Biomedical subjects

S Colon

Publications and source records attributed to S Colon.

At least 37 records · Page 2Linked to original sources

PubMed1991

[Diseases associated with renal amyloidosis. Apropos of 216 cases].

Diseases associated with renal amyloidosis were evaluated in 216 patients observed between 1956 and 1989. The percentage of secondary amyloidosis decreased from 72 to 47%, where it has remained for the past 20 years, despite the clear diminution in the tuberculosis rate; this is due to its increased incidence of association with rheumatoid diseases. Dysglobulinemia was found in more than 75% of the patients with AL amyloidosis. Amyloidosis associated with this dysglobulinemia, of which 30% were myelomatous, represented more than 25% of the cases observed during the past decade and constituted, with rheumatoid arthritis, the two most common etiologies.

Adolescent↗

PubMed1991

[Significance of cytolipiduria during a nephrotic syndrome].

Phase contrast examination of urine sediment of patients with the nephrotic syndrome shows cytolipiduria in 62.8% of cases. Cytolipiduria is mostly observed in patients between 20 and 80, and is, in most cases, associated to cytological features of glomerular and/or tubular injury. In absence of cytolipiduria, renal biopsy most often shows minimal change disease. Membranous glomerulonephritis is observed in most cases with high cytolipiduria. However, urine sediment is not predictive of renal histologic lesions and progressive glomerulonephritis can be observed in absence of cytolipiduria.

Adult↗

PubMed1991

[Renin secreting tumor and severe hypertension. Apropos of a new case].

A renin-secreting tumour has been observed in a 32-year-old female with severe hypertension known for 17 years. The excision of the tumour lead to the complete normalisation of the blood pressure. Histological examination showed that the tumour was benign, contained secretion granules at different stages of maturation, and derived from the juxta-glomerular apparatus. After reviewing the 40 cases previously reported in the literature we discuss the clinical presentation of this type of tumour and the approach to their diagnosis.

Adult↗

PubMed1990

Familial infantile nephrotic syndrome with ocular abnormalities.

Two siblings born from consanguineous parents experienced infantile nephrotic syndrome with ocular and neurological abnormalities; the boy also had a micropenis; both patients died before age 1 year. An initial renal biopsy followed by a two-step binephrectomy allowed good histological assessment of disease progression in one patient. The progression of the lesions was characterized by mesangial involvement, then an extensive extracapillary proliferation and tubular dilatations with a high mitotic activity of the epithelium and nuclei of unequal size. The main features involved major ultrastructural changes of the glomerular basement membrane. These two patients may represent a new disease entity or a severe form of diffuse mesangial sclerosis, with autosomal recessive inheritance.

Cataract↗

PubMed1990

[Nephropathy and Charcot-Marie-Tooth disease. A case report].

A 12 year-old girl with a family of Charcot-Marie-Tooth neuropathy was referred to us with mild proteinuria without hematuria or renal insufficiency; a renal biopsy specimen showed focal glomerulosclerosis. Two years later, proteinuria and renal function were quite stable and there was no arterial hypertension. Of 13 other cases in the literature, the outcome of renal involvement has the same profile:proteinuria at onset with or without microhematuria, sometimes with nephrotic syndrome; the prognosis is often poor, since 9 out of 13 patients have end-stage renal failure after 6 months to 17 years of follow-up. The pathological examination show focal glomerulosclerosis in most cases. Nerve deafness is uncommon in Charcot-Marie-Tooth disease but was present in 7 out of 13 patients with the nephritis. Such an association may be a variant of the dominant autosomal form of the disease, whose gene is located on chromosome 1.

Charcot-Marie-Tooth Disease↗

PubMed1990

[Membranous glomerulonephritis in children: 20 cases].

Twenty cases of membranous glomerulonephritis have been diagnosed between 1978 and 1988 in children (13 girls, 7 boys) aged 4 to 15 years, observed for a 5.1 +/- 2.9 year period. The conditions of the diagnosis were: routine urinalysis in 10 cases, edema in eight, and the surveyance of a D-penicillamine treatment in two. All the patients had proteinuria (0.3 to 15 g/24 h) ranging to nephrotic syndrome in nine children. Microscopic hematuria was found in 16 children (80%). Elevated blood pressure was recorded in two cases at the time of diagnosis, and developed in two other cases during the follow-up. One child experienced renal failure at the onset of the disease. Most histological lesions consisted in stage II membranous glomerulonephritis. Immunofluorescence study (18 biopsies/20) always showed granulosus and intensive IgC deposits, associated with IgM and IgA deposits which were less marked; intensive extra-membranous C3 deposits were noted in 11 cases. As to the etiology, D-penicillamine was responsible for two cases (10%) and HBs antigen in one (5%); the nephropathy was considered as idiopathic in the 17 remaining cases (85%). Regarding the evolution: in eight cases (38%) proteinuria disappeared by 54 +/- 28 months; in 10 cases (55%), proteinuria persisted after 41 +/- 31 months; hematuria, which was present at onset, disappeared in most cases (13/17); in one case (5%), end-stage renal failure occurred within 3 years. The patient with initial renal failure has been last sight off.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1990

