| herpes simplex virus latent rna (lat) is not required for latent infection in the mouse. | during latent infection by herpes simplex virus (hsv), an abundant latency-associated transcript (lat) that is antisense to a predominant viral alpha gene (icp0) is found localized in the nucleus of sensory neurons. we disrupted both copies of the lat gene in the hsv-1 genome by insertion of the escherichia coli lacz gene under lat promoter control. the resulting recombinant virus, rh142, does not express any detectable lat in either latently or productively infected cells, although beta-galacto ... | 1989 | 2552449 |
| a ubiquitin carrier protein from wheat germ is structurally and functionally similar to the yeast dna repair enzyme encoded by rad6. | the rad6 gene from the yeast saccharomyces cerevisiae encodes a ubiquitin carrier protein (e2) required for a variety of cellular processes including dna repair, induced mutagenesis, and sporulation. here we identify an e2 from a higher plant, wheat, that is similar to rad6 with respect to both structure and in vitro substrate specificity. the protein was purified from wheat germ by a combination of ubiquitin covalent affinity chromatography and anion-exchange hplc and has an apparent molecular ... | 1989 | 2557633 |
| [genetic and biochemical studies on the mechanism of mammalian chromosome replication]. | it has been clarified that basic mechanism of deoxyribonucleic acid (dna) replication is conserved from bacteria to higher cells. what distinguishes prokaryotic and eukaryotic modes of dna replication most clearly is that bacterial chromosomes form a single replicon copied from a single initiation point and eukaryotic chromosomes consist of multiple replicons that initiate at multiple points. thus, eukaryotes have to coordinate orderly replication of the genome. in order to understand this compl ... | 1989 | 2559187 |
| immunoenzymatic analysis by monoclonal antibodies of bacterial lipopolysaccharides after transfer to nitrocellulose. | a rapid, sensitive immunoenzymatic technique for the analysis of lipopolysaccharide (lps) from gram-negative bacteria using monoclonal antibodies is described. after separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the lps was either stained with silver or electrophoretically transferred to nitrocellulose. after reaction with anti-lps monoclonal antibodies, the transferred antigens were visualized by reaction with alkaline-phosphatase-labelled anti-mouse antibodies and a ... | 1985 | 2579158 |
| [detection of cellular dna strand breaks induced by antitumor drug and heat using in situ nick translation]. | cellular dna strand break induced by an alkylating agent: carboquone (cq), and heat (43 degrees c) was detected in hela cells in vitro and mouse sarcoma-180 cells in vivo. the break sites in the dna were translated artificially in the presence of escherichia coli dna polymerase i and [3h]-labeled dttp and sites in the dna were visualized by autoradiographic observation of grains in the nuclei. these breaks increased in a dose and time dependent manner, compared to findings in the control cells. ... | 1989 | 2586469 |
| endotoxic activity and enterotoxigenicity of human strains of campylobacter jejuni isolated from patients in a nigerian hospital. | limulus gelation assay and dermal schwartzman reaction provided a sensitive and reproducible means of testing the endotoxic activity of hospital strains of campylobacter jejuni in lagos, nigeria. all the 22 isolates of campylobacter jejuni tested for the limulus gelation assay were positive for the production of endotoxin. furthermore, the campylobacter suspensions caused a positive dermal schwartzman reaction in rabbits. the area of skin reaction was less extensive than that produced by escheri ... | 1989 | 2632005 |
| high level expression in escherichia coli of the dna-binding domain of the glucocorticoid receptor in a functional form utilizing domain-specific cleavage of a fusion protein. | a fragment comprising the dna-binding domain of the human glucocorticoid receptor has been expressed in a functional form in escherichia coli as a fusion protein with protein a from staphylococcus aureus. the dna-binding domain was purified to apparent homogeneity by affinity chromatography on igg-sepharose and dna-cellulose, a purification scheme which does not involve denaturation of the protein at any step. the dna-binding domain was separated from the protein a part of the fusion protein by ... | 1989 | 2642905 |
| fatty acid interactions with rat intestinal and liver fatty acid-binding proteins expressed in escherichia coli. a comparative 13c nmr study. | enterocytes in the small intestinal mucosa contain abundant quantities of two homologous cytosolic proteins known as intestinal and liver fatty acid-binding proteins (i- and l-fabp, respectively). to elucidate structure-function relationships for these proteins, the interactions between 13c-enriched palmitate and oleate and escherichia coli-expressed rat i- and l-fabp were systematically compared using 13c nmr spectroscopy. nmr spectra of samples containing fatty acids (fa) and i-fabp at differe ... | 1989 | 2644270 |
| in vitro use of monoclonal antibodies in escherichia coli s-30 extracts to determine the rna polymerase sigma subunit required by a promoter. | rna polymerase requires one of a family of sigma subunits for specific promoter recognition and initiation. we have developed an in vitro method to define the rna polymerase sigma subunit required by a promoter. mouse monoclonal antibodies specific for either escherichia coli sigma 70 or sigma 32 or salmonella typhimurium sigma 54 were added to an e. coli coupled transcription-translation s-30 extract programed with a dna template containing the promoter of interest. using the representative lac ... | 1989 | 2645278 |
| an essential yeast protein, encoded by duplicated genes tif1 and tif2 and homologous to the mammalian translation initiation factor eif-4a, can suppress a mitochondrial missense mutation. | we describe the isolation and characterization of two previously undescribed genes, tif1 and tif2, from saccharomyces cerevisiae. the protein-encoding sequences of the two genes are highly conserved, resulting in two completely identical proteins, whereas the flanking regions show no obvious homology. the two yeast proteins are highly similar to the translation initiation factor eif-4a from mouse. elevated gene dosage of tif1 or tif2 results in the suppression of a missense mutation in the mitoc ... | 1989 | 2648398 |
| inhibitory activity of cranberry juice on adherence of type 1 and type p fimbriated escherichia coli to eucaryotic cells. | inhibition of bacterial adherence to bladder cells has been assumed to account for the beneficial action ascribed to cranberry juice and cranberry juice cocktail in the prevention of urinary tract infections (a. e. sobota, j. urol. 131:1013-1016, 1984). we have examined the effect of the cocktail and juice on the adherence of escherichia coli expressing surface lectins of defined sugar specificity to yeasts, tissue culture cells, erythrocytes, and mouse peritoneal macrophages. cranberry juice co ... | 1989 | 2653218 |
| an enzyme immunoassay for human lymphotoxin. | a highly sensitive and specific enzyme immunoassay (eia) for human lymphotoxin (hlt) has been developed. the assay is based upon a sandwich system employing two kinds of anti-hlt antibodies with neutralizing activity. one of them was mouse monoclonal antibody raised against escherichia coli-derived recombinant hlt with a deletion of 20 amino-terminal amino acids and used as labelled antibody. the other was rabbit antibody raised against the carboxyl-terminal portion of hlt and used as solid-phas ... | 1989 | 2654187 |
