44 research outputs found
Analysis of beta-dystroglycan in different cell models of senescence
The functional diversity of β-dystroglycan is attributable to its dual distribution, the plasma membrane, and the nucleus. In the plasma membrane, β-DG is a component of the dystrophin-associated protein complex. In the nucleus, β-DG assembles with the nuclear lamina and emerin. Recent findings indicate a role for β-DG in senescence, as its knockout in C2C12 myoblasts induces genomic instability and promotes the senescent state. This study analyzed the behavior of β-DG in three distinct models of senescence: chronologically aged fibroblasts, sodium butyrate (NaBu)-induced senescent fibroblasts, and fibroblasts from a Hutchinson–Gilford progeria syndrome (HGPS) patient. β-DG was found mainly in the nucleus in all the senescent cell types, with a certain mislocalization to the cytoplasm in HGPS and NaBu-treated fibroblasts. Furthermore, the full-length β-DG (43 kDa) and the cleaved intracellular domain (ICD; ~26 kDa) were identified. The ICD level increased in aged fibroblasts, but its yield was poor or virtually nonexistent in NaBU-induced and HGPS fibroblasts, respectively. Remarkably, β-DG was sequestered by progerin in HGPS cells, hindering its interaction with lamin A. In summary, the observed alterations in β-DG may be associated with the senescent state, and such findings will serve for future studies aimed at elucidating its role in senescence
SELECTION OF EUCALYPTUS CLONES AND ADJUSTMENT OF POTASSIUM DOSES FOR EXTENDED DROUGHT IN BAHIA SAVANNA
ABSTRACT The use of clones adapted to regions with water deficit caused by well-defined and prolonged dry periods, as happens in the western part Bahia, is a way to overcome water stress. The adjustment of potassium (K) also influences this aspect, because it regulates the opening and closing of stomata, impeding water loss by plants and making them more efficient in water use. Therefore, the aim of this study was to evaluate the performance of eucalyptus clones grown for energy production in response to potassium levels in soil and climate conditions, in the municipality of Luis Eduardo Magalhães, located in western Bahia state. A randomized block with four replications in a split plot was used as experimental design. Six eucalyptus clones (AEC-056, CEA-144, CEA-220, CEA-224, CEA-103 and CEA-1528) and four doses of K2O (0, 30, 60 and 120 kg ha-1) were tested. At two years old, clone 1528 showed greatest productivity, with the tallest height and trunk diameter, while 056 showed the lowest performance. Different K requirements were observed among eucalyptus clones for both growth and productivity
Predictors of mortality in critically ill patients with COVID-19 and diabetes
The COVID-19 pandemic has challenged the entire world, and patients with diabetes mellitus (DM) have been particularly affected. We aimed to evaluate predictors of mortality during the first 30 days of hospitalization in critically ill patients with COVID-19 and comorbid DM. This prospective study included 110 critically ill patients admitted with COVID-19 infection. Thirty-two (29%) patients had a previous diagnosis of DM. Clinical variables, laboratory tests, and vascular biomarkers, such as VCAM-1, syndecan-1, ICAM-1, angiopoietin-1, and angiopoeitin-2, were evaluated after intensive care unit (ICU) admission. A comparison was made between patients with and without DM. No difference in mortality was observed between the groups (48.7 vs 46.9%, P=0.861). In the multivariate Cox regression analysis, VCAM-1 levels at ICU admission (HR: 1 [1-1.001], P<0.006) were associated with death in patients with DM. Among patients with DM, advanced age (HR 1.063 [1.031-1.096], P<0.001), increased Ang-2/Ang-1 ratio (HR: 4.515 [1.803-11.308] P=0.001), and need for dialysis (HR: 3.489 [1.409-8.642], P=0.007) were independent predictors of death. Higher levels of VCAM-1 in patients with DM was better at predicting death of patients with severe COVID-19 and comorbid DM, and their cut-off values were useful for stratifying patients with a worse prognosis. Vascular biomarkers VCAM-1 and Ang-2/Ang-1 ratio were predictors of death in patients with severe COVID-19 and comorbid DM and those without DM. Additionally, kidney injury was associated with an increased risk of death
Poverty levels and children's health status: study of risk factors in an urban population of low socioeconomic level
To test the hypothesis that the low socioeconomic population living is shanty towns in Porto Alegre presents different levels of poverty which are reflected on its health status, a cross-sectional study was designed involving 477 families living in Vila Grande Cruzeiro, Porto Alegre, Brazil. The poverty level of the families was measured by using an instrument specifically designed for poor urban populations. Children from families living in extreme poverty (poorest quartile) were found to have higher infant mortality rate, lower birth weights, more hospitalizations, and higher malnutrition rates, in addition to belonging to more numerous families. Thus, the shanty town population of Porto Alegre is not homogeneous, and priority should be given to the more vulnerable subgroups.Para testar a hipótese de que a população de baixo nível socioeconômico apresenta diferentes níveis de pobreza que repercutem em seu estado de saúde, foi realizado estudo transversal envolvendo 477 famílias de uma população urbana pobre residente na Vila Grande Cruzeiro, em Porto Alegre, RS, Brasil. O nível de pobreza dessas famílias foi medido por meio de um instrumento especialmente elaborado para populações urbanas pobres. Crianças oriundas de famílias vivendo em extrema pobreza (quartil inferior) apresentaram maior taxa de mortalidade infantil, menor peso de nascimento, maior número de internações hospitalares e maiores índices de desnutrição, além de pertencerem a famílias mais numerosas. A população de baixo nível socioeconômico mostrou-se heterogênea em relação a diferentes indicadores de saúde. Concluiu-se que a identificação de subgrupos mais vulneráveis numa população permite concentrar as ações de saúde entre os mais necessitados
Phylogenomics and the rise of the angiosperms
Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods1,2. A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome3,4. Many studies have drawn on this foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins5,6,7. However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes8. This 15-fold increase in genus-level sampling relative to comparable nuclear studies9 provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade
