Ahmet Ak
Selçuk University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Ahmet Ak.
Journal of Neurosurgical Anesthesiology | 2001
Mehmet Erkan Ustun; Ates Duman; Cemile Oztin Ogun; Hüsamettin Vatansev; Ahmet Ak
To examine the effects of calcium antagonists nimodipine and magnesium sulfate (MgSO4) on tissue endogenous antioxidant levels, the authors studied superoxide dismutase (SOD) and glutathione peroxidase (GPx) levels in rabbit brain 1 hour after experimental head trauma. Forty New Zealand rabbits were anesthetized and randomly divided into four groups. Group 1 (n = 10) was the sham operated group. Group 2 (n = 10), the control group, received head trauma and no treatment. Group 3 (n = 10) received head trauma and intravenous (IV) 2 &mgr;gr/kg nimodipine. Group 4 (n = 10) received head trauma and IV 100 mg/kg MgSO4. Head trauma was delivered by performing a craniectomy over the right hemisphere and dropping a weight of 20 g from a height of 40 cm. In the right (traumatized) hemisphere, SOD and GPx decreased by 57.60% ± 9.60% and 72.93% ± 5.51% respectively from sham values. Magnesium sulfate, but not nimodipine, reduced the magnitude of decrease of SOD and GPx to 19.43% ± 7.15% and 39.01% ± 7.92% respectively from sham values. In the left (nontraumatized) hemisphere, MgSO4 increased SOD to 42.43% ± 24.76% above sham values. The authors conclude that MgSO4 treatment inhibited the decrease in SOD and GPx levels in experimental brain injury.
Neurology India | 2006
Aysegul Bayir; Erdal Kalkan; Sedat Kocak; Ahmet Ak; Basar Cander; Said Bodur
AIMS To determine the usefulness of fibrinolytic markers as early prognostic indicators in patients with isolated head trauma. MATERIALS AND METHODS Sixty-two consecutive patients (26 women and 36 men; mean age 61 years, range 2-76 years) with isolated head trauma seen within the first three hours of the trauma were included in the study. The Glasgow Coma score (GCS), platelet counts (Plt), prothrombin time (PT), partial thromboplastin time (PTT), fibrinogen, fibrin degradation products (FDP) and D-dimer levels were measured. Head computerized tomography (CT) findings were categorized as brain edema, linear fracture, depressed fracture, contusion and bleeding. Plt counts, PT, PTT, fibrinogen, FDP, D-dimer levels and CT findings were compared with both GCS and mortality in the first week. Statistical significance was accepted at P <or=0.05. RESULTS A marked negative relationship was found between GCS and PT, PTT, FDP and D-dimer levels (P < 0.001). Plt levels did not correlate with GCS. Mortality was most strongly related to GCS, PT, FDP and D-dimer levels (P < 0.001, P < 0.001, P < 0.001 and P < 0.001, respectively). We found no relationship between mortality and CT findings, nor was there any significant relationship between Plt, PTT and fibrinogen levels. CONCLUSION GCS and fibrinolytic markers measured within the first three hours were useful in determining the prognosis of patients with isolated head trauma.
Pakistan Journal of Medical Sciences | 1969
Hasan Kara; Aysegul Bayir; Ahmet Ak; Selim Degirmenci; Murat Akinci; Ahmet Agacayak; Emine Marcil; Melih Azap
Objective: The frequency of hemolysis of blood samples may be increased by transport in a pneumatic tube system. The purpose of this study was to evaluate the effect of pneumatic tube system transport on hemolysis of blood samples. Methods: Blood samples were transported from the emergency department to the hospital laboratory manually by hospital staff (49 patients) or with a pneumatic tube system (53 patients). The hemolysis index and serum chemistry studies were performed on the blood samples and compared between the different methods of transport. Results: The blood samples that were transported by the pneumatic tube system had a greater frequency of hemolysis and greater mean serum potassium and median creatinine, aspartate aminotransferase, and lactate dehydrogenase levels than samples transported manually. Conclusion: Blood samples transported from the emergency department to the hospital laboratory by a pneumatic tube system may have a greater frequency of hemolysis than samples transported manually. This may necessitate repeat phlebotomy and cause a delay in completing the laboratory analysis.
