Gulhane Military Medical Academy

Üsküdar, Turkey

Gulhane Military Medical Academy

Üsküdar, Turkey
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Simsek H.,Gulhane Military Medical Academy
British Journal of Neurosurgery | Year: 2017

Chronic sinusitis can be complicated with erosion of anterior or posterior wall of the sinus; causing Pott’s puffy tumour in the anterior, or epidural abscess in the posterior communication. A 65-year old man with a painful swelling in his forehead is presented. Pott’s puffy tumour was diagnosed. CT, MRI, and DTI studies were obtained. Epidural or dural involvement was not present. In the first operation, anterior wall of the frontal sinus wall was opened. Osteomyelitis debridement was performed and the frontonasal duct was enlarged endoscopically. Antibiotics were commenced and were continued for 6 weeks. In the second operation, nasal septum deviation was fixed. Postoperative course was uneventful. The presented case suggests that treatment of sinus osteomyelitis should comprise immediate surgical drainage and osteomyelitis debridement followed by long-term administration of antibiotics. MRI study with contrast should be obtained to rule out epidural abscess and dural infiltration. © 2017 The Neurosurgical Foundation

Uzbay T.I.,Gulhane Military Medical Academy
Neuroscience and Biobehavioral Reviews | Year: 2012

Agmatine is a polyamine that is produced via decarboxylation of l-arginine by the enzyme arginine decarboxylase. It binds to various receptors and has been accepted as a novel neurotransmitter in brain. In experimental studies, agmatine exhibited anticonvulsant, antinociceptive, anxiolytic and antidepressant-like actions. Furthermore, it has some beneficial effects on cerebral ischemia models in animals. Agmatine interacts with the mechanisms of withdrawal syndromes for several addictive agents. It also modulates some processes involved in learning and memory. Thus, agmatine seems to be a valuable agent for the treatment of behavioral and neurodegenerative disorders. However, the aberrant release and transmission of agmatine in the central nervous system (CNS) may be associated with mechanisms of several CNS disorders, such as psychosis. Interactions between agmatine and other central neurotransmitter systems, such as the glutamatergic and nitrergic systems, are also very important. In light of the current literature on agmatine, we can anticipate that the central agmatinergic system may be an important target in development of novel strategies and approaches for understanding the etiopathogenesis of some important central disorders and their pharmacological treatments. The main objective of this review is to investigate and update the information on effects of agmatine in CNS and highlight its pharmacological importance in central disorders. © 2011 Elsevier Ltd.

Kayir H.,University of California at San Diego | Kayir H.,Gulhane Military Medical Academy | Semenova S.,University of California at San Diego | Markou A.,University of California at San Diego
Progress in Neuro-Psychopharmacology and Biological Psychiatry | Year: 2014

Impulsive choice, a form of impulsivity, is associated with tobacco smoking in humans. Trait impulsivity may be a vulnerability factor for smoking, or smoking may lead to impulsive behaviors. We investigated the effects of 14-day nicotine exposure (6.32. mg/kg/day base, subcutaneous minipumps) and spontaneous nicotine withdrawal on impulsive choice in low impulsive (LI) and high impulsive (HI) rats. Impulsive choice was measured in the delayed reward task in which rats choose between a small immediate reward and a large delayed reward. HI and LI rats were selected from the highest and lowest quartiles of the group before exposure to nicotine. In non-selected rats, nicotine or nicotine withdrawal had no effect on impulsive choice. In LI rats, chronic nicotine exposure decreased preference for the large reward with larger effects at longer delays, indicating increased impulsive choice. Impulsive choices for the smaller immediate rewards continued to increase during nicotine withdrawal in LI rats. In HI rats, nicotine exposure and nicotine withdrawal had no effect on impulsive choice, although there was a tendency for decreased preference for the large reward at short delays. These results indicate that nicotine- and nicotine withdrawal-induced increases in impulsive choice depend on trait impulsivity with more pronounced increases in impulsive choice in LI compared to HI subjects. Increased impulsivity during nicotine exposure may strengthen the addictive properties of nicotine and contribute to compulsive nicotine use. © 2013 Elsevier Inc.

Balaban B.,Gulhane Military Medical Academy | Tok F.,Iskenderun Military Hospital
PM and R | Year: 2014

Poststroke hemiplegic gait is a mixture of deviations and compensatory motion dictated by residual functions, and thus each patient must be examined and his/her unique gait pattern identified and documented. Quantitative 3-dimensional gait analysis is the best way to understand the complex multifactorial gait dysfunction in hemiparetic patients. The goals of the present work are to (1) review the temporospatial, kinematic, kinetic, and electromyographic deviations from normal gait that commonly occur after stroke and are of clinical significance, along with the most likely causes of these deviations, and (2) differentiate the departures from normal gait parameters that arise as a direct consequence of poststroke motor problems and those that arise as learned or adaptive compensations for poststroke motor problems. © 2014 American Academy of Physical Medicine and Rehabilitation.

