Scopus İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://gcris.khas.edu.tr/handle/20.500.12469/1248

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Citation Count: 30
Effect of low-dose methyl prednisolone on serum cytokine levels following extracorporeal circulation
(Arnold Hodder Headline Plc., 1999) Yılmaz, Mert; Ener, Serdar; Akalın, Halis; Sağdıç, Kadir; Serdar, O. Akin; Cengiz, Mete
The systemic inflammatory response to cardiopulmonary bypass (CPB) is associated with increased production of cytokines. This systemic inflammatory response characterized by the activation of interleukin-6 (IL-6) and interleukin-8 (IL-8) during and after CPB is well documented. A prospective randomized double-blind study was performed so as to understand the effects of low-dose methyl prednisolone sodium succinate (MPSS) on the circulating levels of serum cytokines and clinical outcome. Twenty patients were randomly divided into two groups on the basis of the administration of low-dose(1 mg/kg) MPSS in = 10) and placebo in = 10) into the pump prime solution. All patients were scheduled to undergo a primary
Citation Count: 21
Going against the national cultural grain: a longitudinal case study of organizational culture change in Turkish higher education
(Carfax Publishing, 2000) Herguner, Gülten; Reeves, Nigel B.R.
This paper presents results of a longitudinal case study inquiry into the measurement of organizational culture change through the implementation of total quality management (TQM) concepts in a higher education context. The inquiry deals with the relationship between national culture and the company corporate culture the consequences of manager style change for TQM implementation and how culture change can be measured adequately. The results are achieved by the utilization of external (quantitative) and internal (qualitative) measurement devices. Limitations consequent upon the number of participants and the dual role of the researcher indicate the potential value of further investigations into the topic using these devices. The main conclusion is that the maintenance of TQM systems without continued senior managerial commitment may not suffice to secure change and prevent a reversion to earlier cultural patterns. Certainly since the findings of this inquiry are limited to one case study it would be unwise to assume that similar results would necessarily pertain in other higher education contexts. Nevertheless we are of the view that the findings are suggestive of the pressures imposed on organizational change by national cultural patterns. The devices implemented for measuring organizational cultural change while not designed for that purpose have however yielded sufficiently well-defined results to suggest the value of similar implementations to gain insight into the topic in further higher education and other organizational contexts.
Citation Count: 9
VLSI implementation of GRBF (Gaussian Radial Basis Function) networks
(IEEE, 2000) Çevikbaş, I. Can; Öğrenci, Arif Selçuk; Dündar, Günhan; Balkır, Sina
A GRBF network is designed for VLSI implementation. Building blocks of the network consist mainly of analog circuits: op-amp multiplier multiplying DAC (digital to analog converter) floating resistor summer and exponentiator. Parameters of the network (center width of the Gaussian function and output layer weights) are represented digitally for convenient interfacing. It is shown that individual GRBF units allow independent tuning of center width and amplitude. Several network structures are simulated as function approximation examples and the performance is verified to be satisfactory.
Citation Count: 23
The use of the 5-HT3-receptor antagonist ondansetron for the treatment of postcardiotomy delirium
(W.B. Saunders Co Ltd, 2000) Bayındır, Osman; Akpınar, Belhhan; Can, Erol; Güden, Mustafa; Sönmez, Bingür; Demiroğlu, Cemşid
Objective:To evaluate the effect of the 5-HT3-receptor antagonist ondansetron in patients with postcardiotomy delirium. Design: Prospective study. Setting: University hospital. Participants: Thirty-five patients who had undergone coronary artery bypass graft surgery. Interventions: Thirty-five patients 23 men and 12 women who developed delirium in the intensive care unit after coronary artery bypass graft surgery were included. Mean patient age was 51.3 years (range 36 to 79 years). A mental status scoring scale was developed and patients were scored 0 to 4 according to their delirium status after confirming that there were no correctable metabolic abnormalities as an underlying cause for delirium. Normal behavior was scored as 0 and severe verbal and physical agitation was scored as 4. Patients received a single dose of ondansetron 8 mg intravenously and were reevaluated 10 minutes later. Measurements and Main Results: Before the treatment 7 patients had a score of 2 (20)
Citation Count: 33
Primary epiploic appendagitis CT manifestations
(Elsevier Science Inc, 2000) Şırvancı, Mustafa; Tekelioğlu, Mehmet H.; Duran, Cihan; Yardımcı, Hakan; Onat, Levent; Özer, Kadir
Inflammation of an epiploic appendage is considered to be a rare cause of acute abdomen. Recently it has been reported that typical computed tomography (CT) findings of primary epiploic appendagitis (PEA) provide a definitive diagnosis in most of the cases. However since these papers are only few they are easily overlooked by the practicing radiologists. Our purpose is to add four new cases to the existing literature and to perform a review of the literature. (C) 2001 Elsevier Science Inc. All rights reserved.
