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Sex Differences (sex + difference)
Kinds of Sex Differences Selected AbstractsSEX DIFFERENCES IN THE PREFERENCE FOR PLACE OF DEATH IN COMMUNITY-DWELLING ELDERLY PEOPLE IN JAPANJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 2 2008Miyako Yamasaki MD No abstract is available for this article. [source] A PRELIMINARY EXAMINATION OF SEX DIFFERENCES IN TACTILE INTERACTIONS AMONG JUVENILE ATLANTIC SPOTTED DOLPHINS (STENELLA FRONTALIS)MARINE MAMMAL SCIENCE, Issue 4 2007J. Daisy Kaplan First page of article [source] A Sex Difference by Item Difficulty Interaction in Multiple-Choice Mathematics Items Administered to National Probability SamplesJOURNAL OF EDUCATIONAL MEASUREMENT, Issue 1 2001John Bielinski A 1998 study by Bielinski and Davison reported a sex difference by item difficulty interaction in which easy items tended to be easier for females than males, and hard items tended to be harder for females than males. To extend their research to nationally representative samples of students, this study used math achievement data from the 1992 NAEP, the TIMSS, and the NELS:88. The data included students in grades 4, 8, 10, and 12. The interaction was assessed by correlating the item difficulty difference (bmale, bfemale) with item difficulty computed on the combined male/female sample. Using only the multiple-choice mathematics items, the predicted negative correlation was found for all eight populations and was significant in five. An argument is made that this phenomenon may help explain the greater variability in math achievement among males as compared to females and the emergence of higher performance of males in late adolescence. [source] Sex Differences in Feeding Activity Results in Sexual Segregation of Feral GoatsETHOLOGY, Issue 5 2008Robin I. M. Dunbar Sexual segregation is common in ungulates. We show, in a high latitude population of feral goats where behavioural synchrony and fission rates have been shown to be the best explanation for segregation, that it is differences explicitly in the feeding time requirements of the two sexes (but not those for other activities) that best explains the variations in monthly frequencies of segregation. However, this effect is less marked during winter months when short day length forces the time budgets of the two sexes to converge. We argue that the various explanations for segregation can best be interpreted as separate factors in a multivariate model in which species- and habitat-specific weightings influence the relative importance of these variables, and thus the likelihood that segregation will occur. [source] Sex Differences in Infants' Ability to Represent Complex Event SequencesINFANCY, Issue 3 2004Amy Schweinle Prior research suggests that when very simple event sequences are used, 4.5-month-olds demonstrate the ability to individuate objects based on the continuity or disruption of their speed of motion (Wilcox & Schweinle, 2003). However, infants demonstrate their ability to individuate objects in an event-monitoring task (i.e., infants must keep track of an ongoing event) at a younger age than in an event-mapping task (i.e., infants must compare information from 2 different events). The research presented here built on these findings by examining infants' capacity to succeed on an event-mapping task with a more complex event sequence to determine if the complexity of the event interferes with their ability to form summary representations of the event, and, in short, individuate the objects. Three experiments were conducted with infants 4.5 to 9.5 months of age. The results indicated that (a) increasing the complexity of the objects' trajectories adversely affected infants' performance on the task, and (b) boys were more likely to succeed than girls. These findings shed light on how representational capacities change during the first year of life and are discussed in terms of information processing and representational capabilities as well as neuro-anatomical development. [source] Sex Differences in the Effect of Heart Rate on Mortality in the ElderlyJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2003Gila Perk MD Objectives:, To examine the association between heart rate and mortality risk in the elderly. Design:, Longitudinal cohort. Setting:, Outpatient. Participants: Four hundred twenty-two people, aged 70 upon entry, were surveyed and followed for 6 years. Measurements: Pulse rate was measured manually, while sitting and standing, and heart rate was measured from electrocardiogram recordings. The population was divided into quartiles of heart rate, with the top quartile comprising those with heart rate greater than 77 beats per minute (bpm) and the bottom quartile those with heart rate less than 60 bpm. Results: After controlling for possible confounders, there was a clear correlation (r) between heart rate and all-cause mortality in elderly women (r=0.25, P=.0003). The correlation in women was observed using the three different methods for measuring heart rate. Heart rate was associated with all-cause and cardiovascular mortality. There was no relationship between heart rate and level of exercise or smoking status. In multiple regression analysis, the increased risk of death in the women was independent of previous cardiovascular or cerebrovascular disease, hypertension, anemia, congestive heart failure, smoking, and level of exercise or activities of daily living (relative odds ratio (ROR)=3.37, 95% confidence interval (CI)=0.96,11.8). When women using beta-blockers were excluded, this relationship became even stronger (ROR=8.5, 95% CI=1.19,60.1). Conclusion: Elevated heart rate is related to increased mortality in elderly women, thus representing a simple index of general health status in this population. Elevated heart rate did not predict mortality in elderly men. [source] Sex Differences in Salivary Cortisol Levels Following Naltrexone Administration,JOURNAL OF APPLIED BIOBEHAVIORAL RESEARCH, Issue 2 2000Laura Cousino Klein Effects of endogenous opioid peptide blockade by naltrexone on salivary Cortisol levels were examined in healthy men (n= 8) and women (n= 6). Participants received naltrexone (100 mg) during one laboratory session and a placebo pill during another session. Drug order was counterbalanced across participants. Saliva samples were collected 24 hr after each pill was administered. Among women, salivary Cortisol levels significantly increased following naltrexone administration compared with a placebo pill. Naltrexone administration did not alter salivary Cortisol levels in men. Results suggest sex differences in neuroendocrine sensitivity to opioid blockade, a finding that may hold significance with regard to the treatment of alcohol addiction with naltrexone. [source] The Structural and Hormonal Basis of Sex Differences in Peak Appendicular Bone Strength in Rats,,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 1 2003Bom-Taeck Kim Abstract To identify the structural and hormonal basis for the lower incidence of fractures in males than females, sex differences in femoral mid-shaft geometry and breaking strength were studied in growth hormone (GH)-replete and -deficient male and female rats. Sexual dimorphism appeared during growth. Cortical thickening occurred almost entirely by acquisition of bone on the outer (periosteal) surface in males and mainly on the inner (endocortical) surface in females. By 8 months of age, males had 22% greater bone width and 33% greater breaking strength than females. Gonadectomy (Gx) at 6 weeks reduced sex differences in bone width to 7% and strength to 21% by halving periosteal bone formation in males and doubling it in females. Gx had no net effect on the endocortical surface in males but abolished endocortical bone acquisition in females. GH deficiency halved periosteal bone formation and had no net effect on the endocortical surface in males, but abolished bone acquisition on both surfaces in females, leaving males with 17% greater bone width and 44% greater breaking strength than females. Sex hormone deficiency produces greater bone fragility in males than females by removing a stimulator of periosteal growth in males and removing an inhibitor of periosteal growth in females. GH deficiency produces less bone fragility in males than females because males retain androgen-dependent periosteal bone formation while bone acquisition on both surfaces is abolished in females. Thus, periosteal growth is independently and additively stimulated by androgens and GH in males, inhibited by estrogen, and stimulated by GH in females. The hormonal regulation of bone surfaces establishes the amount and spatial distribution of bone and so the sexual dimorphism in its strength. [source] Sex Differences and the Roles of Sex Steroids in Apoptosis of Sexually Dimorphic Nuclei of the Preoptic Area in Postnatal RatsJOURNAL OF NEUROENDOCRINOLOGY, Issue 4 2009S. Tsukahara The brain contains several sexually dimorphic nuclei that exhibit sex differences with respect to cell number. It is likely that the control of cell number by apoptotic cell death in the developing brain contributes to creating sex differences in cell number in sexually dimorphic nuclei, although the mechanisms responsible for this have not been determined completely. The milieu of sex steroids in the developing brain affects sexual differentiation in the brain. The preoptic region of rats has two sexually dimorphic nuclei. The sexually dimorphic nucleus of the preoptic area (SDN-POA) has more neurones in males, whereas the anteroventral periventricular nucleus (AVPV) has a higher cell density in females. Sex differences in apoptotic cell number arise in the SDN-POA and AVPV of rats in the early postnatal period, and an inverse correlation exists between sex differences in apoptotic cell number and the number of living cells in the mature period. The SDN-POA of postnatal male rats exhibits a higher expression of anti-apoptotic Bcl-2 and lower expression of pro-apoptotic Bax compared to that in females and, as a potential result, apoptotic cell death via caspase-3 activation more frequently occurs in the SDN-POA of females. The patterns of expression of Bcl-2 and Bax in the SDN-POA of postnatal female rats are changed to male-typical ones by treatment with oestrogen, which is normally synthesised from testicular androgen and affects the developing brain in males. In the AVPV of postnatal rats, apoptotic regulation also differs between the sexes, although Bcl-2 expression is increased and Bax expression and caspase-3 activity are decreased in females. The mechanisms of apoptosis possibly contributing to the creation of sex differences in cell number and the roles of sex steroids in apoptosis are discussed. [source] Sex Differences in Oestrogen-Induced p44/42 MAPK Phosphorylation in the Mouse Brain In VivoJOURNAL OF NEUROENDOCRINOLOGY, Issue 8 