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Biomedical subjects

David E Freeman

Publications and source records attributed to David E Freeman.

14 recordsLinked to original sources
PubMed2006

Progression of mycosis of the auditory tube diverticulum (guttural pouch) after arterial occlusion in a horse with contralateral temporohyoid osteoarthropathy.

CASE DESCRIPTION: A 6-year-old Appaloosa mare was examined because of inappetance, difficulty eating, and swelling and mucopurulent discharge in the right eye. CLINICAL FINDINGS: Results of a CBC and serum bio-chemical analysis revealed no important findings. Ophthalmologic examination revealed scarring and ulceration of the superficial layers of the cornea. Endoscopic examination of the upper portion of the respiratory tract and auditory tube diverticula (guttural pouches) revealed abnormal thickness of the right stylohyoid bone and a plaque suggestive of mycotic growth on the left internal carotid artery. Radiographic examination revealed right-sided otitis media. Temporohyoid osteoarthropathy in the right guttural pouch and mycosis in the left guttural pouch were diagnosed. TREATMENT AND OUTCOME: Ceratohyoidectomy of the right stylohyoid bone was performed, and the left internal carotid artery was occluded via placement of stainless steel spring embolization coils. The mare regained the ability to eat without difficulty and improved clinically for approximately 4 weeks. However, the mare returned to the medical center 53 days after surgery with left-sided Horner syndrome, atrophy of the right side of the tongue, and a 3-week history of dysphagia and weight loss. Endoscopic evaluation revealed progression of mycotic growth in the left guttural pouch. The mare was euthanatized. CLINICAL RELEVANCE: Although the mycotic lesion in the left guttural pouch was an incidental finding at the time of initial examination, the lesion progressed to cause dysphagia and Horner syndrome after occlusion of the left internal carotid artery, a treatment that is typically associated with resolution of guttural pouch mycosis. Arterial occlusion is not necessarily a reliable method of resolving guttural pouch mycosis.

Animals↗
PubMed2006

Evaluation of the rate of development of septic arthritis after elective arthroscopy in horses: 7 cases (1994-2003).

OBJECTIVE: To determine the rate of development of septic arthritis after elective arthroscopy and evaluate associations between various factors and development of this complication in horses. DESIGN: Retrospective case series. ANIMALS: 682 horses that underwent arthroscopic procedures at the University of Illinois Veterinary Teaching Hospital from 1994 to 2003. PROCEDURES: Information pertaining to signalment, joints treated, whether antimicrobials were administered, and development of postoperative septic arthritis was collected from medical records. Horses with a primary problem of septic arthritis or wounds involving joints were excluded. The following factors were evaluated to determine their roles in joint sepsis: breed, sex, joint, and preoperative and intra-articular administration of antimicrobials. Telephone interviews with clients were used to determine whether unreported septic arthritis had developed. RESULTS: 8 of 932 (0.9%) joints in 7 of 682 (1.0%) horses that underwent arthroscopy developed postoperative septic arthritis. Follow-up information after discharge from the hospital was available for 461 of the 682 horses, and of those, 8 of 627 (1.3%) joints in 7 of 461 (1.5%) horses developed septic arthritis. Breed and joint treated were significant risk factors for development of postoperative septic arthritis, with draft breeds and tibiotarsal joints more likely than others to be affected. Sex, preoperatively administered antimicrobials, and intra-articularly administered antimicrobials were not associated with development of postoperative septic arthritis. CONCLUSIONS AND CLINICAL RELEVANCE: Results can be used for comparison with data from other institutions and surgical facilities. Additional precautions should be undertaken when arthroscopic surgery involves draft breeds and tibiotarsal joints.

Animals↗
PubMed2005

Effects of sodium hyaluronate and methylprednisolone acetate on proteoglycan synthesis in equine articular cartilage explants.

OBJECTIVE: To determine effects of sodium hyaluronate (HA) on corticosteroid-induced cartilage matrix catabolism in equine articular cartilage explants. SAMPLE POPULATION: 30 articular cartilage explants from fetlock joints of 5 adult horses without joint disease. PROCEDURE: Articular cartilage explants were treated with control medium or medium containing methylprednisolone acetate (MPA; 0.05, 0.5, or 5.0 mg/mL), HA (0.1, 1.0, or 1.5 mg/mL), or both. Proteoglycan (PG) synthesis was measured by incorporation of sulfur 35-labeled sodium sulphate into PGs, and PG degradation was measured by release of radiolabeled PGs into the medium. Total glycosaminoglycan (GAG) content in media and explants and total explant DNA were determined. RESULTS: Methylprednisolone acetate caused a decrease in PG synthesis, whereas HA had no effect. Only the combination of MPA at a concentration of 0.05 mg/mL and HA at a concentration of 1.0 mg/mL increased PG synthesis, compared with control explants. Methylprednisolone acetate increased degradation of newly synthesized PGs into the medium, compared with control explants, and HA alone had no effect. Hyaluronate had no effect on MPA-induced PG degradation and release into media. Neither MPA alone nor HA alone had an effect on total cartilage GAG content. Methylprednisolone acetate caused an increase in release of GAG into the medium at 48 and 72 hours after treatment. In combination, HA had no protective effect on MPA-induced GAG release into the medium. Total cartilage DNA content was not affected by treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Our results indicate that HA addition has little effect on corticosteroid-induced cartilage matrix PG catabolism in articular cartilage explants.

