PubMed İndeksli Yayınlar Koleksiyonu

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Citation - WoS: 12
Citation - Scopus: 15
Accurate Refinement of Docked Protein Complexes Using Evolutionary Information and Deep Learning
(Imperıal College Press, 2016) Akbal-Delibas, Bahar; Farhoodi, Roshanak; Pomplun, Marc; Haspel, Nurit
One of the major challenges for protein docking methods is to accurately discriminate native-like structures from false positives. Docking methods are often inaccurate and the results have to be refined and re-ranked to obtain native-like complexes and remove outliers. In a previous work we introduced AccuRefiner a machine learning based tool for refining protein-protein complexes. Given a docked complex the refinement tool produces a small set of refined versions of the input complex with lower root-mean-square-deviation (RMSD) of atomic positions with respect to the native structure. The method employs a unique ranking tool that accurately predicts the RMSD of docked complexes with respect to the native structure. In this work we use a deep learning network with a similar set of features and five layers. We show that a properly trained deep learning network can accurately predict the RMSD of a docked complex with 1.40 angstrom error margin on average by approximating the complex relationship between a wide set of scoring function terms and the RMSD of a docked structure. The network was trained on 35000 unbound docking complexes generated by RosettaDock. We tested our method on 25 different putative docked complexes produced also by RosettaDock for five proteins that were not included in the training data. The results demonstrate that the high accuracy of the ranking tool enables AccuRefiner to consistently choose the refinement candidates with lower RMSD values compared to the coarsely docked input structures.
Citation - WoS: 9
Citation - Scopus: 12
Affective Modulation of Working Memory Maintenance: the Role of Positive and Negative Emotions
(UNIV ECONOMICS) Gökçe, Ahu; Zinchenko, Artyom; Annac, Efsun; Conci, Markus; Geyer, Thomas
The present study investigated the impact of task-irrelevant emotional images on the retention of information in spatial working memory (WM). Two experiments employed a delayed matching-to-sample task where participants had to maintain the locations of four briefly presented squares. After a short retention interval, a probe item appeared and participants were required to indicate whether the probe position matched one of the previously occupied square positions. During the retention interval, task-irrelevant negative, positive, or neutral emotional pictures were presented. The results revealed a dissociation between negative and positive affect on the participants' ability to hold spatial locations in WM. While negative affective pictures reduced WM capacity, positive pictures increased WM capacity relative to the neutral images. Moreover, the specific valence and arousal of a given emotional picture was also related to WM performance: While higher valence enhanced WM capacity, higher levels of arousal in turn reduced WM capacity. Together, our findings suggest that emotions up- or down-regulate attention to items in WM and thus modulate the short-term storage of visual information in memory.
Citation - Scopus: 10
Comparison of Intraoperative Transit-Time Flow Measurement With Early Postoperative Magnetic Resonance Flow Mapping: in Off-Pump Coronary Artery Surgery
(2003) Sanisoglu,I.; Guden,M.; Balci,C.; Sagbas,E.; Duran,C.; Akpinar,B.
The purpose of this prospective study was to evaluate graft patency of off-pump coronary artery surgery intraoperatively by transit-time flow measurement and to compare this technique with postoperative magnetic resonance flow mapping. Twenty patients (13 men and 7 women; mean age, 67.9 ± 7.6 yr) underwent off-pump coronary artery surgery. Intraoperative transit-time flow measurement of grafts was performed measuring maximum, minimum, and mean flows. For each graft, the pulsatile index was calculated by dividing the difference between the maximum and the minimum flow by the mean flow. In the early postoperative period (1st week), magnetic resonance flow mapping was performed using phase contrast flow quantification. Mean intraoperative flow values and mean magnetic resonance flow mapping values were compared. At the same postoperative session, contrast-enhanced magnetic resonance angiography was performed to evaluate graft patency. In 20 patients, a total of 49 coronary graft flows were assessed with intraoperative transit-time flow measurement and postoperative magnetic resonance flow mapping. Upon comparison, there was a strong correlation between techniques, with stable and statistically significant differences between the intraoperative and postoperative flow mapping values. One saphenous vein graft was revised intraoperatively, due to graft failure. Our data suggest that the combined use of intraoperative transit-time flow measurement and postoperative magnetic resonance flow analysis has a potential role in the assessment of graft patency in off-pump coronary artery surgery, although more study is required.
