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Even when no other alternatives are available for scientific experiments, the use of research animals is still a difficult decision. To promote more ethical animal research, scientists must follow the 3Rs principle. Reduction is one of the 3Rs—it involves keeping the number of animals used to a minimum, by obtaining information from fewer animals or obtaining more information from the same number of animals. Imaging technologies allow scientists to see inside of the bodies of live animals without harming them, so that the animals do not need to be killed for scientists to study their organs. Using imaging techniques, scientists can study illness and responses to treatments. Animals can be imaged multiple times in long-term studies, so imaging techniques protect animal welfare by reducing the number of animals used in research.

Nurturing a culture of care remains a key strategy and needs to be well integrated in the education programmes for laboratory animal professionals. Addressing attitudes is a complex task that must ensure reflective learning approaches. Teaching strategies must facilitate a safe space to talk openly about emotions and caring responsibilities. We reflect on two training initiatives focusing on culture of care. Firstly, the ‘Care-full Stories’ tool, which uses fictionalised prompts (storytelling) to encourage participants to share their own stories from working in animal research. Feedback on its impact on establishing a safe space for sharing experiences and the importance of appreciating diverse perspectives between staff is discussed. Secondly, we provide feedback on the development of training approaches on animal research integrity and culture of care with low- middle-income international communities. Strategic targets addressing the multicultural diversity of the communities, recognising their specific needs and their access to resources, must be well defined. It is important to acknowledge the interconnection between people, animals and their shared natural environment when defining the culture of care concept and addressing the teaching approaches. We discuss both the positive outcomes and challenges of these two learning experiences to support innovation when planning tools for teaching culture of care. Accounting for ‘how’ and ‘where’ the training will be delivered remains key to its successful uptake and local sustainability. Supporting improved educational tools to ascertain why caring has an impact on our professional lives will have a direct impact on the wellbeing of laboratory animal professionals worldwide.

C-type natriuretic peptide (CNP) is highly expressed in the central nervous system (CNS) and key to neuronal development; however, a broader role for CNP in the CNS remains unclear. To address this deficit, we investigated behavioral, sensory and motor abnormalities and blood-brain barrier (BBB) integrity in a unique mouse model with inducible, global deletion of CNP (gbCNP–/–). gbCNP–/– mice and wild-type littermates at 12 (young adult) and 65 (aged) weeks of age were investigated for changes in gait and motor coordination (CatWalk™ and rotarod tests), anxiety-like behavior (open field and elevated zero maze tests), and motor and sensory function (modified neurological severity score [mNSS] and primary SHIRPA screen). Vascular permeability was assessed in vivo (Miles assay) with complementary in vitro studies conducted in primary murine brain endothelial cells. Young adult gbCNP–/– mice had normal gait but reduced motor coordination, increased locomotor activity in the open field and elevated zero maze, and had a higher mNSS score. Aged gbCNP–/– animals developed recurrent spontaneous seizures and had impaired gait and wide-ranging motor and sensory dysfunction. Young adult and aged gbCNP–/– mice exhibited increased BBB permeability, which was partially restored in vitro by CNP administration. Cultured brain endothelial cells from gbCNP–/– mice had an abnormal ZO-1 protein distribution. These data suggest that lack of CNP in the CNS impairs tight junction protein arrangement and increases BBB permeability, which is associated with changes in locomotor activity, motor coordination and late-onset seizures.

The use of animal in biomedical research remains a critical compromise. Research and higher education institutions play a major role in educating on the use of animal and such training is expected to translate into the development of a culture of care practice across all staff working with animals. But nurturing a “culture of care” and impacting in professional attitudes in the field of animal research remains challenging due to its social, ethical and different institutional frameworks. From an educational perspective, current practice remains challenged by the need for better integration of inter-cultural perceptions on animal welfare, supported by more cross disciplinary integration in educational curriculum including the relevance of the 3Rs principles and promoting reflective practice strategies. Institutional support is crucial to provide a safe, and supportive framework to promote such caring ethos. Our aim is to discuss practical actions to implement and assess culture of care, highlighting its direct impact on the professional integrity of staff which is directly linked to research and education excellence. Seeking a global welfare for all the beings involved and supporting individual and team reflective practice will provide better tools to guarantee the best care of the animals.

