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Dive into the research topics where Aysegul Sumer is active.

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Featured researches published by Aysegul Sumer.


Academic Emergency Medicine | 2013

The Value of Signal Peptide-CUB-EGF Domain-containing Protein 1 and Oxidative Stress Parameters in the Diagnosis of Acute Mesenteric Ischemia

Suha Turkmen; Seda Mentese; Ahmet Mentese; Aysegul Sumer; Kutay Sağlam; Esin Yulug; Suleyman Turedi; Abdulkadir Gunduz

OBJECTIVES This study investigated the diagnostic value of signal peptide-CUB-EGF domain-containing protein 1 (SCUBE-1) and other oxidative stress parameters in the early diagnosis of acute mesenteric ischemia, which has high mortality and morbidity if not identified and treated in the early period. METHODS Thirty-six female Sprague-Dawley rats were used in this randomized, controlled study. Rats were divided into six groups: three control groups (Groups I, III, and V) and three ischemia groups (Groups II, IV, and VI). In the control groups, blood and tissue specimens were sampled at 30 minutes (Group I), 2 hours (Group III), and 6 hours (Group V), following a simple laparotomy. In the ischemia groups, the superior mesenteric artery (SMA) was ligated following laparotomy, and blood and tissue samples were sampled at 30 minutes (Group II), 2 hours (Group IV), and 6 hours (Group VI). RESULTS When comparing the ischemia and control groups, the differences in SCUBE-1, malondialdehyde (MDA), and total antioxidant status (TAS) levels in the 30-minute period were not significant (p > 0.05); at 2 hours, SCUBE-1 levels rose rapidly, and although the desired level of significance could not be obtained with Bonferroni correction, the level was significantly higher compared to the control group at the same time interval (for SCUBE-1, Group III vs. Group IV, p = 0.006). In these periods (30 minutes and 2 hours), only total oxidative status (TOS) and oxidative stress index (OSI) values were significantly higher in the ischemia group compared to the control group (for both, p = 0.004). A pronounced rise in SCUBE-1 levels was determined with 6-hour ischemia (for SCUBE-1, Group V vs. Group VI, p = 0.004). The changes in MDA, TAS, TOS, and OSI levels were not significant (p = 0.025, p = 0.321, p = 0.006, and p = 0.037, respectively). CONCLUSIONS SCUBE-1 levels have the potential to be used as a marker of early period injury in acute mesenteric ischemia, although it is impossible to state explicitly that they can be used for early diagnosis. The same can be said for plasma MDA and TAS levels. The authors believe that TOS and OSI levels, however, can be used in early diagnosis and as an injury marker. Moreover, OSI also exhibits a medium-strong correlation with histopathologic injury.


Cancer Biomarkers | 2012

Is SCUBE 1 a new biomarker for gastric cancer

Ahmet Mentese; Evren Fidan; Aysegul Sumer; Suleyman Caner Karahan; Mehmet Sonmez; Diler Us Altay; Halil Kavgaci; Ahmet Alver

PURPOSES This study was intended to determine the diagnostic significance of signal peptide-CUB-EGF domain-containing protein 1 (SCUBE 1) levels in gastric cancer. METHODS This retrospective study was conducted with patients with gastric cancer. SCUBE 1 titers of plasma in patients with gastric cancer were determined using an enzyme-linked immunosorbent assay (ELISA). RESULTS SCUBE 1 titers of gastric cancer patients were significantly higher compared with the control group (P=0.0001). At a SCUBE 1 cut-off point of 43 ng/mL, sensitivity was 67%, specificity 91%, positive predictive values (PPV) 92% and negative predictive values(NPV) 63%. SCUBE 1 levels of patients with methastase were not different from patients without methastase (P> 0.05). DICUSSIONS: SCUBE 1 levels in patients with gastric cancer were found higher compared to healthy subjects.


