Rauf Haznedar
Gazi University
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Featured researches published by Rauf Haznedar.
Blood | 2011
Peter Fayers; Antonio Palumbo; Cyrille Hulin; Anders Waage; Pierre W. Wijermans; Meral Beksac; Sara Bringhen; Jean Yves Mary; Peter Gimsing; Fabian Termorshuizen; Rauf Haznedar; Tommaso Caravita; Philippe Moreau; Ingemar Turesson; Pellegrino Musto; Lotfi Benboubker; Martijn R. Schaafsma; Pieter Sonneveld; Thierry Facon
The role of thalidomide for previously untreated elderly patients with multiple myeloma remains unclear. Six randomized controlled trials, launched in or after 2000, compared melphalan and prednisone alone (MP) and with thalidomide (MPT). The effect on overall survival (OS) varied across trials. We carried out a meta-analysis of the 1685 individual patients in these trials. The primary endpoint was OS, and progression-free survival (PFS) and 1-year response rates were secondary endpoints. There was a highly significant benefit to OS from adding thalidomide to MP (hazard ratio = 0.83; 95% confidence interval 0.73-0.94, P = .004), representing increased median OS time of 6.6 months, from 32.7 months (MP) to 39.3 months (MPT). The thalidomide regimen was also associated with superior PFS (hazard ratio = 0.68, 95% confidence interval 0.61-0.76, P < .0001) and better 1-year response rates (partial response or better was 59% on MPT and 37% on MP). Although the trials differed in terms of patient baseline characteristics and thalidomide regimens, there was no evidence that treatment affected OS differently according to levels of the prognostic factors. We conclude that thalidomide added to MP improves OS and PFS in previously untreated elderly patients with multiple myeloma, extending the median survival time by on average 20%.
European Journal of Haematology | 2011
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.
British Journal of Haematology | 2002
Taner Demirer; Meltem Ayli; Muhit Ozcan; Nazan Günel; Rauf Haznedar; Mehmet Daglı; Turgay Fen; Yasemin Genç; Suleyman Dincer; Onder Arslan; Gunhan Gurman; S. Demirer; Gülsüm Özet; Akin Uysal; Nahide Konuk; Osman Ilhan; Haluk Koç; Hamdi Akan
Summary. To date, no randomized study has compared different doses of recombinant human granulocyte colony‐stimulating factor (rhG‐CSF) following submyeloablative mobilization chemotherapy. Therefore, we evaluated the effect of different doses of rhG‐CSF following mobilization chemotherapy on yields of CD34+ peripheral blood stem cells (PBSC). Fifty patients were randomized to receive 8 (n = 25) versus 16 µg/kg/d (n = 25) of rhG‐CSF following mobilization chemotherapy. The median number of CD34+ cells collected after 8 µg/kg/d of rhG‐CSF was 2·36 × 106/kg (range, 0·21–7·80), compared with 7·99 (2·76–14·89) after 16 µg/kg/d (P < 0·001). Twenty out of 25 (80%) patients in the low‐dose and 23 out of 25 (92%) in the high‐dose rhG‐CSF arm underwent high‐dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT). Median days to white blood cell engraftment in patients mobilized with 8 µg/kg and 16 µg/kg of rhG‐CSF were 12 (10–20) and 9 (8–11) respectively (P < 0·001). There was no difference between the two groups regarding the other parameters of peritransplant morbidity: days to platelet engraftment (P = 0·10), number of red blood cell (P = 0·56) and platelet transfusions (P = 0·22), days of total parenteral nutrition requirement (P = 0·84), fever (P = 0·93) and antibiotics (P = 0·77), and number of different antibiotics used (P = 0·58). These data showed that higher doses of rhG‐CSF following submyeloablative mobilization chemotherapy were associated with a clear dose–response effect based on the collected cell yields. Based on the parameters of peritransplant morbidity, 8 µg/kg/d was as effective as 16 µg/kg/d except for a rapid neutrophil engraftment in the high‐dose arm. Therefore, in routine clinical practice, despite some advantage in the use of higher doses of rhG‐CSF, lower doses may be used for PBSC collections following chemotherapy‐based mobilization regimens in this cost‐conscious era.
Leukemia & Lymphoma | 2006
Münci Yađcý; Kadýr Acar; Gülsan Türköz Sucak; Zeynep Aki; Gülendam Bozdayi; Rauf Haznedar
Chemotherapy-induced hepatitis B virus (HBV) reactivation is a serious problem in chronic HBV carriers with hematologic malignancies. In 12 patients with hematologic malignancies, we performed a prospective study to determine the effectiveness of nucleoside analogues in the pre-emptive therapy of chemotherapy-induced HBV reactivation. HBV reactivation occurred in seven patients (58.3%) whereas five of the seven patients (71%) responded to nucleoside analogue therapy. HBV reactivation-related acute liver failure and death was not observed in the present study. All five patients with chronic lymphocytic leukemia (CLL) experienced chemotherapy-induced HBV reactivation regardless of the chemotherapy regimen. Therefore, we suggest that CLL carries a significant risk of chemotherapy-induced HBV reactivation. The pre-emptive therapy of chemotherapy-induced HBV reactivation appears to be safe, based on the results of this pilot study. Pre-emptive therapy enables the definition of high-risk patients who cannot be identified by primary prophylaxis.
