Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0276640 (TEM)
 20,729 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In a preceding paper the genetics of resistance of 2 representative strains exhibiting resistance to beta-lactam antibiotics (ampicillin, catbenicillin, cephalothin) to aminoglycosides (kanamycin, neomycin, paromomycin, gentamycin, sisomycin, tobramycin, streptomycin, spectinomycin) and further antimicrobials (tetracycline, chloramphenicol, suphonamides) were described. This paper reports about the mechanism of resistance to beta-lactam antibiotics and aminoglycosides in these strains. Enzymatic extracts from K. pneumoniae 1 and Serratia marcescens 2 were produced by the osmotic shock procedure. Incubation of these extracts with aminoglycoside antibiotics, to which the strains are resistant, and ATP resulted in the total inactivation of the antimicrobials, as measured with a Bacillus subtilis assay. Analysis of this inactivation with the radioactive methods of Davies and his colleagues revealed that the kanamycins, neomycins, paromomycin and gentamycin A were phosphorylated. Because butirosin was not a substrate for the phosphorylating enzyme, it was concluded that the strain produced the neomycin/kanamycin phosphototransferase I. Furthermore, it was found that streptomycin and spectinomycin were adenylylated by the enzymatic extracts as well as gentamycin C1a, C1, C2, A, tobramycin, sisomycin and the kanamycins. This substrate profile indicated the presence of two adenylylating enzymes: streptomycin/spectinomycin-adenylyl-transferase and gentamycin-adenylyltransferase. After transfer of multiple drug resistance by conjugation from both strains into C. coli K-12, sonified extracts were prepared and examined for enzymatic activity splitting beta-lactam antibiotics. The relative rates of inactivation of benzylpenicillin, ampicillin and cephaloridine as well as the inhibitory effect of cloxacillin, but not of p-chloro-mercuri-benzoate on the inactivation of cephaloridine indicated that both strains produced a class III/type a (TEM type) beta-lactamase. It is discussed that the increasing frequency of gram-negative organisms form the university hospital with identical resistant phenotypes as the strains examined is the result of the spread of an R-factor among the hospital bacterial flora.
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PMID:[Resistance to beta-lactam antibiotics and aminoglycosides in gram negative bacteria. 2. Mechanism of resistance (author's transl)]. 77 54

Cell surface markers, enzymatic patterns, proliferation characteristics and metastatic behaviour of the DSA/2 derived SL2 lymphoma were determined. SL2 cells are sensitive to a heterologous antiserum to murine T-cells and to allo-antisera for Thy 1.2 and TL 1.2.3. They show acid-phosphatase, betaglucuronidase, acid-alpha-naphthytesterase and non-specific esterase staining. The reactions for ATP-ase, and 5'nucleotidase were negative. The SL2 tumour cells can be transplanted in vivo, growing rapidly both as an ascites or a solid tumour, and can be grown in vitro as a suspension culture (doubling time about 18 hours). One hundred cells kill an animal after i.p. transplantation, while 1,000 cells kill an animal after s.c. transplantation. Histopathological examination combined with TEM shows that SL2 metastasizes rapidly, especially after i.p. injection. The metastasizing cells reach the blood vessels in the lung septa and extravascular positions in the liver.
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PMID:Staging, growth properties and metastatic behaviour of a transplantable murine T-cell lymphoma. 612 81

Precursor forms of periplasmic and outer membrane proteins were accumulated in phenethyl-alcohol-treated cells in membrane fractions. After removal of phenethyl alcohol, maturation occurred in the absence but not in the presence of carbonylcyanide m-chlorophenylhydrazone (30 microM). The site and kinetics of processing were investigated for OmpA, LamB and OmpF proteins and for maltose binding protein and TEM beta-lactamase. With regard to sites of processing, no fundamental difference between outer membrane and periplasmic proteins was observed. For maltose binding protein and TEM beta-lactamase, maturation, like that of outer membrane protein precursors, occurred in membrane fractions. Processing of pro-OmpA protein was about as fast as that of pro-LamB protein whereas pro-OmpF protein appeared to mature more slowly. While carbonylcyanide m-chlorophenylhydrazone (30 microM) prevented processing of all precursor forms, arsenate, which alters formation of ATP even when it was used at 1 mM, did not totally prevent maturation occurring. These results are discussed with regard to the biosynthesis and assembly of exported proteins.
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PMID:Maturation of exported proteins in Escherichia coli. Requirement for energy, site and kinetics of processing. 628 6

