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Terms modified by MPa Selected AbstractsReduced metabolites mediate neuroprotective effects of progesterone in the adult rat hippocampus.DEVELOPMENTAL NEUROBIOLOGY, Issue 9 2006The synthetic progestin medroxyprogesterone acetate (Provera) is not neuroprotective Abstract The ovarian hormone progesterone is neuroprotective in different experimental models of neurodegeneration. In the nervous system, progesterone is metabolized to 5,-dihydroprogesterone (DHP) by the enzyme 5,-reductase. DHP is subsequently reduced to 3,,5,-tetrahydroprogesterone (THP) by a reversible reaction catalyzed by the enzyme 3,-hydroxysteroid dehydrogenase. In this study we have analyzed whether progesterone metabolism is involved in the neuroprotective effect of the hormone in the hilus of the hippocampus of ovariectomized rats injected with kainic acid, an experimental model of excitotoxic cell death. Progesterone increased the levels of DHP and THP in plasma and hippocampus and prevented kainic-acid-induced neuronal loss. In contrast to progesterone, the synthetic progestin medroxyprogesterone acetate (MPA, Provera) did not increase DHP and THP levels and did not prevent kainic-acid-induced neuronal loss. The administration of the 5,-reductase inhibitor finasteride prevented the increase in the levels of DHP and THP in plasma and hippocampus as a result of progesterone administration and abolished the neuroprotective effect of progesterone. Both DHP and THP were neuroprotective against kainic acid. However, the administration of indomethacin, a 3,-hydroxysteroid dehydrogenase inhibitor, blocked the neuroprotective effect of both DHP and THP, suggesting that both metabolites are necessary for the neuroprotective effect of progesterone. In conclusion, our findings indicate that progesterone is neuroprotective against kainic acid excitotoxicity in vivo while the synthetic progestin MPA is not and suggest that progesterone metabolism to its reduced derivatives DHP and THP is necessary for the neuroprotective effect of the hormone. © 2006 Wiley Periodicals, Inc. J Neurobiol, 2006 [source] Applicability of pushover methods for the seismic analysis of single-column bent viaductsEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 8 2008Tatjana Isakovi Abstract An overview of the applicability of a typical single-mode pushover method (the N2 method) and two typical multi-mode pushover methods (the modal pushover analysis (MPA) and incremental response spectrum analysis (IRSA) methods) for the analysis of single column bent viaducts in the transverse direction is presented. Previous research, which was limited to relatively short viaducts supported by few columns, has been extended to longer viaducts with more bents. The single-mode N2 method is accurate enough for bridges where the effective modal mass of the fundamental mode is at least 80% of the total mass. The applicability of this method depends on (a) the ratio of the stiffness of the superstructure to that of the bents and (b) the strength of the bents. In short bridges with few columns, the accuracy of the N2 method increases as the seismic intensity increases, whereas in long viaducts (e.g. viaducts with lengths greater than 500,m) the method is in general less effective. In the case of the analyzed moderately irregular long viaducts, which are common in construction design practice, the MPA method performed well. For the analysis of bridges where the modes change significantly, depending on the seismic intensity, the IRSA method is in principle more appropriate, unless a viaduct is torsionally sensitive. In such cases, all simplified methods should be used with care. Copyright © 2008 John Wiley & Sons, Ltd. [source] Simplified seismic analysis of asymmetric building systemsEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 4 2007Jui-Liang Lin Abstract The paper reviews the uncoupled modal response history analysis (UMRHA) and modal pushover analysis (MPA) procedure in the analysis of asymmetric structures. From the pushover curves in ADRS format, showing the relationships of base shear versus roof translation and base torque versus roof rotation, a bifurcating characteristic of the pushover curves of an asymmetric structure is observed. A two-degree-of-freedom (2DOF) modal stick is constructed using lump mass eccentrically placed at the end of beam which is connected with the column by a rotational spring. By converting the equation of motion of a whole structure into 2DOF modal equations, all of the elastic properties in the 2DOF modal sticks can be determined accurately. A mathematical proof is carried out to demonstrate that the 2DOF modal stick is consistent with the single-degree-of-freedom (SDOF) modal stick at elastic state. The bifurcating characteristic of modal pushover curves and the interaction of modal translation and rotation can be considered rationally by this 2DOF modal stick. In order to verify the effectiveness of this proposed 2DOF modal stick, a two-storey asymmetric building structure was analysed by the UMRHA procedure incorporating this novel 2DOF modal sticks (2DMPA) and conventional SDOF modal sticks (SDMPA), respectively. The analytical results are compared with those obtained by nonlinear response history analysis (RHA). It is illustrated that the accuracy of the rotational response histories obtained by 2DMPA is much better than those obtained by SDMPA. Consequently, the estimations of translational response histories on flexible side (FS) and stiff side (SS) of the building structure are also improved. Copyright © 2006 John Wiley & Sons, Ltd. [source] A modal pushover analysis procedure to estimate seismic demands for unsymmetric-plan buildingsEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 8 2004Anil K. Chopra Abstract An Erratum has been published for this article in Earthquake Engng. Struct. Dyn. 2004; 33:1429. Based on structural dynamics theory, the modal pushover analysis (MPA) procedure retains the conceptual simplicity of current procedures with invariant force distribution, now common in structural engineering practice. The MPA procedure for estimating seismic demands is extended to unsymmetric-plan buildings. In the MPA procedure, the seismic demand due to individual terms in the modal expansion of the effective earthquake forces is determined by non-linear static analysis