Animal mortality

About: Animal mortality is a research topic. Over the lifetime, 526 publications have been published within this topic receiving 14887 citations.

Taxonomy and geographic distribution of potential toxic cyanobacterial strains in Morocco

Abstract: In Morocco, poisoning events of fish, aquatic birds and livestock have been observed in some reservoirs and shallow lakes. In all cases, the reasons for animal mortality reasons have not been confirmed and the toxic cyanobacteria strains that were abundant in these water bodies have been suggested as their cause. Since 1994, the authors started taxonomic, ecological and toxicological studies by collecting samples from various lakes reservoirs and ponds. The results show that more than 18 out of 26 lakes reservoirs used for human water supply contained at least one species of planktonic cyanobacteria, where the genus Microcystis was dominant (Microcystis aeruginosa f. aeruginosa, M. aeruginosa f. flos-aquae, M. ichthyoblabe, M. pulverea f. delicatissima) and was associated with Oscillatoria, Planktothrix, Anabaena, Aphanizomenon, Phormidium and other genera. Taxonomic studies shows that among more than 150 cyanobacteria taxa identified in Moroccan freshwater ecosystems, 35 are potentially toxic. For several species, the toxicity of both natural blooms and isolated strains lyophilized material was confirmed by mouse bioassay and the microcystins content evaluated by the Enzyme-linked immunosorbent assay (ELISA). A map of geographic distribution of Microcystis strains inventoried in moroccan water bodies is presented.

Mechanistic relationships between hepatic genotoxicity and carcinogenicity in male B6C3F1 mice treated with polycyclic aromatic hydrocarbon mixtures

Abstract: The genotoxicity of a complex mixture [neutral fraction (NF)] from a wood preserving waste and reconstituted mixture (RM) mimicking the NF with seven major polycyclic aromatic hydrocarbons (PAHs) and benzo(a)pyrene (BaP) was investigated by determining DNA adducts and tumor incidence in male B6C3F1 mice exposed to three different doses of the chemical mixtures. The peak values of DNA adducts were observed after 24 h, and the highest levels of PAH–DNA adducts were exhibited in mice administered NF + BaP, and the highest tumor incidence and mortality were also observed in this group. DNA adduct levels after 1, 7, or 21 days were significantly correlated with animal mortality and incidence of total tumors including liver, lung, and forestomach. However, only hepatic DNA adducts after 7 days significantly correlated with liver tumor incidence. Most proteins involved in DNA repair including ATM, pATR, Chk1, pChk1, DNA PKcs, XRCC1, FANCD2, Ku80, Mre11, and Brca2 were significantly lower in liver tumor tissue compared to non-tumor tissue. Expressions of proteins involved in apoptosis and cell cycle regulation were also significantly different in tumor versus non-tumor tissues, and it is possible that PAH-induced changes in these gene products are important for tumor development and growth.

Dabigatran versus warfarin after mechanical mitral valve replacement in the swine model

Abstract: Background: Mechanical heart valve replacement is an absolute indication for anticoagulation. We report our experience comparing dabigatran to warfarin as thromboembolic prophylaxis after mechanical mitral valve replacement in the swine model. Methods: Nineteen swine underwent mitral valve replacement with a regulatory approved, 27 mm mechanical valve. Two control groups consisted of three animals receiving no anticoagulation and five animals receiving warfarin (5 mg once a day [QD], adjusted to maintain international normalized ratio [INR] from 2.0 to 2.5). The experimental group consisted of 11 animals receiving dabigatran (20 mg/kg twice a day [BID]). The study period was 90 days. The primary outcome was animal mortality; secondary outcomes included presence of thrombus and bleeding complications. Results: The experimental group had four full-term survivors (40.0%); there were no full-term survivors in either control group. The average length of survival was 50.3 days in the experimental group ...

Birds and Roads: Reduced Transit for Smaller Species over Roads within an Urban Environment

Abstract: Roads provide humans with a means of mobility between destinations, be it for transportation of goods and services or as a means of connecting with others. However, roads are also known to contribute towards a number of deleterious landscape processes, such as habitat destruction and fragmentation, pollution (e.g. chemical, noise and light) and animal mortality. Few studies however have investigated their effects on avifauna. We investigated the influence of road width on movements of nearby bird assemblages in Australia by comparing crossing counts of four species guilds and sizes over roads of varying widths in Southern Brisbane. In addition, we also sought to determine the association of seasonality with species crossing richness and abundance. Species guild affiliations were based on definitions from previous literature: small forest dependent, large forest dependent, honeyeater and urban tolerant; whereas body size classifications were arbitrarily defined: small (30cm). Road sites were selected based on their vegetation likeness, both within and between sites, and this was assessed using the Specht classification system. We detected strong, negative correlations between road width and forest species richness, crossing species richness and species crossing abundance. In particular, analysis of species guild classifications revealed species richness and crossing likelihoods of the small forest dependent guild to be consistently lower than those of large forest dependent, honeyeater and urban tolerant guilds. Analysis of species by body size classification yielded similar outcomes: small birds were consistently less likely to be present nearby and cross over roads of all widths compared to medium and large birds. We believe gap permeability, particularly changes in vegetation structure and complexity that may restrict a species ability to access to the gap, as well as competition and predation, play an important role in determining species presence and crossing likelihood. Dense vegetation is known to benefit smaller species due to the provision of foraging resources and shelter from larger, more aggressive species.

Surgical method for virally mediated gene delivery to the mouse inner ear through the round window membrane.

Abstract: Gene therapy, used to achieve functional recovery from sensorineural deafness, promises to grant better understanding of the underlying molecular and genetic mechanisms that contribute to hearing loss. Introduction of vectors into the inner ear must be done in a way that widely distributes the agent throughout the cochlea while minimizing injury to the existing structures. This manuscript describes a post-auricular surgical approach that can be used for mouse cochlear therapy using molecular, pharmacologic, and viral delivery to mice postnatal day 10 and older via the round window membrane (RWM). This surgical approach enables rapid and direct delivery into the scala tympani while minimizing blood loss and avoiding animal mortality. This technique involves negligible or no damage to essential structures of the inner and middle ear as well as neck muscles while wholly preserving hearing. To demonstrate the efficacy of this surgical technique, the vesicular glutamate transporter 3 knockout (VGLUT3 KO) mice will be used as an example of a mouse model of congenital deafness that recovers hearing after delivery of VGLUT3 to the inner ear using an adeno-associated virus (AAV-1).