'A series of compounds including 4-amino (1), 3-amino (2), 4-nitro (3), 2-methyl-3-amino (4), 2-methyl-3-nitro (5), 2-methyl-4-amino (6), 2-methyl-4-nitro (7), 2-methyl-5-amino (8), 2-methyl-5-nitro (9), 2-methyl-6-amino (10), 2-methyl-6-nitro (11), 2,6-dimethyl (12), 2-methyl-3-carboxy (13), 2-methoxycarbonyl (14), 2-methyl-4-methoxy (15), 2,4-dimethoxy (16), 2-chloro-4-amino (17), and 2-chloro-4-nitro (18) N-phenyl substituents of phthalimide were evaluated along with ... More
Optimization of the transfection of human endothelial cells by electroporation.
AuthorsSchwachtgen JL, Ferreira V, Meyer D, Kerbiriou-Nabias D
JournalBiotechniques
PubMed ID7840968
A method for efficient transfection of human umbilical vein endothelial cells (HUVEC) is presented here. The procedure involves cell synchronization followed by electroporation and allows the detection of the activity of low-strength promoters. Sodium butyrate, added to the culture medium after electroporation, strongly potentiates the transcriptional activity of viral promoters. ... More
Expression of mRNA electroporated into plant and animal cells.
Authors Callis J; Fromm M; Walbot V;
JournalNucleic Acids Res
PubMed ID3475678
A general method to introduce RNA molecules into plant protoplasts and animal cells is described. This technique utilizes the ability of electric pulses of high field strength to form pores in biomembranes. RNA molecules containing the coding region for the bacterial enzyme chloramphenicol acetyltransferase (CAT) were used as a model ... More
Initiation of the phosphocholine-specific response to Proteus morganii. B cell transfectants expressing unmutated VH/VL can respond to stimulation by P. morganii antigen.
AuthorsPenner SJ, George J, Claflin L
JournalJ Immunol
PubMed ID7544373
We wished to resolve a paradox of how the response to the phosphocholine (PC) determinant of Proteus morganii could be initiated from a precursor B cell whose receptor, in unmutated form as Ab, appears to be unable to bind Ag. Unmutated VH and unmutated VL constructs were co-transfected into the ... More
Efficient gene targeting in mouse embryonic stem cells.
Authors Templeton N S; Roberts D D; Safer B;
JournalGene Ther
PubMed ID9282171
We developed methods to improve the efficiency of gene correction in mouse embryonic stem cells using homologous recombination of a replacement vector. The absolute frequency of homologous recombination in mouse embryonic stem (ES) cells, defined as the frequency of homologous recombination per electroporated cell, is approximately 10(-5) to 10(-6) by ... More
A role for the insulin-interleukin (IL)-4 receptor motif of the IL-4 receptor alpha-chain in regulating activation of the insulin receptor substrate 2 and signal transducer and activator of transcription 6 pathways. Analysis by mutagenesis.
Authors Wang H Y; Zamorano J; Keegan A D;
JournalJ Biol Chem
PubMed ID9545332
The interleukin (IL)-4 receptor alpha-chain (IL-4Ralpha) contains a sequence motif (488PLVIAGNPAYRSFSD) termed the insulin IL-4 receptor motif (I4R motif). Mutation of the central Tyr497 to Phe blocks the tyrosine phosphorylation of the insulin receptor substrate 1 (IRS1) and diminishes proliferation in response to IL-4. Recent data suggest that the I4R ... More
Influence of membrane Ig receptor density and affinity on B cell signaling by antigen. Implications for affinity maturation.
Authors George J; Penner S J; Weber J; Berry J; Claflin J L;
JournalJ Immunol
PubMed ID8245440
We have initiated a series of experiments to explore the effect of changes in density of the surface Ig receptor (mIg) on Ag:mIg interactions. We transfected into the surface Ig-negative B cell line M12.4 H and L chain constructs known to effect a 10-fold change in antibody binding affinity for ... More