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Dive into the research topics where Sema Karakus is active.

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Featured researches published by Sema Karakus.


European Journal of Haematology | 2011

Addition of thalidomide to oral melphalan/prednisone in patients with multiple myeloma not eligible for transplantation: results of a randomized trial from the Turkish Myeloma Study Group.

Meral Beksac; Rauf Haznedar; Tulin Firatli-Tuglular; Hakan Ozdogu; Ismet Aydogdu; Nahide Konuk; Gülsan Türköz Sucak; Isik Kaygusuz; Sema Karakus; Emin Kaya; Ridvan Ali; Zafer Gulbas; Gülsüm Özet; Hakan Goker; Levent Undar

The combination of melphalan–prednisone–thalidomide (MPT) has been investigated in several clinical studies that differed significantly with regard to patient characteristics and treatment schedules. This prospective trial differs from previous melphalan–prednisone (MP) vs. MPT trials by treatment dosing, duration, routine anticoagulation, and permission for a crossover. Newly diagnosed patients with multiple myeloma (MM) (n = 122) aged greater than 55 yr, not eligible for transplantation were randomized to receive 8 cycles of M (9 mg/m2/d) and P (60 mg/m2/d) for 4 d every 6 wk (n = 62) or MP and thalidomide (100 mg/d) continuously (n = 60). Primary endpoint was treatment response and toxicities following 4 and 8 cycles of therapy. Secondary endpoints were disease‐free (DFS) and overall survival (OS). Overall, MPT‐treated patients were younger (median 69 yr vs. 72 yr; P = 0.016) and had a higher incidence of renal impairment (RI, 19% vs. 7%, respectively; P = 0.057). After 4 cycles of treatment (n = 115), there were more partial responses or better in the MPT arm than in the MP arm (57.9% vs. 37.5%; P = 0.030). However, DFS and OS were not significantly different between the arms after a median of 23 months follow‐up (median OS 26.0 vs. 28.0 months, P = 0.655; DFS 21.0 vs. 14.0 months, P = 0.342, respectively). Crossover to MPT was required in 11 patients, 57% of whom responded to treatment. A higher rate of grade 3–4 infections was observed in the MPT arm compared with the MP arm (22.4% vs. 7.0%; P = 0.033). However, none of these infections were associated with febrile neutropenia. Death within the first 3 months was observed more frequently in the MP arm (n = 8, 14.0%) than in the MPT arm (n = 2, 3.4%; P = 0.053). Long‐term discontinuation and dose reduction rates were also analyzed (MPT: 15.5% vs. MP: 5.3%; P = 0.072). Although patients treated with MPT were relatively younger and had more frequent RI, better responses and less early mortality were observed in all age groups despite more frequent discontinuation. This study is registered at http://www.clinicaltrials.gov as #NCT00934154.


Clinical and Experimental Medicine | 2005

Conventional and molecular cytogenetic findings of myelodysplastic syndrome patients.

Zerrin Yilmaz; Feride Iffet Sahin; Ebru Kizilkilic; Sema Karakus; Can Boga; Hakan Ozdogu

AbstractMyelodysplastic syndrome (MDS) involves myeloid cells of the bone marrow, which is important in progressive bone marrow insufficiency. Of all MDS patients, 40%–50% have at least one chromosomal rearrangement. Loss of specific chromosomal regions like 5q– and 7q– are usually the secondary cytogenetic abnormalities associated with MDS. In order to detect chromosome abnormalities associated with MDS, bone marrow samples from 26 patients diagnosed as MDS were obtained prior to chemotherapy. Both conventional cytogenetic analyses and fluorescence in situ hybridisation (FISH) methods were performed and locus–specific probes for 5q and 7q were used. Results obtained were compared. Twenty–one patients had normal karyotypes and four patients had abnormal karyotypes, while in one patient we could not obtain metaphases from cultures. Three patients with normal karyotypes revealed del (5q), two patients had del (7q) and one patient had monosomy (7). A total of 10 of 26 patients had chromosome changes visualised by either conventional or molecular cytogenetics (~38.5%). Our results show that both methods are important in diagnosis and follow up of MDS patients. When used together, conventional cytogenetics and FISH detect clinically significant chromosome abnormalities in MDS patients.


