Transmission of bovine viral diarrhoea virus through the semen of acutely infected bulls under field conditions.

Epidemiological investigations implicated the semen of artificial insemination (ai) bulls as the only plausible source of infection with bovine viral diarrhoea virus (bvdv) in 10 Finnish dairy herds. The infection was traced back to two northern Finncattle bulls that had been transiently infected when their semen had been collected while they were in a gene bank herd containing persistently infected (pi) animals. The isolates of bvdv from the animals in the gene bank herd, from the semen of the two bulls and from a pi calf born in one of the herds using the semen belonged to a rare genetic type in Finland and, on the basis of the nucleotide sequences in the 5' untranslated region, were identical. Cross-contamination of batches of semen at the ai station and an external source of bvdv were ruled out for the recipient herds. It was concluded that bvdv infection can be transmitted through the semen of transiently infected bulls under field conditions.

Comparison of RT-PCR assay and virus isolation in cell cultures for the detection of bovine viral diarrhoea virus (BVDV) in field samples.

The virus isolation-immunoperoxidase test (IPX) on cell cultures and the reverse transcription-polymerase chain reaction (RT-PCR) assay were compared for the detection of bovine viral diarrhoea virus (BVDV) directly in serum samples. Material for this study consisted of 403 sera originating from cattle in 41 BVDV-infected Finnish dairy herds and one suckler cow herd. The presence of virus was demonstrated in 48 samples by both assays. In addition, two more samples were found to be positive by the RT-PCR assay. Both methods proved to be extremely sensitive, detecting pestiviruses even in high serum dilutions, and thus to be suitable for demonstrating the occurrence of persistently infected (PI) cattle. In conclusion, the RT-PCR method used had the advantage of ascertaining BVDV nucleic acid sequences in samples in which the virus had been inactivated, eg during transport or due to the presence of neutralising antibodies.

Trigeminal foraminal patterns in "skeletal" Class II and Class III adults--a radiocephalometric study.

Radiocephalometric analysis, based mainly on the foramina of the trigeminal nerve branches, was applied to three samples of adults, two representing fairly extreme profile types, the third representing "normal" dentofacial build. The aim of the study was to find out whether the analytical method could be used to differentiate between facial types. It appeared that some elements of the method had diagnostic powers, and could substitute for traditional methods. Many dimensions inspected, however, were fairly similar in all facial types, thus suggesting a general basic role of the trigeminal nerve in relation to craniofacial structure. Generally speaking, the foraminal pattern was relatively stable in "normal" faces, but more variable in deviant faces.