Alveolar macrophages produce neutrophil chemoattractants; this cellular cross-talk contributes to neutrophilic airway inflammation in chronic obstructive pulmonary disease (COPD). We have investigated the chemotaxis cross-talk mechanisms between these cells using COPD alveolar macrophages. Using conditioned media from stimulated COPD alveolar macrophages, we investigated the relative contributi...

We examine a general model for the Fisher-KPP (FKPP) equation with nonlocal advection. The main interpretation of this is as describing diffusing and logistically growing population that also influenced by intraspecific attraction or repulsion. For particular choice parameters, specializes to Keller-Segel-Fisher chemotaxis. Our interest in effect chemotaxis on speed traveling waves. prove there...

Keller-Segel equations are widely employed to explain chemotaxis-induced bacterial traveling band phenomena. In this system, the dispersal of bacteria is modeled by independently given diffusion and advection terms, growth cell population neglected. paper, we develop a chemotaxis model which consists cross-diffusion growth. particular, consider case that terms form an exact cross-diffusion. The...

Escherichia coli and Salmonella typhimurium show positive chemotaxis to glycerol, a chemical previously reported to be a repellent for E. coli. The threshold of the attractant response in both species was 10(-6) M glycerol. Glycerol chemotaxis was energy dependent and coincident with an increase in membrane potential. Metabolism of glycerol was required for chemotaxis, and when lactate was pres...

Polymorphonuclear leukocyte (PMNL) chemotaxis studies of 32 patients with localized juvenile periodontitis (periodontosis or LJP), 10 adult patients with a history of LJP (post-LJP), 8 patients with generalized juvenile periodontitis (GJP), and 23 adults with moderate to severe periodontitis were performed: (i) to determine the prevalence of a PMNL chemotaxis defect in a large group of LJP pati...

UNLABELLED Pseudomonas aeruginosais an opportunistic human pathogen that has long been known to chemotax. More recently, it has been established that chemotaxis is an important factor in the ability ofP. aeruginosato make biofilms. Genes that allowP. aeruginosato chemotax are homologous with genes in the paradigmatic model organism for chemotaxis,Escherichia coli However,P. aeruginosais singly ...

Chemotaxis toward different cyclic adenosine monophosphate (cAMP) concentrations was tested in Dictyostelium discoideum cell lines with deletion of specific genes together with drugs to inhibit one or all combinations of the second-messenger systems PI3-kinase, phospholipase C (PLC), phospholipase A2 (PLA2), and cytosolic Ca(2+). The results show that inhibition of either PI3-kinase or PLA2 inh...

Various Ca antagonists used in animal research, many of them known to be Ca 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 v-conotoxin GVIA. The next most effective were gallopamil and verapamil. At concentrations around 100-fold higher than that needed f...

Many processes in biology involve both reactions and chemotaxis. However, to the best of our knowledge, the question of interaction between chemotaxis and reactions has not yet been addressed either analytically or numerically. We consider a model with a single density function involving diffusion, advection, chemotaxis, and absorbing reaction. The model is motivated, in particular, by studies ...