<ORIGINAL ARTICLE>Reduction of Exposure Dose from Dental Film Packs with Fluorecent Screen

P(論文)Dental film packs with fluorescent screens were made experimentally for the purpose of reducing the exposure dose and to conduct a quantitative analysis on the definition of radiographies taken with these materials. The type of screens were divided into (a) high resolutive type I, (b) high resolutive type II and (c) high sensitive type. The results obtained were as follows; (1) Compared with traditional dental films, the exposure dose could be decreased to 1/8.6 with high resolutive type I,1/14.9 with high resolutive type II and 1/55.8 with sensitive type. (2) In diagnosing, the definition with high resolutive type I and II were sufficeint in the case of routine examinations. The high sensitive type was inferior in resolution compared to high resolutive Type I and Type II. But this type was useful in the case of survaying without the necessity of high resolutive exposure, (3) Manufacturing costs of these materials are more expensive than the traditional ones, but should decrease in price when mass production can be carried out. (4) In the future, it will become necessary to stress the importance of decreasing the exposure dose since the image qualities are not improved to such a great extent.departmental bulletin pape

<原著>コットン・ペレット肉芽腫において見られた細胞内コラーゲン原線維の電子顕微鏡的観察

P(論文)細胞内コラーゲン原線維の検索のためにコットン・ペレット法を用いてラット背部に肉芽腫を発症させ電子顕微鏡を用いて観察をおこなった。その結果,細胞の小体内にコラーゲン原線維が認められるものが存在した。細胞内コラーゲン原線維は,その形態から2つのタイプが観察された。その1つは,コラーゲン原線維を含む小体内部が明調で,コラーゲン原線維の横紋構造が明らかに認められるもの。もう1つのタイプは,小体内が暗調で,コラーゲン原線維の横紋構造が不明瞭か,もしくは認められないもの。これらの所見は,細胞により取り込まれ,細胞内で消化をうける一連の過程で生じるものと思われ,またコラーゲン原線維を含む細胞は,その細胞小器官の検索から,特徴的な線維芽細胞の形態を備えていた。以上のことから,線維芽細胞の機能は,コラーゲン合成のみならず,コラーゲン線維の崩壊にも役割をはたしていることが示唆される。Intracellular collagen fibrils were detected by electron microscopy in experimental granulomas induced in the back of rats by cotton pellets. The banded intracellular collagen fibrils were ob-served in phagocytic vacuoles. Two types of collagen fibril-containing vacuoles were seen. In one type the vacuoles contained an electron-lucent material and the periodicity of the collagen fibrils was clearly seen. In the other type, the vacuoles contained an electron dense matrix and collagen fibrils were frequently not clearly evident. The cells that contained collagen fibrils had the features characteristic of fibroblasts actively engaged in collagen synthesis. These results suggest that these intracellular collagen fibrils had been phagocytosed by fibroblasts. It is proposed that fibroblasts have the ability not only for the biosynthesis of collagen, but also for the phagocytosis of collagen fibrils during the rapid remodelling of connective tissue.departmental bulletin pape

<ORIGINAL ARTICLE>Experimental Study on Salivary Gland Scintigraphy with ^<99m>Tc-pertechnetate

P(論文)In diagnosing salivary gland diseases, along with the remarkable progress of nuclear medicine, scintigraphic examinations are being utilized. On the other hand, sialographic diagnosis has been carried out from old time. But, in most cases, either scintigraphy or sialography has been used alone independently, and thus there have been very few papers reported on a comparison between the two. To study the fundamental relationship between scintigraphic findings and sialographic ones, scintigraphy and microsialography were carried out on the ligated parotid glands of rabbits. After ligation, comparisons were run on the 3rd day, 7th day, 10th day and 28th day. Pathological findings also were added. The results obtained were as follows; (1) Scintigraphic findings showed little changes in shape until the 3rd day after ligation, but, after the 7th day, a remarkable decrease of ^Tc-pertechnetate uptake was observed. (2) Microsialographic changes were observed in pararell with the uptake of ^Tc-pertechnetate. (3) Pathological findings definitely showed the relationship between scintigraphic findings and microsialographic findings.departmental bulletin pape

東日本史学雑誌投稿規定

S(会告など)departmental bulletin pape