| the binding site of the nicotinic acetylcholine receptor in animal species resistant to alpha-bungarotoxin. | the ligand binding site of the nicotinic acetylcholine receptor (achr) is located in the alpha-subunit, within a small fragment containing the tandem cysteines at positions 192 and 193. we have been analyzing the binding site domain of achrs from several animal species exhibiting various degrees of resistance to alpha-bungarotoxin (alpha-btx). our earlier work on the snake and mongoose achr, both of which do not bind alpha-btx, suggested that amino acid substitutions at positions 187, 189, and 1 ... | 1995 | 7619817 |
| a nuclear factor (nf2d9) that binds to the male-specific p450 (cyp 2d-9) gene in mouse liver. | expression of the cyp 2d-9 (steroid 16 alpha-hydroxylase) gene in mouse liver is male specific in such mus musculus domesticus strains as fvb/n, whereas the corresponding p450 genes in the wild mouse species mus spretus are not sex specific in their expression. these parental differences in the gene expressions were independently inherited in f1 offspring from crosses of fvb/n and m. spretus. a 5' flanking sequence (-110ctc ctccctattccgggcc-92) was defined as a regulatory element (named sdi-a1) ... | 1995 | 7623810 |
| differences in kinetic properties of pure recombinant human and mouse deoxycytidine kinase. | human and mouse deoxycytidine kinase (dck) (ec 2.7.1.74) were cloned and expressed in escherichia coli. michaelis-menten kinetics were determined for the purified enzymes with 2'-deoxycytidine (dcyd), 2'-deoxyadenosine (dado), 2-chloro-2'-deoxyadenosine (cda), 2',3'-dideoxycytidine (ddcyd) and 9-beta-d-arabinofuranosylguanine (arag) as substrates and atp and utp as phosphate donors. both human and mouse dck showed highest affinity to dcyd with km values of 0.05-0.2 microm. the anti-leukaemic com ... | 1995 | 7632159 |
| mouse protection induced by pseudomonas aeruginosa pac1r and its defective mutants, salmonella minnesota re-mutant and escherichia coli o14. | pseudomonas aeruginosa pac1r and its defective mutants (acetone-killed bacteria), salmonella minnesota re mutant (acetone-killed bacteria and re-lps) and escherichia coli o14 (acetone-killed bacteria and enterobacterial common antigen, eca) were studied in a mouse active protection test. immunized mice were challenged with wild-type p. aeruginosa strains. it was established that p. aeruginosa lps-defective mutants induced cross-immunity against different fisher immunotypes of p. aeruginosa. s. m ... | 1995 | 7640675 |
| multiple bcl-2 family members demonstrate selective dimerizations with bax. | a family of bcl-2-related proteins regulates cell death and shares highly conserved bh1 and bh2 domains. bh1 and bh2 domains of bcl-2 were required for it to heterodimerize with bax and to repress apoptosis. a yeast two-hybrid assay accurately reproduced this interaction and defined a selectivity and hierarchy of further dimerizations. bax also heterodimerizes with bcl-xl, mcl-1, and a1. a gly-159-->ala substitution in bh1 of bcl-xl disrupted its heterodimerization with bax and abrogated its inh ... | 1995 | 7644501 |
| bacterial translocation-related mortality may be associated with neutrophil-mediated organ damage. | balb/c mice were transfused with .2 ml of c3h/hej mouse blood. 5 days later, the mice were gavaged with 10(10) 14c-labeled escherichia coli, and a 20% full thickness flame burn was inflicted. additional animals were treated with enisoprost (prostaglandin e1 (pge1) analog) 200 micrograms/kg/day orally for 3 days before burn. bacterial translocation was determined by both radionuclide counts (dpm) and viable colony counts 24 h post burn. neutrophil accumulation was evaluated by the measurement of ... | 1995 | 7648332 |
| structural basis for dna bending by the architectural transcription factor lef-1. | lymphoid enhancer-binding factor (lef-1) and the closely related t-cell factor 1 (tcf-1) are sequence-specific and cell-type-specific dna-binding proteins that play important regulatory roles in organogenesis and thymocyte differentiation. lef-1 participates in regulation of the enhancer associated with the t cell receptor (tcr)-alpha gene by inducing a sharp bend in the dna and facilitating interactions between ets-1, pebp2-alpha, and atf/creb, transcription factors bound at sites flanking the ... | 1995 | 7651541 |
| critical re-examination of the distribution of aromatase-immunoreactive cells in the quail forebrain using antibodies raised against human placental aromatase and against the recombinant quail, mouse or human enzyme. | mouse and quail aromatase cdnas were isolated from libraries of mouse ovary and quail brain by using a human aromatase cdna fragment (ha-24) as a probe. these three cdnas were inserted into plasmid vectors and expressed in escherichia coli. antisera against these purified recombinant proteins were raised in rabbit and purified by ammonium sulfate fractionation and affinity chromatography. the three antibodies directed against recombinant human, mouse and quail proteins were used to visualize aro ... | 1995 | 7669272 |
| use of endotoxin as a positive (toxic) control in the mouse embryo assay. | the mouse embryo assay (mea) is used to test media used for in vitro fertilization (ivf). negative controls usually consist of previously tested media known to support growth of embryos to the blastocyst stage by 72 h. often, no concurrent positive (toxic) controls are reported. thus, any unusually hardy cohort of embryos may go undetected. endotoxin was tested for its suitability as a positive control in the mea. | 1995 | 7670274 |
| epitope mapping and accessibility of immunodominant regions of yeast plasma membrane h(+)-atpase. | immunodominant regions of yeast plasma membrane h(+)-atpase have been mapped by two different approaches. a rabbit polyclonal antibody was used to screen a library of random fragments of the atpase gene in a bacterial expression plasmid. in addition, the epitopes recognized by a panel of mouse monoclonal antibodies against the atpase were mapped by reactions with defined fragments of the enzyme expressed in escherichia coli. both methodologies indicated that two regions within the amino-terminal ... | 1993 | 7681777 |
| assembly of gabaa receptor subunits: analysis of transient single-cell expression utilizing a fluorescent substrate/marker gene technique. | gabaa receptor channels (gabars) composed of varying combinations of alpha 1, beta 1, and gamma 2s subunits were transiently expressed in mammalian cell lines. the whole-cell patch-clamp recording technique was used to determine which combinations of gabar subunits produced functional receptor channels and whether assembly of gabar subunits into receptor channels followed a random or preferred sequence. to identify rapidly cells expressing gabars, mammalian cell lines were cotransfected with com ... | 1993 | 7681869 |
| cdna for r-cognin: homology with a multifunctional protein. | retina cognin (r-cognin) is a developmentally regulated 50-kda protein that was isolated from chicken embryo retina cell membranes. it mediates the adhesion and reaggregation in vitro of retina cells from chicken and mouse embryos, but not of cells from other tissues, and may be involved in neuronal differentiation. we report here the cloning of a cdna for r-cognin. a chicken embryo retina cdna library was constructed in lambda gt11 vector and was screened with polyclonal r-cognin antiserum, yie ... | 1993 | 7681992 |
| translational repression of endogenous thymidine kinase mrna in differentiating and arresting mouse cells. | we observed that decline of thymidine kinase (tk) enzyme activity was severalfold faster than the decay of full length tk mrna during growth arrest of 3t6 mouse fibroblasts or during differentiation of myoblasts (c2cl12) or f9 embryonal carcinoma cells. in order to study the molecular mechanism of this disparate behavior, a polyclonal antiserum against mouse tk was raised in rabbit. high level expression of mouse tk polypeptide in escherichia coli was achieved with a t7 rna polymerase-directed e ... | 1993 | 7684382 |
