Efficacy of Dietary Intervention with Group Activities on Dietary Intakes, Frailty Status, and Working Memory: A Cluster-Randomized Controlled Trial in Community Strongholds.

Geriatric community centers often offer nutrition lectures to older adults. In order to make learning more interesting and pragmatic, we developed group activity sessions. This undertaking was tested for its efficacy in changes of frailty status and several other geriatric health parameters. A cluster-randomized controlled trial was conducted between September 2018 and December 2019 at 13 luncheon-providing community strongholds in Taipei, Taiwan. During the 3-month intervention period, 6 experimental strongholds received a weekly 1 h exercise workout and 1 h nutrition activities aiming at achieving the recommendations of the Taiwanese Daily Food Guide for elderlies; the other 7 received a weekly 1 h exercise workout and 1 h other activities. Dietary intakes and frailty status were the primary outcomes. Secondary outcomes included working memory and depression. The measurements were performed at baseline, 3 months, and 6 months. The nutrition intervention significantly reduced the intake of refined grains and roots (p = 0.003) and increased that of non-refined grains and roots (p = 0.008), dairy products (p < 0.0001), and seeds and nuts (at borderline, p = 0.080) at 3 months. Some, but not all, of these changes were maintained at 6 months. Performance improvements included the frailty status score (p = 0.036) and forward digit span (p = 0.004), a working memory parameter, at 3 months. Only the forward digit span remained improved (p = 0.007) at 6 months. The 3-month nutrition group activities combined with exercise sessions improved the frailty status and working memory more than exercise alone. The dietary and frailty improvements were accompanied by improved dietary intakes and advanced behavioral stages. However, the improved frailty status backslid after intervention ceased, suggesting that boosting activities are needed for maintaining the intervention effect.

Tyrosine 12 of human calcitonin modulates its amyloid formation, membrane binding, and bioactivity.

Irreversible aggregation greatly limits the bioavailability and therapeutic activity of peptide-based drugs, so preventing protein or peptide aggregation is a common issue in drug formulation. Human calcitonin (hCT), a peptide hormone secreted by thyroidal parafollicular cells, can regulate blood calcium levels and maintain bone structure. Hence, it can be used as a treatment for metabolic bone diseases, such as osteoporosis and Paget's disease. However, hCT has a relatively high propensity to form amyloid fibrils that hinder its biological function and limit its pharmaceutical potential. In previous studies, we demonstrated, along with other research groups, that modifying specific residues of hCT is sufficient to prevent hCT aggregation. We proceeded to find the key residues that regulate the aggregation of hCT for a better understanding of the mechanism of hCT aggregation. In this work, we used amyloid propensity prediction software and found that Tyr12 may play a key role in regulating hCT aggregation. Thus, we propose three human calcitonin variants (Y12E, Y12P, Y12R) for hCT non-amyloidogenic substituents and examined the aggregation characteristics of variants using multiple biophysical techniques. Y12E showed the best anti-aggregation propensity and can work as inhibitor of hCT aggregation. We also found this residue is crucial for membrane binding and receptor binding. The data presented herein provides an overview of Tyr12 that should be carefully considered in peptide design.