Citation Count: 10
Acute gastrointestinal complications after open heart surgery
(Asia Publishing Exchange Pte Ltd, 2000) Akpınar, Belhhan; Sağbaş, Ertan; Güden, Mustafa; Kemertas, Kubilay; Sönmez, Bingür; Bayındır, Osman; Demiroğlu, Cemşid
Retrospective analysis revealed that 24 of 4401 adult patients (0.5%) developed severe gastrointestinal complications after open heart surgery during a 3-year period from January 1995. There were 4 women (17%) and 20 men (83%). Mean age was 61.7 ± 2.02 years. Gastrointestinal bleeding (33.3%) mesenteric ischemia (20.8%) pancreatitis (20.8%) hepatic dysfunction (16.7%) and cholecystitis (16.7%) were the most common complications. Mortality was 41.7% (10 patients). During the same period mortality in the patients who did not develop gastrointestinal complications was 1.89% (p < 0.0001). Emergency basis reoperation combined operations peripheral vascular disease diabetes mellitus chronic lung disease and impaired left ventricle function were found to be risk factors for the development of postoperative gastrointestinal complications.
Citation Count: 0
A synthesis tool for the multiplierless realization of FIR-based multirate DSP systems
(IEEE, 2000) Yurdakul, Arda
In this study a synthesis tool using a novel multirate folding technique which handles each FIR filter in a multirate DSP system as a single node is developed. A new architecture is presented for the multiplierless realization of a fold of multirate FIR filters. This synthesizer fully exploits the redundancies (i.e. `idle' and `missing' cycles) and common terms in multirate systems without sacrificing from overall system quality to produce multiplierless multirate systems. It also enables the usage of a single clock for all parts of the circuit.
Citation Count: 17
Off-pump coronary artery bypass grafting with use of the octopus 2 stabilization system
(2000) Akpınar, Belhhan; Güden, Mustafa; Sağbaş, Ertan; Sanisoğlu, İlhan; Aytekin, Vedat; Bayındır, Osman
Background: The treatment of coronary artery disease has evolved rapidly over the last two decades. The gold standard of surgical revascularization, the on-pump coronary artery bypass graft, has been challenged by the development of percutaneous transluminal coronary angioplasty. Our experience with the alternative of the off-pump ("beating heart") coronary artery bypass (OPCAB) technique during a period of 18 months suggests that OPCAB avoids the complications of cardiopulmonary bypass and offers patients the benefit of long-term graft patency that greatly exceeds that of current endovascular technologies. Methods: The early results of 126 OPCAB procedures performed through a medial sternotomy incision during a period of 18 months were evaluated. There were 80 male and 46 female patients, with a mean age of 69 +/- 4.3 years. Emergency cases and reoperations were not included. A total of 268 anastomoses were performed, with a mean number of 2.12 anastomoses per patient. Conduits used, with their percentage of use, were: left internal thoracic artery (LITA) (100%), right internal thoracic artery (11.1%), greater saphenous vein (84%), and radial artery (31%). In 72% of the cases, off-pump surgery was chosen because of patient risk factors such as atherosclerotic aortic disease, previous cerebrovascular accident or carotid artery disease, renal dysfunction, malignancy or poor left ventricular function. Results: There was no operative mortality. One-month postoperative mortality was three patients (2.3%). Two died because of mesenteric ischemia, and the other death was due to cardiac failure. Seventy-one patients had a control angiogram before discharge. The patency of LITA anastomosis was 100% while overall patency rate was 95%. In 43 patients for whom an angiogram could not be performed, a Thallum 201 stress test was performed three months postoperatively. Thirty-eight patients had a normal test while five patients showed signs of ischemia. These patients had a control angiogram: in four patients anastomoses were patent, but in one patient there was a severe narrowing of a venous anastomosis to the distal right coronary artery (RCA) which was corrected with angioplasty. In the whole series eight patients (6.3%) refused to have any control examination. Conclusions: Our early results suggest that off-pump CABG with Octopus 2 (Medtronic, Inc., Minneapolis, MN) can be a good alternative in high risk patients who need multiple vessel revascularization.