using the inertia force distribution for each mode, which for unsymmetric buildings includes two lateral forces and torque at each floor level. These ,modal' demands due to the first few terms of the modal expansion are then combined by the CQC rule to obtain an estimate of the total seismic demand for inelastic systems. When applied to elastic systems, the MPA procedure is equivalent to standard response spectrum analysis (RSA). The MPA estimates of seismic demand for torsionally-stiff and torsionally-flexible unsymmetric systems are shown to be similarly accurate as they are for the symmetric building; however, the results deteriorate for a torsionally-similarly-stiff unsymmetric-plan system and the ground motion considered because (a) elastic modes are strongly coupled, and (b) roof displacement is underestimated by the CQC modal combination rule (which would also limit accuracy of RSA for linearly elastic systems). Copyright © 2004 John Wiley & Sons, Ltd. [source] Interference from Trace Copper in Electrochemical Investigations Employing Carboxylic Acid Terminated Thiol Modified Gold ElectrodesELECTROANALYSIS, Issue 6 2009Xiaohu Qu Abstract Unexpectedly, electrochemistry at variable chain length carboxylic acid terminated alkylthiol self-assembled monolayers (SAMs) on gold electrodes gives rise to a Faradaic process in buffered aqueous electrolyte solution. In particular, the three-carbon chain length, 3-mercaptopropionic acid (MPA), exhibits a chemically reversible process with a mid-point potential of 175,mV vs. Ag/AgCl under conditions of cyclic voltammetry. This process is associated with the presence of trace (parts per billion) amounts of copper(II) ions present in the chemical reagents used to prepare the aqueous electrolyte and also from the gold electrode itself. The carboxylic acid moiety on the SAM concentrates Cu2+ ions by coordination and this surface confined layer is then reduced. Methods to minimize the interference of Cu2+ ions at carboxylic acid terminated SAM are discussed and caution with respect to the interpretation of protein electrochemistry is recommended when using carboxylic acid functionalized SAMs to provide biocompatible electrochemical transduction surfaces, unless a metal free environment can be obtained. [source] A Lactulose Bienzyme Biosensor Based on Self-Assembled Monolayer Modified ElectrodesELECTROANALYSIS, Issue 17 2004Susana Campuzano Abstract A bienzyme biosensor in which the enzymes ,-galactosidase (,-Gal), fructose dehydrogenase (FDH), and the mediator tetrathiafulvalene (TTF) were coimmobilized by cross-linking with glutaraldehyde atop a 3-mercaptopropionic acid (MPA) self-assembled monolayer on a gold disk electrode, is reported. The working conditions selected were Eapp=+0.10,V and (25±1),°C. The useful lifetime of one single TTF-,-Gal-FDH-MPA-AuE was surprisingly long, 81,days. A linear calibration plot was obtained for lactulose over the 3.0×10,5,1.0×10,3,mol L,1 concentration range, with a limit of detection of 9.6×10,6,mol L,1. The effect of potential interferents (lactose, glucose, galactose, sucrose, and ascorbic acid) on the biosensor response was evaluated. The behavior of the SAM-based biosensor in flow-injection systems in connection with amperometric detection was tested. The analytical usefulness of the biosensor was evaluated by determining lactulose in a pharmaceutical preparation containing a high lactulose concentration, and in different types of milk. Finally, the analytical characteristics of the TTF-,-Gal-FDH-MPA-AuE are critically compared with those reported for other recent enzymatic determinations of lactulose. [source] Concentration of methylprednisolone in the centrodistal joint after administration of methylprednisolone acetate in the tarsometatarsal jointEQUINE VETERINARY JOURNAL, Issue 2 2005A. SERENA Summary Reasons for performing study: The centrodistal (CD) and tarsometatarsal (TMT) joints are often injected individually with a corticosteroid to resolve lameness caused by osteoarthritis (OA). There are no data available regarding diffusion of methylprednisolone (MP) from the TMT joint to the CD joint. Hypothesis: A therapeutic concentration of MP diffuses into the CD joint after methylprednisolone acetate (MPA) is administered into the TMT joint. Objective: To measure the concentration of MP in the CD joint after MPA was administered into the TMT joint. Methods: MPA was administered into a TMT joint of 16 horses. At different times, the ipsilateral CD joint of these horses was injected with a small amount of saline and recovered saline was measured for concentration of MP using high performance liquid chromatography. Results: Six hours after administration of MPA into the TMT joint, a therapeutic concentration of MP was found in all 10 CD joints sampled at this time. Conclusions: Horses with pain arising from the distal 2 joints of the hock can be treated by administering MPA into the TMT joint alone. Potential relevance: Administering MPA into the TMT joint only, to treat OA of the distal 2 hock joints, reduces the difficulties and risks associated with centesis of the CD joint. [source] Small Molecule-Controlled Spontaneous Growth of Rose-Like Se Crystals at Room TemperatureEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 7 2008Da-Wei Deng Abstract The spontaneous growth of rose-like Se crystals in aqueous solutions at room temperature is reported. The formation of rose-like Se crystals is based on the oxidation of Na2Se in the presence of thioglycerol solution at pH = 11 in a dark ambient atmosphere. In alkaline solutions, the growth evolution of rose-like Se crystals with aging time was followed by scanning electron microscopy (SEM), and an interesting formation process from initial Se monomers to amorphous Se (a-Se) spheres, and to the final rose-like complex structures of Se crystals was observed. Seven kinds of small molecules with different structures, including 1-thioglycerol (TG), mercaptamine (MA), L -cysteine (L -cys), 3-mercaptopropionic acid (MPA), thioglycolic acid (TGA), glycerol (GLY), and L -serine (L -ser), were used to manipulate the growth of Se crystals. The experimental results show that the structures of the small molecules play a key role in the growth of the Se crystals. The presence of thiols in the structure of the small molecules is favorable for the formation of the aggregates of Se crystals, and other termini, such as ,NH2, ,OH, or ,COO,, will determine whether the aggregates of Se crystals are made up of Se slices or Se prisms. These observations suggest that the ligand molecules have a crucial effect on the nucleation, monomers, and growth of nanocrystals. The selection of ligands can be extended to other important materials for further preparation of nanocrystals with desired shapes. