limitations. In a longitudinal study of visceral leishmaniasis in Bangladesh, Bern et al. reported loss of LST sensitivity attributed to antigen-production issues, such as standardization and documentation of sensitivity, potency, and stability of leishmanin antigens (5). Also, prior treatment with immunosuppressive agents, which influence cell-mediated immunity, may decrease LST prognostic pot...

A 10% suckling rat brain rabies vaccine free from encephalitogenic activity was prepared and inactivated with 1:8,000 beta-propiolactone (BPL), or ultraviolet light, or a combination of ultraviolet light and BPL, or 1% phenol. Potency was excellent in all samples, with the exception of the phenolized product which was marginal. A purified suckling rat brain (SRB) vaccine prepared by zonal centr...

The Carcinogenic Potency Database (CPDB) is an easily accessible, standardized resource of positive and negative long-term animal cancer tests. The CPDB has been published in four earlier papers that include results for approximately 4000 experiments on 1050 chemicals. This paper describes the CPDB: goals, inclusion criteria, fields of information, and published plot format. It also presents an...

The ultraviolet absorption spectrum of vitamin A with itsmaximum near 328 m,. was described nearly 20 years ago (Morton & Heilbron, 1928a, b). The intensity of absorption shown at that wave length by a fish-liver oil or concentrate was conveniently expressed in terms of E "lo 328 m,u. (Gillam & Morton, 1929), and this magnitude was early seen to afford a guide to potency. If a number of fish-li...

Three combined triple antigen vaccines were used to inoculate infants receiving primary immunization at 3 to 6 months of age. Laboratory potency and toxicity tests and clinical evaluation again showed that the mouse weight gain test is able to predict which vaccines will give reactions in children. The addition of aluminium hydroxide to the vaccine both increased potency and reduced the tendenc...

Fossil diesel fuel and rape seed oil methylester are compared with regard to exhaust gas emissions and effects of these emissions on human health and the environment. Tests were carried out using an agricultural tractor and a test engine. The aspects treated are: use of blends, particle sizes, mutagenic potency of the particulate matter, and ozone precursors. Whereas slight disadvantages of bio...

Before any given lot of insulin can be marketed, its potency and stability must meet certain requirements. Stability is arbitrarily determined by subjecting a sample of insulin to a “heat test.” This test consists of exposing the carefully standardized insulin to a temperature of 52” for 10 days. The potency of the “heated” material is then compared either with a standard insulin or with a samp...

Curtailing the observation of mice challenged with tetanus toxin in potency test of tetanus vaccine would reduce the agony of mice from spastic paralysis. From the viewpoint of animal welfare, we investigated the feasibility this measure. The potencies of 85 lots of vaccine obtained on the 4th day after challenge were compared with those obtained on the seventh day. No significant difference wa...

There is currently no International Standard suitable for the standardization of assays of vaccines from the manufacturer. The manufacturer has therefore established a product-specific reference preparation which is traceable to a lot of vaccine shown to be efficacious in clinical trials. This vaccine will serve as a working standard and will be included in all potency tests. The NRA approves t...