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Biomedical subjects

I C Haznedaroglu

Publications and source records attributed to I C Haznedaroglu.

36 records · Page 2Linked to original sources
PubMed1999

Determinants of soluble CD23 antigen levels in hemodialysis patients: effect of 1.25 dihydroxyvitamin D3 and recombinant human erythropoietin treatment.

BACKGROUND: The immunodeficiency of end-stage renal disease (ESRD) paradoxically coexists with T cell and monocyte activation. In spite of well known defective antibody responses in ESRD, the functional status of B cells in the immune system dysregulation of uremia is still controversial. Soluble CD23 (sCD23) antigen is a recently identified B cell activation marker and is also involved in T cell activation process. Effects of parathyroid hormone (PTH), red blood cells and ferritin on T and B cell functions have been shown both in vivo and in vitro. PATIENTS AND METHODS: In this study, serum levels of sCD23 in hemodialysis patients were determined to evaluate the functional status of B cells and possible linkages between this cytokine and PTH levels, ferritin levels, red blood cell counts were investigated. RESULTS: Serum sCD23 levels were significantly elevated in hemodialysis patients relative to healthy controls (12.5+/-8.4 micro/l vs. 2.4+/-1.1 micro/l, p<0.001). Serum sCD23 levels were negatively correlated with red blood cell count (r = -0.61, p = 0.009) and serum PTH levels (r = -0.62, p = 0.008), while positively correlated with serum ferritin levels (r = 0.63, p = 0.007) in hemodialysis patients. We also investigated the immunumodulator effects of 1.25 dihydroxyvitamin D3 (1.25OHD3) and recombinant human erythropoietin (rHu-Epo) treatment in hemodialysis patients. 1.25OHD3 treatment for eight weeks did not change serum sCD23 levels in hemodialysis patients (n = 8). On the other side, rHu-Epo administration for 16 weeks led to a decrease in serum sCD23 levels (17.7+/-8.6 microg/l vs. 9.8+/-3.5 microg/l, p = 0.007) in these patients (n = 9). CONCLUSION: These results suggests that similar to T cells, B cells are activated in uremia and the degree of this activation is correlated with red blood cell count, serum parathyroid hormone levels and iron status of the hemodialysis patients. Moreover, B cell activation could be altered by recombinant human erythropoietin therapy in hemodialysis patients.

Adult↗
PubMed1998

Activation of blood coagulation in patients with mitral stenosis and sinus rhythm.

The aim of this study was to assess whether there is blood coagulation activation in patients with mitral stenosis (MS) and sinus rhythm (SR) and to investigate the value of left atrial spontaneous echo contrast (LASEC) as a predictive sign of increased coagulation activity. Using thrombin-antithrombin III complexes and prothrombin fragment 1+2 as in vivo hemostatic markers, we concluded that there is a hypercoagulable state in patients with MS and SR when LASEC is present.

Adult↗
PubMed1998

Thrombopoietin, interleukin-6, and P-selectin at diagnosis and during post-steroid recovery period of patients with autoimmune thrombocytopenic purpura.

Plasma concentrations of the most potent megakaryocytopoietic cytokines, thrombopoietin (TPO) and interleukin-6 (IL-6), and the platelet activation marker P-selectin were evaluated in 24 patients with autoimmune thrombocytopenic purpura (ATP) who responded to conventional steroid treatment, at diagnosis and after steroid-induced recovery. Baseline TPO concentration (median [interquartile range]=0 [17.52] pg/ml) was significantly decreased and IL-6 (38 [19.75] pg/ml) and P-selectin (485 [393.75] ng/ml) were significantly elevated compared with healthy subjects (100 [68] pg/ml, 8 [7] pg/ml and 166 [69] ng/ml, respectively). Following steroid treatment, all values approached normal, i.e., TPO (20 [18.75] pg/ml) was increased and IL-6 (19.5 [13] pg/ml) and P-selectin (248 [172.5] ng/ml) were decreased, significantly. The decrease of TPO in ATP is suggested to occur due to increased megakaryocyte mass and, consequently, TPO clearance. The non-lineage-specific cytokine IL-6 may be elevated to compensate for megakaryocytopoiesis/thrombopoiesis. The elevation of P-selectin may reflect compensatory platelet hyperactivation; however, this molecule also might be a marker of platelet destruction.

