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J Ito

Publications and source records attributed to J Ito.

At least 361 records · Page 20Linked to original sources
PubMed1982

Interaction of glia maturation factor with the glial cell membrane.

Glia maturation factor (GMF) immobilized on agarose beads retained the same mitogenic and morphological transforming activities as free GMF when tested on glioblasts. The exposure of glioblasts to immobilized GMF for 5 min provoked the initiation of DNA synthesis and maximal stimulation was obtained within 30 min. Thiol-reducing agents, such as dithiothreitol and cysteine, increased the biological activity of GMF. These data suggest the presence of a surface receptor to GMF on the glioblasts, while the reduction of the thiol group(s) in GMF promotes the binding to its receptor. Repeated use of immobilized GMF decreased both the mitogenic and the morphological transforming activities. Immobilized GMF used for the third time lost its biological activity. This implies the existence of a certain kind of degradation system such as a proteolytic enzyme located close to the GMF receptor on the glial cell surface.

Animals↗
PubMed1982

Afferent projection from reticular nuclei, inferior olive and cerebellum to lateral vestibular nucleus of the cat as demonstrated by horseradish peroxidase.

Afferent connection to lateral vestibular nucleus (LVN) was examined using retrograde transport of horseradish peroxidase (HRP). When HRP was microiontophoretically applied to the immediate vicinity of the LVN neuron, which monosynaptically fired spike upon VIIIth cranial nerve stimulation, HRP-labelled cells were observed in the ipsilateral lateral reticular nucleus, bilateral gigantocellular nucleus, and contralateral dorsal cap and beta-nucleus of inferior olive in addition to various parts of cerebellum.

Afferent Pathways↗
PubMed1982

Inhibitory effect of betahistine on polysynaptic neurons in the lateral vestibular nucleus.

Effects of betahistine, an antivertigo drug, were examined on the lateral vestibular nucleus (LVN) neurons of cats anesthetized with alpha-chloralose. Spike generation of monosynaptic LVN neurons elicited by vestibular nerve stimulation remained unaffected with intravenous administration of betahistine up to 5 mg/kg and with iontophoretic application of the drug up to 200 nA. In contrast, the spike generation of polysynaptic I neurons in the LVN was dose-dependently inhibited by intravenous as well as iontophoretic application of betahistine. These results suggest that small doses of betahistine more selectively interfere with synaptic transmission in the polysynaptic I neurons than in the monosynaptic neurons.

Animals↗
PubMed1982

Inhibition by calmodulin antagonists of glioblast DNA synthesis and morphological changes induced by glia maturation factor.

Calmodulin antagonists, N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide hydrochlorides (W-7) and trifluoperazine (TFP), markedly inhibited both morphological transforming and mitogenic activities of glia maturation factor (GMF) on rat fetal glioblasts in culture. In the presence of W/-7 (16.5 microM) or TFP (9 microM) the formation of glial processes of glioblasts caused by GMF was decreased, and DNA synthesis (measured by the incorporation of [methyl-3H]thymidine into DNA was inhibited by 50% without changing cell viability. Kinetic analysis of dose-response experiments revealed a noncompetitive fashion of inhibition by W-7 and a mixed fashion by TFP. W-7 appeared to inhibit DNA synthesis at the G1 phase immediately before the beginning of the S phase. The results strongly suggest that calmodulin exerts a significant role on cell multiplication induced by the growth factor.

Animals↗
PubMed1982

Nucleotide sequence of the major early region of bacteriophage phi 29.

The nucleotide sequence of the left end of bacteriophage phi 29 DNA has been determined. Together with data reported earlier (Yoshikawa et al., 1981), this sequencing comprises the major early genetic region of this viral genome (5708 bp). Computer analysis of the DNA sequences revealed that there are up to fifteen open reading frames which could encode polypeptides containing more than thirty amino acids. The DNA sequence also revealed a number of potential regulatory signals, promoters and ribosome binding sites. The initiation and the termination of transcription and probable early gene products are discussed.

Bacillus subtilis↗
PubMed1982

In vitro replication of bacteriophage phi 29 DNA.

We have been studying the mechanisms of linear DNA replication by using Bacillus bacteriophage phi 29 as a model system. To isolate and characterize the proteins required for phi 29 DNA replication, we have developed a cell-free replication system. A cell-free extract prepared from phi 29-infected Bacillus subtilis catalyzes the semiconservative replication of phi 29 DNA, but only if exogenous phi 29 DNA-protein complex is used as the template. This template consists of linear duplex DNA with a 30,000-dalton terminal protein attached covalently to both 5' ends. Replication starts nonsimultaneously at or near both ends of the template. The extract also catalyzes the specific binding between dATP and the phi 29 terminal protein. Thus, the in vitro system closely mimics the in vivo replication of phi 29 DNA. This system should allow characterization of the phi 29 DNA replication machinery.

Bacillus subtilis↗
PubMed1982

Computed tomography in moyamoya disease.

Eighteen patients with moyamoya disease were examined by computed tomography (CT). At the first examination, CT findings were normal in one patient and abnormal in 17 patients. Significant abnormalities on precontrast CT were characterized by low density lesions in 14, ventricular dilatation in 9, and cerebral atrophy in 11 patients. Postcontrast CT showed the presence of contrast enhanced lesions in three patients. Follow-up examinations were performed in 13 patients, and the following changes on CT were found in 10 of them: increase or development of low density lesions in 10, ventricular dilatation in 4, cerebral atrophy in 5, appearance of a contrast enhanced lesion in 1, and disappearance of the enhanced lesion in 3. The patient with normal findings at the first examination showed a low density lesion on the second examination. The abnormal vascular networks in the region of the basal ganglia were visualized successfully in six examinations of five patients by higher concentration of contrast medium in blood than usual. Abnormal CT findings consisted of those seen in multiple cerebral infarctions and the visualization of the abnormal vascular networks. Computed tomographic findings on these patients showed evolution as seen in clinical and angiographic findings.

Adolescent↗