Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| 9-aminoacridine-a frameshift mutagen for salmonella typhimurium ta 1537 inactive at the hgprt locus in human lymphoblasts. | 1977 | 320466 | |
| comparative mutagenicity of icr-191 to s. typhimurium and diploid human lymphoblasts. | concentration-dependent mutagenicity of icr-191 has been measured in salmonella typhimurium strain ta98 and in a diploid human cell line. in both cell systems, approximately equigenerational exposure produced mutation linearly related to concentration in the lower range of icr-191 concentrations tested. saturation behavior was observed in the human cell assay but not in the bacterial assay. however, a 25-fold greater concentration of icr-191 was required to induce a significant rise in the mutan ... | 1977 | 320468 |
| [spondylitis caused by salmonella typhimurium (author's transl)]. | described is a case of spondylitis caused by salmonella typhimurium. according to literature osteomyelitis and spondylitis are rare as local manifestation of a salmonella infection. spondylitis caused by salmonella typhimurium, the most common species, is almost unknown. the problems in diagnosis and therapy are discussed. | 1977 | 320772 |
| [drug resistance of phage types of salmonella typhimurium (author's transl)]. | antimicrobial susceptibility testing (disk diffusion test) and phage typing (method according to anderson, performed by prof. brandis, bonn) of 703 strains of salmonella typhimurium from humans, isolated in essen and surrounding during 1972 to 1975, was performed to dertermine whether characteristic patterns of drug resistance were associated with a single phage type or not. the most frequently isolated phage types are phage type 17 (12.2%), 12 (10.1%), 49 (8.1%), 15a (5.7%), 2 (3,3%) and the un ... | 1977 | 320791 |
| [epidemiologic relationship of infections with salmonella typhimurium in switzerland studied by phage typing (author's transl)]. | in the area, controlled by the institute of microbiology of st. gall, 262 s. typhi murium strains could be isolated during 1973. by means of phage typing, according to guinee, 20 different phage types as well as 6 additional atypically reacting strains, with characteristic atypical pattern, were recognized. the phage type 650 was most frequently encountered (37.0%) folowed by types 61 (20.2%) and 505 (10.3%). an intensive change in phage types was noted among 114 cases, observed over 7 months, i ... | 1977 | 320792 |
| nuclear magnetic resonance and fluorescence studies of substrate-induced conformational changes of histidine-binding protein j of salmonella typhimurium. | the histidine-binding protein j of salmonella typhimurium binds l-histidine as a first step in the high-affinity active transport of this amino acid across the cytoplasmic membrane. high-resolution nuclear magnetic resonance spectroscopy has been used to monitor the conformation of histidine-binding protein j in the presence and absence of substrate. evidence is presented to show that this binding protein undergoes a conformational change involving a substantial number of amino-acid residues (in ... | 1977 | 321019 |
| partial derepression of the isoleucine-valine enzymes during methionine starvation is salmonella typhimurium. | methionine starvation of methionine auxotrophs in the presence of excess branched-chain amino acids results in a partial derepression of the isoleucine and valine enzymes. reversed-phase chromatography indicated that isoleucine, valine and leucine trna were altered during methionine starvation. in addition, the total trna isolated from cells under these conditions were undermethylated. the observed derepression may be caused by the inability of methyl-deficient trna's to participate adequately i ... | 1977 | 321028 |
| the origin of the sulfur atom in thiamine. | the mode of biosynthesis of the thiazole moiety of thiamine, 4-methyl-5beta-hydroxyethyl thiazole (mhet) was studied using salmonella typhimurium as test organism. it was shown by isotope incorporation experiments, that the sulfur atom, but not carbon-3, of cysteine is incorporated into mhet, indicating a separation of the sulfur atom of cysteine from the carbon chain during incorporation. isotope competition experiments revealed that the incorporation of [35s]cysteine is not significantly dilut ... | 1977 | 321036 |
| physiochemical consequences of opsonization of salmonella typhimurium with hyperimmune igg and complement. | partition in an aqueous, two-polymer phase system containing dextran and polyethylene glycol was employed to investigate the physico-chemical changes inflicted upon the cell surface of a smooth strain of salmonella typhimurium by the binding of antibody igg and complement. the minimum antibody concentration for increased phagocytosis in vitro was approximately the same as that for a significant change in two-phase partition, ca 8000 mol/bacterium, whereas a lower concentration, less than 4000 mo ... | 1977 | 321337 |
| comparison of the virulence of o:9,12 and o:4,5,12 salmonella typhimurium his+ transductants for mice. | the purpose of these experiments was to determine whether qualitative differences in the o repeat unit of the lipopolysaccharide of pathogenic salmonella species affected virulence for mice. o:4,5,12 and o:9,12 sister his+ transductants were derived from a virulent salmonella typhimurium. fermentation markers were introduced by transduction to differentiate these strains, and the strains were used as mixed challenge to cf1 and c57b1/6j mice. liver and spleen cultures of the mice of various inter ... | 1977 | 321351 |
| fine-structure map of the histidine transport genes in salmonella typhimurium. | afine-structure genetic map of the histidine transport region of the salmonella typhimurium chromosome was constructed. twenty-five deletion mutants were isolated and used for dividing the hisj and hisp genes into 8 and 13 regions respectively. a total of 308 mutations, spontaneous and mutagen induced, have been placed in these regions by deletion mapping. the histidine transport operon is presumed to be constituted of genes dhua, hisj, and hisp, and the regulation of the hosp and hisj genes by ... | 1977 | 321422 |
| physical characterization of a plasmid cointegrate containing an f'his gnd element and the salmonella typhimurium lt2 cryptic plasmid. | a recombinant plasmid (pas19) isolated from a derivative of salmonella typhimurium lt2, containing the strain lt2 cryptic plasmid and an f'his gnd element, has been physically characterized. the pas19 plasmid contour length equals the sum of the contour lengths of the cryptic plasmid and f'his gnd element. deoxyribonucleic acid (dna)-dna hybridization experiments demonstrated that whereas the pas19 plasmid exhibits extensive dna homology with both the cryptic plasmid and the f'his gnd element, t ... | 1977 | 321435 |