Citation - WoS: 40
Citation - Scopus: 45
Comparison of Three Different Combination Therapies in the Treatment of Human Brucellosis
(ROYAL SOC MEDICINE PRESS LTD, 2005) Ersoy, Yasemin; Sönmez, Emine; Tevfik, Mehmet R.; But, Ayşe Dinç
The efficacy and tolerability of three different combination treatment regimens in human brucellosis were compared in 118 uncomplicated patients enrolled in a prospective study between May 1997 and December 2002. Brucellosis was diagnosed using standard clinical and microbiological findings. Patients with central nervous system involvement spondylitis endocarditis or children under 16 years of age were excluded from the study. Patients were randomly assigned to receive 400 mg of ofloxacin plus 600 mg of rifampicin (OR n = 41)200 mg of doxycycline plus 600 mg of rifampicin (DR n = 45) or 1 g intramuscularly streptomycin (administered for three weeks) plus 200 mg doxycycline (DS n = 32) daily for 6 weeks. All patients were followed up at least 6 months after cessation of therapy. There was no statistical difference between the groups on relapse rates and clinical response to the treatment (P> 0.05). Five patients in OR (12.8%) six patients in DR (14.3%) and three patients in DS groups (9.7%) suffered relapse. The side-effects were seen in eight (19.5%) 21 (46.7%) and eight (25.0%) patients of OR DR and DS groups respectively. The use of combination therapy of ofloxacin plus rifampicin for 6 weeks was found to be as effective as DR and DS. The side-effects of therapy in OR and DS groups was less severe than in the DR group.
Citation - Scopus: 4
Computational Chemistry and Molecular Modeling of Reversible Mao Inhibitors
(Humana Press Inc., 2023) Yelekçi, K.; Erdem, S.S.
Proper elucidation of drug-target interaction is one of the most significant steps at the early stages of the drug development research. Computer-aided drug design tools have substantial contribution to this stage. In this chapter, we specifically concentrate on the computational methods widely used to develop reversible inhibitors for monoamine oxidase (MAO) isozymes. In this context, current computational techniques in identifying the best drug candidates showing high potency are discussed. The protocols of structure-based drug design methodologies, namely, molecular docking, in silico screening, and molecular dynamics simulations, are presented. Employing case studies of safinamide binding to MAO B, we demonstrate how to use AutoDock 4.2.6 and NAMD software packages. © 2023, The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.
Citation - WoS: 6
Citation - Scopus: 7
Cryogenic X-Ray Crystallographic Studies of Biomacromolecules at Turkish Light Source Turkish Delight
(Tubitak Scientific & Technological Research Council Turkey, 2023) Atalay, Necati; Akcan, Enver Kamil; Gul, Mehmet; Ayan, Esra; Destan, Ebru; Ertem, Fatma Betuel; Tokay, Nurettin
X-ray crystallography is a robust and powerful structural biology technique that provides high-resolution atomic structures of biomacromolecules. Scientists use this technique to unravel mechanistic and structural details of biological macromolecules (e.g., proteins, nucleic acids, protein complexes, protein-nucleic acid complexes, or large biological compartments). Since its inception, single-crystal cryocrystallography has never been performed in Turkiye due to the lack of a single-crystal X-ray diffractometer. The X-ray diffraction facility recently established at the University of Health Sciences, Istanbul, Turkiye will enable Turkish and international researchers to easily perform high-resolution structural analysis of biomacromolecules from single crystals. Here, we describe the technical and practical outlook of a state-of-the-art home-source X-ray, using lysozyme as a model protein. The methods and practice described in this article can be applied to any biological sample for structural studies. Therefore, this article will be a valuable practical guide from sample preparation to data analysis.
