Biomedical subjects

Naoko Fujimura

Publications and source records attributed to Naoko Fujimura.

9 recordsLinked to original sources

PubMed2006

Wnt-mediated down-regulation of Sp1 target genes by a transcriptional repressor Sp5.

Wnt/beta-catenin signaling regulates many processes during vertebrate development. To study transcriptional targets of canonical Wnt signaling, we used the conditional Cre/loxP system in mouse to ectopically activate beta-catenin during central nervous system development. We show that the activation of Wnt/beta-catenin signaling in the embryonic mouse telencephalon results in the up-regulation of Sp5 gene, which encodes a member of the Sp1 transcription factor family. A proximal promoter of Sp5 gene is highly evolutionarily conserved and contains five TCF/LEF binding sites that mediate direct regulation of Sp5 expression by canonical Wnt signaling. We provide evidence that Sp5 works as a transcriptional repressor and has three independent repressor domains, called R1, R2, and R3, respectively. Furthermore, we show that the repression activity of R1 domain is mediated through direct interaction with a transcriptional corepressor mSin3a. Finally, our data strongly suggest that Sp5 has the same DNA binding specificity as Sp1 and represses Sp1 target genes such as p21. We conclude that Sp5 transcription factor mediates the downstream responses to Wnt/beta-catenin signaling by directly repressing Sp1 target genes.

Amino Acid Sequence↗

PubMed2005

Insoluble fiber is a major constituent responsible for lowering the post-prandial blood glucose concentration in the pre-germinated brown rice.

The intake of pre-germinated brown rice (PR) instead of white rice (WR) ameliorates the hyperglycemia. To clarify the mechanism(s) to decrease the post-prandial blood glucose concentration, the effect of water-soluble/oil-soluble fraction-depleted PR bran (termed as "DB"; which is destarched and defatted PR bran) on post-prandial blood glucose was compared with that of full-fat PR bran (PB) or WR. The test diets, WR diet, PB diet and DB diet which are containing identical amount of available carbohydrate (1.5 g) were fed to Wistar strain rats. Post-prandial blood glucose concentration and incremental area under the curve (IAUC) for DB diet were lower than those for WR diet, and there was no difference between the DB diet and PB diet. Changes in plasma insulin concentration and the IAUC obtained also revealed the same tendency as those observed in blood glucose concentration. These results indicate that the blood glucose-lowering effect of PB diet may be derived from the properties of PB involving substantially higher content of dietary fiber than WR, and that the potential benefit of intake of PR instead of WR in the prevention of diabetic vascular complications.

Animals↗

PubMed2005

[Ischemia of the sternocleidomastoid muscle following occipital artery embolization for dural arteriovenous fistula].

We report a case of localized ischemia of the sternocleidomastoid muscle (SCM) occurring after occipital artery embolization of a dural arteriovenous fistula (dAVF). A 45-year-old man presented intracerebral hemorrhage from a dAVF at the left transverse-sigmoid sinus. The dAVF had a high flow fistula from the left occipital artery (OA). Endovascular therapy was carried out one month later. Transarterial embolization of the OA was carried out prior to the transvenous approach to decrease the shunt flow. During obliteration of the proximal portion of the OA with fiber platinum coils and polyvinyl alcohol particles, the patient reported severe neck pain. The fistula was successfully embolized after transvenous packing of the left sigmoid sinus with detachable coils. The neck pain persisted for one week and disappeared after conservative treatment. T2-MR imaging 3 days after the embolization showed a hyperintensity in the left SCM. This ischemic lesion was probably induced by occlusion of the muscular branch of the OA. We discuss this common but rarely reported complication of OA embolization.

Carotid Artery, External↗

PubMed2005

[Case of meningioma with extracranial extension through the internal jugular vein].

We report a case of posterior fossa meningioma extending into the cervical jugular vein, which was successfully resected. A 57-year old male with ataxia and mild hypogeusia was admitted to our hospital. MRI demonstrated a well-circumscribed large posterior fossa mass with extracranial extension through the internal jugular vein. Two-staged surgical treatment was then performed. The mass in the posterior fossa was removed at the first operation. The tumor was invading into the sigmoid sinus which was filled with tumor. The second operation for extracranial mass was performed 1 month later. Transcervically, the internal jugular vein obstructed by tumor was successfully removed. The post-operative course was uneventful and histopathological examination revealed the fibrous meningioma in the posterior fossa, but the intravenous portion of the tumor showed more atypical findings. Such a case is quite uncommon and the mechanism of tumor extension with different histological features is discussed.

Humans↗

PubMed2005

[Clinical study of multiple traumas with severe facial injury undergoing emergency endovascular treatment: significance of emergency embolization of the external carotid artery].

