Y Hirashima

Toyama University, Тояма, Toyama, Japan

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Publications (112)260.35 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: In elderly patients with aneurysmal subarachnoid hemorrhage (SAH), complications including vasosopasm, subdural effusion, and late hydrocephalus, are liable to occur even after aneurysmal surgery. We examined prospectively the efficacy of arachnoid plasty using fibrin glue membrane during surgery of ruptured aneurysms in the elderly patients for preventing complications. The effects on the modified Rankin scale (mRS) and the Glasgow outcome scale (GOS) 3 months after SAH were noted. Total of 31 patients aged more than 70 years selected from a consecutive series of patients with aneurysmal SAH, were divided into two groups alternately, a group with arachnoid plasty (n = 16) and a control group without arachnoid plasty (n = 15). Statistical analyses were performed to assess relationships among various clinical and neuroradiological variables, especially between arachnoid plasty and occurrence of symptomatic vasospasm, subdural effusion, late hydrocephalus, or outcome such as mRS and GOS 3 months after onset. Statistical analyses revealed that arachnoid plasty were associated with late hydrocephalus and subdural effusion negatively, but with better mRS at 3 months after SAH. A tendency to be associated with less frequent symptomatic vasospasm was also noted. Arachnoid plasty using fibrin glue is suggested to be effective in preventing complications associated with SAH and aneurysmal surgery. A better outcome in the elderly patients can be achieved.
    Acta Neurochirurgica 07/2006; 148(6):627-31; discussion 631. · 1.55 Impact Factor
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    ABSTRACT: Neuro-endoscopy is playing a greater role in the diagnosis and treatment of several types of lesions, especially in the ventricular system. However, surgical planning and intraoperative orientation during endoscopic surgery are sometimes difficult. The efficacy of a neurosurgical navigation system using three-dimensional computer graphics of magnetic resonance (MR) images in neuro-endoscopic surgery was evaluated in this study. We have developed a navigational endoscopic system designed to monitor the tip and direction of the endoscope, with the mirror marker of the navigation connected to a rigid endoscope. Eight patients, 3 cases of aqueductal stenting for isolated fourth ventricle, 3 cases of cystostomy for ependymal cyst, 1 case of septostomy for isolated lateral ventricle, and 1 case of ventricular tap in narrow ventricles, underwent endoscopic surgery using the present system. All patients underwent successful procedures with good outcomes. The present system was very useful in the cases of an accurate ventricular tap in narrow ventricles, identification of anatomic structures, and determining the appropriate route to the target point. This navigational endoscopic system improved the safety and accuracy of neuro-endoscopic surgery.
    min - Minimally Invasive Neurosurgery 09/2005; 48(4):197-201. · 0.62 Impact Factor
  • European Neurology 02/2005; 53(1):38-9. · 1.50 Impact Factor
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    ABSTRACT: Neuronavigation has become an effective therapeutic modality and is used routinely for intra-axial tumor removal. This retrospective study was conducted to evaluate the clinical impact of neuronavigation and image-guided extensive resection for adult patients with supratentorial malignant astrocytomas. Between 1990 and 2002, 76 adult patients with pathologically confirmed malignant astrocytomas underwent craniotomy and removal of the tumors at the Toyama Medical and Pharmaceutical University Hospital. Of these 76 patients, 42 were treated using neuronavigation with conventional microneurosurgery and the other 34 were treated with conventional microneurosurgery alone. Postoperative early MRI with contrast enhancement was done, and gross total resection was defined as the complete absence of residual tumor. Survival time was analyzed with the Kaplan-Meier method. Prognostic factors were obtained from the Cox proportional hazards model. In univariate analysis, age (< 65), grade 3, preoperative KPS (>/= 80), use of neuronavigation, and gross total resection were significantly associated with longer survival. However, when the data were submitted to multivariate analysis, grade 3, preoperative KPS (>/= 80), and gross total resection were independent prognostic factors. The median survival periods of patients receiving gross total resection (vs. partial resection) and neuronavigation (vs. no neuronavigation) were 16 (vs. 9) months and 16 (vs. 10) months, respectively. The percentage of a gross total resection was significantly higher in the neuronavigation group compared to that in the no-navigation group (64.3 % vs. 38.2 %, p < 0.05). Neurological deterioration occurred in 4 of 42 (9.5 %) and in 6 of 34 (17.6 %) patients after surgery with neuronavigation and surgery without neuronavigation, respectively, although this difference was not statistically significant. Our results showed that neuronavigation increases the radicality in the resection of malignant astrocytomas and is objectively useful for improving survival time.
