teins on the tumor cells was shown to be specific, pH de pendent, and concentration dependent. Native ricin, abrin, D-galactose, and its sterically related saccharides inhibit this specific binding, while concanavalin A, bovine serum albumin, heat-denatured abrin or ricin, and other sac charides do not. In the presence of D-galactose, the inhibi tion of protein biosynthesis by ricin does not oc...

The effect of different anions on the sensitivity of Vero cells to ricin was investigated. The cells were equally sensitive to ricin when NaCl was replaced by NaBr, NaI, Na2SO4 or with iso-osmotic concentrations of mannitol. In contrast, NaSCN and NaClO4 strongly protected against ricin at pH 7.2, but not at pH 7.6. The possibility that the protective effect is due to the ability of chaotropic ...

Diisopropylfiuorophosphate {OFP), a general serine protease inhibitor, inhibited the DNA fragme"tatioll and cell death in MDCK cells treated with ricin, modeccin, Ilseudomonas toxin, or dipbtberia toxin. Atrypsin-like serine protease inhibitor, IVLtosyl・L-lysine chleromethyl ketone (TLCK) also prevented ricin-induced DNA fragmentation and cel] death, albeit less effectiyely than DFP. Microscopi...

PURPOSE The authors recently demonstrated that a single injection of the immunotoxin ricin-mAb35 has potent and long-lasting myotoxic effects in extraocular muscles. The myotoxicity of injected ricin-mAb35 was tested in the eyelids of rabbits to determine its potential for use in the treatment of benign essential blepharospasm and other dystonias. METHODS The immunotoxin ricin-mAb35 was injec...

It has been recently shown (Larkin, J. M., M. S. Brown, J. L. Goldstein, and R. G. W. Anderson, 1983, Cell, 33:273-285) that after a hypotonic shock followed by incubation in a K+-free medium, human fibroblasts arrest their coated pit formation and therefore arrest receptor-mediated endocytosis of low density lipoprotein. We have used this technique to study the endocytosis of transferrin, diph...

The catechin, epigallocatechin gallate (eGCG), found in green tea, has inhibitory activity against a number of protein toxins and was investigated in relation to its impact upon ricin toxin (RT) in vitro. The IC(50) for RT was 0.08±0.004 ng/mL whereas the IC(50) for RT+100 μM eGCG was 3.02±0.572 ng/mL, indicating that eGCG mediated a significant (p<0.0001) reduction in ricin toxicity. This expe...

Ricin can be detected in cosmetics at 0.005 microg/mL in the analytical sample using lateral flow devices (LFDs). Wheat germ, an ingredient used in skin care products is also a potential source of wheat lectin. False positives were observed when wheat lectin was added to LFDs from two manufacturers, irrespective of whether the LFD was specific for ricin, Staphylococcus enterotoxin B (SEB), or b...

A number of compounds that interfere with glycoprotein synthesis and transport have been tested for their ability to sensitize cells to cancerostatic protein toxins. Tunicamycin, swainsonine, cycloheximide, and puromycin sensitized Vero cells and HeLa cells to abrin and ricin, as we have found previously with monensin (K. Sandvig and S. Olsnes, J. Biol. Chem., 257: 7504-7513, 1982). Cycloheximi...

Ricin is a potent toxin, with a strong potential to be used as a biologicalweapon due to itsworldwide availability, ease of production in large quantities, and thermal stability. Inhalation of ricin is likely to be the intended route for acts of bioterrorism, because ricin is easily dispersed as an aerosol. Inhalation of ricin is the most lethal route of exposure, causing diffuse pulmonary edem...

Ricin is a member of the ubiquitous family of plant and bacterial AB toxins that gain entry into the cytosol of host cells through receptor-mediated endocytosis and retrograde traffic through the trans-Golgi network (TGN) and endoplasmic reticulum (ER). While a few ricin toxin-specific neutralizing monoclonal antibodies (MAbs) have been identified, the mechanisms by which these antibodies preve...