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Biomedical subjects

H Grossmann

Publications and source records attributed to H Grossmann.

At least 37 records · Page 2Linked to original sources
PubMed1984

Monoclonal antibodies to tumor-associated antigens.

Experience is described in applying monoclonal antibodies (Mabs) to immunohistology, epitope analysis on antigens, and radioimmunoassay. The antibodies (provided by international laboratories) used in the experiments described were directed to the mouse mammary tumor virus, a cell surface component of melanoma cells, several proteins of the human milk fat globule membrane (as markers for cell differentiation in breast cancers) as well as to Carcinoembryonic Antigen (CEA). At least three antigenic determinants were detected on CEA, which appeared as being expressed in different quantities in those organs producing CEA-like molecules (lung, spleen, normal colon mucosa, liver). By means of an inhibition radioimmunoassay for CEA, evidence was obtained that in the lung more than one cross-reacting antigen might exist, one of them of high molecular weight (about or more than 200,000 daltons). In immunoperoxidase tests, several antibodies to CEA were seen to react with pulmocytes and bronchus glands. Summarizing the experience, it is concluded that thorough characterization of monoclonal antibodies by more than one method is a prerequisite to their use for analytical or diagnostic purpose.

Animals↗
PubMed1984

Charge-reducing lymphokine activity in Concanavalin A-stimulated lymphocyte supernatants: preliminary biological and biochemical characterization.

Supernatants of Concanavalin A stimulated (active) and unstimulated (control) guinea pig lymphocytes were fractionated by gel filtration on Sephadex G-100 into four arbitrary fractions (F1-F4). Fraction F3 from active supernatant (m.w. range 40 000-15000 D) was found to cause significant slowing of guinea pig macrophages in cell electrophoresis at dilutions of 1 : 200 (expressed as aliquots of the unfractionated supernatants). Neither the other fractions of the active supernatant nor the respective fractions of the control supernatant revealed any significant mobility reduction of guinea pig macrophages in cell electrophoresis. This charge-reducing activity could be blocked by alpha-L fucose, but not by other related monosaccharides. It was shown to be lyophilizable, nondialyzable, adsorbable to guinea pig macrophages and stable at 253 K for several months. The possible relationship of the charge-reducing lymphokine(s) to guinea pig macrophage migration inhibitory factor (MMIF) is discussed.

Animals↗
PubMed1983

Among the human antibodies reacting with intracytoplasmic a particles of mouse mammary tumor virus, some react with MMTV p14, the nucleic-acid-binding protein, and others with MMTV p28, the main core protein.

Human IgG antibodies reacting in the indirect immunofluorescence test with clusters of intracytoplasmic A particles in mouse tissues were analyzed by means of both radioimmunoprecipitation and enzyme-linked immunoabsorbant assays. Generally, antibody-containing sera reacted with epitopes of p14, the nucleic-acid-binding core protein of mouse mammary tumor virus, corresponding to the protein Ap14 of intracytoplasmic A particles. Comparatively few sera reacted with epitopes of the main core protein p28 corresponding to the protein Ap28 of intracytoplasmic A particles. The two types of reactivity occurred independently of each other.

Cell Line↗
PubMed1983

Human lymphocyte response to CEA: titration of different CEA samples and neutralization experiments with monoclonal anti-CEA antibodies.

By means of the macrophage electrophoretic mobility technique a striking digestive system cancer-associated human lymphocyte response to CEA has been found during a large-scale study including tests in 499 individuals. The question to be answered by this study was whether this response is really CEA-specific. Titration experiments with 3 different CEA preparations in lymphocytes from 5 colorectal cancer patients showed that the threshold dose of CEA necessary to induce lymphocyte responses amounts to 50-100 ng CEA per ml and 10(6) lymphocytes, regardless of the CEA origin and its state of purity. The CEA specificity of the responses was proved by neutralization experiments with 3 CEA-specific monoclonal antibodies. When allowed to react with CEA before lymphocyte incubation, the MABs prevented CEA from inducing lymphocyte responses. Appropriate murine control myeloma protein did not influence these responses. The reactivity of these lymphocyte samples to a teratocarcinoma extract could not be prevented by treating this material with CEA-specific MABs before incubation. Preliminary attempts to enrich the lymphokine(s) released after CEA stimulation resulted in recovery of the activity within 2 arbitrarily cut Sephadex G-100 fractions comprising the mol. wt range of 3000-47,000.

