Ultrastructure of the hemocytes of Cetonischema aeruginosa larvae (Coleoptera, Scarabaeidae): involvement of both granulocytes and oenocytoids in in vivo phagocytosis.

In the context of comparative studies on immunity defence mechanisms of adults and larvae of the coleopteran Cetonischema aeruginosa (Drury, 1770) the ultrastructure of the circulating hemocytes of the third instar larval stage has been investigated by means of light and transmission electron microscopy (TEM). Six types of hemocytes were found in the hemolymph of C. aeruginosa and they were identified as prohemocytes, granulocytes, plasmatocytes, coagulocytes, oenocytoids and spherule cells. In order to identify the "professional" phagocyte cell, phagocytosis assays were performed in vivo by injection of 0.9 microm carboxylate-modified polystyrene latex beads. It was demonstrated that the granulocytes and the oenocytoids of C. aeruginosa were the only hemocyte types involved in this cellular response.

Recognition of a 31,000 molecular weight protein synthesized by the mussel Mytilus galloprovincialis Lmk. during Dinophysis spp. algal bloom in the Gulf of Trieste (upper Adriatic Sea).

During Dinophysis spp. bloom, a histological alteration in the digestive gland of Mytilus galloprovincialis Lmk. occurs. Electrophoretic analysis of the water-soluble proteins of the hepatopancreas showed the presence of a low mol. wt protein, which appeared after the ingestion of algae by mussels. The probable relationship between the toxicity of Dinophysis and the synthesis of the new protein by mussels prompted us to produce a monoclonal antibody against this protein because it should be useful for the identification of mussel toxicity.

Identification and partial characterization of a cytolytic toxin produced by Gardnerella vaginalis.

Generation and release into the culture medium of a cytolytic toxin by Gardnerella vaginalis has been demonstrated. Addition of starch and of the nonionic detergent Tween 80 to the culture medium was essential to recover cytolytic activity. A protein with an apparent molecular mass of 61 to 63 kDa was purified from the culture supernatants showing lytic activity towards erythrocytes and nucleated cells, such as human endothelial cells and human neutrophils. The protein had marked selectivity for human erythrocytes, while erythrocytes from other species were not lysed or were lysed at much higher concentrations of the protein than those needed for human erythrocytes. The cytolytic activity was remarkably unstable in polar media, but was stabilized by nonionic detergents, by binding, or by insertion into the target cell membrane, suggesting its amphiphilic nature.

Production of heteroagglutinins in haemocytes of Leucophaea maderae L.

It was our purpose to study the immunological activity of circulating fluid cells in the blattoid insect Leucophaea maderae L. These cells are generically called haemocytes; after a preliminary morphological study under optical microscope, they were treated with anti-heteroagglutinins serum marked with fluorescein isothiocyanate. Thus, it was possible to show the presence of heteroagglutinins into the cytoplasm, as regards one group of haemocytes, and on the cell membrane for the second group.