Kazutoshi Hida

Feasibility of insertion/implantation of 2.0-mm-diameter gold internal fiducial markers for precise setup and real-time tumor tracking in radiotherapy.

PURPOSE To examine the feasibility and reliability of insertion of internal fiducial markers into various organs for precise setup and real-time tumor tracking in radiotherapy (RT). MATERIALS AND METHODS Equipment and techniques for the insertion of 2.0-mm-diameter gold markers into or near the tumor were developed for spinal/paraspinal lesions, prostate tumors, and liver and lung tumors. Three markers were used to adjust the center of the mass of the target volume to the planned position in spinal/paraspinal lesions and prostate tumors (the three-marker method). The feasibility of the marker insertion and the stability of the position of markers were tested using stopping rules in the clinical protocol (i.e., the procedure was abandoned if 2 of 3 or 3 of 6 patients experienced marker dropping or migration). After the evaluation of the feasibility, the stability of the marker positions was monitored in those patients who entered the dose-escalation study. RESULTS Each of the following was shown to be feasible: bronchoscopic insertion for the peripheral lung; image-guided transcutaneous insertion for the liver; cystoscopic and image-guided percutaneous insertion for the prostate; and surgical implantation for spinal/paraspinal lesions. Transcutaneous insertion of markers for spinal/paraspinal lesions and bronchoscopic insertion for central lung lesions were abandoned. Overall, marker implantation was successful and was used for real-time tumor tracking in RT in 90 (90%) of 100 lesions. No serious complications related to the marker insertion were noted for any of the 100 lesions. Using three markers surgically implanted into the vertebral bone, the mean +/- standard deviation in distance among the three markers was within 0.2 +/- 0.6 mm (range -1.4 to 0.8) through the treatment period of 30 days. The distance between the three markers gradually decreased during RT in five of six prostate cancers, consistent with a mean rate of volume regression of 9.3% (range 0.015-13%) in 10 days. CONCLUSIONS Internal 2.0-mm-diameter gold markers can be safely inserted into various organs for real-time tumor tracking in RT using the prescribed equipment and techniques. The three-marker method has been shown to be a useful technique for precise setup for spinal/paraspinal lesions and prostate tumors.

Migration and differentiation of nuclear fluorescence-labeled bone marrow stromal cells after transplantation into cerebral infarct and spinal cord injury in mice

There is increasing evidence that bone marrow stromal cells (BMSC) have the potential to migrate into the injured neural tissue and to differentiate into the CNS cells, indicating the possibility of autograft transplantation therapy. The present study was aimed to clarify whether the mouse BMSC can migrate into the lesion and differentiate into the CNS cells when transplanted into the mice subjected to focal cerebral infarct or spinal cord injury. The BMSC were harvested from mice and characterized by flow cytometry. Then, the BMSC were labeled by bis‐benzimide, a nuclear fluorescence dye, over 24 h, and were stereotactically transplanted into the brain or spinal cord of the mice. The cultured BMSC expressed low levels of CD45 and high levels of CD90 and Sca‐1 on flow cytometry. A large number of grafted cells survived in the normal brain 4 weeks after transplantation, many of which were located close to the transplanted sites. They expressed the neuronal marker including NeuN, MAP2, and doublecortin on fluorescent immunohistochemistry. However, when the BMSC were transplanted into the ipsilateral striatum of the mice subjected to middle cerebral artery occlusion, many of the grafted cells migrated into the corpus callosum and injured cortex, and also expressed the neuronal markers 4 weeks after transplantation. In particular, NeuN was very useful to validate the differentiation of the grafted cells, because the marker was expressed in the nuclei and was overlapped with bis‐benzimide. Similar results were obtained in the mice subjected to spinal cord injury. However, many of the transplanted BMSC expressed GFAP, an astrocytic protein, in injured spinal cord. The present results indicate that the mouse BMSC can migrate into the CNS lesion and differentiate into the neurons or astrocytes, and that bis‐benzimide is a simple and useful marker to label the donor cells and to evaluate their migration and differentiation in the host neural tissues over a long period.

