Sedative effects and serum concentrations across time after subcutaneous administration of liposome-encapsulated or standard oxymorphone in healthy dogs     

LJ Smith  L Krugner-Higby 《Veterinary anaesthesia and analgesia》2005,32(4):12-12

Our lab has developed a slow‐release liposomal formulation of oxymorphone (LEOx). The purpose of this study was to compare sedative effects and serum concentrations of oxymorphone after administration of LEOx and standard oxymorphone (STDOx) to dogs. At baseline, 1 mL of blood was drawn from the cephalic vein and sedation score was recorded. Dogs were divided into four groups (n = 6): (i) LEOx 1.0 mg kg^–1; (ii) LEOx 0.5 mg kg^–1; (iii) STDOx 0.1 mg kg^–1; (iv) STDOx 0.05 mg kg^–1. Unloaded liposomal vehicle (0.5 mL) was used as a control (n = 2). All treatments were given subcutaneously between the scapulae. Sedation score and serum concentration of drug were recorded at 0.5, 1, 2, 4, 8, 12, 16, 24 hours and daily for 5 days. Serum concentrations were measured with ELISA. At all time points, drug was not detected and sedation score was 0 in the control group. Sedation score for group 1 was significantly higher (p < 0.05) at 1 hour than for groups 2,3, and 4. There was no difference in sedation score between treatment groups at any other time. Serum concentrations of drug were significantly higher (p < 0.05) for group 1 at all time points measured after baseline. In groups 2, 3, and 4, serum concentrations of drug fell below the limit of detection (1.5 ng mL^–1) by 24 hours. Serum concentrations after 0.1 mg kg^–1of STDOx were 11.1 ± 3.6 ng mL^–1at 4 hours, which is the recommended time for redosing and presumably reflects the lower end of a therapeutic serum concentration. Serum concentrations were comparable after 1.0 mg kg^–1 of LEOx (10.5 ± 2.4 ng mL^–1) 48 hours after administration. These results suggest that liposomal oxymorphone may provide therapeutic serum concentrations of drug for 2 days after a single subcutaneous administration without undue sedation or other deleterious effects in healthy dogs. Further studies are warranted to assess analgesic efficacy and pharmacokinetics of lipsomal oxymorphone in dogs.  相似文献   

Salmonella monitoring programs in Australian feed mills: a retrospective analysis     

EM Parker  LJ Edwards  DF Mollenkopf  GA Ballash  TE Wittum  AJ Parker 《Australian veterinary journal》2019,97(9):336-342

The availability of safe, commercially prepared stock feed for production animals is an important step in ensuring animal health and welfare and the safety of food animal products for human consumption. Animal feed quality assurance programs include microbiological monitoring of raw materials, mill equipment and finished feed. Over a period of 16 years, 23,963 samples for Salmonella culture and serotyping were collected from 22 stock feed mills. A multivariable generalized linear mixed model (GLMM) was used to identify mill and sample type factors that increase the odds of detecting Salmonella. The odds of detecting a Salmonella positive sample was greatest in samples from raw materials and in mills that processed restricted animal material (RAM). The percentage of positive samples ranged from 7.2% in 2003 to 2.8% in 2017. Of the 1,069 positive samples, 976 were serotyped with 61 different Salmonella serotypes isolated. The serotype most frequently isolated from raw materials was S. Agona, (n = 108) whilst S. Anatum was the serotype most frequently isolated from equipment and finished feed (n = 156). The diversity of Salmonella serotypes differed between mills and different stages of the production line. Microbiological monitoring in the commercial preparation of animal feed in Australian stock feed mills guides the implementation of quality control measures and risk mitigation strategies thereby reducing the prevalence and diversity of potentially zoonotic bacteria such as Salmonella, enhancing food safety for both animal and consumer.  相似文献   

Transmission studies of Hendra virus (equine morbilli-virus) in fruit bats, horses and cats     

MM WILLIAMSON  PT HOOPER  PW SELLECK  LJ GLEESON  PW DANIELS  HA WESTBURY  PK MURRAY 《Australian veterinary journal》1998,76(12):813-818

Objective To determine the infectivity and transmissibility of Hendra virus (HeV). Design A disease transmission study using fruit bats, horses and cats. Procedure Eight grey-headed fruit bats (Pteropus poliocephalus) were inoculated and housed in contact with three uninfected bats and two uninfected horses. In a second exper iment, four horses were inoculated by subcutaneous injection and intranasal inoculation and housed in contact with three uninfected horses and six uninfected cats. In a third experi ment, 12 cats were inoculated and housed in contact with three uninfected horses. Two surviving horses were inoculated at the conclusion of the third experiment: the first orally and the second by nasal swabbing. All animals were necropsied and examined by gross and microscopic pathological methods, immunoperoxidase to detect viral antigen in formalin-fixed tissues, virus isolation was attempted on tissues and SNT and ELISA methods were used to detect HeV-specific antibody. Results Clinical disease was not observed in the fruit bats, although six of eight inoculated bats developed antibody against HeV, and two of six developed vascular lesions which contained viral antigen. The in-contact bats and horses did not seroconvert. Three of four horses that were inoculated devel oped acute disease, but in-contact horses and cats were not infected. In the third experiment, one of three in-contact horses contracted disease. At the time of necropsy, high titres of HeV were detected in the kidneys of six acutely infected horses, in the urine of four horses and the mouth of two, but not in the nasal cavities or tracheas. Conclusions Grey-headed fruit bats seroconvert and develop subclinical disease when inoculated with HeV. Horses can be infected by oronasal routes and can excrete HeV in urine and saliva. It is possible to transmit HeV from cats to horses. Transmission from P poliocephalus t o horses could not be proven and neither could transmission from horses to horses or horses to cats. Under the experimental conditions of the study the virus is not highly contagious.  相似文献   