Animals↗
PubMed2004

In vitro study of heat production during power reduction of equine mandibular teeth.

OBJECTIVE: To measure the amount of heat generated during 3 methods of equine dental reduction with power instruments. DESIGN: In vitro study. SAMPLE POPULATION: 30 premolar and molar teeth removed from mandibles of 8 equine heads collected at an abbatoir. PROCEDURE: 38-gauge copper-constantan thermocouples were inserted into the lingual side of each tooth 15 mm (proximal) and 25 mm (distal) from the occlusal surface, at a depth of 5 mm, which placed the tip close to the pulp chamber. Group-NC1 (n = 10) teeth were ground for 1 minute without coolant, group-NC2 (10) teeth were ground for 2 minutes without coolant, and group-C2 (10) teeth were ground for 2 minutes with water for coolant. RESULTS: Mean temperature increase was 1.2 degrees C at the distal thermocouple and 6.6 degrees C at the proximal thermocouple for group-NC1 teeth, 4.1 degrees C at the distal thermocouple and 24.3 degrees C at the proximal thermocouple for group-NC2 teeth, and 0.8 degrees C at the distal thermocouple and -0.1 degrees C at the proximal thermocouple for group-C2 teeth. CONCLUSIONS AND CLINICAL RELEVANCE: In general, an increase of 5 degrees C in human teeth is considered the maximum increase before there is permanent damage to tooth pulp. In group-NC2 teeth, temperature increased above this limit by several degrees, whereas in group-C2 teeth, there was little or no temperature increase. Our results suggest that major reduction of equine teeth by use of power instruments causes thermal changes that may cause irreversible pulp damage unless water cooling is used.

Abattoirs↗
PubMed2004

Association between cribbing and entrapment of the small intestine in the epiploic foramen in horses: 68 cases (1991-2002).

OBJECTIVE: To determine whether there was an association between a history of cribbing and epiploic foramen entrapment (EFE) of the small intestine in horses. DESIGN: Retrospective study. ANIMALS: 68 horses examined at the University of Illinois or the University of Liverpool veterinary teaching hospitals. PROCEDURE: For horses examined at the University of Illinois that underwent surgery because of strangulating small intestine lesions, information about cribbing was obtained through telephone calls with owners. For horses examined at the University of Liverpool that underwent surgery for colic for any reason, information about cribbing was obtained through a preoperative questionnaire. RESULTS: 13 of 19 (68%) horses with EFE examined at the University of Illinois had a history of cribbing, compared with only 2 of 34 (6%) horses with other strangulating small intestine lesions (odds ratio, 34.7; 95% confidence interval, 6.2 to 194.6). Similarly, 24 of 49 (49%) horses with EFE examined at the University of Liverpool had a history of cribbing, compared with 72 of 687 (10.5%) horses with colic caused by other lesions (odds ratio, 8.2; 95% confidence interval, 4.5 to 15.1). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that there may be an association between cribbing and EFE in horses, with horses with a history of cribbing more likely to have EFE than horses without such a history.

Animals↗
PubMed2004

Effects of phenylbutazone, indomethacin, prostaglandin E2, butyrate, and glutamine on restitution of oxidant-injured right dorsal colon of horses in vitro.

OBJECTIVE: To study the effects of phenylbutazone, indomethacin, prostaglandin E2 (PGE2), glutamine, and butyrate on restitution of oxidant-injured right dorsal colon of horses in vitro. SAMPLE POPULATION: Right dorsal colon from 9 adult horses euthanatized for reasons other than gastrointestinal tract disease. PROCEDURES: Mucosal segments from the right dorsal colon were injured via exposure to HOCl and incubated in Ussing chambers in solutions containing phenylbutazone, indomethacin, indomethacin and PGE2, glutamine, and butyrate. Transepithelial resistance and mucosal permeability to mannitol were measured, and all mucosal segments were examined histologically. RESULTS: The HOCl-injured mucosa had lower resistance and higher permeability to mannitol, compared with control tissue. Histologic changes were also evident. Resistance of HOCl-injured mucosa recovered partially during the incubation period, and glutamine improved recovery. Phenylbutazone and indomethacin increased resistance, but these increases were not significant. Butyrate and PGE2 had no effects, compared with nontreated HOCl-injured tissues. Mucosal permeability to mannitol was lower in glutamine-treated tissue, compared with nontreated tissue. Histologic changes reflected the resistance and permeability changes. CONCLUSIONS AND CLINICAL RELEVANCE: According to our findings, phenylbutazone and indomethacin do not seem to interfere with restitution of oxidant-injured mucosa of equine colon in vitro, and glutamine could facilitate mucosal restitution.

