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Featured researches published by U. Erken.


Renal Failure | 2005

Uncommon side effect of MMF in renal transplant recipients

Mustafa Balal; Erkan Demir; Saime Paydas; Yasar Sertdemir; U. Erken

Mycophenolate mofetil (MMF) is a potent immunosuppressive agent used in renal transplantation. Gastrointestinal and hematological side effects are commonly observed, but hepatotoxicity has not been reported. In this study, we assessed MMF-related hepatotoxicity in renal transplant recipients. A total of 124 renal transplantation recipients (RTRs) were evaluated for elevated liver enzymes associated with MMF, and 79 patients were enrolled to the study. Patients used MMF 2 g/day. The patients who had progressive increase in liver enzymes after renal transplantation and their AST, ALT, GGT, ALP, bilirubin levels, hepatitis, cytomegalovirus (CMV), abdominal ultrasonography, duration of hepatotoxicity, and decreased dosage or withdrawal of MMF were recorded. Also, we evaluated their liver enzymes while the patients were on the waiting list. Of the 79 patients, 11 patients (13.9%) had a progressive increase in liver enzymes. The median (min–max) age of the patients with MMF-hepatotoxicity was 29 (19–54) and 72.7% of them were male. None of the patients had hepatitis B or C, CMV infection, or other possible causes for elevated liver enzymes and their abdominal ultrasonography were normal. High liver enzyme levels regressed after the withdrawal (n = 6) or reduce dosage (n = 5) of MMF. The median time of the increase in liver enzymes was 28 (4–70) days and after 50% reduction or withdrawal of MMF, returned to normal values in 16 (4–210) days. The median levels of ALT in waiting list (I), before (II), and after (III) reduction dosage or withdrawal of MMF were 22.0 (3–22), 222.0 (51–508), and 33.0 (21–64) U/L, respectively (p I–II = 0.004, p I–II = 0.013, and p II–III = 0.005). There were no differences for ALP, GGT, total bilirubin, and direct bilirubin levels. Also, the correlation between recovery time of ALT and persistence time of ALT elevation before adjustment of MMF was significant (r = 0.739, p = 0.009). Consequently, after renal transplantation, hepatotoxicity can occur due to a lot of reason including MMF usage. If hepatotoxicity related to MMF is not considered, especially in the early period of renal transplantation, resolution of hepatotoxicity can be required long term.


Transplantation Proceedings | 2010

Bone Disease in Renal Transplantation and Pleotropic Effects of Vitamin D Therapy

M.M. Sikgenc; Semra Paydas; Mustafa Balal; Erkan Demir; Cemal Kurt; Yasar Sertdemir; Figen Binokay; U. Erken

Osteoporosis, osteopenia, and osteonecrosis are common in renal transplant recipients. In this study, we evaluated relationship between bone mineral density (BMD) and posttransplant duration; creatinine clearance; serum levels of glucose, calcium, phosphorus, alkaline phosphatase, vitamin D (vitD), parathormone, magnesium, C telopeptide, osteocalcin, lipids, and vit D therapy. Eighty five subjects included in this study had a mean age of 36.25 ± 10.5 years. At least at 6-month intervals we measured femoral neck (FN) and lumbar vertebra (LV) by DEXA and biochemical parameters. VitD was prescribed in 57 patients (vitDG). The mean duration of posttransplantation follow-up was 9.82 ± 2.72 months. T scores (TS) of FN and LV were normal in 29.4% and 21.2%; osteopenia in 56.5% and 49.4%; and osteoporosis in 12.1% and 29.4% of patients, respectively. Upon follow-up, TS improved significantly from -1.58 to -1.46 in FN and from -1.88 to -1.70 in LV (P < .05 for both). In patients receiving vitDG, TS improved significantly from -1.74 to -1.61 on FN and from -2.16 to -1.97 on LV (P < .05 for both). Osteocalcin and vitDG levels decreased in all patients (P < .05 for all). Blood urea nitrogen and serum creatinine increased (P < .05). In VitDG cohort, triglyceride levels decreased (P < .05) with unchanged blood glucose values; but among the other patients, triglycerides were unchanged but glucose levels had increased (P < .05). Bone disease including osteopenia or osteoporosis was observed among 70%. During the follow-up period, BMD increased significantly from baseline at 9.82 ± 2.72 months. VitD therapy caused more prominent improvements in BMD and decreases in serum triglycerides as well as mutigated the increase in blood glucose.


Transplantation Proceedings | 2011

Avascular Osteonecrosis and Accompanying Anemia, Leucocytosis, and Decreased Bone Mineral Density in Renal Transplant Recipients

Semra Paydas; Mustafa Balal; Erkan Demir; Yasar Sertdemir; U. Erken

BACKGROUND Avascular osteonecrosis (AVN) is a complication of renal transplantation. In this study, we present 12 cases of AVN associated with renal transplantation. METHODS Renal transplant recipients (RTRs) with AVN (group I [GI]) were evaluated by using magnetic resonance imaging and blood urea nitrogen, creatinine, glucose, calcium, phosphorus, magnesium, alkaline phosphatase, parathyroid hormone, and urine analysis. We evaluated bone mineral density (BMD) of the femoral neck and lumbar vertebrae. All patients were treated with steroids, cyclosporine, or tacrolimus plus mycophenolate mofetil. Twenty-six RTRs (GII) without AVN were randomly selected as control subjects. RESULTS The mean ages of GI and GII, were 33.81 ± 6.72 and 34.00 ± 7.65 years respectively (P > .05). The mean interval between transplantation and development of AVN was 12.08 ± 6.48 months. Although levels of blood urea nitrogen, creatinine, calcium, magnesium, and parathyroidhormone, as well as glucocorticoid doses in the first 12 months were similar in GI and GII, there were significant differences in serum alkaline phosphatase, hemoglobin levels, and white blood cell count between GI and GII (P < .05 for each). BMD T score <-1.5 was observed in 8/9 GI and 15/26 patients in GII. All of the patients with AVN except 1, were followed with conservative measures including calcium, magnesium, and vitamin D replacement therapies, bisphosphonate, and reduced or ceased glucocorticoid treatment. Although T scores of the femoral head were similar in GI and GII, the lumbar vertebral T score was significantly lower in GI than in GII (P < .052). CONCLUSION AVN developed within the first year after transplantation. Decreased lumbar vertebral BMD, which can be an indicator of glucocorticoid effect, accompanied AVN in nearly all patients. Despite the absence of renal dysfunction, increased bone destruction, anemia, and leucocytosis were coincidental or accompanying findings in our patients with AVN.


Journal of Endourology | 2008

Patient tolerance during cystoscopy: a randomized study comparing lidocaine hydrochloride gel and dimethyl sulfoxide with lidocaine.

Erkan Demir; Mete Kilciler; Selahattin Bedir; U. Erken

PURPOSE Cystoscopy is one of the most common examinations in urologic outpatient clinics. Various anesthetic approaches have been used to make cystoscopy more tolerable for patients. The aim of the present prospective randomized study was to evaluate the efficacy of lidocaine hydrochloride gel compared to dimethyl sulfoxide (DMSO) with lidocaine in rigid cystoscopy. MATERIALS AND METHODS Male patients requiring 17F rigid cystoscopy were eligible for inclusion in this study. A total of 140 patients were divided into two groups: group 1 (n=70) received approximately 11 mL of 2% lidocaine gel intraurethrally, while in group 2 (n=70) approximately 10 mL of 40% DMSO with an amount of lidocaine equal to that in the lidocaine gel was smeared around the scope and external urethral meatus. A penile clamp was placed for 15 minutes and 5 minutes in group 1 and group 2, respectively. Immediately after cystoscopic examination pain was scored on a 10-cm visual analog scale. RESULTS The mean pain scores after the procedure for group 1 and group 2 were 3.9+/-1.1 and 2.1+/-1.0, respectively. The pain scores were significantly lower for group 2 than for group 1 (P=0.015). No patients needed additional anesthetic agents or sedatives due to insufficient analgesia, and there were no serious side effects in either group. CONCLUSIONS Our study has shown that DMSO with lidocaine gel causes significantly less delivery discomfort in the male urethra than lidocaine hydrochloride gel. The advantages of DMSO with lidocaine are the mixture takes less time to act and had lower pain scores.


International Urology and Nephrology | 2007

Iliac artery stenosis as a cause of posttransplant renal failure and claudication

Kairgeldy Aikimbaev; Erol Akgul; Erol Aksungur; Erkan Demir; U. Erken

Iliac artery stenosis (IAS) is a rare complication after renal transplantation. We demonstrate a case of ipsilateral external IAS proximally to anastomosis in a kidney recipient, which manifested with renal failure and claudication, and was successfully treated with endovascular stent placement.


Saudi Journal of Kidney Diseases and Transplantation | 2014

Comparison between spousal donor transplantation treated with anti-thymocyte globulin induction therapy and, living related donor transplantation treated with standard immunosuppression.

