Comparative medicine最新文献

General anesthesia induces a reversible loss of consciousness (LOC), a state that is characterized by the inability to feel pain. Identifying LOC in animals poses unique challenges, because the method most commonly used in humans, responding to questions, cannot be used in animals. For over a century, loss of righting reflex (LORR) has been used to assess LOC in animals. This is the only animal method that correlates directly with LOC in humans and has become the standard proxy measure used in research. However, the reporting of how LORR is assessed varies extensively. This systematic literature review examined the consistency and completeness of LORR methods used in rats and mice. The terms 'righting reflex,' 'anesthesia,' 'conscious,' 'rats,' 'mice,' and their derivatives were used to search 5 electronic databases. The abstracts of the 985 articles identified were screened for indications that the study assessed LORR in mice or rats. Full texts of selected articles were reviewed for LORR methodological completeness, with reported methods categorized by 1) animal placement method, 2) behavioral presence of righting reflex, 3) duration of LORR testing, 4) behavioral LORR, and 5) animal position for testing LORR. Only 22 papers reported on all 5 methodological categories. Of the 22 papers, 21 used unique LORR methodologies, with descriptions of LORR methods differing in at least one category as compared with all other studies. This variability indicates that even papers that included all 5 categories still had substantial differences in their methodological descriptions. These findings reveal substantial inconsistencies in LORR methodology and reporting in the biomedical literature likely compromising study replicability and data interpretation.

This corrects the article DOI: 10.30802/AALAS-CM-23-000037. When the above article was first published in the Vol 73 No 6 (December 2023) issue of Comparative Medicine, figure images were incorrectly associated with the figure legends. The correct version of this article has been reprinted in full in volume 74, issue 1 of the February issue of Comparative Medicine.The publisher apologizes for this error and any inconvenience caused.

Among several existing mouse models for hepatitis B virus (HBV) infection, the high-pressure hydrodynamic injection (HDI) method is frequently used in HBV research due to its economic advantages and ease of implementation. The use of the HDI method is influenced by factors such as mouse genetic background, age, sex, and the type of HBV plasmid used. This overview provides a multidimensional analysis and comparison of various factors that influence the effectiveness of the HBV mouse model established through HDI. The goal is to provide a summary of information for researchers who create HBV models in mice.

A detailed understanding of mosquito probing and ingestion behaviors is crucial in developing novel interventions to interrupt the transmission of important human and veterinary pathogens, but these behaviors are difficult to observe as the mouthparts are inserted into the skin of the host. Electropenetrography (EPG) allows indirect observation, recording, and quantification of probing and ingestion behaviors of arthropods by visualizing the electrical waveform associated with these behaviors. The study of mosquito probing and ingestion behaviors has been limited to the use of human hands as host, which is not suitable for pathogen transmission studies. Mouse models of mosquito-borne diseases are a widely used and indispensable tool in this research, but previous attempts to use direct current EPG to study mosquito probing behaviors on mice have been unsuccessful. Accordingly, the present study used alternating or direct current (AC-DC) EPG to observe the ingestion behaviors of adult Aedes aegypti mosquitoes on a mouse host in real time under BSL-2 containment conditions with enhanced BSL-3 practices. Our results show that waveform families previously identified during Ae. aegypti probing and ingestion on human hands were observed using 100 mV of AC at an input resistance (Ri) of 10⁷ Ohms (Ω) on CD1 mice. This work is a proof of concept for using mouse models for studying mosquito probing and ingestion behaviors with AC-DC EPG. In addition, these data show that the experimental setup used in these experiments is sufficient for conducting studies on mosquito probing and ingestion behaviors under BSL-2 containment conditions enhanced with BSL-3 practices. This work will serve as a foundation for using EPG to investigate the effects of pathogen infection on mosquito probing behaviors and to understand the real-time dynamics of pathogen transmission.

Rabbits can develop anemia due to serial phlebotomy or secondary to induced disease states. This study evaluated the effects of a single injection and three consecutive injections of erythropoietin in rabbits at 150 IU/kg and 1,000 IU/kg in order to determine whether these dosages produce a sustained increase in hematocrit. Analysis of CBC and chemistry parameters showed significant elevation in hematocrit one week after administration of 1,000 IU/kg erythropoietin for three consecutive days. These results indicate that this dosage regimen can increase hematocrit in apparently healthy, nonanemic rabbits for one week.