Antibodies, Monoclonal↗
PubMed1983

[Discrimination of nonspecific effects in the macrophage-electrophoretic-mobility test using dimethyl sulfoxide].

Upon incubation with human encephalitogenic protein (HEP) blood lymphocytes from patients with malignant tumours release mediators (lymphokines) leading to a decreased electrophoretic mobility of guinea pig peritoneal macrophages. The lymphocyte supernatants used for incubating the macrophages contain HEP, nonspecific lymphocyte-derived proteins, and in case of sensitized lymphocytes also specific mediators. Whereas HEP or nonspecific lymphocyte products do not themselves exert any effect on macrophages, they produce a nonspecific mobility reduction when acting simultaneously. In the presence of 2.4% (v/v) dimethylsulfoxide (DMSO) this nonspecific effect is prevented. The specific lymphokine action, however, remains stable in the presence of DMSO. It cannot be decided whether DMSO exerts its effect via the membrane of macrophages or/and by influencing the interactions of proteins in the soluble phase.

Animals↗
PubMed1982

Sensitization of human lymphocytes to carcinoembryonic antigen (CEA): neutralization experiments with anti-CEA sera.

By means of the macrophage electrophoretic mobility technique we could show lymphocytes of patients suffering from cancers of the digestive system to be sensitized to carcinoembryonic antigen (CEA). These findings conflict with the common view that CEA is not immunogenic in humans. The aim of the present study was to look as to whether conventional anti-CEA sera can neutralize the activity of a CEA preparation which is responsible for the human lymphocyte response. When 60 ng CEA were preincubated with highly diluted anti-CEA serum and the resulting immune complexes were thereafter co-precipitated by protein A-sepharose, positive lymphocyte responses could no longer be obtained. This effect was observed with 3 anti-CEA sera in 3 cancer patients (colon cancer, stomach cancer, teratocarcinoma), who's lymphocytes responded to CEA by lymphokine release. Normal serum had no neutralizing effect. The anti-CEA sera did not influence the activity of another tumour-relevant extract (teratocarcinoma-derived), to which cancer patients' lymphocytes reacted regardless of the tumour site. The lymphocytes from an oesophagus carcinoma patient, though reacting to the teratocarcinoma preparation, did not respond to CEA, thus, logically, all other tests with normal serum and anti-CEA sera were negative, too. The results show that the digest system cancer-associated lymphocyte reactivity to CEA can be abrogated by conventional anti-CEA sera, which finding indicates that there exist closely CEA-associated "tumour-specific" antigenicities.

Animals↗
PubMed1982

Radioimmunological characterization of carcinoembryonic antigen (CEA) preparations.

A multi-step radioimmunological test system was applied to the characterization of carcinoembryonic antigen (CEA) preparations obtained by column chromatography including ion exchange procedure. CEA contents were estimated by means of a sequential inhibition radioimmunoassay using Protein A-bearing Staphylococci for coprecipitation. Data were expressed as "units CEA" and compared with results obtained from commercial CEA-RIA kits. In addition, attempts were made to evaluate the presence of normal cross-reacting antigens in CEA preparations by the application of an antiserum to perchloric acid extract from normal lung tissue. Data from these tests were expressed as "units NLA" (NLA stands for "normal cross-reacting lung antigen"). The factor "units CEA/units NLA" proved useful as an indication of the tumour specificity of those antigenic components measured in the inhibition assay. Moreover, radioimmunoprecipitation tests with subsequent SDS polyacrylamide gel electrophoretic analysis were performed in order to get information on the molecular weight of the molecule(s) involved in the radioimmunological CEA determination procedure. The test system displayed 1) highly specific CEA reagibility in the standard inhibition assay, 2) test sensitivity of about 200 pg CEA (when related to the Hoffman/La Roche test) and 1 ng CEA (when related to CEA-IRE-SORIN), 3) low reagibility to normal cross-reacting antigens, also when compared to the commercial tests, 4) a molecular weight of about 200,000 daltons for the component(s) measured, and 5) evidence of inhomogeneity of the CEA batches investigated and those international references available. The latter might in part be attributed to so-called species-specific CEA-related determinants. The test system proved also useful for CEA estimations in crude tissue extracts.

