Neutralising Antibodies against Ricin Toxin

The Centers for Disease Control and Prevention have listed the potential bioweapon ricin as a Category B Agent. Ricin is a so-called A/B toxin produced by plants and is one of the deadliest molecules known. It is easy to prepare and no curative treatment is available. An immunotherapeutic approach could be of interest to attenuate or neutralise the effects of the toxin. We sought to characterise neutralising monoclonal antibodies against ricin and to develop an effective therapy. For this purpose, mouse monoclonal antibodies (mAbs) were produced against the two chains of ricin toxin (RTA and RTB). Seven mAbs were selected for their capacity to neutralise the cytotoxic effects of ricin in vitro. Three of these, two anti-RTB (RB34 and RB37) and one anti-RTA (RA36), when used in combination improved neutralising capacity in vitro with an IC50 of 31 ng/ml. Passive administration of association of these three mixed mAbs (4.7 µg) protected mice from intranasal challenges with ricin (5 LD50). Among those three antibodies, anti-RTB antibodies protected mice more efficiently than the anti-RTA antibody. The combination of the three antibodies protected mice up to 7.5 hours after ricin challenge. The strong in vivo neutralising capacity of this three mAbs combination makes it potentially useful for immunotherapeutic purposes in the case of ricin poisoning or possibly for prevention

Delayed seizure-like activity following analytically confirmed use of previously unreported synthetic cannabinoid analogues

Synthetic cannabinoid use has become widespread, leading to increased burdens on health care providers. Symptoms range from agitation and psychosis to seizures and acute kidney injury. We report a case where a patient was assessed and treated twice within 12 h for seizures following synthetic cannabinoid intoxication. Blood sample determinations showed low concentrations of analogues not previously reported, some of which are legal. Clinicians should be aware that synthetic cannabinoids may cause an array of severe health consequences. Given the ever evolving structure of available analogues, clinicians must also be prepared for other unexpected adverse effects. </jats:p