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At least 19 recordsLinked to original sources
PubMed1991

[Studies on the change in the levels of serum ferritin, serum iron and total iron binding capacity caused by aging and sex difference].

Sex difference and aging change of serum ferritin concentration in normal subjects were studied with their relations to serum iron concentration, total iron binding capacity (TIBC) and other hematological parameters. The subjects of this study were the stuff of our hospital (113 males and 330 females) and some old patients without having any diseases of internal medicine (11 males and 23 females), 477 in all. Serum ferritin level was 108.0 +/- 57.8 ng/ml in men and 26.4 +/- 22.7 ng/ml in women, which showed the significant difference between the sexes. In terms of the changes in serum ferritin level by aging, serum ferritin level increased with age from twenties to fifties in the men. On the other hand, it remained low in the women to their forties and its changes by aging were not observed, though it abruptly increased in the women after 50 years of age. The low levels of serum ferritin, iron, transferrin saturation (Fe/TIBC) and hemoglobin of red blood cell were often observed in the women aged from 18 to 45, but rarely found in the women after 50 years of age. According to this fact, the low level of serum ferritin in the young women are considered to be related to the menstruation. Significant correlation between serum ferritin and serum iron or transferrin saturation was shown both in men and women, while that between serum ferritin and hemoglobin of red blood cell was shown only in women.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1975

Blood sugar serum insulin and free fatty acid levels in normal dogs. Sex differences.

Sex influences on blood sugar, serum immunoreactive insulin and free fatty acid levels in normal dogs, basally and during intravenous glucose tolerance tests, were studied. Serum free fatty acid levels were the variable most affected by sex in our study. They were high in males in the post-absorptive condition, with a prompt, sharp suppressibility by combined hyperglycaemia and hyperinsulinaemia, followed by intense, subsequent rebound. Low in fasted females, they were poorly, non-significantly suppressed by glucose administration, and no subsequent rebound was observed. Insulin response was hardly impaired in males in respect to females, and neither blood sugar and serum insulin basal levels, nor the rate of glucose disappearance from blood depended upon sex.

Animals↗
PubMed1992

[Sex difference in free erythrocyte protoporphyrin (FEP) level. II. Sex difference in FEP level in rats exposed to lead].

An experimental study on Donryu rats was primarily carried out to elucidate sex difference in FEP level. Each of 33 male and 33 female rats was divided into 3 groups; that is, control group (5% glucose solution only), low lead dose group (Pb 0.5 mg/kg.BW) and high lead dose group (Pb 5 mg/kg.BW). Lead was injected intraperitoneally once a week for 6 wk. FEP, Ht, urinary coproporphyrin (CP-U), delta-aminolevulinic acid (ALA-U) and porphobilinogen (PBG-U) were determined once every two weeks for 6 wk, and whole blood lead (Pb-B) at the end of the experiment. Mean value of Ht was lower in females than in males throughout the period of the experiment in almost all groups. Pb-B level of all groups and erythrocyte Pb level of high dose group were higher in males than in females. FEP level without lead injection and with low lead exposure was higher in males than in females. By analysis of variance for gain from initial FEP level, only the low lead dose group demonstrated a significant sex difference (p less than 0.01); the female group tended to increase, while the male group maintained a constant level. Furthermore, FEP/Pb-B ratio in females was higher than in males only for the high dose group. The changes in ALA-U in male and female rats were comparable to those in FEP. Unlike FEP and ALA-U, CP-U level was higher in males than in females only for the high lead dose group. In this study using rats, sex difference in FEP level was different from that in human.(ABSTRACT TRUNCATED AT 250 WORDS)

Aminolevulinic Acid↗
PubMed1992

[Sex difference in free erythrocyte protoporphyrin (FEP) level. I. Sex difference in FEP level in healthy rural residents].

FEP and other hematological parameters were measured in 157 healthy rural residents (98 females and 59 males). The mean FEP in females was higher than in males (p less than 0.05); mean +/- SD = 62.98 +/- 19.36 and 54.57 +/- 21.20 micrograms/dl.pcv, respectively, although both of the means were within normal limits. There was no significant sex difference in erythrocyte ALA-D activity. Whole blood lead (Pb-B) level in females showed a tendency to be lower than in males, but there was no significant sex difference in erythrocyte lead level. The mean value of hematocrit (Ht), hemoglobin (Hb) and iron in serum (Fe-S) were lower in females than in males (p less than 0.01). Serum GOT and GPT level tended to be lower in females than in males (0.05 less than p less than 0.1). There was hardly any significant relationship between Pb-B and each parameter of lead exposure, because the subjects in this study were only rural residents with no occupational lead exposure and with their Pb-B levels being extremely low. As for the parameters of anemia, Fe-S was positively correlated with Ht and Hb level and negatively correlated with FEP level. By sex, Fe-S was correlated with Ht and FEP level only in females. As for the possible reasons why FEP level in females in higher than in male, women tended to have iron-deficiency induced by blood loss due to menstruation, pregnancy, and difference in dietary pattern from males.

