Exploring the functional domain and the target of the tetanus toxin light chain in neurohypophysial terminals

The tetanus toxin light chain blocks calcium induced vasopressin release from neurohypophysial nerve terminals. Here we show that histidine residue 233 within the putative zinc binding motif of the tetanus toxin light chain is essential for the inhibition of exocytosis, in the rat. The zinc chelating agent dipicolinic acid as well as captopril, an inhibitor of zinc-dependent peptidases, counteract the effect of the neurotoxin. Synthetic peptides, the sequences of which correspond to motifs present in the cytoplasmic domain of the synaptic vesicle membrane protein synaptobrevin 1 and 2, prevent the effect of the tetanus toxin light chain. Our results indicate that zinc bound to the zinc binding motif constitutes the active site of the tetanus toxin light chain. Moreover they suggest that cleavage of synaptobrevin by the neurotoxin causes the inhibition of exocytotic release of vasopressin from secretory granules

ProDGe: investigating protein-protein interactions at the domain level

An important goal of systems biology is the identification and investigation of known and predicted protein-protein interactions to obtain more information about new cellular pathways and processes. Proteins interact via domains, thus it is important to know which domains a protein contains and which domains interact with each other. Here we present the Java^TM^ program ProDGe (Protein Domain Gene), which visualizes existing and suggests novel domain-domain interactions and protein-protein interactions at the domain level. The comprehensive dataset behind ProDGe consists of protein, domain and interaction information for both layers, collected and combined appropriately from UniProt, Pfam, DOMINE and IntAct. Based on known domain interactions, ProDGe suggests novel protein interactions and assigns them to four confidence classes, depending on the reliability of the underlying domain interaction. Furthermore, ProDGe is able to identify potential homologous interaction partners in other species, which is particularly helpful when investigating poorly annotated species. We further evaluated and compared experimentally identified protein interactions from IntAct with domain interactions from DOMINE for six species and noticed that 31.13% of all IntAct protein interactions in all six species can be mapped to the actual interacting domains. ProDGe and a comprehensive documentation are freely available at http://www.cogsys.cs.uni-tuebingen.de/software/ProDGe

Evolution of E2 transition strength in deformed hafnium isotopes from new measurements on 172^{172}Hf, 174^{174}Hf, and 176^{176}Hf

The available data for E2 transition strengths in the region between neutron-deficient Hf and Pt isotopes are far from complete. More and precise data are needed to enhance the picture of structure evolution in this region and to test state-of-the-art nuclear models. In a simple model, the maximum collectivity is expected at the middle of the major shell. However, for actual nuclei, this picture may no longer be the case, and one should use a more realistic nuclear-structure model. We address this point by studying the spectroscopy of Hf. We remeasure the 2^+_1 half-lives of 172,174,176Hf, for which there is some disagreement in the literature. The main goal is to measure, for the first time, the half-lives of higher-lying states of the rotational band. The new results are compared to a theoretical calculation for absolute transition strengths. The half-lives were measured using \gamma-\gamma and conversion-electron-\gamma delayed coincidences with the fast timing method. For the determination of half-lives in the picosecond region, the generalized centroid difference method was applied. For the theoretical calculation of the spectroscopic properties, the interacting boson model is employed, whose Hamiltonian is determined based on microscopic energy-density functional calculations. The measured 2^+_1 half-lives disagree with results from earlier \gamma-\gamma fast timing measurements, but are in agreement with data from Coulomb excitation experiments and other methods. Half-lives of the 4^+_1 and 6^+_1 states were measured, as well as a lower limit for the 8^+_1 states. We show the importance of the mass-dependence of effective boson charge in the description of E2 transition rates in chains of nuclei. It encourages further studies of the microscopic origin of this mass dependence. New data on transition rates in nuclei from neighboring isotopic chains could support these studies.Comment: 16 pages, 16 figures, 7 tables; Abstract shortened due to character limi

The Effect of Prescription Drug Copayments on Utilization and Associated Overall Costs

The purpose of this research is to study the effect of an increase on prescription drug copayments on utilization and associated costs. Using a cross-sectional, time series, cohort study design consisting of 2,389 members continuously enrolled for 24 months, from one large employer enrolled in a Midwest HMO, this study compares 1998 prescription drug costs and utilization when there was a $0 copay, to 1999 costs utilization after a$5 copay was implemented. Using the difference-of-means test, empirical results indicate that: 1) Drug utilization (measured by prescription claims PMPY) declined from 1998 to 1999 but the decline was not statistically significant. 2) Total drug costs PMPY hcreased significantly (at the 1% level) from 1998 to 1999 because of an increased use of brand over generic drugs, which led to a statistically significant increase in ingredient cost. 3) However, overall drug costs to the HMO showed a statistically significant decrease of 1.6% from 1998 to 1999 for three reasons: a) The $5 copayment was introduced in 1999. b) There was a statistically significant decrease in fill fee PMPY to the HMO from 1998 to 1999. c) There was a statistically significant increase in the add-in-fee PMPY from 1998 to 1999. These three factors all contributed to the statistically significant reduction in prescription drug costs to the HMO from 1998 to 1999. Therefore, this study shows that an increase in a prescription drug copayment can provide substantial savings to both employers and HMOs without becoming a deterrent to overall utilization.Master'sCollege of Arts and Sciences: Public AdministrationUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/117772/1/Zell.pd

