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Chemical communication

T Cunha, M Mendes, F Ferreira da Silva, S Eden, G García, P Limão-Vieira
This work demonstrates that selective excision of hydrogen atoms at a particular site of the DNA base adenine can be achieved in collisions with electronegative atoms by controlling the impact energy. The result is based on analysing the time-of-flight mass spectra yields of potassium collisions with a series of labeled adenine derivatives. The production of dehydrogenated parent anions is consistent with neutral H loss either from selective breaking of C-H or N-H bonds. These unprecedented results open up a new methodology in charge transfer collisions that can initiate selective reactivity as a key process in chemical reactions that are dominant in different areas of science and technology...
January 14, 2018: Journal of Chemical Physics
Andreas Weigert, Andreas von Knethen, Dominik Fuhrmann, Nathalie Dehne, Bernhard Brüne
Macrophages are known for their versatile role in biology. They sense and clear structures that contain exogenous or endogenous pathogen-associated molecular patterns. This process is tightly linked to the production of a mixture of potentially harmful oxidants and cytokines. Their inherent destructive behavior is directed against foreign material or structures of 'altered self', which explains the role of macrophages during innate immune reactions and inflammation. However, there is also another side of macrophages when they turn into a tissue regenerative, pro-resolving, and healing phenotype...
January 9, 2018: Molecular Aspects of Medicine
Jennifer R Mendel, Sabeeh A Baig, Marissa G Hall, Michelle Jeong, M Justin Byron, Jennifer C Morgan, Seth M Noar, Kurt M Ribisl, Noel T Brewer
INTRODUCTION: US law requires disclosure of quantities of toxic chemicals (constituents) in cigarette smoke by brand and sub-brand. This information may drive smokers to switch to cigarettes with lower chemical quantities, under the misperception that doing so can reduce health risk. We sought to understand past brand-switching behavior and whether learning about specific chemicals in cigarette smoke increases susceptibility to brand switching. METHODS: Participants were US adult smokers surveyed by phone (n = 1,151, probability sample) and online (n = 1,561, convenience sample)...
2018: PloS One
Nathalie Marquet, Peter C Hubbard, José P da Silva, João Afonso, Adelino V M Canário
The importance of chemical communication in reproduction has been demonstrated in many marine broadcast spawners. However, little is known about the use of chemical communication by echinoderms, the nature of the compounds involved and their mechanism(s) of action. Here, the hypothesis that the sea cucumber Holothuria arguinensis uses chemical communication for aggregation and spawning was tested. Water conditioned by males, but not females, attracted both males and females; gonad homogenates and coelomic fluid had no effect on attraction...
January 10, 2018: Scientific Reports
Lisa Pfeiffer, Joachim Ruther, John Hofferberth, Johannes Stökl
According to current evolutionary theory, insect pheromones can originate from extant precursor compounds being selected for information transfer. This is exemplified by females of the parasitoid wasp Leptopilina heterotoma whose defensive secretion consisting mainly of (-)-iridomyrmecin has evolved secondary functions as cue to avoid other females during host search and as female sex pheromone. To promote our understanding of pheromone evolution from defensive secretions we studied the chemical ecology of Leptopilina clavipes...
January 10, 2018: Scientific Reports
Giovanna Gomes Lara, Marcelo Fernandes Cipreste, Gracielle Ferreira Andrade, Wellington Marcos da Silva, Edésia Martins Barros de Sousa
Recently, flufenamic acid (FFA) was discovered among fenamates as a free radical scavenger and gap junction blocker; however, its effects have only been studied in cancer cells. Normal cells in the surroundings of a tumor also respond to radiation, although they are not hit by it directly. This phenomenon is known as the bystander effect, where response molecules pass from tumor cells to normal ones, through communication channels called gap junctions. The use of the enhanced permeability and retention effect, through which drug-loaded nanoparticles smaller than 200 nm may accumulate around a tumor, can prevent the local side effect upon controlled release of the drug...
January 9, 2018: Bioengineering
Oussama Yahiaoui, Lukáš F Pašteka, Bernadette Judeel, Thomas Fallon
In this communication we detail a new, practical synthesis of bullvalene and variety of mono- and di-substituted analogues. This has been accomplished through cobalt-catalyzed [6+2] cycloaddition of cyclooctatetraene to alkynes, followed by photochemical di-π-methane rearrangement. The application of isomer network analysis, coupled with quantum chemical calculations, provides a powerful and automated tool for predicting the properties of bullvalene isomer networks.