2006K. Barabás In addition to the classical direct genomic mechanisms of action, oestrogen also exerts poorly understood, nonclassical effects on the signalling system in neurones. In the present study, we investigated whether sex differences exist in gonadectomy- and oestrogen-induced effects on p44/42 mitogen-activated protein kinase (MAPK) phosphorylation in specific brain regions of mice. We demonstrate that MAPK immunoreactivity was not altered by gonadectomy or oestrogen treatment in either sex. However, we show that the level of phosphorylated MAPK (pMAPK) within the anteroventral periventricular nucleus (AVPV) was consistently higher in males than females irrespective of gonadal steroid hormone status. In addition, gonadectomy was found to decrease pMAPK immunoreactivity within the piriform cortex of males. Oestrogen increased pMAPK immunoreactivity in the medial preoptic area and AVPV of females, but failed to have the same effect in male mice. Overall, these results demonstrate a marked sex difference in oestrogen-induced alteration of MAPK phosphorylation in the brain in vivo. [source] Sex Differences in the Distribution and Abundance of Androgen Receptor mRNA-Containing Cells in the Preoptic Area and Hypothalamus of the Ram and EweJOURNAL OF NEUROENDOCRINOLOGY, Issue 12 2004C. J. Scott Abstract Rams and ewes show a negative-feedback response to peripheral treatment with testosterone, with both sexes having a similar degree of suppression in luteinizing hormone (LH) secretion during the breeding season. At least part of the action of testosterone to suppress gonadotropin-releasing hormone/LH secretion is exerted via interaction with an androgen receptor. The distribution of androgen receptor-containing cells in the hypothalamus has been described for the ram, but similar studies have not been performed in the ewe. In the present study, we tested the hypothesis that levels of androgen receptor mRNA expression in the preoptic area and hypothalamus would be similar in rams and ewes. Perfusion-fixed brain tissue was obtained from adult Romney Marsh ewes (luteal phase) and rams during the breeding season (n = 4/sex). Androgen receptor mRNA expression was quantified in hypothalamic sections by in situ hybridization using an 35S-labelled riboprobe and image analysis. Hybridizing cells were found in the medial preoptic area, bed nucleus of the stria terminalis, anterior hypothalamic area, ventromedial nucleus, arcuate nucleus and premamillary nucleus. The level of androgen receptor mRNA expression was higher in rams than ewes in the rostral preoptic area, caudal preoptic area and rostral portion of the bed nucleus of the stria terminalis, with no sex difference in other regions. The preoptic area and bed nucleus of the stria terminalis are important for reproductive behaviour and the sex differences in androgen receptor mRNA expression at these levels may relate to this. The high level of androgen receptor mRNA expression in the basal hypothalamus, with no sex difference, is consistent with the role of this region in the regulation of gonadotropin secretion. [source] Sex Differences in the BrainJOURNAL OF NEUROENDOCRINOLOGY, Issue 7 2000Article first published online: 24 DEC 200 [source] Sex Differences in Ethanol-Induced Hypothermia in Ethanol-Naïve and Ethanol-Dependent/Withdrawn RatsALCOHOLISM, Issue 1 2009Anna N. Taylor Background:, Human and animal findings indicate that males and females display major differences in risk for and consequences of alcohol abuse and alcoholism. These differences are in large part mediated by sex-specific hormonal environments. Gonadal and adrenal secretory products are known to modulate the neurobehavioral responses of ethanol (EtOH) dependence and withdrawal. However, the effects of these steroids on physiological adaptations, such as thermoregulation, are less well established. To study the role of sex-related hormones in mediating sex differences in the hypothermic response to acute challenge with EtOH, we compared the EtOH-induced hypothermic responses of EtOH-naïve male and female rats and EtOH-dependent (on the third day of withdrawal) male and female rats before (intact) and after depletion of all gonadal and adrenal steroids by gonadectomy (GDX) with or without adrenalectomy (ADX). Methods:, Intact and GDX male and female rats, with or without ADX, were fed an EtOH-containing liquid diet for 15 days while control (EtOH-naïve) rats were pairfed the isocaloric liquid diet without EtOH or fed normal rat chow and water. On the third day of withdrawal from the EtOH diet we tested the hypothermic response to EtOH challenge (1.5 g/kg BWt, ip). Blood alcohol content (BAC) and corticosterone (CORT) content were analyzed in a separate series of intact and GDX males and females with and without ADX in response to the EtOH challenge. Results:, Ethanol-induced hypothermia was significantly greater and its duration significantly longer in intact males than females when subjects were EtOH-naïve. EtOH-induced hypothermia was significantly greater in intact females than males by the third day of withdrawal from EtOH dependence. GDX in males significantly shortened the duration of the hypothermic response and tended to blunt EtOH-induced hypothermia while response duration was significantly extended by GDX in females that tended to enhance EtOH-hypothermia. EtOH-induced hypothermia was significantly enhanced and its duration significantly lengthened by combined