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Naoto Endo

Publications and source records attributed to Naoto Endo.

At least 37 records · Page 2Linked to original sources
PubMed2005

Establishment and characterization of a novel myxofibrosarcoma cell line.

We established a novel human myxofibrosarcoma cell line NMFH-1 and analyzed it with spectral karyotyping and comparative genomic hybridization (CGH). NMFH-1 cells are composed of two different types of cells, small, spindle-shaped mononuclear cells and bizarre multinucleated giant cells, which were maintained in vitro over 200 passages. Xenografted tumor showed typical features of myxofibrosarcoma, which included bizarre multinucleated giant cells. Cytogenetic analyses revealed complex abnormalities, including a t(17;22)(q2?2;q13), which has been found in dermatofibrosarcoma protuberans. Subsequent reverse-transcription polymerase chain reaction revealed that the cell line did not have the COL1A1-PDGFB gene fusion. Significant gains of the 1q12 approximately q23 and 8q13 approximately qter regions and loss of the 9p21 approximately pter and 13q12 regions often found in MFH were observed by CGH analysis. We investigated the origin of multinucleated giant cells in xenografted tumor through DNA in situ hybridization. In this system, the human-specific Alu sequence and the mouse L1 sequence were used as specific cell markers of identity. In situ hybridization revealed neoplastic proliferation of the multinucleated giant cells of human origin.

Aged↗
PubMed2005

Anterior spinal decompression and fusion for cervical flexion myelopathy in young patients.

OBJECT: The mechanism underlying cervical flexion myelopathy (CFM) is unclear. The authors report the results of anterior decompression and fusion (ADF) in terms of neurological status and radiographically documented status in young patients and discuss the pathophysiological mechanism of the entity. METHODS: Twelve patients underwent ADF in which autogenous iliac bone graft was placed. The fusion area was one segment in four cases, two segments in seven, and three segments in one. Neurological status, as determined by the Japanese Orthopaedic Association (JOA) score, radiographic findings, and intraoperative findings were evaluated. The mean follow-up period was 63.3 months (range 20-180 months). Grip strength was significantly improved and sensory disturbances resolved completely. Intrinsic muscle atrophy, however, persisted in all patients at the final follow-up examination. Local kyphosis in the flexed-neck position at the fusion levels was corrected by surgery. Preoperative computerized tomography myelography revealed that the cord compression index, which was calculated by anteroposterior and transverse diameters of the spinal cord, decreased to 33 +/- 6.2% in the flexed-neck position from 39.7 +/- 9.9% in the extended-neck position. The anterior dura mater-spinal cord distance decreased to 1.9 +/- 0.7 mm in the flexed-neck position from 4 +/- 1.2 mm in extended-neck position. The posterior dura mater-spinal cord distance increased to 2.5 +/- 1.1 mm in the flexed-neck position from 1.3 +/- 0.5 mm in the extended-neck position. CONCLUSIONS: Postoperative neurological status was improved in terms of grip strength, sensory disturbance, and JOA score, and local kyphosis in the flexed-neck position at the fusion levels was reduced and stabilized by ADF. In most cases local kyphosis in the flexed-neck position was demonstrated at the corresponding disc level, as were cervical cord compression and decrease of the anterior wall of the dura mater-spinal cord distance in the flexed-neck position. Therefore, the contact pressure between the spinal cord and anterior structures (intact vertebral bodies and intervertebral discs) in the mobile and kyphotic segments was considered to contribute to the onset of CFM. The ADF-related improvement of the clinical symptoms, preventing kyphotic alignment in flexion and decreasing movement of the cervical spine, supports the idea of a contact pressure mechanism. Furthermore, short ADF performed only at the corresponding segments can preserve more mobile segments compared with posterior fusion. Thus, ADF should be the first choice in the treatment of CFM.

Adolescent↗
PubMed2004

Cerebrospinal fluid sampling by lumbar puncture in rats - repeated measurements of nitric oxide metabolites.

