Publications by authors named "Kristi Henjum"

Alterations in brain energy metabolism have long been proposed as one of several neurobiological processes contributing to delirium. This is supported by previous findings of altered CSF lactate and neuron-specific enolase concentrations and decreased glucose uptake on brain-PET in patients with delirium. Despite this, there are limited data on metabolic alterations found in CSF samples, and targeted metabolic profiling of CSF metabolites involved in energy metabolism has not been performed.

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BACKGROUNDThe kynurenine pathway (KP) has been identified as a potential mediator linking acute illness to cognitive dysfunction by generating neuroactive metabolites in response to inflammation. Delirium (acute confusion) is a common complication of acute illness and is associated with increased risk of dementia and mortality. However, the molecular mechanisms underlying delirium, particularly in relation to the KP, remain elusive.

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Noradrenergic and dopaminergic neurons are involved in cognitive functions, relate to behavioral and psychological symptoms in dementia and are affected in Alzheimer's disease (AD). Amyloid plaques (A), neurofibrillary tangles (T) and neurodegeneration (N) hallmarks the AD neuropathology. Today, the AT(N) pathophysiology can be assessed through biomarkers.

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Dopamine and noradrenaline are functionally connected to delirium and have been targets for pharmacological interventions but the biochemical evidence to support this notion is limited. To study the CSF levels of dopamine, noradrenaline and the third catecholamine adrenaline in delirium and dementia, these were quantified in three patient cohorts: (i) cognitively normal elderly patients ( = 122); (ii) hip fracture patients with or without delirium and dementia ( = 118); and (iii) patients with delirium precipitated by another medical condition (medical delirium,  = 26). Delirium was assessed by the Confusion Assessment Method.

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Introduction: The progression rate of Alzheimer's disease (AD) varies and might be affected by the triggering receptor expressed on myeloid cells (TREM2) activity. We explored if cerebrospinal fluid (CSF) soluble TREM2 (sTREM2), a proxy of microglial activity, is associated with clinical progression rate.

Methods: Patients with clinical AD (N = 231) were followed for up to 3 years after diagnosis.

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Triggering receptor expressed on myeloid cells 2 (TREM2) is an innate immune receptor expressed by microglia. Its cleaved fragments, soluble TREM2 (sTREM2), can be measured in the cerebrospinal fluid (CSF). Previous studies indicate higher CSF sTREM2 in symptomatic AD; however most of these studies have included biomarker positive AD cases and biomarker negative controls.

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Background: Delirium is associated with dementia and thus biomarkers reflecting neurodegeneration are of interest. Fatty acid-binding protein 3 (FABP3) is a cytoplasmic neuronal protein that has been isolated from the brain. It is released following brain injury and concentrations in cerebrospinal fluid (CSF) are also higher in neurodegenerative disorders such as Alzheimer's disease (AD).

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The mechanisms of amyloid-β (Aβ)-degradation and clearance in Alzheimer's disease (AD) pathogenesis have been relatively little studied. Short Aβ-fragments form by enzymatic cleavage and alternate amyloid-beta precursor protein (APP)-processing. Here we characterized a novel polyclonal Aβ-antibody raised against an Aβ mid-domain and used it to investigate microglial Aβ-uptake in situ by microscopy at the light- and ultrastructural levels.

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Neuroinflammation may be a key factor in brain atrophy in aging and age-related neurodegenerative disease. The objective of this study was to test the association between microglial expression of soluble Triggering Receptor Expressed on Myeloid Cells 2 (sTREM2), as a measure of neuroinflammation, and brain atrophy in cognitively unimpaired older adults. Brain magnetic resonance imagings (MRIs) and cerebrospinal fluid (CSF) sTREM2, total tau (t-tau), phosphorylated181 tau (p-tau), and Aβ42 were analyzed in 115 cognitively unimpaired older adults, classified according to the A/T/(N)-framework.

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Background: Neuronal and glial cell interaction is essential for synaptic homeostasis and may be affected in Alzheimer's disease (AD). We measured cerebrospinal fluid (CSF) neuronal and glia markers along the AD continuum, to reveal putative protective or harmful stage-dependent patterns of activation.

Methods: We included healthy controls (n = 36) and Aβ-positive (Aβ+) cases (as defined by pathological CSF amyloid beta 1-42 (Aβ42)) with either subjective cognitive decline (SCD, n = 19), mild cognitive impairment (MCI, n = 39), or AD dementia (n = 27).

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Background: Delirium and dementia share symptoms of cognitive dysfunctions, and mechanisms of neuroinflammation appear involved in both conditions. Triggering receptor expressed on myeloid cells 2 (TREM2) is linked to dementia and neurodegenerative disease. It encodes expression of an innate immune receptor in the brain expressed by microglia.

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Foods naturally high in dietary fiber are generally considered to protect against development of colorectal cancer (CRC). However, the intrinsic effect of dietary fiber on intestinal carcinogenesis is unclear. We used azoxymethane (AOM) treated A/J Min/+ mice, which developed a significantly higher tumor load in the colon than in the small intestine, to compare the effects of dietary inulin (IN), cellulose (CE) or brewers spent grain (BSG) on intestinal tumorigenesis and cecal microbiota.

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Background: Alzheimer's disease (AD) neuropathology is associated with neuroinflammation, but there are few useful biomarkers. Mutant variants of triggering receptor expressed on myeloid cells 2 (TREM2) have recently been linked to late-onset AD and other neurodegenerative disorders. TREM2, a microglial receptor, is involved in innate immunity.

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Surface coatings of nanoparticles (NPs) are known to influence advantageous features of NPs as well as potential toxicity. Iron oxide (Fe3O4) NPs are applied for both medical diagnostics and targeted drug delivery. We investigated the potential cytotoxicity and genotoxicity of uncoated iron oxide (U-Fe3O4) NPs in comparison with oleate-coated iron oxide (OC-Fe3O4) NPs.

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N-Methyl-D-aspartate receptors (NMDARs) are essential mediators of synaptic plasticity under normal physiological conditions. During brain ischemia, these receptors are excessively activated due to glutamate overflow and mediate excitotoxic cell death. Although organotypical hippocampal slice cultures are widely used to study brain ischemia in vitro by induction of oxygen and glucose deprivation (OGD), there is scant data regarding expression and functionality of NMDARs in such slice cultures.

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