GDX and ADX in EtOH-naïve and -withdrawn males and by combined GDX and ADX in EtOH-naïve but not EtOH-withdrawn females. These differential EtOH-induced hypothermic responses did not appear to be caused by differences in EtOH handling among the groups. The absence of adrenal activation by EtOH in the GDX,ADX males and females contributes to their enhanced EtOH-induced hypothermic responses. Conclusions:, These results implicate the direct and indirect effects of removal of gonadal and adrenal secretory products as mediators of the thermoregulatory actions of EtOH. [source] Impact of Sex: Determination of Alcohol Neuroadaptation and ReinforcementALCOHOLISM, Issue 2 2006Kristine M. Wiren This article represents the proceedings of a symposium at the Research Society on Alcoholism meeting in Santa Barbara, California. The organizers/chairs were Kristine M. Wiren and Deborah A. Finn. Following a brief introduction by Deborah Finn, the presentations were (1) The Importance of Gender in Determining Expression Differences in Mouse Lines Selected for Chronic Ethanol Withdrawal Severity, by Kristine M. Wiren and Joel G. Hashimoto; (2) Sex Differences in Ethanol Withdrawal Involve GABAergic and Stress Systems, by Paul E. Alele and Leslie L. Devaud; (3) The Influence of Sex on Ethanol Consumption and Reward in C57BL/6 Mice, by Kimber L. Price and Lawrence D. Middaugh; and (4) Sex Differences in Alcohol Self-administration in Cynomolgus Monkeys, by Kathleen A. Grant. [source] Health Perception and Health Care Access: Sex Differences in Behaviors and AttitudesAMERICAN JOURNAL OF ECONOMICS AND SOCIOLOGY, Issue 2 2010Marta Gil-Lacruz This article analyzes the link between men's and women's perceptions of health and the demand for health goods and services. The study examines access to the health care system in a community characterized by social and economic variance. The data have been taken from a health survey carried out in a suburb of the city of Zaragoza in Spain. The sample (1,032 people over the age of 15) was selected according to specifications of sex, age, and place of residence. The sample shows a confidence interval of 95.5 percent with a ±3 margin of error. Descriptive and inferential statistical techniques are used. Sex differences are reflected in social conditions, lifestyles, health perception, and health care behaviors. The research describes how differences in health attitudes can be contextualized by the neighborhood. The results of this type of research are essential for the design of preventive strategies that are better adapted to need. [source] Mars and Venus at Twilight: A Critical Investigation of Moralism, Age Effects, and Sex DifferencesPOLITICAL PSYCHOLOGY, Issue 1 2003Daniel Aldrich Analysts have long sought to understand whether women and men have different ethical orientations. Some researchers have argued that women and men consistently make fundamentally different ethical judgments, especially of corruption; others have found no such disparities. This study considered whether an individual's age may also play a role in determining his or her moral judgment. A statistical investigation of interactive effects between gender and age in a nationally representative data set from Japan shows that this interaction functions better as a predictor of moralism than do education or gender alone. Older individuals of both sexes were found to have similar strict moral perceptions; as women and men age, their ethical judgments converge. [source] Ethnic and Sex Differences in Ownership of Preventive Health Equipment Among Rural Older Adults With DiabetesTHE JOURNAL OF RURAL HEALTH, Issue 4 2007Ronny A. Bell PhD ABSTRACT:,Context:Diabetes self-management is important for achieving successful health outcomes. Different levels of self-management have been reported among various populations, though little is known about ownership of equipment that can enhance accomplishment of these tasks.Purpose:This study examined diabetes self-management equipment ownership among rural older adults.Methods:Participants included African American, American Indian, and white men and women 65 years of age and older. Data included equipment ownership overall and by ethnicity and sex across diabetes self-management domains (glucose monitoring, foot care, medication adherence, exercise, and diet). Associations between equipment ownership and demographic and health characteristics were assessed using logistic regression.Findings:Equipment ownership ranged from 85.0% for blood glucose meters to less than 11% for special socks, modified dishes, and various forms of home exercise equipment. Equipment ownership was associated with ethnicity, living arrangements, mobility, poverty status, and formal education.Conclusions:Rural older adults with diabetes are at risk because they lack equipment to perform some self-management tasks. Providers should be sensitive to and assist patients in overcoming this barrier. [source] Sex Differences in Outcomes of Sinus Surgery,THE LARYNGOSCOPE, Issue 7 2006Sabrina Mendolia-Loffredo MS Abstract Purpose: Sex has been demonstrated to affect outcome in many diseases. Our current aim is to investigate the relationship between sex and outcomes of endoscopic sinus surgery (ESS) in patients with chronic rhinosinusitis (CRS). Methods: Forty-four males and 73 females undergoing ESS for CRS with a mean follow-up of 1.4 years were evaluated prospectively. Computed tomography (CT), endoscopy, and