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Sample records for activation depend quantitatively

  1. Quantitative monitoring of activity-dependent bulk endocytosis of synaptic vesicle membrane by fluorescent dextran imaging

    Science.gov (United States)

    Clayton, Emma Louise; Cousin, Michael Alan

    2012-01-01

    Activity-dependent bulk endocytosis (ADBE) is the dominant synaptic vesicle (SV) retrieval mode in central nerve terminals during periods of intense neuronal activity. Despite this fact there are very few real time assays that report the activity of this critical SV retrieval mode. In this paper we report a simple and quantitative assay of ADBE using uptake of large flourescent dextrans as fluid phase markers. We show that almost all dextran uptake occurs in nerve terminals, using co-localisation with the fluorescent probe FM1-43. We also demonstrate that accumulated dextran cannot be unloaded by neuronal stimulation, indicating its specific loading into bulk endosomes and not SVs. Quantification of dextran uptake was achieved by using thresholding analysis to count the number of loaded nerve terminals, since monitoring the average fluorescence intensity of these nerve terminals did not accurately report the extent of ADBE. Using this analysis we showed that dextran uptake occurs very soon after stimulation and that it does not persist when stimulation terminates. Thus we have devised a simple and quantitative method to monitor ADBE in living neurones, which will be ideal for real time screening of small molecule inhibitors of this key SV retrieval mode. PMID:19766140

  2. The down-stream effects of mannan-induced lectin complement pathway activation depend quantitatively on alternative pathway amplification

    DEFF Research Database (Denmark)

    Harboe, Morten; Garred, Peter; Karlstrøm, Ellen

    2009-01-01

    Complement activation plays an important role in human pathophysiology. The effect of classical pathway activation is largely dependent on alternative pathway (AP) amplification, whereas the role of AP for the down-stream effect of mannan-induced lectin pathway (LP) activation is poorly understood...... that AP amplification is quantitatively responsible for the final effect of initial specific LP activation. TCC generation on the solid phase was distinctly but less inhibited by anti-fD. C2 bypass of the LP pathway could be demonstrated, and AP amplification was also essential during C2 bypass in LP...... as shown by complete inhibition of TCC generation in C2-deficient serum by anti-fD and anti-properdin antibodies. In conclusion, the down-stream effect of LP activation depends strongly on AP amplification in normal human serum and in the C2 bypass pathway....

  3. A novel quantitative model of cell cycle progression based on cyclin-dependent kinases activity and population balances.

    Science.gov (United States)

    Pisu, Massimo; Concas, Alessandro; Cao, Giacomo

    2015-04-01

    Cell cycle regulates proliferative cell capacity under normal or pathologic conditions, and in general it governs all in vivo/in vitro cell growth and proliferation processes. Mathematical simulation by means of reliable and predictive models represents an important tool to interpret experiment results, to facilitate the definition of the optimal operating conditions for in vitro cultivation, or to predict the effect of a specific drug in normal/pathologic mammalian cells. Along these lines, a novel model of cell cycle progression is proposed in this work. Specifically, it is based on a population balance (PB) approach that allows one to quantitatively describe cell cycle progression through the different phases experienced by each cell of the entire population during its own life. The transition between two consecutive cell cycle phases is simulated by taking advantage of the biochemical kinetic model developed by Gérard and Goldbeter (2009) which involves cyclin-dependent kinases (CDKs) whose regulation is achieved through a variety of mechanisms that include association with cyclins and protein inhibitors, phosphorylation-dephosphorylation, and cyclin synthesis or degradation. This biochemical model properly describes the entire cell cycle of mammalian cells by maintaining a sufficient level of detail useful to identify check point for transition and to estimate phase duration required by PB. Specific examples are discussed to illustrate the ability of the proposed model to simulate the effect of drugs for in vitro trials of interest in oncology, regenerative medicine and tissue engineering. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Quantitative Activities for Introductory Astronomy

    Science.gov (United States)

    Keohane, Jonathan W.; Bartlett, J. L.; Foy, J. P.

    2010-01-01

    We present a collection of short lecture-tutorial (or homework) activities, designed to be both quantitative and accessible to the introductory astronomy student. Each of these involves interpreting some real data, solving a problem using ratios and proportionalities, and making a conclusion based on the calculation. Selected titles include: "The Mass of Neptune” "The Temperature on Titan” "Rocks in the Early Solar System” "Comets Hitting Planets” "Ages of Meteorites” "How Flat are Saturn's Rings?” "Tides of the Sun and Moon on the Earth” "The Gliese 581 Solar System"; "Buckets in the Rain” "How Hot, Bright and Big is Betelgeuse?” "Bombs and the Sun” "What Forms Stars?” "Lifetimes of Cars and Stars” "The Mass of the Milky” "How Old is the Universe?” "Is The Universe Speeding up or Slowing Down?"

  5. Quantitative assessment of growth plate activity

    International Nuclear Information System (INIS)

    Harcke, H.T.; Macy, N.J.; Mandell, G.A.; MacEwen, G.D.

    1984-01-01

    In the immature skeleton the physis or growth plate is the area of bone least able to withstand external forces and is therefore prone to trauma. Such trauma often leads to premature closure of the plate and results in limb shortening and/or angular deformity (varus or valgus). Active localization of bone seeking tracers in the physis makes bone scintigraphy an excellent method for assessing growth plate physiology. To be most effective, however, physeal activity should be quantified so that serial evaluations are accurate and comparable. The authors have developed a quantitative method for assessing physeal activity and have applied it ot the hip and knee. Using computer acquired pinhole images of the abnormal and contralateral normal joints, ten regions of interest are placed at key locations around each joint and comparative ratios are generated to form a growth plate profile. The ratios compare segmental physeal activity to total growth plate activity on both ipsilateral and contralateral sides and to adjacent bone. In 25 patients, ages 2 to 15 years, with angular deformities of the legs secondary to trauma, Blount's disease, and Perthes disease, this technique is able to differentiate abnormal segmental physeal activity. This is important since plate closure does not usually occur uniformly across the physis. The technique may permit the use of scintigraphy in the prediction of early closure through the quantitative analysis of serial studies

  6. Quantitative interpretation of the magnetic susceptibility frequency dependence

    Science.gov (United States)

    Ustra, Andrea; Mendonça, Carlos A.; Leite, Aruã; Jovane, Luigi; Trindade, Ricardo I. F.

    2018-05-01

    Low-field mass-specific magnetic susceptibility (MS) measurements using multifrequency alternating fields are commonly used to evaluate concentration of ferrimagnetic particles in the transition of superparamagnetic (SP) to stable single domain (SSD). In classical palaeomagnetic analyses, this measurement serves as a preliminary assessment of rock samples providing rapid, non-destructive, economical and easy information of magnetic properties. The SP-SSD transition is relevant in environmental studies because it has been associated with several geological and biogeochemical processes affecting magnetic mineralogy. MS is a complex function of mineral-type and grain-size distribution, as well as measuring parameters such as external field magnitude and frequency. In this work, we propose a new technique to obtain quantitative information on grain-size variations of magnetic particles in the SP-SSD transition by inverting frequency-dependent susceptibility. We introduce a descriptive parameter named as `limiting frequency effect' that provides an accurate estimation of MS loss with frequency. Numerical simulations show the methodology capability in providing data fitting and model parameters in many practical situations. Real-data applications with magnetite nanoparticles and core samples from sediments of Poggio le Guaine section of Umbria-Marche Basin (Italy) provide additional information not clearly recognized when interpreting cruder MS data. Caution is needed when interpreting frequency dependence in terms of single relaxation processes, which are not universally applicable and depend upon the nature of magnetic mineral in the material. Nevertheless, the proposed technique is a promising tool for SP-SSD content analyses.

  7. Digital integrated protection system: Quantitative methods for dependability evaluation

    International Nuclear Information System (INIS)

    Krotoff, H.; Benski, C.

    1986-01-01

    The inclusion of programmed digital techniques in the SPIN system provides the used with the capability of performing sophisticated processing operations. However, it causes the quantitative evaluation of the overall failure probabilities to become somewhat more intricate by reason that: A single component may be involved in several functions; Self-tests may readily be incorporated for the purpose of monitoring the dependable operation of the equipment at all times. This paper describes the methods as implemented by MERLIN GERIN for the purpose of evaluating: The probabilities for the protective actions not to be initiated (dangerous failures); The probabilities for such protective actions to be initiated accidentally. Although the communication is focused on the programmed portion of the SPIN (UAIP) it will also deal with the evaluation performed within the scope of study works that do not exclusively cover the UAIPs

  8. Quantitative assessment of integrated phrenic nerve activity.

    Science.gov (United States)

    Nichols, Nicole L; Mitchell, Gordon S

    2016-06-01

    Integrated electrical activity in the phrenic nerve is commonly used to assess within-animal changes in phrenic motor output. Because of concerns regarding the consistency of nerve recordings, activity is most often expressed as a percent change from baseline values. However, absolute values of nerve activity are necessary to assess the impact of neural injury or disease on phrenic motor output. To date, no systematic evaluations of the repeatability/reliability have been made among animals when phrenic recordings are performed by an experienced investigator using standardized methods. We performed a meta-analysis of studies reporting integrated phrenic nerve activity in many rat groups by the same experienced investigator; comparisons were made during baseline and maximal chemoreceptor stimulation in 14 wild-type Harlan and 14 Taconic Sprague Dawley groups, and in 3 pre-symptomatic and 11 end-stage SOD1(G93A) Taconic rat groups (an ALS model). Meta-analysis results indicate: (1) consistent measurements of integrated phrenic activity in each sub-strain of wild-type rats; (2) with bilateral nerve recordings, left-to-right integrated phrenic activity ratios are ∼1.0; and (3) consistently reduced activity in end-stage SOD1(G93A) rats. Thus, with appropriate precautions, integrated phrenic nerve activity enables robust, quantitative comparisons among nerves or experimental groups, including differences caused by neuromuscular disease. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Quantitative assessment of target dependence of pion fluctuation in ...

    Indian Academy of Sciences (India)

    journal of. December 2012 physics pp. 1395–1405. Quantitative assessment ... The analysis reveals the erratic behaviour of the produced pions signifying ..... authors (Sitaram Pal) gratefully acknowledges the financial help from the University.

  10. Tip-Enhanced Raman Voltammetry: Coverage Dependence and Quantitative Modeling.

    Science.gov (United States)

    Mattei, Michael; Kang, Gyeongwon; Goubert, Guillaume; Chulhai, Dhabih V; Schatz, George C; Jensen, Lasse; Van Duyne, Richard P

    2017-01-11

    Electrochemical atomic force microscopy tip-enhanced Raman spectroscopy (EC-AFM-TERS) was employed for the first time to observe nanoscale spatial variations in the formal potential, E 0' , of a surface-bound redox couple. TERS cyclic voltammograms (TERS CVs) of single Nile Blue (NB) molecules were acquired at different locations spaced 5-10 nm apart on an indium tin oxide (ITO) electrode. Analysis of TERS CVs at different coverages was used to verify the observation of single-molecule electrochemistry. The resulting TERS CVs were fit to the Laviron model for surface-bound electroactive species to quantitatively extract the formal potential E 0' at each spatial location. Histograms of single-molecule E 0' at each coverage indicate that the electrochemical behavior of the cationic oxidized species is less sensitive to local environment than the neutral reduced species. This information is not accessible using purely electrochemical methods or ensemble spectroelectrochemical measurements. We anticipate that quantitative modeling and measurement of site-specific electrochemistry with EC-AFM-TERS will have a profound impact on our understanding of the role of nanoscale electrode heterogeneity in applications such as electrocatalysis, biological electron transfer, and energy production and storage.

  11. Identification and quantitation of signal molecule-dependent protein phosphorylation

    KAUST Repository

    Groen, Arnoud J.

    2013-09-03

    Phosphoproteomics is a fast-growing field that aims at characterizing phosphorylated proteins in a cell or a tissue at a given time. Phosphorylation of proteins is an important regulatory mechanism in many cellular processes. Gel-free phosphoproteome technique involving enrichment of phosphopeptide coupled with mass spectrometry has proven to be invaluable to detect and characterize phosphorylated proteins. In this chapter, a gel-free quantitative approach involving 15N metabolic labelling in combination with phosphopeptide enrichment by titanium dioxide (TiO2) and their identification by MS is described. This workflow can be used to gain insights into the role of signalling molecules such as cyclic nucleotides on regulatory networks through the identification and quantification of responsive phospho(proteins). © Springer Science+Business Media New York 2013.

  12. Quantitative CT: technique dependence of volume estimation on pulmonary nodules

    Science.gov (United States)

    Chen, Baiyu; Barnhart, Huiman; Richard, Samuel; Colsher, James; Amurao, Maxwell; Samei, Ehsan

    2012-03-01

    Current estimation of lung nodule size typically relies on uni- or bi-dimensional techniques. While new three-dimensional volume estimation techniques using MDCT have improved size estimation of nodules with irregular shapes, the effect of acquisition and reconstruction parameters on accuracy (bias) and precision (variance) of the new techniques has not been fully investigated. To characterize the volume estimation performance dependence on these parameters, an anthropomorphic chest phantom containing synthetic nodules was scanned and reconstructed with protocols across various acquisition and reconstruction parameters. Nodule volumes were estimated by a clinical lung analysis software package, LungVCAR. Precision and accuracy of the volume assessment were calculated across the nodules and compared between protocols via a generalized estimating equation analysis. Results showed that the precision and accuracy of nodule volume quantifications were dependent on slice thickness, with different dependences for different nodule characteristics. Other parameters including kVp, pitch, and reconstruction kernel had lower impact. Determining these technique dependences enables better volume quantification via protocol optimization and highlights the importance of consistent imaging parameters in sequential examinations.

  13. Quantitative and Dynamic Imaging of ATM Kinase Activity.

    Science.gov (United States)

    Nyati, Shyam; Young, Grant; Ross, Brian Dale; Rehemtulla, Alnawaz

    2017-01-01

    Ataxia telangiectasia mutated (ATM) is a serine/threonine kinase critical to the cellular DNA-damage response, including DNA double-strand breaks (DSBs). ATM activation results in the initiation of a complex cascade of events facilitating DNA damage repair, cell cycle checkpoint control, and survival. Traditionally, protein kinases have been analyzed in vitro using biochemical methods (kinase assays using purified proteins or immunological assays) requiring a large number of cells and cell lysis. Genetically encoded biosensors based on optical molecular imaging such as fluorescence or bioluminescence have been developed to enable interrogation of kinase activities in live cells with a high signal to background. We have genetically engineered a hybrid protein whose bioluminescent activity is dependent on the ATM-mediated phosphorylation of a substrate. The engineered protein consists of the split luciferase-based protein complementation pair with a CHK2 (a substrate for ATM kinase activity) target sequence and a phospho-serine/threonine-binding domain, FHA2, derived from yeast Rad53. Phosphorylation of the serine residue within the target sequence by ATM would lead to its interaction with the phospho-serine-binding domain, thereby preventing complementation of the split luciferase pair and loss of reporter activity. Bioluminescence imaging of reporter expressing cells in cultured plates or as mouse xenografts provides a quantitative surrogate for ATM kinase activity and therefore the cellular DNA damage response in a noninvasive, dynamic fashion.

  14. Quantitative Method of Measuring Metastatic Activity

    Science.gov (United States)

    Morrison, Dennis R. (Inventor)

    1999-01-01

    The metastatic potential of tumors can be evaluated by the quantitative detection of urokinase and DNA. The cell sample selected for examination is analyzed for the presence of high levels of urokinase and abnormal DNA using analytical flow cytometry and digital image analysis. Other factors such as membrane associated uroldnase, increased DNA synthesis rates and certain receptors can be used in the method for detection of potentially invasive tumors.

  15. Quantitative Structure-Activity Relationship Analysis of the ...

    African Journals Online (AJOL)

    Erah

    Quantitative Structure-Activity Relationship Analysis of the Anticonvulsant ... Two types of molecular descriptors, including the 2D autocorrelation ..... It is based on the simulation of natural .... clustering anticonvulsant, antidepressant, and.

  16. Passion and dependency in online shopping activities.

    Science.gov (United States)

    Wang, Chih-Chien; Yang, Hui-Wen

    2007-04-01

    This study examines the influence of harmonious passion (HP) and obsessive passion (OP) to online shopping dependency. The results show that both HP and OP might lead to online shopping dependency and online shoppers with OP are more dependent on online shopping activities. In addition, this study also found out that HP and OP could be denoted as a sequence of different intensities of passion, where HP might be a necessity of OP.

  17. The Arabidopsis thaliana Cyclic-Nucleotide-Dependent Response – a Quantitative Proteomic and Phosphoproteomic Analysis

    KAUST Repository

    Alqurashi, May M.

    2013-11-01

    Protein phosphorylation governs many regulatory pathways and an increasing number of kinases, proteins that transfer phosphate groups, are in turn activated by cyclic nucleotides. One of the cyclic nucleotides, cyclic adenosine monophosphate (cAMP), has been shown to be a second messenger in abiotic and biotic stress responses. However, little is known about the precise role of cAMP in plants and in the down-stream activation of kinases, and hence cAMP-dependent phosphorylation. To increase our understanding of the role of cAMP, proteomic and phosphoproteomic profiles of Arabidopsis thaliana suspension culture cells were analyzed before and after treatment of cells with two different concentrations of 8-Bromo-cAMP (1 µM and 100 nM) and over a time-course of one hour. A comparative quantitative analysis was undertaken using two- dimensional gel electrophoresis and the Delta 2D software (DECODON) followed by protein spot identification by tandem mass spectrometry combined with Mascot and Scaffold. Differentially expressed proteins and regulated phosphoproteins were categorized according to their biological function using bioinformatics tools. The results revealed that the treatment with 1 µM and 100 nM 8-Bromo-cAMP was sufficient to induce specific concentration- and time-dependent changes at the proteome and phosphoproteome levels. In particular, different phosphorylation patterns were observed overtime preferentially affecting proteins in a number of functional categories, notably phosphatases, proteins that remove phosphate groups. This suggests that cAMP both transiently activates and deactivates proteins through specific phosphorylation events and provides new insight into biological mechanisms and functions at the systems level.

  18. Joint analysis of binary and quantitative traits with data sharing and outcome-dependent sampling.

    Science.gov (United States)

    Zheng, Gang; Wu, Colin O; Kwak, Minjung; Jiang, Wenhua; Joo, Jungnam; Lima, Joao A C

    2012-04-01

    We study the analysis of a joint association between a genetic marker with both binary (case-control) and quantitative (continuous) traits, where the quantitative trait values are only available for the cases due to data sharing and outcome-dependent sampling. Data sharing becomes common in genetic association studies, and the outcome-dependent sampling is the consequence of data sharing, under which a phenotype of interest is not measured for some subgroup. The trend test (or Pearson's test) and F-test are often, respectively, used to analyze the binary and quantitative traits. Because of the outcome-dependent sampling, the usual F-test can be applied using the subgroup with the observed quantitative traits. We propose a modified F-test by also incorporating the genotype frequencies of the subgroup whose traits are not observed. Further, a combination of this modified F-test and Pearson's test is proposed by Fisher's combination of their P-values as a joint analysis. Because of the correlation of the two analyses, we propose to use a Gamma (scaled chi-squared) distribution to fit the asymptotic null distribution for the joint analysis. The proposed modified F-test and the joint analysis can also be applied to test single trait association (either binary or quantitative trait). Through simulations, we identify the situations under which the proposed tests are more powerful than the existing ones. Application to a real dataset of rheumatoid arthritis is presented. © 2012 Wiley Periodicals, Inc.

  19. Quantitative modeling of the ionospheric response to geomagnetic activity

    Directory of Open Access Journals (Sweden)

    T. J. Fuller-Rowell

    Full Text Available A physical model of the coupled thermosphere and ionosphere has been used to determine the accuracy of model predictions of the ionospheric response to geomagnetic activity, and assess our understanding of the physical processes. The physical model is driven by empirical descriptions of the high-latitude electric field and auroral precipitation, as measures of the strength of the magnetospheric sources of energy and momentum to the upper atmosphere. Both sources are keyed to the time-dependent TIROS/NOAA auroral power index. The output of the model is the departure of the ionospheric F region from the normal climatological mean. A 50-day interval towards the end of 1997 has been simulated with the model for two cases. The first simulation uses only the electric fields and auroral forcing from the empirical models, and the second has an additional source of random electric field variability. In both cases, output from the physical model is compared with F-region data from ionosonde stations. Quantitative model/data comparisons have been performed to move beyond the conventional "visual" scientific assessment, in order to determine the value of the predictions for operational use. For this study, the ionosphere at two ionosonde stations has been studied in depth, one each from the northern and southern mid-latitudes. The model clearly captures the seasonal dependence in the ionospheric response to geomagnetic activity at mid-latitude, reproducing the tendency for decreased ion density in the summer hemisphere and increased densities in winter. In contrast to the "visual" success of the model, the detailed quantitative comparisons, which are necessary for space weather applications, are less impressive. The accuracy, or value, of the model has been quantified by evaluating the daily standard deviation, the root-mean-square error, and the correlation coefficient between the data and model predictions. The modeled quiet-time variability, or standard

  20. Quantitative modeling of the ionospheric response to geomagnetic activity

    Directory of Open Access Journals (Sweden)

    T. J. Fuller-Rowell

    2000-07-01

    Full Text Available A physical model of the coupled thermosphere and ionosphere has been used to determine the accuracy of model predictions of the ionospheric response to geomagnetic activity, and assess our understanding of the physical processes. The physical model is driven by empirical descriptions of the high-latitude electric field and auroral precipitation, as measures of the strength of the magnetospheric sources of energy and momentum to the upper atmosphere. Both sources are keyed to the time-dependent TIROS/NOAA auroral power index. The output of the model is the departure of the ionospheric F region from the normal climatological mean. A 50-day interval towards the end of 1997 has been simulated with the model for two cases. The first simulation uses only the electric fields and auroral forcing from the empirical models, and the second has an additional source of random electric field variability. In both cases, output from the physical model is compared with F-region data from ionosonde stations. Quantitative model/data comparisons have been performed to move beyond the conventional "visual" scientific assessment, in order to determine the value of the predictions for operational use. For this study, the ionosphere at two ionosonde stations has been studied in depth, one each from the northern and southern mid-latitudes. The model clearly captures the seasonal dependence in the ionospheric response to geomagnetic activity at mid-latitude, reproducing the tendency for decreased ion density in the summer hemisphere and increased densities in winter. In contrast to the "visual" success of the model, the detailed quantitative comparisons, which are necessary for space weather applications, are less impressive. The accuracy, or value, of the model has been quantified by evaluating the daily standard deviation, the root-mean-square error, and the correlation coefficient between the data and model predictions. The modeled quiet-time variability, or standard

  1. Great red spot dependence on solar activity

    International Nuclear Information System (INIS)

    Schatten, K.H.

    1979-01-01

    A new inquiry has been made into the question of whether Jupiter's Great Red Spot shows a solar activity dependence. From 1892 to 1947 a clear correlation was present. A dearth of sightings in the seventeenth century, along with the Maunder Minimum, further supports the relation. An anticorrelation, however, from l948 to l967 removed support for such an effect. The old observations have reexamined and recent observations have also been studied. The author reexamines this difficult question and suggests a possible physical mechanism for a Sun-Jovian weather relation. Prinn and Lewis' conversion reaction of Phosphine gas to triclinic red phosphorous crystals is a reaction dependent upon solar radiation. It may explain the dependence found, as well as the striking appearance of the Great Red Spot in the UV

  2. Motor demand-dependent activation of ipsilateral motor cortex.

    Science.gov (United States)

    Buetefisch, Cathrin M; Revill, Kate Pirog; Shuster, Linda; Hines, Benjamin; Parsons, Michael

    2014-08-15

    The role of ipsilateral primary motor cortex (M1) in hand motor control during complex task performance remains controversial. Bilateral M1 activation is inconsistently observed in functional (f)MRI studies of unilateral hand performance. Two factors limit the interpretation of these data. As the motor tasks differ qualitatively in these studies, it is conceivable that M1 contributions differ with the demand on skillfulness. Second, most studies lack the verification of a strictly unilateral execution of the motor task during the acquisition of imaging data. Here, we use fMRI to determine whether ipsilateral M1 activity depends on the demand for precision in a pointing task where precision varied quantitatively while movement trajectories remained equal. Thirteen healthy participants used an MRI-compatible joystick to point to targets of four different sizes in a block design. A clustered acquisition technique allowed simultaneous fMRI/EMG data collection and confirmed that movements were strictly unilateral. Accuracy of performance increased with target size. Overall, the pointing task revealed activation in contralateral and ipsilateral M1, extending into contralateral somatosensory and parietal areas. Target size-dependent activation differences were found in ipsilateral M1 extending into the temporal/parietal junction, where activation increased with increasing demand on accuracy. The results suggest that ipsilateral M1 is active during the execution of a unilateral motor task and that its activity is modulated by the demand on precision. Copyright © 2014 the American Physiological Society.

  3. Light-dependent electrogenic activity of cyanobacteria.

    Directory of Open Access Journals (Sweden)

    John M Pisciotta

    2010-05-01

    Full Text Available Cyanobacteria account for 20-30% of Earth's primary photosynthetic productivity and convert solar energy into biomass-stored chemical energy at the rate of approximately 450 TW [1]. These single-cell microorganisms are resilient predecessors of all higher oxygenic phototrophs and can be found in self-sustaining, nitrogen-fixing communities the world over, from Antarctic glaciers to the Sahara desert [2].Here we show that diverse genera of cyanobacteria including biofilm-forming and pelagic strains have a conserved light-dependent electrogenic activity, i.e. the ability to transfer electrons to their surroundings in response to illumination. Naturally-growing biofilm-forming photosynthetic consortia also displayed light-dependent electrogenic activity, demonstrating that this phenomenon is not limited to individual cultures. Treatment with site-specific inhibitors revealed the electrons originate at the photosynthetic electron transfer chain (P-ETC. Moreover, electrogenic activity was observed upon illumination only with blue or red but not green light confirming that P-ETC is the source of electrons. The yield of electrons harvested by extracellular electron acceptor to photons available for photosynthesis ranged from 0.05% to 0.3%, although the efficiency of electron harvesting likely varies depending on terminal electron acceptor.The current study illustrates that cyanobacterial electrogenic activity is an important microbiological conduit of solar energy into the biosphere. The mechanism responsible for electrogenic activity in cyanobacteria appears to be fundamentally different from the one exploited in previously discovered electrogenic bacteria, such as Geobacter, where electrons are derived from oxidation of organic compounds and transported via a respiratory electron transfer chain (R-ETC [3], [4]. The electrogenic pathway of cyanobacteria might be exploited to develop light-sensitive devices or future technologies that convert solar

  4. Cdk1 activity acts as a quantitative platform for coordinating cell cycle progression with periodic transcription

    Science.gov (United States)

    Banyai, Gabor; Baïdi, Feriel; Coudreuse, Damien; Szilagyi, Zsolt

    2016-01-01

    Cell proliferation is regulated by cyclin-dependent kinases (Cdks) and requires the periodic expression of particular gene clusters in different cell cycle phases. However, the interplay between the networks that generate these transcriptional oscillations and the core cell cycle machinery remains largely unexplored. In this work, we use a synthetic regulable Cdk1 module to demonstrate that periodic expression is governed by quantitative changes in Cdk1 activity, with different clusters directly responding to specific activity levels. We further establish that cell cycle events neither participate in nor interfere with the Cdk1-driven transcriptional program, provided that cells are exposed to the appropriate Cdk1 activities. These findings contrast with current models that propose self-sustained and Cdk1-independent transcriptional oscillations. Our work therefore supports a model in which Cdk1 activity serves as a quantitative platform for coordinating cell cycle transitions with the expression of critical genes to bring about proper cell cycle progression. PMID:27045731

  5. Quantitative genetic activity graphical profiles for use in chemical evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Waters, M.D. [Environmental Protection Agency, Washington, DC (United States); Stack, H.F.; Garrett, N.E.; Jackson, M.A. [Environmental Health Research and Testing, Inc., Research Triangle Park, NC (United States)

    1990-12-31

    A graphic approach, terms a Genetic Activity Profile (GAP), was developed to display a matrix of data on the genetic and related effects of selected chemical agents. The profiles provide a visual overview of the quantitative (doses) and qualitative (test results) data for each chemical. Either the lowest effective dose or highest ineffective dose is recorded for each agent and bioassay. Up to 200 different test systems are represented across the GAP. Bioassay systems are organized according to the phylogeny of the test organisms and the end points of genetic activity. The methodology for producing and evaluating genetic activity profile was developed in collaboration with the International Agency for Research on Cancer (IARC). Data on individual chemicals were compiles by IARC and by the US Environmental Protection Agency (EPA). Data are available on 343 compounds selected from volumes 1-53 of the IARC Monographs and on 115 compounds identified as Superfund Priority Substances. Software to display the GAPs on an IBM-compatible personal computer is available from the authors. Structurally similar compounds frequently display qualitatively and quantitatively similar profiles of genetic activity. Through examination of the patterns of GAPs of pairs and groups of chemicals, it is possible to make more informed decisions regarding the selection of test batteries to be used in evaluation of chemical analogs. GAPs provided useful data for development of weight-of-evidence hazard ranking schemes. Also, some knowledge of the potential genetic activity of complex environmental mixtures may be gained from an assessment of the genetic activity profiles of component chemicals. The fundamental techniques and computer programs devised for the GAP database may be used to develop similar databases in other disciplines. 36 refs., 2 figs.

  6. Review of Department of Defense Education Activity (DODEA) Schools. Volume II: Quantitative Analysis of Educational Quality

    National Research Council Canada - National Science Library

    Anderson, Lowell

    2000-01-01

    This volume compiles, and presents in integrated form, IDA's quantitative analysis of educational quality provided by DoD's dependent schools, It covers the quantitative aspects of volume I in greater...

  7. Quantitative Structure ‒ Antiprotozoal Activity Relationships of Sesquiterpene Lactones

    Directory of Open Access Journals (Sweden)

    Reto Brun

    2009-06-01

    Full Text Available Prompted by results of our previous studies where we found high activity of some sesquiterpene lactones (STLs against Trypanosoma brucei rhodesiense (which causes East African sleeping sickness, we have now conducted a structure-(in-vitro-activity study on a set of 40 STLs against T. brucei rhodesiense, T. cruzi, Leishmania donovani and Plasmodium falciparum. Furthermore, cytotoxic activity against L6 rat skeletal myoblast cells was assessed. Some of the compounds possess high activity, especially against T. brucei (e.g. helenalin and some of its esters with IC50-values of 0.05-0.1 µM, which is about 10 times lower than their cytotoxic activity. It was found that all investigated antiprotozoal activities are significantly correlated with cytotoxicity and the major determinants for activity are a,b-unsaturated structural elements, also known to be essential for other biological activities of STLs. It was observed, however, that certain compounds are considerably more toxic against protozoa than against mammalian cells while others are more cytotoxic than active against the protozoa. A comparative QSAR analysis was therefore undertaken, in order to discern the antiparasitic activity of STLs against T. brucei and cytotoxicity. Both activities were found to depend to a large extent on the same structural elements and molecular properties. The observed variance in the biological data can be explained in terms of subtle variations in the relative influences of various molecular descriptors.

  8. Quantitative analysis of the Ca2+ -dependent regulation of delayed rectifier K+ current IKs in rabbit ventricular myocytes.

    Science.gov (United States)

    Bartos, Daniel C; Morotti, Stefano; Ginsburg, Kenneth S; Grandi, Eleonora; Bers, Donald M

    2017-04-01

    [Ca 2+ ] i enhanced rabbit ventricular slowly activating delayed rectifier K + current (I Ks ) by negatively shifting the voltage dependence of activation and slowing deactivation, similar to perfusion of isoproterenol. Rabbit ventricular rapidly activating delayed rectifier K + current (I Kr ) amplitude and voltage dependence were unaffected by high [Ca 2+ ] i . When measuring or simulating I Ks during an action potential, I Ks was not different during a physiological Ca 2+ transient or when [Ca 2+ ] i was buffered to 500 nm. The slowly activating delayed rectifier K + current (I Ks ) contributes to repolarization of the cardiac action potential (AP). Intracellular Ca 2+ ([Ca 2+ ] i ) and β-adrenergic receptor (β-AR) stimulation modulate I Ks amplitude and kinetics, but details of these important I Ks regulators and their interaction are limited. We assessed the [Ca 2+ ] i dependence of I Ks in steady-state conditions and with dynamically changing membrane potential and [Ca 2+ ] i during an AP. I Ks was recorded from freshly isolated rabbit ventricular myocytes using whole-cell patch clamp. With intracellular pipette solutions that controlled free [Ca 2+ ] i , we found that raising [Ca 2+ ] i from 100 to 600 nm produced similar increases in I Ks as did β-AR activation, and the effects appeared additive. Both β-AR activation and high [Ca 2+ ] i increased maximally activated tail I Ks , negatively shifted the voltage dependence of activation, and slowed deactivation kinetics. These data informed changes in our well-established mathematical model of the rabbit myocyte. In both AP-clamp experiments and simulations, I Ks recorded during a normal physiological Ca 2+ transient was similar to I Ks measured with [Ca 2+ ] i clamped at 500-600 nm. Thus, our study provides novel quantitative data as to how physiological [Ca 2+ ] i regulates I Ks amplitude and kinetics during the normal rabbit AP. Our results suggest that micromolar [Ca 2+ ] i , in the submembrane or

  9. Characterization of ubiquitination dependent dynamics in growth factor receptor signaling by quantitative proteomics

    DEFF Research Database (Denmark)

    Akimov, Vyacheslav; Rigbolt, Kristoffer T G; Nielsen, Mogens M

    2011-01-01

    Protein ubiquitination is a dynamic reversible post-translational modification that plays a key role in the regulation of numerous cellular processes including signal transduction, endocytosis, cell cycle control, DNA repair and gene transcription. The conjugation of the small protein ubiquitin...... investigating ubiquitination on a proteomic scale, mainly due to the inherited complexity and heterogeneity of ubiquitination. We describe here a quantitative proteomics strategy based on the specificity of ubiquitin binding domains (UBDs) and Stable Isotope Labeling by Amino acids in Cell culture (SILAC...... as ubiquitination-dependent events in signaling pathways. In addition to a detailed seven time-point profile of EGFR ubiquitination over 30 minutes of ligand stimulation, our data determined prominent involvement of Lysine-63 ubiquitin branching in EGF signaling. Furthermore, we found two centrosomal proteins, PCM1...

  10. Activated sludge characterization through microscopy: A review on quantitative image analysis and chemometric techniques

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Daniela P. [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Amaral, A. Luís [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Instituto Politécnico de Coimbra, ISEC, DEQB, Rua Pedro Nunes, Quinta da Nora, 3030-199 Coimbra (Portugal); Ferreira, Eugénio C., E-mail: ecferreira@deb.uminho.pt [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

    2013-11-13

    Graphical abstract: -- Highlights: •Quantitative image analysis shows potential to monitor activated sludge systems. •Staining techniques increase the potential for detection of operational problems. •Chemometrics combined with quantitative image analysis is valuable for process monitoring. -- Abstract: In wastewater treatment processes, and particularly in activated sludge systems, efficiency is quite dependent on the operating conditions, and a number of problems may arise due to sludge structure and proliferation of specific microorganisms. In fact, bacterial communities and protozoa identification by microscopy inspection is already routinely employed in a considerable number of cases. Furthermore, quantitative image analysis techniques have been increasingly used throughout the years for the assessment of aggregates and filamentous bacteria properties. These procedures are able to provide an ever growing amount of data for wastewater treatment processes in which chemometric techniques can be a valuable tool. However, the determination of microbial communities’ properties remains a current challenge in spite of the great diversity of microscopy techniques applied. In this review, activated sludge characterization is discussed highlighting the aggregates structure and filamentous bacteria determination by image analysis on bright-field, phase-contrast, and fluorescence microscopy. An in-depth analysis is performed to summarize the many new findings that have been obtained, and future developments for these biological processes are further discussed.

  11. A Quantitative, Time-Dependent Model of Oxygen Isotopes in the Solar Nebula: Step one

    Science.gov (United States)

    Nuth, J. A.; Paquette, J. A.; Farquhar, A.; Johnson, N. M.

    2011-01-01

    The remarkable discovery that oxygen isotopes in primitive meteorites were fractionated along a line of slope I rather than along the typical slope 0,52 terrestrial fractionation line occurred almost 40 years ago, However, a satisfactory, quantitative explanation for this observation has yet to be found, though many different explanations have been proposed, The first of these explanations proposed that the observed line represented the final product produced by mixing molecular cloud dust with a nucleosynthetic component, rich in O-16, possibly resulting from a nearby supernova explosion, Donald Clayton suggested that Galactic Chemical Evolution would gradually change the oxygen isotopic composition of the interstellar grain population by steadily producing O-16 in supernovae, then producing the heavier isotopes as secondary products in lower mass stars, Thiemens and collaborators proposed a chemical mechanism that relied on the availability of additional active rotational and vibrational states in otherwise-symmetric molecules, such as CO2, O3 or SiO2, containing two different oxygen isotopes and a second, photochemical process that suggested that differential photochemical dissociation processes could fractionate oxygen , This second line of research has been pursued by several groups, though none of the current models is quantitative,

  12. Quantitative proteomic characterization of redox-dependent post-translational modifications on protein cysteines

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Jicheng; Gaffrey, Matthew J.; Qian, Wei-Jun

    2017-01-01

    Protein cysteine thiols play a crucial role in redox signaling, regulation of enzymatic activity and protein function, and maintaining redox homeostasis in living systems. The unique chemical reactivity of thiol groups makes cysteine susceptible to oxidative modifications by reactive oxygen and nitrogen species to form a broad array of reversible and irreversible protein post-translational modifications (PTMs). The reversible modifications in particular are one of the major components of redox signaling and are involved in regulation of various cellular processes under physiological and pathological conditions. The biological significance of these redox PTMs in health and diseases has been increasingly recognized. Herein, we review the recent advances of quantitative proteomic approaches for investigating redox PTMs in complex biological systems, including the general considerations of sample processing, various chemical or affinity enrichment strategies, and quantitative approaches. We also highlight a number of redox proteomic approaches that enable effective profiling of redox PTMs for addressing specific biological questions. Although some technological limitations remain, redox proteomics is paving the way towards a better understanding of redox signaling and regulation in human health and diseases.

  13. Designing a Quantitative Structure-Activity Relationship for the ...

    Science.gov (United States)

    Toxicokinetic models serve a vital role in risk assessment by bridging the gap between chemical exposure and potentially toxic endpoints. While intrinsic metabolic clearance rates have a strong impact on toxicokinetics, limited data is available for environmentally relevant chemicals including nearly 8000 chemicals tested for in vitro bioactivity in the Tox21 program. To address this gap, a quantitative structure-activity relationship (QSAR) for intrinsic metabolic clearance rate was developed to offer reliable in silico predictions for a diverse array of chemicals. Models were constructed with curated in vitro assay data for both pharmaceutical-like chemicals (ChEMBL database) and environmentally relevant chemicals (ToxCast screening) from human liver microsomes (2176 from ChEMBL) and human hepatocytes (757 from ChEMBL and 332 from ToxCast). Due to variability in the experimental data, a binned approach was utilized to classify metabolic rates. Machine learning algorithms, such as random forest and k-nearest neighbor, were coupled with open source molecular descriptors and fingerprints to provide reasonable estimates of intrinsic metabolic clearance rates. Applicability domains defined the optimal chemical space for predictions, which covered environmental chemicals well. A reduced set of informative descriptors (including relative charge and lipophilicity) and a mixed training set of pharmaceuticals and environmentally relevant chemicals provided the best intr

  14. Halden project activities on software dependability

    International Nuclear Information System (INIS)

    Dahll, G.; Sivertsen.

    1994-01-01

    Since 1977, the OECD Halden Reactor Project has been working in the field of software dependability. Special emphasis has been put on the use of software in safety critical systems. All phases in software development, from specification through software development, verification, and validation have been covered and are discussed in this article

  15. Magnetic field dependence of vortex activation energy

    Indian Academy of Sciences (India)

    ... the resistance as a function of temperature and magnetic field in clean polycrystalline samples of NbSe2, MgB2 and Bi2Sr2Ca2Cu3O10 (BSCCO) superconductors. Thermally activated flux flow behaviour is seen in all the three systems and clearly identified in bulk MgB2. While the activation energy at low fields for MgB2 ...

  16. Dual gene activation and knockout screen reveals directional dependencies in genetic networks. | Office of Cancer Genomics

    Science.gov (United States)

    Understanding the direction of information flow is essential for characterizing how genetic networks affect phenotypes. However, methods to find genetic interactions largely fail to reveal directional dependencies. We combine two orthogonal Cas9 proteins from Streptococcus pyogenes and Staphylococcus aureus to carry out a dual screen in which one gene is activated while a second gene is deleted in the same cell. We analyze the quantitative effects of activation and knockout to calculate genetic interaction and directionality scores for each gene pair.

  17. Precursor Dependent Structural Properties and Antibacterial Activity ...

    Indian Academy of Sciences (India)

    71

    10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30 ... absorption spectroscopy, Scanning electron microscopy (SEM) and Zeta ... The antibacterial activity of the synthesized CuO were studied against human .... Sample d : Copper oxide synthesized with cupric sulphate as precursor ...... Chem.4 86.

  18. Nicotine Dependence, Physical Activity, and Sedentary Behavior among Adult Smokers.

    Science.gov (United States)

    Loprinzi, Paul D; Walker, Jerome F

    2015-03-01

    Research has previously demonstrated an inverse association between smoking status and physical activity; however, few studies have examined the association between nicotine dependence and physical activity or sedentary behavior. This study examined the association between nicotine dependence and accelerometer-determined physical activity and sedentary behavior. Data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) were used. A total of 851 adult (≥20 years) smokers wore an accelerometer for ≥4 days and completed the Fagerstrom Test for Nicotine Dependence scale. Regression models were used to examine the association between nicotine dependence and physical activity/sedentary behavior. After adjusting for age, gender, race-ethnicity, poverty level, hypertension, emphysema, bronchitis, body mass index (BMI), cotinine, and accelerometer wear time, smokers 50 + years of age with greater nicotine dependence engaged in more sedentary behavior (β = 11.4, P = 0.02) and less light-intensity physical activity (β = -9.6, P = 0.03) and moderate-to-vigorous physical activity (MVPA; β = -0.14, P = 0.003) than their less nicotine dependent counterparts. Older adults who are more nicotine dependent engage in less physical activity (both MVPA and light-intensity) and more sedentary behavior than their less nicotine dependent counterparts.

  19. Voltage Dependence of a Neuromodulator-Activated Ionic Current123

    Science.gov (United States)

    2016-01-01

    Abstract The neuromodulatory inward current (IMI) generated by crab Cancer borealis stomatogastric ganglion neurons is an inward current whose voltage dependence has been shown to be crucial in the activation of oscillatory activity of the pyloric network of this system. It has been previously shown that IMI loses its voltage dependence in conditions of low extracellular calcium, but that this effect appears to be regulated by intracellular calmodulin. Voltage dependence is only rarely regulated by intracellular signaling mechanisms. Here we address the hypothesis that the voltage dependence of IMI is mediated by intracellular signaling pathways activated by extracellular calcium. We demonstrate that calmodulin inhibitors and a ryanodine antagonist can reduce IMI voltage dependence in normal Ca2+, but that, in conditions of low Ca2+, calmodulin activators do not restore IMI voltage dependence. Further, we show evidence that CaMKII alters IMI voltage dependence. These results suggest that calmodulin is necessary but not sufficient for IMI voltage dependence. We therefore hypothesize that the Ca2+/calmodulin requirement for IMI voltage dependence is due to an active sensing of extracellular calcium by a GPCR family calcium-sensing receptor (CaSR) and that the reduction in IMI voltage dependence by a calmodulin inhibitor is due to CaSR endocytosis. Supporting this, preincubation with an endocytosis inhibitor prevented W7 (N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride)-induced loss of IMI voltage dependence, and a CaSR antagonist reduced IMI voltage dependence. Additionally, myosin light chain kinase, which is known to act downstream of the CaSR, seems to play a role in regulating IMI voltage dependence. Finally, a Gβγ-subunit inhibitor also affects IMI voltage dependence, in support of the hypothesis that this process is regulated by a G-protein-coupled CaSR. PMID:27257619

  20. THE COMPARATIVE ANALYSIS OF THE ACTIVITY ASSAY METHODS FOR MG2+-DEPENDENT NA+/K+-ACTIVATED ATPASE IN ERYTHROCYTE MEMBRANES

    Directory of Open Access Journals (Sweden)

    Polina Anatolevna Petrova

    2017-12-01

    Full Text Available This review considers the methodological reasons for the wide range of results for the red blood cells Mg2+-dependent Na+/K+-ATPase activity described by different authors. We assert that the differences in the Na+/K+-ATPase activity obtained by the researchers are due to the methodological peculiarities associated with methods of obtaining and measurement of the enzyme activity, such as red blood cells separation and storage (centrifugation, concentration and composition of the lysing solution, time and temperature of hemolysis and freezing, as well as the peculiarities of methods for the quantitative determination of protein and inorganic phosphorus. On the basis of the literature data analysis we recommend that for the most accurate determination of the Na+/K+-ATPase activity it is better to use the chelator in the lysing buffer solution and Fiske-Subbarow and Lowry methods for the determination of inorganic phosphorus and quantitative protein content, respectively.

  1. Nicotine dependence, physical activity, and sedentary behavior among adult smokers

    OpenAIRE

    Paul D Loprinzi; Jerome F Walker

    2015-01-01

    Background: Research has previously demonstrated an inverse association between smoking status and physical activity; however, few studies have examined the association between nicotine dependence and physical activity or sedentary behavior. Aim: This study examined the association between nicotine dependence and accelerometer-determined physical activity and sedentary behavior. Materials and Methods: Data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) were used....

  2. Temperature-dependent solute segregation in dilute Cu-Be under self-ion irradiation: a quantitative revision

    International Nuclear Information System (INIS)

    Koch, R.

    1993-01-01

    A reinvestigation of experimental data on solute precipitation behaviour in a Cu-1.35 at.%Be alloy subjected to Cu-ion irradiation has been carried out with regard to its strong dependence on the irradiation temperature in the range 400-700 K. A rate equation formalism presented in 1985 to describe the defect kinetics via mixed dumbbell formation and diffusion has been modified to take account of the redissolution of precipitated solutes into the matrix due to thermal vacancies. On the basis of the derived model this effect is shown to cause the observed reduction and disappearance of precipitation at high temperatures. Dumbbell dissociation and defect recombination with thermal vacancies become effective at still higher temperatures. The low-temperature decrease in precipitation is explained quantitatively by a marked change from the sink to the recombination case for point-defect annihilation. Moreover the whole temperature regime of precipitation is shown to shift to higher temperatures with increasing displacement rate. Both values of the activation enthalpies for migration and dissociation of the interstitial complex are given by analytical expressions and correspond to earlier estimates. (Author)

  3. The Quantitative Basis of the Arabidopsis Innate Immune System to Endemic Pathogens Depends on Pathogen Genetics.

    Directory of Open Access Journals (Sweden)

    Jason A Corwin

    2016-02-01

    Full Text Available The most established model of the eukaryotic innate immune system is derived from examples of large effect monogenic quantitative resistance to pathogens. However, many host-pathogen interactions involve many genes of small to medium effect and exhibit quantitative resistance. We used the Arabidopsis-Botrytis pathosystem to explore the quantitative genetic architecture underlying host innate immune system in a population of Arabidopsis thaliana. By infecting a diverse panel of Arabidopsis accessions with four phenotypically and genotypically distinct isolates of the fungal necrotroph B. cinerea, we identified a total of 2,982 genes associated with quantitative resistance using lesion area and 3,354 genes associated with camalexin production as measures of the interaction. Most genes were associated with resistance to a specific Botrytis isolate, which demonstrates the influence of pathogen genetic variation in analyzing host quantitative resistance. While known resistance genes, such as receptor-like kinases (RLKs and nucleotide-binding site leucine-rich repeat proteins (NLRs, were found to be enriched among associated genes, they only account for a small fraction of the total genes associated with quantitative resistance. Using publically available co-expression data, we condensed the quantitative resistance associated genes into co-expressed gene networks. GO analysis of these networks implicated several biological processes commonly connected to disease resistance, including defense hormone signaling and ROS production, as well as novel processes, such as leaf development. Validation of single gene T-DNA knockouts in a Col-0 background demonstrate a high success rate (60% when accounting for differences in environmental and Botrytis genetic variation. This study shows that the genetic architecture underlying host innate immune system is extremely complex and is likely able to sense and respond to differential virulence among pathogen

  4. Frictional coefficient depending on active friction radius with BPV ...

    African Journals Online (AJOL)

    Frictional coefficient depending on active friction radius with BPV and BTV in automobile disc braking system. ... International Journal of Engineering, Science and Technology. Journal Home · ABOUT ... AJOL African Journals Online. HOW TO ...

  5. Quantitative analysis of HGF and EGF-dependent phosphotyrosine signaling networks

    DEFF Research Database (Denmark)

    Hammond, Dean E; Hyde, Russell; Kratchmarova, Irina

    2010-01-01

    549 lung adenocarcinoma cells with EGF or HGF. In total, we obtained quantitative information for 274 proteins, which respond to either or both stimuli by >1.5 fold changes in enrichment, following immuno-precipitation with antiphosphotyrosine antibodies. The data reveal a high degree of overlap...

  6. Quantitative Phase-Field Approach for Simulating Grain Growth in Anisotropic Systems with Arbitrary Inclination and Misorientation Dependence

    International Nuclear Information System (INIS)

    Moelans, N.; Blanpain, B.; Wollants, P.

    2008-01-01

    A phase-field approach for quantitative simulations of grain growth in anisotropic systems is introduced, together with a new methodology to derive appropriate model parameters that reproduce given misorientation and inclination dependent grain boundary energy and mobility in the simulations. The proposed model formulation and parameter choice guarantee a constant diffuse interface width and consequently give high controllability of the accuracy in grain growth simulations

  7. Quantitative structure-activity relationship (QSAR) for insecticides: development of predictive in vivo insecticide activity models.

    Science.gov (United States)

    Naik, P K; Singh, T; Singh, H

    2009-07-01

    Quantitative structure-activity relationship (QSAR) analyses were performed independently on data sets belonging to two groups of insecticides, namely the organophosphates and carbamates. Several types of descriptors including topological, spatial, thermodynamic, information content, lead likeness and E-state indices were used to derive quantitative relationships between insecticide activities and structural properties of chemicals. A systematic search approach based on missing value, zero value, simple correlation and multi-collinearity tests as well as the use of a genetic algorithm allowed the optimal selection of the descriptors used to generate the models. The QSAR models developed for both organophosphate and carbamate groups revealed good predictability with r(2) values of 0.949 and 0.838 as well as [image omitted] values of 0.890 and 0.765, respectively. In addition, a linear correlation was observed between the predicted and experimental LD(50) values for the test set data with r(2) of 0.871 and 0.788 for both the organophosphate and carbamate groups, indicating that the prediction accuracy of the QSAR models was acceptable. The models were also tested successfully from external validation criteria. QSAR models developed in this study should help further design of novel potent insecticides.

  8. Quantitative Index and Abnormal Alarm Strategy Using Sensor-Dependent Vibration Data for Blade Crack Identification in Centrifugal Booster Fans.

    Science.gov (United States)

    Chen, Jinglong; Sun, Hailiang; Wang, Shuai; He, Zhengjia

    2016-05-09

    Centrifugal booster fans are important equipment used to recover blast furnace gas (BFG) for generating electricity, but blade crack faults (BCFs) in centrifugal booster fans can lead to unscheduled breakdowns and potentially serious accidents, so in this work quantitative fault identification and an abnormal alarm strategy based on acquired historical sensor-dependent vibration data is proposed for implementing condition-based maintenance for this type of equipment. Firstly, three group dependent sensors are installed to acquire running condition data. Then a discrete spectrum interpolation method and short time Fourier transform (STFT) are applied to preliminarily identify the running data in the sensor-dependent vibration data. As a result a quantitative identification and abnormal alarm strategy based on compound indexes including the largest Lyapunov exponent and relative energy ratio at the second harmonic frequency component is proposed. Then for validation the proposed blade crack quantitative identification and abnormality alarm strategy is applied to analyze acquired experimental data for centrifugal booster fans and it has successfully identified incipient blade crack faults. In addition, the related mathematical modelling work is also introduced to investigate the effects of mistuning and cracks on the vibration features of centrifugal impellers and to explore effective techniques for crack detection.

  9. Quantitative Index and Abnormal Alarm Strategy Using Sensor-Dependent Vibration Data for Blade Crack Identification in Centrifugal Booster Fans

    Directory of Open Access Journals (Sweden)

    Jinglong Chen

    2016-05-01

    Full Text Available Centrifugal booster fans are important equipment used to recover blast furnace gas (BFG for generating electricity, but blade crack faults (BCFs in centrifugal booster fans can lead to unscheduled breakdowns and potentially serious accidents, so in this work quantitative fault identification and an abnormal alarm strategy based on acquired historical sensor-dependent vibration data is proposed for implementing condition-based maintenance for this type of equipment. Firstly, three group dependent sensors are installed to acquire running condition data. Then a discrete spectrum interpolation method and short time Fourier transform (STFT are applied to preliminarily identify the running data in the sensor-dependent vibration data. As a result a quantitative identification and abnormal alarm strategy based on compound indexes including the largest Lyapunov exponent and relative energy ratio at the second harmonic frequency component is proposed. Then for validation the proposed blade crack quantitative identification and abnormality alarm strategy is applied to analyze acquired experimental data for centrifugal booster fans and it has successfully identified incipient blade crack faults. In addition, the related mathematical modelling work is also introduced to investigate the effects of mistuning and cracks on the vibration features of centrifugal impellers and to explore effective techniques for crack detection.

  10. Cerebral Metabolic Rate of Oxygen (CMRO2 ) Mapping by Combining Quantitative Susceptibility Mapping (QSM) and Quantitative Blood Oxygenation Level-Dependent Imaging (qBOLD).

    Science.gov (United States)

    Cho, Junghun; Kee, Youngwook; Spincemaille, Pascal; Nguyen, Thanh D; Zhang, Jingwei; Gupta, Ajay; Zhang, Shun; Wang, Yi

    2018-03-07

    To map the cerebral metabolic rate of oxygen (CMRO 2 ) by estimating the oxygen extraction fraction (OEF) from gradient echo imaging (GRE) using phase and magnitude of the GRE data. 3D multi-echo gradient echo imaging and perfusion imaging with arterial spin labeling were performed in 11 healthy subjects. CMRO 2 and OEF maps were reconstructed by joint quantitative susceptibility mapping (QSM) to process GRE phases and quantitative blood oxygen level-dependent (qBOLD) modeling to process GRE magnitudes. Comparisons with QSM and qBOLD alone were performed using ROI analysis, paired t-tests, and Bland-Altman plot. The average CMRO 2 value in cortical gray matter across subjects were 140.4 ± 14.9, 134.1 ± 12.5, and 184.6 ± 17.9 μmol/100 g/min, with corresponding OEFs of 30.9 ± 3.4%, 30.0 ± 1.8%, and 40.9 ± 2.4% for methods based on QSM, qBOLD, and QSM+qBOLD, respectively. QSM+qBOLD provided the highest CMRO 2 contrast between gray and white matter, more uniform OEF than QSM, and less noisy OEF than qBOLD. Quantitative CMRO 2 mapping that fits the entire complex GRE data is feasible by combining QSM analysis of phase and qBOLD analysis of magnitude. © 2018 International Society for Magnetic Resonance in Medicine.

  11. Quantitative genetic methods depending on the nature of the phenotypic trait.

    Science.gov (United States)

    de Villemereuil, Pierre

    2018-01-24

    A consequence of the assumptions of the infinitesimal model, one of the most important theoretical foundations of quantitative genetics, is that phenotypic traits are predicted to be most often normally distributed (so-called Gaussian traits). But phenotypic traits, especially those interesting for evolutionary biology, might be shaped according to very diverse distributions. Here, I show how quantitative genetics tools have been extended to account for a wider diversity of phenotypic traits using first the threshold model and then more recently using generalized linear mixed models. I explore the assumptions behind these models and how they can be used to study the genetics of non-Gaussian complex traits. I also comment on three recent methodological advances in quantitative genetics that widen our ability to study new kinds of traits: the use of "modular" hierarchical modeling (e.g., to study survival in the context of capture-recapture approaches for wild populations); the use of aster models to study a set of traits with conditional relationships (e.g., life-history traits); and, finally, the study of high-dimensional traits, such as gene expression. © 2018 New York Academy of Sciences.

  12. Diurnal variation in glycogen phosphorylase activity in rat liver. A quantitative histochemical study

    NARCIS (Netherlands)

    Frederiks, W. M.; Marx, F.; Bosch, K. S.

    1987-01-01

    The diurnal variations of the glycogen content and of glycogen phosphorylase activity in periportal and pericentral areas of rat liver parenchyma have been analyzed in periodic acid Schiff (PAS)-stained cryostat sections using quantitative microdensitometry. Glycogen content and phosphorylase

  13. A Quantitative Structure-Activity Relationships (QSAR Study of Piperine Based Derivatives with Leishmanicidal Activity

    Directory of Open Access Journals (Sweden)

    Edilson Beserra Alencar Filho

    2017-04-01

    Full Text Available Leishmaniasis is a parasitic disease which represents a serious public health problem in developing countries. It is considered a neglected tropical disease, for which there is little initiative in the search for therapeutic alternatives by pharmaceutical industry. Natural products remain a great source of inspiration for obtaining bioactive molecules. In 2010, Singh and co-workers published the synthesis and in vitro biological activity of piperoyl-aminoacid conjugates, as well as of piperine, against cellular cultures of Leishmania donovani. The piperine is an alkaloid isolated from Piper nigrum that has many activities described in the literature. In this work, we present a Quantitative Structure-Activity Study of piperine derivatives tested by Singh and co-workers, aiming to highlight important molecular features for leishmanicidal activity, obtaining a mathematical model to predict the activity of new analogs. Compounds were submitted to a geometry optimization computational procedure at semiempirical level of quantum theory. Molecular descriptors for the set of compounds were calculated by E-Dragon online plataform, followed by a variable selection procedure using Ordered Predictors Selection algorithm. Validation parameters obtained showed that a good QSAR model, based on multiple linear regression, was obtained (R2 = 0.85; Q2 = 0.69, and the following conclusions regarding the structure-activity relationship were elucidated: Compounds with electronegative atoms on different substituent groups of analogs, absence of unsaturation on lateral chain, presence of ester instead of carboxyl, and large volumes (due the presence of additional aromatic rings trends to increase the activity against promastigote forms of leishmania. DOI: http://dx.doi.org/10.17807/orbital.v9i1.893

  14. Quantitative diffusion characteristics of the human brain depend on MRI sequence parameters

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M.; Blumhardt, L.D. [University of Nottingham, Department of Neurology, Royal Preston Hospital, Preston (United Kingdom); Morgan, P.S. [Division of Academic Radiology, Queens Medical Centre, Nottingham (United Kingdom)

    2002-07-01

    Quantitative diffusion-weighted MRI has been applied to the study of neurological diseases, including multiple sclerosis, where the molecular self-diffusion coefficient D has been measured in both lesions and normal-appearing white matter. Histograms of D have been used as a novel measure of the ''lesion load'', with potential applications that include the monitoring of efficacy in new treatment trials. However different ways of measuring D may affect its value, making comparison between different centres and research groups impossible. We aimed to assess the effect, if any, of using two different MRI sequences on the value of D. We studied 13 healthy volunteers, using two different quantitative diffusion sequences (including different b{sub max} values and gradient applications). Maps of D were analysed using both regions of interest (ROI) in white matter and ''whole brain'' histograms, and compared between the two sequences. In addition, we studied three standardised test liquids (with known values of D) using both sequences. Histograms from the two sequences had different distributions, with a greater spread and higher peak position from the sequence with lower b{sub max}. This greater spread of D was also evident in the white matter and test liquid ROI. ''Limits of agreement'' analysis demonstrated that the differences could be clinically relevant, despite significant correlations between the sequences obtained using simple rank methods. We conclude that different quantitative diffusion sequences are unlikely to produce directly comparable values of D, particularly if different b{sub max} values are used. In addition, the use of inappropriate statistical tests may give false impressions of close agreement. Standardisation of methods for the measurement of D are required if these techniques are to become useful tools, for example in monitoring changes in the disease burden of multiple sclerosis. (orig.)

  15. Quantitative diffusion characteristics of the human brain depend on MRI sequence parameters

    International Nuclear Information System (INIS)

    Wilson, M.; Blumhardt, L.D.; Morgan, P.S.

    2002-01-01

    Quantitative diffusion-weighted MRI has been applied to the study of neurological diseases, including multiple sclerosis, where the molecular self-diffusion coefficient D has been measured in both lesions and normal-appearing white matter. Histograms of D have been used as a novel measure of the ''lesion load'', with potential applications that include the monitoring of efficacy in new treatment trials. However different ways of measuring D may affect its value, making comparison between different centres and research groups impossible. We aimed to assess the effect, if any, of using two different MRI sequences on the value of D. We studied 13 healthy volunteers, using two different quantitative diffusion sequences (including different b max values and gradient applications). Maps of D were analysed using both regions of interest (ROI) in white matter and ''whole brain'' histograms, and compared between the two sequences. In addition, we studied three standardised test liquids (with known values of D) using both sequences. Histograms from the two sequences had different distributions, with a greater spread and higher peak position from the sequence with lower b max . This greater spread of D was also evident in the white matter and test liquid ROI. ''Limits of agreement'' analysis demonstrated that the differences could be clinically relevant, despite significant correlations between the sequences obtained using simple rank methods. We conclude that different quantitative diffusion sequences are unlikely to produce directly comparable values of D, particularly if different b max values are used. In addition, the use of inappropriate statistical tests may give false impressions of close agreement. Standardisation of methods for the measurement of D are required if these techniques are to become useful tools, for example in monitoring changes in the disease burden of multiple sclerosis. (orig.)

  16. Limitations for qualitative and quantitative neutron activation analysis using reactor neutrons

    International Nuclear Information System (INIS)

    El-Abbady, W.H.; El-Tanahy, Z.H.; El-Hagg, A.A.; Hassan, A.M.

    1999-01-01

    In this work, the most important limitations for qualitative and quantitative analysis using reactor neutrons for activation are reviewed. Each limitation is discussed using different examples of activated samples. Photopeak estimation, nuclear reactions interference and neutron flux measurements are taken into consideration. Solutions for high accuracy evaluation in neutron activation analysis applications are given. (author)

  17. Quantitative structure-activity relationships of salicylamide neuroleptic agents.

    Science.gov (United States)

    Gupta, S P; Saha, R N; Singh, P

    1990-05-01

    The in vitro antidopamine activity of substituted N-[(1-alkyl-2-pyrrolidinyl)methyl]-6-methoxysalicylamides was found to be well correlated with the hydrophobic and electronic nature of substituents at the 3-position, and with the steric nature of groups replacing the hydrogen atom of the salicyl hydroxy group. In contrast, only the hydrophobic and steric characteristics were found to be important in the in vivo activity of these neuroleptics. This difference suggests that different mechanisms are probably involved in their in vitro and in vivo actions, and that the relevant receptors are slightly different in structure. The in vitro results suggest that electron donation by the 3-substituent strengthens the formation of a hydrogen bond between the carbonyl group of the amide moiety and a hydrogen of the receptor.

  18. Quantitative critical thinking: Student activities using Bayesian updating

    Science.gov (United States)

    Warren, Aaron R.

    2018-05-01

    One of the central roles of physics education is the development of students' ability to evaluate proposed hypotheses and models. This ability is important not just for students' understanding of physics but also to prepare students for future learning beyond physics. In particular, it is often hoped that students will better understand the manner in which physicists leverage the availability of prior knowledge to guide and constrain the construction of new knowledge. Here, we discuss how the use of Bayes' Theorem to update the estimated likelihood of hypotheses and models can help achieve these educational goals through its integration with evaluative activities that use hypothetico-deductive reasoning. Several types of classroom and laboratory activities are presented that engage students in the practice of Bayesian likelihood updating on the basis of either consistency with experimental data or consistency with pre-established principles and models. This approach is sufficiently simple for introductory physics students while offering a robust mechanism to guide relatively sophisticated student reflection concerning models, hypotheses, and problem-solutions. A quasi-experimental study utilizing algebra-based introductory courses is presented to assess the impact of these activities on student epistemological development. The results indicate gains on the Epistemological Beliefs Assessment for Physical Science (EBAPS) at a minimal cost of class-time.

  19. Quantitative assessment of accumulation of radionuclides in fish organism in dependence on water temperature

    International Nuclear Information System (INIS)

    Katkov, A.E.

    1980-01-01

    Eperimentally studied are the changes of levels of several indices of radionuclide metabolism in fishes in dependence on water temperature at its absorption directly from water and at introduction into the digestive tract. Presented are the coefficients of radionuclide storage by the fish tissues in the dependence on temperature (scales and fins, gills, head, intestines, skin, muscles, axial skeleton) and the coefficients of radionuclide retention in the whole fish. It is shown that the connection between the coefficient of radionuclide storage in the fish organism and water temperature is described by the logarithmic dependence. At the systematic entering of radionuclides into the digestive tract the retention coefficient of them in the organism expressed in the form of the ratio of residual quantity in the fish to the quantity in day dose is constant

  20. Acceptability criteria for linear dependence in validating UV-spectrophotometric methods of quantitative determination in forensic and toxicological analysis

    Directory of Open Access Journals (Sweden)

    L. Yu. Klimenko

    2014-08-01

    Full Text Available Introduction. This article is the result of authors’ research in the field of development of the approaches to validation of quantitative determination methods for purposes of forensic and toxicological analysis and devoted to the problem of acceptability criteria formation for validation parameter «linearity/calibration model». The aim of research. The purpose of this paper is to analyse the present approaches to acceptability estimation of the calibration model chosen for method description according to the requirements of the international guidances, to form the own approaches to acceptability estimation of the linear dependence when carrying out the validation of UV-spectrophotometric methods of quantitative determination for forensic and toxicological analysis. Materials and methods. UV-spectrophotometric method of doxylamine quantitative determination in blood. Results. The approaches to acceptability estimation of calibration models when carrying out the validation of bioanalytical methods is stated in international papers, namely «Guidance for Industry: Bioanalytical method validation» (U.S. FDA, 2001, «Standard Practices for Method Validation in Forensic Toxicology» (SWGTOX, 2012, «Guidance for the Validation of Analytical Methodology and Calibration of Equipment used for Testing of Illicit Drugs in Seized Materials and Biological Specimens» (UNODC, 2009 and «Guideline on validation of bioanalytical methods» (ЕМА, 2011 have been analysed. It has been suggested to be guided by domestic developments in the field of validation of analysis methods for medicines and, particularly, by the approaches to validation methods in the variant of the calibration curve method for forming the acceptability criteria of the obtained linear dependences when carrying out the validation of UV-spectrophotometric methods of quantitative determination for forensic and toxicological analysis. The choice of the method of calibration curve is

  1. Account of spectral dependence of instrumental factor in quantitative X-ray fluorescence analysis

    International Nuclear Information System (INIS)

    Pershin, N.V.; Mosichev, V.I.

    1990-01-01

    A new method for calibration of X-ray fluorescence spectrometers using scanning spectrometric channel is proposed. The method is based on a separate account of matrix and instrumental effects and needs no calibration standards for the element analysed. For calibration in the whole spectral range of XRS (0.03-1.0 nm) it is sufficient to have from 10 to 15 pure element emitters made of most wide spread elements. The method provides rapid development of quantitative analysis for the elements which are not provided with standard samples and preparation of pure element emitters for which is impossible or problematic. The practical verification of the method was made by analysing a set of 146 standard samples covering a wide group of alloys. The mean relative error of the method was 3-5 % in an analytical range of 0.1-3.0 wt %

  2. Prenatal and adult androgen activities in alcohol dependence.

    Science.gov (United States)

    Lenz, B; Mühle, C; Braun, B; Weinland, C; Bouna-Pyrrou, P; Behrens, J; Kubis, S; Mikolaiczik, K; Muschler, M-R; Saigali, S; Sibach, M; Tanovska, P; Huber, S E; Hoppe, U; Eichler, A; Heinrich, H; Moll, G H; Engel, A; Goecke, T W; Beckmann, M W; Fasching, P A; Müller, C P; Kornhuber, J

    2017-07-01

    Alcohol dependence is more prevalent in men than in women. The evidence for how prenatal and adult androgens influence alcohol dependence is limited. We investigated the effects of prenatal and adult androgen activity on alcohol dependence. Moreover, we studied how the behaviours of pregnant women affect their children's prenatal androgen load. We quantified prenatal androgen markers (e.g., second-to-fourth finger length ratio [2D : 4D]) and blood androgens in 200 early-abstinent alcohol-dependent in-patients and 240 controls (2013-2015, including a 12-month follow-up). We also surveyed 134 women during pregnancy (2005-2007) and measured the 2D : 4D of their children (2013-2016). The prenatal androgen loads were higher in the male alcohol-dependent patients compared to the controls (lower 2D : 4D, P = 0.004) and correlated positively with the patients' liver transaminase activities (P alcohol withdrawal severity (P = 0.019). Higher prenatal androgen loads and increasing androgen levels during withdrawal predicted earlier and more frequent 12-month hospital readmission in alcohol-dependent patients (P alcohol (P = 0.010) and tobacco consumption (P = 0.017), and lifetime stressors (P = 0.019) of women during pregnancy related positively to their children's prenatal androgen loads (lower 2D : 4D). Androgen activities in alcohol-dependent patients and behaviours of pregnant women represent novel preventive and therapeutic targets of alcohol dependence. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Quantitative forecasting of the 27-day recurrent magnetic activity

    International Nuclear Information System (INIS)

    Akasofu, S.-I.; Olmsted, C.

    1988-01-01

    It is shown that forecasting of the recurrent geomagnetic activity is reduced to predicting the solar wind speed V and the magnitude B of the Interplanetary Magnetic Field IMF for a 27-day period. It is shown further that the prediction of V and B is reduced to inferring the geometry of the neutral line on the source surface which is an imaginary spherical surface of radius 2.5 solar radii. For this purpose, we note that it has recently been found that the neutral line on the source surface can be reproduced fairly accurately by a dipole at the center of the Sun and a few dipoles on the photosphere. This finding provides us with an opportunity to predict the geometry of the neutral line on the source surface by extrapolating time variations of the magnitude and orientation of the dipoles. We show that time variations of the dipoles are fairly systematic, making the extrapolation possible. (author)

  4. Symptoms of exercise dependence and physical activity in students.

    Science.gov (United States)

    MacLaren, Vance V; Best, Lisa A

    2007-12-01

    Health professionals recognize the benefits of moderate physical activity and encourage clients to engage in some form of activity on a regular basis. In spite of these recognized benefits, there are growing concerns that some may exercise at levels detrimental to health. The term exercise dependence refers to those individuals whose extreme exercise schedules interfere with their social, occupational, and family lives. The purpose of this study was to examine the relationship between weekly exercise habits and scores on the Exercise Dependence Questionnaire in a sample of undergraduate students (213 women and 79 men). Overall, participants who reported high activity scored higher than those reporting low activity on subscales measuring interference with family and social life, positive reward, withdrawal, exercise for social reasons, exercise for health reasons, and stereotyped behavior.

  5. The cell biology of T-dependent B cell activation

    DEFF Research Database (Denmark)

    Owens, T; Zeine, R

    1989-01-01

    The requirement that CD4+ helper T cells recognize antigen in association with class II Major Histocompatibility Complex (MHC) encoded molecules constrains T cells to activation through intercellular interaction. The cell biology of the interactions between CD4+ T cells and antigen-presenting cells...... includes multipoint intermolecular interactions that probably involve aggregation of both polymorphic and monomorphic T cell surface molecules. Such aggregations have been shown in vitro to markedly enhance and, in some cases, induce T cell activation. The production of T-derived lymphokines that have been...... implicated in B cell activation is dependent on the T cell receptor for antigen and its associated CD3 signalling complex. T-dependent help for B cell activation is therefore similarly MHC-restricted and involves T-B intercellular interaction. Recent reports that describe antigen-independent B cell...

  6. Activity-dependent modulation of neural circuit synaptic connectivity

    Directory of Open Access Journals (Sweden)

    Charles R Tessier

    2009-07-01

    Full Text Available In many nervous systems, the establishment of neural circuits is known to proceed via a two-stage process; 1 early, activity-independent wiring to produce a rough map characterized by excessive synaptic connections, and 2 subsequent, use-dependent pruning to eliminate inappropriate connections and reinforce maintained synapses. In invertebrates, however, evidence of the activity-dependent phase of synaptic refinement has been elusive, and the dogma has long been that invertebrate circuits are “hard-wired” in a purely activity-independent manner. This conclusion has been challenged recently through the use of new transgenic tools employed in the powerful Drosophila system, which have allowed unprecedented temporal control and single neuron imaging resolution. These recent studies reveal that activity-dependent mechanisms are indeed required to refine circuit maps in Drosophila during precise, restricted windows of late-phase development. Such mechanisms of circuit refinement may be key to understanding a number of human neurological diseases, including developmental disorders such as Fragile X syndrome (FXS and autism, which are hypothesized to result from defects in synaptic connectivity and activity-dependent circuit function. This review focuses on our current understanding of activity-dependent synaptic connectivity in Drosophila, primarily through analyzing the role of the fragile X mental retardation protein (FMRP in the Drosophila FXS disease model. The particular emphasis of this review is on the expanding array of new genetically-encoded tools that are allowing cellular events and molecular players to be dissected with ever greater precision and detail.

  7. Quantitative Structure-Activity Relationships and Docking Studies of Calcitonin Gene-Related Peptide Antagonists

    DEFF Research Database (Denmark)

    Jenssen, Håvard; Mehrabian, Mohadeseh; Kyani, Anahita

    2012-01-01

    Defining the role of calcitonin gene-related peptide in migraine pathogenesis could lead to the application of calcitonin gene-related peptide antagonists as novel migraine therapeutics. In this work, quantitative structure-activity relationship modeling of biological activities of a large range...... of calcitonin gene-related peptide antagonists was performed using a panel of physicochemical descriptors. The computational studies evaluated different variable selection techniques and demonstrated shuffling stepwise multiple linear regression to be superior over genetic algorithm-multiple linear regression....... The linear quantitative structure-activity relationship model revealed better statistical parameters of cross-validation in comparison with the non-linear support vector regression technique. Implementing only five peptide descriptors into this linear quantitative structure-activity relationship model...

  8. Defect evolution in cosmology and condensed matter quantitative analysis with the velocity-dependent one-scale model

    CERN Document Server

    Martins, C J A P

    2016-01-01

    This book sheds new light on topological defects in widely differing systems, using the Velocity-Dependent One-Scale Model to better understand their evolution. Topological defects – cosmic strings, monopoles, domain walls or others - necessarily form at cosmological (and condensed matter) phase transitions. If they are stable and long-lived they will be fossil relics of higher-energy physics. Understanding their behaviour and consequences is a key part of any serious attempt to understand the universe, and this requires modelling their evolution. The velocity-dependent one-scale model is the only fully quantitative model of defect network evolution, and the canonical model in the field. This book provides a review of the model, explaining its physical content and describing its broad range of applicability.

