PubMed Health⌕ Search

Biomedical subjects

D E Freeman

Publications and source records attributed to D E Freeman.

At least 55 records · Page 3Linked to original sources
PubMed1992

Intraluminal hemorrhage from small intestinal ulceration in two cows.

Two adult Holstein cows were admitted with signs of acute gastrointestinal hemorrhage. Abomasal ulceration was diagnosed tentatively in both cows, but was later ruled out in 1 cow that had an abomasotomy performed through a right paramedian approach. Both cows failed to respond to treatment of blood loss and hypovolemic shock and became recumbent; one cow died and the other was euthanatized. Post-mortem examination determined the source of hemorrhage in both cows to be ulcerated small intestine with severe intraluminal hemorrhage. The cause of ulceration was undetermined. Small intestinal hemorrhage should be considered in cattle with signs of acute gastrointestinal hemorrhage.

Animals↗
PubMed1991

Standing surgery of the neck and thorax.

Many surgical procedures of the head and neck can be safely performed in the standing horse, with easy access to all aspects of the surgical field. Some procedures, such as tracheotomy, are easier to perform with the horse standing with the head in a more natural position than with the horse under general anesthesia. Procedures of the neck and thorax that require evacuation of purulent and necrotic material from confined spaces, such as occur in horses with esophageal ruptures and extensive intrathoracic abscesses, can be done as standing procedures to avoid the risks of general anesthesia on severely debilitated patients.

Animals↗
PubMed1991

Effects of superoxide dismutase on injury induced by anoxia and reoxygenation in equine small intestine in vitro.

Sheets of mucosa from the jejunum of healthy horses were mounted in incubation chambers and bathed with Krebs-Ringer bicarbonate solution. Changes in tissue function and histologic appearance were compared after the following conditions: (1) control conditions for 30 minutes with 95% O2/5% CO2 in the gas phase; (2) same conditions as control, except incubation with superoxide dismutase (300 U/ml) during the last 18 minutes; (3) anoxia for 15 minutes with 95% N2/5% CO2, followed by reoxygenation for 15 minutes; (4) same conditions as 3, except incubation with superoxide dismutase during reoxygenation; and (5) anoxia for 30 minutes. Anoxia reduced the accumulation of radiolabeled L-alanine and caused cell swelling, as indicated by an increase in tissue water and tissue Na contents. Reoxygenation improved the tissue's ability to accumulate L-alanine, but tissue swelling continued after this treatment. Tissue Na content and L-alanine accumulation were restored to control values by reoxygenation with superoxide dismutase in the bathing medium. The grade of structural damage, as indicated by separation of epithelial cells from villi, was equally severe after all, but control, conditions. Superoxide dismutase had no effect on the tissue control conditions. Results of this study suggest that superoxide radicals are involved in the pathogenesis of reperfusion injury in equine jejunal mucosa and that this may be of clinical importance in cases of small intestinal strangulation obstruction.

Alanine↗
PubMed1991

In vitro transport of cycloleucine by equine cecal mucosa.

Mucosa obtained from the cecum of healthy horses and incubated in vitro with 0.1 mM cycloleucine could accumulate this amino acid against an apparent concentration gradient after 60 and 120 minutes. Accumulation by the serosal (antiluminal) surface of the tissue was 3 times greater than accumulation by the mucosal (luminal) surface after 120 minutes (P less than 0.001). Cycloleucine accumulation was significantly reduced by Na deprivation after 60 minutes (P less than 0.05) and 120 minutes (P less than 0.01) and by anoxic conditions after 120 minutes (P less than 0.05). Transmucosal flux from mucosal to serosal surface of the tissue was significantly (P less than 0.05) greater than the opposing flux, but both unidirectional fluxes were small and were largely attributed to passive processes. It was concluded that the most avid transport system for cycloleucine was on the serosal surface of the horse's cecal mucosa, and an active transport system was not evident on the mucosal surface. An active transport system for amino acids on the serosal surface could be explained by the need for crypt cells, the predominant epithelial cell type in the cecum, to obtain nutrients from blood, rather than from the intestinal lumen.

Animals↗
PubMed1991

Evaluation of age, breed, and gender as risk factors for umbilical hernia in horses of a hospital population.

