Search PubMed⌕ Search

Biomedical subjects

H Shimazu

Publications and source records attributed to H Shimazu.

At least 199 records · Page 11Linked to original sources
PubMed1978

[Subacute toxicity test of AMI-U-II, a new amino acid solution for renal failure (author's transl)].

Subacute toxicity test of AMI-U-II was carried out using male and female JCL:SD rats. The animals were given intravenously AMI-U-II (80, 40 and 20ml/kg) or reference solution (80 and 40ml/kg) for five weeks. Tachypnea, depression of spontaneous activity, blepharoptosis and edema of face were observed in rats treated with AMI-U-II or reference solution at highest dose. Food consumptions and gaining body weight were slightly reduced in male of these animals, but water intakes were increased in both sexes. Autopsies of the animals which died during five weeks showed pulmonary congestion and/or edema, ascites and pleural effusion. Microscopically, hydropic degeneration of liver cells and dilation of renal tubules and Bowman's capsules were shown. It seems likely that most of these findings were caused by hypervolumic administration of amino acid solution.

Amino Acids↗
PubMed1977

[Statistical analysis of 1186 cases of gastric carcinoma: with special reference to advanced lesion (author's transl)].

750 cases of advanced gastric carcinoma were macroscopically and microscopically studied in relation with the 10 year survival rate. Most of the patients, 59.3% in female and 68.8% in male, belonged to the 5th and 6th decades. Macroscopically 44.1% of the cases were grouped in Borrmann III type, and secondly Early-Cancer Like Lesion, 26,6%. Histologically, in 510 cases out of 750 (68.0%) serosa was definitely broken by carcinoma cell nests and in 500 cases (66.7%) lymphnode metastasis was observed. The most frequent histological type was diffuse type, 44.9%, and secondly papillotubular type, 21.2%. 10 year survival rate of 516 cases, in which no residual cancer tissue was ascertained and the favorite prognosis could be expected was studied on various factors: Early-Cancer-Like-Lesion and Borrmann I & II types carcinoma, those cases in which the muscularis propria or serosa was preserved, those cases without lymphnode metastasis, and papillotubular or medullary tubular carcinomas showed a favorite prognosis in comparison with other types.

Adult↗
PubMed1976

Transcerebellar inhibitory interaction between the bilateral vestibular nuclei and its modulation by cerebellocortical activity.

In decerebrate, unanesthetized cats, the brain stem was longitudinally cut at the midline from its dorsal to ventral surface with the cerebellum kept intact, eliminating neural interactions between the bilateral vestibular nuclei through the brain stem. Extracellular spike potentials of vestibular type I neurons identified by horizontal rotation were distinctly inhibited by contralateral vestibular nerve stimulation. This crossed inhibition was abolished by removal of the medial part of the cerebellum, indicating that the inhibition was mediated through the cerebellum. Neither aspiration of the flocculus on the recording side nor intravenous administration of picrotoxin eliminated transcerebellar crossed inhibition, suggesting that it is mediated through the cerebellar nuclei. When the fastigial, interposite and dentate nuclei were stimulated, inhibition of vestibular type I neurons was produced only from the contralateral fastigal nucleus. Cerebellocortical stimulation which inhibited fastigial type I neurons suppressed transcerebellar crossed inhibition. Effective sites for suppression of transcerebellar crossed inhibition were localized to lobules VI and VIIa in the vermal cortex on the side of labyrinthine stimulation. Intracellular recordings were made from type I neurons in the medial vestibular nucleus. Stimulation of the contralateral vestibular nerve and the contralateral fastigial nucleus produced IPSPs in these neurons with the shortest latency of 3.8 msec and 1.8 msec, respectively. The difference between these two latency values approximates the shortest latency of spike initiation of fastigial type I neurons in response to vestibular nerve stimulation. It is postulated that transcerebellar crossed inhibition is mediated through the fastigial nucleus on the side of labyrinthine stimulation.

Brain Stem↗
PubMed1976

Mossy fiber neck and second-order labyrinthine projections to cat flocculus.

