A Ates

Publications (6)11.82 Total impact

• Article: Association of the PTPN22 gene polymorphism with autoantibody positivity in Turkish rheumatoid arthritis patients.

  A Ates, Y Karaaslan, E Karatayli, E Ertuğrul, S Aksaray, A Türkyilmaz, G Ozet
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  ABSTRACT: The PTPN22 C1858T gene polymorphism has been recently reported to be associated with rheumatoid arthritis (RA) in European and North American ancestry. In contrast, the frequency of PTPN22 C1858T polymorphism is extremely rare in Asian and African populations. As the genetic heterogeneity between populations is clearly present in RA, we wanted to investigate whether the PTPN22 C1858T polymorphism is associated with RA in Turkey and with autoantibody positivity. A total of 323 RA patients and 426 healthy controls were genotyped by polymerase chain reaction restriction fragment length polymorphism for the PTPN22 C1858T polymorphism (rs2476601). The frequencies of heterozygote genotype (CT) were 8.4% in RA patients and 5.4% in the healthy controls, respectively [odds ratio (OR): 1.6, P = 0.14]. The homozygote genotype (T/T) was absent in both RA patients and the healthy controls. When compared with the healthy controls, we found the significant associations between the frequency of PTPN22 heterozygote (CT) polymorphism and RA patients with RF positivity and anti-CCP positivity, respectively (OR: 2.05, P = 0.04 and OR: 2.1, P = 0.03, respectively). Our study suggests that the PTPN22 C1858T polymorphism acts as a susceptibility gene for autoantibody-positive RA in Turkey.
  Tissue Antigens 07/2011; 78(1):56-9. · 2.59 Impact Factor
• Article: Results for audiology and distortion product and transient evoked otoacoustic emissions in patients with systemic lupus erythematosus.

  H Karabulut, M Dagli, A Ates, Y Karaaslan
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  ABSTRACT: The aim of the current study was to investigate hearing loss and cochlear function in patients with systemic lupus erythematosus, using audiology, distortion product otoacoustic emissions and transient evoked otoacoustic emissions. Prospective, case-control study. The study included 26 randomised patients with systemic lupus erythematosus (52 ears) and 30 healthy control subjects (60 ears). Pure tone audiometry was performed at 250 and 500 Hz and at 1, 2, 4, 6, 8, 10, 12, 14 and 16 kHz. Distortion product otoacoustic emissions and transient evoked otoacoustic emissions were measured using Biologic System equipment with Scout Acoustic Emissions System software. The distortion product otoacoustic emission signal responses were significantly different only at 750 Hz, while the distortion product otoacoustic emission signal-noise ratios were significantly different at 750 Hz and 6 kHz (p < 0.05), comparing patients and controls. The transient evoked otoacoustic emission signal-noise ratios were significantly different at 2 and 3 kHz, comparing patients and controls (p < 0.05). The transient evoked otoacoustic emission total signal-noise ratios were significantly different, comparing patients and controls (p < 0.05). In addition, the pure tone audiometry thresholds were significantly different at 250 and 500 Hz and at 1, 2, 10 and 12 kHz, comparing patients and controls (p < 0.05). Our findings do not completely agree with those of previous temporal bone histopathological studies. However, our results do support a general picture of low frequency hearing loss in systemic lupus erythematosus patients. We consider these results to be related to endolymphatic and cochlear hydrops, and we suggest that electrocochleography could be performed in further studies for clarification of this subject.
  The Journal of Laryngology & Otology 10/2009; 124(2):137-40. · 0.60 Impact Factor
• Article: PTPN22 gene polymorphism in Takayasu's arteritis.

