Characterization, prevalence, and risk factors of spontaneous and experimental atherosclerosis and vascular imaging in psittaciformes

Atherosclerosis is a degenerative and inflammatory vascular disease characterized by the accumulation of inflammatory cells, lipids, calcium, and formation of large fibrofatty lesions within the intima of arteries resulting in the disorganization of the arterial wall and stenosis of the lumen. Despite the importance of atherosclerosis in psittacine cardiology, there are few pathologic, clinical, and experimental investigations in psittaciformes. In order to expand the knowledge on psittacine atherosclerosis and provide fundamental observational information for future research, a series of studies was conducted on psittaciformes: 1) psittacine atherosclerotic lesions were characterized and categorized based on histopathology, histochemistry, transmission (TEM), and scanning electron microscopy (SEM) of 63 arterial samples, 2) the prevalence of clinically significant atherosclerotic lesions and the influence of several epidemiological variables were investigated in a multi-center case-control study on 7683 psittaciformes, 3) a diet-induced experimental model of atherosclerosis was developed and characterized in Quaker parrots (Myiopsitta monachus), and 4) a computed-tomography angiographic (CTA) protocol was developed and standardized to image the arterial lumen in Hispaniolan Amazon parrots (Amazona ventralis). Seven lesion types could be described in psittaciformes, which were similar to the human classification system. Digital image analysis, TEM, and SEM helped to further describe the lesions and refine the classification system. Atherosclerosis prevalence significantly increased with age, female sex, and the genera Psittacus, Amazona, and Nymphicus. Mild associations with reproductive, hepatic diseases, and myocardial fibrosis were also evidenced. Experimental induction of atherosclerosis with dietary 1% cholesterol lead to significant lesions within 2 months in Quaker parrots. An increase in arterial and plasma cholesterol and LDL was also documented. Reference limits for arterial luminal diameter of Hispaniolan Amazon parrots were determined by CTA and measurements revealed high intraobserver and interobserver agreement. In conclusion, psittacine atherosclerotic lesions displayed distinctive features that allowed the development of an effective classification system. The prevalence of advanced lesions (type IV-VI) was associated with several risk factors: age, female sex, and three psittacine genera. The Quaker parrot was found to be a suitable experimental model for psittacine atherosclerosis and dyslipidemia. Finally CTA was determined to be safe, reliable, and of potential diagnostic value in parrots for diagnosing stenotic atherosclerotic lesions

COMPARATIVE STUDY OF LIPOPROTEIN METABOLISM IN MAREK'S DISEASE SUSCEPTIBLE AND RESISTANT LINES

Marek's disease virus (MDV) infection causes atherosclerosis, and prior vaccination prevented the development of this disease. Two main strategies to resist Marek's disease (MD) have been demonstrated: vaccination and genetic resistance. However, little is known about the role of genetic resistance in the progression of MDV induced atherosclerosis. Atherosclerosis is primarily associated with lipoprotein metabolism. The purpose of this study was to investigate whether lipoprotein metabolisms are different in distinct MD susceptible and resistant chicken lines. Here, we studied different backgrounds of lipoprotein metabolism in the two lines and the changes of lipoprotein levels in response to MDV infection. The results showed that during chicken growth, the increase in total cholesterol was mostly due to the increasing (LDL+VLDL) in MD susceptible line, whereas it was mainly due to the elevating HDL in MD resistant line. These results suggested that different lipoprotein metabolisms exist in MD susceptible and resistant lines

An in vivo study of the uptake of cholesterol and radioactively-labelled albumin by cockerel aorta

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Avian Cardiovascular Disease Characteristics, Causes and Genomics

Cardiovascular disease is common in avian species and increasing commercial economic losses and demand for healthcare in the household/smallholding veterinary sector has resulted in increased research into these disorders. This in turn has highlighted the importance of breeding, genetic testing and possibilities for future prognostic and diagnostic testing. Research into avian cardiovascular genetics has rapidly accelerated. Previously much work was undertaken in mammals with information extrapolated and transferred to birds. Birds have also been used to model cardiovascular disease and therefore knowledge has become enriched due to this endeavour. Increasingly, the avian genome is being analysed in its own right. This work is assisted by the growing number of avian genomes being published. In 2015, Nature published news on the ‘Bird 10K’ project, which aims to sequence 10,500 extant bird species. By 2018, the Avian Genomes Consortium had published the sequences of 45 species/34 orders. This review investigates a range of avian cardiovascular disorders in order to highlight their pathologies, epidemiology and genetics in addition to avian models of heart disease. With the availability of more reference genomes, increases in the number and magnitude of avian studies and more advanced technologies, the genetics behind avian cardiovascular disorders is being unravelled