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Biomedical subjects

U Donini

Publications and source records attributed to U Donini.

At least 19 recordsLinked to original sources
PubMed1992

Immunohistochemical distinction between amyloidosis and fibrillar glomerulopathy.

Six patients with glomerulonephritis and glomerular proteinaceous deposits constituted by fibrillar ultrastructures similar to those of amyloid but lacking the Congo red tinctorial affinity characterizing amyloid were studied. Clinically, these patients had proteinuria and hematuria; in addition, three patients had hypertension and one renal failure. Protein deposits in their kidney biopsy sections were evaluated by immunofluorescence, immunoperoxidase, and immunoelectron microscopic (protein A-gold) techniques, using antibodies against IgG, IgA, IgM, C3, C1q, fibrinogen, immunoglobulin kappa and lambda light chains, and against amyloid fibril proteins of different types, including AA, A lambda, A kappa, and AF. By immunofluorescence and immunoperoxidase, in all cases the deposits stained intensely with antibodies against IgG, C3, and kappa and lambda light chains; one case also showed C1q immunoreactivity. By contrast, none stained with antibodies against various amyloid fibril proteins. Immunoelectron microscopic findings corroborated this data, indicating that the nonamyloid fibrillar deposits studied are antigenically distinct from known amyloid deposits and that they contain IgG-derived material.

Amyloid↗
PubMed1990

Glomerulonephritis with organized deposits: a new clinicopathological entity? Light-, electron-microscopic and immunofluorescence study of 12 cases.

Twelve cases of glomerulonephritis in patients without systemic diseases, displaying organized glomerular deposits, were reported. Microfibrils (11-30 nm diameter) were found in 9 patients and microtubules (20-35 nm diameter) in the other 3. Histochemical stainings for amyloid were always negative. By light microscopy, mesangial proliferative, membranous and membranoproliferative patterns were seen in 5, 3 and 4 patients, respectively. By immunofluorescence, granular deposits, mainly of IgG and C3, were found in all cases, either in the mesangium or in the mesangium and in the capillary walls. A second biopsy was performed in 2 patients. The number of hyaline glomeruli was increased, but the general pattern of glomerular changes remained unchanged. The commonest clinical findings were hypertension, microhematuria and proteinuria, often of nephrotic range. At variance to what is reported in the literature, 2 pediatric cases were found as well, and the overall prognosis (mean follow-up 54.3 months) was mostly favorable. The diagnostic relevance of these findings is pointed out, but further investigations are needed, before suggesting a new clinicopathological entity.

Actin Cytoskeleton↗
PubMed1989

Immunoelectron microscopic classification of amyloid in renal biopsies.

Recent classification of amyloidosis is based on the chemical type of amyloid protein involved. In this study, routinely embedded kidney biopsies from nine patients with generalized amyloidosis and renal involvement were tested by immunoelectron microscopy, using the protein A-gold technique, with a panel of antibodies against the following amyloid proteins: AA, A lambda, A kappa and AF. Among the antibodies, the anti-AA was monoclonal (mc1) and the others polyclonal. In all nine cases, only one type of antibody reacted with each amyloid type. Six cases were classified as AA and three cases as A lambda type. These classifications were in agreement with the clinical data and the results of serum and urine immunoelectrophoresis. The gold particles were always associated with amyloid fibrils. No reaction was evident when an amyloid type was stained by a non-corresponding antibody, or in the four control cases without amyloid. The results show that antigenic classification of amyloid is feasible on routinely processed ultra-thin epoxy sections by immunoelectron microscopy, and thus affords the possibility of retrospective studies.

Adolescent↗
PubMed1989

Immunoelectron microscopic identification of human AA-type amyloid: exploration of various monoclonal AA-antibodies, methods of fixation, embedding and of other parameters for the protein-A gold method.

Using the postembedding protein-A gold technique ten monoclonal antibodies directed against amyloid-A protein (AA) were examined by immunoelectron microscopy to identify amyloid-A (AA) amyloid fibrils in plastic-embedded renal tissue of five patients and two controls. Two monoclonal antibodies (mc1, mc20) specifically labeled these amyloid deposits; two additional ones (mc4, mc13) bound with an intermediate rabbit anti-mouse IgG antiserum. These monoclonal anti-AA antibodies clearly separate amyloid fibrils from morphologically similar fibrils in the vicinity. Employing varying embedding media, fixation techniques, as well as etching and staining protocols, we adapted this method for the immunoelectron microscopic identification of AA-type amyloid fibrils and for the antigenic diagnosis of AA-type amyloid on routinely processed ultrathin sections.

