Sex differences in the onset of seasonal reproductive quiescence in hamsters

Day length is the primary cue used by many mammals to restrict reproduction to favourable spring and summer months, but it is unknown for any mammal whether the seasonal loss of fertility begins at the same time and occurs at the same rate in females and males; nor it established whether the termination of mating behaviour in males and females coincides with the loss of fertility. We speculated that females, owing to their greater energetic investment in reproduction, are the limiting sex in terminating offspring production in short days (SDs). Oestrous cycles and production of young were monitored in Syrian hamsters ( Mesocricetus auratus ) transferred from long days (LDs) to SDs. Females were mated to LD males after three to eight weeks of SD treatment; in a parallel experiment, males housed in SDs were mated to LD females. After five and eight weeks in SDs, at least twice as many males as females were fertile. Both males and females continued to copulate for several weeks after becoming infertile. The onset of seasonal infertility occurs earlier in females than males and the decline in fertility precedes the seasonal loss of mating behaviour in both sexes.

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Short Days and Exogenous Melatonin Increase Aggression of Male Syrian Hamsters (Mesocricetus auratus)

Hormones and Behavior ◽

10.1006/hbeh.2002.1797 ◽

2002 ◽

Vol 42 (1) ◽

pp. 13-20 ◽

Cited By ~ 66

Author(s):

Aaron M. Jasnow ◽

Kim L. Huhman ◽

Timothy J. Bartness ◽

Gregory E. Demas

Keyword(s):

Mesocricetus Auratus ◽

Syrian Hamsters ◽

Exogenous Melatonin ◽

Short Days

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Exposure to short days, but not short-term melatonin, enhances humoral immunity of male Syrian hamsters (Mesocricetus auratus )

Journal of Pineal Research ◽

10.1034/j.1600-079x.2002.02915.x ◽

2002 ◽

Vol 33 (2) ◽

pp. 118-124 ◽

Cited By ~ 17

Author(s):

Deborah L. Drazen ◽

Aaron M. Jasnow ◽

Randy J. Nelson ◽

Gregory E. Demas

Keyword(s):

Humoral Immunity ◽

Mesocricetus Auratus ◽

Short Term ◽

Syrian Hamsters ◽

Short Days

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Cause and Possible Treatments of Foot Lesions in Captive Syrian Hamsters (Mesocricetus auratus)

Veterinary Medicine International ◽

10.4061/2010/951708 ◽

2010 ◽

Vol 2010 ◽

pp. 1-5 ◽

Cited By ~ 1

Author(s):

Mélisa Veillette ◽

Julie Guitard ◽

Stéphan G. Reebs

Keyword(s):

Wound Healing ◽

Vitamin E ◽

Animal Welfare ◽

Treatment Period ◽

Mesocricetus Auratus ◽

Syrian Hamsters ◽

Pretreatment Period ◽

Foot Lesions ◽

Males And Females ◽

Pre Treatment

Syrian hamsters (Mesocricetus auratus) run extensively in exercise wheels. This running may cause paw lesions. Three treatments of these wounds (topical application of vitamin E, wheel blocking, and a combination of both) were compared using both sexes. A pretreatment period with or without wheels lasted 15 days and the ensuing treatment period lasted 45 days. At the end of the pre-treatment period, none of the animals without wheels had paw wounds, whereas at least 75% of the females and 100% of the males with wheels did. Females had fewer and smaller wounds than males at this point. At the end of the treatment period, no effect of vitamin E could be discerned, but significant wound healing occurred after wheel blocking in both males and females. Wheel blocking is an easy way to prevent or treat paw wounds, but it presents problems in terms of animal welfare, as wheels are an important cage enrichment for hamsters.