  N Sahin, K Aksu, S Kamali, M Bicakcigil, Z Ozbalkan, I Fresko, H Ozer, S Akar, A M Onat, V Cobankara, S Kiraz, M A Oztürk, E Tunç, E Yücel, A Ates, G Keser, M Inanc, H Direskeneli, G Saruhan-Direskeneli
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  ABSTRACT: Takayasu's arteritis (TA) is a chronic, rare granulomatous panarteritis of unknown aetiology involving mainly the aorta and its major branches. In this study, genetic susceptibility to TA has been investigated by screening the functional single nucleotide polymorphism (SNP) of PTPN22 gene encoding the lymphoid-specific protein tyrosine phosphatase. Totally, 181 patients with TA and 177 healthy controls are genotyped by PCR-RFLP method for the SNP rs2476601 (A/G) of PTPN22 gene. Polymorphic region was amplified by PCR and digested with Xcm I enzyme. Detected frequencies of heterozygous genotype (AG) were 5.1% (9/177) in control group and 3.8% (7/181) in TA group (P = 0.61, odds ratio: 0.75, 95% CI: 0.3, 2.0). No association with angiographic type, vascular involvement or prognosis of TA was observed either. The distribution of PTPN22 polymorphism did not reveal any association with TA in Turkey.
  Rheumatology (Oxford, England) 06/2008; 47(5):634-5. · 4.24 Impact Factor
• Article: Protective role of antioxidant vitamin E and catechin on idarubicin-induced cardiotoxicity in rats.

  S Kalender, Y Kalender, A Ates, M Yel, E Olcay, S Candan
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  ABSTRACT: Idarubicin is an anthracycline antibiotic extensively used in acute leukemia. In the present study we investigated whether vitamin E and catechin can reduce the toxic effects of idarubicin. Vitamin E (200 IU kg(-1) week(-1)), catechin (200 mg kg(-1) week(-1)), idarubicin (5 mg kg(-1) week(-1)), idarubicin + vitamin E (200 IU kg(-1) week(-1)), and idarubicin + catechin (200 mg kg(-1) week(-1)) combinations were given to male Sprague-Dawley rats weighing 210 to 230 g (N = 6/group). Idarubicin-treated animals exhibited a decrease in body and heart weight, a decrease in myocardial contractility, and changes in ECG parameters (P<0.01). Catechin + idarubicin- and vitamin E + idarubicin-treated groups exhibited similar alterations, but changes were attenuated in comparison to those in cardiac muscle of idarubicin-treated rats (P<0.05). Superoxide dismutase and catalase activity was reduced in the idarubicin-treated group (P<0.05). Glutathione peroxidase levels were decreased in the idarubicin-treated group (P<0.05) and reached maximum concentrations in the catechin- and catechin + idarubicin-treated groups compared to control (P<0.01). Malondialdehyde activity was decreased in the catechin + idarubicin-treated groups compared to control and increased in the other groups, reaching maximum concentrations in the vitamin E-treated group (P<0.01). In electron microscopy studies, swelling of the mitochondria and dilatation of the sarcoplasmic reticulum of myocytes were observed in the idarubicin-treated groups. In groups that were given idarubicin + vitamin E and idarubicin + catechin, the only morphological change was a weak dilatation of the sarcoplasmic reticulum. We conclude that catechin and vitamin E significantly reduce idarubicin-induced cardiotoxicity in rats.
  Brazilian Journal of Medical and Biological Research 11/2002; 35(11):1379-87. · 1.13 Impact Factor
• Article: Fouling of reverse osmosis and nanofiltration membranes by dairy industry effluents.

  M Turan, A Ates, B Inanc
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  ABSTRACT: Fouling experiments of nanofiltration (NF) and reverse osmosis (RO) are reported for treatment of the effluent of chemical-biological treatment plant and the original effluent of dairy industry respectively. In the experiments, a thin film composite type of spiral wound was used and fitted with flowmeters and pressure sensors. The feed water was stored into a feed tank and passed a fine filter and was pumped to membrane. Brine and permeate were recirculated back to the feed tank. Membrane fouling was investigated with 16 and 30% water recovery of a single membrane at different pressures and flowrates for RO and NF membranes respectively. Fouling is evaluated with a relationship between relative flux (J/Jo) which is the ratio of the flux at any time during the fouling test to the initial flux and relative resistance (Rf/Rm) which is the ratio of fouling (cake) layer resistance to clean membrane resistance. Turbidity, conductivity, chemical oxygen demand (COD), total suspended solids (TSS) and total hardness were measured in the feed and permeate side of each membrane. The effluent total hardness concentrations of chemical-biological treatment plant were found greater than the influents. The results are presented in terms of the relative flux as a function of time related to hydrodynamic conditions and pollution characteristics of wastewater. The permeate water flux of RO membrane decreases more rapidly than NF membrane, the relative flux decreases with increasing the fouling layer resistance, Rf onto membrane surface. 50% the drop of permeate flux was observed for RO and NF membranes after 50 h and 80 h of operation, respectively. The fouling rate increases with an increase in the concentration of the wastewater constituents in the dairy industry. The relative flux decreased 10 and 20% with increasing chemical oxygen demand (COD) from 5,000 mgl-1 to 10,000 mgl-1 and from 45 mgl-1 to 450 mgl-1 for RO and NF membranes, respectively after 45 h of time. Fouling of membranes resulted in 100% increase of specific energy consumption as the relative permeate fluxes of NF and RO membranes decreased 30 and 40% respectively. The average of specific energy consumption was obtained at 6 and 10 kWhm-3; consequently, operational costs were estimated at U.S. $0.45 m-3 and U.S. $0.75 m-3 for NF and RO units respectively. Also, operational cost for chemical-biological treatment was found at U.S. $0.30 m-3.
  Water Science & Technology 02/2002; 45(12):355-60. · 1.12 Impact Factor
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  Available from: Neslihan Yilmaz

  Article: Takayasu's arteritis in Turkey - clinical and angiographic features of 248 patients.

  M Bicakcigil, K Aksu, S Kamali, Z Ozbalkan, A Ates, O Karadag, H T E Ozer, E Seyahi, S Akar, F Onen, [......], E Tunc, M A Ozturk, I Fresko, Y Karaaslan, N Akkoc, A E Yücel, S Kiraz, G Keser, M Inanc, H Direskeneli
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  ABSTRACT: Takayasu's arteritis (TA) is a chronic, inflammatory vasculitis affecting the aorta and its major branches. Although it is more prevalent in Far-East Asia, the distribution of the disease is worldwide with different vascular involvement patterns and clinical manifestations. The objective of this study was to evaluate the demographic, clinical, angiographic and prognostic features of TA patients in Turkey. Clinical and angiographic findings of 248 TA patients (228 female, 27 male) followed at 15 Rheumatology Centers were prospectively evaluated according to a predefined protocol. The mean age was 40.1 years (30.2 years at the clinical onset). Clinical manifestations included constitutional symptoms in 66%, absent or diminished pulses in 88%, bruits in 77%, extremity pain in 69%, claudication in 48%, hypertension in 43% and cerebrovascular accidents (CVA) in 18% of the patients. Renal artery stenosis, aortic regurgitation and pulmonary hypertension were present in 26%, 33% and 12%, respectively. According to the new angiographic classification, type V (50.8%) and Type I (32%) were the most frequent types of involvement. Corticosteroids were the main treatment in 93% of the patients alone (9%) or in combination with immunosuppressive agents (84%). Most frequently preferred immunosuppressive agents were methotrexate (63%), azathioprine (22%) and cyclophosphamide (13%). Remission was observed at least once in 94% of the patients and sustained remission in 71% during follow-up. The demographical, clinical and angiographic findings of TA patients in our series were similar to those reported from Japan, Brazil and Colombia. Combination therapies with immunosuppressive agents were the preferred choice of treatment in Turkey.
  Clinical and experimental rheumatology 27(1 Suppl 52):S59-64. · 2.15 Impact Factor