The relationship of physical trauma and surgical stress to menstrual dysfunction

Bite Wounds and Dominance Structures in Male and Female African Spiny Mice (Acomys cahirinus): Implications for Animal Welfare and the Generalizability of Experimental Results

Bite wounds due to aggression in male laboratory mice (Mus musculus) are a major welfare concern, often leading to attrition, chronic activation of the innate immune system, and significant impacts on the experimental results derived from the use of these animals as models. Bite wounding within the home-cage of spiny mice (Acomys cahirinus)-a valuable research model for wound healing and menstruation-is poorly characterized. While we have anecdotally observed frequent bite wounding in Acomys, the frequency of aggression within the home-cage, the severity of the bite wounds, and the types of dominance structures remain unstudied. Here, we report that 46% of Acomys cages in our colony had at least one bite wound over the course of a year and that same-sex pairs fought in the home-cage 10% of the time during their dark/active phase. Both sexes inflicted wounds and frequently engaged in agonistic behaviors, even with stable dominance structures. We found that females inflicted less severe bite wounds in same-sex housing. Also, aged females in same-sex pairs were never observed fighting, and no bite wounds were observed in aged Acomys. These results suggest that we should consider whether bite wounding negatively impacts our experimental results since physical trauma is known to alter menstrual cycling and healing.

Some sex hormone profiles are consistent over time in normal menstruating women: implications for sports injury epidemiology

PURPOSE

It is unclear whether sex hormone profiles obtained in two consecutive months are consistent within women. Month-to-month consistency in daily, nadir, peak and mean hormone concentrations during the early follicular and luteal phases in recreationally active, young eumenorrheic women was prospectively examined.

METHODS

60 healthy, non-smoking women who reported normal and consistent menstrual cycles lasting 26-32 days for the past 6 months were followed prospectively to obtain serum samples for the first 6 days of menses and for 8 days after a positive ovulation test over two consecutive months. Month-to-month consistency of daily concentrations of oestradiol (pg/ml), progesterone (ng/ml), testosterone (ng/dl), sex hormone-binding globulin (nmol/l) and free androgen index were determined using linear mixed models. Month-to-month consistency in nadir, peak and mean concentrations were then assessed using intraclass correlation coefficients and SEM to more precisely examine intraindividual consistency.

RESULTS

Linear mixed models revealed stable hormone concentrations across cycles and cycles by day. Reliability estimates for nadir, peak, mean menses and mean postovulatory concentrations range from 0.56 to 0.86 for oestradiol, 0.44 to 0.91 for progesterone, 0.60 to 0.86 for testosterone, 0.88 to 0.97 for sex hormone-binding globulin and 0.78 to 0.91 for free androgen index.

CONCLUSIONS

Hormone profiles were reproducible over two consecutive months. To reduce month-to-month intraindividual variations and improve measurement consistency, it is recommended that multiple samples be taken over consecutive days as opposed to a single sample.

Amenorrhoea in newly spinal cord injured women: an effect of hyperprolactinaemia?

STUDY DESIGN

Prospective, single centre study.

OBJECTIVES

Previous studies have suggested a relationship between stress reaction and elevated levels of prolactine. The aim of the present study was to investigate if there was a relationship between s-prolactine and menstrual cycle status following spinal cord injury (SCI).

SETTING

Spinal Cord Injury Unit, Göteborg, Sweden.

METHODS

S-prolactine and menstrual cycle status were investigated in 16 consecutive women with SCI, treated at the SCI Unit, Sahlgrens University Hospital, Göteborg, Sweden. Level of injury ranged from C1 to L5, ASIA A-D. Mean age at injury was 45 years (range 20-79).

RESULTS

S-Prolactine showed a mean value of 741 mIU/l (standard deviation (s.d.): 625; 95% confidence interval (CI): 435-1788 mIU/l, reference value <400 mIU/l). When dividing the group according to fertility status we found hyperprolactinaemia in the women who were in childbearing age (n=9): mean value 1050 mIU/l (s.d.: 678; 95% CI: 607-1493 mIU/ml), whereas it was normal in the group in menopause (n=7): mean value 343 mIU/l (s.d.: 185, 95% CI: 206-480 mIU/l) (P<0.01 when comparing groups). The group that developed amenorrhoea showed the highest values of s-prolactine. All values but one was normalised 3-6 months later.

CONCLUSION

Amenorrhoea following SCI is correlated to level of s-prolactine. We found no correlation between level of s-prolactine and level or degree of injury.