ABSTRACT
Olfactory dysfunction is associated with conditions such as neurodegenerative diseases, diabetes, obesity, autoimmune diseases, mental illnesses, and upper-airway-related diseases. The COVID-19 pandemic necessitated the development of an examiner-independent olfactory function test. We recently developed a digital olfactory function test called Digitalscent (DIGITAL SCENT), which is a kiosk-type device with an integrated hardware system. The protocol follows conventional psychophysical olfactory function protocols, including threshold, discrimination, and identification test subsets. Eight healthy participants without olfactory dysfunction volunteered for the suitability test and completed both the YSK olfactory function and Digitalscent tests. Pearson correlations were determined between the YSK olfactory function and Digitalscent tests. Digitalscent could be implemented as a conventional olfactory function test, and all participants followed the Digitalscent test protocols. Limitations in the threshold and identification test subsets included unfamiliarity of the patients to the digital test and incompleteness in the sophisticated release of odorants. A strength of the identification test subset was the dual sensory stimulation of vision and olfaction. Digitalscent could-without facilitating viral transmission-enable early diagnosis of olfactory dysfunction during respiratory viral pandemics. Future studies with larger sample sizes are warranted to facilitate wider use of this digital olfactory function test.
ABSTRACT
Lipocalin-2 (LCN2) is an inflammatory protein with diverse functions in the brain. Although many studies have investigated the mechanism of LCN2 in brain injuries, the effect of LCN2 on amyloid-toxicity-related memory deficits in a mouse model of Alzheimer's disease (AD) has been less studied. We investigated the role of LCN2 in human AD patients using a mouse model of AD. We created an AD mouse model by injecting amyloid-beta oligomer (AßO) into the hippocampus. In this model, animals exhibited impaired learning and memory. We found LCN2 upregulation in the human brain frontal lobe, as well as a positive correlation between white matter ischemic changes and serum LCN2. We also found increased astrocytic LCN2, microglia activation, iron accumulation, and blood-brain barrier disruption in AßO-treated hippocampi. These findings suggest that LCN2 is involved in a variety of amyloid toxicity mechanisms, especially neuroinflammation and oxidative stress.
ABSTRACT
A highly specific lead-binding peptide ThrAsnThrLeuSerAsnAsn was displayed on Escherichia coli, and lead adsorption characteristics of the recombinant bacteria were investigated. Cell surface-displayed peptide was expressed under the control of an arabinose promoter using outer membrane protein C (OmpC(t)) as an anchoring motif. The optimal induction period and arabinose concentration for the expression of peptide-fused OmpC(t) were determined to be 2 h and 0.001 g/L, respectively. Selective adsorption of Pb(2+) onto recombinant cells was verified with individual or combinatory use of four metal ions, Pb(2+), Ni(2+), Co(2+), and Cu(2+); the amount of bound Pb(2+) onto the biosorbents was significantly higher than the other metal ions. The adsorption isotherm of recombinant cells for Pb(2+) followed the Langmuir isotherm with a maximum adsorption loading (q (max)) of 526 µmol/g dry cell weight.
