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A dynamic energy budget (DEB) model integrating pCO 2 was used to describe ocean acidification (OA) effects on Atlantic surfclam, Spisula solidissima, bioenergetics. Effects of elevated pCO 2 on ingestion and somatic maintenance costs were simulated, validated, and adapted in the DEB model based upon growth and biological rates acquired during a 12-week laboratory experiment. Temperature and pCO 2 were projected for the next 100 years following the intergovernmental panel on climate change representative concentration pathways scenarios (2.6, 6.0, and 8.5) and used as forcing variables to project surfclam growth and reproduction. End-of-century water warming and acidification conditions resulted in simulated faster growth for young surfclams and more energy allocated to reproduction until the beginning of the 22nd century when a reduction in maximum shell length and energy allocated to reproduction was observed for the RCP 8.5 scenario., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

In this study, we assessed the Atlantic surfclam (Spisula solidissima) energy budget under different ocean acidification conditions (OA). During 12 weeks, 126 individuals were maintained at three different ρCO 2 concentrations. Every two weeks, individuals were sampled for physiological measurements and scope for growth (SFG). In the high ρCO 2 treatment, clearance rate decreased and excretion rate increased relative to the low ρCO 2 treatment, resulting in reduced SFG. Moreover, oxygen:nitrogen (O:N) excretion ratio dropped, suggesting that a switch in metabolic strategy occurred. The medium ρCO 2 treatment had no significant effects upon SFG; however, metabolic loss increased, suggesting a rise in energy expenditure. In addition, a significant increase in food selection efficiency was observed in the medium treatment, which could be a compensatory reaction to the metabolic over-costs. Results showed that surfclams are particularly sensitive to OA; however, the different compensatory mechanisms observed indicate that they are capable of some temporary resilience., (Published by Elsevier Ltd.)

Shellfish aquaculture is a widely practiced way of producing food for human consumption in coastal areas. When farming intertidal clams, farmers commonly protect young seedling clams from predatory losses by covering farmed plots with netting or screening. Recent discussion of the effectiveness of protective nets or screens and their environmental effects has raised questions concerning the utility of the practice. We provide data based on a review of more than 35 peer-reviewed articles, as well as our own research that demonstrates the efficacy of predator protection for clam farms in various habitats around the world. In addition, we evaluate the effects of screening on temperature, and comment on ancient practices of clam gardening as conducted in the Pacific Northwest., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Many nonsteroidal anti-inflammatory drugs act by inhibiting the cyclooxygenase activity of prostaglandin H2 synthase (PGHS), a key enzyme in the biosynthesis of prostaglandins. Gastric toxicity remains a serious problem with the current drugs, however. Recent advances in the understanding of PGHS now suggest two possible approaches to producing drugs with fewer side effects.

The accumulation of DNA strand breaks and activation of ADP-ribosyltransferase (ADPRT) have recently been associated with cellular differentiation. Murine erythroleukemia (MEL) cells undergo erythropoietic differentiation when exposed to dimethyl sulfoxide (Me2SO) and several studies have suggested that DNA strand scission induced by this agent is a prerequisite for expression of the differentiated phenotype. Me2SO induction of MEL cells has also been associated with increases in ADPRT activity in one study, but not in another. We have monitored the effects of Me2SO on DNA strand breaks in preformed and replicating MEL cell DNA. The results clearly demonstrate that DNA fragmentation is not detectable during Me2SO induction of MEL differentiation, even in the presence of 3-aminobenzamide, an inhibitor of ADPRT. Further, these results are consistent with an absence of detectable changes in both endogenous and total potential ADPRT activity during Me2SO-induced MEL differentiation. These findings would argue against Me2SO induction of DNA strand scission and ADPRT in MEL cells undergoing differentiation.

Cytosine arabinoside (Ara-C) is the most effective agent in the treatment of acute myelogenous leukemia. This agent incorporates in leukemic cell DNA, and the extent of this incorporation correlates with loss of clonogenic survival. The incorporated Ara-C residue behaves as a relative DNA chain terminator, and the extent of (Ara-C)DNA formation correlates with inhibition of DNA synthesis. The incorporation of Ara-C into DNA requires the formation of Ara-CTP, and previous measurements of this metabolite have also been correlated with cytotoxicity. Because it is clinically relevant to define biochemical parameters predictive of Ara-C cytotoxicity, the present studies were undertaken to determine the relationship among Ara-CTP pools, formation of (Ara-C)DNA, and loss of clonogenic survival. The results demonstrate that the incorporation of Ara-C into DNA is the single most powerful predictor of cell lethality. Furthermore, although there is a correlation between Ara-CTP pools or continuous cellular exposure to Ara-CTP and cell kill, these relationships are less significant than that obtained with formation of (Ara-C)DNA. The extent of Ara-C incorporation into DNA can be predicted by the product of the Ara-CTP level and time (T), thus supporting the concept that Ara-C incorporation is dependent on continuous exposure to the triphosphate metabolite. These findings support the formation of (Ara-C)DNA as a highly predictive parameter of lethal cellular events.