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Biomedical subjects

J Hilgers

Publications and source records attributed to J Hilgers.

At least 127 records · Page 7Linked to original sources
PubMed1985

AtT20 pituitary tumour cells contain mouse mammary tumour virus and intracisternal A-type particles in addition to murine leukemia virus.

By electron microscopy and immunocytochemistry we have examined the retroviruses endogenous to AtT20 D16V cells, a cloned line of murine pituitary tumour cells. In addition to the C-type retrovirus particles related to Rauscher murine leukemia virus (MuLV) previously reported to bud from these cells we observed cytoplasmic A-type particles and intracisternal A-type particles (IAP). In the cytoplasm the A-type particles occur in large clusters often associated with sheets of material with a fine structure resembling the shells of the particles. At the plasma membrane individual A-type particles bud to give rise to extracellular virions. The IAP are restricted to the rough endoplasmic reticulum (RER) into which they bud: they are not transported out of the RER to the Golgi apparatus and beyond. We describe a new monoclonal antibody (designated 83E7) which is specific for an epitope of the major core protein (MTVp27) of mouse mammary tumour virus (MMTV). Using immunogold labelling procedures we have specifically labelled both the A-type particles and the associated sheets of material with this antibody. We conclude that the A-type particles and the virions they give rise to are MMTV. The sheets of material must also at least in part be made up of the major core protein of MMTV or its precursor polypeptide. AtT20 cells, therefore, contain endogenous MuLV and MMTV as well as IAP.

Animals↗
PubMed1985

Prognostic value of surface antigens in primary human breast carcinomas, detected by monoclonal antibodies.

Three monoclonal antibodies, raised against human milk fat globule membranes, have been applied to 194 primary human breast carcinomas. The detected antigenic sites were found to be heterogeneously distributed. A statistical association with estrogen receptor content and grade of anaplasia was found for two of the antigens, Mam 3a and Mam 3b. The presence of all three antigens was independent of menopausal status, age, primary lymph node metastases, and progesterone receptor status. Life table analysis showed a better survival for patients with tumors positive for Mam 3b. The effect of these variables on recurrence-free survival has been analyzed using a Cox regression model. It is found that the most important prognostic factors are the number of positive lymph nodes, the estrogen receptor content, and the menopausal status of the high-risk patients. The ability of a model based on these factors to predict recurrence is not significantly improved by including any of the three surface antigens.

Antibodies, Monoclonal↗
PubMed1985

Mouse strain (STS/A) resistant to mammary tumor induction by hypophysial isografts.

Implantation of hypophysial isografts does not lead to induction of mammary tumors in all strains of mice lacking the exogenous murine mammary tumor virus. While O20, C3Hf, and BALB/c females are highly susceptible and C57BL and TSI females are of intermediate susceptibility, the STS females appear to be nearly totally resistant. The resistance of the STS strain is not due to failure of prolactin production by the hypophysial isografts and may therefore be due to a genetically controlled mechanism at target cell level. Neither resistance, i.e., low incidence of mammary tumors (2% in STS), nor susceptibility, i.e., high incidence at low age (93% at 349 days in C3Hf; 83% at 360 days in BALB/c), is dominant. F1 hybrids of strain STS and the two strains C3Hf and BALB/c show high incidences (STS X C3Hf F1, 90%; STS X BALB/c F1, 60%), but the age at which tumors appear (476 and 604 days, respectively) is much higher, suggesting that more than one gene is involved in this type of hormonal carcinogenesis of the mammary gland in mice.

Animals↗
PubMed1984

Molecular characterization of a membrane protein by a simple immunobinding procedure with monoclonal antibodies.

A simple immunobinding procedure for the detection and molecular characterization of antigens is described. Antigen is adsorbed by immobilized antibodies, and this is followed by radiolabeling with iodine. Both adsorption and radioiodination are carried out in microtiter wells. After gel electrophoresis and autoradiography the apparent molecular weight of the radiolabeled antigen may be estimated. With this procedure we show that 2 monoclonal antibodies, directed against different determinants, both detect a glycoprotein with an apparent molecular weight of 170,000. By a 2-site sandwich immunoassay we demonstrate that these antibodies detect the same glycoprotein.

Animals↗
PubMed1984

Gastrointestinal cancer-associated antigen (GICA) immunoreactivity in colorectal carcinoma in relation to patient survival.

