The biological characteristics and infection dynamics of a novel H3N2 canine influenza virus genotype in beagles.

BACKGROUND: The canine influenza virus (CIV) outbreak has garnered considerable attention as it poses a significant threat to dog health. During the H3N2 CIV evolution in beagles, the virus formed a new clade after 2019 and gradually became more adaptable to other mammals. Therefore, successfully elucidating the biological characteristics and constructing a canine influenza infection model is required for CIV characterization. METHODS: We performed genetic analyses to examine the biological characteristics and infection dynamics of CIV. RESULTS: The genotype of our H3N2 CIV strain (from 2019 in Shanghai) belonged to the 5.1 clade, which is now prevalent in China. Using MDCK cells, we investigated viral cytopathic effects. Virus size and morphology were observed using transmission electron microscopy. Beagles were also infected with 104, 105, and 106 50% egg-infectious doses (EID50). When compared with the other groups, the 106 EID50 group showed the most obvious clinical symptoms, the highest virus titers, and typical lung pathological changes. Our results suggested that the other two treatments caused mild clinical manifestations and pathological changes. Subsequently, CIV distribution in the 106 EID50 group was detected by hematoxylin and eosin (H&E) and immunofluorescence (IF) staining, which indicated that CIV primarily infected the lungs. CONCLUSIONS: The framework established in this study will guide further CIV prevention strategies.

A validated UPLC-MS/MS method for quantification of glutamine in plasma and pharmacokinetic study of oral glutamine tablets in healthy Beagles.

This study aimed to clarify the laws of glutamine tablets absorption, distribution, and metabolism in Beagles and to provide a basis for formulating dosing regimens. Twelve healthy Beagles were enrolled the absolute bioavailability study with a crossover design . Glutamine tablets (240 mg/kg b.w.) or glutamine sterile solution (60 mg/kg b.w.) were administered. A method for the determination of glutamine in Beagles' plasma by UPLC-MS/MS was established, with high sensitivity, specificity, and simplicity. Based on the study of endogenous glutamine concentration, the mean concentration of the four time points before drug administration was selected as the background concentration of glutamine. Pharmacokinetic parameters were calculated by non-compartment model. The Cmax of glutamine was 136.11 ± 72.51 µg/ml, Tmax was 0.85 ± 0.29 h, and t1/2λz was 0.42 ± 0.27 h after oral administration. The AUC0-t of glutamine was 116.30 ± 75.15 h·µg/ml vs. 44.55 ± 22.48 h·µg/ml following oral and IV administration, respectively, with an absolute bioavailability of 64.74% ± 19.18%. The results showed glutamine was quickly absorbed and eliminated in Beagles with high bioavailability. Therefore, glutamine is suitable to be prepared as oral tablets and recommended to shorten the dosing interval.

Influence of general anaesthesia on the intravenous acetaminophen pharmacokinetics in Beagle dogs.

