Animal Research Research Articles

The evaluation of atorvastatin as an adjunct to fluconazole for the anti-fungal prophylaxis in acute myeloid leukemia: a multicenter, triple-blinded, randomized clinical trial.

The development of invasive fungal infections (IFIs) is a serious complication in acute myeloid leukemia (AML) patients who undergo an induction to remission chemotherapy. Given the increased mortality in AML patients with IFI despite prophylaxis, we need to address this problem. Statins have traditionally been employed in clinical settings as agents for reducing lipid levels. Nonetheless, recent investigations have brought to light their antifungal properties in animals, as well as in vitro studies. The objective of this study was to assess the effectiveness of atorvastatin when added to the routine IFI prophylaxis regimen in patients diagnosed with AML. A randomized, multicenter, triple-blind study was conducted on 76 AML patients aged 18-70, who received either placebo or atorvastatin in addition to fluconazole. Patients were followed for 30days in case of developing IFIs, patient survival, and atorvastatin- related adverse drug reactions. Data were analyzed with SPSS version 26.0. A level of significance of 0.05 was utilized as the threshold for all statistical tests. The data were analyzed by adjusting for the effect of age, regarding that there was a significant difference between the two groups, and showed that atorvastatin reduced the development of both probable and proven IFI (based on EORTC/MSGERC criteria) compared to placebo. IFI-free survival was also significantly better in the atorvastatin group. The incidence of developing aspergillosis did not differ between the two groups. No serious adverse events related to atorvastatin were observed. The present investigation has substantiated the antecedent in vitro and animal research on the fungicidal impact of statins and has suggested the need for additional research involving larger sample sizes and an extended duration of follow-up. Trial registration: This study was registered on the Iranian registry of clinical trials as IRCT20210503051166N1 (Date of confirmation 2021.05.03).

A novel minimally invasive fixation method for flail chest management in a Canine model: an animal research

BackgroundMultiple rib fractures can lead to flail chest with up to 35% mortality rate due to severe pulmonary complications. Current treatments of flail chest remain controversial. Studies have shown that surgical treatments can improve outcomes and reduce mortality, comparing to non-operative treatments. Current surgical fixation methods focus on stabilization of ribs on the outward facing side, and they require division of intercostal muscles. Damages to surrounding nerves and vessels may lead to chronic pain. This study tests a novel interior fixation method that minimizes neurovascular injuries.MethodsTwelve healthy canines were divided in two surgical operation groups for exterior and interior fixation using titanium metal plates. Osteotomy with oblique fractures was prepared under general anesthesia. Exterior fixation was performed in open surgery. Interior fixation was minimally invasive using custom made tools including a flexible shaft extension screwdriver, solid plate stand, guiding wire loop and metal plates with threaded holes.ResultsRespiratory and cardiovascular functions (RR, PO2, PCO2, SpO2, and HR) together with body temperature were measured before anesthesia and within 48 h after surgery. The difference in measurements was not statistically significant between the two groups before surgery with P values greater than 0.05. However, the interior group canines had better RR and PO2 values starting from the 24th hour, and better PCO2, SpO2, and HR values starting from the 48th hour. It took longer operation time to complete the minimally invasive interior fixation surgery (P value less than 0.001), but the total blood loss was less than the exterior fixation group (P value less than 0.001). Results also showed that interior group canines suffered less pain, and they had quicker recovery in gastrointestinal and physical mobility.ConclusionsThe investigative interior fixation method was safe and effective in rib stabilization on a canine rib fracture model, comparing to the exterior fixation method. The interior fixation was minimally invasive, with less damages to tissues and nerves surrounding the ribs, leading to better postoperative outcomes.