Decision Making, Emotion Recognition and Childhood Traumatic Experiences in Murder Convicts Imprisoned With Aggravated Life Sentence: a Prison Study
(Turkish Neuropsychiatry Assoc-Turk Noropsikiyatri Derneği, 2025) Cikrikcili, Ugur; Yildirim, Elif; Buker, Seda; Ger, Can; Erozden, Ozan; Gurvit, Hakan; Saydam, Bilgin
Introduction: Decision-making and emotion recognition are two fundamental themes in social cognition. Disorders in these areas can lead to interpersonal, psychosocial, and legal problems for the individual and society. The likelihood of consequent aggression and crime makes them foci of forensic psychiatry over time. In this study, two developmental disorders that have a clear relationship with crime, that are antisocial personality disorder (ASPD), and psychopathy are investigated for their relationship with these social cognitive deficits. Methods: The present study involved 23 male prison inmates who were diagnosed with both antisocial personality disorder and psychopathy, as well as 23 control participants who were matched for age, gender, and level of education. Following the psychiatric interview, Reading the Mind in the Eyes Test (RMET), the Iowa Gambling Test (IGT), Toronto Alexithymia Scale (TAS), Defense Styles Questionnaire (DSQ), Childhood Psychic Trauma Scale (CTQ), Hare Psychopathy Checklist (PCL-R) were administered to all participants. Results: The results of the study showed that ASPD group performed statistically worse than healthy controls in TAS, CTQ, all items of DSQ, PCL-R Factor 1 and 2, and all the IGT scores (p<0.05). There were no statistically significant difference between in the RMETtest performances Conclusion: These results suggest that ASPD and psychopathy lead to impaired decision-making behaviors due to the inability to recognize one's own emotions and impulsivity, and that these characteristics play a critical role in the criminal behavior of individuals. In addition, contrary to expectations, the results of affective theory of mind assessed with the RMET showed similar characteristics in homicide convicts and healthy controls. These data indicate the need for further research in the field of forensic psychiatry.
Citation - WoS: 8
Citation - Scopus: 11
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 - WoS: 5
Citation - Scopus: 5
The Effect of Weekend Curfews on Epidemics: a Monte Carlo Simulation
(Tubitak Scientific & Technical Research Council Turkey, 2021) Kaygusuz, Hakan; Berker, A. Nihat
The ongoing COVID-19 pandemic is being responded with various methods, applying vaccines, experimental treatment options, total lockdowns or partial curfews. Weekend curfews are among the methods for reducing the number of infected persons, and this method is practically applied in some countries such as Turkey. In this study, the effect of weekend curfews on reducing the spread of a contagious disease, such as COVID-19, is modeled using a Monte Carlo algorithm with a hybrid lattice model. In the simulation setup, a fictional country with three towns and 26,610 citizens were used as a model. Results indicate that applying a weekend curfew reduces the ratio of ill cases from 0.23 to 0.15. The results also show that applying personal precautions such as social distancing is important for reducing the number of cases and deaths. If the probability of disease spread can be reduced to 0.1, in that case, the death ratio can be minimized down to 0.
Citation - WoS: 14
Citation - Scopus: 14
Exploration of the Binding Pocket of Histone Deacetylases: the Design of Potent and Isoform-Selective Inhibitors
(Tübitak, 2017) Auba, Budullahi İbrahim; Yelekçi, Kemal
Histone deacetylases (HDACs) are enzymes that act on histone proteins to remove the acetyl group and thereby regulate the chromatin state. HDACs act not only on histone protein but also nonhistone proteins that are key players in cellular processes such as the cell cycle, signal transduction, apoptosis, and more. “Classical” HDACs have been shown to be promising targets for anticancer drug design and development. However, the selectivity of HDAC inhibitors for HDAC isoforms remains the motivation of current research in this field. Here, we explored Class I HDACs and HDAC6 by sequence alignment and structural superimposition, catalytic channel extraction, and identification of critical residues involved in HDAC catalysis. Based on the general pharmacophore features of known HDAC inhibitors, we developed a library of compounds by scaffold hopping on a fragment hit identified via structurebased virtual screening of the molecular fragment library retrieved from the Otava database. Molecular docking assay revealed five of these compounds to have increased potency and selectivity for HDACs 1 and 2. Furthermore, their predicted absorption, distribution, metabolism, elimination, and toxicity (ADMET) properties were consistent with those of drug-like compounds. With further modelingbased and experimental investigations, we believe that these findings may offer additional potential HDAC inhibitors with improved selectivity
Citation - WoS: 3
Citation - Scopus: 3
Exploring the Space-Calorie Association: Preliminary Evidence From Reaction Time Performance
(Univ Economics & Human Sciences Warsaw, 2021) Gurbuz, Emre; Gokce, Ahu
The present study was designed to investigate the representation of calorie levels in space. Previously an association between numerical magnitude and space has been established, namely, the Spatial Numerical Association of Response Codes (SNARC) effect. The spatial-numerical association reveals representation of smaller and larger numbers by the left and right sides, respectively. In addition, previous studies showed that spatial arrangement of foods in space affects the food selection behavior. In three experiments, the presence of an association between calorie magnitude and space was tested to understand how it could potentially affect food selection behavior. Reaction times were recorded to investigate the speed of information processing. In Experiment 1, locations of low and high calorie food stimuli were (in)congruent in terms of the space-calorie association. In Experiment 2, endogenous spatial cues were used to bias attention to investigate if this bias would lead to formation of the space-calorie association. Finally, Experiment 3 investigated whether green and red colors evoke approach or avoidance behavior and prevent formation of the space-calorie association. In all experiments, results revealed lack of an association between space and calorie, that is, presenting low/high calorie items on the left/right hemispace, respectively, did not modulate the processing speed.
