Mario R. Castaneda

Learn More
In a preceding paper from this laboratory, Zinsser and Castaneda (1) reported upon the development of a method by which reliable agglutination reactions could be obtained, with Rickettsia suspensions, in sera from convalescent typhus patients and in those of convalescent or vaccinated animals. The experiments carried out by this method showed a definite(More)
THE VIRUS OF MEXICAN TYPHUS HAS BEEN SHOWN TO MULTIPLY ABUNDANTLY IN THE FOLLOWING SPECIES OF FLEAS: Xenopsylla cheopis, Ceratophyllus fasciatus, Leptopsylla musculi, Ctenocephalus canis, Ctenocephalus felis. In all fleas, Rickettsia prowazeki was demonstrated within the epithelial cells of the stomach and within the cells of the Malpighian tubules. Whereas(More)
In a communication published in April, 1932 (1), the writers described a method of obtaining large numbers of Rickettsiae by the inoculation of rats previously exposed to severe short wavelength X-ray radiation. The primary purpose of these experiments was to supply us with Rickettsia material for further study of active immunization against typhus fever.(More)
In a preceding (1) communication we have reported upon experiments in which we succeeded, in a certain number of rats treated with benzol, in obtaining large numbers of Rickettsiae of the Mooser type in the peritoneum as well as in the tunica and in many organs in which Rickettsiae had not been previously observed. In some of these rats we found(More)
THE EXPERIMENTS RECORDED ABOVE HAVE DEMONSTRATED THE FOLLOWING POINTS: 1. Scrotal swelling can appear in guinea pigs directly inoculated from a human case of Mexican typhus fever. 2. In certain strains of this disease, a number of generations of guinea pigs may show absolutely no scrotal swelling, which, however, may reappear in subsequent animals,(More)
1. The absorption of typhus sera (human or antityphus horse serum) with Proteus X-19 removes only the Proteus agglutinins, leaving the Rickettsia agglutinins intact. 2. The absorption of typhus sera with Mexican Rickettsiae removes the agglutinins for both the Rickettsia and Proteus X-19. 3. While normal or formalinized Rickettsiae are not agglutinated by(More)
Polyplax spinulosus, the common rat louse, is easily infected with the virus of typhus by feeding on infected rats. As in the case of Pediculus humanus, such feedings are followed by the appearance of large numbers of Rickettsia prowazeki within the gut of the insect. The virus of Mexican typhus can be transmitted from rat to rat by Polyplax spinulosus by(More)
The above experiments demonstrate that guinea pigs and rats subjected to vitamin-deficient diets to a point at which deficiency symptoms appear, and then inoculated with typhus virus, exhibit clinical pictures which indicate a far more severe infection than that observed in normal animals after inoculation. There is also a wider distribution of Rickettsiae(More)
Two substances differing in immunological behavior as well as in certain chemical properties have been isolated from soluble extracts of B. proteus X-19. Both substances appear to be polysaccharides. The first substance is precipitated from X-19 crude extracts by a relatively low percentage of alcohol and electrolytes (from one to two and a half volumes of(More)
  • 1