Age, breed, and gender distributions of 168 horses with umbilical hernia treated at the University of Pennsylvania School of Veterinary Medicine were analyzed to determine risk factors for this disease. For the 3 breeds that constituted the largest proportion of hospital and case populations, Thoroughbred, Standardbred, and Quarter Horse, the overall ratio of females to males was 1.63. In a hospital population of the same age group, 0 to 48 months, the female to male ratio was 0.93. Compared with males, females were at significantly higher risk for umbilical hernia after adjustment for breed and age (odds ratio, 2.01; 99% confidence interval, 1.31 to 3.10; P = 0.00002). Of the 2 major breeds, Thoroughbreds were at greater risk than Standardbreds for umbilical hernia, after adjustment for gender and age (odds ratio, 1.80; 99% confidence interval, 1.10 to 2.95; P = 0.0020). The results provide information about a common congenital defect in horses that can be used for future genetic research.

Age Factors↗
PubMed1990

Ileocecal intussusception in horses: 26 cases (1981-1988).

The case records of 26 horses with ileocecal intussusception over a 7-year period were reviewed to determine clinical features of the disease and response to treatment. The median age of horses with ileocecal intussusception was 1 year and ranged from 2 weeks to 19 years. There was no apparent gender or breed predisposition to this disease. An acute form of ileocecal intussusception was diagnosed in 19 horses with signs of moderate to severe abdominal pain of less than or equal to 24 hours' duration, and a chronic form was diagnosed in 7 horses with signs of intermittent, mild to moderate abdominal pain of more than 3 days' duration. Horses with chronic ileocecal intussusception had a history of weight loss or failure to gain weight, slow growth, poor appetite, low-grade pyrexia, and postprandial signs of abdominal pain. At surgery, the involved segments of intestine (intussusceptum and intussuscipiens) in chronic cases were 2 to 10 cm long, and the ileum and much of the distal portion of the jejunum were flaccid, dilated, and thick walled. In the acute cases, the length of involved intestine ranged from 6 to 457 cm. Whereas only 1 of 7 chronic intussusceptions (14%) could be reduced, 9 of 19 (47%) acute intussusceptions were reducible. Surgical treatment included resection and jejunocecostomy (6 horses), partial resection through a cecotomy and a side-to-side jejunocecostomy (2 horses), and a side-to-side ileocecostomy or jejunocecostomy without resection (12 horses, 7 of which had chronic intussusception). Six horses with acute intussusception were euthanatized before or during surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1990

Irradiation alone for supraglottic larynx carcinoma: can CT findings predict treatment results?

Between January 1982 and December 1986, 54 patients with squamous cell carcinoma of the supraglottic larynx were treated for cure with radiation therapy alone; all had a minimum 2-year follow-up. For 31 patients, high-quality pretreatment CT scans were available for review. Scans were retrospectively evaluated by a single radiologist for the percentage of preepiglottic space involvement by tumor, the percentage of paralaryngeal space involvement, and the total tumor volume in cubic centimeters (cc). Volume was measured using a computer digitizer for each CT slice showing tumor. Results showed a significant difference in local control for tumors less than 6 cc versus tumors greater than or equal to 6 cc (15/18 or 83% vs 6/13 or 46%; p = .038). This difference was independent of both T stage and primary site. For T3 lesions, there was a trend toward decreased local control with increasing percentage of preepiglottic space involvement (0-25% = 85% local control; greater than 25% = 60% local control; p = .384); in most cases, however, the amount of preepiglottic space involvement reflected tumor volume (0-25%, 8/12 or 67% of tumors were less than 6 cc; greater than 25%, 7/10 or 70% of tumors were greater than or equal to 6 cc). There was no clear association between degree of paraglottic space involvement and local control. Tumor volume did not correlate with complications of treatment. Because of the limited number of patients in the current study, conclusions should be considered preliminary. However, the data do suggest that pretreatment CT findings, particularly tumor volume, can predict the likelihood of local control with radiation therapy alone for squamous cell carcinoma of the supraglottic larynx.

Carcinoma, Squamous Cell↗
PubMed1989

Guttural pouch tympany: 15 cases (1977-1986).

