Control panels of meat juice samples for a Salmonella enzyme-linked immunosorbent assay.     

Hanne Bak  Vibeke S?rensen 《Journal of veterinary diagnostic investigation》2006,18(4):355-361

In the Danish pig production system, an indirect enzyme-linked immunosorbent assay (ELISA) for detection of antibodies in meat juice is used for Salmonella surveillance. Quality control (QC) of this ELISA was previously based on repeated testing of control serum samples. The purpose of the study reported here was to collect, characterize, and implement a panel of meat juice pools for supplemental internal QC. Muscle samples for extraction of meat juice were collected from slaughter pigs of 5 herds infected with Salmonella spp. and from 4 herds without Salmonella infection. A QC panel with 39 pools of meat juice, yielding ELISA optical density (OD) values covering the full range of expected OD values, was prepared and tested repeatedly to determine mean and SD OD values. Each pool was tested twice on each microtitration plate, and the results were used to determine limits for validity of future tests. This QC panel was included as an internal QC to be tested every month. Besides the QC panel, 2 panels containing 100 samples of meat juice with OD above the positive cut-off value and 100 samples with OD below that value were prepared for quarterly control of the diagnostic sensitivity (DSe) and the diagnostic specificity (DSp) of the ELISA. The inclusion of these panels in the QC system will provide information about drifts in DSe and DSp of the test. The procedures described here can be applied to other tests where meat juice samples are used for testing.  相似文献   

Isolation of putative probionts from cod rearing environment     

Lauzon HL  Gudmundsdottir S  Pedersen MH  Budde BB  Gudmundsdottir BK 《Veterinary microbiology》2008,132(3-4):328-339

Survival problems are encountered at early stages of intensive fish rearing and antibiotics are widely used to remedy the situation. Probiotics may provide a potential alternative method to protect larvae from opportunistic and pathogenic bacteria and promote a balanced environment. This study was designed to search for new probiotics to target this critical period in cod rearing. Potential probionts were selected from the natural microbiota of cod aquacultural environment. The selection was based on several criteria: pathogen inhibition potential, growth characteristics, strain identification, metabolite production and adhesion to fish cell lines. Our study demonstrated that 14% of screened bacteria (n=188) had antagonistic properties towards fish pathogens. The majority of these isolates were Gram-positive (81%), belonging to Firmicutes (69.2%) and Actinobacteria (11.5%) phyla based on 16S rRNA gene sequencing. Only 6 (3.2%) of 188 isolates could inhibit all three pathogens tested: Vibrio anguillarum, Aeromonas salmonicida subsp. achromogenes and Vibrio salmonicida. Differences observed in activity intensity and spectrum among inhibitory isolates emphasise the need to develop probiotic mixtures for efficient prophylactic methods. Comparison of growth behaviour of inhibitory isolates and pathogens at cod rearing temperatures, metabolite production and adhesion capacity were considered for final probiont selection. Four promising isolates that could be used as a mixed supplement to rearing water were identified as putative probiotic bacteria. This study emphasises the importance and potential of lactic acid bacteria in aquaculture.  相似文献   

Synthesis and insecticidal activities of unsymmetrical bis-arylalkyl ketones. A new structural concept in pyrethroids     

Axel Svendsen  Lars-Erik K. Pedersen  Per D. Klemmensen 《Pest management science》1986,17(2):93-102

Seventeen unsymmetrical bis-arylalkyl ketones were synthesised and their insecticidal activities against Musca domestica, Locusta migratoria, Drosophila melanogaster, Dysdercus cingulatus, Aedes aegypti and Tetranychus urticae were tested. The synergistic effect of piperonyl butoxide on the activities of some of the new ketopyrethroids against Musca domestica was also determined. Several structural variations, including substituent exchange in the aryl moieties, the position of the ketone function and increase or decrease of the length of the carbon chain connecting the two aryl moieties, were made in order to examine the structure-activity relationship. All biological activities were compared with the activity of the ether pyrethroid 2-(4-ethoxyphenyl)-2-methylpropyl 3-phenoxybenzyl ether (MTI-500).  相似文献   

Effect of cumulus cells and sperm concentration on fertilization and development of pig oocytes          下载免费PDF全文

R Li  Y Liu  HS Pedersen  H Callesen 《Reproduction in domestic animals》2018,53(4):1009-1012

