Laboratory Animals最新文献

This narrative review summarizes and synthesizes the current literature regarding the comparative anatomy of pigs and humans, focusing on organ systems commonly involved in abdominal transplantation with the aim of supporting the safe and effective use of porcine models in preclinical studies. It also integrates practical insights from experimental surgery to highlight key considerations in perioperative care and surgical technique in porcine models. Pigs demonstrate substantial anatomical and physiological similarities to humans, making them ideal large-animal models for transplantation research. The recent surge in reports concerning clinical porcine xenotransplantation underscores the increasing importance of comprehending this comparative anatomy in the forthcoming years. However, critical species-specific anatomical differences particularly involving the gastrointestinal tract, hepatobiliary system, genitourinary tract and vascular structures require careful understanding to avoid surgical complications. Proper handling, perioperative care and awareness of porcine-specific stress responses and arrhythmias susceptibility are also essential to prevent premature animal loss. A thorough understanding therefore of porcine comparative anatomy is essential for transplant researchers conducting large animal surgery. Such knowledge improves experimental outcomes, supports adherence to the 3Rs (Replacement, Reduction and Refinement) and enhances the translational value of porcine models in transplantation research.

Anastomotic leakage following intestinal surgery in a murine Roux-en-Y gastric bypass (RYGB) model is usually fatal. Carprofen, a commonly used non-steroidal anti-inflammatory drug (NSAID) for postoperative analgesia in rodents, has been linked to negative effects on intestinal wound healing. The postoperative use of the non-opioid analgesic metamizole in this setting is rare. Here, we compared the potential effects of carprofen and metamizole on intestinal anastomotic healing in a murine RYGB model in order to optimize perioperative care in this animal model. A total of 38 mice underwent RYGB surgery as part of an in-house surgical training programme and received either carprofen (n = 17) or metamizole (n = 21) postoperatively. Within three postoperative days, anastomotic leakage occurred in 82% of carprofen-treated mice (14 of 17), mainly at the lower jejunal anastomosis (n = 12). The incidence of anastomotic leakage in the metamizole group was remarkably lower, occurring in four of 21 mice (19%) during the same period with three cases at the lower and one at the upper anastomosis. This is the first study demonstrating the detrimental effect of carprofen on jejunal anastomotic healing in a murine RYGB model. These findings underscore the critical importance of selecting appropriate analgesics for intestinal anastomosis surgery.

Better animal welfare is essential for better animal-based science. Poor welfare induces stress (and vice versa), which in turn can affect or even severely confound research results. To ensure the validity of scientific results, those who work with laboratory animals must take responsibility for their care and welfare. A harm-benefit analysis can be used to weigh the welfare and quality of life of animals in scientific studies against the resulting benefits to other animals or humans, provided that animal welfare can be validly assessed. This review considers the identification and characterisation of stress by physiological, hormonal, immunological and behavioural measures and by assessment of the physical condition of the animal. It addresses controllability, predictability, chronicity, duration and severity, and the intrinsic and extrinsic factors that modulate animal behaviour and coping mechanisms in response to stress. EU Directive 2010/63 requires procedures to be classified as mild, moderate or severe. However, as long as some researchers use purely subjective assessments without a supporting structure and reference scales, or no assessment method at all, these terms may have limited practical value. The challenge is to understand the state of the animal from the information available. Welfare assessment tools can be used to demonstrate the true impact of research procedures and their refinement to protect animal welfare. If any doubt exists about the harm-benefit evaluation of the experiment then the welfare of the animal should take priority.

Transcranial direct current stimulation (tDCS) for painless, non-invasive brain stimulation is a promising approach to enhance recovery after stroke. However, the precise molecular and cellular mechanisms underlying the effects of tDCS remain unclear, impeding its use in humans and necessitating research in experimental animals. Unlike humans, who receive tDCS fully awake, experimental models of tDCS have so far been conducted under anaesthesia to ensure the immobility required by currently available experimental setups. The use of anaesthesia may, however, confound results, decreasing their translational value. To address this problem, we developed a refined method enabling tDCS in awake and freely moving mice. A tube attached to the skull contains the stimulation electrode, whose position can be adapted flexibly to the target brain region; the reference electrode is implanted subcutaneously at the contralateral chest. Here, we report n = 135 awake mice that underwent tDCS in their home cage for up to 15 minutes per session over 10 consecutive days. None of those animals showed any adverse effects, neither regarding their general wellbeing, body weight, and behavioural activity, nor in ex vivo histology and immunohistochemistry. We suggest using this refined approach in future experimental studies of neuropsychological disorders.

No systematic procedures exist to ensure that differences in animal sensory capacities are accounted for in experimental design and ethical review processes. This oversight can compromise both scientific validity and animal welfare. This review presents three practical methodologies to address this gap: incorporation of specialist expertise through consultation frameworks, voluntary certification schemes modeled on Open Science practices, and mandatory sensory capacity review integrated into existing ethics committee processes. We provide a concrete tool-a sensory modality survey-that can be implemented by institutional review committees to evaluate sensory considerations in research proposals systematically. These approaches align with the 3Rs principles by enhancing experimental refinement and potentially reducing animal use through improved study design.

