Mesenchymal Stromal Cell Secretome Is Affected by Tissue Source and Donor Age.

Variation in mesenchymal stromal cell (MSC) function depending on their origin is problematic, as it may confound clinical outcomes of MSC therapy. Current evidence suggests that the therapeutic benefits of MSCs are attributed to secretion of biologically active factors (secretome). However, the effect of donor characteristics on the MSC secretome remains largely unknown. Here, we examined the influence of donor age, sex, and tissue source, on the protein profile of the equine MSC secretome. We used dynamic metabolic labeling with stable isotopes combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify secreted proteins in MSC conditioned media (CM). Seventy proteins were classified as classically secreted based on the rate of label incorporation into newly synthesized proteins released into the extracellular space. Next, we analyzed CM of bone marrow- (n = 14) and adipose-derived MSCs (n = 16) with label-free LC-MS/MS. Clustering analysis of 314 proteins detected across all samples identified tissue source as the main factor driving variability in MSC CM proteomes. Linear modelling applied to the subset of 70 secreted proteins identified tissue-related difference in the abundance of 23 proteins. There was an age-related decrease in the abundance of CTHRC1 and LOX, further validated with orthogonal techniques. Due to the lack of flow cytometry characterization of MSC surface markers, the analysis could not account for the potential effect of cell population heterogeneity. This study provides evidence that tissue source and donor age contribute to differences in the protein composition of MSC secretomes which may influence the effects of MSC therapy.

Epidemiology of Colic: Current Knowledge and Future Directions.

Epidemiologic studies are essential for the generation of evidence-based, preventive health care strategies. This includes ways to minimize colic risk and assist informed decision making concerning diagnosis, treatment, and likely outcomes. It is important to consider that colic is not a simple "disease" but is a syndrome of abdominal pain that encompasses multiple different disease processes, and which is multifactorial in nature. This review focuses on prevention and diagnosis of colic, including specific forms of colic, communications with owners/carers concerning colic risk and management, and areas of future research.

Meta-analysis of the effects of lidocaine on postoperative reflux in the horse.

OBJECTIVE: To determine the efficacy of lidocaine at reducing incidence of postoperative reflux (POR) in horses by using quantitative statistical analysis. STUDY DESIGN: Systematic meta-analytical review. SAMPLE POPULATION: Studies on horses undergoing gastrointestinal surgery for small intestinal lesions, identified by systematic search between 2001 and 2017. METHODS: A search with PubMed/MEDLINE, Web of Science, and Google Scholar was performed, followed by secondary searches of veterinary trade journals and bibliographies of relevant articles. The primary outcome measure for this study was the effect of lidocaine therapy on the odds of POR. Subgroup analysis assessed included the timing of lidocaine therapy, incidence of mortality, and incidence of repeat celiotomy. A meta-analysis was performed with a random effects model, with the effect size calculated as an odds ratio (OR) with 95% confidence intervals (CI). Statistical significance was set at P < .05. RESULTS: Among 1933 peer reviewed publications that met the initial search criteria, 12 relevant studies were available for analysis. Lidocaine was associated with an increased incidence of diagnosis of POR (OR 6.3, 95% CI [1.4, 27.0], P = .01). Horses treated with lidocaine were more likely to survive to discharge (OR 6.8, 95% CI [3.9, 11.7], P < .01). CONCLUSION: Lidocaine was associated with an increased survival rate in horses undergoing exploratory celiotomy for small intestinal disease according to this meta-analysis of the recent literature. CLINICAL SIGNIFICANCE: This body of published evidence provides support to administer lidocaine in horses to improve survival rather than preventing POR.

Effect of fluid media on the mechanical properties of continuous pattern-ending surgeon's, square, and Aberdeen knots in vitro.

OBJECTIVE: To investigate the knot holding capacity (KHC) of pattern-ending square, surgeon's and Aberdeen knots each tied in 4 throw combinations using large gauge suture after exposure to media commonly found in equine abdominal surgery. STUDY DESIGN: In vitro mechanical study. SAMPLE POPULATION: Knotted suture strands (n = 10/group). METHODS: Strands of 2 polydioxanone or 3 polyglactin 910 were exposed to 1 of 4 media for 15 minutes. Control suture strands remained dry. Media used included balanced electrolyte solution, 1% sodium carboxymethylcellulose, equine serum, or equine fat. Pattern-ending knots for the 3 knot configurations were loaded to failure in a linear fashion on a materials testing machine to determine KHC. RESULTS: Surgeon's knots tied using media-exposed 3 polyglactin 910 had a significantly higher KHC than the same dry knots with 5 and 6 throws. Square knots tied using media-exposed to 3 polyglactin 910 had a significantly higher KHC than the same dry knots at 5 throws. Aberdeen knots tied with either media-exposed 2 polydioxanone or 3 polyglactin 910 had a significantly higher KHC than their equivalent dry knots. Aberdeen knots had a superior KHC, while requiring less suture than both surgeon's and square knots. CONCLUSION: Media exposure either had no effect on KHC or significantly improved the KHC of all knots investigated. Based on KHC and knot volume, Aberdeen knots tied using media-exposed 3 polyglactin 910 with 3 throws and 1 turn are recommended to end a continuous suture pattern.