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Progestin upregulates G-protein-coupled receptor 30 in breast cancer cellsFEBS JOURNAL, Issue 10 2002Tytti M. Ahola A differential display method was used to study genes the expression of which is altered during growth inhibition induced by medroxyprogesterone acetate (MPA). A transcript of G-protein-coupled receptor 30 (GPR30) was upregulated by MPA in estrogen-treated MCF-7 breast cancer cells. Northern-blot analysis showed a progestin-specific primary target gene, which was enhanced by progesterone and different progestins, but not by dihydrotestosterone or dexamethasone, and which was abrogated by antiprogestin RU486. The dose-dependent and time-dependent increase in GPR30 mRNA expression correlated with MPA-induced growth inhibition in MCF-7 cells. Additionally, GPR30 upregulation by progestin correlated with growth inhibition when a comparison was made between different breast cancer cell lines. The ERK1/ERK2 pathway is capable of inducing progesterone receptor-dependent and ligand-dependent transcription. Thus we sought to establish whether different MAPK pathway inhibitors affect progestin-induced GPR30 mRNA regulation. The regulation of GPR30 was independent of ERK pathway activation, but the p38 pathway inhibitor induced GPR30 expression, which suggested a potential gene regulation pathway. These data demonstrate a new progestin target gene, the expression of which correlates with growth inhibition. [source] Spatially explicit fisheries simulation models for policy evaluationFISH AND FISHERIES, Issue 4 2005Dominique Pelletier Abstract This paper deals with the design of modelling tools suitable for investigating the consequences of alternative policies on the dynamics of resources and fisheries, such as the evaluation of marine protected areas (MPA). We first review the numerous models that have been developed for this purpose, and compare them from several standpoints: population modelling, exploitation modelling and management measure modelling. We then present a generic fisheries simulation model, Integration of Spatial Information for FISHeries simulation (ISIS-Fish). This spatially explicit model allows quantitative policy screening for fisheries with mixed-species harvests. It may be used to investigate the effects of combined management scenarios including a variety of policies: total allowable catch (TAC), licenses, gear restrictions, MPA, etc. Fisher's response to management may be accounted for by means of decision rules conditioned on population and exploitation parameters. An application to a simple example illustrates the relevance of this kind of tool for policy screening, particularly in the case of mixed fisheries. Finally, the reviewed models and ISIS-Fish are discussed and confronted in the light of the underlying assumptions and model objectives. In the light of this discussion, we identify desirable features for fisheries simulation models aimed at policy evaluation, and particularly MPA evaluation. [source] Relationship between intensity of physical activity and health-related quality of life in Portuguese institutionalized elderlyGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 4 2008Alexandrina Lobo Aims: Health-related quality of life (HRQOL) is considered to be the key goal for health promotion in older people. This study explores the relationship between HRQOL and objectively measured intensity of physical activity (PA) in institutionalized older adults. The analysis of the PA patterns of the subjects in relation to recommended levels of PA was also performed. Methods: One hundred and eighty-five residents of long-term care homes aged 65 years or more, volunteered for this study. The Medical Outcome Study Short Form 36-Item health survey (MOS SF-36) questionnaires and the uni-axial MTI Actigraph were used to assess HRQOL and PA, respectively. Participants were classified as less active, reasonably active and more active by tertile of moderated physical activity (MPA). Results: (i) The men represented a greater number of counts/h and min of MPA in all the tertile groups; (ii) men from the less active group had a significantly higher body mass index; (iii) women came third and exhibited less total activity even though they used this time in more intense activities; (iv) there was a higher significant correlation between MPA, physical function and negative association with body pain in relation to the time of institutionalization in both sexes but was more strongly visible in men; and (v) only men presented a significant positive association with physical health, mental health and vitality. Conclusion: Any intensity of PA seems to be better than no activity for HRQOL, but MPA confers greater benefits for the perception of physical function and body pain in the case of institutionalized elderly persons. [source] Dendrimer Precursors for Nanomolar and Picomolar Real-Time Surface Plasmon Resonance/Potentiometric Chemical Nerve Agent Sensing Using Electrochemically Crosslinked Ultrathin Films,ADVANCED FUNCTIONAL MATERIALS, Issue 15 2006P. Taranekar Abstract Nanomolar detection and specific recognition of pinacolyl methylphosphonate (PMP), a hydrolysis product and an analog of a relatively persistent class of toxic nerve agents, has been achieved. In addition, picomolar sensitivity is observed with methylphosphonic acid (MPA), an end-hydrolysis product for all organophosphate-based nerve agents. This is achieved using a combined surface plasmon resonance (SPR) and potentiometry setup. A modified polyamidoamine (PAMAM) carbazole/Cu2+ dendrimer, which is electrochemically crosslinked on a self-assembled monolayer (SAM) modified Au,substrate, is used as an active sensing element for trapping the nerve-agent analogs. The ultrathin films have been used to study the anchoring of nerve agents via non-covalent interactions. The carbazole to amine ratio is optimized to ensure free primary amines are available to interact