Showing papers on "Animal mortality published in 2008"

Quantifying the evidence for ecological synergies

Abstract: There is increasing concern that multiple drivers of ecological change will interact synergistically to accelerate biodiversity loss. However, the prevalence and magnitude of these interactions remain one of the largest uncertainties in projections of future ecological change. We address this uncertainty by performing a meta-analysis of 112 published factorial experiments that evaluated the impacts of multiple stressors on animal mortality in freshwater, marine and terrestrial communities. We found that, on average, mortalities from the combined action of two stressors were not synergistic and this result was consistent across studies investigating different stressors, study organisms and life-history stages. Furthermore, only one-third of relevant experiments displayed truly synergistic effects, which does not support the prevailing ecological paradigm that synergies are rampant. However, in more than three-quarters of relevant experiments, the outcome of multiple stressor interactions was non-additive (i.e. synergies or antagonisms), suggesting that ecological surprises may be more common than simple additive effects.

Heat Shock Protein 20 Interacting With Phosphorylated Akt Reduces Doxorubicin-Triggered Oxidative Stress and Cardiotoxicity

Abstract: Doxorubicin (DOX) is a widely used antitumor drug, but its application is limited because of its cardiotoxic side effects. Heat shock protein (Hsp)20 has been recently shown to protect cardiomyocytes against apoptosis, induced by ischemia/reperfusion injury or by prolonged beta-agonist stimulation. However, it is not clear whether Hsp20 would exert similar protective effects against DOX-induced cardiac injury. Actually, DOX treatment was associated with downregulation of Hsp20 in the heart. To elucidate the role of Hsp20 in DOX-triggered cardiac toxicity, Hsp20 was first overexpressed ex vivo by adenovirus-mediated gene delivery. Increased Hsp20 levels conferred higher resistance to DOX-induced cell death, compared to green fluorescent protein control. Furthermore, cardiac-specific overexpression of Hsp20 in vivo significantly ameliorated acute DOX-triggered cardiomyocyte apoptosis and animal mortality. Hsp20 transgenic mice also showed improved cardiac function and prolonged survival after chronic administration of DOX. The mechanisms underlying these beneficial effects were associated with preserved Akt phosphorylation/activity and attenuation of DOX-induced oxidative stress. Coimmunoprecipitation studies revealed an interaction between Hsp20 and phosphorylated Akt. Accordingly, BAD phosphorylation was preserved, and cleaved caspase-3 was decreased in DOX-treated Hsp20 transgenic hearts, consistent with the antiapoptotic effects of Hsp20. Parallel ex vivo experiments showed that either infection with a dominant-negative Akt adenovirus or preincubation of cardiomyocytes with the phosphatidylinositol 3-kinase inhibitors significantly attenuated the protective effects of Hsp20. Taken together, our findings indicate that overexpression of Hsp20 inhibits DOX-triggered cardiac injury, and these beneficial effects appear to be dependent on Akt activation. Thus, Hsp20 may constitute a new therapeutic target in ameliorating the cardiotoxic effects of DOX treatment in cancer patients.

Response of carnivores to existing highway culverts and underpasses: implications for road planning and mitigation

Abstract: Roads with high traffic volumes are a source of animal mortality, can disrupt normal animal movements and dispersal, and may represent a potentially serious threat to wildlife population stability and viability. Retrofitting existing structures built for other purposes (e.g., drainage culverts or small below-grade access roads) to facilitate wildlife crossing by animals and to reduce mortality may be expensive if modifications to the existing structures themselves were involved. However, the environmental context surrounding these structures may influence the willingness of animals to cross, and management of some of these attributes may enhance the attractiveness of these structures. Culverts and underpasses are two common structures along roads in Portugal. We quantified the response of small and medium-sized carnivores to the presence of both types of existing passages by determining: (1) frequency of use; (2) whether use differed by type of passage, and if so; (3) by examining if associated environmental attributes might explain the differences observed. We surveyed 57 different passages along 252 km of highway with a total sampling effort of 2,330 passage trap-days. The mean passage rate for carnivores combined was 0.7 complete passages per crossing structure per day. Crossings by weasel, polecat, otter, and wildcat were infrequent or absent. Red fox, badger, genet and Egyptian mongoose used the crossing structures regularly and without obvious preference; stone marten preferred underpasses. Regression analyses showed the frequency of use by carnivores varied with structural, landscape, road-related features, and human disturbance with 17 of 26 (65%) attributes being significant. Larger passages with vegetation close to the passage entrances, favorable habitat in the surrounding area, and low disturbance by humans were important key features to regular use by the guild of species studied. Mitigation planning in areas with ecological significance for carnivores will be beneficial. Structural attributes and human disturbances are more difficult or expensive to change, even though related significantly to crossing use. Management of vegetation at passage entrances and restricting human use near passages in carnivore suitable areas may substantially improve crossing attractiveness for the guild of carnivore species.

