Pain in laboratory animals: the ethical and regulatory imperatives

Antibacterial sponge for rapid noncompressible hemostatic treatment: spatiotemporal studies using a noninvasive model

Hemorrhage is one of the leading causes of preventable death. While minor injuries can be treated mainly by conventional methods, deep and irregular wounds with profuse bleeding present significant challenges, some of which can be life-threatening and fatal. This underscores the need to develop easily applicable FDA-approved hemostatic treatments that can effectively stanch blood loss at the point of care before professional medical care. A silicone-based bandage system (SilFoam), a non-compressible, self-expanding, antibacterial hemostatic treatment, is reported here. Its two-component system reacts in situ upon mixing to form a stretchable sponge that acts as a 'tamponade' by expanding within seconds with the evolution of oxygen gas from the interaction of the reactive components present in the formulation. This generates autogenous pressure on the wound that can effectively arrest heavy bleeding within minutes. Possessing optimal adhesive properties, the expanded sponge can be easily removed, rendering it optimal for hemostatic wound dressing. With recent advances in biotechnological research, there is a growing awareness of the potential issues associated with in vivo trials, spanning ethical, psychological, economic, and physiological concerns like burnout and fatigue. Bearing this in mind, a unique manikin system simulating a deep abdominal wound has been employed to investigate SilFoam's hemostatic efficacy with different blood-flow rates using a non-invasive model that aims to provide an easy, fast, and economical route to test hemostatic treatments before in vivo studies. This is the first time an Ag2O-based oxygen-induced foaming system has been reported as a hemostatic agent.

A Commentary on Fasting of Nonclinical Research Animals

This commentary discusses the implementation of fasting in nonclinical animal experimental subjects. The short-term removal of food from cages of experimental animals is in all respects innocuous. The term "stress" is ill-defined and the statutes and regulations governing animal research laboratories that exert their authority in the performance of their operations do so without substantive grounds to base compliance. The legislative and administrative history of the implementation of the Animal Welfare Act (AWA) has evolved into the development of laboratory management strategies that focus on the reduction of the biological cost of stress to the animals and the determination of when subclinical stress (eustress) becomes distress. Animal welfare is based on the tenet that in laboratories conducting animal research in compliance with Good Laboratory Practices (Title 21 USC, Chapter 13,§58), it is the study protocol and the study director that establish procedures and processes that are approved by each Institutional Animal Care and Use Committee to ensure the humane care and use of animals in research, teaching, and testing and to ensure compliance with guidelines and regulations. This approval process establishes the justification of eustress in the environment that do not rise to the threshold of distress under the AWA.

An investigation of the perceptions of laboratory animal welfare issues among undergraduate and graduate veterinary students in southeastern China

Animal experiments have played a significant role in advancing scientific knowledge and enhancing people's quality of life. In order to better understand the opinions and knowledge of veterinary students in the domain of laboratory animal welfare and to explore and advance the teaching methods used in animal ethics education, a questionnaire was designed and used to conduct a survey among undergraduate and postgraduate students majoring in veterinary medicine. The survey encompassed various topics, such as students' level of knowledge about animal welfare, their perspectives on laboratory animals, their proficiency with animal experiments, and their opinions on teaching methods and content. The respondents were a total of 150 undergraduate students and 148 graduate students. The survey results indicated that most students expressed a strong sense of responsibility for the safeguarding of the welfare of experimental animals. However, there were a few students who lacked compassion for animals. Additionally, there was a general lack of basic theoretical knowledge of animal ethics and an inadequate grasp of experimental techniques among current students. Furthermore, most of the participants expressed a strong sense of responsibility to advocate for animal welfare. Although a substantial number of students were unaware of the existence of agencies for the supervision of work involving laboratory animals, they supported teaching and supervision in the domain of animal welfare and were open to various teaching methods and topics of content. In conclusion, targeted training and education regarding laboratory animal welfare and ethics should be conducted in the future to address the specific needs of students. This study provides a foundation for future animal welfare education and will help to improve the professional skills and humanistic qualities of veterinary students.

Adult Animal Stem Cell-Derived Organoids in Biomedical Research and the One Health Paradigm

Preclinical biomedical research is limited by the predictiveness of in vivo and in vitro models. While in vivo models offer the most complex system for experimentation, they are also limited by ethical, financial, and experimental constraints. In vitro models are simplified models that do not offer the same complexity as living animals but do offer financial affordability and more experimental freedom; therefore, they are commonly used. Traditional 2D cell lines cannot fully simulate the complexity of the epithelium of healthy organs and limit scientific progress. The One Health Initiative was established to consolidate human, animal, and environmental health while also tackling complex and multifactorial medical problems. Reverse translational research allows for the sharing of knowledge between clinical research in veterinary and human medicine. Recently, organoid technology has been developed to mimic the original organ's epithelial microstructure and function more reliably. While human and murine organoids are available, numerous other organoids have been derived from traditional veterinary animals and exotic species in the last decade. With these additional organoid models, species previously excluded from in vitro research are becoming accessible, therefore unlocking potential translational and reverse translational applications of animals with unique adaptations that overcome common problems in veterinary and human medicine.

The Roles of Endogenous Opioids in Placebo and Nocebo Effects: From Pain to Performance to Prozac

Placebo and nocebo effects have been well documented for nearly two centuries. However, research has only relatively recently begun to explicate the neurobiological underpinnings of these phenomena. Similarly, research on the broader social implications of placebo/nocebo effects, especially within healthcare delivery settings, is in a nascent stage. Biological and psychosocial outcomes of placebo/nocebo effects are of equal relevance. A common pathway for such outcomes is the endogenous opioid system. This chapter describes the history of placebo/nocebo in medicine; delineates the current state of the literature related to placebo/nocebo in relation to pain modulation; summarizes research findings related to human performance in sports and exercise; discusses the implications of placebo/nocebo effects among diverse patient populations; and describes placebo/nocebo influences in research related to psychopharmacology, including the relevance of endogenous opioids to new lines of research on antidepressant pharmacotherapies.

Simplified assessment of castration-induced pain in pigs using lower complexity algorithms

Pigs are raised on a global scale for commercial or research purposes and often experience pain as a by product of management practices and procedures performed. Therefore, ensuring pain can be effectively identified and monitored in these settings is critical to ensure appropriate pig welfare. The Unesp-Botucatu Pig Composite Acute Pain Scale (UPAPS) was validated to diagnose pain in pre-weaned and weaned pigs using a combination of six behavioral items. To date, statistical weighting of supervised and unsupervised algorithms was not compared in ranking pain-altered behaviors in swine has not been performed. Therefore, the aim of this study was to verify if supervised and unsupervised algorithms with different levels of complexity can improve UPAPS pain diagnosis in pigs undergoing castration. The predictive capacity of the algorithms was evaluated by the area under the curve (AUC). Lower complexity algorithms containing fewer pain-altered behaviors had similar AUC (90.1-90.6) than algorithms containing five (89.18-91.24) and UPAPS (90.58). In conclusion, utilizing a short version of the UPAPS did not influence the predictive capacity of the scale, and therefore it may be easier to apply and be implemented consistently to monitor pain in commercial and experimental settings.

