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91.
A yearling Thoroughbred colt was admitted to the University of Florida College of Veterinary Medicine with severe, progressive lameness of the left forelimb. A centrally located expansile lytic lesion involving approximately 40% of the distal phalanx with a large associated vascular channel was identified by radiography. Increased vascular phase pooling, increased soft tissue phase uptake, and a photopenic area on bone phase images corresponding to the lytic lesion within the left distal phalanx were identified by vascular, soft tissue, and bone phases of a three phase bone scan, respectively. Contrast medium accumulation and disappearance in dilated vessels within the lesion was apparent angiographically. The colt was euthanized and the histologic diagnosis was hemangioma of the distal phalanx with a pathologic fracture.  相似文献   
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Cholesterol utilized for steroid synthesis by ovarian tissue may be derived from de novo synthesis or cellular uptake of lipoprotein cholesterol. The majority of blood cholesterol is transported by either low (LDL) or high (HDL) density lipoproteins, depending on the animal species. Prior to vascularization, only HDL are in follicular fluid and contribute sterol to granulosa cells because other lipoproteins are unable to transverse the basement membrane due to their molecular masses. Following vascularization, both LDL and HDL bathe luteal cells. Most species preferentially use LDL cholesterol as a precursor for ovarian steroid synthesis. The LDL uptake by ovarian tissue occurs by receptor-mediated endocytosis. The receptor recognizes apolipoprotein B of LDL and apolipoprotein E found on some, but not all, HDL. Within a species, a positive relationship may exist between HDL apolipoprotein E content and importance of HDL cholesterol as a precursor for steroidogenesis. A "HDL pathway" exists for uptake of sterol from HDL void of apolipoprotein E. The HDL receptor exhibits broad binding specificity. Unlike LDL, the HDL particle is not internalized, and cholesterol preferentially is taken up relative to other HDL constituents. In most species, lipoproteins, rather than de novo synthesis from acetate, contribute the majority of cholesterol used for steroid production. Trophic hormones increase lipoprotein binding, internalization, degradation and conversion of lipoprotein-derived sterol to steroids, effects that are mediate through cyclic adenosine monophosphate. Knowledge recently acquired regarding lipoprotein sterol utilization by the ovary may be useful in developing nutritional, pharmacological or endocrine manipulations that may positively affect cholesterol clearance by the ovary, steroidogenesis and reproductive performance.  相似文献   
93.
A Yorkshire terrier and a Chihuahua were referred for acute onset, generalized tonic‐clonic seizures and were suspected to have meningoencephalitis based on magnetic resonance (MR) imaging findings. Brain lesions appeared hyperintense with T2‐weighted imaging and hypointense with T1‐weighted imaging, and were characteristic of necrotizing meningoencephalitis. Both dogs were diagnosed with necrotizing meningoencephalitis based on pathologic findings. Fluorine‐18 fluorodeoxyglucose positron emission tomography (FDG‐PET) was performed on both animals before euthanasia with the permission of the owner. In FDG‐PET images, these lesions seen in MR images were characterized by multifocal or diffuse hypometabolism. Our FDG‐PET results provided evidence of glucose hypometabolism in areas of necrosis and cavitation associated with necrotizing meningoencephalitis. FDG‐PET has the potential to provide valuable diagnostic information in dogs with suspected necrotizing encephalitis.  相似文献   
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Despite ongoing public health messages about the risks associated with bat contact, the number of potential exposures to Australian bat lyssavirus (ABLV) due to intentional handling by members of the general public in Queensland has remained high. We sought to better understand the reasons for intentional handling among these members of the public who reported their potential exposure to inform future public health messages. We interviewed adults who resided in a defined geographic area in South East Queensland and notified potential exposure to ABLV due to intentional handling of bats by telephone between 1 January 2012 and 31 December 2013. The participation rate was 54%. Adults who reported they had intentionally handled bats in South East Queensland indicated high levels of knowledge and perception of a moderately high risk associated with bats with overall low intentions to handle bats in the future. However, substantial proportions of people would attempt to handle bats again in some circumstances, particularly to protect their children or pets. Fifty‐two percent indicated that they would handle a bat if a child was about to pick up or touch a live bat, and 49% would intervene if a pet was interacting with a bat. Future public health communications should recognize the situations in which even people with highrisk perceptions of bats will attempt to handle them. Public health messages currently focus on avoidance of bats in all circumstances and recommend calling in a trained vaccinated handler, but messaging directed at adults for circumstances where children or pets may be potentially exposed should provide safe immediate management options.  相似文献   
96.
