Fatih Sefil

Gap junctions play an important role in the synchronized neuronal discharges. The main reason of the epileptic seizures is disruption of this synchronization. Therefore, the aim of the present study is to explore the combination valproic acid with carbenoxolone in pentylenetetrazole-kindled rats. In the first set of experiments, pentylenetetrazole (35 mg/kg intraperitoneally was administered to the rats to produce the kindling and then permanent screw electrodes to record electroencephalographic signals. The kindled rats were divided into six groups. While electroencephalographic recordings received from animals, behavioral evaluation was done by an observer. The data analysis was performed using T test and Mann-Whitney U tests. The dose of 40 mg/kg carbenoxolone was the most effective in carbenoxolone treatment groups. It prevented generalized seizures by 50%, reduced seizure stage, seizure duration and spike frequency. There was no significant difference between carbenoxolone-valproic acid combination and valproic acid on any seizure parameters. The current study is the first study which shows the interaction of carbenoxolone with valproic acid in pentylenetetrazole kindling model. As a result, carbenoxolone-valproic acid combination was not more effective than the standalone use of these drugs.

Atypical antipsychotics have been used to treat fear and anxiety disturbance that are highly common in schizophrenic patients. It is suggested that disruptions of N-methyl-d-aspartate (NMDA)-mediated transmission of glutamate may underlie the pathophysiology of schizophrenia. The present study was conducted to analyze the effectiveness of clozapine on the anxiety-related behavior and locomotor function of the adult brain, which had previously undergone NMDA receptor blockade during a developmental period. In order to block the NMDA receptor, male mice were administered 0.25 mg/kg of MK-801 on days 7 to 10 postnatal. In adulthood, they were administered intraperitoneally 0.5 mg/kg of clozapine and tested with open-field and elevated plus maze test, to assess their emotional behavior and locomotor activity. In the group receiving MK-801 in the early developmental period the elevated plus maze test revealed a reduction in the anxiety-related behavior (p<0.05), while the open-field test indicated a decrease in locomotor activity (p<0.01). Despite these reductions, clozapine could not reverse the NMDA receptor blockade. Also, as an atypical antipsychotic agent, clozapine could not reverse impairment in the locomotor activity and anxiety-related behavior, induced by administration of the MK-801 in neonatal period.

The object of the study is to experimentally investigate the possible systemic side effects of Oxymetazoline including its nasal spray which has been in use for a long time both by the physicians and patients. There is no study in the literature to address the damages of oxymetazoline on the end organ. The study conducted on 2 groups of rat. Group 1 (n = 8): Control; and Group 2 (n = 8): Oxymetazoline. During 4 week, the control group was applied with 2 drops of saline water on each nasal cavity 3 times a day and the other group was applied with 2 drops of oxymetazoline HCl 3 times a day. At the end of experiment, samples from mandible, parotid and tails of the rats were taken in 10% formalin for histopathological investigations. In histopathological experiments, when compared with the control group, the oxymetazoline group showed significant increase in many of the histopathological parameters (ischemic changes: P = 0.0001; congestion: P = 0.0006; arterial thrombosis: P = Ns; PNL accumulations: P = 0.001; necrosis: P = 0.0001; and ulceration: P = 0.014). The results of histopathologic tests on the samples taken from mandible and parotid gland, in comparison with the control group, showed no significant increase (focal inflammation: P = Ns; and lymphocyte aggregation: P = Ns). Due to the damage that the long-term use of nasal spray including oxymetazoline, it may cause injury on the end organ, which we revealed in our histopathological experiments. We believe that it's essential for the physicians to provide information on the side effects of the medicine to their patients who use for a long term.

