Winston H. Price

The mechanism of cross-protection afforded by dengue virus against West Nile virus in hamsters.

The protection afforded by similar concentrations of different dengue virus serotypes against a subsequent challenge of West Nile virus was studied in hamsters. The New Guinea C strain of dengue 2 virus gave the best protection. It was found that the anamnestic neutralizing antibody response induced by the challenge West Nile virus against West Nile virus in hamsters, previously immunized with dengue 2 virus, might play a major role in the cross-protection observed in this system.

DISC ELECTROPHORESIS ON POLYACRYLAMIDE GELS OF SERUM MUCOIDS OF INDIVIDUALS WITH SELECTED CHRONIC DISEASES.

A reproducible method is described for fractionating the seromucoid component of human serum by disc electrophoresis with polyacrylamide gels. Preliminary results suggest there may be at least five distinct patterns of the seromucoid fractions in testing sera from healthy individuals and patients with a variety of diseases. The significance of differences in patterns remains to be determined.

Interference phenomenon in animal infections with rickettsiae of Rocky Mountain spotted fever.

Summary 1. Eighty to 90% of the guinea pigs infected intraperitoneally with a strain of low virulence of R. rickettsii were protected against a simultaneous injection of a highly virulent strain of spotted fever, or boutonneuse fever, provided the low virulent strain was given in about 10 to 30 times the concentration of the virulent strain. 2. Infection with rickettsiae of Q fever, scrub typhus, endemic typhus, and epidemic typhus protected guinea pigs against a virulent strain of spotted fever under the above conditions. 3. Columbian ground squirrels, field mice (Microtus), and cottontail rabbits were infected by exposure to many D. andersoni containing a low virulent strain of Rocky Mountain spotted fever and a few D. andersoni containing a highly virulent strain. Uninfected ticks fed upon these animals were found to contain only the low virulent strain.