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Biomedical subjects

K Tabuchi

Publications and source records attributed to K Tabuchi.

At least 127 records · Page 7Linked to original sources

[Studies on motile-Aeromonas infection 3). Phage typing of motile Aeromonas isolated from patients with diarrhea].

Phage types were determined for 102 strains of motile Aeromonas isolated from patients with diarrhea at four metropolitan hospitals in Tokyo. The following results were obtained. 1) Of the 102 strains examined, 52 (51.0%) were divided into 28 phage types. This rate was considerably higher, compared to our previous results, namely, 21.7% for strains isolated from natural environments and 25% for those isolated from meats. By bacterial species, phage types could be determined for 33 (52.4%) of 63 strains of A. hydrophila, for 16 (45.7%) of 35 strains of A. sobria, 2 (50.0%) of 4 strains of A. caviae and 1 (100%) strain of Aeromonas spp. 2) Of the 52 strains for which the phage types could be determined, the greatest number (16 strains, 30.8%) were identified as belonging to Type I group. These are followed by 5 strains (9.6%) which were identified as Type I/III group and 2 strains (3.4%) each identified as Type I/II, I/II/V, IV, V and VI groups. The remaining 21 strains were identified as belonging to one of the other phage type groups. Thirty-five (67.3%) of the strains for which the phage types were identified, were found to belong either to Type I group or to combinations with Type I. This demonstrated that 34.0% of the isolates from patients with diarrhea were related to Type I.

Aeromonas↗

Chromosome-sized DNA of Malassezia pachydermatis by pulsed-field gel electrophoresis.

The genome of Malassezia pachydermatis isolates from dogs was resolved into six chromosomes by using pulsed-field gel electrophoresis and their molecular sizes were calculated as 820, 1,100, 1,400, 1,470, 1,660 and 1,820 Kb, respectively. Comparison of electrophoretic patterns suggested that the chromosomes of M. pachydermatis were homozygous.

Chromosomes, Fungal↗

Intracavernous epidermoid tumor presenting with abducens nerve paresis--case report.

An unusual case of a pediatric epidermoid tumor entirely located in the cavernous sinus is reported. A 6-year-old boy presented with left abducens nerve paresis which developed over 2 months. Neuroimaging demonstrated a lesion in the left cavernous sinus. Part of the tumor capsule and the pearly contents were removed by the left pterional approach through Dolenc's anterolateral triangle. No bleeding from the cavernous sinus occurred. The tumor was histologically identified as an epidermoid tumor. Postoperatively, the abducens nerve paresis improved. The presence of dural reflection in the lateral wall of the cavernous sinus and displacement of the intracavernous internal carotid artery are useful indicators for intracavernous lesions.

Abducens Nerve↗

Altered structure and expression of the p53 gene in human neuroepithelial tumors.

The p53 gene, located on chromosome 17p13.1, may be important in the pathogenesis of human neuroepithelial tumors, because it is a tumor suppressor gene and genetic alteration is essential for certain human cells to acquire the neoplastic phenotype. The structure and expression of the p53 gene were investigated in cultured human glioma cells and biopsied specimens of neuroepithelial tumors. Immunocytochemical examination of p53 gene expression revealed positive nuclear staining in six of seven glioma cell lines tested. Sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis demonstrated unequivocal heterogeneity of migration rate in p53 bands. Pulse-chase analysis clearly showed an increased half-life of p53 in cultured human glioma cells. These abnormalities are presumably due to genetic alterations in the p53 gene. Nucleotide substitutions in exon 5, 7, or 8 of the p53 gene could be detected by polymerase chain reaction-single strand conformational polymorphic analysis in four of seven (57%) human glioma cell lines, and nine of 29 (31%) biopsied specimens of neuroepithelial tumors examined. The present results indicate that genetic alterations in the p53 gene are responsible for the tumorigenesis of at least some human neuroepithelial tumors.

