| inhibition of in vitro dna chain elongation of 5-trifluoromethyl-2'-deoxyuridine residue in the template. | 5-trifluoromethyl-2'-deoxyuridine (cf3durd) is incorporated into the dna of mammalian cells in culture. we have synthesized oligonucleotides that allows site specific introduction of cf3durd residue into synthetic dna oligonucleotide. we described here the utilization of these oligonucleotides as template for in vitro dna synthesis. when cf3durd residue located at an internucleotide site in the template, the chain elongation was partially arrested one nucleotide after or before the cf3durd resid ... | 1991 | 1842086 |
| role of trypanosoma cruzi lipopolysaccharide on human granulocyte biological activities. | | 1991 | 1842440 |
| pucv11001, an inch plasmid isolated in a escherichia coli strain from a healthy child. | plasmids conferring resistance to potassium tellurite but not to other antimicrobial agents were detected among e. coli multiresistant strains isolated from healthy children during a survey in caracas. few of them were autotransferable to e. coli k12 and they were conjugative only at temperatures below 30 degrees c. they also conferred to the host cells resistance to lethal action of colicin b, pacb character. pucv11001, a prototype, was classified into the incompatibility group hi, subgroup hi2 ... | 1991 | 1843777 |
| isolation of cdnas for dna-binding proteins which specifically bind to a tax-responsive enhancer element in the long terminal repeat of human t-cell leukemia virus type i. | one of the gene products of human t-cell leukemia virus type i (htlv-i), p40tax, activates its own viral transcription in trans through tax-responsive enhancers in viral long terminal repeats. five species of cdna clones for proteins that bind to the tax-responsive enhancer element in htlv-i were isolated from the jurkat cell library. the beta-galactosidase fusion protein prepared from the lysogen of a clone specifically recognized the cyclic amp-responsive element in htlv-i enhancer. the nucleo ... | 1991 | 1847461 |
| isolation and characterization of cdna clones for rat liver 10-formyltetrahydrofolate dehydrogenase. | we have isolated and characterized cdna clones encoding rat liver cytosol 10-formyltetrahydrofolate dehydrogenase (ec 1.5.1.6). an open reading frame of 2706 base pairs encodes for 902 amino acids of mr 99,015. the deduced amino acid sequence contains exact matches to the nh2-terminal sequence (28 residues) and the sequences of five peptides derived from cyanogen bromide cleavage of the purified protein. the amino acid sequence of 10-formyltetrahydrofolate dehydrogenase has three putative domain ... | 1991 | 1848231 |
| two nicking enzyme systems specific for mismatch-containing dna in nuclear extracts from human cells. | we have identified two novel enzyme systems in human hela nuclear extracts that can nick at specific sites of dna molecules with base mismatches, in addition to the t/g mismatch-specific nicking enzyme system (wiebauer, k., and jiricny, j. (1989) nature 339, 234-236). one enzyme (called all-type) can nick all eight base mismatches with different efficiencies. the other (a/g-specific) nicks only dna containing an a/g mismatch. the all-type enzyme can be separated from the t/g-specific and a/g-spe ... | 1991 | 1848856 |
| hemolytic and microbicidal actions of diethyldithiocarbamic acid. | micromolar concentrations of diethyldithiocarbamic acid (ddc) kill fungi, bacteria and malaria. ddc forms chelates with copper and the microbicidal effectiveness of this drug is enhanced greatly by small amounts of copper. ddc, in the presence of at least 1 molar equivalent of copper, also causes lysis of human erythrocytes. to explore the cytocidal actions of ddc and copper, we have used human erythrocytes and escherichia coli as models. we found that: (1) the combination of ddc and copper also ... | 1991 | 1848982 |
| endogenous incorporation of nitric oxide from l-arginine into n-nitrosomorpholine stimulated by escherichia coli lipopolysaccharide in the rat. | the endogenous formation of nitrate in the rat, mouse and human occurs through cellular processes involving the oxidation of the guanido group of arginine. these processes proceed from arginine to nitric oxide with subsequent conversion to electrophilic nitrosating agents capable of forming carcinogenic nitrosamines. we have now demonstrated that endogenous nitrosamine formation can occur via cells stimulated in vivo by bacterial lipopolysaccharide (lps). the nitrosation of morpholine given to r ... | 1991 | 1849054 |
| effect of a siliconized latex urinary catheter on bacterial adherence and human neutrophil activity. | the effect of a siliconized latex urinary catheter on the in vitro adherence and growth of pseudomonas aeruginosa and escherichia coli and on the activity of human polymorphonuclear leukocytes (pmns) was assessed. the adherence of p. aeruginosa to latex catheters was significantly greater than that of e. coli, being 30 times higher at 6 hr of incubation. the survival of e. coli (10(8) cfu/ml) in phosphate-buffered saline (pbs) containing segments of siliconized latex catheters was lower than in ... | 1991 | 1849474 |
| effects of mcr restriction of methylated cpg islands of the l1 transposons during packaging and plating stages of mammalian genomic library construction. | the use of optimally methylation-tolerant mcra- mcrb- strains has been shown to produce an over tenfold increase in the plating efficiencies of mammalian genomic libraries, compared to a superior conventional phage host strain le392 which is mcrb+. however, there is an even more significant effect of mcr restriction. amongst the recombinants recovered with an mcrb+ host, we have found that there is an additional 30-fold reduction in the frequencies of clones containing the heavily methylated 5'- ... | 1991 | 1849497 |
| recombinant human interleukin 3 induces proliferation of inflammatory cells and keratinocytes in vivo. | in this preclinical study we investigated the effect(s) of recombinant human (rh) interleukin 3 (il-3) on hemopoietic differentiation and attempted to evaluate possible clinical side effects of this hemopoietic growth factor. rh il-3, derived from either escherichia coli or chinese hamster ovary, was administered subcutaneously to 16 rhesus monkeys (by pairs) at different doses (11, 33, and 100 micrograms/kg/day) for 14 days. during the 2nd week of administration white blood cell counts increase ... | 1991 | 1850054 |
| identification of two neutrophil chemotactic peptides produced by porcine alveolar macrophages. | we have purified to homogeneity two distinct 10-kda proteins with potent chemotactic activity for neutrophils from porcine alveolar macrophages incubated for 24 h with escherichia coli endotoxin (lipopolysaccharide (lps), 10 micrograms/ml). neutrophil chemotactic activity in alveolar macrophage supernatants was concentrated by adsorption to sp-sephadex, and purified by cation exchange and reversed phase high performance liquid chromatography. the first peptide, alveolar macrophage chemotactic fa ... | 1991 | 1850745 |
| autoantibodies to dna topoisomerase ii in juvenile rheumatoid arthritis. | sera from 58 children with juvenile rheumatoid arthritis were examined for the presence of antibodies to dna topoisomerase ii. eight sera were reactive in immunoblotting with purified human topoisomerase ii and a protein encoded by a cloned cdna expressed in escherichia coli which represents the carboxy-terminal domain of the human enzyme. in addition, the sera detect topoisomerase ii in mitotic chromosomes and chromosome scaffolds. five of the sera bind to the native enzyme in solution and depl ... | 1991 | 1851057 |
| [the pyrogenicity of lipopolysaccharide-contaminated human albumin solutions]. | | 1991 | 1852766 |
