Age-Related Brain Atrophy and the Positive Effects of Behavioral Enrichment in Middle-Aged Beagles.

Aging dogs serve as a valuable preclinical model for Alzheimer's disease (AD) due to their natural age-related development of ß-amyloid (Aß) plaques, human-like metabolism, and large brains that are ideal for studying structural brain aging trajectories from serial neuroimaging. Here we examined the effects of chronic treatment with the calcineurin inhibitor (CNI) tacrolimus or the nuclear factor of activated T cells (NFAT)-inhibiting compound Q134R on age-related canine brain atrophy from a longitudinal study in middle-aged beagles (36 females, 7 males) undergoing behavioral enrichment. Annual MRI was analyzed using modern, automated techniques for region-of-interest-based and voxel-based volumetric assessments. We found that the frontal lobe showed accelerated atrophy with age, while the caudate nucleus remained relatively stable. Remarkably, the hippocampus increased in volume in all dogs. None of these changes were influenced by tacrolimus or Q134R treatment. Our results suggest that behavioral enrichment can prevent atrophy and increase the volume of the hippocampus but does not prevent aging-associated prefrontal cortex atrophy.

Bayesian Phylogenetic Analysis on Multi-Core Compute Architectures: Implementation and Evaluation of BEAGLE in RevBayes With MPI.

Phylogenies are central to many research areas in biology and commonly estimated using likelihood-based methods. Unfortunately, any likelihood-based method, including Bayesian inference, can be restrictively slow for large datasets-with many taxa and/or many sites in the sequence alignment-or complex substitutions models. The primary limiting factor when using large datasets and/or complex models in probabilistic phylogenetic analyses is the likelihood calculation, which dominates the total computation time. To address this bottleneck, we incorporated the high-performance phylogenetic library BEAGLE into RevBayes, which enables multi-threading on multi-core CPUs and GPUs, as well as hardware specific vectorized instructions for faster likelihood calculations. Our new implementation of RevBayes+BEAGLE retains the flexibility and dynamic nature that users expect from vanilla RevBayes. In addition, we implemented native parallelization within RevBayes without an external library using the message passing interface (MPI); RevBayes+MPI. We evaluated our new implementation of RevBayes+BEAGLE using multi-threading on CPUs and 2 different powerful GPUs (NVidia Titan V and NVIDIA A100) against our native implementation of RevBayes+MPI. We found good improvements in speedup when multiple cores were used, with up to 20-fold speedup when using multiple CPU cores and over 90-fold speedup when using multiple GPU cores. The improvement depended on the data type used, DNA or amino acids, and the size of the alignment, but less on the size of the tree. We additionally investigated the cost of rescaling partial likelihoods to avoid numerical underflow and showed that unnecessarily frequent and inefficient rescaling can increase runtimes up to 4-fold. Finally, we presented and compared a new approach to store partial likelihoods on branches instead of nodes that can speed up computations up to 1.7 times but comes at twice the memory requirements.

Dog leukocyte antigen genotyping across class I and class II genes in beagle dogs as laboratory animals.

Dog leukocyte antigen (DLA) polymorphisms have been found to be associated with inter-individual variations in the risk, susceptibility, and severity of immune-related phenomena. While DLA class II genes have been extensively studied, less research has been performed on the polymorphisms of DLA class I genes, especially in beagle dogs commonly used as laboratory animals for safety evaluations in drug development. We genotyped four DLA class I genes and four DLA class II genes by locus-specific Sanger sequencing using 93 laboratory beagle dogs derived from two different strains: TOYO and Marshall. The results showed that, for DLA class I genes, 11, 4, 1, and 2 alleles, including a novel allele, were detected in DLA-88, DLA-12/88L, DLA-64, and DLA-79, while, for DLA class II genes, 1, 10, 6, and 7 alleles were detected in DLA-DRA, DLA-DRB1, DLA-DQA1, and DLA-DQB1, respectively. It was estimated that there were 14 DLA haplotypes, six of which had a frequency of ≥ 5%. Furthermore, when comparing the DLA diversity between TOYO and Marshall strains, the most common alleles and haplotypes differed between them. This is the first study to genotype all DLA loci and determine DLA haplotypes including all DLA class I and class II genes in dogs. Integrating information on the DLA diversity of laboratory beagle dogs should reinforce their benefit as an animal model for understanding various diseases associated with a specific DLA type.

