Multicentric mast cell tumors in a horse

Abstract: A 6‐year‐old female Rocky Mountain horse was presented for evaluation of draining tracts and distal limb subcutaneous edema on the left front and left hind limbs that had been present for 2 weeks. Direct smears of fluid collected by fine‐needle aspiration of subcutaneous fluid from both limbs were highly cellular with a predominance of eosinophils accompanied by numerous, moderately atypical, variably granulated mast cells. The cytologic diagnosis was mast cell tumor (MCT) with prominent eosinophilic infiltration with a differential diagnosis of eosinophilic granuloma. Histologic evaluation of surgical biopsies of lesions from both limbs was performed on sections stained with H&E, toluidine blue, and Luna stains. The histologic diagnosis was MCT, and staining with toluidine blue and Luna stains confirmed the presence of mast cells and eosinophils, respectively. In addition, the mast cells strongly expressed CD117. This is the first reported case of cutaneous mast cell neoplasia in a horse in which primary presenting complaints were draining tracts and distal limb subcutaneous edema involving multiple limbs. This case illustrates the utility of staining for CD117 expression in combination with traditional stains, such as toluidine blue and Luna, in differentiating MCTs from other eosinophilic lesions in horses.     

Attempts to determine the effects of forest cover on stream flow by direct hydrological measurements in Los Negros,Bolivia

Underlying many payments for watershed services (PWS) schemes in tropical montane forest contexts is the assumption of a direct positive relationship between forest cover and dry season stream flow. We developed a low cost research program to assess the forest cover-stream flow relationship in the Los Negros watershed in eastern Bolivia. We asked three questions: (1) can watersheds that are similar enough to undertake paired catchment studies be identified using only simple parameters such as size, aspect and geographic proximity; (2) can a functioning locally based hydrological monitoring system be set up for less than $10 000 by training local farmers to collect hydrological data, and (3) can such data be used to improve the functioning of a PWS initiative? A land use map of the upper Los Negros valley was created from a 2005 Landsat image and a digital elevation model used to calculate physical and hydrological properties of 10 sub-watersheds. Farmers measured stream flow rates in these sub-watersheds from 2005 to 2008 and maintained 10 automatic rain gauges. We found no relationship between forest cover and stream flow. This may indicate that no such relationship exists, but could also reflect the short period of the study, the low quality of the data, and the fact that the sub-watersheds had relatively similar forest coverage (54–76%). We conclude that (1) watersheds can be identified as “similar-enough-for-analysis” using the criteria of size, aspect and proximity without undertaking further research, (2) a useful hydrological monitoring system can be developed for <$10,000 and (3) although our local farmers did not collect sufficiently high quality data to fully explore the forest/water relationship in Los Negros, with improvements in methodologies, low cost, locally based monitoring has the potential to be an important component of future PWS initiatives. We recommend that stream discharge should be calculated directly; only the most locally relevant hydrological criteria, rather than scientifically complete criteria, should be monitored; locally based monitoring must be institutionalized to reduce staff turnover and hydrological monitoring must be embedded within a context that makes it socially acceptable.     

Community Changes and Growth in Small Cities: Resident Perceptions of Growth in Brandon,Manitoba, Canada

While research on rural depopulation and urbanization to large cities has dominated the literature for decades, small city growth has been largely ignored. Yet, small cities are important to the regional systems in which they are located, including serving as centres to their rural surround. This paper is concerned about growth and change in small cities. Using Brandon, Manitoba as an example, citizen perceptions of a range of specific aspects of city growth are analyzed. The study is based on a household postal survey conducted in May and June 2010 in which 2,500 randomly selected households in Brandon, Manitoba received questionnaires. The results are based on the 518 useable, completed questionnaires that were returned. Differences in perceptions of the pace of change in a range of aspects of development were found based on income, age, educational attainment, employment status, and home ownership. No differences were found based on gender. The paper concludes with comments about how city governments need to be aware of citizen perceptions when pursuing and managing development. The paper also illustrated the importance of citizen perceptions in understanding the pace and direction of change in small cities.     

Dye injection for predicting pesticide movement in micro-irrigated polyethylene film mulch beds

A new method is described for tracing water movement in polyethylene film covered soil beds. Dye was delivered via a drip tape micro-irrigation system which was placed in the bed as the soil beds were shaped and covered with polyethylene film. The dye was injected into the system and irrigated with water for 4-24 h at 0.41-1.38 bar (41-138 kPa) pressure depending on the experiment. The dye appeared as blue circles on the soil surface within 20 min of injection and produced a three-dimensional pattern in the soil profile. Injection-irrigation-pressure scenarios were evaluated by measuring dye movement directly below and between emitters by sliding fabricated blades vertically into the bed at the desired examination point and excavating the soil away from the blade. The dye typically produced a U shape on the face of the bed and the area was calculated for each of these exposed faces. The area increased as the length of irrigation and water pressure increased. Interrupted irrigation (pulsing) scenarios did not alter the calculated areas encompassed by the dye compared to uninterrupted irrigation scenarios. The blue dye provided a direct, inexpensive and easy method of visualizing water movement in soil beds. This information will be used to optimize application of emulsifiable plant-care products in polyethylene film mulch beds.     

