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Biomedical subjects

Y Maki

Publications and source records attributed to Y Maki.

At least 217 records · Page 12Linked to original sources
PubMed1982

Immunohistochemical demonstration of LHRH-neurons in young rat hypothalamus: light and electron microscopy.

Localization and ultrastructural appearance of immunoreactive LHRH neurons were studied in 2-, 8- and 21-day-old rats. The lower half of the diencephalon including the septo-preoptic area was serially cut at 10 microns in the frontal plane, and all sections stained with an anti-LHRH serum were examined light microscopically. Although the antiserum could not demonstrate LHRH-immunoreactive perikarya in adult rats, they were stained in these young rats. The immunoreactive perikarya were scattered in the following regions: nucleus tractus diagonalis, medial septum, medial preoptic area, lateral septum, lateral preoptic area, tuberculum olfactorium, suprachiasmatic area, supraoptic area, pericommisural area, anterior commissure, vascular organ of the lamina terminalis (OVLT), lateral hypothalamic region and lateral tuberal region. The first three regions contained many cells but others showed only sporadical cells. The cells were most frequently observed in 8-day-old rats. Most of the cells appeared to be bipolar showing two immunoreactive processes. Electron microscopy observation was made using the section prepared by a pre-embedding technique. In the immunoreactive perikarya, secretory granules, ribosomal particles, and the particles on the outer surface of endoplasmic reticulum appeared to be immunoreactive, but the Golgi area was immunonegative. The secretory granules appeared along the cytoplasmic membrane but were surprisingly few in number. By contrast, the immunoreactive nerve terminals in the median eminence and in the OVLT contained many granules. These findings suggest that LHRH produced in the perikarya is prompted to be transported and stored in the axonal terminals.

Aging↗
PubMed1982

[Late vascular effects in irradiated mice brain: in relation to experimental radionecrosis (author's transl)].

The whole brains of mice were irradiated with 250 kVp X-ray at 120 rad min-1 (1.6 mm Cu HVL, TSD 50 cm) and a histological study was done. The dose range of X-irradiation was from 1300 to 2500 rads. i.e., 1300, 1500, 1750, 2000, and 2500 rads. In the microscopic examination, the mice were killed at the regular postirradiation intervals of between 15 and 20, 31 and 40, 41 and 50, 51 and 60, 61 and 70, 71 and 80, 81 and 90, 139 and 177 weeks. A histological examination was performed by a morphometric estimation of vascular lesion in which the degree of the damage to the arterial system was scored through whole serial brain sections. Necrosis (encephalomalacia), atrophy, cell infiltration, and telangiectatic vascular change of the brain, caused as a result of the fibrinoid necrosis of the large artery were observed. Incidence of the fibrinoid necrosis increased dose dependently between 41 and 87 weeks after irradiation. Mean score of fibrinoid necrosis increased dose dependently approximately 60 weeks after irradiation. It is suggested that scores of large vessel damage do relate to dose at 41-87 weeks and can be used to quantify the vessel injury and a fibrinoid necrosis of the large vessels may relate to the incidence of radionecrosis.

Animals↗
PubMed1981

Electron microscopic study of immunoreactive LHRH perikarya with special reference to neuronal regulation.

In early postnatal rats, immunoreactive LHRH perikarya in the preoptic area were studied by light and electron microscopy. Synaptic junctions were found between the immunoreactive perikaryon or its process, and the immunonegative nerve fibers. The significance of these synapses is discussed in relation to possible mechanisms by which the activities of LHRH neurons are regulated.

Animals↗
PubMed1981

Suspected intraaqueductal perinatal hemorrhage in congenital hydrocephalus.

A 8-day-old boy with congenital hydrocephalus was given a shunt operation. Computed tomography (CT) revealed marked internal hydrocephalus and a high density area about the aqueduct of Sylvius, in the fourth ventricle and perhaps partly in the third ventricle which was completely absorbed one month later. Later conray ventriculography demonstrated aqueductal obstruction. Neuroradiologically there was neither neoplastic nor vascular lesion. The patient achieved almost normal motor and mental development at 9 months of age. The cephalopelvic discrepancy and vacuum extraction are thought to be the most likely caused of the hemorrhage. The site of hemorrhage was quite unusual as a neonatal intraventricular hemorrhage.

Cerebral Hemorrhage↗
PubMed1981

Computed tomography in von Recklinghausen's disease.

Though we knew it would be difficult to predict whether a child having von Recklinghausen's disease would develop a central nervous system lesion in the future, we tried to find a clue to this question in our study, by comparing computed tomography (CT) findings of 18 children with those of 21 adults. 55% of the children and 85% of the adults showed abnormal findings on CT. The most common finding was mild ventricular dilatation without periventricular hypodensity. Some of them showed ventricular stasis without block on radioisotope cisternography.

Adolescent↗
PubMed1981

Platelet aggregation in patients with Moyamoya disease.

