Purificación parcial de antígenos de menbrana para la obtención de antisueros que reconocen al melanoma B-16 / Parcial purification of membrane antigens for obtaining anti-sera recornizing melanma B-16

Se obtuvieron antisueros que reconocen selectivamente a melanocitos normales y malignos de ratón mediante 2 formas de inmunización: con cèlulas enteras del melanoma murino B-16 y con una fracción semipurificada de menbrana de dichas células. El reconocimiento de los antisueros fue ensayado por técnicas de ELISA e inmunofluorescencia contra melanoma y otros tejidos. Se concluyó que los antisueros obtenidos por inmunización con la fracción purificada presentaron un reconocimiento más especìfico de los melanocitos

Lymphoma associated antigen (LAA)--a unique biomarker for lymphomas.

A lymphoma associated antigen (LAA) isolated from pooled lymph nodes of confirmed Hodgkin's and non-Hodgkin's lymphomas has been purified and characterized. Using a xenogenic rabbit anti-serum, enzyme-linked immunosorbent assay (ELISA) and RIA were developed for LAA. LAA was detected in the sera of all confirmed lymphomas, the test being negative for normals, for patients with benign lymphadenitis and various other types of cancers. Except for a very few false positive results, no false negative was observed. LAA was identified in urine, CSF, saliva and gastric juice of a few lymphoma patients, and the test proved to be of diagnostic potential, as for a few patients it had a lead time of a few months over the histological diagnosis. In order to render the LAA test more precise and specific, monoclonal antibodies were generated by both in vitro and in vivo immunization procedures. Seven monoclonals were generated, viz. 7D6, 7D2, 7G2, 7C5, 6G2, 23B7 and 23G11, which exhibited cytoplasmic staining of frozen sections of malignant lymphoid tissues of B cell derived non-Hodgkin's lymphomas. Two of these monoclonal antibodies, 7D6 and 23B7, revealed strong cytoplasmic staining of frozen sections, impression smears and cytospin specimens of B cell non-Hodgkin's lymphomas. The reactivity was very weak or negative for T cell lymphomas. The test was negative for Hodgkin's disease and controls. These results were confirmed by dot blotting, immunoprecipitation and immunofluorescence study. By ELISA with a sensitivity of 15 ng/ml, serum LAA levels for lymphomas were in the range 72-1250 ng/ml. LAA could not be detected in the sera of normals and controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Valores totales de antígeno próstato específico y estadio clínico de cáncer prostático / Value of specific prostatic antigen and prostatic cancer status

Se presenta una experiencia inicial de 11 pacientes con cáncer prostático en quienes se efectuó medición de antígeno prostático específico sérico mediante RIA. Se encuentra una relación entre los valores y el estadio clínico, en estadio A = 2 - 8 ng/ml. en estadio D = 170 - 300 ng/ml. Hay una mayor sensibilidad del método al compararse con las fosfatasas ácidas. Hay descenso del antígeno prostático después del tratamiento del cáncer (trat. antiandrogénico, radioterapia y cirugía radical)

Factors Influencing the Pathogenicity of Entamoeba Histolytica

In summarizing the results of the experimental studies up to the present, it is conjectured that the pathogenicity of Entamoeba histolytica or establishment of amoebiasis is not unique but differs by strain and age of Entamoeba histolytica and the age of the host. A non-virulent strain is more likely adapt to as low a temperature as 32 . This is not so in the strains which originated form clinical cases. Iso-enzyme patterns may roughly characterize pathogenic strains from non-pathogenic, Red blood cells may contribute as nutrients for growth of Entamoeba histolytica only after they have been hemolysed, but they are toxic to the amoebae as long as they remains intact. A low protein diet and stress may facilitate the establishment of amoebiasis; male sex hormones or previous infection by enteric bacteria provide a more advantageous condition than the female; and hepatotoxic agents will accelerate amoebic hepatitis.

Characterization of Tumor Specific Antigens on the Plasma Membrane Surface of Rat Hepatomas lnduced by 3'-Me DAB and ldentification of the Common Tumor Specific Antigens from Rat Hepatomas lnduced by Different Chemical Hepatocarcinogens

Three different chemical carcinogens, 2-acetylaminofluorene (AAF), diethylnitrosamine(DENA), and 3'-methyl-4dimethylaminoazobenzene (3'-Me DAB) were used to induce hepatomas in rats. Plasma membrane surface proteins of normal rat liver cells and rat hepatomas were extracted with 3M KCI. From the analysis of the proteins of normal rat liver and rat hepatoma induced by 3'-Me DAB by discontinuous polyacrylamide gel electrophoresis(Disc-PAGE), under nonreducing and nondenaturing conditions polyacrylamide gel electrophoresis in the presence of SDS and 2-mercaptoethanol (SDS-PAGE), Sephadex G-200 gel permeation chromatography, DEAE-A50 ion-exchange chromatography and two-dimensional gel electrophoresis, at least three tumor specific antigens were identified. One had a molecular weigh of 66,000 (pl=6.79) while the other two had the same molecular weight 73,000 but differed in their isoelectric points (7.58 and 7.81). For immunological analysis of tumor specific antigens, the absorbed antiserum was prepared. Plasma membrane surface proteins of rat hepatoma induced by 3'-Me DAB were used to obtain New Zealand White male rabbit antiserum. Rabbit antiserum was then reacted with the proteins isolated from the plasma membrane surface of normal rat liver and the absorbed antiserum reacting specifically with the tumor specific antigens derived by 3'-Me DAB was obtained. Using the absorbed antiserum, the immunoreactivities of plasma membrane surface proteins isolated from rat hepatomas induced by 3'-Me DAB, AAF, and DENA were compared by Ouchterlony double immunodiffusion analysis and immunoelectrophoresis. To characterize the proteins reacting to the absorbed antiserum, immunoglobulin G was separated from the absorbed antiserum and coupled to cyanogen bromide-activated Sepharose CL-4B. The isolated proteins from the plasma membrane surface proteins of 3'-Me DAB-induced hepatoma using this immunoaffinity chromatography had molecular weights of 66,000 and 73,000. The localization of these proteins on surface plasma membranes of rat hepatomas induced by 3'-Me DAB was confirmed by an immunofluorescence technique. The experimental results revealed the existence of cross-reacting common antigens on the plasma membrane surface of rat hepatomas induced by different hepatocarcinogens.

Purification of r-Glutamyltranspeptidase from Rat Primary Hepatoma Tissue and Preparation of a Tumor Associated Antigen

r-Glutamyltranspeptidase (r-GT) from a rat hepatoma induced by 3'-methyl-4-dimethylaminoazobenzene (3'-Me DAB) was purified 833 fold. The purified enzyme had a specific activity of 15.0 U/mg protein with an overall yield of 3.8%. The molecular weight of native r-GT was estimated as about 350,000 daltons, whichs a multicomplex of a single polypetide having a M W of 59,000. Anti r-GT rabbit antiserum cross-reacted with kidney r-GT as well as liver r-GT. Tryptic digestion of r-GT followed by separation with Con A sepharose column chromatography resulted in two major glycopeptides. A tumor associated antigen was prepared by the conjugation of a tryptic glycopeptide of r-GT to keyhole limpets hemocyanin and an antibody against this antigen cross-reacted preferentially with r-GT in rat hepatoma tissue.