  9. Quantitative size-dependent structure and strain determination of CdSe nanoparticles using atomic pair distribution function analysis

    Energy Technology Data Exchange (ETDEWEB)

    Masadeh, A S; Bozin, E S; Farrow, C L; Paglia, G; Juhas, P; Billinge, S J. L.; Karkamkar, A; Kanatzidis, M G [Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824-1116 (United States); Department of Chemistry, Michigan State University, East Lansing, Michigan 48824-1116 (United States)

    2007-09-15

    The size-dependent structure of CdSe nanoparticles, with diameters ranging from 2 to 4 nm, has been studied using the atomic pair distribution function (PDF) method. The core structure of the measured CdSe nanoparticles can be described in terms of the wurtzite atomic structure with extensive stacking faults. The density of faults in the nanoparticles is {approx}50%. The diameter of the core region was extracted directly from the PDF data and is in good agreement with the diameter obtained from standard characterization methods, suggesting that there is little surface amorphous region. A compressive strain was measured in the Cd-Se bond length that increases with decreasing particle size being 0.5% with respect to bulk CdSe for the 2 nm diameter particles. This study demonstrates the size-dependent quantitative structural information that can be obtained even from very small nanoparticles using the PDF approach.

  10. Dependence of PERT endpoint on endogenous lipase activity.

    Science.gov (United States)

    Gao, Wen-Yi; Mulberg, Andrew E

    2014-11-01

    To clarify and to understand the potential for misinterpretation of change in fecal fat quantitation during pancreatic enzyme replacement therapy (PERT) trials for treatment of exocrine pancreatic insufficiency. Analysis of clinical trials submitted to the U.S. Food and Drug Administration (FDA) for approval of PERT that enrolled 123 cystic fibrosis adult and pediatric patients treated with Creon, Pertzye, Ultresa, and Zenpep. The CFA% defines lipase activity as a percentage of converting substrate of "Total Daily Dietary Fat Intake." PERT trials performed to date have modified the definition to converting the "Shared Daily Fat Intake," generating "Partial CFA" for the exogenous lipase: the higher the activity of coexisting endogenous lipase, the lower the "Partial CFA" of exogenous measured. This review shows that "Partial CFA" is not CFA. Enrollment of patients with low HPLA during treatment may improve the interpretability of "Partial CFA" measured by PERT trials.

  11. Quantitative determination of spin-dependent quasiparticle renormalization in ferromagnetic 3d metals

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Barriga, Jaime; Varykhalov, Andrei; Fink, Joerg; Rader, Oliver; Duerr, Hermann; Eberhardt, Wolfgang [Bessy GmbH, Berlin (Germany)

    2008-07-01

    Spin dependent low-energy electronic excitations in 3d ferromagnets are of special interest due to the need of a microscopic understanding of the electronic structure of solids. Low-energy electrons (or holes) become dressed by a cloud of excitations resulting in quasiparticles of a finite lifetime and a different effective mass. These type of excitations have been studied by many theoretical methods, and it has been found that because of many body effects no sharp quasiparticle peaks exist for binding energies larger than 2 eV. Interestingly, it has been shown that strong correlation effects could particularly affect majority spin electrons, leading to a pronounced damping of quasiparticles at binding energies around 2 eV and above. In order to give an experimental corroboration to these findings, we have performed a systematic study of the spin-dependent quasiparticle lifetime and band structure of ferromagnetic 3d transition metal surfaces by means of spin and angle-resolved photoemission spectroscopy. On hcp Co(0001), fcc Ni(111) and bcc Fe(110), we have found a more pronounced renormalization of the majority spin quasiparticle spectral weight going from Ni to Co which are both strong ferromagnets. For Fe, a weak ferromagnet, such a process becomes more prominent in the minority channel.

  12. The Arabidopsis thaliana Cyclic-Nucleotide-Dependent Response – a Quantitative Proteomic and Phosphoproteomic Analysis

    KAUST Repository

    Alqurashi, May M.

    2013-01-01

    monophosphate (cAMP), has been shown to be a second messenger in abiotic and biotic stress responses. However, little is known about the precise role of cAMP in plants and in the down-stream activation of kinases, and hence cAMP

  13. Arrhenius temperature dependence of in vitro tissue plasminogen activator thrombolysis

    International Nuclear Information System (INIS)

    Shaw, George J; Dhamija, Ashima; Bavani, Nazli; Wagner, Kenneth R; Holland, Christy K

    2007-01-01

    Stroke is a devastating disease and a leading cause of death and disability. Currently, the only FDA approved therapy for acute ischemic stroke is the intravenous administration of the thrombolytic medication, recombinant tissue plasminogen activator (tPA). However, this treatment has many contraindications and can have dangerous side effects such as intra-cerebral hemorrhage. These treatment limitations have led to much interest in potential adjunctive therapies, such as therapeutic hypothermia (T ≤ 35 deg. C) and ultrasound enhanced thrombolysis. Such interest may lead to combining these therapies with tPA to treat stroke, however little is known about the effects of temperature on the thrombolytic efficacy of tPA. In this work, we measure the temperature dependence of the fractional clot mass loss Δm(T) resulting from tPA exposure in an in vitro human clot model. We find that the temperature dependence is well described by an Arrhenius temperature dependence with an effective activation energy E eff of 42.0 ± 0.9 kJ mole -1 . E eff approximates the activation energy of the plasminogen-to-plasmin reaction of 48.9 kJ mole -1 . A model to explain this temperature dependence is proposed. These results will be useful in predicting the effects of temperature in future lytic therapies

  14. Arrhenius temperature dependence of in vitro tissue plasminogen activator thrombolysis

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, George J [Department of Emergency Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0769 (United States); Dhamija, Ashima [Department of Emergency Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0769 (United States); Bavani, Nazli [Department of Emergency Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0769 (United States); Wagner, Kenneth R [Department of Neurology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0769 (United States); Holland, Christy K [Department of Biomedical Engineering, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0769 (United States)

    2007-06-07

    Stroke is a devastating disease and a leading cause of death and disability. Currently, the only FDA approved therapy for acute ischemic stroke is the intravenous administration of the thrombolytic medication, recombinant tissue plasminogen activator (tPA). However, this treatment has many contraindications and can have dangerous side effects such as intra-cerebral hemorrhage. These treatment limitations have led to much interest in potential adjunctive therapies, such as therapeutic hypothermia (T {<=} 35 deg. C) and ultrasound enhanced thrombolysis. Such interest may lead to combining these therapies with tPA to treat stroke, however little is known about the effects of temperature on the thrombolytic efficacy of tPA. In this work, we measure the temperature dependence of the fractional clot mass loss {delta}m(T) resulting from tPA exposure in an in vitro human clot model. We find that the temperature dependence is well described by an Arrhenius temperature dependence with an effective activation energy E{sub eff} of 42.0 {+-} 0.9 kJ mole{sup -1}. E{sub eff} approximates the activation energy of the plasminogen-to-plasmin reaction of 48.9 kJ mole{sup -1}. A model to explain this temperature dependence is proposed. These results will be useful in predicting the effects of temperature in future lytic therapies.

  15. [Flexibility of cognitive activity depends on its context].

    Science.gov (United States)

    Kostandov, É A

    2010-01-01

    The main purpose of this survey is to explain the importance of set-shifting for a flexible cognitive activity. Working memory overload may result in set-shifting slowdown, i.e., in a more rigid set and in a less flexible cognitive activity. This effect displays itself in an increase of erroneous perceptions of external stimuli. Set rigidity level also depends on the cognitive activity context (i.e., on the type of external stimuli the person has to deal with). We analyzed EEG-coherence function and induced synchronization/desynchronization responses in theta (4-7 Hz) and low alpha (8-10 Hz) bands. Basing on these data, we discuss the role of tonic and phasic forms of cortico-hippocampal and fronto-thalamic systems' activation in cognitive activity flexibility.

  16. The watercolor effect: quantitative evidence for luminance-dependent mechanisms of long-range color assimilation.

    Science.gov (United States)

    Devinck, Frédéric; Delahunt, Peter B; Hardy, Joseph L; Spillmann, Lothar; Werner, John S

    2005-05-01

    When a dark chromatic contour delineating a figure is flanked on the inside by a brighter chromatic contour, the brighter color will spread into the entire enclosed area. This is known as the watercolor effect (WCE). Here we quantified the effect of color spreading using both color-matching and hue-cancellation tasks. Over a wide range of stimulus chromaticities, there was a reliable shift in color appearance that closely followed the direction of the inducing contour. When the contours were equated in luminance, the WCE was still present, but weak. The magnitude of the color spreading increased with increases in luminance contrast between the two contours. Additionally, as the luminance contrast between the contours increased, the chromaticity of the induced color more closely resembled that of the inside contour. The results support the hypothesis that the WCE is mediated by luminance-dependent mechanisms of long-range color assimilation.

  17. Quantitative Temperature Dependence of Longitudinal Spin Seebeck Effect at High Temperatures

    Directory of Open Access Journals (Sweden)

    Ken-ichi Uchida

    2014-11-01

    Full Text Available We report temperature-dependent measurements of longitudinal spin Seebeck effects (LSSEs in Pt/Y_{3}Fe_{5}O_{12} (YIG/Pt systems in a high temperature range from room temperature to above the Curie temperature of YIG. The experimental results show that the magnitude of the LSSE voltage in the Pt/YIG/Pt systems rapidly decreases with increasing the temperature and disappears above the Curie temperature. The critical exponent of the LSSE voltage in the Pt/YIG/Pt systems at the Curie temperature is estimated to be 3, which is much greater than that for the magnetization curve of YIG. This difference highlights the fact that the mechanism of the LSSE cannot be explained in terms of simple static magnetic properties in YIG.

  18. Impact of high (131)I-activities on quantitative (124)I-PET

    DEFF Research Database (Denmark)

    Braad, P E N; Hansen, Søren B.; Høilund-Carlsen, P F

    2015-01-01

    relevant [Formula: see text]I/[Formula: see text]I-activities were performed on a clinical PET/CT-system. Noise equivalent count rate (NECR) curves and quantitation accuracy were determined from repeated scans performed over several weeks on a decaying NEMA NU-2 1994 cylinder phantom initially filled...... [Formula: see text]I-activities was good and image quantification unaffected except at very high count rates. Quantitation accuracy and contrast recovery were uninfluenced at [Formula: see text]I-activities below 1000 MBq, whereas image noise was slightly increased. The NECR peaked at 550 MBq of [Formula......: see text]I, where it was 2.8 times lower than without [Formula: see text]I in the phantom. Quantitative peri-therapeutic [Formula: see text]I-PET is feasible....

  19. Validation of Quantitative Structure-Activity Relationship (QSAR Model for Photosensitizer Activity Prediction

    Directory of Open Access Journals (Sweden)

    Sharifuddin M. Zain

    2011-11-01

    Full Text Available Photodynamic therapy is a relatively new treatment method for cancer which utilizes a combination of oxygen, a photosensitizer and light to generate reactive singlet oxygen that eradicates tumors via direct cell-killing, vasculature damage and engagement of the immune system. Most of photosensitizers that are in clinical and pre-clinical assessments, or those that are already approved for clinical use, are mainly based on cyclic tetrapyrroles. In an attempt to discover new effective photosensitizers, we report the use of the quantitative structure-activity relationship (QSAR method to develop a model that could correlate the structural features of cyclic tetrapyrrole-based compounds with their photodynamic therapy (PDT activity. In this study, a set of 36 porphyrin derivatives was used in the model development where 24 of these compounds were in the training set and the remaining 12 compounds were in the test set. The development of the QSAR model involved the use of the multiple linear regression analysis (MLRA method. Based on the method, r2 value, r2 (CV value and r2 prediction value of 0.87, 0.71 and 0.70 were obtained. The QSAR model was also employed to predict the experimental compounds in an external test set. This external test set comprises 20 porphyrin-based compounds with experimental IC50 values ranging from 0.39 µM to 7.04 µM. Thus the model showed good correlative and predictive ability, with a predictive correlation coefficient (r2 prediction for external test set of 0.52. The developed QSAR model was used to discover some compounds as new lead photosensitizers from this external test set.

  20. Quantitative analysis of the Ca2+‐dependent regulation of delayed rectifier K+ current I Ks in rabbit ventricular myocytes

    Science.gov (United States)

    Bartos, Daniel C.; Morotti, Stefano; Ginsburg, Kenneth S.; Grandi, Eleonora

    2017-01-01

    Key points [Ca2+]i enhanced rabbit ventricular slowly activating delayed rectifier K+ current (I Ks) by negatively shifting the voltage dependence of activation and slowing deactivation, similar to perfusion of isoproterenol.Rabbit ventricular rapidly activating delayed rectifier K+ current (I Kr) amplitude and voltage dependence were unaffected by high [Ca2+]i.When measuring or simulating I Ks during an action potential, I Ks was not different during a physiological Ca2+ transient or when [Ca2+]i was buffered to 500 nm. Abstract The slowly activating delayed rectifier K+ current (I Ks) contributes to repolarization of the cardiac action potential (AP). Intracellular Ca2+ ([Ca2+]i) and β‐adrenergic receptor (β‐AR) stimulation modulate I Ks amplitude and kinetics, but details of these important I Ks regulators and their interaction are limited. We assessed the [Ca2+]i dependence of I Ks in steady‐state conditions and with dynamically changing membrane potential and [Ca2+]i during an AP. I Ks was recorded from freshly isolated rabbit ventricular myocytes using whole‐cell patch clamp. With intracellular pipette solutions that controlled free [Ca2+]i, we found that raising [Ca2+]i from 100 to 600 nm produced similar increases in I Ks as did β‐AR activation, and the effects appeared additive. Both β‐AR activation and high [Ca2+]i increased maximally activated tail I Ks, negatively shifted the voltage dependence of activation, and slowed deactivation kinetics. These data informed changes in our well‐established mathematical model of the rabbit myocyte. In both AP‐clamp experiments and simulations, I Ks recorded during a normal physiological Ca2+ transient was similar to I Ks measured with [Ca2+]i clamped at 500–600 nm. Thus, our study provides novel quantitative data as to how physiological [Ca2+]i regulates I Ks amplitude and kinetics during the normal rabbit AP. Our results suggest that micromolar [Ca2+]i, in the submembrane or junctional cleft

  1. Network-dependent modulation of brain activity during sleep.

    Science.gov (United States)

    Watanabe, Takamitsu; Kan, Shigeyuki; Koike, Takahiko; Misaki, Masaya; Konishi, Seiki; Miyauchi, Satoru; Miyahsita, Yasushi; Masuda, Naoki

    2014-09-01

    Brain activity dynamically changes even during sleep. A line of neuroimaging studies has reported changes in functional connectivity and regional activity across different sleep stages such as slow-wave sleep (SWS) and rapid-eye-movement (REM) sleep. However, it remains unclear whether and how the large-scale network activity of human brains changes within a given sleep stage. Here, we investigated modulation of network activity within sleep stages by applying the pairwise maximum entropy model to brain activity obtained by functional magnetic resonance imaging from sleeping healthy subjects. We found that the brain activity of individual brain regions and functional interactions between pairs of regions significantly increased in the default-mode network during SWS and decreased during REM sleep. In contrast, the network activity of the fronto-parietal and sensory-motor networks showed the opposite pattern. Furthermore, in the three networks, the amount of the activity changes throughout REM sleep was negatively correlated with that throughout SWS. The present findings suggest that the brain activity is dynamically modulated even in a sleep stage and that the pattern of modulation depends on the type of the large-scale brain networks. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Quantitative in vivo analyses reveal calcium-dependent phosphorylation sites and identifies a novel component of the Toxoplasma invasion motor complex.

    Directory of Open Access Journals (Sweden)

    Thomas Nebl

    2011-09-01

    Full Text Available Apicomplexan parasites depend on the invasion of host cells for survival and proliferation. Calcium-dependent signaling pathways appear to be essential for micronemal release and gliding motility, yet the target of activated kinases remains largely unknown. We have characterized calcium-dependent phosphorylation events during Toxoplasma host cell invasion. Stimulation of live tachyzoites with Ca²⁺-mobilizing drugs leads to phosphorylation of numerous parasite proteins, as shown by differential 2-DE display of ³²[P]-labeled protein extracts. Multi-dimensional Protein Identification Technology (MudPIT identified ∼546 phosphorylation sites on over 300 Toxoplasma proteins, including 10 sites on the actomyosin invasion motor. Using a Stable Isotope of Amino Acids in Culture (SILAC-based quantitative LC-MS/MS analyses we monitored changes in the abundance and phosphorylation of the invasion motor complex and defined Ca²⁺-dependent phosphorylation patterns on three of its components--GAP45, MLC1 and MyoA. Furthermore, calcium-dependent phosphorylation of six residues across GAP45, MLC1 and MyoA is correlated with invasion motor activity. By analyzing proteins that appear to associate more strongly with the invasion motor upon calcium stimulation we have also identified a novel 15-kDa Calmodulin-like protein that likely represents the MyoA Essential Light Chain of the Toxoplasma invasion motor. This suggests that invasion motor activity could be regulated not only by phosphorylation but also by the direct binding of calcium ions to this new component.

  3. Quantitatively identical orientation-dependent ionization energy and electron affinity of diindenoperylene

    Energy Technology Data Exchange (ETDEWEB)

    Han, W. N.; Yonezawa, K.; Makino, R.; Kato, K.; Hinderhofer, A.; Ueno, N.; Kera, S. [Graduate School of Advanced Integration Science, Chiba University 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Murdey, R.; Shiraishi, R.; Yoshida, H.; Sato, N. [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan)

    2013-12-16

    Molecular orientation dependences of the ionization energy (IE) and the electron affinity (EA) of diindenoperylene (DIP) films were studied by using ultraviolet photoemission spectroscopy and inverse photoemission spectroscopy. The molecular orientation was controlled by preparing the DIP films on graphite and SiO{sub 2} substrates. The threshold IE and EA of DIP thin films were determined to be 5.81 and 3.53 eV for the film of flat-lying DIP orientation, respectively, and 5.38 and 3.13 eV for the film of standing DIP orientation, respectively. The result indicates that the IE and EA for the flat-lying film are larger by 0.4 eV and the frontier orbital states shift away from the vacuum level compared to the standing film. This rigid energy shift is ascribed to a surface-electrostatic potential produced by the intramolecular polar bond (>C{sup −}-H{sup +}) for standing orientation and π-electron tailing to vacuum for flat-lying orientation.

  4. Lateral dimension-dependent antibacterial activity of graphene oxide sheets.

    Science.gov (United States)

    Liu, Shaobin; Hu, Ming; Zeng, Tingying Helen; Wu, Ran; Jiang, Rongrong; Wei, Jun; Wang, Liang; Kong, Jing; Chen, Yuan

    2012-08-21

    Graphene oxide (GO) is a promising precursor to produce graphene-family nanomaterials for various applications. Their potential health and environmental impacts need a good understanding of their cellular interactions. Many factors may influence their biological interactions with cells, and the lateral dimension of GO sheets is one of the most relevant material properties. In this study, a model bacterium, Escherichia coli ( E. coli ), was used to evaluate the antibacterial activity of well-dispersed GO sheets, whose lateral size differs by more than 100 times. Our results show that the antibacterial activity of GO sheets toward E. coli cells is lateral size dependent. Larger GO sheets show stronger antibacterial activity than do smaller ones, and they have different time- and concentration-dependent antibacterial activities. Large GO sheets lead to most cell loss after 1 h incubation, and their concentration strongly influences antibacterial activity at relative low concentration (oxidation capacity toward glutathione is similar, consistent with X-ray photoelectron spectroscopy and ultraviolet-visible absorption spectroscopy results. This suggests the lateral size-dependent antibacterial activity of GO sheets is caused by neither their aggregation states, nor oxidation capacity. Atomic force microscope analysis of GO sheets and cells shows that GO sheets interact strongly with cells. Large GO sheets more easily cover cells, and cells cannot proliferate once fully covered, resulting in the cell viability loss observed in the followed colony counting test. In contrast, small GO sheets adhere to the bacterial surfaces, which cannot effectively isolate cells from environment. This study highlights the importance of tailoring the lateral dimension of GO sheets to optimize the application potential with minimal risks for environmental health and safety.

  5. The temperature dependence of the BK channel activity - kinetics, thermodynamics, and long-range correlations.

    Science.gov (United States)

    Wawrzkiewicz-Jałowiecka, Agata; Dworakowska, Beata; Grzywna, Zbigniew J

    2017-10-01

    Large-conductance, voltage dependent, Ca 2+ -activated potassium channels (BK) are transmembrane proteins that regulate many biological processes by controlling potassium flow across cell membranes. Here, we investigate to what extent temperature (in the range of 17-37°C with ΔT=5°C step) is a regulating parameter of kinetic properties of the channel gating and memory effect in the series of dwell-time series of subsequent channel's states, at membrane depolarization and hyperpolarization. The obtained results indicate that temperature affects strongly the BK channels' gating, but, counterintuitively, it exerts no effect on the long-range correlations, as measured by the Hurst coefficient. Quantitative differences between dependencies of appropriate channel's characteristics on temperature are evident for different regimes of voltage. Examining the characteristics of BK channel activity as a function of temperature allows to estimate the net activation energy (E act ) and changes of thermodynamic parameters (ΔH, ΔS, ΔG) by channel opening. Larger E act corresponds to the channel activity at membrane hyperpolarization. The analysis of entropy and enthalpy changes of closed to open channel's transition suggest the entropy-driven nature of the increase of open state probability during voltage activation and supports the hypothesis about the voltage-dependent geometry of the channel vestibule. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Online Activity Levels Are Related to Caffeine Dependency.

    Science.gov (United States)

    Phillips, James G; Landhuis, C Erik; Shepherd, Daniel; Ogeil, Rowan P

    2016-05-01

    Online activity could serve in the future as behavioral markers of emotional states for computer systems (i.e., affective computing). Hence, this study considered relationships between self-reported stimulant use and online study patterns. Sixty-two undergraduate psychology students estimated their daily caffeine use, and this was related to study patterns as tracked by their use of a Learning Management System (Blackboard). Caffeine dependency was associated with less time spent online, lower rates of file access, and fewer online activities completed. Reduced breadth or depth of processing during work/study could be used as a behavioral marker of stimulant use.

  7. A quantitative structure-activity relationship to predict efficacy of granular activated carbon adsorption to control emerging contaminants.

    Science.gov (United States)

    Kennicutt, A R; Morkowchuk, L; Krein, M; Breneman, C M; Kilduff, J E

    2016-08-01

    A quantitative structure-activity relationship was developed to predict the efficacy of carbon adsorption as a control technology for endocrine-disrupting compounds, pharmaceuticals, and components of personal care products, as a tool for water quality professionals to protect public health. Here, we expand previous work to investigate a broad spectrum of molecular descriptors including subdivided surface areas, adjacency and distance matrix descriptors, electrostatic partial charges, potential energy descriptors, conformation-dependent charge descriptors, and Transferable Atom Equivalent (TAE) descriptors that characterize the regional electronic properties of molecules. We compare the efficacy of linear (Partial Least Squares) and non-linear (Support Vector Machine) machine learning methods to describe a broad chemical space and produce a user-friendly model. We employ cross-validation, y-scrambling, and external validation for quality control. The recommended Support Vector Machine model trained on 95 compounds having 23 descriptors offered a good balance between good performance statistics, low error, and low probability of over-fitting while describing a wide range of chemical features. The cross-validated model using a log-uptake (qe) response calculated at an aqueous equilibrium concentration (Ce) of 1 μM described the training dataset with an r(2) of 0.932, had a cross-validated r(2) of 0.833, and an average residual of 0.14 log units.

  8. Using Active Learning to Teach Concepts and Methods in Quantitative Biology.

    Science.gov (United States)

    Waldrop, Lindsay D; Adolph, Stephen C; Diniz Behn, Cecilia G; Braley, Emily; Drew, Joshua A; Full, Robert J; Gross, Louis J; Jungck, John A; Kohler, Brynja; Prairie, Jennifer C; Shtylla, Blerta; Miller, Laura A

    2015-11-01

    This article provides a summary of the ideas discussed at the 2015 Annual Meeting of the Society for Integrative and Comparative Biology society-wide symposium on Leading Students and Faculty to Quantitative Biology through Active Learning. It also includes a brief review of the recent advancements in incorporating active learning approaches into quantitative biology classrooms. We begin with an overview of recent literature that shows that active learning can improve students' outcomes in Science, Technology, Engineering and Math Education disciplines. We then discuss how this approach can be particularly useful when teaching topics in quantitative biology. Next, we describe some of the recent initiatives to develop hands-on activities in quantitative biology at both the graduate and the undergraduate levels. Throughout the article we provide resources for educators who wish to integrate active learning and technology into their classrooms. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  9. Quantitative assessment of motor functions post-stroke: Responsiveness of upper-extremity robotic measures and its task dependence.

    Science.gov (United States)

    Hussain, Asif; Budhota, Aamani; Contu, Sara; Kager, Simone; Vishwanath, Deshmukh A; Kuah, Christopher W K; Yam, Lester H L; Chua, Karen S G; Masia, Lorenzo; Campolo, Domenico

    2017-07-01

    Technology aided measures offer a sensitive, accurate and time-efflcient approach for the assessment of sensorimotor function after neurological impairment compared to standard clinical assessments. This preliminary study investigated the relationship between task definition and its effect on robotic measures using a planar, two degree of freedom, robotic-manipulator (H-Man). Four chronic stroke participants (49.5±11.95 years, 2 Female, FMA: 37.5±13.96) and eight healthy control participants (26.25± 4.70 years, 2 Female) participated in the study. Motor functions were evaluated using line tracing and circle tracing tasks with dominant and nondominant hand of healthy and affected vs. non affected hand of stroke participants. The results show significant dependence of quantitative measures on investigated tasks.

  10. Constructing bioactive peptides with pH-dependent activities.

    Science.gov (United States)

    Tu, Zhigang; Volk, Melanie; Shah, Khushali; Clerkin, Kevin; Liang, Jun F

    2009-08-01

    Many bioactive peptides are featured by their arginine and lysine rich contents. In this study, lysine and arginine residues in lytic peptides were selectively replaced by histidines. Although resulting histidine-containing lytic peptides had decreased activity, they did show pH-dependent cytotoxicity. The activity of the constructed histidine-containing lytic peptides increased 2-8 times as the solution pH changed from 7.4 to 5.5. More importantly, these histidine-containing peptides maintain the same cell killing mechanism as their parent peptides by causing cell lysis. Both the activity and pH-sensitivity of histidine-containing peptides are tunable by adjusting histidine substitution numbers and positions. This study has presented a general strategy to create bioactive peptides with desired pH-sensitivity to meet the needs of various applications such as cancer treatments.

  11. Quantitative differences in think tank dissemination activities in Germany, Denmark and the UK

    DEFF Research Database (Denmark)

    Kelstrup, Jesper Dahl

    2017-01-01

    in a quantitative design which compares publications, events and newspaper mentionings of samples of think tanks from a coordinated (Germany), liberal (UK) and mixed (Denmark) system in 2012. The analysis indicates that think tanks in the UK have the highest level of dissemination on all three activities when...

  12. Design of cinnamaldehyde amino acid Schiff base compounds based on the quantitative structure–activity relationship

    Science.gov (United States)

    Hui Wang; Mingyue Jiang; Shujun Li; Chung-Yun Hse; Chunde Jin; Fangli Sun; Zhuo Li

    2017-01-01

    Cinnamaldehyde amino acid Schiff base (CAAS) is a new class of safe, bioactive compounds which could be developed as potential antifungal agents for fungal infections. To design new cinnamaldehyde amino acid Schiff base compounds with high bioactivity, the quantitative structure–activity relationships (QSARs) for CAAS compounds against Aspergillus niger (A. niger) and...

  13. 76 FR 9637 - Proposed Information Collection (Veteran Suicide Prevention Online Quantitative Surveys) Activity...

    Science.gov (United States)

    2011-02-18

    ... Collection (Veteran Suicide Prevention Online Quantitative Surveys) Activity: Comment Request AGENCY... prevention of suicide among Veterans and their families. DATES: Written comments and recommendations on the.... Abstract: VA's top priority is the prevention of Veterans suicide. It is imperative to reach these at-risk...

  14. 76 FR 27384 - Agency Information Collection Activity (Veteran Suicide Prevention Online Quantitative Surveys...

    Science.gov (United States)

    2011-05-11

    ... Collection Activity (Veteran Suicide Prevention Online Quantitative Surveys) Under OMB Review AGENCY.... Abstract: VA's top priority is the prevention of Veterans suicide. It is imperative to reach these at-risk... families' awareness of VA's suicide prevention and mental health support services. In addition, the surveys...

  15. A biology-based approach for quantitative structure-activity relationships (QSARs) in ecotoxicity.

    NARCIS (Netherlands)

    Jager, T.; Kooijman, S.A.L.M.

    2009-01-01

    Quantitative structure-activity relationships (QSARs) for ecotoxicity can be used to fill data gaps and limit toxicity testing on animals. QSAR development may additionally reveal mechanistic information based on observed patterns in the data. However, the use of descriptive summary statistics for

  16. Quantitative structure-activity relationships for green algae growth inhibition by polymer particles.

    NARCIS (Netherlands)

    Nolte, Tom M; Peijnenburg, Willie J G M; Hendriks, A Jan; van de Meent, Dik

    After use and disposal of chemical products, many types of polymer particles end up in the aquatic environment with potential toxic effects to primary producers like green algae. In this study, we have developed Quantitative Structure-Activity Relationships (QSARs) for a set of highly structural

  17. Quantitative Determination of Telomerase Activity in Breast Cancer and Benign Breast Diseases

    Czech Academy of Sciences Publication Activity Database

    Šimíčková, M.; Nekulová, M.; Pecen, Ladislav; Černoch, M.; Vagundová, M.; Pačovský, Z.

    2001-01-01

    Roč. 48, č. 4 (2001), s. 267-273 ISSN 0028-2685 R&D Projects: GA MZd NM17 Institutional research plan: AV0Z1030915 Keywords : telomerase activity * quantitative analysis * breast cancer * benign breast diseases * prognisis Subject RIV: BA - General Mathematics Impact factor: 0.637, year: 2001

  18. Quantitative Measurement of Physical Activity in Acute Ischemic Stroke and Transient Ischemic Attack

    DEFF Research Database (Denmark)

    Strømmen, Anna Maria; Christensen, Thomas; Jensen, Kai

    2014-01-01

    BACKGROUND AND PURPOSE: The purpose of this study was to quantitatively measure and describe the amount and pattern of physical activity in patients within the first week after acute ischemic stroke and transient ischemic attack using accelerometers. METHODS: A total of 100 patients with acute is...

  19. Quantitative Structure – Antioxidant Activity Relationships of Flavonoid Compounds

    Directory of Open Access Journals (Sweden)

    Károly Héberger

    2004-12-01

    Full Text Available A quantitative structure – antioxidant activity relationship (QSAR study of 36 flavonoids was performed using the partial least squares projection of latent structures (PLS method. The chemical structures of the flavonoids have been characterized by constitutional descriptors, two-dimensional topological and connectivity indices. Our PLS model gave a proper description and a suitable prediction of the antioxidant activities of a diverse set of flavonoids having clustering tendency.

  20. Task-dependent modulation of oscillatory neural activity during movements

    DEFF Research Database (Denmark)

    Herz, D. M.; Christensen, M. S.; Reck, C.

    2011-01-01

    connectivity was strongest between central and cerebellar regions. Our results show that neural coupling within motor networks is modulated in distinct frequency bands depending on the motor task. They provide evidence that dynamic causal modeling in combination with EEG source analysis is a valuable tool......Neural oscillations in different frequency bands have been observed in a range of sensorimotor tasks and have been linked to coupling of spatially distinct neurons. The goal of this study was to detect a general motor network that is activated during phasic and tonic movements and to study the task......-dependent modulation of frequency coupling within this network. To this end we recorded 122-multichannel EEG in 13 healthy subjects while they performed three simple motor tasks. EEG data source modeling using individual MR images was carried out with a multiple source beamformer approach. A bilateral motor network...

  1. Power-dependent photocatalytic activity of ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Chun, So Yeon; Han, Noh Soo; Jeong, Seong Hyun; Park, Seung Min; Song, Jae Kyu [Dept. of Chemistry, Kyung Hee University, Seoul (Korea, Republic of); Moon, Cheol Joo; Choi, Myong Yong [Dept. of Chemistry (BK21) and Research Institute of Natural Science, Gyeongsang NationalUniversity, Jinju (Korea, Republic of)

    2017-03-15

    the power-dependent photocatalytic activity of ZnO was examined for the photoreduction processes of Rh101 and AN in the presence of hole scavengers, where the fluorescence spectra were measured as a function of irradiation time and excitation intensity. The concentration of the reactants decreased, while the concentration of the products increased accordingly, which indicated the single-electron reduction process by electrons supplied from the conduction band of ZnO. Despite the single-electron process, the efficiency of the photoreaction depended nonlinearly on the excitation intensity, which was explained by the saturation of defect states in ZnO. The enhanced ratio of available electrons in ZnO led to a superlinear increase in the photoreduction efficiency, while the single-electron process linearly reflected the electrons available in ZnO.

  2. Length and activation dependent variations in muscle shear wave speed

    International Nuclear Information System (INIS)

    Chernak, L A; DeWall, R J; Lee, K S; Thelen, D G

    2013-01-01

    Muscle stiffness is known to vary as a result of a variety of disease states, yet current clinical methods for quantifying muscle stiffness have limitations including cost and availability. We investigated the capability of shear wave elastography (SWE) to measure variations in gastrocnemius shear wave speed induced via active contraction and passive stretch. Ten healthy young adults were tested. Shear wave speeds were measured using a SWE transducer positioned over the medial gastrocnemius at ankle angles ranging from maximum dorsiflexion to maximum plantarflexion. Shear wave speeds were also measured during voluntary plantarflexor contractions at a fixed ankle angle. Average shear wave speed increased significantly from 2.6 to 5.6 m s –1 with passive dorsiflexion and the knee in an extended posture, but did not vary with dorsiflexion when the gastrocnemius was shortened in a flexed knee posture. During active contractions, shear wave speed monotonically varied with the net ankle moment generated, reaching 8.3 m s –1 in the maximally contracted condition. There was a linear correlation between shear wave speed and net ankle moment in both the active and passive conditions; however, the slope of this linear relationship was significantly steeper for the data collected during passive loading conditions. The results show that SWE is a promising approach for quantitatively assessing changes in mechanical muscle loading. However, the differential effect of active and passive loading on shear wave speed makes it important to carefully consider the relevant loading conditions in which to use SWE to characterize in vivo muscle properties. (paper)

  3. Shaping inhibition: activity dependent structural plasticity of GABAergic synapses

    Directory of Open Access Journals (Sweden)

    Carmen E Flores

    2014-10-01

    Full Text Available Inhibitory transmission through the neurotransmitter Ɣ-aminobutyric acid (GABA shapes network activity in the mammalian cerebral cortex by filtering synaptic incoming information and dictating the activity of principal cells. The incredibly diverse population of cortical neurons that use GABA as neurotransmitter shows an equally diverse range of mechanisms that regulate changes in the strength of GABAergic synaptic transmission and allow them to dynamically follow and command the activity of neuronal ensembles. Similarly to glutamatergic synaptic transmission, activity-dependent functional changes in inhibitory neurotransmission are accompanied by alterations in GABAergic synapse structure that range from morphological reorganization of postsynaptic density to de novo formation and elimination of inhibitory contacts. Here we review several aspects of structural plasticity of inhibitory synapses, including its induction by different forms of neuronal activity, behavioral and sensory experience and the molecular mechanisms and signaling pathways involved. We discuss the functional consequences of GABAergic synapse structural plasticity for information processing and memory formation in view of the heterogenous nature of the structural plasticity phenomena affecting inhibitory synapses impinging on somatic and dendritic compartments of cortical and hippocampal neurons.

  4. From retinal waves to activity-dependent retinogeniculate map development.

    Science.gov (United States)

    Markowitz, Jeffrey; Cao, Yongqiang; Grossberg, Stephen

    2012-01-01

    A neural model is described of how spontaneous retinal waves are formed in infant mammals, and how these waves organize activity-dependent development of a topographic map in the lateral geniculate nucleus, with connections from each eye segregated into separate anatomical layers. The model simulates the spontaneous behavior of starburst amacrine cells and retinal ganglion cells during the production of retinal waves during the first few weeks of mammalian postnatal development. It proposes how excitatory and inhibitory mechanisms within individual cells, such as Ca(2+)-activated K(+) channels, and cAMP currents and signaling cascades, can modulate the spatiotemporal dynamics of waves, notably by controlling the after-hyperpolarization currents of starburst amacrine cells. Given the critical role of the geniculate map in the development of visual cortex, these results provide a foundation for analyzing the temporal dynamics whereby the visual cortex itself develops.

  5. From retinal waves to activity-dependent retinogeniculate map development.

    Directory of Open Access Journals (Sweden)

    Jeffrey Markowitz

    Full Text Available A neural model is described of how spontaneous retinal waves are formed in infant mammals, and how these waves organize activity-dependent development of a topographic map in the lateral geniculate nucleus, with connections from each eye segregated into separate anatomical layers. The model simulates the spontaneous behavior of starburst amacrine cells and retinal ganglion cells during the production of retinal waves during the first few weeks of mammalian postnatal development. It proposes how excitatory and inhibitory mechanisms within individual cells, such as Ca(2+-activated K(+ channels, and cAMP currents and signaling cascades, can modulate the spatiotemporal dynamics of waves, notably by controlling the after-hyperpolarization currents of starburst amacrine cells. Given the critical role of the geniculate map in the development of visual cortex, these results provide a foundation for analyzing the temporal dynamics whereby the visual cortex itself develops.

  6. Characterizing context-dependent differential firing activity in the hippocampus and entorhinal cortex.

    Science.gov (United States)

    Prerau, Michael J; Lipton, Paul A; Eichenbaum, Howard B; Eden, Uri T

    2014-04-01

    The rat hippocampus and entorhinal cortex have been shown to possess neurons with place fields that modulate their firing properties under different behavioral contexts. Such context-dependent changes in neural activity are commonly studied through electrophysiological experiments in which a rat performs a continuous spatial alternation task on a T-maze. Previous research has analyzed context-based differential firing during this task by describing differences in the mean firing activity between left-turn and right-turn experimental trials. In this article, we develop qualitative and quantitative methods to characterize and compare changes in trial-to-trial firing rate variability for sets of experimental contexts. We apply these methods to cells in the CA1 region of hippocampus and in the dorsocaudal medial entorhinal cortex (dcMEC), characterizing the context-dependent differences in spiking activity during spatial alternation. We identify a subset of cells with context-dependent changes in firing rate variability. Additionally, we show that dcMEC populations encode turn direction uniformly throughout the T-maze stem, whereas CA1 populations encode context at major waypoints in the spatial trajectory. Our results suggest scenarios in which individual cells that sparsely provide information on turn direction might combine in the aggregate to produce a robust population encoding. Copyright © 2014 Wiley Periodicals, Inc.

  7. In Vivo Quantitative Study of Sized-Dependent Transport and Toxicity of Single Silver Nanoparticles Using Zebrafish Embryos

    Science.gov (United States)

    Lee, Kerry J.; Browning, Lauren M.; Nallathamby, Prakash D.; Desai, Tanvi; Cherukui, Pavan K.; Xu, Xiao-Hong Nancy

    2012-01-01

    Nanomaterials possess distinctive physicochemical properties (e.g., small sizes, high surface area-to-volume ratios) and promise a wide variety of applications, ranging from design of high quality consumer products to effective disease diagnosis and therapy. These properties can lead to toxic effects, potentially hindering advance in nanotechnology. In this study, we have synthesized and characterized purified and stable (non-aggregation) silver nanoparticles (Ag NPs, 41.6±9.1 nm in average diameters), and utilized early-developing (cleavage-stage) zebrafish embryos (critical aquatic and eco- species) as in vivo model organisms to probe diffusion and toxicity of Ag NPs. We found that single Ag NPs (30–72 nm diameters) passively diffused into the embryos through chorionic pores via random Brownian motion and stayed inside the embryos throughout their entire development (120 hours-post-fertilization, hpf). Dose and size dependent toxic effects of the NPs on embryonic development were observed, showing the possibility of tuning biocompatibility and toxicity of the NPs. At lower concentrations of the NPs (≤ 0.02 nM), 75–91% of embryos developed to normal zebrafish. At the higher concentrations of NPs (≥ 0.20 nM), 100% of embryos became dead. At the concentrations in between (0.02–0.2 nM), embryos developed to various deformed zebrafish. Number and sizes of individual Ag NPs embedded in tissues of normal and deformed zebrafish at 120 hpf were quantitatively analyzed, showing deformed zebrafish with higher number of larger NPs than normal zebrafish, and size-dependent nanotoxicity. By comparing with our previous studies of smaller Ag NPs (11.6±3.5 nm), the results further demonstrate striking size-dependent nanotoxicity that, at the same molar concentration, the larger Ag NPs (41.6±9.1 nm) are more toxic than the smaller Ag NPs (11.6±3.5 nm). PMID:22486336

  8. Quantitative structure-activity relationship of some 1-benzylbenzimidazole derivatives as antifungal agents

    Directory of Open Access Journals (Sweden)

    Podunavac-Kuzmanović Sanja O.

    2007-01-01

    Full Text Available In the present study, the antifungal activity of some 1-benzylbenzimidazole derivatives against yeast Saccharomyces cerevisiae was investigated. The tested benzimidazoles displayed in vitro antifungal activity and minimum inhibitory concentration (MIC was determined for all the compounds. Quantitative structure-activity relationship (QSAR has been used to study the relationships between the antifungal activity and lipophilicity parameter, logP, calculated by using CS Chem-Office Software version 7.0. The results are discussed on the basis of statistical data. The best QSAR model for prediction of antifungal activity of the investigated series of benzimidazoles was developed. High agreement between experimental and predicted inhibitory values was obtained. The results of this study indicate that the lipophilicity parameter has a significant effect on antifungal activity of this class of compounds, which simplify design of new biologically active molecules.

  9. A Test of the Active-Day Fraction Method of Sunspot Group Number Calibration: Dependence on the Level of Solar Activity

    Science.gov (United States)

    Willamo, T.; Usoskin, I. G.; Kovaltsov, G. A.

    2018-04-01

    The method of active-day fraction (ADF) was proposed recently to calibrate different solar observers to standard observational conditions. The result of the calibration may depend on the overall level of solar activity during the observational period. This dependency is studied quantitatively using data of the Royal Greenwich Observatory by formally calibrating synthetic pseudo-observers to the full reference dataset. It is shown that the sunspot group number is precisely estimated by the ADF method for periods of moderate activity, may be slightly underestimated by 0.5 - 1.5 groups ({≤} 10%) for strong and very strong activity, and is strongly overestimated by up to 2.5 groups ({≤} 30%) for weak-to-moderate activity. The ADF method becomes inapplicable for the periods of grand minima of activity. In general, the ADF method tends to overestimate the overall level of activity and to reduce the long-term trends.

  10. Time-Dependent Changes in T1 during Fracture Healing in Juvenile Rats: A Quantitative MR Approach.

    Directory of Open Access Journals (Sweden)

    Katharina Baron

    Full Text Available Quantitative magnetic resonance imaging (qMRI offers several advantages in imaging and determination of soft tissue alterations when compared to qualitative imaging techniques. Although applications in brain and muscle tissues are well studied, its suitability to quantify relaxation times of intact and injured bone tissue, especially in children, is widely unknown. The objective observation of a fracture including its age determination can become of legal interest in cases of child abuse or maltreatment. Therefore, the aim of this study is the determination of time dependent changes in intact and corresponding injured bones in immature rats via qMRI, to provide the basis for an objective and radiation-free approach for fracture dating. Thirty-five MR scans of 7 Sprague-Dawley rats (male, 4 weeks old, 100 ± 5 g were acquired on a 3T MRI scanner (TimTrio, Siemens AG, Erlangen, Germany after the surgical infliction of an epiphyseal fracture in the tibia. The images were taken at days 1, 3, 7, 14, 28, 42 and 82 post-surgery. A proton density-weighted and a T1-weighted 3D FLASH sequence were acquired to calculate the longitudinal relaxation time T1 of the fractured region and the surrounding tissues. The calculation of T1 in intact and injured bone resulted in a quantitative observation of bone development in intact juvenile tibiae as well as the bone healing process in the injured tibiae. In both areas, T1 decreased over time. To evaluate the differences in T1 behaviour between the intact and injured bone, the relative T1 values (bone-fracture were calculated, showing clear detectable alterations of T1 after fracture occurrence. These results indicate that qMRI has a high potential not only for clinically relevant applications to detect growth defects or developmental alterations in juvenile bones, but also for forensically relevant applications such as the dating of fractures in cases of child abuse or maltreatment.

  11. Quantitative and qualitative analysis of telomerase activity in benign and malignant thyroid tissues

    International Nuclear Information System (INIS)

    Zheng Rongxiu; Fang Peihua; Tan Jian; Lu Mei; Li Yigong

    2002-01-01

    Objective: To study the status of telomerase activity during the development of thyroid tumors, and to determine whether telomerase activity can be used clinically as a molecular marker in the differential diagnosis of thyroid cancer. Methods: Telomerase activity was measured in 37 thyroid carcinomas, 33 benign thyroid lesions and 30 normal thyroid tissue samples by means of a modified TRAP-PCR. The assay was also applied to 15 fine needle aspirates (FNAs) of thyroid carcinomas to test its sensitivity. Results: Thirty-one of 37 thyroid carcinomas (83.8%), 7 of 33 benign thyroid lesions (21.2%), and 4 of 30 adjacent normal thyroid tissue samples expressed telomerase activity, 15 FNAs also had positive telomerase activity, just as their corresponding tissue specimens. The quantitative analysis showed that the telomerase activity was significantly higher in thyroid carcinomas than that in benign thyroid tissue samples. And medullary carcinomas and anaplastic carcinomas had higher levels of telomerase activity than papillary carcinomas. Conclusions: Telomerase activity is a good marker for thyroid carcinomas. The quantitative TRAP-PCR might have more potential application in the differential diagnosis of tumors and the estimation of tumor progression and prognosis. And this sensitive assay could become a useful new modality for supplementing microscopic cytopathology in the detection of cancer cells in small tissue samples and FNAs

  12. Calculation of Quantitative Structure-Activity Relationship Descriptors of Artemisinin Derivatives

    Directory of Open Access Journals (Sweden)

    Jambalsuren Bayarmaa

    2008-06-01

    Full Text Available Quantitative structure-activity relationships are based on the construction of predictive models using a set of known molecules and associated activity value. This accurate methodology, developed with adequate mathematical and computational tools, leads to a faster, cheaper and more comprehensive design of new products, reducing the experimental synthesis and testing on animals. Preparation of the QSAR models of artemisinin derivatives was carried out by the genetic function algorithm (GFA method for 91 molecules. The results show some relationships to the observed antimalarial activities of the artemisinin derivatives. The most statistically signi fi cant regression equation obtained from the fi nal GFA relates to two molecular descriptors.

  13. Afferent activity to necklace glomeruli is dependent on external stimuli

    Directory of Open Access Journals (Sweden)

    Munger Steven D

    2009-03-01

    Full Text Available Abstract Background The main olfactory epithelium (MOE is a complex organ containing several functionally distinct subpopulations of sensory neurons. One such subpopulation is distinguished by its expression of the guanylyl cyclase GC-D. The axons of GC-D-expressing (GC-D+ neurons innervate 9–15 "necklace" glomeruli encircling the caudal main olfactory bulb (MOB. Chemosensory stimuli for GC-D+ neurons include two natriuretic peptides, uroguanylin and guanylin, and CO2. However, the biologically-relevant source of these chemostimuli is unclear: uroguanylin is both excreted in urine, a rich source of olfactory stimuli for rodents, and expressed in human nasal epithelium; CO2 is present in both inspired and expired air. Findings To determine whether the principal source of chemostimuli for GC-D+ neurons is external or internal to the nose, we assessed the consequences of removing external chemostimuli for afferent activity to the necklace glomeruli. To do so, we performed unilateral naris occlusions in Gucy2d-Mapt-lacZ +/- mice [which express a β-galactosidase (β-gal reporter specifically in GC-D+ neurons] followed by immunohistochemistry for β-gal and a glomerular marker of afferent activity, tyrosine hydroxylase (TH. We observed a dramatic decrease in TH immunostaining, consistent with reduced or absent afferent activity, in both necklace and non-necklace glomeruli ipsilateral to the occluded naris. Conclusion Like other MOB glomeruli, necklace glomeruli exhibit a large decrease in afferent activity upon removal of external stimuli. Thus, we conclude that activity in GC-D+ neurons, which specifically innervate necklace glomeruli, is not dependent on internal stimuli. Instead, GC-D+ neurons, like other OSNs in the MOE, primarily sense the external world.

  14. Sex-dependent differences in voluntary physical activity.

    Science.gov (United States)

    Rosenfeld, Cheryl S

    2017-01-02

    Numbers of overweight and obese individuals are increasing in the United States and globally, and, correspondingly, the associated health care costs are rising dramatically. More than one-third of children are currently considered obese with a predisposition to type 2 diabetes, and it is likely that their metabolic conditions will worsen with age. Physical inactivity has also risen to be the leading cause of many chronic, noncommunicable diseases (NCD). Children are more physically inactive now than they were in past decades, which may be due to intrinsic and extrinsic factors. In rodents, the amount of time engaged in spontaneous activity within the home cage is a strong predictor of later adiposity and weight gain. Thus, it is important to understand primary motivators stimulating physical activity (PA). There are normal sex differences in PA levels in rodents and humans. The perinatal environment can induce sex-dependent differences in PA disturbances. This Review considers the current evidence for sex differences in PA in rodents and humans. The rodent studies showing that early exposure to environmental chemicals can shape later adult PA responses are discussed. Next, whether there are different motivators stimulating exercise in male vs. female humans are examined. Finally, the brain regions, genes, and pathways that modulate PA in rodents, and possibly by translation in humans, are described. A better understanding of why each sex remains physically active through the life span could open new avenues for preventing and treating obesity in children and adults. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  15. The Application of the Photographic Plate to the Quantitative Determination of Activities by Track Counts

    Energy Technology Data Exchange (ETDEWEB)

    Broda, E.

    1946-07-01

    This report was written by E. Broda at the Cavendish Laboratory (Cambridge) in August 1946 and is about the application of the photographic plate to the quantitative determination of activities by track counts. This report includes the experiment description and the discussion of the results and consists of 4 parts: 1) Introduction 2) Estimation of Concentrations 3) The uptake of U in different conditions 4) The upper limits of the fission Cross sections of Bi and Pb. (nowak)

  16. The Application of the Photographic Plate to the Quantitative Determination of Activities by Track Counts

    International Nuclear Information System (INIS)

    Broda, E.

    1946-01-01

    This report was written by E. Broda at the Cavendish Laboratory (Cambridge) in August 1946 and is about the application of the photographic plate to the quantitative determination of activities by track counts. This report includes the experiment description and the discussion of the results and consists of 4 parts: 1) Introduction 2) Estimation of Concentrations 3) The uptake of U in different conditions 4) The upper limits of the fission Cross sections of Bi and Pb. (nowak)

  17. Are quantitative trait-dependent sampling designs cost-effective for analysis of rare and common variants?

    Science.gov (United States)

    Yilmaz, Yildiz E; Bull, Shelley B

    2011-11-29

    Use of trait-dependent sampling designs in whole-genome association studies of sequence data can reduce total sequencing costs with modest losses of statistical efficiency. In a quantitative trait (QT) analysis of data from the Genetic Analysis Workshop 17 mini-exome for unrelated individuals in the Asian subpopulation, we investigate alternative designs that sequence only 50% of the entire cohort. In addition to a simple random sampling design, we consider extreme-phenotype designs that are of increasing interest in genetic association analysis of QTs, especially in studies concerned with the detection of rare genetic variants. We also evaluate a novel sampling design in which all individuals have a nonzero probability of being selected into the sample but in which individuals with extreme phenotypes have a proportionately larger probability. We take differential sampling of individuals with informative trait values into account by inverse probability weighting using standard survey methods which thus generalizes to the source population. In replicate 1 data, we applied the designs in association analysis of Q1 with both rare and common variants in the FLT1 gene, based on knowledge of the generating model. Using all 200 replicate data sets, we similarly analyzed Q1 and Q4 (which is known to be free of association with FLT1) to evaluate relative efficiency, type I error, and power. Simulation study results suggest that the QT-dependent selection designs generally yield greater than 50% relative efficiency compared to using the entire cohort, implying cost-effectiveness of 50% sample selection and worthwhile reduction of sequencing costs.

  18. Effects of Ayahuasca and its Alkaloids on Drug Dependence: A Systematic Literature Review of Quantitative Studies in Animals and Humans.

    Science.gov (United States)

    Nunes, Amanda A; Dos Santos, Rafael G; Osório, Flávia L; Sanches, Rafael F; Crippa, José Alexandre S; Hallak, Jaime E C

    2016-01-01

    Recently, the anti-addictive potential of ayahuasca, a dimethyltryptamine(DMT)- and β-carboline-rich hallucinogenic beverage traditionally used by indigenous groups of the Northwest Amazon and currently by syncretic churches worldwide, has received increased attention. To better evaluate this topic, we performed a systematic literature review using the PubMed database to find quantitative studies (using statistical analysis) that assessed the effects of ayahuasca or its components in drug-related symptoms or disorders. We found five animal studies (using harmaline, harmine, or ayahuasca) and five observational studies of regular ayahuasca consumers. All animal studies showed improvement of biochemical or behavioral parameters related to drug-induced disorders. Of the five human studies, four reported significant reductions of dependence symptoms or substance use, while one did not report significant results. The mechanisms responsible for the anti-addictive properties of ayahuasca and its alkaloids are not clarified, apparently involving both peripheral MAO-A inhibition by the β-carbolines and central agonism of DMT at 5-HT2A receptors expressed in brain regions related to the regulation of mood and emotions. Although results are promising, controlled studies are needed to replicate these preliminary findings.

  19. Opioid-Induced Glial Activation: Mechanisms of Activation and Implications for Opioid Analgesia, Dependence, and Reward

    Directory of Open Access Journals (Sweden)

    Mark R. Hutchinson

    2007-01-01

    Full Text Available This review will introduce the concept of toll-like receptor (TLR–mediated glial activation as central to all of the following: neuropathic pain, compromised acute opioid analgesia, and unwanted opioid side effects (tolerance, dependence, and reward. Attenuation of glial activation has previously been demonstrated both to alleviate exaggerated pain states induced by experimental pain models and to reduce the development of opioid tolerance. Here we demonstrate that selective acute antagonism of TLR4 results in reversal of neuropathic pain as well as potentiation of opioid analgesia. Attenuating central nervous system glial activation was also found to reduce the development of opioid dependence, and opioid reward at a behavioral (conditioned place preference and neurochemical (nucleus accumbens microdialysis of morphine-induced elevations in dopamine level of analysis. Moreover, a novel antagonism of TLR4 by (+- and (˗-isomer opioid antagonists has now been characterized, and both antiallodynic and morphine analgesia potentiating activity shown. Opioid agonists were found to also possess TLR4 agonistic activity, predictive of glial activation. Targeting glial activation is a novel and as yet clinically unexploited method for treatment of neuropathic pain. Moreover, these data indicate that attenuation of glial activation, by general or selective TLR antagonistic mechanisms, may also be a clinical method for separating the beneficial (analgesia and unwanted (tolerance, dependence, and reward actions of opioids, thereby improving the safety and efficacy of their use.

  20. Finding Biomass Degrading Enzymes Through an Activity-Correlated Quantitative Proteomics Platform (ACPP)

    Science.gov (United States)

    Ma, Hongyan; Delafield, Daniel G.; Wang, Zhe; You, Jianlan; Wu, Si

    2017-04-01

    The microbial secretome, known as a pool of biomass (i.e., plant-based materials) degrading enzymes, can be utilized to discover industrial enzyme candidates for biofuel production. Proteomics approaches have been applied to discover novel enzyme candidates through comparing protein expression profiles with enzyme activity of the whole secretome under different growth conditions. However, the activity measurement of each enzyme candidate is needed for confident "active" enzyme assignments, which remains to be elucidated. To address this challenge, we have developed an Activity-Correlated Quantitative Proteomics Platform (ACPP) that systematically correlates protein-level enzymatic activity patterns and protein elution profiles using a label-free quantitative proteomics approach. The ACPP optimized a high performance anion exchange separation for efficiently fractionating complex protein samples while preserving enzymatic activities. The detected enzymatic activity patterns in sequential fractions using microplate-based assays were cross-correlated with protein elution profiles using a customized pattern-matching algorithm with a correlation R-score. The ACPP has been successfully applied to the identification of two types of "active" biomass-degrading enzymes (i.e., starch hydrolysis enzymes and cellulose hydrolysis enzymes) from Aspergillus niger secretome in a multiplexed fashion. By determining protein elution profiles of 156 proteins in A. niger secretome, we confidently identified the 1,4-α-glucosidase as the major "active" starch hydrolysis enzyme (R = 0.96) and the endoglucanase as the major "active" cellulose hydrolysis enzyme (R = 0.97). The results demonstrated that the ACPP facilitated the discovery of bioactive enzymes from complex protein samples in a high-throughput, multiplexing, and untargeted fashion.

  1. The formation of insoluble Tc depends on bacterial activity

    International Nuclear Information System (INIS)

    Ishii, Nobuyoshi; Uchida, Shigeo; Koiso, Hiroyuki

    2005-01-01

    The formation of insoluble Tc (>0.2 μm in size) in ponding water of paddy soil was investigated. The ponding water prepared by flooding with deionized water was collected at a one-week intervals during the 120 days of the experimental period. The collected sample was incubated with 3 kBq mL -1 TcO 4 - at 25degC for 14 days. The mean value of relative amounts of insolubilized Tc was less than 0.6% of total Tc. This result suggested that flooding with deionized water was not effective for the formation of insoluble Tc. When the ponding water sample was incubated with TcO 4 - under anaerobic conditions, Tc was scarcely insolubilized. On the other hand, a significant fraction of the Tc was insolubilized in the ponding water sample supplemented with nutrients that promote bacterial activity. Also, the amount of insoluble Tc increased with time. From these results, it was concluded that the formation of insoluble Tc in the ponding water depends on enhanced bacterial activity rather than just anaerobic conditions. (author)

  2. Glutathionylation regulates cytosolic NADP+-dependent isocitrate dehydrogenase activity.

    Science.gov (United States)

    Shin, Seoung Woo; Oh, Chang Joo; Kil, In Sup; Park, Jeen-Woo

    2009-04-01

    Cytosolic NADP+-dependent isocitrate dehydrogenase (IDPc) is susceptible to inactivation by numerous thiol-modifying reagents. This study now reports that Cys269 of IDPc is a target for S-glutathionylation and that this modification is reversed by dithiothreitol as well as enzymatically by cytosolic glutaredoxin in the presence of GSH. Glutathionylated IDPc was significantly less susceptible than native protein to peptide fragmentation by reactive oxygen species and proteolytic digestion. Glutathionylation may play a protective role in the degradation of protein through the structural alterations of IDPc. HEK293 cells treated with diamide displayed decreased IDPc activity and accumulated glutathionylated enzyme. Using immunoprecipitation with an anti-IDPc IgG and immunoblotting with an anti-GSH IgG, we purified and positively identified glutathionylated IDPc from the kidneys of mice subjected to ischemia/reperfusion injury and from the livers of ethanol-administered rats. These results suggest that IDPc activity is modulated through enzymatic glutathionylation and deglutathionylation during oxidative stress.

  3. Comparison of conventional, model-based quantitative planar, and quantitative SPECT image processing methods for organ activity estimation using In-111 agents

    International Nuclear Information System (INIS)

    He, Bin; Frey, Eric C

    2006-01-01

    Accurate quantification of organ radionuclide uptake is important for patient-specific dosimetry. The quantitative accuracy from conventional conjugate view methods is limited by overlap of projections from different organs and background activity, and attenuation and scatter. In this work, we propose and validate a quantitative planar (QPlanar) processing method based on maximum likelihood (ML) estimation of organ activities using 3D organ VOIs and a projector that models the image degrading effects. Both a physical phantom experiment and Monte Carlo simulation (MCS) studies were used to evaluate the new method. In these studies, the accuracies and precisions of organ activity estimates for the QPlanar method were compared with those from conventional planar (CPlanar) processing methods with various corrections for scatter, attenuation and organ overlap, and a quantitative SPECT (QSPECT) processing method. Experimental planar and SPECT projections and registered CT data from an RSD Torso phantom were obtained using a GE Millenium VH/Hawkeye system. The MCS data were obtained from the 3D NCAT phantom with organ activity distributions that modelled the uptake of 111 In ibritumomab tiuxetan. The simulations were performed using parameters appropriate for the same system used in the RSD torso phantom experiment. The organ activity estimates obtained from the CPlanar, QPlanar and QSPECT methods from both experiments were compared. From the results of the MCS experiment, even with ideal organ overlap correction and background subtraction, CPlanar methods provided limited quantitative accuracy. The QPlanar method with accurate modelling of the physical factors increased the quantitative accuracy at the cost of requiring estimates of the organ VOIs in 3D. The accuracy of QPlanar approached that of QSPECT, but required much less acquisition and computation time. Similar results were obtained from the physical phantom experiment. We conclude that the QPlanar method, based

  4. Quantitative structure activity relationship (QSAR) of piperine analogs for bacterial NorA efflux pump inhibitors.

    Science.gov (United States)

    Nargotra, Amit; Sharma, Sujata; Koul, Jawahir Lal; Sangwan, Pyare Lal; Khan, Inshad Ali; Kumar, Ashwani; Taneja, Subhash Chander; Koul, Surrinder

    2009-10-01

    Quantitative structure activity relationship (QSAR) analysis of piperine analogs as inhibitors of efflux pump NorA from Staphylococcus aureus has been performed in order to obtain a highly accurate model enabling prediction of inhibition of S. aureus NorA of new chemical entities from natural sources as well as synthetic ones. Algorithm based on genetic function approximation method of variable selection in Cerius2 was used to generate the model. Among several types of descriptors viz., topological, spatial, thermodynamic, information content and E-state indices that were considered in generating the QSAR model, three descriptors such as partial negative surface area of the compounds, area of the molecular shadow in the XZ plane and heat of formation of the molecules resulted in a statistically significant model with r(2)=0.962 and cross-validation parameter q(2)=0.917. The validation of the QSAR models was done by cross-validation, leave-25%-out and external test set prediction. The theoretical approach indicates that the increase in the exposed partial negative surface area increases the inhibitory activity of the compound against NorA whereas the area of the molecular shadow in the XZ plane is inversely proportional to the inhibitory activity. This model also explains the relationship of the heat of formation of the compound with the inhibitory activity. The model is not only able to predict the activity of new compounds but also explains the important regions in the molecules in quantitative manner.

  5. Telomerase Activity Detected by Quantitative Assay in Bladder Carcinoma and Exfoliated Cells in Urine

    Directory of Open Access Journals (Sweden)

    Roberta Fedriga

    2001-01-01

    Full Text Available Early diagnosis is one of the most determining factors for patient survival. The detection of telomerase activity is a potentially promising tool in the diagnosis of bladder and other types of cancer due to the high expression of this enzyme in tumor cells. We carried out a quantitative evaluation of telomerase activity in urine samples in an attempt to determine a cut-off capable of identifying cancer patients. Telomerase activity was quantified by fluorescence TRAP assay in urine from 50 healthy volunteers and in urine and bioptic tumor samples from 56 previously untreated bladder cancer patients and expressed in arbitrary enzymatic units (AEU. Telomerase activity in urine ranged from 0 to 106 AEU (median 0 in healthy donors and from 0 to 282 AEU (median 87 in patients with cancer. A telomerase expression higher than the cut off value determined by receiver operating characteristic (ROC analysis was observed in 78% of cases, regardless of tumor grade and in 71% (15/21 of cases of nonassessable or negative cytology. The quantitative analysis of telomerase activity in urine enabled us to define cut-off values characterized by different sensitivity and specificity. Cytologic and telomerase determination, used sequentially, enabled us to detect about 90% of tumors.

  6. The mass dependence of chromospheric activity evolution & implications for gyrochronology

    Science.gov (United States)

    Curtis, Jason

    2018-01-01

    We know chromospheric emission decays over time, and yet this empirical relation is still fundamentally an interpolation over 3.5 Gyr from the Hyades to the Sun despite 45 years of progress. Furthermore, its very existence was called into question by Pace et al. (2004, 2009, 2013), who argued that activity plummets and flatlines around 1-2 Gyr. I will present new Ca II H & K data for NGC 752 (1.5 Gyr) and Ruprecht 147 (3 Gyr), and ISM-corrected data for M67 (4 Gyr, Curtis 2017), and pair this with the Sun's re-calibrated history (Egeland et al. 2017) and data on field stars from the Keck exoplanet program. I calculated ages for the field star sample using the [Y/Mg] "chemical clock," which was discovered from studies of solar twins and is due to galactic chemical enrichment. I find a mass dependence that matches the prediction from the activity-rotation-age relation of Mamajek & Hillenbrand (2008), where F stars rapidly plummet at 1-2 Gyr in line with the observations of F stars in clusters of similar age by Pace et al., whereas activity continuously declines for G and K dwarfs to approximately 5 and 7 Gyr, respectively. I will show that comparing ages estimated from [Y/Mg] to activity--rotation ages reveals known hot Jupiter hosts and other potentially anomalous stars. Combining the empirical relation between activity and Rossby number with estimates of stellar mass from spectroscopy and age from [Y/Mg] yields a gyrochronology relationship for FG and early K dwarfs that is independent of the cluster age scale and appears consistent with models from Mamajek & Hillenbrand (2008) and Barnes (2010). However, I have separately measured rotation periods for mid to late K dwarfs in 3 Gyr Ruprecht 147 with K2 and I find that they are rotating too rapidly relative to these empirical models and the semi-physical model of Matt et al. (2015). Apparently, K dwarfs spin down more slowly than the Skumanich square-root Law. Determining the K dwarf spin-down law is critical for

  7. Dependency of cardiac rubidium-82 imaging quantitative measures on age, gender, vascular territory, and software in a cardiovascular normal population.

    Science.gov (United States)

    Sunderland, John J; Pan, Xiao-Bo; Declerck, Jerome; Menda, Yusuf

    2015-02-01

    Recent technological improvements to PET imaging equipment combined with the availability of software optimized to calculate regional myocardial blood flow (MBF) and myocardial flow reserve (MFR) create a paradigm shifting opportunity to provide new clinically relevant quantitative information to cardiologists. However, clinical interpretation of the MBF and MFR is entirely dependent upon knowledge of MBF and MFR values in normal populations and subpopulations. This work reports Rb-82-based MBF and MFR measurements for a series of 49 verified cardiovascularly normal subjects as a preliminary baseline for future clinical studies. Forty-nine subjects (24F/25M, ages 41-69) with low probability for coronary artery disease and with normal exercise stress test were included. These subjects underwent rest/dipyridamole stress Rb-82 myocardial perfusion imaging using standard clinical techniques (40 mCi injection, 6-minute acquisition) using a Siemens Biograph 40 PET/CT scanner with high count rate detector option. List mode data was rehistogrammed into 26 dynamic frames (12 × 5 seconds, 6 × 10 seconds, 4 × 20 seconds, 4 × 40 seconds). Cardiac images were processed, and MBF and MFR calculated using Siemens syngo MBF, PMOD, and FlowQuant software using a single compartment Rb-82 model. Global myocardial blood flow under pharmacological stress for the 24 females as measured by PMOD, syngo MBF, and FlowQuant were 3.10 ± 0.72, 2.80 ± 0.66, and 2.60 ± 0.63 mL·minute(-1)·g(-1), and for the 25 males was 2.60 ± 0.84, 2.33 ± 0.75, 2.15 ± 0.62 mL·minute(-1)·g(-1), respectively. Rest flows for PMOD, syngo MBF, and FlowQuant averaged 1.32 ± 0.42, 1.20 ± 0.33, and 1.06 ± 0.38 mL·minute(-1)·g(-1) for the female subjects, and 1.12 ± 0.29, 0.90 ± 0.26, and 0.85 ± 0.24 mL·minute(-1)·g(-1) for the males. Myocardial flow reserves for PMOD, syngo MBF, and FlowQuant for the female normals were calculated to be 2.50 ± 0.80, 2.53 ± 0.67, 2.71 ± 0.90, and 2.50 ± 1.19, 2

  8. Cre-dependent DNA recombination activates a STING-dependent innate immune response

    Science.gov (United States)

    Pépin, Geneviève; Ferrand, Jonathan; Höning, Klara; Jayasekara, W. Samantha N.; Cain, Jason E.; Behlke, Mark A.; Gough, Daniel J.; G. Williams, Bryan R.; Hornung, Veit

    2016-01-01

    Abstract Gene-recombinase technologies, such as Cre/loxP-mediated DNA recombination, are important tools in the study of gene function, but have potential side effects due to damaging activity on DNA. Here we show that DNA recombination by Cre instigates a robust antiviral response in mammalian cells, independent of legitimate loxP recombination. This is due to the recruitment of the cytosolic DNA sensor STING, concurrent with Cre-dependent DNA damage and the accumulation of cytoplasmic DNA. Importantly, we establish a direct interplay between this antiviral response and cell–cell interactions, indicating that low cell densities in vitro could be useful to help mitigate these effects of Cre. Taking into account the wide range of interferon stimulated genes that may be induced by the STING pathway, these results have broad implications in fields such as immunology, cancer biology, metabolism and stem cell research. Further, this study sets a precedent in the field of gene-engineering, possibly applicable to other enzymatic-based genome editing technologies. PMID:27166376

  9. Making College Count: An Examination of Quantitative Reasoning Activities in Higher Education

    Directory of Open Access Journals (Sweden)

    Louis M. Rocconi

    2013-07-01

    Full Text Available Findings from national studies along with more frequent calls from those who employ college graduates suggest an urgent need for colleges and universities to increase opportunities for students to develop quantitative reasoning (QR skills. To address this issue, the current study examines the relationship between the frequency of QR activities during college and student and institutional characteristics, as well as whether students at institutions with an emphasis on QR (at least one QR course requirement for all students report more QR activity. Results show that gender, race-ethnicity, major, full-time status, first-generation status, age, institutional enrollment size, and institutional control are related to the frequency of QR activities. Findings also suggest that such activities are indeed more common among institutions that emphasize QR.

  10. Microfluorometric mithramycin assay for quantitating the effects of immunotoxicants on lymphocyte activation

    International Nuclear Information System (INIS)

    Quattrone, A.J.; Ranney, D.F.

    1981-01-01

    A semiautomated, microfluorometric assay has been developed for the detection of toxicant-induced changes in lymphocyte DNA content at standard intervals after mitogen activation. DNA is quantitated by solubilizing the cells and determining the fluorescence enhancement that results from formation of the highly specific mithramycin:DNA adduct. The limit of detection is 0.21 μg (30,000 resting cell equivalents) per microliter well. Correlation with the less sensitive, nonautomatable, diphenylamine DNA assay give a correlation coefficient r = 0.91. Prototype substances representative of true immunotoxicants (prostaglandin E 2 ) and common interfering substances (thymidine at 14 M) have been tested. The latter substance produces false positive results in the standard [ 3 H] thymidine assay. The mithramycin assay does not inappropriately detect this interfering substance. It has the characteristics of a highly specific, accurate technique of screening and quantitating immunotoxic drugs, agents, and mediators in patient sera and other complex biological fluids

  11. Abscisic acid-dependent multisite phosphorylation regulates the activity of a transcription activator AREB1.

    Science.gov (United States)

    Furihata, Takashi; Maruyama, Kyonoshin; Fujita, Yasunari; Umezawa, Taishi; Yoshida, Riichiro; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

    2006-02-07

    bZIP-type transcription factors AREBs/ABFs bind an abscisic acid (ABA)-responsive cis-acting element named ABRE and transactivate downstream gene expression in Arabidopsis. Because AREB1 overexpression could not induce downstream gene expression, activation of AREB1 requires ABA-dependent posttranscriptional modification. We confirmed that ABA activated 42-kDa kinase activity, which, in turn, phosphorylated Ser/Thr residues of R-X-X-S/T sites in the conserved regions of AREB1. Amino acid substitutions of R-X-X-S/T sites to Ala suppressed transactivation activity, and multiple substitution of these sites resulted in almost complete suppression of transactivation activity in transient assays. In contrast, substitution of the Ser/Thr residues to Asp resulted in high transactivation activity without exogenous ABA application. A phosphorylated, transcriptionally active form was achieved by substitution of Ser/Thr in all conserved R-X-X-S/T sites to Asp. Transgenic plants overexpressing the phosphorylated active form of AREB1 expressed many ABA-inducible genes, such as RD29B, without ABA treatment. These results indicate that the ABA-dependent multisite phosphorylation of AREB1 regulates its own activation in plants.

  12. Activity-dependent neurorehabilitation beyond physical trainings: "mental exercise" through mirror neuron activation

    OpenAIRE

    Yuan, Ti-Fei; Chen, Wei; Shan, Chunlei; Rocha, Nuno; Arias-Carrión, Oscar; Paes, Flávia; de Sa, Alberto Souza; Machado, Sergio

    2015-01-01

    The activity dependent brain repair mechanism has been widely adopted in many types of neurorehabilitation. The activity leads to target specific and non-specific beneficial effects in different brain regions, such as the releasing of neurotrophic factors, modulation of the cytokines and generation of new neurons in adult hood. However physical exercise program clinically are limited to some of the patients with preserved motor functions; while many patients suffered from paralysis cannot mak...

