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Biomedical subjects

M Masaki

Publications and source records attributed to M Masaki.

At least 73 records · Page 4Linked to original sources

A human B-cell line (BES-1) forming rosettes with sheep erythrocytes, producing Forssman antibody, and phagocytizing sheep erythrocytes.

A lymphoid cell line, designated BES-1, belonging to "lymphoblastoid cell lines with B-cell properties (B-LCL)" and derived from some normal B lymphocytes, was established in an attempt at primary culture of peripheral blood from a patient with acute myelogenous leukemia (AML). BES-1 cells unexpectedly formed rosettes with sheep erythrocytes (SRBC), which are usually a T-cell marker, and phagocytized SRBC. Subsequent study indicated that BES-1 cells produce antibody specific to Forssman (F) antigen, but not to Paul-Bunnell (P-B) or Hanganutzin-Deicher (H-D) antigen.

Adult↗

Reduction of experimentally produced acute myocardial infarction size by a new synthetic inhibitor, NCO-700, against calcium-activated neutral protease.

Calcium-activated neutral protease (CANP) might be involved in the irreversible degradation of myocardial proteins in the ischemic region, leading to the loss of contractility. The new compound, NCO-700, and its analogues were synthetized against CANP. Among these analogues, NCO-700 was the most potent to reduce the size of acute myocardial infarction, which was produced by coronary artery ligation in rabbits, in vivo, although it showed less powerful action to inhibit CANP activity in vitro. The new reagent, NCO-700 might be promising to reduce acute myocardial infarction size and beneficial for the clinical studies, because it had no action to reduce cardiac muscle contractility, compared with beta antagonist or calcium-channel blockades.

Animals↗

Dynamic characteristics of the otolithic oculomotor system.

Vertical eye tracking test, up-down test, and running test in the dark and light were carried out to obtain Bode plots of transfer function of the opto-oculomotor, otolithic oculomotor, and opto-otolithic oculomotor systems. 1. The gain and phase of the opto-oculomotor system obtained from the vertical eye tracking test were flat in a frequency range of 0.3 to 1.0 Hz. 2. During the up-down test in the dark, the gain of the otolithic oculomotor system linearly increased at the rate of 20 dB/decade with an increase of frequency from 0.7 to 5 Hz. 3. During the up-down test in the light, the gain and phase were flat in a frequency range of 0.3 to 2.5 Hz. 4. The transfer function calculated with vertical head acceleration as input and vertical eye movement as output in the running test in the dark was similar to that in the light. The gain linearly decreased at the rate of 40 dB/decade with increase of frequency from 0.3 to 3.0 Hz. During running, eye displacement is almost in proportion to the head displacement in both dark and light. In daily, active movement such as running, eye movement proportional to head displacement appears without collaborative action of the opto-oculomotor system. 5. All five patients with bilateral loss of labyrinthine excitability exhibited a similar opto-oculomotor response to that of normal subjects. Three of the five patients did not show any eye movement corresponding to head movement in the up-down test in the dark. However, two patients showed a periodic eye movement in the same test, indicating dispersion of the gain and phase values. 6. These patients exhibited a rhythmic eye movement corresponding to head movement in the running test in the dark and light. However, values of gain and phase obtained in both tests were cultured. The variations in gain obtained from the running test in the light were observed in frequency ranges above and below 1 Hz.

Adult↗

Studies on Paul-Bunnel (P-B) antigen-antibody system. I. Two distinct P-B antigens.

The multiple nature of heterophile, Paul-Bunnel (P-B) antigen has been suggested by our previous studies as well as those of others. In the present study, two distinct antigens of P-B specificity were defined by means of hemagglutination and immunodiffusion tests in agarose gel; one antigen (BS) was shared by bovine (BRBC) and sheep red blood cells (SRBC) and another antigen (B) was limited to BRBC. Both anti-BS and anti-B antibodies were shown to be present in sera of 106 patients with infectious mono-nucleosis (IM) whereas they were virtually absent from the sera of the vast majority of patients with diseases other than IM and normal sera. Absorption and agglutination inhibition tests demonstrated the presence of BS and B antigens on horse erythrocytes. Goat erythrocytes were also shown to possess BS antigen, however, B antigen was found on erythrocytes of some but not all individual goats. By means of the previously established procedure, BS antigen was extracted from stromata of BRBC, SRBC and erythrocytes of horse and goat, and B antigen from BRBC and erythrocytes of some goats. BS and B antigens were also extracted from bovine lymphocytes and murine thymus and spleen tissues but not murine erythrocytes.

Absorption↗

Mortality and survival for Down syndrome in Japan.

Mortality and survival data for 1,052 Japanese patients with Down syndrome who were born between 1966 and 1975 were analyzed. The survival rate at age 10 was estimated to be about 86%. Mortality in each age group for Down syndrome was elevated over that of the general population. In the survival rate at age 10, there was no significant difference between males and females, but the difference between cases with and without congenital heart disease was highly significant. Using data from this study-for mortality up to age 10-and from the study of institutionalized cases for mortality over age 10, a hypothetical life table was constructed; it shows that the life expectancy at birth for cases with Down syndrome is nearly 50 years.

Adolescent↗

Studies on Paul-Bunnell (P-B) antigen-antibody system. II. P-B antigens in extracts of lymphoma-leukemia spleens and pathologic sera.

Preparations obtained by the chloroform-methanol extraction procedure from spleen tissues of patients with Hodgkin's disease, lymphomas, and leukemias, as well as from peripheral blood buffy coat of infectious mononucleosis (IM) patients were studied for the presence of 2 Paul-Bunnell (P-B) antigens; BS antigen shared by bovine red blood cells (BRBC) and sheep red blood cells (SRBC) and another, B antigen characteristic for BRBC. Both BS and B antigens were demonstrated by means of agglutination inhibition tests in over 40% of these extracts. None of the extracts from spleens, tonsils, and buffy coat of apparently normal human beings contained these antigens. P-B antigens of lymphoma-leukemia extracts were further purified by DEAE-Sephadex column chromatography. The purified fractions of some of these spleen extracts formed a precipitation line with IM sera, which merged into a reaction of identity with the lines formed by P-B antigens of BRBC. In studying various pathologic sera, B antigen was detected in sera of 28% of lymphoma-leukemia patients, 15% of patients with carcinomas of internal organs, and 3% of patients with systemic lupus erythematosus. On the other hand, BS antigen was found in only 3% of lymphoma-leukemia sera. These results confirmed our previous observations and indicated that both BS and B antigens are expressed as neoantigens on the patient's spleen cells as a result of pathologic processes in lymphoreticular malignancies.

Agglutination Tests↗