Pharmacokinetics of isavuconazonium sulfate and its active metabolite isavuconazole in healthy dogs.

Invasive fungal infections (IFIs) are growing in importance in veterinary and human medicine. IFIs such as aspergillosis, blastomycosis, coccidioidomycosis and histoplasmosis remain challenging to treat in dogs. Isavuconazole is a novel antifungal medication that, when compared to currently used azoles, has an expanded spectrum of antifungal activity Rudramurthy (2011), Pfaller (2013), Spec (2018), has more predictable pharmacokinetics in humans Desai (2016), Cojutti (2021) and may cause fewer side effects such as liver and renal toxicity Maertens (2016), DiPippo (2018). The pharmacokinetic profile and safety of isavuconazole in dogs has not yet been characterized. The purpose of this study was to evaluate the pharmacokinetics of isavuconazole in healthy dogs that received a single dose of the prodrug isavuconazonium sulfate. Using full crossover design, six healthy beagle dogs received isavuconazonium sulfate at a mean (+/- SD) dose of 20.6 (+/- 2.8) mg/kg orally and 21.8 (+/- 4.2) mg/kg intravenously. Plasma was collected for batched pharmacokinetic analysis of prodrug and metabolite, isavuconazole, by ultra-high-pressure liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The median (Q1-Q3) maximum isavuconazole peak plasma concentration was estimated at 3,876.5 (2,811.0-4,800.0) ng/mL following oral administration, with a median (Q1-Q3) peak level at 1.3 (1.0-2.0) hours. Following intravenous administration, the median (Q1-Q3) isavuconazole peak plasma concentration was estimated at 3,221.5 (2,241.5-3,609.0) ng/mL, with a median (Q1-Q3) peak level at 0.4 (0.3-0.6) hours. The median (Q1-Q3) half-life of isavuconazole was 9.4 (7.0-12.2) hours and 14.0 (8.1-21.7) hours for oral and intravenous routes, respectively. One dog received inadvertent subcutaneous drug administration without any apparent adverse effects. Another dog experienced an anaphylactic reaction following accidental rapid drug infusion. No other drug-related adverse events were observed. At dosages used in this study, healthy dogs achieved isavuconazole plasma levels comparable to human therapeutic targets, and when properly administered the drug was well-tolerated.

A machine learning approach for potential Super-Agers identification using neuronal functional connectivity networks.

INTRODUCTION: Aging is often associated with cognitive decline. Understanding neural factors that distinguish adults in midlife with superior cognitive abilities (Positive-Agers) may offer insight into how the aging brain achieves resilience. The goals of this study are to (1) introduce an optimal labeling mechanism to distinguish between Positive-Agers and Cognitive Decliners, and (2) identify Positive-Agers using neuronal functional connectivity networks data and demographics. METHODS: In this study, principal component analysis initially created latent cognitive trajectories groups. A hybrid algorithm of machine learning and optimization was then designed to predict latent groups using neuronal functional connectivity networks derived from resting state functional magnetic resonance imaging. Specifically, the Optimal Labeling with Bayesian Optimization (OLBO) algorithm used an unsupervised approach, iterating a logistic regression function with Bayesian posterior updating. This study encompassed 6369 adults from the UK Biobank cohort. RESULTS: OLBO outperformed baseline models, achieving an area under the curve of 88% when distinguishing between Positive-Agers and cognitive decliners. DISCUSSION: OLBO may be a novel algorithm that distinguishes cognitive trajectories with a high degree of accuracy in cognitively unimpaired adults. Highlights: Design an algorithm to distinguish between a Positive-Ager and a Cognitive-Decliner.Introduce a mathematical definition for cognitive classes based on cognitive tests.Accurate Positive-Ager identification using rsfMRI and demographic data (AUC = 0.88).Posterior default mode network has the highest impact on Positive-Aging odds ratio.

Retrospective evaluation of the prevalence and risk factors associated with red blood cell transfusions in cats with urethral obstruction (2009-2019): 575 cases.

