A 1.3-year-old Great Dane dog had a chronic progressive neurologic disease clinically expressed as a distal symmetrical polyneuropathy characterized by weakness and bilateral atrophy of bulbar and distal appendicular musculature. Qualitative and quantitative studies showed neurogenic atrophy of muscles below the elbow and stifle. There was Wallerian-type degeneration, Schwann cell proliferation...

The structure of hepatitis B virus (HBV) has been characterized in great detail (Tiollais & Buendia, 1991). HBV belongs to a group of hepatotropic DNA viruses (hepadnaviruses) that includes the hepatitis viruses of the woodchuck (Summers et al., 1978), ground squirrel (Marion et al., 1980), Pekin duck (Mason et al., 1980) and heron (Sprengel et al., 1988). HBV is a smaII virus, about 42 nm in d...

The hepatoblastoma cell line Hep G2 was transfected with a plasmid carrying the gene that confers resistance to G418 and four 5'-3' tandem copies of the hepatitis B virus (HBV) genome positioned such that two dimers of the genomic DNA are 3'-3' with respect to one another. Cells of one clone that grew in the presence of G418 produce high levels of hepatitis B e antigen and of hepatitis B surfac...

We envision that the next generation of knowledge-based CAD systems will be characterized by four features: they will be based on cognitive accounts of design, and they will support collaborative design, conceptual design, and creative design. In this paper, we first analyze these four dimensions of CAD. We then report on a study in the design, development and deployment of a knowledge-based CA...

The infectious particles of hepatitis B virus are called Dane particles and consist of viral nucleic acid encapsulated within a core particle that is enveloped by virus-coded surface proteins. The major S protein constitutes a significant fraction of these surface proteins. In addition, there are two other related proteins (large S and middle S), but their role in envelope formation has not yet...