Presence of blood group H antigen on a carcinoembryonic antigen, and its enzymatic modification into blood group A and B specificities.

A carcinoembryonic antigen (CEA-M) was purified from a hepatic metastasis obtained from a blood group O patient with cancer of the rectum. Using 125I-labeled carcinoembryonic antigen (CEA) and blood group antisera, H specificity has been found on the CEA-M. As the addition of anti-H to anti-CEA does not modify the extent of binding of labeled CEA-M to its antibodies (86%), the H and CEA determinants are carried by the same molecule. The affinity chromatography of CEA-M on an immunosorbent "anti-H-Sepharose" demonstrated that a proportion of CEA-M molecules might bear both H and CEA antigenic determinants. In addition, glycosyltransferases were used to modify the blood group H specificity into blood group A or B specificities.

Cordycepin and early effects of estradiol on the immature rat uterus.

Estradiol induces the synthesis of a specific protein fraction (IP) in the uterus of the immature rat. The injection of cordycepin (3' deoxyadenosine), an inhibitor of poly A synthesis, inhibits the synthesis of IP. This fact suggests that one of the earliest effects of estrogen is the production of Hn-RNA poly-A relative to IP. Moreover, using electron microscopy, the stimulation by estradiol of the nucleolus of the immature rat uterine epithelium has been shown. Cordycepin does not affect this stimulation to any appreciable extent. Biochemical studies (incorporation of radioactive stracers into NRA, affinity chromatography on poly U-Sepharose) carried out in parallel with and under conditions comparable to those used in electron microscopy show that cordycepin does not greatly affect the increase in ribosomal RNA observed under the effect of estradiol. The blocking of IP by cordycepin and the lack of inhibition at the nucleolus level under the same conditions, show that the two early effects of the action of estrogen on the immature rat uterus are not directly correlated.

Enzymatic modification of the transplant antigens (ABO system) on human tumor cells.

Blood group glycosyltransferases were used to modify HeLa cells of H specificity (O Group) into cells of A and B specificity. We also obtained the identical type of modification with lymphocytes from healthy subjects and leukemia patients. This method can be applied to tumor cells in general, and constitutes an attempt to stimulate the immunocompetent system.

[Presence of the H blood group antigen on a carcinoembryonic antigen (CEA). Enzymatic transformation of H to A and B specificities]. / Présence de l'antigène H de groupe sanguin sur un antigène carcino-embryonnaire (CEA). Modification enzymatique de la spécificité H en spécificité A et B

The carcinoembryonic antigen (CEA-M) was purified from a hepatic metastasis obtained from a blood group O patient with a cancer of the rectum. Using 125I-labelled-CEA and blood group antisera, H specificity was found on the CEA-M; the addition of anti-H to anti-CEA does not modify the binding of labelled-CEA-M to its antibodies (86%), this result leads us to conclude that H and CEA determinants are carried by the same molecule. However the low percentage of binding (30% with 1/10 anti-H) suggests that only a few CEA-M molecules do carry the H antigenic determinant. Finally, glycosyltransferases were used to modify the H specificity into blood group A and B specificities.

[Fluorescence study of lymphocyte plasma membranes]. / Etude par fluorescence des membranes plasmiques de lymphocytes

ANS binding parameters--dissociation constant, number of binding sites, rotation freedom--are measured by fluorescence studies of a complex between ANS and lymph node cell plasma membranes. Divalent ions, Mg++ and Ca++, enhance the complex fluorescence intensity without shifting its maximum wavelength : this enhancement is induced by affinity and quantum yield increases, while the number of binding sites remains constant. The complex fluorescence quenching by ethacrynic acid shows the presence of free SH groups in the ANS binding site. An energy transfer takes place between membrane protein tryptophan residues and bound ANS ; the energy transfer yield is unaffected by Ca++ ions. A correlation of these results is postulated with the biological activity of the membrane.