OBJECTIVE: To evaluate the prevalence of red blood cell (RBC) transfusions and factors associated with the need for transfusion in cases of feline urethral obstruction (FUO). Secondarily, to compare survival to discharge in cats receiving an RBC transfusion versus those that did not. DESIGN: Retrospective, multi-institutional study from 2009 to 2019. SETTING: Four university teaching hospitals. ANIMALS: Six hundred twenty-two total occurrences of FUO in 575 cats. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Medical records were retrospectively reviewed for pertinent information. The overall prevalence of severe anemia (PCV < 0.20 L/L [<20%]) at presentation was 1.0% (6/622). The prevalence of RBC transfusions during hospitalization was 2.1% (13/622). Cats that received an RBC transfusion weighed significantly less than those that did not (4.9 vs 5.8 kg; P = 0.034) and had a lower PCV at presentation (0.30 L/L [30%] vs 0.41 L/L [41%]; P < 0.001). Hospitalization time (240 vs 72 h) and indwelling urinary catheter time (168 vs 48 h) were significantly longer in cats receiving a transfusion compared with those that did not (P < 0.001). Creatinine concentrations were not significantly associated with transfusion administration, while BUN was higher in cats receiving a transfusion (15.35 mmol/L [43 mg/dL] vs. 11.78 mmol/L [33 mg/dL]; P = 0.043). Transfusion rates were significantly higher in cats undergoing perineal urethrostomy (5.5%) compared with those that did not undergo surgery (0.97%; P < 0.001). The overall survival to discharge rate was 96%. Cats not receiving an RBC transfusion were significantly more likely to survive to discharge than those that did (odds ratio: 14.7, 95% confidence interval: 1.8-37; P < 0.001). CONCLUSIONS: FUO is rarely associated with severe anemia and the need for RBC transfusions. In this study, cats receiving an RBC transfusion were less likely to survive to discharge; therefore, requiring a blood transfusion may be associated with a worse prognosis. In addition, the need for surgical intervention was associated with a higher prevalence of RBC transfusions.

Systemic absorption and gastrointestinal adverse effects from topical ketorolac and diclofenac ophthalmic solutions in healthy dogs.

OBJECTIVE: To investigate systemic absorption and gastrointestinal (GI) adverse effects of topical ketorolac 0.5% and diclofenac 0.1% ophthalmic solutions. ANIMALS: 11 healthy purpose-bred Beagles. METHODS: Dogs were randomly assigned to receive either ketorolac (n = 6) or diclofenac (5), 1 drop in both eyes 4 times daily for 28 days. Upper GI endoscopy was performed on days 0 and 29 with mucosal lesion scores (0 to 7) assigned to each region evaluated. Plasma samples were collected on days 14, 21, and 28 for measurement of diclofenac and ketorolac using high-performance liquid chromatography-mass spectrometry. RESULTS: GI erosions and/or ulcers developed in all ketorolac-treated dogs and 1 of 5 diclofenac-treated dogs. Post-treatment mucosal lesion score for the antrum was higher in the ketorolac group than in the diclofenac group (P = .006) but not significantly different for any other region. Post-treatment antral mucosal lesion scores were significantly related to plasma ketorolac concentrations (P < .001). Ketorolac and diclofenac were detected in the plasma at all time points (median ketorolac day 14, 191 ng/mL; day 21, 173.5 ng/mL; and day 28, 179.5 ng/mL; and median diclofenac day 14, 21.1 ng/mL; day 21, 20.6 ng/mL; day 28, 27.5 ng/mL). Vomiting and decreased appetite events were observed uncommonly and were not significantly different between treatment groups. CLINICAL RELEVANCE: GI ulceration and erosion developed after ophthalmic administration of ketorolac and diclofenac, with higher plasma concentrations and more severe GI lesions associated with ketorolac. Clients should be alerted to this potential risk with ophthalmic use and informed to watch for systemic clinical signs that would warrant veterinary reevaluation.

Evaluation of different media compositions promoting hepatocyte differentiation in the canine liver organoid model.

Organoids are 3-dimensional (3D) self-assembled structures capable of replicating the microanatomy and physiology of the epithelial components of their organ of origin. Adult stem cell (ASC) derived organoids from the liver have previously been shown to differentiate into primarily mature cholangiocytes, and their partial differentiation into functional hepatocytes can be promoted using specific media compositions. While full morphological differentiation of mature hepatocytes from ASCs has not yet been reported for any species, the functional differentiation can be approximated using various media compositions. Six differentiation media formulations from published studies on hepatic organoids were used for the differentiation protocol. Target species for these protocols were humans, mice, cats, and dogs, and encompassed various combinations and concentrations of four major hepatocyte media components: Bone morphogenetic protein 7 (BMP7), Fibroblast Growth Factor 19 (FGF19), Dexamethasone (Dex), and Gamma-Secretase Inhibitor IX (DAPT). Additionally, removing R-spondin from basic organoid media has previously been shown to drive the differentiation of ASC into mature hepatocytes. Differentiation media (N = 20) were designed to encompass combinations of the four major hepatocyte media components. The preferred differentiation of ASC-derived organoids from liver tissue into mature hepatocytes over cholangiocytes was confirmed by albumin production in the culture supernatant. Out of the twenty media compositions tested, six media resulted in the production of the highest amounts of albumin in the supernatant of the organoids. The cell lines cultured using these six media were further characterized via histological staining, transmission electron microscopy, RNA in situ hybridization, analysis of gene expression patterns, immunofluorescence, and label-free proteomics. The results indicate that preferential hepatocyte maturation from canine ADC-derived organoids from liver tissue is mainly driven by Dexamethasone and DAPT components. FGF19 did not enhance organoid differentiation but improved cell culture survival. Furthermore, we confirm that removing R-spondin from the media is crucial for establishing mature hepatic organoid cultures.