quality of life (QOL) assessment was performed. Univariate analyses were performed to evaluate whether sex was predictive of outcome. Multiple logistic regression analysis was performed to evaluate sex association with patient factors predictive of outcome. Results: Although no sex differences in CT and endoscopy were observed (CT, P = .107 and endoscopy, P > .1), females consistently scored worse than males on disease-specific QOL pre- and postoperatively. Importantly, there was no effect of sex on improvement/change scores for the QOL instruments. Predictive Models and Multiple Logistic Regression Analysis: Sex was not found to be predictive of QOL or endoscopic outcome. Female sex was, however, associated with acetylsalicylic acid (ASA) intolerance and depression, both factors that have been associated with poorer outcome. Conclusion: Despite similarities in objective disease measures, females report significantly worse QOL scores pre- and postoperatively. Postoperative improvement did not differ by sex, nor was sex predictive of postoperative outcome. Sex differences in QOL reflect sex differences in ASA intolerance and depression, both more prevalent in females. [source] Racial and Sex Differences in Emergency Department Triage Assessment and Test Ordering for Chest Pain, 1997,2006ACADEMIC EMERGENCY MEDICINE, Issue 8 2010Lenny López MD ACADEMIC EMERGENCY MEDICINE 2010; 17:801,808 © 2010 by the Society for Academic Emergency Medicine Abstract Objectives:, This study assessed whether sociodemographic differences exist in triage assignment and whether these differences affect initial diagnostic testing in the emergency department (ED) for patients presenting with chest pain. Methods:,A nationally representative ED data sample for all adults (,18 years) was obtained from the National Hospital Ambulatory Health Care Survey of EDs for 1997,2006. Weighted logistic regression was used to examine the associations between race and presenting symptom, triage assignment, and test ordering, adjusting for patient and hospital characteristics. Results:, Over 10 years, an estimated 78 million visits to the ED presented with a complaint of chest pain. Of those presenting with chest pain, African Americans (odds ratio [OR] = 0.70; 99% confidence interval [CI] = 0.53 to 0.92), Hispanics (OR = 0.74; 99% CI = 0.51to 0.99), Medicaid patients (OR = 0.72; 99% CI = 0.54 to 0.94), and uninsured patients (OR = 0.65; 99% CI = 0.51 to 0.84) were less likely to be triaged emergently. African Americans (OR = 0.86; 99% CI = 0.70 to 0.99), Medicaid patients (OR = 0.70; 99% CI = 0.55 to 0.88), and uninsured patients (OR = 0.70; 99% CI = 0.55 to 0.89) were less likely to have an electrocardiogram (ECG) ordered. African Americans (OR = 0.69; 99% CI = 0.49 to 0.97), Medicaid patients (OR = 0.67; 99% CI = 0.47 to 0.95), and uninsured patients (OR = 0.66; 99% CI = 0.44 to 0.96) were less likely to have cardiac enzymes ordered. Similarly, African Americans and Hispanics were less likely to have a cardiac monitor and pulse oximetry ordered, and Medicaid and uninsured patients were less likely to have a cardiac monitor ordered. Conclusions:, Persistent racial, sex, and insurance differences in triage categorization and basic cardiac testing exist. Eliminating triage disparities may affect "downstream" clinical care and help eliminate observed disparities in cardiac outcomes. [source] Sex Differences in Perceived Family Functioning and Family Resources in Hong Kong Families: Implications for Social Work PracticeASIAN SOCIAL WORK AND POLICY REVIEW, Issue 3 2009Joyce L.C. Ma Although enhancing family functioning has become a rising concern of social workers in Chinese contexts such as Hong Kong, little has been known on perceived family functioning and family resources. To fill in this knowledge gap, this article reports part of the results of a telephone survey conducted in Hong Kong, aiming to identify the sex differences in these two areas. The results of the study have shown that Chinese women perceived better affective involvement, one of the crucial indicators of family functioning, than Chinese men. However, among the different family resources, men rated better physical and mental well-being whereas women's social connection was stronger than men's. Further analysis have shown that the linkage of three family resources (namely stress coping efficacy, time spent with family and income) to perceived family functioning was statistically significant irrespective of genders. Implications of this study for social work practice are discussed at the end of the article. [source] Prevalence and handedness correlates of traumatic injuries to the permanent incisors in 13,17-year-old adolescents in Erzurum, TurkeyDENTAL TRAUMATOLOGY, Issue 5 2003Varol Canakci Abstract ,,,The objectives of the present study were to explore the relationship between dental trauma and handedness, and to assess the prevalence of traumatic injuries to the permanent incisors of 13,17-year-old patients, seeking treatment for various dental conditions in Erzurum, Turkey. A questionnaire focusing on handedness was administered to these patients. Handedness was assessed by the Edinburgh Handedness Inventory (Oldfield, 1971). Hand preference was divided into two classes for convenience in data analysis: (i) right-handers (GSc from 80 to 100); and (ii) left-handers (GSc from ,80 to ,100). This study included the 13,17-year-old group patients who had