Immunoreactivity of gastrointestinal cancer-associated antigen (GICA) was studied in tissue sections of 311 colorectal cancer patients and the results were correlated with data on patient survival. The group of uniformly GICA-positive tumours (10.6%) tended to behave more aggressively than focally positive (53.4%) and GICA-negative tumours (36.0%), also when stratified for stage of tumour extension and histological grade. This trend, however, did not reach statistical significance, perhaps as the result of a bias introduced by the relatively small number of GICA-positive cases. There appeared to be no significant difference in clinical course between patients with GICA focally positive or GICA-negative tumours (together comprising 89.4% of the total population studied). Further studies including a larger number of patients and longer follow-up periods are needed to validate the suggestion that GICA-positive colorectal carcinomas might show a more aggressive behaviour than tumours displaying other modes of GICA expression. However, the results of our study suggest that GICA immunoreactivity in colorectal carcinoma tissue is unlikely to be a sensitive, independent parameter for the prediction of prognosis in individual patients.

Antibodies, Monoclonal↗
PubMed1984

Monoclonal antibodies against human milk-fat globule membranes detecting differentiation antigens of the mammary gland and its tumors.

Mouse monoclonal antibodies have been raised against human milk-fat globule membranes (HMFGM) to obtain reagents for mammary tumor diagnosis. A panel of 17 anti-HMFGM antibodies was selected for further investigation. Antibody-blocking studies indicated that with these antibodies at least nine different non-overlapping epitopes could be distinguished on six different molecules, MAM-1 to MAM-6. Electron microscopic studies of the cellular localization of the antigens detected by some of these antibodies revealed that they were present on the cell membrane mainly, on the microvilli, lining intercellular and intracytoplasmic lumina. The reactivity of the antibodies was studied on normal and tumor tissues and on in vitro cell lines. All antibodies reacted with the resting mammary gland while eight antibodies also bound to breast tumors. None of the antibodies was specific for the mammary gland or its tumors only, but most antibodies also reacted with other epithelial cells, especially of secretory tissues. When tested on a variety of cell lines a distribution reflecting the tissue distribution could be demonstrated. One of the antibodies reacted with nearly all carcinomas and their metastases and did not react with lymphomas, sarcomas, neuroblastomas, melanomas or nervous system tumors. The specificity of the antibodies, tested individually, was not sufficient for further differential diagnosis of the carcinomas, but when some of these antibodies were used in a panel they contribute to an important improvement of the diagnosis.

Antibodies, Monoclonal↗
PubMed1984

Use of a monoclonal antibody to distinguish between precursor and mature forms of human lysosomal alpha-glucosidase.

The maturation of lysosomal alpha-glucosidase in cultured human skin fibroblasts was studied using a monoclonal antibody that distinguishes between the precursor and mature forms of the enzyme. Monoclonal antibodies against alpha-glucosidase isolated from placenta were produced by the hybridoma technique [Hilkens et al. (1981) Biochim. Biophys. Acta 678, 7-11]. One of these monoclonal antibodies, that synthesized by clone 43G8, reacts with the mature forms, but not with the precursor form of alpha-glucosidase isolated from urine. By means of pulse-labelling studies, it could be shown that monoclonal antibody 43G8 does not react with either the intracellular or the secreted precursor of alpha-glucosidase from cultured human skin fibroblasts. However, the antibody does react with the intermediate and mature forms of alpha-glucosidase. Endocytosis of the precurosor of alpha-glucosidase from urine by fibroblasts is followed by its conversion to a form with lower molecular mass. After endocytosis urinary precursor alpha-glucosidase is converted to a form that binds to monoclonal antibody 43G8. The t 1/2 for this conversion is 2 h. The conversion is inhibited by addition of leupeptin to the culture medium. It is concluded that a thiol proteinase is involved in the maturation of alpha-glucosidase in fibroblasts and the appearance of the antigenic determinant for 43G8.

Antibodies, Monoclonal↗
PubMed1984

Specific localization of In-111-labeled monoclonal antibody versus 67-Ga-labeled immunoglobulin in mice bearing human breast carcinoma xenografts.

A murine monoclonal antibody reacting with more than 95% of all breast cancers was radiolabeled with In-111 and injected IP into nude mice bearing human breast carcinoma xenografts, together with Ga-67-labeled normal mouse immunoglobulin. Images were produced with a gamma camera in dual isotope mode. Tumors could be localized clearly with In-111-labeled specific monoclonal antibody, but improved visualization was obtained after computer-assisted subtraction of the image with Ga-67-labeled nonspecific immunoglobulin. The tumor-to-tissue contrast was improved from 2.3 to 5.9 after subtraction. Imaging with In-111-radiolabeled monoclonal antibody was superior to imaging with iodinated antibody. For the first time it was shown that images of two chemically related isotopes, Ga-67 and In-111, coupled to nonspecific and specific antibody, respectively, and simultaneously injected, can be subtracted to show the preferential uptake of the specific antibody in the tumor. As these isotopes are routinely used in clinical practice this technique may prove to be more practical for immunodetection of tumors in patients than existing imaging techniques.

