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951.
OBJECTIVE: To evaluate L-selectin (CD62L) and Mac-1 (CD11b) expression at the surface of blood and milk neutrophils during the early inflammatory response to Escherichia coli-induced mastitis in cows. ANIMALS: 6 healthy Holstein heifers in early lactation. PROCEDURE: Blood and milk samples were collected before and after intramammary administration of 10(4) CFU's of E coli in the left mammary gland quarters. Bacterial counts and electrolyte concentrations in milk, rectal temperature, differential blood leukocyte counts, milk somatic cell counts, neutrophil viability, and the expression of CD62L and CD11b on blood and milk neutrophils were determined longitudinally. RESULTS: Bacteria grew during the first 6 hours after inoculation with a pronounced leukocytic influx. Coincident with neutrophil influx was an increase in CD62L+ and CD11b+ milk neutrophils, as well as an improved viability of milk neutrophils. The peak of the inflammatory reaction was reached approximately 12 hours after E coli inoculation. From that time forward, changes in CD62L and CD11b expression were opposed to each other, with a decrease in CD62L expression and an increase in CD11b expression on blood and milk neutrophils; the magnitude of the differences in CD62L and CD11b expression between blood and milk neutrophils decreased. Percentages of CD62L+ and CD11b+ milk neutrophils increased to percentages that were similar to blood neutrophils (ie, approx 92%). CONCLUSIONS AND CLINICAL RELEVANCE: The presence of adhesion molecules on a large percentage of milk neutrophils during the acute inflammatory response, together with the changes in receptor density, suggest a major role for CD62L and CD11b in neutrophil function during coliform mastitis.  相似文献   
952.
OBJECTIVE: To determine whether proinflammatory mediators and glucocorticoids affect CD62L(L-selectin) expression on peripheral blood neutrophils from cows in various stages of lactation. ANIMALS: 100 healthy dairy cows during early (13.1 +/- 0.79 days after parturition; n = 31), peak (58.7 +/- 1.64 days after parturition; 31), and mid (137.2 +/- 2.59 days after parturition; 38) lactation. PROCEDURE: In vitro effects of relevant proinflammatory mediators that are released in response to mastitis caused by gram-negative bacteria such as lipopolysaccharide (endotoxin), tumor necrosis factor-alpha, and platelet-activating factor (PAF) on CD62L expression on bovine neutrophils were assessed by flow cytometry. Influences of cortisol and dexamethasone on CD62L expression on bovine neutrophils were also investigated. RESULTS: Basal CD62L expression on neutrophils from cows during early, peak, and mid lactation were similar. Lipopolysaccharide and tumor necrosis factor-alpha had no effect on CD62L expression on neutrophils from cows at any stage of lactation. Conversely, PAF elicited a time- and dose-dependent, down regulatory effect on CD62L expression. However, no differential shedding of CD62L from neutrophils of cows at any stage of lactation were detected. In addition, no effects on CD62L expression on bovine neutrophils after whole blood incubation with cortisol or dexamethasone were observed. Incubation with glucocorticoids did not prevent the down regulatory effect of PAF on CD62L expression. CONCLUSIONS AND CLINICAL RELEVANCE: Comparable basal CD62L expression on bovine neutrophils and equal amounts of CD62L shedding from bovine neutrophils during all stages of lactation suggest that variations in CD62L density are not a likely cause of susceptibility of cows to coliform-induced mastitis during early lactation.  相似文献   
953.
Frick B  Richter D 《Science (New York, N.Y.)》1995,267(5206):1939-1945
Recent neutron scattering experiments on the microscopic dynamics of polymers below and above the glass transition temperature T(g) are reviewed. The results presented cover different dynamic processes appearing in glasses: local motions, vibrations, and different relaxation processes such as alpha- and beta-relaxation. For the alpha-relaxation, which occurs above T(g), it is possible to extend the time-temperature superposition principle, which is valid for polymers on a macroscopic scale, to the microscopic time scale. However, this principle is not applicable for temperatures approaching T(g). Below T(g), an inelastic excitation at a frequency of some hundred gigahertz (on the order of several wave numbers), the "boson peak," survives from a quasi-elastic overdamped scattering law at high temperatures. The connection between this boson peak and the fast dynamic process appearing near T(g) is discussed.  相似文献   
954.
A 6-year-old thoroughbred gelding was presented with a history of blepharospasm and opacity in the OS of 1 weeks' duration. Ophthalmic examination findings were consistent with acute uveitis in the OS, and traditional treatment was initiated with systemic antibiotics and anti-inflammatory drugs, topical mydriatics, and corticosteroids. During the total treatment period of 4 weeks response to treatment was weak and the horse developed further problems such as cellulitis of the right hind limb with fever and eventually weight loss and dependent edema. Blood work was indicative of liver disease. Abdominal sonography revealed severe splenomegaly and slight hepatomegaly, and a liver biopsy confirmed malignant T-cell lymphoma. The horse was euthanized due to deteriorating general condition and subsequently underwent postmortem examination. Necropsy and histologic examination revealed a multicentric lymphoma with involvement of spleen, mesenteric lymph nodes, and OU.
The findings in this case demonstrate that the differential diagnosis of intraocular and systemic lymphoma should be considered in any horse presenting with anterior uveitis, especially when uveitis is unresponsive to treatment and when additional systemic signs of illness such as lethargy, fever, weight loss, or dependent edema arise.
Cytological examination of aqueous humor may provide a rapid diagnosis of intraocular lymphoma in eyes with clinical uveitis.  相似文献   
955.
