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L Allegri

Publications and source records attributed to L Allegri.

At least 55 records · Page 3Linked to original sources
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[Etiopathogenesis of membranous nephropathy: is there a correlation between experimental and human pathology?].

The Authors discuss the etiologic, pathogenetic and immunopathologic aspects of Heymann nephritis, in order to compare the numerous acquisitions concerning this nephropathy with the scanty knowledge of human membranous nephropathy, of which it represents the experimental counterpart. This rat disease can be obtained by inoculation of tubular brush border preparations (active form) or of the relevant antibodies (passive form); after an initial hypothesis of glomerular deposition of circulating immune complexes, studies on its pathogenetic mechanisms, instead demonstrated that in situ immunoaggregates, caused by an interaction between circulating antibodies and fixed glomerular antigens, are formed. Recent investigations have led to the identification of a major nephritogenic antigen (gp330), which is a tubular brush border glycoprotein expressed by coated pits located at the glomerular epithelial cell surface. Studies on antigen-antibody interactions at this level have demonstrated that there is a quick redistribution and accumulation of the so-formed immune complexes, and when polyclonal antibodies were utilized, growth of subepithelial electron dense deposits was observed. Although other tubulo-glomerular antigens, which can also be expressed by endothelial cells, play an uncertain role, they seem to favour transmembrane passing of anti-gp330 antibodies. Immune complex formation gives rise to the onset of proteinuria through complement system activation, without leukocyte involvement: in particular a MAC and C9 fraction lytic effect was demonstrated on cultured epithelial cells. In conclusion, studies on Heymann nephritis contribute to our understanding of the etiopathogenetic mechanisms regarding human membranous nephropathy, and emphasize a possible role played by tubular antigens and in situ formed immune complexes.

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[Mechanisms of progression of glomerular sclerosis in chronic renal diseases in man].

The available data indicate that in chronic renal failure (CRF) loss of renal function usually progresses at a constant rate toward end-stage renal disease. Although immunological events might be responsible for initiating most glomerular diseases, certain clinical and experimental observations suggest that the rate of progression of these diseases is influenced by several non immunological factors. These factors include systemic hypertension, proteinuria, hyperlipidemia, high protein intake, and probably conditions leading to glomerular hypertrophy. Interventions designed to minimize the potential contribution of these factors to the progression of renal insufficiency may halt or slow the loss of function at early and late stages of CRF.

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A diffusion immunogold procedure for accurate ultrastructural investigation of renal cell membrane epitopes.

A role for renal antigenic targets has been supposed and sometimes convincingly demonstrated in the development of various types of experimental glomerulonephritides. In this report we describe a reliable protocol for accurate ultrastructural investigation of antigens on the renal cell surface by means of a pre-embedding technique associated with colloidal gold staining. Sprague-Dawley rats were injected with a monoclonal antibody specific for a 90-kD cell membrane glycoprotein and killed 12 or 48 h later; after prefixation, renal fragments were cryoprotected and snap-frozen. Cryostat sections were incubated with a 5-nm colloidal gold-goat antimouse antibody, postfixed in osmium tetroxide reduced with potassium ferrocyanide and embedded in Durcupan ACM. At the glomerular level, gold granules were localized on the endothelial cell surface. In the proximal tubules uniform labelling was noticed on the brush border microvilli, followed by later marking of the basolateral membranes. By this pre-embedding immunogold method we obtained suitable histological preservation and fine resolution of the cell membrane immunoreactive sites. This procedure represents a useful tool for ultrastructural studies on the interaction of circulating antibodies with renal cell surface antigens.

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