Effects of assessment method (real-time versus video-recorded) on a validated pain-altered behavior scale used in castrated piglets

We aimed to compare two assessment methodologies (real-time vs. video-recorded) using the Unesp-Botucatu Pig Composite Acute Pain Scale (UPAPS) in piglets before and after castration. Twenty-nine male piglets were castrated. Four observers scored the UPAPS over three perioperative timepoints of castration following two assessment methodologies. In real-time assessments, the observers were in-person observing the piglets in front of the pen. After two weeks, the observers did video-recorded assessments randomizing piglets and timepoints. Modeling was conducted to compare the UPAPS and each pain-altered behavior between methodologies. Intraclass correlation coefficient (ICC), Bland-Altman, and Lin's concordance correlation coefficient (CCC) were conducted to investigate agreement between methodologies. UPAPS was statistically equivalent between methodologies (P = 0.4371). The ICC for each method was very good (0.85 to 0.91). The agreement of the UPAPS assessed between methodologies had minimal bias (- 0.04), no proportion bias, and 53% of the assessments presented a perfect agreement. However, CCC of the UPAPS was moderate (0.65), and only one pain-altered behavior ("presents difficulty in overcoming obstacles or other animals") occurred more in real-time assessments (P = 0.0444). In conclusion, piglet pain assessment by UPAPS can be conducted in real-time based on a suitable agreement between the real-time and video-recorded assessment methods.

Alternatives to animal models to study bacterial infections

Animal testing has made a significant and unequalled contribution to important discoveries and advancements in the fields of research, medicine, vaccine development, and drug discovery. Each year, millions of animals are sacrificed for various experiments, and this is an ongoing process. However, the debate on the ethical and sensible usage of animals in in vivo experimentation is equally important. The need to explore and adopt newer alternatives to animals so as to comply with the goal of reduce, refine, and replace needs attention. Besides the ever-increasing debate on ethical issues, animal research has additional drawbacks (need of trained labour, requirement of breeding area, lengthy protocols, high expenses, transport barriers, difficulty to extrapolate data from animals to humans, etc.). With this scenario, the present review has been framed to give a comprehensive insight into the possible alternative options worth exploring in this direction especially targeting replacements for animal models of bacterial infections. There have been some excellent reviews discussing on the alternate methods for replacing and reducing animals in drug research. However, reviews that discuss the replacements in the field of medical bacteriology with emphasis on animal bacterial infection models are purely limited. The present review discusses on the use of (a) non-mammalian models and (b) alternative systems such as microfluidic chip-based models and microdosing aiming to give a detailed insight into the prospects of these alternative platforms to reduce the number of animals being used in infection studies. This would enlighten the scientific community working in this direction to be well acquainted with the available new approaches and alternatives so that the 3R strategy can be successfully implemented in the field of antibacterial drug research and testing.

Comparison of Systemic Extended-release Buprenorphine and Local Extended-release Bupivacaine-Meloxicam as Analgesics for Laparotomy in Mice

Extended-release (ER) local anesthetics can be used in multi-modal analgesia or in situations in which systemic analgesics may alter animal physiology and thus introduce interpretational confounds. In this study, we compared the analgesic efficacy of an ER buprenorphine formulation with that of a synergistic combination of ER bupivacaine and meloxicam. Female and male CD1 mice were randomly assigned to receive subcutaneous buprenorphine (3.25mg/kg) preemptively, subcutaneous infiltration of bupivacaine???meloxicam (0.03mL at incision closure (bupivacaine, 35mg/kg; meloxicam, 1mg/kg), or saline (10mL/kg SC) after induction of anesthesia. After laparotomy, mice were assessed for changes in daily body weight, rearing frequency, nest consolidation scores, time-to-integrate-nest test (TINT), and response to von Frey testing at 4, 8, 24, 48, and 72h after surgery. Daily weight, nest consolidation scores and rearing frequency were not significantly different among the 3 groups. TINT had fallen significantly response at 24 and 48h after injection in the ER buprenorphine group as compared with the saline and ER bupivacaine-meloxicam groups. Nociceptive thresholds, as assessed with von Frey testing, differed between saline controls and both analgesic groups at 4, 8, 24, 48, and 72 h after surgery. None of the mice in the bupivacaine???meloxicam group developed signs of neurotoxicity, a potential side effect of high-dose local anesthetics. This study demonstrates that local ER bupivacaine???meloxicam may be a useful alternative to systemic, ER buprenorphine for the relief of pain after laparotomy in mice.

Recordings in an integrating central neuron reveal the mode of action of isoeugenol

Although isoeugenol is one of the most widely used anesthetics in fish, its actual mode of action and thus its applicability for particular interventions is poorly understood. Here we determined effects of isoeugenol on various aspects of sensory and neural function, taking advantage of intracellular in vivo recordings in a uniquely suited identified neuron, the Mauthner neuron in the brain of goldfish. We show that isoeugenol strongly affects hearing and vision, but sensitivity and time course of action differed largely in these two senses. The action potential, chemical and electric synaptic transmission at the central neuron were not affected at low but efficient anesthesia. Effects seen at high concentration thereby do not support current views of how isoeugenol might act on central neurons. We show that isoeugenol is highly useful to anesthetize fish for handling, but that in more severe treatment its application needs to be carefully adapted to task.

The impact of stress and anesthesia on animal models of infectious disease

Stress and general anesthesia have an impact on the functional response of the organism due to the detrimental effects on cardiovascular, immunological, and metabolic function, which could limit the organism's response to an infectious event. Animal studies have formed an essential step in understanding and mitigating infectious diseases, as the complexities of physiology and immunity cannot yet be replicated in vivo. Using animals in research continues to come under increasing societal scrutiny, and it is therefore crucial that the welfare of animals used in disease research is optimized to meet both societal expectations and improve scientific outcomes. Everyday management and procedures in animal studies are known to cause stress, which can not only cause poorer welfare outcomes, but also introduces variables in disease studies. Whilst general anesthesia is necessary at times to reduce stress and enhance animal welfare in disease research, evidence of physiological and immunological disruption caused by general anesthesia is increasing. To better understand and quantify the effects of stress and anesthesia on disease study and welfare outcomes, utilizing the most appropriate animal monitoring strategies is imperative. This article aims to analyze recent scientific evidence about the impact of stress and anesthesia as uncontrolled variables, as well as reviewing monitoring strategies and technologies in animal models during infectious diseases.

Ethical considerations regarding animal experimentation

Animal experimentation is widely used around the world for the identification of the root causes of various diseases in humans and animals and for exploring treatment options. Among the several animal species, rats, mice and purpose-bred birds comprise almost 90% of the animals that are used for research purpose. However, growing awareness of the sentience of animals and their experience of pain and suffering has led to strong opposition to animal research among many scientists and the general public. In addition, the usefulness of extrapolating animal data to humans has been questioned. This has led to Ethical Committees' adoption of the 'four Rs' principles (Reduction, Refinement, Replacement and Responsibility) as a guide when making decisions regarding animal experimentation. Some of the essential considerations for humane animal experimentation are presented in this review along with the requirement for investigator training. Due to the ethical issues surrounding the use of animals in experimentation, their use is declining in those research areas where alternative in vitro or in silico methods are available. However, so far it has not been possible to dispense with experimental animals completely and further research is needed to provide a road map to robust alternatives before their use can be fully discontinued.