  13. Biochemical quantitation of the eIF5A hypusination in Arabidopsis thaliana uncovers ABA-dependent regulation

    Science.gov (United States)

    Belda-Palazón, Borja; Nohales, María A.; Rambla, José L.; Aceña, José L.; Delgado, Oscar; Fustero, Santos; Martínez, M. Carmen; Granell, Antonio; Carbonell, Juan; Ferrando, Alejandro

    2014-01-01

    The eukaryotic translation elongation factor eIF5A is the only protein known to contain the unusual amino acid hypusine which is essential for its biological activity. This post-translational modification is achieved by the sequential action of the enzymes deoxyhypusine synthase (DHS) and deoxyhypusine hydroxylase (DOHH). The crucial molecular function of eIF5A during translation has been recently elucidated in yeast and it is expected to be fully conserved in every eukaryotic cell, however the functional description of this pathway in plants is still sparse. The genetic approaches with transgenic plants for either eIF5A overexpression or antisense have revealed some activities related to the control of cell death processes but the molecular details remain to be characterized. One important aspect of fully understanding this pathway is the biochemical description of the hypusine modification system. Here we have used recombinant eIF5A proteins either modified by hypusination or non-modified to establish a bi-dimensional electrophoresis (2D-E) profile for the three eIF5A protein isoforms and their hypusinated or unmodified proteoforms present in Arabidopsis thaliana. The combined use of the recombinant 2D-E profile together with 2D-E/western blot analysis from whole plant extracts has provided a quantitative approach to measure the hypusination status of eIF5A. We have used this information to demonstrate that treatment with the hormone abscisic acid produces an alteration of the hypusine modification system in Arabidopsis thaliana. Overall this study presents the first biochemical description of the post-translational modification of eIF5A by hypusination which will be functionally relevant for future studies related to the characterization of this pathway in Arabidopsis thaliana. PMID:24904603

  14. Hepatitis C virus translation preferentially depends on active RNA replication.

    Directory of Open Access Journals (Sweden)

    Helene Minyi Liu

    Full Text Available Hepatitis C virus (HCV RNA initiates its replication on a detergent-resistant membrane structure derived from the endoplasmic reticulum (ER in the HCV replicon cells. By performing a pulse-chase study of BrU-labeled HCV RNA, we found that the newly-synthesized HCV RNA traveled along the anterograde-membrane traffic and moved away from the ER. Presumably, the RNA moved to the site of translation or virion assembly in the later steps of viral life cycle. In this study, we further addressed how HCV RNA translation was regulated by HCV RNA trafficking. When the movement of HCV RNA from the site of RNA synthesis to the Golgi complex was blocked by nocodazole, an inhibitor of ER-Golgi transport, HCV protein translation was surprisingly enhanced, suggesting that the translation of viral proteins occurred near the site of RNA synthesis. We also found that the translation of HCV proteins was dependent on active RNA synthesis: inhibition of viral RNA synthesis by an NS5B inhibitor resulted in decreased HCV viral protein synthesis even when the total amount of intracellular HCV RNA remained unchanged. Furthermore, the translation activity of the replication-defective HCV replicons or viral RNA with an NS5B mutation was greatly reduced as compared to that of the corresponding wildtype RNA. By performing live cell labeling of newly synthesized HCV RNA and proteins, we further showed that the newly synthesized HCV proteins colocalized with the newly synthesized viral RNA, suggesting that HCV RNA replication and protein translation take place at or near the same site. Our findings together indicate that the translation of HCV RNA is coupled to RNA replication and that the both processes may occur at the same subcellular membrane compartments, which we term the replicasome.

  15. NK cell receptor/H2-Dk-dependent host resistance to viral infection is quantitatively modulated by H2q inhibitory signals.

    Science.gov (United States)

    Fodil-Cornu, Nassima; Loredo-Osti, J Concepción; Vidal, Silvia M

    2011-04-01

    The cytomegalovirus resistance locus Cmv3 has been linked to an epistatic interaction between two loci: a Natural Killer (NK) cell receptor gene and the major histocompatibility complex class I (MHC-I) locus. To demonstrate the interaction between Cmv3 and H2(k), we generated double congenic mice between MA/My and BALB.K mice and an F(2) cross between FVB/N (H-2(q)) and BALB.K (H2(k)) mice, two strains susceptible to mouse cytomegalovirus (MCMV). Only mice expressing H2(k) in conjunction with Cmv3(MA/My) or Cmv3(FVB) were resistant to MCMV infection. Subsequently, an F(3) cross was carried out between transgenic FVB/H2-D(k) and MHC-I deficient mice in which only the progeny expressing Cmv3(FVB) and a single H2-D(k) class-I molecule completely controlled MCMV viral loads. This phenotype was shown to be NK cell-dependent and associated with subsequent NK cell proliferation. Finally, we demonstrated that a number of H2(q) alleles influence the expression level of H2(q) molecules, but not intrinsic functional properties of NK cells; viral loads, however, were quantitatively proportional to the number of H2(q) alleles. Our results support a model in which H-2(q) molecules convey Ly49-dependent inhibitory signals that interfere with the action of H2-D(k) on NK cell activation against MCMV infection. Thus, the integration of activating and inhibitory signals emanating from various MHC-I/NK cell receptor interactions regulates NK cell-mediated control of viral load.

  16. NK Cell Receptor/H2-Dk–Dependent Host Resistance to Viral Infection Is Quantitatively Modulated by H2 q Inhibitory Signals

    Science.gov (United States)

    Fodil-Cornu, Nassima; Loredo-Osti, J. Concepción; Vidal, Silvia M.

    2011-01-01

    The cytomegalovirus resistance locus Cmv3 has been linked to an epistatic interaction between two loci: a Natural Killer (NK) cell receptor gene and the major histocompatibility complex class I (MHC-I) locus. To demonstrate the interaction between Cmv3 and H2k, we generated double congenic mice between MA/My and BALB.K mice and an F2 cross between FVB/N (H-2q) and BALB.K (H2k) mice, two strains susceptible to mouse cytomegalovirus (MCMV). Only mice expressing H2k in conjunction with Cmv3MA/My or Cmv3FVB were resistant to MCMV infection. Subsequently, an F3 cross was carried out between transgenic FVB/H2-Dk and MHC-I deficient mice in which only the progeny expressing Cmv3FVB and a single H2-Dk class-I molecule completely controlled MCMV viral loads. This phenotype was shown to be NK cell–dependent and associated with subsequent NK cell proliferation. Finally, we demonstrated that a number of H2q alleles influence the expression level of H2q molecules, but not intrinsic functional properties of NK cells; viral loads, however, were quantitatively proportional to the number of H2q alleles. Our results support a model in which H-2q molecules convey Ly49-dependent inhibitory signals that interfere with the action of H2-Dk on NK cell activation against MCMV infection. Thus, the integration of activating and inhibitory signals emanating from various MHC-I/NK cell receptor interactions regulates NK cell–mediated control of viral load. PMID:21533075

  17. Selective functional activity measurement of a PEGylated protein with a modification-dependent activity assay.

    Science.gov (United States)

    Weber, Alfred; Engelmaier, Andrea; Mohr, Gabriele; Haindl, Sonja; Schwarz, Hans Peter; Turecek, Peter L

    2017-01-05

    BAX 855 (ADYNOVATE) is a PEGylated recombinant factor VIII (rFVIII) that showed prolonged circulatory half-life compared to unmodified rFVIII in hemophilic patients. Here, the development and validation of a novel assay is described that selectively measures the activity of BAX 855 as cofactor for the serine protease factor IX, which actives factor X. This method type, termed modification-dependent activity assay, is based on PEG-specific capture of BAX 855 by an anti-PEG IgG preparation, followed by a chromogenic FVIII activity assay. The assay principle enabled sensitive measurement of the FVIII cofactor activity of BAX 855 down to the pM-range without interference by non-PEGylated FVIII. The selectivity of the capture step, shown by competition studies to primarily target the terminal methoxy group of PEG, also allowed assessment of the intactness of the attached PEG chains. Altogether, the modification-dependent activity not only enriches, but complements the group of methods to selectively, accurately, and precisely measure a PEGylated drug in complex biological matrices. In contrast to all other methods described so far, it allows measurement of the biological activity of the PEGylated protein. Data obtained demonstrate that this new method principle can be extended to protein modifications other than PEGylation and to a variety of functional activity assays. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Reward salience and risk aversion underlie differential ACC activity in substance dependence.

    Science.gov (United States)

    Alexander, William H; Fukunaga, Rena; Finn, Peter; Brown, Joshua W

    2015-01-01

    The medial prefrontal cortex, especially the dorsal anterior cingulate cortex (ACC), has long been implicated in cognitive control and error processing. Although the association between ACC and behavior has been established, it is less clear how ACC contributes to dysfunctional behavior such as substance dependence. Evidence from neuroimaging studies investigating ACC function in substance users is mixed, with some studies showing disengagement of ACC in substance dependent individuals (SDs), while others show increased ACC activity related to substance use. In this study, we investigate ACC function in SDs and healthy individuals performing a change signal task for monetary rewards. Using a priori predictions derived from a recent computational model of ACC, we find that ACC activity differs between SDs and controls in factors related to reward salience and risk aversion between SDs and healthy individuals. Quantitative fits of a computational model to fMRI data reveal significant differences in best fit parameters for reward salience and risk preferences. Specifically, the ACC in SDs shows greater risk aversion, defined as concavity in the utility function, and greater attention to rewards relative to reward omission. Furthermore, across participants risk aversion and reward salience are positively correlated. The results clarify the role that ACC plays in both the reduced sensitivity to omitted rewards and greater reward valuation in SDs. Clinical implications of applying computational modeling in psychiatry are also discussed.

  19. The quantitative basis of the Arabidopsis innate immune system to endemic pathogens depends on pathogen genetics

    DEFF Research Database (Denmark)

    Corwin, Jason A; Copeland, Daniel; Feusier, Julie

    2016-01-01

    The most established model of the eukaryotic innate immune system is derived from examples of large effect monogenic quantitative resistance to pathogens. However, many host-pathogen interactions involve many genes of small to medium effect and exhibit quantitative resistance. We used the Arabido......The most established model of the eukaryotic innate immune system is derived from examples of large effect monogenic quantitative resistance to pathogens. However, many host-pathogen interactions involve many genes of small to medium effect and exhibit quantitative resistance. We used....... cinerea, we identified a total of 2,982 genes associated with quantitative resistance using lesion area and 3,354 genes associated with camalexin production as measures of the interaction. Most genes were associated with resistance to a specific Botrytis isolate, which demonstrates the influence...... genes associated with quantitative resistance. Using publically available co-expression data, we condensed the quantitative resistance associated genes into co-expressed gene networks. GO analysis of these networks implicated several biological processes commonly connected to disease resistance...

  20. Quantitation of fibroblast activation protein (FAP-specific protease activity in mouse, baboon and human fluids and organs

    Directory of Open Access Journals (Sweden)

    Fiona M. Keane

    2014-01-01

    Full Text Available The protease fibroblast activation protein (FAP is a specific marker of activated mesenchymal cells in tumour stroma and fibrotic liver. A specific, reliable FAP enzyme assay has been lacking. FAP's unique and restricted cleavage of the post proline bond was exploited to generate a new specific substrate to quantify FAP enzyme activity. This sensitive assay detected no FAP activity in any tissue or fluid of FAP gene knockout mice, thus confirming assay specificity. Circulating FAP activity was ∼20- and 1.3-fold less in baboon than in mouse and human plasma, respectively. Serum and plasma contained comparable FAP activity. In mice, the highest levels of FAP activity were in uterus, pancreas, submaxillary gland and skin, whereas the lowest levels were in brain, prostate, leukocytes and testis. Baboon organs high in FAP activity included skin, epididymis, bladder, colon, adipose tissue, nerve and tongue. FAP activity was greatly elevated in tumours and associated lymph nodes and in fungal-infected skin of unhealthy baboons. FAP activity was 14- to 18-fold greater in cirrhotic than in non-diseased human liver, and circulating FAP activity was almost doubled in alcoholic cirrhosis. Parallel DPP4 measurements concorded with the literature, except for the novel finding of high DPP4 activity in bile. The new FAP enzyme assay is the first to be thoroughly characterised and shows that FAP activity is measurable in most organs and at high levels in some. This new assay is a robust tool for specific quantitation of FAP enzyme activity in both preclinical and clinical samples, particularly liver fibrosis.

  1. Abscisic acid-dependent multisite phosphorylation regulates the activity of a transcription activator AREB1

    OpenAIRE

    Furihata, Takashi; Maruyama, Kyonoshin; Fujita, Yasunari; Umezawa, Taishi; Yoshida, Riichiro; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

    2006-01-01

    bZIP-type transcription factors AREBs/ABFs bind an abscisic acid (ABA)-responsive cis-acting element named ABRE and transactivate downstream gene expression in Arabidopsis. Because AREB1 overexpression could not induce downstream gene expression, activation of AREB1 requires ABA-dependent posttranscriptional modification. We confirmed that ABA activated 42-kDa kinase activity, which, in turn, phosphorylated Ser/Thr residues of R-X-X-S/T sites in the conserved regions of AREB1. Amino acid subs...

  2. Health Impacts of Increased Physical Activity from Changes in Transportation Infrastructure: Quantitative Estimates for Three Communities

    Science.gov (United States)

    2015-01-01

    Recently, two quantitative tools have emerged for predicting the health impacts of projects that change population physical activity: the Health Economic Assessment Tool (HEAT) and Dynamic Modeling for Health Impact Assessment (DYNAMO-HIA). HEAT has been used to support health impact assessments of transportation infrastructure projects, but DYNAMO-HIA has not been previously employed for this purpose nor have the two tools been compared. To demonstrate the use of DYNAMO-HIA for supporting health impact assessments of transportation infrastructure projects, we employed the model in three communities (urban, suburban, and rural) in North Carolina. We also compared DYNAMO-HIA and HEAT predictions in the urban community. Using DYNAMO-HIA, we estimated benefit-cost ratios of 20.2 (95% C.I.: 8.7–30.6), 0.6 (0.3–0.9), and 4.7 (2.1–7.1) for the urban, suburban, and rural projects, respectively. For a 40-year time period, the HEAT predictions of deaths avoided by the urban infrastructure project were three times as high as DYNAMO-HIA's predictions due to HEAT's inability to account for changing population health characteristics over time. Quantitative health impact assessment coupled with economic valuation is a powerful tool for integrating health considerations into transportation decision-making. However, to avoid overestimating benefits, such quantitative HIAs should use dynamic, rather than static, approaches. PMID:26504832

  3. Rapid and Quantitative Assay of Amyloid-Seeding Activity in Human Brains Affected with Prion Diseases.

    Directory of Open Access Journals (Sweden)

    Hanae Takatsuki

    Full Text Available The infectious agents of the transmissible spongiform encephalopathies are composed of amyloidogenic prion protein, PrPSc. Real-time quaking-induced conversion can amplify very small amounts of PrPSc seeds in tissues/body fluids of patients or animals. Using this in vitro PrP-amyloid amplification assay, we quantitated the seeding activity of affected human brains. End-point assay using serially diluted brain homogenates of sporadic Creutzfeldt-Jakob disease patients demonstrated that 50% seeding dose (SD50 is reached approximately 10(10/g brain (values varies 10(8.79-10.63/g. A genetic case (GSS-P102L yielded a similar level of seeding activity in an autopsy brain sample. The range of PrPSc concentrations in the samples, determined by dot-blot assay, was 0.6-5.4 μg/g brain; therefore, we estimated that 1 SD50 unit was equivalent to 0.06-0.27 fg of PrPSc. The SD50 values of the affected brains dropped more than three orders of magnitude after autoclaving at 121°C. This new method for quantitation of human prion activity provides a new way to reduce the risk of iatrogenic prion transmission.

  4. Quantitative Structure activity relationship and risk analysis of some pesticides in the cattle milk

    OpenAIRE

    Faqir Muhammad*, Ijaz Javed, Masood Akhtar1, Zia-ur-Rahman, Mian Muhammad Awais1, Muhammad Kashif Saleemi2 and Muhammad Irfan Anwar3

    2012-01-01

    Milk of cattle was collected from various localities of Faisalabad, Pakistan. Pesticides concentration was determined by HPLC using solid phase microextraction. The residue analysis revealed that about 40% milk samples were contaminated with pesticides. The mean±SE levels (ppm) of cyhalothrin, endosulfan, chlorpyrifos and cypermethrin were 0.38±0.02, 0.26±0.02, 0.072±0.01 and 0.085±0.02, respectively. Quantitative structure activity relationship (QSAR) models were used to predict the residues...

  5. Xanthene derivatives increase glucose utilization through activation of LKB1-dependent AMP-activated protein kinase.

    Directory of Open Access Journals (Sweden)

    Yonghoon Kwon

    Full Text Available 5' AMP-activated protein kinase (AMPK is a highly conserved serine-threonine kinase that regulates energy expenditure by activating catabolic metabolism and suppressing anabolic pathways to increase cellular energy levels. Therefore AMPK activators are considered to be drug targets for treatment of metabolic diseases such as diabetes mellitus. To identify novel AMPK activators, we screened xanthene derivatives. We determined that the AMPK activators 9H-xanthene-9-carboxylic acid {2,2,2-trichloro-1-[3-(3-nitro-phenyl-thioureido]-ethyl}-amide (Xn and 9H-xanthene-9-carboxylic acid {2,2,2-trichloro-1-[3-(3-cyano-phenyl-thioureido]-ethyl}-amide (Xc elevated glucose uptake in L6 myotubes by stimulating translocation of glucose transporter type 4 (GLUT4. Treatment with the chemical AMPK inhibitor compound C and infection with dominant-negative AMPKa2-virus inhibited AMPK phosphorylation and glucose uptake in myotubes induced by either Xn or Xc. Of the two major upstream kinases of AMPK, we found that Xn and Xc showed LKB1 dependency by knockdown of STK11, an ortholog of human LKB1. Single intravenous administration of Xn and Xc to high-fat diet-induced diabetic mice stimulated AMPK phosphorylation of skeletal muscle and improved glucose tolerance. Taken together, these results suggest that Xn and Xc regulate glucose homeostasis through LKB1-dependent AMPK activation and that the compounds are potential candidate drugs for the treatment of type 2 diabetes mellitus.

  6. Bone mineral density changes during pregnancy in actively exercising women as measured by quantitative ultrasound.

    Science.gov (United States)

    To, William W K; Wong, Margaret W N

    2012-08-01

    To evaluate whether bone mineral density (BMD) changes in women engaged in active exercises during pregnancy would be different from non-exercising women. Consecutive patients with singleton pregnancies who were engaged in active exercise training during pregnancy were prospectively recruited over a period of 6 months. Quantitative USG measurements of the os calcis BMD were performed at 14-20 weeks and at 36-38 weeks. These patients were compared to a control cohort of non-exercising low-risk women. A total of 24 physically active women undergoing active physical training of over 10 h per week at 20 weeks gestation and beyond (mean 13.1 h, SD 3.3) were compared to 94 non-exercising low-risk women. A marginal fall in BMD of 0.015 g/cm(2) (SD 0.034) was demonstrable from early to late gestation in the exercising women, which was significantly lower than that of non-exercising women (0.041 g/cm(2); SD 0.042; p = 0.005). Logistic regression models confirmed that active exercises in pregnancy were significantly associated with the absence of or less BMD loss in pregnancy. In women actively engaged in physical training during pregnancy, the physiological fall in BMD during pregnancy was apparently less compared to those who did not regularly exercise.

  7. Quantitative structure-activity relationship modeling on in vitro endocrine effects and metabolic stability involving 26 selected brominated flame retardants

    NARCIS (Netherlands)

    Harju, M.; Hamers, T.; Kamstra, J.H.; Sonneveld, E.; Boon, J.P.

    2007-01-01

    In this work, quantitative structure-activity relationships (QSARs) were developed to aid human and environmental risk assessment processes for brominated flame retardants (BFRs). Brominated flame retardants, such as the high-production-volume chemicals polybrominated diphenyl ethers (PBDEs),

  8. Scintigraphic quantitation of gastrointestinal motor activity and transport: Oesophagus and stomach

    International Nuclear Information System (INIS)

    Stacher, G.; Bergmann, H.

    1992-01-01

    For the recognition and characterisation of oesophageal motor disorders, manometry represents the most reliable tool but yields no information on bolus transport. The transport can be quantitated by radionuclide techniques. The patient is positioned supine beneath a gamma-camera and instructed to swallow a radiolabelled bolus in a single gulp. Using a marker over the cricoid and the activity in the stomach as landmarks, regions of interest are drawn representing the upper, middle and lower third of the oesophagus and the gastric fundus. Activity-time curves enable one to recognise the clearance patterns in these regions. In combination, manometric and radionuclide transit studies recognise a higher number of motor disorders than either procedure alone. Radionuclide methods also are the most reliable and sensitive to quantitate gastric emptying. Procedure, meal size and composition as well as patient position must be standardised and correction techniques applied. The emptying of solid and liquid meal constituents can be evaluated concomitantly. Solids start to empty only after a lag phase of varying extent. With semi-solid meals, which are emptied at the same rate as solid meals of identical composition in the postlag phase, the recording time can be considerably shorter. Besides gastric emptying, the amplitude, frequency and propagation velocity of antral contractions can be recorded using serial images of short frame time and specially devised analytic techniques. (orig.)

  9. Scintigraphic quantitation of gastrointestinal motor activity and transport: Oesophagus and stomach

    Energy Technology Data Exchange (ETDEWEB)

    Stacher, G.; Bergmann, H. (Vienna Univ. (Austria). Psychiatrische Klinik Vienna Univ. (Austria). 1. Chirurgische Klinik Ludwig-Boltzmann-Institut fuer Nuklearmedizin, Vienna (Austria))

    1992-09-01

    For the recognition and characterisation of oesophageal motor disorders, manometry represents the most reliable tool but yields no information on bolus transport. The transport can be quantitated by radionuclide techniques. The patient is positioned supine beneath a gamma-camera and instructed to swallow a radiolabelled bolus in a single gulp. Using a marker over the cricoid and the activity in the stomach as landmarks, regions of interest are drawn representing the upper, middle and lower third of the oesophagus and the gastric fundus. Activity-time curves enable one to recognise the clearance patterns in these regions. In combination, manometric and radionuclide transit studies recognise a higher number of motor disorders than either procedure alone. Radionuclide methods also are the most reliable and sensitive to quantitate gastric emptying. Procedure, meal size and composition as well as patient position must be standardised and correction techniques applied. The emptying of solid and liquid meal constituents can be evaluated concomitantly. Solids start to empty only after a lag phase of varying extent. With semi-solid meals, which are emptied at the same rate as solid meals of identical composition in the postlag phase, the recording time can be considerably shorter. Besides gastric emptying, the amplitude, frequency and propagation velocity of antral contractions can be recorded using serial images of short frame time and specially devised analytic techniques. (orig.).

  10. Using quantitative structure-activity relationships (QSAR) to predict toxic endpoints for polycyclic aromatic hydrocarbons (PAH).

    Science.gov (United States)

    Bruce, Erica D; Autenrieth, Robin L; Burghardt, Robert C; Donnelly, K C; McDonald, Thomas J

    2008-01-01

    Quantitative structure-activity relationships (QSAR) offer a reliable, cost-effective alternative to the time, money, and animal lives necessary to determine chemical toxicity by traditional methods. Additionally, humans are exposed to tens of thousands of chemicals in their lifetimes, necessitating the determination of chemical toxicity and screening for those posing the greatest risk to human health. This study developed models to predict toxic endpoints for three bioassays specific to several stages of carcinogenesis. The ethoxyresorufin O-deethylase assay (EROD), the Salmonella/microsome assay, and a gap junction intercellular communication (GJIC) assay were chosen for their ability to measure toxic endpoints specific to activation-, induction-, and promotion-related effects of polycyclic aromatic hydrocarbons (PAH). Shape-electronic, spatial, information content, and topological descriptors proved to be important descriptors in predicting the toxicity of PAH in these bioassays. Bioassay-based toxic equivalency factors (TEF(B)) were developed for several PAH using the quantitative structure-toxicity relationships (QSTR) developed. Predicting toxicity for a specific PAH compound, such as a bioassay-based potential potency (PP(B)) or a TEF(B), is possible by combining the predicted behavior from the QSTR models. These toxicity estimates may then be incorporated into a risk assessment for compounds that lack toxicity data. Accurate toxicity predictions are made by examining each type of endpoint important to the process of carcinogenicity, and a clearer understanding between composition and toxicity can be obtained.

  11. Qualitative and quantitative measurement of human brain activity using pixel subtraction algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Myoung; Jeong, Gwang Woo; Kim, Hyung Joong; Cho, Seong Hoon; Kang, Heoung Keun; Seo, Jeong Jin; Park, Seung Jin [School of Medicine, Chonnam National Univ., Kwangju (Korea, Republic of)

    2004-08-01

    manual quantification method showed an average error of 0.334{+-}0.007 (%). Thus, the manual counting method gave less accurate quantitative information on brain activation than the FALBA program. The FALBA program is capable of providing accurate quantitative results, including the identification of the brain activation region and lateralization index with respect to the functional and anatomical areas. Also, the processing time was dramatically shortened in comparison with the manual counting method.

  12. Qualitative and quantitative measurement of human brain activity using pixel subtraction algorithm

    International Nuclear Information System (INIS)

    Lee, Jin Myoung; Jeong, Gwang Woo; Kim, Hyung Joong; Cho, Seong Hoon; Kang, Heoung Keun; Seo, Jeong Jin; Park, Seung Jin

    2004-01-01

    quantification method showed an average error of 0.334±0.007 (%). Thus, the manual counting method gave less accurate quantitative information on brain activation than the FALBA program. The FALBA program is capable of providing accurate quantitative results, including the identification of the brain activation region and lateralization index with respect to the functional and anatomical areas. Also, the processing time was dramatically shortened in comparison with the manual counting method

  13. Quantitative Structure Activity Relationship of Cinnamaldehyde Compounds against Wood-Decaying Fungi

    Directory of Open Access Journals (Sweden)

    Dongmei Yang

    2016-11-01

    Full Text Available Cinnamaldehyde, of the genius Cinnamomum, is a major constituent of the bark of the cinnamon tree and possesses broad-spectrum antimicrobial activity. In this study, we used best multiple linear regression (BMLR to develop quantitative structure activity relationship (QSAR models for cinnamaldehyde derivatives against wood-decaying fungi Trametes versicolor and Gloeophyllun trabeum. Based on the two optimal QSAR models, we then designed and synthesized two novel cinnamaldehyde compounds. The QSAR models exhibited good correlation coefficients: R2Tv = 0.910 for Trametes versicolor and R2Gt = 0.926 for Gloeophyllun trabeum. Small errors between the experimental and calculated values of two designed compounds indicated that these two QSAR models have strong predictability and stability.

  14. Synthesis, quantitative structure-property relationship study of novel fluorescence active 2-pyrazolines and application

    Science.gov (United States)

    Girgis, Adel S.; Basta, Altaf H.; El-Saied, Houssni; Mohamed, Mohamed A.; Bedair, Ahmad H.; Salim, Ahmad S.

    2018-03-01

    A variety of fluorescence-active fluorinated pyrazolines 13-33 was synthesized in good yields through cyclocondensation reaction of propenones 1-9 with aryl hydrazines 10-12. Some of the synthesized compounds provided promising fluorescence properties with quantum yield (Φ) higher than that of quinine sulfate (standard reference). Quantitative structure-property relationship studies were undertaken supporting the exhibited fluorescence properties and estimating the parameters governing properties. Five synthesized fluorescence-active pyrazolines (13, 15, 18, 19 and 23) with variable Φ were selected for treating two types of paper sheets (Fabriano and Bible paper). These investigated fluorescence compounds, especially compounds 19 and 23, provide improvements in strength properties of paper sheets. Based on the observed performance they can be used as markers in security documents.

  15. Quantitative structure-activity relationships of selective antagonists of glucagon receptor using QuaSAR descriptors.

    Science.gov (United States)

    Manoj Kumar, Palanivelu; Karthikeyan, Chandrabose; Hari Narayana Moorthy, Narayana Subbiah; Trivedi, Piyush

    2006-11-01

    In the present paper, quantitative structure activity relationship (QSAR) approach was applied to understand the affinity and selectivity of a novel series of triaryl imidazole derivatives towards glucagon receptor. Statistically significant and highly predictive QSARs were derived for glucagon receptor inhibition by triaryl imidazoles using QuaSAR descriptors of molecular operating environment (MOE) employing computer-assisted multiple regression procedure. The generated QSAR models revealed that factors related to hydrophobicity, molecular shape and geometry predominantly influences glucagon receptor binding affinity of the triaryl imidazoles indicating the relevance of shape specific steric interactions between the molecule and the receptor. Further, QSAR models formulated for selective inhibition of glucagon receptor over p38 mitogen activated protein (MAP) kinase of the compounds in the series highlights that the same structural features, which influence the glucagon receptor affinity, also contribute to their selective inhibition.

  16. QUANTITATIVE ELECTRONIC STRUCTURE - ACTIVITY RELATIONSHIP OF ANTIMALARIAL COMPOUND OF ARTEMISININ DERIVATIVES USING PRINCIPAL COMPONENT REGRESSION APPROACH

    Directory of Open Access Journals (Sweden)

    Paul Robert Martin Werfette

    2010-06-01

    Full Text Available Analysis of quantitative structure - activity relationship (QSAR for a series of antimalarial compound artemisinin derivatives has been done using principal component regression. The descriptors for QSAR study were representation of electronic structure i.e. atomic net charges of the artemisinin skeleton calculated by AM1 semi-empirical method. The antimalarial activity of the compound was expressed in log 1/IC50 which is an experimental data. The main purpose of the principal component analysis approach is to transform a large data set of atomic net charges to simplify into a data set which known as latent variables. The best QSAR equation to analyze of log 1/IC50 can be obtained from the regression method as a linear function of several latent variables i.e. x1, x2, x3, x4 and x5. The best QSAR model is expressed in the following equation,  (;;   Keywords: QSAR, antimalarial, artemisinin, principal component regression

  17. Introduction to the Symposium "Leading Students and Faculty to Quantitative Biology through Active Learning".

    Science.gov (United States)

    Waldrop, Lindsay D; Miller, Laura A

    2015-11-01

    The broad aim of this symposium and set of associated papers is to motivate the use of inquiry-based, active-learning teaching techniques in undergraduate quantitative biology courses. Practical information, resources, and ready-to-use classroom exercises relevant to physicists, mathematicians, biologists, and engineers are presented. These resources can be used to address the lack of preparation of college students in STEM fields entering the workforce by providing experience working on interdisciplinary and multidisciplinary problems in mathematical biology in a group setting. Such approaches can also indirectly help attract and retain under-represented students who benefit the most from "non-traditional" learning styles and strategies, including inquiry-based, collaborative, and active learning. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  18. Cultural differences in human brain activity: a quantitative meta-analysis.

    Science.gov (United States)

    Han, Shihui; Ma, Yina

    2014-10-01

    Psychologists have been trying to understand differences in cognition and behavior between East Asian and Western cultures within a single cognitive framework such as holistic versus analytic or interdependent versus independent processes. However, it remains unclear whether cultural differences in multiple psychological processes correspond to the same or different neural networks. We conducted a quantitative meta-analysis of 35 functional MRI studies to examine cultural differences in brain activity engaged in social and non-social processes. We showed that social cognitive processes are characterized by stronger activity in the dorsal medial prefrontal cortex, lateral frontal cortex and temporoparietal junction in East Asians but stronger activity in the anterior cingulate, ventral medial prefrontal cortex and bilateral insula in Westerners. Social affective processes are associated with stronger activity in the right dorsal lateral frontal cortex in East Asians but greater activity in the left insula and right temporal pole in Westerners. Non-social processes induce stronger activity in the left inferior parietal cortex, left middle occipital and left superior parietal cortex in East Asians but greater activations in the right lingual gyrus, right inferior parietal cortex and precuneus in Westerners. The results suggest that cultural differences in social and non-social processes are mediated by distinct neural networks. Moreover, East Asian cultures are associated with increased neural activity in the brain regions related to inference of others' mind and emotion regulation whereas Western cultures are associated with enhanced neural activity in the brain areas related to self-relevance encoding and emotional responses during social cognitive/affective processes. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Quantitative Evaluation of Stomatal Cytoskeletal Patterns during the Activation of Immune Signaling in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Masaki Shimono

    Full Text Available Historically viewed as primarily functioning in the regulation of gas and water vapor exchange, it is now evident that stomata serve an important role in plant immunity. Indeed, in addition to classically defined functions related to cell architecture and movement, the actin cytoskeleton has emerged as a central component of the plant immune system, underpinning not only processes related to cell shape and movement, but also receptor activation and signaling. Using high resolution quantitative imaging techniques, the temporal and spatial changes in the actin microfilament array during diurnal cycling of stomatal guard cells has revealed a highly orchestrated transition from random arrays to ordered bundled filaments. While recent studies have demonstrated that plant stomata close in response to pathogen infection, an evaluation of stimulus-induced changes in actin cytoskeletal dynamics during immune activation in the guard cell, as well as the relationship of these changes to the function of the actin cytoskeleton and stomatal aperture, remains undefined. In the current study, we employed quantitative cell imaging and hierarchical clustering analyses to define the response of the guard cell actin cytoskeleton to pathogen infection and the elicitation of immune signaling. Using this approach, we demonstrate that stomatal-localized actin filaments respond rapidly, and specifically, to both bacterial phytopathogens and purified pathogen elicitors. Notably, we demonstrate that higher order temporal and spatial changes in the filament array show distinct patterns of organization during immune activation, and that changes in the naïve diurnal oscillations of guard cell actin filaments are perturbed by pathogens, and that these changes parallel pathogen-induced stomatal gating. The data presented herein demonstrate the application of a highly tractable and quantifiable method to assign transitions in actin filament organization to the activation of

  20. Quantitative MR imaging of intra-orbital structures: Tissue-specific measurements and age dependency compared to extra-orbital structures using multispectral quantitative MR imaging.

    Science.gov (United States)

    Watanabe, Memi; Buch, Karen; Fujita, Akifumi; Jara, Hernán; Qureshi, Muhammad Mustafa; Sakai, Osamu

    2017-08-01

    The orbit can be affected by unique pathologic conditions and often requires MRI evaluation. The purpose of this study was to investigate the age-related changes in multiple intra-orbital structures using quantitative MRI (qMRI). Thirty-eight subjects (20 males, 18 females; ages 0.5-87 years) underwent MRI with a mixed turbo spin echo sequence. T1 and T2 measurements were obtained within ROI in 6 intra-orbital structures (medial and lateral rectus muscles, medial and lateral retrobulbar fat, lacrimal gland, and optic nerve), and compared with those of corresponding extra-orbital structures (masseter muscle, subcutaneous cheek fat, buccal fat, parotid gland, and frontal white matter). Statistical analyses were performed using Pearson's correlation coefficients. T1 and T2 values of the extra-ocular muscles increased with age, with higher T1 and T2 values compared to the masseter muscles. Retrobulbar fat showed significant age-associated increases in T1 values in the lateral side and in T2 values in both sides. T1 and T2 values in the lacrimal gland increased with age, while the parotid gland showed an age-associated increase in T2 values and decrease in T1 values. Optic nerves demonstrated age-related changes, similar to that of frontal white matter; rapid decreases with age in T1 and T2 times in early stages of life, and slight increases in T1 and T2 times later in life. Intra-orbital structures demonstrated specific qMRI measurements and aging patterns, which were different from extra-orbital structures. Location-specific age-related changes of intra-orbital structures should be considered in the qMRI assessment of the orbital pathology.

  1. Quantitative comparison of HTLV-1 and HIV-1 cell-to-cell infection with new replication dependent vectors.

    Directory of Open Access Journals (Sweden)

    Dmitriy Mazurov

    2010-02-01

    Full Text Available We have developed an efficient method to quantify cell-to-cell infection with single-cycle, replication dependent reporter vectors. This system was used to examine the mechanisms of infection with HTLV-1 and HIV-1 vectors in lymphocyte cell lines. Effector cells transfected with reporter vector, packaging vector, and Env expression plasmid produced virus-like particles that transduced reporter gene activity into cocultured target cells with zero background. Reporter gene expression was detected exclusively in target cells and required an Env-expression plasmid and a viral packaging vector, which provided essential structural and enzymatic proteins for virus replication. Cell-cell fusion did not contribute to infection, as reporter protein was rarely detected in syncytia. Coculture of transfected Jurkat T cells and target Raji/CD4 B cells enhanced HIV-1 infection two fold and HTLV-1 infection ten thousand fold in comparison with cell-free infection of Raji/CD4 cells. Agents that interfere with actin and tubulin polymerization strongly inhibited HTLV-1 and modestly decreased HIV-1 cell-to-cell infection, an indication that cytoskeletal remodeling was more important for HTLV-1 transmission. Time course studies showed that HTLV-1 transmission occurred very rapidly after cell mixing, whereas slower kinetics of HIV-1 coculture infection implies a different mechanism of infectious transmission. HTLV-1 Tax was demonstrated to play an important role in altering cell-cell interactions that enhance virus infection and replication. Interestingly, superantigen-induced synapses between Jurkat cells and Raji/CD4 cells did not enhance infection for either HTLV-1 or HIV-1. In general, the dependence on cell-to-cell infection was determined by the virus, the effector and target cell types, and by the nature of the cell-cell interaction.

  2. Which learning activities enhance physiotherapy practice? A systematic review protocol of quantitative and qualitative studies.

    Science.gov (United States)

    Leahy, Edmund; Chipchase, Lucy; Blackstock, Felicity

    2017-04-17

    Learning activities are fundamental for the development of expertise in physiotherapy practice. Continuing professional development (CPD) encompasses formal and informal learning activities undertaken by physiotherapists. Identifying the most efficient and effective learning activities is essential to enable the profession to assimilate research findings and improve clinical skills to ensure the most efficacious care for clients. To date, systematic reviews on the effectiveness of CPD provide limited guidance on the most efficacious models of professional development for physiotherapists. The aim of this systematic review is to evaluate which learning activities enhance physiotherapy practice. A search of Ovid MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO (Psychological Abstracts), PEDro, Cochrane Library, AMED and Educational Resources and Information Center (ERIC) will be completed. Citation searching and reference list searching will be undertaken to locate additional studies. Quantitative and qualitative studies will be included if they examine the impact of learning activities on clinician's behaviour, attitude, knowledge, beliefs, skills, self-efficacy, work satisfaction and patient outcomes. Risk of bias will be assessed by two independent researchers. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) and Confidence in the Evidence from Reviews of Qualitative research (CERQual) will be used to synthesise results where a meta-analysis is possible. Where a meta-analysis is not possible, a narrative synthesis will be conducted. PROSPERO CRD42016050157.

  3. Quantitative Structure-Activity Relationship of Insecticidal Activity of Benzyl Ether Diamidine Derivatives

    Science.gov (United States)

    Zhai, Mengting; Chen, Yan; Li, Jing; Zhou, Jun

    2017-12-01

    The molecular electrongativity distance vector (MEDV-13) was used to describe the molecular structure of benzyl ether diamidine derivatives in this paper, Based on MEDV-13, The three-parameter (M 3, M 15, M 47) QSAR model of insecticidal activity (pIC 50) for 60 benzyl ether diamidine derivatives was constructed by leaps-and-bounds regression (LBR) . The traditional correlation coefficient (R) and the cross-validation correlation coefficient (R CV ) were 0.975 and 0.971, respectively. The robustness of the regression model was validated by Jackknife method, the correlation coefficient R were between 0.971 and 0.983. Meanwhile, the independent variables in the model were tested to be no autocorrelation. The regression results indicate that the model has good robust and predictive capabilities. The research would provide theoretical guidance for the development of new generation of anti African trypanosomiasis drugs with efficiency and low toxicity.

  4. Muscle activity pattern dependent pain development and alleviation

    DEFF Research Database (Denmark)

    Sjøgaard, Gisela; Søgaard, Karen

    2014-01-01

    Muscle activity is for decades considered to provide health benefits irrespectively of the muscle activity pattern performed and whether it is during e.g. sports, transportation, or occupational work tasks. Accordingly, the international recommendations for public health-promoting physical activity...... do not distinguish between occupational and leisure time physical activity. However, in this body of literature, attention has not been paid to the extensive documentation on occupational physical activity imposing a risk of impairment of health - in particular musculoskeletal health in terms...... during physical activities at leisure and sport the motor recruitment patterns are more dynamic including regularly relatively high muscle forces - also activating type 2 muscles fibers - as well as periods of full relaxation even of the type 1 muscle fibers. Such activity is unrelated to muscle pain...

  5. Antimicrobial activity of Algerian propolis in foodborne pathogens and its quantitative chemical composition

    Directory of Open Access Journals (Sweden)

    Neila Nedji

    2014-12-01

    Full Text Available Objective: To evaluate the antimicrobial activity of propolis samples collected from different regions of Algeria and their chemical composition. Methods: The antibacterial activity of ethanolic extract of Algerian propolis against Bacillus cereus (IPA, Staphylococcus aureus (ATCC25923R, Escherichia coli (ATCC25922 and Pseudomonas aeruginosa (ATCC27893R was evaluated by the disc diffusion method and determined as an equivalent of the inhibition zones diameters after incubation of the cultures at 37 °C for 24 h. The investigation of the polyphenol and flavonoid contents was done spectrophotometrically. Results: The ethanolic extract of Algerian propolis samples inhibited the growth of all examined microorganisms with the highest antimicrobial activity against the Gram-positive bacteria. Polyphenol and flavonoids contents were variable, depending on the propolis samples and a positive correlation between antimicrobial activity and chemical composition was observed. Conclusions: Antimicrobial activity, polyphenol and flavonoid contents were variable, depending on the propolis sample. The strong antimicrobial activity of Algerian propolis may be due to high total phenolic and flavonoid contents and this study suggests potential use of propolis in foods.

  6. Joint reconstruction of activity and attenuation in Time-of-Flight PET: A Quantitative Analysis.

    Science.gov (United States)

    Rezaei, Ahmadreza; Deroose, Christophe M; Vahle, Thomas; Boada, Fernando; Nuyts, Johan

    2018-03-01

    Joint activity and attenuation reconstruction methods from time of flight (TOF) positron emission tomography (PET) data provide an effective solution to attenuation correction when no (or incomplete/inaccurate) information on the attenuation is available. One of the main barriers limiting their use in clinical practice is the lack of validation of these methods on a relatively large patient database. In this contribution, we aim at validating the activity reconstructions of the maximum likelihood activity reconstruction and attenuation registration (MLRR) algorithm on a whole-body patient data set. Furthermore, a partial validation (since the scale problem of the algorithm is avoided for now) of the maximum likelihood activity and attenuation reconstruction (MLAA) algorithm is also provided. We present a quantitative comparison of the joint reconstructions to the current clinical gold-standard maximum likelihood expectation maximization (MLEM) reconstruction with CT-based attenuation correction. Methods: The whole-body TOF-PET emission data of each patient data set is processed as a whole to reconstruct an activity volume covering all the acquired bed positions, which helps to reduce the problem of a scale per bed position in MLAA to a global scale for the entire activity volume. Three reconstruction algorithms are used: MLEM, MLRR and MLAA. A maximum likelihood (ML) scaling of the single scatter simulation (SSS) estimate to the emission data is used for scatter correction. The reconstruction results are then analyzed in different regions of interest. Results: The joint reconstructions of the whole-body patient data set provide better quantification in case of PET and CT misalignments caused by patient and organ motion. Our quantitative analysis shows a difference of -4.2% (±2.3%) and -7.5% (±4.6%) between the joint reconstructions of MLRR and MLAA compared to MLEM, averaged over all regions of interest, respectively. Conclusion: Joint activity and attenuation

  7. Cation dependency of the hydrolytic activity of activated bovine Protein C

    International Nuclear Information System (INIS)

    Hill, K.A.W.

    1986-01-01

    The hydrolytic activity of activated bovine plasma Protein C (APC) is dependent upon monovalent or divalent cations. The kinetics of APC activity were examined with a variety of monovalent and divalent cations, and significant differences were observed. Similar studies were performed with des(1-41, light chain)APC (GDAPC), from which all γ-carboxyglutamic acid residues have been removed. These studies provided useful information concerning the cation dependency. Divalent cations apparently stimulate APC and GDAPC kinetic activity through association at a single γ-carboxyglutamic acid-independent high affinity binding site. A Mn(II) binding site of this nature of GDAPC was determined by EPR spectroscopy, to possess a dissociation constant of 53 +/- 8 uM. Monovalent cations stimulate GDAPC activity through association at an apparently single binding site that is distinct from the divalent cation site. The monovalent cation , Tl(I), was determined, by 205 Tl(I) NMR spectroscopy, to bind to APC and GDAPC with dissociation constants of 16 +/- 8 mM and 32+/- 11 mM, respectively. Both NMR and EPR spectroscopy have been utilized to estimate topographical relationships between divalent cation sites, monovalent cation sites, and the active site of GDAPC. By observing the paramagnetic effects of either Mn(II) or an active site directed spin-label on the longitudinal relaxation rates of Tl(I) nuclei bound to this enzyme, the average interatomic distance between Mn(II) and Tl(I) was calculated to be 8.3 +/- 0.3 A, and the average distance between Tl(I) and the spin-label free electron was estimated to be 3.8 +/- 0.2 A

  8. Visualization of plant viral suppressor silencing activity in intact leaf lamina by quantitative fluorescent imaging

    Directory of Open Access Journals (Sweden)

    Francis Kevin P

    2011-08-01

    Full Text Available Abstract Background Transient expression of proteins in plants has become a favoured method over the production of stably transformed plants because, in addition to enabling high protein yields, it is both fast and easy to apply. An enhancement of transient protein expression can be achieved by plant virus-encoded RNA silencing suppressor proteins. Since viral suppressor proteins differ in their efficiency to enhance transient protein expression in plants, we developed a whole-leaf green fluorescent protein (GFP-based imaging assay to quantitatively assess suppressor protein activity. Results In a transient GFP-expression assay using wild-type and GFP-transgenic N. benthamiana, addition of the plant viral suppressors Beet mild yellowing virus (BMYV-IPP P0 or Plum pox virus (PPV HC-Pro was shown to increase fluorescent protein expression 3-4-fold, 7 days post inoculation (dpi when compared to control plants. In contrast, in agroinfiltrated patches without suppressor activity, near complete silencing of the GFP transgene was observed in the transgenic N. benthamiana at 21 dpi. Both co-infiltrated suppressors significantly enhanced GFP expression over time, with HC-Pro co-infiltrations leading to higher short term GFP fluorescence (at 7 dpi and P0 giving higher long term GFP fluorescence (at 21 dpi. Additionally, in contrast to HC-Pro co-infiltrations, an area of complete GFP silencing was observed at the edge of P0 co-infiltrated areas. Conclusions Fluorescence imaging of whole intact leaves proved to be an easy and effective method for spatially and quantitatively observing viral suppressor efficiency in plants. This suppressor assay demonstrates that plant viral suppressors greatly enhanced transient GFP expression, with P0 showing a more prolonged suppressor activity over time than HC-Pro. Both suppressors could prove to be ideal candidates for enhancing target protein expression in plants.

  9. Separation of DNA-dependent polymerate activities in Micrococcus radiodurans

    International Nuclear Information System (INIS)

    Kitayama, S.; Matsuyama, A.

    1977-01-01

    DNA polymerase activities in Micrococcus radiodurans were separated into two fractions after purification more than 2000 fold. They differ in pH optimum and residual activities in the absence of a full deoxyribonucleoside triphosphates complement. NAD partly inhibited one of the activities. Both activities were eluted as a single peak on gel filtration and sedimented at the same rate on glycerol gradient centrifugation. Molecular weight 140000 was calculated from Stokes radius and sedimentation constant. Deoxyribonuclease activity was detected on one of the polymerase activities which preferentially degraded double-stranded DNA. Priming activity of nicked DNA was reduced by γ-radiation. These results have been related to the possible roles in repair synthesis in vivo or DNA synthesis in permeable cells of M. radiodurans

  10. Separation of DNA-dependent polymerase activities in Micrococcus radiodurans

    Energy Technology Data Exchange (ETDEWEB)

    Kitayama, S; Matsuyama, A [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

    1977-03-02

    DNA polymerase activities in Micrococcus radiodurans were separated into two fractions after purification more than 2000 fold. They differ in pH optimum and residual activities in the absence of a full deoxyribonucleoside triphosphates complement. NAD partly inhibited one of the activities. Both activities were eluted as a single peak on gel filtration and sedimented at the same rate on glycerol gradient centrifugation. Molecular weight 140000 was calculated from Stokes radius and sedimentation constant. Deoxyribonuclease activity was detected on one of the polymerase activities which preferentially degraded double-stranded DNA. Priming activity of nicked DNA was reduced by ..gamma.. radiation. These results have been related to the possible roles in repair synthesis in vivo or DNA synthesis in permeable cells of M. radiodurans.

  11. A simplified method for quantitative assessment of the relative health and safety risk of environmental management activities

    International Nuclear Information System (INIS)

    Eide, S.A.; Smith, T.H.; Peatross, R.G.; Stepan, I.E.

    1996-09-01

    This report presents a simplified method to assess the health and safety risk of Environmental Management activities of the US Department of Energy (DOE). The method applies to all types of Environmental Management activities including waste management, environmental restoration, and decontamination and decommissioning. The method is particularly useful for planning or tradeoff studies involving multiple conceptual options because it combines rapid evaluation with a quantitative approach. The method is also potentially applicable to risk assessments of activities other than DOE Environmental Management activities if rapid quantitative results are desired

  12. Development and application of a quantitative multiplexed small GTPase activity assay using targeted proteomics.

    Science.gov (United States)

    Zhang, Cheng-Cheng; Li, Ru; Jiang, Honghui; Lin, Shujun; Rogalski, Jason C; Liu, Kate; Kast, Juergen

    2015-02-06

    Small GTPases are a family of key signaling molecules that are ubiquitously expressed in various types of cells. Their activity is often analyzed by western blot, which is limited by its multiplexing capability, the quality of isoform-specific antibodies, and the accuracy of quantification. To overcome these issues, a quantitative multiplexed small GTPase activity assay has been developed. Using four different binding domains, this assay allows the binding of up to 12 active small GTPase isoforms simultaneously in a single experiment. To accurately quantify the closely related small GTPase isoforms, a targeted proteomic approach, i.e., selected/multiple reaction monitoring, was developed, and its functionality and reproducibility were validated. This assay was successfully applied to human platelets and revealed time-resolved coactivation of multiple small GTPase isoforms in response to agonists and differential activation of these isoforms in response to inhibitor treatment. This widely applicable approach can be used for signaling pathway studies and inhibitor screening in many cellular systems.

  13. Quantitative evaluation of hidden defects in cast iron components using ultrasound activated lock-in vibrothermography.

    Science.gov (United States)

    Montanini, R; Freni, F; Rossi, G L

    2012-09-01

    This paper reports one of the first experimental results on the application of ultrasound activated lock-in vibrothermography for quantitative assessment of buried flaws in complex cast parts. The use of amplitude modulated ultrasonic heat generation allowed selective response of defective areas within the part, as the defect itself is turned into a local thermal wave emitter. Quantitative evaluation of hidden damages was accomplished by estimating independently both the area and the depth extension of the buried flaws, while x-ray 3D computed tomography was used as reference for sizing accuracy assessment. To retrieve flaw's area, a simple yet effective histogram-based phase image segmentation algorithm with automatic pixels classification has been developed. A clear correlation was found between the thermal (phase) signature measured by the infrared camera on the target surface and the actual mean cross-section area of the flaw. Due to the very fast cycle time (<30 s/part), the method could potentially be applied for 100% quality control of casting components.

  14. A quantitative speciation model for the adsorption of organic pollutants on activated carbon.

    Science.gov (United States)

    Grivé, M; García, D; Domènech, C; Richard, L; Rojo, I; Martínez, X; Rovira, M

    2013-01-01

    Granular activated carbon (GAC) is commonly used as adsorbent in water treatment plants given its high capacity for retaining organic pollutants in aqueous phase. The current knowledge on GAC behaviour is essentially empirical, and no quantitative description of the chemical relationships between GAC surface groups and pollutants has been proposed. In this paper, we describe a quantitative model for the adsorption of atrazine onto GAC surface. The model is based on results of potentiometric titrations and three types of adsorption experiments which have been carried out in order to determine the nature and distribution of the functional groups on the GAC surface, and evaluate the adsorption characteristics of GAC towards atrazine. Potentiometric titrations have indicated the existence of at least two different families of chemical groups on the GAC surface, including phenolic- and benzoic-type surface groups. Adsorption experiments with atrazine have been satisfactorily modelled with the geochemical code PhreeqC, assuming that atrazine is sorbed onto the GAC surface in equilibrium (log Ks = 5.1 ± 0.5). Independent thermodynamic calculations suggest a possible adsorption of atrazine on a benzoic derivative. The present work opens a new approach for improving the adsorption capabilities of GAC towards organic pollutants by modifying its chemical properties.

  15. Applying quantitative structure–activity relationship approaches to nanotoxicology: Current status and future potential

    International Nuclear Information System (INIS)

    Winkler, David A.; Mombelli, Enrico; Pietroiusti, Antonio; Tran, Lang; Worth, Andrew; Fadeel, Bengt; McCall, Maxine J.

    2013-01-01

    The potential (eco)toxicological hazard posed by engineered nanoparticles is a major scientific and societal concern since several industrial sectors (e.g. electronics, biomedicine, and cosmetics) are exploiting the innovative properties of nanostructures resulting in their large-scale production. Many consumer products contain nanomaterials and, given their complex life-cycle, it is essential to anticipate their (eco)toxicological properties in a fast and inexpensive way in order to mitigate adverse effects on human health and the environment. In this context, the application of the structure–toxicity paradigm to nanomaterials represents a promising approach. Indeed, according to this paradigm, it is possible to predict toxicological effects induced by chemicals on the basis of their structural similarity with chemicals for which toxicological endpoints have been previously measured. These structure–toxicity relationships can be quantitative or qualitative in nature and they can predict toxicological effects directly from the physicochemical properties of the entities (e.g. nanoparticles) of interest. Therefore, this approach can aid in prioritizing resources in toxicological investigations while reducing the ethical and monetary costs that are related to animal testing. The purpose of this review is to provide a summary of recent key advances in the field of QSAR modelling of nanomaterial toxicity, to identify the major gaps in research required to accelerate the use of quantitative structure–activity relationship (QSAR) methods, and to provide a roadmap for future research needed to achieve QSAR models useful for regulatory purposes

  16. Neurotrophin release by neurotrophins: Implications for activity-dependent neuronal plasticity

    OpenAIRE

    Canossa, Marco; Griesbeck, Oliver; Berninger, Benedikt; Campana, Gabriele; Kolbeck, Roland; Thoenen, Hans

    1997-01-01

    Neurotrophins, secreted in an activity-dependent manner, are thought to be involved in the activity-dependent refinement of synaptic connections. Here we demonstrate that in hippocampal neurons and the rat pheochromocytoma cell line PC12 application of exogenous neurotrophins induces secretion of neurotrophins, an effect that is mediated by the activation of tyrosine kinase neurotrophin receptors (Trks). Like activity-dependent secretion of neurotrophins, neurotrophin-induced neurotrophin sec...

  17. Activity-Dependent Regulation of Surface Glucose Transporter-3

    OpenAIRE

    Ferreira, Jainne M.; Burnett, Arthur L.; Rameau, Gerald A.

    2011-01-01

    Glucose transporter 3 (GLUT3) is the main facilitative glucose transporter in neurons. Glucose provides neurons with a critical energy source for neuronal activity. However, the mechanism by which neuronal activity controls glucose influx via GLUT3 is unknown. We investigated the influence of synaptic stimulation on GLUT3 surface expression and glucose import in primary cultured cortical and hippocampal neurons. Synaptic activity increased surface expression of GLUT3 leading to an elevation o...

  18. Do Training Programs Work? An Assessment of Pharmacists Activities in the Field of Chemical Dependency.

    Science.gov (United States)

    Brooks, Valerie G.; Brock, Tina Penick; Ahn, Jungeun

    2001-01-01

    Seeks to determine if pharmacists who attended a chemical dependency training program were performing more chemical dependency related activities. Results reveal that participants were more likely to perform the following activities: lecture to community groups about chemical dependency; participate in a pharmacists' recovery program; provide…

  19. Magnetic field dependence of vortex activation energy: A ...

    Indian Academy of Sciences (India)

    follows a parabolic behaviour unlike a power-law dependence seen in Bi2Sr2Ca2Cu3O10. ..... SP thanks Department of Science of Technology, India and SDK thanks. Council of Scientific and Industrial Research, India for financial support.

  20. Investigations on abundance and activity of microbial sponge symbionts using quantitative real - time PCR

    DEFF Research Database (Denmark)

    Kumala, Lars; Hentschel, Ute; Bayer, Kristina

    Marine sponges are hosts to dense and diverse microbial consortia that are likely to play a key role in the metabolic processes of the host sponge due to their enormous abundance. Common symbioses between nitrogen transforming microorganisms and sponges indicate complex nitrogen cycling within...... the host. Of particular interest is determining the community structure and function of microbial symbionts in order to gain deeper insight into host-symbiont interactions. We investigated the abundance and activity of microbial symbionts in two Mediterranean sponge species using quantitative real-time PCR....... An absolute quantification of functional genes and transcripts in archaeal and bacterial symbionts was conducted to determine their involvement in nitrification and denitrification, comparing the low microbial abundance (LMA) sponge Dysidea avara with the high microbial abundance (HMA) representative Aplysina...

  1. Structure modification and functionality of whey proteins: quantitative structure-activity relationship approach.

    Science.gov (United States)

    Nakai, S; Li-Chan, E

    1985-10-01

    According to the original idea of quantitative structure-activity relationship, electric, hydrophobic, and structural parameters should be taken into consideration for elucidating functionality. Changes in these parameters are reflected in the property of protein solubility upon modification of whey proteins by heating. Although solubility is itself a functional property, it has been utilized to explain other functionalities of proteins. However, better correlations were obtained when hydrophobic parameters of the proteins were used in conjunction with solubility. Various treatments reported in the literature were applied to whey protein concentrate in an attempt to obtain whipping and gelling properties similar to those of egg white. Mapping simplex optimization was used to search for the best results. Improvement in whipping properties by pepsin hydrolysis may have been due to higher protein solubility, and good gelling properties resulting from polyphosphate treatment may have been due to an increase in exposable hydrophobicity. However, the results of angel food cake making were still unsatisfactory.

  2. Antimicrobial activity of polyhexamethylene guanidine phosphate in comparison to chlorhexidine using the quantitative suspension method.

    Science.gov (United States)

    Vitt, A; Sofrata, A; Slizen, V; Sugars, R V; Gustafsson, A; Gudkova, E I; Kazeko, L A; Ramberg, P; Buhlin, K

    2015-07-17

    Polyhexamethylene guanidine phosphate (PHMG-P) belongs to the polymeric guanidine family of biocides and contains a phosphate group, which may confer better solubility, a detoxifying effect and may change the kinetics and dynamics of PHMG-P interactions with microorganisms. Limited data regarding PHMG-P activity against periodontopathogenic and cariogenic microorganisms necessitates studies in this area. Aim is to evaluate polyhexamethylene guanidine phosphate antimicrobial activity in comparison to chlorhexidine. Quantitative suspension method was used enrolling Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Streptococcus mutans and Lactobacillus acidophilus. Both tested antiseptics at their clinically-used concentrations, of 0.2% (w/v) and 1% (w/v), correspondingly provided swift bactericidal effects against S. aureus, P. aeruginosa, E. coli and C. albicans, A. actinomycetemcomitans and P. gingivalis with reduction factors higher than 6.0. Diluted polyhexamethylene guanidine phosphate and chlorhexidine to 0.05% continued to display anti-bacterial activity and decreased titers of standard quality control, periopathogens to below 1.0 × 10(3) colony forming units/ml, albeit requiring prolonged exposure time. To achieve a bactericidal effect against S. mutans, both antiseptics at all concentrations required a longer exposure time. We found that a clinically-used 1% of polyhexamethylene guanidine phosphate concentration did not have activity against L. acidophilus. High RF of polyhexamethylene guanidine phosphate and retention of bactericidal effects, even at 0.05%, support the use of polyhexamethylene guanidine phosphate as a biocide with sufficient anti-microbial activity against periopathogens. Polyhexamethylene guanidine phosphate displayed bactericidal activity against periopathogens and S. mutans and could potentially be applied in the management of oral

  3. Investigation of Antileishmanial Activities of Acridines Derivatives against Promastigotes and Amastigotes Form of Parasites Using Quantitative Structure Activity Relationship Analysis

    Directory of Open Access Journals (Sweden)

    Samir Chtita

    2016-01-01

    Full Text Available In a search of newer and potent antileishmanial (against promastigotes and amastigotes form of parasites drug, a series of 60 variously substituted acridines derivatives were subjected to a quantitative structure activity relationship (QSAR analysis for studying, interpreting, and predicting activities and designing new compounds by using multiple linear regression and artificial neural network (ANN methods. The used descriptors were computed with Gaussian 03, ACD/ChemSketch, Marvin Sketch, and ChemOffice programs. The QSAR models developed were validated according to the principles set up by the Organisation for Economic Co-operation and Development (OECD. The principal component analysis (PCA has been used to select descriptors that show a high correlation with activities. The univariate partitioning (UP method was used to divide the dataset into training and test sets. The multiple linear regression (MLR method showed a correlation coefficient of 0.850 and 0.814 for antileishmanial activities against promastigotes and amastigotes forms of parasites, respectively. Internal and external validations were used to determine the statistical quality of QSAR of the two MLR models. The artificial neural network (ANN method, considering the relevant descriptors obtained from the MLR, showed a correlation coefficient of 0.933 and 0.918 with 7-3-1 and 6-3-1 ANN models architecture for antileishmanial activities against promastigotes and amastigotes forms of parasites, respectively. The applicability domain of MLR models was investigated using simple and leverage approaches to detect outliers and outsides compounds. The effects of different descriptors in the activities were described and used to study and design new compounds with higher activities compared to the existing ones.

  4. An active form of calcium and calmodulin dependant protein kinase ...

    African Journals Online (AJOL)

    The removal of the auto-inhibitory domain that negatively regulates the kinase activity in M. truncatula results in a constitutively-active form, inducing symbiotic responses in the absence of bacterial signals. In this study, we verified the functionality of a DMI3 variant and its ability to induce spontaneous nodules in M.

  5. Quantitative detection of powdered activated carbon in wastewater treatment plant effluent by thermogravimetric analysis (TGA).

    Science.gov (United States)

    Krahnstöver, Therese; Plattner, Julia; Wintgens, Thomas

    2016-09-15

    For the elimination of potentially harmful micropollutants, powdered activated carbon (PAC) adsorption is applied in many wastewater treatment plants (WWTP). This holds the risk of PAC leakage into the WWTP effluent and desorption of contaminants into natural water bodies. In order to assess a potential PAC leakage, PAC concentrations below several mg/L have to be detected in the WWTP effluent. None of the methods that are used for water analysis today are able to differentiate between activated carbon and solid background matrix. Thus, a selective, quantitative and easily applicable method is still needed for the detection of PAC residues in wastewater. In the present study, a method was developed to quantitatively measure the PAC content in wastewater by using filtration and thermogravimetric analysis (TGA), which is a well-established technique for the distinction between different solid materials. For the sample filtration, quartz filters with a temperature stability up to 950 °C were used. This allowed for sensitive and well reproducible measurements, as the TGA was not affected by the presence of the filter. The sample's mass fractions were calculated by integrating the mass decrease rate obtained by TGA in specific, clearly identifiable peak areas. A two-step TGA heating method consisting of N2 and O2 atmospheres led to a good differentiation between PAC and biological background matrix, thanks to the reduction of peak overlapping. A linear correlation was found between a sample's PAC content and the corresponding peak areas under N2 and O2, the sample volume and the solid mass separated by filtration. Based on these findings, various wastewater samples from different WWTPs were then analyzed by TGA with regard to their PAC content. It was found that, compared to alternative techniques such as measurement of turbidity or total suspended solids, the newly developed TGA method allows for a quantitative and selective detection of PAC concentrations down to 0

  6. Evolution of the international workshops on quantitative structure-activity relationships (QSARs) in environmental toxicology.

    Science.gov (United States)

    Kaiser, K L E

    2007-01-01

    This presentation will review the evolution of the workshops from a scientific and personal perspective. From their modest beginning in 1983, the workshops have developed into larger international meetings, regularly held every two years. Their initial focus on the aquatic sphere soon expanded to include properties and effects on atmospheric and terrestrial species, including man. Concurrent with this broadening of their scientific scope, the workshops have become an important forum for the early dissemination of all aspects of qualitative and quantitative structure-activity research in ecotoxicology and human health effects. Over the last few decades, the field of quantitative structure/activity relationships (QSARs) has quickly emerged as a major scientific method in understanding the properties and effects of chemicals on the environment and human health. From substances that only affect cell membranes to those that bind strongly to a specific enzyme, QSARs provides insight into the biological effects and chemical and physical properties of substances. QSARs are useful for delineating the quantitative changes in biological effects resulting from minor but systematic variations of the structure of a compound with a specific mode of action. In addition, more holistic approaches are being devised that result in our ability to predict the effects of structurally unrelated compounds with (potentially) different modes of action. Research in QSAR environmental toxicology has led to many improvements in the manufacturing, use, and disposal of chemicals. Furthermore, it has led to national policies and international agreements, from use restrictions or outright bans of compounds, such as polychlorinated biphenyls (PCBs), mirex, and highly chlorinated pesticides (e.g. DDT, dieldrin) for the protection of avian predators, to alternatives for ozone-depleting compounds, to better waste treatment systems, to more powerful and specific acting drugs. Most of the recent advances

  7. Correlation analysis between bone density measured by quantitative CT and blood sugar level of aged patients with non-insulin-dependent diabetes mellitus

    International Nuclear Information System (INIS)

    Wang Guizhi; Liang Ping; Qiao Junhua; Liu Chunyan

    2008-01-01

    Objective: To approach the correlation between the bone density measured by quantitative CT and the blood sugar level of the aged patients with non-insulin-dependent diabetes mellitus, and observe the effects of the blood sugar level on the bone density. Methods: The lumbar bone densities and the blood sugar levels of 160 aged patients with non-insulin-dependent diabetes mellitus (hyperglycemia group 80 cases, euglycemia group 80 cases ) and the healthy aged people (80 cases) were detected by quantitative CT and serum biochemical detection; the correlation between the blood sugar level and the bone density and the osteoporosis occurrence status of aged people in various groups were analyzed. Results: The bone density in the non-insulin-dependent diabetes and hyperglycemia group was lower than those in normal (control) group and non-insulin-dependent diabetes and euglycemia group (P<0.05); the morbility of osteoporosis in the non-insulin-dependent diabetes and hyperglycemia group was higher than those in normal (control) group and non-insulin-dependent diabetes and euglycemia group (P<0.05); negative correlation was found between the bone density and the blood sugar level (aged male group: r=-0.7382, P=0.0013; aged female group: r=-0.8343, P=0.0007). Conclusion: The blood sugar level affects the bone density of the aged patients with non-insulin-dependent diabetes mellitus; the higher the blood sugar level, the lower the bone density. The non-insulin-dependent diabetes aged patients with hyperglycemia have the liability of osteoporosis. (authors)

  8. Field dependence-independence and participation in physical activity by college students.

    Science.gov (United States)

    Liu, Wenhao

    2006-06-01

    Field-independent individuals, compared with field-dependent individuals, have higher sports potential and advantages in sport-related settings. Little research, however, has been conducted on the association of field dependence-independence and participation in physical activity. The study examined this association for college students who participated in physical activities in and beyond physical education classes. The Group Embedded Figures Test distinguished 40 field-dependent from 40 field-independent participants. Activity logs during one semester showed that field-independent participants were significantly more physically active and their physical activity behaviors were more sport-related than those of field-dependent participants.

  9. Application of the quantitative autoradiography for determination of specific activity of labelled non-metallic inclusions

    International Nuclear Information System (INIS)

    Kowalczyk, J.T.; Wilczynski, A.W.

    1983-01-01

    The knowledge of specific activity of labelled non-metallic inclusions, i.e. the knowledge of the content of the radiotracer in a single inclusion, allows to obtain new information about the mechanism and the kinetics of steel deoxidation. In order to determine this specific activity quantitative autoradiography was used. Fo; this purpose, various standards of aluminium oxides with different amounts of cerium oxide Ce 2 O 3 and an aluminium-cerium alloy were prepared. The standards and the alloy were activated with thermal neutrons. Then several autoradiographs were made for these standards (ORWO AF-3 films were used). The autoradiographs served as the basis for evaluation of the standardization curves: optical density versus dimension of particles for a constant cerium concentration; optical density versus concentration of cerium for a constant dimension of particle. The samples of liquid steel were deoxidated with Al-Ce alloy. After labelled non-metallic inclusions had been isolated, the autoradiographs were made under the same conditions as for the standards. The standardization curves were used to determine the cerium content in the single inclusions. (author)

  10. Improving quantitative structure-activity relationship models using Artificial Neural Networks trained with dropout.

    Science.gov (United States)

    Mendenhall, Jeffrey; Meiler, Jens

    2016-02-01

    Dropout is an Artificial Neural Network (ANN) training technique that has been shown to improve ANN performance across canonical machine learning (ML) datasets. Quantitative Structure Activity Relationship (QSAR) datasets used to relate chemical structure to biological activity in Ligand-Based Computer-Aided Drug Discovery pose unique challenges for ML techniques, such as heavily biased dataset composition, and relatively large number of descriptors relative to the number of actives. To test the hypothesis that dropout also improves QSAR ANNs, we conduct a benchmark on nine large QSAR datasets. Use of dropout improved both enrichment false positive rate and log-scaled area under the receiver-operating characteristic curve (logAUC) by 22-46 % over conventional ANN implementations. Optimal dropout rates are found to be a function of the signal-to-noise ratio of the descriptor set, and relatively independent of the dataset. Dropout ANNs with 2D and 3D autocorrelation descriptors outperform conventional ANNs as well as optimized fingerprint similarity search methods.

  11. Quantitation of Na+, K+-atpase Enzymatic Activity in Tissues of the Mammalian Vestibular System

    Science.gov (United States)

    Kerr, T. P.

    1985-01-01

    In order to quantify vestibular Na(+), K(+)-ATPase, a microassay technique was developed which is sufficiently sensitive to measure the enzymatic activity in tissue from a single animal. The assay was used to characterize ATPase in he vestibular apparatus of the Mongolian gerbil. The quantitative procedure employs NPP (5 mM) as synthetic enzyme substrate. The assay relies upon spectrophotometric measurement (410 nm) of nitrophenol (NP) released by enzymatic hydrolysis of the substrate. Product formation in the absence of ouabain reflects both specific (Na(+), K(+)-ATPase) and non-specific (Mg(++)-ATPase) enzymatic activity. By measuring the accumulation of reaction product (NP) at three-minute intervals during the course of incubation, it is found that the overall enzymatic reaction proceeds linearly for at least 45 minutes. It is therefore possible to determine two separate reaction rates from a single set of tissues. Initial results indicate that total activity amounts to 53.3 + or - 11.2 (S.E.M.) nmol/hr/mg dry tissue, of which approximately 20% is ouabain-sensitive.

  12. Muscle activity pattern dependent pain development and alleviation.

    Science.gov (United States)

    Sjøgaard, Gisela; Søgaard, Karen

    2014-12-01

    Muscle activity is for decades considered to provide health benefits irrespectively of the muscle activity pattern performed and whether it is during e.g. sports, transportation, or occupational work tasks. Accordingly, the international recommendations for public health-promoting physical activity do not distinguish between occupational and leisure time physical activity. However, in this body of literature, attention has not been paid to the extensive documentation on occupational physical activity imposing a risk of impairment of health - in particular musculoskeletal health in terms of muscle pain. Focusing on muscle activity patterns and musculoskeletal health it is pertinent to elucidate the more specific aspects regarding exposure profiles and body regional pain. Static sustained muscle contraction for prolonged periods often occurs in the neck/shoulder area during occupational tasks and may underlie muscle pain development in spite of rather low relative muscle load. Causal mechanisms include a stereotype recruitment of low threshold motor units (activating type 1 muscle fibers) characterized by a lack of temporal as well as spatial variation in recruitment. In contrast during physical activities at leisure and sport the motor recruitment patterns are more dynamic including regularly relatively high muscle forces - also activating type 2 muscles fibers - as well as periods of full relaxation even of the type 1 muscle fibers. Such activity is unrelated to muscle pain development if adequate recovery is granted. However, delayed muscle soreness may develop following intensive eccentric muscle activity (e.g. down-hill skiing) with peak pain levels in thigh muscles 1-2 days after the exercise bout and a total recovery within 1 week. This acute pain profile is in contrast to the chronic muscle pain profile related to repetitive monotonous work tasks. The painful muscles show adverse functional, morphological, hormonal, as well as metabolic characteristics. Of

  13. Quantitatively accurate activity measurements with a dedicated cardiac SPECT camera: Physical phantom experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pourmoghaddas, Amir, E-mail: apour@ottawaheart.ca; Wells, R. Glenn [Physics Department, Carleton University, Ottawa, Ontario K1S 5B6, Canada and Cardiology, The University of Ottawa Heart Institute, Ottawa, Ontario K1Y4W7 (Canada)

    2016-01-15

    Purpose: Recently, there has been increased interest in dedicated cardiac single photon emission computed tomography (SPECT) scanners with pinhole collimation and improved detector technology due to their improved count sensitivity and resolution over traditional parallel-hole cameras. With traditional cameras, energy-based approaches are often used in the clinic for scatter compensation because they are fast and easily implemented. Some of the cardiac cameras use cadmium-zinc-telluride (CZT) detectors which can complicate the use of energy-based scatter correction (SC) due to the low-energy tail—an increased number of unscattered photons detected with reduced energy. Modified energy-based scatter correction methods can be implemented, but their level of accuracy is unclear. In this study, the authors validated by physical phantom experiments the quantitative accuracy and reproducibility of easily implemented correction techniques applied to {sup 99m}Tc myocardial imaging with a CZT-detector-based gamma camera with multiple heads, each with a single-pinhole collimator. Methods: Activity in the cardiac compartment of an Anthropomorphic Torso phantom (Data Spectrum Corporation) was measured through 15 {sup 99m}Tc-SPECT acquisitions. The ratio of activity concentrations in organ compartments resembled a clinical {sup 99m}Tc-sestamibi scan and was kept consistent across all experiments (1.2:1 heart to liver and 1.5:1 heart to lung). Two background activity levels were considered: no activity (cold) and an activity concentration 1/10th of the heart (hot). A plastic “lesion” was placed inside of the septal wall of the myocardial insert to simulate the presence of a region without tracer uptake and contrast in this lesion was calculated for all images. The true net activity in each compartment was measured with a dose calibrator (CRC-25R, Capintec, Inc.). A 10 min SPECT image was acquired using a dedicated cardiac camera with CZT detectors (Discovery NM530c, GE

  14. Localization and stretch-dependence of lung elastase activity in development and compensatory growth.

    Science.gov (United States)

    Young, Sarah Marie; Liu, Sheng; Joshi, Rashika; Batie, Matthew R; Kofron, Matthew; Guo, Jinbang; Woods, Jason C; Varisco, Brian Michael

    2015-04-01

    Synthesis and remodeling of the lung matrix is necessary for primary and compensatory lung growth. Because cyclic negative force is applied to developing lung tissue during the respiratory cycle, we hypothesized that stretch is a critical regulator of lung matrix remodeling. By using quantitative image analysis of whole-lung and whole-lobe elastin in situ zymography images, we demonstrated that elastase activity increased twofold during the alveolar stage of postnatal lung morphogenesis in the mouse. Remodeling was restricted to alveolar walls and ducts and was nearly absent in dense elastin band structures. In the mouse pneumonectomy model of compensatory lung growth, elastase activity increased threefold, peaking at 14 days postpneumonectomy and was higher in the accessory lobe compared with other lobes. Remodeling during normal development and during compensatory lung growth was different with increased major airway and pulmonary arterial remodeling during development but not regeneration, and with homogenous remodeling throughout the parenchyma during development, but increased remodeling only in subpleural regions during compensatory lung growth. Left lung wax plombage prevented increased lung elastin during compensatory lung growth. To test whether the adult lung retains an innate capacity to remodel elastin, we developed a confocal microscope-compatible stretching device. In ex vivo adult mouse lung sections, lung elastase activity increased exponentially with strain and in peripheral regions of lung more than in central regions. Our study demonstrates that lung elastase activity is stretch-dependent and supports a model in which externally applied forces influence the composition, structure, and function of the matrix during periods of alveolar septation. Copyright © 2015 the American Physiological Society.

