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Biomedical subjects

L Gattegno

Publications and source records attributed to L Gattegno.

67 records · Page 4Linked to original sources
PubMed1978

Effects of ageing, surface sialic acid and glycopeptides of erythrocytes on auto-rosettes in man.

Human red blood cells can bind in vitro to autologous peripheral blood lymphocytes forming auto-rosettes. The percentage of rosett-forming cells (A-RFC) depends on erythrocyte ageing in vivo. Old untreated cells given an A-RFC percentage lower as compared with the young ones. The same age groups of cells treated with neuraminidase show a parallel increase of A-RFC as compared with untreated cells. No significant difference is found between young and old cells with high concentrations of neuraminidase. The rosetting formation is inhibited by the pre-treatment of lymphocytes with erythrocyte glycopeptides released by trypsin. This suggests that auto-rosetting is mediated by erythrocyte surface glycopeptides in which sialic acid plays a role directly or not.

ABO Blood-Group System↗
PubMed1977

Carbohydrate content of human red cell membrane in patients with cirrhosis of the liver.

The protein and carbohydrate contents of red cell membranes from 12 patients with liver cirrhosis were compared to those from 12 normal donors. Protein content was significantly higher and surface sialic acid and neutral hexoses were similar, whereas surface fucose and hexosamine were significantly lower in the cirrhotic red cells. The role of these membrane modifications is discussed.

Blood Proteins↗
PubMed1976

Changes in carbohydrate content of surface membranes of human erythrocytes during ageing.

The carbohydrate content (neutral hexoses, fucose, sialic acid, and hexosamine) of human erythrocytes is significantly higher in young than in old erythrocytes. The differences observed in the carbohydrate content of surface glycopeptides, obtained after incubation with either Pronase or trypsin, is still more striking, suggesting important modifications of the carbohydrate moeties of the erythrocyte membrane during in vivo ageing.

Carbohydrates↗
PubMed1975

Antibodies against myoid thymic cells and striated muscle, and monoclonal gammapathy in myasthenia gravis.

The serum of a patient with myasthenia gravis contained a particularly high titer of antistriated muscle antibodies, as well as a monoclonal IgM Kappa immunoglobulin. The antibody activity was only associated with IgG fractions and not with the monoclonal IgM, when these immunoglobulins were separated by chromatography. The association of these two immunological disorders is discussed.

Aged↗
PubMed1975

Significance of spontaneous autorosettes in rats.

Between 10(3) and 10(4) auto-rosette-forming cells (RFC) per 10(6) lymphocytes are observed in lymphoid organs of normal rats in vitro. Counts are significantly higher in the thymus than in other organs. Contrary to what has been previously described in mice, auto-RFC are not inhibited by fresh normal rat serum. The data presented are compatible with the hypothesis that auto-RFC differ from the lymphocytes which recognize only alloerythrocytes according to histocompatibility differences. There is evidence which suggests that autorosette formation is linked to the expression of new determinants on ageing erythrocyte membranes.

Age Factors↗
PubMed1975

Ageing in vivo and neuraminidase treatment of rabbit erythrocytes: influence on half-life as assessed by 51Cr labelling.

Old and young rabbit erythrocytes, separated by centrifugation, contained different respective activities of glucose-6-phosphate dehydrogenase, pyruvate kinase and acetylcholinesterase, and different quantities of stromal sialic acid. A systematic study of the survival rate of young and old erythrocytes incubated with different amounts of Vibrio cholerae neuraminidase is described. The half-life of intact old erythrocytes is significantly shorter than that of young erythrocytes with a similar sialic acid content.

Animals↗
PubMedDate not supplied

Sodium phenylacetate (NaPa) induces modifications of the proliferation, the adhesion and the cell cycle of tumoral epithelial breast cells.

Sodium phenylacetate (NaPa), a physiological product of phenylalanine metabolism, present in micromolar concentrations in human plasma, has been shown to induce in vivo and in vitro cytostatic antiproliferative effects at millimolar concentrations. Cadherin molecules are powerful invasion suppressor molecules and the reduction of E-cadherin expression plays an important role in the invasion and metastasis of human breast cancer. In this study, we demonstrated, on one hand, that NaPa stimulated aggregation by increasing the expression of E-cadherin at the surface of breast cancer MCF-7ras cells transformed by Ha-ras oncogene and inhibited its expression in MCF-7 cells. We demonstrated that NaPa increased the formation of MCF-7ras cell aggregates and did not alter the formation of MCF-7 cell aggregates. By Northern blot, we demonstrated that the E-cadherin expression was not regulated at the transcriptional level. On the other hand, we analyzed the cell cycle of these 2 cell lines after NaPa treatment and showed that NaPa induced arrest at the G1/S phase in both MCF-7 and MCF-7ras cells. bFGF increased the growth of MCF-7 cells, but inhibited MCF-7ras cell proliferation. NaPa treatment suppressed the stimulation of MCF-7 cell proliferation and increased MCF-7ras cell growth inhibition. We have demonstrated a new target of NaPa action in blocking the cell cycle of tumor cells in G0/G1. We suggest that the anti-proliferative effect of NaPa associated to the restoration of the cadherin function in human mammary carcinoma cells indicates that NaPa could be a novel therapeutic agent in breast cancer.

Adenocarcinoma↗
PubMedDate not supplied

[Plasmodium chabaudi: changes in the surface sialic acids of red blood cells during infection (author's transl)].

Surface sialic acids of mice red blood cells infected with the malarial parasite Plasmodium chabaudi are increased as compared to extracts of red cells from normal mice. This increase occurs coincidentally when reticulocytes increase in the peripheral blood. The same increase of surface sialic acids is shown by studies of reticulocytes from phenylhydrazine treated mice. Similarly, neutral hexoses, fucose, were found in greater quantities in surface glycopeptides obtained after incubation with trypsin of reticulocytes from phenylhydrazine treated mice than in surface glycopeptides of red cells from normal mice. This increase occurs also in Plasmodium chabaudi infected red cells with the development of reticulocytosis, in the same way. These facts suggest the contribution of reticulocytes to the biochemical changes observed during malaria infection.

Animals↗