Neuropsychiatric Disease and Treatment | 2014
Hasan Kara; Murat Akinci; Selim Degirmenci; Aysegul Bayir; Ahmet Ak; Alaaddin Nayman; Ali Unlu; Fikret Akyurek; Mesut Sivri
Background Serum biomarkers may be useful for early diagnosis of acute ischemic stroke, exclusion of other diseases that may mimic stroke, and prediction of infarct volume. We evaluated serum high-sensitivity C-reactive protein (hs-CRP) and lipoprotein-related phospholipase A2 (Lp-PLA2) in patients who had acute ischemic stroke. Methods In 200 patients who presented to an emergency service (acute ischemic stroke, 102 patients; control with no stroke, 98 patients), stroke patients were evaluated with the Canadian neurological scale and diffusion-weighted magnetic resonance imaging, and all patients were evaluated with the Glasgow coma scale and their serum hs-CRP level and Lp-PLA2 activity were assessed. The volume of stroke lesions was calculated from magnetic resonance images. Results Patients who had stroke had higher mean serum hs-CRP level (stroke, 7±6 mg/dL; control, mean ± standard deviation 1±1 mg/dL; P≤0.001) and Lp-PLA2 activity (stroke, mean ± standard deviation 113±86 nmol/min/mL; control, mean ± standard deviation 103±50 nmol/min/mL; P≤0.001) than control patients who did not have stroke. The mean hs-CRP level and Lp-PLA2 activity were higher in patients who had greater stroke severity (lower Canadian neurological scale score) and were higher in patients who had larger volume strokes. Conclusion Higher hs-CRP level and Lp-PLA2 activity are significantly associated with more severe neurologic impairment and larger infarct size in patients who have acute ischemic stroke. These biomarkers may be useful for rapid diagnosis and prediction of ischemic tissue volume in the early stage of ischemic stroke. These findings may be important for health care facilities that have limited access to emergency computed tomography scanning for the diagnosis of stroke.
Neuropsychiatric Disease and Treatment | 2015
Hasan Kara; Selim Degirmenci; Aysegul Bayir; Ahmet Ak; Murat Akinci; Ali Dogru; Fikret Akyurek; Seyit Ali Kayis
Objectives The purpose of the present study was to evaluate the association between the red blood cell distribution width (RDW) and the Glasgow Coma Scale (GCS), Canadian Neurological Scale (CNS), and National Institutes of Health Stroke Scale (NIHSS) scores in patients who had acute ischemic stroke. Methods This prospective observational cohort study included 88 patients who have had acute ischemic stroke and a control group of 40 patients who were evaluated in the Emergency Department for disorders other than acute ischemic stroke. All subjects had RDW determined, and stroke patients had scoring with the GCS, CNS, and NIHSS scores. The GCS, CNS, and NIHSS scores of the patients were rated as mild, moderate, or severe and compared with RDW. Results Stroke patients had significantly higher median RDW than control subjects. The median RDW values were significantly elevated in patients who had more severe rather than milder strokes rated with all three scoring systems (GCS, CNS, and NIHSS). The median RDW values were significantly elevated for patients who had moderate rather than mild strokes rated by GCS and CNS and for patients who had severe rather than mild strokes rated by NIHSS. The area under the receiver operating characteristic curve was 0.760 (95% confidence interval, 0.676–0.844). Separation of stroke patients and control groups was optimal with RDW 14% (sensitivity, 71.6%; specificity, 67.5%; accuracy, 70.3%). Conclusion In stroke patients who have symptoms <24 hours, the RDW may be useful in predicting the severity and functional outcomes of the stroke.
Clinical Interventions in Aging | 2013
Hasan Kara; Aysegul Bayir; Ahmet Ak; Murat Akinci; Necmettin Tufekci; Selim Degirmenci; Melih Azap
Purpose Trauma is a common cause of admission to the hospital emergency department. The purpose of this study was to evaluate the cause of admission, clinical characteristics, and outcomes of patients aged ≥65 years admitted to an emergency department in Turkey because of blunt trauma. Materials and methods Medical records were retrospectively reviewed for 568 patients (314 women and 254 men) aged ≥65 years who were admitted to an emergency department of a tertiary care hospital. Results Trauma was caused by low-energy fall in 379 patients (67%), traffic accident in 79 patients (14%), high-energy fall in 69 patients (12%), and other causes in 41 patients (7%). The most frequent sites of injury were the lower extremity, thorax, upper extremity, and head. The femur was the most frequent fracture site. After evaluation in the emergency department, 377 patients (66%) were hospitalized. There were 31 patients (5%) who died. Risk of hospitalization after trauma was significantly associated with trauma to the lower extremity, thorax, and spine; fractures of the femur and rib; and intracranial injury. Conclusion Emergency department admission after trauma in patients aged ≥65 years is common after low-energy falls, and most injuries occur to the extremities. It is important to focus on prevention of falls to decrease the frequency of trauma in the elderly.
Case Reports | 2013
Hasan Kara; Ahmet Ak; Aysegul Bayir; Ahmet Avci
Black widow spiders (Latrodectus tredecimguttatus) are poisonous spiders endemic in Turkey. Latrodectus bites may cause myocarditis with increased cardiac enzymes. We treated two men (aged 20 and 33 years) who had myocarditis after black spider bites with leucocytosis and elevated levels of troponin I, creatine kinase and creatine kinase-MB fraction. Both patients had normal results on an ECG, and one patient had abnormal echocardiography with minimal left ventricular wall movement disorder. Both patients were hospitalised in the intensive care unit and treated with intravenous fluids, analgesics, spasmolytic drugs, tetanus prophylaxis and cardiac monitoring. The levels of troponin I, creatine kinase and creatine kinase-MB fraction improved, and the patients were discharged home on the third and fifth hospital day without complications. Myocarditis after a Latrodectus bite is rare, but may be associated with serious complications. Therefore, in regions endemic with Latrodectus spiders, prudent treatment of spider bites may include cardiac evaluation and monitoring.
