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Biomedical subjects

R S Pleasant

Publications and source records attributed to R S Pleasant.

18 recordsLinked to original sources
PubMed2006

Estimating equivalency values of microbial phytase for amino acids in growing and finishing pigs fitted with steered ileo-cecal valve cannulas.

Ten crossbred barrows (48.3 +/- 2.3 kg of initial BW) fitted with steered ileo-cecal valve cannulas were used to investigate the effects of supplemental microbial phytase on the apparent ileal digestibilities (AID) of AA, Ca, P, N, and DM, and the apparent total tract digestibilities of Ca, P, N, and DM. All diets were corn-soybean meal-based, and contained 0.44% Ca and 0.40% total P. Diets 1, 2, and 3 contained 12.0, 11.1, and 10.2% CP, respectively. Diets 4 and 5 had the same ingredient composition as diet 3, plus 250 and 500 U/kg phytase (Natuphos), respectively. Pigs were randomly allotted to 1 of 5 dietary treatments in a paired 5 x 5 Latin square with an extra period to test for carryover effects. Each 14-d period consisted of a 7-d adjustment followed by a 3-d total collection, a 12-h ileal digesta collection, a 3-d readjustment, and a second 12-h ileal digesta collection. Pigs were housed individually in metabolism pens (1.2 x 1.2 m). Water was supplied ad libitum, and feed was supplied at a level of 9% of the metabolic BW (BW(0.75)) per day in 2 equal daily feedings. As the dietary CP concentration increased, the AID of CP and all AA measured increased linearly (P < 0.05) with the exception of proline. In addition, the apparent total tract digestibilities (grams per day) and retention of N (grams per day) increased linearly (P < 0.01) with increasing CP levels. Supplementing diets with phytase increased the AID of Ca (P < 0.01), P (P < 0.001), CP (P = 0.07), and the AA (P < 0.10) Gly, Ala, Val, Ile, Thr, TSAA, Asp, Glu, Phe, Lys, and Arg. Protein and phytase response equations were generated for those AA affected (P < 0.10) by both CP level and phytase supplementation. Based on these equations, 500 U/kg of phytase can replace 0.52 percentage units of the dietary CP, which includes a 0.03 percentage unit improvement in Lys AID. The results of this study show that supplementing pig diets with microbial phytase improves CP and AA digestibilities in addition to Ca and P digestibilities.

6-Phytase↗
PubMed2005

Technical Note: Improved technique for fitting pigs with steered ileocecal valve cannulas.

Collection of ileal digesta to evaluate AA digestibilities has become increasingly important in swine nutrition research. Steered ileocecal valve cannulation of pigs permits total collection of ileal digesta, while still allowing normal digesta flow during noncollection periods. This technique was modified and used with 64 crossbred barrows in five trials. Our procedural changes included preoperative i.v. administration of a broad-spectrum antibiotic and nonsteroidal antiinflammatory drug, sharp incision through the muscle layers of the laparotomy wound, use of a heparinized saline lavage solution, replacement of the guide ring with a stylette, and fixing the outer cannula barrel in place with a hose clamp. The current technique involves a right flank laparotomy, parallel and distal to the last rib, with the pig under general anesthesia. A stainless-steel ring (inner ring = 2.0 mm thick, 35.0 mm i.d.) is introduced into the ileal lumen through an enterotomy proximal to the origin of the ileocecal fold. A nylon string attached to this ring is threaded through the ileum and ileocecal valve into the cecum using a silastic stylette, which encases the string. A second stainless-steel ring (outer ring = 2.0 mm thick, 34 mm o.d.) is fixed in place around the ileum, distal to the inner ring and just proximal to the ileocecal valve. A polyurethane cannula barrel (barrel = 100 mm long, 26 mm i.d., 32 mm o.d.; flange = 70 mm o.d.) is introduced into the cecal lumen via an enterotomy through the lateral cecal band and secured in place with two purse-string sutures. The cannula is exteriorized through an incision caudal and proximal to the intial laparotomy site, where it is plugged using a cylindrical stopper (26 mm o.d., 55 mm long) and held in place by a second cannula barrel (barrel = 43 mm length, 33 mm i.d., 41 mm o.d.; flange = 80 mm o.d.). Procedural changes decreased postsurgical complications, as evidenced by decreased seepage around the cannula and fewer and less severe adhesions noted at necropsy. Based on five trials, this technique is a reliable means of collecting ileal digesta for nutrient analyses.