The ability to measure nitric oxide (NO) metabolites (NO2- plus NO3-: NOx) in cerebrospinal fluid (CSF) will facilitate understanding the involvement of NO in neurogenic or inflammatory diseases. The purposes of this study were to develop a reliable method for CSF sampling from the lumbar region, and to repeatedly measure NOx in naive rats. NOx in CSF were measured using the Griess method. Twelve young (13-week-old) and seven middle-aged (40-week-old) male Wistar rats were used. CSF (50-70 microl) was collected four times at 1-week intervals. The success rate of CSF collection was 96% and average surgery time was 21 min. The blood contamination rate was 11% on macroscopic inspection. NOx in the CSF ranged from 3.8 to 10.6 microM. The NOx in clear CSF were not significantly different from those with blood contamination on macroscopic inspection. There was, however, a linear correlation between the increase in NOx and the volume of venous blood added experimentally. NOx levels were significantly higher (P < 0.05) in young rats (6.5+/-0.2 microM) than in middle-aged rats (5.6+/-0.3 microM). There was no significant difference in CSF NOx among the four samples collected at 1-week intervals in 13-week-old rats. These results indicate that our CSF sampling technique can be used to reliably obtain a small amount of CSF for NOx measurement. This technique will facilitate further experimental studies of the involvement of CSF NO in neurogenic or inflammatory diseases.

Age Factors↗
PubMed2004

Sclerosing epithelioid fibrosarcoma with der(10)t(10;17)(p11;q11).

Sclerosing epithelioid fibrosarcoma is a recently described, rare mesenchymal neoplasm. We report a case of sclerosing epithelioid fibrosarcoma that occurred in the lower leg of a 48-year-old man. The karyotype of the tumor exhibited der(1)t(1;10)(p31;p11), der(10)t(10;17)(p11;q11), and der(17) t(11;17)(?;q11). Rearrangement of 10p11 was also found in one previous reported case of this uncommon tumor.

Chromosome Aberrations↗
PubMed2004

High-level expression of the coxsackievirus and adenovirus receptor messenger RNA in osteosarcoma, Ewing's sarcoma, and benign neurogenic tumors among musculoskeletal tumors.

PURPOSE: The sensitivity of human tumor tissues to infection with recombinant adenoviruses correlates with the expression of the coxsackievirus and adenovirus receptor (CAR). CAR has been shown to function as the primary receptor for adenoviruses and to play a critical role in adenovirus entry into host cells. It is important for clinical gene therapy to determine the expression level of CAR in tumor tissues. EXPERIMENTAL DESIGN: We analyzed the expression of CAR mRNA in 154 musculoskeletal tumor tissues from 154 patients and 10 normal mesenchymal tissues from 3 patients using reverse transcription-PCR and real-time quantitative PCR. An adenovirus infection assay was performed in two cell lines that were established from CAR-positive osteosarcoma tissue and CAR-negative malignant fibrous histiocytoma tissue. RESULTS: Ninety-nine of 154 tumors were detected as CAR positive by reverse transcription-PCR. We found that the expression levels of CAR mRNA varied markedly between different tumors as determined by real-time quantitative PCR. CAR mRNA was expressed at high levels in osteosarcoma, Ewing's sarcoma, neurofibroma, and schwannoma; at intermediate levels in exostosis, giant cell tumor, liposarcoma, synovial sarcoma, malignant peripheral nerve sheath tumor, and hemangioma; and at low levels in alveolar soft part sarcoma and desmoid. Whereas the osteosarcoma cell line that expressed a high level of CAR mRNA, like its parent tumor, had a high efficiency of adenovirus infection, the malignant fibrous histiocytoma cell line with almost undetectable expression of CAR mRNA, like its parent tumor, had a low efficiency of infection. CONCLUSIONS: Our data showed the great variations in CAR mRNA expression among human musculoskeletal tumors and mesenchymal tissues and implicated the potential usefulness of adenoviral vectors in gene therapy for osteosarcoma, Ewing's sarcoma, neurofibroma, and schwannoma. Efficient transduction with adenovirus for gene therapy could be realized in appropriate, sensitive tumor types.

Adenoviridae↗
PubMed2004

Newly-formed axonal branches of rat sciatic neurons sprouting in the spinal cord after peripheral axotomy.

A retrograde method of nerve tracing using a recombinant adenovirus was applied to experimental regeneration of peripheral nerves to study the sprouting position of the regenerating axon. This enabled us to see the entire length of the axons on a whole-mount neural specimen. The peroneal nerve was transsected and infected with this virus, and the tibial nerve was transsected and sutured in eight Wistar rats. Four to five weeks later, labelled axons appeared in the tibial nerve, some of which could be traced from the tibial nerve to the spinal cord without making a connection with other labelled fibres. Control experiments negated the possibilities of transneuronal immigration or contamination of the virus. When the peroneal and tibial nerves were double-labelled with fluorescent tracers four weeks after their transsection, double-labelled motor neurons appeared. Based on these findings, we conclude that regenerating branches do sprout in the spinal cord after axotomy.

