著者

Takeshi OHNO Atsuko SHINOHARA Ichitaro KOHGE Momoko CHIBA Takafumi HIRATA

出版者

(社)日本分析化学会

雑誌

Analytical Sciences (ISSN:09106340)

巻号頁・発行日

vol.20, no.4, pp.617-621, 2004 (Released:2004-10-08)

参考文献数

18

被引用文献数

33 54

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Precise 56Fe/54Fe and 57Fe/54Fe isotopic ratios on human red blood cell (RBC) samples have been measured using multiple collector-ICP-mass spectrometry (MC-ICPMS). The mass spectrometric interferences on Fe isotopes (e.g., 56ArO+ and 57ArOH+) were successfully minimized by a dry plasma condition achieved by a desolvating nebulizer sample-introduction technique. In order to eliminate possible variations in the measured isotopic ratios due to non-mass spectrometric interferences, Fe was separated from remaining organic compounds and major co-existing elements using an ion chromatographic technique. The resulting precisions of the 56Fe/54Fe and 57Fe/54Fe ratio measurements were 0.12‰ and 0.20‰, respectively, which were high enough to detect the isotopic variation of Fe in nature. For an interlaboratory comparison, all of the Fe isotopic ratio data were normalized by the ratios for the IRMM-014 international isotopic standard. A series of 12 RBC samples were collected from one person through monthly-based sampling over a period of one year. These were analyzed to test possible seasonal changes in the 56Fe/54Fe and 57Fe/54Fe ratios. Moreover, in order to test possible variations in the 56Fe/54Fe and 57Fe/54Fe ratios among different people, RBC samples were collected from five volunteers (four males and one female). The 56Fe/54Fe and 57Fe/54Fe ratios for a series of 12 RBC samples collected over a one-year period show 3.06‰ and 4.51‰ lower than the values of IRMM-014, and no significant seasonal change could be found in the ratios. The lack in seasonal changes in the Fe isotopic ratios could be explained by a small contribution of the daily net-intake of Fe (1 - 2 mg/day) onto the total amount of Fe in the human body (2 - 4 g). The 56Fe/54Fe and 57Fe/54Fe ratios for RBC samples collected from four male samples did not vary measurably, whereas the Fe isotopic ratios for a female RBC were 0.3‰/amu heavier than the mean value of four male samples. This difference in Fe isotopes among the individuals can be the result of a difference in uptake efficiency of the Fe through a dietary process from the digestive tract. The data obtained here demonstrate that the isotopic ratios of trace metals can provide new information about metabolic efficiencies of the metallic elements.

著者

Akio Hoshi Hiromi Watanabe Masatoshi Kobayashi Momoko Chiba Yutaka Inaba Naoto Kimura Takashi Ito

出版者

Tohoku University Medical Press

雑誌

The Tohoku Journal of Experimental Medicine (ISSN:00408727)

巻号頁・発行日

vol.195, no.3, pp.163-169, 2001 (Released:2004-12-22)

参考文献数

31

被引用文献数

9 16

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Trace elements in sweat during sauna bathing were assessed. Sweat collected by the whole body method was compared with that collected by the arm bag method. The sweat samples were collected from ten healthy male adults aged 22-26 years, by heat exposure in dry sauna bathing (60°C, 30 minutes). Concentrations of major (Na, Cl, K, Ca, P and Mg) and trace (Zn, Cu, Fe, Ni, Cr and Mn) elements in sweat tended to be lower in the arm bag method than in the whole body method. It was found that Ca, Mg, Fe and Mn concentrations in the arm bag method were significantly lower than those in the whole body method. The amount of trace elements in sweat measured by the arm bag method was less than that by the whole body method; significant differences were observed in Fe and Mn amounts. These observations suggest that excretion of trace elements by sweating induces trace element decrease. Therefore, athletes and workers who work in a hot environment and sweat much habitually should ingest adequate amounts of trace elements.

著者

Tsuyoshi MATSUBA Momoko CHIBA Khongsap Akkhavong Aporn Sisuraj Yutaka INABA

出版者

The Japanese Society of Health and Human Ecology

雑誌

民族衛生 (ISSN:03689395)

巻号頁・発行日

vol.71, no.6, pp.255-262, 2005 (Released:2010-06-28)

参考文献数

13

被引用文献数

1

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尿路結石症が多発するラオスにおいて,食習慣や生活習慣に関連する因子と疾患発症との関係を明らかにすることを目的に症例対照研究が行われた.尿路結石症例114名および病院ベースでマッチされていない対照97名が調査対象として選ばれた.質問紙を用いて食習慣や生活習慣に関する因子について質問され,各因子についてオッズ比が求められた.また食習慣に関しては,各々の摂取食品項目がどのような因子によって成り立っているのかを明らかにするため因子分析が用いられた.更に共分散構造分析(構造方程式)を用いて食習慣と疾患との間の関係についてモデルを構築しそれぞれの関連を明らかにした.尿路結石は病因の異なる2つのグループ,すなわち上位尿路結石および下位尿路結石に分けられる.下位尿路結石については伝統的な摂取食品項目との間に正の関連を表し,近代的な摂取食品項目との間には負の関連を示した.対照的に上位尿路結石は伝統的な食品項目よりも近代的な食品項目との問により高いパス係数が認められた.ラオスでは今後食生活の近代化によって,下位尿路結石は減少するものの上位尿路結石の罹患は上昇することが考えられる.