47 research outputs found

    Olaparib significantly delays photoreceptor loss in a model for hereditary retinal degeneration

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    The enzyme poly-ADP-ribose-polymerase (PARP) mediates DNA-repair and rearrangements of the nuclear chromatin. Generally, PARP activity is thought to promote cell survival and in recent years a number of PARP inhibitors have been clinically developed for cancer treatment. Paradoxically, PARP activity is also connected to many diseases including the untreatable blinding disease Retinitis Pigmentosa (RP), where PARP activity appears to drive the pathogenesis of photoreceptor loss. We tested the efficacy of three different PARP inhibitors to prevent photoreceptor loss in the rd1 mouse model for RP. In retinal explant cultures in vitro, olaparib had strong and long-lasting photoreceptor neuroprotective capacities. We demonstrated target engagement by showing that olaparib reduced photoreceptor accumulation of poly-ADP-ribosylated proteins. Remarkably, olaparib also reduced accumulation of cyclic-guanosine-monophosphate (cGMP), a characteristic marker for photoreceptor degeneration. Moreover, intravitreal injection of olaparib in rd1 animals diminished PARP activity and increased photoreceptor survival, confirming in vivo neuroprotection. This study affirms the role of PARP in inherited retinal degeneration and for the first time shows that a clinically approved PARP inhibitor can prevent photoreceptor degeneration in an RP model. The wealth of human clinical data available for olaparib highlights its strong potential for a rapid clinical translation into a novel RP treatment.Peer reviewe

    Ammonium Fixation and Its Relationship To Important Characteristics of Some Aegean Soils

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    WOS: A1989CB3220000

    Performance based design using life cycle cost analysis

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    Life cycle cost analyses is one of the useful tool for evaluating the lifespan performance of buildings. The sum of initial and future costs associated with the construction and operation of a building over a period of life time is determined by life cycle cost analysis. In this study, a moment-resisting steel building is designed using various base shear values and the life cycle cost of each design is determined for different earthquake intensities. Static pushover analysis is used to calculate yield base shear value of each design and initial costs, the cost of the expected damages caused by earthquakes that are expected to occur during the design life of the buildings are estimated. The optimum economic design of the steel building is determined by using yield base shear and total cost values

    Energy consumption of RC buildings during their life cycle

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    Studies on the total energy use during the life cycle of reinforced concrete buildings are desirable, considering the urgent necessity to save energy. Life cycle of buildings includes different phases which are the manufacture of the building materials, transportation, construction of the building, occupancy, renovation, demolition and removal of the materials from debris. However, there have been few studies are on the total energy use during the life cycle of buildings. Researches are mainly focused oil the energy use for buildings during their period of use. In the present study, the total energy use of ordinary reinforced concrete buildings in Izmir during their life cycle is investigated and their energy consumptions are calculated for all temporal phases separately

    Creep behaviour of plane frame structures made of GFRP profiles

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    A methodology is presented for analytical calculation of creep behavior of plane frames made of glass fiber reinforced polymer (GFRP) profiles and an experimental study is carried out in order to evaluate the analytical calculation results. In order to account nonlinear viscoelastic material behavior, stress - strain - time relationship of plane frame is given and creep behavior of plane frame structure is investigated. Material coefficients for the creep functions are determined using three point beam bending test results. In order to validate the analytical approach, a plane frame made of GFRP profiles is tested under sustained loads for 100 days and displacements, strains are monitored. Strain and displacement values that are calculated using analytical method show good agreement with the full-scale test data
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