Surgical Indication and Results of Foramen Magnum Decompression versus Syringosubarachnoid Shunting for Syringomyelia Associated with Chiari I malformation

Several surgical procedures have been used for the treatment of syringomyelia associated with Chiari I malformation at our institute. The purpose of this article is to evaluate the results of two major surgical procedures, foramen magnum decompression (FMD) and syringosubarachnoid (SS) shunting. The series consisted of 70 patients with syringomyelia associated with Chiari I malformation who were surgically treated. Their ages ranged from 3 to 59 years (median, 29.4 yr). FMD was performed on 33 patients, and SS shunting was performed on 37 patients. The follow-up period ranged from 6 months to 12.5 years, with a mean of 60 months. The clinical and radiological outcomes were analyzed comparing the two groups. We principally performed FMD in patients with symptoms of Chiari I malformation and/or a small syrinx. We prefer to use SS shunting in patients with large syringes. Postoperative magnetic resonance imaging demonstrated that the syrinx had collapsed or decreased in size in 94% of the patients who underwent FMD and in 100% of the patients who underwent SS shunting. Neurological improvements were observed in 82% and in 97% of the patients who underwent FMD and SS shunting, respectively. In particular, the relief of pain was more fully achieved after SS shunting than after FMD. The average time for the syrinx to collapse was 6.3 weeks after surgery in the FMD group and 1.8 weeks in the SS shunting group. These results indicate that clinical symptoms and radiological findings improved much more quickly in the SS shunting group than in the FMD group.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone marrow stromal cells protect and repair damaged neurons through multiple mechanisms

A surprising shortage of information surrounds the mechanism by which bone marrow stromal cells (BMSC) restore lost neurologic functions when transplanted into the damaged central nervous system. To clarify the issue, the BMSC were cocultured with the neurons using two paradigms: the cell‐mixing coculture technique and three‐dimensional coculture technique. The green fluorescent protein (GFP)‐expressing BMSC were cocultured with the PKH‐26‐labelled neurons, using cell mixing coculture technique. GFP‐positive, PKH‐26‐negative cells morphologically simulated the neurons and significantly increased the expression of MAP‐2, Tuj‐1, nestin, and GFAP. GFP/nestin‐positive, PKH‐26‐negative cells increased from 13.6% ± 6.7% to 32.1% ± 15.5% over 7 days of coculture. They further enhanced Tuj‐1 expression when cocultured with neurons exposed to 100 μM of glutamate for 10 min. About 20–30% of GFP‐positive cells became positive for PKH‐26 through coculture with the neurons, but the doubly positive cells did not increase when cocultured with glutamate‐exposed neurons. Alternatively, the BMSC significantly ameliorated glutamate‐induced neuronal damage when cocultured with the three‐dimensional coculture technique. The protective effect was more prominent when coculture was started prior to glutamate exposure than when coculture was started just after glutamate exposure. ELISA analysis revealed that the BMSC physiologically produce NGF, BDNF, SDF‐1α, HGF, TGFβ‐1, and IGF‐1 and significantly enhanced the production of NGF and BDNF when cocultured with glutamate‐exposed neurons. These findings strongly suggest that the BMSC may protect and repair the damaged neurons through multiple mechanisms, including transdifferentiation, cell fusion, and production of growth factors.

An interspinous process distractor (X STOP) for lumbar spinal stenosis in elderly patients: preliminary experiences in 10 consecutive cases.

Background Lumbar spinal stenosis (LSS) is often a position-dependent condition that is aggravated in extension and relieved in flexion. Methods Ten consecutive elderly patients with LSS were assessed postoperatively by magnetic resonance imaging and the Swiss Spinal Stenosis Questionnaire. Cross-sectional areas of the dural sac and intervertebral foramina at the stenotic level were measured postoperatively and compared with the preoperative values. Results Postoperatively the cross-sectional area of the dural sac increased 16.6 mm2 or 22.3% and intervertebral foramina increased 22 mm2 or 36.5%. The intervertebral angle and the posterior disc height changed significantly. Seventy percent of the patients were satisfied with the surgical outcome. Conclusion This new surgical method is effective in elderly LSS patients.

