Putative immunoglobulin VH genes of the goldfish, Carassius auratus, detected by heterologous cross-hybridization with a murine VH probe

By using a defined cDNA probe for the VH region of a murine phosphocholine-binding myeloma protein (S107) we have defined a family of distinct cross-hybridizing DNA sequences in genomic DNA of the goldfish. The estimated number of the goldfish putative VH family detectable by the S107 probe is about 36. By using two putative goldfish VH probes to analyze, by hybridization, the relationships among seven of the goldfish genomic clones, we have determined that the putative goldfish VH genes recognized by the S107 probe comprise at least several distinct families that are not closely related.     

An investigation into the origin of the first fraction of the canine ejaculate

Histological examination of the reproductive tract of the male dog failed to identify glandular tissue other than the prostate gland and its disseminated portion. A biochemical study of the three fractions of the ejaculate demonstrates similarities between the first and the third fractions. The composition of three ejaculates collected over 12 hours indicated that storage of prostatic secretion was a possible explanation for the biochemical differences observed. It is suggested that both the first and third fractions originate from the prostate gland.     

The importance of interleukin-8 as a neutrophil chemoattractant in the lungs of cattle with pneumonic pasteurellosis.

Interleukin-8 (IL-8), an in vitro and in vivo neutrophil chemoattractant, is expressed at high levels in the lesions observed in bovine pneumonic pasteurellosis. Because of the role of neutrophils in the pathogenesis of pneumonic pasteurellosis, we investigated the relative importance of IL-8 as a neutrophil chemoattractant in this disease. Bronchoalveolar lavage (BAL) fluid was harvested from calves experimentally infected with bovine herpesvirus-1 and challenged with Mannheimia haemolytica. Neutrophil chemotactic activity was measured in pneumonic BAL fluid samples treated with a neutralizing monoclonal antibody to ovine IL-8, and compared to the activity in samples treated with an isotype-matched control antibody. Bronchoalveolar lavage fluid was analyzed at a dilution which induced a half-maximal response, and the concentrations of antibody were optimized in a preliminary experiment. Following incubation of replicate samples of diluted pneumonic bovine BAL fluid with 70 microg/mL of IL-8-neutralizing antibody or control antibody, the neutrophil chemotactic activities of the samples were determined using an in vitro microchemotaxis assay. Overall, pretreatment of BAL fluid samples with neutralizing anti-IL-8 antibody reduced neutrophil chemotactic activity by 15% to 60%, compared to pretreatment with control antibody. This effect was highly significant (P < 0.001), and was present in 5 of 5 samples. These data indicate that IL-8 is an important neutrophil chemoattractant in calves with pneumonic pasteurellosis, but that mediators with actions redundant to those of IL-8 must also be present in the lesions.     

Simian immunodeficiency virus infections in vervet monkeys (Clorocebus aethiops) at an Australian zoo

A number of monkey species, including African green monkeys and African vervet monkeys (Chlorocebus aethiops), are frequently infected in the wild and in captivity with a Simian immunodeficiency virus strain, SIVagm, a primate lentivirus. Up to 50% of African green monkeys are estimated to be infected with SIVagm. SIV strains are very closely related to HIV-2 strains, which are a cause of AIDS in humans, predominantly in western Africa, although cases in Australia have also been reported. It is generally thought that SIV is non-pathogenic in several natural hosts, including African green monkeys. Nevertheless many SIV strains induce a profound immunodeficiency virtually identical to HIV-1 induced AIDS in humans when administered to Asian macaque species such as rhesus (Macaca mulatta) or pigtailed macaques (M nemestrina). SIV infection of Asian macaque species is frequently employed as an animal model for AIDS vaccine studies. In November 1996 a group of 10 African vervet monkeys were imported from the USA for display at Victoria's Open Range Zoo in Werribee. Two animals in this group of monkeys later developed a fatal gastroenteric illness. These diagnoses led us to initiate SIV testing of the colony.     

Lymphocyte subsets in porcine tonsillar crypt epithelium

The palatine tonsils are part of the mucosa-associated lymphoid tissue (MALT), strategically located in the oropharynx at the entrance of respiratory and gastrointestinal tracts, and are recognized portals of entry and sites of multiplication and persistence of several pathogens in pigs. As the tonsillar crypt epithelium is in close contact with external environment and the underlying lymphoid tissue, the characterization of the intra-epithelial lymphocyte subpopulations is essential for the understanding of initial steps of pathogenesis of several diseases. In this work we investigated specific lymphocyte subsets in the tonsillar crypt epithelium of 10 adult healthy pigs, using monoclonal antibodies against lymphocyte markers CD3, CD4, CD8, gammadelta T cell receptor and immunoglobulin light-chain in an avidin-biotin immunoperoxidase technique. The crypt epithelium was usually extensively infiltrated by a diverse population of T cells and by B cells. The degree of infiltration of each subset was variable among animals and within individual animals. In the T cell population CD4 cells and gammadelta TCR cells predominated over CD8 cells. These data suggest that the crypt lymphoepithelium is capable of participating in both cellular and humoral immune responses and that gammadelta T cells may play an important role in the defense of this mucosa.     

In this issue – May 2010

Flea-associated infectious agents in cats in Eastern Australia · Complications of barium-impregnated polyethylene spheres · Reproductive efficiency of Thoroughbred and Standardbred horses · GPS tracking collars to monitor horses · Correction of vesicovaginal reflux in mares · Antibodies to Lawsonia intracellularis in Australian pig herds · Mucormycosis in the platypus · Panniculitis from Mycobacterium mageritense in a Tasmanian devil     

IN THIS ISSUE – June 2010

Surveillance for West Nile virus in Australia: role of the little raven · Fertility in mares after surgical correction of rectovaginal fistula · Development of method for serial blood sampling from conscious dogs · Specificity of a commercial snake venom detection kit in dog and cat urine · Femoral component failure in canine cemented total hip replacement · Hepatic myelolipoma incarcerated in a peritoneopericardial diaphragmatic hernia in a cat · Diclofenac sodium and flunixin meglumine with antibacterial treatment of respiratory disease of calves · Lead-free petrol reduces risk of acute lead poisoning in Australian cattle