Laboratory Animals Research Articles

A Retrospective Report of Carprofen Administration as Post-Operative Analgesia Reveals Negative Effects of Recommended Doses

Effective pain management in laboratory animals is crucial for both animal welfare and the reliability of scientific research. We retrospectively examined the effects of carprofen as post-operative analgesia in Sprague Dawley rats following stereotactic surgery. Our data indicate that administering carprofen twice daily (5 mg/kg), as currently recommended by Die Gesellschaft für Versuchstierkunde/Society for Laboratory Animal Science (GV-SOLAS), led to adverse effects such as reduced food and water intake, disrupted fecal excretion, and abdominal bloating consistent with peritonitis. Continued administration exacerbated these symptoms, with post-mortem findings of intestinal obstructions and ulcers. However, when the frequency was reduced to once daily, such adverse symptoms were not observed. These results are based on incidental data collected from various neuroscientific experiments, resulting in small and uneven sample groups across various experimental cohorts. The inherent imbalances in these groups present challenges for statistical interpretation. While the findings suggest that less frequent carprofen use may reduce adverse effects, the surgical interventions and concurrent use of other drugs in these experiments likely exacerbated these outcomes. Further investigation into the interactions between carprofen, surgical stress, and other perioperative factors is needed to refine analgesia protocols in laboratory animals. Despite these limitations, these observations contribute to understanding analgesia protocols and may assist in improving animal welfare practices.

Novel Endoplasmic Reticulum-Targeted Luminescent Probe for Visualization of Carbon Monoxide in Drug-Induced Liver Injury.

Drug-induced liver injury (DILI) is a major hepatic dysfunction commonly caused by hepatotoxic drug overdose, resulting in a considerable number of fatalities worldwide. Recent studies have highlighted the regulatory and hepatoprotective effects of carbon monoxide (CO) during the liver injury process. However, precisely tracking the dynamic changes in the composition of CO in DILI is still a great challenge. In this work, leveraging the innovative "quencher-insertion" strategy, a unique endoplasmic reticulum (ER)-targetable lanthanide complex-based luminescence probe, ER-ANBTTA-Eu3+/Tb3+, has been developed for the selective and accurate monitoring of CO fluxes in live cells and laboratory animals. The new probe is composed of three covalently linked functional moieties: the terpyridine polyacid-Eu3+/Tb3+-mixed chelates as the long-lived luminophore, a p-toluenesulfonamide moiety as the ER-anchoring motif, and an allyloxy-nitrobenzyl ether moiety as the CO-specific recognition unit. Upon reaction with CO in the presence of Pd2+ ions, the Tsuji-Trost reaction leads to the cleavage of the allyloxy-nitrobenzyl group from the Eu3+/Tb3+-mixed chelates, which results in the restoration of Tb3+ emission at 538 nm and the attenuation of Eu3+ emission at 688 nm, leading to a dramatic increase of the I538/I688 ratio. In addition to the exceptional response sensitivity and selectivity toward CO, ER-ANBTTA-Eu3+/Tb3+ also exhibits the outstanding ER-locating capability, which allows the probe to be used for imaging of CO in the ER of live cells. Using this probe, combined with the time-gated luminescence imaging mode, the exogenous and endogenous CO in ER of live cells were monitored without the interference of background autofluorescence. Moreover, the upregulation of hepatic CO in DILI mice was successfully visualized. The results suggested the potential of ER-ANBTTA-Eu3+/Tb3+ for deeply exploring the functions of CO in DILI pathogenesis.

T. Muris Infection Dynamics of a Fresh, Wild Isolate: Is the Established E Isolate Still Relevant?

For decades, parasitic worms such as Trichuris muris have been maintained in laboratory animals, providing insights into host-parasite interactions and host immune responses. The most used T. muris isolate is the E isolate, established in the laboratory in 1954. However, one concern with these model systems is the potential for laboratory-induced selection and therefore changes in host-parasite interactions. To address these concerns, we compare the E isolate with a recently isolated T. muris isolate (M isolate), established from wild house mice (Mus musculus domesticus, Isle of May, UK), in their capacity to infect laboratory mice. High dose infection of C57BL/6 mice revealed that significantly more parasites of the M isolate survived to the adult stage compared to the E isolate. Worm persistence was associated with heightened TNF-α and IL-10 secretion upon parasite-specific re-stimulation, and higher serum IgG1 and IgG2c levels, concomitant with an increase in T-bet+ and ICOS+ CD4+ T effector-memory cells. Differences in host response to the isolates were not as pronounced during low dose infection. Our study highlights the need for regular evaluation of lab-maintained parasite isolates against freshly isolated parasites to understand whether the established lab strains remain relevant model systems for our understanding of parasitic infections.