Randomized comparison between a forced air system and warm water bath for resuscitation of neonatal hypothermic calves with or without oral administration of caffeine.

BACKGROUND: Hypothermia is a cause of neonatal calf death in cold climates. Practical and effective rewarming methods are important for bovine health within affected regions. HYPOTHESIS/OBJECTIVES: To compare the rewarming rate and blood analytes (glucose, lactate, and cortisol) of calves resuscitated with forced air with warm water bath, with or without oral administration of caffeine. ANIMALS: Twenty healthy neonatal Holstein bull calves. METHODS: In this randomized, prospective study, calves born healthy and without history of dystocia were cooled to 32°C rectal temperature then thermally resuscitated using either forced air rewarming or warm water bath (40°C) with or without oral administration of caffeine. Rectal temperatures were used to quantify recovery rate. Measurements of glucose, lactate, and cortisol were recorded for every 2°C change in rectal temperature. RESULTS: Rectal temperature decline (0.03°C per minute) and total cooling time (191.0 ± 33.3 minutes) did not significantly differ among treatment groups. Calves were successfully resuscitated to 38°C by either method. Time required to euthermia using warm water was significantly faster (0.1°C per minute; 64.3 ± 17.8 minute; P < .05) than forced air (0.05°C per minute; 123.1 ± 20.0 minutes). Caffeine had no significant effect on resuscitation rate (P = .14; 95% CI, -0.002 to 0.024) in either treatment; however, caffeine was associated with reduced time to euthermia by 8.3 and 10.8 minutes, respectively. Changes in metabolic variables (glucose, lactate, and cortisol), were inversely related to rectal temperature with no statistical significance among rewarming methods. CONCLUSIONS AND CLINICAL IMPORTANCE: Although warm water submersion is faster, forced air rewarming is an effective alternative for restoration of euthermia.

Effect of amlodipine on the circulating renin-angiotensin-aldosterone system in healthy cats.

BACKGROUND: Systemic hypertension (SH) is a common cardiovascular disease in older cats that is treated primarily with the calcium channel blocker amlodipine besylate (AML). The systemic effect of AML on the classical and alterative arms of the renin-angiotensin-aldosterone system (RAAS) in cats is incompletely characterized. HYPOTHESIS/OBJECTIVES: To determine the effect of AML compared to placebo on circulating RAAS biomarkers in healthy cats using RAAS fingerprinting. ANIMALS: Twenty healthy client-owned cats. METHODS: Cats were administered amlodipine besylate (0.625 mg in toto) or placebo by mouth once daily for 14 days in a crossover design with a 4-week washout period. Plasma AML concentrations and RAAS biomarker concentrations were measured at multiple timepoints after the final dose in each treatment period. Time-weighted averages for RAAS biomarkers over 24 hours after dosing were compared between treatment groups using Wilcoxon rank-sum testing. RESULTS: Compared to placebo, AML treatment was associated with increases in markers of plasma renin concentration (median 44% increase; interquartile range [IQR] 19%-86%; P = .009), angiotensin I (59% increase; IQR 27-101%; P = .006), angiotensin II (56% increase; IQR 5-70%; P = .023), angiotensin IV (42% increase; -19% to 89%; P = .013); and angiotensin 1-7 (38% increase; IQR 9-118%; P = .015). CONCLUSIONS AND CLINICAL IMPORTANCE: In healthy cats, administration of AML resulted in nonspecific activation of both classical and alternative RAAS pathways.

Establishment and characterization of turtle liver organoids provides a potential model to decode their unique adaptations.

