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Dive into the research topics where Meltem Kilercik is active.

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Featured researches published by Meltem Kilercik.


Interactive Cardiovascular and Thoracic Surgery | 2008

The impact of allogenic red cell transfusion and coated bypass circuit on the inflammatory response during cardiopulmonary bypass: a randomized study

Sahin Senay; Fevzi Toraman; Serdar Gunaydin; Meltem Kilercik; Hasan Karabulut; Cem Alhan

OBJECTIVES This study is designed to determine and compare the effects of transfusion and coated circuits on the inflammatory response during cardiopulmonary bypass. METHODS Forty patients were randomized into two groups according to the type of extracorporeal circuit used and later prospectively enrolled into two subgroups according to the need for red cell transfusion during CPB (leading to 4 groups--10 patients per group; group 1: with no transfusion and standard oxygenator, group 2: with transfusion and standard oxygenator, group 3: with no transfusion and coated oxygenator, group 4: with transfusion and coated oxygenator). Serum lactate, interleukin 6, human tumor necrosis factor alpha (TNF-alpha), D-dimer and CRP levels were measured at three time points (T1: start of CPB, T2: before removal of aortic cross-clamp, T3: 45 min after the completion of proximal anastomoses). Protein adsorption of oxygenator fibers was measured. Outcome parameters were recorded. RESULTS Interleukin 6, TNF-alpha, D-dimer and lactate levels increased at T2 and T3 in all groups (P<0.05 within groups). The increase in interleukin 6 was significant at T2 in group 2 when compared to group 1 (8.0+/-3.9 vs. 4.4+/-1.8, P=0.03). The increase in TNF-alpha was higher at T2 in group 1 when compared to group 3 (16.0+/-4.2 vs. 11.7+/-2.8, P=0.05) and in group 2 when compared to group 3 at T2 and T3 (15.3+/-4.6 vs. 11.7+/-2.8, P=0.06; 17.6+/-5.0 vs. 13.7+/-3.9, P=0.06). Protein adsorption was higher in group 1 and group 2 (group 1 vs. group 3, 2.2+/-0.8 vs. 1.4+/-0.3, P=0.01; group 2 vs. group 3, 2.4+/-0.7 vs. 1.4+/-0.3, P=0.02; group 2 vs. group 4, 2.4+/-0.7 vs. 1.8+/-0.3, P=0.04), it was also higher at group 4 when compared to group 3 (1.8+/-0.3 vs. 1.4+/-0.3, P=0.03). CONCLUSIONS Allogenic red cell transfusion enhances inflammatory response during CPB; coated circuit systems have a limiting effect on this inflammatory reaction.


Accreditation and Quality Assurance | 2015

A new approach to calculating the Sigma Metric in clinical laboratories

Abdurrahman Coskun; Mustafa Serteser; Meltem Kilercik; Fehime Benli Aksungar; Ibrahim Unsal

In clinical laboratories, the performance of a process as Sigma Metric (SM) is calculated by the equations derived by Westgard. In the present study, we found that the Westgard equations do not reflect the real performance of the process and that the SM calculated using these equations is lower than the real SM. We measured the substance concentration of ten analytes (glucose, urea, creatinine, cholesterol, calcium, magnesium, phosphorus, LDH, sodium, and potassium) in serum and calculated the SM for each using the Westgard equations and z transformations. The SM values for the same measurand using the Westgard equations based on either the absolute or the relative (percentage) results were not equal to each other, and those related to calcium and sodium were even lower than 0. The SM obtained from the z transformation was higher than that from the Westgard equations, and none were lower than 0. We concluded that the equations suggested by Westgard to calculate the SM do not cover all of the data produced by the process and do not reflect reality. From our research, the z transformation was the optimum method of calculating the actual SM for the process.


Journal of Medical Biochemistry | 2017

Analysis of Changes in Parathyroid Hormone and 25 (OH) Vitamin D Levels with Respect to Age, Gender and Season: A Data Mining Study

Muhittin Serdar; Başar Batu Can; Meltem Kilercik; Zeynep Aslıhan Durer; Fehime Benli Aksungar; Mustafa Serteser; Abdurrahman Coskun; Aysel Ozpinar; Ibrahim Unsal

