515 research outputs found
Xylodiol from Xylopia langsdorfiana induces apoptosis in HL60 cells
Coordenação de Aperfeiçoamento de Pessoal de NĂvel Superior (CAPES)Fundação de Amparo Ă Pesquisa do Estado de SĂŁo Paulo (FAPESP)An atisane diterpene was isolated from Xylopia langsdorfi ana St. Hilaire & Tulasne, Annonaceae, leaves, ent-atisane-7 alpha, 16 alpha-diol (xylodiol). Preliminary study showed that xylodiol was cytotoxic and induced differentiation on human leukemia cell lines. However, the molecular mechanisms of xylodiol-mediated cytotoxicity have not been fully defined. Thus, we investigated the anti-tumor effect of xylodiol in human leukemia HL60 cell line. Xylodiol induced apoptosis and necrosis. HL60 cells treated with xylodiol showed biochemical changes characteristic of apoptosis, including caspases-8, -9 and -3 activation and loss of mitochondrial transmembrane potential (Delta psi(m)). However, there was a condensation rather than swelling of mitochondria. Moreover, the formation of condensed mitochondria and the loss of Delta psi(m) occurred downstream of caspase activation. Cyclosporine A did not protect HL60 cells from the cytotoxic effects of xylodiol, suggesting that the loss of Delta psi(m) is a late event in xylodiol-induced apoptosis. Oxidative stress was involved in xylodiol-induced apoptosis. Thus, we conclude that activated caspases cleave cellular proteins resulting in mitochondrial damage leading to mitochondrial condensation, loss of Delta psi(m) and ROS release from the mitochondria. ROS can further induce and maintain a collapse of Delta psi(m) leading to cellular damage through oxidation of lipids and proteins resulting in apoptotic cell death.21610351042Coordenação de Aperfeiçoamento de Pessoal de NĂvel Superior (CAPES)Fundação de Amparo Ă Pesquisa do Estado de SĂŁo Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de NĂvel Superior (CAPES)Fundação de Amparo Ă Pesquisa do Estado de SĂŁo Paulo (FAPESP
O ĂŤndice de Eficácia do Barorreflexo na Estratificação de Risco de Doentes com InsuficiĂŞncia CardĂaca CrĂłnica Candidatos Ă TerapĂŞutica de Ressincronização CardĂaca
INTRODUCTION:
Baroreflex function is an independent marker of prognosis in heart failure (HF). However, little is known about its relation to response to cardiac resynchronization therapy (CRT). The aim of this study is to assess arterial baroreflex function in HF patients who are candidates for CRT.
METHODS:
The study population consisted of 25 patients with indication for CRT, aged 65±10 years, NYHA functional class ≥III in 52%, QRS width 159±15 ms, left ventricular ejection fraction (LVEF) 29±5%, left ventricular end-systolic volume (LVESV) 150±48 ml, B-type natriuretic peptide (BNP) 357±270 pg/ml, and peak oxygen consumption (peak VO2) 18.4±5.0 ml/kg/min. An orthostatic tilt test was performed to assess the baroreflex effectiveness index (BEI) by the sequence method. This group was compared with 15 age-matched healthy individuals.
RESULTS:
HF patients showed a significantly depressed BEI during tilt (31±12% vs. 49±18%, p=0.001). A lower BEI was associated with higher BNP (p=0.038), lower peak VO2 (p=0.048), and higher LVESV (p=0.031). By applying a cut-off value of 25% for BEI, two clusters of patients were identified: lower risk cluster (BEI >25%) QRS 153 ms, LVESV 129 ml, BNP 146 pg/ml, peak VO2 19.0 ml/kg/min; and higher risk cluster (IEB ≤25%) QRS 167 ms, LVESV 189 ml, BNP 590 pg/ml, peak VO2 16.2 ml/kg/min.
CONCLUSIONS:
Candidates for CRT show depressed arterial baroreflex function. Lower BEI was observed in high-risk HF patients. Baroreflex function correlated closely with other clinical HF parameters. Therefore, BEI may improve risk stratification in HF patients undergoing CRT.info:eu-repo/semantics/publishedVersio
Variability of RNA quality extracted from biofilms of foodborne pathogens using different kits impacts mRNA quantification by qPCR
The biofilm formation by foodborne pathogens is known to increase the problem related with surface disinfection procedure in the food processing environment and consequent transmission of these pathogens into the population. Messenger RNA has been increasingly used to understand the action and the consequences of disinfectants in the virulence on such biofilms. RNA quality is an important requirement for any RNA-based analysis since the quality can impair the mRNA quantification. Therefore, we evaluated five different RNA extraction kits using biofilms of the foodborne pathogens Listeria monocytogenes, Escherichia coli, and Salmonella enterica. The five kits yielded RNA with different quantities and qualities. While for E. coli the variability of RNA quality did not affect the quantification of mRNA, the same was not true for L. monocytogenes or S. enterica. Therefore, our results indicate that not all kits are suitable for RNA extraction from bacterial biofilms, and thus, the selection of RNA extraction kit is crucial to obtain accurate and meaningful mRNA quantification.AF and JCB acknowledge the financial support of individual grants SFRH/BD/62359/2009 and SFRH/BD/66250/2009, respectively. The authors acknowledge the gift of bacterial strains to Joana Azeredo and Maria Olivia Pereira.
