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Featured researches published by Ünal Yasavul.


American Journal of Hypertension | 1999

Effects of angiotensin converting enzyme and angiotensin II receptor inhibition on impaired fibrinolysis in systemic hypertension

Yunus Erdem; Celalettin Usalan; Ibrahim C. Haznedaroglu; Bulent Altun; Mustafa Arici; Ünal Yasavul; Cetin Turgan; Sali Caglar

Abnormalities in fibrinolysis have been reported in hypertension. Angiotensin converting enzyme (ACE) inhibitors have been shown to improve altered fibrinolytic balance in hypertensive patients. It has not been documented, however, whether this is due to a decrease in angiotensin II (Ang-II) generation or is a consequence of elevated local levels of bradykinin. Accordingly, the aim of this study was to determine the effects of an ACE inhibitor (perindopril) and an Ang-II receptor antagonist (losartan) on fibrinolytic kinetics. We have examined the serum levels of the plasminogen activator inhibitor type-1 (PAI-1) antigen and activity, tissue plasminogen activator (t-PA) antigen and activity, soluble thrombomodulin (sTM), and tissue factor pathway inhibitor (TFPI) before and after reaching the target blood pressure (<140/90 mm Hg) in 13 hypertensive patients receiving perindopril (mean age 40+/-11 years, 6 women, 7 men) and in 12 patients receiving losartan (mean age 38+/-9 years, 6 women, 6 men). We also compared the baseline fibrinolytic activity of hypertensive patients with that of 12 normotensive control persons (mean age 40+/-9 years, 6 women, 6 men). The mean basal plasma levels of PAI-1 antigen, PAI-1 activity, and sTM were significantly higher in the hypertensive patients than in normal controls (P<.005). The values of other analytes were similar in both groups. Increased plasma levels of PAI-1 antigen, PAI-1 activity, and sTM were reduced in patients after they were given perindopril and losartan (P<.005); the reductions in losartan-receiving group were more pronounced (P<.05). There were no significant effects on the plasma levels of t-PA antigen, t-PA activity, and TFPI in patients receiving the two therapeutic regimens (P>.05). In conclusion, chronic hypertension is associated with hypofibrinolysis. The beneficial effect of ACE inhibitors on fibrinolysis seems to be related to the blockade of Ang-II, and increased kinin activity does not appear to play a major role.


Transplantation Proceedings | 2008

Preoperative Evaluation of Hilar Vessel Anatomy With 3-D Computerized Tomography in Living Kidney Donors

S.T. Tombul; Fazil Tuncay Aki; M. Gunay; Kubilay Inci; T. Hazırolan; M. Karcaaltincaba; I. Erkan; Aysin Bakkaloglu; Ünal Yasavul; Mehmet Bakkaloglu

OBJECTIVES Digital subtract angiography is the gold standard for anatomic assessment of renal vasculature for living renal donors. However, multidetector-row computerized tomography (MDCT) is less invasive than digital subtract angiography and provides information of kidney stones and other intra-abdominal organs. In this study, preoperative MDCT angiography results were compared with the peroperative findings to evaluate the accuracy of MDCT for the evaluation of renal anatomy. METHODS From December 2002 to May 2007, all 60 consecutive living kidney donors were evaluated with MDCT angiography preoperatively. We reported the number and origin of renal arteries, presence of early branching arteries, and any intrinsic renal artery disease. Renal venous anatomy was evaluated for the presence of accessory, retroaortic, and circumaortic veins using venous phase axial images. The calyces and ureters were assessed with delayed topograms. The results of the MDCT angiography were compared with the peroperative findings. RESULTS A total of 67 renal arteries were seen peroperatively in 60 renal units. Preoperative MDCT angiography detected 64 of them. The two arteries not detected by MDCT had diameters less than 3 mm. Anatomic variations were present in nine veins, five of which were detected by CT angiography. Sensitivity of MDCT angiography for arteries and veins was 95% and 93%, respectively. Positive predictive values were 100% for both arteries and veins. CONCLUSION MDCT angiography offers a less invasive, rapid, and accurate preoperative investigation modality for vascular anatomy in living kidney donors. It also provides sufficient information about extrarenal anatomy important for donor surgery.


International Urology and Nephrology | 2003

Radiocontrast-induced nephrotoxicity and urinary alpha-glutathione S-transferase levels: Effect of amlodipine administration

Mustafa Arici; Celalettin Usalan; Bulent Altun; Yunus Erdem; Ünal Yasavul; Cetin Turgan; Sirri Kes; Şali Çağlar

