Acquisition of luteolytic capacity involves differential regulation by prostaglandin F2alpha of genes involved in progesterone biosynthesis in the porcine corpus luteum

Luteolytic capacity is defined as the ability of corpora lutea (CL) to undergo luteolysis after prostaglandin (PG) F2alpha treatment. The mechanisms causing acquisition of luteolytic capacity are not yet identified but CL without luteolytic capacity have PGF2alpha receptors and respond to PGF2alpha with some changes in gene expression. Inhibition of progesterone biosynthesis is a key feature of luteolysis and therefore we postulated that genes involved in progesterone biosynthesis would be regulated by PGF2alpha differently in CL with or without luteolytic capacity. Gilts on day 9 after estrus (lack luteolytic capacity) or day 17 of pseudopregnancy (with luteolytic capacity) were treated with saline or a PGF2alpha analog (cloprostenol) and CL were collected 0.5 (Experiment I) or 10 h (Experiment II) later. In Experiment III, large luteal cells from CL on day 9 or 17 were cultured for 1, 12 and 24h with or without PGF2alpha. PGF2alpha decreased LDL receptor mRNA (27%), steroidogenic acute regulatory protein (StAR) mRNA (41%), StAR protein (75%), LH receptor mRNA (55%), and LH receptor protein (45%) at 10 h after treatment in day 17 but not day 9 CL. PGF2alpha increased DAX-1 mRNA at 0.5 h (43%) and 10 h (46%) after PGF2alpha in day 17 but not day 9 CL but decreased 3betaHSD mRNA ( approximately 20% at 10 h) in both days 9 and 17 CL. In vitro, PGF2alpha decreased StAR mRNA at 12 h only in day 17 luteal cells; however, continuous treatment with PGF2alpha for 24 h decreased StAR mRNA in both days 9 and 17 luteal cells. Thus, luteolytic capacity involves a critical change in responsiveness of DAX-1, StAR, and LH receptor to PGF2alpha that results in inhibition of luteal progesterone biosynthesis.     

Plasma pro-opiomelanocortin, pro-adrenocorticotropin hormone, and pituitary adenoma size in dogs with Cushing's disease

It is difficult to predict the size of pituitary corticotroph tumors in dogs with Cushing's disease (pituitary-dependent hyperadrenocorticism [PDH]) without pituitary imaging techniques. The purpose of this study was to examine the relationship between plasma adrenocorticotropin hormone (ACTH) precursor concentration and pituitary size in dogs with Cushing's disease. Plasma concentrations of ACTH precursors (pro-opiomelanocortin [POMC]/pro-ACTH) and pituitary tumor height/brain area were measured in 36 dogs with pituitary corticotroph adenomas of various sizes. There was a correlation between tumor size (measured as the pituitary tumor height/brain area ratio [P/B]) and POMC/pro-ACTH concentration (r = .70; P < .0001). Dogs with P/B > or = 0.40 x 10(-2) mm(-1) had higher concentrations of ACTH precursors than dogs with P/B < 0.40 x 10(-2) mm(-1) (median concentration 85 pmol/L, range 15-1,350 pmol/L, n = 14 versus 15 pmol/L, range 15-108 pmol/L, n = 22; P < .0001). With a threshold of 35 pmol/L of POMC/pro-ACTH concentration, the estimated sensitivity and specificity of the kit were 93% (95% confidence interval [CI], 79-100%) and 86% (95% CI, 73-100%), respectively. We interpret these data as indicating that measurement of POMC and pro-ACTH might be of value in the characterization of tumor size in dogs with Cushing's disease. Low POMC/pro-ACTH concentrations make it unlikely that a large pituitary tumor exists in dogs with PDH.     

