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Pharmacokinetics and synovial fluid concentrations of cephapirin in calves with suppurative arthritis
1991
Brown, M.P. | Gronwall, R.R. | Pattio, N. | Poulos, P.W. | Houston, A.E.
Six calves with suppurative arthritis were given a single IM injection of sodium cephapirin at a dosage of 10 mg/kg of body weight. Cephapirin concentrations were serially measured in serum and in normal and suppurative synovial fluid over a 24-hour period. Mean peak serum concentration was 6.33 microliter/ml at 20 minutes after injection. The highest cephapirin concentrations in normal and suppurative synovial fluid were 1.68 and 1.96 microgram/ml, respectively, 30 minutes after injection. Overall mean cephapirin concentration in normal synovial fluid for the first 4 hours (1.04 +/- 0.612 microgram/ml) was not significantly different from that in suppurative synovial fluid (0.88 +/- 0.495 microgram/ml; P > 0.05). Elimination half-life was 0.60 hours and clearance was 1,593 ml/h/kg.
Afficher plus [+] Moins [-]Location of open reading frames coding for equine herpesvirus type-1 glycoproteins with homology to gE and gI of herpes simplex virus
1991
Elton, D.M. | Bonass, W.A. | Killington, R.A. | Meredith, D.M. | Halliburton, I.W.
The DNA fragments representing the entire short unique region and part of the repeat sequences of the equine herpesvirus type-1 genome were cloned into plasmid vectors. The approximate positions of the junctions between the short unique region and the inverted repeats were then located by restriction endonuclease mapping. Two open reading frames coding for potential glycoproteins have been identified within the short unique region, using DNA sequence analysis. The predicted amino acid sequences of these open reading frames had extensive homology to the herpes simplex virus glycoproteins gE and gI and the related glycoproteins of pseudorabies virus and varicella-zoster virus.
Afficher plus [+] Moins [-]Measurement of anal and genitoanal reflexes in cats
1991
Cook, J.R. Jr | Oliver, J.E. Jr | Purinton, P.T.
Noninvasive determination of anal and genitoanal reflexes was evaluated in clinically normal cats. Thirty adult mixed-breed cats (15 sexually intact or castrated males, 15 sexually intact or spayed females) were sedated by IV administration of ketamine, acetylpromazine, and atropine. Anal reflexes were recorded from the anal sphincter muscle after ipsilateral and contralateral electrical stimulation of the perineal skin. Genitoanal reflexes were recorded from the anal sphincter muscle after electrical stimulation of the penis or clitoris. An anal sphincter response to tibial nerve stimulation was attempted. Anal reflexes from ipsilateral and contralateral stimulations and a genitoanal reflex were detected in all cats. Anal sphincter responses to tibial nerve stimulation were inconsistent (4/30) and were not included in any analyses. Anal reflexes had response latencies of 7.5 to 12.0 ms (ipsilateral stimulation) and 6.5 to 13 ms (contralateral stimulation). Genitoanal reflexes had latencies of 9.0 to 13.0 ms (males) and 6.5 to 9.0 ms (females). Anal reflex latencies were significantly (P < 0.05) longer for contralateral, opposed to ipsilateral, stimulation and were significantly (P < 0.05) longer in males than in females. Genitoanal reflex latencies were also significantly (P < 0.05) longer in males than in females, reflecting the more peripheral stimulation site in males. Anal reflex responses could be recorded in 2 feline clinic patients with such severe perineal trauma that pudendal nerve function could not be manually evaluated. A potentially favorable prognosis was given in each instance on the basis of detection of the response. One cat eventually recovered. The other was euthanatized because of other problems, and the sacral part of the spinal cord, sacral nerve roots, and pudendal nerves were found to be intact at necropsy.
Afficher plus [+] Moins [-]Axial pattern flap based on the caudal auricular artery in dogs
1991
Smith, M.M. | Payne, J.T. | Moon, M.L. | Freeman, L.E.
