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It has been established that various species exhibit personality, defined as intra-individual consistency and inter-individual variation in behavioural phenotypes. For example, certain individuals may demonstrate consistently greater behavioural reactions and elevated stress responses. We conducted playback experiments and hormonal analyses on male chimpanzees (Pan troglodytes) in captivity to investigate the patterns and proximate mediators of individual variations in behavioural reactions. We found intra-individual consistency and inter-individual variation in behavioural reactions (intensive vigilance towards the direction of speakers) to vocalisations by unfamiliar chimpanzees. This behavioural reaction was positively correlated with changes in salivary cortisol concentration, suggesting that stress is a proximate factor mediating the variation in behavioural reactions. The males who were highly responsive to the conspecific vocalisation also exhibited high behavioural reactions towards the neutral broadcast stimulus (the jungle crow's Corvus macrorhynchos 'ka' vocalisation). This observation is consistent with the notion that male chimpanzees vary in intrinsic behavioural tendency to different stimuli.

【目的】アメリカ軍は１９６１年から１９７１年の間に８０００万リットル以上の枯葉剤を南ベトナムに撒布した。この研究の目的はベトナムの枯葉剤高濃度汚染地域（Binh Dinh省Phu Cat県）と非汚染地域（Ha Nam省Kim Bang県）において枯葉剤（オレンジ剤）の暴露と人体への健康影響との関連を検討することである。【方法】２つの地域において疫学的調査を実施した。対象者は授乳中で生後４週から１６週の乳児を持つ２０－３０歳の母親とし、汚染地域では５８名、非汚染地域では５３名であった。疾患の危険因子等に関する情報は母親への面接調査から得た。母乳をすべての対象者から採取したが、唾液を採取したのは汚染地域４１名、非汚染地域１９名であった。母親と子どもの身体計測を行い２地域間で比較を行った。【結果と考察】汚染地域における乳児の体重と胸囲は有意に非汚染地域よりも小さいが、年齢(週数)も汚染地域の方が有意に低かった。汚染地域における母親とその家族の現病歴は非汚染地域よりも有意に多かった。母親の視力は両眼とも２地域間で有意差は認められなかった。汚染地域と非汚染地域双方の母親の唾液中のコルチゾン値は、母乳中のコルチゾン値と高い相関を示した。汚染地域と非汚染地域間で唾液中のホルモン値には有意差は認められなかった。Objective : Between 1961 and 1971 the US military used over 80 million litres of herbicides in southern Vietnam. This study aims to assess hormone levels in the saliva of lactating Vietnamese mothers and human health effects in a dioxin hot spot (Phu Cat district, Binh Dinh province) and a non-exposed (Kim Bang district, Ha Nam province) area in Vietnam. Materials and Methods : An epidemiological study was carried out in both areas. The subjects were 58 lactating females in the hot spot area and 53 lactating females in the non-exposed area. All were aged between 20 and 30 years with infants aged between 4 and 16 weeks. Information about disease risk factors was obtained through interviews with mothers. Breastmilk samples were taken from all subjects, whereas saliva samples were obtained from 41 mothers in the hot spot area and 19 in the non-exposed area. Body measurements for both mothers and their infants were compared between the two areas. Result and Discussion : The weight and chest circumference of infants in the hot spot area were significantly lower than those in the non-exposed area, whereas age (weeks) is also significantly younger in hot spot area than non-exposed area. Present maternal and family diseases in the hot spot area were significantly higher than those in the non-exposed area. Maternal eyesight in both eyes did not differ significantly between the two areas. The cortisone levels in saliva have been found to be closely related to those in breast milk samples of both mothers in hot spot and non-exposed areas. No significant difference was found between salivary hormone levels of mothers in the hot spot and non-exposed areas.

Adrenal venous sampling is currently the only reliable method to distinguish unilateral from bilateral diseases in primary aldosteronism. In this study, we attempted to determine whether peripheral plasma levels of 18-oxocortisol (18oxoF) and 18-hydroxycortisol could contribute to the clinical differentiation between aldosteronoma and bilateral hyperaldosteronism in 234 patients with primary aldosteronism, including computed tomography (CT)-detectable aldosteronoma (n=113) and bilateral hyperaldosteronism (n=121), all of whom underwent CT and adrenal venous sampling. All aldosteronomas were surgically resected and the accuracy of diagnosis was clinically and histopathologically confirmed. 18oxoF and 18-hydroxycortisol were measured using liquid chromatography tandem mass spectrometry. Receiver operating characteristic analysis of 18oxoF discrimination of adenoma from hyperplasia demonstrated sensitivity/specificity of 0.83/0.99 at a cut-off value of 4.7 ng/dL, compared with that based on 18-hydroxycortisol (sensitivity/specificity: 0.62/0.96). 18oxoF levels above 6.1 ng/dL or of aldosterone32.7 ng/dL were found in 95 of 113 patients with aldosteronoma (84%) but in none of 121 bilateral hyperaldosteronism, 30 of whom harbored CT-detectable unilateral nonfunctioning nodules in their adrenals. In addition, 18oxoF levels below 1.2 ng/dL, the lowest in aldosteronoma, were found 52 of the 121 (43%) patients with bilateral hyperaldosteronism. Further analysis of 27 patients with CT-undetectable micro aldosteronomas revealed that 8 of these 27 patients had CT-detectable contralateral adrenal nodules, the highest values of 18oxoF and aldosterone were 4.8 and 24.5 ng/dL, respectively, both below their cut-off levels indicated above. The peripheral plasma 18oxoF concentrations served not only to differentiate aldosteronoma but also could serve to avoid unnecessary surgery for nonfunctioning adrenocortical nodules concurrent with hyperplasia or microadenoma.