| an in vitro novel mechanism of regulating the activity of pyruvate kinase m2 by thyroid hormone and fructose 1, 6-bisphosphate. | we have recently shown that the cytosolic thyroid hormone binding protein (p58-m2) in human epidermoid carcinoma a431 cells is a monomer of pyruvate kinase, subtype m2 (pkm2). to characterize further the molecular properties of p58-m2, we overexpressed p58-m2 in escherichia coli and purified it to homogeneity. at 22 degrees c, the monomeric p58-m2, exhibited kinase activity with an apparent vmax of 22 +/- 9 units/mg. the km for adenosine diphosphate (adp) and phosphoenolpyruvate (pep) are 3.85 + ... | 1991 | 1854723 |
| restructuring the translation initiation region of the human parathyroid hormone gene for improved expression in escherichia coli. | overexpression of native human parathyroid hormone in escherichia coli was achieved by a modification of the 5' end of the genomic gene sequence, thereby adapting this part of the translation initiation region to the bacterial host. some simple rules abstracted from optimization studies of translation initiation of a beta-interferon gene were applied. these included (a) extending complementarity of the mrna to the anticodon loop of trnafmet by use of a codon with a purine nucleotide directly fol ... | 1991 | 1859835 |
| characterization of a maize cdna that complements an enolase-deficient mutant of escherichia coli. | a cdna encoding maize enolase (2-phospho-d-glycerate hydrolase) was purified by functional genetic complementation using an enolase deficient mutant of escherichia coli, df261. this cdna, pzm245, was characterized by restriction mapping and dna sequence analysis. the cdna contained an open reading frame encoding a protein of 446 amino acids with a high degree of similarity to enolase sequences from other organisms (72% identity to yeast enolase and 82% identity to human enolase). the pzm245 cont ... | 1991 | 1859865 |
| reduced alveolar macrophage production of tumor necrosis factor during sepsis in mice and men. | tumor necrosis factor (tnf) has been implicated as a major humoral mediator of sepsis and endotoxin shock. tnf is secreted by cells of the reticuloendothelial system, including alveolar macrophages. alveolar macrophage tnf production has been postulated to play a pathogenetic role in the development of adult respiratory distress syndrome (ards) in sepsis. to evaluate alveolar macrophage production of tnf during sepsis and endotoxin shock, we studied the effects of sepsis and/or in vivo lipopolys ... | 1991 | 1860332 |
| [tetracycline resistance in oral microorganisms in patients with periodontal disease]. | several longitudinal studies have shown that periodontal treatment consisting of surgical and/or nonsurgical debridement of the teeth often is sufficient to prevent continued attachment loss when the patients' oral hygiene measures are good. nevertheless, some patients will, in spite of excellent oral hygiene measures, continue to show attachment loss. the treatment of these patients has mainly been empirical, and the clinicians have used different kinds of antibiotics for different time interva ... | 1991 | 1861963 |
| homology between proteins controlling streptomyces fradiae tylosin resistance and atp-binding transport. | a tylosin(ty)-producing strain of streptomyces fradiae contains at least three genes, tlra, tlrb, tlrc, specifying resistance to ty (tyr). the complete nucleotide sequence of the tyr-encoding gene, tlrc, and the transcription start point of the gene were determined. the sequence contains an open reading frame coding for a protein of 548 amino acids (aa) with an mr of 59129. the tlrc protein was identified by expression of the cloned gene by in vitro coupled transcription and translation in cell- ... | 1991 | 1864505 |
| dna unwinding produced by site-specific intrastrand cross-links of the antitumor drug cis-diamminedichloroplatinum(ii). | the dna unwinding produced by specific adducts of the antitumor drug cis-diamminedichloroplatinum(ii) has been quantitatively determined. synthetic dna duplex oligonucleotides of varying lengths with two base pair cohesive ends were synthesized and characterized that contained site-specific intrastrand n7-purine/n7-purine cross-links. included are cis-[pt(nh3)2[d(gpg)]], cis-[pt(nh3)2(d(apg)]], and cis-[pt(nh3)2[d(gptpg)]] adducts, respectively referred to as cis-gg, cis-ag, and cis-gtg. local d ... | 1991 | 1868076 |
| comparison of the early dynamics of systemic prostacyclin release after administration of tumor necrosis factor and endotoxin to healthy humans. | excessive production of prostaglandins may be of importance for the development of organ damage in generalized infection. to investigate the role of tumor necrosis factor (tnf) in systemic prostacyclin release in gram-negative septicemia, the plasma concentrations of its stable metabolite 6-keto-prostaglandin f1 alpha (6-keto-pgf1 alpha) were sequentially measured after intravenous bolus injections of recombinant human tnf (50 micrograms/m2; n = 6) and escherichia coli endotoxin (2 ng/kg; n = 3) ... | 1991 | 1869846 |
| prevention of human immunodeficiency virus type 1 integrase expression in escherichia coli by a ribozyme. | ribozymes are potentially very powerful agents for perturbing intracellular gene expression. however, pilot experiments in eukaryotes have met with mixed success. we now report that a ribozyme designed to cleave the integrase gene of the human immunodeficiency virus (hiv), when transcribed from a plasmid in escherichia coli, led to destruction of integrase rna and complete blockage of integrase protein synthesis. these results indicate that ribozymes can be used to study intracellular gene expre ... | 1991 | 1871136 |
| [1-14c]oleate-labeled autoclaved yeast: a membranous substrate for measuring phospholipase a2 activity in vitro. | radiolabeled, autoclaved yeast were tested as a substrate for mammalian phospholipase a2 activity because the only other membranous substrate used for this purpose, autoclaved escherichia coli, totally lacks a major mammalian phospholipid, phosphatidylcholine. candida albicans were grown in the presence of [1-14c]oleate and then autoclaved. sixty three percent of the incorporated label was in yeast phospholipid, and more than 95% of that was in the 2-acyl position. the distribution of label in t ... | 1991 | 1872466 |
| multiple carg boxes in the human cardiac actin gene promoter required for expression in embryonic cardiac muscle cells developing in vitro from embryonal carcinoma cells. | chimeric genes composed of the human cardiac actin promoter driving the escherichia coli lacz reporter gene were constructed, transfected, and stably integrated into genomes of p19 embryonal carcinoma cells. the transfected constructs were expressed actively in cardiac myocytes formed following dimethyl sulfoxide (dmso)-induced cell differentiation but poorly in undifferentiated cultures and in cultures treated with retinoic acid to develop into derivatives of the neuroectoderm. a number of dele ... | 1991 | 1875951 |
| expression of active domains of a human folate-dependent trifunctional enzyme in escherichia coli. | the cdna encoding the human trifunctional enzyme methylenetetrahydrofolate dehydrogenase-methenyltetrahydrofolate cyclohydrolase-formyltetrahydrofolate synthetase was engineered to contain a prokaryotic ribosome binding site and was expressed under the bacteriophage t7 rna polymerase promoter in escherichia coli. site-directed mutagenesis was used to prepare constructs that encode separately the dehydrogenase/cyclohydrolase (d/c) domain as amino acid residues 1-301, and the synthetase (syn) doma ... | 1991 | 1881876 |
