Hearing in renal failure.
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Evoked Potentials, Auditory↗
Biomedical subjects
Vassilis Vargemezis
Publications and source records attributed to Vassilis Vargemezis.
Aortic stiffness in patients undergoing hemodialysis is positively related to antigen presenting cell-dependent T-lymphocyte reactivity.
BACKGROUND: Aortic stiffness is increased in patients undergoing hemodialysis (HD), and it is associated with an increased cardiovascular mortality. Among others, aortic stiffness has been correlated with serum markers of inflammation, indicating a role of the immune system in its pathogenesis. The aim of this study was to evaluate the impact of antigen-presenting cell-dependent T-lymphocyte reactivity on aortic stiffness in HD patients. PATIENTS AND METHODS: Twenty patients were enrolled in the study. Exclusion criteria were medications or conditions, other than HD, that are known to influence the immune response or aortic stiffness. Antigen-presenting cell-dependent T-lymphocyte reactivity was assessed by cell proliferation of peripheral blood mononuclear cells cultured with or without stimulation with Staphylococcal enterotoxin B (SEB). Cell proliferation was estimated by immunoenzymatic measurement of bromodeoxyuridine uptake. Aortic stiffness was assessed by carotid-femoral pulse wave velocity (PWV) measurement. RESULTS: Linear regression analysis revealed a strong positive relation between carotid-femoral PWV and antigen-presenting cell-dependent T-lymphocyte reactivity, when SEB at concentrations of 1 ng/mL or 10 ng/mL was used as stimulant. CONCLUSION: The present study confirms that aortic stiffness in HD patients is positively related to antigen-presenting cell-dependent T-lymphocyte reactivity. The greater the ability of the immune system to react to a monocyte-dependent stimulant and, consequently, to provoke an inflammatory response, the greater the stiffness of the aorta. This is in agreement with the observation that aortic stiffness in HD patients is positively related to various serum inflammation markers.
Adult↗
The efficacy and safety of once-weekly and once-fortnightly subcutaneous epoetin beta in peritoneal dialysis patients with chronic renal anaemia.
BACKGROUND: Reducing the dosage frequency of subcutaneous epoetin in peritoneal dialysis (PD) patients is convenient and should improve patient satisfaction and, possibly, compliance. We investigated if a weekly dosage of epoetin beta in PD patients safely maintained haemoglobin (Hb) concentrations equivalent to those obtained with previous twice- or thrice-weekly administration. In addition, we investigated if a fortnightly dosage of epoetin beta was safe and as effective as previous weekly administration. METHODS: After a 4 week run-in period, PD patients were switched to either weekly or fortnightly epoetin beta administration, depending on their previous treatment schedules, for 25 weeks. RESULTS: The per-protocol cohort included 128 patients, of whom 54 received epoetin beta once weekly and 74 once fortnightly. The mean change in Hb concentration from baseline over weeks 13-25 and the 90% confidence intervals (CIs) remained within the target range (10-12 g/dl) and specified equivalence (+/-0.75 g/dl) limits in the weekly (-0.34 g/dl; 90% CI: -0.14 to -0.54 g/dl) and fortnightly (-0.39 g/dl; 90% CI: -0.24 to -0.55 g/dl) cohorts. The mean change from baseline in the epoetin beta dose was 1.4 IU/kg/week (90% CI: -3.8 to 6.6 IU/kg/week; 2%) in the weekly cohort and 4.4 IU/kg/week (90% CI: 1.7-7.2 IU/kg/week; 13%) in the fortnightly cohort. Both treatment regimens were well tolerated. CONCLUSIONS: In stable PD patients switched from twice- or thrice-weekly to weekly epoetin beta treatment, Hb concentrations could be maintained within the specified range over 25 weeks without significant change in their mean epoetin beta doses. In patients switched from weekly to fortnightly treatment, Hb concentrations could also be maintained over 25 weeks. There was a small increase in the mean dose during this period, but >/=50% of patients could be maintained without dose increase. Reducing dosage frequency may improve compliance in PD patients who self-administer their epoetin.
