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)

Using 12-day old baby mice, strain NMRI, the LD50 of a Herpes simplex virus type 1 was calculated. Intragastric inoculation of the mice was carried out applying a stomach tube. Lethality of the mice was reduced from 67% to 23% by pre-incubation of the virus suspension for 30 min at 37 degrees C in the presence of 0.2 mg tyrothricin/ml. The effect was statistically significant and could be produced only after direct contact between tyrothricin and virus. Under the same conditions there was no effect of lysozyme against virus infectivity.
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PMID:[Experimental protection with tyrothrizin against herpes simplex virus infections in mice]. 58 19

Accurate diagnosis of uveitis is of great importance since the treatment for the various uveitis entities may differ considerably. In a large number of cases the clinical picture is sufficient to make an adequate diagnosis. There are cases in which the diagnosis cannot be made on clinical grounds alone and support is needed from laboratory tests. Only a limited number of tests have been proven to be useful as a diagnostic or prognostic aid. These include HLA-B27 typing in patients presenting with anterior uveitis and testing for angiotensin converting enzyme and lysozyme in case of suspected sarcoid uveitis. Toxoplasma serology is only useful to exclude the diagnosis and a positive test has very low specific value. Analysis of local intraocular antibody production is a valuable tool to confirm a suspected clinical diagnosis in uveitis. It is now possible to analyse paired serum and aqueous samples for the presence of specific antibodies against toxoplasma, cytomegalovirus, herpes simplex virus and varicella zoster virus using commercially available kits. Of the patients retrospectively diagnosed as having toxoplasma chorioretinitis 75% were shown to have a positive antibody coefficient indicating specific intraocular antibody production. Local antibody production in the eye directed against CMV confirmed the suspected diagnosis of CMV retinitis in 50% of the AIDS patients investigated. Until now we have not been able to measure local antibody production against herpes simplex virus (26 samples tested). Two of three patients with acute retinal necrosis had a positive antibody coefficient against varicella zoster virus. Both of these patients even had a higher titre in the aqueous than in serum. Since the choice of treatment, in infectious uveitis, depends on the causative organisms, it is very important to confirm a suspected clinical diagnosis with aqueous humor analysis.
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PMID:The value of laboratory testing in uveitis. 217 95

Matrix attachment regions (MARs) are DNA elements that dissect the genome into topologically separated domains by binding to a chromosomal skeleton. This study explored the putative influence of the MAR located 5' of the chicken lysozyme gene on expression of heterologous genes in heterologous cell systems. Expression of a construct with the chloramphenicol acetyltransferase (CAT) indicator gene controlled by the herpes simplex virus thymidine kinase promoter (TC) and a construct in which the same transcriptional unit is flanked by chicken lysozyme 5' MARs (MTCM) was assayed after stable transfection into rat fibroblasts. Median CAT activity per copy number in MTCM transfectants was elevated approximately 10-fold relative to that in TC transfectants. Total variation in normalized CAT activity decreased from more than 100-fold among TC transfectants to nearly 6-fold among MTCM transfectants. The steady-state level of transcripts and the relative rate of transcription were increased in MTCM transfectants, as shown by S1 nuclease and run-on transcription assays, respectively. The chicken lysozyme 5' MAR thus can confer elevated, less position-dependent expression on a heterologous promoter in cells of a different species by increasing the density of transcribing RNA polymerase molecules. MAR-mediated transcriptional enhancement suggests that MARs are important for gene expression and not just for DNA packaging.
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PMID:The chicken lysozyme 5' matrix attachment region increases transcription from a heterologous promoter in heterologous cells and dampens position effects on the expression of transfected genes. 232 53

Vimentin is one member of the intermediate filament multigene family which exhibits both tissue- and developmental stage-specific expression. In vivo, vimentin is expressed in cells of mesenchymal origin. Previously, we identified both enhancer and promoter elements in the chicken vimentin gene which regulate gene expression in a positive manner. In this report, we have identified a 40-base-pair region at -568 base pairs between the proximal and distal enhancer elements which represses transcriptional activity. This silencer region can also repress the heterologous herpes simplex virus thymidine kinase promoter, which is comparable to the vimentin promoter. In addition, the element is able to function in a position- and orientation-independent manner, and the amount of repression is increased by multiple copies. Here we show by gel retardation assays and DNase I footprinting that this region binds a protein in nuclear extracts from HeLa cells. Southwestern (DNA-protein) blot analysis indicates this protein is approximately 95 kilodaltons in size. Moreover, protein distribution and activity mimic the expression pattern of vimentin during myogenesis, i.e., protein binding increases as vimentin gene expression decreases. The silencer region shares strong sequence similarity with 5'-flanking sequences found in both the human and hamster vimentin genes and with other characterized silencer elements, including the human immunodeficiency virus long terminal repeat, rat growth hormone, chicken lysozyme, and rat insulin genes. Thus, a negative element appears to bind a 95-kilodalton protein involved in regulating the tissue-specific expression of the chicken vimentin gene.
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PMID:A negative element involved in vimentin gene expression. 232 56

The formation of syncytia in cell monolayers infected with a macroplaque strain (MP) of herpes simplex virus was found to be inhibited by hen egg-white lysozyme. Inhibition was roughly proportional to the enzyme concentration. The virus titres in supernatant fluids of lysozyme-treated cultures were also reduced compared with untreated cultures. Control experiments excluded the possibility that lysozyme altered the virus viability and infectivity or impaired cell growth. Since lysozyme is a cationic protein, further experiments were performed in order to discover whether its antisyncytiogenic effect depended on its enzymatic activity or on its positive charge. Inhibition of the MP-induced polycaryocytosis was found to be caused by heat-inactivated lysozyme and three chemically-modified lysozymes with a higher positive charge (one retaining and two lacking enzymatic activity).
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PMID:Cell fusion induced by herpes simplex is inhibited by hen egg-white lysozyme. 255 98

Giant-cell myocarditis is a rare inflammatory disorder characterized by degeneration and necrosis of myocardial fibers and presence of chronic inflammatory infiltrates associated with multinucleated giant cells forming a granulomatous inflammatory reaction. The etiology of giant-cell myocarditis is unknown. Many conditions have been reported as associated with this phenomenon such as fungi, virus, sarcoidosis, and hypersensitivity or autoimmune reactions. We are reporting a case of giant-cell myocarditis discovered in a newborn with congenital herpetic sepsis. The myogenic origin of the giant-cells of this case is supported by the positivity for desmin and myoglobin and negativity for muramidase and alpha-1-antichymotrypsin after immunoperoxidase procedure. The presence of Herpes simplex virus type II was confirmed by indirect immunoperoxidase reaction in most of the viscera including the heart, but is not considered a factor in the production of giant cells.
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PMID:Giant-cell myocarditis in a newborn with congenital herpes simplex virus (HSV) infection: an immunohistochemical study on the origin of the giant cells. 329 30

The chicken lysozyme gene is constitutively active in macrophages and under the control of steroid hormones in the oviduct. To investigate which DNA elements are involved in the control of its expression in macrophages we performed transient DNA transfer experiments with two different types of plasmids: 5'-deletion mutants of the upstream region of the chicken lysozyme gene and different fragments from this area in front of the thymidine kinase promoter (herpes simplex virus), each placed in front of the CAT (chloramphenicol acetyl transferase) coding sequence. Two enhancers (E-2.7 kb and E-0.2 kb) were characterized. They are active in macrophages, but not in chicken fibroblasts. Furthermore a negative element (N-2.4 kb) was identified, which is active in fibroblasts and promyelocytes, but not in mature macrophages. The combined action of all three elements contributes to the observed lysozyme gene activities: no activity in fibroblasts, moderate activity in promyelocytes and high activity in mature macrophages.
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PMID:Lysozyme gene activity in chicken macrophages is controlled by positive and negative regulatory elements. 358 88

