Ralph M. Johnson

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The HER2 protooncogene encodes a growth factor receptor-like transmembrane protein tyrosine kinase (p185HER2) whose ligand remains to be fully characterized. The overexpression of p185HER2 is implicated in aggressive forms of breast and ovarian cancers. The role of p185HER2 in aggressive malignancy, as well as its cell surface localization, makes it an(More)
The endogenous cannabimimetic anandamide is hydrolyzed by a fatty acid amide hydrolase to yield arachidonic acid and ethanolamine. In the present study, the regional distribution of the activity and its sensitivity to inhibition by the enantiomers of ibuprofen, ketorolac, and flurbiprofen has been investigated. The rate of [3H]anandamide hydrolysis was(More)
Muscle regeneration involves the coordination of myogenesis and revascularization to restore proper muscle function. Myogenesis is driven by resident stem cells termed satellite cells (SC), whereas angiogenesis arises from endothelial cells and perivascular cells of preexisting vascular segments and the collateral vasculature. Communication between myogenic(More)
The fatty acid composition of liver mitochondrial phospholipids from rats rendered deficient in essential unsaturated fatty acids has been determined, and compared with that of rats fed a diet containing corn oil. In addition to marked reductions in the amounts of linoleic and arachidonic acids esterified a t the &position of ethanolamine-, inositol-, and(More)
A partially agonistic monoclonal antibody, 4D5, known to bind to the extracellular domain of p185HER2 and shown to inhibit long term growth of p185HER2-overexpressing breast cancer cells, was used to study signal transduction and phosphotyrosyl protein substrates associated with this receptor. Normal breast epithelial cells and breast carcinoma cells(More)
Micromolar deoxyadenosine inhibits leucine uptake during the 1st day of proliferation in mitogen-stimulated lymphocytes if adenosine deaminase is inhibited. This inhibition occurs before DNA synthesis begins, suggesting that deoxyadenosine can affect mitogenesis by mechanisms that do not involve ribonucleotide reductase inhibition. If deoxyadenosine(More)
The mechanisms by which PTH and thrombin mobilize intracellular Ca2+ (Cai2+) were examined in UMR 106-H5 rat osteosarcoma cells. Bovine PTH-(1-34) (24 pM to 240 nM) produced a dose-dependent increase in Cai2+ (EC50, 3 nM), which returned to baseline within 75 sec. Human alpha-thrombin produced an increase in Cai2+ (ECmax, 10 U/ml) which was similar to that(More)
Two lymphoblast lines from a patient with partial adenosine deaminase deficiency have been obtained. The patient has a T cell deficiency, with normal B cell function, and has been successfully treated by multiple partial exchange transfusions with normal erythrocytes. The patient's lymphocytes have about 8% of normal adenosine deaminase activity. The(More)