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)

The levels of lysozyme in the serum and organs of Shienshilla male rabbits infected with Nico-s treponema were determined. The studies showed that the lues infection affected the factors of non-specific immunity, which was evident from the changes in the lysozyme titer. Administration of benzylpenicillin resulted in a marked decrease in the lysozyme titer in all cases. The experiments are indicative of advisability of studying the use of crystalline lysozyme in combination with antibiotics for increasing the efficacy of therapy of syphilitic infection.
Antibiotiki 1976 Sep
PMID:[Lysozyme content in the serum and organs of rabbits with a syphilitic infection]. 99 68

A possible physiological function of lysozyme might consist of an indirect effect arising in the course of its action on bacteria, as some of the bacterial reaction products behave as adjuvants or immunostimulating substances.
Biomedicine 1976 Sep 30
PMID:A possible physiological function of lysozyme. 100 31

Two cases of the development of acute myeloid leukemia (AML) after treatment with alkylating agents are reported. In Case 1, melphalan and then cyclophosphamide had been given for multiple myeloma. 46 months after onset of cytostatic treatment AML occurred, as confirmed cytochemically and by qualitative determination of urinary lysozyme. In Case 2, cyclophosphamide had been given for rheumatoid arthritis. After a latency of 34 months 'smouldering leukaemia' developed with an atypical monocytic leukaemic cell population. In a third case, multiple myeloma and monocytic leukaemia developed synchronously. The causative role of melphalan and cyclophosphamide in the development of AML seems securely established. Despite the risk of alkylating agents in the treatment of multiple myeloma or Hodgkin's disease causing AML, they should not be replaced, as other drugs have been shown to be less beneficial. On the other hand, alkylating agents should be used with great caution in the treatment of non-malignant diseases.
Dtsch Med Wochenschr 1975 Sep 26
PMID:[Plasmocytoma, alkylating agents, and acute myeloid leukemia (author's transl)]. 105 6

Purified human lysozyme (muramidase) stimulated potassium excretion by the isolated perfused rat kidney. Lysozyme is filtered and reabsorbed, without a tubular maximum. Over 90% of lysozyme filtered is retained within the kidney; 50% was recovered by enzymic assay and histologically localized to the proximal tubular cells. Hypokalaemia seen in some patients with myelomonocytic leukaemia may be directly attributed to an elevated circulating lysozyme level.
J Clin Pathol 1975 Sep
PMID:Effect of human lysozyme (muramidase) on potassium handling by the perfused rat kidney. A mechanism for renal damage in human monocytic leukaemia. 105 11

We have studied the relationship between the determinants encountered by T cells on an antigenic molecule and the specificities of the antibodies eventually produced by the B cells with which these T cells cooperate. The number of epitopes on the hen lysozyme (HEL) molecule available to T cell receptors was functionally limited by inducing T cell tolerance to HEL in rabbits. Highly cross-reactive lysozymes were then used to challenge the HEL-unresponsive rabbits. Only T cells which recognize new epitopes on the challenge lysozymes could act as helpers in generating an anti-lysozyme response. Amino acid differences between Japanese quail lysozyme (JEL) and HEL are segregated within a single quadrant of this small antigen molecule. HEL-tolerant rabbits challenged with JEL produced antibodies which were totally cross-reactive with the tolerogen HEL. This result is in contrast to the result obtained in nontolerant rabbits which produced antibodies to JEL which were only 50-70% cross-reactive with HEL. We conclude that T cells restricted to the JEL-unique epitopes were only capable of cooperating with B cells specific for common epitopes shared between JEL and the tolerogen HEL. Turkey lysozyme (TEL), on the other hand, bears different amino acids which are distributed over several regions on the surface of the molecule. Any one HEL-tolerant rabbit developed a restricted response to TEL; in some rabbits the anti-TEL was highly HEL cross-reactive, while in others little cross-reactivity with HEL was observed. Each of four HEL-tolerant rabbits injected with the minimally altered bob-white quail lysozyme possessed the reactive T cells necessary to mount a limited response to this challenge lysozyme, suggesting a diverse library of T cell specificities. Recognition of the small differences between the challenge lysozymes and the T cells of these tolerant rabbits to make a fine discrimination between minimally changed epitopes.
Eur J Immunol 1976 Sep
PMID:Structural aspects of immune recognition of lysozymes. III. T cell specificity restriction and its consequences for antibody specificity. 108 41

