Early changes in contractility indices and fibrosis in two minimally invasive congestive heart failure models

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOHeart failure is a common and often fatal disease. Numerous animal models are used to study its aetiology, progression and treatment. This article aims to demonstrate two minimally invasive models of congestive heart failure in a rabbit model and a precise method to assess cardiac performance. Methods: Fifty New Zealand White rabbits underwent cervicotomy incision and were then divided into three groups. Aortic regurgitation (AR group) was induced in 17 animals by catheter lesion through the right carotid artery, proximal aortic constriction (AC group) was created in 17 animals by metallic clip placement in the ascending aorta through a neck incision, while 16 animals served as controls (CO group). Eight weeks later, myocardial function and contractility indices were assessed by sonomicrometry crystals. Hearts were then collected for morphometric measurements and left ventricular tissues were subjected to immunohistochemical analysis of fibrosis, necrosis and apoptosis. Statistical analysis was by analysis of variance (ANOVA) with a Dunnett's post hoc test or by Kruskal-Wallis test with Dunn's post hoc test as appropriate, with significance at p < 0.05. Results: The model of aortic regurgitation indicated early stages of heart failure by volume overload with increased end-diastolic and end-systolic volumes, stroke volume, cardiac output and pressure-volume loop areas. The elastance was higher in the control group compared with that in the AC and AR groups (131.00 +/- 51.27 vs 88.77 +/- 40.11 vs 75.29 +/- 50.70; p = 0.01). The preload recruitable stroke work was higher in the control group compared with that in the AC and AR groups (47.70 +/- 14.19 vs 33.87 +/- 7.46 vs 38.58 +/- 9.45; p = 0.01). Aortic constriction produced left ventricular concentric hypertrophy. Fibrosis appeared in both heart failure models and was elevated by aortic constriction when compared with that in controls. Necrosis and apoptosis indices were very low in all the groups. Clinical signs of congestive heart failure were not present. Conclusions: The two heart failure models we describe were relatively simple to create and maintain, minimally invasive, accurate, inexpensive and, importantly, had a low mortality rate. These models rapidly induced deterioration of contractility indices and onset of fibrosis, the hallmarks of early myocardial dysfunction associated with heart failure. Sonomicrometry assessments were able to detect early contractility changes prior to clinical signs372368375FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOsem informaçã

Seleção de híbridos diplóides (AA) de bananeira com base em três índices não paramétricos Selection of (AA) diploid banana hybrids using three non-parametric indices

Objetivou-se selecionar híbridos diplóides (AA) de bananeira com base em três índices não paramétricos, a fim de orientar a seleção e aumentar o aproveitamento da variabilidade existente no Banco de Germoplasma de Bananeira da Embrapa Mandioca e Fruticultura Tropical. Foram avaliados 11 híbridos, no delineamento de blocos ao acaso, com quatro repetições. As parcelas constituíram-se de seis plantas, espaçadas de 2,5 m x 2,5 m, tendo na bordadura plantas da cultivar Pacovan. Tomaram-se dados dos seguintes caracteres: altura da planta, diâmetro do pseudocaule, número de filhos na floração, número de folhas na floração, ciclo da planta do plantio à emissão do cacho, presença de pólen, número de pencas, número de frutos, comprimento do fruto e resistência à Sigatoka-amarela. As médias desses 10 caracteres foram empregadas no cálculo dos índices multiplicativos, de soma de classificação e da distância genótipo-ideótipo. Os dois híbridos de melhor desempenho geral, o SH3263 e o 1318-01, foram classificados, respectivamente, em primeiro e segundo lugares pelos índices multiplicativos e de soma de classificação, enquanto o índice da distância genótipo-ideótipo os classificou em primeiro e quarto lugares respectivamente. Embora os três índices tenham demonstrado uma boa correspondência entre o desempenho geral dos híbridos e a sua classificação, os índices multiplicativo e de soma de classificação propiciaram classificação mais adequada desses híbridos.<br>The objective of the present study was to select diploids (AA) hybrids of banana based on three non-parametric indices as to guide the selection and increase the use of the variability present in the Banana Germplasm Bank of Embrapa Cassava and Tropical Fruits. Eleven hybrids were evaluated in random blocks with four replicates. The plots consisted of six plants spaced 2.5 m x 2.5 m whereas the border rows were from the Pacovan cultivar. The following characteristics were evaluated: plant height, pseudostem diameter, number of suckers, number of leaves during flowering, plant cycle from planting to bunch emission, presence of pollen, number of hands, number of fruits, fruit length and yellow-Sigatoka resistance. The average of these ten characteristics was used for calculating the multiplicative indices of sum of classification and genotype-ideotype distance. The two hybrids presenting best global performance SH3263 and 1318-01 ranked respectively, first and second by the multiplicative indices and sum of classification whereas the genotype-ideotype distance index ranked them first and fourth . Although in general, all three indexes presented good coherence between general performance of the hybrids and their classification, the multiplicative and sum of classification indexes provided a more adequate classification of these hybrids

Correlações entre caracteres agronômicos em dois ciclos de seleção recorrente em milho-pipoca Correlations among agronomic traits in two recurrent selection cycles in popcorn

Com o propósito de monitorar o comportamento de blocos gênicos em diferentes gerações de seleção recorrente em milho pipoca, quantificaram-se as correlações fenotípica, genotípica e de ambiente entre caracteres agronômicos, em dois ciclos de seleção recorrente. O primeiro ciclo foi formado por famílias de irmãos completos e o segundo ciclo por famílias S1. Embora não significativa, em ambos os ciclos, houve correlação genotípica negativa entre capacidade de expansão e rendimento de grãos. Para o segundo ciclo, as maiores magnitudes de correlação genotípica positiva ocorreram entre rendimento de grãos, número de espigas sadias e estande, indicando a possibilidade de sucesso na seleção de uma ou outra, com base no rendimento de grãos. Embora não significativa e em baixa magnitude, houve acréscimo da correlação genotípica entre rendimento de grãos e capacidade de expansão do primeiro para o segundo ciclo, denotando aumento na concentração de alelos favoráveis na população.<br>This work was carried out to estimate environment, genotypic and phenotypic correlations among traits in two intrapopulational recurrent selection cycles in popcorn. The first cycle was composed by full sib families and the second cycle by S1 families. Seventy-five families of full sib and two hundred and twenty two families S1 were evaluated in randomized complete block design with two replicates in two environments. Although not statistically significant, genotypic correlation between grain yield and popping expansion was negative in both selection cycles. For the second cycle of recurrent selection, the highest positive estimates of genotypic correlations were found between: grain yield and number of ears and grain yield and stand, indicating the perspective of the success for selection based on grain yield. Although in less magnitude there was an increase in genotypic correlation between the grain yield and popping expansion from the first to the second cycle of recurrent selection, indicating increase in the favorable allele frequencies in both traits