Biomedical subjects

Toshiaki Abe

Publications and source records attributed to Toshiaki Abe.

At least 19 recordsLinked to original sources

PubMed2007

[Acute subdural hematoma associated with diffuse brain injury: analysis of 526 cases in Japan neurotrauma data bank].

OBJECTIVE: Traumatic acute subdural hematomas (ASDH) in Japan Neurotrauma Data Bank were categorized into focal brain injury (FBI) group and diffuse brain injury (DBI) group, and were analyzed to clarify the pathophysiological and therapeutic aspects of these injuries. METHODS: Data in Japan Neurotrauma Data Bank were reviewed for 1,002 severely head-injured patients treated at hospitals between 1998 and 2001; 526 of these patients had ASDH. ASDH in this data bank were categorized into FBI group and DBI group on the findings of CT scan. The clinical variables in these injuries were evaluated. RESULTS: Of 526 patients with ASDH, 246 (46.8%) were categorized into FBI group, 280, (53.2%) were DBI group. The patients with DBI group were younger, injured in traffic accident, lower Glasgow Coma Scale (GCS), higher Injury Severity Score, poorer outcome, compared to those with FBI group. The patients in DBI group, who underwent decompressive craniectomy and craniotomy, had a significantly better outcome than those who underwent hematoma evacuation via burr hole. There were no relationship between the time from injury to operation and outcome in the patients with DBI group, whereas patients with early surgery in FBI group showed significantly poorer outcome. Hypothermia and the placement of intracranial pressure monitor improved outcome only in patients of DBI group. CONCLUSION: It seems that the pathophysiological and therapeutic aspects of ASDH associated with DBI might differ from that with FBI alone.

Adult↗

PubMed2007

[A case of infected subdural hematoma].

A 87-year old male was admitted to our hospital due to generalized convulsion with loss of consiousness. He was afebrile and his blood sampling was not infectious. Computed tomography scan suspected left chronic subdural hematoma. Burr hole drainage was performed to remove the hematoma, but the abscess was aspirated in the subdural space. Infected subdural hematoma is rare. We discuss the clinical presentation, diagnosis and. treatment, and also briefly review the literature.

Aged, 80 and over↗

PubMed2006

Polymorphisms in Complement Factor H and Hemicentin-1 genes in a Japanese population with dry-type age-related macular degeneration.

PURPOSE: To determine whether polymorphisms in the Complement Factor H (CFH) gene and the Hemicentin-1 gene at the ARMD1 locus are associated with dry age-related macular degeneration (AMD) in Japanese patients. DESIGN: Clinically relevant laboratory investigation. METHODS: Eighty unrelated Japanese patients with dry AMD and 196 Japanese control patients were studied. Two exons of the CFH gene and four exons of the Hemicentin-1 gene were amplified by polymerase chain reaction and sequenced directly. RESULTS: For the CFH gene, the frequency of the previously reported Tyr402His variant was not significantly higher in the AMD group than in the control group (P = .31). In the Hemicentin-1 gene, three sequence alterations (Asp5088Val, IVS99-13C/T, and His5245Gln) were detected, and the originally reported Gln5346Arg was not detected. CONCLUSION: The CFH gene and Hemicentin-1 genes do not appear to be involved in a statistically significant fraction of dry AMD cases in the Japanese population.

Aged↗

PubMed2006

A case of Fukuyama-type congenital muscular dystrophy with a very mild mental deficit.

A boy had the clinical features of congenital muscular dystrophy with a very mild mental deficit. A muscle biopsy at one year of age showed the typical findings of Fukuyama-type congenital muscular dystrophy, including selective loss of immunoreactions for alpha dystroglycan. Magnetic resonance imaging showed no findings suggestive of migration disorders. The diagnosis of Fukuyama-type congenital muscular dystrophy was confirmed by a molecular assay at 8 years of age, and his haplotype analysis was heterozygous. At 9 years of age, his FIQ on the Wechsler Scale for Children revealed 69, while his IQ on the Tanaka Binnet scale of intelligence was 97. In this report the relationship between mild clinical condition of the studied case and its genotype is discussed.

Biopsy↗

PubMed2006

Identification and functional characterization of mouse TPO1 as a myelin membrane protein.

