| enzymic procedures for determining the average state of adenylylation of escherichia coli glutamine synthetase. | | 1979 | 40453 |
| [studies on the antimicrobial effect of natural and synthetic humic acids (author's transl)]. | preparations of humic acids extracted from different soils by various methods and model humus substances obtained synthetically by oxidation of hydroquinone and pyrocatechin are tested for growth inhibition of representative strains of human pathogenic microorganisms using a micro serial dilution technique. within the concentration range of less than or equal to 2500 micrograms/ml 57 of 81 natural and also the two synthetic humic acids show antimicrobial activity with differing spectra. these su ... | 1978 | 40569 |
| [guanylate cyclase in e. coli. iii. purification and possible physiological role of gtpase]. | a phosphohydrolase with a preferential activity for gtp has been isolated and partially purified from e. coli extracts. the enzyme purification has been achieved through precipitation by ammonium sulfate and chromatography on deae-cellulose, deae-sephadex, ultragel and a second deae-cellulose column. the phosphohydrolase activity is poly (c) dependent. the chromatographic analysis on pei-cellulose has shown that the main product of gtp hydrolysis is gdp. the possibility that the enzyme partially ... | 1978 | 40673 |
| the effect of methylprednisolone on hepatic oxygen supply and plasma lactate and glucose in endotoxemia. | this study was designed to determine the effect of methylprednisolone on the profile of hepatic oxygen supply and selected blood parameters in fasted, male rats administered an ld85 dosage of e coli endotoxin intraperitoneally. mortality rates within 24 hours were 85% in rats receiving endotoxin only, 9% in rats receiving a 30 mg/kg dosage of methylprednisolone intraarterially one hour subsequent to endotoxin insult, and 0% in methylprednisolone controls. beginning with the fourth hour, untreate ... | 1979 | 40707 |
| ultraviolet irradiation disrupts somatic pili structure and function. | three piliated bacterial species were exposed to ultraviolet light (7 x 10(3) microw/cm2), and the effect of increasing duration of irradiation on the integrity of the somatic pili was quantitated by negative-stain electron microscopy. heavily piliated proteus mirabilis became devoid of pili after 20 min of irradiation, but escherichia coli and neisseria gonorrhoeae required 40 min for complete depiliation. partially purified proteus pili underwent progressive loss of structural integrity with i ... | 1979 | 40875 |
| attachment pili from enterotoxigenic escherichia coli pathogenic for humans. | pili from enterotoxigenic escherichia coli pathogenic for humans have been isolated by adsorption to the surface of erythrocytes followed by thermal elution. the pili are composed of two protein subunits with molecular weights of 13,100 and 12,500 as determined by sodium dodecyl sulfate-gel electrophoresis. these pili also bind to human buccal cells under temperature conditions (37 degrees c) which prevent the binding of these pili to the erythrocytes. analogous temperature effects on binding ha ... | 1979 | 40882 |
| purification and properties of a nicotinamide adenine dinucleotide-linked dehydrogenase that serves an escherichia coli mutant for glycerol catabolism. | glycerol:nad+2-oxidoreductase (ec 1.1.1.6) was purified to homogeneity from a mutant of escherichia coli k12 that uses this enzyme, instead of atp:glycerol 3-phosphotransferase (ec 2.7.1.30), as the first enzyme for the dissimilation of glycerol. polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate shows a subunit of 39,000 daltons. during electrophoresis under nondenaturing conditions, the protein migrates as two bands. these two forms, both of which are enzymatically ac ... | 1979 | 40950 |
| distribution of coenzyme f420 and properties of its hydrolytic fragments. | the ability of hydrolytic products of coenzyme f420 to substitute for f420 in the hydrogenase and nicotinamide adenine dinucleotide phosphate-liniked hydrogenase systems of methanobacterium strain m.o.h. was kinetically determined. the nicotinamide adenine dinucleotide phosphate-linked hydrogenase system was employed to quantitate the levels of f420 in a number of methanogenic bacteria as well as in some nonmethanogens. methanobacterium ruminantium and methanosarcina barkeri contained low levels ... | 1979 | 40952 |
| rhamnose-induced propanediol oxidoreductase in escherichia coli: purification, properties, and comparison with the fucose-induced enzyme. | escherichia coli are capable of growing anaerobically on l-rhamnose as a sole source of carbon and energy and without any exogenous hydrogen acceptor. when grown under such condition, synthesis of a nicotinamide adenine dinucleotide-linked l-lactaldehydepropanediol oxidoreductase is induced. the functioning of this enzyme results in the regeneration of nicotinamide adenine dinucleotide. the enzyme was purified to electrophoretic homogeneity. it has a molecular weight of 76,000, with two subunits ... | 1979 | 40956 |
| sucrose transport by the escherichia coli lactose carrier. | several lines of evidence suggest that sucrose is transported by the lactose carrier of escherichia coli. entry of sucrose was monitored by an osmotic method which involves exposure of cells to a hyperosmotic solution of disaccharide (250 mm). such cells shrink (optical density rises), and if the solute enters the cell, there is a return toward initial values (optical density falls). by this technique sucrose was found to enter cells at a rate approximately one third that of lactose. in addition ... | 1979 | 40957 |
| defective f pili and other characteristics of flac and hfr escherichia coli mutants resistant to bacteriophage r17. | mutants resistant to the donor-specific bacteriophage r17 were isolated from hfr and flac-containing strains of escherichia coli k-12. thirty-five mutants were examined for the presence of f pili by electron microscopy. the pilus morphology was studied, as were the abilities of the cells to retract their pili and to synthesize new pili. measurements were made of the efficiency of the conjugal deoxyribonucleic acid transfer and of m13 and r17 phage infection. all mutants had noticeable defects in ... | 1979 | 40959 |
| lysis of escherichia coli mutants by lactose. | growth of escherichia coli strain mm6-13 (ptsi suc laci sup), which as a suppressor of the succinate-negative phenotype, was inhibited by lactose. cells growing in yeast extract-tryptone-sodium chloride medium (lb broth) were lysed upon the addition of lactose. in casamino acids-salts medium, lactose inhibited growth, but due to the high k+ content no lysis occurred. lysis required high levels of beta-galctosidase and lactose transport activity. mm6, the parental strain of mm6-13, has lower leve ... | 1979 | 40961 |
