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

---

Query: EC:2.7.10.1 (ERK)
95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxins (SE) A, B, and C were studied on binding to rabbit spleen cells. The toxins showed remarkable mitogenic effects on the cells. Among them, SEA and TSST-1 had much stronger mitogenic activities than SEB and SEC. Binding study showed that labeled TSST-1 and SEA bound considerably to cells, but that labeled SEB or SEC was not observed to bind at a detectable level under the same conditions as TSST-1 and SEA. Competitive binding analysis between toxins to cells proved that TSST-1 and SEA clearly competed with each other in binding. Scatchard plots for TSST-1 and SEA in binding were linear at the doses used. The Scatchard analysis for TSST-1 and SEA gave a dissociation constant of 2.5 X 10(-9) M and 7.6 X 10(-8) M and the number of binding sites per cell of 5.3 X 10(3) and 1.0 X 10(5), respectively.
...
PMID:Bindings of toxic shock syndrome toxin-1 and staphylococcal enterotoxins A, B, and C to rabbit spleen cells. 275 62

Several observations suggest that staphylococcal enterotoxins A, B and C (SEA, SEB and SEC, respectively), in addition to toxic shock syndrome toxin-1 (TSST-1), are causative exotoxins of toxic shock syndrome (TSS). Based on the view that polyclonal T cell activation with the causative exotoxins, resulting in over-production of lymphokines, is involved in the development of the pathological changes observed in TSS, we investigated the activities of these four exotoxins to induce proliferation and interleukin 2 production in murine and human lymphocytes by using in vitro culture systems. The results showed that all these exotoxins are strong polyclonal inducers of proliferation and interleukin 2 production in human T cells, whereas TSST-1 and SEA are strong and SEB and SEC are weak polyclonal inducers in murine T cells. These results suggest that SEA, SEB and SEC, in addition to TSST-1, are possibly involved as causative exotoxins in the development of the pathological changes observed in TSS.
...
PMID:Relative strength of the mitogenic and interleukin-2-production-inducing activities of staphylococcal exotoxins presumed to be causative exotoxins of toxic shock syndrome: toxic shock syndrome toxin-1 and enterotoxins A, B and C to murine and human T cells. 278 35

A group of 596 Staphylococcus aureus strains isolated from various clinical sources or implicated in food poisoning was investigated for enterotoxins A and B (SEA and SEB) production. The conventional ELISA techniques (competitive and sandwich ELISA) were compared with a newly developed avidin-biotin ELISA in their ability to detect the enterotoxins. The avidin-biotin system was not remarkably influenced by SPA up to 10 micrograms/ml. A semi-quantitative competitive ELISA for the detection of staphylococcal protein A (SPA) in culture supernatants was carried out in parallel. The strains isolated in cases of food poisoning showed different antibiotic resistance patterns, whereas the strains from clinical sources were selected for either methicillin or penicillin resistance only. The strains isolated in food poisoning outbreaks (FP strains) were enterotoxin A positive in 22%, enterotoxin B positive in 11%, and SEA + SEB positive in 9% of cases. The strains with resistance to penicillin only (PER strains) produced SEB in 26%, SEA in 14%, and both toxins in 7% of the cases. The methicillin-resistant strains (MCR strains) produced SEA in 59% of cases, whereas SEB was produced in 6% only (SEA + SEB: 20%). 37% of the SEA producers belonged to phage group III (SEB: 30%; SEA + SEB: 25%) and 12% (SEB: 11%; SEA + SEB: 9%) to phage group I. 26% of the SEA-producing and 37% of the SEB-producing strains (SEA + SEB: 23%) were non-typable.
...
PMID:Correlation between enterotoxigenicity, tested by different ELISA-techniques, antibiotic resistance patterns and phage groups of Staphylococcus aureus strains. 296 8

The effects of staphylococcal enterotoxins A, B, and C2 (SEA, SEB, and SEC2) on the resistance of mice to microbial infections were studied. SEA stimulated the resistance strongly, whereas SEB and SEC2 had no such effect. Treatment with SEA increased the number of peripheral blood polymorphonuclear leukocytes significantly within 4 h, and these polymorphonuclear leukocytes exhibited a higher chemiluminescence response than those of the controls. Furthermore, a significant increase in spleen weight was also observed in mice treated with SEA, and histologically that increase was characterized by a proliferation of lymphoblast-like cells which were stained with antibody to mouse Thy-1 but not with antibody to mouse immunoglobulin G by indirect immunofluorescence. As expected from the above findings, the treatment of nude mice (nu/nu) with SEA failed to protect them against Escherichia coli infections, whereas treatment of heterozygous (nu/+) controls afforded such protection. This was in part supported by the fact that the chemiluminescence response of peripheral blood polymorphonuclear leukocytes was increased significantly by treatment with SEA in nu/+mice but not in nu/nu mice.
...
PMID:Stimulation by staphylococcal enterotoxin A of nonspecific resistance of mice to microbial infection. 388 67

