2,621 research outputs found
Vitamin D predicts all-cause and cardiac mortality in females with suspected acute coronary syndrome: a comparison with brain natriuretic peptide and high-sensitivity C-reactive protein
Vitamin D may not only reflect disease but may also serve as a prognostic indicator. Our aim was to assess the gender-specific utility of vitamin D measured as 25-hydroxy-vitamin D [25(OH)D] to predict all-cause and cardiac death in patients with suspected acute coronary syndrome (ACS) and to compare its prognostic utility to brain natriuretic peptide (BNP) and high-sensitivity C-reactive protein (hsCRP). Blood samples were harvested on admission in 982 patients. Forty percent were women (65.9 ± 12.6 years). Mortality was evaluated in quartiles of 25(OH)D, BNP, and hsCRP, respectively, during a 5-year follow-up, applying univariate and multivariate analyses. One hundred and seventy-three patients died; 78 were women. In 92 patients (37 women), death was defined as cardiac. In women, the univariate hazard ratio (HR) for total death of 25(OH)D in Quartile (Q) 2 versus Q1, Q3 versus Q1, and Q4 versus Q1 was 0.55 (95% CI 0.33–0.93), 0.29 (95% CI 0.15–0.55), and 0.13 (95% CI 0.06–0.32), respectively. In females, it was an independent predictor of total and cardiac death, whereas BNP and hsCRP were less gender-specific. No gender differences in 25(OH)D were noted in a reference material. Accordingly, vitamin D independently predicts mortality in females with suspected ACS.publishedVersio
Mechanisms of base selection by human single-stranded selective monofunctional uracil-DNA glycosylase
hSMUG1 (human single-stranded selective monofunctional uracil-DNA glyscosylase) is one of three glycosylases encoded within a small region of human chromosome 12. Those three glycosylases, UNG (uracil-DNA glycosylase), TDG (thymine-DNA glyscosylase), and hSMUG1, have in common the capacity to remove uracil from DNA. However, these glycosylases also repair other lesions and have distinct substrate preferences, indicating that they have potentially redundant but not overlapping physiological roles. The mechanisms by which these glycosylases locate and selectively remove target lesions are not well understood. In addition to uracil, hSMUG1 has been shown to remove some oxidized pyrimidines, suggesting a role in the repair of DNA oxidation damage. In this paper, we describe experiments in which a series of oligonucleotides containing purine and pyrimidine analogs have been used to probe mechanisms by which hSMUG1 distinguishes potential substrates. Our results indicate that the preference of hSMUG1 for mispaired uracil over uracil paired with adenine is best explained by the reduced stability of a duplex containing a mispair, consistent with previous reports with Escherichia coli mispaired uracil-DNA glycosylase. We have also extended the substrate range of hSMUG1 to include 5-carboxyuracil, the last in the series of damage products from thymine methyl group oxidation. The properties used by hSMUG1 to select damaged pyrimidines include the size and free energy of solvation of the 5-substituent but not electronic inductive properties. The observed distinct mechanisms of base selection demonstrated for members of the uracil glycosylase family help explain how considerable diversity in chemical lesion repair can be achieved
Angiopoietin-2 and angiopoietin-like 4 protein provide prognostic information in patients with suspected acute coronary syndrome
Background
Plasma levels of angiopoietin-2 (ANGPT2) and angiopoietin-like 4 protein (ANGPTL4) reflect different pathophysiological aspects of cardiovascular disease. We evaluated their association with outcome in a hospitalized Norwegian patient cohort (n = 871) with suspected acute coronary syndrome (ACS) and validated our results in a similar Argentinean cohort (n = 982).
Methods
A cox regression model, adjusting for traditional cardiovascular risk factors, was fitted for ANGPT2 and ANGPTL4, respectively, with all-cause mortality and cardiac death within 24 months and all-cause mortality within 60 months as the dependent variables.
Results
At 24 months follow-up, 138 (15.8%) of the Norwegian and 119 (12.1%) of the Argentinian cohort had died, of which 86 and 66 deaths, respectively, were classified as cardiac. At 60 months, a total of 259 (29.7%) and 173 (17.6%) patients, respectively, had died.
ANGPT2 was independently associated with all-cause mortality in both cohorts at 24 months [hazard ratio (HR) 1.27 (95% confidence interval (CI), 1.08–1.50) for Norway, and HR 1.57 (95% CI, 1.27–1.95) for Argentina], with similar results at 60 months [HR 1.19 (95% CI, 1.05–1.35) (Norway), and HR 1.56 (95% CI, 1.30–1.88) (Argentina)], and was also significantly associated with cardiac death [HR 1.51 (95% CI, 1.14–2.00)], in the Argentinean population.
ANGPTL4 was significantly associated with all-cause mortality in the Argentinean cohort at 24 months [HR 1.39 (95% CI, 1.15–1.68)] and at 60 months [HR 1.43 (95% CI, 1.23–1.67)], enforcing trends in the Norwegian population.
Conclusions
ANGPT2 and ANGPTL4 were significantly associated with outcome in similar ACS patient cohorts recruited on two continents.publishedVersio
Complement component 7 is associated with total- and cardiac death in chest-pain patients with suspected acute coronary syndrome
Background
Complement activation has been associated with atherosclerosis, atherosclerotic plaque destabilization and increased risk of cardiovascular events. Complement component 7 (CC7) binds to the C5bC6 complex which is part of the terminal complement complex (TCC/C5b-9). High-sensitivity C-reactive protein (hsCRP) is a sensitive marker of systemic inflammation and may reflect the increased inflammatory state associated with cardiovascular disease.
Aim
To evaluate the associations between CC7 and total- and cardiac mortality in patients hospitalized with chest-pain of suspected coronary origin, and whether combining CC7 with hsCRP adds prognostic information.
Methods
Baseline levels of CC7 were related to 60-months survival in a prospective, observational study of 982 patients hospitalized with a suspected acute coronary syndrome (ACS) at 9 hospitals in Salta, Argentina. A cox regression model, adjusting for conventional cardiovascular risk factors, was fitted with all-cause mortality, cardiac death and sudden cardiac death (SCD) as the dependent variables. A similar Norwegian population of 871 patients was applied to test the reproducibility of results in relation to total death.
Results
At follow-up, 173 patients (17.7%) in the Argentinean cohort had died, of these 92 (9.4%) were classified as cardiac death and 59 (6.0%) as SCD. In the Norwegian population, a total of 254 patients (30%) died. In multivariable analysis, CC7 was significantly associated with 60-months all-cause mortality [hazard ratio (HR) 1.26 (95% confidence interval (CI), 1.07–1.47) and cardiac death [HR 1.28 (95% CI 1.02–1.60)], but not with SCD. CC7 was only weakly correlated with hsCRP (r = 0.10, p = 0.002), and there was no statistically significant interaction between the two biomarkers in relation to outcome. The significant association of CC7 with total death was reproduced in the Norwegian population.
Conclusions
CC7 was significantly associated with all-cause mortality and cardiac death at 60-months follow-up in chest-pain patients with suspected ACS.publishedVersio
Prediction of leucine-rich nuclear export signal containing proteins with NESsential
The classical nuclear export signal (NES), also known as the leucine-rich NES, is a protein localization signal often involved in important processes such as signal transduction and cell cycle regulation. Although 15 years has passed since its discovery, limited structural information and high sequence diversity have hampered understanding of the NES. Several consensus sequences have been proposed to describe it, but they suffer from poor predictive power. On the other hand, the NetNES server provides the only computational method currently available. Although these two methods have been widely used to attempt to find the correct NES position within potential NES-containing proteins, their performance has not yet been evaluated on the basic task of identifying NES-containing proteins. We propose a new predictor, NESsential, which uses sequence derived meta-features, such as predicted disorder and solvent accessibility, in addition to primary sequence. We demonstrate that it can identify promising NES-containing candidate proteins (albeit at low coverage), but other methods cannot. We also quantitatively demonstrate that predicted disorder is a useful feature for prediction and investigate the different features of (predicted) ordered versus disordered NES’s. Finally, we list 70 recently discovered NES-containing proteins, doubling the number available to the community
Birth characteristics and risk of colorectal cancer: a study among Swedish twins
Type-2 diabetes increases the risk of colorectal cancer, and is also associated with low birth weight. However, we found no evidence of associations between birth characteristics and risk of colorectal cancer (m=248) among Swedish twins