Adult↗
PubMedDate not supplied

[Lipid metabolism of neonatally thymectomized rats of different sexes].

Content of cholesterol, its esters, total beta-lipoproteins and free fatty acids was increased in blood serum of rats, subjected to thymectomia after birth. The distinct sex variations were found in alterations of these patterns. Content of cholesterol was increased only in thymectomized males at the age of 3 months; content of beta-lipoproteins in males was elevated earlier and to higher level as compared wtih females. Alteration in content of blood serum lipids did not depend on manifestations of exhaustion syndrome (typical consequence of neonatal thymectomia) but it was related to ablation of thymus; this suggests that thymus participates in regulation of lipid metabolism. Sex differences in alterations of lipid metabolism patterns enabled to assume the existence of endocrine interrelations between thymus and sex glands.

Animals↗
PubMed1978

[Blood and cardiac cholinesterase activity in rats of different sexes and ages during muscle loading and hypokinesia].

The activity of acetylcholinesterase (Ache) and butyrilcholinesterase (Bche) in the blood and the heart of 3 and 13-month old control male rats is considerably lower than in female rats. In old rats (25 months) no sex differences in the Ache and Bche were revealed in the heart. In 3 and 13-month old male and female rats, under conditions of muscular exercises, the Ache and Bche activity is lower, and in hypokinetic male rats--higher than that in respective control animals. In all the rats, irrespective of sex, age and motor conditions, the Ache and Bche activity tended to decrease, in direction from the sino-atrial node to the heart apex.

Acetylcholinesterase↗
PubMed1991

Dopamine content and metabolism in mesencephalic and diencephalic cell cultures: sex differences and effects of sex steroids.

Sexual differentiation of dopaminergic neurons was studied in gender-specific cultures. Dissociated cell cultures were prepared from di- or mesencephalon of gestational day 14 rat embryos and raised in the absence or presence of 17 beta-estradiol or testosterone for up to 13 days in vitro (DIV). Developmental profiles of levels of dopamine (DA) and metabolites as well as capacity for vesicular storage of the transmitter were determined by HPLC. Tyrosine hydroxylase-immunoreactive (TH-IR) neurons were counted. Higher levels of DA were measured in female than in male cultures of both brain regions. In mesencephalic cultures, the differences in DA levels were fully accounted for by sex differences in numbers of TH-IR cells, whereas no sex differences in cell numbers were found in diencephalic cultures. Dihydroxyphenylacetic acid (DOPAC) levels and vesicular storage capacity matured faster in mesencephalic than in diencephalic cultures, but no sex differences were observed. Homovanillic acid (HVA) could not be detected except in 13-DIV mesencephalic cultures. Hormonal treatment did not erase sexual differentiation of dopaminergic neurons. Irrespective of the gender, however, both steroids decreased DA and DOPAC contents in diencephalic cultures but not in mesencephalic cultures. It is proposed that sexual differentiation of dopaminergic systems proceeds in a region-specific fashion and that neurogenesis and development of various parameters of dopaminergic activity may be differentially affected. Sexual differentiation of dopaminergic neurons may be initiated independently of the action of gonadal steroid hormones and may subsequently be modified by differences in hormonal environment.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1991

Does the gender relevance of the stressor influence sex differences in psychophysiological responses?

Sex differences in psychophysiological responses to stress may be important to understanding sex differences in risk for coronary heart disease. This investigation tested the hypothesis that the gender relevance of the stressor influences the extent of sex differences in cardiovascular, neuroendocrine, and lipid responses during stress. Participants performed two tasks that were described as masculine oriented, feminine oriented, or not gender relevant. Although these descriptions influenced the participants' perceptions of the tasks, they did not influence the extent of sex differences in physiological responses in a manner consistent with the study hypothesis. Future directions for research are discussed regarding sex differences in psychophysiological responses.

Achievement↗
PubMed1991

[Sex differences in schizophrenic diseases].

