Disposition of oxazepam in relation to age,sex, and cigarette smoking

Summary The kinetics of single 30-mg oral doses of oxazepam were determined in 22 male and nine female volunteers aged 20–86 years. Oxazepam plasma concentrations were measured in multiple plasma samples drawn during 36 h after each dose. Mean kinetic variables in males and females, respectively, were: elimination half-life, 7.5 and 8.5 h; volume of distribution, 0.96 and 1.17 l/kg; clearance, 1.48 and 1.70 ml/min/kg. Sex differences were not significant, nor were any of the kinetic variables significantly related to age. However, oxazepam clerance increased significantly with heavier cigarette smoking (r=0.48,p<0.01). Mean clearance in smokers (1.98 ml/min/kg) was significantly higher than in non-smokers (1.23 ml/min/kg,p<0.01). Thus, smoking is a more important determinant of oxazepam clearance than age or sex.Supported in part by Grant Oc 10/4 from the Deutsche Forschungsgemeinschaft, Bonn-Bad Godesberg, Federal Republic of Germany; and Grant MH-34223 from the United States Public Health Service     

Thermoregulation during heat exposure of young children compared to their mothers

The study was conducted to investigate the thermoregulation of young children compared to that of adults. A group of 19 children (ages 9 months-4.5 years), with only 3 children aged 3 years or above, and 16 adults first rested in a thermoneutral room (air temperature 25°C relative humidity 50%, air velocity 0.2 m·s^–1). They were then exposed to a hot room (air temperature 35°C, relative humidity 70%, air velocity 0.3 m·s^–) next door for 30 min, and then returned to the thermoneutral room where they stayed for a further 30 min. The rectal temperature (T _re), skin temperatures (T _sk) at seven sites, heart rate (HR), total sweat rate ( ), local sweat rate ( ) and the Na⁺ concentration of the sweat were measured. There was no significant difference inT _re between the children and their mothers in the rest phase. However, theT _re of the children increased as soon as they entered the hot room and was significantly higher than during the control period, and than that of the mothers during heat exposure. MeanT _sk, forehead, abdomen and instepT _sk were significantly higher in the children during both the thermoneutral and heat exposure. The was significantly higher and Na⁺ concentrations in the sweat on the back and upperarm were significantly lower for the children during the heat exposure. They had a greater body surface area-to-mass ratio than the mothers by 64%, which indicated that they had advantages for thermal regulation. However, the sweating andT _sk responses of the children were not enough to prevent a rise in body temperature. These results would suggest that the young children had the disadvantage of heating up easily due to their smaller body sizes and there may be maturation-related differences in thermoregulation during the heat exposure between young children and mothers.     

Dimensions of cervical vertebral bodies according to age and sex

Summary A biometric comparative roentgenological study of the cervical vertebral bodies was performed, according to age and sex, from lateral roentgenograms of 120 adult cervical regions. The sexual dimorphism already described by many authors was confirmed. The vertebral bodies of C2, C3, and C7 have the more variable structure according to age. The results of our measurements are in accordance with clinical findings and provide data on the structural changes of the cervical spine during ageing. In anthropological terms, the vertebral body of C2, in particular its antero-posterior diameter, is the best age indicator, irrespective of individual and exterior variables.

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Mesures des corps vertébraux cervicaux en fonction de l'âge et du sexe

Résumé Les auteurs ont réalisé une étude biométrique comparative des corps vertébraux cervicaux, en fonction du sexe et de l'âge, à partir de radiographies de la colonne cervicale de profil pratiquées chez 120 individus. On retrouve le dimorphisme sexuel net, déjà décrit par plusieurs auteurs. Les corps vertébraux de C2, C3 et C7 sont ceux dont la structure varie le plus avec l'âge. Les résultats de nos mesures sont en accord avec les constatations cliniques et précisent les données sur les changements structuraux de la colonne cervicale au cours du vieillissement. D'un point de vue plus strictement anthropologique, le corps vertébral de l'axis et plus précisément son diamètre sagittal, est le meilleur indicateur d'âge, indépendamment des facteurs extérieurs et individuels.

