Laboratory Animals最新文献

This document provides assessment criteria for evaluation of each of the Learning Outcomes of the Modules specified (in addition to the Core Modules) for those designing procedures and projects in the Education and Training Framework guidance document by the European Commission and endorsed by the Member States Competent Authorities. This Working Group was tasked to produce these criteria by the Education & Training Platform for Laboratory Animal Science, which was funded by the European Commission to this aim. The assessment criteria address knowledge and skills (including critical thinking) expected to be acquired during education and training of persons preparing to design research procedures and projects using animals under the scope of Directive 2010/63/EU. Recognizing the diversity of expertise and experiences of those being educated and trained, we provide two levels of attainment, an ideal response and one that would be acceptable for each Learning Outcome. The balance between ideal and acceptable could be decided by the particular course providers and/or assessors, according to their local requirements. We envisage that the use of these assessment criteria by training providers and accrediting or approving bodies will help harmonize the education and training for those who will design procedures and projects using animals for scientific purposes. In Europe, this may also contribute to mutual recognition of training, and facilitate free movement of scientists.

To carry out research with genetically modified animals, their genotype has to be assessed. A standard protocol to obtain required tissue samples from zebrafish is finclipping. However, some studies reported considerable stress induced by this protocol. We therefore assessed ventilation as a read-out for stress in zebrafish that underwent finclipping during routine genotyping in our fish facility. Our analysis could not confirm a strong increase of ventilation as had been previously reported. Instead, handled zebrafish showed ventilation rates in the range of controls that remained in their holding tanks. Additionally, we detected a slight reduction of ventilation rates up to an hour after anaesthesia in zebrafish treated with tricaine only, suggesting a prolonged protecting effect by this anaesthetic.

One of the favored options for generating complex transgenic laboratory mice is through in-house breeding and management strategies. One consideration in the management of these colonies is how the animals' environment may affect reproductive success. Several aspects of the microenvironment can be controlled or manipulated, including cage type, bedding, enrichment, diet, and temperature and humidity. This study sought to evaluate reproductive outcomes for C57BL/6J mice that were randomly assigned to one of two different bedding types: paper based or corncob bedding. Our hypothesis was there would be no significant difference in reproductive outcomes between the two bedding types. A total of 10 males and 10 females were paired at 45 days of age. Animals were allowed to breed for 15 consecutive weeks. Cages were checked daily for the presence of pups and a pup count was performed at 7 days of age. Weaning occurred at 20 or 21 days of age, at which time a final pup count, pup weight, and sex were recorded. All litters born and pups weaned in the 15-week timeframe were used for data analysis. Statistical analysis compared cannibalization between the two groups and the results showed no statistical difference between groups (p > 0.05). Other parameters analyzed included average litter size, average weaning weight, and number of litters per group. All pups counted at Day 7 survived to weaning age in both groups. We concluded that both bedding types produced similar success regarding breeding fecundity in C57BL/6J mice.

Outbred stocks of mice are widely used in pre-clinical research as these animals possess a diversified genetic background when compared with inbred strains of mice. It is crucial to assess particular alterations in the physiological and functional profiles of laboratory animals using haematological and biochemical indicators. These values can also differ between laboratories because they are influenced by many different factors. We aimed to provide normal values and reference intervals for selected haematology and biochemistry analytes of 570 ICR mice at three different ages: 6-8 weeks, 10-14 weeks and 6-9 months. Reference values were calculated by non-parametric methods. For comparisons between sexes, the independent-sample t-test and Mann-Whitney test were employed, and analysis of variance was used for age differences. The findings of the study revealed age-related declines in haemoglobin concentration, haematocrit, mean corpuscular volume and mean corpuscular haemoglobin concentrations. Mice aged 6-9 months had statistically higher platelet counts in their blood than mice of other ages. The white blood cell count had a significant age effect and progressively decreased with age. As mice get older, the percentage of neutrophils, monocytes and basophils increases, but the percentage of lymphocytes decreases. For the biochemical values, age-related significant differences in glucose, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and albumin concentrations were found. It was also found that creatinine concentrations were comparable across all age ranges. The values presented in the present work can be used as a reference to interpret clinical pathology data for other studies and to evaluate health status.

