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Biomedical subjects

T Gentile

Publications and source records attributed to T Gentile.

At least 37 records · Page 2Linked to original sources

IgG asymmetric molecules with antipaternal activity isolated from sera and placenta of pregnant human.

The proportion of symmetric and asymmetric IgG molecules was studied in 10 mothers at delivery. IgG was obtained from peripheral blood and placental blood sera and by elution at 4 M KCl from placenta cell membranes. The percentage of symmetric and asymmetric molecules was determined in the IgG and in their corresponding F(ab')2 fragments by absorption to Con A-Sepharose. The presence of antipaternal antibodies was investigated by IIF and MC tests using paternal lymphocytes. The average percentage of asymetric IgG molecules in the sera was 24.4, which is about double the value of that found in normal subjects. In the IgG eluted from the placenta, the proportion of asymmetric IgG was much higher, averaging 44.4%. Antipaternal antibodies were detected in 5 mothers by IIF and MC and in two mothers only by IIF. In three mothers no antibodies could be detected. It was found that the concentration of antipaternal antibodies was about three times higher in the asymmetric IgG fraction than in the summetric one. Considering the percentage of asymmetric IgG molecules with antipaternal antigen specificity eluted from placenta and the possibility that they function as blocking antibodies, their participation in fetal protection is suggested.

Cytotoxicity Tests, Immunologic↗

[Effect of pre-treatment with pyridostigmine on the stimulation of growth hormone by clonidine and GRF].

The large availability of biosynthetic GH suggested the need to define the more accurate way to make diagnosis of GH deficit. Only one stimulation test by clonidine or insulin is not enough to define a GH deficit, and this because often it's possible to get "false negative" tests. The GH is regulated by the influence of GRF and somatostatin that respectively are under the adrenergic and cholinergic control, for this reason we studied how and in which measure a cholinergic agonist (pyridostigmine) acts on GH release during the clonidine and GRF stimulation tests. We studied the area under the curve (AUC), the peak and the mean of the value of GH after clonidine or clonidine and pyridostigmine, and after GRF or GRF and pyridostigmine: we got the following results: 191 +/- 71.33 (AUC), 5.42 +/- 1.68 (peak), 2.44 +/- 0.54 (mean) after clonidine stimulation test; 1048 +/- 442.37 (AUC), 19.5 +/- 10.15 (peak) and 7.96 +/- 3.2 (mean) after clonidine and pyridostigmine (p less than 0.01); 1499 +/- 887 (AUC), 21.1 +/- 11.8 (peak) and 11.11 +/- 6.6 (mean) after GRF test and 2370 +/- 332 (AUC), 31.4 +/- 3.49 (peak) and 18.22 +/- 3.27 (mean) after GRF and pyridostigmine. The pyridostigmine effect on the simulation by clonidine and GRF is able to potentiate the stimulation of GH and allowed a more accurate diagnosis of GH deficit.

Adolescent↗

Asymmetric Fab glycosylation in guinea-pig IgG1 and IgG2.

The presence of asymmetric antibody molecules has been investigated in both IgG1 and IgG2 subclasses of guinea-pig immunoglobulins. It was found that about 20% of the IgG1 and 10% of the IgG2 were of asymmetric type. The proportion was essentially the same in the sera of normal animals, animals hyperimmunized with dinitrophenyl-bovine gamma globulin (DNP-BGG) and Freund's adjuvant, and animals infected with Trichinella spiralis. In the case of animals immunized with DNP-BGG, no differences were observed in the proportion of asymmetric molecules between the specific antibodies and the IgG not specific for the immunizing antigen. It is concluded that the asymmetric glycosylation occurs to a different extent in each subclass and that it is not affected by the antigen specificity of the antibodies studied.

Animals↗

Asymmetrically glycosylated IgG isolated from non-immune human sera.

When human IgG or its F(ab')2 fragment purified from a pool of non-immune sera was passed through a Con A-Sepharose column, 12% of the molecules bound to concanavalin A. While 44% of Fab' and 72% of Fd' fragments obtained from F(ab')2 retained by concanavalin A and eluted with methyl alpha-D-mannoside bound to concanavalin A, the Fab' and Fd' fragments obtained from non-retained F(ab')2 and the L chains and Fc fragments did not interact with the lectin. Only Fd' fragment obtained from the F(ab')2 retained by concanavalin A inhibited the fixation of guinea-pig erythrocytes to concanavalin A. These results are similar to those previously observed for IgG antibodies of different animal species and indicate that partial asymmetric glycosylation is a general phenomenon that is not restricted exclusively to IgG molecules with known specificity.

Animals↗

Sport and growth.

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Adolescent↗