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Biomedical subjects

J Ito

Publications and source records attributed to J Ito.

At least 199 records · Page 11Linked to original sources
PubMed1993

[Recent advances in clinical application of event-related potentials].

Auditory and somatosensory ERPs were studied in patients with dementia of the Alzheimer type (DAT), those with vascular dementia and demented patients with idiopathic Parkinson disease. In both auditory and somatosensory modalities, the P3 latency in the demented patient group was significantly prolonged compared with the control data. However, comparisons of the P3 latency among the patients with DAT, vascular dementia and demented Parkinson did not reveal any significant differences. Patients with vascular dementia had significantly prolonged N140 and P200 latencies in somatosensory ERPs, whereas N1 and P2 latencies in auditory ERPs did not show any significant differences. Patients with acute onset hippocampal amnesia showed normal auditory P3 and somatosensory P3, whereas patients with diencephalic amnesia had prolonged auditory P3 and somatosensory P3 in addition to the abnormal short latency somatosensory evoked potentials. Analysis of passively evoked P3 component and comparison between target P3 and passively evoked P3 may be useful for evaluation of demented patients with a variety of etiologies. Single-trial analysis showed a greater variance of P3 latency in demented patients than in control subjects. A greater variance of P3 resulted in 'absent P3' in conventional averaging in some of the demented patients. As vigilance levels changed from trial to trial, evaluation of P3 latency variance has been proven to be useful.

Acoustic Stimulation↗
PubMed1993

[MRI findings of olivopontocerebellar atrophy and Machado-Joseph disease--diagnostic value of transverse pontine fibers].

Olivopontocerebellar atrophy (OPCA) and Machado-Hoseph disease (MJD) occasionally show similar clinical signs and symptoms, which makes differential diagnosis of OPCA and MJD difficult. In 1990, Savoiardo et al. reported that the transverse pontine fibers of OPCA patients had high signal intensity on T2 weighted MR images. To determine if the high signal intensity of the transverse pontine fibers is useful for the differential diagnosis of OPCA and MJD, we examined this abnormal intensity in patients diagnosed as OPCA or MJD. We observed the high intensity of transverse pontine fibers in all of the 18 OPCA patients. This finding, however, was not observed in any of the patients with the MJD. The high signal intensity of the transverse pontine fibers in T2 weighted images is characteristic of OPCA patients. Furthermore the atrophy of pontine tegmentum is characteristic of patients with MJD. These findings correlate well with pathological findings of OPCA and MJD, indicating the usefulness of these MRI findings for the differential diagnosis of OPCA and MJD.

Adult↗
PubMed1993

[A case of spontaneous spinal epidural hematoma].

A 14-month-old girl with spontaneous spinal epidural hematoma and complete postoperative recovery was described. MRI proved to be a sensitive tool in identifying the nature and extent of this lesion. A review of literature was made with particular emphasis on the pediatric age group.

Age Factors↗
PubMed1992

Primary non-Hodgkin malignant lymphoma of the breast. An immunohistochemical study of seven patients and literature review of 152 patients with breast lymphoma in Japan.

BACKGROUND: The breast is rarely a primary site for extranodal malignant lymphoma. Most reported primary non-Hodgkin malignant lymphomas of the breast (PBL) are of B-cell phenotype. METHODS: Histologic and immunohistochemical analyses of seven patients with PBL and a statistical analysis of 152 patients with PBL reported in the Japanese literature were performed. RESULTS: Malignant lymphoma could not be predicted preoperatively with clinical and radiologic findings; breast carcinoma, fibroadenoma, and phyllodes tumor were the preoperative diagnoses. All patients were women; they ranged in age from 31 to 80 years (mean, 57.6 years). The right breast was involved initially in five patients. In four, only the breast was involved (Stage I), whereas in three, the ipsilateral axillary lymph nodes (Stage II) were involved at diagnosis. According to the Working Formulation, all patients belonged to the intermediate grade and were classified as having diffuse large cell (five patients) or mixed (two patients) lymphoma. Immunophenotypic analysis revealed that all patients had B-cell lymphoma. No patients had lymphoepithelial lesions, which is the characteristic feature in categorizing a lymphoma as a mucosa-associated lymphoid tissue (MALT) lymphoma. A statistical analysis of the patient reported in the Japanese literature has divided PBL into two types: a bilateral type that affects younger women and a unilateral type that has a broad age distribution, but preponderantly occurs in older women. The age and stage at diagnosis were significant prognostic factors in predicting the survival time, but the location and size of the tumor at initial presentation, histopathologic type, terminal leukemic manifestation, and treatment modality were not. CONCLUSIONS: This study indicates that most PBL are diffuse large cell lymphoma of B-cell phenotype and that the age and stage at diagnosis are significant prognostic factors.

Adult↗
PubMed1992

Terminal deletion of the short arm of chromosome 3.