| differences in cytokine response and induction of nitric oxide synthase in endotoxin-resistant and endotoxin-sensitive mice after intravenous gram-negative infection. | previous reports have suggested that the endotoxin-resistant c3h/hej strain of mouse is more susceptible to infection than is the endotoxin-sensitive parent strain, c3h/hen, although they have never been compared in an i.v. model of sepsis. we therefore have used these mouse strains in an i.v. model of gram-negative sepsis to compare their sensitivities to infection, their cytokine responses, and the levels of induction of the enzyme nitric oxide synthase assayed in their livers. by using i.v. i ... | 1993 | 7684416 |
| biological activity of recombinant human myelin basic protein. | using an inducible expression vector in escherichia coli, we have expressed, purified, and biologically characterized recombinant human myelin basic protein (r-mbp). the recombinant protein binds in cation-exchange chromatography with similar affinity to purified, human mbp, and elutes as a single, 18.5-kda species as judged by sds-page. the recombinant protein exhibits similar conformation to native mbp, as demonstrated by elisa reactivity with a panel of six monoclonal antibodies directed agai ... | 1993 | 7685037 |
| rnase mrp and rnase p share a common substrate. | rnase mrp is a site-specific ribonucleoprotein endoribonuclease that processes rna from the mammalian mitochondrial displacement loop containing region. rnase p is a site-specific ribonucleoprotein endoribonuclease that processes pre-trnas to generate their mature 5'-ends. a similar structure for the rnase p and rnase mrp rnas and a common cleavage mechanism for rnase mrp and rnase p enzymes have been proposed. experiments with protein synthesis antibiotics have shown that both rnase mrp and rna ... | 1993 | 7688115 |
| evidence by site-directed mutagenesis supports long-range electron transfer in mouse ribonucleotide reductase. | mammalian ribonucleotide reductase consists of two nonidentical subunits, proteins r1 and r2, each inactive alone. the r1 protein binds the ribonucleotide substrates while the r2 protein contains a binuclear iron center and a tyrosyl free radical, essential for activity. the crystal structures of the corresponding escherichia coli proteins suggest that the distance from the active site in r1 to the tyrosyl radical buried in r2 is about 35 a. therefore, an electron pathway was suggested between t ... | 1995 | 7703240 |
| cloning, expression and tissue distribution of mouse tetrameric carbonyl reductase. identity with an adipocyte 27-kda protein. | we previously cloned a cdna for pig lung tetrameric carbonyl reductase which shows significant similarity to a putative 27-kda protein predicted from the cdna for murine adipocyte rna which had been increased in its differentiation [nakanishi, m., deyashiki, y., nakayama, t., sato, k. & hara, a. (1993) biochem. biophys. res. commun. 194, 1311-1316]. in this investigation, we isolated and sequenced a full-length cdna for the tetrameric enzyme from a mouse lung cdna library. it consisted of 984 bp ... | 1995 | 7705352 |
| high level expression and refolding of mouse interleukin 4 synthesized in escherichia coli. | mouse interleukin 4 is a 20-kda glycoprotein, synthesized by activated t lymphocytes and mast cells, which regulates the growth and/or differentiation of a broad spectrum of target cells of the immune system, including b and t lymphocytes, macrophages, and hematopoietic progenitor cells. using an inducible reca promoter and the g10-l ribosome-binding site, recombinant non-glycosylated interleukin 4 (il-4) was expressed as 17% of total cellular protein in escherichia coli inclusion bodies, as a r ... | 1995 | 7706290 |
| efficient in vivo transduction of the neonatal mouse liver with pseudotyped retroviral vectors. | ideal methods for human gene therapy will eventually include direct gene transfer to defective tissues in a patient in vivo. toward that goal, we have used high titer, pseudotyped retroviral vectors expressing genes for the escherichia coli beta-galactosidase (lacz) or hepatitis b virus surface antigen (hbsag) to infect mouse liver by in vivo direct injection into the liver parenchyma. we have found that a single percutaneous injection of small volumes of vectors into the newborn mouse liver lea ... | 1995 | 7719930 |
| role of leux in escherichia coli colonization of the streptomycin-treated mouse large intestine. | escherichia coli f-18, a normal human fecal isolate, is an excellent colonizer of the streptomycin-treated mouse large intestine. e. coli f-18 col-, a derivative of e. coli f-18 that no longer makes the e. coli f-18 colicin, colonizes the mouse large intestine as well as e. coli f-18 when fed alone, but is eliminated when fed together with e. coli f-18. recently, a random bank of e. coli f-18 dna was transformed into e. coli f-18 col-, the resultant population was fed to streptomycin-treated mic ... | 1994 | 7723657 |
| characterization of mouse and human gtp cyclohydrolase i genes. mutations in patients with gtp cyclohydrolase i deficiency. | gtp cyclohydrolase i is the first and rate-limiting enzyme for the biosynthesis of tetrahydrobiopterin in mammals. previously, we reported three species of human gtp cyclohydrolase i cdna in a human liver cdna library (togari, a., ichinose, h., matsumoto, s., fujita, k., and nagatsu, t. (1992) biochem. biophys. res. commun. 187, 359-365). furthermore, very recently, we found that the gtp cyclohydrolase i gene is causative for hereditary progressive dystonia with marked diurnal fluctuation, also ... | 1995 | 7730309 |
| molecular cloning and expression of mouse mg(2+)-dependent protein phosphatase beta-4 (type 2c beta-4). | a full-length complementary dna (cdna) clone (ptk-3) encoding an isoform of mg(2+)-dependent protein phosphatase beta (mpp beta-4) was isolated for the first time from a mouse melanocyte cdna library. it was strongly suggested that the mrna corresponding to the ptk-3 insert was a splicing variant of a single pre-mrna that also encodes mpp beta-1 and -2 (t. terasawa, t. kobayashi, t. murakami, m. ohnishi, s. kato, o. tanaka, h. kondo, h. yamamoto, t. takeuchi, and s. tamura, 1993, arch. biochem. ... | 1995 | 7733667 |
| nk-lysin, a novel effector peptide of cytotoxic t and nk cells. structure and cdna cloning of the porcine form, induction by interleukin 2, antibacterial and antitumour activity. | a 78 residue antimicrobial, basic peptide, nk-lysin, with three intrachain disulfide bonds was purified from pig small intestine and characterized. a corresponding clone was isolated from a porcine bone marrow cdna library. the 780 bp dna sequence had a reading frame of 129 amino acids which corresponded to nk-lysin. the clone was used to show that stimulation with human interleukin-2 induced synthesis of nk-lysin-specific mrna in a lymphocyte fraction enriched for t and nk cells. lower levels o ... | 1995 | 7737114 |
| cloning and expression of a murine fascin homolog from mouse brain. | the fascins are a widely distributed family of proteins that organize filamentous actin into bundles. we have cloned, sequenced, and expressed the murine homolog. fascin is most abundant in brain and is found in other tissues including uterus and spleen. the deduced open reading frame encodes a protein of 493 amino acids with a molecular mass of 54,412 da. previous solubility problems with bacterially expressed fascins were overcome by producing the mouse protein as a fusion with escherichia col ... | 1995 | 7738015 |