Animals↗
PubMed2001

Failure of holmium:yttrium-aluminum-garnet laser lithotripsy in two horses with calculi in the urinary bladder.

Holmium:yttrium-aluminum-garnet (Ho:YAG) laser lithotripsy was attempted in a mare and a gelding with calculi in the urinary bladder. The procedure was unsuccessful in producing adequate fragmentation of the calculi. In the gelding, pulsed dye laser lithotripsy was subsequently used to fragment the urolith. Manual removal of the urolith via the urethra was performed in the mare.

Animals↗
PubMed1998

Pulsed dye laser lithotripsy for treatment of urolithiasis in two geldings.

Transendoscopic pulsed dye laser lithotripsy was effective in the treatment of calcium carbonate urothlithiasis in 2 adult geldings. Perineal urethrotomy provided convenient access for standing transendoscopic lithotripsy and evacuation of a large cystic calculus in one gelding. In the second horse, an obstructive urethral calculus was fragmented and removed by a transurethroscopic approach. Pulsed dye laser lithotriptor is effective in fragmentation of the most common form (calcium carbonate) of uroliths in horses and may be performed in standing horses with reduced surgical invasiveness and trauma to the urinary tract, compared with conventional approaches. The principle disadvantages include cost of the procedure, which is comparable to laparocystotomy, and the time delay required to make arrangements for use of the pulsed dye laser lithotriptor.

Animals↗
PubMed1998

Deconditioning reduces mineral content of the third metacarpal bone in horses.

Diet and exercise are two management factors that affect bone density and strength. We proposed that bone density and calcium status would be affected by deconditioning for 12 wk and by dietary Ca concentration. Eleven highly conditioned Arabian horses were taken out of training and placed in stalls for 12 wk. Horses were walked on a mechanical walker in two 30-min sessions, 7 d/wk. Diets were designated CC (.36% Ca) and HC (.62% Ca). Data were collected every 21 d. Serum or plasma were analyzed for total and ionized Ca, parathyroid hormone, osteocalcin, hydroxyproline, electrolytes, and blood gases. Bone mineral content (BMC) of the left third metacarpal bone was estimated by radiographic photometry using an aluminum step wedge, which was exposed in each radiograph, as a reference standard for an image analysis system. During deconditioning, BMC decreased by approximately 1.1 g/2 cm, or .45% per week. This decrease was unaffected by dietary Ca. Serum Ca concentration increased with deconditioning. The results suggest that dietary Ca at twice the currently recommended level did not prevent the loss of BMC in response to deconditioning. Loss of BMC during 12 wk of stall confinement may weaken bones, increasing the risk of skeletal injuries when training is resumed.

Absorptiometry, Photon↗
PubMed1998

Evaluation of mild lameness in horses trotting on a treadmill by clinicians and interns or residents and correlation of their assessments with kinematic gait analysis.

OBJECTIVE: To estimate sensitivity and accuracy of subjective evaluation of mild lameness in horses during treadmill locomotion and to correlate subjective evaluation with kinematic analysis. ANIMALS: 19 lame and 5 clinically normal horses. PROCEDURE: Lameness was evaluated by subjective score and kinematic analysis before and after palmar digital nerve block (PDNB). Evaluations were made by 6 clinicians and 7 interns or residents. Within- and between-observer agreement analyses (kappa values) were calculated and compared, using a Student's t-test. Pearson's product-moment correlation coefficients were calculated between clinician's change in score and the change in kinematic variables after PDNB. RESULTS: Within-observer agreement was within the range expected for conditions of moderate diagnostic difficulty. Within-observer agreement was higher for clinicians than for interns or residents. Between-observer agreement was acceptable for scores within 1 value of each other. Between-observer agreement of change in lameness score after PDNB was poor. When kinematic variables were ranked with each clinician's subjective change in score, only 2 were among the top 3 for the majority of clinicians. Asymmetry of vertical head movement between contralateral forelimb stance phases and the point of maximum hoof height during swing decreased as lameness subjectively improved. CONCLUSION: Mild lameness may be difficult to evaluate during treadmill locomotion. Although clinicians were more repeatable in their subjective evaluation of lameness than interns or residents, they were not more reliable at detecting the true state of lameness. CLINICAL RELEVANCE: Lack of agreement between clinician scoring of mild lameness emphasizes the need to use more objective measures for quantifying lameness.

Animals↗
PubMed1995

Use of a type II external skeletal fixator for repair of delayed union in three calves with forelimb fractures.