Analysis of Variance↗
PubMed2003

Sinus disease.

The diagnosis and treatment of diseases of the paranasal sinuses and conchae of horses are complicated by the large size of these structures, their complex anatomy, difficulties of access to them, and the advanced state of many diseases before diagnosis is made. Improved diagnostic methods include nuclear scintigraphy, computed tomography, and direct endoscopy of the sinuses. Treatment of some sinus diseases can be enhanced by access through direct sinus endoscopy for focal lesions, use of large frontal bone flaps for diffuse sinus lesions, standing surgery through a frontal flap for a variety of sinus disorders, and intralesional formalin for progressive ethmoidal hematomas.

Animals↗
PubMed2003

Effects of acetylcysteine and migration of resident eosinophils in an in vitro model of mucosal injury and restitution in equine right dorsal colon.

OBJECTIVES: To evaluate the in vitro protective effects of acetylcysteine and response of resident mucosal eosinophils in oxidant-induced injury to tissues of right dorsal colon of horses. ANIMALS: 9 adult horses. PROCEDURE: Gastrointestinal mucosa was damaged in vitro with 3 mM hypochlorous acid (HOCl), with and without prior exposure to 6mM acetylcysteine. Control tissues were not exposed to HOCl or acetylcysteine. Control and damaged tissues were incubated in Krebs-Ringer-bicarbonate solution and tissue resistance measured during 240 minutes. Tissue permeability to radiolabeled mannitol was also used to assess mucosal barrier integrity. Tissues were examined by light microscopy before and after HOCl exposure and during and after incubation. RESULTS: Exposure to HOCl caused tissue damage and decreased tissue resistance. Restitution did occur during the incubation period. Eosinophils were located near the muscularis mucosae in freshly harvested tissues and migrated towards the luminal surface in response to HOCl-induced injury. Compared with tissues treated with HOCl without acetylcysteine, pretreatment with acetylcysteine prevented HOCl-induced tissue damage, changes in resistance, and histologically detectable eosinophil migration. The permeability to mannitol increased to the same extent in tissues treated with HOCl alone or with acetylcysteine and HOCl. CONCLUSIONS AND CLINICAL RELEVANCE: Eosinophils migrated toward the mucosal surface in equine colon in response to oxidant-induced damage in vitro. This novel finding could be relevant to inflammation in equine colon and a pathophysiologic feature of many colonic diseases. Acetylcysteine protected the mucosa against oxidant-induced injury and may be useful as a treatment option for various gastrointestinal tract disorders in horses.

Acetylcysteine↗
PubMed2002

Clinical signs and treatment of chronic uterine torsion in two mares.

Two mares were evaluated because of chronic uterine torsions of 2 and 4 weeks' duration; both were pyrectic, anemic, tachycardic, and anorectic, had signs of depression, and had an abnormal uterus and contents on transrectal examination. Both mares underwent cesarean section for lysis of adhesions from the uterus to the peritoneum, correction of the torsion, and ovariohysterectomy Both mares recovered with only minor complications and returned to be used as riding horses. Chronic uterine torsion should be considered in mares in late stages of gestation that have vague clinical signs and transrectal palpation findings that are unlike those described in typical cases of uterine torsion. Prognosis for life can be good after treatment by ventral midline celiotomy, cesarean section, correction of the torsion, and ovariohysterectomy.

Animals↗
PubMed2002

In vitro anion transport alterations and apoptosis induced by phenylbutazone in the right dorsal colon of ponies.