Adult↗
PubMed1998

P-selectin as a circulating molecular marker in rheumatoid arthritis with thrombocytosis.

OBJECTIVE: To compare plasma concentrations of soluble P-selectin (sP-selectin) in patients with rheumatoid arthritis (RA) and thrombocytosis with those with RA with normal platelet counts and healthy controls, and to explore the relationship between clinical and serological measures of disease activity. METHODS: Nineteen patients with RA with marked thrombocytosis, 20 with normal platelet counts, and 24 controls were enrolled. Ritchie articular index and morning stiffness were recorded as clinical markers of disease activity. Blood samples were collected for platelet count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and plasma sP-selectin determinations. Correlations between sP-selectin and clinical and serological markers of disease activity were noted. RESULTS: Patients with RA and thrombocytosis compared to patients with normal platelet counts showed evidence of more active disease when ESR, CRP, morning stiffness, and Ritchie articular index were considered. The thrombocyte count in patients with RA with marked thrombocytosis revealed a positive correlation with CRP and Ritchie articular score. Plasma sP-selectin levels were found to be significantly higher in patients with RA compared to controls. sP-selectin levels were significantly higher in patients with RA with thrombocytosis compared to those with normal platelet counts, and positive correlations were observed between plasma sP-selectin levels and Ritchie index, morning stiffness, and thrombocyte counts in those patients. CONCLUSION: Elevated plasma sP-selectin levels in RA could indicate the presence of a continuous underlying inflammatory stimulus. In addition, the augmented increase in patients with RA and thrombocytosis and its correlation with clinical activity may imply the cytokine-adhesion molecule interaction mediates the chronic inflammation of RA.

Adult↗
PubMed1998

Circulating thrombopoietin and interleukin-6 in newly diagnosed autoimmune versus aplastic thrombocytopenia.

Circulating thrombopoietin and interleukin-6 concentrations were investigated in two different settings of thrombocytopenia. Twenty patients with autoimmune thrombocytopenic purpura (ATP), 12 patients with aplastic anemia (AA) and 15 healthy subjects were studied. Thrombopoietin was significantly increased in AA and deficient in ATP. Interleukin-6 was significantly increased in ATP, compared to both other groups.

Adult↗
PubMed1996

Impaired haemostatic kinetics and endothelial function in Behçet's disease.

OBJECTIVES: This study was planned to explore the alterations of endothelial functions in the prethrombotic state of Behçet's disease (BD) patients. DESIGN: Plasma levels of endothelial secretory markers, in vivo molecular haemostatic and fibrinolytic parameters were cross-sectionally determined in the study group. SETTING AND SUBJECTS: In our tertiary referral centre, 30 (13 men, 17 women) BD patients, mean age 31 +/- 7 years, and 15 (eight men, seven women) healthy volunteers, mean age 26 +/- 9 years, were eligible for inclusion in the study after obtaining their written consents. INTERVENTIONS: All plasma samples for the assays of haemostatic parameters were obtained before and after an endothelial stimulant, desmopressin acetate (DDAVP). RESULTS: We have shown that in the procoagulant phase of BD patients: (1) basal thrombomodulin concentrations are increased and could not be provoked by DDAVP infusion; (2) both thromboxane B2 and 6-keto prostaglandin F1 alpha increments occur concurrently; (3) in vivo coagulation markers are elevated and raised plasmin-alpha 2 antiplasmin complex indicates a subclinical concomitant fibrinolysis; (4) the fibrinolytic process is conveyed in a somewhat complex manner in which plasminogen activator binding kinetics might be also altered. CONCLUSIONS: Endothelial cell injury, augmented thrombotic risk with compensatory excessive fibrinolysis and alterations in endothelial cell receptor-fibrinolytic marker relations might take place in the pathogenesis and thereby modulate the natural course of haemostatic processes of BD.

Adult↗
PubMed1996

Coagulation, fibrinolysis and fibrinolysis inhibitors in haemodialysis patients: contribution of arteriovenous fistula.