Effects of long-term dietary intake of magnesium on oxidative stress, apoptosis and ageing in rat liver

Abstract: In the present study, we investigated the effect of long-term dietary Mg intake on the rate of oxidative stress, apoptosis and ageing in rat livers. To address this issue, rats were fed diets containing either a moderately deficient (0.15 g Mg/kg diet), a standard (0.8 g Mg/kg diet) or a high (3.2 g Mg/kg diet) Mg dose for two years. It is noteworthy that a higher percentage of animal mortality was observed in the lowest Mg diet, as compared to the other groups. Oxidative stress and antioxidant status were evaluated by measuring different enzyme activities, among which glutathione peroxidase activity was significantly reduced when Mg content was decreased in the diet. Moreover, we obtained an activation of caspase-3 and a higher lipid peroxidation in the Mg-deficient group, as compared to the Mg standard group, while no changes in Mg-supplemented group were observed, in accordance with our previously published data in primary cultures of rat hepatocytes (Martin et al., J Nutr 2003). Telomere shortening was measured in rat livers, as a marker of ageing. We found that telomere length was decreased in old animals, as compared to young animals confirming that telomere shortening correlated well with ageing events. Moreover, in old animals, we obtained a decrease of telomere length in the Mg-deficient group, as compared to the other groups. Taken together, our results show that a long-term chronic Mg deficiency led to oxidative stress, apoptosis and an acceleration of ageing in rat livers.

West Nile virus and hemoparasites in captive snowy owls (Bubo scandiacus)--management strategies to optimize survival.

Abstract: In August 2005, 2 members of a group of 6 captive snowy owls (Bubo scandiacus) in central Saskatchewan died of West Nile virus infection. One of these owls and 3 of the remaining owls had significant numbers of circulating hemoparasites. Management strategies are suggested to reduce morbidity and mortality.

An assessment of animal repellents in the management of vehicle-macropod collisions in New South Wales

Abstract: Collisions between animals and motor vehicles are frequent and often result in animal mortality. In Australia, macropods are regular victims of these collisions. This has serious implications for animal welfare and conservation as well as aesthetics and tourism. Collisions with large animals and secondary collisions caused by the presence of animals on road easements, can lead to serious personal injury and property damage. A range of mitigative measures to prevent animal-vehicle collisions exists, but no single measure can be fully effective and the efficacy of many mitigation measures remains untested. An integrated management approach, employing many mitigative techniques is required to reduce vehicle-animal collisions. Repellents have recently been identified as a potential mitigative measure for reducing vehicle-animal collisions. The aim of this study was to identify the potential role of repellents in reducing macropod-vehicle collisions in New South Wales. This required the identification and assessment of potential repellents since research investigating repellents in an Australian context is scant. Macropus rufogriseus banksianus was selected as a test species for this research as a high abundance of this species exists in southeastern Australia and it is a common victim of roadkill in New South Wales. Preliminary screening trials of four potential macropod repellents highlighted the utility of two of the substances: Plant Plus, a synthetic compound based on the chemistry of dog urine; and a formulation consisting of chicken eggs. Feeding by M. rufogriseus banksianus was significantly reduced when these substances were applied near feed trays. Modest results were also detected for ?3-isopentenyl methyl sulfide (a constituent of fox urine), while a commercial animal repellent (SCATREPLACE3 Bird and Animal Repellent) was ineffective in altering feeding by M. rufogriseus banksianus.;A barrier trial conducted with the two most successful repellents indicated that Plant Plus was a more effective macropod repellent then the egg formulation. Plant Plus displayed qualities of an area repellent and elicited a stronger response from M. rufogriseus banksianus when compared to the egg formulation. Further captive trials determined that the habituation of response to Plant Plus by M. rufogriseus banksianus was minimal after six weeks of constant exposure and Plant Plus retained repellent properties after exposure to ambient environmental conditions for at least ten weeks. Field trials to establish the effectiveness of Plant Plus with free ranging macropods (M. rufogriseus banksianus and M. giganteus) were unsuccessful due to methodological limitations stemming from high background variance in observed responses, equipment failure and site disturbance from outside influences. The potential role of Plant Plus as a repellent for managing macropod-vehicle collisions was highlighted by the captive trials. However, several factors requiring further research were identified. This included assessing the repellent abilities of Plant Plus in the field and further defining the properties of Plant Plus with captive trials. The effects of Plant Plus on non-target species and an assessment of potential environmental impacts also requires attention. Research assessing the potential role of repellents in other management contexts in Australia would be beneficial and the identification and assessment of repellents for other species should proceed. However, in the context of assessing repellents for use in the management of vehicle-macropod collisions, immediate focus should concentrate on extending the research to assess the effects of Plant Plus with other species of large macropod, and assessing if Plant Plus can reduce the numbers of macropods in road easements.