| amino acid sequence of the biotinyl subunit from transcarboxylase. | the complete amino acid sequence of the biotinyl subunit from the enzyme transcarboxylase of propionibacterium shermanii has been determined from the structures of overlapping tryptic and cyanogen bromide peptides together with sequenator analysis on the whole subunit. the subunit contains 123 amino acid residues. eleven of nineteen residues in the region of biotin attachment, when compared to pyruvate carboxylase from avian liver (rylatt, d. b., keech, d. b., and wallace, j. c. (1977) arch. bio ... | 1979 | 40985 |
| aminoacyl-trna synthetase-catalyzed cleavage of the glycosidic bond of 5-halogenated uridines. | because of previous data suggesting that aminoacyl-trna synthetases make a transient michael adduct with a specific uridine residue in the trna structure, (schoemaker, h.j.p., and schimmel, p.r. (1977) biochemistry 16, 5454-5460) attempts were made to find simple model systems in which this reaction might be studied in more detail. in the course of these investigations, it was found that escherichia coli ile-trna synthetase catalyzes cleavage of the glycosidic bond of 5-bromouridine. at ph 7.5, ... | 1979 | 40993 |
| haemodynamic effects of the carboxylic ionophore monensin when administered before and during shock induced by e. coli endotoxin. | the haemodynamic effects of the carboxylic ionophore monensin have been examined in cats anaesthetized with sodium pentobarbitone. marked increases in left ventricular dp/dtmax (and dp/dt at fixed isovolumic pressures) and slight increases in cardiac output and stroke volume occurred, indicating increased myocardial contractility. heart rate was unchanged but systemic arterial pressure was substantially increased. satisfactory increases in contractility and arterial pressure were obtained when m ... | 1979 | 41057 |
| stability of the unique anticodon loop conformation of e.coli trnafmet. | initiator trnas have an anticodon loop conformation distinct from that of elongation trnas as detected by susceptibility to s1 nuclease. we now find the anticodon loop conformation of e. coli trnafmet to be stable under different salt conditions as detected by using s1 nuclease as a structural probe. in contrast, a conformational change is observed in the t- and d- loop of this trna in the absence of added mg2+. this change can be suppressed by spermine. even under those conditions effecting a c ... | 1979 | 41223 |
| a new glna-linked regulatory gene for glutamine synthetase in escherichia coli. | mutations in the glna region of the escherichia coli chromosome due to mu prophage insertion result in two phenotypic classes. one class is gln- and does not synthesize glutamine synthetase[l-glutamate:ammonia ligase (adp-forming), ec 6.3.1.2] under any growth condition. the other class produces a low level of glutamine synthetase under all growth conditions and is uncoupled from the regulatory effects of mutations in the glnf and glnd genes. complementation analysis demonstrates that these two ... | 1979 | 41243 |
| resistance of gram-negative bacteria to antibiotics in large calf agglomerations. | the antibiotic resistance of e. coli, citrobacter, enterobacter-klebsiella and pseudomonas aeruginosa strains isolated from calves was tested. a high proportion of multiresistance was found even in e. coli strains isolated from newborn calves. gram-negative bacteria isolated from animals in three large calfhouses were almost 100% resistant to ampicillin, tetracyclines and sulphonamides. multiresistance was general and varied from 5 to 12 antibiotics among different strains. initial high sensitiv ... | 1979 | 41425 |
| hydrogen-dependent proton translocation by membrane vesicles from escherichia coli [proceedings]. | | 1979 | 41779 |
| [effect of plasmid f'col+trp+ on the transfer of plasmid rp4]. | interaction of conjugative plasmids f'colv colb trp and pr4 in escherichia coli host was studied during the transfer of the plasmids from cell to cell. the plasmid f'colv colb trp is found to stimulate the transfer of rp4 from the diplasmid strain. this seems to be due to stabilization of the conjugating pairs which require normal pili coded by the plasmid f'colv colb trp. | 1979 | 41796 |
| [a clinical observation of cefuroxime in pediatric field (author's transl)]. | cefuroxime, a new synthetic cephalosporin, was administered to 10 pediatric patients (6 with respiratory tract infection, 2 with urinary tract infection, 1 with sepsis of e. coli and 1 with enterocolitis). the clinical result was good and excellent in all the 10 cases. no side effect was observed in any of them. | 1979 | 41955 |
| [photodynamic effect of quinacrine on bacteria]. | the acridine dye quinacrine (qa) was tested with regard to the photodynamic action on bacteria (proteus mirabilis, escherichia coli). the absorption maximum of the yellow dye qa ist in contrary to the photodynamically active dyes methylene blue (mb) and thiopyronine (tp) situated in the short wave region of the visible spectrum. using for illumination a common light source--they have in general a weak emission in the short wave region--relatively high concentrations of qa are necessary for photo ... | 1979 | 42229 |
| hyperproduction of tryptophan by escherichia coli: genetic manipulation of the pathways leading to tryptophan formation. | conversion of glucose and ammonium salts into tryptophan by mutants of escherichia coli was examined as part of a feasibility study on the manufacture of tryptophan. this involved construction, largely by transduction, or a variety of multiple-mutation strains with defined genotypes. by comparing the properties of these strains, we were able to define in biochemical terms several changes that significantly enhance process productivity, namely (i) release of the first enzyme of the common pathway ... | 1979 | 42347 |
| kinetics of the inactivation of escherichia coli glutamate apodecarboxylase by phenylglyoxal. | | 1979 | 42358 |
| quantitative analysis of proton-linked transport systems. the lactose permease of escherichia coli. | evidence is presented that lactose uptake into whole cells of escherichia coli occurs by symport with a single proton over the range of external ph 6.5--7.7. the proton/lactose stoicheiometry has been measured directly over this ph range by comparison of the initial rates of proton and lactose uptake into anaerobic resting cell suspensions of e. coli ml308. further, the relationship between the protonmotive force and lactose accumulation has been studied in e. coli ml308-225 over the range of ex ... | 1979 | 42390 |