Molecular and cellular mechanisms underlying the evolution of form and function in the amniote jaw.
The amniote jaw complex is a remarkable amalgamation of derivatives from distinct embryonic cell lineages. During development, the cells in these lineages experience concerted movements, migrations, and signaling interactions that take them from their initial origins to their final destinations and imbue their derivatives with aspects of form including their axial orientation, anatomical identity, size, and shape. Perturbations along the way can produce defects and disease, but also generate the variation necessary for jaw evolution and adaptation. We focus on molecular and cellular mechanisms that regulate form in the amniote jaw complex, and that enable structural and functional integration. Special emphasis is placed on the role of cranial neural crest mesenchyme (NCM) during the species-specific patterning of bone, cartilage, tendon, muscle, and other jaw tissues. We also address the effects of biomechanical forces during jaw development and discuss ways in which certain molecular and cellular responses add adaptive and evolutionary plasticity to jaw morphology. Overall, we highlight how variation in molecular and cellular programs can promote the phenomenal diversity and functional morphology achieved during amniote jaw evolution or lead to the range of jaw defects and disease that affect the human condition
Bioremoval of diethylketone by the synergistic combination of microorganisms and clays : uptake, removal and kinetic studies
The performance of two bacteria, Arthrobacter viscosus and Streptococcus equisimilis, and the effect of the interaction of these bacteria with four different clays on the retention of diethylketone were investigated in batch experiments. The uptake, the removal percentages and the kinetics of the processes were determined. S. equisimilis,by itself, had the best performance in terms of removal percentage, for all the initial diethylketone concentrations tested: 200, 350 and 700 mg/L. The uptake values are similar for both bacteria. A possible mechanism to explain the removal of diethylketone includes its degradation by bacteria, followed by the adsorption of the intermediates/sub-products by the functional groups present on the cells surfaces. The assays performed with bacteria and clays indicated that the uptake values are similar despite of the clay used, for the same microorganism and mass of clay, but in general higher values are reached when S. equisimilis is used, compared to A. viscosus. Kinetic data were described by pseudo-first and pseudo-second order models.The authors would like to gratefully acknowledge the financial support of this project by the Fundacao para a Ciencia e Tecnologia, Ministerio da Ciencia e Tecnologia, Portugal and co-funding by FSE (programme QREN-POPH). Cristina Quintelas thanks FCT for a post-doc grant. The authors would like also to thank Minas de Barqueiros, S. A., Prof. Rui Boaventura (FEUP-Portugal) and Prof. Isabel Correia Neves (Dep Quimica, UM, Portugal) who gently offered the clays
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Factors associated with unintended pregnancy in Brazil: cross-sectional results from the Birth in Brazil National Survey, 2011/2012
Background
Unintended pregnancy, a pregnancy that have been either unwanted or mistimed, is a serious public health issue in Brazil. It is reported for more than half of women who gave birth in the country, but the characteristics of women who conceive unintentionally are rarely documented. The aim of this study is to analyse the prevalence and the association between unintended pregnancy and a set of sociodemographic characteristics, individual-level variables and history of obstetric outcomes.
Methods
Birth in Brazil is a cross-sectional study with countrywide representation that interviewed 23,894 women after birth. The information about intendedness of pregnancy was obtained after birth at the hospital and classified into three categories: intended, mistimed or unwanted. Multinomial regression analysis was used to estimate the associations between intendedness of a pregnancy, and sociodemographic and obstetric variables, calculating odds ratios and 95 % confidence intervals. All significant variables in the bivariate analysis were included in the multinomial multivariate model and the final model retaining variables that remained significant at the 5 % level.
Results
Unintended pregnancy was reported by 55.4 % of postpartum women. The following variables maintained positive and significant statistical associations with mistimed pregnancy: maternal age < 20 years (OR = 1.89, 95 % CI: 1.68–2.14); brown (OR = 1.15, 95 % CI: 1.04–1.27) or yellow skin color (OR = 1.56, 95 % CI: 1.05–2.32); having no partner (OR = 2.32, 95 % CI: 1.99–2.71); having no paid job (OR = 1.15, 95 % CI: 1.04–1.27); alcohol abuse with risk of alcoholism (OR = 1.25, 95 % CI: 1.04–1.50) and having had three or more births (OR = 2.01, 95 % CI: 1.63–2.47). The same factors were associated with unwanted pregnancy, though the strength of the associations was generally stronger. Women with three or more births were 14 times more likely to have an unwanted pregnancy, and complication in the previous pregnancies and preterm birth were 40 % and 19 % higher, respectively. Previous neonatal death was a protective factor for both mistimed (OR = 0.61, 95 % CI: 0.44–0.85) and unwanted pregnancy (OR = 0.44, 95 % CI: 0.34–0.57).
Conclusions
This study confirms findings from previous research about the influence of socioeconomic and individual risk factors on unintended pregnancy. It takes a new approach to the problem by showing the importance of previous neonatal death, preterm birth and complication during pregnancy as risk factors for unintended pregnancy
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