Animals – ABC CARDIOL

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Editorial

Cardiology and the Cardiologist – Yesterday, Today and Tomorrow

Evandro Tinoco Mesquita et al. Aurea Lucia Alves de Azevedo Grippa de Souza

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Special Article

Multivariate Analysis for Animal Selection in Experimental Research

Renan Mercuri Pinto et al. Dijon Henrique Salomé de Campos Loreta Casquel Tomasi Antonio Carlos Cicogna … Katashi Okoshi Carlos Roberto Padovani

Background:

Several researchers seek methods for the selection of homogeneous groups of animals in experimental studies, a fact justified because homogeneity is an indispensable prerequisite for casualization of treatments. The lack of robust methods that comply with statistical and biological principles is the reason why researchers use empirical or subjective methods, influencing their results.

Objective:

To develop a multivariate statistical model for the selection of a homogeneous group of animals for experimental research and to elaborate a computational package to use it.

Methods:

The set of echocardiographic data of 115 male Wistar rats with supravalvular aortic stenosis (AoS) was used as an example of model development. Initially, the data were standardized, and became dimensionless. Then, the variance matrix of the set was submitted to principal components analysis (PCA), aiming at reducing the parametric space and at retaining the relevant variability. That technique established a new Cartesian system into which the animals were allocated, and finally the confidence region (ellipsoid) was built for the profile of the animals’ homogeneous responses. The animals located inside the ellipsoid were considered as belonging to the homogeneous batch; those outside the ellipsoid were considered spurious.

Results:

The PCA established eight descriptive axes that represented the accumulated variance of the data set in 88.71%. The allocation of the animals in the new system and the construction of the confidence region revealed six spurious animals as compared to the homogeneous batch of 109 animals.

Conclusion:

The biometric criterion presented proved to be effective, because it considers the animal as a whole, analyzing jointly all parameters measured, in addition to having a small discard rate.

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Artigo Original

Intermittent systolic overload promotes better myocardial performance in adult animals

Leonardo Augusto Miana et al. Renato S. Assad Maria C. D. Abduch Guilherme Seva Gomes … Ananda Rigo Nogueira Fernanda Santos Oliveira Bruna Lopes Telles Maria Teresa Souto Gustavo J. Silva Noedir A. G. Stolf

BACKGROUND: Corrected transposition of great arteries often evolves with right ventricular dysfunction. The ventricular preparation for anatomic correction in adult patients has produced disappointing results. OBJECTIVE: To assess right ventricular hypertrophy (RV) induced by conventional and intermittent pulmonary banding (PB) in adult animals. METHODS: Nineteen adult goats were divided into three groups: conventional (six animals), intermittent (six animals) and control (seven animals). The Conventional group underwent fixed PB with cardiac tape, while the intermittent group received PB adjustable device, which generated systolic overload for 12 hours, alternated with 12 hours of rest of RV. The pressures of the RV, pulmonary artery and aorta were measured throughout the study. Echocardiography was performed weekly. After four weeks, the animals were euthanized for morphological evaluation of the ventricles. The Control group was put to euthanasia for analysis at baseline. RESULTS: Pressure overload was lower in the intermittent group (p = 0.001), compared to the conventional group. There was an increase in the thickness of the RV of the Intermittent group measured by echocardiography compared to their baseline values (p < 0.05). The myocardial performance index in the RV group was better in the Intermittent group (p = 0.024), compared to the Conventional group. The groups stimulated showed increased muscle mass compared to the Control group (p = 0.001). There was no difference in myocardial water content. CONCLUSION: The intermittent BP developed hypertrophy of better performance, suggesting this protocol as the preferred method of ventricular preparation.

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Cardiology and the Cardiologist – Yesterday, Today and Tomorrow

Multivariate Analysis for Animal Selection in Experimental Research

Background:

Objective:

Methods:

Results:

Conclusion:

Intermittent systolic overload promotes better myocardial performance in adult animals

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Electronic Document Format (Vancouver)

Electronic Document Format (ABNT)

Electronic Document Format (APA)

Electronic Document Format (ISO)

Electronic Document Format (Vancouver)

Electronic Document Format (ABNT)

Electronic Document Format (APA)

Electronic Document Format (ISO)