Kuru K.,Gulhane Military Medical Academy
Theoretical Biology and Medical Modelling | Year: 2014

Background: Hematoxylin & Eosin (H&E) is a widely employed technique in pathology and histology to distinguish nuclei and cytoplasm in tissues by staining them in different colors. This procedure helps to ease the diagnosis by enhancing contrast through digital microscopes. However, microscopic digital images obtained from this technique usually suffer from uneven lighting, i.e. poor Koehler illumination. Several off-the-shelf methods particularly established to correct this problem along with some popular general commercial tools have been examined to find out a robust solution. Methods. First, the characteristics of uneven lighting in pathological images obtained from the H&E technique are revealed, and then how the quality of these images can be improved by employing bilinear interpolation based approach applied on the channels of Lab color mode is explored without losing any essential detail, especially for the color information of nuclei (hematoxylin stained sections). Second, an approach to enhance the nuclei details that are a fundamental part of diagnosis and crucially needed by the pathologists who work with digital images is demonstrated. Results: Merits of the proposed methodology are substantiated on sample microscopic images. The results show that the proposed methodology not only remedies the deficiencies of H&E microscopical images, but also enhances delicate details. Conclusions: Non-uniform illumination problems in H&E microscopical images can be corrected without compromising crucial details that are essential for revealing the features of tissue samples. © 2014 Kuru; licensee BioMed Central Ltd.

Uzbay T.,Gulhane Military Medical Academy
Current Medicinal Chemistry | Year: 2012

A polyamine agmatine is produced through decarboxylation of L -arginine by the enzyme arginine decarboxylase and is a new neurotransmitter in central nervous system (CNS). It has been suggested that agmatine has analgesic, anxiolytic and antidepressant activities in animals. In experimental studies, it also generates some favorable effects on cerebral damages and withdrawal syndromes involved in addictive drugs. Furthermore, it modulates some processes of learning and memory. Thus, agmatine may be an important target for the treatment of CNS disorders. However, the abnormal release and transmission of agmatine in brain may also be related to some CNS disorders, such as schizophrenia. Interaction of agmatine with other central neurotransmitter systems, such as the glutamatergic and nitrergic systems, seems to be very important. According to the current literature, we can expect that the central agmatinergic system may be a new key target in development of novel approaches for understanding the etiopathogenesis of CNS disorders and their treatment with drugs. The main goal of this article is to evaluate the effects of agmatine in CNS and underline its pharmacological actions in CNS and drug development. © 2012 Bentham Science Publishers.

Uzbay T.I.,Gulhane Military Medical Academy
Alcohol and Alcoholism | Year: 2012

Aims: Alcoholism and psychosis are known to have common neurochemical substrates. The aim of this review is to assess the reports involved in the effects of some atypical antipsychotic agents on the signs of ethanol withdrawal syndrome (EWS) in rats. Thus, both effectiveness of these drugs in ethanol withdrawal and the association between the drug effects and the signs have been investigated here on the same animal model. Methods: Adult Wistar rats were used as subjects. Ethanol was given to rats by modified liquid diet technique for inducing ethanol dependence. Clozapine, olanzapine, risperidone, quetiapine and ziprasidone were the drugs tested. Effects of these drugs on the signs of ethanol withdrawal such as locomotor hyperactivity, stereotyped behavior, tremor, wet dog shakes, tail-stiffness, abnormal posture and gait, agitation and audiogenic seizures were evaluated for the first 6 h of ethanol withdrawal. Results: Although some beneficial effects of all the drugs on ethanol withdrawal signs were observed, olanzapine precipitated abnormal posture and gait in the animals. Effectiveness rank of the used atypical antipsychotics was as follows: risperidone = quetiapine > ziprasidone > klozapine > olanzapine. Conclusion: Our results suggest that risperidone and quetiapine seem to be potent and pharmacologically more active agents on EWS in rats. Thus, these drugs may be beneficial in treatment of EWS in patients with alcoholism. Ziprasidone and clozapine also seem to be useful drugs in treatment of ethanol withdrawal. © The Author 2011. Published by Oxford University Press on behalf of the Medical Council on Alcohol. All rights reserved.