    min - Minimally Invasive Neurosurgery 11/2004; 47(5):278-83. · 0.62 Impact Factor
  • Y Nishio, N Hayashi, H Hamada, Y Hirashima, S Endo
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    ABSTRACT: A 13-year-old female is presented. When she was six years old, she had fallen, holding wooden chopsticks and got stuck with a chopstick in the right upper eyelid. She was brought to a physician immediately, but a residual foreign body was missed and no particular symptom had developed during 7 years. She visited our department with fever and headache, and a brain abscess and an intracranial foreign body were found on computed tomography (CT) and magnetic resonance image (MRI) 7 years after the penetrating injury. She underwent removal of the object and abscess by craniotomy and recovered without neurological abnormalities. Since intracranial retained wooden foreign bodies frequently cause delayed complications of severe central nervous system infection, surgical removal is necessary even in the absence of symptoms.
    Acta Neurochirurgica 09/2004; 146(8):847-50. · 1.55 Impact Factor
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    ABSTRACT: A Kunitz-type protease inhibitor, bikunin, downregulates expression of uPA and its receptor uPAR at the mRNA and protein levels in several types of tumor cells. Our recent work showed that, using a cDNA microarray analysis, pregnancy-associated plasma protein-A (PAPP-A) is a candidate bikunin target gene. To clarify how reduced levels of PAPP-A may confer repressed invasiveness, we transfected human ovarian cancer cell line HRA with antisense (AS)-PAPP-A cDNA and compared the properties of the transfected cells to those of parental HRA cells. Here, we show that regulation of uPA mRNA and protein by IGF-I depends on the PI3K and MAPK signaling pathways and phosphorylation of Akt and ERK1/2 is required for IGF-I-mediated cell invasion; that IGFBP-4 protease in HRA cells is identified as PAPP-A; that reduced PAPP-A expression is associated with the upregulation of IGFBP-4 expression; that higher intact IGFBP-4 levels were associated with low invasive potential and growth rate in AS-PAPP-A cells in response to IGF-I; that IGF-I stimulates Akt and ERK1/2 activation of both the control and antisense cells, but the relative potency and efficacy of IGF-I were lower in the antisense cells compared to the control; and that genetic downregulation of PAPP-A reduces the proliferation, invasion and metastasis of HRA cells. In conclusion, our data identify a novel role for PAPP-A as a bikunin target gene. IGF-I-induced IGFBP-4 proteolysis by PAPP-A may enhance cell growth and invasion through IGF-I-dependent Akt and ERK1/2 activation and subsequently upregulation of uPA.
    International Journal of Cancer 05/2004; 109(3):336-47. · 6.20 Impact Factor
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    ABSTRACT: Neuronal degeneration within the brainstem has been reported in patients with impaired postural stability. However, the functional significance of these abnormalities is unknown at present. In the present study, we evaluated the relationship between the presence of pontine lacunae and postural stability measured by stabilometry. A total of 209 consecutive patients without neurological signs were divided into three groups according to the territory of lacunae on magnetic resonance imaging: (1) non-lacunar group, (2) pontine lacunar group, and (3) non-pontine lacunar group. Stabilometry was performed and statokinesigram measures including each Romberg quotient were compared among the three groups. Using multivariate analysis, postural stability was found to be disturbed in the pontine lacunar group compared with the other groups. The data of stabilometry in this group were compatible with disturbance of the central controlling system for keeping postural stability. Pontine lacuna is associated with patients with postural instability. This result may be related to the deterioration of the central coordination system for posture and locomotion.