Citation - WoS: 14
Citation - Scopus: 15
Genetic Variations of the Apolipoprotein B Gene in Turkish Patients With Coronary Artery Disease
(Taylor & Francis Ltd, 2005) Duman, Belgin Süsleyici; Türkoğlu, Çavlan; Akpınar, Belhhan; Güden, Mustafa; Vertii, Anastassia; Çağatay, Penbe; Günay, Demet; Büyükdevrim, Ahmet Sevim
Background: The results of studies that clarify the association of genetic markers at the apolipoprotein B (apo B) gene (EcoRI and XbaI polymorphisms) with coronary artery disease (CAD) are not consistent and suggest that the effect is context dependent (dependent on ethnicity and sex). The present study represents the first investigation of the apo B gene polymorphisms in Turkish patients with CAD and their influence on lipid levels. Aim: The study investigated the association of apo B gene EcoRI and XbaI polymorphisms with CAD and with variation in lipid levels (total cholesterol (T-Chol) high-density lipoprotein cholesterol (HDL-Chol) low-density lipoprotein cholesterol (LDL-Chol) and triacylglycerol (TAG)). Subjects and methods: The study group was composed of 150 individuals with angiographically documented CAD and 100 angiographically proven to be healthy controls. PCR-RFLP was used to determine the DNA polymorphisms of the apo B gene. Results: The frequencies of apo B genotypes detected with EcoRI (AA AG GG) and XbaI (CC CT T-F) did not differ significantly between case and control subjects. A significant association between EcoRI genotypes and T-Chol (p <= 0.05) and LDL-Chol (p <= 0.001) was observed only in CAD patients. Patients with the AA genotype had higher levels of serum T-Chol and LDL-Chol compared with AG. With logistic regression analysis the XbaI TT genotype was found to be associated with CAD prevention. However no significant differences in lipid variables were determined for the XbaI polymorphisms in the patients with CAD. Conclusions: Apo B EcoRI genotypes were not found as risk factors for CAD whereas XbaI TT genotype was detected to prevent against CAD in our study group.
Hands-On Docking With Molegro Virtual Docker
(Humana Press Inc., 2026) Dere, D.; Pehlivan, S.N.; da Silva, A.D.; de Azevedo Junior, W.F.
Molegro Virtual Docker (MVD) integrates state-of-the-art search algorithms and scoring functions dedicated to protein-ligand docking simulations. It implements differential evolution as a search engine and MolDock and Plants scores to calculate binding affinity. In this work, we describe a workflow focused on how to build regression models to predict the inhibition of cyclin-dependent kinase 2 (CDK2). We employ available structural and binding data to construct machine learning models to calculate CDK2 inhibition based on the atomic coordinates obtained through docking simulations performed with MVD. We present a hands-on approach to show how to integrate docking results and machine learning methods available at Scikit-Learn to build targeted scoring functions. Our regression models show superior predictive performance compared with classical scoring functions. All CDK2 datasets and Jupyter Notebooks discussed in this work are available at GitHub: https://github.com/azevedolab/docking#readme. We made the source code of the program SAnDReS 2.0 available at https://github.com/azevedolab/sandres. © 2025 Elsevier B.V., All rights reserved.
Citation - WoS: 5
Citation - Scopus: 6
Hemodilution During Off-Pump Coronary Artery Bypass Grafting: Can We Improve Flow and Reduce Hypercoagulability?