From 1977 to 1986, guttural pouch tympany was diagnosed in 15 horses--11 fillies and 4 colts. Review of the medical records provided results of physical, microbiologic, radiographic, and endoscopic examinations, treatment protocols, complications, and recovery rate. All affected horses had visible swelling in the parotid gland region, 9 had abnormal respiratory noise, 5 had pneumonia, and 1 had dysphagia. Six horses were treated by median septum fenestration alone, and in 8 horses, this procedure was combined with resection of the mucosal flap at the pharyngeal orifice of the eustachian tube. One horse was not treated. Follow-up information was obtained for 13 horses. Rate of recurrence was 33% (2/6) after fenestration alone and was 29% (2/7) when both procedures were combined. One horse that had been treated using combined procedures died of pneumonia, and a horse treated unsuccessfully by septum fenestration was euthanatized because of persistent dysphagia. Eight horses greater than 2 years old when follow-up information was obtained were reported to be healthy, and 4 of these had raced successfully.

Animals↗
PubMed1989

Wounds of the esophagus and trachea.

Wounds of the esophagus and trachea are uncommon, but closed wounds can be difficult to diagnose and treat. Esophageal wounds are the more serious and can be life-threatening; however, appropriate surgical and medical treatment applied without delay can be successful in some cases, especially in full-thickness longitudinal wounds. Tracheal wounds are usually less severe, but the high risk of iatrogenic injuries to the trachea should be recognized. Also, tracheal injuries can limit the athletic potential of a horse.

Animals↗
PubMed1989

In vitro transport of L-alanine by equine cecal mucosa.

When sheets of mucosa from the cecum of clinically normal horses were incubated in vitro with radiolabeled L-alanine, they could accumulate this amino acid against an apparent concentration gradient after 60 to 150 minutes of incubation. The active transport system for L-alanine was on the serosal surface of the mucosal sheet only. L-Alanine accumulation at 60 minutes was partly inhibited by 20 mM glycine (P less than 0.01), 0.5 mM ouabain (P less than 0.05), and Na deprivation (P less than 0.02). Anoxia for 60 minutes increased L-alanine accumulation, but had adverse effects on cell structure and intracellular cation distributions. Transmucosal fluxes induced a small, but significant (P less than 0.05), net secretion of L-alanine, and the mean (+/- SEM) transmucosal potential difference was 7.3 +/- 0.7 mV over the period of flux measurement. It was concluded that L-alanine was accumulated by the serosal surface of the cecal mucosa, possibly to provide substrate for tissue metabolism. There was no evidence that the cecal mucosa could actively transport this amino acid from the luminal bathing medium.

Alanine↗
PubMed1989

Effect of food deprivation on D-xylose absorption test results in mares.

A D-xylose absorption test was conducted on 4 healthy mares deprived of food for 12, 36, 72, and 96 hours before the test, with a 13- to 15-day adjustment period between each test. Maximal plasma concentrations after 72 and 96 hours of food deprivation were approximately 36% lower than those obtained after the 12- and 36-hour periods (P = 0.0001). Absorption curves were flatter and the decrease in plasma concentration was slower after the 72- and 96-hour periods of food deprivation. The rate of D-xylose absorption (P = 0.0108) and the initial rate of urinary excretion (P = 0.0117) were slower at 72 and 96 hours. Gastric emptying appeared to be progressively delayed with food deprivation, as evident by the delay in peak D-xylose excretion in urine (P = 0.0268). Areas under the plasma concentration-time curves and quantitites of D-xylose excreted in urine were similar for all periods of food deprivation, evidence that the same amounts of D-xylose were absorbed, despite changes in the plasma curve. A 15-hour collection period was sufficient to recover all D-xylose excreted in the urine, and during all periods 9.8 +/- 0.6% (mean +/- SEM) of the oral dose was eliminated in the urine.

Animal Feed↗
PubMed1988

Complications of umbilical hernias in horses: 13 cases (1972-1986).

Of 147 horses treated for umbilical hernias over a 13.5-year period, 13 horses (8.8%) developed complications in association with umbilical defects. Six horses had intestinal incarceration; the incarceration was reduced manually in 3 horses before admission, resolved without treatment in 2 others, and was surgically reduced in one. Herniorrhaphy was performed on 4 of the 5 horses in which the incarceration did not require surgical reduction, and the fifth was managed conservatively. A horse with a parietal hernia and a horse with intestinal stragulation were treated surgically; in the latter, the involved intestine was resected. These 8 horses recovered. Three horses developed an umbilical abscess and 2 developed an enterocutaneous fistula through their umbilical hernias. Four of these horses responded well to surgery, but one horse with an enterocutaneous fistula died from electrolyte imbalances and peritonitis after an unsuccessful attempt at simple closure. The results of this study confirmed that complications of umbilical hernias are rare in horses; however, when they do develop, they may be one of various forms, some of which are insidious in onset.