| bacteriophage-typing designations of salmonella typhimurium. | the phage-typing scheme of callow (1959) has been extended. the original number of types was 34; this has now risen to 207. tables are presented which show the provisional type designations and the definitive designations now being introduced. | 1977 | 321679 |
| mutagenicity for salmonella typhimurium of urine obtained from humans receiving nitrofurantoin. | urine samples from 12 humans receiving oral therapeutic doses of nitrofurantoin were mutagenic for salmonella typhimurium strain ta 100 and nonmutagenic for strain ta 100-fr1. mutagenic activity of the urine was not increased by treatment with beta-glucuronidase. spot mutation assay of the chromatogram of urine revealed that the mutagenic activity of the urine was mainly due to unmetabolized nitrofurantoin. | 1977 | 321796 |
| regulation of bacteriophage p22 dna synthesis and repressor levels in p22cly infections. | a rifampin-resistant mutant of salmonella typhimurium carries an altered rna polymerase. wild-type (c+) phage p22 displays clear plaques and a reduced lysogenization frequency on this mutant host. the cly mutants of p22 were isolated on the basis of their ability to lysogenize such mutant hosts. two classes of regulatory events, both of which are dependent on p22 gene c1 activity, are necessary for the establishment of lysogeny in p22. the positive events culminate in repressor synthesis; the ne ... | 1977 | 321806 |
| localization of pfl gene by transductional study of the gal-aro a segment of the salmonella typhimurium lt2 chromosome. | 1977 | 321941 | |
| identification of a protein methyltransferase as the cher gene product in the bacterial sensing system. | methylation of membrane-bound proteins with apparent molecular weights around 65,000 does not occur in mutants of the generally nonchemotactic cher class of salmonella typhimurium. this was shown to be due to the lack of a protein methyltransferase in these mutants by means of an in vitro assay using soluble proteins, membranes, and s-adenosylmethionine as the methyl donor. the methylase from the wild type was purified, characterized, and shown to be of molecular weight 38,000. it is specific fo ... | 1977 | 322131 |
| effects of crowding of mice on humoral antibody formation and protection to lethal antigenic challenge. | the effects of grouping (crowding) on humoral antibody response to typhoid paratyphoid vaccine and subsequent protection from a minimal lethal challenge dose of salmonella typhimurium were studied in white swiss-webster mice. the data show a trend between the degree of crowding and antibody response. geometric mean titers of high density grouped mice were significantly lower than the geometric mean titers of the less crowded mice. also, there were significantly less antibody responders in the hi ... | 1977 | 322186 |
| generalized indicator plate for genetic, metabolic, and taxonomic studies with microorganisms. | we have developed an indicator plate that works well for diverse types of substrates and microorganisms. the plates are inexpensive and easy to prepare. the essential components are agar, buffer, growth-supporting nutrients, a test substrate, and 2,3,5-triphenyl tetrazolium chloride (ttc). using various strains of salmonella typhimurium and escherichia coli, we have studied and defined the contribution of each component to the satisfactory function of the plate. colonies capable of catabolizing ... | 1977 | 322611 |
| comparative electrophilicity, mutagenicity, dna repair induction activity, and carcinogenicity of some n- and o-acyl derivatives of n-hydroxy-2-aminoflourene. | n-myristoyloxy-n-acetyl-2-aminofluorene, n-acetoxy-n-myristoyl-2-aminofluorene, n-myristoyloxy-n-myristoyl-2-aminofluorene, and n-hydroxy-n-myristoyl-2-aminofluorene each yielded a high incidence of sarcomas in male rats within 5 to 7 months after s.c. injection of 64 micronmoles in divided doses. n-acetoxy-n-acetyl-2-aminofluorene and n-hydroxy-2-acetylaminofluorene, although potent carcinogens at the s.c. site, were less active than the above derivatives with a myristoyl substituent. n-sulfono ... | 1977 | 322856 |
| isolation of the glucuronic acid conjugate of n-hydroxy-4-aminobiphenyl from dog urine and its mutagenic activity. | the glucuronic acid conjugate of n-hydroxy-4-aminobiphenyl (noh-4-abp) has been isolated in relatively pure form from the urine of dogs given 4-aminobiphenyl, utilizing molecular size, ion exchange, adsorption, and partition chromatography. this conjugate is an active mutagen in salmonella typhimurium strains ta1538 and ta98 but not in ta1535 or ta1537. noh-4-abp and 4-nitrosobiphenyl are also highly active in ta1538 and ta98 and inactive in ta1535 and ta1537. these observations support the conc ... | 1977 | 322861 |
| role of zinc in the abatement of hepatocellular damage and mortality incidence in endotoxemic rats. | intraperitoneal administration of zinc (znip) as zinc chloride prior to or simultaneously with a lethal quantity of intraperitoneally administered salmonella typhimurium endotoxin significantly protected rats against toxin-induced mortality and hepatocellular damage. pretreatment with amounts of zinc chloride ranging from 0.4 to 2.0 mg/100 g of body weight resulted in 80 to 100% survival compared with 10% survival in untreated control rats at 24 h after endotoxin treatment. zinc chloride treatme ... | 1977 | 323146 |
| chemotactic mechanism of salmonella typhimurium: preliminary mapping and characterization of mutants. | some new, generally nonchemotactic mutants of salmonella typhimurium were isolated and they, together with previously isolated mutants and some from other investigators, were mapped. most of the mutants were classified in nine complementation groups, which are probably individual genes. of these, five map at the end of the flagella region and appear in the order motb-(chewchep)-chex-cheq-cher-flac. two of the mutations, cheu and chev, map in the flaq and flaaii genes, respectively. the remaining ... | 1977 | 323229 |