The endorsement of general and artificial intelligence reporting guidelines in radiological journals: a meta-research study

BackgroundComplete reporting is essential for clinical research. However, the endorsement of reporting guidelines in radiological journals is still unclear. Further, as a field extensively utilizing artificial intelligence (AI), the adoption of both general and AI reporting guidelines would be necessary for enhancing quality and transparency of radiological research. This study aims to investigate the endorsement of general reporting guidelines and those for AI applications in medical imaging in radiological journals, and explore associated journal characteristic variables.MethodsThis meta-research study screened journals from the Radiology, Nuclear Medicine & Medical Imaging category, Science Citation Index Expanded of the 2022 Journal Citation Reports, and excluded journals not publishing original research, in non-English languages, and instructions for authors unavailable. The endorsement of fifteen general reporting guidelines and ten AI reporting guidelines was rated using a five-level tool: “active strong”, “active weak”, “passive moderate”, “passive weak”, and “none”. The association between endorsement and journal characteristic variables was evaluated by logistic regression analysis.ResultsWe included 117 journals. The top-five endorsed reporting guidelines were CONSORT (Consolidated Standards of Reporting Trials, 58.1%, 68/117), PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses, 54.7%, 64/117), STROBE (STrengthening the Reporting of Observational Studies in Epidemiology, 51.3%, 60/117), STARD (Standards for Reporting of Diagnostic Accuracy, 50.4%, 59/117), and ARRIVE (Animal Research Reporting of In Vivo Experiments, 35.9%, 42/117). The most implemented AI reporting guideline was CLAIM (Checklist for Artificial Intelligence in Medical Imaging, 1.7%, 2/117), while other nine AI reporting guidelines were not mentioned. The Journal Impact Factor quartile and publisher were associated with endorsement of reporting guidelines in radiological journals.ConclusionsThe general reporting guideline endorsement was suboptimal in radiological journals. The implementation of reporting guidelines for AI applications in medical imaging was extremely low. Their adoption should be strengthened to facilitate quality and transparency of radiological study reporting.

Machine Learning-Derived Active Sleep as an Early Predictor of White Matter Development in Preterm Infants.

White matter dysmaturation is commonly seen in preterm infants admitted to the neonatal intensive care unit (NICU). Animal research has shown that active sleep is essential for early brain plasticity. This study aimed to determine the potential of active sleep as an early predictor for subsequent white matter development in preterm infants. Using heart and respiratory rates routinely monitored in the NICU, we developed a machine learning-based automated sleep stage classifier in a cohort of 25 preterm infants (12 females). The automated classifier was subsequently applied to a study cohort of 58 preterm infants (31 females) to extract active sleep percentage over 5-7 consecutive days during 29-32 weeks of postmenstrual age. Each of the 58 infants underwent high-quality T2-weighted magnetic resonance brain imaging at term-equivalent age, which was used to measure the total white matter volume. The association between active sleep percentage and white matter volume was examined using a multiple linear regression model adjusted for potential confounders. Using the automated classifier with a superior sleep classification performance [mean area under the receiver operating characteristic curve (AUROC) = 0.87, 95% CI 0.83-0.92], we found that a higher active sleep percentage during the preterm period was significantly associated with an increased white matter volume at term-equivalent age [β = 0.31, 95% CI 0.09-0.53, false discovery rate (FDR)-adjusted p-value = 0.021]. Our results extend the positive association between active sleep and early brain development found in animal research to human preterm infants and emphasize the potential benefit of sleep preservation in the NICU setting.

Calcium and vitamin D homoeostasis in male fertility.