Inflammatory Reprogramming Mediates Changes in Three-Dimensional Strain Capacity and Cardiac Function in Beagle Dogs with Doxorubicin-Related Cardiomyopathy.

Background: The cardiotoxicity of doxorubicin (DOX) limits its use in cancer treatment. To address this limitation, we developed a novel animal model that uses beagle dogs to investigate DOX-induced cardiac disorders. Unfortunately, the lack of effective cardioprotection strategies against DOX-induced cardiotoxicity poses a significant challenge. To establish a canine model for low-mortality DOX-induced cardiac dysfunction and explore the relationship between inflammatory reprogramming and DOX-related cardiotoxicity. Methods: Twenty male beagle dogs aged two years were randomly assigned into the DOX (N = 10) and control (CON) (N = 10) groups. DOX was infused (1.5 mg/kg) every two weeks until doses cumulatively reached 12 mg/kg. Serum biomarkers and myocardial pathology were evaluated, while real-time fluorescence-based quantitative polymerase chain reaction (RTFQ-PCR), two- and three-dimensional echocardiography (2DE and RT3DE), functional enrichment, and matrix correlation were also performed. Results: In the DOX group, high-sensitive cardiac troponin T (hs cTnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) were significantly increased. Myocardial pathology indicated early to medium myocardial degeneration via a decreased cardiomyocyte cross-sectional area (CSA). Increased levels of inflammatory gene transcripts (interleukin 6 (IL6), tumor necrosis factor (TNF), transforming growth factor ß (TGF ß ), intercellular adhesion molecule 1 (ICAM1), interleukin 1 (IL1), interleukin 1 ß (IL1 ß ), and interleukin 8 (IL8)), of collagen metabolism and deposition regulatory genes (matrix metalloproteinase (MMP) family and tissue inhibitor of matrix metalloproteinase (TIMP) family), and the natriuretic peptide family (NPS) (natriuretic peptide A, B and C (NPPA, NPPB, and NPPC)) were observed. Strain abnormalities in the right ventricular longitudinal septal strain (RVLSS), right ventricular longitudinal free-wall strain (RVLFS), left ventricular global longitudinal strain (LVGLS), and left ventricular global circumferential strain (LVGCS) were detected at week 28 (vs. week 0 or CON group, p < 0.05, respectively). A significant decline in RVLSS and RVLFS occurred at week 16, which was earlier than in the corresponding left ventricular areas. A significant right ventricular ejection fraction (RVEF) decline was noted at week 16 (vs. week 0, 33.92 ± 3.59% vs. 38.58 ± 3.58%, p < 0.05), which was 12 weeks earlier than for the left ventricular ejection fraction (LVEF), which occurred at week 28 (vs. week 0, 49.02 ± 2.07% vs. 54.26 ± 4.38%, p < 0.01). The right ventricular strain and functional damages correlated stronger with inflammatory reprogramming (most R from 0.60 to 0.90) than the left ones (most R from 0.30 to 0.65), thereby indicating a more pronounced correlation. Conclusions: Inflammatory reprogramming mediated disorders of strain capacity and cardiac function predominantly in the right side of the heart in the newly established DOX-related cardiomyopathy beagle dog model.

Characterization of an Uncommon Finding in the Basal Nuclei in Beagle Dogs: A Novel Potential Background Lesion in the Canine Brain.

Degenerative lesions specific to the basal nuclei have not been described as a background finding in Beagle dogs. This report comprises a documentation of seven cases. In the context of a nonclinical safety studies, the authors suggest documenting the lesion descriptively as degeneration neuropil, basal nuclei, bilateral as it is characterized by (1) vacuolation, neuropil; (2) gliosis (astro- and/or microgliosis); and (3) demyelination. This novel lesion is considered a potential new background change for several reasons: (1) It occurred in animals from test item-treated and also vehicle-treated groups; (2) no dose dependency was observed; (3) in one of six affected test item-treated dogs, the given compound was shown not to penetrate the blood-brain barrier; and (4) statistical comparison between the proportions of affected dogs in the treatment and control groups did not yield a statistically significant difference. The etiology remains unknown and is subject to further investigations.