BACKGROUND: End-stage renal disease (ESRD) patients, not uncommonly, might exhibit thrombotic complications, as well as they may present with a bleeding diathesis. Changes in vessel wall and/or blood flow in native arteriovenous fistula (AVF) might also augment these disarrangements, as vascular endothelium is predominantly involved in the regulation of haemostatic pathways. OBJECTIVE: This study was designed to evaluate the state of coagulation and fibrinolysis and the role of AVF on haemostatic defects, in ESRD patients on maintenance haemodialysis. METHODS: Plasma samples for prothrombin fragment 1+2, thrombin-antithrombin III complex, plasmin-alpha2 antiplasmin complex, tissue type plasminogen activator antigen, urokinase type plasminogen activator antigen, u-PA activity, plasminogen activity, alpha2-antiplasmin and alpha2-macroglobulin assays were obtained from AVF and contralateral large veins of ESRD patients and from peripheral veins of the control group. RESULTS: Our results indicate a predominant thrombotic state as evidenced by activated coagulation markers and enhanced fibrinolysis in systemic circulation of ESRD patients. However the most novel finding is the probable contribution of AVF on haemostatic activation, as proven by the statistically different and positively correlated concentrations of both coagulation, fibrinolysis, and fibrinolysis inhibitors in AVF when compared to the levels in peripheral venous circulation. CONCLUSION: In addition to systemic derangements of haemostasis in ESRD patients, AVF individually might have a substantial role in the modulation of coagulation and fibrinolytic cascade.

Adult↗
PubMed1995

Effects of ACE inhibition on left ventricular dimensions and haemodynamics in systemic hypertension: a radionuclide and echocardiographic study.

The aim of this study was to assess the effects of Angiotensin Converting Enzyme (ACE) inhibition on cardiac systolic and diastolic parameters and left ventricular muscle mass in hypertensive patients. For this purpose 30 patients (22 female and eight male) with mild to moderate essential hypertension, aged 47 +/- 2 years, were treated with enalapril maleate (MK 421, an ACE inhibitor) for six weeks. They underwent M-mode and Doppler echocardiography and radionuclide ventriculography at the beginning and after six weeks of enalapril treatment. In this study all patients treated with the ACE inhibitor enalapril responded with a significant decrease in mean arterial pressure (p < 0.001). A significant reduction in left ventricle and mass index were shown after six weeks of treatment with enalapril (p < 0.01). Total peripheral resistance and end-systolic stress decreased in the same time course (p < 0.001). Ejection fraction increased in both examinations after six weeks of therapy with enalapril, but this increase was not statistically significant. In radionuclide examinations, time to peak filling rate decreased significantly after six weeks of enalapril therapy (p < 0.02). Despite these improvements in cardiac systolic and diastolic parameters, cardiac output and stroke volume decreased slightly after enalapril treatment. We concluded that enalapril improves diastolic and systolic parameters in LV function but causes slight decreases in cardiac output and stroke volume in addition to lowering blood pressure.

Echocardiography, Doppler↗
PubMedDate not supplied

Enhanced expression of the local haematopoietic bone marrow renin-angiotensin system in polycythemia rubra vera.

Local bone marrow (BM) renin-angiotensin system (RAS) affects physiological and pathological haematopoiesis, including erythropoiesis. In this study, quantitative expression of the messenger RNAs of the major RAS components--angiotensin-converting enzyme (CD143), renin and angiotensinogen--were measured in BM samples by quantitative real-time polymerase chain reaction, to evaluate the activity of local BM RAS in polycythemia rubra vera (PV) in comparison with normal erythropoiesis. The presence of CD143 was also investigated in the same BM samples by flow cytometry. Increased local synthesis of the major RAS components has been identified by demonstrating corresponding mRNAs in the BM of the patients with PV. Our findings indicate up-regulation of local BM RAS, together with down-regulation of the cell surface angiotensin-converting enzyme receptors, in the autonomous neoplastic clonal erythropoiesis of PV.

Adult↗
PubMedDate not supplied

Interactions of nitric oxide and superoxide dismutase in Behçet's disease.