The outcome of multiple injures freqently depends on the priority of treatments, and the decision as to the procedures and timing of primary care is extremely important. We studied the patients with multiple trauma whounderwent emergency endovascular treatment for facial hemorrhage related to external carotid arterial injury. The subjects are 5 patients who underwent embolization of the external carotid artery by an endovascular approach among patients with multiple traumas who were brought to our hospital by ambulance. In these patients, the vital signs on arrival, interval between injury and intravascular surgery, type of brain injury, type and grade of concurrent injury and outcome were studied. Three patients showed hemorrhagic shock on arrival, and 1 patient showed hemorrhagic shock immediately after arrival. The mean interval between injury and endovascular surgery was 3.9 hours. All patients had skull base fracture, and abnormal intracranial lesions on initial CT including 4 focal injuries and 1 diffuse injury. Moderate to severe thoracic/abdominal injuries were noted in 3 patients. In the remaining 2 patients, there was no trauma in the thoracic or abdominal regions. Intraperitoneal hemorrhage with splenic injury was observed in 3 patients. In 3 of 4 patients died by hemorrhagic shock because of the delay of endvascular treatments. In trauma patients with persistent hemorrhage, emergency endovascular treatment should be considered as a primary survey for initial treatment without delay under intensive conservative treatment.

Accidents, Traffic↗

PubMed2003

Bilateral anomalous posterior inferior cerebellar artery-anterior inferior cerebellar artery anastomotic arteries associated with a ruptured cerebral aneurysm--case report.

A 50-year-old man presented with subarachnoid hemorrhage from a ruptured cerebral aneurysm arising from a left posterior inferior cerebellar artery (PICA)-anterior inferior cerebellar artery anastomotic artery manifesting as severe headache, obtundation, and quadriplegia. Conventional and three-dimensional digital subtraction angiography showed that the anastomotic complex was present bilaterally and both vertebral arteries terminated at the origin of the PICA. The identification of this anomalous vascular network allowed coil embolization of the broad-based aneurysm with occlusion of the parent artery. The patient had residual moderate disturbance of consciousness and quadriplegia before transfer for rehabilitation.

Aneurysm, Ruptured↗

PubMed2002

Primary intracerebral malignant fibrous histiocytoma in a child.

We report herein a rare case of pediatric intracerebral malignant fibrous histiocytoma (MFH). A 2-year-old boy gradually developed mild left hemiparesis and became somnolent. Magnetic resonance imaging upon admission revealed a well-enhanced mass lesion in the right frontotemporal operculum. Subtotal removal of the tumor was successfully performed using a right transsulcal and transcortical approach. The tumor developed as an extraaxial mass with brain adhesion to the arterial wall of the branch of the middle cerebral artery rather than to cerebral tissue. Pathological examination confirmed the presence of inflammatory-type MFH. Pediatric cases of intracerebral MFH are rare, and the possible origin of the tumor is discussed based on clinicopathological findings.

Brain Neoplasms↗

PubMed2002

Rapid multiplex single nucleotide polymorphism genotyping based on single base extension reactions and color-coded beads.

A single nucleotide polymorphism (SNP) typing method using color-coded beads is promising because it is easy to use and inexpensive. However, the present protocols are not suitable for clinical and diagnostic applications because they need centrifugation for bead-washing. Here, we developed a simplified protocol without a bead-washing procedure that enables SNP typing of PCR amplified fragments in only 30 min.

Journal Article↗

PubMedDate not supplied

Distal-tip shape-consistency testing of steam-shaped microcatheters suitable for cerebral aneurysm coil placement.

BACKGROUND AND PURPOSE: Although the selection of microcatheter for endovascular aneurysmal treatment is one important factor in patient outcome, the use of steam shaping for achieving safe entry and stability during coil placement has not, to our knowledge, been systematically evaluated. The goal of this study was to compare the durability of distal microcatheter steam shaping in five different catheters with typical intraprocedural stresses that are similar to those encountered during aneurysm coil placement. METHODS: Distal tips of microcatheters were shaped into a 90 degrees turn with distal straight-segment lengths of 3, 5, or 7 mm by using steam, performed according to the instructions for use included with each catheter. In a water bath kept at body temperature, the changes in catheter tip angle were recorded and measured following microcatheter insertion into a guiding catheter, microguidewire insertion through the microcatheter, and Guglielmi detachable coil (GDC) placement through the microcatheter. RESULTS: The degree of distal microcatheter straightening with typical intraprocedural manipulations was more pronounced on braided microcatheters and on microcatheters with 3- or 5-mm distal-shaped segments. The degree of spontaneous recovery of the initially steamed shape was more pronounced with nonbraided catheters. The most significant single variable contributing to straightening of a steam-shaped catheter tip was the effect of microguidewire insertion. The catheter-tip straightening effect encountered with inserting GDCs was less than that encountered with microguidewire insertion. We demonstrated that the decreased catheter-tip angle encountered with a large-magnitude straightening stress spontaneously recovered once the stress was removed or when it was reduced to a smaller magnitude stress. CONCLUSION: Our study shows that, although braided microcatheters are suitable for maintaining durable configurations when long distal-tip lengths are permissible, nonbraided microcatheters demonstrate the most durable distal-tip configurations when short distal-tip lengths are called for. This may be one of significant factors in catheter choice for endovascular treatment of aneurysm.

Catheterization↗