The provision of services related to green-space maintenance, such as grass cutting, tree pruning, litter collection, or weed control, is an integrated part of urban green-space management. Since contracting out has become common practice in urban green-space management, it is now a key challenge to develop well-functioning frameworks for managing the provision of outsourced green-space maintenance. With the public sector reform of the New Public Management, an emphasis on the four tenets of specification, pricing, monitoring, and enforcement of service provisions is now pervasive in the ‘standard framework’ for contract design and management. Based on an action research intervention, this paper puts forward an ‘extended’ framework for the design and management of green-space maintenance contracts that can help managers of urban green space to devise contract designs and management practices better adapted for green-space maintenance. The action research intervention took place as a part of efforts by the Danish Palaces and Properties Agency to improve green-space maintenance contracting in historic parks and gardens by implementing a performance management scheme. In addition to assessing the merits of the performance management scheme, the paper focuses on a new set of tenets related to the role of coordination, communication, motivation, and restraint of power.  相似文献   
956.
Background: Fine needle aspiration (FNA) offers a rapid and minimally invasive means to distinguish malignant from benign neoplasms. However, few studies have been published regarding the cytopathology of mammary tumors in rats despite widespread use of the rat model for breast cancer formation and inhibition.
Objective: The purpose of this study was to determine the diagnostic accuracy of FNA cytology and to develop distinguishing cytologic criteria for the diagnosis of radiation-induced benign and malignant mammary tumors in rats.
Methods: In a study of radiation-induced mammary carcinogenesis, 100 Sprague–Dawley rats with cutaneous masses were randomly chosen for FNA. The aspirates were smeared, fixed, and stained with a modified Papanicolaou procedure for diagnostic evaluation. Cytologic and histologic diagnoses (benign vs malignant) were compared, and diagnostic accuracy was calculated using the histologic diagnosis as the criterion standard. FNA smears were scored semiquantitatively on a scale of 1–4 for cellularity, atypia, nuclear size, chromatin pattern, nuclear membrane thickness, nucleoli, and mitoses. The background was evaluated for necrosis, hemorrhage, inflammation, and mucosecretory material. Cytomorphologic features were compared statistically between benign and malignant tumors, based on the histologic diagnosis.
Results: The sensitivity of FNA was 92.3% and specificity was 89.4% for the detection of malignancy. However, 14% of specimens, all fibroadenomas by histology, had insufficient cells for cytologic evaluation, for an overall accuracy rate of 78.0%. Malignant tumors had significantly higher scores for all cytomorphologic features, and were significantly more likely to contain cell clusters and necrotic debris.
Conclusions: FNA is an accurate method for differentiating benign and malignant rat mammary tumors.  相似文献   
957.
An optimised enzyme-linked immunosorbent assay (ELISA) for the detection of Dictyocaulus viviparous-specific antibodies was developed and evaluated following the testing of various microtitration plates and anti-bovine Ig-conjugates. Based on recombinant major sperm protein (MSP) expressed as a glutathione-S-transferase (GST) fusion protein in Escherichia coli, sera collected from 112 cattle experimentally infected with D. viviparus, from 129 helminth-na?ve calves, 8 calves experimentally infected with Ostertagia ostertagi, and 2 calves infected with Cooperia oncophora were tested. ELISA results showed a calculated specificity and sensitivity as well as positive and negative predictive values of >99%. No cross-reactions with sera from calves infected with O. ostertagi or C. oncophora were observed. Lungworm-specific immunoglobulins were first detected from 28 to 35 days post-infection onwards. To differentiate between antibody-binding to the MSP-part or the GST-part of the fusion protein, additional ELISAs were performed using pure recombinant MSP or GST. Optical densities obtained from the ELISAs with the MSP showed a similar pattern to optical densities measured in the ELISAs with the fusion protein, whereas GST gave only a low background. By testing serum samples from naturally infected calves, it was found that the MSP-ELISA is positive even for sera from calves showing very low faecal larval counts. Thus, we conclude that the ELISA using the recombinant MSP-fusion protein appears to be a suitable method for routine diagnosis and epidemiological studies of cattle lungworm.  相似文献   
958.
The purpose of this retrospective study was to determine the feasibility of using the end-to-end anastomosis (EEA) stapling device transrectally for managing distal colonic disease in clinical veterinary cases. Ten animals met the criteria of having distal colonic or rectal resection and anastomosis with the EEA stapling device. The only complications seen after discharge from the hospital were colonic stricture at the anastomosis site in two animals and transient colitis in two animals. The stapled anastomosis has good success when properly applied, and the incidences of stricture formation, leakage, and other potential complications can be kept to a minimum.  相似文献   
959.
As in other sub-Saharan African countries, purebred dairy genetics such as Holsteins were imported to Malawi. The study investigated their economic performance by comparing them with local Zebu-crossbreds based on 131 smallholder dairy farm observations from Southern Malawi. High-yielding purebred cows and crossbred cows showed no significant differences in lactation yield and calving interval. Looking at the farms’ actual costs, by-products such as maize bran clearly dominated the cost structure for both breeds, but crossbreeds showed significantly lower concentrate costs. While there was no statistically significant difference in income for both breed types, a substantial share (23%) of farms under investigation shows negative incomes. Based on survey data, two typical farms were established representing standard costs with homogenous assumptions such as identical milk price. The comparison of typical farms covering the full dairy system clearly indicated that crossbred dairy cows outperformed purebreds. In addition, a simulation of a shorter calving interval for both typical farms revealed a substantial positive impact on income for both breed types with more than 30% increase. We conclude that focusing on crossbreds in combination with improved feeding and fertility management offers a more promising strategy for smallholder dairy farms in Southern Malawi than just acquiring high-yielding purebreds.  相似文献   
960.
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