Alternative measures of response to Pseudomonas aeruginosa infection in Drosophila melanogaster.

Studies of invertebrate immune defence often measure genetic variation either for the fitness cost of infection or for the ability of the host to clear the parasite. These studies assume that variation in measures of resistance is related to variation in fitness costs of infection. To test this assumption, we infected strains of the fruit fly, Drosophila melanogaster, with a pathogenic bacterium. We then measured the correlation between host bacterial load and the ability to survive infection. Despite the presence of genotypic variation for both traits, bacterial load and survival post-infection were not correlated. Our results support previous arguments that individual measures of immune function and the host's ability to survive infection may be decoupled. In light of these results, we suggest that the difference between tolerance and resistance to infection, a distinction commonly found in the plant literature, may also be of value in studies of invertebrate immunity.

Cultural factors in exercise participation of older adults.

Participation motives were investigated in 81 Australian-born and 42 overseas-born older Australians (M age = 67.8 yr.) involved in community-organised exercise programs. Australians born overseas scored significantly higher on factors of Affiliation/Personal, Recognition/Achievement, and Exercise Involvement of the Participation Motivation Questionnaire but not on Fitness.

Isogeneic versus allogeneic antiserum in the prophylaxis of experimental rabies.

With a view to establishing whether rabies antiserum derived from a species genetically identical to a challenged recipient would increase or decrease its effectiveness compared with that of allogeneic antiserum, rabies immune sera produced in an inbred strain of mice and in donkeys were tested, either alone or with a course of vaccine inoculations, in mice of the same strain a few hours after intramuscular challenge with fixed CVS rabies virus. Surviving mice were bled at intervals over a year and the rabies antibodies assayed in pooled sera.There was no evidence that the isogeneic antiserum was either more or less effective than the allogeneic, nor was there a difference between the two in the decay of passive antibody; similarly, there was no marked difference in their ability to interfere with the active production of antibody resulting from the highly potent vaccine used.

Rabies neutralizing antibody response to different schedules of serum and vaccine inoculations in non-exposed persons. 4.

Early and persistent antibody is needed for maximum protection to be afforded to persons severely exposed to rabies. With vaccine alone, detectable antibody production takes 7-10 days, and the passive antibody introduced with antirabies serum or gamma-globulin is commonly used to fill this gap. However, administration of antirabies serum or gamma-globulin with vaccine interferes with the antigenic action of the vaccine.The studies reported in this paper provide further evidence that the interfering effect of serum can be overcome by giving booster doses of vaccine, as recommended by the WHO Expert Committee on Rabies, 10 and 20 days after the end of the usual 12- to 14-dose series of vaccine inoculations. While the results do not clearly indicate whether a single booster dose might be sufficient, the authors consider the second booster useful to ensure both degree and length of antibody duration.