  15. Quantitative Proteomics Reveals Temporal Proteomic Changes in Signaling Pathways during BV2 Mouse Microglial Cell Activation.

    Science.gov (United States)

    Woo, Jongmin; Han, Dohyun; Wang, Joseph Injae; Park, Joonho; Kim, Hyunsoo; Kim, Youngsoo

    2017-09-01

    The development of systematic proteomic quantification techniques in systems biology research has enabled one to perform an in-depth analysis of cellular systems. We have developed a systematic proteomic approach that encompasses the spectrum from global to targeted analysis on a single platform. We have applied this technique to an activated microglia cell system to examine changes in the intracellular and extracellular proteomes. Microglia become activated when their homeostatic microenvironment is disrupted. There are varying degrees of microglial activation, and we chose to focus on the proinflammatory reactive state that is induced by exposure to such stimuli as lipopolysaccharide (LPS) and interferon-gamma (IFN-γ). Using an improved shotgun proteomics approach, we identified 5497 proteins in the whole-cell proteome and 4938 proteins in the secretome that were associated with the activation of BV2 mouse microglia by LPS or IFN-γ. Of the differentially expressed proteins in stimulated microglia, we classified pathways that were related to immune-inflammatory responses and metabolism. Our label-free parallel reaction monitoring (PRM) approach made it possible to comprehensively measure the hyper-multiplex quantitative value of each protein by high-resolution mass spectrometry. Over 450 peptides that corresponded to pathway proteins and direct or indirect interactors via the STRING database were quantified by label-free PRM in a single run. Moreover, we performed a longitudinal quantification of secreted proteins during microglial activation, in which neurotoxic molecules that mediate neuronal cell loss in the brain are released. These data suggest that latent pathways that are associated with neurodegenerative diseases can be discovered by constructing and analyzing a pathway network model of proteins. Furthermore, this systematic quantification platform has tremendous potential for applications in large-scale targeted analyses. The proteomics data for

  16. Zinc-ion-dependent acid phosphatase exhibits magnesium-ion-dependent myo-inositol-1-phosphatase activity.

    Science.gov (United States)

    Fujimoto, S; Okano, I; Tanaka, Y; Sumida, Y; Tsuda, J; Kawakami, N; Shimohama, S

    1996-06-01

    We have purified bovine brain Zn(2+)-dependent acid phosphatase (Zn(2+)-APase), which requires Zn2+ ions to hydrolyze the substrate p-nitrophenyl phosphate (pNPP) in an acidic environment. The substrate specificity and metal requirement of Zn(2+)-APase at a physiological pH was also studied. The enzyme exhibited hydrolytic activity on myo-inositol-1- and -2-monophosphates, 2'-adenosine monophosphate, 2'-guanosine monophosphate, and the alpha- and beta-glycerophosphates, glucose-1-phosphate, and fructose-6-phosphate in 50 mM Tris-HCl buffer (pH 7.4) in the presence of Mg2+ ions, but not on pNPP and phosphotyrosine. Zn2+, Mn2+ and Co2+ ions were less effective for activation. Among the above substrates, myo-inositol-1-phosphate was the most susceptible to hydrolysis by the enzyme in the presence of 3 mM Mg2+ ions. The enzyme exhibited an optimum pH at around 8 for myo-inositol-1-phosphate in the presence of 3 mM Mg2+ ions. The Mg(2+)-dependent myo-inositol-1-phosphatase activity of the enzyme was significantly inhibited by Li+ ions. The Zn(2+)-dependent p-nitrophenyl phosphatase activity and Mg(2+)-dependent myo-inositol-1-phosphatase activity of the purified enzyme fraction exhibited similar behavior on Sephadex G-100 and Mono Q colomns. These findings suggest that Zn(2+)-APase also exhibits Mg(2+)-dependent myo-inositol-1-phosphatase activity under physiological conditions.

  17. A framework for the quantitative assessment of climate change impacts on water-related activities at the basin scale

    OpenAIRE

    Anghileri, D.; Pianosi, F.; Soncini-Sessa, R.

    2011-01-01

    While quantitative assessment of the climate change impact on hydrology at the basin scale is quite addressed in the literature, extension of quantitative analysis to impact on the ecological, economic and social sphere is still limited, although well recognized as a key issue to support water resource planning and promote public participation. In this paper we propose a framework for assessing climate change impact on water-related activities at the basin scale. The specific features of our ...

  18. Curcumin Attenuates Opioid Tolerance and Dependence by Inhibiting Ca2+/Calmodulin-Dependent Protein Kinase II α Activity

    Science.gov (United States)

    Hu, Xiaoyu; Huang, Fang; Szymusiak, Magdalena

    2015-01-01

    Chronic use of opioid analgesics has been hindered by the development of opioid addiction and tolerance. We have reported that curcumin, a natural flavonoid from the rhizome of Curcuma longa, attenuated opioid tolerance, although the underlying mechanism remains unclear. In this study, we tested the hypothesis that curcumin may inhibit Ca2+/calmodulin-dependent protein kinase II α (CaMKIIα), a protein kinase that has been previously proposed to be critical for opioid tolerance and dependence. In this study, we used state-of-the-art polymeric formulation technology to produce poly(lactic-co-glycolic acid) (PLGA)-curcumin nanoparticles (nanocurcumin) to overcome the drug’s poor solubility and bioavailability, which has made it extremely difficult for studying in vivo pharmacological actions of curcumin. We found that PLGA-curcumin nanoparticles reduced the dose requirement by 11- to 33-fold. Pretreatment with PLGA-curcumin (by mouth) prevented the development of opioid tolerance and dependence in a dose-dependent manner, with ED50 values of 3.9 and 3.2 mg/kg, respectively. PLGA-curcumin dose-dependently attenuated already-established opioid tolerance (ED50 = 12.6 mg/kg p.o.) and dependence (ED50 = 3.1 mg/kg p.o.). Curcumin or PLGA-curcumin did not produce antinociception by itself or affect morphine (1–10 mg/kg) antinociception. Moreover, we found that the behavioral effects of curcumin on opioid tolerance and dependence correlated with its inhibition of morphine-induced CaMKIIα activation in the brain. These results suggest that curcumin may attenuate opioid tolerance and dependence by suppressing CaMKIIα activity. PMID:25515789

  19. A cellular system for quantitation of vitamin K cycle activity: structure-activity effects on vitamin K antagonism by warfarin metabolites

    Science.gov (United States)

    Haque, Jamil A.; McDonald, Matthew G.; Kulman, John D.

    2014-01-01

    Warfarin and other 4-hydroxycoumarins inhibit vitamin K epoxide reductase (VKOR) by depleting reduced vitamin K that is required for posttranslational modification of vitamin K–dependent clotting factors. In vitro prediction of the in vivo potency of vitamin K antagonists is complicated by the complex multicomponent nature of the vitamin K cycle. Here we describe a sensitive assay that enables quantitative analysis of γ-glutamyl carboxylation and its antagonism in live cells. We engineered a human embryonic kidney (HEK) 293–derived cell line (HEK 293-C3) to express a chimeric protein (F9CH) comprising the Gla domain of factor IX fused to the transmembrane and cytoplasmic regions of proline-rich Gla protein 2. Maximal γ-glutamyl carboxylation of F9CH required vitamin K supplementation, and was dose-dependently inhibited by racemic warfarin at a physiologically relevant concentration. Cellular γ-glutamyl carboxylation also exhibited differential VKOR inhibition by warfarin enantiomers (S > R) consistent with their in vivo potencies. We further analyzed the structure-activity relationship for inhibition of γ-glutamyl carboxylation by warfarin metabolites, observing tolerance to phenolic substitution at the C-5 and especially C-6, but not C-7 or C-8, positions on the 4-hydroxycoumarin nucleus. After correction for in vivo concentration and protein binding, 10-hydroxywarfarin and warfarin alcohols were predicted to be the most potent inhibitory metabolites in vivo. PMID:24297869

  20. Latent transforming growth factor beta1 activation in situ: quantitative and functional evidence after low-dose gamma-irradiation

    Science.gov (United States)

    Ehrhart, E. J.; Segarini, P.; Tsang, M. L.; Carroll, A. G.; Barcellos-Hoff, M. H.; Chatterjee, A. (Principal Investigator)

    1997-01-01

    The biological activity of transforming growth factor beta1 (TGF-beta) is controlled by its secretion as a latent complex in which it is noncovalently associated with latency-associated peptide (LAP). Activation is the extracellular process in which TGF-beta is released from LAP, and is considered to be a primary regulatory control. We recently reported rapid and persistent changes in TGF-beta immunoreactivity in conjunction with extracellular matrix remodeling in gamma-irradiated mouse mammary gland. Our hypothesis is that these specific changes in immunoreactivity are indicative of latent TGF-beta activation. In the present study, we determined the radiation dose response and tested whether a functional relationship exists between radiation-induced TGF-beta and collagen type III remodeling. After radiation exposures as low as 0.1 Gy, we detected increased TGF-beta immunoreactivity in the mammary epithelium concomitant with decreased LAP immunostaining, which are events consistent with activation. Quantitative image analysis demonstrated a significant (P=0.0005) response at 0.1 Gy without an apparent threshold and a linear dose response to 5 Gy. However, in the adipose stroma, loss of LAP demonstrated a qualitative threshold at 0.5 Gy. Loss of LAP paralleled induction of collagen III immunoreactivity in this tissue compartment. We tested whether TGF-beta mediates collagen III expression by treating animals with TGF-beta panspecific monoclonal antibody, 1D11.16, administered i.p. shortly before irradiation. Radiation-induced collagen III staining in the adipose stroma was blocked in an antibody dose-dependent manner, which persisted through 7 days postirradiation. RNase protection assay revealed that radiation-induced elevation of total gland collagen III mRNA was also blocked by neutralizing antibody treatment. These data provide functional confirmation of the hypothesis that radiation exposure leads to latent TGF-beta activation, support our interpretation of the

  1. Sarcomere length-dependence of activity-dependent twitch potentiation in mouse skeletal muscle

    Directory of Open Access Journals (Sweden)

    MacIntosh Brian R

    2002-12-01

    Full Text Available Abstract Background It has been reported that potentiation of a skeletal muscle twitch response is proportional to muscle length with a negative slope during staircase, and a positive slope during posttetanic potentiation. This study was done to directly compare staircase and posttetanic responses with measurement of sarcomere length to compare their length-dependence. Methods Mouse extensor digitorum longus (EDL muscles were dissected to small bundles of fibers, which permit measurement of sarcomere length (SL, by laser diffraction. In vitro fixed-end contractions of EDL fiber bundles were elicited at 22°C and 35°C at sarcomere lengths ranging from 2.35 μm to 3.85 μm. Twitch contractions were assessed before and after 1.5 s of 75 Hz stimulation at 22°C or during 10 s of 10 Hz stimulation at 22°C or 35°C. Results Staircase potentiation was greater at 35°C than 22°C, and the relative magnitude of the twitch contraction (Pt*/Pt was proportional to sarcomere length with a negative slope, over the range 2.3 μm – 3.7 μm. Linear regression yielded the following: Pt*/Pt = -0.59·SL+3.27 (r2 = 0.74; Pt*/Pt = -0.39·SL+2.34 (r2 = 0.48; and Pt*/Pt = -0.50·SL+2.45 (r2 = 0.80 for staircase at 35°C, and 22°C and posttetanic response respectively. Posttetanic depression rather than potentiation was present at long SL. This indicates that there may be two processes operating in these muscles to modulate the force: one that enhances and a second that depresses the force. Either or both of these processes may have a length-dependence of its mechanism. Conclusion There is no evidence that posttetanic potentiation is fundamentally different from staircase in these muscles.

  2. Activity-Dependent Neurorehabilitation Beyond Physical Trainings: "Mental Exercise" Through Mirror Neuron Activation.

    Science.gov (United States)

    Yuan, Ti-Fei; Chen, Wei; Shan, Chunlei; Rocha, Nuno; Arias-Carrión, Oscar; Paes, Flávia; de Sá, Alberto Souza; Machado, Sergio

    2015-01-01

    The activity dependent brain repair mechanism has been widely adopted in many types of neurorehabilitation. The activity leads to target specific and non-specific beneficial effects in different brain regions, such as the releasing of neurotrophic factors, modulation of the cytokines and generation of new neurons in adult hood. However physical exercise program clinically are limited to some of the patients with preserved motor functions; while many patients suffered from paralysis cannot make such efforts. Here the authors proposed the employment of mirror neurons system in promoting brain rehabilitation by "observation based stimulation". Mirror neuron system has been considered as an important basis for action understanding and learning by mimicking others. During the action observation, mirror neuron system mediated the direct activation of the same group of motor neurons that are responsible for the observed action. The effect is clear, direct, specific and evolutionarily conserved. Moreover, recent evidences hinted for the beneficial effects on stroke patients after mirror neuron system activation therapy. Finally some music-relevant therapies were proposed to be related with mirror neuron system.

  3. Calcaneal Quantitative Ultrasound Indicates Reduced Bone Status Among Physically Active Adult Forager-Horticulturalists.

    Science.gov (United States)

    Stieglitz, Jonathan; Madimenos, Felicia; Kaplan, Hillard; Gurven, Michael

    2016-03-01

    Sedentary lifestyle contributes to osteoporosis and fragility fracture risks among modern humans, but whether such risks are prevalent in physically active preindustrial societies with lower life expectancies is unclear. Osteoporosis should be readily observable in preindustrial societies if it was regularly experienced over human history. In this study of 142 older adult Tsimane forager-horticulturalists (mean age ± SD, 62.1 ± 8.6 years; range, 50 to 85 years; 51% female) we used calcaneal quantitative ultrasonography (qUS) to assess bone status, document prevalence of adults with reduced bone status, and identify factors (demographic, anthropometric, immunological, kinesthetic) associated with reduced bone status. Men (23%) are as likely as women (25%) to have reduced bone status, although age-related decline in qUS parameters is attenuated for men. Adiposity and fat-free mass positively co-vary with qUS parameters for women but not men. Leukocyte count is inversely associated with qUS parameters controlling for potential confounders; leukocyte count is positively correlated within adults over time, and adults with persistently low counts have higher adjusted qUS parameters (6% to 8%) than adults with a high count. Reduced bone status characteristic of osteoporosis is common among active Tsimane with minimal exposure to osteoporosis risk factors found in industrialized societies, but with energetic constraints and high pathogen burden. © 2015 American Society for Bone and Mineral Research.

  4. Quantitative enzyme activity determination with zeptomole sensitivity by microfluidic gradient-gel zymography.

    Science.gov (United States)

    Hughes, Alex J; Herr, Amy E

    2010-05-01

    We describe a sensitive zymography technique that utilizes an automated microfluidic platform to report enzyme molecular weight, amount, and activity (including k(cat) and K(m)) from dilute protein mixtures. Calf intestinal alkaline phosphatase (CIP) is examined in detail as a model enzyme system, and the method is also demonstrated for horseradish peroxidase (HRP). The 40 min assay has a detection limit of 5 zmol ( approximately 3 000 molecules) of CIP. Two-step pore-limit electrophoresis with enzyme assay (PLENZ) is conducted in a single, straight microchannel housing a polyacrylamide (PA) pore-size gradient gel. In the first step, pore limit electrophoresis (PLE) sizes and pseudoimmobilizes resolved proteins. In the second step, electrophoresis transports both charged and neutral substrates into the PLE channel to the entrapped proteins. Arrival of substrate at the resolved enzyme band generates fluorescent product that reveals enzyme molecular weight against a fluorescent protein ladder. Additionally, the PLENZ zymography assay reports the kinetic properties of CIP in a fully quantitative manner. In contrast to covalent enzyme immobilization, physical pseudoimmobilization of CIP in the PA gel does not significantly reduce its maximum substrate turnover rate. However, an 11-fold increase in the Michaelis constant (over the free solution value) is observed, consistent with diffusional limitations on substrate access to the enzyme active site. PLENZ offers a robust platform for rapid and multiplexed functional analysis of heterogeneous protein samples in drug discovery, clinical diagnostics, and biocatalyst engineering.

  5. Comparison of quantitative EEG characteristics of quiet and active sleep in newborns.

    Science.gov (United States)

    Paul, Karel; Krajca, Vladimír; Roth, Zdenek; Melichar, Jan; Petránek, Svojmil

    2003-11-01

    The aim of the present study was to verify whether the proposed method of computer-supported EEG analysis is able to differentiate the EEG activity in quiet sleep (QS) from that in active sleep (AS) in newborns. A quantitative description of the neonatal EEG may contribute to a more exact evaluation of the functional state of the brain, as well as to a refinement of diagnostics of brain dysfunction manifesting itself frequently as 'dysrhythmia' or 'dysmaturity'. Twenty-one healthy newborns (10 full-term and 11 pre-term) were examined polygraphically (EEG-eight channels, respiration, ECG, EOG and EMG) in the course of sleep. From each EEG record, two 5-min samples (one from QS and one from AS) were subject to an off-line computerized analysis. The obtained data were averaged with respect to the sleep state and to the conceptional age. The number of variables was reduced by means of factor analysis. All factors identified by factor analysis were highly significantly influenced by sleep states in both developmental periods. Likewise, a comparison of the measured variables between QS and AS revealed many statistically significant differences. The variables describing (a) the number and length of quasi-stationary segments, (b) voltage and (c) power in delta and theta bands contributed to the greatest degree to the differentiation of EEGs between both sleep states. The presented method of the computerized EEG analysis which has good discriminative potential is adequately sensitive and describes the neonatal EEG with convenient accuracy.

  6. Quantitative Secretome Analysis of Activated Jurkat Cells Using Click Chemistry-Based Enrichment of Secreted Glycoproteins.

    Science.gov (United States)

    Witzke, Kathrin E; Rosowski, Kristin; Müller, Christian; Ahrens, Maike; Eisenacher, Martin; Megger, Dominik A; Knobloch, Jürgen; Koch, Andrea; Bracht, Thilo; Sitek, Barbara

    2017-01-06

    Quantitative secretome analyses are a high-performance tool for the discovery of physiological and pathophysiological changes in cellular processes. However, serum supplements in cell culture media limit secretome analyses, but serum depletion often leads to cell starvation and consequently biased results. To overcome these limiting factors, we investigated a model of T cell activation (Jurkat cells) and performed an approach for the selective enrichment of secreted proteins from conditioned medium utilizing metabolic marking of newly synthesized glycoproteins. Marked glycoproteins were labeled via bioorthogonal click chemistry and isolated by affinity purification. We assessed two labeling compounds conjugated with either biotin or desthiobiotin and the respective secretome fractions. 356 proteins were quantified using the biotin probe and 463 using desthiobiotin. 59 proteins were found differentially abundant (adjusted p-value ≤0.05, absolute fold change ≥1.5) between inactive and activated T cells using the biotin method and 86 using the desthiobiotin approach, with 31 mutual proteins cross-verified by independent experiments. Moreover, we analyzed the cellular proteome of the same model to demonstrate the benefit of secretome analyses and provide comprehensive data sets of both. 336 proteins (61.3%) were quantified exclusively in the secretome. Data are available via ProteomeXchange with identifier PXD004280.

  7. Odor-active constituents in fresh pineapple (Ananas comosus [L.] Merr.) by quantitative and sensory evaluation.

    Science.gov (United States)

    Tokitomo, Yukiko; Steinhaus, Martin; Büttner, Andrea; Schieberle, Peter

    2005-07-01

    By application of aroma extract dilution analysis (AEDA) to an aroma distillate prepared from fresh pineapple using solvent-assisted flavor evaporation (SAFE), 29 odor-active compounds were detected in the flavor dilution (FD) factor range of 2 to 4,096. Quantitative measurements performed by stable isotope dilution assays (SIDA) and a calculation of odor activity values (OAVs) of 12 selected odorants revealed the following compounds as key odorants in fresh pineapple flavor: 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDF; sweet, pineapple-like, caramel-like), ethyl 2-methylpropanoate (fruity), ethyl 2-methylbutanoate (fruity) followed by methyl 2-methylbutanoate (fruity, apple-like) and 1-(E,Z)-3,5-undecatriene (fresh, pineapple-like). A mixture of these 12 odorants in concentrations equal to those in the fresh pineapple resulted in an odor profile similar to that of the fresh juice. Furthermore, the results of omission tests using the model mixture showed that HDF and ethyl 2-methylbutanoate are character impact odorants in fresh pineapple.

  8. Incorporating Nondrug Social & Recreational Activities in Outpatient Chemical Dependency Treatment

    Science.gov (United States)

    Siporin, Sheldon; Baron, Lisa

    2012-01-01

    "Contingency Management programs (CMP) and non-drug social and recreational activities (NDSRA) are interventions premised on behavior theory that rely on external sources of reinforcement alternative to drug-based forms to decrease drug use. CMP usually employs vouchers as reinforcement for negative toxicologies. Despite research support, CMP…

  9. Energy dependence on the electric activities of a neuron

    International Nuclear Information System (INIS)

    Song Xin-Lin; Ma Jun; Jin Wu-Yin

    2015-01-01

    A nonlinear circuit can be designed by using inductor, resistor, capacitor and other electric devices, and the electromagnetic field energy can be released from the circuit in the oscillating state. The generation of spikes or bursting states in neurons could be energetically a costly process. Based on the Helmholtz’s theorem, a Hamilton energy function is defined to detect the energy shift induced by transition of electric modes in a Hindmarsh–Rose neuron. It is found that the energy storage is dependent on the external forcing, and energy release is associated with the electric mode. As a result, the bursting state and chaotic state could be helpful to release the energy in the neuron quickly. (paper)

  10. On-Beads Digestion in Conjunction with Data-Dependent Mass Spectrometry: A Shortcut to Quantitative and Dynamic Interaction Proteomics

    Directory of Open Access Journals (Sweden)

    Benedetta Turriziani

    2014-04-01

    Full Text Available With the advent of the “-omics” era, biological research has shifted from functionally analyzing single proteins to understanding how entire protein networks connect and adapt to environmental cues. Frequently, pathological processes are initiated by a malfunctioning protein network rather than a single protein. It is therefore crucial to investigate the regulation of proteins in the context of a pathway first and signaling network second. In this study, we demonstrate that a quantitative interaction proteomic approach, combining immunoprecipitation, in-solution digestion and label-free quantification mass spectrometry, provides data of high accuracy and depth. This protocol is applicable, both to tagged, exogenous and untagged, endogenous proteins. Furthermore, it is fast, reliable and, due to a label-free quantitation approach, allows the comparison of multiple conditions. We further show that we are able to generate data in a medium throughput fashion and that we can quantify dynamic interaction changes in signaling pathways in response to mitogenic stimuli, making our approach a suitable method to generate data for system biology approaches.

  11. Impact of the Qualitative and Quantitative Aspects of Human Activity on the Ecosystem: Demonstration through the Use of Ecological Footprint Approach

    Directory of Open Access Journals (Sweden)

    Makram GAALICHE

    2012-12-01

    Full Text Available This article aims to show that the impact of human activities on the ecosystem, measured by the Ecological Footprint, depends on the qualitative and quantitative aspects of the population. Indeed, we confirmed our hypothesis by an empirical analysis on Tunisia, where it was revealed that the increase in its Ecological Footprint, is attributed mainly to massive consumption of goods, bad land management by building horizontal, and to a lesser extent, to the presence of polluting employments. The results suggest the adoption of targeted policies, according to the specific characteristics of population.

  12. Nicotine dependence matters: examining longitudinal association between smoking and physical activity among Canadian adults.

    Science.gov (United States)

    Azagba, Sunday; Asbridge, Mark

    2013-11-01

    A number of studies point to the inverse relationship between physical activity and smoking; however, none has examined the role of nicotine dependence in physical activity participation among smokers. This study examined whether levels of nicotine dependence modify the association between leisure time physical activity and smoking status. The study used longitudinal data on 6795 adults from the Canadian National Population Health Survey (2004-2010). Generalized estimating equations were used to examine the association between physical activity, smoking, and nicotine dependence. We found that nicotine dependent smokers were significantly less likely to be physically active compared to non-smokers. Specifically, using the Fagerstrom Test for Nicotine Dependence, nicotine dependent smokers (OR 0.65, 95% CI 0.55-0.76) were less likely to be physically active while no significant difference was found for non-dependent smokers (OR 0.90, 95% CI 0.80-1.02) compared to non-smokers. Nicotine dependence matters in shaping engagement in physical activity among daily smokers. Efforts directed at promoting smoking cessation through nicotine dependence treatment intervention may provide additional benefits to health and well-being through an increased participation in physical activity. © 2013.

  13. The Political Consequences of Resource Dependence - How Natural Gas Export Can Affect Policy Outcomes: A Quantitative Analysis

    Directory of Open Access Journals (Sweden)

    Øistein Breiland Harsem

    2011-12-01

    Full Text Available With the use of a liberal/rational framework as a baseline, this article examines whether economic asymmetric interdependence can yield political influence. More specifically, it examines exogenous gas supply to the EU and develops a theory that provides testable hypotheses aiming to answer whether the export of gas provides political advantages for the sender state. The outlined hypotheses, and more, are tested in a cross sectional time series dataset, where votes in the United Nations (UN Assembly are used as the dependent variable, as a measurement for the policy preferences of states. The empirical findings support the prediction made in the theory section. Gas dependence has a conditional effect on policy behaviour. The sender government has to be a sizeable international power, whilst the recipient government should have low military capabilities and be dependent on foreign support.

  14. Vitamin K dependent protein activity and incident ischemic cardiovascular disease: The multi ethnic study of atherosclerosis

    Science.gov (United States)

    OBJECTIVE: Vitamin K-dependent proteins (VKDPs), which require post-translational modification to achieve biological activity, seem to contribute to thrombus formation, vascular calcification, and vessel stiffness. Whether VKDP activity is prospectively associated with incident cardiovascular diseas...

  15. Expression of MMPs is dependent on the activity of mitogen-activated protein kinase in chondrosarcoma.

    Science.gov (United States)

    Yao, Min; Wang, Xiaomei; Zhao, Yufeng; Wang, Xiaomeng; Gao, Feng

    2017-02-01

    Matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) serve an important role in chondrosarcoma. The present study investigated whether the expression of MMPs was dependent on the activity of mitogen-activated protein kinase (MAPK) in chondrosarcoma. Surgical pathological specimens were collected to detect MMP-1, MMP-13, TIMP-1, type II collagen and phosphorylated MAPK levels in normal cartilage, enchondroma and chondrosarcoma tissues. The expression of MMP‑1, MMP‑13, TIMP‑1 and type II collagen was investigated utilizing MAPK inhibitors in chondrosarcoma cells. It was noted that the expression levels of MMP‑1, MMP‑13 and TIMP‑1 were increased in chondrosarcoma with the activity of MAPK. After chondrosarcoma cells were pretreated with MAPK inhibitors, the levels of MMP‑1, MMP‑13 and TIMP‑1 were inhibited. Furthermore, MMP‑1 and MMP‑13 are essential in regulating the degradation of type II collagen and decomposing cartilage matrix major. The high expression levels of MMP‑1 and MMP‑13 in chondrosarcoma expedite the invasion by chondrosarcoma cells and their expression can be depressed by MAPK inhibitors.

  16. Nuclear cGMP-dependent kinase regulates gene expression via activity-dependent recruitment of a conserved histone deacetylase complex.

    Directory of Open Access Journals (Sweden)

    Yan Hao

    2011-05-01

    Full Text Available Elevation of the second messenger cGMP by nitric oxide (NO activates the cGMP-dependent protein kinase PKG, which is key in regulating cardiovascular, intestinal, and neuronal functions in mammals. The NO-cGMP-PKG signaling pathway is also a major therapeutic target for cardiovascular and male reproductive diseases. Despite widespread effects of PKG activation, few molecular targets of PKG are known. We study how EGL-4, the Caenorhabditis elegans PKG ortholog, modulates foraging behavior and egg-laying and seeks the downstream effectors of EGL-4 activity. Using a combination of unbiased forward genetic screen and proteomic analysis, we have identified a conserved SAEG-1/SAEG-2/HDA-2 histone deacetylase complex that is specifically recruited by activated nuclear EGL-4. Gene expression profiling by microarrays revealed >40 genes that are sensitive to EGL-4 activity in a SAEG-1-dependent manner. We present evidence that EGL-4 controls egg laying via one of these genes, Y45F10C.2, which encodes a novel protein that is expressed exclusively in the uterine epithelium. Our results indicate that, in addition to cytoplasmic functions, active EGL-4/PKG acts in the nucleus via a conserved Class I histone deacetylase complex to regulate gene expression pertinent to behavioral and physiological responses to cGMP. We also identify transcriptional targets of EGL-4 that carry out discrete components of the physiological response.

  17. Thickness Dependent on Photocatalytic Activity of Hematite Thin Films

    Directory of Open Access Journals (Sweden)

    Yen-Hua Chen

    2012-01-01

    Full Text Available Hematite (Fe2O3 thin films with different thicknesses are fabricated by the rf magnetron sputtering deposition. The effects of film thicknesses on the photocatalytic activity of hematite films have been investigated. Hematite films possess a polycrystalline hexagonal structure, and the band gap decreases with an increase of film thickness. Moreover, all hematite films exhibit good photocatalytic ability under visible-light irradiation; the photocatalytic activity of hematite films increases with the increasing film thickness. This is because the hematite film with a thicker thickness has a rougher surface, providing more reaction sites for photocatalysis. Another reason is a lower band gap of a hematite film would generate more electron-hole pairs under visible-light illumination to enhance photocatalytic efficiency. Experimental data are well fitted with Langmuir-Hinshelwood kinetic model. The photocatalytic rate constant of hematite films ranges from 0.052 to 0.068 min-1. This suggests that the hematite film is a superior photocatalyst under visible-light irradiation.

  18. Spontaneous appetence for wheel-running: a model of dependency on physical activity in rat.

    Science.gov (United States)

    Ferreira, Anthony; Lamarque, Stéphanie; Boyer, Patrice; Perez-Diaz, Fernando; Jouvent, Roland; Cohen-Salmon, Charles

    2006-12-01

    According to human observations of a syndrome of physical activity dependence and its consequences, we tried to examine if running activity in a free activity paradigm, where rats had a free access to activity wheel, may present a valuable animal model for physical activity dependence and most generally to behavioral dependence. The pertinence of reactivity to novelty, a well-known pharmacological dependence predictor was also tested. Given the close linkage observed in human between physical activity and drugs use and abuse, the influence of free activity in activity wheels on reactivity to amphetamine injection and reactivity to novelty were also assessed. It appeared that (1) free access to wheel may be used as a valuable model for physical activity addiction, (2) two populations differing in activity amount also differed in dependence to wheel-running. (3) Reactivity to novelty did not appeared as a predictive factor for physical activity dependence (4) activity modified novelty reactivity and (5) subjects who exhibited a high appetence to wheel-running, presented a strong reactivity to amphetamine. These results propose a model of dependency on physical activity without any pharmacological intervention, and demonstrate the existence of individual differences in the development of this addiction. In addition, these data highlight the development of a likely vulnerability to pharmacological addiction after intense and sustained physical activity, as also described in man. This model could therefore prove pertinent for studying behavioral dependencies and the underlying neurobiological mechanisms. These results may influence the way psychiatrists view behavioral dependencies and phenomena such as doping in sport or addiction to sport itself.

  19. Quantitative simulation of intracellular signaling cascades in a Virtual Liver: estimating dose dependent changes in hepatocellular proliferation and apoptosis

    Science.gov (United States)

    The US EPA Virtual Liver (v-Liver™) is developing an approach to predict dose-dependent hepatotoxicity as an in vivo tissue level response using in vitro data. The v-Liver accomplishes this using an in silico agent-based systems model that dynamically integrates environmental exp...

  20. The effect of volume-of-interest misregistration on quantitative planar activity and dose estimation

    International Nuclear Information System (INIS)

    Song, N; Frey, E C; He, B

    2010-01-01

    In targeted radionuclide therapy (TRT), dose estimation is essential for treatment planning and tumor dose response studies. Dose estimates are typically based on a time series of whole-body conjugate view planar or SPECT scans of the patient acquired after administration of a planning dose. Quantifying the activity in the organs from these studies is an essential part of dose estimation. The quantitative planar (QPlanar) processing method involves accurate compensation for image degrading factors and correction for organ and background overlap via the combination of computational models of the image formation process and 3D volumes of interest defining the organs to be quantified. When the organ VOIs are accurately defined, the method intrinsically compensates for attenuation, scatter and partial volume effects, as well as overlap with other organs and the background. However, alignment between the 3D organ volume of interest (VOIs) used in QPlanar processing and the true organ projections in the planar images is required. The aim of this research was to study the effects of VOI misregistration on the accuracy and precision of organ activity estimates obtained using the QPlanar method. In this work, we modeled the degree of residual misregistration that would be expected after an automated registration procedure by randomly misaligning 3D SPECT/CT images, from which the VOI information was derived, and planar images. Mutual information-based image registration was used to align the realistic simulated 3D SPECT images with the 2D planar images. The residual image misregistration was used to simulate realistic levels of misregistration and allow investigation of the effects of misregistration on the accuracy and precision of the QPlanar method. We observed that accurate registration is especially important for small organs or ones with low activity concentrations compared to neighboring organs. In addition, residual misregistration gave rise to a loss of precision

  1. Quantitation of microbicidal activity of mononuclear phagocytes: an in vitro technique.

    Directory of Open Access Journals (Sweden)

    Rege N

    1993-01-01

    Full Text Available An in vitro assay technique was set up to determine the phagocytic and microbicidal activity of a monocyte-macrophage cell line using Candida species as test organisms. The norms were determined for the activity of peritoneal macrophages of rats (24.69 +/- 2.6% phagocytosis and 35.4 +/- 5.22% ICK and human (27.89 +/- 3.63% phagocytosis and 50.91 +/- 6.3% ICK. The assay technique was used to test the degree of activation of macrophages induced by metronidazole, Tinospora cordifolia and Asparaqus racemousus and to compare their effects with a standard immunomodulator muramyl-dipeptide. All the three test agents increased the phagocytic and killing capacity of macrophages in a dose dependent manner upto a certain dose, beyond which either these activities were found to have plateaued or decreased. The optimal doses for MDP, Metronidazole, Asparagus racemosus and Tinospora cordifolia were found to be 100 micrograms, 300 mg/kg, 200 mg/kg and 100 mg/kg respectively. Patients with cirrhosis were screened for defects in monocyte function. The depressed monocyte function (20.58 +/- 5% phago and 41.24 +/- 12.19% ICK; P < 0.05 was observed indicating a compromised host defense. The utility of this candidicidal assay in experimental and clinical studies is discussed.

  2. DREAM-Dependent Activation of Astrocytes in Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Larrodé, Pilar; Calvo, Ana Cristina; Moreno-Martínez, Laura; de la Torre, Miriam; Moreno-García, Leticia; Molina, Nora; Castiella, Tomás; Iñiguez, Cristina; Pascual, Luis Fernando; Mena, Francisco Javier Miana; Zaragoza, Pilar; Y Cajal, Santiago Ramón; Osta, Rosario

    2018-01-01

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of unknown origin and characterized by a relentless loss of motor neurons that causes a progressive muscle weakness until death. Among the several pathogenic mechanisms that have been related to ALS, a dysregulation of calcium-buffering proteins in motor neurons of the brain and spinal cord can make these neurons more vulnerable to disease progression. Downstream regulatory element antagonist modulator (DREAM) is a neuronal calcium-binding protein that plays multiple roles in the nucleus and cytosol. The main aim of this study was focused on the characterization of DREAM and glial fibrillary acid protein (GFAP) in the brain and spinal cord tissues from transgenic SOD1 G93A mice and ALS patients to unravel its potential role under neurodegenerative conditions. The DREAM and GFAP levels in the spinal cord and different brain areas from transgenic SOD1 G93A mice and ALS patients were analyzed by Western blot and immunohistochemistry. Our findings suggest that the calcium-dependent excitotoxicity progressively enhanced in the CNS in ALS could modulate the multifunctional nature of DREAM, strengthening its apoptotic way of action in both motor neurons and astrocytes, which could act as an additional factor to increase neuronal damage. The direct crosstalk between astrocytes and motor neurons can become vulnerable under neurodegenerative conditions, and DREAM could act as an additional switch to enhance motor neuron loss. Together, these findings could pave the way to further study the molecular targets of DREAM to find novel therapeutic strategies to fight ALS.

  3. Dose-dependent pharmacokinetics and teratogenic activity of topical retinoids

    International Nuclear Information System (INIS)

    Sharma, R.P.; Willhite, C.C.; Berry, D.L.; Allen, P.V.

    1990-01-01

    Oral retinoid treatment can be teratogenic and topical applications are used to treat acne and smooth wrinkles. A single topical trace (2.5 μg; 191 μCi/kg) or high (1.3 mg; 195 μCi/kg) dose of all-trans-[10, 11- 3 H 2 ] retinoic acid (RA) dissolved in acetone was applied to 4 cm 2 shaved dorsal hamster skin. Peak plasma radioactivity (C max ) occurred at 12 and 36 hr and mean t1/2 values for parent PA absorption were 48 min and 2.8 hr, for trace and high dose, respectively. The dermal RA C max values were only 2% of that after an equivalent oral dose, but plasma AUC after dermal treatment was 63% of the oral value. The mean t1/2 for rapid elimination was shorter for the high (57 min) than for the trace (6.9 hr) dose, but t1/2 values for slow elimination were comparable (t1/2 high = 51.2 hr; t1/2 trace = 36.8 hr). Single topical application of 10-30 mg/kg RA or 5 mg/kg etretinate (Ro 10-9359) to pregnant hamsters (day 8) caused local hyperkeratosis, but failed to induce terata. Similar application of 10-1000 μg/kg arotinoid Ro 13-6298 caused dose-dependent terata, being twice as embryolethal by parenteral as enteric dosing. Skin toxicity and attenuated maternal blood levels limit the amount of retinoids that can reach the embryo

  4. Time-dependent relative activities in the radioactive families

    International Nuclear Information System (INIS)

    Wiernik, M.

    1976-01-01

    The relative activities of the members of the principal radioactive families, with respect to the initial activities of chosen parents were calculated for a wide range of time intervals. Tables ard graphs that are useful for radiochemistry, source standardization and chronology are presented.Three series of graphs and tables are included; series A corresponds to the family 4n, series B corresponds to the family 4n+ x, series C corresponds to the family 4n+2. A foustry, source standardization and chronology are presented. rth series 4n+1 ( 241 Pu/ 209 Bi) was not included, because it does not exist in nature and, thus, is of little interest. Each series begins with a table identified by a plain letter (A,B,C) where all the nuclides considered for the calculations and their half-lives are listed. Branching was neglected. All the series begin with isotopes of plutonium in order to show some examples of no-equilibrium, and five of the longest lived members of each family were chosen as the parents of the sub-families. The graphs show that, besides their obvious use in radiochemical separations and standardizations, each family beginning with a naturally occuring nuclide has a particular time span (before secular equilibrium occurs) that can be used for chronology. Thus, if the proper radionuclides are present, we can use the wide range families in geological and archeological research and the short range ones in other kinds of jobs, like checking the authenticity of art masterpieces and other forensic problems. (T.G.)

  5. The uridine diphosphate glucuronosyltransferases: quantitative structure-activity relationships for hydroxyl polychlorinated biphenyl substrates

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Degao [Dalian University of Technology, Department of Environmental Science and Technology, Dalian (China)

    2005-10-01

    Quantitative structure-activity relationships (QSARs), which relate the glucuronidation of hydroxyl polychlorinated biphenyls (OH-PCBs) - catalyzed by the uridine diphosphate glucuronosyltransferases (UGTs) - to their physicochemical properties and molecular structural parameters, can be used to predict the rate constants and interpret the mechanism of glucuronidation. In this study, QSARs have been developed that use 23 semi-empirical calculated quantum chemical descriptors to predict the logarithms of the constants 1/K{sub m} and V{sub max}, related to enzyme kinetics. A partial least squares regression method was used to select the optimal set of descriptors to minimize the multicollinearity between the descriptors, as well as to maximize the cross-validated coefficient (Q{sup 2} {sub cum}) values. The key descriptors affecting log(1/K{sub m}) were E{sub lumo}- E{sub homo} (the energy gap between the lowest unoccupied molecular orbital and the highest occupied molecular orbital) and q{sub C}{sup -} (the largest negative net atomic charge on a carbon atom), while the key descriptors affecting log V{sub max} were the polarizability {alpha}, the Connolly solvent-excluded volume (CSEV), and logP (the logarithm of the partition coefficient for octanol/water). From the results obtained it can be concluded that hydrophobic and electronic aspects of OH-PCBs are important in the glucuronidation of OH-PCBs. (orig.)

  6. Quantitative Structure--Activity Relationship (QSAR) for the Oxidation of Trace Organic Contaminants by Sulfate Radical.

    Science.gov (United States)

    Xiao, Ruiyang; Ye, Tiantian; Wei, Zongsu; Luo, Shuang; Yang, Zhihui; Spinney, Richard

    2015-11-17

    The sulfate radical anion (SO4•–) based oxidation of trace organic contaminants (TrOCs) has recently received great attention due to its high reactivity and low selectivity. In this study, a meta-analysis was conducted to better understand the role of functional groups on the reactivity between SO4•– and TrOCs. The results indicate that compounds in which electron transfer and addition channels dominate tend to exhibit a faster second-order rate constants (kSO4•–) than that of H–atom abstraction, corroborating the SO4•– reactivity and mechanisms observed in the individual studies. Then, a quantitative structure activity relationship (QSAR) model was developed using a sequential approach with constitutional, geometrical, electrostatic, and quantum chemical descriptors. Two descriptors, ELUMO and EHOMO energy gap (ELUMO–EHOMO) and the ratio of oxygen atoms to carbon atoms (#O:C), were found to mechanistically and statistically affect kSO4•– to a great extent with the standardized QSAR model: ln kSO4•– = 26.8–3.97 × #O:C – 0.746 × (ELUMO–EHOMO). In addition, the correlation analysis indicates that there is no dominant reaction channel for SO4•– reactions with various structurally diverse compounds. Our QSAR model provides a robust predictive tool for estimating emerging micropollutants removal using SO4•– during wastewater treatment processes.

  7. Quantitative Structure activity relationship and risk analysis of some pesticides in the cattle milk

    Directory of Open Access Journals (Sweden)

    Faqir Muhammad*, Ijaz Javed, Masood Akhtar1, Zia-ur-Rahman, Mian Muhammad Awais1, Muhammad Kashif Saleemi2 and Muhammad Irfan Anwar3

    2012-10-01

    Full Text Available Milk of cattle was collected from various localities of Faisalabad, Pakistan. Pesticides concentration was determined by HPLC using solid phase microextraction. The residue analysis revealed that about 40% milk samples were contaminated with pesticides. The mean±SE levels (ppm of cyhalothrin, endosulfan, chlorpyrifos and cypermethrin were 0.38±0.02, 0.26±0.02, 0.072±0.01 and 0.085±0.02, respectively. Quantitative structure activity relationship (QSAR models were used to predict the residues of unknown pesticides in the milk of cattle using their known physicochemical properties such as molecular weight (MW, melting point (MP, and log octanol to water partition coefficient (Ko/w as well as the milk characteristics such as pH, % fat, and specific gravity (SG in this species. The analysis revealed good correlation coefficients (R2 = 0.91 for cattle QSAR model. The coefficient for Ko/w for the studied pesticides was higher in cattle milk. Risk analysis was conducted based upon the determined pesticide residues and their provisional tolerable daily intakes. The daily intake levels of pesticide residues including cyhalothrin, chlorpyrifos and cypermethrin in present study were 3, 11, 2.5 times higher, respectively in cattle milk. This intake of pesticide contaminated milk might pose health hazards to humans in this locality.

  8. Quantitation of the receptor for urokinase plasminogen activator by enzyme-linked immunosorbent assay

    DEFF Research Database (Denmark)

    Rønne, E; Behrendt, N; Ploug, M

    1994-01-01

    variant of uPAR, suPAR, has been constructed by recombinant technique and the protein content of a purified suPAR standard preparation was determined by amino acid composition analysis. The sensitivity of the assay (0.6 ng uPAR/ml) is strong enough to measure uPAR in extracts of cultured cells and cancer......Binding of the urokinase plasminogen activator (uPA) to a specific cell surface receptor (uPAR) plays a crucial role in proteolysis during tissue remodelling and cancer invasion. An immunosorbent assay for the quantitation of uPAR has now been developed. This assay is based on two monoclonal...... antibodies recognizing the non-ligand binding part of this receptor, and it detects both free and occupied uPAR, in contrast to ligand-binding assays used previously. In a variant of the assay, the occupied fraction of uPAR is selectively detected with a uPA antibody. To be used as a standard, a soluble...

  9. Quantitative structure-activity relationships for green algae growth inhibition by polymer particles.

    Science.gov (United States)

    Nolte, Tom M; Peijnenburg, Willie J G M; Hendriks, A Jan; van de Meent, Dik

    2017-07-01

    After use and disposal of chemical products, many types of polymer particles end up in the aquatic environment with potential toxic effects to primary producers like green algae. In this study, we have developed Quantitative Structure-Activity Relationships (QSARs) for a set of highly structural diverse polymers which are capable to estimate green algae growth inhibition (EC50). The model (N = 43, R 2  = 0.73, RMSE = 0.28) is a regression-based decision tree using one structural descriptor for each of three polymer classes separated based on charge. The QSAR is applicable to linear homo polymers as well as copolymers and does not require information on the size of the polymer particle or underlying core material. Highly branched polymers, non-nitrogen cationic polymers and polymeric surfactants are not included in the model and thus cannot be evaluated. The model works best for cationic and non-ionic polymers for which cellular adsorption, disruption of the cell wall and photosynthesis inhibition were the mechanisms of action. For anionic polymers, specific properties of the polymer and test characteristics need to be known for detailed assessment. The data and QSAR results for anionic polymers, when combined with molecular dynamics simulations indicated that nutrient depletion is likely the dominant mode of toxicity. Nutrient depletion in turn, is determined by the non-linear interplay between polymer charge density and backbone flexibility. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Deep neural nets as a method for quantitative structure-activity relationships.

    Science.gov (United States)

    Ma, Junshui; Sheridan, Robert P; Liaw, Andy; Dahl, George E; Svetnik, Vladimir

    2015-02-23

    Neural networks were widely used for quantitative structure-activity relationships (QSAR) in the 1990s. Because of various practical issues (e.g., slow on large problems, difficult to train, prone to overfitting, etc.), they were superseded by more robust methods like support vector machine (SVM) and random forest (RF), which arose in the early 2000s. The last 10 years has witnessed a revival of neural networks in the machine learning community thanks to new methods for preventing overfitting, more efficient training algorithms, and advancements in computer hardware. In particular, deep neural nets (DNNs), i.e. neural nets with more than one hidden layer, have found great successes in many applications, such as computer vision and natural language processing. Here we show that DNNs can routinely make better prospective predictions than RF on a set of large diverse QSAR data sets that are taken from Merck's drug discovery effort. The number of adjustable parameters needed for DNNs is fairly large, but our results show that it is not necessary to optimize them for individual data sets, and a single set of recommended parameters can achieve better performance than RF for most of the data sets we studied. The usefulness of the parameters is demonstrated on additional data sets not used in the calibration. Although training DNNs is still computationally intensive, using graphical processing units (GPUs) can make this issue manageable.

  11. Quantitative structure activity relationship for the computational prediction of nitrocompounds carcinogenicity

    International Nuclear Information System (INIS)

    Morales, Aliuska Helguera; Perez, Miguel Angel Cabrera; Combes, Robert D.; Gonzalez, Maykel Perez

    2006-01-01

    Several nitrocompounds have been screened for carcinogenicity in rodents, but this is a lengthy and expensive process, taking two years and typically costing 2.5 million dollars, and uses large numbers of animals. There is, therefore, much impetus to develop suitable alternative methods. One possible way of predicting carcinogenicity is to use quantitative structure-activity relationships (QSARs). QSARs have been widely utilized for toxicity testing, thereby contributing to a reduction in the need for experimental animals. This paper describes the results of applying a TOPological substructural molecular design (TOPS-MODE) approach for predicting the rodent carcinogenicity of nitrocompounds. The model described 79.10% of the experimental variance, with a standard deviation of 0.424. The predictive power of the model was validated by leave-one-out validation, with a determination coefficient of 0.666. In addition, this approach enabled the contribution of different fragments to carcinogenic potency to be assessed, thereby making the relationships between structure and carcinogenicity to be transparent. It was found that the carcinogenic activity of the chemicals analysed was increased by the presence of a primary amine group bonded to the aromatic ring, a manner that was proportional to the ring aromaticity. The nitro group bonded to an aromatic carbon atom is a more important determinant of carcinogenicity than the nitro group bonded to an aliphatic carbon. Finally, the TOPS-MODE approach was compared with four other predictive models, but none of these could explain more than 66% of the variance in the carcinogenic potency with the same number of variables

  12. Calculated viscosity-distance dependence for some actively flowing lavas

    International Nuclear Information System (INIS)

    Pieri, D.

    1987-01-01

    The importance of viscosity as a gauge of the various energy and momentum dissipation regimes of lava flows has been realized for a long time. Nevertheless, despite its central role in lava dynamics and kinematics, it remains among the most difficult of flow physical properties to measure in situ during an eruption. Attempts at reconstructing the actual emplacement viscosities of lava flows from their solidified topographic form are difficult. Where data are available on the position of an advancing flow front as a function of time, it is possible to calculate the effective viscosity of the front as a function of distance from the vent, under the assumptions of a steady state regime. As an application and test of an equation given, relevant parameters from five recent flows on Mauna Loa and Kilauea were utilized to infer the dynamic structure of their aggregate flow front viscosity as they advanced, up to cessation. The observed form of the viscosity-distance relation for the five active Hawaiian flows examined appears to be exponential, with a rapid increase just before the flows stopped as one would expect

  13. Dampened STING-Dependent Interferon Activation in Bats.

    Science.gov (United States)

    Xie, Jiazheng; Li, Yang; Shen, Xurui; Goh, Geraldine; Zhu, Yan; Cui, Jie; Wang, Lin-Fa; Shi, Zheng-Li; Zhou, Peng

    2018-03-14

    Compared with terrestrial mammals, bats have a longer lifespan and greater capacity to co-exist with a variety of viruses. In addition to cytosolic DNA generated by these viral infections, the metabolic demands of flight cause DNA damage and the release of self-DNA into the cytoplasm. However, whether bats have an altered DNA sensing/defense system to balance high cytosolic DNA levels remains an open question. We demonstrate that bats have a dampened interferon response due to the replacement of the highly conserved serine residue (S358) in STING, an essential adaptor protein in multiple DNA sensing pathways. Reversing this mutation by introducing S358 restored STING functionality, resulting in interferon activation and virus inhibition. Combined with previous reports on bat-specific changes of other DNA sensors such as TLR9, IFI16, and AIM2, our findings shed light on bat adaptation to flight, their long lifespan, and their unique capacity to serve as a virus reservoir. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Quantitative structure-activity relationship analysis of substituted arylazo pyridone dyes in photocatalytic system: Experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Dostanić, J., E-mail: jasmina@nanosys.ihtm.bg.ac.rs [University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Catalysis and Chemical Engineering, Njegoševa 12, 11000 Belgrade (Serbia); Lončarević, D. [University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Catalysis and Chemical Engineering, Njegoševa 12, 11000 Belgrade (Serbia); Zlatar, M. [University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Chemistry, Njegoševa 12, 11000 Belgrade (Serbia); Vlahović, F. [University of Belgrade, Innovation center of the Faculty of Chemistry, 11000 Belgrade (Serbia); Jovanović, D.M. [University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Catalysis and Chemical Engineering, Njegoševa 12, 11000 Belgrade (Serbia)

    2016-10-05

    Highlights: • Electronic effects of para substituted arylazo pyridone dyes. • Linear relationship between Hammett σ{sub p} constants and dyes photoreactivity. • The photocatalytic reactions facilitated by el.-acceptors and retarded by el.-donors. • Fukui functions to analyze the reactivity on concurrent sites within a molecule. • Hydroxyl radicals sustain attack from two reaction sites, depending on a substituent type. - Abstract: A series of arylazo pyridone dyes was synthesized by changing the type of the substituent group in the diazo moiety, ranging from strong electron-donating to strong electron-withdrawing groups. The structural and electronic properties of the investigated dyes was calculated at the M062X/6-31 + G(d,p) level of theory. The observed good linear correlations between atomic charges and Hammett σ{sub p} constants provided a basis to discuss the transmission of electronic substituent effects through a dye framework. The reactivity of synthesized dyes was tested through their decolorization efficiency in TiO{sub 2} photocatalytic system (Degussa P-25). Quantitative structure-activity relationship analysis revealed a strong correlation between reactivity of investigated dyes and Hammett substituent constants. The reaction was facilitated by electron-withdrawing groups, and retarded by electron-donating ones. Quantum mechanical calculations was used in order to describe the mechanism of the photocatalytic oxidation reactions of investigated dyes and interpret their reactivities within the framework of the Density Functional Theory (DFT). According to DFT based reactivity descriptors, i.e. Fukui functions and local softness, the active site moves from azo nitrogen atom linked to benzene ring to pyridone carbon atom linked to azo bond, going from dyes with electron-donating groups to dyes with electron-withdrawing groups.

  15. Target and Tissue Selectivity Prediction by Integrated Mechanistic Pharmacokinetic-Target Binding and Quantitative Structure Activity Modeling.

    Science.gov (United States)

    Vlot, Anna H C; de Witte, Wilhelmus E A; Danhof, Meindert; van der Graaf, Piet H; van Westen, Gerard J P; de Lange, Elizabeth C M

    2017-12-04

    Selectivity is an important attribute of effective and safe drugs, and prediction of in vivo target and tissue selectivity would likely improve drug development success rates. However, a lack of understanding of the underlying (pharmacological) mechanisms and availability of directly applicable predictive methods complicates the prediction of selectivity. We explore the value of combining physiologically based pharmacokinetic (PBPK) modeling with quantitative structure-activity relationship (QSAR) modeling to predict the influence of the target dissociation constant (K D ) and the target dissociation rate constant on target and tissue selectivity. The K D values of CB1 ligands in the ChEMBL database are predicted by QSAR random forest (RF) modeling for the CB1 receptor and known off-targets (TRPV1, mGlu5, 5-HT1a). Of these CB1 ligands, rimonabant, CP-55940, and Δ 8 -tetrahydrocanabinol, one of the active ingredients of cannabis, were selected for simulations of target occupancy for CB1, TRPV1, mGlu5, and 5-HT1a in three brain regions, to illustrate the principles of the combined PBPK-QSAR modeling. Our combined PBPK and target binding modeling demonstrated that the optimal values of the K D and k off for target and tissue selectivity were dependent on target concentration and tissue distribution kinetics. Interestingly, if the target concentration is high and the perfusion of the target site is low, the optimal K D value is often not the lowest K D value, suggesting that optimization towards high drug-target affinity can decrease the benefit-risk ratio. The presented integrative structure-pharmacokinetic-pharmacodynamic modeling provides an improved understanding of tissue and target selectivity.

  16. Quantitative structure-activity relationship analysis of substituted arylazo pyridone dyes in photocatalytic system: Experimental and theoretical study

    International Nuclear Information System (INIS)

    Dostanić, J.; Lončarević, D.; Zlatar, M.; Vlahović, F.; Jovanović, D.M.

    2016-01-01

    Highlights: • Electronic effects of para substituted arylazo pyridone dyes. • Linear relationship between Hammett σ_p constants and dyes photoreactivity. • The photocatalytic reactions facilitated by el.-acceptors and retarded by el.-donors. • Fukui functions to analyze the reactivity on concurrent sites within a molecule. • Hydroxyl radicals sustain attack from two reaction sites, depending on a substituent type. - Abstract: A series of arylazo pyridone dyes was synthesized by changing the type of the substituent group in the diazo moiety, ranging from strong electron-donating to strong electron-withdrawing groups. The structural and electronic properties of the investigated dyes was calculated at the M062X/6-31 + G(d,p) level of theory. The observed good linear correlations between atomic charges and Hammett σ_p constants provided a basis to discuss the transmission of electronic substituent effects through a dye framework. The reactivity of synthesized dyes was tested through their decolorization efficiency in TiO_2 photocatalytic system (Degussa P-25). Quantitative structure-activity relationship analysis revealed a strong correlation between reactivity of investigated dyes and Hammett substituent constants. The reaction was facilitated by electron-withdrawing groups, and retarded by electron-donating ones. Quantum mechanical calculations was used in order to describe the mechanism of the photocatalytic oxidation reactions of investigated dyes and interpret their reactivities within the framework of the Density Functional Theory (DFT). According to DFT based reactivity descriptors, i.e. Fukui functions and local softness, the active site moves from azo nitrogen atom linked to benzene ring to pyridone carbon atom linked to azo bond, going from dyes with electron-donating groups to dyes with electron-withdrawing groups.

  17. New insights into the mechanisms of acetic acid resistance in Acetobacter pasteurianus using iTRAQ-dependent quantitative proteomic analysis.

    Science.gov (United States)

    Xia, Kai; Zang, Ning; Zhang, Junmei; Zhang, Hong; Li, Yudong; Liu, Ye; Feng, Wei; Liang, Xinle

    2016-12-05

    Acetobacter pasteurianus is the main starter in rice vinegar manufacturing due to its remarkable abilities to resist and produce acetic acid. Although several mechanisms of acetic acid resistance have been proposed and only a few effector proteins have been identified, a comprehensive depiction of the biological processes involved in acetic acid resistance is needed. In this study, iTRAQ-based quantitative proteomic analysis was adopted to investigate the whole proteome of different acidic titers (3.6, 7.1 and 9.3%, w/v) of Acetobacter pasteurianus Ab3 during the vinegar fermentation process. Consequently, 1386 proteins, including 318 differentially expressed proteins (p150 proteins were differentially expressed. Specifically, proteins involved in amino acid metabolic processes and fatty acid biosynthesis were differentially expressed, which may contribute to the acetic acid resistance of Acetobacter. Transcription factors, two component systems and toxin-antitoxin systems were implicated in the modulatory network at multiple levels. In addition, the identification of proteins involved in redox homeostasis, protein metabolism, and the cell envelope suggested that the whole cellular system is mobilized in response to acid stress. These findings provide a differential proteomic profile of acetic acid resistance in Acetobacter pasteurianus and have potential application to highly acidic rice vinegar manufacturing. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Quantitative analysis with advanced compensated polarized light microscopy on wavelength dependence of linear birefringence of single crystals causing arthritis

    Science.gov (United States)

    Takanabe, Akifumi; Tanaka, Masahito; Taniguchi, Atsuo; Yamanaka, Hisashi; Asahi, Toru

    2014-07-01

    To improve our ability to identify single crystals causing arthritis, we have developed a practical measurement system of polarized light microscopy called advanced compensated polarized light microscopy (A-CPLM). The A-CPLM system is constructed by employing a conventional phase retardation plate, an optical fibre and a charge-coupled device spectrometer in a polarized light microscope. We applied the A-CPLM system to measure linear birefringence (LB) in the visible region, which is an optical anisotropic property, for tiny single crystals causing arthritis, i.e. monosodium urate monohydrate (MSUM) and calcium pyrophosphate dihydrate (CPPD). The A-CPLM system performance was evaluated by comparing the obtained experimental data using the A-CPLM system with (i) literature data for a standard sample, MgF2, and (ii) experimental data obtained using an established optical method, high-accuracy universal polarimeter, for the MSUM. The A-CPLM system was found to be applicable for measuring the LB spectra of the single crystals of MSUM and CPPD, which cause arthritis, in the visible regions. We quantitatively reveal the large difference in LB between MSUM and CPPD crystals. These results demonstrate the usefulness of the A-CPLM system for distinguishing the crystals causing arthritis.

  19. ACTIVATION REACTION ON THE ELECTROENCEPHALOGRAM IN SUBSTANCE DEPENDENT PATIENTS: LINKS TO ADDICTION STUDIES AND PSYCHOLOGICAL FACTORS AND CHANGES IN NEUROFEEDBACK TRAINING

    Directory of Open Access Journals (Sweden)

    M. e Melnikov

    2014-01-01

    Full Text Available Depth of activation reaction (α-activity suppression during the eyes-opening task is considered to be an important quantitative characteristic of α-band brainwaves. Activation reaction was assessed from O1 and O2 leads in 31 male substance dependent subjects. In 7 cases it was measured twice: before and after α- or β-brainwave biofeedback training. The correlations were found between grade of α suppression in eyes-opening task and attitude towards disease and treatment, personality maturity, and level of pathological personality traits. Activation reaction was significantly improved by α-training and non-significantly diminished after β-1-training.

  20. A Review of Recent Advances towards the Development of (Quantitative) Structure-Activity Relationships for Metallic Nanomaterials.

    NARCIS (Netherlands)

    Chen, Guangchao; Vijver, Martina G; Xiao, Yinlong; Peijnenburg, Willie J G M

    2017-01-01

    Gathering required information in a fast and inexpensive way is essential for assessing the risks of engineered nanomaterials (ENMs). The extension of conventional (quantitative) structure-activity relationships ((Q)SARs) approach to nanotoxicology, i.e., nano-(Q)SARs, is a possible solution. The

  1. Quantitative structure-activity relationship modeling of the toxicity of organothiophosphate pesticides to Daphnia magna and Cyprinus carpio

    NARCIS (Netherlands)

    Zvinavashe, E.; Du, T.; Griff, T.; Berg, van den J.H.J.; Soffers, A.E.M.F.; Vervoort, J.J.M.; Murk, A.J.; Rietjens, I.

    2009-01-01

    Within the REACH regulatory framework in the EU, quantitative structure-activity relationships (QSAR) models are expected to help reduce the number of animals used for experimental testing. The objective of this study was to develop QSAR models to describe the acute toxicity of organothiophosphate

  2. Quantitative PET of human urokinase-type plasminogen activator receptor with 64Cu-DOTA-AE105

    DEFF Research Database (Denmark)

    Persson, Morten; Madsen, Jacob; Østergaard, Søren

    2012-01-01

    Expression levels of the urokinase-type plasminogen activator receptor (uPAR) represent an established biomarker for poor prognosis in a variety of human cancers. The objective of the present study was to explore whether noninvasive PET can be used to perform a quantitative assessment of expressi...

  3. Comparative Analysis of Predictive Models for Liver Toxicity Using ToxCast Assays and Quantitative Structure-Activity Relationships (MCBIOS)

    Science.gov (United States)

    Comparative Analysis of Predictive Models for Liver Toxicity Using ToxCast Assays and Quantitative Structure-Activity Relationships Jie Liu1,2, Richard Judson1, Matthew T. Martin1, Huixiao Hong3, Imran Shah1 1National Center for Computational Toxicology (NCCT), US EPA, RTP, NC...

  4. Transgenerational propagation and quantitative maintenance of paternal centromeres depends on Cid/Cenp-A presence in Drosophila sperm.

    Directory of Open Access Journals (Sweden)

    Nitika Raychaudhuri

    Full Text Available In Drosophila melanogaster, as in many animal and plant species, centromere identity is specified epigenetically. In proliferating cells, a centromere-specific histone H3 variant (CenH3, named Cid in Drosophila and Cenp-A in humans, is a crucial component of the epigenetic centromere mark. Hence, maintenance of the amount and chromosomal location of CenH3 during mitotic proliferation is important. Interestingly, CenH3 may have different roles during meiosis and the onset of embryogenesis. In gametes of Caenorhabditis elegans, and possibly in plants, centromere marking is independent of CenH3. Moreover, male gamete differentiation in animals often includes global nucleosome for protamine exchange that potentially could remove CenH3 nucleosomes. Here we demonstrate that the control of Cid loading during male meiosis is distinct from the regulation observed during the mitotic cycles of early embryogenesis. But Cid is present in mature sperm. After strong Cid depletion in sperm, paternal centromeres fail to integrate into the gonomeric spindle of the first mitosis, resulting in gynogenetic haploid embryos. Furthermore, after moderate depletion, paternal centromeres are unable to re-acquire normal Cid levels in the next generation. We conclude that Cid in sperm is an essential component of the epigenetic centromere mark on paternal chromosomes and it exerts quantitative control over centromeric Cid levels throughout development. Hence, the amount of Cid that is loaded during each cell cycle appears to be determined primarily by the preexisting centromeric Cid, with little flexibility for compensation of accidental losses.

  5. Active ion transport in the renal proximal tubule. II. Ionic dependence of the Na pump

    OpenAIRE

    1984-01-01

    The dependence of Na pump activity on intracellular and extracellular Na+ and K+ was investigated using a suspension of rabbit cortical tubules that contained mostly (86%) proximal tubules. The ouabain- sensitive rate of respiration (QO2) was used to measure the Na pump activity of intact tubules, and the Na,K-ATPase hydrolytic activity was measured using lysed proximal tubule membranes. The dependence (K0.5) of the Na pump on intracellular Na+ was affected by the relative intracellular conce...

  6. Puerarin activates endothelial nitric oxide synthase through estrogen receptor-dependent PI3-kinase and calcium-dependent AMP-activated protein kinase

    International Nuclear Information System (INIS)

    Hwang, Yong Pil; Kim, Hyung Gyun; Hien, Tran Thi; Jeong, Myung Ho; Jeong, Tae Cheon; Jeong, Hye Gwang

    2011-01-01

    The cardioprotective properties of puerarin, a natural product, have been attributed to the endothelial nitric oxide synthase (eNOS)-mediated production of nitric oxide (NO) in EA.hy926 endothelial cells. However, the mechanism by which puerarin activates eNOS remains unclear. In this study, we sought to identify the intracellular pathways underlying eNOS activation by puerarin. Puerarin induced the activating phosphorylation of eNOS on Ser1177 and the production of NO in EA.hy926 cells. Puerarin-induced eNOS phosphorylation required estrogen receptor (ER)-mediated phosphatidylinositol 3-kinase (PI3K)/Akt signaling and was reversed by AMP-activated protein kinase (AMPK) and calcium/calmodulin-dependent kinase II (CaMKII) inhibition. Importantly, puerarin inhibited the adhesion of tumor necrosis factor (TNF)-α-stimulated monocytes to endothelial cells and suppressed the TNF-α induced expression of intercellular cell adhesion molecule-1. Puerarin also inhibited the TNF-α-induced nuclear factor-κB activation, which was attenuated by pretreatment with N G -nitro-L-arginine methyl ester, a NOS inhibitor. These results indicate that puerarin stimulates eNOS phosphorylation and NO production via activation of an estrogen receptor-mediated PI3K/Akt- and CaMKII/AMPK-dependent pathway. Puerarin may be useful for the treatment or prevention of endothelial dysfunction associated with diabetes and cardiovascular disease. -- Highlights: ► Puerarin induced the phosphorylation of eNOS and the production of NO. ► Puerarin activated eNOS through ER-dependent PI3-kinase and Ca 2+ -dependent AMPK. ► Puerarin-induced NO was involved in the inhibition of NF-kB activation. ► Puerarin may help for prevention of vascular dysfunction and diabetes.

  7. Puerarin activates endothelial nitric oxide synthase through estrogen receptor-dependent PI3-kinase and calcium-dependent AMP-activated protein kinase

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Yong Pil; Kim, Hyung Gyun [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of); Hien, Tran Thi [College of Pharmacy, Chosun University, Gwangju (Korea, Republic of); Jeong, Myung Ho [Heart Research Center, Chonnam National University Hospital, Gwangju (Korea, Republic of); Jeong, Tae Cheon, E-mail: taecheon@ynu.ac.kr [College of Pharmacy, Yeungnam University, Gyungsan (Korea, Republic of); Jeong, Hye Gwang, E-mail: hgjeong@cnu.ac.kr [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of)

    2011-11-15

    The cardioprotective properties of puerarin, a natural product, have been attributed to the endothelial nitric oxide synthase (eNOS)-mediated production of nitric oxide (NO) in EA.hy926 endothelial cells. However, the mechanism by which puerarin activates eNOS remains unclear. In this study, we sought to identify the intracellular pathways underlying eNOS activation by puerarin. Puerarin induced the activating phosphorylation of eNOS on Ser1177 and the production of NO in EA.hy926 cells. Puerarin-induced eNOS phosphorylation required estrogen receptor (ER)-mediated phosphatidylinositol 3-kinase (PI3K)/Akt signaling and was reversed by AMP-activated protein kinase (AMPK) and calcium/calmodulin-dependent kinase II (CaMKII) inhibition. Importantly, puerarin inhibited the adhesion of tumor necrosis factor (TNF)-{alpha}-stimulated monocytes to endothelial cells and suppressed the TNF-{alpha} induced expression of intercellular cell adhesion molecule-1. Puerarin also inhibited the TNF-{alpha}-induced nuclear factor-{kappa}B activation, which was attenuated by pretreatment with N{sup G}-nitro-L-arginine methyl ester, a NOS inhibitor. These results indicate that puerarin stimulates eNOS phosphorylation and NO production via activation of an estrogen receptor-mediated PI3K/Akt- and CaMKII/AMPK-dependent pathway. Puerarin may be useful for the treatment or prevention of endothelial dysfunction associated with diabetes and cardiovascular disease. -- Highlights: Black-Right-Pointing-Pointer Puerarin induced the phosphorylation of eNOS and the production of NO. Black-Right-Pointing-Pointer Puerarin activated eNOS through ER-dependent PI3-kinase and Ca{sup 2+}-dependent AMPK. Black-Right-Pointing-Pointer Puerarin-induced NO was involved in the inhibition of NF-kB activation. Black-Right-Pointing-Pointer Puerarin may help for prevention of vascular dysfunction and diabetes.

  8. Quantitative analysis of contrast-enhanced ultrasonography of the bowel wall can predict disease activity in inflammatory bowel disease

    Energy Technology Data Exchange (ETDEWEB)

    Romanini, Laura, E-mail: laura.romanini@libero.it [Department of Radiology, Spedali Civili di Brescia, P.le Spedali Civili, 1, 25123 Brescia (Italy); Passamonti, Matteo, E-mail: matteopassamonti@gmail.com [Department of Radiology-AO Provincia di Lodi, Via Fissiraga, 15, 26900 Lodi (Italy); Navarria, Mario, E-mail: navarria.mario@tiscali.it [Department of Radiology-ASL Vallecamonica-Sebino, Via Manzoni 142, 25040 Esine, BS (Italy); Lanzarotto, Francesco, E-mail: francesco.lanzarotto@spedalicivili.brescia.it [Department of Gastroenterology, Spedali Civili di Brescia, P.le Spedali Civili, 1, 25123 Brescia (Italy); Villanacci, Vincenzo, E-mail: villanac@alice.it [Department of Pathology, Spedali Civili di Brescia, P.le Spedali Civili, 1, 25123 Brescia (Italy); Grazioli, Luigi, E-mail: radiologia1@spedalicivili.brescia.it [Department of Radiology, Spedali Civili di Brescia, P.le Spedali Civili, 1, 25123 Brescia (Italy); Calliada, Fabrizio, E-mail: fabrizio.calliada@gmail.com [Department of Radiology, University of Pavia, Viale Camillo Golgi 19, 27100 Pavia (Italy); Maroldi, Roberto, E-mail: rmaroldi@gmail.com [Department of Radiology, University of Brescia, P.le Spedali Civili, 1, 25123 Brescia (Italy)

    2014-08-15

    Purpose: To evaluate the accuracy of quantitative analysis of bowel wall enhancement in inflammatory bowel disease (IBD) with contrast enhanced ultrasound (CEUS) by comparing the results with vascular density in a biopsy sample from the same area of the intestinal tract, and to determine the usefulness of this analysis for the prediction of disease activity. Materials and methods: This prospective study was approved by our institute's ethics committee and all patients gave written informed consent. We enrolled 33 consecutive adult patients undergoing colonoscopy and biopsy for IBD. All patients underwent CEUS and the results were quantitatively analyzed. Vessel count per high-power field on biopsy specimens was compared with colonoscopy, baseline ultrasonography, and CEUS findings, and with analysis of peak intensity, time to peak, regional blood volume, mean transit time, and regional blood flow. Results in patients with high and low vascular density were compared using Fisher's test, t-test, Pearson's correlation test, and receiver operating characteristic curve (ROC) analysis. Cutoff values were determined using ROC analysis, and sensitivity and specificity were calculated. Results: High vascular density (>265 vessels per field) on histological examination was significantly correlated with active disease on colonoscopy, baseline ultrasonography, and CEUS (p < .0001). Quantitative analysis showed a higher enhancement peak, a shorter time to peak enhancement, a higher regional blood flow and regional blood volume in patients with high vascular density than in those with low vascular density. Cutoff values to distinguish between active and inactive disease were identified for peak enhancement (>40.5%), and regional blood flow (>54.8 ml/min). Conclusion: Quantitative analysis of CEUS data correlates with disease activity as determined by vascular density. Quantitative parameters of CEUS can be used to predict active disease with high sensitivity and

  9. Quantitative analysis of contrast-enhanced ultrasonography of the bowel wall can predict disease activity in inflammatory bowel disease

    International Nuclear Information System (INIS)

    Romanini, Laura; Passamonti, Matteo; Navarria, Mario; Lanzarotto, Francesco; Villanacci, Vincenzo; Grazioli, Luigi; Calliada, Fabrizio; Maroldi, Roberto

    2014-01-01

    Purpose: To evaluate the accuracy of quantitative analysis of bowel wall enhancement in inflammatory bowel disease (IBD) with contrast enhanced ultrasound (CEUS) by comparing the results with vascular density in a biopsy sample from the same area of the intestinal tract, and to determine the usefulness of this analysis for the prediction of disease activity. Materials and methods: This prospective study was approved by our institute's ethics committee and all patients gave written informed consent. We enrolled 33 consecutive adult patients undergoing colonoscopy and biopsy for IBD. All patients underwent CEUS and the results were quantitatively analyzed. Vessel count per high-power field on biopsy specimens was compared with colonoscopy, baseline ultrasonography, and CEUS findings, and with analysis of peak intensity, time to peak, regional blood volume, mean transit time, and regional blood flow. Results in patients with high and low vascular density were compared using Fisher's test, t-test, Pearson's correlation test, and receiver operating characteristic curve (ROC) analysis. Cutoff values were determined using ROC analysis, and sensitivity and specificity were calculated. Results: High vascular density (>265 vessels per field) on histological examination was significantly correlated with active disease on colonoscopy, baseline ultrasonography, and CEUS (p < .0001). Quantitative analysis showed a higher enhancement peak, a shorter time to peak enhancement, a higher regional blood flow and regional blood volume in patients with high vascular density than in those with low vascular density. Cutoff values to distinguish between active and inactive disease were identified for peak enhancement (>40.5%), and regional blood flow (>54.8 ml/min). Conclusion: Quantitative analysis of CEUS data correlates with disease activity as determined by vascular density. Quantitative parameters of CEUS can be used to predict active disease with high sensitivity and

  10. Toxicity of ionic liquids: Database and prediction via quantitative structure–activity relationship method

    International Nuclear Information System (INIS)

    Zhao, Yongsheng; Zhao, Jihong; Huang, Ying; Zhou, Qing; Zhang, Xiangping; Zhang, Suojiang

    2014-01-01

    Highlights: • A comprehensive database on toxicity of ionic liquids (ILs) was established. • Relationship between structure and toxicity of IL has been analyzed qualitatively. • Two new QSAR models were developed for predicting toxicity of ILs to IPC-81. • Accuracy of proposed nonlinear SVM model is much higher than the linear MLR model. • The established models can be explored in designing novel green agents. - Abstract: A comprehensive database on toxicity of ionic liquids (ILs) is established. The database includes over 4000 pieces of data. Based on the database, the relationship between IL's structure and its toxicity has been analyzed qualitatively. Furthermore, Quantitative Structure–Activity relationships (QSAR) model is conducted to predict the toxicities (EC 50 values) of various ILs toward the Leukemia rat cell line IPC-81. Four parameters selected by the heuristic method (HM) are used to perform the studies of multiple linear regression (MLR) and support vector machine (SVM). The squared correlation coefficient (R 2 ) and the root mean square error (RMSE) of training sets by two QSAR models are 0.918 and 0.959, 0.258 and 0.179, respectively. The prediction R 2 and RMSE of QSAR test sets by MLR model are 0.892 and 0.329, by SVM model are 0.958 and 0.234, respectively. The nonlinear model developed by SVM algorithm is much outperformed MLR, which indicates that SVM model is more reliable in the prediction of toxicity of ILs. This study shows that increasing the relative number of O atoms of molecules leads to decrease in the toxicity of ILs

  11. Quantitative structure activity relationship and risk analysis of some pesticides in the goat milk.

    Science.gov (United States)

    Muhammad, Faqir; Awais, Mian Muhammad; Akhtar, Masood; Anwar, Muhammad Irfan

    2013-01-04

    The detection and quantification of different pesticides in the goat milk samples collected from different localities of Faisalabad, Pakistan was performed by HPLC using solid phase microextraction. The analysis showed that about 50% milk samples were contaminated with pesticides. The mean±SEM levels (ppm) of cyhalothrin, endosulfan, chlorpyrifos and cypermethrin were 0.34±0.007, 0.063±0.002, 0.034±0.002 and 0.092±0.002, respectively; whereas, methyl parathion was not detected in any of the analyzed samples. Quantitative structure activity relationship (QSAR) models were suggested to predict the residues of unknown pesticides in the goat milk using their known physicochemical characteristics including molecular weight (MW), melting point (MP), and log octanol to water partition coefficient (Ko/w) in relation to the characteristics such as pH, % fat, specific gravity and refractive index of goat milk. The analysis revealed good correlation coefficient (R2 = 0.985) for goat QSAR model. The coefficients for Ko/w and refractive index for the studied pesticides were higher in goat milk. This suggests that these are better determinants for pesticide residue prediction in the milk of these animals. Based upon the determined pesticide residues and their provisional tolerable daily intakes, risk analysis was also conducted which showed that daily intake levels of pesticide residues including cyhalothrin, chlorpyrifos and cypermethrin in present study are 2.68, 5.19 and 2.71 times higher, respectively in the goat milk. This intake of pesticide contaminated milk might pose health hazards to humans in this locality.

