PubMed Health⌕ Search

Biomedical subjects

K Uchizono

Publications and source records attributed to K Uchizono.

At least 19 recordsLinked to original sources
PubMed1992

Verbal versus non-verbal visual evoked potentials: Kanji versus line drawings.

Cortical areas related to perception of verbal and non-verbal stimuli were studied using VEPs. Kanji characters, line drawings (LD), or a blank were displayed. Verbal VEPs were obtained by subtracting the blank-VEPs from the Kanji-VEPs, and non-verbal VEPs by subtracting the blank-VEPs from the LD-VEPs. Both the verbal and non-verbal VEPs showed a negative peak (100-300 msec) focally over bilateral occipital, posterior temporal and parietal areas, and a positive peak diffusely over frontal halves. Differences between the non-verbal from the verbal VEPs showed an initial peak (100-200 msec) focally over bilateral occipital and posterior temporal areas, followed by a peak (200-300 msec) focally over bilateral posterior temporal areas. The frontal areas diffusely showed peaks at 100-200, 200-300 and 300-400 msec. Left-right asymmetries of both the verbal and non-verbal VEPs showed peaks between 100 and 300 msec over posterior temporal, parietal, and occipital areas. Left-right asymmetries of the subtraction to the non-verbal from the verbal VEPs showed a peak (100 msec) over occipital and parietal areas, and a broader peak over posterior temporal area (100-200 msec). Bilateral occipital, posterior temporal, and parietal areas are focally activated by the two perceptions (100-300 msec), while frontal areas are activated diffusely. Further, different processes may be focally involved between the hemispheres over occipital (100-200 msec) and posterior temporal (100-200 and 200-300 msec) regions. Initial left-right asymmetries of the subtracted VEP between the two perception would occur over occipital and parietal areas (100 msec) and last for 200 msec over posterior temporal area.

Acoustic Stimulation↗
PubMed1988

A new method for electron microscopic observation of isolated synaptic vesicles labelled with monoclonal antibody.

The immunoreaction of a monoclonal antibody (Mab) and an isolated synaptic vesicle (SV) was processed on a grid mesh and the result could be easily observed with electron microscopy. The SV suspension was obtained and dispersed on the grid mesh where immunoreaction procedures were performed. The resulting immunoreaction was visualized by labelling with ferritin particle (FAD) or horseradish peroxidase (HRP) for the electron microscopic observation. The SV specimen was observed by electron microscopy after faint negative staining with 1% uranyl acetate. With this method, the positive immunoreaction of Mab 171B5 and the isolated SV could be easily identified by the formation of a halo of FAD or a cobweb of HRP surrounding the SV. In the control experiment, the SV specimen was incubated with normal mouse serum instead of the Mab while the other procedures were performed in the same way. The SV was not outlined by FAD in the control experiment. Thus, the positive immunoreaction of the Mab and SV was thought to be an immunologically specific one. It was also determined that the Mab reacted specifically with the SV but not with the small membrane fragments and other unknown material. The present method seems to be useful for observing the immunoreaction of subcellular structures and their antibodies under electron microscopy.

Animals↗
PubMed1987

Four synaptic vesicle-specific proteins: identification by monoclonal antibodies and distribution in the nervous tissue and the adrenal medulla.

Synaptic vesicles from the guinea-pig cerebrum were isolated and administered to mice for the production of monoclonal antibodies (MAb). Four vesicle-associated proteins in the guinea-pig nervous tissue were specifically and differentially recognized by MAbs thus obtained. These proteins had molecular weights of 30,000, 36,000, 38,000 and 65,000 Da and were named SVPs (synaptic vesicle proteins) 30, 36, 38 and 65, respectively. Immunohistochemistry demonstrated that all SVPs were localized in the synaptic regions throughout the central nervous system and in the adrenal medulla. Nerve terminals in skeletal muscle, smooth muscle and sympathetic ganglion contained SVPs 36 and 38. Immunoelectron microscopy of the cerebellar cortex confirmed the localization of SVPs in the synaptic vesicles and the adjacent membranes of the presynaptic nerve terminals. Fractionation of the cerebral tissue and treatment with various agents showed that SVPs were localized in the synaptic vesicles and the synaptic plasma membrane and that SVPs were integrated within the membrane and liberated only after solubilization of the membrane.