| reactivity of the beta subunit of escherichia coli adenosine triphosphatase with 4-chloro-7-nitrobenzofurazan. | | 1979 | 42428 |
| modulation of purified phospholipase a2 activity from human platelets by calcium and indomethacin. | a membrane bound phospholipase a2 (phosphatide 2-acylhydrolase, ec 3.1.1.4) from human platelets has been purified 3500-fold, and partially characterized. phospholipase a2 activity was assayed using [1(-14)c] oleate-labeled escherichia coli or sonicated dispersions of synthetic phospholipids. the 2-acyl specificity of the phospholipase activity was confirmed using phosphatidylethanolamine labeled in the c-1 position as substrate. the purified enzyme was maximally active between ph 8.0 and 10.5, ... | 1979 | 42441 |
| studies on the subunits of escherichia coli coenzyme a transferase. reconstitution of an active enzyme. | the alpha and beta subunits of the acetyl-coa:acetoacetate-coa transferase were purified by isoelectric focusing of the enzyme in the presence of 6 m urea. the purified beta subunit, in which the active center of the enzyme is located, exhibits low catalytic activity (2% of the specific activity of the native enzyme) which is stimulated 5-6-fold in the presence of an equimolar concentration of alpha subunit. the presence of the substrate,acetoacetyl-coa, is required to recover the catalytic act ... | 1979 | 42442 |
| thymidylate synthetase from escherichia coli k12. purification, and dependence of kinetic properties on sugar conformation and size of the 2' substituent. | thymidylate synthetase from escherichia coli k12 has been purified 3600-fold by a series of chromatographic procedures. the final preparation had a specific activity of 1.47 units/mg protein and was approximately 80% pure. the enzyme is a dimer of relative molecular mass, mr, 64000 composed of two subunits of mr 32,000 each. its isoelectric point is 4.7 and it is stimulated by mg2+. michaelis constants for (+)5,10-methylene-5,6,7,8-tetrahydrofolate [(+)ch2h4folate] were 0.014 mm in the case of m ... | 1979 | 42538 |
| complete inactivation and labeling of methionyl-trna synthetase by periodate-treated initiator trna in the presence of sodium cyanohydridoborate. | methionyl-trna synthetase from escherichia coli can react with periodate-treated trna to form a schiff's base through the epsilon-amino group of a lysine within the enzymic active center and the 2',3'-aldehyde groups created at the 3'-terminal ribose of trna. at alkaline ph, the schiff's base equilibrium can be continuously and specifically displaced by reduction in situ with sodium cyanohydridoborate, which on the other hand leaves intact the reacting aldehyde groups of oxidized trna. the effec ... | 1979 | 42539 |
| fimbrial colonization factor cfa/1 protein from human enteropathogenic escherichia coli strains. purification, characterization and n-terminal sequence. | | 1979 | 42558 |
| antimicrobial activity of amniotic fluid obtained vaginally. | twenty-nine amniotic fluid samples were aspirated from pregnant women at term (38-40 weeks' gestation) by tapping the bulging membrane vaginally, and their effects on escherichia coli, staphylococcus aureus and candida albicans were studied. inhibition rates were 72.41% for e coli, 68.96% for s aureus and 79.31% for c albicans. two samples (6.90%) affected only a single organism, 18 (62.07%) affected two organisms and eight (27.59%) affected all three. only one sample (3.45%) had no inhibitory e ... | 1979 | 42590 |
| clinical investigation of serum deoxyribonuclease: i. analysis of serum deoxyribonuclease activity in comparison with normal and after endoscopic retrograde pancreatography. | serum deoxyribonuclease (dnase) micro-assay method was developed using 32p-labelled e. coli dna as substrate. the serum dnase showed maximum activity at ph 7.5. it required mg+ for activity, and was inhibited by edta or egta. the enzyme was also inhibited by actin (60-65%) or bovine pancreatic dnase i antibody (40-45%). the serum dnase activity was markedly increased following endoscopic retrograde pancreatography (erp) examination. these results imply that serum dnase activity is mostly at leas ... | 1979 | 42597 |
| studies on regulatory functions of malic enzymes. vii. structural and functional characteristics of sulfhydryl groups in nadp-linked malic enzyme from escherichia coli w. | nadp-linked malic enzyme from escherichia coli w contains 7 cysteinyl residues per enzyme subunit. the reactivity of sulfhydryl (sh) groups of the enzyme was examined using several sh reagents, including 5,5'-dithiobis(2-nitrobenzoic acid) (dtnb) and n-ethylmaleimide (nem). 1. two sh groups in the native enzyme subunit reacted with dtnb (or nem) with different reaction rates, accompanied by a complete loss of the enzyme activity. the second-order modification rate constant of the "fast sh group" ... | 1979 | 42642 |
| phosphoenolpyruvate carboxylase of escherichia coli. affinity labeling with bromopyruvate. | phosphoenolpyruvate carboxylase [ec 4.1.1.31] from escherichia coli w was alkylated by incubation with bromopyruvate, substrate analog, leading to irreversible inactivation. the reaction followed pseudo-first-order kinetics. mg2+, an essential cofactor for catalysis, enhanced the inactivation, and the enhancing effect increased as the ph increased. the inactivation rate showed a tendency to saturate with increasing concentrations of bromopyruvate, indicating that an enzyme-bromopyruvate complex ... | 1979 | 42643 |
| the effect of chloroquine on macromolecule synthesis and oxygen uptake in escherichia coli [proceedings]. | | 1979 | 42705 |
| the action of propyl gallate (n-propyl 3,4,5-trihydroxybenzoate) on escherichia coli nctc 5933 [proceedings]. | | 1979 | 42708 |
| absence of plasmid-mediated dna polymerase activity from uv-induced strains of escherichia coli [proceedings]. | | 1979 | 42709 |
| the enhancement of neomycin activity on escherichia coli by entrapment in liposomes [proceedings]. | | 1979 | 42764 |
| amplification and characterization of the proline transport carrier of escherichia coli k-12 by using prot+ hybrid plasmids. | a previous report [motojima, k., yamato, i. & anraku, y. (1978) j. bacteriol. 136, 5-9) described the characteristics of mutants (prot-) of escherichia coli k-12 that are defective in proline transport carrier activity. two hybrid plasmids from the clarke and carbon colony bank were found to complement the mutation by conjugation and transformation. analysis with restriction endonucleases showed that both plasmid dnas carried the same fragment of the e. coli chromosome. a polypeptide with a mole ... | 1979 | 42912 |
