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S Asakura

Publications and source records attributed to S Asakura.

At least 109 records · Page 6Linked to original sources
PubMed1987

Induction of a novel Ca2+-dependent protease in preneoplastic and neoplastic liver tissues during rat liver carcinogenesis.

The activity of a novel Ca2+-dependent protease in preneoplastic and neoplastic tissues of male Fisher 344 rat liver was examined during experimental liver carcinogenesis. This protease activity is significantly high in hyperplastic nodules and hepatocellular carcinomas which were induced by the method of Solt and Farber. Taken together with our previous report on the promoter-specific induction of this protease, the results suggest the possible importance of this protease in the promotion stage of liver carcinogenesis.

Animals↗
PubMed1987

Declining mortality from ischemic heart disease and changes in coronary risk factors in Japan, 1956-1980.

Mortality from ischemic heart disease has declined in Japan since 1970. This paper addresses the declining mortality from ischemic heart disease and the possible contributing factors for 1956-1980. Mortality figures were obtained from Vital Statistics reports by the Ministry of Health and Welfare in Japan. National trends in blood pressure levels, prevalence of hypertension, Keys' lipid factor phi instead of the serum cholesterol level, and body mass index were obtained from the National Nutrition Survey which is carried out annually from random samples in Japan. The smoking rate which was obtained from other national surveys was also reviewed for this purpose. The age-adjusted (30-69 years) mortality from ischemic heart disease declined by 24% and 37% for men and women, respectively, between 1968 and 1978. It seemed that the decline in blood pressure levels and in the prevalence of hypertension and the increasing treatment rate for cardiovascular disease might contribute to the declining mortality from ischemic heart disease. The decline in cigarette smoking may, in part, also play a role. On the other hand, the increase in intake of lipids which resulted in Keys' lipid factor phi was compatible with the increase in mortality from ischemic heart disease during 1956-1970. The experience in Japan shows that the treatment of hypertension or the lowering of blood pressure and the recommendation to stop smoking help to prevent ischemic heart disease.

Adult↗
PubMed1987

Tropomyosin reverses cross-linking of F-actin with microtubule-associated protein-2.

Brain microtubule-associated protein 2 (MAP2) is known to cross-link muscle F-actin in vitro into a gel or discrete bundles of actin filaments. Previous reports indicate that this cross-linking reverses in the presence of millimolar ATP, while MAP2 molecules remain attached along single filaments of F-actin. Therefore, it is likely that the actin filament has two sets of surface areas with ATP-sensitive and insensitive affinities for MAP2. Using purified preparations of brain MAP2 and skeletal muscle F-actin and tropomyosin, we have studied the effects of tropomyosin on the MAP2-actin interaction by dark-field light microscopy, electron microscopy, sedimentation assay, and low shear viscometry. The results show that cross-linking of F-actin with MAP2 reverses upon addition of a stoichiometric amount of tropomyosin, although MAP2 remains bound to F-actin complex with tropomyosin. The ternary complex does not dissociate noticeably when exposed to a millimolar concentration of ATP. On the basis of these findings, it is concluded that ATP-insensitive MAP2-binding of F-actin is not sterically blocked by tropomyosin, while the ATP-sensitive binding is blocked by it.

Actins↗
PubMed1987

Localization and stoichiometry of hook-associated proteins within Salmonella typhimurium flagella.

The localization of hook-associated proteins (HAP1, HAP2, and HAP3) in Salmonella typhimurium flagella was studied by using specific antibodies together with a second antibody conjugated with colloidal gold. HAP1 and HAP3 were localized at the hook-filament junction, as has been suggested previously. HAP2, however, was localized at the filament tip. This finding supports the idea that HAP2 acts to induce polymerization of endogenous flagellin at the filament tip, and HAP1 and HAP3 are junction proteins to connect hook with filament. Analysis of the protein composition of short flagella from a mutant indicated that a single flagellum contains about 10 to 20 HAP1, 10 to 20 HAP2, and 10 to 40 HAP3 molecules.

Antibodies↗
PubMed1987

[A case of inverted papilloma of the ureter with malignant findings].

