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Biomedical subjects

F Suzuki

Publications and source records attributed to F Suzuki.

At least 613 records · Page 34Linked to original sources
PubMed1978

The organization of testicular interstitial tissue and changes in the fine structure of the Leydig cells of European moles (Talpa europaea) throughout the year.

Seasonal changes of the testicular interstitial tissue were studied by electron microscopy. During the breeding season in spring, clusters of Leydig cells are surrounded by wide lymphatic sinusoids. In sexually quiescent moles, these sinusoids collapse, and the abundant Leydig cells become closely packed and occupy most of the testis. During sexual activity, the Leydig cells contain abundant smooth endoplasmic reticulum (SER), mitochondria with tubular cristae, and lipid droplets. Some areas of the cytoplasm are occupied exclusively by tubular SER, arranged in parallel. During regression the SER appears tortuous, and large lipid droplets are found in the cytoplasm, although these gradually become smaller. During the long period of sexual quiescence, the size and abundance of Leydig cells and the appearance of SER, lipid droplets and mitochondria were similar to those observed during sexual activity.

Animals↗
PubMed1978

Isolation and characterization of a new antitumor polysaccharide, KS-2, extracted from culture mycelia of Lentinus edodes.

A new antitumor and antiviral substance, KS-2, was prepared by ethanol precipitation of the hot water extract of culture mycelia of Lentinus edodes KSLE 007. It was further purified by ECTEOLA-cellulose and Sephadex G-100 column chromatography based on the interferon-inducing activity. Its homogeneity was revealed by CsCl density gradient centrifugation, electrophoresis on cellulose acetate and Sephadex G-100 and ECTEOLA-cellulose column chromatography. KS-2 is mainly composed of alpha-linked mannose and contains a small amount of peptide which consists of serine, threonine and alanine with residual amounts of the other amino acids. The estimated molecular weight of KS-2 is between 6.0 X 10(4) and 9.5 X 10(4). KS-2 suppressed the growth of EHRLICH as well as Sarcoma-180 tumors in mice when given either orally or intraperitoneally. It is also capable of inducing an interferon in mice when dosed orally or intraperitoneally. The acute LD50 of KS-2 was found to be extremely low, more than 12,500 mg/kg when administered orally to mice.

Agaricales↗
PubMed1977

Effect of an interferon inducer, 9-methylstreptimidone, on influenza virus infection in mice.

The antiviral effect of 9-MS was examined in mice infected with mouse-adapted influenza A2 (H2N2) virus. Either a single or a continuous prophylactic administration of 9-MS protected mice from virus infection, and comparison of the minimal effective dose with the lethal dose gave a therapeutic index of approximately 60. When the treatment was started after infection, however, no antiviral effect was demonstrated. A potent virus-inhibitory factor was detected in the lung and serum after a single intraperitoneal administration of 9-MS in uninfected mice, and on the basis of chemical characteristics of this inhibitory factor, it was assumed to be an interferon. These results suggest that the protective activity of the antibiotic in mice is due to interferon induction.

Animals↗
PubMed1977

Repair of the sublethal and mutational damage induced by x-rays in Chinese hamster HAI cells in vitro.

The ability of Chinese hamster hai cells to repair damage related to cell death and mutational change induced by X-rays were examined by using a sensitive forward mutation system from prototrophic CH-hai Cl 23 cells to auxotrophs. The results obtained from the split dose experiments seem to suggest that Chinese hamster hai cells have the repair mechanisms for the sublethal and mutational damage induced by X-rays and that the repair mechanisms act in common for the repair of both cases of damage.

Cell Line↗
PubMed1977

Demonstration of bidirectional dual A-V nodal pathways in the same patient.

In a patient with documented paroxysmal junctional tachycardia (PJT) electrophysiologic studies were performed using an extrastimulus technique. At an A1-A2 interval of 360 msec, atrial extrastimulus revealed sudden prolongation of an A2-H2 interval from 370 to 540 msec and PJT ensued. This finding was consistent with antegrade dual A-V nodal pathways. On the other hand, at a V1-V2 interval of 540 msec, ventricular estrastimulus showed a jump in ventriculo-atrial (V-A) conduction time with evidence of delay in the A-V node from 285 to 565 msec and a ventricular echo followed. This finding was consistent with retrograde dual A-V nodal pathways. Mechanisms of bidirectional dual A-V nodal pathways are discussed.

Aged↗
PubMed1977

Paroxysmal supraventricular tachycardia with unusual induction. Concealed reentry or automaticity?

In a patient with documented paroxysmal supraventricular tachycardia, earlier atrial extrastimuli consistently induced His-ventricle (H-V) block and "atrioventricular junctional" beats, which were always followed by an echo or paroxysmal supraventricular tachycardia. In "atrioventricular junctional" beats, a V wave was preceded by an H deflection with the same intervals as that of the sinus beat. As for the underlying mechanism of paroxysmal supraventricular tachycardia, two possibilities were considered: (1) concealed atrioventricular nodal reentry, and (2) "triggered automaticity."

Adult↗
PubMed1977

Demonstration of two anomalous bypasses in concealed Wolff-Parkinson-White syndrome.

Two patients with a history of paroxysmal supraventricular tachycardia but no evidence of the Wolff-Parkinson-White syndrome in the conventional electrocardiograms were studied utilizing atrial and ventricular extrastimuli. The evidence obtained in these patients was consistent with a concealed Wolff-Parkinson-White syndrome. In one patient, ventricular extrastimuli revealed three different responses in the curve of ventriculoatrial conduction, depending upon the interval of stimulus. In the other patient, intracardiac recordings, including the left atrial potential, showed that paroxysmal supraventricular tachycardia was induced by an impulse via an anomalous bypass which diverged from the main bypass or stemmed independently from the left ventricle and was maintained by impulses via the main bypass which lay between the left ventricle and the left atrium. The mechanisms for initiation of the paroxysmal supraventricular tachycardia were discussed.

Adult↗
PubMed1977

Identification and properties of reactive sites in protein capable of binding carbon dioxide in a gas-solid phase system.

In order to identify the functional groups which really contribute to the carbon dioxide gas adsorption by proteins, epsilon-amino groups of lysine residues of egg albumin were chemically modified with trinitrobenzene sulfonic acid to various degrees. About 60% of the total amount of carbon dioxide gas absorbed by solid egg albumin diminished by complete modification. The amount of carbon dioxide gas adsorbed by lysozyme, its hydrolyzates and gelatin hydrolyzates depended upon the lysine content, arginine content and average molecular weight. The good correlation was obtained between the amount of carbon dioxide gas absorbed and the total of lysine and arginine content of them. The ability of carbon dioxide gas adsorption by alpha-amino group of amino acids and oligopeptides was found to be developed by the elongation of the peptide chain of glycine and other amino acid, by the removal of alpha-carboxyl group of histidine and tyrosine to corresponding amines and by the esterification of alpha-carboxyl group of leucine with p-nitrophenol. These results clearly indicate that CO2 binding sites in protein in the gas-solid phase system are epsilon-amino, alpha-amino and guanidinium groups.

Amino Acids↗