Adult↗
Peritoneal catheters and related infections.
Catheter related infectious complications (exit-site infections, tunnel infections, and peritonitis) remain the major reasons for technique failure during the three decades since, continuous ambulatory peritoneal dialysis (CAPD) treatment has been first established. Despite improvements in catheter's survival rates, catheter related complications result in an increase in the cumulative patients' morbidity and often leading to the catheter removal. The ideal catheter provides reliable and rapid dialysate flow rates without leaks or infections. Among several types, the double-cuff straight Tenckhoff catheter, developed in 1968, is still the most widely used, although its use is decreasing in favour of swanneck catheters. Although there are only few well-designed trials comparing catheters and catheters related infectious complications, controlling for all other important variables, no difference in these complications among the main types of catheters was seen. The single cuff catheters have been associated with a shorter survival rate and time to the first peritonitis episode than the double-cuff catheters. Also exit-site infections were found to be more frequent and significantly more resistant to treatment with single-cuff compared to double-cuff ones. Finally, better results have been reported with the latest developed presternal peritoneal dialysis catheter both regarding survival rates and exit-site infection and peritonitis rates. Recently a renewed interest in continuous flow peritoneal dialysis stimulated inventions of imaginative, double-lumen catheters since a suitable peritoneal access is a sine qua non condition for the development of this new technique of peritoneal dialysis.
Catheterization↗
The value of serum antilipoarabinomannan antibody detection in the diagnosis of latent tuberculosis in hemodialysis patients.
BACKGROUND: The risk for tuberculosis (TB) reactivation in hemodialysis (HD) patients is increased, and screening for latent TB is recommended. The tuberculin skin test (TST) is inaccurate because of the high incidence of anergy in skin testing in HD patients and its inability to differentiate latent from eradicated TB infection. In this study, use of serum antilipoarabinomannan (anti-LAM) antibody detection for the diagnosis of latent TB in a dialysis population was evaluated. METHODS: Seventy-four HD patients never treated for TB composed the first group. Forty-eight healthy volunteers never treated for TB served as controls. Twenty-one TST-positive renal transplant candidates on dialysis therapy who had completed preventive anti-TB treatment formed a third group. The TST (using the Mantoux method) and anti-LAM test (using an immunochromatographic assay) were performed in all subjects participating in the study. RESULTS: In the first group, a strong association was detected between results of the TST and anti-LAM test (P < 0.0001, chi-square test). A similar association was found in the second group. In the group of HD patients treated for TB, a positive TST result and negative anti-LAM test result was a constant finding. CONCLUSION: The association between the TST and anti-LAM test in HD patients suggests that the anti-LAM test could be a useful tool for diagnosing latent TB. The absence of anti-LAM antibodies in anti-TB-treated HD patients suggests that immune response to lipoarabinomannan lacks long-lasting memory. A negative anti-LAM test result might reflect the absence of latent TB, even in patients with a positive TST result.
Adult↗
The value of computed tomography-derived coronary artery calcification score in coronary artery disease detection in asymptomatic hemodialysis patients.
BACKGROUND: We evaluated the value of coronary artery calcification (CAC) score in coronary artery disease (CAD) detection in asymptomatic hemodialysis (HD) patients by evaluating the association among CAC score, exercise electrocardiography (EECG), and Thallium-201 dipyridamole scintigraphy. Correlation between aortic pulse wave velocity (PWV) and CAC score was also evaluated. METHODS: CAC score was assessed with conventional computed tomography in 40 patients. Thirty patients completed EECG and 25; those with a positive CAC score and/or a positive EECG performed Thallium dipyridamole scintigraphy. Carotid-femoral PWV was assessed in all patients. RESULTS: There was no association among CAC score and EECG or Thallium dipyridamole scintigraphy. In contrast, CAC score was correlated with aortic PWV. CONCLUSION: The previous results question the role of CAC score in the detection of CAD in asymptomatic HD patients. The correlation between CAC score and aortic PWV raises the possibility that CAC score represents more an indicator of coronary artery medial wall calcification than a marker of CAD.
Age Distribution↗