mm mmmmi 



tissue-culture monolayers in the 



latitis virus to growth in tissue 



lititis virus from an infected hu- 



ture plaque assay for foot-and- 

 \iDV) . 



lb testis cells, which supports the 

 .!s of FMDV. 



disease vims in the electron mi- 

 ll it as a particle approximately 

 one-millionth inch) in diameter, 

 coat which protects a core of 

 I. 



:ein coat may be removed from 

 y, and that the RNA core is the 



luclease (RNase) — an enzyme 

 ssues — rapidly digests RNA, but 

 FMDV. Developed methods to 



leat resistant, but may be inacti- 

 C. for 6 hours. 



, capable of producing infection, 

 woiled FMDV. 



tiplies without clinical signs of 

 3ies of animals not known to be 



Confirmed that the separated RNA core can reproduce 

 whole FMDV when inoculated in cattle. 



Established that FMDV survives in lymph nodes and 

 blood of beef carcasses for as long as 60 days, in bone 

 marrow for more than 6 months, and in lymph nodes of 

 wet, salt-cured meat for as long as .50 days. 



Determined that FMDV persists in cattle kidneys after 

 clinical signs of disease disappear. 



Demonstrated that glycolytic metabolism (nonoxidative 

 breakdown of sugar) is more essential to FMD viral 

 reproduction than are oxidative reactions. 



Found that FMDV is inactivated by organic acids, and 

 by ethylene oxide gas, when sufficient humidity is pres- 

 ent, and that beta-propiolactone, acetylethyleneimine, 

 and ethylene oxide may be used as inactivants when 

 retention of antigenicity is desired. 



Determined that FMDV may be present in semen of 

 infected bulls and may be transmitted to cows by aili- 

 ficial insemination. 



Developed a rapid laboratory diagnostic test for African 

 swine fever, in cooperation with the East African Vet- 

 erinary Research Organization. 



Attenuated a strain of rinderpest virus, \vhich shows 

 promise as a live-virus vaccine for cattle. 



Found that rinderpest virus suspensions contain at least 

 two different particles. 



Developed a rapid serological test for diagnosis of 

 rinderpest. 



Improved procedures for differentiating the types of 

 vesicular exanthema virus. 



