Biomedical subjects

Takeshi Miyazaki

Publications and source records attributed to Takeshi Miyazaki.

10 recordsLinked to original sources

PubMed2006

Feasibility of using a human nucleus pulposus cell line as a cell source in cell transplantation therapy for intervertebral disc degeneration.

STUDY DESIGN: Assessment of the potential use of an immortalized human nucleus pulposus cell line as an alternative cell source in cell transplantation therapy for intervertebral disc degeneration. OBJECTIVES: To evaluate the effect of transplanting the human nucleus pulposus cell line into a disc degeneration model in rabbits and to define whether it is capable of becoming an alternative cell source for cell transplantation therapy for disc degeneration. SUMMARY OF BACKGROUND DATA: Interest in cell transplantation therapy for disc degeneration has been growing for several years, and a range of different cell types have been examined as possible donor cells. In addition, the establishment of a novel cell line that possesses some of the major characteristics of a normal human nucleus pulposus cells has been reported. METHODS: Human nucleus pulposus cell line was established, and cells were transplanted into a rabbit disc degeneration model. At 4, 8, and 24 weeks after transplantation, inhibition of intervertebral disc degeneration was assessed by examining the disc height, macroscopic appearance, histologic findings, and immunohistochemistry. In addition, aggrecan, versican, and Type II collagen gene expression in the nucleus pulposus were measured semiquantitatively at the mRNA level. Furthermore, the survival of transplanted cells was examined using immunohistochemistry for Simian Virus 40 T antigen, and the presence of graft-versus-host reaction was assessed by immunohistochemistry for CD4 and CD58. RESULTS: The disc height was significantly greater in the transplanted group than in the degenerative group's disc from 4 weeks' posttransplantation. Macroscopically, the nucleus pulposus was absent and there was loss of disc height in the degenerative group at 24 weeks after transplantation, whereas the nucleus pulposus was preserved in the transplanted group. Histologic examination showed that the structure of the inner anulus fibrosus was significantly preserved in the transplanted group, and the boundary between the nucleus and anulus could be clearly visualized. Expression of mRNAs of the nucleus pulposus matrix, aggrecan, and Type II collagen was significantly greater in the transplanted group than in the degenerative group. This indicates that transplantation of human nucleus pulposus cell line helped to preserve the matrix of the nucleus pulposus. Thus, transplantation of a human nucleus pulposus cell line was shown to delay disc degeneration in this rabbit model. CONCLUSION: The human nucleus pulposus cell line may become an alternative cell source for cell transplantation therapy of intervertebral disc degeneration.

Adult↗

PubMed2006

The key to improving prognosis for aneurysmal subarachnoid hemorrhage remains in the pre-hospitalization period.

BACKGROUND: Despite advances in neurosurgical management, aneurismal subarachnoid hemorrhage (aSAH) still has high mortality and morbidity. This study aimed to clarify how delaying hospital admission after aSAH contributes to worse prognosis even today and to find the possibility for an improvement of its prognosis by early admission. METHODS: Four hundred twenty-one consecutive patients are the basis for this study. Cause of delay was classified into 5 categories: patient delay (PD), doctor delay (DD), transportation delay (TD), no delay (ND) (within 2 hours of onset), and others. Condition of each patient was assessed at time of onset and admission using H&K. The relationships between cause of delay and worsening of Hunt and Kosnik grading (H&K) were examined. RESULTS: The median delay time was 1.7 days. Only 41% of patients visited our institution without delay. Admission delay, especially PD and DD, exhibited a significant correlation to worsening of H&K. In addition to nondirect admission, misdiagnosis or delayed diagnosis contributed significantly to worsening of H&K. Incidence of DD has declined in recent years, whereas that of PD has increased. Consequently, no change in total number of delays was found. CONCLUSIONS: There remains much room for an improvement of prognosis for aSAH by early admission. We need to fully realize this reality and to directly face this problem.

Admitting Department, Hospital↗

PubMed2006

[Clinical efficacy and cost benefit of oral antimicrobial prophylaxis with levofloxacin on neurological surgery].

