Localization of carcinoembryogenic antigen (CEA) in normal, inflammatory and neoplastic colonic mucosa by immunofluorescence.

To evaluate the role of tissutal carcinoembryonic antigen (CEA) in different types of colonic mucosae specimens from normal, inflammatory and neoplastic tissues were examined in immunofluorescence (IFL) with a monospecific CEA antiserum. Neither the pattern of IFL nor the amount of antigen in the tissue (defined as the antiserum dilution beyond which CEA staining was no longer visible), could reliably distinguish any histological entity a consistent overlap being observed between positive and negative results in malignant and non malignant mucosa. No correlation was found betwen IFL and the level of serum CEA. It is concluded that the tissutal localization of CEA by immunohistochemistry plays no role in the differential diagnosis of different types of colonic mucosa.

Effects of an antitumor multipeptide complex on immunocompetent and antigen-responsive cells.

The investigations, performed to study the possible mechanism of action of PTC, of its single constituents and of meta-levo-sarcolysin (m-L-SL) on the human immunocompetent system, are reported. The study entailed the evaluation of the effect of PTC, of its peptides and of m-L-SL on the various lymphocyte classes, employing all the more sophisticated immunological techniques such as: a) lymphocyte cultures stimulated with the various mitogens, (T and B lymphocytes); b) E rosettes (T lymphocytes); c) EA rosettes (lymphocytes with Fc receptors for IgG); d) EAC rosettes (lymphocytes with the C3 receptors); e) autoradiography and intracytoplasmic immunofluorescence (in vitro immunoglobulin neosynthesis); f) CdL (Complement-dependent Lymphocytotoxicity); g) LALI (Lymphocyte Antibody Lymphocytolytic Interaction); h) CML (antibody independent cytotoxicity i.e. Cell-Mediated Lympholysis). The evidence points out that the PTC effect on T and B lymphocytes is not comparable to that of m-L-SL which does not discriminate between the two lymphocyte populations while PTC, besides showing a scarce immunodepressive effect, preferentially affects B lymphocytes rather than T lymphocytes as shown also by the E rosette pattern. Significantly different appears also the influence of PTC, as compared with that of m-L-SL on the lymphocytes with Fc receptors for IgG (EA rosettes) and with receptors for the third component of complement (EAC rosettes) as well as on the cytotoxicity test and on the antibody dependent (LALI) and complement dependent (CdL) lytic effect. The data gleaned from this investigation allow evaluating both the effects of PTC on the immunocompetent system and the difference of its action from that of m-L-SL.

Significance of the presence of the various subtypes for the preparation of HBAb.

The superficial Australia antigen is essentially bound to the small particles and possesses different antigenic specificities 'a', 'd', 'g', 'w', and 'r'. The population which we tested was characterized by the major frequency (more than 90%) of the 'ag' subtype with respect to the 'ad' subtype. The doses have been achieved using the solid phase RIA, modified according to Ling, in which the specificity of the antisera anti 'a', 'd' and 'g' was obtained by means of the absorption and dissociation of the antigen-antibody complexes. The investigations which we carried out to establish the avidity of the various anti-HBs anti-sera used for research into the Au antigen, have established that in general the avidity is maximal for the anti-ad and minimal or absent for the anti-ag. From this arises the necessity for the preparation of an anti-HBs anti-serum 'pool' consisting of healthy and hepatitic donors, with an optimal relationship between the subtypes 'ad' and 'ag'. The subsequent research carried out using the true subtypes in order to establish a relationship between the subtype and the presence of the anticore antibody on RIA revealed the lack of any correlation.

Purification and characterization of the 'core' particles and their potential diagnostic use.

The basis of the postulated correlation between 'core' particles and 'Dane' particles, of their different localization in the hepatocyte and of the different relationships is the mechanism of replication of the infecting material, interesting diagnostic possibilities appear evident in the hepatitis B field. Anti-core antibodies would be alone present in the serum of the hepatitic patient, in the acute or convalescent stage, whilst in the serum of the polytransfused patient they would appear in association with the antibodies directed against the superficial antigen of the Dane particles. The 'core' particles have consequently been concentrated and purified by means of 'coat' lysis using tension actives and density gradient ultracentrifugation. With such material and a hepatitic serum purified antibody, it has been possible to prepare a radioimmunoassay with which a 'screening' may be performed to evaluate the possible diagnostic use.