(Forum Multimedia Publishing LLC., 2003) Güden, Mustafa; Sanisoğlu, İlhan; Sağbaş, Ertan; Ergenoğlu, Mehmet U.; Özbek, Uğur; Akpınar, Belhhan
Background: The aim of this study was to compare intraoperative coronary graft flows performed on pump and off pump and to evaluate the effects of hemodilution on coronary graft flows in off-pump coronary artery bypass grafting (CABG) patients by using transit time flow measurements (TTFM). Methods: Three hundred patients undergoing only CABG procedures were enrolled in a prospective randomized manner into 3 groups. Group 1 consisted of 100 patients undergoing operations with standard cardiopulmonary bypass techniques. Group 2 consisted of 100 patients scheduled for revascularizations using off-pump techniques. Group 3 consisted of 100 patients who underwent operations with off-pump techniques under controlled hemodilution (hematocrit levels kept between 25% and 28%). TTFM were performed with the coronary Flometer system. Mean flows pulsatility indices and flow patterns were evaluated. Twenty-five patients in each group were randomly assigned for control angiography 6 days postoperatively. Thromboelastographic (TEG) measurements were performed for each patient before and after surgery to evaluate the patient's coagulation status. Results: The mean number of anastomoses was higher in group 1 than in groups 2 and 3 (P < .05). Mean arterial pressures and heart rates were similar between groups during measurements. Hematocrit values were higher in group 2 than in groups 1 and 3 (P < .05). Mean flows for left anterior descending coronary artery and right coronary artery territories were significantly lower in group 2 patients (P < .05). For the circumflex artery territory mean flows did not reach statistically significant levels despite lower flows again in group 2. The pulsatility indices were similar in all 3 groups for all 3 coronary territories. Postoperative coronary angiographic results revealed similar graft patencies among the 3 groups (not significantly different). Postoperative TEG patterns failed to show a hypercoagulable state in off-pump patients. Conclusion: Off-pump CABG patients with hemodilution had significantly higher graft flows than off-pump CABG patients without hemodilution. Although we failed to show the existence of a hypercoagulable state for patients in the off-pump group an examination of the TTFM findings suggests that hemodilution may help to improve graft patency in off-pump CABG patients during the early postoperative period.
Citation - WoS: 2
Citation - Scopus: 2
Modelling of C-Terminal Tail of Human Sting and Its Interaction With Tank-Binding Kinase 1
(Tubitak Scientific & Technical Research Council Turkey, 2022) Ata Ouda Al-Masri, Rahaf; Audu-Bida, Hajara; Essiz, Sebnem
Stimulator of interferon genes (STING) plays a significant role in a cell's intracellular defense against pathogens or self DNA by inducing inflammation or apoptosis through a pathway known as cGAS-cGAMP-STING. STING uses one of its domains, the C-terminal tail (CTT) to recruit the members of the pathway. However, the structure of this domain has not been solved experimentally. STING conformation is open and more flexible when inactive. When STING gets activated by cGAMP, its conformation changes to a closed state covered by 4 beta-sheets over the binding site. This conformational change leads to its binding to Tank-binding kinase 1 (TBK1). TBK1 then phosphorylates STING aiding its entry to the cell's nucleus. In this study, we focused on the loop modeling of the CTT domain in both the active and inactive STING conformations. After the modeling step, the active and inactive STING structures were docked to one of the cGAS-cGAMP-STING pathway members, TBK1, to observe the differences of binding modes. CTT loop stayed higher in the active structure, while all the best-scored models, active or inactive, ended up around the same position with respect to TBK1. However, when the STING poses are compared with the cryo-EM image of the complex structure, the models in the active structure chain B displayed closer results to the complex structure.
Citation - WoS: 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 - Scopus: 17
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 - Scopus: 6
The Prevalence of Microalbuminuria and Relevant Cardiovascular Risk Factors in Turkish Hypertensive Patients
(2011) Kozan,Ö.; Özcan,E.E.; Sancaktar,O.; Kabakci,G.; Sözcüer,A.H.; Kerpeten,A.; Tartan,Z.
Objectives: A growing body of data illustrates the importance of microalbuminuria (MAU) as a strong predictor of cardiovascular risk in the hypertensive population. The present study was designed to define the prevalence of MAU and associated cardiovascular risk factors among Turkish hypertensive outpatients. Study design: Representing the Turkish arm of the multinational i-SEARCH study involving 1,750 sites in 26 countries around the world, a total of 1,926 hypertensive patients from different centers were included in this observational and cross-sectional survey study. Patients with reasons for a false-positive MAU test were excluded. The prevalence of MAU was assessed using a dipstick test, and patients were inquired about comorbidities, comedication, and known cardiovascular risk factors. Results: The overall prevalence of MAU was 64.7% and there was no difference between genders. Most of the patients (82.5%) had uncontrolled hypertension, 35.6% had dyslipidemia, and 35.5% had diabetes, predominantly type 2. Almost one-third of the patients (26.4%) had at least one cardiovascular-related comorbidity, with 20.3% having documented coronary artery disease (CAD). Almost all patients (96.8%) had one or more risk factors for cardiovascular disease in addition to hypertension, including family history of myocardial infarction or CAD, diabetes, dyslipidemia, lack of physical exercise, and smoking. A trend towards higher MAU values in the presence of CAD was determined. Conclusion: Microalbuminuria tests should be routinely used as a screening and monitoring tool for the assessment of subsequent cardiovascular morbidity and mortality among hypertensive patients. © 2011 Turkish Society of Cardiology.
