The folate binding proteins.

Folates are essential molecules for cell life and, not surprisingly, their transport in biological fluids and their transfer to cells are finely regulated. Folate binding proteins play a major role in this regulation. This paper will review our knowledge on these proteins and examine the most recent advances in this field.     

Ultrastructural investigations on the question of mechanical activation of blood platelets

Summary The present study addresses the question whether platelets are activated by mechanical stresses as they occur in pathologically accelerated blood flow. Their potential mechanoreceptive properties were tested by subjecting human platelets to defined fluid mechanical forces for periods of milliseconds. Platelet activation was assessed by quantitative morphology, revealing besides activated platelets, irreversibly ballooned, lytic platelets. However, this morphometrically documented shear activation of platelets can be suppressed almost completely by the addition of enzyme-substrate systems, capable of removing adenosine diphosphate from the suspending medium. This is in keeping with a recent study from our laboratory [27] showing that the behaviour of lactic dehydrogenase as marker for platelet lysis and -thromboglobulin as release marker refuted earlier data, suggesting a direct activation of platelets by shear. It is concluded that former evidence of shear induced platelet activation must be interpreted as the consequence of lytic damage to a small proportion of platelets.     

Gold binding to blood cells and serum proteins during chrysotherapy.

The binding of gold to peripheral erythrocytes and serum protein fractions was studied during chrysotherapy of 1 to 2 years' duration in 43 patients with rheumatoid arthritis. In 45% of the patients more than 10% of the gold was found to be strongly bound to blood cells. 5--15% of the metal is bound to non-albumin protein fractions at serum gold concentrations larger than 2 microgram/ml. In contrast to the cellular binding of gold the relative binding of gold to non-albumin proteins was inversely proportional to the serum concentrations. Binding to neither blood cells nor to non-albumin protein fractions was found to be correlated with clinical parameters.