Gearold R. Johnson

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A new, numerically minute population of cells representing the earliest T precursor cells in the adult mouse thymus has recently been isolated. This population has been shown to be similar to bone marrow hemopoietic stem cells in surface antigenic phenotype and to express moderate levels of CD4. We now show, by fluorescence-activated cell sorting and(More)
Illustrations of macromolecular structure in the scientific literature contain a high level of semantic content through which the authors convey, among other features, the biological function of that macromolecule. We refer to these illustrations as molecular scenes. Such scenes, if available electronically, are not readily accessible for further(More)
Genetic algorithms are a robust adaptive optimization technique based on a biological paradigm. They perform efficient search on poorly-defined spaces by maintaining an ordered pool of strings that represent regions in the search space. New strings are produced from existing strings using the genetic-based operators of recombination and mutation. Combining(More)
Amphiregulin (AR) is a newly discovered glycosylated, 84-amino acid residue polypeptide growth regulator which has sequence homology to the EGF family of proteins. To obtain immunological reagents to study the biological role of AR, two synthetic peptides containing sequences corresponding to distinct regions of AR were used to generate polyclonal(More)
Murine bone marrow Lin-, Ly6A/E + cells have been fractionated on the basis of rhodamine123 retention into Rh123 m~d/hi and Rh123 l~ subpopulations. These populations have different responses to hemopoietic growth factors with respect to in vitro colony formation. Cells from either fraction were not stimulated by only granulocyte-colony-stimulating factor(More)
A new mechanism is being developed for expanding international exposure for undergraduate engineering and computer science students in the United States, using information technology and distance learning techniques. Technical students in the United States, in a few instances, have begun working on projects with similar students in other countries via(More)
A colony-stimulating factor (M-CSF) has been partially purified and concentrated from mouse yolk sac-conditioned medium (YSCM). M-CSF appeared to preferentially stimulate CBA bone marrow granulocyte-macrophage progenitor cells (GM-CFC) to differentiate to form macrophage colonies in semisolid agar cultures. By comparison, colony-stimulating factor (GM-CSF)(More)
The potential of transforming growth factor-alpha (TGF-alpha) to function as an autocrine growth factor was evaluated in numerous ovarian carcinoma cell lines. All 17 lines which were examined expressed the epidermal growth factor receptor and 16 cell lines, in addition, concomitantly secreted TGF-alpha. Radioimmunoassay of processed serum-free-conditioned(More)