Three calves, 3 to 6 months old, were admitted for evaluation and treatment of fractures of the forelimb that had resulted from use of forced extraction at birth. Each of these calves had clinical and radiographic evidence of delayed union of a fractured metacarpus. All calves were treated, using a type II external skeletal fixator consisting of 0.25-inch-diameter transcortical pins and acrylic connecting bars. Two calves required open reduction of the fracture to obtain anatomic alignment of the limb. On the basis of the 3 calves described here, it would appear that type II external skeletal fixators may be adequate for treatment of selected calves with delayed union of a fracture.

Animals↗
PubMed1993

Intraosseous pressure and pathologic changes in horses with navicular disease.

Navicular bone intraosseous pressure, gross pathologic, histologic, and histochemical data were collected from 8 horses with navicular disease and 4 control horses. Simultaneous navicular bone intraosseous, medial palmar arterial, and saphenous venous pressures were measured for the left and right forelimbs of each horse under general anesthesia. Gross pathologic evaluation included grading of changes on the flexor surface of the navicular bone. Safranin-O-fast green-stained sections were used for histologic-histochemical grading of the hyaline articular and fibrocartilage surfaces of the navicular bones. Hematoxylin and eosin-stained sections were used for morphologic evaluation of the marrow spaces of navicular bones. Mean navicular bone intraosseous pressure for horses with navicular disease was significantly (P < 0.001) higher than that for controls. Differences in medical palmar arterial or saphenous venous pressures were not significant between groups. The median flexor surface gross pathologic and histologic-histochemical fibrocartilage scores for horses with navicular disease were significantly (P < 0.001) more severe than those for control horses. The histologic-histochemical hyaline cartilage scores for control horses and those for horses with navicular disease were not significantly different. Fibrosis of the marrow spaces beneath the flexor cortex of horses with navicular disease was more pronounced than that of control horses.

Animals↗
PubMed1992

Stress reactions and stress fractures of the proximal palmar aspect of the third metacarpal bone in horses: 58 cases (1980-1990).

The case records, radiographs, and nuclear bone scans of 58 horses with stress reactions or stress fractures of the proximal palmar aspect of the third metacarpal bone (MC3) were reviewed. There were 47 Standardbreds, 4 Quarter Horses, 3 Thoroughbreds, 2 Arabians, 1 Oldenburg, and 1 Pony of America. Fifty-six of the horses were racehorses or performance horses. The mean and median ages of affected horses were 4 and 3 years, respectively. Lameness ranged from mild to severe. Physical findings were usually subtle and included signs of pain on deep palpation of the proximal palmar aspect of MC3 and slight effusion of the middle carpal joint in some cases. Lameness was commonly improved by high palmar and palmar metacarpal nerve blocks or anesthesia of the middle carpal joint. Fifty-three horses had higher than normal radiopharmaceutical uptake in the proximal palmar aspect of MC3 in the left or right limb. The other 5 horses had higher than normal radiopharmaceutical uptake bilaterally. Fifty-six of the 63 limbs with abnormal bone scans also had abnormal radiographs. Treatment consisted of a variable period of rest (1 to 6 months). Healing was best assessed by follow-up bone scans. Of the 45 horses for which follow-up information was adequate, 29 (64%) returned to their previous level of performance.

Animals↗
PubMedDate not supplied

Evaluation of a technique to occlude the internal carotid artery of horses.

OBJECTIVE: To evaluate an occlusion technique for the internal carotid artery of horses using an intravascular, detachable, self-sealing, latex balloon distally and ligatures proximally. STUDY DESIGN: Experimental study. ANIMALS: Six healthy adult horses. METHODS: In each horse, the left internal carotid artery was occluded by placement of an intravascular, detachable, self-sealing, latex balloon distally and two ligatures proximally. Radiographs were taken on days 2, 5, 10, and 30 after surgery to evaluate balloon inflation and position. Endoscopic examination of the left guttural pouch was performed 10 days after surgery to evaluate the integrity of the internal carotid artery and surrounding tissues. At 30 days, the left and right, common, internal, and external carotid arteries were examined grossly and then processed for histologic evaluation. RESULTS: Immediate and long-term occlusion of the left internal carotid artery was achieved in all horses. The surgical procedure was technically straightforward and no intraoperative or postoperative complications were encountered. The balloons remained inflated and in their original position throughout the study. Maturing to mature, organized thrombi were present in the left internal carotid artery in all horses at 30 days. The cerebral arterial circle and common carotid artery were patent at their junctions with the internal carotid artery in all horses. CONCLUSIONS: Use of an intravascular, detachable, self-sealing, latex balloon distally and ligatures proximally is an effective technique for occluding the internal carotid artery of horses. CLINICAL RELEVANCE: This technique may be useful for prevention of fatal hemorrhage in horses with lesions of the internal carotid artery.

