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.

Design of efficacious somatic cell genome editing strategies for recessive and polygenic diseases.

Compound heterozygous recessive or polygenic diseases could be addressed through gene correction of multiple alleles. However, targeting of multiple alleles using genome editors could lead to mixed genotypes and adverse events that amplify during tissue morphogenesis. Here we demonstrate that Cas9-ribonucleoprotein-based genome editors can correct two distinct mutant alleles within a single human cell precisely. Gene-corrected cells in an induced pluripotent stem cell model of Pompe disease expressed the corrected transcript from both corrected alleles, leading to enzymatic cross-correction of diseased cells. Using a quantitative in silico model for the in vivo delivery of genome editors into the developing human infant liver, we identify progenitor targeting, delivery efficiencies, and suppression of imprecise editing outcomes at the on-target site as key design parameters that control the efficacy of various therapeutic strategies. This work establishes that precise gene editing to correct multiple distinct gene variants could be highly efficacious if designed appropriately.

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.

Assembly of CRISPR ribonucleoproteins with biotinylated oligonucleotides via an RNA aptamer for precise gene editing.

Writing specific DNA sequences into the human genome is challenging with non-viral gene-editing reagents, since most of the edited sequences contain various imprecise insertions or deletions. We developed a modular RNA aptamer-streptavidin strategy, termed S1mplex, to complex CRISPR-Cas9 ribonucleoproteins with a nucleic acid donor template, as well as other biotinylated molecules such as quantum dots. In human cells, tailored S1mplexes increase the ratio of precisely edited to imprecisely edited alleles up to 18-fold higher than standard gene-editing methods, and enrich cell populations containing multiplexed precise edits up to 42-fold. These advances with versatile, preassembled reagents could greatly reduce the time and cost of in vitro or ex vivo gene-editing applications in precision medicine and drug discovery and aid in the development of increased and serial dosing regimens for somatic gene editing in vivo.

High-Content Analysis of CRISPR-Cas9 Gene-Edited Human Embryonic Stem Cells.

CRISPR-Cas9 gene editing of human cells and tissues holds much promise to advance medicine and biology, but standard editing methods require weeks to months of reagent preparation and selection where much or all of the initial edited samples are destroyed during analysis. ArrayEdit, a simple approach utilizing surface-modified multiwell plates containing one-pot transcribed single-guide RNAs, separates thousands of edited cell populations for automated, live, high-content imaging and analysis. The approach lowers the time and cost of gene editing and produces edited human embryonic stem cells at high efficiencies. Edited genes can be expressed in both pluripotent stem cells and differentiated cells. This preclinical platform adds important capabilities to observe editing and selection in situ within complex structures generated by human cells, ultimately enabling optical and other molecular perturbations in the editing workflow that could refine the specificity and versatility of gene editing.