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Biomedical subjects

U Karsten

Publications and source records attributed to U Karsten.

At least 73 records · Page 4Linked to original sources
PubMed1988

A new monoclonal antibody (A46-B/B10) highly specific for the blood group H type 2 epitope: generation, epitope analysis, serological and histological evaluation.

A monoclonal antibody recognizing the blood group H type 2 antigen has been obtained from a BALB/c mouse immunized with MCF-7 (human mammary carcinoma) cells. The specificity of this antibody (A46-B/B10, IgM, kappa) has been identified by haemagglutination tests, immunohistochemistry, binding inhibition studies, and absorption experiments performed with synthetic oligosaccharides. The antibody is virtually nonreactive with H type 1 antigen or with closely related type 2 structures (e.g., Y antigen). A46-B/B10 strongly agglutinates human erythrocytes according to the amount of H substance expressed and can, therefore, easily discriminate between blood groups A1 and A2 as well as A1B and A2B (A1 and A1B are not or only weakly agglutinated). In immunohistochemistry, this antibody seems to provide a highly specific reagent for a restricted number of carcinomas and epithelial lineages in tissue sections and in vitro.

ABO Blood-Group System↗
PubMed1988

Direct comparison of electric field-mediated and PEG-mediated cell fusion for the generation of antibody producing hybridomas.

As an alternative to polyethylene glycol (PEG), electric field pulses offer, in theory, fusion conditions whose parameters are better controllable. In 1985 (1) we reported on the successful generation of hybridoma clones by means of electrofusion performed in a batch-type manner similar to that usually employed with PEG, and applicable to any type of antigens. Here we summarize the results of a series of fusions performed since then in which both electric field and PEG induced fusion were directly compared. Different types of antigens were used. Electrofusion resulted in a 3.8 to 33.0 times higher yield of hybridomas per unit number of spleen cells. Moreover, hybridomas grew more vigorously after fusion and, therefore, were earlier visible. Other parameters examined revealed no differences between hybridomas generated by either method.

Animals↗
PubMed1988

Expression of cytokeratin and vimentin in nucleus pulposus cells.

With immunohistochemistry using monoclonal antibodies against intermediate filament proteins, nucleus pulposus cells were found to express cytokeratin(s) simultaneously with vimentin in fetal life and childhood. This finding adds to the series of human tissues showing coexpression of cytokeratins and vimentin. Surprisingly remnants of such cells were also found in the nucleus pulposus of adults, and a possible relationship of such cells to chordoma formation is discussed.

Antibodies, Monoclonal↗
PubMed1988

[Immunohistochemical studies with monoclonal antibodies in human mammary carcinoma tissues].

In an immunohistochemical investigation 27 mammary carcinoma tissues were tested with a panel of monoclonal antibodies against cytokeratins, blood group-related and carcinoembryonic antigens. The monoclonal antibody A45-B/B3 directed against a broad range of cytokeratins reacted with all carcinoma tissues tested and was also useful for the detection of metastasis in axillary Lymph nodes of mammary carcinoma patients. The expression of blood group-related substances in tumor cells was different, but without relation to the donor's red blood cell phenotype. In our study the detection of CEA was restricted to malignant breast tumors and was present in two thirds of them.

Antibodies, Monoclonal↗
PubMed1988

[Treatment of long-term sterility by intra-tubal gamete transfer].

It is reported about a first successful program of gamete intra fallopian transfer (GIFT) as a supplement to intrauterine insemination and to in vitro fertilization (IVF). In 29 patients after HMG stimulation of the ovaries and laparoscopic aspiration of follicles recovered oocytes have been introduced together with prepared sperm via a special catheter directly into the ampulla of the oviduct. In 21 patients with different causes of infertility optimal stimulation conditions could be achieved. A pregnancy rate of 41.4% is the result of 29 GIFT events and 3 of them resulted in spontaneous term deliveries (10.3%).

Adult↗
PubMed1988

Immunoblotting of monoclonal anti-cytoskeletal antibodies with cytoskeletal extracts of HeLa and MCF-7 cells.

Cytoskeletal extracts of HeLa and MCF-7 cells were separated by SDS polyacrylamide gel electrophoresis, electrotransferred to nitrocellulose paper and exposed to five of our monoclonal antibodies (mabs) against structures of the cytoplasm as demonstrated in indirect immunofluorescence. Three of them reacted with cytokeratins according to histological evidence. All mabs tested in this study were reactive in immunoblotting. The broad-range anti-cytokeratin antibody A45-B/B3 was shown to react with cytokeratin polypeptides 8 and 18 and possibly 7, but not with cytokeratin 17.A53-B/A2 bound only to cytokeratin 19.Mab A 51-B/H4 showed a reaction with cytokeratin 18. Two mabs not yet described in detail (A45-C/H1 and A45-C/H9) reacted with a single band of 25 kD and may detect a cytoskeleton-associated protein.

Antibodies, Monoclonal↗
PubMed1987

[Torre-Muir syndrome. Sebaceous gland tumors indicate colon carcinoma and other internal malignant tumors].

The Torre-Muir syndrome belongs to a group of hereditory cancers and expresses itself in the occurrence of cutaneous gland tumors and (often multiple) carcinoma of the colon. The syndrome is probably a phenotypical manifestation of the "cancer family" syndrome, in which familial carcinoma of the colon also occurs. A case of Torre-Muir syndrome in a 43-year-old man is described. Because of the dermatological features, the colon carcinoma was diagnosed in time. Family investigations revealed another case of complete Torre-Muir syndrome, as well as a remarkable frequency of colon carcinoma in one family branch. Inheritance is autosomal dominant. The characteristic morphological features of the sebaceous gland neoplasias makes an early, often life-saving, diagnosis possible.

