Biomedical subjects

Miguel Cendoroglo

Publications and source records attributed to Miguel Cendoroglo.

16 recordsLinked to original sources

PubMed2007

Serum and cellular interleukin-6 in haemodialysis patients: relationship with energy expenditure.

BACKGROUND: Inflammation is a highly prevalent condition among end-stage renal disease (ESRD) patients and it has been implicated with several metabolic derangements. Considering the harmful effect of hypermetabolism on nutritional status and clinical outcomes of ESRD patients, we aimed to investigate the relationship between proinflammatory cytokine interleukin-6 (IL-6) and energy expenditure in this population. METHODS: This cross-sectional study enrolled 80 adult haemodialysis patients for the evaluation of serum IL-6 and energy expenditure. The production of IL-6 by peripheral blood mononuclear cells (PBMCs) (spontaneous and endotoxin-stimulated production) was examined in a subgroup of 30 haemodialysis patients and in 11 healthy control subjects. IL-6 was measured by immunoenzymatic assay. The resting energy expenditure was evaluated by means of indirect calorimetry. Body composition was assessed by bioelectrical impedance analysis and skinfold thicknesses. RESULTS: Serum IL-6 [6.3 (2.2-163.5) pg/ml] correlated positively with age (R = 0.26; P = 0.02) and C-reactive protein (R = 0.31; P < 0.01). Resting energy expenditure correlated positively with lean body mass (R = 0.68; P < 0.001) and BMI (R = 0.44; P < 0.001), and negatively with Kt/V (R = -0.37; P < 0.01). In the multivariate analysis, controlling for age and lean body mass, serum IL-6 was positively associated with resting energy expenditure (n = 80; beta = 2.4; P = 0.01). The production of IL-6 by PBMCs did not reach statistically significant differences between patients and controls [spontaneous production 6541 (96-7739) pg/ml vs 3410 (50-7806) pg/ml, respectively; and stimulated production 6530 (579-7671) pg/ml vs 5304 (1527-7670) pg/ml, respectively]. IL-6 secreted by monocytes showed no association with either serum IL-6 or resting energy expenditure. CONCLUSION: Serum IL-6 was associated with an increase of energy expenditure in haemodialysis patients.

Adolescent↗

PubMed2006

The impact of traditional and non-traditional risk factors on coronary calcification in pre-dialysis patients.

BACKGROUND: Coronary heart disease (CHD) is the leading cause of death among end-stage renal disease patients. There is evidence that coronary calcification is a marker of atherosclerotic vascular disease and is predictive of cardiovascular events, especially in patients on renal replacement therapy. It has recently been suggested that CHD begins in the pre-dialysis period. However, data regarding coronary calcification in this population is scarce. This study was aimed at evaluating such coronary calcification and identifying related factors. METHODS: A total of 96 chronic kidney disease out-patients who were not on dialysis were included. Patients presenting neoplastic, infectious or inflammatory diseases were excluded. Demographic characteristics, clinical profiles, laboratory test results and multislice computed tomography scans were evaluated. RESULTS: The median age was 55 years (range 20-69 years), 67% were men and the median creatinine clearance was 37 ml/min/1.73 m(2). Coronary calcification, defined as a coronary artery calcification score (CACS) >0 Agatston units (AU), was seen in 61 patients (median 89.1 AU, range 0.37-2299.3 AU). On average, these patients were older, more often had diabetes, higher body mass indices and higher Framingham risk indices, as well as presenting higher proteinuria, intact parathyroid hormone (iPTH), blood glucose and triglyceride levels compared with those without calcification. Multiple logistic regression analysis, adjusted for age and diabetes, identified iPTH and triglyceride levels as independent determinants of calcification. Severe calcification (CACS >400 AU) was seen in 22 patients, who were also older and more frequently had a history of cardiovascular disease (CVD), as well as having higher levels of phosphorus, blood glucose and soluble Fas (sFas). Multiple logistic regression analysis, adjusted for age and diabetes, identified phosphorus and sFas levels as independent determinants of severe coronary calcification. CONCLUSION: Coronary calcification is highly prevalent in pre-dialysis patients and correlates with traditional and non-traditional risk factors for CVD.

Adolescent↗

PubMed2006

Coronary artery calcification, systemic inflammation markers and mineral metabolism in a peritoneal dialysis population.

