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口腔内Heparinase産生性BacteroidesのEndotoxinの生物学的活性
Get PDFapplication/pdfA possible role of oral Heparinase-producing Bacteroides which resembles to Bacteroides oralis in the character in the etiology of periodontal disease has been emphasized by the authors. This is mainly based on the facts that they possessed heparinase and remarkably increase in number in the local samples of experimental mixed infection by human dental plaque following serial transfer. The present study dealed with the extraction and characterization of the endotoxin from the cells of the Bacteroides. Three strains which differed from each other in the heparinase activity were grown in Trypticase broth for 5 days anaerobically at 37℃. Harvested cells were washed three times with acetone, dried under CaCl_2 and subjected to extraction. Endotoxin were extracted by phenol-water (1:1) according to Westphal method with some modifications. The recoveries of preparation were 7～17% by dry weight basis. Preparations were whitish powder and water-soluble. Preparations pyrogenicity, Shwartzman reactive activity and cytotoxic activity of the endotoxin were demonstrated. The higher endotoxic activity was observed in the preparation with higher recovery. In the Shwartzman reaction, a positive correlation was found between preparatory activity of the endotoxin and the heparinase activity of the strain.journal articl
鋳造精度に関する研究 : その5 リング内の埋没材の膨張傾向の均一化について
Get PDFapplication/pdfThis report is described on the factors affecting to the distortion of the castings. They are thought to be setting expansion or hygroscopic expansion, thermal expansion of the investment, casting shrinkage of the alloys and others. Authers had studied on amounts of the distortion caused by the factors. Oblong wax patterns, having 30mm width, 20mm hight and 1.5mm thickness, indented by the guage line, were prepared and embeded in casting rings. The castings was produced with three kinds of alloys having various casting shrinkage and was casted in the investment mold heating at 600℃ or holding at room temperature. The effect of hygroscopic expansion was compared between the use of wet asbestos linning and the use of Kaowool linning that inhibited it. Results obtained were as follows. 1. Most of castings were distorted like the beer barrel. 2. The distortion of the castings was founded on the defferences of each casting shrinkage due to its situation in the ring. 3. The setting expansion was caused from 0.5% to 0.8% for longitudinal direction, but it was about 0.35% for lateral one. 4. The increases due to the hygroscopic expansion, were 0.4% for longitudinal direction and 0.3% for lateral one. 5. The thermal expansion was brought about 0.98% for longitudinal direction and 0.65% for lateral one. 6. The thermal expansion of investments in the ring was not uniformly and it was increased near the bottom of the ring. 7. Use of Kaowool sheet for the linning of the ring, was more effective to avoid the distortion than that of wet asbestos ribbon.journal articl
カエル舌粘膜におけるカルシウムイオンの受動および能動輸送
Get PDFapplication/pdfThe movement of Ca ions across the mucosa of the frog tongue was measured by means of radioisotope, ^Ca. The results obtained were as follows; 1. Ca uptake was inhibited by NaCl and NaSCN and its rate reduced to approximately 10% of the control by adding 1M NaCl. 2. Ca uptake was inhibited by some chemicals such as 2, 4-dinitrophenol, ruthenium red and sodium lauryl sulfate, but its rate did not reduce to less than one third of the control. 3. Both Ca uptake and Ca release were inhibited by cooling, but their rates did not reduce to less than one third of the control. These results suggest that there are passive and active transport of Ca ions across the mucosa of the frog tongue.journal articl
口腔内Propionibacterium acnesのChondroitin Sulfataseに関する研究
Get PDFapplication/pdfChondroitin sulfate splitting activity was demonstrated by 10 strains of Propionibacterium acnes isolated from gingival pocket's samples exhibiting periodontal disease and by one strain isolated from the pus sample of experimetal mixed infection in guinea pig induced by human dental plaque. The activity was observed in both cells and culture supernatant. From the daily change in the activity of these samples the factor was found to liberate from the cell quite easily. The factor was non-dializable. Heating at 70℃ for 10 minutes was found to inactivate completely the factor. Reducing group of chondroitin sulfate increased following the decreasing of the substrate. The highest activity was observed at pH between 5.5 and 6.0. Based on the fact that Propionibacerium acnes was an essential member of the trio for the mixed infection in the animal, a possible role of the chondroitin sulfatase of the speices in the etiology of the periodontal disease was discussed.journal articl