Citation Count: 18
Off-pump coronary artery bypass grafting with use of the octopus 2 stabilization system.
(2000) Akpinar,B.; Güden,M.; Sagbas,E.; Sanisoglu,I.; Aytekin,V.; Bayindir,O.
BACKGROUND: The treatment of coronary artery disease has evolved rapidly over the last two decades. The gold standard of surgical revascularization, the on-pump coronary artery bypass graft, has been challenged by the development of percutaneous transluminal coronary angioplasty. Our experience with the alternative of the off-pump ("beating heart") coronary artery bypass (OPCAB) technique during a period of 18 months suggests that OPCAB avoids the complications of cardiopulmonary bypass and offers patients the benefit of long-term graft patency that greatly exceeds that of current endovascular technologies. METHODS: The early results of 126 OPCAB procedures performed through a medial sternotomy incision during a period of 18 months were evaluated. There were 80 male and 46 female patients, with a mean age of 69 +/- 4.3 years. Emergency cases and reoperations were not included. A total of 268 anastomoses were performed, with a mean number of 2.12 anastomoses per patient. Conduits used, with their percentage of use, were: left internal thoracic artery (LITA) (100%), right internal thoracic artery (11.1%), greater saphenous vein (84%), and radial artery (31%). In 72% of the cases, off-pump surgery was chosen because of patient risk factors such as atherosclerotic aortic disease, previous cerebrovascular accident or carotid artery disease, renal dysfunction, malignancy or poor left ventricular function. RESULTS: There was no operative mortality. One-month postoperative mortality was three patients (2.3%). Two died because of mesenteric ischemia, and the other death was due to cardiac failure. Seventy-one patients had a control angiogram before discharge. The patency of LITA anastomosis was 100% while overall patency rate was 95%. In 43 patients for whom an angiogram could not be performed, a Thallum 201 stress test was performed three months postoperatively. Thirty-eight patients had a normal test while five patients showed signs of ischemia. These patients had a control angiogram: in four patients anastomoses were patent, but in one patient there was a severe narrowing of a venous anastomosis to the distal right coronary artery (RCA) which was corrected with angioplasty. In the whole series eight patients (6.3%) refused to have any control examination. CONCLUSIONS: Our early results suggest that off-pump CABG with Octopus 2 (Medtronic, Inc., Minneapolis, MN) can be a good alternative in high risk patients who need multiple vessel revascularization.
Citation Count: 1
Long-standing seroma after ultrasound-assisted liposuction
(Lippincott Williams & Wilkins, 2001) Ağaoğlu, Galip; Erol, O. Onur
[Abstract Not Available]
Citation Count: 8
Does off-pump coronary artery bypass surgery reduce mortality in high risk patients?
