[Evaluation of the new doctoral degree program at the Faculty of Medicine in Oslo 1993-98].

Background: In 1993, the doctoral degree programme in the Faculty of Medicine of the University of Oslo was substantially revised to include coursework and supervision of thesis work. PhD students were expected to complete their work towards the doctorate in three years, and funding was only provided for this period.

Material And Methods: In spring 1999, all doctoral candidates, their supervisors and members of the adjudicating committees were invited to reply to a questionnaire with the purpose of evaluating the results of the new programme over the 1993-99 period.

Equine herpesviruses 1 and 4: amplification and differentiation by polymerase chain reaction.

Equine herpesvirus 1 and 4 (EHV-1 and EHV-4) are important pathogens responsible for considerable economic losses in the horse industry. Differentiation between these 2 viruses using conventional serological methods with polyclonal antisera has been difficult. Biological differences have, however, been recognised for a long time.

Genomic variability among globally distributed isolates of equine arteritis virus.

Equine arteritis virus (EAV), a non-arthropod borne togavirus, has been shown to have a global distribution. To date, no major antigenic variation has been demonstrated between EAV isolates from different geographic origins. In this study, the genomic RNA of EAV isolates obtained from horses of different breeds in various countries around the world was oligonucleotide fingerprinted.

Comparison of herpesviruses isolated from reindeer, goats, and cattle by restriction endonuclease analysis.

A genomic comparison of bovine herpesvirus 1 (BHV-1), caprine herpesvirus (CHV-2) and reindeer herpesvirus (RHV), was performed using 5 restriction endonucleases. Cross neutralization of these three herpesviruses showed that BHV-1 and CHV-2 had a relatively low degree of cross reaction with heterologous viruses. RHV showed a higher degree of such cross reactivity.

Inoculation of infectious pancreatic necrosis virus serotype Sp did not cause pancreas disease in Atlantic salmon (Salmo salar L.).

Atlantic salmon were selected from a fish farm with no previous record of pancreas disease (PD) or infectious pancreatic necrosis virus (IPNV) infection. Groups of fish were inoculated with either IPNV (strain Sp) from cell culture, organ material from fish with PD or control material as phosphate-buffered saline (PBS). Virological, histological and immunohistochemical examinations were carried out throughout the experiment.

Identification of a double-stranded RNA virus by using polymerase chain reaction and magnetic separation of the synthesized DNA segments.

A double-nested polymerase chain reaction assay (PCR), followed by magnetic separation of the PCR-synthesized DNA segments, was developed to detect a double-stranded RNA virus, infectious pancreatic necrosis virus from salmonid fish. Viral RNA was extracted from cell cultures and used for cDNA synthesis. The cDNA produced was used as a template in a double PCR.

Detection of infectious pancreatic necrosis virus (IPNV) RNA by hybridization with an oligonucleotide DNA probe.

Marine farming of Atlantic salmon (Salmo salar) is growing rapidly in Norway, and fish diseases have now become one of the biggest obstacles for this new industry. Infectious pancreatic necrosis virus (IPNV) is commonly found in fish from Norwegian sea farms. Diagnosis of IPNV infection is, at present, mainly based on virus isolation in cell cultures and identification by neutralization tests (NT).

Global survey of serological evidence of caprine arthritis-encephalitis virus infection.

Using caprine arthritis-encephalitis virus antigen in the agar gel immunodiffusion test, 3729 serum samples from goats in over 112 locations around the world were tested for precipitating antibodies. Over 90 per cent of the 1265 positive samples came from Canada, France, Norway, Switzerland and the USA, all of which had 65 per cent reactors or greater. Fiji, Great Britain, Kenya, Mexico, New Zealand and Peru had fewer than 10 per cent positive samples; the majority of these could be traced to importations of goats from countries where there was a high occurrence of precipitating antibody.

Experimental maedi virus infection in sheep: cellular and humoral immune response during three years following intranasal inoculation.

A long-term experiment in sheep inoculated intranasally with 2 strains of Norwegian maedi virus was carried out in 2 groups of Norwegian Dala sheep (7 sheep/group). Virus-specific cellular immune response was assayed in the lymphocyte transformation test sequentially during 3 years after sheep were inoculated in group 1 and 4 times in the 3rd year in group 2. Humoral immune response was assayed by immunodiffusion, complement-fixation, and neutralization tests on sequential serum samples collected from the 2 groups.

Experimental maedi virus infection in sheep: early cellular and humoral immune response following parenteral inoculation.

The early immune response (19 weeks) in sheep inoculated parenterally with maedi virus was studied, using the lymphocyte transformation test, immunodiffusion test, complement-fixation test, and neutralization test. Cellular immune responses were detected between 3 and 7 weeks after the sheep were inoculated. Antibodies were detected by immunodiffusion test in 3 of 5 animals in weeks 7 to 11 and by complement-fixation test in weeks 15 to 19.

Border disease in Norway. Serological examination of affected sheep flocks.

Serological examination of 4 Border disease affected flocks of sheep using the neutralization test showed antibody prevalences between 14 and 96 %. Prevalence in yearlings in 3 of the 4 flocks was 37 , it increased with age to 72 % in 5-year-old sheep. Possible reason for low prevalence (2 %) in yearlings in one of the flocks is discussed.