Journal of Neurosurgical Anesthesiology | 2007
ahka Lva Cengz; Ahmet Ak; Mehmet Erkan st n; Serdar Karak se
The role of lactate composition of cerebrospinal fluid (CSF) with vasospasm severity and rabbit neurologic status in subarachnoid hemorrhage was determined. The neurologic status of 20 New Zealand rabbits were graded initially and then, anesthetized and basal angiograms were performed. Then 1.0 mL of CSF was withdrawn through cisterna magna and then 1 mL autologous arterial blood was injected in all rabbits over 1 minute. After 5 days, neurologic severity score (NSS) and vertebrobasilar angiograms of all rabbits were repeated. Rabbits without radiologic vasospasm or spasm under 50% (n=7) were termed as group 1. Rabbits whose cerebral vasospasm were 50% or over 50% (n=7) and NSS is lesser than 3 were termed as groups 2, and rabbits whose cerebral vasospasm were 50% or above 50% (n=7) and NSS is greater than 3 were termed groups 3. On day 7, the CSF lactate values of each group were significantly different (P<0.05) with each other. But when compared with only CSF baseline lactate values groups 2 and 3 were significantly different (P<0.05). However, the NSSs were similar in groups 1 and 2, but group 3 significantly differed from groups 1 and 2 (P<0.05). All groups significantly differed from baseline NSSs (P<0.05). The data showed clearly that the degree of vasospasm correlates not only with neurologic status but also with CSF lactate levels. We suggest that CSF lactate level may be useful as a surrogate marker of cerebral vasospasm degree after subarachnoid hemorrhage in clinics where invasive cerebral angiography could not be assessed for whatever reasons.
American Journal of Emergency Medicine | 2015
Hasan Kara; Murat Akinci; Selim Degirmenci; Aysegul Bayir; Ahmet Ak
The presence of air in the spinal canal is known as pneumorrhachis (PNR), aerorachia, intraspinal pneumocele, pneumosaccus, pneumomyelogra, or intraspinal air. Pneumorrhachis may be iatrogenic, traumatic, and nontraumatic. We treated 2 patients who had posttraumatic PNR in the cervical spine region after stab injuries. Case 1 was a 31-year-old man who was stabbed in the C5 to C6 region. He had muscle weakness (3/5) and numbness on the right side of the body. Brain computed tomographic (CT) scan showed pneumocephalus, and cervical CT scan showed PNR at the C6 level. Treatment included observation, and symptoms and weakness improved within 7 days. Case 2 was a 40-year-old man who was stabbed in the C3 to C4 region. He had muscle weakness (1/5) and numbness on the left side of the body. Brain CT scan showed pneumocephalus, and cervical CT scan showed PNR at the C3 level. Cerebrospinal fluid drainage persisted, and he was treated with surgical repair of a dural laceration. Muscle strength improved. In summary, PNR is a rare condition that usually is treated nonoperatively. However, surgical treatment may be indicated for persistent neurologic symptoms or signs; the air detected in the spinal canal with radiographic imaging may be associated with an active cerebrospinal fluid leak and may cause spinal compression.
Human & Experimental Toxicology | 2013
Aysegul Bayir; Hasan Kara; Ö Köylü; R Kocabaş; Ahmet Ak
The aim of this study was to examine the effects of ubiquinone (CoQ10) on heart tissue and erythrocytes in acute organophosphate poisoning (AOP). A total of 20 rabbits were divided into three groups: sham (n = 8), pralidoxime (PAM) + atropine (n = 6), and CoQ10 + PAM + atropine (n = 6). Blood samples were taken from each test subject to measure the values of acetylcholinesterase (AChE), nitric oxide (NO), and malondialdehyde (MDA) in the plasma and erythrocyte before administration of 50 mg/kg dichlorvos by orogastric tube. Blood samples were then taken at 1, 12, and 24 h post-dichlorvos to determine plasma and erythrocyte levels of AChE, NO, and MDA. Sham group received no treatment. PAM + atropine group received 0.05 mg/kg atropine with repeated doses and PAM: first a 30-mg/kg intravenous (IV) bolus, then a 15-mg/kg IV bolus every 4 h. CoQ10 + PAM + atropine group received same dose PAM and atropine and a 50-mg bolus of IV CoQ10. Thoracotomy was performed in all the animals 24 h after poisoning and then heart tissue samples were obtained. At 12 and 24 h, erythrocyte AChE levels in the CoQ10 animals were considerably higher than those in PAM + atropine animals (p = 0.023 and 0.017, respectively). At 12 and 24 h, erythrocyte MDA and NO levels in CoQ10 animals were significantly lower than those in PAM + atropine animals (p < 0.05). Heart tissue AChE levels in CoQ10 animals were considerably higher than those of the sham and PAM + atropine animals (p = 0.001). Heart tissue MDA and NO levels of CoQ10 animals were significantly lower than those of the sham and PAM + atropine animals (p < 0.01). Treatment of AOP with CoQ10 + PAM + atropine in this animal model had a beneficial effect on both erythrocyte and heart tissue lipid peroxidation and AChE activity.