Blood Coagulation & Fibrinolysis | 2002

Rational use of the PFA-100 device for screening of platelet function disorders and von Willebrand disease.

Yahya Buyukasik; Sema Karakus; Hakan Göker; Ibrahim C. Haznedaroglu; Düzgün Özatli; Nilgun Sayinalp; Ozcebe Oi; Semra Dündar; Serafettin Kirazli

Two hundred and five patients referred for evaluation of platelet functions and 126 healthy controls were tested with the PFA-100 instrument. A cut-off value of 150 s for collagen/epinephrine (CEPI) closure time (CT) produced most acceptable sensitivity (90%), specificity (85.2%), and positive (82.6%) and negative (91.6%) predictivity values for screening of platelet function disorders and von Willebrand disease (vWD). All patients with vWD and Glanzmann thrombasthenia could be detected by PFA-100. Both CEPI and collagen/adenosine diphosphate (CADP) CTs were elevated in all of these cases. Sensitivity of the device was 81.6% for patients with platelet secretion defects. CADP CT was normal in 63.9% of the patients in this subgroup. Specificity (47%) and positive predictivity (57%) of the instrument were diminished in patients with low hemoglobin concentrations. Depending on the results, an algorithm was developed for screening of platelet function disorders and vWD with PFA-100.


Rheumatology International | 2002

Unchanged global fibrinolytic capacity despite increased factor VIIa activity in Behçet's disease: evidence of a prethrombotic state

Düzgün Özatli; Nilgun Sayinalp; Yahya Buyukasik; Sema Karakus; Ibrahim C. Haznedaroglu; Şerafettin Kirazli; Osman Özcebe; Semra Dündar

Abstract.The aim of this study was to evaluate coagulation and fibrinolytic systems in Behçets disease (BD). Accordingly, various parameters of the coagulation and fibrinolytic systems were investigated in 39 patients with BD and 31 age- and sex-matched healthy volunteers as the control group. Seven of these patients with BD had histories of thrombotic complication. Three were found to have decreased protein S activity, and one patient had diminished protein C activity. Each of those patients had experienced a thromboembolic event. Activated protein C resistance was present in two patients, one of whom had had a thromboembolic episode. Activated FVII (FVIIa), fibrinogen, and cholesterol levels were significantly higher in patients with BD than in the control group. In the patient group, plasma FVIIa level was inversely correlated with age. Plasma global fibrinolytic capacity (GFC) did not differ between the patients and control group. No statistically significant difference was found in the GFC and FVIIa levels between patients with and without histories of thrombosis. Although the coagulation system was activated in vivo in patients with BD, there was no reactive activation in the fibrinolytic system to counteract the activated coagulation system. These findings suggest a relative hypofibrinolytic state in BD.


Hematology | 2009

Fluorescent in situ hybridization studies in multiple myeloma.

Ozge Ozalp Yuregir; Feride Iffet Sahin; Zerrin Yilmaz; Ebru Kizilkilic; Sema Karakus; Hakan Ozdogu

Abstract Conventional cytogenetic analysis and fluorescence in situ hybridization (FISH) results of bone marrow samples of 36 multiple myeloma (MM) patients at the time of diagnosis have been evaluated. Three probes for chromosome 13q (RB1, D13S319, D13S25), one for 14q32 (IgH) and one for 17p13 (p53) have been used for hybridization with fixed cells. Twenty patients (55·5%) had normal karyotypes, whereas eight (22·2%) had numerical or structural chromosomal abnormalities. We did not find metaphases for chromosome analysis in eight (22·2%) patients. Fluorescence in situ hybridization analyses revealed at least one or more abnormal results in 25 (69·5%) cases, whereas 11(30·5%) cases had no abnormal findings. 14q32 rearrangement was the most common finding in FISH analyses and has been detected in 21 cases (58·3%). 13q deletion and 17p deletion have been detected in 11 (30·5%) and 5 (13·9%) cases, respectively. Fluorescence in situ hybridization studies including 14q32 and 17p13 chromosome regions may yield quite significant results during clinical follow-up of MM.


