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blood-gas analyzers. Complete evaluation of coagulation is still often performed at a traditional laboratory. Conventional test tubes and handheld analyzers are able to determine the activated coagulation time. Several point-of-care coagulation analyzers

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in American Journal of Veterinary Research

Abstract

Objective—To characterize mobilization of secretory granules in bovine neutrophils.

Sample Population—Neutrophils obtained from four 6- to 18-month-old Holstein cattle.

Procedure—Mobilization of secretory granules in bovine neutrophils was determined by measuring changes in cell-surface alkaline phosphatase activity on cells treated with various inflammatory mediators. Subcellular distribution of the alkaline phosphatase activity was determined by analysis of bovine neutrophil homogenates fractionated on density gradients.

Results—Alkaline phosphatase-containing secretory granules of bovine neutrophils were readily mobilized by a number of inflammatory agents, including platelet-activating factor, interleukin-8, tumor necrosis factor-α, lipopolysaccharide, leukotriene B4, and zymosan-activated plasma. In contrast, N-formylmethionyl- leucyl-phenylalanine did not have a significant effect. Phorbol myristate acetate induced a biphasic response with up-regulation of cell-surface alkaline phosphatase at low doses and a return to baseline or even a reduction in cell-surface alkaline phosphatase at higher doses (≥ 10 ng/ml). Subcellular fractionation of bovine neutrophil homogenates revealed that alkaline phosphatase activity resided in light-density membrane vesicles (ie, location of secretory granules), which were distinct from specific, azurophil, and large granules.

Conclusions and Clinical Relevance—Bovine neutrophils respond to various inflammatory mediators by mobilizing alkaline phosphatase-containing secretory granules. This suggests that the process is an important early step in the host-defense response of bovine neutrophils. (Am J Vet Res 2001;62:1776–1781)

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in American Journal of Veterinary Research

, and IL-1 receptor antagonist production as well as interference with integrin signaling, induction of chondrocyte apoptosis, stimulation of metalloproteinase production and activation, and inactivation of tissue inhibitors of MMPs. 13 The PPARγ

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in American Journal of Veterinary Research

Summary

The type of plasminogen activator (pa) produced by bovine milk macrophages has been determined. Macrophages produce a pa protein with molecular weight of 28,000 and isoelectric point of 8.5, and with enzymatic activity independent of fibrin. These characteristics are identical to those reported for bovine urokinase-pa. Although blood monocytes and milk macrophages produce pa after stimulation with lipopolysaccharide, mammary macrophages are clearly limited in their ability to release pa. At maximal stimulation, 78% of the pa produced by milk macrophages remained cell-associated. In marked contrast, blood monocytes released 76% of the pa produced into the culture medium. Macrophages isolated from mastitic quarters produced higher (2.5 times) amounts of pa, compared with those produced by macrophages isolated from healthy quarters. However, in both cases, macrophages were unable to secrete the protein already produced. The limited pa secretion by milk macrophages might be a residual function of a differentiated macrophage population.

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in American Journal of Veterinary Research

, which did not permit the establishment of statistical reference values for this species. 7 , 8 Prothrombin time (PT) and activated partial PT (aPTT), evaluated in this study, are the most common screening tests for coagulopathies in mammals. PT

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in Journal of the American Veterinary Medical Association

of edema. In another study, 4 23.2% (111/478) of all IVCs placed were documented to have bacterial colonization. In a recently published study, 5 PIVCs were removed due to complications in 43% (33/76) of dogs and 52% (21/40) of cats. Force-activated

Open access
in Journal of the American Veterinary Medical Association

, and expression of adhesion molecules initiate an inflammatory response. Peroxynitrite generated by activated leukocytes 4,5 and endothelial cells 6,7 and during ischemia and reperfusion 8 is a short-lived oxidant species and potent inducer of cell

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in American Journal of Veterinary Research

minimize activation of the clotting cascade and result in the most accurate measurements. 1–3 With the increased reliance on clotting times in human medicine, techniques have been developed to collect blood samples by use of indwelling arterial catheters 4

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in American Journal of Veterinary Research

Some neuroendocrine mechanisms are triggered in humans and other animals during the development of HF that contribute to the progression of the disease. 1–7 Among the main mechanisms are stimulation of the SNS, activation of the renin

Full access
in American Journal of Veterinary Research

Abstract

Objective—To establish reference values for activated coagulation time (ACT) in cats by use of jugular venipuncture and direct collection of blood into ACT vacuum tubes.

Animals—100 clinically normal cats that were to have elective surgery performed at a private practice.

Procedure—Collection of 3 blood samples for ACT measurement was attempted for each cat at the time of elective surgery: sample 1, obtained before sedation; sample 2, tube 1 of 2 consecutive samples obtained from a single venipuncture of the contralateral jugular vein after sedation with acepromazine and ketamine hydrochloride; and sample 3, tube 2 collected immediately following collection of sample 2 without removing the needle from the vein. Venipuncture quality was rated subjectively on a 3- point scale.

Results—Median ACT were 95 seconds for each sample group. The middle 95% of values ranged inclusively from 55 to 185 seconds (sample 1), 65 to 135 seconds (sample 2), 45 to 145 seconds (sample 3), and 55 to 165 seconds overall (samples 1, 2, and 3). Significant differences in ACT values were not detected between sample groups. Significant relationships between ACT and venipuncture quality or sex of cat were not detected.

Conclusions and Clinical Relevance—With the ACT protocols used, clinically normal cats had ACT of < 165 seconds. The ACT in cats does not appear to be significantly affected by sex, sedation with acepromazine and ketamine, or by moderately traumatic venipunctures. These results refute widespread statements that ACT should be < 65 seconds in healthy cats. Cats with ACT repeatedly > 165 seconds should be further evaluated for hemostatic disorders. (Am J Vet Res 2000;61:750–753)

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in American Journal of Veterinary Research