Characterisation of the kappa light chain of the brushtail possum (Trichosurus vulpecula)

Two full length cDNA sequences encoding the kappa light chain of the Australian marsupial, Trichosurus vulpecula, the brushtail possum, were isolated from a mesenteric lymph node cDNA library. The constant regions (Ckappa) of the two light chains were identical, but the variable (Vkappa) and joining (Jkappa) regions were different. At the amino acid level, possum Ckappa was most similar to Ckappa of an American marsupial, Monodelphis domestica (75%), with similarity to eutherian Ckappa ranging from 47 to 63%. The availability of molecular data will enable the development of immunological reagents for studying immune responses and disease in marsupials, thereby aiding conservation strategies and veterinary medicine.     

Transitional cell carcinoma of the urinary bladder in a Thoroughbred, with intra-abdominal dissemination

A 14-year-old Thoroughbred gelding with a history of acute onset of hematuria was presented for necropsy. Transitional cell carcinoma of the urinary bladder with intra-abdominal dissemination was diagnosed. Tumor masses were observed on the splenic capsule and surrounding the distal abdominal aorta. Tumor cells showed diffuse cytoplasmic reactivity for cytokeratin but were negative for epithelial membrane antigen, carcinoembryonic antigen, tumor-associated glycoprotein 72, and vimentin.     

Sequential study of lesion development in experimental haemophilus pleuropneumonia

Recently weaned pigs were infected aerogenically with Haemophilus (Actinobacillus) pleuropneumoniae, serotype 5. At three, six, 12, and 18 hours and one, two, four and seven days after exposure to haemophili a pair of animals were killed and necropsied. Pulmonary oedema with multifocal petechial haemorrhages and a diffuse neutrophilic bronchiolitis and alveolitis were observed at three and six hours after infection. Focal areas of coagulative necrosis developed in areas of intense suppuration at 12 and 18 hours after infection. At one and two days after infection, necrotic areas were surrounded by dense bands of degenerating leucocytes and contained unidentifiable round and elongated cells characteristic of this disease. In subacute lesions a thick layer of granulation tissue formed around the outer margin of developing abscesses. Most of the round and elongated cells in alveolar exudates could not be identified by enzyme histochemistry or electron microscopic examination. Neutrophils in various stages of degeneration and deterioration provided strong evidence that some of the cells were of this type. These findings suggest that neutrophils may play an early and significant role in development of lesions.     

Absorption of cysticerci in cattle after treatment of taenia saginata cysticercosis with praziquantel

Two groups of calves aged 10 to 15 weeks were orally infected with either 6000 or 30,000 Taenia saginata eggs. Three to four months later they were treated with praziquantel, three doses of 50 mg kg-1 on three consecutive days. All the cysticerci were killed by the drug and most were absorbed by between six and nine months after treatment. From then on there was little further absorption and residual calcified cysts were still found in the carcases up to 24 months after drug treatment. These residual calcified cysts were particularly common in the heart muscles and would probably have been detected at meat inspection.     

Quantitative study of pulmonary endocrine cells in fetal, postnatal and adult sheep

Using light microscopic immunohistochemistry, neuron-specific enolase (NSE)-positive endocrine cells were quantitatively analyzed in the sheep lung during different stages of development from the canalicular stages to adulthood. In all stages, NSE-positive endocrine cells were usually located in the bronchi and bronchioles as solitary cells, although a few NSE-positive cell clusters, the so-called neuroepithelial bodies, were found in some places. The number of NSE-positive endocrine cells decreased with advanced stages of gestation. In the late alveolar stage, the number of NSE-positive endocrine cells reached its bottom during the fetal period. There was a gradual upturn after birth. The overall pattern of growth and differentiation of the endocrine cells is most likely species-related and depends on the state of airway development; the number of the endocrine cells of almost all animals, excluding the sheep, in relation to the size of the lung reaches a peak in the late fetal and early neonatal periods and decreases shortly thereafter. NSE-positive endocrine cells were also predominantly located in the large airways during the early stage of development (canalicular stage), and were found more frequently in the small peripheral airways towards the term. These results show the number of NSE-positive endocrine cells in the sheep to be different from that seen in other species.     

Funisitis associated with leptospiral abortion in an equine placenta

Funisitis, inflammation of the umbilical cord, is well recognized in human placentas. This report describes a case of funisitis associated with leptospiral infection in the placenta of a Thoroughbred foal born prematurely. The umbilical cord had diffuse superficial yellow discoloration along its entire length. Microscopic evaluation showed an exudate of neutrophils admixed with fibrin on the surface. Warthin-Starry staining showed spirochetes in the Wharton's jelly of the umbilical cord. A locally extensive, severe placentitis not involving the star and allantoic cystic hyperplasia were the other lesions observed in the allantochorion. Leptospira funisitis is similar to the funisitis of congenital syphilis in humans, although there are some major microscopic differences. In Leptospira funisitis, lesions were limited to the cord surface, whereas in lesions in human umbilical cords with Treponema pallidum infection, the changes are observed mostly around the vessels and in the Wharton's jelly.     