Amaç: Motor ve Duysal sinir lifleri bir potasyum kanal blokörü olan 4-Aminopiridine karşı (4-AP) farklı yanıt verebilirler. Bu çalışmadaki amacımız sıçan ventral ve dorsal arka kök aksonlarının elektrofizyolojik özelliklerini 4-AP ve Birleşik Sinir Aksiyon Potansiyelleri (BSAP) aracılığı ile araştırmaktır.Materyal-Metod: Wistar türü erkek sıçanlar ether anestezisi altında karotoid arter kesisi ile hızlı bir şekilde sakrifiye edildi. Lumbar (L-4) ventral ve dorsal kök aksonları laminektomi yöntemi ile hızlıca çıkarılıp 95% 02+5% CO2 ile gazlandırılan soğuk Krebs içine alındı. 4-AP etkisini değerlendirmek için BSAP kayıtları modifiye sukroz-gap aparatı ile in vitro olarak ölçüldü. Tüm deneyler 20-22 oC yürütüldü.Bulgular: Ventral köklerden kayıtlanan BSAP toplam süresi 4-AP uygulaması ile uzadı ve dinlenim değerine dönmesi gecikti. Dorsal köklerde ise toplam BSAP süresi ventral köklere göre en az iki kat daha fazla uzadı. Ayrıca dorsal köklerde 4-AP sonrası dinlenim değerine dönerken belirgin bir hump (hörgüç) gözlendi. Bu fenomen ventral köklerde görülmedi. Ventral ve dorsal köklerden kayıtlanan BSAP latansları sırasıyla 256 ± 24 ve 508 ± 69 μs, iletim hızı ise 20,4 ± 2,4 ve 10,8 ± 1,4 m/s olarak ölçüldü.Sonuç: Bu çalışmada sıçan motor ve duysal aksonları üzerine 4-AP’nin çok farklı etkilere sahip olduğunu gösterdik. Motor ve duysal sinir lifleri üzerine 4-AP’nin farklı etkileri, bu sinirlerde bulunan miyelinli-myelinsiz akson oranlarının ve akson çaplarının farklı olmalarından kaynaklanabilir. İlave olarak ventral ve dorsal kök aksonlarında nod veya paranodda bulunan potasyum-sodyum kanal farklılığından kaynaklanabilir.

The aim of this study was to investigate the effects of levetiracetam (LEV) on penicillin-induced epileptiform activity in rats. Penicillin was applied intracerebroventricularly (icv) at a dose of 500 IU to induce epileptiform activity. LEV was given intraperitoneally (ip) at doses of 20, 40, 80 mg/kg before penicillin injection. This agent reduced epileptiform activity by decreasing spike frequencies. The mean spike frequencies decreased significantly in all the LEV treated groups. There was no significant change in the spike amplitudes of the LEV groups compared with the control group. 40 mg/kg of LEV was determined as the most effective dose on reducing epileptiform activity. The results of this study suggest that LEV is an effective antiepileptic agent in penicillin-induced epilepsy.