Dissection and reconstitution of the adenovirus DNA replication machinery has led to the discovery of two HeLa nuclear proteins which are required in conjunction with three viral proteins. One of these, nuclear factor I (NF-I), recognizes an internal region of the origin between nucleotides 25 and 40 and by binding to one side of the helix stimulates the initiation reaction up to 30-fold. NFI-binding sites have been observed upstream of several cellular genes, such as chicken lysozyme, human IgM and human c-myc, and coincide in most cases with DNase I hypersensitive regions. Here we report the identification of a novel DNA-binding protein from HeLa nuclei, designated NF-III, that recognizes a sequence in the adenovirus origin very close to the NFI-binding site, between nucleotides 36 and 54. This sequence includes the partially conserved nucleotides TATGATAATGAG. NF-III stimulates DNA replication four- to sixfold by increasing the initiation efficiency. Potential cellular binding sites include promoter elements of the histone H2B gene, the human interferon beta gene, the human and mouse immunoglobulin VK and VH genes and the mammal/chicken/Xenopus laevis U1 and U2 small nuclear RNA genes. Furthermore, a subset of the herpes simplex virus immediate early promoter specific TAATGARAT elements is homologous with the adenovirus 2 (Ad-2) NFIII-binding site.
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PMID:Nuclear factor III, a novel sequence-specific DNA-binding protein from HeLa cells stimulating adenovirus DNA replication. 374 45

Cloned complementary DNAs encoding chicken ovalbumin, chicken prelysozyme and calf preprochymosin, prochymosin and chymosin were inserted downstream from various viral promoters in modified recombinant "shuttle" vectors. Microinjection of the ovalbumin, prelysozyme and preprochymosin constructs into the nuclei of Xenopus laevis oocytes resulted in the synthesis, segregation in membranes and secretion into the extracellular medium of ovalbumin, lysozyme and prochymosin, respectively. Judging from molecular weight estimations, lysozyme and prochymosin were correctly proteolytically processed while ovalbumin, which lacks a cleavable signal sequence, was glycosylated. Injection of the DNA construct encoding prochymosin without its signal sequence resulted in synthesis of prochymosin protein that was localized exclusively in the oocyte cytoplasm. No immunospecific protein was detected after injection of the DNA encoding mature chymosin. In terms of protein expression in oocytes, the Herpes simplex thymidine kinase (TK) promoter was up to sevenfold more effective than the simian virus 40 (SV40) early promoter, and equally as effective as the Moloney murine sarcoma virus long terminal repeat element. Where tested, protein expression in oocytes was much reduced if DNA sequences encoding the SV40 small t intron and its flanking sequences were present in the constructs. S1 nuclease mapping of transcripts produced after injection of DNAs containing the TK promoter indicated that the majority of transcripts initiated at, or within, two bases of the known "cap" site. However, minor transcripts initiating upstream from this site were observed and one (or more) of these transcripts was responsible for the synthesis of an ovalbumin polypeptide containing a 51 amino acid N-terminal extension. This extended protein remained in the oocyte cytosol. When ovalbumin cDNA was inserted into the vectors with opposite polarity to the viral promoter, expression in oocytes resulted in the predominant synthesis and secretion of a variant ovalbumin with a 21 amino acid N-terminal extension, although some full-length ovalbumin was also synthesized and secreted. S1 mapping revealed the presence, in these oocytes, of transcripts of predicted polarity initiating 118 bases upstream from the wild type ovalbumin initiator ATG, at a previously unreported SV40 "promoter". No protein synthesis was detected after the injection of these reverse-orientation constructs into baby hamster kidney (BHK-21) cells.
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PMID:Efficient expression of cloned complementary DNAs for secretory proteins after injection into Xenopus oocytes. 609 86

We studied the lysozyme content of tears in 267 subjects (521 eyes), including 241 healthy subjects, 7 patients (14 eyes) with bilateral blepharitis, 8 patients (12 eyes) with conjunctivitis, and 11 patients (16 eyes) with keratitis. The concentration of lysozyme in the tears rises with age between childhood and maturity. The highest values were seen in the age group of 21-40 years, and a decrease of lysozyme concentration occurred with an increase in age from 30-40 years. The mean lysozyme content of tears was 1,768 micrograms/ml in healthy subjects; no significant differences occurred between the sexes. Patients with blepharitis, conjunctivitis, and keratitis had normal mean lysozyme content of tears. The tears of patients with herpes simplex keratitis had low lysozyme values.
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PMID:Lysozyme content of tears in normal subjects and in patients with external eye infections. 665 46


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