| leukotriene a4 hydrolase: determination of the three zinc-binding ligands by site-directed mutagenesis and zinc analysis. | three mutants of recombinant mouse leukotriene a4 (lta4) hydrolase (3.3.2.6) were produced by site-directed mutagenesis on cdna. the codons corresponding to his-295, his-299, or glu-318 were replaced by codons encoding tyrosine, tyrosine, and glutamine, respectively. the mutated cdnas were expressed in escherichia coli, and the three mutated proteins were purified to apparent homogeneity. none of these mutants contained significant amounts of zinc, as determined by atomic absorption spectrometry ... | 1991 | 1881903 |
| cloning and sequencing of cdna encoding human sepiapterin reductase--an enzyme involved in tetrahydrobiopterin biosynthesis. | a full-length cdna clone for sepiapterin reductase, an enzyme involved in tetrahydrobiopterin biosynthesis, was isolated from a human liver cdna library by plaque hybridization. the nucleotide sequence of hspr 8-25, which contained an entire coding region of the enzyme, was determined. the clone encoded a protein of 261 amino acids with a calculated molecular mass of 28,047 daltons. the predicted amino acid sequence of human sepiapterin reductase showed a 74% identity with the rat enzyme. we fur ... | 1991 | 1883349 |
| induction of cytokines in normal placental cells by the human immunodeficiency virus. | placental cotyledon mononuclear cells (cmc) resemble peripheral blood monocytes/marcophages (mm) with respect to their expression of surface antigens and cellular function. cmc also express the cd4 antigen receptor and are thus susceptible to infection with the human immunodeficiency virus (hiv). when vertical transmission of hiv from mother to fetus occurs, the infection often remains latent until appropriate factors initiate the transcription of virus-specific mrna. cytokines, such as interleu ... | 1991 | 1883914 |
| fever produced by intrahypothalamic injection of interleukin-1 and interleukin-6. | pure human interleukin-1 beta (il-1 beta) and interleukin-6 (il-6), both of natural origin, were found to cause fever in rabbits when injected into the po/ah region of the brain. the threshold dose required for this effect was between 0.4 and 4 u, equivalent to 0.04 to 0.4 ng for il-1 beta, and around 50 u, equivalent to 0.05 ng for il-6. from this it was estimated that this area of the brain responds to a local concentration of approximately 1 ng/ml of these cytokines, a level which can easily ... | 1991 | 1883958 |
| clonal relationships among escherichia coli serogroup 06 isolates from human and animal infections. | the clonal relationship of thirty e. coli strains of 0 antigen serotype 06 isolated from human, dog, pig or cow infections were investigated. two main clones with serotypes 06 : h1 or 06 : h31, h- were identified. isolates from humans, dogs, pigs and cows were found in both clones, indicating that animals are a possible source for human extraintestinal escherichia coli strains. two human etec (06 : h16) and two pig isolates (06 : h10) were not related to the 06 : h1 or 06 : h31, h- e. coli clone ... | 1991 | 1884980 |
| human uracil-dna glycosylase complements e. coli ung mutants. | we have previously isolated a cdna encoding a human uracil-dna glycosylase which is closely related to the bacterial and yeast enzymes. in vitro expression of this cdna produced a protein with an apparent molecular weight of 34 k in agreement with the size predicted from the sequence data. the in vitro expressed protein exhibited uracil-dna glycosylase activity. the close resemblance between the human and the bacterial enzyme raised the possibility that the human enzyme may be able to complement ... | 1991 | 1886771 |
| o6-methylguanine-dna methyltransferase and human cancer chemotherapy. | two kinds of human tumor cell strains having different activity of o6-methylguanine-dna methyltransferase (o6-mt) were transplanted into nude mice. then the mice were injected intraperitoneally with bifunctional alkylating agent 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (acnu). the tumors with low o6-mt activity were quickly suppressed or cured. the result suggests that some tumors, if provisionally determined with low o6-mt activity, might be effici ... | 1991 | 1888434 |
| bacterial ribosomal immunostimulants prime alveolar macrophages in vivo to produce interleukin 1 in vitro. | alveolar macrophages (ams) may play a key role in human respiratory immune defenses, partially by synthesizing and releasing interleukin 1 (il = 1). d53 (ribomunyl), a composite bacterial ribosomal immunostimulant, has been recognized as an efficient prevention of respiratory tract infections. in vitro, d53 enhances the il-1 production by mouse spleen adherent cells. a thymocyte proliferative response assay was used to evaluate the in vitro il-1 production by ams in healthy subjects who received ... | 1991 | 1889248 |
| synthesis, purification, and characterization of human ciliary neuronotrophic factor from e. coli. | the cdna for human ciliary neuronotrophic factor (cntf) has been cloned into an expression vector under the control of the t7 promoter. the bl21 strain of e. coli was transformed with this vector. human cntf accounted for about 30% of the total bacterial protein after induction with isopropyl-b-d-thiogalactopyranoside. this human cntf was purified to homogeneity from inclusion bodies by a combination of ion exchange chromatography and reverse-phase high performance liquid chromatography. the ami ... | 1991 | 1890704 |
| sensitive immunoassay for rat parvalbumin: tissue distribution and developmental changes. | a sensitive enzyme immunoassay for measurements of rat parvalbumin was established using antibodies raised in rabbits with parvalbumin purified from skeletal muscles. antibodies in the antiserum were purified with a parvalbumin-coupled sepharose column. the sandwich-type immunoassay system for parvalbumin was composed of polystyrene balls with immobilized purified antibodies and the same antibodies labeled with beta-d-galactosidase from escherichia coli. the assay was highly sensitive and the mi ... | 1991 | 1892868 |
| identification of an amino acid-regulated mrna from rat liver as the mammalian equivalent of bacterial ribosomal protein l22. | amino acid deprivation of rat hepatoma cells induced the levels of a 612-base pair mrna termed asi (shay, n. f., nick, h. s., and kilberg, m. s. (1990) j. biol. chem. 265, 17844-17848). the asi mrna was present at levels equal to or greater than actin in every rat tissue tested. the corresponding full-length cdna was cloned, and the present report demonstrates that the deduced 184-residue amino acid sequence shares greater than 30% identity to a number of bacterial and chloroplast l22 ribosomal ... | 1991 | 1894596 |
| substrate specificity of recombinant human immunodeficiency virus integrase protein. | recombinant human immunodeficiency virus type 1 (hiv-1) integrase (in) produced in escherichia coli efficiently cleaves two nucleotides from the 3' end of synthetic oligonucleotide substrates which mimic the termini of hiv-1 proviral dna. efficient cleavage was restricted to hiv-1 substrates and did not occur with substrates derived from other retroviruses. mutagenesis of the u5 long terminal repeat (ltr) terminus revealed only moderate effects of mutations outside the terminal four bases of the ... | 1991 | 1895409 |
| [site-directed mutagenesis in the uracil-repair system. preparation of mutated forms of human alpha 2 interferon]. | the mutant forms of human ifn-alpha 2 gene are obtained by oligonucleotide-directed mutagenesis with the use of uracil-repair system. to intensify the process the procedure of the uracil-containing dna template preparation is modified. it was determined that when mutagenesis is performed in the uracil-repair system the yield of the process depends on the mutant dna-strand in vitro synthesis efficiency. it is shown that the stability of the 5'-end primer-template complex and the level of the endo ... | 1991 | 1896031 |