BackgroundTraumatic attacks from large feline predators cause a small yet significant burden of disease in rural populations, are increasing in frequency, cause complex injuries and worsen human–wildlife conflicts. Data on the traumatic injury pattern found in victims of these animals is sparse, and this study aimed to collate and synthesise patterns of injury to inform the care and management of these patients.MethodsA multi-ethnographic literature search (PubMed, Embase, Web of Science, Google Scholar, and other sources) was performed on 12/1/21 to capture all available data describing anatomical injury and the mechanism of injury sustained by humans from attacks by lions, leopards and tigers. Quality and bias assessment was performed using the Joanna Briggs Critical Evaluation tools.ResultsOf 5110 studies identified, 42 were included in this review totalling 84 individual patient cases. A total of 85% of fatal injuries were due to exsanguination combined with neuroaxis injury of the neck. All wounds were susceptible to tissue loss, infection and long-term neuro-vascular complications. Leopards injured anterior-midline structures of the neck more often than did lions and tigers, while the latter caused high-energy fractures. Time lag to treatment for survivors of wild attacks extended to multiple days, and occult injury was common.ConclusionIn addition to the primary finding of complex neck injury, this study generated specific patterns of injury seen from the included species and highlighted occult injury and healthcare disparity as challenges in providing patient care.

The relationships between individuals and the research animals they work with can enhance animal welfare, but they also involve a moral cost to staff. Securing a safe space to communicate openly about animal welfare & research and acknowledge its emotional impacts is crucial. In this Comment, we reflect on emotional resilience and provide resources available to help manage the emotional burden of working with laboratory animals.

The early detection of traumatic brain injuries can directly impact the prognosis and survival of patients. Preceding attempts to automate the detection and the assessment of the severity of traumatic brain injury continue to be based on clinical diagnostic methods, with limited tools for disease outcomes in large populations. Despite advances in machine and deep learning tools, current approaches still use simple trends of statistical analysis which lack generality. The effectiveness of deep learning to extract information from large subsets of data can be further emphasised through the use of more elaborate architectures. We therefore explore the use of a multiple input, convolutional neural network and long short-term memory (LSTM) integrated architecture in the context of traumatic injury detection through predicting the presence of brain injury in a murine preclinical model dataset. We investigated the effectiveness and validity of traumatic brain injury detection in the proposed model against various other machine learning algorithms such as the support vector machine, the random forest classifier and the feedforward neural network. Our dataset was acquired using a home cage automated (HCA) system to assess the individual behaviour of mice with traumatic brain injury or non-central nervous system (non-CNS) injured controls, whilst housed in their cages. Their distance travelled, body temperature, separation from other mice and movement were recorded every 15 minutes, for 72 hours weekly, for 5 weeks following intervention. The HCA behavioural data was used to train a deep learning model, which then predicts if the animals were subjected to a brain injury or just a sham intervention without brain damage. We also explored and evaluated different ways to handle the class imbalance present in the uninjured class of our training data. We then evaluated our models with leave-one-out cross validation. Our proposed deep learning model achieved the best performance and showed promise in its capability to detect the presence of brain trauma in mice.