| linked transport of phosphate, potassium ions and protons in escherichia coli. | pi entry into escherichia coli cells through either of the two pi-transport systems (pit or pst) prompts the influx of k+ and h+ in a ratio that depends on the external ph. the entry of pi is absolutely dependent on the presence of k+, and the entry of k+ is equally dependent on the presence of pi. experiments with a number of mutants carrying any one functional pi-transport system and one or more of the individual k+-transport systems indicate a permissive type of linkage of the two transports, ... | 1979 | 43137 |
| studies on the metabolism of unsaturated fatty acids. ii. separation and general properties of reduced nicotinamide adenine dinucleotide phosphate dependent cis-2-enoyl-coenzyme a reductase from escherichia coli k-12. | | 1979 | 43196 |
| mannose-sensitive stimulation of human leukocyte chemiluminescence by escherichia coli. | escherichia coli organisms with mannose-sensitive adherence factors (adhesins) are known to associate with human peripheral leukocytes (wbcs) in vitro in the absence of serum. to determine whether the wbc respiratory burst is activated during the interaction with e. coli, wbc chemiluminescence was measured. e. coli with mannose-sensitive adhesins stimulated a sharp burst of chemiluminescence which peaked 15 to 30 min after the bacteria and wbcs were mixed. stimulation of chemiluminescence could ... | 1979 | 43285 |
| opsonic activity of normal human cerebrospinal fluid for selected bacterial species. | the opsonic activity of normal human cerebrospinal fluid (csf) has not been well defined. in this study, the opsonic activity of normal csf for laboratory and blood culture isolates of staphylococcus aureus, streptococcus pneumoniae, escherichia coli, hemophilus influenzae type b, and neisseria meningitidis was measured by a quantitative assay employing radiolabeled bacteria and polymorphonuclear leukocytes. all isolates of s. aureus, except the wood 46 strain, were opsonized in undiluted csf (> ... | 1979 | 43289 |
| effects of heat-stable enterotoxin of yersinia enterocolitica on ion transport and cyclic guanosine 3',5'-monophosphate metabolism in rabbit ileum. | strains of yersinia enterocolitica produce a heat-stable enterotoxin which is positive in the suckling mouse bioassay. partial purification by a procedure previously worked out for heat-stable escherichia coli enterotoxin yielded a substance which increases particulate guanylate cyclase activity and short-circuit current and inhibits active cl-absorption in rabbit ileal mucosa. these effects of y. enterocolitica enterotoxin are similar to those of heat-stable e. coli enterotoxin, suggesting a co ... | 1979 | 43292 |
| properties of a gonococcal inhibitor produced by escherichia coli. | strains of escherichia coli can inhibit the in vitro growth of neisseria gonorrhoeae. one e. coli strain released a potent agar-diffusible gonococcal growth inhibitor which was extracted and assayed in an agar well assay system. the culture conditions necessary to produce the inhibitor were determined. the inhibitor was bacteriostatic, in most cases, for n. gonorrhoeae. based on ultrafiltration and column chromatography, the inhibitor appeared to have a molecular weight in the range of 1200 to 2 ... | 1979 | 43357 |
| relationship between the antibacterial activity towards escherichia coli nctc 5933 and the physico-chemical properties of some esters of 3,4,5-trihydroxybenzoic acid (gallic acid). | aqueous solubilities, oleyl alcohol: water and octanol: water partition coefficients, rm values, reduction in surface tension of water, relative antioxidant activities and pka values, were determined for gallic acid and a series of its alkyl esters. correlations were sought between these physico-chemical measurements and mic, mbc and killing-rate determinations against escherichia coli. variations in antibacterial activity generally correlated well with partition parameters, but these correlatio ... | 1979 | 43458 |
| [effect of the salt content and ph of the dispersion medium on escherichia coli phage t2 sorption by natural cherkassy montmorrillonite]. | | 1979 | 43459 |
| quantitative extraction and estimation of intracellular nicotinamide nucleotides of escherichia coli. | | 1979 | 43686 |
| [compared survival of "escherichia coli" and "salmonella typhi-murium" in cold water (author's transl)]. | the survival rates of escherichia coli and salmonella typhi-murium in water are studied at 4, 10 and 20 degrees c and ph 6 and 8, either separately or in mixed culture at four different ratios. s. typhi-murium's survival rate is enhanced at ph 6 and low water temperature. the value of traditional microbiological indicators in assessed in cold water conditions. | 1979 | 43688 |
| intestinal microflora and bile acids. in vitro cholic acid transformation by mixed fecal culture of rats. | in vitro cholic acid (ca) transformation by mixed fecal culture was investigated. concentrations of glucose, peptone, and yeast extract in the medium and the initial ph of the medium markedly affected the ca transformation. yeast extract enhanced the transformation, whereas high concentrations of glucose and peptone inhibited it. when the initial ph of the medium was below 6.5, ca was converted to 7-keto-deoxycholic acid (7kd), and formation of deoxycholic acid (dc) was not observed. in contrast ... | 1979 | 43948 |
| inosine 5'-monophosphate dehydrogenase of escherichia coli. purification by affinity chromatography, subunit structure and inhibition by guanosine 5'-monophosphate. | escherichia coli imp dehydrogenase (ec 1.2.1.14) was purified by affinity chromatography on immobilized nucleotides. the enzyme binds to agarose-bound 8-(6-aminohexyl)-amp, n6-(6-aminohexyl)-amp and 8-(8-amino-octyl)-imp but not to immobilized nad+ or cibacron blue f3g-a. amp proved to be an effective eluent. a large-scale purification scheme in which 8-(6-aminohexyl)-amp-agarose was used resulted in a homogeneous preparation of imp dehydrogenase. the enzyme was also purified by immunoprecipitat ... | 1979 | 44191 |
| the twenty aminoacyl-trna synthetases from escherichia coli. general separation procedure, and comparison of the influence of ph and divalent cations on their catalytic activities. | a general separation procedure of the twenty e. coli aminoacyl-trna synthetases including either a 105 000 g centrifugation or a poly-ethyleneglycol-dextran two-phases partition fractionation, and chromatographies on deae-cellulose, phosphocellulose and hydroxyapatite is described. the specific activities of the synthetases have been determined after each chromatographic step and compared to their respective activities in the 105 000 g supernatant. some aminoacyl-trna synthetases were obtained a ... | 1979 | 44203 |