TPO1 is a member of the AIGP family, a unique group of proteins that contains 11 putative transmembrane domains. Expression of the rat TPO1 gene is upregulated in cultured oligodendrocytes (OLs) during development from pro-oligodendroblasts to postmitotic OLs. However, the distribution of native TPO1 protein in cultured OLs and in the brain has not been elucidated. We investigated the distribution and cellular function of TPO1 in myelinating cells of the nervous system. In mice, TPO1 gene expression was detected in the central (CNS) and peripheral (PNS) nervous systems and was markedly upregulated at postnatal days 10-20, an early phase of myelination in the mouse brain. To investigate TPO1 localization, we generated affinity-purified antibodies to synthetic peptides derived from mouse TPO1. Immunohistochemical analysis showed that TPO1 was expressed in OLs and Schwann cells but not in neurons and astrocytes. Schwann cells from trembler mice, which lack PNS myelin, had significantly decreased TPO1 expression and an altered localization pattern, suggesting that TPO1 is a functional myelin membrane protein. In OL lineage cell cultures, TPO1 was detected in A2B5+ bipolar early progenitors, A2B5+ multipolar Pro-OLs, GalC+ immature OLs and MBP+ mature OLs. The subcellular localization of TPO1 in OL lineage cells was mapped to the GM130+ Golgi in cell bodies and Fyn+ cell processes and myelin-like sheets. Furthermore, TPO1 selectively colocalized with non-phosphorylated Fyn and promoted Fyn autophosphorylation in COS7 cells, suggesting that TPO1 may play a role in myelin formation via Fyn kinase activation in the PNS and CNS.

Aging↗

PubMed2006

Ubiquitin C-terminal hydrolase L1 regulates the morphology of neural progenitor cells and modulates their differentiation.

Ubiquitin C-terminal hydrolase L1 (UCH-L1) is a component of the ubiquitin system, which has a fundamental role in regulating various biological activities. However, the functional role of the ubiquitin system in neurogenesis is not known. Here we show that UCH-L1 regulates the morphology of neural progenitor cells (NPCs) and mediates neurogenesis. UCH-L1 was expressed in cultured NPCs as well as in embryonic brain. Its expression pattern in the ventricular zone (VZ) changed between embryonic day (E) 14 and E16, which corresponds to the transition from neurogenesis to gliogenesis. At E14, UCH-L1 was highly expressed in the ventricular zone, where neurogenesis actively occurs; whereas its expression was prominent in the cortical plate at E16. UCH-L1 was very weakly detected in the VZ at E16, which corresponds to the start of gliogenesis. In cultured proliferating NPCs, UCH-L1 was co-expressed with nestin, a marker of undifferentiated cells. In differentiating cells, UCH-L1 was highly co-expressed with the early neuronal marker TuJ1. Furthermore, when UCH-L1 was induced in nestin-positive progenitor cells, the number and length of cellular processes of the progenitors decreased, suggesting that the progenitor cells were differentiating. In addition, NPCs derived from gad (UCH-L1-deficient) mice had longer processes compared with controls. The ability of UCH-L1 to regulate the morphology of nestin-positive progenitors was dependent on its binding affinity for ubiquitin but not on hydrolase activity; this result was also confirmed using gad-mouse-derived NPCs. These results suggest that UCH-L1 spatially mediates and enhances neurogenesis in the embryonic brain by regulating progenitor cell morphology.

Animals↗

PubMed2006

Novel drug delivery system using thermoreversible gelation polymer for malignant glioma.

Many approaches to local tumor treatment have been reported and their efficacy demonstrated in patients with malignant glioma. We studied thermoreversible gelation polymer (TGP) as a novel drug delivery system (DDS) for treating this type of tumor. TGP exhibits sol-gel transition i.e., is water-soluble in the sol phase below the chosen sol-gel transiting temperature and water-insoluble in the gel phase above this temperature. We conjugated doxorubicin with TGP to prepare doxorubicin-TGP (DXR-TGP), then studied the kinetics of doxorubicin release from TGP and the antitumor activity of DXR-TGP in vitro and in vivo. The diffusive speed of doxorubicin from TGP was 9.4x10(-7) cm(2)/s and doxorubicin was reliably released from TGP. DXR-TGP showed antitumor activity against the human glioma cell lines T98G and U87MG and in a subcutaneous tumor model in nude mice. Pathologically, detection of the proliferation marker Ki-67 was considerably lower in the DXR-TGP group than in the control group (30-40% vs. 60-70%, respectively). This is to the best of our knowledge the first report of TGP as a novel drug delivery system, and further we provide evidence that TGP exhibits potential for use as a novel DDS for malignant glioma.

Animals↗

PubMed2006

Hypothermia of 8 degrees C protects cultured retinal pigment epithelial cells and retinal ganglion cells against trypan blue toxicity.

