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Biomedical subjects

D E Freeman

Publications and source records attributed to D E Freeman.

At least 37 records · Page 2Linked to original sources
PubMed1997

Surgery of the small intestine.

Although earlier reports describe a poor prognosis for small intestinal surgery in the horse, there is growing evidence that the short-term survival rate can exceed 80%. In addition to advancements in surgery and aftercare, early referral contributes considerably to the improved prognosis. Surgical procedures that restore anatomic and physiologic continuity to close to normal can minimize postoperative complications. Jejunojejunostomy carries a better prognosis than jejunocecostomy, probably because the latter involves anastomosis between two intestinal segments with dissimilar functions. Careful technique can reduce the prevalence of complications, such as postoperative ileus and serosal adhesions.

Anastomosis, Surgical↗
PubMed1997

Diseases and surgery of the large colon.

Displacements and intraluminal obstructions of the large colon carry a good to excellent prognosis for long-term recovery, and surgery for these diseases is rarely followed by short-term or long-term complications. Entrapment of the large colon over the renosplenic ligament is amenable to medical therapies so that surgery can be avoided in many cases. However, preoperative diagnosis of all nonstrangulating diseases of the large colon can be difficult. Vascular diseases of the large colon, such as thromboembolic diseases and large colon volvulus, are more difficult to treat and carry a poorer prognosis for survival.

Animals↗
PubMed1997

Management of rectal tears.

Rectal tears have important medicolegal implications, and severe tears have a poor prognosis. Prompt diagnosis, immediate application of first aid measures, early referral, use of appropriate definitive treatments, and aggressive aftercare will improve the prognosis. The grade of rectal injury will determine the definitive treatment, but there are few guidelines to determine which treatment is best in each case. Bypass procedures, such as colostomy and indwelling rectal liner, have their own advantages and disadvantages, but can facilitate healing and prevent life-threatening complications if they are used with minimum delay. Suture of the tear can be difficult, but should be attempted to hasten healing and to prevent progression of the tear to a more severe injury.

Animals↗
PubMed1997

Effects of flunixin meglumine on short circuit current in equine colonic mucosa in vitro.

OBJECTIVES: To study the effect of flunixin meglumine on short circuit current (Isc) in equine right ventral colon in vitro. SAMPLES: Intestinal mucosa from healthy horses and ponies. PROCEDURE: Isc was measured in mucosa from the right ventral colon mounted in Ussing chambers. In experiment 1, collection and incubation solutions were: control (no additions); flunixin meglumine, 4 micrograms/ml; indomethacin, 10(-6) M; and flunixin meglumine (4 micrograms/ml) with 10(-6) M prostaglandin E2. In experiment 2, incubation conditions were: control [plain Krebs-Ringer bicarbonate [KRB] solution]; flunixin meglumine, 4 micrograms/ml in KRB; chloride-free buffer solution; flunixin meglumine (4 micrograms/ml) in a chloride-free buffer solution; and plain KRB with 10(-6) M prostaglandin E2. In experiment 3, tissue from 3 groups (n = 6 each) of animals: controls, physiologic saline solution given IV at 10 minutes before euthanasia; flunixin meglumine (1.1 mg/kg of body weight, IV) given at 10 minutes before euthanasia; and treatment similar to controls, except that tissues were incubated with 8 micrograms of flunixin meglumine/ml of bathing medium. RESULTS: Flunixin meglumine and indomethacin reduced Isc to approximately a third of control current (P < 0.05), but coincubation with flunixin meglumine and 10(-5) M prostaglandin E2 restored Isc close to the control value. Incubation with 10(-6) M prostaglandin E2 alone did not change Isc. When chloride was substituted with isethionate, flunixin meglumine had no effect on Isc. Flunixin meglumine given before euthanasia or included at a concentration of 8 micrograms/ml in all tissue preparation and incubation solutions reduced Isc (P < 0.05). CONCLUSIONS: Flunixin meglumine given IV or added to bathing solutions decreased Isc in equine right ventral colon by a mechanism that appeared to involve prostaglandin-mediated chloride secretion. CLINICAL RELEVANCE: Our results suggest that flunixin meglumine given IV to horses at recommended doses could alter putative effects of colonic prostaglandins.

