Molecular genetics was used to devise the first reliable diagnostic tool for differentiating morphologically indistinguishable dorsal-spined, first-stage larvae (L1's) and other stages of the nematode protostrongylid subfamily Elaphostrongylinae. A polymerase chain reaction (PCR) assay employing specifically designed primers was developed to selectively amplify DNA of the ITS-2 region of the ribosomal gene. Amplification of the entire ITS-2 region differentiated between larvae of the genera Elaphostrongylus and Parelaphostrongylus, based on the lengths of fragments produced. Three sets of primers were designed and used successfully to distinguish larvae at the species level. Although it was demonstrated that one primer set in a single PCR assay was capable of distinguishing each of the three Parelaphostrongylus spp., a second primer set would be required for confirmation in routine diagnostic use. Two of the three primer sets were capable of amplifying DNA from all six elaphostrongyline species and of identifying Elaphostrongylus alces and Parelaphostrongylus odocoilei. Although two separate fragments were produced from each Elaphostrongylus cervi and Elaphostrongylus rangiferi, it was not possible to distinguish these two parasites from each other based on the fragment size. The use of various nematodes, hosts, and fecal controls demonstrated the reliability of the primers for all developmental stages including L1's, third-stage larvae, and adult worms. These primers also have potential for identifying other lungworms as was shown by the amplification of Umingmakstrongylus pallikuukensis, the muskox protostrongylid, and Dictyocaulus sp. from white-tailed deer. Although this assay may benefit from further refinement, its present design provides researchers, wildlife managers, clinicians, and animal health regulators with a practical tool for the control, management, and study of meningeal and tissue worms and their close relatives.

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Abstract. Accurate identification of bovine Parainfluenza type 3 virus in bovine respiratory disease requires dependable, sensitive, and specific techniques for detection in affected animals. Immunohistochemical testing can be a rapid and reliable means of demonstration of virus in tissues from suspect cases; however, this procedure is dependent upon the quality of the antisera directed against the viral antigens. The production of rabbit polyclonal and murine monoclonal antibodies directed against bovine Parainfluenza type 3 virus and techniques for their use in fresh-frozen and formalin-fixed paraffin-embedded tissues in immunofluorescence and immunoperoxidase-based immunohistochemical tests are described.

Blast cells from 26 cases of acute myeloid leukaemia (AML) were examined, by single and “two‐colour” flow cytometry, for relationships between membrane CD11b (monoclonal antibody OKM1), CD11c (KB90) and CD14 (Leu‐M3). Increased expression of all three determinants was associated with myelomonocytic leukaemias, with their relative diagnostic value in discriminating monocytic (M4 and M5) from non‐monocytic (M1, M2 and M3) subtypes being CD14 > CD11c > CD11b. However, the results also indicated, because of the heterogenous expression of CD11c in particular, and to a lesser extent CD11b, that the patterns or histograms of fluorescent staining were potentially more informative than an empirical subdivision of blasts into positive and negative sub‐populations. In addition, analysis of phenotypic correlations by simultaneous two‐colour fluorescence showed that the expression of CD11b and CD11c determinants by leukaemic myeloid blasts was highly correlated, in contrast to the expression of CD14 and CD11c which were relatively independent. Consequently, CD11c + myeloid blasts almost always co‐expressed CD11b whereas CD14 + cases of AML often comprised CD14 + CD11c + and CD14 + CD11c‐ subpopulations. It is concluded from these observations that CD11c immunophenotyping is a useful supplementary investigation, particularly in CD14‐ cases of myelomonocytic leukaemia. However, it is also apparent that the presence of membrane CD11c per se is not lineage‐specific and that the level of expression is perhaps a more discriminatory factor.

Serological diagnosis of Parelaphostrongylus tenuis infection should offer many advantages over the currently used method of fecal analysis that relies on a patent infection. Toward this end, we investigated the presence of P. tenuis-specific antibodies in experimentally infected white-tailed deer (WTD) and of unique P. tenuis antigens that may be exploited for serodiagnosis. WTD infected with 6, 20 or 100-150 P. tenuis third-stage larvae (L3) had anti-parasite antibodies from as early as 21 days postinoculation (dpi) until the end of the experiment (147 dpi). Peak anti-P. tenuis enzyme-linked immunosorbent assay (ELISA) titers in individual animals ranged from 1:70 to 1:5,700. Serum from infected WTD reacted with 5 distinct P. tenuis L3 antigens (105, 45, 37, 32, and 19 kDa) as detected by the immunoblotting technique. Serum from caribou infected with Parelaphostrongylus andersoni or Elaphostrongylus rangiferi reacted with all antigens except the 37-kDa antigen of L3, indicating that it may be unique to P. tenuis and can serve as a serodiagnostic antigen. The 37-kDa antigen appears to be present in the adult P. tenuis but not adult E. rangiferi or E. cervi. The development of an ELISA utilizing the unique antigen of P. tenuis should lead to a reliable diagnostic assay for P. tenuis infection in WTD.