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https://www.readbyqxmd.com/read/28227793/experimental-validation-of-neutron-activation-simulation-of-a-varian-medical-linear-accelerator
#1
S Morato, B Juste, R Miro, G Verdu, S Diez, S Morato, B Juste, R Miro, G Verdu, S Diez, B Juste, S Diez, R Miro, S Morato, G Verdu
This work presents a Monte Carlo simulation using the last version of MCNP, v. 6.1.1, of a Varian CLinAc emitting a 15MeV photon beam. The main objective of the work is to estimate the photoneutron production and activated products inside the medical linear accelerator head. To that, the Varian LinAc head was modelled in detail using the manufacturer information, and the model was generated with a CAD software and exported as a mesh to be included in the particle transport simulation. The model includes the transport of photoneutrons generated by primary photons and the (n, γ) reactions which can result in activation products...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28225881/zinc-and-metalloproteinases-2-and-9-what-is-their-relation-with-breast-cancer
#2
Aldenora Oliveira do Nascimento Holanda, Ana Raquel Soares de Oliveira, Kyria Jayanne Clímaco Cruz, Juliana Soares Severo, Jennifer Beatriz Silva Morais, Benedito Borges da Silva, Dilina do Nascimento Marreiro
Zinc is the catalytic component of proteins that regulate responses to DNA damage, intracellular signaling enzymes, and matrix metalloproteinases, which are important proteins in carcinogenesis. The objective of this review is to bring current information on the participation of zinc and matrix metalloproteinases types 2 and 9 in mechanisms involved in the pathogenesis of breast cancer. We conducted a literature review, in consultation with the PubMed, Lilacs, and Scielo databases. The zinc and cysteine residues are structural elements shared by all members of the family of matrix metalloproteinases, and these proteins appear to be involved in the propagation of various types of neoplasms, including breast cancer...
January 1, 2017: Revista da Associação Médica Brasileira
https://www.readbyqxmd.com/read/28225829/inhibition-of-arabidopsis-chloroplast-%C3%AE-amylase-bam3-by-maltotriose-suggests-a-mechanism-for-the-control-of-transitory-leaf-starch-mobilisation
#3
Jing Li, Wenxu Zhou, Perigio Francisco, Russell Wong, Dongke Zhang, Steven M Smith
Starch breakdown in leaves at night is tightly matched to the duration of the dark period, but the mechanism by which this regulation is achieved is unknown. In Arabidopsis chloroplasts, β-amylase BAM3 hydrolyses transitory starch, producing maltose and residual maltotriose. The aim of the current research was to investigate the regulatory and kinetic properties of BAM3. The BAM3 protein was expressed in Escherichia coli and first assayed using a model substrate. Enzyme activity was stimulated by treatment with dithiothreitol and was increased 40% by 2-10 μM Ca2+ but did not require Mg2+...
2017: PloS One
https://www.readbyqxmd.com/read/28225182/double-sequential-encrypted-targeting-sequence-a-new-concept-for-bone-cancer-treatment
#4
Gonzalo Villaverde, Valentina Nairi, Alejandro Baeza, Maria Vallet-Regi
The selective transportation of therapeutic agents to tumoral cells is usually achieved by their conjugation with targeting moieties able to recognize these cells. Unfortunately, simple and static targeting systems usually show selectivity lacks. Herein, double sequential encrypted targeting system is proposed as stimuli-responsive targeting analogue for selectivity enhancement. The system is able to recognize diseased bone tissue in first place, and once there, a hidden secondary targeting group is activated by the presence of an enzyme overproduced in the malignant tissue (cathepsin K), triggering the recognition of diseased cells...
February 22, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28225088/the-general-pts-component-hpr-determines-the-preference-for-glucose-over-mannitol
#5
Mangyu Choe, Young-Ha Park, Chang-Ro Lee, Yeon-Ran Kim, Yeong-Jae Seok
Preferential sugar utilization is a widespread phenomenon in biological systems. Glucose is usually the most preferred carbon source in various organisms, especially in bacteria where it is taken up via the phosphoenolpyruvate:sugar phosphotransferase system (PTS). The currently proposed model for glucose preference over non-PTS sugars in enteric bacteria including E. coli is strictly dependent on the phosphorylation state of the glucose-specific PTS component, enzyme IIA(Glc) (EIIA(Glc)). However, the mechanism of the preference among PTS sugars is largely unknown in Gram-negative bacteria...