Introduction In the UK, 17,000 people die from injury each year, with uncontrolled bleeding the most significant cause of preventable mortality. Acute Traumatic Coagulopathy (ATC) exacerbates bleeding through the failure of blood-clotting with accelerated clot breakdown that mechanistically is driven by activated Protein C (aPC). No targeted therapy to treat the underlying cause of ATC exists with treatment limited to blood component resuscitation and antifibrinolytic drugs to prevent premature clot breakdown. Method Two hundred fifty-four bleeding trauma patients had Factor V and aPC measured on arrival and during resuscitation. A preclinical ATC model was used to test the novel therapeutic recombinant Factor V (rFV), which is resistant to aPC mediated cleavage. Mice underwent combined injury and pressure controlled-blood loss with intervention at 30-minutes to represent a clinically relevant model. Coagulopathy was measured by ROTEM and biomarkers of coagulation/fibrinolysis. Result Admission levels of FV were 38% lower (83 vs 134u/dL, p Conclusion FV falls significantly during bleeding in trauma patients and in the murine model, rFV improved coagulation suggesting it may represent a potential therapeutic target for ATC. Take-home message Directly targeting the cause of ATC represents a novel therapeutic strategy in trauma and may improve survival after major haemorrhage by directly improving clot function.

Rationale: Traumatic brain injury (TBI) leads to neurological impairment, with no satisfactory treatments available. Classical ketogenic diets (KD), which reduce reliance on carbohydrates and provide ketones as fuel, have neuroprotective potential, but their high fat content reduces compliance, and experimental evidence suggests they protect juvenile brain against TBI, but not adult brain, which would strongly limit their applicability in TBI. Methods: We designed a new-KD with a fat to carbohydrate plus protein ratio of 2:1, containing medium chain triglycerides (MCT), docosahexaenoic acid (DHA), low glycaemic index carbohydrates, fibres and the ketogenic amino acid leucine, and evaluated its neuroprotective potential in adult TBI. Adult male C57BL6 mice were injured by controlled cortical impact (CCI) and assessed for 70 days, during which they received a control diet or the new-KD. Results: The new-KD, that markedly increased plasma Beta-hydroxybutyrate (β-HB), significantly attenuated sensorimotor deficits and corrected spatial memory deficit. The lesion size, perilesional inflammation and oxidation were markedly reduced. Oligodendrocyte loss appeared to be significantly reduced. TBI activated the mTOR pathway and the new-KD enhanced this increase and increased histone acetylation and methylation. Conclusion: The behavioural improvement and tissue protection provide proof of principle that this new formulation has therapeutic potential in adult TBI.

Sepsis is a major worldwide healthcare issue with unmet clinical need. Despite extensive animal research in this area, successful clinical translation has been largely unsuccessful. We propose one reason for this is that, sometimes, the experimental question is misdirected or unrealistic expectations are being made of the animal model. As sepsis models can lead to a rapid and substantial suffering – it is essential that we continually review experimental approaches and undertake a full harm:benefit impact assessment for each study. In some instances, this may require refinement of existing sepsis models. In other cases, it may be replacement to a different experimental system altogether, answering a mechanistic question whilst aligning with the principles of reduction, refinement and replacement (3Rs). We discuss making better use of patient data to identify potentially useful therapeutic targets which can subsequently be validated in preclinical systems. This may be achieved through greater use of construct validity models, from which mechanistic conclusions are drawn. We argue that such models could provide equally useful scientific data as face validity models, but with an improved 3Rs impact. Indeed, construct validity models may not require sepsis to be modelled, per se. We propose that approaches that could support and refine clinical translation of research findings, whilst reducing the overall welfare burden on research animals.

The targeted delivery of therapies to diseased tissues offers a safe opportunity to achieve optimal efficacy while limiting systemic exposure. These considerations apply to many disease indications but are especially relevant for rheumatoid arthritis (RA), as RA is a systemic autoimmune disease which affects multiple joints. We have identified an antibody that is specific to damaged arthritic cartilage (anti-ROS-CII) that can be used to deliver treatments specifically to arthritic joints, yielding augmented efficacy in experimental arthritis. In the current study, we demonstrate that scaffolds enriched with bioactive payloads can be delivered precisely to an inflamed joint and achieve superior efficacy outcomes consistent with the pharmacological properties of these payloads. As a scaffold, we have used extracellular vesicles (EVs) prepared from human neutrophils (PMNs), which possess intrinsic anti-inflammatory properties and the ability to penetrate inflamed arthritic cartilage. EV fortified with anti-ROS-CII (EV/anti-ROS-CII) retained anti-ROS-CII specificity and bound exclusively to the damaged cartilage. Following systemic administration, EV/anti-ROS-CII (a) exhibited the ability to localize specifically in the arthritic joint in vivo and (b) was able to specifically target single (viral IL-10 or anti-TNF) or combined (viral IL-10 and anti-TNF) anti-inflammatory treatments to the arthritic joint, which accelerated attenuation of clinical and synovial inflammation. Overall, this study demonstrates the attainability of targeting a pro-resolving biological scaffold to the arthritic joint. The potential of targeting scaffolds such as EV, nanoparticles, or a combination thereof alongside combined therapeutics is paramount for designing systemically administered broad-spectrum of anti-inflammatory treatments.

