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Biomedical subjects

Y Maki

Publications and source records attributed to Y Maki.

At least 253 records · Page 14Linked to original sources
PubMed1979

Antiallergic action of 6-ethyl-3-(1h-tetrazol-5-YL) chromone (AA-344) on immediate hypersensitivity reaction in rats.

A newly synthesized compound, 6-ethyl-3-(1H-tetrazol-5-yl)chromone (AA-344) given intravenously or orally inhibited considerably the 72-hr passive cutaneous anaphylaxis (72-hr PCA) induced by IgE in rats. The antiallergic action of AA-344 was neither due to the antihistamine or antiserotonin effect nor was it mediated via adrenergic mechanisms. The results obtained in a double sensitization with two IgE antibodies suggest that AA-344 may not impair antigen-antibody combination but probably prevents the release of chemical mediators including histamine. This assumption was supported by observation that AA-344 inhibited a reduction in the skin histamine content caused by the 72-hr PCA, without effect on the compound 48/80-induced histamine reduction. AA-344 also partially inhibited the IgGa-mediated 3-hr PCA in rats. These results indicate that the inhibitory action of AA-344 on the immediate hypersensitivity reactions is due to prevention of the release of chemical mediators from the mast cells, by acting on some process in sequential events leading to the mediator release following antigen-antibody combination.

Adrenalectomy↗
PubMed1979

Inhibitory action of 6-ethyl-3-(1H-tetrazol-5-YL)chromone (AA-344) on IgE, IgGa- or chemical agent-induced histamine release from isolated rat mast cells.

The antiallergic action of 6-ethyl-3-(1H-tetrazol-5-yl)chromone (AA-344) was studied on isolated rat peritoneal mast cells. AA-344 clearly inhibited the IgE-mediated release of histamine caused by various concentrations of antigen and the 50% inhibitory concentration was 0.1 microM. On the IgGa-mediated release of histamine, a peak inhibition of AA-344 was observed at 10 microM. The histamine release induced by chemical agents such as concanavalin A, dextran and compound 48/80 was depressed by AA-344 at the range of 0.1--1 mM. The results obtained in this study indicate that the antiallergic action of AA-344 is due to selective inhibition on the immunological release of the chemical mediator from mast cells.

Animals↗
PubMed1979

Effect of 6-ethyl-3-(1H-tetrazol-5-yl)chromone (AA-344) on the immediate and delayed hypersensitivity reactions.

Effects of 6-ethyl-3-(1H-tetrazol-5-yl)chromone (AA-344) on the experimental models of the type I-IV allergic reactions were studied in comparison with those of disodium cromoglycate (DSCG), dexamethasone and other agents. AA-344 showed inhibitory effects on the homologous passive cutaneous anaphylaxis and the passive systemic anaphylaxis in guinea pigs. However, it had only a slight or little effect on the Forssman shock in guinea pigs, the complete-dependent cytolysis of mast cells in rats, the Arthus reaction in guinea pigs and the tuberculin reaction and the contact sensitivity in mice. DSCG was less effective, using these experimental models. Dexamethasone showed a suppressive effect on the type III and IV allergic reactions. The results indicate that AA-344 selectively suppresses the type I allergic reaction.

Animals↗
PubMed1979

Computed tomography in tuberous sclerosis--with special reference to relation between clinical manifestations and CT findings.

Concerning the clinical signs and symptoms, we noticed skin white macula in 87%, adenoma sebaceum in 53%, mental retardation in 75%, retinal phacoma in 54% and seizure in 92%. Numbers of nodules ranged from zero to 11, and showed no correlation with aging. Half of the cases showed slight ventricular dilatation, one quarter showed moderate dilatation and the remainder were normal. There was no definite correspondence between size of the ventricle and number of nodules. There were relatively many cases with normal mental state in the group with normal ventricles. In adult cases a large ventricle does not always mean poor prognosis in mental state. Almost all of the cases with cortical atrophy had mental retardation. In the group with moderate dilatation infantile spasms were the most frequent type of seizure. On the contrary, grand mal was most frequent in the normal group. As for the position of nodules there was no difference between the normal and dilated groups. Nodules were predominantly seen in the lateral aspect of the body, trigone of the lateral ventricle and adjacent to the foramen of Monro. Asymmetrical lateral ventricles were noticed in 18%. Incidence of laterality increased as dilatation proceeded. It was larger on the left side in 9 out of 11 cases. We have no reasonable explanation of this tendency. There was one case with a tumor which was verified by enhanced CT. There were five cases with brain anomalies.

Adolescent↗
PubMed1979

[A case with giant aneurysm of distal portion of the posterior inferior cerebellar artery (author's transl)].