Effect of sperm concentrations and cumulus cells (CCs) on porcine IVF was re‐evaluated using current improved IVM and IVC system. Our results showed that both CCs and sperm concentration had significant effect on penetration rate, frequency of polyspermy and embryonic development. The best IVF results were obtained with oocytes with CCs fertilized with 0.5 × 10⁵ sperm/ml. Such an IVP system works on both sow and gilt oocytes.  相似文献   

Effects of trimethoprim–sulfadiazine and detomidine on the function of equine Kv11.1 channels in a two‐electrode voltage‐clamp (TEVC) oocyte model          下载免费PDF全文

D. S. Trachsel  M. A. Tejada  V. Groesfjeld Christensen  P. J. Pedersen  J. K. Kanters  R. Buhl  K. Calloe  D. A. Klaerke 《Journal of veterinary pharmacology and therapeutics》2018,41(4):536-545

The long QT syndrome (LQTS) is a channelopathy that can lead to severe arrhythmia and sudden cardiac death. Pharmacologically induced LQTS is caused by interaction between drugs and potassium channels, especially the K_v11.1 channel. Due to such interactions, numerous drugs have been withdrawn from the market or are administered with precautions in human medicine. However, some compounds, such as trimethoprim–sulfonamide combinations are still widely used in veterinarian medicine. Therefore, we investigate the effect of trimethoprim–sulfadiazine (TMS), trimethoprim, sulfadiazine, and detomidine on equine‐specific K_v11.1 channels. K_v11.1 channels cloned from equine hearts were heterologously expressed in Xenopus laevis oocytes, and whole cell currents were measured by two‐electrode voltage‐clamp before and after drug application. TMS blocked equine K_v11.1 current with an IC₅₀ of 3.74 mm (95% CI: 2.95–4.73 mm ) and affected the kinetics of activation and inactivation. Similar was found for trimethoprim but not for sulfadiazine, suggesting the effect is due to trimethoprim. Detomidine did not affect equine K_v11.1 current. Thus, equine K_v11.1 channels are also susceptible to pharmacological block, indicating that some drugs may have the potential to affect repolarization in horse. However, in vivo studies are needed to assess the potential risk of these drugs to induce equine LQTS.  相似文献   

Eastern equine encephalitis in 9 South American camelids     

Nolen-Walston R  Bedenice D  Rodriguez C  Rushton S  Bright A  Fecteau ME  Short D  Majdalany R  Tewari D  Pedersen D  Kiupel M  Maes R  Del Piero F 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2007,21(4):846-852

BACKGROUND: Eastern equine encephalitis (EEE) virus is a mosquito-borne togavirus (alphavirus) that causes severe (often fatal) encephalitis in many mammalian species, but it has not been reported previously in South American camelids. Hypothesis: South American camelids can become naturally infected with EEE virus and show encephalitic signs similar to those observed in other affected species. ANIMALS: Nine cases (8 alpacas and 1 llama, aged 3.5 weeks to 12 years) were identified; 4 of 9 were 510 weeks old. All cases were from the East Coast of the United States and presented in late summer and fall. METHODS: A retrospective study was performed to include confirmed cases of EEE in camelids in North America before 2006. RESULTS: Eight of nine (89%) camelids died or were euthanized in extremis, with the mean time to death of 2 days. Clinical signs were consistent with encephalitis and included fever, lethargy, ataxia, seizures, recumbency, torticollis, opisthotonus, and vestibular signs. No consistent hematologic abnormalities were identified, and cerebrospinal fluid contained an increased protein concentration in the single camelid analyzed. No successful therapy was identified. EEE was confirmed by alphavirus detection by using immunohistochemistry (IHC) and polymerase chain reaction (PCR) in the central nervous system (CNS) and by serology. Findings included polioencephalitis with lymphocytic perivascular cuffing; neutrophil infiltration; gliosis; neuron satellitosis; necrosis; and edema, with intracytoplasmic alphavirus within neurons and glial cells. No virus was detected in extraneural tissues. CONCLUSIONS AND CLINICAL IMPORTANCE: In endemic areas, EEE should be considered a differential diagnosis for young and adult camelids with CNS disease. Brain histopathology with indirect IHC or PCR is diagnostic.  相似文献   

