Indexing cardiovascular and respiratory variables: allometric scaling principles

ObjectivesTo describe the allometric scaling principles underlying appropriate indexing of cardiovascular and respiratory measurements obtained in adult mammals, and to propose guidelines for indexing experimental cardiovascular and respiratory data.Database usedPubMed, using the terms ‘allometry’, ‘allometric’, ‘indexing’, ‘cardiovascular’ and ‘respiratory’.ConclusionsIndexing of cardiopulmonary variables is commonly used in attempts to account for the effects of body size on measurements and to standardize them. Some cardiopulmonary variables have been indexed using various functions of body mass in a process that often ignores the underlying relationship between the variable of interest and body size, as described in the allometry literature. This can result in a failure to ideally reduce the effect of body size on measurements in a manner that highlights differences. We review how commonly measured cardiopulmonary variables are related to body mass in mammalian species according to the allometry literature, and offer suggestions on how this information can be used to appropriately index cardiopulmonary variables in a simple and informative manner.     

Fundamentals of arrhythmogenic mechanisms and treatment strategies for equine atrial fibrillation

Atrial fibrillation (AF) is the most common pathological arrhythmia in horses. Although it is not usually a life-threatening condition on its own, it can cause poor performance and make the horse unsafe to ride. It is a complex multifactorial disease influenced by both genetic and environmental factors including exercise training, comorbidities or ageing. The interactions between all these factors in horses are still not completely understood and the pathophysiology of AF remains poorly defined. Exciting progress has been recently made in equine cardiac electrophysiology in terms of diagnosis and documentation methods such as cardiac mapping, implantable electrocardiogram (ECG) recording devices or computer-based ECG analysis that will hopefully improve our understanding of this disease. The available pharmaceutical and electrophysiological treatments have good efficacy and lead to a good prognosis for AF, but recurrence is a frequent issue that veterinarians have to face. This review aims to summarise our current understanding of equine cardiac electrophysiology and pathophysiology of equine AF while providing an overview of the mechanism of action for currently available treatments for equine AF.     

亚健康及不良生活习惯对心功能影响的实验研究

建立亚健康人群心功能的风险评估参数,为亚健康的干预提供实验依据。根据《非体力劳动者亚健康评估参考标准》的调查表以及生活习惯调查问卷筛选出40～59岁无心血管疾病的亚健康和健康女性人群,分别测定心功能各项指标。研究发现安静时亚健康组CO、SV均小于健康组,存在显著性差异;定量负荷后即刻CO、CI、SV、SI均小于健康组, SVR、HR均大于健康组,存在显著性差异。定量负荷后3min末两组指标无统计学意义。定量负荷后5min末,亚健康组CO、CI、SV、SI均小于健康组, SVR大于健康组,存在显著性差异。亚健康人群安静时CO、SV低于健康人群;定量负荷后即刻CI、SV、SI低于健康人群,可以考虑将这些指标作为评估心血管亚健康的风险因子。     

除草剂精克草星胁迫对牛蛙心脏功能和血红细胞的影响

采用半静态实验方法,研究不同浓度BDE209（0.1、1、10 mg·L-1）在胁迫1、3、7、15 d和清洁海水中释放3、7 d后,翡翠贻贝（Perna viridis）外套膜和内脏团超氧化物歧化酶（Superoxide Dismutase,SOD）活性、丙二醛（Malondialdehyde,MDA）含量和谷胱甘肽（Glutathione,GSH）含量的变化规律。结果表明,BDE209胁迫后,翡翠贻贝2组织SOD活性先是受到明显的诱导作用,之后随胁迫时间延长被显著性抑制（P〈0.01）;BDE209对翡翠贻贝外套膜MDA含量的影响呈诱导-抑制反复变化,对内脏团MDA含量的影响表现为明显的诱导效应,其中胁迫第3 d时的诱导率最高,为22.83%。翡翠贻贝外套膜GSH含量在BDE209胁迫初期就被显著诱导（P〈0.01）,随暴露时间延长诱导效应降低,在第15 d时被显著性抑制（P〈0.05）;BDE209可诱导内脏团GSH含量显著性增加（P〈0.05）,但随暴露浓度增加GSH含量明显降低。清水恢复阶段,在清洁海水中恢复3 d后,翡翠贻贝2组织MDA含量和GSH含量相对于对照组仍有显著性增加（P〈0.05）;而SOD活性总体在外套膜中受到抑制、内脏团中受到诱导,仅个别浓度组有所恢复。     

乳鼠心肌细胞的体外三维培养

【目的】探讨应用PLGA泡沫支架材料,在体外建造组织工程化心肌组织的可行性。【方法】采用顺序消化及差速贴壁法分离纯化乳鼠心肌细胞,将分离所得的心肌细胞接种于PLGA多孔支架材料上,观测复合体内心肌细胞的生长状况、超微结构、细胞代谢率及细胞组分的变化,并将其与正常心肌和二维培养的心肌细胞进行比较。【结果】复合体内的细胞具有心肌细胞的特殊超微结构,免疫组化显示其中的α-横纹肌肌动蛋白染色呈强阳性,与二维培养的细胞相比,细胞代谢更加旺盛。【结论】采用组织工程技术有可能在体外培育出组织工程化心肌组织。     

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.