| apparent inhibition of superoxide dismutase activity in vitro by diesel exhaust particles. | the inhibitory effects of diesel exhaust particles (dep) on superoxide dismutase (sod) activity were examined in vitro because intratracheal administration of dep to mice resulted in a suppression of the pulmonary enzyme activity (sagai et al., free radic. biol. med. 14:37-47; 1993). superoxide production, based on the reduction of cytochrome c, was suppressed considerably by the soluble fraction of mouse lung and by purified sod from bovine erythrocytes, but the suppression was drastically dimi ... | 1995 | 7744321 |
| serotonin upregulates mitogen-stimulated b lymphocyte proliferation through 5-ht1a receptors. | serotonin is a well-known neurotransmitter and neuroimmunomodulator which has been reported to modulate t cell and nk cell proliferation. in this study we investigated whether serotonin could regulate mitogen-stimulated proliferation of the mature b lymphocyte. mouse and rat spleen cells were cultured with serotonin in the presence or absence of a combination of escherichia coli lipopolysaccharide and dextran sulfate, and proliferation was assessed by [3h]thymidine uptake or propidium iodide sta ... | 1995 | 7758118 |
| a mouse ig kappa domain of very unusual framework structure loses function when converted to the consensus. | antibody gene sequences, particularly those of kappa light chains, are very well conserved in the framework region, and the variability is concentrated in the complementarity-determining regions (cdr). we now found that the murine antibody 93-6 (djavadi-ohaniance, l., friguet, b., and goldberg, m. (1984) biochemistry 23, 97-104) whose fab fragment binds the beta-subunit of escherichia coli tryptophan synthase with high affinity (kd of 6.7.10(-9) m) has a highly unusual kappa light chain framewor ... | 1995 | 7759486 |
| absence of persistence and transfer of genetic material by recombinant escherichia coli in conventional, antibiotic-treated mice. | strain bst-1 is a derivative of escherichia coli k-12 that carries a plasmid designated pura-4 and is the expression system used by the upjohn company in the production of recombinant bovine somatotropin (rbst). this plasmid also encodes an ampicillin resistance gene. the plasmidless carrier strain, bst-1c, contains a gene for tetracycline resistance which is provided by the chromosomal insertion of the transposon tn10. therefore, bst-1 is resistant to ampicillin and tetracycline, while bst-1c i ... | 1993 | 7763898 |
| safety assessment of the neomycin phosphotransferase ii (nptii) protein. | two approaches were used to assess the safety of the nptii protein for human consumption using purified e. coli produced nptii protein that was shown to be chemically and functionally equivalent to the nptii protein produced in genetically engineered cotton seed, potato tubers and tomato fruit. the nptii protein was shown, as expected, to degrade rapidly under simulated mammalian digestive conditions. an acute mouse gavage study confirmed that the nptii protein caused no deleterious effects when ... | 1993 | 7764244 |
| high-level expression of mycoplasma arginine deiminase in escherichia coli and its efficient renaturation as an anti-tumor enzyme. | the arginine deiminase (ad) gene was cloned from mycoplasma arginini and expressed in the cytosol of escherichia coli as inclusion bodies with an expression level of at least 20% of the total bacterial proteins. the inclusion bodies were solubilized with 6 m guanidine hydrochloride (gdn-hcl) under reducing conditions, in order to avoid incorrect disulfide-bond formation of the recombinant (r-) ad molecules, and renaturation was performed under various refolding conditions. the optimum renaturati ... | 1994 | 7765234 |
| streptococcal protein mag--a protein with broad albumin binding specificity. | protein mag is a cell surface protein from streptococcus dysgalactiae which binds alpha 2-macroglobulin (alpha 2m), serum albumin and immunoglobulin g (igg). in this work protein mag was expressed in escherichia coli, purified and analysed for its albumin-binding specificity. the binding of protein mag to serum albumins of different species origin was studied in a dot-blot assay and compared with the binding of streptococcal protein g, so far the best studied bacterial albumin receptor. the albu ... | 1995 | 7766685 |
| functional analysis of the cell-specific enhancer in the human proopiomelanocortin gene by beta-galactosidase histochemical staining. | nucleotide sequences responsible for the cell-specific expression of the human proopiomelanocortin (pomc) gene were analyzed by histochemical staining of beta-galactosidase in culture cells transfected with chimeric genes containing the 5'-flanking regions of the human pomc gene fused to the escherichia coli lacz gene. the chimeric genes were stably introduced into various culture cells, including att-20 cells, which express the endogenous mouse pomc gene. whereas the control gene containing the ... | 1994 | 7772256 |
| mouse macrophage metalloelastase expressed in bacteria absolutely requires zinc for activity. | mouse macrophage metalloelastase was expressed in escherichia coli. this recombinant enzyme (rmme) was present in the inclusion bodies that were solubilized in 7 m guanidine hcl. after removal of guanidine hcl, rmme was purified with a q-sepharose column. degradation of [3h]elastin by rmme absolutely required ca2+; the optimal ca2+ concentration was 5 mm. nacl stimulated the enzyme activity; maximal stimulation was obtained at 400 mm. the rmme activity was inhibited by metalloprotease inhibitors ... | 1995 | 7775392 |
| e-box variants direct formation of distinct complexes with the basic helix-loop-helix protein alf1. | the murine transcription factor alf1 belongs to the class of basic helix-loop-helix proteins specific for the ncagntgn-version of the e-box. binding of homodimeric alf1 to variants of this motif was studied by a combination of binding site selection technology and dna modification interference analysis. the results showed that substitutions at the non-conserved positions in the e-box sequence could cause profound alterations in the patterns of specific contacts at the protein-dna interface. thus ... | 1995 | 7783212 |
| analysis of vibrio cholerae toxr function by construction of novel fusion proteins. | the toxr protein is a transmembrane protein that regulates the expression of several virulence factors of vibrio cholerae. previous analysis of fusion proteins between toxr and alkaline phosphatase (toxr-phoa) suggested that toxr was active as a dimer. in order to determine whether dimerization of the toxr periplasmic domain was essential for activity, this domain was replaced by monomeric and dimeric protein domains. surprisingly, phoa (dimeric), beta-lactamase (monomeric, toxr-bla), or the leu ... | 1995 | 7783643 |
| a point mutation in a murine immunoglobulin v-region strongly influences the antibody yield in escherichia coli. | recombinant dna technology has made it possible to produce specific fab and scfv antibody (ab) fragments in prokaryotic host cells. using vectors designed for periplasmic expression of encoded ab fragments, we have been studying how the sequence and genetic localization of the light chain (l-chain) variable region gene of a mouse ab (cb-nm.1) determined the level of ab production. the variable region was shown to belong to the v kappa v family and contained a previously unreported ile72. nine di ... | 1995 | 7789811 |
| differential antibiotic-induced release of endotoxin from gram-negative bacteria. | treatment of log phase cultures of escherichia coli with cell wall active antibiotics results in increased exposure of immunologically reactive lipid a epitopes of lipopolysaccharide (lps) and release of soluble lps into culture supernatants. comparison of the efficacy of two cell wall active antibiotics, ceftazidime, a penicillin-binding protein 3 selective antibiotic, and imipenem, a penicillin-binding protein 2 selective antibiotic, for their relative efficacy in mediating lps release indicat ... | 1994 | 7821304 |