Amyloidosis↗
PubMed1987

Identification of a 400-kd protein in the brush borders of human kidney tubules that is similar to gp330, the nephritogenic antigen of rat Heymann nephritis.

The nephritogenic antigen of Heymann nephritis (HN)--a well-studied experimental rat model disease of human membranous glomerulonephritis (MGN)--was recently shown to be a 330-kd glycoprotein (gp330) which is present in the membranes of both the rat tubular brush borders and of podocytes. Because the pathogenic antigen(s) of MGN are unknown, the authors have searched for a gp330-like molecule in human kidney and for its role in MGN. The authors here report that a membrane protein (apparent molecular weight 400 kd) is present in human kidney which is immunologically cross-reactive with rat gp330. By immunoelectron microscopy (using rabbit anti-rat gp330 IgG or a monoclonal anti-400-kd IgG) this molecule is similarly localized in human proximal tubules, but it is absent from the podocytes of human glomeruli. The 400-kd molecule is not detected in the glomerular immune deposits of 30 biopsies of MGN. It is proposed that this is due to the lack of the 400-kd protein in human glomeruli which prevents the formation of initial 400-kd anti-400-kd IgG immune complexes in situ.

Animals↗
PubMed1987

Prognostic factors and effectiveness of treatment in acute renal failure due to multiple myeloma: a review of 50 cases. Report of the Italien Renal Immunopathology Group.

We studied 50 patients with myeloma acute renal failure to investigate possible prognostic factors and to evaluate the effectiveness of the various treatment schedules used. Renal failure was reversible 1 month after the onset in 50% of the patients considered. The patients treated with chemotherapy and plasma exchange recovered renal function more frequently (61% of the cases) than those treated only with chemotherapy (27%). The most important clinical prognostic factors were total proteins, serum creatinine values and myeloma type. Considering the histological findings, the prognosis correlated with the severity of the lesions and number of tubular casts. Survival at 1 year was higher in the patients who regained renal function than in those in whom renal function did not improve.

Acute Kidney Injury↗
PubMed1986

Clinical and morphologic evolution of idiopathic membranous nephropathy.

Twenty-five adult patients with idiopathic membranous nephropathy (IMN) and nephrotic syndrome (NS) who had participated at a long-term randomized trial with steroid and chlorambucil for six months, underwent repeated renal biopsies. The mean interval between pretreatment and the second biopsy was 41 months. Five evolutionary morphologic changes were adopted. Extensive normalization of the basement membrane (stage V) was observed in 6 of the 9 patients with complete and sustained remission. Only patients in stages I or II at admission seemed to get to reparation stage V. Persistence of NS or a partial remission was usually associated to the progression of the capillary wall lesion to stage III or IV. Our treatment schedule significantly increased the likelihood of getting to the reparation stage V.

Adolescent↗
PubMed1984

Immunohistochemical typing of amyloid on hydroxyethyl-methacrylate-embedded renal biopsies.

Hydroxyethyl-methacrylate (GMA)-embedded renal biopsies containing amyloid were tested by the indirect immunoperoxidase method with antibodies against the following purified amyloid fibril proteins: AA, three different A lambda preparations, Ak and AF. The anti-AA reagent was monoclonal (mc13), all the others were polyclonal. In four biopsies from cases with generalized amyloidosis, two were found to be of the AA and two of the A lambda type. Two control cases of membranous glomerulonephritis showed only a marginal reaction with anti-A lambda. These results demonstrate that GMA-embedded tissue sections are suitable for immunohistochemical classification of amyloid diseases, because proteinaceous antigenic determinants of amyloid fibril are preserved.

Aged↗
PubMed1983

Focal glomerulosclerosis in patients with unilateral nephrectomy.