Aims: The exact pathogenesis and prophylaxis concerning radiocontrast-induced nephrotoxicity (RCIN) was unclear. Short-acting calcium antagonists were used to prevent RCIN. This study was designed to evaluate the role of a long-acting calcium antagonist (amlodipine) administration by determining serum creatinine (SCre) levels and 24 hour urinary excretion rates of glutathione S-transferase alpha (GST-α) which has a selective localization only to proximal tubular epithelium.Methods: In a prospective trial, 29 outpatients (19 M, 10 F) undergoing coronary angiography were randomized and either amlodipine 10 mg/day (n = 15) or placebo (n = 14) were administered prior to angiography and continued thereafter. All patients had normal basal renal function and none of them had any risk factor for RCIN. A low osmolar, nonionic contrast media (iopamidol 76%) was administered to all patients. Creatinine clearance (CCre), SCre and 24-hour urinary GST-α levels were measured before, 24 hours and 7 days after angiography.Results: SCre and 24 hour urinary GST-α values increased on 24th hour following the angiography in both groups (p < 0.017 and 0.001, respectively). Pretreatment with amlodipine created no difference in both variables (p > 0.05).Conclusions: A reversible tubular dysfunction occurs following radiocontrast administration which was manifested by an increase in urinary GST-α excretion rates. Pretreatment with a long acting calcium antagonist amlodipine has no effect on the course of enzyme excretion and alteration observed in SCre


American Journal of Infection Control | 2003

THE BOOSTER PHENOMENON IN 2-STEP TUBERCULIN SKIN TESTING OF PATIENTS RECEIVING LONG TERM HEMODIALYSIS

Ali Akcay; Yunus Erdem; Bulent Altun; Celalettin Usalan; Erhan Agca; Ünal Yasavul; Cetin Turgan; Sali Caglar

BACKGROUND Tuberculosis remains a significant health problem for patients receiving long-term hemodialysis (HD). The tuberculin skin test (TST) is an important method for detecting Mycobacterium tuberculosis infection. This study examined the significance and frequency of the booster phenomenon in serial TST of HD patients. METHOD Fifty-three outpatients in a hospital-based HD center in Turkey were screened for tuberculosis with the TST between August and October 1999. To determine the frequency of booster phenomenon, patients with less than 10 mm indurations to the initial TST were given a second test 7 days later. RESULTS Nineteen (35.8%) of 53 patients had a significant tuberculin reaction (> or = 10 mm) on the initial TST. The booster effect was detected in 10 (29.4%) of 34 patients who had a negative reaction (< 10 mm) to the initial test. Overall, 29 (54.7%) patients showed a significant reaction on both tests. CONCLUSIONS These results showed significant rates of TST positivity and the booster effect in this HD center.


Nephron | 1989

The expanding spectrum of a disease. Behçet's disease associated with amyloidosis.

Ilgar Tasdemir; Bulent Sivri; Cetin Turgan; Salih Emri; Ünal Yasavul; Sali Caglar

In this report, we present a series of 6 patients with Behçets disease (BD) associated with amyloidosis whose illnesses date back at least 4 years. In all the cases, nephrotic syndrome heralded the onset of amyloidosis, which was diagnosed by percutaneous kidney biopsies. After the diagnosis of amyloidosis, all subjects received colchicine, and steroids were discontinued. Three patients have benefited from treatment. It was suggested that amyloidosis may be an intrinsic feature of BD or that the suppurative lesions may play a role in the accumulation of amyloid in the tissues. The literature was reviewed and discussed.


Transplantation Proceedings | 2008

Utility of the Doppler ultrasound parameter, resistive index, in renal transplant histopathology.

Alper Kirkpantur; Rahmi Yilmaz; D. Ertoy Baydar; Tuncay Aki; Barbaros Cil; Mustafa Arici; Bulent Altun; Yunus Erdem; I. Erkan; Mehmet Bakkaloglu; Ünal Yasavul; Cetin Turgan

BACKGROUND Doppler ultrasonography is routinely used by many clinicians during long-term follow-up to identify high-risk patients without diagnosing the exact cause of graft dysfunction. Despite a number of studies showing a correlation between intrarenal resistive index (RI) and renal function in patients with kidney diseases, correlations between RI and renal histopathologic characteristics have not been sufficiently evaluated in renal transplant recipients. The aim of this study was to examine this relationship in grafted kidneys. PATIENTS AND METHODS The intrarenal RI was retrospectively compared with biopsy findings in 28 kidney recipients. All renal biopsy specimens were reviewed by light microscopy and immunofluorescence staining. For glomerulosclerosis, we considered the percentage of glomeruli showing this change; for interstitial fibrosis/tubular atrophy and interstitial infiltration, we graded abnormalities according to the methods of Kliem et al (Kidney Int 49:666, 1996). RESULTS The percentage of globally sclerosed glomeruli was significantly greater among patients with RI values higher than 0.75 than below this level (23% vs 47%; P = .022). Patients with grade 1 interstitial fibrosis and tubular atrophy (n = 14) showed lower RI values (0.68 +/- 0.03 vs 0.74 +/- 0.06; P = .047) than those with grade 3 fibrosis (n = 12). Similarly, lower RI values (0.66 +/- 0.02 vs 0.73 +/- 0.05; P = .014) were observed among patients with grade 1 (n = 13) compared with grade 3 interstitial infiltration (n = 13). CONCLUSION RI seemed to provide a prognostic marker for the graft rather than yielding an exact diagnosis of renal graft dysfunction.