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Sex Difference in Self-Reported Sexual Functioning Among Frail Older Adults

Innovation in Aging ◽

10.1093/geroni/igaa057.1002 ◽

2020 ◽

Vol 4 (Supplement_1) ◽

pp. 313-313

Author(s):

Brianne Olivieri-Mui ◽

Sandra Shi ◽

Ellen McCarthy ◽

Dae Kim

Keyword(s):

Older Adults ◽

Logistic Regression ◽

Sex Differences ◽

Sexual Function ◽

Older Adult ◽

Sexual Functioning ◽

Social Life ◽

Well Being ◽

Adult Males ◽

Males And Females

Abstract Frailty may differentially impact how older adult males and females perceive sexual functioning, an important part of well-being. We assessed the level of frailty (robust, pre-frail, frail) for anyone with data on 11 sexual functioning questions asked in wave 2 of the National Social Life, Health, and Aging Project, 2010-2011 (n=2060). Questions covered five domains: overall sexual function (OSF), sexual function anxiety (SFA), changes in sexual function (CSF), erectile/vaginal dysfunction (EVD), and masturbation. Logistic regression identified sex differences in frailty and reporting worse sexual functioning. Linear regression predicted the number of domains reported as worse. Among males (n=1057), pre-frailty meant higher odds of reporting SFA (OR 1.8 95%CI 1.2-6.6), CSF (OR 1.7 95%CI 1.1-2.7), and EVD (OR 1.5 95%CI 1.0-2.2). Among females (n=1003), there was no difference in reporting by frailty. Females were more likely to report worse OSF (Robust: OR 7.4, 95%CI 4.8-11.4; Pre-frail: OR 6.2, 95%CI 3.9-9.9; Frail: OR 3.4 95%CI 1.7-6.6), but less likely to report SFA (Robust OR .3, 95%CI .2-.5; Pre-frail OR .2, 95%CI .1-.3; Frail OR .2 95%CI .1-.3). Pre-frail and frail females reported fewer domains as worse (Pre-frail coefficient -0.21 SE 0.09, Frail -0.43 SE 0.14). As frailty worsened, males reported more domains as worse (Pre-frail 0.24 SE 0.07, Frail 0.29 SE 0.08). Self-reported sexual functioning differs by sex at all levels of frailty, and reporting by males, but not females, changes with frailty. Providers should be aware that sexual functioning is of importance to both sexes despite varying degrees of frailty.

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Stem cell treatment improves post stroke neurological outcomes: a comparative study in male and female rats

Stroke and Vascular Neurology ◽

10.1136/svn-2020-000834 ◽

2021 ◽

pp. svn-2020-000834

Author(s):

Koteswara Rao Nalamolu ◽

Bharath Chelluboina ◽

Casimir A Fornal ◽

Siva Reddy Challa ◽

David M Pinson ◽

...

Keyword(s):

Stem Cells ◽

Sex Differences ◽

Motor Function ◽

Infarct Volume ◽

Female Rats ◽

Human Umbilical Cord ◽

Male And Female ◽

Post Stroke ◽

Male And Female Rats ◽

Males And Females

Background and purposeThe therapeutic potential of different stem cells for ischaemic stroke treatment is intriguing and somewhat controversial. Recent results from our laboratory have demonstrated the potential benefits of human umbilical cord blood-derived mesenchymal stem cells (MSC) in a rodent stroke model. We hypothesised that MSC treatment would effectively promote the recovery of sensory and motor function in both males and females, despite any apparent sex differences in post stroke brain injury.MethodsTransient focal cerebral ischaemia was induced in adult Sprague-Dawley rats by occlusion of the middle cerebral artery. Following the procedure, male and female rats of the untreated group were euthanised 1 day after reperfusion and their brains were used to estimate the resulting infarct volume and tissue swelling. Additional groups of stroke-induced male and female rats were treated with MSC or vehicle and were subsequently subjected to a battery of standard neurological/neurobehavioral tests (Modified Neurological Severity Score assessment, adhesive tape removal, beam walk and rotarod). The tests were administered at regular intervals (at days 1, 3, 5, 7 and 14) after reperfusion to determine the time course of neurological and functional recovery after stroke.ResultsThe infarct volume and extent of swelling of the ischaemic brain were similar in males and females. Despite similar pathological stroke lesions, the clinical manifestations of stroke were more pronounced in males than females, as indicated by the neurological scores and other tests. MSC treatment significantly improved the recovery of sensory and motor function in both sexes, and it demonstrated efficacy in both moderate stroke (females) and severe stroke (males).ConclusionsDespite sex differences in the severity of post stroke outcomes, MSC treatment promoted the recovery of sensory and motor function in male and female rats, suggesting that it may be a promising treatment for stroke.