International Journal of Infectious Diseases | 2013

The diagnostic and prognostic significance of SCUBE1 levels in Crimean-Congo hemorrhagic fever

Ahmet Mentese; Gürdal Yilmaz; Aysegul Sumer; Mustafa Arslan; Suleyman Caner Karahan; Iftihar Koksal

BACKGROUND The new biochemical marker, signal peptide-CUB-EGF domain-containing protein 1 (SCUBE1), is secreted and cell surface glycoprotein expressed during early embryogenesis. The protein is found in platelet and endothelial cells. Crimean-Congo hemorrhagic fever (CCHF), which is caused by a tick-borne virus belonging to the Bunyaviridae family, may present with a mild clinical course or may exhibit a severe profile with potentially fatal hemorrhaging. The aim of this study was to determine the diagnostic and prognostic significance of SCUBE1 levels in CCHF. METHODS This study was conducted with patients with CCHF. SCUBE1 levels in patients with CCHF were determined using an ELISA. RESULTS SCUBE1 titers of CCHF patients were significantly higher compared to those of the control group (p=0.0001). SCUBE1 levels of patients with hemorrhage were significantly higher than those of patients without hemorrhage (p=0.0001). SCUBE1 values of patients who died were significantly higher than those of the survivors (p=0.012). CONCLUSIONS SCUBE1 levels are a new biomarker that can be used in the differential diagnosis and monitoring of patients hospitalized with suspected CCHF. These levels are also significant as potential predictors of mortality.


International Journal of Infectious Diseases | 2013

The significance of serum urokinase plasminogen activation receptor (suPAR) in the diagnosis and follow-up of febrile neutropenic patients with hematologic malignancies

Selçuk Kaya; Iftihar Koksal; Ahmet Mentese; Mehmet Sonmez; Aysegul Sumer; Seval Sönmez Yıldırım; Gürdal Yilmaz

OBJECTIVES The purpose of this study was to investigate serum levels of serum urokinase plasminogen activation receptor (suPAR) during the first week of febrile neutropenia and to demonstrate the significance of this biomarker in the diagnosis and follow-up of febrile neutropenic patients with hematologic malignancies. METHODS The study was performed between January 2011 and January 2012 at Karadeniz Technical University, Turkey. For neutropenic patients with hematologic malignancies, the day before the onset of fever and the first day of the febrile neutropenia attack were taken as days 0 and 1, respectively. Blood samples were obtained from patients with hematologic malignancies on days 0, 1, 3, 5, and 7. Sixty-eight healthy volunteers were enrolled as the control group. suPAR levels were determined using an ELISA kit following the manufacturers protocols. Twenty-six male and 14 female patients with hematologic malignancies, the majority with acute/myeloid/lymphocytic leukemia, aged 19-78 years (mean 46.8 years), were included. Fifty febrile neutropenic attacks were investigated in these patients. RESULTS The mean serum levels of the controls and suPAR 0 were 3.9 ± 1.5 ng/ml and 5.8 ± 2.7 ng/ml, respectively. Serum levels of suPAR rose earlier than levels of C-reactive protein and procalcitonin. Serum suPAR levels increased in patients with hematologic malignancies and were found to represent an important serum biomarker for the early prediction of neutropenic fever. A decrease in serum suPAR levels was found to be correlated with treatment response due to antibiotics in this patient group. There were significant differences in suPAR 1 levels between patients with documented infection and those with fever of unknown origin in favor of the former. When the suPAR 1 results were analyzed using the receiver operating characteristics (ROC) curve method, the optimum diagnostic cut-off point was 5.87 ng/ml, the area underneath the ROC curve (AUC) was 0.81 (95% confidence interval 0.68-0.91), sensitivity was 100%, specificity was 69%, negative predictive value (NPV) was 100%, and positive predictive value (PPV) was 70%. CONCLUSIONS We conclude that suPAR is an important biomarker that can predict infections in the early stage of febrile neutropenia with high sensitivity and NPV for patients with hematologic malignancies. It is also advantageous since it shows the response to treatment with antibiotherapy in the early stage.


Urology | 2015

The Diagnostic Value of Plasma SCUBE1, a Novel Biomarker of Platelet Activation, in Testicular Torsion: A Randomized, Controlled, Experimental Study.