| the action of tributyltin chloride on the uptake of proline and glutamine by intact cells of escherichia coli. | tributyltin chloride inhibits growth and uptake of glutamine and proline into intact cells of escherichia coli. it causes efflux of the accumulated amino acids. a ph gradient generated in intact cells and everted membrane vesicles is dissipated by this compound. these effects do not require lipoic acid but are dependent on the presence of chloride, bromide, or iodide ions. we conclude that tributyltin chloride can catalyse a transmembrane oh- -anion exchange exchange reaction and that this is it ... | 1979 | 44216 |
| the action of tributyltin chloride on energy-dependent transhydrogenation of nadp+ by nadh in membranes of escherichia coli. | respiration- and atp-dependent transhydrogenation of nadp+ by nadh in everted membrane vesicles from escherichia coli is inhibited by nigericin but is relatively insensitive to valinomycin. the sensitivity to nigericin is enhanced 30-fold in the presence of valinomycin. it is concluded that both the transmembrane ph difference and the membrane potential constitute the driving force for energy-dependent transhydrogenation. respiration- and atp-dependent transhydrogenation are inhibited by tributy ... | 1979 | 44217 |
| statistico epidemiological study of changes in the vaginal flora of contraceptive pill users in alexandria. | a stratified random sample of 1000 women with proportionate allocation according to district of residence was taken from normal females living in alexandria, egypt, and attending family planning centers in order to understand social-pathological changes in the vaginal flora of oral contraceptive (oc) users. cases were examined over 18 months, and all cases were given a combined oc. bacteriology and ph changes in vaginal flora were determined after 18 months. results of the bacteriological exa ... | 1979 | 44312 |
| more than one stable stationary state in the cell concentration of thiamine-limited escherichia coli 2000 chemostat cultures. | | 1979 | 44591 |
| ultrastructure and viability of e. coli treated fosfomycin. | in concentrations of 6 microgram/ml fosfomycin acted bactericidal against e. coli atcc 10536. the sensitivity of e. coli was evaluated by turbidity measurement (table 1) and by counting colony forming units (cfu) (table 2). thus the bactericidal action began at different times in respect to the concentration and the method of documentation: turbidity fell 30-120 min after the administration of 6 microgram/ml and 10-30 min after 60 microgram/ml; cfu were reduced 10-30 min after 6 microgram/ml and ... | 1979 | 44623 |
| [protective role of salmonella r mutants in salmonella infection in mice (author's transl)]. | nmri mice were immunized with acetone-killed bacteria of 6 salmonella r mutants, 5 homologous and 6 heterologous salmonella s forms and 3 e. coli r mutants. the animals were then challenged with graded amounts of live s. typhimurium. the results show that the protection obtained was dependent on the number of immunizing injections and on the time interval between them. thus in the case of salmonella r-mutants two immunizations increased the ld50 of challenge by an index of two (log 10) compaired ... | 1979 | 44625 |
| in vitro adherence of radioactively labeled escherichia coli in normal and cystitis-prone females. | numerous investigators report data obtained using an in vitro quantitative assay for measuring bacterial adherence to epithelial cells. we found this assay to contain significant sources of error in the large variation in number of bacteria bound per cell and in the dependence on the investigator's visual counting of bacteria bound per cell. in the modified assay described here, we eliminated the need for visual counting of bacteria by incorporating the use of radioactively labeled escherichia c ... | 1979 | 44702 |
| mannose-sensitive interaction of escherichia coli with human peripheral leukocytes in vitro. | the ability of escherichia coli which possess or lack mannose-sensitive adherence factors (adhesins) to associate with human peripheral leukocytes in vitro in the absence of serum was studied. e. coli 19+, which have mannose-sensitive adhesins, were derived from e. coli strain 19 by culturing in static trypticase soy broth at 37 degrees c. e. coli 19-, which lack mannose-sensitive adhesins, were derived from e. coli 19 by culturing in agitated trypticase soy broth at 30 degrees c. e. coli 19+ at ... | 1979 | 44703 |
| quantitation of the adherence of an enteropathogenic escherichia coli to isolated rabbit intestinal brush borders. | two assays were developed to quantitate the adherence of an escherichia coli strain (rdec-1) known to colonize the mucosal surface of the small intestine of rabbits to brush borders isolated from rabbit intestinal epithelial cells. in the first assay, the mean adherence per rabbit brush border was determined by counting the number of organisms adhering to each of 40 brush borders under phase microscopy. the mean adherence of rdec-1 (11.5 +/- 0.7 per rabbit brush border) was significantly greater ... | 1979 | 44705 |
| [comparison of four recently introduced cephalosporins with respect to probability of resistance in multiresistant strains of escherichia coli, proteus mirabilis and klebsiella spec. (author's transl)]. | strains with the same number of resistances were arranged in so-called resistance classes. nine classes of resistance (0 to greater to or equal to 8) were formed by means of ten standard chemotherapeutics; the four new cephalosporins were excluded. for every resistance class frequency of cephalosporinresistance was described as coefficient ranging from 0 to 1 (fig. 1). in cephalothin the coefficients were markedly rising only in 6 (7)-fold resistant strains of the species examined. similar but s ... | 1979 | 44785 |
| [the distribution of minimal inhibitory concentrations of recently introduced cephalosporins in multiresistant strains of escherichia coli, proteus mirabilis and klebsiella spec. as revealed by zone sizes of a standardized agar diffusion test (author's transl)]. | strains of a species were divided into two groups according to the number of resistances (less than or equal to 4, greater than or equal to 5) using 10 standard chemotherapeutics regularly examined, the new cephalosporins not being among them. these groups of less than or equal to 4- and greater than or equal to 5-fold resistant strains were compared for each cephalosporin tested (fig. 1). the most different distributions of zone diameters (of both groups) were seen in cephalothin, whereas in ce ... | 1979 | 44786 |