| fine mechanisms of ectromelia virus thymidine kinase-negative mutants avirulence. | three independently selected spontaneous thymidine kinase-negative mutants (tk-phenotype) and a recombinant with escherichia coli beta-galactosidase gene (lacz+ phenotype) inserted in the viral thymidine kinase gene (tk) were derived from a plaque-cloned isolate of k-1 ectromelia virus strain (tk+ phenotype). dramatically decreased virulence of tk- variants was observed for all routes of mouse inoculation. the kinetics of tk+ and tk- variants in various target organs indicated a significant decr ... | 1994 | 7831964 |
| a group of novel glutathione s-transferase isozymes showing high activity towards 4-hydroxy-2-nonenal are present in bovine ocular tissues. | recently, a mouse glutathione s-transferase (gst) isozyme, mgsta4-4, which belongs to a distinct group of gsts has been characterized in our laboratory. during the present studies, western blot analyses of bovine ocular tissues using the antibodies raised against the recombinant mgsta4-4 obtained by expression in escherichia coli revealed that the orthologs of mgsta4-4 were present in cornea, retina, iris-ciliary body and sclera, but absent in lens. these novel gst isozymes of bovine ocular tiss ... | 1994 | 7835404 |
| regulation of heme biosynthesis in escherichia coli. | escherichia coli is an organism that synthesizes 5-aminolevulinate (ala), the first committed compound of the heme biosynthetic pathway, from glutamate (c-5 pathway) as opposed to glycine and succinyl coa (c-4 pathway). while regulation of the c-4 pathway is generally acknowledged to occur at the level of formation of ala, the mode of regulation of the c-5 pathway is currently unclear. here we have examined one aspect of regulation of heme synthesis in e. coli: the role of the end product, heme, ... | 1995 | 7840603 |
| purification from placenta, amino acid sequence, structure comparisons and cdna cloning of human glutaredoxin. | glutaredoxin is generally a glutathione-dependent hydrogen donor for ribonucleotide reductase and also catalyses general glutathione (gsh)-disulfide-oxidoreduction reactions in the presence of nadph and glutathione reductase. a glutaredoxin from human placenta was purified to homogeneity, as judged by sds/page and ief (12 kda). purification was monitored by the activity with hydroxyethyl disulfide as a substrate. values of pi for glutaredoxin were obtained by ief; the pi of the protein shifted f ... | 1995 | 7851394 |
| effect of pap copy number and receptor specificity on virulence of fimbriated escherichia coli in a murine urinary tract colonization model. | escherichia coli fn506 containing pap genes that encode two different p fimbriae adherence specificity types were tested for virulence in a murine urinary colonization model. strains containing adherence genes on either high copy or low copy plasmids were compared. bacteria that harbored the adherence genes on high copy plasmids colonized mouse kidneys less well than bacteria with the same adherence genes in low copy even though the high copy strains exhibited greater hemagglutination capacity. ... | 1994 | 7861959 |
| identification of a cdna for ssrp1, an hmg-box protein, by interaction with the c-myc oncoprotein in a novel bacterial expression screen. | we describe a system for screening cdna expression libraries in escherichia coli based on protein-protein interactions. the system utilizes fusion proteins containing the dna binding domain of the lambda phage cl repressor and a heterologous dimerization domain, which is the target of the screen. such chimeric proteins were functional as transcriptional repressors in e.coli; function was dependent on the presence of the heterologous dimerization domain, and function of the chimeras was disrupted ... | 1995 | 7862532 |
| [expression of hpv16e6 gene and preparation of monoclonal antibody against the expression product]. | the recombinant plasmid pas1-hpv16e6 containing the hpv16e6 gene was expressed in e. coli ar120 under nalidixic acid induction. a 19kd expression protein was isolated, purified and identified. mice were immunized with the purified e6 expression protein. a murine hybridoma, rac6, was obtained by fusing splenic cells from an immunized babl/c mouse with mouse myeloma cell line sp2/0-ag14 cells, followed by screening in hat medium, cloning and recloning in methyl cellulose. the hybridoma rac6 stably ... | 1994 | 7867098 |
| a re-appraisal of the biological activity of bacteroides lps. | lipopolysaccharides (lps) were extracted from seven bacteroides strains by three different techniques: the phenol-water (pw), phenol-chloroform-petroleum (pcp) and triton-mg2+ methods. the strains selected included two different b. fragilis strains, one of which was grown in two different media. yields varied between the strains, growth media and extraction technique, but generally the highest yield by weight was from the pcp method and the lowest from the pw method. the pw method was selected f ... | 1995 | 7869345 |
| interlaboratory comparison: liver spontaneous mutant frequency from lambda/laci transgenic mice (big blue) (ii). | spontaneous mutant frequency in livers of two transgenic mouse strains, each carrying identical lambda shuttle vectors with a laci target gene, was evaluated by two laboratories. these studies investigated variability in spontaneous mutant frequency between animals and as a function of the number of phage screened. liver dna was independently isolated from 7-11 week old c57bl/6 and b6c3f1 big blue transgenic mice. at least 500,000 phage were screened for mutation at laci for each animal using st ... | 1995 | 7870100 |
| [tissue gamma/delta t cells in experimental urinary tract infection relationship between other immuno-competent cells]. | we studied the gamma/delta t cells, which are thought to be one of the local immune-defense system, in an experimental ascending urinary tract infection model in mouse. the experimental infection was induced in the balb/c mouse by transurethral instillation of escherichia coli. gamma/delta t cells were stained immunohistochemically with abc method and the localization in the uninfected and infected murine urinary tract was determined. then, to determine the cd4 or cd8 phenotype of gamma/delta t ... | 1994 | 7876672 |
| identification of alpha-syntrophin binding to syntrophin triplet, dystrophin, and utrophin. | syntrophin represents three cytoplasmic components of the dystrophin-glycoprotein complex that links the cytoskeleton to the extracellular matrix in skeletal muscle. alpha-syntrophin has now been translated in vitro and shown to associate directly with all three components of the syntrophin triplet and with dystrophin. the in vitro translated 71-kda non-muscle dystrophin isoform, containing the cystein-rich/c-terminal domain, can also interact with the syntrophin triplet. the syntrophin binding ... | 1995 | 7890602 |
| cloning and sequencing of an intronless mouse s-adenosylmethionine decarboxylase gene coding for a functional enzyme strongly expressed in the liver. | a genomic clone for a mouse s-adenosylmethionine decarboxylase (adometdc) gene was isolated from a cosmid library. surprisingly, the gene proved to be intronless. with the exception of three base substitutions (changing 2 amino acids in the deduced protein), the 1002-nucleotide sequence of the open reading frame was identical to that of mouse adometdc cdna. moreover, the gene contained a poly(da) tract at the 3' end and was flanked by 13-base pair direct repeats. our findings suggest that this g ... | 1995 | 7890685 |