Painted turtles are remarkable for their freeze tolerance and supercooling ability along with their associated resilience to hypoxia/anoxia and oxidative stress, rendering them an ideal biomedical model for hypoxia-induced injuries (including strokes), tissue cooling during surgeries, and organ cryopreservation. Yet, such research is hindered by their seasonal reproduction and slow maturation. Here we developed and characterized adult stem cell-derived turtle liver organoids (3D self-assembled in vitro structures) from painted, snapping, and spiny softshell turtles spanning ~175My of evolution, with a subset cryopreserved. This development is, to the best of our knowledge, a first for this vertebrate Order, and complements the only other non-avian reptile organoids from snake venom glands. Preliminary characterization, including morphological, transcriptomic, and proteomic analyses, revealed organoids enriched in cholangiocytes. Deriving organoids from distant turtles and life stages demonstrates that our techniques are broadly applicable to chelonians, permitting the development of functional genomic tools currently lacking in herpetological research. Such platform could potentially support studies including genome-to-phenome mapping, gene function, genome architecture, and adaptive responses to climate change, with implications for ecological, evolutionary, and biomedical research.

Comprehensive characterization of the effect of mineralocorticoid receptor antagonism with spironolactone on the renin-angiotensin-aldosterone system in healthy dogs.

OBJECTIVE: To characterize the dose-exposure-response effect of spironolactone on biomarkers of the classical and alternative arms of the renin-angiotensin-aldosterone system (RAAS) in healthy dogs. ANIMALS: Ten healthy purpose-bred Beagle dogs. PROCEDURES: Study dogs were randomly allocated to 2 spironolactone dosing groups (2 mg/kg PO q24hr, 4 mg/kg PO q24hr). The dogs received 7-day courses of spironolactone followed by a 14-day washout period in a crossover (AB/BA) design. Angiotensin peptides and aldosterone were measured in serum using equilibrium analysis, and plasma canrenone and 7-α-thiomethyl spironolactone (TMS) were quantified via liquid chromatography-mass spectrometry/mass spectroscopy (LC-MS/MS). Study results were compared before and after dosing and between groups. RESULTS: Following spironolactone treatment, dogs had a significant increase in serum aldosterone concentration (P = 0.07), with no statistical differences between dosing groups. Significant increases in angiotensin II (P = 0.09), angiotensin I (P = 0.08), angiotensin 1-5 (P = 0.08), and a surrogate marker for plasma renin activity (P = 0.06) were detected compared to baseline following spironolactone treatment during the second treatment period only. Overall, changes from baseline did not significantly differ between spironolactone dosages. RAAS analytes were weakly correlated (R < 0.4) with spironolactone dosage and plasma canrenone or plasma TMS. There were no adverse clinical or biochemical effects seen at any spironolactone dosage during treatment. CONCLUSIONS: Treatment with spironolactone increased serum aldosterone concentration in healthy dogs and impacted other biomarkers of the classical and alternative arms of the RAAS. There was no difference in effect on the RAAS between 2 and 4 mg/kg/day dosing. Dosage of 4 mg/kg/day was safe and well-tolerated in healthy dogs.

Adult Animal Stem Cell-Derived Organoids in Biomedical Research and the One Health Paradigm.

Preclinical biomedical research is limited by the predictiveness of in vivo and in vitro models. While in vivo models offer the most complex system for experimentation, they are also limited by ethical, financial, and experimental constraints. In vitro models are simplified models that do not offer the same complexity as living animals but do offer financial affordability and more experimental freedom; therefore, they are commonly used. Traditional 2D cell lines cannot fully simulate the complexity of the epithelium of healthy organs and limit scientific progress. The One Health Initiative was established to consolidate human, animal, and environmental health while also tackling complex and multifactorial medical problems. Reverse translational research allows for the sharing of knowledge between clinical research in veterinary and human medicine. Recently, organoid technology has been developed to mimic the original organ's epithelial microstructure and function more reliably. While human and murine organoids are available, numerous other organoids have been derived from traditional veterinary animals and exotic species in the last decade. With these additional organoid models, species previously excluded from in vitro research are becoming accessible, therefore unlocking potential translational and reverse translational applications of animals with unique adaptations that overcome common problems in veterinary and human medicine.

Retrospective evaluation of admission total plasma protein as a predictor of red blood cell transfusion requirement in dogs diagnosed with traumatic and nontraumatic hemoabdomen: 90 dogs (2009-2019).