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OP0013 SEX DIFFERENCES IN AUTOIMMUNE DISEASE SUSCEPTIBILITY; A MULTI-OMIC APPROACH

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2021-eular.1405 ◽

2021 ◽

Vol 80 (Suppl 1) ◽

pp. 8.1-8

Author(s):

G. Robinson ◽

K. Waddington ◽

J. Peng ◽

A. Radziszewska ◽

H. Peckham ◽

...

Keyword(s):

Sex Differences ◽

Lipid Metabolism ◽

Sex Hormones ◽

Cell Function ◽

Immune Cell ◽

Density Lipoprotein ◽

Hormone Treatment ◽

Immune Cell Function ◽

Immune Cell Subsets ◽

Males And Females

Background:Males and females have altered immune responses resulting in variation in autoimmune and cardiovascular disease risk (CVR). Recently, these differences have played a role in the inflammatory response to COVID-19. Sex differences exist in the frequency and activity of immune-cell subsets but mechanisms underlying sexual dimorphism remain unknown. Juvenile-onset systemic lupus erythematosus (JSLE) is an autoimmune disorder that commonly emerges during puberty, has a strong female prevalence (female:male ratio, 4.5:1) and results in an increased CVR. JSLE is characterised by chronic inflammation and dyslipidaemia, where cardiovascular disease is a leading cause of mortality for patients. Our previous work identified a link between immune cell function and lipid metabolism in adult-onset SLE. We hypothesised that sex hormones could influence both lipid metabolism and immune cell function and this could determine sex-specific susceptibility to JSLE and associated CVR.Objectives:We investigated the role of sex hormones in modifying systemic lipid metabolism and inflammation.Methods:Nuclear magnetic resonance spectroscopy based serum metabolomics measuring over 130 lipoproteins (14-subsets with lipid compositions), flow cytometry measuring immune-cells, and RNA-sequencing were used to assess the metabolic and immune profile in young, pre/post-pubertal males (n=10/17) and females (n=10/23) and in individuals with gender-dysphoria (GD) under cross-hormone treatment (trans-male/female, n=26/25). This analysis was also performed on a cohort of post-pubertal male (n=12) and female (n=23) JSLE patients. Data was analysed by logistic regression, balanced random forest machine learning (BRF-ML), differential gene expression (DEG) and pathway analysis.Results:Post-pubertal males had significantly reduced cardio-protective high-density lipoprotein (HDL) subsets (p<0.0001) and increased cardio-pathogenic very-low-density lipoprotein subsets (p<0.0001) compared to females. These differences were not observed pre-puberty and were reversed significantly by cross-hormone treatment in GD individuals, suggesting that sex hormones regulate lipid metabolism in-vivo.BRF-ML (28 immune-cell subsets) identified an increased frequency of anti-inflammatory regulatory T-cells (Tregs) in post-pubertal males compared to females (p=0.0097). These Tregs were also more suppressive in males compared to females. Differences in Treg frequency were seen pre-puberty and were not altered by sex hormone treatment in GD individuals. However, Treg DEGs and functional transcriptomic pathways altered between post-pubertal males and females, including those involved in inflammatory signalling, overlapped with those altered by hormones in GD, suggesting hormones may also drive Treg functional changes. In addition, HDL metabolites modified by hormones showed differential associations with Treg phenotypes between post-pubertal males and females.Strikingly, sex differences in lipoproteins and Tregs were lost in JSLE, suggesting hormone signalling could be dysregulated in the pathogenesis of autoimmunity and could increase CVR for patients.Conclusion:Sex hormones drive altered lipoprotein metabolism and functional transcriptomic pathways in Tregs. Males have a lipoprotein profile associated with increased CVR, but a more anti-inflammatory immune profile compared to females. Together, this could explain sex differences in inflammatory disease susceptibilities and inform future sex-specific therapeutic strategies for the management of both JSLE and CVR.Acknowledgements:Lupus UKRosetrees TrustVersus ArthritisNIHR UCLH Biomedical Research CentreDisclosure of Interests:None declared