| the influence of stress and cheese-whey on intestinal parameters in mice. | in a mouse model the effects of environmental stress on gastrointestinal parameters and the effects of cheese-whey on the changes induced by stress were studied. mice were subjected to overcrowding, lack of bedding, overcrowding together with lack of bedding, continuous light, and housing at 30 degrees c. the influence of stress on relative caecal weight, faecal enterobacteriaceae, colonisation resistance (cr), filamentous segmented bacteria in the small intestine, fusiform bacteria in the faece ... | 1989 | 2655262 |
| characterization of a large gene family in schistosoma japonicum that encodes an immunogenic miracidial antigen. | three of eleven clones isolated from a genomic expression library of schistosoma japonicum dna using chronically infected human sera also react with chronically infected mouse sera. characterization of these three clones showed that they contain different members of the same gene family. one clone contains two members of the gene family approximately 2 kb apart and in opposite orientation to each other. dna sequence homologies between pairs of genes range from 98% to 99.5%. southern hybridizatio ... | 1989 | 2657419 |
| immunoserological comparison of 104-kilodalton proteins associated with hemolysis and cytolysis in actinobacillus pleuropneumoniae, actinobacillus suis, pasteurella haemolytica, and escherichia coli. | a homologous polyclonal antibody was produced in a rabbit to the 104-kilodalton (kda) protein hemolysin of actinobacillus pleuropneumoniae serotype 1 strain cm-5. in immunoblots, this antibody recognized a similar 104-kda protein produced in culture supernatants by a. pleuropneumoniae serotypes 1 to 12 and taxon "minor group" in addition to pasteurella haemolytica, actinobacillus suis, and alpha-hemolysin-producing escherichia coli (but only weakly in the latter two organisms). these results wer ... | 1989 | 2674017 |
| cytovillin, a microvillar mr 75,000 protein. cdna sequence, prokaryotic expression, and chromosomal localization. | cytovillin is a microvillar cytoplasmic peripheral membrane protein, with prominent expression in vivo in placental syncytiotrophoblasts and certain human tumors. cytovillin cdna was cloned from a human placental lambda gt11 library using affinity purified antibodies. the identity of cytovillin cdna clones was confirmed by expression of cytovillin in escherichia coli and using antibodies raised against the expressed fusion protein in comparison with antibodies against cytovillin purified from cu ... | 1989 | 2674140 |
| potencies of ceftriaxone and cefotaxime in a single chamber pharmacokinetic system simulating their in vivo half-lives. | ceftriaxone and cefotaxime are third-generation cephalosporins with similar in vitro potencies and spectra. however, previous studies have shown that ceftriaxone had superior in vivo activity (mouse pd50 values greater than or equal to 2-fold lower) compared to cefotaxime in 23 of 46 tested enterobacteriaceae. this superior activity was thought to be due to ceftriaxone's 5- to 8-fold longer half-life. the relationship between half-life (ceftriax-one 6 h, cefotaxime 1 h) and potency was examined ... | 1989 | 2676404 |
| biosynthesis and secretion of pullulanase, a lipoprotein from klebsiella aerogenes. | we constructed, by site-directed mutagenesis, a mutant pullulanase gene in which the cysteine residue in a pentapeptide sequence, leu16-leu-ser-gly-cys20 within the nh2-terminal region of pullulanase from klebsiella aerogenes, is replaced by serine (ser20). the modification, processing, and subcellular localization of the mutant pullulanase were studied. labeling studies with [3h]palmitate and immunoprecipitation with mouse antiserum raised against pullulanase showed that the wild form of both t ... | 1989 | 2677008 |
| monoclonal antibodies for affinity purification of il-6/ifn- beta 2 and for neutralization of hgf activity. | two types of recombinant human il-6 (ril-6) were used for the development of specific monoclonal antibodies. the first was produced in e. coli and used for immunization, the second was produced in chinese hamster ovary cells (cho) and used for screening. the complete translated sequence of the cdna coding for human il-6 was fused, in phase, to protein-a and the hybrid gene was fused to the strong lambda pr promoter. this protein was purified from bacterial extracts by chromatography on rabbit ig ... | 1989 | 2680901 |
| cloning and expression of the pasteurella multocida toxin gene, toxa, in escherichia coli. | a chromosomal dna library of a toxigenic type d strain of pasteurella multocida subsp. multocida was established in escherichia coli. from this library two clones, spe308 and spe312, were identified by using a monoclonal antibody against the osteoclast-stimulating p. multocida toxin (pmt). extracts of these clones showed cytopathic activity identical to that of extracts of toxigenic p. multocida. the recombinant plasmids, pspe308 and pspe312, directed the synthesis of a protein with an apparent ... | 1989 | 2680987 |
| cloning of murine adipocyte lipid binding protein in escherichia coli. its purification, ligand binding properties, and phosphorylation by the adipocyte insulin receptor. | the murine adipocyte lipid binding protein (albp) has been cloned into escherichia coli, purified from expressing cultures, and its ligand binding and phosphorylation properties studied. in the cloning strategy, the recombinant, pt7-5 ralbp, was transformed into e. coli strain k38 harboring plasmid pgp1-2 which directs the synthesis of t7 rna polymerase. upon shifting the temperature from 30 to 42 degrees c to induce t7 rna polymerase expression, the 14.6-kda recombinant albp (ralbp) was express ... | 1989 | 2684957 |
| effect of endotoxin on colonisation of campylobacter jejuni in infant mice. | an infant mouse model has been used to investigate the colonisation of the intestine by campylobacter jejuni and the effect of endotoxin (escherichia coli o26: b6) on the initial stage of this process. endotoxin injected 1 or 16 h before the bacterial challenge had no effect on the growth of campylobacters but endotoxin injected 4 to 10 h before the bacterial challenge caused a bacteriostatic effect on the growth of campylobacters which lasted for one day. the bacteriostatic effect was evident b ... | 1989 | 2685315 |
| a sensitive enzyme immunoassay for human epidermal growth factor. determination of hegf in human serum and urine and pharmacokinetics in mouse. | a sensitive enzyme immunoassay for human epidermal growth factor (hegf) is described. the anti-hegf antibody was prepared by immunizing rabbits with hegf, which was synthesized by escherichia coli using the genetic engineering technique. the present assay system was based on the sandwiching of an antigen between anti-hegf f(ab')2 precoated on a 96-well polystyrene plate and beta-d-galactosidase-labeled anti-hegf fab'. the range of measurable hegf by this assay was 0.1-100 pg/well. recoveries of ... | 1989 | 2687456 |
| lymphotoxin cdna clones from a htlv-i-carrying t cell line hut-102. | the conditioned medium of a htlv-i-carrying t cell line hut-102 showed cytotoxic activity against a mouse fibroblast cell line l-m. we prepared the cdna library from hut-102 poly(a)+ rna and screened it using oligonucleotide probes that correspond to the amino acid sequences conserved in tumor necrosis factor (tnf) and lymphotoxin (lt). as a result we obtained two kinds of cdna clones encoding lt in which amino acid residue 26t of mature lt is different; one is asn and another is thr. the sequen ... | 1989 | 2692660 |
| hemagglutination, hydrophobicity, enterotoxigenicity, and drug-resistance characteristics of avian escherichia coli. | a total of 35 escherichia coli isolates obtained from necropsy materials of hens with septicemia in the konya region of turkey were examined for hemagglutination (ha), cell-surface hydrophobicity, enterotoxigenicity, and drug resistance. ha tests were performed on live cultures with human (group a), bovine, avian (chicken), and guinea pig erythrocytes with and without mannose. nine ha patterns were observed. of the 35 isolates, 62.8% exhibited mannose sensitive hemagglutination (msha), 8.6% exhi ... | 1989 | 2695047 |