OBJECTIVE: To evaluate the association of admission total plasma protein (TPP) and the administration of red blood cell transfusions in dogs with diagnosed hemoabdomen. To secondarily evaluate additional point-of-care parameters associated with red blood cell transfusion administration. DESIGN: Retrospective study between 2009 and 2019. SETTING: University veterinary teaching hospital. ANIMALS: Ninety dogs admitted to a university veterinary teaching hospital after a diagnosis of traumatic or nontraumatic hemoabdomen (NTH). MEASUREMENTS AND MAIN RESULTS: Medical records were retrospectively reviewed; signalment, point-of-care diagnostics, and transfusion administration information was recorded. A total of 47 dogs (traumatic hemoabdomen 11/26; NTH 36/64) received packed red blood cell transfusions. For each 1 g/dL unit decrease in TPP, dogs had an increased odds ratio (OR) of 2.14 (95% confidence interval [CI]: 1.44-3.40, P < 0.001) of receiving a red blood cell transfusion. Dogs diagnosed with NTH were more likely to receive a red blood cell transfusion than dogs with a traumatic hemoabdomen (OR: 2.78, 95% CI: 1.11-7.141, P = 0.03). Lower PCV values (OR: 1.08, 95% CI: 1.04-1.12, P < 0.001), bicarbonate values (OR: 1.3, 95% CI: 1.09-1.56, P = 0.003), and base excess (OR: 1.27, 95% CI: 1.1-1.49, P = 0.003) were associated with a higher likelihood of red blood cell transfusion. Additionally, higher lactate (OR: 1.35, 95% CI: 1.16-1.63, P < 0.001) and Acute Patient Physiologic and Laboratory Evaluation (APPLE)fast scores (OR: 1.10, 95% CI: 1.04-1.17, P < 0.001) were associated with increased red blood cell transfusion administration. CONCLUSIONS: Low admission TPP, independent of low PCV, was associated with red blood cell transfusions regardless of underlying cause. For each 1 g/dL unit decrease in TPP on presentation, dogs were approximately 2 times more likely to receive a red blood cell transfusion during hospitalization. Other factors that were associated with increased transfusion administration included presenting PCV, PCV/TPP ratio, bicarbonate, base excess, lactate, and APPLEfast scores.

Retrospective evaluation of toceranib phosphate (Palladia) use in the treatment of feline pancreatic carcinoma.

Objective: To retrospectively assess the biological response in cats with pancreatic carcinoma treated with toceranib phosphate. Animals: Twenty-six client-owned cats. Procedure: Patient information from multiple institutions was solicited via an emailed REDCap survey. For inclusion, cats were required to have a confirmed diagnosis of exocrine pancreatic carcinoma either by histopathology, cytology, or both; to have received treatment with toceranib phosphate; and to have adequate follow-up data for analysis. Results: Twenty cats were treated for gross disease and 6 for microscopic disease/incomplete margins. Clinical benefit (complete response, partial response, or stable disease ≥ 10 wk) was observed in 9/20 cats treated in the gross disease setting (45%; complete response: n = 1, stable disease: n = 8). The remaining 11 cats with gross disease did not respond to toceranib phosphate. In the cats with microscopic disease, response was mixed. The median survival time for all cats was 97 d (range: 1 to 1666 d). Conclusion: Toceranib phosphate was well-tolerated and provided modest clinical benefit to a subset of cats treated. Clinical relevance: Although feline exocrine pancreatic carcinoma continues to be a challenging disease to treat, toceranib phosphate appeared to provide potential clinical benefit.

Évaluation rétrospective de l'utilisation du phosphate de tocéranib (Palladia) dans le traitement du carcinome pancréatique félin. Objectif: Évaluer rétrospectivement la réponse biologique chez les chats atteints d'un carcinome pancréatique traités par le phosphate de tocéranib. Animaux: Vingt-six chats appartenant à des clients. Procédure: Les informations sur les patients de plusieurs institutions ont été sollicitées via une enquête REDCap envoyée par courriel. Pour être inclus, les chats devaient avoir un diagnostic confirmé de carcinome pancréatique exocrine, soit par histopathologie, soit par cytologie, soit par les deux; avoir reçu un traitement par phosphate de tocéranib; et disposer de données de suivi adéquates pour l'analyse. Résultats: Vingt chats ont été traités pour une maladie macroscopique et six pour une maladie microscopique/marges incomplètes. Un bénéfice clinique (réponse complète, réponse partielle ou maladie stable ≥ 10 semaines) a été observé chez 9 chats sur 20 traités dans le cadre d'une maladie macroscopique (45 %; réponse complète: n = 1, maladie stable: n = 8). Les 11 chats restants atteints d'une maladie macroscopique n'ont pas répondu au phosphate de tocéranib. Chez les chats atteints d'une maladie microscopique, la réponse était mitigée. La durée médiane de survie pour tous les chats était de 97 jours (écart: 1 à 1666 jours). Conclusion: Le phosphate de tocéranib a été bien toléré et a apporté un bénéfice clinique modeste à un sous-ensemble de chats traités. Pertinence clinique: Bien que le carcinome pancréatique exocrine félin continue d'être une maladie difficile à traiter, le phosphate de tocéranib semble offrir un bénéfice clinique potentiel.(Traduit par Dr Serge Messier).

