摘要:

This paper presents a method of determining a confidence interval for the drug half‐life based on statistical properties of the estimates of the disappearance rate constant of the drug. This interval is shown to be of minimum length which indicates it is a more precise estimate than others currently in use. A computer program to construct these intervals is available upon reques

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1990.tb00740.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Uterine infections are associated with reduced fertility in ruminant species. Spiramycin is a macrolide antibiotic potentially active against most of the microorganisms isolated from secretions of infected genital tracts. The present work investigated the ability of systemically administered spiramycin to enter genital secretions, by determining the disposition kinetics of the antibiotic in both plasma and uterine genital secretions. Five healthy ovariectomized ewes were given a single intravenous (i.v.) injection of spiramycin, at a dose of 20 mg/ kg. Plasma and genital secretion samples were collected at predetermined intervals for 5 days post‐injection. Blood was collected from the jugular vein while mucus was obtained by inserting polyurethane sponges into the vagina. The spiramycin concentration peak in genital‐tract secretions was obtained 2.53 ±0.63 h after the i.v. administration. The mean residence time was significantly longer (P<0.01) in the mucus (18.31±3.24 h) than in plasma (6.99±2.53 h). An average mucus to plasma ratio of 7.87±3.00 was calculated from the area under concentration‐time curves covering the period under study. These data indicate that after systemic administration to ewes, spiramycin is rapidly found in genital‐tract secretions, at concentrations which are sufficiently high and persistent to suggest its use in the treatment of post‐partum uteri

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1990.tb00741.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Atipamezole reversed the sedative effect of medetomidine in twelve laboratory beagles. The dogs were sedated with medetomidine doses of 20, 40 and 80 μg/kg body wt i.m. Atipamezole was injected (i.m.) 20 min later at dose rates two, four, six and ten times higher (in μg/kg) than the preceding medetomidine dose. Placebo treatment was included in the study. The deeply sedated dogs showed signs of arousal in 3‐7 min and took their first steps 4‐12 min after atipamezole injection. The dose‐related reversal effect of atipamezole proved to be optimal with doses which were four, six or ten times higher than the preceding medetomidine dose. Drowsiness was found 0.5‐1 h after atipamezole injection in 41% of the cases. No adverse effects nor cases of over‐alertness or excitement

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1990.tb00742.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Levamisole administered by oral, subcutaneous or transdermal routes following vaccination againstPasteurella multocidaenhanced the humoral response in crossbred calves. The group that received levamisole subcutaneously elicited highly significant (P<0.01) antibody titres during the primary humoral response in comparison with groups that received levamisole orally or transdermally. During the secondary response in the same experiment, levamisole administered subcutaneously and transdermally showed highly significant (P<0.01) haemagglutination titres relative to oral administration of the drug. In a second experiment, the group that received levamisole subcutaneously showed highly significant (P<0.01) antibody titres during the anamnestic humoral response over other treated groups.

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1990.tb00743.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The α2agonist xylazine produced a dose‐dependent decrease in mean arterial blood pressure in conscious rabbits when injected intrathecally (i.t.) through a cannula previously implanted under general anaesthesia. Intrathecal administration of 200 and 400 μg of xylazine produced a significant reduction in arterial blood pressure from control values (maximum depressions of 25% and 33%, respectively). There was little effect on cardiac output and arterial carbon‐dioxide tension and no effect on respiratory rate, arterial oxygen tension and pulse rate. Intrathecal injection of 100 μl of 0.9% saline had no effect. Intravenous (i.v.) tolazoline (0.5 mg/kg) abolished xylazine‐induced hypotension (200 μg) in four rabbits. Contrast radiography revealed that 100 μl of solution injected i.t. in anaesthetized rabbits spread distally over eight vertebral spaces. There was little rostral spread. It was concluded that xylazine‐induced hypotension following i.t. injection was due to local activation of α2adrenoceptors present in the thoracic spinal cord. It is postulated that spinal α2adrenoceptors may play an important role in the hypotension recorded in animals after parenteral injecti

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1990.tb00744.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Plasma estradiol‐17ß concentrations were investigated in cows during induced estrus and after an intramuscular injection of 10 mg of estradiol‐17ß benzoate and estradiol‐17ß cypionate to determine a withdrawal period for both preparations. After the estradiol‐17ß benzoate injection, the plasma estradiol‐17ß concentration was higher than the physiological maximum of 24 pg/ml obtained during induced estrus for a period of 114±10 h (mean±SEM). For estradiol‐17ß cypionate the corresponding value was 170ß17h (mean±SEM). A withdrawal period of 7 days for the benzoate ester and of 10 days for estradiol‐17ß cypionate is therefore proposed. These results were confirmed by biopsies taken at the injection site 8 and 15 days after the injection of estradiol‐17ß benzoate and estradiol‐17ß cypionate, respectively. In these biopsies no residues of estradiol‐17ß no

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1990.tb00745.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The pharmacokinetics of potassium penicillin G were studied in both healthy (n = 8) and experimentallyStreptococcus‐suis‐infeaed (n = 6) pigs following intramuscular administration (15 000 iu/kg).Streptococcus‐suisinfection was induced artificially in young cross‐bred pigs by subcutaneous inoculation with 9 × 108to 109colony‐forming units of S. suis. The rectal temperature of infected pigs was significantly increased (P<0.01) before penicillin G injection and this was maintained for 8 h after the drug was given. Other clinical symptoms were also present. The serum concentration‐time data for penicillin were found to fit a one‐compartment open model with first‐order absorption in the two groups of pigs. Significant changes were not observed between healthy and diseased pigs in following parameters: A, Ka, Keand Tmax‐However, in diseased pigs, significant increases (P<0.01) were found in Vdand ClB, and significant decreases (P<0.01) in Cmaxand AUC occurred. The increased body clearance (ClB) and greater apparent volume of distribution (Vd) of penicillin G could partly explain why the serum values of the drug were much lower in diseased pigs th

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1990.tb00746.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Chlortetracycline hydrochloride was administered intra‐arterially (11 mg/kg) and as an oral drench (33 mg/kg) to ten 21.0‐31.5‐kg pigs. Five of the pigs were fasted 18 h prior to dosing and five of the pigs were fedad libitumprior to dosing. The mean volume of distribution determined by area‐under‐the‐curve calculations for the fasted pigs (0.967 ± 0.210 1/kg) was significantly less (P<0.05) than the mean volume of distribution for the fed pigs (1.39 ± 0.31 1/kg). Mean total body clearance of the drug was also significantly less (P<0.05) in the fasted pigs (0.165 ± 0.055 1/kg/h) as compared to the fed pigs (0.307 ± 0.053 1/kg/h). The elimination constants (ß) were not found to be statistically different (P<0.05): 0.1811 ± 0.0057 for the fasted pigs; 0.2260 ± 0.0461 for the fed pigs. The bioavailability for both groups was similar; 19.12 ± 8.3% for the fasted pigs and 17.88 ± 5.3% for the fed pigs.In a second experiment three groups of six pigs which weighed 34.5‐44.1 kg were fed a corn‐soy dietad libitum.The rations were fortified with chlortetracycline at 100, 400 or 1000 mg chlortetracycline hydrochloride/kg feed. Chlortetracycline concentrations were determined in plasma samples collected over a 6‐day period. Plasma chlortetracycline concentrations reach a plateau within 24 h after initial access to the trial diets and were highly correlated with the dose of th

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1990.tb00747.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Polymorphonuclear leukocytes (PMNLs) were isolated from an inflammatory exudate induced in the intercarpal joints of horses by an administration of carrageenin. Their superoxide production at rest and following stimulation with either serum‐treated zymosan (STZ) or phorbol myristate acetate (PMA) was measured by cytochrome‐c reduction. Stimulation of the cells increased the cytochrome‐c reduction 10‐15 times that of resting cells. The maxima were 20 nmol of reduced cytochrome‐c per 106cells per ml at 120 min (STZ) and 35 nmol of reduced cytochrome‐c per 106cells per ml at 60 min (PMA). The maximum inhibition of the cytochrome‐c reduction by superoxide dismutase (Paloseinr̀) was 83.6% (STZ stimulation) and 72.1% (PMA stimulation). The non‐steroidal anti‐inflammatory drugs, phenylbutazone, salicylic acid, aspirin, sodium salicylate in addition to D‐penicillamine and dimethylsulfoxide caused dose‐dependent inhibition of the cytochrome‐c reduction when the cells were stimulated by PMA. The maximum inhibitions were 64% and 36% for aspirin (10‐2m), 32% and 17% for phenylbutazone (10‐3m), 15% and 31% for dimethylsulfoxide (6.4 times 10‐1M), 32% and 19% for salicylic acid (10‐2M), 0% and 17% for sodium salicylate (10‐2M) and 2.2% and 2.5% for D‐penicillamine (10‐4M) when the cells were stimulated by STZ and PMA, respectively. The results indicate that equine PMNLsmigrating from the vascular bed into the joint are a potential source of superoxide and that superoxide dismutase at achievable synovial fluid concentrations following intra‐articularly administered Paloseinr̀, and NSAIDsat concentrations above those achieved in plasma from therapeutic dose rates, may protect tissue from superoxide produced by eq

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1990.tb00748.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Topically applied copper phenylbutazone, phenylbutazone, copper salicylate, salicylate and dimethylsulfoxide glycerol (80:20) were investigated as antiinflammatory agents in rats and horses. Dimethylsulfoxide and glycerol (80:20) or dimethylsulfoxide, ethanol and glycerol (60:20:20) were used as the drug solvents. Subcutaneously administered carrageenin was used to induce inflammatory oedema, either in the paws of rats or the alar fold of the horse. The severity of the oedema and the anti‐inflammatory effect of the drugs were assessed by measuring changes in the paw or alar‐fold diameters. Copper salicylate and copper phenylbutazone were effective inhibitors of the inflammatory oedema in both species, but dimethylsulfoxide:glycerol (80:20) was not. In the rat, copper salicylate and copper phenylbutazone were superior antiinflammatory agents compared to either salicylate or phenylbutazone, respectively. Following the topical application of four times the recommended daily dose of copper phenylbutazone to the horse for 5 days, minor skin irritation occurred and trace concentrations of phenylbutazone (maximum 0.6 μg/ml) and negligible concentrations of oxyphenbutazone and ß‐hydroxyphenylbuta‐zone were detected in t

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1990.tb00749.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY