Adherence to Physical Distancing and Health Beliefs About COVID-19 Among Patients With Cancer.

BACKGROUND: This study aimed to validate questionnaires on adherence to physical distancing and health beliefs about coronavirus disease 2019 (COVID-19) among patients with cancer and explore their interaction with depression or viral anxiety among them. METHODS: Through an online survey, data from 154 cancer patients (female: 82.5%, breast cancer: 66.2%, current cancer treatment, presence: 65.6%) were collected from March to June 2022. The survey gathered responses to questionnaires on adherence to physical distancing, health beliefs about COVID-19, perceived social norms, Stress and Anxiety to Viral Epidemics-6 items, and Patient Health Questionnaire-2. Confirmatory factor analysis (CFA) for construct validity and structural equation model (SEM) were performed. RESULTS: The CFA showed a good model fit for adherence to physical distancing (comparative fit index [CFI] = 1.000, Tucker-Lewis index [TLI] = 0.930, root-mean-square-error of approximation [RMSEA] = 0.000, and standardized root-mean-square residual [SRMR] = 0.050) and a satisfactory model fit for health beliefs about COVID-19 (CFI = 0.978, TLI = 0.971, RMSEA = 0.061, and SRMR = 0.089). Through SEM, we found that personal injunctive norms were the main mediators linking health beliefs with physical distancing in patients with cancer. Depression also mediated the effects of viral anxiety and perceived severity on physical distancing (χ² = 20.073, df = 15, P = 0.169; CFI = 0.984; RMSEA = 0.047). CONCLUSION: The questionnaires are reliable and valid. Patients with cancer may be able to adhere to physical distancing by addressing perceived severity, viral anxiety, perceived benefits, self-efficacy, perceived barriers, as well as personal injunctive norms.

Orexin Impairs the Phagocytosis and Degradation of Amyloid-ß Fibrils by Microglial Cells.

BACKGROUND: Intracranial accumulation of amyloid-ß (Aß) is a characteristic finding of Alzheimer's disease (AD). It is thought to be the result of Aß overproduction by neurons and impaired clearance by several systems, including degradation by microglia. Sleep disturbance is now considered a risk factor for AD, but studies focusing on how sleep modulates microglial handling of Aß have been scarce. OBJECTIVE: To determine whether phagocytosis and degradation of extracellular Aß fibrils by BV2 microglial cells were impaired by treatment with orexin-A/B, a major modulator of the sleep-wake cycle, which may mimic sleep deprivation conditions. METHODS: BV2 cells were treated with orexin and Aß for various durations and phagocytic and autophagic processes for degradation of extracellular Aß were examined. RESULTS: After treatment with orexin, the formation of actin filaments around Aß fibrils, which is needed for phagocytosis, was impaired, and phagocytosis regulating molecules such as PI3K, Akt, and p38-MAPK were downregulated in BV2 cells. Orexin also suppressed autophagic flux, through disruption of the autophagosome-lysosome fusion process, resulting in impaired Aß degradation in BV2 cells. CONCLUSIONS: Our results demonstrate that orexin can hinder clearance of Aß through the suppression of phagocytosis and autophagic flux in microglia. This is a novel mechanism linking AD and sleep, and suggests that attenuated microglial function, due to sleep deprivation, may increase Aß accumulation in the brain.