Nonspecific and antigen-specific adhesiveness of circulating lymphocytes in dysentery patients undergoing combined therapy using thymalin and indomethacin

Nonspecific adhesiveness of lymphocytes to polyacrylonitrile fiber and the antigen-specific adhesiveness of T-lymphocytes to Shigella flexneri pellicular immunosorbent have been studied in dysentery patients. Short courses of treatment with indomethacin, but not with thymalin (the preparation of thymic hormones), used for immunomodulation, have accelerated the normalization of nonspecific lymphocyte adhesiveness during regression of the disease, while indomethacin, in contrast to thymalin, inhibits antigen-specific T-lymphocyte adhesiveness which increases with the development of immune response.     

The 76 kD cell-adhesion factor from crayfish haemocytes promotes encapsulation in vitro

Summary Semigranular cells from the crayfish, Pacifastacus leniusculus, were separated by Percoll gradient centrifugation and were used to study the encapsulation of foreign particles. The semigranular cells were found strongly to encapsulate glass beads coated with haemocyte lysate in which the prophenoloxidase-activating system had been activated with laminarin or with a low concentration of calcium ions. The granular cells only weakly encapsulated these particles. The encapsulationpromoting factor was purified from haemocyte lysates and found to be a 76 kD protein which was recognized by an antiserum to the previously described 76 kD cell-adhesion factor. After the last step in purification (Con A-Sepharose chromatography), the flowthrough consisted of several proteins, which had some, but less, encapsulation-promoting activity and contained a 30 kD band that was also recognized by the antiserum to the 76 kD cell-adhesion factor. If the haemocyte lysate prepared in low [Ca²⁺] was incubated with a -1,3-glucan prior to purification, no 76 kD protein could be isolated but only a 30 kD protein. The 30 kD protein thus seems to be a degradation product of the 76 kD cell-adhesion factor. We conclude that the 76 kD protein which is released from degranulating haemocytes, and to a lesser extent its 30 kD fragment, can promote encapsulation. Phenoloxidase did not have any encapsulation-promoting activity.     

Iodine binding and peroxidase activity in the endostyle of Salpa fusiformis,Thalia democratica,Dolioletta gegenbauri and Doliolum nationalis (Tunicata,Thaliacea)

Summary The protothyroid region in the endostyles of four species of tunicates was examined by means of autoradiography and cytochemistry, at both the light and electronmicroscopic levels. To reveal the primary binding site for iodine, autoradiography was carried out on endostylar tissue from animals that had been incubated with high activity ¹²⁵I^- over a short period of time. The specific iodine binding enzyme, a peroxidase, was traced by its reaction with DAB. In accordance with previous findings, the iodinebinding cells proved to be the same as those containing the peroxidase. There were also strong indications of a secondary uptake of iodinated compounds and subsequent release into the body fluid. Together with the ultrastructural features, the data provided strong evidence indicating that these cells constitute a protothyroid region, which partly functions as an endocrine organ, possibly homologous with the vertebrate thyroid gland. Since the number of zones varied between the species, the numeration of the protothyroid region also varied. However, in all the examined endostyles, the protothyroid region was seen to be situated dorsolaterally to the glandular regions of the endostyle concerned with food capture.