OBJECTIVE: To determine if general anaesthesia influences the intravenous (IV) pharmacokinetics (PK) of acetaminophen in dogs. STUDY DESIGN: Prospective, crossover, randomized experimental study. ANIMALS: A group of nine healthy Beagle dogs. METHODS: Acetaminophen PK were determined in conscious and anaesthetized dogs on two separate occasions. Blood samples were collected before, and at 5, 10, 15, 30, 45, 60 and 90 minutes and 2, 3, 4, 6, 8, 12 and 24 hours after 20 mg kg-1 IV acetaminophen administration. Haematocrit, total proteins, albumin, alanine aminotransferase, aspartate aminotransferase, urea and creatinine were determined at baseline and 24 hours after acetaminophen. The anaesthetized group underwent general anaesthesia (90 minutes) for dental cleaning. After the administration of dexmedetomidine (3 µg kg-1) intramuscularly, anaesthesia was induced with propofol (2-3 mg kg-1) IV, followed by acetaminophen administration. Anaesthesia was maintained with isoflurane in 50% oxygen (Fe'Iso 1.3-1.5%). Dogs were mechanically ventilated. Plasma concentrations were analysed with high-performance liquid chromatography. PK analysis was undertaken using compartmental modelling. A Wilcoxon test was used to compare PK data between groups, and clinical laboratory values between groups, and before versus 24 hours after acetaminophen administration. Data are presented as median and range (p < 0.05). RESULTS: A two-compartmental model best described time-concentration profiles of acetaminophen. No significant differences were found for volume of distribution values 1.41 (0.94-3.65) and 1.72 (0.89-2.60) L kg-1, clearance values 1.52 (0.71-2.30) and 1.60 (0.91-1.78) L kg-1 hour-1 or terminal elimination half-life values 2.45 (1.45-8.71) and 3.57 (1.96-6.35) hours between conscious and anaesthetized dogs, respectively. Clinical laboratory variables were within normal range. No adverse effects were recorded. CONCLUSIONS AND CLINICAL RELEVANCE: IV acetaminophen PK in healthy Beagle dogs were unaffected by general anaesthesia under the study conditions. Further studies are necessary to evaluate the PK in different clinical contexts.

Effects of Regorafenib, a Multi-Kinase Inhibitor, on Conjunctival Scarring in a Canine Filtration Surgery Model in Comparison with Mitomycin-C.

Regorafenib eye drops were developed for treating age-related macular degeneration. This study aimed to investigate the effects of this multi-kinase inhibitor on intraocular pressure (IOP), bleb formation, and conjunctival changes in a canine filtration surgery model. Glaucoma filtration surgery models were created in 24 eyes of 24 beagles. In experiment 1 (Ex 1), regorafenib eye drops (regorafenib group: n = 6) or a vehicle (control group, n = 6) were instilled twice daily for 4 weeks postoperatively. In experiment 2 (Ex 2), regorafenib eye drops were instilled as in Ex 1 (regorafenib group: n = 6) for 12 weeks while conventional intraoperative mitomycin-C (MMC) was utilized (MMC group: n = 6), In Ex 1, only the regorafenib group showed significant IOP reduction with a significantly higher bleb score. Subconjunctival area, collagen density, vessels, and cells showing proliferation and differentiation were lower in subconjunctival tissue in the regorafenib group. In Ex 2, no significant difference was found in IOP reduction and bleb formation between the regorafenib and MMC groups; bleb walls were significantly thicker and collagen density and vessels were higher in the regorafenib group; and no differences were observed in the above-mentioned cells. Thus, regorafenib might be a better alternative to MMC for creating thicker and less ischemic blebs in glaucoma filtration surgery.

Comparative pharmacokinetics and a clinical laboratory evaluation of intravenous acetaminophen in Beagle and Galgo Español dogs.

OBJECTIVE: To assess the pharmacokinetics (PK) and conduct a clinical laboratory evaluation of acetaminophen in Beagle and Galgo Español (GE) dogs. STUDY DESIGN: Prospective randomized experimental trial. ANIMALS: A total of 20 healthy dogs - 10 Beagles and 10 GE (six males and four females in both groups). METHODS: Acetaminophen (10 and 20 mg kg-1) was administered intravenously (IV) to the dogs on two different occasions. Plasma concentrations were analysed by high-performance liquid chromatography. PK analysis was undertaken using compartmental modelling with ADAPT 5 software. Simulations after multiple IV doses were investigated. Clinical laboratory values such as red blood cell (RBC) count, haemoglobin (Hb), haematocrit (Ht), white blood cell (WBC) count, platelet count, total proteins, alanine aminotransferase (ALT), aspartate aminotransferase, urea and creatinine were measured before and 24 hours after acetaminophen administration in combination with clinical examination to assess side effects resulting from the drug. RESULTS: A two-compartmental model best described time-concentration profiles of acetaminophen. PK parameters were different as a result of a breed effect. For doses of 10 and 20 mg kg-1, respectively, clearance values were 1.70 (1.15-2.27) and 1.62 (1.06-2.86) L kg-1 hour-1 for Beagles and 1.18 (0.70-1.39) and 1.08 (0.67-1.35) L kg-1 hour-1 for GE; elimination half-life values were 2.64 (0.52-4.46) and 2.86 (0.87-4.63) hours for Beagles and 3.49 (1.89-7.80) and 4.57 (2.08-8.90) hours for GE. Significant differences were also found between GE and Beagles in the RBC count, Ht, Hb, WBC count and serum ALT before drug administration, and these differences were maintained 24 hours later, independent of the dosage used. For each breed, no side effects resulting from IV acetaminophen administration were observed at doses of either 10 or 20 mg kg-1. CONCLUSIONS AND CLINICAL RELEVANCE: IV PK of acetaminophen was different between Beagles and GE dogs. Side effects were not detected. Further studies are necessary to evaluate the PK in a clinical context.