Astrocytoma↗

Suppression of anchorage-independent growth of human glioblastoma cell by major histocompatibility complex class I gene-transfection.

The host's immune system discriminates tumor cells from normal cells by recognizing the major histocompatibility complex (MHC) class I antigen expressed on the tumor cell membrane. However, the role of MHC class I antigen in tumor cells has not yet been clarified. In this study, the influence of MHC class I antigen expression on the tumorigenicity of a human glioblastoma cell line (KMG4) is examined. Barely detectable levels of MHC class I messenger ribonucleic acid were found to express in KMG4 cells by Northern blot analysis using mouse MHC class I (H-2Ld) and human leukocyte antigen (HLA)-B7 genes as probes. The H-2Ld gene connected at the downstream end of murine mammary tumor virus (MMTV)-promoter was cotransfected with the neomycine-resistant gene pSV2-neo into KMG4 cells, and the drug-resistant cells were selected. The KMG4 cells (KMG4-MMTV-Ld), which acquired the MHC class I gene were detected by Northern blot analysis with H-2Ld as the probe, and by immunohistochemistry using the H-2Ld-specific monoclonal antibody. Tumorigenicity, as determined by colony-forming ability in soft agar, was then compared between MHC class I-expressing KMG4-MMTV-Ld and nonexpressing control cells. The MHC class I-expressing cells were found to be deprived of colony-forming ability, indicating that MHC class I antigen could negatively influence the anchorage-independent cell growth of the human glioblastoma cell line KMG4.

Animals↗

[Traumatic bilateral oculomotor nerve palsy: a case report].

A 28-year-old woman, with no past medical history, was admitted soon after a motor vehicle accident on March 1, 1990. On admission there were multiple small wounds in the right temporal region, but no wounds around the orbits. She was semicomatose with bilaterally fixed dilated pupils (6mm) and ptosis. The eyes were abducted bilaterally. No other cranial nerve palsy was noted. She moved four limbs spontaneously. No skull fracture was present on X-ray films. Cervical X-ray films revealed straightened cervical vertebral column but no fracture. Pelvic bone X-ray films demonstrated fracture and diastasis of the pubic bone. A computed tomography scan demonstrated a small subdural or subarachnoid hemorrhage in the right ambient cistern. A magnetic resonance imaging (MRI) carried out 12 days after trauma demonstrated bilateral small subdural hematomas under the cerebellar tentorium and contusional lesions of the bilateral medial temporal lobes. There were no abnormalities present in the brain stem. The patient was treated conservatively with diuretics and steroids. Disturbance of consciousness gradually improved until one month after the trauma, when she came close to being alert. Bilateral ptosis cleared after 3 months, and adduction of the eyes recovered after 6 months. Vertical eye movement improved a little in 6 months. Fixed 6mm pupils changed to fixed 4mm pupils in 6 months. Bilateral traumatic oculomotor palsy is a rarely described condition, and its mechanism remains conjectural. We discussed the mechanism of the injury and the site of the lesion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Suppression of murine leukemia virus-mediated 3Y1 cell fusion by expression of mouse MHC class I.

Rat 3Y1 fibroblasts transformed by adenovirus type 12 or its E1A gene formed syncytia by cocultivation with Friend murine leukemia virus (MuLV)-producing cells. On the other hand, parental 3Y1 cells and those derivatives induced by other tumor viruses or chemical carcinogen showed no MuLV-mediated syncytium formation [N. Momozaki et al. (1990) Arch. Virol. 115: 123-126]. The expression of major histocompatibility complex (MHC) class I mRNA and antigens was significantly reduced in these Ad12- and E1A-transformed 3Y1 cells. In contrast, other tumor virus-and chemical carcinogen-transformed 3Y1 cells expressed MHC class I almost in normal levels as did parental 3Y1 cells. Furthermore, Ad12-transformed 3Y1 cells which started to express the transfected exogenous MHC class I gene, H-2Ld, showed no more MuLV-mediated 3Y1 cell fusion. These results indicate that the expression of MHC class I on the cell membrane is closely related to the inhibition of 3Y1 cell fusion by MuLV.