AIMS: To assess the prevalence of coronary artery calcification (CAC) in peritoneal dialysis (PD) patients and to determine whether comorbidities such as inflammation, dyslipidemia and mineral metabolism disorders correlate with its development. METHODS: Forty-nine PD patients (45% male; median age, 52 years) were submitted to multislice computed tomography. Inflammatory markers, anti-oxidized LDL antibody, calcium-phosphate balance and lipid profiles were assessed. RESULTS: Twenty-nine patients (59.2%) presented CAC (median calcium score, 234.7 Agatston units). Patients with CAC were older than those without, more frequently presented a history of coronary artery disease or hypertension and had lower HDL cholesterol levels, as well as presenting higher levels of osteoprotegerin and LDL oxidation. The logistic regression revealed that the independent determinants of CAC were age (odds ratio = 1.12; p = 0.006) and number of prescribed anti-hypertensive drugs (odds ratio = 2.38; p = 0.048). When the population was stratified by calcium score quartile, soluble Fas levels were significantly higher in patients with severe calcification. In patients younger than 45, CAC correlated positively with phosphorus levels (r = 0.52; p = 0.04). CONCLUSION: In PD patients, CAC is highly prevalent. Our results indicate that conditions such as inflammation and mineral disturbances are associated with its development.

Adult↗

PubMed2006

Effect of microcystin on leukocyte viability and function.

Microcystin (MC) has been found in several areas of the world. In addition to its hepatotoxicity, microcystin may have an immunomodulatory effect. Considering that patients receiving hemodialysis may be chronically exposed to variable concentrations of MC, and that they present important changes in this immune response, we have assessed the effect of MC on the function of leukocytes. Polymorphonuclear leukocytes isolated from healthy volunteers (HV) and patients receiving hemodialysis (HD) were incubated with microcystin (10 microg/L) for 24h and evaluated for reactive oxygen species production (ROS), phagocytosis and apoptosis. Monocytes incubated with and without LPS (100 ng/mL) and microcystin for 24h were assessed for TNFalpha and IL-10 production. Leukocytes of HV presented an increase in apoptosis rates and leukocytes from HD exhibited a lower production of oxygen-reactive species, both spontaneously and after stimulus with S. aureus, when compared with leukocytes incubated without toxin. Monocytes presented an increase in cytokine production after stimulation by LPS in both groups, but there was no difference between the groups with and without MC that were incubated with or without LPS. Low concentrations of microcystin can induce mild changes in leukocyte function of HV and HDP, particularly in the ability to produce ROS.

Apoptosis↗

PubMed2005

Effects of uraemia and dialysis modality on polymorphonuclear cell apoptosis and function.

BACKGROUND: Previous studies have reported that incubation of polymorphonuclear cells (PMN) in uraemic plasma or with different haemodialysis membranes and peritoneal dialysis solutions increases apoptosis in this cell type. In addition, PMN harvested from uraemic patients show a reduced ability to generate superoxide in response to stimuli as well as impaired phagocytosis, chemotaxis and degranulation. The aim of the current study was to investigate the effect of uraemia and dialysis modality on apoptosis and function in freshly harvested non-incubated PMN. METHODS: Polymorphonuclear cells were harvested from 14 chronic haemodialysis (HD) patients, from 14 continuous peritoneal dialysis patients (CAPD), 28 chronic kidney disease (CKD), pre-dialysis patients and from 14 healthy subjects (Controls). In these in vivo experiments, PMN apoptosis was studied by means of flow cytometric analysis of annexin V binding to freshly isolated cells. Polymorphonuclear cell phagocytosis and production of reactive oxygen species by unstimulated or stimulated (S.aureus, fMLP, PMA) cells were also studied by flow cytometry using whole blood. RESULTS: We observed increased PMN apoptosis in CKD patients. CAPD and HD patients displayed PMN apoptosis rates similar to controls. In the HD group, PMN exhibited decreased phagocytosis rates. In contrast, phagocytosis rates in PMN from CAPD were not significantly different from controls. In the CKD and HD groups, apoptosis was inversely correlated with respiratory burst activity and phagocytosis. CONCLUSION: Our results suggest that both uraemia and treatment modality may interfere with PMN apoptosis and function. Dialysis appears to normalize the increased PMN apoptosis rates observed in CKD patients.

