Biomedical subjects
Publications and source records attributed to P Rouger.
Lewis blood group specificities are detected in the liver Fluke: Fasciola hepatica. Such specificities had never been reported in nature, other than in the human body. The investigation of this phenomenon might contribute to a better understanding of the mechanisms involved in parasite-host relationship.
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The levels of A, H, I and i antigens were measured in the plasma of 185 normal subjects by the agglutination-inhibition method. The presence of H in the plasma was only detectable with immune anti-H. The level of H in the plasma was directly correlated with the amount on the red cells, and was affected by the donor secretor status. The plasma of group O secretors contained more H than the plasma of donors of other phenotypes. On the other hand, I and i plasma antigens were not related to the other systems studied. Unlike the Ii antigens on the red cell membrane, there was no relationship between the levels of I and i in plasma.
The levels of A, H, I, and i plasma antigens and of anti-B, anti-I, and anti-T antibodies were measured in 70 subjects with colonic or gastric carcinoma. These studies showed a significant increase in A plasma activity of the A subjects, and in H plasma activity of the O subjects, while 25% of the tested subjects showed increased I plasma activity. There was no difference in i plasma activity between cancer patients and healthy subjects. These results take into account the marked polymorphism acquired by neoplastic tissue, which is capable also of producing a greater quantity of antigens than that of healthy subjects. Nevertheless this heterogeneity forms a barrier to the clinical measurement of these plasma antigens for screening neoplasms. The significant fall in the amount of anti-T antibodies seemed to be secondary to the absorption of these antibodies on the surface of the tumour cells.
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Enthalpy change was determined for natural anti-A (B, O subjects) and anti-B (A1, A2, O subjects). Entropy change, free energy change and association constant were calculated according to the law of mass action and the Wurmser method. The concentrations of allohaemagglutinins were measured by the Wilkie and Becker method using an autoanalyser. 2-Mercaptoethanol was used to estimate the proportions of IgG and IgM and their respective contribution to the thermodynamic properties. The following results and conclusions were obtained. Individual enthalpy and entrophy changes are different for each subject so that only the average values of these thermodynamic parameters represent a characteristic of the phenotype. There is a correlation between enthalpy and entropy changes and the relative proportion of anti-A or anti-B IgG. There is heterogeneity of the values of association constant. Free energy change is about 10 kcal mol-1 for all anti-A and anti-B; this result confirms the low energy binding between antigen and antibody. All these results confirm the role of environment and red-cell phenotype in the synthesis of allohaemagglutinins.
Many thermodynamic assays on natural allohemagglutinins ABO were undertaken by different authors. Our experiment concerns anti-A and anti-B. The allohemagglutinins level was determined by the Probit Method, using bromelin red blood cells and methyl cellulose, with an autoanalyser. This thermodynamic assay was carried out in almost the same conditions as those used by Wurmser. The data reveal an intraphenotypic (anti-A) or intra genotypic heterogeneity (anti-B) in the repartition of affinities. Average enthalpy changes are, in this methodology, interphenotypic (anti-A) and intergenotypic (anti-B) features. For Wurmser every genotype has a typical feature: so this author concludes a natural agglutinin homogeneity. Heterogeneity showed by our experimentation seems bound to the specific IgM and IgG repartition of each serum. Specific anti-A or anti-B IgM are more exothermic than specific IgG. The apparent disagreement must be interpreted owing to the fact that in N4 Wurmser's method, the only agglutinins determined are specific IgM.
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Crohn's disease with a predominantly pseudopolypoid presentation is a rare form. The inflammatory polyps are of highly variable topography. They may be located in the colon and the ileum. There are diffuse and localised forms. This pseudopolypoid form of Crohn's disease poses, in addition to diagnostic problems, pathogenic questions, integrating these findings within the context of nonspecific reactions of the colon, secondary to an ulcerating process which may be specific.
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