Strong regularities in world wide web surfing   总被引:5,自引:0,他引:5  
One of the most common modes of accessing information in the World Wide Web is surfing from one document to another along hyperlinks. Several large empirical studies have revealed common patterns of surfing behavior. A model that assumes that users make a sequence of decisions to proceed to another page, continuing as long as the value of the current page exceeds some threshold, yields the probability distribution for the number of pages that a user visits within a given Web site. This model was verified by comparing its predictions with detailed measurements of surfing patterns. The model also explains the observed Zipf-like distributions in page hits observed at Web sites.  相似文献   
97.
ABSTRACT The population structure of Guignardia citricarpa sensu lato (anamorph: Phyllosticta citricarpa), a fungus of which strains pathogenic to citrus are subject to phytosanitary legislation in the European Union and the United States, was investigated. Internal transcribed spacer sequences revealed two phylogenetically distinct groups in G. citricarpa. This distinction was supported by amplified fragment length polymorphism analysis that also supported the exclusion of two isolates that had apparently been misclassified as G. citricarpa. On cherry decoction agar, but not on other media, growth rates of group I isolates were lower than those of group II isolates. Conidial dimensions were similar, but group I isolates formed conidia with barely visible mucoid sheaths, whereas those of group II formed conidia with thick sheaths. Cultures of isolates belonging to group I produced rare infertile perithecia, whereas fertile perithecia were formed by most isolates of group II. Colonies of isolates belonging to group I were less dark than those of group II, with a wider translucent outer zone and a lobate rather than entire margin. On oatmeal agar, exclusively group I isolates formed a yellow pigment. Group I harbored strains from citrus fruits with classical black spot lesions (1 to 10 mm in diameter) usually containing pycnidia. Group II harbored endophytic strains from a wide range of host species, as well as strains from symptomless citrus fruits or fruits with minute spots (<2-mm diameter) without pycnidia. These observations support the historic distinction between slowly growing pathogenic isolates and morphologically similar fast-growing, nonpathogenic isolates of G. citricarpa. The latter proved to belong to G. mangiferae (P. capitalensis), a ubiquitous endophyte of woody plants with numerous probable synonyms including G. endophyllicola, G. psidii, P. anacardiacearum, and P. theacearum. G. mangiferae occurs in the European Union and the United States on many host species including citrus, and does not cause symptoms of citrus black spot, justifying its exclusion from quarantine measures.  相似文献   
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Objective To evaluate disposition of a single dose of butorphanol in goats after intravenous (IV) and intramuscular (IM) administration and to relate behavioral changes after butorphanol administration with plasma concentrations. Design Randomized experimental study. Animals Six healthy 3‐year‐old neutered goats (one male and five female) weighing 46.5 ± 10.5 kg (mean ± D). Methods Goats were given IV and IM butorphanol (0.1 mg kg?1) using a randomized cross‐over design with a 1‐week interval between treatments. Heparinized blood samples were collected at fixed intervals for subsequent determination of plasma butorphanol concentrations using an enzyme linked immunosorbent assay (ELISA). Pharmacokinetic values (volume of distribution at steady state [VdSS], systemic clearance [ClTB], extrapolated peak plasma concentration [C0] or estimated peak plasma concentration [CMAX], time to estimated peak plasma concentration [TMAX], distribution and elimination half‐lives [t1/2], and bioavailability) were calculated. Behavior was subjectively scored. A two‐tailed paired t‐test was used to compare the elimination half‐lives after IV and IM administration. Behavioral scores are reported as median (range). A Friedman Rank Sums test adjusted for ties was used to analyze the behavioral scores. A logit model was used to determine the effect of time and concentration on behavior. A value of p < 0.05 was considered significant. Results Volume of distribution at steady state after IV administration of butorphanol was 1.27 ± 0.73 L kg?1, and ClTB was 0.0096 ± 0.0024 L kg?1 minute?1. Extrapolated C0 of butorphanol after IV administration was 146.5 ± 49.8 ng mL?1. Estimated CMAX after IM administration of butorphanol was 54.98 ± 14.60 ng mL?1, and TMAX was 16.2 ± 5.2 minutes; bioavailability was 82 ± 41%. Elimination half‐life of butorphanol was 1.87 ± 1.49 and 2.75 ± 1.93 hours for IV and IM administration, respectively. Goats became hyperactive after butorphanol administration within the first 5 minutes after administration. Behavioral scores for goats were significantly different from baseline at 15 minutes after IV administration and at 15 and 30 minutes after IM administration. Both time and plasma butorphanol concentration were predictors of behavior. Behavioral scores of all goats had returned to baseline by 120 minutes after IV administration and by 240 minutes after IM administration. Conclusions and Clinical Relevance The dose of butorphanol (0.1 mg kg?1, IV or IM) being used clinically to treat postoperative pain in goats has an elimination half‐life of 1.87 and 2.75 hours, respectively. Nonpainful goats become transiently excited after IV and IM administration of butorphanol. Clinical trials to validate the efficacy of butorphanol as an analgesic in goats are needed.  相似文献   
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