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排序方式: 共有169条查询结果,搜索用时 15 毫秒
1.
Pharmacokinetics of multiple doses of transdermal flunixin meglumine in adult Holstein dairy cows 下载免费PDF全文
M. D. Kleinhenz P. J. Gorden J. S. Smith J. A. Schleining K. E. Kleinhenz L. L. Wulf P. K. Sidhu D. Rea J. F. Coetzee 《Journal of veterinary pharmacology and therapeutics》2018,41(3):490-493
A transdermal formulation of the nonsteroidal anti‐inflammatory drug, flunixin meglumine, has been approved in the United States and Canada for single‐dose administration. Transdermal flunixin meglumine was administered to 10 adult Holstein cows in their second or third lactation at the label dose of 3.33 mg/kg every 24 hr for three total treatments. Plasma flunixin concentrations were determined using high‐pressure liquid chromatography with mass spectroscopy (HPLC ‐MS ). Pharmacokinetic analysis was completed on each individual animal with noncompartmental methods using computer software. The time to maximum drug concentration (T max) was 2.81 hr, and the maximum drug concentration was 1.08 μg/ml. The mean terminal half‐life (T½) was determined to be 5.20 hr. Clearance per fraction absorbed (Cl/F) was calculated to be 0.294 L/hr kg?1, and volume of distribution of fraction (V z/F ) absorbed was 2.20 L/kg. The mean accumulation factor was 1.10 after three doses. This indicates changes in dosing may not be required when giving multiple doses of flunixin transdermal. Further work is required to investigate the clinical efficacy of transdermal flunixin after multiple daily doses. 相似文献
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AIMS: To determine the variability of concentrations of Zn in feed, when used as a supplement to prevent facial eczema, and to determine the variability in concentrations of Zn in serum between cows and herds that are being supplemented with ZnO in feed, using in-shed feeders or on a feed pad.METHODS: Sixteen commercial dairy farms in the Waikato region of New Zealand were enrolled, that were supplementing cows with ZnO in the feed using either an automatic in-shed feeder (ASF) or a feed pad (FP) using a feed-out or mixer wagon. On each farm 10 cows were selected by the farmer, that were assumed to be representative of the age and liveweight of the herd. Four hours after supplement feeding, each cow was weighed and a blood sample collected for measurement of concentrations of Zn in serum. Three samples of feed were collected from each farm for Zn analysis, from the beginning, middle and end of the feed being distributed. Levene’s test for homoscedasticity was used to analyse whether there were differences in variation of individual concentrations of Zn in serum, and in the feed, between the two feeding systems. Multivariable linear regression was used to examine associations between age, feeding method or liveweight and concentrations of Zn in serum, after accounting for the variability between farms.RESULTS: Of the 163 cows sampled, concentrations of Zn in serum were between 20–35?µmol/L in 75/163 (46 (95% CI=38–54)%) cows; were <20?µmol/L in 71/163 (44 (95% CI=36–52)%) cows, and >35?µmol/L in 17/163 (10 (95% CI=6–16)%) cows. The variation in concentrations of Zn in serum in individual cows differed between farms (p<0.001), and the variability was greater for cows fed using a FP than ASF (p<0.001). There was no difference in the variation of concentrations of Zn in feed between the two feeding methods (p=0.54), but concentrations of Zn in serum were associated with the amount of Zn offered in feed (p=0.008).CONCLUSIONS AND CLINICIAL RELEVENCE: There was significant variability between farms in the concentrations of Zn in the serum of cows being supplemented with ZnO in feed. Only 46% of cows sampled had concentrations of Zn between 20–35?µmol/L. Effective management of facial eczema should include monitoring Zn in the feed and in serum to ensure cows are receiving the correct dose they require. 相似文献