Type of smear may influence thrombopoietic cell counts in the bone marrow of clinically healthy dogs

BACKGROUND: The expected number of thrombopoietic cells in normal canine bone marrow is poorly defined and there is no consensus on the most appropriate way to prepare cytologic smears to evaluate these cells nor on the optimum method for their quantification. OBJECTIVE: The purpose of this study was to determine total and differential counts of thrombopoietic cells in the bone marrow of clinically healthy Beagle dogs by comparing 4 different smear types and bone marrow core biopsies. METHODS: Twenty-two clinically healthy, male Beagle dogs, 10 to 12 months old, were used in the study. Following bone marrow aspiration and core biopsy from the iliac crest, Giemsa-stained smears were prepared by 4 techniques: drop-squash, particle-squash, buffy coat, and fat-layer smears. Thrombopoietic cells were counted in up to 100 low-power fields (LPF, X10 objective) in the aspiration smears and in all possible high-power fields (HPF, X40 objective) in H&E-stained biopsy sections. RESULTS: Mean total thrombopoietic cell counts were 2.76 cells/LPF (drop-squash), 1.55 cells/LPF (particle-squash), 8.05 cells/LPF (buffy coat), and 3.08 cells/LPF (fat-layer). Core biopsies yielded 5.31 cells/HPF but frequently failed to provide interpretable specimens. There was a significant difference in cell counts among the 4 smear types (P <.001). Based on evaluation of buffy coat smears, thrombopoietic cells included 1.23% megakaryoblasts, 8.77% promegakaryocytes, and 90% megakaryocytes, with a mean maturation index of 0.11. CONCLUSION: Thrombopoietic cell counts in canine bone marrow are influenced by the smear technique. Buffy coat and fat-layer smears may be useful to obtain cellular smears in hemodiluted or small aspirate samples.     

Prevalence of Shiga-toxigenic Escherichia coli O157:H7 in adult dairy cattle

OBJECTIVE: To describe shiga-toxigenic Escherichia coil O157:H7 (STEC O157:H7) fecal shedding prevalence, seasonal fecal shedding patterns, and site-specific prevalence from the oral cavity, skin, and feces of dairy cattle. DESIGN: Cross-sectional study. ANIMALS: Adult dairy cattle from 13 herds in Louisiana. PROCEDURE: Samples were cultured for STEC O157 by use of sensitive and specific techniques, including selective broth enrichment, immunomagnetic separation, monoclonal antibody-based O:H enzyme immunoassay serotyping, and polymerase chain reaction virulence gene characterization. Point estimates and 95% confidence intervals were calculated for fecal shedding prevalence as well as site-specific prevalence from the oral cavity, skin, and feces. Logistic regression was used to assess seasonal variation and differences at various stages of lactation with respect to fecal shedding of STEC O157 in cattle sampled longitudinally. RESULTS: Summer prevalence in herds in = 13) was 38.5%, with a cow-level prevalence of 6.5%. Among positive herds, prevalence ranged from 3% to 34.6%. Samples from 3 of 5 herds sampled quarterly over 1 year yielded positive results for STEC O157. In herds with STEC O157, an increase in cow-level prevalence was detected during spring (13.3%) and summer (10.5%), compared with values for fall and winter. Site-specific prevalences of STEC O157:H7 from oral cavity, skin, and fecal samples were 0%, 0.7%, and 25.2%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Our data indicated that STEC O157:H7 was commonly isolated from dairy cows in Louisiana, seasonally shed, and isolated from the skin surface but not the oral cavity of cows.     

Molecular weapons against agricultural vulnerability and the war on terror

The multiple reports in this issue of the Journal from the Agenda for Action conference, coupled with the analysis by the National Academy of Sciences, the National Research Council, and the Auditor General (UK) on bioterror preparedness and homeland security, highlight the immediate need for rapid disease detection and advanced diagnostic capabilities to protect the public health, animal agriculture, and the numerous associated economies in the United States. In response to the potentially devastating consequences that could arise, there is an acute need for rapid detection of a variety of the lethal foreign animal diseases, such as foot-and-mouth disease virus (FMDV), highly pathogenic strains of avian influenza, classical swine fever, rinderpest, exotic Newcastle disease virus (END), and domestic, vesicular look-alike diseases that include bluetongue, epizootic hemorrhagic disease, vesicular stomatitis, bovine herpes IBR, contagious ecthyma, bovine herpes mammilitis virus, vesicular exanthema, malignant catarrhal fever, and papular stomatitis. Some striking advances are occurring in the creation of rapid technology, including microfluidics, robotics, miniaturization, and biostabilization that are quickly being applied to the development of rapid microbial detection assays. These are now providing important weapons to combat this agricultural vulnerability.