アブストラクト(25巻3号:神奈川歯学)

神奈川歯学

Japanese

Title : アミノ酸ラセミ化法による歯からの年齢推定に関する研究 -Asp, GluおよびAlaの比較-
Subtitle : 原著
Authors : 菅野均*1,*2, 山本勝一*1, 斎藤滋*2
Authors(kana) :
Organization : *1神奈川歯科大学法医学教室, *2神奈川歯科大学口腔生化学教室
Journal : 神奈川歯学
Volume : 25
Number : 3
Page : 306-315
Year/Month : 1990 / 12
Article : 原著
Publisher : 神奈川歯科大学学会
Abstract : 「緒言」 歯は, 個人識別上, 腐乱死体や白骨死体など身元不明者の確認にはなくてはならない重要な検査資料の1つである. また, 検査項目の中で, 年齢推定の対象としては歯が最も密接に関連をもっていると古くより考えられ, 多くの報告がみられる. 一方, 生体組織中の蛋白質は, 新陳代謝により絶えず分解され, 排泄されている. このため, 蛋白質構成アミノ酸のほとんどはL型のアミノ酸で占められている. しかし, 代謝回転のおそい骨, 歯, 水晶体および脳などではD型のアミノ酸が蓄積され, 加齢に伴い増加する傾向が見られる. 1976年, Helfman and Badaは, アミノ酸のラセミ化反応を利用する歯(象牙質)からの年齢推定法(アミノ酸ラセミ化法)を見いだした. これは, 歯の象牙質中のD-アスパラギン酸(Asp)が, 加齢に伴いほぼ規則的に増加する(r=0.979)現象をとらえたものである.
Practice : 歯科学
Keywords : アミノ酸ラセミ化法, 歯からの年齢推定, Asp, GluおよびAlaの比較

English

Title : Age Estimation by Amino Acid Racemization in Teeth -A Comparison of Data for Aspartic Acid, Glutamic Acid and Alanine-
Subtitle :
Authors : Hitoshi SUGENO*1,*2, Katsuichi Yamamoto*1, Shigeru Saito*2
Authors(kana) :
Organization : *1Department of Forensic Medicine, Kanagawa Dental College, *2Department of Oral Biochemistry, Kanagawa Dental College
Journal : Kanagawa Shigaku
Volume : 25
Number : 3
Page : 306-315
Year/Month : 1990 / 12
Article : Original article
Publisher : Kanagawa Odontological Society
Abstract : [Abstract]: On the age estimation by the amino acid racemization analysis of dentin, besides the utilization of aspartic acid (Asp) as described in earlier reports, we further studied relationships between the D/L ratios based on glutamic acid (Glu) as well as alanine (Ala) and actual ages. The study was followed up by comparing racemization velocities of the three amino acids under some heating experiments. At four steps (6, 24, 48 and 72 hours) of hydrolysis, the coefficient values of D/L ratio of each amino acid and actual age were calculated as 0.986 to 0.994 for Asp, 0.522 to 0.806 for Glu, and 0.577 to 0.737 for Ala. The data indicate that Asp gives an extremely good result. Glu and Ala do provide reliable D/L ratios, however they are not in proportion to actual ages. Consequently, Glu and Ala seem to be much less suitable for utilization in age estimation. Reaction rate constants (k・yr-1) of racemization of Asp, Glu and Ala in antemortem teeth were 5.3825×10-4, 5.1000×10-5 and 2.3875×10-5, respectively. Those in teeth left drying at 15℃ were 2.4850×10-8, 1.9119×10-9, and 1.11450×10-9, respectively. Assuming that the reaction velocity of Asp be 1 in both living and dry states, that of Glu were calculated as 0.09 and 0.08, that of Ala, 0.04 and 0.05, indicating very similar rates. The result confirmed that both Glu and Ala gave considerably slow racemization velocities as compared with Asp.
Practice : Dentistry
Keywords :