Experimental study of tuberculosis: From animal models to complex cell systems and organoids.

Tuberculosis (TB) is a devastating disease to mankind that has killed more people than any other infectious disease. Despite many efforts and successes from the scientific and health communities, the prospect of TB elimination remains distant. On the one hand, sustainable public health programs with affordable and broad implementation of anti-TB measures are needed. On the other hand, achieving TB elimination requires critical advances in three areas: vaccination, diagnosis, and treatment. It is also well accepted that succeeding in advancing these areas requires a deeper knowledge of host-pathogen interactions during infection, and for that, better experimental models are needed. Here, we review the potential and limitations of different experimental approaches used in TB research, focusing on animal and human-based cell culture models. We highlight the most recent advances in developing in vitro 3D models and introduce the potential of lung organoids as a new tool to study Mycobacterium tuberculosis infection.

Is it acceptable to use animals to model obese humans? A critical discussion of two arguments against the use of animals in obesity research.

Animal use in medical research is widely accepted on the basis that it may help to save human lives and improve their quality of life. Recently, however, objections have been made specifically to the use of animals in scientific investigation of human obesity. This paper discusses two arguments for the view that this form of animal use, unlike some other forms of animal-based medical research, cannot be defended. The first argument leans heavily on the notion that people themselves are responsible for developing obesity and so-called 'lifestyle' diseases; the second involves the claim that animal studies of obesity's causes and therapies distract attention from preventive efforts. Drawing on both empirical data and moral reasoning, we argue that the relevant attributions of responsibility and claims about distraction are not plausible, and that, therefore, there is no reason to single out the use of animals in obesity research as especially problematic.

Examining why ethics is taught to veterinary students: a qualitative study of veterinary educators' perspectives.

Although it is widely agreed that veterinary students need to be introduced to ethics, there is limited empirical research investigating the reasons why veterinary ethics is being taught. This study presents the first extensive investigation into the reasons for teaching veterinary ethics and reports data collected in semi-structured interviews with educators involved in teaching undergraduate veterinary ethics at three European schools: the University of Copenhagen, the University of Nottingham, and the Technical University of Lisbon (curricular year 2010-2011). The content of the interview transcripts were analyzed using Toulmin's argumentative model. Ten objectives in teaching veterinary ethics were identified, which can be grouped into four overarching themes: ethical awareness, ethical knowledge, ethical skills, and individual and professional qualities. These objectives include recognizing values and ethical viewpoints, identifying norms and regulations, developing skills of communication and decision making, and contributing to a professional identity. Whereas many of the objectives complement each other, there is tension between the view that ethics teaching should promote knowledge of professional rules and the view that ethics teaching should emphasize critical reasoning skills. The wide range of objectives and the possible tensions between them highlight the challenges faced by educators as they attempt to prioritize among these goals of ethics teaching within a crowded veterinary curriculum.

An Objective Structured Laboratory Animal Science Examination (OSLASE) to ensure researchers' professional competence in laboratory animal science.

The evaluation of the competence of personnel working with laboratory animals is currently a challenge. Directive 2010/63/EU establishes that staff must have demonstrated competence before they perform unsupervised work with living animals. Nevertheless, there is a lack of research into education and training in laboratory animal science, and the establishment of assessment strategies to confirm researchers' competence remains largely unaddressed.In this study, we analysed the implementation of a practical assessment strategy over three consecutive years (2018-2021) using the Objective Structured Laboratory Animal Science Exam (OSLASE) developed previously by us to assess professional competence. The interrater reliability (IRR) was determined based on the assessors' rating of candidates' performance at different OSLASE stations using weighted kappa (Kw) and percentage of agreement. Focus group interviews were conducted to access trainees' acceptability regarding the OSLASE.There was a moderate-to-good Kw for the majority of the scales' items (0.79 ± 0.20 ≤ Kw ≥ 0.45 ± 0.13). The percentages of agreement were also acceptable (≥75%) for all scale items but one. Trainees reported that the OSLASE had a positive impact on their engagement during practical training, and that it clarified the standards established for their performance and the skills that required improvement. These preliminary results illustrate how assessment strategies, such as the OSLASE, can be implemented in a manner that is useful for both assessors and trainees.Examen structuré objectif de science animale de laboratoire (OSASSE) pour assurer la compétence professionnelle des chercheurs en SAL.

Advancing the 3Rs: innovation, implementation, ethics and society.