Citation - WoS: 7
Citation - Scopus: 8
A Radiofrequency modified maze and valve procedure through a port-access approach
(Forum Multimedia Publishing LLC., 2003) Güden, Mustafa; Akpınar, Belhhan; Sağbaş, Ertan; Sanisoğlu, İlhan; Ergenoğlu, Mehmet U.; Özbek, Uğur
Background: The aim of the study was to assess the feasibility and effectiveness of the irrigated radiofrequency modified maze procedure through a port-access approach during mitral valve surgery. Methods: Forty-three patients with atrial fibrillation (AF) and mitral valve disease underwent a combined procedure through a port-access approach. The indication was a history of continuous AF for more than 6 months in patients eligible for minimally invasive mitral valve surgery. Results: The incidence of early mortality was 1 patient (2.3%) and that of freedom from AF was 100% at the end of the operation (70% of patients with normal sinus rhythm 30% with a pacemaker). One patient (2.3%) required permanent pacemaker implantation after surgery. One patient (2.3%) required reoperation for bleeding. There were no reoperations for failed valve repairs. The incidences of freedom from AF were 87% and 92% at 6 and 12 months respectively. At 12 months functional capacity had improved significantly (P < .05). There were no procedure-related complications. No thromboembolic events were detected during follow-up. Conclusion: The port-access approach provided a good access for both valve surgery and the radiofrequency maze procedure. The combination of direct and videoscopic vision allowed an adequate view and led to a safe and efficient combined procedure. Short- and intermediate-term follow-up results were favorable.
Time Flow Measurements (ttfm) Differ Between Grafts Do Transit Performed on and Off-Pump Cabg? a Comparitive Study
(Forum Multimedia Publishing LLC., 2002) Güden, Mustafa; Akpinar, Belhhan; Sağbaş, Ertan; Sanisoğlu, İlhan; Bayındır, Osman
Background: The aim of this study was to compare intraoperative coronary graft flows performed on and off-pump and to evaluate the effects of hemodilution on coronary graft flows in off-pump CABG patients by using TTFM. Materials and Methods: During a one year period 150 patients undergoing a CABG only procedure were enrolled in a prospective randomized manner. Group 1 consisted of 50 patients undergoing CABG using standard CPB techniques. Group 2 consisted of 50 cases who were planned to undergo revascularization using off-pump techniques. Group 3 consisted of 50 patients undergoing CABG using off-pump techniques under controlled hemodilution. (Htc% levels were kept between a range of 25-28%.) TTFM were performed using the CTS (Cardiothoracic Systems) - USA flometer. Mean Flows (Qmed) Pulsatile _ndex (PI) and flow patterns were evaluated. Twenty-five patients in each group were randomly assigned for control angiography 6 days postoperatively. Reoperations combined cases and emergency operations were not included. Patients requiring high doses of vasoactive drugs were also excluded for the benefit of a controlled vascular resistance. Results: The mean number of anastomoses were higher in Group 1 when compared to Group 2 and 3. (p < 0.05) Mean Arterial Pressure (MAP) heart rate (HR) were similar between groups during measurements. Hematocrit values in Group 2 were higher than Group 1 and Group 3 (p < 0.05). Mean flows (Qmed) for LAD and RCA territories were significantly lower in Group 2 patients (p < 0.05) For the circumflex artery territory despite lower flows again in Group 2 this did not reach significant levels. The pulsatile index were similar in all three groups for all three coronary territories. Postoperative coronary angiography revealed similar graft patencies among three groups (p = ns). All values are shown as mean + SD unless expressed otherwise. The Kruskal-Wallis H test was used for analysing differences between three groups. Dunn's Multiple Comparison test was used for sub-group analysis p < 0.05 was considered significant. Conclusions: Off-pump CABG patients with hemodilution had significantly higher graft flows compared to off-pump CABG patients without hemodilution. It can be hypothesed that hemodilution may help to improve graft patency during the early postoperative period in off-pump CABG patients.

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