Animals↗
PubMed1988

Comparison of clinical judgment, Doppler ultrasound, and fluorescein fluorescence as methods for predicting intestinal viability in the pony.

Strangulation obstruction was induced in anesthetized ponies for periods of 2 and 3 hours by clamping 45-cm segments of jejunum and associated veins (venous strangulation obstruction) and arteries and veins (arterial and venous strangulation obstruction). Four segments were studied in each of 7 ponies allowed to survive 12 hours, 2 segments in a pony that was allowed to survive 1 hour, and 1 segment in each of 10 ponies allowed to survive 42 days after the strangulation periods ended. Fifteen minutes after the periods of strangulation obstruction ended, the viability of test segments was assessed by clinical judgment (40 segments), fluorescein fluorescence (40 segments), and Doppler ultrasound (32 segments). Because the test segments were normal at necropsy in long-term survivors, all segments were designated as viable. The overall accuracy of the methods used to predict viability was 88% for Doppler ultrasound and 53% each for clinical judgment and fluorescein fluorescence (P less than 0.005). Failures in the last 2 techniques could be attributed to their tendency to score venous strangulation obstruction segments as nonviable (90% for each). Doppler ultrasound was 94% accurate in these segments.

Animals↗
PubMed1988

Effect of D-glucose on in vitro short-circuit current in neonatal calf jejunum and rabbit ileum.

Thin sheets of mucosa from small intestine of neonatal calves were mounted in incubation chambers for in vitro studies. These mucosal sheets generated a potential difference (PD) of 2.05 +/- 0.02 mV (mean +/- SEM), short-circuit current (SCC) of 23.32 +/- 3.81 microA x cm2, and tissue resistance of 86.22 +/- 4.41 ohms x cm2 (n = 6). Ouabain in the serosal bathing solution caused a sharp decrease in the SCC (P less than 0.01) and PD (P less than 0.005), a decrease in tissue K content (P less than 0.05), and an increase in tissue Na content (P less than 0.05). The mucosa responded to D-glucose by an increase in PD (P less than 0.001) and SCC (P less than 0.001). In vitro methods used in the calf were validated in similar experiments on rabbit ileum.

Animals↗
PubMed1988

Early mucosal healing and chronic changes in pony jejunum after various types of strangulation obstruction.

Strangulation obstruction was induced in anesthetized ponies for periods of 2 and 3 hours by clamping 45-cm segments of jejunum and their veins only (venous strangulation obstruction, VSO) and arteries and veins (arterial and venous strangulation obstruction, AVSO). These types of strangulation obstruction were studied in 4 segments in each of 4 ponies allowed to survive 12 hours (group 1) and in a single segment in each of 10 ponies allowed to survive 42 days (group 2) after the strangulation period ended. On visual inspection, segments subjected to VSO had hemorrhage and edema in the bowel wall and mesentery and were dark purple after all time intervals. They improved slowly after clamps were removed, but remained hemorrhagic and edematous. Segments subjected to AVSO were purple and had mild edema and scattered petechiae in the bowel wall and mesentery. They improved rapidly and closely resembled normal bowel after 5 minutes of reperfusion. On light and scanning electron microscopy, the mucosa of intestine subjected to VSO and AVSO had necrotic, denuded villi 1 hour after the strangulation periods ended. Twelve hours after removal of occlusion devices in group-1 ponies, 4 (25%) segments were unchanged, 4 (25%) had deteriorated, and 8 (50%) had stunted villus remnants partly or completely lined with regenerating epithelium. Separation and detachment of villus tip mucosal cells were seen in 3 of 4 control segments, 1 and 12 hours after the strangulation periods ended.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, General↗
PubMed1985

Complications associated with left dorsal displacement of the large colon in the horse.

Four horses operated on for left dorsal displacement of the large colon (LDDLC) had major intraoperative or postoperative complications. One horse was euthanatized during surgery because of extensive necrosis of the large colon. Three horses that were discharged after surgical correction of LDDLC were readmitted with signs of abdominal pain between 5 weeks and 13 months after surgery. Two horses had recurrence of LDDLC, and the third horse had an omental adhesion attached to and obstructing the pelvic flexure. The displacements were corrected, the adhesion was broken down, and the horses were discharged. One horse was readmitted a third time 16 months after the second surgery and required a third surgical correction of LDDLC.

Animals↗