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Sex differences in outcomes after arthroscopic bankart repair

BMJ Open Sport & Exercise Medicine ◽

10.1136/bmjsem-2020-000965 ◽

2020 ◽

Vol 6 (1) ◽

pp. e000965

Author(s):

Natalie A Lowenstein ◽

Peter J Ostergaard ◽

Daniel B Haber ◽

Kirsten D Garvey ◽

Elizabeth G Matzkin

Keyword(s):

Mental Health ◽

Sex Differences ◽

Patient Reported Outcomes ◽

Strength Function ◽

Bankart Repair ◽

Level Of Evidence ◽

Arthroscopic Bankart Repair ◽

Patient Reported ◽

Males And Females

ObjectivesRisk factors for anterior shoulder dislocation include young age, contact activities and male sex. The influence of sex on patient-reported outcomes of arthroscopic Bankart repair (ABR) is unclear, with few studies reporting potential differences. This study’s purpose was to compare patient-reported outcomes of males and females following ABR.MethodsProspectively collected data was analysed for 281 patients (males: 206, females: 75) after ABR with preoperative, 1-year and 2-year follow-up responses. The Wilcoxon signed-rank and χ2 tests, preoperative, 1 year and 2 year follow-up results were examined to determine differences of scores in males versus females.ResultsNo statistically significant sex differences were observed in Simple Shoulder Test (SST), American Shoulder and Elbow Surgeons (ASES), Visual Analogue Scale (VAS) or Single Assessment Numerical Evaluation (SANE) Scores at 1-year or 2-year follow-up. Females had lower Veterans RAND 12-item health survey (VR-12) mental health subscores at 2-year follow-up (females: 52.3±9.0, males: 55.8±7.6, p=0.0016). Females were more likely to report that treatment had ‘exceeded expectations’ at 2-year follow-up regarding motion, strength, function and normal sports activities.ConclusionResults of study demonstrate that ABR has similar outcomes for both males and females. There were no statistically significant sex-related differences in SST, ASES, VAS or SANE scores following ABR. VR-12 mental health subscores showed a minimal difference at 2-year follow-up, with lower scores in females.Level of evidenceRetrospective cohort study; level II.

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No sex differences in learning in wild bumblebees

Behavioral Ecology ◽

10.1093/beheco/arab013 ◽

2021 ◽

Cited By ~ 1

Author(s):

Felicity Muth ◽

Amber D Tripodi ◽

Rene Bonilla ◽

James P Strange ◽

Anne S Leonard

Keyword(s):