Role of SDF-1/CXCR4 system in survival and migration of bone marrow stromal cells after transplantation into mice cerebral infarct

Recent studies have indicated that bone marrow stromal cells (BMSC) have the potential to improve neurological function when transplanted into animal models of cerebral infarction. However, it is still obscure how the transplanted BMSC restore the lost neurological function. In this study, therefore, we aimed to elucidate the role of stromal cell-derived factor-1 (SDF-1) and its specific receptor, CXCR4, in BMSC transplantation into the brain subjected to cerebral infarction. The BMSC were harvested from the wild type (WT) and CXCR4-knockout (CXCR4-KO) mice and were cultured. The mice were subjected to permanent middle cerebral artery occlusion. The WT or CXCR4-KO BMSC was injected into the ipsilateral striatum 7 days after the insult. Motor function of the animals was serially evaluated, using a rotarod treadmill. Using fluorescence immunohistochemistry, we evaluated the distribution and phenotype of the transplanted cells 4 weeks after transplantation. Recovery of motor function in the WT BMSC-transplanted mice was more pronounced than in the CXCR4-KO-transplanted mice and the vehicle-treated ones. SDF-1 was extensively expressed in peri-infarct area. In the WT BMSC-transplanted mice, the transplanted cells were extensively distributed in the ipsilateral hemisphere, and many of them migrated towards the peri-infarct area and expressed the proteins specific for neurons and astrocytes, although these findings were not observed in the CXCR4-KO-transplanted mice. The results suggest that the SDF-1/CXCR4 system may play a critical role in the survival, proliferation and migration of the transplanted BMSC and contribute to recovery of neurological function.

The role of radiotherapy in the management of spinal cord glioma

PURPOSE To determine the role of radiotherapy in the management of spinal cord gliomas. METHODS AND MATERIALS Thirty-six patients with spinal cord glioma treated between 1979 and 1993 were examined. The patients had 13 astrocytic tumors (7 astrocytomas, 4 anaplastic astrocytomas, 2 glioblastomas), 22 ependymal tumors (18 ependymomas, 4 myxopapillary ependymomas), and 1 unclassified glioma. Fifteen of the patients were treated by surgery alone, but the remaining 21 patients also received postoperative radiotherapy. Total resection was performed on 1 astrocytoma and 13 ependymomas. In general, 40-50 Gy/16-20 fractions/4-5 weeks were given after parital resection, but no radiotherapy was given after total resection. RESULTS Actuarial survival was significantly better for patients with ependymal tumors than for those with astrocytic tumors (p = 0007), 5-year actuarial survival rates being 96% and 50% for patients with ependymal tumors and astrocytic tumors, respectively. For patients with ependymal tumors, there was no difference in motor function and survival between those with total resection and those with partial resection followed by radiotherapy. Actuarial 3-year survival was 80% for patients with astrocytomas and 40% for those with anaplastic astrocytomas plus glioblastomas. The difference in the degree of motor function between the patients treated with radiotherapy and those without radiotherapy was not statistically significant. One anaplastic astrocytoma and one glioblastoma patient have lived longer than 4 years after radical treatment including radiocordectomy, or irradiation using doses larger than the tolerance threshold of the spinal cord. CONCLUSION Postoperative conventional radiotherapy is indicated after less than total resection of low-grade ependymal tumors and astrocytomas but not after total resection of ependymomas. Radiocordectomy may be an option for certain cases with high-grade astrocytic tumors.