In five decerebrate cats and in two under N2O-O2 anesthesia, a bipolar electrode array was inserted into a granular layer in the rostral flocculus. At this location MF field potentials were evoked by stimulation of the ipsilateral vestibular nerve and of the C2 dorsal root ganglion. Stimulation through the array was used to fire brain stem neurons antidromically. The activity of these neurons was recorded extracellularly with glass microelectrodes. Stimulation of the C2 dorsal root ganglion evoked in the caudal lateral brain stem a field potential caused by the arrival of impulses in primary afferent fibers. Cells projecting to the flocculus also responded to the stimulus, usually monosynaptically. These neurons were fired by stimulation of the area of the atlantoaxial joint. They did not respond to stimulation of the contralateral C2 dorsal root ganglion, and responded only rarely to stimulation of the dorsal rami of the C2 and C3 spinal nerves. Stimulation of the vestibular nerve was ineffective. Another group of cells projecting to the flocculus was fired at short latency by stimulation of the ipsilateral vestibular nerve. These neurons were usually inhibited by stimulation of the contralateral vestibular nerve. They were not affected by stimulation of any neck afferents. The location of many recording locations was identified by means of fast green dye marks. Most neurons relaying neck activity were in group x of Brodal and Pompeiano (4), a few were in the external cuneate nucleus, and one was in the descending vestibular nucleus. Neurons relaying labyrinthine activity were in the descending vestibular nucleus; one was found in the medial nucleus, in which tracks were made only rarely. There are two parallel pathways relaying neck and labyrinthine activity to the flocculus. While they are separate at the level of the brain stem, they converge in the same rostral areas of the flocculus. The neck afferent information may be required for proper performance of the flocculus in eye-movement control.

Animals↗
PubMed1975

Simple differential Giemsa staining of sister chromatids after treatment with photosensitive dyes and exposure to light and the mechanism of staining.

The essential steps of the 33258 Hoechst-Giemsa method for differential chromatid staining consist of (1) 33258 Hoechst treatment, (2) exposure to light, and (3) Giemsa staining. The staining was shown to be a function of the concentration of 33258 Hoechst and the light exposure. The dye was successfully replaced by various metachromatic dyes such as thionine. Two simple methods are proposed. Failure of the pale stained chromatids to restore Giemsa affinity with urea and trypsin and the diminished Feulgen reaction after light exposure suggest that not masking proteins but photolysis of the BrdU-incorporation chromatid components in the present of photosensitive dyes play a role in the differential staining.

Animals↗
PubMed1975

Functional organization of vestibulofastigial projection in the horizontal semicircular canal system in the cat.

Spike potentials of fastigial nucleus neurons were recorded extracellularly in decerebrate, unanesthetized cats. The neurons responding to head rotation in the horizontal plane with a type I fashion were located mainly in the middle and caudal regions of the fastigial nucleus. Three fourth of these fastigial type I neurons were antidromically activated by stimulation of the contralateral vestibular nuclei. These neurons were excited transsynaptically from the ipsilateral vestibular nerve or nuclei. Intra cellular recordings were made from those neurons which were located in the caudal half of the fastigial nucleus and were activated antidromically from the contralateral vestibular nuclei. Stimulation of the ipsilateral vestibular nerve produced EPSPs in these neurons with latencies of 1.0-6.6 msec. The shortest conduction time along primary vestibular aggerents from the labyrinth to the ipsilateral fastigial nucleus was 0,7 msec. The EPSPs with the shortest latency of 1.0 msec were therefore postulated to be due to monosynaptic connections of primary vestibular afferents with fastigial neurons. Stimulation of ipsilateral vestibular nuclei also produced monosynaptic EPSPs in fastigial neurons. These EPSPs were facilitated by conditioning stimulation of the ipsilateral vestibular nerve, indicating the existence of polysynaptic activation of fastigial neurons from the ipsilateral vestibular nerve through the vestibular nuclei.

Animals↗