Startup Bexorg, led by Zvonimir Vrselja, keeps human brains alive to test drugs. Their BrainEx system sustains brain cells for 24 hours to improve drug development and reduce animal testing.

This review article summarizes the current literature investigating the effects of transient sex hormone fluctuations on large artery endothelial function, primarily concerning the menstrual cycle and the diurnal rhythm of testosterone secretion. Women and men experience acute fluctuations in circulating levels of sex hormones, and there is substantial variability in circulating levels of sex hormones in both sexes. These acute fluctuations in sex hormones generally coincide with alterations in endothelial cell function and in vivo endothelium-dependent vasodilation, and we see that the timing of these acute fluctuations match the timing of cardiovascular events in both women and men. It is important to improve our understanding of how acute fluctuations in sex hormones affect endothelial function in women and men, as clinical cardiovascular complications coincide with these changes. This would allow for the identification of novel therapeutic targets and aid in the prevention and treatment of cardiovascular disease.

Cardiovascular disease (CVD) is the leading cause of death in both men and women, but there are sex differences in the timing and mechanisms of diseas…