Perioperative desmopressin prolongs survival in surgically treated bitches with mammary gland tumours: a pilot study

Desmopressin (1-deamino-8-d-arginine vasopressin, also known as DDAVP) is a safe haemostatic compound capable of inhibiting lymph node and lung metastasis in a mouse model of mammary tumour manipulation and surgical excision. The aim of this study was to test the efficacy and safety of perioperative DDAVP (1microg/kg) in surgically treated bitches with mammary gland tumours (MGT). Twenty-one, otherwise healthy, intact bitches, with malignant MGT stage III or IV were randomly allocated to DDAVP (n=11) or placebo (n=10) groups. En bloc mastectomy of the affected gland/s was performed. DDAVP had a significant beneficial effect on disease-free period (P<0.01) and overall survival time (P<0.05). No side effects were seen in any of the cases. Whatever the mechanism of action, it seems that DDAVP may have a novel use in cancer surgery to minimise spread or survival of residual malignant cells. Additional, large scale controlled trials are required to fully evaluate this adjuvant pharmacological protocol.     

Leiomyoma in the nasal cavity of a dog

A 7‐year‐old, 34‐kg, neutered male Labrador retriever was presented with a 1‐year history of intermittent sneezing with occasional left‐sided epistaxis. CT revealed a mass in the left nasal cavity. Histopathological analysis of rhinoscopy‐guided tissue biopsies was consistent with chronic necrotic and ulcerative rhinitis. Surgical debridement by ventral rhinotomy was subsequently performed and histopathological diagnosis was leiomyoma. Complete resolution of the nasal discharge and reduced sneezing frequency were observed after surgery. Fourteen months postoperatively, CT detected no regrowth of the mass.     

Effect of Dimethyl Sulfoxide on Cell Cycle Synchronization of Goldfish Caudal Fin Derived Fibroblasts Cells

Several studies have previously been conducted regarding cell cycle synchronization in mammalian somatic cells. However, limited work has been performed on the control of cell cycle stages in the somatic cells of fish. The aim of this study was to determine the cell cycle arresting effects of several dimethyl sulfoxide (DMSO) concentrations for different times on different cell cycle stages of goldfish caudal fin‐derived fibroblasts. Results demonstrated that the cycling cells or control group (68.29%) yields significantly higher (p < 0.05) arrest in G0/G1 phase compared with the group treated for 24 h with different concentrations (0.5%, 1.0% or 1.5%) of DMSO (64.88%, 65.70%, 64.22% respectively). The cell cycle synchronization in the treatment of cells with 1.0% DMSO at 48 h (81.14%) was significantly higher than that in the groups treated for 24 h (76.82%) and the control group (77.90%). Observations showed that treatment of DMSO resulted in an increase in the proportion of cells at G0/G1 phase for 48 h of culture. However, high levels of apoptotic cells can be detected after 48 h of culture treated with 1% concentration of DMSO.     

Providing management options to control corn mouse (Calomys musculinus) reservoir populations using a cohort structured model

We evaluate several management options for Calomys musculinus populations through the formulation and validation of a cohort structured model. Initially, a basic model was constructed and validated using field population data. Next, the model was altered to allow us to evaluate different management options. In general, basic model results were in agreement with field data, demonstrating that this model would be useful in describing aspects of corn mouse population dynamics. Restricting control measures to when mouse numbers reach high levels would be inadequate, because population numbers tend to increase in size after some years. In contrast, reducing vegetation cover in spring was more effective in reducing field population abundances. Despite some limitations, the model could be useful for evaluating the relationships between population dynamics and some biotic or physical environmental variables, and thus ensure more efficient use of resources in integrated pest management.     

A non-invasive crop ideotype to reduce invasive potential

Summary In plant breeding programs, qualitative and quantitative traits confer market value and, thus, constitute the basis for developing breeding criteria during crop domestication. Some traits such as high male/female fertility are advantageous in the wild and could enable the evolution of cultivated crops into invasive weeds. Other traits, e.g. sterility, are not expected to confer invasiveness. To date there has been very limited involvement in invasion risk assessment by plant breeders. Thus, in this paper we propose that trait-based selection of potential crop species be coupled with species design in the creation of a “non-invasive crop ideotype” as an avenue to reduce invasiveness during domestication. The non-invasive crop ideotype embodies the ideal characteristics for a crop to excel in cultivated environment(s) but minimizes the likelihood it will establish and spread in non-cultivated environments, constituting the underlying foundation for all breeding objectives, choice(s) of breeding methodologies, and propagation techniques for non-invasive crop release. Using ornamental (floriculture) horticultural crops as an example, we identify 10 traits to be used individually or in combination to reduce invasiveness while retaining commercial value: reduced genetic variation in propagules, slowed growth rates, non-flowering, elimination of asexual propagules, lack of pollinator rewards, non-shattering seed, non-fleshy fruits, lack of seed germination, sterility, and programmed death (apotopsis). A non-invasive crop ideotype would constitute the underlying foundation for all breeding objectives, the choice(s) of breeding methodologies, and propagation technique(s). The ideotype should be flexible and should adjust to species- and crop-specific traits to account for the intended use. For example, development of sterile cultivars may have negligible effects in reducing invasiveness if the crops spread vegetatively. A non-invasive crop ideotype may increase the direct participation of plant breeders, who are the professionals directly involved in the collection, development and release of new crops, in reducing the invasive potential of ornamental crops. Future research is required to determine the feasibility of incorporating each trait into various crops, use of classical or molecular techniques for creation of non-invasive crops, trait stability (lack of genotype × environment interaction over years and locations), consumer acceptance, and long-term viability.     