Sex differences in schizophrenic diseases have been known for a long time but have also been subject to long-term neglect by psychiatric epidemiological research, although a study of these sex differences could, in our opinion, yield valuable pointers to pathogenic factors involved in this group of diseases the aetiology of which still awaits clarification. For this reason we initiated large-scale investigations focussed on this topic. The paper presented here discusses a few initial results, basing on data of Mannheim and National Danish Case Records and on our own study on schizophrenia, the latter being a representative record of 392 patients hospitalised for the first time in the Rhine-Neckar region and the eastern part of the Palatinate. First of all, sex differences at the age at which the disease appeared for the first time, were studied while paying close attention to artifacts and other, usually neglected methodical error sources. The difference in the average age of the sexes at first hospitalisation was confirmed, and also--using an instrument specially developed for that purpose--at the onset of the disease. At the time the first signs of the disease are noticed and the first schizophrenic symptoms become apparent, men are about 3 to 4 years younger than women. On the other hand, the cumulative lifetime risk--calculated up to 60 years of age--seems to be the same for both sexes. It appears that there are no sex differences in the pattern of symptoms of the disease at the time of initial hospital admittance, in respect of both the most common and the characteristic signs and symptoms. There were significant although quantitatively not very great differences in respect of patient behaviour which displays socially positive aspects somewhat more often in women and socially negative ones distinctly more often in men. In respect of the course of the disease we could not find any marked sex differences over a period of 10 years after onset of the disease; however, this is presently based only on the Danish case record data and on criteria of the course of the disease, such as number and duration of inpatient treatments.

Adolescent↗
PubMed1990

The vocal motor neurons of Xenopus laevis: development of sex differences in axon number.

Sex differences in the number of muscle fibers in the larynx of clawed frogs (Xenopus laevis) develop after metamorphosis. In order to examine possible contributions of neural innervation to this process, we prepared sections of the laryngeal nerve from tadpole stage 56, when the sexes can first be distinguished, through adulthood, and counted axons on electron micrographs. The adult number of axons is achieved by a sexually differentiated pattern of axonal addition and loss. Axon numbers are high at tadpole stage 56 and equal for males and females; thereafter, males have more axons. Sex differences are most pronounced at tadpole stage 62 because between stages 59 and 62 the number of laryngeal axons in males increases by an average of 119 per nerve. Ultrastructural evidence is congruent with the hypothesis that new axons are added to the laryngeal nerve between tadpole stages 56 and 62. The loss of axons from the laryngeal nerve is greater for females than for males. Between tadpole stages 56 and adulthood, overall axon number decreases by 47% in males and by 64% in females. Signs of axonal degeneration are present in both sexes before metamorphosis but are rare at juvenile or adult stages. The numbers of axons in juvenile frogs do not differ from those in adults and continue to be greater in males than in females. In contrast to the amount of axon addition and loss, the timing of axon loss and the percentage of myelinated axons is the same for males and females throughout development. Thus sex differences in the innervation of laryngeal muscle originate before metamorphosis and could contribute to the marked sex differences in muscle fiber addition that occur thereafter.

Animals↗
PubMed1991

Sex differences in androgen receptors and aromatase activity in microdissected regions of the rat brain.

Males are generally more responsive than females to the behavioral and neuroendocrine actions of androgens. The present experiments were performed to determine whether these differences may result from sex differences in the number of androgen receptors (AR) in specific brain areas. For this reason, AR binding was compared in both cytosol (ARc) and cell nuclear KCl extracts (ARn) from microdissected brain regions of gonadectomized male and female rats treated with doses of testosterone (T) that produced equivalent physiological circulating androgen levels. In addition, microsomal aromatase activity was measured as a biochemical index of tissue responsiveness to T, since estrogen formation in certain brain areas is regulated by androgen. One week after exogenous T administration, males exhibited significantly higher levels of ARn than females in the bed nucleus of the stria terminalis, periventricular preoptic area, and ventromedial nucleus. Males also had significantly higher aromatase levels in these same areas plus the medial preoptic nucleus and anterior hypothalamus. There were no significant differences in ARn concentrations in eight other nuclei that were examined for significant sex differences in ARc levels observed under these experimental conditions. When ARc levels were compared in untreated gonadectomized male and female rats, males had greater levels of ARc in the bed nucleus of the stria terminalis only, indicating that new receptor synthesis may be responsible for the sex differences observed in T-treated rats. These results suggest that sex differences in neural responsiveness to androgens may be due in part to sex differences in ARn occupation in specific brain regions.

Animals↗
PubMed1992

Sex differences in hypokalaemic and electrocardiographic effects of inhaled terbutaline.

