Satoshi Iwabuchi

National Cancer Center, Tokyo, Tokyo-to, Japan

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Publications (29)22.18 Total impact

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    ABSTRACT: In 1999, a 50-year-old woman underwent ventriculoperitoneal (VP) shunt surgery for hydrocephalus after subarachnoid hemorrhage. She was hospitalized for fever and recurrent systemic seizures in November 2006. Head computed tomography (CT) showed only old changes. The seizures and fever were controlled by medicinal therapy. However, in December, her consciousness level suddenly decreased, and she showed progressive lower abdominal distension. Head CT showed marked ventriculomegaly, and abdominal CT showed a giant cystic mass at the shunt-tube tip in the lower abdominal cavity. Because thick pus was aspirated from the intra-abdominal mass, we diagnosed the patient with acute obstructive hydrocephalus due to an infected abdominal pseudocyst. Laparotomy and direct cyst drainage were performed, and antibiotic therapy against Streptococcus, the causative pathogen, was administered. The VP shunt tube was replaced. The postoperative course was uneventful, and postoperative CT showed hydrocephalus improvement and no pseudocyst recurrence. Abdominal pseudocysts, which are rare after VP shunt surgeries, usually occur after the subacute postoperative course in younger cerebral hemorrhagic cases. Our case was quite rare because the cyst developed in the chronic phase in an older patient and was caused by streptococcal infection. The cyst components should be examined before cyst drainage when choosing surgical strategies.
    Surgery Research and Practice. 01/2014; 2014(898510).
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    ABSTRACT: A 54-year-old woman presented to our hospital with progressive motor weakness of the right arm. She had a medical history of systemic lupus erythematosus (SLE) and hypothyroidism. Magnetic resonance imaging indicated a watershed infarction of the left hemisphere. Cervical echogram indicated severe stenosis of the internal carotid artery (ICA) without wall thickening. Cerebral angiography indicated left ICA occlusion, development of unilateral moyamoya vessels, and leptomeningeal anastomosis. Encephaloduroarteriosynangiosis (EDAS) was performed after cerebral (99) (m)Technetium-ethyl-cysteinate-dimer single-photon emission computed tomography indicated a decreased cerebral blood flow, diminished cerebrovascular perfusion reserve. Motor weakness finally disappeared 6 months after surgery. Moyamoya syndrome is a rare complication of both SLE and hypothyroidism, and the surgical indication remains controversial. By evaluating the decreased cerebral perfusion reserve capacity and the existence of leptomeningeal anastomosis, EDAS could be an efficient method for the treatment of moyamoya syndrome associated with SLE and hypothyroidism.
    Case Reports in Medicine 01/2012; 2012:120867.
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    ABSTRACT: we investigated the clinical efficacy of intra-arterial administration of fasudil hydrochloride for cerebral vasospasm. we reviewed 90 cases treated with intra-arterial administration of fasudil hydrochloride between August 1998 and April 2009 and investigated the clinical efficacy for cerebral vasospasm. angiographic improvement of vasospasm was noted in all procedures. Eight had ischemic lesion on CT at discharge in Group A, which included 39 patients who presented angiographic and symptomatic vasospasm. However, 4 (50%) of these eight were recovered with a condition of GR. No patients showed ischemic lesion on CT in Group B, which included 51 patients who presented angiographic vasospasm without symptoms. Two (3.3%) of 59 patients who presented angiographic vasospasm without symptoms at the initial follow-up angiography had ischemic lesion on CT at discharge. The 1-year follow-up showed 78.9% of GR. No patient showed any adverse effects resulting from intra-arterial administration of fasudil hydrochloride. intra-arterial administration of fasudil hydrochloride was an effective and safe management technique for vasospasm.
    Acta neurochirurgica. Supplement 01/2011; 110(Pt 2):179-81.
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    ABSTRACT: A 14-year-old was girl admitted to our hospital with a subcutaneous mass of the occipital head. The mass had grown for 6 years, after she had sustained a head injury at the age of 6, and was located directly under a previous wound. Skull X-ray Photograph (xp), computed tomography (CT), and magnetic resonance imaging (MRI) showed a bony defect and cystic changes in the skull corresponding to a subcutaneous mass. Bone scintigraphy revealed partial accumulation. The patient underwent total removal of the skull mass, and the diagnosis from the pathological findings of the cyst wall was fibrous dysplasia (FD). The radiographic findings for cystic cranial FD can be various. Progressive skull disease has been reported to be associated with head trauma, but the relationship between cranial FD and head trauma has not been previously reported. Previous studies have suggested that c-fos gene expression is a key mechanism in injury-induced FD.