Exploring the benefits of in-diet versus repeated oral dosing of saracatinib (AZD0530) in chronic studies: insights into pharmacokinetics and animal welfare.

Saracatinib/AZD0530 (SAR), a Src tyrosine kinase inhibitor, mitigates seizure-induced brain pathology in epilepsy models upon repeated oral dosing. However, repeated dosing is stressful and can be challenging in some seizing animals. To overcome this issue, we have incorporated SAR-in-Diet and compared serum pharmacokinetics (PK) and brain concentrations with conventional repeated oral dosing. Saracatinib in solution or in-diet was stable at room temperature for >4 weeks (97 ± 1.56%). Adult Sprague Dawley rats on SAR-in-Diet consumed ~1.7 g/day less compared to regular diet (16.82 ± 0.6 vs. 18.50 ± 0.5 g/day), but the weight gain/day was unaffected (2.63 ± 0.5 g/day vs. 2.83 ± 0.2 g/day). Importantly, we achieved the anticipated SAR dose range from 2.5-18.7 mg/kg of rat in response to varying concentrations of SAR-in-Diet from 54 to 260 ppm of feed, respectively. There was a strong and significant correlation between SAR-in-Diet dose (mg/kg) and serum saracatinib concentrations (ng/ml). Serum concentrations also did not vary significantly between SAR-in-Diet and repeated oral dosing. The hippocampal saracatinib concentrations derived from SAR-in-Diet treatment were higher than those derived after repeated oral dosing (day 3, 546.8 ± 219.7 ng/g vs. 238.6 ± 143 ng/g; day 7, 300.7 ± 43.4 ng/g vs. 271.1 ± 62.33 ng/g). Saracatinib stability at room temperature and high serum and hippocampal concentrations in animals fed on SAR-in-Diet are useful to titer the saracatinib dose for future animal disease models. Overall, test drugs in the diet is an experimental approach that addresses issues related to handling stress-induced variables in animal experiments.

Effect of the Probiotic Bacillus subtilis DE-CA9TM on Fecal Scores, Serum Oxidative Stress Markers and Fecal and Serum Metabolome in Healthy Dogs.

BACKGROUND: There is increasing interest in the use of Bacillus species as probiotics since their spore-forming ability favors their survival in the acidic gastric environment over other probiotic species. The subsequent germination of B. subtilis to their vegetative form allows for their growth in the small intestine and may increase their beneficial effect on the host. B. subtilis strains have also previously been shown to have beneficial effects in humans and production animals, however, no reports are available so far on their use in companion animals. STUDY DESIGN: The goal of this study was therefore to investigate the daily administration of 1 × 109 cfu DE-CA9TM orally per day versus placebo on health parameters, fecal scores, fecal microbiome, fecal metabolomics, as well as serum metabolomics and oxidative stress markers in ten healthy Beagle dogs in a parallel, randomized, prospective, placebo-controlled design over a period of 45 days. RESULTS: DE-CA9TM decreased the oxidative status compared to controls for advanced oxidation protein products (AOPP), thiobarbituric acid reactive substances (TBARS) and reactive oxygen metabolites (d-ROMS), suggesting an antioxidant effect of the treatment. Fecal metabolomics revealed a significant reduction in metabolites associated with tryptophan metabolism in the DE-CA9TM-treated group. DE-CA9TM also significantly decreased phenylalanine and homocysteine and increased homoserine and threonine levels. Amino acid metabolism was also affected in the serum metabolome, with increased levels of urea and cadaverine, and reductions in N-acetylornithine in DE-CA9TM compared to controls. Similarly, changes in essential amino acids were observed, with a significant increase in tryptophan and lysine levels and a decrease in homocysteine. An increase in serum guanine and deoxyuridine was also detected, with a decrease in beta-alanine in the animals that ingested DE-CA9TM. CONCLUSIONS: Data generated throughout this study suggest that the daily administration of 1 × 109 cfu of DE-CA9TM in healthy Beagle dogs is safe and does not affect markers of general health and fecal scores. Furthermore, DE-CA9TM administration had a potential positive effect on some serum markers of oxidative stress, and protein and lipid metabolism in serum and feces.