February 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28225057/intracellular-drug-bioavailability-a-new-predictor-of-system-dependent-drug-disposition
#6
André Mateus, Andrea Treyer, Christine Wegler, Maria Karlgren, Pär Matsson, Per Artursson
Intracellular drug exposure is influenced by cell- and tissue-dependent expression of drug-transporting proteins and metabolizing enzymes. Here, we introduce the concept of intracellular bioavailability (Fic) as the fraction of extracellular drug available to bind intracellular targets, and we assess how Fic is affected by cellular drug disposition processes. We first investigated the impact of two essential drug transporters separately, one influx transporter (OATP1B1; SLCO1B1) and one efflux transporter (P-gp; ABCB1), in cells overexpressing these proteins...
February 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28224988/post-endocytic-sorting-of-plexin-d1-controls-signal-transduction-and-development-of-axonal-and-vascular-circuits
#7
Katja Burk, Erik Mire, Anaïs Bellon, Mélanie Hocine, Jeremy Guillot, Filipa Moraes, Yutaka Yoshida, Michael Simons, Sophie Chauvet, Fanny Mann
Local endocytic events involving receptors for axon guidance cues play a central role in controlling growth cone behaviour. Yet, little is known about the fate of internalized receptors, and whether the sorting events directing them to distinct endosomal pathways control guidance decisions. Here, we show that the receptor Plexin-D1 contains a sorting motif that interacts with the adaptor protein GIPC1 to facilitate transport to recycling endosomes. This sorting process promotes colocalization of Plexin-D1 with vesicular pools of active R-ras, leading to its inactivation...
February 22, 2017: Nature Communications
https://www.readbyqxmd.com/read/28224920/genetic-engineering-of-the-biosynthesis-of-glycinebetaine-leads-to-alleviate-salt-induced-potassium-efflux-and-enhances-salt-tolerance-in-tomato-plants
#8
Dandan Wei, Wen Zhang, Cuicui Wang, Qingwei Meng, Gang Li, Tony H H Chen, Xinghong Yang
Tomato (Solanum lycopersicum cv. 'Moneymaker') was transformed with the choline oxidase gene codA from Arthrobacter globiformis, which was modified to allow for targeting to both chloroplasts and the cytosol. Glycine betaine (GB) was accumulated in transformed plants, while no detectable GB was found in wild-type (WT) plants. Compared to WT plants, transgenic lines showed significantly higher photosynthetic rates (Pn) and antioxidant enzyme activities and lower reactive oxygen species (ROS) accumulation in the leaves when exposed to salt stress...
April 2017: Plant Science: An International Journal of Experimental Plant Biology
https://www.readbyqxmd.com/read/28224894/development-of-drug-delivery-systems-for-taxanes-using-ionic-gelation-of-carboxyacyl-derivatives-of-chitosan
#9
Yury A Skorik, Anton A Golyshev, Andreii S Kritchenkov, Ekaterina R Gasilova, Daria N Poshina, Amal J Sivaram, Rangasamy Jayakumar
Nanoparticles of two chitosan derivatives - N-succinyl-chitosan (SC) and N-glutaryl-chitosan (GC) - were developed as passive transport systems for taxanes (paclitaxel and docetaxel) using an ionic gelation technique with sodium tripolyphosphate. These nanoparticles had an apparent hydrodynamic diameter of 300-350nm, a ζ-potential of 25-31mV, an encapsulation efficiency of 21-26%, and a drug loading efficiency of 6-13%. DLS and SLS analysis shows that the nanoparticles have a unimodal size distribution and spherical form...
April 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28224676/transcriptional-regulation-of-hb-%C3%AE-and-hb-%C3%AE-through-nuclear-factor-e2-related-factor-2-nrf2-activation-in-human-vaginal-cells-a-novel-mechanism-of-cellular-adaptability-to-oxidative-stress
#10
Debarchana Saha, Swanand Koli, Kudumula Venkata Rami Reddy
PROBLEM: Hemoglobin (Hb), a major protein involved in transport of oxygen (O2 ), is expressed by erythroid lineages. Until recently, it was not known whether non-erythroid cells express Hb. The objective was to evaluate the expression and functional significance of Hb-α and Hb-β in human primary vaginal epithelial cells (hPVECs) and decipher downstream signaling. METHODS OF STUDY: RT-PCR, qRT-PCR, flow cytometry, Western blot, immunofluorescence were used to evaluate the expression of Hb-α, Hb-β, and nuclear factor E2-related factor-2(Nrf2) after hydrogen peroxide (H2 O2 ) induction...