Valifenalate-induced non-adverse thyroid changes via adaptive induction of uridine 5′-diphospho-glucuronosyltransferase (UGT) in the liver of dogs and rats but not humans

Some rat and dog toxicology studies with the fungicide valifenalate showed minimal, non-adverse thyroid changes, mostly above the maximum tolerated dose, and concomitantly with liver effects. This publication describes their mode of action (MOA), combining in vivo and new approach methodologies (NAMs), in a weight of evidence approach.Data demonstrate a MOA of liver enzyme induction via nuclear receptor CAR/PXR activation, increased thyroxine (T4) metabolism and elevated thyroid stimulating hormone (TSH) level, leading to thyroid follicular cell hypertrophy and increased thyroid weight. Non-human relevance of the MOA was demonstrated in in vitro cross species assays in rat, dog and human hepatocytes. Increased gene expression and activity of cytochrome P450s (CYPs) and uridine 5′-diphospho-glucuronosyltransferases (UGTs) were observed in rat and dog hepatocytes exposed to valifenalate, with increased T4 clearance and/or T4 glucuronidation/T4-UGT activity. Therefore, a causal relationship between increased liver enzyme induction and thyroid effects in dogs and rats is concluded. Rat hepatocytes were most sensitive, while valifenalate did not increase T4-UGT activity above 2-fold of vehicle control or T4 glucuronidation and T4 clearance in human hepatocytes. Consequently, valifenalate exposure in humans is unlikely to lead to decreased T4 levels, and subsequent thyroid and developmental neurotoxicity effects. Alternative human-relevant thyroid MOAs were excluded, i.e. inhibition of deiodinases (DIO), thyroperoxidase (TPO) or the sodium iodide symporter (NIS).Due to known species differences in thyroid homeostasis between humans and laboratory animals and, importantly, based on the presented data, this liver enzyme mediated MOA is considered not relevant for human hazard assessment.

Does an Osteoporosis-like Condition Jeopardize the Osseointegration Process around Dental Implants Placed in Animal Models? A Systematic Review.

Knowing that osteoporosis is a metabolic disease that could decrease dental implant success and survival, the purpose of this review was to gather information on the characteristics of implant osseointegration in animal models of induced osteoporosis. By pointing out the role of some factors that could improve the success rate in these situations, this study aimed to enhance the knowledge about this process that can be further translated to clinical designs. A systematic search in PubMed/Medline, Lilacs, Cochrane Library, Scopus and Web of Science was conducted to identify information between 2002 and 2023 regarding osseointegration of dental implants in animal models of induced osteoporosis. The following search strategy was utilized and adjusted to each database: (((dental implant) AND (Osseointegration)) AND (osteoporosis)) AND/OR (osteoporosis treatment). The inclusion criteria were animal studies in English, involving the placement of an osseointegrated implant in osteoporotic bone, and evaluating bone to implant contact (BIC) %. Exclusion criteria were studies in humans, in vitro studies, procedures involving any kind of bone graft and studies evaluating medication related osteonecrosis of the jaw. A standardized data extraction form was used to record data for each study, covering article title, date, authors, number of animals, purpose of study, type of analysis used by authors, follow-up, type of implant, test and control groups, intervention and conclusions. The risk of bias of the included studies was assessed using the Systematic Review Centre for Laboratory animal Experimentation (SYRCLE) Risk of Bias tool.20 Results: A total of 204 articles were found for evaluation and selection. All of the 43 selected studies evaluated the bone-implant contact (BIC) %. Other parameters such as bone to implant mechanical interface, bone area (BA) and bone volume (BV) ratio were also evaluated in some of the studies. There was a tendency for compromised results of implant osseointegration in the presence of osteoporosis. Modification of the implant surface, systemic and local use of anti-resorptive drugs and other substances, showed benefits for the implant success in osteoporotic sites. Still, no consensus among studies on the superiority of systemic medications in improving the process of peri-implant bone repair, was observed. Although it is possible to improve the osseointegration of implants in osteoporotic bone, either by using systemic or local factors, the metabolic bone syndrome caused by osteoporosis can jeopardize the osseointegration of dental implants.