Calcium and vitamin D have well-established roles in maintaining calcium balance and bone health. Decades of research in human subjects and animals have revealed that calcium and vitamin D also have effects on many other organs including male reproductive organs. The presence of calcium-sensing receptor, vitamin D receptor, vitamin D activating and inactivating enzymes and calcium channels in the testes, male reproductive tract and human spermatozoa suggests that vitamin D and calcium may modify male reproductive function. Functional animal models have shown that vitamin D deficiency in male rodents leads to a decrease in successful mating and fewer pregnancies, often caused by impaired sperm motility and poor sperm morphology. Human studies have to a lesser extent validated these findings; however, newer studies suggest a positive effect of vitamin D supplementation on semen quality in cases with vitamin D deficiency, which highlights the need for initiatives to prevent vitamin D deficiency. Calcium channels in male reproductive organs and spermatozoa contribute to the regulation of sperm motility and capacitation, both essential for successful fertilisation, which supports a need to avoid calcium deficiency. Studies have demonstrated that vitamin D, as a regulator of calcium homoeostasis, influences calcium influx in the testis and spermatozoa. Emerging evidence suggests a potential link between vitamin D deficiency and male infertility, although further investigation is needed to establish a definitive causal relationship. Understanding the interplay between vitamin D, calcium and male reproductive health may open new avenues for improving fertility outcomes in men.

The Effect of Intrahepatic and Intrasplenic Administration of Mesenchymal Stem Cell to Liver Function and Degree of Liver Fibrosis in Common Bile Duct Ligation Model in Rabbit

BackgroundMesenchymal stem cells (MSC) is a promising alternative method in liver cirrhosis management. Several administration routes of MSC have been studied, but few studies compared one to another. The purpose of this study is to compare the intrahepatic and intrasplenic route of MSC administration in terms of liver function and degree of liver fibrosis in the bile duct ligation model in rabbits. MethodExperimental study was conducted using rabbits (Oryctolagus cuniculus) model undergoing bile duct ligation (BDL). The subjects were randomized into 4 groups: sham surgery; bile duct ligation; bile duct ligation followed by intrahepatic route of MSC (BDL + IH MSC), and bile duct ligation followed by intrasplenic route of MSC (BDL + IS MSC). Umbilical cord mesenchymal stem cell (UC MSC) was administered on the fifth day after bile duct ligation, and the subjects were observed until the fourteenth day after bile duct ligation. The liver function was evaluated with alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total and direct bilirubin. The degree of fibrosis was evaluated with Laennec score, fibrosis area fraction, the number of viable and necrosis hepatocytes, and the number of hepatic progenitor cells. ResultThe subjects were randomized into 4 groups: 2 in sham surgery group, and 7 in each of the following groups: BDL, BDL + IH MSC and BDL + IS MSC groups. The mortality rate in BDL group was 57.1 %, while mortality in BDL + IH MSC and BDL + IS MSC groups were 14.3 % and 28.6 % respectively. No significant difference was found regarding liver function in each group, such as AST, ALT, total, and direct bilirubin. Histopathology examination in almost every subject undergone bile duct ligation (regardless of MSC administration) showed degree of fibrosis of Laennec 4B. Fibrosis area fraction, the number of viable and necrotic hepatocytes, and progenitor cells were analyzed; no significant difference was found between BDL + IH MSC and BDL + IS MSC groups, but the groups administered with MSC showed a larger number of viable hepatocytes compared to BDL group. No difference was found between BDL + IH MSC and BDL + IS MSC groups in terms of liver function and histologic parameters. ConclusionAdministration of MSC increases the number of viable hepatocytes, but no difference was found in terms of liver function and degree of liver fibrosis between the intrahepatic route and intrasplenic route of administration. Type of StudyAnimal Research, Randomized Controlled Study. Level of EvidenceLevel I? (animal research is not indicated in the levels of evidence table in the journal website).

Postnatal acetaminophen exposure and neurodevelopmental outcomes at 18-21 months corrected gestational age in preterm infants

