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Four lamb rotaviruses were characterised serologically by reactions with monoclonal antibodies and genomically by hybridisation assays and sequencing. Each was found to be distinct. Three viruses belonged to the bovine genogroup and were of subgroup I. These viruses possessed serotypes G3, G6, and G10. Their corresponding P types were P1, P11, and P14 respectively. The only previous isolation of a rotavirus with VP4 of type P14 was also from lambs. The fourth isolate was G9P8, which is the first record of a G9 rotavirus from a species other than man.

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A simple liquid-hybridization assay was developed which allows assessment of the degree of hybridization between the two serotype-determining genes of the bovine rotavirus strain UK and the homologous genes of the isolate under test. 32P-labelled transcription probes were produced from cloned complementary DNA (cDNA) copies of UK gene segments 4 and 8 and hybridized to double stranded RNA (dsRNA) extracted from rotavirus-positive field samples. Subsequent treatment with ribonuclease A (RNase A), separation of the RNase A-resistant hybrid fragments by polyacrylamide gel electrophoresis (PAGE) and autoradiography yielded a specific, reproducible banding pattern for each isolate. A total of 74 field samples was tested by both the hybridization assay and by an enzyme-linked immunosorbent assay (ELISA) using serotype-specific monoclonal antibodies (Mabs). The results obtained were in excellent agreement and confirmed that serotype G6 rotaviruses predominated. Hybridization of these G6 viruses with the gene 4 probe suggested that viruses with Vp4s related to that of UK rotavirus are also common. The hybridization assay was more sensitive than the ELISA.

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A series of five reassortant viruses each containing the VP4 gene of a distinct bovine rotavirus and the VP7 gene of human rotavirus strain ST3 was prepared, and antisera to these were produced in rabbits. In neutralization tests, these antisera allowed the differentiation of the five original strains (from three different VP7 or G serotypes) into three or possibly four VP4 or P serotypes. All of a further seven bovine rotavirus strains adapted to cell culture were successfully typed by these antisera. There was a degree of cross-reaction between antiserum to the fourth bovine rotavirus P serotype and the predominant human rotavirus serotype. However, antisera raised in guinea-pigs to recombinant VP4 from this serotype showed the bovine serotype to be distinct. There was no significant serological relationship between these four bovine rotavirus P serotypes and previously described P serotypes from rotaviruses isolated from man and non-bovine animals. The predominant bovine rotavirus VP7 serotypes G6 and G10 tended to have distinct P serotypes also.

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Ten cultivable equine rotavirus isolates, two of North American, six of British, and two of Irish origin, were compared with standard rotavirus strains and with each other by cross neutralization, neutralization with a panel of monoclonal antibodies (MAbs), hybridization to a simian rotavirus (SA-11) VP7 gene probe, and reaction with rotavirus subgrouping and serotyping MAbs in enzyme-linked immunosorbent assays. Six isolates, two of which had previously been serotyped as G3 by other workers, were found to be serotype G3; one was confirmed to be G5, and three were not related to serotypes G1 to G10. The serotype G3 strains were divisible into two subtypes, G3A and G3B, on the basis of cross neutralization. This division was also apparent in reactions with neutralizing VP7-specific MAbs and in the liquid hybridization assay. Two of the isolates were not bound by either subgroup MAb, six were bound by both subgroup I and II MAbs, and two were bound by only the subgroup I MAb. The assays used in this characterization provide a range of epidemiological information for use in future field investigations.

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Foal fecal group A rotavirus strains were characterized by electropherotype, serotype, and subgroup and shown to be distinctly different from rotaviruses of other mammals. Of 86 strains that were electropherotyped, 98% had similar profiles, with gene segments 3 and 4 close together and segments 7, 8, and 9 widely spaced. Of 70 strains that had sufficient detectable VP7 antigen to be serotyped by enzyme-linked immunosorbent assays (ELISAs), 63% were serotype G3 (39% were subtype G3A and 24% were subtype G3B), 4% were serotype G13, and 33% were untypeable. Serotypes G1, G2, G4, G5, G6, G9, G10, and G14 were not detected, although G5 and G14 strains have been identified among cultivable equine strains. Of 50 strains that had sufficient detectable VP6 antigen to be subgrouped by ELISAs, only 12% were able to be assigned to either subgroup I or II, with the remaining 88% belonging to neither subgroup.

