The development of medial temporal lobe circuits is critical for subsequent learning and memory functions later in life. The present study reports the expression of progesterone receptor (PR), a powerful transcription factor of the nuclear steroid receptor superfamily, in Cajal-Retzius cells of the molecular layer of the dentate gyrus of rats. PR was transiently expressed from the day of birth through postnatal day 21, but was absent thereafter. Although PR immunoreactive (PR-ir) cells did not clearly express typical markers of mature neurons, they possessed an ultrastructural morphology consistent with neurons. PRir cells did not express markers for GABAergic neurons, neuronal precursor cells, nor radial glia. However, virtually all PR cells co-expressed the calcium binding protein, calretinin, and the glycoprotein, reelin, both reliable markers for Cajal-Retzius neurons, a transient population of developmentally critical pioneer neurons that guide synaptogenesis of perforant path afferents and histogenesis of the dentate gyrus. Indeed, inhibition of PR activity during the first two weeks of life impaired adult performance on both the novel object recognition and object placement memory tasks, two behavioral tasks hypothesized to describe facets of episodic-like memory in rodents. These findings suggest that PR plays an unexplored and important role in the development of hippocampal circuitry and adult memory function.

Context The true prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has been difficult to determine due to limited testing, inconsistent symptom severity, and asymptomatic infections. Systematic investigation of the prevalence of SARS-CoV-2 has been limited to urban environments and large academic centers. Limited data on the seroprevalence of SARS-CoV-2 is available for those who live in a rural community setting, leaving rural practitioners to extrapolate the epidemiology of COVID-19 to a nonhomogeneous population. Objective To determine the seroprevalence of SARS-CoV-2 in a community setting. The secondary objective of this study was to describe the difference in infection rate and reverse transcription polymerase chain reaction (RT-PCR) testing in the same rural community. Methods A prospective convenience sample of community members and healthcare workers from the Kingman, Arizona area were tested for SARS-CoV-2–specific antibodies using a lateral flow immunoassay with the VITROS Anti-SARS-CoV-2 IgG test (Ortho-Clinical Diagnostics, Inc.) from September 28, 2020 to October 09, 2020. Upon recruitment, participants were asked to complete a demographic survey assessing socioeconomic status, comorbidities, and COVID-19 symptoms in the preceding two months. Following enrollment, a retrospective chart review was completed to determine the percentage of patients who had undergone previous SARS-CoV-RT-PCR testing. Results A total of 566 participants were included in the final analysis: 380 (67.1%) were women, 186 (32.9%) were men, a majority (458; 80.9%) self-identified as White, and 303 (53.5%) were employed as healthcare professionals. Seroprevalence of SARS-CoV-2 was found to be 8.0% (45 of 566) across the sample and 9.9% (30 of 303) in healthcare workers. No statistical difference in seroprevalence was found between men and women, healthcare workers and other participants, amongst racial groups, by socioeconomic status, by comorbid conditions, or by education level. Among the participants, 108 (19.1%) underwent previous RT-PCR testing. Of the 45 patients who were antibody positive, 27 (60%) had received a previous RT-PCR test, with 20 (44.4%) testing positive for SARS-CoV-2. Participants with symptoms of anosmia/ageusia (p<0.001), chest congestion (p=0.047), fever (p=0.007), and shortness of breath (p=0.002) within the past two months were more likely to have antibodies to SARS-CoV-2. Conclusion Only 8% of 566 participants in this rural community setting were found to have antibodies for SARS-CoV-2. A large minority (18; 40%) of patients testing seropositive for SARs-CoV-2 had never received a prior test, suggesting that the actual rates of infection are higher than publicly available data suggest. Further large-scale antibody testing is needed to determine the true prevalence of SARS-CoV-2 in the rural setting.

IntroductionAcute respiratory distress syndrome (ARDS) and coronavirus disease 2019 (COVID-19)-associated acute respiratory distress syndrome (CARDS) are both characterized by non-cardiogenic pulmonary edema and severe hypoxemia that leads to a high percentage of patients suffering in-hospital mortality. Mechanistically, inhaled epoprostenol (iEPO) has shown a role in the treatment of ARDS and CARDS but little data are available directly comparing the two disease processes. Due to the lack of evidence of iEPO in ARDS and CARDS, the authors sought to compare the pulmonary effects of iEPO for mechanically ventilated patients with CARDS against a case match control of those with ARDS. MethodsA retrospective cohort of all patients receiving iEPO between January 1, 2020, and February 22, 2022, was reviewed. Patients with ARDS were case-matched in a 2:1 allocation ratio of CARDS to ARDS by the number of medical comorbidities and age +/-5 years. Clinical data collected included patient demographics, laboratory values, ventilator settings, length of hospitalization, and 28-day mortality. Comparisons of the effectiveness of iEPO between ARDS and CARDS were conducted using the chi-squared statistic for categorical variables and the Mann-Whitney statistic for continuous variables. ResultsA total of 72 patients were included in the final analysis, with 24 having ARDS and 48 CARDS. The number of medical comorbidities was no different for patients with ARDS or CARDs (p = 0.18), though the frequency of patients diagnosed with coronary artery disease (p=0.007), congestive heart failure (p=0.003), chronic obstructive pulmonary disease (p=0.004), and pulmonary hypertension (p=0.004) did vary between the two groups. A moderate but non-significant difference in pre-iEPO partial pressure of oxygen (PaO 2 )/fraction of inspired oxygen (FiO 2 ) ratio was noted between the groups (0.74 vs 0.65; p=0.33). Following iEPO treatment, patients with ARDS showed a greater PaO 2 /FiO 2 ratio than those with CARDS (0.87 vs 0.70; p=0.02). CARDS patients who received iEPO had a longer length of stay as compared to those with ARDS (17.5 vs 12.5 days; p=0.01). However, no difference was noted in 28-day mortality between the two groups (14 vs 34; p=0.29). ConclusionIn this small sample from a single community hospital, a statistically significant improvement in the PaO 2 /FiO 2 ratio was noted for both those with ARDS and CARDS. However, those with CARDS who were given iEPO had a longer length of stay without a significant difference in mortality as compared to those with traditional ARDS.

The cover image is based on the Research Article Progesterone receptor expression in cajal‐retzius cells of the developing rat dentate gyrus: Potential role in hippocampus‐dependent memory by Andrew J. Newell et al., DOI: https://doi.org/10.1002/cne.24485.