Sex Differences ◽

Associative Learning ◽

Sierra Nevada ◽

Comparative Cognition ◽

Natural Populations ◽

Interspecific Variation ◽

Learning Task ◽

Learning Ability ◽

Learning Performance ◽

Males And Females

Abstract Females and males often face different sources of selection, resulting in dimorphism in morphological, physiological, and even cognitive traits. Sex differences are often studied in respect to spatial cognition, yet the different ecological roles of males and females might shape cognition in multiple ways. For example, in dietary generalist bumblebees (Bombus), the ability to learn associations is critical to female workers, who face informationally rich foraging scenarios as they collect nectar and pollen from thousands of flowers over a period of weeks to months to feed the colony. While male bumblebees likely need to learn associations as well, they only forage for themselves while searching for potential mates. It is thus less clear whether foraging males would benefit from the same associative learning performance as foraging females. In this system, as in others, cognitive performance is typically studied in lab-reared animals under captive conditions, which may not be representative of patterns in the wild. In the first test of sex and species differences in cognition using wild bumblebees, we compared the performance of Bombus vancouverensis nearcticus (formerly bifarius) and Bombus vosnesenskii of both sexes on an associative learning task at Sierra Nevada (CA) field sites. Across both species, we found that males and females did not differ in their ability to learn, although males were slower to respond to the sucrose reward. These results offer the first evidence from natural populations that male bumblebees may be equally as able to learn associations as females, supporting findings from captive colonies of commercial bees. The observed interspecific variation in learning ability opens the door to using the Bombus system to test hypotheses about comparative cognition.

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P110 Sex differences in hand osteoarthritis symptoms and function

Rheumatology ◽

10.1093/rheumatology/keab247.106 ◽

2021 ◽

Vol 60 (Supplement_1) ◽

Author(s):

Brona Dinneen ◽

David Heath ◽

Mohammed Tauseef Ghaffar ◽

Miriam O'Sullivan ◽

Carmel Silke ◽

...

Keyword(s):

Sex Differences ◽

Pain Intensity ◽

Motor Skills ◽

Functional Assessment ◽

Functional Ability ◽

Fine Motor ◽

Hand Osteoarthritis ◽

Fine Motor Skills ◽

Males And Females ◽

And Function

Abstract Background/Aims There is currently no consensus regarding sex-related differences in pain intensity and functional abilities among patients with hand osteoarthritis (OA). In this study we determine sex-related differences in pain intensity and functional ability among patients with hand OA, as assessed by a self-report questionnaire and by performance-based tests. Methods Using the AUSCAN tool for symptom and functional assessment of hand OA with dynamometry we prospectively accessed patients meeting the ACR criteria for hand osteoarthritis. Using this analysis, assessments of pain and function were compared in male and female patients. The outcome measures included self-reported pain measures, functional assessment and dynamometry measures. Results The study population included 106 patients (90 females and 16 males) with a mean age of males 48.44 (7.48) and females 52.67 (9.43). All patients with symptomatic hand osteoarthritis meeting ACR Criteria. When accessing difference between sexes, men were found to be significantly heavier (p = 0.003) and have greater grip and pinch strength.As part of function and pain assessments there was a significant correlation between difficulty with fine motor skills such as difficulty doing buttons, difficulty when doing jewellery, or peeling vegetables associated with pain when turning objects e.g. doorknobs, taps and faucets for men in comparison to women. Difficulty in these fine motor skills also correlated with stiffness on wakening and pain on lifting heavy objects regardless of sex. A Mann-Whitney U test was run on 106 participants to determine if there were differences in pain or functional scores between males and females. This reviled Median score for males () and females () was statistically significantly different,There were sex differences noted in the correlation associated with pain with rotational movements e.g. turning objects and functional difficulty with fine motor movements including difficulty when doing up buttons ( Males r(14) = -0.109, p = 0.698, Females r(88) =0.489, p = <0.01 value.= ), difficulty when doing jewellery ( Males r(14) =-0.265, p = 0.339.= Females r(88) = 0.570, p = <0.01) , difficulty peeling vegetables ( Males r(14) = -0.207, p = 0.458 Females r(88) = 0.519, <0.01 ) Conclusion The results demonstrate the presence of sex differences in patients suffering from hand osteoarthritis self-reported functional ability and pain scales. These differences indicate the need for further studies to explore the mechanisms of hand OA and to understanding the specific impact of gender on the development and progression of disease. With further understanding we can obtain the proper strategy to provide better individualised treatment. It also highlights that rehabilitation programs should consider these differences and each patients’ performance limitations in order to address the specific needs of each individual patient. In doing so, improved pain and functional status will improve morbidity in hand OA Disclosure B. Dinneen: None. D. Heath: None. M. Ghaffar: None. M. O'Sullivan: None. C. Silke: None. B. Whelan: None.

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