Development of a High-Sensitivity Method for the Measurement of Human Nasal Aβ42, Tau, and Phosphorylated Tau.

Cost-effective and feasible methods for early diagnosis of Alzheimer's disease (AD) are needed. We present two methods to measure AD-related biomarkers simultaneously from one nasal smear for the purpose of diagnosing AD. Japanese men and women aged 63-85 years old were recruited in 2015-2016 for this case-control study.

β-Amyloid peptide (1-40) in the brain reaches the nasal cavity via a non-blood pathway.

We examined the distribution patterns of human β-amyloid (1-40) peptide labeled with iodine 125 ((125)I-Aβ40) after injections into the cerebral ventricle or tail vein of rats. In rats receiving an intravenous injection, the radioactive concentration of (125)I-Aβ40 in the nasal area was similar to other extracranial organs. In contrast, the caudal part of the nasal area in rats receiving an intracerebroventricular injection displayed a high level of (125)I-Aβ40 radioactivity.

Correlation of Aβ deposition in the nasal cavity with the formation of senile plaques in the brain of a transgenic mouse model of Alzheimer's disease.

The deposition of β-amyloid peptides (Aβ) is commonly reported in the nasal cavity of Alzheimer's disease (AD) patients, although the pathological significance of this finding is unknown. This study compared Aβ concentrations in the nasal area with those in the brain, blood, and cerebrospinal fluid, respectively. Immunohistochemical analysis identified Aβ deposits in the nasal epithelium of Tg2576 mice.

Position-specific incorporation of a highly photodurable and blue-laser excitable fluorescent amino acid into proteins for fluorescence sensing.

A new fluorescent amino acid, L-2-acridonylalanine, was incorporated into proteins at specific positions using 4-base codon/anticodon strategy. The efficiency of the incorporation was high enough to obtain enough quantities of the mutants. The acridonyl group was highly fluorescent when it was excited at the wavelengths of blue-lasers and was highly photodurable compared with conventional fluorophores often used for biological analyses.