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Introdução: Alterações do sistema nervoso autônomo são fatores de risco independentes para eventos cardiocirculatórios, os quais podem ser estudados pela análise da variabilidade da frequência cardíaca (VFC). Objetivo: Investigar a influência dos fatores de risco para doenças cardiovasculares e dos fármacos vigentes sobre a modulação autonômica da frequência cardíaca de repouso. Métodos: Amostra composta por 23 adultos com pelo menos um fator de risco cardiovascular, com idade entre 50 e 70 anos. Foram realizadas anamneses e avaliações antropométricas. Na condição de repouso sentado, a frequência cardíaca (FC) e os intervalos R-R foram analisados nos domínios do tempo (FC e RMSSD), da frequência (LF, HF e LF/HF) e pelo plot de Poincaré (SD1, SD2 e SD1/SD2). Resultados: Houve correlação entre presença do sedentarismo e alterações dos índices LF(nu) e LF/HF (R= 0,479 e R= 0,439), bem como entre a quantidade de fatores de risco e a FC (R= 0,512). Conclusão: O sedentarismo está associado à hiperativação da modulação simpática, e um maior número de fatores de risco para doenças cardiovasculares está associado à elevação da FC de repouso, caracterizando maior estresse sobre o sistema cardiovascular. Já o uso do inibidor da enzima conversora de angiotensina II está relacionado às reduções da modulação simpática e ao balanço simpato-vagal, o que é um indicativo favorável para o controle da morbidade. Palavras-chave: Sistema Nervoso Autônomo; fatores de risco; doenças cardiovasculares. Introduction: Autonomic nervous system changes are independent risk factors for cardiocirculatory events, which can be studied by analysis of heart rate variability (HRV). Objective: To investigate the influence of risk factors for cardiovascular disease and medications on rest autonomic modulation of heart rate. Methods: A sample of 23 adults with at least one cardiovascular risk factor, aged 50 and 70 years. Case histories and anthropometric evaluations were conducted. In the sitting condition of rest, heart rate (HR) and RR intervals were analyzed in the time domain (HR and RMSSD), frequency (LF, HF and LF/ HF), and the Poincaré plot (SD1, SD2 and SD1/SD2). Results: There was a correlation between the presence of a sedentary lifestyle and changes in LF (nu) and LF/HF (R = 0.479 and R = 0.439), as well the number of risk factors and the FC (R = 0.512). Conclusion: A sedentary lifestyle is associated with hyperactivation of the sympathetic modulation, and a greater number of risk factors for cardiovascular disease is associated with elevated resting HR, characterizing increased stress on the cardiovascular system. But the Angiotensin II converting enzyme inhibitors is related to reductions in sympathetic modulation and sympathetic-vagal balance, which is a favorable indicator for morbidity's control.

Satellite DNAs (satDNAs) are tandemly repeated sequences that are usually located on the heterochromatin, and the entire collection of satDNAs within a genome is called satellitome. Primarily, these sequences are not under selective pressure and evolve by concerted evolution, resulting in elevated rates of divergence between the satDNA profiles of reproductive isolated species/populations. Here, we characterized two additional satellitomes of Characiformes fish (Colossoma macropomum and Piaractus mesopotamicus) that diverged approximately 30 million years ago, while still retaining conserved karyotype features. The results we obtained indicated that several satDNAs (50% of satellite sequences in P. mesopotamicus and 43% in C. macropomum) show levels of conservation between the analyzed species, in the nucleotide and chromosomal levels. We propose that long-life cycles and few genomic changes could slow down rates of satDNA differentiation.

Complete mitochondrial genomes of the characiform fishes Astyanax fasciatus, Astyanax altiparanae, Hoplias malabaricus (Karyomorph A) and the Gymnotiformes species Gymnotus sylvius and Gymnotus cuia were characterized in the present study. The whole mitogenomes varied from 16,400bp (A. fasciatus) to 17,730 bp (A. altiparanae) long and all of them consisted of 13 protein-coding genes, 22 tRNAs, 2 rRNAs genes, a control region, and origin of light-strand replication. The gene order was similar among all the analyzed species. The nucleotide content of all mitogenomes was also similar, with 29.58-30.95% for A, 27.02-28.65% for T, 26.29-29.99% for C, and 14.41-15.67% for G.

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