Actins↗

A possible clinical application of multicytokine-producing cytotoxic mononuclear cell (MCCM) therapy.

When peripheral blood mononuclear cells (PBMC) were incubated with a streptococcal preparation, OK-432, for 24 h, PBMC acquired cytolytic activity against cultured and fresh human tumor cells. Such PBMC were called OK-432-activated mononuclear cells (OK-MC). OK-MC produce several kinds of cytokines such as interferon alpha (IFN alpha), IFN gamma, and tumor growth inhibitory factor (TGIF) both in vitro and in vivo. OK-MC-produced cytokines also inhibited the growth of cultured and fresh human tumor cells. The growth inhibition was examined by human tumor clonogenic assay using a double-layer agar technique. The results indicate that two pathways of anti-tumor activity are induced in OK-MC, i.e., cell-mediated and cytokine-mediated.

Adenocarcinoma↗

Pain-related somatosensory evoked potentials in syringomyelia.

Pain-related somatosensory evoked potentials following CO2 laser stimulation (pain SEPs) and conventional electrically-stimulated SEPs (electric SEPs) were examined in 8 patients with syringomyelia who showed various forms of dissociated sensory loss. Unlike clinical examination using a pin or needle, pain SEP is considered to be an objective and quantitative test to investigate functions of peripheral and central sensory pathways responsible for pain-temperature sensation (A delta fibres and the spinothalamic tract). Pain SEPs were abnormal in all patients. The results were generally compatible with the degree of a clinical impairment of pain-temperature sensation. Subclinical abnormality was detected in 3 patients. Electric median nerve SEPs using the scalp reference (Fz) were normal in 6 out of 8 patients. However, anterior and posterior cervical responses using a noncephalic reference were absent or small in 7 patients. Electric SEPs following tibial nerve stimulation were normal in 7 patients. These findings suggest that the function of the ascending fibres through the dorsal columns is intact in most patients, whereas the dorsal horn, where a fixed cervical potential is generated, is impaired. Pain SEPs combined with electric SEPs therefore appear to be extremely useful for investigating physiological function in the sensory pathways in patients who show 'dissociated sensory loss' such as in syringomyelia.

Adult↗

[Studies on motile-Aeromonas infection: 2). Development of a bacteriophage typing system for motile Aeromonas].

We succeeded in isolating Aeromonas-susceptible phages from river water and mud after a few years (1983-1985) of painstaking effort. For the first time in Japan, we investigated phagetypes of the bacterial strains isolated. The results obtained are summarized as follows: 1) Aeromonas-susceptible phages were isolated from 82 (40.1%) of 195 samples of river water and from 23 (25.6%) of 90 samples of river mud. By the cross-matching test of the phages isolated from the 105 samples, these were classified into 13 type groups (Groups I-XIII). 2) When 594 Aeromonas strains isolated from river water, lake water, river mud and fresh-water fish were examined using the phage group patterns developed by us, 129 (21.7%) strains classified into these phagetypes. Phagetyping was possible for 11 (15.5%) of the 71 strains isolated from river and lake water, for 29 (35.4%) of the 82 strains from river mud and for 89 (20.2%) of the 441 strains from fresh-water fish. By bacterial species, phagetyping was possible for 53 (51.5%) of the 103 strains of A. hydrophila. 21 (7.2%) of the 292 strains of A. sobria, 13 (8.8%) of the 148 strains of A. caviae and 42 (82.4%) of the 51 strains of Aeromonas spp.. Especially the phages classified as Groups I, IV and VI amounted to the majority. Thus we succeeded in isolating Aeromonas-susceptible phages which could be classified into Groups I-XIII. The results suggested the possibility of utilizing this phagetyping for analysis of the ecological distribution of genus Aeromonas.

