Determination of the oxidative burst chemiluminescent response of avian and murine-derived macrophages versus corresponding cell lines in relation to stimulation with Salmonella serotypes.

In contrast to mammalian systems, avian species lack a resident or harvestable macrophage population in the abdominal exudate. Peritoneal macrophages in the chicken can be elicited if an inflammatory agent such as sephadex is injected. This study examines the kinetics of different macrophage populations, derived by different methods of isolation and from different hosts, with respect to the elicited oxidative burst upon infection with host-adapted Salmonella serotypes.

The nature of the oxidative burst elicited by murine and avian-derived and cell line macrophages was determined after stimulation with phorbol myristate (PMA), zymosan A, and Salmonella serotypes. Both murine and chicken peritoneal macrophages, chicken blood monocytes and corresponding cell lines, J774A.1 and HD-11, were unable to produce a detectable chemiluminescent (CL) response after interaction with Salmonella using the luminescent probe luminol. However, both PMA and zymosan A induced a CL response in all cell types, with PMA eliciting a higher and earlier peak response (pkH) than zymosan A. Lucigenin-enhanced CL in both murine and chicken macrophages was achieved with PMA, zymosan A and Salmonella serotypes. In this case, zymosan A induced higher responses than PMA. In the peritoneal macrophages of both hosts, there were no significant differences in the oxidative burst induced by the different Salmonella serotypes. However, the J774A.1 (murine) cells demonstrated significant differences, with S. enterica serotype Choleraesuis (S. choleraesuis and S. gallinarum producing the highest response. In the HD-11 (chicken) cells, S. choleraesuis and S. dublin elicited the higher CL. With both cell lines, S. abortusovis failed to induce an appreciable CL response.

In these experiments it was demonstrated that oxidative burst was not detectable in monocytes/macrophage populations using luminol, which suggests a link to the lack of a myeloperoxidase system in these cells. Lucigenin-enhanced CL appeared independent from the myeloperoxidase system, indicating production of another oxidative species compared with luminol. No discernable effect of host specificity with regard to Salmonella serotype and respective host was seen in host-derived or cell line macrophages, and cell line macrophages displayed altered functional characteristics with regard to oxidative burst in comparison with their primary counterparts.     

Pharmacologic management in veterinary behavioral medicine.

As our knowledge expands, behavioral pharmacology plays an increasingly important role in behavioral medicine. Drugs traditionally categorized as anxiolytics, antidepressants, anticonvulsants, and hormones may be used to help manage a range of animal behavioral problems. Knowledge of how these agents act in the body and interact with other agents is imperative for safe and efficacious use.     

RADIATION PNEUMONITIS IN THREE DOGS

Radiation pneumonitis developed within the radiation treatment field in three dogs with soft tissue sarcomas located on or adjacent to the thoracic wall. Radiographic signs compatible with a diagnosis of radiation pneumonitis developed from one (n = 2 dogs) to two (n = 1 dog) months after completion of therapy. The initial radiographic sign was an alveolar infiltrate in all three dogs. At subsequent examinations at variable time periods after treatment, radiographic findings included: bronchiectasis (n = 3 dogs), alveolar infiltrate (n = 2 dogs), decreased lung volume (n = 2 dogs), and unstructured interstitial opacification (n = 1 dog). Necropsy examination of one dog at fourteen months after the completion of radiotherapy showed evidence of pulmonary fibrosis within the irradiated lung. Necropsy examination of the second dog did not show any evidence of radiation induced changes. It is possible that histopathologic examination did not include irradiated lung. No clinical signs that could be attributed to the radiation pneumonitis were observed in any dog. It appears that approximately 25% of the lung can be safely irradiated to high doses, if indicated, in order to deliver an adequate dose of radiation to a primary tumor site.     

Serum chemistry alterations in Alaskan sled dogs during five successive days of prolonged endurance exercise

OBJECTIVE: To determine the impact of successive days of endurance exercise on select serum chemistry values in conditioned Alaskan sled dogs. DESIGN: Prospective cohort study. ANIMALS: 10 conditioned Alaskan sled dogs. PROCEDURES: All dogs ran 160 km/d for 5 consecutive days. Serum was obtained prior to exercise and immediately after each exercise run; all samples were obtained before dogs were fed. Serum electrolyte, mineral, protein, total bilirubin, urea nitrogen, creatinine, and cardiac troponin-I concentrations and serum alkaline phosphatase, alanine aminotransferase, creatine kinase, and aspartate aminotransferase activities were measured. Data were analyzed by means of analysis of covariance for a randomized complete block design with dog as a blocking variable, time as a covariate, and distance run as the treatment of interest. Least square mean values were compared with values obtained prior to exercise, and linear and quadratic contrasts were examined. RESULTS: Serum globulin concentration was low prior to exercise (mean +/- SD, 2.2 +/- 0.3g/dL) and progressively decreased as exercise continued. Exercise was associated with increases in serum chloride, urea nitrogen, and cardiac troponin-I concentrations and serum alanine aminotransferase, creatine kinase, and aspartate aminotransferase activities and with progressive decreases in serum potassium, total protein, and albumin concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that multiple successive days of endurance exercise resulted in mild aberrations in serum chemistry variables in conditioned sled dogs. Changes likely reflected the metabolic stresses of prolonged endurance exercise as well as dietary composition. Hypoglobulinemia in resting, conditioned sled dogs may reflect the immunosuppressive or catabolic effects of intense endurance training.     