OBJECTIVES: To study the functional and structural responses of the right dorsal colon (RDC) of ponies to phenylbutazone (PBZ) in vitro at a concentration that could be achieved in vivo. ANIMALS: 8 adult ponies. PROCEDURE: Short circuit current and conductance were measured in mucosa from the RDC. Tissues incubated with and without HCO3- were exposed to PBZ, bumetanide, or indomethacin. Bidirectional Cl- fluxes were determined. After a baseline flux period, prostaglandin E2 (PGE2) was added to the serosal surfaces and a second flux period followed. Light and transmission electron microscopy were performed. RESULTS: Baseline short circuit current was diminished significantly by PBZ and indomethacin, and increased significantly after addictions of PGE2. After PGE2 was added, Cl- secretion increased significantly in tissues in HCO3- -free solutions and solutions with anti-inflammatory drugs, compared with corresponding baseline measurements and with control tissues exposed to PGE2. Bumetanide did not affect baseline short circuit current and Cl- fluxes. The predominant histologic change was apoptosis of surface epithelial cells treated with PBZ and to a lesser extent in those treated with indomethacin. CONCLUSIONS AND CLINICAL RELEVANCE: Prostaglandin-induced Cl- secretion appeared to involve a transporter that might also secrete HCO3-. Both PBZ and indomethacin altered ion transport in RDC and caused apoptosis; PBZ can damage mucosa through a mechanism that could be important in vivo. The clinically harmful effect of PBZ on equine RDC in vivo could be mediated through its effects on Cl- and HCO3- secretion.

Animals↗
PubMedDate not supplied

Life-threatening hemorrhage from enterotomies and anastomoses in 7 horses.

OBJECTIVE: To report our experience with horses that presumptively had severe intraluminal hemorrhage from enterotomy or anastomosis. STUDY DESIGN: Clinical study. ANIMALS: Six adult horses and 1 adult donkey. METHODS: A retrospective study was conducted at the University of Illinois (April 1994 to December 2001) to determine the clinical course and outcome of horses with melena and/or anemia and evidence of life-threatening hemorrhage from intestinal incisions. Medical records of all horses that had colic surgery were reviewed to determine the proportion of horses with this complication. In addition, horses that fit the same criteria identified in 3 other veterinary clinics were included. RESULTS: Three horses (1.3%) of those that had enterotomy or anastomosis at the University of Illinois and 4 horses from other clinics had complications presumptively related to severe hemorrhage from these intestinal procedures. Melena became evident within 72 hours of surgery and lasted 12 to 96 hours. Six horses had an acute and severe drop in packed cell volume (PCV), increased heart rates, and other signs of acute hemorrhage, and 1 horse had signs of colic postoperatively. Horses were administered intravenous formalin (3 horses) and whole blood transfusions (4 horses). Repeat celiotomy was performed on 2 horses. In 1 of these horses, a bleeding artery was ligated in the edge of the original enterotomy, and, in the other, a 25-cm-diameter intraluminal blood clot was found occluding the pelvic flexure. A horse that had jejunocolostomy for cecal impaction was not treated for hemorrhagic shock but was euthanatized and necropsied. Necropsy revealed blood-filled bowel from the jejunocolostomy to the anus. One of the remaining 6 horses died of enterocolitis and 5 survived to discharge. CONCLUSIONS: Hemorrhage from incisional edges, particularly in the large intestine, should be considered a rare but possibly fatal complication of enterotomy or anastomosis in horses. CLINICAL RELEVANCE: To prevent fatal hemorrhage from incisional edges during enterotomy or anastomosis, large vessels should be ligated at the original surgery, and hemostatic effects of different closure techniques should be considered. No intraoperative or postoperative findings were useful to predict this complication, and response to supportive medical therapy was favorable.

Anastomosis, Surgical↗
PubMedDate not supplied

Extensive nasal septum resection in horses using a 3-wire method.

OBJECTIVE: To describe a surgical technique for, and report outcome after, extensive nasal septum resection in horses with congenital or acquired septal diseases. STUDY DESIGN: Retrospective study. ANIMALS: Horses (5) with nasal septal deformity. METHODS: Under general anesthesia, obstetrical wires were preplaced around the ventral, caudal, and dorsal aspects of the nasal septum by combinations of manual guidance (ventral and caudal wires) and use of a trephine hole on the dorsal mid-line (dorsal and caudal wires). The rostral part of the septum was incised with a scalpel and the ventral, dorsal, and caudal septal incisions were made with the preplaced wires. After septum removal, the nasal cavity packed with a tampon and a temporary tracheotomy was performed. RESULTS: The diseased nasal septum was completely removed in all horses. It was possible to direct the caudal cut at a sufficient angle so that the remaining stump was in a wide part of the nasal passage, where it would have minimal effect on airflow. Four horses healed, and returned to intended use but continued to make a slight respiratory noise during exercise. At 13 months after surgery, 1 horse with a concurrent wry nose was retired from race training after 2 additional surgeries failed to relieve exercise intolerance at high speed. CONCLUSIONS: The 3 wire-cut method of nasal septum resection was technically easy to perform and safe, allowed return to function in most horses, and produced an excellent cosmetic appearance. CLINICAL RELEVANCE: This technique for nasal septum resection allows removal of a large portion of the nasal septum and provides a safe alternative to conventional techniques of nasal septum resection in the horse.

Animals↗