| interleukin-1 alpha: its possible roles in cancer therapy. | our studies on recombinant human il-1 alpha polypeptide were summarized with respect to molecular cloning, production, quantitative assay systems, antitumor activity, myelorestorative activity and augmentation of host resistance to infections. recombinant human il-1 alpha (18 kda) was produced through the expression of the cloned human il-1 alpha cdna in escherichia coli and purified to an endotoxin-free homogeneous polypeptide. the human il-1 alpha inhibited dose-dependently the growth of synge ... | 1989 | 2701648 |
| dissociation between murine spleen cell mitogenic activity of enterotoxin contaminants and anti-tumor activity of staphylococcal protein a. | soluble staphylococcal protein a (spa) in the form of high m.w. complexes with igg has been shown to significantly inhibit the growth of meth a fibrosarcomas in balb/c mice. although spa reportedly is a potent t cell mitogen that can induce immune cell proliferation and production of humoral factors with anti-tumor activity, it has been suggested that mitogenic enterotoxin contaminants might be responsible for these effects. the purpose of the present study was to investigate the nature of spa-i ... | 1989 | 2703712 |
| production of monoclonal antibodies toward bovine interferons-alpha suitable for immunopurification. | five murine hybridoma clones, producing monoclonal antibodies (mabs) to bovine interferon-alpha (boifn-alpha) were established. one of these, f12, secreted mabs giving high titers, in elisa tests, neutralizing both boifn-alpha, -alpha c, and boifn-alpha d activities, belonging to the mouse igg1 class, and having a binding affinity constant of 10(8) m-1. f12 mabs were used for immunoaffinity purification of boifn-alpha, and recombinant boifn-alpha c from escherichia coli extracts was purified to ... | 1989 | 2715671 |
| high-level expression, purification, and characterization of recombinant human tumor necrosis factor synthesized in the methylotrophic yeast pichia pastoris. | human tumor necrosis factor (tnf) alpha/cachectin was expressed in the methylotrophic yeast pichia pastoris at high levels (greater than 30% of the soluble protein) by placing the tnf cdna under the control of regulatory sequences derived from the alcohol oxidase gene. batch fermentor cultures at cell densities of 50 and 85 g dry cell weight/l contained approximately 6 x 10(10) and 10(11) units/l tnf bioactivity (6 and 10 g/l tnf), respectively. tnf productivity of 0.108 g l-1 h-1 was obtained i ... | 1989 | 2752013 |
| histamine synthesis by mouse t lymphocytes through induced histidine decarboxylase. | when spleen cells of c57bl/6 mice or mast cell-deficient w/wv mice were cultured, their histidine decarboxylase (hdc) activity increased with increases in the histamine concentration in the cells and the medium. addition of concanavalin a (con a) or escherichia coli lipopolysaccharide (lps) enhanced the increase. the removal of adherent cells reduced both the control hdc activity and the response to the mitogens. purified t lymphocytes responded to con a but not to lps. neither con a nor lps had ... | 1989 | 2784410 |
| an expression vector for high-level protein synthesis in vero cells. | we have constructed two new multi-purpose cloning vectors, pni1 and pni2, that carry the escherichia coli gene ecogpt encoding the enzyme xanthine-guanine phosphoribosyl transferase as a dominant selective marker. the ecogpt gene is under the control of either the long-terminal-repeat promoter of mouse mammary tumor virus, pni1, or the simian virus 40 early promoter, pni2. another feature of the vectors is a polylinker preceded by the human metallothionein iia promoter. we have used pni2 for the ... | 1989 | 2806920 |
| high levels of circulating neutralizing antibody in normal animals to recombinant mouse interferon-beta produced in yeast. | plasma from normal outbred swiss mice not previously given interferon (ifn) neutralized a glycosylated (high-mannose) recombinant murine ifn-beta made in yeast (rmuifn-beta y). the neutralization antibody titers were as high as 1:6,000 versus rmuifn-beta y, whereas the titers obtained with native murine ifn-beta (muifn-beta) were 100-fold less; a recombinant murine ifn-beta make in escherichia coli (rmuifn-beta ec) was not neutralized at 1:10 dilution of plasma. an elisa using rmuifn-beta y demo ... | 1989 | 2809279 |
| colonization of the streptomycin-treated mouse large intestine by a human fecal escherichia coli strain: role of adhesion to mucosal receptors. | escherichia coli f-18, a normal fecal isolate, was previously shown to be an excellent colonizer of the streptomycin-treated cd-1 mouse large intestine, whereas e. coli f-18col-, a derivative of e. coli f-18 that no longer makes the e. coli f-18 colicin, was shown to be a poor mouse colonizer. it was also shown that e. coli f-18 bound two to three times more soluble colonic mucus protein than did e. coli f-18col- and that a major receptor in cd-1 mouse colonic mucus was a 50.5-kilodalton glycopr ... | 1988 | 2833441 |
| detection of a murine coronavirus nonstructural protein encoded in a downstream open reading frame. | mouse hepatitis virus (mhv) gene 5 contains two open reading frames. we have expressed the second open reading frame of this gene (gene 5 orf 2) in an escherichia coli expression system. this system utilized a plasmid which contained the promoter and the first 36 codons of the reca gene fused in frame with the mhv gene 5 orf 2, which is fused in turn to the beta-galactosidase gene. the protein product of this gene fusion was used to raise antibody to gene 5 orf 2. the specificity of the antibody ... | 1988 | 2834866 |
| use of progress curves to estimate the co-substrate-to-substrate flow ratio of a symport mechanism. application to the isoleucine-na+ symport of mouse ascites-tumour cells and to the lactose-proton symport. | the model envisages two components in the process, whereby ht equivalents of co-substrate and st equivalents of substrate accumulate in the cellular compartment in time t. the first is the flow through the symport, n equivalents of co-substrate entering or leaving with each substrate equivalent. the second is the basal flow of co-substrate outside the symport. in certain specific circumstances n can be derived by plotting ht/t against st/t. the principal requirement is that, whereas the ratio of ... | 1988 | 2839154 |
| site-specific dna recombination in mammalian cells by the cre recombinase of bacteriophage p1. | the cre protein encoded by the coliphage p1 is a 38-kda protein that efficiently promotes both intra- and intermolecular synapsis and recombination of dna both in escherichia coli and in vitro. recombination occurs at a specific site, called lox, and does not require any other protein factors. the cre protein is shown here also to be able to cause synapsis of dna and site-specific recombination in a mammalian cell line. a stable mouse cell line was established that expresses the cre protein unde ... | 1988 | 2839833 |
| use of retroviral vectors for mapping of splice sites in cottontail rabbit papillomavirus. | cottontail rabbit papillomavirus (crpv) genomic sequences coding for virus early functions were introduced into a retroviral vector in order to produce cdnas of the viral early region. two constructs differing in the length of control sequences preceding the e6 open reading frame were transfected into psi-2 cells and the released retroviral stock was used to infect nih3t3 cells. the proviral sequences were rescued from antibiotic g418-resistant virus-infected cells after fusion with cos cells, a ... | 1988 | 2848927 |