Evaluation of three-dimensional superimposition technique on parietal bone of the puberty beagle dogs.

OBJECTIVES: This study aimed to (a) evaluate the stability of the parietal bone of 6-9 months old beagles and (b) examine whether parietal regional superimposition can provide an atraumatic and effective solution for further maxillary expansion study. MATERIALS AND METHODS: Six prepubertal 6-month-old male beagles were included. Six miniscrew markers were inserted into the left and right sides of the parietal bone, and two of them were placed bilaterally near the palatal suture. The subjects were scanned with cone beam computed tomography (CBCT) at three time points of T0 (6 months old), T1 (7.5 months old) and T2 (9 months old), respectively. All skull models were analyzed by both the miniscrew superimposition and the parietal regional superimposition. RESULTS: The two superimposition methods had no significant difference (p > 0.05) in displacements of miniscrew markers between left and right first premolars (PM1). The maxillary superimposition between T0 and T2 indicated that the length and width of the maxillary as well as the width of the zygoma root increased significantly (p < 0.05), while the height of maxillary had no significant difference (p > 0.05) over the 3 months. CONCLUSIONS: The parietal bone is relatively stable for beagles from 6 months old to 9 months old and thus can be used as a reference region for 3D skull model superimposition of the beagle dog.

The construction and application of a population physiologically based pharmacokinetic model for methadone in Beagles and Greyhounds.

Methadone is an opioid analgesic in veterinary and human medicine. To help develop appropriate pain management practices and to develop a quantitative model for predicting methadone dosimetry, a flow-limited multiroute physiologically based pharmacokinetic (PBPK) model for methadone in dogs constructed with Berkeley Madonna™ was developed. The model accounts for intravenous (IV), subcutaneous (SC), and oral administrations, and compartmentalizes the body into different components. This model was calibrated from plasma pharmacokinetic data after IV administration of methadone in Beagles and Greyhounds. The calibrated model was evaluated with independent data in both breeds of dogs. One advantage of this model is that most physiological parameter values for Greyhounds were taken directly from the original literature. The developed model simulates available pharmacokinetic data for plasma concentrations well for both breeds. After conducting regression analysis, all simulated datasets produced an R2  > 0.80 when compared to the measured plasma concentrations. Comparative analysis of the dosimetry of methadone between the breeds suggested that Greyhounds had ~50% lower 24-hr area under the curve (AUC) of plasma or brain concentrations than in Beagles. Furthermore, population analysis was conducted with this study. This model can be used to predict methadone concentrations in multiple dog breeds using breed-specific parameters.

Effects of Gelatin Hydrogel Containing Anti-Transforming Growth Factor-ß Antibody in a Canine Filtration Surgery Model.