Nephron Clinical Practice | 2011

Daily Sodium Intake in Chronic Kidney Disease Patients during Nephrology Clinic Follow-Up: An Observational Study with 24-Hour Urine Sodium Measurement

Aysun Aybal Kutlugun; Mustafa Arici; Tolga Yildirim; Didem Turgut; Rahmi Yilmaz; Mahmut Altindal; Bulent Altun; Yunus Erdem; Ünal Yasavul; Cetin Turgan

Objective: To determine daily sodium intake in ‘real practice’ in a large group of chronic kidney disease (CKD) patients who were under regular follow-up in a nephrology clinic. Methods: A total of 373 consecutive outpatients with CKD stages 1–5 (not on dialysis; men: 52.3%, mean age: 51.6 ± 15.4 years) were included in the study. All patients had at least 3 or more nephrology visits and received information on reducing their sodium intake. Data for systolic and diastolic blood pressure, number of antihypertensive medications and 2 consecutive 24-hour urinary sodium levels were obtained from the patients’ medical records. Results: The mean 24-hour urinary sodium levels of 2 consecutive urine samples were 168.8 ± 70.3 and 169.3 ± 67.4 mEq/day (p > 0.05). Only 14.7% of the patients had a sodium excretion <100 mmol/day. There was no difference in daily sodium intake from stages 1 to 4, but it was significantly lower in stage 5 (126.6 ± 60.5 mEq/day, p < 0.05). No relation was found between 24-hour urinary sodium output, number of antihypertensives or thiazide use. Conclusions: This study showed that almost 85% of CKD patients under regular nephrologic care were consuming more sodium than the recommended level. More robust measures should be devised to increase patient and physician compliance with reducing sodium intake in CKD.


Clinical Transplantation | 2004

Apolipoprotein E gene polymorphism in renal transplant recipients: effects on lipid metabolism, atherosclerosis and allograft function

Serkan Kahraman; Ahmet Kiykim; Bulent Altun; Gultekin Genctoy; Mustafa Arici; Meltem Gülsün; Yunus Erdem; Ünal Yasavul; Cetin Turgan; Sali Caglar

Abstract:  Introduction:  Atherosclerosis is a serious complication and leading cause of mortality in renal transplant recipients (RTRs). Hyperlipidemia may be associated with progression of renal disease and chronic allograft dysfunction. Similarities in the pathogenesis of glomerulosclerosis and atherosclerosis have been proposed. Apolipoprotein (apo) E gene code forms three major isoforms (E2, E3, and E4) with variable effects on lipid metabolism.


Nephron | 1998

Nonrelated Living-Donor Kidney Transplantation: Medical and Ethical Aspects

Murat Colakoglu; Mujdat Yenicesu; Tekin Akpolat; Abdulgaffar Vural; Cengiz Utaş; Turgay Arinsoy; Şükrü Sindel; Emel Akoglu; Ünal Yasavul; Cetin Turgan; Şali Çağlar

Several patients with end-stage renal disease went to Bombay for renal transplantation from nonrelated living donors and then returned to Turkey for posttransplantation follow-up. The aims of this study are to evaluate the long-term results of renal transplantation from nonrelated living donors in Turkish patients with end-stage renal disease and to discuss the ethical and social aspects of nonrelated kidney donation. One hundred and twenty-seven patients (89 males, 38 females; mean age 38.1, range 17–63 years) were investigated retrospectively. None of the patients went to Bombay on our advice. All transplantations were performed between 1991 and 1995. The mean follow-up period after transplantation was 34.2 (range 1–68) months. Graft survival rates were 85, 83, and 57% after 3 months and 1 and 5 years, respectively. Patient survival rates were 94, 93, and 92% after 3 months and 1 and 5 years, respectively. Seven patients died within the first 3 months after the transplantation. Surgical problems, infections, acute rejection, ciclosporin nephrotoxicity, and hepatic problems were common complications. We conclude that medical and surgical complications occur frequently in paid kidney transplantation, but most of these complications can be prevented by adequate preoperative management, and precautionary measures should be taken to prevent commercialization of renal transplantation before the spread of emotionally related living kidney donation.


Nephron | 1990

Subclinical Adrenocortical Insufficiency in Renal Amyloidosis

Nurol Arik; Ilgar Tasdemir; Yasar Karaaslan; Ünal Yasavul; Cetin Turgan; Şali Çag¯lar

In order to investigate the functional significance of possible adrenal amyloid infiltration in patients with renal amyloidosis, we performed corticotrophin stimulation tests in 15 patients having renal amyloidosis with no clinical evidence of adrenocortical insufficiency and 12 controls. In 7 of the patients, the cortisol increments obtained during the test were found to be consistent with primary adrenal insufficiency due to possible amyloid infiltration of the adrenal cortex; in contrast, in all control subjects, adrenal responses to the test were regarded as sufficient for proper adrenal function.

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