G.H. Özsan

Dokuz Eylul University, Ismir, İzmir, Turkey

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Publications (14)6.83 Total impact

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    ABSTRACT: Therapy-related leukemias are 10-20% of all acute leukemia cases. Therapy-related acute lymphoblastic leukemia (ALL) is less frequent than therapy-related acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). In this paper, we present a patient with Ewing's sarcoma (ES) in the soft tissue of his right breast cured by chemotherapy and radiotherapy. He developed Philadelphia negative (Ph(-)) ALL four years following the therapy. (Marmara Medical Journal 2012;25:100-2) Key Words: Ph(-) ALL, Secondary leukemia, Ewing's sarcoma
    No preview · Article · Jan 2012 · Marmara Medical Journal

  • No preview · Article · Jan 2012
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    ABSTRACT: Aim: The precise pathogenetic mechanisms causing thrombotic complications in Behçet's disease (BD) are still not known. To explain the pathogenesis with coagulation induction or a defective fibrinolysis superimposed on endothelial dysfunction, various hemostatic parameters were studied. Thrombin activatable fibrinolysis inhibitor (TAFI), downregulating plasmin generation and fibrinolysis, is a novel risk factor for thrombotic disorders. We studied plasma TAFI levels in BD in comparison with healthy controls. Materials and Methods: Twenty-three patients with BD (mean age: 38.3 ± 10.83, M/F: 5/18) diagnosed according to the criteria of the International Study Group and 20 healthy volunteers (mean age: 38.05 ± 6.29, M/F: 9/11) were enrolled in this study. Patients with liver or renal disease, diabetes mellitus, coronary artery disease, hemophilia, antiphospholipid antibody positivity or using oral contraceptive drugs were excluded from the study. Plasma TAFI levels were determined by using an ELISA test. Results: The mean TAFI antigen levels were 8.40 ± 1.81 μg/ml in BD patients and 7.30 ± 0.64 μg/ml in healthy volunteers. A statistically significant difference was found between TAFI antigen levels of these two groups (P = 0.01). Conclusions: TAFI antigen levels were found to be increased in BD, regardless of thrombotic events. To clarify the exact role of TAFI in thrombotic complications of the disease, future studies including more patients with and without thrombosis are needed.
    No preview · Article · Oct 2007 · Turkish Journal of Medical Sciences
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    ABSTRACT: Fludarabine-containing combinations have additive cell killing against leukemic blasts in vitro. It has also been shown that imatinib mesylate combined with fludarabine or cladribine had an additive effect on CML CFU-GM cells. In this regard, we aimed to investigate the effect of fludarabine-imatinib mesylate combination against CML blastic phase cell lines K562 and Meg-01. XTT test was performed for proliferation and inhibition assay. According to obtained data, five different effective concentrations of each drug in 25 different combinations were tested. Results of the combination studies were analyzed with isobologram. At IC20, imatinib mesylate and fludarabine combination showed synergism and strong synergism in K562 and Meg-01 cells, respectively. At IC50 and IC75, combination indexes (Cl) indicated strong synergism and synergism. Based on our results, the fludarabine- based chemotherapy regimens can be used for those patients with CML blastic phase in combination with imatinib mesylate.
    No preview · Article · Jan 2007
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    ABSTRACT: Myelomatous pleural effusion is extremely rare and cases with cavitary involvement are mostly IgA type myeloma. The effusion is thought as a late manifestation in the natural history of multiple myeloma or an expression of the aggressive behaviour of the disease and a very aggressive treatment is indicated. A case of myelomatous effusion pre-senting as plasma-cell leukemia two years after initial diagnosis of IgG type multiple myeloma is described. ÖZET Plazma Hücreli Lösemi ve Myelomatöz Efüzyon: Olgu Sunumu Myelomatöz efüzyon oldukça nadir görülmekte olup, olgularda kaviter tutulum sıklıkla IgA tip multiple myeloma ile birliktelik göstermektedir. Efüzyon hastalığın doğal sürecinde geç dönemde ortaya çıkan bir bulgu olmakla birlikte, hastalığın saldırgan özelliğinin bir sonucu da olabilir ve agresif bir tedavi yaklaşımı gerektirir. İki yıl önce IgG tip mul-tiple myelom tanısı alarak, myelomatöz plevral efüzyon olarak değerlendirilen ve plazma hücreli lösemi olduğu tesbit edilen olgu literatür eşliğinde sunuldu.
    Preview · Article · Jan 2007 · UHOD - Uluslararasi Hematoloji-Onkoloji Dergisi
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    ABSTRACT: Twenty-four primary gastrointestinal (GI) lymphoma patients diagnosed between September 1998 and April 2004 in hematology department of Dokuz Eylul University Faculty of Medicine were evaluated retrospectively. The female to male ratio of patients was 1/1 with a median age of 64 years. Mean follow-up period was 43.8 months. There were 18 patients (75%) with diffuse large B-cell lymphoma (DLBCL), 6 patients (25%) with extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT/MZBHL). In 83.3% of patients, disease was limited to the stomach. 45.8% of the patients were in stage I-II and 54.2% in stage III-IV. The median overall survival (OS) was 60±20 months. The OS of patients with low and low/intermediate IPI score and OS of patients with stage I-II were higher than OS of patients with high/intermediate IPI score and OS of patients with stage III-IV (120±44.9 months x 34±26.1 months, p=0.01; 120±43.5 months x 25±10 months, p=0.001 respectively). There was no significant differencies between OS of the patients treated with chemotherapy alone and treated with chemotherapy and surgery in both DLBCL and MALT lymphoma group. In conclusion, GI system lymphoma is a heterogenous disease with variety of clinic and demographic features and optimal treatment is not yet established.
    No preview · Article · Jan 2007 · UHOD - Uluslararasi Hematoloji-Onkoloji Dergisi