Animals↗
PubMed1994

Radiotherapy alone for carcinoma of the vagina: the importance of overall treatment time.

PURPOSE: Review treatment results, complications, and the importance of overall treatment time for carcinoma of the vagina treated with radiotherapy alone. METHODS AND MATERIALS: Between October 1964 and October 1990, 65 patients with histologically confirmed carcinoma of the vagina received definitive radiotherapy at the University of Florida. All patients had a minimum 2-year follow-up. Most patients were treated with a combination of external-beam radiotherapy and brachytherapy. The probability of pelvic control, cause-specific survival, and complications was calculated and multivariate analyses were performed. The log-rank test was used to determine significance levels between the curves. RESULTS: The 5-year cause-specific survival rates were, Stage 0 (six patients), 100%; Stage I (17 patients), 94%; Stage IIA (six patients), 80%; Stage IIB (ten patients), 39%; Stage III (twn patients), 79%; and Stage IVA (six patients), 62%. The pelvic control rates at 5 years were: Stage 0, 100%; Stage I, 87%; Stage IIA, 88%; Stage IIB, 68%; Stage III, 80%; and Stage IVA, 67%. The parameters of stage, patient age, total dose to primary site, and overall treatment time were evaluated in a multivariate analysis. The single most important predictor of pelvic control was overall treatment time. If the entire course of radiotherapy (external beam + implant) was completed within 9 weeks (63 days), the pelvic control rate was 97%. The pelvic control rate was only 54% if treatment time extended beyond 9 weeks (p = .0003). The rate of severe complications was 12%, and the incidence increased with increasing total primary dose. CONCLUSION: Radiotherapy alone can cure a significant proportion of patients with carcinoma of the vagina. Treatment should be completed without significant interruption, preferably within 9 weeks.

Brachytherapy↗
PubMed1994

Stage III ovarian carcinoma: an analysis of treatment results and complications following hyperfractionated abdominopelvic irradiation for salvage.

PURPOSE: Patients with persistent disease found at laparotomy following platinum-based chemotherapy for Stage III ovarian carcinoma have a remote chance of cure with second-line chemotherapy or conventional radiotherapy. To decrease relapse rates and improve tolerance, we have used twice-daily radiotherapy in 28 such patients. METHODS AND MATERIALS: Twenty-eight patients with Stage III epithelial ovarian carcinoma were treated with curative intent at the University of Florida with hyperfractionated, continuous-course radiotherapy for persistent disease at laparotomy after administration of platinum-based chemotherapy. All patients received .8 Gy per fraction, twice daily, to a mean total dose of 30.2 Gy to the whole abdomen and pelvis; 20 patients had additional radiotherapy to the pelvis (mean, 14.54 Gy). All patients had undergone two to four (mean, 2.6) laparotomies for ovarian carcinoma and had received 6-28 (mean, 12) cycles of chemotherapy before irradiation. RESULTS: With a 2-year minimum follow-up, survival rates at 1, 2, and 5 years were as follows: absolute survival, 79%, 50%, 21%; relapse-free survival, 52%, 36%, 19%. For the 11 patients with no evidence of gross residual disease after the second-look laparotomy, the absolute survival rates were 100%, 73%, and 27%. This was superior to the rates of 65%, 34%, and 18% for the 17 patients who had gross residual disease. Only two patients required treatment breaks. Four patients required surgical intervention for small-bowel obstruction, which in two cases revealed recurrent disease. Two patients died of treatment-related complications. Twenty-two of 23 failures occurred in the abdomen and/or pelvis. CONCLUSION: Although most patients eventually relapse, a small percentage have had a prolonged disease-free interval. Since treatment was relatively well tolerated, escalation of the dose of hyperfractionated abdominopelvic irradiation is being investigated.

Carcinoma↗
PubMed1994

Effects of heparin, venous strangulation obstruction of the small intestine, and reperfusion of the small intestine on plasma diamine oxidase activity in horses.

