Purification and characterization of digitalislike factors from human plasma.

Increased levels of a humoral inhibitor of active sodium transport have been associated with the response to acute and chronic hypervolemia and various forms of experimental as well as human essential hypertension. In this report, we describe the purification of inhibitors of Na+, K+-adenosine triphosphatase (ATPase) from the plasma of volume-expanded individuals. Of the two amphipathic materials obtained, only one of the factors when present in high concentrations showed the slow time-dependent component of inactivation similar to that of the cardiac glycosides.

Determination of lead and cadmium in foods by anodic stripping voltammetry: II. Collaborative study.

A dry ash anodic stripping voltammetric method for determining lead and cadmium in foods was collaboratively studied by 20 laboratories. The food commodities studied were strained green beans, beef (baby food), fish (mackerel), infant formula (milk base), apple juice, and cereal (wheat farina). Each collaborator analyzed 3 commodities, each consisting of 2 duplicate lead and cadmium fortification levels, for a total of 4 samples for each commodity.