Browsing by Author "Dogan A."
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Item A rare cause of reversible dilated cardiomyopathy: Hypocalcemia(2004) Avsar A.; Dogan A.; Tavli T.Hypocalcemia is a rare cause of reversible heart failure. We reported a 40-year-old woman who had severe heart failure resistant to the usual antifailure therapy. She had severe hypocalcemia due to hypoparathyroidism after strumectomy. Echocardiography showed a large left ventricle with very low ejection fraction of 25% and moderate mitral regurgitation. After supplementation of calcium and vitamin D, her clinical situation and hemodynamics improved rapidly. At 15 months, myocardial impairment resolved fully. In conclusion, hypocalcemia should be considered in the differential diagnosis of resistant severe heart failure.Item Effect of difluoromethylornithine on reperfusion injury after temporary middle cerebral artery occlusion(2005) Temiz C.; Dogan A.; Baskaya M.K.; Dempsey R.J.Polyamines have been shown to play an important role in the disturbance of the blood-brain barrier (BBB) in a number of pathological states including ischemia. BBB disturbances may be almost completely prevented by treating animals with the ornithine decarboxylase (ODC) inhibitor, α- difluoromethylornithine (DFMO). DFMO has been also shown to prevent N-Methyl-d-aspartate (NMDA) toxicity in tissue cultures. It has been suggested that the pathological disturbances in polyamine metabolism observed following cerebral ischemia, particularly the post-ischemic increase in putrescine, may contribute to the ischemic injury that is most evident in the CA1 subfield of the hippocampus. In this study, effects of DFMO in cerebral ischemia and reperfusion were examined. The results showed that inhibition of the polyamine system by DFMO decreased ischemic injury volume and brain tissue water content in a dose-dependent manner, without change in vital signs, including systemic arterial blood pressure, arterial partial oxygen pressure, regional cerebral blood flow and body temperature. © 2005 Published by Elsevier Ltd.Item Plasma lipoprotein(a) levels in patients with slow coronary flow(2013) Yucel H.; Dogan A.; Altinbas A.; Akcay S.; Icli A.; Ceyhan B.M.Introduction: Slow coronary flow (SCF) is a microvascular disorder characterized by delayed opacification of coronary vessels with normal coronary angiogram. It may be due to endothelial dysfunction and diffuse atherosclerosis. Lipoprotein(a) [Lp(a)] is related to cardiovascular events. Plasma Lp(a) levels have not been studied previously in SCF patients. Aim: We investigated plasma Lp(a) and fibrinogen levels, and their relation to coronary flow rate in patients with SCF. Material and methods: This cross-sectional study included 50 patients with SCF and 30 age- and sex-matched controls who had normal coronary arteries and normal flow. Coronary flow rates of patients and controls were counted with the thrombolysis in myocardial infarction (TIMI) frame count. Plasma Lp(a) and fibrinogen levels were measured in SCF patients and controls, with routine biochemical tests. Results: There were no significant differences between the two groups with respect to plasma Lp(a) (21 mg/dl vs. 14 mg/dl, p = 0.11) and fibrinogen (278 mg/dl vs. 291 mg/dl, p = 0.48) levels. The TIMI frame count was not correlated with plasma Lp(a) (r = 0.13, p = 0.25) or fibrinogen (r = -0.14, p = 0.28) levels. Conclusions: Our results show that there is no significant association between SCF and Lp(a) and fibrinogen levels.Item Increased mean platelet volume in hypertrophic cardiomyopathy(SAGE Publications Inc., 2014) Icli A.; Aksoy F.; Dogan A.; Arslan A.; Akcay S.; Yücel H.; Ersoy I.; Gorgulu O.Thromboembolic events may be seen in patients with hypertrophic cardiomyopathy (HCM). We investigated the mean platelet volume (MPV), an indicator of platelet activation in patients with HCM. This study included 112 patients with HCM, in which 40 were patients with hypertrophic obstructive cardiomyopathy (HOCM), and 106 were control participants. The MPV was significantly higher in patients with HCM than in controls (9.1 ± 0.3 vs 7.9 ± 0.3 fL, P =.01). In the subgroup analyses, MPV was also higher in patients with HOCM compared to those with hypertrophic nonobstructive cardiomyopathy (HNCM; 9.3 ± 0.3 vs 9.0 ± 0.2 fL, P =.01). Similarly, patients with HNCM had higher MPV values than controls (9.0 ± 0.2 vs 7.9 ± 0.3 fL, P =.01). The MPV was significantly and positively correlated with