| neisseriaceae, a group of bacteria with dihydrofolate reductases, moderately susceptible to trimethoprim. | dihydrofolate reductases of five species of the family neisseriaceae were compared by means of inhibition profiles, using several structurally different inhibitors, including trimethoprim (tmp) and pyrimethamine. all enzymes were seen to be highly susceptible to the folate analog aminopterin, but exhibited moderate susceptibility to all other inhibitors tested. approximately 200-fold higher concentrations of tmp were needed to inhibit neisserial reductases as compared to the e. coli enzyme. besi ... | 1979 | 44939 |
| spectrum of escherichia coli agglutinins in dam's sera, colostrum and calf's sera in fresian cows and buffaloes in egypt. | sera collected from 18 pregnant buffaloes and fresian cows during the last two weeks before parturition and from the newborn calves during the first two weeks after birth. all the samples together with the colostral whey of the first three days were examined for the presence of e. coli agglutinins using the tube agglutination and passive hemagglutination tests. the latter test was more sensitive and demonstrated higher titres in all cases, and consequently more o groups. agglutinins to various e ... | 1979 | 44940 |
| importance of colicinogeny for the course of acute bacillary dysentery. | the development of acute bacillary dysentery was followed in 23 patients involved in two outbreaks and in three sporadic, mutually unrelated cases. repeated cultivations performed at 2-day intervals for 10 days yielded 386 identifiable strains of "opportune intestinal flora". escherichia coli colicinogenic activity is one of the significant factors of gastrointestinal tract protection. the period of shigella excretion is significantly reduced (p less than 0.02) if an appropriate colicinogenic e. ... | 1979 | 44941 |
| further characterization of "promptly" and "delayed" human serum-sensitive strains of serratia marcescens. | the kinetics of the bactericidal activity of 80 vol% of fresh human serum against representative 'delayed serum-sensitive' (dss) and 'promptly serum-sensitive' (pss) strains of serratia marcescens were further examined with regard to various chemical and absorption procedures known to affect various components of the alternative and classical pathways of human complement activation. inulin treatment of fresh human serum failed to diminish serum bactericidal activity against dss and pss assay str ... | 1979 | 44945 |
| [in vitro activity of cefaclor (author's transl)]. | a comparative study was conducted on the in vitro activity of cefaclor and other oral cephalosporins against a large number of freshly isolated clinical strains of gram-negative and gram-positive bacteria. the activity of cefaclor against gram-positive pathogens is very similar to that of cephalexin. the action of cefaclor against streptococcus pneumoniae is superior. cefaclor is the most active antibiotic against strains of haemophilus influenzae, and is also more active than cephalexin and cep ... | 1979 | 45087 |
| from penicillin-binding proteins to the lysis and death of bacteria: a 1979 view. | the mechanism by which interference with the biosynthesis of bacterial cell wall causes death and lysis of bacteria appears more complex than originally thought. in an earlier model of the mode of action of beta-lactams, it was assumed that, in the presence of the antibiotics, bacteria synthesize a mechanically weak (poorly cross-linked) cell wall that ruptured under the osmotic-mechanical pressure of the normally growing cytoplasmic mass. however, recent findings suggest a much more complex pic ... | 1979 | 45147 |
| on the role of the recipient cell during conjugation in escherichia coli. | to study the role of the e. coli recipient cell in conjugation recipient cell mutants deficient in conjugation (con-) were isolated. mutants specific for f-type e. coli donor cells (conf-) and mutants specific deficient in conjugation with i-type donor cells (coni-) were isolated. both conf- and coni- mutants were blocked in stable mating pair formation. biochemical analysis of the mutants suggests that the outer membrane protein coded by the ompa gene and lps are important for recipient activit ... | 1979 | 45216 |
| regulation of biosynthesis of aminoacyl-transfer rna synthetases and of transfer-rna in escherichia coli. | we have isolated temperature resistant revertants from temperature sensitive e. coli strains containing either a thermolabile glutaminyl-trna synthetase or leucyl-trna synthetase. among the revertants which still contained the thermolabile leucyl-trna synthetase we found two classes of regulatory mutants (leux and leu y) which have elevated levels of this enzyme. the leux mutation specifies an operator-promoter region adjacent to the structural gene (leus) for the enzyme. the leuy gene maps away ... | 1979 | 45219 |
| enzymatic methyl esterification of escherichia coli ribosomal proteins. | enzymatic methyl ester formation in escherichia coli ribosomal proteins was observed. alkali lability of the methylated proteins and derivatization of the methyl groups as methyl esters of 3,5-dinitrobenzoate indicate the presence of protein methyl esters. the esterification reaction occurs predominantly on the 30s ribosomal subunit, with protein s3 as the major esterified protein. when the purified 30s subunit was used as the methyl acceptor, protein s9 was also found to be esterified. the enzy ... | 1977 | 45488 |
| genetic determinants of microbial resistance to antibiotics. | emergence of antibiotic resistance is related to the ease of mutation, to the extent of exchange of genetic information in bacteria by conjugation, transformation, and transduction, and to the large-scale use of antimicrobial agents in the biosphere. in addition to the development of resistance through chromosomal mutation and exchange of chromosomal genes among organisms, there is a more profound enlargement of the gene pool by the dissemination and amplification of plasmids. two examples of th ... | 1979 | 45522 |
| serum cholesterol and bowel flora in the newborn. | bottle-fed infants have a total serum cholesterol of 147 mg/100 ml on the fifth day of life and their stools contain more escherichia coli than lactobacilli organisms. the ratio of these bacteria can be reversed by adding bicarbonate or lactobacilli to feeds. this change is associated with a decrease in total cholesterol to a mean 119 mg/100 ml over the next 3 days. lactobacilli organisms predominate in the stools when serum cholesterol is low and may play a role in the metabolism of cholesterol ... | 1975 | 45573 |
| bacteriophage spp1 polypeptides synthesized in infected minicells and in vitro. | minicells produced by b. subtilis cu403divivb1 and infected by spp1 synthesize at least 46 polypeptides which can be separated by polyacrylamide gel electrophoresis. these polypeptides represent the expression of 86% of the spp1 genome's coding capacity. infection of minicells by sus mutants and deletion mutants of spp1 has permitted a correlation of genetic location with gene product and has shown that spp1 normally synthesizes at least 8 non-essential polypeptides. restriction fragments of spp ... | 1979 | 45610 |
