There are several animal models routinely used for study of the spinal fusion process and animal selection largely depends on the scientific question to be answered. This review outlines the advantages and disadvantages of various animal models used to study spinal fusion and describes the New Zealand White (NSW) rabbit which is the most popular preclinical model to study spinal fusion. We outline critical steps required in planning and performing spinal fusion surgery in this model. This includes determination of the required animal number to obtain statistical significance, an outline of appropriate technique for posterolateral fusion and other components of completing a study. As advances in drug delivery move forward and our understanding of the cascade of gene expression occurring during the fusion process grows, performing and interpreting preclinical animal models will be vital to validating new therapies to enhance spinal fusion.
Infection with Anaplasma phagocytophilum in white-footed mice results in partial protection against reinfection with the same agent. However, humans and domestic animals may be sequentially exposed to different isolates of the agent circulating in the same or adjacent foci. We investigated whether immune response to a tick-borne infection with A. phagocytophilum provides protection against homologous and heterologous challenges. BALB/c mice were infected with one of the two sympatric isolates of A. phagocytophilum via tick bite and challenged 16 weeks later by Ixodes scapularis nymphs infected with either the same or the alternative isolate. As controls, groups of infected mice were challenged by uninfected ticks to confirm an absence of reactivation of the original infection or groups of naive mice were fed upon by ticks from cohorts used for an infectious challenge. Xenodiagnostic I. scapularis larvae were fed upon each mouse at 14 and 21 days postchallenge (PCH) and tested for the presence of A. phagocytophilum as freshly molted nymphs. Blood samples for quantitative PCR were collected at 7, 14, 21, and 70 days PCH. Serum samples were collected weekly to monitor development of immune response. The proportion of infected animals, levels of bacteremia, and the prevalence of infection in xenodiagnostic ticks were higher in groups of control mice exposed to A. phagocytophilum for the first time than in mice reinfected with either homologous or heterologous isolates. The presence of antibodies against A. phagocytophilum did not protect mice from a challenge with either homologous or heterologous isolates, however the ensuing reinfection was significantly milder and of a shorter duration than the first infection with either isolate.
The experiment successfully demonstrated controlled movement of the substance. This technique can significantly change treatment of brain diseases because substances: i) may be moved in a controlled, predictable way - exponentially increasing therapeutic interactions with the target; and ii) no longer need to conform to constraints dictated by the BBB (molecular mass < 500 d; lipophilic), thereby increasing potential number of usable substances.
As the use of zebrafish (Danio rerio) as a research model continues to rise, so too will the shipping and sharing of zebrafish strains across collaborating institutions. If done incorrectly, shipping can result in significant mortality, welfare concerns, and loss of valuable resources for researchers and research institutions. Here we introduce a novel method to track temperatures of zebrafish containers during shipping and show that internal packaging temperatures are directly affected by the external temperatures. We used temperature logging Thermochron iButtons to track the temperatures of 2 packages containing adult zebrafish that were shipped overnight from Dallas, TX to Columbus, OH during winter following recommended fish shipping guidelines. We found that the external packaging of both boxes of fish were exposed to temperatures that had previously been shown to be lethal to zebrafish. However, internal temperatures and, more specifically, water temperature, stayed within 24.0 to 26.5 °C during shipment, resulting in 100% survival of adult zebrafish. This novel method of tracking packaging temperatures of live fish during shipping can help to inform fish health status on arrival.
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