| cloning, expression, and characterization of cdnas encoding arabidopsis thaliana squalene synthase. | we have isolated and characterized two overlapping cdna clones for arabidopsis thaliana squalene synthase. their nucleotide sequences contained an open reading frame for a 410-amino acid polypeptide (calculated molecular mass, 47 kda). the deduced amino acid sequence of the arabidopsis polypeptide was significantly homologous (42-44% identical) to the sequences of known squalene synthases of several species, from yeast to man, but it was much less homologous to that of tomato phytoene synthase. ... | 1995 | 7892265 |
| d-type cyclin-binding regions of proliferating cell nuclear antigen. | proliferating cell nuclear antigen (pcna) is an auxiliary protein for dna polymerase delta and is required for both dna replication and dna repair. pcna forms complexes with d-type cyclins, candidate g1 cyclins in mammalian cells. to better understand the functions of the complexes, we examined interactions between pcna and d-type cyclins, using in vitro-translated mouse pcna and mouse cyclin d1 or d3 fused to glutathione s-transferase (gst). analysis of a set of deletion mutants of pcna reveale ... | 1994 | 7908906 |
| [study on infectious mechanism of type 1 fimbriated escherichia coli in experimental cystitis of mice]. | the course of experimental cystitis in mice with escherichia coli was studied by electron microscopy. the inoculated e. coli did not adhere to the intact bladder epithelium. however, when the mouse bladder was treated with trypsin, superficial cells were exfoliated, and the inoculated type 1 fimbriated e. coli adhered to the exposed intermediate cells and caused cystitis. the nonfimbriated e. coli showing no adherence to the superficial cells or intermediate cells and failed to cause cystitis. t ... | 1993 | 7909502 |
| membrane topology of multidrug resistance protein expressed in escherichia coli. n-terminal domain. | expression of eukaryotic polytopic membrane proteins in escherichia coli could provide an invaluable system for structure-function studies. recently, the functional expression of a mouse multidrug resistance protein (mdr1) in e. coli was described (bibi, e., gros, p., and kaback, h. r. (1993) proc. natl. acad. sci. u. s. a. 90, 9209-9213). in the present study, the phoa gene fusion approach has been utilized to determine the membrane topology of the n-terminal domain of mdr. the results support ... | 1994 | 7914193 |
| protease-catalyzed conversion of insulin-like growth factor-1 and interleukin-6 into high-molecular-mass species through the sequential action of hematopoietic surface-associated cathepsin g and gamma-glutamyl transpeptidase-related activities. | interleukin-6 (il-6) and insulin-like growth-factor-1 (igf-1) are cytokines produced by a variety of cells that act on a wide range of tissues, influencing cell growth and differentiation. purified plasma membranes from human u937 monoblastic cells produced in vitro dimeric species of il-6- and igf-1-derived peptides through the sequential actions of surface-associated enzymes cathepsin g and transpeptidase activities. cathepsin g degraded native unglycosylated il-6 and igf-1 molecules into 8-kd ... | 1994 | 7914487 |
| the human dna-binding protein, po-ga, is homologous to the large subunit of mouse replication factor c: regulation by alternate 3' processing of mrna. | we have previously cloned a human gene encoding a 128-kda protein which we termed po-ga [lu et al., biochem. biophys. res. commun. 193 (1993) 779-786]. in the present report, we compared po-ga to recent dna database entries and determined that po-ga was 80% identical, at the amino-acid level, to the large subunit of replication factor c (activator 1) cloned from mouse [burbelo et al., proc. natl. acad. sci. usa 91 (1994) in press]. this indicates that po-ga probably represents the corresponding ... | 1994 | 7914507 |
| overexpression and purification of the carboxyl-terminal nucleotide-binding domain from mouse p-glycoprotein. strategic location of a tryptophan residue. | the cdna encoding the c-terminal nucleotide-binding domain (nbd2) from mouse p-glycoprotein involved in multidrug resistance was obtained from adrenal cell mrna and amplified by reverse transcriptase polymerase chain reaction. nbd2 was highly overexpressed in escherichia coli in fusion with glutathione s-transferase and could be purified after efficient thrombin cleavage. both fused and purified nbd2 bound tnp (2',3'-o-(2,4,6-trinitrophenyl))- derivatives of nucleotides with high affinity. tnp-a ... | 1994 | 7916013 |
| quantitation of icam-1 expression in mouse lung during pneumonia. | in the systemic circulation, neutrophil emigration into sites of acute inflammation is mediated through the leukocyte adhesion complex, cd11/cd18. icam-1 is an inducible endothelial ligand for cd11a/cd18 and cd11b/cd18. streptococcus pneumoniae elicits neutrophil emigration through a cd18-independent mechanism whereas escherichia coli endotoxin elicits emigration through a cd18-dependent mechanism in rabbit lungs. to determine whether icam-1 is up-modulated in the lung during cd18-independent an ... | 1994 | 7916369 |
| isolation of the chicken nf-kappa b p65 subunit-encoding cdna and characterization of its products. | nf-kappa b is a heterodimeric transcription factor consisting of subunits of 50 kda (p50) and 65 kda (p65). cdna clones encoding the chicken nf-kappa b p65 subunit were isolated. sequence analysis showed that chicken p65 is approximately 55% identical to the mouse and human p65 proteins, and contains the rel homology domain (rhd) in its n-terminal 286 amino acids (aa) and the putative transactivation domain in its c-terminal region. the rhd is particularly highly conserved between the chicken an ... | 1993 | 7916720 |
| dimerization characteristics of the dna- and steroid-binding domains of the androgen receptor. | the dna-binding domain (dbd) of the androgen, mineralocorticoid, and glucocorticoid receptors and the steroid-binding domain (sbd) of the androgen receptor (ar) were expressed separately as fusion proteins with glutathione-s-transferase (gst) in escherichia coli. native polyacrylamide gel electrophoresis and gel exclusion hplc demonstrated that the gst-ardbd fusion protein was present as a dimer. on the other hand, the gst-arsbd fusion protein formed a high-molecular weight oligomer, which seeme ... | 1994 | 7918108 |
| the expression of escherichia coli diaminopimelate decarboxylase in mouse 3t3 cells. | we have subcloned the coding sequence for the escherichia coli lysa gene coding for diaminopimelic acid decarboxylase (dap decarboxylase) into a eukaryotic expression vector based on the sv40 early promoter. the activities of a series of constructs with different lengths of non-coding dna at the 5' and 3' ends of the coding region have been compared by measuring the synthesis of lysine from diaminopimelic acid (dap) in mouse 3t3 cells. a short non-coding sequence at the 3' end reduced the expres ... | 1994 | 7918636 |
| characterization of an arabidopsis cdna for a soluble epoxide hydrolase gene that is inducible by auxin and water stress. | a cdna (1122 bp) was isolated from a cdna library prepared from arabidopsis thaliana l. that had been subjected to drought stress for 1 h. the sequencing of a genomic clone corresponding to the cdna and s1 mapping analysis revealed that the cdna lacked the first 6 bp from its translational start (atg). the resulting open reading frame encodes a polypeptide of 321 amino acids, and the calculated molecular weight of this polypeptide is 36,423 da. the deduced amino acid sequence shows a high degree ... | 1994 | 7920716 |
| a role for metallothionein and zinc in spontaneous mutagenesis. | g12, a transgenic chinese hamster v79 cell derivative which contains a single copy of the escherichia coli gpt gene as a target for mutagenesis, has little constitutive metallothionein (mt) expression. it was transfected with a vector containing the mouse mt-i gene, and mt-i-overproducing lines were isolated. mt-i transfectants had lower spontaneous mutation frequencies compared with the g12 parental cell line. mutagenesis by alkylating agents was unchanged. mt expression in g12 and mt transfect ... | 1994 | 7923159 |
