Cloning and sequencing of a cDNA encoding the bovine FcR gamma chain

Phagocytic cells of the immune system express specific receptors for the Fc region of immunoglobulins (FcRs). In humans, most FcRs for IgG (FcgammaR), IgA (FcalphaR) and IgE (FcvarepsilonR) consist of an immunoglobulin (Ig) -binding subunit associated with a specialized signaling molecule, the FcR gamma chain. The FcR gamma chain is crucial for the transmission of intracellular signals following receptor ligation. In cattle, however, although four distinct complimentary DNAs (cDNAs) encoding IgG-binding subunits have been described (corresponding to bovine FcgammaRI, FcgammaRII, FcgammaRIII, and Fcgamma2R), virtually, nothing is known about signal transduction via bovine FcRs. Therefore, in this study, a cDNA encoding the bovine FcR gamma chain was cloned. The cDNA is 258 base pairs long and encodes a protein of 85 amino-acids. The mature protein shows high homology with the FcR gamma chains from several other species. Interestingly, the cytoplasmic domain of the bovine FcR gamma chain is one amino-acid shorter than those previously described. Cloning of a cDNA encoding, the bovine FcR gamma chain will allow for a better understanding of signal transduction processes triggered by bovine FcRs.     

A comparison of the development and survival of the dung beetle, Onthophagus taurus (Schreb.) when fed on the faeces of cattle treated with pour-on formulations of eprinomectin or moxidectin

Faeces voided by 1-year old cattle at 3-70 days after treatment with a pour-on formulation of moxidectin had no detectable effects on development or survival of the common dung beetle Onthophagus taurus. In contrast, faeces voided by cattle treated with a pour-on formulation of eprinomectin were associated with high juvenile mortality during the first 1-2 weeks after treatment. Increased mortality also occurred among newly emerged beetles fed on faeces collected 3 days after eprinomectin treatment and there was evidence of suppressed brood production among those that survived. This effect was still apparent even after insects fed for a further 10 days on the faeces of untreated cattle. A model simulating the effects of drug residues on dung beetle populations suggests that in the absence of immigration a single treatment of eprinomectin is capable of reducing beetle activity in the next generation by 25-35%. Effects are likely to be greatest when treatment coincides with emergence of a new generation of beetles.     

Effect of pancreatectomy on plasma activities of amylase, isoamylase, lipase and trypsin-like immunoreactivity in dogs.

The contribution of the pancreas to the plasma activities of amylase, isoamylase, lipase and the concentration of trypsin-like immunoreactivity (TLI) in the dog was examined by measuring the activities of these enzymes before and after total pancreatectomy. Pancreatectomy was followed by a decrease in the concentration of TLI (from 6.2 +/- 0.3 micrograms litre-1 to 1.2 +/- 0.3 micrograms litre-1; P less than 0.001) and activity of isoamylase peak 4 (from 1257 +/- 105 iu litre-1 to 894 +/- 171 iu litre-1; P less than 0.05). Though significantly reduced, the activities of peak 4 isoamylase were still within the normal range for control dogs. Pancreatectomy did not significantly alter the activities of amylase, lipase or isoamylase peaks 1, 2 and 3. These findings provide strong evidence that the pancreas is not the sole source of circulating amylase, isoamylase and lipase activities. In contrast the marked reductions in TLI to values close to the limits of assay sensitivity suggest that TLI is derived from the pancreas alone. The results indicate that assay of circulating TLI provides a more sensitive and specific indicator of pancreatic exocrine mass than plasma amylase, lipase or isoamylase activities.     

The immunological approach to pregnancy diagnosis: a review

The developing embryo/fetus bears antigens which are foreign to the mother and it could be expected that immune rejection of the conceptus would occur. One of the reasons why the fetus is not rejected is because a depression of the maternal immune response takes place during pregnancy. Serum from pregnant animals of several species has been shown to contain a factor, early pregnancy factor (EPF), which is immunosuppressive. EPF has been detected as early as six hours after mating and its detection could aid diagnosis of early pregnancy in all species.     

Book reviews

The Economics of the Poultry Industry, by Eric S. Clayton. Longmans, Green and Co. Ltd, London. Price 36s.

Polymorphismes Biochimiques des Animaux. Xème Congrès européen sur les Groupes sanguins et le Polymorphisme biochimique des Animaux. INRA, Paris, 1967. Price 50NF.     

Mycobacterium bovis infection in a captive herd of Sika deer.

Infection with Mycobacterium bovis was diagnosed in a small privately owned herd of Sika deer. After postmortem examination of a deer with progressive pulmonary disease, diagnosis of infection with M bovis was confirmed by bacteriologic culture. The 2 remaining deer in this herd were euthanatized, necropsied, and confirmed to be infected with M bovis. Three cats in contact with the deer were also euthanatized and necropsied. One of these cats had lesions suggestive of mycobacterial infection in the colon and mesenteric lymph nodes. Infection of this cat with M bovis was not confirmed by bacterial culture. Mycobacteriosis, infrequently encountered in clinical veterinary practice, may be confused with disease caused by other infective agents or neoplasia. The zoonotic potential of these bacteria and a recent increase in human tuberculosis warrants continued surveillance of companion and food animal populations for mycobacterial infection.     

Effect of exocrine pancreatic insufficiency on cobalamin absorption in dogs

The possibility that the canine pancreas might have an important role in the physiologic absorption of cobalamin (vitamin B12) has been explored by determining the effect of exocrine pancreatic insufficiency on cobalamin absorption and by examining the subsequent influence of bovine pancreatic enzymes and canine pancreatic juice. Exocrine pancreatic insufficiency was induced by ligation of pancreatic ducts and confirmed by indirect assessment of exocrine pancreatic function. Cobalamin absorption was determined by oral administration of cyano[58Co]cobalamin and quantitation of radioactivity in blood, urine, and feces during 48 hours. Pancreatic duct ligation resulted in a significant (P less than 0.001) decrease in cobalamin absorption, which was not restored by oral administration of bovine pancreatic enzymes, despite considerable improvements in steatorrhea and in vivo proteolytic activities. In marked contrast, malabsorption of cobalamin was significantly (P less than 0.05) reversed by oral administration of canine pancreatic juice. These results indicate that pancreatic secretions have an important role in the normal absorption of cobalamin in the dog, a role that does not appear to be attributable to pancreatic enzymes, but is consistent with the existence of a pancreatic intrinsic factor in this species.     

The importation of the black rhinoceros (Diceros bicornis) from Zimbabwe into Australia

SUMMARY The paper describes a program to import and breed black rhinoceros ex situ at Western Plains Zoo in Australia. Nine rhinoceros (7 females and 2 males) captured in 1992 in Chete National Park, Zimbabwe, were transported to Australia via Cocos Island. The veterinary treatment of the animals before and during quarantine in Zimbabwe and on Cocos (Keeling) Islands is described. Three animals died; an adult male on Cocos Islands and a juvenile male and an adult female at Western Plains Zoo, Dubbo, New South Wales. The juvenile male died as a result of trauma sustained shortly after arrival and the two adults after developing a severe hepatopathy. The group of 6 females and an additional 4 males imported from the USA in 1994 have adapted well to captivity and to the climate and environment of central west New South Wales.