The energy requirement for the maturation and export of the plasmid-encoded TEM beta-lactamase in Escherichia coli K12 was shown to be fulfilled by the total protonmotive force. This was demonstrated by assessing the inhibition of proteolytic processing of the precursor form of beta-lactamase caused by perturbation of the energized state of the membrane in cells treated with valinomycin. The magnitude of the membrane potential was manipulated by varying the concentration of KCl in the medium and the pH gradient was manipulated by varying the external pH. Both components were simultaneously affected by addition of the protonophore carbonylcyanide-p- trifluoromethoxy phenylhydrazone (FCCP). Inhibition of processing was demonstrated in a mutant strain having a defective ATP synthase where protonmotive force could be dissipated without altering the intracellular level of ATP, indicating that the observed inhibition was not the result of decreased ATP concentration. Half-maximal accumulation of precursor of beta-lactamase was observed in all cases when the level of protonmotive force was decreased to approximately 150 mV. Under those conditions the membrane potential varied from 65 to 140 mV (internally negative) and the pH gradient from 95 to 25 mV (internally alkaline). Thus, the energy requirement is satisfied by the total protonmotive force, with no specificity for either the membrane potential or the pH gradient.
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PMID:The requirement for energy during export of beta-lactamase in Escherichia coli is fulfilled by the total protonmotive force. 632 94

The lack of mucociliary transport causes chronic inflammations in the upper and lower respiratory tract and in the middle ear mucosa. The mucosa of 4 female patients with Kartagener's syndrome was studied by means of TEM (transmission electron microscopy) and SEM (scanning electron microscopy) and compared with the fine structure of normal cilia which were also found in these areas. All specimens studied showed, to a different extent, alterations in the fine structure of the axonemata, especially the absence or malformed ATP-ase dynein arms, the lack of spokes and/or the misarrangement of microtubuli within the cilia. The importance of this congenital anomaly - "immotile cilia" - is discussed with the trias of Kartagener's syndrome.
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PMID:[Ultrastructure of cilia in Kartagener syndrome]. 660 38

Twenty clinical isolates of ampicillin- and carbenicillin-resistant or susceptible (two strains) Gram-negative rods, producing at least one beta-lactamase, were examined for susceptibility to a combination of ampicillin or carbenicillin with clavulanic acid (enzymatic inhibitor). Synergy was evaluated by the reduction of the beta-lactam agar dilution MIC and by the measurement of intracellular AYP using firefly bioluminescence. The potentiation effect of clavulanic acid was variable, depending on resistance levels, species and types of beta-lactamase (TEM, SHV-1, CARB, OXA, MAL and Cpase). The synergy was significant, with 10 mg/l of inhibitor for all the strains producing TEM-1, TEM-2 and Carb-2 except for one strain of Serratia marcescens (TEM-2). The synergy was weak for Levinea strains (Citrobacter diversus biotype b), biosynthesizing specific penicillinases as MAL-1. No potentiation effect was observed for strains producing a cephalosporinase, such as Escherichia coli and Pseudomonas aeruginosa. This effect appeared to be variable for strains producing the oxacillin-hydrolysing enzyme (OXA-1), such as E. coli and P. aeruginosa. A positive correlation was clearly demonstrated between the MIC values and the intracellular ATP concentration in bacteria within 2 h. The opportunity of using the firefly assay for the rapid determination of synergy between beta-lactam antibiotics and clavulanic acid is discussed.
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PMID:[Rapid determination of the synergy of clavulanic acid and beta lactams by measuring the intracellular ATP by bioluminescence]. 681 96

Chaperonins are multisubunit protein complexes that can be isolated from cells as high-molecular-weight structures that appear as double rings in the electron microscope. We recently discovered that chaperonin double rings isolated from the hyperthermophilic archaeon Sulfolobus shibatae, when incubated at physiological temperatures in the presence of ATP and Mg2+, stacked into filaments; we hypothesized that these filaments are related to filaments seen inside S. shibatae cells and that chaperonins exist as filaments in vivo (J. D. Trent et al., 1997, Proc. Natl. Acad. Sci. USA 94, 5383-5388). This paper elucidates the conditions under which we have observed S. shibatae chaperonins to form filaments and evaluates native polyacrylamide gel electrophoresis (PAGE), TEM, spectrophotometry, and centrifugation as methods for studying these filaments. We observed that in the presence of Mg2+ combined with ATP, ADP, ATPgammaS, or GTP, native PAGE indicated that chaperonin subunits assembled into double rings and that the conformation of these double rings was effected by nucleotide binding, but we saw no indication of chaperonin filament formation. Under these same conditions, however, TEM, spectroscopy, and centrifugation methods indicated that chaperonin subunits and double rings had assembled into filaments. We determined that this discrepancy in the representation of the chaperonin structure was due to the native PAGE method itself. When we exposed chaperonin filaments to the electrophoretic field used in native PAGE, the filaments dissociated into double rings. This suggests that TEM, spectrophotometry, and centrifugation are the preferred methods for studying the higher-order structures of chaperonins, which are likely to be of biological significance.
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PMID:Chaperonin filaments: their formation and an evaluation of methods for studying them. 968 91

