Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.11.1.7 (peroxidase)
65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Milk samples from infected udders contained more lactoperoxidase and more thiocyanate than before infection. Irritation of 10 quarters of 5 cows caused the increase in the bacteriostatic activity of milk. Bacteriostatic activity of milk from the udders infected with staphylococci dropped after several weeks of chronic mastitis.
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PMID:Bacteriostatic activity in cow's milk from udders infected with Streptococcus agalactiae and Staphylococcus aureus. 7 71

A direct capture enzyme-linked immunosorbent assay (ELISA) was developed to measure elevated polymorphonuclear granulocyte (PMN) antigens using horseradish peroxidase (EC 1.11.1.7) conjugated rabbit polyclonal anti-PMN antisera and a monoclonal antibody specific for PMN cells. Optical densities obtained in the ELISA were used to predict the cell counts of milk samples. Predicted counts were not significantly different from actual somatic cell counts (SCC). In a total of 156 bovine milk samples the correlation coefficient between somatic cell counting, taking greater than 500,000 cells/ml as being indicative of mastitis, and the assay was 0.94, yielding an assay sensitivity of 95.2% and a specificity of 97.3%. In further trials the ELISA could detect elevated PMN antigens in milk with SCC as low as 100,000 cells/ml. The results indicate that the monoclonal antibody based direct ELISA has excellent potential in the detection and determination of bovine mastitis.
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PMID:Capture immunoassay for the diagnosis of bovine mastitis using a monoclonal antibody to polymorphonuclear granulocytes. 161 71

Two strains of Streptococcus uberis (0140J and EF20), previously shown to differ markedly in their ability to infect the mammary gland and cause clinical mastitis, showed correlated differences in their resistance to some host defence mechanisms. Both strains produced a hyaluronic acid capsule but strain 0140J, the more infective, was more resistant than EF20 to phagocytosis and killing by bovine neutrophils. Loss of the capsule from strain EF20 during the stationary phase of growth did not affect its resistance to phagocytosis. Strain 0140J also grew more rapidly than EF20 in raw skimmed milk but dithiothreitol substantially reversed this inhibition, suggesting the involvement of the lactoperoxidase system in the inhibitory effect of raw milk.
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PMID:Two strains of Streptococcus uberis, of differing ability to cause clinical mastitis, differ in their ability to resist some host defence factors. 238 62

Twenty-eight pregnant goats in midgestation were exposed to a bovine pathogenic strain of Brucella abortus to determine the histologic changes associated with infection. Does were necropsied 0 to 7 days or 4 to 6 weeks after delivery of aborted, stillborn, or live, full-term fetuses. Aborted and stillborn fetuses were necropsied within 16 hours of delivery. Selected, paired tissue specimens were collected for histologic and bacteriologic examination. An avidin-biotin-peroxidase complex immunostaining procedure was used to detect Brucella antigen in tissue section. Histologic changes were evident in specimens from infected does and aborted fetuses. Postpartum does had endometritis, lymphoid hyperplasia in lymph nodes and spleen, and lymphocytic mastitis. The most prominent finding in aborted fetuses was an interstitial pneumonia. Lesions in does and fetuses were similar to those described in Brucella-infected cows and fetuses; however, lesions were less consistently observed in goat fetuses than has been observed in bovine fetuses. Brucella antigen was detected by immunoperoxidase staining within the cytoplasm of placental chorioallantoic trophoblastic cells, macrophages, neutrophils, and uterine epithelial cells. Also, stained brucellae were free in placental and fetal vascular lumens and in the interstitium of autolyzed fetal tissues.
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PMID:Histopathologic findings in Brucella abortus-infected, pregnant goats. 312 86