(Forum Multimedia Publishing LLC., 2001) Akpınar, Belhhan; Güden, Mustafa; Sanisoğlu, İlhan; Sağbaş, Ertan; Caynak, Barış; Bayramoğlu, Zehra; Bayındır, Osman
Background: The aim of this retrospective study was to compare outcome in two groups of patients who were classified according to their risk groups and underwent coronary revascularization with or without cardiopulmonary bypass. Material and Methods: Between January 1996 and July 2000 480 cases that underwent coronary artery bypass surgery (CABG) were included in a retrospective nonrandomized manner for study. Group I included 210 patients who were revascularized using off-pump techniques. Octopus 2 and 3 (Medtronic Inc. Minneapolis MN) were used for tissue stabilization. Group 2 included 270 cases who underwent CABG using CPB. Emergency cases combined operations reoperations and patients in cardiogenic shock were excluded. Demographic variables were comparable between two the groups. Using the Allegheny Clinic Risk Scoring Scale [Magovern 1996] patients in both groups were scored as low moderate and high risk. In Group 1 37% of patients consisted of high risk patients while Group 2 had 14% (p < 0.05) Student's t-test and chi-square test were used for statistical analysis and alfa < 0.05 was considered significant. Results: Mortality was 1.4% in Group 1 and 1.5% in Group 2 (p = ns). Mean anastomosis per patient was 2.6 +/- 0.6 in Group 1 and 3.2 +/- 0.5 in Group 2 (p < 0.05). Patients in Group I needed less blood transfusions and less inotropic support postoperatively (p < 0.05). There were also fewer minor neurological events (p < 0.05) and pulmonary complications (Type 2) in Group 1. Atrial fibrillation rate infection and major neurological deficit (Type 1) were similar in both groups. Mortality was less among Group 1 high risk patients (3.9%) in comparison to Group 2 high risk patients (7.9%) but this did not reach statistical significance. Conclusions: In low or moderate risk patients CABG can be performed safely with or without CPB. In high risk patients with several comorbidities off-pump CABG seems to be a safe and efficient method that can improve outcome.
Citation Count: 62
Interactions of polyacrylamide polymer with bentonite in aqueous systems
(Elsevier Science Bv, 2001) Güngör, Nurfer; Karaoğlan, S
The flow properties of natural Ca bentonite and Na bentonite-water systems were studied after adding an anionic polyacrylamide (PAM) polymer. The effect of the PAM has also been investigated at different quantities. The experimental results are discussed in terms of bentonite forms and concentration of PAM. Besides measurement of theological properties of Ca bentonite + PAM and Na bentonite + PAM systems have been examined in detail through XRD FT-IR and DTA analyses. (C) 2001 Elsevier Science B.V. All rights reserved.
Citation Count: 11
Electrical activity regulates AChR gene expression via JNK PKC zeta and Sp1 in skeletal chick muscle
(Elsevier Science Bv, 2001) Altiok, Nedret; Changeux, Jean-Pierre
Electrical activity of myotubes represses nicotinic acetylcholine receptor (AChR) gene expression. This effect is mimicked by okadaic acid and blocked by tetrodotoxin (TTX) or staurosporine in cultured myocytes [Altiok et al. EMBO J. 16 (1997) 717-725]. In this study we investigated the mechanism of this repression. We show that addition of exogenous phospholipase D (PLD) and C inhibits AChR expression in a manner which parallels that of okadaic acid. Furthermore okadaic acid caused an increase of the threonine phosphorylation of protein kinase C zeta (PKC zeta) and activator of transcription factor (ATF2) and a decrease of the phosphorylation of Sp1. All these effects were reversed by staurosporine and TTX also abolished ATF2 phosphorylation. These data reveal a possible involvement of PLD c-jun N-terminal kinase PKC zeta and Sp1 in the repression of AChR genes by electrical activity. (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.
Citation Count: 20
Ondansetron hydrochloride for the treatment of delirium after coronary artery surgery
(Mosby Inc, 2001) Bayındır, Osman; Güden, Mustafa; Akpınar, Belhhan; Sanisoğlu, İlhan; Sağbaş, Ertan
[Abstract Not Available]
Citation Count: 3
Hip fracture-dislocation (Pipkin type IV) associated with an apparent traumatic aortic valve rupture. Case history
(2001) Gögüş, A.; Akpinar, S.; Unal, M.; Sönmez, B.; Hamzaoglu, A.