     

Effects of age,sex, and prior body weight on the development of dietary obesity in adult rats

Adult male and female rats were fed either lab chow (Groups 2 and 3) or lab chow and an assortment of palatable supermarket foods (Group 1) during Days 1–60 of the experiment. All rats were maintained on only lab chow during Days 61–90. Group 1 and 3 rats were then given the supermarket diet during Days 91–150, while Group 2 rats continued on lab chow only. The rats fed the supermarket diet significantly more body weight than did the lab chow fed rats, and this dietary obesity was greater in the older rats (i.e., during the Days 91–150 of the experiment) than in the younger rats (Days 1–60). Male rats gained as much or more weight on the supermarket diet as did the females, but compared to the same-sexed chow fed rats females displayed greater weight gains than did males. Finally, during Days 91–150 Group 1 and 3 rats gained similar amounts of weight on the supermarket diet despite the fact that the Group 1 rats had previous experience with the diet and had been overweight as a result. The findings demonstrate that age and sex, but not prior experience with palatable foods and overweight, are important factors in the development of dietary obesity in adult rats. The similarity between dietary obesity and hypothalamic obesity with respect to these three factors is discussed.     

Dehydroepiandrosterone sulphate and dehydroepiandrosterone in serum: differences related to age and sex

Serum concentrations of dehydroepiandrosterone sulphate (DHAS) were determined in 590 healthy women aged 20–87 yr. Simultaneous assays of dehydroepiandrosterone (DHA) were performed in 417 of the women. DHA and DHAS levels correlated negatively with age while the DHA/DHAS ratio proved to be unrelated to age. When values for 60 healthy men in the age range 20–84 yr were compared with those obtained in 60 randomly-selected healthy women who were exactly age-matched, the DHAS levels were found to be significantly lower and the DHA/DHAS ratios significantly higher in the women. These results might be of use in establishing normal clinical ranges for serum DHA, DHAS and the DHA/DHAS ratio in women.     

年龄、性别在幼鼠胸腺T细胞增殖中的作用

目的：分析年幼小鼠性别、年龄与CD3、CD4、CD8免疫参数表达的关系。方法：分离3—9周小鼠胸腺、脾脏T淋巴细胞，FACS分析细胞表面CD3、CD4、CD8的表达；CFSE标记后细胞，加入ConA、抗TCR抗体、PMA IONO刺激剂培养72小时，流式细胞仪分析的方法比较不同刺激剂作用下雌、雄小鼠T细胞的增殖。结果：结果胸腺和脾脏表面CD3、CD4、CD8的表达与性别无明显关系，6-9周小鼠脾脏CD3^ 细胞明显多于3—4周小鼠；胸腺细胞的增殖与年龄、性别无关，而3周雌性小鼠脾细胞对PMA IONO刺激后的增殖应答比雄性明显，4-6周雄性小鼠脾细胞的增殖能力强于雌性小鼠，7—8周雌性小鼠脾细胞对抗TCR抗体的应答能力明显减小。结论：免疫系统的雌雄异型可能早于青春期。     

Urinary excretion of free noradrenaline and adrenaline related to age,sex and hypertension in 265 individuals

Summary Urinary excretion of free noradrenaline and adrenaline during 24 h in 265 individuals was determined and related to sex, age, and hypertension as one indicator of the average sympathetic drive. Noradrenaline was found to correlate positively with age in healthy individuals. Noradrenaline and adrenaline were lower in healthy women than in men during the first half of life expectancy. Catecholamine excretion was similar in men and women in the second half of life expectancy. In hypertensive individuals, catecholamine excretion was slightly higher in the first half, and significantly higher in the second half of life expectancy. We assume that the differences in catecholamine excretion can contribute to the sex- and age-related differences in incidence of cardiovascular diseases, such as hypertension and cornonary heart disease.Supported by Bundesinstitut für Sportwissenschaften, Köln-Lövenich, FRGDedicated to Professor Dr. W. Gerok on the occasion of his 60th birthday     

Cardiovascular responses to heat stress and blood volume displacements during exercise in man

