scholarly journals A CYTOLOGICAL STUDY OF THE NATURE OF RICKETTSIA IN ROCKY MOUNTAIN SPOTTED FEVER

1923 ◽  
Vol 37 (2) ◽  
pp. 221-230 ◽  
Author(s):  
F. M. Nicholson
Keyword(s):  
Endothelial Cells ◽  
Guinea Pigs ◽  
Cytological Study ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
The Other ◽  
Rocky Mountain Spotted Fever ◽  
Nuclear Changes ◽  
Cellular Components ◽  
Blood Pigment

The Rickettsia of Rocky Mountain spotted fever were easily differentiated from mitochondria, phagocytosed blood pigment, nuclear debris, and all other known cellular constituents. Although they were lodged within the cytoplasm of endothelial cells, they were not observed to establish any definite relations with the nucleus or with other cellular components. Their number varied in contiguous cells which sustained the same degree of injury as evidenced by nuclear changes, and alterations in their mitochondria content. The mitochondria, on the other hand, showed similar modifications, characterized by a decrease in number and a rounding up into spherules, in all the endothelial cells seen in a section of an affected blood vessel. Diplobacillary forms were most abundant in the early stages of the reaction and single bacillary bodies towards its termination. Other slight differences in morphology from Wolbach's account were noted in the organisms as seen in the tissues of both ticks and guinea pigs. His study of the distribution of specific lesions with accompanying organisms in the tissues of guinea pigs was confirmed and extended.

scholarly journals STUDIES ON THE ETIOLOGY OF HEARTWATER

1926 ◽  
Vol 44 (6) ◽  
pp. 803-814 ◽  
Author(s):  
E. V. Cowdry
Keyword(s):  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
The Other ◽  
Vascular Endothelial ◽  
Rocky Mountain Spotted Fever

The Rickettsiæ of heartwater are more definitely restricted to the vascular endothelial cells of infected animals than are those of typhus or Rocky Mountain spotted fever. They likewise form more pronounced spherical colonies within the cells. Their presence does not injure the endothelial cells to a degree at all comparable with that caused by the other pathogenic Rickettsiæ. The rupture of endothelial cells and discharge of Rickettsiæ, which are apparently viable, into the circulation constitute phenomena not thus far reported in the case of typhus or Rocky Mountain spotted fever.

scholarly journals STUDIES ON TYPHUS FEVER

1931 ◽  
Vol 53 (4) ◽  
pp. 493-497 ◽  
Author(s):  
Hans Zinsser ◽  
M. Ruiz Castaneda
Keyword(s):  
Guinea Pigs ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
Active Immunization ◽  
Rocky Mountain Spotted Fever ◽  
Typhus Fever

Guinea pigs can be immunized against Mexican typhus virus by peritoneal injections of formalinized Rickettsia material, provided sufficient amounts of the organisms are used. Our results in this respect are analogous to those of Spencer and Parker with carbolized virus of Rocky Mountain spotted fever. The Rickettsia suspensions appear to possess considerable toxicity. We do not wish to be misunderstood as implying that the results in guinea pigs offer anything more than a demonstration of the principle of active immunization with killed Rickettsiae. Application to man will have to be worked out, and preliminary to this, we are now attempting to apply the methods to a limited number of monkeys.

scholarly journals IMMUNITY STUDIES OF ROCKY MOUNTAIN SPOTTED FEVER

1923 ◽  
Vol 38 (5) ◽  
pp. 605-626 ◽  
Author(s):  
Hideyo Noguchi
Keyword(s):  
Experimental Infection ◽  
Guinea Pigs ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Rocky Mountain Spotted Fever ◽  
Refrigerator Temperature ◽  
Considerable Loss ◽  
Immune Rabbit

Freshly prepared mixtures of spotted fever virus and immune rabbit serum in neutral or superneutral proportions confer complete immunity on guinea pigs. The mixtures undergo a considerable loss in immunizing power when heated to 60°C. for 20 minutes, but are still capable, if used in sufficient quantity, of conferring a degree of immunity on the vaccinated animal such that a subsequent experimental infection is rendered less severe and non-fatal. Unheated mixtures which had been preserved in the refrigerator at 4°C. for a period of 32 days still retained a certain degree of immunizing property. The virus alone, or mixed with normal rabbit serum, when allowed to die out by prolonged preservation at refrigerator temperature, or when killed either by heating at 60°C. for 20 minutes or by chemicals (chloroform, ether, xylene) does not induce immunity in guinea pigs.

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