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)

A unique type of Ag-specific hypersensitivity was induced by challenging the Ag-sensitized mice at the ear. It was elicited within 1 h after the Ag challenge, and thus was distinct from either the delayed-type hypersensitivity (DTH) which developed in 24 h or the immune complex-mediated hypersensitivity which evolved in 4 to 6 h. This hypersensitivity was referred to as early-type hypersensitivity (ETH). The time required for these types of hypersensitivity to develop after immunization was also different; DTH required 4 to 6 days, ETH 9 to 11 days, whereas plasma protein-induced immune complex-mediated hypersensitivity needed 18 to 21 days. The ETH could be induced by a smaller amount of Ag than DTH, and unlike DTH could be transferred by either immune sera or T cell-derived culture factor which was small m.w. Although the ETH developed later than DTH after sensitization, it lasted longer once developed and the pattern of response was inversely related to DTH. Furthermore, the denatured hepatitis B surface Ag induced DTH but not ETH, in contrast to native hepatitis B surface Ag that induced both, suggesting that the epitopes recognized by TETH cells were distinct from those recognized by TDTH cells. The ETH could be induced by most Ag tested including poly(Glu60Ala10Tyr10, L-lactic dehydrogenase, insulin, chicken egg white lysozyme, polymerized human serum albumin, horse gamma-globulin, transferrin, fibrinogen, and plasminogen, but not by purified protein derivative. Because poly(Glu60Ala10Tyr10, L-lactic dehydrogenase, egg white lysozyme and insulin were under the Ir gene control and the inducibility of ETH was Ag dependent and was closely correlated with that of DTH, the expression of ETH also must be regulated by Ir gene. The histopathologic changes in ETH consisted of capillary congestion and edema. The vasopermeability was increased and there was the leakage of plasma proteins into the tissue. Based on these data, we concluded that the ETH reported in this study was a novel type of Ag-specific hypersensitivity.
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PMID:An antigen-specific hypersensitivity which does not fit into traditional classification of hypersensitivity. 247 37

Alveolar macrophages are the primary cells that protect the lung against inhaled or aspirated microbes. They kill microorganisms intracellularly by both oxidative and non-oxidative mechanisms. Alveolar macrophages secrete antimicrobial factors, including lysozyme, peptides, and transferrin, which are found in the bronchoalveolar lining fluid and may kill microbes extracellularly. Macrophage secretory products help initiate a controlled inflammatory response and a limited influx of granulocytes, which appears to be important for complete elimination of many bacterial pathogens from the lung.
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PMID:Role of leukocytes in lung defenses. 268 73

The protein content of normal human tears from five subjects was examined by molecular weight separation using SDS-polyacrylamide gel electrophoresis (PAGE) and by charge separation using agarose isoelectric focusing (IEF) gels. After separation, specific proteins were identified by immunoblot and immunofixation. Tear proteins examined included albumin, IgA, IgG, prealbumin, lactoferrin, lysozyme, secretory component and transferrin. These techniques required 1 to 14 microliters unconcentrated tears. We found SDS-PAGE superior to agarose IEF to examine total tear protein pattern, and silver stain almost ten-fold more sensitive than Coomassie blue stain. Immunologic staining markedly enhanced protein detection in all tear samples and appeared to offer the definitive method to probe for a specific protein in tears. In this study prealbumin and a portion of the IgG were present in normal tears at higher than expected molecular weight, suggesting they were present in complexed form. Prealbumin and secretory component staining showed marked variability between subjects. These techniques should be applicable to examine tear proteins in a variety of ocular disease states.
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PMID:Electrophoresis combined with immunologic identification of human tear proteins. 275 2