Adult↗

PubMed2005

Coronary calcification in hemodialysis patients: the contribution of traditional and uremia-related risk factors.

BACKGROUND: Coronary artery calcification is a common feature of atherosclerosis, occurring in 90% of angiographically significant lesions. There is recent evidence that coronary artery calcification is frequent in hemodialysis patients and it has been suggested that this increased incidence may be associated to uremia-related factors. The development and progression of coronary artery calcification is similar to osteogenesis. The aim of this study was to evaluate the relationship between coronary artery calcification, uremia-related factors, and bone histomorphometry in hemodialysis patients. METHODS: A total of 101 hemodialysis patients were assessed for biochemical markers of inflammation, oxidative stress, and bone metabolism. Subsequently, they were submitted to multislice coronary tomography (MSCT) and transiliac bone biopsy. RESULTS: The median calcium score was 116.2 (range 0 to 5547). Fifty-two percent of the patients showed moderate and severe coronary artery calcification, 20% had calcium scores greater than 1000. In univariate analysis, age (r= 0.57, P < 0.000001), osteoprotegerin (OPG) (r= 0.44, P= 0.00002), and body mass index (BMI) (r= 0.24, P= 0.01) correlated positively with calcium score. Bone trabecular volume and trabecular thickness correlated negatively with calcium score (r=-0.24, P= 0.02; r=-0.22, P= 0.03). There was a correlation of borderline significance between calcium score and C-reactive protein (CRP) (r= 0.18, P= 0.062). The multiple linear regression analysis identified OPG as the only variable independently associated with coronary artery calcification. CONCLUSION: Coronary artery calcification is highly prevalent in the hemodialysis population and is associated with older age, higher BMI, inflammation and reduced trabecular bone volume. Higher OPG is independently associated with coronary artery calcification and may represent an incomplete self-defensive response to the progression of atherosclerosis in hemodialysis patients.

Adult↗

PubMed2004

Assessment of body composition by dual energy X-ray absorptiometry, skinfold thickness and creatinine kinetics in chronic kidney disease patients.

BACKGROUND: Finding a method that can be routinely used to assess body composition with minimum error is still a challenge for those who work with chronic kidney disease (CKD) patients. This study aimed to compare the value of two surrogate techniques, skinfold thickness (SKF) and creatinine kinetics (CK) with dual energy X-ray absorptiometry (DEXA) as the reference method for measuring body fat and fat-free mass in non-dialysed CKD patients. METHODS: The body fat and fat-free mass of 50 non-dialysed CKD patients (38 male, 12 female) were measured by DEXA and compared with measurements obtained by SKF and CK. RESULTS: The mean values of body fat and fat-free mass obtained by SKF and CK differed significantly from measurements made by DEXA. The intra-class correlation coefficient (r) for body fat between SKF and DEXA (r = 0.74) and between CK and DEXA (r = 0.47) indicated a moderate degree of reproducibility. A Bland and Altman plot analysis showed a better agreement between SKF and DEXA [5.8 +/- 3.9% (-2.0 to 13.6)] than between CK and DEXA [8.8 +/- 8.8% (-8.8 to 26.4)]. Regarding fat-free mass, the intra-class correlation coefficient (r) between SKF and DEXA (r = 0.85) indicated a good degree of reproducibility, while that between SKF and CK (r = 0.57) indicated a moderate degree of reproducibility. The Bland and Altman plot analysis for fat-free mass showed that DEXA agreed better with SKF [-3.1 +/- 3.4 kg (-9.9 to 3.7)] than with CK [-5.5 +/- 6.4 kg (-18.2 to 7.3)]. CONCLUSION: Skinfold thickness seems to be the method of choice for evaluating body fat. The limitations inherent to DEXA in evaluating fat-free mass makes it difficult to designate an alternate method of choice for assessing this body compartment.

Absorptiometry, Photon↗

PubMed2004

Evaluation of the prevalence and risk factors for colonization by vancomycin-resistant Enterococcus among patients on dialysis.