A DFT Study of Structural and Electronic Properties of ZnS Polymorphs and its Pressure-Induced Phase Transitions
A systematic first-principles investigation, by using the density functional formalism with the nonlocal B3LYP approximation including a long-range dispersion correction, has been performed to calculate the structural and electronic properties and phase transitions under pressure of the three phases of ZnS (cubic zinc blende, ZB, hexagonal wurtzite, W, and cubic rock salt, RS). Numerical and analytical fittings have been carried out to determine the equilibrium unit cell geometry and equation of state parameters for the ZnS phases. The band structures, energy gap, density of states, and vibrational frequencies and their pressure dependences are investigated. The present results illustrate that both phases, W and ZB, present very similar enthalpy and the RS phase becomes thermodynamically more stable than ZB and W structures at 15.0 and 15.5 GPa, respectively. These phase transitions are accompanied by an increase of the first shell coordination number of Zn atom and by a cell volume collapse of 13.9% and 14.3% for ZB and W phases, respectively. The atomic contributions of the conduction and valence bands, as well the binding energy for the Zn 3d orbital have been obtained.The authors gratefully acknowledge the financial support of the Brazilian agencies CAPES, CNPq (573636/2008-7) and FAPESP (2013/07296-2 and 2013/19289-0). J.A. also acknowledges Generalitat Valenciana for Prometeo/2009/053 project, Ministerio de Ciencia e Innovación for project CTQ-2012-36253-C03-01CTO, and Programa de Cooperación Científica con Iberoamerica (Brasil), Ministerio de Educación (PHB2009-0065-PC)
To respond or not to respond - a personal perspective of intestinal tolerance
For many years, the intestine was one of the poor relations of the immunology world, being a realm inhabited mostly by specialists and those interested in unusual phenomena. However, this has changed dramatically in recent years with the realization of how important the microbiota is in shaping immune function throughout the body, and almost every major immunology institution now includes the intestine as an area of interest. One of the most important aspects of the intestinal immune system is how it discriminates carefully between harmless and harmful antigens, in particular, its ability to generate active tolerance to materials such as commensal bacteria and food proteins. This phenomenon has been recognized for more than 100 years, and it is essential for preventing inflammatory disease in the intestine, but its basis remains enigmatic. Here, I discuss the progress that has been made in understanding oral tolerance during my 40 years in the field and highlight the topics that will be the focus of future research
Visualizing the Needle in the Haystack: In Situ Hybridization With Fluorescent Dendrimers
In situ hybridization with 3DNA™ dendrimers is a novel tool for detecting low levels of mRNA in tissue sections and whole embryos. Fluorescently labeled dendrimers were used to identify cells that express mRNA for the skeletal muscle transcription factor MyoD in the early chick embryo. A small population of MyoD mRNA positive cells was found in the epiblast prior to the initiation of gastrulation, two days earlier than previously detected using enzymatic or radiolabeled probes for mRNA. When isolated from the epiblast and placed in culture, the MyoD mRNA positive cells were able to differentiate into skeletal muscle cells. These results demonstrate that DNA dendrimers are sensitive and precise tools for identifying low levels of mRNA in single cells and tissues
Surface modification of Ti-6Al-4V alloy for biomineralization and specific biological response: Part II, Alkaline phosphatase grafting
Titanium and its alloys are the most widespread
materials for the realization of orthopaedic and dental implants due to their good mechanical properties and biocompatibility.
Surface functionalization of biomaterials
aimed to improve and quicken implant integration and tissue regeneration is an active research field. The opportunity
to confer biological activity (ability to directly stimulate cells with proper biological signals) to the Ti6Al4 V alloy, previously modified to be bioactive from
the inorganic point of view (apatite precipitation), was explored in this research work. The alkaline phosphatase
(ALP) enzyme was grafted to metal surface via tresyl chloride activation, maintaining its activity. A synergistic effect between biological functionalization and inorganic
bioactivity was observed
- …