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Gnotobiotic or specific-pathogen-free animals with no previous exposure to rotavirus were vaccinated with strain UK, serotype G6. The highest serological response was to homologous virus; significant but lower responses occurred to viruses with either VP4 or VP7 related to that of vaccine virus; responses to other viruses were of low titer or infrequent. Adult cows vaccinated with UK virus produced increased titers of antibody to all rotavirus serotypes. The increases in titer to homologous virus and to other natural and reassortant viruses sharing VP7 with the vaccine virus were significantly higher than those to all other viruses. These results suggest the presence of common epitopes which are not well recognized in primary infections.

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Equine rotavirus FI23 was shown to be prototypic of a novel G serotype, provisionally G14, by cross-neutralization and VP7 sequence determination. Although distinct, there are as few as six differing amino acid residues (92, 94, 96, 146, 147, and 221) in the VP7 antigenic regions of FI23 and G3 rotaviruses.

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The sensitivity of a rotavirus serotyping enzyme-linked immunosorbent assay (ELISA) was improved by the addition of 0.5 mM CaCl2 to the washing buffer and reagent diluent. Twenty-nine of 63 (46%) previously untyped bovine and equine faecal rotavirus samples were serotyped in the modified assay. A differential response to Ca2+ ions was noted for different G-serotypes suggesting that serotyping assays performed without the inclusion of CaCl2 in the assay buffers may produce biased results.

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A group A rotavirus designated L338 was isolated from the faeces of a diarrhoeic foal and was compared to 11 standard G serotype strains of group A rotaviruses by cross-neutralization. It was clearly distinct from serotypes G1 to G11 and thus representative of a novel rotavirus G serotype tentatively designated G13. The nucleic acid sequence of the virion protein 7 (VP7) coding region was determined and the deduced amino acid sequence compared to published sequences. Within VP7 regions A and B, L338 was clearly distinct from serotypes G1 to G12 (excluding G7 which has not been sequenced), but region C was very similar to those of G3 and G8. This further questions the significance of region C in determining serotype specificity of at least three distinct rotavirus G serotypes.

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The homotypic and heterotypic antibody response to rotavirus was determined in three pony mares and their foals. The normal concentrations of anti-rotavirus antibodies in mares' milk and mares' and foals' serum over the first 10 weeks post-partum were measured using IgA, IgG and rotavirus serotype-specific enzyme linked immunosorbent assays. Experimental infection of the foals with serotype 3 equine rotavirus produced a rapid, serotype-specific response which peaked 10 days after infection and a slower heterotypic response which peaked 32 days later. In contrast, vaccination of the mares with an inactivated, adjuvanted serotype 6 bovine rotavirus produced a heterotypic response similar to that of the homotypic response in both serum and milk, although the predominant response in serum was IgG, while in milk it was IgA. These results suggest that non serotype-restricted passive protection of foals against rotavirus may be achieved by parenteral vaccination of mares.

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The podiatrist specializing in biomechanical therapy must begin with a solid foundation of standardized definitions in order to discuss theories of mechanical foot treatment as they have been presented and developed over the past century. Equally important, is the building of a working knowledge and familiarity with the wide variety of available materials and their diverse properties. In addition, in order to arrive at an accurate biomechanical diagnosis, the clinician must evaluate the patient from static, dynamic, and radiographic perspectives. One must also keep current in regard to various technological advances in casting and fabrication of orthotic devices, as well as in new developments in biomechanical theory and associated therapy. It also must be kept in mind that functional foot orthoses are not 100 per cent efficient, therefore, their shape, fabrication, and composition should all be devised and prescribed with specific goals for total body mechanics.

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The costs of research in human subjects are compared to those in primate animals and in other animal models on the basis of data available from a U.S. institution. The cost of experimentation in a chimpanzee is 3.59% of the per diem cost of clinical research in man. The cost for the dog is 37.1% of that of the chimpanzee, and the mouse costs 2.02% of the cost of the dog.

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Implementation of the present regulations of animal experimentation compared to use of human subjects in a setting of a large medical school including the impact on administrative systems involved in the compliance and monitoring process as well as cost of implementation.

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