Cardiac dysfunction (CD) importantly contributes to mortality in trauma patients, who survive their initial injuries following successful hemostatic resuscitation. This poor outcome has been correlated with elevated biomarkers of myocardial injury, but the pathophysiology triggering this CD remains unknown. We investigated the pathophysiology of acute CD after trauma using a mouse model of trauma hemorrhage shock (THS)-induced CD with echocardiographic guidance of fluid resuscitation, to assess the THS impact on myocardial integrity and function. Mice were subjected to trauma (soft tissue and bone fracture) and different degrees of hemorrhage severity (pressure controlled ~MABP < 35 mmHg or

Traumatic brain injury (TBI) can lead to life-changing neurological deficits, which reflect the fast-evolving secondary injury post-trauma. There is a need for acute protective interventions, and the aim of this study was to explore in an experimental TBI model the neuroprotective potential of a single bolus of a neuroactive omega-3 fatty acid, docosahexaenoic acid (DHA), administered in a time window feasible for emergency services. Adult mice received a controlled cortical impact injury (CCI) and neurological impairment was assessed with the modified Neurological Severity Score (mNSS) up to 28 days post-injury. DHA (500 nmol/kg) or saline were injected intravenously at 30 min post-injury. The lipid mediator profile was assessed in the injured hemisphere at 3 h post-CCI. After completion of behavioral tests and lesion assessment using magnetic resonance imaging, over 7 days or 28 days post-TBI, the tissue was analyzed by immunohistochemistry. The single DHA bolus significantly reduced the injury-induced neurological deficit and increased pro-resolving mediators in the injured brain. DHA significantly reduced lesion size, the microglia and astrocytic reaction, and oxidation, and decreased the accumulation of beta-amyloid precursor protein (APP), indicating a reduced axonal injury at 7 days post-TBI. DHA reduced the neurofilament light levels in plasma at 28 days. Therefore, an acute single bolus of DHA post-TBI, in a time window relevant for acute emergency intervention, can induce a long-lasting and significant improvement in neurological outcome, and this is accompanied by a marked upregulation of neuroprotective mediators, including the DHA-derived resolvins and protectins.

Purpose Traumatic spinal cord injury (SCI) is a devastating condition which affects millions of people worldwide causing major disability and substantial socioeconomic burden. There are currently no effective treatments. Modulating the neuroinflammatory (NI) response after SCI has evolved as a major therapeutic strategy. PET can be used to detect the upregulation of the 18-kDa translocator protein (TSPO), a hallmark of activated microglia in the CNS. We investigated whether PET imaging using the novel TSPO tracer [18F]GE-180 can be used as a clinically relevant biomarker for NI in a contusion SCI rat model, and we present data on the modulation of NI by the lipid docosahexaenoic acid (DHA). Methods A total of 22 adult male Wistar rats were subjected to controlled spinal cord contusion at the T10 spinal cord level. Six non-injured and ten T10 laminectomy only (LAM) animals were used as controls. A subset of six SCI animals were treated with a single intravenous dose of 250 nmol/kg DHA (SCI-DHA group) 30 min after injury; a saline-injected group of six animals was used as an injection control. PET and CT imaging was carried out 7 days after injury using the [18F]GE-180 radiotracer. After imaging, the animals were killed and the spinal cord dissected out for biodistribution and autoradiography studies. In vivo data were correlated with ex vivo immunohistochemistry for TSPO. Results In vivo dynamic PET imaging revealed an increase in tracer uptake in the spinal cord of the SCI animals compared with the non-injured and LAM animals from 35 min after injection (P