Adenoviridae↗
PubMed2004

Diagnosis of peripheral nerve sheath tumors around the pelvis.

OBJECTIVE: To distinguish between benign and malignant peripheral nerve sheath tumors around the pelvis. METHODS: A retrospective study of 30 patients with benign and malignant peripheral nerve sheath tumors located around the pelvis was performed. Clinical, imaging and histological features of 19 benign and 11 malignant peripheral nerve sheath tumors around the pelvis were reviewed retrospectively. RESULTS: Nearly all patients exhibited pain at presentation in cases involving both benign and malignant tumors. Although tumor size, duration of symptoms and presence of sensory disturbance possessed little value in differential diagnosis, severe motor weakness was observed exclusively in patients presenting with malignant tumors. On CT or MRI, central enhancement was apparent in 11 of the 19 benign tumors; in contrast, central enhancement was evident in one of the 11 malignant tumors. Fine needle aspiration cytology was performed in 11 tumors; correct diagnosis was achieved in four tumors. Core needle biopsy was performed in five tumors, all of which were correctly diagnosed with no neurological deficits. Immunohistochemically, all benign tumors were diffusely positive for S-100 protein, whereas malignant tumors were negative or focally positive for S-100 protein. Ki-67 index was less than 4% in all benign tumors; additionally, this index was 7-36% in malignant tumors. CONCLUSION: Central enhancement pattern on imaging studies strongly suggests a benign tumor; in contrast, severe motor weakness suggests malignant lesions. Core needle biopsy was reliable with respect to preoperative diagnosis.

Adolescent↗
PubMed2004

Properties of the tibial component regarding impact load.

Load transmission through knee prostheses was examined to clarify how the tibial component behaves under dynamic loading conditions. We did Genesis II total knee arthroplasty using sawbones and measured impact load transmission ratios using the split-Hopkinson pressure bar technique. We also measured the polyethylene strain when an impact load was applied using a strain gauge bonded to the anterior surface of the polyethylene. The impact load transmission ratios of metal-backed and all-polyethylene tibial components were less than 4%. Greater load transmission was observed with metal-backed components, which suggests that some of the applied dynamic load is transferred directly to the tibial cortical bone. Increasing polyethylene thickness decreased impact load transmission ratios in both components, which might lower the cancellous bone stresses beneath tibial implants. Greater strain in the tibial component was observed in all-polyethylene components. Increased polyethylene thickness did not significantly decrease the polyethylene strain, probably because of the nonlinear elastic behavior of the polyethylene material. The distant positioning of the strain gauge may, however, have prevented the detection of local contact strains. Recent clinical studies did not confirm our theoretical predictions, suggesting that other factors contribute more significantly to the clinical outcome in current total knee arthroplasty.

Arthroplasty, Replacement, Knee↗
PubMed2004

Homeobox protein MSX2 acts as a molecular defense mechanism for preventing ossification in ligament fibroblasts.

Ligaments and tendons are comprised of tough yet flexible connective tissue. Little is known, however, about the precise characteristics of the cells in ligaments and tendons due to the absence of specific markers and cell lines. We recently reported a periodontal ligament cell line, PDL-L2, with suppressed Runx2/Osf2 transcriptional activity and an inability to form mineralized nodules. The present study demonstrates that the homeobox protein Msx2 is a key factor in suppressing those two functions. Msx2 colocalizes with Runx2/Osf2 and suppresses its activity cooperatively, acting with another corepressor, TLE1, as a complex to recruit histone deacetylase 1 activity. Reverse transcription-PCR and in situ hybridization demonstrated that Msx2 expression is higher in periodontal ligament and tendon cells than in osteoblasts. Stable reduction of Msx2 expression in PDL-L2 cells induces osteoblastic differentiation, thereby causing matrix mineralization. Conversely, stable, forced Msx2 expression in MC3T3-E1 cells prevented osteoblast differentiation and matrix mineralization. Msx2-induced suppression of osteoblast differentiation was repressed by bone morphogenetic protein 2. In addition, Msx2 was downregulated in a symptom- and calcification-dependent manner at the affected region in patients with ossification of the posterior longitudinal ligament. Our findings indicate that Msx2 plays a central role in preventing ligaments and tendons from mineralizing.

Aged↗
PubMed2003

Plexiform schwannoma of the forearm.

We report a case of plexiform schwannoma located in the flexor muscles of the forearm in the absence of other signs of neurofibromatosis or schwannomatosis. Magnetic resonance examination revealed a multinodular irregular inhomogeneous mass. Some nodules displayed a peripheral, high intensity rim and a central low intensity (target sign) on T2-weighted images. Pre-operative diagnosis of the rare plexiform schwannoma may be possible with careful imaging examination for the target sign.

