PubMed Health⌕ Search

Biomedical subjects

E M Earley

Publications and source records attributed to E M Earley.

13 recordsLinked to original sources
PubMed1995

Factors influencing mossy fiber collateral sprouting in organotypic slice cultures of neonatal mouse hippocampus.

Collateral sprouting of dentate granule cell axons, the mossy fibers, occurs in response to denervation, kindling, or excitotoxic damage to the hippocampus. Organotypic slice culture of rodent hippocampal tissue is a model system for the controlled study of collateral sprouting in vitro. Organotypic roller-tube cultures were prepared from hippocampal slices derived from postnatal day 7 mice. The Timm heavy metal stain and densitometry were used to assay the degree of mossy fiber collateral sprouting in the molecular layer of the hippocampal dentate gyrus. Factors influencing mossy fiber collateral sprouting were time in culture, positional origin of the slice culture along the septotemporal axis of the hippocampus, and presence of attached subicular-entorhinal cortical tissues. Collateral sprouting in the molecular layer was first detected after 6 days in culture and increased steadily thereafter. By 2 weeks considerable sprouting was apparent, and at 3 weeks intense sprouting was observed within the molecular layer. An intrinsic septal-to-temporal gradient of collateral sprouting was apparent at 14 days in culture. To determine whether differential damage to the mossy fibers was the basis for the differences in collateral sprouting along the septotemporal axis, we made complete transections of the mossy fiber projection as it exited the dentate hilus at various levels along the septotemporal axis; no differences were found on subsequent collateral sprouting in the dentate molecular layer. Timm-stained hippocampal cultures with an attached entorhinal cortex, a major source of afferent innervation to the dentate granule cells, displayed significantly less collateral sprouting at 10 days in culture compared to that in cultures from adjacent sections without attached subicular-entorhinal tissues present. Thus, time in culture, position along the septotemporal axis, and presence of afferent cortical tissues influence aberrant neurite collateral sprouting in organotypic slice cultures of neonatal mouse hippocampus.

Animals↗
PubMed1995

Human monoclonal antibody BT32/A6 and a cell cycle-independent glioma-associated surface antigen.

The purpose of this study was to ascertain how various growth parameters may influence the labeling of SK-MG-1, a human glioma cell line, by BT32/A6, a human immunoglobulin M monoclonal antibody (MAb). By growing SK-MG-1 cells at different culture split ratios, significant trends in cell growth rate, culture viability, and cell cycle state were produced. Labeling of SK-MG-1 cells by BT32/A6, however, was shown to be unaffected by culture split ratio (p > 0.05) and is therefore independent of cell growth rate, culture viability, and cell cycle state. Using flow cytometry and fluorescence-activated cell sorting, BT32/A6 was shown to label a cell surface antigen on viable, clonogenic cells of SK-MG-1. Approximately 100% of SK-MG-1 cells were shown by flow cytometry to express the BT32/A6 antigen. The recognition of a glioma-associated, cell cycle-independent surface antigen by MAb BT32/A6 makes it a promising candidate for further studies aimed at elucidating its usefulness as an adjunct in the treatment of human malignant gliomas.

Antibodies, Monoclonal↗
PubMed1979

Characterization of the WIDR: a human colon carcinoma cell line.

We describe the establishment and characterization of WiDr, a cell line derived from a human colon carcinoma. It produces carcinoembryonic antigen in culture, and has a doubling time of 15 hr with plating efficiency of 51%. The HLA antigenic profile and the allozyme genetic signature (composed of eight gene-enzyme systems) of WiDr cells are different from those of HeLa cells. Furthermore, WiDr cells possess three marker chromosomes, again distinct from the HeLa marker chromosomes. Finally, it is highly tumorigenic in four different xenogeneic animal models. Based on these studies, WiDr represents a useful model cell line for tumor cell biology investigations.

Carcinoembryonic Antigen↗
PubMed1976

Karyology of primary human fetal cell cultures.

Cell cultures were established from the biopsies of lung, skin and kidney from each of nine human fetuses, and chromosome analyses were performed on material through the fifth subculture. Kidney cell cultures generally showed a higher level of polyploidy than lung or skin. The frequencies of hyperdiploid cells and those with structural abnormalities were consistent with the low levels found in cultures of human lymphocytes. The data provide a normal cytogenetic baseline for human fetal material which may be useful in a variety of studies.

Cells, Cultured↗
PubMedDate not supplied

Growth characteristics, cytogenetic stability and virus susceptibility of cell lines from New Zealand rabbits.

We have initiated and established over 90 cell cultures from tissues of embroynic New Zealand rabbits. These cell lines show a very varied growth pattern when compared to cell lines initiated from human embryonic tissues. The type of medium used to grow the cells influences the chromosome stability of rabbit cells. Cultures initiated from kidney tissue rarely grow more than 10 passages unless the medium is supplemented with lactalbumin hydrolysate. In turn, analyses of metaphase chromosomes from the kidney cultures, revealed they were aneuploid as early as passages 15. Cultures established from skin and lung tissues will remain diploid at least 60 passages when grown on Eagle's Basal Medium supplemented with 10% fetal bovine serum. However, rarely do rabbit cell lines go into senescence.

Aneuploidy↗
PubMedDate not supplied

Karyotype analysis of cell sex to determine the source of vascular graft luminal linings following autologous and nonautologous endothelial cell seeding.

Endothelial cell-seeded bilateral carotid ePTFE grafts were studied in 11 dogs to determine the source of their eventual luminal linings. One graft was prepared with autologous cells and the other with nonautologous cells. Immunosuppression was accomplished with cyclosporin and prednisolone. At 2 and 3 weeks post implantation, grafts were removed, revealing 9 of 11 autologous and 8 of 11 nonautologous seeded conduits to be patent. Linings were harvested enzymatically and grown in tissue culture, with karyotype analysis limited to cultures that exhibited greater than or equal to 50% endothelium (n5 autologous, n7 nonautologous). Sex type was classified in 20 cells from each graft. All five autologous cell-seeded grafts revealed host cells. Among the seven nonautologous cell-seeded grafts, one harbored only non-autologous cells, three revealed only autologous cells, and three exhibited a predominance of autologous cells with lesser numbers of nonautologous endothelium. All 100 cells from the autologous-seeded grafts were the same sex as seeded cells, while only 28 of the 140 cells from the nonautologous seeded grafts were the same sex as seeded cells (P less than 0.001). Thus, nonautologous endothelial cell seeding with immunosuppression did not uniformly produce nonautologous cell linings, but was more often associated with autologous endothelial cell linings that may have been promoted by the nonautologous cell seeding.

Animals↗
PubMedDate not supplied

Interpretative differences in cytogenetic analyses: preliminary results of a collaborative study.

In an effort to establish some of the parameters which influence differences in interpretation of chromosome aberrations, we initiated a collaborative study with 26 different laboratories located in the U.S., Canada and Europe. They include government, private industry, and academic institutions. Three species were selected for study which vary in chromosome number and complexity of the karyotype. These were the Chinese hamster, human, and African green monkey. Each metaphase was preselected and numbered. This allowed each participant in the study to screen exactly the same cells. Most of the participating laboratories have reported the results of their analyses of the Chinese hamster series, and that data is now being analyzed. A detailed discussion of the study format and the preliminary results on the Chinese hamster cells will be presented.

Animals↗