Historical overview of vaccines.

This article focuses on a few significant milestones in the history of vaccination. As the contributions of key investigators, such as Jenner, Pasteur, and Salk were slowly accepted, the developments and discoveries that followed pushed ahead the science of vaccinology. The article also recognizes the accomplishments of the World Health Organization and concludes with a short synopsis of vaccines being developed for the future.

Effect of plasma from premenstrual syndrome and control patients on human platelet and rat brain synaptosome monoamine oxidase B activity.

The present study determined the kinetic properties of platelet monoamine oxidase (MAO) in patients with premenstrual syndrome (PMS) and control subjects during the pre- and postmenstrual intervals. In addition, we investigated the effects of plasma obtained during the pre- and postmenstrual intervals from both subject groups on MAO activity in washed human platelets and rat brain synaptosomes. The Vmax of platelet MAO in postmenstrual PMS patients was significantly less than that during the premenstrual phase. Plasma from both subject groups (10-100 microliters) inhibited platelet and synaptosomal MAO in a dose-dependent manner to approximately the same degree at each time interval. The results indicate that although human plasma contains endogenous substances which inhibit MAO activity, alterations in their concentration are probably not responsible for the previously reported transient changes in platelet MAO activity in PMS.

Alteration of 5-HT uptake by plasma fractions in the premenstrual syndrome.

The effects of plasma and an aqueous plasma fraction from patients with premenstrual syndrome (PMS) and control subjects on the uptake of 5-hydroxytryptamine (5-HT) in washed human platelets and rat forebrain synaptosomes were studied. Pre- and postmenstrual samples of unextracted plasma from the control group significantly enhanced platelet uptake of 5-HT. In contrast, an aqueous fraction following extraction of the plasma with organic solvents caused a dose-dependent decrease of 5-HT uptake. Plasma obtained from patients with PMS caused less stimulation of 5-HT uptake compared to plasma from the control group. The aqueous fraction of premenstrual plasma from patients tended to inhibit 5-HT uptake to a greater extent than a similar plasma fraction from controls. The inhibition of 5-HT uptake was associated with an increase in Km. Aqueous plasma fractions from both groups also inhibited 5-HT uptake in brain synaptosomes. However, there were no significant differences between groups. The results of the platelet study suggest that there may be quantitative differences in the plasma concentration of endogenous factors that affect 5-HT uptake between patients with PMS and control subjects and that such differences may explain the previously reported alteration of platelet 5-HT uptake and content associated with PMS symptoms.

Alteration of platelet serotonergic mechanisms and monoamine oxidase activity in premenstrual syndrome.

Platelet uptake and content of 5-hydroxytryptamine (5-HT), platelet monoamine oxidase (MAO) activity, and plasma free and total tryptophan levels were determined in patients diagnosed with premenstrual syndrome (PMS) and in control subjects. The Vmax of 5-HT uptake and 5-HT content in platelets of PMS patients were significantly decreased during the premenstrual phase (cycle days -9 to -1) compared to control subjects. Platelet MAO activity was significantly lower postmenstrually (cycle days 5-9) in PMS patients compared to the premenstrual phase. There were no differences in plasma free and total tryptophan levels between PMS patients and control subjects during either interval. As platelets are believed to be a peripheral model for central serotonergic neurons, the results suggest that PMS symptomatology may be related to alterations in serotonergic neuronal mechanisms.