Circadian rhythms in plasma levels of cortisol, dehydroepiandrosterone, Δ4-androstenedione, testosterone and dihydrotestosterone of healthy young men

1980 ◽  
Vol 94 (4) ◽  
pp. 536-545 ◽  
Author(s):  
Michel M. Guignard ◽  
Pierre C. Pesquies ◽  
Bernard D. Serrurier ◽  
Danielle B. Merino ◽  
Alain E. Reinberg
Keyword(s):  
Circadian Rhythms ◽  
Ethyl Ether ◽  
Plasma Levels ◽  
Plasma Sample ◽  
Young Men ◽  
Venous Catheter ◽  
Diurnal Activity ◽  
Androgenic Steroids ◽  
Healthy Males

Abstract. Three healthy males (18, 22 and 30 years of age; 85 kg/177 cm, 82 kg/181 cm and 75 kg/168 cm, respectively), synchronized with a diurnal activity (06.00 to 23.00 h) and nocturnal rest, volunteered for this study. Blood was sampled (venous catheter) hourly during a 24 h span. A radiocompetition method was used for cortisol determinations. Other steroids were first extracted (ethyl-ether) from each plasma sample, then chromatographed on a celite column to isolate 3 fractions: 1) Δ4-androstenedione (Δ-4); 2) dihydrotestosterone (DHT) and dehydroepiandrosteone (DHA); 3) testosterone (T). A radioimmunological assay was used thereafter for the determination of androgenic steroids. Statistically significant (both conventional and cosinor methods) circadian rhythms were detected (P < 0.005). Acrophases (peak times) occurred in the following order: cortisol (07.28), DHA (08.43), Δ-4 (09.54), T (11.15) and DHT (16.37). The respective circadian amplitudes of DHA and Δ-4 were smaller than those of cortisol while the amplitudes T and DHT did not show differences statistically significant from each other.

AGE- AND MENTAL HEALTH-RELATED CIRCADIAN RHYTHMS OF PLASMA LEVELS OF MELATONIN, PROLACTIN, LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE IN MAN

1981 ◽  
Vol 91 (3) ◽  
pp. 467-475 ◽  
Author(s):  
YVAN TOUITOU ◽  
MICHÈLE FÈVRE ◽  
MICHEL LAGOGUEY ◽  
ALAIN CARAYON ◽  
ANDRÉ BOGDAN ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Circadian Rhythms ◽  
Plasma Levels ◽  
Elderly Women ◽  
Young Men ◽  
The Elderly ◽  
Daily Activities ◽  
Mental Condition ◽  
Elderly Men ◽  
Health Related

Circadian changes in plasma levels of melatonin, prolactin, LH and FSH were studied in four groups: seven healthy young men, six elderly men, six elderly women and six elderly demented patients (two men and four women). The daily activities of the subjects were synchronous and blood samples were taken every 4 h. The 24-h mean concentrations of prolactin in plasma were the same in all groups, whereas those of LH and FSH were twice as high in the elderly as in the young men and eight and 23 times higher respectively in the elderly women. The 24-h mean plasma levels of melatonin in the elderly were half those in the young, but were not influenced by the sex or mental condition of the subjects. A statistically significant circadian rhythm for melatonin was defined in the four groups, for prolactin in all groups except the elderly men and for LH only in the demented patients and in the young men. No circadian rhythm could be detected for FSH in any of the four groups. The acrophases of melatonin and prolactin ranged between 02.30 and 04.00 h, those of LH (when a rhythm was validated) clustered around 01.00 h. The circadian rhythms of plasma levels of melatonin, prolactin and LH are not modified in old age nor in dementia. A positive correlation has been demonstrated in young men between melatonin and LH and between melatonin and prolactin, but no such correlation could be found in the elderly.

Procedures for the Quantitative Determination of Autoprothrombin C

1962 ◽  
Vol 08 (03) ◽  
pp. 434-441 ◽  
Author(s):  
Edmond R Cole ◽  
Ewa Marciniak ◽  
Walter H Seegers
Keyword(s):  
Quantitative Determination ◽  
Plasma Sample ◽  
Quantitative Measure ◽  
The Other ◽  
Clotting Time ◽  
Bovine Plasma ◽  
Autoprothrombin C

SummaryTwo quantitative procedures for autoprothrombin C are described. In one of these purified prothrombin is used as a substrate, and the activity of autoprothrombin C can be measured even if thrombin is in the preparation. In this procedure a reaction mixture is used wherein the thrombin titer which develops in 20 minutes is proportional to the autoprothrombin C in the reaction mixture. A unit is defined as the amount which will generate 70 units of thrombin in the standardized reaction mixture. In the other method thrombin interferes with the result, because a standard bovine plasma sample is recalcified and the clotting time is noted. Autoprothrombin C shortens the clotting time, and the extent of this is a quantitative measure of autoprothrombin C activity.

