Biomedical subjects

Renato Watanabe

Publications and source records attributed to Renato Watanabe.

5 recordsLinked to original sources

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↗

PubMed2004

Balance between cytokine production by peripheral blood mononuclear cells and reactive oxygen species production by monocytes in patients with chronic kidney disease.

Hemodialysis (HD) and peritoneal dialysis are associated with inflammatory events and immunological incompetence. The purpose of this study was to evaluate the effect of both uremia and dialysis modality on the production of cytokines and reactive oxygen species (ROS) by monocytes. four groups of subjects were studied: 28 chronic kidney disease (CKD) patients, 14 chronic HD patients, 14 patients on continuous ambulatory peritoneal dialysis (CAPD) patients, and 14 healthy volunteers, peripheral blood mononuclear cells (PBMC) were isolated from blood samples and incubated for 24 hr with or without lipopolysaccharide (LPS). TNF-alpha and IL-10 production by PBMC and serum levels of these cytokines were quantified by ELISA. Aliquots of whole blood were incubated in vitro and ROS production and phagocytosis were quantified by flow cytometry. Compared to the control group, Staphylococcus aureus-stimulated ROS production by monocytes was significantly lower in the HD group. The highest levels of unstimulated TNF-alpha production in vitro were observed in the HD group. In the CKD group, as well as in the whole population, there were a negative correlation between TNF-alpha production by unstimulated PBMC and ROS production by S. aureus-stimulated monocytes and a positive correlation between PMA-stimulated ROS production by monocytes and unstimulated and LPS-stimulated IL-10 production by PBMC suggesting that the pro-inflammatory state in CKD patients is associated with decreased response to infectious challenges.

Adult↗

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↗

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

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↗