The stereoselective pharmacokinetics of the desmethyl-phencynonate hydrochloride in beagle dogs.

The aim of this study was to investigate the chiral inversion and the stereoselective pharmacokinetic profiles of desmethyl-phencynonate hydrochloride after administration of the single isomer and its racemate to beagle dogs. A liquid chromatography with tandem mass spectrometry (LC-MS/MS) method was established for determination of the stereoisomers on chiral columns in beagle dog plasma, which met all the requirements. The chiral inversion in dogs of the desmethyl-phencynonate hydrochloride were studied after administration of the single isomer or the racemic modification. The stereoselective pharmacokinetic profiles of the desmethyl-phencynonate hydrochloride were studied by assays for simultaneous isomers after administration of the racemic modification. The results showed that the absorption of the R-configuration dosed as the single isomer was higher than it dosed as the racemic modification. The AUC(0-t), AUC(0-∞), and Cmax of the S-configuration were much higher than those of R-configuration after oral administration of the racemic desmethyl-phencynonate hydrochloride. The chiral inversion of desmethyl-phencynonate isomers could not occur in dogs after administration of the R-configuration.

Assessment of remdesivir and its nucleoside metabolite in beagle dogs and healthy humans by liquid chromatography coupled with triple quadrupole mass spectrometry.

The aim of this study was to assess the pharmacokinetics of the existing remdesivir intravenous formulation (100 mg dose) against the newly developed oral formulation (20 mg dose) for remdesivir and its active nucleoside metabolite (GS-441524) in beagle dogs followed by healthy human volunteers. A quantification method for remdesivir and its active nucleoside metabolite (GS-441524) in beagle dog and human plasma has been developed and validated using liquid chromatography coupled to triple quadrupole mass spectrometry detection. The analytical methods for beagle dogs and human differ in the calibration curve range, plasma matrix, processing volume, reconstitution volume and injection volume; however all other parameters were same in both methods. A simple protein precipitation extraction was carried out using acetonitrile containing the internal standard remdesivir D5. Remdesivir and GS-441524 were separated on an Endurus C-18P, 100 × 4.6 mm, 3 µm column and detected using a mass spectrometer with electrospray ionization in positive ion mode. The ion transitions used were m/z 603.1 → m/z 200.0 for remdesivir, m/z 292.0 → m/z 202.2 for GS-441524 and m/z 608.2 → m/z 205.1 for remdesivir D5. The calibration curve results were linear in beagle dog plasma (2.0-2,000.8 ng/ml range for remdesivir and 2.0-1,500.4 ng/ml for GS-441524) and human plasma (30.0-4,503.9 ng/ml range for remdesivir and 2.0-200.4 ng/ml for GS-441524). The recovery was >90% in beagle dog and human plasma. These methods were successfully used to determine the pharmacokinetic parameters of the intravenous injection and subcutaneous tablets dosage forms in beagle dogs and healthy humans.

13-Week Repeated Oral Toxicity and Toxicokinetic Studies of Rabeprazole Sodium and Sodium Bicarbonate Combination in Dogs.

