stiffness of the femur-graft-tibia complex in group I was significantly lower than that in group II by 41.5 N/mm (95% confidence interval, -32.2 N/mm to 32.2 N/mm) (P=. 017). Conclusion This study has revealed that VEGF as administered in this study promotes angiogenesis in the ACL graft and significantly reduces the stiffness of the ACL graft with increased knee laxity at 12 weeks after ACL reconstruction. Clinical Relevance Exogenous VEGF application for ACL reconstruction can induce an increase in knee laxity and a decrease in the stiffness of the grafted tendon at least temporarily after ACL reconstruction. These potentially negative mechanical effects need to be taken into account when considering clinical use of VEGF.

Object Many prognostic factors associated with surgery for cervical spondylotic myelopathy (CSM) have been detailed in the literature. All of these factors, however, are defined preoperatively. If it is possible to clarify factors influencing surgical results that can be modulated after surgery, then the overall results of surgery may improve. The purpose of this study was to elucidate such postoperative factors affecting neurological recovery. Methods The authors assessed the surgical outcomes obtained in 183 patients with CSM who underwent expansive open-door laminoplasty between 1993 and 2004 and who underwent follow up for a minimum of 1 year. They classified the cases into two groups according to the degree of neurological recovery: an excellent recovery group, comprising patients in whom the recovery rates were greater than 75%, and a poor recovery group, composed of patients in whom the recovery rates were lower than 30%. Comparisons of various clinical and imaging parameters revealed that the mean age at surgery was significantly lower in patients in the excellent recovery group than that in the poor recovery group. Therefore, the authors repeated the same analyses after adjustment for age. Postoperative cervical range of motion (ROM) was significantly more reduced in the excellent recovery group than in the poor recovery group. There was a significant positive correlation between reduced cervical ROM and recovery rate in the poor recovery group. Conclusions Dynamic stress may ameliorate functional recovery of the degenerated spinal cord even after sufficient decompression. Postoperative preservation of cervical ROM may not always be beneficial for neurological recovery in patients with CSM.

Axons in the adult mammalian central nervous system (CNS) exhibit little regeneration after injury. It has been suggested that several axonal growth inhibitors prevent CNS axonal regeneration. Recent research has demonstrated that semaphorin3A (Sema3A) is one of the major inhibitors of axonal regeneration. We identified a strong and selective inhibitor of Sema3A, SM-216289, from the fermentation broth of a fungal strain. To examine the effect of SM-216289 in vivo, we transected the spinal cord of adult rats and administered SM-216289 into the lesion site for 4 weeks. Rats treated with SM-216289 showed substantially enhanced regeneration and/or preservation of injured axons, robust Schwann cell-mediated myelination and axonal regeneration in the lesion site, appreciable decreases in apoptotic cell number and marked enhancement of angiogenesis, resulting in considerably better functional recovery. Thus, Sema3A is essential for the inhibition of axonal regeneration and other regenerative responses after spinal cord injury (SCI). These results support the possibility of using Sema3A inhibitors in the treatment of human SCI.

Many kinds of materials are currently used as artificial bone substitutes. Hydroxyapatite (HA), the same as the main inorganic component of bone, is one of commonly used bio-ceramics and has excellent bioactivity and biocompatibility with hard tissues. However, it has problems as the bone filler or bone tissue-engineering scaffold due to low fracture toughness and low degradation rate. Recently, biodegradable materials for bone tissue have been developed to respond the requirement. Collagen, the same as the main organic component of bone, is biocompatible, biodegradable and promotes cell adhesion. A composites associated with HA is expected to have early osteoconduction and bone replacement ability. The present study was to fabricate bone-like composites consist of HA and collagen. Besides the ossiferous ability of the material in vivo is evaluated by using rabbits. Bone-like composites were successfully fabricated in this study, associating the collagen with HA. And the composites presented good osteoconductive and bone replacement potential.

