ABSTRACT
Cross-linkage of the high-affinity receptor for IgE (Fc epsilon RI) by a polyvalent ligand, leads to activation of mast cells and basophils. We have studied Fc epsilon RI-mediated expression of RNA coding for the protooncogene, c-fos, in rat basophilic leukemia (RBL) cells and specifically have examined the requirements for ongoing receptor aggregation in the generation of this signal. RBL cells were sensitized with IgE specific for 2,4-dinitrophenyl (DNP) and incubated at 37 degrees C in the presence of DNP24BSA or BSA alone. Following activation for 0 to 30 min, the reaction was terminated. RNA was isolated and separated on denaturing gels, blotted to nylon membranes and hybridized with a 32P-labelled cDNA probe for c-fos. Messenger RNA for c-fos is detectable as early as 5-10 min following the addition of antigen and increases in a time-dependent fashion over 30 min. Unexpectedly, the addition of the hapten, 10(-4) M DNP-lysine, 5 min after the addition of antigen (which causes immediate cessation of exocytosis) does not dramatically alter the amount of message detected at 30 min. This effect is present as early as 2 min after cross-linking of the receptor and occurs at various doses of the aggregating stimulus. Thus, in contrast to the case with exocytosis and other well-described intracellular events, Fc epsilon RI-mediated increases in the level of mRNA for c-fos does not require ongoing aggregation of Fc epsilon RI.
Subject(s)
Genes, fos , Leukemia, Basophilic, Acute/genetics , Leukemia, Basophilic, Acute/metabolism , RNA, Messenger/metabolism , Receptors, IgE/metabolism , Animals , Dinitrobenzenes/immunology , Exocytosis , Haptens , Leukemia, Basophilic, Acute/immunology , Protein Kinase C/metabolism , Protein-Tyrosine Kinases/metabolism , RNA, Messenger/genetics , Rats , Receptor Aggregation , Signal Transduction , Tumor Cells, Cultured/immunology , Tumor Cells, Cultured/metabolism , Type C Phospholipases/metabolismSubject(s)
Eye Infections, Bacterial/pathology , Leprosy, Lepromatous/pathology , Uveitis, Anterior/pathology , Adult , Biopsy , Humans , MaleABSTRACT
A 61-year-old man presented with a mass in the right upper quadrant of the abdomen. Computer tomography scanning (CT) had initially suggested that the location was in the head of the pancreas. Further examination with ultrasonography and celiac angiography documented that the mass was an aneurysm of the common hepatic artery. The successful approach to its surgical management is described.
Subject(s)
Aneurysm/diagnostic imaging , Hepatic Artery , Aneurysm/epidemiology , Aneurysm/surgery , Angiography , Blood Vessel Prosthesis , Diagnosis, Differential , Humans , Male , Middle AgedABSTRACT
We report a method for the isolation of total cellular RNA from mineralized or cartilaginous tissues. The procedure accommodates the large amount of hydroxyapatite and high buoyant density proteoglycans present in skeletal tissue samples, as well as the low cell density characteristic of these tissues. The procedure can be reliably used for processing a large number of small (100-800 mg) tissue samples. Tissues are homogenized in guanidine hydrochloride solution, then centrifuged at low speed, and filtered to remove the nonsolubilized extracellular matrix proteins. Subsequent high speed density gradient centrifugation produces a high yield of RNA (0.2-0.6 micrograms RNA/mg tissue) which is precipitated in a low pH sodium acetate solution. RNA extracted by this method has been analyzed for the expression of various genes by Northern blotting. In addition to mRNAs of bone- and cartilage-specific proteins, messenger RNA for growth factors, proto-oncogenes, and heat shock proteins can be detected.