Regulation of the blood-brain barrier in health and disease: Astrocytes at the barricade

Vries, H.E. de [Promotor]Dijkstra, C.D. [Promotor]Reijerkerk, A. [Copromotor

Blood-Brain Barrier Disruption in Multiple Sclerosis

The blood-brain barrier is specialized to function as a barrier to protect the central nervous system by restricting entry of unwanted molecules and immune cells into the brain and inversely, to prevent central nervous system-born agents from reaching the systemic circulation. The blood-brain barrier endothelium, together with cells involved in its regulation forms the neurovascular unit. Blood-brain barrier dysfunction is an important hallmark of early multiple sclerosis pathophysiology, leading to a consequent loss of the imperative brain homeostasis and subsequent neuronal dysfunction and damage. The neuroinfl ammatory changes at the blood-brain barrier are numerous and include the loss of barrier function, altered communication with surrounding cells, and activation of both infl ammation promoting and dampening mechanisms. A better understanding of blood-brain barrier alterations in neuroinfl ammation might lead to new ways to promote blood-brain barrier function in neurological diseases like multiple sclerosis

Delay or postponement of medical care among older adults in the Netherlands at earlier and later stages of the COVID-19 pandemic

AIMS: The aim of the current study was to compare cancellations or postponement of medical care among older adults during the COVID-19 pandemic between 2021 and 2020. METHODS: Data of respondents aged ≥ 62 years were used from the longitudinal aging study Amsterdam (LASA), collected in 2020 and 2021, directly after the main COVID-19 waves in the Netherlands. A questionnaire assessed cancellations of medical care and postponed help-seeking behavior. Descriptive analyses were performed. RESULTS: Overall, cancellations declined from 35% in 2020 (sample n = 1128) to 17% in 2021 (sample n = 1020). Healthcare-initiated cancellations declined from 29 to 8%. Respondent-initiated cancellations declined from 12 to 7%. Postponed help-seeking remained around 8%. CONCLUSIONS: In 2021, less cancellations were reported compared to just after the first wave of the pandemic in 2020, while postponed help-seeking remained the same. It is important to investigate how cancellations and postponed help-seeking can be prevented in future pandemics

Purification of cells from fresh human brain tissue: primary human glial cells.

In order to translate the findings obtained from postmortem brain tissue samples to functional biologic mechanisms of central nervous system disease, it will be necessary to understand how these findings affect the different cell populations in the brain. The acute isolation and analysis of pure glial cell populations are common practice in animal models for neurologic diseases, but are not yet regularly applied to human postmortem brain material. The development of novel cell isolation techniques and methods for transcriptomic and proteomic analysis have made it possible to isolate and phenotype primary human cell populations from the central nervous system. The psychiatric program of the Netherlands Brain Bank has considerable experience with the purification of glial cells. This chapter will review the rapid isolation and phenotyping procedures for two major glia cell populations in the human brain, microglia and astrocytes, and will also discuss the potential for biobanking these cells, as well as the possible alternatives to cell isolations. The acute isolation of glial cells without culture-based adherence steps allows the analysis of glial alterations that underlie, or are the result of, disease neuropathology of the donor