Animals↗
PubMed1982

Studies on lymphokine activity in concanavalin A-stimulated lymphocyte supernatants using the macrophage-electrophoretic-mobility-test (MEM-test).

Blood lymphocytes from guinea pigs and human donors were incubated with varying amounts of soluble Con A or, in the human system, with Sepharose-bound Con A for 60 min and 24 h at 310 K. The cellfree lymphocyte supernatants were incubated with guinea pig peritoneal macrophages which were measured in a cell electrophoresis apparatus "Parmoquant II" to detect lymphokine activity. Differences were found in the slowing capacity of short-term (60 min) and long term (24 h) incubations. In the latter mobility reduction was higher at comparable Con A concentrations. Greatest macrophage slowing was found at Con A concentrations of 5--10 micrograms Con A/10(6) lymphocytes in the guinea pig system and of 40--50 micrograms Con A/10(6) lymphocytes in the human system. But there was no great difference in the heights of the macrophage slowing at the optimal Con A concentration indicating no species restriction for human lymphokine(s) in our experiments. Stimulation of lymphocytes seems to be possible with Sepharose-bound Con A during a long-term incubation as tested in the human system.

Animals↗
PubMed1982

Reactivity of human lymphocytes to teratoma preparations as revealed by the macrophage electrophoretic mobility (MEM) technique.

By means of the MEM technique, the lymphokine release by human lymphocytes has been measured after exposure to 3M KCl extracts from malignant teratoma tissue. Clear-cut responses were found in 149 out of 171 cancer patients (87%) regardless of the primary cancer site. In contrast, only 15 out of 93 (16%) individuals from a control group without detectable malignant disease gave such a response. Subdivision of that control group showed, however, that only 1 of 46 healthy blood donors, but 14 of 47 (30%) hospital patients with benign tumours (7 of 19), inflammatory diseases or degenerative and metabolic disorders (7 of 28) reacted to the teratoma-derived material. It appears to be possible that malignant teratoma tissues contain a mixture of oncofetal or phase-specific antigens which correspond to the multifarious differentiation structures of the three germ layers developing in such tumours. If the lymphocyte response of tumour patients is due to the sensitization to analogous tumour-associated antigens in vivo, it remains to be clarified whether or not the less frequent lymphocyte response of hospital patients without neoplastic diseases may be directed to another quality of antigens.

Adolescent↗
PubMed1981

Reactivity in the MEM-test of cancer patients' lymphocytes incubated with brain-derived preparations and extracts from malignant teratomas.

A batch of human encephalitogenic protein (HEP) was compared to preparations of microtubulin and associated proteins (MST) from guinea pig brain by serological techniques and the macrophage electrophoretic mobility (MEM) method. HEP consisted mainly of A1 protein and MST showed the characteristic double band in the 55,000 MW region and some additional weak protein bands. No cross-reactivity could be detected between HEP and MST by rabbit hyperimmune sera to these substances. The MEM test, however, revealed human lymphocyte reactivity to HEP and MST in both cancer and multiple sclerosis patients, but no remarkable responses in other patients. A synthetic nonapeptide (114-122 region of A1 protein) led to lymphokine release in 2 of 5 multiple sclerosis patients, in 1 of 13 cancer patients, and in none out of 13 control individuals. From these findings it is concluded that a minor component (contaminant?) present in both HEP and MST might induce lymphocyte responses in cancer patients. The A1 protein of HEP preparations is, if at all, not the only protein responsible for the so-called HEP-response of cancer patients. Continuing the MEM test experiments with extracts from single organ cancers, it could be shown that patients with malignant teratomas respond to a more or less broad spectrum of extracts bearing organ cancer specificity. On the other side, extracts made from 2 malignant teratoma tissues led to MEM responses in 8 of 13 cancers, in 2 of 11 control persons and in none of 5 multiple sclerosis patients. These findings underline the concept that tumour-associated antigens (possibly oncofetal antigens) do exist, which bear organ cancer specificity and will lead to a specific sensitization of the host. Such antigens may be expressed in teratomas in different qualities and amounts depending on the tissue differentiation capacity of a given teratoma.

Cross Reactions↗
PubMed1981

Is there any diagnostic relevance of human antibodies which react with mouse mammary tumor virus (MuMTV)?