Phenylbutazone concentrations in synovial fluid following administration via intravenous regional limb perfusion in the forelimbs of six adult horses.

Background: Pain management is critical to equine welfare with non-steroidal anti-inflammatory drugs (NSAID) commonly used in horses. However, systemic NSAID use is limited by harmful gastrointestinal and renal side effects. Intravenous regional limb perfusion (IVRLP) is a technique used in horses that produces high, local antibiotic concentrations while limiting systemic circulation. NSAID-IVRLP would be a novel method of local pain management while limiting systemic NSAID side effects. To date, NSAID-IVRLP administration has not been reported in horses. This study aimed to identify the pharmacokinetics and local complications associated with using the NSAID phenylbutazone (PBZ) for IVRLP in six standing adult horses. Methods: PBZ-IVRLP, at a dose of 2.2 mg/kg PBZ, was performed in a randomly assigned forelimb cephalic vein in 6 standing, healthy adult horses. A placebo-IVRLP was performed in the contralateral forelimb for comparison. Systemic serum and radiocarpal joint synovial fluid PBZ concentrations were identified at various timepoints (before IVRLP T-0 h, just after tourniquet removal T-0.5, 1.5, 3, 5, 12, 16, and 24 h post IVRLP) for non-compartmental pharmacokinetic analysis and concentration over time curves. Local complications associated with PBZ-IVRP were evaluated for up to 7 days following PBZ-IVRLP using physical and ultrasonographic assessment. On day 7 horses were humanely euthanized with histology performed on both forelimbs at PBZ-IVRLP and placebo-IVRLP administration sites. Results: Non-compartmental pharmacokinetics for PBZ, and its major metabolite oxyphenbutazone (OBZ), were determined for serum and synovial fluid. Synovial PBZ concentrations (mean ± SD; 1.9 ± 2.1 µg/mL) were significantly lower (p = 0.03; CI,0.46-7.36) than serum PBZ concentrations (5.8 ± 5.1 µg/mL) at any time point. Physical and ultrasonographic measurements were not significantly different between PBZ- and placebo-IVRLP forelimbs. The most common histologic findings included focal deep dermal/subcutaneous hemorrhage and edema. Two horses showed perivasculitis and one horse showed a resolving thrombus in the cephalic vein of the PBZ-IVRLP limb. This horse also had severe perivasculitis and fibrinosuppurative dermatitis/panniculitis in the placebo-IVRLP limb. Conclusion: PBZ-IVRLP pharmacokinetics at a 2.2 mg/kg dose showed no benefit compared to systemic PBZ administration in standing adult horses. Local complications associated with PBZ-IVRLP were similar to placebo-IVRLP on physical and ultrasonographic evaluation.

Retrospective comparison of outcomes in septic peritonitis with or without closed-suction abdominal drainage in 115 dogs (2009-2019).

Septic peritonitis is a serious medical condition affecting veterinary patients and post-operative care remains controversial. This study aimed to evaluate and compare post-operative outcomes of dogs treated for septic peritonitis with and without surgically placed closed-suction abdominal drains. Medical records were retrospectively searched from the years 2009 through 2019 and one hundred and fifteen dogs with confirmed septic peritonitis treated with exploratory laparotomy were included. Twenty-two dogs had closed suction drains placed and ninety-three dogs were managed without post-operative drainage. Overall survival to discharge rate of patients in this study was 72%. The survival rate of patients with an abdominal drain was 53% compared to 77% in patients without a drain (P < 0.0001). Dogs with a higher APPLEfast score were significantly more likely to have a drain placed at the time of surgery (P = 0.0277). Dogs that had a closed-suction drain were significantly more likely to be given colloidal support compared to dogs managed without drainage (P = 0.0342). Based on this data, closed-suction drainage post-operatively for treatment of septic peritonitis was not associated with a more favorable survival outcome. The use of a severity of illness score, APPLEfast, did not show a correlation between severity of illness and survival outcome but did demonstrate a correlation between illness severity and placement of a closed-suction drain. Closed-suction drainage post-operatively increased the likelihood of receiving colloidal support, but due to the retrospective nature of the study and the lack of standardized post-operative nutritional support, definitive conclusion that post-operative drainage alone led to increased colloidal support cannot be made in this study.

