ABSTRACT
The skipjack tuna (Katsuwonus pelamis) is a mesopredator fish species with seasonal abundance in waters off Taiwan. Regional ecological and life-history information has been historically lacking for this species. In recent years, stable isotope analysis (SIA) of carbon and nitrogen has been used to assess predator feeding ecology and broader ecosystem trophic dynamics. This study evaluated comparative skipjack feeding ecology in distinct regions off Taiwan, combining traditional stomach content analysis with SIA of individuals off western (n = 43; 2020) and eastern (n = 347; 2012-2014 and n = 167; 2020) Taiwan. The stomach content analysis showed the most important prey to be ponyfish (Photopectoralis bindus) in western Taiwan and epipelagic squids (Myopsina spp.) and carangids (Decapterus macrosoma;) in eastern Taiwan from 2012 to 2014 and epipelagic carangids (Decapterus spp.) and flying fishes (Cheilopogon spp.) in eastern Taiwan in 2020, suggesting that the skipjack tuna is a generalist predator across regions. In contrast, time-integrated diet estimates from Bayesian mixing models indicated the importance of cephalopods and crustaceans as prey, potentially demonstrating more mesopelagic feeding in less productive waters during skipjack migrations outside the study regions. Skipjack off western Taiwan had a slightly higher estimated trophic position than in the waters off eastern Taiwan, potentially driven by the varying nutrient-driven pelagic food web structures. Skipjack SI values increased with body size off eastern Taiwan but not in western waters, suggesting that opportunistic predation can still result in different predator-prey size dynamics between regions.
Subject(s)
Animal Feed/analysis , Fishes/classification , Gastrointestinal Contents/chemistry , Tuna/physiology , Animal Feed/classification , Animals , Bayes Theorem , Decapodiformes/classification , Food Chain , Nutritional Status , Predatory Behavior , TaiwanABSTRACT
Introdução: Atorvastatina 80 mg é recomendada a pacientes portadores de doença coronária para redução de eventos cardiovasculares, havendo controvérsia sobre as interações farmacocinéticas entre doses elevadas das estatinas e uso concomitante de clopidogrel, por compartilharem a mesma via de biotransformação. Este estudo avaliou os efeitos da terapia combinada atorvastatina/clopidogrel na farmacocinética da estatina e função plaquetária em pacientes com doença coronária estável, sob uso crônico e efetivo de estatina. Método: Os pacientes foram admitidos quatro vezes para internação (V1 a V4) em leito-dia. Sete dias (D) antes da primeira internação a estatina em uso foi suspensa. A seguir, receberam atorvastatina 80 mg (D1 a D22) e clopidogrel 75 mg/dia (D8 a D29). Em todas as V foram obtidas amostras de sangue em jejum para dosagens lipídicas, avaliação da função plaquetária (técnica da placa e cone) e quantificação dos níveis plasmáticos de atorvastatina (cromatografia líquida e espectrometria de massa). Resultados: A suspensão por uma semana da estatina modificou o perfil lipídico (P < 0,05 vs. basal), ocorrendo rápida melhora de todas as frações lipídicas após atorvastatina 80 mg (P < 0,005; V1 > V2, V3 e V4). A adesão plaquetária foi menor com clopidogrel isolado (P = 0,003; V4 < V1, V2 e V3), enquanto para a agregação houve menor valor com tratamento combinado atorvastatina/clopidogrel ou clopidogrel isolado comparado aos demais períodos (P < 0,0001; V3 e V4 < V1 e V2). O clopidogrel não modificou as concentrações de atorvastatina. Conclusão: Atorvastatina em alta dose não afetou as meias respostas plaquetárias ao clopidogrel; entretanto, curto período de suspensão da estatina piorou o perfil lipídico e a função plaquetária.
Background: Atorvastatin 80 mg is recommended in patientswith coronary artery disease to reduce cardiovascular events, however, there is controversy regarding the pharmacokinetic interactions between high doses of statins and the concomitant use of clopidogrel, since they share the same biotransformation pathway. This study evaluated theeffects of the atorvastatin/clopidogrel combination therapy on the pharmacokinetics of statins and on platelet function of patients with stable coronary artery disease receivingchronic statins. Method: Patients were admitted four times (V1 to V4) to a day-clinic. Statin was discontinued sevendays (D) before the first admission. Patients then received atorvastatin 80 mg (D1 to D22) and clopidogrel 75 mg/day (D8 to D29). Fasting blood samples were obtained at all time points for lipid measurements, platelet function tests (cone and plate technique), and quantification of atorvastatin plasma levels (liquid chromatography and mass spectrometry). Results: The discontinuation of statins for one weekchanged the lipid profile (P < 0.05 vs. baseline), with an early improvement of all lipid parameters after the administration of atorvastatin 80 mg (P < 0.005; V1 > V2, V3 and V4). Platelet adhesion was lower with clopidogrel alone (P = 0.003; V4 < V1, V2 and V3), whereas platelet aggregation values were lower following the atorvastatin/clopidogrel combination therapy or clopidogrel alone when compared to the other time points (P < 0.0001; V3 and V4 < V1 and V2). The use of clopidogrel did not affect atorvastatin serum levels. Conclusion: High-dose atorvastatin did not affectplatelet responses to clopidogrel, however the short-term statindiscontinuation worsened the lipid profile and platelet function.