Kose O.,Gulhane Military Medical Academy
Pathology Research International | Year: 2012

Behçet disease is a chronic relapsing vasculitis with unclear etiology and immunopathogenesis. Antigenic stimuli, antigen presenting cells, T cells, monocyte, and neutrophil and endothelial cells are major parts of the pathology of the disease. Understanding of the new pathogenic mechanisms based on molecular structure of the disease helps us in improving the novel therapeutic modalities. These drugs target specific and nonspecific inhibition of the immun system. These therapies include biologic agents, new topical and systemic immunosuppressants, tolerizing agents, and immunoablation. Novel treatment will be promising to treat the especially recalcitrant cases to conventional therapy. In this paper, new aspect of the immunopathogenesis of Behçet's diseases and novel treatment modalities will be discussed. © 2012 Osman Köse.

Aktas Z.,Istanbul University | Kayacan C.,Istanbul University | Oncul O.,Gulhane Military Medical Academy
International Journal of Antimicrobial Agents | Year: 2012

The objective of this study was to investigate the in vitro antibacterial activity of avibactam (formerly NXL104) in combination with imipenem, cefepime or ceftazidime against Gram-negative bacteria. Bacterial isolates included: Pseudomonas aeruginosa harbouring PER-1 β-lactamase (n = 14); Acinetobacter baumannii harbouring PER-1, OXA-51 and OXA-58 (n = 20); carbapenem-non- susceptible Klebsiella pneumoniae (n = 25) and Escherichia coli (n = 1) harbouring OXA-48; carbapenem-non-susceptible E. coli (n = 1) harbouring both IMP-1 metallo-β-lactamase and extended-spectrum β-lactamase (ESBL); carbapenem-non-susceptible Serratia marcescens (n = 1); and carbapenem- susceptible E. coli (n = 20) and K. pneumoniae isolates (n = 12) with CTX-M-15 ESBL. Minimum inhibitory concentrations (MICs) of imipenem, cefepime and ceftazidime were determined in combination with 4 mg/L avibactam by the Clinical and Laboratory Standards Institute (CLSI) method on Mueller-Hinton agar. Imipenem/avibactam and ceftazidime/avibactam displayed limited potency against A. baumannii isolates, whereas cefepime/avibactam and ceftazidime/avibactam were active against P. aeruginosa. Klebsiella pneumoniae isolates with OXA-48 β-lactamase were resistant to imipenem [MIC for 90% of the organisms (MIC 90) ≥4 mg/L]. MIC 90 values for the combination of avibactam 4 mg/L with imipenem, cefepime and ceftazidime were in the susceptible range for all strains (MIC 90 ≤ 0.5 mg/L). All E. coli and K. pneumoniae isolates with CTX-M-15 β-lactamase were inhibited at ≤1 mg/L for combinations with avibactam and 100% were susceptible by CLSI breakpoint criteria to imipenem, cefepime and ceftazidime. In conclusion, combinations of imipenem, cefepime and ceftazidime with avibactam may present a promising therapeutic strategy to treat infections due to K. pneumoniae with OXA-48 enzyme as well as K. pneumoniae and E. coli with CTX-M-15 enzyme. © 2011 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Purpose: To determine the agreement between dynamic contour tonometer (DCT), Goldmann applanation tonometer (GAT), and Ocular Response Analyzer (ORA) in keratoconic corneas and to find out the effect of corneal biomechanics on intraocular pressure (IOP) measurements obtained by these devices. SUBJECTS AND Methods: IOP was measured with the ORA, DCT, and GAT in random order in 120 eyes of 61 keratoconus patients. Central corneal thickness (CCT) and keratometry were measured after all IOP determinations had been made. The mean IOP measurement by the ORA and DCT was compared with the measurement by the GAT, using Student t test. Bland-Altman analysis was performed to assess the clinical agreement between these methods. The effect of corneal hysteresis (CH), corneal resistance factor (CRF), and CCT on measured IOP was explored by multiple backward stepwise linear regression analysis. Results: The mean±SD patient age was 30.6±11.2 years. The mean±SD IOP measurement obtained with GAT, ORA Goldmann-correlated IOP (IOPg), ORA corneal-compensated IOP (IOPcc), and DCT was 10.96±2.8, 10.23±3.5, 14.65±2.8, and 15.42±2.7 mm Hg, respectively. The mean±SD CCT was 464.08±58.4 microns. The mean difference between IOPcc and GAT (P<0.0001), IOPcc and DCT (P<0.001), GAT and DCT (P<0.0001), IOPg and GAT (P<0.002), and IOPg and DCT (P<0.0001), was highly statistically significant. In multivariable regression analysis, DCT IOP and GAT IOP measurements were significantly associated with CH and CRF (P<0.0001 for both). Conclusions: DCT seemed to be affected by CH and CRF, and the IOP values tended to be higher when compared with GAT. ORA-measured IOPcc was found to be independent of CCT and suitable in comparison to the DCT in keratoconic eyes. Copyright © 2010 by Lippincott Williams & Wilkins.

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