Surgical treatment supposed natural history of the tethered cord with occult spinal dysraphism

Abstract We retrospectively evaluated the pre- and postoperative course of 34 tethered cord patients with occult spinal dysraphism in an attempt to infer the natural history of this disorder and to determine the effectiveness of the surgical treatment. There were 32 cases with lumbosacral lipoma and 2 with tight filum terminale. The age at surgery ranged from 1 month to 47 years old. Eight patients, aged 1 month to 4 years old, were asymptomatic; 26 had neurogenic bladder (26 cases) or motor problems affecting the legs (8 cases). None of the patients older than 5 years of age were asymptomatic. Untethering of the spinal cord was performed in all cases. The postoperative follow-up period ranged from 5 months to 11 years. During these periods, 7 (88%) of the 8 asymptomatic patients remained neurologically intact, 6 (23%) of the 26 symptomatic patients showed improved symptoms, and 15 patients (58%) remained unchanged. These results indicate that the neurological symptoms will appear progressively in the tethered cord patients, and that prophylactic surgery should be considered as early as possible.

Do bone marrow stromal cells proliferate after transplantation into mice cerebral infarct? : A double labeling study

The present study was aimed to clarify the proliferation capacity of the bone marrow stromal cells (BMSC) transplanted into the brain. The BMSC were harvested from green fluorescence protein (GFP)-transgenic mice, grown to the confluency and passed three times. They were labeled by co-culture with Ferucarbotran, a superparamagnetic iron oxide (SPIO) agent. The proportions of the SPIO-positive cells were evaluated from P3 to P7, using Turnbull blue staining. The GFP-BMSC labeled by Ferucarbotran were transplanted into the ipsilateral striatum of the mice brain subjected to permanent focal ischemia at 7 days after the insult. The distribution and differentiation of GFP- and SPIO-positive cells in the brain were studied 3 months after transplantation, using immunohistochemistry and Turnbull blue staining. As the results, the proportions of the SPIO-positive cells gradually decreased from 93.6% at P3 to 6.5% at P7. Fluorescence immunohistochemistry revealed that the GFP-positive cells were widely distributed around infarct and partially expressed MAP2 and NeuN 3 months after transplantation. However, only a smaller number of SPIO-positive cells could be detected on Turnbull blue staining. The ratio of the SPIO- to GFP-positive cells was approximately 2.7%. The results strongly suggest that the BMSC repeat proliferation many times, migrate into the lesion, and partially express the neuronal phenotype in the host brain during 3 months after transplantation. The double labeling technique would be valuable to prove the proliferation of the transplanted cells in the host tissue because GFP gene and SPIO nanoparticles have different inheritance characteristics.

Fibrin matrix provides a suitable scaffold for bone marrow stromal cells transplanted into injured spinal cord: A novel material for CNS tissue engineering

Recent basic experiments have strongly suggested that cell transplantation therapy may promote functional recovery in patients with spinal cord injury (SCI). However, a safe and efficient transplantation technique still remains undetermined. This study, therefore, was aimed to clarify whether fibrin matrix could be a useful scaffold in bone marrow stromal cell (BMSC) transplantation for the injured spinal cord. To clarify the issue, three‐dimensional structure of fibrin matrix was assessed and the green fluorescent protein (GFP)‐expressing BMSC were cultured in fibrin matrix. The rats were subjected to spinal cord hemisection at T8 level, and the vehicle, BMSC or BMSC‐fibrin matrix construct was implanted into the cavity. Neurologic function was serially evaluated. Using immunohistochemistry, we evaluated the survival, migration and differentiation of the transplanted cells at 4 weeks after transplantation. In the initial in vitro study, the BMSC could survive in fibrin matrix for 2 weeks. The animals treated with the BMSC‐fibrin matrix construct showed significantly more pronounced recovery of neurologic function than vehicle‐ or BMSC‐treated animals. Fibrin scaffold markedly improved the survival and migration of the transplanted cells. There was no significant difference in the percentage of cells doubly positive for GFP and microtubule‐associated protein 2 between the animals treated with BMSC‐fibrin matrix construct and those treated with BMSC, but a certain subpopulation of GFP‐positive cells morphologically simulated the neurons in the animals treated with BMSC‐fibrin matrix construct. These findings strongly suggest that fibrin matrix may be one of the promising candidates for a potential, minimally invasive scaffold for injured spinal cord, and that such strategy of tissue engineering could be a hopeful option in regeneration therapy for patients with SCI.