Evaluation of four point-of-care meters for rapid determination of blood lactate concentrations in dogs

OBJECTIVE: To determine whether blood lactate values determined in dogs with 4 commercially available point-of-care meters were in agreement with values determined with a critical care laboratory blood analyzer. DESIGN: Prospective study. ANIMALS: 50 dogs evaluated for emergency treatment. PROCEDURES: Blood samples were collected at initial evaluation and processed on 4 point-of-care meters and on a critical care laboratory blood analyzer. RESULTS: All 4 point-of-care lactate meters generated measurements that were in agreement with the hospital's critical care analyzer. Values for agreement (bias) between the 4 point-of-care meters and the critical care analyzer were -0.652 (limits of agreement [LA], -1.958 to 0.654]), -0.670 (LA, -2.110 to 0.769), -0.096 (LA, -2.071 to 1.879), and -0.498 (LA, -2.616 to 1.620), respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Despite its prognostic and therapeutic relevance, blood lactate measurement in dogs has been hampered by the inability to perform the test in a timely fashion. Results of the present study indicated that several handheld point-of-care lactate meters provided results that were in agreement with a laboratory critical care blood analyzer.     

The importance of population growth, seed dispersal and habitat suitability in determining plant invasiveness

Summary This paper examines the roles of plant demography, seed dispersal ecology and habitat suitability in influencing invasiveness of horticulturally important species. Section one investigates the relative invasiveness of two woody species, Crataegus monogyna and Prunus mahaleb, and concentrates on differences in demographic and dispersal traits. The second section delineates the invasion of two Asparagus spp. and concentrates on differences in seed dispersal ecology. Section three reports the use of a geographical information system analysis to determine whether habitat suitability, seed dispersal or land management is more important in determining threat of invasion by adventive Olea europaea. C. monogyma, P. mahaleb are closely related with similar habits and overlapping home ranges in Europe. Crataegus monogyna is very invasive in northern New South Wales, having spread rapidly and conspicuously throughout the region and elsewhere in southern Australia at rates of 80–120 m yr⁻¹. Prunus mahaleb is far less invasive, being restricted to a small population, which is expanding at 20 m yr⁻¹. Demographic analysis showed that potential growth rates of P. mahaleb (1.713–1.490) are greater than those for C. monogyna (1.138–1.103). Assessment of the seed dispersal ecology of both species revealed that C. monogyna had seeds dispersed by one bird and three mammals over many kilometers. P. mahaleb had seeds dispersed by six birds and four mammals over distances generally < 100 m. The role of humans in introducing both species and the characteristics of seed dispersal are more influential than demography in determining invasiveness. The more invasive Asparagus asparagoides has smaller fruit with a bicoloured display up to 1.5 m above ground. Less invasive A. declinatus has larger, translucent white fruit displayed at heights < 0.5 m above ground. The role of humans has also been important in shaping the course of invasion. Sensitivity analysis confirms that land management practices, which affect Olea europaea seedling establishment and survival, are most important at a landscape scale in determining invasiveness. The main factors determining the difference in invasiveness relate directly to the changing nature of human management of each species and the ecological interactions between the plants and the invaded environment. This research has implications for the prediction and management of biological invasions; emphasizing the importance of seed dispersal and human activities in determining the course of invasions: both of which cannot be readily predicted.     

Precision of genetic relationship estimates based on molecular markers

Genetic progress through selection is directly related to the amount of variability present in the population and the quality of genes contributed by the parents. Genetic relationships between lines were studied using DNA marker-based estimates of genetic similarity. A statistical methodology using the width of a confidence interval was developed to determine the number of probes to be surveyed and the precision in the estimation of genetic distance between pairs of cultivars. Precision was affected by type of genetic distance used, the number of cultivars, and amount of genetic diversity present in the studied group. The width of a (1-α)% confidence interval decreased as the number of RFLP fragments increased. Oat and wheat diversity studies were used to illustrate the methodology. This revised version was published online in July 2006 with corrections to the Cover Date.