In this present study, we investigated the effect of a controlled release of anti-transforming growth factor ß (TGF-ß) antibody on intraocular pressure (IOP), bleb formation, and conjunctival scarring in a canine glaucoma filtration surgery model using gelatin hydrogel (GH). Glaucoma surgery models were made in 14 eyes of 14 beagles and divided into the following two groups: (1) subconjunctival implantation of anti-TGF-ß antibody-loaded GH (GH-TGF-ß group, n = 7), and (2) subconjunctival implantation of GH alone (GH group, n = 7). IOP and bleb features were then assessed in each eye at 2- and 4-weeks postoperative, followed by histological evaluation. We found that IOP was significantly reduced at 4-weeks postoperative in the two groups (p < 0.05) and that IOP in the GH-TGF-ß-group eyes was significantly lower than that in the GH-group eyes (p = 0.006). In addition, the bleb score at 4-weeks postoperative was significantly higher in the GH-TGF-ß group than in the GH group (p < 0.05), and the densities of fibroblasts, proliferative-cell nuclear antigen (PCNA)-positive cells, mast cells, and TGF-ß-positive cells were significantly lower in the GH-TGF-ß group than in the GH group. The findings of this study suggest that, compared with the GH-group eyes, implantation of anti-TGF-ß antibody-loaded GH maintains IOP reduction and bleb formation by suppressing conjunctival scarring due to the proliferation of fibroblasts for a longer time period via a sustained release of anti-TGF-ß antibody from GH.

[Experimental study scavenging effect of paraquat by hemoperfusion].

Objective: To determine the scavenging effect and the change of metabolism of paraquat (PQ) using hemoperfusion (HP) once and twice within 12 hours after intoxication and explore the better scheme of HP. Methods: 18 beagles were randomly divided into 3 groups. Single HP group, Double HP group and Control group. Peripheral veins blood was collected at different times within 48 hours after exposure in each group. Toxin concentration was measured, analyzed and compared among 3 groups. Results: 6 hours after exposure, Single HP group and Double HP group has finished the first HP treatment, and the concentration of PQ was lower than that of the control group, the difference was statistically significant (P<0.05) . 10 hours after exposure, there was no statistical difference of toxin concentration among 3 groups (P>0.05) . 12 hours after exposure, Double HP group has finished the second HP treatment, the concentration of PQ was significantly lower than that of Single HP group and Control group (P<0.05) . 24 hours and 48 hours after exposure, there was no statistical difference of toxin concentration among 3 groups (P>0.05) . Statistical difference were not observed in toxicokinetical parameters among 3 groups (P>0.05) . Conclusion: HP treatment once and twice within 12 hours after intoxication could effectively reduce the toxin concentration in the peripheral veins blood after HP for about 4 hours, then the toxin concentration would return to the same level as Control group quickly. It was suggested that at the beginning of poisoning, HP treatment once or twice could not significantly change the metabolism of paraquat.

[Pharmacokinetics of Tongmai granule in acute myocardialischemic model beagles].

Tongmai granule (TM) is composed of Puerariae Lobatae Radix (Gegen), Salviae Miltiorrhizae Radix et Rhizoma(Danshen) and Chuanxiong Rhizoma(Chuanxiong). It has been used to treat ischemic cardio-cerebrovascular diseases for decades. For the purpose of elucidating its pharmacodynamic material foundation, the absorption and pharmacokinetic property of TM were investigated in acute myocardial ischemic model beagles. All serum samples were extracted before analysis with ethyl acetate after being acidified by hydrochloric acid. Under negative ESI detection mode, the chromatographic separation was carried out with monolithic C18 column for gradient elution. A simultaneous quantitative analysis was made on 15 polyphenols, including 8 from Gegen, 5 from Danshen and 2 from Chuanxiong, in 8.5 min. The validation result demonstrated the specificity, accuracy and precision of the method in line with the bioanalysis requirements. After TM solution was administrated to acute myocardial ischemic model beagles through duodenum injection, serum samples were collected after 6 h. The quantitative detection proved the prompt absorption of TM, all of the components were detectable in the blood samples 5 min later, and reached peak respectively at 0.18-3.83 h after administration. The components presented large variabilities. The most components were exposed in serum with puerarin and salvianic acid A, followed by 3'-methoxypuerarin, mirificin, and 3'-hydroxypuerarin. The study proves puerarin and salvianic acid A are dominating active components of TM in acute myocardial ischemic model beagles.

