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)

We examined biochemically the effect of six aminoglycoside antibiotics on the activity of lysozyme, acid phosphatase, and N-acetyl-beta-D-glucosaminidase in human tears. All six antibiotics strongly inhibited lysozyme activity, the degree of inhibition depending on the dose administered. Except for bekanamycin, antibiotics had little effect on the activity of acid phosphatase or N-acetyl-beta-D-glucosaminidase. The nature of the inhibition was competitive. Other kinds of antibiotics, such as sulbenicillin or erythromycin, had no inhibitory effect on lysozyme, acid phosphatase, or N-acetyl-beta-D-glucosaminidase. These results suggested that the inhibition of lysozyme by aminoglycosides is specific and that the decreased effectiveness of a protective system against bacterial infection in the eye is highly possible when aminoglycoside antibiotics are used without prior sensitivity testing.
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PMID:Aminoglycoside antibiotics and lysosomal enzymes of human tears. 406 44

In animals developing experimentally induced unilateral pyelonephritis, both the infected kidney (IK) and the contralateral noninfected kidney (NIK) showed an immediate increase in renal lysozyme activity of about 5 days' duration after the unilateral injection of viable Proteus mirabilis into the renal cortex. Lysozyme activities of the NIK were consistently higher than those of the IK. This initial increase was followed by a second increase which lasted throughout the period of observation (17 days), and enzyme activities of the NIK were consistently higher than those of the IK. In saline punctured kidneys of control animals, both the saline punctured kidney (SP) and the non-saline punctured kidney (NSP) showed only the immediate increase in renal lysozyme activity, which persisted until the SP was completely healed. These enzyme activities were less than those observed in the infected animals, but the response of the NSP was greater than that of the SP. Trauma not directed to the kidney does not produce a similar response of renal lysozyme. The elevated renal lysozyme of the NIK could not be shown to protect it from bacterial infection.
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PMID:Renal lysozyme levels in animals developing Proteus mirabilis-induced pyelonephritis. 554 3

A chronic infiltration of polymorphonuclear leukocytes was invariably found in the infertile regions of uteri containing foreign bodies in conventional rats, germfree rats, mice, and rabbits. Polymorphonuclear leukocytes were never found in the fertile regions of these uteri. A foreign body in the uterus of the rat, and probably also the mouse, was associated with a bacterial infection which spread the inflammatory response throughout the horn containing the foreign body, and in the mouse occasionally into the control horn as well. No bacteria could be cultured from the rabbit uterine horn containing a foreign body. In the germfree rat, both the infiltration of polymorphonuclear leukocytes into the uterus and fertility were significantly different from that observed in the conventional rat. Whereas in the conventional rat the inflammation and infertility extended along the entire length of the uterine horn containing a small foreign body, in the germfree rat the inflammation and infertility were closely correlated to the position of the foreign body. As judged by measurements of lysozyme in the uterine lumens of rats and rabbits, polymorphonuclear leukocytes released their contents into solution in the uterine lumen. It is concluded that some substance derived from polymorphonuclear leukocytes may exert toxic effects on fertilized ova or on spermatozoa and thus be responsible for the infertility of uteri containing foreign bodies.
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PMID:The relationship of polymorphonuclear leukocytes to infertility in uteri containing foreign bodies. 603 52

The attacins are antibacterial proteins which accumulate in the hemolymph of the giant silk moth, Hyalophora cecropia, in response to a bacterial infection. Here we show that the permeability barrier function of the outer membrane is affected shortly after addition of attacin to growing cultures of Escherichia coli. Specifically, the penetration through the outer membrane of beta-lactam antibiotics, chicken egg white lysozyme and the detergent Triton X-100 was found to be facilitated. The sensitivity of E. coli to cecropin B, another antibacterial protein present in the hemolymph of H. cecropia, was also found to be increased after treatment with attacin. The results suggest that the target of the attacins in E. coli is the outer membrane. Other effects of the attacins which have been observed are likely to be indirect consequences of the alteration in the properties of the outer membrane. These effects include changes in the cell shape, irregular patterns of cell division and lysis. The minimal concentration at which the attacins affected the growth of E. coli was 1 and 0.5 microM for the neutral (pI 7) and basic (pI 9) attacins, respectively, which corresponds to less than 2% of the concentration of the attacins in the hemolymph of infected pupae.
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PMID:The antibacterial effect of attacins from the silk moth Hyalophora cecropia is directed against the outer membrane of Escherichia coli. 639 89

From the clinical and experimental studies, the following results were obtained. The serum lysozyme activity decreased postoperatively and returned to the preoperative level 2 weeks later. Postoperative changes of the activity reflected the state of surgical stress inflicted on the subjects, namely, the changes were parallel to the degree of the stress and their postoperative courses. The postoperative elevation of lysozyme activity in anastomosed colonic tissues or abdominal walls, in which the activity was not determined preoperatively was supposed to be a reasonable phenomenon and closely related to tissue regeneration or protection from bacterial infection. The mechanism of this local elevation should be due to migration from the peripheral blood and movement of the lysozyme-producing or -secreting cells to the wounds. The phagocytic activity of peritoneal macrophage hyperfunctioned postoperatively. This might suggest lysozyme synthesis or secretion by peritoneal macrophage and participate in the protective action of the subjects. The postoperative serum lysozyme activity was maintained at the normal level by preoperative peroral administration of egg-white lysozyme preparation, therefore, the administration was thought to be very effective to the acceleration of protective action of the subjects on whom the surgical stress was imposed.
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PMID:[Studies on changes of lysozyme activity during pre- and postoperative periods in alimentary tract surgery]. 649 82

