SOD activity of immobilized enzyme mimicking complexes

A binuclear, imidazolato-bridged, possible superoxide dismutase-mimicking complex (Cu(II)-diethylenetriamino-μ-imidazolato-Zn(II)-tris-aminoethylamine-triperchlorate) was prepared and immobilized on silica gel or among the layers of montmorillonite. The superoxide dismutase (SOD) activity of the complex before and after immobilization was studied by a SOD assay. It was found that the SOD activity of the host-free complex decreased somewhat when montmorillonite was the host, however, using silica gel as host it increased

The synthesis and the catalytic (catalase and tyrosinase) activities of amino acid copper complexes covalently grafted onto silica gel

In this work the synthesis, structure and certain catalytic properties of amino acid copper complexes covalently grafted onto silica gel are described. The following enzyme mimicking complexes were synthesized and characterised by experimental (FT-IR) and computational (mainly MM+) methods: BOC-His-Cu/silica gel, BOC-Tyr-Cu/silica gel, His-OMe-Cu/silica gel, Tyr-OMe-Cu/silica gel, H-His-Cu/silica gel, H-Tyr-Cu/silica gel His-OH-Cu/silica gel and Tyr-OH-Cu/silica gel. The activities of these substances were also tested in the decomposition of hydrogen peroxide. The majority of the substances proved to be good enzyme mimics displaying either catalase or tyrosinase activity

Planning activity for internally generated reward goals in monkey amygdala neurons.

The best rewards are often distant and can only be achieved by planning and decision-making over several steps. We designed a multi-step choice task in which monkeys followed internal plans to save rewards toward self-defined goals. During this self-controlled behavior, amygdala neurons showed future-oriented activity that reflected the animal's plan to obtain specific rewards several trials ahead. This prospective activity encoded crucial components of the animal's plan, including value and length of the planned choice sequence. It began on initial trials when a plan would be formed, reappeared step by step until reward receipt, and readily updated with a new sequence. It predicted performance, including errors, and typically disappeared during instructed behavior. Such prospective activity could underlie the formation and pursuit of internal plans characteristic of goal-directed behavior. The existence of neuronal planning activity in the amygdala suggests that this structure is important in guiding behavior toward internally generated, distant goals

Cyclophosphamid kezelés különböző módszereivel, valamint Adriablastina és Cyclophosphamid egyidejü alkalmazásával elért eredményeinek összehasonlitása a petefészekrák gyógyitásában

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Cognitive Enhancer Effects of Low Memantine Doses Are Facilitated by an Alpha7 Nicotinic Acetylcholine Receptor Agonist in Scopolamine-Induced Amnesia in Rats

Alpha7 nicotinic acetylcholine receptors (nAChRs) play an important role in learning and memory and are promising targets for pharmacological cognitive enhancement. Memantine, an approved substance for Alzheimer’s disease treatment, is an antagonist of the N-Methyl-D-aspartate receptor (NMDAR) and also acts as an alpha7 nAChR antagonist. Here, we tested the interaction between an alpha7 nAChR agonist (PHA-543613) and memantine. Efficacy of memantine, PHA-543613, and their co-administration were investigated on the spatial working memory of rats using the spontaneous alternation paradigm in T-maze. Scopolamine-induced transient amnesia was used to model cognitive impairment. First, the dose-response relationship was assessed for memantine, and its lowest effective dose was found to be 0.1 mg/kg. Then, co-administration treatments with subeffective doses of the alpha7 nAChR agonist PHA-543613 and different doses of memantine were tested. The co-administration of subeffective drug doses significantly improved memory performance of the rats and reversed scopolamine-induced deficits. Interestingly, a higher than effective (0.3 mg/kg) dose of memantine did not increase performance in monotreatment, only in co-administration with PHA-543613. However, the co-administration of PHA-543613 did not further increase the efficacy of the previously effective monotreatment doses of memantine. Thus, the efficacy of memantine monotreatment and its co-administration with PHA-543613 converged to create a common ceiling effect, with an additive interaction found in the behavioral effects. These results suggest that memantine and PHA-543613 may exert their cognitive enhancer effects on the same target, possibly on the alpha7 nAChRs. Results also suggest possible benefits of a combination therapy with memantine and alpha7 nAChR agonists