| degradation of escherichia coli beta-galactosidase fragments in protease-deficient mutants of salmonella typhimurium. | the degradation rates of several mutationally generated fragments of escherichia coli beta-galactosidase were determined in wild-type strains of salmonella typhimurium and in mutant salmonella strains lacking several proteases and peptidases. three termination fragments (produced by lacz545, lacz521, and laczx90) and one internal reinitiation (restart) fragment [laczpi(1)] are degraded in wild-type salmonella strains at the same rates observed in wild-type escherichia coli strains. mutations tha ... | 1977 | 323234 |
| identification of a gamma-glutamyl methyl ester in bacterial membrane protein involved in chemotaxis. | evidence is presented that a methyltransferase enzyme, previously shown to be necessary for chemotaxis and identified as the cher gene product, catalyzes the formation of a gamma-glutamyl methyl ester in one or more membrane proteins of salmonella typhimurium. the rates of release of methyl label from the methylated protein in acid, base, and hydroxylamine are consistent with a methyl ester and not with a methylated imidazole, guanidino, or amino group. a gamma-glutamyl methyl ester was isolated ... | 1977 | 323255 |
| protective effects of passively transferred immune t- or b-lymphocytes in mice infected with salmonella typhimurium. | purified populations of bone marrow-derived (b-) lymphocytes and thymus-derived (t-) lymphocytes were obtained from c3d2f1 hybrid mice shown to be immune to salmonella typhimurium. these subpopulations of lymphocytes were injected into normal mice; four days later the animals were challenged with 50 50% lethal doses of s. typhimurium, and viable bacteria in livers, spleens, and blood were counted at various intervals after challenge. on day 8 after challenge, the mice supplemented with b-lymphoc ... | 1977 | 323381 |
| membrane fluidity and chemotaxis: effects of temperature and membrane lipid composition on the swimming behavior of salmonella typhimurium and escherichia coli. | 1977 | 323503 | |
| mutagenicities of quinoline and its derivatives. | quinoline, recently reported to be carcinogenic in rats [12], was mutagenic to salmonella typhimurium tester strains ta100 and ta98 in the presence of the metabolic activation system s-9 mix. 2-chloroquinoline, a non-carcinogen [12], was non-mutagenic with or without s-9 mix. 8-hydroxyquinoline, which is t known to be carcinogenic, was mutagenic with s-9 mix to both bacterial strains. the mutagenicities of 17 other quinoline derivatives that are not known to be carcinogenic were tested, and 12 o ... | 1977 | 323699 |
| inhibition of histidyl-trna-adenosine triphosphate phosphoribosyltransferase complex formation by histidine and by guanosine tetraphosphate. | formation of the complex between the first enzyme of histidine biosynthesis from salmonella typhimurium, atp phosphoribosyltransferase [1-(5'-phosphoribosyl)-atp: pyrophosphate phosphoribosyltransferase; ec 2.4.2.17], and histidyl-trna is shown to be inhibited by l-histidine and by guanosine-5'-diphosphate-3'-diphosphate in the presence of histidine. higher histodine levels make guanosine tetraphosphate a more effective inhibitor. relatively high concentrations of guanosine-5'-triphosphate also ... | 1977 | 323857 |
| mutagenic activity of nitrite-treated foods: human stomach cancer may be related to dietary factors. | by the salmonella typhimurium test, extracts of japanese raw fish treated in the laboratory with nitrite showed mutagenic activity which is prevented by addition of ascorbate. extracts from similarly treated beef and hot dogs were nonmutagenic. the data conform to a working concept that the high stomach cancer incidence in japanese and certain other populations may be due to specific dietary factors of an alkylnitrosamide type. | 1977 | 323974 |
| prevention of salmonella typhimurium infection inpoultry by pretreatment of chickens and poults with intestinal extracts. | day-old chickens or turkey poults when pretreated with an oral dose of intestinal fluid froma healthy adult bird, were considerably more resistant to the subsequent establishment of salmonella typhimurium in their intestinal tract than were non-treated chickens or turkey poults. caecal fluid was more effective as a pretreatment than were washings taken from other parts of the gastro-intestinal tract of a healthy adult bird. this increased resistance of pretreated chickens or poults is thought to ... | 1977 | 324465 |
| studies on the mutagenicity of nitrofurans in salmonella typhimurium. | 1977 | 324478 | |
| reiter's disease after salmonella typhimurium enteritis. | 1977 | 324575 | |
| the mutagenicity of methylbenzylnitrosamine and its alpha-acetoxy derivatives. | biological activity of the alpha-acetoxy derivatives of methylbenzylnitrosamine was evaluated using tester strains of salmonella typhimurium. compound iii, oxidized on the benzyl moiety, was more toxic and more mutagenic than compound iv, oxidized on the methyl side chain. compound iv was weakly toxic and was non-mutagenic at the concentrations tested. the presence or absence of the uvrb repair system had no effect on the toxicity of either compound ii or iv. neither the alpha-oxidized compounds ... | 1977 | 324607 |
| inhibitory effects of selenium of the mutagenicity of 2-acetylaminofluorene (aaf) and aaf derivatives. | selenium (se) decreased the mutagenicity of 2-acetylaminofluorene (aaf), n-hydroxy-2-acetylaminofluorene (n-oh-aaf) and n-hydroxyaminofluorene (n-oh-af) in the salmonella typhimurium ta 1538 bacterial tester system. metabolism of aaf and n-oh-aff to the active mutagen, n-oh-af, was accomplished by rat liver extracts. graded decreases in mutagenicity with increasing se concentrations were observed for each of the three mutagens. se decreased the mutagenicity of aaf, n-oh-aaf and n-oh-af to 65, 68 ... | 1977 | 324608 |
| mutagenicities of protein pyrolysates. | smoke condensate obtained by pyrolysis of proteins, such as lysozyme and histone, was shown to be mutagenic to salmonella typhimurium ta100 and ta98. in vitro metabolic activation by a mammaliam postmitochondrial enzyme preparation (s-9 mix) was required. smoke condensates obtained by pyrolysis of dna, rna, starch and vegetable oil were slightly mutagenic, whereas those from pyrolysis of l- and d-tryptophan and 5-hydroxy-d,l-tryptophan were very strongly mutagenic with metabolic activation by s- ... | 1977 | 324609 |
| isolation, purification and properties of an intermediate in 3-deoxy-d-manno-octulosonic acid--lipid a biosynthesis. | incomplete lipid a has been purified from a mutant of salmonella typhimurium which is temperature-sensitive both in synthesis of 3-deoxy-d-manno-octulosonic acid 8-phosphate (docla-8-p) and in growth. pulse-chase experiments have shown that the incomplete lipid a molecule is the intermediate in the biosynthesis of the docla-lipid a portion of lipopolysaccharides. the purification procedure included deae-cellulose chromatography and electrodialysis. a highly water-soluble precursor material was o ... | 1977 | 324763 |
