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:3.2.1.17 (lysozyme)
21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Previous studies on the fractionation of human neutrophil granules have identified two major populations: myeloperoxidase (MPO)-containing azurophil, or primary, granules and MPO-deficient specific, or secondary, granules. Peripheral blood neutrophils from individual donors were lysed in sucrose-free media by either hypotonic shock or nitrogen cavitation. Using a novel two-gradient Percoll density centrifugation system, the granule-rich postnuclear supernatant was rapidly (ten minutes) and reproducibly resolved into 13 granule fractions (L1 through L8 and H1 through H5). Granule flotation and recentrifugation experiments on both continuous, self-generated and multiple-step gradients using individual and mixed isolated fractions demonstrated that the banding patterns were isopycnic and nonartifactual. Isolated granules were intact based on the findings that biochemical latency of several granule enzymes was greater than 95%, and thin-sectioned electron micrographs demonstrated intact granule profiles. Biochemical analyses of the granule marker proteins MPO, beta-glucuronidase, lysozyme, and lactoferrin indicated that a number of the fractions were related to the major azurophil and specific granule populations. Lactoferrin was found in ten of 13 fractions (L1 through L8, H1 to H2), whereas MPO was found in every fraction. Consistent with these biochemical data, all fractions exhibited varying degrees of heterogeneity based on ultrastructural morphology and cytochemistry, including diaminobenzidine (DAB) reactivity for peroxidase and periodate-thiocarbohydrazide-silver proteinate (PA-TCH-SP) staining for complex glycoconjugates. A variable but significant percentage (23% to 70%) of the granules in fractions L1 through L8 and H1 and H2 showed DAB reactivity, while about 90% of the granules in fractions H3 through H5 were peroxidase positive. These results demonstrated that DAB-reactive granules spanned the entire range of granule size and density. Ultrastructural PA-TCH-SP staining of isolated granule fractions revealed patterns similar to those of granules in intact neutrophils at different stages of development. Granules from human acute promyelocytic leukemia cells (HL-60) exhibited a surprisingly low density compared with typical azurophil granules from normal, mature neutrophils. The data suggest that both functional and maturational differences contribute to granule heterogeneity, and provide a new practical and conceptual framework for further defining the phenomenon of neutrophil granule heterogeneity.
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PMID:High resolution of heterogeneity among human neutrophil granules: physical, biochemical, and ultrastructural properties of isolated fractions. 301 86

The extensive literature on natural antimicrobial systems in animals, plants, and microorganisms is surveyed and particular systems are discussed, viz., the peroxidase systems in saliva and milk, singlet oxygen in the phagosome, cecropins and attacins in insects, complement, lysozyme and, to a limited extent, phytoalexins. The review draws attention to the cardinal role of targets on the cell envelopes of alien cells, especially bacteria, and emphasizes a possible approach to preservation based on the selection of specific agents for particular targets. The available evidence suggests that the perturbation of the homeostasis of all the organisms in the mixed flora of a food is unlikely to be achieved by one antimicrobial substance in isolation. Future studies need to consider therefore a tandem approach with two or more agents chosen because of their complementary action. Alternatively, natural system(s) and an established preservative method, either chemical or physical, warrant investigation. The extensive literature on the mechanisms whereby specialist pathogens overcome the defenses of plants and animals emphasizes the inherent dangers of selection leading to the persistent contamination of food processing areas with organisms tolerant of a particular antimicrobial system.
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PMID:Natural antimicrobial systems and their potential in food preservation of the future. 301 80

Reduced bacterial killing by polymorphonuclear leucocytes has been reported in patients with diabetes mellitus. Whether this is due to reduced content of bactericidal granular proteins has not been determined. We therefore immunochemically measured the content of myeloperoxidase, lactoferrin, lysozyme, cathepsin G and elastase in polymorphonuclear leucocytes from 50 insulin-treated diabetic patients. The peroxidase activity was also measured. Normal contents of myeloperoxidase and lactoferrin as well as normal peroxidase activity were found. The average contents of cathepsin G, elastase and lysozyme were 2.5, 3.2 and 2.6 micrograms/10(6) polymorphonuclear leucocytes, respectively, and thus 14, 45 and 18% higher than the contents of normal polymorphonuclear leucocytes. The results indicate that reduced intracellular killing of bacteria demonstrated in previous studies in diabetic patients does not appear to be related to a reduction in the content of bactericidal proteins.
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PMID:Bactericidal proteins and neutral proteases in diabetes neutrophils. 301 98

The rabbit defense system has a number of specific features: no lactoferrin and lysozyme are detectable and peroxidase activity is only demonstrated in the cubic epithelial cells of the ducts. Experiments carried out with radioactive amino acid, demonstrate the absence of secreted proteins with molecular weights corresponding to those of albumin and transferrin, indicating that these proteins are not synthesized by the lacrimal gland tissue. Rabbit tear pattern presents a set of acidic proteins secreted by the lacrimal gland tissue, with small molecular weight and acidic pI's.
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PMID:Relationship between lacrimal gland, isolated cells (lacrimocytes) and tears: biochemical and histological studies in the rabbit eye. 302 95

An 18-year-old woman had a 3-month history of increasing proptosis and visual loss secondary to an inferior orbital mass. Surgical exploration revealed an encapsulated mass in the orbit. After this mass was excised good vision was restored. The diagnosis of granular cell tumor was made as a result of various microscopic studies. The location of the tumor within the orbit is unusual and its histologic origin is uncertain. Immunohistochemistry by peroxidase-antiperoxidase method revealed that this tumor had S-100-protein-positive cells and negative results for lysozyme and alpha-1-antitrypsin. This fact suggests that the origin of the granular cell tumor may be due to the Schwann cell.
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PMID:Granular cell tumor of the orbit. 303 88

Defensins are a newly recognized class of small, cationic polypeptides that have in vitro microbicidal activity toward certain bacteria, fungi, and viruses. Human neutrophil granules were separated into 13 density fractions by using a high-resolution Percoll gradient centrifugation procedure, and the distribution of the three defensin polypeptides in these fractions was determined. Levels of defensins and several granule marker proteins were estimated in each fraction from relative staining intensities of bands following acid-urea and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of total acid-extractable proteins. These results were confirmed by enzyme immunoassay measurements of defensins and quantitative determinations of the typical azurophil granule components, myeloperoxidase, beta-glucuronidase, lysozyme, and elastase. The five higher density granule fractions (H1 through H5) contained fourfold higher relative amounts of defensins as compared with the eight lower density fractions (L1 through L8), accounting for approximately 50% of the total protein. In particular, fraction H5 was especially enriched in defensins but was relatively deficient in myeloperoxidase, beta-glucuronidase, lysozyme, and elastase. Ultrastructural morphology showed that fraction H5 contained the largest granules. Seventy percent of these granules exhibited electron-dense rims and electron-lucent central regions when stained with methanolic uranyl acetate-lead citrate, and 70% showed this same characteristic rim-staining pattern after limited reaction (30 minutes) for peroxidase with diaminobenzidine. These distinctively large, rim-stained granules were identified in intact, mature peripheral blood neutrophils as well as in human bone marrow promyelocytes, indicating that their synthesis occurs during early myeloid development. This unusual granule type may play a specialized role in the microbicidal functions of the neutrophil, distinct from that of typical azurophil granules.
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PMID:Defensin-rich dense granules of human neutrophils. 304 Jan 55