Evaluation of intravenous pamidronate administration in 33 cancer-bearing dogs with primary or secondary bone involvement

The purpose of this study was to evaluate the clinical safety of pamidronate when administered at a mean dosage of 1.0 mg/kg IV q28d in 33 tumor-bearing dogs. Biochemical tests of renal function were evaluated before each successive pamidronate treatment. Of 33 dogs treated with pamidronate, 1 dog had clinically relevant increases in serum creatinine and blood urea nitrogen concentrations. The biologic activity of IV pamidronate was assessed prospectively in 10 dogs with appendicular osteosarcoma and was assessed on reductions in urine N-telopeptide excretion (P = .042) and enhanced bone mineral density of the primary tumor measured with dual-energy x-ray absorptiometry (P = .024). Additionally, in these 10 dogs, pamidronate's therapeutic activity was supported by subjective improvement in pain control in 4 of the 10 dogs treated. IV pamidronate appears clinically safe in tumor-bearing dogs and may possess modest biologic activity for managing neoplastic complications associated with pathologic bone resorption.     

Experiences and difficulties encountered during a course on veterinary public health with students of different nationalities

Veterinary public health (VPH) issues have received increased attention over the last few years as a result of the rising threat of emerging zoonoses (i.e., those due to globalized trade in animal and animal products and to changes in livestock production systems and the environment). The international dimension of VPH is gradually becoming recognized, and there is a growing need for veterinarians with experience in this field. In order to familiarize (future) veterinarians with the international dimension of VPH, the Department of Public Health and Food Safety of the Faculty of Veterinary Medicine, Utrecht University, has been organizing a course in Veterinary Public Health and Animal Production for over the last 10 years. This course has been intended for Dutch as well as foreign final-year veterinary students and recent veterinary graduates. By bringing together participants from different countries, the course reinforces the international dimension of the issues addressed through the exchange of experiences by the participants themselves. The present article provides information about this course on Veterinary Public Health (VPH): it discusses logistics, didactical approaches, the course program, and the use of information and communication technology (ICT). Special attention is given to the intercultural aspects of higher education, all of which play an important role in the efficient exchange of knowledge between lecturers and students. International courses are an important tool to enable participants to interact in a multicultural environment and address issues that demand international cooperation and a global public health focus.     

Cardiopulmonary effects of desflurane in horses

OBJECTIVE: To determine the cardiopulmonary effects of desflurane (DES) in horses. ANIMALS: Six healthy adult horses, three males and three females, aged 9 +/- 4 (mean +/- SD) years and weighing 370 +/- 36 kg. MATERIALS AND METHODS: Anaesthesia was induced with an O2 (10 L minute(-1)) and DES mixture (vaporizer setting 18%). After oro-tracheal intubation, horses were positioned in right lateral recumbency. Anaesthesia was maintained with DES in O2 (20 mL kg(-1) minute(-1)) delivered through a large animal circle breathing system. The minimum alveolar concentration of DES (MAC(DES)) that prevented purposeful movement in response to 60 seconds of electrical stimulation of the oral mucous membranes was determined for each horse. The delivered concentration of DES was then increased to achieve end-tidal concentrations corresponding to 1.5 x MAC(DES), 1.75 x MAC(DES), and 2.0 x MAC(DES). Heart rate (HR), mean arterial blood pressure (MAP), respiratory rate (fr), tidal volume (VT), minute volume (VM) and core temperature were determined, and blood samples for arterial blood gas analysis taken at each DES concentration. All data were analysed by two-way anova for repeated measures and Fisher's test for multiple comparisons. A probability level of p < 0.05 was applied. RESULTS: Desflurane concentrations of 2.0 x MAC(DES) increased HR whereas lower concentrations did not. Mean arterial pressure was not affected by 1.0 x MAC(DES) 1.5 x MAC(DES) or 1.75 x MAC(DES), whereas it decreased at 2.0 x MAC(DES). All concentrations of DES examined significantly depressed fr, VT and VM. CONCLUSIONS AND CLINICAL RELEVANCE: Desflurane concentrations between 1.0 and 1.75 x MAC(DES) reduces fr and VM but does not affect HR or MAP in horses.     