Studies have reported prenatal acetaminophen exposure is associated with abnormal neurodevelopment. There is limited and conflicting data on neurodevelopmental outcomes following postnatal acetaminophen exposure. Our objective was to investigate the neurodevelopmental outcomes of preterm infants < 29 weeks gestation postnatally exposed to acetaminophen. Retrospective cohort study of infants born between 2008 and 2017 at a tertiary care perinatal center. Exclusion criteria included chromosomal disorders, major congenital abnormalities, and congenital infections. The primary outcome was a composite score of <85 on the cognitive, language, or motor components of the Bayley Scales of Infant and Toddler Development, 3rd edition, assessed at 18 to 21 months corrected gestational age. Multivariate logistic regression was used to assess confounders. Of the 945 infants included in the study, 120 were in the acetaminophen group. There was no difference in any of Bayley-III cognitive, language or motor composite scores of < 85 between the two groups for postnatal acetaminophen exposure, adjusted odds ratios (aORs) 1.03, 95% CI 0.60-1.78, or days of acetaminophen use, aORs 1.10, 95% CI 0.93-1.29. There was no difference in neurodevelopmental outcome between the acetaminophen exposed and non-exposed groups. Our results need validation in larger cohorts. Animal research and cohort studies have suggested that prenatal acetaminophen exposure may be associated with an elevated risk of neurobehavioral abnormalities. However, there is limited and conflicting research on the impact of postnatal acetaminophen on neurodevelopment. The results of this study suggest that postnatal acetaminophen does not negatively impact neurodevelopment at 18 to 21 months in preterm infants born at <29 weeks gestational age. While these results need validation in larger and more longitudinal studies, this study provides reassurance for the use of postnatal acetaminophen in extremely preterm infants.

Animal Ghosts at Canadian Universities: The Politics of Concealment and Transparency.

For many years, the lives of animals used for research in Canadian universities have been hidden from public view due both to physical concealment (e.g., security procedures and impenetrable labs) and administrative concealment (non-disclosure of information). Their lives unfold out of sight both physically and discursively, unavailable to the Canadian public for ethical consideration and democratic oversight. Recently, in response to calls by the public to end this secrecy, Canadian universities and the Canadian Council on Animal Care have embraced the language of "transparency" and have begun releasing documentation about animal research practices and procedures. This paper argues that this new "transparency" acts as its own kind of concealment practice, obscuring and displacing meaningful information while constructing highly selective ways of seeing animals in science, and manufacturing acquiescence/consent on the part of the public.

GARP and EARP are required for efficient BoHV-1 replication as identified by a genome wide CRISPR knockout screen.

The advances in gene editing bring unprecedented opportunities in high throughput functional genomics to animal research. Here we describe a genome wide CRISPR knockout library, btCRISPRko.v1, targeting all protein coding genes in the cattle genome. Using it, we conducted genome wide screens during Bovine Herpes Virus type 1 (BoHV-1) replication and compiled a list of pro-viral and anti-viral candidates. These candidates might influence multiple aspects of BoHV-1 biology such as viral entry, genome replication and transcription, viral protein trafficking and virion maturation in the cytoplasm. Some of the most intriguing examples are VPS51, VPS52 and VPS53 that code for subunits of two membrane tethering complexes, the endosome-associated recycling protein (EARP) complex and the Golgi-associated retrograde protein (GARP) complex. These complexes mediate endosomal recycling and retrograde trafficking to the trans Golgi Network (TGN). Simultaneous loss of both complexes in MDBKs resulted in greatly reduced production of infectious BoHV-1 virions. We also found that viruses released by these deficient cells severely lack VP8, the most abundant tegument protein of BoHV-1 that are crucial for its virulence. In combination with previous reports, our data suggest vital roles GARP and EARP play during viral protein packaging and capsid re-envelopment in the cytoplasm. It also contributes to evidence that both the TGN and the recycling endosomes are recruited in this process, mediated by these complexes. The btCRISPRko.v1 library generated here has been controlled for quality and shown to be effective in host gene discovery. We hope it will facilitate efforts in the study of other pathogens and various aspects of cell biology in cattle.

"Blind men and an elephant": The need for animals in research, drug safety studies, and understanding civilizational diseases.