Summary Subjects exercised in the upright position at approximately 50% of maximal oxygen consumption in four situations: in 25 C air, in 45 C air [mean skin temperature ( _sk) 35 C], in 35 C water immersed to the level of the xiphoid process, and finally wearing a suit perfused with 35 C water. The water immersion prevented gravitational shifts of blood volume to the legs. In this situation the forearm blood flow (FBF) rose continually with increasing core temperature (T_es) in contrast to the attenuation in rise above 38 C T_es in 45 C air. The differences were significant above 38.6 C T_es in experiments in eight subjects. The effects of immersion on cardiac output (CO), stroke volume (SV), and heart rate (HR) were studied in five of the subjects in relation to T_es, since the rate of rise of T_es was different in the four situations. CO and SV tended to be higher during both rest and exercise in the water than in the other three conditions, while HR rose in the same manner with increasing core temperature, except that it was lower in 25 C air, where T_es was lower. Thus, the prevention of hydrostatic shifts of peripheral venous volume permitted the maintenance of a higher SV and peripheral blood flow, and enhanced the ability of the circulation to deal with the combined exercise and heat stress.Supported by the Danish Space Board (1112-32/81), the Danish Medical Research Council (512–15983), and the Danish Sports Research Council. Dr. Rowell was supported in part by NHLBI Grant HL 16910     

不同年龄及性别健康成人血浆同型半胱氨酸的水平研究

目的: 分析不同性别及年龄健康成人的血浆同型半胱氨酸(Hcy)水平,明确健康人群Hcy的标准,为高Hcy血症的防治提供指导和依据。方法: 剔除高血压、脑卒中、冠心病等常见致血Hcy升高因素的健康体检人群,共738人,按不同年龄分为青(≤35岁)、中(≥36,<60岁)、老(≥60岁)3组,并按性别分为男女亚组,以循环酶法分别测定其血浆Hcy水平,进行比较。结果: 各年龄组男性均高于女性(P<0.01);同时男女各组Hcy均随年龄增加而升高,青、中、老组比均有显著差异(P<0.01);男性均数为13.26 μmol/L,女性为9.68 μmol/L,差异显著(P<0.01); 多数男性(73.21%)血Hcy水平在10.01-15.00 μmol/L间,多数女性(84.06%)小于10.00 μmol/L。 结论: (1) 健康成人血浆Hcy水平存在性别和年龄的差异,男性高于女性,并随年龄增加而逐渐升高。(2) 正常健康成人血浆Hcy水平高限的确定,应考虑性别及年龄因素。     

Glucoregulation and hormonal changes during prolonged exercise in boys and girls

A group of 17 children, 8.5–11 years old, performed a 60-min cycle exercise at 60% of maximal oxygen uptake (VO_2max) 2 h after a standardized breakfast. They were 10 young boys (pubertal stage =1) and 7 young girls (pubertal stage 2) of similarVO_2max (respective values were 48.5 ml min^–1 kg^–1, SEM 1.8; 42.1 ml min^–1 kg^–1, SEM 2.4). Blood samples of 5 ml were withdrawn by heparinized catheter, the subjects being in a supine position, 30 min before the test, then after 0, 15, 30 and 60 min of exercise and following 30 min recovery. Haematocrit was immediately measured. Thereafter plasma was analysed for glucose, non-esterified fatty acid, glycerol, catecholamine (noradrenaline, adrenaline), insulin and glucagon concentrations. This study showed two main results. First, the onset of exercise induced a significant glucose decrease (of about 11,4%) in all the children. Secondly, both the glycaemic and the hormonal responses were obviously different according to the sex. In boys only, the initial glucose drop was significantly correlated to the pre-exercise insulin values. Whatever the time, the glycaemic levels and the catecholamine responses were lower in girls than in boys, whereas the insulin values remained higher. However, none of these two hormonal parameters seemed to be really responsible for the lower glucose values in girls. On the one hand, the great individual variability of noradrenaline and adrenaline and differences in their relative intensity at the end of the exercise between boys and girls might contribute to the lower catecholamine levels in girls. On the other hand, the lack of a significant relationship in girls between the glucose decrease after exercise and the pre-exercise insulin values might be explained by a relative insulin insensitivity concomitant with the earlier growth spurt in girls, as demonstrated in subjects at rest by other authors. Finally the mechanisms of all these gender differences remain to be clarified and might be accounted for by a different maturation level in boys and girls.     