with the analyte and the Cu2+ ions present in the system, which further enhances the selectivity. The carbazole group on the periphery serves a dual purpose: crosslinking the dendrimers to form a conjugated network film, and generating the potentiometric response. The adsorption kinetics are monitored by using an in,situ SPR/potentiometric setup. This technique not only offers a real-time dual detection of highly toxic nerve-agent analogs, but also shows viability for future sensor-device applications. [source] Epidemiology of primary systemic vasculitis in the Australian Capital Territory and south-eastern New South WalesINTERNAL MEDICINE JOURNAL, Issue 11 2008A. S. Ormerod Abstract Background:, The aim of the study was to determine the epidemiology of primary systemic vasculitis in the Australian Capital Territory and the surrounding rural region between 1995 and 2005. Methods:, Cases were ascertained by a medical record search according to international consensus classification criteria. For antineutrophil cytoplasmic antibody-associated vasculitides, ascertainment was corroborated by a search of all positive antineutrophil cytoplasmic antibody serology during the study period. Denominators were obtained from region-specific census data collected during the study period. Prevalence, incidence and patient characteristics for primary systemic vasculitides were determined for two 5-year periods, 1995,1999 and 2000,2004. Results:, We identified 41 cases of primary systemic vasculitides (Wegener's granulomatosis (WG), microscopic polyangiitis (MPA), Churg,Strauss syndrome or polyarteritis nodosa) between 1995 and 1999 and 67 between 2000 and 2004, giving prevalences of 95/million (95% confidence interval (CI) 76.9,116.1) and 148/million (95%CI 125.1,173.9), respectively. Annual incidence was similar in both periods (approximately 17/year per million adult population). Disease-specific incidences (per million per year) for each of the two periods were 8.8 and 8.4 for WG, 2.3 and 5.0 for MPA, 2.3 and 2.2 for Churg,Strauss syndrome and 2.3 and 1.1 for polyarteritis nodosa. The rural incidence of MPA was 13.9 (95%CI 7.7,23.5) compared with 1.6 (95%CI 0.2,7.2) in the city and there was a trend towards a higher incidence of WG in rural than urban areas. Conclusion:, The overall incidence of primary systemic vasculitides is similar to that reported from other developed countries. WG is more common in south-eastern Australia than in southern Europe, whereas MPA is less common. There was a trend towards higher incidence of antineutrophil cytoplasmic antibody-associated vasculitides in rural than urban areas. [source] Steroid hormone receptors and coregulators in endocrine-resistant and estrogen-independent breast cancer cellsINTERNATIONAL JOURNAL OF CANCER, Issue 4 2006Nanna Sarvilinna Abstract Resistance to hormonal therapy is often a problem in the treatment of breast cancer patients. It has been suggested that resistance could be explained by altered nuclear hormone receptor or coregulator levels or inappropriately increased agonist activity of selective estrogen receptor modulator (SERM). To test these hypotheses, we have established novel MCF-7 cell line-derived in vitro models of anti-estrogen- and progestin-resistant and estrogen-independent breast cancer by long-term culture in the presence of toremifene and medroxyprogesterone acetate (MPA) and in the absence of estradiol, respectively. Using cell growth and multiprobe ribonuclease protection assays, the expression of 5 nuclear hormone receptors and 9 coregulators as well as the alterations in the cell proliferation and target gene transcription in response to hormonal treatments were studied. Progesterone receptor (PR) expression was decreased and silencing mediator for retinoid acid and thyroid hormone receptors (SMRT) and amplified in breast cancer-1 (AIB1) expression increased in anti-estrogen-resistant cells. Estrogen caused PR and ER, upregulation in all cell lines, but we did not observe increased agonist activity of anti-estrogen measured by regulation of these estrogen target genes. Basal ER, levels and estrogenic growth response were decreased and p300/CBP-associated factor (pCAF) and AIB1 upregulated by estrogen in progestin-resistant cells, but coregulator levels were unchanged. Estrogen-independent cells were still estrogen-responsive and PR, nuclear receptor corepressor (N-CoR) and SMRT expression was increased whereas steroid receptor coactivator-1 (SRC-1a) and CBP-related protein p300 (p300) expression decreased. Their growth was inhibited by toremifene, but estradiol was able to abrogate this effect, which might have interesting clinical implications concerning the use of postmenopausal hormone replacement therapy. © 2005 Wiley-Liss, Inc. [source] Are the Hirshfeld and Mulliken population analysis schemes consistent with chemical intuition?INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 9 2009Soumen Saha Abstract In the present article, we report a comparative study between the Hirshfeld and Mulliken population analysis schemes (abbreviated as HPA and MPA, respectively). Trends of atomic charges derived from these two population analysis schemes are compared with those expected from other commonly used chemical concepts like electronegativity, inductive effects, and resonance effects. Although previous studies on intramolecular reactivity sequences demonstrated that HPA generates reliable and non-negative (and thus physically more realistic) condensed Fukui function (FF) values, the present study reveals problems with the HPA charge partitioning technique. Specifically, HPA fails to reproduce reliable intermolecular and intramolecular charge trends in several systems. Reasons for the success and failure of HPA are discussed and a method for improving the Hirshfeld charge partitioning is proposed. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 [source] Model population analysis for variable selectionJOURNAL OF CHEMOMETRICS, Issue 7-8 2010Hong-Dong Li Abstract To build a credible model for given chemical or biological or clinical data, it may be helpful to first get somewhat better insight into the data itself before modeling and then to present the statistically stable results derived from a large number of sub-models established only on one dataset with the aid of Monte Carlo Sampling (MCS). In the present work, a concept model population analysis (MPA) is developed. Briefly, MPA could be considered as a general framework for developing new methods by statistically analyzing some interesting parameters (regression coefficients, prediction errors, etc.) of a number of sub-models. New methods are expected to be developed by making full use of the interesting parameter in a novel manner. In this work, the elements of MPA are first considered and described. Then, the applications for variable selection and model assessment are emphasized with the help of MPA. Copyright © 2010 John Wiley & Sons, Ltd. [source] Pharmacokinetics and pharmacodynamics of prasugrel in subjects with moderate liver diseaseJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 5 2009D. S. Small PhD Summary Background and Objective:, Prasugrel is a thienopyridine antiplatelet agent under investigation for the prevention of atherothrombotic events in patients with acute coronary syndrome who undergo percutaneous coronary intervention. Patients with chronic liver disease are among those in the target population for prasugrel. As hepatic enzymes play a key role in formation of prasugrel's active metabolite, hepatic impairment could affect the safety and/or efficacy of prasugrel in such patients. Methods:, This was a parallel-design, open-label, multiple dose study of 30 subjects, 10 with moderate hepatic impairment (Child-Pugh Class B) and 20 with normal hepatic function. Prasugrel was administered orally as a 60-mg loading dose (LD) and daily 10-mg maintenance doses (MDs) for 5 days. Pharmacokinetic parameters (AUC0,t, Cmax and tmax) and maximal platelet aggregation (MPA) by light transmission aggregometry were assessed after the LD and final MD. Results and Discussion:, Exposure to prasugrel's active metabolite was comparable between healthy subjects and those with moderate hepatic impairment. Point estimates for the ratios of geometric least square means for AUC0,t and Cmax after the LD and last MD ranged from 0·91 to 1·14. MPA to 20 ,m ADP was similar between subjects with moderate hepatic impairment and healthy subjects for both the LD and MD. Prasugrel was well tolerated by all subjects, and adverse events were mild in severity. Conclusion:, Moderate hepatic impairment appears to have no effect on exposure to prasugrel's active metabolite. Furthermore, MPA results suggest that moderate hepatic impairment has little or no effect on platelet aggregation relative to healthy controls. Overall, these results suggest that a dose adjustment would not be required in moderately hepatically impaired patients taking prasugrel. [source] An Integrative Model of Mobile Phone AppropriationJOURNAL OF COMPUTER-MEDIATED COMMUNICATION, Issue 3 2008Werner Wirth The evolution of mobile communication devices and services has taken up a dynamic that makes any prognosis in the field almost impossible. Whereas part of this dynamic may remain inscrutable, we believe that a much higher degree of explanation can be achieved by systematically paying closer attention to the process of appropriation. To seize upon this potential, we present an integrative model to analyze mobile phone appropriation (the "MPA model"). The model is based on existing theoretical approaches of the quantitative "adoption" paradigm (namely, Innovation Diffusion Theory and Theory of Planned Behavior) as well as the mostly qualitative research paradigm devoted to "appropriation" (Cultural studies and Frame Analysis), with the Uses-and-Gratifications approach playing a role on both sides. The model has been developed, operationalized and empirically applied in the context of mobile phone appropriation; however, with certain modifications it can be adapted to other information and communications technology (ICT) innovations. Résumé An Integrative Model of Mobile Phone Appropriation The evolution of mobile communication devices and services has taken up a dynamic that makes any prognosis in the field almost impossible. Whereas part of this dynamic may remain inscrutable, we believe that a much higher degree of explanation can be achieved by systematically paying closer attention to the process of appropriation. To seize upon this potential, we present an integrative model to analyze mobile phone appropriation (the "MPA model"). The model is based on existing theoretical approaches of the quantitative "adoption" paradigm (namely, Innovation Diffusion Theory and Theory of Planned Behavior) as well as the mostly qualitative research paradigm devoted to "appropriation" (Cultural studies and Frame Analysis), with the Uses-and-Gratifications approach playing a role on both sides. The model has been developed, operationalized and empirically applied in the context of mobile phone appropriation; however, with certain modifications it can be adapted to other information and communications technology (ICT) innovations. ZhaiYao [source] Estimation of pulse wave velocity in main pulmonary artery with phase contrast MRI: Preliminary investigationJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 6 2006Hsu-Hsia Peng MS Abstract Purpose To assess the feasibility and reproducibility of a noninvasive MRI method to measure pulse wave velocity (PWV) in the main pulmonary artery (MPA). Materials and Methods A total of 17 subjects without history of pulmonary diseases (38.2 ± 18.4 years) participated in this study. Series of MR velocity maps of the MPA were acquired at 2 cm above the pulmonary valves using a two-dimensional phase-contrast sequence. Effective temporal resolution was 11 msec after interleaving two dynamic series with different values of electrocardiograph (ECG) trigger delay. PWV was derived as the rate of MPA flow variations per unit change in MPA cross-sectional area, during early systole. Seven healthy subjects underwent three repetitive examinations to investigate intrascan and interscan reproducibility. Results Flow vs. area was highly linear in the MPA during early systole, with Pearson's coefficients ranging from 0.982 to 0.999, rendering derivation of PWV with little difficulty. Average value of PWV in MPA was 1.96 ± 0.27 m/second, in good agreement with literature values measured using invasive means. The percentage intra- and interscan differences were 5.46% and ,10.86%, respectively. Conclusion Phase-contrast MRI to noninvasively measure PWV in the MPA is feasible with good reproducibility. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc. [source] Proximal pulmonary artery blood flow characteristics in healthy subjects measured in an upright posture using MRI: The effects of exercise and age,JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 6 2005Christopher P. Cheng PhD Abstract Purpose To use MRI to quantify blood flow conditions in the proximal pulmonary arteries of healthy children and adults at rest and during exercise in an upright posture. Materials and Methods Cine phase-contrast MRI was used to calculate mean flow and reverse flow index (RFI) in the main (MPA), right (RPA), and left (LPA) pulmonary arteries in healthy children and adults in an open-MRI magnet equipped with an upright MRI-compatible ergometer. Results From rest to exercise (150% resting heart rate), blood flow (liters/minute/m2) increased in the RPA (1.4 ± 0.3 vs. 2.5 ± 0.4; P < 0.001), LPA (1.1 ± 0.3 vs. 2.2 ± 0.6; P < 0.001), and MPA (2.7 ± 0.5 vs. 4.9 ± 0.5; P < 0.001). RFI decreased in the LPA (0.040 ± 0.030 vs. 0.017 ± 0.018; P < 0.02) and MPA (0.025 ± 0.024 vs. 0.008 ± 0.007; P < 0.03). Adults experienced greater retrograde flow in the MPA than the children (0.042 ± 0.029 vs. 0.014 ± 0.012; P < 0.02). Conclusion It appears that at both rest and during exercise, in children and adults alike, RPA/LPA mean blood flow distribution is predominantly determined by distal vascular resistance, while retrograde flow is affected by proximal pulmonary bifurcation geometry. J. Magn. Reson. Imaging 2005;21:752,758. © 2005 Wiley-Liss, Inc. [source] DNA aptamers developed against a soman derivative cross-react with the methylphosphonic acid core but not with flanking hydrophobic groupsJOURNAL OF MOLECULAR RECOGNITION, Issue 3 2009John G. Bruno Abstract Twelve rounds of systematic evolution of ligands by exponential enrichment (SELEX) were conducted against a magnetic bead conjugate of the para -aminophenylpinacolylmethylphosphonate (PAPMP) derivative of the organophosphorus (OP) nerve agent soman (GD). The goal was to develop DNA aptamers that could scavenge GD in vivo, thereby reducing or eliminating the toxic effects of this dangerous compound. Aptamers were sequenced and screened in peroxidase-based colorimetric plate assays after rounds 8 and 12 of SELEX. The aptamer candidate sequences exhibiting the highest affinity for the GD derivative from round 8 also reappeared in several clones from round 12. Each of the highest affinity PAPMP-binding aptamers also bound methylphosphonic acid (MPA). In addition, the aptamer with the highest overall affinity for PAPMP carried a sequence motif (TTTAGT) thought to bind MPA based on previously published data (J. Fluoresc 18: 867,876, 2008). This sequence motif was found in several other relatively high affinity PAPMP aptamer candidates as well. In studies with the nerve agent GD, pre-incubation of a large molar excess of aptamer candidates failed to protect human butyrylcholinesterase (BuChE) from inhibition. With the aid of three-dimensional molecular modeling of the GD derivative it appears that a hydrophilic cleft sandwiched between the pinacolyl group and the p -aminophenyl ring might channel nucleotide interactions to the phosphonate portion of the immobilized GD derivative. However, bona fide GD free in solution may be repulsed by the negative phosphate backbone of aptamers and rotate its phosphonate and fluorine moieties away from the aptamer to avoid being bound. Future attempts to develop aptamers to GD might benefit from immobilizing the pinacolyl group of bona fide GD to enhance exposure of the phosphonate and fluorine to the random DNA library. Copyright © 2008 John Wiley & Sons, Ltd. [source] Effects of Long-Term Hormone Treatment and of Tibolone on Monoamines and Monoamine Metabolites in the Brains of Ovariectomised, Cynomologous MonkeysJOURNAL OF NEUROENDOCRINOLOGY, Issue 9 2006R. B. Gibbs The effects of long-term hormone treatment on monoamines and monoamine metabolites in different regions of the primate brain were examined and compared. Ovariectomised Cynomologous monkeys received daily oral administration of either conjugated equine oestrogens (CEE), CEE + medroxyprogesterone acetate (MPA), or a low or high dose of tibolone, for a period of 2 years. Tissue punches collected from frozen sections through various regions of the forebrain, midbrain, and hindbrain were assayed for levels of dopamine, dihydroxyphenylacetic acid (DOPAC), serotonin, 5-hydroxyindole acetic acid (5-HIAA), and norepinephrine by high-performance liquid chromatography. Few differences between hormone-treated animals and ovariectomised controls were observed. No statistically significant effects of CEE relative to controls were detected in any of the seven brain regions analysed. Animals treated with CEE + MPA showed significant reductions in 5-HIAA in the dorsal raphe nucleus, a significant reduction in dopamine in the hypothalamus, and a significant reduction in serotonin (5-HT) levels in area 8AD of the frontal cortex. Similar to CEE, no significant effects of tibolone relative to controls were detected; however, animals treated with high-dose tibolone showed a decrease in 5-HT levels in the frontal cortex that approached significance and was similar to the effect of CEE + MPA. Collectively, the findings suggest that long-term oral administration of these compounds has relatively few effects on the levels of dopamine, serotonin, and their primary metabolites in the primate brain. This differs from the significant effects on serotonergic and dopaminergic systems detected following parenteral treatment with oestradiol and progesterone, and likely reflects differences between the effects of treating with CEE + MPA versus oestradiol and progesterone on brain monoaminergic systems. [source] Serotonergic Neurones in the Dorsal Raphe Nucleus That Project into the Medial Preoptic Area Contain Oestrogen Receptor ,JOURNAL OF NEUROENDOCRINOLOGY, Issue 10 2001H. Lu Abstract Serotonin is involved in female sexual behaviour in which the medial preoptic area (MPA) has a pivotal role. The present study used immunohistochemistry, in situ hybridization and retrograde transport analysis to investigate whether serotonin neurones in the dorsal raphe nucleus (DRN) of females projecting into the MPA contained oestrogen receptor , or ,. The projection of serotonin neurones from the DRN to the MPA was confirmed