Chronic cerebral hypoperfusion and blood-brain barrier disruption in uninjured brain areas of rhesus monkeys subjected to transient ischemic stroke

Blood-brain barrier (BBB) disruption is a pivotal pathophysiological process in ischemic stroke. Although temporal changes in BBB permeability during the acute phase have been widely studied, little is known about the chronic phase of cerebrovascular changes that may have a large impact on the long-term outcome. Therefore, this study was aimed to measure cerebral vascular abnormalities using CT perfusion in nine rhesus monkeys subjected to transient middle cerebral artery occlusion (tMCAO) for ≥1 year (MCAO-1Y+). The level of cerebral perfusion demonstrated by mean transit time was significantly higher in the ipsilateral caudate nucleus, white matter, thalamus, hippocampus, and contralateral thalamus in MCAO-1Y+ compared with the other nine age-matched control monkeys. The increase in BBB permeability measured through the permeability surface was found in the same ten regions of interest ipsilaterally and contralaterally. We also found decreased levels of Aβ 42/40 ratio in the cerebrospinal fluid (CSF), suggesting a potential link between post-MCAO cognitive decline and Aβ metabolism. Overall, we demonstrated significant cerebral hypoperfusion, BBB disruption, and CSF Aβ decrease during the rehabilitation stage of ischemic stroke in a non-human primate model. Future studies are needed to elucidate the cause-effect relationship between cerebrovascular disruptions and long-term neurological deficits.

Current ecotoxicity testing needs among selected U.S. federal agencies

U.S. regulatory and research agencies use ecotoxicity test data to assess the hazards associated with substances that may be released into the environment, including but not limited to industrial chemicals, pharmaceuticals, pesticides, food additives, and color additives. These data are used to conduct hazard assessments and evaluate potential risks to aquatic life (e.g., invertebrates, fish), birds, wildlife species, or the environment. To identify opportunities for regulatory uses of non-animal replacements for ecotoxicity tests, the needs and uses for data from tests utilizing animals must first be clarified. Accordingly, the objective of this review was to identify the ecotoxicity test data relied upon by U.S. federal agencies. The standards, test guidelines, guidance documents, and/or endpoints that are used to address each of the agencies' regulatory and research needs regarding ecotoxicity testing are described in the context of their application to decision-making. Testing and information use, needs, and/or requirements relevant to the regulatory or programmatic mandates of the agencies taking part in the Interagency Coordinating Committee on the Validation of Alternative Methods Ecotoxicology Workgroup are captured. This information will be useful for coordinating efforts to develop and implement alternative test methods to reduce, refine, or replace animal use in chemical safety evaluations.

Locating the 'culture wars' in laboratory animal research: national constitutions and global competition

The increasingly global scope of biomedical research and testing using animals is generating disagreement over the best way to regulate laboratory animal science and care. Despite many common aims, the practices through which political and epistemic authority are allocated in the regulations around animal research varies internationally, coming together in what can be identified as different national constitutions. Tensions between these periodically erupt within the laboratory animal research community as a 'cultural war' between those favouring centralised control and those advocating local flexibility. Drawing on long-term engagement with key events and actors in these policy debates, I propose these national differences in the constitution of animal research can be understood through the intersection of two key variables: i) the location of institutional responsibility to permit research projects and ii) the distribution of epistemic authority to shape research practices. These variables are used to explain the development of different policy frameworks in the UK, Europe, and the USA, and identify where there is convergence and divergence in practice. Concluding, I suggest the way these approaches are combined and enacted in different countries reflects different national civic epistemologies, which are coming into conflict in the increasingly global networks of laboratory animal science.

Expression of p53 Protein Associates with Anti-PD-L1 Treatment Response on Human-Derived Xenograft Model of GATA3/CR5/6-Negative Recurrent Nonmuscular Invasive Bladder Urothelial Carcinoma

BACKGROUND

The possible involvement of p53 signaling, FGFR3 expression, and FGFR3 mutation rates in the prediction of the NMIBC anti-PD-L1 treatment response needs to be clarified. The main aim of our study was to explore predictive value of p53 expression, FGFR3 expression, and its gene mutation status for the therapeutic success of anti-PD-L1 treatment in the patient-derived murine model of recurrent high-PD-L1(+) GATA3(-)/CR5/6(-) high-grade and low-grade NMIBC.

METHODS

twenty lines of patient-derived xenografts (PDXs) of relapsed high-PD-L1(+) double-negative NMIBC were developed, of which 10 lines represented high-grade tumors and the other ones-low-grade bladder cancer. Acceptors of each grade-related branch received specific anti-PD-L1 antibodies. Animals' survival, tumor-doubling time, and remote metastasis were followed during the post-interventional period. PD-L1, GATA3, CR5/6, and p53 protein expressions in engrafted tumors were assessed by immunohistochemistry. The FGFR3 expression and FGFR3 mutations in codons 248 and 249 were detected by real-time polymerase chain reaction.

RESULTS

The expression of p53 protein is an independent factor affecting the animals' survival time [HR = 0.036, p = 0.031] of anti-PD-L1-treated mice with low-grade high-PD-L1(+) double-negative NMIBC PDX. The FGFR3 expression and FGFR3 mutation rate have no impact on the anti-PD-L1 treatment response in the interventional groups.

CONCLUSIONS

p53 expression may be considered as a prognostic factor for the anti-PD-L1 treatment efficacy of low-grade high-PD-L1-positive GATA3(-)/CR5/6(-)-relapsed noninvasive bladder cancer.

Lidocaine and bupivacaine as part of multimodal pain management in a C57BL/6J laparotomy mouse model

While the use of local anesthesia as part of multimodal pain management is common practice in human and veterinarian surgery, these drugs are not applied routinely in rodent surgery. Several recommendations on the use of local anesthesia exist, but systematic studies on their efficacy and side effects are lacking. In the present study, male and female C57BL/6J mice were subjected to a sham vasectomy or a sham embryo transfer, respectively. We tested whether a mixture of subcutaneously injected Lidocaine and Bupivacaine in combination with systemic Paracetamol applied via drinking water results in superior pain relief when compared to treatment with local anesthesia or Paracetamol alone. We applied a combination of methods to assess behavioral, emotional, and physiological changes indicative of pain. Voluntary Paracetamol intake via drinking water reached the target dosage of 200 mg/kg in most animals. Local anesthesia did not lead to obvious side effects such as irregular wound healing or systemic disorders. No relevant sex differences were detected in our study. Sevoflurane anesthesia and surgery affected physiological and behavioral measurements. Surprisingly, Paracetamol treatment alone significantly increased the Mouse Grimace Scale. Taken together, mice treated with a combination of local anesthesia and systemic analgesia did not show fewer signs of post-surgical pain or improved recovery compared to animals treated with either local anesthesia or Paracetamol.

Current Methods to Investigate Nociception and Pain in Zebrafish

Pain is an unpleasant, negative emotion and its debilitating effects are complex to manage. Mammalian models have long dominated research on nociception and pain, but there is increasing evidence for comparable processes in fish. The need to improve existing pain models for drug research and the obligation for 3R refinement of fish procedures facilitated the development of numerous new assays of nociception and pain in fish. The zebrafish is already a well-established animal model in many other research areas like toxicity testing, as model for diseases or regeneration and has great potential in pain research, too. Methods of electrophysiology, molecular biology, analysis of reflexive or non-reflexive behavior and fluorescent imaging are routinely applied but it is the combination of these tools what makes the zebrafish model so powerful. Simultaneously, observing complex behavior in free-swimming larvae, as well as their neuronal activity at the cellular level, opens new avenues for pain research. This review aims to supply a toolbox for researchers by summarizing current methods to study nociception and pain in zebrafish. We identify treatments with the best algogenic potential, be it chemical, thermal or electric stimuli and discuss options of analgesia to counter effects of nociception and pain by opioids, non-steroidal anti-inflammatory drugs (NSAIDs) or local anesthetics. In addition, we critically evaluate these practices, identify gaps of knowledge and outline potential future developments.