| a new heat-labile cytolethal distending toxin (cldt) produced by escherichia coli isolates from clinical material. | a new heat-labile escherichia coli toxin cytolethal to vero, hela, hep-2 and cho cells and negative in y-1 cells has been demonstrated in culture filtrates of 43 e. coli strains associated with diarrheal disease. this new toxin was termed a cytolethal distending toxin (cldt) to reflect the progressive cell distention and cytotoxicity evidenced in all sensitive tissue cells. cldt was distinct from the classic heat-labile (lt) and heat-stable enterotoxins, verotoxins and hemolysins and was produce ... | 1988 | 2849027 |
| structure-function studies of murine epidermal growth factor: expression and site-directed mutagenesis of epidermal growth factor gene. | wild-type murine epidermal growth factor (megf) and mutants with leu47 replaced by serine and valine, respectively, have been produced by recombinant dna methodology. a synthetic gene for megf was fused to the coding sequence for the signal peptide of the outer membrane protein a (ompa) of escherichia coli in the secretion vector pin-iii-ompa3, and the recombinant plasmid was used to transform e. coli. upon induction of gene expression, megf and the mutants was expressed and secreted into the pe ... | 1988 | 2849989 |
| a mup promoter-thymidine kinase reporter gene shows relaxed tissue-specific expression and confers male sterility upon transgenic mice. | a hybrid gene was made by fusing the 2.2-kilobase 5' promoter region of a mouse group 1 major urinary protein (mup) gene to the coding region of the herpes simplex virus type 1 thymidine kinase gene (hsv tk) and introduced into the genomes of mice by microinjection. transgenic g0 males were sterile, or when fertile did not transmit the foreign gene, and the transgenic male descendants of g0 females were also sterile. seven "lines" were established by breeding from g0 females and their transgenic ... | 1988 | 2850469 |
| requirement for the simian virus 40 small tumor antigen in tumorigenesis in transgenic mice. | to examine the role of simian virus 40 (sv40) large t and small t antigens in tumorigenesis in animals, we generated transgenic mice which expressed either both the sv40 large t and small t antigens or the sv40 large t antigen alone under the control of the mouse mammary tumor virus long terminal repeat. the mouse mammary tumor virus long terminal repeat directs the expression of transgenes in ductal epithelial cells of several organs, including the mammary gland, lung, and kidney, and in lympho ... | 1988 | 2850490 |
| preferential degradation of the oxidatively modified form of glutamine synthetase by intracellular mammalian proteases. | four intracellular proteases partially purified from liver preferentially degraded the oxidatively modified (catalytically inactive) form of glutamine synthetase. one of the proteases was cathepsin d which is of lysosomal origin; the other three proteases were present in the cytosol. two of these were calcium-dependent proteases with different calcium requirements. the low-calcium-requiring type (calpain i) accounted for most of the calcium-dependent activity of both mouse and rat liver. the cal ... | 1985 | 2856920 |
| molecular basis of escherichia coli colonization of the upper urinary tract in balb/c mice. gal-gal pili immunization prevents escherichia coli pyelonephritis in the balb/c mouse model of human pyelonephritis. | most human pyelonephritis escherichia coli isolates express both mannose (ms)- and globoside (gal-gal)-binding pili. an ascending e. coli urinary tract infection model was established in the 16-wk-old female balb/c mouse to compare the pathogenic significance of ms and gal-gal pili and their efficacy as vaccines for the prevention of pyelonephritis. the distribution and density of pilus receptor compounds in urogenital tissues and as soluble compounds in urine were determined with antibodies to ... | 1985 | 2857730 |
| localization of intravenously injected lipopolysaccharide (lps) in the spleen of the mouse. an immunoperoxidase and histochemical study. | in earlier studies we investigated the in vivo effects of lipopolysaccharide (lps) on lymphoid and non-lymphoid cells in the mouse spleen. in order to find out whether lps localizes in and/or on cells that are affected by this compound, the aim of the present study was to investigate the localization of intravenously injected lps in the mouse spleen using an immunoperoxidase technique. at different time points after injection, the localization of lps is demonstrated and lps-containing cells are ... | 1985 | 2859697 |
| expression of human terminal deoxynucleotidyl transferase in escherichia coli. | a cloned dna fragment related to pt17 containing a partial cdna sequence of human terminal deoxynucleotidyl transferase was used as a probe to screen for the full length cdna sequence of the enzyme in a lambda gt11 library constructed from human lymphoblastoid km-3 cdna. a recombinant containing a 2068-base pair insert was isolated and recloned into the ecori site of the sequencing plasmic puc-8 as two subclones, pt711 and pt106. dna sequencing and hybridization studies showed that pt711 contain ... | 1985 | 2863268 |
| high-efficiency cloning of dna sequences complementary to mouse neuroblastoma polyadenylated rna. | a cdna library was efficiently synthesized from mouse neuroblastoma poly(a)+rna. several modifications of the oligo(dc)(dg) tailing procedure were used. after first strand synthesis, a datp tail was added to the 3'-end of the cdna. the second strand was primed for synthesis with oligo(dt). blunt ends were produced on the cdna by treatment with s1 nuclease. size-enriched fractions of high molecular weight dnas were obtained by passing the cdna over a sepharose cl-4b column. the optimal tailing ti ... | 1985 | 2867133 |
| potent antagonism of escherichia coli, bacteroides ovatus, fusobacterium varium, and enterococcus faecalis, alone or in combination, for enteropathogens in anaerobic continuous flow cultures. | interactions between representative strains of four predominant resident bacteria of the human colon, escherichia coli, enterococcus faecalis, bacteroides ovatus, and fusobacterium varium, and strains of seven enteropathogens, yersinia enterocolitica, shigella flexneri, salmonella typhimurium, vibrio parahaemolyticus, v. cholerae serogroup non o1, staphylococcus aureus, and clostridium perfringens, were examined in studies with an anaerobic continuous flow culture system and medium resembling th ... | 1986 | 2875188 |
| bacterial lectins, cell-cell recognition and infectious disease. | numerous bacterial strains produce surface lectins, commonly in the form of fimbriae that are filamentous assemblies of protein subunits. among the best characterized of these are the type 1 (mannose specific) fimbrial lectins of escherichia coli that consist almost exclusively of one class of subunit with a molecular mass of 17 kda. they possess an extended combining site corresponding to a trisaccharide and preferentially bind carbohydrate units of oligomannose or hybrid type. type 1 fimbriae ... | 1987 | 2885220 |
| exotoxin a of pseudomonas aeruginosa: substitution of glutamic acid 553 with aspartic acid drastically reduces toxicity and enzymatic activity. | glutamic acid 553 of pseudomonas aeruginosa exotoxin a (eta) has been identified by photoaffinity labeling as a residue within the nad binding site (s.f. carroll and r.j. collier, j. biol. chem. 262:8707-8711, 1987). to explore the function of glu-553 we used oligonucleotide-directed mutagenesis to replace this residue with asp in cloned eta and expressed the mutant gene in escherichia coli k-12. adp-ribosylation activity of asp-553 eta in cell extracts was about 1,800-fold lower and toxicity fo ... | 1987 | 2889718 |