GSc as described above. Thus, the present study was carried out on 2180 (1252 male and 928 female, with a mean age of 14.9 years) out of 2392 patients. The clinical examinations and radiographic assessments were performed in full-designed dental chairs. Preliminary analysis showed no differences in rates of handedness with respect to sex and age. Overall, 10.4% of the patients were left-handers. A total of 292 (13.4%) of 2180 patients examined had one or more traumatized permanent incisors. The proportion of dental trauma was significantly higher in males than in females, 17.41% in males as compared to 7.97% in females; and ratio of the affected males to females was about 2.18. Sex difference in the prevalence of traumatized permanent incisors was statistically significant (P < 0.001). That is, males had a significantly higher risk of dental trauma than females (P < 0.001; odds ratio: 2.49; 95% confidence interval (CI) 1.88, 3.23). There was a higher level of traumatized permanent incisors among left-handers than among right-handers. 28.3% of left-handers and 11.7% of right-handers had dental trauma. This difference in the prevalence of traumatized permanent incisors for handedness was statistically significant (P < 0.001). Indeed, left-handers had a significantly higher risk on dental trauma than right-handers (P < 0.001; odds ratio: 3.09; 95% CI 2.23, 4.29). The primary causative factor in the occurrence of trauma was the fall (27.7%). Then came violence and fight as the second most frequent cause of trauma (24%), followed by sports injury (18.8%). Trauma resulting from collisions and traffic accidents were accounted as 13.7 and 11.3% of all cases, respectively. The other causes were 4.5%. In conclusion, the present study suggests that left-handed adolescents have more frequent permanent incisor tooth trauma than right-handed adolescents. Left-handedness, therefore, appears to be a risk factor for trauma in 13,17-year-old adolescents. [source] Sex difference in non-alcoholic fatty liver disease and non-alcoholic steatohepatitisHEPATOLOGY RESEARCH, Issue 1 2010Tomoaki Tomiya No abstract is available for this article. [source] Sex difference in the liver of hepatocyte-specific Pten-deficient mice: A model of nonalcoholic steatohepatitisHEPATOLOGY RESEARCH, Issue 6 2009Yumiko Anezaki Aim:, Nonalcoholic fatty liver disease (NAFLD) is considered to be a public health problem worldwide. NAFLD is more prevalent in men than in women. Tamoxifen, a potent estrogen receptor antagonist, causes nonalcoholic steatohepatitis (NASH), a severe form of NAFLD. Thus, there may be a sex difference that is dependent on estrogens in NAFLD and NASH. Hepatocyte-specific Pten-deficient mice exhibit hepatic lesions analogous to NASH and are considered to be a clinical model of NASH. We aimed to shed light on any sex differences in the hepatic lesions of Pten-deficient mice and the underlying mechanisms. Methods:, At 40 weeks, livers from male and female Pten-deficient mice were processed for measuring lipid content, genes expression analysis, and histological examination. Level of serum reactive oxygen species (ROS) was also determined. Seventy-six-week-old mice were used in tumor burden experiments. Results:, Hepatic steatosis, inflammation, and even carcinogenesis in Pten-deficient mice were attenuated in females compared to males. Attenuated fatty liver in females was ascribed to inactivation of sterol regulatory element binding protein-1c. Hepatic inflammation in females was suppressed via decreased ROS with increased antioxidant gene expression and decreased proinflammatory cytokine production. Anti-cancer effect in female mice was, at least in part, due to the significantly lower ratio of oleic to stearic acid in the liver. Conclusions:, Hepatic lesions in Pten-deficient mice were attenuated in females compared to males, as were human NAFLD and NASH. Some of the underlying mechanisms in sex difference appeared to be due to the change of gene expression, dependent on estrogens. [source] Digit ratio (2D:4D), sex differences, allometry, and finger length of 12,30-year olds: Evidence from the British Broadcasting Corporation (BBC) internet studyAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 5 2010John T. Manning Many studies have reported digit ratio (2D:4D) to be sexually dimorphic, (males lower 2D:4D than females). However, Kratochvíl and Flegr ([ 2009]: Biol Lett 5:643-646) have suggested that 2D regressed on 4D has an allometric regression line with nonzero Y -intercept that is shared by males and females. Thus, 2D is shorter than expected when 4D is long, and males have lower 2D:4D than females because they have longer fingers. In this study, it is shown that this suggestion may be incorrect because sex differences in slope were not considered. Participants were recruited in an Internet study and had an age range of 12,30 years. The expected sex difference in 2D:4D was found, and the regression of 2D on 4D showed a significant sex difference in slope (males lower than females). A comparison of 10 age groups (12 years, 13 years,, 21,30 years) showed that sexual dimorphism for fingers was age dependent, varying from monomorphic to very dimorphic. Changes in sexual dimorphism of 2D:4D were much less marked, but there was a significant reduction in mean 2D:4D with age. The tendency for slopes of 2D regressed on 4D to be lower in males compared with females was significant in eight age groups. Sex