PURPOSE: To determine whether hypothermia of 8 degrees C can protect cultured human retinal pigment epithelial (ARPE-19) cells and rat retinal ganglion cells (RGC-5) against trypan blue (TB) toxicity. DESIGN: Laboratory investigation. METHODS: ARPE-19 cells and RGC-5 were exposed to balanced salt solution as controls, and 0.05% and 0.5% TB at 37 degrees C, and at 8 degrees C for one minute. The percentage of surviving cells was determined by the resazurin test. RESULTS: TB induced a statistically significant decrease in the percentage of ARPE-19 cells surviving at 0.5% TB at 37 degrees C (P < .01). Conversely, TB induced a statistically significant decrease in the percentage of RGC-5 surviving at all conditions except for 0.05% TB at 8 degrees C (0.05% 37 degrees C; P < .05, 0.5% 37 degrees C and 8 degrees C; P < .01). CONCLUSIONS: These results indicate that reducing the temperature to 8 degrees C has a protective effect against the TB toxicity for ARPE-19 cells and RGC-5 in culture.

Animals↗

PubMed2006

Hypothermia protects cultured human retinal pigment epithelial cells against trypan blue toxicity.

PURPOSE: To determine whether trypan blue (TB) is toxic to cultured human retinal pigment epithelial (ARPE-19) cells, and whether hypothermia can protect ARPE-19 cells against TB toxicity. METHODS: ARPE-19 cells were cultured and exposed to balanced salt solution as a control, while other cells were exposed to 0.05, 0.2, and 0.5% TB dye at 37 and 4 degrees C for 5 and 30 min. The percentage of ARPE-19 cells that survived was determined by resazurin 1 day after the exposure. RESULTS: A statistically significant decrease in the percentage of ARPE-19 cells surviving was found after exposure to 0.2 and 0.5% TB at any temperature or for any exposure duration (p < 0.01). The percentage of RPE cells surviving at 0.05% was not significantly different from that of controls except for a 30-min exposure at 37 degrees C. The percentage of cells surviving at 4 degrees C for a 5-min exposure to 0.5% TB and a 30-min exposure to 0.2 and 0.5% was significantly higher than that at 37 degrees C under each condition (p < 0.01 for all). CONCLUSIONS: These results indicate that TB is toxic to human RPE cells, and the toxicity is dose- and exposure duration-dependent. Exposing the cells at 4 degrees C had a protective effect against higher concentrations or longer exposure durations of TB compared to exposure at 37 degrees C.

Cell Count↗

PubMed2006

Recombinant AAV-transduced iris pigment epithelial cell transplantation may transfer vector to native RPE but suppress systemic dissemination.

PURPOSE: To determine whether adenoassociated virus (AAV) vectors transduced into iris pigment epithelial (IPE) cells and transplanted into the subretinal space of rats will transfer the AAV genome to the host cells and whether the vectors are disseminated systemically. METHODS: Recombinant (r)AAV was transduced into rat IPE cells and transplanted into the subretinal space of rats. For the control, rAAVs alone were injected subretinally. The transplanted IPE cells were detected by LacZ staining. Immunohistochemistry, electron microscopy, electroretinography, and fluorescein-dextran angiography were performed. DNA was extracted from various organs and blood and examined for the AAV genome by polymerase chain reaction. RESULTS: No toxicity from rAAV transduction was observed in vitro. LacZ was expressed in the transplanted cells 1 and 2 weeks after transplantation. At 4 and 12 weeks, fewer transplanted cells were detected than at 1 week, and LacZ expression was occasionally detected at the level of host retinal pigment epithelial (RPE) cells. Expression was also detected in ciliary body epithelial cells. The electroretinograms and fluorescein-dextran angiography were only mildly altered. Significantly lower levels of AAV genome were detected in the organs and blood of rats receiving rAAV-IPE cell transplants than with direct intravenous injection of AAV vectors. CONCLUSIONS: AAV-mediated LacZ was expressed in the transplanted cells after subretinal transplantation, and the transplanted IPE cells may transfer the rAAV to host tissues, such as RPE cells, long after the transplantation. This method of gene delivery did not lead to systemic dissemination of the vectors.

Animals↗

PubMed2006

Perisacral gastrointestinal stromal tumor with intracranial metastasis. Case report.