OBJECTIVE: The clinical efficacy and cost benefit of oral antimicrobial prophylaxis with levofloxacin (LVFX) on neurosurgical operation were evaluated. PATIENTS AND METHODS: Fifty patients undergone burr hole drainage for chronic subdural hematoma were enrolled into this study. These patients had preoperative intravenous drip infusion of 1.0 g of cefazolin (CEZ), and were given oral 200 mg of LVFX twice a day for postoperative 6 days on their operations. Clinical effect on prophylaxis of postsurgical infection and surgical site infection as well as safeness of the drug were assessed. Their clinical course were retrospectively compared with another fifty patients as control group who had intravenous administration of CEZ for consecutive 7 days on same operation. RESULTS: There were no patients who had postsurgical infection and surgical site infection as well as drug related adverse effect, whereas three patients in control group suffered urinary infections or respiratory tract infection during their postsurgical course. CONCLUSIONS: Less invasive oral antimicrobial prophylaxis with LVFX is effective to prevent postoperative infections and surgical site infections, and attractive from the medical economic point of view.

Administration, Oral↗

PubMed2005

Low-intensity pulsed ultrasound stimulates cell proliferation and proteoglycan production in rabbit intervertebral disc cells cultured in alginate.

Intervertebral disc degeneration, one of the major causes of low-back pain, is known to result from alteration in biosynthesis of proteoglycan in the disc. Therefore, upregulating the synthesis of proteoglycan in intervertebral disc cells may be one approach in treating disc degeneration. Based on the finding that low-intensity pulsed ultrasound stimulates proteoglycan synthesis in rat chondrocytes, we investigated whether low-intensity pulsed ultrasound stimulates biological properties of rabbit intervertebral disc cells in vitro. Nucleus pulposus cells and annulus fibrosus cells isolated from rabbits were cultured in alginate beads. Cells were stimulated for 20 min each day for 5-12 days, starting on the third day after seeding. An ultrasound signal consisting of a 200 micros burst sine wave of 0.5 MHz repeating at 1 kHz, with an intensity of 0, 7.5, 15, 30, 60, 120 mW/cm2 spatial and temporal average, was applied. DNA and proteoglycan synthesis were evaluated by measuring [3H]-thymidine and [35S]-sulfate incorporation. DNA and proteoglycan content in beads were measured by Hoechst 33258 dye method and dimethylmethylene blue assay. Results demonstrated positive effects on DNA synthesis and content, following low-intensity pulsed ultrasound stimulation with intensities of 7.5 and 15 mW/cm2. Furthermore, ultrasound stimulation significantly upregulated [35S]-sulfate incorporation and proteoglycan content compared to the control group, following 5 days of stimulation in both nucleus pulposus and annulus fibrosus cells. These findings suggest the possible application of low-intensity pulsed ultrasound in biological repair of intervertebral disc degeneration.

Alginates↗

PubMed2005

Unusual progression of pleomorphic adenoma of the lacrimal gland: case report.

A 72-year-old female complained of acute pain on left eye movement followed by progressive exophthalmos. Neuroimaging revealed a large well-demarcated lesion consisting of solid and cystic parts, as well as bone destruction and hemorrhage, within the left orbital cavity. The preoperative diagnosis was pleomorphic adenoma with or without malignant transformation, or cavernous angioma. En bloc excision including adjacent tissues was planned to resolve the progressive symptoms and to obtain a histological diagnosis. The transcranial route was chosen since tumor invasion to the cranial base was possible. The histological diagnosis was pleomorphic adenoma. Pathological and preoperative radiological examinations indicated that repeated intratumoral hemorrhage had caused the orbital bone destruction and acute orbital pain. Neoplasms should be differentiated from a wide spectrum of other possible pathologies. Accurate clinical diagnosis of neoplasm in the orbital cavity is important for correct therapeutic management. Malignancy is generally suspected if painful and progressive signs and symptoms are associated with an orbital mass lesion. The present case suggests that pleomorphic adenoma should also be considered in the differential diagnosis. The therapeutic strategy for lacrimal gland tumors remains controversial, so a flexible management approach is required.

Adenoma, Pleomorphic↗

PubMed2004

Immortalization of human nucleus pulposus cells by a recombinant SV40 adenovirus vector: establishment of a novel cell line for the study of human nucleus pulposus cells.