  12. Quantitative Structure Activity Relationship and Risk Analysis of Some Pesticides in the Goat milk

    Directory of Open Access Journals (Sweden)

    Faqir Muhammad

    2013-01-01

    Full Text Available The detection and quantification of different pesticides in the goat milk samples collected from different localities of Faisalabad, Pakistan was performed by HPLC using solid phase microextraction. The analysis showed that about 50% milk samples were contaminated with pesticides. The mean+/-SEM levels (ppm of cyhalothrin, endosulfan, chlorpyrifos and cypermethrin were 0.34+/-0.007, 0.063+/-0.002, 0.034+/-0.002 and 0.092+/-0.002, respectively; whereas, methyl parathion was not detected in any of the analyzed samples. Quantitative structure activity relationship (QSAR models were suggested to predict the residues of unknown pesticides in the goat milk using their known physicochemical characteristics including molecular weight (MW, melting point (MP, and log octanol to water partition coefficient (Ko/w in relation to the characteristics such as pH, % fat, specific gravity and refractive index of goat milk. The analysis revealed good correlation coefficient (R2 = 0.985 for goat QSAR model. The coefficients for Ko/w and refractive index for the studied pesticides were higher in goat milk. This suggests that these are better determinants for pesticide residue prediction in the milk of these animals. Based upon the determined pesticide residues and their provisional tolerable daily intakes, risk analysis was also conducted which showed that daily intake levels of pesticide residues including cyhalothrin, chlorpyrifos and cypermethrin in present study are 2.68, 5.19 and 2.71 times higher, respectively in the goat milk. This intake of pesticide contaminated milk might pose health hazards to humans in this locality.

  13. Angle-dependent XPS study of the mechanisms of 'high-low temperature' activation of GaAs photocathode

    International Nuclear Information System (INIS)

    Du Xiaoqing; Chang Benkang

    2005-01-01

    The surface chemical compositions, atomic concentration percentage and layer thickness after 'high-temperature' single-step activation and 'high-low temperature' two-step activation were obtained using quantitative analysis of angle-dependent X-ray photoelectron spectroscopy (XPS). It was found that compared to single-step activation, the thickness of GaAs-O interface barrier had a remarkable decrease, the degree of As-O bond became much smaller and the Ga-O bond became dominating, and at the same time the thickness of (Cs, O) layer also had a deduction while the ratio of Cs to O had no change after two-step activation. The measured spectral response curves showed that a increase of 29% of sensitivity had been obtained after two-step activation. To explore the inherent mechanisms of influences of the evolution of GaAs(Cs, O) surface layers on photoemission, surface electric barrier models based on the experimental results were built. By calculation of electron escape probability it was found that the decrease of thickness of GaAs-O interface barrier and (Cs, O) layer is the main reasons, which explained why higher sensitivity is achieved after two-step activation than single-step activation

  14. Quantitative DNA methylation analyses reveal stage dependent DNA methylation and association to clinico-pathological factors in breast tumors

    International Nuclear Information System (INIS)

    Klajic, Jovana; Tost, Jörg; Kristensen, Vessela N; Fleischer, Thomas; Dejeux, Emelyne; Edvardsen, Hege; Warnberg, Fredrik; Bukholm, Ida; Lønning, Per Eystein; Solvang, Hiroko; Børresen-Dale, Anne-Lise

    2013-01-01

    Aberrant DNA methylation of regulatory genes has frequently been found in human breast cancers and correlated to clinical outcome. In the present study we investigate stage specific changes in the DNA methylation patterns in order to identify valuable markers to understand how these changes affect breast cancer progression. Quantitative DNA methylation analyses of 12 candidate genes ABCB1, BRCCA1, CDKN2A, ESR1, GSTP1, IGF2, MGMT, HMLH1, PPP2R2B, PTEN, RASSF1A and FOXC1 was performed by pyrosequencing a series of 238 breast cancer tissue samples from DCIS to invasive tumors stage I to IV. Significant differences in methylation levels between the DCIS and invasive stage II tumors were observed for six genes RASSF1A, CDKN2A, MGMT, ABCB1, GSTP1 and FOXC1. RASSF1A, ABCB1 and GSTP1 showed significantly higher methylation levels in late stage compared to the early stage breast carcinoma. Z-score analysis revealed significantly lower methylation levels in DCIS and stage I tumors compared with stage II, III and IV tumors. Methylation levels of PTEN, PPP2R2B, FOXC1, ABCB1 and BRCA1 were lower in tumors harboring TP53 mutations then in tumors with wild type TP53. Z-score analysis showed that TP53 mutated tumors had significantly lower overall methylation levels compared to tumors with wild type TP53. Methylation levels of RASSF1A, PPP2R2B, GSTP1 and FOXC1 were higher in ER positive vs. ER negative tumors and methylation levels of PTEN and CDKN2A were higher in HER2 positive vs. HER2 negative tumors. Z-score analysis also showed that HER2 positive tumors had significantly higher z-scores of methylation compared to the HER2 negative tumors. Univariate survival analysis identifies methylation status of PPP2R2B as significant predictor of overall survival and breast cancer specific survival. In the present study we report that the level of aberrant DNA methylation is higher in late stage compared with early stage of invasive breast cancers and DCIS for genes mentioned above

  15. Chemical Variability and Biological Activities of Brassica rapa var. rapifera Parts Essential Oils Depending on Geographic Variation and Extraction Technique.

    Science.gov (United States)

    Saka, Boualem; Djouahri, Abderrahmane; Djerrad, Zineb; Terfi, Souhila; Aberrane, Sihem; Sabaou, Nasserdine; Baaliouamer, Aoumeur; Boudarene, Lynda

    2017-06-01

    In the present work, the Brassica rapa var. rapifera parts essential oils and their antioxidant and antimicrobial activities were investigated for the first time depending on geographic origin and extraction technique. Gas-chromatography (GC) and GC/mass spectrometry (MS) analyses showed several constituents, including alcohols, aldehydes, esters, ketones, norisoprenoids, terpenic, nitrogen and sulphur compounds, totalizing 38 and 41 compounds in leaves and root essential oils, respectively. Nitrogen compounds were the main volatiles in leaves essential oils and sulphur compounds were the main volatiles in root essential oils. Qualitative and quantitative differences were found among B. rapa var. rapifera parts essential oils collected from different locations and extracted by hydrodistillation and microwave-assisted hydrodistillation techniques. Furthermore, our findings showed a high variability for both antioxidant and antimicrobial activities. The highlighted variability reflects the high impact of plant part, geographic variation and extraction technique on chemical composition and biological activities, which led to conclude that we should select essential oils to be investigated carefully depending on these factors, in order to isolate the bioactive components or to have the best quality of essential oil in terms of biological activities and preventive effects in food. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  16. Shape-dependent guidance of active Janus particles by chemically patterned surfaces

    Science.gov (United States)

    Uspal, W. E.; Popescu, M. N.; Tasinkevych, M.; Dietrich, S.

    2018-01-01

    Self-phoretic chemically active Janus particles move by inducing—via non-equilibrium chemical reactions occurring on their surfaces—changes in the chemical composition of the solution in which they are immersed. This process leads to gradients in chemical composition along the surface of the particle, as well as along any nearby boundaries, including solid walls. Chemical gradients along a wall can give rise to chemi-osmosis, i.e., the gradients drive surface flows which, in turn, drive flow in the volume of the solution. This bulk flow couples back to the particle, and thus contributes to its self-motility. Since chemi-osmosis strongly depends on the molecular interactions between the diffusing molecular species and the wall, the response flow induced and experienced by a particle encodes information about any chemical patterning of the wall. Here, we extend previous studies on self-phoresis of a sphere near a chemically patterned wall to the case of particles with rod-like, elongated shape. We focus our analysis on the new phenomenology potentially emerging from the coupling—which is inoperative for a spherical shape—of the elongated particle to the strain rate tensor of the chemi-osmotic flow. Via detailed numerical calculations, we show that the dynamics of a rod-like particle exhibits a novel ‘edge-following’ steady state: the particle translates along the edge of a chemical step at a steady distance from the step and with a steady orientation. Moreover, within a certain range of system parameters, the edge-following state co-exists with a ‘docking’ state (the particle stops at the step, oriented perpendicular to the step edge), i.e., a bistable dynamics occurs. These findings are rationalized as a consequence of the competition between the fluid vorticity and the rate of strain by using analytical theory based on the point-particle approximation which captures quasi-quantitatively the dynamics of the system.

  17. Multi-timescale Modeling of Activity-Dependent Metabolic Coupling in the Neuron-Glia-Vasculature Ensemble

    KAUST Repository

    Jolivet, Renaud

    2015-02-26

    Glucose is the main energy substrate in the adult brain under normal conditions. Accumulating evidence, however, indicates that lactate produced in astrocytes (a type of glial cell) can also fuel neuronal activity. The quantitative aspects of this so-called astrocyte-neuron lactate shuttle (ANLS) are still debated. To address this question, we developed a detailed biophysical model of the brain’s metabolic interactions. Our model integrates three modeling approaches, the Buxton-Wang model of vascular dynamics, the Hodgkin-Huxley formulation of neuronal membrane excitability and a biophysical model of metabolic pathways. This approach provides a template for large-scale simulations of the neuron-glia-vasculature (NGV) ensemble, and for the first time integrates the respective timescales at which energy metabolism and neuronal excitability occur. The model is constrained by relative neuronal and astrocytic oxygen and glucose utilization, by the concentration of metabolites at rest and by the temporal dynamics of NADH upon activation. These constraints produced four observations. First, a transfer of lactate from astrocytes to neurons emerged in response to activity. Second, constrained by activity-dependent NADH transients, neuronal oxidative metabolism increased first upon activation with a subsequent delayed astrocytic glycolysis increase. Third, the model correctly predicted the dynamics of extracellular lactate and oxygen as observed in vivo in rats. Fourth, the model correctly predicted the temporal dynamics of tissue lactate, of tissue glucose and oxygen consumption, and of the BOLD signal as reported in human studies. These findings not only support the ANLS hypothesis but also provide a quantitative mathematical description of the metabolic activation in neurons and glial cells, as well as of the macroscopic measurements obtained during brain imaging.

  18. Multi-timescale Modeling of Activity-Dependent Metabolic Coupling in the Neuron-Glia-Vasculature Ensemble

    Science.gov (United States)

    Jolivet, Renaud; Coggan, Jay S.; Allaman, Igor; Magistretti, Pierre J.

    2015-01-01

    Glucose is the main energy substrate in the adult brain under normal conditions. Accumulating evidence, however, indicates that lactate produced in astrocytes (a type of glial cell) can also fuel neuronal activity. The quantitative aspects of this so-called astrocyte-neuron lactate shuttle (ANLS) are still debated. To address this question, we developed a detailed biophysical model of the brain’s metabolic interactions. Our model integrates three modeling approaches, the Buxton-Wang model of vascular dynamics, the Hodgkin-Huxley formulation of neuronal membrane excitability and a biophysical model of metabolic pathways. This approach provides a template for large-scale simulations of the neuron-glia-vasculature (NGV) ensemble, and for the first time integrates the respective timescales at which energy metabolism and neuronal excitability occur. The model is constrained by relative neuronal and astrocytic oxygen and glucose utilization, by the concentration of metabolites at rest and by the temporal dynamics of NADH upon activation. These constraints produced four observations. First, a transfer of lactate from astrocytes to neurons emerged in response to activity. Second, constrained by activity-dependent NADH transients, neuronal oxidative metabolism increased first upon activation with a subsequent delayed astrocytic glycolysis increase. Third, the model correctly predicted the dynamics of extracellular lactate and oxygen as observed in vivo in rats. Fourth, the model correctly predicted the temporal dynamics of tissue lactate, of tissue glucose and oxygen consumption, and of the BOLD signal as reported in human studies. These findings not only support the ANLS hypothesis but also provide a quantitative mathematical description of the metabolic activation in neurons and glial cells, as well as of the macroscopic measurements obtained during brain imaging. PMID:25719367

  19. Multi-timescale modeling of activity-dependent metabolic coupling in the neuron-glia-vasculature ensemble.

    Directory of Open Access Journals (Sweden)

    Renaud Jolivet

    2015-02-01

    Full Text Available Glucose is the main energy substrate in the adult brain under normal conditions. Accumulating evidence, however, indicates that lactate produced in astrocytes (a type of glial cell can also fuel neuronal activity. The quantitative aspects of this so-called astrocyte-neuron lactate shuttle (ANLS are still debated. To address this question, we developed a detailed biophysical model of the brain's metabolic interactions. Our model integrates three modeling approaches, the Buxton-Wang model of vascular dynamics, the Hodgkin-Huxley formulation of neuronal membrane excitability and a biophysical model of metabolic pathways. This approach provides a template for large-scale simulations of the neuron-glia-vasculature (NGV ensemble, and for the first time integrates the respective timescales at which energy metabolism and neuronal excitability occur. The model is constrained by relative neuronal and astrocytic oxygen and glucose utilization, by the concentration of metabolites at rest and by the temporal dynamics of NADH upon activation. These constraints produced four observations. First, a transfer of lactate from astrocytes to neurons emerged in response to activity. Second, constrained by activity-dependent NADH transients, neuronal oxidative metabolism increased first upon activation with a subsequent delayed astrocytic glycolysis increase. Third, the model correctly predicted the dynamics of extracellular lactate and oxygen as observed in vivo in rats. Fourth, the model correctly predicted the temporal dynamics of tissue lactate, of tissue glucose and oxygen consumption, and of the BOLD signal as reported in human studies. These findings not only support the ANLS hypothesis but also provide a quantitative mathematical description of the metabolic activation in neurons and glial cells, as well as of the macroscopic measurements obtained during brain imaging.

  20. The influence of R and S configurations of a series of amphetamine derivatives on quantitative structure–activity relationship models

    International Nuclear Information System (INIS)

    Fresqui, Maíra A.C.; Ferreira, Márcia M.C.; Trsic, Milan

    2013-01-01

    Highlights: ► The QSAR model is not dependent of ligand conformation. ► Amphetamines were analyzed by quantum chemical, steric and hydrophobic descriptors. ► CHELPG atomic charges on the benzene ring are one of the most important descriptors. ► The PLS models built were extensively validated. ► Manual docking supports the QSAR results by pi–pi stacking interactions. - Abstract: Chiral molecules need special attention in drug design. In this sense, the R and S configurations of a series of thirty-four amphetamines were evaluated by quantitative structure–activity relationship (QSAR). This class of compounds has antidepressant, anti-Parkinson and anti-Alzheimer effects against the enzyme monoamine oxidase A (MAO A). A set of thirty-eight descriptors, including electronic, steric and hydrophobic ones, were calculated. Variable selection was performed through the correlation coefficients followed by the ordered predictor selection (OPS) algorithm. Six descriptors (CHELPG atomic charges C3, C4 and C5, electrophilicity, molecular surface area and log P) were selected for both configurations and a satisfactory model was obtained by PLS regression with three latent variables with R 2 = 0.73 and Q 2 = 0.60, with external predictability Q 2 = 0.68, and R 2 = 0.76 and Q 2 = 0.67 with external predictability Q 2 = 0.50, for R and S configurations, respectively. To confirm the robustness of each model, leave-N-out cross validation (LNO) was carried out and the y-randomization test was used to check if these models present chance correlation. Moreover, both automated or a manual molecular docking indicate that the reaction of ligands with the enzyme occurs via pi–pi stacking interaction with Tyr407, inclined face-to-face interaction with Tyr444, while aromatic hydrogen–hydrogen interactions with Tyr197 are preferable for R instead of S configurations.

  1. Recovery of rhythmic activity in a central pattern generator: analysis of the role of neuromodulator and activity-dependent mechanisms.

    Science.gov (United States)

    Zhang, Yili; Golowasch, Jorge

    2011-11-01

    The pyloric network of decapods crustaceans can undergo dramatic rhythmic activity changes. Under normal conditions the network generates low frequency rhythmic activity that depends obligatorily on the presence of neuromodulatory input from the central nervous system. When this input is removed (decentralization) the rhythmic activity ceases. In the continued absence of this input, periodic activity resumes after a few hours in the form of episodic bursting across the entire network that later turns into stable rhythmic activity that is nearly indistinguishable from control (recovery). It has been proposed that an activity-dependent modification of ionic conductance levels in the pyloric pacemaker neuron drives the process of recovery of activity. Previous modeling attempts have captured some aspects of the temporal changes observed experimentally, but key features could not be reproduced. Here we examined a model in which slow activity-dependent regulation of ionic conductances and slower neuromodulator-dependent regulation of intracellular Ca(2+) concentration reproduce all the temporal features of this recovery. Key aspects of these two regulatory mechanisms are their independence and their different kinetics. We also examined the role of variability (noise) in the activity-dependent regulation pathway and observe that it can help to reduce unrealistic constraints that were otherwise required on the neuromodulator-dependent pathway. We conclude that small variations in intracellular Ca(2+) concentration, a Ca(2+) uptake regulation mechanism that is directly targeted by neuromodulator-activated signaling pathways, and variability in the Ca(2+) concentration sensing signaling pathway can account for the observed changes in neuronal activity. Our conclusions are all amenable to experimental analysis.

  2. Quantitative high-throughput screening identifies 8-hydroxyquinolines as cell-active histone demethylase inhibitors.

    Directory of Open Access Journals (Sweden)

    Oliver N F King

    2010-11-01

    Full Text Available Small molecule modulators of epigenetic processes are currently sought as basic probes for biochemical mechanisms, and as starting points for development of therapeutic agents. N(ε-Methylation of lysine residues on histone tails is one of a number of post-translational modifications that together enable transcriptional regulation. Histone lysine demethylases antagonize the action of histone methyltransferases in a site- and methylation state-specific manner. N(ε-Methyllysine demethylases that use 2-oxoglutarate as co-factor are associated with diverse human diseases, including cancer, inflammation and X-linked mental retardation; they are proposed as targets for the therapeutic modulation of transcription. There are few reports on the identification of templates that are amenable to development as potent inhibitors in vivo and large diverse collections have yet to be exploited for the discovery of demethylase inhibitors.High-throughput screening of a ∼236,000-member collection of diverse molecules arrayed as dilution series was used to identify inhibitors of the JMJD2 (KDM4 family of 2-oxoglutarate-dependent histone demethylases. Initial screening hits were prioritized by a combination of cheminformatics, counterscreening using a coupled assay enzyme, and orthogonal confirmatory detection of inhibition by mass spectrometric assays. Follow-up studies were carried out on one of the series identified, 8-hydroxyquinolines, which were shown by crystallographic analyses to inhibit by binding to the active site Fe(II and to modulate demethylation at the H3K9 locus in a cell-based assay.These studies demonstrate that diverse compound screening can yield novel inhibitors of 2OG dependent histone demethylases and provide starting points for the development of potent and selective agents to interrogate epigenetic regulation.

  3. Association between quantitative measures obtained using fluorescence-based methods and activity status of occlusal caries lesions in primary molars.

    Science.gov (United States)

    Novaes, Tatiane Fernandes; Reyes, Alessandra; Matos, Ronilza; Antunes-Pontes, Laura Regina; Marques, Renata Pereira de Samuel; Braga, Mariana Minatel; Diniz, Michele Baffi; Mendes, Fausto Medeiros

    2017-05-01

    Fluorescence-based methods (FBM) can add objectiveness to diagnosis strategy for caries. Few studies, however, have focused on the evaluation of caries activity. To evaluate the association between quantitative measures obtained with FBM, clinical parameters acquired from the patients, caries detection, and assessment of activity status in occlusal surfaces of primary molars. Six hundred and six teeth from 113 children (4-14 years) were evaluated. The presence of a biofilm, caries experience, and the number of active lesions were recorded. The teeth were assessed using FBM: DIAGNOdent pen (Lfpen) and Quantitative light-induced fluorescence (QLF). As reference standard, all teeth were evaluated using the ICDAS (International Caries Detection and Assessment System) associated with clinical activity assessments. Multilevel regressions compared the FBM values and evaluated the association between the FBM measures and clinical variables related to the caries activity. The measures from the FBM were higher in cavitated lesions. Only, ∆F values distinguished active and inactive lesions. The LFpen measures were higher in active lesions, at the cavitated threshold (56.95 ± 29.60). Following regression analyses, only the presence of visible biofilm on occlusal surfaces (adjusted prevalence ratio = 1.43) and ∆R values of the teeth (adjusted prevalence ratio = 1.02) were associated with caries activity. Some quantitative measures from FBM parameters are associated with caries activity evaluation, which is similar to the clinical evaluation of the presence of visible biofilm. © 2016 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Automatic reference selection for quantitative EEG interpretation: identification of diffuse/localised activity and the active earlobe reference, iterative detection of the distribution of EEG rhythms.

    Science.gov (United States)

    Wang, Bei; Wang, Xingyu; Ikeda, Akio; Nagamine, Takashi; Shibasaki, Hiroshi; Nakamura, Masatoshi

    2014-01-01

    EEG (Electroencephalograph) interpretation is important for the diagnosis of neurological disorders. The proper adjustment of the montage can highlight the EEG rhythm of interest and avoid false interpretation. The aim of this study was to develop an automatic reference selection method to identify a suitable reference. The results may contribute to the accurate inspection of the distribution of EEG rhythms for quantitative EEG interpretation. The method includes two pre-judgements and one iterative detection module. The diffuse case is initially identified by pre-judgement 1 when intermittent rhythmic waveforms occur over large areas along the scalp. The earlobe reference or averaged reference is adopted for the diffuse case due to the effect of the earlobe reference depending on pre-judgement 2. An iterative detection algorithm is developed for the localised case when the signal is distributed in a small area of the brain. The suitable averaged reference is finally determined based on the detected focal and distributed electrodes. The presented technique was applied to the pathological EEG recordings of nine patients. One example of the diffuse case is introduced by illustrating the results of the pre-judgements. The diffusely intermittent rhythmic slow wave is identified. The effect of active earlobe reference is analysed. Two examples of the localised case are presented, indicating the results of the iterative detection module. The focal and distributed electrodes are detected automatically during the repeating algorithm. The identification of diffuse and localised activity was satisfactory compared with the visual inspection. The EEG rhythm of interest can be highlighted using a suitable selected reference. The implementation of an automatic reference selection method is helpful to detect the distribution of an EEG rhythm, which can improve the accuracy of EEG interpretation during both visual inspection and automatic interpretation. Copyright © 2013 IPEM

  5. Definition of regional dependence of activity antioxidative enzymes means of the dispersive analysis

    Directory of Open Access Journals (Sweden)

    Anatoly T. Bykov

    2011-05-01

    Full Text Available In article application of the dispersive analysis for an estimation of dependence of activity antioxidative enzymes from region of constant residing, age, sex and the disease diagnosis is considered.

  6. "Exercise Dependence"--A Problem or Natural Result of High Activity?

    Science.gov (United States)

    Phelan, Suzanne; Bond, Dale S.; Lang, Wei; Jordan, Dustin; Wing, Rena R.

    2011-01-01

    Objectives: To compare physical activity (PA) and exercise dependence (ED) in 267 weight-loss maintainers (WLM) and 213 normal-weight (NW) controls. Methods: PA and ED assessed via accelerometery and the Exercise Dependence Questionnaire. Results: WLM had higher PA levels and ED scores than those of NW (P less than 0.0001). WLM status (P = 0.006)…

  7. An Activity Promoting the Practice of Quantitative Literacy for Pre– and In–Service Teachers of Mathematics and Science

    OpenAIRE

    Timothy L. Sorey; Teri Willard; Duane Sholz

    2010-01-01

    The purpose of this article is to describe a hands-on, laboratory activity that provided pre-service teachers in mathematics and science methods courses, and also some in-service mathematics teachers, with the opportunity to exercise quantitative literacy (QL) skills. The focus of the activity is electrical resistance, more particularly the resistance (in ohms) that is painted on small resistors by the use of color-coded bands, one of which is a band for % error. The activity consists of four...

  8. Quantitative Collection and Enzymatic Activity of Glucose Oxidase Nanotubes Fabricated by Templated Layer-by-Layer Assembly.

    Science.gov (United States)

    Zhang, Shouwei; Demoustier-Champagne, Sophie; Jonas, Alain M

    2015-08-10

    We report on the fabrication of enzyme nanotubes in nanoporous polycarbonate membranes via the layer-by-layer (LbL) alternate assembly of polyethylenimine (PEI) and glucose oxidase (GOX), followed by dissolution of the sacrificial template in CH2Cl2, collection, and final dispersion in water. An adjuvant-assisted filtration methodology is exploited to extract quantitatively the nanotubes without loss of activity and morphology. Different water-soluble CH2Cl2-insoluble adjuvants are tested for maximal enzyme activity and nanotube stability; whereas NaCl disrupts the tubes by screening electrostatic interactions, the high osmotic pressure created by fructose also contributes to loosening the nanotubular structures. These issues are solved when using neutral, high molar mass dextran. The enzymatic activity of intact free nanotubes in water is then quantitatively compared to membrane-embedded nanotubes, showing that the liberated nanotubes have a higher catalytic activity in proportion to their larger exposed surface. Our study thus discloses a robust and general methodology for the fabrication and quantitative collection of enzymatic nanotubes and shows that LbL assembly provides access to efficient enzyme carriers for use as catalytic swarming agents.

  9. Preliminary Phytochemical Screening, Quantitative Analysis of Alkaloids, and Antioxidant Activity of Crude Plant Extracts from Ephedra intermedia Indigenous to Balochistan.

    Science.gov (United States)

    Gul, Rahman; Jan, Syed Umer; Faridullah, Syed; Sherani, Samiullah; Jahan, Nusrat

    2017-01-01

    The aim of this study was to evaluate the antioxidant activity, screening the phytogenic chemical compounds, and to assess the alkaloids present in the E. intermedia to prove its uses in Pakistani folk medicines for the treatment of asthma and bronchitis. Antioxidant activity was analyzed by using 2,2-diphenyl-1-picryl-hydrazyl-hydrate assay. Standard methods were used for the identification of cardiac glycosides, phenolic compounds, flavonoids, anthraquinones, and alkaloids. High performance liquid chromatography (HPLC) was used for quantitative purpose of ephedrine alkaloids in E. intermedia . The quantitative separation was confirmed on Shimadzu 10AVP column (Shampack) of internal diameter (id) 3.0 mm and 50 mm in length. The extract of the solute in flow rate of 1 ml/min at the wavelength 210 nm and methanolic extract showed the antioxidant activity and powerful oxygen free radicals scavenging activities and the IC50 for the E. intermedia plant was near to the reference standard ascorbic acid. The HPLC method was useful for the quantitative purpose of ephedrine (E) and pseudoephedrine (PE) used for 45 samples of one species collected from central habitat in three districts (Ziarat, Shairani, and Kalat) of Balochistan. Results showed that average alkaloid substance in E. intermedia was as follows: PE (0.209%, 0.238%, and 0.22%) and E (0.0538%, 0.0666%, and 0.0514%).

  10. Physical activity moderates the association between nicotine dependence and depression among U.S. smokers.

    Science.gov (United States)

    Loprinzi, Paul D; Walker, Jerome F; Kane, Christy; Cardinal, Bradley J

    2014-01-01

    Research demonstrates that nicotine dependence and depression are associated and that physical activity is effective in reducing depression symptoms. However, our understanding of the potential beneficial effects of physical activity on depression in current smokers is more limited. The purpose of this study was to examine whether physical activity moderates the association between nicotine dependence and depression in U.S. smokers. Cross-sectional. National Health and Nutrition Examination Survey 2005-2006. Four hundred forty-one current adult smokers. Participants wore an accelerometer for at least 4 days and completed questionnaires to assess nicotine dependence and depression. Effect modification and statistical interaction models were used. Both models were significant. With regard to the statistical interaction model, and after controlling for age, gender, race/ethnicity, education, comorbidity index, homocysteine, cotinine, total cholesterol, sedentary behavior, and vitamins C, D, and E, objectively measured physical activity moderated the association between nicotine dependence and depression (interaction variable: odds ratio = 3.43; 95% confidence interval: 1.02-11.51; p = .04). In this national sample of current smokers, physical activity moderated the association between nicotine dependence and depression. These results suggest that those individuals with nicotine dependence and who are less physically active are more likely to be depressed than what would be expected on the basis of the individual effects of nicotine and physical inactivity separately.

  11. Myoelectric activity of the small intestine during morphine dependence and withdrawal in rats

    International Nuclear Information System (INIS)

    Kuperman, D.A.; Sninsky, C.A.; Lynch, D.F.

    1987-01-01

    The authors investigated (1) the effect of morphine dependence on the migrating myoelectric complex (MMC) of the small intestine, (2) whether bacterial overgrowth developed in morphine-dependent rats, and (3) the effect of naloxone and methylbromide naltrexone, a peripheral opioid antagonist, on the MMC in morphine-naive and morphine-dependent rats. They also evaluated intestinal motility during naloxone-induced withdrawal in animals pretreated with clonidine. Intestinal myoelectric activity was monitored by four indwelling electrodes in unanesthetized, fasted rats. D-[ 14 C]xylose breath tests were performed before and after morphine-pellet implantation to evaluate the presence of bacterial overgrowth of the small intestine. Naloxone had no effect on myoelectric activity of the small intestine in morphine-naive rats. Cycling activity fronts were present in morphine-dependent animals, but there was a significant prolongation of activity front periodicity and slowing of the propagation velocity. No significant increase in 14 CO 2 excretion was noted in the morphine-dependent rats. They conclude from their studies that (1) myoelectric activity of the small intestine develops incomplete tolerance to morphine; (2) bacterial overgrowth is not a feature of morphine dependence in the rat; (3) alterations of intestinal myoelectric activity are a component of the opiate withdrawal syndrome, and they appear at least partially mediated by a peripheral mechanism that can be suppressed by an α 2 -adrenergic agonist

  12. Myoelectric activity of the small intestine during morphine dependence and withdrawal in rats

    Energy Technology Data Exchange (ETDEWEB)

    Kuperman, D.A.; Sninsky, C.A.; Lynch, D.F.

    1987-04-01

    The authors investigated (1) the effect of morphine dependence on the migrating myoelectric complex (MMC) of the small intestine, (2) whether bacterial overgrowth developed in morphine-dependent rats, and (3) the effect of naloxone and methylbromide naltrexone, a peripheral opioid antagonist, on the MMC in morphine-naive and morphine-dependent rats. They also evaluated intestinal motility during naloxone-induced withdrawal in animals pretreated with clonidine. Intestinal myoelectric activity was monitored by four indwelling electrodes in unanesthetized, fasted rats. D-(/sup 14/C)xylose breath tests were performed before and after morphine-pellet implantation to evaluate the presence of bacterial overgrowth of the small intestine. Naloxone had no effect on myoelectric activity of the small intestine in morphine-naive rats. Cycling activity fronts were present in morphine-dependent animals, but there was a significant prolongation of activity front periodicity and slowing of the propagation velocity. No significant increase in /sup 14/CO/sub 2/ excretion was noted in the morphine-dependent rats. They conclude from their studies that (1) myoelectric activity of the small intestine develops incomplete tolerance to morphine; (2) bacterial overgrowth is not a feature of morphine dependence in the rat; (3) alterations of intestinal myoelectric activity are a component of the opiate withdrawal syndrome, and they appear at least partially mediated by a peripheral mechanism that can be suppressed by an ..cap alpha../sub 2/-adrenergic agonist.

  13. The Role of Hemispheral Asymmetry and Regional Activity of Quantitative EEG in Children with Stuttering

    Science.gov (United States)

    Ozge, Aynur; Toros, Fevziye; Comelekoglu, Ulku

    2004-01-01

    We investigated the role of delayed cerebral maturation, hemisphere asymmetry and regional differences in children with stuttering and healthy controls during resting state and hyperventilation, using conventional EEG techniques and quantitative EEG (QEEG) analysis. This cross-sectional case control study included 26 children with stuttering and…

  14. Levels of plasminogen activator inhibitor type 1 and urokinase plasminogen activator receptor in non-small cell lung cancer as measured by quantitative ELISA and semiquantitative immunohistochemistry

    DEFF Research Database (Denmark)

    Pappot, Helle; Skov, Birgit Guldhammer; Pyke, Charles

    1997-01-01

    The components of the plasminogen activation system have been reported to have prognostic impact in several cancer types, e.g. breast-, colon-, gastric- and lung cancer. Most of these studies have used quantification by enzyme-linked immunosorbent assay (ELISA) on tumour tissue extracts. However......, results in non-small cell lung cancer (NSCLC) studies obtained by quantitative ELISA and semiquantitative immunohistochemistry differ. If the prognostic value of the components of the plasminogen activation system is to be exploited clinically in the future, it is important to choose an easy and valid...... methodology. In the present study we investigated levels of plasminogen activator inhibitor type 1 (PAI-I) and urokinase plasminogen activator receptor (uPAR), as quantitated by ELISA in tumour extracts from 64 NSCLC patients (38 squamous cell carcinomas, 26 adenocarcinomas), and compared them to staining...

  15. Quantitative transmission electron microscopy and atom probe tomography study of Ag-dependent precipitation of Ω phase in Al-Cu-Mg alloys

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Song; Ying, Puyou [Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083 (China); School of Material Science and Engineering, Central South University, Changsha 410083 (China); Liu, Zhiyi, E-mail: liuzhiyi@csu.edu.cn [Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083 (China); School of Material Science and Engineering, Central South University, Changsha 410083 (China); Wang, Jian; Li, Junlin [Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083 (China); School of Material Science and Engineering, Central South University, Changsha 410083 (China)

    2017-02-27

    The close association between the Ω precipitation and various Ag additions is systematically investigated by quantitative transmission electron microscopy and atom probe tomography analysis. Our results suggest that the precipitation of Ω phase is strongly dependent on Ag variations. Increasing the bulk Ag content favors a denser Ω precipitation and hence leads to a greater age-hardening response of Al-Cu-Mg-Ag alloy. This phenomenon, as proposed by proximity histograms, is directly related to the greater abundance of Ag solutes within Ω precursors. This feature lowers its nucleation barrier and increases the nucleation rate of Ω phase, finally contributes to the enhanced Ω precipitation. Also, it is noted that increasing Ag remarkably restricts the precipitation of θ' phase.

  16. Device-dependent activity estimation and decay correction of radionuclide mixtures with application to Tc-94m PET studies

    International Nuclear Information System (INIS)

    Smith, Mark F.; Daube-Witherspoon, Margaret E.; Plascjak, Paul S.; Szajek, Lawrence P.; Carson, Richard E.; Everett, James R.; Green, Shielah L.; Territo, Paul R.; Balaban, Robert S.; Bacharach, Stephen L.; Eckelman, William C.

    2001-01-01

    Multi-instrument activity estimation and decay correction techniques were developed for radionuclide mixtures, motivated by the desire for accurate quantitation of Tc-94m positron emission tomography (PET) studies. Tc-94m and byproduct Tc isotopes were produced by proton irradiation of enriched Mo-94 and natural Mo targets. Mixture activities at the end of bombardment were determined with a calibrated high purity germanium detector. The activity fractions of the greatest mixture impurities relative to 100% for Tc-94m averaged 10.0% (Tc-94g) and 3.3% (Tc-93) for enriched targets and 10.1% (Tc-94g), 11.0% (Tc-95), 255.8% (Tc-96m), and 7.2% (Tc-99m) for natural targets. These radioisotopes have different half-lives (e.g., 52.5 min for Tc-94m, 293 min for Tc-94g), positron branching ratios (e.g., 0.72 for Tc-94m, 0.11 for Tc-94g) and gamma ray emissions for themselves and their short-lived, excited Mo daughters. This complicates estimation of injected activity with a dose calibrator, in vivo activity with PET and blood sample activity with a gamma counter. Decay correction using only the Tc-94m half-life overestimates activity and is inadequate. For this reason analytic formulas for activity estimation and decay correction of radionuclide mixtures were developed. Isotope-dependent sensitivity factors for a PET scanner, dose calibrator, and gamma counter were determined using theoretical sensitivity models and fits of experimental decay curves to sums of exponentials with fixed decay rates. For up to 8 h after the end of bombardment with activity from enriched and natural Mo targets, decay-corrected activities were within 3% of the mean for three PET studies of a uniform cylinder, within 3% of the mean for six dose calibrator decay studies, and within 6% of the mean for four gamma counter decay studies. Activity estimation and decay correction for Tc-94m mixtures enable routine use of Tc-94m in quantitative PET, as illustrated by application to a canine Tc-94m sestamibi

  17. Does the benefit on survival from leisure time physical activity depend on physical activity at work?

    DEFF Research Database (Denmark)

    Holtermann, Andreas; Marott, Jacob Louis; Gyntelberg, Finn

    2013-01-01

    To investigate if persons with high physical activity at work have the same benefits from leisure time physical activity as persons with sedentary work.......To investigate if persons with high physical activity at work have the same benefits from leisure time physical activity as persons with sedentary work....

  18. Quantitative research.

    Science.gov (United States)

    Watson, Roger

    2015-04-01

    This article describes the basic tenets of quantitative research. The concepts of dependent and independent variables are addressed and the concept of measurement and its associated issues, such as error, reliability and validity, are explored. Experiments and surveys – the principal research designs in quantitative research – are described and key features explained. The importance of the double-blind randomised controlled trial is emphasised, alongside the importance of longitudinal surveys, as opposed to cross-sectional surveys. Essential features of data storage are covered, with an emphasis on safe, anonymous storage. Finally, the article explores the analysis of quantitative data, considering what may be analysed and the main uses of statistics in analysis.

  19. Neuromodulation of activity-dependent synaptic enhancement at crayfish neuromuscular junction.

    Science.gov (United States)

    Qian, S M; Delaney, K R

    1997-10-17

    decay of ADSE by 5-HT was not accompanied by significant changes in the initial amplitude of activity-dependent components of enhancement 1.5 s after the train. Measurements of presynaptic [Ca2+] indicated that the time course of Ca2+ removal from the presynaptic terminals after trains was not altered by 5-HT. Changes in presynaptic action potential shape, resting membrane potential or postsynaptic impedance after trains cannot account for slower recovery of ADSE. Axonal injection of EDTA slows the removal of residual Ca2+ and the decay of synaptic augmentation after trains of action potentials (K.R. Delaney, D.W. Tank, A quantitative measure of the dependence of short-term synaptic enhancement on presynaptic residual calcium, J. Neurosci. 14 (1994) 5885-5902), but has little or no effect on the 5-HT-induced persistence of ADSE. This also suggests that the time course of ADSE in the presence of 5-HT is not determined primarily by residual Ca2+ removal kinetics. The slowing of ADSE recovery after trains by 5-HT reverses with washing in 5-HT-free saline along with the 5-HT-mediated enhancement of release.

  20. Arbitrage Activities between Offshore and Domestic Yen Money Markets since the End of the Quantitative Easing Policy

    OpenAIRE

    Teppei Nagano; Eiko Ooka; Naohiko Baba

    2007-01-01

    Transactions in the yen money markets have become active since the end of the quantitative easing policy (QEP) in March 2006. In particular, transactions by foreign financial institutions have been increasing in the offshore markets including the FX swap and euroyen deposit markets, as well as the domestic money markets. This Review surveys the spreads and hence the arbitrage relationship between those offshore markets and the domestic money markets. In the short-term money markets, the sprea...

  1. Quantitative activation patterns of cerebral blood flow during mental stimulation after intravenous injection of sup(195m)Au

    International Nuclear Information System (INIS)

    Lindner, P.; Nickel, O.

    1983-01-01

    A previously reported theory for quantitative cerebral blood flow measurement for nondiffusible radiotracers has been applied to patients after stroke and to volunteers undergoing a mental stimulation exercise. Quantitative measurements of cerebral blood flow pattern in p-a and lateral projections of the brain are obtained using the short lived (30s) isotope sup(195m)Au from the recently developed generator. The energy spectrum of the eluate from the generator shows two strong photon peaks, one at an energy level of 68 KeV and a second at 262 KeV. The low-energy peak is suitable for perfusion studies of the cerebral hemispheres in lateral projection, being without ''look through'' effect. The high-energy level is good for studies in p-a-projection. Studies last less than 1 min and can be repeated after 3 min. Parametric images for quantitative regional cerebral blood flow can be generated, in which the avascular region following stroke can be detected. Quantitative activation patterns of cerebral blood flow during mental stimulation can be generated. The results show that it is possible to measure cerebral blood-flow patterns not only with freely diffusible indicators like Xenon but also with nondiffusible indicators. (orig.)

  2. Activation autoradiography: imaging and quantitative determination of endogenous and exogenous oxygen in the rat brain

    International Nuclear Information System (INIS)

    Kawashima, K.; Iwata, R.; Kogure, K.; Ohtomo, H.; Orihara, H.; Ido, T.

    1987-01-01

    Endogenous and exogenous oxygen in the rat brain were quantitatively determined using an autoradiographic technique. The oxygen images of frozen and dried rat brain sections were obtained as 18 F images by using the 16 O ( 3 He,p) 18 F reaction for endogenous 16 O images and the 18 O(p,n) 18 F reaction for endogenous and exogenous 18 O images. These autoradiograms demonstrated the different distribution of oxygen between gray and white matter. These images also allowed differentiation of the individual structures of hippocampal formation, owing to the differing water content of the various structures. Local oxygen contents were quantitatively determined from autoradiograms of brain sections and standard sections with known oxygen contents. The estimated values were 75.6 +/- 4.6 wt% in gray matter and 72.2 +/- 4.0 wt% in white matter. The systematic error in the present method was estimated to be 4.9%

  3. DREAM Controls the On/Off Switch of Specific Activity-Dependent Transcription Pathways

    Science.gov (United States)

    Mellström, Britt; Sahún, Ignasi; Ruiz-Nuño, Ana; Murtra, Patricia; Gomez-Villafuertes, Rosa; Savignac, Magali; Oliveros, Juan C.; Gonzalez, Paz; Kastanauskaite, Asta; Knafo, Shira; Zhuo, Min; Higuera-Matas, Alejandro; Errington, Michael L.; Maldonado, Rafael; DeFelipe, Javier; Jefferys, John G. R.; Bliss, Tim V. P.; Dierssen, Mara

    2014-01-01

    Changes in nuclear Ca2+ homeostasis activate specific gene expression programs and are central to the acquisition and storage of information in the brain. DREAM (downstream regulatory element antagonist modulator), also known as calsenilin/KChIP-3 (K+ channel interacting protein 3), is a Ca2+-binding protein that binds DNA and represses transcription in a Ca2+-dependent manner. To study the function of DREAM in the brain, we used transgenic mice expressing a Ca2+-insensitive/CREB-independent dominant active mutant DREAM (daDREAM). Using genome-wide analysis, we show that DREAM regulates the expression of specific activity-dependent transcription factors in the hippocampus, including Npas4, Nr4a1, Mef2c, JunB, and c-Fos. Furthermore, DREAM regulates its own expression, establishing an autoinhibitory feedback loop to terminate activity-dependent transcription. Ablation of DREAM does not modify activity-dependent transcription because of gene compensation by the other KChIP family members. The expression of daDREAM in the forebrain resulted in a complex phenotype characterized by loss of recurrent inhibition and enhanced long-term potentiation (LTP) in the dentate gyrus and impaired learning and memory. Our results indicate that DREAM is a major master switch transcription factor that regulates the on/off status of specific activity-dependent gene expression programs that control synaptic plasticity, learning, and memory. PMID:24366545

  4. Similar expression patterns of bestrophin-4 and cGMP dependent Ca2+-activated chloride channel activity in the vasculature

    DEFF Research Database (Denmark)

    Bouzinova, Elena V.; Larsen, Per; Matchkov, Vladimir

    2008-01-01

    (abstract by Matchkov et. al) that siRNA mediated downregulation of bestrophin-4 is associated with the disappearance of a recently demonstrated2 cGMP-dependent Ca2+-activated Cl- current in vascular smooth muscle cells (SMCs). Here we study the distribution of bestrophin-4-and cGMP dependent Cl- channel...... expressed epitope) Western blot detected a ~65 kDa band in cell lysates from rat mesenteric small arteries and aorta, which was not seen in pulmonary arteries and when preincubated with the immunizing peptide. The distribution of bestrophin-4 mRNA and protein has a pattern similar to the cGMP-dependent Cl......- current in SMCs of different origins. Immunohistochemistry identified bestrophin-4 both in endothelial and SMCs of the vascular tree in the brain, heart, kidney and mesentery, but not in the lungs. We suggest that bestrophin-4 is important for the cGMP dependent, Ca2+ activated Cl- conductance in many...

  5. Activity-Dependent Bidirectional Regulation of GAD Expression in a Homeostatic Fashion Is Mediated by BDNF-Dependent and Independent Pathways

    Science.gov (United States)

    Hanno-Iijima, Yoko; Tanaka, Masami; Iijima, Takatoshi

    2015-01-01

    Homeostatic synaptic plasticity, or synaptic scaling, is a mechanism that tunes neuronal transmission to compensate for prolonged, excessive changes in neuronal activity. Both excitatory and inhibitory neurons undergo homeostatic changes based on synaptic transmission strength, which could effectively contribute to a fine-tuning of circuit activity. However, gene regulation that underlies homeostatic synaptic plasticity in GABAergic (GABA, gamma aminobutyric) neurons is still poorly understood. The present study demonstrated activity-dependent dynamic scaling in which NMDA-R (N-methyl-D-aspartic acid receptor) activity regulated the expression of GABA synthetic enzymes: glutamic acid decarboxylase 65 and 67 (GAD65 and GAD67). Results revealed that activity-regulated BDNF (brain-derived neurotrophic factor) release is necessary, but not sufficient, for activity-dependent up-scaling of these GAD isoforms. Bidirectional forms of activity-dependent GAD expression require both BDNF-dependent and BDNF-independent pathways, both triggered by NMDA-R activity. Additional results indicated that these two GAD genes differ in their responsiveness to chronic changes in neuronal activity, which could be partially caused by differential dependence on BDNF. In parallel to activity-dependent bidirectional scaling in GAD expression, the present study further observed that a chronic change in neuronal activity leads to an alteration in neurotransmitter release from GABAergic neurons in a homeostatic, bidirectional fashion. Therefore, the differential expression of GAD65 and 67 during prolonged changes in neuronal activity may be implicated in some aspects of bidirectional homeostatic plasticity within mature GABAergic presynapses. PMID:26241953

  6. Determination of the spectral dependence of reduced scattering and quantitative second-harmonic generation imaging for detection of fibrillary changes in ovarian cancer

    Science.gov (United States)

    Campbell, Kirby R.; Tilbury, Karissa B.; Campagnola, Paul J.

    2015-03-01

    Here, we examine ovarian cancer extracellular matrix (ECM) modification by measuring the wavelength dependence of optical scattering measurements and quantitative second-harmonic generation (SHG) imaging metrics in the range of 800-1100 nm in order to determine fibrillary changes in ex vivo normal ovary, type I, and type II ovarian cancer. Mass fractals of the collagen fiber structure is analyzed based on a power law correlation function using spectral dependence measurements of the reduced scattering coefficient μs' where the mass fractal dimension is related to the power. Values of μs' are measured using independent methods of determining the values of μs and g by on-axis attenuation measurements using the Beer-Lambert Law and by fitting the angular distribution of scattering to the Henyey-Greenstein phase function, respectively. Quantitativespectral SHG imaging on the same tissues determines FSHG/BSHG creation ratios related to size and harmonophore distributions. Both techniques probe fibril packing order, but the optical scattering probes structures of sizes from about 50-2000 nm where SHG imaging - although only able to resolve individual fibers - builds contrast from the assembly of fibrils. Our findings suggest that type I ovarian tumor structure has the most ordered collagen fibers followed by normal ovary then type II tumors showing the least order.

  7. Nerve growth factor enhances the CRE-dependent transcriptional activity activated by nobiletin in PC12 cells.

    Science.gov (United States)

    Takito, Jiro; Kimura, Junko; Kajima, Koji; Uozumi, Nobuyuki; Watanabe, Makoto; Yokosuka, Akihito; Mimaki, Yoshihiro; Nakamura, Masanori; Ohizumi, Yasushi

    2016-07-01

    Prevention and treatment of Alzheimer disease are urgent problems for elderly people in developed countries. We previously reported that nobiletin, a poly-methoxylated flavone from the citrus peel, improved the symptoms in various types of animal models of memory loss and activated the cAMP responsive element (CRE)-dependent transcription in PC12 cells. Nobiletin activated the cAMP/PKA/MEK/Erk/MAPK signaling pathway without using the TrkA signaling activated by nerve growth factor (NGF). Here, we examined the effect of combination of nobiletin and NGF on the CRE-dependent transcription in PC12 cells. Although NGF alone had little effect on the CRE-dependent transcription, NGF markedly enhanced the CRE-dependent transcription induced by nobiletin. The NGF-induced enhancement was neutralized by a TrkA antagonist, K252a. This effect of NGF was effective on the early signaling event elicited by nobiletin. These results suggested that there was crosstalk between NGF and nobiletin signaling in activating the CRE-dependent transcription in PC12 cells.

  8. The Stress-Dependent Activation Parameters for Dislocation Nucleation in Molybdenum Nanoparticles.

    Science.gov (United States)

    Chachamovitz, Doron; Mordehai, Dan

    2018-03-02

    Many specimens at the nanoscale are pristine of dislocations, line defects which are the main carriers of plasticity. As a result, they exhibit extremely high strengths which are dislocation-nucleation controlled. Since nucleation is a thermally activated process, it is essential to quantify the stress-dependent activation parameters for dislocation nucleation in order to study the strength of specimens at the nanoscale and its distribution. In this work, we calculate the strength of Mo nanoparticles in molecular dynamics simulations and we propose a method to extract the activation free-energy barrier for dislocation nucleation from the distribution of the results. We show that by deforming the nanoparticles at a constant strain rate, their strength distribution can be approximated by a normal distribution, from which the activation volumes at different stresses and temperatures are calculated directly. We found that the activation energy dependency on the stress near spontaneous nucleation conditions obeys a power-law with a critical exponent of approximately 3/2, which is in accordance with critical exponents found in other thermally activated processes but never for dislocation nucleation. Additionally, significant activation entropies were calculated. Finally, we generalize the approach to calculate the activation parameters for other driving-force dependent thermally activated processes.

  9. Quantitative detection and biological propagation of scrapie seeding activity in vitro facilitate use of prions as model pathogens for disinfection.

    Directory of Open Access Journals (Sweden)

    Sandra Pritzkow

    Full Text Available Prions are pathogens with an unusually high tolerance to inactivation and constitute a complex challenge to the re-processing of surgical instruments. On the other hand, however, they provide an informative paradigm which has been exploited successfully for the development of novel broad-range disinfectants simultaneously active also against bacteria, viruses and fungi. Here we report on the development of a methodological platform that further facilitates the use of scrapie prions as model pathogens for disinfection. We used specifically adapted serial protein misfolding cyclic amplification (PMCA for the quantitative detection, on steel wires providing model carriers for decontamination, of 263K scrapie seeding activity converting normal protease-sensitive into abnormal protease-resistant prion protein. Reference steel wires carrying defined amounts of scrapie infectivity were used for assay calibration, while scrapie-contaminated test steel wires were subjected to fifteen different procedures for disinfection that yielded scrapie titre reductions of ≤10(1- to ≥10(5.5-fold. As confirmed by titration in hamsters the residual scrapie infectivity on test wires could be reliably deduced for all examined disinfection procedures, from our quantitative seeding activity assay. Furthermore, we found that scrapie seeding activity present in 263K hamster brain homogenate or multiplied by PMCA of scrapie-contaminated steel wires both triggered accumulation of protease-resistant prion protein and was further propagated in a novel cell assay for 263K scrapie prions, i.e., cerebral glial cell cultures from hamsters. The findings from our PMCA- and glial cell culture assays revealed scrapie seeding activity as a biochemically and biologically replicative principle in vitro, with the former being quantitatively linked to prion infectivity detected on steel wires in vivo. When combined, our in vitro assays provide an alternative to titrations of biological

  10. Spatial-temporal patterns of retinal waves underlying activity-dependent refinement of retinofugal projections.

    Science.gov (United States)

    Stafford, Ben K; Sher, Alexander; Litke, Alan M; Feldheim, David A

    2009-10-29

    During development, retinal axons project coarsely within their visual targets before refining to form organized synaptic connections. Spontaneous retinal activity, in the form of acetylcholine-driven retinal waves, is proposed to be necessary for establishing these projection patterns. In particular, both axonal terminations of retinal ganglion cells (RGCs) and the size of receptive fields of target neurons are larger in mice that lack the beta2 subunit of the nicotinic acetylcholine receptor (beta2KO). Here, using a large-scale, high-density multielectrode array to record activity from hundreds of RGCs simultaneously, we present analysis of early postnatal retinal activity from both wild-type (WT) and beta2KO retinas. We find that beta2KO retinas have correlated patterns of activity, but many aspects of these patterns differ from those of WT retina. Quantitative analysis suggests that wave directionality, coupled with short-range correlated bursting patterns of RGCs, work together to refine retinofugal projections.

  11. The influence of R and S configurations of a series of amphetamine derivatives on quantitative structure-activity relationship models

    Energy Technology Data Exchange (ETDEWEB)

    Fresqui, Maira A.C., E-mail: maira@iqsc.usp.br [Institute of Chemistry of Sao Carlos, University of Sao Paulo, Av. Trabalhador Sao-carlense, 400, POB 780, 13560-970 Sao Carlos, SP (Brazil); Ferreira, Marcia M.C., E-mail: marcia@iqm.unicamp.br [Institute of Chemistry, University of Campinas - UNICAMP, POB 6154, 13083-970 Campinas, SP (Brazil); Trsic, Milan, E-mail: cra612@gmail.com [Institute of Chemistry of Sao Carlos, University of Sao Paulo, Av. Trabalhador Sao-carlense, 400, POB 780, 13560-970 Sao Carlos, SP (Brazil)

    2013-01-08

    Highlights: Black-Right-Pointing-Pointer The QSAR model is not dependent of ligand conformation. Black-Right-Pointing-Pointer Amphetamines were analyzed by quantum chemical, steric and hydrophobic descriptors. Black-Right-Pointing-Pointer CHELPG atomic charges on the benzene ring are one of the most important descriptors. Black-Right-Pointing-Pointer The PLS models built were extensively validated. Black-Right-Pointing-Pointer Manual docking supports the QSAR results by pi-pi stacking interactions. - Abstract: Chiral molecules need special attention in drug design. In this sense, the R and S configurations of a series of thirty-four amphetamines were evaluated by quantitative structure-activity relationship (QSAR). This class of compounds has antidepressant, anti-Parkinson and anti-Alzheimer effects against the enzyme monoamine oxidase A (MAO A). A set of thirty-eight descriptors, including electronic, steric and hydrophobic ones, were calculated. Variable selection was performed through the correlation coefficients followed by the ordered predictor selection (OPS) algorithm. Six descriptors (CHELPG atomic charges C3, C4 and C5, electrophilicity, molecular surface area and log P) were selected for both configurations and a satisfactory model was obtained by PLS regression with three latent variables with R{sup 2} = 0.73 and Q{sup 2} = 0.60, with external predictability Q{sup 2} = 0.68, and R{sup 2} = 0.76 and Q{sup 2} = 0.67 with external predictability Q{sup 2} = 0.50, for R and S configurations, respectively. To confirm the robustness of each model, leave-N-out cross validation (LNO) was carried out and the y-randomization test was used to check if these models present chance correlation. Moreover, both automated or a manual molecular docking indicate that the reaction of ligands with the enzyme occurs via pi-pi stacking interaction with Tyr407, inclined face-to-face interaction with Tyr444, while aromatic hydrogen-hydrogen interactions with Tyr197 are preferable

  12. Monte Carlo simulations towards semi-quantitative prompt gamma activation imaging

    International Nuclear Information System (INIS)

    Kis, Zoltan; Belgya, Tamas; Szentmiklosi, Laszlo

    2011-01-01

    Numerous non-destructive techniques utilize neutron attenuation, scattering or capture to gain morphological, structural or elemental information about the material under study. However, few attempts have been made so far to use neutron-induced gamma radiation for 3D element mapping. The first ever facility using direct scanning for element imaging was set up at the Budapest Research Reactor. It was shown that the position-sensitive prompt-gamma detection (PGAI) enables us to determine the spatial distribution of major elements. Iterative Monte Carlo simulation technique has also been developed to provide not only qualitative but also semi-quantitative element distribution of a simple object.

  13. Quantitative And Qualitative Measurement Of Radio- Activity In Sand Samples From Chalet Beach In Songkhla Province

    International Nuclear Information System (INIS)

    Sukhowattanakit, Jirapa; Kessaratikoon, Prasong; Udomsomporn, Suchin; Thorarit, Wutthidej

    2005-10-01

    The quantitative and qualitative measurement of radioactivity in 39 sand samples collected from Chalatat beach in Songkhla province are presented. Experimental results were obtained by using a high-purity germanium detector and gamma spectroscopy analysis system and comparing to the standard soil (IAEA SOIL 6) at the Office of Atoms for Peace (OAP). The measuring time of all sand samples is 10,000 seconds. Some radioisotopes such as K-40, Cs-137, Tl-208, Bi-212, Pb-212, Bi-214, Pb- 214, Ra-226 and Ac-228 were found in sand samples. In addition, the radioactivity of Ra-226 and Cs-137 in those samples were found in normal level

  14. Strings on a Violin: Location Dependence of Frequency Tuning in Active Dendrites.

    Science.gov (United States)

    Das, Anindita; Rathour, Rahul K; Narayanan, Rishikesh

    2017-01-01

    Strings on a violin are tuned to generate distinct sound frequencies in a manner that is firmly dependent on finger location along the fingerboard. Sound frequencies emerging from different violins could be very different based on their architecture, the nature of strings and their tuning. Analogously, active neuronal dendrites, dendrites endowed with active channel conductances, are tuned to distinct input frequencies in a manner that is dependent on the dendritic location of the synaptic inputs. Further, disparate channel expression profiles and differences in morphological characteristics could result in dendrites on different neurons of the same subtype tuned to distinct frequency ranges. Alternately, similar location-dependence along dendritic structures could be achieved through disparate combinations of channel profiles and morphological characteristics, leading to degeneracy in active dendritic spectral tuning. Akin to strings on a violin being tuned to different frequencies than those on a viola or a cello, different neuronal subtypes exhibit distinct channel profiles and disparate morphological characteristics endowing each neuronal subtype with unique location-dependent frequency selectivity. Finally, similar to the tunability of musical instruments to elicit distinct location-dependent sounds, neuronal frequency selectivity and its location-dependence are tunable through activity-dependent plasticity of ion channels and morphology. In this morceau, we explore the origins of neuronal frequency selectivity, and survey the literature on the mechanisms behind the emergence of location-dependence in distinct forms of frequency tuning. As a coda to this composition, we present some future directions for this exciting convergence of biophysical mechanisms that endow a neuron with frequency multiplexing capabilities.

  15. Frequency dependence of the active impedance component of silicon thin-film resistors

    International Nuclear Information System (INIS)

    Belogurov, S.V.; Gostilo, V.V.; Yurov, A.S.

    1987-01-01

    A high-resistant resistor on the silicon thin-film substrate considerably superior in noise and frequency performance than commercial resistors is described. The frequency dependence of the active impedance component is tested for determining noise and frequency dependences of silicon thin-film resistors. The obtained results permit to calculate the energy equivalent of resistor noise in nuclear radiation detection units at any temperature according to its frequency characteristic at room temperature

  16. Intense Activity of the Raphe Spinal Pathway Depresses Motor Activity via a Serotonin Dependent Mechanism

    DEFF Research Database (Denmark)

    Perrier, Jean-François; Rasmussen, Hanne B; Jørgensen, Lone K

    2018-01-01

    Motor fatigue occurring during prolonged physical activity has both peripheral and central origins. It was previously demonstrated that the excitability of motoneurons was decreased when a spillover of serotonin could activate extrasynaptic 5-HT1A receptors at the axon initial segment (AIS...

  17. Going the distance: Memory and control processes in active dependency construction.

    Science.gov (United States)

    Wagers, Matthew W; Phillips, Colin

    2014-01-01

    Filler-gap dependencies make strong demands on working memory in language comprehension because they cannot always be immediately resolved. In a series of three reading-time studies, we test the idea that these demands can be decomposed into active maintenance processes and retrieval events. Results indicate that the fact that a displaced phrase exists and the identity of its basic syntactic category both immediately impact comprehension at potential gap sites. In contrast, specific lexical details of the displaced phrase show an immediate effect only for short dependencies and a much later effect for longer dependencies. We argue that coarse-grained information about the filler is actively maintained and is used to make phrase structure parsing decisions, whereas finer grained information is more quickly released from active maintenance and consequently has to be retrieved at the gap site.

  18. Striatal activation and frontostriatal connectivity during non-drug reward anticipation in alcohol dependence.

    Science.gov (United States)

    Becker, Alena; Kirsch, Martina; Gerchen, Martin Fungisai; Kiefer, Falk; Kirsch, Peter

    2017-05-01

    According to prevailing neurobiological theories of addiction, altered function in neural reward circuitry is a central mechanism of alcohol dependence. Growing evidence postulates that the ventral striatum (VS), as well as areas of the prefrontal cortex, contribute to the increased incentive salience of alcohol-associated cues, diminished motivation to pursue non-drug rewards and weakened strength of inhibitory cognitive control, which are central to addiction. The present study aims to investigate the neural response and functional connectivity underlying monetary, non-drug reward processing in alcohol dependence. We utilized a reward paradigm to investigate the anticipation of monetary reward in 32 alcohol-dependent inpatients and 35 healthy controls. Functional magnetic resonance imaging was used to measure task-related brain activation and connectivity. Alcohol-dependent patients showed increased activation of the VS during anticipation of monetary gain compared with healthy controls. Generalized psychophysiological interaction analyses revealed decreased functional connectivity between the VS and the dorsolateral prefrontal cortex in alcohol dependent patients relative to controls. Increased activation of the VS and reduced frontostriatal connectivity were associated with increased craving. These findings provide evidence that alcohol dependence is rather associated with disrupted integration of striatal and prefrontal processes than with a global reward anticipation deficit. © 2016 Society for the Study of Addiction.

  19. Glucocorticoids activate the ATP-ubiquitin-dependent proteolytic system in skeletal muscle during fasting

    Science.gov (United States)

    Wing, S. S.; Goldberg, A. L.; Goldberger, A. L. (Principal Investigator)

    1993-01-01

    Glucocorticoids are essential for the increase in protein breakdown in skeletal muscle normally seen during fasting. To determine which proteolytic pathway(s) are activated upon fasting, leg muscles from fed and fasted normal rats were incubated under conditions that block or activate different proteolytic systems. After food deprivation (1 day), the nonlysosomal ATP-dependent process increased by 250%, as shown in experiments involving depletion of muscle ATP. Also, the maximal capacity of the lysosomal process increased 60-100%, but no changes occurred in the Ca(2+)-dependent or the residual energy-independent proteolytic processes. In muscles from fasted normal and adrenalectomized (ADX) rats, the protein breakdown sensitive to inhibitors of the lysosomal or Ca(2+)-dependent pathways did not differ. However, the ATP-dependent process was 30% slower in muscles from fasted ADX rats. Administering dexamethasone to these animals or incubating their muscles with dexamethasone reversed this defect. During fasting, when the ATP-dependent process rises, muscles show a two- to threefold increase in levels of ubiquitin (Ub) mRNA. However, muscles of ADX animals failed to show this response. Injecting dexamethasone into the fasted ADX animals increased muscle Ub mRNA within 6 h. Thus glucocorticoids activate the ATP-Ub-dependent proteolytic pathway in fasting apparently by enhancing the expression of components of this system such as Ub.

  20. Depigmenting Effect of Resveratrol Is Dependent on FOXO3a Activation without SIRT1 Activation.

    Science.gov (United States)

    Kwon, Soon-Hyo; Choi, Hye-Ryung; Kang, Youn-A; Park, Kyoung-Chan

    2017-06-07

    Resveratrol exhibits not only anti-melanogenic property by inhibiting microphthalmia-associated transcription factor (MITF), but also anti-aging property by activating sirtuin-1 (SIRT1). In this study, the relationship between depigmenting effect of resveratrol and SIRT1/forkhead box O (FOXO) 3a activation and was investigated. Resveratrol suppressed melanogenesis by the downregulation of MITF and tyrosinase via ERK pathway. Results showed that the expression of both SIRT1 and FOXO3a were increased. It is reported that SIRT1 is critical regulator of FOXO-mediated transcription in response to oxidative stress. However in our study, FOXO3a activation appeared earlier than that of SIRT1. Furthermore, the effect of resveratrol on the levels of MITF and tyrosinase was suppressed when melanocytes were pre-treated with SP600125 (JNK inhibitor). However, pre-treatment with SIRT1 inhibitor (EX527, or sirtinol) did not affect the levels of MITF and tyrosinase. Therefore, resveratrol inhibits melanogenesis through the activation of FOXO3a but not by the activation of SIRT1. Although SIRT1 activation by resveratrol is a well-known mechanism of resveratrol-induced antiaging effects, our study showed that not SIRT1 but FOXO3a activation is involved in depigmenting effects of resveratrol.

  1. [Suicidal and personality characteristics of women married to men with alcohol dependence and suicidal activity].

    Science.gov (United States)

    Merinov, A V; Shustov, D I

    2011-01-01

    The effect of the suicidal activity in men with alcohol dependence on suicidal indexes, personal-codependency and psychological specifics of their wives has been studied. It has been found that women married to suicidal men with alcohol dependence significantly more frequently demonstrate suicidal activity (a phenomenon of suicidal matrimonial comorbidity) compared to wives of "non-suicidal" men. They also reveal non-suicidal behavioral patterns more frequently and prosuicidal predictors are quite common in them. This contingent of women has high suicidal potential that needs special attention during the therapeutic work.

  2. Quantitative structure-activation barrier relationship modeling for Diels-Alder ligations utilizing quantum chemical structural descriptors.

    Science.gov (United States)

    Nandi, Sisir; Monesi, Alessandro; Drgan, Viktor; Merzel, Franci; Novič, Marjana

    2013-10-30

    In the present study, we show the correlation of quantum chemical structural descriptors with the activation barriers of the Diels-Alder ligations. A set of 72 non-catalysed Diels-Alder reactions were subjected to quantitative structure-activation barrier relationship (QSABR) under the framework of theoretical quantum chemical descriptors calculated solely from the structures of diene and dienophile reactants. Experimental activation barrier data were obtained from literature. Descriptors were computed using Hartree-Fock theory using 6-31G(d) basis set as implemented in Gaussian 09 software. Variable selection and model development were carried out by stepwise multiple linear regression methodology. Predictive performance of the quantitative structure-activation barrier relationship (QSABR) model was assessed by training and test set concept and by calculating leave-one-out cross-validated Q2 and predictive R2 values. The QSABR model can explain and predict 86.5% and 80% of the variances, respectively, in the activation energy barrier training data. Alternatively, a neural network model based on back propagation of errors was developed to assess the nonlinearity of the sought correlations between theoretical descriptors and experimental reaction barriers. A reasonable predictability for the activation barrier of the test set reactions was obtained, which enabled an exploration and interpretation of the significant variables responsible for Diels-Alder interaction between dienes and dienophiles. Thus, studies in the direction of QSABR modelling that provide efficient and fast prediction of activation barriers of the Diels-Alder reactions turn out to be a meaningful alternative to transition state theory based computation.

  3. Transgenic mice expressing constitutive active MAPKAPK5 display gender-dependent differences in exploration and activity

    Directory of Open Access Journals (Sweden)

    Moens Ugo

    2007-11-01

    Full Text Available Abstract Background The mitogen-activated protein kinases, MAPKs for short, constitute cascades of signalling pathways involved in the regulation of several cellular processes that include cell proliferation, differentiation and motility. They also intervene in neurological processes like fear conditioning and memory. Since little remains known about the MAPK-Activated Protein Kinase, MAPKAPK5, we constructed the first MAPKAPK knockin mouse model, using a constitutive active variant of MAPKAPK5 and analyzed the resulting mice for changes in anxiety-related behaviour. Methods We performed primary SHIRPA observations during background breeding into the C57BL/6 background and assessed the behaviour of the background-bred animals on the elevated plus maze and in the light-dark test. Our results were analyzed using Chi-square tests and homo- and heteroscedatic T-tests. Results Female transgenic mice displayed increased amounts of head dips and open arm time on the maze, compared to littermate controls. In addition, they also explored further into the open arm on the elevated plus maze and were less active in the closed arm compared to littermate controls. Male transgenic mice displayed no differences in anxiety, but their locomotor activity increased compared to non-transgenic littermates. Conclusion Our results revealed anxiety-related traits and locomotor differences between transgenic mice expressing constitutive active MAPKAPK5 and control littermates.

  4. Constitutive NADPH-Dependent Electron Transferase Activity of the Nox4 Dehydrogenase Domain?

    OpenAIRE

    Nisimoto, Yukio; Jackson, Heather M.; Ogawa, Hisamitsu; Kawahara, Tsukasa; Lambeth, J. David

    2010-01-01

    NADPH oxidase 4 (Nox4) is constitutively active, while Nox2 requires the cytosolic regulatory subunits p47 phox and p67 phox and activated Rac with activation by phorbol 12-myristate 13-acetate (PMA). This study was undertaken to identify the domain on Nox4 that confers constitutive activity. Lysates from Nox4-expressing cells exhibited constitutive NADPH- but not NADH-dependent hydrogen peroxide production with a K m for NADPH of 55 ? 10 ?M. The concentration of Nox4 in cell lysates was esti...

  5. Field dependence-independence as related to young women's participation in sports activity.

    Science.gov (United States)

    Lambrecht, Jeanne L; Cuevas, Jacqueline L

    2007-06-01

    To estimate association between field dependence-independence measured by scores on the Group Embedded Figures Test and young women's participation in sports activity. Participants were 37 undergraduate college women between the ages of 18 and 25 years (M=21). Participants were categorized into two groups, one high in participation in sports activity and one low. A one-tailed independent samples t test yielded no significant difference. Correlations of .36 and .18 were significant but account for little common variance. An ad hoc analysis performed without participants who reported softball activity but who were highly involved in sport activities was significant.

  6. Heterogeneity of hydrolytic enzyme activities under drought: imaging and quantitative analysis

    Science.gov (United States)

    Sanaullah, Muhammad; Razavi, Bahar S.; Kuzyakov, Yakov

    2015-04-01

    The zymography-based "snap-shoot" of enzyme activities in the rhizosphere is challenging to detect the in situ microbial response to global climate change. We developed in situ soil zymography and used it for identification and localization of hotspots of β-glucosidase activity in the rhizosphere of maize under drought stress (30% of field capacity). The zymographic signals were especially high at root tips and were much stronger for activity of β-glucosidase under drought as compared with optimal moisture (70% of field capacity). This distribution of enzyme activity was confirmed by fluorogenically labelled substrates applied directly to the root exudates. The activity of β-glucosidase in root exudates (produced by root and microorganism associated on the root surface), sampled within 1 hour after zymography was significantly higher by drought stressed plants as compared with optimal moisture. In contrast, the β-glucosidase activity in destructively sampled rhizosphere soil was lower under drought stress compared with optimal moisture. Furthermore, drought stress did not affected β-glucosidase activity in bulk soil, away from rhizosphere. Consequently, we conclude that higher release of mucilage by roots und drought stimulated β-glucosidase activity in the rhizosphere. Thus, the zymography revealed plant-mediated mechanisms accelerating β-glucosidase activity under drought at the root-soil interface. So, coupling of zymography and enzyme assays in the rhizosphere and non-rhizosphere soil enables precise mapping the changes in two-dimensional distribution of enzyme activities due to climate change within dynamic soil interfaces.

