Increased gamma-delta T-lymphocyte response to Mycobacterium bovis BCG in major histocompatibility complex class I-deficient mice.

Mice with a homologous deletion of the beta 2-microglobulin gene (beta 2m-) are deficient in class I major histocompatibility complex molecules (MHC) and consequently are deficient in CD8+ T cells. These beta 2m- mutant mice control the intraperitoneal growth of an avirulent vaccine strain of mycobacteria, Mycobacterium bovis BCG, after intraperitoneal infection similarly to normal mice. We show that beta 2m- mice have an increased gamma-delta (gamma delta) T-cell response after infection with live avirulent mycobacteria. beta 2m- mice have an earlier and more sustained rise in the proportion of intraperitoneal gamma delta T cells, averaging 17% of T cells, compared with 6% in normal mice, at 28 days after infection. Compared with the population in normal mice, gamma delta T cells in the spleens of beta 2m- mice averaged a higher proportion of the total T-cell population of the spleen on days 5, 8, and 14 after intraperitoneal infection. These data document the kinetics of gamma delta T cells reactive to mycobacterial antigens in vivo without class I MHC restriction and support a role for class I MHC and CD8+ T cells in the in vivo regulation of gamma delta T cells.

[Antagonistic effects of naloxone in analgesia and neuroleptanalgesia in the dog]. / Antagonistický úcinek naloxonu pri analgezii a neuroleptanalgezii u psa.

Antagonistic effect of naloxone was tested in two kinds of total anesthesia. In one group the preparation was tested in ten experimental dogs with neuroleptanalgesia induced by the simultaneous intramuscular application of chlorpromazine (3 mg/kg) and piritramide (4 mg/kg). After 60 minutes naloxone was applied i. m. at a dose of 0.2-0.4 mg pro toto to reverse the anesthetic effect. In another group of 15 dogs - clinical patients - the effect of naloxone was evaluated in analgesia induced by i. m. application of piritramide at a dose of 3 mg per kg with atropine premedication (0.05 mg per kg). After a surgical operation, lasting in particular cases 20-45 minutes, the same dose of naloxone was applied i. m. as in the first group to reverse the anesthetic effect. In both groups of animals naloxone application caused a reverse of the anesthetic effect of piritramide and in the first group a statistically significant reverse of the inhibition of breathing and heart action.