Potential hepatoprotective properties of synthetic derivatives of thiourea — 2-aminobenzothiazole and IEM-2320

BACKGROUND: Toxic hepatitis is characterized by a significant severity of the course and by high mortality. So, search for effective means of correcting this condition seems to be relevant. It has previously been shown that some thiazolo[5,4-b]indole derivatives are capable to prevent experimental toxic liver damage in laboratory animals. In continuation of this direction, the study of the hepatoprotective properties of synthetic derivatives of thiourea 2-aminobenzothiazole and IEM-2320 was undertaken. AIM: To study the potential hepatoprotective properties of 2-aminobenzothiazole and IEM-2320 in acute carbon tetrachloride poisoning. MATERIALS AND METHODS: Experiments were carried out on 30 male white outbred rats (150–270 g). On a model of carbon tetrachloride poisoning (50% solution of CCl4 in vaseline oil, 0.2 ml/100 g of body weight), the potential hepatoprotective properties of 2-aminobenzothiazole (32 mg/kg) and IEM-2320 (20 mg/kg) were investigated. Ademethionine (Heptral, AbbVie, S.r.L, Italy) at a dose of 20 mg/kg was used as a comparison drug. The studied drugs were administered intraperitoneally 4 times: one hour before the introduction of CCl4, and then — for three subsequent days after the poisoning with CCl4. The results were compared with those of 2 control groups. Animals of the 1st control group were not exposed to CCl4, instead of the studied drugs, they were injected with an equivalent volume of saline solution (0.2 ml/100 g of body weight). Animals of the 2nd control group did not receive any treatment after the CCl4 poisoning. Blood was taken on the seventh day of the experiment. The total contents of protein, glucose, and total cholesterol in blood serum were determined, and the activities of alanine aminotransferase and aspartate aminotransferase were evaluated. RESULTS: Under the CCl4 poisoning, the administration of 2-aminobenzothiazole led to a significant decrease in the concentrations of glucose, total protein, total cholesterol and alanine aminotransferase activity. When IEM-2320 was administered under the condition of poisoning, a decrease in the concentrations of total protein, glucose, urea, total cholesterol, and the alanine aminotransferase activity was observed. CONCLUSIONS: A significant decrease in the biochemical parameters of blood serum after administration of 2-aminobenzothiazole and IEM-2320 under the condition of CCl4 poisoning demonstrates thir potential hepatoprotective properties under acute hepatotropic poisonings.

Automated home cage monitoring of an aging colony of mice—Implications for welfare monitoring and experimentation

IntroductionOur understanding of laboratory animal behavior and the implications of husbandry activities on their wellbeing remains incomplete. This is especially relevant with an aging colony as their activity patterns may change as they mature. Home Cage Monitoring (HCM) provides valuable insights into mouse activity within the animal's own environment and can shed light on acclimatization periods and responses to husbandry activities such as cage changing. The aim of this study was to monitor and explore changes in the activity and rest disturbance (RDI) patterns of an aging colony of male and female C57/BL6 mice.MethodsThe mice were housed in the Digitally Ventilated Cage® system, for up to 18 months of age. Data was then downloaded to investigate how the activity patterns and RDI of the mice changed over time. Habituation, aging and cage change assessments were conducted using linear mixed models, while cage separation and stereotypic behavior investigations were conducted by visual inspection of the data.ResultsAs expected during the study, mice were less active during the light phase compared to the dark phase. However, on arrival mice displayed heightened activity and RDI during the light phase and reduced activity and RDI during the dark phase, taking several days to adjust to baseline “acclimatized” patterns. With age, overall activity significantly decreased from 5 months until 14 months of age, after which it increased back toward baseline levels. We also observed activity spikes during our monitoring of this colony. Prolonged housing can lead to alarming stereotypic behaviors in animals. Cages of mice flagged for potential stereotypy displayed sustained activity spikes in the light and dark phases. Spikes in activity during the dark phase were much more pronounced than in the light phase. Cage changing led to an increase in the light phase activity and RDI compared to the previous day, with no observed difference in the dark phase post-cage change. This effect remained consistent as the animals aged.DiscussionThis study explores changes in the activity patterns of an aging colony of male and female C57/BL6 mice housed in the Digitally Ventilated Cage® system. We identified distinct aging phases concerning activity and RDI differences and a potential new welfare application for the DVC®, specifically for early detection of stereotypy. In conclusion, the adoption of HCM systems should be considered for long-term animal housing from both a welfare and behavioral perspective.