| chromosomal location of a structural gene for the rna polymerase sigma factor in escherichia coli. | a set of f' strains of escherichia coli k-12 partially diploid for various chromosomal segments has been examined for possible gene dosage effects in the synthesis of sigma factor of the dna-dependent rna polymerase (rna nucleotidyltransferase; nucleoside-triphosphate:rna nucleoti-dyltransferase, ec 2.7.7.6). it was found that all f' strains diploid for the dnag region synthesize sigma at rates two to three times higher than other f' or f- strains. moreover, strains of salmonella typhimurium har ... | 1977 | 325555 |
| a gene from escherichia coli affecting the sigma subunit of rna polymerase. | the rna polymerase sigma subunits of escherichia coli k, e. coli c, and salmonella typhimurium can be resolved by electrophoresis. using this technique, we have analyzed salmonella strains carrying f' plasmids from e. coli k in order to map the gene for the sigma factor. partial diploid analyses show the location of the sigma gene at 62-66 min on the e. coli genetic map. this gene is cotransducible with toic and dnag, at 66 min. | 1977 | 325556 |
| use of a distant reporter group as evidence for a conformational change in a sensory receptor. | a highly sensitive method for demonstrating ligand-induced conformational changes in protein molecules in solution is described. the method utilizes an environmentally sensitive reporter group that is known to be distant from the active site. in the present application a conformational change is demonstrated in the galactose receptor of salmonella typhimurium, involved in bacterial sensing and transport, by means of an extrinsic fluorophore, 5-iodoacetamidofluorescein, attached at a single meth ... | 1977 | 325561 |
| fatal generalized bcg histiocytosis. | an infant was vaccinated at the age of 3 days with bcg vaccine. at the age of 3 years 10 months he developed an infection by salmonella typhimurium. the infection persisted with recurrent episodes of fever, peri-nephritic abscess, abscesses of lymph nodes, hepatomegaly, splenomegaly and paravertebral and retro-peritoneal abscesses, from which salmonella were isolated. at the age of 6 years and 2 months later. at post-mortem examination there were widespread histiocytic nodules in many organs, fr ... | 1977 | 325838 |
| [change in phagocytic activity toward the agent of tularemia in highly sensitive animals with mixed infections]. | an increase of the ingestive and digestive capacity of neutrophils to the homologous causative agent and tularemia microbe was revealed by the opsonophagocytic test in microtus arvalis, albino mice and guinea pigs infected with sublethal yersinia pseudotuberculosis and salmonella typhimurium doses. in subsequent tularemia infection some of the animals displayed a reduction of the septicemia intensity, prolongation of the disease and elevation of the susceptibility threshold. period of manifestat ... | 1977 | 325967 |
| [study of a "rfa" locus coding for cell wall lipopolysaccharide core biosynthesis in "shigella flexneri" f6s (author's transl)]. | the rfa-7 lipopolysaccharide core mutation carried by the r mutant f680, derived from shigella flexneri f6s serotype 5b, has been mapped by conjugation and transduction experiments. the results show a chromosomal distance of about 1 min between rfa-7 and mtl. such a position would be similar to those of rfa genes in escherichia coli k12 and salmonella typhi-murium lt2. conjugational transfer of e. coli k12 rfa+ genes to mutant f680 restored s. flexneri o-specificity. chemical analyses performed ... | 1977 | 326120 |
| toxicity and mutagenicity of hexavalent chromium on salmonella typhimurium. | four hexavalent and two trivalent chromium compounds were tested for toxicity and mutagenicity by means of the salmonella typhimurium/mammalian-microsome test. all hexavalent compounds yielded a complete inhibition of bacterial growth at doses of 400 to 800 mug/plate, a significant increase of his(+) revertant colonies at doses ranging from 10 to 200 mug, and no effect at doses of less than 10 mug. the distinctive sensitivity of the four salmonella strains tested (ta1535, ta1537, ta98, and ta100 ... | 1977 | 326184 |
| use of enzyme-labeled antibodies to detect salmonella in foods. | an indirect enzyme-labeled antibody technique (elat), in which salmonella typhimurium was used as a model, was developed as a method to detect salmonella in food samples. a cellulose-acetate membrane filter, the matrix for detection, was placed on a membrane-filter base and overlaid with a multiwelled lucite template. mixed broth enrichment cultures were dispensed in the template wells, and cells were spotted onto the membrane via suction. after fixation, the membranes were immersed in rabbit an ... | 1977 | 326193 |
| susceptibility of lipopolysaccharide mutants to the bactericidal action of human neutrophil lysosomal fractions. | acetate extracts of purified human neutrophil granules (a mixed population containing specific and azurophil granules) were dialyzed against phosphate-buffered saline (ph 7.0) and tested for bactericidal activity against smooth parent and rough mutant, gram-negative bacteria. rough (re) mutants of escherichia coli, salmonella typhimurium, and salmonella minnesota were exquisitely more sensitive to extracts of human polymorphonuclear leukocyte granules than were their smooth (s) parents. the mean ... | 1977 | 326666 |
| regulation of l-cystine transport in salmonella typhimurium. | a kinetic analysis of l-cystine uptake in wild-type salmonella typhimurium indicates the presence of at least two, and possibly three, separate transport systems. cts-1 accounts for the majority of uptake at 20 mum l-cystine, with a vmax of 9.5 nmol/min per mg and a km of 2.0 mum; cts-2 is a low-capacity, higher-affinity system with a vmax of 0.22 nmol/min per mg and a km of 0.05 mum; a third, nonsaturable process has been designated cts-3. we find that wild-type cts-1 levels are at least 11 tim ... | 1977 | 326753 |
| lipid a mutants of salmonella typhimurium. characterization of a conditional lethal mutant in 3-deoxy-d-mannooctulosonate-8-phosphate synthetase. | 1977 | 326782 | |