An HPLC method for the quantitation of 3-pentylbenzo[c]thiophen-1(3H)-one in dog plasma and its application to a pharmacokinetic study.

A simple, sensitive and reproducible high-performance liquid chromatography (HPLC) assay method was developed for the estimation of 3-pentylbenzo[c]thiophen-1(3H)-one (S5 ), a potential anti-ischemic stroke agent, in dog plasma. The analytical procedure involves protein precipitation of S5 and nobiletin (internal standard) from dog plasma with acetonitrile. Chromatographic separation was achieved on Sapphire C18 analytical column with methanol-water (80:20, v/v) as mobile phase. The eluate was monitored using a UV detector set at 260 nm. The calibration curves were linear over the range of 0.2-20 µg/mL. Absolute recoveries of S5 were 79.2-86.1% from dog plasma. The intra- and inter-day relative standard deviation precisions were <7 and 5%, respectively. The method was successfully applied to the pharmacokinetic study of S5 in beagle dogs.

Optimization of tracheoesophageal fistula model established with T-shaped magnet system based on magnetic compression technique.

BACKGROUND: The magnetic compression technique has been used to establish an animal model of tracheoesophageal fistula (TEF), but the commonly shaped magnets present limitations of poor homogeneity of TEF and poor model control. We designed a T-shaped magnet system to overcome these problems and verified its effectiveness via animal experiments. AIM: To investigate the effectiveness of a T-shaped magnet system for establishing a TEF model in beagle dogs. METHODS: Twelve beagles were randomly assigned to groups in which magnets of the T-shaped scheme (study group, n = 6) or normal magnets (control group, n = 6) were implanted into the trachea and esophagus separately under gastroscopy. Operation time, operation success rate, and accidental injury were recorded. After operation, the presence and timing of cough and the time of magnet shedding were observed. Dogs in the control group were euthanized after X-ray and gastroscopy to confirm establishment of TEFs after coughing, and gross specimens of TEFs were obtained. Dogs in the study group were euthanized after X-ray and gastroscopy 2 wk after surgery, and gross specimens were obtained. Fistula size was measured in all animals, and then harvested fistula specimens were examined by hematoxylin and eosin (HE) and Masson trichrome staining. RESULTS: The operation success rate was 100% for both groups. Operation time did not differ between the study group (5.25 min ± 1.29 min) and the control group (4.75 min ± 1.70 min; P = 0.331). No bleeding, perforation, or unplanned magnet attraction occurred in any animal during the operation. In the early postoperative period, all dogs ate freely and were generally in good condition. Dogs in the control group had severe cough after drinking water at 6-9 d after surgery. X-ray indicated that the magnets had entered the stomach, and gastroscopy showed TEF formation. Gross specimens of TEFs from the control group showed the formation of fistulas with a diameter of 4.94 mm ± 1.29 mm (range, 3.52-6.56 mm). HE and Masson trichrome staining showed scar tissue formation and hierarchical structural disorder at the fistulas. Dogs in the study group did not exhibit obvious coughing after surgery. X-ray examination 2 wk after surgery indicated fixed magnet positioning, and gastroscopy showed no change in magnet positioning. The magnets were removed using a snare under endoscopy, and TEF was observed. Gross specimens showed well-formed fistulas with a diameter of 6.11 mm ± 0.16 mm (range, 5.92-6.36 mm), which exceeded that in the control group (P < 0.001). Scar formation was observed on the internal surface of fistulas by HE and Masson trichrome staining, and the structure was more regular than that in the control group. CONCLUSION: Use of the modified T-shaped magnet scheme is safe and feasible for establishing TEF and can achieve a more stable and uniform fistula size compared with ordinary magnets. Most importantly, this model offers better controllability, which improves the flexibility of follow-up studies.