Summary Background: 25 (OH) vitamin D3 (25(OH)D) and parathyroid hormone (PTH) are important regulators of calcium homeostasis. The aim of this study was to retrospectively determine the cut–off for sufficient 25(OH)D in a four-season region and the influence of age, seasons, and gender on serum 25(OH)D and PTH levels. Methods: Laboratory results of 9890 female and 2723 male individuals aged 38.8±22.1 years who had simultaneous measurements of 25(OH)D and PTH were retrospectively analyzed by statistical softwares. Serum 25(OH)D and PTH levels were measured by a mass spectrometry method and by an electrochemiluminescence immunoassay, respectively. Results: Mean serum 25(OH)D levels showed a sinusoidal fluctuation throughout the year and were significantly (p<0.01) higher in summer and autumn. On the other hand, PTH levels were significantly higher (p<0.01) in women and showed an opposite response to seasonal effects relative to 25(OH)D. Lowest levels of 25(OH)D were detected in people aged between 20 and 40 years whereas PTH hormone levels were gradually increasing in response to aging. The significant exponential inverse relationship that was found between PTH and 25(OH)D (PTH=exp(4.12–0.064*sqrt(25(OH)D)) (r=−0.325, R–squared=0.105, p<0.001)) suggested that the cut–off for sufficient 25(OH)D should be 75 nmol/L. Conclusions: Our retrospective study based on large data set supports the suitability of the currently accepted clinical cut–off of 75 nmol/L for sufficient 25(OH)D. However, the issue of assessing Vitamin D deficiency remains difficult due to seasonal variations in serum 25(OH)D. Therefore, PTH measurements should complement 25(OH)D results for diagnosing Vitamin D deficiency. It is imperative that seasonally different criteria should be considered in future.


International Immunopharmacology | 2014

Increased eNOS levels in hereditary angioedema.

Mustafa Demirtürk; Aslı Gelincik; Suzan Cinar; Meltem Kilercik; Evren Önay-Uçar; Bahattin Çolakoğlu; Nazli Arda; Suna Büyüköztürk; Gunnur Deniz

BACKGROUND Hereditary angio-edema (HAE), characterized by recurrent episodes of angioedema involving the skin and the mucosa of the upper respiratory or the gastrointestinal tracts, results from heterozygosity for deficiency of the serine proteinase inhibitor (serpin), C1 inhibitor (C1-INH). OBJECTIVE In this study, serum inflammatory cytokine levels and circulating endothelial cells collected from HAE patients during both acute attacks and asymptomatic periods were evaluated. METHOD Twenty-four patients with Type I and 1 patient with Type II HAE in an asymptomatic period (Group I), 8 patients with Type I HAE during a mild to moderate acute attack (Group II) and 20 healthy subjects (13 females, mean age: 32.1±8.2years) were included. Serum IL-6, IL-8, IL-1β, TNF-α, vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) levels were detected by ELISA. Circulating endothelial cells (CECs) and circulating endothelial progenitors (CEPs) were evaluated using Fluorescence Activated Cell Sorting (FACS). RESULTS Serum eNOS levels of HAE patients were significantly higher than healthy subjects (p<0.006) while mean TNF-α levels in Group I were slightly lower (p<0.03) than Group II. There were no differences in terms of other inflammatory cytokines between the control subjects and HAE patients who were either in an asymptomatic period or experiencing an acute attack. CECs and CEPs were also similar. CONCLUSION These results suggest that an inflammatory response is not necessary to trigger HAE attacks. On the other hand, increased eNOS levels might reflect a sustained hyperpermeability state in HAE patients.


Biochemia Medica | 2014

Biological variations of ADAMTS13 and von Willebrand factor in human adults

Meltem Kilercik; Abdurrahman Coskun; Mustafa Serteser; Deniz Inan; Ibrahim Unsal

Background: The ultra-large von Willebrand factor (vWF) multimers are very active and must be degraded by ADAMTS13 for optimal activity. A severe functional deficiency of ADAMTS13 has been associated with thrombotic thrombocytopenic purpura. The correct interpretation of patient vWF and ADAMTS13 plasma levels requires an understanding of the biological variation associated with these analytes. In the present paper, we aimed to determine the biological variation of ADAMTS13 and vWF in human adults. Materials and methods: Blood samples were collected weekly from 19 healthy subjects for 5 consecutive weeks. vWF activity and antigenicity were determined using aggregometric and immunoturbidimetric methods. ADAMTS13 antigenicity and activity were determined by ELISA. Results: The within-subject biological variations for vWF activity and antigenicity were 8.06% and 14.37%, respectively, while the between-subject biological variations were 18.5% and 22.59%, respectively. The index of individuality for vWF activity was 0.44, while vWF antigenicity was 0.64. Similarly, ADAMTS13 activity and antigenicity within-subject biological variations were 12.73% and 9.75%, respectively, while between-subject biological variations were 9.63% and 6.28%, respectively. The ADAMTS13 indexes of individuality were 1.32 and 1.55, respectively. Conclusion: We report high biological variation and individuality in vWF antigenicity and activity levels. However, ADAMTS13 antigenicity and activity displayed high biological variation, but low individuality. Thus, population-based reference intervals may be useful for monitoring ADAMTS13 antigenicity and activity, but not for vWF, which displays high individuality. These findings should be considered when determining the reference interval and other clinical variables associated with ADAMTS13 and vWF levels.