Land Cover Type and Fire in Portugal: Do Fires Burn Land Cover Selectively?

The purpose of this study is to investigate if, or under what conditions, fires select given land cover types for burning. If fires burn unselectively then the land cover composition (the proportional area of various land cover types) of individual fires should approximate the land cover composition available in their neighborhood. In this study we test this hypothesis by performing statistical analyses of a data set consisting of paired vectors with the proportions of land cover types present in burned areas and in their respective surroundings. The statistical methods employed (a permutation technique and the C_max statistic) are commonly used in resource selection studies where data is subject to a unit-sum constraint. The results of the analysis of 506 fires that burned in Portugal in 1991 indicate that fires are selective, with small fires exhibiting stronger land cover preferences than large fires. According to the results of a multiple comparison analysis performed for small fires, there is a marked preference for shrubland followed by other forest cover types, while agriculture is clearly avoided. A similar analysis is performed to test if fire selectivity is related to the ecological region where it occurs. The results obtained in this study contribute to the discussion on the relative importance of fuels as a drivers of fire spread.     

Seroepidemiology of Toxoplasma gondii and Neospora caninum in dogs from the state of Paraíba, Northeast region of Brazil

A cross-sectional study was conducted to determine the seroprevalence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies and to investigate the risk factors related to antibodies against T. gondii and N. caninum in dogs of the city of Campina Grande, state of Paraiba, Northeast region of Brazil. For this purpose, 286 blood samples were collected from dogs during the rabies vaccination campaign, in September 2003, and on this occasion questionnaires addressing epidemiological aspects of the infections were given to each dog owner. The sera were analyzed for anti-T. gondii and anti-N. caninum antibodies by indirect fluorescent antibody tests. Of the total of 286 dogs, 129 were positive for T. gondii (titer16) with a prevalence value of 45.1% (95% CI=39.24-51.07%). For N. caninum, 24 dogs were positive (titer50), with a prevalence value of 8.4% (95% CI=5.45-12.23%). Antibodies to T. gondii and N. caninum were found simultaneously in 14 dogs (4.9%; 95% CI=2.7-8.08%). For T. gondii infection, the risk factors associated with seroprevalence was the age of the animals, with dogs older than one year presenting higher values of odds ratio, and co-habitation of cats in the household. For N. caninum infection, dogs that have street contact had higher odds of seropositivity than dogs that remained exclusively in a domestic environment.     

A PCR technique for the detection of Jaagsiekte sheep retrovirus in the blood suitable for the screening of ovine pulmonary adenocarcinoma in field conditions

Ovine pulmonary adenocarcinoma (OPA) is a naturally occurring contagious lung neoplasia caused by jaagsiekte sheep retrovirus (JSRV). Although no specific circulating antibodies against the virus can be detected in infected sheep, JSRV proviral DNA sequences can be found in peripheral blood leukocytes (PBLs) in clinically affected and in a proportion of in contact animals. In this study, existing hemi-nested PCR procedure is compared with a new one-step PCR technique that was developed to minimise potential DNA contamination and reduce sample and reagent handling. Different blood preparations were assessed and the best results were achieved on DNA prepared from buffy coat. The sensitivity of this PCR was lower in JSRV infected sheep without lesions of OPA than in clinically affected sheep, which indicate that this PCR may not be not fully appropriate for screening of individual sheep, but rather to provide results at flock level. This PCR is the only currently available blood test for detection of JSRV infected sheep and may be useful in epidemiological studies and in control programmes of OPA.     

Large animal practitioners' perspective of their patients and clients and their professional responsibilities

Veterinarians have obligations towards both the animals they treat and their clients, the owners of the animals. Veterinarians have complicated, and often conflicting, relationships with both groups. In this article, Q-methodology was used as a method for discourse analysis to determine how Dutch large animal practitioners conceptualize animals and their owners and their professional responsibilities towards both. The article focuses on four different perspectives that Dutch veterinarians have of their animal patients and their owners, and of their professional duties and responsibilities.