N-acetylcysteine combined with insulin therapy can reduce myocardial injury induced by type 1 diabetes through the endoplasmic reticulum pathway.

With the development of Type 1 diabetes mellitus (T1DM), various complications can be caused. Hyperglycemia affects the microenvironment of cardiomyocytes, changes endoplasmic reticulum homeostasis, triggers unfolding protein response and eventually promotes myocardial apoptosis. However, insulin therapy alone cannot effectively combat the complications caused by T1DM. Forty adult beagles were randomly divided into five groups: control group, diabetes mellitus group, insulin group, insulin combined with NAC group, and NAC group. 24-hour blood glucose, 120-day blood glucose, 120-day body weight, and serum FMN content were observed, furthermore, hematoxylin-eosin staining, Periodic acid Schiff reagent staining, and Sirius red staining of the myocardium were evaluated. The protein expressions of GRP78, ATF6, IRE1, PERK, JNK, CHOP, caspase 3, Bcl2, and Bax were detected. Results of the pathological section of myocardial tissue indicated that insulin combined with NAC therapy could improve myocardial pathological injury and glycogen deposition. Additionally, insulin combined with NAC therapy down-regulates the expression of GRP78, ATF6, IRE1, PERK, JNK, CHOP, caspase3, and Bax. These findings suggest that NAC has a phylactic effect on myocardial injury in beagles with T1DM, and the mechanism may be related to the improvement of endoplasmic reticulum stress-induced apoptosis.

Corrigendum: Probiotic characteristics and whole-genome sequence analysis of Pediococcus acidilactici isolated from the feces of adult beagles.

[This corrects the article DOI: 10.3389/fmicb.2023.1179953.].

PEG2000-PLA-based nanoscale polymeric micelles reduce paclitaxel-related toxicity in beagle dogs.

Nanoplatform-based drug delivery plays an important role in clinical practice. Polymeric micellar (Pm) nanocarriers have been demonstrated to reduce the toxicity of paclitaxel in rats and non-small cell lung cancer (NSCLC) patients. However, the underlying toxicological profile needs to be further illustrated. Here, we used beagles as study subjects and sought to further observe the toxicological profile of polymeric micellar paclitaxel (Pm-Pac) via acute toxicity tests and short-term and long-term toxicity tests. The results from the acute toxicity test indicated that the lethal dose of Pm-Pac in beagles was 20-30 mg/kg, and the acute toxicity-targeted organs were the digestive system and immuno-haematopoietic system. The short-term toxicity test suggested that paclitaxel-induced toxicity (peripheral neuropathy toxicity, haemopoietic toxicity, heart system toxicity, and so on) in beagles can be reduced when paclitaxel is delivered via the Pm delivery system. The long-term toxicity test suggested that Pm-Pac can reduce haemopoietic toxicity in beagles. Collectively, this study provides novel insight into the toxicological profile of Pm-Pac in healthy beagles and provides a potential basis for promising clinical combination strategies in the future.

Probiotic characteristics and whole-genome sequence analysis of Pediococcus acidilactici isolated from the feces of adult beagles.