Heart Surgery Forum | 2015

Comparative Effects of Hemodilutional Anemia and Transfusion during Cardiopulmonary Bypass on Acute Kidney Injury: A Prospective Randomized Study

Cem Arıtürk; Zehra Serpil Ustalar Ozgen; Meltem Kilercik; Halim Ulugöl; Eyüp Murat Ökten; Uğur Aksu; Hasan Karabulut; Fevzi Toraman

AIM Acute kidney injury after cardiopulmonary bypass has been associated with dilutional anemia during surgery. We aimed both to explore if this relation is modulated by blood transfusion and to understand the postoperative contribution of protein oxidation. METHODS In this randomized prospective study, after ethics committee approval and informed consent, 30 patients undergoing first-time elective coronary artery bypass grafting (CABG) with hematocrit between 21% and 25% at any time during extracorporeal circulation (ECC) were randomly and equally allocated into two groups. Group I consisted of patients who received red blood cells (RBC) during ECC, while in Group II, patients did not receive any RBCs. Besides routine hemodynamic and biochemical parameters, markers of renal injury such as neutrophil gelatinase-associated lipocalin (NGAL), creatinine clearance, and protein oxidation parameters (advanced oxidative protein products [AOPP], total thiol [T-SH]) were determined in both groups. RESULTS (1) Both cardiovascular parameters (MAP, HR) and the hospitalization period of the transfused group were not significantly different compared to the non-transfused group (P > .05); (2) While urine NGAL level (P < .05) increased and GFR (P < .01) decreased in the transfused group compared to the preoperative period, there were no significant changes in respective parameters of the non-transfused group compared to preoperative period; (3) AOPP concentrations did not change compared to postoperative periods in both groups (P > .05). However, T-SH concentration showed a transient increased at postoperative hour 6 (P < .001 vs preoperative period) but normalized at postoperative hour 24 (P > .05 versus preoperative period). CONCLUSION These findings suggest that a hematocrit value over 21% during ECC is safe for renal functions. RBC transfusion just to increase hematocrit may be deleterious.


Journal of Nephrology | 2018

Correction of dilutional anemia induces renal dysfunction in diabetic patients undergoing coronary artery bypass grafting: a consequence of microcirculatory alterations?

Güçlü Aykut; Meltem Kilercik; Cem Arıtürk; Halim Ulugöl; Uğur Aksu; Türkan Kudsioğlu; Nazan Atalan; Nihan Yapici; Hasan Karabulut; Fevzi Toraman

BackgroundIn this study we aimed to evaluate the effects of dilutional anemia resulting from cardiopulmonary bypass (CPB) and its correction with red blood cell (RBC) transfusion on tissue oxygenation and renal function in diabetic patients undergoing coronary artery bypass grafting (CABG).Method70 diabetic patients who underwent elective CABG and whose hematocrit values had been between 24–28% at any time during CBP were prospectively randomized and equally allocated to two groups: patients who received RBC during CPB (group I, n = 35) vs. did not receive RBC during CPB (group II, n = 35). Besides routine hemodynamic and biochemical parameters, biomarkers of ischemia and renal injury such as ischemia modified albumin (IMA), protein oxidation parameters [advanced oxidative protein products (AOPP), total thiol (T-SH)], neutrophil gelatinase-associated lipocalin (NGAL) and estimated glomerular filtration rate (eGFR) were measured in both groups.ResultsIn group I, T-SH, NGAL and urea levels were found to be significantly increased postoperatively compared to preoperative measurements (p < 0.05). Also, postoperatively, NGAL, creatinine, aspartate aminotransferase and AOPP levels were higher in group I than group II (p < 0.05).ConclusionThe correction of anemia with RBC transfusion in diabetic patients undergoing CABG could increase the risk of renal injury. Further studies verifying the effects of blood transfusions at the microcirculatory level are needed to optimize the efficacy of transfusions.