| protective antigens against enterotoxigenic escherichia coli o101:k99,f41 in the infant mouse diarrhea model. | protective antigens present in whole cells of bovine enterotoxigenic escherichia coli strains were tested in an infant mouse diarrhea model. reduction of mortality rates of infant mice suckling vaccinated mothers was measured 1, 2, and 5 days after oral challenge with strain b41 (o101:k99,f41:h-). vaccines consisted of strains of serogroup o101, o9, o8, or o20 and of variants bearing or not bearing antigens k99 and f41. k99 and f41 expressions were checked by slide agglutination with k99 and f41 ... | 1988 | 2895746 |
| an engrailed class homeo box gene in sea urchins. | the homeo box, a conserved dna element first recognized in drosophila development-controlling genes, is present in the genomes of many higher metazoan species and provides a valuable probe for the isolation of regulatory genes from diverse phylogenetic groups. we have employed these probes to isolate and study the homeo-box genes in sea urchins. as in other species, the sea urchin homeo boxes fall into at least two classes defined by nucleotide sequence similarity to the homeo boxes of the droso ... | 1988 | 2899533 |
| macrophage-mediated n-nitrosation of thioproline and proline. | thioproline (thiazolidine-4-carboxylic acid) and proline were nitrosated by stimulated mouse macrophages in vitro. a macrophage cell line (j774.1, 1.0 x 10(6)/well, 1 ml) was incubated with escherichia coli lipopolysaccharide, interferon-gamma and thioproline (5 mm) or proline (5 mm). after 72 hr incubation at 37 degrees c, 4 microm n-nitrosothioproline was produced. the amount of n-nitrosoproline was much lower than that of n-nitrosothioproline. thioproline and proline inhibited the formation o ... | 1989 | 2930520 |
| dna polymerase alpha activity is not affected by protein kinases or alkaline phosphatase. | recent studies with crude or partially purified cell extracts have suggested that dna polymerase alpha activity may be regulated by enzymatic phosphorylation. to further investigate these findings, we have examined the effects of protein kinases and phosphatases on highly purified dna polymerase alpha from mouse cells. incubation of dna polymerase alpha with a variety of protein kinases, including protein kinase c, had no effect on polymerase activity. in addition, treatment of the polymerase wi ... | 1989 | 2930569 |
| general recombination mechanisms in extracts of meiotic cells. | reca-like proteins have been purified from somatic and meiotic cells of mouse and lily. the rec proteins have been designated "s-rec" and "m-rec" to indicate their respective tissues of origin. the two proteins differ in molecular weight and in their response to temperature, the latter being consistent with the optimal temperature for physiological function of their tissues of origin. there is a major increase in m-rec protein with the entry of cells into meiosis, the peak of activity being earl ... | 1985 | 2935376 |
| synergy of ciprofloxacin and azlocillin in vitro and in a neutropenic mouse model of infection. | combinations of ciprofloxacin with azlocillin, piperacillin and ticarcillin were tested in vitro against clinical isolates. azlocillin plus ciprofloxacin showed synergy against 30% of pseudomonas aeruginosa isolates; it was either synergistic or additive against 78% of all isolates tested even those resistant to the beta-lactam. synergism was rarely noted for klebsiella pneumoniae, escherichia coli, enterobacter spp. or branhamella spp. isolates. minimum inhibitory concentrations of ciprofloxaci ... | 1986 | 2938945 |
| induction of cellular dna synthesis by purified adenovirus e1a proteins. | the purified escherichia coli-expressed products of the human subgroup-c adenovirus e1a 13 s and 12 s mrnas are shown to induce cellular dna synthesis when introduced by microinjection into quiescent, g0-arrested mammalian cells from immortalized cell lines. the e1a proteins stimulated cellular dna synthesis in mouse swiss 3t3 cells, when microinjected either individually or in combination. a truncated e1a protein, in which 169 carboxyl terminal residues of the 289-amino acid e1a 13 s mrna produ ... | 1986 | 2940743 |
| assessment of the in vitro and in vivo activity of ciprofloxacin measured against current standards of therapy. | the bactericidal activity of ciprofloxacin in active human serum was investigated using serum-resistant escherichia coli c14 and pseudomonas aeruginosa 220 as test organisms. in 100% or 80% human serum the growth rate of e. coli c14 was lower than in broth. this also influenced the killing rate of ciprofloxacin. ciprofloxacin was more active in serum than norfloxacin or ofloxacin and killed pseudomonas aeruginosa 220 much more rapidly than azlocillin or tobramycin. rapid killing was also observe ... | 1985 | 2941263 |
| rapid isolation and characterization of hybridization selected recombinants from lambda genomic libraries. | this paper describes an efficient protocol for the screening of lambda genomic libraries, plaque and dna purification, and probe characterization by a combination of new and recently described techniques. the protocol has allowed large numbers of human subchromosome-specific probes to be rapidly generated from an embl3 library of human-mouse somatic cell hybrid dna. the protocol affords considerable savings in time and effort over previous procedures. | 1986 | 2949674 |
| divergent changes in antimicrobial activity after immunologic activation of mouse peritoneal macrophages. | to find out whether activated macrophages display a nonspecific enhancement of antibacterial activity, we determined the intracellular killing of bacteria by peritoneal macrophages from cba and c57bl/10 mice infected with bcg and challenged with mycobacterial antigens (purified protein derivative (ppd]. after in vivo phagocytosis, the rate of in vitro intracellular killing of listeria monocytogenes by bacillus calmette-guérin (bcg)-ppd-activated macrophages from cba mice increased by a factor of ... | 1987 | 2957432 |
| comparison of the orotidine 5'-monophosphate decarboxylase sequences of eight species. | predicted amino acid sequences of the enzyme orotidine 5'-phosphate decarboxylase (ec 4.1.1.23) from eight different organisms are compared. the comparisons are made on the basis of primary structural differences, primary amino acid sequence, hydropathy profiles, and secondary structure predictions. the organisms compared are mus musculus, aspergillus nidulans, neurospora crassa, kluyveromyces lactis, saccharomyces cerevisiae, schizosaccharomyces pombe, escherichia coli, and salmonella typhimuri ... | 1988 | 2974823 |
| characterization of a retrovirus shuttle vector capable of either proviral integration or extrachromosomal replication in mouse cells. | a retrovirus shuttle vector is described that contains the dominant selectable neo gene which confers resistance to kanamycin in bacteria and to the drug g418 in animal cells. the bacterial supf gene and the origins of dna replication from polyomavirus and the cole1 replicon also have been included in this vector. infection of normal rodent cells results in single-copy proviral integration, whereas infection of mouse (mop) cells expressing polyoma large t antigen results in extrachromosomal repl ... | 1985 | 2983188 |
| genes aroa and serc of salmonella typhimurium constitute an operon. | genetic analysis of aroa554::tn10 derivatives of two mouse-virulent salmonella typhimurium strains, "firn" and "wray," and of a nonreverting derivative of each constructed for use as a live vaccine, showed the site of the insertion among mapped aroa point mutants. the wray live-vaccine strain gave no aro+ recombinants in crosses with aroa point mutations to one side of the insertion, indicating a deletion from tn10 through the sites of these point mutations. the firn live-vaccine strain gave wil ... | 1985 | 2989248 |