A 68-year-old woman presented with an extremely rare intracranial metastasis from a gastrointestinal stromal tumor (GIST) manifesting as left hemiparesis 2 years after resection of a sacral tumor adjacent to the coccygeal bone. Magnetic resonance imaging revealed an intracranial tumor in the right parietal lobe. Craniotomy was performed to completely remove the tumor. Although the tumor was located extra-axially, only internal carotid angiography showed mass staining. Seven months after surgery, the tumor recurred. Repeat craniotomy was performed to remove the recurrent tumor. Immunohistochemical analysis showed that the tumor cells were positive for c-kit and CD34, and the tumors were identified as intracranial metastasis of GIST. Following the second intracranial surgery, the patient developed severe lower back pain caused by metastatic tumor invading the lumbar spine and ureter. To avoid surgical complications and to reduce tumor volume, imatinib mesylate (Gleevec) was administered. The severe pain was relieved, although the tumor was not reduced. In this case, the extra-axial tumor was fed only by the internal carotid artery.

Aged↗

PubMed2006

Endovascular operating suite: future directions for treating neurovascular disease.

OBJECT: The purpose of this study was to evaluate initial experiences in a surgical operating room (OR) with a multipurpose angiography unit, which offers integrated neurosurgical and radiological capabilities. METHODS: A specially designed biplane digital subtraction (DS) angiography system was installed in the neurosurgery OR. The new suite, which allows three-dimensional DS angiography with C-arm for computerized tomography and microsurgery capabilities, allows the neurosurgeon to perform a wide range of neurosurgical and endovascular procedures. Three hundred thirty-two procedures were performed in the endovascular OR between November 2003 and March 2005. Patients arriving in the emergency department were transferred to the endovascular OR without delay. The neurovascular team performed diagnostic angiography followed by endovascular interventional procedures or surgery. CONCLUSIONS: The newly designed endovascular OR facilitates safe and systemic treatment of neurovascular disease.

Aged↗

PubMed2006

[Endovascular treatment of large petrous internal carotid artery aneurysm associated with chronic otitis media: case report].

Aneurysms of the petrous internal carotid artery are rare, and surgical treatment of the aneurysm in the petrous bone carries high risk with procedure. We report a case of large petrous internal carotid artery aneurysm associated with otitis media. A 58-year-old female was admitted to our institution with left hearing loss and facial palsy. She had 4-year history of left exudative otitis media. Imaging studies demonstrated a 17 mm left petrous internal carotid artery aneurysm, destroying osseous partition between carotid canal and Eustachian tube, and protruding into left middle cranial fossa. Endosaccular coil embolization with balloon assist technique was performed successfully without neurological deficit. Follow up magnetic resonance angiogram demonstrated complete obliteration of the aneurysm without parent artery occlusion. Traumatic, mycotic, radiation, and congenital origin have been implicated for petrous internal carotid artery aneurysm. In a review of the literature, 11 cases of mycotic aneurysms in this location were reported and all of them were complicated with chronic otitis media. Because of its close proximity of middle ear and Eustachian tube, adventitial infection of the artery weakens the arterial wall, and gives rise to formation of aneurysm. We conclude that our case is of mycotic origin, and endosaccular coil embolization is effective and less invasive treatment.

Aneurysm↗

PubMed2006

[Intraoperative photodynamic diagnosis for spinal ependymoma using 5-aminolevulinic acid: technical note].

OBJECTIVE: The fluorescence-guided resection using 5-aminolevulinic acid (5-ALA) is a well established method for the treatment of brain tumor, especially malignant glioma. However, there is no report on photodynamic diagnosis (PDD) for spinal tumor. In the present study, we evaluated the usefulness of PDD for spinal ependymoma using 5-ALA. METHODS: Three patients with spinal ependymoma received oral doses of 5-ALA (20 mg/kg body weight) 2 hours before anesthesia induction. Intraoperatively, fluorescence was observed with a 420 nm sharp cut filter after excitation with a violet semiconductor laser (405 nm) and was verified by analysis of fluorescent spectra. Residual fluorescent samples taken from the tumor cavity were examined histologically RESULTS: Fluorescence peaked at 636nm in the removed tumors in all cases. Fluorescent tissue tended to exist at the cranial and caudal portion in the tumor cavity or around the anterior median fissure. The residual fluorescent tissue was not detected after removal of the tumor in case 1. The residual fluorescent tissue was composed of tumor cells and ependymal lining in case 2 or the infiltrated inflammatory cells and vascular endothelial cells in case 3. Postoperative magnetic resonance (MR) imaging showed no residual tumor in any of the cases. CONCLUSION: The results of this study indicate the usefulness of 5-ALA-induced tumor fluorescence in guiding resection of spinal ependymoma. 5-ALA-induced porphyrin fluorescence may label spinal ependymomas easily and clearly enough to enhance the completeness of tumor removal.