February 21, 2017: American Journal of Reproductive Immunology: AJRI
https://www.readbyqxmd.com/read/28224655/rna-seq-analysis-of-transcriptional-change-in-the-freshwater-mussel-elliptio-complanata-after-environmentally-relevant-sodium-chloride-exposure
#11
Laura S Robertson, Heather S Galbraith, Deborah Iwanowicz, Carrie J Blakeslee, R Scott Cornman
To identify potential biomarkers of salt stress in a freshwater sentinel species, we examined transcriptional responses of the common mussel Elliptio complanata to controlled NaCl exposures. RNA-Seq of mantle tissue identified 481 transcripts differentially expressed in adult mussels exposed to 2 ppt NaCl (1.2 ppt chloride) for seven days, of which 290 had non-overlapping intervals. Differentially expressed gene categories included ion and transmembrane transport, oxidoreductase activity, maintenance of protein folding, and amino acid metabolism...
February 22, 2017: Environmental Toxicology and Chemistry
https://www.readbyqxmd.com/read/28224622/slc2a3-single-nucleotide-polymorphism-and-duplication-influence-cognitive-processing-and-population-specific-risk-for-attention-deficit-hyperactivity-disorder
#12
Sören Merker, Andreas Reif, Georg C Ziegler, Heike Weber, Ute Mayer, Ann-Christine Ehlis, Annette Conzelmann, Stefan Johansson, Clemens Müller-Reible, Indrajit Nanda, Thomas Haaf, Reinhard Ullmann, Marcel Romanos, Andreas J Fallgatter, Paul Pauli, Tatyana Strekalova, Charline Jansch, Alejandro Arias Vasquez, Jan Haavik, Marta Ribasés, Josep Antoni Ramos-Quiroga, Jan K Buitelaar, Barbara Franke, Klaus-Peter Lesch
BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a common, highly heritable neurodevelopmental disorder with profound cognitive, behavioral, and psychosocial impairments with persistence across the life cycle. Our initial genome-wide screening approach for copy number variants (CNVs) in ADHD implicated a duplication of SLC2A3, encoding glucose transporter-3 (GLUT3). GLUT3 plays a critical role in cerebral glucose metabolism, providing energy for the activity of neurons, which, in turn, moderates the excitatory-inhibitory balance impacting both brain development and activity-dependent neural plasticity...
February 22, 2017: Journal of Child Psychology and Psychiatry, and Allied Disciplines
https://www.readbyqxmd.com/read/28224335/evidence-of-colloidal-transport-of-pahs-during-column-experiments-run-with-contaminated-soil-samples
#13
Karim Benhabib, Marie-Odile Simonnot, Pierre Faure, Michel Sardin
Brownfield soils may contain high levels of organic pollutants particularly polycyclic aromatic hydrocarbons (PAHs). It is essential to predict their migration and fate and to evaluate the risk of transfer to sensitive targets, such as water resources, ecosystems and human health. In this study, soil samples have been taken from an experimental contaminated site of former steel activities located at Homecourt (Lorraine, France). These samples have been lixiviated in laboratory column in water-saturated condition at room temperature...
February 21, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28224023/evaluation-of-liver-cirrhosis-and-hepatocellular-carcinoma-using-protein-protein-interaction-networks
#14
Mohammad Javad Ehsani Ardakani, Akram Safaei, Afsaneh Arefi Oskouie, Hesam Haghparast, Mehrdad Haghazali, Hamid Mohaghegh Shalmani, Hassan Peyvandi, Nosratollah Naderi, Mohammad Reza Zali
AIM: In the current study, we analysised only the articles that investigate serum proteome profile of cirrhosis patients or HCC patients versus healthy controls. BACKGROUND: Increased understanding of cancer biology has enabled identification of molecular events that lead to the discovery of numerous potential biomarkers in diseases. Protein-protein interaction networks is one of aspect that could elevate the understanding level of molecular events and protein connections that lead to the identification of genes and proteins associated with diseases...