Identification of N-Monoacetylcystine in Uraemic Plasma

1981 ◽  
Vol 60 (3) ◽  
pp. 331-334 ◽  
Author(s):  
F. Gejyo ◽  
G. Ito ◽  
Y. Kinoshita
Keyword(s):  
Plasma Levels ◽  
Gel Filtration ◽  
Normal Subjects ◽  
Exchange Chromatography ◽  
Cysteic Acid ◽  
Homocysteic Acid ◽  
Normal Limits ◽  
Acidic Nature ◽  
Sulphur Amino Acids

1. An unidentified ninhydrin-positive substance of an acidic nature was detected in the plasma of uraemic patients. This substance was isolated from haemodialysate by ion-exchange chromatography and gel filtration, and identified as a sulphur-containing amino acid: N-monoacetylcystine. 2. The quantitative determination of sulphur amino acids in plasma revealed that the plasma levels of cysteic acid, homocysteic acid, taurine, cystine and cystathionine as well as N-monoacetylcystine in uraemic patients were markedly higher than in normal subjects (P < 0.001 for each). However, the plasma levels of methionine in uraemic patients were within normal limits.

Direct radioimmunoassay of 6-sulfatoxymelatonin in plasma with use of an iodinated tracer

1991 ◽  
Vol 37 (4) ◽  
pp. 536-539 ◽  
Author(s):  
Catherine Harthé ◽  
Bruno Claustrat ◽  
Jocelyne Brun ◽  
Guy Chazot
Keyword(s):  
Plasma Sample ◽  
Limit Of Detection ◽  
Circadian Variation ◽  
Hepatic Metabolism ◽  
Pharmaceutical Formulations ◽  
Practical Application ◽  
Bovine Serum Albumin Conjugate ◽  
Preliminary Study ◽  
Related Compounds

Abstract We describe here a direct a radioimmunoassay (RIA) for the determination of 6-sulfatoxymelatonin (aMT6s) in plasma, with iodinated aMT6s as tracer. The aMT6s antiserum was raised in rabbit by immunization with a bovine serum albumin conjugate, giving negligible cross-reactivities for related compounds. The low limit of detection (15 pmol/L) allowed a direct assay that required only a 100-microL plasma sample. Dilutions of plasma and of synthetic aMT6s gave the same parallel response in the RIA. A preliminary study showed a circadian variation in healthy volunteers, with mean concentrations ranging from 52 (at 1600-2100 h) to 378 pmol/L (at 0400 h), whereas this rhythm was abolished in pinealomectomized patients. After administration of melatonin orally, or by infusion, the aMT6s concentrations in plasma concorded with previous data on aMT6s production and pharmacokinetics, with aMT6s being cleared from plasma more slowly than melatonin. This assay should have practical application in the development of new pharmaceutical formulations that minimize the hepatic metabolism of melatonin.

Catecholamine and blood lactate responses to incremental rowing and running exercise

1994 ◽  
Vol 76 (3) ◽  
pp. 1144-1149 ◽  
Author(s):  
A. Weltman ◽  
C. M. Wood ◽  
C. J. Womack ◽  
S. E. Davis ◽  
J. L. Blumer ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Blood Lactate ◽  
Venous Catheter ◽  
Incremental Exercise ◽  
Plasma Epinephrine ◽  
O2 Uptake ◽  
Running Exercise ◽  
Rowing Ergometer ◽  
Per Se

Ten collegiate rowers performed discontinuous incremental exercise to their tolerable limit on two occasions: once on a rowing ergometer and once on a treadmill. Ventilation and pulmonary gas exchange were monitored continuously, and blood was sampled from a venous catheter located in the back of the hand or forearm for determination of blood lactate ([La]) and plasma epinephrine ([Epi]) and norepinephrine ([NE]) concentrations. Thresholds for lactate (LT), epinephrine (Epi-T), and norepinephrine (NE-T) were determined for each subject under each condition and defined as breakpoints when plotted as a function of O2 uptake (VO2). For running, LT (3.76 +/- 0.18 l/min) was lower (P < 0.05) than Epi-T (4.35 +/- 0.14 l/min) and NE-T (4.04 +/- 0.19 l/min). For rowing, LT (3.35 +/- 0.16 l/min) was lower (P < 0.05) than Epi-T (3.72 +/- 0.22 l/min) and NE-T (3.70 +/- 0.18 l/min) and was lower (P < 0.05) than LT for running. Within each mode of exercise, Epi-T and NE-T did not differ. Because LT occurred at a significantly lower VO2 than either Epi-T or NE-T, we conclude that catecholamine thresholds, per se, were not the cause of LT. However, for both modes of exercise LT occurred at a plasma [Epi] of approximately 200–250 pg/ml (rowing, 221 +/- 48 pg/ml; running, 245 +/- 45 pg/ml); these concentrations are consistent with the plasma [Epi] reported necessary for eliciting increments in blood [La] during Epi infusion at rest. Plasma [NE] at LT differed significantly between modes (rowing, 820 +/- 127 pg/ml; running, 1,712 +/- 217 pg/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Determination of individual teleroentgenographic characteristics of the face profile in ukrainian young men and girls with orthognathic bite

