The pathogenesis of dialysis related amyloidosis, which occurs preferentially in osteo articular tissues, is still incom pletely understood. Although recent histological studies have shown the accumulation of monocytes/macrophages around amyloid deposits, the factor(s) causing their infiltration and pathological involvement have yet to be fully elucidated. The present studies demonstrate that ? 2 microglobulin (? 2 m), the major constituent protein in amyloid fibrils, can be modified in situ by advanced glycation end products (AGE) through binding to AGE modified collagen. AGE ? 2 m attracts monocytes via direct chemotaxis and through regulation of synoviocyte derived chemokine. AGE modified ? 2 m significantly delays spontaneous apoptosis of human monocytes via a pathway mediated by the receptor for AGE (RAGE), processes which may increase the accumulation of inflammatory monocytes. In addition to recruit monocytes, AGE ? 2 m stimulates macrophages to release IL 1?, TNF ? and IL 6.These proinflammatory cytokines upregulate the expression of adhesion molecules such as ICAM 1 and VCAM 1 by synovial cells and induce the release of synoviocyte derived collagenase which may contribute to the degradation of matrix. These AGE ? 2 m induced perturbation of monocytes and cellular inflammatory reactions eventually result in osteo articular tissue damage and destruction seen in DRA.

Infection is a common, serious and costly complication in patients with chronic renal failure (CRF) and has been the major cause of high mortality in these patients. Increased evidences suggest that prophylaxis can significantly decrease the prevalence of infections in CRF patients, such as tuberculosis, S. aureus infection and hepatitis virus induced liver diseases. It remains an important issue for clinical nephrologists to investigate and to provide strategies for prevention and treatment of various infections in CRF patients.

Enhanced expression of adhesion molecules on human endothelial cells of synovial tissue has been demonstrated in patients with dialysis related amyloidosis(DRA).The study was conducted to elucidate the mechanism by which the expression of adhesion molecules on human endothelial cells was up regulated. Human endothelial cells derived from umbilical veins(HUVEC) were coincubated in vitro with native human serum albumin(HSA) or HSA modified with advanced glycation end products(AGE HSA).The expression of adhesion molecule intercellular adhesion molecule 1(ICAM 1),vascular cell adhesion molecule 1(VCAM 1) and E selectin was determined respectively by immunofluorescence staining and flow cytometer analysis.The results showed that ICAM 1 and VCAM 1, but not E selectin,were constitutively expressed on HUVEC. AGE HSA enhanced the expression of ICAM 1, VCAM 1 and E selectin on HUVEC in a time and dose dependent manner. HSA had no effect on the expression of adhesion molecules. The results led to the conclusion that AGE HSA up regulated the expression of adhesion molecules on human endothelial cells and therefore promoted the infiltration of monocytes/macrophages around ? 2 microglobulin amyloid.

Radioactive ligand receptor binding assay was used to study the binding effect of heparin and low molecular weight heparin (LMWH) on the receptor of advanced glycation end products (AGE) on monocyte surface in normal individual and chronic renal failure (CRF) patients undergoing hemodialysis. The results showed that heparin caused a dose dependent inhibition of receptor binding to AGE, however LMWH did not have such inhibitory effects. The results suggest that heparin could interrupt AGE clearance and degradation, and LMWH had not these effects.

The study was performed to detect the binding proteins for advanced glycation end products (AGEs) on human joint synovial cells (HSCs). Normal human synovial cells (type A and type B cells) were isolated and cultured in vitro. Binding assay was performed with radiolabeled human serum albumin modified by AGE (AGE HSA). Specific binding was defined as total binding minus binding in the presence of excess unlabeled AGE HSA. The result showed that: specific dose dependent binding of 125 I AGE HSA to immobilized HSCs was observed with R=4.90 0.75 10 4 /cell , Kd = 1.27 0.19 10 -6 M in type A HSCs , and R= 3.48 0.32 10 5 /cell, Kd= 1.38?0.16 10 -7 M in type B HSCs. TNF ?,IL 1? and AGE HSA upregulated the expression of AGE binding proteins on HSCs. Normal HSCs express specific AGE binding proteins. TNF ?, IL 1? and AGE HSA upregulate the expression of these proteins, suggesting that joint resident cells may be involved in the pathogenesis of dialysis related amyloidosis.