Animals↗
PubMed1984

The influence of formalin and paraffin embedding on the immunohistochemical reaction of monoclonal antibodies applied to female breast tissue.

Monoclonal antibodies, raised against purified human milk fat globule membranes, were applied to human tissue and the corresponding antigenic determinants detected by an immunoperoxidase method. In human breast tissue, the presence of antigenic determinants was characterized by considerable heterogeneity although it is confined to epithelial cells and cannot be detected in non-epithelial areas. The effect of fixation and paraffin embedding on the reaction pattern was evaluated on tissue from 25 primary breast carcinomas. For each tumor, both frozen, acetone fixed and fixed, paraffin embedded tissue was available. Four of the eight applied antibodies could detect fewer positive cells in formalin-fixed tissue as compared to frozen, acetone-fixed tissue from the same tumor. The positive peroxidase reaction was better preserved after fixation in Lillie's solution. Treatment of formalin-fixed tissue with pronase did not give a better effect. Antibodies with preserved positive reaction in formalin-fixed breast tissue were applied to a range of epithelial and non-epithelial human malignant tumors of varying origin. A heterogeneous positive reaction could be detected in the majority of tumors derived from epithelial cells, but not in non-epithelial tumors.

Antibodies, Monoclonal↗
PubMed1984

Urethan-induced mammary tumorigenesis in a murine mammary tumor virus (MuMTV)-positive mouse strain: evidence for a keratinized nodule as an MuMTV-negative precursor lesion for squamous cell tumors.

Administration of urethan (CAS: 51-79-6; carbamic acid, ethyl ester) in the drinking water of breeding female mice of the murine mammary tumor virus (MuMTV)-positive DD/Tbr strain and the MuMTV-negative DDf strain induced so-called keratinized nodules, which were demonstrable in wholemount preparations of mammary glands. It also induced squamous cell tumors (also called adenoacanthoma) at an extremely early age. The keratinized lesions appearing in the lobular areas of the mammary glands showed heavy infiltration with lymphocytes and as such were very different from hyperplastic alveolar nodules, the preneoplastic lesions for adenocarcinomas. Immunoperoxidase tests with antibodies against the MuMTV revealed that positivity of normal mammary gland epithelium in the DD/Tbr strain was not found in the keratinized nodules, which was further evidence that in squamous cell tumorigenesis of the mammary gland the MuMTV is not expressed overtly even at an early stage in tumorigenesis, in contrast to the case with adenocarcinoma tumorigenesis. These findings substantiate previous conclusions that the MuMTV is not involved in chemical carcinogenesis of the mouse mammary gland.

Animals↗
PubMed1983

Monoclonal antibody (1116 NS 19-9) defined monosialoganglioside (GICA) in colorectal carcinoma in relation to stage, histopathology and DNA flow cytometry.

Immunoreactivity of 1116 NS 19-9 monoclonal antibody defined monosialoganglioside (gastrointestinal cancer-associated antigen, GICA) has been studied in a series of colorectal carcinoma patients of a multicentre prospective controlled trial in order to assess its correlation with parameters such as localization, stage histopathological characteristics and DNA flow cytometry. GICA could be detected in 60% of the carcinomas, but no correlation was observed between its status of immunoreactivity and any of the parameters studied. It is concluded that, though study of the expression of the monosialganglioside may be worth while in relation to fundamental aspects of behaviour of colorectal carcinomas, the significance of its immunohistochemical detection in a diagnostic or prognostic sense is limited.

Antibodies, Monoclonal↗
PubMed1983

Tissue and organ distribution of mammary tumor virus antigens in low and high mammary cancer strain mice.

Expression of mammary tumor virus (MTV) antigen was measured in a wide variety of organs and tissues of a series of high (GR, SHN, SHNf, DD, SLN, SLNf) and low (DDf, DDD, DDDf, KF, KFf, ddY, C57BL, BALB/c) mammary cancer strain mice. Tests were carried out by microimmunodiffusion (micro-ID) and immunoperoxidase tests on formalin-fixed tissues and radioimmunoassays in extracts for 2 viral proteins, MTVp27 from the viral core and MTVgp52 from the viral envelope. Organs with exocrine function, i.e. the mammary gland, salivary gland, coagulating gland and prostate, were mostly positive. The secretory epithelial cells of these organs showed viral antigen expression. Less positivity was encountered in brain, pancreas, stomach, urinary bladder, epididymis, uterus, thymus, spleen, lymph nodes and kidney, plasma and blood cell pools. Unexpectedly the uterus extracts showed MTV antigen expression, occasionally even by immunodiffusion, especially in mice of various DD stocks, but also in the GR strain. Another striking observation was the detection of MTV antigen expression in salivary glands in C57BL strain mice; most other organs of this strain (including the mammary glands) were negative. The implications of results of this extensive survey for MTV antigen expression are discussed for tumorigenesis by MTV of mammary gland and perhaps other tissues in the mouse.

