Ultrastructural analysis of the morphological phenotypes of microglia associated with neuroinflammatory cues.

Microglia are the primary resident immune cells of the central nervous system that are responsible for the maintenance of brain homeostasis. There is a plethora of evidence to suggest that microglia display distinct phenotypes that are associated with the alteration of cell morphology under varying environmental cues. However, it has not been fully explored how the varying states of microglial activation are linked to the alteration of microglia morphology, especially in the microdomain. The objective of this study was to quantitatively characterize the ultrastructural morphology of human microglia under neuroinflammatory cues. To address this, a human cell line of microglia was stimulated by antiinflammatory (IL-4), proinflammatory (TNF-α), and Alzheimer's disease (AD)-associated cues (Aß, Aß + TNF-α). The resulting effects on microglia morphology associated with changes in microdomain were analyzed using a high-resolution scanning electron microscopy. Our findings demonstrated that microglial activation under proinflammatory and AD-cues were closely linked to changes not only in cell shape but also in cell surface topography and higher-order branching of processes. Furthermore, our results revealed that microglia under proinflammatory cues exhibited unique morphological features involving cell-to-cell contact and the formation of vesicle-like structures. Our study provides insight into the fine details of microglia morphology associated with varying status of microglial activation.

COVID-19: The Lived Experience of Critical Care Nurses.

OBJECTIVE: The goal of this qualitative phenomenological study was to explore in-depth, critical care nurses' (CCNs) lived experience while caring for coronavirus disease 2019 (COVID-19) patients during the pandemic. BACKGROUND: CCNs play an important role during pandemics characterized by highly contagious, life-threatening disease. Understanding the experience of CCNs during a pandemic is particularly important because of the high rate of burnout within this group, as well as a shortage of these caregivers across the globe. METHODS: Using Heidegger's interpretive phenomenological approach, interviews were conducted with 10 CCNs caring for COVID-19 patients. The goal of the interviews was to access a deep layer of understanding regarding participants' lived experience. RESULTS: Themes of role frustration, emotional and physical exhaustion, and the importance of presence were revealed. CONCLUSION: Themes revealed suggest a number of actions hospital administrators could take to support CCNs as they experience the challenges of a pandemic.