A boy with growth and mental retardation, flat occiput, high and broad forehead, blepharoptosis, narrow palpebral fissures, low set, malformed ears, short neck, anal atresia, deep sacral dimple is reported. High-resolution banding analysis showed terminal deletion of the short arm of chromosome 3 (46,XY,del(3)(p25.3)). Deletions of the short arm of chromosome 3 are relatively rare. The clinical features of the patient are compared with those of 19 previously reported cases.

Abnormalities, Multiple↗
PubMed1992

Interaction of sialosyl cholesterol with the cell surface of rat astrocytes and its biological activities.

The interaction between sialosyl cholesterol (alpha- or beta-D-N-acetyl neuraminyl cholesterol, alpha- or beta-SC) and the plasma membrane of astrocytes was investigated by the use of 14C-labeled alpha- or beta-SC. Both alpha- and beta-SC were dose-dependently and time-dependently bound to rat astrocytes. The Scatchard plot analyses showed that rat astrocytes bound apparently 9.69 x 10(9) molecules of both alpha-SC/cell (apparent Kd = 2.29 x 10(-5) M) and beta-SC/cell (apparent Kd = 5.39 x 10(-5) M) at 37 degrees C. Both the binding of alpha-SC to astrocytes and the subsequent inhibition of DNA synthesis were decreased at the low temperature (4 degrees C), and also suppressed by serum proteins including albumin. One molecule of bovine serum albumin (BSA) bound 2.3 molecules of alpha-SC with the slightly lower Kd-value (8.03 x 10(-6) M) than that for the binding site on astrocytes. BSA not only suppressed the alpha-SC-binding to astrocytes but also increased its release from the cells to the culture media. Gangliosides such as GM1 and GM3 unaffected the alpha-SC-binding, promoted the small release of alpha-SC from the cell surface, and inhibited the morphological changes of astrocytes induced by alpha-SC. The mechanism of alpha-SC-binding to cultured astrocytes with reference to the effects of serum or gangliosides is discussed.

Animals↗
PubMed1992

Identification of substances formed by decomposition of peak E substance in tryptophan.

Peak E substance, a trace impurity in L-tryptophan, has been associated epidemiologically with an outbreak of eosinophilia-myalgia syndrome (EMS) in the USA in 1989. After fractionation and purification of this substance, nuclear magnetic resonance and fast-atom-bombardment mass spectroscopy were used to identify the molecular structures of peak X/X' (formed by the decomposition of peak E substance in a simulated gastric fluid) and peak Y/Y' substances (which are believed to be the intermediates in the transformation of peak E substance to peak X/X' substances). The analyses were also performed on synthesized peak E substance obtained from the reaction of tryptophan with acetaldehyde. The results indicated that the synthesized substance was of high purity and was suitable for use in studies investigating the relationship between peak E substance and EMS onset.

Chromatography, High Pressure Liquid↗
PubMed1992

Hepatic accumulation and hepatotoxicity of luteoskyrin in mice.

HPLC analysis revealed that luteoskyrin administered orally to male mice accumulated selectively in the liver, with minor distribution to the serum and kidneys. Elevation of serum GOT and GPT values was maximal 3 days after administration. In mice administered this mycotoxin intravenously, selective accumulation was also observed in the liver, and the half-life of hepatic luteoskyrin in males was significantly longer than that in females. Increment of serum transaminases was also marked in males with maximum accumulation at 24 h after administration. Histopathologically, cellular membrane damage was an early effect of luteoskyrin on cell necrosis, and these morphological changes were also marked in males. Luteoskyrin also elevated hepatic lipid peroxides, the maximum elevation being 8 h after injection; this increase was suppressed by alpha-tocopherol and Bi(NO3)3. HPLC-ECD analysis indicated that the level of 8-hydroxy-deoxyguanosine, one of the markers of hydroxy-radical-mediated modification of DNA guanine residues, was increased in hepatic DNA. These findings indicate that luteoskyrin has a high affinity for the liver, resulting in induction of lipid peroxidation, hepatocellular membrane damage, and elevation of serum transaminase activities. It is suggested that the hydroxy radicals derived from this anthraquinone contribute to these toxicological changes.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1992

Antifungal prophylaxis during neutropenia or allogeneic bone marrow transplantation: what is the state of the art? Ad HOC Working Group.