| monoclonal antibodies specific for shigella dysenteriae serotype 13. production, characterization, and diagnostic application. | three mouse monoclonal antibodies (mabs) (icl3, icl4, and icl5) were produced that specifically recognized the lipopolysaccharide antigen of the newly recognized shigella dysenteriae serotype-13 strain. all three mabs reacted with all nine reference isolates of s. dysenteriae 13 in different tests. the mabs also detected colonies of s. dysenteriae-13 isolates by direct slide agglutination test. the mabs also reacted with the reference escherichia coli 0150 strain and showed its close antigenic r ... | 1994 | 7924205 |
| interleukin-3 and lipopolysaccharide interact to inhibit proliferation of mouse bone marrow cells. | the mechanisms underlying the multiple biological activities presented by interleukin-3 (il-3) are not yet fully understood. as a regulator of hematopoiesis, il-3 is known to interact with several other molecules. the present study investigates the interaction of il-3 and escherichia coli lipopolysaccharide (lps), which results in the inhibition of the in vitro proliferation of mouse bone marrow (bm) cells. bm cells from adult balb/c mice were cultured at 37 degrees c, with 5% co2 in air, in rpm ... | 1994 | 7927514 |
| mouse paneth cell defensins: primary structures and antibacterial activities of numerous cryptdin isoforms. | cryptdins are antimicrobial peptides of the defensin family that are produced by intestinal paneth cells. mrnas encoding 17 cryptdin isoforms have been characterized from a cdna library generated from a single jejunal crypt. six cryptdin cdnas correspond to known peptides, and the remainder predict 11 novel paneth cell defensins. most cryptdin cdnas have > or = 93% nucleotide sequence identity overall, except for cryptdin 4 and 5 cdnas, whose respective mature peptide-encoding regions are only 7 ... | 1994 | 7927786 |
| 2 cloning and expression of mouse deoxycytidine kinase. pure recombinant mouse and human enzymes show differences in substrate specificity. | a cdna encoding mouse deoxycytidine kinase (dck) (ec 2.7.1.74) was cloned from a mouse t-cell lambda zap cdna library. an insert of 2.8 kilobases (kb) contained the entire coding sequence of 780 base pairs. the protein coding sequence was 88% homologous at the nucleotide level with human dck cdna (chottiner, e. g., shewach, d. s., datta, n. s., ashcraft, e., gribbin, d., ginsburg, d., fox, i. h., and mitchell, b. s. (1991) proc. natl. acad. sci. u. s. a. 88, 1531-1535). at the amino acid level t ... | 1994 | 7929097 |
| catalytic properties of mouse carbonic anhydrase v. | a cdna encoding the mouse carbonic anhydrase v gene was isolated by reverse transcription and polymerase chain reaction from balb/c mouse liver mrna. vectors containing the full coding sequence as well as two different nh2-terminal truncated genes expressed enzymatically active protein in escherichia coli. the carbonic anhydrase v produced by a vector containing the full coding sequence, which includes a possible nh2-terminal mitochondrial targeting signal, was proteolytically processed by e. co ... | 1994 | 7929150 |
| delta 9 acyl-lipid desaturases of cyanobacteria. molecular cloning and substrate specificities in terms of fatty acids, sn-positions, and polar head groups. | in cyanobacteria, the biosynthesis of unsaturated fatty acids is initiated by delta 9 acyl-lipid desaturase which introduces the first double bond at the delta 9 position of a saturated fatty acid that has been esterified to a glycerolipid. we have cloned genes, designated desc, for delta 9 acyl-lipid desaturases from two cyanobacteria, namely anabaena variabilis and synechocystis sp. pcc 6803. these desaturases, when expressed in escherichia coli, desaturated stearic acid to yield oleic acid at ... | 1994 | 7929259 |
| the lymphoid transcription factor lyf-1 is encoded by specific, alternatively spliced mrnas derived from the ikaros gene. | the lymphocyte-specific dna-binding protein lyf-1 interacts with a critical control element in the terminal deoxynucleotidyltransferase (tdt) promoter as well as with the promoters for other genes expressed during early stages of b- and t-cell development. we have purified lyf-1 and have obtained a partial amino acid sequence from proteolytic peptides. the amino acid sequence suggests that lyf-1 is a zinc finger protein encoded by the ikaros gene, which previously was implicated in t-cell develo ... | 1994 | 7935426 |
| recombinant single-chain fv fragments carrying c-terminal cysteine residues: production of bivalent and biotinylated miniantibodies. | a murine antibody single-chain fv (scfv) fragment carrying five c-terminal histidine residues preceded by a cysteine residue and a marker peptide was expressed in escherichia coli. its variable heavy (vh) and light (vl) domains are derived from the mouse monoclonal antibody mab215, which is specific for the largest subunit of rna polymerase ii of drosophila melanogaster. scfv' monomers, covalently linked (scfv')2 and non-covalent dimers, as well as aggregated antibody fragments, were isolated fr ... | 1994 | 7935496 |
| propagation of pseudorabies virus in the nervous system of the mouse after intranasal inoculation. | the propagation of pseudorabies virus (prv) in the mouse nervous system was studied after intranasal inoculation of a prv mutant expressing beta-galactosidase after insertion of the escherichia coli lac-z gene into the gene encoding the nonstructural, nonessential glycoprotein gg. this allowed rapid detection of infected cells by a single step reaction with the substrate x-gal. the gg-beta-gal+ mutant behaved like the wild-type kaplan strain of origin. the incubation period was very short and th ... | 1994 | 7941329 |
| demonstration of the target molecule of a protective ige antibody in secretory glands of schistosoma japonicum larvae. | we have demonstrated that a mouse monoclonal ige antibody, sj18 epsilon.1, recognizes a 97 kda surface molecule (sj97) of schistosoma japonicum larvae and that the antibody induces partial but significant protection against the skin to lung-stage of s. japonicum infection. the antibody stimulates eosinophil- and macrophage-mediated killing of schistosomula in vitro. in the present study, we isolated the putative full-length cdna of sj97 by screening a lambda gt11 cdna library from s. japonicum a ... | 1994 | 7947464 |
| purification, bioactivity, and secondary structure analysis of mouse and human macrophage migration inhibitory factor (mif). | the cytokine macrophage migration inhibitory factor (mif) has been identified to be secreted by the pituitary gland and the monocyte/macrophage and to play an important role in endotoxic shock. despite the recent molecular cloning of a human t-cell mif, characterization of the biochemical and biological properties of this protein has remained incomplete because substantial quantities of purified, recombinant, or native mif have not been available. we describe the cloning of mouse mif from anteri ... | 1994 | 7947826 |
| carcinogenicity and mutagenicity studies with fluvastatin, a new, entirely synthetic hmg-coa reductase inhibitor. | the hmg-coa reductase inhibitors are a new and novel class of cholesterol-lowering agents which are widely used worldwide. fluvastatin is the first entirely synthetic compound in this class and is structurally distinct from fungal metabolite derivatives which are already marketed. as the liver is the site of some toxic effects for these compounds, it was not entirely unexpected that liver cancer was found in rats and/or mice with the first three marketed compounds, lovastatin, pravastatin, and s ... | 1994 | 7958569 |