SummaryBlood flow generates wall shear stress (WSS) which alters endothelial cell (EC) function. Low WSS promotes vascular inflammation and atherosclerosis whereas high uniform WSS is protective. Ivabradine decreases heart rate leading to altered haemodynamics. Besides its cardio-protective effects, ivabradine protects arteries from inflammation and atherosclerosis via unknown mechanisms. We hypothesised that ivabradine protects arteries by increasing WSS to reduce vascular inflammation. Hypercholesterolaemic mice were treated with ivabradine for seven weeks in drinking water or remained untreated as a control. En face immunostaining demonstrated that treatment with ivabradine reduced the expression of pro-inflammatory VCAM-1 (p

Traumatic brain injury (TBI) leads to cellular loss, destabilization of membranes, disruption of synapses and altered brain connectivity, and increased risk of neurodegenerative disease. A significant and long-lasting decrease in phospholipids (PLs), essential membrane constituents, has recently been reported in plasma and brain tissue, in human and experimental TBI. We hypothesized that supporting PL synthesis post-injury could improve outcome post-TBI. We tested this hypothesis using a multi-nutrient combination designed to support the biosynthesis of PLs and available for clinical use. The multi-nutrient, Fortasyn® Connect (FC), contains polyunsaturated omega-3 fatty acids, choline, uridine, vitamins, cofactors required for PL biosynthesis, and has been shown to have significant beneficial effects in early Alzheimer's disease. Male C57BL/6 mice received a controlled cortical impact injury and then were fed a control diet or a diet enriched with FC for 70 days. FC led to a significantly improved sensorimotor outcome and cognition, reduced lesion size and oligodendrocyte loss, and it restored myelin. It reversed the loss of the synaptic protein synaptophysin and decreased levels of the axon growth inhibitor, Nogo-A, thus creating a permissive environment. It decreased microglia activation and the rise in ß-amyloid precursor protein and restored the depressed neurogenesis. The effects of this medical multi-nutrient suggest that support of PL biosynthesis post-TBI, a new treatment paradigm, has significant therapeutic potential in this neurological condition for which there is no satisfactory treatment. The multi-nutrient tested has been used in dementia patients and is safe and well tolerated, which would enable rapid clinical exploration in TBI.

The use of imaging represents a major impact on the refinement and the reduction of in vivo studies in animal models, in particular for allowing longitudinal monitoring of the onset and the progression of disease within the same animal, and studying the biological effects of drug candidate and their therapeutic effectiveness. But the use of imaging procedures can affect animal physiology, and the need to anesthetize the animals for imaging entails potential health risks. During anesthesia, there is an inevitable autonomic nervous system depression which induces cardiovascular depression, respiratory depression, and hypothermia. Also other procedures associated with imaging such as animal preparation (e.g., fasting, premedication), blood sampling, and dosage/contrast agent injections can also affect physiology and animal welfare. All these factors are likely to have confounding effect on the outcome of the imaging studies and pose important concerns regarding the animal's well-being, particularly when imaging immune deprived animals or diseased animals. We will discuss these challenges and considerations during imaging to maximize efficacious data while promoting animal welfare.

The use of imaging represents a major impact on the refinement and the reduction of in vivo studies in animal models, in particular for allowing longitudinal monitoring of the onset and the progression of disease within the same animal, and studying the biological effects of drug candidate and their therapeutic effectiveness. But the use of imaging procedures can affect animal physiology, and the need to anesthetize the animals for imaging entails potential health risks. During anesthesia, there is an inevitable autonomic nervous system depression which induces cardiovascular depression, respiratory depression, and hypothermia. Also other procedures associated with imaging such as animal preparation (e.g., fasting, premedication), blood sampling, and dosage/contrast agent injections can also affect physiology and animal welfare. All these factors are likely to have confounding effect on the outcome of the imaging studies and pose important concerns regarding the animal's well-being, particularly when imaging immune deprived animals or diseased animals. We will discuss these challenges and considerations during imaging to maximize efficacious data while promoting animal welfare.