Cyclosporin A-sensitive nephrotic syndrome preceding Hodgkin's disease by 32 months.

A 20-year-old man developed a massive nephrotic syndrome, rapidly complicated by pulmonary embolism and septicemia. Two renal biopsies taken 3 months apart showed minimal change glomerulonephritis. Treatment with prednisolone 1.5 mg/kg/day failed to induce a sustained remission, then monotherapy with cyclosporin A (CsA, 5 mg/kg/day) was started. Complete remission was obtained after 15 weeks. CsA was gradually tapered to 3 mg/kg/day. Twenty-two months after starting CsA, a routine examination disclosed a right sub-clavicular lymph node, of which histological examination showed a class 4 large cell Hodgkin's lymphoma. CsA was abruptly withdrawn and a polychemotherapy resulted in lymphoma remission after four courses. Ten months later, Hodgkin's disease is currently in remission and there is no relapse of proteinuria.

Adult↗

PubMed1989

Induction of class I MHC-restricted, peptide-specific cytolytic T lymphocytes by peptide priming in vivo.

The present study investigated the possibility that protein Ag fragments in the form of peptides could serve as the priming Ag in the generation of a MHC class I-restricted immune response. Trypsin-digested chicken ovalbumin (OVA-TD) fragments were used as the model Ag. The results demonstrate the peptides within OVA-TD, when injected into C57BL/6 mice, could prime T cells which lysed H-2b Ia-EL4 target cells in an OVA-TD-specific manner. In contrast to priming with OVA-TD, immunization of mice with intact OVA did not lead to generation of CTL against OVA-TD or OVA. Furthermore, target cells sensitized with intact OVA failed to be recognized by OVA-peptide-specific CTL indicating that the target cells serving as APC were unable to generate the relevant peptide determinants recognized by the T cells. These results support the idea that the processing pathway within APC for class I-restricted T cells may differ from that used for class II-restricted T cells. Using OVA-TD-specific CTL clones (phenotypically Thy 1+, CD8+, CD4-, Pgp-1+) isolated from primed animals to screen OVA-TD fractions separated by HPLC, two T cell peptide determinants were identified corresponding to OVA sequences 111-122 and 370-381. Both determinants were recognized by CTL clones in the context of the H-2Db molecule.

Animals↗

PubMed1989

Structural requirements and biological significance of interactions between peptides and the major histocompatibility complex.

Previous studies indicate that T cells recognize a complex between the major histocompatibility complex (MHC) restriction-element and peptide-antigen fragments. Two aspects of this complex formation are considered in this paper: (1) what is the nature of the specificity of the interactions that allows a few MHC molecules to serve as restriction elements for a large universe of antigens; and (2) what is the relative contribution of determinant selection (i.e. antigen-MHC complex formation) and T-cell repertoire in determining the capacity of an individual to respond to an antigen? By analysing single amino acid substitution analogues of a peptide antigen (Ova 325-335) as well as by analysing the structural similarities between unrelated peptides capable of binding to the same MHC molecule, we have been able to document the very permissive nature of the antigen-MHC interaction. Despite this permissiveness of binding, it is possible to define certain structural features of peptides that are associated with the capacity to bind to a particular MHC specificity. With respect to the question of the relative role of 'determinant selection' and 'holes in the T-cell repertoire' in determining immune responsiveness, we present data that suggest both mechanisms operate in concert with one another. Thus only about 30% of a collection of peptides that in sum represent the sequence of a protein molecule were found to bind to Ia. Although immunogenicity was restricted to those peptides that were capable of binding to Ia (i.e. determinant selection was operative), we found that about 40% of Ia-binding peptides were not immunogenic (i.e. there were also 'holes in the T-cell repertoire').

Amino Acid Sequence↗

PubMed1989

Structural analysis of peptides capable of binding to more than one Ia antigen.