Adrenal Medulla↗
PubMed1986

Identification of a synaptic vesicle-specific 38,000-dalton protein by monoclonal antibodies.

Synaptic vesicles were purified from the guinea pig cerebrum by sucrose density gradient centrifugation, and monoclonal antibodies (MAbs) were produced against this vesicle fraction. Seven MAbs (171B5, 171E8, 174D12, 174H11, 177A2, 177H11 and 178D4) recognized a novel acidic protein of about 38,000 daltons which was specific to synaptic vesicles. In immunofluorescence microscopy, the staining pattern of these MAbs corresponded to the distribution of the synapses in the guinea pig central nervous system. These MAbs appeared to stain all synaptic regions, irrespective of their synaptic function or type of neurotransmitters. MAb 171B5 and 174H11 stained the rat, rabbit and bovine synapses similarly to the guinea pig. Two other MAbs (171E8 and 177H11) stained other mammals weakly but the remaining 3 MAbs reacted only with the guinea pig. In immunoelectron microscopy of both the cerebellar tissue and isolated vesicle fraction, these MAbs selectively labeled the synaptic vesicles but not other structures. Immunoblot analysis was performed on electrophoretically separated proteins in vesicle fraction and brain homogenate. All of 7 MAbs reacted with a band at a molecular weight of about 38,000 from the guinea pig. Isoelectric focussing disclosed that this protein was acidic (pI 4.5-5).

Animals↗
PubMed1985

A new method for scanning and transmission electron microscopy of synaptic vesicles isolated from the cerebral cortex.

Spheroid and flattened synaptic vesicles were isolated from the brain homogenate of guinea pigs by a modified purification method. For scanning and transmission electron microscopy, a simple dipping method of preparation was developed and used. The purest and richest fraction of synaptic vesicles was obtained from a 0.1 M sucrose fraction of density gradients. The pellets of synaptic vesicles were easily resuspended without aggregate after ultracentrifugation at 40,000 rpm for 5 min. The isolated synaptic vesicles were dispersed as a monolayer on the surface of a copper grid covered with Formvar membrane. Adequate contrast was obtained by metal impregnation of specimens and gold coating at magnifications as high as 100,000 times using an acceleration voltage of 25 to 40 kV. The specimens were fixed in 0.75% glutaraldehyde (0.1 M phosphate buffer, pH 7.3) and then postfixed in 1% osmium tetroxide. After dipping for 1 to 2 min each in tannic acid, phosphotungstic acid, lead citrate and uranyl acetate, they were dehydrated with graded ethanol and coated with gold by ion sputtering at 400 to 560 volts for 4 min. The preparation method is reported on and technical problems are discussed.

Animals↗
PubMed1984

Little sleep-promoting effect of three sleep substances diurnally infused in unrestrained rats.

Delta-sleep-inducing peptide (2.5 nmol), prostaglandin D2 (0.36 nmol) and uridine (10 pmol) were intraventricularly infused for 10 h at daytime in otherwise saline-infused freely moving male rats. In contrast to a nocturnal infusion which may result in marked sleep-promoting effects, such a diurnal infusion brought about almost no change in sleep parameters. It is postulated that the requirement of sleep in rats might be fully achieved at the environmental light period to cancel the effect of the exogenously administered sleep substances. It is proposed that an endogenous sleep substance should be characterized by a property not to cause excessive sleep at the time when sleep is physiologically saturated.

Animals↗
PubMed1984

Uridine as an active component of sleep-promoting substance: its effects on nocturnal sleep in rats.