The subchronic toxicity and toxicokinetics of a combination of rabeprazole sodium and sodium bicarbonate were investigated in dogs by daily oral administration for 13 consecutive weeks with a 4-week recovery period. The dose groups consisted of control (vehicles), (5 + 200), (10 + 400), and (20 + 800) mg/kg of rabeprazole sodium + sodium bicarbonate, 20 mg/kg of rabeprazole sodium only, and 800 mg/kg of sodium bicarbonate only. Esophageal ulceration accompanied by inflammation was observed in only one animal in the male (20 + 800) mg/kg rabeprazole sodium + sodium bicarbonate group. However, the severity of the ulceration was moderate, and the site of occurrence was focally extensive; thus, it was assumed to be a treatment-related effect of rabeprazole sodium + sodium bicarbonate. In the toxicokinetics component of this study, systemic exposure to rabeprazole sodium (AUClast and Cmax at Day 91) was greater in males than females, suggesting sex differences. AUClast and Cmax at Day 91 were increased compared to those on Day 1 in a dose-dependent manner. A delayed Tmax and no drug accumulation were observed after repeated dosage. In conclusion, we suggest under the conditions of this study that the no-observed-adverse-effect level (NOAEL) of the combination of rabeprazole sodium + sodium bicarbonate in male and female dogs is (10 + 400) and (20 + 800) mg/kg, respectively.

Invasion on So Grand a Scale: Darwin, Lyell, and Invasive Species.

The importance of naturalization-the establishment of species introduced into foreign places-to the early development of Darwin's theory of evolution deserves historical attention. Introduced and invasive European species presented Darwin with interpretive challenges during his service as naturalist on the HMS Beagle. Species naturalization and invasive species strained the geologist Charles Lyell's creationist view of the organic world, a view which Darwin adopted during the voyage of the Beagle but came to question afterward. I suggest that these phenomena primed Darwin to question the "stability of species." I then examine the role of introduced and invasive species in Darwin's early theorizing and negotiation with Lyell's ideas, recorded in his post-voyage "transmutation notebooks." Therein, the subject was an inflection point in his contention with Lyell's views and moreover, his theorizing on invasive species occasioned some of his earliest inklings of natural selection. Finally, I examine how naturalization was crucial to Lyell's own eventual conversion to evolutionism. I conclude with brief reflections on the implications of this narrative for our understanding of Darwin's reasoning, his intellectual relationship to Lyell, and the historical context that shaped his theory.

[Determination of nine components of fried Ziziphi Spinosae Semen extract in beagle dog plasma by UPLC-MS/MS and its application in pharmacokinetic research].

This study established a convenient, rapid, and sensitive ultra-performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS) method for simultaneous determination of magnoflorine,(R)-coclaurine, vicenin Ⅱ, isospinosin, spinosin, swertisin, N-nornuciferine, 6-feruloylspinosin, and jujuboside B in beagle dog plasma after oral administration of fried Ziziphi Spinosae Semen(FZSS) extract. The Waters HSS-T3 C_(18) column(2.1 mm×100 mm, 1.8 µm) was used. The methanol-aqueous solution(containing 0.01% formic acid) was adopted as the mobile phase for gradient elution. The nine components and two internal standards were completely separated within 8 min. The mass spectrometry detection was performed in multiple reaction monitoring(MRM) mode by positive and negative ion switching of electrospray ionization. The analytical method was validated in terms of specificity, selectivity, linear range, accuracy, precision, recovery, matrix effect, and stability. It could meet the requirement of pharmacokinetic research after oral administration of FZSS extract to beagle dogs. The results showed that the time to reach the peak concentration(T_(max)) of magnoflorine,(R)-coclaurine, vicenin Ⅱ, isospinosin, spinosin, 6-feruloylspinosin, and jujuboside B was 2.40-3.20 h, and the elimination halflife(t_(1/2)) was 2.08-6.79 h after a single-dose oral administration of FZSS to beagle dogs. The exposure of magnoflorine and spinosin was high, with a peak concentration(C_(max)) of 76.7 and 31.5 ng·mL~(-1) and an area under the curve(AUC_(0-∞)) of 581 and 315 ng·h·mL~(-1), respectively. The exposure of the remaining five compounds was lower, with a C_(max) of 0.81-13.0 ng·mL~(-1) and an AUC_(0-∞) of 6.00-106 ng·h·mL~(-1). This study provides a reference for the follow-up research of FZSS.

Usefulness of the Beagle Model in the Evaluation of Paracetamol and Ibuprofen Exposure after Oral Administration to Pediatric Populations: An Exploratory Study.