difference in 2D:4D varied across the age groups and was positively related to the magnitude of the difference in female and male slopes. In contrast to the report of Kratochvíl and Flegr, it was found that the regression of 2D on 4D showed sex differences in slope, and such differences gave rise to the sexual dimorphism in 2D:4D. Am. J. Hum. Biol. 22:604,608, 2010. © 2010 Wiley-Liss, Inc. [source] Resistance exercise increases leg muscle protein synthesis and mTOR signalling independent of sexACTA PHYSIOLOGICA, Issue 1 2010H. C. Dreyer Abstract Aim:, Sex differences are evident in human skeletal muscle as the cross-sectional area of individual muscle fibres is greater in men than in women. We have recently shown that resistance exercise stimulates mammalian target of rapamycin (mTOR) signalling and muscle protein synthesis in humans during early post-exercise recovery. Therefore, the aim of this study was to determine if sex influences the muscle protein synthesis response during recovery from resistance exercise. Methods:, Seventeen subjects, nine male and eight female, were studied in the fasted state before, during and for 2 h following a bout of high-intensity leg resistance exercise. Mixed muscle protein fractional synthetic rate was measured using stable isotope techniques and mTOR signalling was assessed by immunoblotting from repeated vastus lateralis muscle biopsy samples. Results:, Post-exercise muscle protein synthesis increased by 52% in the men and by 47% in the women (P < 0.05) and was not different between groups (P > 0.05). Akt phosphorylation increased in both groups at 1 h post-exercise (P < 0.05) and returned to baseline during 2 h post-exercise with no differences between groups (P > 0.05). Phosphorylation of mTOR and its downstream effector S6K1 increased significantly and similarly between groups during post-exercise recovery (P < 0.05). eEF2 phosphorylation decreased at 1- and 2 h post-exercise (P < 0.05) to a similar extent in both groups. Conclusion:, The contraction-induced increase in early post-exercise mTOR signalling and muscle protein synthesis is independent of sex and appears to not play a role in the sexual dimorphism of leg skeletal muscle in young men and women. [source] The sexually dimorphic expression of L7/SPA, an estrogen receptor coactivator, in zebra finch telencephalonDEVELOPMENTAL NEUROBIOLOGY, Issue 14 2007Kelli A. Duncan Abstract Sex differences in the zebra finch (Taeniopygia guttata) brain are robust and include differences in morphology (song control nuclei in males are significantly larger) and behavior (only males sing courtship songs). In zebra finches, hormonal manipulations during development fail to reverse sex differences in song nuclei size and suggest that the classical model of sexual differentiation is incomplete for birds. Coactivators act to initiate transcriptional activity of steroid receptors, and may help explain why hormonal manipulations alone are not sufficient to demasculinize the male zebra finch brain. The present study investigated the expression and localization of L7/SPA (an estrogen receptor coactivator) mRNA and protein expression across the development of zebra finch song nuclei from males and females collected on P1 (song nuclei not yet formed), P10 (posthatch day 10, song nuclei formed), P30 (30 days posthatch, sexually immature but song nuclei formed and birds learning to sing), and adult birds (older than 65 days and sexually mature). Northern blot analysis showed a significant sex difference in P1 and adult L7/SPA mRNA expression while Western blot analysis also showed enhanced expression in the male brain at all age points. Both in situ hybridization and immunohistochemistry demonstrated that L7/SPA mRNA and protein were located in the song nuclei as well as expressed globally. Elevated coactivator expression may be a possible mechanism controlling the development of male song control nuclei, and coactivators such as L7/SPA may be important regulators of the masculinizing effects of estradiol on brain sexual differentiation. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007. [source] Sex differences in and hormonal regulation of Kv1 potassium channel gene expression in the electric organ: Molecular control of a social signalDEVELOPMENTAL NEUROBIOLOGY, Issue 5 2007W. Preston Few Abstract Electric fish communicate with electric organ (EO) discharges (EODs) that are sexually dimorphic, hormone-sensitive, and often individually distinct. The cells of the EO (electrocytes) of the weakly electric fish Sternopygus possess delayed rectifying K+ currents that systematically vary in their activation and deactivation kinetics, and this precise variation in K+ current kinetics helps shape sex and individual differences in the EOD. Because members of the Kv1 subfamily produce delayed rectifier currents, we cloned a number of genes in the Kv1 subfamily from the EO of Sternopygus. Using our sequences and those from genome databases, we found that in teleost fish Kv1.1 and Kv1.2 exist as duplicate pairs (Kv1.1a&b, Kv1.2a&b) whereas Kv1.3 does not. Using real-time quantitative RT-PCR, we found that Kv1.1a and Kv1.2a, but not Kv1.2b, expression in the EO is higher in high EOD frequency females (which have fast EO K+ currents) than in low EOD frequency males (which have slow EO K+ currents). Systemic treatment with dihydrotestosterone decreased Kv1.1a and Kv1.2a, but not Kv1.2b, expression in the EO, whereas treatment with human chorionic gonadotropin (hCG) increased Kv1.2a but not Kv1.1a or Kv1.2b expression in the EO. Thus, systematic variation in the ratios of Kv1 channels expressed in the EO is correlated with individual differences in and sexual dimorphism of a communication signal. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007 [source] Glutamate AMPA/kainate receptors, not GABAA receptors, mediate estradiol-induced sex differences in the hypothalamusDEVELOPMENTAL NEUROBIOLOGY, Issue 3 2007Brigitte J. Todd Abstract Sex differences in brain morphology underlie physiological and behavioral differences between males and females. During the critical perinatal period for sexual differentiation in the rat, gonadal steroids act in a regionally specific manner to alter neuronal morphology. Using Golgi-Cox impregnation, we examined several parameters of neuronal morphology in postnatal day 2 (PN2) rats. We found that in the ventromedial nucleus of the hypothalamus (VMN) and in areas just dorsal and just lateral to the VMN that there was a sex difference in total dendritic spine number (males greater) that was abolished by treating female neonates with exogenous testosterone. Dendritic branching was similarly sexually differentiated and hormonally modulated in the VMN and dorsal to the VMN. We then used spinophilin, a protein that positively correlates with the amount of dendritic spines, to investigate the mechanisms underlying these sex differences. Estradiol, which mediates most aspects of masculinization and is the aromatized product of testosterone, increased spinophilin levels in female PN2 rats to that of males. Muscimol, an agonist at GABAA receptors, did not affect spinophilin protein levels in either male or female neonates. Kainic acid, an agonist at glutamatergic AMPA/kainate receptors, mimicked the effect of estradiol in females. Antagonizing AMPA/kainate receptors with NBQX prevented the estradiol-induced increase in spinophilin in females but did not affect spinophilin level in males. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007 [source] Sex differences in the level of Bcl-2 family proteins and caspase-3 activation in the sexually dimorphic nuclei of the preoptic area in postnatal ratsDEVELOPMENTAL NEUROBIOLOGY, Issue 13 2006Shinji Tsukahara Abstract In developing rats, sex differences in the number of apoptotic cells are found in the central division of the medial preoptic nucleus (MPNc), which is a significant component of the sexually dimorphic nucleus of the preoptic area, and in the anteroventral periventricular nucleus (AVPV). Specifically, male rats have more apoptotic cells in the developing AVPV, whereas females have more apoptotic cells in the developing MPNc. To determine the mechanisms for the sex differences in apoptosis in these nuclei, we compared the expression of the Bcl-2 family members and active caspase-3 in postnatal female and male rats. Western blot analyses for the Bcl-2 family proteins were performed using preoptic tissues isolated from the brain on postnatal day (PD) 1 (day of birth) or on PD8. In the AVPV-containing tissues of PD1 rats, there were significant sex differences in the level of Bcl-2 (female > male) and Bax (female < male) proteins, but not of Bcl-xL or Bad proteins. In the MPNc-containing tissues of PD8 rats, there were significant sex differences in the protein levels for Bcl-2 (female < male), Bax (female > male), and Bad (female < male), but not for Bcl-xL. Immunohistochemical analyses showed significant sex differences in the number of active caspase-3-immunoreactive cells in the AVPV on PD1 (female < male) and in the MPNc on PD8 (female > male). We further found that active caspase-3-immunoreactive cells of the AVPV and MPNc were immunoreactive for NeuN, a neuronal marker. These results suggest that there are sex differences in the induction of apoptosis via the mitochondrial pathway during development of the AVPV and MPNc. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006 [source] Sex differences in progesterone receptor immunoreactivity in neonatal mouse brain depend on estrogen receptor , expressionDEVELOPMENTAL NEUROBIOLOGY, Issue 3 2001Christine K. Wagner Abstract Around the time of birth, male rats express higher levels of progesterone receptors in the medial preoptic nucleus (MPN) than female rats, suggesting that the MPN may be differentially sensitive to maternal hormones in developing males and females. Preliminary evidence suggests that this sex difference depends on the activation of estrogen receptors around birth. To test whether estrogen receptor alpha (ER,) is involved, we compared progesterone receptor immunoreactivity (PRir) in the brains of male and female neonatal mice that lacked a functional ER, gene or were wild type for the disrupted gene. We demonstrate that males express much higher levels of PRir in the MPN and the ventromedial nucleus of the neonatal mouse brain than females, and that PRir expression is dependent on the expression of ER, in these regions. In contrast, PRir levels in neocortex are not altered by ER, gene disruption. The results of this study suggest that the induction of PR via ER, may render specific regions of the developing male brain more sensitive to progesterone than the developing female brain, and may thereby underlie sexual differentiation of these regions. © 2001 John Wiley & Sons, Inc. J Neurobiol 47: 176,182, 2001 [source] | ||||||||||||||||||||||||||||||||||||||||