Effects of aflatoxin B1 on mitochondrial respiration,ROS generation and apoptosis in broiler cardiomyocytes

Aflatoxin B1 (AFB1) develops various toxic effects in the liver by impairing mitochondrial function, inducing cell apoptosis. However, little is focused on its toxicity to broiler cardiomyocytes (BCMs). Here, the mitochondrial membrane potential (MMP), reactive oxygen species (ROS) generation, cardiac troponin T (cTnT) location, apoptosis induced by AFB1, and antioxidative genes were investigated in BCMs. It was found that AFB1 evoked intracellular ROS generation, and induced apoptosis in BCMs. AFB1 treatment resulted in increased percentage of apoptotic cells, increased location range of cTnT in cytoplasm, upregulated messenger RNA (mRNA) expression of nuclear factor erythroid 2‐related factor 2 (Nrf2) and downregulated mRNA expressions of Mn‐superoxide dismutase in BCMs. These findings suggested AFB1 treatment caused significant cardiomyocyte damage and cardiotoxicity, impairment of mitochondrial functions, activated ROS generation, and induced apoptosis, and probably was involved in the Nrf2 signal pathway in BCMs.     

牛膝多糖对牛蛙心脏活动的影响

应用斯氏蛙心灌流方法,观察和分析牛膝多糖对离体蛙心的作用及机理。结果发现,10μg/mL的牛膝多糖溶液即可加强心肌的收缩能力,50μg/mL时差异极著(P0.01),以后随用药浓度的增加,振幅进一步增大,二者呈显著的量效关系。牛膝多糖溶液在一定浓度范围内不影响心率,但浓度升高到500μg/mL时可使心率增加,至1000μg/mL时收缩振幅和心率进一步加大,但随后出现心脏功能衰竭。研究时选择100μg/mL的牛膝多糖浓度,其正性肌力作用与β受体有关,与M受体无关。     

不同剂量替米考星对雏鸡心脏功能和呼吸的影响

本试验将70只45日龄的罗曼鸡随机分成对照组和试验Ⅰ~Ⅵ组,旨在探讨不同剂量替米考星对雏鸡心功能和呼吸的影响。结果显示,随着替米考星剂量的加大和给药时间的延长,Ⅴ组死亡2只,Ⅵ组死亡4只;心率(HR)由增加到逐渐恢复,但5 h后,Ⅵ组HR极显著低于对照组(P＜0.01);左心室收缩压(LVSP)和左室内压最大变化速率(±dp/dtmax)呈逐渐下降趋势,左心室舒张末压(LVEDP)则逐渐升高,给药5 h后,Ⅳ、Ⅴ和Ⅵ组LVSP极显著低于对照组、Ⅰ、Ⅱ和Ⅲ组(P＜0.01),Ⅴ和Ⅵ组极显著低于Ⅳ组(P＜0.01)。Ⅱ组LVEDP显著高于对照组和Ⅰ组(P＜0.05),Ⅲ和Ⅳ组显著高于Ⅱ组(P＜0.05),极显著高于对照组和Ⅰ组(P＜0.01)。Ⅴ、Ⅵ组极显著高于其他各组(P＜0.01);Ⅰ~Ⅴ组呼吸逐渐加深加快。5 h后,Ⅲ、Ⅳ和Ⅴ组呼吸率显著高于对照组、Ⅰ和Ⅱ组(P＜0.05),但Ⅵ组呼吸率极显著低于Ⅲ、Ⅳ和Ⅴ组(P＜0.01)。提示替米考星在治疗雏鸡疾病时饮水安全使用剂量为400~600 mg/L,超过800 mg/L时会对心肺功能产生明显影响。     

Anatomical features of ossa cordis in the Steller sea lion

Irregular triangular cartilage or bone fragments are sometimes found in the fibrous triangle of the heart. Ossa cordis and/or cartilago cordis has been demonstrated in various terrestrial animal species. Regarding marine mammals, sperm whales lack heart bones, and there have been no studies on bones or cartilage in pinniped hearts. Therefore, we examined the ossa cordis and/or cartilago cordis of the Steller sea lion. Eleven Steller sea lion hearts were examined morphologically and histologically. Before dissection, some hearts were imaged by CT to confirm the presence of ossa cordis or cartilago cordis. As a result, ossa cordis-like fragments were confirmed in four adults and one pup. All of the fragments were found at the right fiber triangle, and one adult had ossified tissue, including adipose tissue in the bone marrow cavity. The ossa cordis probably support the aorta because they surround the aorta as in other terrestrial animals. Steller sea lions can dive to a few hundred meters, but they need to rest on land frequently. Hence, their ossa cordis help maintain heart function during the tachycardia that occurs upon repeated surfacing and movements on land after diving in water.     

Outcome and prognostic factors in infective endocarditis in dogs: 113 cases (2005‐2020)

BackgroundFactors associated with outcome in dogs diagnosed with infective endocarditis (IE) are not well characterized.ObjectivesEvaluate outcome and prognostic factors in dogs with IE.AnimalsOne hundred and thirteen dogs with IE.MethodsMedical records for dogs that fulfilled the modified Duke criteria between 2005 and 2020 were retrospectively reviewed. Signalment, preexisting conditions, clinicopathologic findings, treatment regimen, and outcomes were recorded. Univariate logistic regression was performed to identify categorical factors associated with mortality, and then multivariate analysis was performed.ResultsDogs were categorized as survivors (n = 47), non‐survivors (n = 57), or lost to follow‐up (n = 9). Survival to discharge and at 1 month was documented in 79 (70%) of 113 and 56 (54%) of 104 dogs, respectively, with median survival time (MST) of 72 days. Risk factors associated with mortality included development of congestive heart failure (odds ratio [OR], 11.8; 95% confidence interval [CI], 1.4‐97.8), thromboembolic events (OR, 5.7; 95% CI, 2.3‐14.4), and acute kidney injury (OR, 6.2; 95% CI, 2.0‐18.8). Administration of antithrombotic medications was associated with survival (OR, 0.35; 95% CI, 0.13‐0.97). Dogs that were not treated with antithrombotics had MST of 92 days, whereas dogs treated with antithrombotics did not reach MST during the study period. The heart valves involved and etiologic agent identified did not correlate with outcome.Conclusion and Clinical ImportanceDogs with IE that had thromboembolic events, acute kidney injury, or congestive heart failure had higher risk of mortality. Administration of antithrombotics was associated with prolonged survival time.