OrganoidChip facilitates hydrogel-free immobilization for fast and blur-free imaging of organoids.

Organoids are three-dimensional structures of self-assembled cell aggregates that mimic anatomical features of in vivo organs and can serve as in vitro miniaturized organ models for drug testing. The most efficient way of studying drug toxicity and efficacy requires high-resolution imaging of a large number of organoids acquired in the least amount of time. Currently missing are suitable platforms capable of fast-paced high-content imaging of organoids. To address this knowledge gap, we present the OrganoidChip, a microfluidic imaging platform that incorporates a unique design to immobilize organoids for endpoint, fast imaging. The chip contains six parallel trapping areas, each having a staging and immobilization chamber, that receives organoids transferred from their native culture plates and anchors them, respectively. We first demonstrate that the OrganoidChip can efficiently immobilize intestinal and cardiac organoids without compromising their viability and functionality. Next, we show the capability of our device in assessing the dose-dependent responses of organoids' viability and spontaneous contraction properties to Doxorubicin treatment and obtaining results that are similar to off-chip experiments. Importantly, the chip enables organoid imaging at speeds that are an order of magnitude faster than conventional imaging platforms and prevents the acquisition of blurry images caused by organoid drifting, swimming, and fast stage movements. Taken together, the OrganoidChip is a promising microfluidic platform that can serve as a building block for a multiwell plate format that can provide high-throughput and high-resolution imaging of organoids in the future.

Changes of Enterocyte Morphology and Enterocyte: Goblet Cell Ratios in Dogs with Protein-Losing and Non-Protein-Losing Chronic Enteropathies.

This study aimed to assess the morphometry of enterocytes as well as the goblet cell-to-enterocyte ratio in different intestinal segments of dogs with chronic enteropathies (CE). Histopathological intestinal samples from 97 dogs were included in the study (19 healthy juveniles, 21 healthy adults, 24 dogs with protein-losing enteropathy (PLE), and 33 CE dogs without PLE). Healthy adult small intestinal enterocytes showed progressively reduced epithelial cell height in the aboral direction, while juvenile dogs showed progressively increased epithelial cell height in the aboral direction. CE dogs had increased epithelial cell height in the duodenum, while PLE dogs had decreased epithelial cell heights compared to healthy adult dogs. Both the CE and PLE dogs showed decreased enterocyte width in the duodenal segment, and the ileal and colonic enterocytes of CE dogs were narrower than those of healthy adult dogs. CE dogs had a lower goblet cell-to-enterocyte ratio in the colon segment compared to healthy dogs. This study provides valuable morphometric information on enterocytes during canine chronic enteropathies, highlighting significant morphological enterocyte alterations, particularly in the small intestine, as well as a reduced goblet cell-to-enterocyte ratio in the colon of CE cases compared to healthy adult dogs.

Increased drug concentration and repeated eye drop administration as strategies to optimize topical drug delivery: A fluorophotometric study in healthy dogs.

OBJECTIVES: Determine tear film kinetics with different fluorescein concentrations and repeated eye drop administration at various time intervals. ANIMALS STUDIED: Six healthy Beagles. PROCEDURES: Six experiments were conducted on separate days: single eye drop administration (control) or two separate eye drops administered at 30 s, 1, 2, 5, and 10 min intervals. For each experiment, one eye received 0.3% fluorescein solution while the other eye received 1% fluorescein solution, and tear fluid was collected with capillary tubes at 0, 1, 5, 10, 20, 30, 40, 50, 60, 90, 120, and 180 min. Fluorescein concentrations were measured using automated fluorophotometry. RESULTS: Compared with 0.3% solution, eyes receiving 1% fluorescein solution had significantly higher tear film concentrations (p ≤ .046) and the area-under-the-fluorescein-time curve was twofold greater (p = .005). Compared with control: (i) Tear film concentrations were significantly higher for up to 20 min when repeating administration 30 s to 5 min after the first drop (p ≤ .006); (ii) The highest increase in area-under-the-curve was obtained with 2 and 5 min intervals for 0.3% (+109%-130%) and 1% solutions (+153%-157%); (iii) The highest increase in median precorneal retention time (defined as tear film concentration < 5% from baseline values) was obtained with 5 min intervals for 0.3% (55 min vs. 15 min in control) and 2-5 min intervals for 1% solutions (50 min vs. 25 min in control). CONCLUSIONS: Drug delivery to the ocular surface can be enhanced by using more concentrated formulations and/or by repeating eye drop administration 2-5 min after the first dose.