| isolation and characterization of the cdna encoding the channel catfish (ictalurus punctatus) form of cytochrome p450arom. | cytochrome p450arom (aromatase) is responsible for the conversion of androgens to estrogens. a cdna library was constructed from poly(a)-enriched mrna isolated from channel catfish (ictalurus punctatus) ovary and ligated into ecori-cut lambda arms. the amplified library was screened using a human aromatase dna probe. the longest clone isolated (2.1 kb) contained 20 bp of the 5'-untranslated region, a 1572-bp open reading frame, and a 509-bp 3'-untranslated region. northern blot analysis indicate ... | 1994 | 7958747 |
| the salmonella typhimurium katf (rpos) gene: cloning, nucleotide sequence, and regulation of spvr and spvabcd virulence plasmid genes. | the spv region of salmonella virulence plasmids is essential for the development of a systemic infection in mice. transcriptional activation of the spvabcd operon occurs during stationary growth phase and is mediated by the regulatory gene product spvr. we have previously shown that expression of a spvrab'-cat fusion in escherichia coli was dependent on the katf (rpos) locus which encodes an alternative sigma factor (sigma s). the katf gene from salmonella typhimurium has been cloned, sequenced, ... | 1994 | 7961444 |
| cell cycle analysis and chromosomal localization of human plk1, a putative homologue of the mitotic kinases drosophila polo and saccharomyces cerevisiae cdc5. | polo and cdc5 are two genes required for passage through mitosis in drosophila melanogaster and saccharomyces cerevisiae, respectively. both genes encode structurally related protein kinases that have been implicated in regulating the function of the mitotic spindle. here, we report the characterization of a human protein kinase that displays extensive sequence similarity to drosophila polo and s. cerevisiae cdc5; we refer to this kinase as plk1 (for polo-like kinase 1). the largest open reading ... | 1994 | 7962193 |
| construction of mutant genes for a non-toxic verotoxin 2 variant (vt2vp1) of escherichia coli and characterization of purified mutant toxins. | the gene encoding a verotoxin 2 variant, vtvp1, was mutated by oligonucleotide-directed site-specific mutagenesis. among 6 mutant toxins encoded by the mutated genes, e167q-r170l (glutamic acid at position 167 and arginine at position 170 from n-terminus of the a subunit were replaced by glutamine and leucine, respectively) was found to have markedly decreased activities; inhibition of protein synthesis, vero cell cytotoxicity and mouse lethality of the purified e167q-r170l were 1/1,900, 1/125,0 ... | 1994 | 7968674 |
| characterization and use of crude alpha-subunit preparations for quantitative immunoblotting of g proteins. | g proteins are heterotrimeric membrane-associated proteins that couple a large number of receptors to a variety of effector systems within the cell. characterization of g proteins expressed in a particular cell type represents an important first step in defining the potential candidates to which a receptor might couple. a difficulty often encountered using g protein antisera from various commercial and private sources is relating the intensity of bands on a western blot to the relative amount of ... | 1994 | 7978261 |
| binding protein for escherichia coli heat-stable enterotoxin ii in mouse intestinal membrane. | the protein binding escherichia coli heat-stable enterotoxin ii (stii) was isolated from cell membranes of mouse intestine. the binding of 125i-labeled stii to the proteins was inhibited by unlabeled stii, showing that it is specific. proteins cross-linked with 125i-stii were purified by column chromatography on hydroxyapatite and tsk gel. analyses of the purified protein by sds-polyacrylamide gel electrophoresis and gel filtration showed that the molecular mass was 25 kda. | 1994 | 7988871 |
| intestinal kinetics and dynamics of escherichia coli heat-stabile enterotoxin in suckling mice. | the heat-stabile enterotoxin produced by escherichia coli (st) induces diarrhea by binding to receptors on intestinal cells, activating guanylyl cyclase, and increasing cyclic gmp. high- and low-affinity receptors for this toxin have been identified previously. st induces intestinal secretion in suckling mice in picomole doses, suggesting a role for high-affinity receptors in this process. the present studies examine the relative roles of high- and low-affinity receptors in this process. the tim ... | 1994 | 7995990 |
| escherichia coli heat-labile enterotoxin b subunits supplemented with a trace amount of the holotoxin as an adjuvant for nasal influenza vaccine. | escherichia coli heat-labile enterotoxin b subunit (ltb) (2 micrograms), supplemented with a trace amount of the holotoxin (lt) (0.02-20 ng), was examined for the adjuvant effect on antibody (ab) responses against influenza inactivated haemagglutinin (ha) vaccine in balb/c mice. each mouse received a primary intranasal (i.n.) inoculation with the vaccine (1.5 micrograms), prepared from pr8 (h1n1) virus, together with lt-containing ltb and in 4 weeks a second i.n. inoculation of the vaccine alone ... | 1994 | 7998417 |
| isolation and characterization of a cdna that codes for a lim-containing protein which is developmentally regulated in heart. | during our human heart cdna sequencing project, we have obtained a novel cdna clone which is very similar in dna and amino acid sequences to a rat/mouse cysteine-rich intestinal protein (1). sequence analysis has shown that this human cysteine-rich heart protein (hcrhp) is a protein of 77 amino acids and possesses a lim motif which is considered to be able to bind zinc. northern blot analyses have shown that its mrna level in rat heart is regulated developmentally. we have expressed hcrhp in e. ... | 1994 | 7999070 |
| high level expression of human leukemia inhibitory factor (lif) from a synthetic gene in escherichia coli and the physical and biological characterization of the protein. | lif is a multi-functional cytokine that elicits effects on a broad range of cell types. in this report, we present the high level expression of human lif (hlif) from a chemically synthesized gene template in escherichia coli where it comprises up to 25% of the cellular protein. the recombinant hlif, after purification and folding, was examined using cd, ftir spectroscopy and light scattering. cd and ftir spectra showed that the hlif is an alpha-helical protein and has a distinct tertiary structu ... | 1995 | 7999791 |
| molecular cloning and functional expression of a cdna for mouse squalene synthase. | using a probe obtained by pcr amplification, a full-length cdna encoding squalene synthase was isolated from a mouse liver cdna library. its nucleotide sequence had an open reading frame fro a 416 amino acid polypeptide (calculated molecular mass, 48 kda). in vitro transcription of the cdna followed by in vitro translation produced a protein of the expected size. the deduced amino acid sequence was 93%, 88% and 46% identical to those of the rat, human and budding yeast squalene synthases, respec ... | 1995 | 7999794 |
| cytokines induce nitric oxide production in mouse osteoblasts. | mc3t3-e1 mouse clonal osteogenic cells were incubated with interferon-gamma, interleukin-1 beta, tumor necrosis factor-alpha, and e. coli lipopolysaccharide. tnf alpha, il-1 beta, and lps caused a dose- and time-dependent increase of nitrite (no2-), the stable metabolite of nitric oxide (no), in conditioned media over 48 hours, while ifn gamma had a minimal effect. different combinations of the same factors caused a synergistic enhancement of no2- accumulation, except for il-1 beta with lps. the ... | 1994 | 8003032 |
| specific dna probes to detect escherichia coli strains producing cytotoxic necrotising factor type 1 or type 2. | cytotoxic necrotising factors type 1 (cnf1) and type 2 (cnf2) are produced by many escherichia coli strains isolated from man and animals with intestinal or extra-intestinal colibacillosis. in most laboratories, cnf-producing strains are detected by a cell cytotoxicity assay and confirmed with a neutralisation assay or a mouse footpad assay. in this study, we sought to determine whether dna probes could detect clinical isolates of e. coli producing cnf2 or cnf1, or both, without the need for cel ... | 1994 | 8006936 |