| detection of messenger rna from the isoleucine--valine operons of salmonella typhimurium by heterologous dna-rna hybridization: involvement of transfer rna in transcriptional repression. | a hybridization assay using escherichia coli k-12 dna isolated from the specialized transducing bacteriophage gammaci857st68h80 dilv was used to examine the rate of synthesis of the messenger rna's (mrna) derived from the isoleucine-valine (ilv) gene cluster of salmonella typhimurium. in all cases examined, changes in ilv enzyme levels could be correlated with changes in the rate of synthesis of ilv mrna. several well characterized regulatory mutants of s. typhimurium had rates of synthesis of ... | 1977 | 327261 |
| [pre-disposing factors and treatment problems in systemic invasion due to salmonella typhimurium in childhood]. | 1977 | 327297 | |
| the use of rec-bacteria for testing of carcinogenic substances. | a series of rec-escherichia coli strains were tested for their sensitivity to four known carcinogenic compounds by examination of a zone of inhibited bacterial growth around a central well containing the test chemical. the mutants reca-, recb-, recc-, and reca- recb- recc- were all more sensitive to the mutagens than the parental strain ab1157. the recb- recc- strain was examined with a larger series of compounds and was found to respond to many of the substances in a similar way as the salmonel ... | 1977 | 327303 |
| relative efficiencies of a series of square-planar plantinum(ii) compounds on salmonella mutagenesis. | twelve pt(ii) compounds have been tested for mutagenicity on salmonella typhimurium (strain ta 100). very high mutagenic activities were found for the cis derivatives. a correlation is suggested between these results and a formerly described model of chemical reactivity towards dna, according to which cis derivatives from intra-strand chelates with guanine. a smaller activity was found with monodentate complexes with dna. | 1977 | 327304 |
| mutagenicity of anti-cancer nitrobenzofuroxans. | anti-leukaemically active benzofuroxans were tested for mutagenicity in salmonella typhimurium. mutagenicity was not found to be correlated to the previously established anti-leukaemic activity. one anti-leukaemically inactive compound after exposure to liver microsomal enzymes proved the most mutagenic of the derivatives for ta100, whereas after similar treatment, the mutagenicity of the most potent anti-leukaemic compound was reduced. all twelve derivatives tested were mutagenic in a base-subs ... | 1977 | 327305 |
| detection of mutagenic activity in particulate air pollutants. | ames's strains of salmonella typhimurium were used to evaluate the mutagenic activity of airbone particulate materials collected at six different points in the industrial area of ohmuta and the residential area fukuoka. tests were done in presence of rat-liver s-9 fraction isolated from rats that had been treated with aroclor 1254. when the number of revertant colonies per plate was plotted against the amount of methanol extract of particulate air pollutants, using strain ta98, approximately lin ... | 1977 | 327308 |
| mutagenic studies with acrylonitrile. | the mutagenicity of acrylonitrile (vinyl cyanide, propenenitrile) has been demonstrated in the ames salmonella typhimurium/liver microsome assay system. acrylonitrile, in the presence of a mouse liver homogenate produced mutations in the ta 1535, ta 1538 and ta 1978 strains. exposure of the bacteria was achieved by spotting the acrylonitrile on a "lawn" of salmonella, by shaking a reaction mixture consisting of bacteria, liver homogenate and acrylonitrile, and by exposing the homogenate and bact ... | 1977 | 327311 |
| mutagenic activity of amino acid pyrolyzates in salmonella typhimurium ta 98. | pyrolyzates of 25 amino acids and 5 indole derivatives were tested for mutagenicity in the histidine-requiring mutant salmonella typhimurium ta 98. significant mutagenic activity was detected with pyrolyzates of most of the amino acids. these pyrolyzates required a liver microsomal fraction, as representative of mammalian metabolism, to be detected as mutagens. among the pyrolyzates tested, the highest mutagenic activity was observed with that of l-tryptophan. as little as 10 microgram of the py ... | 1977 | 327312 |
| mutagenic evaluation of nitrofuran derivatives in salmonella typhimurium, by the micronucleus test, and by in vivo cytogenetics. | 1977 | 327313 | |
| mutagenicity tests on anthelmintics: microsomal activation of viprynium embonate to a mutagen. | eight anthelmintic preparations readily available in australia were tested for mutagenicity in the salmonella typhimurium test system. a slightly modified version of the procedure recommended by ames et al. [2] was adopted, in that the test samples were placed in "wells" cut out of the agar of a plate previously seeded with the appropriate tester strain. addition of a mixture of rat liver microsomal enzymes and appropriate co-factors ("s-9 mix") to one of the two wells on a single plate allowed ... | 1977 | 327314 |
| mutagenicity of nitrovin--a nitrofuran feed additive. | nitrovin, a nitrofuran feed additive, is shown to be directly mutagenic in salmonella typhimurium ta 98 and ta 100 between 0.1 and 2.5 microgram per plate (0.09--2.3 micrometer). addition of a rat-liver homogenate reduces the mutation rates. nitrovin inhibits growth of the same bacteria in suspension cultures at concentrations above 0.09 micrometer. | 1977 | 327315 |
| relation between chemical constituents of tobacco and mutagenic activity of cigarette smoke condensate. | mutagenic activities of cigarette smoke condensate were assayed in the presence of s-9 mix using salmonella typhimurium ta 98. the results were examined in relation to chemical data of tobacco leaves. among the nitrogenous constituents examined, the contents of total nitrogen and protein nitrogen and the soluble nitrogenous fraction were positively and significantly related to an increase in mutagenic activity of the smoke condensate, whereas nicotine and nitrate were not important in contributi ... | 1977 | 327316 |
| mutagenic activity of quercetin and related compounds. | the mutagenic activities of several flavonoids and flavonoid metabolites were examined by means of salmonella typhimurium mutants that reveal base-pair substitution and frameshift mutagens. of the compounds tested (naringin, rutin, neohesperetin, hesperetin, dihydroquercetin, quercetin, quercetin pentaacetate, permethylquercetin, m-hydroxyphenylacetic acid, and m,p-dihydroxyphenylacetic acid), only quercetin was mutagenic without microsomal activation. with activation, however, the mutagenic act ... | 1977 | 327550 |
