Haemophilus ducreyi produces a cytotoxin responsible for the killing of cultured human epithelial cells. Cytotoxin-neutralizing antibodies were detected in the majority of sera from patients with culture-proven chancroid, and a significantly higher level of such antibodies in patients than in blood donors was noted both in areas where the disease is endemic and those where it is not. We produce...

An animal lectin purified from loach (Misgurnus anguillicaudatus) eggs induced release of cytotoxin from fresh bone marrow cells from mice, although the other lectins tested, wheat germ agglutinin, concanavalin A, and phytohemagglutinin did not. The cytotoxin released from bone marrow cells was a heat-labile protein with a molecular weight of 70,000. The main cells responsible for release of Mr...

Cytotoxin release by bone marrow-adherent cells and peritoneal macrophages was transiently augmented by i.p. inoculation of syngeneic tumor cells, but not normal cells. These effects were maximal 24-48 h after tumor transplantation. The cytotoxin released from bone marrow-adherent cells obtained 24 h after tumor inoculation had a molecular weight of about 70,000. Peritoneal macrophages obtained...

Infectious bovine keratoconjunctivitis (IBK) caused by Moraxella bovis is the most common eye disease of cattle. The pathogenesis of M. bovis requires the expression of pili that enable the organism to attach to the ocular surface and an RTX (repeats in the structural toxin) toxin (cytotoxin or hemolysin), which is cytotoxic to corneal epithelial cells. In this pilot study, ocular mucosal immun...

Macrophages in the presence of bacteria-derived lipopolysaccharide (LPS) stimuli produce a soluble cytotoxin which is toxic to tumor cells. In this study, we examined various parameters of cytotoxin production from pulmonary lavage cells obtained from Fisher 344 cesarean-derived rats. Cultures of macrophages were derived from pulmonary lavage cells and stimulated in vitro with LPS. Cytotoxin pr...

BACKGROUND IL-13 receptor (IL-13R) targeted cytotoxin, IL13-PE38QQR, has been shown to have very potent anti-tumor activity to IL-13R-expressing head and neck tumor cells in vitro and in vivo. However, its effect is limited in aggressive tumors. To further improve the anti-tumor activity and safety of IL-13 cytotoxin, we employed continuous infusion technique in animal model of head and neck ca...

BACKGROUND Helicobacter pylori is a Gram negative bacterium that plays a central role in the etiology of chronic gastritis and peptic ulcer diseases. However, not all H. pylori positive cases develop advanced disease. This discriminatory behavior has been attributed to the difference in virulence of the bacteria. Among all virulence factors, cytotoxin released by H. pylori is the most important...

A quantitative assay for Clostridium difficile cytotoxin has been developed, based on the observation that suspended fibroblasts exposed to cytotoxin fail to adhere to plastic. A dye-binding technique was used to quantitate adherent cells, in order to obviate microscopy. Adherent BHK cells were fixed with glutaraldehyde and cell protein was stained with Coomassie blue R-250. Cell-bound dye was ...

AIM To identify and characterize the subunit structure of interleukin-13 receptor (IL-13R) in human medulloblastoma cell lines and target them with a chimeric fusion protein consisting of interleukin-13 and Pseudomonas exotoxin (termed as IL-13 cytotoxin). METHODS Five human medulloblastoma cell lines were examined for the expression of IL-13R subunits at the mRNA and protein levels by revers...

PURPOSE Hypoxia is a cause for resistance to cancer therapies. Molecularly targeted recombinant cytotoxins have shown clinical efficacy in the treatment of patients with primary brain tumors, glioblastoma multiforme, but it is not known whether hypoxia influences their antitumor effect. EXPERIMENTAL DESIGN We have exposed glioblastoma multiforme cells, such as U-251 MG, U-373 MG, SNB-19, and ...