Direct measurements of nitric oxide release in relation to expression of endothelial nitric oxide synthase in isolated porcine mitral valves     

Moesgaard SG  Olsen LH  Aasted B  Viuff BM  Pedersen LG  Pedersen HD  Harrison AP 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2007,54(3):156-160

The aim of this study was to measure the direct release of nitric oxide (NO) from the porcine mitral valve using a NO microelectrode. Furthermore, the expression and localization of endothelial nitric oxide synthase (eNOS) in the mitral valve was studied using immunohistochemistry, Western blotting and RT-PCR. Results show that bradykinin increases NO release from mitral valves (DeltaBradykinin: 33.71 +/- 10.41 nm NO, P < 0.001, n = 10), whereas N-nitro-l-arginine methyl esther (l-NAME) decreases NO release when compared with basal level (Deltal-NAME: 82.69 +/- 15.66 nm NO, P < 0.005, n = 4). Both protein and mRNA expression of eNOS in mitral valves and in isolated valvular endothelial cells suggest that the NO release is mainly associated with the mitral valve endothelium. It is concluded that direct NO release from porcine mitral valves coincides with eNOS expression. This study documents useful techniques for investigations into the role of local NO release in mitral valve diseases.  相似文献   

Models to quantify excretion of dry matter,nitrogen, phosphorus and carbon in growing pigs fed regional diets     

Henry JФrgensen  Trakarn Prapaspongsa  Van Thi Khanh Vu  Hanne Damgaard Poulsen 《畜牧与生物技术杂志(英文版)》2014,(2):199-207

Modern pig production contributes to many environmental problems that relate to manure, especially in areas with highly intensive production systems and in regions like Asia where the regulative control is not effective. Therefore, the objective of this study was to use three different pig diets varying in dietary protein, fibre and fat as representative for Danish （DK）, Thai （TH） and Vietnamese （VN） pig production to develop and evaluate different approaches to predict/calculate excretion from growing pigs in comparison with the experimentally determined values. Nine female growing pigs were used in a digestibility and balance experiment. Excretion of dry matter （DM）, nitrogen （N）, phosphorus （P） and carbon （C） of the experimental diets were determined. Due to the highest dietary fibre content, VN had the lowest digestibility of N, P and C （73, 49, and 73%, respectively） compared with the DK and TH pig diets. From the known diet composition using standard table values on chemical and nutrient digestibly, high accuracy （bias） and low variation was found and the results could be used for prediction on chemical composition and excretion in faeces and urine in growing pigs. Calculation based on standard values regarding nutrient retention in the pig body as used in the Danish manure normative system （DMNS） showed likewise to be quite useful for quantifying the total excretion of N and P. Overall, the results demonstrate that simple models that require cheap and normally available information on dietary nutrients can give useful information on nutrient excretion in growing pigs.  相似文献   

Estuarine predation on radiotagged wild and domesticated sea trout (Salmo trutta L.) smolts   总被引：2，自引：0，他引：2  

C. Dieperink  S. Pedersen  M. I. Pedersen 《Ecology of Freshwater Fish》2001,10(3):177-183

Abstract – Avian predation on emigrating wild and domesticated sea trout smolts was investigated in a fjord in the western Baltic Sea. In April 1997, 50 domesticated and 50 wild smolts were intraperitoneally tagged with radio-transmitters and released in a small coastal stream. Predation was recorded by signal interception in an estuarine breeding colony of cormorants and herons near the outlet of the stream. Of the 78 emigrating smolts, 51 (65%) were recorded as eaten. Predation rates were significantly higher among small than large smolts and significantly higher among domesticated smolts. The first 2 days after entering the sea, both wild and domesticated smolts suffered a severe daily predation rate (range 20–34%). The results support the hypothesis of a transient period immediately after exposure to full-strength sea water, where smolts experience an elevated risk of predation. A transient increase in postsmolt mortality may be found also in moderately saline environments (20–23 ppt).  相似文献   

Habitat selection of overwintering Calanus finmarchicus in the NE Norwegian Sea and shelf waters off Northern Norway in 2000–02     

Elisabeth Halvorsen  Kurt S. Tande  Are Edvardsen  Dag Slagstad  Ole Petter Pedersen 《Fisheries Oceanography》2003,12(4-5):339-351

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