Search

Sono state studiate le costanti apparenti di associazione di vari cationi per il cell-wall isolato di cellule diStaphylococcus aureus. E' risultato che gli ioni monovalenti presentano una bassa costante di associazione mentre gli ioni bivalenti e trivalenti presentano valori nettamente superiori delle costanti di associazione. Si conclude che mentre i cationi monovalenti sono legati da deboli legami elettrostatici, i cationi di valenza superiore formano con i gruppi dissociabili legami ionici stabili.

Major outer membrane proteins of Eikenella corrodens, an organism frequently isolated from patients with periodontal disease, were tested for some biological activities. Mouse peritoneal macrophages, exposed at low concentrations of the above-mentioned proteins (between 0.05 and 5 micrograms/ml), showed evident and marked morphological modifications consisting of increases in the size and vacuolation of the cells. Higher concentrations showed a toxic effect. Low concentrations resulted in a selective release of lysosomal enzymes without any significant release of lactatedehydrogenase, and cytoplasmic marker; while concentrations of 25-50 micrograms/ml, which were toxic in trypan-blue exclusion test, increased LDH release. Eikenella corrodens major proteins increased the platelet aggregation of ADP and thrombin. The residual complement activity of serum samples incubated with various amounts of proteins at 37 degrees C for 30 minutes appeared strongly reduced with respect to controls, thus showing a consumption of the complement components. These results suggested that Eikenella corrodens major proteins may play a role in the development of periodontal lesions.