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Der 1967 in Seehausen auf sandigem Lehm angelegte Düngungs‐Kombinationsversuch dient der Analyse von Langzeitwirkungen gestaffelter Stallmist‐ und Mineral‐N‐Gaben (0,50,100,150 kg N ha?1 a?1) auf Pflanzen, Boden und Umwelt. Anhand von Meß‐, Bilanz‐ und Simulationswerten wird die Nachhaltigkeit dieser Düngungsvarianten bewertet. Organisch‐mineralische Düngung führte zu Maximalerträgen von über 12t TM ha?1 a?1 und N‐Entzügen bis 200 kg ha?1 a?1. Der N‐Entzug der ungedüngten Variante betrug in den letzten Jahren noch etwa 75 kg ha?1a?1 gegenüber 100 kg ha?1a?1 zu Versuchsbeginn. Die Entwicklung der Boden‐Nt‐Gehalte konnte mit e‐Funktionen beschrieben werden. Mineral‐N allein genügte nicht zum Erhalt der Nt‐Ausgangsvorräte, hierfür waren 55 bis 85 kg Stalldung‐N ha?1 a?1 notwendig. Die Nt‐ und Ct‐Gehalte korrelierten mit zahlreichen Bodenparametern. Hohe Humusgehalte forderten die biologische Aktivität. Die N‐Verluste betrugen <10kg ha?1 a?1 (ungedüngt) bis 120 kg ha?1a?1 (höchstgedüngte Variante). Das N‐Verlustpotential lag bei Stallmistanwendung etwas niedriger als bei gleicher N‐Zufuhr in Mineralform. Je nach Stallmist‐Stufe waren 62 bis 104 kg Mineral‐N ha?1 a?1 erforderlich, um den Energieeinsatz je Produkteinheit zu minimieren. Kombinierte Anwendung organischer und mineralischer Dünger (je 100 kg N ha?1 a?1) führte zu höchsten ökonomischen Leistungen, günstigen Bodeneigenschaften und tolerierbaren Umweltwirkungen. Zieht man alle verwendeten Nachhaltigkeitskriterien in Betracht, ist dieses Düngungssystem den anderen überlegen. 相似文献
5.
Impact of an experimental PRRSV and Streptococcus suis coinfection on the pharmacokinetics of ceftiofur hydrochloride after intramuscular injection in pigs 下载免费PDF全文
D. N. Day J. W. Sparks L. A. Karriker K. J. Stalder L. W. Wulf J. Zhang J. M. Kinyon M. L. Stock R. Gehring C. Wang J. Ellingson J. F. Coetzee 《Journal of veterinary pharmacology and therapeutics》2015,38(5):475-481
This study determined the impact of porcine reproductive and respiratory syndrome virus (PRRSV) and Streptococcus suis coinfection on the pharmacokinetic (PK) profile of ceftiofur hydrochloride in pigs after intramuscular (i.m.) injection. Eighteen clinically normal crossbred gilts were assigned by weight into a challenge group (10 pigs) and control group (eight pigs). Pigs in both groups received a single i.m. injection of ceftiofur hydrochloride (Excenel RTU Sterile Suspension; Zoetis) at a 5 mg/kg BW dose. Serial blood samples were collected to characterize the plasma concentration curve. After a 10 days drug washout period, the challenge group was inoculated with 2 mL of PRRSV isolate VR‐2385 (105.75 50% tissue culture infective doses per mL) intranasally and 8 days later inoculated S. suis. When clinical disease was evident, the second PK assessment began in both challenge and control groups. Coinfected pigs demonstrated lower values of AUC and CMAX, but higher values of Cl/F and Vz/F indicating drug kinetics were altered by infection. The data from this study have implications on ceftiofur treatment regimens in diseased pigs. 相似文献
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M. L. Stock R. Gehring L. A. Barth L. W. Wulf J. F. Coetzee 《Journal of veterinary pharmacology and therapeutics》2014,37(5):457-463
The objective of this study was to determine the pharmacokinetics of intravenous and oral firocoxib in 10 healthy preweaned calves. Firocoxib (0.5 mg/kg) was initially administered i.v. to calves, and following a 14‐day washout period, animals received firocoxib orally prior to cautery dehorning. Firocoxib concentrations were determined by liquid chromatography–tandem mass spectrometry. Changes in hematology and plasma chemistry were determined using automated methods. Computer software was used to estimate pharmacokinetic parameters best described with a two‐compartment model for i.v. administration and a one‐compartment model for p.o. administration. Following i.v. dosing, the geometric mean (range) T1/2K10 and T1/2β were 6.7 (4.6–9.7) and 37.2 (23.5–160.4) h, respectively, Vss was 3.10 (2.10–7.22) L/kg, and CL was 121.7 (100.1–156.7) mL/h/kg. Following oral administration, geometric mean (range) Cmax was 127.9 (102.5–151.3) ng/mL, Tmax was 4.0 (2.6–5.6) h, and T1/2K10 was 18.8 (14.2–25.5) h. Bioavailability of oral firocoxib was calculated using the AUC derived from both study populations to be 98.4% (83.1–117.6%). No adverse clinical effects were evident following firocoxib administration. Pharmacokinetic analysis of i.v. and p.o. firocoxib indicates high bioavailability and a prolonged terminal half‐life in preweaned calves. 相似文献
8.