Hematology | 2010
Münci Yağcı; Zübeyde Nur Özkurt; Zeynep Arzu Yegin; Zeynep Aki; Gülsan Türköz Sucak; Rauf Haznedar
Abstract Reactivation of hepatitis B virus (HBV) is a frequent complication of chemotherapy (CT) in patients with HBsAg carriers. In this prospective study, we documented CT induced HBV reactivation risk in patients with hematological malignancies. HBV reactivation risk is influenced by baseline viral load. Therefore, we divided our study population into two groups according to HBV-DNA status. HBV-DNA negative patients (n=18) were treated with nucleoside analogues once HBV reactivation was observed. HBV-DNA positive patients (n=12) commenced lamivudine before the initiation of the CT. In HBV-DNA negative patients HBV reactivation was found in 10 patients (55·5%). HBV reactivation was significantly more frequent in chronic lymphocytic leukemia (CLL) patients (P=0·008) and in patients receiving rituximab containing chemotherapy regimens (P=0·06). Eight patients (80·0%) responded to antiviral treatment after HBV reactivation. Two CLL patients experienced a flare-up after the withdrawal of antiviral therapy. In HBV-DNA positive patients, HBV reactivation was observed in four patients (33·3%) during lamivudine treatment and in two patients after lamivudine withdrawal. This study demonstrated the increased risk of CT-induced HBV reactivation in CLL patients, for the first time.
Journal of Endocrinology | 2012
Emin Umit Bagriacik; Melek Yaman; Rauf Haznedar; Gülsan Türköz Sucak; Tuncay Delibasi
Bone marrow-derived mesenchymal stem cells are pluripotent cells that are capable of differentiating into a variety of cell types including neuronal cells, osteoblasts, chondrocytes, myocytes, and adipocytes. Despite recent advances in stem cell biology, neuroendocrine relations, particularly TSH interactions remain elusive. In this study, we investigated expression and biological consequence of TSH receptor (TSHR) interactions in mesenchymal stem cells of cultured human bone marrow. To the best of our knowledge, we demonstrated for the first time that human bone marrow-derived mesenchymal stem cells expressed a functional thyrotropin receptor that was capable of transducing signals through cAMP. We extended this study to explore possible pathways that could be associated directly or indirectly with the TSHR function in mesenchymal stem cells. Expression of 80 genes was studied by real-time PCR array profiles. Our investigation indicated involvements of interactions between TSH and its receptor in novel regulatory pathways, which could be the important mediators of self-renewal, maintenance, development, and differentiation in bone marrow-derived mesenchymal stem cells. TSH enhanced differentiation to the chondrogenic cell lineage; however, further work is required to determine whether osteoblastic differentiation is also promoted. Our results presented in this study have opened an era of regulatory events associated with novel neuroendocrine interactions of hypothalamic-pituitary axis in mesenchymal stem cell biology and differentiation.
British Journal of Haematology | 2002
Taner Demirer; Meltem Ayli; Mehmet Daglı; Rauf Haznedar; Yasemin Genç; Turgay Fen; Suleyman Dincer; Ekrem Ünal; Nazan Günel; Ertugrul Seyrek; Tülay Üstün; Nilufer Ustael; Mustafa Yildiz; Durdu Sertkaya; Gülsüm Özet; Osman Muftuoglu
Summary. This study evaluated of the effect of post‐transplant recombinant human granulocyte colony‐stimulating factor (rhG‐CSF) administration on the parameters of peritransplant morbidity. Three sequential and consecutive cohorts of 20 patients each received either post‐transplant rhG‐CSF at a dose of 5 µg/kg/d i.v. in the morning, starting on d 0, d 5, or no rhG‐CSF. Patients who received rhG‐CSF starting on d 0 and 5 recovered granulocytes more rapidly than those not receiving rhG‐CSF (P < 0·001 for ANC ≥ 0·5 and 1 × 109/l). RhG‐CSF administration was not significantly associated with more rapid platelet engraftment. RhG‐CSF administration starting on d 0 and 5 was significantly associated with a decreased duration of fever (P = 0·002 and 0·001 respectively), antibiotic administration (P < 0·001 and 0·006 respectively) and shorter hospitalization (P < 0·001 and 0·001 respectively) compared with the reference group. There was no difference between the d 0 and d 5 arms regarding the parameters of peritransplant morbidity. In conclusion, rhG‐CSF administration was associated with a faster granulocyte recovery, shorter hospitalization, and shorter period of fever and non‐prophylactic antibiotic administration. This study also showed that starting rhG‐CSF administration on d 5 may be as effective as d 0 on the clinical outcome and may be an economical approach in routine clinical practice in this cost‐conscious era.
Archive | 1999
Alper Cihan; B. Bülent Menteş; Gülsan Türköz Sucak; Ahmet Karamercan; Rauf Haznedar; Zafer Ferahköşe
An unusual case of Fourniers gangrene after hemorrhoidectomy and drug-induced agranulocytosis, as the predisposing condition, is described. The patient had severe granulocytopenia that was attributed to the recent use of dipyrone. Together with hemodynamic resuscitation, broad-spectrum antibiotic and recombinant human granulocyte colony-stimulating factor were started. Wide surgical excision of all the gangrenous tissues, in addition to laparoscopic formation of a defunctioning sigmoid loop colostomy, was performed. The white blood cell count rose steadily and the patient experienced a rapid recovery. We emphasize that radical surgery must be accompanied by pharmacologic interventions for a successful outcome in such cases.
Blood Coagulation & Fibrinolysis | 2006
Gülsan Türköz Sucak; Kadir Acar; Ayhan Sucak; Serafettin Kirazli; Rauf Haznedar
The aim of this study was to compare fibrinolysis in normal pregnancy and pre-eclampsia using individual markers of thrombosis and fibrinolysis with the contribution of a new parameter, global fibrinolytic capacity. Coagulation was determined with thrombin–antithrombin complex and prothrombin fragment 1+2 (F 1+2) and fibrinolysis markers. Tissue plasminogen activator, plasminogen activator inhibitor-1 and global fibrinolytic capacity were determined in 14 normal pregnancies and 29 women with pre-eclampsia. global fibrinolytic capacity was also determined in 14 age-matched healthy women. The Mann–Whitney U test and Pearson correlation test were used for statistical analysis. Thrombin–antithrombin complex, prothrombin fragment 1+2 levels, and global fibrinolytic capacity levels in pre-eclamptic women were significantly higher than in women with normal pregnancies (P < 0.05). Tissue plasminogen activator, plasminogen activator inhibitor-1 levels were also significantly higher in the pre-eclampsia group (P < 0.001 and P < 0.05 respectively). No significant correlation was found between global fibrinolytic capacity and thrombin–antithrombin complex, prothrombin fragment 1+2 levels, tissue plasminogen activator or plasminogen activator inhibitor-1 activity. Our results suggest that both thrombin formation and fibrinolysis are increased in pre-eclampsia compared with normal pregnancy. The increased global fibrinolytic capacity indicates that fibrinolysis remains preserved in pre-eclampsia. We suggest that global fibrinolytic capacity may be a useful parameter for accurately measuring in-vivo fibrinolysis globally, instead of with single parameters which may overlook the complex interactions between coagulation and fibrinolytic systems.
Bone Marrow Transplantation | 2002
Taner Demirer; M Daglı; Osman Ilhan; M Aylı; Rauf Haznedar; T Fen; N Gunel; Y Genc; Mutlu Arat; Muhit Ozcan; Onder Arslan; E Seyrek; S Dincer; T Ustun; N Ustael; Haluk Koç; O Muftuoglu; Hamdi Akan
It is logical to expect that large-volume leukapheresis may be able to collect adequate numbers of PBSC with fewer procedures. To date, there is no agreement on the optimal volume of leukapheresis. Therefore, in this study we compared 8 l volume with 12 l and assessed whether a 50% increase in the blood volume processed would decrease the number of leukaphereses each patient needed to collect ⩾2.5 × 106 CD34+ cells/kg in normal mobilizers. PBSC mobilization was done with cyclophosphamide etoposide followed by rhG-CSF in all patients. Forty patients were randomized to undergo 8 l leukaphereses (n = 20 patients) or 12 l leukaphereses (n = 20). The median numbers of leukaphereses required in order to collect ⩾2.5 × 106 CD34+ cells/kg in patients processed with 8 l and 12 l were 1 (range 1–5) and 1 (1–4), respectively (P = 0.50). The median number of total nucleated cells (TNC) collected per patient was greater for the 12 l group (7.47 × 108/kg vs 3.90 × 108/kg, P < 0.001), as was the median number of total mononuclear cells (TMNC) (4.26 × 108/kg vs 2.16 × 108/kg, P < 0.001), whereas there was no difference between the two groups for the median number of CD34+cells collected per patient (8.94 × 106/kg vs 8.60 × 106/kg, P = 0.85). The TNCs and TMNCs collected per leukapheresis were again greater for the 12 l group (3.64 × 108/kg vs 1.91 × 108/kg, P = 0.001 and 2.17 × 108/kg vs 0.88 × 108/kg, P < 0.001), whereas there was no difference between the two groups for the median number of CD34+ cells collected per leukapheresis (3.98 × 106/kg vs 3.26 × 106/kg, P = 0.90). This study showed that there is no difference between 8 l and 12 l volumes in regard to collected CD34+ cells/kg and also the use of a 12 l leukapheresis volume did not decrease the number of leukaphereses performed compared with a 8 l leukapheresis volume. In fact, the use of the larger leukapheresis volume had the disadvantage of adding 60 min to the time the patient was on the machine.