Joint acceleration during gait in relation to age

Forty-four male and female subjects with no history of falling and whose ages ranged from 10 to 68 years participated in a series of experiments to assess movement at the joints during gait while walking in a straight line, in pivot turns and in turns of 0.33 and 0.66 m diameter. Acceleration at the joints in the forward and side-to-side direction was measured by dual-axis accelerometers placed at the ankles, knees, hips, shoulders, and on the head. Eye movement was assessed from electrodes placed on the sides of the eyes. The results of the experiments showed that for people whose age was above 40 years, significant increases in the forward-back and side-to-side movements occurred at all joints and progressively increased with age. By age 60, adverse movement of the joints as much as quadrupled in many subjects when compared to people whose age was 20–30 years. The increase in joint acceleration occurred equally in the front-back and side-to-side planes. The mechanism of the increased joint movement may be due to tendon laxness, peripheral neuropathy or loss of central control of gait due to age. Accelerometry may be a much more sensitive technique to analyze abnormalities in gait than standard video or observational gait analysis. Results are given as mean (SD) unless otherwise stated.     

Control of heat-induced cutaneous vasodilatation in relation to age

Summary Well matched unacclimatised older (age 55–68, 4 women, 2 men) and younger (age 19–30, 4 women, 2 men) subjects performed 75 min cycle exercise (40% ) in a hot environment (37°C, 60% rh). Rectal temperature (T _re), mean skin temperature (¯T _sk), arm blood flow (ABF, strain gauge plethysmography), and cardiac output (Q, CO₂ rebreathing) were measured to examine age-related differences in heat-induced vasodilatation.T _re and¯T _sk rose to the same extent in each group during the exposure. There was no significant intergroup difference in sweat rate (older: 332±43 ml · m^–2 · h^–1, younger: 435±49 ml · m^–2 · h^–1; mean±SEM). However, the older subjects responded to exercise in the heat with a lower ABF response which could be attributed to a lower for the same exercise intensity. The slope of the ABF-T _re relationship was attenuated in the older subjects (9.3±1.3 vs 17.9±3.3 ml · 100 ml^–1 · min^–1 · °C^–1,p <0.05), but theT _re threshold for vasodilatation was about 37.0°C for both groups. These results suggest an altered control of skin vasodilatation during exercise in the heat in older individuals. This attenuated ABF response appears to be unrelated to , and may reflect an age-related change in thermoregulatory cardiovascular function.     

Effect of voluntary dehydration on thermoregulatory responses to heat in men and women

Summary The effects of dehydration prior to heat exposure on sweating and body temperature were tested in 8 men and 8 women, dehydration being 1.3 and 1.0% of body weight, respectively. The subjects were exposed to 40° C for 60 min. Compared with controls (C), in the dehydrated men (D) there was a longer delay in the onset of sweating (C, 7.8, D, 11.6 min,p<0.05), a lower total sweat loss (C, 153, D, 127 g · m^-2 · h^–1,p< 0.001), and a greater increase in Tre (C, 0.31, D, 0.43° C,p<0.002). In women, dehydration did not influence the control time course of sweating significantly, nor were these significant body temperature increases during heat exposure. Delay in the onset of sweating in women (C, 18.1, D, 18.7 min) was generally longer than in men (C, 7.8, D, 11.6 min), [F(1, 14)=7.41,p<0.05]. A significant correlation was found between the inertia time of sweating and Tre in both control and dehydration conditions in the men (r=0.81,p<0.01). The rectal temperature increases in men were also related to the inertia time of electrical skin resistance (r=0.83,p<0.01). It is concluded that dehydration affects sweating and body temperature in men more severely than in women.This work was supported in part by the Centre National de la Recherche Scientifique and the Polish Academy of Sciences within the Project 10.4     

