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排序方式: 共有405条查询结果,搜索用时 62 毫秒
91.
Skov MN Spencer AG Hald B Petersen L Nauerby B Carstensen B Madsen M 《Avian diseases》2004,48(1):9-18
We evaluated the role of beetles infesting broiler chicken rearing facilities as potential reservoirs for Salmonella enterica infections between successive broiler flocks. In addition, their role as potential reservoirs for thermophilic Campylobacter spp. was also investigated. Fourteen broiler houses located at 11 different farms were included in the study. The houses were nonrandomly selected on the basis of their salmonella status; nine were persistently contaminated with salmonella whereas five were salmonella negative. For each broiler house, two consecutive broiler flocks (i.e., 28 broiler flocks in all) as well as beetles collected during both rotations of production and in the empty period (after cleaning and disinfection) between these flocks were monitored for the presence of salmonella. Examinations for the presence of campylobacter in the same sample materials were also performed. Beetles sampled during production were positive for salmonella or campylobacter or both. Furthermore, in one house, the occurrence of Salmonella indiana in two consecutive broiler flocks coincided with the presence of S. indiana-contaminated beetles in the empty period between the flocks. The genotype of the identified S. indiana was in all cases identical when analyzed by pulsed-field gel electrophoresis. However, our results also suggest that salmonella from beetles may not always be transmitted to the chickens and that beetles living in contaminated houses can remain free of infection. All cases of campylobacter-positive beetle samples were detected in connection with a positive chicken flock; in no case was campylobacter isolated from beetles taken from the empty period between rotations. Four beetle species were identified during this study. Alphitobius diaperinus was found in all houses and was relatively abundant in most. Typhaea stercorea and Ahasverus advena were found in eight and nine houses, respectively, and were abundant in most of these. Carcinops pumilio was found in small numbers in eight houses. No other insect species was identified. These investigations have shown that beetles in broiler houses infrequently are positive for salmonella. However, transmission of S. indiana between two consecutive broiler flocks can coincide with the presence of salmonella-contaminated beetles in the empty period, indicating that the beetles were the reservoir of S. indiana between the two flocks. Concerning campylobacter, the results suggest that beetles do not play a significant role as a reservoir of campylobacter from one rotation to the next. 相似文献
92.
A cross-sectional study was conducted with 617 finishing pigs aged 10–25 weeks in 11 commercial herds of different health statuses as defined by the Danish monitoring program for specific-pathogen-free (SPF) herds. A standard clinical examination was performed and a blood sample was obtained from each pig for determination of haptoglobin concentration in serum.
Pigs aged 10–14, 15–19 and 20–25 weeks in conventional herds had higher haptoglobin concentrations than high-health SPF (SPF-x) pigs of the same age. There was no significant difference between SPF-x pigs of different ages. Conventional pigs aged 15–19 and 20–25 weeks had higher haptoglobin concentrations than conventional pigs aged 10–14 weeks. Herd influenced the haptoglobin concentration. Lame pigs and pigs with tail or ear bite had elevated haptoglobin concentrations. No significant effect of respiratory symptoms or umbilical hernia was found. 相似文献
93.
94.
Petersen SA Sturges BK Dickinson PJ Pollard RE Kass PH Kent M Vernau KM Lecouteur RA Higgins RJ 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2008,22(4):946-953
BACKGROUND: Meningioma is the most common primary intraspinal nervous system tumor in dogs. Clinical findings, clinicopathologic data, and treatment of these tumors have been reported sporadically, but little information is available regarding cerebrospinal fluid (CSF) analysis, histologic tumor grade, or efficacy of radiation therapy as an adjunct to cytoreductive surgery. ANIMALS: Dogs with histologically confirmed intraspinal meningiomas (n = 34). METHODS: A retrospective study of dogs with intraspinal meningiomas between 1984 and 2006 was carried out. Signalment, historical information, physical examination, clinicopathologic data, radiation therapy protocols, surgery reports, and all available images were reviewed. All tumors were histologically classified and graded as defined by the international World Health Organization classification scheme for central nervous system tumors. RESULTS: Intraspinal mengiomas in dogs are most common in the cervical spinal cord but can be found throughout the neuraxis. Location is correlated with histologic grade, with grade I tumors more likely to be in the cervical region than grade II tumors. Myelography generally shows an intradural extramedullary compressive lesion. On magnetic resonance imaging, the masses are strongly and uniformly contrast enhancing and a dural tail often is present. CSF analysis usually shows increased protein concentration with mild to moderate mixed pleocytosis. Surgical resection is an effective means of improving neurologic status, and adjunctive radiation therapy may lead to an improved outcome. CONCLUSIONS AND CLINICAL IMPORTANCE: Biopsy is necessary for definitive diagnosis, but imaging and CSF analysis can suggest a diagnosis of meningioma. Treatment of meningiomas with surgery and radiation therapy can result in a fair to excellent prognosis. 相似文献
95.
