Evaluation of magnetic resonance imaging for the differentiation of inflammatory,neoplastic, and vascular intradural spinal cord diseases in the dog

Magnetic resonance imaging (MRI) is a common test for dogs with suspected intradural spinal cord lesions, however studies on diagnostic performance for this test are lacking. Objectives of this multi‐institutional, retrospective, case‐control study were to estimate sensitivity and specificity of MRI for (1) distinguishing between histopathologically confirmed intradural spinal cord disease versus degenerative myelopathy in dogs, (2) categorizing intradural spinal cord diseases as neoplastic, inflammatory, or vascular; and (3) determining tumor type within the etiologic category of neoplasia. Additional aims were to (1) determine whether knowledge of clinical data affects sensitivity and specificity of MRI diagnoses; and (2) report interrater agreement for MRI classification of intradural spinal lesions. Cases were recruited from participating hospital databases over a 7‐year period. Three reviewers independently evaluated each MRI study prior to and after provision of clinical information. A total of 87 cases were sampled (17 degenerative myelopathy, 53 neoplasia, nine inflammatory, and eight vascular). Magnetic resonance imaging had excellent (>97.6%) sensitivity for diagnosis of intradural spinal cord lesions but specificity varied before and after provision of clinical data (68.6% vs. 82.4%, P = 0.023). Magnetic resonance imaging had good sensitivity (86.8%) and moderate specificity (64.7–72.5%) for diagnosing neoplasia. Sensitivity was lower for classifying inflammatory lesions but improved with provision of clinical data (48.1% vs. 81.5%, P = 0.015). Magnetic resonance imaging was insensitive for diagnosing vascular lesions (25.0%). Interrater agreement was very good for correctly diagnosing dogs with intradural lesions (? = 0.882–0.833), and good (? = 0.726–0.671) for diagnosing dogs with neoplasia.     

Non-GMO vs organic labels: purity or process guarantees in a GMO contaminated landscape

Since 2010, demand for non-GMO food products has grown dramatically. Two non-GMO labels dominate the market: USDA Organic and the Non-GMO Project Verified (the Project). However, the non-GMO status of Organic is not obvious from the label and many consumers are unaware of this. As sales of products carrying the Project’s non-GMO label have exploded, concern has increased among some Organic proponents that demand for non-GMO threatens the organic market. In response, both sides are seeking to build legitimacy and authority for their label by emphasizing the value of their standards for determining a food product’s non-GMO status within a GMO contaminated agrifood system. Drawing on in-depth interviews with key informants with knowledge of non-GMO standards and labels, we examine the knowledge systems, discourses and actors that proponents of the Project and USDA Organic privilege in their effort to legitimize their standards. Here, the Project emphasizes its application of technoscientific norms, especially thresholds and testing, which they argue provide the best means for preventing GMO contamination and helping consumers find (relative) non-GMO ‘purity’. In contrast, proponents of Organic favor a process standard that excludes GMOs, arguing that non-GMO ‘purity’ is unrealistic in today’s agrifood system that is widely contaminated by GMOs and where mandatory testing would unnecessarily harm organic producers. We conclude that tensions between the two groups are unlikely to be easily reconciled since these two distinct marketing labels rely on different knowledge and verification claims to vie for consumers and increase market share.     

Cytokine expression by pulmonary leukocytes from calves challenged with wild-type and leukotoxin-deficient Mannheimia haemolytica

The objective of this study was to assess the role of leukotoxin (LKT) in modulating the pulmonary cytokine response of calves challenged with Mannheimia haemolytica. Thirty-six calves, seronegative to LKT and M. haemolytica whole cell antigen were divided into three groups (I, II and III). Calves in groups I and II were challenged by the intra-bronchial route with 25 mL of phosphate buffered saline (PBS) containing 0.44×10(9) cfu/mL of LKT deficient (lkt(-)) and 25 mL of PBS containing 0.31×10(9) cfu/mL of wild-type (wt) M. haemolytica serotype 1, respectively. Group III calves were challenged intra-bronchially with 25 mL of sterile PBS. Leukocytes were collected from broncho-alveolar lavage fluid (BALF) 4 days before and at 1, 3, and 6 days post-inoculation (p.i.). Expression of the following cytokines in the recovered leukocytes was measured using real-time PCR: interleukin (IL)-1β, -8, -10, -12 (p40) and TNF-α. The amount of TNF-α produced was also quantified by ELISA. Although a statistically significant difference in the expression of these cytokines was not observed between groups challenged with the wt and lkt(-) strains, the wt infected group (II) did exhibit higher mean clinical scores. Overall, there was considerable variation in the composition of the BALF between the groups and by day 7 p.i., both lkt(-)- and wt-challenged calves had seroconverted to M. haemolytica.     