Saturated Fats: Time to Assess Their Beneficial Role in a Healthful Diet

Saturated fats are widely seen as undesirable components of a healthy diet, as a result of their illusory association with elevated serum cholesterol. The regulation of serum cholesterol is now better understood and a lack of polyunsaturated fatty acids, rather than an abundance of saturated fatty acids, is responsible. Palmitic acid was shown to incite inflammation at unnaturally high concentrations in tissue culture, but later was found to play an auxiliary role as a precursor to ceramide biosynthesis and possibly in the palmitoylation of membrane receptors involved in the initiation of inflammation. Studies of arthritic inflammation in lab animals showed that dietary saturated fats are anti-inflammatory, whereas polyunsaturated oils are pro-inflammatory. Inflammation plays a role in numerous metabolic diseases, including insulin resistance, fatty liver disease and metabolic syndrome, among others. Fat, as triglycerides in adipose tissue, is an efficient way for living organisms to store energy and reduce the toxicity of other macronutrients. Macronutrients, such as excess carbohydrates and polyunsaturated fatty acids, are converted to saturated and monounsaturated fatty acids for storage as triglycerides in adipose tissue. Fatty acids are released from adipose tissue during fasting and as a result of some metabolic disorders, where elevated levels of nonesterified fatty acids in blood can lead to hepatic lipid accumulation, inflammation and insulin resistance. Although most serum nonesterified fatty acids may be saturated fatty acids, they are not necessarily derived from the diet. This paper will attempt to clarify the role of saturated fatty acids, and palmitic acid in particular, with regard to certain adverse health conditions.

Efficacy and safety of HERG channel agonists for treatment of Long QT Syndrome type 8

Abstract Background Substrate-based approach aimed at repolarization abbreviaton using mexiletine was shown to normalize the QTc interval and reduce the event rate in LQT3, and is now considered standard-of-care. Unfortunately, mexiletine is partially efficacious in other malignant forms of LQTS, such as LQT2 and LQT8. Novel compounds, such as HERG channel agonists, potentially capable of safely and efficaciously abbreviating the repolarization have not been tested in a clinically relevant model. Purpose To investigate the efficacy and safety of repolarization shortening using ICA-105574, the most potent compound belonging to the class of HERG channel agonists, in a clinically relevant, first-in-class porcine model of LQT8. Methods We used a combination of 12-lead ECG and electroanatomical mapping (EAM) to obtain data on the QTc interval, local activation time (LAT), local repolarization time (LRT) and its gradients, and reentrant vulnerability index (RVI), at baseline and after drug administration. We used LQT8 pigs of both genders weighing between 60 kg and 80 kg. All procedures were conducted following local regulations for the care and use of laboratory animals after authorization by relevant authorities. We used mixed effects linear regression model to assess the effect of ICA-105574 on the QTc interval and paired nested t-test to assess the effect of ICA-105574 on EAM-derived parameters. Results As a first step, we assessed the effects of ICA-105574 on the QTc interval. Compared to baseline, a single dose of 3 mg/kg of ICA-105574 resulted in an immediate and pronounced shortening of the QTc interval in all animals (∆QTc at 5 minutes post-injection: -28%, p<0.001). We then investigated repeated intravenous administrations of 3 mg/kg doses at 10-minute intervals for a total of 4 doses (i.e., overall drug dose of 12 mg/kg). Importantly, we did not observe excessive QTc shortening (∆QTc 6 mg/kg: -26%; ∆QTc 9 mg/kg: -26%; ∆QTc 12 mg/kg: -30%, p<0.001 for all) nor did we observe any proarrhythmic events in any of the animals studied. In a second phase of the study, we used EAM to assess the modifications in the arrhythmic substrate induced by ICA-105574. Importantly, ICA-105574 not only shortened the duration of ventricular repolarization (∆LRT: -21%, p=0.017), but also reduced the dispersion of ventricular repolarization (∆Max. LRT gradient: -69%, p=0.020). This, coupled with reduction of the activation delay as compared to baseline (∆LAT: -28%, p=0.072), had a net positive effect on the arrhythmic substrate, as evidenced by an amelioration by 30% of global RVI (∆RVIG,D: -32%, p=0.029). Conclusions In our LQT8 pig model, ICA-105574, a potent HERG channel agonist, safely and efficaciously ameliorated the arrhythmic substrate. These results suggest that HERG channel agonists, as a novel class of antiarrhythmics, could have clinical application as a novel substrate-based therapy for LQT8.Figure 1

Inhibition of ketohexokinase prevents fructose-induced insulin resistance and endothelial dysfunction in high fat and sucrose-fed mice via enhancing energy expenditure