The 3Rs principle of replacing, reducing and refining the use of animals in science has been gaining widespread support in the international research community and appears in transnational legislation such as the European Directive 2010/63/EU, a number of national legislative frameworks like in Switzerland and the UK, and other rules and guidance in place in countries around the world. At the same time, progress in technical and biomedical research, along with the changing status of animals in many societies, challenges the view of the 3Rs principle as a sufficient and effective approach to the moral challenges set by animal use in research. Given this growing awareness of our moral responsibilities to animals, the aim of this paper is to address the question: Can the 3Rs, as a policy instrument for science and research, still guide the morally acceptable use of animals for scientific purposes, and if so, how? The fact that the increased availability of alternatives to animal models has not correlated inversely with a decrease in the number of animals used in research has led to public and political calls for more radical action. However, a focus on the simple measure of total animal numbers distracts from the need for a more nuanced understanding of how the 3Rs principle can have a genuine influence as a guiding instrument in research and testing. Hence, we focus on three core dimensions of the 3Rs in contemporary research: (1) What scientific innovations are needed to advance the goals of the 3Rs? (2) What can be done to facilitate the implementation of existing and new 3R methods? (3) Do the 3Rs still offer an adequate ethical framework given the increasing social awareness of animal needs and human moral responsibilities? By answering these questions, we will identify core perspectives in the debate over the advancement of the 3Rs.

"The person in power told me to"-European PhD students' perspectives on guest authorship and good authorship practice.

Questionable authorship practices in scientific publishing are detrimental to research quality and management. The existing literature dealing with the prevalence, and perceptions, of such practices has focused on the medical sciences, and on experienced researchers. In contrast, this study investigated how younger researchers (PhD students) from across the faculties view fair authorship attribution, their experience with granting guest authorships to more powerful researchers and their reasons for doing so. Data for the study were collected in a survey of European PhD students. The final dataset included 1,336 participants from five European countries (Denmark, Hungary, Ireland, Portugal, and Switzerland) representing all major disciplines. Approximately three in ten reported that they had granted at least one guest authorship to "a person in power". Half of these indicated that they had done so because they had been told to do so by the person in power. Participants from the medical, natural and technical sciences were much more likely to state that they had granted a guest authorship than those from other faculties. We identified four general views about what is sufficient for co-authorship. There were two dominant views. The first (inclusive view) considered a broad range of contributions to merit co-authorship. The second (strongly writing-oriented) emphasised that co-authors must have written a piece of the manuscript text. The inclusive view dominated in the natural, technical, and medical sciences. Participants from other faculties were more evenly distributed between the inclusive and writing oriented view. Those with an inclusive view were most likely to indicate that they have granted a guest authorship. According to the experiences of our participants, questionable authorship practices are prevalent among early-career researchers, and they appear to be reinforced through a combination of coercive power relations and dominant norms in some research cultures, particularly in the natural, technical, and medical sciences.

Welfare assessment in transgenic pigs expressing green fluorescent protein (GFP).

Since large animal transgenesis has been successfully attempted for the first time about 25 years ago, the technology has been applied in various lines of transgenic pigs. Nevertheless one of the concerns with the technology--animal welfare--has not been approached through systematic assessment and statements regarding the welfare of transgenic pigs have been based on anecdotal observations during early stages of transgenic programs. The main aim of the present study was therefore to perform an extensive welfare assessment comparing heterozygous transgenic animals expressing GFP with wildtype animals along various stages of post natal development. The protocol used covered reproductory performance and behaviour in GFP and wildtype sows and general health and development, social behaviour, exploratory behaviour and emotionality in GFP and wildtype littermates from birth until an age of roughly 4 months. The absence of significant differences between GFP and wildtype animals in the parameters observed suggests that the transgenic animals in question are unlikely to suffer from deleterious effects of transgene expression on their welfare and thus support existing anecdotal observations of pigs expressing GFP as healthy. Although the results are not surprising in the light of previous experience, they give a more solid fundament to the evaluation of GFP expression as being relatively non-invasive in pigs. The present study may furthermore serve as starting point for researchers aiming at a systematic characterization of welfare relevant effects in the line of transgenic pigs they are working with.

"How sick must your mouse be? " - An analysis of the use of animal models in Huntington's disease research.

Refinement measures to improve animal welfare can ease the ethical dilemma between human benefit and animal harm in research with animal models of neurodegenerative diseases. To evaluate the potential for refinement, as well as its implementation in research, we analysed papers on murine models of Huntington's disease (HD) published between 1999 and 2009 (n = 233). Each study was classified according to a four-level severity scale, in terms of the disease stage that animals were allowed to reach, the execution of invasive procedures, and the implementation of refinement. Reports of ethical approval, and regulatory compliance in general, followed a clear rising trend over the years reviewed (p <0.001). However, the proportion of high-severity studies did not change over that period. Also, of the studies for which approval was reported (n = 120), 36% were attributed the highest severity level. The observed discrepancy between the rising motivation to affirm regulatory compliance, and the unaltered proportion of studies allowing animals to reach severely distressful stages, raises both ethical and methodological issues, which we discuss in this paper.