An axial pattern flap that was based on the sternocleidomastoideus branches of the caudal auricular artery and vein was developed. Control flaps, which included ligation and division of the caudal auricular artery and vein, were similarly developed on the contralateral aspect of the neck. Mean survival of caudal auricular artery axial pattern flaps (85.2%), compared with control flaps (63.9%), was significantly different (P < 0.05). On the basis of results of this study, an axial pattern flap based on the sternocleidomastoideus branches of the caudal auricular artery and vein may be a source of skin for reconstructive procedures of the head and neck.
Afficher plus [+] Moins [-]Analysis of selected variables in the under-agarose assay for chemotactic responses of canine neutrophils
1991
Nagahata, H. | Kociba, G.J. | Reiter, J.A. | Couto, C.G.
Chemotaxis under agarose was evaluated to establish an assay system and to characterize chemotacticresponses of canine neutrophils. A method for the measurement of canine neutrophil chemotaxis was established, with optimal responses obtained with agarose containing 10% pooled canine serum, a concentration of 5 X 10(5) cells/well, zymosan-activated serum (ZAS), or autologous serum or plasma as the chemoattractants, and a 120-minute incubation period. Canine neutrophils responded well to ZAS, heat-inactivated ZAS, autologous serum and plasma, and heat-inactivated pooled serum. Chemotactic activity was proportional to the concentration of serum used as the chemoattractant. Mean (+/- SD) random migration, chemotaxis, chemotactic index, and chemotactic differential of neutrophils from 9 healthy Greyhounds were 1.09 (+/- 0.23), 1.95 (+/- 0.38), 1.82 (+/- 0.31), and 0.86 (+/- 0.32) mm,respectively.
Afficher plus [+] Moins [-]Effect of colostrum ingestion on gamma-glutamyltransferase and alkaline phosphatase activities in neonatal pups
1991
Center, S.A. | Randolph, J.F. | ManWarren, T. | Slater, M.
Analysis of hepatic enzyme activities in serum samples from 1- to 3-day-old pups revealed alkaline phosphatase (ALP) activities that were 30 times higher and gamma-glutamyltransferase (GGT) activities that were 100 times higher than activities in clinically normal adult dogs. A study was conducted to investigate high enzyme activity in pups and to determine whether there is any association between serum enzyme activity and colostrum ingestion, passive transfer of maternal serum enzyme (in colostrum or in utero), or excessive renal or hepatic tissue enzymes. Serum enzyme activity was quantified in 15 neonatal pups before and after ingestion of colostrum and in 3 colostrum-deprived neonates fed a milk substitute. Serum samples were collected on postpartum days 0, 1, 10, 15, and 30. Enzyme activity was also quantified in serum from pregnant and lactating bitches (collected on days - 2, 0, 1, 10, 30), hepatic and renal tissue from clinically normal adult dogs and 1-day-old pups, colostrum, milk (collected on days 10 and 30), and milk replacer. Significant (P < 0.01) differences in serum GGT and ALP activities between colostrum-deprived and suckling pups did not exist before initial feeding. Significant (P < 0.001) increases in serum GGT and ALP activities developed within 24 hours in suckling pups, but not in the colostrum-deprived pups. At 10 and 30 days after birth, serum GGT and ALP activities were less than values before suckling in all pups. Enzyme activities in bitches' serum remained within the normal range for adult dogs throughout whelping and lactation. Renal GGT and ALP activities were substantially greater than hepatic enzyme activities in neonates and adults. Renal tissue from adults contained 3 times greater GGT and 2 times greater ALP activities than that from neonates. Hepatic tissue from neonates contained 5 times more GGT activity than did hepatic tissues from clinically normal adults; however, hepatic ALP activity was similar in adults and neonates. Colostrum and milk bad substantially higher enzyme activities than did bitches' serum. Activities of GGT and ALP in milk were 100 times and 10 times greater, respectively, than activities in serum through day 10. By day 30, GGT and ALP activities in milk were less than before suckling. Enzyme activity was not detected in the milk substitute. These studies reveal an association between colostrum ingestion by suckling and acute, profound increases in serum GGT and ALP in 1- to 3-day-old pups. Although this phenomenon might be useful as an indicator of colostrum ingestion, it precludes the diagnostic use of either enzyme as an indicator of hepatobiliary disease in 3-day-old pups.