Suleyman Turedi; Ozgur Tatli; Ahmet Alver; Ersagun Karagüzel; Yunus Karaca; Suha Turkmen; Esin Yulug; Aysegul Sumer; Diler Us Altay; Ahmet Mentese

OBJECTIVE To investigate the potential diagnostic value of plasma signal peptide, CUB (complement proteins C1r/C1s, Uegf, Bmp1) domain, epidermal growth factor (EGF)-like 1 (SCUBE1) protein in experimentally induced testicular torsion (TT). MATERIALS AND METHODS In this randomized, controlled, experimental study, 24 mature male Wistar rats were divided into four groups: 2- and 4-hour control (groups I and III, respectively), and 2- and 4-hour torsion (groups II and IV, respectively) groups. Torsion was performed by rotating the left testis 720° clockwise and maintained by fixing the testis. Plasma SCUBE1 levels and histopathological damage scores were compared. RESULTS There was significantly greater histopathological damage in the 4-hour torsion group compared with the other groups. SCUBE1 levels in this group were also higher than those in the other groups, and the difference was significant. There were significant correlations between histopathological scores and SCUBE1 levels. CONCLUSION SCUBE1, a novel marker of platelet activation, is elevated in TT. According to our results, platelet activation may play an important pathological role in tissue injury associated with testicular ischemia. Plasma SCUBE1 measurement may have diagnostic, therapeutic, or prognostic value in TT.


Medical Principles and Practice | 2014

The thrombotic events in polycythemia vera patients may be related to increased oxidative stress.

Ahmet Durmus; Ahmet Mentese; Mustafa Yilmaz; Aysegul Sumer; Ibrahim Akalin; Cevat Topal; Ahmet Alver

Objective: This study was designed to compare the oxidative stress parameters of patients with polycythemia vera (PV) to those of healthy volunteers and to investigate the probable relationship between vascular events and parameters of oxidative status such as total oxidative status (TOS), total antioxidant status, oxidative stress index (OSI) and malondialdehyde (MDA) in PV patients. Material and Methods: Thirty-five PV patients (20 males and 15 females) and 20 healthy volunteers (11 males and 9 females) were enrolled. The oxidative status parameters of the patients were measured by spectrophotometric analyses at the time of diagnosis and at 6 months after treatment which consisted of phlebotomy and 100 mg/day acetyl salicylic acid with or without hydroxyurea for the high- and low-risk disease group, respectively. These parameters were compared both to healthy controls and to each other, in order to obtain the values before and after treatment. In addition, during diagnosis, the oxidative status parameters of patients with PV and a history of a vascular event were compared with those of patients with no history of a vascular event. Results: The TOS, OSI and MDA values were significantly higher in the patients than in the control group at the time of diagnosis. At 6 months after phlebotomy and 100 mg/day acetyl salicylic acid therapy, the TOS, OSI and MDA values were significantly lower in the patients when compared to the pretreatment values. The TOS and OSI levels were notably higher in the patients with a vascular-event history than in those without this history. Conclusion: Oxidative stress parameters were increased in PV patients.


Journal of Medical Virology | 2013

Diagnostic and prognostic value of Ischemia-modified albumin in patients with Crimean-Congo hemorrhagic fever.

Ahmet Mentese; Iftihar Koksal; Aysegul Sumer; Mustafa Arslan; S. Caner Karahan; Gürdal Yilmaz

The aim of this study was to determine the diagnostic and prognostic significance of ischemia modified albumin (IMA) levels in patients with Crimean‐Congo hemorrhagic fever (CCHF). This retrospective study was conducted with patients with CCHF. IMA levels in patients with CCHF were determined using the rapid colorimetric method. IMA levels of CCHF patients were significantly higher compared with the control group (P = 0.0001). At an IMA cut‐off point of 0.555 ABSU (absorbance units), sensitivity was 65.1%, specificity 82.5%, positive predictive values (PPV) 82.5%, and negative predictive values (NPV) 65.1%. IMA levels of patients with hemorrhage were significantly higher compared with patients without hemorrhage (P = 0.005). IMA has been validated as both a new and sensitive ischemia and oxidative stress biomarker. In addition to its diagnostic significance, IMA investigated in CCHF patients at time of arrival may be an important marker with its prognostic role in determining in the early stage whether the disease will follow a hemorrhagic course. J. Med. Virol. 85:684–688, 2013.