Lumbar disc disease (LDD) is a common musculo-skeletal disease with strong genetic determinants. In a Finnish population, a single nucleotide polymorphism (SNP) causing an amino-acid substitution (Trp2 allele) in COL9A2, which encodes the alpha2 (IX) chain of type IX collagen, has been reported to associate with LDD. However, replication studies in different populations have produced controversial results. To further investigate the association of COL9A2 with LDD in Japanese, we examined SNPs in COL9A2, including Trp2, in 470 LDD patients (mean age 35) along with 658 controls (mean age 48). We identified a total of 43 sequence variations in COL9A2. Nine SNPs, including Trp2, were selected and genotyped. After Bonferroni's correction, none of these SNPs showed association. Unlike observations in the Finnish population, Trp2 was common in Japanese, and no association with LDD was apparent. However, we did see association of a COL9A2 specific haplotype with LDD (P=0.025; permutation test); this association is more significant in patients with severe lumbar disc degeneration (P=0.011). Thus, the association of Trp2 with LDD was not replicated, but COL9A2 susceptibility allele(s) other than Trp2 may be present in Japanese LDD.

Peripheral nerve injury changes the kinetics of neurotrophins. The production of several neurotrophins increases at the site of injury. Although numerous reports have described changes in neurotrophins over time in areas of nerve injury, neurotrophin mRNA is present at very low levels in target tissues, making accurate quantitation difficult. We developed a reverse transcription–polymerase chain reaction/high-performance liquid chromatography (RT-PCR/HPLC) method that enables accurate quantitation of neurotrophin mRNA. We then attempted to quantitate mRNA levels for nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) produced by skeletal muscle innervated by the sciatic nerve following transection and reattachment of the nerve in mice. In addition, wet weights of the muscle were measured and changes in weight over time were determined. The results indicated that neurotrophin production in muscle increases as a result of peripheral nerve denervation due to transection, and decreases with nerve regeneration and reinnervation resulting from reattachment.

Osteoclasts are the only cells that can resorb bone matrix physiologically and maintain the bone content. Osteoclasts are derived from macrophage/monocyte lin- eage cells; stimulation by macrophage colony stimulating factor and receptor activator of NFκB ligand induces osteoclastogenesis. During osteoclastogenesis, preo- steoclasts fuse to form multinuclear mature osteoclasts. Cellular fusion is a unique phenomenon and enables fertili- zation, myotube formation, and efficient bone resorption in vertebrates. To date, several molecules have been reported to be fusion related in osteoclasts, namely CD44, CD47, ADAM12, MCP-1, and CD9, although the molecules which regulate osteoclast cellular fusion remain unclear. Here, we show that the seven-transmembrane-region receptor den- dritic cell-specific transmembrane protein (DC-STAMP) is required for cell-cell fusion of osteoclasts and foreign body giant cells.

A case of successful treatment of pronation contracture of the forearm due to iatrogenic scar formation in the distal membranous part of the interosseous membrane of the forearm is presented and the management of this problem is discussed.

✓ The authors present clinical, radiological, and pathological features in a patient with a pleomorphic xanthoastrocytoma (PXA) of the spinal cord. To their knowledge, this is only the second report of a spinal cord PXA. In addition they perform a review of the literature on these tumors.

In the injured central nervous system (CNS), reactive astrocytes form a glial scar and are considered to be detrimental for axonal regeneration, but their function remains elusive. Here we show that reactive astrocytes have a crucial role in wound healing and functional recovery by using mice with a selective deletion of the protein signal transducer and activator of transcription 3 (Stat3) or the protein suppressor of cytokine signaling 3 (Socs3) under the control of the Nes promoterenhancer (Nes-Stat3 –/– , Nes-Socs3 –/– ). Reactive astrocytes in Nes-Stat3 –/– mice showed limited migration and resulted in markedly widespread infiltration of inflammatory cells, neural disruption and demyelination with severe motor deficits after contusive spinal cord injury (SCI). On the contrary, we observed rapid migration of reactive astrocytes to seclude inflammatory cells, enhanced contraction of lesion area and notable improvement in functional recovery in Nes-Socs3 –/– mice. These results suggest that Stat3 is a key regulator of reactive astrocytes in the healing process after SCI, providing a potential target for intervention in the treatment of CNS injury. Because the regenerative capability of the mammalian CNS is poor, limited functional recovery occurs during the chronic phase of SCI. At the subacute phase of SCI, however, gradual functional recovery is observed to some extent in both rodents and humans (except in cases of complete paralysis). The mechanism behind this functional recovery remains unclear. Here, we investigated this issue by focusing on the action of reactive astrocytes in a mouse model of SCI. To interpret the process of paralysis improvement in the subacute phase, we examined serial histological sections of contused spinal cords and followed motor function for 6 weeks after injury in wild-type mice and found that the area of neural cell loss gradually enlarged in a rostral-caudal direction within a few days after SCI (acute phase) and a portion of Hu-expressing neurons were positive for cleaved caspase-3, indicating that the secondary injury process lasted for several days in this model (Supplementary Fig. 1 online) during which we observed limited functional recovery (Fig. 1a). Astrocytes surrounding the lesion underwent a typical change of hypertrophy, process extension and increased expression of intermediate filaments such as GFAP and Nestin by 7 d after SCI (Fig. 1b), characteristic of ‘reactive astrocytes.’ Notably, these astrocytes eventually migrated centripetally to the lesion