STUDY DESIGN: Establishment and characterization of a de novo cell line derived from human nucleus pulposus cells using a recombinant simian virus 40 (SV40) adenovirus vector. OBJECTIVES: To assess the feasibility of human nucleus pulposus cell line procurement and to evaluate the character of the resultant outcome to better understand the nature of human nucleus pulposus cells. SUMMARY OF BACKGROUND DATA: Despite recent advances in disc cell biologic research, the fundamental nature of nucleus pulposus cells, especially in the context of human cell lines, is still not well understood. Therefore, a broad-based analysis of these cells is of significant necessity. Because of the limited amount of existing human cells, establishment of an immortal cell line would greatly facilitate resource supply. METHODS: After release of informed consent, tissue samples of nucleus pulposus were obtained from the lumbar intervertebral disc of a 19-year-old man undergoing anterior fusion for burst fracture. Samples with no apparent damage were selected and digested enzymatically for primary culture and then were infected with recombinant SV40 adenovirus vector (Ad/SV40). The infected cells were maintained in culture for more than 40 population doublings, after which they were considered immortalized. Next, confirmation of expression of T antigen was performed and resultant immortalized cell lines were designated and classified as human nucleus pulposus cell line derived from Ad/SV40 infection-1 (HNPSV-1). HNPSV-1 cells were characterized and compared with their mother cells under two designated culture conditions: monolayer and three-dimensional. Morphologic and immunocytochemical analyses were performed at various intervals. Cell proliferation, DNA synthesis, proteoglycan synthesis, gene expression profiling, and karyotypic analyses were also performed. Moreover, HNPSV-1 cells were injected into rabbit discs to assess the presence of tumorigenesis. RESULTS: Recombinant SV40 adenovirus vector infected nucleus pulposus cells with relatively high efficiency (90%> at multiplicity of infection 100). HNPSV-1 demonstrated marked prolongation of cell life with continuous cell doublings for over 5 months (60-100 cell population doublings). Despite significant increase in cell proliferation and DNA synthesis when compared with its mother cells, resultant cell lines expressed strikingly similar cell morphology and functional characteristics. Atypical karyotypes were noted; however, no apparent tumorigenesis was seen in rabbit discs 24 weeks after injection of HNPSV-1. CONCLUSIONS: HNPSV-1 was successfully established using recombinant SV40 adenovirus vector. Results showed that human nucleus pulposus cells are capable of immortalization with maintenance of original cell characteristics. It is anticipated that these cells will be useful for in vitro studies of the biologic nature of human nucleus pulposus cells.

Adenoviruses, Human↗

PubMed2004

Extracranial vertebral artery aneurysm ruptured into the thoracic cavity with neurofibromatosis type 1: case report.

OBJECTIVE AND IMPORTANCE: We are sometimes involved in the care of patients with neurofibromatosis Type 1 because of the associated disorders of cervicocerebral vessels. However, extracranial vertebral artery aneurysm in neurofibromatosis Type 1 is very rare. We present the first reported case of a rupture of an extracranial vertebral artery aneurysm into the thoracic cavity in a patient with neurofibromatosis Type 1. CLINICAL PRESENTATION: A 52-year-old woman who presented with a decrease in left-sided grip and numbness of the left upper limb was admitted. During history taking, she developed shock. Radiological examination revealed that a left extracranial vertebral artery aneurysm had ruptured into the thoracic cavity. With consciousness decreasing gradually because of hemorrhagic shock, the patient became comatose. INTERVENTION: Balloon occlusion of the vertebral artery proximal to the aneurysm was performed and surgical ligation was attempted, but cardiac arrest occurred immediately after the beginning of surgery, and the patient died. The vertebral artery proximal to the aneurysm was removed for pathological examination. CONCLUSION: In this case, the changes noted were interpreted as changes showing fragility of the vascular wall secondary to neurofibromatosis Type 1. Patients with neurofibromatosis Type 1 exhibit disorders of cervicocerebral vessels, and in some cases progression may follow a violent course. Periodic follow-up of such patients and early diagnosis are important.

Aneurysm, Ruptured↗

PubMed2004

A case of unknown origin subarachnoid hemorrhage immediately following drainage for chronic subdural hematoma.