Abstract Introduction Cardiovascular disease linked to fatty liver poses a significant threat to health. Consumption of high-fat diets (HFD) is known to trigger a cascade of health issues including obesity, diabetes and non-alcoholic fatty liver disease (NAFLD). These conditions are exacerbated, with the addition of dietary sugar to high-fat diets (HFSD), resulting in non-alcoholic steatohepatitis (NASH). Studies have shown that fructokinase (ketohexokinase or KHK) knockdown protects mice from HFSD-induced NASH. Purpose This study focused on examining the temporal changes of metabolic perturbations, triggered by sugar consumption, particularly in the transition from fatty liver to cardiovascular disease. Methods C57/BL6 wild type (WT) and KHK-knockout mice were fed with HFD or HFSD for different durations between 6 to 20 weeks, to induce NAFLD and NASH. Western blotting and quantitative-PCR were carried out on tissues and isolated endothelial cells for protein and mRNA expressions, respectively. Glucose and insulin tolerance tests and whole-body energy measurements were performed at different time-points. Combined Laboratory Animal Monitoring System was used to monitor various parameters of energy expenditure. Functional interactions between endothelial cells and adipose tissues were carried out using an in-house Organ-On-a-chip technology. Endothelial function was studied by measuring isometric tensions in organ bath. Results KHK-deficient mice had significantly lower weight compared to WT littermates. Wild-type mice fed HFD and HFSD exhibited significant glucose intolerance, insulin resistance, and endothelial dysfunction compared to KHK-knockout mice. However, HFSD led to more severe outcomes compared to HFD, demonstrating differing temporal effects on glucose intolerance and insulin resistance. Interestingly, KHK-knockout mice were significantly protected from the effects induced by HFSD, as well as, such as increased body weight, fasting hyperglycemia, hyperinsulinemia and endothelial function. KHK-knockout mice exhibited significant increase in oxygen consumption and energy expenditure, both in HFD and HFSD-fed conditions. These data suggest that high energy-expenditure is one of the primary mechanisms, in reducing adiposity and body weight in HFSD-fed knockout mice. Notably, KHK-deficient mice were protected against sugar-induced fat accumulation, random hyperinsulinemia and significant impairment of endothelial function. Conclusions A novel finding in this study is that KHK ablation protects not only against HFSD-induced, but also HFD-induced pathologies via significantly enhancing energy expenditure. The results suggest that targeting KHK could potentially mitigate the development of fatty liver and cardiovascular diseases, induced by high calorie diets.

Increased endothelial cell uptake of erythrocyte-derived extracellular vesicles carrying arginase-1 induces endothelial dysfunction in type 2 diabetes

Abstract Background Recently, we have demonstrated that red blood cells (RBCs) from individuals with type 2 diabetes (T2D-RBCs) induce endothelial dysfunction. However, the mechanism by which RBCs communicate with the vessel is unknown. Extracellular vesicles (EVs) are actively secreted by practically all cell types, including RBCs, and represent a novel mechanism of intercellular communication. However, the involvement of EVs from RBC in the development of endothelial dysfunction remains to be elucidated. Purpose This study was designed to test the hypothesis that EVs are key players in the communication and the transfer of signalling between RBCs and the vascular endothelium to induce endothelial dysfunction in T2D. Methods RBCs from T2D patients and age-matched healthy controls (H-RBCs) were incubated for 18h with Krebs-Henseleit buffer (20% haematocrit) for EV release. RBC-derived EVs in the conditioned medium were isolated using a membrane affinity column. The EVs were co-incubated with mouse aortae to evaluate endothelium-dependent relaxation and with endothelial cells for expression analysis. The uptake of the EVs by endothelial cells and their content of arginase-1 were determined. The functional involvement of arginase was investigated using pharmacological interventions and expression analyses. All animal experiments were performed according to the principles of laboratory animal care (NIH Publication no. 85-23 revised 1985) and human procedures according to the declaration of Helsinki with approval by the Swedish Ethical Review Authority. Results The uptake of EVs derived from T2D-RBCs by endothelial cells was 2-fold greater than that of EVs from H-RBCs (Fig. 1A-B). Inhibiting the uptake of EVs derived from T2D-RBCs by the addition of heparin during the co-incubation rescued the endothelial function (Fig. 1C). Arginase-1 was detected in RBC-derived EVs (Fig. 2A). Arginase-1 mRNA and protein levels were increased in endothelial cells following co-incubation with EVs derived from T2D-RBCs (Fig. 2B-D). Additionally, the increase in arginase-1 protein induced by EVs derived from T2D-RBCs in endothelial cells was observed also following mRNA silencing for arginase-1 (Fig. 2E-F). Finally, mouse aortae co-incubated with EVs derived from T2D-RBCs in the presence or absence of the arginase inhibitor 2(S)-amino-6-boronohexanoic acid significantly attenuated the impairment in endothelial function induced by EVs derived from T2D-RBCs (Fig. 2G). Conclusion Increased uptake of RBC-derived EVs by the endothelial cells is an important feature of the endothelial dysfunction induced by these EVs in T2D. In addition, these EVs carry arginase-1 protein to induce endothelial dysfunction. The mechanism underlying the increased uptake of EVs in target cells is of importance to identify in future studies, as it could lead to new treatment strategies.

Assessment of coronary microvascular function with absolute coronary fl ow measurements

Abstract Background Reliable assessment of microvascular function is essential, both in research setting and clinical practice. New techniques, such as continuous coronary thermodilution, are very promising and could revolutionize the field. However, there is a need for proper validation before widespread use is possible. Purpose The goals of this study were: 1. to validate the potential of saline infusion to generate maximum hyperemia in vivo. 2. to validate absolute blood flow (ABF) measured with continuous coronary thermodilution at higher (40-50 ml/min) infusion speeds 3. To assess the safety of higher infusion speeds. Methods Fourteen closed-chest sheep underwent ABF measurements with increasing saline infusion speeds with and without adenosine. Another seven open-chest sheep underwent these measurements with epicardial doppler flow probes on both the left anterior descending artery and left circumflex coronary artery. Maximal hyperemia was defined as maximal flow after 45 seconds of proximal occlusion. The principles of laboratory animal care and all national regulations were followed. Results 20 ml/min of saline infusion induced lower hyperemic coronary flow (140 vs 191 ml/min, p=0.0165) and lower coronary flow reserve (CFR) (1.82 vs 3.21, p= <0.0001) than coronary occlusion. In contrast, 30 ml/min resulted in flow (196 vs 192 ml/min, p=0.8292) and CFR (2.77 vs 3.21, p=0.1107) that were not different from post-occlusion. There was a significant flow overestimation bias (Bland-Altman: Bias ± SD: -73.09 ± 30.52, 95% Limits of agreement: -132.9 to -13.27) with 40-50ml/min of saline. Occasionally, higher saline infusion rates resulted in ischemic ECG-changes and ventricular fibrillation (9.5% at 50 ml/min). Conclusions Continuous saline infusion of 30ml/min, but not 20 ml/min, induced maximal hyperemia. ABF measured with saline infusion speeds of 40-50 ml/min was not accurate nor safe, and should therefore be avoided.

Establishment of an evaluation method of a chemical-susceptibility for wildlife using counter-QSAR and machine learning

Certain environmental chemicals are harmful to lifeforms. Determining the extent to which they are damaging to animals is challenging as it is ethically reprehensible to expose animals to lethal doses of chemicals in the lab and, besides, not every species of animal can be housed in a laboratory. So, how can experiments involving animals in their natural habitat, and without causing harm, be conducted? A team of researchers at the Laboratory of Toxicology in the School of Veterinary Medicine at Kitasato University in Japan, which includes Junior Associate Professor Kazuki Takeda, is working to develop a way to determine the susceptibility of animal species to given environmental chemicals. Takeda is applying his background in environmental toxicology to the research. The focus for the team is on wild animals and using non-invasive methods. As there is such great interspecies variability in chemical sensitivity, it is difficult to extrapolate toxicity test results obtained from laboratory animals to wild animals. Therefore, the researchers are using genetic information and protein-chemical binding simulations to evaluate interspecies differences in chemical sensitivity. The goal is to develop a model that can predict chemical sensitivity differences between species using simulation methods and machine learning using DNA information obtained from hair.

A novel immunopharmacological biocompound

The publication is devoted to topical issues of experimental study of new biocompounds, based on the creation of a consortium of biological composite compounds – biological active substances (metabiotics) produced by strains 59T and 60T of saprophytic compounds of the genus Bacillus subtilis. These strains are very promising for the creation of hepatopicts, new medicinal substances, in the creation and development of a new pharmacological class of hepatoprotectors. Previous studies have shown the safety and hepatoprotective effect of biologically active drugs. It is worth noting that the very effective compounds are the produced biologically active substances – metabolites of bacterial origin, on the basis of which it seems appropriate to create a new class of drugs – metabiotics. The absence of vegetative probiotic cells in such compounds will reduce the additional immune load on the body. The combined use of these compounds provides a potentiated pharmacological effect. In this regard, it seemed appropriate, under the conditions of modeling toxic liver damage by carbon tetrachloride, to conduct an experimental assessment of the immunotropic effect of biologically active substances (BAS) on laboratory animals in order to confirm the effect on cellular factors of immunity. The purpose of the study was to study the effect of the combined use of dietary supplements produced by Bacillus subtilis microorganisms on indicators of cellular immunity in laboratory animals with toxic liver damage. Acute toxic hepatitis was reproduced in white laboratory rats with repeated intragastric administration of carbon tetrachloride. The comparison drug was a registered hepatoprotective drug – ursosan. The immunotropic effect was assessed using factors such as: phagocytic activity of macrophages and neutrophils (FA), NBT test, quantitative assessment of antibody-forming cells, T and B lymphocytes. As a result of the studies performed, reliable data were obtained on an increase in the number of T and B lymphocytes, antibody-forming cells, as well as an increase in FA, which confirms the activation of all parts of cellular immunity in conditions of acute toxic liver damage. The data obtained allow us to recommend the studied biocompound for the creation of new drug candidates of microbiological origin, hepatoprotective agents with immunotropic effects.

