Experimental infection of Attwater's/greater prairie chicken hybrids with the reticuloendotheliosis virus

Reticuloendotheliosis virus (REV), a common pathogen of poultry, has been associated with runting and neoplasia in an endangered subspecies of grouse, the Attwater's prairie chicken. The pathogenesis of REV infection was examined in experimentally infected prairie chickens. Three groups of four Attwater's/greater prairie chicken hybrids were infected intravenously with varying doses (tissue culture infective dose [TCID50], 200, 1000, and 5000) of a prairie chicken-isolated REV. A fourth group of four birds was not infected. Blood was collected prior to infection, and at various times up to 37 wk following infection. Peripheral blood mononuclear cells were examined for integrated proviral DNA by a single-amplification polymerase chain reaction (PCR) and nested PCR of a region within the pol gene. The nested PCR identified REV proviral DNA in all REV-inoculated birds by 2 wk postinfection and confirmed chronic infection throughout the study. With the exception of a bird that died from bacterial pneumonia 8 wk postinfection, neoplasia, resembling that seen in naturally occurring infections, was observed in all birds, even those receiving as little as 200 TCID50 of virus.     

Cyclooxygenase expression in the early stages of equine laminitis: a cytologic study

BACKGROUND: Recent reports indicate increased amounts of mRNA from inflammation-related genes in the prodromal stage of laminitis. HYPOTHESIS: Cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) undergo distinct patterns of expression in equine laminae in the developmental stage (DEV) and acute clinical stage (LAM) of laminitis. ANIMALS: Horses selected from an outbred population were placed into 1 of 4 groups: DEV (n = 5), CON-3h (control group for DEV, n = 5), LAM (n = 5) and CON-10h (control group for LAM, n = 5). METHODS: Laminar and skin samples were obtained from (1) animals either undergoing leukopenia (DEV) or the onset of clinical signs of laminitis (LAM) after black walnut extract (BWE) administration and (2) animals either 3 (CON-3h) or 10 (CON-10h) hours after administration of water. Real-time quantitative polymerase chain reaction (RT-qPCR), immunoblotting, and immunohistochemical analysis were performed for COX-1 and COX-2. RESULTS: Upon immunohistochemical analysis of all 4 groups, COX-2 was expressed by most viable epithelial cells in both laminae and skin. COX-1 exhibited similar epithelial expression to COX-2 in skin epidermis, but was expressed exclusively in the basal layer of laminar epidermis. COX-1 protein was not detectable in dermal vasculature of equine skin or laminae, whereas COX-2 was present in endothelial and vascular smooth muscle cells of dermal vasculature in both skin and laminae in all groups. A marked increase in laminar COX-2 protein concentrations was detected on immunoblotting in the DEV group, although a lesser increase was observed in the LAM group. CONCLUSIONS AND CLINICAL IMPORTANCE: COX-2 protein expression is markedly increased in the resident laminar cell types in the developmental stage of BWE-induced laminitis.     

Effects of oral administration of controlled-ileal-release budesonide and assessment of pituitary-adrenocortical axis suppression in clinically normal dogs

OBJECTIVE: To evaluate the effects of oral administration of controlled-ileal-release (CIR) budesonide on the pituitary-adrenal axis in dogs with a normal gastrointestinal mucosal barrier. ANIMALS: 10 healthy dogs. PROCEDURES: 5 dogs received CIR budesonide orally once daily for days 1 through 28, and 5 dogs received placebo. Treatment group dogs that weighed < 18 kg received 2 mg of CIR budesonide; treatment group dogs that weighed > or = 18 kg received 3 mg of CIR budesonide. In the treatment and placebo groups, there were 3 and 2 dogs, respectively, that weighed > 18 kg. Plasma cortisol concentration before and after ACTH stimulation, basal plasma endogenous ACTH concentration, and body weight were measured on days 0, 7, 14, 21, 28, and 35. Serum biochemical analysis, CBC determination, and urinalysis were performed on days 0, 28, and 35. On days 7, 14, and 21, serum ALP and ALT activities, serum glucose concentration, and urine specific gravity were obtained in lieu of a full hematologic evaluation and urinalysis. RESULTS: Basal and post-ACTH stimulation plasma cortisol concentrations and plasma endogenous ACTH concentration were significantly suppressed by treatment. No other variables were altered over the course of the study. CONCLUSIONS AND CLINICAL RELEVANCE: Budesonide suppresses pituitary-adrenal function in dogs with normal gastrointestinal integrity, whereas other variables often affected by glucocorticoids were not altered by a 4-week treatment course. Budesonide may be a good alternative to traditional cortico-steroids if used short-term for acute exacerbations of inflammatory bowel disease.     