left ventricular outflow tract (LVOT) obstruction (r =.42, P =.001) and septal thickness (r =.62, P =.001). In linear regression analysis, MPV was independently associated only with septal thickness (β =.07, 95% confidence interval: 0.04-0.09, P =.001). The MPV can be elevated in patients with HCM regardless of the obstruction of LVOT and may be associated with the severity of septal thickness. © The Author(s) 2013.Item Effects of axial impacts at different temperatures on failure response of adhesively bonded woven fabric glass fiber/epoxy composite joints(SAGE Publications Ltd, 2015) Sayman O.; Soykok I.F.; Dogan T.; Dogan A.; Arikan V.Evaluating post-impact failure responses of single-lap adhesively bonded composite-to-composite joints in uniaxial static tensile loading was the main objective of the current experimental study. At first, axial tensile impacts having various energy levels (10, 15, 20, and 25 J) were applied to the joints at different temperatures (-20, 0, room temperature, 50, and 80). Afterward, the samples were secondarily subjected to static tensile loading at ambient temperature, so that reductions in joint strengths arising from the impacts performed under different loading conditions could be assessed. Consequently, it was definitely proved that each of the axial impacts performed in any loading case has a noticeable effect on ultimate joint strengths, proportionally to the acting condition. Besides, the combination of high energy and temperature sometimes appeared to be the reason of impact failure, which occurs instantly without being able to perform axial static tests. When applied energy and/or absolute difference from room temperature is increased, lower joint resistances could be measured during secondary tensile tests. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.Item Lymphovascular space invasion and cervical stromal invasion are independent risk factors for nodal metastasis in endometrioid endometrial cancer(Blackwell Publishing, 2015) Solmaz U.; Mat E.; Dereli M.; Turan V.; Gungorduk K.; Hasdemir P.; Tosun G.; Dogan A.; Ozdemir A.; Adiyeke M.; Sanci M.Aims: The purpose of this study was to investigate the potential roles of pathological variables in the prediction of nodal metastasis in women with endometrioid endometrial cancer (EC). Materials and Methods: Women who underwent surgery for endometrioid EC between 1995 and 2012 were retrospectively reviewed. Those who underwent prior neoadjuvant chemotherapy or radiotherapy and inadequate lymphadenectomy as well as those with nonendometrioid histology, synchronous cancers, International Federation of Gynecology and Obstetrics stage IV disease, gross uterine serosal and/or gross adnexal involvement were excluded. Lymph node dissemination was defined as occurring in the following circumstances: (i) when nodal metastasis with pelvic and/or para-aortic (P/PA) lymph node dissection (LND) was performed or (ii) when there was recurrence in the P/PA lymph nodes after a negative LND or when LND was not performed. Univariate and multivariate logistic regression models were used to identify the pathological predictors of lymphatic dissemination. Results: A total of 827 women with endometrioid EC were assessed; 516 (62.4%) of whom underwent P/PA LND and 205 (24.8%) underwent P LND. Sixty-seven (13%) women in the P/PA LND group and 5 (2.4%) in the P LND group had positive lymph nodes. Multivariate analysis confirmed cervical stromal invasion (OR 4.04, 95% CI 2.02-8.07 (P < 0.001)) and lymphovascular space invasion (LVSI) (OR 110.18, 95% CI 38.43-315.87 (P < 0.001)) as independent predictors of lymphatic dissemination. Conclusion: Cervical stromal invasion and LVSI are highly associated with LN metastasis. These markers may serve as a surrogate for nodal metastasis. © 2015 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.Item Analysis of clinical and pathological characteristics, treatment methods, survival, and prognosis of uterine papillary serous carcinoma(Wichtig Publishing Srl, 2016) Solmaz U.; Ekin A.; Mat E.; Gezer C.; Dogan A.; Biler A.; Peker N.; Hasdemir P.S.; Sanci M.Purpose: Uterine papillary serous carcinoma (UPSC) is an atypical variant of endometrial carcinoma with a poor prognosis. It is commonly associated with an increased risk of extrauterine disease. The aim of this study was to investigate clinical and pathological characteristics, therapeutic methods, and prognostic factors in women with UPSC. Methods: All patients who underwent