In vivo studies on the attachment of lipoprotein to the murein (peptidoglycan) of Escherichia coli showed that it takes several generations of growth until the amount of lipoprotein on newly made murein is equilibrated. The technique used involves degradation of the sodium dodecyl sulfate-insoluble murein-lipoprotein complex (sacculus, rigid layer) with lysozyme and separation of the labeled products on paper. No lipoprotein was found on murein subunits incorporated during a pulse of [3H]diaminopimelate for 1 min in logarithmically growing cells at 37 C. Even after one doubling of the cell mass, only 4 to 8% of the labeled murein was isolated as bound to lipoprotein. With uniformly labeled murein, 30% remains bound to lipoprotein after lysozyme treatment, corresponding to three murein subunits. Therefore it can be concluded that during pulse labeling either no lipoprotein is incorporated into the newly synthesized murein or no murein subunits are inserted into existing murein around lipoprotein attachment sites. Longer pulse and pulse-chase experiments argue for the latter interpretation. It is therefore concluded that incorporation of murein subunits into the growing murein polymer is not at all a random process. Instead, quite large areas of murein, on which lipoprotein is situated, seem to be preserved. Under the influence of penicillin FL 1060 murein synthesis is 50% inhibited. The rate of lipoprotein attachment is less affected so that increasing amounts of lipoprotein become attached during spheroplast formation. By the time the stationary growth phase has been reached, the lipoprotein content of the murein has doubled. Diaminopimelate auxotrophic mutants require, in the presence of penicillin FL 1060, more diaminopimelate for full growth than in the absence of penicillin FL 1060. This finding and the fact that murein synthesis is always inhibited by 50% over a wide range of penicillin concentration (1 to 1,000 mug/ml) point to the inhibition of an enzymatic step of murein synthesis which can be partially bypassed by a second enzyme, less efficient but resistant to penicillin FL 1060.
J Bacteriol 1975 Sep
PMID:Attachment of lipoprotein to murein (peptidoglycan) of Escherichia coli in the presence and absence of penicillin FL 1060. 109 82

BALB/c mice have been immunized by intravenous administration of native or reduced and alkylated lysozyme. Primary immune response to these antigens was studied at the humoral level (by the Farr assay) and at the cellular level (by the rosette and the plaque assays using lysozyme coupled to sheep or pigeon erythrocytes). Antibodies and theta-negative RFC were specific for the antigen used for immunization. Specific inhibition of theta-negative RFC after incubation with the soluble immunizing antigen confirmed this specificity. Conversely, most theta-positive RFC had double specificity both to native and denatured lysozyme and showed lower avidity for the immunizing antigen, as shown by inhibition studies with soluble antigen. These data suggest that T cells have a broader specificity for lysozyme than B cells and also that, in this particular system, cytophilic antibodies are probably not responsible for the formation of theta-positive rosettes.
Immunology 1975 Sep
PMID:Studies on B- and T-cell receptors for lysozyme. 110 May 19