BACKGROUND: Gender differences in the chronotropic effects of infused isoprenaline have previously been described. The aim of the present study was to investigate possible gender differences in hypokalaemic, chronotropic, and electrocardiographic effects of inhaled terbutaline. METHODS: Twenty healthy volunteers (10 female) were recruited (mean age 24 years for women (F) and 22 years for men (M). Subjects were given either inhaled terbutaline 5 mg or placebo in single blind, randomised crossover fashion and the following measurements were made for four hours after inhalation: (a) serum potassium concentration; (b) heart rate; (c) electrocardiographic sequelae (T wave amplitude, Q-Tc interval). The effects of terbutaline on serum potassium was chosen as the primary end point for detecting a 0.3 mmol/l difference between sexes, with a beta error of 0.2 and alpha set at 0.05. RESULTS: The hypokalaemic effects of terbutaline were significantly greater in women, the potassium results (means and 95% CI) being as follows: lowest potassium concentration--F 3.12 (2.96-3.28) mmol/l v M 3.65 (3.49-3.81) mmol/l; percentage change from baseline at one hour--F 15.4% (11.5-19.3%) v M 8.5% (4.6-12.3%); average potassium concentration during the four hours--F 3.39 (3.33-3.46) mmol/l v M 3.78 (3.72-3.85) mmol/l. There was no significant regression between body weight and the potassium response to terbutaline. There were also significant sex differences for T wave, Q-Tc, and heart rate response. The percentage fall in T wave amplitude 30 minutes after terbutaline was: F 44.6% (32.1-57.0%) v M 22.4% (9.9-34.8%). CONCLUSIONS: Women are more sensitive to the hypokalaemic, chronotropic, and electrocardiographic sequelae of inhaled terbutaline.

Administration, Inhalation↗
PubMed1976

Galton and sex differences: an historical note.

The psychological study of sex differences is a special area of interest within differential psychology. Differential psychology was launched as a scientific field of research in the latter half of the nineteenth century by Sir Francis Galton. Galton's early research on sex differences in psychological traits gives him the distinction of being the "father" of the modern study of sex differences. Galton's empirical findings and his interpretation of sex differences were heavily influenced by his Victorian sexist attitudes. The early history of the modern study of sex differences exemplifies the intimate relation between facts and values.

England↗
PubMed1977

Sex differences in WAIS item performance.

Although the WAIS IQ scores of males and females differ only negligibly, significant sex differences do exist on many WAIS subtests. The purpose of the present investigation was to identify any WAIS items within these subtests that showed reliable sex differences. Within a cross-validation methodology that employed 521 adults (264 males; 257 females), 21 items were found to show reliable sex differences. A reanalysis by age groups provided similar results. The nature of the items was discussed, and an index of stereotyped sex-role experiences was proposed.

Adult↗
PubMed2026

Sex differences in the genetic and causal relationships between depression, smoking, and alcohol use: the role of socioeconomic status.

Major depressive disorder (MDD), smoking, and drinking frequently co-occur, with evidence suggesting these relationships may differ by sex. However, the direction of causality and the extent of sex-specific associations remain unclear. We investigated sex-specific genetic relationships between MDD and substance use phenotypes using genome-wide association studies (GWAS) from the UK Biobank and publicly available sex-stratified GWAS for MDD and problematic alcohol use (PAU). Causal effects were assessed using bidirectional, sex-stratified Mendelian randomization (MR). We further applied multivariable MR (MVMR) to evaluate the influence of socioeconomic status (SES). Genetic correlation analyses indicated significant shared genetic architecture between MDD and all substance use traits in sex-combined GWAS. In sex-specific analyses, the correlation between cigarettes per day and MDD was significantly stronger in females, and drinks per week were correlated with MDD only in females. MR analyses showed that genetic liability to MDD increased the risk of smoking initiation and PAU in females, and was associated with reduced alcohol drinking frequency in males. In contrast, no tested substance use trait showed evidence of a causal effect on MDD in either sex. MVMR adjusting for SES attenuated the association between MDD and smoking initiation. The effect on PAU in females remained. In males, the negative association between MDD and drinking frequency became non-significant after SES adjustment. These findings reveal sex-specific genetic and causal relationships between smoking, drinking, and MDD, and highlight the role of SES as a potential confounder. Incorporating sex and socioeconomic context is critical when examining these associations.

Humans↗
PubMed1991

[Development of behavior and sex differences in infants; with reference to the formation of sex role].

In order to observe the formation of sex role, an investigation was made on the development of behavior and sex differences in infants aged 1 to 6 at Fukuoka-city. The present study consisted of questionnaire on behavior of daily living and breeding, block construction test and coloring a drawing test. The parents instructed their infants to become masculine for males and feminine for females on the basis of traditional view. No sex differences were observed in construction ability of infants aged 4. Favorite colors were different according to sex.

Age Factors↗