2018 ◽  
pp. 28-34
Author(s):  
М. О. Dmitriev
Keyword(s):  
Regression Analysis ◽  
Soft Tissue ◽  
Young Women ◽  
Stepwise Regression ◽  
Young Men ◽  
Stepwise Regression Analysis ◽  
Regression Equations ◽  
Determination Coefficient ◽  
Normal Occlusion

Modern dentistry requires the definition of individualized values of teleroentgenographic indicators. To solve such problems, methods of regression and correlation analysis are increasingly used, which help to establish not only the existence of various relationships between the anatomical structures of the head and the parameters of the dento-jaw system, but also allow more accurately predict the change in the contour of soft facial tissue in response to orthodontic treatment. The purpose of the study is to develop mathematical models for the determination of individual teleroentgenographic characteristics of the facial soft tissues by studying the cephalometric indices of young men and women of Ukraine with normal occlusion and balanced faces and conducting a direct stepwise regression analysis. With the use of Veraviewepocs 3D device, Morita (Japan) from 38 young men (17 to 21 years of age) and 55 young women (aged from 16 to 20 years) with occlusal close to the orthognathic bite and balanced faces received side teleroentgenograms. The cephalometric analysis was performed using OnyxCeph³™ licensed software. Cephalometric points and measurements were made according to the recommendations of Downs W. B., Holdway R. A., McNamara J., Schwarz A. M., Schmuth G. P. F., Steiner C. C. and Tweed C. H. With the help of direct stepwise regression analysis, in the licensed package “Statistica 6.0”, regression models of individual teleroentgenographic characteristics of the profile of soft facial tissues were constructed. In young men with normal occlusion close to the orthognathic bite of 19 possible models, 11 were constructed with a determination coefficient from 0.638 to 0.930, and in young women – 12 models with a determination coefficient from 0.541 to 0.927. The conducted analysis of models showed that in young men most often the regression equations included – angle N_POG, parameters of which indicate a linear interjaw relation in the anterior-posterior direction (14.0%); angle GL_SNPOG, or index of convexity of the soft tissue profile (8.8%); MAX maxillary length (7.0%), and GL_SN_S index, which defines vertical correlations in the facial profile (5.3%). The young women most often models included – the angle N_POG (12.5%); angle GL_SNPOG (7.5%); soft tissue front angle P_OR_N (6.25%); the reference angle ML_NL and the profile angle T (by 5.0%); the angle AB_NPOG, the angle NBA_PTGN, which defines the direction of development of the mandible and the distance PN_A (3.75%). Thus, in the work with the help of the method of stepwise regression with inclusion, among Ukrainians of adolescence age, based on the characteristics of teleroentgenographic indicators, reliable models of individual teleroentgenographic characteristics of the profile of soft facial tissues were developed and analyzed.

scholarly journals Autonomic and endothelial dysfunction with neurocirculatory asthenia in young men of call-up age

2019 ◽  
Vol 10 (2) ◽  
pp. 27-31
Author(s):  
Vladimir S. Ivanov ◽  
Lilia I. Levina ◽  
Sergey N. Ivanov ◽  
Vladimir S. Vasilenko
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Endothelial Dysfunction ◽  
Cardiac Activity ◽  
Young Men ◽  
Mean Value ◽  
Regulation Type ◽  
Vasodilator Reserve ◽  
Vegetative Regulation

Young men of call-up age with neurocirculatory were asthenia were examined for autonomic regulation of cardiac activity and vasodilatory reserve of the arteries. The functional state of the autonomic nervous system (ANS) was studied with the aid of rythmography with analyse of heart rate variability. The following parameters were studied: vegetative regulation type, responsiveness of departments of ANS and autonomic provision of cardiac activity. The type of vegetative regulation was determined by the mean value of RR interval and indication of the heart rate variability (∆RR). Reactivity of parasympathetic and sympathetic divisions of the ANS and autonomic support of cardiac activity were investigated using breathing test. To ensure vegetative dysadaptation cardiac activity includes reaction with low vegetative coverage of both divisions of the ANS and paradoxical reaction in which there is a decrease in ∆RRmax (instead of increase) and an increase in ∆RRmin instead of decrease. These reactions indicate autonomic dysfunction. Vasodilatory reserve of the arteries was investigated using ultrasonography of the brachial artery with compressive sample and determination of endothelium-dependent vasodilation. It was found that in boys with neurocirculatory asthenia vagotonic and sympathetic types of vegetative regulation are often determined by disadaptative vegetative provision of cardiac activity, which is accompanied by endothelial dysfunction with reduced vasodilator reserve of the arteries.

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