Radiographic findings of SARS-CoV-2 infection.

STUDY OBJECTIVE: The 2019-20 coronavirus pandemic is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19). This study was undertaken to identify and compare findings of chest radiography and computed tomography among patients with SARS-CoV-2 infection. METHODS: This retrospective study was undertaken at a tertiary care center. Eligible subjects included consecutive patients age 18 and over with documented SARS-CoV-2 infection between March and July 2020. The primary outcome measures were results of chest radiography and computed tomography among patients with documented SARS-CoV-2 infection. RESULTS: Among 724 subjects, most were admitted to a medical floor (46.4%; N = 324) or admitted to an ICU (10.9%; N = 76). A substantial number of subjects were intubated during the emergency department visit or inpatient hospitalization (15.3%; N = 109). The majority of patients received a chest radiograph (80%; N = 579). The most common findings were normal, bilateral infiltrates, ground-glass opacities, or unilateral infiltrate. Among 128 patients who had both chest radiography and computed tomography, there was considerable disagreement between the 2 studies (52.3%; N = 67; 95% confidence interval: 43.7% to 61.0%).). The presence of bilateral infiltrates (infiltrates or ground-glass opacities) was associated with clinical factors including older age, ambulance arrivals, more urgent triage levels, higher heart rate, and lower oxygen saturation. Bilateral infiltrates were associated with poorer outcomes, including higher rate of intubation, greater number of inpatient days, and higher rate of death. CONCLUSIONS: Common radiographic findings of SARS-CoV-2 infection include infiltrates or ground-glass opacities. There was considerable disagreement between chest radiography and computed tomography. Computed tomography was more accurate in defining the extent of involved lung parenchyma. The presence of bilateral infiltrates was associated with morbidity and mortality.

Neuronal Activity in Non-LNv Clock Cells Is Required to Produce Free-Running Rest:Activity Rhythms in Drosophila.

Circadian rhythms in behavior and physiology are produced by central brain clock neurons that can be divided into subpopulations based on molecular and functional characteristics. It has become clear that coherent behavioral rhythms result from the coordinated action of these clock neuron populations, but many questions remain regarding the organizational logic of the clock network. Here we used targeted genetic tools in Drosophila to eliminate either molecular clock function or neuronal activity in discrete clock neuron subsets. We find that neuronal firing is necessary across multiple clock cell populations to produce free-running rhythms of rest and activity. In contrast, such rhythms are much more subtly affected by molecular clock suppression in the same cells. These findings demonstrate that network connectivity can compensate for a lack of molecular oscillations within subsets of clock cells. We further show that small ventrolateral (sLNv) clock neurons, which have been characterized as master pacemakers under free-running conditions, cannot drive rhythms independent of communication between other cells of the clock network. In particular, we pinpoint an essential contribution of the dorsolateral (LNd) clock neurons, and show that manipulations that affect LNd function reduce circadian rhythm strength without affecting molecular cycling in sLNv cells. These results suggest a hierarchical organization in which circadian information is first consolidated among one or more clock cell populations before accessing output pathways that control locomotor activity.

A guide to choosing fluorescent protein combinations for flow cytometric analysis based on spectral overlap.

The advent of facile genome engineering technologies has made the generation of knock-in gene-expression or fusion-protein reporters more tractable. Fluorescent protein labeling of specific genes combined with surface marker profiling can more specifically identify a cell population. However, the question of which fluorescent proteins to utilize to generate reporter constructs is made difficult by the number of candidate proteins and the lack of updated experimental data on newer fluorescent proteins. Compounding this problem, most fluorescent proteins are designed and tested for use in microscopy. To address this, we cloned and characterized the detection sensitivity, spectral overlap, and spillover spreading of 13 monomeric fluorescent proteins to determine utility in multicolor panels. We identified a group of five fluorescent proteins with high signal to noise ratio, minimal spectral overlap, and low spillover spreading making them compatible for multicolor experiments. Specifically, generating reporters with combinations of three of these proteins would allow efficient measurements even at low-level expression. Because the proteins are monomeric, they could function either as gene-expression or as fusion-protein reporters. Additionally, this approach can be generalized as new fluorescent proteins are developed to determine their usefulness in multicolor panels. © 2018 International Society for Advancement of Cytometry.