Spatial stability of Avena sterilis ssp. ludoviciana populations under annual applications of low rates of imazamethabenz     

J Barroso  C Fernàndez-Quintanilla  D Ruiz  P Hernaiz  & LJ Rew† 《Weed Research》2004,44(3):178-186

Long‐term experiments were conducted in two winter barley fields in central Spain to determine the spatial stability of Avena sterilis ssp. ludoviciana populations under annual applications of low rates of imazamethabenz herbicide. Weed density was sampled every year (over 5 years in the first field and over 3 years in the second) on the same grid locations prior to herbicide application. Although weed patches were stable in their location, weed density decreased in most of the years. In the first field, the populations decreased exponentially over the 5‐year period. The rates of population decline were dependent on the initial density of the population, being higher for the central core of the patches and lower for the low‐density areas. Under the conditions present in this experiment, it was possible to reduce heavy weed patches (up to 1200 seedlings m^?2) down to relatively safe levels (18 seedlings m^?2) in a period of 3 years using a density‐specific control programme, applying low rates of herbicides when weed densities were below a given level (1000 seedlings m^?2). However, under adverse environmental conditions, half rates of the herbicide failed to control the weed populations adequately. The stability of the location of patches of A. sterilis ssp. ludoviciana suggest that weed seedling distributions mapped in one year are good predictors of future seedling distributions. However, the actual densities established each year will depend on the control level achieved the previous year and the climatic conditions present during the establishment period.  相似文献   

Vkorc1 sequencing suggests anticoagulant resistance in rats in New Zealand          下载免费PDF全文

Phil E Cowan  Dianne M Gleeson  Robyn LJ Howitt  Ana Ramón‐Laca  Alexandra Esther  Hans‐Joachim Pelz 《Pest management science》2017,73(1):262-266

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Quantum statistical corrections to dynamic nuclear magnetic resonance     

LJ Mueller  DP Weitekamp 《Science (New York, N.Y.)》1999,283(5398):61-65

A quantum statistical treatment of the chemical exchange between molecular eigenstates or conformations revealed previously unsuspected dynamic terms in the spin Hamiltonian operator that describes fast exchange. These terms resulted from the effect of nuclear spin on rotational and vibrational relaxation. With the traditional theory, an interpretation of new carbon-13 nuclear magnetic resonance measurements of the chemical shift of methylcyclohexane in solution showed fast-exchange equilibrium constants that were inconsistent with the slow-exchange free-energy difference and were spread over a range of 30 percent for the various carbon-13 positions. Modeling of the new terms indicated that they have the correct magnitude and temperature dependence to reconcile these inconsistencies.  相似文献   

Unique presentation of normolipaemic cutaneous xanthoma in a cat     

PA Ravens  LJ Vogelnest  SA Piripi 《Australian veterinary journal》2013,91(11):460-463

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Liposome-encapsulated oxymorphone prevents hyperalgesia for 7 days in a rat model of neuropathic pain     

LJ  Smith  L Krugner-Higby  M Clark  A Wendland  TD Heath 《Veterinary anaesthesia and analgesia》2003,30(2):115-116

A delayed‐release formulation of liposome‐encapsulated oxymorphone (LEO) was produced using a novel dehydration–rehydration technique. Preparations were standardized spectrophotometrically against a known concentration of the drug. The purpose of this study was to test the analgesic properties of LEO in a rat model of neuropathic pain. Sprague–Dawley rats were divided into control (non‐neuropathic) and test (neuropathic) groups. Control and test groups were administered one SC injection of (i) vehicle liposomes (negative control treatment); (ii) liposome‐encapsulated morphine, 2.8 mg kg^?1 (positive control treatment); or (iii) LEO, 1.2 mg kg^?1. All treatments were administered after baseline thermal withdrawal latencies (TWL) were determined (9.2 ± 0.39 seconds (mean ± SEM)). Test groups then underwent sciatic ligation to induce neuropathic pain. TWL were determined in all six groups (n = 8) daily for 1 week. In a separate group of age‐matched rats, blood (0.3 mL from the jugular vein) and urine (1–2 mL via metabolism cages) were collected daily for 7 days after administration of LEO (1.2 mg kg^?1). TWL did not change in the control rats given liposome‐encapsulated sucrose or morphine. There was a small increase (p = 0.04) in TWL in control rats given LEO, likely as a result of the relatively higher dose of oxymorphone compared with morphine based on receptor affinity. TWL in test rats given blank liposomes decreased significantly (p < 0.001) by day 4 (7.1 ± 0.5 seconds), with a maximal decrease by day 7 (5.1 ± 0.36 seconds), indicating development of full hyperalgesia. In contrast, rats given liposome‐encapsulated morphine or oxymorphone had no change in TWL at day 4, indicating that these preparations prevented hyperalgesia after a single injection. This treatment effect persisted through day 7. Serum concentrations of oxymorphone after a single injection of LEO peaked at 4 hours (6.8 ± 0.82 ng mL^?1) and were detectable through day 4 (0.98 ± 0.003 ng mL^?1), while urine concentrations of drug were detectable through day 7. This result suggests that oxymorphone metabolites might have been responsible for the protracted analgesic response. The encapsulation efficiency of oxymorphone using this novel technique was approximately 96%. In conclusion, liposome encapsulation of oxymorphone proved to be an efficient mechanism to provide a delayed‐release formulation of this opioid. This single dose of subcutaneously administered liposome‐encapsulated oxymorphone was effective in preventing hyperalgesia for 7 days in this animal model of neuropathic pain.  相似文献   

