Various Ca(2+) antagonists used in animal research, many of them known to be Ca(2+) channel blockers, inhibited Escherichia coli chemotaxis (measured as entry of cells into a capillary containing attractant). The most effective of these, acting in the nanomolar range, was omega-conotoxin GVIA. The next most effective were gallopamil and verapamil. At concentrations around 100-fold higher than t...

Improvements in neutrophil chemotaxis assays have advanced our understanding of the mechanisms of neutrophil recruitment; however, traditional methods limit biologic inquiry in important areas. We report a microfluidic technology that enables neutrophil purification and chemotaxis on-chip within minutes, using nanoliters of whole blood, and only requires a micropipette to operate. The low sampl...

This paper is concerned with a spatially two-dimensional version of chemotaxis system logistic cell proliferation and death, for singular tactic response standard logarithmic type, interaction surrounding incompressible fluid through transport buoyancy. Systems this form are significant relevance to the understanding chemotaxis-fluid interaction, but rigorous knowledge their qualitative propert...

The molecular machinery that controls chemotaxis in bacteria is substantially more complex than any other signal transduction system in prokaryotes, and its origins and variability among living species are unknown. We found that this multiprotein "chemotaxis system" is present in most prokaryotic species and evolved from simpler two-component regulatory systems that control prokaryotic transcri...

Atheroma formation involves the movement of vascular smooth muscle cells (VSMC) into the subendothelial space. The aim of this study was to determine the involvement of PI3K and MAPK pathways and the importance of cross-talk between these pathways, in glucose-potentiated VSMC chemotaxis to serum factors. VSMC chemotaxis occurred in a serum gradient in 25 mmol/L glucose (but not in 5 mmol/L gluc...

We examined chemotaxis of human plasma cells (PCs) in response to extracellular matrix proteins (ECMs) in the human PC cell lines FR4ds and OPM-1ds. The FR4ds cells expressed beta 1+, beta 3-, alpha 2-, alpha 3-, alpha 4+, alpha 5+, alpha 6+, and alpha v+ integrins, whereas the OPM-1ds cells expressed beta 1+, beta 3-, alpha 2-, alpha 3+, alpha 4+, alpha 5-, alpha 6+, and alpha v+. Fibronectin ...

We have previously (1-4) demonstrated that adenosine, by engaging specific receptors on the surface of neutrophils, inhibits generation of toxic oxygen metabolites by activated neutrophils and prevents these activated neutrophils from injuring endothelial cells. We now report the surprising observation that engagement of these same neutrophil adenosine receptors promotes chemotaxis to C5 fragme...

Escherichia coli and Salmonella typhimurium are closely related species. However, E. coli cells show maltose chemotaxis but S. typhimurium cells do not. When an E. coli chemotransducer gene (tarE), the product of which is required for both aspartate and maltose chemotaxis, was introduced by using a plasmid vector into S. typhimurium cells with a defect in the corresponding gene (tarS), the tran...

Five strains each of Neisseria gonorrhoeae sensitive or resistant to complement (C) dependent killing by normal human serum (NHS) were examined for their ability to stimulate chemotaxis of polymorphonuclear leukocytes (PMNs) after preincubation with NHS; or IgM or IgG derived from NHS. Serum-sensitive N. gonorrhoeae stimulated C-dependent chemotaxis when opsonized with IgM, but not IgG, however...

Escherichia coli exhibits chemotactic responses to sugars, amino acids, and dipeptides, and the responses are mediated by methyl-accepting chemotaxis proteins (MCPs). Using capillary assays, we demonstrated that Escherichia coli RP437 is attracted to the pyrimidines thymine and uracil and the response was constitutively expressed under all tested growth conditions. All MCP mutants lacking the M...