The Ia binding regions were analyzed for three unrelated peptide Ag (sperm whale myoglobin 106-118, influenza hemagglutinin 130-142, and lambda repressor protein 12-26) for which binding to more than one Ia molecule has previously been demonstrated. By determining the binding profile of three separate series of truncated synthetic peptides, it was found that in all three cases the different Ia reactivities mapped to largely overlapping regions of the peptides; although, for two of the peptides, the regions involved in binding the different Ia specificities were distinct. Moreover, subtle differences were found to dramatically influence some, but not other, Ia reactivities. Using a large panel of synthetic peptides it was found that a significant correlation exists between the capacity of peptides to interact with different alleles of the same molecule (i.e., IAd and IAk), but no correlation was found with the capacity of peptides to interact with different isotypes within the same haplotype (i.e., IAd and IEd). These data suggest that different alleles of the same MHC molecule may actually recognize closely related structures, whereas different isotypes may recognize unrelated, albeit non-mutually exclusive, structures on an Ag molecule.

Amino Acid Sequence↗

PubMed1989

[Familial infantile nephrotic syndrome with ocular abnormalities].

Two siblings born from consanguineous parents experienced infantile nephrotic syndrome with ocular and neurological abnormalities and a micropenis in the boy; both patients died before age 1. The opportunity to perform successively a renal biopsy and a two-step binephrectomy permitted a good histological follow-up. The lesions were characterized by mesangial involvement, followed by an extensive extracapillary proliferation and tubular dilatations with a high mitotic activity of the epithelium with anisocaryosis; the main features consisted in major ultrastructural changes of the glomerular basement membrane which were more significant and different from those previously described in the diffuse mesangial sclerosis. These 2 cases may either constitute a new entity or an extreme form of diffuse mesangial sclerosis, supported by recessive autosomal inheritance.

Basement Membrane↗

PubMed1988

I-Ad-binding peptides derived from unrelated protein antigens share a common structural motif.

Purified Ia molecules can specifically bind many unrelated peptide Ag, and such binding appears to be a necessary, albeit not sufficient, prerequisite for the immunogenicity of the proteins from which such peptides are derived. We have recently analyzed the affect of single amino acid substitutions on the I-Ad binding of the immunogenic peptide OVA 323-339. The results obtained demonstrated the very permissive nature of Ag-Ia interaction. We also showed that unrelated peptides that are good I-Ad binders share a common structural motif and speculated that recognition of such motifs could represent a mechanism to achieve a very permissive type of interaction that yet retained some degree of specificity. In the present set of experiments we analyzed the I-Ad binding pattern of a series of overlapping peptides derived from sperm whale myoglobin (residues 102-125) and influenza hemagglutinin (residues 121-146) to determine whether the peptide regions predicted on the basis of structural similarity to be involved in I-Ad binding were in fact involved. In both cases, the I-Ad-interacting determinants were found to contain the sequence motif postulated to be important for I-Ad binding. These data support the hypothesis that I-Ad molecules recognize a large library of Ag by virtue of common structural motifs present in peptides derived from phylogenetically unrelated proteins.

Amino Acid Sequence↗

PubMed1988

[Prognosis of renal vein thrombosis in the adult: influence of treatment].

The medical histories of 27 patients with renal vein thrombosis were evaluated retrospectively. Short and long term evolution as well as prognostic factors were analysed. 24 of the patients were suffering from a nephrotic syndrome, 15 from renal failure. In the 20 biopsies performed we observed: 14 cases of extramembranous glomerulonephritis, 2 cases of minimal glomerular lesions, 3 cases of segmental focal glomerulosclerosis and 1 periarteritis nodosa. The renal vein thrombosis was bilateral (18), left (7) or right (2). In 7 patients this was associated with thrombosis of the inferior vena cava. 9 patients were treated with anticoagulants alone, 9 underwent thrombectomy, 7 were treated by thrombolysis and 2 received no treatment. Within the first six months 11 patients died as a result of complications due to hemorrhaging (5), septic infection (2) or embolism (1) and 3 patients died of undetermined causes. The progression of the remaining patients was followed up over a period of 6 months to 19 years. In 12 patients, the nephrotic syndrome regressed and renal function did not deteriorate in any of the cases. The main causes for poor prognosis are the existence of initial renal failure and glomerulonephritis which is not extramembranous. Since the evolution of the glomerulopathy does not appear to be affected by extramembranous glomerulonephritis, renal vein thrombosis associated with this complication should be treated with anticoagulants alone. The risk-benefit ratio of thrombectomy leads us to conclude that this technique should be abandoned. Thrombolysis could be considered in cases where renal vein thrombosis is associated with acute renal failure.