Two groups of dairy herds (16 herds/group) were studied to determine the relationship between the prevalence of mastitis in a herd and mean herd blood concentrations of vitamins A and E, beta-carotene, and selenium (Se). One group had a Dairy Herd Improvement Association 12-month mean herd somatic cell count (SCC) of less than or equal to 150,000 cells/ml. The second group had a Dairy Herd Improvement Association 12-month mean herd SCC of greater than or equal to 700,000 cells/ml. Once for each herd, duplicate milk samples were collected from each quarter of the lactating cows, and blood samples were collected from 21 cows in various stages of lactation. Serum concentrations of vitamin A, beta-carotene, and vitamin E and whole blood concentrations of Se and Se-dependent glutathione-peroxidase (GSH-Px) were determined. Significant differences between the 2 groups were not found with respect to serum concentrations of vitamin A, vitamin E, or beta-carotene. However, the herds with the low SCC (less than or equal to 150,000 cells/ml) had significantly higher mean (+/- SEM) blood GSH-Px activity (35.6 +/- 2.95 mU/mg of hemoglobin) than did the herds with the high SCC (20.2 +/- 2.38 mU/mg of Hb). Whole blood concentrations of Se also were significantly higher in the herds with low SCC (0.133 +/- 0.010 microgram/ml of blood) than in the herds with high SCC (0.074 +/- 0.007 microgram/ml of blood). Significant negative correlations were found between the prevalence of intramammary infection with major pathogens and mean herd activity of GSH-Px (r = -0.62) and mean herd concentrations of Se (r = -0.66).
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PMID:Blood selenium concentrations and glutathione peroxidase activities in dairy herds with high and low somatic cell counts. 330 63

Plasma and milk levels of vitamin E were determined in mastitic and healthy cows and compared with erythrocyte GSH and GSH-peroxidase, selenium, silicon, prostaglandins and parameters commonly used for diagnosing mastitis. In mastitis both the plasma and milk levels of vitamin E were significantly lowered. In the milk vitamin E correlated negatively with electrical conductivity and PGE2. In the blood vitamin E was in a positive correlation with erythrocyte GSH. The role of lipid peroxidation in relation to the inflammatory and immunological reactions of mastitis is discussed.
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PMID:Possible roles of vitamin E and glutathione metabolism in bovine mastitis. 347 54

Cell-free, fat-free mammary secretions were tested in vitro for ability to support growth of streptococci associated with mastitis. Secretions were obtained prior to drying off, during the dry period, at calving, and during lactation from four cow treatment groups. Treatment groups were dry cow therapy, dry cow therapy and mammary glands subjected to induced inflammation 7 d post-drying-off, no dry cow therapy and no induced inflammation, no dry cow therapy but mammary glands subjected to induced inflammation. Growth of Streptococcus uberis, Streptococcus faecalis, and Streptococcus agalactiae in secretions from nonlactating glands was unaffected by induced inflammation. Growth of Streptococcus bovis was significantly inhibited in secretion obtained 14 d after induced inflammation. Dry cow therapy had no effect on streptococcal growth in secretion obtained 7 d after therapy. Streptococcal growth was greatest in secretions from involuted glands, and there was little or no evidence for growth inhibitory factors in cell-free, fat-free secretions obtained during the dry period. Milk from lactating glands inhibited streptococcal growth, and the inhibitory factor was presumptively identified as lactoperoxidase. Apolactoferrin, immunoglobulin, or both had little effect on streptococcal growth.
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PMID:In vitro growth of mastitis-associated streptococci in bovine mammary secretions. 390 91

