Coagulation of blood plasma of guinea pig by the bone matrix.

Optimal amounts of demineralized bone matrix possess the ability to coagulate platelet-free heparinized, citrated, and oxalated blood plasmas of guinea pigs. Clotting constituents become denatured in contact with the insoluble coagulant proteins. Quantities in excess of optimal modify plasma so that it does not gel when thrombin is added.

Biochemical sequences in the transformation of normal fibroblasts in adolescent rats.

Coarse powders of acid-insoluble matrix of diaphysis and calvarial parietal bone rapidly and consistently transformed fibroblasts into masses of cartilage and bone containing hemopoietic marrow. The transformant was encapsulated by fibroblasts within 24 hr to form a plaque. Transformation was restricted to the central thicknesses of the plaque.

Protein phospholinase reactions in mammalian testis. Stimulatory effects of adenosine 3':5'-cyclic monophosphate on the phosphorylation of basic proteins.

The soluble fraction of rat testis homogenates is rich in enzymes catalysing the phosphorylation by ATP of many different proteins. The phosphorylation of certain histones, and also of a homogeneous basic protein from guinea-pig seminal-vesicle secretion, is markedly enhanced by 3':5'-cyclic AMP. Various factors affecting these reactions as catalysed by partially purified testicular enzyme preparations are described, and their possible physiological significance is discussed.

Transformation of fibroblasts by allogeneic and xenogeneic transplants of demineralized tooth and bone.

Xenogeneic transplants of powdered, dehydrated, demineralized matrix of bone and tooth were well tolerated in three species of rodents. Differences between the species were found in competence of fibroblasts to be transformed into cartilage and bone in vivo by these preparations. Rat fibroblasts were most susceptible to transformation of this sort; they were transformed by demineralized dentin of guinea pig, mouse, and rat, and to a limited extent, by a specimen of decalcified human bone.