Acute Kidney Injury↗

PubMed1986

Interaction between a "processed" ovalbumin peptide and Ia molecules.

The binding of 125I-labeled immunogenic peptides to purified Ia molecules in detergent solution was examined by equilibrium dialysis. We used the chicken ovalbumin peptide ovalbumin-(323-339)-Tyr, which is immunogenic in the BALB/c mouse and restricted to I-Ad. 125I-labeled ovalbumin-(323-339)-Tyr was shown to bind to I-Ad but not to I-Ed, I-Ek, or I-Ak. This binding was inhibited by unlabeled ovalbumin-(323-339) but not by ovalbumin-(329-339), which is the longest N-terminally truncated peptide that fails to stimulate any of the I-Ad-restricted hybridomas that have been raised to ovalbumin-(323-339)-Tyr. As a further specificity control, we also used the chicken egg lysozyme peptide Tyr-(46-61), which has recently been studied by similar methods [Babbitt, B. P., Allen, P. M., Matsueda, G., Haber, E. & Unanue, E. R. (1985) Nature (London) 317, 359-361]. We have confirmed that it bound to I-Ak but not to I-Ek, I-Ad, or I-Ed. Thus, a specific interaction between Ia and antigen that correlates with the major histocompatibility complex restriction was demonstrated, strongly arguing in favor of a determinant selection hypothesis for such restriction.

Animals↗

PubMed1986

IgA mesangial deposits in C3H/HeJ mice after oral immunization with ferritin or bovine serum albumin.

In order to study an experimental model of IgA nephropathy, C3H/HeJ mice which are high IgA responders were strongly immunized orally with ferritin and compared to syngeneic C3H/eB. C3H/HeJ exhibited a significant increase of total IgA level in the serum and of IgA deposits in the mesangium. However the low level of IgA antibody to ferritin detected in the serum and the unsuccessful search for ferritin and antibody to ferritin in the glomeruli suggest that strong oral immunization of C3H/HeJ mice leads to high level of non specific IgA in the serum and deposition of IgA in the kidney.

Animals↗

PubMed1986

[Macrophage infiltration in human glomerulonephritis: histochemical study by the non-specific esterase method].

Detection of glomerular macrophages in glomerulonephritis (GN) was attempted in 77 renal biopsies by measuring non-specific esterase (NSE) activity. Macrophage infiltration was at its highest in two cases of cryoglobulinemia (NSE index greater than 10) both associated with a diffuse proliferative GN. In 15 cases of lupus, macrophage infiltration was low or absent (NSE index 0.44). In diffuse proliferative GN (24 cases) only GN with extracapillary proliferation had an NSE index greater than 1. In GN with predominant IgA (23 cases), apart 2 cases of extracapillary forms, there was no notable macrophage infiltration. There is a relation between monocytes and the localization and the quantity of glomerular deposits. The NSE index is higher in the case of large sub-endothelial deposits of immunoglobulins, C3 and/or fibrin.

Biopsy↗

PubMed1985

[Membranoproliferative glomerulonephritis and Mycoplasma pneumoniae infection].

On the occasion of a new case and review of 9 others in the literature, the authors seek to establish the hallmarks of the nephritis occurring after M. pneumoniae infection. It often consists of an acute nephritic syndrome, 10 to 40 days after a respiratory tract infection; hematological abnormalities are not constant. Histological examination of the kidney shows a type I membranoproliferative glomerulonephritis in 2, dense deposit disease in 2 and tubulo-interstitial nephritis in one. Immunofluorescence studies have shown the microbial antigen 3 times out of 4. Specific antibiotherapy does not charge the prognosis of the extrarespiratory manifestations, for which an immunologic mechanism is likely.

Antibodies, Bacterial↗

PubMed1985

[Retroperitoneal fibrosis and generalized scleroderma].

A Raynaud's phenomenon was observed in a 72 year-old man affected by progressive systemic sclerosis. Few months later, the patient was readmitted to the Hospital because of acute renal failure, and a retroperitoneal fibrosis was first suspected on the basis of typical urinary tract alterations, and subsequently confirmed at the post-mortem examination. Such association does not appear fortuitous on histological data, but it has been rarely described. HLA B27 antigen is not always present. Symptomatic therapy includes association between prednisone and percutaneous nephrostomy.

Aged↗