8 results on '"Ayyildiz M"'
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2. The Effect of Book Preconditioning on Page-Turning Success Rate during Automated Book Digitization
- Author
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Sinmaz, E. K., Kocaseçer, M., and Ayyildiz, M.
- Published
- 2022
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- View/download PDF
3. Magnetic Field-Induced Martensitic Phase Transition in Cr-Substituted Ni–Mn–Sb + B Shape Memory Alloys
- Author
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Ayyildiz, M., primary, Kirat, G., additional, and Aksan, M. A., additional
- Published
- 2023
- Full Text
- View/download PDF
4. The Role of Acetylcholinesterase Enzyme Inhibitor Rivastigmine on Spike-Wave Discharges, Learning-Memory, Anxiety, and TRPV1 Channel Expression in Genetic Absence Epileptic WAG/Rij Rats.
- Author
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Türkdönmez Ak E, Okuyucu B, Arslan G, Ağar E, and Ayyildiz M
- Subjects
- Animals, Male, Rats, Memory drug effects, Maze Learning drug effects, TRPV Cation Channels genetics, TRPV Cation Channels metabolism, Rats, Wistar, Anxiety drug therapy, Epilepsy, Absence drug therapy, Epilepsy, Absence genetics, Cholinesterase Inhibitors pharmacology, Cholinesterase Inhibitors therapeutic use, Rivastigmine pharmacology, Rivastigmine therapeutic use
- Abstract
In the present study, the effects of the acetylcholinesterase (AChE) enzyme inhibitor rivastigmine (RIVA) on spike-wave discharges (SWDs), memory impairment, anxiety-like behavior, and the transient receptor potential vanilloid 1 (TRPV1) gene expression were investigated in genetic absence epileptic Wistar Albino Glaxo/Rijswijk (WAG/Rij) rats. After tripolar electrodes were implanted on the WAG/Rij rats' skulls, single doses of 0.125, 0.25, 0.5, 1, and 2 mg/kg RIVA were intraperitoneally (i.p.) administered, and electrocorticogram (ECoG) recordings of SWDs were recorded for three hours before and after injections. Additionally, once significant doses were determined in acute studies, WAG/Rij rats were administered low-dose (0.5 mg/kg) and high-dose (2 mg/kg) of RIVA for 21 consecutive days and SWDs were recorded. Learning-memory abilities (Y-maze test), anxiety-like behavior (elevated plus maze test), and TRPV1 gene expression were determined and compared in 8-month-old WAG/Rij and age-matched Wistar rats. Acute RIVA administration dose-dependently reduced the total number of SWDs and was even entirely inhibited at 1 and 2 mg/kg RIVA doses. On the other hand, long-term high-dose RIVA administration increased the total number of SWDs. Long-term high-dose RIVA treatment reduced learning-memory and anxiety-like behavior in WAG/Rij rats, while only anxiety-like behavior decreased in Wistar rats. TRPV1 gene expression increased in WAG/Rij rats and decreased in Wistar rats with long-term RIVA administration. These data indicate that the sudden increase of acetylcholine (ACh) causes a significant decrease in absence seizures. In contrast, prolonged maintenance of ACh elevation causes an increase in absence seizures, probably by altering the expression of channels such as TRPV1., Competing Interests: Declarations. Competing Interests: The authors declare no competing interests. Ethics Approval: The study was performed by the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. The experimental protocol was approved by Ondokuz Mayıs University Animal Experiments Local Ethics Committee (Approval No: 2022/08)., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