Animals↗
PubMedDate not supplied

Arthroscopic anatomy of the equine temporomandibular joint.

OBJECTIVE: To develop an arthroscopic approach to, and describe the arthroscopic anatomy of, the equine temporomandibular joint (TMJ). STUDY DESIGN: Cadaveric study, after which the technique was tested in horses. ANIMALS OR SAMPLE POPULATION: Ten cadaveric equine heads and 5 normal horses (age, 5-13 years; weight, 425-545 kg). METHODS: Specimens or horses were positioned in right lateral recumbency. After fluid distention of the TMJ, arthroscopic portals were made in the dorsal compartment over the most prominent portion of the joint outpouching (caudodorsal approach) and in rostral and intermediate locations. The joint was explored and photographed. Positional changes in the mandible were made to determine if observation of the joint could be improved. Instrument portals were created to assess the feasibility of surgical arthroscopy. Cadaveric heads were dissected to assess iatrogenic damage, whereas experimental horses were observed for postoperative complications for 30 days. RESULTS: A caudodorsal arthroscopic approach provided the best evaluation of the dorsal compartment of the TMJ. The approach allowed observation of the rostral and caudal synovial pouches and the lateral aspect of the joint including the articular disc. Examination of the medial aspect of the joint was limited to the most rostral and caudal aspects. Access to the lateral aspect of the ventral compartment of the TMJ was precluded by the position of the transverse facial artery and vein. In specimens, iatrogenic damage was minimal and limited to the articular fibrocartilage, articular disc, and penetration of the parotid salivary gland. If the latter also occurred in horses, no adverse effects were noted. In horses, mild fluid extravasation occurred and resolved within 1 day. All horses ate normally after surgery but had periarticular swelling and mild pain upon palpation of the TMJ for 2 days. CONCLUSIONS: A caudodorsal arthroscopic approach to the TMJ allowed adequate observation of the lateral aspect of the dorsal compartment of the joint. Access to the ventral compartment was precluded by the location of the transverse facial artery and vein. CLINICAL RELEVANCE: Conditions affecting the lateral and caudal aspects of the dorsal compartment of the TMJ should be visible by arthroscopy.

Animals↗
PubMedDate not supplied

Efficacy of an epidural combination of morphine and detomidine in alleviating experimentally induced hindlimb lameness in horses.

Amphotericin B-induced synovitis of the left tarsocrural joint was used to create a grade 3 of 4 lameness in 11 horses. Caudal epidural catheters were placed and advanced to the lumbosacral region. Baseline heart and respiratory rates were recorded and horses were videotaped at a walk and trot. Morphine sulphate (0.2 mg/kg) and detomidine hydrochloride (30 micrograms/kg) were administered to treated horses (n = 8) through the epidural catheter; an equivalent volume of physiologic saline solution was administered to control horses (n = 3) through the catheter. At hourly intervals after epidural injection for a total of 6 hours, heart and respiratory rates were recorded, and horses were videotaped walking and trotting. At the end of the observation period, video recordings were scrambled onto a master videotape. Lamenesses were scored by three investigators unaware of group assignment or treatment time. Lameness scores, heart rates, and respiratory rates were compared between groups using repeated measures analysis of variance. There was a significant decrease in lameness score after treatment with epidural morphine and detomidine (P = .0003); average lameness scores of treated horses were less than grade 1 at each hourly observation for 6 hours after drug administration. Early in the observation period, heart rates significantly increased in control horses and decreased in treated horses (P = .03). A similar trend occurred for respiratory rates (P = .07). Results of this study demonstrate that epidural administration of a combination of morphine and detomidine is capable of providing profound hindlimb analgesia in horses.

Adrenergic alpha-Agonists↗
PubMedDate not supplied

Intra-articular anesthesia of the distal interphalangeal joint alleviates lameness associated with the navicular bursa in horses.

