In vitro modulation of mouse natural killer (NK) cell activity by the serum thymic factor (FTS)

Previous studies indicated that the serum thymic factor (FTS) could modulate in vivo the level of splenic natural killer (NK) cell activity in mice. The present report shows that such an effect is also observed after a short term in vitro incubation of the effector cells with FTS. The regulatory effects of FTS result in an increase or a decrease of the splenic NK cell cytotoxicity depending upon the age and the mouse strain. Furthermore, FTS is able to enhance the NK cell activity of thymus and bone marrow cells which are known to be weakly reactive in NK cytotoxicity. Depletion experiments demonstrated that the FTS-induced increase of NK cell activity was not mediated by Thy 1+ cells nor macrophages, thus suggesting a direct action of FTS on the effector cells. Comparative studies using other thymic hormones revealed similar patterns of reactivity. These results favor the hypothesis of a close relationship between the thymus and NK cells.     

Molecular weights of Cucurbita sieve tube proteins

Summary By means of SDS-polyacrylamide-gel electrophoresis, molecular weights of 15000, 28000, 59000, 116000 and 220000 were determined for the main sieve tube proteins from Cucurbita maxima.     

The transforming activity of sonicated Haemophilus influenzae DNA

Summary The inactivation of transforming Haemophilus influenzae DNA by sonication in aqueous solution was investigated. The molecular weight decrease of the molecules is the major factor in DNA inactivation. It impairs strongly the uptake of the DNA by the recipient bacteria, especially when the molecular weight is lower than 3x10⁶ daltons. The uptake of sonicated DNA by the bacterial cells seems not to be further reduced when molecules of about 0.5x10⁶ daltons are submitted to further depolymerisation. However the transforming activity of these molecules is still sensitive to further sonication. The transforming activity of the sonicated DNA is related in the last resort to the intact length of the DNA molecules, at the level of their single-strand structure, available for recombination. Rupture by ultrasound was found to be twice as efficient in reducing transforming activity as a nick induced by pancreatic DNAse.     

Enteroviral and Mumps Meningitis in Toronto, 1963

Virological investigations of 115 children with the aseptic meningitis syndrome during 1963 resulted in the isolation of enteroviruses from cerebrospinal fluid (CSF) and/or feces of 21 of 48 children who had no association with mumps. For the third successive year, Echo 9 was the dominant enterovirus in cases of aseptic meningitis in Toronto children, but no rashes were associated with Echo 9 meningitis during 1963, in contradistinction to previous years. Mumps virus was isolated from CSF of 25 patients by inoculation of rhesus monkey kidney cultures, and rising or elevated mumps antihemagglutinin titres in paired sera from a further 33 cases provided laboratory evidence of infection with mumps virus in 58 of 67 patients with mumps meningoencephalitis. No enlargement of salivary glands was noted in 20 laboratory-proved cases of mumps meningoencephalitis. Enteroviral meningitis occurred principally during summer, but the peak of mumps meningoencephalitis occurred during late winter.     

Characterization of histamine H1 binding sites on human T lymphocytes by means of 125I-iodobolpyramine. Preferential expression of H1 receptors on CD8 T lymphocytes

The presence of histamine H1 receptors on lymphocytes has been indirectly suggested by the various effects of agonists or antagonists on the functionally distinct T lymphocyte subsets. Recently, a new H1 antagonist, 125I-iodobolpyramine, whose structure is similar to mepyramine, has become available for the detection of H1 receptors in guinea pig brain. When using 125I-iodobolpyramine on human T lymphocytes, the presence of a single highly specific H1 binding site was evidenced. The binding of 125I-iodobolpyramine to human T cells was reversible when using 1000-fold excess of the cold H1 antagonist, d-chlorpheniramine. Binding saturation was achieved at 0.60-0.65 nM of 125I-iodobolpyramine, the binding equilibrium was reached in 20-30 min at 27 degrees C. The dissociation constant was KD = 0.41 +/- 0.07 (mean +/- SE) and the number of receptors per T cell was 3407 +/- 592 (mean +/- SE) as deduced from saturation and kinetic curves. In competition experiments using a panel of H1 ligands, the T cell binding sites detected by 125I-iodobolpyramine showed a pharmacological behavior characteristic of histamine H1 receptors. It was of particular interest that 125I-iodobolpyramine binding displayed clearcut stereoselectivity as assessed by the higher affinity of the d-configuration of chlorpheniramine than the l form. Study of purified CD4 and CD8 T cells showed that twice as much H1 histamine receptors were expressed by CD8 T lymphocytes (6615 +/- 1125) as compared to CD4 T cells (3545 +/- 459). These results underline the need for studying the functional properties of such pharmacologically defined T lymphocyte H1 binding sites.     

Increase in plasma 5 alpha-androstane-3 alpha,17 beta-diol glucuronide as a marker of peripheral androgen action in hirsutism: a side-effect induced by cyclosporine A

Dose-dependent hypertrichosis is a common dermatological side-effect affecting the majority of patients treated with cyclosporine A (CSA). Previous studies have not demonstrated the influence of CSA on specific sex hormone levels. The aim of this study is to investigate whether CSA increases the activity of 5 alpha-reductase, an enzyme which transforms androgens into dihydrotestosterone in peripheral tissues. The metabolite which best reflects this activity is 5 alpha-androstane-3 alpha,17 beta-diol glucuronide (Adiol G). The study was carried out on 49 insulin-dependent diabetes patients participating in the double-blind "Cyclosporine-Diabète-France" clinical trial, of which 28 were treated with CSA (16 males and 12 females), and 21 received only placebo (10 males and 11 females). All patients underwent extensive clinical and laboratory evaluations prior to and during the present study. In addition to Adiol G, testosterone (T), dehydroepiandrosterone sulfate (DHEA S) and sex hormone-binding globulin (SHBG) were assayed. Levels of Adiol G increased significantly in CSA-treated groups: males, 11.86 +/- 2.58 vs 7.83 +/- 2.30 nmol/l; females, 4.48 +/- 2.70 vs 2.10 +/- 1.22 nmol/l; P less than 0.02 (comparison of means). There were no significant differences in this parameter before and during treatment in either the male or female placebo groups (paired t-test). During the treatment period, T, DHEA S, SHBG and the T/SHBG ratio did not significantly change with respect to their baseline values in any of the groups studied (comparison of means). Comparison (using paired t-test) showed a significant increase of DHEA S in CSA-treated groups: males, delta = 3.08 +/- 3.33 nmol/l, P less than 0.01; females, delta = 0.98 +/- 1.13 nmol/l, P less than 0.05. In conclusion, it is possible that CSA induces hypertrichosis or hirsutism by increasing 5 alpha-reductase activity in peripheral tissues. Nevertheless the role of increased DHEA S as a possible Adiol G precursor cannot be excluded.