In Escherichia coli and Salmonella typhimurium, the cell wall that contains both the outer membrane layer and the peptidoglycan layer acts as a barrier of the molecular sieve type for the penetration of uncharged saccharides (G. Decad, T. Nakae, and H. Nikaido (1974) Fed. Proc. 33, 1240). Here we examined which of the layers of the cell wall limited the size of the penetrating molecules, by studying the penetration of saccharides into (a) cells whose peptidoglycan layer had been destroyed by lysozyme treatment or growth in the presence of penicillin and (b) isolated outer membrane vesicles. We found that peptidoglycan-defective cells were similar to intact, plasmolyzed cells in that they allowed a partial penetration of stachyose (molecular weight 666), but essentially excluded saccharides with molecular weights higher than 900 to 1000. We also found that the isolated outer membrane acted as a penetration barrier for saccharides. These observations led us to conclude that the outer membrane, rather than peptidoglycan, sets the size limit for the penetration of uncharged, hydrophilic molecules through the E. coli or S. typhimurium cell wall. The isolated outer membrane, however, had an exclusion limit much higher than that found in intact cells. This "leakiness" could be decreased either by the use of mutants producing extremely deficient lipopolysaccharide, or by trypsin treatment of the isolated membrane followed by heating and slow cooling in the presence of Mg2+. We feel that these observations are consistent with the hypothesis that the resealing of the ruptured outer membrane during the isolation procedure is often incomplete, and that cracks and holes thus generated are responsible for the "leakiness" of the isolated membrane vesicles.
J Biol Chem 1975 Sep 25
PMID:Outer membrane as a diffusion barrier in Salmonella typhimurium. Penetration of oligo- and polysaccharides into isolated outer membrane vesicles and cells with degraded peptidoglycan layer. 110 Jun 25

Factors determining thrombus formation on a foreign surface were studied with the use of plastic flow chambers introduced into extracorporeal shunts. Silicone rubber shunts, joining the carotid artery and jugular vein, were implanted in dogs and remained patent for several weeks. The flow chamber geometry consisted of a 4.8 mm diameter straight tube having a 3.2 X 3.2 mm circumferential cavity in the wall. Chambers were introduced sequentially into the shunts for exposure times of 10 to 30 minutes and regulated blood flow rates of 100 to 400 ml/min. The dry weight of thrombus accumulated in the chamber (5 to 50 mg) was found to increase with exposure time up to 20 minutes and to decrease with increasing flow rate. Various components of the process of thrombus formation were altered by the administration of acetylsalicylic acid, heparin and lysozyme, used alone and in pairs. Heparin was found to be the most effective antithrombotic agent, dry weights of accumulated thrombus being on the order of 50 percent lower when compared to control values. The efficacy of heparin was found to be unaffected by the presence of aspirin and lysozyme, which themselves were not effective antithrombotic agents under the conditions of these experiments. The technique described here may provide a useful animal model for studying the influence of blood flow and different biomaterials on thrombus formation.
Thromb Diath Haemorrh 1975 Sep 30
PMID:Extracorporeal model for study of factors affecting thrombus formation. 110 56

The complement component, C5a provokes the selective release of granule-associated enzymes from the intact, viable cytochalasin B-treated human polymorphonuclear leukocytes (PMN) in the absence of phagocytosis or cellular adherence to surfaces. Consquently, in this experimental system the influence of divalent cations on these two processes can be disregarded and their effects on enzymes secretion can be studied directly. Cytochalasin B-treated PMN exposed to C5a in calcium and magnesium-free media consistently secreted significant amounts of the granule-associated enzymes, beta-glucuronidase and lysozyme. The basal secretory response was not diminished if cells were preincubated with 5.0 mM EDTA, nor was it influenced if 1.0 mm or 2.0 mM EDTA were present in the reaction mixtures. The addition of calcium (up to 1.5 to 2.0 mM) produced a concentration-dependent enhancement of beta-glucuronidase release, whereas increasing amounts of calcium (above 2.0 mM) inhibited secretion of this enzyme. Lysozyme release was similarly enhanced by the addition of calcium, but inhibition with high concentrations was not observed. Calcium per se, in the absence of C5a, provoked only the release of lysozyme from these cells. The effects of calcium upon enzyme release were not associated with alterations in the state of assembly of cytoplasmic microtubules. These findings provide another example of the role of calcium in "stimulus-secretion coupling" and provide evidence that exocytosis of various granules in human PMN is regulated by independent mechanisms involving calcium.
J Immunol 1975 Sep
PMID:Influence of divalent cations upon complement-mediated enzyme release from human polymorphonuclear leukocytes. 115 Oct 72


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