Use of observed wild bird activity on poultry farms and a literature review to target species as high priority for avian influenza testing in 2 regions of Canada

The risk of avian influenza outbreaks in poultry is partially dependent on the probability of contact between domestic poultry and wild birds shedding avian influenza (AI) virus. The major objective of this study was to document wild bird activity on poultry farms to determine which wild bird species should be targeted for AI surveillance in Canada. We collected data in 2 major poultry producing regions of Canada, southwestern Ontario and the Fraser Valley of British Columbia, on the relative abundance of various wild bird species found on poultry farms and on how these species utilized habitat around poultry farms. We reviewed the published literature to determine what was known about AI pathobiology in the species we observed. From these results we created a list of 10 wild bird species that are a priority for further study. These species are the European starling, barn swallow, rock dove, American crow, northwestern crow, American robin, dark-eyed junco, song sparrow, horned lark, and common grackle. Abundance of these and other species varied between provinces and seasons.     

Effect of triple superphosphate and biowaste compost on mycorrhizal colonization and enzymatic P mobilization under maize in a long‐term field experiment

Phosphorus (P) fertilizers and mycorrhiza formation can both significantly improve the P supply of plants, but P fertilizers might inhibit mycorrhiza formation and change the microbial P cycling. To test the dimension and consequences of P fertilizer impacts under maize (Zea mays L.), three fertilizer treatments (1) triple superphosphate (TSP, 21–30 kg P ha^?1 annually), biowaste compost (ORG, 30 Mg ha^?1 wet weight every third year) and a combination of both (OMI) were compared to a non‐P‐fertilized control (C) in 2015 and 2016. The test site was a long‐term field experiment on a Stagnic Cambisol in Rostock (NE Germany). Soil microbial biomass P (P_mic) and soil enzyme activities involved in P mobilization (phosphatases and ß‐glucosidase), plant‐available P content (double lactate‐extract; P_DL), mycorrhizal colonization, shoot biomass, and shoot P concentrations were determined. P deficiency led to decreased P immobilization in microbial biomass, but the maize growth was not affected. TSP application alone promoted the P uptake by the microbial biomass but reduced the mycorrhizal colonization of maize compared to the control by more than one third. Biowaste compost increased soil enzyme activities in the P cycling, increased P_mic and slightly decreased the mycorrhizal colonization of maize. Addition of TSP to biowaste compost increased the content of P_DL in soil to the level of optimal plant supply. Single TSP supply decreased the ratio of P_DL:P_mic to 1:1 from about 4:1 in the control. Decreased plant‐benefits from mycorrhizal symbiosis were assumed from decreased mycorrhizal colonization of maize with TSP supply. The undesirable side effects of TSP supply on the microbial P cycling can be alleviated by the use of compost. Thus, it can be concluded that the plant‐availability of P from soil amendments is controlled by the amendment‐specific microbial P cycling and, likely, P transfer to plants.     

Attitudes of veterinary medical students and medical students toward collaborative learning: an experiment

This study measured the attitudes of 55 medical students and 30 veterinary medical students as they participated in an experiment of collaborative teaching and learning about basic surgical skills. Two parallel forms of an attitude questionnaire were developed, with three subscales: confidence in one's own surgical skill; collaboration with the other type of student; and inter-professional collaboration in general. These attitude scales were administered before and after an experiment involving the veterinary medical students teaching the medical students incision and exploratory laparoscopy in a laboratory setting using live rabbits. After the experiment, measures of the medical students' attitudes had increased significantly on all three subscales. Measures of the veterinary students' attitudes increased significantly on two subscales but declined on the subscale of inter-professional collaboration.     

Recovery of live immature cyathostome larvae from the faeces of horses by Baermann technique

It was demonstrated in the present study that a simple Baermann technique using disposable materials, was successful in detecting living, motile cyathostome larvae in the faeces of horses.     

New technology imperatives in medical education

A great deal of effort has been expended on trying to determine whether traditional instruction, online learning, or some combination of the two is of greater educational effectiveness.1, 2 This may be the wrong question. Rather than determining whether one delivery mechanism is superior to another, it is more important to choose the best method(s) of delivery to achieve specific educational objectives, taking into consideration the different learning styles and circumstances of the target audience. Although appropriate use of technology offers potential for improved learning, there are other compelling reasons to use technology in medical education, such as reaching a different audience or accessing unique expertise that would otherwise be unavailable. This article explores the ramifications of three important drivers of technology adoption for medical education: (1) public access to medical knowledge on the Internet; (2) change in what constitutes medical knowledge; and (3) the impending shortage of educators. Some approaches are proposed, including veterinary examples, to the challenges presented by these changes.     

Spontaneous aortic dissecting hematoma in two dogs.

This report describes 2 cases of spontaneous aortic dissecting hematoma in young Border Collie and Border Collie crossbred dogs. Histology was performed in one of the cases involving an unusual splitting of the elastin present within the wall of the aorta, consistent with elastin dysplasia as described in Marfan syndrome in humans. The first case involved a young purebred Border Collie that died suddenly and the second case involved a Border Collie crossbred dog that died after a 1-month history of seizures. Gross lesions included pericardial tamponade with dissection of the ascending aorta in the former case and thoracic cavity hemorrhage, mediastinal hematoma, and aortic dissection in the latter. Histologic lesions in the case of the Border Collie crossbred dog included a dissecting hematoma of the ascending aorta with elastin dysplasia and right axillary arterial intimal proliferation.