| cdna cloning of human r-type pyruvate kinase and identification of a single amino acid substitution (thr384----met) affecting enzymatic stability in a pyruvate kinase variant (pk tokyo) associated with hereditary hemolytic anemia. | cdna clones for human r-type pyruvate kinase (pk) were isolated from a human reticulocyte cdna library, constructed by pcr with a single gene-specific primer. the full-length cdna was 2060 base pairs long, and the cdna encoded 574 amino acids, the same number as that by rat r-type pk. compared with human l-type pk, r-type pk was 31 amino acids longer at the amino terminus. we also cloned and characterized r-type pk cdna clones from patients with hereditary hemolytic anemia from a pk deficiency, ... | 1991 | 1896471 |
| molecular characterization of two galactosemia mutations: correlation of mutations with highly conserved domains in galactose-1-phosphate uridyl transferase. | galactosemia is an autosomal recessive disorder of human galactose metabolism caused by deficiency of the enzyme galactose-1-phosphate uridyl transferase (galt). the molecular basis of this disorder is at present not well understood. we report here two missense mutations which result in low or undetectable enzymatic activity. first, we identified at nucleotide 591 a transition which substitutes glutamine 188 by arginine. the mutated glutamine is not only highly conserved in evolution (conserved ... | 1991 | 1897530 |
| [coliform bacilli which produce cytotoxins: importance in veterinary medicine and public health]. | this article reviews published data (october 1st, 1990) on 4 types of cytotoxins produced by animal and human pathogenic strains of e coli, ie, verotoxins, also named shiga-like toxins, cytotoxic necrotizing factors, haemolysin, and cytolethal distending toxin. the biological and molecular properties are described for each type of cytotoxin, the association of producing strains with animal pathology, and the role of domestic animals as reservoirs of strains pathogenic for man. | 1991 | 1897865 |
| preparation and crystallization of human transthyretin (prealbumin) variants. | naturally occurring variants of human serum transthyretin (prealbumin) have been prepared by recombinant dna methods and crystallized from ammonium sulfate solutions to give crystals suitable for x-ray crystallographic analysis. included are variants which are known to be associated with familial amyloidotic polyneuropathy. dyes which have been used as histochemical stains to identify amyloid tissue deposits: congo red, methylene blue and bromophenol blue, have been co-crystallized with the tran ... | 1991 | 1898403 |
| characterization of recombinant human kirsten-ras (4b) p21 produced at high levels in escherichia coli and insect baculovirus expression systems. | kirsten-ras is the oncogene most frequently activated in human tumors. studies of its biological function have been limited by the nonavailability of significant amounts of the major protein product, kirsten-ras (4b) p21. when expressed in escherichia coli k12, the recombinant protein was rapidly cleaved upon cell lysis in the lysine-rich c terminus region, probably by the ompt protease. however, soluble full-length protein was obtained when the kirsten-ras gene was expressed in an e. coli strai ... | 1991 | 1899093 |
| mouse hepatocytes migrate to liver parenchyma and function indefinitely after intrasplenic transplantation. | one approach to gene therapy for hepatic diseases is to remove hepatocytes from an affected individual, genetically alter them in vitro, and reimplant them into a receptive locus. although returning hepatocytes to the liver itself would be advantageous, the feasibility of this approach has never been evaluated due to the inability to distinguish donor from host hepatocytes. to unambiguously identify transplanted hepatocytes after transplantation, and to better quantitate their number and degree ... | 1991 | 1899924 |
| the product of the rap2 gene, member of the ras superfamily. biochemical characterization and site-directed mutagenesis. | the human rap2 gene encodes a 183 amino acid protein that shares 46% identity with the k-ras p21. its cdna was engineered and inserted into the bacterial expression vector ptac; this allowed the production of high levels of soluble recombinant protein in escherichia coli that was purified to near homogeneity. the rap2 protein binds gtp and exhibits a low intrinsic gtpase activity (rate constant of 0.5 x 10(-2) min-1). it exchanges its bound gdp with a half-life of 18 min at 37 degrees c in the p ... | 1991 | 1900290 |
| autonomous dna replication in human cells is affected by the size and the source of the dna. | we previously developed short-term and long-term assays for autonomous replication of dna in human cells. this study addresses the requirements for replication in these assays. sixty-two random human genomic fragments ranging in size from 1 to 21 kb were cloned in a prokaryotic vector and tested for their replication ability in the short-term assay. we found a positive correlation between replication strength and fragment length, indicating that large size is favored for efficient autonomous rep ... | 1991 | 1900922 |
| analyzing the substrate specificity of saccharomyces cerevisiae myristoyl-coa:protein n-myristoyltransferase by co-expressing it with mammalian g protein alpha subunits in escherichia coli. | a dual plasmid system was used to examine the protein and acyl-coa specificities of saccharomyces cerevisiae myristoyl-coa:protein n-myristoyltransferase (nmt) by co-expressing it in escherichia coli with each of four homologous alpha subunits of the signal-transducing, heterotrimeric g proteins. exogenous [3h]myristate was incorporated into rat gi alpha 1 and rat go alpha but not into bovine gs alpha or human gz alpha. oxygen for methylene group substitutions in myristate result in analogs with ... | 1991 | 1903791 |
| in vitro binding of human t-cell leukemia virus rex proteins to the rex-response element of viral transcripts. | human t-cell leukemia virus (htlv-i, htlv-ii) rex protein function is required for the cytoplasmic expression of incompletely spliced viral transcripts encoding structural proteins. the effect is mediated by a cis-acting rex-response element (rrx) which is located near the 3' end of all viral mrnas. we show that rex polypeptides of htlv-i and htlv-ii expressed in escherichia coli are capable of specifically binding rrx-containing transcripts of both viruses in cell-free assays. binding analyses ... | 1991 | 1904103 |
| the type i human t-cell leukemia virus (htlv-i) rex trans-activator binds directly to the htlv-i rex and the type 1 human immunodeficiency virus rev rna response elements. | the rex protein of the type i human t-cell leukemia virus (htlv-i) is essential for the replication of this pathogenic retrovirus and, surprisingly, can also replace the function of the structurally distinct rev protein of the type 1 human immunodeficiency virus (hiv-1). rex action requires a 255-nucleotide viral rna stem-loop structure termed the rex rna response element (rexre) located in the 3' retroviral long terminal repeat. rex function leads to the induced cytoplasmic expression of the in ... | 1991 | 1905815 |
| amino acid sequence of the fv region of a human monoclonal igm (nov) with specificity for the capsular polysaccharide of the group b meningococcus and of escherichia coli k1, which cross-reacts with polynucleotides and with denatured dna. | the complete amino acid sequences of the vh and vl regions of a biologically significant ig, igmnov, were determined. igmnov is reactive with the capsular polysaccharide of the group b meningococcus and of escherichia coli k1. as reported earlier, it cross-reacts completely with polynucleotides poly(a) and poly(i) and to a lesser extent with denatured dna and protects newborn rats against infection with e. coli k1, and is equal in potency to the standard horse anti-group b meningococcal serum. t ... | 1991 | 1907308 |