Diamine oxidase (DAO), an enzyme of small intestinal origin, is released from mucosal storage sites by IV administration of heparin, to yield the plasma postheparin DAO (PHD) curve. The PHD curve is diminished when mucosal surface area is lost, and baseline (without heparin) plasma DAO activity increases when mucosal storage sites are damaged. Plasma DAO activity was measured after 2 doses of heparin were administered IV in healthy, conscious horses. In anesthetized horses, the PHD curve was studied: during sham small intestinal surgery, and during venous strangulation obstruction (VSO) of the distal 50% of the small intestine. In a third group of anesthetized horses, baseline plasma DAO activity (without heparin) was measured during VSO of the distal 50% of the small intestine for 90 minutes, followed by reperfusion for 90 minutes. Postheparin plasma DAO curves in conscious horses were similar to those reported in other species. Horses with VSO had a similar PHD curve as did sham-operated controls at all times, except at 15 minutes, when plasma DAO activity was significantly (P < 0.05) greater in the VSO group. Horses with VSO and reperfusion had no change in baseline plasma DAO activity throughout the study. Peritoneal fluid DAO activity remained low throughout the study, but increased slightly in horses with VSO that received heparin, possibly because of DAO from extravasated blood in the peritoneal fluid. Results indicated that the plasma DAO response to IV administered heparin in horses is similar to that in other mammals, but, unlike other species, baseline and postheparin DAO activities did not change as expected after small intestinal vascular obstruction and mucosal injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Amine Oxidase (Copper-Containing)↗
PubMed1993

Disseminated Halicephalobus deletrix infection in a horse.

A 13-year-old Quarter Horse gelding was referred for evaluation of a draining tract and fracture of the right hemimandible of 4 weeks' duration. Two days prior to admission, the horse had developed pigmenturia. Radiography of the mandible revealed a fracture of the vertical ramus of the right hemimandible, loss of the right lower second premolar, and osteomyelitis involving an extensive portion of the hemimandible. Ultrasonography of the left kidney revealed loss of normal renal architecture. Histologic examination of tissue obtained from the right hemimandible revealed granulomatous osteomyelitis and multiple metazoan parasites identified as Halicephalobus deletrix. The horse was treated with antimicrobial and deworming agents, and the mandible was surgically debrided. The horse became atactic 8 days after surgery and was euthanatized. Necropsy identified parasitic migration in the right hemimandible, kidneys, and CNS.

Animals↗
PubMed1993

Kinetic analysis of D-xylose absorption after its intragastric administration to mares deprived of food.

Multicompartmental analysis was applied to study the kinetics of D-xylose distribution after its intragastric administration to healthy mares deprived of food for 12, 36, 72, and 96 hours. Disposition of D-xylose was described by a 5-compartment model. Maximal plasma D-xylose concentration was similar for 12 and 36 hours of food deprivation and was greater (P = 0.0001) than the values for 72 and 96 hours. Peak concentration of D-xylose appeared progressively later as food deprivation proceeded (P = 0.0001). Fractional rate of transfer (k1,6) was less after 96 hours of food deprivation, compared with 12 hours (P = 0.0001), and percentage of D-xylose absorbed was reduced (P = 0.0441) after food deprivation. Fractional rate of transfer (k6,5), representing gastric emptying, tended to progressively decrease with food deprivation. Results indicated that formal kinetic analysis can be applied to D-xylose absorption kinetics in horses. Reduction in the extent of D-xylose absorption after food deprivation may be partly caused by decreased rate of D-xylose absorption across the small intestinal mucosa, but other factors, such as gastric emptying and nonabsorptive losses, may also be involved.

Analysis of Variance↗
PubMed1993

In vitro concentrative accumulation of D-xylose by jejunum from horses and rabbits.