The competitive ELISA (polystyrene balls) with labeled antigen according to Stiffler-Rosenberg and Fey (1978) was applied to the analysis of Staphylococcal enterotoxins (SE) A, B and C in food to see if the enterotoxin concentration corresponding to maximum limit for SEA and SEB (1 ng/g food and 10 ng/g food respectively) could be measured. The effect of various food ingredients on the quantitative determination of SE in single-step and two-step variants of competitive ELISA was investigated. Generally, the effect of food was the lowest in extracts of cheeses and the highest in extracts of meats and pasta products. All enterotoxins were equally affected. However, within the same type of food significant differences in binding of both labeled and unlabeled antigen were found. The effect of food components often depended on the assay variant; the extracts of cheese gave better results in the two-step and the extracts of pasta better results in the single-step ELISA. In some weak-positive extracts, false positive results could not be excluded. In the samples of cheese which were involved in food poisoning exclusively the enterotoxin type A was found (up to 30 ng/g). The recovery of added SE (1-10 ng/g food) ranged from 50-70% in cheese and was about 70% in pasta foods. The assay sensitivity in buffer ranged from 0.2 ng/ml for enterotoxins A and B and 0.3 ng/ml for enterotoxin C (20 ml sample) to 0.5 ng/ml for A and B and 0.6 ng/ml for C (5 ml sample) to 1 ng/ml for A and B and 2 ng/ml for C (1 ml sample). In food, especially in meat and pasta the detection limit was often higher. With some exceptions the required sensitivity for enterotoxin A (1 ng/g) could only be reached in cheese.
...
PMID:[Determination of staphylococcal enterotoxins A, B and C in foods using ELISA with labeled antigen]. 409 49

The production of alpha, beta and gamma interferons (IFN) and interleukin 2 (IL-2) by Lyt-2+-dependent cytotoxic T-cell lines/clones was investigated. Cloned and uncloned T-cell lines specific for H-2Dd or the unique RL male 1 leukemia antigen were studied. After infection with Sendai virus (SV) or Newcastle disease virus (NDV) all cell lines produced IFN-alpha and -beta. Induction of IFN-gamma was attempted with the mitogens Con A, PHA, PWM, SEA, and SEB, with poly(I:C), with antibodies Lyt-1.2, -2.2, and Thy-1.2, or with the target cells Meth A (H-2Dd+) and RL male 1. All mitogens were effective inducers. However, the antibodies and poly(I:C) were not. One uncloned RL male 1-specific cell line CTLL-RP, produced IFN-gamma after induction with RL male 1. Production of IFN-alpha, beta depended on IL-2, whereas production of IFN-gamma did not, although addition of highly purified IL-2 increased IFN-gamma production even in the absence of other inducers. Crude IL-2 inhibited the production of IFN-gamma but not IFN-alpha, beta. In response to mitogens, some T-cell clones also produced IL-2. The results demonstrate that Lyt-2+ cells can produce a broad spectrum of lymphokine activities after appropriate stimulation. Their availability now affords us the opportunity to study the regulation of lymphokine production at the clonal level.
...
PMID:Characterization of interleukin 2-dependent cytotoxic T-cell clones. IV. Production of alpha, beta and gamma interferons and interleukin 2 by Lyt-2+ T cells. 619 26

340 S. aureus strains, isolated either from routine food test samples, or from food leftovers, from healthy or sick persons in cases of suspected food poisoning in various places of the Federal Republic of Germany, were tested for enterotoxin production. The enterotoxin types A, B and C (SEA, SEB and SEC) were determined both by the ELISA and the microslide test (MS-test), the enterotoxin types D and E by the MS-test only. Comparison of the two test methods clearly shows that the ELISA technique is superior to the MS method: The sensitivity of the ELISA was at 2.5 ng, whereas that of the MS-test was limited to approximately 1 microgram. The ELISA revealed 6.2% more of the strains as enterotoxin producers, and reproducibility of the test results was also better with the ELISA than with the MS-test. Furthermore, the ELISA is far more efficient, consuming less test reagents, and with a capacity for testing more strains in a shorter time procedure. The incidence rate of the various enterotoxin types, referred to one representative strain each per outbreak of food poisoning or group of persons investigated, is as follows: 45.3% SEA, 17.2% SEB, 23.4% SEC. The incidence rate of SED, SEE or SE-type combinations was less than 5%. In sick persons, SEA- and SEC-producing strains occurred within the same range, i.e. 34.8% and 30.4% respectively. SEA-producing S. aureus strains had the highest frequency in food samples (61.5%) and in healthy individuals (53.6%).
...
PMID:[Demonstration of enterotoxin in Staphylococcus aureus cultures by the ELISA test and the microslide test]. 640 34

