Characterization of lymphocytes in canine gastrointestinal lymphoma

Primary canine gastrointestinal lymphoma has been believed to be of B-cell origin based on the morphology and behavior of the neoplastic cells and the evidence from the human medical field. However, the neoplasms have not to date been characterized as to the origin of the cell population. Forty-four cases diagnosed as canine gastrointestinal lymphoma were retrieved from the records of the Veterinary Teaching Hospitals at the University of Minnesota and the University of Wisconsin-Madison. Four of the cases have been previously identified as epitheliotropic T-cell gastrointestinal lymphoma. Twenty-three of the dogs were female, with 11 intact and 12 neutered, and 21 of the dogs were male, with 12 intact and nine neutered. Sixteen breeds as well as individuals of mixed breeding were represented. The Boxer and the sharpei were the most commonly represented breeds with six individuals each. The age range of the dogs was 1.5-14.66 years, with two dogs identified as adult and two of unknown age. Archived tissue blocks of gastrointestinal samples were sectioned in duplicate and prepared for immunohistochemical staining with CD3 (T-cell marker) and CD20 (B-cell marker). In 75% of the cases examined under light microscopy, 50-95% of the neoplastic cells stained positively with CD3 and exhibited marked epitheliotropic behavior. In three of the cases, from 10% up to 50% of the neoplastic cells stained positively with CD20, with widely scattered CD3(+) cells. In the remainder of the cases, few to none of the neoplastic cells stained with either of the markers. This retrospective study shows that canine primary gastrointestinal lymphoma is more commonly of T-cell origin, rather than B-cell origin.     

Effect of canthaxanthin content of the maternal diet on the antioxidant system of the developing chick

1. Effects of canthaxanthin supplementation of the maternal diet on the antioxidant system of the developing chick were investigated. 2. Three hundred and twenty female broiler breeder birds were housed in one of 4 controlled environment rooms with 3 replicates for all treatments, with the exception of the control treatment of which there were 4 replicates. All birds received one of 5 diets: control low xanthophyll diet, or the same diet supplemented with 3, 6, 12 or 24 mg/kg canthaxanthin in the form of Carophyll Red. At 30 weeks of age 60 eggs from each of the 5 groups were incubated. At d 16 of the embryo development, at d 1 and d 7 posthatch tissue samples were collected and analysed by HPLC-based methods. 3. Canthaxanthin accumulation in the egg yolk was proportional to dietary content. Furthermore, at 12 to 24 mg/kg canthaxanthin was associated with an increase in gamma-tocopherol concentration in the egg yolk. Canthaxanthin was transferred from the egg yolk to the developing embryo and, as a result, its concentration in the liver of the embryo at 16 and in 1-d-old chicks was increased. Even at d 7 posthatch canthaxanthin concentration in the chicken liver was elevated. 4. Canthaxanthin supplementation of the maternal diet at 12 mg/kg was associated with an increased alpha-tocopherol concentration in the liver of 1-d-old chicks and resulted in decreased tissue susceptibility to lipid peroxidation. 5. Canthaxanthin supplementation at 6 to 24 mg/kg was also associated with a delay in alpha-tocopherol depletion from the liver for 7-d posthatch. As a result of the increased canthaxanthin and vitamin E concentrations in the liver of 7-d-old chicks, tissue susceptibility to lipid peroxidation decreased. 6. The results support an idea that dietary carotenoids can modulate antioxidant systems of the developing chicken.     

Quantitative ultrasound, magnetic resonance imaging, and histologic image analysis of hepatic iron accumulation in pigeons (Columbia livia).

Iron overload was induced by iron dextran i.v. in clinically healthy adult pigeons, Columbia livia, (n = 8). Hemosiderosis was induced in all treated birds. Two control pigeons received no iron injections. Pigeons did not show clinical signs of iron overload during the 6-wk study. Ultrasound examination of the liver in the pigeons receiving iron dextran was performed on days 0, 13, 28, and 42. No ultrasound images were collected on the control pigeons. Magnetic resonance imaging was performed on days 0, 13, 28, and 42 on all study pigeons and imaging sequences were collected in three different imaging formats: T1, T2, and gradient-recalled echo (GRE). Surgical liver biopsies were performed on pigeons receiving iron dextran on days 2, 16, and 45 (at necropsy). A single liver sample was collected at necropsy from the control birds. Histologic examination, quantitative image analysis, and tissue iron analysis by thin-layer chromatography were performed on each liver sample and compared to the imaging studies. Although hemosiderosis was confirmed histologically in each experimental pigeon, no significant change in pixel intensity of the ultrasound images was seen at any point in the study. Signal intensity, in all magnetic resonance imaging formats, significantly decreased in a linear fashion as the accumulation of iron increased.     

Risk characterisation and management of sewage sludge on agricultural land-implications for the environment and the food-chain

The disposal of sewage wastes may cause severe environmental problems as was graphically demonstrated with pollution on Sydney's ocean beaches in recent years. Sewage sludges contain valuable plant nutrients and organic matter which can improve the fertility and structure of the soil. However, human parasites, pathogenic micro-organisms and chemicals capable of causing soil contamination, phytotoxicity and residues in animal products may also be present. Although sewage sludge is frequently spread on agricultural land overseas, it is not common in Australia and most states do not have specific regulations to minimise risk and promote good practice. A sludge-to-land program began in the Sydney region in 1990. It follows guidelines written by NSW Agriculture to encourage beneficial agricultural use of sludge by adoption of environmentally sustainable practices. This article describes the major risks to the food-chain and the environment, which may be associated with applying sewage sludge to agricultural land. It summarises how the risks are managed, and where further research data are required.     