A 10-h intraventricular infusion of 10 pmol of uridine from 19.00 to 05.00 h resulted in significant increases in sleep in otherwise saline-infused male rats (n = 8) during the environmental dark period (20.00-08.00 h). Increments of slow wave sleep (SWS) and paradoxical sleep (PS) were 21.0% and 68.1%, respectively, of the baseline value. This was due to increases in the frequencies of both SWS and PS episodes but not to their durations. Similar increases occurred the first recovery night under saline infusion, but sleep amounts returned to the baseline levels the second night. Brain temperature was not affected by uridine administration. A small dose of uridine (1 pmol/10 h) exerted no effect (n = 6) while larger doses (100 and 1000 pmol/10 h, each n = 5) resulted in slight but insignificant increases in SWS and PS. The 1000-pmol uridine administration seemed to be non-physiological since it brought about irregularities in locomotor activity and sleep-waking rhythms. Thus, authentic uridine exhibited the same sleep-enhancing effects as a naturally occurring active component of sleep-promoting substance, which was recently identified with uridine.

Animals↗
PubMed1984

Differential sleep-promoting effects of five sleep substances nocturnally infused in unrestrained rats.

Sleep-inducing and sleep-maintaining effects of five different putative sleep substances were compared by the same nocturnal 10-hr intracerebroventricular infusion technique in otherwise saline-infused, freely moving male rats. Delta-sleep-inducing peptide (2.5 nmol), which induces electroencephalogram delta (slow)-wave patterns, was rapidly effective in increasing both slow-wave sleep and paradoxical sleep but the effects were not long-lasting. Muramyl dipeptide (2 nmol) induced excessive slow-wave sleep in the middle of the infusion period, accompanying a simultaneous elevation of brain temperature. However, paradoxical sleep was not affected. Component B of sleep-promoting substance (2 brainstem equivalents), a partially purified extract from rats deprived of sleep for 24-hr, was markedly effective in inducing and maintaining both kinds of sleep. Prostaglandin D2 (0.36 nmol) was more effective in enhancing sleep at the later period of the infusion period. Uridine (10 pmol) caused a mild but long-lasting increase in sleep, especially in paradoxical sleep. Thus, each substance exhibited compound-specific sleep-modulating properties.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1977

[Rearing and management of chimpanzees for experimental infection with hepatitis B virus (author's transl)].

For the purpose of experimental infection with human hepatitis B virus, 14 chimpanzees (Pan troglodytes) were delivered to the Division of Animal Research, Faculty of Medicine, University of Tokyo, Tokyo. These chimps, 11 males and 3 females, born in the West Africa, had been reared for two to six months. Several days after delivery, they were anesthetized with Ketalar in order to make clinical, bacteriological and parasitological examinations; It was found that one of them was in malnutrition, and that another had dislocation of the shoulder joint and the associating abscess. All of them were negative for tuberculin test. In the bacteriological examination, Shigella sonnei was detected in the feces from one of them. Mycoplasma sp. was detected in the materials from the oral cavity of four head. As intestinal parasites, Ascaris sp. were detected in two head, Enterobius vermicularis in eight, Strongloides sp. in two, Oesophagostomum sp. in nine, tape worms in four, and Entamoeba coli in twelve. Microfilaria as blood parasite was detected in 11 of them. The laboratory used for the experimental infection was a room occupying about 42 m2, which had been built by renovating a part of our division building. Each of the cages used for rearing the chimps was contained in the isolation box made of stainless steel. The contaminated air in the isolation box was discharged forcedly into the exhausting duct with a fan, and further passed through the HEPA filter and the Miraceram honeycomb heater, and was then conducted to the already existing ventilation duct of the division building. Each chimp was fed on a ration of 200-350 g of the imported "Purina Monkey Chow 25" and also one grapefruit and one banana daily for the supply of vitamin C. The chimps weighed 16.1 kg on the average on delivery, but gained an average weight of 4.2 kg during the following four months.

Animal Husbandry↗