| r factor types found in salmonella typhimurium and escherichia coli isolated from calves in a confined environment. | typing of r factors by genetic properties was done with salmonella typhimurium and escherichia coli isolated from calves on a feedlot where epizootics of clinical or subclinical calf salmonellosis had repeatedly occurred during 5 years. forty-nine r factors from s typhimurium were fi- (no fertility inhibition) and spp- (no restriction against phage lambda vir). twenty-three (46.9%) of them belonged to compatibility group ialpha and the remainder were nontypable. fourteen r factors from e coli be ... | 1977 | 327875 |
| beta-lactamase-directed barrier for penicillins of escherichia coli carrying r plasmids. | strains of escherichia coli and salmonella typhimurium carrying r plasmids, which were obtained from ampicillin-resistant clinical isolates of e. coli and klebsiella spp. and specified either the type iiia (tem-type) or type va (oxacillin-hydrolyzing) beta-lactamase, are resistant not only to ampicillin but also to carbenicillin and sulbenicillin. the latter two derivatives, however, are poorly hydrolyzed in vitro by the beta-lactamases. although values of k(m) of the enzymes are lower for sulbe ... | 1977 | 327924 |
| stereoselectivity and stereospecificity of the alpha,beta-dihydroxyacid dehydratase from salmonella typhimurium. | 1. in addition to the known 2r,3r- and 2r, 3s-2,3-dihydroxy-3-methylpentanoic acids (dhi), the 1s,3s- and ss,dr-isomers were prepared. 2s-2,3-dihydroxy-3-methylbutanoic acid (dhv) was also prepared in addition to the known 2r-isomer. 2. the six dihydroxy acids were examined for their ability to promote the growth of isoleucine-valine (ilv)-requiring strains of salmonella typhimurium and to serve as substrates for the alpha,beta-dihydroxyacid dehydratase of the same organism. 3. only 2r,3r-2,3-di ... | 1977 | 328058 |
| mutagenicity testing of styrene and styrene epoxide in salmonella typhimurium. | 1977 | 328090 | |
| isolation of mutants conditionally blocked in the biosynthesis of the 3-deoxy-d-manno-octulosonic-acid--lipid-a part of lipopolysaccharides derived from salmonella typhimurium. | a procedure is described for the selection of conditional 3-deoxy-d-manno-octulosonic-acid--lipid a mutants which depends on temperature sensitivity for both synthesis of complete lipopolysaccharide and for growth. using this procedure new types of mutants were isolated which cease growth and accumulate lipid a precursors following a shift to nonpermissive temperatures. all precursor molecules differ in their charge as judged by deae-cellulose chromatography. while they all contain glucosamine, ... | 1977 | 328282 |
| ochre suppression in salmonella typhimurium. | a bacterial strain was constructed which permitted positive selection for ochre suppressor mutations as well as for the loss of suppressor function. a derivative bearing an ochre suppressor mutation was selected following mutagenesis with n-methyl-n-nitroso-n'-nitroguanidine. the suppressor-bearing strain was treated with nitrous acid to eliminate suppressor function by mutation, and a strain lacking suppressor activity was selected. the selected strain which had lost suppressor function was the ... | 1977 | 328342 |
| role of endotoxin contamination in ribiosomal vaccines prepared from salmonella typhimurium. | ribosomal vaccines prepared from salmonella typhimurium sr-11 and 6707 an re mutant bacterium of strain lt2, were effective immunogens in a/j and c3h/hedub inbred mice. only sr-11 ribosomes were able to induce significant protection in c3h/hej mice. c57bl/6j mice were not protected by either ribosomal preparation. a/j mice were protected against salmonella infection by purified sr-11 endotoxin preparations. neither the c3h/hedub, the c3h/hej, nor the c57bl/6j mice were protected by the endotoxin ... | 1977 | 328399 |
| phosphoenolpyruvate:sugar phosphotransferase system in ancalomicrobium adetum. | ancalomicrobium adetum possesses a membrane-associated phosphoenolpyruvate:sugar phosphotransferase system, the components of which exhibited enzymatic cross-reactivity with those from salmonella typhimurium. | 1977 | 328495 |
| the immunization of mice and calves with gal e mutants of salmonella typhimurium. | a galactose epimeraseless (gal e) mutant of salmonella typhimurium was investigated in mice and calves for its suitability as a live vaccine. in mice, a very highly significant difference in the mortality rates was observed when vaccinated and non-vaccinated animals were challenged with virulent strains of s. typhimurium and s. dublin. in calves, doses of 10(6) and above of gal e mutant injected subcutaneously provided highly significant protection both in terms of mortality and prevalence of sy ... | 1977 | 328767 |
| physicochemical consequences of opsonization: perturbation of liposomal membranes by salmonella typhimurium 395 ms opsonized with igg antibodies. | when phagocytosis-resistant salmonella typhimurium 395 ms bacteria sensitized with anti-ms igg antibodies were incubated with liposomes composed of phosphatidylcholine, cholesterol, and dicetylphosphate, a previously sequestered liposomal marker (4-methylumbelliferylphosphate) was released. unsensitized or f(ab')2-sensitized bacteria had no such effect. this perturbation was neither dependent upon negatively charged dicetylphosphate nor upon cholesterol. it was further evident that palmitoyl-pol ... | 1977 | 328778 |
| [salmonella typhimurium isolated from the spinal fluid of 2 children]. | in this article isolation of s. typhimurium bacteria from cebrospinal fluid of two children is reported. | 1977 | 329073 |
| internal reinitiation of translation in polar mutants of the trpb gene of salmonella typhimurium. | 1977 | 329111 | |
| on the ability of salmonella typhimurium cells to form deoxycytidine nucleotides. | it is known that cdd- s. typhimurium mutants selected for resistance to 5-fluorodeoxycytidine (fdcyd) possess no deoxycytidine kinase activity. the present study postulates that this method of screening selects double mutants defective in cytidine deaminase and in deoxycytidine kinase. to prove this hypothesis, the cdd mutant of s. typhimurium was constructed by p1-mediated transfer of ccd- gene into a new genetic background, and the activity of deoxycytidine kinase was assayed. transductants ex ... | 1977 | 329115 |