Accumulation of D-xylose by jejunal mucosa from healthy horses and rabbits was studied in vitro. When tissue sheets were incubated with 1 mM D-xylose for 60 minutes, mucosa from horses and rabbits accumulated D-xylose against a concentration gradient. There was no accumulation when equine specimens were incubated with 5 mM D-xylose. By comparison, equine jejunum accumulated D-glucose against a concentration gradient when incubated in 5 mM D-glucose. In equine and rabbit jejunum, 13.3 +/- 7.0% and 36 +/- 11.0%, respectively, of accumulated D-xylose was phosphorylated when sheets were incubated in 1 mM D-xylose. Short-circuit current and potential difference were lower in equine jejunum than in rabbit jejunum, possibly because of differences in tissue thickness. None of the transmucosal electrical measurements increased after addition of D-xylose (1 mM and 5 mM) or D-glucose (5 mM). The active transport system for D-xylose has a low affinity for this sugar and becomes saturated at low intraluminal concentrations. Therefore, abnormal D-xylose absorption test results in horses are more likely caused by abnormalities in mucosal surface area and mucosal permeability than by abnormalities of nutrient carbohydrate absorption.

Animals↗
PubMed1993

Kinetic analysis of D-xylose distribution after intravenous administration to mares.

Multicompartmental analysis was applied to study the kinetics of D-xylose distribution after IV administration to healthy mares deprived of food for 12 and 96 hours. Urinary excretion of D-xylose was measured over a 15-hour period after administration. The plasma D-xylose concentrations in this study were in the range found after oral tolerance testing. The disposition of D-xylose was described by a two-compartment model with linear kinetic characteristics. Total volume of distribution decreased significantly (P < 0.025) from 0.270 L/kg of body weight after the 12-hour period of food deprivation to 0.235 L/kg after the 96-hour period. Fractional rate of transfer between the central and peripheral compartments did not change after 96 hours without food. Approximately a third of the D-xylose administered was recovered in the urine. Difference in urinary elimination between the 12- and 96-hour periods was not significant. Nonrenal elimination rate was determined to be twice the renal elimination rate. The results indicated that formal kinetic analysis can provide useful information about D-xylose distribution in horses. The decreased D-xylose space found after a 96-hour period of food deprivation would tend to increase the plasma D-xylose concentration, and this may help in the interpretation of the D-xylose absorption test applied to anorectic horses.

Animals↗
PubMed1993

Changes in fluid composition on the serosal surface of jejunum and small colon subjected to venous strangulation obstruction in ponies.

In 6 anesthetized ponies, 3 segments of jejunum and 3 segments of small colon were isolated from the peritoneal cavity in plastic bags filled with Hanks' balanced salt solution. One jejunal and 1 small colon segment were subjected to venous strangulation obstruction for 3 hours (VSO-3), venous strangulation obstruction for 6 hours (VSO-6), or a 6-hour sham procedure to control for changes induced by isolation in a plastic bag. Additional segments of jejunum and colon that were not placed in bags served as controls for histologic examination and collagenase measurements. Samples of fluid surrounding the intestine were obtained for chemical analyses, nucleated cell count, aerobic and anaerobic bacteriologic culture, and measurement of collagenase activity. Full-thickness tissue samples were obtained for histologic examination and measurement of collagenase content. Bacteria did not cross the intestinal wall after 3 and 6 hours of VSO, despite severe mucosal lesions in these segments. At 6 hours, PO2 was significantly less and PCO2 was significantly (P < 0.05) greater in the fluid surrounding the VSO-6 jejunal segments, compared with the sham jejunal segments. The pH was significantly (P < 0.05) less in fluid surrounding VSO-6 small colon segments, compared with the sham colon segments at 6 hours. For jejunum and small colon, phosphate and lactate concentrations were significantly (P < 0.05) greater in VSO-6 fluid than in the corresponding sham fluids at 6 hours. Fibrin formed around all VSO segments, although fibrinogen was not detected in the surrounding fluid, indicating possible rapid conversion of fibrinogen to fibrin.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Loop colostomy for management of rectal tears and small-colon injuries in horses: 10 cases (1976-1989).