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    ABSTRACT: Background: The clinical course of patients with inflammatory bowel disease (IBD) is frequently complicated by thromboembolic events and may involve the arterial and venous systems. Although not uniformly documented, several studies document substantial alterations in markers of coagulation and fibrinolysis in patients with IBD. Methods: 45 patients with IBD (31 UC, 14 CD) were included in the study. Age and sex matched 16 volunteers were used as a control group. TAFI antigen was determined using an ELISA kit VisuLiseTM for quantitative measurement. Results: Inflammatory parameters such as white blood cell, platelet levels, erythrocyte sedimentation rate, C-reactive protein were found to be significantly higher in active disease group compared to inactive patients. Coagulation parameters of prothrombin time, activated partial thromboplastin time and d-dimer levels showed no significant difference between active and inactive IBD. Fibrinogen levels were significantly higher in clinically active IBD patients. Plasma TAFI levels demonstrated no significant difference between active and control, inactive and control as well as active and inactive groups. We observed no significant changes in levels of β-TG and PF-4 between active and inactive disease group. Conclusions: We studied plasma TAFI levels in IBD. In conclusion, plasma TAFI levels does not appear to represent to be a marker of activation in IBD in contrast to literature. So further studies covering more patients with different clinic and disease activity status might improve the perspective on this issue.
    No preview · Article · Jan 2006
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    ABSTRACT: It has been shown that imatinib mesylate, a drug used in the treatment of chronic myelogenous leukemia, inhibits the effect of stem cell factor, which has a central role in erythropoiesis. In some polycythemia vera (PV) patients, it has inhibited autonomous erythroid colony growth in vitro and decreased the need for phlebotomy. In this study we have investigated the effect of insulin like growth factor (IGF)-I, stem cell factor (SCF) and erythropoietin (Epo) with interleukin (IL)-3, granulocyte macrophage-colony stimulating factor (GM-CSF) and granulocyte-colony stimulating factor (G-CSF) in the presence of imatinib mesylate on the erythroid progenitors derived from peripheral blood mononuclear cells of three patients with PV and four healthy controls in semisolid medium. Erythroid colony formation from hematopoietic progenitors obtained from healthy controls was observed only in the presence of all cytokines. However, the number of erythroid colonies could not reach that of patients with PV. Inhibition of imatinib mesylate on erythroid colony growth was evident. Hematopoietic progenitors of patients with PV displayed two types of colony formation: the first type was exogenous cytokine-independent and was hypersensitive to current cytokines, and the second displayed hypersensitivity to current exogenous cytokines, but was exogenous cytokine-dependent. For both types, the inhibitory effect of imatinib mesylate was striking in the presence of all cytokines including IL-3, GM-CSF and Epo. There is no direct evidence yet that imatinib mesylate could inhibit the effect of IL-3, G-CSF, GM-CSF, Epo and IGF-I on erythropoiesis. Considering former studies together with results of this study, it can be argued that imatinib mesylate is effective in PV on the intersecting signal transduction mechanisms in which stem cell factor and its receptor may have a part.
    Full-text · Article · Jan 2006
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    ABSTRACT: Thrombocytopenia may be the presenting cytopenia of myelodysplastic syndrome (MDS) and is named as refractory thrombocytopenia (RT) and categorized in the refractory cytopenia with multilineage dysplasia (RCMD) group according to the recent World Health Organization (WHO) classification of the acute leukemias and MDS. Abnormal cytogenetics can be found in 60% to 80% of patients with MDS. Most common cytogenetic abnormalities include monosomy 5, 5q-, monosomy 7, trisomy 8, deletion 20q and loss of X or Y chromosome. Here we report clinical features and outcomes of nine patients with RT. Cytogenetic abnormalities were detected in seven. Among two patients who have a normal karyotype at diagnosis, one of them transformed to acute myeloid leukemia (AML). During a median follow-up of 29 months, two patients died of hemorrhagia and one of AML. The features and prognosis of patients with RT needs to be determined by larger series.
    No preview · Article · Jan 2003 · Turkish Journal of Haematology
  • G.H. Özsan · O. Pişkin · F. Demirkan · H. Ateş · M.A. Özcan · B. Ündar
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    ABSTRACT: Sialic acid is a molecule which is responsible for the net negative surface charge of platelets. We investigated the effect of sialic acid on fresh and cryopreserved platelets. Platelet samples were obtained by platelet apheresis from 8 healthy donors. Platelet suspensions with different sialic acid concentrations (0, 1, 2 and 4 mg/mL) were studied for ADP and ristocetin induced platelet aggregation, basal and ADP induced P-selectin and glycoprotein-Ib/IX expression. Then platelet samples were cryopreserved in 5% DMSO with or without 4 mg/mL sialic acid. After thawing, P-selectin expression was compared with the control group. Six samples were also washed after thawing and P-selectin expression was again compared to unwashed samples. Sialic acid suppressed ADP induced platelet aggregation and P-selectin expression in a dose dependent manner. In cryopreserved samples, P-selectin expression of 4 mg/mL sialic acid containing group was found significantly higher than the control group (p< 0.001). In cryopreserved control group, P-selectin expression of thawed-washed group was significantly higher than thawed-unwashed group (p<0.05). Our results indicate that sialic acid is not a good cryoprotective agent. Washing procedure after thawing to eliminate DMSO causes significant platelet activation.
    No preview · Article · Jan 2001 · Turkish Journal of Haematology
  • F. Demirkan · G.H. Özsan · M.A. Özcan · F. Vural · M. Cabuk · B. Ündar
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    ABSTRACT: Plasma cells are occasionally observed in the peripheral blood of the patients with multiple myeloma. When the number of these circulating cells is significant, the term of plasma cell leukemia is used. We report 5 cases of plasma cell leukemia with poor prognosis with review of the literature.
    No preview · Article · Jan 2001