    European Neurology 02/2004; 51(3):138-43. · 1.50 Impact Factor
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    ABSTRACT: Indices of the corpus callosum with normal aging and their sex differences were elucidated using quantitative MRI. We studied 94 Japanese men (mean+/-SD 57.3+/-20.8 years, range 6-90 years) and 111 Japanese women (mean+/-SD 61.2+/-17.6 years, range 9-86 years) who had no intracranial lesions on MRI and no history of neurological illness. The widths of the rostrum, body and splenium, the anterior to posterior length, and the maximum height in the midsagittal image were selected for measurement. The Evans index, which is the relative ratio of lateral ventricle expansion, and the maximum width of the third ventricle in the axial image were also estimated for comparison. The widths of rostrum, body and splenium of the corpus callosum became thinner with age. Conversely, the anterior to posterior length and the maximum height of the corpus callosum increased with age. The ratio of the width of the body to the length of the corpus callosum and the ratio of the width of the body to the height of the corpus callosum are best correlated with age. No sex differences in regional size of corpus callosum, including these two ratios, were observed in any raw measures, although ventricular indices were larger in men than women. Evaluation of the ratio of the width of the body to its length and the ratio of the width of the body to its height may enable accurate estimation of normal or pathological changes of the corpus callosum. Aging and pathological atrophy of corpus callosum can be evaluated without any adjustment for gender.
    Neuroradiology 09/2003; 45(8):513-8. · 2.70 Impact Factor
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    ABSTRACT: The processes of ovarian cancer dissemination are characterized by altered local proteolysis, cellular proliferation, cell attachment, and invasion, suggesting that the urokinase-type plasminogen activator (uPA) and its specific inhibitor (plasminogen activator inhibitor type-1 (PAI-1)) could be involved in the pathogenesis of peritoneal dissemination. We showed previously that expression of uPA and PAI-1 in the human ovarian cancer cell line HRA can be down-regulated by exogenous bikunin (bik), a Kunitz-type protease inhibitor, via suppression of transforming growth factor-beta1 (TGF-beta1) up-regulation and that overexpression of the bik gene can specifically suppress the in vivo growth and peritoneal dissemination of HRA cells in an animal model. We hypothesize that the plasminogen activator system in mesothelial cells can be modulated by HRA cells. To test this hypothesis, we used complementary techniques in mesothelial cells to determine whether uPA and PAI-1 expression are altered by exposure to culture media conditioned by HRA cells. Here we show the following: 1) that expression of PAI-1, but not uPA, was markedly induced by culture media conditioned by wild-type HRA cells but not by bik transfected clones; 2) that by antibody neutralization the effect appeared to be mediated by HRA cell-derived TGF-beta1; 3) that exogenous TGF-beta1 specifically enhanced PAI-1 up-regulation at the mRNA and protein level in mesothelial cells in a time- and concentration-dependent manner, mainly through MAPK-dependent activation mechanism; and 4) that mesothelial cell-derived PAI-1 may promote tumor invasion possibly by enhancing cell-cell interaction. This represents a novel pathway by which tumor cells can regulate the plasminogen activator system-dependent cellular responses in mesothelial cells that may contribute to formation of peritoneal dissemination of ovarian cancer.
    Journal of Biological Chemistry 08/2003; 278(29):26793-802. · 4.65 Impact Factor
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    ABSTRACT: Bikunin is a Kunitz-type protease inhibitor predominantly found in human amniotic fluid. In cancers, administration of bikunin may block tumor cell invasion by a direct inhibition of tumor cell-associated plasmin activity as well as by inhibiting urokinase-type plasminogen activator (uPA) expression at the gene and protein levels, possibly through suppression of CD44 dimerization and/or the MAP kinase signaling cascade. Treatment of cancer patients with bikunin may be beneficial in the adjuvant setting to delay the onset of metastasis development and/or in combination with cytotoxic agents to improve treatment efficacy in patients with advanced ovarian cancer.
    Biological Chemistry 06/2003; 384(5):749-54. · 2.96 Impact Factor
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    ABSTRACT: Bikunin, a Kunitz-type protease inhibitor, could potentially suppress tumor cell invasion and metastasis. Our previous study revealed that overexpression of bikunin in a human ovarian cancer cell line, HRA, resulted in a down-regulation in uPA and uPAR gene expression. For identifying the full repertoire of bikunin-regulated genes, a cDNA microarray hybridization screening was conducted using mRNA from bikunin-treated or bikunin-transfected HRA cells. A number of bikunin-regulated genes were identified, and their regulation was confirmed by Northern blot analysis. Our screen identified 11 bikunin-stimulated genes and 29 bikunin-repressed genes. The identified genes can indeed be classified into distinct subsets. These include transcriptional regulators, oncogenes/tumor suppressor genes, signaling molecules, growth/cell cycle, invasion/metastasis, cytokines, apoptosis, ion channels, extracellular matrix proteins, as well as some proteases. This screen identified suppression of several genes such as CDC-like kinase, LIM domain binding, Ets domain transcription factor, Rho GTPase-activating protein, tyrosine phosphorylation-regulated kinase, hyaluronan-binding protein, matriptase, and pregnancy-associated plasma protein-A (PAPP-A), which have previously been implicated in enhancing tumor promotion. Northern blot analysis confirmed that several genes including matriptase and PAPP-A were down-regulated by bikunin by approximately 9-fold. Further, genetic inhibition of matriptase or PAPP-A could lead to diminished invasion. These results show that bikunin alters the pattern of gene expression in HRA cells leading to a block in cell invasion.
    Journal of Biological Chemistry 05/2003; 278(17):14640-6. · 4.65 Impact Factor
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    ABSTRACT: Bikunin (bik), a Kunitz-type protease inhibitor, also known as urinary trypsin inhibitor, is proposed as a main participant in the inhibition of tumor cell invasion and metastasis, possibly through the direct inhibition of cell-associated plasmin activity and suppression of urokinase-type plasminogen activator (uPA) mRNA expression. In the present study, we transfected the human ovarian carcinoma cell line HRA, highly invasive cells, with an expression vector harboring a cDNA encoding for human bik. Our study was designed to investigate the effect of bik overexpression and changes in tumor cell phenotype and invasiveness in the stably transfected clones. Bik gene transfection of HRA gave the following results: 1) transfection of HRA with the bik cDNA resulted in 5 variants stably expressing functional bik; 2) bik(+) clones exhibited a significantly reduced uPA mRNA expression as compared to the parental cells; 3) bikunin negatively regulates the ERK1/2 activity; 4) secretion-blocking treatments of bik(+) clones abrogated bik-mediated suppression of ERK1/2 activation and uPA expression; 5) the regulation of invasion seen in the HRA cells is mainly mediated by the uPA-plasmin-MMP-2 system; 6) transfection of HRA with the bik gene significantly reduced invasion, but not proliferation, adhesion, or migration relative to the parental cells; and 7) animals with bik(+) clones induced reduced peritoneal dissemination and long term survival. We conclude that transfection of HRA cells with the bik cDNA constitutively suppresses ERK1/2 activation, which results in inhibition of uPA expression and subsequently reduces dissemination of bik(+) clones.
    International Journal of Cancer 05/2003; 104(3):289-302. · 6.20 Impact Factor
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    ABSTRACT: No marker that predicts accurately the time of occurrence of cerebral vasospasm due to subarachnoid hemorrhage (SAH) has been reported. In the present study, membrane-bound tissue factor (mTF) and myelin basic protein (MBP) concentrations in cerebrospinal fluid (CSF) were evaluated as a predictor of the time of occurrence of cerebral vasospasm. The mTF and MBP concentrations were measured in the CSF from 28 patients with SAH due to ruptured aneurysm. Serial assays were performed from day 4 to day 14 after SAH. CSF mTF and MBP concentrations from days 5 to 9 correlated with the volume of cerebral infarction due to vasospasm and outcome three months after SAH. From the serial assays, CSF mTF measurements predicted the time of occurrence and severity and irreversibility of symptoms due to vasospasm. In conclusion, CSF mTF is predictive of the occurrence and the recovery of cerebral vasospasm, while CSF MBP is only an indicator of severity of brain damage due to vasospasm.
    Neurological Research 11/2001; 23(7):715-20. · 1.18 Impact Factor
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    ABSTRACT: We reported a rare case of craniopharyngioma with chemical meningitis due to spontaneous rupture of the tumor. A 50-year-old woman was admitted with high fever, headache, and nausea. On physical examination, she had nuchal rigidity. The examination of her cerebral spinal fluid(CSF) revealed pleocytosis(mononuclear cell dominant), low value of glucose level and high content of protein. The feature of her CSF findings suggested tuberculosis or fungal meningitis, but bacteriologic culture of the CSF was negative. The CT scan showed an isodensity mass in the suprasellar region and a spotty calcification in the third ventricle. The MRI with gadolinium enhancement suggested that the tumor must be craniopharyngioma and that meningitis was a type of chemical meningitis due to spontaneous rupture of craniopharyngioma. The corticosteroid therapy was rather effective to the symptoms of fever and headache. Then the operation was performed by neurosurgeons, and the diagnosis of craniopharyngioma was pathologically confirmed. Spontaneous rupture of craniopharyngioma rarely occurred and was followed by chemical meningitis. This case was an extremely rare condition that presented with chemical meningitis as an initial symptom.
    Nō to shinkei = Brain and nerve 11/2001; 53(10):957-60.
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    ABSTRACT: Abnormal ECG changes are frequently observed in patients with subarachnoid hemorrhage (SAH). Recently, evidence has been obtained that right insular cortex mediates sympathetic cardiovascular effects. We therefore assessed the laterality and location of SAH dominance in inducing cardiovascular changes as measured by ECG, blood pressure, and heart rate. After exclusion of 11 SAH patients who died within 1 month after onset, we studied 118 consecutive patients. Data were obtained from records of blood pressure and pulse on admission. Abnormal ECG changes were determined from ECGs on admission and almost 1 month later. From brain CT scans performed immediately after admission, the amount of SAH in each of the 8 cisterns and fissures was measured semiquantitatively. Twenty-six patients had abnormal changes on admission ECG, while 92 patients did not. Systolic blood pressure, diastolic blood pressure, and the amounts of blood in the left ambient cistern, left suprasellar cistern, quadrigeminal cistern, right ambient cistern, right suprasellar cistern, right sylvian fissure, and the set of all cisterns were significantly greater in the group with ECG change than in the group without ECG change. Multivariate logistic regression analysis with stepwise method indicated that systolic blood pressure >160 mm Hg (P=0.0006) and the amounts of SAH in the quadrigeminal cistern (P=0.022) and right sylvian fissure (P=0.0019) were independently associated with abnormal ECG change. Cardiac consequences are possible in patients with massive right sylvian fissure SAH or when systolic blood pressure is >160 mm Hg.
    Stroke 10/2001; 32(10):2278-81. · 6.16 Impact Factor
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    ABSTRACT: We report a pediatric case of acute cerebellitis with hydrocephalus requiring emergency placement of external ventricular drainage. A 7-year-old boy presented with acute development of headache, nausea and vomiting. Magnetic resonance (MR) examination revealed obstructive hydrocephalus and marked bilateral cerebellar swelling on T2-weighted imaging. After the placement of external ventricular drainage, symptoms of intracranial hypertension promptly improved, and other clinical and radiological abnormalities gradually resolved following intravenous injection of corticosteroids. Surgical treatment and timing in the treatment of acute cerebellitis are discussed.
