[Detection of PI-3 viruses, BVD-MD viruses and parvoviruses in bovine fetuses after experimental intrauterine infections]. / Detekce viru PI-3, BVD-MD a parvoviru, persistujicích v bovinních fétech po experimentální intrauterinní infekci.

Growing organ cultures prepared from foetuses experimentally infected in utero by the viruses PI-3 and BVD-MD or bovine parvovirus proved to be suitable in tests with the re-isolation of these viruses 7, 14, 21, 35, 42 and 70 days after infection. The attempts at demonstrating them by the traditional method of the inoculation of the primary cell culture of foetal kidneys were successful only at the re-isolation of the PI-3 virus seven days after infection. The PI-3 virus without cytopathic effect was demonstrated in the primary cell culture prepared from the spleen, lungs, kidneys and testes of foetuses delivered seven days from infection. The cytopathic effect manifested itself after cell transplantation in the first passage when further multiplication of the virus occurred.

[Multiplication of the IBR, PI-3 and BVD-MD viruses in cell and organ cultures of bovine fetuses after experimental intrauterine infections]. / Multiplikace viru IBR, PI-3 a BVD-MD v bunecných a orgánových kulturách pripravených z hovezích fétu po experimentální intrauterinní infekci.

The intrauterine infection of four- to nine-month-old bovine foetuses with the PI-3, BVD-MD viruses, performed 7 to 72 days prior to their delivery, did not exert any significant influence upon the susceptibility of primary cell cultures from foetal organs and tissues to further viral infection in vitro. The BVD-MD and IBR viruses multiplied in the primary cell cultures from the organs of a foetus infected with the PI-3 virus seven days before delivery even in the presence of endogenous PI-3 virus. Persisting infection with the PI-3 virus also failed to influence the susceptibility of foetal organ cultures to infection with the IBR and PI-3 viruses in vitro. The IBR virus and endogenous PI-3 virus multiplied simultaneously to high titres in the organ cultures of thymus and lungs whereas in the organ cultures of kidneys, spleen and testes the multiplication of endogenous PI-3 virus was suppressed.

[Mucosal disease virus as a cause of enzootic abortion in cattle in Czechoslovakia]. / Virus sliznicní choroby jako prícina enzootických abortu v chovech skotu v CSSR.

Bovine viral diarrhoea -- mucosal disease (BVD-MD) virus was demonstrated on some farms as the causal agent of enzootic abortions in cattle. On the whole, five non-cytopathogenic strains of the BVD-MD virus were isolated from the organs of aborted foetuses of different age and prematurely born calves. The strains were identified by the direct immunofluorescence method. The same method was also used in detecting the virus antigen in the organs and tissues of colostrum deprived prematurely born calves and also calves born at term. The involvement of the BVD-MD virus in the abortions was demonstrated indirectly by detecting virus-neutralizing antibodies in the serum of heifers and cows, in the pre-colostral sera of newly born calves, and in the body fluids of aborted foetuses. The discussion deals with the importance of the BVD-MD virus as a cause of enzootic abortions, foetal malformations and early postnatal mortality of calves.