| molecular cloning of human beta 1,4-galactosyltransferase and expression of catalytic activity of the fusion protein in escherichia coli. | 1. three groups of cdna clones (total of six) for human udp-galactose: beta n-acetylglucosamine galactosyltransferase (4 beta gt) were obtained by screening of a fetal liver library in lambda gt11 with an affinity purified anti4 beta gt antibody. 2. one group of clones (three clones) reacted with two distinct anti4 beta gt murine monoclonal antibodies. 3. nucleotide sequence of this group of clones were similar to published sequence for human 4 beta gtcdna, except the 74 nucleotides at the 5'-en ... | 1991 | 1907577 |
| structure of the beta-glucosidase gene bgla of clostridium thermocellum. sequence analysis reveals a superfamily of cellulases and beta-glycosidases including human lactase/phlorizin hydrolase. | the nucleotide sequence of the clostridium thermocellum gene bgla, coding for the thermostable beta-glucosidase a, has been determined. the coding region of 1344 bp was identified by comparison with the n-terminal amino acid squence of recombinant beta-glucosidase a purified from escherichia coli. the deduced amino acid sequence corresponds to a protein of 51,482 da. the coding region is flanked by putative promoter and transcription terminator sequences. the protein is unrelated to beta-glucosi ... | 1991 | 1909624 |
| synovial fluid-derived yersinia-reactive t cells responding to human 65-kda heat-shock protein and heat-stressed antigen-presenting cells. | humoral and cellular immune reactions to heat-shock proteins have been implicated in the pathogenesis of arthritis. heat-shock proteins occur in bacteria as well as all eukaryotes and have been highly conserved during evolution. cross-reactivity between bacterial and human heat-shock proteins induced at the site of inflammation may underlie the pathogenesis of some forms of arthritis. in order to test this hypothesis, we raised and cloned a yersinia-specific t cell line from the synovial fluid l ... | 1991 | 1909642 |
| rsr1 and rap1 gtpases are activated by the same gtpase-activating protein and require threonine 65 for their activation. | the rsr1 protein of saccharomyces cerevisiae has been shown to be essential for bud site selection (bender, a., and pringle, j. (1989) proc. natl. acad. sci. u.s.a. 86, 9976-9980). this protein of 272 amino acids shares approximately 50% sequence identity with both ras and rap gtpases. however, neither gtp binding nor gtpase activity of the rsr1 protein has been reported. the rsr1 protein shares with human rap1 gtpases the four specific motifs, i.e. gly-12, residues 32-40, ala-59, and residues 6 ... | 1991 | 1910037 |
| dose-ranging study of the novel recombinant plasminogen activator bm 06.022 in healthy volunteers. | the novel recombinant plasminogen activator bm 06.022 consists of the kringle 2 and protease domains of human tissue-type plasminogen activator and is unglycosylated because of its expression in escherichia coli cells. pharmacokinetics for activity and hemostatic effects of bm 06.022 were studied in 18 healthy male volunteers after an intravenous bolus injection over 2 minutes. bm 06.022 was administered successively at doses of 0.1125, 0.55, 2.2, 3.3, 4.4, and 5.5 mu to three volunteers. plasma ... | 1991 | 1914379 |
| in vitro phagocytic interaction between trichomonas vaginalis isolates and bacteria. | the phagocytic activity of 12 trichomonas vaginalis isolates against both gram-positive bacteria (staphylococcus aureus atcc 25923, lactobacillus spp.) and gram-negative bacteria (enterobacter cloacae atcc 13047, 5 strains of escherichia coli, pseudomonas aeruginosa atcc 27853) was studied. results showed that all the isolates were able to ingest staphylococcus aureus to a variable degree, and almost all of them showed phagocytic activity against pseudomonas aeruginosa. furthermore, experiments ... | 1991 | 1915384 |
| site-specific mutations in human ferredoxin that affect binding to ferredoxin reductase and cytochrome p450scc. | ferredoxins found in animal mitochondria function in electron transfer from nadph-dependent ferredoxin reductase (fd-reductase) to cytochrome p450 enzymes. to identify residues involved in binding of human ferredoxin to its electron transfer partners, neutral amino acids were introduced in a highly conserved acidic region (positions 68-86) by site-directed mutagenesis of the cdna. mutant ferredoxins were produced in escherichia coli, and separate assays were used to determine the effect of subst ... | 1991 | 1917982 |
| structure and expression during development of drosophila melanogaster gene for dna polymerase alpha. | the drosophila melanogaster gene and cdna which span the entire open reading frame for dna polymerase alpha, were cloned, and their nucleotide sequences were determined. the gene consists of 6 exons separated by 5 short introns. the major transcription initiation site was localized 85 bp upstream from the initiation codon. the nucleotide sequence of the open reading frame revealed a polypeptide of 1,505 amino acid residues with a molecular weight of 170,796. the amino acid sequence of the polype ... | 1991 | 1923767 |
| identification and expression of the cdna of kin17, a zinc-finger gene located on mouse chromosome 2, encoding a new dna-binding protein. | we report the cloning of kin17 cdna, 1414 bp long with an orf of 391 residues showing a zinc finger and nuclear localization signals. by recloning the cdna into an appropriate vector, we produced kin17 protein in e. coli, purified it partially and shown that kin17 protein binds to double-stranded dna. the kin17 gene was localized by cytogenetic mapping in mouse chromosome 2, band a. genomic sequences homologous to kin17 cdna were detected also in rat and human dnas. kin17 mrna is highly expresse ... | 1991 | 1923796 |
| mechanism of synergistic transcriptional transactivation by the human glucocorticoid receptor. | induction of transcription from a promoter with two upstream glucocorticoid response elements is 10- to 20-fold greater than that from a similar promoter with only one response element. we have shown that interactions involving the major transactivation domain of the glucocorticoid receptor (tau 1) are the sole determinant of such synergistic transactivation by the receptor. the other transactivation domain of the receptor (tau 2) did not mediate synergistic transactivation, and therefore the ab ... | 1991 | 1924286 |
| a soluble, single-chain t-cell receptor fragment endowed with antigen-combining properties. | a strategy for the production of small, soluble, single-chain t-cell receptor (sctcr) fragments that carry an intact tcr antigen-combining site is presented. the rationale is based on structural similarity between tcr and antibody molecules and use of computer modeling methods to derive a model structure of a human sctcr variable (v)-domain dimer. a gene encoding the rfl3.8 tcr protein, specific for the hapten fluorescein in the context of major histocompatibility complex class ii and composed o ... | 1991 | 1924326 |
| engineering the substrate specificity of glutathione reductase toward that of trypanothione reduction. | glutathione reductase (ec 1.6.4.2; cas registry number 9001-48-3) and trypanothione reductase (cas registry number 102210-35-5), which are related flavoprotein disulfide oxidoreductases, have marked specificities for glutathione and trypanothione, respectively. a combination of primary sequence alignments and molecular modeling, together with the high-resolution crystal structure of human glutathione reductase, identified certain residues as potentially being responsible for substrate discrimina ... | 1991 | 1924337 |