Biomarkers of genotoxic damage in pulmonary alveolar macrophages: a review.

DNA damage is one of the primary mechanisms underlying cancer and other chronic degenerative diseases. Early evaluation of this damage in the affected cells and tissues is crucial for understanding pathogenesis and implementing effective prevention strategies. However, isolating target cells from affected organs, such as the lungs, can be challenging. Therefore, an alternative approach is to evaluate genotoxic damage in surrogate cells. Pulmonary alveolar macrophages are ideally suited for this purpose because they are in close contact with the target cells of the bronchial and alveolar epithelium, share the exact mechanisms and levels of exposure, and are easily recoverable in large numbers. This review comprehensively lists all studies using alveolar macrophages as surrogate cells to show genotoxic lung damage in humans or laboratory animals. These investigations provide fundamental information on the mechanisms of DNA damage in the lung and allow for better assessment and management of risk following exposure to inhalable genotoxic agents. Furthermore, they may be a valuable tool in cancer chemoprevention, helping the right choice of agents for clinical trials.

Influence of Bacterial Nanocellulose Consumption on the Content of Macronutrients and Trace Elements in the Organs of Rats.

Bacterial nanocellulose (BNC) prepared by the methods of "green" bionanotechnological synthesis is considered a promising food additive and food ingredient. At the same time, the risk of reducing the bioavailability of minerals due to their adsorption on BNC fibers having a high specific surface area and high adsorption and ion exchange capacity cannot be excluded. We studied the effect of oral administration of BNC on the accumulation of macronutrients and trace elements included in the diet in the liver and kidneys of laboratory animals. Male Wistar rats received BNC at doses of 0 (control), 1, 10, and 100 mg/kg body weight as part of their diet for 8 weeks. The content of 30 macronutrients and trace elements in the liver and kidneys was determined by inductively coupled plasma mass spectrometry. It was found that BNC at all doses did not significantly change the content of the main essential macronutrients and trace elements in the organs (Ca, Cr, Cu, Fe, K, Mg, Mn, Na, P, Se, and Zn), which indicates the absence of a negative effect on their bioavailability. Among other elements, a statistically significant decrease in the content of As, B, Cd, Co, and Pb in the liver and an increase in Al, B, Ba, Ni, and Pb in the kidneys were revealed (more than 20% of the control). The revealed decrease in the bioaccumulation of cobalt can indicate inhibition of assimilation of certain chemical forms of this trace element under the action of BNC.

Integration of single-photon miniature fluorescence microscopy and electrophysiological recording methods for <i>in vivo</i> studying hippocampal neuronal activity

The miniature single-photon fluorescent microscope (miniscope) enables the visualization of calcium activity in vivo in freely moving laboratory animals, providing the capability to track cellular activity during the investigation of memory formation, learning, sleep, and social interactions. However, the use of calcium sensors for in vivo imaging is limited by their relatively slow (millisecond-scale) kinetics, which complicates the recording of high-frequency spike activity. The integration of methods from single-photon miniature fluorescent microscopy with electrophysiological recording, which possesses microsecond resolution, represents a potential solution to this issue. Such a combination of techniques allows for the simultaneous recording of optical and electrophysiological activity in a single animal in vivo. In this study, a flexible polyimide microelectrode was developed and integrated with the gradient lens of the miniscope. The in vivo tests conducted in this research confirmed that the microelectrode combined with the gradient lens facilitates simultaneous single-photon calcium imaging and local field potential recording in the hippocampus of an adult mouse.