  7. Space-Time Dependent Transport, Activation, and Dose Rates for Radioactivated Fluids.

    Science.gov (United States)

    Gavazza, Sergio

    Two methods are developed to calculate the space - and time-dependent mass transport of radionuclides, their production and decay, and the associated dose rates generated from the radioactivated fluids flowing through pipes. The work couples space- and time-dependent phenomena, treated as only space- or time-dependent in the open literature. The transport and activation methodology (TAM) is used to numerically calculate space- and time-dependent transport and activation of radionuclides in fluids flowing through pipes exposed to radiation fields, and volumetric radioactive sources created by radionuclide motions. The computer program Radionuclide Activation and Transport in Pipe (RNATPA1) performs the numerical calculations required in TAM. The gamma ray dose methodology (GAM) is used to numerically calculate space- and time-dependent gamma ray dose equivalent rates from the volumetric radioactive sources determined by TAM. The computer program Gamma Ray Dose Equivalent Rate (GRDOSER) performs the numerical calculations required in GAM. The scope of conditions considered by TAM and GAM herein include (a) laminar flow in straight pipe, (b)recirculating flow schemes, (c) time-independent fluid velocity distributions, (d) space-dependent monoenergetic neutron flux distribution, (e) space- and time-dependent activation process of a single parent nuclide and transport and decay of a single daughter radionuclide, and (f) assessment of space- and time-dependent gamma ray dose rates, outside the pipe, generated by the space- and time-dependent source term distributions inside of it. The methodologies, however, can be easily extended to include all the situations of interest for solving the phenomena addressed in this dissertation. A comparison is made from results obtained by the described calculational procedures with analytical expressions. The physics of the problems addressed by the new technique and the increased accuracy versus non -space and time-dependent methods

  8. Determination of glutamate dehydrogenase activity and its kinetics in mouse tissues using metabolic mapping (quantitative enzyme histochemistry).

    Science.gov (United States)

    Botman, Dennis; Tigchelaar, Wikky; Van Noorden, Cornelis J F

    2014-11-01

    Glutamate dehydrogenase (GDH) catalyses the reversible conversion of glutamate into α-ketoglutarate with the concomitant reduction of NAD(P)(+) to NAD(P)H or vice versa. GDH activity is subject to complex allosteric regulation including substrate inhibition. To determine GDH kinetics in situ, we assessed the effects of various glutamate concentrations in combination with either the coenzyme NAD(+) or NADP(+) on GDH activity in mouse liver cryostat sections using metabolic mapping. NAD(+)-dependent GDH V(max) was 2.5-fold higher than NADP(+)-dependent V(max), whereas the K(m) was similar, 1.92 mM versus 1.66 mM, when NAD(+) or NADP(+) was used, respectively. With either coenzyme, V(max) was determined at 10 mM glutamate and substrate inhibition was observed at higher glutamate concentrations with a K(i) of 12.2 and 3.95 for NAD(+) and NADP(+) used as coenzyme, respectively. NAD(+)- and NADP(+)-dependent GDH activities were examined in various mouse tissues. GDH activity was highest in liver and much lower in other tissues. In all tissues, the highest activity was found when NAD(+) was used as a coenzyme. In conclusion, GDH activity in mice is highest in the liver with NAD(+) as a coenzyme and highest GDH activity was determined at a glutamate concentration of 10 mM. © The Author(s) 2014.

  9. Light wavelength dependency of mating activity in the drosophila melanogaster species subgroup

    International Nuclear Information System (INIS)

    Sakai, Takaomi; Tomaru, Masatoshi; Oguma, Yuzuru; Isono, Kunio; Fukatami, Akishi

    2002-01-01

    The action spectra of mating activity among the six species of the Drosophila melanogaster species subgroup were compared to understand how light wavelength affects mating activity. The species fell into three groups with respect to the action spectrum of mating activity. We chose one representative species from each of the three types for detailed study: D. melanogaster, D. sechellia and D. yakuba. The mating activities were investigated under three different light intensities of three monochromatic lights stimulus. Each species showed a unique spectral and intensity response. To know the evolutionary meaning of the light wavelength dependency of mating activity, we superimposed the type of action spectrum of mating activity in these six species on a cladogram. Mating inhibition under UV was conserved in evolution among these species. Furthermore we clarified that D. melanogaster showed low mating activity under UV because males courted less under UV. (author)

  10. Quantitative Proteomics Identifies Activation of Hallmark Pathways of Cancer in Patient Melanoma.

    Science.gov (United States)

    Byrum, Stephanie D; Larson, Signe K; Avaritt, Nathan L; Moreland, Linley E; Mackintosh, Samuel G; Cheung, Wang L; Tackett, Alan J

    2013-03-01

    Molecular pathways regulating melanoma initiation and progression are potential targets of therapeutic development for this aggressive cancer. Identification and molecular analysis of these pathways in patients has been primarily restricted to targeted studies on individual proteins. Here, we report the most comprehensive analysis of formalin-fixed paraffin-embedded human melanoma tissues using quantitative proteomics. From 61 patient samples, we identified 171 proteins varying in abundance among benign nevi, primary melanoma, and metastatic melanoma. Seventy-three percent of these proteins were validated by immunohistochemistry staining of malignant melanoma tissues from the Human Protein Atlas database. Our results reveal that molecular pathways involved with tumor cell proliferation, motility, and apoptosis are mis-regulated in melanoma. These data provide the most comprehensive proteome resource on patient melanoma and reveal insight into the molecular mechanisms driving melanoma progression.

  11. Quantitative measurement of membrane Na+-K+ ATPase activity using thallium-201: comparison with rubidium-86

    International Nuclear Information System (INIS)

    Lee, Jae Tae; Shon, Sang Kyun; Lee, Kyu Bo; Lee, In Kyu

    1998-01-01

    Na + -K + ATPase activity has been estimated by the degree of inhibition of cation transport by cardiac glycosides (ouabain) using Rb-86 as a substrate. The biological characteristics of Tl-201 is known to be similar to those of potassium as a transport substrate in the presence of glucose, insulin or phobol myristate acetate (PMA). The purpose of this study was to measure ouabain sensitive Na + -K + ATPase activity using Tl-201 and compare with that using Rb-86. Smooth muscle cells isolated from rat aorta or human placental umbilical artery were cultured, and used to measure cellular Na + -K + ATPase activity. Na + -K + ATPase activity was measured as a percentage decrease in cellular uptake of Tl-201 or Rb-86 by ouabain under the presence of glucose, insulin or PMA in media. Na + -K + ATPase activity measured with Tl-201, as a transport substrate, was not different from those measured with Rb-86 in rat or human smooth muscle cell preparation. Incubation with high concentration glucose resulted in about 30% decrease in enzyme activity. In contrast, insulin or PMA resulted in 50-70% or 28% increase from baseline activity, respectively. These results suggests that Tl-201 could replace Rb-86 in measurement of ouabain sensitive Na + -K + ATPase activity in vitro. High level of glucose concentration decreased cellular Na + -K + ATPase activity, but insulin or PMA increased it

  12. Non-linear quantitative structure-activity relationship for adenine derivatives as competitive inhibitors of adenosine deaminase

    International Nuclear Information System (INIS)

    Sadat Hayatshahi, Sayyed Hamed; Abdolmaleki, Parviz; Safarian, Shahrokh; Khajeh, Khosro

    2005-01-01

    Logistic regression and artificial neural networks have been developed as two non-linear models to establish quantitative structure-activity relationships between structural descriptors and biochemical activity of adenosine based competitive inhibitors, toward adenosine deaminase. The training set included 24 compounds with known k i values. The models were trained to solve two-class problems. Unlike the previous work in which multiple linear regression was used, the highest of positive charge on the molecules was recognized to be in close relation with their inhibition activity, while the electric charge on atom N1 of adenosine was found to be a poor descriptor. Consequently, the previously developed equation was improved and the newly formed one could predict the class of 91.66% of compounds correctly. Also optimized 2-3-1 and 3-4-1 neural networks could increase this rate to 95.83%

  13. Comparative study on economic security of enterprises depending on implemented business activities quantity

    OpenAIRE

    Shkarina Tatyana; Chudnova Olga; Mokhova Olga

    2017-01-01

    The results of a comparative study on economic security of enterprises depending on the quantity of business activities are published in the article. The sampling for analysis was conducted based on statistic data of Primorsky Region of the Russian Federation. The control points are the years of the most thorough data collection on the business activities of one-field and diversified enterprises: 2005, 2009, 2013, 2015.

  14. Methodology for Quantitative Analysis of Large Liquid Samples with Prompt Gamma Neutron Activation Analysis using Am-Be Source

    International Nuclear Information System (INIS)

    Idiri, Z.; Mazrou, H.; Beddek, S.; Amokrane, A.

    2009-01-01

    An optimized set-up for prompt gamma neutron activation analysis (PGNAA) with Am-Be source is described and used for large liquid samples analysis. A methodology for quantitative analysis is proposed: it consists on normalizing the prompt gamma count rates with thermal neutron flux measurements carried out with He-3 detector and gamma attenuation factors calculated using MCNP-5. The relative and absolute methods are considered. This methodology is then applied to the determination of cadmium in industrial phosphoric acid. The same sample is then analyzed by inductively coupled plasma (ICP) method. Our results are in good agreement with those obtained with ICP method.

  15. Obscure phenomena in statistical analysis of quantitative structure-activity relationships. Part 1: Multicollinearity of physicochemical descriptors.

    Science.gov (United States)

    Mager, P P; Rothe, H

    1990-10-01

    Multicollinearity of physicochemical descriptors leads to serious consequences in quantitative structure-activity relationship (QSAR) analysis, such as incorrect estimators and test statistics of regression coefficients of the ordinary least-squares (OLS) model applied usually to QSARs. Beside the diagnosis of the known simple collinearity, principal component regression analysis (PCRA) also allows the diagnosis of various types of multicollinearity. Only if the absolute values of PCRA estimators are order statistics that decrease monotonically, the effects of multicollinearity can be circumvented. Otherwise, obscure phenomena may be observed, such as good data recognition but low predictive model power of a QSAR model.

  16. Public open space characteristics influencing adolescents' use and physical activity: A systematic literature review of qualitative and quantitative studies.

    Science.gov (United States)

    Van Hecke, Linde; Ghekiere, Ariane; Veitch, Jenny; Van Dyck, Delfien; Van Cauwenberg, Jelle; Clarys, Peter; Deforche, Benedicte

    2018-04-06

    The objective of this systematic review was to provide insight into the specific characteristics of public open spaces (POS) associated with adolescents' POS visitation and physical activity (PA). Qualitative research suggests many characteristics to be associated with POS visitation and PA. Quantitative evidence confirmed a positive association between presence of trails, playgrounds and specific types of sports fields (e.g. basketball) with POS visitation and PA, whereas safety and aesthetics seemed subordinate. Suggestions for future research, as well as some methodological recommendations are provided. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Quantitative structure-activity relationship analysis to elucidate the clearance mechanisms of Tc-99m labeled quinolone antibiotics

    International Nuclear Information System (INIS)

    Salahinejad, M.; Mirshojaei, S.F.

    2016-01-01

    This study aims to establish molecular modeling methods for predicting the liver and kidney uptakes of Tc-99m labeled quinolone antibiotics. Some three-dimensional quantitative-activity relationships (3D-QSAR) models were developed using comparative molecular field analysis and grid-independent descriptors procedures. As a first report on 3D-QSAR modeling, the predicted liver and kidney uptakes for quinolone antibiotics were in good agreement with the experimental values. The obtained results confirm the importance of hydrophobic interactions, size and steric hindrance of antibiotic molecules in their liver uptakes, while the electrostatic interactions and hydrogen bonding ability have impressive effects on their kidney uptakes. (author)

  18. The Effect of Physical Activity on Children with ADHD: A Quantitative Review of the Literature

    Science.gov (United States)

    Cornelius, Colleen; Fedewa, Alicia L.; Ahn, Soyeon

    2017-01-01

    Research on the effects of physical activity on children with attention deficit hyperactivity disorder is promising, yet no attempt has been made to integrate current findings using meta-analytic techniques. Using a meta-regression, the present study examined the effectives of physical activity for children with attention deficit hyperactivity…

  19. A quantitative method for the specific assessment of caspase-6 activity in cell culture

    DEFF Research Database (Denmark)

    Ehrnhoefer, Dagmar E; Skotte, Niels H; Savill, Jane

    2011-01-01

    Aberrant activation of caspase-6 has recently emerged as a major contributor to the pathogeneses of neurodegenerative disorders such as Alzheimer's and Huntington disease. Commercially available assays to measure caspase-6 activity commonly use the VEID peptide as a substrate. However these metho...

  20. Quantitative imaging reveals heterogeneous growth dynamics and treatment-dependent residual tumor distributions in a three-dimensional ovarian cancer model

    Science.gov (United States)

    Celli, Jonathan P.; Rizvi, Imran; Evans, Conor L.; Abu-Yousif, Adnan O.; Hasan, Tayyaba

    2010-09-01

    Three-dimensional tumor models have emerged as valuable in vitro research tools, though the power of such systems as quantitative reporters of tumor growth and treatment response has not been adequately explored. We introduce an approach combining a 3-D model of disseminated ovarian cancer with high-throughput processing of image data for quantification of growth characteristics and cytotoxic response. We developed custom MATLAB routines to analyze longitudinally acquired dark-field microscopy images containing thousands of 3-D nodules. These data reveal a reproducible bimodal log-normal size distribution. Growth behavior is driven by migration and assembly, causing an exponential decay in spatial density concomitant with increasing mean size. At day 10, cultures are treated with either carboplatin or photodynamic therapy (PDT). We quantify size-dependent cytotoxic response for each treatment on a nodule by nodule basis using automated segmentation combined with ratiometric batch-processing of calcein and ethidium bromide fluorescence intensity data (indicating live and dead cells, respectively). Both treatments reduce viability, though carboplatin leaves micronodules largely structurally intact with a size distribution similar to untreated cultures. In contrast, PDT treatment disrupts micronodular structure, causing punctate regions of toxicity, shifting the distribution toward smaller sizes, and potentially increasing vulnerability to subsequent chemotherapeutic treatment.

  1. Wavelength-dependent backscattering measurements for quantitative monitoring of apoptosis, Part 1: early and late spectral changes are indicative of the presence of apoptosis in cell cultures

    Science.gov (United States)

    Mulvey, Christine S.; Zhang, Kexiong; Liu, Wei-Han Bobby; Waxman, David J.; Bigio, Irving J.

    2011-11-01

    Apoptosis, a form of programmed cell death with unique morphological and biochemical features, is dysregulated in cancer and is activated by many cancer chemotherapeutic drugs. Noninvasive assays for apoptosis in cell cultures can aid in screening of new anticancer agents. We have previously demonstrated that elastic scattering spectroscopy can monitor apoptosis in cell cultures. In this report we present data on monitoring the detailed time-course of scattering changes in a Chinese hamster ovary (CHO) and PC-3 prostate cancer cells treated with staurosporine to induce apoptosis. Changes in the backscattering spectrum are detectable within 10 min, and continue to progress up to 48 h after staurosporine treatment, with the magnitude and kinetics of scattering changes dependent on inducer concentration. Similar responses were observed in CHO cells treated with several other apoptosis-inducing protocols. Early and late scattering changes were observed under conditions shown to induce apoptosis via caspase activity assay and were absent under conditions where apoptosis was not induced. Finally, blocking caspase activity and downstream apoptotic morphology changes prevented late scattering changes. These observations demonstrate that early and late changes in wavelength-dependent backscattering correlate with the presence of apoptosis in cell cultures and that the late changes are specific to apoptosis.

  2. Control of neuropeptide expression by parallel activity-dependent pathways in caenorhabditis elegans

    DEFF Research Database (Denmark)

    Rojo Romanos, Teresa; Petersen, Jakob Gramstrup; Pocock, Roger

    2017-01-01

    Monitoring of neuronal activity within circuits facilitates integrated responses and rapid changes in behavior. We have identified a system in Caenorhabditis elegans where neuropeptide expression is dependent on the ability of the BAG neurons to sense carbon dioxide. In C. Elegans, CO 2 sensing...... is predominantly coordinated by the BAG-expressed receptor-type guanylate cyclase GCY-9. GCY-9 binding to CO 2 causes accumulation of cyclic GMP and opening of the cGMP-gated TAX-2/TAX-4 cation channels; provoking an integrated downstream cascade that enables C. Elegans to avoid high CO 2. Here we show that c...... that expression of flp-19::GFP is controlled in parallel to GCY-9 by the activity-dependent transcription factor CREB (CRH-1) and the cAMP-dependent protein kinase (KIN-2) signaling pathway. We therefore show that two parallel pathways regulate neuropeptide gene expression in the BAG sensory neurons: the ability...

  3. Macrophages migrate in an activation-dependent manner to chemokines involved in neuroinflammation

    NARCIS (Netherlands)

    Vogel, D.Y.S.; Heijnen, D.A.M.; Breur, M.; de Vries, H.E.; Tool, A.T.; Amor, S.; Dijkstra, C.D.

    2014-01-01

    Background: In neuroinflammatory diseases, macrophages can play a dual role in the process of tissue damage, depending on their activation status (M1 / M2). M1 macrophages are considered to exert damaging effects to neurons, whereas M2 macrophages are reported to aid regeneration and repair of

  4. Quantitative data analysis of perceived barriers and motivators to physical activity in stroke survivors.

    Science.gov (United States)

    Nicholson, S L; Greig, C A; Sniehotta, F; Johnston, M; Lewis, S J; McMurdo, M E; Johnston, D; Scopes, J; Mead, G E

    2017-09-01

    Levels of physical activity after stroke are low, despite multiple health benefits. We explored stroke survivors' perceived barriers, motivators, self-efficacy and intention to physical activity. Fifty independently mobile stroke survivors were recruited prior to hospital discharge. Participants rated nine possible motivators and four possible barriers based on the Mutrie Scale, as having 'no influence', 'some influence' or 'a major influence' on physical activity. Participants also rated their self-efficacy and intention to increasing walking. The most common motivator was 'physical activity is good for health' [34 (68%)]. The most common barrier was 'feeling too tired' [24 (48%)]. Intention and self-efficacy were high. Self-efficacy was graded as either 4 or 5 (highly confident) on a five-point scale by [34 (68%)] participants, while 42 (84%) 'strongly agreed' or 'agreed' that they intended to increase their walking. Participants felt capable of increasing physical activity but fatigue was often perceived as a barrier to physical activity. This needs to be considered when encouraging stroke survivors to be more active.

  5. Quantitative determination of uranium by SIMS

    International Nuclear Information System (INIS)

    Kuruc, J.; Harvan, D.; Galanda, D.; Matel, L.; Aranyosiova, M.; Velic, D.

    2008-01-01

    The paper presents results of quantitative measurements of uranium-238 by secondary ion mass spectrometry (SIMS) with using alpha spectrometry as well as complementary technique. Samples with specific activity of uranium-238 were prepared by electrodeposition from aqueous solution of UO 2 (NO 3 ) 2 ·6H 2 O. We tried to apply SIMS to quantitative analysis and search for correlation between intensity obtained from SIMS and activity of uranium-238 in dependence on the surface's weight and possibility of using SIMS in quantitative analysis of environmental samples. The obtained results and correlations as well as results of two real samples measurements are presented in this paper. (authors)

  6. TALE activators regulate gene expression in a position- and strand-dependent manner in mammalian cells.

    Science.gov (United States)

    Uhde-Stone, Claudia; Cheung, Edna; Lu, Biao

    2014-01-24

    Transcription activator-like effectors (TALEs) are a class of transcription factors that are readily programmable to regulate gene expression. Despite their growing popularity, little is known about binding site parameters that influence TALE-mediated gene activation in mammalian cells. We demonstrate that TALE activators modulate gene expression in mammalian cells in a position- and strand-dependent manner. To study the effects of binding site location, we engineered TALEs customized to recognize specific DNA sequences located in either the promoter or the transcribed region of reporter genes. We found that TALE activators robustly activated reporter genes when their binding sites were located within the promoter region. In contrast, TALE activators inhibited the expression of reporter genes when their binding sites were located on the sense strand of the transcribed region. Notably, this repression was independent of the effector domain utilized, suggesting a simple blockage mechanism. We conclude that TALE activators in mammalian cells regulate genes in a position- and strand-dependent manner that is substantially different from gene activation by native TALEs in plants. These findings have implications for optimizing the design of custom TALEs for genetic manipulation in mammalian cells. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Dependency of {gamma}-secretase complex activity on the structural integrity of the bilayer

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Hua, E-mail: hzhou2@lbl.gov [Life Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 (United States); Zhou, Shuxia; Walian, Peter J.; Jap, Bing K. [Life Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 (United States)

    2010-11-12

    Research highlights: {yields} Partial solubilization of membranes with CHAPSO can increase {gamma}-secretase activity. {yields} Completely solubilized {gamma}-secretase is inactive. {yields} Purified {gamma}-secretase regains activity after reconstitution into lipid bilayers. {yields} A broad range of detergents can be used to successfully reconstitute {gamma}-secretase. -- Abstract: {gamma}-secretase is a membrane protein complex associated with the production of A{beta} peptides that are pathogenic in Alzheimer's disease. We have characterized the activity of {gamma}-secretase complexes under a variety of detergent solubilization and reconstitution conditions, and the structural state of proteoliposomes by electron microscopy. We found that {gamma}-secretase activity is highly dependent on the physical state or integrity of the membrane bilayer - partial solubilization may increase activity while complete solubilization will abolish it. The activity of well-solubilized {gamma}-secretase can be restored to near native levels when properly reconstituted into a lipid bilayer environment.

  8. Dual core quantum dots for highly quantitative ratiometric detection of trypsin activity in cystic fibrosis patients

    Science.gov (United States)

    Castelló Serrano, Iván; Stoica, Georgiana; Matas Adams, Alba; Palomares, Emilio

    2014-10-01

    We present herein two colour encoded silica nanospheres (2nanoSi) for the fluorescence quantitative ratiometric determination of trypsin in humans. Current detection methods for cystic fibrosis diagnosis are slow, costly and suffer from false positives. The 2nanoSi proved to be a highly sensitive, fast (minutes), and single-step approach nanosensor for the screening and diagnosis of cystic fibrosis, allowing the quantification of trypsin concentrations in a wide range relevant for clinical applications (25-350 μg L-1). Furthermore, as trypsin is directly related to the development of cystic fibrosis (CF), different human genotypes, i.e. CF homozygotic, CF heterozygotic, and unaffected, respectively, can be determined using our 2nanoSi nanospheres. We anticipate the 2nanoSi system to be a starting point for non-invasive, easy-to-use and cost effective ratiometric fluorescent biomarkers for recessive genetic diseases like human cystic fibrosis. In a screening program in which the goal is to detect disease and also the carrier status, early diagnosis could be of great help.We present herein two colour encoded silica nanospheres (2nanoSi) for the fluorescence quantitative ratiometric determination of trypsin in humans. Current detection methods for cystic fibrosis diagnosis are slow, costly and suffer from false positives. The 2nanoSi proved to be a highly sensitive, fast (minutes), and single-step approach nanosensor for the screening and diagnosis of cystic fibrosis, allowing the quantification of trypsin concentrations in a wide range relevant for clinical applications (25-350 μg L-1). Furthermore, as trypsin is directly related to the development of cystic fibrosis (CF), different human genotypes, i.e. CF homozygotic, CF heterozygotic, and unaffected, respectively, can be determined using our 2nanoSi nanospheres. We anticipate the 2nanoSi system to be a starting point for non-invasive, easy-to-use and cost effective ratiometric fluorescent biomarkers for

  9. What environmental factors influence resumption of valued activities post stroke: a systematic review of qualitative and quantitative findings.

    Science.gov (United States)

    Jellema, Sandra; van Hees, Suzanne; Zajec, Jana; van der Sande, Rob; Nijhuis-van der Sanden, Maria Wg; Steultjens, Esther Mj

    2017-07-01

    Identify the environmental factors that influence stroke-survivors' reengagement in personally valued activities and determine what specific environmental factors are related to specific valued activity types. PubMed, CINAHL and PsycINFO were searched until June 2016 using multiple search-terms for stroke, activities, disability, and home and community environments. An integrated mixed-method systematic review of qualitative, quantitative and mixed-design studies was conducted. Two researchers independently identified relevant studies, assessed their methodological quality and extracted relevant findings. To validly compare and combine the various findings, all findings were classified and grouped by environmental category and level of evidence. The search yielded 4024 records; 69 studies were included. Most findings came from low-evidence-level studies such as single qualitative studies. All findings were consistent in that the following factors facilitated reengagement post-stroke: personal adapted equipment; accessible environments; transport; services; education and information. Barriers were: others' negative attitudes and behaviour; long distances and inconvenient environmental conditions (such as bad weather). Each type of valued activity, such as mobility or work, had its own pattern of environmental influences, social support was a facilitator to all types of activities. Although in many qualitative studies others' attitudes, behaviour and stroke-related knowledge were seen as important for reengagement, these factors were hardly studied quantitatively. A diversity of environmental factors was related to stroke-survivors' reengagement. Most findings came from low-evidence-level studies so that evidence on causal relationships was scarce. In future, more higher-level-evidence studies, for example on the attitudes of significant others, should be conducted.

  10. Constitutive NADPH-dependent electron transferase activity of the Nox4 dehydrogenase domain.

    Science.gov (United States)

    Nisimoto, Yukio; Jackson, Heather M; Ogawa, Hisamitsu; Kawahara, Tsukasa; Lambeth, J David

    2010-03-23

    NADPH oxidase 4 (Nox4) is constitutively active, while Nox2 requires the cytosolic regulatory subunits p47(phox) and p67(phox) and activated Rac with activation by phorbol 12-myristate 13-acetate (PMA). This study was undertaken to identify the domain on Nox4 that confers constitutive activity. Lysates from Nox4-expressing cells exhibited constitutive NADPH- but not NADH-dependent hydrogen peroxide production with a K(m) for NADPH of 55 +/- 10 microM. The concentration of Nox4 in cell lysates was estimated using Western blotting and allowed calculation of a turnover of approximately 200 mol of H(2)O(2) min(-1) (mol of Nox4)(-1). A chimeric protein (Nox2/4) consisting of the Nox2 transmembrane (TM) domain and the Nox4 dehydrogenase (DH) domain showed H(2)O(2) production in the absence of cytosolic regulatory subunits. In contrast, chimera Nox4/2, consisting of the Nox4 TM and Nox2 DH domains, exhibited PMA-dependent activation that required coexpression of regulatory subunits. Nox DH domains from several Nox isoforms were purified and evaluated for their electron transferase activities. Nox1 DH, Nox2 DH, and Nox5 DH domains exhibited barely detectable activities toward artificial electron acceptors, while the Nox4 DH domain exhibited significant rates of reduction of cytochrome c (160 min(-1), largely superoxide dismutase-independent), ferricyanide (470 min(-1)), and other electron acceptors (artificial dyes and cytochrome b(5)). Rates were similar to those observed for H(2)O(2) production by the Nox4 holoenzyme in cell lysates. The activity required added FAD and was seen with NADPH but not NADH. These results indicate that the Nox4 DH domain exists in an intrinsically activated state and that electron transfer from NADPH to FAD is likely to be rate-limiting in the NADPH-dependent reduction of oxygen by holo-Nox4.

  11. A Quantitative Review of Physical Activity, Health, and Learning Outcomes Associated with Classroom-Based Physical Activity Interventions

    Science.gov (United States)

    Erwin, Heather; Fedewa, Alicia; Beighle, Aaron; Ahn, Soyeon

    2012-01-01

    Research suggests that physical activity may foster improved academic performance, yet schools are receiving more pressure to achieve high academic standards. It is important for classroom teachers, administrators and school psychologists to understand the benefits of incorporating physical activity into the school day. This article serves as a…

  12. Hydrophilic Phage-Mimicking Membrane Active Antimicrobials Reveal Nanostructure-Dependent Activity and Selectivity.

    Science.gov (United States)

    Jiang, Yunjiang; Zheng, Wan; Kuang, Liangju; Ma, Hairong; Liang, Hongjun

    2017-09-08

    The prevalent wisdom on developing membrane active antimicrobials (MAAs) is to seek a delicate, yet unquantified, cationic-hydrophobic balance. Inspired by phages that use nanostructured protein devices to invade bacteria efficiently and selectively, we study here the antibiotic role of nanostructures by designing spherical and rod-like polymer molecular brushes (PMBs) that mimic the two basic structural motifs of bacteriophages. Three model PMBs with different well-defined geometries consisting of multiple, identical copies of densely packed poly(4-vinyl-N-methylpyridine iodide) branches are synthesized by controlled/"living" polymerization, reminiscent of the viral structural motifs comprised of multiple copies of protein subunits. We show that, while the individual linear-chain polymer branch that makes up the PMBs is hydrophilic and a weak antimicrobial, amphiphilicity is not a required antibiotic trait once nanostructures come into play. The nanostructured PMBs induce an unusual topological transition of bacterial but not mammalian membranes to form pores. The sizes and shapes of the nanostructures further help define the antibiotic activity and selectivity of the PMBs against different families of bacteria. This study highlights the importance of nanostructures in the design of MAAs with high activity, low toxicity, and target specificity.

  13. Anthropogenic activities and coastal environmental quality: a regional quantitative analysis in southeast China with management implications.

    Science.gov (United States)

    Chen, Kai; Liu, Yan; Huang, Dongren; Ke, Hongwei; Chen, Huorong; Zhang, Songbin; Yang, Shengyun; Cai, Minggang

    2018-02-01

    Regional analysis of environmental issues has always been a hot topic in the field of sustainable development. Because the different levels of economic growth, urbanization, resource endowments, etc. in different regions generate apparently different ecological responses, a better description and comparison across different regions will provide more valuable implications for ecological improvement and policymaking. In this study, seven typical bays in southeast China that are a rapid developing area were selected to quantitatively analyze the relationship between socioeconomic development and coastal environmental quality. Based on the water quality data from 2007 to 2015, the multivariate statistical method was applied to analyze the potential environmental risks and to classify the seven bays based on their environmental quality status. The possible variation trends of environmental indices were predicted based on the cross-regional panel data by Environmental Kuznets Curve. The results showed that there were significant regional differences among the seven bays, especially Quanzhou, Xiamen, and Luoyuan Bays, suffered from severer artificial disturbances than other bays, despite their different development patterns. Socioeconomic development level was significantly associated with some water quality indices (pH, DIN, PO 4 -P); the association was roughly positive: the areas with higher GDP per capita have some worse water quality indices. In addition, the decreasing trend of pH values and the increasing trend of nutrient concentration in the seven bays will continue in the foreseeable future. In consideration of the variation trends, the limiting nutrient strategy should be implemented to mitigate the deterioration of the coastal environments.

  14. Genotype modulates testosterone-dependent activity and reactivity in male mice.

    Science.gov (United States)

    Broida, J; Svare, B

    1983-03-01

    Adult castration significantly reduced the homecage locomotor activity of both inbred C57BL/6J and DBA/2J and outbred Rockland-Swiss (R-S) male mice. Castrated C57BL animals exhibited greater reductions in this behavior than did the other genotypes. Locomotor activity in a novel environment (reactivity) was also reduced by castration but only for inbred males. In both test situations, postcastration reductions in ambulation were prevented by implants of testosterone (T)-containing Silastic capsules. Thus, testicular hormones promote activity and reactivity in the male mouse in a genotype-dependent fashion.

  15. Physical activity level is impaired and diet dependent in preterm newborn pigs

    DEFF Research Database (Denmark)

    Cao, Muqing; Andersen, Anders Daniel; Van Ginneken, Chris

    2015-01-01

    and neonatal physical activity. METHODS: In experiment 1, preterm and term pigs were fed parenteral nutrition (PN) or PN plus bovine colostrum (BC, 16-64 ml/kg/d enterally) for 5 d. In experiment 2, preterm pigs were fed PN+BC or PN+formula for 5 d. In experiment 3, preterm pigs were fed BC, formula, or human...... feeding increased HCA, intestinal weights, and necrotizing enteritis resistance, relative to formula (experiment 3). CONCLUSION: Preterm pigs show decreased physical activity, and the first enteral feeds diet dependently stimulate both gut growth and physical activity. The effects may arise from...

  16. NPM1 directs PIDDosome-dependent caspase-2 activation in the nucleolus.

    Science.gov (United States)

    Ando, Kiyohiro; Parsons, Melissa J; Shah, Richa B; Charendoff, Chloé I; Paris, Sheré L; Liu, Peter H; Fassio, Sara R; Rohrman, Brittany A; Thompson, Ruth; Oberst, Andrew; Sidi, Samuel; Bouchier-Hayes, Lisa

    2017-06-05

    The PIDDosome (PIDD-RAIDD-caspase-2 complex) is considered to be the primary signaling platform for caspase-2 activation in response to genotoxic stress. Yet studies of PIDD-deficient mice show that caspase-2 activation can proceed in the absence of PIDD. Here we show that DNA damage induces the assembly of at least two distinct activation platforms for caspase-2: a cytoplasmic platform that is RAIDD dependent but PIDD independent, and a nucleolar platform that requires both PIDD and RAIDD. Furthermore, the nucleolar phosphoprotein nucleophosmin (NPM1) acts as a scaffold for PIDD and is essential for PIDDosome assembly in the nucleolus after DNA damage. Inhibition of NPM1 impairs caspase-2 processing, apoptosis, and caspase-2-dependent inhibition of cell growth, demonstrating that the NPM1-dependent nucleolar PIDDosome is a key initiator of the caspase-2 activation cascade. Thus we have identified the nucleolus as a novel site for caspase-2 activation and function. © 2017 Ando et al.

  17. Phospho-dependent Accumulation of GABABRs at Presynaptic Terminals after NMDAR Activation.

    Science.gov (United States)

    Hannan, Saad; Gerrow, Kim; Triller, Antoine; Smart, Trevor G

    2016-08-16

    Here, we uncover a mechanism for regulating the number of active presynaptic GABAB receptors (GABABRs) at nerve terminals, an important determinant of neurotransmitter release. We find that GABABRs gain access to axon terminals by lateral diffusion in the membrane. Their relative accumulation is dependent upon agonist activation and the presence of the two distinct sushi domains that are found only in alternatively spliced GABABR1a subunits. Following brief activation of NMDA receptors (NMDARs) using glutamate, GABABR diffusion is reduced, causing accumulation at presynaptic terminals in a Ca(2+)-dependent manner that involves phosphorylation of GABABR2 subunits at Ser783. This signaling cascade indicates how synaptically released glutamate can initiate, via a feedback mechanism, increased levels of presynaptic GABABRs that limit further glutamate release and excitotoxicity. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  18. Structures of apicomplexan calcium-dependent protein kinases reveal mechanism of activation by calcium

    Energy Technology Data Exchange (ETDEWEB)

    Wernimont, Amy K; Artz, Jennifer D.; Jr, Patrick Finerty; Lin, Yu-Hui; Amani, Mehrnaz; Allali-Hassani, Abdellah; Senisterra, Guillermo; Vedadi, Masoud; Tempel, Wolfram; Mackenzie, Farrell; Chau, Irene; Lourido, Sebastian; Sibley, L. David; Hui, Raymond (Toronto); (WU-MED)

    2010-09-21

    Calcium-dependent protein kinases (CDPKs) have pivotal roles in the calcium-signaling pathway in plants, ciliates and apicomplexan parasites and comprise a calmodulin-dependent kinase (CaMK)-like kinase domain regulated by a calcium-binding domain in the C terminus. To understand this intramolecular mechanism of activation, we solved the structures of the autoinhibited (apo) and activated (calcium-bound) conformations of CDPKs from the apicomplexan parasites Toxoplasma gondii and Cryptosporidium parvum. In the apo form, the C-terminal CDPK activation domain (CAD) resembles a calmodulin protein with an unexpected long helix in the N terminus that inhibits the kinase domain in the same manner as CaMKII. Calcium binding triggers the reorganization of the CAD into a highly intricate fold, leading to its relocation around the base of the kinase domain to a site remote from the substrate binding site. This large conformational change constitutes a distinct mechanism in calcium signal-transduction pathways.

  19. Cell number and transfection volume dependent peptide nucleic acid antisense activity by cationic delivery methods

    DEFF Research Database (Denmark)

    Llovera Nadal, Laia; Berthold, Peter; Nielsen, Peter E

    2012-01-01

    have now quantitatively compared the cellular activity (in the pLuc705 HeLa cell splice correction system) of PNA antisense oligomers using lipoplex delivery of cholesterol- and bisphosphonate-PNA conjugates, polyplex delivery via a PNA-polyethyleneimine conjugate and CPP delivery via a PNA......Efficient intracellular delivery is essential for high activity of nucleic acids based therapeutics, including antisense agents. Several strategies have been developed and practically all rely on auxiliary transfection reagents such as cationic lipids, cationic polymers and cell penetrating...... peptides as complexing agents and carriers of the nucleic acids. However, uptake mechanisms remain rather poorly understood, and protocols always require optimization of transfection parameters. Considering that cationic transfection complexes bind to and thus may up-concentrate on the cell surface, we...

  20. Fragment-based quantitative structure-activity relationship (FB-QSAR) for fragment-based drug design.

    Science.gov (United States)

    Du, Qi-Shi; Huang, Ri-Bo; Wei, Yu-Tuo; Pang, Zong-Wen; Du, Li-Qin; Chou, Kuo-Chen

    2009-01-30

    In cooperation with the fragment-based design a new drug design method, the so-called "fragment-based quantitative structure-activity relationship" (FB-QSAR) is proposed. The essence of the new method is that the molecular framework in a family of drug candidates are divided into several fragments according to their substitutes being investigated. The bioactivities of molecules are correlated with the physicochemical properties of the molecular fragments through two sets of coefficients in the linear free energy equations. One coefficient set is for the physicochemical properties and the other for the weight factors of the molecular fragments. Meanwhile, an iterative double least square (IDLS) technique is developed to solve the two sets of coefficients in a training data set alternately and iteratively. The IDLS technique is a feedback procedure with machine learning ability. The standard Two-dimensional quantitative structure-activity relationship (2D-QSAR) is a special case, in the FB-QSAR, when the whole molecule is treated as one entity. The FB-QSAR approach can remarkably enhance the predictive power and provide more structural insights into rational drug design. As an example, the FB-QSAR is applied to build a predictive model of neuraminidase inhibitors for drug development against H5N1 influenza virus. (c) 2008 Wiley Periodicals, Inc.

  1. Quantitative evaluation of indium-111 (In-111) octreotide pituitary activity: Comparison in patient with and without pituitary tumors

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, P.; Waxman, A.; Nguyen, K. [Cedars-Sinai Medical Center, Los Angeles, CA (United States)] [and others

    1995-05-01

    Indium 111 Octreotide is known to detect pituitary tumors. Variable low level pituitary activity has been reported in pts. with no demonstrable pituitary tumors. To our knowledge, there have been no studies which quantitatively categorize pituitary activity with respect to distinguishing normal subject from pts. with pituitary tumors. 13 pts. with proven, treated acromegaly were included, as well as 15 pts. with no history of pituitary disorder. Both groups underwent SPECT In-111 scintigraphy 24 hours post-injection Average count per pixel ratios were obtained for the pituitary/calvarium (P/C) and pituitary/brain (P/B) regions. 10 pts. with acromegaly underwent growth hormone (GH) measurements 2 hours post-glucose load. Statistical correlation between growth hormone levels using P/C and P/B ratios were obtained. P/C ratios, as well as P/B ratios demonstrated high correlation with serum GH levels correlation coefficient(r)= .717 for P/C p<0.05, and correlation coefficient(r) = 0.828 for P/B ratios p<0.005. P/C ratios and P/B ratios for controls correlated closely with the upper level of normal predicted by P/C or P/B ratios as a function of serum growth hormone found in patients with acromegaly. Somatostatin receptor SPECT scintigraphy of the pituitary and appropriate quantitation can predict patients with growth hormone secreting tumors.

  2. Novel Uses of In Vitro Data to Develop Quantitative Biological Activity Relationship Models for in Vivo Carcinogenicity Prediction.

    Science.gov (United States)

    Pradeep, Prachi; Povinelli, Richard J; Merrill, Stephen J; Bozdag, Serdar; Sem, Daniel S

    2015-04-01

    The availability of large in vitro datasets enables better insight into the mode of action of chemicals and better identification of potential mechanism(s) of toxicity. Several studies have shown that not all in vitro assays can contribute as equal predictors of in vivo carcinogenicity for development of hybrid Quantitative Structure Activity Relationship (QSAR) models. We propose two novel approaches for the use of mechanistically relevant in vitro assay data in the identification of relevant biological descriptors and development of Quantitative Biological Activity Relationship (QBAR) models for carcinogenicity prediction. We demonstrate that in vitro assay data can be used to develop QBAR models for in vivo carcinogenicity prediction via two case studies corroborated with firm scientific rationale. The case studies demonstrate the similarities between QBAR and QSAR modeling in: (i) the selection of relevant descriptors to be used in the machine learning algorithm, and (ii) the development of a computational model that maps chemical or biological descriptors to a toxic endpoint. The results of both the case studies show: (i) improved accuracy and sensitivity which is especially desirable under regulatory requirements, and (ii) overall adherence with the OECD/REACH guidelines. Such mechanism based models can be used along with QSAR models for prediction of mechanistically complex toxic endpoints. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Imidazole-containing farnesyltransferase inhibitors: 3D quantitative structure-activity relationships and molecular docking

    Science.gov (United States)

    Xie, Aihua; Odde, Srinivas; Prasanna, Sivaprakasam; Doerksen, Robert J.

    2009-07-01

    One of the most promising anticancer and recent antimalarial targets is the heterodimeric zinc-containing protein farnesyltransferase (FT). In this work, we studied a highly diverse series of 192 Abbott-initiated imidazole-containing compounds and their FT inhibitory activities using 3D-QSAR and docking, in order to gain understanding of the interaction of these inhibitors with FT to aid development of a rational strategy for further lead optimization. We report several highly significant and predictive CoMFA and CoMSIA models. The best model, composed of CoMFA steric and electrostatic fields combined with CoMSIA hydrophobic and H-bond acceptor fields, had r 2 = 0.878, q 2 = 0.630, and r pred 2 = 0.614. Docking studies on the statistical outliers revealed that some of them had a different binding mode in the FT active site based on steric bulk and available active site space, explaining why the predicted activities differed from the experimental activities.

  4. Quantitative Analysis of Major Constituents in Green Tea with Different Plucking Periods and Their Antioxidant Activity

    Directory of Open Access Journals (Sweden)

    Lan-Sook Lee

    2014-07-01

    Full Text Available The objective of this study was to determine the relationship between the plucking periods and the major constituents and the antioxidant activity in green tea. Green tea was prepared from leaves plucked from the end of April 2013 to the end of May 2013 at intervals of one week or longer. The contents of theanine, theobromine, caffeine, catechin (C, and gallocatechin gallate (GCg were significantly decreased, whereas those of epicatechin (EC, epigallocatechin gallate (EGCg and epigallocatechin (EGC were significantly increased along with the period of tea leaf plucking. In addition, antioxidant activity of green tea and standard catechins was investigated using ABTS, FRAP and DPPH assays. The highest antioxidant activity was observed in relatively the oldest leaf, regardless of the assay methods used. Additionally, the order of antioxidant activity of standard catechins was as follows: EGCg ³ GCg ³ ECg > EGC ³ GC ³ EC ³ C. Moreover, the cis-catechins contents were the key factor affecting the antioxidant activity of green tea in all assays employed (ABTS, r = 0.731, p < 0.01; FRAP, r = 0.886, p < 0.01; DPPH, r = 0.778, p < 0.01.

  5. AM fungal exudates activate MAP kinases in plant cells in dependence from cytosolic Ca(2+) increase.

    Science.gov (United States)

    Francia, Doriana; Chiltz, Annick; Lo Schiavo, Fiorella; Pugin, Alain; Bonfante, Paola; Cardinale, Francesca

    2011-09-01

    The molecular dialogue occurring prior to direct contact between the fungal and plant partners of arbuscular-mycorrhizal (AM) symbioses begins with the release of fungal elicitors, so far only partially identified chemically, which can activate specific signaling pathways in the host plant. We show here that the activation of MAPK is also induced by exudates of germinating spores of Gigaspora margarita in cultured cells of the non-leguminous species tobacco (Nicotiana tabacum), as well as in those of the model legume Lotus japonicus. MAPK activity peaked about 15 min after the exposure of the host cells to the fungal exudates (FE). FE were also responsible for a rapid and transient increase in free cytosolic Ca(2+) in Nicotiana plumbaginifolia and tobacco cells, and pre-treatment with a Ca(2+)-channel blocker (La(3+)) showed that in these cells, MAPK activation was dependent on the cytosolic Ca(2+) increase. A partial dependence of MAPK activity on the common Sym pathway could be demonstrated for a cell line of L. japonicus defective for LjSym4 and hence unable to establish an AM symbiosis. Our results show that MAPK activation is triggered by an FE-induced cytosolic Ca(2+) transient, and that a Sym genetic determinant acts to modulate the intensity and duration of this activity. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  6. Activity-Dependent IGF-1 Exocytosis is Controlled by the Ca2+-Sensor Synaptotagmin-10

    Science.gov (United States)

    Cao, Peng; Maximov, Anton; Südhof, Thomas C.

    2011-01-01

    Synaptotagmins Syt1, Syt2, Syt7, and Syt9 act as Ca2+-sensors for synaptic and neuroendocrine exocytosis, but the function of other synaptotagmins remains unknown. Here, we show that olfactory bulb neurons secrete IGF-1 by an activity-dependent pathway of exocytosis, and that Syt10 functions as the Ca2+-sensor that triggers IGF-1 exocytosis in these neurons. Deletion of Syt10 impaired activity-dependent IGF-1 secretion in olfactory bulb neurons, resulting in smaller neurons and an overall decrease in synapse numbers. Exogenous IGF-1 completely reversed the Syt10 knockout phenotype. Syt10 co-localized with IGF-1 in somatodendritic vesicles of olfactory bulb neurons, and Ca2+-binding to Syt10 caused these vesicles to undergo exocytosis, thereby secreting IGF-1. Thus, Syt10 controls a previously unrecognized pathway of Ca2+-dependent exocytosis that is spatially and temporally distinct from Ca2+-dependent synaptic vesicle exocytosis controlled by Syt1 in the same neurons, and two different synaptotagmins regulate distinct Ca2+-dependent membrane fusion reactions during exocytosis in the same neuron. PMID:21496647

  7. Long lasting protein synthesis- and activity-dependent spine shrinkage and elimination after synaptic depression.

    Directory of Open Access Journals (Sweden)

    Yazmín Ramiro-Cortés

    Full Text Available Neuronal circuits modify their response to synaptic inputs in an experience-dependent fashion. Increases in synaptic weights are accompanied by structural modifications, and activity dependent, long lasting growth of dendritic spines requires new protein synthesis. When multiple spines are potentiated within a dendritic domain, they show dynamic structural plasticity changes, indicating that spines can undergo bidirectional physical modifications. However, it is unclear whether protein synthesis dependent synaptic depression leads to long lasting structural changes. Here, we investigate the structural correlates of protein synthesis dependent long-term depression (LTD mediated by metabotropic glutamate receptors (mGluRs through two-photon imaging of dendritic spines on hippocampal pyramidal neurons. We find that induction of mGluR-LTD leads to robust and long lasting spine shrinkage and elimination that lasts for up to 24 hours. These effects depend on signaling through group I mGluRs, require protein synthesis, and activity. These data reveal a mechanism for long lasting remodeling of synaptic inputs, and offer potential insights into mental retardation.

  8. Latitude dependence of long-term geomagnetic activity and its solar wind drivers

    Energy Technology Data Exchange (ETDEWEB)

    Myllys, M. [Helsinki Univ. (Finland). Dept. of Physics; Partamies, N. [Finnish Meteorological Institute, Helsinki (Finland); University Centre in Svalbard, Longyearbyen (Norway). Dept. of Arctic Geophysics; Juusola, L. [Finnish Meteorological Institute, Helsinki (Finland)

    2015-09-01

    To validate the usage of global indices in studies of geomagnetic activity, we have examined the latitude dependence of geomagnetic variations in Fennoscandia and Svalbard from 1994 to 2010. Daily standard deviation (SD) values of the horizontal magnetic field have been used as a measure of the ground magnetic disturbance level.We found that the timing of the geomagnetic minimum depends on the latitude region: corresponding to the minimum of sunspot cycle 22 (in 1996), the geomagnetic minimum occurred between the geomagnetic latitudes 57-61 in 1996 and at the latitudes 64-67 in 1997, which are the average auroral oval latitudes. During sunspot cycle 23, all latitude regions experienced the minimum in 2009, a year after the sunspot minimum. These timing differences are due to the latitude dependence of the 10 s daily SD on the different solar wind drivers. In the latitude region of 64-67 , the impact of the high-speed solar wind streams (HSSs) on the geomagnetic activity is the most pronounced compared to the other latitude groups, while in the latitude region of 57-61 , the importance of the coronal mass ejections (CMEs) dominates. The geomagnetic activity maxima during ascending solar cycle phases are typically caused by CME activity and occur especially in the oval and sub-auroral regions. The strongest geomagnetic activity occurs during the descending solar cycle phases due to a mixture of CME and HSS activity. Closer to the solar minimum, less severe geomagnetic activity is driven by HSSs and mainly visible in the poleward part of the auroral region. According to our study, however, the timing of the geomagnetic activity minima (and maxima) in different latitude bands is different, due to the relative importance of different solar wind drivers at different latitudes.

  9. Temperature dependence of the activity of polyphenol peroxidases and polyphenol oxidases in modern and buried soils

    Science.gov (United States)

    Yakushev, A. V.; Kuznetsova, I. N.; Blagodatskaya, E. V.; Blagodatsky, S. A.

    2014-05-01

    Under conditions of the global climate warming, the changes in the reserves of soil humus depend on the temperature sensitivities of polyphenol peroxidases (PPPOs) and polyphenol oxidases (PPOs). They play an important role in lignin decomposition, mineralization, and humus formation. The temperature dependence of the potential enzyme activity in modern and buried soils has been studied during incubation at 10 or 20°C. The experimental results indicate that it depends on the availability of the substrate and the presence of oxygen. The activity of PPOs during incubation in the absence of oxygen for two months decreases by 2-2.5 times, which is balanced by an increase in the activity of PPPOs by 2-3 times. The increase in the incubation temperature to 20°C and the addition of glucose accelerates this transition due to the more abrupt decrease in the activity of PPOs. The preincubation of the soil with glucose doubles the activity of PPPOs but has no significant effect on the activity of PPOs. The different effects of temperature on two groups of the studied oxidases and the possibility of substituting enzymes by those of another type under changing aeration conditions should be taken into consideration in predicting the effect of the climate warming on the mineralization of the soil organic matter. The absence of statistically significant differences in the enzymatic activity between the buried and modern soil horizons indicates the retention by the buried soil of some of its properties (soil memory) and the rapid restoration of high enzymatic activity during the preincubation.

  10. Latitude dependence of long-term geomagnetic activity and its solar wind drivers

    International Nuclear Information System (INIS)

    Myllys, M.

    2015-01-01

    To validate the usage of global indices in studies of geomagnetic activity, we have examined the latitude dependence of geomagnetic variations in Fennoscandia and Svalbard from 1994 to 2010. Daily standard deviation (SD) values of the horizontal magnetic field have been used as a measure of the ground magnetic disturbance level.We found that the timing of the geomagnetic minimum depends on the latitude region: corresponding to the minimum of sunspot cycle 22 (in 1996), the geomagnetic minimum occurred between the geomagnetic latitudes 57-61 in 1996 and at the latitudes 64-67 in 1997, which are the average auroral oval latitudes. During sunspot cycle 23, all latitude regions experienced the minimum in 2009, a year after the sunspot minimum. These timing differences are due to the latitude dependence of the 10 s daily SD on the different solar wind drivers. In the latitude region of 64-67 , the impact of the high-speed solar wind streams (HSSs) on the geomagnetic activity is the most pronounced compared to the other latitude groups, while in the latitude region of 57-61 , the importance of the coronal mass ejections (CMEs) dominates. The geomagnetic activity maxima during ascending solar cycle phases are typically caused by CME activity and occur especially in the oval and sub-auroral regions. The strongest geomagnetic activity occurs during the descending solar cycle phases due to a mixture of CME and HSS activity. Closer to the solar minimum, less severe geomagnetic activity is driven by HSSs and mainly visible in the poleward part of the auroral region. According to our study, however, the timing of the geomagnetic activity minima (and maxima) in different latitude bands is different, due to the relative importance of different solar wind drivers at different latitudes.

  11. Antinociceptive Activity of Stephanolepis hispidus Skin Aqueous Extract Depends Partly on Opioid System Activation

    Directory of Open Access Journals (Sweden)

    Hugo Castro-Faria-Neto

    2013-04-01

    Full Text Available Stephanolepis hispidus is one of the most common filefish species in Brazil. Its skin is traditionally used as a complementary treatment for inflammatory disorders. However, there are very few studies on chemical and pharmacological properties using the skin of this fish. This study was undertaken in order to investigate the effect of aqueous crude extract of S. hispidus skin (SAE in different nociception models. Here, we report that intraperitoneal administration of SAE inhibited the abdominal constrictions induced by acetic acid in mice. In addition to the effect seen in the abdominal constriction model, SAE was also able to inhibit the hyperalgesia induced by carrageenan and prostaglandin E2 (PGE2 in mice. This potent antinociceptive effect was observed in the hot plate model too, but not in tail-flick test. Naloxone, an opioid receptor antagonist, was able to block the antinociceptive effect of SAE in the abdominal constriction and hot plate models. In addition, SAE did not present cytotoxic or genotoxic effect in human peripheral blood cells. Our results suggest that aqueous crude extract from S. hispidus skin has antinociceptive activity in close relationship with the partial activation of opioid receptors in the nervous system. Moreover, aqueous crude extract from S. hispidus skin does not present toxicity and is therefore endowed with the potential for pharmacological control of pain.

  12. Aldose Reductase Inhibitor Protects against Hyperglycemic Stress by Activating Nrf2-Dependent Antioxidant Proteins

    Directory of Open Access Journals (Sweden)

    Kirtikar Shukla

    2017-01-01

    Full Text Available We have shown earlier that pretreatment of cultured cells with aldose reductase (AR inhibitors prevents hyperglycemia-induced mitogenic and proinflammatory responses. However, the effects of AR inhibitors on Nrf2-mediated anti-inflammatory responses have not been elucidated yet. We have investigated how AR inhibitor fidarestat protects high glucose- (HG- induced cell viability changes by increasing the expression of Nrf2 and its dependent phase II antioxidant enzymes. Fidarestat pretreatment prevents HG (25 mM-induced Thp1 monocyte viability. Further, treatment of Thp1 monocytes with fidarestat caused a time-dependent increase in the expression as well as the DNA-binding activity of Nrf2. In addition, fidarestat augmented the HG-induced Nrf2 expression and activity and also upregulated the expression of Nrf2-dependent proteins such as hemeoxygenase-1 (HO1 and NQO1 in Thp1 cells. Similarly, treatment with AR inhibitor also induced the expression of Nrf2 and HO1 in STZ-induced diabetic mice heart and kidney tissues. Further, AR inhibition increased the HG-induced expression of antioxidant enzymes such as SOD and catalase and activation of AMPK-α1 in Thp1 cells. Our results thus suggest that pretreatment with AR inhibitor prepares the monocytes against hyperglycemic stress by overexpressing the Nrf2-dependent antioxidative proteins.

  13. Aldose Reductase Inhibitor Protects against Hyperglycemic Stress by Activating Nrf2-Dependent Antioxidant Proteins.

    Science.gov (United States)

    Shukla, Kirtikar; Pal, Pabitra Bikash; Sonowal, Himangshu; Srivastava, Satish K; Ramana, Kota V

    2017-01-01

    We have shown earlier that pretreatment of cultured cells with aldose reductase (AR) inhibitors prevents hyperglycemia-induced mitogenic and proinflammatory responses. However, the effects of AR inhibitors on Nrf2-mediated anti-inflammatory responses have not been elucidated yet. We have investigated how AR inhibitor fidarestat protects high glucose- (HG-) induced cell viability changes by increasing the expression of Nrf2 and its dependent phase II antioxidant enzymes. Fidarestat pretreatment prevents HG (25 mM)-induced Thp1 monocyte viability. Further, treatment of Thp1 monocytes with fidarestat caused a time-dependent increase in the expression as well as the DNA-binding activity of Nrf2. In addition, fidarestat augmented the HG-induced Nrf2 expression and activity and also upregulated the expression of Nrf2-dependent proteins such as hemeoxygenase-1 (HO1) and NQO1 in Thp1 cells. Similarly, treatment with AR inhibitor also induced the expression of Nrf2 and HO1 in STZ-induced diabetic mice heart and kidney tissues. Further, AR inhibition increased the HG-induced expression of antioxidant enzymes such as SOD and catalase and activation of AMPK- α 1 in Thp1 cells. Our results thus suggest that pretreatment with AR inhibitor prepares the monocytes against hyperglycemic stress by overexpressing the Nrf2-dependent antioxidative proteins.

  14. The effect of sports activities in children and adolescents on the calcaneus - an investigation with quantitative ultrasound

    International Nuclear Information System (INIS)

    Mentzel, H.J.; Malich, A.; Boettcher, J.; Vogt, S.; Kaiser, W.A.; Wuensche, K.

    2005-01-01

    Purpose: To determine whether quantitative ultrasound (QUS) parameters speed of sound (SOS) and broadband ultrasound attenuation (BUA) on the calcaneus are different between athletic children and a reference population. Patients and Methods: From a college of physical education, 177 children and adolescents (121 boys and 56 girls, age range from 11 to 18 years) were included in this study. QUS was performed on the calcaneus using the Sahara trademark device (Hologic, USA). SOS and BUA were estimated. Regional reference values of 3299 children were used to determine significant differences between athletes and reference population. The influence of activity level, age, height, and weight was estimated using correlation analysis. Results: Sportsmen showed significant (p<0.05) higher values of the QUS parameters (SOS 1581.1 m/s; BUA 69.7 dB/MHz) compared to the reference data (SOS 1563.9 m/s; BUA 64.2 dB/MHz). Significant correlation was observed between BUA and the level of activity, age, weight, and height (p<0.01) and between SOS and weight and height (p<0.05). In the group of soccer players and athletes, significant correlation was found between BUA vs. age and BUA vs. weight (p<0.05). Furthermore, significant correlation was observed between BUA vs. age and weight in Judokas and Wrestlers. For the level of activity, a significant correlation to BUA was only found in the group of Judokas and Wrestlers (p<0.01). Conclusion: An increase in quantitative ultrasound parameters on the calcaneus occurs in children and adolescents with increased physical activity. (orig.)

  15. Quantitative structure-activity relationships (QSAR) of 4-amino-2,6-diarylpyrimidine-5-carbonitriles with anti-inflammatory activity

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Joao Bosco P. da; Ramos, Mozart N.; Barros Neto, Benicio de [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Quimica Fundamental]. E-mail: mramos@ufpe.br; Melo, Sebastiao Jose de [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Antibioticos]. E-mail: melosebastiao@yahoo.com.br; Falcao, Emerson Peter da Silva [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Centro Academico de Vitoria de Santo Antao; Catanho, Maria Teresa J. de Almeida [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia

    2008-07-01

    The experimental anti-inflammatory activities of eight 4-amino-2,6-diarylpyrimidine-5- carbonitriles were subjected to a QSAR analysis based on results from B3LYP/6-31G(d,p) and AM1 electronic structure calculations. Principal component analyses and regressions based on these data indicate that potentially more active compounds should have low dipole moment and partition coefficient values and also be affected by the values of the charges of the carbon atoms through which the two aromatic rings are bonded to the pyrimidinic ring. Two new molecules were predicted to be at least as active as those with the highest activities used in the model building stage. One of them, having a methoxy group attached to one of the aromatic rings, was predicted to have an anti-inflammatory activity value of 52.3%. This molecule was synthesized and its experimental activity was found to be 52.8%, in agreement with the AM1 theoretical prediction. This value is 5% higher than the largest value used for modeling. (author)

  16. Quantitative structure-activity relationships (QSAR) of 4-amino-2,6-diarylpyrimidine-5-carbonitriles with anti-inflammatory activity

    International Nuclear Information System (INIS)

    Silva, Joao Bosco P. da; Ramos, Mozart N.; Barros Neto, Benicio de; Melo, Sebastiao Jose de; Falcao, Emerson Peter da Silva; Catanho, Maria Teresa J. de Almeida

    2008-01-01

    The experimental anti-inflammatory activities of eight 4-amino-2,6-diarylpyrimidine-5- carbonitriles were subjected to a QSAR analysis based on results from B3LYP/6-31G(d,p) and AM1 electronic structure calculations. Principal component analyses and regressions based on these data indicate that potentially more active compounds should have low dipole moment and partition coefficient values and also be affected by the values of the charges of the carbon atoms through which the two aromatic rings are bonded to the pyrimidinic ring. Two new molecules were predicted to be at least as active as those with the highest activities used in the model building stage. One of them, having a methoxy group attached to one of the aromatic rings, was predicted to have an anti-inflammatory activity value of 52.3%. This molecule was synthesized and its experimental activity was found to be 52.8%, in agreement with the AM1 theoretical prediction. This value is 5% higher than the largest value used for modeling. (author)

  17. pH-dependent biotransformation of ionizable organic micropollutants in activated sludge.

    Science.gov (United States)

    Gulde, Rebekka; Helbling, Damian E; Scheidegger, Andreas; Fenner, Kathrin

    2014-12-02

    Removal of micropollutants (MPs) during activated sludge treatment can mainly be attributed to biotransformation and sorption to sludge flocs, whereby the latter process is known to be of minor importance for polar organic micropollutants. In this work, we investigated the influence of pH on the biotransformation of MPs with cationic-neutral speciation in an activated sludge microbial community. We performed batch biotransformation, sorption control, and abiotic control experiments for 15 MPs with cationic-neutral speciation, one control MP with neutral-anionic speciation, and two neutral MPs at pHs 6, 7, and 8. Biotransformation rate constants corrected for sorption and abiotic processes were estimated from measured concentration time series with Bayesian inference. We found that biotransformation is pH-dependent and correlates qualitatively with the neutral fraction of the ionizable MPs. However, a simple speciation model based on the assumption that only the neutral species is efficiently taken up and biotransformed by the cells tends to overpredict the effect of speciation. Therefore, additional mechanisms such as uptake of the ionic species and other more complex attenutation mechanisms are discussed. Finally, we observed that the sorption coefficients derived from our control experiments were small and showed no notable pH-dependence. From this we conclude that pH-dependent removal of polar, ionizable organic MPs in activated sludge systems is less likely an effect of pH-dependent sorption but rather of pH-dependent biotransformation. The latter has the potential to cause marked differences in the removal of polar, ionizable MPs at different operational pHs during activated sludge treatment.

  18. Activation of Cyclin-Dependent Kinase 5 Is a Consequence of Cell Death

    Directory of Open Access Journals (Sweden)

    Yixia Ye

    2009-01-01

    Full Text Available Cyclin-dependent kinase 5 (Cdk5 is similar to other Cdks but is activated during cell differentiation and cell death rather than cell division. Since activation of Cdk5 has been reported in many situations leading to cell death, we attempted to determine if it was required for any form of cell death. We found that Cdk5 is activated during apoptotic deaths and that the activation can be detected even when the cells continue to secondary necrosis. This activation can occur in the absence of Bim, calpain, or neutral cathepsins. The kinase is typically activated by p25, derived from p35 by calpain-mediated cleavage, but inhibition of calpain does not affect cell death or the activation of Cdk5. Likewise, RNAi-forced suppression of the synthesis of Cdk5 does not affect the incidence or kinetics of cell death. We conclude that Cdk5 is activated as a consequence of metabolic changes that are common to many forms of cell death. Thus its activation suggests processes during cell death that will be interesting or important to understand, but activation of Cdk5 is not necessary for cells to die.

  19. State-dependent, bidirectional modulation of neural network activity by endocannabinoids.

    Science.gov (United States)

    Piet, Richard; Garenne, André; Farrugia, Fanny; Le Masson, Gwendal; Marsicano, Giovanni; Chavis, Pascale; Manzoni, Olivier J

    2011-11-16

    The endocannabinoid (eCB) system and the cannabinoid CB1 receptor (CB1R) play key roles in the modulation of brain functions. Although actions of eCBs and CB1Rs are well described at the synaptic level, little is known of their modulation of neural activity at the network level. Using microelectrode arrays, we have examined the role of CB1R activation in the modulation of the electrical activity of rat and mice cortical neural networks in vitro. We find that exogenous activation of CB1Rs expressed on glutamatergic neurons decreases the spontaneous activity of cortical neural networks. Moreover, we observe that the net effect of the CB1R antagonist AM251 inversely correlates with the initial level of activity in the network: blocking CB1Rs increases network activity when basal network activity is low, whereas it depresses spontaneous activity when its initial level is high. Our results reveal a complex role of CB1Rs in shaping spontaneous network activity, and suggest that the outcome of endogenous neuromodulation on network function might be state dependent.

  20. Quantitation of the degree of osteoporosis by measure of total-body calcium employing neutron activation

    International Nuclear Information System (INIS)

    Cohn, S.H.; Zanzi, I.; Vaswani, A.; Wallach, S.; Aloia, J.; Ellis, K.J.

    1975-01-01

    Two techniques for measuring the amount of Ca in the total skeleton were employed: total-body neutron activation analysis (TBNAA) and the determination of the mineral content of a bone of the appendicular skeleton (absorptiometric measurement of the radius, BMC). (U.S.)

  1. Complementary three-dimensional quantitative structure-activity relationship modeling of binding affinity and functional potency

    DEFF Research Database (Denmark)

    Tosco, Paolo; Ahring, Philip K; Dyhring, Tino

    2009-01-01

    Complementary 3D-QSAR modeling of binding affinity and functional potency is proposed as a tool to pinpoint the molecular features of the ligands, and the corresponding amino acids in the receptor, responsible for high affinity binding vs those driving agonist behavior and receptor activation. Th...

  2. 4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to inhibit hepatocellular carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Meili, E-mail: fumeilidrlinyi@tom.com [Department of Infectious Disease, Linyi People' s Hospital, Linyi 276000 (China); Wan, Fuqiang [Department of Head and Neck Surgery, Linyi Tumor Hospital, Linyi 276000 (China); Li, Zhengling [Department of Nursing, Tengzhou Central People' s Hospital, Tengzhou 277500 (China); Zhang, Fenghua [Department of Operating Room, Linyi People' s Hospital, Linyi 276000 (China)

    2016-03-04

    The aim of the present study is to investigate the potential anti-hepatocellular carcinoma (HCC) cell activity by 4SC-202, a novel class I HDAC inhibitor (HDACi). The associated signaling mechanisms were also analyzed. We showed that 4SC-202 treatment induced potent cytotoxic and proliferation–inhibitory activities against established HCC cell lines (HepG2, HepB3, SMMC-7721) and patient-derived primary HCC cells. Further, adding 4SC-202 in HCC cells activated mitochondrial apoptosis pathway, which was evidenced by mitochondrial permeability transition pore (mPTP) opening, cytochrome C cytosol release and caspase-3/-9 activation. Inhibition of this apoptosis pathway, by caspase-3/-9 inhibitors, mPTP blockers, or by shRNA-mediated knockdown of cyclophilin-D (Cyp-D, a key component of mPTP), significantly attenuated 4SC-202-induced HCC cell death and apoptosis. Reversely, over-expression of Cyp-D enhanced 4SC-202's sensitivity in HCC cells. Further studies showed that 4SC-202 induced apoptosis signal-regulating kinase 1 (ASK1) activation, causing it translocation to mitochondria and physical association with Cyp-D. This mitochondrial ASK1-Cyp-D complexation appeared required for mediating 4SC-202-induced apoptosis activation. ASK1 stable knockdown by targeted-shRNAs largely inhibited 4SC-202-induced mPTP opening, cytochrome C release, and following HCC cell apoptotic death. Together, we suggest that 4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to potently inhibit human HCC cells. - Highlights: • 4SC-202 exerts potent anti-proliferative and cytotoxic activity against established/primary HCC cells. • SC-202-induced anti-HCC cell activity relies on caspase-dependent apoptosis activation. • 4SC-202 activates Cyp-D-dependent mitochondrial apoptosis pathway in HCC cells. • 4SC-202 activates ASK1 in HCC cells, causing it translocation to mitochondria. • Mitochondrial ASK1-Cyp-D complexation mediates 4SC-202's activity in HCC cells.

  3. 4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to inhibit hepatocellular carcinoma cells

    International Nuclear Information System (INIS)

    Fu, Meili; Wan, Fuqiang; Li, Zhengling; Zhang, Fenghua

    2016-01-01

    The aim of the present study is to investigate the potential anti-hepatocellular carcinoma (HCC) cell activity by 4SC-202, a novel class I HDAC inhibitor (HDACi). The associated signaling mechanisms were also analyzed. We showed that 4SC-202 treatment induced potent cytotoxic and proliferation–inhibitory activities against established HCC cell lines (HepG2, HepB3, SMMC-7721) and patient-derived primary HCC cells. Further, adding 4SC-202 in HCC cells activated mitochondrial apoptosis pathway, which was evidenced by mitochondrial permeability transition pore (mPTP) opening, cytochrome C cytosol release and caspase-3/-9 activation. Inhibition of this apoptosis pathway, by caspase-3/-9 inhibitors, mPTP blockers, or by shRNA-mediated knockdown of cyclophilin-D (Cyp-D, a key component of mPTP), significantly attenuated 4SC-202-induced HCC cell death and apoptosis. Reversely, over-expression of Cyp-D enhanced 4SC-202's sensitivity in HCC cells. Further studies showed that 4SC-202 induced apoptosis signal-regulating kinase 1 (ASK1) activation, causing it translocation to mitochondria and physical association with Cyp-D. This mitochondrial ASK1-Cyp-D complexation appeared required for mediating 4SC-202-induced apoptosis activation. ASK1 stable knockdown by targeted-shRNAs largely inhibited 4SC-202-induced mPTP opening, cytochrome C release, and following HCC cell apoptotic death. Together, we suggest that 4SC-202 activates ASK1-dependent mitochondrial apoptosis pathway to potently inhibit human HCC cells. - Highlights: • 4SC-202 exerts potent anti-proliferative and cytotoxic activity against established/primary HCC cells. • SC-202-induced anti-HCC cell activity relies on caspase-dependent apoptosis activation. • 4SC-202 activates Cyp-D-dependent mitochondrial apoptosis pathway in HCC cells. • 4SC-202 activates ASK1 in HCC cells, causing it translocation to mitochondria. • Mitochondrial ASK1-Cyp-D complexation mediates 4SC-202's activity in HCC cells.

  4. Reactive Oxygen Species (ROS)-Activated ATM-Dependent Phosphorylation of Cytoplasmic Substrates Identified by Large-Scale Phosphoproteomics Screen*

    Science.gov (United States)

    Kozlov, Sergei V.; Waardenberg, Ashley J.; Engholm-Keller, Kasper; Arthur, Jonathan W.; Graham, Mark E.; Lavin, Martin

    2016-01-01

    Ataxia-telangiectasia, mutated (ATM) protein plays a central role in phosphorylating a network of proteins in response to DNA damage. These proteins function in signaling pathways designed to maintain the stability of the genome and minimize the risk of disease by controlling cell cycle checkpoints, initiating DNA repair, and regulating gene expression. ATM kinase can be activated by a variety of stimuli, including oxidative stress. Here, we confirmed activation of cytoplasmic ATM by autophosphorylation at multiple sites. Then we employed a global quantitative phosphoproteomics approach to identify cytoplasmic proteins altered in their phosphorylation state in control and ataxia-telangiectasia (A-T) cells in response to oxidative damage. We demonstrated that ATM was activated by oxidative damage in the cytoplasm as well as in the nucleus and identified a total of 9,833 phosphorylation sites, including 6,686 high-confidence sites mapping to 2,536 unique proteins. A total of 62 differentially phosphorylated peptides were identified; of these, 43 were phosphorylated in control but not in A-T cells, and 19 varied in their level of phosphorylation. Motif enrichment analysis of phosphopeptides revealed that consensus ATM serine glutamine sites were overrepresented. When considering phosphorylation events, only observed in control cells (not observed in A-T cells), with predicted ATM sites phosphoSerine/phosphoThreonine glutamine, we narrowed this list to 11 candidate ATM-dependent cytoplasmic proteins. Two of these 11 were previously described as ATM substrates (HMGA1 and UIMCI/RAP80), another five were identified in a whole cell extract phosphoproteomic screens, and the remaining four proteins had not been identified previously in DNA damage response screens. We validated the phosphorylation of three of these proteins (oxidative stress responsive 1 (OSR1), HDGF, and ccdc82) as ATM dependent after H2O2 exposure, and another protein (S100A11) demonstrated ATM-dependence

  5. Quantitative Analyses of Force-Induced Amyloid Formation in Candida albicans Als5p: Activation by Standard Laboratory Procedures.

    Directory of Open Access Journals (Sweden)

    Cho X J Chan

    Full Text Available Candida albicans adhesins have amyloid-forming sequences. In Als5p, these amyloid sequences cluster cell surface adhesins to create high avidity surface adhesion nanodomains. Such nanodomains form after force is applied to the cell surface by atomic force microscopy or laminar flow. Here we report centrifuging and resuspending S. cerevisiae cells expressing Als5p led to 1.7-fold increase in initial rate of adhesion to ligand coated beads. Furthermore, mechanical stress from vortex-mixing of Als5p cells or C. albicans cells also induced additional formation of amyloid nanodomains and consequent activation of adhesion. Vortex-mixing for 60 seconds increased the initial rate of adhesion 1.6-fold. The effects of vortex-mixing were replicated in heat-killed cells as well. Activation was accompanied by increases in thioflavin T cell surface fluorescence measured by flow cytometry or by confocal microscopy. There was no adhesion activation in cells expressing amyloid-impaired Als5pV326N or in cells incubated with inhibitory concentrations of anti-amyloid dyes. Together these results demonstrated the activation of cell surface amyloid nanodomains in yeast expressing Als adhesins, and further delineate the forces that can activate adhesion in vivo. Consequently there is quantitative support for the hypothesis that amyloid forming adhesins act as both force sensors and effectors.

  6. Quantitative analysis of the effect of climate change and human activities on runoff in the Liujiang River Basin

    Science.gov (United States)

    LI, X.

