Takeshi Nomura

Tokai University, Hiratuka, Kanagawa, Japan

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Publications (11)29.92 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Intramedullary spinal cord metastasis (ISCM) is a rare complication of cancer. This complication has been studied by magnetic resonance imaging (MRI) more frequently in the clinical context to improve the survival time of cancer patients. However, the number of the reports of its clinical management or radiographic findings is small. To investigate the clinical and imaging characteristics of ISCM, seven cases of ISCM of a nonneurogenic origin were examined retrospectively. Data regarding the site of the primary neoplasm, location of other metastases, initial symptoms, interval from the original diagnosis of cancer to the onset of neurologic symptoms, time course from initial symptoms to urinary retention, MRI data, and outcome after radiologic or surgical intervention were investigated. Five patients had lung cancer metastases, and one each had breast or uterine cancer metastases. The progression of neurologic deficit was rapid, and the average period between the occurrence of initial symptoms and urinary retention was 25 days. The averaged survival period from the diagnosis of ISCM was 5 months in three patients. (One patient is alive, and the data could not be obtained in another three patients.) MRI characteristics were useful for diagnosis, including large high signal intensity areas on T2-weighted images and strong ring or inhomogeneous enhancement on gadopentetate dimeglumine-enhanced T1-weighted images. Surgery was performed on two patients, but total removal could not be achieved. Radiotherapy was effective in treating neurologic deficit in five patients. Surgical treatment is seldom indicated for ISCM, and radiotherapy is recommended as soon as possible after a diagnosis is made from MRI.
    Journal of Spinal Disorders & Techniques 03/2006; 19(1):43-7. DOI:10.1097/01.bsd.0000188661.08342.2a · 1.89 Impact Factor
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    ABSTRACT: We reviewed the surgical treatment of 31 patients with burst fractures or teardrop dislocation fractures in the middle and lower cervical spine. Patients were treated with anterior instrumentation, posterior instrumentation, or a combination of both. Patients were evaluated radiographically and with the Frankel neurological outcomes grading scale. Anterior decompression and fusion restored the spinal canal diameter by approximately 60% whereas the posterior or combined approaches restored the canal diameter by only 6%. In addition, nine of 24 patients treated anteriorly gained improved neurological function whereas none of the patients treated posteriorly had neurological improvement. Based on the anatomical and neurological findings, the study demonstrates that anterior fusion is preferable to posterior fusion for the treatment of burst fractures and tear-drop dislocation fractures of the middle and lower cervical spine.
    International Orthopaedics 03/2006; 30(1):54-8. DOI:10.1007/s00264-005-0016-4 · 2.02 Impact Factor
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    ABSTRACT: Most patients with traumatic spondylolisthesis of the axis are treated nonsurgically. Some patients do not develop symptoms, but others experience strong and persistent neck pain. To clarify the factor that plays a major role in residual neck pain after this fracture, we reviewed nine patients who underwent conservative treatment. Patients were assessed via telephone interviews an average of 62 months after injury and were divided into two groups: those with and those without neck pain. Angulation and anterior translation between the second and third cervical vertebrae were measured on lateral radiograms at the time of injury, removal of brace, and final follow-up. Fracture lines were also investigated by computed tomography. At the time of final follow-up, the average angulation was 6.3 degrees and the average translation was 5.3 mm in the neck-pain group and 0.6 degrees and 0.2 mm, respectively, in the no-symptom group. In patients with fracture lines present on the articular surface of the inferior face joints, angulation persisted or increased, even though the fractures were hemilateral. This was compatible with severe neck pain. In contrast, angulation and translation were improved in patients with an intact inferior articular surface of the axis, and pain was not reported. Injury on the inferior articular surface of the axis may disturb spontaneous healing of C2-C3 subluxation and cause residual neck pain. It is necessary to assess the presence of injury to the inferior facet bilaterally with plain or computed tomograms.
    Journal of Spinal Disorders & Techniques 05/2005; 18(2):148-51. DOI:10.1097/01.bsd.0000154459.47467.d6 · 1.89 Impact Factor
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    ABSTRACT: Intervertebral disc degeneration is considered to be one of the major causes of low back pain. Despite this irreversible phenomenon, attempts to decelerate disc degeneration using various techniques have been reported. However, to date there has been no proven technique effective for broad clinical application. Based on previous studies, we hypothesize that maintenance of proteoglycan content in the disc is achieved by avoiding the depletion of nucleus pulposus and preserving the structure of the annulus is a primary factor in decelerating disc degeneration. One novel approach to solve the dilemma of intervertebral disc degeneration is found at the stem cell level. Mesenchymal stem cells (MSCs) are known to possess the ability to differentiate into various kinds of cells from mesenchymal origin. Although the majority of cells that contribute to disc formation are known to obtain chondrocyte-like phenotypes, no reported study has emphasized the correlation with mesenchymal stem cells. To evaluate the possible potential of MSCs in disc cell research and treatment of degenerative disc disease, autologous MSCs embedded in Atelocollagen gel were transplanted into the discs of rabbits which had undergone a procedure proven to induce degeneration. The results suggest that MSC transplantation is effective in decelerating disc degeneration in experimental models and provided new hopes for treatment of degenerative disc disease in humans. Atelocollagen gel served as an important carrier of MSCs in transplantation, permitting proliferation, matrix synthesis and differentiation of MSCs. This study strengthens the viable efficacy of practical application of MSCs in treatment of intervertebral disc disease.