Ocular Immunology and Inflammation | 2014

Serum Anti-carbonic Anhydrase Antibodies and Oxidant–Antioxidant Balance in Patients with Acute Anterior Uveitis

Adem Türk; Murat Aykut; Nurettin Akyol; Mehmet Kola; Ahmet Mentese; Aysegul Sumer; Ahmet Alver; Hidayet Erdöl

Abstract Purpose: To study the existence of anti-carbonic anhydrase antibodies (anti-CA-I&II) in acute anterior uveitis (AAU) patients and to analyze the relationship between the levels of these antibodies and the total antioxidant capacity (TAC), total oxidant capacity (TOC), oxidative stress index (OSI), and malondialdehyde (MDA) level. Methods: Forty-five AAU cases and 43 healthy controls were enrolled in this prospective study. Results: The average anti-CA I and II antibody levels were 0.433 ± 0.306 and 0.358 ± 0.261 IU/mL, respectively, in the AAU group and 0.275 ± 0.147 and 0.268 ± 0.108 IU/mL, respectively, in the control group (p = 0.004 and p = 0.036, respectively). In addition, it was found that the TOC, OSI, and MDA levels in the AAU subjects were statistically significantly higher than those of the control subjects. Conclusions: These results suggest that autoimmune responses against CA I and CA II and an altered serum oxidant-antioxidant balance may be involved in the pathogenesis of AAU.


Central European Journal of Immunology | 2017

Detection of autoantibodies against carbonic anhydrase I and II in the plasma of patients with gastric cancer

Ahmet Mentese; Evren Fidan; Ahmet Alver; Selim Demir; Serap Ozer Yaman; Aysegul Sumer; Sami Fidan; Halil Kavgaci; Ibrahim Turan

Cancer is the second leading cause of death and gastric cancer is the fourth most common cancer type worldwide. Investigation of autoantibodies in cancer patients has been a popular research area in recent years. The aim of the current study was to investigate carbonic anhydrase I and II (CA I and II) autoantibodies in the plasma of subjects with gastric cancer based on the information and considerations of autoimmune relation of gastric cancer. Anti-CA I and II antibody levels were investigated by ELISA in plasma samples of fifty two patients with gastric cancer and thirty five healthy peers. Anti-CA I and II antibody titers of the gastric cancer group were significantly higher compared with the control group (p = 0.004, p = 0.0001, respectively). Plasma anti-CA I levels of the metastatic group were lower than the non-metastatic group and this difference was found statistically significant (p < 0.05), but there was no statistical difference between plasma anti-CA II levels of the groups. CA I and II autoantibody titers in patients with gastric cancer were found higher compared to healthy subjects and the results suggest that these autoantibodies may be involved in the pathogenesis of gastric cancer.


Cancer Biomarkers | 2015

The indicator of hypoxia in acute leukemia: Ischemia-modified albumin.

Nergiz Erkut; Ahmet Mentese; Hasan Mucait Ozbas; Aysegul Sumer; Asım Örem; Murat Topbas; Mehmet Sonmez

BACKGROUND Hypoxia plays an important role in the development and progression of hematologic malignancies. OBJECTIVE This study was intended to investigate the effectiveness of ischemia-modified albumin (IMA) for demonstrating hypoxia in patients with acute leukemia. METHODS Blood specimens were collected from 132 subjects (44 acute leukemia patients, 40 iron deficiency anemia (IDA) patients and 48 healthy controls). Serum levels of IMA and malondialdehyde (MDA) were analyzed using conventional methods. RESULTS Serum levels of IMA were higher in patients with acute leukemia than in those with IDA and healthy controls (acute leukemia patients; 0.69 ± 0.14 ABSUs, IDA patients; 0.61 ± 0.09 ABSUs, controls; 0.50 ± 0.09 ABSUs, respectively). There was a negative correlation between serum IMA levels and hemoglobin (Hb) values (r = - 0.312) and between serum IMA levels and hematocrit (Hct) values, (r = - 0.305) in patients with acute leukemia. Serum levels of MDA were higher in patients with acute leukemia than in those with IDA. But there was no difference in patients with acute leukemia and IDA compared to healthy controls (acute leukemia patients; 2.23 ± 1.82 nmol/mL, IDA patients; 1.36 ± 0.94 nmol/mL, healthy controls; 1.79 ± 0.78 nmol/mL, respectively). CONCLUSIONS IMA can be effective for demonstrating hypoxia in patients with acute leukemia.

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Ahmet Mentese

Karadeniz Technical University

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Ahmet Alver

Karadeniz Technical University

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Mehmet Sonmez

Karadeniz Technical University

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Suleyman Caner Karahan

Karadeniz Technical University

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Asım Örem

Karadeniz Technical University

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Diler Us Altay

Karadeniz Technical University

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Nergiz Erkut

Karadeniz Technical University

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Selim Demir

Karadeniz Technical University

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Suha Turkmen

Karadeniz Technical University

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Suleyman Turedi

Karadeniz Technical University

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