using the microinjection of Fluoro-Gold (FG), a fluorescent retrograde tracer, into the MPA of ovariectomized (OVX-group) and OVX-rats treated with oestradiol benzoate (E2-group). A number of serotonin neurones in the DRN were labelled with FG, indicating that these serotonin neurones in DRN project their terminals into the MPA. FG-labelled serotonin neurones expressed ER, mRNA in the DRN, and the number of the serotonin neurones containing ER, mRNA between the OVX-group and the E2-treated group was not significantly different. Serotonin neurones in the DRN did not express ER,-immunoreactivity. Since previous findings showed that the density of serotonin-immunoreactive fibres and the concentration of serotonin within the MPA was significantly lower in the E2-group than the OVX-group, our present observations suggested that the regulatory effects of E2 on the serotonergic neurone system in the MPA may be via ER, within the serotonin-containing cells in the DRN of female rats. [source] MMP-mediated collagen breakdown induced by activated protein C in equine cartilage is reduced by corticosteroidsJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2010Elaine R. Garvican Abstract The plasma serine protease activated protein C (APC) is synthesized by human chondrocytes at sites of pathological cartilage fibrillation. APC levels are increased in osteoarthritis (OA) synovial fluid, and in vitro APC has been shown to synergize with interleukin-1, (IL-1) to promote degradation from ovine cartilage. A model of equine cartilage degradation was established and used to explore corticosteroid activities. Intraarticular corticosteroids are a commonly prescribed treatment for joint disease, however their role in disease modification remains unclear. APC synergized with IL-1 or tumor necrosis factor-, (TNF,), promoting significant collagen degradation from equine cartilage explants within 4 days, but did not augment glycoaminoglycan (GAG) release. APC activated pro-matrix metalloproteinases (MMP)-2 but not pro-MMP-9, as assessed by gelatin zymography. APC did not directly activate pro-MMP-13. Dexamethasone, triamcinolone, and methylprednisolone acetate (MPA) were evaluated at concentrations between 10, 5M and 10,10M. High concentrations significantly increased GAG release from IL-1+APC,treated explants. With the exception of MPA at 10,10M, all concentrations of corticosteroids caused significant decreases in IL-1+APC-driven hydroxyproline loss. Treatment with corticosteroids suppressed expression of MMP-1, -3, and -13 mRNA. The collagenolysis associated with IL-1+APC synergy, and the inhibition of this effect by corticosteroids may involve gelatinase activation and downregulation of MMP expression, respectively. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:370,378, 2010 [source] First Report of Rhizoctonia solani AG-7 on Cotton in EgyptJOURNAL OF PHYTOPATHOLOGY, Issue 4 2010Kamel A. Abd-Elsalam Abstract Eighty-two isolates of Rhizoctonia solani were recorded from roots of naturally-infected seedlings of the Egyptian cotton (Gossypium barbadense L.). Anastomosis groups (AGs) of the isolates were determined by using 13 different AGs testers. Three (3.7%) of the isolates were identified as R. solani AG7, while the remaining isolates were belonging to the AG 2-1, AG4 and AG5. The identification of the three isolates was based on the frequency of the C2 reaction with the AG7 tester isolate. No fusion was observed between AG7 and isolates representing the other 13 AGs. Colonies of AG7 isolates grown on potato dextrose agar (PDA), malt yeast agar (MYA) and melt peptone agar (MPA) were brown to dark brown with aerial mycelium and sclerotia. The isolates had pitted sclerotial clusters and brownish exudates after 21 days of culturing on PDA, but without clear zonation. Pathogenicity test under greenhouse conditions revealed that AG7 caused the common symptoms of damping,off, which included seed rot, lesions on the hypocotyls and root rot. [source] Monolayers of sulfur-containing molecules at metal surfaces as studied using SERS: 3, 3,-thiodipropionic acid and 3-mercaptopropionic acid adsorbed on silver and copperJOURNAL OF RAMAN SPECTROSCOPY, Issue 6-7 2005Andrzej Kudelski Abstract The modification of metal surfaces with self-assembled thiol monolayers is the subject of intensive studies owing to both its fundamental interest in surface chemistry and its potential technological significance. In this work, the applicability of surface-enhanced Raman scattering (SERS) to determine the conformation and pKa values of ,-terminated thiol molecules was investigated. 3, 3,-Thiodipropionic acid (TDPA) and 3-mercaptopropionic acid (MPA) monolayers were spontaneously formed on silver and copper surfaces by adsorption from TDPA and MPA solutions, respectively. The structure of the monolayers formed was determined from SERS measurements. The SERS investigations showed that molecules forming TDPA monolayers prefer to adopt a gauche conformation of the,S,C,C chains, whereas in MPA monolayers formed from 1 mM MPA aqueous solution a significant part of the adsorbed molecules adopts a trans conformation. Formation on the metal surface of an MPA monolayer with high surface coverage of MPA makes dissociation of the carboxylic groups of MPA significantly more difficult. Analogous changes in the strength of similar adsorbed compounds have been reported by other groups. In contrast to those results, we found that the formation of monolayers from TDPA increases its acidic strength even at high surface coverage when monolayers are formed from relatively concentrated TDPA solutions. Probably the interaction of carboxylic groups with the metal surface is easier for TDPA than for MPA for geometric reasons. We consider that ionization of carboxylic groups increases the strength of this interaction. Copyright © 2005 John Wiley & Sons, Ltd. [source] Structures of monolayers formed from different HS,(CH2)2,X thiols on gold, silver and copper: comparitive studies by surface-enhanced Raman scatteringJOURNAL OF RAMAN SPECTROSCOPY, Issue 11 2003Andrzej Kudelski Abstract Molecules of 2-aminoethanethiol (cysteamine, CYS), 2-mercaptoethanol (MET), 3-mercaptopropionic acid (MPA), sodium 2-mercaptoethanesulphonate (MES) and 1-propanethiol (PTH) were spontaneously chemisorbed on electrochemically activated silver, copper and gold surfaces. The structure of