Aeromonas↗

Neuroepithelial cyst presenting as recurrent aseptic meningitis.

A 41-year-old man had three episodes of acute aseptic meningitis from the age of thirty-six. With each episode he had severe occipital headache associated with a mononuclear pleocytosis and an increase in CSF protein. He had a neuroepithelial cyst originating from the choroid plexus of the right cerebellomedullary cistern. Spontaneous ruptures of the cyst probably caused recurrent chemical meningitis. A neuroepithelial cyst must be considered in the differential diagnosis of intracranial cystic tumors presenting with aseptic meningitis.

Adult↗

Dural arteriovenous malformation associated with occlusion of the superior sagittal sinus--case report.

The authors report a rare case of dural arteriovenous malformation (AVM) associated with occlusion of the superior sagittal sinus. A 78-year-old female developed transient aphasia, followed by generalized convulsion. Common carotid angiography showed a dural AVM fed by the bilateral middle meningeal arteries, draining to the superior sagittal sinus, and sinus occlusion. 123I-single photon emission computed tomography demonstrated decreased blood flow in the bifrontal-parasagittal regions. Transcatheter embolization via the feeding arteries improved the cerebral blood flow around the lesion, and the symptoms disappeared.

Aged↗

Influence of extracellular matrix on the proliferation and differentiation of glioma cells in culture.

The influence of extracellular matrix on the proliferation and differentiation of glioma cells in vitro was investigated by culturing glioma cells in collagen gel and on collagen and laminin films. Rat C-6 glioma cells extended thin cytoplasmic processes, proliferated, and differentiated in collagen gel and on collagen film. The cells were stellate with multiple thin processes like the astrocyte in vivo. The intracellular content of cyclic adenosine-monophosphate in rat C-6 glioma cells on collagen film increased approximately four fold over the control level. In laminin film culture, rat C-6 glioma cells extended thin cytoplasmic processes with many knotty structures and proliferated. These findings confirm that extracellular matrix induces the differentiation of glioma cells.

Animals↗

[Traumatic sinus pericranii. Case report].

The patient was involved in a traffic accident at the age of 1 and the left parieto-occipital scalp was contused without skull fracture. At the age of 5, an extracranial scalp mass was first noticed just beneath the multiple scalp scars. Angiography through the mass revealed that the extracranial mass cavity was connected to the superior sagittal sinus through the emissary veins. The mass located in the subgaleal, epiperiosteal space was totally resected and the connection with the intracranial sinus was closed with bone wax. Histologically, there were many capillaries and some large blood cavities with only one layered endothelium and connective tissue. Therefore, the mass was diagnosed as sinus pericranii and considered to be secondary to previous head trauma because: 1) The patient had a history of head trauma with considerably severe scalp injuries. 2) The extracranial blood sinus was located exactly beneath the traumatic scar. 3) There was no neoplastic tissue histologically. 4) No scalp mass was noticed before the traffic accident. 5) There was an elapsed time between the trauma and the growth of the mass. 6) No scalp nevus such as port-wine stain existed.

Child↗

[Bilateral fenestrations of the vertebrobasilar artery with trigeminal neuralgia. Case report].

Fenestration of cerebral vessels is congenital and usually of no clinical significance. A 58-year-old female presented with left trigeminal neuralgia associated with double fenestrations of the vertebrobasilar artery. Vertebral angiography showed bilateral fenestrations in the intracranial segment. The left fenestrated artery originated at the distal portion of the vertebral artery and terminated at the middle portion of the basilar artery, compressing the left Vth cranial nerve root. The neuralgia improved after microvascular decompression. Fenestration of cerebral vessels is usually single. Five of eight reported cases with double fenestrations had bilateral extracranial fenestrations at the atlantoaxial portion of the vertebral artery. Bilateral fenestrations of the vertebrobasilar artery with trigeminal neuralgia have not been previously reported.

Basilar Artery↗