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)

Twenty cases of acute or early multiple sclerosis have been examined using staining, histochemical or immunocytochemical methods. They had died within 6 months after initial clinical onset (12) or commencement of an "anatomically-remote" acute relapse (8). Plaques in these acute cases showed the following characteristics: lymphocytic perivascular infiltration, plaque hypercellularity, plaque macrophage infiltration and intra-macrophage myelin debris. In most cases of clinical duration of less than 12 weeks, some macrophages showed characteristic formaldehyde-resistant markers for haematogenous macrophages (muramidase, anti-alpha 11-antitrypsin, MAC and HAM56) but, with the exception of the last, these markers subsequently declined indicating a haematogenous origin for macrophages in the early lesion. Lymphocytes were prominent in perivascular (perivenous) regions but, except in one case, were only scanty in or at the demyelinating edge of plaques. Oligodendroglial hyperplasia, indicative of remyelinating activity, was seen at the edge of plaques in one quarter of these acute cases (7 times the rate seen in chronic lesions). Astrocytic activation was not apparent in the earliest stages but was usually seen from about 6 weeks onwards. The conclusion from these observations is that the prime inflammatory process is around blood vessels with usually only scanty initial inflammatory activity in the parenchyma of the brain. Macrophages emigrating from blood vessels digest myelin either as a response to inflammatory damage to the myelin or as a response to activation signals produced in either the perivascular region or plaque.
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PMID:Pathology, histochemistry and immunocytochemistry of lesions in acute multiple sclerosis. 280 22

This paper presents a study on the structure and function of Kupffer cells (KC) and liver endothelial cells (LEC) isolated by a simple and rapid technique involving 1) perfusion of the liver with collagenase; 2) cell separation by means of density centrifugation in Percoll; and 3) cell culture, taking advantage of the fact that KC and LEC differ in their preferences for growth substrate. The KC, which attach and spread under serum-free conditions on surfaces of glass or plastic during the first 15 min in culture exhibit a typical macrophage-like morphology including membrane ruffling and a heterogenous content of vacuoles. Moreover, these cells express (a) Fc receptors (FcR) for binding and phagocytosis of erythrocytes covered with immune globulin G (E-IgG), and (b) complement receptors (CR) for binding and serum dependent phagocytosis of erythrocytes covered with either human C3b or mouse inactivated C3b (iC3b). The cells also bind fluid phase fluoresceinated C3b. Approximately 30% of the KC express immune response-associated (Ia)-antigens. The LEC attach and spread on fibronectin coated surfaces, but not on glass or plastic surfaces, during the first two hours in culture with or without serum, and are morphologically distinct from KC. Cultured LEC are well spread out with no membrane ruffling and with numerous large vesicles surrounding the regularly shaped nucleus. These cells bind, but do not ingest E-IgG via the FcR, but no binding of fluid phase C3b or particle fixed C3b or iC3b can be observed. Incubation of LEC with fluorescein amine conjugates of ovalbumin or formaldehyde treated serum albumin, but not with fluoresceinated native serum albumin, results in accumulation of fluorescence specifically localized in the large perinuclear vesicles. Neither KC nor any other cell types tested have the ability to accumulate fluorescence upon incubation with these compounds. Ia-antigens are not present on the LEC. Cytochemical demonstration of unspecific esterase, acid phosphatase, and peroxidase reveals different patterns and intensities of staining in KC as compared to LEC.
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PMID:Functional and morphological characterization of cultures of Kupffer cells and liver endothelial cells prepared by means of density separation in Percoll, and selective substrate adherence. 299 96

The ionic complex between lysozyme and either Escherichia coli DNA or pBR322 DNA was not crosslinked by two systems capable of producing nanomolar amounts of hydroxyl radicals, the oxidation of xanthine by xanthine oxidase and the iron catalyzed oxidation of ascorbic acid. Nor did effective crosslinking occur with micromolar quantities of hydroxyl radicals raised by the addition of adenosine nucleotides to ferrous iron and hydrogen peroxide. In this case, radical content was estimated by colorimetric analysis of formaldehyde following hydroxyl radical oxidation of dimethyl sulfoxide. Similar amounts of radicals generated by pulse radiolysis in a nitrous oxide atmosphere failed also to induce crosslinking. These findings do not support a role for hydroxy radicals in the N-acetoxy-2-acetylaminofluorene induced crosslinking of DNA to lysozyme proposed earlier.
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PMID:Hydroxyl radicals do not crosslink a DNA-lysozyme complex. 299 38