Supportive care for animals on toxicology studies: An industrial best practices survey conducted by the IQ 3Rs TPS CRO Outreach Working Group

Contract Research Organizations (CROs) conducting toxicology studies on behalf of biopharmaceutical sponsors and others routinely provide supportive care for animals to minimize pain and distress on studies. A large number of guidance documents govern the care of experimental animals, however there is currently no uniform approach on the communication between sponsor and their CRO partners in providing a standard definition of and strategies for administering supportive care in toxicity studies. This survey was conducted by the CRO Outreach Working Group (WG), a part of the 3Rs Translational and Predictive Sciences (TPS) Leadership Group of the International Consortium for Innovation and Quality in Pharmaceutical Development (IQ Consortium), to better understand the provision of supportive care on nonclinical studies. The survey aimed to define supportive care strategies, identify alternatives to supportive care, and understand regulatory feedback and implications about supportive care decisions. The survey was distributed to members of the 3Rs Leadership Group of the IQ Consortium and several CRO partners, representing 35 organizations as potential respondents. The results of the survey from 13 respondents provided positive feedback that helped in highlighting the existing best practices for supportive care. Areas of enhancements identified included greater consistency in the inclusion of sponsor veterinarians on project teams for externalized studies, the timing of initiation of supportive care, and increased sharing of regulatory outcomes. Suggested best practices include creating a plan of action for veterinary care prior to study start, and enhancing information sharing regarding expected toxicities from previous study findings. Improved communication regarding supportive care will pave the way for enhanced 3Rs initiatives, refining the existing animal care paradigm and helping to ensure the most ethical toxicology study designs.

In vitro and in vivo anti-inflammatory effects of an ethanol extract from the aerial parts of Eryngium carlinae F. Delaroche (Apiaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Eryngium carlinae F. Delaroche (Apiaceae) is an herb used in folk medicine as a diuretic, analgesic, and anti-inflammatory agent.

AIM OF THE STUDY

This work assessed the diuretic, antinociceptive, and anti-inflammatory actions of an ethanol extract from the leaves and stems of Eryngium carlinae (ECE). These ethnomedicinal properties of ECE were scientifically validated using in vitro and in vivo assays.

MATERIALS AND METHODS

The antinociceptive and diuretic actions of ECE (10-200 mg/kg p.o.) were assessed with the acetic acid-induced writhing test and by using metabolic cages to house mice, respectively. The in vitro anti-inflammatory actions of ECE (1-500 μg/ml) were evaluated using LPS-stimulated primary murine macrophages, and the in vivo anti-inflammatory actions were assessed using the TPA-induced ear edema test (2 mg/ear) and carrageenan-induced paw edema test (50-200 mg/kg p.o.). The production of inflammatory mediators was estimated using in vitro and in vivo assays.

RESULTS

ECE lacked antinociceptive and diuretic effects. ECE increased the production of IL-10 in LPS-stimulated macrophages (EC₅₀ = 37.8 pg/ml) and the carrageenan-induced paw edema test (ED₅₀ = 82.6 mg/kg). ECE showed similar in vivo anti-inflammatory actions compared to those observed with indomethacin.

CONCLUSION

ECE exerts in vitro and in vivo anti-inflammatory effects by increasing the release of IL-10.

Animal experimentation: implementation and application of the 3Rs

Despite the development of powerful molecular biological techniques and technologies, studies involving research animals remain a key component of discovery biology, and in the discovery and development of new medicines. In 1959, The Principles of Humane Experimental Technique, the 3Rs (Replacement, Reduction and Refinement) were developed to provide a framework to ensure animal research was undertaken as humanely as possible. Sixty years since their inception, the extent to which the 3Rs have been adopted and implemented by the global scientific and medical research communities has unfortunately been slow and patchy. However, this situation is changing rapidly as awareness increases, not only of the 3Rs themselves, but of the impact of animal welfare on the reproducibility, reliability and translatability of data from animal studies.

Virtue Ethics and Laboratory Animal Research

This article appeals to virtue ethics to help guide laboratory animal research by considering the role of character and flourishing in these practices. Philosophical approaches to animal research ethics have typically focused on animal rights or on the promotion of welfare for all affected, while animal research itself has been guided in its practice by the 3Rs (reduction, refinement, replacement). These different approaches have sometimes led to an impasse in debates over animal research where the philosophical approaches are focused on whether or when animal studies are justifiable, while the 3Rs assume a general justification for animal work but aim to reduce harm to sentient animals and increase their welfare in laboratory spaces. Missing in this exchange is a moral framework that neither assumes nor rejects the justifiability of animal research and focuses instead on the habits and structures of that work. I shall propose a place for virtue ethics in laboratory animal research by considering examples of relevant character traits, the moral significance of human-animal bonds, mentorship in the laboratory, and the importance of animals flourishing beyond mere welfare.

Everything You Need to Know About Satisfying IACUC Protocol Requirements

There have been recent efforts to reduce the administrative burden imposed on investigators. Although a complete and thorough review of proposed animal studies is an essential function of the Institutional Animal Care and Use Committee (IACUC), efforts to streamline and clarify this process may help investigators spend less time writing animal use protocols and responding to committee comments. The IACUC relies on well-written protocols for an efficient review process. A well-designed protocol form is also critical in guiding investigators through the process. However, it is ultimately the investigators' responsibility to ensure that the information they provide answers all the IACUC's questions with enough detail and quality for a fast and effective review. This article, aimed primarily for researchers but also IACUC administrators, provides an overview of the IACUC protocol review and approval process, the criteria that the IACUC uses for evaluations, and the type of information that should be included in the various sections of the protocol form. Some specific examples are also provided.

Preliminary survey of the attitudes of Brazilian scientists towards pain management and assessment in animals used in science

OBJECTIVE

To investigate the current scenario in Brazil regarding pain assessment and control in experimental animals.

STUDY DESIGN

Prospective survey.

METHODS

A confidential questionnaire was available online and sent by e-mail to Brazilian scientists working with animal experimentation in Brazil. Data collection was conducted from October 2016 to October 2017. The exclusion criteria included blank questionnaires or with <80% completed responses, researchers not performing experiments involving animals and foreign scientists.

RESULTS

A total of 96 questionnaires from 104 respondents were analyzed. The Fisher's exact test showed a disparity between the proportions of scientists who recognized the importance of analgesia and their application of analgesic techniques in painful procedures (p < 0.0003), and also for the researchers who assumed that experiments inflicted pain and their classification of the degree of invasiveness (p < 0.0001), indicating their insufficient knowledge of these topics. Overall, 77% of institutions did not offer specific training to assess pain in experimental animals, and 24% of respondents had no training to work with animal experimentation. In total, 62% of the studies inflicted pain, 48% of respondents used pain scales, and the drugs administered most frequently for pain management were morphine (44%), meloxicam (43%) and tramadol (37%); 15% of respondents did not include analgesics even though their studies inflicted pain. Commonly used animals were rats (33%), mice (29%) and rabbits (8%).

CONCLUSIONS AND CLINICAL RELEVANCE

The results of this preliminary survey indicated that in Brazil there is a gap in the knowledge and training on pain assessment and management of experimental animals. Therefore, there is a necessity for an educational program to prepare and train scientists to assess and manage pain in laboratory or experimental animals. Further studies using a psychometrically validated survey instrument are warranted.

Antinociceptive and anti-inflammatory effects of Cuphea aequipetala Cav (Lythraceae)

Cuphea aequipetala Cav (Lythraceae) is an herb used in folk treatment for pain and inflammation. The aim of this study was to evaluate the antinociceptive and anti-inflammatory actions of an ethanol extract from the leaves and stem of Cuphea aequipetala (CAE). The antinociceptive actions of CAE (10-200 mg/kg p.o.) were assessed with the acetic acid-induced writhing, hot plate, and formalin tests. The possible mechanism of action of CAE was evaluated using inhibitors. The effects of CAE on motor coordination were assessed by the rotarod test. The in vitro anti-inflammatory actions of CAE were evaluated using LPS-stimulated primary murine macrophages, and the in vivo anti-inflammatory actions were assessed by the TPA-induced ear oedema and the carrageenan-induced paw oedema tests. The production of inflammatory mediators was estimated from both in vitro and in vivo assays. CAE showed antinociception (ED₅₀ = 90 mg/kg) in the acetic acid test and in the second phase of the formalin test (ED₅₀ = 158 mg/kg). Pretreatment with glibenclamide or L-NAME partially reversed the antinociception shown by the plant extract. CAE (50-200 mg/kg) did not affect motor coordination in mice. CAE increased the production of IL-10 in LPS-stimulated macrophages (EC₅₀ = 10 pg/ml) and, in the carrageenan-induced paw oedema test (threefold increase). In conclusion, CAE induced antinociceptive effects without affecting motor coordination, probably due to the involvement of nitric oxide and ATP-sensitive K⁺ channels. CAE also exerts in vitro and in vivo anti-inflammatory effects by increasing the release of IL-10.

Mesenchymal stromal cells from dermal and adipose tissues induce macrophage polarization to a pro-repair phenotype and improve skin wound healing

The process of wound healing restores skin homeostasis but not full functionality; thus, novel therapeutic strategies are needed to accelerate wound closure and improve the quality of healing. In this context, tissue engineering and cellular therapies are promising approaches. Although sharing essential characteristics, mesenchymal stromal cells (MSCs) isolated from different tissues might have distinct properties. Therefore, the aim of this study was to comparatively investigate, by a mouse model in vivo assay, the potential use of dermal-derived MSCs (DSCs) and adipose tissue-derived MSCs (ASCs) in improving skin wound healing. Human DSCs and ASCs were delivered to full-thickness mouse wounds by a collagen-based scaffold (Integra Matrix). We found that the association of both DSCs and ASCs with the Integra accelerated wound closure in mice compared with the biomaterial only (control). Both types of MSCs stimulated angiogenesis and extracellular matrix remodeling, leading to better quality scars. However, the DSCs showed smaller scar size,superior extracellular matrix deposition, and greater number of cutaneous appendages. Besides, DSCs and ASCs reduced inflammation by induction of macrophage polarization from a pro-inflammatory (M1) to a pro-repair (M2) phenotype. In conclusion, both DSCs and ASCs were able to accelerate the healing of mice skin wounds and promote repair with scars of better quality and more similar to healthy skin than the empty scaffold. DSCs associated with Integra induced superior overall results than the Integra alone, whereas scaffolds with ASCs showed an intermediate effect, often not significantly better than the empty biomaterial.

Refining rodent models of spinal cord injury

This report was produced by an Expert Working Group (EWG) consisting of UK-based researchers, veterinarians and regulators of animal experiments with specialist knowledge of the use of animal models of spinal cord injury (SCI). It aims to facilitate the implementation of the Three Rs (Replacement, Reduction and Refinement), with an emphasis on refinement. Specific animal welfare issues were identified and discussed, and practical measures proposed, with the aim of reducing animal use and suffering, reducing experimental variability, and increasing translatability within this critically important research field.

Methods for in vivo studies in rodents of chemotherapy induced peripheral neuropathy

Peripheral neuropathy is one of the most common, dose limiting, and long-lasting disabling adverse events of chemotherapy treatment. Unfortunately, no treatment has proven efficacy to prevent this adverse effect in patients or improve the nerve regeneration, once it is established. Experimental models, particularly using rats and mice, are useful to investigate the mechanisms related to axonal or neuronal degeneration and target loss of function induced by neurotoxic drugs, as well as to test new strategies to prevent the development of neuropathy and to improve functional restitution. Therefore, objective and reliable methods should be applied for the assessment of function and innervation in adequately designed in vivo studies of CIPN, taking into account the impact of age, sex and species/strains features. This review gives an overview of the most useful methods to assess sensory, motor and autonomic functions, electrophysiological and morphological tests in rodent models of peripheral neuropathy, focused on CIPN. We include as well a proposal of protocols that may improve the quality and comparability of studies undertaken in different laboratories. It is recommended to apply more than one functional method for each type of function, and to perform parallel morphological studies in the same targets and models.

The current state of animal models in research: A review

Animal models have provided invaluable information in the pursuit of medical knowledge and alleviation of human suffering. The foundations of our basic understanding of disease pathophysiology and human anatomy can largely be attributed to preclinical investigations using various animal models. Recently, however, the scientific community, citing concerns about animal welfare as well as the validity and applicability of outcomes, has called the use of animals in research into question. In this review, we seek to summarize the current state of the use of animal models in research.

Influence of Pain and Analgesia on Orthopedic and Wound-healing Models in Rats and Mice

The surgical stress response and resulting physiologic changes can lead to postoperative complications and negatively impact animal welfare. Although appropriate pain management is crucial to reduce the pain and stress response to surgery, analgesic choice can significantly affect bone and wound healing. This review aims to summarize data from rat and mouse studies and to provide recommendations for integrating analgesia into orthopedic and wound healing models in these species. Data from other species, such as humans, rabbits and other rodents, is included, where available. From these data, we conclude that for orthopedic surgical models, opioids, local anesthetics and dissociative agents have minimal impact on fracture healing; cyclooxygenase 2 (COX2) selective nonsteroidal antiinflammatory drugs (NSAID) may be used in the shortterm; and steroids should be avoided. For wound healing models, short-term systemic or topical opioids have negligible impact on wound healing; NSAID or local anesthetics may be used short-term; and systemic steroids should be avoided. Alternative analgesics such as tramadol, gabapentin, ketamine, and acetaminophen warrant consideration and further evaluation for both orthopedic and wound healing models. In all cases, researchers and veterinarians should work together to determine the appropriate analgesic plan to minimize pain, as well as to minimize unwanted effects on the orthopedic and wound healing models themselves.

Minimum Information in In Vivo Research

Data quality, reproducibility and reliability are a matter of concern in many scientific fields including biomedical research. Robust, reproducible data and scientific rigour form the foundation on which future studies are built and determine the pace of knowledge gain and the time needed to develop new and innovative drugs that provide benefit to patients. Critical to the attainment of this is the precise and transparent reporting of data. In the current chapter, we will describe literature highlighting factors that constitute the minimum information that is needed to be included in the reporting of in vivo research. The main part of the chapter will focus on the minimum information that is essential for reporting in a scientific publication. In addition, we will present a table distinguishing information necessary to be recorded in a laboratory notebook or another form of internal protocols versus information that should be reported in a paper. We will use examples from the behavioural literature, in vivo studies where the use of anaesthetics and analgesics are used and finally ex vivo studies including histological evaluations and biochemical assays.

Programmed death-ligand 1 signaling pathway involves in bladder cancer growth and progression

CONTEXT:

Exploration of the biological property of programmed death-ligand 1 (PD-L1) signaling that may impact bladder tumor growth in humanized animals and cell culture.

AIMS:

The aim of this study is to evaluate how PD-L1 signaling involves bladder cancer growth and progression.

SETTINGS AND DESIGN:

This study design involves experimental in vivo and in vivo study.

SUBJECTS AND METHODS:

A role of PD-L1 signaling pathway inhibition for bladder cancer growth was assessed in humanized immunodeficient animals carried main molecular subtypes of bladder carcinoma patient-derived xenografts and provided with selective anti-PD-L1 treatment; bladder cancer cells invasiveness was evaluated in mixed RT112/84 cells + CD4⁺ cells culture incubated with PD-L1 blocker durvalumab. We used two-tailed Student's t-test to explore differences between main and control subgroups. Significance of intergroup comparison was measured with one-way ANOVA followed by the Tukey's or Newman–Keul's criterion. Survival curves were analyzed with Gehan's criterion with the Yate's correction. Differences were considered statistically significant at P < 0.05.

RESULTS:

Anti-PD-L1 intervention increased survival of the animals carried both primary and relapsed luminal noninvasive, muscular invasive, and relapsed luminal bladder cancer xenografts. There was significant retardation of tumor volume duplication time in aforementioned subgroups correlated with PD-L1 expression. Durvalumab treatment in concentration-dependent manner inhibited tumor cells invasiveness of mixed RT112 + CD4⁺ culture cells with its maximum at the highest studied concentration (10 μM).

CONCLUSIONS:

Obtained data constituted the pivotal role of programmed cell death-1/PD-L1 signaling pathway in bladder cancer development and progression. The results will have major implications for further clinical investigations.

Efficacy of a Combination of N-Palmitoylethanolamide, Beta-Caryophyllene, Carnosic Acid, and Myrrh Extract on Chronic Neuropathic Pain: A Preclinical Study

Neuropathic pain (NP) is a common public health problem that poses a major challenge to basic scientists and health-care providers. NP is a complex problem with an unclear etiology and an often-inadequate response to current medications. Despite the high number of drugs available, their limited pharmacological efficacy and side effects hamper their chronic use. Thus, the search for novel treatments is a priority. In addition to pharmaceuticals, natural extracts and food supplements are often used to help treating patients with NP. One such supplement is Noxiall^®, a commercially available combination of N-Palmitoylethanolamide (PEA), beta-caryophyllene; carnosic acid and myrrh. Here, we compare the efficacy of Noxiall^® to that of the medications gabapentin and pregabalin in the NP model of chronic constriction injury (CCI) using sciatic nerve ligation in mouse. Following CCI, mice developed a significant increase in mechanical allodynia and thermal hyperalgesia. Results showed that administration of either Noxiall^®, pregabalin, or gabapentin significantly attenuated mechanical allodynia. The magnitude of the Noxiall^® effect was comparable to that of gabapentin or pregabalin. In addition, co-administration of non-effective doses of pregabalin and Noxiall^® resulted in a significant decrease in NP, suggesting an additive efficacy. Noxiall^® was efficacious also in reducing CCI-induced thermal hyperalgesia. These findings support the rationale of using natural remedies in conjunction with classical pharmacological agents to treat chronic NP.

Patient-Derived Non-Muscular Invasive Bladder Cancer Xenografts of Main Molecular Subtypes of the Tumor for Anti-Pd-l1 Treatment Assessment

Background: Establishment of heterotopic patient-derived xenografts of primary and relapsed non-muscular invasive bladder cancer (NMIBC) to explore the biological property of PD-L1 signaling that may impact bladder tumor growth in humanized animals. Methods: Tumor cells of luminal, basal, and p53 subtypes of primary and relapsed NMIBC were engrafted to irradiated (3.5 Gy) NOG/SCID female mice along with intraperitoneal transplantation of human lymphocytes (5 × 10⁷ cells/mouse); a role of PD-L1 signaling pathway inhibition for bladder cancer growth was assessed in humanized animals that carried PD-L1-expressing main molecular subtypes of bladder carcinoma patient-derived xenografts (PDX) and provided with selective anti-PD-L1 treatment. We used two-tailed Student’s t test to explore differences between main and control subgroups. Significance of intergroup comparison was measured with one-way ANOVA followed by the Tukey’s or Newman–Keul’s criterion. Survival curves were analyzed with the Gehan’s criterion with the Yate’s correction. The Spearman’s correlation was used to assess the link between CD8⁺ expression and sPD-L1 serum level. Differences were considered statistically significant at p < 0.05. Results: Heterotopic primary and relapsed luminal, basal, and p53 subtypes of NMIBC PDXs were established. More than 25% of counted tumor cells of all PDX specimens expressed PD-L1, so the tumors were ranged as PD-L1 positive. Anti-PD-L1 intervention increased survival of the animals that carried both primary and relapsed luminal noninvasive, muscular invasive, and relapsed luminal bladder cancer xenografts. There was significant retardation of tumor volume duplication time in aforementioned subgroups correlated with PD-L1 expression. Bad response of p53 mutant subtypes of NMIBC on specific anti-PD-L1 treatment may be associated with low CD8⁺ cells representation into the tumors tissue. Conclusions: Established PD-L1-positive NMIBC PDXs differently replied on anti-PD-L1 treatment due to both NMIBC molecular subtype and tumor T-suppressors population. The results may have major implications for further clinical investigations.

No Pain, No Gain? In Defence of Genetically Disenhancing (Most) Research Animals

Every year, around 12 million animals are used for the purpose of scientific research in the European Union alone. The procedures performed on them often cause significant pain and suffering. Despite regulations aimed at reducing this suffering, we can expect millions of research animals to continue to suffer in the near to mid-term future. Given this reality, we propose the use of gene editing to create research animals with a reduced capacity for suffering, in particular, from pain. We argue that our proposal would be in line with moral principles embedded in European regulations regarding animal research, and that it would facilitate compliance with these regulations. We also respond to the strongest argument against our proposal-the 'no pain no gain' argument.

Reported analgesic and anaesthetic administration to non-human primates undergoing experimental surgical procedure: 2010-2015

BACKGROUND

The use of non-human primates (NHPs) in research remains a major societal concern with public expectations that appropriate anaesthetics and analgesics are used to minimize any pain or distress caused to animals undergoing invasive procedures. A literature review was conducted to examine the reporting of anaesthesia and analgesia methods used in non-human primates undergoing surgical procedures, with recovery from anaesthesia.

METHODS

A total of 397 papers from peer-review journals published between 2010 and 2015 were examined.

RESULTS

Only 25.9% of papers reported the analgesic regimen used, with carprofen and buprenorphine the 2 most widely used agents. Reporting of the anaesthetic regimens was included in 49.9% of papers. Ketamine and isoflurane were the most frequently used anaesthetic agents.

CONCLUSIONS

Anaesthetic and analgesic regimens administered to NHPs remain poorly reported. This lack of detailed descriptions of protocols does little to reassure the public or regulatory authorities that appropriate high standards of perioperative care are employed.

Preliminary pharmacokinetics of tramadol hydrochloride after administration via different routes in male and female B6 mice

OBJECTIVE

1) To determine the pharmacokinetics of tramadol hydrochloride and its active metabolite, O-desmethyltramadol (M1), after administration through different routes in female and male C57Bl/6 mice; 2) to evaluate the stability of tramadol solutions; and 3) to identify a suitable dose regimen for prospective clinical analgesia in B6 mice.

