Mario R. Castaneda

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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)
Our experiments have shown that the Mooser bodies or Rickettsiae derived from guinea pigs with Mexican typhus fever can survive in bedbugs after intra-coelomic injection for 10 days, remaining capable of infection. We have also succeeded in similarly infecting bedbugs by allowing them to feed on benzolized rats in whose blood Rickettsiae had been shown to(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)
The intradermal inoculation of Mexican typhus virus into immune guinea pigs produces a local reaction which is similar in its appearance to the lesion observed in the skin of normal animals submitted to the same treatment. The reaction in the immune animal appears earlier and fades sooner than the lesion in the normal guinea pig. The inoculation of(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)
This study of the lesions produced in the skin of guinea pigs inoculated intracutaneously with Mexican typhus virus, shows that there is an early polymorphonuclear response at the point of inoculation. As early as 24 hours after the virus is given, a mononuclear phagocytic infiltration, which is more pronounced around the larger vessels of the corium,(More)
PRECISE INTERPRETATION OF OUR EXPERIMENTS SEEMS TO IMPOSE THE FOLLOWING CONCLUSIONS: Guinea pigs inoculated with washed Rickettsiae from Mexican typhus fever develop a disease identical with that resulting from inoculations with whole tunica scrapings, blood or other virulent material, and become thereby immunized to European typhus fever. The etiological(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)