    Biomaterials 10/2003; 24(20):3531-41. DOI:10.1016/S0142-9612(03)00222-9 · 8.31 Impact Factor
  • The Spine Journal 09/2003; 3(5):101-101. DOI:10.1016/S1529-9430(03)00254-7 · 2.80 Impact Factor
  • The Spine Journal 09/2003; 3(5):101-102. DOI:10.1016/S1529-9430(03)00255-9 · 2.80 Impact Factor
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    ABSTRACT: We examined the emergence and sequential changes in type I, II, and VI collagen production in an experimental rabbit model of disc degeneration. Type I collagen was minimally present initially and did not change over 24 weeks. Type I collagen seemed to have no effect on the degenerative process in this model. Staining for type II collagen was positive circumferentially in chondrocytelike cells and was mild in the early phase of disc degeneration, when the chondrocytelike cells began to appear in the inner layers of the annulus fibrosus. The stain became stronger during the middle phase when the chondrocytelike cells arranged themselves in cluster. Compared with type II collagen, the staining for type VI collagen was relatively strong early in the degenerative process. These findings led us to speculate that these chondrocytelike cells play an active role in the degenerative process. The reinsertion of nucleus pulposus cells cocultured with annulus fibrosus delayed disc degeneration and the emergence of chondrocytelike cells. Considering that the emergence of chondrocytelike cells which produce type II and type VI collagen is delayed in discs with the injection of cocultured nucleus pulposus cells by annulus fibrosus cells, we conclude that chondrocytelike cells that produce type VI collagen also seems to accelerate degeneration. Type VI collagen is produced at an earlier phase than type II collagen and may be both active agent and a marker for disc degeneration.
    Connective Tissue Research 02/2003; 44(2):104-8. DOI:10.1080/713713657 · 1.98 Impact Factor
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    ABSTRACT: Three case reports of solitary spinal osteochondromas in middle-aged and elderly patients. To describe the treatment of three rare cases of spinal osteochondromas in patients significantly older than the cases previously reported in the literature. Osteochondromas arising in the vertebral column are considered rare. The mean age of clinical appearance is said to be in the second or third decade of life. Clinical history, physical examinations, plain radiographs, magnetic resonance imaging, myelography, computed tomographic myelography, and histopathologic findings for each case were reviewed in conjunction with previous cases reported in the literature. Total removal of the tumor was effective in causing the symptoms to disappear. Spinal osteochondromas are rare and tend to appear in young adults. Three cases of spinal osteochondromas that were unusual in terms of age at clinical presentation and localization were reported, suggesting a continuous growth of the tumor beyond skeletal maturity.
    Spine 01/2003; 27(23):E503-6. DOI:10.1097/01.BRS.0000035310.98737.92 · 2.45 Impact Factor
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    ABSTRACT: Autogenous implantation of nucleus pulposus or nucleus pulposus cells that were activated by coculture retards intervertebral disc degeneration, but harvesting such grafts causes disc degeneration at the donor site. This study examined whether nucleus pulposus allografts similarly retard disc degeneration and whether such allografting induces immunologic rejection. Japanese White rabbits served as donors and recipients for allografts. Lumbar disc degeneration was induced by aspirating the nucleus pulposus. Two weeks later, intact nucleus pulposus or nucleus pulposus cells were injected and compared with a sham procedure and normal control. The recipients' discs were examined histologically and immunologically at intervals for 16 weeks. Discs receiving an intact nucleus pulposus showed the least degeneration, followed by discs receiving nucleus pulposus cells, both of which were better than no treatment. These findings correlated directly with the intensity of immunochemical staining for Type II collagen. Allogeneic grafts did not induce any appreciable host-versus-graft response. Injection of nucleus pulposus and nucleus pulposus cells retards intervertebral disc degeneration. However, injection of intact nucleus pulposus is more effective than injection of nucleus pulposus cells alone. The intercellular matrix plays an important, but poorly understood, role in preserving intervertebral discs.
    Clinical Orthopaedics and Related Research 09/2001; DOI:10.1097/00003086-200108000-00015 · 2.88 Impact Factor
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    ABSTRACT: The authors modified the technique of open-door cervical laminoplasty with a patency maintenance method that relies only on soft tissue reconstruction. Thirty-five patients who underwent this procedure were evaluated at more than 2 years' follow-up. The expanded open-door lamina and excellent alignment on the lateral view of the cervical spine were well maintained after surgery. Atrophy of the posterior cervical muscles was not seen. Clinical outcomes were rated satisfactory. Nuchal pain seen in the series of patients who underwent the original expansive open-door laminoplasty or a suspension laminotomy from 1983 to 1993 was decreased in the patients with the modified expansive open-door laminoplasty.
    Journal of Spinal Disorders 11/1999; 12(5):386-91. DOI:10.1097/00002517-199912050-00006 · 1.21 Impact Factor
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    ABSTRACT: A very rare case of intradural extra-arachnoid schwannoma involving the upper cervical spine is described. The tumour most likely originated from the extra-subarachnoid angle region, with its unusual pattern of expansion within the spinal canal resulting from such characteristics of the upper cervical region as a relatively wide spinal canal, an extensive ventral subarachnoid space, and membranous ventromedian and lateral anchoring structures which influenced the direction of tumour enlargement.
    Spinal Cord 01/1999; 36(12):859-63. DOI:10.1038/sj.sc.3100712 · 1.70 Impact Factor