The effect of calcitriol on the induction of differentiation in human promyelocytic leukemic cell line (HL-60) cultured in serum-free chemically defined medium (SFM) was investigated. The utilization of SFM containing RPMI-1640 basal medium supplemented with insulin (5 micrograms/ml), transferrin (5 micrograms/ml), sodium selenite (5 ng/ml), and bovine serum albumin (0.5 micrograms/ml), transferrin examination of the cellular/molecular mechanism of calcitriol's action in HL-60 cell differentiation without interference of components present in serum. HL-60 cells grown in SFM were induced to differentiate into monocytes/macrophages by calcitriol as indicated by induction of differentiation-associated biological and biochemical parameters: chemiluminescent (CL) responsiveness, lysozyme activity, nonspecific esterase, expression of cell surface antigens, and reduced proliferation. The exposure of HL-60 cells in SFM to calcitriol (from 10(-10) to 10(-8)M) resulted in dose-dependent induction of these parameters, which was similar to those obtained with cells grown in 10% fetal calf serum containing medium (10% SCM). However, calcitriol was 5-fold more potent for HL-60 cells cultured in SFM than those cultured in 10% SCM as indicated by shifts in dose-response curves for induction of CL responsiveness and lysozyme activity. The effect of calcitriol on the proliferation and acquisition of several monocyte-associated cell surface antigens was also more sensitive for HL-60 cells cultured in SFM than for cells grown in 10% SCM. We characterized and quantitated calcitriol receptors in HL-60 cells cultured in SFM in comparison to those in 10% SCM after exposing intact cells to radiolabeled calcitriol. Cells cultured in either SFM or 10% SCM exhibited calcitriol receptors that migrated at 3.4S as a single peak on sucrose gradients and elicited inherent DNA binding ability. There was essentially no difference in the apparent dissociation constants (Kd) nor in the number of calcitriol binding sites per HL-60 cell, that is approximately 6.0 X 10(-11) M and approximately 3000 binding sites/cell respectively. It is concluded that culturing HL-60 cells in SFM results in full expression of calcitriol-induced phenotypic changes excluding the possibility that such changes result from the indirect effect of calcitriol mediated by identified and/or unidentified components present in serum.
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PMID:Induction of monocytic differentiation by calcitriol (1,25-dihydroxyvitamin D3) in the human promyelocytic leukemic cell line (HL-60) in serum-free medium. 282 7

Pulmonary clearance of inhaled pneumococci is markedly impaired in neonatal rats compared with that in adult rats. To determine whether this impairment is due to a deficiency of extracellular bactericidal factors, the antipneumococcal activity of free fatty acids (FFA) in lung surfactant and the levels of lysozyme and transferrin in lavage fluids were quantified. Surfactant from adult rats averaged 68 U of antipneumococcal activity per g (dry weight) of lung, compared with less than 0.25 U for rats less than 1 week old (P less than 0.001). The kinds of FFA in surfactant of neonatal and adult rats were essentially identical, and the antipneumococcal activity of highly purified FFA from surfactant of neonatal and adult rats was also the same. However, the quantity of FFA in surfactant varied significantly with age, and rats less than 3 weeks old had much lower levels of surfactant FFA than did adults (P less than 0.001). In addition, lavage fluids from neonatal rats inhibited the antipneumococcal activity of surfactant FFA more than lavage fluids from adults did (P less than 0.02). This inhibitory activity did not appear to be due to protein binding. Lavage fluids from neonates showed an age-related deficiency of lysozyme (P less than 0.001), but lysozyme appeared to play no role in pneumococcal killing by the surfactant fraction of lavage fluids in vitro. Transferrin levels in lavage fluids were similar for neonates and adults. It was concluded that lung surfactant from neonatal rats was deficient in antipneumococcal activity, due mostly to low levels of FFA and to a lesser degree to increased levels of inhibitor(s) in lavage fluids.
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PMID:Impaired antipneumococcal activity of bronchoalveolar lining material of neonatal rats. 291 94

The antigenic and functional properties of splenic sinusoidal lining cells (SLC) have not been studied extensively. Some investigators have suggested that SLC are actively phagocytic, and thus part of the mononuclear phagocyte system. Others dispute this and assign the functions of endothelial cells to the SLC. During studies in situ of phenotypic subpopulations of human splenic macrophages (M phi), we found that SLC share membrane antigens (HLA-DR and OKM5), an enzyme (lysozyme), and histochemical properties (nonspecific esterases) with monocytes and M phi. In addition, we showed that LSC, like endothelial cells, synthesize factor VIII of the clotting system and also bear the receptor for transferrin. Our previous studies found that SLC express the antigens found on helper/inducer (OKT4, Leu-3a,b) and suppressor/cytotoxic (OKT8, Leu-2a) T lymphocyte subsets. We have confirmed these observations, and have shown by means of preincubation with soluble complexes of anti-human IgG-human IgG that the detection of T cell and other antigens on SLC is not due to nonspecific binding of antibodies by Fc receptors. By using techniques designed to isolate and purify splenic M phi, we were able to obtain SLC in suspension and to demonstrate that they retain the antigens detected in situ. Thus, the human splenic SLC expresses a unique combination of antigens, histochemical properties, and cell products in common with monocytes, M phi, and T lymphocytes.
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PMID:Human splenic sinusoidal lining cells express antigens associated with monocytes, macrophages, endothelial cells, and T lymphocytes. 298 44

