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natural selection

Danielle Oliveira Dos Anjos, Eliomara Sousa Sobral Alves, Vinicius Tomaz Gonçalves, Sheila Suarez Fontes, Mateus Lima Nogueira, Ana Márcia Suarez-Fontes, João Batista Neves da Costa, Fabricio Rios-Santos, Marcos André Vannier-Santos
Natural products comprise valuable sources for new antiparasitic drugs. Here we tested the effects of a novel β-lapachone derivative on Trypanosoma cruzi parasite survival and proliferation and used microscopy and cytometry techniques to approach the mechanism(s) underlying parasite death. The selectivity index determination indicate that the compound trypanocidal activity was over ten-fold more cytotoxic to epimastigotes than to macrophages or splenocytes. Scanning electron microscopy analysis revealed that the R72 β-lapachone derivative affected the T...
October 12, 2016: International Journal for Parasitology, Drugs and Drug Resistance
M C M Conde, L A Chisini, R Sarkis-Onofre, H S Schuch, J E Nör, F F Demarco
The aim of this Scoping Study was to evaluate the survival rate and nature of tissue formed inside root canals of human Necrotic Immature Permanent Teeth (NIPT) under root canal revascularization (RCR). The search was performed in SciVerse Scopus(®) , PubMed/Medline, Web of Science(®) , BIREME and in grey literature up to November 2015. The keywords were selected using MeSH terms and DECs. Two independent reviewers scrutinized the records obtained considering specific inclusion criteria. The included studies were evaluated in accordance with a modified Arksey and O' Malley's framework...
October 22, 2016: International Endodontic Journal
Parker Magin, Rebecca Stewart, Allison Turnock, Amanda Tapley, Elizabeth Holliday, Nick Cooling
Underperforming trainees requiring remediation may threaten patient safety and are challenging for vocational training programs. Decisions to institute remediation are high-stakes-remediation being resource-intensive and emotionally demanding on trainees. Detection of underperformance requiring remediation is particularly problematic in general (family) practice. We sought to establish early-training assessment instruments predictive of general practice (GP) trainees' subsequently requiring formal remediation...
October 21, 2016: Advances in Health Sciences Education: Theory and Practice
Liliana Albertazzi, Luisa Canal, Rocco Micciolo, Fulvio Ferrari, Sebastiano Sitta, Iacopo Hachen
The study analyzes the existence of naturally biased associations in the general population between a series of musical selections and a series of quatrains. Differently from other studies in the field, the association is tested between complex stimuli involving literary texts, which increases the load of the semantic factors. The stimuli were eight quatrains taken from the same poem and eight musical clips taken from a classical musical version of the poem. The experiment was conducted in two phases. First, the participants were asked to rate 10 couples of opposite adjectives on a continuous bipolar scale when reading a quatrain or when listening to a musical clip; then they were asked to associate a given clip directly with the quatrains in decreasing order...
October 21, 2016: Perception
Daniel Nichol, Mark Robertson-Tessi, Peter Jeavons, Alexander R A Anderson
Non-genetic variation in phenotypes, or bet-hedging, has been observed as a driver of drug resistance in both bacterial infections and cancers. Here, we study how bet-hedging emerges in the genotype-phenotype mapping through a simple interaction model: a molecular switch. We use simple Chemical Reaction Networks to implement stochastic switches that map gene products to phenotypes and investigate the impact of structurally distinct mappings on the evolution of phenotypic heterogeneity. Bet-hedging naturally emerges within this model and is robust to evolutionary loss through mutations to both the expression of individual genes and to the network itself...
October 21, 2016: Genetics
Kaouther Majouli, Assia Hamdi, Kamel Msaada, Abderraouf Kenani
This study was carried out with the objective to investigate the antibacterial activity of Hertia cheirifolia L. extracts against Gram-positive and Gram-negative strains including Staphylococcus aureus (ATCC 6538), Bacillus subtilis (ATCC 6633), Bacillus licheniformis, Esherichia coli (ATCC 8739), Pseudomonas aeruginosa (ATCC 9027), Salmonella enterica (CIP 8039) and Salmonella typhimirium. The results of this antibacterial screening showed that the ethyl acetate (EtOAc) extracts had the best activity against the tested microorganisms...
October 18, 2016: Microbial Pathogenesis
M J Aguado-Romeo, S Benot-López, A Romero-Tabares
Electrochemotherapy is a therapeutic option for the treatment of cutaneous and subcutaneous metastases from melanoma and other tumors. The procedure consists of the administration of anticancer drugs followed by locally applied electrical impulses to achieve an effect known as electroporation, which facilitates entry into the cytosol of drugs that cannot cross the cell membrane. The aim of this review is to evaluate the evidence that supports the use of electrochemotherapy as a therapeutic strategy in melanoma...