January 5, 2018: Angewandte Chemie
Ilaria Piazza, Karl Kochanowski, Valentina Cappelletti, Tobias Fuhrer, Elad Noor, Uwe Sauer, Paola Picotti
Metabolite-protein interactions control a variety of cellular processes, thereby playing a major role in maintaining cellular homeostasis. Metabolites comprise the largest fraction of molecules in cells, but our knowledge of the metabolite-protein interactome lags behind our understanding of protein-protein or protein-DNA interactomes. Here, we present a chemoproteomic workflow for the systematic identification of metabolite-protein interactions directly in their native environment. The approach identified a network of known and novel interactions and binding sites in Escherichia coli, and we demonstrated the functional relevance of a number of newly identified interactions...
January 3, 2018: Cell
Xiao-Dong Song, Chen-Jian Liu, Shi-Hao Huang, Xiao-Ran Li, En Yang, Yi-Yong Luo
Quorum sensing (QS) is a means of cell-to-cell communication that regulates, via small signalling molecules, expression of a series of genes and controls multicellular behaviour in many bacterial species. The enzyme S-ribosylhomocysteine lyase (LuxS) transforms S-ribosylhomocysteine (SRH) into 4, 5-dihydroxy-2, 3-pentanedione (DPD), the precursor of the interspecies QS signalling molecule autoinducer-2 (AI-2). In this study, two LuxS-coding genes, luxS1 and luxS2, with 70% sequence identity were isolated from Lactobacillus plantarum YM-4-3, and overexpressed in Escherichia coli BL21 (DE3), and the protein products were purified successfully...
January 2, 2018: Protein Expression and Purification
Kamylla Balbuena Michelutti, Eva Ramona Pereira Soares, Denise Sguarizi-Antonio, Raul Cremonezi Piva, Yzel Rondon Súarez, Claudia Andrea Lima Cardoso, William Fernando Antonialli-Junior
The cuticle of social insects is a barrier against desiccation and a channel for chemical communication, two characteristics fundamental to the success of this group. The compounds present in the cuticle interact dynamically in order to achieve a balance between these two functions. Thus, viscosity correlates with waterproofing, whereas fluidity correlates with effective communication. Temperature variation can cause the cuticular hydrocarbon (CHC) layer of the cuticle to change in order to maintain body homeostasis...
January 2018: Journal of Thermal Biology
P R Pansara, P Y Raval, N H Vasoya, S N Dolia, K B Modi
This communication presents a detailed study on a Fe3+ modified CaCu3Ti4O12 cubic perovskite system (CaCu3-xTi4-xFe2xO12 with x = 0.0-0.7) by performing X-ray powder diffractometry, DC SQUID magnetization and 57Fe Mössbauer spectroscopy. The first ever Mössbauer studies on the system supported the reported peculiarity of the structure. Mössbauer analysis for the compositions x = 0.1, 0.3, and 0.5 suggest Fe3+ ions in two different environments. The site with larger quadrupole splitting corresponds to Fe3+ in the octahedral symmetry, while the site with lower chemical shift and quadrupole splitting belongs to Fe3+ in the square-planar (A'-) configuration...
January 3, 2018: Physical Chemistry Chemical Physics: PCCP
Wenjie Wang, Qingyun Cai, Fang Zhou, Jiali Liu, Xiaoliang Jin, Ping Ni, Meng Lu, Guangji Wang, Jingwei Zhang
Although metabolic reprogramming and redox imbalance are widely reported to be involved in chemo-resistance in cancer treatment, much more attention was paid to anti-cancer drug induced effect. Our previous studies showed that cancer cells can develop P-gp overexpression-mediated intrinsic drug resistance in the formation of 3D MCF-7 multi-cellular layers (MCLs) without any drug induction. However, whether metabolic reprogramming and redox imbalance functioned during this progress remained unrevealed. In our present study, LC-Q/TOF-MS and GC-MS were used in combination for analysing intracellular metabolites...
December 21, 2017: Redox Biology
Daniel Guillaume, Chantal Moussu, Frédéric de Geoffroy, Didier Chesneau, Matthieu Keller
Stallions show decreased sexual responses and activities during short days in winter. To evaluate the importance of sexual olfactory communication in horses, we tested whether sexual responses could be stimulated through various sexual olfactory stimulations in winter. To this end, we presented stallions with various olfactory stimulations (urine from mares at different stages of the reproductive cycle, urine from stallions or geldings, or chemically defined synthetic odorant) during the non-breeding season and measured their behavioral responses through (1) a test of olfactory investigation (olfactory investigation and flehmen behavior) and (2) a test of sexual activity in the context of semen collection for artificial insemination...
