Biomedical subjects

Masayuki Yamamoto

Publications and source records attributed to Masayuki Yamamoto.

2 recordsLinked to original sources

PubMed2026

Seafood and polyunsaturated fatty acid intake and age-related hearing loss: a cross-sectional study conducted in Japan.

BACKGROUND: Age-related hearing loss (ARHL) is a common condition associated with dementia, social isolation, and reduced quality of life. N-3 polyunsaturated fatty acids (N-3 PUFAs), mainly derived from seafood, have been hypothesized to protect against ARHL through anti-inflammatory and antioxidant effects. However, evidence remains inconsistent. This cross-sectional study examined the association of seafood and dietary fatty acid intakes with ARHL in a Japanese population with high seafood consumption. METHODS: A total of 13,908 adults aged 50-79 years from the Tohoku Medical Megabank Project Cohort Study were included. Hearing thresholds were measured by pure-tone audiometry at 500, 1,000, 2,000, and 4,000 Hz. Dietary intake was assessed using a validated food frequency questionnaire. Seafood, N-3 PUFA, and saturated fatty acid (SFA) intakes were categorized into quartiles. Multivariable linear regression was used to estimate adjusted mean differences in hearing thresholds. RESULTS: In men, higher SFA intake was significantly associated with lower hearing thresholds at 1,000 Hz (Q4 vs. Q1: β = -2.23 dB HL, 95% CI: -3.437 to -1.023) and for pure-tone average (β = -1.704 dB HL; 95% CI, -2.872 to -0.536). Seafood and N-3 PUFA intakes were not significantly associated with hearing thresholds. In women, no significant associations were observed. CONCLUSION: In this population with high seafood consumption, seafood and N-3 PUFA intakes were not associated with hearing thresholds. Low SFA intake may be associated with higher hearing thresholds in Japanese men, suggesting that the relationship between dietary fatty acids and ARHL may be complex and may differ by sex.

Age-related hearing loss↗

PubMed2025

JG2: an updated version of the Japanese population-specific reference genome.

Here we present the construction of JG2, an updated population-specific reference genome for the Japanese population. Utilizing data from three individuals previously used in the construction of JG1, several methodologies were employed to enhance genomic coverage and assembly quality. Hi-C sequencing technology facilitated phase-aware assembly, generating two haploid assemblies per individual and enabling improved representation of genetic variation. A meta-assembly strategy and a majority decision approach further refined assembly quality by combining the best sequences from multiple assemblies and minimizing the inclusion of rare variants. The resulting JG2 genome comprises chromosome-level sequences, mitochondrial chromosomes and unplaced scaffolds, offering more comprehensive coverage of the Japanese genome. Comparative analyses with other reference genomes demonstrated the accuracy and representativeness of JG2, highlighting its utility for genetic research involving the Japanese population. Overall, by adopting the phased assembly technique, JG2 represents a substantial advancement over the collapsed assembly-based JG1, with improvements including a greater number of identified variants (3,115,695 variants, of which 298,644 had an allele frequency (AF) of 1.0 in the 3.5KJPNv2 AF panel) and a higher N50 value (152,668,378 bp). These enhancements provide researchers with a more precise and comprehensive resource for understanding the genetic landscape of the Japanese population. The sequences and annotations are available on the jMorp website ( https://jmorp.megabank.tohoku.ac.jp/ ).

Journal Article↗