Afficher plus [+] Moins [-]Comparison of genitoanal and bulbospongiosus reflexes and measurement of penile nerve conduction velocity in cats
1991
The bulbospongiosus reflex, genitoanal reflex, and nerve conduction velocity of the dorsal nerve of the penis were evaluated in cats. Seven adult sexually intact or castrated male mixed-breed cats underwent surgical isolation of the bulbospongiosus (analagous to bulbocavenosus) branch, anal branch, and distal trunk of the pudendal nerve. The bulbospongiosus and genitoanal reflexes were recorded from the bulbospongiosus and anal branches, respectively, by electrical stimulation, in turn, of the distal pudendal trunk and the penis itself. Nerve conduction velocity of the dorsal nerve of the penis was calculated by measuring response latency differences in the anal branch after stimulation of 2 sites on the extruded penis. The bulbospongiosus reflex had response latencies of 8.1 to 10.3 ms (distal trunk stimulation) and 11.0 to 13.0 ms (penile stimulation). The genitoanal reflex had latencies of 8.1 to 10.5 ms (distal trunk stimulation) and 11.2 to 13.2 ms (penile stimulation). Response amplitudes diminished at stimulus rates of 5 to 10 Hz; responses were abolished at rates of 12 to 15 Hz, suggesting that the reflexes are polysynaptic. There was no significant difference between latency values for the bulbospongiosus and genitoanal reflexes. Mean +/- SD nerve conduction velocity in the dorsal nerve of the penis was calculated to be 3.8 +/- 0.34 m/s, which was considerably slower than that found in human beings. This may represent technical difficulties in performing the test in cats, but could also indicate a difference between cats and human beings in the predominant population of cutaneous sensory fiber types of the penis.
Afficher plus [+] Moins [-]Renal clearance and fractional excretion of electrolytes over four 6-hour periods in cattle
1991
Fleming, S.A. | Hunt, E.L. | Riviere, J.E. | Anderson, K.L.
Four consecutive 6-hour urine sample collections were performed on 7 healthy adult Holstein cows fed a diet of coastal Bermuda hay with ad libitum water consumption. Urine (via indwelling urinary catheter) and venous blood samples were collected at 6, 12, 18, and 24 hours. Total 24-hour urine production for the 7 cows ranged from 4,515 to 7,130 ml/d (mean +/- SD, 5,633 +/- 946 ml/d) or 0.02 to 0.04 ml/kg of body weight/d (mean +/- SD, 0.03 +/- 0.007 ml/kg/d). Renal clearance (C) of creatinine (Cr), sodium (Na), calcium (Ca), and magnesium (Mg) varied significantly (P less than 0.05) among individuals, but did not vary significantly among the four 6-hour collection periods. Clearance of chloride (Cl) and phosphorous (P) did not vary significantly either among individuals or among the four 6-hour periods. Clearance of potassium (K) varied significantly (P less than 0.05) among individuals and among the four 6-hour periods. Creatinine clearance was significantly (P less than 0.01) correlated with CCl, CCa, CP, and CMg when all data were considered. Significant (P less than 0.05) correlations were also found between CCl, and CK, CCa, CP, and CMg; between CCa and CP and CMg; and between CP and CMg. Fractional excretion (FE) of Na, K, Cl, Ca, P, and Mg did not vary significantly among the four 6-hour periods. Fractional excretion of Na, Ca, and Mg (P less than 0.01) and K and P (P less than 0.05) varied significantly within individuals among the 6-hour periods. Mean FE values, calculated by averaging values for each of the 4 collection periods for all 7 cows, ranged from 0.05 to 0.78% for FENa; 129.33 to 670.40% for FEK; 1.23 to 6.23% for FECl; 0.17 to 4.44% for FECa; 0.36 to 1.14 for FEP; and 4.96 to 11.73% for FEMg. Linear relationships between the clearance and fractional excretion of electrolytes were observed on base-10 logarithmically transformed data for Na, Ca, P, and Mg. Linear relationship was not found between CK and FEK or between CCl and FECl.
Afficher plus [+] Moins [-]Comparative study of the pharmacokinetics of alfentanil in rabbits, sheep, and dogs
1991
Ilkiw, J.E. | Benthuysen, J.A. | McNeal, D.
The central arterial pharmacokinetics of alfentanil, a short-acting opioid agonist, were studied in rabbits, sheep, and dogs after short-duration infusion of the drug. Alfentanil was infused until a set end point (high-amplitude, slow-wave activity on the EEG) was reached. This required a larger alfentanil dose and a higher alfentanil arterial concentration in sheep, compared with rabbits and dogs. The plasma concentration-time data for each animal were fitted, using nonlinear regression, and in all animals, were best described by use of a triexponential function. In this study, differences in the disposition kinetics of alfentanil among the 3 species were found for only distribution clearance and initial distribution half-life. In dogs, compared with rabbits and sheep, the first distribution half-life was longer, probably because of pronounced drug-induced bradycardia (mean +/- SD, 48 +/- 21 beats/min). Distribution clearance was faster in sheep, compared with dogs, also probably because of better blood flow in sheep. Elimination half-life was similar in all species (rabbits, 62.4 +/- 11.3 minutes; sheep, 65.1 +/- 27.1 minutes; dogs, 58.3 +/- 10.3 minutes). This rapid half-life resulted from a small steady-state volume of distribution (rabbits, 908.3 +/- 269.0 ml/kg; sheep, 720.0 +/- 306.7 ml/kg; dogs, 597.7 +/- 290.2 ml/kg) and rapid systemic clearance (rabbits, 19.4 +/- 5.3 ml/min/kg; sheep, 13.3 +/- 3.0 ml/min/kg; dogs, 18.7 +/- 7.5 ml/min/kg). On the basis of these pharmacokinetic variables, alfentanil should have short duration of action in rabbits, sheep, and dogs. This may be beneficial in veterinary practice where rapid recovery would be expected after bolus administration for short procedures or after infusion for longer procedures.
Afficher plus [+] Moins [-]In vitro responses of distal airways in horses with recurrent airway obstruction
1991
Distal airway segments (ID, 3 to 4 mm; length, 5 mm) from 2 groups of horses were isolated and suspended in tissue baths filled with Krebs solution, aerated with 5% CO2 in oxygen and maintained at 37 C. Responses to exogenous acetylcholine, isoproterenol, or electrical field stimulation were compared. Control horses (n = 30) had no history of recurrent airway obstruction, whereas principal horses (n = 15) had recurrent airway obstruction and were studied during an acute episode of airway obstruction. Although the distal airways contracted in response to the cumulative half-logarithmic addition of acetylcholine (10(-10)M to 10(-3)M) in both groups, bronchi obtained from principals were less sensitive to acetylcholine than were bronchi obtained from controls. Tetrodotoxin-sensitive electrical field stimulation-induced contractions were observed in both groups of airways, but the tension achieved in principal bronchi was less than in controls. All electrical field stimulation-induced contractions were abolished by atropine, indicating that the only excitatory innervation of equine distal airways is through the parasympathetic system. To examine the effect of isoproterenol and determine inhibitory innervation, bronchi were precontracted with histamine. Electrical field stimulation did not cause relaxation of precontracted bronchi in either group, thus indicating that distal airways lack inhibitory innervation. Isoproterenol caused similar, dose-dependent relaxation in both groups.
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