Antimicrobial agents (antibody and non-antibody) present in human saliva protect oral tissues by a variety of mechanisms, such as prevention of bacterial adhesion, agglutination of micro-organisms, and inhibition of multiplication and metabolism. However, studies in which the concentrations of various salivary antimicrobial agents have been correlated to the presence and severity of oral diseases--of dental caries, in particular--have produced controversial data, and it seems evident, also on the basis of the present study, that no single salivary antimicrobial factor (except flow rate) affects oral health to a significant degree. In the present study, we report the levels of some selected salivary antimicrobial agents in predentate and dentate human infants, with a comparison to the levels found in young adults' saliva. Salivary lysozyme, peroxidase, and hypothiocyanite concentrations were already at the adult level at the time when the primary teeth erupt, whereas immunoglobulin (IgA, IgG, and IgM), lactoferrin, myeloperoxidase, and thiocyanate concentrations were significantly lower in children than in adults. Dentate children had more IgG, thiocyanate, and protein in whole saliva than did predentate children.
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PMID:Antimicrobial factors in saliva: ontogeny and relation to oral health. 304 Aug 24

The immunohistochemical detection and distribution of lysozyme (Ly), Lactoferrin (Lf), a1-Antichymotrypsin (a1-AChy), a1-Antitrypsin (a1-AT) and Carcinoembryonic antigen (CEA) were studied in neonate and adult parotid gland tissue, using the peroxidase-antiperoxidase (PAP) method. Ly stain in neonates extended into acini, intercalated ducts and occasional cells of large ducts, whereas in adults Ly was usually confined to the intercalated ducts. The distribution pattern of Lf in neonates varied considerably between individual glands showing three staining patterns. Most of the intercalated ducts, some groups of acini and rare striated duct cells were positive for Lf in adults. a1-AChy and a1-AT in neonates were positive mainly in the large ducts, whereas staining for a1-AChy and a1-AT in adults frequently extended into some intercalated duct cells, although less intensively. Finally, CEA in neonates was localized in the lumina and luminal membranes of the acini, in intercalated ducts, and less frequently in the large ducts. In adults CEA was present predominantly in the lumina and luminal membranes of the intercalated duct cells. These differences may suggest an immunohistochemical postnatal differentiation of the parotid gland.
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PMID:An immunohistochemical study of normal human neonate and adult parotid gland tissue. Detection of lysozyme, lactoferrin, a1-antichymotrypsin, a1-antitrypsin and carcinoembryonic antigen. 304 15

Paraffin-embedded tissue sections taken from 16 patients with dermatofibrosarcoma protuberans were stained by means of the peroxidase-antiperoxidase technique using antibodies against S 100 protein, NSE, Leu 7, lysozyme, alpha-1 antitrypsin, alpha-1 antichymotrypsin, cytokeratin, desmin, vimentin, and factor VIII. Most of the tumor cells showed positive reactions to vimentin. Only 1-3% of the cells within the tumor area answered to the histiocytic markers lysozyme, alpha-1 antitrypsin, and alpha-1 antichymotrypsin. The remaining antibodies investigated did not react with the tumor cells. Our results support a fibroblastic, and contradict a neural or histiocytic, histogenesis of dermatofibrosarcoma protuberans.
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PMID:[Immunohistochemical studies of the histogenesis of dermatofibrosarcoma protuberans]. 305 28

A retrospective study of 76 primary gastrointestinal lymphomas utilizing an avidin: biotinylated horseradish peroxidase complex (ABC) technique demonstrated 22 B-cell lymphomas, including two associated with alpha-heavy chain disease. Seven cases were classified as true histiocytic lymphomas based on a positive reaction for one or more of three histiocytic enzyme markers utilized, predominantly alpha-1-antitrypsin and alpha-1-antichymotrypsin. However, in 20 cases, an intense admixture of reactive histiocytes was noted and these cells stained preferentially for the enzyme, lysozyme. Twenty cases, which stained for both kappa and lambda light chains and positively or negatively for albumin, could not be classified and 27 cases failed to stain with any of the antisera utilized.
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PMID:Immunohistochemistry of primary gastrointestinal lymphomas: a study of 76 cases. 308 8


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