Male rodents typically display an advantage over female conspecifics in tasks that assess memory for the identity or location of objects. However, the performance of female rodents on object recognition and object location tasks often is enhanced by elevated levels of ovarian steroids. The novel object-in-place task, combines elements of object recognition and object location tasks used to assess rodent object memory. Until now, only male rats have been tested on the object-in-place task, therefore, a study was conducted to compare the performance of males to females under different hormone conditions. Rats were given a sample phase to study the locations of four objects in an open field. After various delays, a test phase was administered with the locations of two objects reversed. Increased investigation of moved objects indicates memory for these objects and their original locations. Rats were able to discriminate moved from unmoved objects after a brief 5-min delay, regardless of biological sex or hormone status. However, gonadally intact males, but not diestrous females, were able to discriminate object locations after a 30-min delay. In contrast, ovariectomized females treated with estradiol and progesterone discriminated moved from unmoved objects after a 60-min delay while ovariectomized vehicle-treated females and gonadally intact males did not. Results indicate that female rats outperform males on a memory task that combines object recognition and location but only when circulating levels of the ovarian steroids, estradiol and progesterone, are elevated and only when memory is challenged by an extended retention interval.
BACKGROUND Alcohol-related motor vehicle collisions (AR-MVCs) account for ~30% of all US traffic fatalities. Ride-sharing services (RSS) have existed since 2010, but few studies to date have investigated their impact on AR-MVCs. We hypothesized that the availability of RSS would be correlated with a decrease in AR-MVCs at an urban Level I trauma center. METHODS A retrospective chart review was conducted of all AR-MVC trauma activations at a Level I trauma center from 2012 to 2018. Additional data were gathered from regional governmental traffic and law enforcement databases, including crash incidence, fatalities, and demographics. Data were compared pre- and post-RSS and analyzed using an unpaired t test with p less than 0.05 considered significant. RESULTS There were 1,474 patients in AR-MVCs during the study period. There was a significant decrease in the annual average proportion of MVCs that were AR-MVCs pre- vs. post-RSS (39% vs. 29%, p = 0.02) as well as a decrease in the average annual incidence of fatal AR-MVCs (11.6 vs. 5, p = 0.02). Subset analysis showed a decrease in AR-MVC incidence in 18- to 29-year-olds (12.7% vs. 7.5%; p = 0.03), which was also demonstrated by data from a local law enforcement database. Availability of RSS was also correlated with a decreased proportion of nighttime AR-MVCs (14.7% vs. 7.6%, p = 0.03) and decreased number of driving while intoxicated (1198.0 ± 78.5 vs. 612.8 ± 137.6, p = <0.01). CONCLUSION We found that the incidence of both total AR-MVCs and fatal AR-MVCs presenting to our trauma center decreased after the introduction of RSS. Ride-sharing services may play a role in preventing AR-MVCs. Further research is needed to correlate AR-MVC incidence with granular proprietary RSS usage data and to account for any confounding factors. Future studies may identify ways to better utilize RSS availability as a targeted intervention for certain demographic groups to prevent AR-MVCs. LEVEL OF EVIDENCE Therapeutic/Care Management, Level IV.
Aims: To assess if marijuana consumption – prevalent among men of reproductive age and becoming widespread due to decriminalization – is associated with changes in semen parameters. Marijuana’s active metabolite, tetrahydrocannabinol, can alter signaling pathways within spermatozoa, affecting spermatogenesis and fertility. Methods: We prospectively evaluated semen analyses (SA) from men presenting for infertility evaluation at one institution from July 2017 to April 2018. Participants completed a reproductive health questionnaire including items regarding marijuana consumption. SA was performed in accordance with World Health Organization (WHO) 5th Edition criteria. SA parameters included volume (ml), concentration (million/ml), motility (%), progressive motility (%), and Tygerberg strict morphology (%). Results: A total of 409 patients completed the questionnaire; 174 (43%) men reported marijuana use (ever-users). Current and past users comprised 71 (17%) and 103 (25%), respectively. Compared with never-users, current and past users had a significantly higher likelihood of abnormal sperm strict morphology (33.1% versus 50.7% and 53.4%, respectively; p < 0.001). However, sperm motility was more likely to be less than WHO reference values in never-users than current and past-users (38.3% versus 21.1% and 27.2%, respectively; p = 0.01). In multivariate logistic regression analyses, current use was associated with increased odds of abnormal strict morphology [odds ratio (OR) 2.15, 95% confidence interval (CI): 1.21–3.79] and semen volume less than WHO reference value (OR 2.76, 95%CI: 1.19–6.42), while odds of less than WHO reference value sperm motility were reduced (OR 0.47, 95%CI: 0.25–0.91). Conclusion: Marijuana use is common among men presenting for fertility evaluation, and may have a detrimental effect on semen quality, particularly morphology and volume, but may be protective against abnormal sperm motility. Large, prospective studies of both semen quality and fertility in this growing, at-risk population are warranted.
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