TolAI--II--beta-lactamase, a fusion protein consisting of the inner membrane and transperiplasmic domains of TolA followed by TEM--beta-lactamase associated with the inner membrane but remained confined to the cytoplasm when expressed at high level in Escherichia coli. Although the fusion protein was resistant to proteolysis in vivo, it was hydrolyzed during preparative SDS-polyacrylamide electrophoresis and when insoluble cellular fractions unfolded with 5 M urea were subjected to microdialysis. Inhibitor profiling studies revealed that both a metallo- and serine protease were involved in TolAI--II--beta-lactamase degradation under denaturing conditions. The in vitro degradation rates of the fusion protein were not affected when insoluble fractions were harvested from a strain lacking protease IV, but were significantly reduced when microdialysis experiments were conducted with material isolated from an isogenic ftsH1 mutant. Adenine nucleotides were not required for degradation, and ATP supplementation did not accelerate the apparent rate of TolAI--II--beta-lactamase hydrolysis under denaturing conditions. Our results indicate that the metalloprotease active site of FtsH remains functional in the presence of 3--5 M urea and suggest that the ATPase and proteolytic activities of FtsH can be uncoupled if the substrate is sufficiently unstructured. Thus, a key role of the FtsH AAA module appears to be the net unfolding of bound substrates so that they can be efficiently engaged by the protease active site.
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PMID:Escherichia coli FtsH (HflB) degrades a membrane-associated TolAI-II-beta-lactamase fusion protein under highly denaturing conditions. 1123 95

One hundred and sixty-eight children aged 13 months to 12.6 years with acquired platelet dysfunction with eosinophilia (APDE) were studied. The male to female ratio was 1.15:1. All of the children were in good health and no history of any drug ingestion was detected. All of the children had widespread spontaneous bruising on the extremities, body and face off and on. Severe bleeding symptoms were detected in 8% of these patients. The number of platelets in these children was within the normal range but the platelet morphology was abnormal in all of them. Eosinophilia was detected in 86% of these children. Prolonged bleeding time was detected in 53% of these patients. Abnormal platelet adhesiveness was found in 33% of cases. Abnormal platelet aggregation induced by collagen was the most sensitive test in these patients. Abnormal ADP release from the platelets was detected in these patients by the absence of a second wave of aggregation during stimulation of PRP by ADP or epinephrine. Abnormal or no ATP secretion from the platelets during stimulation by ADP, epinephrine or collagen was detected in these patients. Ristocetin-induced platelet aggregation was normal in these children. Decreased or absence of platelet dense granules by TEM study was detected in some patients. These changes in platelet functions and morphology may be due to acquired storage pool deficiency of the platelet. Parasitic infection was detected in 56% of these children. About 83% of these children with APDE had serum total IgE higher than 100 IU/ml. There was no correlation between the number of eosinophils and serum total IgE and the severity of bleeding symptoms. The majority of children with APDE did not receive any treatment except those who had severe bleeding symptoms which required platelet concentrate to stop bleeding. In more than 90% of the patients, the bruising or ecchymosis disappeared within 6 months and the abnormal platelet functions returned to normal within 4 months. Recurrence of these bleeding syndromes was detected in 7% of the children.
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PMID:Acquired platelet dysfunction with eosinophilia in children in the south of Thailand. 1128 30

Hyperactivated motility, a swimming pattern of mammalian sperm in the oviduct, is essential for fertilization in vivo. It is characterized by high-amplitude flagellar waves and, usually, highly asymmetrical flagellar beating. It had been suggested, but not tested, that Ca2+ and cAMP switch on hyperactivation by directly affecting the flagellar axoneme. In this study, the direct affects of these agents on the axoneme were tested by using detergent-demembranated bull sperm. As confirmed by TEM, treatment of sperm with 0.2% Triton X-100 disrupted the plasma, acrosomal, and inner mitochondrial membranes, leaving axonemes intact. In the presence of 2 mM ATP, the percentage of reactivated sperm that were hyperactivated increased to 80% when free Ca2+ was increased from 50 to 400 nM. The effect of the Ca2+ in this range was to increase beat asymmetry by increasing the curvature of the principal bend. No additional increases were observed above 400 nM free Ca2+, but motility was suppressed at 1 mM. The ability of Ca2+ to produce hyperactivation depended on ATP availability, such that more ATP was required to produce the high amplitude flagellar bends characteristic of hyperactivated motility than to produce activated motility. Cyclic AMP was not required for reactivation, nor for hyperactivation. Production of hyperactivated motility also required an alkaline environment (pH 7.9-8.5). These results suggest that, provided sufficient ATP is present and pH is sufficiently alkaline, Ca2+ switches on hyperactivation by enabling curvature of the principal bends to increase.
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PMID:Hyperactivated motility of bull sperm is triggered at the axoneme by Ca2+ and not cAMP. 1229 7


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