Reconstruction of a Complicated Orbital Depression Fracture with Medial Wall and Globe Repositioning in a Horse: A Collaboration Across Disciplines and Specialties.

OBJECTIVE: To report the surgical reconstruction of a complicated orbital depression fracture in a horse with emphasis on medial wall and globe repositioning. STUDY DESIGN: Clinical report. ANIMALS: A 6 year old Irish Sport Horse gelding. METHODS: The eventer presented with acute, severe orbital trauma and globe displacement. After initial elevation of the depression fractures of the facial bones and reconstruction of the orbit, the globe was recessed secondary to displacement of the medial wall and floor of the orbit within the conchofrontal sinus. A three-dimensional model of the fracture configuration was used for presurgical planning to reposition the globe. During a subsequent surgical procedure, a resorbable plate was placed in the floor of the orbit and the medial orbital wall and globe were repositioned using a sinoscopic approach and stabilized with the placement of tissue expanders within the conchofrontal sinus. The tissue expanders were subsequently removed after 3 weeks under standing sedation. RESULTS: The right globe was successfully repositioned in a more correct anatomical orientation and the horse resumed work 3 months postoperatively, and successfully competed at its previous level 5 months postoperatively. No visual deficits have been reported by the owners. CONCLUSION: Efforts to restore the medial wall and/or floor of the orbit with concurrent globe repositioning should be considered in horses with severe orbital depression fractures that result in abnormal globe position.

Evaluation of the effects of intraabdominal hypertension on equine central venous pressure.

OBJECTIVE: To evaluate the effect of changes in intraabdominal pressure (IAP) on central venous pressure (CVP) in normal horses. DESIGN: Experimental, in vivo study. SETTING: University Teaching Hospital. ANIMALS: Convenience sample of 7 mixed breed horses-5 geldings and 2 mares. INTERVENTIONS: Pneumoperitoneum was induced in horses under standing sedation with carbon dioxide gas using a laparoscopic insufflator for a total of 60 minutes to simulate clinical elevation in IAP. Pressure was increased stepwise to 20 mm Hg over 30 minutes, and maintained at that pressure for 30 minutes to evaluate the effect of sustained intraabdominal hypertension. CVP was obtained from the cranial vena cava, concurrent with pressure obtained from the peritoneal cavity. MEASUREMENTS AND MAIN RESULTS: CVP increased as IAP increased up to 12 mm Hg, and declined as IAP increased further. The changes in CVP over time were significantly different (P < 0.03). Repeated measures correlation was positive, and highest, for mean CVP as IAP increased from 0 to 12 mm Hg (r = .70; 95% CI, .43-.85; P < 0.0001). Correlation of mean CVP with insufflation pressure became negative as IAP increased further from 15 to 20 mm Hg (r = -.47; 95% CI, -.66 to -.21; P = 0.0006). CONCLUSIONS: This report provides preliminary data demonstrating a biphasic trend in equine CVP caused by changes in IAP, similar to that observed in other species. Further investigations are needed to evaluate this trend and to confirm these results in clinical patients.

Evaluation of the effects of medial saphenous venous pressures as an indirect method of measurement of intra-abdominal pressures in the horse.

OBJECTIVE: To evaluate the effect of changes in intra-abdominal pressure (IAP) on medial saphenous venous pressure (MSVP) and hemodynamics in normal horses. DESIGN: Experimental, in-vivo study. SETTING: University Teaching Hospital. ANIMALS: Convenience sample of 7 mixed breed horses; 5 geldings, and 2 mares. INTERVENTIONS: Pneumoperitoneum was induced in horses under standing sedation with carbon dioxide gas using a laparoscopic insufflator for a total of 60 minutes to simulate clinical elevation in IAP. Pressure was increased stepwise to 20 mm Hg over 30 minutes, and maintained at that pressure for 30 minutes to evaluate the effect of sustained intra-abdominal hypertension. The MSVP and vital parameters were recorded, along with direct arterial blood pressure from the transverse facial artery. MEASUREMENTS AND MAIN RESULTS: As IAP increased, MSVP increased in a stepwise manner, in concert with changes in IAP. The consistency in measurement between MSVP and IAP was high (intraclass correlation coefficient = 0.92; P < 0.001) and repeated measures correlation was excellent (r = 0.98; P < 0.001). Heart rate was unchanged over the course of the experiment (P = 0.09), however, respiratory rate increased with increasing IAP (P < 0.001). Arterial blood pressure also increased with insufflation (P < 0.001), with a significant difference at an IAP of 15 mm Hg (P = 0.04). CONCLUSIONS: This report provides preliminary data demonstrating a strong correlation between equine MSVP and changes in IAP, similar to that observed in other species. Further investigations are needed to evaluate this relationship, and to confirm these results in clinical patients.