As a step towards implementing non-aversive handling techniques at a big mouse breeding facility in Germany, tunnel handling was introduced in a breeding unit comprising three inbred mouse strains. To assess whether tunnel handling would be feasible for the animal technicians in their everyday work and beneficial for the mice when being handled during weekly cage change only, the behaviour of tunnel- and tail-handled animals of both sexes was examined before, during and after the handling events over a period of nine weeks. Moreover, the time expenditure was compared between both handling techniques. It was possible to use the tunnel in all three mouse strains. However, the impact of the handling techniques on the behavioural parameters investigated in the present study were strain-specific. All behavioural parameters suggested that NZW mice benefited the most from tunnel handling. The results obtained from Hello Kitty and WNK mice were ambiguous, which may suggest that a brief handling session during the cage clean may have not been sufficient to habituate them to the process of handling. It took the animal technicians approximately 3 seconds longer per mouse when using a tunnel. The strain-specific results should encourage researchers to share their experiences with non-aversive handling techniques in different mouse strains, for example, along with their research articles.

Although pulmonary adenomas have been reported in ICR mice, spontaneous adenomas have not been reported in mice aged ≤10 weeks. Here, we report a well-circumscribed nodule (1 mm × 1 mm) in the peripheral lesion of the left lateral lobe of a 10-week-old male ICR mouse. Histopathologic evaluation revealed a well-demarcated nodule compressing the surrounding tissue. The neoplastic cells were polygonal with indistinct cellular borders, round/oval nuclei and abundant cytoplasm. These characteristics led to the diagnosis of type II cell-derived bronchioloalveolar adenoma. Given that they are generally observed in aged laboratory animals, this case represents a rare manifestation of a spontaneous tumor in young laboratory mice before puberty.

Urine collection can be challenging in studies involving small rodents like mice, as the actual methods of collection are anxiogenic and constrain animal welfare while having high variability in the volume of urine collected. To improve the current methods and eventually reduce the impact on the well-being of mice, we developed an innovative 3D-printed urine collection device (UCD). This two-compartment UCD is shaped to fit in classical husbandry cages and allows urine collection by spontaneous urination from two mice housed in their own cage without cross-contamination while enabling potential social interactions. We used our UCD to study the evolution of urinary parameters related to renal functions in a model of antibody-mediated chronic kidney disease. Overall, we report here a time-saving and affordable method for urine collection providing a large amount of uncontaminated urine and which we believe may improve animal welfare in comparison with other methods.

Blinding and randomisation are important methods for increasing the robustness of pre-clinical studies, as incomplete or improper implementation thereof is recognised as a source of bias. Randomisation ensures that any known and unknown covariates introducing bias are randomly distributed over the experimental groups. Thereby, differences between the experimental groups that might otherwise have contributed to false positive or -negative results are diminished. Methods for randomisation range from simple randomisation (e.g. rolling a dice) to advanced randomisation strategies involving the use of specialised software. Blinding on the other hand ensures that researchers are unaware of group allocation during the preparation, execution and acquisition and/or the analysis of the data. This minimises the risk of unintentional influences resulting in bias. Methods for blinding require strong protocols and a team approach. In this review, we outline methods for randomisation and blinding and give practical tips on how to implement them, with a focus on animal studies.

Statistically based experimental designs have been available for over a century. However, many preclinical researchers are completely unaware of these methods, and the success of experiments is usually equated only with 'p < 0.05'. By contrast, a well-thought-out experimental design strategy provides data with evidentiary and scientific value. A value-based strategy requires implementation of statistical design principles coupled with basic project management techniques. This article outlines the three phases of a value-based design strategy: proper framing of the research question, statistically based operationalisation through careful selection and structuring of appropriate inputs, and incorporation of methods that minimise bias and process variation. Appropriate study design increases study validity and the evidentiary strength of the results, reduces animal numbers, and reduces waste from noninformative experiments. Statistically based experimental design is thus a key component of the 'Reduction' pillar of the 3R (Replacement, Reduction, Refinement) principles for ethical animal research.

Cage effects: some researchers worry about them, some don't, and some aren't even aware of them. When statistical analyses do not account for cage effects, there is real reason to worry. Regardless of researchers' worries or lack thereof, all researchers should be aware of how cage effects can affect the results. The "how" depends, in part, on the experimental design. Here, I (a) define cage effects; (b) illustrate a completely randomized design (CRD) often used in animal experiments; (c) explain how statistical significance is artificially inflated when cage effects are ignored and (d) give guidance on proper analyses and on how to increase statistical power in CRDs.