| the human homologous pairing protein hpp-1 is specifically stimulated by the cognate single-stranded binding protein hrp-a. | homologous pairing and strand exchange of dna are catalyzed by the human homologous pairing protein hpp-1 in a magnesium-dependent, atp-independent reaction that requires homologous dna substrates and stoichiometric quantities of hpp-1. here we show that the addition of the purified human single-strand binding (ssb) protein hrp-a to the reaction mixture stimulates the rate of homologous pairing 70-fold and reduces the amount of hpp-1 required for the reaction at least 10-fold. the identification ... | 1991 | 1924369 |
| cloning and characterization of a 3-methyladenine dna glycosylase cdna from human cells whose gene maps to chromosome 16. | we described previously the isolation of a saccharomyces cerevisiae 3-methyladenine (3-meade) dna glycosylase repair gene (mag) by its expression in glycosylase-deficient escherichia coli alka tag mutant cells and its ability to rescue these cells from the toxic effects of alkylating agents. here we extend this cross-species functional complementation approach to the isolation of a full-length human 3-meade dna glycosylase cdna that rescues alka tag e. coli from killing by methyl methanesulfonat ... | 1991 | 1924375 |
| [a case of emphysematous cystitis with familial amyloidosis]. | this is a report of the thirteenth known case in japan of emphysematous cystitis. a 70-year-old man visited our hospital because of pollakisuria and macrohematuria on november 21, 1989. the patient had been known to have familiar amyloid polyneuropathy for the previous 3 years. urinalysis showed marked hematopyuria. the residual urine was 216 cc, and urine cultures yielded 10,000,000 colonies of escherichia coli per ml. laboratory studies revealed systemic inflammatory findings, but no diabetic ... | 1991 | 1927781 |
| mechanisms of interaction among subinhibitory concentrations of antibiotics, human polymorphonuclear neutrophils, and gram-negative bacilli. | our hypothesis was that pretreatment of bacteria with subinhibitory concentrations (sub-mics) of antibiotics enhances the susceptibility of the organisms to killing by human polymorphonuclear neutrophils (pmns). our purpose was to study a variety of drugs with different mechanisms of action and to determine whether the mechanism and locus of action altered the sub-mic effect. the following outcome measures were used: ingestion and killing of bacteria by pmns, bacterial killing in the absence of ... | 1991 | 1929284 |
| trans-dominant tat mutants with alterations in the basic domain inhibit hiv-1 gene expression. | the tat protein of the human immunodeficiency virus type 1 (hiv-1) is required for efficient viral gene expression. by means of mutational analyses, several domains of the tat protein that are required for complete activation of hiv-1 gene expression have been defined. these include an amino-terminal activating domain, a cysteine-rich dimerization domain, and a basic domain important in the binding of tat to the trans-activation response element (tar) and in tat nuclear localization. recently, w ... | 1991 | 1931822 |
| expression and mutagenesis of human poly(adp-ribose) polymerase as a ubiquitin fusion protein from escherichia coli. | the cdna of human poly(adp-ribose) polymerase (padprp), encoding the entire protein, was subcloned into the escherichia coli expression plasmid pyub. in this expression system, the carboxyl terminus of ubiquitin is fused to the amino terminus of a target protein, in this case padprp, stabilizing the accumulation of the cloned gene product. following induction of the transformed cells, the sonicated extract contained a unique protein immunoreactive with both padprp and ubiquitin antibodies and co ... | 1991 | 1931966 |
| the mammalian tfiid protein is present in two functionally distinct complexes. | the tfiid activity recognizes a tata-box element and supports formation of an initiation complex containing rna polymerase ii. antisera specific for the 38-kd human tfiid protein were used to determine whether this protein cofractionated with the tfiid activity. surprisingly, the tfiid activity in hela whole-cell extracts was resolved into two different size complexes, one of 300 kd and one of greater than 700 kd. cofractionation studies suggest that both complexes contain the 38-kd protein; thu ... | 1991 | 1936986 |
| low-usage codons in escherichia coli, yeast, fruit fly and primates. | codon usage is compared between four classes of species, with an emphasis on characterization of low-usage codons. the classes of species analyzed include the bacterium escherichia coli (eco), the yeast saccharomyces cerevisiae (ysc), the fruit fly drosophila melanogaster (dro), and several species of primates (pri) (taken as a group; includes eleven species for which nucleotide sequence data have been reported to genbank, however, greater than 90% of the sequences were from homo sapiens). the n ... | 1991 | 1937008 |
| recombinant escherichia coli clones expressing chlamydia trachomatis gene products attach to human endometrial epithelial cells. | to identify chlamydia trachomatis genes involved in attachment to host cells, a chlamydial genomic library was screened on the basis of binding characteristics by two methods. in the whole-cell screen, individual recombinant escherichia coli clones were assayed for adherence to eukaryotic cells. in the membrane-binding screen, each recombinant colony of e. coli was treated with chcl3 and assayed for binding to purified, 3-[(3-cholamidopropyl)-dimethyl-ammonio]-1-propanesulfonate (chaps)-solubili ... | 1991 | 1937759 |
| extracellular release of reactive oxygen species from human neutrophils upon interaction with escherichia coli strains causing renal scarring. | the production of reactive oxygen metabolites by neutrophils plays a key role in the host defense against invading microorganisms and in tissue damage resulting from infection. in the present study we measured the ability of different uropathogenic escherichia coli strains to induce generation of oxygen metabolites upon interaction with human neutrophils. the strains were selected to represent two groups of patients with recurrent episodes of acute pyelonephritis: one with renal scars (12 strain ... | 1991 | 1937773 |
| shiga toxin-associated hemolytic-uremic syndrome: combined cytotoxic effects of shiga toxin, interleukin-1 beta, and tumor necrosis factor alpha on human vascular endothelial cells in vitro. | this study explores the relationship between shiga toxin-producing shigella or escherichia coli strains and the development of vascular complications in humans following bacillary dysentery. we propose that endotoxin-elicited interleukin-1 or tumor necrosis factor alpha (tnf) may combine with shiga toxin to facilitate vascular damage characteristic of hemolytic-uremic syndrome. this study examines the cytotoxic effects of shiga toxin, interleukin-1, and tnf on cultured human umbilical vein endot ... | 1991 | 1937774 |
| copper-zinc superoxide dismutase of haemophilus influenzae and h. parainfluenzae. | copper-zinc superoxide dismutase ([cu,zn]-sod) is widely found in eukaryotes but has only rarely been identified in bacteria. here we describe sodc, encoding [cu,zn]-sod in haemophilus influenzae and h. parainfluenzae, frequent colonists and pathogens of the human respiratory tract. in capsulate h. influenzae, sodc was found in only one division of the bacterial population, and although the protein it encoded was clearly [cu,zn]-sod from its deduced sequence, it lacked enzymatic activity. in h. ... | 1991 | 1938942 |