The aim of the study to elicit effects of pure quercetin in pentylenetetrazole (PTZ) and picrotoxin induced seizures. Each animal group was divided into six groups and composed of six rats. Rats were assigned to the following experiments and groups (G): (G1) PTZ 45 mg/kg + DMSO; (G2) PTZ 45 mg/kg + 5 mg/kg quercetin; (G3) PTZ 45 mg/kg + 10 mg/kg quercetin; (G4) PTZ 45 mg/kg + 20 mg/kg quercetin; (G5) PTZ 45 mg/kg + 40 mg/kg quercetin; (G6) Picrotoxin 5 mg/kg + DMSO; (G7) Picrotoxin 5 mg/kg + 10 mg/kg quercetin; (G8) Picrotoxin 5 mg/kg + 20 mg/kg quercetin. In all groups quercetin were injected 30 min before PTZ and picrotoxin applications. Compared to PTZ, quercetin significantly prolonged onset of the seizure in 10 mg/kg (P < 0.05) and reduced the seizure stage in 10 mg/kg quercetin injected group (P < 0.01). Compared to PTZ, quercetin also declined the generalized seizure duration at 10 mg/kg (P < 0.01) and 20 mg/kg (P < 0.05) doses. At the doses of 5 mg/kg and 40 mg/kg quercetin there were no significant changes in seizure parameters. Development of picrotoxin induced seizures is slower than in PTZ. Quercetin was found to be unable to prevent seizure in picrotoxin induced seizures. Surprisingly, quercetin also significantly reduced the onset of seizures at the dose of 20 mg/kg (P < 0.05). quercetin (at doses of 10 and 20 mg/kg i.p) prevented seizures in PTZ (45 mg/kg i.p) induced seizures. Especially, 10 mg/kg PTZ prolonged onset of seizures, reduced the seizure duration and seizure severity score in comparison with control group. At a higher (40 mg/kg) dose quercetin failed to prevent PTZ induced seizures. In addition 20 mg/kg quercetin significantly reduced the onset of seizures that suggest a preconvulsive effect. 20 mg/kg quercetin reduced the onset of picrotoxin induced seizures. In picrotoxin model, it may be claimed that quercetin at higher doses accelerate the epileptic activity owing to its antagonistic effect on GABAA. Further investigations are needed to explore the mechanisms of the antiepileptic and preconvulsant effects of quercetin.

OBJECTIVE: The development of secondary brain injury after trauma is known to involve in many cellular mediators. The aim of the study was to evaluate and compare the effects of the use of both methylprednisolone and montelukast on serum and tissue concentrations of NO, malondialdehyde (MDA) levels, superoxide dismutase (SOD) activity, and tissue glutathione peroxidase (GSH-Px) activity in rats with spinal cord injury (SCI). MATERIALS AND METHODS: SCI was induced in Wistar albino rats by dropping a 10 g rod from a 5.0 cm height at T9-10. The 28 rats were randomly divided into four equal groups: montelukast, methylprednisolone, non-treatment and sham groups. Rats were neurologically tested at 24 hours after trauma and spinal cord tissue levels of MDA, SOD, GSH-PX, CAT levels and blood CK, CK-BB, LDH levels were measured. In addition, histopathological changes were also examined. RESULTS: There was a significant improvement in Tarlov scores in methylprednisolone and montelukast administered group compared to the trauma group (p = 0.001). When compared to trauma group, methylprednisolone and montelukast groups had significant differences in MDA (p < 0.05), SOD (p < 0.001), CK-BB (p < 0.001) and LDH (p < 0.05) levels. Histopathologically, no significant changes were observed. CONCLUSIONS: The present study shows effects of montelukast with biochemical and histopathological parameters and compares its effects with those of methylprednisolone for the first time. Our research has shown that montelukast and methylprednisolone have a neuroprotective effect on spinal cord injury.

Platelets have an important role in atherosclerosis and arterial thrombosis. Cardiovascular complication prevalence of type 2 diabetes mellitus (type 2 DM) may be associated with glycosylated hemoglobin (HbA1c) and mean platelet volume (MPV). The aim of the study was to investigate if platelets were activated in diabetes and its associated vascular complications by measuring the MPV in the diabetics compared to the non-diabetics, and to determine the correlation of MPV with fasting serum glucose (FSG), HbA1c and duration of diabetes in the diabetic patients, respectively. The study carried out in 65 patients with type 2 DM and 40 non-diabetic subjects. In addition to non-diabetic patients, all diabetic patients were divided into two groups according to their HbA1c levels: group A consisted of patients with HbA1c levels ≤7% and group B consisted of patients with HbA1c levels >7%. MPV was significantly higher in Group B as compared to both non-diabetics and Group A. MPV had a high positive correlation with HbA1c and FSG, as with diabetes duration. It is found that MPV was increased in type 2 DM. Our findings suggested an association between MPV and HbA1c. Therefore, MPV would be a beneficial prognostic marker of cardio-vascular complications in patients with type 2 DM.