Louise L. Southwood

Evaluation of Ad-BMP-2 for enhancing fracture healing in an infected defect fracture rabbit model

The objective of this study was to evaluate the use of adenoviral transfer of the BMP‐2 gene (Ad‐BMP‐2) for enhancing healing in an infected defect fracture model. A femoral defect stabilized with plates and screws was surgically created in sixty‐four skeletally mature New Zealand white rabbits. Experimental groups were: (1) non‐infected Ad‐luciferase (Ad‐LUC, NONLUC), (2) non‐infected Ad‐BMP‐2 (NONBMP), (3) infected Ad‐LUC (INFLUC), and (4) infected Ad‐BMP‐2 (INFBMP). A sclerosing agent was applied to the ends of the bone at surgery to facilitate the development of osteomyelitis. Fracture healing was evaluated radio‐graphically and histologically. Data were analyzed using an ANOVA, with statistical significance set as p < 0.05.

Current Concepts in Management of Abdominal Adhesions

Adhesions are an important complication after abdominal surgery in horses and foals, especially after small intestinal resection and anastomosis. Prevention therapies used in horses have included nonsteroidal anti-inflammatory drugs, antibiotics, heparin, dimethyl sulfoxide, carboxymethylcellulose, and meticulous surgical technique; however, the ideal surgical technique and prevention therapy has not been determined. Further, treatment of abdominal adhesions has a poor prognosis, emphasizing the need for improvements in prevention methods.

Instrument Sterilization, Skin Preparation, and Wound Management

Recent advances in instrument sterilization include the introduction of gas plasma sterilization and the increased use of glutaraldehyde. Gas plasma sterilization has the advantages of no toxic residue effects, reduced turnover time, and applicability for sterilization of heat- and moisture-sensitive instruments. Chlorhexidine gluconate (4%) appears to be a superior preoperative surgical scrub for both the surgeon and the patient because of its increased antimicrobial efficacy, residual activity, and minimal tissue reactions. There are many new wound dressings and topical medications for treatment of wounds, but the efficacy of most of these preparations has been evaluated only in humans, dogs, and cats. The ideal topical wound preparation and dressing for equine wounds, particularly wounds affecting the distal limb, have not yet been found.

Hepatic and metabolic changes in surgical colic patients: a pilot study

Objective – To determine: (1) changes in blood ammonia, bile acid (BA), bilirubin, triglyceride, and glucose concentrations and liver enzyme activities in perioperative colic patients and (2) the association between these laboratory findings and short-term survival. n n n nDesign – Prospective observational clinical study. n n n nAnimals – Thirty-two adult horses undergoing exploratory celiotomy for colic. n n n nInterventions – None. n n n nMeasurements and Main Results – Blood samples were collected preoperatively and at 24–36 and 72–84 hours postoperatively and analyzed for blood ammonia, BA, bilirubin, triglyceride, and glucose concentrations and sorbitol dehydrogenase (SDH) and gamma glutamyl transferase (GGT) activities. Short-term survival was defined as survival to hospital discharge. Data were analyzed using a Fishers exact test and analysis of variance. Mildly increased blood ammonia concentrations were present in 2 horses at admission. Postoperative blood ammonia concentrations were within reference intervals in all horses. There were increases in liver enzyme activities as well as in BA, triglyceride, and total bilirubin concentrations. Horses with markedly increased admission BA concentrations and SDH activities did not survive. BA concentrations and SDH activities decreased postoperatively. There was no association between GGT activity and survival; GGT activity remained increased postoperatively. Blood triglyceride concentration was increased in almost all horses postoperatively; horses that did not survive had higher triglyceride concentrations at 24–36 hours postoperatively than horses that survived. n n n nConclusion – Alterations in metabolism and hepatobiliary function are common in colic patients. The results of this study provide further prognostic indices for colic patients and highlight areas for improvement in patient management.OBJECTIVEnTo determine: (1) changes in blood ammonia, bile acid (BA), bilirubin, triglyceride, and glucose concentrations and liver enzyme activities in perioperative colic patients and (2) the association between these laboratory findings and short-term survival.nnnDESIGNnProspective observational clinical study.nnnANIMALSnThirty-two adult horses undergoing exploratory celiotomy for colic.nnnINTERVENTIONSnNone.nnnMEASUREMENTS AND MAIN RESULTSnBlood samples were collected preoperatively and at 24-36 and 72-84 hours postoperatively and analyzed for blood ammonia, BA, bilirubin, triglyceride, and glucose concentrations and sorbitol dehydrogenase (SDH) and gamma glutamyl transferase (GGT) activities. Short-term survival was defined as survival to hospital discharge. Data were analyzed using a Fishers exact test and analysis of variance. Mildly increased blood ammonia concentrations were present in 2 horses at admission. Postoperative blood ammonia concentrations were within reference intervals in all horses. There were increases in liver enzyme activities as well as in BA, triglyceride, and total bilirubin concentrations. Horses with markedly increased admission BA concentrations and SDH activities did not survive. BA concentrations and SDH activities decreased postoperatively. There was no association between GGT activity and survival; GGT activity remained increased postoperatively. Blood triglyceride concentration was increased in almost all horses postoperatively; horses that did not survive had higher triglyceride concentrations at 24-36 hours postoperatively than horses that survived.nnnCONCLUSIONnAlterations in metabolism and hepatobiliary function are common in colic patients. The results of this study provide further prognostic indices for colic patients and highlight areas for improvement in patient management.

Characterization of the fecal microbiota of healthy horses

OBJECTIVE To characterize the fecal microbiota of horses and to investigate alterations in that microbiota on the basis of sample collection site (rectum vs stall floor), sample location within the fecal ball (center vs surface), and duration of environmental exposure (collection time). ANIMALS 6 healthy adult mixed-breed mares. PROCEDURES From each horse, feces were collected from the rectum and placed on a straw-bedded stall floor. A fecal ball was selected for analysis immediately after removal from the rectum and at 0 (immediately), 2, 6, 12, and 24 hours after placement on the stall floor. Approximately 250 mg of feces was extracted from the surface and center of each fecal ball, and genomic DNA was extracted, purified, amplified for the V1-V2 hypervariable region of the 16S rDNA gene, and analyzed with a bioinformatics pipeline. RESULTS The fecal microbiota was unique for each horse. Bacterial community composition varied significantly between center and surface fecal samples but was not affected by collection time. Bacterial community composition varied rapidly for surface fecal samples. Individual bacterial taxa were significantly associated with both sample location and collection time but remained fairly stable for up to 6 hours for center fecal samples. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that, for horses, fecal samples for microbiota analysis should be extracted from the center of fecal balls collected within 6 hours after defecation. Samples obtained up to 24 hours after defecation can be analyzed with the realization that some bacterial populations may deviate from those immediately after defecation.