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The pharmacokinetics of marbofloxacin were investigated in healthy (n=8) and Mannheimia haemolytica naturally infected (n=8) Simmental ruminant calves following intravenous (i.v.) and intramuscular (i.m.) administration of 2 mg kg(-1) body weight. The concentration of marbofloxacin in plasma was measured using high performance liquid chromatography with ultraviolet detection. Following i.v. administration of the drug, the elimination half-life (t(1/2 beta)) and mean residence time (MRT) were significantly longer in diseased calves (8.2h; 11.13 h) than in healthy ones (4.6 h; 6.1 h), respectively. The value of total body clearance (CL(B)) was larger in healthy calves (3 ml min(-1) kg(-1)) than in diseased ones (1.3 ml min(-1) kg(-1)). After single intramuscular (i.m.) administration of the drug, the elimination half-life, mean residence time (MRT) and maximum plasma concentration (C(max)) were higher in diseased calves (8.0, 12 h, 2.32 microg ml(-1)) than in healthy ones (4.7, 7.4 h, 1.4 microg ml(-1)), respectively. The plasma concentrations and AUC following administration of the drug by both routes were significantly higher in diseased calves than in healthy ones. Protein binding of Marbofloxacin was not significantly different in healthy and diseased calves. The mean value for MIC of marbofloxacin for M. haemolytica was 0.1+/-0.06 microg ml(-1). The C(max)/MIC and AUC(24)/MIC ratios were significantly higher in diseased calves (13.0-64.4 and 125-618 h) than in healthy calves (8-38.33 and 66.34-328 h). The obtained results for surrogate markers of antimicrobial activity (C(max)/MIC, AUC/MIC and T > or = MIC) indicate the excellent pharmacodynamic characteristics of the drug in diseased calves with M. haemolytica, which can be expected to optimize the clinical efficacy and minimize the development of resistance. 相似文献
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《Veterinary anaesthesia and analgesia》2023,50(2):121-128
ObjectiveTo determine the effect of remifentanil infusion on the minimum alveolar concentration of sevoflurane preventing movement (SEVOMACNM) and bispectral index (BIS) in dogs.Study designProspective, unmasked study.AnimalsA total of 10 adult Beagle dogs weighing 9.0 ± 1.1 kg.MethodsDogs were anesthetized with sevoflurane and baseline SEVOMACNM was determined. Remifentanil was infused at 5, 10 and 20 μg kg–1 hour–1, in sequence, with 20 minutes washout between infusions. Variables monitored throughout anesthesia included heart rate (HR), oscillometric blood pressure, end-tidal partial pressure of carbon dioxide, end-tidal sevoflurane concentration (Fe′Sevo) and BIS. SEVOMACNM after remifentanil infusion (SEVOMACNM-REMI) determination started 20 minutes after the start of each infusion. Venous blood samples were collected for plasma remifentanil concentration determination at baseline, SEVOMACNM-REMI determination time points, and 20 minutes after each infusion was stopped. A mixed model analysis was used to determine the effect of remifentanil infusion on response variables. The relationships between BIS and Fe′Sevo, plasma remifentanil concentrations and the percentage decrease in baseline SEVOMACNM were evaluated (p < 0.05).ResultsThe overall SEVOMACNM at baseline was 2.47 ± 0.11%. Addition of remifentanil at all infusion rates significantly decreased SEVOMACNM, but the medium and high doses resulted in significantly greater decreases in SEVOMACNM than the lower dose. There was no difference in SEVOMACNM percentage change between infusions 10 and 20 μg kg–1 hour–1. Plasma remifentanil concentrations were significantly different in all infusion rates. Baseline BIS value was 70 ± 1 and was lower than the BIS values recorded during all remifentanil infusions. BIS values were not significantly different among infusion rates. HR was lower and mean arterial pressure was higher during remifentanil infusions than at baseline.Conclusions and clinical relevanceAll remifentanil infusions decreased SEVOMACNM in dogs. Remifentanil infusion at any rate studied did not reduce BIS values. 相似文献
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The author introduces a method and experimental procedures that determine dn/dc,molecular weight and its distribution of the hyroxyethyl starch(HES) by means of Gel Permeation Chromatography-Refractive index-Multi-angle laser light scattering detection(GPC-RI-MALLS)techniques.The key experimental technique and results are discussed.The method takes CH3COOH/CH3COONa as mobile phase and solvent.The experiment gets satisfactory results.It can be used as a routine method to determine the hyroxyethyl starch(HES) molecular weight and its distribution. 相似文献
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This papar presents an evolution model in business behaviors-the L-S Business Strategies,gives some examples and predictions which support these strategies,and analyzes the relationship between the industrial organizations in China and the L-S Business strategies. 相似文献
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以应力分析法和ANSYS有限元法分别对加氢反应器接管补强部位进行了应力分析,结果表明:最大应力出现在反应器上封头与接管的内壁交界处。通过分析得知,用ANSYS软件分析反应器接管补强部位的应力比传统应力分析法更直观方便,计算相对更精确省时。 相似文献