    Case Reports in Medicine 01/2011; 2011:680401.
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    ABSTRACT: In recent years, incidence of invasive fungal infection has been increasing, mostly due to advances in + medicine that may produce immunocompromised individuals. Candidial infection in the central nervous system (CNS) is one of the most serious forms of blood stream infection of Candida sp. and mortality is known to be more than 50%. In this research, we employed 27 autopsies with confirmed in vasive CNS yeast infection which were confirmed. In addition to detailed morphological analysis of yeast cells in lesions, in situ hybridization was carried out with an originally designed Candida-specific peptide nucleic acid (PNA) probe to identify the candidial infection of each patient. This was followed by histopathological investigation: invasiveness, shape, and distribution of yeast or yeasts with pseudohyphal growth, and a study regarding the correlation between histological characteristics and number of leukocytes in the peripheral blood just before death. Results showed that the, supratentorial region was the most common area of disseminated candidial infection in CNS, and that density was highest in the cerebral gray matter followed by the white matter and basal ganglia. On the other hand, regarding the lesions developed in the cortical area, the average distance from the brain surface was 4.026 mm. This area corresponding to the deeper cortex has a characteristic arterial structure that refers hairpin curving reverse. The structure may contribute to the high incidence of candidial foci in the deeper cortex, because of the increase in shear stress.
    Nippon Ishinkin Gakkai Zasshi 01/2010; 51(1):31-45.
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    ABSTRACT: Two patients were treated for intracranial infections involving methicillin-resistant Staphylococcus aureus (MRSA). A 30-year-old woman was admitted to our hospital for intracerebral hemorrhage related to arteriovenous malformation. After decompressive craniectomy, the patient developed an epidural abscess. MRSA was isolated from the pus culture. The infection did not improve after intravenous vancomycin (VCM) administration for 15 days. However, after administration of linezolid (LZD) for 14 days, the infection had improved, and the white blood cell count and C-reactive protein values had normalized. A 53-year-old woman had previously undergone 3 operations for craniopharyngioma before the age of 35 years. She was admitted to our hospital with fever and disturbance of consciousness. Magnetic resonance imaging with contrast medium revealed a brain abscess caused by MRSA. After 14 days of intravenous administration of VCM, the infection had not improved and intravenous administration of LZD was initiated. After administration of LZD for 14 days intravenously and 14 days orally, the infection had improved, and the white blood cell count and C-reactive protein values had normalized. VCM is highly effective against MRSA infection, but penetration into the central nervous system (CNS) is poor. LZD has good CNS penetration, so should be considered for secondline antibiotic therapy for VCM-resistant intracranial MRSA infection.
    Neurologia medico-chirurgica 01/2010; 50(6):515-7. · 0.49 Impact Factor
  • Neurologia Medico-chirurgica - NEUROL MED-CHIR. 01/2010; 50(6):515-517.
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    ABSTRACT: As methods of cancer diagnosis and treatment improve, interest in metastatic brain tumors continues to increase. In the present study, we attempted to characterize genetically the dynamic changes occurring during brain metastasis formation by DNA microarray, and attempted to compare these findings with histological observations. Lewis lung carcinoma cells were injected into C57BL/6Ncrj mice carotid arteries. The mice were sacrificed at days 1-9 after injection. We performed histological observation and genome-wide expression profiling using a DNA microarray. In histological observation, tumor cells were observed in capillary vessels at day 1 after injection. At day 3, the tumor cells had begun to proliferate. At day 6, the metastatic foci showed "perivascular proliferations". Next, we performed a pairwise comparison of gene expression microarray data from day 1 to day 9 after injection. The first major change occurred between Phase Two and Phase Three. When hierarchical clustering was performed between different samples using the 867 genes, they could be classified into identical clusters for days 1 and 2, identical clusters for day 3 to day 5, and identical clusters for day 6 to day 9. For time course analysis, we extracted 623 genes by the pairwise comparison. By using the quality threshold (QT) nonhierarchical clustering method, we identified 37 expression patterns. These patterns can be separated into eight clusters by using the k-means method. The microarray results reported here strongly suggest that a large number of genes exhibit a spike pattern, which is tantamount to phase-specific expression.
    Neuropathology 12/2008; 29(4):389-97. · 1.91 Impact Factor
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    ABSTRACT: As methods of cancer diagnosis and treatment progress, interest in metastatic brain tumours continues to increase. There are many studies using various methods of animal model and we considered that each model reflects different pathological processes because of the unique composition of the brain. We prepared metastatic brain tumour models using three different methods. In this study, we attempted to elucidate the roles of the pia mater in brain metastasis. The metastatic foci showed an angiocentric pattern, forming collars of neoplastic cells, and were designated 'perivascular proliferations'. Furthermore, we observed neoplastic cells that infiltrated the brain parenchyma, the border of which had become indistinct. These were labelled 'invasive proliferations'. The internal carotid artery injection model reflects haematogenous metastasis. In this model, both perivascular and invasive proliferations were observed. The intrathecal injection model reflects leptomeningeal carcinomatosis. In this model, metastasis to the meninges was observed. In the stereotactic injection model, the tumour proliferation at the injection site and the infiltration into the brain parenchyma were observed. The pia-glial membrane serves as a scaffold when neoplastic cells spread to the perivascular space forming angiocentric pattern. The pia-glial membrane is found between the brain parenchyma and blood vessels. Blood vessels penetrate the brain through tunnels known as perivascular spaces that are covered by pia mater. Three different methods which we prepared reflect three different pathological processes. Our findings suggest that the pia mater is a critical factor in brain metastasis.
    International Journal of Experimental Pathology 03/2008; 89(1):38-44. · 2.04 Impact Factor
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    ABSTRACT: Abstract Background We evaluated regional cerebral blood flow (rCBF) during vasospasm after subarachnoid haemorrhage (SAH) using automated voxel-based analysis of brain perfusion single-photon emission computed tomography (SPECT). Method Brain perfusion SPECT was performed 7 to 10 days after onset of SAH. Automated voxel-based analysis of SPECT used a Zscore map that was calculated by comparing the patient’s data with a control database. Findings In cases where computed tomography (CT) scans detected an ischemic region due to vasospasm, automated voxel-based analysis of brain perfusion SPECT revealed dramatically reduced rCBF (Z-score ≤ −4). No patients with mildly or moderately diminished rCBF (Z-score> −3) progressed to cerebral infarction. Some patients with a Z-score≤ −4 did not progress to cerebral infarction after active treatment with angioplasty. Three-dimensional images provided detailed anatomical information and helped us to distinguish surgical sequelae from vasospasm. Conclusions In conclusion, automated voxel-based analysis of brain perfusion SPECT using a Z-score map is helpful in evaluating decreased rCBF due to vasospasm.
    Acta neurochirurgica. Supplement 01/2008; 104:219-223.
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    ABSTRACT: There have been very few reports in Japan of patients with allergic fungal sinusitis (AFS). We describe two cases caused by Bipolaris spicifera and Schizophyllum commune. The patients were a 70-year-old male (Case 1) and a 55-year-old female (Case 2). Both presented with nasal obstruction and purulent nasal discharge. CT scans revealed each to have a soft tissue mass extending from the ethmoid sinus to the sphenoid sinus. In addition, pathological studies on the contents of the paranasal sinuses of both patients revealed the presence of fungal elements in the allergic mucin. Microbiological studies resulted in the recovery of Bipolaris spicifera from Case 1 and Schizophyllum commune from Case 2. To date there have been no reports of AFS due to these two fungi in Japan. It is very important in the diagnosis of AFS to demonstrate the presence of fungal elements in the allergic mucin. Squash cytology of the paranasal sinus contents was especially useful for proving the presence of fungi.
    Medical Mycology 10/2007; 45(6):559-64. · 1.98 Impact Factor
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    ABSTRACT: We describe a case of giant cervical internal carotid aneurysm successfully treated by endovascular trapping. A 57-year-old woman with a history of maxillary contusion seven years before presented with pharyngeal discomfort during swallowing. MRI revealed a 4 cm mass in the right parapharyngeal space. A common carotid angiogram revealed a giant aneurysm with a wide neck originating from the cervical internal carotid artery; kinking of the internal carotid artery was noted at a point distal to the carotid bifurcation. Analysis of cerebral blood flow by SPECT during a balloon occlusion test showed no hypoperfusion areas, and the patient underwent endovascular trapping. There were no neurological or other complications after the procedure. A follow-up MRI revealed complete thrombosis of the aneurysm. Our results show that endovascular trapping for pseudoaneurysm of the cervical internal carotid artery can be a reliable and effective treatment in patients who tolerate a balloon occlusion test.
    Interventional Neuroradiology 09/2007; 13(3):281-5. · 0.77 Impact Factor
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    ABSTRACT: The brain is frequently affected by the spread of lung cancer, and haematogenous metastasis is a common route to brain metastasis. We therefore developed an isogenic brain metastasis model of lung cancer to use the Lewis lung carcinoma cell line and analysed dynamics of neoplastic cells after extravasation. Histological analysis revealed two characteristic patterns: metastatic foci exhibiting an angiocentric pattern were designated 'perivascular proliferations'; neoplastic cells infiltrating the brain parenchyma were designated 'invasive proliferations'. Electron microscopic observation of perivascular proliferations showed that neoplastic cells were confined to the perivascular space. In invasive proliferations, however, fragments of collagen fibre were observed in the gaps between neoplastic cells, indicating that the neoplastic cells had disintegrated the pia-glial membrane. We analysed the expressions of matrix metalloproteinase-2 (MMP-2) and MMP-9 by using both immunohistochemical analysis and real-time polymerase chain reaction analysis. MMP-2 expression was significantly higher in invasive proliferations. MMP-9 expression was significantly higher in day 7, but there was no significant difference in day 11. The pia-glial membrane and perivascular space are the barriers that neoplastic cells must overcome to infiltrate the brain. In conclusion, our findings suggest that brain metastasis requires two distinct processes.
    Neuropathology and Applied Neurobiology 07/2007; 33(3):288-98. · 4.84 Impact Factor
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    ABSTRACT: The cerebral circulatory dynamics were evaluated before and after intra-arterial administration of fasudil hydrochloride in 20 patients with angiographic vasospasm after subarachnoid hemorrhage (SAH). The region of interest time-density curves obtained before and after intra-arterial administration of fasudil hydrochloride were compared in the proximal portion of the middle cerebral artery in the early arterial phase, the distal portion of the middle cerebral artery in the late arterial phase, and the transverse sinus in the venous phase. In the early arterial phase, the time to peak and the time to half-peak were significantly reduced. In the late arterial phase and venous phase, the time to peak was significantly reduced. These results suggest that intra-arterial administration of fasudil hydrochloride induced dilation of the proximal arteries, and improved cerebral microcirculation. The present study suggests that intra-arterial administration of fasudil hydrochloride is effective as a treatment for vasospasm following SAH.
    Neurologia medico-chirurgica 12/2006; 46(11):535-9; discussion 540. · 0.49 Impact Factor
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    ABSTRACT: We report a case of encapsulated intracranial hematoma (EIH) mimicking metastatic brain tumor. A 77-year-old male with a medical history of prostate cancer was admitted to our hospital presenting with progressive left hemiparesis. Previous head CT scan and MRI findings during 3 weeks before admission revealed a subcortical acute to subacute hematoma under the right precentral gyrus with growing perifocal brainedema. The Head DSA showed tumor-stain with vascular compression corresponding to the hemorrhagic mass, and Tl-201 SPECT study revealed high L/N ratio (3.0) and high L/E ratio (0.8). The preoperative diagnosis was metastatic brain tumor originating from prostate cancer, and total removal of the mass was undergone with the postoperative diagnosis of EIH. Neither tumoral component nor vascular malformation was found even by detailed pathological study. EIH is a rare variant of intracranial hemorrhage and most of cases in past reports are preoperatively misdiagnosed as malignant brain tumor. In our case, even Tl-201 SPECT and DSA, which are reported as key studies for distinguishing EIH from other brain tumors, demonstrated brain tumor-like findings. It is necessary to consider the possibility of EIH when we encounter hemorrhagic mass in the brain parenchyma even with brain tumor-like radiographical images.
    No shinkei geka. Neurological surgery 09/2006; 34(8):851-6. · 0.13 Impact Factor
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    ABSTRACT: The purpose of this study was to develop a new technique for diffusion-weighted MRI (DWI) with a low-field scanner. DWI is becoming important for assessment of acute stroke. Until recently DWI required expensive technology. We developed multishot-DWI sequence for 0.3T open type MR imager. We prospectively studied forty patients on this 0.3T MRI and compared this DWI to single-shot-DWI by 1.5T-MRI. Group A: Twenty-four patients with acute cerebral infarctions detected by 1.5T-DWI were re-examined using 0.3T-DWI within 24 hours. Sixteen patients with acute cerebral infarctions detected by 0.3T-DWI were re-examined using 1.5T-DWI within 24 hours. In 22 (92%) of 24 cases, 0.3T-DWI showed high signal. In the other two patients, motion artifact distorted 0.3T-DWI. Group B: In all 16 patients, all infarctions detected by 0.3T-DWI showed high signal on 1.5T-DWI. These preliminary data show that, as long as the patient is able to keep still, multishot-DWI can be acquired successfully on a 0.3T open type MRI system.