Iben Lykke Petersen Hans Christian Bruun Hansen Jens Christian Sørensen 《Pesticide biochemistry and physiology》2007,89(3):220-229
Metabolic effects in rapeseed (Brassica napus L.) seedlings after root exposure to sublethal concentrations of glyphosate were examined in order to evaluate the possibilities of using a response pattern in plants as a measure of exposure to glyphosate through the growth media, more sensitive than the well-known biomarker shikimate. Rapeseed seedlings were grown in hydroponic nutrient solutions containing varying sublethal concentrations of glyphosate (1-50 μM). After 9 days of glyphosate exposure, the shoots of the seedlings were analysed with respect to the effects on selected metabolites downstream from the primary affected metabolite shikimate, which accumulated linearly in response to glyphosate exposure (from 0 to ∼126 μmol/g DW). The selected metabolites analysed, comprising the free amino acids, and the glucosinolates derived therefrom, showed complex patterns in response to glyphosate exposure. Most noteworthy was though that they responded at the lowest concentrations of exposure to glyphosate (1 μM), where no visual effects, decrease in shoot DW or shikimate could be detected, indicating that a biomarker response more sensitive than that of shikimate can be established for plants exposed to glyphosate. 相似文献
96.
The effusive form of feline infectious peritonitis (FIP) was reproduced by injecting 12- to 16-week-old kittens intraperitoneally with a cell-free inoculum derived from the tissues of infected cats. The kittens used for the study were either positive for FIP virus-reacting antibodies before inoculation or they were seronegative. Seropositive kittens were obtained from a cattery where the natural infection was enzootic, and seronegative kittens were obtained from a specific-pathogen-free cattery. Only about half the kittens that were seronegative before inoculation developed disease or serum antibodies to the tissue-derived virus. Seronegative kittens that developed disease showed no signs of illness until 8 to 10 days after inoculation, and they lived for 7 to 14 days after clinical signs appeared. The onset of clinical disease coincided with the appearance of serum antibodies. In contrast, all of the seropositive kittens became ill within 36 to 48 hours after inoculation, and died within 5 to 7 days. If seronegative kittens were treated with immune serum or immunoglobulin (Ig)G, they developed disease with the same frequency, acuteness, and severity as seropositive kittens. Foci of hepatitis and serositis in seropositive kittens contained viral antigen, IgG bound to antigen, and complement. Serum complement activity also decreased several days before death in seropositive kittens inoculated with tissue-derived FIP virus. The temporal relationship of clinical disease and the appearance of serum antibodies, the more acute and severe nature of the disease produced in seropositive kittens, and the presence of antibody and complement in the lesions indicated that effusive FIP is immunologically mediated. 相似文献
97.
Ranjith Jayaweera Richard Petersen Pavel Smejtek 《Pesticide biochemistry and physiology》1982,18(2):197-204
Pentachlorophenol (PCP) decreases the rate of carbon assimilation in the alga Selenastrum capricornutum. In parallel with the reduction of carbon assimilation in this alga there is a decrease of electrical resistance of lipid membranes and development of negative membrane surface charge. The experimental results suggest that PCP toxicity to algae is due to adsorption of negatively charged PCP ions at the membrane surface that act as carriers of hydrogen ion across the membrane. This protonophoretic action of PCP causes the decrease of membrane electrical resistance and the dissipation of hydrogen ion electrochemical potential gradients across cellular and subcellular membranes, which reduces the ability of algae to assimilate carbon. 相似文献
98.
99.
Einer-Jensen N Khorooshi MH Petersen MB Svendsen P 《Acta veterinaria Scandinavica》2001,42(4):459-464
Local cooling of the brain by the respiratory air is found in many animal species. The mechanism is based on cooling of the nasal vein blood and heat transfer in the cavernous sinus/carotid artery complex and is therefore not active in anaesthetised, intubated animals. The present experiment was made to investigate the effects of oxygen flushing of the nasal cavities in such animals. Nine anaesthetised, intubated male pigs were used. The temperatures in the third ventricle and rectum were measured continuously. Oxygen was infused into the nasal cavities during 10 min periods interrupted by 10 min without flow. The nasal oxygen flow constantly induced a rapid, reversible and flow dependant decrease in brain temperature: 0.25 degree C +/- 0.04, (n = 2) (mean +/- SD, n) at < 4 l/min; 1.35 degrees C +/- 0.78, (n = 20) at 4-6 l/min; and 1.44 degrees C +/- 0.62, (n = 6) at > 6 l/min. The ventricle temperature decreased 0.59 degree C +/- 0.23, (n = 8) when the animals were transferred to spontaneous respiration and the tracheal tube removed. It may be possible to protect the brain in intubated animals and humans from heat-induced damages by establishment of nasal flushing. 相似文献
100.
The body's early defence in response to trauma, inflammation or infection, the acute phase response, is a complex set of systemic reactions seen shortly after exposure to a triggering event. One of the many components is an acute phase protein response in which increased hepatic synthesis leads to increased serum concentration of positive acute phase proteins. The serum concentration of these acute phase proteins returns to base levels when the triggering factor is no longer present. This paper provides a review of the acute phase proteins haptoglobin, C-reactive protein and serum amyloid A and their possible use as non-specific indicators of health in large animal veterinary medicine such as in the health status surveillance of pigs at the herd level, for the detection of mastitis in dairy cattle and for the prognosis of respiratory diseases in horses. 相似文献