Özaçmak, Veysel Haktan | Sayan, Hale | Aktunç, Erol

Other | 2009 | Türk Biyokimya Dergisi34 ( 2 ) , pp.82 - 88

Amaç: Adenozin ve adenozin A1 reseptör agonistleri, çeşitli dokuların reperfüzyon harabiyetine karşı önkoşullanma yoluyla koruyucu etkiler göstermektedir. Çalışmanın amacı, sıçan ince bağırsağının reperfüzyon harabiyeti üzerine adenozin A1/A2 reseptör aktivasyonunun etkilerini incelemekti. Yöntemler: Denekler herbiri rastgele sekiz hayvan içeren dört gruba ayrıldı: sham kontrol, iskemi-reperfüzyon kontrol, 5’-N-etilkarboksiamidoadenozin (NECA) (non-selektif A1 /A2 agonisti, 0.1 mg/kg, i.v.) tedavili iskemi-reperfüzyon ve teofilin (non-selektif A1 /A2 antagonisti, 20 mg/kg, i.v.) tedavili iskemi-reperfüzyon. Tedaviler iskemi yapılmad . . .an 5 dk önce uygulandı. Süperiyor mezenter arter 30 dk klempe edildikten sonra reperfüzyon dönemi 180 dk sürdü. Terminal ileum segmentlerinin, KCl, karbakol ve substans P’ye olan kasılma yanıtlarının kaydedilmesinin yanısıra, dokuların miyeloperoksidaz, malondialdehit ve indirgenmiş glutatyon miktarları da ölçüldü. Bulgular: İskemi, nötrofil infiltrasyonu ve lipid peroksidasyonunu ileri düzeyde yükseltirken aynı zamanda indirgenmiş glutatyonu düşürdü. Sham control grubuy- la karşılaştırıldığında, kasılma yanıtları iskemi-reperfüzyon grubunda ciddi düzeyde azaldı. NECA ön tedavisi, doku indirgenmiş glutatyon miktarını ileri derecede düzeltti ve ayrıca iskemi-reperfüzyon sonucu azalmış kasılma yanıtını kısmen iyileştirdi. Teofilin ile ön tedavi ise herhangi koruyucu bir etki göstermedi. Sonuç: Adenozin A1 /A2 reseptör aktivasyonunun, iskemi sonucu gelişen bağırsak kasılma bozukluğuna karşı kısmi koruma sağladığını ve ayrıca bu korumanın, indirgenmiş glutatyon düzeyinin fizyolojik seviyede tutulması yolu ile muhtemelen gerçekleştiğine dair ek kanıt önermekteyiz. Objectives: Adenosine and adenosine A1 receptor agonists exert protective effects against reperfusion injury in different tissues by mediating preconditioning. The aim of the present study was to examine the effects of adenosine A1 /A2 receptor activation on reperfusion-induced small intestinal injury in rat. Methods: Animals were randomized into four groups each including eight as following: sham control, ischemia-reperfusion control, 5’-N-ethylcarboxamidoadenosine (NECA) (non-selective A1 /A2 agonist, 0.1 mg/kg, i.v.)-treated I/R, and theophylline (non-selective A1 /A2 antagonist, 20 mg/kg, i.v.)-treated I/R groups. The treatments were administered 5 min before inducing ischemia in which superior mesenteric artery was clamped for 30 min followed by 180 min of reperfusion pe- riod. Myeloperoxidase, malondialdehyde, and reduced glutathione contents of terminal ileum samples were measured besides recording contractile responses to KCl, carbachol and substance P. Results: Ischemic insult significantly increased neutrophil infiltration and lipid peroxidation while decreasing the reduced glutathione. Contractile responses were seriously reduced in I/R group compared to that of the sham control group. NECA pretreatment alleviated the tissue content of reduced glutathione remarkably besides providing partial amelioration of I/R-reduced contractile response, while theophylline pretreatment had no any protective effect. Conclusion: We offer additional evidence that activation of A1 /A2 adenosine receptors provides partial protection against ischemia-induced intestinal contractile dysfunction possibly through maintaining reduced glutathione content at physiological levels Daha fazlası Daha az