    Journal of Neuroradiology 03/2006; 33(1):57-61. · 1.24 Impact Factor
  • Neurologia Medico-chirurgica - NEUROL MED-CHIR. 01/2006; 46(11):535-540.
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    ABSTRACT: We assessed the accuracy of voxel-based morphometry (VBM) using a three-dimensional T1-weighted MRI in discriminating Alzheimer's disease (AD) in the very early stage of amnestic type of mild cognitive impairment and age-matched healthy controls. We randomly divided these subjects into two groups. The first group comprising 30 AD patients and 41 controls was used to identify the area with the most significant gray matter loss in patients compared to normal controls based on the voxel-based analysis of a group comparison. The second group comprising 31 patients and 41 controls was used to determine the discrimination accuracy of VBM. A Z-score map for a gray matter image of a subject was obtained by comparison with mean and standard deviation gray matter images of the controls for each voxel after anatomical standardization and voxel normalization to global mean using the following equation; Z-score=([control mean]-[individual value])/(control S.D.). Receiver operating characteristic curves for a Z-score in the bilateral medial temporal areas including the entorhinal cortex with the most significant loss in the first group showed a high discrimination accuracy of 87.8%. This result would open up a possibility for early diagnosis of AD using VBM.
    Neuroscience Letters 08/2005; 382(3):269-74. · 2.03 Impact Factor
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    ABSTRACT: Proximal occlusion of the vertebral artery is regarded as a safe and effective method of treating aneurysms of the vertebral artery or the vertebrobasilar junction unsuitable for treatment by neck clipping. Complications known to develop after this procedure include ischemic lesions of the perforators and other areas. There are only a limited number of reports on early rupture of aneurysm following proximal occlusion of the vertebral artery for the treatment of unruptured aneurysm. We recently encountered a case of large aneurysm of the vertebral artery identified after detection of brainstem compression. This patient underwent proximal occlusion of the vertebral artery with a coil and developed a fatal rupture of the aneurysm ten days after proximal occlusion. The patient was a 72-year-old woman who had complained of dysphagia and unsteadiness for several years. An approximately 20 mm diameter aneurysm was detected in her left vertebral artery. She underwent endovascular treatment, that is, her left vertebral artery was occluded with coils at a point proximal to the aneurysm. Her initial post-procedure course was uneventful. However, she suddenly developed right-side hemiparesis nine days after procedure. At that time, CT scan suggested sudden thrombosis of the aneurysm. Right vertebral angiography revealed a small part of the aneurysm. She was treated conservatively. Ten days after the procedure, she suffered massive subarachnoid haemorrhage. Both the present case and past reports suggest that proximal occlusion of the vertebral artery is effective in treating relatively large aneurysms unsuitable for treatment by neck clipping or trapping. However, when the bifurcation of the posterior inferior cerebellar artery (PICA) is distal to the occluded point in cases where the PICA bifurcates from the aneurysm or the neck region, blood supply to the aneurysm may persist because anterograde blood flow to the PICA may be preserved. Therefore, clinicians must consider the possibility of aneurysm rupture after proximal occlusion in the following cases: 1) when the aneurysm is large or giant, but non-thrombosed; 2) when thrombosis occurs soon after the procedure; 3) when postoperative angiography shows partial filling of the aneurysm with contrast agent through the contralateral vertebral artery of basilar artery or the cervical muscle branches.
    Interventional Neuroradiology 03/2005; 11(1):51-8. · 0.77 Impact Factor
  • Surgery for Cerebral Stroke 01/2005; 33(1):45-49.

Publication Stats

181 Citations
22.18 Total Impact Points

Institutions

  • 2011
    • National Cancer Center
      • Division of Metastasis and Invasion SIgnaling
      Tokyo, Tokyo-to, Japan
  • 2005–2011
    • Toho University
      • Department of Neurosurgery
      Edo, Tōkyō, Japan
    • National Center of Neurology and Psychiatry
      • Department of Radiology
      Кодаиры, Tōkyō, Japan