To investigate whether proteinuria and focal glomerulosclerosis (FSG) might develop in humans as well as in experimental models following a reduction in renal mass, we performed a retrospective study of 24 patients previously nephrectomized for unilateral renal disease. None of the patients presented signs of systemic diseases. Alport syndrome, essential hypertension, reflux nephropathy, and other abnormalities on intravenous pyelography. At the time of the first observation seven patients had pathological proteinuria (group 1) while 17 presented a normal protein excretion (group 2). All patients in group 1 and only 4 of 17 in group 2 were male. No other significant differences were found between the two groups. The median age at nephrectomy of the proteinuric patients was 22.3 years, and proteinuria developed after a mean period of 12.2 years. A renal biopsy was performed in four patients and showed a constant pattern of FSG. After a mean follow-up period of 7.3 years from the onset, proteinuria remains unchanged and renal function is well preserved in all the patients. In conclusion our series suggests that also in humans proteinuria and FSG might appear in solitary kidneys due to nephrectomy. This glomerular damage may result from the association of glomerular overload with other unidentified factors.

Adult↗
PubMed1983

Immunohistochemical staining on hydroxyethyl-methacrylate-embedded tissues.

Hydroxyethyl-methacrylate (GMA) embedding has recently been proposed for light microscopy studies. In the present investigation extracellular protein antigens were localized on GMA-embedded renal biopsy tissue. Conventionally frozen sections were compared with GMA sections from 55 renal specimens for the detection of extracellular protein antigens. Sections were directly stained with fluorescein- or peroxidase-conjugated antisera against immunoglobulin (Ig) G, IgA, IgM, C3, C1q, and fibrinogen. Results obtained using these two methods showed a 74-89% agreement, depending on the antigen under study. Some discrepancy between GMA and frozen sections was observed in three cases of renal amyloidosis and those cases presenting focal or trace reactions; the differences did not, however, influence the diagnosis. Prerequisites for antigen recovery on GMA sections were a) choice of fixative; b) abrupt dehydration of specimens; and c) treatment of sections with nonspecific protease. The improved localization and the lower background staining obtained led to easy and immediate detection of antigens on GMA sections despite the reduced antigenicity due to the embedding process.

Acrylates↗
PubMed1983

Berger's nephropathy: relationship between histological pattern, blood pressure and renin.

Vascular damage (VD), glomerular sclerosis (GS), renin (PRA) and blood pressure were assessed in 50 patients with Berger's nephropathy. GS was present in 5/15 patients without VD and affected more than 15 per cent of glomeruli in seven patients with minimal VD. Nine out of 19 patients with GS were normotensive. VD was present in 35 patients: 16 were hypertensive and 19 normotensive. Therefore hypertension is not the only mechanism responsible for VD. In the seven normotensive patients with high PRA, GS was not present while VD was absent or minimal.

Adolescent↗
PubMed1983

The presence of J chain in mesangial immune deposits of IgA nephropathy.

In order to identify polymeric IgA in the mesangial IgA deposits of 33 patients, the presence of J chains by a PAP method was investigated. In 9/27 cases of primary IgA nephropathy (PIgANP) and in 4/4 cases of Henoch-Schönlein glomerulonephritis (HSGN) J chains were absent. The remaining cases, two of them with IgA glomerulonephritis associated with alcoholic cirrhosis (ACIgAGN), were J-positive. The two groups, PIgANP J-positive and PIgANP J-negative, were compared according to clinical features. The only difference detected was the time length between the disease onset and the renal biopsy, being shorter in the negative group.

Adult↗
PubMed1980

BK papovavirus immune complexes in glomerulonephritis.

Kidney biopsies from 98 patients were studied for BK virus (BKV) antigens by indirect immunofluorescence. Intense fluorescent staining was observed in 11/12 cases of lupus nephritis, 11/12 cases of membranous nephropathy, 21/23 cases of IgA mesangial glomerulonephritis, 3/4 cases of membrano-proliferative Glomerulonephritis and 5/12 cases of exudative glomerulonephritis. Antisera of different viruses did not react with any kidney sample. Deposition of BKV was strictly related to the presence of immunoglobulins in renal glomeruli. The specificity of reaction for antigens related to BKV was demonstrated by absorption of sera with different substances and BKV. Absorption of rabbit anti-BKV serum with human immunoglobulins completely abolished glomerular fluorescence. We conclude that the fluorescence obtained in kidney biopsies by staining with anti-BKV serum was a false positive reaction dependent on common antigenic determinants present in BKV capsid proteins and human immunoglobulins.

Antigen-Antibody Complex↗