Animal-based research and drug safety studies are essential to understanding the mysteries of nature and the long-term survival of humans. Due to the rapid increase in the global human population, conflict- and economically driven human migration, tourism-related activities, densely populated metropolitan areas, and local policies, humans will be affected by a multitude of novel disease-causing microorganisms and civilizational diseases. Despite disparities among countries, recent and planned changes in regulations concerning animal research and drug safety studies could have detrimental effects on both the animal research community and nations lacking sufficient social support systems. Based on existing scientific literature, I argue that we need animal research encompassing aspects such as animal development, behavior, drug safety studies, and for the understanding of future civilizational diseases. Depending on the nature of the research questions and local challenges, a suitable animal model organism should be made mandatory.

Front Matter Livestock and Animal Research Vol. 21 No. 3, November 2023

Front Matter Livestock and Animal Research Vol. 21 No. 3, November 2023

Back Matter Livestock and Animal Research Vol. 21 No. 3, November 2023

Back Matter Livestock and Animal Research Vol. 21 No. 3, November 2023

ENVIRONMENTAL SAFETY OF ATMOSPHERIC AIR IN THE ZONE OF INFLUENCE OF THERMAL POWER PLANTS WHILE USING SUNFLOWER WASTES

Air pollution is a significant and escalating global issue, posing a major threat to public health. Each year, it directly contributes to 6.5 million premature deaths, primarily due to cardiovascular and respiratory diseases resulting from exposure to air pollutants, notably fine particulate matter (PM). Beyond its well-documented health effects, recent evidence from epidemiological studies and controlled animal research underscore its detrimental impact on cognitive function and brain health. It's worth noting that residing in heavily polluted areas is linked to increased cognitive impairment and a heightened risk of neurodegenerative conditions. This association is particularly strong with pollutants stemming from energy and transportation, such as PM and nitrogen oxides (NOx). The intricate nature of PM pollutants, particularly ultrafine particles (UFP) with a diameter of less than 100 nm, enables them to infiltrate the human body, bypassing various protective mechanisms. Given this context, investigations into the influence of solid-fuel power plants, recognized by the European Environment Agency as major contributors to atmospheric air pollution, are of utmost importance. Existing regulatory and methodological frameworks do not adequately address contemporary realities and requirements, especially concerning the assessment and control of the environmental impact of thermal power plants using agricultural waste as fuel. This study aims to provide scientific and theoretical support for additional aspects related to the emissions of thermal power plants and their effects on both humans and the environment. This research holds particular significance when evaluating the placement of such facilities near populated areas and when making informed decisions regarding energy production technologies from renewable sources.

A Systematic Review of Butterfly Pea Flowers (Clitoria ternatea L.) in Reducing Body Weight and Improving Lipid Profile in Rodents with Obesity

Background: Butterfly pea flowers (Clitoria ternatea L.) are edible plants found in Asian countries that have several phytochemical compounds thathave potential anti-obesity and anti-dyslipidemia. From several in vivo studies, the administration of various extracts of butterfly pea flowers has different effects to reduce body weight (BW) or body mass index (BMI), and lipid profiles. Objectives: To analyze systematically the effects of butterfly pea flowers on BW or BMI and lipid profiles in rodents with or without obesity. Methods: This study used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and bias risk using the Systematic Review Centre for Laboratory Animal Experimentation (SyRCLEs).Original articles were from Google Scholar, PubMed, ResearchGate, and Science-Direct with criteria: randomized control trial (RCT), published from 2019 to 2023, rodents, and research outcomes (BW and lipid profiles). Results: Four original articles met the research criteria. Giving 1,000 mg/kg BW of the aqueous extract of butterfly pea flower for seven days reduced BW. Another study reported that giving 130 mg/kg BW butterfly pea flowers kombucha inhibited weight gain. Doses of 0.25 and 0.50% of the aqueous extracts of butterfly pea flowers for 15 weeks did not affect BW butthe dose of 2% prevented weight gain. Conclusions: Butterfly pea flowers have beneficial effects on reducing BW and improving lipid profiles in rodents with severaldiets although vary in animal models, diet types, extraction methods, and research design. This study becomes important evidence for further study.