Neutropenia induced by intensive chemotherapy and allogeneic bone marrow transplantation are increasingly commonly complicated by fungal infections; thus prophylaxis may be justified. The authors surveyed the literature and culled their experience - few randomized trials have been done and definitions have often been poor. In prophylaxis of mucosal candidosis, miconazole and clotrimazole may both be more effective than placebo. Nystatin is ineffective and ketoconazole of medicine efficacy. Fluconazole is effective at 50 mg/day and 400 mg/day. Itraconazole and amphotericin B both need further evaluation. In prevention of systemic candidosis, oral nystatin prophylaxis, up to 4 X 10(6) U/day, is usually unsuccessful, though compliance is variable. Oral amphotericin B in low doses is ineffective, but 50 mg or more 4 times daily may prevent systemic candidosis, though compliance is variable. Oral ketoconazole, 400-600 mg/day, is possibly effective prophylaxis in neutropenia but not after bone marrow transplantation; liver function (often abnormal in these patients) is a problem, as is tolerability. Oral fluconazole is well tolerated, has reliable serum concentrations and is effective following bone marrow transplantation, but the optimum dose is uncertain. In bone marrow transplantation, intravenous amphotericin B, 0.1 mg/kg/day, appears to be effective; there are no data in neutropenia. Oral itraconazole (capsules, 200 mg/day) may be active; data are scanty. In prevention of invasive aspergillosis, itraconazole, 200 mg/day, is probably active, but only if adequate serum concentrations are achieved. New oral and intravenous itraconazole formulations in cyclodextrin may achieve more reliable serum concentrations. No oral drug provides effective prophylaxis against Torulopsis, Fusarium, Trichosporon, or Pseudallescheria.

Antifungal Agents↗
PubMed1992

Thyroid storm associated with probable subclinical hypoadrenocorticism in an elderly woman.

A 73-year-old woman was admitted to the hospital for severe persistent vomiting with fever, drowsiness, and weight loss. Elevated serum levels of thyroid hormones and the presence of a consciousness disorder with fever and vomiting led to the diagnosis of thyroid storm. A low normal concentration of serum cortisol, urinary 17-hydroxycorticosteroids and an elevated plasma level of corticotropin suggest that an inadequate adrenal reserve have been involved in the pathogenesis of the thyroid storm in this patient. She responded to the administration of intravenous methimazole and oral supersaturated potassium iodide solution.

17-Hydroxycorticosteroids↗
PubMed1992

[A case report of postoperative recurrent hepatocellular carcinoma effectively treated with HCFU administration combined with TAE].

A 62-year-old man was found to have recurrent hepatocellular carcinoma (HCC) 2 cm in diameter in the left lobe in June 1990. After right lobectomy of the liver which contained the tumors of S6 2 cm and S8 3 cm in diameter 7 months before, the patient was treated with hepatic arterial embolization (TAE) combined with infusion of anti-cancer drug (ADM, CDDP) four times since June 1990. HCFU 300 mg per day was administered orally since June 1990. Since the 3rd TAE in December, 1990, the tumor stain in the left lobe disappeared for 10 months till October, 1991. No remarkable side effect of HCFU was noticed during this period. HCFU administration combined with TAE effectively prevented post-surgical recurrence of HCC in this case.

Antineoplastic Agents↗
PubMed1992

[Histopathological characteristics of rheumatoid arthritis--as a clue to elucidate its pathogenesis].

A correct histopathological diagnosis of Rheumatoid Arthritis (RA) is quite important for the decision of early phase treatment to cure it fundamentally. But, generally speaking, usual hospital pathologist is not so much experienced about RA. The purpose of this article is originally to let such pathologist familiar in RA pathology, but for the RA specialist to offer any clue to elucidate the still-unknown etio-pathogenesis of RA or to cure RA fundamentally. The "Tetralogy of RA Arthritis for pathologist" must be as follows: (1) Enormous proliferation of well-permeable granulation-tissue-type neo-vascularization, some of which became high column-endothelial and the center of primary as well as secondary follicle-like lymphoid cell cluster. (2) Lymphoid cluster in RA synovium is also pathological in function. It consisted of preferentially CD4T and B cells to produce IgG rheumatoid factor endlessly. (3) Synovial lining A and B cells proliferate as far as five layers of each, but later, the sublining D (M) and D (F) cells proliferate more and more and finally replace the lining cells. D (M) cells express macrophage marker and full of lysosome, on the contrary, D (F) cells express mesenchymal marker and contains much metalloproteinase. Both express strong Class II antigens but neither has complement activation inhibitor DAF. (4) Proliferation of these D cells with full of mesenchymal tissue destroying and inflammation accelerating activity must be playing a major role in the joint destruction of RA, some in shape of pannus and more in shape of granulation tissue in and around the bone.

Arthritis, Rheumatoid↗
PubMed1991

Initiation of bacteriophage PRD1 DNA replication on single-stranded templates.

In vitro studies have demonstrated that single-stranded DNA molecules containing the 3' terminal nucleotides of the PRD1 DNA replication origin can support initiation by a protein-primed mechanism. We have determined the minimal requirements for priming by analyzing the template activity of various deletion derivatives. Our results showed that the 3'-terminal 15 nucleotides of the replication origin are sufficient for priming. The finding that the requirements for recognition of replication origin are different from those for priming suggests that there are two distinct steps during initiation of PRD1 DNA replication: first, recognition of the replication origin on double-stranded DNA and second, the priming event on single-stranded DNA. In addition our results showed that additional bases at the 3' end of templates did not affect priming activity, suggesting that the priming site is searched for from inside the template.