monolayers formed was studied with surface-enhanced Raman scattering (SERS). In CYS and MPA monolayers the relative surface concentration of gauche conformers was higher than in MET, PTH and MES monolayers. This is probably due to double bonding to the metal surface by a fraction of adsorbed MPA and CYS molecules (via the sulphur moiety and the terminal carboxylic or amino group). In CYS, MET, MPA and PTH monolayers the surface concentration of trans conformers is significantly higher on Ag than on Au or Cu. The structures of MES monolayers on Ag, Au and Cu are similar, with very high surface concentrations of trans conformers. Statistically, the wavenumbers of ,(C,S) bands of both gauche and trans conformers are the highest on Au, slightly lower on Ag and the lowest for Cu. However the positions of ,(C,S) bands are also sensitive to the other parameters (e.g. C,C,S,metal torsion angle, the overall ordering of the monolayer). Therefore, the wavenumbers of ,(C,S) bands are not good indicators of differences in the interaction between chemisorbed thiols and the metal substrates. Desorption measurements suggest that part of the adsorbed molecules is bonded significantly weaker than the rest. Thiolate monolayers on Cu decomposed relatively easily, forming a layer of copper sulphide. The strength of adsorbed MPA acid is similar on all substrates. Copyright © 2003 John Wiley & Sons, Ltd. [source] Validation of limited sampling strategy for the estimation of mycophenolic acid exposure in Chinese adult liver transplant recipientsLIVER TRANSPLANTATION, Issue 12 2007Chen Hao Mycophenolate mofetil (MMF) is indicated as immunosuppressive therapy in liver transplantation. The abbreviated models for the estimation of mycophenolic acid (MPA) area under the concentration-time curve (AUC) have been established by limited sampling strategies (LSSs) in adult liver transplant recipients. In the current study, the performance of the abbreviated models to predict MPA exposure was validated in an independent group of patients. A total of 30 MPA pharmacokinetic profiles from 30 liver transplant recipients receiving MMF in combination with tacrolimus were used to compare 8 models' performance with a full 10 time-point MPA-AUC. Linear regression analysis and Bland-Altman analysis were used to compare the estimated MPA-AUC0-12h from each model against the measured MPA-AUC0-12h. A wide range of agreement was shown when estimated MPA-AUC0-12h was compared with measured MPA-AUC0-12h, and the range of coefficient of determination (r2) was from 0.479 to 0.936. The model based on MPA pharmacokinetic parameters C1h, C2h, C6h, and C8h had the best ability to predict measured MPA-AUC0-12h, with the best coefficient of determination (r2 = 0.936), the excellent prediction bias (2.18%), the best prediction precision (5.11%), and the best prediction variation (2SD = ±7.88 mg · h/L). However, the model based on MPA pharmacokinetic sampling time points C1h, C2h, and C4h was more suitable when concerned with clinical convenience, which had shorter sampling interval, an excellent coefficient of determination (r2 = 0.795), an excellent prediction bias (3.48%), an acceptable prediction precision (14.37%), and a good prediction variation (2SD = ±13.23 mg · h/L). Measured MPA-AUC0-12h could be best predicted by using MPA pharmacokinetic parameters C1h, C2h, C6h, and C8h. The model based on MPA pharmacokinetic parameters C1h, C2h, and C4h was more feasible in clinical application. Liver Transpl 13:1684,1693, 2007. © 2007 AASLD. [source] Conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium in liver transplant patients presenting gastrointestinal disorders: A pilot studyLIVER TRANSPLANTATION, Issue 9 2006Jérôme Dumortier Gastrointestinal (GI) disorders are one of the main adverse events in patients treated by mycophenolic acid (MPA). The aim of this prospective study was to evaluate the effect of conversion from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium (EC-MPS) in liver transplant patients presenting GI side-effects Since January 2003, stable liver transplant patients receiving MMF and presenting GI disorders, without evidence of other origin than MMF were enrolled. Conversion was performed without a washout period at an equimolar daily dosage. Thirty-six patients were included after a median delay of 45 months after liver transplantation (LT) (16 women and 20 men, median age of 47 years). Diarrhoea was the main clinical symptom (n = 28, 77.7%). At the time of inclusion, patients were treated with MMF since 18 months (range 3-28) and GI disorders were known for 9 months (range 3-12). After a median follow-up of 12 months after conversion, GI disorders were resolved in 20 patients (55%), improved in 6 patients (17%) and not modified or worsened in 10 patients (28%). Our results strongly suggest that conversion from MMF to EC-MPS in liver transplant patients can improve gastrointestinal disorders in a majority of the patients, and therefore might be considered as the best therapeutic option. Liver Transpl 12:1342-1346, 2006. © 2006 AASLD. [source] The use of MPA amide for the assignment of absolute configuration of a sterically hindered cyclic secondary amine by ,mix and shake' NMR methodMAGNETIC RESONANCE IN CHEMISTRY, Issue 1 2008Jinhai Gao Abstract We present here a new method using methoxyphenylacetic acid (MPA) as the chiral derivatizing agent (CDA) for the assignment of absolute configuration of cyclic secondary amines. The MPA amides were prepared using the purification-free ,mix and shake' method. A detailed conformational analysis for the two diastereomeric amides was conducted by 2D NMR experiments and molecular mechanics calculations. We have established that, in the most stable conformation of each syn rotamer of MPA amides, the H-, in the MPA moiety is oriented toward the bulky substituent group at the asymmetric carbon in the chiral amine, presumably to avoid steric and/or electrostatic interactions. The observed NMR data were correlated with the conformational model to allow unambiguous assignment of absolute configuration of secondary amines. The results demonstrate that the MPA can be used as a useful CDA in the case of sterically crowded cyclic secondary amines from which the MTPA amides are usually difficult to make. Copyright © 2008 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||||||||||||||||||||||||||