Effect of adrenalectomy on cholecystokinin-8-induced Fos-like immunoreactivity in myenteric neurons and the dorsal vagal complex in rats

OBJECTIVE: To investigate the effect of adrenalectomy on cholecystokinin-8 (CCK-8)-induced Fos-like immunoreactivity (Fos-LI) in the myenteric neurons of the dorsal vagal complex (DVC) in rats. ANIMALS: 16 male Sprague Dawley rats. PROCEDURES: Rats were allocated to 1 of 2 groups and underwent adrenalectomy or a sham adrenalectomy procedure. Rats were challenged with a supraphysiologic dose of CCK-8 (40 microg/kg) or physiologic saline (0.9% NaCl) solution (0.5 mL) administered IP; after 90 minutes, rats were euthanized, and Fos-LI was quantified in the DVC (at the levels of the area postrema, nucleus tractus solitarii, and dorsal motor nucleus of the vagus) and the myenteric neurons of the duodenum and jejunum by use of a diaminobenzidine reaction enhanced with nickel. The Fos-LI-positive cells were counted by use of an automated system and manually in the DVC and intestinal samples, respectively. Counts of Fos-LI in the different hindbrain levels and myenteric neurons were compared between the adrenalectomy--and shamtreated groups and between the CCK-8- and saline solution-treated groups. RESULTS: After adrenalectomy, CCK-8-induced Fos-LI was attenuated only in the myenteric neurons of the duodenum. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that the adrenal gland has a role in the activation of myenteric neurons by CCK-8 in rats.     

Impact of diet on development of bronchial-associated immunity in the neonatal piglet

Bronchial-associated immune development is critically important to protect neonates from respiratory infections. Herein, bronchial-associated immune development in formula-fed and sow-reared pigs is described. Colostrum-fed newborn piglets were fed medicated sow milk replacer formula beginning at 48 h of life or remained with the sow. Blood and tissues were sampled at one-week (d7) and three-weeks (d21) of age. Lymphocyte subpopulations, including T helper 2, cytotoxic T, memory T, and NK cells, in peripheral blood, mediastinal lymph nodes, and thoracic lymph nodes were identified using flow cytometry. Additionally, IL-1β, IL-6, IL-12, TNFα, TGF-β1, TGF-β2, IFNα, IFNβ, and dectin gene expression were analyzed by quantitative RT-PCR. Total IgG, IgM, and IgA concentrations in serum were analyzed. Dietary and developmental effects were observed. This set of baseline measurements provides a framework for future respiratory challenge studies where the effects of diet on the neonate's ability to resist and/or recover from infection can be tested.     

A study of the pattern of staphylococcal contamination of the udders of cows in a dairy herd

Abstract

Extract

The results of the 1965–6 New Zealand national mastitis survey (Anon., 1967 Anon Ann. Rep. Res. Div. N.Z. Dept. Agric. 1966–67 1967 77 78  [Google Scholar]) indicated that β-haemolytic staphylococci were the most common bacteria isolated from the milk of dairy cows. Effective control of β-haemolytic stapyhlococci on a national scaledepends ultimately upon an understanding of population changes of this organism within the cow and within the herd.     

Effect of staphylococcal contamination of the bovine udder on milk yield

Zinc sulphate was added to the drinking water of Angus cows and calves grazing an area considered marginal for copper nutrition of cattle. Mean daily intakes of approximately 12–15 mg Zn/kg live-weight further depressed already low plasma copper concentrations to levels considered to indicate copper deficiency. The plasma copper concentrations in untreated animals increased during the trial indicating adequate copper intakes during this period, but the high zinc intakes of treated animals prevented this seasonal rise. Injection of copper glycinate (0.24 g/animal) alleviated the depression of plasma copper associated with the high zinc intakes. The zinc supplements had little effect on plasma zinc concentrations.     

The effect of staphylococcal antigen on the output of cells from the popliteal lymph node of immunized sheep

Serum samples collected from dogs routinely presented at a clinic between June 1974 and October 1980 were tested for the presence of haemagglutination inhibition (HI) titres to canine parvovirus. The first positive titre (> 1:320) was demonstrated in serum collected in October 1979. The first confirmed clinical case of canine parvovirus enteritis was diagnosed by the authors in July 1979.

In addition, between 1st December 1980 and 1st March 1981, serum samples were collected from 106 healthy dogs which were presented for canine parvovirus vaccination for the first time. Twenty-four dogs (approx. 23%) showed HI titres > 1:320 indicating probable previous canine parvovirus infection. Therefore approx. 80% of dogs in the clinic area were at risk at that time and vaccination should have protected them from infection.