Milk samples from 251 nursing mothers were screened for enterotoxigenic staphylococci. The incidence of staphylococci in milk samples was 71.3%. Two hundred and sixteen strains were isolated from 179 mothers. Eighty-six (39.8%) of the 216 strains were found to be toxigenic. Enterotoxin type A (SEA) predominated, with 41 strains (19.0%) elaborating it. Twenty-one strains (9.7%) produced enterotoxin B (SEB) while only eight (3.7%) produced enterotoxin C (SEC). Ten strains (4.6%) produced all three types. Enterotoxigenic strains usually produced coagulase, thermonuclease and alpha haemolysin. In this series breast-feeding alone was more common than combined breast and bottle feeding, especially among mothers less than 30 years old. The incidence of reported infantile diarrhoea decreased with increasing age of the mother. Of 16 babies with diarrhoea, 10 (62.5%) had mothers whose milk yielded staphylococci. Six of these were toxigenic. Although no direct relationship between enterotoxigenic staphylococci in the milk of nursing mothers and infantile diarrhoea could be demonstrated, these findings reveal a potential health risk to these infants.
...
PMID:Frequency of isolation of enterotoxigenic staphylococci from milk of nursing mothers in Kaduna, Nigeria. 651 54

The ability of 309 staphylococcal isolates from household dogs to produce enterotoxin, coagulase, thermonuclease and hemolysin was investigated. A total of 52 (16.8%) isolates from 45 out of 150 dogs examined were enterotoxigenic when tested for enterotoxin types A, B and C. Based on sites sampled, 33 (20.5%) out of 161 isolates from the anterior nares were enterotoxigenic while from dorsal skins 19 (12.8%) out of 148 isolates were enterotoxigenic. Staphylococcal enterotoxin C(SEC) was predominantly produced as 21 (6.8%) isolates elaborated it and also accounted for 40.4% of all enterotoxins produced by isolates. Staphylococcal enterotoxins A(SEA) and B(SEB) were produced by 10 (3.2%) and 16 (5.2%) strains, respectively. Mixed enterotoxin types AB, AC and BC were produced by 1,3 and 1 strains, respectively. With human plasma, 17.1% of coagulase-positive and 15.0% of coagulase-negative strains were enterotoxigenic. However, using canine plasma, 19.1% and 6.9% of the coagulase-positive and negative isolates, respectively, were enterotoxigenic. The incidence of enterotoxigenicity was 16.9% amongst thermonuclease-positive isolates and 16.3% for thermonuclease-negative strains. Alpha hemolysin was predominantly produced by 180 (60.2%) isolates and 19.9% of these were enterotoxigenic. Beta hemolysin was produced by 36 (11.7%) isolates with 13.9% enterotoxigenic, while 87 (28.2%) exhibited gamma hemolytic pattern amongst which 11.5% were enterotoxigenic. Based on data provided on coagulation of human and canine plasmas and hemolytic patterns, it is concluded that a large proportion of canine isolates from this environment are not of canine biotypes, but are most probably human biotypes.
...
PMID:Isolation of enterotoxigenic strains of staphylococci from dogs. 664 5

Staphylococcal enterotoxins (SE) stimulate T cells expressing the appropriate variable region beta chain of (V beta) T-cell receptors and have been implicated in the pathogenesis of several autoimmune diseases. Depending on costimulatory signals, SE induce either proliferation or anergy in T cells. In addition, SE can induce an interleukin-2 (IL-2) nonresponsive state and apoptosis. Here, we show that SE induce dynamic changes in the expression of and signal transduction through the IL-2 receptor (IL-2R) beta and gamma chains (IL-2R beta and IL-2R gamma) in human antigen-specific CD4+ T-cell lines. Thus, after 4 hr of exposure to SEA and SEB, the expression of IL-2R beta was down-regulated, IL-2R gamma was slightly up-regulated, while IL-2R alpha remained largely unaffected. The changes in the composition of IL-2Rs were accompanied by inhibition of IL-2-induced tyrosine phosphorylation of the Janus protein-tyrosine kinase 3 (Jak3) and signal transducers and activators of transcription called Stat3 and Stat5. In parallel experiments, IL-2-driven proliferation was inhibited significantly. After 16 hr of exposure to SE, the expression of IL-2R beta remained low, while that of IL2R alpha and IL2R gamma was further up-regulated, and ligand-induced tyrosine phosphorylation of Jak3 and Stat proteins was partly normalized. Yet, IL-2-driven proliferation remained profoundly inhibited, suggesting that signaling events other than Jak3/Stat activation had also been changed following SE stimulation. In conclusion, our data suggest that SE can modulate IL-2R expression and signal transduction involving the Jak/Stat pathway in CD4+ T-cell lines.
...
PMID:Staphylococcal enterotoxins modulate interleukin 2 receptor expression and ligand-induced tyrosine phosphorylation of the Janus protein-tyrosine kinase 3 (Jak3) and signal transducers and activators of transcription (Stat proteins). 747 24


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---