Validation of QB stress test as a useful tool in the detection of native arteriovenous fistula stenosis: results after 22 months of follow-up.

Background: Access flow (QA) surveillance is the best method recommended for early stenosis detection, but in native arteriovenous fistula (AVF), the literature is conflicting about the real need for monthly monitoring of QA, as suggested by the K-DOQI Guidelines.

Methods: From 1 January 2006 to 31 October 2007 (mean 18.0 +/- 4.

Epithelial-mesenchymal transition of tubular epithelial cells in human renal biopsies.

Background: In recent studies performed on cultured cells and experimental nephropathies, it has been hypothesized that tubular epithelial cells (TEC), via epithelial-mesenchymal transformation (EMT), can become collagen-producing cells. According to this theory, they should proceed through several activating steps, such as proliferation and phenotype changes, to eventually synthesize extracellular matrix (ECM).

Methods: To evaluate whether EMT operates in human TECs, 133 renal biopsies of different renal diseases were studied, analyzing by immunohistochemistry and in situ hybridization the possible expression of markers of proliferation (PCNA, Mib-1), cellular phenotype (vimentin, alpha-SMA, cytokeratin, ZO-1) and ECM production (prolyl 4-hydroxylase, HSP47, interstitial collagens).

Glomerular monocyte-macrophage features in ANCA-positive renal vasculitis and cryoglobulinemic nephritis.

Although it is widely known that many macrophages are present in glomeruli of antineutrophil cytoplasmic antibody (ANCA)-positive renal vasculitis (ANCA + RV) and are believed to contribute to necrotizing extracapillary damage, their precise role is not yet completely understood, especially in humans. The goal of this study was to provide evidence of glomerular macrophage properties in human vasculitis. Twenty-five renal biopsies of ANCA + RV and 18 cases of cryoglobulinemic glomerulonephritis (cryoGN), a disease characterized by massive glomerular macrophage infiltration but absence of necrotizing extracapillary lesions, were selected, and macrophage number, adhesion, acute activation, proliferation, and apoptosis were analyzed by immunohistochemistry and in situ hybridization.