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Biomedical subjects

M Kitahara

Publications and source records attributed to M Kitahara.

At least 163 records · Page 9Linked to original sources
PubMed1985

Endolymphatic hydrops in guinea pigs after cauterizing the sac with silver nitrate.

There have been several reports of perisaccular fibrosis of the endolymphatic sac in some autopsied cases of Meniere's disease. We attempted to initiate perisaccular fibrosis of the sac in guinea pigs by injecting a small amount of 10% silver nitrate solution that cauterizes the tissue readily to produce scar, ie, fibrosis. Ninety-nine guinea pigs out of 108 (92%) that were treated with silver nitrate showed the endolymphatic hydrops in varied extent, from slight to profound. The extent of hydrops might depend on the extent of destruction of the sac following the cauterization. The lumen of the sac was sometimes occupied with dense fibrous connective tissue with deposition of black-silver particles in it. The silver nitrate injection method is an easy way to produce endolymphatic hydrops in guinea pigs.

Animals↗
PubMed1985

Diffuse form of primary leptomeningeal gliomatosis. Case report.

Primary leptomeningeal gliomatosis is rare, and the diffuse form is even rarer with only three cases reported in the literature. A fourth case is described in this report. Computerized tomography (CT) findings showed hydrocephalus with enhancement of the cerebral cisterns, and analysis of cerebrospinal fluid obtained by lumbar puncture showed many atypical cells. Based on these findings, a diagnosis of leptomeningeal tumor was made. There was some improvement in neurological and CT findings following radiotherapy and chemotherapy.

Adolescent↗
PubMed1985

7-Hydroxyguanine, a novel antimetabolite from a strain of Streptomyces purpurascens. I. Taxonomy of producing organism, fermentation, isolation and biological activity.

Strain A-347, an actinomycete isolated from a soil sample, was found to produce a new antimetabolite, 7-hydroxyguanine. The aerial mycelium formed spiral spore chains with spiny spore surface. The chemical composition of strain A-347 indicated that it was an actinomycete of cell wall Type I. From its morphological, cultural, physiological characteristics and direct comparison with the type culture, this strain was classified as Streptomyces purpurascens. 7-Hydroxyguanine was purified from the broth filtrate by ion exchange chromatography and crystallized from hot 2 M NH4OH. 7-Hydroxyguanine inhibited the growth of experimental tumors such as L1210 leukemia.

Animals↗
PubMed1985

7-Hydroxyguanine, a novel antimetabolite from a strain of Streptomyces purpurascens. II. Physico-chemical properties and structure determination.

The molecular formula of a new antimetabolite produced by Streptomyces purpurascens was determined to be C5H5N5O2 by elemental analysis, FD-MS and 13C NMR. Reduction of this antimetabolite with Raney nickel yielded guanine. The antimetabolite was distinguishable from known N-hydroxyguanines by comparison of their UV spectra. The structure of the antimetabolite was finally established to be 7-hydroxyguanine by X-ray crystallography.

Antimetabolites, Antineoplastic↗
PubMed1984

Testing of otolith function.

In order to investigate otolith function, horizontal eye displacement in total darkness during tilting laterally about body axis was examined in 23 normal subjects and 29 patients with vestibular lesions. The mean and standard deviation of this eye displacement in normal subjects were 18.9 + 6.1 degrees at 15 degrees of body-tilt. Thus, eye displacement below the lower tolerance limit of normal eye displacement at 15 degrees of body-tilt, that is, 8.8 degrees, was judged to be abnormal. Meanwhile, 12 cases or 41.4% of 29 patients with vestibular lesions showed abnormal eye displacement in this test. Especially in cases with positional vertigo and/or dizziness, the occurrence of abnormal results in this test (69%) was far higher compared with that of cases where vertigo and/or dizziness was not associated with postural changing (19%). Therefore, these abnormal results seem to be closely related to the disorder of otolith system.

Aged↗
PubMed1984

Rebound phenomenon in glycerol test.

The glycerol effect for endolymphatic hydrops is well known for an improvement in pure tone threshold three hours after glycerol administration. However, long-term effects of glycerol, i.e., longer than three hours after administration, are unknown. In this study, audiometric tests were administered during 10 hours following glycerol administration in order to determine the long-term effects of glycerol in cases of Meniere's disease, sudden deafness, and normal subjects. The following results were obtained; 1) The long-term effects of glycerol in the pure tone threshold were observed only in cases of Meniere's disease and were classified into the following four types: "descending type", "descending and ascending type", "ascending type" and "unchanged type". 2) The long-term effects, including rebound phenomenon, on hearing ability did not appear in cases of sudden deafness and normal subjects. 3) About 50% of patients with Meniere's disease showed rebound phenomenon on hearing ability and it was considered to be specific for Meniere's disease.

Audiometry↗
PubMed1984

[The interhemispheric trans-lamina terminalis approach to tumor of anterior part of the third ventricle].

In this paper the authors reported the operative approach to third ventricle tumors, mainly discussing bifrontal translamina terminalis approach. Our principle for approaching to the third ventricle tumors is as follows. If the tumor originates from the upper wall behind the Foramen of Monro, transcallosal approach should be adopted. And if the posterior wall is its origin, either transcallosal or infratentorial approach would be better. But if the tumor arises from the anterior half of the third ventricle, translamina terminalis approach should be adopted. In trans-lamina terminalis approach, at first bifrontal craniotomy should be performed. The interhemispheric space of the frontal lobes is dissected and lamina terminalis is cut, then the tumor can be reached. If necessary, the anterior communicating artery can be cut, and/or the optic chiasma can be cut for extending the operative field if the optic nerve is irreversibly damaged. There are several advantages in this approach. First, we can expose the main arteries and the operative filed is wide enough, making the operative procedure safe. Secondly, as comparing to the conventional approaches, any cortical incision or excision is unnecessary. By cutting the lamina terminalis which is usually thin and expanded as a result of hydrocephalus, even a large tumor can be removed. Also lethal complication is avoidable, because this approach has less possibility to damage the lateral wall of the third ventricle. This approach can be applied not only to the tumor but also to AVM or giant aneurysm adjacent to the third ventricle.

Adult↗
PubMed1983

Female puberty rites: reconsideration and speculation.

By using the odd-numbered Murdock-White SCCS societies, Brown's three hypotheses on female puberty rites were tested. Only matrilocal/ambilocal residence was significantly associated with female puberty rites. But after an adjustment for data quality control, even this relationship became insignificant. Female physiology as symbolized by menstruation is suggested as a better predictor for female puberty rites.

Adolescent↗