December 2016: Gastroenterology and Hepatology From Bed to Bench
https://www.readbyqxmd.com/read/28223989/ufgt-the-key-enzyme-associated-with-the-petals-variegation-in-japanese-apricot
#15
Xinxin Wu, Qinghua Gong, Xiaopeng Ni, Yong Zhou, Zhihong Gao
Japanese apricot (Prunus mume Sieb.et Zucc.) is an important ornamental plant in China. One of the traits of petals color variegation is attractive, but its formation mechanism is unclear. In our study, RNA-seq technology was employed to characterize the transcriptome response to the mutation of "Fuban Tiaozhi" associated with petals variegation in Japanese apricot. As a result, 4,579,040 (white-flowered, WF) and 7,269,883 (red-flowered, RF) reads were mapped to P. persica genes, while 5,006,676 (WF) and 7,907,436 (RF) were mapped to P...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28223978/function-and-regulation-of-the-c4-dicarboxylate-transporters-in-campylobacter-jejuni
#16
Marc M S M Wösten, Chris H A van de Lest, Linda van Dijk, Jos P M van Putten
C4-dicarboxylates are important molecules for the human pathogen C.jejuni, as they are used as carbon and electron acceptor molecules, as sugars cannot be utilized by this microaerophilic organism. Based on the genome analysis, C. jejuni may possess five different C4-dicarboxylate transporters: DctA, DcuA, DcuB, and two homologs of DcuC. Here, we investigated the regulation and function of various C4-dicarboxylate transporters in C. jejuni. Transcription of the dctA and dcuC homologs is constitutive, while dcuA and dcuB are both directly regulated by the two-component RacR/RacS system in response to limited oxygen availability and the presence of nitrate...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28223944/il-1%C3%AE-induced-downregulation-of-the-multifunctional-pdz-adaptor-pdzk1-is-attenuated-by-erk-inhibition-rxr%C3%AE-or-ppar%C3%AE-stimulation-in-enterocytes
#17
Min Luo, Sunil Yeruva, Yongjian Liu, Giriprakash Chodisetti, Brigitte Riederer, Manoj B Menon, Keisuke Tachibana, Takefumi Doi, Ursula E Seidler
Background: The PDZ adaptor protein PDZK1 modulates the membrane expression and function of a variety of intestinal receptors and ion/nutrient transporters. Its expression is strongly decreased in inflamed intestinal mucosa of mice and IBD patients. Aim and Methods: We investigated whether the inflammation-associated PDZK1 downregulation is a direct consequence of proinflammatory cytokine release by treating intestinal Caco-2BBE cells with TNF-α, IFN-γ, and IL-1β, and analysing PDZK1 promotor activity, mRNA and protein expression...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28223936/two-pore-channels-catalyzers-of-endolysosomal-transport-and-function
#18
REVIEW
Christian Grimm, Cheng-Chang Chen, Christian Wahl-Schott, Martin Biel
Two-pore channels (TPCs) have recently emerged as a novel class of non-selective cation channels in the endolysosomal system. There are two members in the human genome, TPC1 and TPC2. Studies with TPC knockout and knockdown models have revealed that these channels participate in the regulation of multiple endolysosomal trafficking pathways which when dysregulated can lead to or influence the development of a range of different diseases such as lysosomal storage, metabolic, or infectious diseases. TPCs have been demonstrated to be activated by different endogenous stimuli, PI(3,5)P2 and NAADP, and ATP has been found to block TPC activation via mTOR...
2017: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/28223907/comparative-bioavailability-and-utilization-of-particular-forms-of-b12-supplements-with-potential-to-mitigate-b12-related-genetic-polymorphisms
#19
REVIEW
Cristiana Paul, David M Brady
CONTEXT: Three natural forms of vitamin B12 are commercially available: methylcobalamin (MeCbl), adenosylcobalamin (AdCbl), and hydroxycobalamin (OHCbl), all of which have been shown in clinical studies to improve vitamin B12 status. They are bioidentical to the B12 forms occurring in human physiology and animal foods. In contrast, cyanocobalamin (CNCbl), a synthetic B12 compound used for food fortification and in some supplements, occurs only in trace amounts in human tissues as a result of cyanide intake from smoking or other sources...
February 2017: Integrative Medicine
https://www.readbyqxmd.com/read/28223797/fabrication-and-in-vitro-in-vivo-evaluation-of-amorphous-andrographolide-nanosuspensions-stabilized-by-d-%C3%AE-tocopheryl-polyethylene-glycol-1000-succinate-sodium-lauryl-sulfate
#20
Hongzhi Qiao, Lihua Chen, Tianqi Rui, Jingxian Wang, Ting Chen, Tingming Fu, Junsong Li, Liuqing Di
Andrographolide (ADG) is a diterpenoid isolated from Andrographis paniculata with a wide spectrum of biological activities, including anti-inflammatory, anticancer and hepatoprotective effects. However, its poor water solubility and efflux by P-glycoprotein have resulted in lower bioavailability. In this study, ADG nanosuspensions (ADG-NS) were prepared using a wet media milling technique followed by freeze drying. d-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS), a surfactant that inhibits P-glycoprotein function, and sodium lauryl sulfate were used as surface stabilizers...
2017: International Journal of Nanomedicine
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