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Öğe Effect of rivastigmine on regional cerebral blood flow in Alzheimer's disease(Springer, 2007) Cerci, Sevim Sureyya; Tamam, Yusuf; Kaya, Halil; Yildiz, Mustafa; Arslan, SeyfiCholinesterase inhibitors improve or stabilize cognitive impairment in patients with Alzheimer's disease (AD). The purpose of this study was to detect brain perfusion changes and the effects of rivastigmine, an acetylcholinesterase inhibitor on single photon emission computed tomography (SPECT) before and after treatment. Fifteen patients who fulfilled the clinical criteria for probable AD of mild to moderate severity, as put forth by the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association, and as specified by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, were included in the study. A control group of 15 healthy individuals from the same age and education range was included in the study. Before treatment was begun, Mini Mental State Examination (MMSE) tests were performed on all patients to evaluate cognitive function. All patients underwent baseline SPECT for evaluation of 25 different brain regions. Rivastigmine 3 mg/d was given for the first 4 wk of treatment; the dosage was then increased to 6 mg/d. The MMSE and SPECT were repeated 6 mo after the start of treatment. SPECT findings revealed that rivastigmine did not significantly affect brain perfusion in AD cases except in the inferior frontal lobe, despite stabilization and improvement noted in MMSE scores during treatment. Rivastigmine treatment of patients with AD did not significantly change brain perfusion as seen on SPECT, except in the inferior frontal lobe, but cognitive performance was stabilized or improved during the treatment course. These findings suggest the need for additional, larger studies to investigate the effects of acetylcholinesterase inhibitors on regional cerebral blood flow.Öğe The effects of needle deformation during lumbar puncture(Wolters Kluwer Medknow Publications, 2015) Ozdemir, Hasan Huseyin; Demir, Caner F.; Varol, Sefer; Arslan, Demet; Yildiz, Mustafa; Akil, EsrefObjective: The aim of this study is to assess deformation of the tip and deflection from the axis of 22-gauge Quincke needles when they are used for diagnostic lumbar puncture (LP). Thus, it can be determined whether constructional alterations of needles are important for predicting clinical problems after diagnostic LP. Materials and Methods: The 22-gauge Quincke needles used for diagnostic LP were evaluated. A specially designed protractor was used for measurement and evaluation. Waist circumference was measured in each patient. Patients were questioned about headaches occurring after LP. Results: A total of 115 Quincke-type spinal needles used in 113 patients were evaluated. No deflection was detected in 38 (33.1%) of the needles. Deflection between 0.1 degrees and 5 degrees occurred in 43 (37.3%) of the needles and deflection >= 5.1 degrees occurred in 34 patients (29.6%). Forty-seven (41.5%) patients experienced post lumbar puncture headache (PLPH) and 13 (11.5%) patients experienced intracranial hypotension (IH). No statistically significant correlation between the degree of deflection and headache was found (P > 0.05). Epidural blood patch was performed for three patients. Deformity in the form of bending like a hook occurred in seven needles and IH occurred in six patients using these needles. Two of the needles used in three patients requiring blood patch were found to be bent. Conclusion: Deformation of needles may increase complications after LP. Needle deformation may lead to IH. In case of deterioration in the structure of the needle, termination of the puncture procedure and the use of a new needle could reduce undesirable clinical consequences, especially IH.Öğe An organic-inorganic rectifying contact based on a ZnPc derivative(Elsevier Sci Ltd, 2014) Ozerden, Enise; Yildiz, Mustafa; Ocak, Yusuf Selim; Tombak, Ahmet; Kilicoglu, TahsinAn organic-inorganic rectifying contact was fabricated by forming a thin film of a Zinc Phthalocyanine (ZnPc) derivative, Zinc 2,3,9,10,16,17,23,24-octakis(octyloxy)-29H, 31H-phthalocyanine (oc-ZnPc), on a p-Si wafer and evaporating Al on the structure. The current-voltage (I-V) and capacitance-voltage (C-V) measurements of Al/oc-ZnPc/p-Si structure were taken in dark at room temperature. The I-V measurements proved that the structure showed excellent rectification. Some basic diode parameters like ideality factor and barrier height were calculated from lnI-V plot. Ideality factor and barrier height values were found as 144 and 0.78 eV, respectively. The series resistance value of the structure was determined as 5.46 k Omega by means of Norde functions. The C-V measurements were taken for various frequencies and it was seen that the capacitance value decreased with increasing frequency. In addition I-V measurements of the Al/oc-ZaPc/p-Si/Al were repeated under light which had illumination intensity of 40-100 mW/cm(2). It was observed that reverse bias current of the diode increased with the light intensity. Therefore, the structure showed photodiode characteristics and it can be used for electrical and optoelectronic applications. (C) 2014 Elsevier Ltd. All rights reserved.Öğe The role of High Mobility Group Box 1 (HMGB1) in colorectal cancer(Int Scientific Literature, Inc, 2014) Suren, Dinc; Yildirim, Mustafa; Demirpence, Ozlem; Kaya, Vildan; Alikanoglu, Arsenal Sezgin; Bulbuller, Nurullah; Yildiz, MustafaBackground: HMGB1, the most important member of the high mobility group box protein family, is a nuclear protein with different functions in the cell; it has a role in cancer progression, angiogenesis, invasion, and metastasis development. We studied the expression of HMGB1 and whether it is a prognostic factor in colorectal carcinoma. Material/Methods: The study included 110 cases that were histopathologically diagnosed with colorectal carcinoma from the tissue samples acquired by surgical resection and biopsy in Antalya Education and Research Hospital between 2008 and 2012. HMGB1 expression was examined via immunohistochemical method. Results: HMGB1 expression was evaluated as negative in 32 (44.4%) of the patients and as positive in 40 (55.6%) patients. There was no relation between the HMGB1 expression and sex, age, tumor invasion depth, and histological type. However, a significant relation was detected between the HMGB1 expression and lymph node status, metastasis status, and stage (p:<0.001, p:<0.001, p:<0.001, respectively). Similar results were obtained for the relations between the HMGB1 and histological grade, perineural invasion, lymphovascular invasion, and lymphocytic response (p<0.001, p<0.001, p<0.001, and p<0.001, respectively). Conclusions: The results of our study demonstrate that HMGB1 overexpression has a significant role in tumor progression (especially migration of tumor cells) and tumor ability to metastasize in colorectal cancers; thus, it corroborates the idea that it might be an important prognostic factor.