Adult↗

PubMed2005

Enantioselective total synthesis of (-)-candelalide A, a novel blocker of the voltage-gated potassium channel Kv1.3 for an immunosuppressive agent.

A convergent route to (-)-candelalide A involved the union of a trans-decalin portion (AB ring) and a gamma-pyrone moiety through the C16-C3' bond to assemble the whole carbon framework and subsequent formation of the dihydropyran ring (C ring) as the crucial steps. A strategic [2,3]-Wittig rearrangement was employed for establishing the stereogenic center at C9 and an exo-methylene function at C8 present in the decalin portion. [reaction: see text]

Ascomycota↗

PubMed2005

Overexpression of heat shock proteins in pallido-nigral axonal spheroids of nonhuman aged primates.

The occurrence of spheroids has been described in the globus pallidus (GP) and substantia nigra pars reticulata (SNr) of aged rhesus monkeys. Opinions vary as to the origin of spheroids. Ultrastructural and immunohistochemical analysis suggested that spheroids originate from degenerating axons or astroglia. In the present study, we have investigated the GP and SNr of aged monkeys (Macaca fascicularis and Macaca mulatta). Although immunoreactive for microtubule-associated protein (MAP) 1A, tau, amyloid precursor protein, synaptophysin and phosphorylated neurofilament, spheroids were not immunoreactive for MAP1B and MAP2. We confirmed the axonal nature of pallido-nigral spheroids in aged rhesus monkeys. Pallido-nigral spheroids have been reported to overexpress stress proteins, such as ubiquitin, alphaB-crystallin, and heat shock protein (Hsp) 27. We further evaluated the expression of Hsps in pallido-nigral spheroids. As well as being intensely immunoreactive for ubiquitin, alphaB-crystallin, Hsp27, and Hsp70, spheroids were immunoreactive for Hsp32 (heme oxygenase-1), Hsp40, Hsp60, and Hsp90. On the basis of these findings, we speculate that Hsp32-immunoreactive spheroids might be expressed as an oxidative stress response. Induction of other Hsps might play a role in protection of axons from the aggregation of neurofilament, MAPs and other proteins, and failure to protect degenerating axons might result in their proteolysis by the ubiquitin-proteasome system.

Age Factors↗

PubMed2005

Outbreak of acute gastroenteritis associated with group A rotavirus and genogroup I sapovirus among adults in a mental health care facility in Japan.

An outbreak of acute gastroenteritis consisting of 57 cases occurred in a mental health care facility in Takasaki city, Japan during 6th February and 27th March 2002. A total of 18 fecal specimens collected from 17 residents and one member of the medical staff during this outbreak were tested for the presence of viral enteropathogens by RT-PCR and latex agglutination. Group A rotavirus and sapovirus were detected in 5 out of 18 fecal specimens (55.6%). To our knowledge, this is the first finding of an outbreak of gastroenteritis associated with co-circulation of different kinds of viruses such as group A rotavirus and sapovirus. All of group A rotaviruses were typed further as P[4]G2 strains. Both rotavirus and sapovirus were subjected to molecular analysis by sequencing. It was noteworthy that all rotaviruses and sapoviruses had high homologies, respectively, to each other and sapoviruses presented a potential novel sapovirus genogroup I (GI) genotype, which was obviously different from any GI genotypes (GI-a, b, c, and d). The outbreak associated with these viruses spread gradually from dormitory to dormitory, suggesting a spread by person-to-person contact, although investigation on the route of transmission of the outbreak is lacking. The findings confirm the presence of group A rotavirus and sapovirus are important in acute gastroenteritis among adults in Japan.

Adult↗

PubMed2005

Chemokine profile in the cerebrospinal fluid and serum of Vogt-Koyanagi-Harada disease.

We analyzed the concentrations of four chemokines in the cerebrospinal fluid (CSF) and sera in Vogt-Koyanagi-Harada disease (VKH), an autoimmune uveomeningitis syndrome against melanocyte-associated proteins, with ELISA. CSF-CXCL10/IP-10 and CSF-CCL17/TARC were significantly elevated in VKH than in controls. In the majority of VKH cases and controls, CSF-CXCL10 was higher than serum-CXCL10, and CSF-CCL17 was lower than serum-CCL17. CCL11/Eotaxin was not different between groups. CSF-CCL2/MCP-1 was significantly lower in VKH than in control. The changes in VKH were essentially similar to those in multiple sclerosis, a known Th1-dominant condition.

Adolescent↗