Study Design. An experimental study, in which spinal fusion in rats was conducted using a hydroxyapatite fiber mesh (HAM) as a carrier for recombinant human bone morphogenetic protein (rhBMP)-2. Objectives. To study the usefulness of the HAM as a carrier and seek the possibility of clinical application in spinal fusion. Summary of Background Data. Several biomaterials have been used as a carrier for BMP to achieve spine fusion, however, to our knowledge, the most effective carrier has not been established. Methods. In experiment No. 1, HAMs and the controls (commercially available hydroxyapatite ceramic body), loaded with rhBMP-2, were immersed in phosphate-buffered saline to evaluate the time course of the release of rhBMP-2. In experiment No. 2, posterolateral fusion was conducted in rats using HAM and the control loaded with rhBMP-2. The fusion status was evaluated radiologically and histologically after surgery. Results. In experiment No. 1, HAMs released a larger amount of rhBMP-2 for up to 28 days than the controls (49.5% vs 7.8%). In experiment No. 2, the fusion rate was significantly higher in the HAM group (>80%) than in the control group (20%). Dense new bone formed close to the spine, and the HAMs were markedly absorbed compared with the controls. Conclusion. HAM provided more solid fusion mass than the control, suggesting that HAM is an efficient carrier for BMP.

Notch signaling is an evolutionarily conserved mechanism that plays a critical role in the determination of multiple cellular differentiation pathways and morphogenesis during embryogenesis. The limb bud high-density culture is an established model that recapitulates mesenchymal condensation and chondrocyte differentiation. Reverse transcription-polymerase chain reaction (RT-PCR) showed that Notch and its related genes were expressed in such cultures on day 1 and reached a peak between day 3 and day 5, when cell condensation and nodule formation were initiated. Immunohistochemical experiments revealed that the expression of Notch1 was initially localized within the nodules and shifted to their peripheral region as the cell differentiation progressed. We disrupted Notch signaling by using a gamma-secretase inhibitor, N-[N-(3,5-difluorophenacetyl-L-alanyl)]-S-phenylglycine t-butyl ester (DAPT), to analyze the function of Notch signaling in the culture system. The blocking of Notch signaling by DAPT apparently promoted the initiation of prechondrogenic condensation and fusion of the nodules, and such an effect was reversed by exogenous expression of the Notch cytoplasmic domain. DAPT treatment also induced chondrogenic markers and bone morphogenetic protein (BMP)-related molecules, including type II collagen, Sox9, GDF5, and Id1. These observations imply that the Notch signal may have an important role in chondrogenic differentiation by negatively regulating the initiation of prechondrogenic condensation and nodule formation.

✓ The authors report the cases of three patients with L-5 radiculopathy caused by extraforaminal entrapment of the L-5 spinal nerve at the lumbosacral tunnel; this structure comprises the lumbosacral ligament, the sacral ala, and the L-5 and S-1 vertebral bodies. All three patients suffered severe leg pain and neurological deficits compatible with L-5 radiculopathy. Decompressive surgery involved the microendoscopic partial resection of the sacral ala along the L-5 spinal nerve. All patients experienced immediate pain relief postoperatively. Microendoscopic partial resection of the sacral ala is an effective and minimally invasive surgical option for patients with extraforaminal entrapment of the L-5 spinal nerve.

