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Biomedical subjects

H Vissing

Publications and source records attributed to H Vissing.

49 records · Page 3Linked to original sources
PubMed1989

Molecular pathobiology of human collagens.

The fibril-forming collagens (types I-III, V and XI) represent a homogeneous and evolutionary related group of proteins and genes. In addition to serving as supportive elements, these macromolecules influence the spatial and ontogenic diversity of extracellular matrices, for they regulate a number of developmental programs and cellular activities, such as adhesion, proliferation and migration. Deranged expression of fibrillar collagen genes results in a number of inherited and acquired disorders which greatly affect the structural integrity of the organism. An understanding of collagen biosynthesis and regulation in normal and diseased states provides an opportunity to dissect biological problems which relate to a wide variety of subjects, including morphogenesis, relationships between structure and function of proteins, gene expression and human mutations.

Animals↗
PubMed1988

Gene probes to detect cross-culture contamination in hormone producing cell lines.

Cross-culture contamination of cell lines propagated in continuous culture is a frequent event and particularly difficult to resolve in cells expressing similar phenotypes. We demonstrate that DNA-DNA hybridization to blotted endonuclease-digested cell DNA effectively detects cross-culture contamination to monitor inter-species as well as intra-species cross contamination. An insulin-producing cell-line, Clone-16, originally cloned from a human fetal endocrine pancreatic cell line did not produce human c-peptide as anticipated. DNA from these cells showed no hybridization to the human ALU sequence probe, BLUR, and lacked restriction fragment length polymorphism typical for the human HLA-DQ beta-chain gene. Although a human insulin gene probe showed a weak, nonhuman hybridization pattern, a cDNA probe for the Syrian hamster insulin gene hybridized strongly consistent with a single copy hamster insulin gene. Karyotyping confirmed the absence of human chromosomes in the Clone-16 cells while sizes, centromere indices, and banding patterns were identical to Syrian hamster fibroblasts. We conclude that the insulin-producing Clone-16 cells are of Syrian hamster origin and demonstrate the effective use of gene probes to control the origin of cell cultures.

Adenoma, Islet Cell↗
PubMed1987

Progress towards construction of a total restriction fragment map of a human chromosome.

We present an approach to the construction of an overlapping restriction fragment map of a single human chromosome. A genomic cosmid library genome was constructed from a mouse-human hybrid cell line containing chromosome 17 as its only human genetic component. Cosmids containing human inserts were isolated by hybridisation to a human Alu sequence. DNAs from ninety-six randomly chosen cosmids were digested with either EcoRI or HindIII, end-labelled with 35S-dATP and analysed using agarose gel electrophoresis. Comparison of the restriction fragment patterns revealed two pairs of overlapping clones, that were confirmed by cross-hybridization of the overlapping fragments. The two pairs of cosmids both mapped to human chromosome 17, as shown by hybridization to a panel of somatic cell hybrids. These data demonstrate that the generation of an overlapping cosmid map along a human chromosome is feasible, representing an intermediate step towards the complete sequencing of a human chromosome.

Animals↗
PubMed1986

A simple assay for the detection of antibodies to endocrine islet cell surface antigens.

A simple and sensitive immunoradiometric assay for the detection of islet cell surface antibodies (CIRMA) has been developed. Live, transformed islet cells derived from a liver metastasis of a transplantable islet cell tumor were grown in removable microtiter wells and incubated with antibody. Cell-bound antibodies were quantitated using 125I-labelled second antibodies. The assay was used to detect islet cell antibodies present in sera from non-diabetic and diabetic BB rats and proved to be particularly effective for screening hybridoma supernatants in order to identify monoclonal antibodies recognizing islet cell surface antigens.

Animals↗
PubMed1986

Monoclonal antibodies against pancreatic islet-cell-surface antigens selected by flow cytofluorometry.

BALB/c mice were immunized with human islets of Langerhans, and spleen cells from two mice, found to develop cell-surface antibodies against insulin-producing rat islet tumour RIN-5F cells, were fused with mouse myeloma cells. Antibody-producing hybrids were cloned on the basis of their production of surface antibodies reactive with paraformaldehyde-fixed RIN-5F cells by indirect immunofluorescence analysis in the fluorescence-activated cell sorter. Among 236 primary clones, eight stable cell lines producing islet-cell-surface antibodies were eventually cloned. Antibody 2G3 (IgM) reacted with viable normal rat islet cells and high insulin-producing rat islet tumour RIN5-A2 cells, while 3G3 (IgM) only reacted with RIN5-A2 cells. Antibody beta B1 (IgG1) reacted with all islet cells tested and detected an Mr21k component in immunoblotting experiments with RIN-5AH cell plasma membrane proteins electrophoretically transferred to nitrocellulose filters. Antibody 7F6 (IgM) reacted with all islet and non-islet cells tested and detected bands of Mr 66k and 27k by immunoblotting. Antibodies gamma B3, gamma B6, gamma C2, and 6B1 (all IgM) showed varying degrees of binding to different islet cells, but reacted only weakly with non-islet human cells. It is concluded that monoclonal antibodies against pancreatic islet cells may define specific endocrine islet-cell-surface determinants.

Animals↗
PubMed1985

Flow cytometric analysis of monoclonal islet cell surface antibodies reacting with RINm5AH insulinoma cells.

Two monoclonal islet cell surface antibodies, isolated following immunization with human pancreatic islets, were analyzed for reactivity with the insulin-producing rat islet tumor RINm5AH cell line using computer assisted flow cytometric analysis. The antibody binding was quantified utilizing the gating facilities, single and dual parameter analysis of this system which are not available in conventional assays for cell surface antibody determination. The two antibodies specifically bind to the RINm5AH cells, although the dual parameter analysis demonstrated binding to only a subpopulation.

Animals↗