- Published
- 2025
- Full Text
- View/download PDF
5. Effective drug design screening in bacterial glycolytic enzymes via targeting alternative allosteric sites.
- Author
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Turkmenoglu I, Kurtulus G, Sesal C, Kurkcuoglu O, Ayyildiz M, Celiker S, Ozhelvaci F, Du X, Liu GY, Arditi M, and Akten ED
- Subjects
- Glycolysis drug effects, Bacterial Proteins antagonists & inhibitors, Bacterial Proteins metabolism, Bacterial Proteins chemistry, Pyruvate Kinase metabolism, Pyruvate Kinase antagonists & inhibitors, Pyruvate Kinase chemistry, Enzyme Inhibitors pharmacology, Enzyme Inhibitors chemistry, Humans, Drug Evaluation, Preclinical methods, Allosteric Site, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Staphylococcus aureus enzymology, Staphylococcus aureus drug effects, Drug Design, Molecular Docking Simulation
- Abstract
Three glycolytic enzymes phosphofructokinase (PFK), glyceraldehyde-3-phosphate dehydrogenase (GADPH) and pyruvate kinase (PK) that belong to Staphylococcus aureus were used as targets for screening a dataset composed of 7229 compounds of which 1416 were FDA-approved. Instead of catalytic sites, evolutionarily less conserved allosteric sites were targeted to identify compounds that would selectively bind the bacteria's glycolytic enzymes instead of the human host. Seven different allosteric sites provided by three enzymes were used in independent screening experiments via docking. For each of the seven sites, a total of 723 compounds were selected as the top 10 % which displayed the highest binding affinities. All compounds were then united to yield the top 54 drug candidates shared by all seven sites. Next, 17 out of 54 were selected and subjected to in vitro experiments for testing their inhibition capability for antibacterial growth and enzymatic activity. Accordingly, four compounds displaying antibacterial growth inhibition above 40 % were determined as Candesartan cilexetil, Montelukast (sodium), Dronedarone (hydrochloride) and Thonzonium (bromide). In a second round of experiment, Candesartan cilexetil and Thonzonium displayed exceptionally high killing efficiencies on two bacterial strains of S.aureus (methicillin-sensitive and methicillin-resistant) with concentrations as low as 4 μg/mL and 0.5 μg/mL. Yet, their enzymatic assays were not in accordance with their killing effectiveness. Different inhibitory effects was observed for each compound in each enzymatic assay. A more effective target strategy would be to screen for drug compounds that woud inhibit a combination of glycolytic enzymes observed in the glycolytic pathway., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2024
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6. Nesfatin‑1 exerts anticonvulsant effect by reducing oxidative stress in experimental epilepsy model.
- Author
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Musuroglu Keloglan S, Aycik FB, Kocacan SE, Yazgan B, Ayyildiz M, and Agar E
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- Rats, Animals, Rats, Wistar, Superoxide Dismutase metabolism, Oxidative Stress, Glutathione Peroxidase metabolism, Glutathione metabolism, Penicillins pharmacology, Anticonvulsants pharmacology, Anticonvulsants therapeutic use, Epilepsy chemically induced, Epilepsy drug therapy
- Abstract
Neuropeptides play an important role in the pathogenesis of epilepsy. In the present study, the effect of nesfatin‑1, a neuropeptide, was investigated on penicillin‑induced epilepsy model. Epileptiform activity was induced by an injection of penicillin into the somatomotor cortex at 56 albino Wistar rats. Nesfatin‑1 (i.c.v.) was administered at five different doses (12.5, 25, 50, 100, and 200 pmol) 30 min after a penicillin administration. Astressin 2B, a corticotropin‑releasing factor (CRF) receptor antagonist, was administered 10 minutes later the effective dose of nesfatin‑1 (50 pmol, i.c.v.). Superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR) and malondialdehyde (MDA) levels in cerebrum were analysed by ELISA method. Nesfatin‑1, at the doses of 25, 50 and 100 pmol, significantly reduced the frequency of epileptiform activity. However, none of the doses of nesfatin‑1 had any effect on the amplitude of epileptiform activity. Astressin 2B alone did not show any effect on epileptiform activity. In addition, astressin 2B had no effect on the anticonvulsant effect of nesfatin‑1. Nesfatin‑1 (at the doses of 25, 50, 100 pmol) did not alter SOD and GSH levels, but significantly increased the GPx and GR levels. Nesfatin‑1 (at a dose of 50 pmol) significantly decreased the MDA level in the cerebrum. Nesfatin‑1 shows anticonvulsant effect and astressin 2B did not affect the anticonvulsant effect of nesfatin‑1. We suggest that nesfatin‑1 has oxidative stress‑mediated anticonvulsant effect in the penicillin‑induced epileptic activity.
- Published
- 2023
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7. The electrophysiological and behavioral evaluation of the peptide hemopressin and cannabinoid CB1 receptor agonist and antagonist in pentylenetetrazol model of epilepsy in rats.