The beneficial effects of lactic acid bacteria are well known and recognized as functional foods that are health benefits for companion animals. This study, for the first time, reports the probiotic properties, safety, and whole-genome sequence of Pediococcus acidilactici GLP06 isolated from feces of beagles. In this study, candidate probiotic bacteria P. acidilactici GLP02 and GLP06 were morphologically characterized and tested for their antimicrobial capacity, tolerance to different conditions (low pH, bile salts, an artificial gastrointestinal model, and high temperature), antibiotic sensitivity, hemolytic activity, cell surface hydrophobicity, autoaggregation activity, and adhesion to Caco-2 cells. P. acidilactici GLP06 showed better probiotic potential. Therefore, P. acidilactici GLP06 was evaluated for in vivo safety in mice and whole-genome sequencing. The results showed, that the supplemented MG06 group (1010 cfu/mL), GLP06 was not only nontoxic to mice, but also promoted the development of the immune system, improved resistance to oxidative stress, and increased the diversity of intestinal microorganisms and the abundance of Lactobacillus. Whole-genome sequencing showed that P. acidilactici GLP06 was 2,014,515 bp and contained 1,976 coding sequences, accounting for 86.12% of the genome, with no drug resistance genes and eight CRISPR sequences. In conclusion, the newly isolated canine-derived P. acidilactici GLP06 had good probiotic potential, was nontoxic to mice and promoted the development of immune organs, improved the biodiversity of the intestinal flora, and had no risk of drug-resistant gene transfer, indicating that P. acidilactici GLP06 can be used as a potential probiotic for the prevention and treatment of gastrointestinal diseases in companion animals.

Pharmacokinetic study of Strongylocentrotus nudus egg polysaccharide in rats and beagles using a 3H-labeling method.

Strongylocentrotus nudus egg polysaccharide (SEP) extracted from sea urchins has potential anticancer activity. However, little is known about its pharmacokinetic properties. To investigate the pharmacokinetics of SEP, it was radiolabeled with tritium. Furthermore, a sensitive, selective, and rapid liquid scintillation counter (LSC) method for quantifying 3H-SEP in biological matrix was validated. The lower quantification limit of the method was 4 Bq. The relative standard deviations (RSDs) of the intra- and inter-day precision were <3.0% and <3.9%, respectively. 3H-SEP was successfully applied to investigate the pharmacokinetics of SEP after intravenous administration of 20, 40, and 80 mg/kg (40 µCi/kg) in rats and 5, 10, and 20 mg/kg (6 µCi/kg) in beagles. The AUC(0-t) of SEP at three different doses was 487.81 ± 39.99 mg/L*h, 1,003.10 ± 95.94 mg/L*h, and 2,188.84 ± 137.73 mg/L*h in rats and 144.12 ± 3.78 mg/L*h, 322.62 ± 28.03 mg/L*h, and 754.17 ± 37.79 mg/L*h in beagles. The terminal elimination half-life (t1/2) of SEP was longer in beagles (204.29 ± 139.34 h) than in rats (35.48 ± 6.04 h). The concentration of SEP in plasma declined rapidly in both rats and beagles. All the study results provide detailed pharmacokinetic profiles of SEP in two kinds of animals, which will be helpful for further development.

Protective Effects of Bacillus subtilis HH2 against Oral Enterotoxigenic Escherichia coli in Beagles.

This study evaluated the protective effect of Bacillus subtilis HH2 on beagles orally challenged with enterotoxigenic Escherichia coli (ETEC). We assessed the physiological parameters and the severity of diarrhea, as well as the changes in three serum immunoglobulins (IgG, IgA, and IgM), plasma diamine oxidase (DAO), D-lactate (D-LA), and the fecal microbiome. Feeding B. subtilis HH2 significantly reduced the severity of diarrhea after the ETEC challenge (p < 0.05) and increased serum levels of IgG, IgA, and IgM (p < 0.01). B. subtilis HH2 administration also reduced serum levels of DAO at 48 h after the ETEC challenge (p < 0.05), but no significant changes were observed in D-LA (p > 0.05). Oral ETEC challenge significantly reduced the richness and diversity of gut microbiota in beagles not pre-fed with B. subtilis HH2 (p < 0.05), while B. subtilis HH2 feeding and oral ETEC challenge significantly altered the gut microbiota structure of beagles (p < 0.01). Moreover, 14 days of B. subtilis HH2 feeding reduced the relative abundance of Deinococcus-Thermus in feces. This study reveals that B. subtilis HH2 alleviates diarrhea caused by ETEC, enhances non-specific immunity, reduces ETEC-induced damage to the intestinal mucosa, and regulates gut microbiota composition.

