Bioaccumulation of arsenic and immunotoxic effect in white shrimp (Penaeus vannamei) exposed to trivalent arsenic.

Trivalent arsenic (As (III)) contamination in the marine environment can produce adverse effects in crustaceans. The present study investigated the chronic toxicity of As (III) in white shrimp (Penaeus vannamei) by analyzing the tissue bioaccumulation and non-specific immune responses. Shrimps were exposed to 0 (control), 50, 500, and 2500 µg/L of As (III) for 21 days. The results showed that the hepatopancreas was the main tissue of arsenic accumulation in white shrimp. The cumulative concentration of total arsenic and inorganic arsenic but not arsenobetaine was positively correlated with the exposure concentration. In vitro As (III) treatment (0-2500 µg/L) with haemocytes isolated from healthy shrimp did not cause the cytotoxicity, but this arsenic treatments inhibited the phagocytic rate and O2- production. Moreover, the decrease of total haemocyte count and the inhibition of phagocytic rate, phagocytic index, O2- production and phenoloxidase activity were observed in white shrimp under the exposure of As (III) over a period of 21 days. This study revealed that chronic As (III) stress could disturb arsenic metabolism and immune responses in P. vannamei.

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.

Positive Magnetic Resonance Imaging Evidence of Transient Global Amnesia Following the Use of Sildenafil.

Transient global amnesia (TGA) has been proposed as a possible adverse effect of sildenafil. There are rare cases in the literature, but none had strong evidence to support. Our case is the first to demonstrate a focal punctate diffusion-weighted imaging lesion at the right hippocampus after the use of sildenafil. This finding, which is suggestive of cytotoxic edema and is typical for TGA, may provide us evidence for the implication of sildenafil in TGA. We speculate that sildenafil may precipitate TGA by altering blood flow, inducing venous congestion or cortical spreading depression at the hippocampus.