Bacteriophages↗
PubMed1991

von Recklinghausen neurofibroma produces neuronal and glial growth-modulating factors.

Two kinds of novel neural trophic factors were currently detected in von Recklinghausen neurofibroma (NF1) extracts. One of the two was a growth factor, neuroblastoma growth factor (Mr less than 5 kDa), which promotes the proliferation of human neuroblastoma cell and survival and neurite-extension of rat cortical neurons, but differently from nerve growth factor (NGF) or NGF-like factors. The other one was a glial growth inhibitor (Mr = 100 kDa), which suppresses the growth of glioma cell lines, astrocytoma, glioblastoma, oligodendroglioma and Schwannoma. These factors do not appear to be previously identified cytokines or growth factors such as interleukins, granulocyte colony-stimulating factor, NGF and fibroblast growth factor. There was also detectable ciliary neurotrophic factor-like activity in the extracts. The primary cause of high contents of these factors in NF1 is not known, but may relate to fundamental mechanisms controlling growth and differentiation of neurons and glias during development of nervous system.

Animals↗
PubMed1991

Mapping of the DNA linking tyrosine residue of the PRD1 terminal protein.

DNA replication of PRD1, a lipid-containing phage, is initiated by a protein-priming mechanism. The terminal protein encoded by gene 8 acts as a protein primer in DNA synthesis by forming an initiation complex with the 5'-terminal nucleotide, dGMP. The linkage between the terminal protein and the 5' terminal nucleotide is a tyrosylphosphodiester bond. The PRD1 terminal protein contains 13 tyrosine residues in a total of 259 amino acids. By site-directed mutagenesis of cloned PRD1 gene 8, we replaced 12 of the 13 tyrosine residues in the terminal protein with phenylalanine and the other tyrosine residue with asparagine. Functional analysis of these mutant terminal proteins suggested that tyrosine-190 is the linking amino acid that forms a covalent bond with dGMP. Cyanogen bromide cleavage studies also implicated tyrosine-190 as the DNA-linking amino acid residue of the PRD1 terminal protein. Our results further show that tyrosine residues at both the amino-terminal and the carboxyl-terminal regions are important for the initiation complex forming activity. Predicted secondary structures for the regions around the DNA linking amino acid residues were compared in three terminal proteins (phi 29, adenovirus-2, and PRD1). While the linking amino acids serine-232 (phi 29) and serine-577 (adenovirus-2) are found in beta-turns in hydrophilic regions, the linking tyrosine-190 of the PRD1 terminal protein is found in a beta-sheet in a hydrophobic region.

Amino Acid Sequence↗
PubMed1991

Sequence requirements for protein-primed DNA replication of bacteriophage PRD1.

In vitro studies have demonstrated that linear duplex, protein-free DNA molecules containing an inverted terminal repeat (ITR) sequence of the PRD1 genome at one end can undergo replication by a protein-primed mechanism. No DNA replication was observed when the ITR sequence was deleted or was not exposed at the terminus of the template DNA. We have determined the minimal origin of replication by analyzing the template activity of various deletion derivatives. Our results showed that the terminal 20 base-pairs of ITR are required for efficient in vitro DNA replication. We have found that, within the minimal replication origin region, there are complementary sequences. A site-specific mutagenesis analysis showed that most of the point mutations in the complementary sequences markedly reduced the template activity. The analyses of the results obtained with synthetic oligonucleotides have revealed that the specificity of the replication origin is strand specific and even on a single-stranded template a particular DNA sequence including a 3'-terminal C residue is required for the initiation of PRD1 DNA replication in vitro.

Bacteriophages↗
PubMed1991

A horseradish peroxidase study of the fiber orientation in the facial nerve.

Horseradish peroxidase (HRP) was used to investigate the motor fiber orientation in the cat's intratemporal facial nerve. When HRP was applied to the zygomatic rami, HRP-labeled fibers were distributed diffusely throughout the labyrinthine and tympanic segments. On the other hand, distal to the chorda tympani entrance, a well-defined topographical orientation was found in the posterolateral aspect of the nerve. When HRP was applied to the buccal rami, topographical orientation was found in the posteromedial area of the distal mastoid segment. When HRP was applied to the posterior auricular rami, topographical orientation was found in the center to the anterior area of the distal mastoid segment. These results indicate that each branch of the facial motor nerve has a topographical orientation in the distal part of the mastoid segment, while nerve fibers are dispersed in the tympanic and labyrinthine segments.

Animals↗