| expression of a synthetic gene for human cap binding protein (human if-4e) in escherichia coli and fluorescence studies on interaction with mrna cap structure analogues. | an artificial gene coding for the human cap binding protein (hcbp: human if-4e) was chemically synthesized and expressed in escherichia coli under the control of a trp promoter. the dna duplex of 662 bp was designed and constructed from 44 oligodeoxynucleotide fragments of typically 30 nucleotides in length. although the hcbp gene was not directly expressed in e. coli hb101, we succeeded in its high-level expression as a fusion protein connected with a portion of human growth hormone through a t ... | 1991 | 1939010 |
| human t cell responses to gp63, a surface antigen of leishmania. | gp63, an abundant and conserved leishmania cell surface protein, has been implicated in the ability of these parasitic protozoa to infect macrophages in vitro and has shown potential as a protective immunogen in mice. however, little is known regarding human immune responses to this glycoprotein ag. in this study, human t lymphocyte responses to leishmania amazonensis native gp63 and to recombinant gp63 (rgp63) produced in escherichia coli were evaluated in individuals with active or cured cutan ... | 1991 | 1940356 |
| gene expression of the a- and b-chain of mouse c1q in different tissues and the characterization of the recombinant a-chain. | immunoscreening of a mouse macrophage cdna library with an anti-mouse c1q-antibody resulted in the isolation of cdna clones. the deduced amino acid sequence was homologous to the a-chain of human c1q. homology on the dna level was found to be 76% and on the protein level 72% thus it appeared the clones coded for the mouse c1q a-chain. an immunoblot of murine serum c1q separated by sds-page was detected with an a-chain specific antibody that had been affinity purified on recombinant mouse c1q a-c ... | 1991 | 1940381 |
| the localization of indium-111-leukocytes, gallium-67-polyclonal igg and other radioactive agents in acute focal inflammatory lesions. | a variety of radioactive agents, injected directly intravenously have demonstrated foci of inflammation by gamma camera imaging, avoiding the in vitro preparation of labeled leukocytes. this study sought to find out if any of these agents mimicked the biodistribution in abscesses and non-target organs of labeled mixed leukocyte suspensions. eight different agents were compared with 111in-oxine labeled leukocytes in an acute soft tissue e. coli abscess and an acute arthritic lesion in 24 dogs one ... | 1991 | 1941149 |
| early hemodynamic indicators of gram-negative sepsis and shock in an infant pig model. | to assess the hemodynamics of early shock and to determine to what extent hemodynamic indicators of sepsis and shock can be predictive, we evaluated data from several series of experiments (including 136 piglets) in which animals were subjected to fecal-escherichia coli peritonitis-induced septic shock. serial measurements of 39 parameters were obtained and their values taken at baseline, at hyperdynamic sepsis, and at shock were compared by analysis of variance. piglet weights ranged from 1.2 t ... | 1991 | 1941483 |
| maple syrup urine disease: domain structure, mutations and exon skipping in the dihydrolipoyl transacylase (e2) component of the branched-chain alpha-keto acid dehydrogenase complex. | maple syrup urine disease (msud) is an autosomal recessive disorder in the oxidative decarboxylation of the branched-chain alpha-keto acids derived from leucine, isoleucine and valine. the enzyme deficient in msud, the branched-chain alpha-keto acid dehydrogenase (bckad) complex, is a mitochondrial multienzyme complex consisting of at least six distinct subunits. msud is genetically heterogeneous as manifested by lesions in different subunits of the bckad complex among unrelated patients. to app ... | 1991 | 1943690 |
| integration of pharmacokinetics and pharmacodynamics of imipenem in a human-adapted mouse model. | the relationship between the pharmacokinetics and bactericidal activity of imipenem against pseudomonas aeruginosa and escherichia coli was investigated in a neutropenic mouse thigh infection model. to circumvent the problem of short elimination time in small animals, imipenem was administered in fractionized, decreasing doses such that the pharmacokinetic profiles as observed in humans after intravenous and intramuscular injections were approximated in mice. the human-simulated kinetic profile ... | 1991 | 1952865 |
| cloning and sequence analysis of the human liver rhodanese: comparison with the bovine and chicken enzymes. | the cdna for the human rhodanese (thiosulfate: cyanide sulfurtransferase, ec 2.8.1.1), a nuclearly encoded protein of the mitochondrial matrix, was isolated from a human fetal liver cdna library. nucleotide sequence revealed an open reading frame coding for a polypeptide of 295 amino acids, which presented a 57% and 58% identity with the bovine and avian rhodanese, respectively. the analysis of the 5'-ends of the coding region gave no evidence for the presence of a cleavable signal sequence as f ... | 1991 | 1953758 |
| effects of zinc and other divalent metals on deoxyribonucleic acid binding and hormone-binding activity of human alpha 1 thyroid hormone receptor expressed in escherichia coli. | full-length human thyroid hormone receptor alpha 1 (htr alpha 1) was expressed in escherichia coli using a t7 expression system. while present in large amounts, the receptor was highly enriched in the insoluble fraction after cell lysis. we describe here the successful solubilization and refolding of the expressed receptor in a functional form in the presence of zn2+. using a dna-cellulose binding assay and gel shift assay, we found that treatment of expressed receptor with 1 mm edta in the dena ... | 1991 | 1954886 |
| purification of a 20 kda phosphoprotein from epithelial cells and identification as a myosin light chain. phosphorylation induced by enteropathogenic escherichia coli and phorbol ester. | previous studies on the mechanism of enteropathogenic escherichia coli (epec) infection have revealed an increase in the phosphorylation state of a number of proteins in human laryngeal hep-2 cells. the most prominent was an acidic phosphoprotein(s) of mr 20-21 kda. the present study reports: (a) a simple method for purification of phosphorylated 20 kda protein; (b) identification of the 20 kda phosphoprotein as myosin light chain; and (c) that the phorbol ester, tpa, also increased the phosphor ... | 1991 | 1959591 |
| antibiotic susceptibility, hemolysin production and haemagglutinating activity of uropathogenic escherichia coli. | the hemolysin production, haemagglutinating activity (ha) with human 0 group erythrocytes and antibiotic susceptibility of 130 uropathogenic escherichia coli strains were studied. 43% of the strains produced hemolysins and 39% showed haemagglutinating activity. in 12% of the haemagglutinating strains ha was inhibited by d-mannose. 45% of the hemolytic strains showed haemagglutinating activity. there was a significant relationship between hemolysin production and haemagglutination activity (p les ... | 1991 | 1960393 |
| ionizing radiation at low doses induces inflammatory reactions in human blood. | irradiation of whole blood with 137cs gamma rays intensifies the oxidative burst. oxidant production was used as an indicator of inflammatory cell reactions and was measured by luminol-amplified chemiluminescence after treatment with inflammatory activators including bacteria, the neutrophil taxin formyl-met-leu-phe, the ca2+ ionophore a23187, the detergent saponin, and the tumor promoter phorbol ester. the irradiation response is dose-dependent up to about 100 microgy, is detectable within minu ... | 1991 | 1961921 |