From Mating to Milk Access: A Review of Reproductive Vocal Communication in Mice.

Vocalisations play a central role in rodent communication, especially in reproduction related behaviours. In adult mice (Mus musculus) the emission of ultrasonic vocalisations (USVs) has been observed in courtship and mating behaviour, especially by males. These have been found to have distinctive individual signatures that influence female choice of mating partner. The most recent findings show that vocal communication also has a role in parental cooperation, in that female mice communicate with male partners in ultrasonic frequencies to induce paternal behaviour. Infant vocalisations form the other important part of reproductive vocal communication. Although born deaf, neonatal mice are capable of producing vocalisations since birth. As an altricial species, successful mother-infant communication is essential for survival, and these vocalisations are important modulators of maternal behaviour. Three main types of infant vocalisations have been identified and characterised. Most research has addressed pure USVs, related to stressful situations (e.g., cold, isolation, handling, presence of unfamiliar males or predators), which usually elicit maternal search and retrieval. In addition, broad-band spectrum signals, emitted post-partum during cleaning of foetal membranes, inhibit biting and injury by adults and "wriggling calls," emitted during suckling, release maternal behaviour (such as licking). Several variables have been identified to modulate vocalisations in mice, including individual characteristics such as strain/genotype, age, sex, and experimental factors such as pharmacological compounds and social context. In recent years, there has been a big increase in the knowledge about the characteristics of vocal communication in rodents due to recent technological advances as well as a growing interest from the neuroscience community. Vocalisation analysis has become an essential tool for phenotyping and evaluating emotional states. In this review, we will (i) provide a comprehensive summary of the current knowledge on mouse reproductive vocal communication and (ii) discuss the most recent findings in order to provide a broad overview on this topic.

Anesthesia Overdose Versus Rapid Cooling for Euthanasia of Adult Zebrafish.

The rapid increase in zebrafish use needs to be accompanied by research into the refinement of procedures. The European (EU) Directive lists three possible euthanasia methods for fish: anesthetic overdose, electrical stunning, and concussion. However, for small fish such as zebrafish, concussion and electrical stunning are difficult to perform, leaving anesthetic overdose as the most used method. Our aim was to test the efficacy and side effects of anesthesia overdose using different anesthetics and the rapid cooling method to euthanize adult zebrafish. Adult mixed-sex AB zebrafish were randomly assigned to: 250 mg/L MS222; 20 mg/L propofol +100 mg/L lidocaine; 6 mg/L etomidate; 50 mg/L clove oil; and rapid cooling (water at 2°C-4°C). Two minutes after opercular movement ceased, animals were transferred into clean water for 20 min and recovery assessed, or decapitated and used for biochemical analysis of the gills, muscle, liver, and brain; for the histological analysis of the gills and muscle; or for the assessment of cortisol levels. No animal recovered; rapid cooling was the quickest and etomidate overdose was the slowest method to cease the opercular movements. There were no major differences between euthanasia methods regarding the biochemical or histological data. Cortisol levels were higher in the rapid cooling group, but only when compared with the propofol/lidocaine group. The use of a physical method of euthanasia, such as rapid cooling, is essential when chemicals, such as anesthetics, may interfere with postmortem analyses. Although anesthetic overdose can be used without major effects on the analyses conducted in this work, rapid cooling can be another option with the advantage of being simple to administer, easily available, affordable, and very quick; this decreases the potential duration of suffering, being more humane. Therefore, a change in EU legislation should be considered to include additional humane options for euthanasia, such as rapid cooling, for zebrafish and other small tropical fish.

Non-Invasive Assessment of Mild Stress-Induced Hyperthermia by Infrared Thermography in Laboratory Mice.