To investigate the effects of strenuous forced exercise on the course and complications of a bacterial infection and on myocardial responses and performance capacity, rats with tularemia (characterized by pyogranulomatous hepatic and splenic lesions) were exercised by swimming on days 0-6 of infection. Levels of glutamic oxaloacetic and pyruvic transaminases in plasma, densities of pyogranulomatous lesions, and bacterial counts in blood, liver, and spleen were similar in exercising and resting rats. Although a few exercising rats showed an unusual dissemination of infection, the antibody responses were similar in rest and exercise. Plasma concentrations of beta-glucuronidase, lysozyme and alpha 2-macrofetoprotein were higher with exercise, a result that indicated that more vigorous stress responses were elicited with exercise than with infection alone. Physical performance capacity was reduced by the infection, but forced daily exercise limited this reduction substantially and counteracted the myocardial protein-degrading effects of infection. Thus, exercise evoked normal training responses even during this generalized infection.
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PMID:The effects of strenuous exercise on infection with Francisella tularensis in rats. 707 93

The activity of lysozyme in saliva and serum was determined in 51 patients with cystic fibrosis. Measurements were made on two occasions at least 1 month apart and compared to those of 25 normal healthy individuals of the same ages, sex, and race. The mean serum lysozyme activity of normal individuals was 5.8 micrograms/ml (S.E. = 0.4), whereas that of cystic fibrosis patients was 10.8 micrograms/ml (S.E. = 0.5). The difference is significant (P less than 0.05). Initial mean values compared to those of repeated samples from the cystic fibrosis group were similar, whereas individual fluctuations occurred between test periods. The mean lysozyme activity of the saliva sample of normal individuals was 63.5 micrograms/ml (S.E. = 9.3) and the mean value from cystic fibrosis patients was 82.7 (S.E. = 6.9). This difference was not significant (P greater than 0.1). Mean values from specimens obtained a month or longer after the initial saliva samples were similar for the two episodes. There was no correlation between the serum and salivary values and the age, sex or race of the subjects, the Shwachman-Kulczycki scores, colonization with Pseudomonas aeruginosa, Staphylococcus aureus or Haemophilus influenzae or absolute white blood cell counts. In vitro studies failed to demonstrate bactericidal activity for mucoid and nonmucoid strains of P. aeruginosa or for S. aureus. Elevated lysozyme activity in cystic fibrosis may be related to either an increased granulocyte turnover because of chronic bacterial infection of the respiratory tract or to a basic defect in the lysosomal membrane allowing an increased release of the enzyme, or a combination of both.
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PMID:Lysozyme activity in cystic fibrosis. 714 10

Incubation of lysozyme with acetaldehyde (0.44 M) at room temperature for 2 h produces a 62% inhibition of enzymic activity. Because the active site cleft contains tryptophyls, asparagine, glutamine, and an arginine residue, and because acetaldehyde reacts with indoles, amides, and guanidines, it is suggested that these sites are likely ones for alkylation. The epsilon-amino groups of lysines on the surface of the molecule are also susceptible to covalent modification. Total acetylation of lysozyme has been reported to inactivate the enzyme. These results suggest the possibility that inactivation of a fraction of the lysozyme activity by acetaldehyde may decrease the effectiveness of the enzyme in chronic alcoholics, thereby leading to an increased potential for susceptibility to bacterial infection.
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PMID:Acetaldehyde-modified lysozyme function: its potential implication in the promotion of infection in alcoholics. 777 70

A patient with a bacterial infection is usually cured by his own defense mechanisms against the infectious agents. However, defense mechanisms are frequently damaged by physiologic factors. In this chapter, we described the important physiologic factors which weakened defenses of urinary, respiratory or alimentary tracts and others against bacterial infection. For example, defects of the skin or mucosa is one of the most important factors, because these tissue have natural defense which are low pH, keratin, normal bacterial flora, lysozyme, lactoferrin, secretory IgA and so on. Foreign bodies, urinary or vascular catheters or stones damage normal defenses of mucosa or vascular wall. Many species of bacteria make biofilm, which is consisted of grown bacteria, glycocalyx matrix, fibrin and platelets, around the foreign bodies or catheters. This matrix substance have characteristic of an ion exchange filter which traps aminoglycoside antibiotics, and beta-lactam antibiotics are not effective in the biofilm because of lower growth rate. Furthermore, obstruction of urinary, respiratory or alimentary tracts is also important factor because of decrease of clearance of bacteria from these tissue by urine stream, pilial or bowel movement, and decrease of perfusion of antimicrobial agents from blood stream to the tissue.
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PMID:[Physiologic factor in intractable bacterial infections]. 812 79

Endotoxin (lipopolysaccharide [LPS]) released during gram-negative bacterial infection induces varieties of cytokines which directly and/or indirectly cause shock, disseminated intravascular coagulation, and death. We previously showed that lysozyme (LZM) was an LPS-binding protein and inhibited various immunomodulating activities of LPS. In this study, we examined the effect of LZM on the LPS-triggered septic shock model induced by carrageenan treatment and assessed by tumor necrosis factor production. The data presented in this report strongly suggest that LZM-LPS complex formation completely abrogates tumor necrosis factor production and the mortality caused by LPS and that LZM may be useful for the treatment of endotoxin shock.
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PMID:Binding of lysozyme to lipopolysaccharide suppresses tumor necrosis factor production in vivo. 813 23


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