Effect of intrathecal and intravenous administration of oxytocin on amplitude of the reflex-evoked muscle action potential after electrical stimulation of the tooth pulp in anesthetized dogs

OBJECTIVE: To determine whether intrathecal (IT) or IV administration of oxytocin will diminish amplitude of the reflex-evoked muscle action potential (REMP) in the digastricus muscle during electrical stimulation of the tooth pulp in anesthetized dogs, thus suggesting an analgesic effect for oxytocin. ANIMALS: 6 male Beagles that were 2 to 6 years old. PROCEDURE: Dogs were used in a crossover design with at least a 5-day washout period between treatments. Each dog received morphine, saline (0.9% NaCl) solution, and oxytocin by both the IT and IV routes of administration. Noninvasive dental dolorimetry was used to assess changes in pain threshold following administration of treatments. Effectiveness of analgesia was determined on the basis of change in REMP amplitude in the digastricus muscle. RESULTS: Morphine administered IV significantly inhibited REMP amplitude, compared with IV administration of saline solution or oxytocin. There was not a significant change in REMP amplitude between saline solution and oxytocin administered IV. Intrathecal administration of morphine significantly inhibited REMP amplitude, compared with IT administration of saline solution or oxytocin. Intrathecal administration of oxytocin significantly increased REMP amplitude, compared with IT administration of saline solution or morphine. CONCLUSIONS AND CLINICAL RELEVANCE: Although IV administration of oxytocin did not have an effect on REMP amplitude, compared with IV administration of saline solution, IT administration of oxytocin had the opposite effect of morphine and increased REMP amplitude of the digastricus muscle. These data do not support the use of oxytocin as an analgesic agent in dogs.     

Primary anconeal fracture in a boxer

A 14-month-old speyed female Boxer was presented with acute non-weight-bearing lameness in the right forelimb. Radiography revealed separation of the anconeal process, which was thence surgically removed. Histological examination of the anconeal process confirmed a primary fracture. Isolated unilateral anconeal process fracture in the dog is rare and this report includes histopathological findings of a primary anconeal fracture.     

Iridociliary epithelial tumors in 100 dogs and 17 cats: a morphological study

The morphological features of iridociliary epithelial tumors in 100 dogs and 17 cats were reviewed. Twenty-seven cases were in either Golden Retrievers or Labrador Retrievers. Affected globes were stained for light microscopy with alcian blue, periodic acid Schiff (PAS) and hematoxylin and eosin stains. Selected tissues were examined by immunohistochemistry for vimentin, desmin, cytokeratin, S-100, neuron-specific enolase (NSE), and glial fibrillary acid protein (GFAP). The presence or absence of hyaluronic acid was recorded by staining with alcian blue before and after digestion of the tissue with hyaluronidase. Canine tumors were divided into papillary and solid tumors based on the pattern of growth. Twenty-eight of 57 papillary tumors exhibited invasive behavior including eight of the 57 which showed infiltration of the sclera. Twenty-nine of 43 solid tumors were invasive including 13 of 43 with scleral invasion. Tumors with scleral invasion were designated adenocarcinoma. Tumors of both types could be pigmented or nonpigmented and often contained smooth basement membranes reminiscent of the inner membrane of the nonpigmented ciliary body epithelial cell. All of the feline tumors were nonpigmented and 14 of 16 feline tumors were solid and two of the tumors were papillary. Eighteen of 20 canine tumors and three of four feline tumors stained positive for vimentin. Cytokeratin stain was positive only in a few of the highly aggressive tumors. The finding of pigmented epithelial cells, thick, smooth basement membrane structures, positive staining for vimentin, S-100, and NSE as well as hyaluronic acid deposition were considered to be features which define iridociliary epithelial tumors in dogs. The positive staining for vimentin and NSE are highly specific markers which help to characterize iridociliary epithelium and distinguish this tumor from metastatic epithelial tumors. The finding of solid nonpigmented tumors with small epithelial cells packeted by thin PAS-positive membranes staining positive for vimentin were considered significant features defining iridociliary epithelial tumors in cats. Follow-up information on survival and cause of death was obtained on 43 canine cases and only two feline cases. The average follow-up interval in dogs was 25 months and only two dogs died with lesions that could have been due to metastasis although neither was confirmed. We concluded that neither iridociliary adenomas nor adenocarcinomas is likely to metastasize.     

Breeding Soundness Evaluation and Semen Analysis for Predicting Bull Fertility

Bull fertility is influenced by numerous factors. Although 20–40% of bulls in an unselected population may have reduced fertility, few are completely sterile. Breeding soundness refers to a bull's ability to get cows pregnant. A standard breeding soundness evaluation identifies bulls with substantial deficits in fertility, but does not consistently identify sub-fertile bulls. In this regard, the use of frozen-thawed semen (from bulls in commercial AI centres) that meets minimum quality standards can result in pregnancy rates that differ by 20–25 percentage points. Although no single diagnostic test can accurately predict variations in fertility among bulls that are producing apparently normal semen, recent studies suggested that a combination of laboratory tests were predictive of fertility. This review is focused on recent developments in prediction of bull fertility, based on assessments at the molecular, cellular and whole-animal levels.