Adult↗
PubMed2003

Presacral multiple cellular schwannomas.

STUDY DESIGN: Case report. The authors documented a patient presenting with multiple cellular schwannomas along the sciatic nerve. The patient had no stigmas of neurofibromatosis. Thirteen tumors were resected via both anterior and posterior approaches. OBJECTIVES: To point out that presacral cellular schwannoma can display multiple occurrences. SUMMARY OF BACKGROUND DATA: Cellular schwannoma, which is a well-recognized variant of benign schwannoma, is often misdiagnosed as sarcoma. The tumor is usually a solitary lesion. MATERIALS AND METHODS: Medical history, physical findings, imaging features, and histologic findings were reviewed in a case of multiple cellular schwannomas in the presacral regions. RESULTS: A 39-year-old woman without any evidence of neurofibromatosis underwent removal of presacral multiple tumors along the sacral nerve root. Nineteen years after the surgery, the tumors recurred with multiple fashion. Thirteen tumors were resected via both anterior and posterior approaches. Immunohistochemical analysis of S-100 protein and Ki-67 were beneficial with respect to differentiation of cellular schwannoma from malignant peripheral nerve sheath tumor. CONCLUSIONS: The present case illustrated that multiple cellular schwannomas can develop in nonneurofibromatosis patients.

Adult↗
PubMed2003

Effect of dexamethasone on growth inhibition and chondrogenic maturation of human chondrosarcoma.

The effect of dexamethasone, a synthetic glucocorticoid, on in vitro and in vivo growth and differentiation of the human chondrosarcoma cell line (OUMS-27) was studied. Cells were treated with various doses of dexamethasone, and increasing doses produced an inhibitory effect on OUMS-27 tumor cell proliferation and induced maturation. Cell counts for OUMS-27 on day 9 ranged from 59% of the control at 10(-8) M to 45% of the control at 10(-5) M dexamethasone. Northern blot analysis revealed that the type II collagen mRNA level in cells given dexamethasone was lower than that in the controls, and the type X collagen mRNA level was higher than that in the controls. Phase-contrast microscopy revealed that cells grown in control medium formed monolayers consisting of small, polygonal cells, whereas dexamethasone-treated cells became larger and more irregular in shape. In the in vivo study the growth rate of masses in nude mice induced by inoculating OUMS-27 cells was also reduced in a dose-dependent manner with dexamethasone administration. These results suggest that dexamethasone caused growth inhibition and induced chondrogenic maturation of human chondrosarcoma cells.

Animals↗
PubMed2003

Activating Gs alpha mutation at the Arg201 codon in liposclerosing myxofibrous tumor.

Liposclerosing myxofibrous tumor (LSMFT) is a benign fibro-osseous lesion that is characterized by mixture of histologic elements including lipoma, fibroxanthoma, myxoma, ischemic ossification, and fibrous dysplasia (FD)-like features. These tissue components are seen in the original reports of FD; however, the relationship between LSMFT and FD is not clear. Point mutation of the alpha subunit of G protein (Gs alpha), which increases cyclic adenosine monophosphate formation, has been recognized as the cause of McCune-Albright syndrome as well as polyostotic and monostotic FD of bone. Gs alpha mutation at the Arg201 codon in 2 patients of LSMFT was demonstrated in the present study. Although direct sequencing analysis using the fresh-frozen materials could not detect the mutation, the polymerase chain reaction fragmentation length polymorphism (PCR-RFLP) disclosed the missense point mutation Gs alpha at the Arg201 codon in 2 cases involving LSMFT. This result strongly suggests that a subset of LSMFT is a variant form of FD.

Aged↗
PubMed2003

Expression of the coxsackievirus and adenovirus receptor in musculoskeletal tumors and mesenchymal tissues: efficacy of adenoviral gene therapy for osteosarcoma.