Effects of radiofrequency electromagnetic radiation with a focus on haematology parameters

The use of radiofrequency electromagnetic radiation (RF-EMR) has steadily increased since the 1950s. RF-EMR is used in medicine, industry, household appliances, security and navigation, and especially in wireless elecommunications and animal husbandry. The widespread use of RF-EMR, especially with the introduction of 5G networks, raises concerns about potential adverse effects on human and animal health. The effects and mechanisms of RF-EMR impacts of 5G network frequencies on human and animal health are still unknown orpoorly understood. Current research findings include the biological effects of RF-EMR on genotoxicity, cell proliferation, gene expression, cell signalling, cell membrane function, and the function of immune, ematopoietic, and reproductive systems. Exposure of humans and laboratory animals to RF-EMR emitted from cell phones and many other electronic devices of 4G and older technologies has been shown to have detrimental effects on blood cells and to cause changes in the complete blood count. This depends on the type of organisms exposed, sources,frequency, electric field level and duration of exposure. There is sparse data in the available literature on the effects of RF-EMR on haematology indicators and erythrocyte morphometry in domestic animals. Therefore, the aim of this scientific review is to highlight the effects of RF-EMR on haematology indicators, erythrocyte morphometry, and platelet activation in humans and animals, taking into account the findings on the effects of 5G electromagnetic radiation on these indicators. Considering the ubiquitous electromagnetic pollution, it is important to gain knowledge about the effects of RF-EMR on human and animal health. In addition, it is necessary to determine the effects following in vitro exposure of blood to RF-EMR, especially due to the storage and use of blood and blood products in transfusion medicine.

Systemic effect of the oncological process on the dog’s body

The article presents the results of an analysis of a non-randomized study of the prevalence of paraneoplastic syndromes in primary spontaneous malignant neoplasms in dogs. The study was conducted in 2022–2024 on the basis of the Department of Diseases of Small Domestic, Laboratory and Exotic Animals and the Research Laboratory of Oncology, Ophthalmology and Animal Biochemistry of the Russian Biotechnological University “ROSBIOTECH”. The object of the study were 948 dogs with primary spontaneous malignant neoplasms confirmed by morphological methods.The aim of the work was to study the frequency of paraneoplastic syndromes in dogs with neoplasia.The diagnosis of paraneoplastic syndrome was made by excluding other possible etiological factors for the development of clinical and laboratory abnormalities identified during a comprehensive examination of dogs. As a result of the study, the incidence of paraneoplasia was 54.54% of cases. Hematological (44.41%) and gastrointestinal (37.13%) paraneoplastic syndromes were most often recorded, less often endocrine (3.27%) and ophthalmological (3.38%), extremely rarely renal (1.27%), osteoarticular (0.42%) and dermatological (0.42%). The main hematological manifestations of the systemic effect of the oncological process were: anemia (12.87%), neutrophilic leukocytosis (12.76%) and thrombocytopenia (8.86%). Gastrointestinal paraneoplastic syndrome in most cases was manifested by a decrease in body weight (33.65%) and hyporexia (18.04%), inflammatory and erosive ulcerative lesions of the gastrointestinal tract (7.59%). During the study, a case of a nonspecific systemic reaction to a malignant tumor in the form of fever in the absence of infectious and inflammatory processes (0.11%) was registered.

Spontaneous hepatocellular and gastric tumours in African clawed frogs (Xenopus laevis).

Three seven-year-old African clawed frogs (Xenopus laevis) from an animal research facility showed weight loss, coelomic distention and an abnormal swimming gait were euthanised on welfare grounds. A complete necropsy of each animal showed a focal, firm, dark brown to green mass with multifocal haemorrhages in the left liver lobe in two animals and a transmural, firm, beige, multilobulated gastric mass in another animal. Additionally, one of the frogs with the hepatic mass had haemocoeloma. Histologically, the hepatic masses were diagnosed as hepatocellular adenomas and the gastric mass as a gastric carcinoma with trans-coelomic metastases. The three tumours were immunophenotyped using the following antibodies: cytokeratin AE1/AE3, vimentin, E-cadherin, P53 and Ki67 and, additionally, for the hepatic tumours only, synaptophysin, Prox-1, S100 and Sox-9. Masson's trichrome, Periodic acid Schiff and Gram stains was also performed in selected cases. One of the hepatocellular adenomas was weakly positively labelled with E-cadherin whereas the other showed variable positivity for Sox-9 only. Vimentin labelled the stroma and sinusoidal endothelia. Interestingly in the liver, the cytokeratin AE1/AE3 labelling was restricted to the biliary epithelium and sinusoidal endothelia. The gastric carcinoma labelled positively with cytokeratin AE1/AE3 only. This report aims to guide laboratory animal veterinarians to accurately diagnose multi-organ masses in amphibians. To the authors' knowledge, this is the first comprehensive morphological study on a case series of hepatocellular and gastric neoplasia in X. laevis.