The present study aimed to explore the usefulness of beagle dogs in combination with physiologically based pharmacokinetic (PBPK) modeling in the evaluation of drug exposure after oral administration to pediatric populations at an early stage of pharmaceutical product development. An exploratory, single-dose, crossover bioavailability study in six beagles was performed. A paracetamol suspension and an ibuprofen suspension were coadministered in the fasted-state conditions, under reference-meal fed-state conditions, and under infant-formula fed-state conditions. PBPK models developed with GastroPlus v9.7 were used to inform the extrapolation of beagle data to human infants and children. Beagle-based simulation outcomes were compared with published human-adult-based simulations. For paracetamol, fasted-state conditions and reference-meal fed-state conditions in beagles appeared to provide adequate information for the applied scaling approach. Fasted-state and/or reference-meal fed-state conditions in beagles appeared suitable to simulate the performance of ibuprofen suspension in pediatric populations. Contrary to human-adult-based translations, extrapolations based on beagle data collected under infant-formula fed-state conditions appeared less useful for informing simulations of plasma levels in pediatric populations. Beagle data collected under fasted and/or reference-meal fed-state conditions appeared to be useful in the investigation of pediatric product performance of the two investigated highly permeable and highly soluble drugs in the upper small intestine. The suitability of the beagle as a preclinical model to understand pediatric drug product performance under different dosing conditions deserves further evaluation with a broader spectrum of drugs and drug products and comparisons with pediatric in vivo data.

Evolutionary trade-offs in osmotic and ionic regulation and expression of gill ion transporter genes in high latitude, cold clime Neotropical crabs from the 'end of the world'.

Osmoregulatory findings on crabs from high Neotropical latitudes are entirely lacking. Seeking to identify the consequences of evolution at low temperature, we examined hyperosmotic/hypo-osmotic and ionic regulation and gill ion transporter gene expression in two sub-Antarctic Eubrachyura from the Beagle Channel, Tierra del Fuego. Despite sharing the same osmotic niche, Acanthocyclus albatrossis tolerates a wider salinity range (2-65‰ S) than Halicarcinus planatus (5-60‰ S); their respective lower and upper critical salinities are 4‰ and 12‰ S, and 63‰ and 50‰ S. Acanthocyclus albatrossis is a weak hyperosmotic regulator, while H. planatus hyperosmoconforms; isosmotic points are 1380 and ∼1340 mOsm kg-1 H2O, respectively. Both crabs hyper/hypo-regulate [Cl-] well with iso-chloride points at 452 and 316 mmol l-1 Cl-, respectively. [Na+] is hyper-regulated at all salinities. mRNA expression of gill Na+/K+-ATPase is salinity sensitive in A. albatrossis, increasing ∼1.9-fold at 5‰ compared with 30‰ S, decreasing at 40-60‰ S. Expression in H. planatus is very low salinity sensitive, increasing ∼4.7-fold over 30‰ S, but decreasing at 50‰ S. V-ATPase expression decreases in A. albatrossis at low and high salinities as in H. planatus. Na+/K+/2Cl- symporter expression in A. albatrossis increases 2.6-fold at 5‰ S, but decreases at 60‰ S versus 30‰ S. Chloride uptake may be mediated by increased Na+/K+/2Cl- expression but Cl- secretion is independent of symporter expression. These unrelated eubrachyurans exhibit similar systemic osmoregulatory characteristics and are better adapted to dilute media; however, the expression of genes underlying ion uptake and secretion shows marked interspecific divergence. Cold clime crabs may limit osmoregulatory energy expenditure by hyper/hypo-regulating hemolymph [Cl-] alone, apportioning resources for other energy-demanding processes.

Early-Onset Asymptomatic Polypoid Cystitis in Two Adolescent Male Beagle Dogs.

This brief communication describes a rare spontaneous background lesion in the lower urinary tract of two male laboratory beagles. Proliferative lesions comprising a constellation of histological features consistent with polypoid cystitis were observed in the bladder of two adolescent dogs from a routine preclinical toxicology study. Both animals were clinically asymptomatic and had only minor alterations in urinalysis parameters. While chronic polypoid cystitis is well-recognized in adult pet dogs, this is the first reported case in purpose-bred laboratory beagles. An awareness of this uncommon background finding is important for toxicological pathologists to distinguish it from potential test article-related findings.