| high spontaneous mutation frequency of bpv shuttle vector. | a recombinant shuttle vector containing the entire bovine papillomavirus (bpv) genome, sequences from pbr322, and the escherichia coli gpt gene was used to transform mouse c127 cells. plasmid extracted from the transformed mouse cells was used to transform a gpt- derivative of e. coli hb101, and the relative frequency of plasmids carrying a mutation in the gpt gene was determined. approximate mutant frequencies of 3-16 x 10(-3) were observed for plasmid molecules which had been passaged through ... | 1985 | 2994240 |
| angiotensin converting enzyme and endotoxin induced lung damage in the mouse. | acute pulmonary oedema can be induced by intraperitoneal injection of escherichia coli endotoxin in the mouse. a fall in serum angiotensin converting enzyme activity is found in mice given endotoxin and in patients with septic adult respiratory distress syndrome, and has been proposed as an indicator of lung microvascular injury. protein concentration and angiotensin converting enzyme activity in serum, lung, and bronchoalveolar lavage fluid were determined in male mice up to eight hours after i ... | 1985 | 2997946 |
| site-directed cleavage of immunoglobulin gene segments by lymphoid cell extracts. | to study the enzyme(s) involved in the site-specific recombination of immunoglobulin (ig) gene segments, we designed an assay to detect v-j joining in vitro. the dna from a hybrid phage (lambda vjck) containing the vk41 gene segment separated by a 6-kilobase spacer region from the entire j-ck sequence was incubated with lymphoid cell extracts and packaged in vitro. phages carrying genomic deletions were selected by screening for ethylenediaminetetraacetic acid resistance. although no site-specif ... | 1985 | 3000549 |
| transcription of integrated mmtv ltr dna in fibroblast clones is not associated with dna methylation but with the integration site. | by transfecting 3t3 tk- fibroblasts with a plasmid dna containing the mmtv ltr promotor and the thymidine kinase gene, we have isolated tk+ clones that contain only one copy of the recombinant dna. the newly acquired dna is integrated at different sites in each tk+ clones and can be amplified as a tandem repeat in some cases. the basal level of expression of the newly acquired ltr sequence is variable among the tk+ clones studied. among those producing detectable amounts of mmtv rna, we found th ... | 1985 | 3002496 |
| bacterially expressed antigenic peptide from foot-and-mouth disease virus capsid elicits variable immunologic responses in animals. | a fusion protein consisting of beta-galactosidase (gz) to which was attached at its n-terminus the amino acid sequence corresponding to residues 142-160 of the immunogenic protein vp1 of foot-and-mouth disease virus (fmdv) has been expressed in e. coli. a chemically synthesized section of dna corresponding to the amino acid sequence 142-160 was inserted into a vector (pxy410) designed to express fusion proteins with the carboxy terminal 1015 amino acids of gz. the hybrid protein immunopurified b ... | 1986 | 3005401 |
| analysis of cosmids using linearization by phage lambda terminase. | a group of cosmid clones was isolated from the region of the mouse t complex and analysed by a rapid restriction mapping protocol based on linearization of circular cosmid dna in vitro. a plasmid capable of producing high levels of phage lambda terminase was constructed and procedures for in vitro cleavage of cosmid dnas were optimised. after linearization, the cosmids were partially digested with restriction enzymes, and either cos end was labelled by hybridization with radioactive oligos compl ... | 1985 | 3007292 |
| isolation and characterization of cdna clones from mouse skeletal muscle actin mrna. | the sequence corresponding to approximately 98% of mouse skeletal muscle actin mrna was determined from cdna clones isolated from a library of recombinants in pbr322. one of these clones contains dna corresponding to the complete amino acid coding region and a large part of the 5' and 3' untranslated regions of the mrna. comparison of the mouse coding region (conserved at the amino acid level) and noncoding regions with the corresponding regions of the rat skeletal muscle actin gene indicates th ... | 1986 | 3013550 |
| biological activities and receptor binding of two human recombinant interferons and their hybrids. | two human recombinant lymphoblastoid interferon-alpha subtypes, lyifn-b (alpha 8) and lyifn-d (alpha 1), and 10 hybrids generated therefrom were produced in escherichia coli and purified. the antiviral and antiproliferative activities and the induction of (2'-5')oligoadenylate synthetase were compared to their receptor binding affinities. the ifn subtypes and their hybrids had similar specific antiviral activities on bovine cells. on human cells both the specific antiviral and antiproliferative ... | 1986 | 3016158 |
| introduction, rescue and expression of plasmid genes in mammalian cells and escherichia coli. | a shuttle-vector system is described for the study of mutational specificity in mammalian cells. using a plasmid (pgktk) carrying the e. coli galactokinase gene (gk) and the herpes simplex virus thymidine kinase gene (tk), we demonstrate the introduction of a foreign gene into the chromosome of a mammalian cell (tk- mouse fibroblasts) and its efficient rescue back into e. coli. this system makes use of two genes, each of which can expressed in both e. coli and mammalian cells, thereby permitting ... | 1986 | 3018556 |
| membrane-disorganizing property of polymyxin b nonapeptide. | the possibility of improving the antibacterial activities of drugs normally excluded by gram-negative bacteria with polymyxin b nonapeptide (pmbn) has been explored. in vitro, pmbn rendered clindamycin, erythromycin, novobiocin, rifampicin and vancomycin very active against a number of gram-negative enteric bacteria. the drug also sensitized the previously resistant bacterial strains to human, mouse or guinea pig serum. however, parenterally administered pmbn failed to influence bacterial growth ... | 1986 | 3019982 |
| molecular cloning and expression in escherichia coli of the lethal factor gene of bacillus anthracis. | we have cloned and expressed in escherichia coli the lethal factor (lf) gene of bacillus anthracis. at least two of the six lf recombinant plasmids produce full-length lf protein. transcription of the lf gene in e. coli appears to be under the control of its own b. anthracis promoter. recombinant lf protein produced in e. coli remains intracellular and is not secreted. however, this lf protein is biochemically active and displays the same lethal effects as lf secreted by b. anthracis in the mous ... | 1986 | 3021591 |
| comparative study of some biological activities of porins extracted from various microorganisms. | the outer membrane of gram-negative bacteria contains some major proteins, called porins, with particular chemical and physical characteristics which reflect some specialized functions peculiar to the outer membrane. in recent years the biological properties of salmonella typhimurium sh5014 porins have been the focus of our experimental studies. the aim of the present research was to make a comparative investigation of the biological activities of porins extracted from other microorganisms class ... | 1986 | 3022112 |
| cellular response to dna damage is enhanced by the pr plasmid in mouse cells and in escherichia coli. | the pr plasmid, which enhances the survival of escherichia coli c600 exposed to uv light by induction of the sos regulatory mechanism, showed the same effect when it transformed mouse lta cells (tk-, aprt-). with tn5 insertion mutagenesis which inactivates uv functions in the pr plasmid, we recognized two different regions of the plasmid, uvp1 and uvp2. these pr uvr- mutants exhibited the same effect in lta transformed cells, demonstrating that resistance to uv light, carried by the pr plasmid, ... | 1986 | 3023858 |