玉米轮回选择群体的ASI增益

利用两个群体各二个轮回选择周期的材料，研究了ＡＳＩ在盖膜与露地以及直播与移栽条件下的反应。结果表明：１．为缩短ＡＳＩ而实行的轮回选择，可获得显著的选择增益；２．在缩短ＡＳＩ的同时，散粉期和抽丝期也相应缩短，并且抽丝期缩短更多；３．无论在灌水还是在不分胁迫条件下，直播株的ＡＳＩ总是极显著地比移栽株短；４．各轮回选择群体的ＡＳＩ，灌水的都比实行干旱胁迫的缩短。     

Selection strategies to reduce invasive potential in introduced plants

Summary The crop domestication process is examined from plant collection to product release for various junctures at which deliberate breeding, selection, and crop transformation may occur to prevent invasive potential. Four primary juncture opportunities for research on techniques and development of selection procedures for non-invasiveness include: The Plant Exploration Phase, Initial Trial Phase, Fast-Tracking Phase, Selection and Improvement Phase. Avoiding the collection of germplasm that appears weedy during plant exploration is an obvious, yet cost-effective way to reduce invasiveness in a selection program. During initial trials, comparing genotypic differences in traits related to invasiveness should allow plant breeders to identify cultivars that pose the least risk before undertaking comprehensive field trials. Genotypes with high commercial value, considered candidates for “fast-tracking”, should only advance quickly to product release if they exhibit a minimum level of invasive risk, i.e., species with low dispersal capacity and that have little potential to impact ecosystems. Fast-growing taxa, those with high seed production, ones likely to be rapidly dispersed by wind, animals, water or people, and others that can significantly alter nutrient or light levels are examples of species that should not be “fast-tracked”. Field trials that have typically been used to evaluate performance of genotypes across a broad range of cultivated environmental conditions need to be expanded to adequately evaluate invasive potential during the selection and improvement phase. Testing in environments that mimic conditions where introductions could naturalize is crucial, as are evaluations of competition with indigenous species. The time and resource investment needed to conduct adequate trials at this stage is potentially very high; more research is needed to ensure the trials conducted are targeting important information gaps for decision-making. Additional research is also needed to develop modeling approaches that effectively forecast long-term dynamics of introductions and to assist in developing field testing priorities. Minimizing invasive potential could significantly reduce introductions that cause inadvertent damage to landscapes and ecosystems. The strategy proposed here will require further development, especially in the context of understanding and assessing risks of pre- and post-release strategies for minimizing damage from invasive species. Scientific Paper No. 051210156 of the Department of Horticultural Science.     

Estimation of the Isozymatic Genetic Variability of a Spanish A vena sativa Germplasm Collection

An analysis of Spanish land races of Avena sativa from the Germplasm Bank of the I.N.I.A. was carried out using starch gel electrophoresis. Samples of 15 seedlings per accession were used for estimating the intra- and interpopulational genetic variability. Electrophoretic analyses were performed with crude extracts from 15 day-old seedling leaflets by means of eight isozymatic systems representing a total of ten genetic loci. Two systems were mono-morphic in all the accessions, while the other six showed polymorphism both within and between populations. Intrapopulational variability was particularly high in this collection, only 16 out of the 137 accessions being uniform for all the isozyme systems. Thus the material was shown to represent a high potential of genetic variability for breeding programmes.     

Potomac horse fever in Ontario: Clinical,geographic, and diagnostic aspects

Clinical findings, geographic locations, laboratory diagnoses, and culture isolation of Neorickettsia spp. in Potomac horse fever (PHF) cases diagnosed in Ontario between 2015 and 2019 are described. Forty-six confirmed PHF cases occurred from late June to early September. Of 41 horses admitted to the Ontario Veterinary College, 28 (68%) survived and 13 (32%) were euthanized due to poor prognosis or financial constraints. Most cases were in southern Ontario along the Canada-USA border. Blood and fecal samples from 43 suspect PHF cases were submitted to 2 laboratories for polymerase chain reaction (PCR) testing for Neorickettsia risticii. Agreement between both laboratories for detection of N. risticii DNA was excellent for feces [κ = 0.932, 95% confidence interval (CI): 0.80 to 1], and fair for blood samples (κ = 0.494, 95% CI: 0.13 to 0.85). Neorickettia spp. were isolated from 16 of 41 (39%) blood samples. DNA analysis confirmed 14 isolates were N. risticii and 2 were N. findlayensis, a novel species of Neorickettsia recently demonstrated to cause PHF.     

Changes in mononuclear peripheral blood cells in cattle with foot-and-mouth disease

The percentages and absolute numbers of mononuclear peripheral blood cells (MNC) were studied in vaccinated (Vac) and non-vaccinated (control) cattle, challenged with foot-and-mouth disease virus (FMDV). All Vac cattle but none of the controls resisted challenge. Cell populations were studied immediately before and one week after challenge, by direct and indirect immunofluorescence, using polyclonal and monoclonal antibodies against different bovine markers. Total B-lymphocytes, as assessed with polyclonal anti-IgG(H+L) antisera, as well as total mononuclear cells, were normal before and after infection, and did not change in Vac or control groups. Before challenge Vac cattle had higher numbers of IL A-29⁺ (a putative marker for null cells or, alternatively, for γδ T-cells) than control cattle. After challenge, in control cattle, the number of total T-cells, BoT4-bearing (helper) T-cells and BoT8-bearing (cytotoxic/suppressor) T-cells were decreased, while IgM-bearing B-lymphocytes, as well as monocyte/macrophage cells were increased. The number of IL-A29-bearing T-cells did not change after infection in either group. After challenge, Vac cattle also showed increased numbers of IgM-bearing B-lymphocytes and monocyte/macrophage cells, whereas T-subpopulations did not change significantly.