Erkan Demir; Saime Paydas; U. Erken

The worldwide shortage of organs available for transplantation has led to the use of living-unrelated kidney donors. In this context, spouses represent an important source of organ donors. We compared the allograft outcomes of spousal donor transplantation (SDT) with anti-thymocyte globulin (ATG) induction therapy and living related donor transplantation (LRDT) with triple immonosuppression and basiliximab, in addition. Among the 335 living and deceased donor kidney transplantations performed between April 2001 and June 2010, there were 274 living donor kidney transplantations including 34 SDT and 240 LRDT. The minimum follow-up period was 36 months. All recipients of SDT received ATG (1.5 mg/kg) induction therapy, which was stopped five to seven days after surgery. Maintenance immunosuppression included tacrolimus (TAC), mycophenolate mofetil (MMF) and prednisolone. LRDT recipients received triple immunosuppressive protocol consisting of cyclosporine or TAC, MMF and prednisolone, in addition to basiliximab. There was a significant difference between the two groups in recipient age, while pre-operative duration on dialysis, recipient sex and donor age and sex were not significantly different. There was also a significant difference between the two groups in the number of human leukocyte antigen (HLA) mismatches. The 1-, 3- and 5-year graft survival rates of SDT were 94.1%, 88.2% and 79.4%, respectively, and the frequency of acute rejection episodes was 5.8% (two cases). The 1-, 3- and 5-year graft survival rates of LRDT were 95.8%, 91.6% and 83.3%, respectively, with the frequency of acute rejection being 16.2%. The graft survival rates of SDT were as good as LRDT, while the acute rejection rates in SDT were lower than in LRDT, although the difference was not statistically different (P = 0.13).


International Journal of Dermatology | 2008

Dermatomycosis in renal transplant recipients in Adana, Turkey

Esra Polat; Erkan Demir; Macit Ilkit; I. Atilla Aridogan; Fatma Polat; U. Erken

References 1 Hershkowitz I, Horowitz D, Lamb ME. Trends in children’s disclosure of abuse in Israel: a national study. Child Abuse Negl 2005; 29 : 1203–1214. 2 Spencer MJ, Dunklee P. Sexual abuse of boys. Pediatrics 1986; 78 : 133–138. 3 Ellerstein NS, Canavan JW. Sexual abuse of boys. Am J Dis Child 1980; 134 : 255–257. 4 Nieuwenhuis RF, van Doornum GJ, Mulder PG, et al . Importance of herpes simplex virus type-1 (HSV-1) in primary genital herpes. Acta Derm Venereol 2006; 86 : 129–134. 5 Samra Z, Scherf E, Dan M. Herpes simplex virus type 1 is the prevailing cause of genital herpes in the Tel Aviv area, Israel. Sex Transm Dis 2003; 30 : 794–796. 6 Isacsohn M, Smetana Z, Rones ZZ, et al . A seroepidemiological study of herpes virus type 1 and 2 infection in Israel. J Clin Virol 2002; 24 : 85–92. 7 Hornor G. Ano-genital herpes in children. J Pediatr Health Care 2006; 20 : 106–114. 8 Neinstein LS, Goldenring J, Carpenter S. Nonsexual transmission of sexually transmitted diseases: an infrequent occurrence. Pediatrics 1984; 74 : 67–76. 9 Ingram DL, Everett VD, Lyna PR, et al . Epidemiology of adult sexually transmitted disease agents in children being evaluated for sexual abuse. Pediatr Infect Dis J 1992; 11 : 945–950. 10 Milas J, Ropac D, Mulic R, et al . Hepatitis B in the family. Eur J Epidemiol 2000; 16 : 203–208.


Transplantation Proceedings | 2006

Efficacy and Safety of Vardenafil in Renal Transplant Recipients With Erectile Dysfunction

Erkan Demir; Mustafa Balal; Semra Paydas; Yasar Sertdemir; U. Erken


International Urology and Nephrology | 2001

Morbidity of flank incision in 100 renal donors.

Yildirim Bayazit; I. Atilla Aridogan; Zuhtu Tansug; İlker Ünsal; U. Erken


Transplantation Proceedings | 2006

Effects of Pentoxifylline on the Cytokines That May Play a Role in Rejection and Resistive Index in Renal Transplant Recipients

Erkan Demir; Semra Paydas; Mustafa Balal; Cemal Kurt; Yasar Sertdemir; U. Erken

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Erkan Demir

Military Medical Academy

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Erkan Demir

Military Medical Academy

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I. Atilla Aridogan

Hillel Yaffe Medical Center

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