A 70-year-old female with inverted papilloma of the ureter is presented. She was hospitalized because of asymptomatic macrohematuria. Excretory urography and retrograde pyelography demonstrated a filling defect with smooth contour at the mid-portion of the right ureter. Abdominal computer tomographic (CT) scan showed mass lesion (CT number 41) at the same portion as the filling defect. She was diagnosed as having an ureteral tumor and right nephroureterectomy was performed. The gross specimen contained a 24 X 12 mm, polypoid, pedunculated and smooth-surfaced tumor. Pathological diagnosis was inverted papilloma. However, microscopic examination revealed a malignant finding corresponding to transitional cell carcinoma grade 1. From the Japanese and foreign literature, 25 cases of ureteral inverted papilloma were collected and are reviewed. Clinical and pathological features are discussed.

Aged↗
PubMed1987

The effect of reduced alcohol consumption on blood pressure: a randomised, controlled, single blind study.

A randomised, controlled, single blind trial was conducted in office workers with mild hypertension (systolic blood pressure (SBP) 140 to 180 mmHg, diastolic blood pressure (DBP) 90 to 110 mmHg) to determine the effect of decreasing alcohol consumption. After a baseline examination, 50 male volunteers aged 30 to 59 were randomised to two groups. Group A were told to abstain from or reduce alcohol consumption for two weeks, while group B were instructed to maintain their usual alcohol consumption. Complete records were obtained on 49 subjects. The daily alcohol consumption of groups A and B at baseline was similar, i.e. 71.9 ml and 72.5 ml of ethanol, respectively, and changed to 16.1 ml and 62.9 ml, respectively, during the experiment. After two weeks, group A were asked to resume their normal consumption whilst group B were asked to reduce or abstain (phase II). However in view of a treatment period interaction, statistical analysis was confined to phase I. During phase I, group A, whose alcohol consumption had reduced, showed decreases of 5.8 and 7.1 mmHg in SBP during the the first and second weeks, respectively. In group B, these decreases were only 0.6 and 1.9 mmHg, respectively. The difference between the falls in SBP in groups A and B was significant (P = 0.005) as judged by analysis of variance. The DBP also decreased, but there was no significant difference between the decreases in the two groups. Changes in gamma-glutamyl-transpeptidase, a biochemical marker of alcohol consumption, from the initial values to the end of phase I were significantly different in groups A and B.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Directional movement of F-actin in vitro.

By a fluorescence microscopic method for visualizing single filaments of F-actin in solutions, we have investigated movement of F-actin in a motility system in vitro. It was found that, when F-actin and myosin were mixed in the presence of Mg2+-ATP under appropriate conditions, individual F-actin filaments continued moving in different directions, but in parallel to their length, for a long period of time. The actin filaments did not reverse their direction of movement and had a distribution of speed with the maximum at about 5 micron per second (at 27 degrees C).

Actins↗
PubMed1986

[Application of Testsimplets for classification of sperm morphology].

Testsimplets is a pre-stained, ready-to-use slides for differential blood cell counts. We have been using this Testsimplets slide to classify sperm morphology since 1978. Its characteristics is that it is very easy to prepare specimens quickly and we can see sperm morphology clearly for the classification of the sperm. We regard this Testsimplets slide as a supravital staining. The disadvantage is that we can not preserve specimens for more than 24 hrs. Extensive use of the Testsimplets slide is a useful method for the classification of sperm morphology in the infertility clinic.

Benzoxazines↗
PubMed1985

"Cap" on the tip of Salmonella flagella.

Flagellar filaments isolated intact from a Salmonella short-flagella mutant are unable to serve as nuclei for flagellin polymerization in vitro, whereas the filaments reconstructed in vitro from the mutant flagellin are able to do so. The inability of intact flagella to nucleate flagellin polymerization appears to be common to wild-type bacteria and thus suggests that the tip of intact flagella are generally inactivated or capped in vivo. Careful observations of the tips of intact flagella and reconstructed flagellar filaments of a wild-type species have revealed marked difference between them: the intact flagella usually have blunt ends, whereas reconstructed filaments have concave, "fish-tail" ends. Moreover, a thin structure is often observed attaching to the very end of the intact flagella. We suspect that this "capping" structure is essential to the elongation mechanism of flagellar filaments.

Flagella↗