December 26, 2017: Physiology & Behavior
Corey M Rountree, John B Troy, Laxman Saggere
Photoreceptor degenerative diseases cause irreparable blindness through the progressive loss of photoreceptor cells in the retina. Retinal prostheses are an emerging treatment for photoreceptor degenerative diseases that seek to restore vision by artificially stimulating the surviving retinal neurons in the hope of eliciting comprehensible visual perception in patients. Current retinal prostheses have demonstrated success in restoring limited vision to patients using an array of electrodes to electrically stimulate the retina but face substantial physical barriers in restoring high acuity, natural vision to patients...
December 19, 2017: Journal of Visualized Experiments: JoVE
M V Calvo, H F Groba, G Martínez, C Sellanes, C Rossini, A González
The bronze bug, Thaumastocoris peregrinus Carpintero & Dellape (Heteroptera: Thaumastocoridae), is an exotic emerging pest in Eucalyptus commercial forests in South America, Africa and southern Europe. Information on the chemical communication system and reproductive ecology of this insect is scant, and it may be relevant for designing management strategies for eucalypt plantations. Adults and nymphs usually aggregate in the field, possibly by means of chemical signals. Males emit large amounts of 3-methyl-2-butenyl butyrate, which attracts conspecific adult males but not females...
December 23, 2017: Neotropical Entomology
Andrea Forgacsova, Jaroslav Galba, Ralph M Garruto, Petra Majerova, Stanislav Katina, Andrej Kovac
Neurotransmitters, small molecules widely distributed in the central nervous system are essential in transmitting electrical signals across neurons via chemical communication. Dysregulation of these chemical signaling molecules is linked to numerous neurological diseases including tauopathies. In this study, a precise and reliable liquid chromatography method was established with tandem mass spectrometry detection for the simultaneous determination of aspartic acid, asparagine, glutamic acid, glutamine, γ-aminobutyric acid, N-acetyl-l-aspartic acid, pyroglutamic acid, acetylcholine and choline in human brain tissue...
December 9, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Mette Sørensen, Elizabeth H J Neilson, Birger Lindberg Møller
Oximes (R1R2C = NOH) are nitrogen containing chemical constituents which are formed in species representing all kingdoms of life. In plants, oximes are positioned at important metabolic bifurcation points between general and specialized metabolism. The majority of plant oximes are amino acid-derived metabolites, formed by the action of a cytochrome P450 from the CYP79 family. Auxin, cyanogenic glucosides, glucosinolates and a number of other bioactive specialized metabolites including volatiles are produced from oximes...
December 21, 2017: Molecular Plant
Shun Hamada, Toshihisa Ohtsuka
Our brain functions rely on sophisticated communication between synapses in the nervous system. Most synapses utilize a specialized submembranous structure, the so-called 'active zone', for the efficient transmission of chemical signals. The presynaptic active zone plays pivotal roles in the precise regulation of neurotransmitter release from the nerve terminals in a temporally and spatially coordinated manner. During the last two decades, several active zone-specific proteins have been isolated and characterized, including Bassoon, Piccolo/Aczonin, RIM, Munc13-1, ELKS, and CAST...
December 21, 2017: Neuroscience Research
Peter Laux, Jutta Tentschert, Christian Riebeling, Albert Braeuning, Otto Creutzenberg, Astrid Epp, Valérie Fessard, Karl-Heinz Haas, Andrea Haase, Kerstin Hund-Rinke, Norbert Jakubowski, Peter Kearns, Alfonso Lampen, Hubert Rauscher, Reinhilde Schoonjans, Angela Störmer, Axel Thielmann, Uwe Mühle, Andreas Luch
Development and market introduction of new nanomaterials trigger the need for an adequate risk assessment of such products alongside suitable risk communication measures. Current application of classical and new nanomaterials is analyzed in context of regulatory requirements and standardization for chemicals, food and consumer products. The challenges of nanomaterial characterization as the main bottleneck of risk assessment and regulation are presented. In some areas, e.g., quantification of nanomaterials within complex matrices, the establishment and adaptation of analytical techniques such as laser ablation inductively coupled plasma mass spectrometry and others are potentially suited to meet the requirements...
December 22, 2017: Archives of Toxicology
Nadine Ehmann, David Owald, Robert J Kittel
In a constantly changing environment, neuronal circuits need to be updated and adjusted to elicit directed actions. Synaptic plasticity plays an important role in modulating such globally and locally acting networks. The active zone (AZ) is a protein-rich compartment of chemical synapses, where precisely orchestrated molecular interactions control synaptic vesicle (SV) fusion with the presynaptic membrane. The subsequent release of neurotransmitter substances onto postsynaptic receptor fields forms the basis of neuronal communication...
December 16, 2017: Neuroscience Research
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