Tıp Fakültesi / Faculty of Medicine
Permanent URI for this collectionhttps://hdl.handle.net/11727/1403
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Item Aspirin Resistance in Cerebrovascular Disease and the Role of Glycoprotein IIIa Polymorphism in Turkish Stroke Patients(2016) Derle, Eda; Ocal, Ruhsen; Kibaroglu, Seda; Celikkol, Ceyda; Bayraktar, Nilufer; Verdi, Hasibe; Atac, Belgin F.; Can, Ufuk; https://orcid.org/0000-0002-3964-268X; https://orcid.org/0000-0002-7886-3688; https://orcid.org/0000-0003-0591-009X; https://orcid.org/0000-0001-6868-2165; https://orcid.org/0000-0001-8689-417X; 26809135; V-3553-2017; AAJ-2956-2021; Y-8758-2018; V-5499-2017; ABG-9966-2020; AAJ-2999-2021Aspirin resistance occurs in 5-45% of high-risk patients, with various mechanisms proposed for its development. This study aimed to determine the relationships among aspirin resistance, aspirin dosage, type of aspirin and glycoprotein IIIa P1A1/A2 polymorphism in patients with vascular risk factors. Two hundred and eight (75 symptomatic, 133 asymptomatic) patients with vascular risk factors who were using aspirin for primary or secondary prevention were prospectively included. The symptomatic group was further classified into two groups according to aspirin use at the time of stroke. Aspirin resistance was measured by the PFA-100 system (collagen/epinephrine cartridge) and glycoprotein IIIa P1A1/A2 polymorphism was determined by PCR. The overall prevalence of aspirin resistance was 32.2%. The mean age of patients with aspirin resistance was significantly higher than that in those who did not have resistance (P=0.009). The prevalence of aspirin resistance was similar for the symptomatic and asymptomatic under aspirin therapy groups. The resistance rate was found to be highest with 100mg enteric-coated preparation use (39.3%). Increasing the aspirin dosage and/or shifting to uncoated preparations caused a change in aspirin sensitivity of 36-60%. Repeated measurements showed development of aspirin resistance in 14% of patients who were sensitive to aspirin in previous measurements. Glycoprotein IIIaP1A1/A2 polymorphism, aspirin resistance and development of atherothrombotic stroke were not significantly related. The effect of aspirin can change by time, dosage and type of preparation used. There are no relationships among glycoprotein IIIa P1A1/A2 polymorphism, aspirin resistance and development of atherothrombotic stroke. Copyright (C) 2016 Wolters Kluwer Health, Inc. All rights reserved.Item Association between Hypoxia Parameters with White Matter Hyperintensity and Silent Cerebral Infarcts on Brain Magnetic Resonance Images in Patients with Obstructive Sleep Apnea(2016) Avci, Aynur Yilmaz; Avci, Suat; Lakadamyali, Huseyin; Lakadamyali, Hatice; Can, Ufuk; 0000-0003-2155-8014; 0000-0001-9004-9382; 0000-0001-8689-417X; O-3636-2018; F-6770-2019; AAJ-2999-2021Objective: This study evaluated the association between hypoxia parameters with white matter hyperintensity (WMH) and silent cerebral infarcts (SCI) on brain magnetic resonance (MR) images of patients with obstructive sleep apnea (OSA). Methods: In this retrospective study, the study group was composed of 453 patients who were evaluated by overnight polysomnography (PSG). Data on hypoxia parameters, such as total sleep duration with oxygen saturation < 90% (ST90), percentage of cumulative time with oxygen saturation < 90% (CT90), and the lowest oxygen saturation (min SaO(2)), were obtained from PSG. The presence of WMH and SCI was evaluated in all participants using brain MR images. Results: Hypoxia parameters, such as ST90, CT90, and min SaO(2), were significantly associated with WMH (P < 0.001). The multiple regression analysis showed that CT90 was independently associated with SCI (P = 0.038). In addition, when participants were divided into two groups according to CT90 < 10% and CT90 = 10%, age (P = 0.002), sex (P = 0.015), body mass index, Apnea-Hypopnea Index score, Epworth Sleepiness Scale score, and the presence of WMH, hypertension, and diabetes mellitus were significantly higher in the CT90 = 10% group compared with the CT90 < 10% group (P < 0.001 for all parameters). CT90 = 10% increased the risk of WMH 2.34-fold (95% confidence interval, 1.44-3.85; P = 0.006). Conclusion: The severity of nocturnal intermittent hypoxia may contribute to the pathogenesis of WMH and SCI in patients with OSA.Item Alteratıon of Mean Platelet Volume in The Pathogenesıs of Acute Ischemıc Stroke: Cause or Consequence?