Multi-ethnic Imputation System (MI-System): A genotype imputation server for high-dimensional data.

OBJECTIVE: Genotype imputation is a commonly used technique that infers un-typed variants into a study's genotype data, allowing better identification of causal variants in disease studies. However, due to overrepresentation of Caucasian studies, there's a lack of understanding of genetic basis of health-outcomes in other ethnic populations. Therefore, facilitating imputation of missing key-predictor-variants that can potentially improve a risk health-outcome prediction model, specifically for Asian ancestry, is of utmost relevance. METHODS: We aimed to construct an imputation and analysis web-platform, that primarily facilitates, but is not limited to genotype imputation on East-Asians. The goal is to provide a collaborative imputation platform for researchers in the public domain towards rapidly and efficiently conducting accurate genotype imputation. RESULTS: We present an online genotype imputation platform, Multi-ethnic Imputation System (MI-System) (https://misystem.cgm.ntu.edu.tw/), that offers users 3 established pipelines, SHAPEIT2-IMPUTE2, SHAPEIT4-IMPUTE5, and Beagle5.1 for conducting imputation analyses. In addition to 1000 Genomes and Hapmap3, a new customized Taiwan Biobank (TWB) reference panel, specifically created for Taiwanese-Chinese ancestry is provided. MI-System further offers functions to create customized reference panels to be used for imputation, conduct quality control, split whole genome data into chromosomes, and convert genome builds. CONCLUSION: Users can upload their genotype data and perform imputation with minimum effort and resources. The utility functions further can be utilized to preprocess user uploaded data with easy clicks. MI-System potentially contributes to Asian-population genetics research, while eliminating the requirement for high performing computational resources and bioinformatics expertise. It will enable an increased pace of research and provide a knowledge-base for genetic carriers of complex diseases, therefore greatly enhancing patient-driven research. STATEMENT OF SIGNIFICANCE: Multi-ethnic Imputation System (MI-System), primarily facilitates, but is not limited to, imputation on East-Asians, through 3 established prephasing-imputation pipelines, SHAPEIT2-IMPUTE2, SHAPEIT4-IMPUTE5, and Beagle5.1, where users can upload their genotype data and perform imputation and other utility functions with minimum effort and resources. A new customized Taiwan Biobank (TWB) reference panel, specifically created for Taiwanese-Chinese ancestry is provided. Utility functions include (a) create customized reference panels, (b) conduct quality control, (c) split whole genome data into chromosomes, and (d) convert genome builds. Users can also combine 2 reference panels using the system and use combined panels as reference to conduct imputation using MI-System.

Effect and mechanical mechanism of spontaneous breathing on oxygenation and lung injury in mild or moderate animal ARDS.

OBJECTIVE: The present study aimed to determine the effect and mechanical mechanism of spontaneous breathing during mechanical ventilation on oxygenation and lung injury using Beagles dogs mild or moderate acute respiratory distress syndrome (ARDS) model. METHODS: After inducing mild or moderate ARDS by infusion of oleic acid, Eighteen Beagles dogs were randomly split into Spontaneous breathing group (BIPAPSB, n = 6), and Complete muscle paralysis group (BIPAPPC, n = 6),Six Beagles without ventilator support comprised the control group. Both groups were ventilated for 8 h under BIPAP mode. High-pressure was titrated TV to 6 ml/kg. A multi-pair esophageal balloon electrode catheter was used to measure respiratory mechanics and electromyogram. End-expiratory lung volume (EELV), gas exchange and respiratory variables were recorded in the process of mechanical ventilation. The contents of Interleukin (IL)-6 and IL-8 in lung tissue were measure using qRT-PCR. Besides, lung injury score was calculated in the end of mechanical ventilation. RESULTS: Based on the comparable setting of ventilator, BIPAPSB group exhibited higher safety peak transpulmonary pressure, abdominal pressure, EELV and P/F(PaO2/FiO2) than BIPAPPC group, whereas mean transpulmonary pressure, the mRNA levels of the IL-6 and IL-8 in the lung tissues and lung injury score in BIPAPSB group were lower than those in BIPAPPC group. CONCLUSION: In mild to moderate ARDS animal models, during mechanical ventilation, SB may improve respiratory function and reduce ventilator-induced lung injury. The mechanism may be that spontaneous inspiration up-regulates peak transpulmonary pressure and EELV; Spontaneous expiration decreases mean transpulmonary pressure by up-regulating intra-abdominal pressure, thereby reducing stress and strain.