Objective To investigate hyperhomocysteinemia in chronic renal failure (CRF), its prevalence, etiology and potential relationship to arteriosclerotic events. Methods Plasma total homocysteine (tHcy) was measured in 160 patients with CRF, 31 patients with coronary artery disease and 45 healthy controls by using fluorescence polarization immunoassay. Results Eighty-two percent of CRF patients had hyperhomocysteinemia compared to 22% in patients with coronary artery disease. Mean plasma tHcy level in heomodialysis (HD) patients [(24. 13 ?12. 68) ?mol/L] was significantly higher than that in continuous ambulatory peritoneal dialysis (CAPD) patients [(16. 43?5. 58) ?mol/L] and that in normal controls [(7. 97 ?2. 65)?mol/L] . Plasma tHcy level in dialysis patients with cardiovascular diseases [(27. 12 ?15. 94)?mol/L, n=30] was higher than that in those without clinical manifestation of these complications [(20. 17?8. 71) ?mol/L, n = 62] . The levels of tHcy correlated inversely with Ccr (r = -0. 374, P

To elucidate the effects of pro inflammatory mediators on mRNA expression of AGE receptors in type B synovial cells, type B synovial cells from normal subjects were isolated and cultured in vitro with human serum albumin modified with advanced glycation end products (AGE HSA), tumor necrosis factor ?(TNF ?)and interleukin 1?(IL 1?). The expression of RAGE mRNA and AGE R3 mRNA was examined by RT PCR techniques. TNF ?, AGE HSA and IL 1? up regulated the expression of AGE R3 mRNA in type B synovial cells in a dose and time dependent manner. In contrast, TNF ? and AGE HSA down regulated the expression of RAGE mRNA in a dose and time dependent manner. IL 1? had no effect on RAGE mRNA expression. The regulatory responses induced by AGE HSA were blocked by a neutralizing polyclonal anti human TNF ? antibody, suggesting that the effects of AGE HSA were mediated by TNF ?. The proinflammatory mediators may regulate the gene expression of AGE receptors in type B synovial cells, and the regulatory role of these receptors is different in response to the proinflammatory mediators.

Objective To evaluate the clinical characteristics and prognostic factors in patients with acute renal failure (ARF) due to sepsis. Methods A case-control retrospective study was carried out in patients with acute renal failure due to sepsis and non-sepsis. Univariate and multivariate logistic regression analysis was performed to find the correlation among prognosis, clinico-biochemical parameters and scoring indexes of APACHE II and ATN-ISI. Results The incidence of septic ARF was 15. 6% in all ARF patients. Multiple organ failure was most common (87.9% ) in these patients with a high mortality (69. 7% ). Single-variable analysis showed that surgery, respiratory failure, hepatic failure, mechanical ventilation, oliguria, coma, multiple organ failure, ARF occurred during ICU stay and chronic health points were factors influencing prognosis. Multivariate logistic regression analysis showed that oliguria, ARF occurred during ICU stay, chronic health points, and multiple organ failure were the independent predictors of hospital mortality. Conclusion Outcome of septic ARF is correlated with factors including oliguria, ARF occurred during ICU stay, chronic health points and multiple organ failure.

The aim of this study was to investigate the effect of patients isolation,paying careful attention to hygienic measure and strict sterilization on prevention of hepatitis C infection in hemodialysis(HD) unit. Patients in our HD unit from May 1994 to May 1998 were isolated and strict sterilization of dialysis apparatuses were performed, while patients from April 1990 to April 1994 were not isolated. The rate of HCV infection in these two groups of patients were 18 20% and 26 72%, respectively ( P

The study was performed to investigate the prevalence of nasal carriage of Staphylococcus aureus (NCSA) in patients with chronic renal failure(CRF) and its relationship with incidence of bacteremia in patients on hemodialysis(HD). The preventive effect of external application of mupirocin ointment on HD patients with venous catheters was also observed. Nasal swabs were taken from 114 CRF patients hospitalized from Nov. 2000 to April 2002. Samples from 42 patients in CCU with normal renal function and 48 staffs working in HD centre were also analyzed. External application of mupirocin ointment near the exit sites of catheters was performed as prophylaxis in HD patients with venous catheters. The prevalence of SA bacteremia was compared with that of the historical control group from Jan.1999 to Oct.2000. The results showed that the prevalence of NCSA in CRF patients was 14% (16/114). Nasal swab cultures were all negative in CCU patients, as well as staffs working in the HD centre. The mean frequency of SA bacteremia in HD patients with NCSA was 0 12/catheter month, compared to 0 in HD patients with no NCSA( P