Antimicrobial resistance (AMR) is a major global threat to human health, animal welfare and sustainable development. Whilst resistance can arise naturally, inappropriate antimicrobial exposure accelerates its emergence. Recognizing this risk, international One Health initiatives emphasize reducing antimicrobial use, especially of drugs considered critical for human medicine. Much of the evidence guiding these efforts comes from food-producing and companion animals, but antimicrobial use in laboratory animals, particularly rodents, remains poorly described. To address this gap, we surveyed all veterinarians certified by the American College of Laboratory Animal Medicine in the United States (921) and Canada (10). A total of 157 veterinarians completed the survey, resulting in a 16.9% overall response rate. The response rate was 16.6% for participants in the United States and 40.0% for those in Canada. Despite a strong response, the small number of eligible veterinarians restricts data extrapolation in the Canadian context. Survey results showed that antimicrobial use is common and routine in rodent vivaria. Overall, 91.7% of respondents reported regular antimicrobial use. Applications included both clinical treatment and research purposes such as induction of microbiome dysbiosis, prophylaxis in immunocompromised rodents and gene induction. Reported drug classes included fluoroquinolones and third-generation cephalosporins, with some use of glycopeptides and carbapenems, all considered critically important to human health. Disposal practices often involved release into sewerage or landfill without inactivation, raising environmental concerns. These findings suggest that antimicrobial use in laboratory rodents may represent an underrecognized contributor to AMR and highlight the importance of targeted stewardship.

A continuing professional development (CPD) process should be implemented in all organisations involved in animal research to ensure professionals stay up to date with scientific advancements, best practices and regulations regarding animal welfare and laboratory animal science. These recommendations advocate for a lean and transparent CPD process to maintain the competence of professionals performing functions, roles and tasks outlined in Directive 2010/63/EU throughout a professional's career. CPD starts after initial training and once individual competence has been achieved. The first step involves creating a CPD portfolio, which the 'Person(s) Responsible for Training and Competence' reviews regularly to ensure it aligns with the professional's personal development plan (PDP). A structured portfolio is proposed for tracking and assessing CPD activities, enabling monitoring. We recommend this monitoring in cycles of up to 5 years.This document discusses the various types and formats of CPD activities, the minimum CPD requirements for professionals and the essential information that CPD certificates should include. This will be pivotal when developing a common framework for assessing CPD activities across institutions. To conclude, a harmonised CPD strategy that incorporates planning and record-keeping will facilitate mutual recognition and mobility of personnel. Moreover, promoting high-quality CPD will help motivate and reward staff while fostering a culture of care.

The thyroid gland's proper function is essential for controlling the metabolism, which varies to some extent between the sexes, thus maintaining the homeostasis. This research aimed to investigate differences in the histological structure and number of mast cells in the thyroid gland of male and female rats, and to establish whether there is a correlation between the levels of thyroid-stimulating hormone (TSH) and the activation index (Ia), which quantifies the functional activity of the gland based on histological parameters. Thyroid glands of 20 Wistar rats were analyzed morphometrically and stereologically to determine follicle size, distribution, and volume density of the epithelium, colloid, and connective tissue. Male thyroid glands had more small and medium follicles and a higher volume density of epithelium, while female thyroid glands had more large follicles and a higher volume density of connective tissue. The volume density of colloid was not significantly different between the sexes. The histological structure of the thyroid glands in both groups was in accordance with the measured TSH levels. The correlation between TSH serum levels and Ia were established in both sexes. Both the TSH serum levels and Ia were lower in females compared to males. A higher number of mast cells was noted in the connective tissue of female thyroid glands, compared to those of males, but this difference was not significant. The results of this study indicate that there are differences in the histological structure of male and female rat thyroid glands and that Ia can be used as a reliable complementary parameter for assessment of thyroid gland function.

The EU Directive 2010/63 on the protection of animals used for scientific purposes, as well as the Swiss Animal Welfare Legislation, demand monitoring and documentation of specific aspects of an animal experiment, including welfare-related issues and the (retrospective) assessment of the severity of the procedures that the animals underwent. A score sheet is an efficient tool for the evaluation of the burden of an animal during an experiment and, if properly designed and used, helps adhere to the 3Rs principle. It must be adapted to the specifics of each experiment and explicitly conceived for it. Several score sheet examples have been published; however, some contain fundamental flaws or are designed for specific settings only, requiring modifications to fit other experimental designs. This paper suggests an eight-step procedure to design a score sheet that can be adapted to any animal species and experimental conditions.

An approximately 7.5-month-old female Sprague Dawley rat (Rattus norvegicus) housed in a research facility presented for skin lesions including multifocal crusting and hypotrichosis. On presentation the research rat was mildly underconditioned with a distended abdomen and later developed small-bowel diarrhea. Abdominal ultrasound demonstrated diffusely thickened intestinal segments, and veterinary staff palpated a linear intra-abdominal mass. The rat was unresponsive to supportive care, and the rat was euthanized and necropsied. An elongate pink-tan mesenteric mass and severe, diffuse dilation and thickening of the small intestine were observed. Histopathology revealed mild to severe inflammation in most tissues with an abundance of eosinophils and eosinophilic granulomas in the abdominal lymph nodes. Clinical and histopathological findings are similar to hypereosinophilic syndromes (HES) described in a variety of species, including humans. Previous reports of HES in rats are limited to descriptions in rat strain Matsumoto Eosinophilia Shinshu (MES), which has been used as a model of human HES. Unlike MES rats, the rat in this report had diarrhea as well as eosinophilic infiltrates in the skin and heart, all of which are commonly described in human cases of HES.