The challenge of emerging and re-emerging infectious diseases

Infectious diseases have for centuries ranked with wars and famine as major challenges to human progress and survival. They remain among the leading causes of death and disability worldwide. Against a constant background of established infections, epidemics of new and old infectious diseases periodically emerge, greatly magnifying the global burden of infections. Studies of these emerging infections reveal the evolutionary properties of pathogenic microorganisms and the dynamic relationships between microorganisms, their hosts and the environment.     

A synthetic peptide that is a bombesin receptor antagonist

The tetradecapeptide bombesin was originally isolated from frog skin. Bombesin-like peptides have since been detected in mammalian gastrointestinal tract, brain and lung. These peptides have potent pharmacological effects on the central nervous system; they cause contraction of intestinal, uterine and urinary tract smooth muscle; and stimulate the release of other peptides including gastrin, cholecystokinin, motilin, pancreatic polypeptide, neurotensin, insulin, enteroglucagon, prolactin and growth hormone. Specific plasma membrane receptors for bombesin have been demonstrated on pancreatic acinar cells, brain membranes and pituitary cells. Studies defining the physiological importance of bombesin have been impeded by the lack of a bombesin receptor antagonist. Here we describe experiments which demonstrate that a peptide originally described as a substance P receptor antagonist, [D-Arg, D-Pro, D-Trp, Leu ]substance P, is also a bombesin receptor antagonist. This peptide competitively inhibits the ability of bombesin to stimulate enzyme secretion from dispersed pancreatic acini, and also inhibits the action of other peptides that interact with the bombesin receptor.     

Long-term administration of a substance P antagonist, (D-Pro2, D-Trp7,9)-SP,abolishes the response to ocular trauma

Summary The long-term effect of ocular administration of a substance P (SP) antagonist, (D-Pro², D-Trp^7,9)-SP, was studied in the rabbit. After 2–3 months of topical administration of the antagonist twice daily, a mild trauma was applied in the form of infrared irradiation of the iris. The control eye responded with disruption of the blood-aqueous barrier, the eye treated with the antagonist did not. Two days after termination of treatment, the response to ocular injury was still reduced. Another 2 days later, ocular injury evoked a normal response, which shows that the protection was reversible. No adverse reaction to the SP antagonist was noted.