Platelet aggregation was studied by giving ADP or adrenalin to 28 patients with Moyamoya disease. There were 7 males and 21 females, and 27 normal controls, 11 males and 16 females. We found that 2 muM of ADP, and 9.1 and 22.7 muM of adrenalin induced statistically significant increases in nondissociative patterns of platelet aggregation in the patient group. Maximum aggregation was significantly increased in the patient group compared with the controls by the addition of ADP (2 and 4 muM) or adrenalin (9.1 and 22.7 muM). When patients were divided into two groups under and over 20 years of age, there was no discernible difference of platelet aggregation in either group.

Adenosine Diphosphate↗
PubMed1981

Nucleotide requirements for DNA replication of SV40 chromatin in digitonin-treated and saponin-treated permeable cells.

Permeable cell systems have been developed by treatment with digitonin or saponin for studying in vitro DNA replication of chromatin. DNA replication of SV40 nucleoprotein complexes (SV40 chromatin) in these systems requires the addition of ATP, dCTP, dGTP, dTTP, and Mg2+. Further addition of three other ribonucleoside triphosphates slightly increased DNA synthesis. Omission of ATP greatly reduced DNA synthesis. In the presence of ATP, however, omission of dATP did not significantly alter or rather slightly enhanced DNA synthesis. Analysis of replicated SV40 DNA by gel electrophoresis and autoradiography indicated that complete replication of SV40 DNA and chromatin occurred in these systems

Animals↗
PubMed1981

Indomethacin produces gastric antral ulcers in the refed rat.

Indomethacin produces gastric corpus erosions in the fasted rat and small intestinal ulcers in the conventionally fed rat. We found that in rats fed chow pellets for 1 h after a 24-h fast, indomethacin given within 2 h after refeeding produced lesions in the gastric antrum, primarily along the lesser curvature, and also in the small intestine. The antral lesions reached a maximum size in 6-10 h, penetrated the muscularis mucosae within 3 days, and did not diminish for at least 7 days. The formation of the antral ulcer was prevented by prostaglandins or adrenalectomy, but was not affected by cimetidine, atropine, and/or vagotomy. In contrast, the gastric corpus erosions produced by indomethacin in the fasted rat were prevented by antisecretory drugs or vagotomy, and were aggravated by adrenalectomy. It is concluded that: (a) the chronic antral ulcers produced by indomethacin in a refed rat mimic human gastric ulcer with regard to location and histology; and (b) the mechanism of antral ulcer formation is different from corpus erosion formation, in that it was resistant to antisecretory drugs and vagotomy and was prevented by adrenalectomy. This experimental ulcer model could prove useful for studies of the etiology and therapy of gastric ulcer disease.

Adrenalectomy↗
PubMed1981

[Clinical application of cefsulodin to Pseudomonas aeruginosa infections in the surgical field (author's transl)].

Cefsulodin (CFS), a new antipseudomonas cephalosporin, was clinically evaluated for treatment of the Pseudomonas aeruginosa infections in the surgical field to obtain the following results. 1. CFS was administered to total 11 cases of the surgical infections caused by P. aeruginosa, comprising of 5 cases with wound infections, 3 cases with infected burn and 1 case each with muscular abscess, decubitus and postoperative pneumonia in 0.5 approximately 1 g twice a day by intravenous bolus or drip infusion. Good clinical responses were obtained in 9 out of 11 cases (81.8%). 2. Bacteriological responses were observed in all cases. P. aeruginosa was eradicated in 9 cases and suppressed in 2 cases by CFS treatment. However, replacement of pathogens with the other organisms was observed in 6 out of 8 cases caused by P. aeruginosa only. 3. Neither objective and subjective side effects nor abnormalities of laboratory tests associated with CFS treatment were observed. 4. It can be, therefore, concluded that CFS is one of the useful drugs for treatment of the surgical infections caused by P. aeruginosa.

Adult↗
PubMed1981

[Computed tomography in hypertensive cerebellar hemorrhage (author's transl)].

Fourteen cases of cerebellar hemorrhage were analysed from the point of CT-scan, and the following results were obtained. 1. The number of cases of cerebellar hemorrhage forms 4.4% of that of total intracranial hemorrhage. 2. Most of the cerebellar hematomas extend upward. Downward extension is rare. 3. In acute dead cases hematomas are 5 cm or more in diameter and lie over bilateral hemistpheres with the extension to third or fourth ventricles in CT-scans. 4. Slowly progressive cases are deteriorated by the secondary hydrocephalus. 5. In mild cases hematomas are 3cm or less in diameter on CT-scans and the hematoma evacuation is not indicated for these cases. 6. The shunt operation alone is sufficient for the life saving of the slowly progressive cases, but the hematoma evacuation is indicated in these cases if the functional prognosis is taken into consideration. 7. Immediate hematoma evacuation together with the ventricular drainage is considered to be effective for the life saving of the acute fulminant cases.

Aged↗