surgery for UPSC at a single high-volume cancer center between January 1995 and December 2010 were retrospectively reviewed. Patients who did not undergo surgical staging and those with mixed tumor histology were excluded. Univariate and multivariate regression models were used to identify the risk factors for overall survival (OS) and progression-free survival (PFS). Results: A total of 46 patients were included, the majority of whom having stage I disease (IA, 13 [28.2%] and IB, 12 [26.7%]). Stages II, III, and IV were identified in 5 (10.9%), 8 (17.4%), and 8 (17.4%) women, respectively. Optimal cytoreduction was obtained in 67.3% of patients. Recurrences developed in 8 (17.4%) patients. Multivariate analysis confirmed that lymphovascular space invasion (LVSI) (odds ratio [OR] 26.83, p = 0.003) was the only independent prognostic factor for OS, whereas LVSI and optimal cytoreduction were found to be independent prognostic factors for PFS (OR 6.91, p = 0.013 and OR 2.69, p = 0.037, respectively). The 5-year overall survival rate was 63%. Conclusions: Our study demonstrated that LVSI is the only independent prognostic factor for OS, whereas LVSI and optimal cytoreduction are independent prognostic factors for PFS in patients with UPSC. © 2016 Wichtig Publishing.Item The clinicopathological features and survival of Castleman disease: A multicenter Turkish study(Verduci Editore s.r.l, 2022) Yildiz J.; Bagci M.; Sayin S.; Kaya A.; Yilmaz F.; Ekinci O.; Dal M.S.; Basturk A.; Aydogdu I.; Albayrak M.; Dogan A.; Erkurt M.A.; Korkmaz S.; Ulas T.; Eser B.; Altuntas F.Objective: In this study, we aimed to investigate the clinicopathological features and survival of CD, which is quite rare and has many unknowns. Patients and Methods: This study was conducted by retrospectively evaluating patients diagnosed with CD in six different centers in Turkey. Results: The median age of 33 patients included in the study was 49 and 51.5% (n = 17) of these patients were women. 18 (54.5%) patients were in the hyaline vascular subtype and most of the patients were UCD (n = 20, 60.6%). The most common involvement region was head and neck (n = 19, 57.5%). The UCD group was younger than the MCD group (p=0.027). Visceral lymph node involvement was higher in MCD than in UCD (p=0.001). Similarly, it was observed that there was more hepatomegaly (p=0.035) and splenomegaly (p=0.013) in the MCD group. During the median 19.5 months follow-up period, there were no patients who died. Conclusions: It was observed that UCD and MCD are different clinical entities. Promising survival times can be achieved with surgical and systemic treatments in both subtypes of this extremely rare disease. However, this result should be supported by well-designed prospective comprehensive studies. © 2022 Verduci Editore s.r.l. All rights reserved.Item Determination of periodic deformation from InSAR results using the FFT time series analysis method in Gediz Graben(Springer Science and Business Media B.V., 2023) Hastaoglu K.O.; Poyraz F.; Erdogan H.; Tiryakioglu I.; Ozkaymak C.; Duman H.; Gul Y.; Guler S.; Dogan A.Permanent Scatterers (PS) point velocities obtained by the interferometric synthetic aperture radar (InSAR) method are generally determined using the linear regression model, which ignores periodic and seasonal effects. In this study, software was developed that can detect periodic effects by applying fast Fourier transformation (FFT) time series analysis to InSAR results. Using the FFT time series analysis, the periodic components of the surface movements at the PS points were determined, and then the annual velocity values free from periodic effects were obtained. The study area was chosen as the Gediz Graben, a tectonically active region where aseismic surface deformations have been observed in recent years. As a result, using the developed method, seasonal effects were successfully determined with the InSAR method at the PS points in the study area with a period of 384 days and an average amplitude of 19 mm. In addition, groundwater level changes of a water well in the region were modeled, and 0.93 correlation coefficient values were calculated between seasonal InSAR displacement values and water level changes. Thus, using the developed methodology, the relationship between the tectonic movement in the Gediz Graben in Turkey and the seasonal movements and the change in the groundwater level was determined. © 2023, The Author(s), under exclusive licence to Springer Nature B.V.