ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1980.tb00480.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1980.tb00481.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

In cats, xylazine, an analogue of clonidine, produced hyperglycaemia when injected intravenously. The effect was obtained in unanaesthetized cats and in pentobarbitone sodium anaesthesia. The hyperglycaemia was not a central effect, nor due to adrenaline release from the adrenals, nor to a direct action of xylazine on the liver. It resulted from a fall in plasma insulin produced by an action of xylazine on the pancreas, inhibiting insulin secretion without affecting glucagon secretion. The increase in the glucagon/insulin ratio, by stimulating glucose production in the liver, was probably responsible for the xylazine‐induced hyperglycaemi

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1980.tb00482.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Xylazine administered subcutaneously (s.c.; 1–4 mg/kg) or intravenously (i.v.; 0.5‐2 mg/kg) to cats consistently caused dose‐related decreases in body temperature which were maximal 3–4 h after injection and lasted for at least 12 h. Otherwise the animals appeared to have recovered fully from the central nervous system effects of the drug within 1.5–3.5 h. Xylazine‐induced hypothermia developed more rapidly in cats placed in a 4°C environment and, in contrast, was replaced by a hyperthermic response in cats placed in a 32°C environment. These changes in body temperature were not opposed by compensatory thermoregulatory effector activity such as shivering or tachypnea. This pattern of responses at varied environmental temperatures is indicative of a general depression of the thermo‐regulation. Thus, animals given xylazine should not be exposed to extreme heat or cold for several hours to avoid development of hyper

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1980.tb00483.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The pharmacokinetics of digoxin were investigated in five 15‐day‐old puppies. Following administration of 30 μg/kg digoxin intravenously, multiple serum samples were collected and assayed by radioimmunoassay. Data was analysed by non‐linear least squares regression analysis.The mean biological half‐life of digoxin in puppies was 22.7 h and the mean volume of distribution by extrapolation was 14.4 litres/kg. The data collected along with data from the literature was applied to standard pharmacokinetic equations to formulate tentative doses of digoxin. The maintenance doses calculated for puppies were, in μg/kg/24 h, 15 for the intravenous injection, 18 for the pediatric elixir and 22 for the tablet.When the above doses of digoxin were administered to six 31‐day‐old Beagle pups, resultant plasma digoxin concentrations measured over 12 days were mostly lower than expected but were nevertheless within the proposed therapeutic, non‐toxic range of 0

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1980.tb00484.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1980.tb00485.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The activity of a range of antibiotics on intracellularStaphylococcus aureuswas examined using anin vitrosystem in which staphylococci survived within bovine neutrophils and extracellular organisms were killed by lysostaphin. Cloxacillin in the presence of lysostaphin caused a reduction in the number of viable intracellularS. aureusbut cloxacillin alone failed to reduce such bacteria significantly. The cloxacillin appeared to sensitize the staphylococci to lysis by extracellular traces of lysostaphin following neutrophil disruption. Extracellular staphylococci which remained viable after exposure to cloxacillin in the absence of lysostaphin were subsequently killed more rapidly by neutrophils, but this was not found with bacteria exposed to cloxacillin while inside cells. Vancomycin with lysostaphin produced a similar but smaller sensitization effect but this antibiotic also appeared to increase survival of intracellular staphylococci when compared with controls, possibly by impeding neutrophil bactericidal mechanisms. The only other antibiotic to show significant intracellular killing was rifampicin, and in this case the action was independent of lysostaphin.

