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Dive into the research topics where Ramazan Ulu is active.

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Featured researches published by Ramazan Ulu.


Food and Chemical Toxicology | 2012

Regulation of renal organic anion and cation transporters by thymoquinone in cisplatin induced kidney injury.

Ramazan Ulu; Ayhan Dogukan; Mehmet Tuzcu; Hasan Gencoglu; Mustafa Ulas; Necip Ilhan; Irfana Muqbil; Ramzi M. Mohammad; Omer Kucuk; Kazim Sahin

In previous studies, we have demonstrated the biological activity of thymoquinone (TQ), an active compound extracted from the Nigella sativa plant, against cisplatin-induced neurotoxicity. Recenty, it was observed that there is an inherent lack in regulation of renal organic anion and cation transporters in cisplatin-induced nephrotoxicity. Here, we report, for the first time, the effect of TQ on alterations in the renal expression of organic anion transporters (OATs) and organic cation transporters (OCTs), as well as multidrug resistance-associated proteins (MRPs) in rats treated with cisplatin. Twenty-eight 8-week-old male Wistar rats were divided into four groups of control, TQ treated (10 mg/kg b.w. in drinking water for 5 days), cisplatin (7 mg/kg b.w., i.p.) and TQ and cisplatin combination treatment. Cisplatin-induced malondialdehyde (MDA) and 8-isoprostane increase was found to be markedly reduced in rats treated with TQ. In cisplatin only treated rats, the induced renal injury increased protein levels of the efflux transporters MRP2 and MRP4 while expression of OAT1, OAT3, OCT1 and OCT2 was reduced. In combination TQ- and cisplatin-treated rats, expression of MRP2 and MRP4 proteins was decreased in the kidneys. Conversely, TQ treatment increased levels of OCT1, OCT2, OAT1 and OAT3 and decreased levels of 8-isoprostane and MDA levels in cisplatin-treated rats. In conclusion, the present study shows that the TQ synergizes with its nephroprotective effect against cisplatin-induced acute kidney injury in rats.


Renal Failure | 2015

The renoprotective effect of curcumin in cisplatin-induced nephrotoxicity

Sıddık Ugur; Ramazan Ulu; Ayhan Dogukan; Ali Gurel; Irem Pembegul Yigit; Nevzat Gözel; Bilge Aygen; Necip Ilhan

Abstract The polyphenol curcumin has several pharmacological effects, including antioxidant, anti-inflammatory and anti-cancer features. In this study, we evaluated the effects of curcumin in cisplatin-induced nephrotoxicity in rats. Male Wistar rats were divided into four groups: (1) control; (2) cisplatin (7 mg/kg body weight, intraperitoneal as a single dose); (3) curcumin (100 mg/kg via gavage, for 10 days); and (4) cisplatin and curcumin. The cisplatin-treated rats exhibited kidney injury manifested by increased serum urea and creatinine (p < 0.05). The kidney tissue from the cisplatin treated rats also exhibited a significant increase in the malondialdehyde (MDA) levels (p < 0.05). The treatment with curcumin prevented a rise in the serum urea, creatinine and MDA levels when compared to the control group kidneys (p < 0.05). The analysis the nicotinamide phosphoribosyltransferase (NAMPT) and sirtuin (SIRT) proteins (SIRT1, SIRT3 and SIRT4), which play important roles in the resistance to stress and the modulation of the threshold of cell death, showed similar trends (p < 0.05). In the cisplatin-only treated rats, the induced renal injury decreased the levels of the NAMPT and SIRT proteins. Conversely, the curcumin increased the levels of the NAMPT and SIRT proteins in the cisplatin-treated rats (p < 0.05). These data suggest that curcumin can potentially be used to reduce chemotherapy-induced nephrotoxicity, thereby enhancing the therapeutic window of cisplatin.


Renal Failure | 2015

Can serum NGAL levels be used as an inflammation marker on hemodialysis patients with permanent catheter

Irem Pembegul Yigit; Huseyin Celiker; Ayhan Dogukan; Necip Ilhan; Ali Gurel; Ramazan Ulu; Bilge Aygen

Abstract Background: Neutrophil gelatinase-associated lipocalin (NGAL) is a member of lipocalin family and released from many tissues and cells. We aimed to investigate the relationship among serum NGAL levels, the inflammation markers (IL-6, hs-CRP, TNF-α) and different vascular access types used in dialysis patients. Methods: The study population included 90 patients and 30 healthy age-matched controls. The patients were divided into three groups (I, II, III) and group IV included the controls. In group I and II, the patients were with central venous permanent catheter and arterio-venous fistula, respectively. Group III included 30 patients with chronic renal failure. Hemogram, biochemical assays, ferritin, IL-6, hs-CRP, TNF-α, and NGAL were evaluated in all groups. Results: Serum NGAL levels were markedly higher in group I than in group II (7645.80 ± 924.61 vs. 4131.20 ± 609.87 pg/mL; p < 0.05). Positive correlation was detected between NGAL levels and duration of catheter (r: 0.903, p: 0.000), hs-CRP (r: 0.796, p: 0.000), IL-6 (r: 0.687, p: 0.000), TNF-α (r: 0.568, p: 0.000) levels and ferritin (r: 0.318, p: 0.001), whereas NGAL levels were negatively correlated with serum albumin levels (r: −0.494, p: 0.000). In multiple regression analysis, duration of catheter hs-CRP and TNF-α were predictors of NGAL in hemodialysis patients. Conclusion: Inflammation was observed in hemodialysis patients and increases with catheter. Our findings show that a strong relationship among serum NGAL levels, duration of catheter, hs-CRP and TNF-α. NGAL may be used as a new inflammation marker in hemodialysis patients.


Journal of Vascular Access | 2015

Relationships between plasma pentraxin 3 levels and inflammation markers patients with tunneled permanent catheter in hemodialysis.

Irem Pembegul Yigit; Ayhan Dogukan; Hulya Taskapan; Melda Cömert; Necip Ilhan; Ramazan Ulu; Bilge Aygen

Purpose Vascular access (VA) devices may contribute to chronic inflammation in hemodialysis (HD). Pentraxin 3 (PTX3) is a recently discovered acute phase protein that responds more rapidly than other inflammatory markers. This study compared PTX3 and other markers between HD patients and healthy controls. Methods The study population included 30 patients with tunneled permanent catheter (TPC), 30 patients with arteriovenous fistula (AVF) and 30 healthy controls. Hemogram, biochemical assays, ferritin, high sensitive C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α) and PTX3 were evaluated in all groups. Results PTX levels were highest in HD patients with TPC, intermediated in HD patients with AVF and lowest in healthy controls (5.2 + 2.4 vs. 3.1 + 1.3 vs. 1.8 + 0.7, p<0.001 for all comparisons). PTX3 levels correlated strongly to hs-CRP (r = 0.857) and moderately to TNF-α, NLR, ferritin and total neutrophil count. PTX3 and albumin levels had a negative correlation. PTX3 levels were higher in patients with 8 months of TPC than those with 7 months or less. Conclusions PTX3 levels are significantly elevated in all patients on HD, but presence and extended duration of TPC are associated with incrementally higher levels of PTX3 and other inflammatory markers. PTX3 and NLR may be useful in assessing chronic inflammatory states in HD.


Food and Chemical Toxicology | 2018

The effects of Mucuna pruriens on the renal oxidative stress and transcription factors in high-fructose-fed rats

Ramazan Ulu; Nevzat Gözel; Mehmet Tuzcu; Cemal Orhan; Irem Pembegul Yigit; Ayhan Dogukan; Hafize Telceken; Özlem Üçer; Zeki Kemeç; Dilara Kaman; Vijaya Juturu; Kazim Sahin

In the present study, we evaluated the effects of M. pruriens administration on metabolic parameters, oxidative stress and kidney nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling pathways in high-fructose fed rats. Male rats (n = 28) were divided into 4 groups as control, M. pruriens, fructose, and M. pruriens plus fructose. All rats were fed a standard diet supplemented or no supplemented with M. pruriens (200 mg/kg/d by gavage). Fructose was given in drinking water for 8 weeks. High fructose consumption led to an increase in the serum level of glucose, triglyceride, urea and renal malondialdehyde (MDA) levels. Although M. pruriens treatment reduced triglyceride and MDA levels, it did not affect other parameters. M. pruriens supplementation significantly decreased the expression of NF-ҡB and decreased expression of Nrf2 and HO-1 proteins in the kidney. This study showed that the adverse effects of high fructose were alleviated by M. pruriens supplementation via modulation of the expression of kidney nuclear transcription factors in rats fed high fructose diet.


Turkish Journal of Medical Sciences | 2017

Plasma urotensin II levels in primary Raynaud's phenomenon and systemic sclerosis

Nevzat Gözel; Ahmet Karataş; Meltem Yardim; Mesude Seda Kinaci; Ramazan Ulu; Fatih Demircan; Faruk Kılınç; Burak Öz; Emir Dönder; Suleyman Aydin; Süleyman Serdar Koca

Background/aim: The pathogenesis of Raynauds phenomenon (RP) has not yet been fully elucidated. RP is characterized by exaggerated cold-induced vasoconstriction. Urotensin II (UII) is a potent vasoconstrictor. The aim of the present study was to evaluate plasma UII levels in both primary RP and secondary RP associated with systemic sclerosis (SSc).Materials and methods: Fifteen patients with primary RP, 30 patients with RP secondary to SSc, and 30 healthy controls (HC) were included in the study. Raynaud condition scores (RCS) were determined in the primary RP and SSc groups. Modified Rodnan skin score (MRSS) was determined for the SSc patients. Plasma UII level was analyzed by the ELISA method. Results: When compared to the HC group, plasma UII level was lower in the secondary RP group, but not in the primary RP group. Plasma UII level was not directly related to RCS in either the primary or secondary RP group. Moreover, it was not correlated with MRSS in the secondary RP group.Conclusion: The results of the present study suggest that UII is not associated with primary RP. Its level was lower in the secondary RP (SSc) patients. Therefore, it can be concluded that decreased UII level is related to SSc instead of RP.


SDÜ Sağlık Bilimleri Dergisi | 2015

Waardenburg Sendromu ve nefrotik sendrom birlikteliği

Irem Pembegul Yigit; Ali Gurel; Bilge Aygen; Ramazan Ulu; Ayhan Dogukan

Waardenburg Sendromu siklikla farkli derecelerde isitme kaybi, sac ve deride pigmentasyon degisiklikleri ile karakterize kalitsal bir sendromdur. Waardenburg Sendromunda bobrek anomalileri nadiren bildirilmis olup, nefrotik sendrom olgusuna rastlanmamistir. Waardenburg Sendromu tanisi olan 32 yasindaki erkek hasta yuz, goz cevresi ve bacaklarda sislik sikayeti ile klinigimize basvurdu. Klinik ve laboratuar verileriyle nefrotik sendrom tanisi alan hastaya yapilan bobrek biyopsisi sonucu minimal degisiklik hastaligi olarak raporlandi. Kortikosteroid tedavisi ile 10.gunde remisyon saglandi, doz azaltilarak 5 ay tedaviye devam edildi. Ilk yilin sonunda hasta hala remisyonda idi. Burada Waardenburg Sendromu ve glomeruler patolojinin birlikte oldugu bir olgu sunulmustur.


Turkish Nephrology Dialysis Transplantation | 2010

Severe Pancytopenia Induced by Low-dose Methotrexate in a Hemodialysis Patient

Irem Pembegul Yigit; Ramazan Ulu; Yener Yildiz; Ayhan Dogukan; Huseyin Celiker

Methotrexate has been used as an important alternative therapy in the treatment of various rheumatic diseases. It is primarily cleared by the kidney. Life-threatening marrow suppression in hemodialysis patients has been reported. A 35-year-old woman undergoing hemodialysis developed severe stomatitis and pancytopenia after low-dose methotrexate treatment for rheumatoid arthritis. She recovered after folinic acid, granulocyte colony-stimulating factor, antibiotic and daily hemodialysis therapy.


Neurology and Therapy | 2016

The Impact of Red Blood Cell Distribution Width and Neutrophil/Lymphocyte Ratio on the Diagnosis of Major Depressive Disorder

Fatih Demircan; Nevzat Gözel; Faruk Kılınç; Ramazan Ulu; Murat Atmaca


Turkish Nephrology Dialysis Transplantation | 2013

Modulation of Nrf2/HO-1 by Thymoquinone During Cisplatin-Induced Nephrotoxicity

Ramazan Ulu; Ayhan Dogukan; Mehmet Tuzcu; Ali Gurel; Irfana Muqbil; Ramzi M. Mohammad; Kazim Sahin

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