Applying an indirect immunofluorescence assay with prolonged serum incubation on frozen-cut mouse mammary tumor slices, antibodies are detectable in human sera which react with viral inclusion bodies consisting of intracytoplasmic A particles (iAp). These iAp are known to represent intracellular entities of the mouse mammary tumor virus (MuMTV), mainly related to MuMTV core constituents. In 1,449 women studied, the antibody incidence is partially correlated with proliferating changes of the mammary gland. However, epidemiological data obtained thus far have clearly shown that the detection of antibody is not useful in breast cancer diagnosis (antibody incidence in breast cancer patients 22.8%, in lactating women 20.6%, in controls 5.9%). Studying antibody reagibility to particular iAp polypeptides by means of a radioimmunoprecipitation (RIP) technique, there has been preliminary evidence that human serum factors react with more than one mouse virus protein. The most prominent reactivity was seen to be directed to the 14,000 dalton protein (Ap14). The detection of serum antibody activity is considered as being of important indicative value in that it reflects the existence of MuMTV-related antigens in man.

Animals↗
PubMed1981

Use of an electroimmunodiffusion method on cellulose acetate films for the detection of antigenicity in human breast cancers that is related to the major core antigen of mouse mammary tumor virus (MuMTV).

A highly sensitive electroimmunodiffusion method on cellulose acetate films, developed by Abelev on the basis of isotachoelectrophoresis, was applied to search of MuMTV-related antigenicity in tumor tissue and sera of breast cancer patients. In 2 out of 5 breast cancer extracts, protein fractions corresponding to a molecular weight of about 50,000 daltons were seen to exhibit antigenicity related to the major core antigen of MuMTV (p27). This antigenicity could not be detected in the sera of the patients.

Animals↗
PubMed1981

Preliminary characterization of a colon tumour tissue preparation used in macrophage electrophoretic mobility (MEM) test1.

A 3M KC1-extract on nine samples of colon carcinomas was freed from human serum proteins by immunoadsorption. Both the KC1-extract and the immunoadsorbed preparation of this KC1-extract were used in MEM test and gave characteristic reaction patterns. The two preparations were compared and preliminarily characterized by immunological and electrophoretical methods.

Antigens, Neoplasm↗
PubMed1979

Concerning the anchoring of acetylcholinesterase in biomembranes.

Highly purified acetylcholinesterases from various sources do not contain hydroxyproline and hydroxylysine, indicating the absence of a collagenlike 'tail'. The enzymes examined are therefore bound to the membrane in a different way compared with acetylcholinesterase isolated from electric organ.

Acetylcholinesterase↗
PubMed1979

[Purification by affinity chromatography and properties of the acetylcholinesterase of formosan cobra (Naja naja atra) venom (author's transl)].

The acetylcholinesterase was purified by CM-Sephadex chromatography and affinity chromatography on Sepharose bound m-[6-(6-aminocaproylamino)caproylamino]phenyltrimethylammonium bromide. The purified enzyme was obtained with a specific activity of 5470 U/mg (1160-fold purification) and a 89% yield. The molecular weight of the native enzyme was estimated to be 144,000. The enzyme is split into two subunits of approximately equal molecular weight (Mr 69,000) by SDS treatment. It is a glycoprotein and can be resolved by disc gel electrophoresis into seven and by isoelectric focusing into more than ten multiple forms. The N-terminal amino acid is serine.

Acetylcholinesterase↗
PubMed1977

Immunological tumour profile: organ-specific carcinoma diagnosis in patients employing the macrophage electrophoretic mobility test.

The macrophage electrophoretic mobility (MEM) test provides a highly sensitive in vitro technique for the detection of cell-mediated immunity in man. The principle involved is the lymphokine-mediated reduction of the negative surface charge of guinea pig macrophages shown by the slowing of the macrophages during cell electrophoresis. Lymphocytes from 162 patients were tested by MEM. They were exposed to a battery of KCl extracts from normal and malignant human tissues, to encephalitogenic protein (EP), to carcinoembryonic antigen (CEA), and to thyroglobulin. Variable lymphocyte responses to EP, CEA and KCl extracts from different cancers gave MEM reaction profiles common to patients with carcinomas of the same organ origin.

Antigens, Neoplasm↗