28-day repeated dose toxicity and toxicokinetics study on new melatonergic antidepressant GW117 in beagle dogs.

GW117 is new melatonergic antidepressant being developed to show better antidepressant action than agomelatine. The purpose of this study was to evaluate the toxicity and to determine potential target organs after oral (gavage) administration of the test article GW117 for 28 days and to assess the reversibility after a 4-week recovery phase in beagle dogs. Toxicokinetics was also evaluated. Four groups were designed in this study, including the vehicle control group and the GW117 50, 150 and 500 mg/kg/day groups, with 5 dogs/sex/group. Body weight, hematology, clinical chemistry, gross necropsy, organ weight, histopathology, and other indicators were examined. Results showed that animals dosed at ≥150 mg/kg/day showed gastrointestinal reactions (watery feces and dark green/red brown feces), with a dose-response relationship in the incidence and severity grade. Female dogs at 500 mg/kg/day had an increase in organ weight and ratios of the liver at the end of the dosing phase. Histopathology examination showed that some animals at 500 mg/kg/day, especially female animals, had minimal centrilobular hepatocyte hypertrophy in the liver, which reversed after 28-day recovery. With the exception of the above, no GW117-related abnormality was noted. Meanwhile, there were no sexual differences in drug exposure and accumulation after the first and last dosing. The no observed adverse effect dose level (NOAEL) was 150 mg/kg/day, under which mean Cmax and AUC0 → t were 583.5 and 2767.0 ng/ml*h for females and 663.2 and 4046.3 ng/ml*h for males on Day 28.

A rapid and sensitive UPLC-MS/MS method for the determination of zanubrutinib in beagle plasma and its application in pharmacokinetics.

A reliable and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of zanubrutinib in the plasma of beagle dogs. The column used was an Acquity BEH C18 column (2.1 mm × 50 mm, 1.7 µm), maintained at 40°C with an injection volume of 2 µl. The gradient elution program was as follows: 0-1 min, 10-10% A; 1-1.1 min, 10-90% A; 1.1-2.1 min, 90-90% A; 2.1-2.2 min, 90-10% A; 2.2-3.0 min, 10-10% A. Mobile phase A was 0.1% formic acid, B was acetonitrile, and the total analysis time was 3 min. The mass spectrometry was performed in positive ion mode, and the scanning mode was multi-reaction monitoring mode with electrospray ionization as the ion source; m/z 472.2 → 455.01 for zanubrutinib and m/z 441.03 → 137.99 for ibrutinib (internal standard). The plasma samples were processed by protein precipitation. The standard curve showed good linearity (r2 = 0.999 8) in the range of 1.0-1,000 ng/ml (zanubrutinib) with a low limit of quantification of 1 ng/ml. Also, the intra-day and inter-day precision (RSD) was <5.88% and the accuracy (RE) ranged from -1.56 to 1.08%; the recoveries of zanubrutinib in beagle plasma ranged from 90.12 to 93.53% (RSD 1.67-6.42%) and the ME values of zanubrutinib were 98.70-101.06% (RSD 5.37-8.49%, n = 6). All values meet US Food and Drug Administration requirements. A rapid, highly selective and sensitive method for the determination of zanubrutinib concentration in plasma by UPLC-MS/MS was successfully developed. This method is suitable for pharmacokinetic studies in beagle dogs by following oral administration of zanubrutinib.

Development of na HPLC-MS/MS method for the determination of ginsenosides Rg1 and Rb1 from 'Shenmai' Injection in beagle dogs after single and multiple doses and application in pharmacokinetics.

