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An experiment was set up to assess the influence of some parameters on the production of ascites and monoclonal antibodies against circulating excretory-secretory antigens of Taenia saginata cysticerci in mice. The following parameters were examined: time lapse between priming and the inoculation of hybridoma cells, age and body weight of the mice at the time of inoculation, number of cells injected IP, and the resulting antibody titers of the ascites. In this experiment the method used to prime the mice was the only factor having an influence on the amount of ascites produced. Injection of a higher number of hybridoma cells (2-4 x 10(6) cells) coincided with higher antibody titers and resulted in an earlier ascites production. The antibody titer of the ascites was increasing with time.

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A series of monoclonal antibodies (MoAb) produced against excretory and secretory products from 10- and 20-week-old Taenia saginata cysticerci were tested for their ability to detect circulating antigen in a double antibody sandwich enzyme-linked immunosorbent assay (ELISA). Two MoAb, 12G5 and 2H8, proved to be highly reactive with the tegument of viable T. saginata cysticerci and recognized antigenic components of 65, 87 and 100 kDa in immunoblotting. The detection limit of the assay using 12G5 as trapping antibody and 2H8 as a biotinylated indicator antibody was 0.1 ng protein per ml. Although the sensitivity of the test varied from one animal to another, the minimum number of living cysticerci, which could be detected by the ELISA, was 88. Animals harbouring only dead cysticerci gave similar reactions as non-infected control animals. Cross-reactions were only observed with taeniid parasites. The test was able to detect circulating antigen also in sheep and pigs, respectively infected with T. ovis and T. solium and in the serum samples of confirmed cases of human T. solium cysticercosis.

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The prophylactic activity of a subcutaneously implanted slow release device, containing homidium bromide, was assessed in rabbits, challenged with different stocks of T. congolense, and compared with the classical treatment of 1 mg homidium bromide/kg b.w. intramuscularly. The prophylactic activity of the intramuscular injection was less than a month, while the slow release device protected the rabbits against seven challenges with T. congolense during a period of more than 300 days.

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DNR can be targeted to the liver by linking to galactosylated human serum albumin (AG). The linkage is stable in the blood stream and allows the release of active DNR after endocytosis of the conjugate by the target cells. Receptors for AG are present at the cell membrane of hepatocytes, primary human hepatoma cells and lung metastases. After i.v. administration of AG-DNR more than 70% of the drug is taken up by the liver and in rats 50% of DNR is eliminated in the bile after 16 h. Nude mice bearing human hepatoblastoma cells implanted s.c. were treated twice a week with a dose equivalent to 6.6 mg/kg of DNR either for the free drug or the conjugate AG-DNR. After 7 injections, tumor growth is inhibited in both case, however, the conjugate seems more active and is at least twice less toxic in terms of LD50. A phase I clinical trial of AG-DNR on 11 patients bearing hepatocarcinoma revealed that despite a transitory hyperthermia (37-38 degrees C) during the first day of the 4 day-perfusion, and modifications of hepatic enzymes in 3 cirrhotic patients, no hematologic and cardiac toxicity could be detected. A subjective response has been obtained in half of the patients with a decrease of plasmatic alpha-foetoprotein levels by more than 50% in 4 patients and one complete remission of more than 23 months with disparition of pulmonary metastases.

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Vinblastine tryptophan ester (VTrpE) is a new vinca alkaloid derivative that achieves antitumor activity in a large variety of animal models. In this phase I study the drug was given as an i.v. injection over 5 min, once a week or once every 2 weeks. Twenty patients with advanced cancer were entered in this trial. The doses ranged from 2.5 mg/m2 to 35 mg/m2. Myelosuppression is the dose-limiting toxicity, with the risk of leukopenia being more serious than that of thrombocytopenia, but the myelosuppression is always reversible. Neurotoxicity, well documented when other vinca alkaloid derivatives are used, is insignificant. Two cases of disease stabilization have been observed in patients with non-small cell lung cancer. For VTrpE, a dose schedule of 30 mg/m2 per week may be recommended for phase II studies in non-small cell lung cancer.

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The sensitivity and specificity of enzyme linked immunosorbent assay (ELISA) for the diagnosis of Taenia saginata cysticercosis was studied among laboratory reared experimentally infected calves and conventionally raised naturally infected cattle by using a T crassiceps metacestode antigen. The intensity of the metacestode burden in experimentally infected animals had a direct effect on the first appreciable rise in the spectrophotometric extinction values and also on the progressive elevation of these values during the later stages of infection. The animals harbouring less than 100 metacestodes were the most difficult to detect by ELISA. Serum from sheep infected with Cysticercus tenuicollis showed cross-reaction. Among the naturally infected cattle the sensitivity of ELISA was poor; only 37.5 per cent of the 24 proven cases could be diagnosed. One of the nine cattle harbouring natural infection of Fasciola hepatica showed cross-reaction. Of the 69 animals 4.3 per cent showed false positive reactions.

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In an attempt to prove the specificity of the crude Taenia saginata antigen for the immunodiagnosis of bovine cysticercosis, a major and highly immunogenic fraction (F10), responsible for the formation of the typical "long band" reaction in immunoelectrophoresis, has been isolated from T. saginata proglottides by immunoaffinity chromatography. The immunoabsorbent was prepared by coupling a specifically raised hyperimmune serum (HIS) anti-F10 to Sepharose 4B. The purity of the isolated F10 was demonstrated by immunoprecipitation reactions. The HIS anti-F10, however, cross-reacted with several larval and adult Taenia spp. Consequently, F10 showed cross-reactions with the sera of animals infected with hydatid cysts or larval T. hydatigena. F10 also reacted with HIS anti-F5 (Echinococcus granulosus) but was shown to be non-identical with the well known F5 of E. granulosus. These data prove that F10 of T. saginata was not species-specific but showed a group specificity for the taeniid family - a situation analogous to F5 of E. granulosus.

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Three chemical immunosuppressive agents, viz. dexamethasone, methotrexate and cyclophosphamide, were administered to guinea-pigs two days prior to their infection with Dictyocaulus viviparus infective larvae and onward. The cell mediated immunity of these guinea-pigs was subdued under the influence of these immunosuppressive agents as evidenced by macrophage migration inhibition test but this could not prevent or postpone the rejection of majority of the worm population of guinea-pigs on day 15 post-infection. Methotrexate exerted, besides its cell mediated immunosuppressive action on the host, some inhibitory influence on the general biotic potentialities of the developing worms so that, on day eight post-infection, a reduced number of stunted worms was recovered.

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Flubendazole 5%, a parafluor analog of benzimidazole derivative, mebendazole, was found efficient in eliminating Trichuris trichiura infection of baboons when administered orally at a dose rate of 27 to 50 mg of the active ingredient per kg body weight twice daily for five days. The drug was found safe, without toxic effects and its palatability was excellent.

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Effective chemotherapy by Mebendazole of Baylisascaris transfuga infection of five polar bears is reported and a control measure programme directed towards limiting the infection under the prevailing condition is discussed.

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Lungworm infection of Canada lynx, Felis (Lynx) canadensis, presumably due to Troglostrongylus wilsoni (Nematoda: Metastrongylidae), was successfully cured with the use of Mebendazole.

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