A 56-year-old man treated with anticoagulants complained of a gradually worsening headache. A left chronic subdural hematoma (CSH) was shown by head computed tomographic (CT) scans and the operation, one burr hole surgery under local anesthesia, itself was performed uneventfully. However, immediately after we began draining the hematoma at the patient's bedside, the patient complained of a sudden headache. CT scans showed a subarachnoid hemorrhage (SAH). Cerebral angiography was immediately performed, but the source of hemorrhage could not be found. The next day, a CT scan showed that most of the SAH had disappeared. To our knowledge, there are no previous reports of SAH of unknown origin following surgery for CSH. The likely mechanism for the occurrence of the SAH, in addition to a coagulopathy due to anticoagulant therapy, could include the possibility that the drainage of the hematoma produced a movement of the hemisphere along with hyperperfusion that resulted in the rupture of a weak subarachnoid vessel, such as a perforating artery.

Drainage↗

PubMed2004

[Evaluation of brain tumors by simultaneous dual isotope SPECT with 201Tl-chloride and 99mTc-MIBI].

Single photon emission computed tomography (SPECT) is useful for detecting brain tumors. In this study, we evaluated the utility of simultaneous dual SPECT with 201Tl-Chloride (Tl) and 99mTc-MIBI (MIBI) for diagnosis of brain tumors. We evaluated 20 cases, including 2 glioblastomas, 7 anaplastic astrocytomas, 2 oligodendrogliomas, 2 anaplastic ependymomas, 2 medulloblastomas, 2 meningiomas, 1 malignant meningioma, 1 pituitary adenoma, and 1 craniopharyngioma. We analyzed the uptake ratio (T/N ratio) of tracers in both Tl and MIBI at max counts/pixels ratio in the region of interest. The T/N ratios in early and delayed images were described as early ratios (ER) and delay ratios (DR), respectively. The retention index (RI) was calculated as the DR/ER ratio. Significant correlations were found between ER and DR for both Tl (DR = 0.797 * ER + 0.359, r = 0.871), and MIBI (DR = 0.961 * ER - 0.191, r = 0.784). Next, we analyzed the correlations between Tl and MIBI SPECT, for ER, DR, and RI. ER values for the two were strongly correlated (r = 0.791), DR values were weakly correlated (r = 0.556), and RI exhibited no correlation between them (r = 0.328). There were no correlations between tumor volume and T/N ratio for the two (ER-Tl; r = 0.0095, DR-TI; r = 0.0050, ER-MIBI; r = 0.036, DR-MIBI; r = 0.254). Lastly no correlation was found between RI-Tl and RI-MIBI (r = 0.328). We discuss the difference in the mechanism of accumulation of two tracers and the significance of simultaneous dual SPECT using them for the differential diagnosis of pituitary tumors, regrowth of oligodendrogliomas, and multidrug resistance of chemotherapy. Dual SPECT with Tl and MIBI appears to be useful for the diagnosis of brain tumor.

Adenoma↗

PubMed2003

Growth factor array fabrication using a color ink jet printer.

We have developed a novel method for growth factor analysis using a commercial color ink jet printer to fabricate substrata patterned with growth factors. We prepared substrata with insulin printed in a simple pattern or containing multiple areas of varying quantities of printed insulin. When we cultured the mouse myoblast cell line, C2C12, on the insulin-patterned substrata, the cells were grown in the same pattern with the insulin-printed pattern. Cell culture with the latter substrata demonstrated that quantity control of insulin deposition by a color ink jet printer is possible. For further applications, we developed substrata with insulin-like growth factor-I (IGF-I) and basic fibroblast growth factor (bFGF) spotted in 16 different areas in varying combinations and concentrations (growth factor array). With this growth factor array, C2C12 cells were cultured, and the onset of muscle cell differentiation was monitored for the expression of the myogenic regulator myogenin. The ratio of cells expressing myogenin varied with the doses of IGF-I and bFGF in the sections, demonstrating a feasibility of growth factor array fabrication by a color ink jet printer. Since a printer manipulates several colors, this method can be easily applied to multivariate analyses of growth factors and attachment factors affecting cell growth and differentiation. This method may provide a powerful tool for cell biology and tissue engineering, especially for stem cell research in investigating unknown conditions for differentiation.

Animals↗