  • No preview · Article · Apr 1997 · Leukemia Research

  • No preview · Article · Apr 1997 · Leukemia Research
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    ABSTRACT: The effect of interleukin-1 (IL-1) as an autocrine growth factor on the proliferation of the acute mye-loblastic leukemia (AML) blasts was studied. Bone marrow specimens were obtained from nine patients with different subgroups of AML. IL-1 receptor antagonist (IL-1RA) and IL-1 ß neutralizing antibody (IL-1ß NA) alone or in combination were added to the culture mediums of the AML blast cultures for the de-tection of their inhibitory effect on AML blast cell proliferation and colony formation. Average colony num-bers in the IL-RA, IL-ßNA, and IL-IRA plus IL-IßNA included culture flasks, were 63.7 ± 21.5 %, 69.5 ± 19 %, 53.4 ± 23.7 %, respectively, as compared to those of the control (p < 0.01). Inhibition of colony for-mation by IL-IRA plus IL-IßNA was more prominent than by IL-IßNA alone (p < 0.01). No correlation bet-ween the inhibition of AML blast colony formation and FAB AML subgroups was seen. Result: Both IL-1RA or IL-IßNA or in combination induced varying degrees of inhibition on blast co-lony formation. IL-I inhibitory molecules could be considered as an alternative therapy for AML in pati-ents whose blast cells are sensitive to IL-1 inhibition.
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