Two distinct monoclonal antibodies (MAB) were prepared for testing with kidney, spleen, and retrobular tissue imprints made from chinook salmon (Oncorhynchus tshawytscha) affected with plasmacytoid leukemia (PL). Hybridomas were prepared from mice immunized with whole and lysed cells purified from renal or retrobular PL-positive tissues, which had been obtained from naturally and experimentally infected fish from British Columbia, Canada. The MAB reacted with at least 4 morphologically different cell types; fluorescence was associated with the plasma membrane and cytoplasm. The MAB also reacted with kidney imprints made from chinook salmon affected with a PL-like lymphoproliferative disease in California, indicating that these 2 diseases might be caused by a similar agent. The MAB did not react with any of the kidney or spleen imprints made from wild chinook salmon collected from a river in Ontario, Canada.

The density of the cricoid cartilage from 29 equine larynges collected from an abattoir was determined by dual photon absorptiometry (DPA). Densities of the right and left cricoid cartilages were highly correlated. No correlation was found between age of the horse and the density of the cricoid cartilage.

Two experiments were performed to study the relationship between leukotriene B4 (LTB4) synthesis and placental separation and uterine involution in the cow. In experiment I, the concentration and synthesis of LTB4 by caruncular tissue was lower in cows with retained fetal membranes (RFM cows, n = 11) than in cows that expelled the fetal membranes normally (NFM cows, n = 19). The presence of bacterial cell wall, especially of alpha-hemolytic streptococci and coagulase positive staphylococci enhanced LTB4 synthesis by allantochorion only in NFM cows. In the RFM group, Escherichia coli lipopolysaccharide decreased allantochorionic LTB4 synthesis. With caruncle, only epidermal growth factor increased LTB4 production in NFM cows. In experiment II, the caruncular and endometrial secretion of LTB4 was lower in cows with subuterine involution (SUI cows, n = 5) or cows with SUI and RFM (SUI+RFM cows, n = 4) than in cows with normal uterine involution (NUI cows, n = 8). This decrease was especially noticeable in the previously gravid horn. In the three uterine involution groups, there were no differences in LTB4 synthesis by caruncular tissue taken from the previously gravid horn. However, progesterone and a bacterial suspension of E. coli reduced the synthesis of LTB4. Estradiol had no effect on LTB4 synthesis at the end of the postpartum period. These results suggest that LTB4 may play an important role in both placental separation and uterine involution in cattle and LTB4 synthesis may be modulated by endocrine and bacterial factors.

We determined whether administration of cisplatin in hypertonic saline solution would prevent significant decrease in renal function, as measured by exogenous creatinine clearance, in healthy dogs. A single dose of cisplatin (70 mg/m2 of body surface) was mixed in 3% saline solution and was infused IV (6.5 ml/kg of body weight) over a 20-minute period to 6 healthy dogs. Exogenous creatinine clearance was determined prior to treatment of dogs with cisplatin and again on days 3 and 21 after administration of cisplatin. All 6 dogs vomited at least once within 12 hours of treatment with cisplatin; however, clinically important changes in appetite, body weight, or hydration status were not apparent during the 21-day study. Although mean values for exogenous creatinine clearance decreased from baseline on days 3 and 21, changes were not significantly different. Renal histologic lesions included mild, chronic, lymphoplasmacytic interstitial nephritis in 5 dogs, and presumably, were unrelated to treatment with cisplatin. Mild renal tubular atrophy (n = 2) and tubular necrosis (n = 1) may have developed secondary to treatment with cisplatin. Results of this study indicated that administration of a single dose of cisplatin in 3% saline solution to healthy dogs was not associated with significant decrease in glomerular filtration rate. This is a convenient protocol for administering cisplatin; however, additional study is required before it can be recommended for clinical patients, especially those with preexisting renal disease or those receiving multiple doses of cisplatin.

Eight dogs (body weight, 12.5 to 21.5 kg) were assigned at random to each of 3 treatment groups (IS, IX, IM) that were not given glycopyrrolate and to each of 3 groups that were given glycopyrrolate (IGS, IGX, IGM). Dogs, were anesthetized with isoflurane (1.95% end-tidal concentration), and ventilation was controlled (PCO2, 35 to 40 mm of Hg end-tidal concentration). Glycopyrrolate was administered IV and IM at a dosage of 11 micrograms/kg of body weight, each. Saline solution, xylazine (1.1 mg/kg, IM), or medetomidine (15 micrograms/kg, IM) was administered 10 minutes after baseline ADE determination. Redetermination of the ADE at the same infusion rate was started 10 minutes after drug administration. Arrhythmogenic dose was determined by constant infusion of epinephrine at rates of 1.0, 2.5, and 5.0 micrograms/kg/min. The ADE was defined as the total dose of epinephrine that induced at least 4 ectopic ventricular depolarizations within 15 seconds during a 3-minute infusion, or within 1 minute after the end of the infusion. Total dose was calculated as the product of infusion rate and time to arrhythmia. Statistical analysis of the differences between baseline and treatment ADE values was performed by use of one-way ANOVA. Mean +/- SEM baseline ADE values for groups IS, IX, and IM were 1.55 +/- 0.23, 1.61 +/- 0.28, and 1.95 +/- 0.65 micrograms/kg, respectively. Differences for groups IS, IX, and IM were -0.12 +/- 0.05, -0.31 +/- 0.40, and -0.17 +/- 0.26, respectively. Differences for groups IGS, IGX, and IGM could not be calculated because arrhythmias satisfying the ADE criteria were not observed at the maximum infusion rate of 5.0 micrograms/kg/min. Differences among groups IS, IX, and IM were not significant. We conclude that in isoflurane-anesthetized dogs: preanesthetic dosages of xylazine (1.1 mg/kg, IM) or medetomidine (15 micrograms/kg, IM) do not enhance arrhythmogenicity, and at these dosages, there is no difference in the arrhythmogenic potential of either alpha 2-adrenergic receptor agonist.