A case of a giant aneurysm of the distal posterior inferior cerebellar artery has been presented, in which the preoperative sympotoms were those of a space occupying lesion of the posterior fossa. CT scan revealed a round mass in the cerebellum. The wall of this round mass was not enhanced after an intravenous administration of iodine. At operation we found a large saccular aneurysm, about 3 cm in diameter, arising from the distal portion of the left posterior inferior cerebellar artery. By needle decompression and dissection around the aneurysm, we were able to place a Heifetz clip across the neck. After exicision, the aneurysm was found to contain a large thrombus.

Aged↗
PubMed1979

[Computed tomography in crossed aphasia (author's transl)].

Crossed aphasia, first described by Bramwell, is aphasia due to the hemispheric damage on the side of handedness. Crossed aphasia in a dextral is rare, and in Japan, there have not been more than ten cases in which the lesion is localized clearly. The cases reported till now have been verified mainly by necropsy. However, the time lag between the appearance of aphasia and the necropsy may affect the conclusion subtly. We consider that computed tomography (CT) can obtain almost the same findings as that by necropsy. However, at present there have been few cases diagnosed by CT except two cases reported by April et al. and Wechsler. We have reported a 47-year-old man in a dextral, who shows left hemiparesis and Broca's aphasia. His lesion is diagnosed by cerebral angiography and CT as the right hemisphere infarction due to right middle cerebral artery occlusion. CT localizes the lesion on the right hemisphere mainly sited deep region and sited wedge shaped cortical area of the fronto-parietal region. On the other hand, it localizes no lesion on the left hemisphere. CT in aphasia has been already reported by Hayward et al. In their report they concluded that correlation of lesion located by CT with aphasia type supported Geschwind's concept of aphasia. In this report we have discussed CT in crossed aphasia analysing our case and the two cases by April et al. and Wechsler. Three cases including our case are all Broca's aphasia, and we compare the lesion location of these three cases with Hayward's lesion located on Broca's aphasia. As the result of this, we can draw the conclusion that the lesion location by CT of these three cases and that of Hayward's report are almost symmetric.

Aphasia↗
PubMed1979

[Computed tomography in metastatic brain tumors and meningeal carcinomatosis (author's transl)].

The computed tomogrpahy has been proved to be highly reliable in diagnosis of CNS diseases. The findings in 26 cases of metastatic brain tumors, and 2 cases of meningeal carcinomatosis performed with Hitachi CT-H scanner are analized. Metastatic tumors are seen on plain CT as mainly isodense nodules (60%). But, on enhanced CT, they increase in their density (97%). Larger nodules of metastatic tumors (over 2 cm in diameter) are tend to contain less dense central area, so called central cavitation. The direction of the expansion and/or extension of the perifocal low density is characteristic to the location of the tumor. In cases of meningeal carcinomatosis, diffuse periventricular higher density can be recognized enhanced CT.

Adult↗
PubMed1978

Biliary spasmolytic action of 3-(2,4,5-triethoxybenzoyl)propionic acid (AA-149) in dogs.

The spasmolytic action of 3-(2,4,5-triethoxybenzoyl)propionic acid (AA-149) on the biliary tract was investigated in anesthetized dogs. Intravenous administration of AA-149 at 2 mg/kg and higher doses produced a dose-dependent reduction in passage resistance through the choledochoduodenal junction and in gallbladder pressure, and a dose-dependent increase in bile flow. AA-149, like cholecystokinin, decreased biliary ductal pressure in spite of increasing the bile flow in dogs with ligation of the cystic duct of the gallbladder, whereas taurocholate increased the pressure as well as the bile flow. Moreover, the spasmic response of the choledochoduodenal junction to morphine was depressed strongly by AA-149, BUT NOT CONSISTENTLY BY ATROPINE. The effects of AA-149 were not influenced by pretreatment with atropine, phentolamine or propranolol. These findings strongly suggest that AA-149 relaxed the biliary tract and depressed the morphine-induced spasm by a mechanism different from those of anticholinergic and sympathomimetic agents.

Animals↗
PubMed1978

A possible mechanism of choleretic action of 3-(2,4,5-triethoxybenzoyl)-propionic acid (AA-149) in dogs.

The choleretic action of 3-(2,4,5-triethoxybenzoyl)propionic acid (AA-149) was studied in anesthetized dogs. AA-149 produced a dose-dependent increase of the bile flow with both i.v. and intrajejunal administration of doses 1 mg/kg and higher. Biliary clearance of 14C-erythritol showed that AA-149 stimulated canalicular bile formation without enhancement of water secretion and/or inhibition of bile reabsorption in the biliary ductules and ducts. AA-149 did not increase the excretion of bile acids into the bile, but enhanced the excretion of the biliary electrolytes, in particular sodium ion, in proportion to an increase of the bile flow. About 3--4% of AA-149 administered i.v. was excreted into the bile during the first 1 h period, so that biliary AA-149 was insufficient to increase the bile flow via its osmotic effect. These results strongly suggest that the choleretic action of AA-149 is attributable to stimulation of a bile acid-independent bile formation in the canaliculi coupled with an active sodium transport system.

Animals↗