Mammary cancer immunodeficiency type animal model and method for preparing the same

Abstract: The present invention relates to the technical field of medical evaluation and detection. The invention discloses a method to prepare a breast cancer immunodeficiency mouse model, which establishes a human breast cancer cell Nod-SCID mouse model firstly and successfully at home and abroad by regular injection of estrogen preparations to the immunodeficiency mice and transplant of the breast cancer cells after thereof. The breast cancer immunodeficiency mouse model constructed by the invention has short construction period, high tumor formation rate, low animal mortality, simple and easy construction method and low cost, and thus is an ideal breast cancer immunotherapy animal model.

Micotoxicose em avestruz Struthio camelus. Relato de caso

Abstract: Micotoxins can cause toxic effects, teratogenics, mutagenics, carcinogenics and imunedepression. The first clinical signals are weakness and inapetence. The liver presents increase in volume and hepatic fibrosis. The micotoxins cause economic losses due to animal mortality. An ostrich farm, 150 birds, of varied ages, presented several cases of animals with motor incoordination, appetite loss and apathy. After four deaths, specialized help was seeked. Necropsy of the dead animals showed liver lesions and visual observation indicated ration with "mould", suspect of micotoxity. Sending of the materials to the laboratory (liver and ration), comproved the presence of fungus and liver lesions. All the birds received, orally,, amino acids and polivitaminics. The most effective form to prevent micotoxins and their harmful effect to an ostrich farm is to control the development of fungus in the ration of the birds. The risk factors are presented by aflatoxin contamination in the rations an other food ingredients.

Benzene-Induced Hematotoxicity and Myelotoxicity by Short-Term Repeated Oral Administration in Mice

Abstract: Exposure dose of benzene has been postulated to be critical to induce hemopoietic malignancies. By long-term inhalation of benzene, 300 ppm has been shown to be the dose that induces high frequency of leukemia with the least animal mortality in the mouse. With regard to the benzene studies, determination of the oral dose that will be corresponding to the critical inhalation dose could be important to design the experimental protocol based on oral administration. Based on the background data such as the respiratory volume, absorption factor, and so on, we, therefore, calculated a potential oral dose that is expected to be corresponding to 300 ppm of inhalation dose. The determined oral dose was 150 ㎎/㎏ B.W. We then evaluated, using C57BL/6 mice, the toxic effects of benzene on the peripheral blood and the bone marrow (BM) by oral administration of the selected dose once a day for 1 and 2 weeks. Leukocyte, red blood cell number and BM cellularity were respectively decreased to 47.8%, 72.3% and 66.7% of the respective control level by 1-week oral administration of benzene, and to 30.8%, 60.2% and 80.2% by 2-week oral administration. Changes in the leukocyte numbers were mainly due to the marked decrease of lymphocytes. According to the results, the changes of the parameters examined were generally corresponding to the change levels by the 2-week inhalation. In conclusion, the selected dose, 150 ㎎/㎏ B.W., was a reliable dose corresponding to the 300 ppm benzene inhalation, which was verified by in vivo mouse study.