The effects of different levels of heat production induced by diathermy and eccentric work on thermoregulation during exercise at a given skin temperature

Summary The thermal responses of two healthy male subjects have been studied at the same mean skin temperature (T _sk ) during negative work, positive work and positive work in which additional heating was induced by diathermy. The results showed that for a given metabolic heat production (M) rectal (T _re ) and oesophageal (T _oes ) temperatures were higher in negative work and positive work with diathermy than normal control experiments. In resting experiments with diathermy, T _oes rose to the same level as when an equal amount of heat was produced metabolically by exercise. In negative work and positive work with diathermy sweat loss (M _sw ) was higher for a given M and T _sk than found for normal exercise, but in all three forms of work the relationship of M _sw to total heat production (H) was identical. During positive work with and without diathermy the differences in M _sw could be accounted for by using a previously developed model of relative sweating rate: %M _sw = – constant + T _re (or T _oes ) + T _sk .In negative work, removal of the difference between predicted and observed %M _sw required the inclusion of a further factor into the equation based on muscle temperature. The results suggest that the core temperature in exercise rises to meet the requirements of heat dissipation mainly by stimulating M _sw and establishing a heat transfer gradient from core to periphery and is not necessarily or uniquely related to M or to the rate of working. The study underlines the usefulness of negative work and diathermy as physiological tools for the further understanding of thermoregulation during exercise.     

Psychomotor retardation and agitation in depression. Relationship to age, sex, and response to treatment

Patients with primary affective disorder who had either psychomotor agitation alone or psychomotor retardation alone were studied. Compared to psychomotor retardation, psychomotor agitation appears to be seen more frequently in women, older patients, and individuals who have a late onset to their illness. In addition, those with agitation alone appeared to have a better and faster response to electroconvulsive therapy.     

Cardiovascular,hormonal, and emotional responses to the TSST in relation to sex and menstrual cycle phase

The prevalence of stress disorders differs between men and women. An understanding of how men and women vary in acute stress responses may help to understand these sex differences. We compared responses to the TSST and a control task in healthy men (N=28) and women tested in two phases (Follicular N=29, Luteal N=23) of the menstrual cycle. Men exhibited greater cortisol responses to stress than women in either phase. Luteal women exhibited the greatest subjective and allopregnanolone responses to stress, whereas follicular women exhibited blunted noradrenaline responses. Partial correlations controlling for group differences revealed that individuals who were most sensitive to the subjective effects of stress exhibited the largest salivary cortisol, noradrenaline, and allopregnanolone responses and the smallest progesterone responses to stress. We discuss our findings in the context of sex differences in the prevalence of stress‐linked disorders.     

Regional differences in the effect of exercise intensity on thermoregulatory sweating and cutaneous vasodilation

To investigate regional body differences in the effect of exercise intensity on the thermoregulatory sweating response, nine healthy male subjects (23.2 ± 0.4 year) cycled at 35, 50 and 65% of their maximal O₂ uptake (V˙O _2max) for 30 min at an ambient temperature of 28.3 ± 0.2 °C and a relative humidity of 42.6 ± 2.4%. Local sweating rate ( m˙_sw) on the forehead, chest, back, forearm and thigh increased significantly with increases in the exercise intensity from 35 to 50% V˙O _2max and from 50 to 65% V˙O _2max (P < 0.05). The mean values for the density of activated sweat glands (ASG) at 50 and 65% V˙O _2max at the five sites were significantly greater than at 35% V˙O _2max. The mean value of the sweat output per gland (SGO) also increased significantly with the increase in exercise intensity (P < 0.05). The patterns of changes in ASG and SGO with an increase in exercise intensity differed from one region of the body to another. Although esophageal temperature (T_es) threshold for the onset of sweating at each site was not altered by exercise intensity, the sensitivity of the sweating response on the forehead increased significantly from 35 to 50 and 65% V˙O _2max (P < 0.05). The threshold for cutaneous vasodilation tend to increase with exercise intensity, although the exercise intensity did not affect the sensitivity (the slope in the relationship T_es vs. percentage of the maximal skin blood flow) at each site. T_es threshold for cutaneous vasodilation on the forearm was significantly higher at 65% V˙O _2max than at either 35 or 50% V˙O _2max, but this was not observed at the other sites, such as on the forehead and chest. These results suggest that the increase in m˙_sw seen with an increasing intensity of exercise depends first on ASG, and then on SGO, and the dependence of ASG and SGO on the increase in m˙_sw differs for different body sites. In addition, there are regional differences in the T_es threshold for vasodilation in response to an increase in exercise intensity.     

