Comparative Study of Optical Markers to Assess Bait System Efficiency Concerning Vaccine Release in the Oral Cavity of Dogs

Oral vaccination of dogs against rabies has the potential to achieve mass coverage and thus deplete the virus of its most important reservoir host species. There is, however, no established non-invasive method to evaluate vaccine release in the oral cavity, following bait ingestion. In this study, two pre-selected marker methods in conjunction with their acceptance were assessed in local Thai dogs. Shelter dogs (n = 47) were offered one of four randomized bait formulations; bait type A-, containing Green S (E142) in a fructose solution; type B-, containing Patent Blue V (E131) in a fructose solution; type C-, containing the medium used for delivery of oral rabies vaccine in baits commercially produced; and type D-, containing denatonium benzoate, which was to serve as the negative control, due to its perceived bitterness. Patent Blue V was found to possess overall stronger dyeing capacities compared to Green S. Furthermore, there was no significant difference in the acceptance or bait handling of Patent Blue V baits compared to those containing the oral rabies vaccine medium alone, suggesting the potential use of this dye as a surrogate for rabies vaccine when testing newly developed bait formats.

Natural Blues: Structure Meets Function in Anthocyanins

Choices of blue food colourants are extremely limited, with only two options in the USA, synthetic blue no. 1 and no. 2, and a third available in Europe, patent blue V. The food industry is investing heavily in finding naturally derived replacements, with limited success to date. Here, we review the complex and multifold mechanisms whereby blue pigmentation by anthocyanins is achieved in nature. Our aim is to explain how structure determines the functionality of anthocyanin pigments, particularly their colour and their stability. Where possible, we describe the impact of progressive decorations on colour and stability, drawn from extensive but diverse physico-chemical studies. We also consider briefly how this understanding could be harnessed to develop blue food colourants on the basis of the understanding of how anthocyanins create blues in nature.

Hemoadsorption to treat severe iatrogenic intoxication with Patent Blue: a case report

Background Intoxication with Patent Blue V [sodium compound of (diethylamino-4-phenyl)(hydroxy-5-disulfo-2,4-phenyl) methanol] can lead to high levels of methemoglobin and metabolic acidosis. In severe cases and if not rapidly eliminated from the plasma, this can lead to multiple organ failure and death. Case report A 27-year-old Asian woman (original from Vietnam) was admitted after ecstasy intoxication resulting in multi-organ failure (acute respiratory distress syndrome, metabolic acidosis, capillary leakage syndrome, renal failure, shock refractory to standard resuscitation). As a consequence, continuous renal replacement therapy and veno-venous extracorporeal membrane oxygenation were started. Methylene blue administration to reverse vasoplegia was decided, but unfortunately, Patent Blue V was erroneously administered, resulting in a severe clinical picture of methemoglobinemia and tissue hypoxia. As a therapeutic intervention, CytoSorb hemoadsorption was initiated, and rapid and significant reduction in plasma methemoglobin, accompanied by improved hemodynamics and normalization in plasma lactate levels, was observed. Conclusions This is the first case describing the application of CytoSorb hemoadsorption in a patient with ecstasy intoxication complicated by iatrogenic administration of Patent Blue V. There is a potential role for CytoSorb in drug intoxication, which needs to be confirmed in larger series.