Clinical Chemistry and Laboratory Medicine | 2018

Within-subject and between-subject biological variation estimates of 21 hematological parameters in 30 healthy subjects

Abdurrahman Coskun; Anna Carobene; Meltem Kilercik; Mustafa Serteser; Sverre Sandberg; Aasne K. Aarsand; Pilar Fernandez-Calle; Niels Jonker; William A. Bartlett; Jorge Díaz-Garzón; Sibel Huet; Cansu Kızıltaş; Ilayda Dalgakıran; Esra Ugur; Ibrahim Unsal

Abstract Background: The complete blood count (CBC) is used to evaluate health status in the contexts of various clinical situations such as anemia, infection, inflammation, trauma, malignancies, etc. To ensure safe clinical application of the CBC, reliable biological variation (BV) data are required. The study aim was to define the BVs of CBC parameters employing a strict protocol. Methods: Blood samples, drawn from 30 healthy subjects (17 females, 13 males) once weekly for 10 weeks, were analyzed using a Sysmex XN 3000 instrument. The data were assessed for normality, trends, outliers and variance homogeneity prior to coefficient of variation (CV)-analysis of variance (ANOVA). Sex-stratified within-subject (CVI) and between-subjects (CVG) BV estimates were determined for 21 CBC parameters. Results: For leukocyte parameters, with the exception of lymphocytes and basophils, significant differences were found between female/male CVI estimates. The mean values of all erythrocyte-, reticulocyte- and platelet parameters differed significantly between the sexes, except for mean corpuscular hemoglobin concentration, mean corpuscular volume and platelet numbers. Most CVI and CVG estimates appear to be lower than those previously published. Conclusions: Our study, based on a rigorous protocol, provides updated and more stringent BV estimates for CBC parameters. Sex stratification of data is necessary when exploring the significance of changes in consecutive results and when setting analytical performance specifications.


Annals of Thoracic and Cardiovascular Surgery | 2018

Comparative Effects of Blood and Crystalloid Cardioplegia on Cellular Injury and Oxidative Stress in Cardiovascular Surgery

Halim Ulugöl; Uğur Aksu; Muharrem Kocyigit; Meltem Kilercik; Gulsum Karduz; Murat Ökten; Fevzi Toraman

Purpose: The purpose of this study was to evaluate the effect of different cardioplegic solutions on endothelial integrity and oxidative stress in cardiovascular surgery. Methods: In this randomized prospective study, after ethics approval and informed consent, 60 surgical patients were included. Patients undergoing coronary bypass surgery were randomized into two groups as warm blood cardioplegia (n = 30) and cold crystalloid cardioplegia (n = 30) following the cross-clamping. Measurements were performed at three time points: before induction of anesthesia (T1), at admission to intensive care unit (ICU) (T2) and at the 24th postoperative hour (T3). Besides biochemical routine hemodynamic monitoring, patients were assessed for the sialic acid (SA), ischemic-modified albumin (IMA), advanced oxide protein products (AOPPs), total thiol (SH), and free hemoglobin (fHb) level. Results: Neither crystalloid nor blood cardioplegia led to significant changes in the AOPPs, T-SH, and SA level (p >0.05). Crystalloid cardioplegia, however, increased IMA level compared to both baseline (p <0.01) and blood cardioplegia group (p <0.05). fHb levels were transiently increased in both groups at the second-time point (p <0.001). fHb level was lower in the crystalloid group compared to that in the other group (p <0.05) at T2. Conclusion: Cardioplegia type creates similar effects on glycocalyx integrity. However, myocardial protection could be provided with warm blood cardioplegia.


Immunogenetics | 2017

A novel pathogenic frameshift variant of CD3E gene in two T-B+ NK+ SCID patients from Turkey

Sinem Firtina; Yuk Yin Ng; Ozden Hatirnaz Ng; Serdar Nepesov; Osman Yesilbas; Meltem Kilercik; Nihan Burtecene; Suzan Cinar; Yildiz Camcioglu; Ugur Ozbek; Muge Sayitoglu

Severe combined immunodeficiency (SCID) is the most severe form of primary immunodeficiency, which is characterized by the dysfunction and/or absence of T lymphocytes. Early diagnosis of SCID is crucial for overall survival, and if it remains untreated, SCID is often fatal. Next-generation sequencing (NGS) has become a rapid, high-throughput technology, and has already been proven to be beneficial in medical diagnostics. In this study, a targeted NGS panel was developed to identify the genetic variations of SCID by using SmartChip-TE technology, and a novel pathogenic frameshift variant was found in the CD3E gene. Sanger sequencing has confirmed the segregation of the variant among patients. We found a novel deletion in the CD3E gene (NM000733.3:p.L58Hfs*9) in two T-B+ NK+ patients. The variant was not found in the databases of dbSNP, ExAC, and 1000G. One sibling in family I was homozygous and the rest of the family members were heterozygous for this variant. T cell receptor excision circle (TREC) and kappa-deleting recombination excision circle (KREC) analyses were performed for T and B cell maturation. TRECs were not detected in both patients and the KREC copy numbers were similar to the other family members. In addition, heterozygous family members showed decreased TREC levels when compared with the wild-type sibling, indicating that carrying this variant in one allele does not cause immunodeficiency, but does effect T cell proliferation. Here, we report a novel pathogenic frameshift variant in CD3E gene by using targeted NGS panel.

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