    2017-12-01

    Abstract: As human basic and strategic natural resources, Water resources have received an unprecedented challenge under the impacts of global climate change. Analyzing the variation characteristics of runoff and the effect of climate change and human activities on runoff could provide the basis for the reasonable utilization and management of water resources. Taking the Liujiang River Basin as the research object, the discharge data of hydrological station and meteorological data at 24 meteorological stations in the Guangxi Province as the basis, the variation characteristics of runoff and precipitation in the Liujiang River Basin was analyzed, and the quantitatively effect of climate change and human activities on runoff was proposed. The results showed that runoff and precipitation in the Liujiang River Basin had an increasing trend from 1964 to 2006. Using the method of accumulative anomaly and the orderly cluster method, the runoff series was divided into base period and change period. BP - ANN model and sensitivity coefficient method were used for quantifying the influences of climate change and human activities on runoff. We found that the most important factor which caused an increase trend of discharges in the Liujiang River Basin was precipitation. Human activities were also important factors which influenced the intra-annual distribution of runoff. Precipitation had a more sensitive influence to runoff variation than potential evaporation in the Liujiang River Basin. Key words: Liujiang River Basin, climate change, human activities, BP-ANN, sensitivity coefficient method

  7. Age-dependent regulation of ERF-VII transcription factor activity in Arabidopsis thaliana.

    Science.gov (United States)

    Giuntoli, Beatrice; Shukla, Vinay; Maggiorelli, Federica; Giorgi, Federico M; Lombardi, Lara; Perata, Pierdomenico; Licausi, Francesco

    2017-10-01

    The Group VII Ethylene Responsive Factors (ERFs-VII) RAP2.2 and RAP2.12 have been mainly characterized with regard to their contribution as activators of fermentation in plants. However, transcriptional changes measured in conditions that stabilize these transcription factors exceed the mere activation of this biochemical pathway, implying additional roles performed by the ERF-VIIs in other processes. We evaluated gene expression in transgenic Arabidopsis lines expressing a stabilized form of RAP2.12, or hampered in ERF-VII activity, and identified genes affected by this transcriptional regulator and its homologs, including some involved in oxidative stress response, which are not universally induced under anaerobic conditions. The contribution of the ERF-VIIs in regulating this set of genes in response to chemically induced or submergence-stimulated mitochondria malfunctioning was found to depend on the plant developmental stage. A similar age-dependent mechanism also restrained ERF-VII activity upon the core-hypoxic genes, independently of the N-end rule pathway, which is accounted for the control of the anaerobic response. To conclude, this study shed new light on a dual role of ERF-VII proteins under submergence: as positive regulators of the hypoxic response and as repressors of oxidative-stress related genes, depending on the developmental stage at which plants are challenged by stress conditions. © 2017 John Wiley & Sons Ltd.

  8. PEG-b-PCL polymeric nano-micelle inhibits vascular angiogenesis by activating p53-dependent apoptosis in zebrafish.

    Science.gov (United States)

    Zhou, Tian; Dong, Qinglei; Shen, Yang; Wu, Wei; Wu, Haide; Luo, Xianglin; Liao, Xiaoling; Wang, Guixue

    Micro/nanoparticles could cause adverse effects on cardiovascular system and increase the risk for cardiovascular disease-related events. Nanoparticles prepared from poly(ethylene glycol) (PEG)- b -poly( ε -caprolactone) (PCL), namely PEG- b -PCL, a widely studied biodegradable copolymer, are promising carriers for the drug delivery systems. However, it is unknown whether polymeric PEG- b -PCL nano-micelles give rise to potential complications of the cardiovascular system. Zebrafish were used as an in vivo model to evaluate the effects of PEG- b -PCL nano-micelle on cardiovascular development. The results showed that PEG- b -PCL nano-micelle caused embryo mortality as well as embryonic and larval malformations in a dose-dependent manner. To determine PEG- b -PCL nano-micelle effects on embryonic angiogenesis, a critical process in zebrafish cardiovascular development, growth of intersegmental vessels (ISVs) and caudal vessels (CVs) in flk1-GFP transgenic zebrafish embryos using fluorescent stereomicroscopy were examined. The expression of fetal liver kinase 1 (flk1), an angiogenic factor, by real-time quantitative polymerase chain reaction (qPCR) and in situ whole-mount hybridization were also analyzed. PEG- b -PCL nano-micelle decreased growth of ISVs and CVs, as well as reduced flk1 expression in a concentration-dependent manner. Parallel to the inhibitory effects on angiogenesis, PEG- b -PCL nano-micelle exposure upregulated p53 pro-apoptotic pathway and induced cellular apoptosis in angiogenic regions by qPCR and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) apoptosis assay. This study further showed that inhibiting p53 activity, either by pharmacological inhibitor or RNA interference, could abrogate the apoptosis and angiogenic defects caused by PEG- b -PCL nano-micelles, indicating that PEG- b -PCL nano-micelle inhibits angiogenesis by activating p53-mediated apoptosis. This study indicates that polymeric PEG- b -PCL nano-micelle could

  9. QUANTITATIVE STUDY ON THE INVOLVEMENT OF BRICOLAGE COMPANIES IN SOCIAL RESPONSIBILITY ACTIVITIES

    Directory of Open Access Journals (Sweden)

    Mihai-Cosmin FANARU

    2016-07-01

    Full Text Available The main purpose of this paper is to analyze the influence of social responsibility actions of the main bricolage companies doing business in Romania on their value, and mutually the impact these activities have on various social sectors. CSR (Corporate Social Responsibility is a concept related to the contribution that companies need to have to the development of modern society. Over time, this contribution has been theorized by many different schools of thought. "Responsible" initiatives of companies have been named by a variety of terms: corporate citizenship, corporate philanthropy, corporate societal marketing, community affairs, community development etc. Consequently, currently, to demonstrate that it is "socially responsible", a company must understand the principles of CSR that are internationally promoted and regularly report about the integration of these principles in its activities.

  10. Quantitative analysis and automation of CaF2 ore flotation via neutronic activation

    International Nuclear Information System (INIS)

    Reggiani, F.; Garagnani, A.; Lembo, L.; Muntoni, C.

    1992-01-01

    The aim of the project was to prove the operative feasibility of an 'one line analysis' based on nuclear activation using 14 MeV neutrons. This on line analysis method was to be used to automate control of the flotation process for ores containing mostly fluorspar. The thermoluminescence technique was also forecast as a subsidiary method in those points of the flotation cycle where less precision is acceptable. (author). 11 figs., 4 tabs

  11. Quantitative evaluation of blood elements by neutron activation analysis in mice immunized with Bothrops snake venoms

    International Nuclear Information System (INIS)

    Zamboni, C.B.; Metairon, S.; Suzuki, M.F.; Furtado, M.F.; Sant'Anna, O.A.; Tambourgi, D.V.

    2009-01-01

    Mice genetically selected for high antibody responsiveness (HIII) were immunized against different Bothrops species snake venoms from distinct region of Brazil. The Neutron Activation Analysis technique was used to evaluate the whole blood concentrations of elements of clinical relevance [Ca, Cl, K, Mg and Na] in order to establish a potential correlation between antibody response and blood constituents after Bothrops venom administration for clinical screening of envenomed patients. (author)

  12. Flavonoids as Vasorelaxant Agents: Synthesis, Biological Evaluation and Quantitative Structure Activities Relationship (QSAR Studies

    Directory of Open Access Journals (Sweden)

    Yongzhou Hu

    2011-09-01

    Full Text Available A series of 2-(2-diethylamino-ethoxychalcone and 6-prenyl(or its isomers-flavanones 10a,b and 11a–g were synthesized and evaluated for their vasorelaxant activities against rat aorta rings pretreated with 1 μM phenylephrine (PE. Several compounds showed potent vasorelaxant activities. Compound 10a (EC50 = 7.6 μM, Emax = 93.1%, the most potent one, would be a promising structural template for development of novel and more efficient vasodilators. Further, 2D-QSAR analysis of compounds 10a,b and 11c-e as well as thirty previously synthesized flavonoids 1-3 and 12-38 using Enhanced Replacement Method-Multiple Linear Regression (ERM-MLR was further performed based on an optimal set of molecular descriptors (H5m, SIC2, DISPe, Mor03u and L3m, leading to a reliable model with good predictive ability (Rtrain2 = 0.839, Qloo2 = 0.733 and Rtest2 = 0.804. The results provide good insights into the structure- activity relationships of the target compounds.

  13. Whole-body profile scanner for in vivo quantitative activity measurement

    International Nuclear Information System (INIS)

    Bergmann, H.

    1978-01-01

    A whole-body profile scanner has been developed by fitting parallel slit collimators to a shadow shield whole-body counter. Sensitivity, uniformity and resolution measurements were performed using a number of different counting conditions. It is shown that improved accuracy of activity measurements is obtained by using a wide window counting technique for low and medium energy gamma emitters (99m Tc, 131 I), whereas a photopeak window should be used for high energy gamma emitters (47 Ca). Due to the finite spatial resolution of the system a systematic error in evaluating regional activities from the counting rate profile occurs which is characterized by a spatial spillover factor. The spatial spillover factor is measured and is subsequently used to calculate the error on basis of a simple model. It is shown that only small errors are caused by spatial spillover when the length of a region is at least three times the full width half maximum of the point spread function. Applying the above mentioned simple rules it is concluded that profile scanning is a sensitive and accurate technique for activity measurements in vivo. Two examples of clinical applications (measurement of bone accretion rates of calcium and Tc-pyrophosphate, regional radioiodine retention in patients with thyroid carcinoma) and a review of the papers on profile scanning demonstrate the types of investigations in which profile scanning is superior to alternative techniques. (author)

  14. Hypoxia-ischemia or excitotoxin-induced tissue plasminogen activator- dependent gelatinase activation in mice neonate brain microvessels.

    Directory of Open Access Journals (Sweden)

    Priscilla L Omouendze

    Full Text Available Hypoxia-ischemia (HI and excitotoxicity are validated causes of neonatal brain injuries and tissue plasminogen activator (t-PA participates in the processes through proteolytic and receptor-mediated pathways. Brain microvascular endothelial cells from neonates in culture, contain and release more t-PA and gelatinases upon glutamate challenge than adult cells. We have studied t-PA to gelatinase (MMP-2 and MMP-9 activity links in HI and excitotoxicity lesion models in 5 day-old pups in wild type and in t-PA or its inhibitor (PAI-1 genes inactivated mice. Gelatinolytic activities were detected in SDS-PAGE zymograms and by in situ fluorescent DQ-gelatin microscopic zymographies. HI was achieved by unilateral carotid ligature followed by a 40 min hypoxia (8%O₂. Excitotoxic lesions were produced by intra parenchymal cortical (i.c. injections of 10 µg ibotenate (Ibo. Gel zymograms in WT cortex revealed progressive extinction of MMP-2 and MMP-9 activities near day 15 or day 8 respectively. MMP-2 expression was the same in all strains while MMP-9 activity was barely detectable in t-PA⁻/⁻ and enhanced in PAI-1⁻/⁻ mice. HI or Ibo produced activation of MMP-2 activities 6 hours post-insult, in cortices of WT mice but not in t-PA⁻/⁻ mice. In PAI-1⁻/⁻ mice, HI or vehicle i.c. injection increased MMP-2 and MMP-9 activities. In situ zymograms using DQ-gelatin revealed vessel associated gelatinolytic activity in lesioned areas in PAI-1⁻/⁻ and in WT mice. In WT brain slices incubated ex vivo, glutamate (200 µM induced DQ-gelatin activation in vessels. The effect was not detected in t-PA⁻/⁻ mice, but was restored by concomitant exposure to recombinant t-PA (20 µg/mL. In summary, neonatal brain lesion paradigms and ex vivo excitotoxic glutamate evoked t-PA-dependent gelatinases activation in vessels. Both MMP-2 and MMP-9 activities appeared t-PA-dependent. The data suggest that vascular directed protease inhibition may have

  15. JNK mitogen-activated protein kinase limits calcium-dependent chloride secretion across colonic epithelial cells.

    LENUS (Irish Health Repository)

    Donnellan, Fergal

    2010-01-01

    Neuroimmune agonists induce epithelial Cl(-) secretion through elevations in intracellular Ca2+ or cAMP. Previously, we demonstrated that epidermal growth factor receptor (EGFR) transactivation and subsequent ERK MAPK activation limits secretory responses to Ca2+-dependent, but not cAMP-dependent, agonists. Although JNK MAPKs are also expressed in epithelial cells, their role in regulating transport function is unknown. Here, we investigated the potential role for JNK in regulating Cl(-) secretion in T(84) colonic epithelial cells. Western blot analysis revealed that a prototypical Ca2+-dependent secretagogue, carbachol (CCh; 100 microM), induced phosphorylation of both the 46-kDa and 54-kDa isoforms of JNK. This effect was mimicked by thapsigargin (TG), which specifically elevates intracellular Ca2+, but not by forskolin (FSK; 10 microM), which elevates cAMP. CCh-induced JNK phosphorylation was attenuated by the EGFR inhibitor, tyrphostin-AG1478 (1 microM). Pretreatment of voltage-clamped T(84) cells with SP600125 (2 microM), a specific JNK inhibitor, potentiated secretory responses to both CCh and TG but not to FSK. The effects of SP600125 on CCh-induced secretion were not additive with those of the ERK inhibitor, PD98059. Finally, in apically permeabilized T(84) cell monolayers, SP600125 potentiated CCh-induced K+ conductances but not Na+\\/K+ATPase activity. These data demonstrate a novel role for JNK MAPK in regulating Ca2+ but not cAMP-dependent epithelial Cl(-) secretion. JNK activation is mediated by EGFR transactivation and exerts its antisecretory effects through inhibition of basolateral K+ channels. These data further our understanding of mechanisms regulating epithelial secretion and underscore the potential for exploitation of MAPK-dependent signaling in treatment of intestinal transport disorders.

  16. Quantitative cell signalling analysis reveals down-regulation of MAPK pathway activation in colorectal cancer.

    LENUS (Irish Health Repository)

    Gulmann, Christian

    2009-08-01

    Mitogen-activated protein kinases (MAPK) are considered to play significant roles in colonic carcinogenesis and kinase inhibitor therapy has been proposed as a potential tool in the treatment of this disease. Reverse-phase microarray assays using phospho-specific antibodies can directly measure levels of phosphorylated protein isoforms. In the current study, samples from 35 cases of untreated colorectal cancer colectomies were laser capture-microdissected to isolate epithelium and stroma from cancer as well as normal (i.e. uninvolved) mucosa. Lysates generated from these four tissue types were spotted onto reverse-phase protein microarrays and probed with a panel of antibodies to ERK, p-ERK, p38, p-p38, p-JNK, MEK and p-MEK. Whereas total protein levels were unchanged, or slightly elevated (p38, p = 0.0025) in cancers, activated isoforms, including p-ERK, p-p38 and p-JNK, were decreased two- to four-fold in cancers compared with uninvolved mucosa (p < 0.0023 in all cases except for p-JNK in epithelium, where decrement was non-significant). This was backed up by western blotting. Dukes\\' stage B and C cancers displayed lower p-ERK and p-p38 expression than Dukes\\' stage A cancers, although this was not statistically significant. It is concluded that MAPK activity may be down-regulated in colorectal cancer and that further exploration of inhibitory therapy in this system should be carefully evaluated if this finding is confirmed in larger series.

  17. Subnanomole detection and quantitation of high specific activity 32P-nucleotides

    International Nuclear Information System (INIS)

    Coniglio, C.; Pappas, G.; Gill, W.J.; Kashdan, M.; Maniscalco, M.

    1991-01-01

    Microbore liquid chromatography utilizes conventional HPLC and ultraviolet detection principles to determine subnanomole mass quantities of biologically significant molecules. This system takes advantage of specifically designed microflow equipment to analyze ultraviolet absorbing species at the picomole range. 32P-labeled nucleotides are examples of compounds routinely used at picomole quantities that are extremely difficult to accurately quantify using standard mass measurement techniques. The procedure described in this paper has the capability of measuring nucleotides down to 10 pmol using commercially available microbore ultraviolet detection equipment. The technique can be used to accurately measure the specific activity of as little as 10 microCi of an aqueous 32P-nucleotide solution

  18. Quantitative radiological characterization of waste. Integration of gamma spectrometry and passive/active neutron assay

    Energy Technology Data Exchange (ETDEWEB)

    Simone, Gianluca; Mauro, Egidio; Gagliardi, Filippo; Gorello, Edoardo [Nucleco S.p.A., Rome (Italy)

    2016-06-15

    The radiological characterization of drums through Non-Destructive Assay (NDA) techniques commonly relies on gamma spectrometry. This paper introduces the procedure developed in Nucleco for the NDA radiological characterization of drums when the presence of Special Nuclear Material (SNM) is expected/observed. The procedure is based on the integration of a gamma spectrometry in SGS mode (Segmented Gamma Scanner) and a passive/active neutron assay. The application of this procedure is discussed on a real case of drums. The extension of the integration procedure to other gamma spectrometry systems is also discussed.

  19. Antifeedant effect of polygodial and drimenol derivatives against Spodoptera frugiperda and Epilachna paenulata and quantitative structure-activity analysis.

    Science.gov (United States)

    Montenegro, Iván J; Del Corral, Soledad; Diaz Napal, Georgina N; Carpinella, María C; Mellado, Marco; Madrid, Alejandro M; Villena, Joan; Palacios, Sara M; Cuellar, Mauricio A

    2018-01-08

    The antifeedant activity of 18 sesquiterpenoids of the drimane family (polygodial, drimenol and derivatives) was investigated. Polygodial, drimanic and nordrimanic derivatives were found to exert antifeedant effects against two insect species, Spodoptera frugiperda and Epilachna paenulata, which are pests of agronomic interest, indicating that they have potential as biopesticide agents. Among the 18 compounds tested, the epoxynordrimane compound (11) and isonordrimenone (4) showed the highest activity [50% effective concentration (EC 50 ) = 23.28 and 25.63 nmol cm - 2 , respectively, against S. frugiperda, and 50.50 and 59.00 nmol/cm 2 , respectively, against E. paenulata]. The results suggest that drimanic compounds have potential as new agents against S. frugiperda and E. paenulata. A quantitative structure-activity relationship (QSAR) analysis of the whole series, supported by electronic studies, suggested that drimanic compounds have structural features necessary for increasing antifeedant activity, namely a C-9 carbonyl group and an epoxide at C-8 and C-9. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  20. QUANTITATIVE STRUCTURE-ACTIVITY RELATIONSHIP ANALYSIS (QSAR OF VINCADIFFORMINE ANALOGUES AS THE ANTIPLASMODIAL COMPOUNDS OF THE CHLOROQUINOSENSIBLE STRAIN

    Directory of Open Access Journals (Sweden)

    Iqmal Tahir

    2010-06-01

    Full Text Available Quantitative Structure-Activity Relationship (QSAR analysis of vincadifformine analogs as an antimalarial drug has been conducted using atomic net charges (q, moment dipole (, LUMO (Lowest Unoccupied Molecular Orbital and HOMO (Highest Occupied Molecular Orbital energies, molecular mass (m as well as surface area (A as the predictors to their activity. Data of predictors are obtained from computational chemistry method using semi-empirical molecular orbital AM1 calculation. Antimalarial activities were taken as the activity of the drugs against chloroquine-sensitive Plasmodium falciparum (Nigerian Cell strain and were presented as the value of ln(1/IC50 where IC50 is an effective concentration inhibiting 50% of the parasite growth. The best QSAR model has been determined by multiple linier regression analysis giving QSAR equation: Log (1/IC50 = 9.602.qC1 -17.012.qC2 +6.084.qC3 -19.758.qC5 -6.517.qC6 +2.746.qC7 -6.795.qN +6.59.qC8 -0.190. -0.974.ELUMO +0.515.EHOMO -0.274. +0.029.A -1.673 (n = 16; r = 0.995; SD = 0.099; F = 2.682   Keywords: QSAR analysis, antimalaria, vincadifformine.

  1. Designing quantitative structure activity relationships to predict specific toxic endpoints for polybrominated diphenyl ethers in mammalian cells.

    Science.gov (United States)

    Rawat, S; Bruce, E D

    2014-01-01

    Polybrominated diphenyl ethers (PBDEs) are known as effective flame retardants and have vast industrial application in products like plastics, building materials and textiles. They are found to be structurally similar to thyroid hormones that are responsible for regulating metabolism in the body. Structural similarity with the hormones poses a threat to human health because, once in the system, PBDEs have the potential to affect thyroid hormone transport and metabolism. This study was aimed at designing quantitative structure-activity relationship (QSAR) models for predicting toxic endpoints, namely cell viability and apoptosis, elicited by PBDEs in mammalian cells. Cell viability was evaluated quantitatively using a general cytotoxicity bioassay using Janus Green dye and apoptosis was evaluated using a caspase assay. This study has thus modelled the overall cytotoxic influence of PBDEs at an early and a late endpoint by the Genetic Function Approximation method. This research was a twofold process including running in vitro bioassays to collect data on the toxic endpoints and modeling the evaluated endpoints using QSARs. Cell viability and apoptosis responses for Hep G2 cells exposed to PBDEs were successfully modelled with an r(2) of 0.97 and 0.94, respectively.

  2. Regulation of the ligand-dependent activation of the epidermal growth factor receptor by calmodulin

    DEFF Research Database (Denmark)

    Li, Hongbing; Panina, Svetlana; Kaur, Amandeep

    2012-01-01

    Calmodulin (CaM) is the major component of calcium signaling pathways mediating the action of various effectors. Transient increases in the intracellular calcium level triggered by a variety of stimuli lead to the formation of Ca2+/CaM complexes, which interact with and activate target proteins....... In the present study the role of Ca2+/CaM in the regulation of the ligand-dependent activation of the epidermal growth factor receptor (EGFR) has been examined in living cells. We show that addition of different cell permeable CaM antagonists to cultured cells or loading cells with a Ca2+ chelator inhibited...

  3. Antiretroviral treatment is associated with increased attentional load-dependent brain activation in HIV patients.

    Science.gov (United States)

    Chang, L; Yakupov, R; Nakama, H; Stokes, B; Ernst, T

    2008-06-01

    The purpose of this paper was to determine whether antiretroviral medications, especially the nucleoside analogue reverse transcriptase inhibitors, lead to altered brain activation due to their potential neurotoxic effects in patients with human immunodeficiency virus (HIV) infection. Forty-two right-handed men were enrolled in three groups: seronegative controls (SN, n = 18), HIV subjects treated with antiretroviral medications (HIV+ARV, n = 12), or not treated with antiretroviral medications (HIV+NARV, n = 12). Each subject performed a set of visual attention tasks with increasing difficulty or load (tracking two, three or four balls) during functional magnetic resonance imaging. HIV subjects, both groups combined, showed greater load-dependent increases in brain activation in the right frontal regions compared to SN (p-corrected = 0.006). HIV+ARV additionally showed greater load-dependent increases in activation compared to SN in bilateral superior frontal regions (p-corrected = 0.032) and a lower percent accuracy on the performance of the most difficult task (tracking four balls). Region of interest analyses further demonstrated that SN showed load-dependent decreases (with repeated trials despite increasing difficulty), while HIV subjects showed load-dependent increases in activation with the more difficult tasks, especially those on ARVs. These findings suggest that chronic ARV treatments may lead to greater requirement of the attentional network reserve and hence less efficient usage of the network and less practice effects in these HIV patients. As the brain has a limited reserve capacity, exhausting the reserve capacity in HIV+ARV would lead to declined performance with more difficult tasks that require more attention.

  4. Bilateral versus ipsilesional cortico-subcortical activity patterns in stroke show hemispheric dependence.

    Science.gov (United States)

    Vidal, Ana C; Banca, Paula; Pascoal, Augusto G; Cordeiro, Gustavo; Sargento-Freitas, João; Gouveia, Ana; Castelo-Branco, Miguel

    2018-01-01

    Background Understanding of interhemispheric interactions in stroke patients during motor control is an important clinical neuroscience quest that may provide important clues for neurorehabilitation. In stroke patients bilateral overactivation in both hemispheres has been interpreted as a poor prognostic indicator of functional recovery. In contrast, ipsilesional patterns have been linked with better motor outcomes. Aim We investigated the pathophysiology of hemispheric interactions during limb movement without and with contralateral restraint, to mimic the effects of constraint-induced movement therapy. We used neuroimaging to probe brain activity with such a movement-dependent interhemispheric modulation paradigm. Methods We used a functional magnetic resonance imaging block design during which the plegic/paretic upper limb was recruited/mobilized to perform unilateral arm elevation, as a function of presence versus absence of contralateral limb restriction (n = 20, with balanced left/right lesion sites). Results Analysis of 10 right hemispheric stroke participants yielded bilateral sensorimotor cortex activation in all movement phases in contrast with the unilateral dominance seen in the 10 left hemispheric stroke participants. Superimposition of contralateral restriction led to a prominent shift from activation to deactivation response patterns, in particular in cortical and basal ganglia motor areas in right hemispheric stroke. Left hemispheric stroke was, in general, characterized by reduced activation patterns, even in the absence of restriction, which induced additional cortical silencing. Conclusion The observed hemispheric-dependent activation/deactivation shifts is novel and these pathophysiological observations suggest short-term neuroplasticity that may be useful for hemisphere-tailored neurorehabilitation.

  5. Shape-dependent bactericidal activity of copper oxide nanoparticle mediated by DNA and membrane damage

    International Nuclear Information System (INIS)

    Laha, Dipranjan; Pramanik, Arindam; Laskar, Aparna; Jana, Madhurya; Pramanik, Panchanan; Karmakar, Parimal

    2014-01-01

    Highlights: • Spherical and sheet shaped copper oxide nanoparticles were synthesized. • Physical characterizations of these nanoparticles were done by TEM, DLS, XRD, FTIR. • They showed shape dependent antibacterial activity on different bacterial strain. • They induced both membrane damage and ROS mediated DNA damage in bacteria. - Abstract: In this work, we synthesized spherical and sheet shaped copper oxide nanoparticles and their physical characterizations were done by the X-ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. The antibacterial activity of these nanoparticles was determined on both gram positive and gram negative bacterial. Spherical shaped copper oxide nanoparticles showed more antibacterial property on gram positive bacteria where as sheet shaped copper oxide nanoparticles are more active on gram negative bacteria. We also demonstrated that copper oxide nanoparticles produced reactive oxygen species in both gram negative and gram positive bacteria. Furthermore, they induced membrane damage as determined by atomic force microscopy and scanning electron microscopy. Thus production of and membrane damage are major mechanisms of the bactericidal activity of these copper oxide nanoparticles. Finally it was concluded that antibacterial activity of nanoparticles depend on physicochemical properties of copper oxide nanoparticles and bacterial strain

  6. Shape-dependent bactericidal activity of copper oxide nanoparticle mediated by DNA and membrane damage

    Energy Technology Data Exchange (ETDEWEB)

    Laha, Dipranjan; Pramanik, Arindam [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India); Laskar, Aparna [CSIR-Indian Institute of Chemical Biology, Kolkata 700032 (India); Jana, Madhurya [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India); Pramanik, Panchanan [Department of Chemistry, Indian Institute of Technology, Kharagpur 721302 (India); Karmakar, Parimal, E-mail: pkarmakar_28@yahoo.co.in [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India)

    2014-11-15

    Highlights: • Spherical and sheet shaped copper oxide nanoparticles were synthesized. • Physical characterizations of these nanoparticles were done by TEM, DLS, XRD, FTIR. • They showed shape dependent antibacterial activity on different bacterial strain. • They induced both membrane damage and ROS mediated DNA damage in bacteria. - Abstract: In this work, we synthesized spherical and sheet shaped copper oxide nanoparticles and their physical characterizations were done by the X-ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. The antibacterial activity of these nanoparticles was determined on both gram positive and gram negative bacterial. Spherical shaped copper oxide nanoparticles showed more antibacterial property on gram positive bacteria where as sheet shaped copper oxide nanoparticles are more active on gram negative bacteria. We also demonstrated that copper oxide nanoparticles produced reactive oxygen species in both gram negative and gram positive bacteria. Furthermore, they induced membrane damage as determined by atomic force microscopy and scanning electron microscopy. Thus production of and membrane damage are major mechanisms of the bactericidal activity of these copper oxide nanoparticles. Finally it was concluded that antibacterial activity of nanoparticles depend on physicochemical properties of copper oxide nanoparticles and bacterial strain.

  7. Molecular mechanism of bacterial Hsp90 pH-dependent ATPase activity.

    Science.gov (United States)

    Jin, Yi; Hoxie, Reyal S; Street, Timothy O

    2017-06-01

    Hsp90 is a dimeric molecular chaperone that undergoes an essential and highly regulated open-to-closed-to-open conformational cycle upon ATP binding and hydrolysis. Although it has been established that a large energy barrier to closure is responsible for Hsp90's low ATP hydrolysis rate, the specific molecular contacts that create this energy barrier are not known. Here we discover that bacterial Hsp90 (HtpG) has a pH-dependent ATPase activity that is unique among other Hsp90 homologs. The underlying mechanism is a conformation-specific electrostatic interaction between a single histidine, H255, and bound ATP. H255 stabilizes ATP only while HtpG adopts a catalytically inactive open configuration, resulting in a striking anti-correlation between nucleotide binding affinity and chaperone activity over a wide range of pH. Linkage analysis reveals that the H255-ATP salt bridge contributes 1.5 kcal/mol to the energy barrier of closure. This energetic contribution is structurally asymmetric, whereby only one H255-ATP salt-bridge per dimer of HtpG controls ATPase activation. We find that a similar electrostatic mechanism regulates the ATPase of the endoplasmic reticulum Hsp90, and that pH-dependent activity can be engineered into eukaryotic cytosolic Hsp90. These results reveal site-specific energetic information about an evolutionarily conserved conformational landscape that controls Hsp90 ATPase activity. © 2017 The Protein Society.

  8. Calcium/calmodulin-dependent protein kinase II activity regulates the proliferative potential of growth plate chondrocytes.

    Science.gov (United States)

    Li, Yuwei; Ahrens, Molly J; Wu, Amy; Liu, Jennifer; Dudley, Andrew T

    2011-01-01

    For tissues that develop throughout embryogenesis and into postnatal life, the generation of differentiated cells to promote tissue growth is at odds with the requirement to maintain the stem cell/progenitor cell population to preserve future growth potential. In the growth plate cartilage, this balance is achieved in part by establishing a proliferative phase that amplifies the number of progenitor cells prior to terminal differentiation into hypertrophic chondrocytes. Here, we show that endogenous calcium/calmodulin-dependent protein kinase II (CamkII, also known as Camk2) activity is upregulated prior to hypertrophy and that loss of CamkII function substantially blocks the transition from proliferation to hypertrophy. Wnt signaling and Pthrp-induced phosphatase activity negatively regulate CamkII activity. Release of this repression results in activation of multiple effector pathways, including Runx2- and β-catenin-dependent pathways. We present an integrated model for the regulation of proliferation potential by CamkII activity that has important implications for studies of growth control and adult progenitor/stem cell populations.

  9. Intracellular zinc activates KCNQ channels by reducing their dependence on phosphatidylinositol 4,5-bisphosphate.

    Science.gov (United States)

    Gao, Haixia; Boillat, Aurélien; Huang, Dongyang; Liang, Ce; Peers, Chris; Gamper, Nikita

    2017-08-01

    M-type (Kv7, KCNQ) potassium channels are proteins that control the excitability of neurons and muscle cells. Many physiological and pathological mechanisms of excitation operate via the suppression of M channel activity or expression. Conversely, pharmacological augmentation of M channel activity is a recognized strategy for the treatment of hyperexcitability disorders such as pain and epilepsy. However, physiological mechanisms resulting in M channel potentiation are rare. Here we report that intracellular free zinc directly and reversibly augments the activity of recombinant and native M channels. This effect is mechanistically distinct from the known redox-dependent KCNQ channel potentiation. Interestingly, the effect of zinc cannot be attributed to a single histidine- or cysteine-containing zinc-binding site within KCNQ channels. Instead, zinc dramatically reduces KCNQ channel dependence on its obligatory physiological activator, phosphatidylinositol 4,5-bisphosphate (PIP 2 ). We hypothesize that zinc facilitates interactions of the lipid-facing interface of a KCNQ protein with the inner leaflet of the plasma membrane in a way similar to that promoted by PIP 2 Because zinc is increasingly recognized as a ubiquitous intracellular second messenger, this discovery might represent a hitherto unknown native pathway of M channel modulation and provide a fresh strategy for the design of M channel activators for therapeutic purposes.

  10. The Evaluation of Bioelectrical Activity of Pelvic Floor Muscles Depending on Probe Location: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Tomasz Halski

    2013-01-01

    Full Text Available Objectives. The main objective was to determine how the depth of probe placement affects functional and resting bioelectrical activity of the PFM and whether the recorded signal might be dependent on the direction in which the probe is rotated. Participants. The study comprised of healthy, nulliparous women between the ages of 21 and 25. Outcome Measures. Bioelectric activity of the PFM was recorded from four locations of the vagina by surface EMG and vaginal probe. Results. There were no statistically significant differences between the results during functional sEMG activity. During resting sEMG activity, the highest bioelectrical activity of the PFM was observed in the L1 and the lowest in the L4 and a statistically significant difference between the highest and the lowest results of resting sEMG activity was observed (P=0.0043. Conclusion. Different electrodes placement during functional contraction of PFM does not affect the obtained results in sEMG evaluation. In order to diagnose the highest resting activity of PFM the recording plates should be placed toward the anterior vaginal wall and distally from the introitus. However, all of the PFM have similar bioelectrical activity and it seems that these muscles could be treated as a single muscle.

  11. DNA-dependent protein kinase participates in the radiation activation of NF-kB

    International Nuclear Information System (INIS)

    Rosenzweig, Kenneth E.; Youmell, Matthew B.; Price, Brendan D.

    1997-01-01

    The NF-kB transcription factor is maintained in an inactive state by binding to the lkBa inhibitory protein. Activation requires phosphorylation and degradation of lkBa, releasing active NF-kB. NF-kB can be activated by cytokines, antigens, free radicals and X-ray irradiation. The protein kinase responsible for phosphorylation of lkBa in vivo has not been fully characterized. Here, we have examined the role of the DNA-dependent protein kinases (DNA-PK) in the radiation-activation of NF-kB. Wortmannin is an inhibitor of DNA-PK and related kinases. Exposure of SW480 cells to wortmannin inhibited the radioactivation of NF-kB DNA-binding. Analysis of lkBa levels by western blotting indicated that wortmannin blocked the radiation induced degradation of lkBa. In in vitro experiments, purified DNA-PK was able to efficiently phosphorylate lkBa, and this phosphorylation was inhibited by wortmannin. In contrast, the induction of NF-kB activity by TNFa was unaffected by wortmannin. The results suggest that DNA-PK may phosphorylate lkBa following irradiation, leading to degradation of lkBa and the release of active NF-kB. The inability of wortmannin to block TNFa activation of NF-kB indicates there may be more than one pathway for the activation of NF-kB

  12. Dependence of 210Po activity on organic matter in the reverine environs of coastal Kerala

    International Nuclear Information System (INIS)

    Narayana, Y.; Venunathan, N.

    2011-01-01

    This paper deals with the distribution of 210 Po in the river bank soil samples of three major rivers namely Bharathapuzha, Periyar and Kallada river of Kerala. The dependence of 210 Po activity on organic matter content in the samples was also studied. The soil samples were collected and analyzed for 210 Po radionuclide using standard radiochemical analytical method. Activity of 210 Po increases with increase in organic matter content in samples. Along the Bharathapuzha river bank the 210 Po activity ranges from 2.96 to 12.48 Bq kg -1 with mean 5.62 Bq kg -1 . The organic matter percentage in the samples ranges from 0.4 to 2.8 and a good correlation with correlation coefficient 0.9 was found between activity and organic matter percentage. In the Periyar river environs 210 Po activity ranges from 3.47 to 13.39 Bq kg -1 with mean value 9.27 Bq kg -1 . Organic matter percentage in these samples ranges from 1.20 to 4.10 and the correlation coefficient between 210 Po activity and organic matter percentage was found to be 0.8 In the Kallada river bank soil samples 210 Po activity ranges from 4.46 to 6.45 Bq kg -1 . The organic matter percentage ranges from 1.4 to 3. The correlation coefficient between 210 Po activity and organic matter percentage in the samples was found to be 0.9. (author)

  13. Activation-Dependent Rapid Postsynaptic Clustering of Glycine Receptors in Mature Spinal Cord Neurons

    Science.gov (United States)

    Eto, Kei; Murakoshi, Hideji; Watanabe, Miho; Hirata, Hiromi; Moorhouse, Andrew J.; Ishibashi, Hitoshi

    2017-01-01

    Abstract Inhibitory synapses are established during development but continue to be generated and modulated in strength in the mature nervous system. In the spinal cord and brainstem, presynaptically released inhibitory neurotransmitter dominantly switches from GABA to glycine during normal development in vivo. While presynaptic mechanisms of the shift of inhibitory neurotransmission are well investigated, the contribution of postsynaptic neurotransmitter receptors to this shift is not fully elucidated. Synaptic clustering of glycine receptors (GlyRs) is regulated by activation-dependent depolarization in early development. However, GlyR activation induces hyperpolarization after the first postnatal week, and little is known whether and how presynaptically released glycine regulates postsynaptic receptors in a depolarization-independent manner in mature developmental stage. Here we developed spinal cord neuronal culture of rodents using chronic strychnine application to investigate whether initial activation of GlyRs in mature stage could change postsynaptic localization of GlyRs. Immunocytochemical analyses demonstrate that chronic blockade of GlyR activation until mature developmental stage resulted in smaller clusters of postsynaptic GlyRs that could be enlarged upon receptor activation for 1 h in the mature stage. Furthermore, live cell-imaging techniques show that GlyR activation decreases its lateral diffusion at synapses, and this phenomenon is dependent on PKC, but neither Ca2+ nor CaMKII activity. These results suggest that the GlyR activation can regulate receptor diffusion and cluster size at inhibitory synapses in mature stage, providing not only new insights into the postsynaptic mechanism of shifting inhibitory neurotransmission but also the inhibitory synaptic plasticity in mature nervous system. PMID:28197549

  14. Free radical activity during development of insulin-dependent diabetes mellitus in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Pitkaenen, O.M.; Akerblom, H.K.; Sariola, H.; Andersson, S.M. (Univ. of Helsinki (Finland)); Martin, J.M. (Hospital for Sick Children, Toronto, Ontario (Canada)); Hallman, M. (Univ. of California, Irvine (United States))

    1991-01-01

    Free radical-induced lipid peroxidation was quantified by measuring expired pentane from diabetic prone BB Wistar rats of 45-90 d of age. Insulin-dependent diabetes mellitus was manifest at the age of 71 {plus minus} 8 d. Expired pentane increased from 2.1 {plus minus} 0.7 to 5.0 {plus minus}3.0 pmol/100g/min (p <0.01) at manifestation of the disease and remained high throughout the test period. In healthy age-matched control rats it persisted low. In rats made diabetic with streptozotocin, expired pentane remained low. The changes in expired pentane suggest that the development of endogenous insulin-dependent diabetes mellitus in BB rats is associated with increased free radical activity. This is not due to hyperglycemia or ketosis per se, and reflects a fundamental difference in the free radical activity between the spontaneously diabetic BB rats and the disease produced by streptozotocin. Development of spontaneous insulin-dependent diabetes in BB rats is associated with increased free radical activity that persists after the manifestation of the disease.

  15. Bacteria and viruses modulate FcεRI-dependent mast cell activity 

    Directory of Open Access Journals (Sweden)

    Aleksandra Słodka

    2013-03-01

    Full Text Available Undoubtedly, mast cells play a central role in allergic processes. Specific allergen cross-linking of IgE bound to the high affinity receptors (FcεRI on the mast cell surface leads to the release of preformed mediators and newly synthesized mediators, i.e. metabolites of arachidonic acid and cytokines. More and more data indicate that bacteria and viruses can influence FcεRI-dependent mast cell activation. Some bacterial and viral components can reduce the surface expression of FcεRI. There are also findings that ligation of Toll-like receptors (TLRs by bacterial or viral antigens can affect IgE-dependent mast cell degranulation and preformed mediator release as well as eicosanoid production. The synergistic interaction of TLR ligands and allergen can also modify cytokine synthesis by mast cells stimulated via FcεRI. Moreover, data suggest that specific IgE for bacterial or viral antigens can influence mast cell activity. What is more, some bacterial and viral components or some endogenous proteins produced during viral infection can act as superantigens by interacting with the VH3 domain of IgE. All these observations indicate that bacterial and viral infections modify the course of allergic diseases by affecting FcεRI-dependent mast cell activation

  16. Quantitative ligand and receptor binding studies reveal the mechanism of interleukin-36 (IL-36) pathway activation.

    Science.gov (United States)

    Zhou, Li; Todorovic, Viktor; Kakavas, Steve; Sielaff, Bernhard; Medina, Limary; Wang, Leyu; Sadhukhan, Ramkrishna; Stockmann, Henning; Richardson, Paul L; DiGiammarino, Enrico; Sun, Chaohong; Scott, Victoria

    2018-01-12

    IL-36 cytokines signal through the IL-36 receptor (IL-36R) and a shared subunit, IL-1RAcP (IL-1 receptor accessory protein). The activation mechanism for the IL-36 pathway is proposed to be similar to that of IL-1 in that an IL-36R agonist (IL-36α, IL-36β, or IL-36γ) forms a binary complex with IL-36R, which then recruits IL-1RAcP. Recent studies have shown that IL-36R interacts with IL-1RAcP even in the absence of an agonist. To elucidate the IL-36 activation mechanism, we considered all possible binding events for IL-36 ligands/receptors and examined these events in direct binding assays. Our results indicated that the agonists bind the IL-36R extracellular domain with micromolar affinity but do not detectably bind IL-1RAcP. Using surface plasmon resonance (SPR), we found that IL-1RAcP also does not bind IL-36R when no agonist is present. In the presence of IL-36α, however, IL-1RAcP bound IL-36R strongly. These results suggested that the main pathway to the IL-36R·IL-36α·IL-1RAcP ternary complex is through the IL-36R·IL-36α binary complex, which recruits IL-1RAcP. We could not measure the binding affinity of IL-36R to IL-1RAcP directly, so we engineered a fragment crystallizable-linked construct to induce IL-36R·IL-1RAcP heterodimerization and predicted the binding affinity during a complete thermodynamic cycle to be 74 μm The SPR analysis also indicated that the IL-36R antagonist IL-36Ra binds IL-36R with higher affinity and a much slower off rate than the IL-36R agonists, shedding light on IL-36 pathway inhibition. Our results reveal the landscape of IL-36 ligand and receptor interactions, improving our understanding of IL-36 pathway activation and inhibition. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Tragedy into policy: a quantitative study of nurses' attitudes toward patient advocacy activities.

    Science.gov (United States)

    Black, Lisa M

    2011-06-01

    In 2007 and 2008, 115 patients were found to be either certainly or presumptively infected with the hepatitis C virus through the reuse of contaminated medication vials at two southern Nevada endoscopy clinics. A subsequent joint investigation by federal and state agencies found multiple breaches of infection control protocols. There was also strong anecdotal evidence that among clinic staff, unsafe patient care conditions often went unreported because of a general fear of retaliation. At the request of the Nevada legislature's Legislative Committee on Health Care, a study was conducted to examine Nevada RNs' experiences with workplace attitudes toward patient advocacy activities. This article presents the study findings and reviews how one public health tragedy led to the creation of effective health care policy. A study questionnaire was developed and tested for reliability and validity. Questionnaires were then sent to an initial sample of 1,725 Nevada RNs, representing 10% of all RNs in the Nevada State Board of Nursing database with active licenses and current Nevada addresses. The response rate was modest at 33% (564 respondents). Of those who responded, 34% indicated that they'd been aware of a patient care condition that could have caused harm to a patient, yet hadn't reported it. The most common reasons given for nonreporting included fears of workplace retaliation (44%) and a belief that nothing would come of reports that were made (38%). The study findings underscore the need for a shift in organizational culture toward one that encourages clear and open communication when patient safety may be in jeopardy. These findings were ultimately used to support the passage of whistleblower protection legislation in Nevada. Las Vegas hepatitis C outbreak, patient advocacy, whistleblower.

  18. Sex-specific genetic effects in physical activity: results from a quantitative genetic analysis.

    Science.gov (United States)

    Diego, Vincent P; de Chaves, Raquel Nichele; Blangero, John; de Souza, Michele Caroline; Santos, Daniel; Gomes, Thayse Natacha; dos Santos, Fernanda Karina; Garganta, Rui; Katzmarzyk, Peter T; Maia, José A R

    2015-08-01

    The objective of this study is to present a model to estimate sex-specific genetic effects on physical activity (PA) levels and sedentary behaviour (SB) using three generation families. The sample consisted of 100 families covering three generations from Portugal. PA and SB were assessed via the International Physical Activity Questionnaire short form (IPAQ-SF). Sex-specific effects were assessed by genotype-by-sex interaction (GSI) models and sex-specific heritabilities. GSI effects and heterogeneity were tested in the residual environmental variance. SPSS 17 and SOLAR v. 4.1 were used in all computations. The genetic component for PA and SB domains varied from low to moderate (11% to 46%), when analyzing both genders combined. We found GSI effects for vigorous PA (p = 0.02) and time spent watching television (WT) (p < 0.001) that showed significantly higher additive genetic variance estimates in males. The heterogeneity in the residual environmental variance was significant for moderate PA (p = 0.02), vigorous PA (p = 0.006) and total PA (p = 0.001). Sex-specific heritability estimates were significantly higher in males only for WT, with a male-to-female difference in heritability of 42.5 (95% confidence interval: 6.4, 70.4). Low to moderate genetic effects on PA and SB traits were found. Results from the GSI model show that there are sex-specific effects in two phenotypes, VPA and WT with a stronger genetic influence in males.

  19. Structure-dependent binding and activation of perfluorinated compounds on human peroxisome proliferator-activated receptor γ

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lianying [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, 18 Shuangqing Road, Beijing 100085 (China); College of Life Science, Dezhou University, Dezhou 253023 (China); Ren, Xiao-Min; Wan, Bin [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, 18 Shuangqing Road, Beijing 100085 (China); Guo, Liang-Hong, E-mail: LHGuo@rcees.ac.cn [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, 18 Shuangqing Road, Beijing 100085 (China)

    2014-09-15

    Perfluorinated compounds (PFCs) have been shown to disrupt lipid metabolism and even induce cancer in rodents through activation of peroxisome proliferator-activated receptors (PPARs). Lines of evidence showed that PPARα was activated by PFCs. However, the information on the binding interactions between PPARγ and PFCs and subsequent alteration of PPARγ activity is still limited and sometimes inconsistent. In the present study, in vitro binding of 16 PFCs to human PPARγ ligand binding domain (hPPARγ-LBD) and their activity on the receptor in cells were investigated. The results showed that the binding affinity was strongly dependent on their carbon number and functional group. For the eleven perfluorinated carboxylic acids (PFCAs), the binding affinity increased with their carbon number from 4 to 11, and then decreased slightly. The binding affinity of the three perfluorinated sulfonic acids (PFSAs) was stronger than their PFCA counterparts. No binding was detected for the two fluorotelomer alcohols (FTOHs). Circular dichroim spectroscopy showed that PFC binding induced distinctive structural change of the receptor. In dual luciferase reporter assays using transiently transfected Hep G2 cells, PFCs acted as hPPARγ agonists, and their potency correlated with their binding affinity with hPPARγ-LBD. Molecular docking showed that PFCs with different chain length bind with the receptor in different geometry, which may contribute to their differences in binding affinity and transcriptional activity. - Highlights: • Binding affinity between PFCs and PPARγ was evaluated for the first time. • The binding strength was dependent on fluorinated carbon chain and functional group. • PFC binding induced distinctive structural change of the receptor. • PFCs could act as hPPARγ agonists in Hep G2 cells.

  20. Active auxin uptake by zucchini membrane vesicles: quantitation using ESR volume and delta pH determinations

    International Nuclear Information System (INIS)

    Lomax, T.L.; Mehlhorn, R.J.; Briggs, W.R.

    1985-01-01

    Closed and pH-tight membrane vesicles prepared from hypocotyls of 5-day-old dark-grown seedlings of Cucurbita pepo accumulate the plant growth hormone indole-3-acetic acid along an imposed proton gradient (pH low outside, high inside). The use of electron paramagnetic spin probes permitted quantitation both of apparent vesicle volume and magnitude of the pH gradient. Under the experimental conditions used, hormone accumulation was at minimum 20-fold, a value 4 times larger than what one would predict if accumulation reflected only diffusional equilibrium at the measured pH gradient. It is concluded that hormone uptake is an active process, with each protonated molecule of hormone accompanied by an additional proton. Experiments with ionophores confirm that it is the pH gradient itself which drives the uptake

  1. Quantitative structure-activity relationships for predicting potential ecological hazard of organic chemicals for use in regulatory risk assessments.

    Science.gov (United States)

    Comber, Mike H I; Walker, John D; Watts, Chris; Hermens, Joop

    2003-08-01

    The use of quantitative structure-activity relationships (QSARs) for deriving the predicted no-effect concentration of discrete organic chemicals for the purposes of conducting a regulatory risk assessment in Europe and the United States is described. In the United States, under the Toxic Substances Control Act (TSCA), the TSCA Interagency Testing Committee and the U.S. Environmental Protection Agency (U.S. EPA) use SARs to estimate the hazards of existing and new chemicals. Within the Existing Substances Regulation in Europe, QSARs may be used for data evaluation, test strategy indications, and the identification and filling of data gaps. To illustrate where and when QSARs may be useful and when their use is more problematic, an example, methyl tertiary-butyl ether (MTBE), is given and the predicted and experimental data are compared. Improvements needed for new QSARs and tools for developing and using QSARs are discussed.

  2. Perceived barriers to leisure-time physical activity during pregnancy: A literature review of quantitative and qualitative evidence.

    Science.gov (United States)

    Coll, Carolina V N; Domingues, Marlos R; Gonçalves, Helen; Bertoldi, Andréa D

    2017-01-01

    Identify perceived barriers to leisure-time physical activity during pregnancy to inform future interventions aimed at improving physical activity levels in pregnancy. PubMed/Medline and Web of Science databases were systematically searched using a reference period between 1986 and January/2016. A comprehensive search strategy was developed combining the following keywords: (barriers OR constraints OR perceptions OR attitudes) AND (physical activity OR exercise OR motor activity) AND (pregnancy OR pregnant women OR antenatal OR prenatal). Thematic synthesis was conducted to analyze the data. A socioecological model was used to categorize the reported barriers. Twelve quantitative studies and 14 qualitative studies were included. Barriers belonging to the intrapersonal level of the socioecological model were the most reported in the studies and were categorized in five themes as follows: (1) Pregnancy-related symptoms and limitations; (2) Time constraints; (3) Perceptions of already being active, (4) Lack of motivation and (5) Mother-child safety concerns. At the interpersonal level, barriers were coded into two descriptive themes: (1) Lack of advice and information and (2) Lack of social support. Two other themes were used to summarize Environmental, Organizational and Policy barriers: (1) Adverse weather and (2) Lack of resources. A range of relevant barriers to leisure-time physical-activity engagement during pregnancy were identified in this literature review. Pregnancy-related symptoms and limitations barriers were the most reported in studies, regardless of study design. Mother-child safety concerns, lack of advice/information and lack of social support were also important emphasized pregnancy-related barriers to be targeted in future interventions. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  3. VEGF secretion during hypoxia depends on free radicals-induced Fyn kinase activity in mast cells

    International Nuclear Information System (INIS)

    Garcia-Roman, Jonathan; Ibarra-Sanchez, Alfredo; Lamas, Monica; Gonzalez Espinosa, Claudia

    2010-01-01

    Research highlights: → Bone marrow-derived mast cells (BMMCs) secrete functional VEGF but do not degranulate after Cobalt chloride-induced hypoxia. → CoCl 2 -induced VEGF secretion in mast cells occurs by a Ca 2+ -insensitive but brefeldin A and Tetanus toxin-sensitive mechanism. → Trolox and N-acetylcysteine inhibit hypoxia-induced VEGF secretion but only Trolox inhibits FcεRI-dependent anaphylactic degranulation in mast cells. → Src family kinase Fyn activation after free radical production is necessary for hypoxia-induced VEGF secretion in mast cells. -- Abstract: Mast cells (MC) have an important role in pathologic conditions such as asthma and chronic obstructive pulmonary disease (COPD), where hypoxia conduce to deleterious inflammatory response. MC contribute to hypoxia-induced angiogenesis producing factors such as vascular endothelial growth factor (VEGF), but the mechanisms behind the control of hypoxia-induced VEGF secretion in this cell type is poorly understood. We used the hypoxia-mimicking agent cobalt chloride (CoCl 2 ) to analyze VEGF secretion in murine bone marrow-derived mast cells (BMMCs). We found that CoCl 2 promotes a sustained production of functional VEGF, able to induce proliferation of endothelial cells in vitro. CoCl 2 -induced VEGF secretion was independent of calcium rise but dependent on tetanus toxin-sensitive vesicle-associated membrane proteins (VAMPs). VEGF exocytosis required free radicals formation and the activation of Src family kinases. Interestingly, an important deficiency on CoCl 2 -induced VEGF secretion was observed in Fyn kinase-deficient BMMCs. Moreover, Fyn kinase was activated by CoCl 2 in WT cells and this activation was prevented by treatment with antioxidants such as Trolox and N-acetylcysteine. Our results show that BMMCs are able to release VEGF under hypoxic conditions through a tetanus toxin-sensitive mechanism, promoted by free radicals-dependent Fyn kinase activation.

  4. Fenofibrate activates Nrf2 through p62-dependent Keap1 degradation

    International Nuclear Information System (INIS)

    Park, Jeong Su; Kang, Dong Hoon; Lee, Da Hyun; Bae, Soo Han

    2015-01-01

    Peroxisome proliferator-activated receptor α (PPARα) activates the β-oxidation of fatty acids in the liver. Fenofibrate is a potent agonist of PPARα and is used in the treatment of hyperlipidemia. Fenofibrate treatment often induces the production of intracellular reactive oxygen species (ROS), leading to cell death. The nuclear factor erythroid 2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) pathway is an essential component of the defense mechanism against oxidative stress. However, the molecular mechanism underlying the regulation of the Nrf2-Keap1 pathway in fenofibrate-induced cell death is not known. In this study, we demonstrated that fenofibrate induces Keap1 degradation and Nrf2 activation. This fenofibrate-mediated Keap1 degradation is partly dependent on autophagy. Furthermore, fenofibrate-induced Keap1 degradation followed by Nrf2 activation is mainly mediated by p62, which functions as an adaptor protein in the autophagic pathway. Consistent with these findings, ablation of p62 increased fenofibrate-mediated apoptotic cell death associated with ROS accumulation. These results strongly suggest that p62 plays a crucial role in preventing fenofibrate-induced cell death. - Highlights: • Fenofibrate induces cell death by increasing ROS production. • The underlying defense mechanism against this effect is unknown. • Fenofibrate induces autophagy-dependent Keap1 degradation and Nrf2 activation. • This process is p62-dependent; lack of p62 enhanced fenofibrate-mediated apoptosis. • p62 plays a crucial role in preventing fenofibrate-induced cell death

  5. VEGF secretion during hypoxia depends on free radicals-induced Fyn kinase activity in mast cells

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Roman, Jonathan; Ibarra-Sanchez, Alfredo; Lamas, Monica [Departamento de Farmacobiologia, Centro de Investigacion y de Estudios Avanzados del IPN (Cinvestav, IPN) (Mexico); Gonzalez Espinosa, Claudia, E-mail: cgonzal@cinvestav.mx [Departamento de Farmacobiologia, Centro de Investigacion y de Estudios Avanzados del IPN (Cinvestav, IPN) (Mexico)

    2010-10-15

    Research highlights: {yields} Bone marrow-derived mast cells (BMMCs) secrete functional VEGF but do not degranulate after Cobalt chloride-induced hypoxia. {yields} CoCl{sub 2}-induced VEGF secretion in mast cells occurs by a Ca{sup 2+}-insensitive but brefeldin A and Tetanus toxin-sensitive mechanism. {yields} Trolox and N-acetylcysteine inhibit hypoxia-induced VEGF secretion but only Trolox inhibits Fc{epsilon}RI-dependent anaphylactic degranulation in mast cells. {yields} Src family kinase Fyn activation after free radical production is necessary for hypoxia-induced VEGF secretion in mast cells. -- Abstract: Mast cells (MC) have an important role in pathologic conditions such as asthma and chronic obstructive pulmonary disease (COPD), where hypoxia conduce to deleterious inflammatory response. MC contribute to hypoxia-induced angiogenesis producing factors such as vascular endothelial growth factor (VEGF), but the mechanisms behind the control of hypoxia-induced VEGF secretion in this cell type is poorly understood. We used the hypoxia-mimicking agent cobalt chloride (CoCl{sub 2}) to analyze VEGF secretion in murine bone marrow-derived mast cells (BMMCs). We found that CoCl{sub 2} promotes a sustained production of functional VEGF, able to induce proliferation of endothelial cells in vitro. CoCl{sub 2}-induced VEGF secretion was independent of calcium rise but dependent on tetanus toxin-sensitive vesicle-associated membrane proteins (VAMPs). VEGF exocytosis required free radicals formation and the activation of Src family kinases. Interestingly, an important deficiency on CoCl{sub 2}-induced VEGF secretion was observed in Fyn kinase-deficient BMMCs. Moreover, Fyn kinase was activated by CoCl{sub 2} in WT cells and this activation was prevented by treatment with antioxidants such as Trolox and N-acetylcysteine. Our results show that BMMCs are able to release VEGF under hypoxic conditions through a tetanus toxin-sensitive mechanism, promoted by free radicals-dependent

  6. Fenofibrate activates Nrf2 through p62-dependent Keap1 degradation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeong Su [Severance Biomedical Science Institute (Korea, Republic of); Yonsei Biomedical Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Kang, Dong Hoon [Department of Life Science and Ewha Research Center for Systems Biology (Korea, Republic of); The Research Center for Cell Homeostasis, Ewha Womans University, Seoul 127-750 (Korea, Republic of); Lee, Da Hyun [Severance Biomedical Science Institute (Korea, Republic of); Yonsei Biomedical Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Bae, Soo Han, E-mail: soohanbae@yuhs.ac [Severance Biomedical Science Institute (Korea, Republic of); Yonsei Biomedical Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of)

    2015-09-25

    Peroxisome proliferator-activated receptor α (PPARα) activates the β-oxidation of fatty acids in the liver. Fenofibrate is a potent agonist of PPARα and is used in the treatment of hyperlipidemia. Fenofibrate treatment often induces the production of intracellular reactive oxygen species (ROS), leading to cell death. The nuclear factor erythroid 2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) pathway is an essential component of the defense mechanism against oxidative stress. However, the molecular mechanism underlying the regulation of the Nrf2-Keap1 pathway in fenofibrate-induced cell death is not known. In this study, we demonstrated that fenofibrate induces Keap1 degradation and Nrf2 activation. This fenofibrate-mediated Keap1 degradation is partly dependent on autophagy. Furthermore, fenofibrate-induced Keap1 degradation followed by Nrf2 activation is mainly mediated by p62, which functions as an adaptor protein in the autophagic pathway. Consistent with these findings, ablation of p62 increased fenofibrate-mediated apoptotic cell death associated with ROS accumulation. These results strongly suggest that p62 plays a crucial role in preventing fenofibrate-induced cell death. - Highlights: • Fenofibrate induces cell death by increasing ROS production. • The underlying defense mechanism against this effect is unknown. • Fenofibrate induces autophagy-dependent Keap1 degradation and Nrf2 activation. • This process is p62-dependent; lack of p62 enhanced fenofibrate-mediated apoptosis. • p62 plays a crucial role in preventing fenofibrate-induced cell death.

  7. A framework for the quantitative assessment of climate change impacts on water-related activities at the basin scale

    Directory of Open Access Journals (Sweden)

    D. Anghileri

    2011-06-01

    Full Text Available While quantitative assessment of the climate change impact on hydrology at the basin scale is quite addressed in the literature, extension of quantitative analysis to impact on the ecological, economic and social sphere is still limited, although well recognized as a key issue to support water resource planning and promote public participation. In this paper we propose a framework for assessing climate change impact on water-related activities at the basin scale. The specific features of our approach are that: (i the impact quantification is based on a set of performance indicators defined together with the stakeholders, thus explicitly taking into account the water-users preferences; (ii the management policies are obtained by optimal control techniques, linking stakeholder expectations and decision-making; (iii the multi-objective nature of the management problem is fully preserved by simulating a set of Pareto-optimal management policies, which allows for evaluating not only variations in the indicator values but also tradeoffs among conflicting objectives. The framework is demonstrated by application to a real world case study, Lake Como basin (Italy. We show that the most conflicting water-related activities within the basin (i.e. hydropower production and agriculture are likely to be negatively impacted by climate change. We discuss the robustness of the estimated impacts to the climate natural variability and the approximations in modeling the physical system and the socio-economic system, and perform an uncertainty analysis of several sources of uncertainty. We demonstrate that the contribution of natural climate uncertainty is rather remarkable and that, among different modelling uncertainty sources, the one from climate modeling is very significant.

  8. Assessment of cardiac sympathetic nerve activity in children with chronic heart failure using quantitative iodine-123 metaiodobenzylguanidine imaging

    International Nuclear Information System (INIS)

    Karasawa, Kensuke; Ayusawa, Mamoru; Noto, Nobutaka; Sumitomo, Naokata; Okada, Tomoo; Harada, Kensuke

    2000-01-01

    Cardiac sympathetic nerve activity in children with chronic heart failure was examined by quantitative iodine-123 metaiodobenzylguanidine (MIBG) myocardial imaging in 33 patients aged 7.5±6.1 years (range 0-18 years), including 8 with cardiomyopathy, 15 with congenital heart disease, 3 with anthracycrine cardiotoxicity, 3 with myocarditis, 3 with primary pulmonary hypertension and 1 with Pompe's disease. Anterior planar images were obtained 15 min and 3 hr after the injection of iodine-123 MIBG. The cardiac iodine-123 MIBG uptake was assessed as the heart to upper mediastinum uptake activity ratio of the delayed image (H/M) and the cardiac percentage washout rate (%WR). The severity of chronic heart failure was class I (no medication) in 8 patients, class II (no symptom with medication) in 9, class III (symptom even with medication) in 10 and class IV (late cardiac death) in 6. H/M was 2.33±0.22 in chronic heart failure class I, 2.50±0.34 in class II, 1.95±0.61 in class III, and 1.39±0.29 in class IV (p<0.05). %WR was 24.8±12.8% in chronic heart failure class I, 23.3±10.2% in class II, 49.2±24.5% in class III, and 66.3±26.5% in class IV (p<0.05). The low H/M and high %WR were proportionate to the severity of chronic heart failure. Cardiac iodine-123 MIBG showed cardiac adrenergic neuronal dysfunction in children with severe chronic heart failure. Quantitative iodine-123 MIBG myocardial imaging is clinically useful as a predictor of therapeutic outcome and mortality in children with chronic heart failure. (author)

  9. Assessment of cardiac sympathetic nerve activity in children with chronic heart failure using quantitative iodine-123 metaiodobenzylguanidine imaging

    Energy Technology Data Exchange (ETDEWEB)

    Karasawa, Kensuke; Ayusawa, Mamoru; Noto, Nobutaka; Sumitomo, Naokata; Okada, Tomoo; Harada, Kensuke [Nihon Univ., Tokyo (Japan). School of Medicine

    2000-12-01

    Cardiac sympathetic nerve activity in children with chronic heart failure was examined by quantitative iodine-123 metaiodobenzylguanidine (MIBG) myocardial imaging in 33 patients aged 7.5{+-}6.1 years (range 0-18 years), including 8 with cardiomyopathy, 15 with congenital heart disease, 3 with anthracycrine cardiotoxicity, 3 with myocarditis, 3 with primary pulmonary hypertension and 1 with Pompe's disease. Anterior planar images were obtained 15 min and 3 hr after the injection of iodine-123 MIBG. The cardiac iodine-123 MIBG uptake was assessed as the heart to upper mediastinum uptake activity ratio of the delayed image (H/M) and the cardiac percentage washout rate (%WR). The severity of chronic heart failure was class I (no medication) in 8 patients, class II (no symptom with medication) in 9, class III (symptom even with medication) in 10 and class IV (late cardiac death) in 6. H/M was 2.33{+-}0.22 in chronic heart failure class I, 2.50{+-}0.34 in class II, 1.95{+-}0.61 in class III, and 1.39{+-}0.29 in class IV (p<0.05). %WR was 24.8{+-}12.8% in chronic heart failure class I, 23.3{+-}10.2% in class II, 49.2{+-}24.5% in class III, and 66.3{+-}26.5% in class IV (p<0.05). The low H/M and high %WR were proportionate to the severity of chronic heart failure. Cardiac iodine-123 MIBG showed cardiac adrenergic neuronal dysfunction in children with severe chronic heart failure. Quantitative iodine-123 MIBG myocardial imaging is clinically useful as a predictor of therapeutic outcome and mortality in children with chronic heart failure. (author)

  10. Prediction of the Formulation Dependence of the Glass Transition Temperature for Amine-Epoxy Copolymers Using a Quantitative Structure-Property Relationship Based on the AM1 Method

    National Research Council Canada - National Science Library

    Morrill, Jason

    2004-01-01

    A designer Quantitative Structure-Property Relationsbip (QSPR) based upon molecular properties calculated using the AM1 semi-empirical quantum mechanical metbod was developed to predict the glass transition temperature (Tg...

  11. Variability of Pinus halepensis Mill. Essential Oils and Their Antioxidant Activities Depending on the Stage of Growth During Vegetative Cycle.

    Science.gov (United States)

    Djerrad, Zineb; Djouahri, Abderrahmane; Kadik, Leila

    2017-04-01

    The impact of growth stages during vegetative cycle (B 0  - B 5 ) on chemical composition and antioxidant activities of Pinus halepensis Mill. needles essential oils was investigated for the first time. GC and GC/MS analyses pointed to a quantitative variability of components; terpene hydrocarbons derivatives, represented by α-pinene (8.5 - 12.9%), myrcene (17.5 - 21.6%), p-cymene (7.9 - 11.9%) and (Z)-β-caryophyllene (17.3 - 21.2%) as major components, decreased from 88.9% at B 0 growth stage to 66.9% at B 5 growth stage, whereas oxygenated derivatives, represented by caryophyllene oxide (5.4 - 12.6%) and terpinen-4-ol (0.4 - 3.3%) as major components, increased from 7% at B 0 growth stage to 28.4% at B 5 growth stage. Furthermore, our findings showed that essential oil of P. halepensis needles collected at B 5 growth stage possess higher antioxidant activities by four different testing systems than those collected at B 0  - B 4 growth stages. This highlighted variability led to conclude that we should select essential oils to be investigated carefully depending on growth stage, in order to have the highest effectiveness of essential oil in terms of biological activities for human health purposes. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  12. Activation of cAMP-dependent signaling pathway induces mouse organic anion transporting polypeptide 2 expression.

    Science.gov (United States)

    Chen, Chuan; Cheng, Xingguo; Dieter, Matthew Z; Tanaka, Yuji; Klaassen, Curtis D

    2007-04-01

    Rodent Oatp2 is a hepatic uptake transporter for such compounds as cardiac glycosides. In the present study, we found that fasting resulted in a 2-fold induction of Oatp2 expression in liver of mice. Because the cAMP-protein kinase A (PKA) signaling pathway is activated during fasting, the role of this pathway in Oatp2 induction during fasting was examined. In Hepa-1c1c7 cells, adenylyl cyclase activator forskolin as well as two cellular membrane-permeable cAMP analogs, dibutyryl cAMP and 8-bromo-cAMP, induced Oatp2 mRNA expression in a time- and dose-dependent manner. These three chemicals induced reporter gene activity in cells transfected with a luciferase reporter gene construct containing a 7.6-kilobase (kb) 5'-flanking region of mouse Oatp2. Transient transfection of cells with 5'-deletion constructs derived from the 7.6-kb Oatp2 promoter reporter gene construct, as well as 7.6-kb constructs in which a consensus cAMP response element (CRE) half-site CGTCA (-1808/-1804 bp) was mutated or deleted, confirms that this CRE site was required for the induction of luciferase activity by forskolin. Luciferase activity driven by the Oatp2 promoter containing this CRE site was induced in cells cotransfected with a plasmid encoding the protein kinase A catalytic subunit. Cotransfection of cells with a plasmid encoding the dominant-negative CRE binding protein (CREB) completely abolished the inducibility of the reporter gene activity by forskolin. In conclusion, induction of Oatp2 expression in liver of fasted mice may be caused by activation of the cAMP-dependent signaling pathway, with the CRE site (-1808/-1804) and CREB being the cis- and trans-acting factors mediating the induction, respectively.

  13. Goal- and retrieval-dependent activity in the striatum during memory recognition.

    Science.gov (United States)

    Clos, Mareike; Schwarze, Ulrike; Gluth, Sebastian; Bunzeck, Nico; Sommer, Tobias

    2015-06-01

    The striatum has been associated with successful memory retrieval but the precise functional link still remains unclear. One hypothesis is that striatal activity reflects an active evaluation process of the retrieval outcome dependent on the current behavioral goals rather than being a consequence of memory reactivation. We have recently shown that the striatum also correlates with confidence in memory recognition, which could reflect high subjective value ascribed to high certainty decisions. To examine whether striatal activity during memory recognition reflects subjective value indeed, we conducted an fMRI study using a recognition memory paradigm in which the participants rated not only the recognition confidence but also indicated the pleasantness associated with the previous memory retrieval. The results demonstrated a high positive correlation between confidence and pleasantness both on the behavioral and brain activation level particularly in the striatum. As almost all of variance in the striatal confidence signal could be explained by experienced pleasantness, this part of the striatal memory recognition response probably corresponds to greater subjective value of high confidence responses. While perceived oldness was also strongly correlated with striatal activity, this activation pattern was clearly distinct from that associated with confidence and pleasantness and thus could not be explained by higher subjective value to detect "old" items. Together, these results show that at least two independent processes contribute to striatal activation in recognition memory: a more flexible evaluation response dependent on context and goals captured by memory confidence and a potentially retrieval-related response captured by perceived oldness. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Zinc-dependent multi-conductance channel activity in mitochondria isolated from ischemic brain.

    Science.gov (United States)

    Bonanni, Laura; Chachar, Mushtaque; Jover-Mengual, Teresa; Li, Hongmei; Jones, Adrienne; Yokota, Hidenori; Ofengeim, Dimitry; Flannery, Richard J; Miyawaki, Takahiro; Cho, Chang-Hoon; Polster, Brian M; Pypaert, Marc; Hardwick, J Marie; Sensi, Stefano L; Zukin, R Suzanne; Jonas, Elizabeth A

    2006-06-21

    Transient global ischemia is a neuronal insult that induces delayed cell death. A hallmark event in the early post-ischemic period is enhanced permeability of mitochondrial membranes. The precise mechanisms by which mitochondrial function is disrupted are, as yet, unclear. Here we show that global ischemia promotes alterations in mitochondrial membrane contact points, a rise in intramitochondrial Zn2+, and activation of large, multi-conductance channels in mitochondrial outer membranes by 1 h after insult. Mitochondrial channel activity was associated with enhanced protease activity and proteolytic cleavage of BCL-xL to generate its pro-death counterpart, deltaN-BCL-xL. The findings implicate deltaN-BCL-xL in large, multi-conductance channel activity. Consistent with this, large channel activity was mimicked by introduction of recombinant deltaN-BCL-xL to control mitochondria and blocked by introduction of a functional BCL-xL antibody to post-ischemic mitochondria via the patch pipette. Channel activity was also inhibited by nicotinamide adenine dinucleotide, indicative of a role for the voltage-dependent anion channel (VDAC) of the outer mitochondrial membrane. In vivo administration of the membrane-impermeant Zn2+ chelator CaEDTA before ischemia or in vitro application of the membrane-permeant Zn2+ chelator tetrakis-(2-pyridylmethyl) ethylenediamine attenuated channel activity, suggesting a requirement for Zn2+. These findings reveal a novel mechanism by which ischemic insults disrupt the functional integrity of the outer mitochondrial membrane and implicate deltaN-BCL-xL and VDAC in the large, Zn2+-dependent mitochondrial channels observed in post-ischemic hippocampal mitochondria.

  15. ROS-activated ATM-dependent phosphorylation of cytoplasmic substrates identified by large scale phosphoproteomics screen

    DEFF Research Database (Denmark)

    Kozlov, Sergei V; Waardenberg, Ashley J; Engholm-Keller, Kasper

    2016-01-01

    ATM (ataxia-telangiectasia, mutated) protein plays a central role in phosphorylating a network of proteins in response to DNA damage. These proteins function in signalling pathways designed to maintain the stability of the genome and minimize the risk of disease by controlling cell cycle checkpoi......ATM (ataxia-telangiectasia, mutated) protein plays a central role in phosphorylating a network of proteins in response to DNA damage. These proteins function in signalling pathways designed to maintain the stability of the genome and minimize the risk of disease by controlling cell cycle...... checkpoints, initiating DNA repair and regulating gene expression. ATM kinase can be activated by a variety of stimuli, including oxidative stress. Here we confirmed activation of cytoplasmic ATM by autophosphorylation at multiple sites. Then we employed a global quantitative phosphoproteomics approach...... to identify cytoplasmic proteins altered in their phosphorylation state in control and A-T (ataxia-telangiectasia) cells in response to oxidative damage. We demonstrated that ATM was activated by oxidative damage in the cytoplasm as well as in the nucleus and identified a total of 9,833 phosphorylation sites...

  16. Application of Scharer's quantitative method for the determination of residual alkaline phosphatase activity in standard Minas

    Directory of Open Access Journals (Sweden)

    C.F. Soares

    2013-08-01

    Full Text Available Milk pasteurization is a critical issue in the dairy industry, and failures in this process can affect final product safety. Scharer's enzymatic method is still traditionally used to verify pasteurization efficiency compliance, and it is based on screening for residual alkaline phosphatase in milk. Although several methods are used to quantify enzymatic activity to assess milk pasteurization efficiency, there is a small amount of published data regarding the use of these methods to quantify alkaline phosphatase in cheese. In this study, the Scharer's modified method was used to determine the levels of residual alkaline phosphatase in standard minas cheese, before and after 20 days of ripening. The cheeses were made using raw or pasteurized milk with the addition of different concentrations of raw milk (0; 0.05%; 0.10%; 0.20%; and 0.50%. In the fresh cheese samples, the method showed a sensitivity of only 0.50% with the addition of raw milk to the pasteurized milk used to make cheese. In addition, levels of up 0.20% of raw milk in pasteurized milk, the concentrations of phenol was inferior to 1μg phenol/g of dairy product which is the preconized indicator value for adequate pasteurization.

  17. Exercise dependence score in patients with longstanding eating disorders and controls: the importance of affect regulation and physical activity intensity.

    Science.gov (United States)

    Bratland-Sanda, Solfrid; Martinsen, Egil W; Rosenvinge, Jan H; Rø, Oyvind; Hoffart, Asle; Sundgot-Borgen, Jorunn

    2011-01-01

    To examine associations among exercise dependence score, amount of physical activity and eating disorder (ED) symptoms in patients with longstanding ED and non-clinical controls. Adult female inpatients (n = 59) and 53 age-matched controls participated in this cross sectional study. Assessments included the eating disorders examination, eating disorders inventory, exercise dependence scale, reasons for exercise inventory, and MTI Actigraph accelerometer. Positive associations were found among vigorous, not moderate, physical activity, exercise dependence score and ED symptoms in patients. In the controls, ED symptoms were negatively associated with vigorous physical activity and not correlated with exercise dependence score. Exercise for negative affect regulation, not weight/appearance, and amount of vigorous physical activity were explanatory variables for exercise dependence score in both groups. The positive associations among exercise dependence score, vigorous physical activity and ED symptoms need proper attention in the treatment of longstanding ED. Copyright © 2011 John Wiley & Sons, Ltd and Eating Disorders Association.