| proton conductor vs. cold in induction of ca(2+)-dependent competence in escherichia coli. | in order to elucidate the molecular mechanisms of ca(2+)-dependent competence in gram-negative bacteria an attempt was made to induce the competence at room temperature in presence of a proton conductor, carbonylcyanide-m-chlorophenylhydrazone (cccp). escherichia coli k12 cells treated with ca2+ at 25 degrees or 37 degrees c in presence of cccp became permeable for transforming plasmid and transfecting dnas and dna-binding antibiotic actinomycin c (amc) and rubomycin (rm) at room temperature. th ... | 1979 | 45613 |
| cation-sugar cotransport in the melibiose transport system of escherichia coli. | the entry of na+ or h+ into cells of escherichia coli via the melibiose transport system was stimulated by the addition of certain galactosides. the principal cell used in these studies (w3133) was a lactose transport negative strain of e. coli possessing an inducible melibiose transport system. such cells were grown in the presence of melibiose, washed, and incubated in the presence of 25 microm na+. the addition of thiomethylgalactoside (tmg) resulted in a fall in na+ concentration in the incu ... | 1978 | 45782 |
| quantitative comparisons of various biological responses of neutrophils to different active and inactive chemotactic factors. | the effects of chemotactic factors on rabbit neutrophils were evaluated measuring cell migration in modified boyden chambers and under agarose, in lysosomal enzyme release, leukocyte aggregation, and in vivo neutropenia. chemotactins employed included the complement-derived c3 and c5 fragments, the bacterial chemotactic factor from culture supernatant fluids of escherichia coli, and the synthetic chemotactic factors met-leu-phe and formyl-met-leu-phe. a consistent parallelism was found in all th ... | 1978 | 45788 |
| in vivo and in vitro binding of dihydrostreptomycin to escherichia coli ribosomes. | | 1975 | 45914 |
| urinary-tract infection: localisation and virulence of escherichia coli. | virulence of 15 strains of escherichia coli from the human upper urinary tract was compared with that of 16 strains from the lower urinary tract, using an ascending infection in the mouse. no significant difference was found. there was no significant difference in frequency of k antigen and ability to ferment dulcitol between 32 lower strains and 31 upper strains. however, 22 strains containing k antigen, regardless of anatomical site of localisation, were more significantly likely to cause infe ... | 1975 | 46051 |
| antibacterial activity of antisera against homologous and heterologous escherichia coli of porcine origin. | fourteen enteropathogenic and five nonenterotoxigenic escherichia coli strains isolated from pigs were used for producing antisera in rabbits and pigs. these antisera were used in an vitro test system for antibacterial activity against homologous and heterologous porcine e. coli strains. antibacterial titres were determined against the homologous strains and the percent reduction in cfu/ml caused by a 1/200 dilution of the sera against heterologous strains was determined. the results indicated t ... | 1975 | 46176 |
| energy coupling in the uptake of hexose phosphates by escherichia coli. | several methods were used to study the source of energy in the uptake of hexose phosphates by escherichia coli k12. the uptake was sensitive to inhibition by agents that affect electron transport, such as lack of oxygen, cyanide, and heptylhydroxyquinoline-n-oxide, and by agents that affect atp utilization, such as dicyclohexylcarbodiimide and arsenate. it was also sensitive to uncouplers in the presence of absence of oxygen. the strain of e. coli used extruded protons during respiration. uncer ... | 1975 | 46228 |
| spontaneous and methylcholanthrene-enhanced thyroiditis in buf rats. ii. induction of experimental autoimmune thyroiditis without completed freund's adjuvant. | the immunization of buffalo strain (buf) rats with rat thyroid extract and bordetella pertussis vaccine without complete freund's adjuvant resulted in experimental autoimmune thyroiditis (eat) in 90% of the rats by the 10th day after immunization. the treatment did not elicit thyroiditis in lewis strain (lew) rats. this susceptibility to the induction of eat without the use of complete freund's adjuvant was inherited by f1 hybrids of buf and lew. neither histamine sensitizing factor from b. pert ... | 1975 | 46238 |
| comparison of the ocular effects of circulating endotoxin and immune complexes: role of vasoactive amines. | both bacterial endotoxin and soluble immune complexes (bgg-anti bgg) injected i.v. in rabbits produce an alteration in ocular vascular permeability confined primarily to the vessels of the iridial portion of the ciliary processes. these effects have been measured by the ocular accumulation of 125i-albumin relative to cardiac plasma. ten micrograms per kilogram of escherichia coli bacterial endotoxin (055:b5) produce a consistent alteration in ocular vascular permeability over a 90-min period aft ... | 1975 | 46248 |
| an attempt to identify the intestinal receptor for the k88 adhesin by means of a haemagglutination inhibition test using glycoproteins and fractions from sow colostrum. | the k88 antigen of escherichia coli specifically adheres to the piglet intestinal cell; a solution of this antigen agglutinates guinea-pig red cells at 4 degrees c. the latter reaction was used as a model of the former, using inhibition of haemagglutination as an index of specific combination with the k88 adhesin. inhibition was found with mucous glycoproteins and chemical modification of their heterosaccharide residues by mild acid hydrolysis, periodate oxidation or the smith degradation proced ... | 1975 | 46271 |
| salmonella typhimurium resistant to silver nitrate, chloramphenicol, and ampicillin. | a strain of salmonella typhimurium appeared sequentially in three patients in a burn unit, and epidemiological study suggested the occurrence of person-to-person spread. this organism was responsible for both colonisation and invasive infection in these patients whose burn surfaces were receiving topical treatment with 0.5% silver nitrate (agno3) solution. the antibiotic and metal ionsusceptibility pattern of this strain of s. typhimurium was unique and disturbing: resistant to silver nitrate, m ... | 1975 | 46385 |
| letter: urinary-tract infection: localisation and virulence of escherichia coli. | | 1975 | 46405 |
| limulus test in escherichia coli enteritis. | | 1975 | 46566 |