| systemic delivery of human growth hormone by injection of genetically engineered myoblasts. | a recombinant gene encoding human growth hormone (hgh) was stably introduced into cultured myoblasts with a retroviral vector. after injection of genetically engineered myoblasts into mouse muscle, hgh could be detected in serum for 3 months. the fate of injected myoblasts was assessed by coinfecting the cells with two retroviral vectors, one encoding hgh and the other encoding beta-galactosidase from escherichia coli. these results provide evidence that myoblasts, which can fuse into preexistin ... | 1991 | 1962213 |
| topological effects of ebna 1 on orip. | | 1990 | 1963028 |
| the effect of endotoxin lipopolysaccharide from different bacterial species on the generation of intracellular inositol trisphosphate and superoxide in a human phagocytic cell line. | the acute effects of endotoxins and lipid a on two intracellular responses, inositol phosphate generation and superoxide production were analysed in the dmso differentiated premyelocytic leukaemic hl-60 cell line. short-term incubation (1-10 min) with escherichia coli-type lps, salmonella-type lps and lipid a caused significant increases in cellular insp1 and insp3, compared with control cells (p less than 0.5-p less than 0.001). the escherichia coli-type lps released approximately twice the qua ... | 1990 | 1963542 |
| generation of a 50,000-member human dna library with an average dna insert size of 75-100 kbp in a bacteriophage p1 cloning vector. | a bacteriophage p1 cloning system that permits the isolation and amplification of cloned dna fragments as large as 100 kbp was described previously. we have now utilized a similar system to generate a 50,000-member human dna library with dna inserts ranging in size from 75 to 100 kbp. two major obstacles were overcome in constructing the library. the first concerned the mcrab restriction system of escherichia coli, which degrades dna containing mec and interferes with the recovery of cloned huma ... | 1990 | 1964591 |
| characterization of a new putative colonization factor (cs17) from a human enterotoxigenic escherichia coli of serotype o114:h21 which produces only heat-labile enterotoxin. | enterotoxigenic escherichia coli (etec) of serotype o114:h21, which produced only heat-labile enterotoxin (lt), gave mannose-resistant hemagglutination (mrha) with bovine erythrocytes. one strain, e20738a, was shown to possess fimbriae of approximately 7.5 nm diameter. on sds-page two possible fimbrial polypeptides of molecular masses 17.5 and 15.5 kda were seen; the 17.5-kda band was the most prominent. loss of lt and mrha together from strain e20738a was associated with loss of a 100-mda plasm ... | 1990 | 1967623 |
| development of antibodies to unprotected glycosylation sites on recombinant human gm-csf. | in 4 out of 16 patients receiving recombinant human granulocyte macrophage colony stimulating factor (rhgm-csf) in phase i/ii studies antibodies developed to the recombinant protein. the antibodies react with sites on the native protein backbone which are normally protected by o-linked glycosylation but which are exposed in rhgm-csf produced in yeast and escherichia coli. antigenicity of recombinant human proteins due to non glycosylation may have relevance to the choice of host system for produ ... | 1990 | 1968169 |
| cloning and nucleotide sequence of cdna for ki antigen, a highly conserved nuclear protein detected with sera from patients with systemic lupus erythematosus. | patients with systemic lupus erythematosus (sle) produce autoantibodies against a variety of nuclear antigens including ki antigen. although anti-ki autoantibodies were found in a significant number of sle patients, the nature of ki antigen is poorly characterized. by using anti-ki serum as a probe we have cloned a bovine cdna directing the synthesis in escherichia coli of a polypeptide immunologically indistinguishable from the authentic ki antigen. a homologous human cdna was also cloned and i ... | 1990 | 1968796 |
| identification of plasmid-encoded mannose-resistant hemagglutinin and hep-2 and hela cell adherence factors of two diarrheagenic escherichia coli strains belonging to an enteropathogenic serogroup. | two escherichia coli strains (b/m 369 and c-35) belonging to enteropathogenic serogroup o86 were isolated from patients with infantile diarrhea and studied with respect to their cellular adherence properties. both strains exhibited adherence (ad+) to hep-2 and hela cell monolayers in vitro and expressed mannose-resistant hemagglutinating (mrha+) activity towards human, chicken, and sheep (but not mouse, rabbit, or guinea pig) erythrocytes. cellular adherence properties of both strains could be s ... | 1990 | 1969390 |
| cloning and expression in escherichia coli of lkp pilus genes from a nontypeable haemophilus influenzae strain. | nontypeable haemophilus influenzae hf0295, isolated by aspiration from the middle ear of a patient with otitis media, expresses long, thick, and hemagglutinating pili of a single serotype (lkp1) on its surface. an intact pilus vaccine consisting of the lkp1 serotype protected chinchillas against experimental otitis media (c. c. brinton, jr., m. j. carter, d. b. derber, s. kar, j. a. kramarik, a. c. c. to, s. c. m. to, and s. w. wood, pediatr. infect. dis. j. 8:554-561, 1989; r. b. karasic, d. j. ... | 1990 | 1969397 |
| molecular cloning, structure and expression of the yeast proliferating cell nuclear antigen gene. | the budding yeast saccharomyces cerevisiae is proving to be an useful and accurate model for eukaryotic dna replication. it contains both dna polymerase alpha (i) and delta (iii). recently, proliferating cell nuclear antigen (pcna), which in mammalian cells is an auxiliary subunit of dna polymerase delta and is essential for in vitro leading strand sv40 dna replication, was purified from yeast. we have now cloned the gene for yeast pcna (pol30). the gene codes for an essential protein of 29 kda, ... | 1990 | 1970160 |
| homologous sugar transport proteins in escherichia coli and their relatives in both prokaryotes and eukaryotes. | separate proteins for proton-linked transport of d-xylose, l-arabinose, d-galactose, l-rhamnose and l-fucose into escherichia coli are being studied. by cloning and sequencing the appropriate genes, the amino acid sequences of proteins for d-xylose/h+ symport (xyle), l-arabinose/h+ symport (arae), and part of the protein for d-galactose/h+ symport (galp) have been determined. these are homologous, with at least 28% identical amino acid residues conserved in the aligned sequences, although their ... | 1990 | 1970645 |
| signal transduction in human platelets and inflammatory mediator release induced by genetically cloned hemolysin-positive and -negative escherichia coli strains. | incubation of human platelets with the hemolysin-producing escherichia coli strain k-12 (pann5211) induced the activation of protein kinase c, aggregation of platelets, calcium influx, low amounts of 12-hydroxyeicosatetraenoic acid (12-hete), and release of serotonin from dense granules. nonhemolytic isogenic strains of e. coli 536/21 which differed only in their types of adhesins (msh+ ms-fim+; s-mrh+ s-fim+; p-mrh+ p-fim+) released neither serotonin nor 12-hete from human platelets nor induced ... | 1990 | 1971256 |
| the influence of net surface charge on the interaction of uropathogenic escherichia coli with human neutrophils. | escherichia coli strains, grown to suppress fimbrial expression, synthesised enhanced quantities of polysaccharide capsule, which significantly lessened their binding to heparin sepharose columns. in the presence of poly-l-lysine, these strains were strongly retained on the columns confirming their highly anionic nature. uropathogenic strains of e. coli expressing type 1 fimbrial adhesins activated the respiratory burst, the degranulation response and the release of leukotrienes from human neutr ... | 1990 | 1973056 |