(2018) Ayas, Zeynep Ozozen; Can, Ufuk; https://orcid.org/0000-0001-8689-417X; 29465900; AAJ-2999-2021Introduction - Platelets have a crucial role on vascular disease which are involved in pathogenesis of ischemic stroke. Platelet size is measured as mean platelet volume (MPV) and is a marker of platelet activity. Platelets contain more dense granules as the size increases and produce more serotonin and tromboglobulin (p-TO) than small platelets. In this study, the alteration of MPV values were investigated in patients with acute stroke, who had MPV values before stroke, during acute ischemic stroke and 7 days after the stroke. The relationship between this alteration and risk factors, etiology and localization of ischemic stroke were also investigated. Methods - Sixty-seven patients with clinically and radiologically established diagnoses of ischemic stroke were enrolled into the study and stroke etiology was classified by modified Trial of Org 10 172 in Acute Stroke Treatment (TOAST) classification and, modified Bamford classification was used for localization and stroke risk factors were also evaluated. The platelet counts and MPV values from patient files in patients who had values before stroke (at examination for another diseases), within 24 hours of symptom onset and after 7 further days were analysed. Results - MPV values increased after stroke (10.59 +/- 2.26) compared with acute stroke values (9.84 +/- 1.64) and the values before stroke (9.59 +/- 1.72) (p<0.0001); this alteration of MPV values occured 7 days after stroke (p<0.016). There was a positive correlation between age and MPV values during acute stroke (r=0.270; p<0.05). Patients with atrial fibrillation had higher alteration in the time of MPV compared with patients without atrial fibrillation (p>0.006). We assessed for gender, men (n=38) had a higher alteration in the time of MPV compared with women (n=29) (p=0.013). Conclusion - Although there was no alteration of platelet counts, MPV values were increased 7 days after stroke in patients with acute ischemic stroke.Item Left Atrial Mechanics For Secondary Prevention From Embolic Stroke Of Undetermined Source(2022) Sade, Leyla Elif; Keskin, Suzan; Can, Ufuk; Colak, Ayse; Yuce, Deniz; Ciftci, Orcun; Ozin, Bulent; Muderrisoglu, Haldun; https://orcid.org/0000-0003-3737-8595; 33206942; AAQ-7583-2021Aims Anticoagulation is not justified unless atrial fibrillation (AF) is detected in cryptogenic stroke (CS) patients. We sought to explore whether left atrial (LA) remodelling is associated with embolic stroke of undetermined source (ESUS). Methods and results In this prospective study, we evaluated consecutively 186 patients in sinus rhythm who presented with an acute ischaemic stroke (embolic and non-embolic) and sex- and age-matched controls. We performed continuous electrocardiogram (ECG) monitoring to capture paroxysmal AF episodes as recommended by the guidelines. After 12 months of follow-up, continuous ECG monitoring was repeated in patients with undetected AF episodes. We quantified LA reservoir and contraction strain (LASr and LASct) by speckle-tracking, LA volumes by 3D echocardiography. Out of 186 patients, 149 were enrolled after comprehensive investigation for the source of ischaemic stroke and divided into other cause (OC) (n = 52) and CS (n = 97) groups. CS patients were also subdivided into AF (n = 39) and ESUS (n = 58) groups. Among CS patients, LA strain predicted AF independently from CHARGE-AF score and LA volume indices. ESUS group, despite no captured AF, had significantly worse LA metrics than OC and control groups. AF group had the worst LA metrics. Moreover, LASr predicted both CS (embolic stroke with and without AF) and ESUS (embolic stroke with no detected AF) independently from LAVImax and CHA(2)DS(2)-VASc score. LASr >26% yielded 86% sensitivity, 92% specificity, 92% positive, and 86% negative predictive values for the identification of ESUS (areas under curve: 0.915, P < 0.0001, 95% confidence interval: 0.86-0.97). Conclusion Echocardiographic quantification of LA remodelling has great potential for secondary prevention from ESUS.