Loop colostomy was performed in 10 horses as treatment for grade-III rectal tears (n = 6 horses), small-colon infarction (n = 2 horses), perirectal abscess and stenosis (n = 1 horse), and small-colon stricture (n = 1 horse). In 7 horses, the colostomy was constructed through a single incision low in the left flank, with closure of the incision around the stoma (single-incision technique). In 3 horses, 2 of which had colostomy performed as a standing procedure, the selected segment of small colon was placed from a flank incision into a separate, small incision low in the left flank (double-incision technique). Five horses underwent colostomy reversal (at 18 to 63 days) and 2 of these horses, both with grade-III rectal tears, recovered completely. Of 8 horses that did not survive, 6 died from the primary disease or associated complications. Technical problems associated with colostomy accounted for death of 2 horses. One horse had gastric rupture attributable to suture occlusion of the small intestine after colostomy reversal, and another horse had complications of incisional infection after repair of a peristomal hernia. Small-colon prolapse through the stoma necessitated premature reversal of the colostomy in a horse that was euthanatized because of worsening laminitis. Minor complications of the colostomy procedure were partial stomal dehiscence (n = 4 horses), partial dehiscence of the flank wound after colostomy reversal (n = 2 horses), and small ventral midline hernia after colostomy reversal (n = 1 horse). Loop colostomy may be of benefit to horses with rectal tears, provided it is done soon after the tear occurs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Does neck stage influence local control in squamous cell carcinomas of the head and neck?

Recently, reports have suggested that the probability of local control of head and neck cancers treated with radiotherapy alone is inversely related to the extent of neck node disease at presentation. This has led some to conclude that primary lesions in patients with neck node metastases should be treated more aggressively than lesions of the same T stage in patients presenting with a clinically negative neck. We reviewed the records of 607 patients with squamous cell carcinoma of the head and neck to determine the relationship between the extent of neck node disease at diagnosis and the probability of tumor control at the primary site. All patients were treated with continuous-course irradiation alone to the primary site and have a minimum follow-up of 2 years. Mucosal sites analyzed included the oropharynx (soft palate, tonsillar region, base of tongue), hypopharynx (pharyngeal wall, pyriform sinus), and supraglottic larynx. Patients with simultaneous primary lesions were excluded from the analysis. Parameters tested included T stage, N stage, and fractionation (once daily or twice daily). For statistical analyses, N stage was grouped as N0, N1, N2A-N3A, and N2B-N3B. Local control was analyzed using a multivariate analysis, the forward stepwise long-rank test of association of covariates. Multivariate analyses revealed that the following parameters significantly influenced local control: oropharynx, T stage only (p = .0010); hypopharynx, T stage (p = .001) and twice-daily fractionation (p = .0031); and supraglottic larynx, T stage only (p = .0002). No significant correlation was found between neck stage and primary tumor control on univariate or multivariate analyses. Our data do not support the conclusion that primary lesions are controlled less often in patients with clinically positive neck nodes.

Carcinoma, Squamous Cell↗
PubMed1992

Comparison of the effects of intragastric infusions of equal volumes of water, dioctyl sodium sulfosuccinate, and magnesium sulfate on fecal composition and output in clinically normal horses.

A Latin square design was used to compare the effects of laxatives and a corresponding volume of water on gastrointestinal tract function in 4 healthy horses. Horses were intragastrically infused with each of the following: dioctyl sodium sulfosuccinate (DSS; 50 mg/kg of body weight); magnesium sulfate (0.5 g/kg--low dosage); magnesium sulfate (1.0 g/kg--high dosage); and an equal volume of water (6 L) given as a control infusion. From 5 to 33 hours after the high dosage of magnesium sulfate, feces were slightly softer than usual in all horses. In 1 horse, DSS caused mild colic, hyperpnea, and diarrhea from 0.3 to 3 hours after administration. After all laxative treatments and the control infusion, fecal output, fecal water, number of defecations, and fecal water percentage were greater during the first 6 and 12 hours, compared with each subsequent 6-hour period (P less than 0.05). The high dosage of magnesium sulfate had greater effect on fecal output and fecal water than did the low dosage and control infusion (P less than 0.05). However, this effect preceded arrival of the liquid transit marker, polyethylene glycol, and magnesium at their highest concentrations in feces by 12 to 18 hours. Compared with the control infusion, none of the laxative treatments affected excretion of polyethylene glycol and plastic particulate markers, nor did they increase water consumption. It was concluded that the response to intragastric infusions may involve reflex mechanisms in the gastrointestinal tract and that these responses could be used for treatment of colon impactions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