Depending on the strain of immunodeficient mice, Corynebacterium bovis infection can be asymptomatic or cause transient or prolonged skin disease. C. bovis infection of NOD. Cg- Prkdc^scid Il2rg^tm1Wjl /SzJ (NSG) mice results in clinical skin disease that progresses in severity. Amoxicillin metaphylaxic and prophylaxic therapy prevents transmission and infection of mice after exposure to C. bovis and inhibits the growth of C. bovis isolates at therapeutic doses that are clinically achievable in mice. Amoxicillin is not efficacious for treatment of transient clinical skin disease in athymic nude mice, but the efficacy of amoxicillin treatment has not previously been characterized in C. bovis -infected NSG mice. In the current study, NSG mice were treated with amoxicillin beginning at 5 wk after exposure to C. bovis, at which time they had well-established clinical signs of disease. Clinical signs were scored to assess disease progression, regression, and reappearance. Our results showed that amoxicillin treatment for 3 or 6 wk reduced the clinical scores of NSG mice with C. bovis -associated clinical disease. In addition, withdrawal of treatment led to the recurrence of clinical signs. Collectively, our data suggest that amoxicillin treatment is effective in alleviating the clinical signs associated with C. bovis infection for the duration of treatment in NSG mice. Clinical intervention with antibiotics for C. bovis -infected NSG mice can be an option for management of C. bovis -related clinical disease either before or during facility-wide remediation efforts.

Decreased appetite is a common clinical problem in captive rhesus macaques (Macaca mulatta). Mirtazapine, a tetracyclic antidepressant originally developed for humans, has shown promise as a safe and effective promoter of weight gain and appetite in several veterinary species including rhesus and cynomolgus macaques. Although mirtazapine is available as oral formulations, transdermal delivery in macaques with reduced appetite would allow quick, painless, topical application. Here we describe the pharmacokinetics of a single application of a widely available veterinary transdermal mirtazapine formulation in 6 rhesus macaques. A dose of 0.5 mg/kg of transdermal mirtazapine ointment that has proven to be effective in rhesus was applied to the caudal pinnae of 3 female and 3 male young adult macaques. Serum was collected at 0, 0.5, 1, 3, 6, 8, 12, 24, 36, 48, and 72 h after administration. Our data indicate transdermal mirtazapine is absorbed at a lower level in rhesus as compared with published values in domestic cats (rhesus peak serum concentration: 1.2 ± 0.3 ng/mL), while drug half-life is longer than that reported in cats (rhesus: 33 ± 7 h). Mirtazapine reaches peak plasma concentrations in rhesus at 16 ± 10 h after administration; our model indicates that up to 5 d of serial dosing may be necessary to reach steady state. Our preliminary data also suggest that sex differences may contribute to efficacy and/or indicate sex-based differences, as male macaques reached T_max more quickly than females (19 ± 2 h in females and 8 ± 3 h in males) and showed higher variation in half-life (33 ± 4 h in females and 34 ± 11 h in males). While previous work indicates clinical efficacy of the 0.5-mg/kg dosage in macaques, further investigation is warranted to determine if rhesus may benefit from higher recommended doses than companion animal species.

Animals have been used in research for over 2,000 y. From very crude experiments conducted by ancient scholars, animal research, as a science, was refined over hundreds of years to what we know it as today. However, the housing conditions of animals used for research did not improve significantly until less than 100 years ago when guidelines for housing research animals were first published. In addition, it was not until relatively recently that some extrinsic factors were recognized as a research variable, even when animals were housed under recommended guidelines. For example, temperature, humidity, light, noise, vibration, diet, water, caging, bedding, etc., can all potentially affect research using mice, contributing the inability of others to reproduce published findings. Consequently, these external factors should be carefully considered in the design, planning, and execution of animal experiments. In addition, as recommended by others, the housing and husbandry conditions of the animals should be described in detail in publications resulting from animal research to improve study reproducibility. Here, we briefly review some common, and less common, external factors that affect research in one of the most popular animal models, the mouse.