Traumatic aortic valve rupture with resultant aortic insufficiency is a rare complication of blunt trauma. Here reported is a case with a posterior fracture-dislocation of the hip (Pipkin type-IV) and an undisplaced sternum fracture who developed hemodynamic instability in the clinical follow-up and was diagnosed having a traumatic aortic valve rupture using echocardiography. He first was treated with a biological valve replacement. Two weeks later a total hip arthroplasty combined with the osteosynthesis of the posterior wall of the acetabulum was performed. Sternum fracture healed conservatively. In multiply injured patients especially with a blunt thorax trauma hemodynamic instability despite appropriate fluid replacement should rise the suspicion of cardiac injuries, especially traumatic aortic valve rupture. Echocardiography is a simple but reliable method for the diagnosis.
Citation Count: 1
Screening of a stentless valve with electron beamed tomograpy 5 years after operation
(2001) Akpınar, Belhhan; Güden, Mustafa; Memişoğlu, Esat I.
[Abstract Not Available]
Citation Count: 8
Removal of UroLume endoprosthesis using holmium : YAG laser
(Mary Ann Liebert Inc Publ, 2001) Kural, Ali Riza; Tüfek, İlter; Akpınar, Haluk; Gürtuğ, Adil
A potential complication of UroLume endoprosthesis is migration which may necessitate removal of the stent. Stent removal may be associated with complications such as urethral injury bleeding and external sphincter trauma. We report a patient in whom a holmium:yttrium-aluminium-garnet (Ho:YAG) laser was used to cut the UroLume endoprosthesis into fragments which led to easy and uneventful stent removal.
Citation Count: 2
The evaluation of microbial contamination in platelet concentrates prepared by two different methods
(Pergamon-Elsevier Science Ltd, 2001) Kocazeybek, Bekir Sami; Arabaci, Ümit; Akdur, Hülya; Sezgic, Metin; Erentürk, Selim
The microbial contamination of platelet concentrates (PCs) prepared by two different methods both with a high risk of bacterial contamination during preparation and storage were evaluated. For apheresis platelets the concentrates were obtained using the Haemonetics MCS 3P device. For the random method platelets were obtained by two phase centrifugation in the Heraeus Cryofuge 8500 I device using the Kansuk 3-way bags which permit storage for five days. 1620 platelet pheresis units prepared by apheresis and 9838 units prepared by the random method were included in the study. Of the 11458 PCs studied 32 (0.27%) were false positives and 24 (0.2%) were real positives. All of the positive results occurred in platelets prepared by the random method. C. xerosis and S. epidermidis S. hominis Alpha-hemolytic streptococci all flora of the skin were isolated in the contaminated concentrates. The risk of microbial contamination of PCs prepared both by apheresis and from whole blood continues at a low rate although the products were collected into specific bags following rules including appropriate disinfection of the skin correct centrifugation collection time and optimal storage conditions including temperature and agitation. These results again emphasize the importance of. obeying phlebotomy rules and hand disinfection of the person who collects the blood as well as the need for careful skin decontamination of the donor during donation. (C) 2001 Elsevier Science Ltd. All rights reserved.
Citation Count: 12
Acute aortic valve regurgitation secondary to blunt chest trauma
(Texas Heart Inst., 2001) Ünal, Mehmet; Demirsoy, Ergun; Göğüş, Abdullah; Arbatlı, Harun; Hamzaoğlu, Azmi; Sönmez, Bingür
Blunt injury to the cardiac valves leads to progressive acute ventricular failure which often requires urgent surgical management In this case report we describe an acute aortic valve rupture caused by air-bag inflation during an automobile accident. Laceration of an aortic valve cusp was treated successfully with urgent aortic valve replacement. A concomitant orthopedic injury was treated electively 15 days after cardiac surgery. Acute aortic valve rupture is a very rare complication of blunt chest trauma. We discuss how to diagnose and manage this potentially catastrophic event.
Citation Count: 4
The use of composite stentless valves with graft extension for the treatment of ascending aortic aneurysms
(Elsevier Science Bv, 2001) Akpınar, Belhhan; Güden, Mustafa
[Abstract Not Available]

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