Joint effusion after total joint arthroplasty (TJA) is a manifestation of inflammatory reactions within the prosthetic joint. Among the various causes for joint effusion following TJA, deep infection (DI), wear particle-induced synovitis (PS) and metal sensitivity to the implant should be excluded as soon as possible, as these may result in the failure of TJA. The present study analyzed joint fluid cells from patients after total knee arthroplasty (TKA) using fluorescence-activated cell sorter (FACS), and examined the feasibility of using FACS to exclude the possibility of biomaterial-related complication. A total of 72TKAs from 64 patients suffering from joint effusion were examined in this study. Joint fluid was aspirated in outpatient clinics and applied to FACS. The results indicated that patients could be clearly classified into four types based on forward/side scatter profiles. Analysis of specific CD markers revealed that leukocytes were selectively recruited from blood to inflamed prosthetic joints. Dominant cell types were CD16+neutrophils in DI and increased rheumatoid activity, CD14+macrophages in PS, and CD3+CD45RO+T cells in metal sensitivity. These findings suggest the feasibility of diagnosing joint effusion by analyzing dominant cell type recruited using FACS. In conclusion, FACS may offer a useful tool for analyzing joint fluid cells from post-TJA patients and for excluding biomaterial-related complication following TJA.

Objective. Polymorphisms and haplotypes of the peptidylarginine deiminase type 4 gene (PADI4) have been reported to be associated with rheumatoid arthritis (RA) in a Japanese population. However, subsequent replication studies showed conflicting results. The aim of this study was to determine whether meta-analysis would prove the existence of the association. Methods. PubMed was searched using the term ‘PADI4’ for articles from the publication of the first study to December 2005. Replication studies that tested the association between PADI4 and RA were reviewed for meta-analysis. The Breslow–Day test for homogeneity across the studies was calculated. The Mantel–Haenszel procedure was used to pool odds ratios (OR) with 95% confidence intervals (CI) to evaluate the association. Results. Six replication studies, one from Japan and five from Europe and North America, fulfilled the selection criteria for inclusion in the meta-analysis. Homogeneity was confirmed across the replication studies. The common OR was 1.14 (95% CI ¼ 1.07–1.21) for allelic distribution. The association was confirmed when only five replication studies in the European descent populations were combined (P ¼ 0.0096, common OR ¼ 1.10). Conclusions. Our meta-analysis showed a positive association between PADI4 and RA not only in the Japanese population but also in populations of European descent.

Transplantation of neural stem cells (NSC) into lesioned spinal cord offers the potential to increase regeneration by replacing lost neurons or oligodendrocytes. The majority of transplanted NSC, however, typically differentiate into astrocytes that may exacerbate glial scar formation. Here we show that blocking of ciliary neurotrophic factor (CNTF) with anti-CNTF antibodies after NSC transplant into spinal cord injury (SCI) resulted in a reduction of glial scar formation by 8 weeks. Treated animals had a wider distribution of transplanted NSC compared with the control animals. The NSC around the lesion coexpressed either nestin or markers for neurons, oligodendrocytes, or astrocytes. Approximately 20% fewer glial fibrillary acidic protein-positive/bromodeoxyuridine (BrdU)-positive cells were seen at 2, 4, and 8 weeks postgrafting, compared with the control animals. Furthermore, more CNPase(+)/BrdU(+) cells were detected in the treated group at 4 and 8 weeks. These CNPase(+) or Rip(+) mature oligodendrocytes were seen in close proximity to host corticospinal tract (CST) and 5HT(+) serotonergic axon. We also demonstrate that the number of regenerated CST fibers both at the lesion and at caudal sites in treated animals was significantly greater than that in the control animals at 8 weeks. We suggest that the blocking of CNTF at the beginning of SCI provides a more favorable environment for the differentiation of transplanted NSC and the regeneration of host axons.

Although it was long thought that the damaged adult central nervous system (CNS) cannot regenerate, spinal cord injury (SCI) is now an important target in regenerative medicine. A series of studies on stem cell-based therapies for SCI has led us to believe that neural stem/progenitor cells (NSPCs) are a promising source for neural tissue replacement therapy after SCI, when applied appropriately. In this review, we summarize our previous findings on stem cell therapies for SCI and discuss the future directions of this work.