Acta Histochemica | 2003

Syndecan-1/CD138 expression in normal myeloid, acute lymphoblastic and myeloblastic leukemia cells.

Aysel Seftalioglu; Sema Karakus

Stabilization of cell surface antigens and preservation of ultrastructural integrity are important aspects of immunoelectron microscopical studies. In the present study, 4 anti-syndecan-1/CD138 (B-B2, B-B4, MI15, 1D4) monoclonal antibodies (mAbs) were applied in combination with periodatelysine-paraformaldehyde (PLP) fixation and indirect pre-embedding peroxidase electron microscopical immunocytochemistry to analyse the localization and function of these molecules in normal myeloid cells, acute lymphoblastic leukemia (ALL) cells and acute myeloblastic leukemia (AML) cells. One case of normal human bone marrow, 3 cases of untreated AML and 2 cases of untreated ALL were studied. Samples were immediately fixed for 4 h in freshly-prepared PLP fixative in 0.037 mol/L phosphate buffer, pH 7.4, containing 10 mmol/L sodium metaperiodate, 75 mmol/L lysine, and 2% paraformaldehyde. Expression of syndecan-1 was found at the plasma membrane of all cell types. Staining intensity at the membrane of AML cells was stronger than that on the membrane of normal myeloid and ALL cells. We conclude that anti-syndecan-1/CD138 mAbs in combination with the method described here are a suitable tool for detection of cell surface syndecan molecules in cells originating from progenitor cells that can differentiate in both myeloid and lymphoid cells.


Hematology | 2000

Anemias in Chronic Liver Diseases

Düzgün Özatli; Köksal A; Ibrahim C. Haznedaroglu; Halis Şimşek; Sema Karakus; Yahya Buyukasik; Ali Kosar; Osman Özcebe; Semra Dündar

Anemia is a frequently observed manifestation during the clinical course of chronic liver disease. In this study, we retrospectively reviewed the hospital files of 500 chronic liver disease patients and assessed the frequency, etiology and morphology of anemia in 50 patients who fulfilled the criteria to be included in the study. The mean age of the patients was 48 ± 16 years and male/female ratio was 1.4/1. The mean hemoglobin value was 9.54 ± 2.03 g/dl. The mean MCV was 82.9 ± 10.52 fl. Iron deficiency anemia, defined as absent bone marrow iron stores, was the most common anemia present in 50% of patients. Classical laboratory criteria used in the diagnosis of iron deficiency anemia (MCV < 80 fl, ferritin < 10 ng/ml) could not be applicable to all of the patients with iron deficiency anemia and hepatic disorders. Hemolytic anemia due to hypersplenism was the second most common anemia (24%) followed by anemias, namely anemia due to gastrointestinal hemorrhage (22%), anemia of chronic disease (8%), β-thalassemia major (8%), folate deficiency (6%), vitamin B12 deficiency (4%), macrocytic anemia (2%), aplastic anemia (2%) and immune hemolytic anemia (2%). Twenty-eight percent of the patients had more than a single cause of anemia. Morphologically, microcytic anemia was the most common seen in 46% of the patients followed by normocytic (42%) and macrocytic anemia (12%). As patients do not always present with classical laboratory findings and may have more than a cause of anemia, a complex diagnostic approach should be considered in anemic patients with hepatic disorders.


