Circadian and circannual rhythms of T3 and T4 secretions in Polwarth–Ideal rams
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Circannual rhythm
The present study aimed to investigate probability of a possible endogenous circadian rhythm in human cognitive attribute to estimate short intervals. Apparently healthy young males and females were selected for our study. Eight subjects prospectively produced the short-time intervals 10 s and 60 s at 2 hourly intervals in 30 h constant routine (CR) study conducted in spring (CR-1). The study was repeated again in autumn (CR-2) in the remaining eight subjects. The established circadian markers, namely serum cortisol, salivary melatonin levels and tympanic temperature were also measured either in CR-1 or CR-2. Oral temperature was measured simultaneously. Circadian rhythms were validated in serum cortisol, salivary melatonin, oral, and tympanic temperatures. Circadian rhythm in 60 s estimates was observed in a few subjects and in all males at group level in CR-1. The cognitive attribute to perceive short intervals vary as function of season. The results provide evidence in support of interaction among the interval, circadian and circannual timing systems in human.
Circannual rhythm
Chronobiology
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Competitive binding
Thyroxine-binding globulin
Reverse triiodothyronine
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Triiodothyronine concentration was determined in human serum and in thyroid extracts by two radioimmunoassay technics. Both antibodies, radioactive T3, stable T3, protein-binding-hormone inhibitors, methods used to separate the free from the bound fractions were different. Each factor from a method was substituted to the homologue of the other method. The results occasionally showed a variation of 32 p. cent in the first method and 50 p. cent in the second one. However the results gave a correct interpretation of the triiodothyronine values measured in human serum and in thyroid extracts.
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直接法によるradioimmunoa ssayキットを使用して, 108名の患者の血清T3濃度を測定し, T3の臨床意義について考察した。最小検出量, 測定範囲, 再現性とも満足できるものであった。血清T3濃度は健常人では1.15±0.28ng/ml, 甲状腺機能低下症0.33±0.10ng/ml, 甲状腺機能亢進症5.15±1.81ng/mlであった。血清T3濃度とT4濃度の相関係数は+0.84であり, 非常に良い相関を認めたが, 相関しない興味深い3状態を認めた。 (1) 高T3血症, (2) 低T4濃度を伴う正常T3血症, (3) 低T3濃度を伴う正常T4血症。未治療患者5名 (4.6%) において (1) に属する者を認めた。 (2) においては血清TSH濃度はいずれも高値を示したが (3) においては正常範囲にあるものも認めた。
Clinical Significance
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We had previously observed a circadian rhythm for serum TSH in male Sprague-Dawley rats (under a 12-hour light-dark cycle, light off at 19.00 h). In the present work the parameters of this previously observed TSH rhythm were determined over a year on a monthly basis. A circadian rhythm was detected for each month except April. From month to month, the amplitudes and acrophases of these rhythms were not significantly different, and a circannual rhythm was only established for the mean TSH concentration over the 24-hour period (mean hormonal value). We conclude that there is a constant circadian pattern for serum TSH fluctuations superimposed on a small basal circannual rhythm of the mean hormonal value.
Infradian rhythm
Basal (medicine)
Circannual rhythm
Chronobiology
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Fraction (chemistry)
Reverse triiodothyronine
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Abstract Study of the biological rhythms in cavernicoles is of considerable interest especially since the cave ecosystem is characterized by absence of light, relatively constant temperature and relatively high and constant humidity. The present paper documents for the first time multifrequency biologic rhythms in air gulping behaviour of a cavernicolous fish Oreonectus evezardi, kept under complete darkness, DD. A circadian rhythm was demonstrated with statistical significance by cosinor method for air‐gulping activity during 9 months out of 14 months of observations. A 6‐monthly rhythm in circadian mesor was detected. However, statistically significant circannual rhythms in circadian amplitude and circadian acrophase were validated. Thus, results of the present study clearly demonstrate semicircannual or circannual modulation of the circadian behavioural rhythm of a cave dwelling teleost.
Circannual rhythm
Chronobiology
Darkness
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This report describes the development of a sensitive, precise, radioimmunoassay for the measurement of triiodothyronine in unextracted serum, documents serum levels of triiodothyronine in various states of thyroid dysfunction, and assesses the role of the triiodothyronine radioimmunoassay as a routine test of thyroid function.
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Coefficient of variation
Serum concentration
Free thyroxine
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