  18. Blood lactate clearance after maximal exercise depends on active recovery intensity.

    Science.gov (United States)

    Devlin, J; Paton, B; Poole, L; Sun, W; Ferguson, C; Wilson, J; Kemi, O J

    2014-06-01

    High-intensity exercise is time-limited by onset of fatigue, marked by accumulation of blood lactate. This is accentuated at maximal, all-out exercise that rapidly accumulates high blood lactate. The optimal active recovery intensity for clearing lactate after such maximal, all-out exercise remains unknown. Thus, we studied the intensity-dependence of lactate clearance during active recovery after maximal exercise. We constructed a standardized maximal, all-out treadmill exercise protocol that predictably lead to voluntary exhaustion and blood lactate concentration>10 mM. Next, subjects ran series of all-out bouts that increased blood lactate concentration to 11.5±0.2 mM, followed by recovery exercises ranging 0% (passive)-100% of the lactate threshold. Repeated measurements showed faster lactate clearance during active versus passive recovery (P40%>passive recovery, Pexercise clears accumulated blood lactate faster than passive recovery in an intensity-dependent manner, with maximum clearance occurring at active recovery of 80% of lactate threshold.

  19. Time-dependent changes in rat lymphocyte activity in response to isolation

    International Nuclear Information System (INIS)

    Jessop, J.J.; Bayer, B.M.

    1986-01-01

    The authors have found that isolation of rats, previously adapted to group-housing conditions, resulted in time-dependent changes in mitogenic and cytolytic responses of lymphocytes. A depression (40-60%) of the uptake of 3 H-thymidine by splenic and blood lymphocytes stimulated with either phytohemagglutinin (PHA) or lipopolysaccharide (LPS) was observed during the first 48 hours after transfer of the animals to individual cages. Within 4 days the mitogenic response increased and was comparable to that of animals which had been continuously group-housed. The response continued to increase and by 10 days was enhanced by 2 to 4 fold and remained elevated for at least 8 weeks. Similar changes in activity were observed with both splenic and blood lymphocytes, however, thymic lymphocytes taken from isolated animals demonstrated no change in reactivity to PHA. As with mitogenic responses, the cytolytic activity of splenic lymphocytes was also depressed during the initial days of isolation and as isolation continued, the activity returned to normal and was significantly enhanced (80%) within 5 weeks. These data show that changes in lymphocyte activity are dependent on the duration of exposure to isolated housing conditions and may be a part of the acute, adaptive and chronic phases of the response of rats to the stress of isolation

  20. Dependence of Photocatalytic Activity of TiO2-SiO2 Nanopowders

    Directory of Open Access Journals (Sweden)

    M. Riazian

    2014-10-01

    Full Text Available Structural properties and chemical composition change the photocatalytic activity in TiO2-SiO2 nanopowder composite. The SiO2-TiO2 nanostructure is synthesized based on sol–gel method. The nanoparticles are characterized by x-ray fluorescents (XRF, x- ray diffraction (XRD, tunneling electron microscopy (TEM, field emission scanning electron microscopy (FE-SEM, UV-vis. Spectrophotometer and furrier transmission create infrared absorption (FTIR techniques. The rate constant k for the degradation of methylen blue in its aqueous solution under UV irradiation is determined as a measure of photocatalytic activity. Dependence between photocatalytic activity and SiO2 content in the composite is determined. Rate constant k is found dependent on the content of SiO2 in the composite that calcined at 900 oC. The addition of low composition SiO2 to the TiO2 matrix (lower than 45% enhances the photocatalytic activity due to thermal stability and increasing in the surface area. The effects of chemical compositions on the surface topography and the crystallization of phases are studied.

  1. A Quantitative Study on Packing Density and Pozzolanic Activity of Cementitious Materials Based on the Compaction Packing Model

    International Nuclear Information System (INIS)

    Gong, Jianqing; Chou, Kai; Huang, Zheng Yu; Zhao, Minghua

    2014-01-01

    A brief introduction to the theoretical basis of compaction packing model (CPM) and an over-view of the principle of the specific strength method provided the starting point of this study. Then, research on quantitative relations was carried out to find the correlation between the contribution rate of the pozzolanic activity and the contribution value of packing density when CPM was applied to fine powder mixture systems. The concept of the contribution value of the packing density being in direct correspondence with the contribution rate was proved by the compressive strength results and SEM images. The results indicated that the variation rule of the contribution rate of the pozzolanic activity is similar to that of the contribution value of packing density as calculated by CPM. This means the contribution value of the packing density could approximately simulate the change tendency of the contribution rate of the pozzolanic activity, which is of significant value for the future of mix designs for high and ultra-high performance concrete

  2. Quantitative structure--property relationships for enhancing predictions of synthetic organic chemical removal from drinking water by granular activated carbon.

    Science.gov (United States)

    Magnuson, Matthew L; Speth, Thomas F

    2005-10-01

    Granular activated carbon is a frequently explored technology for removing synthetic organic contaminants from drinking water sources. The success of this technology relies on a number of factors based not only on the adsorptive properties of the contaminant but also on properties of the water itself, notably the presence of substances in the water which compete for adsorption sites. Because it is impractical to perform field-scale evaluations for all possible contaminants, the pore surface diffusion model (PSDM) has been developed and used to predict activated carbon column performance using single-solute isotherm data as inputs. Many assumptions are built into this model to account for kinetics of adsorption and competition for adsorption sites. This work further evaluates and expands this model, through the use of quantitative structure-property relationships (QSPRs) to predict the effect of natural organic matter fouling on activated carbon adsorption of specific contaminants. The QSPRs developed are based on a combination of calculated topographical indices and quantum chemical parameters. The QSPRs were evaluated in terms of their statistical predictive ability,the physical significance of the descriptors, and by comparison with field data. The QSPR-enhanced PSDM was judged to give results better than what could previously be obtained.

  3. Quantitative MR characterization of disease activity in the knee in children with juvenile idiopathic arthritis: a longitudinal pilot study

    International Nuclear Information System (INIS)

    Workie, Dagnachew W.; Graham, T.B.; Laor, Tal; Racadio, Judy M.; Rajagopal, Akila; O'Brien, Kendall J.; Bommer, Wendy A.; Shire, Norah J.; Dardzinski, Bernard J.

    2007-01-01

    The development of a quantifiable and noninvasive method of monitoring disease activity and response to therapy is vital for arthritis management. The purpose of this study was to investigate the utility of quantitative dynamic contrast-enhanced MRI (DCE-MRI) based on pharmacokinetic (PK) modeling to evaluate disease activity in the knee and correlate the results with the clinical assessment in children with juvenile idiopathic arthritis (JIA). A group of 17 children with JIA underwent longitudinal clinical and laboratory assessment and DCE-MRI of the knee at enrollment, 3 months, and 12 months. A PK model was employed using MRI signal enhancement data to give three parameters, K trans ' (min -1 ), k ep (min -1 ), and V p ' and to calculate synovial volume. The PK parameters, synovial volumes, and clinical and laboratory assessments in most children were significantly decreased (P < 0.05) at 12 months when compared to the enrollment values. There was excellent correlation between the PK and synovial volume and the clinical and laboratory assessments. Differences in MR and clinical parameter values in individual subjects illustrate persistent synovitis when in clinical remission. A decrease in PK parameter values obtained from DCE-MRI in children with JIA likely reflects diminution of disease activity. This technique may be used as an objective follow-up measure of therapeutic efficacy in patients with JIA. MR imaging can detect persistent synovitis in patients considered to be in clinical remission. (orig.)

  4. Microbial dynamics and enzyme activities in tropical Andosols depending on land use and nutrient inputs

    Science.gov (United States)

    Mganga, Kevin; Razavi, Bahar; Kuzyakov, Yakov

    2015-04-01

    Microbial decomposition of soil organic matter is mediated by enzymes and is a key source of terrestrial CO2 emissions. Microbial and enzyme activities are necessary to understand soil biochemical functioning and identify changes in soil quality. However, little is known about land use and nutrients availability effects on enzyme activities and microbial processes, especially in tropical soils of Africa. This study was conducted to examine how microbial and enzyme activities differ between different land uses and nutrient availability. As Andosols of Mt. Kilimanjaro are limited by nutrient concentrations, we hypothesize that N and P additions will stimulate enzyme activity. N and P were added to soil samples (0-20 cm) representing common land use types in East Africa: (1) savannah, (2) maize fields, (3) lower montane forest, (4) coffee plantation, (5) grasslands and (6) traditional Chagga homegardens. Total CO2 efflux from soil, microbial biomass and activities of β-glucosidase, cellobiohydrolase, chitinase and phosphatase involved in C, N and P cycling, respectively was monitored for 60 days. Total CO2 production, microbial biomass and enzyme activities varied in the order forest soils > grassland soils > arable soils. Increased β-glucosidase and cellobiohydrolase activities after N addition of grassland soils suggest that microorganisms increased N uptake and utilization to produce C-acquiring enzymes. Low N concentration in all soils inhibited chitinase activity. Depending on land use, N and P addition had an inhibitory or neutral effect on phosphatase activity. We attribute this to the high P retention of Andosols and low impact of N and P on the labile P fractions. Enhanced CO2 production after P addition suggests that increased P availability could stimulate soil organic matter biodegradation in Andosols. In conclusion, land use and nutrients influenced soil enzyme activities and microbial dynamics and demonstrated the decline in soil quality after landuse

  5. Decrease in the cytosolic NADP+-dependent isocitrate dehydrogenase activity through porcine sperm capacitation.

    Science.gov (United States)

    Katoh, Yuki; Tamba, Michiko; Matsuda, Manabu; Kikuchi, Kazuhiro; Okamura, Naomichi

    2018-02-26

    In order to understand the molecular mechanisms involved in the sperm capacitation, we have identified the proteins tyrosine-phosphorylated during the capacitation especially in conjunction with the regulation of the levels of reactive oxygen species (ROS) in sperm. In the present study, the effects of the tyrosine phosphorylation of cytosolic NADP + -dependent isocitrate dehydrogenase (IDPc) on its catalytic activity and on the levels of ROS in sperm have been studied. The tyrosine phosphorylated IDPc showed a significantly lowered enzymatic activity. The immunocytochemical analyses using the highly specific antisera against IDPc revealed that IDPc was mainly localized to the principal piece of the porcine sperm flagellum. As IDPc is one of the major NADPH regenerating enzymes in porcine sperm, it is strongly suggested that the decrease in IDPc activity is involved in the increased levels of ROS, which results in the induction of hyperactivated flagellar movement and capacitation. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Catalase and NO CATALASE ACTIVITY1 Promote Autophagy-Dependent Cell Death in Arabidopsis

    DEFF Research Database (Denmark)

    Hackenberg, Thomas; Juul, Trine Maxel; Auzina, Aija

    2013-01-01

    Programmed cell death often depends on generation of reactive oxygen species, which can be detoxified by antioxidative enzymes, including catalases. We previously isolated catalase-deficient mutants (cat2) in a screen for resistance to hydroxyurea-induced cell death. Here, we identify...... an Arabidopsis thaliana hydroxyurea-resistant autophagy mutant, atg2, which also shows reduced sensitivity to cell death triggered by the bacterial effector avrRpm1. To test if catalase deficiency likewise affected both hydroxyurea and avrRpm1 sensitivity, we selected mutants with extremely low catalase...... activities and showed that they carried mutations in a gene that we named NO CATALASE ACTIVITY1 (NCA1). nca1 mutants showed severely reduced activities of all three catalase isoforms in Arabidopsis, and loss of NCA1 function led to strong suppression of RPM1-triggered cell death. Basal and starvation...

  7. Dihydromyricetin promotes hepatocellular carcinoma regression via a p53 activation-dependent mechanism

    Science.gov (United States)

    Zhang, Qingyu; Liu, Jie; Liu, Bin; Xia, Juan; Chen, Nianping; Chen, Xiaofeng; Cao, Yi; Zhang, Chen; Lu, Caijie; Li, Mingyi; Zhu, Runzhi

    2014-04-01

    The development of antitumor chemotherapy drugs remains a key goal for oncologists, and natural products provide a vast resource for anti-cancer drug discovery. In the current study, we found that the flavonoid dihydromyricetin (DHM) exhibited antitumor activity against liver cancer cells, including primary cells obtained from hepatocellular carcinoma (HCC) patients. In contrast, DHM was not cytotoxic to immortalized normal liver cells. Furthermore, DHM treatment resulted in the growth inhibition and remission of xenotransplanted tumors in nude mice. Our results further demonstrated that this antitumor activity was caused by the activation of the p53-dependent apoptosis pathway via p53 phosphorylation at serine (15Ser). Moreover, our results showed that DHM plays a dual role in the induction of cell death when administered in combination with cisplatin, a common clinical drug that kills primary hepatoma cells but not normal liver cells.

  8. TU-F-12A-02: Quantitative Characterization of Normal Bone Marrow Proliferative Activity with FLT PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Weisse, N; Jeraj, R [Department of Medical Physics, University of Wisconsin, Madison, WI (United States)

    2014-06-15

    Purpose: [F-18]FLT PET is a tool for assessing health of bone marrow by evaluating its proliferative activity. This study establishes a baseline quantitative characterization of healthy marrow proliferation to aid in diagnosis of hematological disease. Methods: 31 patients (20 male, 11 female, 41–76 years) being treated for solid cancers with no history of hematological disease, osseous metastatic disease, or radiation therapy received pre-treatment FLT PET/CT scans. Total bone marrow was isolated from whole body FLT PET images by manually removing organs and applying a standardize uptake value (SUV) threshold of 1.0. Because adult marrow is concentrated in the axial skeleton, quantitative total bone marrow analysis (QTBMA) was used to isolate marrow in the lumbar spine, thoracic spine, sacrum, and pelvis for analysis. SUVmean, SUVmax, and SUVCV were used to quantify bone marrow proliferation. Correlations were explored between SUV and patient characteristics including age, weight, height, and BMI using the Spearman coefficient (ρ). Results: The population-averaged whole-skeleton SUVmean, SUVmax, and SUVCV were 3.0±0.6, 18.4±5.7, and 0.6±0.1, respectively. Uptake values in the axial skeleton were similar to the whole-skeleton demonstrated by SUVmean in the thoracic spine (3.6±0.6), lumbar spine (3.3±0.5), sacrum (3.0±0.6), and pelvis regions (2.8±0.5). Whole-skeleton SUVmax correlated with patient weight (ρ=0.47, p<0.01) and BMI (ρ=0.60, p<0.01), suggesting marrow activity is related to the body's burden. SUV measures in the thoracic spine, lumbar spine, sacrum, and pelvis were negatively correlated with age (ρ:−0.41 to −0.46, p≤0.02). These negative correlations reflect the fact that active marrow in the adult skeleton is localized in the axial skeleton and decreases with age. Conclusions: Normal bone marrow characterizations were determined using FLT

  9. Heme Oxygenase-1 Inhibits HLA Class I Antibody-Dependent Endothelial Cell Activation.

    Directory of Open Access Journals (Sweden)

    Eva Zilian

    Full Text Available Antibody-mediated rejection (AMR is a key limiting factor for long-term graft survival in solid organ transplantation. Human leukocyte antigen (HLA class I (HLA I antibodies (Abs play a major role in the pathogenesis of AMR via their interactions with HLA molecules on vascular endothelial cells (ECs. The antioxidant enzyme heme oxygenase (HO-1 has anti-inflammatory functions in the endothelium. As complement-independent effects of HLA I Abs can activate ECs, it was the goal of the current study to investigate the role of HO-1 on activation of human ECs by HLA I Abs. In cell cultures of various primary human macro- and microvascular ECs treatment with monoclonal pan- and allele-specific HLA I Abs up-regulated the expression of inducible proinflammatory adhesion molecules and chemokines (vascular cell adhesion molecule-1 [VCAM-1], intercellular cell adhesion molecule-1 [ICAM-1], interleukin-8 [IL-8] and monocyte chemotactic protein 1 [MCP-1]. Pharmacological induction of HO-1 with cobalt-protoporphyrin IX reduced, whereas inhibition of HO-1 with either zinc-protoporphyrin IX or siRNA-mediated knockdown increased HLA I Ab-dependent up-regulation of VCAM-1. Treatment with two carbon monoxide (CO-releasing molecules, which liberate the gaseous HO product CO, blocked HLA I Ab-dependent EC activation. Finally, in an in vitro adhesion assay exposure of ECs to HLA I Abs led to increased monocyte binding, which was counteracted by up-regulation of HO-1. In conclusion, HLA I Ab-dependent EC activation is modulated by endothelial HO-1 and targeted induction of this enzyme may be a novel therapeutic approach for the treatment of AMR in solid organ transplantation.

  10. Diadenosine pentaphosphate affects electrical activity in guinea pig atrium via activation of potassium acetylcholine-dependent inward rectifier.

    Science.gov (United States)

    Abramochkin, Denis V; Karimova, Viktoria M; Filatova, Tatiana S; Kamkin, Andre

    2017-07-01

    Diadenosine pentaphosphate (Ap5A) belongs to the family of diadenosine polyphosphates, endogenously produced compounds that affect vascular tone and cardiac performance when released from platelets. The previous findings indicate that Ap5A shortens action potentials (APs) in rat myocardium via activation of purine P2 receptors. The present study demonstrates alternative mechanism of Ap5A electrophysiological effects found in guinea pig myocardium. Ap5A (10 -4  M) shortens APs in guinea pig working atrial myocardium and slows down pacemaker activity in the sinoatrial node. P1 receptors antagonist DPCPX (10 -7  M) or selective GIRK channels blocker tertiapin (10 -6  M) completely abolished all Ap5A effects, while P2 blocker PPADS (10 -4  M) was ineffective. Patch-clamp experiments revealed potassium inward rectifier current activated by Ap5A in guinea pig atrial myocytes. The current was abolished by DPCPX or tertiapin and therefore was considered as potassium acetylcholine-dependent inward rectifier (I KACh ). Thus, unlike rat, in guinea pig atrium Ap5A produces activation of P1 receptors and subsequent opening of KACh channels leading to negative effects on cardiac electrical activity.

  11. Cell cycle-dependent Rho GTPase activity dynamically regulates cancer cell motility and invasion in vivo.

    Science.gov (United States)

    Kagawa, Yoshinori; Matsumoto, Shinji; Kamioka, Yuji; Mimori, Koshi; Naito, Yoko; Ishii, Taeko; Okuzaki, Daisuke; Nishida, Naohiro; Maeda, Sakae; Naito, Atsushi; Kikuta, Junichi; Nishikawa, Keizo; Nishimura, Junichi; Haraguchi, Naotsugu; Takemasa, Ichiro; Mizushima, Tsunekazu; Ikeda, Masataka; Yamamoto, Hirofumi; Sekimoto, Mitsugu; Ishii, Hideshi; Doki, Yuichiro; Matsuda, Michiyuki; Kikuchi, Akira; Mori, Masaki; Ishii, Masaru

    2013-01-01

    The mechanism behind the spatiotemporal control of cancer cell dynamics and its possible association with cell proliferation has not been well established. By exploiting the intravital imaging technique, we found that cancer cell motility and invasive properties were closely associated with the cell cycle. In vivo inoculation of human colon cancer cells bearing fluorescence ubiquitination-based cell cycle indicator (Fucci) demonstrated an unexpected phenomenon: S/G2/M cells were more motile and invasive than G1 cells. Microarray analyses showed that Arhgap11a, an uncharacterized Rho GTPase-activating protein (RhoGAP), was expressed in a cell-cycle-dependent fashion. Expression of ARHGAP11A in cancer cells suppressed RhoA-dependent mechanisms, such as stress fiber formation and focal adhesion, which made the cells more prone to migrate. We also demonstrated that RhoA suppression by ARHGAP11A induced augmentation of relative Rac1 activity, leading to an increase in the invasive properties. RNAi-based inhibition of Arhgap11a reduced the invasion and in vivo expansion of cancers. Additionally, analysis of human specimens showed the significant up-regulation of Arhgap11a in colon cancers, which was correlated with clinical invasion status. The present study suggests that ARHGAP11A, a cell cycle-dependent RhoGAP, is a critical regulator of cancer cell mobility and is thus a promising therapeutic target in invasive cancers.

  12. Cell cycle-dependent Rho GTPase activity dynamically regulates cancer cell motility and invasion in vivo.

    Directory of Open Access Journals (Sweden)

    Yoshinori Kagawa

    Full Text Available The mechanism behind the spatiotemporal control of cancer cell dynamics and its possible association with cell proliferation has not been well established. By exploiting the intravital imaging technique, we found that cancer cell motility and invasive properties were closely associated with the cell cycle. In vivo inoculation of human colon cancer cells bearing fluorescence ubiquitination-based cell cycle indicator (Fucci demonstrated an unexpected phenomenon: S/G2/M cells were more motile and invasive than G1 cells. Microarray analyses showed that Arhgap11a, an uncharacterized Rho GTPase-activating protein (RhoGAP, was expressed in a cell-cycle-dependent fashion. Expression of ARHGAP11A in cancer cells suppressed RhoA-dependent mechanisms, such as stress fiber formation and focal adhesion, which made the cells more prone to migrate. We also demonstrated that RhoA suppression by ARHGAP11A induced augmentation of relative Rac1 activity, leading to an increase in the invasive properties. RNAi-based inhibition of Arhgap11a reduced the invasion and in vivo expansion of cancers. Additionally, analysis of human specimens showed the significant up-regulation of Arhgap11a in colon cancers, which was correlated with clinical invasion status. The present study suggests that ARHGAP11A, a cell cycle-dependent RhoGAP, is a critical regulator of cancer cell mobility and is thus a promising therapeutic target in invasive cancers.

  13. Voltage-gated potassium channels regulate calcium-dependent pathways involved in human T lymphocyte activation.

    Science.gov (United States)

    Lin, C S; Boltz, R C; Blake, J T; Nguyen, M; Talento, A; Fischer, P A; Springer, M S; Sigal, N H; Slaughter, R S; Garcia, M L

    1993-03-01

    The role that potassium channels play in human T lymphocyte activation has been investigated by using specific potassium channel probes. Charybdotoxin (ChTX), a blocker of small conductance Ca(2+)-activated potassium channels (PK,Ca) and voltage-gated potassium channels (PK,V) that are present in human T cells, inhibits the activation of these cells. ChTX blocks T cell activation induced by signals (e.g., anti-CD2, anti-CD3, ionomycin) that elicit a rise in intracellular calcium ([Ca2+]i) by preventing the elevation of [Ca2+]i in a dose-dependent manner. However, ChTX has no effect on the activation pathways (e.g., anti-CD28, interleukin 2 [IL-2]) that are independent of a rise in [Ca2+]i. In the former case, both proliferative response and lymphokine production (IL-2 and interferon gamma) are inhibited by ChTX. The inhibitory effect of ChTX can be demonstrated when added simultaneously, or up to 4 h after the addition of the stimulants. Since ChTX inhibits both PK,Ca and PK,V, we investigated which channel is responsible for these immunosuppressive effects with the use of two other peptides, noxiustoxin (NxTX) and margatoxin (MgTX), which are specific for PK,V. These studies demonstrate that, similar to ChTX, both NxTX and MgTX inhibit lymphokine production and the rise in [Ca2+]i. Taken together, these data provide evidence that blockade of PK,V affects the Ca(2+)-dependent pathways involved in T lymphocyte proliferation and lymphokine production by diminishing the rise in [Ca2+]i that occurs upon T cell activation.

  14. Platelet-activating factor increases platelet-dependent glycoconjugate secretion from tracheal submucosal gland

    International Nuclear Information System (INIS)

    Sasaki, T.; Shimura, S.; Ikeda, K.; Sasaki, H.; Takishima, T.

    1989-01-01

    Using isolated glands from feline trachea, we examined the effect of platelet-activating factor (PAF) on radiolabeled glycoconjugate release and glandular contraction by measuring induced tension in the absence or presence of platelets. PAF alone did not produce any significant glandular contraction nor any significant change in glycoconjugate release from isolated glands. In the presence of purified platelets containing no plasma, PAF (10(-8) to 10(-5) M) produced significant glycoconjugate secretion in a dose-dependent fashion, but it produced no significant glandular contraction. PAF-evoked glycoconjugate secretion was time dependent, reaching a peak response of 277% of control 15-30 min after the exposure of isolated glands to 10(-5) M PAF in the presence of platelets and returning to 135% of controls at 2 h. Platelets alone did not produce any significant stimulation in glycoconjugate release. CV-3988, a known PAF antagonist, inhibited the secretory response to PAF. Methysergide, a known antagonist to receptors for 5-hydroxytryptamine, did not alter PAF-evoked glycoconjugate secretion. Both indomethacin and SQ 29,548, a thromboxane receptor antagonist, abolished the PAF-evoked glycoconjugate secretion from isolated submucosal glands. Epithiomethanothromboxane A2, a stable thromboxane A2 analogue, produced a significant increase in glycoconjugate secretion in a dose-dependent fashion. These findings indicate that PAF increases glycoconjugate release in the presence of platelets and that the increase is dependent on some aspect of platelet function, namely thromboxane generation

  15. Brain activations during bimodal dual tasks depend on the nature and combination of component tasks

    Directory of Open Access Journals (Sweden)

    Emma eSalo

    2015-02-01

    Full Text Available We used functional magnetic resonance imaging to investigate brain activations during nine different dual tasks in which the participants were required to simultaneously attend to concurrent streams of spoken syllables and written letters. They performed a phonological, spatial or simple (speaker-gender or font-shade discrimination task within each modality. We expected to find activations associated specifically with dual tasking especially in the frontal and parietal cortices. However, no brain areas showed systematic dual task enhancements common for all dual tasks. Further analysis revealed that dual tasks including component tasks that were according to Baddeley’s model modality atypical, that is, the auditory spatial task or the visual phonological task, were not associated with enhanced frontal activity. In contrast, for other dual tasks, activity specifically associated with dual tasking was found in the left or bilateral frontal cortices. Enhanced activation in parietal areas, however, appeared not to be specifically associated with dual tasking per se, but rather with intermodal attention switching. We also expected effects of dual tasking in left frontal supramodal phonological processing areas when both component tasks required phonological processing and in right parietal supramodal spatial processing areas when both tasks required spatial processing. However, no such effects were found during these dual tasks compared with their component tasks performed separately. Taken together, the current results indicate that activations during dual tasks depend in a complex manner on specific demands of component tasks.

  16. Alternative pathways of thromboplastin-dependent activation of human factor X in plasma

    International Nuclear Information System (INIS)

    Marlar, R.A.; Griffin, J.H.

    1981-01-01

    To determine the interrelationships of the major coagulation pathways, the activation of 3H-labeled factor X in normal and various deficient human plasmas was evaluated when clotting was triggered by dilute rabbit or human thromboplastin. Various dilutions of thromboplastin and calcium were added to plasma samples containing 3H-factor X, and the time course of factor X activation was determined. At a 1/250 dilution of rabbit brain thromboplastin, the rate of factor X activation in plasmas deficient in factor VIII or factor IX was 10% of the activation rate of normal plasma or of factor XI deficient plasma. Reconstitution of the deficient plasmas with factors VIII or IX, respectively, reconstituted normal factor X activation. Similar results were obtained when various dilutions of human thromboplastin replaced the rabbit thromboplastin. From these plasma experiments, it is inferred that the dilute thromboplastin-dependent activation of factor X requires factors VII, IX, and VIII. An alternative extrinsic pathway that involves factors IX and VIII may be the physiologic extrinsic pathway and hence help to explain the consistent clinical observations of bleeding diatheses in patients deficient in factors IX or VIII

  17. Structural basis of divergent cyclin-dependent kinase activation by Spy1/RINGO proteins

    Energy Technology Data Exchange (ETDEWEB)

    McGrath, Denise A.; Fifield, Bre-Anne; Marceau, Aimee H.; Tripathi, Sarvind; Porter, Lisa A.; Rubin, Seth M. (UCSC); (Windsor)

    2017-06-30

    Cyclin-dependent kinases (Cdks) are principal drivers of cell division and are an important therapeutic target to inhibit aberrant proliferation. Cdk enzymatic activity is tightly controlled through cyclin interactions, posttranslational modifications, and binding of inhibitors such as the p27 tumor suppressor protein. Spy1/RINGO (Spy1) proteins bind and activate Cdk but are resistant to canonical regulatory mechanisms that establish cell-cycle checkpoints. Cancer cells exploit Spy1 to stimulate proliferation through inappropriate activation of Cdks, yet the mechanism is unknown. We have determined crystal structures of the Cdk2-Spy1 and p27-Cdk2-Spy1 complexes that reveal how Spy1 activates Cdk. We find that Spy1 confers structural changes to Cdk2 that obviate the requirement of Cdk activation loop phosphorylation. Spy1 lacks the cyclin-binding site that mediates p27 and substrate affinity, explaining why Cdk-Spy1 is poorly inhibited by p27 and lacks specificity for substrates with cyclin-docking sites. We identify mutations in Spy1 that ablate its ability to activate Cdk2 and to proliferate cells. Our structural description of Spy1 provides important mechanistic insights that may be utilized for targeting upregulated Spy1 in cancer.

  18. Characteristics of seasonal variation and solar activity dependence of the geomagnetic solar quiet daily variation

    Science.gov (United States)

    Shinbori, A.; Koyama, Y.; Nose, M.; Hori, T.

    2017-12-01

    Characteristics of seasonal variation and solar activity dependence of the X- and Y-components of the geomagnetic solar quiet (Sq) daily variation at Memanbetsu in mid-latitudes and Guam near the equator have been investigated using long-term geomagnetic field data with 1-h time resolution from 1957 to 2016. In this analysis, we defined the quiet day when the maximum value of the Kp index is less than 3 for that day. In this analysis, we used the monthly average of the adjusted daily F10.7 corresponding to geomagnetically quiet days. For identification of the monthly mean Sq variation in the X and Y components (Sq-X and Sq-Y), we first determined the baseline of the X and Y components from the average value from 22 to 2 h (LT: local time) for each quiet day. Next, we calculated a deviation from the baseline of the X- and Y-components of the geomagnetic field for each quiet day, and computed the monthly mean value of the deviation for each local time. As a result, Sq-X and Sq-Y shows a clear seasonal variation and solar activity dependence. The amplitude of seasonal variation increases significantly during high solar activities, and is proportional to the solar F10.7 index. The pattern of the seasonal variation is quite different between Sq-X and Sq-Y. The result of the correlation analysis between the solar F10.7 index and Sq-X and Sq-Y shows almost the linear relationship, but the slope and intercept of the linear fitted line varies as function of local time and month. This implies that the sensitivity of Sq-X and Sq-Y to the solar activity is different for different local times and seasons. The local time dependence of the offset value of Sq-Y at Guam and its seasonal variation suggest a magnetic field produced by inter-hemispheric field-aligned currents (FACs). From the sign of the offset value of Sq-Y, it is infer that the inter-hemispheric FACs flow from the summer to winter hemispheres in the dawn and dusk sectors and from the winter to summer hemispheres in

  19. Aberrant regional brain activities in alcohol dependence: a functional magnetic resonance imaging study

    Directory of Open Access Journals (Sweden)

    Tu XZ

    2018-03-01

    Full Text Available Xianzhu Tu,1 Juanjuan Wang,2 Xuming Liu,3 Jiyong Zheng4 1Department of Psychiatry, Seventh People’s Hospital of Wenzhou City, Wenzhou, Zhejiang, People’s Republic of China; 2Department of Neurology, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People’s Republic of China; 3Department of Radiology, The Third Clinical Institute Affiliated to Wenzhou Medical University, Wenzhou, Zhejiang, People’s Republic of China; 4Department of Medical Imaging, The Affiliated Huai’an No 1 People’s Hospital of Nanjing Medical University, Huai’an, Jiangsu, People’s Republic of China Objective: Whether moderate alcohol consumption has health benefits remains controversial, but the harmful effects of excessive alcohol consumption on behavior and brain function are well recognized. The aim of this study was to investigate alcohol-induced regional brain activities and their relationships with behavioral factors. Subjects and methods: A total of 29 alcohol-dependent subjects (9 females and 20 males and 29 status-matched healthy controls (11 females and 18 males were recruited. Severity of alcohol dependence questionnaire (SADQ and alcohol use disorders identification test (AUDIT were used to evaluate the severity of alcohol craving. Regional homogeneity (ReHo analysis was used to explore the alcohol-induced regional brain changes. Receiver operating characteristic (ROC curve was used to investigate the ability of regional brain activities to distinguish alcohol-dependent subjects from healthy controls. Pearson correlations were used to investigate the relationships between alcohol-induced ReHo differences and behavioral factors. Results: Alcohol-dependent subjects related to healthy controls showed higher ReHo areas in the right superior frontal gyrus (SFG, bilateral medial frontal gyrus (MFG, left precentral gyrus (PG, bilateral middle temporal gyrus (MTG, and right inferior temporal gyrus (ITG and lower ReHo areas in

  20. Hepatitis C virus NS2 protein activates cellular cyclic AMP-dependent pathways

    International Nuclear Information System (INIS)

    Kim, Kyoung Mi; Kwon, Shi-Nae; Kang, Ju-Il; Lee, Song Hee; Jang, Sung Key; Ahn, Byung-Yoon; Kim, Yoon Ki

    2007-01-01

    Chronic infection of the hepatitis C virus (HCV) leads to liver cirrhosis and cancer. The mechanism leading to viral persistence and hepatocellular carcinoma, however, has not been fully understood. In this study, we show that the HCV infection activates cellular cAMP-dependent pathways. Expression of a luciferase reporter gene controlled by a basic promoter with the cAMP response element (CRE) was significantly elevated in human hepatoma Huh-7 cells infected with the HCV JFH1. Analysis with viral subgenomic replicons indicated that the HCV NS2 protein is responsible for the effect. Furthermore, the level of cellular transcripts whose stability is known to be regulated by cAMP was specifically reduced in cells harboring NS2-expressing replicons. These results allude to the HCV NS2 protein having a novel function of regulating cellular gene expression and proliferation through the cAMP-dependent pathway

  1. Collateral sensitivity between aminoglycosides and beta-lactam antibiotics depends on active proton pumps.

    Science.gov (United States)

    Azimi, Leila; Rastegar Lari, Abdolaziz

    2017-11-01

    Selection inversion is the hypothesis for antibiotic resistant inhabitation in bacteria and collateral sensitivity is one of the proposed phenomena for achievement of this hypothesis. The presence of collateral sensitivity associated with the proton motivation pump between the aminoglycosides and beta-lactam group of antibiotics is one of the examples of collateral sensitivity in some studies. The aim of this study was to demonstrate that collateral sensitivity between aminoglycosides and beta-lactam antibiotics associated with proton motivation pump may not be true in all cases. In this study, 100 Pseudomonas aeruginosa were surveyed. Gentamicin and imipenem-resistant strains were confirmed by disc diffusion method and MIC. Active proton motivation pumps were screened by pumps inhibitor. Semi-quantitative Real-Time PCR assay was used to confirm gene overexpression. Seventy-six and 79 out of 100 strains were resistant to gentamicin and imipenem, respectively. Seventy-five strains were resistant to both gentamicin and imipenem. The results of proton pump inhibitor test showed the involvement of active proton motivation pump in 22 of 75 imipenem- and gentamicin-resistant strains. According to Real - Time PCR assay, mexX efflux gene was overexpressed in the majority of isolates tested. The collateral sensitivity effect cannot explain the involvement of active proton motivation pumps in both imipenem and gentamicin-resistant strains simultaneously. Active and/or inactive proton pump in gentamicin-sensitive and/or resistant strains cannot be a suitable example for explanation of collateral sensitivity between aminoglycosides and beta-lactam antibiotics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Activity of Mn-Oxidizing Peroxidases of Ganoderma lucidum Depending on Cultivation Conditions

    Directory of Open Access Journals (Sweden)

    Jasmina Ćilerdžić

    2015-11-01

    Full Text Available Trunks and stumps of various deciduous species act as natural habitats for Ganoderma lucidum. The chemical composition of their cell wall affects the development of fungal ligninolytic enzyme system as well as its ability to degrade lignin from the plant cell wall. Additionally, numerous compounds structurally similar to lignin can be degraded by the G. lucidum enzyme system which could take important roles in various biotechnological processes. The laccases, which are the dominant enzymes synthesized by G. lucidum, have been studied more extensively than the Mn-oxidizing peroxidases. Therefore, this study aimed to create the dynamics profile of Mn-oxidizing peroxidases activities in four G. lucidum strains, classifying and determining their properties depending on the cultivation type and plant residue as a carbon source in the medium, as well as to establish whether intraspecific variety exists. The findings suggest that submerged cultivation appeared to be a more appropriate cultivation type for enzyme activities compared with solid-state cultivation, and oak sawdust was a better carbon source than wheat straw. Under the optimum conditions, on day 14, G. lucidum BEOFB 431 was characterized by the highest levels of both Mn-dependent and Mn-independent peroxidase activities (4795.5 and 5170.5 U/L, respectively. Strain, cultivation type, and carbon source were factors that affected the profiles of Mn-oxidizing peroxidases isoenzymes.

  3. Morphology-dependent activity of Pt nanocatalysts for ethanol oxidation in acidic media: Nanowires versus nanoparticles

    International Nuclear Information System (INIS)

    Zhou Weiping; Li Meng; Koenigsmann, Christopher; Ma Chao; Wong, Stanislaus S.; Adzic, Radoslav R.

    2011-01-01

    Highlights: → We demonstrate the morphology effect of Pt catalysts in electrooxidation of ethanol and CO in an acidic solution. → Pt nanowires and nanoparticles were used as catalysts. → Pt nanowires display a higher catalytic activity by a factor of at least two relative to those nanoparticles for ethanol oxidation. → The rate for CO monolayer oxidation exhibits similar morphology-dependent behavior with a markedly enhanced rate on the Pt nanowires. - Abstract: The morphology of nanostructured Pt catalysts is known to affect significantly the kinetics of various reactions. Herein, we report on a pronounced morphology effect in the electrooxidation of ethanol and carbon monoxide (CO) on Pt nanowires and nanoparticles in an acidic solution. The high resolution transmission electron microscopy analysis showed the inherent morphology difference between these two nanostructured catalysts. Voltammetric and chronoamperometric studies of the ethanol electrooxidation revealed that these nanowires had a higher catalytic activity by a factor of two relative to these nanoparticles. The rate for CO monolayer oxidation exhibits similar morphology-dependent behavior with a markedly enhanced rate on the Pt nanowires. In situ infrared reflection-absorption spectroscopy measurements revealed a different trend for chemisorbed CO formation and CO 2 -to-acetic acid reaction product ratios on these two nanostructures. The morphology-induced change in catalytic activity and selectivity in ethanol electrocatalysis is discussed in detail.

  4. Activity-dependent changes in excitability of perirhinal cortex networks in vitro.

    Science.gov (United States)

    Biagini, Giuseppe; D'Antuono, Margherita; Inaba, Yuji; Kano, Toshiyuki; Ragsdale, David; Avoli, Massimo

    2015-04-01

    Rat brain slices comprising the perirhinal cortex (PC) and a portion of the lateral nucleus of the amygdala (LA), in standard medium, can generate synchronous oscillatory activity that is associated with action potential discharge and reflects the activation of glutamatergic and GABAergic receptors. We report here that similar synchronous oscillatory events are recorded in the PC in response to single-shock, electrical stimuli delivered in LA. In addition, we found that the latency of these responses progressively increased when the stimulus interval was varied from 10 to 1 s; for example, the response latency during stimuli delivered at 1 Hz was more than twofold longer than that seen during stimulation at 0.1 Hz. This prolongation in latency occurred after approximately 5 stimuli, attained a steady value after 24-35 stimuli, and recovered to control values 30 s after stimulation arrest. These frequency-dependent changes in latency continued to occur during NMDA receptor antagonism but weakened following application of GABAA and/or GABAB receptor blockers. Our findings identify a new type of short-term plasticity that is mediated by GABA receptor function and may play a role in decreasing neuronal network synchronization during repeated activation. We propose that this frequency-dependent adaptive mechanism influences the excitability of limbic networks, thus potentially controlling epileptiform synchronization.

  5. Activation of cGAS-dependent antiviral responses by DNA intercalating agents.

    Science.gov (United States)

    Pépin, Geneviève; Nejad, Charlotte; Thomas, Belinda J; Ferrand, Jonathan; McArthur, Kate; Bardin, Philip G; Williams, Bryan R G; Gantier, Michael P

    2017-01-09

    Acridine dyes, including proflavine and acriflavine, were commonly used as antiseptics before the advent of penicillins in the mid-1940s. While their mode of action on pathogens was originally attributed to their DNA intercalating activity, work in the early 1970s suggested involvement of the host immune responses, characterized by induction of interferon (IFN)-like activities through an unknown mechanism. We demonstrate here that sub-toxic concentrations of a mixture of acriflavine and proflavine instigate a cyclic-GMP-AMP (cGAMP) synthase (cGAS)-dependent type-I IFN antiviral response. This pertains to the capacity of these compounds to induce low level DNA damage and cytoplasmic DNA leakage, resulting in cGAS-dependent cGAMP-like activity. Critically, acriflavine:proflavine pre-treatment of human primary bronchial epithelial cells significantly reduced rhinovirus infection. Collectively, our findings constitute the first evidence that non-toxic DNA binding agents have the capacity to act as indirect agonists of cGAS, to exert potent antiviral effects in mammalian cells. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  6. Activity-Dependent Plasticity of Spike Pauses in Cerebellar Purkinje Cells

    Directory of Open Access Journals (Sweden)

    Giorgio Grasselli

    2016-03-01

    Full Text Available The plasticity of intrinsic excitability has been described in several types of neurons, but the significance of non-synaptic mechanisms in brain plasticity and learning remains elusive. Cerebellar Purkinje cells are inhibitory neurons that spontaneously fire action potentials at high frequencies and regulate activity in their target cells in the cerebellar nuclei by generating a characteristic spike burst-pause sequence upon synaptic activation. Using patch-clamp recordings from mouse Purkinje cells, we find that depolarization-triggered intrinsic plasticity enhances spike firing and shortens the duration of spike pauses. Pause plasticity is absent from mice lacking SK2-type potassium channels (SK2−/− mice and in occlusion experiments using the SK channel blocker apamin, while apamin wash-in mimics pause reduction. Our findings demonstrate that spike pauses can be regulated through an activity-dependent, exclusively non-synaptic, SK2 channel-dependent mechanism and suggest that pause plasticity—by altering the Purkinje cell output—may be crucial to cerebellar information storage and learning.

  7. Memory and pattern storage in neural networks with activity dependent synapses

    Science.gov (United States)

    Mejias, J. F.; Torres, J. J.

    2009-01-01

    We present recently obtained results on the influence of the interplay between several activity dependent synaptic mechanisms, such as short-term depression and facilitation, on the maximum memory storage capacity in an attractor neural network [1]. In contrast with the case of synaptic depression, which drastically reduces the capacity of the network to store and retrieve activity patterns [2], synaptic facilitation is able to enhance the memory capacity in different situations. In particular, we find that a convenient balance between depression and facilitation can enhance the memory capacity, reaching maximal values similar to those obtained with static synapses, that is, without activity-dependent processes. We also argue, employing simple arguments, that this level of balance is compatible with experimental data recorded from some cortical areas, where depression and facilitation may play an important role for both memory-oriented tasks and information processing. We conclude that depressing synapses with a certain level of facilitation allow to recover the good retrieval properties of networks with static synapses while maintaining the nonlinear properties of dynamic synapses, convenient for information processing and coding.

  8. Morphology-dependent activity of Pt nanocatalysts for ethanol oxidation in acidic media: Nanowires versus nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Weiping, E-mail: wpzhou@bnl.gov [Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Li Meng [Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Koenigsmann, Christopher [Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794 (United States); Ma Chao [Condensed Matter Physics and Materials Sciences Department, Brookhaven National Laboratory, Building 480, Upton, NY 11973 (United States); Wong, Stanislaus S. [Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794 (United States); Condensed Matter Physics and Materials Sciences Department, Brookhaven National Laboratory, Building 480, Upton, NY 11973 (United States); Adzic, Radoslav R. [Chemistry Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2011-11-30

    Highlights: > We demonstrate the morphology effect of Pt catalysts in electrooxidation of ethanol and CO in an acidic solution. > Pt nanowires and nanoparticles were used as catalysts. > Pt nanowires display a higher catalytic activity by a factor of at least two relative to those nanoparticles for ethanol oxidation. > The rate for CO monolayer oxidation exhibits similar morphology-dependent behavior with a markedly enhanced rate on the Pt nanowires. - Abstract: The morphology of nanostructured Pt catalysts is known to affect significantly the kinetics of various reactions. Herein, we report on a pronounced morphology effect in the electrooxidation of ethanol and carbon monoxide (CO) on Pt nanowires and nanoparticles in an acidic solution. The high resolution transmission electron microscopy analysis showed the inherent morphology difference between these two nanostructured catalysts. Voltammetric and chronoamperometric studies of the ethanol electrooxidation revealed that these nanowires had a higher catalytic activity by a factor of two relative to these nanoparticles. The rate for CO monolayer oxidation exhibits similar morphology-dependent behavior with a markedly enhanced rate on the Pt nanowires. In situ infrared reflection-absorption spectroscopy measurements revealed a different trend for chemisorbed CO formation and CO{sub 2}-to-acetic acid reaction product ratios on these two nanostructures. The morphology-induced change in catalytic activity and selectivity in ethanol electrocatalysis is discussed in detail.

  9. Nucleolus-derived mediators in oncogenic stress response and activation of p53-dependent pathways.

    Science.gov (United States)

    Stępiński, Dariusz

    2016-08-01

    Rapid growth and division of cells, including tumor ones, is correlated with intensive protein biosynthesis. The output of nucleoli, organelles where translational machineries are formed, depends on a rate of particular stages of ribosome production and on accessibility of elements crucial for their effective functioning, including substrates, enzymes as well as energy resources. Different factors that induce cellular stress also often lead to nucleolar dysfunction which results in ribosome biogenesis impairment. Such nucleolar disorders, called nucleolar or ribosomal stress, usually affect cellular functioning which in fact is a result of p53-dependent pathway activation, elicited as a response to stress. These pathways direct cells to new destinations such as cell cycle arrest, damage repair, differentiation, autophagy, programmed cell death or aging. In the case of impaired nucleolar functioning, nucleolar and ribosomal proteins mediate activation of the p53 pathways. They are also triggered as a response to oncogenic factor overexpression to protect tissues and organs against extensive proliferation of abnormal cells. Intentional impairment of any step of ribosome biosynthesis which would direct the cells to these destinations could be a strategy used in anticancer therapy. This review presents current knowledge on a nucleolus, mainly in relation to cancer biology, which is an important and extremely sensitive element of the mechanism participating in cellular stress reaction mediating activation of the p53 pathways in order to counteract stress effects, especially cancer development.

  10. Activity-dependent astrocyte swelling is mediated by pH-regulating mechanisms.

    Science.gov (United States)

    Larsen, Brian Roland; MacAulay, Nanna

    2017-10-01

    During neuronal activity in the mammalian brain, the K + released into the synaptic space is initially buffered by the astrocytic compartment. In parallel, the extracellular space (ECS) shrinks, presumably due to astrocytic cell swelling. With the Na + /K + /2Cl - cotransporter and the Kir4.1/AQP4 complex not required for the astrocytic cell swelling in the hippocampus, the molecular mechanisms underlying the activity-dependent ECS shrinkage have remained unresolved. To identify these molecular mechanisms, we employed ion-sensitive microelectrodes to measure changes in ECS, [K + ] o and [H + ] o /pH o during electrical stimulation of rat hippocampal slices. Transporters and receptors responding directly to the K + and glutamate released into the extracellular space (the K + /Cl - cotransporter, KCC, glutamate transporters and G protein-coupled receptors) did not modulate the extracellular space dynamics. The HCO3--transporting mechanism, which in astrocytes mainly constitutes the electrogenic Na + / HCO3- cotransporter 1 (NBCe1), is activated by the K + -mediated depolarization of the astrocytic membrane. Inhibition of this transporter reduced the ECS shrinkage by ∼25% without affecting the K + transients, pointing to NBCe1 as a key contributor to the stimulus-induced astrocytic cell swelling. Inhibition of the monocarboxylate cotransporters (MCT), like-wise, reduced the ECS shrinkage by ∼25% without compromising the K + transients. Isosmotic reduction of extracellular Cl - revealed a requirement for this ion in parts of the ECS shrinkage. Taken together, the stimulus-evoked astrocytic cell swelling does not appear to occur as a direct effect of the K + clearance, as earlier proposed, but partly via the pH-regulating transport mechanisms activated by the K + -induced astrocytic depolarization and the activity-dependent metabolism. © 2017 Wiley Periodicals, Inc.

  11. Hydrogen peroxide induces activation of insulin signaling pathway via AMP-dependent kinase in podocytes

    International Nuclear Information System (INIS)

    Piwkowska, Agnieszka; Rogacka, Dorota; Angielski, Stefan; Jankowski, Maciej

    2012-01-01

    Highlights: ► H 2 O 2 activates the insulin signaling pathway and glucose uptake in podocytes. ► H 2 O 2 induces time-dependent changes in AMPK phosphorylation. ► H 2 O 2 enhances insulin signaling pathways via AMPK activation. ► H 2 O 2 stimulation of glucose uptake is AMPK-dependent. -- Abstract: Podocytes are cells that form the glomerular filtration barrier in the kidney. Insulin signaling in podocytes is critical for normal kidney function. Insulin signaling is regulated by oxidative stress and intracellular energy levels. We cultured rat podocytes to investigate the effects of hydrogen peroxide (H 2 O 2 ) on the phosphorylation of proximal and distal elements of insulin signaling. We also investigated H 2 O 2 -induced intracellular changes in the distribution of protein kinase B (Akt). Western blots showed that H 2 O 2 (100 μM) induced rapid, transient phosphorylation of the insulin receptor (IR), the IR substrate-1 (IRS1), and Akt with peak activities at 5 min (Δ 183%, P 2 O 2 >. Furthermore, H 2 O 2 inhibited phosphorylation of the phosphatase and tensin homologue (PTEN; peak activity at 10 min; Δ −32%, P 2 O 2 on IR phosphorylation by about 40% (from 2.07 ± 0.28 to 1.28 ± 0.12, P 2 O 2 increased glucose uptake in podocytes (from 0.88 ± 0.04 to 1.29 ± 0.12 nmol/min/mg protein, P 2 O 2 activated the insulin signaling pathway and glucose uptake via AMPK in cultured rat podocytes. This signaling may play a potential role in the prevention of insulin resistance under conditions associated with oxidative stress.

  12. Development of quantitative structure activity relationship (QSAR) model for disinfection byproduct (DBP) research: A review of methods and resources

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Baiyang, E-mail: poplar_chen@hotmail.com [Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055 (China); Zhang, Tian [Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055 (China); Bond, Tom [Department of Civil and Environmental Engineering, Imperial College, London SW7 2AZ (United Kingdom); Gan, Yiqun [Harbin Institute of Technology Shenzhen Graduate School, Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Shenzhen 518055 (China)

    2015-12-15

    Quantitative structure–activity relationship (QSAR) models are tools for linking chemical activities with molecular structures and compositions. Due to the concern about the proliferating number of disinfection byproducts (DBPs) in water and the associated financial and technical burden, researchers have recently begun to develop QSAR models to investigate the toxicity, formation, property, and removal of DBPs. However, there are no standard procedures or best practices regarding how to develop QSAR models, which potentially limit their wide acceptance. In order to facilitate more frequent use of QSAR models in future DBP research, this article reviews the processes required for QSAR model development, summarizes recent trends in QSAR-DBP studies, and shares some important resources for QSAR development (e.g., free databases and QSAR programs). The paper follows the four steps of QSAR model development, i.e., data collection, descriptor filtration, algorithm selection, and model validation; and finishes by highlighting several research needs. Because QSAR models may have an important role in progressing our understanding of DBP issues, it is hoped that this paper will encourage their future use for this application.

  13. Development of quantitative structure activity relationship (QSAR) model for disinfection byproduct (DBP) research: A review of methods and resources

    International Nuclear Information System (INIS)

    Chen, Baiyang; Zhang, Tian; Bond, Tom; Gan, Yiqun

    2015-01-01

    Quantitative structure–activity relationship (QSAR) models are tools for linking chemical activities with molecular structures and compositions. Due to the concern about the proliferating number of disinfection byproducts (DBPs) in water and the associated financial and technical burden, researchers have recently begun to develop QSAR models to investigate the toxicity, formation, property, and removal of DBPs. However, there are no standard procedures or best practices regarding how to develop QSAR models, which potentially limit their wide acceptance. In order to facilitate more frequent use of QSAR models in future DBP research, this article reviews the processes required for QSAR model development, summarizes recent trends in QSAR-DBP studies, and shares some important resources for QSAR development (e.g., free databases and QSAR programs). The paper follows the four steps of QSAR model development, i.e., data collection, descriptor filtration, algorithm selection, and model validation; and finishes by highlighting several research needs. Because QSAR models may have an important role in progressing our understanding of DBP issues, it is hoped that this paper will encourage their future use for this application.

  14. Hormonal regulation of Na+/K+-dependent ATPase activity and pump function in corneal endothelial cells.

    Science.gov (United States)

    Hatou, Shin

    2011-10-01

    Na- and K-dependent ATPase (Na,K-ATPase) in the basolateral membrane of corneal endothelial cells plays an important role in the pump function of the corneal endothelium. We investigated the role of dexamethasone in the regulation of Na,K-ATPase activity and pump function in these cells. Mouse corneal endothelial cells were exposed to dexamethasone or insulin. ATPase activity was evaluated by spectrophotometric measurement, and pump function was measured using an Ussing chamber. Western blotting and immunocytochemistry were performed to measure the expression of the Na,K-ATPase α1-subunit. Dexamethasone increased Na,K-ATPase activity and the pump function of endothelial cells. Western blot analysis indicated that dexamethasone increased the expression of the Na,K-ATPase α1-subunit but decreased the ratio of active to inactive Na,K-ATPase α1-subunit. Insulin increased Na,K-ATPase activity and pump function of cultured corneal endothelial cells. These effects were transient and blocked by protein kinase C inhibitors and inhibitors of protein phosphatases 1 (PP1) and 2A (PP2A). Western blot analysis indicated that insulin decreased the amount of inactive Na,K-ATPase α1-subunit, but the expression of total Na,K-ATPase α1-subunit was unchanged. Immunocytochemistry showed that insulin increased cell surface expression of the Na,K-ATPase α1-subunit. Our results suggest that dexamethasone and insulin stimulate Na,K-ATPase activity in mouse corneal endothelial cells. The effect of dexamethasone activation in these cells was mediated by Na,K-ATPase synthesis and an increased enzymatic activity because of dephosphorylation of Na,K-ATPase α1-subunits. The effect of insulin is mediated by the protein kinase C, PP1, and/or PP2A pathways.

  15. Protein kinase activity of phosphoinositide 3-kinase regulates cytokine-dependent cell survival.

    Directory of Open Access Journals (Sweden)

    Daniel Thomas

    Full Text Available The dual specificity protein/lipid kinase, phosphoinositide 3-kinase (PI3K, promotes growth factor-mediated cell survival and is frequently deregulated in cancer. However, in contrast to canonical lipid-kinase functions, the role of PI3K protein kinase activity in regulating cell survival is unknown. We have employed a novel approach to purify and pharmacologically profile protein kinases from primary human acute myeloid leukemia (AML cells that phosphorylate serine residues in the cytoplasmic portion of cytokine receptors to promote hemopoietic cell survival. We have isolated a kinase activity that is able to directly phosphorylate Ser585 in the cytoplasmic domain of the interleukin 3 (IL-3 and granulocyte macrophage colony stimulating factor (GM-CSF receptors and shown it to be PI3K. Physiological concentrations of cytokine in the picomolar range were sufficient for activating the protein kinase activity of PI3K leading to Ser585 phosphorylation and hemopoietic cell survival but did not activate PI3K lipid kinase signaling or promote proliferation. Blockade of PI3K lipid signaling by expression of the pleckstrin homology of Akt1 had no significant impact on the ability of picomolar concentrations of cytokine to promote hemopoietic cell survival. Furthermore, inducible expression of a mutant form of PI3K that is defective in lipid kinase activity but retains protein kinase activity was able to promote Ser585 phosphorylation and hemopoietic cell survival in the absence of cytokine. Blockade of p110α by RNA interference or multiple independent PI3K inhibitors not only blocked Ser585 phosphorylation in cytokine-dependent cells and primary human AML blasts, but also resulted in a block in survival signaling and cell death. Our findings demonstrate a new role for the protein kinase activity of PI3K in phosphorylating the cytoplasmic tail of the GM-CSF and IL-3 receptors to selectively regulate cell survival highlighting the importance of targeting

  16. Comparative study on the dependence of quantitative results in the electron microscopic autoradiography on the type of developer (Microdol X, Phenidon)

    International Nuclear Information System (INIS)

    David, H.; Marx, I.; Nanoff, S.

    1978-01-01

    It was the aim of the investigation to compare quantitative results of electron microscopic autoradiographs after the use of different developers (Microdol X, Phenidon) adapting morphometrical methods. Erythroblasts of rabbit were tested after incorporation of 3 H-uridine in vitro. Both developers showed the same tendency at higher rates of incorporation (basophilic erythroblasts and polychromatic erythroblasts). Using Phenidon, however, we could obtain only half the values for the individual cell components. At high rates of incorporation Microdol X results in an overlapping of the silver filaments. Thus, more distinct grains can be reached by Phenidon. At smaller rates of incorporation (orthochromatic erythroblasts) after using. Phenidon a quantitative evaluation is however influenced by too many factors of uncertainty so that according to our investigations Microdol X is better suited for a quantitative evaluation of electron microscopic autoradiographs. (author)

  17. Early survival factor deprivation in the olfactory epithelium enhances activity-dependent survival

    Directory of Open Access Journals (Sweden)

    Adrien eFrançois

    2013-12-01

    Full Text Available The neuronal olfactory epithelium undergoes permanent renewal because of environmental aggression. This renewal is partly regulated by factors modulating the level of neuronal apoptosis. Among them, we had previously characterized endothelin as neuroprotective. In this study, we explored the effect of cell survival factor deprivation in the olfactory epithelium by intranasal delivery of endothelin receptors antagonists to rat pups. This treatment induced an overall increase of apoptosis in the olfactory epithelium. The responses to odorants recorded by electroolfactogram were decreased in treated animal, a result consistent with a loss of olfactory sensory neurons (OSNs. However, the treated animal performed better in an olfactory orientation test based on maternal odor compared to non-treated littermates. This improved performance could be due to activity-dependent neuronal survival of OSNs in the context of increased apoptosis level. In order to demonstrate it, we odorized pups with octanal, a known ligand for the rI7 olfactory receptor (Olr226. We quantified the number of OSN expressing rI7 by RT-qPCR and whole mount in situ hybridization. While this number was reduced by the survival factor removal treatment, this reduction was abolished by the presence of its ligand. This improved survival was optimal for low concentration of odorant and was specific for rI7-expressing OSNs. Meanwhile, the number of rI7-expressing OSNs was not affected by the odorization in non-treated littermates; showing that the activity-dependant survival of OSNs did not affect the OSN population during the 10 days of odorization in control conditions. Overall, our study shows that when apoptosis is promoted in the olfactory mucosa, the activity-dependent neuronal plasticity allows faster tuning of the olfactory sensory neuron population towards detection of environmental odorants.

  18. Transcriptional activation of NAD+-dependent protein deacetylase SIRT1 by nuclear receptor TLX.

    Science.gov (United States)

    Iwahara, Naotoshi; Hisahara, Shin; Hayashi, Takashi; Horio, Yoshiyuki

    2009-09-04

    An orphan nuclear receptor TLX is a transcriptional repressor that promotes the proliferation and self-renewal of neural precursor cells (NPCs). SIRT1, an NAD(+)-dependent protein deacetylase, is highly expressed in the NPCs and participates in neurogenesis. Here, we found that TLX colocalized with SIRT1 and knockdown of TLX by small interfering RNAs decreased SIRT1 levels in NPCs. TLX increased the SIRT1 expression by binding to the newly identified TLX-activating element in the SIRT1 gene promoter in HEK293 cells. Thus, TLX is an inducer of SIRT1 and may contribute to neurogenesis both as a transactivator and as a repressor.

  19. Transcriptional activation of NAD+-dependent protein deacetylase SIRT1 by nuclear receptor TLX

    International Nuclear Information System (INIS)

    Iwahara, Naotoshi; Hisahara, Shin; Hayashi, Takashi; Horio, Yoshiyuki

    2009-01-01

    An orphan nuclear receptor TLX is a transcriptional repressor that promotes the proliferation and self-renewal of neural precursor cells (NPCs). SIRT1, an NAD + -dependent protein deacetylase, is highly expressed in the NPCs and participates in neurogenesis. Here, we found that TLX colocalized with SIRT1 and knockdown of TLX by small interfering RNAs decreased SIRT1 levels in NPCs. TLX increased the SIRT1 expression by binding to the newly identified TLX-activating element in the SIRT1 gene promoter in HEK293 cells. Thus, TLX is an inducer of SIRT1 and may contribute to neurogenesis both as a transactivator and as a repressor.

  20. Intracellular invasion of Orientia tsutsugamushi activates inflammasome in asc-dependent manner.

    Directory of Open Access Journals (Sweden)

    Jung-Eun Koo

    Full Text Available Orientia tsutsugamushi, a causative agent of scrub typhus, is an obligate intracellular bacterium, which escapes from the endo/phagosome and replicates in the host cytoplasm. O. tsutsugamushi infection induces production of pro-inflammatory mediators including interleukin-1β (IL-1β, which is secreted mainly from macrophages upon cytosolic stimuli by activating cysteine protease caspase-1 within a complex called the inflammasome, and is a key player in initiating and maintaining the inflammatory response. However, the mechanism for IL-1β maturation upon O. tsutsugamushi infection has not been identified. In this study, we show that IL-1 receptor signaling is required for efficient host protection from O. tsutsugamushi infection. Live Orientia, but not heat- or UV-inactivated Orientia, activates the inflammasome through active bacterial uptake and endo/phagosomal maturation. Furthermore, Orientia-stimulated secretion of IL-1β and activation of caspase-1 are ASC- and caspase-1- dependent since IL-1β production was impaired in Asc- and caspase-1-deficient macrophages but not in Nlrp3-, Nlrc4- and Aim2-deficient macrophages. Therefore, live O. tsutsugamushi triggers ASC inflammasome activation leading to IL-1β production, which is a critical innate immune response for effective host defense.

  1. Genetically encoded proton sensors reveal activity-dependent pH changes in neurons

    Directory of Open Access Journals (Sweden)

    Joseph Valentino Raimondo

    2012-05-01

    Full Text Available The regulation of hydrogen ion concentration (pH is fundamental to cell viability, metabolism and enzymatic function. Within the nervous system, the control of pH is also involved in diverse and dynamic processes including development, synaptic transmission and the control of network excitability. As pH affects neuronal activity, and can also itself be altered by neuronal activity, the existence of tools to accurately measure hydrogen ion fluctuations is important for understanding the role pH plays under physiological and pathological conditions. Outside of their use as a marker of synaptic release, genetically encoded pH sensors have not been utilised to study hydrogen ion fluxes associated with network activity. By combining whole-cell patch clamp with simultaneous two-photon or confocal imaging, we quantified the amplitude and time course of neuronal, intracellular, acidic transients evoked by epileptiform activity in two separate in vitro models of temporal lobe epilepsy. In doing so, we demonstrate the suitability of three genetically encoded pH sensors: deGFP4, E2GFP and Cl-sensor for investigating activity-dependent pH changes at the level of single neurons.

  2. Genetically encoded proton sensors reveal activity-dependent pH changes in neurons.

    Science.gov (United States)

    Raimondo, Joseph V; Irkle, Agnese; Wefelmeyer, Winnie; Newey, Sarah E; Akerman, Colin J

    2012-01-01

    The regulation of hydrogen ion concentration (pH) is fundamental to cell viability, metabolism, and enzymatic function. Within the nervous system, the control of pH is also involved in diverse and dynamic processes including development, synaptic transmission, and the control of network excitability. As pH affects neuronal activity, and can also itself be altered by neuronal activity, the existence of tools to accurately measure hydrogen ion fluctuations is important for understanding the role pH plays under physiological and pathological conditions. Outside of their use as a marker of synaptic release, genetically encoded pH sensors have not been utilized to study hydrogen ion fluxes associated with network activity. By combining whole-cell patch clamp with simultaneous two-photon or confocal imaging, we quantified the amplitude and time course of neuronal, intracellular, acidic transients evoked by epileptiform activity in two separate in vitro models of temporal lobe epilepsy. In doing so, we demonstrate the suitability of three genetically encoded pH sensors: deGFP4, E(2)GFP, and Cl-sensor for investigating activity-dependent pH changes at the level of single neurons.

  3. A Novel Time-Dependent CENP-E Inhibitor with Potent Antitumor Activity.

    Directory of Open Access Journals (Sweden)

    Akihiro Ohashi

    Full Text Available Centromere-associated protein E (CENP-E regulates both chromosome congression and the spindle assembly checkpoint (SAC during mitosis. The loss of CENP-E function causes chromosome misalignment, leading to SAC activation and apoptosis during prolonged mitotic arrest. Here, we describe the biological and antiproliferative activities of a novel small-molecule inhibitor of CENP-E, Compound-A (Cmpd-A. Cmpd-A inhibits the ATPase activity of the CENP-E motor domain, acting as a time-dependent inhibitor with an ATP-competitive-like behavior. Cmpd-A causes chromosome misalignment on the metaphase plate, leading to prolonged mitotic arrest. Treatment with Cmpd-A induces antiproliferation in multiple cancer cell lines. Furthermore, Cmpd-A exhibits antitumor activity in a nude mouse xenograft model, and this antitumor activity is accompanied by the elevation of phosphohistone H3 levels in tumors. These findings demonstrate the potency of the CENP-E inhibitor Cmpd-A and its potential as an anticancer therapeutic agent.

  4. Regulation of KV channel voltage-dependent activation by transmembrane β subunits

    Directory of Open Access Journals (Sweden)

    Xiaohui eSun

    2012-04-01

    Full Text Available Voltage-activated K+ (KV channels are important for shaping action potentials and maintaining resting membrane potential in excitable cells. KV channels contain a central pore-gate domain (PGD surrounded by four voltage-sensing domains (VSD. The VSDs will change conformation in response to alterations of the membrane potential thereby inducing the opening of the PGD. Many KV channels are heteromeric protein complexes containing auxiliary β subunits. These β subunits modulate channel expression and activity to increase functional diversity and render tissue specific phenotypes. This review focuses on the KV β subunits that contain transmembrane (TM segments including the KCNE family and the β subunits of large conductance, Ca2+- and voltage-activated K+ (BK channels. These TM β subunits affect the voltage-dependent activation of KV α subunits. Experimental and computational studies have described the structural location of these β subunits in the channel complexes and the biophysical effects on VSD activation, PGD opening and VSD-PGD coupling. These results reveal some common characteristics and mechanistic insights into KV channel modulation by TM β subunits.

  5. Wise, a context-dependent activator and inhibitor of Wnt signalling.

    Science.gov (United States)

    Itasaki, Nobue; Jones, C Michael; Mercurio, Sara; Rowe, Alison; Domingos, Pedro M; Smith, James C; Krumlauf, Robb

    2003-09-01

    We have isolated a novel secreted molecule, Wise, by a functional screen for activities that alter the anteroposterior character of neuralised Xenopus animal caps. Wise encodes a secreted protein capable of inducing posterior neural markers at a distance. Phenotypes arising from ectopic expression or depletion of Wise resemble those obtained when Wnt signalling is altered. In animal cap assays, posterior neural markers can be induced by Wnt family members, and induction of these markers by Wise requires components of the canonical Wnt pathway. This indicates that in this context Wise activates the Wnt signalling cascade by mimicking some of the effects of Wnt ligands. Activation of the pathway was further confirmed by nuclear accumulation of beta-catenin driven by Wise. By contrast, in an assay for secondary axis induction, extracellularly Wise antagonises the axis-inducing ability of Wnt8. Thus, Wise can activate or inhibit Wnt signalling in a context-dependent manner. The Wise protein physically interacts with the Wnt co-receptor, lipoprotein receptor-related protein 6 (LRP6), and is able to compete with Wnt8 for binding to LRP6. These activities of Wise provide a new mechanism for integrating inputs through the Wnt coreceptor complex to modulate the balance of Wnt signalling.

  6. Activation of endoplasmic reticulum calcium leak by 2-APB depends on the luminal calcium concentration.

    Science.gov (United States)

    Leon-Aparicio, Daniel; Chavez-Reyes, Jesus; Guerrero-Hernandez, Agustin

    2017-07-01

    It has been shown that 2-APB is a nonspecific modulator of ion channel activity, while most of the channels are inhibited by this compound, there are few examples of channels that are activated by 2-APB. Additionally, it has been shown that, 2-APB leads to a reduction in the luminal endoplasmic reticulum Ca 2+ level ([Ca 2+ ] ER ) and we have carried out simultaneous recordings of both [Ca 2+ ] i and the [Ca 2+ ] ER in HeLa cell suspensions to assess the mechanism involved in this effect. This approach allowed us to determine that 2-APB induces a reduction in the [Ca 2+ ] ER by activating an ER-resident Ca 2+ permeable channel more than by inhibiting the activity of SERCA pumps. Interestingly, this effect of 2-APB of reducing the [Ca 2+ ] ER is auto-limited because depends on a replete ER Ca 2+ store; a condition that thapsigargin does not require to decrease the [Ca 2+ ] ER . Additionally, our data indicate that the ER Ca 2+ permeable channel activated by 2-APB does not seem to participate in the ER Ca 2+ leak revealed by inhibiting SERCA pump with thapsigargin. This work suggests that, prolonged incubations with even low concentrations of 2-APB (5μM) would lead to the reduction in the [Ca 2+ ] ER that might explain the inhibitory effect of this compound on those signals that require Ca 2+ release from the ER store. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Activity-Dependent Exocytosis of Lysosomes Regulates the Structural Plasticity of Dendritic Spines.

    Science.gov (United States)

    Padamsey, Zahid; McGuinness, Lindsay; Bardo, Scott J; Reinhart, Marcia; Tong, Rudi; Hedegaard, Anne; Hart, Michael L; Emptage, Nigel J

    2017-01-04

    Lysosomes have traditionally been viewed as degradative organelles, although a growing body of evidence suggests that they can function as Ca 2+ stores. Here we examined the function of these stores in hippocampal pyramidal neurons. We found that back-propagating action potentials (bpAPs) could elicit Ca 2+ release from lysosomes in the dendrites. This Ca 2+ release triggered the fusion of lysosomes with the plasma membrane, resulting in the release of Cathepsin B. Cathepsin B increased the activity of matrix metalloproteinase 9 (MMP-9), an enzyme involved in extracellular matrix (ECM) remodelling and synaptic plasticity. Inhibition of either lysosomal Ca 2+ signaling or Cathepsin B release prevented the maintenance of dendritic spine growth induced by Hebbian activity. This impairment could be rescued by exogenous application of active MMP-9. Our findings suggest that activity-dependent exocytosis of Cathepsin B from lysosomes regulates the long-term structural plasticity of dendritic spines by triggering MMP-9 activation and ECM remodelling. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

  8. Impaired Na⁺-dependent regulation of acetylcholine-activated inward-rectifier K⁺ current modulates action potential rate dependence in patients with chronic atrial fibrillation.

    Science.gov (United States)

    Voigt, Niels; Heijman, Jordi; Trausch, Anne; Mintert-Jancke, Elisa; Pott, Lutz; Ravens, Ursula; Dobrev, Dobromir

    2013-08-01

    Shortened action-potential duration (APD) and blunted APD rate adaptation are hallmarks of chronic atrial fibrillation (cAF). Basal and muscarinic (M)-receptor-activated inward-rectifier K(+) currents (IK1 and IK,ACh, respectively) contribute to regulation of human atrial APD and are subject to cAF-dependent remodeling. Intracellular Na(+) ([Na(+)]i) enhances IK,ACh in experimental models but the effect of [Na(+)]i-dependent regulation of inward-rectifier K(+) currents on APD in human atrial myocytes is currently unknown. Here, we report a [Na(+)]i-dependent inhibition of outward IK1 in atrial myocytes from sinus rhythm (SR) or cAF patients. In contrast, IK,ACh activated by carbachol, a non-selective M-receptor agonist, increased with elevation of [Na(+)]i in SR. This [Na(+)]i-dependent IK,ACh regulation was absent in cAF. Including [Na(+)]i dependence of IK1 and IK,ACh in a recent computational model of the human atrial myocyte revealed that [Na(+)]i accumulation at fast rates inhibits IK1 and blunts physiological APD rate dependence in both groups. [Na(+)]i-dependent IK,ACh augmentation at fast rates increased APD rate dependence in SR, but not in cAF. These results identify impaired Na(+)-sensitivity of IK,ACh as one potential mechanism contributing to the blunted APD rate dependence in patients with cAF. This article is part of a Special Issue entitled "Na(+) Regulation in Cardiac Myocytes". Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. A Quantitative Assessment of the Morphofunctional Activity of the Population of Mast Cells Exposed to Biotechnological Strains of Microorganisms

    Directory of Open Access Journals (Sweden)

    Natalia Sheina

    2018-06-01

    Full Text Available In order to assess the sensitizing properties of bacteria, micromycetes and actinomycetes, the morphofunctional activity of the population of mast cells was tested in rats exposed to biotechnological microorganisms. The result showed the high informative value of the test of peritoneal must cell degranulation. Both the result and the intensity of the response of mast cells to the exposure to the tested strains depend on the taxonomy of microorganisms, their concentration and the mode of inoculation. The test of peritoneal must cell degranulation can be recommended for assessing the biological safety of industrial microorganisms.

  10. Regional Brain Activity in Abstinent Methamphetamine Dependent Males Following Cue Exposure.

    Science.gov (United States)

    Malcolm, Robert; Myrick, Hugh; Li, Xingbao; Henderson, Scott; Brady, Kathleen T; George, Mark S; See, Ronald E

    Neuroimaging of drug-associated cue presentations has aided in understanding the neurobiological substrates of craving and relapse for cocaine, alcohol, and nicotine. However, imaging of cue-reactivity in methamphetamine addiction has been much less studied. Nine caucasian male methamphetamine-dependent subjects and nine healthy controls were scanned in a Phillips 3.0T MRI scan when they viewed a randomized presentation of visual cues of methamphetamine, neutral objects, and rest conditions. Functional Imaging data were analyzed with Statistical Parametric Mapping software 5 (SPM 5). Methamphetamine subjects had significant brain activation in the ventral striatum and medial frontal cortex in comparison to meth pictures and neutral pictures in healthy controls (pcues, have increased brain activity in ventral striatum, caudate nucleus and medial frontal cortex which subserve craving, drug-seeking, and drug use.