Delirium and sleep disturbances-A narrative review.

BACKGROUND: Delirium is considered a severe complication. It increases morbidity and mortality and represents a major financial burden for healthcare systems. Thus, prevention becomes a focal point of research. Sleep disturbances have been linked to the occurrence of delirium. Consequently, several interventions that target a possible connection have been studied in recent years. OBJECTIVE: This narrative literature review explores the published data for an association between delirium and different types of sleep disturbances, the pathophysiological interactions and prevention methods. MATERIAL AND METHODS: A literature search was carried out utilizing PubMed, the Cochrane Library, Livivo and Google Scholar. RESULTS: Although an association between several types of sleep disturbances and delirium has been shown, no causality has been proven so far. Nevertheless, several pharmacological and nonpharmacological interventions for delirium prevention have been attempted; however, the level of evidence is insufficient at this point. CONCLUSION: Further research is required to prove causality between sleep disturbances and delirium. Nonpharmacological interventions should be used in construction and maintenance of intensive care units and hospitals. Pharmacological interventions could be effective for prevention but further research is needed. Screening patients at risk of delirium for sleep disturbances and antihistaminergic/anticholinergic medication seems beneficial.

Axial Stretching of Vessels in the Retinal Vascular Plexus With 3D OCT-Angiography.

PURPOSE: The purpose of this study is to describe and quantify the nonpathological axial stretching in the retinal vascular plexus in three-dimensional (3D) optical coherence tomography angiography (OCTA) images. METHODS: The 3D vascular network underneath the inner limiting membrane of OCTA volumes was labeled as ground truth (GT) data. To analyze the cross-section area of the vessels the width and depth of the vessels in the GT data were computed and an elliptical quotient was proposed to quantify the axial stretching. RESULTS: A total of 21 3D OCTA volumes were labeled. It was found that the vessels in 3D OCTA images are stretched in the direction of the A-Scan by a factor of 2.46 ± 1.82 with a median of 2.24. Furthermore, a larger cross-section area leads to higher axial stretching. CONCLUSIONS: The elliptical shape of the cross-section area of the vessel does not match with the expected pathology of the vascular network in the human eye. Therefore a correction of the volume data before a 3D analysis is recommended. TRANSLATIONAL RELEVANCE: This work gives a systematic insight to the stretched shape of vessels in 3D OCTA images and is relevant for further clinical research analyzing the 3D vascular network.

Calcium-mediated actin reset (CaAR) mediates acute cell adaptations.

Actin has well established functions in cellular morphogenesis. However, it is not well understood how the various actin assemblies in a cell are kept in a dynamic equilibrium, in particular when cells have to respond to acute signals. Here, we characterize a rapid and transient actin reset in response to increased intracellular calcium levels. Within seconds of calcium influx, the formin INF2 stimulates filament polymerization at the endoplasmic reticulum (ER), while cortical actin is disassembled. The reaction is then reversed within a few minutes. This Calcium-mediated actin reset (CaAR) occurs in a wide range of mammalian cell types and in response to many physiological cues. CaAR leads to transient immobilization of organelles, drives reorganization of actin during cell cortex repair, cell spreading and wound healing, and induces long-lasting changes in gene expression. Our findings suggest that CaAR acts as fundamental facilitator of cellular adaptations in response to acute signals and stress.