Shenmai Injection (SMI), which tonifies Qi and prevents exhaustion, nourishes Yin and generates body fluid, is usually used in the treatment of shock with deficiency of Qi and Yin, coronary artery disease, viral myocarditis, granulocytopenia and chronic pulmonary heart disease clinically. Ginsenosides Rg1 and Rb1 are the main active ingredients of SMI. In this study, high-performance liquid chromatography tandem mass spectrometry methods for quantification of Rb1 and Rg1 in beagle dogs were developed and validated according to international regulatory guidelines. The methods were applied to measure the pharmacokinetics parameters of the two ginsenoside after intravenous administration. The linear ranges of the analytes were 3.9-1,000 ng/ml for Rg1 and Rb1. After injection of single and multiple doses of SMI (1 ml/kg), the plasma concentration-time profiles of Rg1 and Rb1 met the characteristics of one-compartment and typical two-compartment intravenous injection.

Effects of SKCPT on Osteoarthritis in Beagle Meniscectomy and Cranial Cruciate Ligament Transection Models.

Osteoarthritis (OA) affects >500 million people globally, and this number is expected to increase. OA management primarily focuses on symptom alleviation, using non-steroidal anti-inflammatory drugs, including Celecoxib. However, such medication has serious side effects, emphasizing the need for disease-specific treatment. The meniscectomy and cranial cruciate ligament transection (CCLx)-treated beagle dog was used to investigate the efficacy of a modified-release formulation of SKI306X (SKCPT) from Clematis mandshurica, Prunella vulgaris, and Trichosanthes kirilowii in managing arthritis. SKCPT's anti-inflammatory and analgesic properties have been assessed via stifle circumference, gait, incapacitance, histopathology, and ELISA tests. The different SKCPT concentrations and formulations also affected the outcome. SKCPT improved the gait, histopathological, and ELISA OA assessment parameters compared to the control group. Pro-inflammatory cytokines and matrix metalloproteinases were significantly lower in the SKCPT-treated groups than in the control group. This study found that SKCPT reduces arthritic lesions and improves abnormal gait. The 300 mg modified-release formulation was more efficacious than others, suggesting a promising approach for managing OA symptoms and addressing disease pathogenesis. A high active ingredient level and a release pattern make this formulation effective for twice-daily arthritis treatment.

Differential miRNA expression profiles in the bone marrow of Beagle dogs at different stages of Toxocara canis infection.

BACKGROUND: Toxocara canis is distributed worldwide, posing a serious threat to both human and dog health; however, the pathogenesis of T. canis infection in dogs remains unclear. In this study, the changes in microRNA (miRNA) expression profiles in the bone marrow of Beagle dogs were investigated by RNA-seq and bioinformatics analysis. RESULTS: Thirty-nine differentially expressed (DE) miRNAs (DEmiRNAs) were identified in this study. Among these, four DEmiRNAs were identified at 24 h post-infection (hpi) and all were up-regulated; eight DEmiRNAs were identified with two up-regulated miRNAs and six down-regulated miRNAs at 96 hpi; 27 DEmiRNAs were identified with 13 up-regulated miRNAs and 14 down-regulated miRNAs at 36 days post-infection (dpi). Among these DEmiRNAs, cfa-miR-193b participates in the immune response by regulating the target gene cd22 at 24 hpi. The novel_328 could participate in the inflammatory and immune responses through regulating the target genes tgfb1 and tespa1, enhancing the immune response of the host and inhibiting the infection of T. canis at 96 hpi. In addition, cfa-miR-331 and novel_129 were associated with immune response and self-protection mechanisms at 36 dpi. 20 pathways were significantly enriched by KEGG pathway analysis, most of which were related to inflammatory response, immune response and cell differentiation, such as Cell adhesion molecules (CAMs), ECM-receptor interaction and Focal adhesion. CONCLUSIONS: These findings suggested that miRNAs of Beagle dog bone marrow play important roles in the pathogenesis of T. canis infection in dogs and provided useful resources to better understand the interaction between T. canis and the hosts.