Kolsal, Ebru | Tekin, İshak Özel | Pişkin, Etem | Aydemir, Cumhur | Akyüz, Mehmet | Çabuk, Hasan | Eldes, Nilüfer | Numanoğlu, Kemal Varın

Article | 2009 | Journal of Clinical Apheresis24 ( 1 ) , pp.21 - 24

Tricyclic antidepressant poisoning is one of the most common causes of serious intoxication. Here, we report a 2-year-old girl with severe amitriptyline (70 mg/kg) intoxication. She was in comatose, had generalized tonic clonic seizure, ventricular tachycardia, and wide QRS complexes. Although she did not respond to classical therapies, very good clinical response to plasmapheresis was obtained and she developed no complications. Thus, plasmapheresis may be an effective treatment modality in poisoning with drugs, which bind to plasma proteins with high affinity. © 2009 Wiley-Liss, Inc.

Kalaycı, Özlem A. | Cömert, Füsun B. | Hazer, Baki | Atalay, Turgay | Cavicchi, Kevin A. | Çakmak, Mükerrem

Article | 2010 | Polymer Bulletin65 ( 3 ) , pp.215 - 226

The synthesis, spectroscopic characterization, and antimicrobial efficiency of gold and silver nanoparticles embedded in novel amphiphilic comb-type graft copolymers having good film-forming properties have been described. Amphiphilic comb-type graft copolymers were synthesized by the reaction of chlorinated polypropylene (PP) (Mw = 140,000 Da) with polyethylene glycol (PEG) (Mn = 2,000 Da) at different molar ratios. Metal nanoparticles embedded graft copolymers were prepared by reducing solutions of the salts of silver or gold and the copolymer in tetrahydrofuran. The optical properties of the metal nanoparticle embedded copolymers . . . were determined by using UV-visible spectroscopy. Surface plasmon resonance (SPR) of the gold and silver nanoparticle embedded copolymers in toluene was observed at a maximum wavelength (?max) of 428 and 551 nm in the UV-VIS absorption spectra, respectively. The average particle diameters of the gold and silver nanoparticles were found to be 50 nm from the high resolution scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Amphiphilic polymer films containing silver and gold nanoparticles were found to be highly antimicrobial by virtue of their antiseptic properties to Escherichia coli and Staphylococcus aureus. © Springer-Verlag 2009 Daha fazlası Daha az

Çakmaklı, Birten | Hazer, Baki | Tekin, İshak Özel | Cömert-Beğendik, Füsun

Article | 2005 | Biomacromolecules6 ( 3 ) , pp.1750 - 1758

Peroxidation, epoxidation, and/or perepoxidation reactions of soybean oil under air at room temperature resulted in cross-linked polymeric soybean oil peroxides on the surface along with the waxy soluble part, sPSB, with a molecular weight of 4690, containing up to 2.3 wt % peroxide. This soluble polymeric oil peroxide, sPSB, initiated the free radical polymerization of either methyl methacrylate (MMA) or n-butyl methacrylate (nBMA) to give PSB-g-PMMA and PSB-g-PnBMA graft copolymers. The polymers obtained were characterized by 1H NMR, thermogravimetric analysis, differential scanning calorimetry, and gel permeation chromatography t . . .echniques. Polymeric oil as a plasticizer lowered the glass transition of the PSB-g-PMMA graft copolymers. PSB-g-PMMA and PSB-g-PnBMA graft copolymer film samples were also used in cell culture studies. Fibroblast and macrophage cells were strongly adhered and spread on the copolymer film surfaces, which is important in tissue engineering. Bacterial adhesion on PSB-g-PMMA graft copolymer was also studied. Both Staphylococcus epidermidis and Escherichia coli adhered on the graft copolymer better than on homo-PMMA. Furthermore, the latter adhered much better than the former. © 2005 American Chemical Society Daha fazlası Daha az

Gün, Banu Doğan | Numanoğlu, Gamze | Özdamar, Şükrü Oğuz

Article | 2006 | Acta Obstetricia et Gynecologica Scandinavica85 ( 4 ) , pp.402 - 406