Neutrophil functions were examined in healthy periparturient dairy cows (n = 46) and in cows with retained placenta and metritis complex (n = 20); metritis (n = 18); or mastitis (n = 13). Blood samples (50 ml) were collected from each cow via jugular vein twice weekly from 1.5 weeks before to 4 weeks after parturition. Neutrophil function was evaluated, using 6 tests: random migration, chemotaxis, ingestion, myeloperoxidase activity (iodination), superoxide production (cytochrome C reduction), and antibody-dependent cell-mediated cytotoxicity. Ability to ingest bacteria and random migration activity of neutrophils from clinically normal cows were high around parturition and increased immediately after parturition, whereas myeloperoxidase activity and antibody-dependent cell-mediated cytotoxicity ability of neutrophils from these cows decreased after parturition. Measurement of neutrophil function in 4 ovariectomized cows revealed significant (P < 0.0005) seasonal changes in results of all 6 functional assays. We observed various defects of neutrophil function in all cows with abnormal conditions after parturition. Before parturition, superoxide production activity by neutrophils from cows with metritis and chemotaxis by neutrophils from cows with mastitis were significantly (P < 0.001 and P < 0.05, respectively) lower, indicating that a defect of neutrophil function may be a predisposing factor in the development of these disorders. In conclusion, the host defense role of neutrophils in periparturient cows was impaired, principally because of a defect in killing capacity, which may increase susceptibility to infections. We also investigated the in vitro effects of arachidonic acid metabolites and recombinant human colony-stimulating factors (rhCSF) on functions of neutrophils from clinically normal and postparturient cows with abnormalities, including retained placenta, metritis, or mastitis (n = 5/group). Each abnormal cow was matched for postpartum period with a clinically normal cow. Neutrophils from individual cows were preincubated with arachidonic acid metabolites (prostaglandin F2 alpha, 10(-7) M; prostaglandin E2, 10(-6) M; leukotriene B4, 10(-8) M; and lipoxin B, 10(-8) M) and rhCSF (rh-granulocyte-CSF, 1,000 or 6,000 U/ml; rh-granulocyte-macrophage-CSF, 5 or 15 ng/ml) in a 37 C water bath for 30 minutes before submitting them to function assays. There was no response by neutrophils from either clinically normal or abnormal postparturient cows to treatment with either arachidonic acid metabolites or rhCSF in any of the 6 functional assays. However, preincubation of neutrophils alone in a 37 C water bath for 30 minutes resulted in some alteration of neutrophil function.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Association between neutrophil functions and periparturient disorders in cows. 752 53

During three lactational periods (start, middle and end of lactation) of 35 milk cows suffering from mastitis and compared with 34 healthy milk cows of comparable milk production the activity of lactoperoxidase (LPO) and the SCN-content of the milk in each udder quarter were determined. Both components showed no alterations in the subclinical form of the disease. There exists a decrease of the LPO activity in the secretion of ill udder quarters, which will be distinct only in the individual animal and a strong increase of the SCN-content, which is also significant in comparison with the milk of healthy cows.
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PMID:[Lactoperoxidase activity and thiocyanate content of milk from cows with mastitis in different lactation stages]. 764 26

Myeloperoxidase (MPO) is a lysosomal enzyme found in the primary granules of mammalian neutrophils. Together with MPO, peroxide and halide form a system of defense against bacteria. The present investigation was undertaken to study the bactericidal effects of the bovine-MPO/peroxide/halide system on pathogenic bacteria associated with bovine mastitis. We demonstrated that MPO together with oxidizing agents generated by xanthine oxidase, hypoxanthine and chloride form a potent antibacterial system against the common udder pathogens Staphylococcus aureus, Streptococcus uberis, Streptococcus agalactiae, Streptococcus dysgalactiae and Escherichia coli in a synthetic medium. However, when milk was added to the reaction mixture, the bactericidal properties of this enzyme system were completely inhibited. Loss of bactericidal activity in the milk-containing cultures was unable to be restored by increasing the concentration of MPO. Nor did an increase in concentrations of hypoxanthine and xanthine oxidase, or the replacement of the above-mentioned peroxidase generating system with a high concentration of hydrogen peroxide, significantly elevated the bactericidal activity that was inhibited by milk. The addition of bovine serum albumin to the synthetic medium reduced the bactericidal activity of the MPO/peroxide/chloride system in a dose-dependent manner. Therefore, milk proteins probably form adducts with strong bactericidal agents that are generated by the MPO system and thereby reduce the bactericidal potential of this system.
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PMID:Bactericidal activity of the bovine myeloperoxidase system against bacteria associated with mastitis. 856 Jul 39


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