Stress-induced hyperthermia (SIH) is a physiological response to acute stressors in mammals, shown as an increase in core body temperature, with redirection of blood flow from the periphery to vital organs. Typical temperature assessment methods for rodents are invasive and can themselves elicit SIH, affecting the readout. Infrared thermography (IRT) is a promising non-invasive alternative, if shown to accurately identify and quantify SIH. We used in-house developed software ThermoLabAnimal 2.0 to automatically detect and segment different body regions, to assess mean body (Tbody) and mean tail (Ttail) surface temperatures by IRT, along with temperature (Tsc) assessed by reading of subcutaneously implanted PIT-tags, during handling-induced stress of pair-housed C57BL/6J and BALB/cByJ mice of both sexes (N = 68). SIH was assessed during 10 days of daily handling (DH) performed twice per day, weekly voluntary interaction tests (VIT) and an elevated plus maze (EPM) at the end. To assess the discrimination value of IRT, we compared SIH between tail-picked and tunnel-handled animals, and between mice receiving an anxiolytic drug or vehicle prior to the EPM. During a 30 to 60 second stress exposure, Tsc and Tbody increased significantly (p < 0.001), while Ttail (p < 0.01) decreased. We did not find handling-related differences. Within each cage, mice tested last consistently showed significantly higher (p < 0.001) Tsc and Tbody and lower (p < 0.001) Ttail than mice tested first, possibly due to higher anticipatory stress in the latter. Diazepam-treated mice showed lower Tbody and Tsc, consistent with reduced anxiety. In conclusion, our results suggest that IRT can identify and quantify stress in mice, either as a stand-alone parameter or complementary to other methods.

Behavioural Aversion and Cortisol Level Assessment When Adult Zebrafish Are Exposed to Different Anaesthetics.

The use of zebrafish (Danio rerio) as an animal model is growing and occurs in a wide range of scientific areas. Therefore, researchers need better and more appropriate anaesthetics for stressful and/or painful procedures to prevent unpleasant experiences. Thus, we aimed to study if adult zebrafish displayed aversion-associated behaviours (conditioned place aversion) and alterations in cortisol levels when exposed to equipotent concentrations of MS222, propofol/lidocaine, clove oil, or etomidate. Adult AB zebrafish (mixed-sex, N = 177) were randomly assigned to MS222 (150 mg/L), Propofol/Lidocaine (5 mg/L propofol + 150 mg/L lidocaine), Clove Oil (45 mg/L), or Etomidate (2 mg/L) groups. The conditioned place aversion test was used to assess behavioural aversion. Only etomidate resulted in a similar aversion to the positive control group (HCl; pH = 3). Cortisol levels were measured 5 and 15 min after loss of equilibrium. Etomidate induced low levels of cortisol by impairing its synthesis, whereas all the other groups had similar cortisol levels. Based on our data, etomidate was ruled out as an alternative to MS222, as it showed an aversive profile. The remaining protocols were not innocuous, displaying a weak aversive profile when compared to the positive control. In conclusion, a combination of propofol with lidocaine, clove oil, and MS222 were valid candidates for use as anaesthetic protocols.

Seven steps to enhance Open Science practices in animal science.

The Open Science movement aims at ensuring accessibility, reproducibility, and transparency of research. The adoption of Open Science practices in animal science, however, is still at an early stage. To move ahead as a field, we here provide seven practical steps to embrace Open Science in animal science. We hope that this paper contributes to the shift in research practices of animal scientists towards open, reproducible, and transparent science, enabling the field to gain additional public trust and deal with future challenges to guarantee reliable research. Although the paper targets primarily animal science researchers, the steps discussed here are also applicable to other research domains.

The assessment of researchers' competence in experimental procedures with laboratory animals: A three-step methodology to develop a global rating scale.

To conduct animal experiments, researchers must be competent to handle and perform interventions on living animals in compliance with regulations. Laboratory animal science training programmes and licensing bodies therefore need to be able to reliably ensure and certify the professional competence of researchers and technicians. This requires access to assessment strategies which can verify knowledge as well as capturing performative and behavioural dimensions of assessment. In this paper, we describe the process of developing different global rating scales measuring candidates' competence in a performative assessment. We set out the following sequence, with three crucial phases, in the process of scale development: (a) Item Development, (b) Scale Development and (c) Piloting of the Scale. We note each phase's different sub-steps. Despite the emergent need to ensure the competence of researchers using animals in scientific procedures, to our best knowledge there are very few species and procedure/skill specific assessment tools for this purpose, and the assessment methodology literature in the field is very limited. This paper provides guidance for those who need to develop and assess proficiency in laboratory animal procedures by setting out a method that can be used to create the required tools and illustrating how competence assessment strategies can be implemented.

Improving dog training methods: Efficacy and efficiency of reward and mixed training methods.