Intervertebral disc (IVD) consists of a soft gelatinous material in its center, the nucleus pulposus (NP), bounded peripherally by fibrocartilage, annulus fibrosus (AF). Despite the number of patients with IVD degeneration, gene expression analysis has not been undertaken in NP and therefore little is known about the molecular markers expressed in NP. Here, we undertook a microarray screen in NP with the other nine tissues to identify the specific cell surface markers for NP. Five membrane associating molecules out of 10,490 genes were identified as highly expressing genes in NP compared with the other tissues. Among them, we identified CD24, a glycosylphosphatidylinositol (GPI) anchor protein as a cell surface marker for NP. CD24 expression was also detected in the herniated NP and chordoma, a malignant primary tumor derived from notochordal cells, while it was absent in chondrosarcoma. Therefore, CD24 is a molecular marker for NP as well as the diseases of IVD.

We previously reported that the transplantation of neural stem/progenitor cells (NSPCs) can contribute to the repair of injured spinal cord in adult rats and monkeys. In some cases, however, most of the transplanted cells adhered to the cavity wall and failed to migrate and integrate into the host spinal cord. In this study we focused on chondroitin sulfate proteoglycan (CSPG), a known constituent of glial scars that is strongly expressed after spinal cord injury (SCI), as a putative inhibitor of NSPC migration in vivo. We hypothesized that the digestion of CSPG by chondroitinase ABC (C-ABC) might promote the migration of transplanted cells and neurite outgrowth after SCI. An in vitro study revealed that the migration of NSPC-derived cells was inhibited by CSPG and that this inhibitory effect was attenuated by C-ABC pre-treatment. Consistently, an in vivo study of C-ABC treatment combined with NSPC transplantation into injured spinal cord revealed that C-ABC pre-treatment promoted the migration of the transplanted cells, whereas CSPG-immunopositive scar tissue around the lesion cavity prevented their migration into the host spinal cord in the absence of C-ABC pre-treatment. Furthermore, this combined treatment significantly induced the outgrowth of a greater number of growth-associated protein-43-positive fibers at the lesion epicentre, compared with NSPC transplantation alone. These findings suggested that the application of C-ABC enhanced the benefits of NSPC transplantation for SCI by reducing the inhibitory effects of the glial scar, indicating that this combined treatment may be a promising strategy for the regeneration of injured spinal cord.

Objectives To study the role of monocyte chemoattractant protein-4 (MCP-4)/CCL13 in the pathogenesis of rheumatoid arthritis (RA), we analysed the expression of MCP-4/CCL13 in chondrocytes, synovial fluid and serum from patients with RA and investigated the effect of MCP-4/CCL13 on the proliferation of synovial cells. Methods Human articular cartilage specimens were obtained from joints from RA and osteoarthritis (OA) patients and normal joints (controls). Transcript levels of MCP-4 in cartilage were determined by real-time polymerase chain reaction. Protein levels were measured by enzyme-linked immunoassay. Cultured fibroblast-like synoviocytes (FLS) were treated with various concentrations of recombinant MCP-4/CCL13 protein, and cell proliferation was evaluated with a viability assay. Results The gene expression of MCP-4 was significantly higher in cartilage from RA patients than in that from OA patients (P = 0.00902) and in normal cartilage (P = 0.00902). The concentration of MCP-4/CCL13 protein in serum from RA patients (mean 94.7 +/- 37.6 pg/ml) was significantly higher than in serum from OA patients (mean 49.2 +/- 31.2 pg/ml, P = 0.0051) and controls (mean 32.6 +/- 23.9 pg/ml, P = 0.0001). The concentration of MCP-4/CCL13 protein in synovial fluid from RA patients (mean 247.2 +/- 161.2 pg/ml) was also significantly higher than in that from OA patients (mean 29.6 +/- 50.5 pg/ml, P = 0.000019). Moreover, MCP-4/CCL13 enhanced the proliferation of FLS in a dose-dependent manner. Conclusions MCP-4/CCL13 is highly expressed in RA joints at the mRNA and protein levels. Our results suggest that MCP-4/CCL13 is secreted from chondrocytes and activates the proliferation of rheumatoid synovial cells, thereby leading to joint destruction in RA.