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Biomedical subjects

O Tanaka

Publications and source records attributed to O Tanaka.

At least 307 records · Page 17Linked to original sources
PubMed1982

Superficial spreading carcinoma of the esophagus.

Superficial spreading type of carcinoma of the esophagus was defined as lesions with intramucosal extension of carcinoma 20 mm or more from the main lesion. Eleven (6.1%) of 179 cases were thus selected for this investigation. These cases were further divided into two groups: Group A, consisting of four cases (2.2%) with the main lesion confined to the submucosa, representing a relatively early stage; and Group B, consisting of seven cases (3.9%) with the main lesion invading the muscular layer or deeper. One of the most characteristic features in the four cases belonging to Group A was an unexpectedly high incidence of lymphatic permeation and lymph node metastases leading to a poor prognosis. Another feature that may be important, particularly for surgeons performing esophagectomy, was the difficulty in deciding the proximal resection line of the esophagus because the boundaries between involved and uninvolved portions were frequently indistinguishable in this particular pathologic entity, not only in Group A but in Group B.

Aged↗
PubMed1982

Purification and properties of glucosyltransferase responsible for water-insoluble glucan synthesis from Streptococcus mutans.

A glucosyltransferase responsible for water-insoluble glucan synthesis was purified from the culture fluids of Streptococcus mutans 6715-15 strain by column chromatography on Toyopearl HW-60 and subsequently on hydroxyapatite. The enzyme preparation gave a single band on analysis by polyacrylamide gel electrophoresis. The pH dependency of the activity showed two optimal peaks at 5.8 and 7.3 and the Km values for sucrose were 1.4 and 3.3 mM at the respective optimal pHs. The molecular weight determined by sodium dodecyl sulfate gel electrophoresis was 180,000. Although the enzyme scarcely synthesized water-insoluble and water-soluble glucans from sucrose, water-insoluble glucan formed from sucrose in the presence of dextran T10 consisted of over 93% alpha-1, 3-glucosidic linkage. Analysis of the structure of water-insoluble glucan indicated that the enzyme catalyzed the formation of branch points in alpha-1,6-glucan (dextran) and transferred the glucosyl moiety of sucrose to the C-3 position of the branching glucose residue of dextran. Since this enzyme has not yet been registered, we named it mutansynthetase (EC 2.4.1.?).

Chemical Phenomena↗
PubMed1982

[Hemodynamic effects of a transdermal formulation of isosorbide dinitrate and its pharmacokinetics in conscious dogs].

Transdermal application of isosorbide dinitrate (ISDN) in the form of a tape (ISDN-Tape) to conscious dogs, in a dose of 40 mg/dog, caused a slow decrease in pulse pressure. The maximum effect was obtained 12 hour after application. The pulse pressure was still under the initial level even after 48 hours of application. In contrast, a sustained-release tablet of ISDN (ISDN-SR-Tablet), given in a dose of 40 mg/dog, significantly decreased the pulse pressure of conscious dogs by reducing systolic pressure and slightly elevating diastolic pressure. The plasma concentrations of ISDN and its two metabolites, isosorbide 2-mononitrate (2-ISMN) and isosorbide 5-mononitrate (5-ISMN), were measured by gas chromatography after application of ISDN-Tape or ISDN-SR-Tablets. The time course pattern of the plasma concentration of ISDN after application of the both preparations ran quite parallel with their decreasing effect on the pulse pressure. After application of the ISDN-Tape, the plasma concentration of ISDN was maintained at a higher level than after the application of the ISDN-SR-Tablet. The maximum plasma concentrations of the two metabolites, however, were considerably lower in the case of the ISDN-Tape than in the case of the ISDN-SR-Tablet. These results were ascribed to the fact that ISDN given through the transdermal route, in contrast to that given by the peroral route, does not undergo the first-pass effect in the liver. It was concluded that the transdermal dosage form of ISDN, which possesses a more prolonged pharmacologic effect than the oral dosage form, may be useful in the prevention and cure of angina pectoris.

Administration, Topical↗
PubMed1981

Pharmacological sequential trials for the fractionation of components with hypoglycemic activity in alloxan diabetic mice from ginseng radix.

Three methods of fractionation of ginseng radix (Panax ginseng C.A. MEYER) components for a survey of hypoglycemic principle in alloxan diabetic mice were conducted and three groups of hypoglycemic principle in alloxan diabetic mice were conducted and three groups of components tested; fat-soluble components, ginseng saponins and a third component with hypoglycemic activity. Pharmacological sequential trials of the fractionation yielded a most active fraction which was about 100-fold more effective than the original water-soluble extract of the ginseng radix. The ED50 value was 0.4 mg/kg in lowering the blood level of glucose in alloxan diabetic mice. It was demonstrated that some ginseng fractions inhibited epinephrine-induced transient hyperglycemia in mice, increased glycogen content in rat liver, decreased the blood level of acetone bodies in alloxan diabetic mice, and inhibited the release of free fatty acid from rat epididymal fat pad. The results showed that hypoglycemic components existed in a new component of ginseng radix which is different from saponin.

Animals↗
PubMed1981

Effects of hypoglycemic components in ginseng radix on blood insulin level in alloxan diabetic mice and on insulin release from perfused rat pancreas.

Some fractions extracted from ginseng radix (HAKUSAN) caused hypoglycemic effect on alloxan diabetic mice. The effect was abolished by the i.v. injection of antisera against bovine insulin. The same doses of the ginseng fraction (10--50 mg/kg) produced an increase in the blood insulin level in alloxan diabetic mice. Normal mice loaded i.p. with glucose (2 g/kg or more) showed also such an increase. Insulin release from perfused rat pancreases was stimulated by the ginseng fraction (0.2 mg/ml), but the potency was not stronger than that of the sulfonylureas. It was demonstrated that glucose-induced insulin release was marked in the presence of the ginseng fraction. Impaired insulin responses to glucose in alloxan diabetic rats were increased by the fraction (0.5 mg/ml) to or above the control responses in normal rats. The enhanced effect was observed also in the presence of 100 microgram/ml cycloheximide. These results indicate that some ginseng fractions stimulated insulin release, especially glucose-induced insulin release from pancreatic islets and thereby lowered the blood glucose level.

Animals↗
PubMed1980

Comparison of the Ability of Salicylic Acid and Ferricyanide to Induce Flowering in the Long-day Plant, Lemna Gibba G3.

Both salicylic acid and ferricyanide induce flowering in the long-day plant Lemna gibba L., strain G3 under 8- and 9-hour short days. In both cases the effect is daylength-dependent. Salicylic acid is ineffective on daylengths less than 8 hours and ferricyanide is ineffective on daylengths less than 5 hours. When both substances are given together a striking synergistic interaction is observed, and some flowering is obtained on daylengths as short as 3 hours. However, even with the optimal combinations the flower-inducing effect remains daylength-dependent.Flowering of L. gibba G3 is inhibited under continuous light in both half-strength Hutner's medium (0.5 H), which contains 1.25 millimolar ammonium, and in ammonium-free half-strength Hutner's medium (NH(4) (+)-free 0.5 H). Salicylic acid is able to reverse the inhibition substantially in 0.5 H medium and to cause complete reversal in NH(4) (+)-free 0.5 H medium. By contrast, ferricyanide has no effect in 0.5 H medium and causes only a small reversal in NH(4) (+)-free 0.5 H medium. Flowering of L. gibba G3 is also inhibited under continuous light by copper. This inhibition is largely reversed by salicylic acid but ferricyanide has no effect.

Journal Article↗