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Biomedical subjects

T Maeda

Publications and source records attributed to T Maeda.

At least 1,297 records · Page 72Linked to original sources
PubMed1984

[Two-dimensional echocardiographic evaluation of left atrial shape and size].

We investigated the influence of the miscellaneous structures surrounding the left atrium on left atrial shape and examined the feasibility and problems in evaluating its size using the anteroposterior dimension of the M-mode echocardiogram. Using two-dimensional echocardiography, left atrial anteroposterior short-axis dimension (S), long-axis dimension (L), transverse-axis dimension (T) which cross perpendicularly one another, and area in the long-axis section (AREA) were measured in 84 subjects. The left atrial size was defined as AREA X T. The population of this study consisted of 24 subjects without heart disease, 24 with mitral valve disease and 34 with miscellaneous heart diseases other than mitral valve disease. Some of them were associated with the thin chest, chest deformity by thoracoplasty or the markedly dilatated right atrium. In subjects with the thin chest the left atrium was compressed in the anterior and posterior directions, in patients who underwent thoracoplasty it was elongated in the cranial and caudal directions, and in those with the markedly dilatated right atrium it was compressed in the right and left directions. It can be speculated that surrounding structures have some direct effects on left atrial dynamics. As left atrial size increased, these three dimensions (S, L and T) increased disproportionally. Because the contribution of each dimension to the left atrial volume change is proportional to the ratio of dimensional change and S has the largest ratio, S contributed to left atrial volume change more than the others. That is the reason that left atrial volume was not proportional to S or S3. The relationship between S and AREA during one cardiac systole was almost linear in individual studies. The slope in the S-AREA relation, however, was greater in the cases with a larger value of S. Therefore, when the extent of the change in S is used as an index of atrial volume change, it should be normalized by S. Because the left atrium expanded in any directions, either S or other dimensions reflected its size. In cases with the distorted left atrium, however, evaluation of left atrial size by the use of a single dimension alone was inadequate.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1984

[Regional cerebral blood flow and neurological conditions in patients with surgically treated hypertensive intracerebral hemorrhage].

Regional cerebral blood flow (rCBF) was measured in 49 patients with surgically treated hypertensive intracerebral hemorrhage (putaminal hemorrhage 27: thalamic hemorrhage 22). The hematoma evacuation was performed within 14 days after the hemorrhage. For the measurement of rCBF, the intracarotid xenon-133 injection method was used. Two rCBF studies were performed on all patients, the first giving the resting state of the brain perfusion, the second after Prostaglandin E1 (PGE) administration into the internal carotid artery 10 minute after the first study. (PGE was administered 10 micrograms in 5 minutes.) In all patients blood pressure and arterial carbon dioxide tension were examined before and after each CBF study. The evaluation was made by comparing the rCBF maps obtained before and after PGE administration. (A rate of rCBF increase was calculated by dividing each rCBF value obtained after PGE administration by each rCBF value obtained before PGE administration (control value), and the ratio was multiplied by 100.) The PGE-induced reaction patterns were divided into four; the first is the diffuse increase pattern, characterized by a diffuse increase of rCBF values in the hematoma-evacuated area and the surrounding brain; the second is the diffuse decrease pattern, characterized by a global decrease of rCBF values in the hematoma-evacuated area and the surrounding brain; the third is the pattern of intracerebral steal effect, characterized by a decrease of rCBF in the hematoma-evacuated area and an increase of rCBF values in the surrounding brain; and the fourth is the pattern of inverse cerebral steal effect, characterized by an increase of rCBF in the hematoma-evacuated area and a decrease of rCBF in the surrounding brain.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

A simple and rapid method for the preparation of plasma membranes.

A simple and rapid method for preparing plasma membranes from isolated cells or tissues is described. The membranes were characterised (a) biochemically by an analysis of specific marker enzymes, (b) by quantitation of cell surface receptors, and (c) immunologically by their ability to elicit specific allogeneic responses from cytotoxic T cells in secondary in vitro stimulations. Based on both biochemical and immunologic criteria, plasma membranes prepared by the method described here are of equal or greater 'purity' compared to those prepared by two other methods that are most widely used to date and the yields are several-fold higher.

Animals↗