The effect of diurnal variation on the regional differences in sweating and skin blood flow during exercise

The aim of the present study was to examine changes in the control of heat-dissipation responses to exercise associated with the diurnal variation in core temperature from the viewpoint of the regional response patterns. We studied seven men during exercise on a cycle ergometer at 100 W for 40 min at 25°C at 0630 (morning) 1630 (evening) hours on 2 separate days. Oesophageal temperature (T _oes), local skin temperature, local sweating rate ( ) on the forehead, back, forearm and thigh, and skin blood flow by laser Doppler flowmeter (LDF) on the back and forearm were measured continuously. TheT _oes at rest was significantly higher in the evening than in the morning, the difference averaging approximately 0.4°C (P < 0.05). TheT _oes thresholds for each site in and that for back in LDF were significantly different between the two times of day (P < 0.05). The change inT _oes thresholds for sweating and vasodilatation for morning and evening were similar toT _oes at rest. Although on the forehead was significantly higher in the morning than in the evening, on the back was significantly higher in the evening than in the morning (P < 0.05). Total local sweating rate ( ) for each site during exercise was significantly higher on the forehead than on the forearm in the morning, and on the back than on the forearm in the evening, respectively (P < 0.05). The results would suggest that the diurnal variation of heat-dissipation responses to exercise is influenced not only by a central controlling mechanism but also by changes in the regional differences.     

Different thermal dependency of cutaneous sympathetic outflow to glabrous and hairy skin in humans

We investigated the effects of ambient temperature on the sudomotor and vasoconstrictor components of skin sympathetic nerve activity (SSNA). The sympathetic traffic was measured by simultaneous microneurographic recording from post-ganglionic nerve fibres in the tibial and the peroneal nerves. When the ambient temperature was raised from 25° C to 34° C, both sudomotor and vasoconstrictor components of SSNA were enhanced in the peroneal nerve but were suppressed in the tibial nerve. The sudomotor and vasoconstrictor sympathetic outflows were elevated in both nerves when the temperature was lowered from 34° C to 18° C. Our results suggested that the sudomotor and the vasoconstrictor components of SSNA are differently modulated by ambient temperature. The difference in sudomotor and vasoconstrictor components of SSNA in the tibial and the peroneal nerves at different ambient temperature may have been responsible for the differences observed in sweating and vasoconstriction in glabrous and hairy skin.     

Oxygen deficit and repayment in submaximal exercise

Oxygen deficit and repayment ratios were investigated at various work loads, intensities and durations. An active baseline was used (walking at 60 m/min) from which deficit and repayment values were calculated. Oxygen uptake (VO₂) and core temperatures were measured in 30 males at baseline and during treadmill running (140 m/min) for randomly assigned durations (0.5 ... 20 min). Measurements were also made during a 30-min recovery period at baseline work. Results indicated: 1) No difference in O₂-repayment between steady-state work and work prior to steady-state (P>0.10). 2) O₂-repayment was independent of work duration (P>0.10). 3) When workload and intensity were controlled, O₂-deficit was not a significant factor in O₂-repayment (P>0.10). 4) Work intensity (workVO₂/VO₂max) was the most significant factor in O₂-repayment accounting for 69% of the variance (r = 0.83,P<0.001). Small increments in core temperature and ventilation were not significant factors in O₂-repayment. When a working baseline is used, the magnitude of O₂-repayment after exercise is independent of the work duration or the attainment of steady state. The extent of O₂-repayment after exercise is mainly dependent upon the physiological intensity of the work and the absolute workload (R = 0.89,P<0.001).