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

The state of pregnancy changes the immune system by allowing the trophoblast to go on developing without letting the mother's body be invaded by it, and by keeping intact immune defences against the usual assaults. The non specific immune system is the first bulwark against invaders. The elements of this system, which do not depend on immunological memory, are: the macrophage-monocyte system, Natural Killer cells (NK), the complement component and other bactericidal substances such as lysozyme, fibronectin and interferon. Pregnancy improves the working of the monocyte-macrophage system. In fact, the macrophages of th reticulo-endothelial system, which can be found in different strategic places in the body, phagocytose abnormal particles more intensely. The monocytes in the circulation are more aggressive in pregnancy. They are drawn to the feto-placental interface where they are activated by different lymphokines and cytokines which can be found in quantity at this site. The role of these local active monocytes is not limited only to phagocytosis because among the hundred substances that they can elaborate are some that will regulate trophoblastic proliferation. The activity of the Natural Killer cells that are circulating and which can control tumour cell growth and cells infected by viruses is lowered in pregnancy. The serum taken from pregnant women seems to have a substance that counters the maturation of the Natural Killer cell lines. The complement system of protein synthesis, which normally acts to lyse bacteria in the chemotaxis during opsonisation, is raised in pregnancy. At the feto-placental interface it does seem to activate this system but not elsewhere in the general circulation. Interferon, which is a molecule that normally activates NK cells, has been found at the feto-placental site, without seeming to have a particular role. Pregnancy changes the quantity and the distribution of other elements in the non specific immune system such as transferrin , fibronectin and beta-lysin.
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PMID:[Non-specific immune defenses present in pregnancy]. 306 97

A cohort of 66 workers professionally exposed to vinylchloride (VC) in a plant producing polyvinylchloride was examined in years 1979 and 1985 by same methods. Significant changes of the levels of immunoglobulins (Ig), lysozyme and transferrin were not observed during the six years in the subgroup of smokers. Nevertheless a highly significant rise of alpha 2 macroglobulin (A2M) and ceruloplasmin (CPL) levels in this subgroup was stated. The levels of IgA and IgM significantly rose in the subgroup of ex-smokers, as well as highly significant increase of A2M was noted in this subgroup. The levels of IgG and A2M rose with highly significance in the subgroup of non-smokers; the CPL increase was only of weak significance. Many significant differences in means were assessed between subgroups of exposed workers and age matched control persons. No significant correlation between the levels of the tests and the time of exposure to VC was observed by regression analysis. In the discussion an opinion about possible premature aging of persons exposed to VC was brought forward.
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PMID:Humoral factors of resistance in the cohort of workers exposed to vinylchloride in the span of six years, concerning the influence of smoking. 310 87

Amniotic fluid obtained from normal full term gestation inhibited the growth of E. coli, Staph. aureus and B. subtilis, while Ps. aeruginosa, Str. faecalis and Str. agalactiae proliferated readily in amniotic fluid. But when amniotic fluid was heated at 100 degrees C for 5 minutes, its antibacterial activity was completely lost. The levels of transferrin and lysozyme in amniotic fluid at term were determined to be 29.1 +/- 17.6 mg/100 ml (n = 90) and 19.1 +/- 8.3 micrograms/ml (n = 145), respectively. Antibacterial activity against E. coli was restored by adding transferrin into heat-treated amniotic fluid at a concentration of 250 mg/100 ml or higher, but simultaneous addition of transferrin and sufficient concentration of iron to form a transferrin-iron complex resulted in the loss of antibacterial activities. When lysozyme was added to the amniotic fluid, which had lost its antibacterial activity through exposure to heat, the antibacterial effect on B. subtilis was restored. The growth of Staph. aureus in heat-treated amniotic fluid was inhibited by the concomitant addition of lysozyme and aminobenzyl penicillin.
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PMID:The effect of transferrin and lysozyme on antibacterial activity of amniotic fluid. 310 22


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