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Biomedical subjects

K Sugihara

Publications and source records attributed to K Sugihara.

At least 253 records · Page 14Linked to original sources
PubMed1984

Scanning electron microscopic study of odontogenic keratocysts.

Three odontogenic keratocysts were examined with a scanning electron microscope (SEM) on their surface cells, prickle cells, basal cells, and the epithelial-connective tissue interface. The microridges of the surface cells had a short, discontinuous, branched or beaded appearance. Intracellularly, the flattened keratinized cells formed a network consisting of delicate microfilaments. The prickle cells had numerous cytoplasmic projections and a large round nucleus that occupied most of the cytoplasm. The basal cells had two types of cytoplasmic process and a large oval polarized nucleus. The epithelium and the lamina propria were connected by a fibrous and fibrillar network.

Adolescent↗
PubMed1984

Diffusion coefficient of 36Cl in silver chloride.

Diffusion coefficient of 36Cl in silver chloride was revealed to be about 1 x 10(-10)-4 x 10(-11) cm2 . s-1 in the range of 400 degrees C-200 degrees C by means of radioactive tracer measurements. Activation energy for diffusion was calculated about 0.13 eV. These results were different from those obtained by Maurer and Compton.

Chlorine↗
PubMed1984

[Gastrinoma: diagnosis and management of Zollinger-Ellison syndrome].

Diagnosis and management of Zollinger-Ellison syndrome (ZES) do not appear to be established even today. In the present study, 143 cases of ZES (including 12 of author's experience) were collected from Japanese literature and analyzed, and diagnosis and management were discussed. (1) Although 43% of patients showed high gastrin level (greater than or equal to 500pg/ml), it is worth to be stressed that gastrin level was below 300pg/ml in 29% of patients. (2) Secretin provocation test was essential for diagnosis and particularly useful for detecting ZES with low gastrin level. (3) Angiography and/or blood samplings of PTPC were widely used for localizing gastrinoma but the informations thus obtained were not always of help for complete removal of tumors since malignant or multiple gastrinomas were frequent. (4) An aim of management for ZES consists of complete removal of tumor but it is not always feasible. Therefore, removal of target organ (total gastrectomy) should be routinely added for long-term cure. (5) Value of chemical gastrectomy (H2-receptor antagonist) is still a matter of pros and cons but substantial value of this drug should be considered adjunct to surgery.

Gastrectomy↗
PubMed1983

Motility study in right sided diverticular disease of the colon.

Intraluminal pressure in the ascending colon of 13 patients with right sided diverticular disease and 10 of normal subjects was studied with catheter-tip transducer inserted through colonoscopes. In the resting state the colonic motility index of patients with diverticular disease was greater than that of the controls. After intravenous injection of neostigmine methylsulphate higher pressure waves were more frequently observed in patients with diverticular disease than the controls, and the colonic motility index of patients was much greater than that of the controls with statistical significance. From these observations it is suggested that high intraluminal pressure and the abnormal motility in the ascending colon plays an important role in the pathogenesis of right sided diverticular disease.

Adolescent↗
PubMed1983

Involvement of liver aldehyde oxidase in conversion of N-hydroxyurethane to urethane.

The present study provides the evidence that liver aldehyde oxidase in the presence of its electron donors can catalyze the reduction of N-hydroxyurethane to urethane under anaerobic conditions. Guinea pig liver 9000 X g supernatant and cytosol, but not liver microsomes, exhibited N-hydroxyurethane reductase activity in the presence of acetaldehyde or 2-hydroxypyrimidine. The cytosolic enzyme was precipitated with ammonium sulfate between 30 and 45% ammonium sulfate saturation. The N-hydroxyurethane reductase and aldehyde oxidase activities of the precipitate were similarly susceptible to inhibition by a variety of chemicals. When the precipitate was chromatographed on a DEAE-cellulose column, the elution peak position of N-hydroxyurethane reductase was entirely identical with that of aldehyde oxidase. Furthermore, purified rabbit liver aldehyde oxidase also exhibited a significant N-hydroxyurethane reductase activity in the presence of acetaldehyde or 2-hydroxypyrimidine.

Aldehyde Oxidase↗
PubMed1982

Classification of impossible objects.

A mathematical scheme is proposed for the classification of impossible objects. Impossible objects are usually defined from a psychological point of view as mental images of 'solid objects' which cannot exist in a real three-dimensional world. From the mathematical point of view, however, various kinds of impossibility can be observed in such objects, and they are classified according to the kinds of impossibility they possess. Since impossible objects are treated in a purely mathematical way, the results afford a powerful basis for the psychological study of human visual perception of impossible objects. Several psychological problems arising from the present results are also discussed.

Form Perception↗
PubMed1982

Metabolism of N-hydroxyurethane by guinea pig liver preparations.

The present study demonstrated the metabolism of N-hydroxyurethane by cell-free preparations, i.e., 9000 X g supernatant, cytosol and microsomes, from guinea pig livers. Under anaerobic conditions, the metabolizing activities of these preparations were enhanced markedly by addition of both an NADPH- or NADH-generating system and FAD. When the 30-45% ammonium sulfate fraction from liver cytosol was combined with liver microsomes or milk xanthine oxidase, the metabolic reaction of N-hydroxyurethane proceeded to a greater extent. Thin-layer chromatographic examination showed that urethane was only a metabolite formed from N-hydroxyurethane by these preparations.

Animals↗
PubMed1979

Linking of N4-aminocytosine to glutathione by use of bromopyruvate.

N4-Aminocytosine reacted with acetone and acetaldehyde to form hydrazones that were readily revertible to the parent compound. With pyruvate, in contrast, it formed a stable hydrazone. By use of bromopyruvate, N4-aminocytosine was linked to glutathione.

Chemistry, Organic↗