OBJECTIVE: Nitric oxide (NO) is produced in increased amounts in inflammatory conditions and may cause tissue injury by reacting with superoxide to yield peroxynitrite, a powerful toxin. Superoxide dismutase (SOD) scavenges superoxide and inhibits the formation of peroxynitrite, thereby suppressing the resulting injury and regulating the bioavailability of NO. We conducted a study to assess serum NO and SOD in patients with Behçet's disease (BD) and correlate their levels with disease activity. METHODS: Serum NO concentrations and SOD activities were determined in 25 BD patients (mean age: 36 years; male/female: 13/12) and in 15 healthy controls. BD patients were allocated into two groups according to disease activity (active/inactive: 11/14). RESULTS: In patients with active disease, NO levels were found to be significantly elevated, while SOD activities were comparable to the control group. Conversely, patients with inactive disease exhibited markedly high SOD activities and normal NO levels. Moreover, there was a positive correlation between SOD activity and NO levels in patients with inactive BD (r = 0.562, p < 0.05). CONCLUSION: We propose that NO-associated injury of tissues, particularly the endothelium, may be important in the etiopathogenesis of vasculitis in BD, and SOD may play a protective role against inflammation.

Adolescent↗
PubMedDate not supplied

Synovial fluid cytokine levels in Behçet's disease.

OBJECTIVE: To investigate the synovial fluid levels of interleukin-1 beta (IL-1 beta), tumour necrosis factor-alpha (TNF-alpha), transforming growth factor-beta (TGF-beta), IL-1 receptor antagonist (IL-1ra), soluble IL-2 receptor (sIL-2r) and IL-8 in patients with Behçet's disease (BD) and to compare them to levels in rheumatoid arthritis (RA), and osteoarthritis (OA). METHODS: The cytokine levels of BD (n = 14), RA (n = 15) and OA (n = 15) patients were assessed by enzyme-linked immunosorbent method. RESULTS: Median synovial IL-1 beta and TNF-alpha levels were higher in RA compared to BD and OA patients. IL-1 beta levels were also higher in BD than OA whereas TNF levels were similar in these two groups. IL-1ra and TGF-beta activity in BD were higher than OA but lower than RA. sIL-2r and IL-8 levels were increased in BD and RA in comparison to OA patients. CONCLUSION: The arthritis of BD is non-erosive and accordingly, its synovial fluid contains lower levels of cytokines primarily involved in cartilage destruction, namely IL-1 beta and TNF-alpha, than RA. IL-1ra and TGF might serve as protective factors against erosion in the inflamed joints. High synovial fluid levels of sIL-2r and IL-8 probably reflect a non-specific inflammatory process.

Adult↗
PubMedDate not supplied

Circulating thrombomodulin levels in familial Mediterranean fever.

Increments in circulating thrombomodulin levels reflect endothelial cell injury. Thrombomodulin can also be synthesized by several inflammatory cells including monocytes, neutrophils, and thrombomodulin itself can modulate the inflammatory response. In this study, we assessed circulating thrombomodulin concentrations in patients with familial Mediterranean fever (FMF). Twenty-five patients with FMF (F/M: 14/11) (mean age: 31.1 +/- 9.7 years) and 25 healthy controls (F/M: 13/12) (mean age: 34.6 +/- 7.0 years) were involved in the study. Thrombomodulin levels were measured by commercially available enzyme-linked immunosorbant assay (ELISA) (Immunoassay of thrombomodulin Diagnostica Stago, Asnieres-Sur-Seine, France). Twenty of the patients were in attack-free period and the remaining five had been during acute FMF attacks. Thrombomodulin levels were higher in the study group (20.9 +/- 12.1 ng/ml) than healthy controls (14.1 +/- 8.4 ng/ml) (p < 0.05). Circulating thrombomodulin levels were also higher in attack-free FMF patients (22.4 +/- 12.9 ng/ml) than controls. This study disclosed for the first time significantly higher increments in the circulating levels of thrombomodulin in FMF. This observation could be a consequence of injured endothelium and/or activated inflammatory cells.

Adult↗