Adult↗
PubMed1987

Focal ependymal differentiation in the choroid plexus of human newborn brain confirmed by immunohistochemistry with monoclonal antibodies.

Ependymal proliferation ["Ependymzotten", G. Becker, Beitr Pathol Anat Allg Pathol 103:457-477 (1939)], found in choroid plexus of newborns, can be made easily visible by immunostaining with antiglial fibrillary acidic protein (GFAP) antibodies. The expression of both GFAP and cytokeratin is an unusual feature of these structures.

Cell Differentiation↗
PubMed1987

Histological evaluation of three new monoclonal anti-cytokeratin antibodies. 1. Normal tissues.

Three new monoclonal anti-cytokeratin antibodies (mabs) potentially useful in cancer research and clinical diagnosis have been evaluated in immuno-histochemistry on cryostat sections of a broad variety of normal human tissues. A45-B/B3 reacts with all cells containing cytokeratins (epithelia and mesothelia). This mab positively identifies epithelial cells of any kind, and it may serve in differentiating carcinomas from tumours of mesenchymal origin. A53-B/A2 recognizes an individual cytokeratin, No. 19, and stains preferably mesothelia, urothelium, and bile duct epithelium. This antibody is suited to discriminate between different epithelial lineages. A51-B/H4 reacts with a subgroup of cytokeratins (probably including Nos. 14, 8 and/or 18). It is positive with most epithelia but negative with keratanized stratified epithelium. This antibody shows an interesting, but up to now unexplained, cross-reactivity with nuclei of certain nonepithelial cells. All three mabs also react with epithelial cells from at least three animal species.

Animals↗
PubMed1987

Altered growth control by natural growth inhibitors in the mutant HD33 substrain of the Ehrlich-Lettré ascites mammary carcinoma.

The mutant substrain HD33 of the Ehrlich-Lettré ascites mammary carcinoma (EAC) was found to be altered in its ability to respond to and to produce natural growth inhibitors. Cells of this substrain did not respond to (1) a highly purified growth inhibitor from bovine mammary gland, inhibiting the proliferation of two strains of the original EAC already at concentrations of 0.5-2.0 ng/ml, (2) inhibitory activities found in the ascites fluid of these sensitive strains and partially purified. However, from the ascites fluid of the mutant substrain an inhibitory activity was partially purified, which was inhibitory towards this substrain. It also inhibited the cells from an original strain, although less effectively. This new inhibitory activity is similar in its properties to that of the others investigated in that its mol. wt is between 10,000 and 50,000 D, it is heat labile and its activity can be overcome by insulin, epidermal growth factor and 2'-deoxycytidine, the dose-response curve levels off at 35-45% inhibition. The results demonstrate that the regulation of cell proliferation by endogenous (autocrine) inhibitors can be altered by mutagen treatment.

Animals↗
PubMed1987

Characterization of established epithelioid cell lines derived from rat liver: expression of cytokeratin filaments.

A number of epithelioid cell lines were established from livers of fetal and neonatal rats. The clear-epithelial cells of these lines are non-neoplastically altered, clonogenic, nearly-diploid and showed no hepatocyte-like properties. The distribution and organization of intermediate filaments were analysed by indirect immunofluorescence and immunoperoxidase techniques using polyclonal and monoclonal antibodies against cytokeratins and vimentin. The different keratin antibodies also react strongly with intermediate filaments of bile duct cells on frozen sections of fetal and neonatal liver. Several subcultures of all established cell lines contained cell populations which reacted positively with antibodies against prekeratin and broad-range cytokeratins in a different manner, but not with antibodies against cytokeratin No. 19 of the catalogue of MOLL. The intermediate filaments are arranged in predominantly stained pericellular rings as well as in fine filamentous networks more evenly distributed throughout the cytoplasm. In early passages almost all cells were found positive for pre- and cytokeratins whereas in later subcultures the number of positive cells decreases and the expression of cytokeratin polypeptides varies considerably as seen with the different antibodies. All cells of the different cell lines show a well developed fine filamentous vimentin network extending throughout the whole cell up to the outer cell margin. Our findings support the concept that the clear epithelioid cells in established cell lines are of epithelial nature but they are not derived from biliary epithelium, and therefore probably immature parenchymal liver cells.

Animals↗
PubMed1987

Monoclonal anti-H antibody A46-B/B10 suited for differentiating blood groups A1 and A2 reveals also heterogeneity within blood group B.

A monoclonal antibody (mAb) recognizing H antigen was obtained from a BALB/c mouse immunized with MCF-7 (human mammary carcinoma) cells. This antibody (A46-B/B10, IgM) has been tested on a total of 753 blood samples. It strongly agglutinates human erythrocytes of blood groups 0, A2 and A2B, but not or only very weakly A1 and A1B. This mAb promises to be useful in the determination of A and AB subgroups in blood group serology. Evidence is presented that this antibody might also be able to define B subgroups. Among 263 B blood samples, 45 (17.1%) were negative or only weakly positive with A46-B/B10.

ABO Blood-Group System↗
PubMed1986

Coexistence of cytokeratin, vimentin and neurofilament protein in human choroid plexus. An immunohistochemical study of intermediate filaments in neuroepithelial tissues.

The expression of intermediate filament proteins in human brain ependyma and choroid plexus epithelium has been studied by immunohistochemistry using a panel of monoclonal antibodies directed against all five classes of intermediate filaments. Ependymal cells express GFAP and vimentin filaments, whereas plexus epithelium simultaneously contains neurofilaments, cytokeratins and vimentin, a phenomenon not previously observed in normal cells in vivo. By means of specific antibodies we were able to establish that cytokeratins 8 and 18 but not 19 are present in plexus epithelium.

Aged↗