Observation of isotonic symmetry for enhanced quadrupole collectivity in neutron-rich 62,64,66Fe isotopes at N=40

The transition rates for the 2_{1}^{+} states in 62,64,66Fe were studied using the Recoil Distance Doppler-Shift technique applied to projectile Coulomb excitation reactions. The deduced E2 strengths illustrate the enhanced collectivity of the neutron-rich Fe isotopes up to N=40. The results are interpreted by the generalized concept of valence proton symmetry which describes the evolution of nuclear structure around N=40 as governed by the number of valence protons with respect to Z~30. The deformation suggested by the experimental data is reproduced by state-of-the-art shell calculations with a new effective interaction developed for the fpgd valence space.Comment: 4 pages, 2 figure

Ghosts of the past and dreams of the future: the impact of temporal focus on responses to contextual ingroup devaluation.

addresses: University of Exeter, Exeter, UK. [email protected]: Journal Article; Research Support, Non-U.S. Gov'tCopyright © 2012 SAGE Publications. Author's draft version; post-print. Final version published by Sage available on Sage Journals Online http://online.sagepub.com/The authors investigated the impact of temporal focus on group members' responses to contextual ingroup devaluation. Four experimental studies demonstrated that following an induction of negative ingroup evaluation, participants primed with a past temporal focus reported behavioral intentions more consistent with this negative appraisal than participants primed with a future temporal focus. This effect was apparent only when a negative (but not a positive) evaluation was induced, and only among highly identified group members. Importantly, the interplay between temporal focus and group identification on relevant intentions was mediated by individual self-esteem, suggesting that focus on the future may be conducive to separating negative ingroup appraisals from individual self-evaluations. Taken together, the findings suggest that high identifiers' responses to ingroup evaluations may be predicated on their temporal focus: A focus on the past may lock such individuals within their group's history, whereas a vision of the future may open up opportunities for change

Lifetime determination of excited states in Cd-106

Two separate experiments using the Differential Decay Curve Method have been performed to extract mean lifetimes of excited states in 106 Cd. The inedium-spin states of interest were populated by the Mo-98(C-12, 4n) Cd-106 reaction performed at the Wright Nuclear Structure Lab., Yale University. From this experiment, two isomeric state mean lifetimes have been deduced. The low-lying states were populated by the Mo-96(C-13, 3n)Cd-106 reaction performed at the Institut fur Kernphysik, Universitat zu Koln. The mean lifetime of the I-pi = 2(1)(+) state was deduced, tentatively, as 16.4(9) ps. This value differs from the previously accepted literature value from Coulomb excitation of 10.43(9) ps

Malat Metabolismus und die Rolle der NADP-Malat Enzym Isoformen in der C3-Modellpflanze A. thaliana