| insertion elements and transitions in cloned mouse mammary tumour virus dna: further delineation of the poison sequences. | the provirus of mouse mammary tumour virus (mmtv) is reputed to contain sequences within the viral gag gene that prevent or inhibit its propagation as a recombinant dna clone in escherichia coli. here we report the successful isolation of several lambda and plasmid clones comprising the 5' virus-host dna junction fragments from integrated mmtv proviruses in br6 mice. although the lambda clones appeared intact, almost all of the plasmids were found to contain the bacterial insertion sequences is1 ... | 1986 | 3024101 |
| the inducible lac operator-repressor system is functional in mammalian cells. | we have investigated the use of the escherichia coli lac operator-repressor system to regulate expression of transfected genes in mammalian cells. we show that lac repressor produced in mouse l cells by transfection of a lacl expression vector blocks transcription of an msv-cat fusion gene when the lac operator is inserted at any one of the following sites within the promoter region: between the initiation codon (atg) and the transcription start site; between the transcription start and tata box ... | 1987 | 3028641 |
| only one out of the three strong ribosomal binding sites of the early region of bacteriophage t7 exhibits high translational efficiency in fragments of about 30 base pairs. | within the early region of bacteriophage t7 three genes, 0.3, 1 and 1.3, are most efficiently expressed. they belong to the strongest initiation signals of escherichia coli. in the t7 wild-type situation the proteins are produced with a molar ratio of gene 1:1.3:0.3 protein = 1:3.9:9.7. dna fragments of about 30 base pairs comprising the ribosomal binding sites (rbs) of these genes were synthesized and cloned into derivatives of the pds1 vector ribosomal binding sites (rbs) of these genes were s ... | 1988 | 3044788 |
| two conserved tryptophan residues of tumor necrosis factor and lymphotoxin are not involved in the biological activity. | each of the two highly conserved tryptophan residues in htnf (positions 28 and 114) was converted into phenylalanine by site-directed mutagenesis and the mutant proteins were partially purified. a cytotoxicity assay on mouse l929 cells showed only a slight reduction in biological activity, strongly suggesting that neither of the two amino acids is involved in the active site. | 1988 | 3049162 |
| dna hybridization with oligodeoxyribonucleotide probes for identifying enterotoxin-producing escherichia coli. | the dna hybridization method using oligodeoxyribonucleotide probes was compared with the gm, elisa and the infant mouse assay for determining production of lt and st, respectively, by 2000 strains of escherichia coli. sensitivity and specificity by dna hybridization for lt were 98.7 and 99.8%, and for st were 78.8 and 99.6%. | 1988 | 3050453 |
| mutagenicity studies of muroctasin. | a synthetic muramyl dipeptide derivative n2-[(n-acetylmuramoyl)-l-alanyl-d-isoglutaminyl]-n6-stearoyl-l-lysine (mdp-lys(l18), muroctasin) was studied for mutagenicity using the ames method, in vitro cytogenetics and micronucleus test. mdp-lys(l18) had no mutagenic effect on s. typhimurium (ta1535, ta1537, ta1538, ta98 and ta100) or e. coli (wp2 uvra) in the reverse mutation assay. in the cytogenetic study, mdp-lys(l18) had no effect on the chromosomes of the chinese hamster cells at cytotoxic do ... | 1988 | 3056424 |
| trypanosoma brucei ornithine decarboxylase: enzyme purification, characterization, and expression in escherichia coli. | ornithine decarboxylase from the african trypanosome is an important target for antitrypanosomal chemotherapy. despite this, the enzyme had not been previously purified or extensively characterized as it is a very low level protein. in this paper we describe the purification of trypanosoma brucei brucei ornithine decarboxylase from bloodstream form trypomastigotes by 107,000-fold to a specific activity of 2.7 x 10(6) nmol co2/h/mg of protein in the parasite. t. brucei ornithine decarboxylase had ... | 1988 | 3056933 |
| an anaerobic continuous-flow culture model of interactions between intestinal microflora and candida albicans. | the finding by earlier workers that escherichia coli suppressed the growth of candida albicans in vitro or in gnotobiotic mice has led to numerous, erroneous conclusions regarding the identity of the organisms and mechanisms responsible for the suppression of candida in the gut. this is due, in part, to the fact that nearly all studies to date have not reflected interactions as they occur in the intestinal tract. this paper describes a series of experiments that establish that an anaerobic conti ... | 1988 | 3057377 |
| the c4 and c2 but not c1 components of complement are responsible for the complement activation triggered by the ra-reactive factor. | ra-reactive factors (rarf) are the name of a group of c-dependent bactericidal factors that bind specifically to ra chemotype strains of salmonella. these factors are present in the sera of a wide variety of vertebrates and have common characteristics. here we investigate the c components required for the c activation induced by mouse rarf, by using hemolysis of ra lps-coated e (elps) as a model system. it was found that c1-depleted and c1q-depleted sera were as effective as the undepleted serum ... | 1988 | 3058802 |
| [stp (the substance produced by a strain of streptococcus sp. thom-1606) as a stimulant of the nonspecific resistance of the macroorganism]. | preparation stp, a new immunostimulating agent, is a substance produced by streptococcus strain sp. thom-1606 and capable of enhancing the nonspecific activity of the body as shown in animal experiments. the optimal dose-time parameters of the administration of the immunostimulator have been established by the method of the mathematical planning of experiments. as a result, the survival of all animals used in the experiment has been achieved. mouse peritoneal macrophages have been found to form ... | 1988 | 3064516 |
| cloning and expression of the pneumococcal neuraminidase gene in escherichia coli. | a gene bank of sau3ai-generated streptococcus pneumoniae dna fragments was constructed in escherichia coli k-12 by cloning into the bamhi site of the cosmid vector phc79. one clone capable of cleaving the fluorogenic neuraminidase substrate 2'-(4-methylumbelliferyl)-alpha-d-n-acetyl-neuraminic acid was isolated. this activity was inhibited by treatment with a mouse antiserum raised against purified pneumococcal neuraminidase. the recombinant plasmid purified from this clone (designated pjcp301) ... | 1988 | 3066700 |
| heat-stable-enterotoxin-producing escherichia coli strains isolated from dogs. | five strains of hemolytic escherichia coli isolated from dogs suffering from diarrhea were shown by radioactive and enzyme-labeled oligonucleotide probes to possess genes coding for heat-stable enterotoxin (stia). four of the strains were shown by immunoassay (enzyme-linked immunosorbent assay) and bioassay (infant mouse test) to produce sti in vitro. all five strains, however, were able to induce fluid accumulation in ligated dog intestinal loops. the four sti-producing strains all possessed th ... | 1988 | 3068249 |
| the role of the trat gene of the salmonella typhimurium virulence plasmid for serum resistance and growth within liver macrophages. | the role of the trat gene of the salmonella typhimurium virulence plasmid for the serum resistance of the bacteria and their growth within mouse liver macrophages was investigated. the gene product, the trat protein, increased the serum resistance in e. coli hb101, which naturally does not carry trat. it also contributed to the serum tolerance of s. typhimurium. the capacity of an isogenic s. typhimurium tml strain triplet, differing in their ability to express trat and in the quality of the tra ... | 1988 | 3070263 |