Unraveling the Genetic Basis of Feed Efficiency in Cattle through Integrated DNA Methylation and CattleGTEx Analysis.

Feed costs can amount to 75 percent of the total overhead cost of raising cows for milk production. Meanwhile, the livestock industry is considered a significant contributor to global climate change due to the production of greenhouse gas emissions, such as methane. Indeed, the genetic basis of feed efficiency (FE) is of great interest to the animal research community. Here, we explore the epigenetic basis of FE to provide base knowledge for the development of genomic tools to improve FE in cattle. The methylation level of 37,554 CpG sites was quantified using a mammalian methylation array (HorvathMammalMethylChip40) for 48 Holstein cows with extreme residual feed intake (RFI). We identified 421 CpG sites related to 287 genes that were associated with RFI, several of which were previously associated with feeding or digestion issues. Activator of transcription and developmental regulation (AUTS2) is associated with digestive disorders in humans, while glycerol-3-phosphate dehydrogenase 2 (GPD2) encodes a protein on the inner mitochondrial membrane, which can regulate glucose utilization and fatty acid and triglyceride synthesis. The extensive expression and co-expression of these genes across diverse tissues indicate the complex regulation of FE in cattle. Our study provides insight into the epigenetic basis of RFI and gene targets to improve FE in dairy cattle.

Reduction of claudin-5 and aquaporin-4 in the rat hippocampal CA-1 and CA-3 regions of a learned helplessness model of depression

BackgroundAlthough findings from both animal and clinical research indicate that the blood-brain barrier (BBB) contributes to the pathogenesis of various psychiatric disorders (including depression), the underlying mechanisms are unknown. We investigated the levels of the tight-junction proteins claudin-5 and aquaporin-4 (AQP-4) in astrocytes of learned helplessness (LH) rats (an animal model of depression) and non-LH rats (a model of resilience). MethodsWe administered inescapable mild electric shock to rats and then identified the LH and non-LH rats by a post-shock test. The expressions of claudin-5 and AQP-4 in several brain regions of the LH and non-LH rats were then evaluated by a western blot analysis. ResultsThe levels of both claudin-5 and AQP-4 in the CA-1 and CA-3 hippocampal areas of the LH group were significantly lower than those of the control group, whereas those of the non-LH rats were not significantly different from those of the control and LH rats. ConclusionsThese results suggest that LH rats but not non-LH rats experienced down-regulations of claudin-5 and AQP-4 in the CA-1 and CA-3. It is possible that a region-specific modulation of claudin-5 and AQP-4 is involved in the mechanisms of vulnerability but not resilience in depression.

Anaesthesia-related cognitive dysfunction following cardiothoracic surgery in late middle-age and younger adults: A scoping review.

The incidence of postoperative cognitive dysfunction (POCD) is notably high after cardiac surgery, ranging from 25% to 30%, and is associated with a lower quality of life, increased patient dependency, and heightened mortality. Anaesthesia during cardiothoracic surgery significantly contributes to the risk of POCD in older adults by adversely affecting the brain, including reductions in blood flow and oxygen levels. This review aimed to evaluate factors associated with anaesthesia-related postoperative cognitive dysfunction (POCD) among adults younger than 65 years who underwent cardiothoracic surgeries. A systematic keyword search, following the scoping review framework, was performed in the PubMed and CINAHL databases. Original English-language studies that included adults younger than 65 years and addressed cognitive function after surgery along with anaesthesia management were included. Retrospective studies, animal research and in vitro and in vivo studies were excluded. Twenty-three articles were included (65.2% interventional studies). All studies lacked theoretical or conceptual frameworks. Ketamine's neuroprotective potential is questionable, and intravenous lidocaine may be considered a possible early agent for preventing POCD, but long-term effectiveness is uncertain. Compared to inhalational anaesthesia, total intravenous anaesthesia (TIVA) may be related to a decreased incidence of POCD. Variation in POCD assessment impacted the lack of homogeneity in obtained data. Moreover, the shorter-term timing of POCD evaluation such as in early days after surgery could be greatly influenced by medication and delirium. Although strategies such as TIVA, the use of neuroprotective anaesthetics and comprehensive preoperative assessments are suggested to prevent POCD, this multifactorial phenomenon cannot be explicitly attributed solely to anaesthetics or anaesthesia-related techniques. Use of standardized, reliable and valid tools for POCD assessment is encouraged for cross-study comparison. Nurses and certified nurse anaesthetists must be aware of risk factors for postoperative delirium and POCD so they can assess patients before and after surgery. Patients and caregivers need to be educated about cognitive changes after surgery and advised to report them to their health care provider if they occur.