Animals↗
PubMed1983

Distribution of monoclonal antibody-defined monosialoganglioside in normal and cancerous human tissues: an immunoperoxidase study.

The immunoreactivity of a monosialoganglioside antigen defined by monoclonal antibody 116NS19-9 (19-9) was studied in neoplastic and normal glandular and mucosal epithelia using an indirect immunoperoxidase method. In neoplastic mucosae, the antigen was detected in the majority of colorectal and endometrial carcinomas, predominantly in a focal staining pattern. A substantial proportion of gastric and pancreatic tumors and an occasional breast carcinoma also reacted with the monoclonal antibody. Expression of the monosialoganglioside in normal colonic mucosa appeared to be restricted to areas adjacent to tumor tissue. In gastric mucosa, the antigen was confined to some areas showing intestinal metaplasia. The antigen was also detected in the epithelium of normal mucosa of the gall bladder and endocervix, as well as in some ductal epithelia of the pancreas and salivary glands. Most other mucosae were negative for antigen expression.

Adenocarcinoma↗
PubMed1983

Specific selection of host cell glycoproteins during assembly of murine leukaemia virus and vesicular stomatitis virus: presence of Thy-1 glycoprotein and absence of H-2, Pgp-1 and T-200 glycoproteins on the envelopes of these virus particles.

Using the indirect immunoelectron microscopy technique, it was investigated whether during assembly of murine leukaemia virus (MuLV) and vesicular stomatitis virus (VSV), the glycoproteins (gp) Thy-1, H-2, Pgp-1 and T-200 present on the surface of BW5147 and BuEL4 leukaemia cell lines were incorporated into the virus envelopes. This work was done mainly with monoclonal antibodies against these gps to exclude the presence of antibodies against endogenous MuLV present in conventional mouse antisera. Thy-1 gps were incorporated into MuLV and VSV envelopes. In contrast, H-2, Pgp-1 and T-200 gps were excluded from the budding of both virus particles. To study whether the presence of Thy-1 gps on the viral envelopes is due to some lateral affinity of this molecule with viral gps, the physical association of Thy-1.1 antigens and MuLV antigens was studied with antibody-induced redistribution of both antigens on the BW5147 cell surface. Antibody-induced patching of the viral antigens did not result in co-patching of the Thy-1.1 antigens. In the reciprocal tests no co-redistribution of viral antigens with Thy-1.1 antigens was seen. These studies show that the presence of Thy-1.1 gp on the MuLV envelope cannot be due to a lateral affinity of this molecule with viral gps and that a selection of surface gps takes place during assembly of MuLV and VSV.

Animals↗
PubMed1983

Identification of a cellular receptor for mouse mammary tumor virus and mapping of its gene to chromosome 16.

Pseudotypes of vesicular stomatitis virus (VSV) containing envelope glycoproteins provided by C3H mammary tumor virus (MTV) instead of the normal VSV G-proteins were prepared and used to assay the presence of an MTV receptor on cells. The assay was specific as demonstrated by competition studies with excess MTV particles and neutralization of the pseudotypes with anti-MTV serum or monoclonal antibodies directed against MTV gp52. The MTV receptor was abundantly present on mouse cells but hardly detectable on nonmurine cells, including the Chinese hamster cell line E36. Somatic cell hybrids between E36 cells and GRS/A spontaneous leukemia cells (GRSL cells) and between E36 and GRS/A primary mammary tumor cells were made. The hybrids retained all Chinese hamster chromosomes but segregated mouse chromosomes. From the analysis of the isoenzymes and chromosomes of the hybrid cell lines we conclude that the gene for the receptor (MTVR-1) is located on mouse chromosome 16.

Animals↗
PubMed1983

Localization of a gene controlling the expression of the human transferrin receptor to the region q12 leads to qter of chromosome 3.

A monoclonal antiserum, 66-IG10, raised against human thymocytes was found to be directed against the human transferrin receptor. A panel of human X Chinese hamster somatic cell hybrids, in conjunction with the 66-IG10 reagent, was used to assign the gene(s) coding for the transferrin receptor to the q12 leads to qter region of human chromosome 3.

Animals↗