BACKGROUND: Vancomycin-resistant Enterococcus (VRE) has been reported among long-term dialysis patients, although risk factors for VRE colonization are not well defined. This study aims to appraise the prevalence and risk factors for VRE colonization among patients on long-term dialysis therapy, as well as the mechanisms for dissemination of vancomycin resistance. METHODS: This is a cross-sectional survey of 320 patients on long-term dialysis therapy at 2 hospitals of the Federal University of São Paulo from June 2001 to March 2003. Fecal samples were collected from each patient once a week for 1 month. Samples with positive test results for VRE were submitted to molecular typing through automated ribotyping. RESULTS: VRE prevalence was 14.4%. There were significant associations between VRE and dialysis type (hemodialysis, P = 0.04), number of hospitalizations (P = 0.03), low hemoglobin level (P = 0.03), and leukocytosis (P = 0.05). Among samples with VRE (n = 56), 25% were Enterococcus faecium; 10.7%, Enterococcus casseliflavus; 57.1%, Enterococcus gallinarum; and 3.6%, Enterococcus faecalis. All samples isolated were sensitive to teicoplanin, except for E faecium samples, which were strongly resistant, although 9 of 14 patients with this isolate presented the same ribogroup (111-S-4). Typing of 6 samples from 8 dialysis patients with E gallinarum was performed, showing a predominant ribogroup (112-S-4). CONCLUSION: Hospital environment, hemodialysis, anemia, and leukocytosis appear to be associated with VRE colonization. These results suggest that dissemination of these bacteria among patients on long-term dialysis therapy may be taking place.

Aged↗

PubMed2004

Dialyzer membrane type and reuse practice influence polymorphonuclear leukocyte function in hemodialysis patients.

BACKGROUND: Polymorphonuclear leukocyte (PMNL) production of reactive oxygen species (ROS) has been linked to hemodialysis (HD) associated morbidity. The effect of dialyzer membrane type and reuse on PMNL function has not been clearly defined. METHODS: The present report is a cross-sectional study undertaken in a cohort of patients undergoing regular HD, at enrollment into the Hemodialysis (HEMO) Study, to study the association between patient and dialysis-related factors and PMNL function. PMNL function was assessed by measuring PMA- and N-formyl methionyl-leucyl-phenylalanine (fMLP) -induced respiratory burst, and phagocytic activity toward Staphylococcus aureus. RESULTS: PMNL from patients dialyzed with polysulphone (PS) or cuprophane (CU) membranes showed higher PMA-induced respiratory burst activity compared with those exposed to substituted cellulose (cellulose acetate, cellulose triacetate, CA/CT) membranes, regardless of dialyzer reuse. The use of bleach as a cleansing agent during reuse was associated with higher PMA-induced PMNL superoxide production, as was the use of renalin when compared to aldehydes. In a subgroup of patients using PS dialyzers, reuse itself was associated with higher fMLP-induced superoxide production. The type of bleach-germicide combination during reuse showed that use of renalin as a germicide was also associated with higher PMNL phagocytosis index. The number of years on HD correlated inversely with PMA-induced PMNL superoxide response. Weaker PMNL response to fMLP was associated with greater comorbidity and poor functional status as quantified by Index of Coexisting Diseases (ICED) and Karnofsky scores, respectively. CONCLUSION: Our results indicate that dialyzer membrane type and the reuse process influence the oxidative response of PMNL among HD patients. The implications of these observations on clinical morbidity need to be further evaluated in prospective studies.

Aged↗

PubMed2004

Effect of temporary catheter and late referral on hospitalization and mortality during the first year of hemodialysis treatment.

Late referral (LR) to dialysis therapy has been associated with poor outcomes in people with end-stage renal disease. This had been ascribed to the frequent use of temporary vascular catheters (TVCs) in LR patients. The effects of LR and TVC on the outcomes of an incident hemodialysis population (n = 101) were investigated. There was a higher incidence of vascular access infection, longer period of hospitalization, and lower survival in TVC and LR groups, compared with arteriovenous fistula and early referral (ER) groups, respectively. Late referral patients had higher number of hospitalizations than ER patients. In univariate analysis, LR (hazard ratio [HR] 10.8, P = 0.02) and albumin (HR 0.23, P < 0.0001) were associated with mortality. Late referral and body mass index were associated with the increased risk of hospitalization in univariate analysis. In multivariate analysis, LR was the only risk factor associated with hospitalization (HR 3.51, P = 0.002). In conclusion, LR was associated with increased risk of mortality and increased risk of hospitalization independently of the presence of a TVC.