Dogs play an important role in our society as companions and work partners, and proper training of these dogs is pivotal. For companion dogs, training helps preventing or managing dog behavioral problems-the most frequently cited reason for relinquishing and euthanasia, and it promotes successful dog-human relationships and thus maximizes benefits humans derive from bonding with dogs. For working dogs, training is crucial for them to successfully accomplish their jobs. Dog training methods range widely from those using predominantly aversive stimuli (aversive methods), to those combining aversive and rewarding stimuli (mixed methods) and those focusing on the use of rewards (reward methods). The use of aversive stimuli in training is highly controversial and several veterinary and animal protection organizations have recommended a ban on pinch collars, e-collars and other techniques that induce fear or pain in dogs, on the grounds that such methods compromise dog welfare. At the same time, training methods based on the use of rewards are claimed to be more humane and equally or more effective than aversive or mixed methods. This important discussion, however, has not always been based in solid scientific evidence. Although there is growing scientific evidence that training with aversive stimuli has a negative impact on dog welfare, the scientific literature on the efficacy and efficiency of the different methodologies is scarce and inconsistent. Hence, the goal of the current study is to investigate the efficacy and efficiency of different dog training methods. To that end, we will apply different dog training methods in a population of working dogs and evaluate the outcome after a period of training. The use of working dogs will allow for a rigorous experimental design and control, with randomization of treatments. Military (n = 10) and police (n = 20) dogs will be pseudo-randomly allocated to two groups. One group will be trained to perform a set of tasks (food refusal, interrupted recall, dumbbell retrieval and placing items in a basket) using reward methods and the other group will be trained for the same tasks using mixed methods. Later, the dogs will perform a standardized test where they will be required to perform the trained behaviors. The reliability of the behaviors and the time taken to learn them will be assessed in order to evaluate the efficacy and efficiency, respectively, of the different training methods. This study will be performed in collaboration with the Portuguese Army and with the Portuguese Public Security Police (PSP) and integrated with their dog training programs.

From Unpleasant to Unbearable-Why and How to Implement an Upper Limit to Pain and Other Forms of Suffering in Research with Animals.

The focus of this paper is the requirement that the use of live animals in experiments and in vivo assays should never be allowed if those uses involve severe suffering. This requirement was first implemented in Danish legislation, was later adopted by the European Union, and has had limited uptake in North America. Animal suffering can arise from exposure to a wide range of different external and internal events that threaten biological or social functions, while the severity of suffering may be influenced by the animals' perceptions of their own situation and the degree of control they are able to exert. Severe suffering is more than an incremental increase in negative state(s) but involves a qualitative shift whereby the normal mechanisms to contain or keep negative states at arm's length no longer function. The result of severe suffering will be a loss of the ability of cope. The idea of putting a cap on severe suffering may be justified from multiple ethical perspectives. In most, if not all, cases it is possible to avoid imposing severe suffering on animals during experiments without giving up the potential benefits of finding new ways to cure, prevent, or alleviate serious human diseases and generate other important knowledge. From this it follows that there is a strong ethical case to favor a regulatory ban on animal experiments involving severe suffering.

Adult Zebrafish Anesthesia: A Study of Efficacy and Behavioral Recovery of Different Anesthetics.

The use of proper anesthesia in zebrafish research is essential to ensure fish welfare and data reliability. However, anesthesia long-term side effects remain poorly understood. The purpose of this study was to assess anesthesia quality and recovery in adult zebrafish using different anesthetic protocols and to determine possible long-term effects on the fish activity and anxiety-like behaviors after anesthesia. Mixed-sex adult AB zebrafish were randomly assigned to five different groups (Control, 175 mg/L of tricaine methanesulfonate [MS222], 45 mg/L of clove oil, 2 mg/L of etomidate, and 5 mg/L of propofol combined with 150 mg/L of lidocaine) and placed in the respective anesthetic bath. Time to lose the equilibrium, response to touch and to caudal fin pinch stimuli, and recovery after anesthesia administration were evaluated. In addition, after stopping anesthesia, respiratory rate, activity, and anxiety-like behaviors in the novel tank test were studied. Overall, all protocols proved to be adequate for zebrafish anesthesia research as they showed full recovery at 1 h, and only etomidate had minor effects on fish behavior in the novel tank, a validated test for anxiety.

Organoids as host models for infection biology - a review of methods.

Infectious diseases are a major threat worldwide. With the alarming rise of antimicrobial resistance and emergence of new potential pathogens, a better understanding of the infection process is urgently needed. Over the last century, the development of in vitro and in vivo models has led to remarkable contributions to the current knowledge in the field of infection biology. However, applying recent advances in organoid culture technology to research infectious diseases is now taking the field to a higher level of complexity. Here, we describe the current methods available for the study of infectious diseases using organoid cultures.