Abstract Introduction: Endothelial progenitor cells (EPCs) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase enzyme activity may affect the vessel wall and have a role in development of aortic aneurysms. EPCs originate from hematopoietic stem cells and can be enumerated from peripheral blood samples by flow cytometry. In this study, we aimed to evaluate the relation of EPC number and NADPH oxidase enzyme activity in the development of thoracic aortic aneurysm (TAA). Methods: Patients with TAA (n=30) and healthy individuals without TAA (control, n=10) were included in our study. Characterization and enumeration of EPC from peripheral blood samples were performed by flow cytometry with panels including markers of EPCs (CD34/CD133/CD309/CD146/CD144). Additionally, NADPH oxidase enzyme activity (capacity) was also measured by the dihydrorhodamine 123 (DHR 123) test. Results: The enumeration of EPC with CD34+/CD146+ marker showed that the number of mean EPC/106 cells was increased in the patient group (41.5/106 cells), but not in the control group (20.50/105 cells) (P<0.01). Additionally, patients with TAA presented significantly lower NADPH oxidase activity by DHR assay than healthy controls (mean stimulation index: 60.40± 7.86 and 75.10±5.21, respectively) (P<0.01). Conclusion: Our results showed that the number of EPCs is significantly higher in aortic aneurysm patients and may have a role in disease progression. The crosstalk between NADPH oxidase enzyme capacity and EPC number may be useful as a parameter to explain the clinical progression of TAA.

PURPOSE: To analyze the effect of maintenance hemodialysis on left ventricular diastolic function in patients with end-stage renal disease. METHODS: Study population consisted of 42 patients with end-stage renal disease. Before an arteriovenous fistula was surgically created, the patients were evaluated by conventional and Doppler echocardiography and Doppler tissue imaging. Then, the patients undergoing hemodialysis treatment when the arteriovenous fistula was compleated. After the first hemodialysis session (mean 76.14 ± 11.37 days) the second echocardiographic evaluations were performed. RESULTS: Mean age was 58 ± 13 years and 21 (%50) of the patients were female. After maintenance hemodialysis treatment; peak early (E) and peak late (A) diastolic mitral inflow velocities and E/A ratio were not significantly change however the deceleration time of E wave and left atrial diameter were significantly increased. Also there was no change in the early (Em) and late (Am) diastolic myocardial velocities and Em/Am ratios of lateral and septal walls of left ventricular. E/Em ratio was decreased insignificantly. Pulmonary vein velocities and right ventricular functions are remained almost unchanged after hemodialysis treatment. DISCUSSION: The acute and long-term effect of hemodialysis on left ventricular diastolic function is unclearly. Patients with end-stage renal disease treatment with hemodialysis via arteriovenous fistula experience a variety of hemodynamic and metabolic abnormalities that predispose to alterations in left and right ventricular functions. The present study showed that left ventricular diastolic function except left atrial diameter and right ventricular functions were not significantly change, however left ventricular systolic functions were impaired after maintenance hemodialysis treatment in patients with end-stage renal disease. CONCLUSION: It has been suggested that echocardiographic parameters are useful markers for evaluation of left ventricular and right ventricular functions in patients with end-stage renal disease. However, in patients with endstage renal disease treated with hemodialysis, repeated assessment of echocardiographic examinations to observe serial changes in left and right ventricular functions are not yet well established. In this study, we showed that acute changes of volume status and electrolytes and autonomic regulation by hemodialysis session did not affect left ventricular diastolic and right ventricular functions in a relatively long term.