A concerted mechanism involving ACAT and SREBPs by which oxysterols deplete accessible cholesterol to restrict microbial infection.

Most of the cholesterol in the plasma membranes (PMs) of animal cells is sequestered through interactions with phospholipids and transmembrane domains of proteins. However, as cholesterol concentration rises above the PM's sequestration capacity, a new pool of cholesterol, called accessible cholesterol, emerges. The transport of accessible cholesterol between the PM and the endoplasmic reticulum (ER) is critical to maintain cholesterol homeostasis. This pathway has also been implicated in the suppression of both bacterial and viral pathogens by immunomodulatory oxysterols. Here, we describe a mechanism of depletion of accessible cholesterol from PMs by the oxysterol 25-hydroxycholesterol (25HC). We show that 25HC-mediated activation of acyl coenzyme A: cholesterol acyltransferase (ACAT) in the ER creates an imbalance in the equilibrium distribution of accessible cholesterol between the ER and PM. This imbalance triggers the rapid internalization of accessible cholesterol from the PM, and this depletion is sustained for long periods of time through 25HC-mediated suppression of SREBPs and continued activation of ACAT. In support of a physiological role for this mechanism, 25HC failed to suppress Zika virus and human coronavirus infection in ACAT-deficient cells, and Listeria monocytogenes infection in ACAT-deficient cells and mice. We propose that selective depletion of accessible PM cholesterol triggered by ACAT activation and sustained through SREBP suppression underpins the immunological activities of 25HC and a functionally related class of oxysterols.

Cross-Sector Monitoring and Evaluation Framework: Social, Economic, and Health Conditions Impacted During the COVID-19 Pandemic.

Public Health 3.0 approaches are critical for monitoring disparities in economic, social, and overall health impacts following the COVID-19 pandemic and its associated policy changes to slow community spread. Timely, cross-sector data as identified using this approach help decisionmakers identify changes, track racial disparities, and address unintended consequences during a pandemic. We applied a monitoring and evaluation framework that combined policy changes with timely, relevant cross-sector data and community review. Indicators covered unemployment, basic needs, family violence, education, childcare, access to health care, and mental, physical, and behavioral health. In response to increasing COVID-19 cases, nonpharmaceutical intervention strategies were implemented in March 2020 in King County, Washington. By December 2020, 554 000 unemployment claims were filed. Social service calls increased 100%, behavioral health crisis calls increased 25%, and domestic violence calls increased 25%, with disproportionate impact on communities of color. This framework can be replicated by local jurisdictions to inform and address racial inequities in ongoing COVID-19 mitigation and recovery. Cross-sector collaboration between public health and sectors addressing the social determinants of health are an essential first step to have an impact on long-standing racial inequities. (Am J Public Health. 2021;111(S3):S215-S223. https://doi.org/10.2105/AJPH.2021.306422).

Factors Influencing US Allopathic Medical Students to Choose Pathology as a Specialty.

The SARS-CoV-2 pandemic has highlighted the crucial role of pathologists in the health care system at a time of significant decline in the number of US medical students matching to pathology residency positions. To understand this decline, a national survey of fourth-year US allopathic medical students was conducted to assess experiences, knowledge, and attitudes of pathology and factors that impact specialty choice. Participating in a separate pathology course did not increase the probability of choosing pathology. Experiences significantly associated with choosing pathology included clinical or research opportunities in pathology during the last 2 years of medical school, autopsy observation/participation, and participation in pathology interest groups. Many respondents felt they were not sufficiently exposed to pathology to consider it as a specialty. Those who considered pathology but did not choose it were less likely to report understanding the activities of pathologists and being recruited by pathology faculty and more likely to express a preference for more direct patient contact as compared to those entering pathology. In general, respondents agreed that pathology has a good work-life balance and a satisfying degree of intellectual challenge. On the other hand, respondents generally agreed that information on social media and perception of the pathology job market do not seem to be positive and few agreed that pathology is a highly regarded specialty. We identify steps to address these issues and increase the number of US medical students choosing pathology as a specialty crucial to the future of medicine and public health.

Managing COVID-19 in Renal Transplant Recipients: A Review of Recent Literature and Case Supporting Corticosteroid-sparing Immunosuppression.

Novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome virus (SARS-CoV-2) has become a global health care crisis. The Centers for Disease Control and Prevention (CDC) lists immunocompromised patients, including those requiring immunosuppression following renal transplantation, as high risk for severe disease from SARS-CoV-2. Treatment for other viral infections in renal transplant recipients often includes a reduction in immunosuppression; however, no current guidelines are available recommending the optimal approach to managing immunosuppression in the patients who are infected with SARS-CoV-2. It is currently advised to avoid corticosteroids in the treatment of SARS-CoV-2 outside of critically ill patients. Recently published cases describing inpatient care of COVID-19 in renal transplant recipients differ widely in disease severity, time from transplantation, baseline immunosuppressive therapy, and the modifications made to immunosuppression during COVID-19 treatment. This review summarizes and compares inpatient immunosuppressant management strategies of recently published reports in the renal transplant population infected with SARS-CoV-2 and discusses the limitations of corticosteroids in managing immunosuppression in this patient population.