| precursor relationship of phenylalanine transfer ribonucleic acid from escherichia coli treated with chloramphenicol or starved for iron, methionine, or cysteine. | when treated with chloramphenicol, escherichia coli 15t minus produces two new species (iv and v) of transfer ribonucleic acid specific for phenylalanine in addition to the major normal species (ii) and two minor normal species (i and iii), which are seen as distinct components upon fractionation by chromatography on columns of benzoylated diethylaminoethyl-cellulose. species iv is produced when cells are grown in iron-deficient medium and is, therefore, probably deficient in the 2-methylthio mo ... | 1975 | 46864 |
| regulation of acetohydroxy acid synthase in streptomycin-dependent escherichia coli. | growth of streptomycin-dependent mutants of escherichia coli k-12 was insensitive to valine when dihydrostreptomycin was present in a nonlimiting concentration in glucose-salts medium. acetohydroxy acid synthase was derepressed under these conditions, owing to relaxation of catabolite repression. valine sensitivity and catabolite repression were restored when streptomycin-dependent e. coli k-12 mutants were grown with limiting dihydrostreptomycin. end product repression of acetohydroxy acid synt ... | 1975 | 46865 |
| [experimental malakoplakia in the kidney]. | malakoplakia in kidney of rats was caused experimentally by injection of large quantities of not purified endotoxin-antigen complex of escherichia coli 0 75 (o. coli 127 97 cdc 0 group 75; american type culture collection, eight edition 1968, page 24). the extract in the beginning became surrounded by leukocytes, later by macrophages. the latter then were transformed into characteristic hansemann cells. from the 8th day on started the depletion of calcium phosphate in the cytosegresomes of macro ... | 1975 | 47145 |
| ampicillin-resistant haemophilus influenzae type b possessing a tem-type beta-lactamase but little permeability barrier to ampicillin. | ampicillin-resistant haemophilus influenzae type b have been reported only during the past year. five clinical isolates from the u.s. and germany all had the tem-type beta-lactamase which is known to be transferred widely among other gram-negative bacilli. unlike those bacilli, however, the h. influenzae cell had very little barrier to entry of penicillins. this greater permeability of the h. influenzae cell to penicillins appeared to reduce the protective effect of its beta-lactamase, in that a ... | 1975 | 47483 |
| induction of endogenous murine c-type virus in spleen cell cultures treated with mitogens and 5-bromo-2'-deoxyuridine. | in short-term cultures of balb/c spleen cells, treatment with a combination of 5-bromo-2'-deoxyuridine (brdu) and either lipopolysaccharide w. escherichia coli or concanavalin a resulted in release of c-type virus into the medium. only lipopolysaccharide induced virus release when given alone. this could be potentiated by a combined treatment with brdu. in contrast, phytohemagglutinin at mitogenic concentration had no effect with or without brdu, suggesting that inducibility may vary between var ... | 1975 | 47632 |
| degradation of lindane by escherichia coli. | lindane was degraded by escherichia coli isolated from rat feces. about 10% of the added lindane was metabolized by the bacterium in trypticase soy broth containing the pesticide. a single metabolite, 2,3,4,5,6-pentachloro-1-cyclohexene, was detected and identified by gas chromatography and mass spectrometry. | 1975 | 47737 |
| the threonine-sensitive homoserine dehydrogenase and aspartokinase activities of escherichia coli k12. distribution and accessibility to antibodies of some epitopes of the bifunctional enzyme. | in the presence of l-threonine, the allosteric effector, most of the antigenic determinants situated in the aspartokinase region of the wild-type enzyme become unavailable to the antibodies raised against a fragment of the enzyme containing this region and devoid of homoserine dehydrogenase activity. the cross-reactivities of the antibodies raised against this fragment (extracted from a nonsense mutant) and a fragment endowed with homoserine dehydrogenase activity but devoid of aspartokinase act ... | 1975 | 47808 |
| enhanced bactericidal activity of phagocytes from patients with chronic granulomatous disease in the presence of sulphisoxazole. | the decrease in the frequency and severity of bacterial infections in four of five children with chronic granulomatous disease (c.g.d.) on long-term sulphonamide therapy was out of proportion to demonstrable direct antibacterial effects of the drug. in an attempt to determine the mechanism for this apparent protective effect, the killing of sulphisoxazole-resistant escherichia coli and staphylococcus aureus by leucocytes from five patients with c.g.d. was studied in the presence or absence of 5- ... | 1975 | 48055 |
| induction of serum haemophilus influenzae type b capsular antibodies in adult volunteers fed cross-reacting escherichia coli 075:k100:h5. | serum haemophilus influenzae type b (hitb) anticapsular antibodies were induced in adult volunteers by feeding of either of two strains of a cross-reacting escherichia coli 075:k100:h5. in all the fed volunteers colonization for a finite period lasting up to eight weeks occurred, without adventitious reactions. nine of 14 normal volunteers and one of two volunteers previously immunized with the type 6 h.influenzae polysaccharide responded with a greater than twofold increase in serum type 6h. in ... | 1975 | 48191 |
| evolution of biosynthetic pathways: immunological approach. | through the use of specific immunoadsorbent columns, it is shown that escherichia coli aspartokinase i-homoserine dehydrogenase i, aspartokinase ii-homoserine dehydrogenase ii, aspartokinase iii, and homoserine kinase, enzymes involved in the same complex biosynthetic pathway, share antigenic determinants. this raises the question of a common origin for the four cibtenoirart kinases. (aspartate kinase or atp:l aspartate 4-phosphotransferase, ec 2.7.2.4; homoserine dehydrogenase or lhomoserine:na ... | 1975 | 48255 |
| infection caused by proteus mirabilis strains with transferrable gentamicin-resistance factors. | during a period of 10 weeks, four patients in one hospital became infected with gentamicin-resistant proteus mirabilis. in two of them septicaemia associated with indwelling catheters developed, one had urinary tract and wound infections, and in the fourth patient the organism was isolated from a superficial wound. the p. mirabilis strains showed multiple drug resistance. strains form the first three patients were apparently identical and were sensitive to tobramycin. their gentamicin resistance ... | 1975 | 48945 |