The characteristics of cell adsorption and pinocytotic uptake of diphtheria toxin by several mammalian cell types were studied. Purified toxin iodinated by a solid-state lactoperoxidase method provided preparations of high specific activity and unaltered biological activity. Dephtheria toxin-sensitive HEp-2 cells and guinea pig macrophage cultures were compared with resistant mouse L-929 cells....

Mycoplasma pneumoniae is an atypical bacterium that causes respiratory illnesses in humans, including pharyngitis, tracheobronchitis, and community-acquired pneumonia (CAP). It has also been directly linked to reactive airway disease, asthma, and extrapulmonary pathologies. During its colonization, M. pneumoniae expresses a unique ADP-ribosylating and vacuolating cytotoxin designated community-...

The binding and uptake of fluorescently labeled diphtheria toxin by cells in culture has been examined by using epifluorescence video intensification microscopy. Rhodamine-labeled diphtheria toxin retained significant toxicity on bioassay and in cell culture and was tested for uptake by human WI-38 and mouse 3T3 fibroblasts grown in culture. When added to cells at 37 degrees C, toxin was observ...

Infection with Shiga toxin- and Shiga-like toxin-producing strains of Shigella dysenteriae and Escherichia coli, respectively, can progress to the hemolytic-uremic syndrome. It has been hypothesized that circulating Shiga toxin, Shiga-like toxins, and endotoxins may contribute to the disease by directly damaging glomerular endothelial cells. The effects of these toxins on HeLa, Vero, and human ...

A direct solid-phase radioimmunoassay procedure was developed for the determination of cholera toxin and cholera toxin antibody. The reported method employed anti-choleragenoid antibody attached to polystyrene tubes as a solidified binder for cholera toxin. The binding of radioidinated cholera toxin on its solidified antibody was inhibitable by unlabeled cholera toxin and cholera toxin antibody...

Bacillus thuringiensis (Bt) Cry toxins are used to control Aedes aegypti, an important vector of dengue fever and yellow fever. Bt Cry toxin forms pores in the gut cells, provoking larvae death by osmotic shock. Little is known, however, about the endocytic and/or degradative cell processes that may counteract the toxin action at low doses. The purpose of this work is to describe the mechanisms...

in this research a molecular method based on polymerase chain reaction for typing of clostridium perfringens was developed and toxin genotypes of 64 isolates from sheep and goats in iran were determined. the pcr assays were developed for detection of alpha (cpa), beta (cpb) and epsilon (etx) toxin genes, allowing classification of the isolates into genotypes a b, c and d. the field isolates ...

objectives: enterotoxigenic escherichia coli (etec) is one of the most common agents of diarrhea among other bacterial agents. designing and producing vaccine against these bacteria is one of the major purposes of world health organization (who). due to presence of diverse clones of etec strains in the world, the use of global vaccines for etec infection is controversial. b subunit of heat labi...

Snakes are equipped with their venomic armory to tackle different prey and predators in adverse natural world. The venomic composition of snakes is a mix of biologically active proteins and polypeptides. Among different components snake venom cytotoxins and short neurotoxin are non-enzymatic polypeptide candidates with in the venom. These two components structurally resembled to three-finger pr...

The biochemical characteristics of specific receptor molecules for diphtheria toxin on the surface of two toxin-sensitive cell lines (Vero and BS-C-1) were examined. Diphtheria toxin was found to bind to a number of different proteins in Nonidet P-40 solubilized extracts of 125I-labeled cells. In contrast, permitting diphtheria toxin to bind first to labeled intact cells, which were subsequentl...