| antibacterial effects of ticarcillin/clavulanic acid in animal models of infection. | the therapeutic effects produced by ticarcillin plus clavulanic acid were compared with those of ticarcillin and clavulanic acid separately against infections in the mouse caused by beta-lactamase-producing bacteria. the infections studied included a pneumonia model, a local tissue infection and pyelonephritis. the distribution of ticarcillin and clavulanic acid in infected animals was evaluated by measurement of the concentrations of the substances present at sites of infection. the results sho ... | 1986 | 3087934 |
| gamma interferon priming of mouse and human macrophages for induction of tumor necrosis factor production by bacterial lipopolysaccharide. | priming of macrophages from both murine and human sources by recombinant immune interferons from escherichia coli (r-ifn-gamma s) and activation by lipopolysaccharide (lps) resulted in the production of tumor necrosis factor (tnf). r-ifn-gamma alone did not induce tnf production by macrophages; for this to occur, the second signal provided by small amounts (nanograms) of lps was required. the small amounts of lps alone were insufficient to activate the macrophages for tnf production. priming by ... | 1987 | 3099049 |
| the production of tumor necrosis factor by mouse bone marrow-derived macrophages in response to bacterial lipopolysaccharide and a chemically synthesized monosaccharide precursor. | lipid x, a monosaccharide biosynthetic precursor of lipid a, has been chemically synthesized and was shown to induce bone marrow-derived macrophages to release tumor necrosis factor (tnf) in vitro. however, relatively high amounts of lipid x were necessary for induction, and the levels of tnf were much less than those induced by small amounts of lipid a itself or lps. lipid x prepared by extraction of escherichia coli mutants induced higher levels of tnf than the chemically synthesized material, ... | 1987 | 3106494 |
| importance of disulfide linkage for constructing the biologically active human interleukin-2. | recombinant human interleukin-2 (ril-2) produced in escherichia coli possesses a free thiol group at cys-125 and a disulfide linkage between cys-58 and cys-105, as in the case for natural human interleukin-2. treatment of ril-2 with 200 mm dithiothreitol resulted in the cleavage of the cys-58-cys-105 disulfide bond. the reduced form of ril-2 thus obtained retained only 10% of the in vitro biological activity of the native form, as measured by the ability to stimulate the growth of an il-2-depend ... | 1987 | 3115179 |
| the effect of endotoxin on the lipoxygenase-mediated conversion of exogenous and endogenous arachidonic acid in mouse peritoneal macrophages. | the influence of lipopolysaccharide (lps, endotoxin) or its lipid a component (bacterial and synthetic) on the synthesis of zymosan induced leukotriene c4, prostaglandin e2 and prostacyclin and on the conversion of exogenous arachidonic acid was studied in mouse peritoneal macrophages. it was found that following preincubation with lps the amount of leukotriene c4 released during phagocytosis of zymosan was substantially decreased. the levels of prostaglandin e2 and prostacyclin, however, were t ... | 1987 | 3124210 |
| interaction of ribosomal proteins l25 from yeast and el23 from e. coli with yeast 26s and mouse 28s rrna. | the interaction of ribosomal protein el23 from e. coli and l25 from yeast with yeast 26s rrna was analysed by nitrocellulose filter binding and rnase protection experiments using both intact rrna and various fragments prepared by in vitro transcription of cloned yeast rdna regions in the sp6 system. the results show that el23 efficiently and specifically interacts with the region of 26s rrna previously identified as the binding site for the yeast ribosomal protein l25. a comparison of the oligon ... | 1987 | 3126831 |
| relationship between the susceptibility of various bacteria to active oxygen species and to intracellular killing by macrophages. | the susceptibilities of six micro-organisms to active oxygen species generated in the xanthine oxidase-mediated bactericidal system were as follows: escherichia coli 81 greater than or equal to listeria monocytogenes egd greater than or equal to salmonella typhimurium hkb-1 greater than or equal to staphylococcus aureus smith much greater than mycobacterium tuberculosis h37rv approximately equal to candida albicans nih a207 (the last two organisms were essentially resistant to this system). the ... | 1987 | 3127536 |
| reduction of yellow fever virus mouse neurovirulence by immunization with a bacterially synthesized non-structural protein (ns1) fragment. | part of a yellow fever virus-specified non-structural protein (ns1) was expressed in escherichia coli as a fusion protein with beta-galactosidase. immunization of mice with this partially purified ns1-beta-galactosidase fusion protein induced yellow fever virus-specific antibodies and provided some protection against intracerebral challenge with the virus. | 1988 | 3133449 |
| dihydrofolate reductase (mouse) and beta-galactosidase (escherichia coli) can be translocated across the plasma membrane of e. coli. | hybrid genes were constructed. one, ompa153-dfr, encoded the precursor of the 325 residue escherichia coli outer membrane protein ompa up to residue 153 which was fused to the complete 186-residue dihydrofolate reductase of the mouse. the other, ompa219-lacz, coded for the same precursor up to residue 219 which was fused to 1017 cooh-terminal residues of the 1023-residue subunit of the beta-galactosidase of e. coli. full expression of the ompa153-dfr gene caused accumulation of its precursor and ... | 1988 | 3141414 |
| pseudomonas aeruginosa diaminopimelate decarboxylase: evolutionary relationship with other amino acid decarboxylases. | the lysa gene encodes meso-diaminopimelate (dap) decarboxylase (e.c.4.1.1.20), the last enzyme of the lysine biosynthetic pathway in bacteria. we have determined the nucleotide sequence of the lysa gene from pseudomonas aeruginosa. comparison of the deduced amino acid sequence of the lysa gene product revealed extensive similarity with the sequences of the functionally equivalent enzymes from escherichia coli and corynebacterium glutamicum. even though both p. aeruginosa and e. coli are gram-neg ... | 1988 | 3143046 |
| nucleotide sequence of chicken myb proto-oncogene promoter region: detection of an evolutionarily conserved element. | the nucleotide sequence of the chicken myb proto-oncogene putative promoter region was determined and compared with the corresponding sequence of the mouse c-myb gene (1). 118 bp upstream from the initiation codon suggested by gerondakis and bishop (2) for the chicken c-myb protein, a 124-bp-long conserved element was found (92% identity in chicken and mouse sequences). sequences homologous to this element were detected on southern blots of restricted genomic dnas from mouse, man, lizard, frog, ... | 1988 | 3145493 |
| purification and some properties of shiga-like toxin from escherichia coli o157:h7 that is immunologically identical to shiga toxin. | a cytotoxin to vero cells (shiga-like toxin), which was neutralized by antibody against purified shiga toxin produced by shigella dysenteriae 1, was purified from escherichia coli o157:h7, isolated from a patient with hemorrhagic colitis. the purification procedure consisted of ammonium sulfate fractionation, deae-cellulose column chromatography, chromatofocusing column chromatography and high performance liquid chromatography. about 200 micrograms of purified shiga-like toxin was obtained from ... | 1987 | 3148810 |