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Biomedical subjects

R Perego

Publications and source records attributed to R Perego.

At least 37 records · Page 2Linked to original sources
PubMed1988

In vivo immunopotentiating activity of thymopentin in aging humans: modulation of IL-2 receptor expression.

The effect of thymopentin treatment was investigated in immunocompromised elderly subjects. Thymopentin was able to increase IL-2 production and IL-2 receptor expression, as assessed on PHA-activated blasts by percentage of Tac-positive cells and response to exogenous IL-2. After treatment, an increased precursor frequency, estimated by limiting dilution analysis, of PHA-responding lymphocytes was observed in two out of six subjects tested. In vitro experiments with thymopentin show that the drug was able to enhance blastogenesis by PHA of elderly lymphocytes but not of adult cells. These results indicate that (a) the increased IL-2 synthesis/IL-2 receptor expression may be the crucial mechanism of the immunopotentiating activity of the drug in elderly subjects and (b) an increased intrinsic T-cell responsiveness seems to be responsible for this immunopotentiating activity, although an increase in the size of the responsive T-cell pool could not be excluded.

Adjuvants, Immunologic↗
PubMed1988

Anti-Epstein-Barr virus antibodies in systemic lupus erythematosus.

Sera from 18 patients with Systemic Lupus Erythematosus (SLE), 20 with nonA-nonB acute hepatitis and 19 healthy subjects were tested for the presence of antibodies to the viral capside of Epstein-Barr virus. In patients with SLE the mean titre of anti-VCA IgG was significantly higher than in normal subjects (p less than 0.02), and the percentage of patients with titres greater than 1:160 was significantly higher than in normal population (p less than 0.01). These high anti-VCA) titres in SLE patients are probably related to a defective immune surveillance.

Adolescent↗
PubMed1986

Effects of liver regeneration on tRNA contents and aminoacyl-tRNA synthetase activities and sedimentation patterns.

The tRNA content and aminoacyl-tRNA synthetases of regenerating liver in the phase of rapid growth were compared with those of livers from both intact and sham-operated rats. At 48 h after hepatectomy, the amount of active tRNA (called 'total acceptor capacity') is significantly higher in regenerating liver than in control livers, owing to a general, possibly not uniform, increase in the various tRNA families, which suggests that it may contribute to the increased protein synthesis and to decreased protein degradation as well. The activities of most, but not of all, aminoacyl-tRNA synthetases in cell sap of regenerating liver tend to be greater than normal. Increased activity of histidyl-tRNA synthetase fits in with the possibility that the mechanisms that control the rate of protein degradation through aminoacylation of tRNAHis in cultured cells [Scornik (1983) J. Biol. Chem. 258, 882-886] also operate in the liver and play a role in regeneration. Sedimentation analysis of cell sap in sucrose density gradients shows a shift of prolyl-tRNA synthetase activity toward the high-Mr form in regenerating liver. This change might be related to the positive protein balance and to growth in vivo, since it is also observed in the anaplastic Yoshida ascites hepatoma AH 130.

Amino Acids↗
PubMed1983

Isolation and characterization of circulating immune complexes in patients with rheumatoid arthritis.

We studied soluble immune complexes in sera and synovial fluids of ten patients suffering from Rheumatoid Arthritis (RA), six seropositive and four seronegative. Isolation of the immune complexes was obtained by a combination of gel filtration and affinity chromatography from biological fluids. The first step involved preparation of a globulin-enriched fraction by precipitation of either serum or synovial fluid with 5% polyethylene glycol 6000. The precipitate was solubilized in Borate NaCl buffer and fractioned by gel filtration in Ultrogel AcA 34. Eluted peaks were submitted to affinity chromatography on a Protein A-Sepharose CL 4B column. The recovered material was analyzed by double immunodiffusion and electrophoresis in 6-20% polyacrylamide gel containing sodium dodecylsulphate (SDS-PAGE) and was shown to contain IgG, IgM, IgA with small amounts of C1q, C3 and C4. Observation occurred that there is a different distribution of macromolecular and intermediate complexes in seropositive and seronegative samples respectively, total C1q binding activity being equal.

Antigen-Antibody Complex↗
PubMed1983

IgG rheumatoid factors behaviour in young normal subjects following vaccination.

In order to contribute to explain the finding of Rheumatoid Factors of the IgG class in all normal subjects, even at low levels, a study on their behaviour in a group of young subjects serving in the army, at the time of anti-typhoid and antitetanic vaccination, and in the following two months, was conducted. Parallely some aspecific serological parameters of autoimmunity were determined. The results demonstrate, first of all, a good antibody response to the vaccine in all subjects observed. Immunoglobulins of the IgG, IgA, and IgM class were normal in all samples. Complement factors C3 and C4 were slightly decreased after the second dose of vaccine, suggesting a modest consumption probably due to immune complexes formation. Factor C3A showed a slight increase, may be to be considered as its property of an acute phase reactant. Autoantibodies determined by immunofluorescence were constantly negative. IgM rheumatoid factors became transitory positive in a significant proportion. IgG rheumatoid factors demonstrated a two-phase increase, more evident after the second dose of vaccine. We can conclude, mainly for the latest parameter, that these results reveal an autoimmune serological response, even quantitatively modest, concomitant to the specific sensitization resulting from vaccination.

Adult↗