Recombinant adenovirus is used as a competent vector in a wide spectrum of cancer gene therapies. Adenovirus infection depends on coxsackievirus and adenovirus receptor (CAR)-mediated virus attachment to the cell surface. However, the expression levels of CAR and the efficiency of adenoviral gene transduction in musculoskeletal tumors have not been systematically investigated. To study the feasibility of gene therapy in musculoskeletal tumors, the expression levels of CAR and the antiproliferative effect of an adenovirally transduced wild-type p53 tumor suppressor gene were examined in 15 distinct musculoskeletal tumor cell lines, 19 tumor tissue samples, and the corresponding pathologically unremarkable mesenchymal tissues. The expression levels of the CAR gene were significantly higher in six of seven osteosarcoma cell lines and two of five osteosarcoma tissue samples than in the other cell lines, musculoskeletal tumors, and mesenchymal tissues. CAR expression levels were closely correlated with adenoviral gene transduction efficiency and the antiproliferative effect of a transduced adenoviral p53 gene in the tested cell lines. In addition, an immunocytochemical study confirmed that transfected green fluorescent protein (GFP) borne by Ad-CAG-GFP was expressed at the cell surface of CAR-positive cells. These results indicate that CAR expression is a critical determinant of transduction efficiency in adenovirus-based gene therapy. Most osteosarcomas appeared to express high levels of CAR, and thus adenovirus-mediated p53 gene therapy is likely to be suitable for the treatment of such tumors.

Adenoviruses, Human↗
PubMed2003

Chondromodulin-I expression in rat articular cartilage.

The localization and expression of chondromodulin-I (ChM-I), an angiogenesis inhibitor, in the rat articular cartilage during maturation from 2 to 10 weeks of age were examined by immunohistochemistry, Western blot analysis and ribonuclease protection assay, and the results were compared with those in the epiphyseal cartilage. ChM-I was found to be diffusely immunostained in the inter-territorial space of the cartilage matrix from the intermediate to the deep layers at the immature stage. As the articular cartilage matured, the immunoreactivity was localized around the hypertrophic chondrocytes in the deep layer and the immunoreactivity became weak after maturation. In contrast, the ChM-I immunoreactivity was intense in the epiphyseal cartilage at all ages examined. ChM-I was detected by Western blotting as a broad band or occasionally as a cluster of multiple bands (approximately 25 kDa) in both the articular and the epiphyseal cartilage. The intensity of the bands decreased gradually with age in the articular cartilage, but was unchanged in the epiphyseal cartilage at all ages. Ribonuclease protection assay revealed that ChM-I mRNA also decreased gradually with age in the articular cartilage in parallel with the maturation of the articular cartilage, while no decrease in ChM-I mRNA was found in the epiphyseal cartilage. The expression of ChM-I mRNA in the articular cartilage was less than that in the epiphyseal cartilage at all ages. The decrease in amount of ChM-I in the mature articular cartilage suggests that ChM-I plays a more important role in the maintenance of avascularity in the immature articular cartilage than in the mature one. The avascular condition may be preserved by angiogenic inhibitors or mechanisms other than ChM-I in the mature articular cartilage.

Aging↗
PubMed2003

Expression of the cartilage derived anti-angiogenic factor chondromodulin-I decreases in the early stage of experimental osteoarthritis.

OBJECTIVE: Chondromodulin-I (ChM-I), a cartilage derived anti-angiogenic factor, has been shown to regulate the vascular invasion during endochondral bone formation. We evaluated the expression and localization of ChM-I in articular cartilage during the progression of osteoarthritis (OA) in the rat, and correlated ChM-I expression with the increase in vascular invasion into OA articular cartilage. METHODS: Expression of ChM-I, type II collagen, basic fibroblast growth factor, vascular endothelial growth factor (VEGF), and matrix metalloproteinases MMP-9 and MMP-13 were examined in articular cartilage of intact growing and adult rats and in the surgically induced OA model using in situ hybridization, Western blot analysis, and immunohistochemistry. Co-immunostaining for ChM-I and CD-31 was performed to localize ChM-I and neovascularization in articular cartilage at advanced stage of OA. RESULTS: Abundant expression of ChM-I protein was detected in avascular regions of the developing and adult healthy articular cartilage. In early OA, ChM-I expression decreased in the superficial zone of articular cartilage, while levels of proteoglycan and type II collagen were comparable to control. In advanced OA, ChM-I expression was reduced in all zones of articular cartilage, and the number of VEGF-expressing cells was increased. Immunohistochemical studies showed that vascular invasion occurred in proximity to chondrocytes with high expression of pro-angiogenic markers, and decreased expression of ChM-I. CONCLUSION: High expression of ChM-I was detected in articular cartilage of growing and normal adult joints, implicating its role in the maintenance of avascularity of intact articular cartilage. Expression of ChM-I decreased, while expression of VEGF and other pro-angiogenic factors increased, in OA cartilage. These findings suggest the loss of ChM-I from articular cartilage might be responsible in part for promoting blood vessel invasion into the cartilage during progression of OA.

Angiogenesis Inhibitors↗