Obligatory role of hypothalamic neuroestradiol during the estrogen-induced LH surge in female ovariectomized rhesus monkeys.

Negative and positive feedback effects of ovarian 17ß-estradiol (E2) regulating release of gonadotropin releasing hormone (GnRH) and luteinizing hormone (LH) are pivotal events in female reproductive function. While ovarian feedback on hypothalamo-pituitary function is a well-established concept, the present study shows that neuroestradiol, locally synthesized in the hypothalamus, is a part of estrogen's positive feedback loop. In experiment 1, E2 benzoate-induced LH surges in ovariectomized female monkeys were severely attenuated by systemic administration of the aromatase inhibitor, letrozole. Aromatase is the enzyme responsible for synthesis of E2 from androgens. In experiment 2, using microdialysis, GnRH and kisspeptin surges induced by E2 benzoate were similarly attenuated by infusion of letrozole into the median eminence of the hypothalamus. Therefore, neuroestradiol is an integral part of the hypothalamic engagement in response to elevated circulating E2 Collectively, we will need to modify the concept of estrogen's positive feedback mechanism.

Medical Student Patient Outreach to Ensure Continuity of Care During the COVID-19 Pandemic.

Background: In response to the COVID-19 pandemic, the Yale New Haven Health System began rescheduling nonurgent outpatient appointments as virtual visits in March 2020. While Yale New Haven Health expanded its telemedicine infrastructure to accommodate this shift, many appointments were delayed and patients faced considerable uncertainty. Objective: Medical students created the Medical Student Task Force (MSTF) to help ensure continuity of care by calling patients whose appointments were delayed during this transition to telemedicine. Methods: Eighty-five student volunteers called 3765 internal medicine patients with canceled appointments, completing screening for 2197 patients. Volunteers screened for health care needs, assessed preferences for future appointments, and offered emotional support and information about COVID-19. Urgent or emergent patient concerns were triaged and escalated to providers. In this analysis, we used a mixed-methods approach: call information and provider responses were analyzed quantitatively, and patient feedback was analyzed qualitatively via thematic analysis. Results: Ninety-one percent of patients screened found the MSTF calls helpful. Twenty-one percent of patients reported health concerns, with 1% reporting urgent concerns escalated to and addressed by providers. Themes of patient comments included gratitude for outreach and social contact, utility of calls, and well-wishes for health care workers. Conclusions: By calling patients whose appointments had been canceled during a rapid transition to telemedicine, the MSTF helped bridge a potential gap in care by offering patients communication with their care teams, information, and support. We propose that this model could be used in other care systems urgently transitioning to outpatient telemedicine, whether during ongoing outbreaks of COVID-19 or other public health emergencies.