| m1 protein and protein h: iggfc- and albumin-binding streptococcal surface proteins encoded by adjacent genes. | m1 protein and protein h are surface proteins simultaneously present at the surface of certain strains of streptococcus pyogenes, important pathogenic bacteria in humans. the present study concerns the structure, protein-binding properties and relationship between these two molecules. the gene encoding m1 protein (emm1) was found immediately upstream of the protein h gene (sph). both genes were preceded by a promoter region. comparison of the sequences revealed a high degree of similarity in the ... | 1994 | 8010973 |
| ablation of e2a in recombinant adenoviruses improves transgene persistence and decreases inflammatory response in mouse liver. | first-generation recombinant adenoviruses that lack e1 sequences have shown tremendous promise in animal and human models of gene therapy. important limitations of these vectors are that recombinant gene expression is transient and inflammation occurs at the site of gene transfer. our hypothesis for generating vectors with increased persistence is that present recombinant adenoviruses express viral proteins that stimulate cellular immune responses leading to destruction of the infected cells and ... | 1994 | 8016137 |
| induction of manganese superoxide dismutase by cytokines and lipopolysaccharide in cultured mouse astrocytes. | to determine whether cytokines or lipopolysaccharide (lps) are involved in the induction of superoxide dismutase (sod) in the nervous system, we examined the effects of these substances on the levels of sod in cultured mouse astrocytes. treatment of astrocytes with 10(2) to 10(4) u/ml tumor necrosis factor-alpha for 3 days increased the levels of mn sod in a dose- and time-dependent manner to as much as six times the level under nontreated conditions. treatment with 1.0 microgram/ml lps for 3 da ... | 1994 | 8035184 |
| host specificity of enteropathogenic escherichia coli from rabbits: lack of correlation between adherence in vitro and pathogenicity for laboratory animals. | the pathogenicity of four attaching and effacing strains of enteropathogenic escherichia coli originally isolated from diarrheic rabbits was investigated by inoculating them perorally into rabbits, guinea pigs, and mice. the ability of the four strains to adhere to cultured epithelial cells, erythrocytes, and intestinal brush borders from various animal species, including rabbits, guinea pigs, and mice, varied considerably. only one strain carried af/r1 fimbriae, which are believed to determine ... | 1994 | 8039904 |
| activation of hepatic proliferation-associated transcription factors by lipopolysaccharide. | the hepatic acute-phase response is the result of reprogramming of gene expression in the liver. similar acute-phase responses occur in regenerating liver after partial hepatectomy and are preceded by increases in the expression of a set of transcriptional regulatory proteins that are encoded by "immediate-early" genes. the purpose of this study was to determine whether acute systemic inflammation after lipopolysaccharide injection induces hepatic immediate-early genes that are induced by partia ... | 1994 | 8048002 |
| characterization of mouse phosphatidylinositol transfer protein expressed in escherichia coli. | the cdna encoding mouse phosphatidylinositol transfer protein (pi-tp) was isolated by means of reverse transcriptase polymerase chain reaction. the nucleotide sequence of this cdna has a high similarity (98%) with that of rat pi-tp; the predicted amino acid sequence is 99.6% identical to that of rat pi-tp. the cdna encoding mouse pi-tp was cloned into the expression vector pet3d and the escherichia coli strain bl21(de3) was transformed with the resulting plasmid. after induction of the bacteria ... | 1994 | 8049244 |
| probing the conformational changes in 5.8s, 18s and 28s rrna upon association of derived subunits into complete 80s ribosomes. | the participation of 18s, 5.8s and 28s ribosomal rna in subunit association was investigated by chemical modification and primer extension. derived 40s and 60s ribosomal subunits isolated from mouse ehrlich ascites cells were reassociated into 80s particles. these ribosomes were treated with dimethyl sulphate and 1-cyclohexyl-3-(morpholinoethyl) carbodiimide metho-p-toluene sulfonate to allow specific modification of single strand bases in the rrnas. the modification pattern in the 80s ribosome ... | 1994 | 8052533 |
| optimal times above mics of ceftibuten and cefaclor in experimental intra-abdominal infections. | the duration of time that serum drug levels remain above the mic (time above the mic) for the pathogen has been shown to be the most significant parameter determining the efficacies of beta-lactam antibiotics. in the described study, we investigated the optimal time above the mic of ceftibuten and cefaclor using a nonneutropenic mouse model of intra-abdominal infections caused by staphylococcus aureus, escherichia coli, klebsiella pneumoniae, and streptococcus pneumoniae. the abilities of the dr ... | 1994 | 8067747 |
| intestinal tissue distribution and epithelial transport of the oral immunogen ltb, the b subunit of e. coli heat-labile enterotoxin. | ltb provokes a systemic immune response and exerts adjuvant effects on mucosal immune responses to unrelated antigens. the binding and uptake of fluorescein-labelled ltb in the normal villus epithelium was compared to that in peyer's patch dome epithelium in mouse intestine. ltb was bound by the gm1-receptor and taken up extensively by both tissues, indicating that not only the peyer's patches but also the normal villus epithelium play a significant role in the transport of orally administered a ... | 1993 | 8069576 |
| a salmonella protein that is required for resistance to antimicrobial peptides and transport of potassium. | the ability of invading pathogens to proliferate within host tissues requires the capacity to resist the killing effects of a wide variety of host defense molecules. sap mutants of the facultative intracellular parasite salmonella typhimurium exhibit hypersensitivity to antimicrobial peptides, cannot survive within macrophages in vitro and are attenuated for mouse virulence in vivo. we conducted a molecular genetic analysis of the sapg locus and showed that it encodes a product that is 99% ident ... | 1994 | 8076592 |
| major core protein vp7 of australian bluetongue virus serotype 15: sequence and antigenicity divergence from other btv serotypes. | full-length cdna of the rna genome segment coding for the major core protein vp7 of australian bluetongue virus serotype 15 (btv-15) has been isolated by reverse transcription-pcr cloning. comparative analysis indicated that the btv-15 vp7 sequence had diverged significantly from that of other members of the btv serogroup. at the amino acid level, btv-15 vp7 exhibited sequence identities of 80 to 84% with vp7 molecules of other serotypes, significantly lower than the sequence identities of betwe ... | 1994 | 8077943 |
| homology-associated nonhomologous recombination in mammalian gene targeting. | nonhomologous (illegitimate) recombination of dna underlies many changes in the genome. it involves no or little homology between recombining dnas and has been considered unrelated with homologous recombination, which requires long homology. in mouse cells, however, we found recombination products whose sequences suggest that homologous interaction between dnas caused nonhomologous recombination with another dna. the intermediates of homologous recombination were apparently trapped at various st ... | 1994 | 8078916 |