To evaluate the effect of ketoprofen on fecal output during secretory diarrhea, 16 calves were given approximately 200 micrograms of heat-stable Escherichia coli enterotoxin by suckling on 2 occasions. On one day, treatment was not administered. On the other day, either 3 mg of ketoprofen/kg of body weight (n = 8) or 6 mg of ketoprofen/kg (n = 8) was administered 1 hour before and 3 hours after administration of enterotoxin. Fecal output was no different after 8 or 24 hours from calves given 3 mg/kg, but fecal output was less at 8 hours and 24 hours for calves given 6 mg/kg (P = 0.0588), compared with the control day.

Motion of 6 clinically sound horses trotting at a speed of 4 m/s on a treadmill was captured by video cameras before and 9, 16, and 23 days after amphotericin-induced lameness to determine the quantitative variables of three-dimensional computer-assisted image analysis that objectively describe carpal lameness. Amphotericin-B was used to induce lameness, and phenylbutazone (2.2 mg/kg of body weight, PO, once) and butorphanol tartrate (0.1 mg/kg IM, q 6 h, to effect) were used to control discomfort. Four 60-Hz cameras were symmetrically placed around the treadmill to capture 6 seconds of images from retroreflective spheres taped to the trotting horses. Images were transferred to a video-based digitizer and a computer work station, where 4 files of two-dimensional data were reduced to 1 file of three-dimensional data. The effect of lameness on motion analyzed was assessed by use of two-way ANOVA. Differences between means were assessed, using the Student-Newman-Keul's test (P less than or equal to 0.05). Head and withers excursions, (dorsal vertical displacement of head and withers targets, respectively) during the sound forelimb support phase were increased significantly during all lameness measurement periods. Head excursion, but not withers excursion, during the lame forelimb support phase, was decreased significantly during all lameness measurement periods. Computer determinations of stride length swing phase, stance phase, forelimb abduction, and carpal and fetlock ranges of motion did not consistently characterize the lameness. It was concluded that three-dimensional computer-assisted image analysis could be used for objective lameness evaluation in horses and that head and withers excursions were the most consistent variables for assessing equine carpal lameness.

Renal clearance procedures were performed on adult mixed-breed dogs with a wide range of renal function. Endogenous creatinine clearance was computed after analyzing plasma and urine for creatinine by use of 2 methods, PAP and kinetic Jaffe. For 20-minute clearance procedures, [14C]inulin clearance was measured simultaneously with endogenous creatinine clearance. For 111 twenty-minute clearance procedures performed on 24 dogs, [14C]inulin clearance was highly correlated with creatinine clearance for both methods of creatinine analysis (R2 = 0.979 for [14C]inulin-PAP; R2 = 0.943 for [14C]inulin-Jaffe). The absolute values for PAP and [14C]inulin clearance were nearly the same (PAP-to-[14C]inulin clearance ratio = 1.03 +/- 0.08), but those for Jaffe clearance were substantially less than those for [14C] inulin clearance Jaffe-to-[14C]inulin clearance ratio = 0.88 +/- 0.10). The Jaffe-to-[14C] inulin clearance ratio was inversely correlated with degree of renal function (R2 = 0.464), whereas the PAP-to-[14C]inulin clearance ratio was not correlated with degree of renal function (R2 = 0.060). Thus, Jaffe-determined creatinine clearance varied, in relation to [14C] inulin clearance, depending on degree of renal function. In 4 clinically normal dogs, 20-minute and 24-hour sample collections analyzed by use of the PAP method gave clearance values significantly greater, for both periods, than did Jaffe analyses. The PAP-determined creatinine clearance values were less than, but not significantly different from 20-minute exogenous creatinine clearance values determined 10 days after 24-hour collections. For 20-minute and 24-hour collections, the difference in clearance values between the PAP and Jaffe methods was attributable mostly to lower plasma creatinine values for the PAP method (mean +/- SEM, plasma PAP-to-Jaffe ratio = 0.798 +/- 0.053). However, urine creatinine values also were less by use of the PAP method (urine PAP-to-Jaffe ratio = 0.943 +/- 0.103). We conclude that PAP-determined creatinine clearance reliably measured glomerular filtration rate during 20-minute collections, and probably during 24-hour collections as well. By contrast, Jaffe-determined creatinine clearance underestimated glomerular filtration rate by a variable amount.

Withdrawal periods required when doses of 24,000 IU and 66,000 IU of procaine penicillin G/kg body weight were administered to yearling beef steers by intramuscular injection daily for five consecutive days were investigated. These dosages are in excess of product label recommendations, but are in the range of procaine penicillin G dosages that have been administered for the treatment of some feedlot bacterial diseases. The approved dose in Canada is 7,500 IU/kg body weight intramuscularly, once daily, with a withdrawal period of five days. Based on the tissue residue data from this study, the appropriate withdrawal period is ten days for the 24,000 IU/kg body weight dose and 21 days for the 66,000 IU/kg body weight dose when administered intramuscularly to yearling beef steers. In a related study, 18 yearling beef steers received 66,000 IU of procaine penicillin G/kg body weight administered by subcutaneous injection, an extra-label treatment in terms of both dose and route of administration, typical of current practice in some circumstances. Deposits of the drug were visible at subcutaneous injection sites up to ten days after injection, with more inflammation and hemorrhage observed than for intramuscular injections of the same dose. These results suggest that procaine penicillin G should not be administered subcutaneously at high doses; and therefore a withdrawal period was not established for subcutaneous injection.

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-xylose 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.