Background. To determine whether adequate trophoblastic migration and maternal placental perfusion occurs in cases of early pregnancy loss, we compared vessels in elective abortion decidua with those in spontaneous abortion decidua. Methods. Elective abortion decidua at 5-11 weeks ( n =40) were compared with spontaneous abortion decidua at 5-12 weeks ( n =25). Also normal late secretory endometrial biopsy specimens ( n =10) were examined. The cross-sections of veins and arteries were counted in 25 elective and 15 spontaneous abortion materials. The number of the veins that contain trophoblastic fragments and the number of the spiral . . . arteries converted by trophoblasts were determined. Statistical significance by Mann-Whitney U and Spearman's correlation test was p Daha fazlası Daha az

Sayan, Hale | Özaçmak, Veysel Haktan | Güven, Aysel | Aktaş, R. Gülhan | Özaçmak, I. Diler

Article | 2006 | Journal of Investigative Surgery19 ( 3 ) , pp.163 - 173

Erythropoietin exerts hematopoietic effects by stimulating proliferation of early erythroid precursors. Nonhematopoietic effects of erythropoietin have also been shown. It may act as a new angiogenic factor in wound healing. This study aimed to investigate the effect of systemic administration of recombinant human erythropoietin on wound healing in mice. Dorsal incisional wounds were performed in mice, which were then divided into two groups; a group treated for 7 days with recombinant human erythropoietin, and a control group. Sacrificing animals on day 7, the wound tissues were collected for analysis of wound breaking strength, ma . . .londialdehyde, a marker of lipid peroxidation, hydroxyproline, an index of reparative collagen deposition, reduced glutathione levels, and for histological evaluation. The immunohistochemical determination of vascular endothelial growth factor (VEGF) which is believed to be the most prevalent angiogenic factor throughout the skin repair process, was also studied. The treatment significantly increased wound breaking strength by decreasing malondialdehyde and increasing hydroxyproline levels on day 7 after wounding. No statistically meaningful change was observed in reduced glutathione content. VEGF was immunostained significantly more on wound tissue of treated animals compared to the control group. Recombinant human erythropoietin treatment may be effective in wound healing due to inhibition of lipid peroxidation, deposition of collagen, and VEGF expression in wound area. Copyright © Taylor & Francis Group, LLC Daha fazlası Daha az

Koca, Rafet | Altinyazar, H. Cevet | Numanoğlu, Gamze | Ünalacak, Murat

Article | 2004 | Journal of Tropical Pediatrics50 ( 3 ) , pp.178 - 179

A 7-year-old boy presented to our clinic with a 1-week history of guttate psoriasis-like lesions after BCG vaccination. Although the patient did not have any history of psoriasis, his father and uncle had a history of psoriasis vulgaris. He was treated successfully with topical corticosteroid. Complete healing was seen after 3 weeks and the patient was still in remission 4 months after the cessation of the therapy. We proposed that patients who have psoriasis or predisposition to psoriasis must be carefully followed after BCG vaccination. © Oxford University Press 2004; all rights reserved.

Sayin, Meral Y. | Kaya, Bektas | Bakkal, Bekir Hakan | Altundag, Kadri | Altundag, Muzaffer B.

Article | 2007 | MEDICAL ONCOLOGY24 ( 4 ) , pp.379 - 383

In this prospective study, we investigated the effects of hypofractionated radiotherapy for patients with high-grade gliomas. About 31 patients with glioblastoma multiforme or anaplastic astrocytoma were studied between October 2003 and December 2004. Hypofractionated radiotherapy (3 Gy/fraction/day) was delivered to a total dose of 45 Gy in 15 fractions in 10 patients (32%) who had total excision before radiotherapy and to a total dose of 54 Gy in 18 fractions in 21 patients (68%) who had subtotal excision or biopsy alone. Sex, age, type of surgery, tumor grade, Karnofsky performance status, time between surgery and initiation of r . . .adiotherapy, and total radiotherapy dose were analyzed as potential prognostic factors for survival using the univariate log-rank method. The median follow-up was 15 months (4-16 months). A total of 15 patients (48%) died of their illness; 16 patients (52%) were still alive at the last follow-up. The median survival time was 8 months. Actuarial 1-year overall survival was 40%. Type of surgery, timing of radiotherapy after surgery, and initial Karnofsky performance status were significant prognostic factors for survival. No grade 3-4 acute or late neurotoxicity was observed. The tolerance of patients to hypofractionated RT was not different from that for con- ventional radiotherapy. This treatment schedule can be used for patients with high-grade gliomas. Future investigations are needed to determine the optimal fractionation for high-grade gliomas Daha fazlası Daha az

Gültekin, Fatma Ayça | Bakkal, Bekir Hakan | Sümer, Demet | Köktürk, Füruzan | Bektaş, Sibel

Article | 2013 | Balkan Medical Journal30 ( 4 ) , pp.369 - 374

Background: Acute radiation proctitis is a common complication of pelvic radiation and management of acute radiation proctitis is under evaluation. The beneficial effects of ozonated olive oil (OzOO) have already been shown in the treatment of chronic wounds. Thus, this study was designed to evaluate the therapeutic effects of topical OzOO on acute radiation proctitis. Aims: To evaluate the therapeutic effects of topical OzOO on acute radiation proctitis. Study Design: Animal experimentation. Methods: Rats were divided into three groups: control; irradiation+saline (1 mL); and irradiation +OzOO (1 mL). A single fraction of 17.5 Gy w . . .as delivered to each rat. The OzOO was administered rectally each day after irradiation. Each rat was observed daily for signs of proctitis. Irradiated rats were euthanised on days 5 and 10. The mucosal changes were evaluated macroscopically and pathologically. Results: According to the clinical findings, five rats in the irradiation+saline group showed Grade 4 symptoms on the 10th day. Macroscopic finding scores on the 10th day in the irradiation+saline and irradiation+OzOO groups were statistically significantly different. On pathological examination, radiationinduced mucosal damage was the most prominent 10 days after irradiation in saline-treated rats. On the 10th day, the irradiation+OzOO group showed mild inflammation and slight crypt change, which corresponded to Grade 1 pathological findings. Conclusion: OzOO attenuates macroscopic and pathological findings of acute radiation proctitis in rats. Background: Acute radiation proctitis is a common complication of pelvic radiation and management of acute radiation proctitis is under evaluation. The beneficial effects of ozonated olive oil (OzOO) have already been shown in the treatment of chronic wounds. Thus, this study was designed to evaluate the therapeutic effects of topical OzOO on acute radiation proctitis. Aims: To evaluate the therapeutic effects of topical OzOO on acute radiation proctitis. Study Design: Animal experimentation. Methods: Rats were divided into three groups: control; irradiation+saline (1 mL); and irradiation +OzOO (1 mL). A single fraction of 17.5 Gy was delivered to each rat. The OzOO was administered rectally each day after irradiation. Each rat was observed daily for signs of proctitis. Irradiated rats were euthanised on days 5 and 10. The mucosal changes were evaluated macroscopically and pathologically. Results: According to the clinical findings, five rats in the irradiation+saline group showed Grade 4 symptoms on the 10th day. Macroscopic finding scores on the 10th day in the irradiation+saline and irradiation+OzOO groups were statistically significantly different. On pathological examination, radiationinduced mucosal damage was the most prominent 10 days after irradiation in saline-treated rats. On the 10th day, the irradiation+OzOO group showed mild inflammation and slight crypt change, which corresponded to Grade 1 pathological findings. Conclusion: OzOO attenuates macroscopic and pathological findings of acute radiation proctitis in rats Daha fazlası Daha az

Akman, Tulay | Tanrıverdı, Ozgur | Ozturk, Mehmet A. | Petekkaya, Ibrahim | Bakkal, Bekir Hakan | Sonmez, Ozlem U. | Avcı, Nilufer

Article | 2014 | Uluslararası Hematoloji-Onkoloji Dergisi24 ( 3 ) , pp.195 - 201

Günümüzde onkoloji alanında her geçen gün deneysel ve klinik araştırmaların sonucu olarak yeni bir gelişme olmaktadır. Kişi başına düşen yayın sayısına bakıldığında, Türkiye diğer gelişmiş Avrupa ülkelerinden epeyce geride yer almaktadır. Örneğin tüm dünyada kanser alanında yapılmış olan yayınların sayısı 2,134,964 iken, Türkiye’dekilerin sayısının toplamı 15.576’dır ve toplam yayın sayısı nüfus oranları ile karşılaştırıldığında diğer gelişmiş Avrupa ülkelerine göre epeyce geride kalmaktadır. Türkiye’de klinik çalışmaların önündeki en önemli engellerin finansal sorunlar, çalışma şartlarının zorlukları, iş yoğunluğu nedeniyle zaman k . . .ısıtlılığı, deneyimli-eğitimli insan gücü eksikliği, bilimsel çalışmanın tüm aşamalarında yardımcı olacak bir ekibin eksikliği, proje hazırlama ve etik kurul izin sürecinde yaşanan sıkıntılar, motivasyon eksikliği olduğu düşünülebilir. Biz genç onkologlar olarak bu yazımızda; dünya genelinde ülkemizin bilimsel ve klinik araştırmalardaki yerini, bilimsel araştırmaların yapılamamasının nedenlerini, ülkemizde yapılmakta olan yayınların çeşit ve kalitesini, bizim ülkemize ait varolan ger- çekleri ve bunlara yönelik getirilebilecek çözüm önerilerini tartışmayı amaçladık. There is a new improvement in oncology nearly in every day as a result of preclinical or clinical. As the number of publication per capita, Turkey is far behind the other developed European countries. For example, the number of publications in oncology field is 2.134.964 in the world, it is 15.576 in our country. The most important obstacles for clinical trials in Turkey may be listed as financial problems, difficulties of working conditions, time limitation due to work intensity, inadequate experienced/trained man-power, absence of assistance team at all steps of a scientific trial, difficulties faced during project planning and ethics committee submissions, and lack of motivation. In this article, we, as young oncologists, aimed to discuss the place of Turkey in areas of scientific and clinical trials in the world; underlying causes for inadequate number, type and quality of national studies and possible solution proposals in our countr Daha fazlası Daha az

Bakkal, Bekir Hakan | Vural T. | Elmas O. | Yildiz O. | Kokturk F.

Article | 2014 | Journal of Cancer Research and Therapeutics10 ( 3 ) , pp.558 - 562

Aims: The aim of this study was to evaluate and compare the effect of radiotherapy on testicles with different treatment positions and plans for rectal cancer patients. Settings and Design: Mono-institutional prospective study. Patients and Methods: Three different plans; supine 4-fields (s4f), prone 4-fields (p4f), and prone 3-fields (p3f) of 15 male patients with rectal carcinoma receiving 45 Gy pelvic radiotherapy were evaluated. Testicular doses in each plan were calculated. Since the localizations of the primary tumor may affect testicular dose, boost doses were not taken into account. Statistical Analysis Used: Kruskal Wallis . . .test, Pearson and Spearman correlation analysis. Results: Median cumulative testicular doses of s4f, p4f, and p3f plans were 19.8, 69.3, and 100.8 cGy, respectively (P = 0.013). Median V0.5 (Volume receiving more than 0.5 Gy) and V1 (Volume receiving more than 1 Gy) for testicles were also significantly lower in s4f plans (3%, 60.7%, and 78.1% for V0.5 and 0.3%, 35.8%, and 52.3% for V1 in s4f, p4f, and p3f, respectively) (P = 0.001). The median distances between lower edge of fields and testicles in s4f, p4f, and p3f plans were 65 mm, 29 mm, and 29 mm, respectively (P < 0.01). Median bladder doses were significantly lower in p3f plans (P = 0.002). Conclusions: S4f external beam radiotherapy for rectal carcinoma allows better testicular dose than p3f and p4f. The probably reason was the increase of distance between lower edge of the field and testicles Daha fazlası Daha az

Karabey, M. S. | Erkal, E. Y. | Yolcu, A. | Bakkal, Bekir Hakan | Sarper, B. | Aksu, G. | Erkal, H. S.

Conference Object | 2014 | EUROPEAN JOURNAL OF CANCER50 , pp.558 - 562

WOS: 000351589200179