| effect of mutant host rna polymerase on the bifunctional activities of p22 gene c1. | the product of phage p22 gene c1 has two functions: (1) it promotes synthesis of repressor and (2) during the first minutes of infection it retards expression of some lytic genes. we call the second, negative function "c1 retardation". we investigated c1 retardation in a mutant host of salmonella typhimurium that is resistant to rifampicin and carries an altered rna polymerase. no c1 retardation of dna synthesis was detectable in this host after infection with wild-type phages. this elimination ... | 1977 | 329118 |
| [salmonella typhimurium infection during systemic lupus erythematosus]. | 1977 | 329376 | |
| the tendency of smooth and rough salmonella typhimurium bacteria and lipopolysaccharide to hydrophobic and ionic interaction, as studied in aqueous polymer two-phase systems. | in aqueous two-phase system, the partition of bacteria and lipopolysaccharide from a rough (r) strain (rd-mutant) of salmonella typhimurium is influenced by polymers with covalently linked hydrophobic groups indicating hydrophobic structures accessible at the cell surface. furthermore, the partition of the r bacteria is influenced by a number of inorganic positive and negative ions, presumably as a consequence of interaction with negatively charged surface structures. in contrast, smooth (s) bac ... | 1977 | 329639 |
| nutritional effects of salmonellosis in mice. | mice infected with a standard challenge of salmonella typhimurium manifest a number of changes associated with endotoxemia. these changes result in profound alterations in the nutritional and metabolic status of the host. food and water intake approaches levels of total inanition, blood glucose declines more rapidly than in fasted controls, hepatic phosphoenolpyruvate carboxykinase (the enzyme that is rate limiting in gluconeogenesis) shows diminished activity and loss of cortisol inducibility, ... | 1977 | 329666 |
| histidinol dehydrogenase from salmonella typhimurium and escherichia coli. purification, some characteristics and the amino acid sequence around a reactive thiol group. | the purification and some physical properties of histidinol dehydrogenase, l-histidinol-nicotinamide adenine dinucleotide oxido-reductase (ec 1.1.1.23) from either salmonella typhimurium or escherichia coli are reported in this paper. modification of histidinol dehydrogenase with one equivalent of n-(4-dimethylamino-3,5-dinitrophenyl)maleimide at ph 6.8 yields an enzyme that is inactive toward the oxidation of l-histidinol. the modified cysteine residue was located in an acid insoluble tryptic c ... | 1977 | 329890 |
| mutagenicity of smoke condensates from cigarettes, cigars and pipe tobacco. | smoke condensates from cigarettes, cigars and pipe tobacco were mutagenic on salmonella typhimurium ta100 and ta98 when activated with rat liver microsomal system. mutagenicity of a unit weight of smoke condensate was rather high in cigars, low in pipe tobacco and intermediate in cigarettes. specific mutagenic activity was almost comparable among smoke condensates from low- to high-tar cigarettes, although some variations were observed depending upon the country producing the cigarettes. marked ... | 1977 | 329976 |
| transfer of episome f'lac+ and chromosomal trp+ genes from erwinia amylovora to salmonella typhimurium. | the f'lac+ episome of escherichia coli origin was transferred by conjugation with frequencies of 10(-7) to 10(-5) from erwinia amylovora to 14 out of 15 salmonella typhimurium trp female parents. the chromosomal trp+ genes were transferred with frequencies of 10(-7) to 10(-6) only to one trpb and 2 trpd female parents, which have a point mutation in the 2nd and fourth structural genes, respectively, of the tryptophan operon. the transferred male trp+ genes became integrated at the selected sites ... | 1977 | 330120 |
| humoral response to salmonella typhimurium antigens in normal and thymectomized urodele amphibian pleurodeles waltlii michah. | 1977 | 330172 | |
| in vitro mutagenicity of the soil nematicide 1,3-dichloropropene. | the cis- and trans-isomers of 1,3-dichloropropene have been tested in the ames mutagenicity assay system on salmonella typhimurium tester strain ta 1535. both isomers have been found to be mutagenic even without microsomal activation. | 1977 | 330205 |
| a comparison of the amino-terminal sequences of several carbohydrate binding proteins from escherichia coli and salmonella typhimurium. | 1977 | 330247 | |
| infection of hela cells with salmonella typhimurium 395 ms and mr10 bacteria. | after interaction with hela cells cultured in vitro, the fraction of adhering extracellular and that of internalized smooth salmonella typhimurium 395 ms and rough 395 mr10 have been determined by two different techniques. (i) by using the indirect fluorescent-antibody technique on unfixed and acetone-fixed hela cell preparations, intracellular bacteria were considered to become stained only after acetone fixation. (ii) based on the assumption that gentamicin affects only extracellular bacteria, ... | 1977 | 330403 |
| dna degradation in wild-type and repair-deficient strains of salmonella typhimurium exposed to ultraviolet light of photodynamic treatment. | five mutants of salmonella typhimurium strain lt2 trp di (colei)+, initiallly detected because they released little or no colicin when tested on solid medium, proved to be sensitive to ultraviotet light (u.v.). further testing indicated that one of the mutants was deficient in genetic recombination and was probably a reca-type mutant, while three of the others were deficient in dna polymerase activity and appeared to be typical pola mutants. the fifth mutant was less sensitive than the others to ... | 1977 | 330821 |
| testing of some azo dyes and their reduction products for mutagenicity using salmonella typhimurium ta 1538. | a series of ten azo dyes as well as various single ring aromatic amines substituted on the benzene ring were tested for bacterial mutagenicity with salmonella typhimurium ta 1538 using a soft-agar overlay method. two dyes, sudan 2 and chrysoidin induced mutation but only in the presence of a rat liver preparation. chrysoidin was the more active. testing of its reduction products, aniline and 1,2,4-triaminobenzene showed a liver metabolite of the latter compound could be responsible for the mutag ... | 1977 | 331098 |
| a study of the photoinduced mutagenicity of methylene blue. | illumination of salmonella typhimurium strains in the presence of methylene blue resulted in the production of mutations of the base-substitution type. this photodynamic effect mediated by the dye was separable from the genetic event seen when bacteria are illuminated in the absence of added photosensitizers. | 1977 | 331101 |
| biosynthesis of trna in histidine regulatory mutants of salmonella typhimurium. | hisu mutants of salmonella typhimurium are depressed in the histidine operon since they have lower intracellular concentration of histidyl-trnahis. in this paper we present evidences showing that a strain carrying a hisu mutation (hisul206) is altered in a nucleolytic enzyme involved in trna maturation process. the analysis of several hisu mutants indicates that hisu region of bacterial genome may account for more than one function involved in trna biosynthesis. | 1977 | 331266 |
| mutagenicity and cytotoxicity of benz[alpha]anthracene diol epoxides and tetrahydro-epoxides: exceptional activity of the bay region 1,2-epoxides. | three diastereomeric pairs of diol epoxides, two tetrahydro-epoxides, and the k-region oxide of the polycyclic aromatic hydrocarbon benz[a]anthracene were evaluated for mutagenic activity in strain ta 100 of salmonella typhimurium and in line v79-6 of chinese hamster lung cells. the two diastereomeric 1,2-epoxides of the trans-3,4-dihydrodiol of benz[a]anthracene are 15 to 35 times more mutagenic to the bacteria and 65 to 125 times more mutagenic to the mammalian cells than are the diastereomeri ... | 1977 | 331315 |
| [change in the protective activity of the ribosomal fractions of salmonella typhimurium in mutations in the rfa region and the transduction replacement of the rfb region]. | it was shown that mutation in the rfa region causing disturbances in the structure of the basal part of the polysaccharide of the cell wall or the absence of o-specific side chains led to the loss of protective activity of the ribosomal fractions isolated from the cells of the murine typhoid salmonella by sedimentation with dihydrostreptomycine sulphate. ribosomal fractions isolated from the murine typhoid salmonella transductants with the replaced rfb region failed to protect the animals from t ... | 1977 | 331765 |
| mutagenicity of 3a,8a-dihydrofuro[2,3-b]benzofuran, a model of aflatoxin b1, for salmonella typhimurium ta100. | 1977 | 332158 | |
| [salmonella typhimurium as a test system for detecting the mutagenic activity of environmental pollutants. i. the mutagenic action of heavy metal salts in in vivo and in vitro systems without metabolic activation]. | the work presents the data on mutagenic effects of heavy metal salts (zn and cd) on salmonella typhimurium test strains using mutagenicity test in vitro without metabolic activation and host-mediated assay. the techniques used enabled to determine also the types of mutations arising from the exposure to zncl2 and cdcl2. | 1977 | 332590 |
| increased resistance of iron-deficient mice to salmonella infection. | nutritional iron deficiency in mice attenuated salmonella typhimurium infection compared with both iron-substituted littermates and normal diet control animals. | 1977 | 332634 |
| interactions between salmonellae and macrophages of guinea pigs. iv. relationship between migration inhibition and antibacterial action of macrophages. | the in vitro macrophage migration inhibition test was used to detect the development of delayed-type hypersensitivity in guinea pigs infected with salmonella typhimurium. four different preparations from supernatants of s. typhimurium cultures were used as the antigens in this test. they included the concentrated bacterial antigens, the high-molecular-weight (>50,000) antigens, the ammonium sulfate-precipitated antigens, and the ribonuclease-treated antigens. all four antigen preparations were s ... | 1977 | 332643 |
| interaction of salmonella typhimurium with phospholipid vesicles. incorporation of exogenous lipids into intact cells. | incubation of intact cells of salmonella typhimurium with bilayer phospholipid vesicles results in significant transfer of vesicle lipids to the cells. the transfer requires ca2+ or spermine, and is dependent on time, temperature, the concentration and composition of the vesicles, and the nature of the cellular lipopolysaccharide. the process results in bulk transfer of vesicle lipids to the cells rather than reciprocal molecular exchange between vesicles and the outer membrane. all components o ... | 1977 | 332695 |
| translocation of phospholipids between the outer and inner membranes of salmonella typhimurium. | the reversibility and specificity of phospholipid translocation between the inner and outer membrane of salmonella typhimurium has been investigated by incorporating exogenous lipids from phospholipid vesicles into the outer membrane of intact cells. translocation of newly incorporated phospholipids to the inner membrane was demonstrated by decarboxylation of vesicle-derived phosphatidylserine and by recovery of vesicle constituents in both inner and outer membrane fractions. all salmonella phos ... | 1977 | 332696 |
| frameshift mutagenesis in bacteria by 8-methoxypsoralen (methoxalen) in the dark. | we confirm that 8-methoxypsoralen (8-mop) in the dark induces frameshift mutations in both escherichia coli and salmonella typhimurium when present in adequate concentration under growth conditions. the dose response is sigmoidal with a threshold or quasi-threshold at concentrations below about 10 microgram/ml. frameshift mutagenesis by 8-mop in the dark is unaffected by mutations at the uvra or uvrb genes, in contrast to base pair substitution mutagenesis by 8-mop plus near uv light. reca (but ... | 1977 | 333279 |
| mutagenicity of isomeric diol-epoxides of benzo[a]pyrene and benz[a]anthracene in s. typhimurium ta98 and ta100 and in v79 chinese hamster cells. | pairs of isomeric vicinal diol-epoxides derived from benzo[a]pyrene 7,8- and 9,10-dihydrodiols and from benz[a]anthracene 8,9-dihydrodiol were tested for their abilities to revert salmonella typhimurium strains ta98 and ta100 to histidine prototrophy and to induce the formation of 8-azaguanine- or of ouabain-resistant v79 chinese hamster cells. all six diol-epoxides were active in both bacterial strains, but 7beta,8alpha-dihydroxy-9beta,10beta-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (the syn iso ... | 1977 | 333280 |
| mutagenicity of fungal metabolites related to aflatoxin biosynthesis. | fungal metabolites identified as the intermediates in aflatoxin biosynthetic pathway were screened for their mutagenic activity to salmonella typhimurium ta98. norsolorinic acid, averufin, and versiconal acetate were found to possess questionable mutagenic activity, but versicolorin a, and sterigmatocystin were significant mutagens relative to aflatoxin b1. the mutagenic activity appears to be related to the bisfuran and not the anthraquinone moiety of the molecule, even though the latter is a k ... | 1977 | 333283 |