OBJECTIVE: To determine if intra-articular anesthesia of the distal interphalangeal joint could alleviate lameness associated with the navicular bursa in horses. STUDY DESIGN: Experimental investigation. ANIMALS: Six clinically normal horses. METHODS: Lameness was induced in each horse by injecting either the left or right front navicular bursa with 5 mg of amphotericin-B. Forty-eight hours later each horse was videotaped walking and trotting before, and 5, 30, and 60 minutes after injecting the distal interphalangeal joint of the treated limb with 5 mL of 2% mepivacaine hydrochloride. All video recordings were then rerecorded onto master tapes in a random sequence. Four clinicians, unaware of the animal identity related to observation time or limb treated, independently viewed these tapes and graded the lamenesses. RESULTS: There was a significant reduction in lameness 5 and 30 minutes after anesthetic was injected into the distal interphalangeal joint. Lameness scores 60 minutes after anesthetic administration were not significantly different than baseline values. Gross pathological examination confirmed marked inflammation of the treated navicular bursae and normal appearance of the distal interphalangeal joints. CONCLUSIONS: Intra-articular anesthesia of the distal interphalangeal joint can alleviate lameness associated with the navicular bursa. CLINICAL RELEVANCE: Intra-articular anesthesia of the distal interphalangeal joint is not specific only for lameness originating in the distal interphalangeal joint.

Amphotericin B↗
PubMedDate not supplied

Systemic and local effects associated with long-term epidural catheterization and morphine-detomidine administration in horses.

OBJECTIVE: The purpose of this study was to determine the systemic and local effects associated with long-term epidural catheterization and epidural morphine-detomidine administration in horses. STUDY DESIGN: Development of systemic or local effects was assessed by placing caudal epidural catheters in study horses and administering injections through the catheters every 12 hours for 14 days. ANIMALS: Ten horses with epidural catheters that received daily injections; six uncatheterized horses presented for euthanasia. METHODS: Horses received either 0.2 mg/kg morphine sulfate and 30 micrograms/kg detomidine hydrochloride or an equivalent volume of physiologic saline solution through epidural catheters. Systemic effects were compared between control and treatment horses by measuring physical parameters and hay and water consumption, as well as by evaluating major organs after euthanasia. Local effects were studied by examining cerebrospinal fluid and by grading representative samples of the spinal cord and surrounding tissues histologically for inflammation and fibrosis. Local effects were compared between control and treatment horses, as well as between catheterized (control plus treatment) horses and uncatheterized horses. RESULTS: No significant difference was identified in daily variables or hay and water consumption between control and treatment horses. No growth was obtained from cerebrospinal fluid cultures. No significant difference in cerebrospinal fluid values or spinal tissue inflammation or fibrosis grades was shown between control and treatment horses. However, when compared with uncatheterized horses, cerebrospinal fluid red blood cell values were marginally higher and protein concentrations were significantly higher in the catheterized group. Lumbosacral and sacral spinal tissue segment inflammation grades, and sacral segment fibrosis grades were significantly higher in catheterized horses. CONCLUSIONS: Long-term epidural administration of a morphine-detomidine combination is not associated with apparent adverse systemic effects in horses. Localized inflammation and fibrosis seem to be catheter-related. CLINICAL RELEVANCE: Potential systemic and local effects are important considerations with long-term administration of a morphine-detomidine combination through indwelling epidural catheters for alleviation of chronic musculoskeletal pain in horses.

Analgesics↗
PubMedDate not supplied

Urinary bladder marsupialization for treatment of obstructive urolithiasis in male goats.

OBJECTIVES: To describe a surgical procedure for urinary bladder marsupialization and to report the results obtained from its use in the treatment of obstructive urolithiasis in male goats. STUDY DESIGN: Retrospective evaluation. ANIMALS OR SAMPLE POPULATION: Male goats with obstructive urolithiasis. METHODS: Medical records of male goats that had urinary bladder marsupialization for the treatment of obstructive urolithiasis were reviewed. Data retrieved from the medical records included signalment, postoperative treatment, duration of hospitalization, and short-term and long-term complications. Median values for measured variables were calculated. RESULTS: A total of 18 of 19 goats survived. Urinary flow was re-established in all 19 goats at the conclusion of surgery. Short-term postoperative complications (bladder mucosal prolapse and death) were observed in 2 goats. Long-term postoperative complications (cystitis and fibrotic stomal closure) occurred in 2 animals. Median duration of hospitalization was 4 days. At the time of follow-up, mild urine scald was reported for all goats. Clinical signs of upper urinary tract disease or obstruction were not reported. A total of 15 of 17 owners were satisfied with the procedure. CONCLUSIONS: Urinary bladder marsupialization provided long-term resolution of urinary outflow obstruction in all goats with acceptable morbidity. CLINICAL RELEVANCE: Urinary bladder marsupialization is a procedure that provides a good prognosis for long-term resolution of obstructive urolithiasis in male goats.

Animals↗