Adolescent↗

PubMed2004

Effects of customized bicarbonate buffered solutions for continuous renal replacement therapies on polymorphonuclear leukocytes function and viability.

It has previously been shown that the mixture of bicarbonate and calcium in the solutions used for continuous renal replacement therapy led to crystallization and significant changes in calcium concentration and pH. The aim of this study was to investigate the impact of bicarbonate/calcium and lactate/calcium solutions for Continuous Renal Replacement Therapies (CRRT) on the viability and function of polymorphonuclear cells (PMN). We tested four customized bicarbonate buffered solutions: single bag (bicarbonate and calcium mixed 24 h before testing), double bag (mixed immediately before testing), filtered single bag and double bag solutions, and a commercial lactate buffered solution. Blood from 6 volunteers was incubated with the solutions for 30 min followed by PMN isolation. After overnight incubation, viability, phagocytosis, and peroxide production by PMN were determined by flow cytometry. There was no difference between the test solutions with respect to PMN viability and function. Therefore, the presence of microcrystals and the consequent changes in electrolyte concentrations do not seem to impair PMN function.

Analysis of Variance↗

PubMed2003

Is serum albumin a marker of nutritional status in hemodialysis patients without evidence of inflammation?

Hypoalbuminemia, a strong predictor of morbidity and mortality in hemodialysis patients, can be a consequence of a combination of malnutrition and inflammatory reactions. The purpose of this study was to analyze serum albumin as a marker of nutritional status in maintenance hemodialysis patients with no signs of inflammation. In a cross-sectional study, we selected 40 stable hemodialysis patients with normal levels of C-reactive protein (<0.8 mg/dL). The patients were classified as well nourished (65%) or malnourished (35%) according to the subjective global assessment. No significant differences were observed in serum albumin concentrations (immunoturbidimetric method) between well-nourished (4.3 +/- 0.3 g/dL) and malnourished (4.0 +/- 0.5 g/dL) patients, and the mean values were within the normal range in both groups. Albumin was inversely correlated with age (n=40; r=-0.32; P=0.02) and directly with energy intake (n=28; r=0.43; P=0.04). In this study, serum albumin did not discriminate well-nourished and malnourished hemodialysis patients without evidence of inflammation.

Adult↗

PubMed2003

Soluble Fas: a novel marker of inflammation in uremia.

BACKGROUND: Inflammation has been associated with atherosclerotic cardiovascular disease (CVD) and anemia in patients with end-stage renal disease (ESRD). Recent studies have shown that serum levels of soluble Fas (sFas), an antiapoptotic and proinflammatory molecule, are elevated in patients with cardiac disease and patients with ESRD. We therefore sought to investigate serum levels of sFas in uremic patients and its correlation with known markers of inflammation, anemia and CVD. METHODS: The study included 25 ESRD patients (14 on hemodialysis, 11 on CAPD), 27 patients with chronic kidney disease (CKD; creatinine clearance <50 ml/min/1.73 m2), and 14 normal control subjects. We measured serum levels of sFas, C-reactive protein (CRP), and albumin. We also investigated the association of serum sFas levels with the presence of CVD and with erythropoietin (EPO) dosage. RESULTS: Levels of sFas were elevated in CKD and ESRD patients compared to controls. sFas levels correlated negatively with creatinine clearance. In the dialysis patients, we observed that sFas levels were higher among those with CVD. Serum levels of sFas correlated with serum levels of CRP (r=0.31; P=0.03), serum levels of albumin (r=-0.35, P=0.02), and EPO dosage (r=0.51; P=0.009). CONCLUSION: These results suggest that sFas may be a marker of inflammation in CKD and ESRD patients.

Adult↗

PubMed2003

Comparison of skinfold thicknesses and bioelectrical impedance analysis with dual-energy X-ray absorptiometry for the assessment of body fat in patients on long-term haemodialysis therapy.