- Author
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Al-Kaleel A, Aygun H, Al-Gailani L, Kabak Y, Inal S, Ayyildiz M, Him A, and Agar E
- Subjects
- Animals, Rats, Male, Cannabinoid Receptor Agonists pharmacology, Cannabinoid Receptor Agonists therapeutic use, Anticonvulsants pharmacology, Anticonvulsants therapeutic use, Pentylenetetrazole pharmacology, Receptor, Cannabinoid, CB1, Rats, Wistar, Hemoglobins, Dose-Response Relationship, Drug, Epilepsy chemically induced, Epilepsy drug therapy, Cannabinoids
- Abstract
This study endeavoured to assess the effect of hemopressin (Hp), a nano peptide obtained from the alpha chain of hemoglobin, on chronic epileptic activity and its potential correlation with cannabinoid receptor type 1 (CB1). Male Wistar albino rats (230-260 g) were used. The kindling process was conducted by administering a sub-convulsant dose of pentylenetetrazol (PTZ) (35 mg/kg, i.p) three times a week for a maximum of 10 weeks. Tripolar electrodes and external cannula guides for intracerebroventricular (i.c.v) injections were surgically implanted in the skulls of kindled rats. On the day of the experiment, doses of Hp, AM-251, and ACEA were administered prior to the PTZ injections. Electroencephalography recordings and behavioural observations were conducted simultaneously for 30 min after the PTZ injection. The administration of Hp (0.6 μg, i.c.v) resulted in a decrease in epileptic activity. The CB1 receptor agonist ACEA (7.5 μg, i.c.v) showed an anticonvulsant effect, but the CB1 receptor antagonist AM-251 (0.5 μg, i.c.v) displayed a proconvulsant effect. The co-administration of Hp (0.6 μg, i.c.v) and ACEA (7.5 μg, i.c.v) and of Hp (0.6 μg, i.c.v) and AM-251 (0.5 μg, i.c.v) produced an anticonvulsant effect. However, when AM-251 was administered prior to Hp, it produced a proconvulsant impact that overrode Hp's intended anticonvulsant effect. Interestingly, the co-administration of Hp (0.03 μg) + AM-251 (0.125 μg) unexpectedly exhibited an anticonvulsant effect. Electrophysiological and behavioural evaluations demonstrated the anticonvulsant effect of Hp in the present model, highlighting the possibility that Hp may act as an agonist for the CB1 receptor., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2023
- Full Text
- View/download PDF
8. The effect of vitamin E supplementation on brain tissue element levels in epileptic rats.
- Author
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Ozturk-Sonmez L, Tutkun E, Agar E, Ayyildiz M, Mogulkoc R, and Baltaci AK
- Subjects
- Animals, Brain, Dietary Supplements, Male, Penicillins pharmacology, Rats, Vitamin E pharmacology, Zinc metabolism, Zinc pharmacology, Epilepsy drug therapy, Epilepsy metabolism
- Abstract
The aim of this study was to investigate how the application of vitamin E affected the levels of chemical elements in the brain tissues of epilepsy-induced rats. The sample of 40 adult male rats was separated into 4 equal groups: Group 1: control, Group 2: vitamin E; Group 3: penicillin to promote epileptic form activity and Group 4: penicillin + vitamin E. After three months of treatment, an Atomic Absorption Spectrophotometer was used to analyze the presence of the elements in brain tissue sections (brain, brainstem, cerebellum) of the decapitated animals. The levels of magnesium in the groups that received vitamin E (G2 and 4) were significantly higher than in the control group (G1) and the first epilepsy group (G3) (p.05).Chrome and zinc levels in brain, brainstem, and cerebellum tissue of the two epilepsy groups (G3-4) decreased significantly compared to the control group (G1) and the vitamin E group (G2) (p.05). The levels of copper in the brainstem and lead in the cerebellum of the first epilepsy group (G3) were higher than in all other groups (p.05). The findings showed that the application of vitamin E in experimental epilepsy may have a limited effect on element metabolism in brain tissue. A decline in zinc levels in the brain, brainstem and cerebellum tissues in epilepsy groups constitutes another result of our study. This should be examined further to determine whether decreased levels of zinc play a role in epilepsy pathogenesis.
- Published
- 2022
- Full Text
- View/download PDF
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