Biosafety Risk Control Strategies in Laboratory Animal Research

To understand biosafety's current situation in laboratory animal research and risk factors affecting occupational health. Compliance surveys were conducted by questionnaire via Questionnaire Star (an application app on the Internet) in Chinese. Thirty-nine anonymous questionnaires were collected. The surveyed institution has established 24 types of ABSL (Animal Biosafety Laboratory) and biosafety management organizations and systems equipped with safety equipment. Our study also suggests that the principal of the laboratory establishment fails to perform supervision and inspection responsibilities, the inappropriate design of the animal biosafety laboratory, non-standardized personnel training and health management, non-strict waste management, and insufficient emergency management. The administrative department and work units should address certain safety and occupational health risks in laboratory animal research. The author proposes control strategies based on organizational guarantee, personnel management, emergency management, etc., to help prevent risks and ensure occupational health. Due to regional limitations and small sample size, the results may not be generalisable to all parts of the world. However, some of the key common issues may also be present in other regions, so we believe that this research still has some relevance.

High-Spatiotemporal-Resolution Ultrasound Flow Imaging to Determine Cerebrovascular Hemodynamics in Alzheimer's Disease Mice Model.

Although the relationships of cerebrovascular hemodynamic dysfunction with neurodegenerative diseases remain unclear, many studies have indicated that poor cerebral perfusion accelerates the progression of neurodegenerative diseases, such as Alzheimer's disease (AD). Small animal models are widely used in AD research. However, providing an imaging modality with a high spatiotemporal resolution and sufficiently large field of view to assess cerebrovascular hemodynamics in vivo remains a challenge. The present study proposes a novel technique for high-spatiotemporal-resolution vector micro-Doppler imaging (HVμDI) based on contrast-free ultrafast high frequency ultrasound imaging to visualize the cerebrovascular hemodynamics of the mouse, with a data acquisition time of 0.4 s, a minimal detectable vessel size of 38µm, and a temporal resolution of 500Hz. In vivo experiments are conducted on wild-type and AD mice. Cerebrovascular hemodynamics are quantified using the cerebral vascular density, diameter, velocity, tortuosity, cortical flow pulsatility, and instant flow direction variations. Results reveal that AD significantly change the cerebrovascular hemodynamics. HVμDI offers new opportunities for in vivo analysis of cerebrovascular hemodynamics in neurodegenerative pathologies in preclinical animal research.

The 3Rs Alone Will Not Reduce Total Animal Experimentation Numbers: A Fundamental Misunderstanding in Need of Correction

Abstract Government authorities often view the 3Rs of “replace, reduce, refine” popularized by Russell and Burch as both a regulatory principle and a governance principle aimed at reducing the total amount of animal distress in science. They thus expect that the 3Rs should, in time, result in changes in total animal experimentation numbers. Communications by Swiss authorities provide stark examples of this expectation. But the 3Rs do not aim at affecting animal experimentation at the level of total numbers; rather, they focus on study design in the individual case. While the underlying philosophy of the 3Rs indeed included a principle of seeking feasible overall reforms, this notion is completely absent in the 3Rs framework itself. Authorities need to stop treating the 3Rs as a means to reduce total distress and should instead invest resources into developing feasible and effective strategies for transformative governance in animal research.