Trauma is responsible for a large proportion of the world's burden of disease, and is by far the biggest killer of young adults. Hemorrhage is the leading cause of preventable death and its effects are directly correlated with the incidence multi-organ failure in survivors. Trauma research is challenging due to patient heterogeneity, limited randomized controlled trials, and in vitro studies that fail to mimic the systemic injury response. Preclinical research remains essential for mechanistic and therapeutic discovery. Yet modeling the multifaceted nature of traumatic injury poses important experimental and welfare challenges associated with the onset of injury and prehospital and intra-operative care, the limited inter-species validation of coagulation profiles, the use of anesthesia/analgesia, and its impact on the systemic response to trauma; and the challenge of sustaining intensive care in recovery models. Proper model selection depends on the purpose of a given model and the criteria by which the experimental readouts will be clinically relevant. Such complexity warrants further refinement of experimental methodology and outcome measures to improve its clinical efficacy, while ensuring animal well-being. We review the experimental methodologies currently used for modeling traumatic hemorrhagic shock and addressing their impact on clinical translation. The aim of the review is to improve transparency and form a consensus when reporting methodology in trauma modeling.

OBJECTIVE: Identification of patients with high-risk asymptomatic carotid plaques remains an elusive but essential step in stroke prevention. Inflammation is a key process in plaque destabilization and a prelude to clinical sequelae. There are currently no clinical imaging tools to assess the inflammatory activity within plaques. This study characterized inflammation in atherosclerosis using dual-targeted microparticles of iron oxide (DT-MPIO) as a magnetic resonance imaging (MRI) probe. METHODS: DT-MPIO were used to detect and characterize inflammatory markers, vascular cell adhesion molecule 1 (VCAM-1). and P-selectin on (1) tumor necrosis factor-α-treated cells by immunocytochemistry and (2) aortic root plaques of apolipoprotein-E deficient mice by in vivo MRI. Furthermore, apolipoprotein E-deficient mice with focal carotid plaques of different phenotypes were developed by means of periarterial cuff placement to allow in vivo molecular MRI using these probes. The association between biomarkers and the magnetic resonance signal in different contrast groups was assessed longitudinally in these models. RESULTS: Immunocytochemistry confirmed specificity and efficacy of DT-MPIO to VCAM-1 and P-selectin. Using this in vivo molecular MRI strategy, we demonstrated (1) the DT-MPIO-induced magnetic resonance signal tracked with VCAM-1 (r = 0.69; P = .014), P-selectin (r = 0.65; P = .022), and macrophage content (r = 0.59; P = .045) within aortic root plaques and (2) high-risk inflamed plaques were distinguished from noninflamed plaques in the murine carotid artery within a practical clinical imaging time frame. CONCLUSIONS: These molecular MRI probes constitute a novel imaging tool for in vivo characterization of plaque vulnerability and inflammatory activity in atherosclerosis. Further development and translation into the clinical arena will facilitate more accurate risk stratification in carotid atherosclerotic disease in the future.