    Child s Nervous System 09/2001; 17(8):500-2. · 1.24 Impact Factor
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    ABSTRACT: Glassy cell carcinoma (GCC) of the uterine cervix is a highly malignant tumor and has a poor prognosis. As yet, no effective systemic chemotherapy to this tumor has been reported. Here we describe a case of recurrent GCC that responded to paclitaxel and carboplatin combination treatment. The patient, a 32-year-old woman, with clinical staging FIGO IB1 disease had a radical hysterectomy and postoperative radiotherapy. Three months after initial treatment, she had a relapse as peritoneal dissemination, which was confirmed in the second surgery (adnectomy) and which did not respond to platinum-based conventional chemotherapy (cisplatin, adriamycin, cyclophosphamide and carboplatin, etoposide). The recurrent peritoneal tumors responded well to paclitaxel and carboplatin combination treatment. An elevated serum concentration of carcinoembryonic antigen (672 ng/ml) was reduced to 14.4 ng/ml by six such courses. Peritoneal histopathology confirmed a complete response in the third surgery (ileostomy) for adhesive ileus by the radiotherapy. This is the first report of effective systemic chemotherapy with paclitaxel and carboplatin to recurrent GCC of the uterine cervix.
    Anti-Cancer Drugs 09/2001; 12(7):627-30. · 2.23 Impact Factor
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    ABSTRACT: Efficient and prolonged foreign gene expression has been demonstrated in the bilateral anterior horn motor neurons of the spinal cord by intramuscular inoculation with attenuated herpes simplex virus (HSV) expressing latency associated transcript promoter-driven beta-galactosidase (betaH1). To examine the effect of immunity on the gene delivery, betaH1 was applied in rats immunized subcutaneously or intramuscularly with the parent HF strain. Rats were immunized subcutaneously with HF strain and 28 days later when the high antibody titer was maintained, betaH1 was inoculated into the right gastrocnemius muscle. Second, 35 days after inoculation with HF strain into the right gastrocnemius muscle, betaH1 was inoculated at the same site. In both ways of immunization, immunity did not abolish or prevent the transgene expression in the anterior horn motor neurons, but attenuated the range and the number of the beta-galactosidase-positive neurons from about 85% to 50-65% on 28 days after inoculation with betaH1. However, beta-galactosidase activity was observed in a wide range of the bilateral anterior horn motor neurons without significant pathological changes. These findings support the feasibility of the attenuated HSV vector in gene delivery into the central nervous system, even in the presence of immunity.
    Gene Therapy 09/2001; 8(15):1180-7. · 4.32 Impact Factor
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    ABSTRACT: The efficacy of a neurosurgical navigation system using three-dimensional composite computer graphics (CGs) of magnetic resonance (MR) and computed tomography (CT) images was evaluated in skull base surgery. Three-point transformation was used for integration of MR and CT images. MR and CT image data were obtained with three skin markers placed on the patient's scalp. Volume-rendering manipulations of the data produced three-dimensional CGs of the scalp, brain, and lesions from the MR images, and the scalp and skull from the CT. Composite CGs of the scalp, skull, brain, and lesion were created by registering the three markers on the three-dimensional rendered scalp images obtained from MR imaging and CT in the system. This system was used for 14 patients with skull base lesions. Three-point transformation using three-dimensional CGs was easily performed for multimodal registration. Simulation of surgical procedures on composite CGs aided in comprehension of the skull base anatomy and selection of the optimal approaches. Intraoperative navigation aided in determination of actual spatial position in the skull base and the optimal trajectory to the tumor during surgical procedures.
    Neurologia medico-chirurgica 08/2001; 41(7):335-9. · 0.49 Impact Factor
  • S Endo, N Hayashi, Y Hirashima
    No shinkei geka. Neurological surgery 08/2001; 29(7):605-15. · 0.13 Impact Factor

Publication Stats

1k Citations
260.35 Total Impact Points


  • 2006
    • Toyama University
      Тояма, Toyama, Japan
  • 1981–2005
    • Toyama Medical and Pharmaceutical University
      Тояма, Toyama, Japan
  • 1996–2004
    • Hamamatsu University School of Medicine
      • Department of Obstetrics and Gynecology
      Hamamatu, Shizuoka, Japan
  • 1989–1999
    • The Ohio State University
      • Department of Molecular and Cellular Biochemistry
      Columbus, OH, United States
  • 1998
    • Miyazaki Prefectural Nursing University
    • University of Hamamatsu
      Hamamatu, Shizuoka, Japan
  • 1995
    • Teikyo University
      • Faculty of Pharmaceutical Sciences
      Tokyo, Tokyo-to, Japan