24-Hour Secretion Patterns of Plasma Oestradiol 17β in Pony Mares in Late Gestation     

LJ O'Donnell  BR Sheerin  JM Hendry  MJ Thatcher  WW Thatcher  MM LeBlanc 《Reproduction in domestic animals》2003,38(3):233-235

The mare exhibits nocturnal uterine contractions in the last 6 days of gestation. It is hypothesized that estradiol 17β (O17β) may be associated with the nightly increase in uterine contractions. The 24‐h secretion pattern of plasma O17β was measured in 3 pony mares in late gestation to identify changes in release as the mare neared parturition. Blood was collected weekly at 08:00 hours beginning on day 240 and every third day from day 330 until delivery. Serial blood samples were collected from each mare every 30‐min for 24‐h beginning on gestation day 310 and every sixth day thereafter until parturition. Concentrations of O17β were elevated at night with lowest concentrations occurring directly before sunset (p < 0.01). The natural log of the variance was increased at sunset (p < 0.01) and was decreased during the 6‐h period immediately after sunrise. This pattern was especially evident in the 6 days that preceded parturition. The contrast between nocturnal and daytime concentrations of O17β in the last 6 days of gestation may contribute to night‐time delivery in the mare.  相似文献   

Antimicrobial susceptibility of bacteria isolated from neonatal foal samples submitted to a New Zealand veterinary pathology laboratory (2004 to 2013)     

LJ Toombs-Ruane  CB Riley  AT Kendall  KE Hill  J Benschop  SM Rosanowski 《New Zealand veterinary journal》2016,64(2):107-111

AIMS: To describe antimicrobial susceptibility, and identify antimicrobial resistance (AMR), in bacteria isolated from New Zealand foals.

METHODS: A database search was performed of submissions to a veterinary pathology laboratory between April 2004 and December 2013 for bacterial culture of samples from foals <3 weeks of age. Culture and susceptibility results were compiled with demographic information. Susceptibility results were as defined for the Kirby-Bauer disk diffusion susceptibility test based on Clinical Laboratory Standards Institute guidelines. Multi-drug resistance (MDR) was defined as non-susceptibility to ≥3 of a panel of antimicrobials (ceftiofur, enrofloxaxin, gentamicin, penicillin, tetracycline, trimethoprim-sulfonamide); penicillin susceptibility was not included for Gram-negative isolates.

RESULTS: Submissions from 102 foals were examined, and 127 bacterial isolates were cultured from 64 (63%) foals. Of the 127 isolates, 32 (25%) were Streptococcus spp., 30 (24%) were Staphylococcus spp., 12 (10%) were Enterococcus spp. and 26 (21%) were Escherichia coli. Of 83 Gram-positive isolates, 57 (69%) were susceptible to penicillin. Over all isolates, 92/126 (73%) were susceptible to gentamicin and 117/126 (93%) to enrofloxacin; 62/82 (76%) of Gram-positive, and 22/42 (52%) of Gram-negative bacteria were susceptible to ceftiofur; 53/81 (65%) of Gram-positive, and 23/44 (52%) of Gram-negative bacteria were susceptible to tetracycline; 59/82 (72%) of Gram-positive, and 23/44 (43%) of Gram-negative bacteria were susceptible to trimethoprim-sulfonamide. Of 126 isolates, 33 (26%) had MDR; >1 isolate with MDR was cultured from 24/64 (38%) foals, and ≥2 isolates with MDR were recovered from 8/64 (13%) foals.

CONCLUSIONS: Multi-drug resistance, including resistance to commonly used antimicrobials, was found in bacterial isolates from foals in New Zealand.

CLINICAL RELEVANCE: The results of this study are of concern from a treatment perspective as they indicate a potential for antimicrobial treatment failure. For future surveillance of AMR and the creation of national guidelines, it is important to record more data on samples submitted for bacterial culture.  相似文献