AM Batista WA Gomes CCD Carvalho PLJ Monteiro Jr FLM Silva FC Almeida PC Soares GF Carneiro MMP Guerra 《Reproduction in domestic animals》2014,49(3):476-480
The aim of this study was to evaluate the effect of leptin administration during superovulation on in vivo goat embryo production. Ten mature does were superovulated with 133 mg follicle‐stimulating hormone (FSH) i.m. in six descending doses at 12‐h intervals. The goats received 4.8 μg/kg human recombinant leptin s.c. (leptin group, n = 5) or phosphate‐buffered saline (PBS) (control group, n = 5) with the first and second FSH doses. The does were mated and subjected to embryo collection by transcervical technique 6 days later. The total number of cells per embryo and the number of cells with fragmented DNA were assessed in selected blastocysts by combining Hoechst 33342 and terminal dUTP nick‐end labelling (TUNEL) staining. Plasma concentrations of oestradiol (E2) and progesterone (P4) were determined by electrochemiluminescence from the day of FSH treatment, on the day of superovulatory oestrus and on the day before embryo collection. Compared with the control group, the does that received leptin had a higher number of transferable embryos (p < 0.005), fewer embryos classified as degenerated (p < 0.001) and fewer TUNEL‐positive cells/blastocyst (p < 0.001). The number of transferable embryos was positively correlated with E2 concentrations on day of oestrus (r = 0.562; p < 0.01) and P4 concentrations on the day of embryo collection (r = 0.912; p < 0.001). We concluded that in vivo leptin administration during FSH treatment improved embryo quality and affected ovarian steroidogenesis in superovulated goats. 相似文献
9.
Nasopharyngeal cryptococcosis 总被引:1,自引:0,他引:1
R MALIK P MARTIN DI WIGNEY DB CHURCH W BRADLEY CR BELLENGER WA LAMB VR BARRS S FOSTER S HEMSLEY PJ CANFIELD DN LOVE 《Australian veterinary journal》1997,75(7):483-488
Naturally occurring cryptococcosis in five cats, a dog and a koala is described. Involvement of the nasopharynx was documented in all patients, and nasopharyngeal mass lesions accounted for the major presenting complaints in four. Signs referable to nasopharyngeal disease included snoring, stertor, inspiratory dyspnoea and aerophagia. Diagnoses were made by caudal rhinoscopy using a retroverted flexible endoscope, vigorous orthograde flushing with saline, or at necropsy. Concurrent cryptococcal rhinitis was present in all cases, although involvement appeared limited to the caudal nasal cavity in most cases. Typical signs of nasal cavity disease, such as sneezing and nasal discharge, were often absent. Treatment of nasopharyngeal cryptococcosis should include physical dislodgement or debulking of lesion(s) to provide immediate alleviation of upper airway obstruction, followed by systemic antifungal therapy to eliminate residual infection from the nasal cavity. Infections caused by Cryptococcus neoformans var gattii accounted for a disproportionately large number of these cases. 相似文献
10.
Static and dynamic mechanical deflections were electrically induced in cantilevered, multiwalled carbon nanotubes in a transmission electron microscope. The nanotubes were resonantly excited at the fundamental frequency and higher harmonics as revealed by their deflected contours, which correspond closely to those determined for cantilevered elastic beams. The elastic bending modulus as a function of diameter was found to decrease sharply (from about 1 to 0.1 terapascals) with increasing diameter (from 8 to 40 nanometers), which indicates a crossover from a uniform elastic mode to an elastic mode that involves wavelike distortions in the nanotube. The quality factors of the resonances are on the order of 500. The methods developed here have been applied to a nanobalance for nanoscopic particles and also to a Kelvin probe based on nanotubes. 相似文献