Traumatic brain injury (TBI) is currently a major cause of morbidity and poor quality of life in Western society, with an estimate of 2.5 million people affected per year in Europe, indicating the need for advances in TBI treatment. Within the first 24 h after TBI, several inflammatory response factors become upregulated, including the lectin galectin-3. In this study, using a controlled cortical impact (CCI) model of head injury, we show a large increase in the expression of galectin-3 in microglia and also an increase in the released form of galectin-3 in the cerebrospinal fluid (CSF) 24 h after head injury. We report that galectin-3 can bind to TLR-4, and that administration of a neutralizing antibody against galectin-3 decreases the expression of IL-1β, IL-6, TNFα and NOS2 and promotes neuroprotection in the cortical and hippocampal cell populations after head injury. Long-term analysis demonstrated a significant neuroprotection in the cortical region in the galectin-3 knockout animals in response to TBI. These results suggest that following head trauma, released galectin-3 may act as an alarmin, binding, among other proteins, to TLR-4 and promoting inflammation and neuronal loss. Taking all together, galectin-3 emerges as a clinically relevant target for TBI therapy., A.C.-J. is supported by a pre-doctoral fellowship from Spanish Ministerio de Educación, Cultura y Deporte. This work has been supported by grants from the Spanish Ministerio SAF2015–64171R (MINECO/FEDER, UE), Blizard Research Theme grants, Blizard Institute, Queen Mary University of London. M.A.B has been funded by the Barts Charity Centre for Trauma Sciences (C4TS) and the Wellcome Trust Institutional Strategic Support Fund (ISSF).

Molecular imaging has witnessed a tremendous change over the last decade. Growing interest and emphasis are placed on this specialized technology represented by developing new scanners, pharmaceutical drugs, diagnostic agents, new therapeutic regimens, and ultimately, significant improvement of patient health care. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) have their signature on paving the way to molecular diagnostics and personalized medicine. The former will be the topic of the current paper where the authors address the current position of the molecular SPECT imaging among other imaging techniques, describing strengths and weaknesses, differences between SPECT and PET, and focusing on different SPECT designs and detection systems. Radiopharmaceutical compounds of clinical as well-preclinical interest have also been reviewed. Moreover, the last section covers several application, of SPECT imaging in many areas of disease detection and diagnosis.

Traumatic brain injury (TBI) results in direct vascular disruption, triggering edema, and reduction in cerebral blood flow. Therefore, understanding the pathophysiology of brain microcirculation following TBI is important for the development of effective therapies. Optical coherence angiography (OCA) is a promising tool for evaluating TBI in rodent models. We develop an approach to OCA that uses the heart-rate frequency to discriminate between static tissue and vasculature. This method operates on intensity data and is therefore not phase sensitive. Furthermore, it does not require spatial overlap of voxels and thus can be applied to pre-existing datasets for which oversampling may not have been explicitly considered. Heart-rate sensitive OCA was developed for dynamic assessment of mouse microvasculature post-TBI. Results show changes occurring at 5-min intervals within the first 50 min of injury.

Formyl Peptide Receptors (FPRs) are vital in the host inflammatory response, playing an important regulatory role in multiple diseases. A Gd(III) DOTA conjugate of cFLFLFK has been synthesised which targets and visualises FPR1 upon leukocytes in the inflammatory response via magnetic resonance imaging for the first time.

Imaging technologies are regularly used in biomedical research to study processes in living animals in a noninvasive manner. But imaging procedures can affect animal physiology, and the need to anesthetize animals for imaging entails potential health risks. In addition, certain imaging modalities require the use of ionizing radiation or the administration of contrast agents or imaging biomarkers, which also have consequences for animal physiology. Finally, procedures associated with imaging, such as animal preparation (e.g., fasting, premedication) and blood sampling, can also affect physiology and animal welfare. Here, the authors review the imaging modalities commonly used for rodents in biomedical research and their associated considerations for animal welfare.

