Insulin at 25, 50, 250, 500 and 1000 mcU/ml concentration added to lymphocyte cultures under PHA stimulation increases [3H] Thymidine incorporation. Maximum effect is obtained at 50 mcg/ml of PHA and 250 mcU/ml of insulin after 96 hours of incubation. Insulin stimulates cultures when it is added between the 12th and the 24th hour. Cultures stimulated wih high dose (250 mcg/ml) of PHA do not show any increase in mitosis. Ours and other Authors results seem to show that the mechanism of action of insulin works through specific receptors on lymphocytes. These receptors appear some hours after mitogen stimulation; our results showing maximum effect when insulin is added after 12-24 hours support this hypothesis.

Humans↗

PubMedDate not supplied

[In vitro lymphocyte immunoreactivity in sarcoidosis patients. Stimulation with Kveim antigens].

12 patients suffering from sarcoidosis have been studied in addition to clinical and bioptic investigations, they were submitted to intradermal reaction with PPD, Candida Albicans and Kveim's antigen. Lymphocytes from the 12 patients were placed in culture and stimulated with phytohaemagglutinin (PHA), pokeweed mitogen (PWM), concanavalin A (CON-A), PPD, Candidin and Kveim's antigen. Six patients proved positive to Kveim's antigen in vivo, and four of them (66%) in vitro also. No patient was immunodepressed. Of the 6 patients negative to Kveim's antigen both in vivo and in vitro, 4 were clearly immunodepressed, as shown by the reduced mitogen response, the negative response to antigen stimulation, and to the intradermal reaction. The results are discussed in the light of recent findings regarding the role of the immunocompetent system in sarcoidosis.

Adult↗

PubMedDate not supplied

[Active E rosette test in the study of PPD hypersensitivity].

In our study we show that pre-incubation of lymphocytes with PPD "in vitro", produces a significant increase in the number of E active rosettes. This increase is only for subjects with cutaneous hypersensitivity to tuberculin. We think this is a specific test and we studied the confidence interval for our results. We discuss the possibility to evaluate the immune-status of a subject, testing his lymphocytes with a panel of antigens. The active E rosette test is simpler, cheaper and easier to perform than other tests to evaluate the cellular immune-status of patients.

Adult↗