October 18, 2016: Actas Dermo-sifiliográficas
Cristiane I Cerceau, Luiz C A Barbosa, Elson S Alvarenga, Antonio G Ferreira, Sérgio S Thomasi
α-Bisabolol is a natural terpene produced by Eremanthus erythropappus and is widely used in cosmetics and pharmaceuticals due to its anti-inflammatory, antibacterial and antimycotic properties. Due to these applications, a control of composition and authenticity of commercial oils rich in this terpene is required, resulting in a demand for new methodologies for quality control. In this work a rapid and efficient method for quantification of α-bisabolol in the essential oil of E. erythropappus (candeia) using (1)H NMR was developed, validated and compared to gas chromatography (GC) method...
December 1, 2016: Talanta
Lufeng Zhang, Haiyan Qin, Wanwan Cui, Yang Zhou, Jianxiu Du
The development of new detection methods for proteases activity assay is important in clinical diagnostics and drug development. In this work, a simple, label-free, and turn-on fluorescent sensor was fabricated for trypsin, a protease produced in the pancreas. Cytochrome c, a natural substance of trypsin, could be selectively cleaved by trypsin into heme-peptide fragment. The produced heme-peptide fragment exhibited an intensive catalytic role on the H2O2-mediated the oxidation of thiamine to form strong fluorescent thiochrome...
December 1, 2016: Talanta
Margarida Ferreira-Teixeira, Daniela Paiva-Oliveira, Belmiro Parada, Vera Alves, Vitor Sousa, Obinna Chijioke, Christian Münz, Flávio Reis, Paulo Rodrigues-Santos, Célia Gomes
BACKGROUND: High-grade non-muscle invasive bladder cancer (NMIBC) has a high risk of recurrence and progression to muscle-invasive forms, which seems to be largely related to the presence of tumorigenic stem-like cell populations that are refractory to conventional therapies. Here, we evaluated the therapeutic potential of Natural Killer (NK) cell-based adoptive immunotherapy against chemoresistant bladder cancer stem-like cells (CSCs) in a pre-clinical relevant model, using NK cells from healthy donors and NMIBC patients...
October 21, 2016: BMC Medicine
Anne-Sophie Dumas, Ludivine Taconnat, Evangelos Barbas, Guillem Rigaill, Olivier Catrice, Delphine Bernard, Abdelilah Benamar, David Macherel, Abdelhak El Amrani, Richard Berthomé
BACKGROUND: Higher plants have to cope with increasing concentrations of pollutants of both natural and anthropogenic origin. Given their capacity to concentrate and metabolize various compounds including pollutants, plants can be used to treat environmental problems - a process called phytoremediation. However, the molecular mechanisms underlying the stabilization, the extraction, the accumulation and partial or complete degradation of pollutants by plants remain poorly understood. RESULTS: Here, we determined the molecular events involved in the early plant response to phenanthrene, used as a model of polycyclic aromatic hydrocarbons...
October 21, 2016: BMC Genomics
Łukasz Jeleń, Adam Krzyżak, Thomas Fevens, Michał Jeleń
Grading of breast cancer malignancy is a key step in its diagnosis, which in turn helps to determine its prognosis and a course of treatment. In this paper, we consider the application of pattern recognition and image processing techniques to perform computer-assisted automatic breast cancer malignancy grading from cytological slides of fine needle aspiration biopsies. To determine a classification of the malignancy of the slide, a feature set is first determined from imagery of the slides. In this paper we investigated the nature of a wide set of features extracted from biopsy images to determine their discriminatory power and cross-correlation...
October 13, 2016: Computers in Biology and Medicine
Yohann Nédélec, Joaquín Sanz, Golshid Baharian, Zachary A Szpiech, Alain Pacis, Anne Dumaine, Jean-Christophe Grenier, Andrew Freiman, Aaron J Sams, Steven Hebert, Ariane Pagé Sabourin, Francesca Luca, Ran Blekhman, Ryan D Hernandez, Roger Pique-Regi, Jenny Tung, Vania Yotova, Luis B Barreiro
Individuals from different populations vary considerably in their susceptibility to immune-related diseases. To understand how genetic variation and natural selection contribute to these differences, we tested for the effects of African versus European ancestry on the transcriptional response of primary macrophages to live bacterial pathogens. A total of 9.3% of macrophage-expressed genes show ancestry-associated differences in the gene regulatory response to infection, and African ancestry specifically predicts a stronger inflammatory response and reduced intracellular bacterial growth...