Noninvasive imaging methods are required to monitor the inflammatory content of atherosclerotic plaques. FEDAA1106 (N-(5-fluoro2-phenoxyphenyl)-N-(2-(2-fluoroethoxy)-5-methoxybenzyl) acetamide) is a selective ligand for TSPO-18kDa (also known as peripheral benzodiazepine receptor), which is expressed by activated macrophages. We compared 18 F-FEDAA1106 and 2-deoxy-2-[ 18 F]fluoro-Dglucose ( 18 F-FDG, a marker of glucose metabolism) for positron emission tomographic (PET) imaging of vascular inflammation. This was tested using a murine model in which focal inflammation was induced in the carotid artery via placement of a constrictive cuff. Immunostaining revealed CD68-positive cells (macrophages) at a disturbed flow site located downstream from the cuff. Dynamic PET imaging using 18 F-FEDAA1106 or 18 F-FDG was registered to anatomic data generated by computed tomographic (CT)/CT angiography. Standardized uptake values were significantly increased at cuffed compared to contralateral arteries using either 18 F-FEDAA1106 (p , .01) or FDG (p , .05). However, the 18 F-FEDAA1106 signal was significantly higher at the inflamed disturbed flow region compared to the noninflamed uniform flow regions, whereas differences in FDG uptake were less distinct. We conclude that 18 F-FEDAA1106 can be used in vivo for detection of vascular inflammation. Moreover, the signal pattern of 18 F-FEDAA1106 corresponded with vascular inflammation more specifically than FDG uptake.

Mice are widely used to investigate atherogenesis, which is known to be influenced by stresses related to blood flow. However, numerical characterization of the haemodynamic environment in the commonly studied aortic arch has hitherto been based on idealizations of inflow into the aorta. Our purpose in this work was to numerically characterize the haemodynamic environment in the mouse aortic arch using measured inflow velocities, and to relate the resulting shear stress patterns to known locations of high- and low-lesion prevalence. Blood flow velocities were measured in the aortic root of C57/BL6 mice using phase-contrast MRI. Arterial geometries were obtained by micro-CT of corrosion casts. These data were used to compute blood flow and wall shear stress (WSS) patterns in the arch. WSS profiles computed using realistic and idealized aortic root velocities differed significantly. An unexpected finding was that average WSS in the high-lesion-probability region on the inner wall was actually higher than the WSS in the low-probability region on the outer wall. Future studies of mouse aortic arch haemodynamics should avoid the use of idealized inflow velocity profiles. Lesion formation does not seem to uniquely associate with low or oscillating WSS in this segment, suggesting that other factors may also play a role in lesion localization.

A reproducible Roux-en-Y gastric bypass (RYGB) model in mice is needed to study the physiological alterations after surgery. Male C57BL6 mice weighing 29.0 ± 0.8 g underwent either RYGB (n = 14) or sham operations (n = 6). RYGB surgery consisted of a small gastric pouch (~2 % of the initial stomach size), a biliopancreatic and alimentary limb of 10 cm each and a common channel of 15 cm. Animals had free access to standard chow in the postoperative period. Body mass and food intake were recorded for 60 days. Bomb calorimetry was used for faecal analysis. Anatomical rearrangement was assessed using planar X-ray fluoroscopy and computed tomography (CT) after oral Gastrografin® injection. RYGB surgery led to a sustained reduction in body weight compared to sham-operated mice (postoperative week 1: sham 27.8 ± 0.7 g vs. RYGB 26.5 ± 1.0 g, p = 0.008; postoperative week 8: sham 30.7 ± 0.8 g vs. RYGB 28.4 ± 1.1 g, p = 0.003). RYGB mice ate less compared to shams (sham 4.6 ± 0.2 g/day vs. RYGB 4.3 ± 0.4 g/day, p

Atherosclerotic lesions have a highly non-uniform distribution in regions of arterial branching and curvature, consistent with hemodynamic factors, in particular wall shear stress (WSS), controlling their development. The widespread and increasing use of the mouse as a model for studying atherosclerosis has encouraged investigation of the hemodynamics of the mouse aortic arch [1–3], in which previous studies have revealed areas of high and low lesion prevalence and variation in the expression of pro-atherogenic molecules [4]. Our previous computational simulations [1–2] did not produce distributions of WSS that explain the pattern of lesions. We are currently investigating whether incorporation of more realistic aortic root velocity measurements, obtained using phase-contrast magnetic resonance imaging (PC-MRI), into these simulations can improve the correlation with disease. Here we present velocities obtained by PC-MRI and preliminary simulations employing the data.