Studies on helminthosis at the centre for tropical veterinary medicine (CTVM)

Summary The research work relating to helminths, which has been conducted within the Helminthology Section of the CTVM, often in collaboration with colleagues from the tropics is reviewed and placed into a historical perspective. The research has, in the main, concentrated on the trematodesFasciola hepatica andFasciola gigantica and the cestodesTaenia saginata andTaenia solium, but work on other parasites including gastro-intestinal nematodes is also considered. All of these parasites are of obvious veterinary/economic importance particularly in the tropics and subtropics. While the zoonotic importance ofT. saginata andT. solium has been recognised for many years, it is only more recently that the zoonotic impact ofFasciola spp. has been generally acknowledged.

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Estudios Sobre Enfermedades Causadas Por Helmintos En El CTVM

Resumen El artículo revisa y sitúa en una perspectiva histórica la investigación sobre helmintos realizada en la sección de helmintología del CTVM, a menudo en colaboración con otros investigadores de países tropicales. La investigación se ha centrado principalmente en los trematodosFasciola hepatica y Fasciola gigantica y en los cestodosTaenia saginata y Taenia solium, aunque en el artículo se incluye también el trabajo realizado con nematodos gastrointestinales y otros parásitos. Todos los parásitos mencionados tienen una importancia obvia desde el punto de vista veterinario y económico, particularmente en los trópicos y subtrópicos. Mientras que la importancia deT. saginata yT. solium como zoonosis ha sido siempre reconocida, el posible carácter zoonótico deFasciola spp. ha sido descubierto muy recientemente.

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Etudes Sur Les Helminthiases A CTVM

Résumé Le travail de recherche portant sur les helminthes, qui a été mené dans le groupe Helminthologie à CTVM, souvent en collaboration avec des collègues des pays tropicaux, est passé en revue et mis dans une perspective historique. La recherche a principalement porté sur les trematodesFasciola hepatica etFasciola gigantica et sur les cestodesTaenia saginata etTaenia solium, cependant d'autres travaux ont également porté sur d'autres parasites et sur des nématodes gastro-intestinaux.Tous ces parasites sont d'une importance économique/vétérinaire évidente et ceci particulièrement dans les pays tropicaux et sub-tropicaux. Tandis que l'importance deT. saginata etT. solium, sur la zoonose, a toujours été reconnue, ce n'est que récemment que l'impact deFasciola spp sur la zoonose a été repertorié.

     

Taenia saginata derived synthetic peptides with potential for the diagnosis of bovine cysticercosis

Immunity in Taeniids is predominantly antibody mediated and thus many serological immuno-determinants will have potential in both protection and diagnosis. The antigenicity of six peptides derived from four potentially protective molecules cloned from a Taenia saginata oncospheres cDNA library have been evaluated as targets for the specific diagnosis of bovine cysticercosis. The six peptides consist of: two peptides (HP6-2 and HP6-3) derived from the sequence of the 18 kDa surface/secreted oncospheral adhesion antigen identified by McAb-HP6, two peptides (Ts45W-1 and Ts45W-5) derived from the sequence of the T. saginata homologue of the T. ovis 45W protective gene family, one peptide (TS45S-10) derived from a T. saginata sequence with significant similarity to the T. ovis 45S protective antigen, and one peptide (TEG-1) derived from the sequence of the T. saginata homologue of Echinococcus spp. main surface protein. Longitudinal studies indicate that T. saginata infected cattle respond to all six peptides by 3-4 weeks post-infection and that the antibody levels remain high for at least 12 weeks post-infection. As protection against Taeniid parasites is predominantly antibody mediated, some of these six peptides may be of value as immuno-prophylactic tools and hence also in assays to determine resistance to infection with the parasite. For diagnosis, on the other hand, only three peptides (HP6-2, TEG-1 and Ts45S-10) performed with the necessary sensitivity and specificity to determine exposure to infection with T. saginata, and now merit an exhaustive evaluation prior to employment as routine diagnostic tools.     

Heligmosomoides polygyrus and Trypanosoma congolense infections in mice: effect of immunisation by abbreviated larval infection.

Concurrent African trypanosome and gastrointestinal helminth infections are prevalent in sub-humid savannah where they are endemic. However, acquired resistance in animals varies with their responder status and exposure. As a guide to study in the definitive hosts, the effects of Trypanosoma congolense infection on the development and maintenance of homologous Heligmosomoides polygyrus resistance were investigated in outbred TO mice. These mice were immunised by abbreviation of larval infection. Immune or naive mice were either infected with 500 infective larvae (L3) of H. polygyrus and/or 10(4) bloodstream forms of T. congolense or were not infected. The outcome of infection was monitored by routine parasitological and immunological techniques for 30 days after the day of the T. congolense infection. Significantly more immune mice concurrently infected with both parasites survived than did immune mice in which H. polygyrus was superimposed on a 10-day-old T. congolense infection. Although all the mice in this latter group died before the end of the experiment, larval immunisation prolonged their survival, relative to similarly treated naive mice. The antibody titres to H. polygyrus in the sera of immune mice challenged with H. polygyrus alone were significantly higher than those of immune mice concurrently infected with both parasites but the levels of protection obtained were comparable. It is concluded that T. congolense may not completely block the strong acquired resistance induced by abbreviated H. polygyrus larval infection in TO mice but is capable of interfering with protective responses, especially if the trypanosome infection occurs prior to H. polygyrus challenge infection.