Acta Oncologica | 2003

Syndecan-1 (CD138) Expression in Acute Myeloblastic Leukemia Cells

Aysel Seftalioglu; Sema Karakus; Semra Dündar; Belgin Can; Esra Erdemli; M. Kemal Irmak; Emin Oztas; Cem Korkmaz; Fatih Yazar; Ilkin Cavusoglu

Syndecan-1 (CD138), an important transmembrane heparan sulfate proteoglycan is expressed in distinct stages of cell differentiation. Although its expression in acute lymphoblastic leukemia (ALL) cells is well known; its function or presence in acute myeloblastic leukemia (AML) cells is still largely unknown. The expression of syndecan-1 was studied in bone marrow biopsies of three patients with AML using electron microscopic immunocytochemistry. Positive expression of syndecan-1 was found in AML cells. These results suggest that syndecan-1 expression is not only a characteristic phenotypic marker for ALL, but is also expressed in AML cells.


Hematology | 2002

Circulating Thrombopoietin in Clonal Versus Reactive Thrombocytosis

Sema Karakus; Osman Özcebe; Ibrahim C. Haznedaroglu; Hakan Goker; Düzgün Özatli; Ali Kosar; Yahya Buyukasik; Derun Ertuğrul; Nilgun Sayinalp; Şerafettin Kirazli; Semra Dündar

Introduction: The aim of this study is to assess circulating thrombopoietin concentrations in patients with both clonal and reactive thrombocytosis (RT), which are two distinct categories of extreme platelet production circumstances. Investigation of the thrombopoietin levels in clonal versus reactive thrombocytosis may help us to understand the interactions of this key regulatory cytokine and the conditions in which abnormally increased platelet formation exist. Materials and methods: Thrombopoietin levels were measured in patients with platelet counts greater than 500 × 103 μl−1 The study population consisted of 21 patients with RT (13 with iron deficiency anemia, and 8 with rheumatoid arthritis), 24 patients with clonal thrombocytosis (six with essential thrombocytosis, three with myelofibrosis, eight with chronic myelogenous leukemia, and seven with polycythemia vera (PV)) and 16 healthy subjects were used as controls. Results: The median plasma thrombopoietin concentration was 100.5 pg ml−1 in patients with RT, 467pg ml−1 in patients with clonal thrombocytosis and 62.65pgml−1 in the control group. The thrombopoietin concentration was found to be higher in the patients with primary thrombocytosis when compared to the control group (p = 0.001), as well as in patients with RT (p = 0.002). However, there was no statistically significant difference between the patients with RT and the control group (p = 0.14). There was no correlation between thrombopoietin levels and the platelet counts in patients with clonal thrombocytosis, including essential thrombo- cythemia (ET). Conclusion: Increased levels of thrombopoietin were found in patients with clonal thrombocytosis versus patients with RT and control subjects as well. Defective clearance of thrombopoietin by megakaryocytes and platelets due to a reduced number of thrombopoietin receptors may be the causative mechanism behind this. These results indicate that plasma thrombopoietin levels may be helpful in distinguishing between clonal and reactive thrombocytosis.


Surgery Today | 2010

Spontaneous spleen rupture and rectus sheath hematoma in a patient with Klippel-Trenaunay syndrome: Report of a case

Feza Karakayali; Ceyla Basaran; Ebru H. Ayvazoglu Soy; Sema Karakus; Hakan Yabanoglu; Gokhan Moray; Mehmet Haberal

We report a case of Klippel-Trenaunay syndrome (KTS) with serious morbidity caused by the rupture of hemangiomas of the spleen and inferior epigastric artery (IEA). A 40-year-old woman, who had suffered from edema and varicose veins in her left leg and toes since birth, underwent emergency laparotomy and splenectomy for a spontaneous splenic rupture. Pathological examination revealed hemangiomatosis of the spleen. She presented again 40 days later with a rectus muscle hematoma, which computed tomography revealed to be actively bleeding. Arteriography confirmed a bleeding IEA, which was then embolized. Hematological investigation revealed a heterozygous form of factor VIII and fibrinogen deficiency. The patient recovered well and was asymptomatic at her 1-year follow-up. We report this case to reinforce that investigations for KTS should involve all organ systems, and include detailed hematologic tests. By defining coagulation and vascular abnormalities, life-threatening bleeding episodes may be prevented.

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