Atherosclerosis vulnerable plaque animal model and method for establishing the same

Abstract: The invention relates to an atherosclerosis vulnerable plaque animal pattern and a building method thereof. The atherosclerosis vulnerable plaque animal pattern is characterized by the following steps: an experimental vessel is separated by a surgery method, blood at two ends of the vessel is blocked by a vessel clamp, the blood in the vessel is drained, and then liquid nitrogen is injected in the vessel for the endothelium freezing injury operation, high fat diet is combined for feeding, at last, the endothelium freezing injury operation is performed again for exciting the vulnerable plaque, and the atherosclerosis vulnerable plaque animal pattern is successfully built through the verification of results of pathology, electron microscope, immunohistochemistry, RT-PCR, Western blot, and the like. The animal pattern can better simulate the characteristics of the vulnerable plaque of the human, and has the advantages of simple pattern making operation, low pattern making cost, short pattern forming time, little operation hurt, serious narrow degree, high plaque breaking rate, low animal mortality rate, easy duplication, high controllability, and the like, thereby being very favorable to the medicine development of the plaque stabilizing therapy and the experimentation of the cardiovascular and cerebrovascular diseases, and having popularization and application values.

Effects of Plant Water-Soluble Polysaccharides on the Production of Immunoglobulins E and G1 by Lymphocytes of Mice Sensitized with Ovalbumin

Abstract: Were studied the effects of water-soluble plant polysaccharides isolated from pharmacopoeic raw material on anaphylactic shock and production of IgE and IgG1 by lymphocytes from mice immunized with ovalbumin. Course treatment with polysaccharides from coltsfoot, sweet flag, clover, Artemisia, marigold, and elecampane reduced animal mortality after induction of anaphylactic shock. In addition, injection of these substances reduced serum concentrations of IgE and IgG1. These substances can be regarded as promising agents for the treatment of IgE-dependent diseases (atopic dermatitis, asthma, atopic rhinitis, urticaria, food allergies, etc.).

Improvements in Environmental Quality and Animal Productivity with Advanced Manure Treatment

Abstract: To be permitted, new swine waste management systems in North Carolina need to meet the strict performance standards of an environmentally superior technology (EST). These technologies must be able to substantially remove nutrients, heavy metals, emissions of ammonia, odors, and pathogens. Our objective was to demonstrate, at full-scale, a second generation treatment system for swine waste that can achieve the high treatment performance standards of an EST, yet it is four times more economical than earlier versions. The system combines solid-liquid separation, biological ammonia treatment, and phosphorus removal and produces a deodorized and disinfected liquid effluent. The second generation system was installed full-scale in a 5,150-head finishing swine operation and demonstrated under steady-state conditions and cold and warm weather. The system removed 98% of the suspended solids, 100% of biological oxygen demand, 97% of the ammonia, 94% of the phosphorus, 99% of the copper and zinc, 99.9% of the odor compounds, and reduced pathogens 4-logs (99.99%). Ammonia concentration in the air of the barns was significantly reduced, and animal health and productivity were enhanced. Compared to the traditional lagoon management, the animal mortality decreased 57%, the rate of daily weight gain increased 11%, and the rate of feed conversion into meat improved 5.4% with the new manure management system. These findings showed that two or more simple processes can be combined into a practical system to achieve the strict EST performance standards and that these cleaner technologies can have significantly positive impacts on animal productivity and the environment.

Effect of Radioprotector Indralin on the Course of Acute GVH Disease

Abstract: The effect of radioprotector indralin on the graft-versus-host reaction was studied on the model of acute GVH disease induced in mice by intraperitoneal transplantation of 40×106 semiallogenic splenocytes. The effect was evaluated by animal mortality from GVH disease. Recipients were male F1(CBA × C57Bl/6) mice exposed to 7 Gy 24 h before transplantation. Donors were male C57Bl/6 mice. Indralin, intraperitoneally injected in a dose of 100 mg/kg 5 min after irradiation attenuated the severity of GVH disease. It eliminated phase I of acute GVH reaction and shifted to the right the dynamics of mortality. Estimated time of 50% mortality (LT50) was prolonged by more than 4 days (the parameter increased by 31.1%). Two (5.7%) animals recovered from acute GVH disease, while all controls died. Indralin treatment after irradiation resulted in a 30% increase in survival of exposed mice.