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F Ria

Publications and source records attributed to F Ria.

25 records · Page 2Linked to original sources
PubMed1994

Monoclonal antibody 35.8 recognizes human, mouse and rat MnSODs in western blot and immunostaining.

MnSOD is an antioxidant enzyme whose decrease in activity appears involved in tumorigenesis. We had previously reported the production of a monoclonal antibody, named 35.8, against rat MnSOD. In the present paper we show that it recognizes human and mouse MnSODs, although with different detection limits. We also use the antibody for immunofluorescence studies and observed that the antibody yields a positive staining of a non-nuclear protein, in rat and human organs where high concentration of MnSOD activity have been reported, and a lack of staining in rat kidney where MnSOD activity is decreased. Two tumors, an experimental rat hepatocarcinoma and a human liver metastasis from a gastrointestinal adenocarcinoma, are found negative for immunostaining.

Adenocarcinoma↗
PubMed1993

Preparation of a monoclonal antibody against rat MnSOD, using a COOH-terminal peptide.

In the present paper we report the production of a monoclonal antibody against rat MnSOD, a supposed tumor-suppressor protein, using a purified synthetic peptide encompassing amino acids 184-198 to immunize mice, without conjugation to a carrier. The resulting antibody is able to recognize the native form of the protein, since it can immunoprecipitate the MnSOD activity in rat liver homogenate. In Western blot studies, the antibody recognizes a protein of 24 KD M(r), whose concentration varies according to the MnSOD activity and it apparently recognizes also human and mouse MnSODs. The protocol of immunization gives high yield of secreting lines. This monoclonal antibody will allow the detection of structural and functional alterations of MnSOD.

Amino Acid Sequence↗
PubMed1990

Immunological activity of covalently linked T-cell epitopes.

Immune responses to proteins necessarily involve the recognition by T lymphocytes of a peptide or peptides derived from a protein complexed with a major histocompatibility antigen. The T-cell response of BALB/c mice to the bacteriophage lambda cI repressor protein (residues 1-102) is directed predominantly towards the epitope contained within a single peptide encompassing residues 12-26. Similar phenomena of immunodominance of a particular peptide have also been observed in other protein systems. The mechanisms that have been suggested to account for the focusing of the T-cell response are partial deletion in the T-cell repertoire, biased antigen processing, and competition for binding to the presenting molecule, the major histocompatibility complex encoded class II transplantation antigen. In a model system with a polypeptide containing two synthetically linked immunologically active epitopes, we now demonstrate the existence of a hierarchy between these epitopes, so that the immune response elicited is directed mainly towards the more immunogenic epitope, whereas the less immunogenic epitope elicits little or no T-cell reactivity. In addition, the same hierarchy of dominance is also apparent when the polypeptide is used to induce tolerance in the periphery in adult mice. The chimaeric peptide can induce tolerance only towards the more immunogenic epitope. These experiments indicate that the rules governing antigen processing and presentation that result in T-cell activation are apparently the same as the rules that govern the processes resulting in the induction of tolerance.

Animals↗
PubMed1988

Chromatographic and electrophoretic studies of immune complexes in non-A, non-B hepatitis.

Immune complexes isolated from two patients with chronic non-A, non-B hepatitis, one patient with acute non-A, non-B hepatitis and one patient with juvenile rheumatoid arthritis were examined by means of a combined chromatographic and electrophoretic method. Both analyses showed the presence of complexes consisting of IgG, IgM, complement c1q factor and albumin; no antigen constituents were detected. The IgG-to-IgM ratio varied from 1:1 to 4:1, suggesting that one could be dealing with complexes of both IgG-IgM and IgG-IgG types. Moreover, the detectable presence of c1q factor might indicate that such complexes were capable of activating complement.

Antigen-Antibody Complex↗
PubMedDate not supplied

[Essential mixed cryoglobulinemia with liver involvement: a still open problem].

Essential mixed cryoglobulinemia (EMC) is a syndrome characterized by cryoglobulinemia and clinical features including purpura, arthralgia, asthenia (Meltzer-Franklin syndrome) without evidence of any systemic disease Liver involvement in the course of EMC is described in 50-84% of patients. It consists of mild silent hepatosplenomegaly and slightly rise of serum amino transferase. Eleven patients with clinical and laboratory findings suggestive for EMC (five type II and six type III) underwent percutaneous liver biopsy to evaluate the degree of liver involvement. Two liver cirrhosis, two chronic active hepatitis, one chronic persistent hepatitis and a case of hepatic steatosis were found. A type III cryoglobulinemia was present in four of the six patients with liver involvement. All the patients were Hbs Ag negative but three of them were Hbs Ab positive. The pathogenesis of liver involvement in the course of EMC is still now uncertain. The authors believe that a previous HBV infection plays no role in the pathogenesis of EMC syndrome. This syndrome must be considered different from mixed cryoglobulinemia secondary to chronic liver disease. They suggest that liver biopsy is mandatory during the course of EMC even when clinical and laboratory data are silent.

Aged↗