STUDY DESIGN

Prospective, randomized, blinded, parallel design.

ANIMALS

A total of 18 male and 18 female C57Bl/6 mice (20-30 g).

METHODS

Mice were administered 25 mg kg^-1 tramadol as a bolus [intravenously (IV), intraperitoneally (IP), subcutaneously (SQ), orally per gavage (OS_gavage)] over 25 hours [orally in drinking water (OS_water) or Syrspend SF (OS_Syrsp)]. Venous blood was sampled at six predetermined time points over 4 to 31 hours, depending on administration route, to determine tramadol and M1 plasma concentrations (liquid chromatography and tandem mass spectrometry detection). Pharmacokinetic parameters were described using a noncompartmental model. The stability of tramadol in water (acidified and untreated) and Syrspend SF (0.20 mg mL^-1) at ambient conditions for 1 week was evaluated.

RESULTS

After all administration routes, C_max was >100 ng mL^-1 for tramadol and >40 ng mL^-1 for M1 (reported analgesic ranges in man) followed by short half-lives (2-6 hours). The mean tramadol plasma concentration after self-administration remained >100 ng mL^-1 throughout consumption time. M1 was found in the OS_Syrs group only at 7 hours, whereas it was detectable in OS_water throughout administration. Tramadol had low oral bioavailability (26%). Short-lasting side effects were observed only after IV administration. Water and Syrspend SF solutions were stable for 1 week.

CONCLUSIONS AND CLINICAL RELEVANCE

1) At the dose administered, high plasma concentrations of tramadol and M1 were obtained, with half-life depending on the administration route. 2) Plasma levels were stable over self-consumption time. 3) Solutions were stable for 1 week at ambient conditions.

Expectations for the methodology and translation of animal research: a survey of the general public, medical students and animal researchers in North America

To determine what are considered acceptable standards for animal research (AR) methodology and translation rate to humans, a validated survey was sent to: a) a sample of the general public, via Sampling Survey International (SSI; Canada), Amazon Mechanical Turk (AMT; USA), a Canadian city festival (CF) and a Canadian children's hospital (CH); b) a sample of medical students (two first-year classes); and c) a sample of scientists (corresponding authors and academic paediatricians). There were 1379 responses from the general public sample (SSI, n = 557; AMT, n = 590; CF, n = 195; CH, n = 102), 205/330 (62%) medical student responses, and 23/323 (7%, too few to report) scientist responses. Asked about methodological quality, most of the general public and medical student respondents expect that: AR is of high quality (e.g. anaesthesia and analgesia are monitored, even overnight, and 'humane' euthanasia, optimal statistical design, comprehensive literature review, randomisation and blinding, are performed), and costs and difficulty are not acceptable justifications for lower quality (e.g. costs of expert consultation, or more laboratory staff). Asked about their expectations of translation to humans (of toxicity, carcinogenicity, teratogenicity and treatment findings), most expect translation more than 60% of the time. If translation occurred less than 20% of the time, a minority disagreed that this would "significantly reduce your support for AR". Medical students were more supportive of AR, even if translation occurred less than 20% of the time. Expectations for AR are much higher than empirical data show to have been achieved.

Real-time application of the Rat Grimace Scale as a welfare refinement in laboratory rats

Rodent grimace scales have been recently validated for pain assessment, allowing evaluation of facial expressions associated with pain. The standard scoring method is retrospective, limiting its application beyond pain research. This study aimed to assess if real-time application of the Rat Grimace Scale (RGS) could reliably and accurately assess pain in rats when compared to the standard method. Thirty-two male and female Sprague-Dawley rats were block randomized into three treatment groups: buprenorphine (0.03 mg/kg, subcutaneously), multimodal analgesia (buprenorphine [0.03 mg/kg] and meloxicam [2 mg/kg], subcutaneously), or saline, followed by intra-plantar carrageenan. Real-time observations (interval and point) were compared to the standard RGS method using concurrent video-recordings. Real-time interval observations reflected the results from the standard RGS method by successfully discriminating between analgesia and saline treatments. Real-time point observations showed poor discrimination between treatments. Real-time observations showed minimal bias (<0.1) and acceptable limits of agreement. These results indicate that applying the RGS in real-time through an interval scoring method is feasible and effective, allowing refinement of laboratory rat welfare through rapid identification of pain and early intervention.

Pain and Laboratory Animals: Publication Practices for Better Data Reproducibility and Better Animal Welfare

Scientists who perform major survival surgery on laboratory animals face a dual welfare and methodological challenge: how to choose surgical anesthetics and post-operative analgesics that will best control animal suffering, knowing that both pain and the drugs that manage pain can all affect research outcomes. Scientists who publish full descriptions of animal procedures allow critical and systematic reviews of data, demonstrate their adherence to animal welfare norms, and guide other scientists on how to conduct their own studies in the field. We investigated what information on animal pain management a reasonably diligent scientist might find in planning for a successful experiment. To explore how scientists in a range of fields describe their management of this ethical and methodological concern, we scored 400 scientific articles that included major animal survival surgeries as part of their experimental methods, for the completeness of information on anesthesia and analgesia. The 400 articles (250 accepted for publication pre-2011, and 150 in 2014–15, along with 174 articles they reference) included thoracotomies, craniotomies, gonadectomies, organ transplants, peripheral nerve injuries, spinal laminectomies and orthopedic procedures in dogs, primates, swine, mice, rats and other rodents. We scored articles for Publication Completeness (PC), which was any mention of use of anesthetics or analgesics; Analgesia Use (AU) which was any use of post-surgical analgesics, and Analgesia Completeness (a composite score comprising intra-operative analgesia, extended post-surgical analgesia, and use of multimodal analgesia). 338 of 400 articles were PC. 98 of these 338 were AU, with some mention of analgesia, while 240 of 338 mentioned anesthesia only but not post-surgical analgesia. Journals’ caliber, as measured by their 2013 Impact Factor, had no effect on PC or AU. We found no effect of whether a journal instructs authors to consult the ARRIVE publishing guidelines published in 2010 on PC or AC for the 150 mouse and rat articles in our 2014–15 dataset. None of the 302 articles that were silent about analgesic use included an explicit statement that analgesics were withheld, or a discussion of how pain management or untreated pain might affect results. We conclude that current scientific literature cannot be trusted to present full detail on use of animal anesthetics and analgesics. We report that publication guidelines focus more on other potential sources of bias in experimental results, under-appreciate the potential for pain and pain drugs to skew data, and thus mostly treat pain management as solely an animal welfare concern, in the jurisdiction of animal care and use committees. At the same time, animal welfare regulations do not include guidance on publishing animal data, even though publication is an integral part of the cycle of research and can affect the welfare of animals in studies building on published work, leaving it to journals and authors to voluntarily decide what details of animal use to publish. We suggest that journals, scientists and animal welfare regulators should revise current guidelines and regulations, on treatment of pain and on transparent reporting of treatment of pain, to improve this dual welfare and data-quality deficiency.