Magnetic compression anastomosis for reconstruction of digestive tract after total gastrectomy in beagle model.

BACKGROUND: Magnetic compression anastomosis (MCA) is a simple procedure contributing to a reliable anastomosis. However, digestive-tract reconstruction after total gastrectomy using MCA has not yet been reported. AIM: To investigate the feasibility of MCA for simultaneous esophagojejunostomy and jejunojejunostomy after total gastrectomy using beagle dogs. METHODS: Sixteen beagles were randomly divided into an MCA group (study group, n = 8) and a manual-suture anastomosis group (control group, n = 8). Two different magnetic anastomosis devices were used in the study group for esophagojejunal and jejunojejunal anastomoses. Both devices included a pair of circular daughter and parent magnets each. The time of esophagojejunostomy and jejunojejunostomy, postoperative complications, and survival rate of the two groups were compared. The dogs were sacrificed one month after the operation and their anastomotic specimens were obtained. Healing was observed by the naked eye and a light microscope. RESULTS: Digestive-tract reconstruction after total gastrectomy was successfully completed in both groups (survival rate = 100%). In the study group, esophagojejunal and jejunojejunal anastomoses took 6.13 ± 0.58 and 4.06 ± 0.42 min, respectively, significantly lower than those in the control group (15.63 ± 1.53 min, P < 0.001 and 10.31 ± 1.07 min, P < 0.001, respectively). Complications such as bleeding, anastomotic leakage, and anastomotic stenosis were not observed. In the study group, the magnets did not interfere with each other. Discharge time of the jejunojejunal magnetic anastomosis device was 10.75 ± 1.28 d, while that of the esophagojejunal magnetic anastomosis device was 12.25 ± 1.49 d. Residual silk was found in the control group. The study group showed a greater smoothness of the anastomosis than that of the control group. All layers of anastomosis healed well in both groups. CONCLUSION: MCA is a safe and feasible procedure for digestive-tract reconstruction after total gastrectomy in this animal model.

Endoplasmic reticulum stress contributes to pyroptosis through NF-κB/NLRP3 pathway in diabetic nephropathy.

AIMS: Diabetic nephropathy (DN) is known as a major microvascular complication in type 1 diabetes. Endoplasmic reticulum (ER) stress and pyroptosis play a critical role in the pathological process of DN, but their mechanism in DN has been litter attention. MAIN METHODS: Here, we firstly used large mammal beagles as DN model for 120 d to explored the mechanism of endoplasmic reticulum stress-mediated pyroptosis in DN. Meanwhile, 4-Phenylbutytic acid (4-PBA) and BYA 11-7082 were added in the MDCK (Madin-Daby canine kidney) cells by high glucose (HG) treatment. ER stress and pyroptosis related factors expression levels were analyzed by immunohistochemistry, immunofluorescence, western blotting, and quantitative real-time PCR assay. KEY FINDINGS: We identified that glomeruli atrophy, renal capsules were increased, and renal tubules thickened in diabetes. Masson and PAS staining resulted showed that the collagen fibers and glycogen were accumulated in kidney. Meanwhile, the ER stress and pyroptosis-related factors were significantly activated in vitro. Importantly, 4-PBA significantly inhibited the ER stress, which also alleviated the HG-induced pyroptosis in MDCK cells. Furthermore, BYA 11-7082 could reduce the expression levels of NLRP3 and GSDMD genes and proteins. SIGNIFICANCE: These data provide evidence for ER stress contributes to pyroptosis through NF-κΒ/ΝLRP3 pathway in canine type 1 diabetic nephropathy.