Murine peritoneal macrophages were cultured with heat-killed Listeria monocytogenes organisms and then with the protein hen egg white lysozyme. Hen egg lysozyme is well known to need intracellular processing for presentation to T cells. The presentation to T cells of lysozyme was affected despite no reduction in the amount taken up or catabolized by the macrophage. This interference with Ag presentation was not found if the macrophages were cultured with lysozyme before the Listeria pulse. The interference with Ag presentation induced by Listeria was found for a second Ag (conalbumin). Uptake of Listeria did not affect the presentation of the lysozyme peptide 46-61, indicating that MHC class II molecules were available at the macrophage surface. Other materials that are retained in the macrophages affected presentation of lysozyme but not of the processed peptide. These included SRBC, dextran, sucrose, cellobiose, polyvinyl pyrrolidone, sodium dextran sulfate, Ficoll, and polyethylene glycol. Except for SRBC, which were not tested, the remaining molecules did not interfere with presentation of 46-61 by formaldehyde-fixed macrophages, an indication that they did not affect the peptide interaction with class II molecules. Finally, uptake of latex beads did not affect presentation of lysozyme. We conclude that retention in the macrophage of a variety of soluble or particulate molecules can interfere with the intracellular events that result in the creation of an immunogenic determinant. This interference is independent of the catabolism of the Ag or of the availability of class II molecules to bind peptides.
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PMID:Intracellular interference with antigen presentation. 313 57

Alkaline phosphatase activity in mouse liver blocks, cooled by an ice-bath, decreased by 50% in 5 min of microwave irradiation (280 W). This loss of protein tertiary structure has been mirrored by ultrastructural changes in the same tissue. Microwave irradiation did not produce cleavage or polymerization of lysozyme or haemoglobin. Protein formaldehyde reaction mixtures produced protein polymers between 0 degree and 40 degrees C which could be separated by SDS-polyacrylamide gel electrophoresis. Microwave irradiation of lysozyme or haemoglobin plus formaldehyde on ice-bath up to 30 min produced a similar electrophoretic pattern. When lysozyme or haemoglobin plus formaldehyde was heated to 60 degrees C for 30 min, the protein polymers migrated faster on electrophoresis, suggesting a smaller hydrodynamic volume than expected due to intramolecular crosslink formation, not opened up under the conditions of electrophoresis.
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PMID:Differentiating the effects of microwave and heat on tissue proteins and their crosslinking by formaldehyde. 322 Jul 96

Five out of eight consecutive cases with initial symptoms of a 'midline granuloma' were identified as malignant histiocytosis (histiocytic sarcoma) which within 5 months to 4 years led to generalization and death. The three remaining cases also fulfilled the morphological criteria of this type of neoplasia, though these patients are still alive 1/2 to 8 years after diagnosis, possibly as a result of local radiotherapy. The age of the individuals ranged from 18 to 71 years and there was a male preponderance of 7:1. The histiocytic nature of the atypical cells was primarily documented by intense activity of NaF-inhibitable non-specific esterase, of acid phosphatase and of beta-glucuronidase as demonstrated in cryostat sections of formaldehyde-saccharose-fixed fresh biopsy specimens and by the detection of alpha-1-antichymotrypsin, alpha-1-antitrypsin, and lysozyme antigens, in that order of constancy (immunohistochemical examination of formaldehyde-fixed paraffin sections, using the avidin-biotin-peroxidase complex method). There was among the reported cases a considerable heterogeneity with regard to these 'markers'. We conclude that malignant histiocytosis is a (the?) major cause of the 'midline granuloma syndrome'.
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PMID:Malignant histiocytosis (histiocytic sarcoma). A (the?) major cause of the 'midline granuloma syndrome'. 351 40

Bacteriophage phiX174 is an icosahedral phage which attaches to host cells without the aid of a complex tail assembly. When phiX174 was mixed with cell walls isolated from the bacterial host, the virions attached to the wall fragments and the phage deoxyribonucleic acid (DNA) was released. Attachment was prevented if the cell walls were treated with chloroform. Release of phage DNA, but not viral attachment, was prevented if the cell walls were incubated with lysozyme or if the virions were inactivated with formaldehyde. Treatment of the cell walls with lysozyme released structures which were of uniform size (6.5 by 25 nm). These structures attached phiX174 at the tip of one of its 12 vertices, but the viral DNA was not released. The virions attached to these structures were oriented with their fivefold axis of symmetry normal to the long axis of the structure. No virions were attached to these structures by more than one vertex. Freeze-etch preparations of phiX174 adsorbed to intact bacteria showed that the virions were submerged to one half their diameter into the host cell wall, and the fivefold axis of symmetry was normal to the cell surface. A second cell could not be attached to the outwardly facing vertex of the adsorbed phage and thus the phage could not cross-link two cells. When the virions were labeled with (3)H-leucine, purified, and adsorbed to Escherichia coli cells, about 15% of the radioactivity was recovered as low-molecular-weight material from spheroplasts formed by lysozyme-ethylenediaminetetraacetic acid. Other experiments revealed that about 7% of the total parental virus protein label could be recovered in newly formed progeny virus.
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PMID:Mode of host cell penetration by bacteriophage phi X174. 410 19

1. Particulate enzyme preparations obtained from Bacillus stearothermophilus B65 by digestion with lysozyme were shown to catalyse teichoic acid synthesis. With CDP-glycerol as sole substrate the preparations synthesized 1,3-poly(glycerol phosphate). It was characterized by alkaline hydrolysis, by glucosylation to the alkali-stable 2-glucosyl-1,3-poly(glycerol phosphate) with excess of UDP-glucose and a Bacillus subtilis Marburg enzyme system, by degradation of this latter product with 60%HF and periodate oxidation of the resulting glucosylglycerol. The specificity of the B. subtilis system previously reported (Glaser & Burger, 1964), was confirmed in the present work. 2. Pulse-labelling experiments, followed by periodate oxidation of the product and isolation of formaldehyde from the glycerol terminus of the polymer, showed that the B. stearothermophilus enzyme system transferred glycerol phosphate units to the glycerol end of the chain. The transfer reaction was irreversible. It was not determined if these poly(glycerol phosphate) chains were synthesized de novo, but it was shown that the newly synthesized oligomers were bound to much larger molecules. 3. When the B. stearothermophilus enzyme system was supplied with both CDP-glycerol and UDP-glucose, 1-glucosyl-2,3-poly(glycerol phosphate) was synthesized in addition to the 1,3-isomer. The former polymer was characterized by acid and alkaline hydrolysis, degradation with HF and periodate oxidation of the resulting glucosylglycerol, and periodate oxidation of the intact polymer followed by mild acid hydrolysis. This latter procedure removed the glucose substituents without disrupting the poly(glycerol phosphate) chain. 4. The poly(glycerol phosphate) isomers were distinguished by glucosylation with the B. subtilis enzymes and alkaline hydrolysis, the 2,3-isomer remaining alkali-labile. The proportion of 2,3-poly(glycerol phosphate) in the product increased with increasing amounts of UDP-glucose in the incubation mixture, but the total glycerol phosphate incorporated into products remained constant. It is suggested that the synthetic pathways of the two poly(glycerol phosphate) species may share a rate-limiting step.
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PMID:Teichoic acid synthesis in Bacillus stearothermophilus. 442 46

Since lysozyme and alpha 1-anti-chymotrypsin are constituents of normal histiocytes, their value as tumor cell markers in histiocytes neoplasias has been investigated using the indirect immunoperoxidase method and commercially available specific antisera on formaldehyde-fixed, paraffin-embedded 5 micrometers sections after pretreatment with pronase. The distribution of both markers was determined in 35 cases of malignant fibrous histiocytoma (MFH) and in 13 cases of malignant histiocytosis (MH). In 12 cases of MH both markers were found whereas in MFH alpha 1-antichymotrypsin was demonstrated in 26 and lysozyme in 16 cases only. In general, the staining for alpha 1-anti-chymotrypsin was more intense than the staining for lysozyme. A negative reaction does not exclude the possibility of MH or MFH. The presence of both constituents in tumours, however, can be considered as indicative of histiocytogenic origin and both can be useful markers for distinguishing histiocytic neoplasias from other tumours.
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PMID:Lysozyme (muramidase) and alpha 1-anti-chymotrypsin as immunohistochemical tumour markers. 628 96

Quantitative estimation of native and treated with 4% formaldehyde albumin, pepsin, lysozyme, histone, gelatin and other proteins was carried out using four procedures--biurete, Lowry-Folin, ninhydrin and coomassy R-250. Chromogeneity of proteins in corresponding color reactions was expressed as OD per 100 micrograms of nitrogen estimated by means of Kjeldahl micromethod. The proteins were treated with formaldehyde in corresponding buffers at 20 degrees within 7 days, non-bound or loosely bound formaldehyde was dialysed. Native proteins were dissimilar in their chromogeneity; these differences were the highest for Lowry-Folin and coomassy procedures. Formalinization affected the protein chromogenencity depending on a protein nature, conditions of formaldehyde treatment and on the procedure of estimation used. As shown by analysis of the data obtained the alterations of chromogeneity did not reflect the rate of reactive group blocking by formaldehyde in a protein molecule. The quantitative methods should be used very carefully in estimation of formalinized proteins.
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PMID:[Estimation of various quantitative methods for the determination of native and formaldehyde-treated proteins]. 640 1


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