October 20, 2016: Cell
Hélène Quach, Maxime Rotival, Julien Pothlichet, Yong-Hwee Eddie Loh, Michael Dannemann, Nora Zidane, Guillaume Laval, Etienne Patin, Christine Harmant, Marie Lopez, Matthieu Deschamps, Nadia Naffakh, Darragh Duffy, Anja Coen, Geert Leroux-Roels, Frederic Clément, Anne Boland, Jean-François Deleuze, Janet Kelso, Matthew L Albert, Lluis Quintana-Murci
Humans differ in the outcome that follows exposure to life-threatening pathogens, yet the extent of population differences in immune responses and their genetic and evolutionary determinants remain undefined. Here, we characterized, using RNA sequencing, the transcriptional response of primary monocytes from Africans and Europeans to bacterial and viral stimuli-ligands activating Toll-like receptor pathways (TLR1/2, TLR4, and TLR7/8) and influenza virus-and mapped expression quantitative trait loci (eQTLs)...
October 20, 2016: Cell
Shlomo Sasson
Activated peroxisome proliferator-activated receptor-δ (PPARδ) induces the expression of genes encoding enzymes that metabolize fatty acids and carbohydrate. Attempts to identify cellular activators of PPARδ produced large lists of various fatty acids and their metabolic derivatives; however, there is no consensus on specific and selective binding interactions of natural ligands with PPARδ. Most models on binding interactions within the ligand binding domain (LBD) of PPARδ have been derived from analyses of PPARδ-LBD crystals formed with synthetic low molecular weight ligands...
October 18, 2016: Biochimie
Richard A Manderville, Stacey D Wetmore
The formation of DNA adducts by the attack of intermediates derived from toxic substances at the C8 position of 2-deoxyguanosine (dG) is a common damaging event. Although the majority of studies on C8-dG adducts have focused on lesions containing a C8-N-C tether between the bulky moiety and the nucleobase, the formation of O-linked lesions with a similar tether topology and C-linked adducts involving direct C8-C connectivity have also been uncovered. Several studies have been done to try to better understand the structural impact and mutagenicity of O-linked and C-linked aryl C8-dG adducts, including lesions arising from unsubstituted and chloro substituted phenols, and the food mutagen ochratoxin A (OTA)...
October 21, 2016: Chemical Research in Toxicology
Kerry A Geiler-Samerotte, Yuan O Zhu, Benjamin E Goulet, David W Hall, Mark L Siegal
The protein-folding chaperone Hsp90 has been proposed to buffer the phenotypic effects of mutations. The potential for Hsp90 and other putative buffers to increase robustness to mutation has had major impact on disease models, quantitative genetics, and evolutionary theory. But Hsp90 sometimes contradicts expectations for a buffer by potentiating rapid phenotypic changes that would otherwise not occur. Here, we quantify Hsp90's ability to buffer or potentiate (i.e., diminish or enhance) the effects of genetic variation on single-cell morphological features in budding yeast...
October 2016: PLoS Biology
Matthias Kleinmann, Adán Cabello
We show that, for any n, there are m-outcome quantum correlations, with m>n, which are stronger than any nonsignaling correlation produced from selecting among n-outcome measurements. As a consequence, for any n, there are m-outcome quantum measurements that cannot be constructed by selecting locally from the set of n-outcome measurements. This is a property of the set of measurements in quantum theory that is not mandatory for general probabilistic theories. We also show that this prediction can be tested through high-precision Bell-type experiments and identify past experiments providing evidence that some of these strong correlations exist in nature...
October 7, 2016: Physical Review Letters
Allegra T Aron, Morten O Loehr, Jana Bogena, Christopher J Chang
Iron is essential for sustaining life, as its ability to cycle between multiple oxidation states is critical for catalyzing chemical transformations in biological systems. However, without proper regulation, this same redox capacity can trigger oxidative stress events that contribute to aging along with diseases ranging from cancer to cardiovascular and neurodegenerative disorders. Despite its importance, methods for monitoring biological iron bound weakly to cellular ligands-the labile iron pool-to generate a response that preserves spatial and temporal information remain limited, owing to the potent fluorescence quenching ability of iron...
October 21, 2016: Journal of the American Chemical Society
Xiao-Feng Xiong, Hang Zhang, Christina R Underwood, Kasper Harpsøe, Thomas J Gardella, Mie F Wöldike, Michael Mannstadt, David E Gloriam, Hans Bräuner-Osborne, Kristian Strømgaard
G proteins are key mediators of G protein-coupled receptor signalling, which facilitates a plethora of important physiological processes. The cyclic depsipeptides YM-254890 and FR900359 are the only known specific inhibitors of the Gq subfamily of G proteins; however, no synthetic route has been reported previously for these complex natural products and they are not easily isolated from natural sources. Here we report the first total synthesis of YM-254890 and FR900359, as well as of two known analogues, YM-385780 and YM-385781...
November 2016: Nature Chemistry
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