Diversity of plant growth-promoting bacteria associated with sugarcane.

The sugarcane (Saccharum spp) presents economic importance, mainly for tropical regions, being an important Brazilian commodity. However, this crop is strongly dependent on fertilizers, mainly nitrogen (N). This study assessed the plant growth-promoting bacteria (PGPB) associated with sugarcane that could be used as a potential inoculant to the crop. We evaluated the genetic diversity of PGPB in the plant tissue of sugarcane varieties (RB 867515, RB 1011, and RB 92579). The primer BOX-A1R was used to differentiate the similar isolated and further sequencing 16S rRNA ribosomal gene. The 16S rRNA gene showed the presence of seven different genera distributed into four groups, the genus Bacillus, followed by Paenibacillus (20%), Burkholderia (14%), Herbaspirillum (6%), Pseudomonas (6%), Methylobacterium (6%), and Brevibacillus (3%). The molecular characterization of endophytic isolates from sugarcane revealed a diversity of bacteria colonizing this plant, with a possible biotechnological potential to be used as inoculant and biofertilizers.

Focal adhesion kinase governs cardiac concentric hypertrophic growth by activating the AKT and mTOR pathways.

The heart responds to sustained overload by hypertrophic growth in which the myocytes distinctly thicken or elongate on increases in systolic or diastolic stress. Though potentially adaptive, hypertrophy itself may predispose to cardiac dysfunction in pathological settings. The mechanisms underlying the diverse morphology and outcomes of hypertrophy are uncertain. Here we used a focal adhesion kinase (FAK) cardiac-specific transgenic mice model (FAK-Tg) to explore the function of this non-receptor tyrosine kinase on the regulation of myocyte growth. FAK-Tg mice displayed a phenocopy of concentric cardiac hypertrophy, reflecting the relative thickening of the individual myocytes. Moreover, FAK-Tg mice showed structural, functional and molecular features of a compensated hypertrophic growth, and preserved responses to chronic pressure overload. Mechanistically, FAK overexpression resulted in enhanced myocardial FAK activity, which was proven by treatment with a selective FAK inhibitor to be required for the cardiac hypertrophy in this model. Our results indicate that upregulation of FAK does not affect the activity of Src/ERK1/2 pathway, but stimulated signaling by a cascade that encompasses PI3K, AKT, mTOR, S6K and rpS6. Moreover, inhibition of the mTOR complex by rapamycin extinguished the cardiac hypertrophy of the transgenic FAK mice. These findings uncover a unique role for FAK in regulating the signaling mechanisms that governs the selective myocyte growth in width, likely controlling the activity of PI3K/AKT/mTOR pathway, and suggest that FAK activation could be important for the adaptive response to increases in cardiac afterload. This article is part of a Special Issue entitled "Local Signaling in Myocytes".

Efeitos do labetalol na resposta da pressão arterial ao esforço em pacientes hipertensos / Effects of labetalol on the response of arterial blood pressure to exercise in hypertensive patients

Nove pacientes do sexo feminino, portadores de hipertensao arterial primaria, com pressao diastolica entre 100 e 120mm Hg, foram submetidos a tratamento da pressao arterial com labetalol (bloqueador alfa e beta). Em todos, a pressao diastolica tornou-se menor que 95 mm Hg. Foram comparadas as respostas tensionais e a frequencia cardiaca apos exercicio em cicloergometro, antes e depois do tratamento. Houve diminuicao significativa da pressao sistolica em repouso como em todos os estagios do exercicio, apos o uso do medicamento. Conclue-se que o labetalol demonstrou, ao exercicio, acao "hipotensora" satisfatoria nas doses utilizadas para controle da hipertensao em repouso

Resposta cardiovascular de pacientes com miocardiopatia ao exercicio isometrico com dinamometro (hand-grip). / Cardiovascular response of patients with myocardial disease to isometric exercise with dynamometer (hand-grip)

Com o objetivo de estudar a resposta cardiovascular ao exercicio isometrico em miocardiopatas, 34 pacientes portadores de miocardiopatia leve, moderada e acentuada foram submetidos a esforco com dinamometro de mola.Foram analisadas, para estes tres grupos e um grupo de normais, as diferencas de frequencia cardiaca (FC), pressao sistolica (delta PS) e diastolica (delta PD), entre pico de esforco e repouso. As diferencas de pressao nao foram significativas em qualquer grupo e, somente no grupo de individuos com miocardiopatia severa detectou-se maior variacao da frecuencia cardiaca, alem de correlacao linear entre as variacoes de pressao e frequencia cardiaca.Os varios elementos de adaptacao da resposta cardiovascular ao esforco em normais e miocardiopatas sao discutidos. Os autores concluem ser a frequencia cardiaca o mais importante destes elementos na adaptacao de individuos com miocardiopatia severa, quando submetidos ao exercicio isometrico