Time filter

Source Type

Izci Y.,Gulhane Military Medical Academy
Medical Hypotheses | Year: 2010

Cerebral ischemia, a phenomenon of reduction in cerebral blood flow, accounts for approximately 80% of all strokes, the third leading cause of death and the leading cause of adult disability. Cerebral ischemia causes heterogeneous changes in tissue oxygenation and cellular metabolism. Focal brain ischemia induces a profound and long-lasting inflammatory reaction which is dominated by macrophages derived from both resident microglia and circulating monocytic precursors.Bone marrow and spleen serve as a reservoir for hematopoietic progenitor cells, especially in rodents. Spleen-derived mononuclear cells home to the site of vascular injury and reduced neointima formation. The migration and engraftment of systematically administered spleen-derived mononuclear cells can be visualized in the post-ischemic brain. Therefore, we hypothesise that removal of the spleen may possibly decrease the production of mononuclear cells, and thus hinder or relieve the inflammatory reaction occured after cerebral ischemia/reperfusion injury. So, the splenectomy may be a prophylactic treatment method for cerebral ischemia. © 2010 Elsevier 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.

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.

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.

Discover hidden collaborations