Zebrafish response to 3D printed shoals of conspecifics: the effect of body size

Recent progress in three-dimensional (3D) printing technology has enabled rapid prototyping of complex models at a limited cost. Virtually every research laboratory has access to a 3D printer, which can assist in the design and implementation of hypothesis-driven studies on animal behavior. In this study, we explore the possibility of using 3D printing technology to understand the role of body size in the social behavior of the zebrafish model organism. In a dichotomous preference test, we study the behavioral response of zebrafish to shoals of 3D printed replicas of varying size. We systematically vary the size of each replica without altering the coloration, aspect ratio, and stripe patterns, which are all selected to closely mimic zebrafish morphophysiology. The replicas are actuated through a robotic manipulator, mimicking the natural motion of live subjects. Zebrafish preference is assessed by scoring the time spent in the vicinity of the shoal of replicas, and the information theoretic construct of transfer entropy is used to further elucidate the influence of the replicas on zebrafish motion. Our results demonstrate that zebrafish adjust their behavior in response to variations in the size of the replicas. Subjects exhibit an avoidance reaction for larger replicas, and they are attracted toward and influenced by smaller replicas. The approach presented in this study, integrating 3D printing technology, robotics, and information theory, is expected to significantly aid preclinical research on zebrafish behavior.

Would the elimination of the capacity to suffer solve ethical dilemmas in experimental animal research?

The use of genetic engineering to enhance the welfare of laboratory animals can reduce the amount of suffering in current neuroscience research paradigms. In particular, for some forms of basic research, we can use welfare-enhanced animals to reduce harms to animals without sacrificing any of the scientific validity. In another group of experiments, we can use welfare-enhanced animals to dramatically reduce the number of unprotected animals enduring aversive procedures. Many of the objections to using welfare-enhanced animals for food production do not apply to their use in research, since genetic knockout techniques are already used routinely in research for human ends and since there is no risk for human health. Furthermore, examples of recent knockout experiments suggest that we already have, or are very close to having, the capacity to reduce suffering in laboratories via genetic engineering. If we are truly committed to balancing the advancement of science with the welfare of animals, this option should be further explored.

Applying refinement to the use of mice and rats in rheumatoid arthritis research

Rheumatoid arthritis (RA) is a painful, chronic disorder and there is currently an unmet need for effective therapies that will benefit a wide range of patients. The research and development process for therapies and treatments currently involves in vivo studies, which have the potential to cause discomfort, pain or distress. This Working Group report focuses on identifying causes of suffering within commonly used mouse and rat ‘models’ of RA, describing practical refinements to help reduce suffering and improve welfare without compromising the scientific objectives. The report also discusses other, relevant topics including identifying and minimising sources of variation within in vivo RA studies, the potential to provide pain relief including analgesia, welfare assessment, humane endpoints, reporting standards and the potential to replace animals in RA research.

Expectations for methodology and translation of animal research: a survey of health care workers

Background

Health care workers (HCW) often perform, promote, and advocate use of public funds for animal research (AR); therefore, an awareness of the empirical costs and benefits of animal research is an important issue for HCW. We aim to determine what health-care-workers consider should be acceptable standards of AR methodology and translation rate to humans.

Methods

After development and validation, an e-mail survey was sent to all pediatricians and pediatric intensive care unit nurses and respiratory-therapists (RTs) affiliated with a Canadian University. We presented questions about demographics, methodology of AR, and expectations from AR. Responses of pediatricians and nurses/RTs were compared using Chi-square, with P < .05 considered significant.

Results

Response rate was 44/114(39%) (pediatricians), and 69/120 (58%) (nurses/RTs). Asked about methodological quality, most respondents expect that: AR is done to high quality; costs and difficulty are not acceptable justifications for low quality; findings should be reproducible between laboratories and strains of the same species; and guidelines for AR funded with public money should be consistent with these expectations. Asked about benefits of AR, most thought that there are sometimes/often large benefits to humans from AR, and disagreed that “AR rarely produces benefit to humans.” Asked about expectations of translation to humans (of toxicity, carcinogenicity, teratogenicity, and treatment findings), most: expect translation >40% of the time; thought that misleading AR results should occur <21% of the time; and that if translation was to occur <20% of the time, they would be less supportive of AR. There were few differences between pediatricians and nurses/RTs.

Conclusions

HCW have high expectations for the methodological quality of, and the translation rate to humans of findings from AR. These expectations are higher than the empirical data show having been achieved. Unless these areas of AR significantly improve, HCW support of AR may be tenuous.

Refinement of analgesia following thoracotomy and experimental myocardial infarction using the Mouse Grimace Scale

NEW FINDINGS

What is the central question of this study? There is an ethical imperative to optimize analgesia protocols for laboratory animals, but this is impeded by our inability to recognize pain reliably. We examined whether the Mouse Grimace Scale (MGS) provides benefits over a standard welfare scoring system for identifying a low level of pain in the frequently used murine surgical model of myocardial infarction. What is the main finding and its importance? Low-level pain, responsive to analgesia, was detected by MGS but not standard methods. In this model, most of the pain is attributable to the thoracotomy, excepted in mice with very large infarcts. This approach represents a model for assessing postsurgical analgesia in rodents. The Mouse Grimace Scale (MGS) was developed for assessing pain severity, but the general applicability to complex postsurgical pain has not been established. We sought to determine whether the MGS provides benefits over and above a standard welfare scoring system for identifying pain in mice following experimental myocardial infarction. Female C57BL/6J mice (n = 60), anaesthetized with isoflurane, were subjected to thoracotomy with ligation of a coronary artery or sham procedure. A single s.c. dose of buprenorphine (1.1 mg kg(-1) ) was given at the time of surgery and pain assessed at 24 h by MGS and a procedure-specific welfare scoring system. In some animals, a second dose of 0.6 mg kg(-1) buprenorphine was given and pain assessment repeated after 30 min. The MGS was scored from multiple photographs by two independent blinded observers with good correlation (r = 0.98). Using the average MGS score of both observers, we identified a subset of mice with low scores that were not considered to be in pain by the welfare scoring system or by single observer MGS. These mice showed a significant improvement with additional analgesia, suggesting that this low-level pain is real. Pain attributable to the myocardial injury, as opposed to thoracotomy, persisted at 24 h only in mice with large infarcts >40%. In conclusion, the use of a multi-observer, post hoc version of the MGS is a sensitive tool to assess the efficacy of postsurgical analgesic protocols. Following surgical induction of myocardial infarction, we identified a significant proportion of mice that were in low-level pain at 24 h that were not identified by other assessment methods.

Pain Management for Animals Used in Science: Views of Scientists and Veterinarians in Canada

Simple Summary

Veterinarians, veterinarian-scientists and scientists (all engaged in animal-based studies in Canada) were interviewed to explore the challenges and opportunities for laboratory animal pain management. Our broader aim was to contribute to further discussion of how pain can be minimized for animals used in science. Recognizing when animals are in pain continues to present a challenge, and there does not seem to be consensus on the signs of pain. Clarification of the interactions between scientific objectives and pain management are needed, as well as a stronger evidence base for pain management approaches. Detailed examination of pain management for individual invasive animal models in order to develop model-specific pain management protocols may be useful.

Abstract

To explore the challenges and opportunities for pain management for animals used in research an interview study with 9 veterinarians, 3 veterinarian-scientists and 9 scientists, all engaged in animal-based studies in Canada, was carried out. Our broader aim was to contribute to further discussion of how pain can be minimized for animals used in science. Diverse views were identified regarding the ease of recognizing when animals are in pain and whether animals hide pain. Evidence of inconsistencies in pain management across laboratories, institutions and species were also identified. Clarification of the interactions between scientific objectives and pain management are needed, as well as a stronger evidence base for pain management approaches. Detailed examination of pain management for individual invasive animal models may be useful, and may support the development of model-specific pain management protocols.