BACKGROUND: Body composition assessment in patients with chronic renal failure is of paramount importance since studies have demonstrated the association of protein-energy malnutrition with an increased morbidity and mortality in this population. However, practical and sensible indicators of body compartments are still needed for clinical purposes. Thus, we aimed to evaluate the simple methods of skinfold thicknesses (SKF) and bioelectrical impedance analysis (BIA), using dual-energy X-ray absorptiometry (DEXA) as a reference method, for the assessment of body fat in patients on long-term haemodialysis therapy. METHODS: We studied 30 clinically stable patients (15 men/15 women) undergoing haemodialysis at the Dialysis Unit of the Federal University of São Paulo. Body fat assessment was performed by the SKF, BIA and DEXA methods after a haemodialysis session. Analysis of variance, intra-class correlation coefficient and Bland and Altman plot analysis were used for comparative analysis among the methods. RESULTS: Body fat estimates by SKF (17.7 +/- 7.8 kg) and BIA (18.6 +/- 9.2 kg) were not significantly different from those obtained by DEXA (18.2 +/- 7.9 kg) considering the whole population. However, the BIA technique worked differently from DEXA when analysed by gender, measuring less fat content in men and higher fat content in women (P < 0.01). No differences were observed for SKF. Strong intra-class correlation coefficients (r) were found between DEXA with SKF (r = 0.94) and BIA (r = 0.91). DEXA showed a relatively good agreement with both SKF [0.47 +/- 2.8 (-5.0 to 6.0) kg] and BIA [-0.39 +/- 3.3 (-6.9 to 6.1) kg] in all patients according to the Bland and Altman plot analysis. However, considering gender, BIA showed greater mean prediction error of 1.93 +/- 2.5 (-3.0 to 6.8) kg for men and -2.71 +/- 2.3 (-7.2 to 1.8) kg for women. CONCLUSIONS: The simple and long established method of SKF was preferable over BIA, which showed gender-specific variability in the assessment of body fat in patients undergoing haemodialysis. However, more comparative and longitudinal studies are needed to evaluate the applicability of these practical methods for monitoring body composition in the routine care of patients with chronic renal failure.

Absorptiometry, Photon↗

PubMed2003

A model for improving quality in nephrology settings.

Continuous quality improvement (CQI) programs have been instituted in many health care organizations over the last decade. PDCA, a tool composed of planning (P), doing (D), checking (C), and acting (A), has proved to be very useful in the CQI problem-solving process. The use of the PDCA tool described in this article resulted in the successful resolution of a hepatitis B outbreak in a Brazilian hemodialysis population and can serve as a model methodology for improving care in nephrology settings.

Brazil↗

PubMed2002

Correlates of urea kinetic modeling during hemodialysis in patients with acute renal failure.

The current guidelines on dialysis adequacy in acute renal failure (ARF) are loosely defined and have been extrapolated from patients with end-stage renal disease. The objectives of this study were (1) to compare three methods of urea kinetic modeling measurement in patients with ARF receiving intermittent hemodialysis, (2) to compare prescribed to delivered dose of dialysis, and (3) to explore the factors that are associated with dialysis delivery. 'Single-pool' urea kinetic modeling was assessed by the Ureakin) software and the second-generation equation which uses a logarithmic estimate of spKt/V. 'Equilibrated' Kt/V (eKt/V) was calculated using the rate adjustment equation. The prescribed dose was derived using the manufacturer's specifications of the dialyzer clearance, prescribed time, actual delivered blood and dialysate flow, and estimates of volume of urea distribution. A total of 78 consecutive spKt/V measurements were obtained in 24 patients. The mean urea reduction ratio was 51 +/- 1%. The delivered spKt/V was significantly lower than that prescribed (0.87 +/- 0.03 or 0.83 +/- 0.03 vs. 1.28 +/- 0.05; p = 0.0001). The equilibrated Kt/V was markedly lower than the delivered spKt/V (0.73 +/- 0.03 vs. 0.83 +/- 0.03; p = 0.0001). Univariate analyses demonstrated that female gender, low body mass index, low predialysis weight, use of cellulose acetate dialyzers, and increased prescribed time were associated with increased odds of prescribed spKt/V > or =1.2. Similarly, old age, increased delivered time, and high cytokine production were associated with increased odds of delivered spKt/V > or =1.2. In summary, while the impact of delivered intermittent hemodialysis on the survival of patients with ARF remains to be determined, these results indicate that dialysis delivery is suboptimal in ARF, and empiric dosing should strongly consider factors related to lean body mass, including age and gender.

Acute Kidney Injury↗