Obwohl Malat und Fumarat in eine Vielzahl von Stoffwechselweg der Pflanze involviert sind, bleibt ihre Funktion als Kohlenstoffquelle in C3-Pflanzen weitgehend ungeklärt. In dieser Arbeit wurden Arabidopsis thaliana Pflanzen und Stärkefreimutanten adg1 (ADG-Glukose-Phyrophosphorylase1 null Mutante) und pgm1 und sft1 (Phosphoglucomutase1 null Mutante), die ein plastidäres Mais-NADP-ME (MEm) überexprimierten, wurden genutzt um die Auswirkung eines extrem niedrigen Malat- und Fumarat-Gehalt au die Physiologie von C3-Pflanzen zu untersuchen. Die MEm-Überexpressions-Pflanzen entwickelten einen Kohlenstoffmangel-Phänotypen besonders unter Kurz-Tag-Bedingungen. Die Beobachteten Ergebnisse dieses Phänotyp untermauern die physiologische Rolle von Malat und Fumarat als essenzielle transiente Kohlenstoffquellen in C3-Pflanzen wie A. thaliana. Wir postulieren, dass das niedrige Level von organischen Säuren, das einem Karbohydrat-Mangel am Ende der Nacht folgt, als initiales Signal dient und eine Kaskade von Abläufen verursacht, die letztlich zur veränderten Substratnutzung in der Respiration hin zu hoch reduzierten Substraten, wie Fettsäuren und Proteinen während der langen Nachtphase bewirken. Dem folgend unterstützen unsere Ergebnisse die Annahme, das die organischen Säuren, Malat und Fumarat, äußerst wichtige C-Quellen im Metabolismus von A. thaliana darstellen. NADP-Malat-Enzym (NADP-ME, E.C. 1.1.1.40) katalysiert die oxidative Dekarboxylierung von L-Malat unter Gewinnung von Pyruvat, CO2 und NADPH. Obwohl die Rolle von NADP-ME in der C4-Photosynthese bekannt ist, bleiben die physiologischen Funktionen der C3-Isoformen bisher ungeklärt. Die Analyse des transkriptionalen Coexpressionsmuster zeigt, dass NADP-ME2 in Verbindung mit Genen steht, die in die Pathogenabwehr involviert sind. Unsere Arbeit zeigt, dass die gesamte NADP-ME Aktivität nach Infiltration mit pilzlichen und bakteriellen Elizitoren und nach Infektion mit dem hemibiotrophen pilzlichen Pathogen Colletotrichum higginsianum induziert wurde. Des weiteren konnte mit Funktionsverlust-Mutanten und mehreren biochemischen und physiologischen Methoden gezeigt werden, dass die beobachtete Aktivitätsänderung durch NADP-ME2 verursacht wurde und der Verlust des zytosolischen NADP-ME2 eine erhöhte Empfindlichkeit gegenüber Infektionen zur Folge hat. Unsere Ergebnisse lassen vermuten, dass NADP-ME2 in Mechanismen involviert ist, die NADPH für die ROS-Produktion bereitstellen könnten. NADP-ME3 könnte eine mögliche Rolle im Abbau der primären oder sekundären PCM-Wand während Pollen Entwicklung

Early apoptosis of porcine alveolar macrophages limits avian influenza virus replication and proinflammatory dysregulation

Pigs are evidently more resistant to avian than swine influenza A viruses, mediated in part through frontline epithelial cells and alveolar macrophages (AM). Although porcine AM (PAM) are crucial in influenza virus control, their mode of control is unclear. To gain insight into the possible role of PAM in the mediation of avian influenza virus resistance, we compared the host effects and replication of two avian (H2N3 and H6N1) and three mammalian (swine H1N1, human H1N1 and pandemic H1N1) influenza viruses in PAM. We found that PAM were readily susceptible to initial infection with all five avian and mammalian influenza viruses but only avian viruses caused early and extensive apoptosis (by 6 h of infection) resulting in reduced virus progeny and moderated pro- inflammation. Full length viral PB1-F2 present only in avian influenza viruses is a virulence factor that targets AM for mitochondrial associated apoptotic cell death. With the use of reverse genetics on an avian H5N1 virus, we found that full length PB1-F2 contributed to increased apoptosis and pro-inflammation but not to reduced virus replication. Taken together, we propose that early apoptosis of PAM limits the spread of avian influenza viruses and that PB1-F2 could play a contributory role in the process

Multitargeted Low-Dose GLAD Combination Chemoprevention: A Novel and Promising Approach to Combat Colon Carcinogenesis

AbstractPreclinical studies have shown that gefitinib, licofelone, atorvastatin, and α-difluoromethylornithine (GLAD) are promising colon cancer chemopreventive agents. Because low-dose combination regimens can offer potential additive or synergistic effects without toxicity, GLAD combination was tested for toxicity and chemopreventive efficacy for suppression of intestinal tumorigenesis in adenomatous polyposis coli (APC)Min/+ mice. Six-week-old wild-type and APCMin/+ mice were fed modified American Institute of Nutrition 76A diets with or without GLAD (25 + 50 + 50 + 500 ppm) for 14 weeks. Dietary GLAD caused no signs of toxicity based on organ pathology and liver enzyme profiles. GLAD feeding strongly inhibited (80–83%, P < .0001) total intestinal tumor multiplicity and size in APCMin/+ mice (means ± SEM tumors for control vs GLAD were 67.1 ± 5.4 vs 11.3 ± 1.1 in males and 72.3 ± 8.9 vs 14.5 ± 2.8 in females). Mice fed GLAD had >95% fewer polyps with sizes of >2 mm compared with control mice and showed 75% and 85% inhibition of colonic tumors in males and females, respectively. Molecular analyses of polyps suggested that GLAD exerts efficacy by inhibiting cell proliferation, inducing apoptosis, decreasing β-catenin and caveolin-1 levels, increasing caspase-3 cleavage and p21, and modulating expression profile of inflammatory cytokines. These observations demonstrate that GLAD, a novel cocktail of chemopreventive agents at very low doses, suppresses intestinal tumorigenesis in APCMin/+ mice with no toxicity. This novel strategy to prevent colorectal cancer is an important step in developing agents with high efficacy without unwanted side effects