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1980.tb00486.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The minimal inhibitory concentrations of fifteen antibacterial agents were determined by agar‐dilution method against 121 strains ofClostridium perfringensisolated from pigs, cattle and poultry. All strains, regardless of host of origin, were susceptible to avoparcin, furazolidone, monensin, nitrovin, penicillin G, ronidazole and tiamulin and resistant to flavomycin. Poultry strains were also susceptible to carbadox, chloramphenicol, erythromycin and virginiamycin. Bacitracin‐resistant poultry strains were susceptible to all tested antibacterial agents except tetracycline, but the bacitracin‐resistant cattle strains were polyresistant. Porcine strains were susceptible to bacitracin and bovine strains to carbadox. Carbadox‐resistant porcine strains were resistant to erythromycin, lincomycin and tetracycline and susceptible to chloramphenicol. Resistance to erythromycin was associated with resistance to lincomycin. High level erythromycin‐lincomycin‐resistant strains were susceptible to virginiamycin, but the intermediate level erythromycin‐lincomycin‐resistant cattle strains were resistant to virginiamycin. Resistance to chloramphenicol or erythromycin‐lincomycin was always associated with resistance to tetracycline but the reverse wa

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1980.tb00487.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The concentration of serum phenytoin was determined in normal dogs following the administration of phenytoin by either the intravenous or oral route. An intravenous dose of 11 and 33 mg/kg of body weight was given to six dogs and a further dose of 44 mg/kg was given to two dogs. Serial blood samples were taken following the three doses for determination of pharmacokinetic parameters. The mean half‐life was3.35, 3.84and4.57h as the dose was increased. Signs of toxicity occurred immediately following the infusion of phenytoin (emesis, ataxia and seizures). In the first oral studies, serial blood samples were taken for 2 consecutive days following a dose of 11 and 88 mg/kg, t.i.d. The time—concentration profiles of phenytoin varied significantly from one day to the next in the same dog. In the second oral study, blood samples were taken at 3 and 7 h following a dose of 11, 22, 44, 66 and 88 mg/kg, t.i.d. There was a poor correlation between the size of the oral dose and the concentration of serum phenytoin. Due to the short half‐life and poor absorption of phenytoin in dogs, it was concluded that the oral administration of phenytoin in dogs produces sub‐therapeutic and erratic serum concentrations of phenytoin which makes its efficacy as an anti‐convulsant que

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1980.tb00488.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

A radioimmunoassay (RIA) method for hexoestrol using an antiserum against hexoestrol‐carboxypropyl ether‐BSA and H3‐hexoestrol was used to measure the concentrations of residues of hexoestrol in 0.1 ml biological fluids and 1 g edible tissues of implanted cattle and sheep. A preliminary ether extraction of biological fluids was necessary before RIA. The ether extract from tissues was further purified by solvent partition and silica gel column chromatography before RIA. Conjugates of hexoestrol were measured after enzymatic hydrolysis to free hexoestrol. In untreated animals residues were either not detected or very low in all tissues except urine from sheep. The method has a lower limit of detection of approximately 0–10 pg/ml for biological fluids in cattle and 20–100 pg/g for tissues in both sheep and cattle but the lower limit of detection in sheep urine was 70–294 pg/ml urine.In two heifers implanted with 60 mg hexoestrol and slaughtered 2 and 7 days after implantation, residues of hexoestrol were detected in all tissues except muscle with highest concentrations between 2 ‐ 17 ng/g in urine, bile and kidney. The concentration of residues in steers which had been implanted with 45 mg or 60 mg hexoestrol and slaughtered at 90 days after implantation were 0,<50, 46–96 and 200 pg/ml or g of plasma, muscle, liver and urine, respectively. The concentrations of hexoestrol in sheep implanted with 15 ml hexoestrol and slaughtered after 60 days were 70, 0, 964, 3100 and 4074 pg/g or ml of muscle, fat, liver, kidney and urine, respectively. No hexoestrol was found in control untreated cattle and sheep. It was concluded that some residues of hexoestrol were present in the excretory fluids and tissues of cattle and sheep which had been implanted with hexoestrol at the recommended dose and slaughtered after the recommended withdrawal periods. However, the concentrations of hexoestrol in muscle and fat were extremely low or not detectable. The method could be used for the routine screening of animals for treatment

ISSN:0140-7783    

DOI:10.1111/j.1365-2885.1980.tb00489.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY